1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN 24 * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #define BTSTACK_FILE__ "l2cap.c" 39 40 /* 41 * l2cap.c 42 * Logical Link Control and Adaption Protocol (L2CAP) 43 */ 44 45 #include "l2cap.h" 46 #include "hci.h" 47 #include "hci_dump.h" 48 #include "bluetooth_sdp.h" 49 #include "bluetooth_psm.h" 50 #include "btstack_bool.h" 51 #include "btstack_debug.h" 52 #include "btstack_event.h" 53 #include "btstack_memory.h" 54 55 #ifdef ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE 56 // TODO avoid dependency on higher layer: used to trigger pairing for outgoing connections 57 #include "ble/sm.h" 58 #endif 59 60 #include <stdarg.h> 61 #include <string.h> 62 63 /* 64 * @brief L2CAP Supervisory function in S-Frames 65 */ 66 typedef enum { 67 L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY = 0, 68 L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT, 69 L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY, 70 L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT 71 } l2cap_supervisory_function_t; 72 73 /** 74 * @brief L2CAP Information Types used in Information Request & Response 75 */ 76 typedef enum { 77 L2CAP_INFO_TYPE_CONNECTIONLESS_MTU = 1, 78 L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED, 79 L2CAP_INFO_TYPE_FIXED_CHANNELS_SUPPORTED, 80 } l2cap_info_type_t; 81 82 /** 83 * @brief L2CAP Configuration Option Types used in Configurateion Request & Response 84 */ 85 typedef enum { 86 L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT = 1, 87 L2CAP_CONFIG_OPTION_TYPE_FLUSH_TIMEOUT, 88 L2CAP_CONFIG_OPTION_TYPE_QUALITY_OF_SERVICE, 89 L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL, 90 L2CAP_CONFIG_OPTION_TYPE_FRAME_CHECK_SEQUENCE, 91 L2CAP_CONFIG_OPTION_TYPE_EXTENDED_FLOW_SPECIFICATION, 92 L2CAP_CONFIG_OPTION_TYPE_EXTENDED_WINDOW_SIZE, 93 } l2cap_config_option_type_t; 94 95 96 #define L2CAP_SIG_ID_INVALID 0 97 98 // size of HCI ACL + L2CAP Header for regular data packets (8) 99 #define COMPLETE_L2CAP_HEADER (HCI_ACL_HEADER_SIZE + L2CAP_HEADER_SIZE) 100 101 // L2CAP Configuration Result Codes 102 #define L2CAP_CONF_RESULT_SUCCESS 0x0000 103 #define L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS 0x0001 104 #define L2CAP_CONF_RESULT_REJECT 0x0002 105 #define L2CAP_CONF_RESULT_UNKNOWN_OPTIONS 0x0003 106 #define L2CAP_CONF_RESULT_PENDING 0x0004 107 #define L2CAP_CONF_RESULT_FLOW_SPEC_REJECTED 0x0005 108 109 // L2CAP Reject Result Codes 110 #define L2CAP_REJ_CMD_UNKNOWN 0x0000 111 112 // Response Timeout eXpired 113 #define L2CAP_RTX_TIMEOUT_MS 10000 114 115 // Extended Response Timeout eXpired 116 #define L2CAP_ERTX_TIMEOUT_MS 120000 117 118 // nr of buffered acl packets in outgoing queue to get max performance 119 #define NR_BUFFERED_ACL_PACKETS 3 120 121 // used to cache l2cap rejects, echo, and informational requests 122 #define NR_PENDING_SIGNALING_RESPONSES 3 123 124 // nr of credits provided to remote if credits fall below watermark 125 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK 5 126 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT 5 127 128 // offsets for L2CAP SIGNALING COMMANDS 129 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 130 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 131 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 132 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 133 134 #ifdef ENABLE_LE_DATA_CHANNELS 135 #warning "ENABLE_LE_DATA_CHANNELS has been deprecated." 136 #warning "Please use ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE instead in btstack_config.h" 137 #define ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE 138 #endif 139 140 #if defined(ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE) || defined(ENABLE_L2CAP_ENHANCED_DATA_CHANNELS) 141 #define ENABLE_L2CAP_CREDIT_BASED_CHANNELS 142 #endif 143 144 #if defined(ENABLE_L2CAP_CREDIT_BASED_CHANNELS) || defined(ENABLE_CLASSIC) 145 #define L2CAP_USES_CHANNELS 146 #endif 147 148 // prototypes 149 static void l2cap_run(void); 150 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 151 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ); 152 static void l2cap_notify_channel_can_send(void); 153 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel); 154 static uint8_t l2cap_next_sig_id(void); 155 static l2cap_fixed_channel_t * l2cap_fixed_channel_for_channel_id(uint16_t local_cid); 156 #ifdef ENABLE_CLASSIC 157 static void l2cap_handle_security_level_incoming_sufficient(l2cap_channel_t * channel); 158 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm); 159 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel); 160 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel); 161 static void l2cap_handle_information_request_complete(hci_connection_t * connection); 162 static inline l2cap_service_t * l2cap_get_service(uint16_t psm); 163 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 164 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 165 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel); 166 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 167 #endif 168 #ifdef ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE 169 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status); 170 static void l2cap_emit_le_channel_closed(l2cap_channel_t * channel); 171 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel); 172 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel); 173 static void l2cap_le_finialize_channel_close(l2cap_channel_t *channel); 174 static inline l2cap_service_t * l2cap_le_get_service(uint16_t psm); 175 #endif 176 #ifdef ENABLE_L2CAP_CREDIT_BASED_CHANNELS 177 static void l2cap_credit_based_send_pdu(l2cap_channel_t *channel); 178 static void l2cap_credit_based_send_credits(l2cap_channel_t *channel); 179 static bool l2cap_credit_based_handle_credit_indication(hci_con_handle_t handle, const uint8_t * command, uint16_t len); 180 static void l2cap_credit_based_handle_pdu(l2cap_channel_t * l2cap_channel, const uint8_t * packet, uint16_t size); 181 #endif 182 #ifdef L2CAP_USES_CHANNELS 183 static uint16_t l2cap_next_local_cid(void); 184 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid); 185 static void l2cap_emit_simple_event_with_cid(l2cap_channel_t * channel, uint8_t event_code); 186 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size); 187 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, l2cap_channel_type_t channel_type, bd_addr_t address, bd_addr_type_t address_type, 188 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level); 189 static void l2cap_finalize_channel_close(l2cap_channel_t *channel); 190 static void l2cap_free_channel_entry(l2cap_channel_t * channel); 191 #endif 192 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 193 static void l2cap_ertm_notify_channel_can_send(l2cap_channel_t * channel); 194 static void l2cap_ertm_monitor_timeout_callback(btstack_timer_source_t * ts); 195 static void l2cap_ertm_retransmission_timeout_callback(btstack_timer_source_t * ts); 196 #endif 197 #ifdef ENABLE_L2CAP_ENHANCED_DATA_CHANNELS 198 static int l2cap_enhanced_signaling_handler_dispatch(hci_con_handle_t handle, uint16_t signaling_cid, uint8_t * command, uint8_t sig_id); 199 #endif 200 201 // l2cap_fixed_channel_t entries 202 #ifdef ENABLE_BLE 203 static l2cap_fixed_channel_t l2cap_fixed_channel_att; 204 static l2cap_fixed_channel_t l2cap_fixed_channel_sm; 205 #endif 206 #ifdef ENABLE_CLASSIC 207 static l2cap_fixed_channel_t l2cap_fixed_channel_connectionless; 208 #endif 209 210 #ifdef ENABLE_CLASSIC 211 static btstack_linked_list_t l2cap_services; 212 static uint8_t l2cap_require_security_level2_for_outgoing_sdp; 213 static bd_addr_t l2cap_outgoing_classic_addr; 214 #endif 215 216 #ifdef ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE 217 static btstack_linked_list_t l2cap_le_services; 218 #endif 219 220 #ifdef ENABLE_L2CAP_ENHANCED_DATA_CHANNELS 221 static btstack_linked_list_t l2cap_enhanced_services; 222 static uint16_t l2cap_enhanced_mps_min; 223 static uint16_t l2cap_enhanced_mps_max; 224 #endif 225 226 // single list of channels for Classic Channels, LE Data Channels, Classic Connectionless, ATT, and SM 227 static btstack_linked_list_t l2cap_channels; 228 #ifdef L2CAP_USES_CHANNELS 229 // next channel id for new connections 230 static uint16_t l2cap_local_source_cid; 231 #endif 232 // next signaling sequence number 233 static uint8_t l2cap_sig_seq_nr; 234 235 // used to cache l2cap rejects, echo, and informational requests 236 static l2cap_signaling_response_t l2cap_signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 237 static int l2cap_signaling_responses_pending; 238 static btstack_packet_callback_registration_t l2cap_hci_event_callback_registration; 239 240 static bool l2cap_call_notify_channel_in_run; 241 242 #ifdef ENABLE_BLE 243 // only used for connection parameter update events 244 static uint16_t l2cap_le_custom_max_mtu; 245 #endif 246 247 /* callbacks for events */ 248 static btstack_linked_list_t l2cap_event_handlers; 249 250 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 251 252 // enable for testing 253 // #define L2CAP_ERTM_SIMULATE_FCS_ERROR_INTERVAL 16 254 255 /* 256 * CRC lookup table for generator polynom D^16 + D^15 + D^2 + 1 257 */ 258 static const uint16_t crc16_table[256] = { 259 0x0000, 0xc0c1, 0xc181, 0x0140, 0xc301, 0x03c0, 0x0280, 0xc241, 0xc601, 0x06c0, 0x0780, 0xc741, 0x0500, 0xc5c1, 0xc481, 0x0440, 260 0xcc01, 0x0cc0, 0x0d80, 0xcd41, 0x0f00, 0xcfc1, 0xce81, 0x0e40, 0x0a00, 0xcac1, 0xcb81, 0x0b40, 0xc901, 0x09c0, 0x0880, 0xc841, 261 0xd801, 0x18c0, 0x1980, 0xd941, 0x1b00, 0xdbc1, 0xda81, 0x1a40, 0x1e00, 0xdec1, 0xdf81, 0x1f40, 0xdd01, 0x1dc0, 0x1c80, 0xdc41, 262 0x1400, 0xd4c1, 0xd581, 0x1540, 0xd701, 0x17c0, 0x1680, 0xd641, 0xd201, 0x12c0, 0x1380, 0xd341, 0x1100, 0xd1c1, 0xd081, 0x1040, 263 0xf001, 0x30c0, 0x3180, 0xf141, 0x3300, 0xf3c1, 0xf281, 0x3240, 0x3600, 0xf6c1, 0xf781, 0x3740, 0xf501, 0x35c0, 0x3480, 0xf441, 264 0x3c00, 0xfcc1, 0xfd81, 0x3d40, 0xff01, 0x3fc0, 0x3e80, 0xfe41, 0xfa01, 0x3ac0, 0x3b80, 0xfb41, 0x3900, 0xf9c1, 0xf881, 0x3840, 265 0x2800, 0xe8c1, 0xe981, 0x2940, 0xeb01, 0x2bc0, 0x2a80, 0xea41, 0xee01, 0x2ec0, 0x2f80, 0xef41, 0x2d00, 0xedc1, 0xec81, 0x2c40, 266 0xe401, 0x24c0, 0x2580, 0xe541, 0x2700, 0xe7c1, 0xe681, 0x2640, 0x2200, 0xe2c1, 0xe381, 0x2340, 0xe101, 0x21c0, 0x2080, 0xe041, 267 0xa001, 0x60c0, 0x6180, 0xa141, 0x6300, 0xa3c1, 0xa281, 0x6240, 0x6600, 0xa6c1, 0xa781, 0x6740, 0xa501, 0x65c0, 0x6480, 0xa441, 268 0x6c00, 0xacc1, 0xad81, 0x6d40, 0xaf01, 0x6fc0, 0x6e80, 0xae41, 0xaa01, 0x6ac0, 0x6b80, 0xab41, 0x6900, 0xa9c1, 0xa881, 0x6840, 269 0x7800, 0xb8c1, 0xb981, 0x7940, 0xbb01, 0x7bc0, 0x7a80, 0xba41, 0xbe01, 0x7ec0, 0x7f80, 0xbf41, 0x7d00, 0xbdc1, 0xbc81, 0x7c40, 270 0xb401, 0x74c0, 0x7580, 0xb541, 0x7700, 0xb7c1, 0xb681, 0x7640, 0x7200, 0xb2c1, 0xb381, 0x7340, 0xb101, 0x71c0, 0x7080, 0xb041, 271 0x5000, 0x90c1, 0x9181, 0x5140, 0x9301, 0x53c0, 0x5280, 0x9241, 0x9601, 0x56c0, 0x5780, 0x9741, 0x5500, 0x95c1, 0x9481, 0x5440, 272 0x9c01, 0x5cc0, 0x5d80, 0x9d41, 0x5f00, 0x9fc1, 0x9e81, 0x5e40, 0x5a00, 0x9ac1, 0x9b81, 0x5b40, 0x9901, 0x59c0, 0x5880, 0x9841, 273 0x8801, 0x48c0, 0x4980, 0x8941, 0x4b00, 0x8bc1, 0x8a81, 0x4a40, 0x4e00, 0x8ec1, 0x8f81, 0x4f40, 0x8d01, 0x4dc0, 0x4c80, 0x8c41, 274 0x4400, 0x84c1, 0x8581, 0x4540, 0x8701, 0x47c0, 0x4680, 0x8641, 0x8201, 0x42c0, 0x4380, 0x8341, 0x4100, 0x81c1, 0x8081, 0x4040, 275 }; 276 277 static uint16_t crc16_calc(uint8_t * data, uint16_t len){ 278 uint16_t crc = 0; // initial value = 0 279 while (len--){ 280 crc = (crc >> 8) ^ crc16_table[ (crc ^ ((uint16_t) *data++)) & 0x00FF ]; 281 } 282 return crc; 283 } 284 285 static inline uint16_t l2cap_encanced_control_field_for_information_frame(uint8_t tx_seq, int final, uint8_t req_seq, l2cap_segmentation_and_reassembly_t sar){ 286 return (((uint16_t) sar) << 14) | (req_seq << 8) | (final << 7) | (tx_seq << 1) | 0; 287 } 288 289 static inline uint16_t l2cap_encanced_control_field_for_supevisor_frame(l2cap_supervisory_function_t supervisory_function, int poll, int final, uint8_t req_seq){ 290 return (req_seq << 8) | (final << 7) | (poll << 4) | (((int) supervisory_function) << 2) | 1; 291 } 292 293 static int l2cap_next_ertm_seq_nr(int seq_nr){ 294 return (seq_nr + 1) & 0x3f; 295 } 296 297 static bool l2cap_ertm_can_store_packet_now(l2cap_channel_t * channel){ 298 // get num free tx buffers 299 int num_free_tx_buffers = channel->num_tx_buffers - channel->num_stored_tx_frames; 300 // calculate num tx buffers for remote MTU 301 int num_tx_buffers_for_max_remote_mtu; 302 uint16_t effective_mps = btstack_min(channel->remote_mps, channel->local_mps); 303 if (channel->remote_mtu <= effective_mps){ 304 // MTU fits into single packet 305 num_tx_buffers_for_max_remote_mtu = 1; 306 } else { 307 // include SDU Length 308 num_tx_buffers_for_max_remote_mtu = (channel->remote_mtu + 2 + (effective_mps - 1)) / effective_mps; 309 } 310 log_debug("num_free_tx_buffers %u, num_tx_buffers_for_max_remote_mtu %u", num_free_tx_buffers, num_tx_buffers_for_max_remote_mtu); 311 return num_tx_buffers_for_max_remote_mtu <= num_free_tx_buffers; 312 } 313 314 static void l2cap_ertm_retransmit_unacknowleded_frames(l2cap_channel_t * l2cap_channel){ 315 log_info("Retransmit unacknowleged frames"); 316 l2cap_channel->unacked_frames = 0;; 317 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 318 } 319 320 static void l2cap_ertm_next_tx_write_index(l2cap_channel_t * channel){ 321 channel->tx_write_index++; 322 if (channel->tx_write_index < channel->num_tx_buffers) return; 323 channel->tx_write_index = 0; 324 } 325 326 static void l2cap_ertm_start_monitor_timer(l2cap_channel_t * channel){ 327 log_info("Start Monitor timer"); 328 btstack_run_loop_remove_timer(&channel->monitor_timer); 329 btstack_run_loop_set_timer_handler(&channel->monitor_timer, &l2cap_ertm_monitor_timeout_callback); 330 btstack_run_loop_set_timer_context(&channel->monitor_timer, channel); 331 btstack_run_loop_set_timer(&channel->monitor_timer, channel->local_monitor_timeout_ms); 332 btstack_run_loop_add_timer(&channel->monitor_timer); 333 } 334 335 static void l2cap_ertm_stop_monitor_timer(l2cap_channel_t * channel){ 336 log_info("Stop Monitor timer"); 337 btstack_run_loop_remove_timer(&channel->monitor_timer); 338 } 339 340 static void l2cap_ertm_start_retransmission_timer(l2cap_channel_t * channel){ 341 log_info("Start Retransmission timer"); 342 btstack_run_loop_remove_timer(&channel->retransmission_timer); 343 btstack_run_loop_set_timer_handler(&channel->retransmission_timer, &l2cap_ertm_retransmission_timeout_callback); 344 btstack_run_loop_set_timer_context(&channel->retransmission_timer, channel); 345 btstack_run_loop_set_timer(&channel->retransmission_timer, channel->local_retransmission_timeout_ms); 346 btstack_run_loop_add_timer(&channel->retransmission_timer); 347 } 348 349 static void l2cap_ertm_stop_retransmission_timer(l2cap_channel_t * l2cap_channel){ 350 log_info("Stop Retransmission timer"); 351 btstack_run_loop_remove_timer(&l2cap_channel->retransmission_timer); 352 } 353 354 static void l2cap_ertm_monitor_timeout_callback(btstack_timer_source_t * ts){ 355 log_info("Monitor timeout"); 356 l2cap_channel_t * l2cap_channel = (l2cap_channel_t *) btstack_run_loop_get_timer_context(ts); 357 358 // TODO: we assume that it's the oldest packet 359 l2cap_ertm_tx_packet_state_t * tx_state; 360 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 361 362 // check retry count 363 if (tx_state->retry_count < l2cap_channel->remote_max_transmit){ 364 // increment retry count 365 tx_state->retry_count++; 366 367 // start retransmit 368 l2cap_ertm_retransmit_unacknowleded_frames(l2cap_channel); 369 370 // start monitor timer 371 l2cap_ertm_start_monitor_timer(l2cap_channel); 372 373 // send RR/P=1 374 l2cap_channel->send_supervisor_frame_receiver_ready_poll = 1; 375 } else { 376 log_info("Monitor timer expired & retry count >= max transmit -> disconnect"); 377 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 378 } 379 l2cap_run(); 380 } 381 382 static void l2cap_ertm_retransmission_timeout_callback(btstack_timer_source_t * ts){ 383 log_info("Retransmission timeout"); 384 l2cap_channel_t * l2cap_channel = (l2cap_channel_t *) btstack_run_loop_get_timer_context(ts); 385 386 // TODO: we assume that it's the oldest packet 387 l2cap_ertm_tx_packet_state_t * tx_state; 388 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 389 390 // set retry count = 1 391 tx_state->retry_count = 1; 392 393 // start retransmit 394 l2cap_ertm_retransmit_unacknowleded_frames(l2cap_channel); 395 396 // start monitor timer 397 l2cap_ertm_start_monitor_timer(l2cap_channel); 398 399 // send RR/P=1 400 l2cap_channel->send_supervisor_frame_receiver_ready_poll = 1; 401 l2cap_run(); 402 } 403 404 static int l2cap_ertm_send_information_frame(l2cap_channel_t * channel, int index, int final){ 405 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[index]; 406 hci_reserve_packet_buffer(); 407 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 408 uint16_t control = l2cap_encanced_control_field_for_information_frame(tx_state->tx_seq, final, channel->req_seq, tx_state->sar); 409 log_info("I-Frame: control 0x%04x", control); 410 little_endian_store_16(acl_buffer, 8, control); 411 (void)memcpy(&acl_buffer[8 + 2], 412 &channel->tx_packets_data[index * channel->local_mps], 413 tx_state->len); 414 // (re-)start retransmission timer on 415 l2cap_ertm_start_retransmission_timer(channel); 416 // send 417 return l2cap_send_prepared(channel->local_cid, 2 + tx_state->len); 418 } 419 420 static void l2cap_ertm_store_fragment(l2cap_channel_t * channel, l2cap_segmentation_and_reassembly_t sar, uint16_t sdu_length, uint8_t * data, uint16_t len){ 421 // get next index for storing packets 422 int index = channel->tx_write_index; 423 424 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[index]; 425 tx_state->tx_seq = channel->next_tx_seq; 426 tx_state->sar = sar; 427 tx_state->retry_count = 0; 428 429 uint8_t * tx_packet = &channel->tx_packets_data[index * channel->local_mps]; 430 log_debug("index %u, local mps %u, remote mps %u, packet tx %p, len %u", index, channel->local_mps, channel->remote_mps, tx_packet, len); 431 int pos = 0; 432 if (sar == L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU){ 433 little_endian_store_16(tx_packet, 0, sdu_length); 434 pos += 2; 435 } 436 (void)memcpy(&tx_packet[pos], data, len); 437 tx_state->len = pos + len; 438 439 // update 440 channel->num_stored_tx_frames++; 441 channel->next_tx_seq = l2cap_next_ertm_seq_nr(channel->next_tx_seq); 442 l2cap_ertm_next_tx_write_index(channel); 443 444 log_info("l2cap_ertm_store_fragment: tx_read_index %u, tx_write_index %u, num stored %u", channel->tx_read_index, channel->tx_write_index, channel->num_stored_tx_frames); 445 446 } 447 448 static uint8_t l2cap_ertm_send(l2cap_channel_t * channel, uint8_t * data, uint16_t len){ 449 if (len > channel->remote_mtu){ 450 log_error("l2cap_ertm_send cid 0x%02x, data length exceeds remote MTU.", channel->local_cid); 451 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 452 } 453 454 if (!l2cap_ertm_can_store_packet_now(channel)){ 455 log_error("l2cap_ertm_send cid 0x%02x, fragment store full", channel->local_cid); 456 return BTSTACK_ACL_BUFFERS_FULL; 457 } 458 459 // check if it needs to get fragmented 460 uint16_t effective_mps = btstack_min(channel->remote_mps, channel->local_mps); 461 if (len > effective_mps){ 462 // fragmentation needed. 463 l2cap_segmentation_and_reassembly_t sar = L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU; 464 int chunk_len; 465 while (len){ 466 switch (sar){ 467 case L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU: 468 chunk_len = effective_mps - 2; // sdu_length 469 l2cap_ertm_store_fragment(channel, sar, len, data, chunk_len); 470 len -= chunk_len; 471 sar = L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU; 472 break; 473 case L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU: 474 chunk_len = effective_mps; 475 if (chunk_len >= len){ 476 sar = L2CAP_SEGMENTATION_AND_REASSEMBLY_END_OF_L2CAP_SDU; 477 chunk_len = len; 478 } 479 l2cap_ertm_store_fragment(channel, sar, len, data, chunk_len); 480 len -= chunk_len; 481 break; 482 default: 483 break; 484 } 485 } 486 487 } else { 488 l2cap_ertm_store_fragment(channel, L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU, 0, data, len); 489 } 490 491 // try to send 492 l2cap_notify_channel_can_send(); 493 return ERROR_CODE_SUCCESS; 494 } 495 496 static uint16_t l2cap_setup_options_ertm_request(l2cap_channel_t * channel, uint8_t * config_options){ 497 int pos = 0; 498 config_options[pos++] = L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL; 499 config_options[pos++] = 9; // length 500 config_options[pos++] = (uint8_t) channel->mode; 501 config_options[pos++] = channel->num_rx_buffers; // == TxWindows size 502 config_options[pos++] = channel->local_max_transmit; 503 little_endian_store_16( config_options, pos, channel->local_retransmission_timeout_ms); 504 pos += 2; 505 little_endian_store_16( config_options, pos, channel->local_monitor_timeout_ms); 506 pos += 2; 507 little_endian_store_16( config_options, pos, channel->local_mps); 508 pos += 2; 509 // 510 config_options[pos++] = L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT; 511 config_options[pos++] = 2; // length 512 little_endian_store_16(config_options, pos, channel->local_mtu); 513 pos += 2; 514 515 // Issue: iOS (e.g. 10.2) uses "No FCS" as default while Core 5.0 specifies "FCS" as default 516 // Workaround: try to actively negotiate FCS option 517 config_options[pos++] = L2CAP_CONFIG_OPTION_TYPE_FRAME_CHECK_SEQUENCE; 518 config_options[pos++] = 1; // length 519 config_options[pos++] = channel->fcs_option; 520 return pos; // 11+4+3=18 521 } 522 523 static uint16_t l2cap_setup_options_ertm_response(l2cap_channel_t * channel, uint8_t * config_options){ 524 int pos = 0; 525 config_options[pos++] = L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL; 526 config_options[pos++] = 9; // length 527 config_options[pos++] = (uint8_t) channel->mode; 528 // less or equal to remote tx window size 529 config_options[pos++] = btstack_min(channel->num_tx_buffers, channel->remote_tx_window_size); 530 // max transmit in response shall be ignored -> use sender values 531 config_options[pos++] = channel->remote_max_transmit; 532 // A value for the Retransmission time-out shall be sent in a positive Configuration Response 533 // and indicates the value that will be used by the sender of the Configuration Response -> use our value 534 little_endian_store_16( config_options, pos, channel->local_retransmission_timeout_ms); 535 pos += 2; 536 // A value for the Monitor time-out shall be sent in a positive Configuration Response 537 // and indicates the value that will be used by the sender of the Configuration Response -> use our value 538 little_endian_store_16( config_options, pos, channel->local_monitor_timeout_ms); 539 pos += 2; 540 // less or equal to remote mps 541 uint16_t effective_mps = btstack_min(channel->remote_mps, channel->local_mps); 542 little_endian_store_16( config_options, pos, effective_mps); 543 pos += 2; 544 // 545 config_options[pos++] = L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT; // MTU 546 config_options[pos++] = 2; // length 547 little_endian_store_16(config_options, pos, channel->remote_mtu); 548 pos += 2; 549 #if 0 550 // 551 config_options[pos++] = L2CAP_CONFIG_OPTION_TYPE_FRAME_CHECK_SEQUENCE; 552 config_options[pos++] = 1; // length 553 config_options[pos++] = channel->fcs_option; 554 #endif 555 return pos; // 11+4=15 556 } 557 558 static int l2cap_ertm_send_supervisor_frame(l2cap_channel_t * channel, uint16_t control){ 559 hci_reserve_packet_buffer(); 560 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 561 log_info("S-Frame: control 0x%04x", control); 562 little_endian_store_16(acl_buffer, 8, control); 563 return l2cap_send_prepared(channel->local_cid, 2); 564 } 565 566 static uint8_t l2cap_ertm_validate_local_config(l2cap_ertm_config_t * ertm_config){ 567 568 uint8_t result = ERROR_CODE_SUCCESS; 569 if (ertm_config->max_transmit < 1){ 570 log_error("max_transmit must be >= 1"); 571 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 572 } 573 if (ertm_config->retransmission_timeout_ms < 2000){ 574 log_error("retransmission_timeout_ms must be >= 2000 ms"); 575 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 576 } 577 if (ertm_config->monitor_timeout_ms < 12000){ 578 log_error("monitor_timeout_ms must be >= 12000 ms"); 579 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 580 } 581 if (ertm_config->local_mtu < 48){ 582 log_error("local_mtu must be >= 48"); 583 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 584 } 585 if (ertm_config->num_rx_buffers < 1){ 586 log_error("num_rx_buffers must be >= 1"); 587 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 588 } 589 if (ertm_config->num_tx_buffers < 1){ 590 log_error("num_rx_buffers must be >= 1"); 591 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 592 } 593 return result; 594 } 595 596 static void l2cap_ertm_configure_channel(l2cap_channel_t * channel, l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size){ 597 598 channel->mode = L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION; 599 channel->ertm_mandatory = ertm_config->ertm_mandatory; 600 channel->local_max_transmit = ertm_config->max_transmit; 601 channel->local_retransmission_timeout_ms = ertm_config->retransmission_timeout_ms; 602 channel->local_monitor_timeout_ms = ertm_config->monitor_timeout_ms; 603 channel->local_mtu = ertm_config->local_mtu; 604 channel->num_rx_buffers = ertm_config->num_rx_buffers; 605 channel->num_tx_buffers = ertm_config->num_tx_buffers; 606 607 // align buffer to 16-byte boundary to assert l2cap_ertm_rx_packet_state_t is aligned 608 int bytes_till_alignment = 16 - (((uintptr_t) buffer) & 0x0f); 609 buffer += bytes_till_alignment; 610 size -= bytes_till_alignment; 611 612 // setup state buffers - use void cast to avoid -Wcast-align warning 613 uint32_t pos = 0; 614 channel->rx_packets_state = (l2cap_ertm_rx_packet_state_t *) (void *) &buffer[pos]; 615 pos += ertm_config->num_rx_buffers * sizeof(l2cap_ertm_rx_packet_state_t); 616 channel->tx_packets_state = (l2cap_ertm_tx_packet_state_t *) (void *) &buffer[pos]; 617 pos += ertm_config->num_tx_buffers * sizeof(l2cap_ertm_tx_packet_state_t); 618 619 // setup reassembly buffer 620 channel->reassembly_buffer = &buffer[pos]; 621 pos += ertm_config->local_mtu; 622 623 // divide rest of data equally 624 channel->local_mps = (size - pos) / (ertm_config->num_rx_buffers + ertm_config->num_tx_buffers); 625 log_info("Local MPS: %u", channel->local_mps); 626 channel->rx_packets_data = &buffer[pos]; 627 pos += ertm_config->num_rx_buffers * channel->local_mps; 628 channel->tx_packets_data = &buffer[pos]; 629 630 channel->fcs_option = ertm_config->fcs_option; 631 } 632 633 uint8_t l2cap_create_ertm_channel(btstack_packet_handler_t packet_handler, bd_addr_t address, uint16_t psm, 634 l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size, uint16_t * out_local_cid){ 635 636 log_info("L2CAP_CREATE_ERTM_CHANNEL addr %s, psm 0x%x, local mtu %u", bd_addr_to_str(address), psm, ertm_config->local_mtu); 637 638 // validate local config 639 uint8_t result = l2cap_ertm_validate_local_config(ertm_config); 640 if (result) return result; 641 642 // determine security level based on psm 643 const gap_security_level_t security_level = l2cap_security_level_0_allowed_for_PSM(psm) ? LEVEL_0 : gap_get_security_level(); 644 645 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, L2CAP_CHANNEL_TYPE_CLASSIC, address, BD_ADDR_TYPE_ACL, psm, ertm_config->local_mtu, security_level); 646 if (!channel) { 647 return BTSTACK_MEMORY_ALLOC_FAILED; 648 } 649 650 // configure ERTM 651 l2cap_ertm_configure_channel(channel, ertm_config, buffer, size); 652 653 // add to connections list 654 btstack_linked_list_add_tail(&l2cap_channels, (btstack_linked_item_t *) channel); 655 656 // store local_cid 657 if (out_local_cid){ 658 *out_local_cid = channel->local_cid; 659 } 660 661 // check if hci connection is already usable 662 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_ACL); 663 if (conn){ 664 log_info("l2cap_create_channel, hci connection already exists"); 665 l2cap_handle_connection_complete(conn->con_handle, channel); 666 // check if remote supported fearures are already received 667 if (hci_remote_features_available(conn->con_handle)) { 668 l2cap_handle_remote_supported_features_received(channel); 669 } else { 670 hci_remote_features_query(conn->con_handle); 671 }; 672 } 673 674 l2cap_run(); 675 676 return 0; 677 } 678 679 static void l2cap_ertm_notify_channel_can_send(l2cap_channel_t * channel){ 680 if (l2cap_ertm_can_store_packet_now(channel)){ 681 channel->waiting_for_can_send_now = 0; 682 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 683 } 684 } 685 686 uint8_t l2cap_accept_ertm_connection(uint16_t local_cid, l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size){ 687 688 log_info("L2CAP_ACCEPT_ERTM_CONNECTION local_cid 0x%x", local_cid); 689 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 690 if (!channel) { 691 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 692 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 693 } 694 695 // validate local config 696 uint8_t result = l2cap_ertm_validate_local_config(ertm_config); 697 if (result) return result; 698 699 // configure L2CAP ERTM 700 l2cap_ertm_configure_channel(channel, ertm_config, buffer, size); 701 702 // already available? 703 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 704 btstack_assert(connection != NULL); 705 706 // we need to know if ERTM is supported before sending a config response 707 switch (connection->l2cap_state.information_state){ 708 case L2CAP_INFORMATION_STATE_DONE: 709 l2cap_handle_information_request_complete(connection); 710 break; 711 case L2CAP_INFORMATION_STATE_IDLE: 712 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 713 /* fall through */ 714 default: 715 channel->state = L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES; 716 break; 717 } 718 719 l2cap_run(); 720 721 return ERROR_CODE_SUCCESS; 722 } 723 724 uint8_t l2cap_ertm_set_busy(uint16_t local_cid){ 725 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 726 if (!channel) { 727 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 728 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 729 } 730 if (!channel->local_busy){ 731 channel->local_busy = 1; 732 channel->send_supervisor_frame_receiver_not_ready = 1; 733 l2cap_run(); 734 } 735 return ERROR_CODE_SUCCESS; 736 } 737 738 uint8_t l2cap_ertm_set_ready(uint16_t local_cid){ 739 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 740 if (!channel) { 741 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 742 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 743 } 744 if (channel->local_busy){ 745 channel->local_busy = 0; 746 channel->send_supervisor_frame_receiver_ready_poll = 1; 747 l2cap_run(); 748 } 749 return ERROR_CODE_SUCCESS; 750 } 751 752 // Process-ReqSeq 753 static void l2cap_ertm_process_req_seq(l2cap_channel_t * l2cap_channel, uint8_t req_seq){ 754 int num_buffers_acked = 0; 755 l2cap_ertm_tx_packet_state_t * tx_state; 756 log_info("l2cap_ertm_process_req_seq: tx_read_index %u, tx_write_index %u, req_seq %u", l2cap_channel->tx_read_index, l2cap_channel->tx_write_index, req_seq); 757 while (true){ 758 759 // no unack packets left 760 if (l2cap_channel->unacked_frames == 0) { 761 // stop retransmission timer 762 l2cap_ertm_stop_retransmission_timer(l2cap_channel); 763 break; 764 } 765 766 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 767 // calc delta 768 int delta = (req_seq - tx_state->tx_seq) & 0x03f; 769 if (delta == 0) break; // all packets acknowledged 770 if (delta > l2cap_channel->remote_tx_window_size) break; 771 772 num_buffers_acked++; 773 l2cap_channel->num_stored_tx_frames--; 774 l2cap_channel->unacked_frames--; 775 log_info("RR seq %u => packet with tx_seq %u done", req_seq, tx_state->tx_seq); 776 777 l2cap_channel->tx_read_index++; 778 if (l2cap_channel->tx_read_index >= l2cap_channel->num_rx_buffers){ 779 l2cap_channel->tx_read_index = 0; 780 } 781 } 782 if (num_buffers_acked){ 783 log_info("num_buffers_acked %u", num_buffers_acked); 784 l2cap_ertm_notify_channel_can_send(l2cap_channel); 785 } 786 } 787 788 static l2cap_ertm_tx_packet_state_t * l2cap_ertm_get_tx_state(l2cap_channel_t * l2cap_channel, uint8_t tx_seq){ 789 int i; 790 for (i=0;i<l2cap_channel->num_tx_buffers;i++){ 791 l2cap_ertm_tx_packet_state_t * tx_state = &l2cap_channel->tx_packets_state[i]; 792 if (tx_state->tx_seq == tx_seq) return tx_state; 793 } 794 return NULL; 795 } 796 797 // @param delta number of frames in the future, >= 1 798 // @assumption size <= l2cap_channel->local_mps (checked in l2cap_acl_classic_handler) 799 static void l2cap_ertm_handle_out_of_sequence_sdu(l2cap_channel_t * l2cap_channel, l2cap_segmentation_and_reassembly_t sar, int delta, const uint8_t * payload, uint16_t size){ 800 log_info("Store SDU with delta %u", delta); 801 // get rx state for packet to store 802 int index = l2cap_channel->rx_store_index + delta - 1; 803 if (index > l2cap_channel->num_rx_buffers){ 804 index -= l2cap_channel->num_rx_buffers; 805 } 806 log_info("Index of packet to store %u", index); 807 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 808 // check if buffer is free 809 if (rx_state->valid){ 810 log_error("Packet buffer already used"); 811 return; 812 } 813 rx_state->valid = 1; 814 rx_state->sar = sar; 815 rx_state->len = size; 816 uint8_t * rx_buffer = &l2cap_channel->rx_packets_data[index]; 817 (void)memcpy(rx_buffer, payload, size); 818 } 819 820 // @assumption size <= l2cap_channel->local_mps (checked in l2cap_acl_classic_handler) 821 static void l2cap_ertm_handle_in_sequence_sdu(l2cap_channel_t * l2cap_channel, l2cap_segmentation_and_reassembly_t sar, const uint8_t * payload, uint16_t size){ 822 uint16_t reassembly_sdu_length; 823 switch (sar){ 824 case L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU: 825 // assert total packet size <= our mtu 826 if (size > l2cap_channel->local_mtu) break; 827 // packet complete -> disapatch 828 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, (uint8_t*) payload, size); 829 break; 830 case L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU: 831 // read SDU len 832 reassembly_sdu_length = little_endian_read_16(payload, 0); 833 payload += 2; 834 size -= 2; 835 // assert reassembled size <= our mtu 836 if (reassembly_sdu_length > l2cap_channel->local_mtu) break; 837 // store start segment 838 l2cap_channel->reassembly_sdu_length = reassembly_sdu_length; 839 (void)memcpy(&l2cap_channel->reassembly_buffer[0], payload, size); 840 l2cap_channel->reassembly_pos = size; 841 break; 842 case L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU: 843 // assert size of reassembled data <= our mtu 844 if (l2cap_channel->reassembly_pos + size > l2cap_channel->local_mtu) break; 845 // store continuation segment 846 (void)memcpy(&l2cap_channel->reassembly_buffer[l2cap_channel->reassembly_pos], 847 payload, size); 848 l2cap_channel->reassembly_pos += size; 849 break; 850 case L2CAP_SEGMENTATION_AND_REASSEMBLY_END_OF_L2CAP_SDU: 851 // assert size of reassembled data <= our mtu 852 if (l2cap_channel->reassembly_pos + size > l2cap_channel->local_mtu) break; 853 // store continuation segment 854 (void)memcpy(&l2cap_channel->reassembly_buffer[l2cap_channel->reassembly_pos], 855 payload, size); 856 l2cap_channel->reassembly_pos += size; 857 // assert size of reassembled data matches announced sdu length 858 if (l2cap_channel->reassembly_pos != l2cap_channel->reassembly_sdu_length) break; 859 // packet complete -> disapatch 860 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->reassembly_buffer, l2cap_channel->reassembly_pos); 861 l2cap_channel->reassembly_pos = 0; 862 break; 863 default: 864 btstack_assert(false); 865 break; 866 } 867 } 868 869 static void l2cap_ertm_channel_send_information_frame(l2cap_channel_t * channel){ 870 channel->unacked_frames++; 871 int index = channel->tx_send_index; 872 channel->tx_send_index++; 873 if (channel->tx_send_index >= channel->num_tx_buffers){ 874 channel->tx_send_index = 0; 875 } 876 l2cap_ertm_send_information_frame(channel, index, 0); // final = 0 877 } 878 879 #endif 880 881 #ifdef L2CAP_USES_CHANNELS 882 static uint16_t l2cap_next_local_cid(void){ 883 do { 884 if (l2cap_local_source_cid == 0xfffeu) { 885 l2cap_local_source_cid = 0x40; 886 } else { 887 l2cap_local_source_cid++; 888 } 889 } while (l2cap_get_channel_for_local_cid(l2cap_local_source_cid) != NULL); 890 return l2cap_local_source_cid; 891 } 892 #endif 893 894 static uint8_t l2cap_next_sig_id(void){ 895 if (l2cap_sig_seq_nr == 0xffu) { 896 l2cap_sig_seq_nr = 1; 897 } else { 898 l2cap_sig_seq_nr++; 899 } 900 return l2cap_sig_seq_nr; 901 } 902 903 void l2cap_init(void){ 904 #ifdef L2CAP_USES_CHANNELS 905 l2cap_local_source_cid = 0x40; 906 #endif 907 l2cap_sig_seq_nr = 0xff; 908 909 #ifdef ENABLE_CLASSIC 910 // Setup Connectionless Channel 911 l2cap_fixed_channel_connectionless.local_cid = L2CAP_CID_CONNECTIONLESS_CHANNEL; 912 l2cap_fixed_channel_connectionless.channel_type = L2CAP_CHANNEL_TYPE_CONNECTIONLESS; 913 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) &l2cap_fixed_channel_connectionless); 914 #endif 915 916 #ifdef ENABLE_BLE 917 // Setup fixed ATT Channel 918 l2cap_fixed_channel_att.local_cid = L2CAP_CID_ATTRIBUTE_PROTOCOL; 919 l2cap_fixed_channel_att.channel_type = L2CAP_CHANNEL_TYPE_FIXED; 920 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) &l2cap_fixed_channel_att); 921 922 // Setup fixed SM Channel 923 l2cap_fixed_channel_sm.local_cid = L2CAP_CID_SECURITY_MANAGER_PROTOCOL; 924 l2cap_fixed_channel_sm.channel_type = L2CAP_CHANNEL_TYPE_FIXED; 925 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) &l2cap_fixed_channel_sm); 926 #endif 927 928 #ifdef ENABLE_L2CAP_ENHANCED_DATA_CHANNELS 929 l2cap_enhanced_mps_min = 0x0001; 930 l2cap_enhanced_mps_max = 0xffff; 931 #endif 932 933 // 934 // register callback with HCI 935 // 936 l2cap_hci_event_callback_registration.callback = &l2cap_hci_event_handler; 937 hci_add_event_handler(&l2cap_hci_event_callback_registration); 938 939 hci_register_acl_packet_handler(&l2cap_acl_handler); 940 941 #ifndef ENABLE_EXPLICIT_CONNECTABLE_MODE_CONTROL 942 #ifdef ENABLE_CLASSIC 943 gap_connectable_control(0); // no services yet 944 #endif 945 #endif 946 } 947 948 /** 949 * @brief De-Init L2CAP 950 */ 951 void l2cap_deinit(void){ 952 l2cap_channels = NULL; 953 l2cap_signaling_responses_pending = 0; 954 #ifdef ENABLE_CLASSIC 955 l2cap_require_security_level2_for_outgoing_sdp = 0; 956 (void)memset(&l2cap_fixed_channel_connectionless, 0, sizeof(l2cap_fixed_channel_connectionless)); 957 l2cap_services = NULL; 958 (void)memset(l2cap_outgoing_classic_addr, 0, 6); 959 #endif 960 #ifdef ENABLE_BLE 961 l2cap_le_custom_max_mtu = 0; 962 (void)memset(&l2cap_fixed_channel_att, 0, sizeof(l2cap_fixed_channel_att)); 963 (void)memset(&l2cap_fixed_channel_sm, 0, sizeof(l2cap_fixed_channel_sm)); 964 #endif 965 #ifdef ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE 966 l2cap_le_services = NULL; 967 #endif 968 #ifdef ENABLE_L2CAP_ENHANCED_DATA_CHANNELS 969 l2cap_enhanced_services = NULL; 970 #endif 971 l2cap_event_handlers = NULL; 972 } 973 974 void l2cap_add_event_handler(btstack_packet_callback_registration_t * callback_handler){ 975 btstack_linked_list_add_tail(&l2cap_event_handlers, (btstack_linked_item_t*) callback_handler); 976 } 977 978 void l2cap_remove_event_handler(btstack_packet_callback_registration_t * callback_handler){ 979 btstack_linked_list_remove(&l2cap_event_handlers, (btstack_linked_item_t*) callback_handler); 980 } 981 982 static void l2cap_emit_event(uint8_t *event, uint16_t size) { 983 hci_dump_packet( HCI_EVENT_PACKET, 0, event, size); 984 // dispatch to all event handlers 985 btstack_linked_list_iterator_t it; 986 btstack_linked_list_iterator_init(&it, &l2cap_event_handlers); 987 while (btstack_linked_list_iterator_has_next(&it)){ 988 btstack_packet_callback_registration_t * entry = (btstack_packet_callback_registration_t*) btstack_linked_list_iterator_next(&it); 989 entry->callback(HCI_EVENT_PACKET, 0, event, size); 990 } 991 } 992 993 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ 994 UNUSED(con_handle); // ok: there is no con handle 995 996 l2cap_fixed_channel_t * channel = l2cap_fixed_channel_for_channel_id(channel_id); 997 if (!channel) return; 998 channel->waiting_for_can_send_now = 1; 999 l2cap_notify_channel_can_send(); 1000 } 1001 1002 bool l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ 1003 UNUSED(channel_id); // ok: only depends on Controller LE buffers 1004 1005 return hci_can_send_acl_packet_now(con_handle); 1006 } 1007 1008 uint8_t *l2cap_get_outgoing_buffer(void){ 1009 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 1010 } 1011 1012 // only for L2CAP Basic Channels 1013 bool l2cap_reserve_packet_buffer(void){ 1014 return hci_reserve_packet_buffer(); 1015 } 1016 1017 // only for L2CAP Basic Channels 1018 void l2cap_release_packet_buffer(void){ 1019 hci_release_packet_buffer(); 1020 } 1021 1022 static void l2cap_setup_header(uint8_t * acl_buffer, hci_con_handle_t con_handle, uint8_t packet_boundary, uint16_t remote_cid, uint16_t len){ 1023 // 0 - Connection handle : PB=pb : BC=00 1024 little_endian_store_16(acl_buffer, 0u, con_handle | (packet_boundary << 12u) | (0u << 14u)); 1025 // 2 - ACL length 1026 little_endian_store_16(acl_buffer, 2u, len + 4u); 1027 // 4 - L2CAP packet length 1028 little_endian_store_16(acl_buffer, 4u, len + 0u); 1029 // 6 - L2CAP channel DEST 1030 little_endian_store_16(acl_buffer, 6, remote_cid); 1031 } 1032 1033 // assumption - only on LE connections 1034 uint8_t l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 1035 1036 if (!hci_is_packet_buffer_reserved()){ 1037 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 1038 return BTSTACK_ACL_BUFFERS_FULL; 1039 } 1040 1041 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 1042 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 1043 return BTSTACK_ACL_BUFFERS_FULL; 1044 } 1045 1046 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 1047 1048 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1049 l2cap_setup_header(acl_buffer, con_handle, 0, cid, len); 1050 // send 1051 return hci_send_acl_packet_buffer(len+8u); 1052 } 1053 1054 // assumption - only on LE connections 1055 uint8_t l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 1056 1057 if (!hci_can_send_acl_packet_now(con_handle)){ 1058 log_info("l2cap_send cid 0x%02x, cannot send", cid); 1059 return BTSTACK_ACL_BUFFERS_FULL; 1060 } 1061 1062 hci_reserve_packet_buffer(); 1063 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1064 1065 (void)memcpy(&acl_buffer[8], data, len); 1066 1067 return l2cap_send_prepared_connectionless(con_handle, cid, len); 1068 } 1069 1070 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { 1071 log_debug("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); 1072 uint8_t event[4]; 1073 event[0] = L2CAP_EVENT_CAN_SEND_NOW; 1074 event[1] = sizeof(event) - 2u; 1075 little_endian_store_16(event, 2, channel); 1076 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1077 packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); 1078 } 1079 1080 #ifdef L2CAP_USES_CHANNELS 1081 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 1082 (* (channel->packet_handler))(type, channel->local_cid, data, size); 1083 } 1084 1085 static void l2cap_emit_simple_event_with_cid(l2cap_channel_t * channel, uint8_t event_code){ 1086 uint8_t event[4]; 1087 event[0] = event_code; 1088 event[1] = sizeof(event) - 2u; 1089 little_endian_store_16(event, 2, channel->local_cid); 1090 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1091 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 1092 } 1093 #endif 1094 1095 #ifdef ENABLE_CLASSIC 1096 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 1097 log_info("L2CAP_EVENT_CHANNEL_OPENED status 0x%x addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x local_mtu %u, remote_mtu %u, flush_timeout %u", 1098 status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 1099 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 1100 uint8_t event[26]; 1101 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 1102 event[1] = sizeof(event) - 2; 1103 event[2] = status; 1104 reverse_bd_addr(channel->address, &event[3]); 1105 little_endian_store_16(event, 9, channel->con_handle); 1106 little_endian_store_16(event, 11, channel->psm); 1107 little_endian_store_16(event, 13, channel->local_cid); 1108 little_endian_store_16(event, 15, channel->remote_cid); 1109 little_endian_store_16(event, 17, channel->local_mtu); 1110 little_endian_store_16(event, 19, channel->remote_mtu); 1111 little_endian_store_16(event, 21, channel->flush_timeout); 1112 event[23] = (channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING) ? 1 : 0; 1113 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1114 log_info("ERTM mode %u, fcs enabled %u", channel->mode, channel->fcs_option); 1115 event[24] = channel->mode; 1116 event[25] = channel->fcs_option; 1117 1118 #else 1119 event[24] = L2CAP_CHANNEL_MODE_BASIC; 1120 event[25] = 0; 1121 #endif 1122 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1123 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 1124 } 1125 1126 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel) { 1127 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 1128 bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); 1129 uint8_t event[16]; 1130 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 1131 event[1] = sizeof(event) - 2; 1132 reverse_bd_addr(channel->address, &event[2]); 1133 little_endian_store_16(event, 8, channel->con_handle); 1134 little_endian_store_16(event, 10, channel->psm); 1135 little_endian_store_16(event, 12, channel->local_cid); 1136 little_endian_store_16(event, 14, channel->remote_cid); 1137 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1138 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 1139 } 1140 1141 static void l2cap_handle_channel_open_failed(l2cap_channel_t * channel, uint8_t status){ 1142 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1143 // emit ertm buffer released, as it's not needed. if in basic mode, it was either not allocated or already released 1144 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1145 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_ERTM_BUFFER_RELEASED); 1146 } 1147 #endif 1148 l2cap_emit_channel_opened(channel, status); 1149 } 1150 1151 #endif 1152 1153 #ifdef L2CAP_USES_CHANNELS 1154 1155 static void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 1156 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 1157 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 1158 } 1159 1160 static void l2cap_handle_channel_closed(l2cap_channel_t * channel){ 1161 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1162 // emit ertm buffer released, as it's not needed anymore. if in basic mode, it was either not allocated or already released 1163 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1164 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_ERTM_BUFFER_RELEASED); 1165 } 1166 #endif 1167 l2cap_emit_channel_closed(channel); 1168 } 1169 #endif 1170 1171 static l2cap_fixed_channel_t * l2cap_channel_item_by_cid(uint16_t cid){ 1172 btstack_linked_list_iterator_t it; 1173 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1174 while (btstack_linked_list_iterator_has_next(&it)){ 1175 l2cap_fixed_channel_t * channel = (l2cap_fixed_channel_t*) btstack_linked_list_iterator_next(&it); 1176 if (channel->local_cid == cid) { 1177 return channel; 1178 } 1179 } 1180 return NULL; 1181 } 1182 1183 // used for fixed channels in LE (ATT/SM) and Classic (Connectionless Channel). CID < 0x04 1184 static l2cap_fixed_channel_t * l2cap_fixed_channel_for_channel_id(uint16_t local_cid){ 1185 if (local_cid >= 0x40u) return NULL; 1186 return (l2cap_fixed_channel_t*) l2cap_channel_item_by_cid(local_cid); 1187 } 1188 1189 #ifdef L2CAP_USES_CHANNELS 1190 1191 static int l2cap_is_dynamic_channel_type(l2cap_channel_type_t channel_type) { 1192 switch (channel_type) { 1193 case L2CAP_CHANNEL_TYPE_CLASSIC: 1194 case L2CAP_CHANNEL_TYPE_LE_DATA_CHANNEL: 1195 case L2CAP_CHANNEL_TYPE_ENHANCED_DATA_CHANNEL: 1196 return 1; 1197 default: 1198 return 0; 1199 } 1200 } 1201 1202 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 1203 if (local_cid < 0x40u) return NULL; 1204 return (l2cap_channel_t*) l2cap_channel_item_by_cid(local_cid); 1205 } 1206 1207 static l2cap_channel_t * l2cap_get_channel_for_local_cid_and_handle(uint16_t local_cid, hci_con_handle_t con_handle){ 1208 if (local_cid < 0x40u) return NULL; 1209 l2cap_channel_t * l2cap_channel = (l2cap_channel_t*) l2cap_channel_item_by_cid(local_cid); 1210 if (l2cap_channel == NULL) return NULL; 1211 if (l2cap_channel->con_handle != con_handle) return NULL; 1212 return l2cap_channel; 1213 } 1214 #endif 1215 1216 #ifdef ENABLE_L2CAP_CREDIT_BASED_CHANNELS 1217 static l2cap_channel_t * l2cap_get_channel_for_remote_handle_and_cid(hci_con_handle_t con_handle, uint16_t remote_cid){ 1218 btstack_linked_list_iterator_t it; 1219 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1220 while (btstack_linked_list_iterator_has_next(&it)){ 1221 l2cap_fixed_channel_t * channel = (l2cap_fixed_channel_t*) btstack_linked_list_iterator_next(&it); 1222 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 1223 l2cap_channel_t * dynamic_channel = (l2cap_channel_t *) channel; 1224 if (dynamic_channel->con_handle != con_handle) continue; 1225 if (dynamic_channel->remote_cid != remote_cid) continue; 1226 return dynamic_channel; 1227 } 1228 return NULL; 1229 } 1230 #endif 1231 1232 #ifdef ENABLE_CLASSIC 1233 void l2cap_request_can_send_now_event(uint16_t local_cid){ 1234 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 1235 if (!channel) return; 1236 channel->waiting_for_can_send_now = 1; 1237 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1238 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1239 l2cap_ertm_notify_channel_can_send(channel); 1240 return; 1241 } 1242 #endif 1243 l2cap_notify_channel_can_send(); 1244 } 1245 1246 bool l2cap_can_send_packet_now(uint16_t local_cid){ 1247 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 1248 if (!channel) return false; 1249 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1250 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1251 return l2cap_ertm_can_store_packet_now(channel); 1252 } 1253 #endif 1254 return hci_can_send_acl_packet_now(channel->con_handle); 1255 } 1256 1257 bool l2cap_can_send_prepared_packet_now(uint16_t local_cid){ 1258 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 1259 if (!channel) return false; 1260 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1261 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1262 return false; 1263 } 1264 #endif 1265 return hci_can_send_prepared_acl_packet_now(channel->con_handle); 1266 } 1267 1268 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 1269 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1270 if (channel) { 1271 return channel->remote_mtu; 1272 } 1273 return 0; 1274 } 1275 #endif 1276 1277 #ifdef ENABLE_CLASSIC 1278 // RTX Timer only exist for dynamic channels 1279 static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ 1280 btstack_linked_list_iterator_t it; 1281 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1282 while (btstack_linked_list_iterator_has_next(&it)){ 1283 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1284 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 1285 if (&channel->rtx == ts) { 1286 return channel; 1287 } 1288 } 1289 return NULL; 1290 } 1291 1292 static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ 1293 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 1294 if (!channel) return; 1295 1296 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 1297 1298 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 1299 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 1300 // notify client 1301 l2cap_handle_channel_open_failed(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 1302 1303 // discard channel 1304 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1305 l2cap_free_channel_entry(channel); 1306 } 1307 1308 #endif 1309 1310 #ifdef L2CAP_USES_CHANNELS 1311 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 1312 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 1313 btstack_run_loop_remove_timer(&channel->rtx); 1314 } 1315 #endif 1316 1317 static uint8_t l2cap_send_signaling_packet(hci_con_handle_t handle, uint8_t pb_flags, uint16_t cid, L2CAP_SIGNALING_COMMANDS cmd, int identifier, va_list argptr){ 1318 if (!hci_can_send_acl_packet_now(handle)){ 1319 log_info("l2cap_send_classic_signaling_packet, cannot send"); 1320 return BTSTACK_ACL_BUFFERS_FULL; 1321 } 1322 hci_reserve_packet_buffer(); 1323 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1324 uint16_t len = l2cap_create_signaling_packet(acl_buffer, handle, pb_flags, cid, cmd, identifier, argptr); 1325 va_end(argptr); 1326 return hci_send_acl_packet_buffer(len); 1327 } 1328 1329 #ifdef ENABLE_L2CAP_CREDIT_BASED_CHANNELS 1330 static int l2cap_send_general_signaling_packet(hci_con_handle_t handle, uint16_t signaling_cid, L2CAP_SIGNALING_COMMANDS cmd, int identifier, ...){ 1331 va_list argptr; 1332 va_start(argptr, identifier); 1333 uint8_t pb_flags = 0x00; 1334 #ifdef ENABLE_CLASSIC 1335 if ((signaling_cid == L2CAP_CID_SIGNALING) && (!hci_non_flushable_packet_boundary_flag_supported())){ 1336 pb_flags = 0x02; 1337 } 1338 #endif 1339 uint8_t result = l2cap_send_signaling_packet(handle, pb_flags, signaling_cid, cmd, identifier, argptr); 1340 va_end(argptr); 1341 return result; 1342 } 1343 #endif 1344 1345 #ifdef ENABLE_CLASSIC 1346 1347 static void l2cap_start_rtx(l2cap_channel_t * channel){ 1348 l2cap_stop_rtx(channel); 1349 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 1350 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 1351 btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 1352 btstack_run_loop_add_timer(&channel->rtx); 1353 } 1354 1355 static void l2cap_start_ertx(l2cap_channel_t * channel){ 1356 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 1357 l2cap_stop_rtx(channel); 1358 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 1359 btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 1360 btstack_run_loop_add_timer(&channel->rtx); 1361 } 1362 1363 void l2cap_require_security_level_2_for_outgoing_sdp(void){ 1364 l2cap_require_security_level2_for_outgoing_sdp = 1; 1365 } 1366 1367 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 1368 return (psm == BLUETOOTH_PSM_SDP) && (!l2cap_require_security_level2_for_outgoing_sdp); 1369 } 1370 1371 static int l2cap_send_classic_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, int identifier, ...){ 1372 va_list argptr; 1373 va_start(argptr, identifier); 1374 uint8_t pb_flags = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 1375 uint8_t result = l2cap_send_signaling_packet(handle, pb_flags, L2CAP_CID_SIGNALING, cmd, identifier, argptr); 1376 va_end(argptr); 1377 return result; 1378 } 1379 1380 // assumption - only on Classic connections 1381 // cannot be used for L2CAP ERTM 1382 uint8_t l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 1383 1384 if (!hci_is_packet_buffer_reserved()){ 1385 log_error("l2cap_send_prepared called without reserving packet first"); 1386 return BTSTACK_ACL_BUFFERS_FULL; 1387 } 1388 1389 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1390 if (!channel) { 1391 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 1392 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1393 } 1394 1395 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 1396 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 1397 return BTSTACK_ACL_BUFFERS_FULL; 1398 } 1399 1400 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 1401 1402 int fcs_size = 0; 1403 1404 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1405 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION && channel->fcs_option){ 1406 fcs_size = 2; 1407 } 1408 #endif 1409 1410 // set non-flushable packet boundary flag if supported on Controller 1411 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1412 uint8_t packet_boundary_flag = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 1413 l2cap_setup_header(acl_buffer, channel->con_handle, packet_boundary_flag, channel->remote_cid, len + fcs_size); 1414 1415 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1416 if (fcs_size){ 1417 // calculate FCS over l2cap data 1418 uint16_t fcs = crc16_calc(acl_buffer + 4, 4 + len); 1419 log_info("I-Frame: fcs 0x%04x", fcs); 1420 little_endian_store_16(acl_buffer, 8 + len, fcs); 1421 } 1422 #endif 1423 1424 // send 1425 return hci_send_acl_packet_buffer(len+8+fcs_size); 1426 } 1427 1428 // assumption - only on Classic connections 1429 uint8_t l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 1430 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1431 if (!channel) { 1432 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 1433 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1434 } 1435 1436 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1437 // send in ERTM 1438 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1439 return l2cap_ertm_send(channel, data, len); 1440 } 1441 #endif 1442 1443 if (len > channel->remote_mtu){ 1444 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 1445 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 1446 } 1447 1448 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 1449 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 1450 return BTSTACK_ACL_BUFFERS_FULL; 1451 } 1452 1453 hci_reserve_packet_buffer(); 1454 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1455 (void)memcpy(&acl_buffer[8], data, len); 1456 return l2cap_send_prepared(local_cid, len); 1457 } 1458 1459 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ 1460 return l2cap_send_classic_signaling_packet(con_handle, ECHO_REQUEST, l2cap_next_sig_id(), len, data); 1461 } 1462 1463 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, uint16_t flag){ 1464 channel->state_var = channel->state_var | flag; 1465 } 1466 1467 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, uint16_t flag){ 1468 channel->state_var = channel->state_var & ~flag; 1469 } 1470 #endif 1471 1472 1473 #ifdef ENABLE_BLE 1474 static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, int identifier, ...){ 1475 va_list argptr; 1476 va_start(argptr, identifier); 1477 uint8_t pb_flags = 0x00; // First non-automatically-flushable packet of a higher layer message 1478 uint8_t result = l2cap_send_signaling_packet(handle, pb_flags, L2CAP_CID_SIGNALING_LE, cmd, identifier, argptr); 1479 va_end(argptr); 1480 return result; 1481 } 1482 #endif 1483 1484 uint16_t l2cap_max_mtu(void){ 1485 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 1486 } 1487 1488 #ifdef ENABLE_BLE 1489 uint16_t l2cap_max_le_mtu(void){ 1490 if (l2cap_le_custom_max_mtu != 0u) return l2cap_le_custom_max_mtu; 1491 return l2cap_max_mtu(); 1492 } 1493 1494 void l2cap_set_max_le_mtu(uint16_t max_mtu){ 1495 if (max_mtu < l2cap_max_mtu()){ 1496 l2cap_le_custom_max_mtu = max_mtu; 1497 } 1498 } 1499 #endif 1500 1501 #ifdef ENABLE_CLASSIC 1502 1503 static uint16_t l2cap_setup_options_mtu(uint8_t * config_options, uint16_t mtu){ 1504 config_options[0] = L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT; // MTU 1505 config_options[1] = 2; // len param 1506 little_endian_store_16(config_options, 2, mtu); 1507 return 4; 1508 } 1509 1510 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1511 static int l2cap_ertm_mode(l2cap_channel_t * channel){ 1512 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1513 return ((connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_DONE) 1514 && (connection->l2cap_state.extended_feature_mask & 0x08)); 1515 } 1516 #endif 1517 1518 static uint16_t l2cap_setup_options_request(l2cap_channel_t * channel, uint8_t * config_options){ 1519 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1520 // use ERTM options if supported by remote and channel ready to use it 1521 if (l2cap_ertm_mode(channel) && channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1522 return l2cap_setup_options_ertm_request(channel, config_options); 1523 } 1524 #endif 1525 uint16_t mtu = channel->local_mtu; 1526 return l2cap_setup_options_mtu(config_options, mtu); 1527 } 1528 1529 static uint16_t l2cap_setup_options_mtu_response(l2cap_channel_t * channel, uint8_t * config_options){ 1530 uint16_t mtu = btstack_min(channel->local_mtu, channel->remote_mtu); 1531 return l2cap_setup_options_mtu(config_options, mtu); 1532 } 1533 1534 static uint32_t l2cap_extended_features_mask(void){ 1535 // extended features request supported, features: fixed channels, unicast connectionless data reception 1536 uint32_t features = 0x280; 1537 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1538 features |= 0x0028; 1539 #endif 1540 return features; 1541 } 1542 #endif 1543 1544 // 1545 #ifdef ENABLE_CLASSIC 1546 1547 // returns true if channel was finalized 1548 static bool l2cap_run_for_classic_channel(l2cap_channel_t * channel){ 1549 1550 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1551 uint8_t config_options[18]; 1552 #else 1553 uint8_t config_options[10]; 1554 #endif 1555 1556 switch (channel->state){ 1557 1558 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1559 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 1560 if (!hci_can_send_acl_packet_now(channel->con_handle)) return false; 1561 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 1562 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 1563 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONN_RESP_PEND); 1564 l2cap_send_classic_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, 1565 channel->local_cid, channel->remote_cid, 1, 0); 1566 } 1567 break; 1568 1569 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1570 if (!hci_can_send_command_packet_now()) break; 1571 // send connection request - set state first 1572 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 1573 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 1574 (void)memcpy(l2cap_outgoing_classic_addr, channel->address, 6); 1575 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, hci_get_allow_role_switch()); 1576 break; 1577 1578 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 1579 if (!hci_can_send_acl_packet_now(channel->con_handle)) return false; 1580 channel->state = L2CAP_STATE_INVALID; 1581 l2cap_send_classic_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, 1582 channel->local_cid, channel->remote_cid, channel->reason, 0); 1583 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 1584 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1585 l2cap_free_channel_entry(channel); 1586 channel = NULL; 1587 break; 1588 1589 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 1590 if (!hci_can_send_acl_packet_now(channel->con_handle)) return false; 1591 channel->state = L2CAP_STATE_CONFIG; 1592 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1593 l2cap_send_classic_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, 1594 channel->local_cid, channel->remote_cid, 0, 0); 1595 break; 1596 1597 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 1598 if (!hci_can_send_acl_packet_now(channel->con_handle)) return false; 1599 // success, start l2cap handshake 1600 channel->local_sig_id = l2cap_next_sig_id(); 1601 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 1602 l2cap_send_classic_signaling_packet(channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, 1603 channel->psm, channel->local_cid); 1604 l2cap_start_rtx(channel); 1605 break; 1606 1607 case L2CAP_STATE_CONFIG: 1608 if (!hci_can_send_acl_packet_now(channel->con_handle)) return false; 1609 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1610 // fallback to basic mode if ERTM requested but not not supported by remote 1611 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1612 if (!l2cap_ertm_mode(channel)){ 1613 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_ERTM_BUFFER_RELEASED); 1614 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1615 } 1616 } 1617 #endif 1618 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 1619 uint16_t flags = 0; 1620 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1621 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 1622 flags = 1; 1623 } else { 1624 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 1625 } 1626 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 1627 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 1628 l2cap_send_classic_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, 1629 channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 1630 1, &channel->unknown_option); 1631 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1632 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED){ 1633 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 1634 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 1635 uint16_t options_size = l2cap_setup_options_ertm_response(channel, config_options); 1636 l2cap_send_classic_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, 1637 channel->remote_cid, flags, 1638 L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS, options_size, 1639 &config_options); 1640 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_ERTM){ 1641 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_ERTM); 1642 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1643 uint16_t options_size = l2cap_setup_options_ertm_response(channel, config_options); 1644 l2cap_send_classic_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, 1645 channel->remote_cid, flags, L2CAP_CONF_RESULT_SUCCESS, 1646 options_size, &config_options); 1647 #endif 1648 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 1649 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1650 uint16_t options_size = l2cap_setup_options_mtu_response(channel, config_options); 1651 l2cap_send_classic_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, 1652 channel->remote_cid, flags, L2CAP_CONF_RESULT_SUCCESS, 1653 options_size, &config_options); 1654 } else { 1655 l2cap_send_classic_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, 1656 channel->remote_cid, flags, L2CAP_CONF_RESULT_SUCCESS, 0, NULL); 1657 } 1658 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1659 } 1660 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 1661 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1662 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 1663 channel->local_sig_id = l2cap_next_sig_id(); 1664 uint16_t options_size = l2cap_setup_options_request(channel, config_options); 1665 l2cap_send_classic_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, 1666 channel->remote_cid, 0, options_size, &config_options); 1667 l2cap_start_rtx(channel); 1668 } 1669 if (l2cap_channel_ready_for_open(channel)){ 1670 channel->state = L2CAP_STATE_OPEN; 1671 l2cap_emit_channel_opened(channel, 0); // success 1672 } 1673 break; 1674 1675 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 1676 if (!hci_can_send_acl_packet_now(channel->con_handle)) return false; 1677 channel->state = L2CAP_STATE_INVALID; 1678 l2cap_send_classic_signaling_packet(channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, 1679 channel->local_cid, channel->remote_cid); 1680 // we don't start an RTX timer for a disconnect - there's no point in closing the channel if the other side doesn't respond :) 1681 l2cap_finalize_channel_close(channel); // -- remove from list 1682 channel = NULL; 1683 break; 1684 1685 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1686 if (!hci_can_send_acl_packet_now(channel->con_handle)) return false; 1687 channel->local_sig_id = l2cap_next_sig_id(); 1688 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 1689 l2cap_send_classic_signaling_packet(channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, 1690 channel->remote_cid, channel->local_cid); 1691 break; 1692 default: 1693 break; 1694 } 1695 1696 // handle channel finalize on L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE and L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE 1697 return channel == NULL; 1698 } 1699 1700 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1701 static void l2cap_run_for_classic_channel_ertm(l2cap_channel_t * channel){ 1702 1703 // ERTM mode 1704 if (channel->mode != L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION) return; 1705 1706 // check if we can still send 1707 if (channel->con_handle == HCI_CON_HANDLE_INVALID) return; 1708 if (!hci_can_send_acl_packet_now(channel->con_handle)) return; 1709 1710 if (channel->send_supervisor_frame_receiver_ready){ 1711 channel->send_supervisor_frame_receiver_ready = 0; 1712 log_info("Send S-Frame: RR %u, final %u", channel->req_seq, channel->set_final_bit_after_packet_with_poll_bit_set); 1713 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY, 0, channel->set_final_bit_after_packet_with_poll_bit_set, channel->req_seq); 1714 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1715 l2cap_ertm_send_supervisor_frame(channel, control); 1716 return; 1717 } 1718 if (channel->send_supervisor_frame_receiver_ready_poll){ 1719 channel->send_supervisor_frame_receiver_ready_poll = 0; 1720 log_info("Send S-Frame: RR %u with poll=1 ", channel->req_seq); 1721 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY, 1, 0, channel->req_seq); 1722 l2cap_ertm_send_supervisor_frame(channel, control); 1723 return; 1724 } 1725 if (channel->send_supervisor_frame_receiver_not_ready){ 1726 channel->send_supervisor_frame_receiver_not_ready = 0; 1727 log_info("Send S-Frame: RNR %u", channel->req_seq); 1728 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY, 0, 0, channel->req_seq); 1729 l2cap_ertm_send_supervisor_frame(channel, control); 1730 return; 1731 } 1732 if (channel->send_supervisor_frame_reject){ 1733 channel->send_supervisor_frame_reject = 0; 1734 log_info("Send S-Frame: REJ %u", channel->req_seq); 1735 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT, 0, 0, channel->req_seq); 1736 l2cap_ertm_send_supervisor_frame(channel, control); 1737 return; 1738 } 1739 if (channel->send_supervisor_frame_selective_reject){ 1740 channel->send_supervisor_frame_selective_reject = 0; 1741 log_info("Send S-Frame: SREJ %u", channel->expected_tx_seq); 1742 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT, 0, channel->set_final_bit_after_packet_with_poll_bit_set, channel->expected_tx_seq); 1743 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1744 l2cap_ertm_send_supervisor_frame(channel, control); 1745 return; 1746 } 1747 1748 if (channel->srej_active){ 1749 int i; 1750 for (i=0;i<channel->num_tx_buffers;i++){ 1751 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[i]; 1752 if (tx_state->retransmission_requested) { 1753 tx_state->retransmission_requested = 0; 1754 uint8_t final = channel->set_final_bit_after_packet_with_poll_bit_set; 1755 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1756 l2cap_ertm_send_information_frame(channel, i, final); 1757 break; 1758 } 1759 } 1760 if (i == channel->num_tx_buffers){ 1761 // no retransmission request found 1762 channel->srej_active = 0; 1763 } else { 1764 // packet was sent 1765 return; 1766 } 1767 } 1768 } 1769 #endif /* ERTM */ 1770 #endif /* Classic */ 1771 1772 static void l2cap_run_signaling_response(void) { 1773 1774 // check pending signaling responses 1775 while (l2cap_signaling_responses_pending){ 1776 1777 hci_con_handle_t handle = l2cap_signaling_responses[0].handle; 1778 1779 if (!hci_can_send_acl_packet_now(handle)) break; 1780 1781 uint8_t sig_id = l2cap_signaling_responses[0].sig_id; 1782 uint8_t response_code = l2cap_signaling_responses[0].code; 1783 uint16_t result = l2cap_signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT, REJECT_SM_PAIRING, L2CAP_CREDIT_BASED_CONNECTION_REQUEST 1784 uint8_t buffer[2]; // REJECT_SM_PAIRING 1785 uint16_t source_cid = l2cap_signaling_responses[0].cid; // CONNECTION_REQUEST, REJECT_SM_PAIRING 1786 #ifdef ENABLE_CLASSIC 1787 uint16_t info_type = l2cap_signaling_responses[0].data; // INFORMATION_REQUEST 1788 #endif 1789 #ifdef ENABLE_L2CAP_ENHANCED_DATA_CHANNELS 1790 uint8_t num_channels = l2cap_signaling_responses[0].cid >> 8; // L2CAP_CREDIT_BASED_CONNECTION_REQUEST 1791 uint16_t signaling_cid = (uint16_t) l2cap_signaling_responses[0].cid & 0xff; // L2CAP_CREDIT_BASED_CONNECTION_REQUEST, L2CAP_CREDIT_BASED_CONNECTION_REQUEST 1792 #endif 1793 1794 // remove first item before sending (to avoid sending response mutliple times) 1795 l2cap_signaling_responses_pending--; 1796 int i; 1797 for (i=0; i < l2cap_signaling_responses_pending; i++){ 1798 (void)memcpy(&l2cap_signaling_responses[i], 1799 &l2cap_signaling_responses[i + 1], 1800 sizeof(l2cap_signaling_response_t)); 1801 } 1802 1803 switch (response_code){ 1804 #ifdef ENABLE_CLASSIC 1805 case CONNECTION_REQUEST: 1806 l2cap_send_classic_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, source_cid, 0, result, 0); 1807 break; 1808 case ECHO_REQUEST: 1809 l2cap_send_classic_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 1810 break; 1811 case INFORMATION_REQUEST: 1812 switch (info_type){ 1813 case L2CAP_INFO_TYPE_CONNECTIONLESS_MTU: { 1814 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 1815 l2cap_send_classic_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 0, 1816 sizeof(connectionless_mtu), &connectionless_mtu); 1817 } 1818 break; 1819 case L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED: { 1820 uint32_t features = l2cap_extended_features_mask(); 1821 l2cap_send_classic_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 0, 1822 sizeof(features), &features); 1823 } 1824 break; 1825 case L2CAP_INFO_TYPE_FIXED_CHANNELS_SUPPORTED: { 1826 uint8_t map[8]; 1827 memset(map, 0, 8); 1828 // L2CAP Signaling Channel (bit 1) + Connectionless reception (bit 2) 1829 map[0] = (1 << 1) | (1 << 2); 1830 #if defined(ENABLE_BLE) || defined (ENABLE_EXPLICIT_BR_EDR_SECURITY_MANAGER) 1831 // BR/EDR Security Manager (bit 7) 1832 map[0] |= (1 << 7); 1833 #endif 1834 l2cap_send_classic_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 0, 1835 sizeof(map), &map); 1836 } 1837 break; 1838 default: 1839 // all other types are not supported 1840 l2cap_send_classic_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 1, 0, NULL); 1841 break; 1842 } 1843 break; 1844 case COMMAND_REJECT: 1845 l2cap_send_classic_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 1846 break; 1847 #endif 1848 #ifdef ENABLE_BLE 1849 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1850 l2cap_send_le_signaling_packet(handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, sig_id, 0, 0, 0, 0, result); 1851 break; 1852 case COMMAND_REJECT_LE: 1853 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 1854 break; 1855 #endif 1856 #ifdef ENABLE_L2CAP_ENHANCED_DATA_CHANNELS 1857 case L2CAP_CREDIT_BASED_CONNECTION_REQUEST: { 1858 // send variable size array or cids with each cid being zero 1859 uint16_t cids[6]; 1860 (void) memset(cids, 0xff, sizeof(cids)); 1861 (void) memset(cids, 0x00, num_channels * sizeof(uint16_t)); 1862 l2cap_send_general_signaling_packet(handle, signaling_cid, L2CAP_CREDIT_BASED_CONNECTION_RESPONSE, 1863 sig_id, 0, 0, 0, result, cids); 1864 break; 1865 } 1866 1867 case L2CAP_CREDIT_BASED_RECONFIGURE_REQUEST: 1868 l2cap_send_general_signaling_packet(handle, signaling_cid, L2CAP_CREDIT_BASED_RECONFIGURE_RESPONSE, 1869 sig_id, result); 1870 break; 1871 #endif 1872 case SM_PAIRING_FAILED: 1873 buffer[0] = SM_CODE_PAIRING_FAILED; 1874 buffer[1] = result; 1875 l2cap_send_connectionless(handle, source_cid, buffer, 2); 1876 break; 1877 default: 1878 // should not happen 1879 break; 1880 } 1881 } 1882 } 1883 1884 #ifdef ENABLE_CLASSIC 1885 static bool l2ap_run_information_requests(void){ 1886 // send l2cap information request if requested 1887 btstack_linked_list_iterator_t it; 1888 hci_connections_get_iterator(&it); 1889 uint8_t info_type; 1890 l2cap_information_state_t new_state; 1891 while(btstack_linked_list_iterator_has_next(&it)){ 1892 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1893 switch (connection->l2cap_state.information_state){ 1894 case L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST: 1895 info_type = L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED; 1896 new_state = L2CAP_INFORMATION_STATE_W4_EXTENDED_FEATURE_RESPONSE; 1897 break; 1898 case L2CAP_INFORMATION_STATE_W2_SEND_FIXED_CHANNELS_REQUEST: 1899 info_type = L2CAP_INFO_TYPE_FIXED_CHANNELS_SUPPORTED; 1900 new_state = L2CAP_INFORMATION_STATE_W4_FIXED_CHANNELS_RESPONSE; 1901 break; 1902 default: 1903 continue; 1904 } 1905 if (!hci_can_send_acl_packet_now(connection->con_handle)) break; 1906 1907 connection->l2cap_state.information_state = new_state; 1908 uint8_t sig_id = l2cap_next_sig_id(); 1909 l2cap_send_classic_signaling_packet(connection->con_handle, INFORMATION_REQUEST, sig_id, info_type); 1910 } 1911 return false; 1912 } 1913 #endif 1914 1915 #ifdef ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE 1916 static void l2cap_run_le_data_channels(void){ 1917 btstack_linked_list_iterator_t it; 1918 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1919 while (btstack_linked_list_iterator_has_next(&it)){ 1920 uint16_t mps; 1921 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1922 1923 if (channel->channel_type != L2CAP_CHANNEL_TYPE_LE_DATA_CHANNEL) continue; 1924 1925 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 1926 switch (channel->state){ 1927 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 1928 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1929 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 1930 // le psm, source cid, mtu, mps, initial credits 1931 channel->local_sig_id = l2cap_next_sig_id(); 1932 channel->credits_incoming = channel->new_credits_incoming; 1933 channel->new_credits_incoming = 0; 1934 mps = btstack_min(l2cap_max_le_mtu(), channel->local_mtu); 1935 l2cap_send_le_signaling_packet( channel->con_handle, LE_CREDIT_BASED_CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid, channel->local_mtu, mps, channel->credits_incoming); 1936 break; 1937 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 1938 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1939 // TODO: support larger MPS 1940 channel->state = L2CAP_STATE_OPEN; 1941 channel->credits_incoming = channel->new_credits_incoming; 1942 channel->new_credits_incoming = 0; 1943 mps = btstack_min(l2cap_max_le_mtu(), channel->local_mtu); 1944 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->local_mtu, mps, channel->credits_incoming, 0); 1945 // notify client 1946 l2cap_emit_le_channel_opened(channel, 0); 1947 break; 1948 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 1949 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1950 channel->state = L2CAP_STATE_INVALID; 1951 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); 1952 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 1953 btstack_linked_list_iterator_remove(&it); 1954 l2cap_free_channel_entry(channel); 1955 break; 1956 case L2CAP_STATE_OPEN: 1957 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1958 if (channel->new_credits_incoming){ 1959 l2cap_credit_based_send_credits(channel); 1960 } 1961 break; 1962 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1963 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1964 channel->local_sig_id = l2cap_next_sig_id(); 1965 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 1966 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 1967 break; 1968 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 1969 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1970 channel->state = L2CAP_STATE_INVALID; 1971 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 1972 l2cap_le_finialize_channel_close(channel); // -- remove from list 1973 break; 1974 default: 1975 break; 1976 } 1977 } 1978 } 1979 #endif 1980 1981 #ifdef ENABLE_L2CAP_ENHANCED_DATA_CHANNELS 1982 1983 // 11BH22222 1984 static void l2cap_emit_enhanced_data_channel_opened(l2cap_channel_t *channel, uint8_t status) { 1985 log_info("opened enhanced channel status 0x%x addr_type %u addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x local_mtu %u, remote_mtu %u", 1986 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 1987 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 1988 uint8_t event[23]; 1989 event[0] = L2CAP_EVENT_DATA_CHANNEL_OPENED; 1990 event[1] = sizeof(event) - 2u; 1991 event[2] = status; 1992 event[3] = channel->address_type; 1993 reverse_bd_addr(channel->address, &event[4]); 1994 little_endian_store_16(event, 10, channel->con_handle); 1995 event[12] = (channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING) ? 1 : 0; 1996 little_endian_store_16(event, 13, channel->psm); 1997 little_endian_store_16(event, 15, channel->local_cid); 1998 little_endian_store_16(event, 17, channel->remote_cid); 1999 little_endian_store_16(event, 19, channel->local_mtu); 2000 little_endian_store_16(event, 21, channel->remote_mtu); 2001 hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event)); 2002 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2003 } 2004 2005 static void l2cap_emit_enhanced_data_channel_reconfigure_complete(l2cap_channel_t *channel, uint16_t result) { 2006 // emit event 2007 uint8_t event[6]; 2008 event[0] = L2CAP_EVENT_DATA_CHANNEL_RECONFIGURATION_COMPLETE; 2009 event[1] = sizeof(event) - 2; 2010 little_endian_store_16(event, 2, channel->local_cid); 2011 little_endian_store_16(event, 4, result); 2012 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2013 } 2014 2015 static void l2cap_run_enhanced_data_channels(void) { 2016 hci_con_handle_t con_handle = HCI_CON_HANDLE_INVALID; 2017 // num max channels + 1 for signaling pdu generator 2018 uint16_t cids[L2CAP_ENHANCED_DATA_CHANNEL_MAX_CID_ARRAY_SIZE + 1]; 2019 uint8_t num_cids = 0; 2020 uint8_t sig_id; 2021 uint16_t spsm; 2022 L2CAP_STATE matching_state; 2023 bool match_remote_sig_cid; 2024 uint8_t result = 0; 2025 uint16_t local_mtu; 2026 uint16_t initial_credits; 2027 uint16_t signaling_cid; 2028 L2CAP_STATE new_state; 2029 2030 // pick first channel that needs to send a combined signaling pdu and setup collection via break 2031 // then collect all others that belong to the same pdu 2032 btstack_linked_list_iterator_t it; 2033 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2034 while (btstack_linked_list_iterator_has_next(&it)) { 2035 l2cap_channel_t *channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2036 if (channel->channel_type != L2CAP_CHANNEL_TYPE_ENHANCED_DATA_CHANNEL) continue; 2037 if (con_handle == HCI_CON_HANDLE_INVALID) { 2038 switch (channel->state) { 2039 case L2CAP_STATE_WILL_SEND_ENHANCED_CONNECTION_REQUEST: 2040 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 2041 local_mtu = channel->local_mtu; 2042 spsm = channel->psm; 2043 result = channel->reason; 2044 initial_credits = channel->credits_incoming; 2045 sig_id = channel->local_sig_id; 2046 new_state = L2CAP_STATE_WAIT_ENHANCED_CONNECTION_RESPONSE; 2047 match_remote_sig_cid = false; 2048 break; 2049 case L2CAP_STATE_WILL_SEND_ENHANCED_CONNECTION_RESPONSE: 2050 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 2051 local_mtu = channel->local_mtu; 2052 initial_credits = channel->credits_incoming; 2053 sig_id = channel->remote_sig_id; 2054 new_state = L2CAP_STATE_OPEN; 2055 match_remote_sig_cid = true; 2056 break; 2057 case L2CAP_STATE_WILL_SEND_EHNANCED_RENEGOTIATION_REQUEST: 2058 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 2059 sig_id = channel->local_sig_id; 2060 local_mtu = channel->renegotiate_mtu; 2061 new_state = L2CAP_STATE_WAIT_ENHANCED_RENEGOTIATION_RESPONSE; 2062 match_remote_sig_cid = false; 2063 break; 2064 case L2CAP_STATE_OPEN: 2065 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 2066 if (channel->new_credits_incoming) { 2067 l2cap_credit_based_send_credits(channel); 2068 } 2069 continue; 2070 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 2071 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 2072 channel->local_sig_id = l2cap_next_sig_id(); 2073 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 2074 signaling_cid = channel->address_type == BD_ADDR_TYPE_ACL ? L2CAP_CID_SIGNALING : L2CAP_CID_SIGNALING_LE; 2075 l2cap_send_general_signaling_packet(channel->con_handle, signaling_cid, DISCONNECTION_REQUEST, 2076 channel->local_sig_id, channel->remote_cid, channel->local_cid); 2077 continue; 2078 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 2079 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 2080 channel->state = L2CAP_STATE_INVALID; 2081 signaling_cid = channel->address_type == BD_ADDR_TYPE_ACL ? L2CAP_CID_SIGNALING : L2CAP_CID_SIGNALING_LE; 2082 l2cap_send_general_signaling_packet(channel->con_handle, signaling_cid, DISCONNECTION_RESPONSE, 2083 channel->remote_sig_id, channel->local_cid, 2084 channel->remote_cid); 2085 l2cap_le_finialize_channel_close(channel); // -- remove from list 2086 continue; 2087 default: 2088 continue; 2089 } 2090 2091 // channel picked - setup cid array and collect info 2092 (void) memset(cids, 0xff, sizeof(cids)); 2093 (void) memset(cids, 0, channel->num_cids * sizeof(uint16_t)); 2094 matching_state = channel->state; 2095 con_handle = channel->con_handle; 2096 signaling_cid = channel->address_type == BD_ADDR_TYPE_ACL ? L2CAP_CID_SIGNALING : L2CAP_CID_SIGNALING_LE; 2097 num_cids = channel->num_cids; 2098 2099 } else { 2100 // check if it matches first channel by state, con_handle, and signaling id 2101 if (matching_state != channel->state) continue; 2102 if (channel->con_handle != con_handle) continue; 2103 if (match_remote_sig_cid) { 2104 if (channel->remote_sig_id != sig_id) continue; 2105 } else { 2106 if (channel->local_sig_id != sig_id) continue; 2107 } 2108 } 2109 2110 // add this cid 2111 cids[channel->cid_index] = channel->local_cid; 2112 2113 // set new state 2114 channel->state = new_state; 2115 2116 // handle open for L2CAP_STATE_WILL_SEND_ENHANCED_CONNECTION_RESPONSE 2117 if (matching_state == L2CAP_STATE_WILL_SEND_ENHANCED_CONNECTION_RESPONSE) { 2118 if (channel->reason == 0) { 2119 l2cap_emit_enhanced_data_channel_opened(channel, ERROR_CODE_SUCCESS); 2120 } else { 2121 result = channel->reason; 2122 btstack_linked_list_iterator_remove(&it); 2123 btstack_memory_l2cap_channel_free(channel); 2124 } 2125 } 2126 } 2127 2128 if (con_handle != HCI_CON_HANDLE_INVALID) { 2129 // TODO: get MTU for both BR/EDR and LE 2130 uint16_t mps = btstack_min(l2cap_enhanced_mps_max, btstack_min(l2cap_max_le_mtu(), local_mtu)); 2131 switch (matching_state) { 2132 case L2CAP_STATE_WILL_SEND_ENHANCED_CONNECTION_REQUEST: 2133 log_info("send combined connection request for %u cids", num_cids); 2134 l2cap_send_general_signaling_packet(con_handle, signaling_cid, L2CAP_CREDIT_BASED_CONNECTION_REQUEST, 2135 sig_id, spsm, local_mtu, mps, initial_credits, cids); 2136 break; 2137 case L2CAP_STATE_WILL_SEND_ENHANCED_CONNECTION_RESPONSE: 2138 log_info("send combined connection response for %u cids", num_cids); 2139 l2cap_send_general_signaling_packet(con_handle, signaling_cid, L2CAP_CREDIT_BASED_CONNECTION_RESPONSE, 2140 sig_id, local_mtu, mps, initial_credits, result, cids); 2141 break; 2142 case L2CAP_STATE_WILL_SEND_EHNANCED_RENEGOTIATION_REQUEST: 2143 log_info("send combined renegotiation request for %u cids", num_cids); 2144 l2cap_send_general_signaling_packet(con_handle, signaling_cid, L2CAP_CREDIT_BASED_RECONFIGURE_REQUEST, 2145 sig_id, local_mtu, mps, cids); 2146 break; 2147 default: 2148 break; 2149 } 2150 } 2151 } 2152 #endif 2153 2154 // MARK: L2CAP_RUN 2155 // process outstanding signaling tasks 2156 static void l2cap_run(void){ 2157 2158 // log_info("l2cap_run: entered"); 2159 l2cap_run_signaling_response(); 2160 2161 #ifdef ENABLE_CLASSIC 2162 bool done = l2ap_run_information_requests(); 2163 if (done) return; 2164 #endif 2165 2166 #if defined(ENABLE_CLASSIC) || defined(ENABLE_BLE) 2167 btstack_linked_list_iterator_t it; 2168 #endif 2169 2170 #ifdef ENABLE_CLASSIC 2171 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2172 while (btstack_linked_list_iterator_has_next(&it)){ 2173 2174 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2175 2176 if (channel->channel_type != L2CAP_CHANNEL_TYPE_CLASSIC) continue; 2177 2178 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 2179 bool finalized = l2cap_run_for_classic_channel(channel); 2180 2181 if (!finalized) { 2182 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2183 l2cap_run_for_classic_channel_ertm(channel); 2184 #endif 2185 } 2186 } 2187 #endif 2188 2189 #ifdef ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE 2190 l2cap_run_le_data_channels(); 2191 #endif 2192 2193 #ifdef ENABLE_L2CAP_ENHANCED_DATA_CHANNELS 2194 l2cap_run_enhanced_data_channels(); 2195 #endif 2196 2197 #ifdef ENABLE_BLE 2198 // send l2cap con paramter update if necessary 2199 hci_connections_get_iterator(&it); 2200 while(btstack_linked_list_iterator_has_next(&it)){ 2201 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 2202 if ((connection->address_type != BD_ADDR_TYPE_LE_PUBLIC) && (connection->address_type != BD_ADDR_TYPE_LE_RANDOM)) continue; 2203 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 2204 switch (connection->le_con_parameter_update_state){ 2205 case CON_PARAMETER_UPDATE_SEND_REQUEST: 2206 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 2207 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, l2cap_next_sig_id(), 2208 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 2209 break; 2210 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 2211 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 2212 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 2213 break; 2214 case CON_PARAMETER_UPDATE_DENY: 2215 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 2216 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 2217 break; 2218 default: 2219 break; 2220 } 2221 } 2222 #endif 2223 2224 if (l2cap_call_notify_channel_in_run){ 2225 l2cap_call_notify_channel_in_run = false; 2226 l2cap_notify_channel_can_send(); 2227 } 2228 2229 // log_info("l2cap_run: exit"); 2230 } 2231 2232 #ifdef ENABLE_CLASSIC 2233 static void l2cap_ready_to_connect(l2cap_channel_t * channel){ 2234 2235 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2236 // assumption: outgoing connection 2237 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 2238 // ERTM requested: trigger information request if not already started then wait for response 2239 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 2240 switch (connection->l2cap_state.information_state){ 2241 case L2CAP_INFORMATION_STATE_DONE: 2242 break; 2243 case L2CAP_INFORMATION_STATE_IDLE: 2244 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 2245 /* fall through */ 2246 default: 2247 channel->state = L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES; 2248 return; 2249 } 2250 } 2251 #endif 2252 2253 // fine, go ahead 2254 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 2255 } 2256 2257 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 2258 if ((channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE) || (channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION)) { 2259 log_info("connection complete con_handle %04x - for channel %p cid 0x%04x", (int) con_handle, channel, channel->local_cid); 2260 channel->con_handle = con_handle; 2261 // query remote features if pairing is required 2262 if (channel->required_security_level > LEVEL_0){ 2263 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 2264 hci_remote_features_query(con_handle); 2265 } else { 2266 l2cap_ready_to_connect(channel); 2267 } 2268 } 2269 } 2270 2271 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 2272 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 2273 // double check if all feature pages are complete 2274 2275 bool security_required = channel->required_security_level > LEVEL_0; 2276 2277 // abort if Secure Connections Only Mode with legacy connection 2278 if (security_required && gap_get_secure_connections_only_mode() && gap_secure_connection(channel->con_handle) == 0){ 2279 l2cap_handle_channel_open_failed(channel, L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY); 2280 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2281 l2cap_free_channel_entry(channel); 2282 return; 2283 } 2284 2285 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING) != 0){ 2286 2287 // Core V5.2, Vol 3, Part C, 5.2.2.2 - Security Mode 4 2288 // When a remote device attempts to access a service offered by a Bluetooth device that is in security mode 4 2289 // and a sufficient link key exists and authentication has not been performed the local device shall authenticate 2290 // the remote device and enable encryption after the channel establishment request is received but before a channel 2291 // establishment confirmation (L2CAP_ConnectRsp with result code of 0x0000 or a higher-level channel establishment 2292 // confirmation such as that of RFCOMM) is sent. 2293 2294 // If the remote device has indicated support for Secure Simple Pairing, a channel establishment request is 2295 // received for a service other than SDP, and encryption has not yet been enabled, then the local device shall 2296 // disconnect the ACL link with error code 0x05 - Authentication Failure. 2297 2298 // => Disconnect if l2cap request received in mode 4 and ssp supported, non-sdp psm, not encrypted, no link key available 2299 if ((gap_get_security_mode() == GAP_SECURITY_MODE_4) 2300 && gap_ssp_supported_on_both_sides(channel->con_handle) 2301 && (channel->psm != PSM_SDP) 2302 && (gap_encryption_key_size(channel->con_handle) == 0) 2303 && (gap_bonded(channel->con_handle) == false)){ 2304 hci_disconnect_security_block(channel->con_handle); 2305 return; 2306 } 2307 2308 // incoming: assert security requirements 2309 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 2310 if (channel->required_security_level <= gap_security_level(channel->con_handle)){ 2311 l2cap_handle_security_level_incoming_sufficient(channel); 2312 } else { 2313 // send connection pending if not already done 2314 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONN_RESP_PEND) == 0){ 2315 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 2316 } 2317 gap_request_security_level(channel->con_handle, channel->required_security_level); 2318 } 2319 } else { 2320 // outgoing: we have been waiting for remote supported features 2321 if (security_required){ 2322 // request security level 2323 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 2324 gap_request_security_level(channel->con_handle, channel->required_security_level); 2325 } else { 2326 l2cap_ready_to_connect(channel); 2327 } 2328 } 2329 } 2330 #endif 2331 2332 #ifdef L2CAP_USES_CHANNELS 2333 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, l2cap_channel_type_t channel_type, bd_addr_t address, bd_addr_type_t address_type, 2334 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 2335 2336 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 2337 if (!channel) { 2338 return NULL; 2339 } 2340 2341 // fill in 2342 channel->packet_handler = packet_handler; 2343 channel->channel_type = channel_type; 2344 bd_addr_copy(channel->address, address); 2345 channel->address_type = address_type; 2346 channel->psm = psm; 2347 channel->local_mtu = local_mtu; 2348 channel->remote_mtu = L2CAP_DEFAULT_MTU; 2349 channel->required_security_level = security_level; 2350 2351 // 2352 channel->local_cid = l2cap_next_local_cid(); 2353 channel->con_handle = HCI_CON_HANDLE_INVALID; 2354 2355 // set initial state 2356 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 2357 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 2358 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 2359 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 2360 2361 log_info("create channel %p, local_cid 0x%04x", channel, channel->local_cid); 2362 2363 return channel; 2364 } 2365 2366 static void l2cap_free_channel_entry(l2cap_channel_t * channel){ 2367 log_info("free channel %p, local_cid 0x%04x", channel, channel->local_cid); 2368 // assert all timers are stopped 2369 l2cap_stop_rtx(channel); 2370 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2371 l2cap_ertm_stop_retransmission_timer(channel); 2372 l2cap_ertm_stop_monitor_timer(channel); 2373 #endif 2374 // free memory 2375 btstack_memory_l2cap_channel_free(channel); 2376 } 2377 #endif 2378 2379 #ifdef ENABLE_CLASSIC 2380 2381 /** 2382 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 2383 * @param packet_handler 2384 * @param address 2385 * @param psm 2386 * @param mtu 2387 * @param local_cid 2388 */ 2389 2390 uint8_t l2cap_create_channel(btstack_packet_handler_t channel_packet_handler, bd_addr_t address, uint16_t psm, uint16_t mtu, uint16_t * out_local_cid){ 2391 // limit MTU to the size of our outgoing HCI buffer 2392 uint16_t local_mtu = btstack_min(mtu, l2cap_max_mtu()); 2393 2394 // determine security level based on psm 2395 const gap_security_level_t security_level = l2cap_security_level_0_allowed_for_PSM(psm) ? LEVEL_0 : gap_get_security_level(); 2396 log_info("create channel addr %s psm 0x%x mtu %u -> local mtu %u, sec level %u", bd_addr_to_str(address), psm, mtu, local_mtu, (int) security_level); 2397 2398 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, L2CAP_CHANNEL_TYPE_CLASSIC, address, BD_ADDR_TYPE_ACL, psm, local_mtu, security_level); 2399 if (!channel) { 2400 return BTSTACK_MEMORY_ALLOC_FAILED; 2401 } 2402 2403 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2404 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2405 #endif 2406 2407 // add to connections list 2408 btstack_linked_list_add_tail(&l2cap_channels, (btstack_linked_item_t *) channel); 2409 2410 // store local_cid 2411 if (out_local_cid){ 2412 *out_local_cid = channel->local_cid; 2413 } 2414 2415 // state: L2CAP_STATE_WILL_SEND_CREATE_CONNECTION 2416 2417 // check if hci connection is already usable, 2418 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_ACL); 2419 if (conn && conn->state == OPEN){ 2420 // simulate connection complete 2421 l2cap_handle_connection_complete(conn->con_handle, channel); 2422 2423 // state: L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES or L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST 2424 2425 // simulate if remote supported features if requested and already received 2426 if ((channel->state == L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) && hci_remote_features_available(conn->con_handle)) { 2427 // simulate remote features received 2428 l2cap_handle_remote_supported_features_received(channel); 2429 } 2430 } 2431 2432 l2cap_run(); 2433 2434 return ERROR_CODE_SUCCESS; 2435 } 2436 2437 void l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 2438 log_info("disconnect local_cid 0x%x reason 0x%x", local_cid, reason); 2439 UNUSED(reason); 2440 // find channel for local_cid 2441 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 2442 if (channel) { 2443 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2444 } 2445 // process 2446 l2cap_run(); 2447 } 2448 2449 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 2450 // mark all channels before emitting open events as these could trigger new connetion requests to the same device 2451 btstack_linked_list_iterator_t it; 2452 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2453 while (btstack_linked_list_iterator_has_next(&it)){ 2454 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2455 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 2456 if (bd_addr_cmp( channel->address, address) != 0) continue; 2457 // channel for this address found 2458 switch (channel->state){ 2459 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 2460 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 2461 channel->state = L2CAP_STATE_EMIT_OPEN_FAILED_AND_DISCARD; 2462 break; 2463 default: 2464 break; 2465 } 2466 } 2467 // emit and free marked entries. restart loop to deal with list changes 2468 int done = 0; 2469 while (!done) { 2470 done = 1; 2471 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2472 while (btstack_linked_list_iterator_has_next(&it)){ 2473 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2474 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 2475 if (channel->state == L2CAP_STATE_EMIT_OPEN_FAILED_AND_DISCARD){ 2476 done = 0; 2477 // failure, forward error code 2478 l2cap_handle_channel_open_failed(channel, status); 2479 // discard channel 2480 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2481 l2cap_free_channel_entry(channel); 2482 break; 2483 } 2484 } 2485 } 2486 2487 } 2488 2489 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 2490 btstack_linked_list_iterator_t it; 2491 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2492 while (btstack_linked_list_iterator_has_next(&it)){ 2493 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2494 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 2495 if ( ! bd_addr_cmp( channel->address, address) ){ 2496 l2cap_handle_connection_complete(handle, channel); 2497 } 2498 } 2499 // process 2500 l2cap_run(); 2501 } 2502 #endif 2503 2504 static bool l2cap_channel_ready_to_send(l2cap_channel_t * channel){ 2505 switch (channel->channel_type){ 2506 #ifdef ENABLE_CLASSIC 2507 case L2CAP_CHANNEL_TYPE_CLASSIC: 2508 if (channel->state != L2CAP_STATE_OPEN) return false; 2509 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2510 // send if we have more data and remote windows isn't full yet 2511 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION) { 2512 if (channel->unacked_frames >= btstack_min(channel->num_stored_tx_frames, channel->remote_tx_window_size)) return false; 2513 return hci_can_send_acl_classic_packet_now() != 0; 2514 } 2515 #endif 2516 if (!channel->waiting_for_can_send_now) return false; 2517 return (hci_can_send_acl_classic_packet_now() != 0); 2518 case L2CAP_CHANNEL_TYPE_CONNECTIONLESS: 2519 if (!channel->waiting_for_can_send_now) return false; 2520 return hci_can_send_acl_classic_packet_now() != 0; 2521 #endif 2522 #ifdef ENABLE_BLE 2523 case L2CAP_CHANNEL_TYPE_FIXED: 2524 if (!channel->waiting_for_can_send_now) return false; 2525 return hci_can_send_acl_le_packet_now() != 0; 2526 #ifdef ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE 2527 case L2CAP_CHANNEL_TYPE_LE_DATA_CHANNEL: 2528 if (channel->state != L2CAP_STATE_OPEN) return false; 2529 if (channel->send_sdu_buffer == NULL) return false; 2530 if (channel->credits_outgoing == 0u) return false; 2531 return hci_can_send_acl_le_packet_now() != 0; 2532 #endif 2533 #endif 2534 #ifdef ENABLE_L2CAP_ENHANCED_DATA_CHANNELS 2535 case L2CAP_CHANNEL_TYPE_ENHANCED_DATA_CHANNEL: 2536 if (channel->state != L2CAP_STATE_OPEN) return false; 2537 if (channel->send_sdu_buffer == NULL) return false; 2538 if (channel->credits_outgoing == 0u) return false; 2539 if (channel->address_type == BD_ADDR_TYPE_ACL) { 2540 return hci_can_send_acl_classic_packet_now() != 0; 2541 } else { 2542 return hci_can_send_acl_le_packet_now() != 0; 2543 } 2544 #endif 2545 default: 2546 return false; 2547 } 2548 } 2549 2550 static void l2cap_channel_trigger_send(l2cap_channel_t * channel){ 2551 switch (channel->channel_type){ 2552 #ifdef ENABLE_CLASSIC 2553 case L2CAP_CHANNEL_TYPE_CLASSIC: 2554 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2555 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION) { 2556 l2cap_ertm_channel_send_information_frame(channel); 2557 return; 2558 } 2559 #endif 2560 channel->waiting_for_can_send_now = 0; 2561 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 2562 break; 2563 case L2CAP_CHANNEL_TYPE_CONNECTIONLESS: 2564 channel->waiting_for_can_send_now = 0; 2565 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 2566 break; 2567 #endif 2568 #ifdef ENABLE_BLE 2569 case L2CAP_CHANNEL_TYPE_FIXED: 2570 channel->waiting_for_can_send_now = 0; 2571 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 2572 break; 2573 #endif 2574 #ifdef ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE 2575 case L2CAP_CHANNEL_TYPE_LE_DATA_CHANNEL: 2576 l2cap_credit_based_send_pdu(channel); 2577 break; 2578 #endif 2579 #ifdef ENABLE_L2CAP_ENHANCED_DATA_CHANNELS 2580 case L2CAP_CHANNEL_TYPE_ENHANCED_DATA_CHANNEL: 2581 l2cap_credit_based_send_pdu(channel); 2582 break; 2583 #endif 2584 default: 2585 break; 2586 } 2587 } 2588 2589 static void l2cap_notify_channel_can_send(void){ 2590 bool done = false; 2591 while (!done){ 2592 done = true; 2593 btstack_linked_list_iterator_t it; 2594 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2595 while (btstack_linked_list_iterator_has_next(&it)){ 2596 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2597 bool ready = l2cap_channel_ready_to_send(channel); 2598 if (!ready) continue; 2599 2600 // requeue channel for fairness 2601 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2602 btstack_linked_list_add_tail(&l2cap_channels, (btstack_linked_item_t *) channel); 2603 2604 // trigger sending 2605 l2cap_channel_trigger_send(channel); 2606 2607 // exit inner loop as we just broke the iterator, but try again 2608 done = false; 2609 break; 2610 } 2611 } 2612 } 2613 2614 #ifdef L2CAP_USES_CHANNELS 2615 2616 static int l2cap_send_open_failed_on_hci_disconnect(l2cap_channel_t * channel){ 2617 // open cannot fail for for incoming connections 2618 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING) return 0; 2619 2620 // check state 2621 switch (channel->state){ 2622 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 2623 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 2624 case L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES: 2625 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 2626 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 2627 case L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES: 2628 case L2CAP_STATE_WAIT_CONNECT_RSP: 2629 case L2CAP_STATE_CONFIG: 2630 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 2631 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 2632 case L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE: 2633 case L2CAP_STATE_EMIT_OPEN_FAILED_AND_DISCARD: 2634 return 1; 2635 2636 case L2CAP_STATE_OPEN: 2637 case L2CAP_STATE_CLOSED: 2638 case L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES: 2639 case L2CAP_STATE_WAIT_DISCONNECT: 2640 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_INSUFFICIENT_SECURITY: 2641 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 2642 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 2643 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 2644 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 2645 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 2646 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 2647 case L2CAP_STATE_INVALID: 2648 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 2649 return 0; 2650 2651 default: 2652 // get a "warning" about new states 2653 btstack_assert(false); 2654 return 0; 2655 } 2656 } 2657 #endif 2658 2659 #ifdef ENABLE_CLASSIC 2660 static void l2cap_handle_hci_disconnect_event(l2cap_channel_t * channel){ 2661 if (l2cap_send_open_failed_on_hci_disconnect(channel)){ 2662 l2cap_handle_channel_open_failed(channel, L2CAP_CONNECTION_BASEBAND_DISCONNECT); 2663 } else { 2664 l2cap_handle_channel_closed(channel); 2665 } 2666 l2cap_free_channel_entry(channel); 2667 } 2668 #endif 2669 2670 #ifdef ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE 2671 static void l2cap_handle_hci_le_disconnect_event(l2cap_channel_t * channel){ 2672 if (l2cap_send_open_failed_on_hci_disconnect(channel)){ 2673 l2cap_emit_le_channel_opened(channel, L2CAP_CONNECTION_BASEBAND_DISCONNECT); 2674 } else { 2675 l2cap_emit_le_channel_closed(channel); 2676 } 2677 l2cap_free_channel_entry(channel); 2678 } 2679 #endif 2680 2681 #ifdef ENABLE_CLASSIC 2682 static void l2cap_check_classic_timeout(hci_con_handle_t handle){ 2683 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) { 2684 return; 2685 } 2686 if (hci_authentication_active_for_handle(handle)) { 2687 return; 2688 } 2689 bool hci_con_used = false; 2690 btstack_linked_list_iterator_t it; 2691 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2692 while (btstack_linked_list_iterator_has_next(&it)){ 2693 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2694 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 2695 if (channel->con_handle != handle) continue; 2696 hci_con_used = true; 2697 break; 2698 } 2699 if (hci_con_used) { 2700 return; 2701 } 2702 if (!hci_can_send_command_packet_now()) { 2703 return; 2704 } 2705 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 2706 } 2707 2708 static void l2cap_handle_features_complete(hci_con_handle_t handle){ 2709 if (hci_remote_features_available(handle) == false){ 2710 return; 2711 } 2712 btstack_linked_list_iterator_t it; 2713 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2714 while (btstack_linked_list_iterator_has_next(&it)){ 2715 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2716 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 2717 if (channel->con_handle != handle) continue; 2718 log_info("remote supported features, channel %p, cid %04x - state %u", channel, channel->local_cid, channel->state); 2719 l2cap_handle_remote_supported_features_received(channel); 2720 } 2721 } 2722 2723 static void l2cap_handle_security_level_incoming_sufficient(l2cap_channel_t * channel){ 2724 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2725 l2cap_emit_incoming_connection(channel); 2726 } 2727 2728 static void l2cap_handle_security_level(hci_con_handle_t handle, gap_security_level_t actual_level){ 2729 log_info("security level update for handle 0x%04x", handle); 2730 2731 // trigger l2cap information requests 2732 if (actual_level > LEVEL_0){ 2733 hci_connection_t * hci_connection = hci_connection_for_handle(handle); 2734 btstack_assert(hci_connection != NULL); 2735 if (hci_connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_IDLE){ 2736 hci_connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 2737 } 2738 } 2739 2740 btstack_linked_list_iterator_t it; 2741 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2742 while (btstack_linked_list_iterator_has_next(&it)){ 2743 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2744 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 2745 if (channel->con_handle != handle) continue; 2746 2747 gap_security_level_t required_level = channel->required_security_level; 2748 2749 log_info("channel %p, cid %04x - state %u: actual %u >= required %u?", channel, channel->local_cid, channel->state, actual_level, required_level); 2750 2751 switch (channel->state){ 2752 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 2753 if (actual_level >= required_level){ 2754 l2cap_handle_security_level_incoming_sufficient(channel); 2755 } else { 2756 channel->reason = 0x0003; // security block 2757 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 2758 } 2759 break; 2760 2761 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 2762 if (actual_level >= required_level){ 2763 l2cap_ready_to_connect(channel); 2764 } else { 2765 // security level insufficient, report error and free channel 2766 l2cap_handle_channel_open_failed(channel, L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY); 2767 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2768 l2cap_free_channel_entry(channel); 2769 } 2770 break; 2771 2772 default: 2773 break; 2774 } 2775 } 2776 } 2777 #endif 2778 2779 #ifdef L2CAP_USES_CHANNELS 2780 static void l2cap_handle_disconnection_complete(hci_con_handle_t handle){ 2781 // collect channels to close 2782 btstack_linked_list_t channels_to_close = NULL; 2783 btstack_linked_list_iterator_t it; 2784 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2785 while (btstack_linked_list_iterator_has_next(&it)) { 2786 l2cap_channel_t *channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2787 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 2788 if (channel->con_handle != handle) continue; 2789 btstack_linked_list_iterator_remove(&it); 2790 btstack_linked_list_add(&channels_to_close, (btstack_linked_item_t *) channel); 2791 } 2792 // send l2cap open failed or closed events for all channels on this handle and free them 2793 btstack_linked_list_iterator_init(&it, &channels_to_close); 2794 while (btstack_linked_list_iterator_has_next(&it)) { 2795 l2cap_channel_t *channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2796 btstack_linked_list_iterator_remove(&it); 2797 switch(channel->channel_type){ 2798 #ifdef ENABLE_CLASSIC 2799 case L2CAP_CHANNEL_TYPE_CLASSIC: 2800 l2cap_handle_hci_disconnect_event(channel); 2801 break; 2802 #endif 2803 #ifdef ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE 2804 case L2CAP_CHANNEL_TYPE_LE_DATA_CHANNEL: 2805 l2cap_handle_hci_le_disconnect_event(channel); 2806 break; 2807 #endif 2808 #ifdef ENABLE_L2CAP_ENHANCED_DATA_CHANNELS 2809 case L2CAP_CHANNEL_TYPE_ENHANCED_DATA_CHANNEL: 2810 switch (channel->state) { 2811 case L2CAP_STATE_WILL_SEND_ENHANCED_CONNECTION_REQUEST: 2812 case L2CAP_STATE_WAIT_ENHANCED_CONNECTION_RESPONSE: 2813 // emit open failed if disconnected before connection complete 2814 l2cap_emit_enhanced_data_channel_opened(channel, L2CAP_CONNECTION_BASEBAND_DISCONNECT); 2815 break; 2816 case L2CAP_STATE_WILL_SEND_EHNANCED_RENEGOTIATION_REQUEST: 2817 case L2CAP_STATE_WAIT_ENHANCED_RENEGOTIATION_RESPONSE: 2818 // emit reconfigure failure - result = 0xffff 2819 l2cap_emit_enhanced_data_channel_reconfigure_complete(channel, 0xffff); 2820 break; 2821 default: 2822 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_DATA_CHANNEL_CLOSED); 2823 break; 2824 } 2825 l2cap_free_channel_entry(channel); 2826 break; 2827 #endif 2828 default: 2829 break; 2830 } 2831 } 2832 } 2833 #endif 2834 2835 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 2836 2837 UNUSED(packet_type); // ok: registered with hci_event_callback_registration 2838 UNUSED(cid); // ok: there is no channel 2839 UNUSED(size); // ok: fixed format events read from HCI buffer 2840 2841 #ifdef ENABLE_CLASSIC 2842 bd_addr_t address; 2843 gap_security_level_t security_level; 2844 #endif 2845 #ifdef L2CAP_USES_CHANNELS 2846 hci_con_handle_t handle; 2847 #endif 2848 2849 switch(hci_event_packet_get_type(packet)){ 2850 2851 // Notify channel packet handler if they can send now 2852 case HCI_EVENT_TRANSPORT_PACKET_SENT: 2853 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 2854 case BTSTACK_EVENT_NR_CONNECTIONS_CHANGED: 2855 l2cap_call_notify_channel_in_run = true; 2856 break; 2857 2858 case HCI_EVENT_COMMAND_STATUS: 2859 #ifdef ENABLE_CLASSIC 2860 // check command status for create connection for errors 2861 if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_create_connection)){ 2862 // cache outgoing address and reset 2863 (void)memcpy(address, l2cap_outgoing_classic_addr, 6); 2864 memset(l2cap_outgoing_classic_addr, 0, 6); 2865 // error => outgoing connection failed 2866 uint8_t status = hci_event_command_status_get_status(packet); 2867 if (status){ 2868 l2cap_handle_connection_failed_for_addr(address, status); 2869 } 2870 } 2871 #endif 2872 l2cap_run(); // try sending signaling packets first 2873 break; 2874 2875 #ifdef ENABLE_CLASSIC 2876 // handle connection complete events 2877 case HCI_EVENT_CONNECTION_COMPLETE: 2878 reverse_bd_addr(&packet[5], address); 2879 if (packet[2] == 0){ 2880 handle = little_endian_read_16(packet, 3); 2881 l2cap_handle_connection_success_for_addr(address, handle); 2882 } else { 2883 l2cap_handle_connection_failed_for_addr(address, packet[2]); 2884 } 2885 break; 2886 2887 // handle successful create connection cancel command 2888 case HCI_EVENT_COMMAND_COMPLETE: 2889 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 2890 if (packet[5] == 0){ 2891 reverse_bd_addr(&packet[6], address); 2892 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 2893 l2cap_handle_connection_failed_for_addr(address, 0x16); 2894 } 2895 } 2896 l2cap_run(); // try sending signaling packets first 2897 break; 2898 #endif 2899 2900 #ifdef L2CAP_USES_CHANNELS 2901 // handle disconnection complete events 2902 case HCI_EVENT_DISCONNECTION_COMPLETE: 2903 handle = little_endian_read_16(packet, 3); 2904 l2cap_handle_disconnection_complete(handle); 2905 break; 2906 #endif 2907 2908 // HCI Connection Timeouts 2909 #ifdef ENABLE_CLASSIC 2910 case L2CAP_EVENT_TIMEOUT_CHECK: 2911 handle = little_endian_read_16(packet, 2); 2912 l2cap_check_classic_timeout(handle); 2913 break; 2914 2915 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 2916 case HCI_EVENT_READ_REMOTE_EXTENDED_FEATURES_COMPLETE: 2917 handle = little_endian_read_16(packet, 3); 2918 l2cap_handle_features_complete(handle); 2919 break; 2920 2921 case GAP_EVENT_SECURITY_LEVEL: 2922 handle = little_endian_read_16(packet, 2); 2923 security_level = (gap_security_level_t) packet[4]; 2924 l2cap_handle_security_level(handle, security_level); 2925 break; 2926 #endif 2927 default: 2928 break; 2929 } 2930 2931 l2cap_run(); 2932 } 2933 2934 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t cid, uint16_t data){ 2935 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indicates the connection was refused." 2936 if (l2cap_signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 2937 l2cap_signaling_responses[l2cap_signaling_responses_pending].handle = handle; 2938 l2cap_signaling_responses[l2cap_signaling_responses_pending].code = code; 2939 l2cap_signaling_responses[l2cap_signaling_responses_pending].sig_id = sig_id; 2940 l2cap_signaling_responses[l2cap_signaling_responses_pending].cid = cid; 2941 l2cap_signaling_responses[l2cap_signaling_responses_pending].data = data; 2942 l2cap_signaling_responses_pending++; 2943 l2cap_run(); 2944 } 2945 } 2946 2947 #ifdef ENABLE_CLASSIC 2948 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 2949 switch (channel->state){ 2950 case L2CAP_STATE_CONFIG: 2951 case L2CAP_STATE_OPEN: 2952 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 2953 case L2CAP_STATE_WAIT_DISCONNECT: 2954 break; 2955 default: 2956 // ignore in other states 2957 return; 2958 } 2959 2960 channel->remote_sig_id = identifier; 2961 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 2962 l2cap_run(); 2963 } 2964 2965 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 2966 2967 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 2968 l2cap_service_t *service = l2cap_get_service(psm); 2969 if (!service) { 2970 // 0x0002 PSM not supported 2971 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 2972 return; 2973 } 2974 2975 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 2976 if (!hci_connection) { 2977 // 2978 log_error("no hci_connection for handle %u", handle); 2979 return; 2980 } 2981 2982 // alloc structure 2983 gap_security_level_t required_level = service->required_security_level; 2984 if (gap_get_secure_connections_only_mode() && (required_level != LEVEL_0)){ 2985 required_level = LEVEL_4; 2986 } 2987 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, L2CAP_CHANNEL_TYPE_CLASSIC, hci_connection->address, BD_ADDR_TYPE_ACL, 2988 psm, service->mtu, required_level); 2989 if (!channel){ 2990 // 0x0004 No resources available 2991 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 2992 return; 2993 } 2994 2995 channel->con_handle = handle; 2996 channel->remote_cid = source_cid; 2997 channel->remote_sig_id = sig_id; 2998 2999 // limit local mtu to max acl packet length - l2cap header 3000 if (channel->local_mtu > l2cap_max_mtu()) { 3001 channel->local_mtu = l2cap_max_mtu(); 3002 } 3003 3004 // set initial state 3005 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 3006 channel->state_var = L2CAP_CHANNEL_STATE_VAR_INCOMING; 3007 3008 // add to connections list 3009 btstack_linked_list_add_tail(&l2cap_channels, (btstack_linked_item_t *) channel); 3010 3011 // 3012 if (required_level > LEVEL_0){ 3013 // send conn resp pending if remote supported features have not been received yet 3014 if (hci_remote_features_available(handle)) { 3015 l2cap_handle_remote_supported_features_received(channel); 3016 } else { 3017 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 3018 hci_remote_features_query(handle); 3019 } 3020 } else { 3021 l2cap_handle_security_level_incoming_sufficient(channel); 3022 } 3023 } 3024 3025 void l2cap_accept_connection(uint16_t local_cid){ 3026 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 3027 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 3028 if (!channel) { 3029 log_error("accept called but local_cid 0x%x not found", local_cid); 3030 return; 3031 } 3032 3033 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 3034 // configure L2CAP Basic mode 3035 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 3036 #endif 3037 3038 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 3039 3040 // process 3041 l2cap_run(); 3042 } 3043 3044 void l2cap_decline_connection(uint16_t local_cid){ 3045 log_info("decline local_cid 0x%x", local_cid); 3046 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 3047 if (!channel) { 3048 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 3049 return; 3050 } 3051 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 3052 channel->reason = 0x04; // no resources available 3053 l2cap_run(); 3054 } 3055 3056 // @pre command len is valid, see check in l2cap_signaling_handler_channel 3057 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 3058 3059 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 3060 uint8_t use_fcs = 1; 3061 #endif 3062 3063 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 3064 3065 uint16_t flags = little_endian_read_16(command, 6); 3066 if (flags & 1) { 3067 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 3068 } 3069 3070 // accept the other's configuration options 3071 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 3072 uint16_t pos = 8; 3073 while (pos < end_pos){ 3074 uint8_t option_hint = command[pos] >> 7; 3075 uint8_t option_type = command[pos] & 0x7f; 3076 // log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 3077 pos++; 3078 uint8_t length = command[pos++]; 3079 // MTU { type(8): 1, len(8):2, MTU(16) } 3080 if ((option_type == L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT) && (length == 2)){ 3081 channel->remote_mtu = little_endian_read_16(command, pos); 3082 log_info("Remote MTU %u", channel->remote_mtu); 3083 if (channel->remote_mtu > l2cap_max_mtu()){ 3084 log_info("Remote MTU %u larger than outgoing buffer, only using MTU = %u", channel->remote_mtu, l2cap_max_mtu()); 3085 channel->remote_mtu = l2cap_max_mtu(); 3086 } 3087 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 3088 } 3089 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 3090 if ((option_type == L2CAP_CONFIG_OPTION_TYPE_FLUSH_TIMEOUT) && (length == 2)){ 3091 channel->flush_timeout = little_endian_read_16(command, pos); 3092 log_info("Flush timeout: %u ms", channel->flush_timeout); 3093 } 3094 3095 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 3096 // Retransmission and Flow Control Option 3097 if (option_type == L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL && length == 9){ 3098 l2cap_channel_mode_t mode = (l2cap_channel_mode_t) command[pos]; 3099 switch(channel->mode){ 3100 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 3101 // Store remote config 3102 channel->remote_tx_window_size = command[pos+1]; 3103 channel->remote_max_transmit = command[pos+2]; 3104 channel->remote_retransmission_timeout_ms = little_endian_read_16(command, pos + 3); 3105 channel->remote_monitor_timeout_ms = little_endian_read_16(command, pos + 5); 3106 channel->remote_mps = little_endian_read_16(command, pos + 7); 3107 log_info("FC&C config: tx window: %u, max transmit %u, retrans timeout %u, monitor timeout %u, mps %u", 3108 channel->remote_tx_window_size, 3109 channel->remote_max_transmit, 3110 channel->remote_retransmission_timeout_ms, 3111 channel->remote_monitor_timeout_ms, 3112 channel->remote_mps); 3113 // If ERTM mandatory, but remote doens't offer ERTM -> disconnect 3114 if (channel->ertm_mandatory && mode != L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 3115 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3116 } else { 3117 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_ERTM); 3118 } 3119 break; 3120 case L2CAP_CHANNEL_MODE_BASIC: 3121 switch (mode){ 3122 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 3123 // remote asks for ERTM, but we want basic mode. disconnect if this happens a second time 3124 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED){ 3125 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3126 } 3127 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED); 3128 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 3129 break; 3130 default: // case L2CAP_CHANNEL_MODE_BASIC: 3131 // TODO store and evaluate configuration 3132 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_ERTM); 3133 break; 3134 } 3135 break; 3136 default: 3137 break; 3138 } 3139 } 3140 if (option_type == L2CAP_CONFIG_OPTION_TYPE_FRAME_CHECK_SEQUENCE && length == 1){ 3141 use_fcs = command[pos]; 3142 } 3143 #endif 3144 // check for unknown options 3145 if ((option_hint == 0) && ((option_type < L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT) || (option_type > L2CAP_CONFIG_OPTION_TYPE_EXTENDED_WINDOW_SIZE))){ 3146 log_info("l2cap cid %u, unknown option 0x%02x", channel->local_cid, option_type); 3147 channel->unknown_option = option_type; 3148 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 3149 } 3150 pos += length; 3151 } 3152 3153 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 3154 // "FCS" has precedence over "No FCS" 3155 uint8_t update = channel->fcs_option || use_fcs; 3156 log_info("local fcs: %u, remote fcs: %u -> %u", channel->fcs_option, use_fcs, update); 3157 channel->fcs_option = update; 3158 // If ERTM mandatory, but remote didn't send Retransmission and Flowcontrol options -> disconnect 3159 if (((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_ERTM) == 0) & (channel->ertm_mandatory)){ 3160 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3161 } 3162 #endif 3163 } 3164 3165 // @pre command len is valid, see check in l2cap_signaling_handler_channel 3166 static void l2cap_signaling_handle_configure_response(l2cap_channel_t *channel, uint8_t result, uint8_t *command){ 3167 log_info("l2cap_signaling_handle_configure_response"); 3168 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 3169 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 3170 uint16_t pos = 10; 3171 while (pos < end_pos){ 3172 uint8_t option_hint = command[pos] >> 7; 3173 uint8_t option_type = command[pos] & 0x7f; 3174 // log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 3175 pos++; 3176 uint8_t length = command[pos++]; 3177 3178 // Retransmission and Flow Control Option 3179 if (option_type == L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL && length == 9){ 3180 switch (channel->mode){ 3181 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 3182 if (channel->ertm_mandatory){ 3183 // ?? 3184 } else { 3185 // On 'Reject - Unacceptable Parameters' to our optional ERTM request, fall back to BASIC mode 3186 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 3187 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_ERTM_BUFFER_RELEASED); 3188 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 3189 } 3190 } 3191 break; 3192 case L2CAP_CHANNEL_MODE_BASIC: 3193 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 3194 // On 'Reject - Unacceptable Parameters' to our Basic mode request, disconnect 3195 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3196 } 3197 break; 3198 default: 3199 break; 3200 } 3201 } 3202 3203 // check for unknown options 3204 if (option_hint == 0 && (option_type < L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT || option_type > L2CAP_CONFIG_OPTION_TYPE_EXTENDED_WINDOW_SIZE)){ 3205 log_info("l2cap cid %u, unknown option 0x%02x", channel->local_cid, option_type); 3206 channel->unknown_option = option_type; 3207 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 3208 } 3209 3210 pos += length; 3211 } 3212 #else 3213 UNUSED(channel); // ok: no code 3214 UNUSED(result); // ok: no code 3215 UNUSED(command); // ok: no code 3216 #endif 3217 } 3218 3219 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 3220 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 3221 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 3222 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 3223 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 3224 if (channel->state == L2CAP_STATE_OPEN) return 0; 3225 return 1; 3226 } 3227 3228 3229 // @pre command len is valid, see check in l2cap_signaling_handler_dispatch 3230 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 3231 3232 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 3233 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 3234 uint16_t cmd_len = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 3235 uint16_t result = 0; 3236 3237 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 3238 3239 // handle DISCONNECT REQUESTS seperately 3240 if (code == DISCONNECTION_REQUEST){ 3241 l2cap_handle_disconnect_request(channel, identifier); 3242 return; 3243 } 3244 3245 // @STATEMACHINE(l2cap) 3246 switch (channel->state) { 3247 3248 case L2CAP_STATE_WAIT_CONNECT_RSP: 3249 switch (code){ 3250 case CONNECTION_RESPONSE: 3251 if (cmd_len < 8){ 3252 // command imcomplete 3253 l2cap_register_signaling_response(channel->con_handle, COMMAND_REJECT, identifier, 0, L2CAP_REJ_CMD_UNKNOWN); 3254 break; 3255 } 3256 l2cap_stop_rtx(channel); 3257 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 3258 switch (result) { 3259 case 0: 3260 // successful connection 3261 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 3262 channel->state = L2CAP_STATE_CONFIG; 3263 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 3264 break; 3265 case 1: 3266 // connection pending. get some coffee, but start the ERTX 3267 l2cap_start_ertx(channel); 3268 break; 3269 default: 3270 // channel closed 3271 channel->state = L2CAP_STATE_CLOSED; 3272 // map l2cap connection response result to BTstack status enumeration 3273 l2cap_handle_channel_open_failed(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 3274 3275 // drop link key if security block 3276 if ((L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result) == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 3277 gap_drop_link_key_for_bd_addr(channel->address); 3278 } 3279 3280 // discard channel 3281 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 3282 l2cap_free_channel_entry(channel); 3283 break; 3284 } 3285 break; 3286 3287 default: 3288 //@TODO: implement other signaling packets 3289 break; 3290 } 3291 break; 3292 3293 case L2CAP_STATE_CONFIG: 3294 switch (code) { 3295 case CONFIGURE_REQUEST: 3296 if (cmd_len < 4){ 3297 // command incomplete 3298 l2cap_register_signaling_response(channel->con_handle, COMMAND_REJECT, identifier, 0, L2CAP_REJ_CMD_UNKNOWN); 3299 break; 3300 } 3301 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 3302 l2cap_signaling_handle_configure_request(channel, command); 3303 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 3304 // only done if continuation not set 3305 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 3306 } 3307 break; 3308 case CONFIGURE_RESPONSE: 3309 if (cmd_len < 6){ 3310 // command incomplete 3311 l2cap_register_signaling_response(channel->con_handle, COMMAND_REJECT, identifier, 0, L2CAP_REJ_CMD_UNKNOWN); 3312 break; 3313 } 3314 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 3315 l2cap_stop_rtx(channel); 3316 l2cap_signaling_handle_configure_response(channel, result, command); 3317 switch (result){ 3318 case 0: // success 3319 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 3320 break; 3321 case 4: // pending 3322 l2cap_start_ertx(channel); 3323 break; 3324 default: 3325 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 3326 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION && channel->ertm_mandatory){ 3327 // remote does not offer ertm but it's required 3328 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3329 break; 3330 } 3331 #endif 3332 // retry on negative result 3333 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 3334 break; 3335 } 3336 break; 3337 default: 3338 break; 3339 } 3340 if (l2cap_channel_ready_for_open(channel)){ 3341 3342 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 3343 // assert that packet can be stored in fragment buffers in ertm 3344 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 3345 uint16_t effective_mps = btstack_min(channel->remote_mps, channel->local_mps); 3346 uint16_t usable_mtu = channel->num_tx_buffers == 1 ? effective_mps : channel->num_tx_buffers * effective_mps - 2; 3347 if (usable_mtu < channel->remote_mtu){ 3348 log_info("Remote MTU %u > max storable ERTM packet, only using MTU = %u", channel->remote_mtu, usable_mtu); 3349 channel->remote_mtu = usable_mtu; 3350 } 3351 } 3352 #endif 3353 // for open: 3354 channel->state = L2CAP_STATE_OPEN; 3355 l2cap_emit_channel_opened(channel, 0); 3356 } 3357 break; 3358 3359 case L2CAP_STATE_WAIT_DISCONNECT: 3360 switch (code) { 3361 case DISCONNECTION_RESPONSE: 3362 l2cap_finalize_channel_close(channel); 3363 break; 3364 default: 3365 //@TODO: implement other signaling packets 3366 break; 3367 } 3368 break; 3369 3370 case L2CAP_STATE_CLOSED: 3371 // @TODO handle incoming requests 3372 break; 3373 3374 case L2CAP_STATE_OPEN: 3375 //@TODO: implement other signaling packets, e.g. re-configure 3376 break; 3377 default: 3378 break; 3379 } 3380 // log_info("new state %u", channel->state); 3381 } 3382 3383 #ifdef ENABLE_CLASSIC 3384 static void l2cap_handle_information_request_complete(hci_connection_t * connection){ 3385 3386 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_DONE; 3387 3388 // emit event 3389 uint8_t event[8]; 3390 event[0] = L2CAP_EVENT_INFORMATION_RESPONSE; 3391 event[1] = sizeof(event) - 2; 3392 little_endian_store_16(event, 2, connection->con_handle); 3393 little_endian_store_16(event, 4, connection->l2cap_state.extended_feature_mask); 3394 little_endian_store_16(event, 6, connection->l2cap_state.fixed_channels_supported); 3395 l2cap_emit_event(event, sizeof(event)); 3396 3397 // trigger connection request 3398 btstack_linked_list_iterator_t it; 3399 btstack_linked_list_iterator_init(&it, &l2cap_channels); 3400 while (btstack_linked_list_iterator_has_next(&it)){ 3401 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 3402 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 3403 if (channel->con_handle != connection->con_handle) continue; 3404 3405 // incoming connection: information request was triggered after user has accepted connection, 3406 // now: verify channel configuration, esp. if ertm will be mandatory 3407 if (channel->state == L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES){ 3408 // default: continue 3409 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 3410 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 3411 if ((channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION) && ((connection->l2cap_state.extended_feature_mask & 0x08) == 0)){ 3412 // ERTM not possible, select basic mode and release buffer 3413 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 3414 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_ERTM_BUFFER_RELEASED); 3415 3416 // bail if ERTM is mandatory 3417 if (channel->ertm_mandatory){ 3418 // We chose 'no resources available' for "ERTM mandatory but you don't even know ERTM exists" 3419 log_info("ERTM mandatory -> reject connection"); 3420 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 3421 channel->reason = 0x04; // no resources available 3422 } else { 3423 log_info("ERTM not supported by remote -> use Basic mode"); 3424 } 3425 } 3426 #endif 3427 continue; 3428 } 3429 3430 // outgoing connection: information request is triggered before connection request 3431 if (channel->state == L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES){ 3432 3433 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 3434 // if ERTM was requested, but is not listed in extended feature mask: 3435 if ((channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION) && ((connection->l2cap_state.extended_feature_mask & 0x08) == 0)){ 3436 3437 if (channel->ertm_mandatory){ 3438 // bail if ERTM is mandatory 3439 channel->state = L2CAP_STATE_CLOSED; 3440 // map l2cap connection response result to BTstack status enumeration 3441 l2cap_handle_channel_open_failed(channel, L2CAP_CONNECTION_RESPONSE_RESULT_ERTM_NOT_SUPPORTED); 3442 // discard channel 3443 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 3444 l2cap_free_channel_entry(channel); 3445 continue; 3446 3447 } else { 3448 // fallback to Basic mode 3449 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_ERTM_BUFFER_RELEASED); 3450 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 3451 } 3452 } 3453 #endif 3454 3455 // respond to connection request 3456 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 3457 continue; 3458 } 3459 } 3460 } 3461 #endif 3462 3463 // @pre command len is valid, see check in l2cap_acl_classic_handler 3464 static void l2cap_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command){ 3465 3466 hci_connection_t * connection; 3467 btstack_linked_list_iterator_t it; 3468 3469 // get code, signal identifier and command len 3470 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 3471 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 3472 uint16_t cmd_len = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 3473 3474 // general commands without an assigned channel 3475 switch(code) { 3476 3477 case CONNECTION_REQUEST: 3478 if (cmd_len == 4){ 3479 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 3480 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 3481 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 3482 } else { 3483 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 3484 } 3485 return; 3486 3487 case ECHO_REQUEST: 3488 l2cap_register_signaling_response(handle, code, sig_id, 0, 0); 3489 return; 3490 3491 case INFORMATION_REQUEST: 3492 if (cmd_len == 2) { 3493 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 3494 l2cap_register_signaling_response(handle, code, sig_id, 0, info_type); 3495 return; 3496 } 3497 break; 3498 3499 case INFORMATION_RESPONSE: 3500 connection = hci_connection_for_handle(handle); 3501 if (!connection) return; 3502 switch (connection->l2cap_state.information_state){ 3503 case L2CAP_INFORMATION_STATE_W4_EXTENDED_FEATURE_RESPONSE: 3504 // get extended features from response if valid 3505 if (cmd_len >= 6) { 3506 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 3507 uint16_t result = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 3508 if (result == 0 && info_type == L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED) { 3509 connection->l2cap_state.extended_feature_mask = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 3510 } 3511 log_info("extended features mask 0x%02x", connection->l2cap_state.extended_feature_mask); 3512 if ((connection->l2cap_state.extended_feature_mask & 0x80) != 0){ 3513 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_FIXED_CHANNELS_REQUEST; 3514 } else { 3515 // information request complete 3516 l2cap_handle_information_request_complete(connection); 3517 } 3518 } 3519 break; 3520 case L2CAP_INFORMATION_STATE_W4_FIXED_CHANNELS_RESPONSE: 3521 if (cmd_len >= 12) { 3522 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 3523 uint16_t result = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 3524 if (result == 0 && info_type == L2CAP_INFO_TYPE_FIXED_CHANNELS_SUPPORTED) { 3525 connection->l2cap_state.fixed_channels_supported = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 3526 } 3527 log_info("fixed channels mask 0x%02x", connection->l2cap_state.fixed_channels_supported); 3528 // information request complete 3529 l2cap_handle_information_request_complete(connection); 3530 } 3531 break; 3532 default: 3533 break; 3534 } 3535 return; 3536 3537 #ifdef ENABLE_L2CAP_ENHANCED_DATA_CHANNELS 3538 case L2CAP_CREDIT_BASED_CONNECTION_REQUEST: 3539 case L2CAP_CREDIT_BASED_CONNECTION_RESPONSE: 3540 case L2CAP_CREDIT_BASED_RECONFIGURE_REQUEST: 3541 case L2CAP_CREDIT_BASED_RECONFIGURE_RESPONSE: 3542 l2cap_enhanced_signaling_handler_dispatch(handle, L2CAP_CID_SIGNALING, command, sig_id); 3543 return; 3544 case L2CAP_FLOW_CONTROL_CREDIT_INDICATION: 3545 // return if valid 3546 if (l2cap_credit_based_handle_credit_indication(handle, command, cmd_len)) return; 3547 break; 3548 3549 case COMMAND_REJECT: 3550 btstack_linked_list_iterator_init(&it, &l2cap_channels); 3551 while (btstack_linked_list_iterator_has_next(&it)) { 3552 l2cap_channel_t *channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 3553 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 3554 if (channel->con_handle != handle) continue; 3555 if (channel->local_sig_id != sig_id) continue; 3556 if (channel->state != L2CAP_STATE_WAIT_ENHANCED_CONNECTION_RESPONSE) continue; 3557 3558 // open failed 3559 channel->state = L2CAP_STATE_CLOSED; 3560 l2cap_emit_enhanced_data_channel_opened(channel, 3561 ERROR_CODE_CONNECTION_REJECTED_DUE_TO_LIMITED_RESOURCES); 3562 // drop failed channel 3563 btstack_linked_list_iterator_remove(&it); 3564 l2cap_free_channel_entry(channel); 3565 } 3566 break; 3567 #endif 3568 3569 default: 3570 break; 3571 } 3572 3573 // Get potential destination CID 3574 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 3575 3576 // Find channel for this sig_id and connection handle 3577 btstack_linked_list_iterator_init(&it, &l2cap_channels); 3578 while (btstack_linked_list_iterator_has_next(&it)){ 3579 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 3580 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 3581 if (channel->con_handle != handle) continue; 3582 if (code & 1) { 3583 // match odd commands (responses) by previous signaling identifier 3584 if (channel->local_sig_id == sig_id) { 3585 l2cap_signaling_handler_channel(channel, command); 3586 return; 3587 } 3588 } else { 3589 // match even commands (requests) by local channel id 3590 if (channel->local_cid == dest_cid) { 3591 l2cap_signaling_handler_channel(channel, command); 3592 return; 3593 } 3594 } 3595 } 3596 3597 // send command reject 3598 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 3599 } 3600 #endif 3601 3602 #ifdef L2CAP_USES_CHANNELS 3603 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 3604 btstack_linked_list_iterator_t it; 3605 btstack_linked_list_iterator_init(&it, services); 3606 while (btstack_linked_list_iterator_has_next(&it)){ 3607 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 3608 if ( service->psm == psm){ 3609 return service; 3610 }; 3611 } 3612 return NULL; 3613 } 3614 #endif 3615 3616 #ifdef ENABLE_L2CAP_ENHANCED_DATA_CHANNELS 3617 3618 static uint8_t l2cap_enhanced_setup_channels(btstack_linked_list_t * channels, 3619 btstack_packet_handler_t packet_handler, uint8_t num_channels, 3620 hci_connection_t * connection, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 3621 uint8_t i; 3622 uint8_t status = ERROR_CODE_SUCCESS; 3623 for (i=0;i<num_channels;i++){ 3624 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, L2CAP_CHANNEL_TYPE_ENHANCED_DATA_CHANNEL, connection->address, connection->address_type, psm, mtu, security_level); 3625 if (!channel) { 3626 status = BTSTACK_MEMORY_ALLOC_FAILED; 3627 break; 3628 } 3629 channel->con_handle = connection->con_handle; 3630 btstack_linked_list_add_tail(channels, (btstack_linked_item_t *) channel); 3631 } 3632 3633 // free channels if not all allocated 3634 if (status != ERROR_CODE_SUCCESS){ 3635 while (true) { 3636 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_pop(channels); 3637 if (channel == NULL) break; 3638 l2cap_free_channel_entry(channel); 3639 } 3640 } 3641 3642 return status; 3643 } 3644 3645 static inline l2cap_service_t * l2cap_enhanced_get_service(uint16_t spsm){ 3646 return l2cap_get_service_internal(&l2cap_enhanced_services, spsm); 3647 } 3648 3649 static inline uint8_t l2cap_enhanced_status_for_result(uint16_t result) { 3650 switch (result) { 3651 case 0x0000: 3652 return ERROR_CODE_SUCCESS; 3653 case 0x0002: 3654 return L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_PSM; 3655 case 0x0004: 3656 return L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_RESOURCES; 3657 case 0x0005: 3658 case 0x0006: 3659 case 0x0007: 3660 case 0x0008: 3661 return L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY; 3662 default: 3663 // invalid Source CID, Source CID already allocated, unacceptable parameters 3664 return L2CAP_CONNECTION_RESPONSE_UNKNOWN_ERROR; 3665 } 3666 } 3667 3668 static int l2cap_enhanced_signaling_handler_dispatch(hci_con_handle_t handle, uint16_t signaling_cid, uint8_t *command, 3669 uint8_t sig_id) { 3670 3671 hci_connection_t *connection; 3672 btstack_linked_list_iterator_t it; 3673 l2cap_service_t *service; 3674 uint16_t spsm; 3675 uint8_t num_channels; 3676 uint16_t num_channels_and_signaling_cid; 3677 uint8_t i; 3678 uint16_t new_mtu; 3679 uint16_t new_mps; 3680 uint16_t initial_credits; 3681 uint16_t result; 3682 uint8_t status; 3683 3684 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 3685 uint16_t len = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 3686 log_info("enhanced dispatch: command 0x%02x, sig id %u, len %u", code, sig_id, len); 3687 3688 switch (code) { 3689 case L2CAP_CREDIT_BASED_CONNECTION_REQUEST: 3690 // check size 3691 if (len < 10u) return 0u; 3692 3693 // get hci connection, bail if not found (must not happen) 3694 connection = hci_connection_for_handle(handle); 3695 btstack_assert(connection != NULL); 3696 3697 // get num channels to establish 3698 num_channels = (len - 8) / sizeof(uint16_t); 3699 3700 // combine signaling cid and number channels for l2cap_register_signaling_response 3701 num_channels_and_signaling_cid = (num_channels << 8) | signaling_cid; 3702 3703 // check if service registered 3704 spsm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 3705 service = l2cap_enhanced_get_service(spsm); 3706 3707 if (service) { 3708 3709 uint16_t remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 3710 uint16_t remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 3711 uint16_t credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 3712 3713 // param: check remote mtu 3714 if (service->mtu > remote_mtu) { 3715 // 0x000B All connections refused – invalid parameters 3716 l2cap_register_signaling_response(handle, L2CAP_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 3717 num_channels_and_signaling_cid, 0x000C); 3718 return 1; 3719 } 3720 3721 // security: check authentication 3722 if (service->required_security_level >= LEVEL_3) { 3723 if (!gap_authenticated(handle)) { 3724 // 0x0005 Connection refused – insufficient authentication 3725 l2cap_register_signaling_response(handle, L2CAP_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 3726 num_channels_and_signaling_cid, 0x0005); 3727 return 1; 3728 } 3729 } 3730 3731 // security: check encryption 3732 // L2CAP.TS.p31 does not check for 0x0008 Connection refused - insufficient encryption which might be send for no encryption 3733 if (service->required_security_level >= LEVEL_2) { 3734 if (gap_encryption_key_size(handle) < 16) { 3735 // 0x0007 Connection refused – insufficient encryption key size 3736 l2cap_register_signaling_response(handle, L2CAP_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 3737 num_channels_and_signaling_cid, 0x0007); 3738 return 1; 3739 } 3740 } 3741 3742 // report the last result code != 0 3743 result = 0; 3744 // store one of the local cids for the event 3745 uint16_t a_local_cid = 0; 3746 for (i = 0; i < num_channels; i++) { 3747 3748 // check source cids 3749 uint16_t source_cid = little_endian_read_16(command, 12 + (i * 2)); 3750 if (source_cid < 0x40u) { 3751 // 0x0009 Connection refused - Invalid Source CID 3752 result = 0x0009; 3753 continue; 3754 } 3755 3756 // go through list of channels for this ACL connection and check if we get a match 3757 btstack_linked_list_iterator_init(&it, &l2cap_channels); 3758 bool source_cid_allocated = false; 3759 while (btstack_linked_list_iterator_has_next(&it)) { 3760 l2cap_channel_t *channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 3761 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 3762 if (channel->con_handle != handle) continue; 3763 if (channel->remote_cid != source_cid) continue; 3764 source_cid_allocated = true; 3765 break; 3766 } 3767 if (source_cid_allocated) { 3768 result = 0x00a; 3769 continue; 3770 } 3771 3772 // setup channel 3773 l2cap_channel_t *channel = l2cap_create_channel_entry(service->packet_handler, 3774 L2CAP_CHANNEL_TYPE_ENHANCED_DATA_CHANNEL, 3775 connection->address, 3776 connection->address_type, spsm, 3777 service->mtu, 3778 service->required_security_level); 3779 3780 if (channel == NULL) { 3781 // Some connections refused – insufficient resources available 3782 result = 0x004; 3783 continue; 3784 } 3785 3786 // setup state 3787 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 3788 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 3789 channel->con_handle = connection->con_handle; 3790 channel->remote_sig_id = sig_id; 3791 channel->remote_cid = source_cid; 3792 channel->remote_mtu = remote_mtu; 3793 channel->remote_mps = remote_mps; 3794 channel->credits_outgoing = credits_outgoing; 3795 channel->cid_index = i; 3796 channel->num_cids = num_channels; 3797 3798 // if more than one error, we can report any of them 3799 channel->reason = result; 3800 3801 btstack_linked_list_add_tail(&l2cap_channels, (btstack_linked_item_t *) channel); 3802 3803 a_local_cid = channel->local_cid; 3804 } 3805 3806 // if no channels have been created, all have been refused, and we can respond right away 3807 if (a_local_cid == 0) { 3808 l2cap_register_signaling_response(handle, L2CAP_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 3809 num_channels_and_signaling_cid, result); 3810 return 1; 3811 } 3812 3813 // emit incoming data connection event 3814 uint8_t event[16]; 3815 event[0] = L2CAP_EVENT_DATA_CHANNEL_INCOMING; 3816 event[1] = sizeof(event) - 2; 3817 event[2] = connection->address_type; 3818 reverse_bd_addr(connection->address, &event[3]); 3819 little_endian_store_16(event, 9, connection->con_handle); 3820 little_endian_store_16(event, 11, spsm); 3821 event[13] = num_channels; 3822 little_endian_store_16(event, 14, a_local_cid); 3823 hci_dump_packet(HCI_EVENT_PACKET, 0, event, sizeof(event)); 3824 (*service->packet_handler)(HCI_EVENT_PACKET, a_local_cid, event, sizeof(event)); 3825 3826 } else { 3827 // All connections refused – SPSM not supported 3828 l2cap_register_signaling_response(handle, L2CAP_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 3829 num_channels_and_signaling_cid, 0x0002); 3830 } 3831 return 1; 3832 3833 case L2CAP_CREDIT_BASED_CONNECTION_RESPONSE: 3834 // check size 3835 if (len < 10u) return 0u; 3836 3837 // get hci connection, ignore if not found 3838 connection = hci_connection_for_handle(handle); 3839 if (connection == NULL) return 0; 3840 3841 // get channel config: mtu, mps, initial credits, result 3842 new_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 3843 new_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 3844 initial_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 3845 result = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 3846 status = l2cap_enhanced_status_for_result(result); 3847 3848 // get num channels to modify 3849 num_channels = (len - 8) / sizeof(uint16_t); 3850 btstack_linked_list_iterator_init(&it, &l2cap_channels); 3851 while (btstack_linked_list_iterator_has_next(&it)) { 3852 l2cap_channel_t *channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 3853 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 3854 if (channel->con_handle != handle) continue; 3855 if (channel->local_sig_id != sig_id) continue; 3856 if (channel->state != L2CAP_STATE_WAIT_ENHANCED_CONNECTION_RESPONSE) continue; 3857 if (channel->cid_index < num_channels) { 3858 uint16_t remote_cid = little_endian_read_16(command, 12 + channel->cid_index * sizeof(uint16_t)); 3859 if (remote_cid != 0) { 3860 channel->state = L2CAP_STATE_OPEN; 3861 channel->remote_cid = remote_cid; 3862 channel->remote_mtu = new_mtu; 3863 channel->remote_mps = new_mps; 3864 channel->credits_outgoing = initial_credits; 3865 l2cap_emit_enhanced_data_channel_opened(channel, ERROR_CODE_SUCCESS); 3866 continue; 3867 } 3868 } 3869 // open failed 3870 l2cap_emit_enhanced_data_channel_opened(channel, status); 3871 // drop failed channel 3872 btstack_linked_list_iterator_remove(&it); 3873 btstack_memory_l2cap_channel_free(channel); 3874 } 3875 return 1; 3876 3877 case L2CAP_CREDIT_BASED_RECONFIGURE_REQUEST: 3878 // check minimal size 3879 if (len < 6) return 0u; 3880 3881 // get hci connection, bail if not found (must not happen) 3882 connection = hci_connection_for_handle(handle); 3883 btstack_assert(connection != NULL); 3884 3885 // get num channels to modify 3886 num_channels = (len - 4) / sizeof(uint16_t); 3887 3888 // get new mtu and mps 3889 new_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 3890 new_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 3891 3892 // validate request 3893 result = 0; 3894 for (i = 0; i < num_channels; i++) { 3895 // check cid 3896 uint16_t remote_cid = little_endian_read_16(command, 8 + (i * sizeof(uint16_t))); 3897 l2cap_channel_t *channel = l2cap_get_channel_for_remote_handle_and_cid(handle, remote_cid); 3898 if (channel == NULL) { 3899 // 0x0003 Reconfiguration failed - one or more Destination CIDs invalid 3900 result = 0x0003; 3901 break; 3902 } 3903 // check MTU is not reduced 3904 if (channel->remote_mtu > new_mtu) { 3905 // 0x0001 Reconfiguration failed - reduction in size of MTU not allowed 3906 result = 0x0001; 3907 break; 3908 } 3909 // check MPS reduction 3910 if ((num_channels > 1) && (channel->remote_mps > new_mps)) { 3911 // 0x002 Reconfiguration failed - reduction in size of MPS not allowed for more than one channel at a time 3912 result = 0x0002; 3913 break; 3914 } 3915 // check MPS valid 3916 if (new_mps < l2cap_enhanced_mps_min) { 3917 // 0x0002 Reconfiguration failed - other unacceptable parameters 3918 result = 0x0004; 3919 break; 3920 } 3921 } 3922 3923 // send reject 3924 if (result != 0) { 3925 l2cap_register_signaling_response(handle, L2CAP_CREDIT_BASED_RECONFIGURE_REQUEST, sig_id, signaling_cid, 3926 result); 3927 return 1; 3928 } 3929 3930 // update channels 3931 for (i = 0; i < num_channels; i++) { 3932 uint16_t remote_cid = little_endian_read_16(command, 8 + (i * sizeof(uint16_t))); 3933 l2cap_channel_t *channel = l2cap_get_channel_for_remote_handle_and_cid(handle, remote_cid); 3934 channel->remote_mps = new_mps; 3935 channel->remote_mtu = new_mtu; 3936 // emit event 3937 uint8_t event[8]; 3938 event[0] = L2CAP_EVENT_DATA_CHANNEL_RECONFIGURED; 3939 event[1] = sizeof(event) - 2; 3940 little_endian_store_16(event, 2, channel->local_cid); 3941 little_endian_store_16(event, 4, new_mtu); 3942 little_endian_store_16(event, 6, new_mps); 3943 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 3944 } 3945 3946 // send accept 3947 l2cap_register_signaling_response(handle, L2CAP_CREDIT_BASED_RECONFIGURE_REQUEST, sig_id, signaling_cid, 0); 3948 return 1; 3949 3950 case L2CAP_CREDIT_BASED_RECONFIGURE_RESPONSE: 3951 // check size 3952 if (len < 2u) return 0u; 3953 3954 result = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 3955 btstack_linked_list_iterator_init(&it, &l2cap_channels); 3956 while (btstack_linked_list_iterator_has_next(&it)) { 3957 l2cap_channel_t *channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 3958 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 3959 if (channel->con_handle != handle) continue; 3960 if (channel->local_sig_id != sig_id) continue; 3961 if (channel->state != L2CAP_STATE_WAIT_ENHANCED_RENEGOTIATION_RESPONSE) continue; 3962 // complete request 3963 if (result == 0) { 3964 channel->receive_sdu_buffer = channel->renegotiate_sdu_buffer; 3965 channel->local_mtu = channel->renegotiate_mtu; 3966 } 3967 channel->state = L2CAP_STATE_OPEN; 3968 // emit event 3969 l2cap_emit_enhanced_data_channel_reconfigure_complete(channel, result); 3970 } 3971 break; 3972 3973 default: 3974 btstack_unreachable(); 3975 break; 3976 } 3977 return 0; 3978 } 3979 3980 #endif 3981 3982 #ifdef ENABLE_BLE 3983 3984 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 3985 uint8_t event[6]; 3986 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 3987 event[1] = 4; 3988 little_endian_store_16(event, 2, con_handle); 3989 little_endian_store_16(event, 4, result); 3990 l2cap_emit_event(event, sizeof(event)); 3991 } 3992 3993 // @return valid 3994 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 3995 hci_connection_t * connection; 3996 uint16_t result; 3997 uint8_t event[12]; 3998 3999 #ifdef ENABLE_L2CAP_CREDIT_BASED_CHANNELS 4000 l2cap_channel_t * channel; 4001 btstack_linked_list_iterator_t it; 4002 #endif 4003 #ifdef ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE 4004 uint16_t local_cid; 4005 uint16_t le_psm; 4006 l2cap_service_t * service; 4007 uint16_t source_cid; 4008 #endif 4009 4010 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 4011 uint16_t len = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 4012 log_info("le dispatch: command 0x%02x, sig id %u, len %u", code, sig_id, len); 4013 4014 switch (code){ 4015 4016 case CONNECTION_PARAMETER_UPDATE_REQUEST: 4017 // check size 4018 if (len < 8u) return 0u; 4019 connection = hci_connection_for_handle(handle); 4020 if (connection != NULL){ 4021 if (connection->role != HCI_ROLE_MASTER){ 4022 // reject command without notifying upper layer when not in master role 4023 return 0; 4024 } 4025 le_connection_parameter_range_t existing_range; 4026 gap_get_connection_parameter_range(&existing_range); 4027 uint16_t le_conn_interval_min = little_endian_read_16(command,L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 4028 uint16_t le_conn_interval_max = little_endian_read_16(command,L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 4029 uint16_t le_conn_latency = little_endian_read_16(command,L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 4030 uint16_t le_supervision_timeout = little_endian_read_16(command,L2CAP_SIGNALING_COMMAND_DATA_OFFSET+6); 4031 4032 int update_parameter = gap_connection_parameter_range_included(&existing_range, le_conn_interval_min, le_conn_interval_max, le_conn_latency, le_supervision_timeout); 4033 if (update_parameter){ 4034 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 4035 connection->le_conn_interval_min = le_conn_interval_min; 4036 connection->le_conn_interval_max = le_conn_interval_max; 4037 connection->le_conn_latency = le_conn_latency; 4038 connection->le_supervision_timeout = le_supervision_timeout; 4039 } else { 4040 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 4041 } 4042 connection->le_con_param_update_identifier = sig_id; 4043 } 4044 4045 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 4046 event[1] = 8; 4047 little_endian_store_16(event, 2, handle); 4048 (void)memcpy(&event[4], &command[4], 8); 4049 l2cap_emit_event(event, sizeof(event)); 4050 break; 4051 4052 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 4053 // check size 4054 if (len < 2u) return 0u; 4055 result = little_endian_read_16(command, 4); 4056 l2cap_emit_connection_parameter_update_response(handle, result); 4057 break; 4058 4059 #ifdef ENABLE_L2CAP_ENHANCED_DATA_CHANNELS 4060 case L2CAP_CREDIT_BASED_CONNECTION_REQUEST: 4061 case L2CAP_CREDIT_BASED_CONNECTION_RESPONSE: 4062 case L2CAP_CREDIT_BASED_RECONFIGURE_REQUEST: 4063 case L2CAP_CREDIT_BASED_RECONFIGURE_RESPONSE: 4064 return l2cap_enhanced_signaling_handler_dispatch(handle, L2CAP_CID_SIGNALING_LE, command, sig_id); 4065 #endif 4066 4067 #ifdef ENABLE_L2CAP_CREDIT_BASED_CHANNELS 4068 case COMMAND_REJECT: 4069 btstack_linked_list_iterator_init(&it, &l2cap_channels); 4070 while (btstack_linked_list_iterator_has_next(&it)){ 4071 channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 4072 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 4073 if (channel->con_handle != handle) continue; 4074 if (channel->local_sig_id != sig_id) continue; 4075 #ifdef ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE 4076 // if received while waiting for le connection response, assume legacy device 4077 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 4078 channel->state = L2CAP_STATE_CLOSED; 4079 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 4080 l2cap_emit_le_channel_opened(channel, 0x0002); 4081 4082 // discard channel 4083 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 4084 l2cap_free_channel_entry(channel); 4085 continue; 4086 } 4087 #endif 4088 #ifdef ENABLE_L2CAP_ENHANCED_DATA_CHANNELS 4089 // if received while waiting for le connection response, assume legacy device 4090 if (channel->state == L2CAP_STATE_WAIT_ENHANCED_CONNECTION_RESPONSE){ 4091 channel->state = L2CAP_STATE_CLOSED; 4092 // treat as SPSM not supported 4093 l2cap_emit_enhanced_data_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_PSM); 4094 4095 // discard channel 4096 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 4097 l2cap_free_channel_entry(channel); 4098 continue; 4099 } 4100 #endif 4101 } 4102 break; 4103 #endif 4104 4105 #ifdef ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE 4106 case LE_CREDIT_BASED_CONNECTION_REQUEST: 4107 // check size 4108 if (len < 10u) return 0u; 4109 4110 // get hci connection, bail if not found (must not happen) 4111 connection = hci_connection_for_handle(handle); 4112 if (!connection) return 0; 4113 4114 // check if service registered 4115 le_psm = little_endian_read_16(command, 4); 4116 service = l2cap_le_get_service(le_psm); 4117 source_cid = little_endian_read_16(command, 6); 4118 4119 if (service){ 4120 if (source_cid < 0x40u){ 4121 // 0x0009 Connection refused - Invalid Source CID 4122 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0009); 4123 return 1; 4124 } 4125 4126 // go through list of channels for this ACL connection and check if we get a match 4127 btstack_linked_list_iterator_init(&it, &l2cap_channels); 4128 while (btstack_linked_list_iterator_has_next(&it)){ 4129 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 4130 if (!l2cap_is_dynamic_channel_type(a_channel->channel_type)) continue; 4131 if (a_channel->con_handle != handle) continue; 4132 if (a_channel->remote_cid != source_cid) continue; 4133 // 0x000a Connection refused - Source CID already allocated 4134 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x000a); 4135 return 1; 4136 } 4137 4138 // security: check encryption 4139 if (service->required_security_level >= LEVEL_2){ 4140 if (gap_encryption_key_size(handle) == 0){ 4141 // 0x0008 Connection refused - insufficient encryption 4142 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0008); 4143 return 1; 4144 } 4145 // anything less than 16 byte key size is insufficient 4146 if (gap_encryption_key_size(handle) < 16){ 4147 // 0x0007 Connection refused – insufficient encryption key size 4148 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0007); 4149 return 1; 4150 } 4151 } 4152 4153 // security: check authencation 4154 if (service->required_security_level >= LEVEL_3){ 4155 if (!gap_authenticated(handle)){ 4156 // 0x0005 Connection refused – insufficient authentication 4157 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0005); 4158 return 1; 4159 } 4160 } 4161 4162 // security: check authorization 4163 if (service->required_security_level >= LEVEL_4){ 4164 if (gap_authorization_state(handle) != AUTHORIZATION_GRANTED){ 4165 // 0x0006 Connection refused – insufficient authorization 4166 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0006); 4167 return 1; 4168 } 4169 } 4170 4171 // allocate channel 4172 channel = l2cap_create_channel_entry(service->packet_handler, L2CAP_CHANNEL_TYPE_LE_DATA_CHANNEL, connection->address, 4173 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 4174 if (!channel){ 4175 // 0x0004 Connection refused – no resources available 4176 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 4177 return 1; 4178 } 4179 4180 channel->con_handle = handle; 4181 channel->remote_cid = source_cid; 4182 channel->remote_sig_id = sig_id; 4183 channel->remote_mtu = little_endian_read_16(command, 8); 4184 channel->remote_mps = little_endian_read_16(command, 10); 4185 channel->credits_outgoing = little_endian_read_16(command, 12); 4186 4187 // set initial state 4188 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 4189 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 4190 4191 // add to connections list 4192 btstack_linked_list_add_tail(&l2cap_channels, (btstack_linked_item_t *) channel); 4193 4194 // post connection request event 4195 l2cap_emit_le_incoming_connection(channel); 4196 4197 } else { 4198 // Connection refused – LE_PSM not supported 4199 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 4200 } 4201 break; 4202 4203 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 4204 // check size 4205 if (len < 10u) return 0u; 4206 4207 // Find channel for this sig_id and connection handle 4208 channel = NULL; 4209 btstack_linked_list_iterator_init(&it, &l2cap_channels); 4210 while (btstack_linked_list_iterator_has_next(&it)){ 4211 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 4212 if (!l2cap_is_dynamic_channel_type(a_channel->channel_type)) continue; 4213 if (a_channel->con_handle != handle) continue; 4214 if (a_channel->local_sig_id != sig_id) continue; 4215 channel = a_channel; 4216 break; 4217 } 4218 if (!channel) break; 4219 4220 // cid + 0 4221 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 4222 if (result){ 4223 channel->state = L2CAP_STATE_CLOSED; 4224 // map l2cap connection response result to BTstack status enumeration 4225 l2cap_emit_le_channel_opened(channel, result); 4226 4227 // discard channel 4228 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 4229 l2cap_free_channel_entry(channel); 4230 break; 4231 } 4232 4233 // success 4234 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 4235 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 4236 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 4237 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 4238 channel->state = L2CAP_STATE_OPEN; 4239 l2cap_emit_le_channel_opened(channel, result); 4240 break; 4241 #endif 4242 4243 #ifdef ENABLE_L2CAP_CREDIT_BASED_CHANNELS 4244 case L2CAP_FLOW_CONTROL_CREDIT_INDICATION: 4245 return l2cap_credit_based_handle_credit_indication(handle, command, len) ? 1 : 0; 4246 4247 case DISCONNECTION_REQUEST: 4248 4249 // check size 4250 if (len < 4u) return 0u; 4251 4252 // find channel 4253 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 4254 channel = l2cap_get_channel_for_local_cid_and_handle(local_cid, handle); 4255 if (!channel) { 4256 log_error("credit: no channel for cid 0x%02x", local_cid); 4257 break; 4258 } 4259 channel->remote_sig_id = sig_id; 4260 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 4261 break; 4262 4263 case DISCONNECTION_RESPONSE: 4264 // check size 4265 if (len < 4u) return 0u; 4266 4267 // find channel 4268 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 4269 channel = l2cap_get_channel_for_local_cid_and_handle(local_cid, handle); 4270 if (!channel) break; 4271 if (channel->local_sig_id == sig_id) { 4272 if (channel->state == L2CAP_STATE_WAIT_DISCONNECT){ 4273 l2cap_finalize_channel_close(channel); 4274 } 4275 } 4276 break; 4277 #endif 4278 4279 default: 4280 // command unknown -> reject command 4281 return 0; 4282 } 4283 return 1; 4284 } 4285 #endif 4286 4287 #ifdef ENABLE_CLASSIC 4288 static void l2cap_acl_classic_handler_for_channel(l2cap_channel_t * l2cap_channel, uint8_t * packet, uint16_t size){ 4289 4290 // forward data only in OPEN state 4291 if (l2cap_channel->state != L2CAP_STATE_OPEN) return; 4292 4293 #ifdef ENABLE_L2CAP_CREDIT_BASED_CHANNELS 4294 if (l2cap_channel->channel_type == L2CAP_CHANNEL_TYPE_ENHANCED_DATA_CHANNEL){ 4295 l2cap_credit_based_handle_pdu(l2cap_channel, packet, size); 4296 return; 4297 } 4298 #endif 4299 4300 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 4301 if (l2cap_channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 4302 4303 int fcs_size = l2cap_channel->fcs_option ? 2 : 0; 4304 4305 // assert control + FCS fields are inside 4306 if (size < COMPLETE_L2CAP_HEADER+2+fcs_size) return; 4307 4308 if (l2cap_channel->fcs_option){ 4309 // verify FCS (required if one side requested it) 4310 uint16_t fcs_calculated = crc16_calc(&packet[4], size - (4+2)); 4311 uint16_t fcs_packet = little_endian_read_16(packet, size-2); 4312 4313 #ifdef L2CAP_ERTM_SIMULATE_FCS_ERROR_INTERVAL 4314 // simulate fcs error 4315 static int counter = 0; 4316 if (++counter == L2CAP_ERTM_SIMULATE_FCS_ERROR_INTERVAL) { 4317 log_info("Simulate fcs error"); 4318 fcs_calculated++; 4319 counter = 0; 4320 } 4321 #endif 4322 4323 if (fcs_calculated == fcs_packet){ 4324 log_info("Packet FCS 0x%04x verified", fcs_packet); 4325 } else { 4326 log_error("FCS mismatch! Packet 0x%04x, calculated 0x%04x", fcs_packet, fcs_calculated); 4327 // ERTM State Machine in Bluetooth Spec does not handle 'I-Frame with invalid FCS' 4328 return; 4329 } 4330 } 4331 4332 // switch on packet type 4333 uint16_t control = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 4334 uint8_t req_seq = (control >> 8) & 0x3f; 4335 int final = (control >> 7) & 0x01; 4336 if (control & 1){ 4337 // S-Frame 4338 int poll = (control >> 4) & 0x01; 4339 l2cap_supervisory_function_t s = (l2cap_supervisory_function_t) ((control >> 2) & 0x03); 4340 log_info("Control: 0x%04x => Supervisory function %u, ReqSeq %02u", control, (int) s, req_seq); 4341 l2cap_ertm_tx_packet_state_t * tx_state; 4342 switch (s){ 4343 case L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY: 4344 log_info("L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY"); 4345 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 4346 if (poll && final){ 4347 // S-frames shall not be transmitted with both the F-bit and the P-bit set to 1 at the same time. 4348 log_error("P=F=1 in S-Frame"); 4349 break; 4350 } 4351 if (poll){ 4352 // check if we did request selective retransmission before <==> we have stored SDU segments 4353 int i; 4354 int num_stored_out_of_order_packets = 0; 4355 for (i=0;i<l2cap_channel->num_rx_buffers;i++){ 4356 int index = l2cap_channel->rx_store_index + i; 4357 if (index >= l2cap_channel->num_rx_buffers){ 4358 index -= l2cap_channel->num_rx_buffers; 4359 } 4360 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 4361 if (!rx_state->valid) continue; 4362 num_stored_out_of_order_packets++; 4363 } 4364 if (num_stored_out_of_order_packets){ 4365 l2cap_channel->send_supervisor_frame_selective_reject = 1; 4366 } else { 4367 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 4368 } 4369 l2cap_channel->set_final_bit_after_packet_with_poll_bit_set = 1; 4370 } 4371 if (final){ 4372 // Stop-MonitorTimer 4373 l2cap_ertm_stop_monitor_timer(l2cap_channel); 4374 // If UnackedFrames > 0 then Start-RetransTimer 4375 if (l2cap_channel->unacked_frames){ 4376 l2cap_ertm_start_retransmission_timer(l2cap_channel); 4377 } 4378 // final bit set <- response to RR with poll bit set. All not acknowledged packets need to be retransmitted 4379 l2cap_ertm_retransmit_unacknowleded_frames(l2cap_channel); 4380 } 4381 break; 4382 case L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT: 4383 log_info("L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT"); 4384 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 4385 // restart transmittion from last unacknowledted packet (earlier packets already freed in l2cap_ertm_process_req_seq) 4386 l2cap_ertm_retransmit_unacknowleded_frames(l2cap_channel); 4387 break; 4388 case L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY: 4389 log_error("L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY"); 4390 break; 4391 case L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT: 4392 log_info("L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT"); 4393 if (poll){ 4394 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 4395 } 4396 // find requested i-frame 4397 tx_state = l2cap_ertm_get_tx_state(l2cap_channel, req_seq); 4398 if (tx_state){ 4399 log_info("Retransmission for tx_seq %u requested", req_seq); 4400 l2cap_channel->set_final_bit_after_packet_with_poll_bit_set = poll; 4401 tx_state->retransmission_requested = 1; 4402 l2cap_channel->srej_active = 1; 4403 } 4404 break; 4405 default: 4406 break; 4407 } 4408 } else { 4409 // I-Frame 4410 // get control 4411 l2cap_segmentation_and_reassembly_t sar = (l2cap_segmentation_and_reassembly_t) (control >> 14); 4412 uint8_t tx_seq = (control >> 1) & 0x3f; 4413 log_info("Control: 0x%04x => SAR %u, ReqSeq %02u, R?, TxSeq %02u", control, (int) sar, req_seq, tx_seq); 4414 log_info("SAR: pos %u", l2cap_channel->reassembly_pos); 4415 log_info("State: expected_tx_seq %02u, req_seq %02u", l2cap_channel->expected_tx_seq, l2cap_channel->req_seq); 4416 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 4417 if (final){ 4418 // final bit set <- response to RR with poll bit set. All not acknowledged packets need to be retransmitted 4419 l2cap_ertm_retransmit_unacknowleded_frames(l2cap_channel); 4420 } 4421 4422 // get SDU 4423 const uint8_t * payload_data = &packet[COMPLETE_L2CAP_HEADER+2]; 4424 uint16_t payload_len = size-(COMPLETE_L2CAP_HEADER+2+fcs_size); 4425 4426 // assert SDU size is smaller or equal to our buffers 4427 uint16_t max_payload_size = 0; 4428 switch (sar){ 4429 case L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU: 4430 case L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU: 4431 // SDU Length + MPS 4432 max_payload_size = l2cap_channel->local_mps + 2; 4433 break; 4434 case L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU: 4435 case L2CAP_SEGMENTATION_AND_REASSEMBLY_END_OF_L2CAP_SDU: 4436 max_payload_size = l2cap_channel->local_mps; 4437 break; 4438 default: 4439 btstack_assert(false); 4440 break; 4441 } 4442 if (payload_len > max_payload_size){ 4443 log_info("payload len %u > max payload %u -> drop packet", payload_len, max_payload_size); 4444 return; 4445 } 4446 4447 // check ordering 4448 if (l2cap_channel->expected_tx_seq == tx_seq){ 4449 log_info("Received expected frame with TxSeq == ExpectedTxSeq == %02u", tx_seq); 4450 l2cap_channel->expected_tx_seq = l2cap_next_ertm_seq_nr(l2cap_channel->expected_tx_seq); 4451 l2cap_channel->req_seq = l2cap_channel->expected_tx_seq; 4452 4453 // process SDU 4454 l2cap_ertm_handle_in_sequence_sdu(l2cap_channel, sar, payload_data, payload_len); 4455 4456 // process stored segments 4457 while (true){ 4458 int index = l2cap_channel->rx_store_index; 4459 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 4460 if (!rx_state->valid) break; 4461 4462 log_info("Processing stored frame with TxSeq == ExpectedTxSeq == %02u", l2cap_channel->expected_tx_seq); 4463 l2cap_channel->expected_tx_seq = l2cap_next_ertm_seq_nr(l2cap_channel->expected_tx_seq); 4464 l2cap_channel->req_seq = l2cap_channel->expected_tx_seq; 4465 4466 rx_state->valid = 0; 4467 l2cap_ertm_handle_in_sequence_sdu(l2cap_channel, rx_state->sar, &l2cap_channel->rx_packets_data[index], rx_state->len); 4468 4469 // update rx store index 4470 index++; 4471 if (index >= l2cap_channel->num_rx_buffers){ 4472 index = 0; 4473 } 4474 l2cap_channel->rx_store_index = index; 4475 } 4476 4477 // 4478 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 4479 4480 } else { 4481 int delta = (tx_seq - l2cap_channel->expected_tx_seq) & 0x3f; 4482 if (delta < 2){ 4483 // store segment 4484 l2cap_ertm_handle_out_of_sequence_sdu(l2cap_channel, sar, delta, payload_data, payload_len); 4485 4486 log_info("Received unexpected frame TxSeq %u but expected %u -> send S-SREJ", tx_seq, l2cap_channel->expected_tx_seq); 4487 l2cap_channel->send_supervisor_frame_selective_reject = 1; 4488 } else { 4489 log_info("Received unexpected frame TxSeq %u but expected %u -> send S-REJ", tx_seq, l2cap_channel->expected_tx_seq); 4490 l2cap_channel->send_supervisor_frame_reject = 1; 4491 } 4492 } 4493 } 4494 return; 4495 } 4496 #endif 4497 4498 // check size 4499 uint16_t payload_size = size - COMPLETE_L2CAP_HEADER; 4500 if (l2cap_channel->local_mtu < payload_size) return; 4501 4502 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], payload_size); 4503 } 4504 #endif 4505 4506 static void l2cap_acl_classic_handler(hci_con_handle_t handle, uint8_t *packet, uint16_t size){ 4507 #ifdef ENABLE_CLASSIC 4508 l2cap_channel_t * l2cap_channel; 4509 l2cap_fixed_channel_t * l2cap_fixed_channel; 4510 4511 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 4512 uint8_t broadcast_flag = READ_ACL_FLAGS(packet) >> 2; 4513 switch (channel_id) { 4514 4515 case L2CAP_CID_SIGNALING: { 4516 if (broadcast_flag != 0) break; 4517 uint32_t command_offset = 8; 4518 while ((command_offset + L2CAP_SIGNALING_COMMAND_DATA_OFFSET) < size) { 4519 // assert signaling command is fully inside packet 4520 uint16_t data_len = little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 4521 uint32_t next_command_offset = command_offset + L2CAP_SIGNALING_COMMAND_DATA_OFFSET + data_len; 4522 if (next_command_offset > size){ 4523 log_error("l2cap signaling command len invalid -> drop"); 4524 break; 4525 } 4526 // handle signaling command 4527 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 4528 // go to next command 4529 command_offset = next_command_offset; 4530 } 4531 break; 4532 } 4533 4534 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 4535 if (broadcast_flag == 0) break; 4536 l2cap_fixed_channel = l2cap_fixed_channel_for_channel_id(L2CAP_CID_CONNECTIONLESS_CHANNEL); 4537 if (!l2cap_fixed_channel) break; 4538 if (!l2cap_fixed_channel->packet_handler) break; 4539 (*l2cap_fixed_channel->packet_handler)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 4540 break; 4541 4542 #ifdef ENABLE_BLE 4543 case L2CAP_CID_BR_EDR_SECURITY_MANAGER: 4544 l2cap_fixed_channel = l2cap_fixed_channel_for_channel_id(L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 4545 if ((l2cap_fixed_channel == NULL) || (l2cap_fixed_channel->packet_handler == NULL)){ 4546 // Pairing Failed 4547 l2cap_register_signaling_response(handle, (uint8_t) SM_PAIRING_FAILED, 0, L2CAP_CID_BR_EDR_SECURITY_MANAGER, SM_REASON_PAIRING_NOT_SUPPORTED); 4548 } else { 4549 (*l2cap_fixed_channel->packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 4550 } 4551 break; 4552 #endif 4553 4554 default: 4555 if (broadcast_flag != 0) break; 4556 // Find channel for this channel_id and connection handle 4557 l2cap_channel = l2cap_get_channel_for_local_cid_and_handle(channel_id, handle); 4558 if (l2cap_channel != NULL){ 4559 l2cap_acl_classic_handler_for_channel(l2cap_channel, packet, size); 4560 } 4561 break; 4562 } 4563 #else 4564 UNUSED(handle); // ok: no code 4565 UNUSED(packet); // ok: no code 4566 UNUSED(size); // ok: no code 4567 #endif 4568 } 4569 4570 static void l2cap_acl_le_handler(hci_con_handle_t handle, uint8_t *packet, uint16_t size){ 4571 #ifdef ENABLE_BLE 4572 4573 l2cap_fixed_channel_t * l2cap_fixed_channel; 4574 4575 #ifdef ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE 4576 l2cap_channel_t * l2cap_channel; 4577 #endif 4578 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 4579 switch (channel_id) { 4580 4581 case L2CAP_CID_SIGNALING_LE: { 4582 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 4583 uint16_t len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER + 2); 4584 if ((COMPLETE_L2CAP_HEADER + 4u + len) > size) break; 4585 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 4586 if (!valid){ 4587 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 4588 } 4589 break; 4590 } 4591 4592 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 4593 l2cap_fixed_channel = l2cap_fixed_channel_for_channel_id(L2CAP_CID_ATTRIBUTE_PROTOCOL); 4594 if (!l2cap_fixed_channel) break; 4595 if (!l2cap_fixed_channel->packet_handler) break; 4596 (*l2cap_fixed_channel->packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 4597 break; 4598 4599 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 4600 l2cap_fixed_channel = l2cap_fixed_channel_for_channel_id(L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 4601 if ((l2cap_fixed_channel == NULL) || (l2cap_fixed_channel->packet_handler == NULL)){ 4602 // Pairing Failed 4603 l2cap_register_signaling_response(handle, (uint8_t) SM_PAIRING_FAILED, 0, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, SM_REASON_PAIRING_NOT_SUPPORTED); 4604 } else { 4605 (*l2cap_fixed_channel->packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 4606 } 4607 break; 4608 4609 default: 4610 4611 #ifdef ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE 4612 l2cap_channel = l2cap_get_channel_for_local_cid_and_handle(channel_id, handle); 4613 if (l2cap_channel != NULL) { 4614 l2cap_credit_based_handle_pdu(l2cap_channel, packet, size); 4615 } 4616 #endif 4617 break; 4618 } 4619 #else 4620 UNUSED(handle); // ok: no code 4621 UNUSED(packet); // ok: no code 4622 UNUSED(size); // ok: no code 4623 #endif 4624 } 4625 4626 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 4627 UNUSED(packet_type); // ok: registered with hci_register_acl_packet_handler 4628 UNUSED(channel); // ok: there is no channel 4629 4630 // Assert full L2CAP header present 4631 if (size < COMPLETE_L2CAP_HEADER) return; 4632 4633 // Dispatch to Classic or LE handler (SCO packets are not dispatched to L2CAP) 4634 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 4635 hci_connection_t *conn = hci_connection_for_handle(handle); 4636 if (!conn) return; 4637 if (conn->address_type == BD_ADDR_TYPE_ACL){ 4638 l2cap_acl_classic_handler(handle, packet, size); 4639 } else { 4640 l2cap_acl_le_handler(handle, packet, size); 4641 } 4642 4643 l2cap_run(); 4644 } 4645 4646 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 4647 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 4648 l2cap_fixed_channel_t * channel = l2cap_fixed_channel_for_channel_id(channel_id); 4649 if (!channel) return; 4650 channel->packet_handler = packet_handler; 4651 } 4652 4653 #ifdef L2CAP_USES_CHANNELS 4654 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 4655 void l2cap_finalize_channel_close(l2cap_channel_t * channel){ 4656 channel->state = L2CAP_STATE_CLOSED; 4657 l2cap_handle_channel_closed(channel); 4658 // discard channel 4659 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 4660 l2cap_free_channel_entry(channel); 4661 } 4662 #endif 4663 4664 #ifdef ENABLE_CLASSIC 4665 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 4666 return l2cap_get_service_internal(&l2cap_services, psm); 4667 } 4668 4669 static void l2cap_update_minimal_security_level(void){ 4670 // update minimal service security level 4671 gap_security_level_t minimal_level = LEVEL_1; 4672 btstack_linked_list_iterator_t it; 4673 btstack_linked_list_iterator_init(&it, &l2cap_services); 4674 while (btstack_linked_list_iterator_has_next(&it)){ 4675 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 4676 if (service->required_security_level > minimal_level){ 4677 minimal_level = service->required_security_level; 4678 }; 4679 } 4680 gap_set_minimal_service_security_level(minimal_level); 4681 } 4682 4683 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 4684 4685 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 4686 4687 // check for alread registered psm 4688 l2cap_service_t *service = l2cap_get_service(psm); 4689 if (service) { 4690 log_error("register: PSM %u already registered", psm); 4691 return L2CAP_SERVICE_ALREADY_REGISTERED; 4692 } 4693 4694 // alloc structure 4695 service = btstack_memory_l2cap_service_get(); 4696 if (!service) { 4697 log_error("register: no memory for l2cap_service_t"); 4698 return BTSTACK_MEMORY_ALLOC_FAILED; 4699 } 4700 4701 // fill in 4702 service->psm = psm; 4703 service->mtu = mtu; 4704 service->packet_handler = service_packet_handler; 4705 service->required_security_level = security_level; 4706 4707 // add to services list 4708 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 4709 4710 l2cap_update_minimal_security_level(); 4711 4712 #ifndef ENABLE_EXPLICIT_CONNECTABLE_MODE_CONTROL 4713 // enable page scan 4714 gap_connectable_control(1); 4715 #endif 4716 4717 4718 return ERROR_CODE_SUCCESS; 4719 } 4720 4721 uint8_t l2cap_unregister_service(uint16_t psm){ 4722 4723 log_info("unregister psm 0x%x", psm); 4724 4725 l2cap_service_t *service = l2cap_get_service(psm); 4726 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 4727 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 4728 btstack_memory_l2cap_service_free(service); 4729 4730 l2cap_update_minimal_security_level(); 4731 4732 #ifndef ENABLE_EXPLICIT_CONNECTABLE_MODE_CONTROL 4733 // disable page scan when no services registered 4734 if (btstack_linked_list_empty(&l2cap_services)) { 4735 gap_connectable_control(0); 4736 } 4737 #endif 4738 4739 return ERROR_CODE_SUCCESS; 4740 } 4741 #endif 4742 4743 4744 #ifdef ENABLE_L2CAP_CREDIT_BASED_CHANNELS 4745 4746 static void l2cap_credit_based_send_pdu(l2cap_channel_t *channel) { 4747 btstack_assert(channel != NULL); 4748 btstack_assert(channel->send_sdu_buffer != NULL); 4749 btstack_assert(channel->credits_outgoing > 0); 4750 4751 // send part of SDU 4752 hci_reserve_packet_buffer(); 4753 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 4754 uint8_t *l2cap_payload = acl_buffer + 8; 4755 uint16_t pos = 0; 4756 if (!channel->send_sdu_pos) { 4757 // store SDU len 4758 channel->send_sdu_pos += 2u; 4759 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 4760 pos += 2u; 4761 } 4762 uint16_t payload_size = btstack_min(channel->send_sdu_len + 2u - channel->send_sdu_pos, channel->remote_mps - pos); 4763 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, 4764 channel->credits_outgoing); 4765 (void) memcpy(&l2cap_payload[pos], 4766 &channel->send_sdu_buffer[channel->send_sdu_pos - 2u], 4767 payload_size); // -2 for virtual SDU len 4768 pos += payload_size; 4769 channel->send_sdu_pos += payload_size; 4770 l2cap_setup_header(acl_buffer, channel->con_handle, 0, channel->remote_cid, pos); 4771 4772 channel->credits_outgoing--; 4773 4774 // update state (mark SDU as done) before calling hci_send_acl_packet_buffer (trigger l2cap_le_send_pdu again) 4775 bool done = channel->send_sdu_pos >= (channel->send_sdu_len + 2u); 4776 if (done) { 4777 channel->send_sdu_buffer = NULL; 4778 } 4779 4780 hci_send_acl_packet_buffer(8u + pos); 4781 4782 if (done) { 4783 // send done event 4784 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_PACKET_SENT); 4785 // inform about can send now 4786 l2cap_le_notify_channel_can_send(channel); 4787 } 4788 } 4789 4790 static uint8_t l2cap_credit_based_send_data(uint16_t local_cid, const uint8_t * data, uint16_t size){ 4791 4792 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 4793 if (!channel) { 4794 log_error("l2cap send, no channel for cid 0x%02x", local_cid); 4795 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 4796 } 4797 4798 if (size > channel->remote_mtu){ 4799 log_error("l2cap send, cid 0x%02x, data length exceeds remote MTU.", local_cid); 4800 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 4801 } 4802 4803 if (channel->send_sdu_buffer){ 4804 log_info("l2cap send, cid 0x%02x, cannot send", local_cid); 4805 return BTSTACK_ACL_BUFFERS_FULL; 4806 } 4807 4808 channel->send_sdu_buffer = data; 4809 channel->send_sdu_len = size; 4810 channel->send_sdu_pos = 0; 4811 4812 l2cap_notify_channel_can_send(); 4813 return ERROR_CODE_SUCCESS; 4814 } 4815 4816 static uint8_t l2cap_credit_based_provide_credits(uint16_t local_cid, uint16_t credits){ 4817 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 4818 if (!channel) { 4819 log_error("le credits no channel for cid 0x%02x", local_cid); 4820 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 4821 } 4822 4823 // check state 4824 if (channel->state != L2CAP_STATE_OPEN){ 4825 log_error("le credits but channel 0x%02x not open yet", local_cid); 4826 } 4827 4828 // ignore if set to automatic credits 4829 if (channel->automatic_credits) return ERROR_CODE_SUCCESS; 4830 4831 // assert incoming credits + credits <= 0xffff 4832 uint32_t total_credits = channel->credits_incoming; 4833 total_credits += channel->new_credits_incoming; 4834 total_credits += credits; 4835 if (total_credits > 0xffffu){ 4836 log_error("le credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 4837 channel->new_credits_incoming, credits); 4838 } 4839 4840 // set credits_granted 4841 channel->new_credits_incoming += credits; 4842 4843 // go 4844 l2cap_run(); 4845 return ERROR_CODE_SUCCESS; 4846 } 4847 4848 static void l2cap_credit_based_send_credits(l2cap_channel_t *channel) { 4849 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 4850 channel->local_sig_id = l2cap_next_sig_id(); 4851 uint16_t new_credits = channel->new_credits_incoming; 4852 channel->new_credits_incoming = 0; 4853 channel->credits_incoming += new_credits; 4854 uint16_t signaling_cid = channel->address_type == BD_ADDR_TYPE_ACL ? L2CAP_CID_SIGNALING : L2CAP_CID_SIGNALING_LE; 4855 l2cap_send_general_signaling_packet(channel->con_handle, signaling_cid, L2CAP_FLOW_CONTROL_CREDIT_INDICATION, channel->local_sig_id, channel->local_cid, new_credits); 4856 } 4857 4858 // @return valid 4859 static bool l2cap_credit_based_handle_credit_indication(hci_con_handle_t handle, const uint8_t * command, uint16_t len){ 4860 // check size 4861 if (len < 4u) return false; 4862 4863 // find channel 4864 uint16_t remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 4865 l2cap_channel_t * channel = l2cap_get_channel_for_remote_handle_and_cid(handle, remote_cid); 4866 if (!channel) { 4867 log_error("credit: no channel for handle 0x%04x/cid 0x%02x", handle, remote_cid); 4868 return true; 4869 } 4870 uint16_t new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 4871 uint16_t credits_before = channel->credits_outgoing; 4872 channel->credits_outgoing += new_credits; 4873 // check for credit overrun 4874 if (credits_before > channel->credits_outgoing) { 4875 log_error("credit: new credits caused overrrun for cid 0x%02x, disconnecting", channel->local_cid); 4876 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 4877 return true; 4878 } 4879 log_info("credit: %u credits for 0x%02x, now %u", new_credits, channel->local_cid, channel->credits_outgoing); 4880 l2cap_call_notify_channel_in_run = true; 4881 return true; 4882 } 4883 4884 static void l2cap_credit_based_handle_pdu(l2cap_channel_t * l2cap_channel, const uint8_t * packet, uint16_t size){ 4885 // ignore empty packets 4886 if (size == COMPLETE_L2CAP_HEADER) return; 4887 4888 // credit counting 4889 if (l2cap_channel->credits_incoming == 0u){ 4890 log_info("Data Channel packet received but no incoming credits"); 4891 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 4892 return; 4893 } 4894 l2cap_channel->credits_incoming--; 4895 4896 // automatic credits 4897 if ((l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK) && l2cap_channel->automatic_credits){ 4898 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 4899 } 4900 4901 // first fragment 4902 uint16_t pos = 0; 4903 if (!l2cap_channel->receive_sdu_len){ 4904 if (size < (COMPLETE_L2CAP_HEADER + 2)) return; 4905 uint16_t sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 4906 if(sdu_len > l2cap_channel->local_mtu) return; // SDU would be larger than our buffer 4907 l2cap_channel->receive_sdu_len = sdu_len; 4908 l2cap_channel->receive_sdu_pos = 0; 4909 pos += 2u; 4910 size -= 2u; 4911 } 4912 uint16_t fragment_size = size-COMPLETE_L2CAP_HEADER; 4913 uint16_t remaining_space = l2cap_channel->local_mtu - l2cap_channel->receive_sdu_pos; 4914 if (fragment_size > remaining_space) return; // SDU would cause buffer overrun 4915 (void)memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], 4916 &packet[COMPLETE_L2CAP_HEADER + pos], 4917 fragment_size); 4918 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 4919 // done? 4920 log_debug("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 4921 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 4922 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 4923 l2cap_channel->receive_sdu_len = 0; 4924 } 4925 } 4926 4927 static uint8_t l2cap_credit_based_disconnect(uint16_t local_cid){ 4928 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 4929 if (!channel) { 4930 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 4931 } 4932 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 4933 l2cap_run(); 4934 return ERROR_CODE_SUCCESS; 4935 } 4936 #endif 4937 4938 #ifdef ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE 4939 4940 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 4941 if (!channel->waiting_for_can_send_now) return; 4942 if (channel->send_sdu_buffer) return; 4943 channel->waiting_for_can_send_now = 0; 4944 log_debug("le can send now, local_cid 0x%x", channel->local_cid); 4945 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 4946 } 4947 4948 // 1BH2222 4949 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 4950 log_info("le incoming addr_type %u, addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x, remote_mtu %u", 4951 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 4952 uint8_t event[19]; 4953 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 4954 event[1] = sizeof(event) - 2u; 4955 event[2] = channel->address_type; 4956 reverse_bd_addr(channel->address, &event[3]); 4957 little_endian_store_16(event, 9, channel->con_handle); 4958 little_endian_store_16(event, 11, channel->psm); 4959 little_endian_store_16(event, 13, channel->local_cid); 4960 little_endian_store_16(event, 15, channel->remote_cid); 4961 little_endian_store_16(event, 17, channel->remote_mtu); 4962 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 4963 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 4964 } 4965 // 11BH22222 4966 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 4967 log_info("opened le channel status 0x%x addr_type %u addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x local_mtu %u, remote_mtu %u", 4968 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 4969 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 4970 uint8_t event[23]; 4971 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 4972 event[1] = sizeof(event) - 2u; 4973 event[2] = status; 4974 event[3] = channel->address_type; 4975 reverse_bd_addr(channel->address, &event[4]); 4976 little_endian_store_16(event, 10, channel->con_handle); 4977 event[12] = (channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING) ? 1 : 0; 4978 little_endian_store_16(event, 13, channel->psm); 4979 little_endian_store_16(event, 15, channel->local_cid); 4980 little_endian_store_16(event, 17, channel->remote_cid); 4981 little_endian_store_16(event, 19, channel->local_mtu); 4982 little_endian_store_16(event, 21, channel->remote_mtu); 4983 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 4984 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 4985 } 4986 // 2 4987 static void l2cap_emit_le_channel_closed(l2cap_channel_t * channel){ 4988 log_info("closed local_cid 0x%x", channel->local_cid); 4989 uint8_t event[4]; 4990 event[0] = L2CAP_EVENT_LE_CHANNEL_CLOSED; 4991 event[1] = sizeof(event) - 2u; 4992 little_endian_store_16(event, 2, channel->local_cid); 4993 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 4994 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 4995 } 4996 4997 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 4998 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 4999 channel->state = L2CAP_STATE_CLOSED; 5000 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 5001 // discard channel 5002 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 5003 l2cap_free_channel_entry(channel); 5004 } 5005 5006 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 5007 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 5008 } 5009 5010 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 5011 5012 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 5013 5014 // check for alread registered psm 5015 l2cap_service_t *service = l2cap_le_get_service(psm); 5016 if (service) { 5017 return L2CAP_SERVICE_ALREADY_REGISTERED; 5018 } 5019 5020 // alloc structure 5021 service = btstack_memory_l2cap_service_get(); 5022 if (!service) { 5023 log_error("register: no memory for l2cap_service_t"); 5024 return BTSTACK_MEMORY_ALLOC_FAILED; 5025 } 5026 5027 // fill in 5028 service->psm = psm; 5029 service->mtu = 0; 5030 service->packet_handler = packet_handler; 5031 service->required_security_level = security_level; 5032 5033 // add to services list 5034 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 5035 5036 // done 5037 return ERROR_CODE_SUCCESS; 5038 } 5039 5040 uint8_t l2cap_le_unregister_service(uint16_t psm) { 5041 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 5042 l2cap_service_t *service = l2cap_le_get_service(psm); 5043 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 5044 5045 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 5046 btstack_memory_l2cap_service_free(service); 5047 return ERROR_CODE_SUCCESS; 5048 } 5049 5050 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 5051 // get channel 5052 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 5053 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 5054 5055 // validate state 5056 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 5057 return ERROR_CODE_COMMAND_DISALLOWED; 5058 } 5059 5060 // set state accept connection 5061 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 5062 channel->receive_sdu_buffer = receive_sdu_buffer; 5063 channel->local_mtu = mtu; 5064 channel->new_credits_incoming = initial_credits; 5065 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 5066 5067 // go 5068 l2cap_run(); 5069 return ERROR_CODE_SUCCESS; 5070 } 5071 5072 /** 5073 * @brief Deny incoming LE Data Channel connection due to resource constraints 5074 * @param local_cid L2CAP LE Data Channel Identifier 5075 */ 5076 5077 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 5078 // get channel 5079 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 5080 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 5081 5082 // validate state 5083 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 5084 return ERROR_CODE_COMMAND_DISALLOWED; 5085 } 5086 5087 // set state decline connection 5088 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 5089 channel->reason = 0x04; // no resources available 5090 l2cap_run(); 5091 return ERROR_CODE_SUCCESS; 5092 } 5093 5094 static gap_security_level_t l2cap_le_security_level_for_connection(hci_con_handle_t con_handle){ 5095 uint8_t encryption_key_size = gap_encryption_key_size(con_handle); 5096 if (encryption_key_size == 0) return LEVEL_0; 5097 5098 uint8_t authenticated = gap_authenticated(con_handle); 5099 if (!authenticated) return LEVEL_2; 5100 5101 return encryption_key_size == 16 ? LEVEL_4 : LEVEL_3; 5102 } 5103 5104 // used to handle pairing complete after triggering to increase 5105 static void l2cap_sm_packet_handler(uint8_t packet_type, uint16_t channel_nr, uint8_t *packet, uint16_t size) { 5106 UNUSED(channel_nr); 5107 UNUSED(size); 5108 UNUSED(packet_type); 5109 btstack_assert(packet_type == HCI_EVENT_PACKET); 5110 if (hci_event_packet_get_type(packet) != SM_EVENT_PAIRING_COMPLETE) return; 5111 hci_con_handle_t con_handle = sm_event_pairing_complete_get_handle(packet); 5112 btstack_linked_list_iterator_t it; 5113 btstack_linked_list_iterator_init(&it, &l2cap_channels); 5114 while (btstack_linked_list_iterator_has_next(&it)) { 5115 l2cap_channel_t *channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 5116 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 5117 if (channel->con_handle != con_handle) continue; 5118 if (channel->state != L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE) continue; 5119 5120 // found channel, check security level 5121 if (l2cap_le_security_level_for_connection(con_handle) < channel->required_security_level){ 5122 // pairing failed or wasn't good enough, inform user 5123 l2cap_emit_le_channel_opened(channel, ERROR_CODE_INSUFFICIENT_SECURITY); 5124 // discard channel 5125 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 5126 l2cap_free_channel_entry(channel); 5127 } else { 5128 // send conn request now 5129 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 5130 l2cap_run(); 5131 } 5132 } 5133 } 5134 5135 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 5136 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 5137 uint16_t * out_local_cid) { 5138 5139 static btstack_packet_callback_registration_t sm_event_callback_registration; 5140 static bool sm_callback_registered = false; 5141 5142 log_info("create, handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 5143 5144 hci_connection_t * connection = hci_connection_for_handle(con_handle); 5145 if (!connection) { 5146 log_error("no hci_connection for handle 0x%04x", con_handle); 5147 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 5148 } 5149 5150 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, L2CAP_CHANNEL_TYPE_LE_DATA_CHANNEL, connection->address, connection->address_type, psm, mtu, security_level); 5151 if (!channel) { 5152 return BTSTACK_MEMORY_ALLOC_FAILED; 5153 } 5154 log_info("created %p", channel); 5155 5156 // store local_cid 5157 if (out_local_cid){ 5158 *out_local_cid = channel->local_cid; 5159 } 5160 5161 // setup channel entry 5162 channel->con_handle = con_handle; 5163 channel->receive_sdu_buffer = receive_sdu_buffer; 5164 channel->new_credits_incoming = initial_credits; 5165 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 5166 5167 // add to connections list 5168 btstack_linked_list_add_tail(&l2cap_channels, (btstack_linked_item_t *) channel); 5169 5170 // check security level 5171 if (l2cap_le_security_level_for_connection(con_handle) < channel->required_security_level){ 5172 if (!sm_callback_registered){ 5173 sm_callback_registered = true; 5174 // lazy registration for SM events 5175 sm_event_callback_registration.callback = &l2cap_sm_packet_handler; 5176 sm_add_event_handler(&sm_event_callback_registration); 5177 } 5178 5179 // start pairing 5180 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 5181 sm_request_pairing(con_handle); 5182 } else { 5183 // send conn request right away 5184 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 5185 l2cap_run(); 5186 } 5187 5188 return ERROR_CODE_SUCCESS; 5189 } 5190 5191 /** 5192 * @brief Provide credtis for LE Data Channel 5193 * @param local_cid L2CAP LE Data Channel Identifier 5194 * @param credits Number additional credits for peer 5195 */ 5196 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 5197 return l2cap_credit_based_provide_credits(local_cid, credits); 5198 } 5199 5200 /** 5201 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 5202 * @param local_cid L2CAP LE Data Channel Identifier 5203 */ 5204 bool l2cap_le_can_send_now(uint16_t local_cid){ 5205 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 5206 if (!channel) { 5207 log_error("le can send now, no channel for cid 0x%02x", local_cid); 5208 return false; 5209 } 5210 5211 // check state 5212 if (channel->state != L2CAP_STATE_OPEN) return false; 5213 5214 // check queue 5215 if (channel->send_sdu_buffer) return false; 5216 5217 // fine, go ahead 5218 return true; 5219 } 5220 5221 /** 5222 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 5223 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 5224 * so packet handler should be ready to handle it 5225 * @param local_cid L2CAP LE Data Channel Identifier 5226 */ 5227 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 5228 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 5229 if (!channel) { 5230 log_error("can send now, no channel for cid 0x%02x", local_cid); 5231 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 5232 } 5233 channel->waiting_for_can_send_now = 1; 5234 l2cap_le_notify_channel_can_send(channel); 5235 return ERROR_CODE_SUCCESS; 5236 } 5237 5238 /** 5239 * @brief Send data via LE Data Channel 5240 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 5241 * @param local_cid L2CAP LE Data Channel Identifier 5242 * @param data data to send 5243 * @param size data size 5244 */ 5245 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t size){ 5246 return l2cap_credit_based_send_data(local_cid, data, size); 5247 } 5248 5249 5250 /** 5251 * @brief Disconnect from LE Data Channel 5252 * @param local_cid L2CAP LE Data Channel Identifier 5253 */ 5254 uint8_t l2cap_le_disconnect(uint16_t local_cid){ 5255 return l2cap_credit_based_disconnect(local_cid); 5256 } 5257 #endif 5258 5259 #ifdef ENABLE_L2CAP_ENHANCED_DATA_CHANNELS 5260 5261 uint8_t l2cap_enhanced_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t min_remote_mtu, gap_security_level_t security_level){ 5262 5263 // check for already registered psm 5264 l2cap_service_t *service = l2cap_le_get_service(psm); 5265 if (service) { 5266 return L2CAP_SERVICE_ALREADY_REGISTERED; 5267 } 5268 5269 // alloc structure 5270 service = btstack_memory_l2cap_service_get(); 5271 if (!service) { 5272 log_error("register: no memory for l2cap_service_t"); 5273 return BTSTACK_MEMORY_ALLOC_FAILED; 5274 } 5275 5276 // fill in 5277 service->psm = psm; 5278 service->mtu = min_remote_mtu; 5279 service->packet_handler = packet_handler; 5280 service->required_security_level = security_level; 5281 5282 // add to services list 5283 btstack_linked_list_add(&l2cap_enhanced_services, (btstack_linked_item_t *) service); 5284 5285 // done 5286 return ERROR_CODE_SUCCESS; 5287 } 5288 5289 uint8_t l2cap_enhanced_unregister_service(uint16_t psm) { 5290 l2cap_service_t *service = l2cap_le_get_service(psm); 5291 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 5292 5293 btstack_linked_list_remove(&l2cap_enhanced_services, (btstack_linked_item_t *) service); 5294 btstack_memory_l2cap_service_free(service); 5295 return ERROR_CODE_SUCCESS; 5296 } 5297 5298 void l2cap_enhanced_mps_set_min(uint16_t mps_min){ 5299 l2cap_enhanced_mps_min = mps_min; 5300 } 5301 5302 void l2cap_enhanced_mps_set_max(uint16_t mps_max){ 5303 l2cap_enhanced_mps_max = mps_max; 5304 } 5305 5306 uint8_t l2cap_enhanced_create_channels(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 5307 gap_security_level_t security_level, 5308 uint16_t psm, uint8_t num_channels, uint16_t initial_credits, uint16_t mtu, 5309 uint8_t ** receive_sdu_buffers, uint16_t * out_local_cid){ 5310 5311 log_info("create enhanced, handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 5312 5313 hci_connection_t * connection = hci_connection_for_handle(con_handle); 5314 if (!connection) { 5315 log_error("no hci_connection for handle 0x%04x", con_handle); 5316 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 5317 } 5318 5319 // setup all channels 5320 btstack_linked_list_t channels = NULL; 5321 uint8_t status = l2cap_enhanced_setup_channels(&channels, packet_handler, num_channels, connection, psm, mtu, security_level); 5322 5323 // add to connections list and set state + local_sig_id 5324 l2cap_channel_t * channel; 5325 uint8_t i = 0; 5326 uint8_t local_sig_id = l2cap_next_sig_id(); 5327 while (true) { 5328 channel = (l2cap_channel_t *) btstack_linked_list_pop(&channels); 5329 if (channel == NULL) break; 5330 channel->state = L2CAP_STATE_WILL_SEND_ENHANCED_CONNECTION_REQUEST; 5331 channel->local_sig_id = local_sig_id; 5332 channel->cid_index = i; 5333 channel->num_cids = num_channels; 5334 channel->credits_incoming = initial_credits; 5335 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 5336 channel->receive_sdu_buffer = receive_sdu_buffers[i]; 5337 // store local_cid 5338 if (out_local_cid){ 5339 out_local_cid[i] = channel->local_cid; 5340 } 5341 btstack_linked_list_add_tail(&l2cap_channels, (btstack_linked_item_t *) channel); 5342 i++; 5343 } 5344 5345 #if 0 5346 // check security level 5347 if (l2cap_le_security_level_for_connection(con_handle) < channel->required_security_level){ 5348 if (!sm_callback_registered){ 5349 sm_callback_registered = true; 5350 // lazy registration for SM events 5351 sm_event_callback_registration.callback = &l2cap_sm_packet_handler; 5352 sm_add_event_handler(&sm_event_callback_registration); 5353 } 5354 5355 // start pairing 5356 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 5357 sm_request_pairing(con_handle); 5358 } else { 5359 // send conn request right away 5360 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 5361 l2cap_run(); 5362 } 5363 #endif 5364 5365 l2cap_run(); 5366 5367 return status; 5368 } 5369 5370 uint8_t l2cap_enhanced_accept_data_channels(uint16_t local_cid, uint8_t num_channels, uint16_t initial_credits, 5371 uint16_t receive_buffer_size, uint8_t ** receive_buffers, uint16_t * out_local_cids){ 5372 5373 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 5374 if (!channel) { 5375 5376 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 5377 } 5378 // 5379 hci_con_handle_t con_handle = channel->con_handle; 5380 uint8_t local_sig_id = channel->local_sig_id; 5381 uint8_t channel_index = 0; 5382 btstack_linked_list_iterator_t it; 5383 btstack_linked_list_iterator_init(&it, &l2cap_channels); 5384 while (btstack_linked_list_iterator_has_next(&it)) { 5385 channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 5386 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 5387 if (channel->con_handle != con_handle) continue; 5388 if (channel->local_sig_id != local_sig_id) continue; 5389 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT) continue; 5390 5391 if (channel_index < num_channels){ 5392 // assign buffer and cid 5393 out_local_cids[channel_index] = channel->local_cid; 5394 channel->receive_sdu_buffer = receive_buffers[channel_index]; 5395 channel->local_mtu = receive_buffer_size; 5396 channel->credits_incoming = initial_credits; 5397 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 5398 channel_index++; 5399 } else { 5400 // clear local cid for response packet 5401 channel->local_cid = 0; 5402 // Some connections refused – insufficient resources available 5403 channel->reason = 0x004; 5404 } 5405 // update state 5406 channel->state = L2CAP_STATE_WILL_SEND_ENHANCED_CONNECTION_RESPONSE; 5407 } 5408 l2cap_run(); 5409 return ERROR_CODE_SUCCESS; 5410 } 5411 5412 5413 5414 5415 5416 5417 uint8_t l2cap_enhanced_decline_data_channels(uint16_t local_cid, uint16_t result){ 5418 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 5419 if (!channel) { 5420 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 5421 } 5422 // 5423 hci_con_handle_t con_handle = channel->con_handle; 5424 uint8_t local_sig_id = channel->local_sig_id; 5425 btstack_linked_list_iterator_t it; 5426 btstack_linked_list_iterator_init(&it, &l2cap_channels); 5427 while (btstack_linked_list_iterator_has_next(&it)) { 5428 channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 5429 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 5430 if (channel->con_handle != con_handle) continue; 5431 if (channel->local_sig_id != local_sig_id) continue; 5432 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT) continue; 5433 5434 // prepare response 5435 channel->local_cid = 0; 5436 channel->reason = result; 5437 channel->state = L2CAP_STATE_WILL_SEND_ENHANCED_CONNECTION_RESPONSE; 5438 } 5439 l2cap_run(); 5440 return ERROR_CODE_SUCCESS; 5441 } 5442 5443 uint8_t l2cap_enhanced_data_channel_request_can_send_now_event(uint16_t local_cid){ 5444 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 5445 if (!channel) { 5446 log_error("can send now, no channel for cid 0x%02x", local_cid); 5447 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 5448 } 5449 channel->waiting_for_can_send_now = 1; 5450 l2cap_le_notify_channel_can_send(channel); 5451 return ERROR_CODE_SUCCESS; 5452 } 5453 5454 uint8_t l2cap_enhanced_reconfigure(uint8_t num_cids, uint16_t * local_cids, int16_t receive_buffer_size, uint8_t ** receive_buffers){ 5455 btstack_assert(receive_buffers != NULL); 5456 btstack_assert(local_cids != NULL); 5457 5458 if (num_cids > L2CAP_ENHANCED_DATA_CHANNEL_MAX_CID_ARRAY_SIZE){ 5459 return ERROR_CODE_UNACCEPTABLE_CONNECTION_PARAMETERS; 5460 } 5461 5462 // check if all cids exist and have the same con handle 5463 uint8_t i; 5464 hci_con_handle_t con_handle = HCI_CON_HANDLE_INVALID; 5465 for (i = 0 ; i < num_cids ; i++){ 5466 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cids[i]); 5467 if (!channel) { 5468 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 5469 } 5470 if (channel->state != L2CAP_STATE_OPEN){ 5471 return ERROR_CODE_COMMAND_DISALLOWED; 5472 } 5473 if (con_handle == HCI_CON_HANDLE_INVALID){ 5474 con_handle = channel->con_handle; 5475 } else if (con_handle != channel->con_handle){ 5476 return ERROR_CODE_UNACCEPTABLE_CONNECTION_PARAMETERS; 5477 } 5478 } 5479 // set renegotiation data and state 5480 uint8_t sig_id = l2cap_next_sig_id(); 5481 for (i = 0 ; i < num_cids ; i++){ 5482 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cids[i]); 5483 channel->cid_index = i; 5484 channel->num_cids = num_cids; 5485 channel->local_sig_id = sig_id; 5486 channel->renegotiate_mtu = receive_buffer_size; 5487 channel->renegotiate_sdu_buffer = receive_buffers[i]; 5488 channel->state = L2CAP_STATE_WILL_SEND_EHNANCED_RENEGOTIATION_REQUEST; 5489 } 5490 5491 5492 l2cap_run(); 5493 return ERROR_CODE_SUCCESS; 5494 } 5495 5496 uint8_t l2cap_enhanced_send_data(uint16_t local_cid, const uint8_t * data, uint16_t size){ 5497 return l2cap_credit_based_send_data(local_cid, data, size); 5498 } 5499 5500 uint8_t l2cap_enhanced_provide_credits(uint16_t local_cid, uint16_t credits){ 5501 return l2cap_credit_based_provide_credits(local_cid, credits); 5502 } 5503 5504 uint8_t l2cap_enhanced_disconnect(uint16_t local_cid){ 5505 return l2cap_credit_based_disconnect(local_cid); 5506 } 5507 5508 #endif 5509