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 MATTHIAS 24 * RINGWALD 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 * 43 * Logical Link Control and Adaption Protocl (L2CAP) 44 * 45 * Created by Matthias Ringwald on 5/16/09. 46 */ 47 48 #include "l2cap.h" 49 #include "hci.h" 50 #include "hci_dump.h" 51 #include "bluetooth_sdp.h" 52 #include "btstack_debug.h" 53 #include "btstack_event.h" 54 #include "btstack_memory.h" 55 56 #ifdef ENABLE_LE_DATA_CHANNELS 57 #include "ble/sm.h" 58 #endif 59 60 #include <stdarg.h> 61 #include <string.h> 62 63 #include <stdio.h> 64 65 // nr of buffered acl packets in outgoing queue to get max performance 66 #define NR_BUFFERED_ACL_PACKETS 3 67 68 // used to cache l2cap rejects, echo, and informational requests 69 #define NR_PENDING_SIGNALING_RESPONSES 3 70 71 // nr of credits provided to remote if credits fall below watermark 72 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK 5 73 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT 5 74 75 // offsets for L2CAP SIGNALING COMMANDS 76 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 77 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 78 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 79 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 80 81 // internal table 82 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL 0 83 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL 1 84 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL 2 85 #define L2CAP_FIXED_CHANNEL_TABLE_SIZE (L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL+1) 86 87 #if defined(ENABLE_LE_DATA_CHANNELS) || defined(ENABLE_CLASSIC) 88 #define L2CAP_USES_CHANNELS 89 #endif 90 91 // prototypes 92 static void l2cap_run(void); 93 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 94 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ); 95 static void l2cap_notify_channel_can_send(void); 96 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel); 97 #ifdef ENABLE_CLASSIC 98 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel); 99 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel); 100 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 101 static inline l2cap_service_t * l2cap_get_service(uint16_t psm); 102 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 103 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 104 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel); 105 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 106 #endif 107 #ifdef ENABLE_LE_DATA_CHANNELS 108 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status); 109 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel); 110 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid); 111 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel); 112 static void l2cap_le_finialize_channel_close(l2cap_channel_t *channel); 113 static inline l2cap_service_t * l2cap_le_get_service(uint16_t psm); 114 #endif 115 #ifdef L2CAP_USES_CHANNELS 116 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size); 117 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid); 118 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 119 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level); 120 #endif 121 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 122 static void l2cap_ertm_notify_channel_can_send(l2cap_channel_t * channel); 123 static void l2cap_ertm_monitor_timeout_callback(btstack_timer_source_t * ts); 124 static void l2cap_ertm_retransmission_timeout_callback(btstack_timer_source_t * ts); 125 #endif 126 127 typedef struct l2cap_fixed_channel { 128 btstack_packet_handler_t callback; 129 uint8_t waiting_for_can_send_now; 130 } l2cap_fixed_channel_t; 131 132 #ifdef ENABLE_CLASSIC 133 static btstack_linked_list_t l2cap_channels; 134 static btstack_linked_list_t l2cap_services; 135 static uint8_t require_security_level2_for_outgoing_sdp; 136 #endif 137 138 #ifdef ENABLE_LE_DATA_CHANNELS 139 static btstack_linked_list_t l2cap_le_channels; 140 static btstack_linked_list_t l2cap_le_services; 141 #endif 142 143 // used to cache l2cap rejects, echo, and informational requests 144 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 145 static int signaling_responses_pending; 146 147 static btstack_packet_callback_registration_t hci_event_callback_registration; 148 static l2cap_fixed_channel_t fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_SIZE]; 149 150 #ifdef ENABLE_BLE 151 // only used for connection parameter update events 152 static btstack_packet_handler_t l2cap_event_packet_handler; 153 #endif 154 155 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 156 157 /* 158 * CRC lookup table for generator polynom D^16 + D^15 + D^2 + 1 159 */ 160 static const uint16_t crc16_table[256] = { 161 0x0000, 0xc0c1, 0xc181, 0x0140, 0xc301, 0x03c0, 0x0280, 0xc241, 0xc601, 0x06c0, 0x0780, 0xc741, 0x0500, 0xc5c1, 0xc481, 0x0440, 162 0xcc01, 0x0cc0, 0x0d80, 0xcd41, 0x0f00, 0xcfc1, 0xce81, 0x0e40, 0x0a00, 0xcac1, 0xcb81, 0x0b40, 0xc901, 0x09c0, 0x0880, 0xc841, 163 0xd801, 0x18c0, 0x1980, 0xd941, 0x1b00, 0xdbc1, 0xda81, 0x1a40, 0x1e00, 0xdec1, 0xdf81, 0x1f40, 0xdd01, 0x1dc0, 0x1c80, 0xdc41, 164 0x1400, 0xd4c1, 0xd581, 0x1540, 0xd701, 0x17c0, 0x1680, 0xd641, 0xd201, 0x12c0, 0x1380, 0xd341, 0x1100, 0xd1c1, 0xd081, 0x1040, 165 0xf001, 0x30c0, 0x3180, 0xf141, 0x3300, 0xf3c1, 0xf281, 0x3240, 0x3600, 0xf6c1, 0xf781, 0x3740, 0xf501, 0x35c0, 0x3480, 0xf441, 166 0x3c00, 0xfcc1, 0xfd81, 0x3d40, 0xff01, 0x3fc0, 0x3e80, 0xfe41, 0xfa01, 0x3ac0, 0x3b80, 0xfb41, 0x3900, 0xf9c1, 0xf881, 0x3840, 167 0x2800, 0xe8c1, 0xe981, 0x2940, 0xeb01, 0x2bc0, 0x2a80, 0xea41, 0xee01, 0x2ec0, 0x2f80, 0xef41, 0x2d00, 0xedc1, 0xec81, 0x2c40, 168 0xe401, 0x24c0, 0x2580, 0xe541, 0x2700, 0xe7c1, 0xe681, 0x2640, 0x2200, 0xe2c1, 0xe381, 0x2340, 0xe101, 0x21c0, 0x2080, 0xe041, 169 0xa001, 0x60c0, 0x6180, 0xa141, 0x6300, 0xa3c1, 0xa281, 0x6240, 0x6600, 0xa6c1, 0xa781, 0x6740, 0xa501, 0x65c0, 0x6480, 0xa441, 170 0x6c00, 0xacc1, 0xad81, 0x6d40, 0xaf01, 0x6fc0, 0x6e80, 0xae41, 0xaa01, 0x6ac0, 0x6b80, 0xab41, 0x6900, 0xa9c1, 0xa881, 0x6840, 171 0x7800, 0xb8c1, 0xb981, 0x7940, 0xbb01, 0x7bc0, 0x7a80, 0xba41, 0xbe01, 0x7ec0, 0x7f80, 0xbf41, 0x7d00, 0xbdc1, 0xbc81, 0x7c40, 172 0xb401, 0x74c0, 0x7580, 0xb541, 0x7700, 0xb7c1, 0xb681, 0x7640, 0x7200, 0xb2c1, 0xb381, 0x7340, 0xb101, 0x71c0, 0x7080, 0xb041, 173 0x5000, 0x90c1, 0x9181, 0x5140, 0x9301, 0x53c0, 0x5280, 0x9241, 0x9601, 0x56c0, 0x5780, 0x9741, 0x5500, 0x95c1, 0x9481, 0x5440, 174 0x9c01, 0x5cc0, 0x5d80, 0x9d41, 0x5f00, 0x9fc1, 0x9e81, 0x5e40, 0x5a00, 0x9ac1, 0x9b81, 0x5b40, 0x9901, 0x59c0, 0x5880, 0x9841, 175 0x8801, 0x48c0, 0x4980, 0x8941, 0x4b00, 0x8bc1, 0x8a81, 0x4a40, 0x4e00, 0x8ec1, 0x8f81, 0x4f40, 0x8d01, 0x4dc0, 0x4c80, 0x8c41, 176 0x4400, 0x84c1, 0x8581, 0x4540, 0x8701, 0x47c0, 0x4680, 0x8641, 0x8201, 0x42c0, 0x4380, 0x8341, 0x4100, 0x81c1, 0x8081, 0x4040, 177 }; 178 179 static uint16_t crc16_calc(uint8_t * data, uint16_t len){ 180 uint16_t crc = 0; // initial value = 0 181 while (len--){ 182 crc = (crc >> 8) ^ crc16_table[ (crc ^ ((uint16_t) *data++)) & 0x00FF ]; 183 } 184 return crc; 185 } 186 187 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){ 188 return (((uint16_t) sar) << 14) | (req_seq << 8) | (final << 7) | (tx_seq << 1) | 0; 189 } 190 191 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){ 192 return (req_seq << 8) | (final << 7) | (poll << 4) | (((int) supervisory_function) << 2) | 1; 193 } 194 195 static int l2cap_next_ertm_seq_nr(int seq_nr){ 196 return (seq_nr + 1) & 0x3f; 197 } 198 199 static int l2cap_ertm_can_store_packet_now(l2cap_channel_t * channel){ 200 // get num free tx buffers 201 int num_tx_buffers_used = channel->tx_write_index - channel->tx_read_index; 202 if (num_tx_buffers_used < 0){ 203 num_tx_buffers_used += channel->num_tx_buffers; 204 } 205 int num_free_tx_buffers = channel->num_tx_buffers - num_tx_buffers_used; 206 // calculate num tx buffers for remote MTU 207 int num_tx_buffers_for_max_remote_mtu; 208 if (channel->remote_mtu <= channel->remote_mps){ 209 // MTU fits into single packet 210 num_tx_buffers_for_max_remote_mtu = 1; 211 } else { 212 // include SDU Length 213 num_tx_buffers_for_max_remote_mtu = (channel->remote_mtu + 2 + (channel->remote_mps - 1)) / channel->remote_mps; 214 } 215 return num_tx_buffers_for_max_remote_mtu <= num_free_tx_buffers; 216 } 217 218 static void l2cap_ertm_next_tx_write_index(l2cap_channel_t * channel){ 219 channel->tx_write_index++; 220 if (channel->tx_write_index < channel->num_tx_buffers) return; 221 channel->tx_write_index = 0; 222 } 223 224 static void l2cap_ertm_start_monitor_timer(l2cap_channel_t * channel){ 225 log_info("Start Monitor timer"); 226 btstack_run_loop_remove_timer(&channel->monitor_timer); 227 btstack_run_loop_set_timer_handler(&channel->monitor_timer, &l2cap_ertm_monitor_timeout_callback); 228 btstack_run_loop_set_timer_context(&channel->monitor_timer, channel); 229 btstack_run_loop_set_timer(&channel->monitor_timer, channel->local_monitor_timeout_ms); 230 btstack_run_loop_add_timer(&channel->monitor_timer); 231 } 232 233 static void l2cap_ertm_stop_monitor_timer(l2cap_channel_t * channel){ 234 log_info("Stop Monitor timer"); 235 btstack_run_loop_remove_timer(&channel->monitor_timer); 236 } 237 238 static void l2cap_ertm_start_retransmission_timer(l2cap_channel_t * channel){ 239 log_info("Start Retransmission timer"); 240 btstack_run_loop_remove_timer(&channel->retransmission_timer); 241 btstack_run_loop_set_timer_handler(&channel->retransmission_timer, &l2cap_ertm_retransmission_timeout_callback); 242 btstack_run_loop_set_timer_context(&channel->retransmission_timer, channel); 243 btstack_run_loop_set_timer(&channel->retransmission_timer, channel->local_retransmission_timeout_ms); 244 btstack_run_loop_add_timer(&channel->retransmission_timer); 245 } 246 247 static void l2cap_ertm_stop_retransmission_timer(l2cap_channel_t * l2cap_channel){ 248 log_info("Stop Retransmission timer"); 249 btstack_run_loop_remove_timer(&l2cap_channel->retransmission_timer); 250 } 251 252 static void l2cap_ertm_monitor_timeout_callback(btstack_timer_source_t * ts){ 253 log_info("Monitor timeout"); 254 l2cap_channel_t * l2cap_channel = (l2cap_channel_t *) btstack_run_loop_get_timer_context(ts); 255 256 // TODO: we assume that it's the oldest packet 257 l2cap_ertm_tx_packet_state_t * tx_state; 258 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 259 260 // check retry count 261 if (tx_state->retry_count < l2cap_channel->remote_max_transmit){ 262 // increment retry count 263 tx_state->retry_count++; 264 265 l2cap_ertm_start_monitor_timer(l2cap_channel); 266 267 // send RR/P=1 268 l2cap_channel->send_supervisor_frame_receiver_ready_poll = 1; 269 } else { 270 log_info("Monitor timer expired & retry count >= max transmit -> disconnect"); 271 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 272 } 273 l2cap_run(); 274 } 275 276 static void l2cap_ertm_retransmission_timeout_callback(btstack_timer_source_t * ts){ 277 log_info("Retransmission timeout"); 278 l2cap_channel_t * l2cap_channel = (l2cap_channel_t *) btstack_run_loop_get_timer_context(ts); 279 280 // TODO: we assume that it's the oldest packet 281 l2cap_ertm_tx_packet_state_t * tx_state; 282 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 283 284 // set retry count = 1 285 tx_state->retry_count = 1; 286 287 // start monitor timer 288 l2cap_ertm_start_monitor_timer(l2cap_channel); 289 290 // send RR/P=1 291 l2cap_channel->send_supervisor_frame_receiver_ready_poll = 1; 292 l2cap_run(); 293 } 294 295 static int l2cap_ertm_send_information_frame(l2cap_channel_t * channel, int index, int final){ 296 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[index]; 297 hci_reserve_packet_buffer(); 298 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 299 uint16_t control = l2cap_encanced_control_field_for_information_frame(tx_state->tx_seq, final, channel->req_seq, tx_state->sar); 300 log_info("I-Frame: control 0x%04x", control); 301 little_endian_store_16(acl_buffer, 8, control); 302 memcpy(&acl_buffer[8+2], &channel->tx_packets_data[index * channel->local_mtu], tx_state->len); 303 // (re-)start retransmission timer on 304 l2cap_ertm_start_retransmission_timer(channel); 305 // send 306 return l2cap_send_prepared(channel->local_cid, 2 + tx_state->len); 307 } 308 309 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){ 310 // get next index for storing packets 311 int index = channel->tx_write_index; 312 313 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[index]; 314 tx_state->tx_seq = channel->next_tx_seq; 315 tx_state->len = len; 316 tx_state->sar = sar; 317 tx_state->retry_count = 0; 318 319 uint8_t * tx_packet = &channel->tx_packets_data[index * channel->local_mtu]; 320 int pos = 0; 321 if (sar == L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU){ 322 little_endian_store_16(tx_packet, 0, sdu_length); 323 pos += 2; 324 } 325 memcpy(&tx_packet[pos], data, len); 326 327 // update 328 channel->next_tx_seq = l2cap_next_ertm_seq_nr(channel->next_tx_seq); 329 l2cap_ertm_next_tx_write_index(channel); 330 331 log_info("l2cap_ertm_store_fragment: after store, tx_read_index %u, tx_write_index %u", channel->tx_read_index, channel->tx_write_index); 332 333 } 334 335 static int l2cap_ertm_send(l2cap_channel_t * channel, uint8_t * data, uint16_t len){ 336 if (len > channel->remote_mtu){ 337 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", channel->local_cid); 338 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 339 } 340 341 // check if it needs to get fragmented 342 if (len > channel->remote_mps){ 343 // fragmentation needed. 344 l2cap_segmentation_and_reassembly_t sar = L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU; 345 int chunk_len; 346 while (len){ 347 switch (sar){ 348 case L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU: 349 chunk_len = channel->remote_mps - 2; // sdu_length 350 l2cap_ertm_store_fragment(channel, sar, len, data, chunk_len); 351 len -= chunk_len; 352 sar = L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU; 353 break; 354 case L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU: 355 chunk_len = channel->remote_mps; 356 if (chunk_len >= len){ 357 sar = L2CAP_SEGMENTATION_AND_REASSEMBLY_END_OF_L2CAP_SDU; 358 chunk_len = len; 359 } 360 l2cap_ertm_store_fragment(channel, sar, len, data, chunk_len); 361 len -= chunk_len; 362 break; 363 default: 364 break; 365 } 366 } 367 368 } else { 369 l2cap_ertm_store_fragment(channel, L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU, 0, data, len); 370 } 371 372 // try to send 373 l2cap_run(); 374 return 0; 375 } 376 377 static uint16_t l2cap_setup_options_ertm(l2cap_channel_t * channel, uint8_t * config_options){ 378 config_options[0] = 0x04; // RETRANSMISSION AND FLOW CONTROL OPTION 379 config_options[1] = 9; // length 380 config_options[2] = (uint8_t) channel->mode; 381 config_options[3] = channel->num_rx_buffers; // == TxWindows size 382 config_options[4] = channel->local_max_transmit; 383 little_endian_store_16( config_options, 5, channel->local_retransmission_timeout_ms); 384 little_endian_store_16( config_options, 7, channel->local_monitor_timeout_ms); 385 little_endian_store_16( config_options, 9, channel->local_mps); 386 return 11; 387 } 388 389 static int l2cap_ertm_send_supervisor_frame(l2cap_channel_t * channel, uint16_t control){ 390 hci_reserve_packet_buffer(); 391 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 392 log_info("S-Frame: control 0x%04x", control); 393 little_endian_store_16(acl_buffer, 8, control); 394 return l2cap_send_prepared(channel->local_cid, 2); 395 } 396 397 static uint8_t l2cap_ertm_validate_local_config(l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size){ 398 399 UNUSED(buffer); 400 UNUSED(size); 401 402 uint8_t result = ERROR_CODE_SUCCESS; 403 if (ertm_config->max_transmit < 1){ 404 log_error("max_transmit must be >= 1"); 405 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 406 } 407 if (ertm_config->retransmission_timeout_ms < 2000){ 408 log_error("retransmission_timeout_ms must be >= 2000 ms"); 409 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 410 } 411 if (ertm_config->monitor_timeout_ms < 12000){ 412 log_error("monitor_timeout_ms must be >= 12000 ms"); 413 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 414 } 415 if (ertm_config->local_mtu < 48){ 416 log_error("local_mtu must be >= 48"); 417 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 418 } 419 if (ertm_config->num_rx_buffers < 1){ 420 log_error("num_rx_buffers must be >= 1"); 421 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 422 } 423 if (ertm_config->num_tx_buffers < 1){ 424 log_error("num_rx_buffers must be >= 1"); 425 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 426 } 427 return result; 428 } 429 430 static void l2cap_ertm_configure_channel(l2cap_channel_t * channel, l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size){ 431 432 channel->mode = L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION; 433 channel->ertm_mandatory = ertm_config->ertm_mandatory; 434 channel->local_max_transmit = ertm_config->max_transmit; 435 channel->local_retransmission_timeout_ms = ertm_config->retransmission_timeout_ms; 436 channel->local_monitor_timeout_ms = ertm_config->monitor_timeout_ms; 437 channel->local_mtu = ertm_config->local_mtu; 438 channel->num_rx_buffers = ertm_config->num_rx_buffers; 439 channel->num_tx_buffers = ertm_config->num_tx_buffers; 440 441 // align buffer to 16-byte boundary, just in case 442 int bytes_till_alignment = 16 - (((uintptr_t) buffer) & 0x0f); 443 buffer += bytes_till_alignment; 444 size -= bytes_till_alignment; 445 446 // setup state buffers 447 uint32_t pos = 0; 448 channel->rx_packets_state = (l2cap_ertm_rx_packet_state_t *) &buffer[pos]; 449 pos += ertm_config->num_rx_buffers * sizeof(l2cap_ertm_rx_packet_state_t); 450 channel->tx_packets_state = (l2cap_ertm_tx_packet_state_t *) &buffer[pos]; 451 pos += ertm_config->num_tx_buffers * sizeof(l2cap_ertm_tx_packet_state_t); 452 453 // setup reassembly buffer 454 channel->reassembly_buffer = &buffer[pos]; 455 pos += ertm_config->local_mtu; 456 457 // divide rest of data equally 458 channel->local_mps = (size - pos) / (ertm_config->num_rx_buffers + ertm_config->num_tx_buffers); 459 log_info("Local MPS: %u", channel->local_mtu); 460 channel->rx_packets_data = &buffer[pos]; 461 pos += ertm_config->num_rx_buffers * channel->local_mtu; 462 channel->tx_packets_data = &buffer[pos]; 463 } 464 465 uint8_t l2cap_create_ertm_channel(btstack_packet_handler_t packet_handler, bd_addr_t address, uint16_t psm, 466 l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size, uint16_t * out_local_cid){ 467 468 log_info("L2CAP_CREATE_ERTM_CHANNEL addr %s, psm 0x%x, local mtu %u", bd_addr_to_str(address), psm, ertm_config->local_mtu); 469 470 // validate local config 471 uint8_t result = l2cap_ertm_validate_local_config(ertm_config, buffer, size); 472 if (result) return result; 473 474 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, ertm_config->local_mtu, LEVEL_0); 475 if (!channel) { 476 return BTSTACK_MEMORY_ALLOC_FAILED; 477 } 478 479 // configure ERTM 480 l2cap_ertm_configure_channel(channel, ertm_config, buffer, size); 481 482 // add to connections list 483 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 484 485 // store local_cid 486 if (out_local_cid){ 487 *out_local_cid = channel->local_cid; 488 } 489 490 // check if hci connection is already usable 491 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 492 if (conn){ 493 log_info("l2cap_create_channel, hci connection already exists"); 494 l2cap_handle_connection_complete(conn->con_handle, channel); 495 // check if remote supported fearures are already received 496 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 497 l2cap_handle_remote_supported_features_received(channel); 498 } 499 } 500 501 l2cap_run(); 502 503 return 0; 504 } 505 506 static void l2cap_ertm_notify_channel_can_send(l2cap_channel_t * channel){ 507 if (l2cap_ertm_can_store_packet_now(channel)){ 508 channel->waiting_for_can_send_now = 0; 509 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 510 } 511 } 512 513 uint8_t l2cap_accept_ertm_connection(uint16_t local_cid, l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size){ 514 515 log_info("L2CAP_ACCEPT_ERTM_CONNECTION local_cid 0x%x", local_cid); 516 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 517 if (!channel) { 518 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 519 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 520 } 521 522 // validate local config 523 uint8_t result = l2cap_ertm_validate_local_config(ertm_config, buffer, size); 524 if (result) return result; 525 526 // configure L2CAP ERTM 527 l2cap_ertm_configure_channel(channel, ertm_config, buffer, size); 528 529 // continue 530 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 531 532 // process 533 l2cap_run(); 534 535 return ERROR_CODE_SUCCESS; 536 } 537 538 uint8_t l2cap_ertm_set_busy(uint16_t local_cid){ 539 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 540 if (!channel) { 541 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 542 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 543 } 544 if (!channel->local_busy){ 545 channel->local_busy = 1; 546 channel->send_supervisor_frame_receiver_not_ready = 1; 547 l2cap_run(); 548 } 549 return ERROR_CODE_SUCCESS; 550 } 551 552 uint8_t l2cap_ertm_set_ready(uint16_t local_cid){ 553 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 554 if (!channel) { 555 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 556 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 557 } 558 if (channel->local_busy){ 559 channel->local_busy = 0; 560 channel->send_supervisor_frame_receiver_ready_poll = 1; 561 l2cap_run(); 562 } 563 return ERROR_CODE_SUCCESS; 564 } 565 566 // Process-ReqSeq 567 static void l2cap_ertm_process_req_seq(l2cap_channel_t * l2cap_channel, uint8_t req_seq){ 568 int num_buffers_acked = 0; 569 l2cap_ertm_tx_packet_state_t * tx_state; 570 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); 571 while (1){ 572 573 // no unack packets left 574 if (l2cap_channel->unacked_frames == 0) { 575 // stop retransmission timer 576 l2cap_ertm_stop_retransmission_timer(l2cap_channel); 577 break; 578 } 579 580 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 581 // calc delta 582 int delta = (req_seq - tx_state->tx_seq) & 0x03f; 583 if (delta == 0) break; // all packets acknowledged 584 if (delta > l2cap_channel->remote_tx_window_size) break; 585 586 num_buffers_acked++; 587 l2cap_channel->unacked_frames--; 588 log_info("RR seq %u => packet with tx_seq %u done", req_seq, tx_state->tx_seq); 589 590 l2cap_channel->tx_read_index++; 591 if (l2cap_channel->tx_read_index >= l2cap_channel->num_rx_buffers){ 592 l2cap_channel->tx_read_index = 0; 593 } 594 } 595 596 if (num_buffers_acked){ 597 l2cap_ertm_notify_channel_can_send(l2cap_channel); 598 } 599 } 600 601 static l2cap_ertm_tx_packet_state_t * l2cap_ertm_get_tx_state(l2cap_channel_t * l2cap_channel, uint8_t tx_seq){ 602 int i; 603 for (i=0;i<l2cap_channel->num_tx_buffers;i++){ 604 l2cap_ertm_tx_packet_state_t * tx_state = &l2cap_channel->tx_packets_state[i]; 605 if (tx_state->tx_seq == tx_seq) return tx_state; 606 } 607 return NULL; 608 } 609 610 // @param delta number of frames in the future, >= 1 611 static void l2cap_ertm_handle_out_of_sequence_sdu(l2cap_channel_t * l2cap_channel, l2cap_segmentation_and_reassembly_t sar, int delta, uint8_t * payload, uint16_t size){ 612 log_info("Store SDU with delta %u", delta); 613 // get rx state for packet to store 614 int index = l2cap_channel->rx_store_index + delta - 1; 615 if (index > l2cap_channel->num_rx_buffers){ 616 index -= l2cap_channel->num_rx_buffers; 617 } 618 log_info("Index of packet to store %u", index); 619 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 620 // check if buffer is free 621 if (rx_state->valid){ 622 log_error("Packet buffer already used"); 623 return; 624 } 625 rx_state->valid = 1; 626 rx_state->sar = sar; 627 rx_state->len = size; 628 uint8_t * rx_buffer = &l2cap_channel->rx_packets_data[index]; 629 memcpy(rx_buffer, payload, size); 630 } 631 632 static void l2cap_ertm_handle_in_sequence_sdu(l2cap_channel_t * l2cap_channel, l2cap_segmentation_and_reassembly_t sar, uint8_t * payload, uint16_t size){ 633 switch (sar){ 634 case L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU: 635 // packet complete -> disapatch 636 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, payload, size); 637 break; 638 case L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU: 639 // TODO: check if reassembly started 640 // TODO: check sdu_len against local mtu 641 l2cap_channel->reassembly_sdu_length = little_endian_read_16(payload, 0); 642 payload += 2; 643 size -= 2; 644 memcpy(&l2cap_channel->reassembly_buffer[0], payload, size); 645 l2cap_channel->reassembly_pos = size; 646 break; 647 case L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU: 648 memcpy(&l2cap_channel->reassembly_buffer[l2cap_channel->reassembly_pos], payload, size); 649 l2cap_channel->reassembly_pos += size; 650 break; 651 case L2CAP_SEGMENTATION_AND_REASSEMBLY_END_OF_L2CAP_SDU: 652 memcpy(&l2cap_channel->reassembly_buffer[l2cap_channel->reassembly_pos], payload, size); 653 l2cap_channel->reassembly_pos += size; 654 // packet complete -> disapatch 655 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->reassembly_buffer, l2cap_channel->reassembly_pos); 656 l2cap_channel->reassembly_pos = 0; 657 break; 658 } 659 } 660 661 #endif 662 663 664 static uint16_t l2cap_fixed_channel_table_channel_id_for_index(int index){ 665 switch (index){ 666 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL: 667 return L2CAP_CID_ATTRIBUTE_PROTOCOL; 668 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL: 669 return L2CAP_CID_SECURITY_MANAGER_PROTOCOL; 670 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL: 671 return L2CAP_CID_CONNECTIONLESS_CHANNEL; 672 default: 673 return 0; 674 } 675 } 676 static int l2cap_fixed_channel_table_index_for_channel_id(uint16_t channel_id){ 677 switch (channel_id){ 678 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 679 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL; 680 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 681 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL; 682 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 683 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL; 684 default: 685 return -1; 686 } 687 } 688 689 static int l2cap_fixed_channel_table_index_is_le(int index){ 690 if (index == L2CAP_CID_CONNECTIONLESS_CHANNEL) return 0; 691 return 1; 692 } 693 694 void l2cap_init(void){ 695 signaling_responses_pending = 0; 696 697 #ifdef ENABLE_CLASSIC 698 l2cap_channels = NULL; 699 l2cap_services = NULL; 700 require_security_level2_for_outgoing_sdp = 0; 701 #endif 702 703 #ifdef ENABLE_LE_DATA_CHANNELS 704 l2cap_le_services = NULL; 705 l2cap_le_channels = NULL; 706 #endif 707 708 #ifdef ENABLE_BLE 709 l2cap_event_packet_handler = NULL; 710 #endif 711 memset(fixed_channels, 0, sizeof(fixed_channels)); 712 713 // 714 // register callback with HCI 715 // 716 hci_event_callback_registration.callback = &l2cap_hci_event_handler; 717 hci_add_event_handler(&hci_event_callback_registration); 718 719 hci_register_acl_packet_handler(&l2cap_acl_handler); 720 721 #ifdef ENABLE_CLASSIC 722 gap_connectable_control(0); // no services yet 723 #endif 724 } 725 726 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 727 #ifdef ENABLE_BLE 728 l2cap_event_packet_handler = handler; 729 #else 730 UNUSED(handler); 731 #endif 732 } 733 734 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ 735 UNUSED(con_handle); 736 737 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 738 if (index < 0) return; 739 fixed_channels[index].waiting_for_can_send_now = 1; 740 l2cap_notify_channel_can_send(); 741 } 742 743 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ 744 UNUSED(channel_id); 745 746 return hci_can_send_acl_packet_now(con_handle); 747 } 748 749 uint8_t *l2cap_get_outgoing_buffer(void){ 750 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 751 } 752 753 int l2cap_reserve_packet_buffer(void){ 754 return hci_reserve_packet_buffer(); 755 } 756 757 void l2cap_release_packet_buffer(void){ 758 hci_release_packet_buffer(); 759 } 760 761 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){ 762 // 0 - Connection handle : PB=pb : BC=00 763 little_endian_store_16(acl_buffer, 0, con_handle | (packet_boundary << 12) | (0 << 14)); 764 // 2 - ACL length 765 little_endian_store_16(acl_buffer, 2, len + 4); 766 // 4 - L2CAP packet length 767 little_endian_store_16(acl_buffer, 4, len + 0); 768 // 6 - L2CAP channel DEST 769 little_endian_store_16(acl_buffer, 6, remote_cid); 770 } 771 772 // assumption - only on LE connections 773 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 774 775 if (!hci_is_packet_buffer_reserved()){ 776 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 777 return BTSTACK_ACL_BUFFERS_FULL; 778 } 779 780 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 781 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 782 return BTSTACK_ACL_BUFFERS_FULL; 783 } 784 785 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 786 787 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 788 l2cap_setup_header(acl_buffer, con_handle, 0, cid, len); 789 // send 790 return hci_send_acl_packet_buffer(len+8); 791 } 792 793 // assumption - only on LE connections 794 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 795 796 if (!hci_can_send_acl_packet_now(con_handle)){ 797 log_info("l2cap_send cid 0x%02x, cannot send", cid); 798 return BTSTACK_ACL_BUFFERS_FULL; 799 } 800 801 hci_reserve_packet_buffer(); 802 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 803 804 memcpy(&acl_buffer[8], data, len); 805 806 return l2cap_send_prepared_connectionless(con_handle, cid, len); 807 } 808 809 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { 810 log_debug("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); 811 uint8_t event[4]; 812 event[0] = L2CAP_EVENT_CAN_SEND_NOW; 813 event[1] = sizeof(event) - 2; 814 little_endian_store_16(event, 2, channel); 815 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 816 packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); 817 } 818 819 #ifdef L2CAP_USES_CHANNELS 820 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 821 (* (channel->packet_handler))(type, channel->local_cid, data, size); 822 } 823 824 static void l2cap_emit_simple_event_with_cid(l2cap_channel_t * channel, uint8_t event_code){ 825 uint8_t event[4]; 826 event[0] = event_code; 827 event[1] = sizeof(event) - 2; 828 little_endian_store_16(event, 2, channel->local_cid); 829 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 830 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 831 } 832 #endif 833 834 #ifdef ENABLE_CLASSIC 835 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 836 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", 837 status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 838 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 839 uint8_t event[24]; 840 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 841 event[1] = sizeof(event) - 2; 842 event[2] = status; 843 reverse_bd_addr(channel->address, &event[3]); 844 little_endian_store_16(event, 9, channel->con_handle); 845 little_endian_store_16(event, 11, channel->psm); 846 little_endian_store_16(event, 13, channel->local_cid); 847 little_endian_store_16(event, 15, channel->remote_cid); 848 little_endian_store_16(event, 17, channel->local_mtu); 849 little_endian_store_16(event, 19, channel->remote_mtu); 850 little_endian_store_16(event, 21, channel->flush_timeout); 851 event[23] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 852 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 853 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 854 } 855 856 static void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 857 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 858 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 859 } 860 861 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel) { 862 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 863 bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); 864 uint8_t event[16]; 865 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 866 event[1] = sizeof(event) - 2; 867 reverse_bd_addr(channel->address, &event[2]); 868 little_endian_store_16(event, 8, channel->con_handle); 869 little_endian_store_16(event, 10, channel->psm); 870 little_endian_store_16(event, 12, channel->local_cid); 871 little_endian_store_16(event, 14, channel->remote_cid); 872 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 873 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 874 } 875 876 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 877 btstack_linked_list_iterator_t it; 878 btstack_linked_list_iterator_init(&it, &l2cap_channels); 879 while (btstack_linked_list_iterator_has_next(&it)){ 880 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 881 if ( channel->local_cid == local_cid) { 882 return channel; 883 } 884 } 885 return NULL; 886 } 887 888 /// 889 890 void l2cap_request_can_send_now_event(uint16_t local_cid){ 891 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 892 if (!channel) return; 893 channel->waiting_for_can_send_now = 1; 894 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 895 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 896 l2cap_ertm_notify_channel_can_send(channel); 897 return; 898 } 899 #endif 900 l2cap_notify_channel_can_send(); 901 } 902 903 int l2cap_can_send_packet_now(uint16_t local_cid){ 904 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 905 if (!channel) return 0; 906 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 907 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 908 return l2cap_ertm_can_store_packet_now(channel); 909 } 910 #endif 911 return hci_can_send_acl_packet_now(channel->con_handle); 912 } 913 914 int l2cap_can_send_prepared_packet_now(uint16_t local_cid){ 915 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 916 if (!channel) return 0; 917 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 918 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 919 return 0; 920 } 921 #endif 922 return hci_can_send_prepared_acl_packet_now(channel->con_handle); 923 } 924 925 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 926 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 927 if (channel) { 928 return channel->remote_mtu; 929 } 930 return 0; 931 } 932 933 static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ 934 btstack_linked_list_iterator_t it; 935 btstack_linked_list_iterator_init(&it, &l2cap_channels); 936 while (btstack_linked_list_iterator_has_next(&it)){ 937 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 938 if ( &channel->rtx == ts) { 939 return channel; 940 } 941 } 942 return NULL; 943 } 944 945 static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ 946 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 947 if (!channel) return; 948 949 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 950 951 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 952 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 953 // notify client 954 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 955 956 // discard channel 957 // no need to stop timer here, it is removed from list during timer callback 958 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 959 btstack_memory_l2cap_channel_free(channel); 960 } 961 962 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 963 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 964 btstack_run_loop_remove_timer(&channel->rtx); 965 } 966 967 static void l2cap_start_rtx(l2cap_channel_t * channel){ 968 l2cap_stop_rtx(channel); 969 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 970 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 971 btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 972 btstack_run_loop_add_timer(&channel->rtx); 973 } 974 975 static void l2cap_start_ertx(l2cap_channel_t * channel){ 976 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 977 l2cap_stop_rtx(channel); 978 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 979 btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 980 btstack_run_loop_add_timer(&channel->rtx); 981 } 982 983 void l2cap_require_security_level_2_for_outgoing_sdp(void){ 984 require_security_level2_for_outgoing_sdp = 1; 985 } 986 987 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 988 return (psm == BLUETOOTH_PROTOCOL_SDP) && (!require_security_level2_for_outgoing_sdp); 989 } 990 991 static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 992 if (!hci_can_send_acl_packet_now(handle)){ 993 log_info("l2cap_send_signaling_packet, cannot send"); 994 return BTSTACK_ACL_BUFFERS_FULL; 995 } 996 997 // log_info("l2cap_send_signaling_packet type %u", cmd); 998 hci_reserve_packet_buffer(); 999 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1000 va_list argptr; 1001 va_start(argptr, identifier); 1002 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 1003 va_end(argptr); 1004 // log_info("l2cap_send_signaling_packet con %u!", handle); 1005 return hci_send_acl_packet_buffer(len); 1006 } 1007 1008 // assumption - only on Classic connections 1009 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 1010 1011 if (!hci_is_packet_buffer_reserved()){ 1012 log_error("l2cap_send_prepared called without reserving packet first"); 1013 return BTSTACK_ACL_BUFFERS_FULL; 1014 } 1015 1016 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1017 if (!channel) { 1018 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 1019 return -1; // TODO: define error 1020 } 1021 1022 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 1023 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 1024 return BTSTACK_ACL_BUFFERS_FULL; 1025 } 1026 1027 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 1028 1029 int fcs_size = 0; 1030 1031 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1032 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1033 fcs_size = 2; 1034 } 1035 #endif 1036 1037 // set non-flushable packet boundary flag if supported on Controller 1038 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1039 uint8_t packet_boundary_flag = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 1040 l2cap_setup_header(acl_buffer, channel->con_handle, packet_boundary_flag, channel->remote_cid, len + fcs_size); 1041 1042 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1043 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1044 // calculate FCS over l2cap data 1045 uint16_t fcs = crc16_calc(acl_buffer + 4, 4 + len); 1046 log_info("I-Frame: fcs 0x%04x", fcs); 1047 little_endian_store_16(acl_buffer, 8 + len, fcs); 1048 } 1049 #endif 1050 1051 // send 1052 return hci_send_acl_packet_buffer(len+8+fcs_size); 1053 } 1054 1055 // assumption - only on Classic connections 1056 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 1057 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1058 if (!channel) { 1059 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 1060 return -1; // TODO: define error 1061 } 1062 1063 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1064 // send in ERTM 1065 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1066 return l2cap_ertm_send(channel, data, len); 1067 } 1068 #endif 1069 1070 if (len > channel->remote_mtu){ 1071 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 1072 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 1073 } 1074 1075 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 1076 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 1077 return BTSTACK_ACL_BUFFERS_FULL; 1078 } 1079 1080 hci_reserve_packet_buffer(); 1081 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1082 memcpy(&acl_buffer[8], data, len); 1083 return l2cap_send_prepared(local_cid, len); 1084 } 1085 1086 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ 1087 return l2cap_send_signaling_packet(con_handle, ECHO_REQUEST, 0x77, len, data); 1088 } 1089 1090 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 1091 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 1092 } 1093 1094 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 1095 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 1096 } 1097 #endif 1098 1099 1100 #ifdef ENABLE_BLE 1101 static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 1102 1103 if (!hci_can_send_acl_packet_now(handle)){ 1104 log_info("l2cap_send_le_signaling_packet, cannot send"); 1105 return BTSTACK_ACL_BUFFERS_FULL; 1106 } 1107 1108 // log_info("l2cap_send_le_signaling_packet type %u", cmd); 1109 hci_reserve_packet_buffer(); 1110 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1111 va_list argptr; 1112 va_start(argptr, identifier); 1113 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 1114 va_end(argptr); 1115 // log_info("l2cap_send_le_signaling_packet con %u!", handle); 1116 return hci_send_acl_packet_buffer(len); 1117 } 1118 #endif 1119 1120 uint16_t l2cap_max_mtu(void){ 1121 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 1122 } 1123 1124 uint16_t l2cap_max_le_mtu(void){ 1125 return l2cap_max_mtu(); 1126 } 1127 1128 #ifdef ENABLE_CLASSIC 1129 1130 static uint16_t l2cap_setup_options_mtu(l2cap_channel_t * channel, uint8_t * config_options){ 1131 config_options[0] = 1; // MTU 1132 config_options[1] = 2; // len param 1133 little_endian_store_16(config_options, 2, channel->local_mtu); 1134 return 4; 1135 } 1136 1137 static uint16_t l2cap_setup_options(l2cap_channel_t * channel, uint8_t * config_options){ 1138 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1139 // use ERTM options if supported 1140 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1141 if ((connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_DONE) && (connection->l2cap_state.extended_feature_mask & 0x08)){ 1142 return l2cap_setup_options_ertm(channel, config_options); 1143 1144 } 1145 #endif 1146 return l2cap_setup_options_mtu(channel, config_options); 1147 } 1148 1149 static uint32_t l2cap_extended_features_mask(void){ 1150 // extended features request supported, features: fixed channels, unicast connectionless data reception 1151 uint32_t features = 0x280; 1152 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1153 features |= 0x0008; 1154 #endif 1155 return features; 1156 } 1157 #endif 1158 1159 // MARK: L2CAP_RUN 1160 // process outstanding signaling tasks 1161 static void l2cap_run(void){ 1162 1163 // log_info("l2cap_run: entered"); 1164 1165 // check pending signaling responses 1166 while (signaling_responses_pending){ 1167 1168 hci_con_handle_t handle = signaling_responses[0].handle; 1169 1170 if (!hci_can_send_acl_packet_now(handle)) break; 1171 1172 uint8_t sig_id = signaling_responses[0].sig_id; 1173 uint8_t response_code = signaling_responses[0].code; 1174 uint16_t info_type = signaling_responses[0].data; // INFORMATION_REQUEST 1175 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 1176 #ifdef ENABLE_CLASSIC 1177 uint16_t source_cid = signaling_responses[0].cid; // CONNECTION_REQUEST 1178 #endif 1179 UNUSED(info_type); 1180 1181 // remove first item before sending (to avoid sending response mutliple times) 1182 signaling_responses_pending--; 1183 int i; 1184 for (i=0; i < signaling_responses_pending; i++){ 1185 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 1186 } 1187 1188 switch (response_code){ 1189 #ifdef ENABLE_CLASSIC 1190 case CONNECTION_REQUEST: 1191 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, source_cid, 0, result, 0); 1192 // also disconnect if result is 0x0003 - security blocked 1193 if (result == 0x0003){ 1194 hci_disconnect_security_block(handle); 1195 } 1196 break; 1197 case ECHO_REQUEST: 1198 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 1199 break; 1200 case INFORMATION_REQUEST: 1201 switch (info_type){ 1202 case L2CAP_INFO_TYPE_CONNECTIONLESS_MTU: { 1203 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 1204 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 0, sizeof(connectionless_mtu), &connectionless_mtu); 1205 } 1206 break; 1207 case L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED: { 1208 uint32_t features = l2cap_extended_features_mask(); 1209 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 0, sizeof(features), &features); 1210 } 1211 break; 1212 case L2CAP_INFO_TYPE_FIXED_CHANNELS_SUPPORTED: { 1213 uint8_t map[8]; 1214 memset(map, 0, 8); 1215 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 1216 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 0, sizeof(map), &map); 1217 } 1218 break; 1219 default: 1220 // all other types are not supported 1221 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 1, 0, NULL); 1222 break; 1223 } 1224 break; 1225 case COMMAND_REJECT: 1226 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 1227 break; 1228 #endif 1229 #ifdef ENABLE_BLE 1230 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1231 l2cap_send_le_signaling_packet(handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, sig_id, 0, 0, 0, 0, result); 1232 break; 1233 case COMMAND_REJECT_LE: 1234 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 1235 break; 1236 #endif 1237 default: 1238 // should not happen 1239 break; 1240 } 1241 } 1242 1243 btstack_linked_list_iterator_t it; 1244 UNUSED(it); 1245 1246 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1247 // send l2cap information request if neccessary 1248 hci_connections_get_iterator(&it); 1249 while(btstack_linked_list_iterator_has_next(&it)){ 1250 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1251 if (connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST){ 1252 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W4_EXTENDED_FEATURE_RESPONSE; 1253 // send information request for extended features 1254 uint8_t sig_id = l2cap_next_sig_id(); 1255 uint8_t info_type = L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED; 1256 l2cap_send_signaling_packet(connection->con_handle, INFORMATION_REQUEST, sig_id, info_type); 1257 return; 1258 } 1259 } 1260 #endif 1261 1262 #ifdef ENABLE_CLASSIC 1263 uint8_t config_options[10]; 1264 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1265 while (btstack_linked_list_iterator_has_next(&it)){ 1266 1267 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1268 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 1269 switch (channel->state){ 1270 1271 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1272 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 1273 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1274 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 1275 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 1276 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 1277 } 1278 break; 1279 1280 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1281 if (!hci_can_send_command_packet_now()) break; 1282 // send connection request - set state first 1283 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 1284 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 1285 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 1286 break; 1287 1288 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 1289 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1290 channel->state = L2CAP_STATE_INVALID; 1291 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 1292 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 1293 l2cap_stop_rtx(channel); 1294 btstack_linked_list_iterator_remove(&it); 1295 btstack_memory_l2cap_channel_free(channel); 1296 break; 1297 1298 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 1299 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1300 channel->state = L2CAP_STATE_CONFIG; 1301 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1302 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 1303 break; 1304 1305 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 1306 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1307 // success, start l2cap handshake 1308 channel->local_sig_id = l2cap_next_sig_id(); 1309 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 1310 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 1311 l2cap_start_rtx(channel); 1312 break; 1313 1314 case L2CAP_STATE_CONFIG: 1315 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1316 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 1317 uint16_t flags = 0; 1318 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1319 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 1320 flags = 1; 1321 } else { 1322 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 1323 } 1324 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 1325 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 1326 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 1327 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1328 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED){ 1329 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 1330 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 1331 uint16_t options_size = l2cap_setup_options(channel, config_options); 1332 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS, options_size, &config_options); 1333 #endif 1334 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 1335 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1336 uint16_t options_size = l2cap_setup_options(channel, config_options); 1337 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_SUCCESS, options_size, &config_options); 1338 } else { 1339 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_SUCCESS, 0, NULL); 1340 } 1341 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1342 } 1343 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 1344 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1345 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 1346 channel->local_sig_id = l2cap_next_sig_id(); 1347 uint16_t options_size = l2cap_setup_options(channel, config_options); 1348 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, options_size, &config_options); 1349 l2cap_start_rtx(channel); 1350 } 1351 if (l2cap_channel_ready_for_open(channel)){ 1352 channel->state = L2CAP_STATE_OPEN; 1353 l2cap_emit_channel_opened(channel, 0); // success 1354 } 1355 break; 1356 1357 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 1358 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1359 channel->state = L2CAP_STATE_INVALID; 1360 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 1361 // 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 :) 1362 l2cap_finialize_channel_close(channel); // -- remove from list 1363 break; 1364 1365 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1366 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1367 channel->local_sig_id = l2cap_next_sig_id(); 1368 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 1369 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 1370 break; 1371 default: 1372 break; 1373 } 1374 1375 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1376 // send s-frame to acknowledge received packets 1377 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1378 1379 if (channel->tx_send_index != channel->tx_write_index){ 1380 // check remote tx window 1381 log_info("unacknowledged_packets %u, remote tx window size %u", channel->unacked_frames, channel->remote_tx_window_size); 1382 if (channel->unacked_frames < channel->remote_tx_window_size){ 1383 channel->unacked_frames++; 1384 int index = channel->tx_send_index; 1385 channel->tx_send_index++; 1386 if (channel->tx_send_index >= channel->num_tx_buffers){ 1387 channel->tx_send_index = 0; 1388 } 1389 l2cap_ertm_send_information_frame(channel, index, 0); // final = 0 1390 continue; 1391 } 1392 } 1393 1394 if (channel->send_supervisor_frame_receiver_ready){ 1395 channel->send_supervisor_frame_receiver_ready = 0; 1396 log_info("Send S-Frame: RR %u, final %u", channel->req_seq, channel->set_final_bit_after_packet_with_poll_bit_set); 1397 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); 1398 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1399 l2cap_ertm_send_supervisor_frame(channel, control); 1400 continue; 1401 } 1402 if (channel->send_supervisor_frame_receiver_ready_poll){ 1403 channel->send_supervisor_frame_receiver_ready_poll = 0; 1404 log_info("Send S-Frame: RR %u with poll=1 ", channel->req_seq); 1405 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY, 1, 0, channel->req_seq); 1406 l2cap_ertm_send_supervisor_frame(channel, control); 1407 continue; 1408 } 1409 if (channel->send_supervisor_frame_receiver_not_ready){ 1410 channel->send_supervisor_frame_receiver_not_ready = 0; 1411 log_info("Send S-Frame: RNR %u", channel->req_seq); 1412 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY, 0, 0, channel->req_seq); 1413 l2cap_ertm_send_supervisor_frame(channel, control); 1414 continue; 1415 } 1416 if (channel->send_supervisor_frame_reject){ 1417 channel->send_supervisor_frame_reject = 0; 1418 log_info("Send S-Frame: REJ %u", channel->req_seq); 1419 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT, 0, 0, channel->req_seq); 1420 l2cap_ertm_send_supervisor_frame(channel, control); 1421 continue; 1422 } 1423 if (channel->send_supervisor_frame_selective_reject){ 1424 channel->send_supervisor_frame_selective_reject = 0; 1425 log_info("Send S-Frame: SREJ %u", channel->expected_tx_seq); 1426 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); 1427 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1428 l2cap_ertm_send_supervisor_frame(channel, control); 1429 continue; 1430 } 1431 1432 if (channel->srej_active){ 1433 int i; 1434 for (i=0;i<channel->num_tx_buffers;i++){ 1435 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[i]; 1436 if (tx_state->retransmission_requested) { 1437 tx_state->retransmission_requested = 0; 1438 uint8_t final = channel->set_final_bit_after_packet_with_poll_bit_set; 1439 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1440 l2cap_ertm_send_information_frame(channel, i, final); 1441 break; 1442 } 1443 } 1444 if (i == channel->num_tx_buffers){ 1445 // no retransmission request found 1446 channel->srej_active = 0; 1447 } else { 1448 // packet was sent 1449 continue; 1450 } 1451 } 1452 #endif 1453 1454 } 1455 #endif 1456 1457 #ifdef ENABLE_LE_DATA_CHANNELS 1458 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1459 while (btstack_linked_list_iterator_has_next(&it)){ 1460 uint8_t * acl_buffer; 1461 uint8_t * l2cap_payload; 1462 uint16_t pos; 1463 uint16_t payload_size; 1464 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1465 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 1466 switch (channel->state){ 1467 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 1468 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1469 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 1470 // le psm, source cid, mtu, mps, initial credits 1471 channel->local_sig_id = l2cap_next_sig_id(); 1472 channel->credits_incoming = channel->new_credits_incoming; 1473 channel->new_credits_incoming = 0; 1474 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, 23, channel->credits_incoming); 1475 break; 1476 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 1477 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1478 // TODO: support larger MPS 1479 channel->state = L2CAP_STATE_OPEN; 1480 channel->credits_incoming = channel->new_credits_incoming; 1481 channel->new_credits_incoming = 0; 1482 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->local_mtu, 23, channel->credits_incoming, 0); 1483 // notify client 1484 l2cap_emit_le_channel_opened(channel, 0); 1485 break; 1486 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 1487 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1488 channel->state = L2CAP_STATE_INVALID; 1489 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); 1490 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 1491 l2cap_stop_rtx(channel); 1492 btstack_linked_list_iterator_remove(&it); 1493 btstack_memory_l2cap_channel_free(channel); 1494 break; 1495 case L2CAP_STATE_OPEN: 1496 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1497 1498 // send credits 1499 if (channel->new_credits_incoming){ 1500 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 1501 channel->local_sig_id = l2cap_next_sig_id(); 1502 uint16_t new_credits = channel->new_credits_incoming; 1503 channel->new_credits_incoming = 0; 1504 channel->credits_incoming += new_credits; 1505 l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); 1506 break; 1507 } 1508 1509 // send data 1510 if (!channel->send_sdu_buffer) break; 1511 if (!channel->credits_outgoing) break; 1512 1513 // send part of SDU 1514 hci_reserve_packet_buffer(); 1515 acl_buffer = hci_get_outgoing_packet_buffer(); 1516 l2cap_payload = acl_buffer + 8; 1517 pos = 0; 1518 if (!channel->send_sdu_pos){ 1519 // store SDU len 1520 channel->send_sdu_pos += 2; 1521 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 1522 pos += 2; 1523 } 1524 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 1525 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); 1526 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 1527 pos += payload_size; 1528 channel->send_sdu_pos += payload_size; 1529 l2cap_setup_header(acl_buffer, channel->con_handle, 0, channel->remote_cid, pos); 1530 // done 1531 1532 channel->credits_outgoing--; 1533 1534 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 1535 channel->send_sdu_buffer = NULL; 1536 // send done event 1537 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_PACKET_SENT); 1538 // inform about can send now 1539 l2cap_le_notify_channel_can_send(channel); 1540 } 1541 hci_send_acl_packet_buffer(8 + pos); 1542 break; 1543 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1544 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1545 channel->local_sig_id = l2cap_next_sig_id(); 1546 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 1547 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 1548 break; 1549 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 1550 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1551 channel->state = L2CAP_STATE_INVALID; 1552 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 1553 l2cap_le_finialize_channel_close(channel); // -- remove from list 1554 break; 1555 default: 1556 break; 1557 } 1558 } 1559 #endif 1560 1561 #ifdef ENABLE_BLE 1562 // send l2cap con paramter update if necessary 1563 hci_connections_get_iterator(&it); 1564 while(btstack_linked_list_iterator_has_next(&it)){ 1565 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1566 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 1567 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 1568 switch (connection->le_con_parameter_update_state){ 1569 case CON_PARAMETER_UPDATE_SEND_REQUEST: 1570 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 1571 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 1572 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 1573 break; 1574 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 1575 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 1576 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 1577 break; 1578 case CON_PARAMETER_UPDATE_DENY: 1579 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 1580 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 1581 break; 1582 default: 1583 break; 1584 } 1585 } 1586 #endif 1587 1588 // log_info("l2cap_run: exit"); 1589 } 1590 1591 #ifdef ENABLE_CLASSIC 1592 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 1593 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 1594 log_info("l2cap_handle_connection_complete expected state"); 1595 // success, start l2cap handshake 1596 channel->con_handle = con_handle; 1597 // check remote SSP feature first 1598 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 1599 } 1600 } 1601 1602 static void l2cap_ready_to_connect(l2cap_channel_t * channel){ 1603 1604 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1605 // assumption: outgoing connection 1606 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1607 if (connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_IDLE){ 1608 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 1609 channel->state = L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES; 1610 return; 1611 } 1612 #endif 1613 1614 // fine, go ahead 1615 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1616 } 1617 1618 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 1619 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 1620 1621 // we have been waiting for remote supported features, if both support SSP, 1622 log_info("l2cap received remote supported features, sec_level_0_allowed for psm %u = %u", channel->psm, l2cap_security_level_0_allowed_for_PSM(channel->psm)); 1623 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 1624 // request security level 2 1625 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 1626 channel->required_security_level = LEVEL_2; 1627 gap_request_security_level(channel->con_handle, LEVEL_2); 1628 return; 1629 } 1630 1631 l2cap_ready_to_connect(channel); 1632 } 1633 #endif 1634 1635 #ifdef L2CAP_USES_CHANNELS 1636 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 1637 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 1638 1639 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 1640 if (!channel) { 1641 return NULL; 1642 } 1643 1644 // Init memory (make valgrind happy) 1645 memset(channel, 0, sizeof(l2cap_channel_t)); 1646 1647 // fill in 1648 channel->packet_handler = packet_handler; 1649 bd_addr_copy(channel->address, address); 1650 channel->address_type = address_type; 1651 channel->psm = psm; 1652 channel->local_mtu = local_mtu; 1653 channel->remote_mtu = L2CAP_MINIMAL_MTU; 1654 channel->required_security_level = security_level; 1655 1656 // 1657 channel->local_cid = l2cap_next_local_cid(); 1658 channel->con_handle = 0; 1659 1660 // set initial state 1661 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 1662 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 1663 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 1664 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 1665 1666 return channel; 1667 } 1668 #endif 1669 1670 #ifdef ENABLE_CLASSIC 1671 1672 /** 1673 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 1674 * @param packet_handler 1675 * @param address 1676 * @param psm 1677 * @param mtu 1678 * @param local_cid 1679 */ 1680 1681 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){ 1682 // limit MTU to the size of our outtgoing HCI buffer 1683 uint16_t local_mtu = btstack_min(mtu, l2cap_max_mtu()); 1684 1685 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u -> local mtu %u", bd_addr_to_str(address), psm, mtu, local_mtu); 1686 1687 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 1688 if (!channel) { 1689 return BTSTACK_MEMORY_ALLOC_FAILED; 1690 } 1691 1692 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1693 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1694 #endif 1695 1696 // add to connections list 1697 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1698 1699 // store local_cid 1700 if (out_local_cid){ 1701 *out_local_cid = channel->local_cid; 1702 } 1703 1704 // check if hci connection is already usable 1705 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 1706 if (conn){ 1707 log_info("l2cap_create_channel, hci connection already exists"); 1708 l2cap_handle_connection_complete(conn->con_handle, channel); 1709 // check if remote supported fearures are already received 1710 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 1711 l2cap_handle_remote_supported_features_received(channel); 1712 } 1713 } 1714 1715 l2cap_run(); 1716 1717 return 0; 1718 } 1719 1720 void 1721 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 1722 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 1723 // find channel for local_cid 1724 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1725 if (channel) { 1726 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1727 } 1728 // process 1729 l2cap_run(); 1730 } 1731 1732 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 1733 btstack_linked_list_iterator_t it; 1734 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1735 while (btstack_linked_list_iterator_has_next(&it)){ 1736 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1737 if ( bd_addr_cmp( channel->address, address) != 0) continue; 1738 // channel for this address found 1739 switch (channel->state){ 1740 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1741 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1742 // failure, forward error code 1743 l2cap_emit_channel_opened(channel, status); 1744 // discard channel 1745 l2cap_stop_rtx(channel); 1746 btstack_linked_list_iterator_remove(&it); 1747 btstack_memory_l2cap_channel_free(channel); 1748 break; 1749 default: 1750 break; 1751 } 1752 } 1753 } 1754 1755 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1756 btstack_linked_list_iterator_t it; 1757 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1758 while (btstack_linked_list_iterator_has_next(&it)){ 1759 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1760 if ( ! bd_addr_cmp( channel->address, address) ){ 1761 l2cap_handle_connection_complete(handle, channel); 1762 } 1763 } 1764 // process 1765 l2cap_run(); 1766 } 1767 #endif 1768 1769 static void l2cap_notify_channel_can_send(void){ 1770 1771 #ifdef ENABLE_CLASSIC 1772 btstack_linked_list_iterator_t it; 1773 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1774 while (btstack_linked_list_iterator_has_next(&it)){ 1775 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1776 if (!channel->waiting_for_can_send_now) continue; 1777 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1778 channel->waiting_for_can_send_now = 0; 1779 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1780 } 1781 #endif 1782 1783 int i; 1784 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1785 if (!fixed_channels[i].callback) continue; 1786 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1787 int can_send = 0; 1788 if (l2cap_fixed_channel_table_index_is_le(i)){ 1789 #ifdef ENABLE_BLE 1790 can_send = hci_can_send_acl_le_packet_now(); 1791 #endif 1792 } else { 1793 #ifdef ENABLE_CLASSIC 1794 can_send = hci_can_send_acl_classic_packet_now(); 1795 #endif 1796 } 1797 if (!can_send) continue; 1798 fixed_channels[i].waiting_for_can_send_now = 0; 1799 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1800 } 1801 } 1802 1803 #ifdef L2CAP_USES_CHANNELS 1804 1805 static int l2cap_send_open_failed_on_hci_disconnect(l2cap_channel_t * channel){ 1806 // open cannot fail for for incoming connections 1807 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING) return 0; 1808 1809 // check state 1810 switch (channel->state){ 1811 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1812 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1813 case L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES: 1814 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1815 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 1816 case L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES: 1817 case L2CAP_STATE_WAIT_CONNECT_RSP: 1818 case L2CAP_STATE_CONFIG: 1819 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 1820 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 1821 case L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE: 1822 return 1; 1823 1824 case L2CAP_STATE_OPEN: 1825 case L2CAP_STATE_CLOSED: 1826 case L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES: 1827 case L2CAP_STATE_WAIT_DISCONNECT: 1828 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_INSUFFICIENT_SECURITY: 1829 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 1830 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 1831 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1832 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 1833 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 1834 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 1835 case L2CAP_STATE_INVALID: 1836 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1837 return 0; 1838 // no default here, to get a warning about new states 1839 } 1840 // still, the compiler insists on a return value 1841 return 0; 1842 } 1843 1844 static void l2cap_handle_hci_disconnect_event(l2cap_channel_t * channel){ 1845 if (l2cap_send_open_failed_on_hci_disconnect(channel)){ 1846 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_BASEBAND_DISCONNECT); 1847 } else { 1848 l2cap_emit_channel_closed(channel); 1849 } 1850 btstack_memory_l2cap_channel_free(channel); 1851 } 1852 1853 #endif 1854 1855 1856 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1857 1858 UNUSED(packet_type); 1859 UNUSED(cid); 1860 UNUSED(size); 1861 1862 bd_addr_t address; 1863 hci_con_handle_t handle; 1864 int hci_con_used; 1865 btstack_linked_list_iterator_t it; 1866 1867 // avoid unused warnings 1868 UNUSED(address); 1869 UNUSED(hci_con_used); 1870 UNUSED(it); 1871 UNUSED(handle); 1872 1873 switch(hci_event_packet_get_type(packet)){ 1874 1875 // Notify channel packet handler if they can send now 1876 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1877 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1878 l2cap_run(); // try sending signaling packets first 1879 l2cap_notify_channel_can_send(); 1880 break; 1881 1882 case HCI_EVENT_COMMAND_STATUS: 1883 l2cap_run(); // try sending signaling packets first 1884 break; 1885 1886 #ifdef ENABLE_CLASSIC 1887 // handle connection complete events 1888 case HCI_EVENT_CONNECTION_COMPLETE: 1889 reverse_bd_addr(&packet[5], address); 1890 if (packet[2] == 0){ 1891 handle = little_endian_read_16(packet, 3); 1892 l2cap_handle_connection_success_for_addr(address, handle); 1893 } else { 1894 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1895 } 1896 break; 1897 1898 // handle successful create connection cancel command 1899 case HCI_EVENT_COMMAND_COMPLETE: 1900 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1901 if (packet[5] == 0){ 1902 reverse_bd_addr(&packet[6], address); 1903 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1904 l2cap_handle_connection_failed_for_addr(address, 0x16); 1905 } 1906 } 1907 l2cap_run(); // try sending signaling packets first 1908 break; 1909 #endif 1910 1911 #ifdef L2CAP_USES_CHANNELS 1912 // handle disconnection complete events 1913 case HCI_EVENT_DISCONNECTION_COMPLETE: 1914 handle = little_endian_read_16(packet, 3); 1915 // send l2cap open failed or closed events for all channels on this handle and free them 1916 #ifdef ENABLE_CLASSIC 1917 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1918 while (btstack_linked_list_iterator_has_next(&it)){ 1919 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1920 if (channel->con_handle != handle) continue; 1921 btstack_linked_list_iterator_remove(&it); 1922 l2cap_stop_rtx(channel); 1923 l2cap_handle_hci_disconnect_event(channel); 1924 } 1925 #endif 1926 #ifdef ENABLE_LE_DATA_CHANNELS 1927 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1928 while (btstack_linked_list_iterator_has_next(&it)){ 1929 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1930 if (channel->con_handle != handle) continue; 1931 btstack_linked_list_iterator_remove(&it); 1932 l2cap_handle_hci_disconnect_event(channel); 1933 } 1934 #endif 1935 break; 1936 #endif 1937 1938 // HCI Connection Timeouts 1939 #ifdef ENABLE_CLASSIC 1940 case L2CAP_EVENT_TIMEOUT_CHECK: 1941 handle = little_endian_read_16(packet, 2); 1942 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1943 if (hci_authentication_active_for_handle(handle)) break; 1944 hci_con_used = 0; 1945 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1946 while (btstack_linked_list_iterator_has_next(&it)){ 1947 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1948 if (channel->con_handle != handle) continue; 1949 hci_con_used = 1; 1950 break; 1951 } 1952 if (hci_con_used) break; 1953 if (!hci_can_send_command_packet_now()) break; 1954 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1955 break; 1956 1957 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1958 handle = little_endian_read_16(packet, 3); 1959 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1960 while (btstack_linked_list_iterator_has_next(&it)){ 1961 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1962 if (channel->con_handle != handle) continue; 1963 l2cap_handle_remote_supported_features_received(channel); 1964 break; 1965 } 1966 break; 1967 1968 case GAP_EVENT_SECURITY_LEVEL: 1969 handle = little_endian_read_16(packet, 2); 1970 log_info("l2cap - security level update"); 1971 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1972 while (btstack_linked_list_iterator_has_next(&it)){ 1973 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1974 if (channel->con_handle != handle) continue; 1975 1976 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1977 gap_security_level_t required_level = channel->required_security_level; 1978 1979 log_info("channel state %u: actual %u >= required %u?", channel->state, actual_level, required_level); 1980 1981 switch (channel->state){ 1982 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1983 if (actual_level >= required_level){ 1984 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1985 // we need to know if ERTM is supported before sending a config response 1986 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1987 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 1988 channel->state = L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES; 1989 #else 1990 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1991 l2cap_emit_incoming_connection(channel); 1992 #endif 1993 } else { 1994 channel->reason = 0x0003; // security block 1995 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1996 } 1997 break; 1998 1999 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 2000 if (actual_level >= required_level){ 2001 l2cap_ready_to_connect(channel); 2002 } else { 2003 // disconnnect, authentication not good enough 2004 hci_disconnect_security_block(handle); 2005 } 2006 break; 2007 2008 default: 2009 break; 2010 } 2011 } 2012 break; 2013 #endif 2014 2015 default: 2016 break; 2017 } 2018 2019 l2cap_run(); 2020 } 2021 2022 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t cid, uint16_t data){ 2023 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 2024 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 2025 signaling_responses[signaling_responses_pending].handle = handle; 2026 signaling_responses[signaling_responses_pending].code = code; 2027 signaling_responses[signaling_responses_pending].sig_id = sig_id; 2028 signaling_responses[signaling_responses_pending].cid = cid; 2029 signaling_responses[signaling_responses_pending].data = data; 2030 signaling_responses_pending++; 2031 l2cap_run(); 2032 } 2033 } 2034 2035 #ifdef ENABLE_CLASSIC 2036 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 2037 channel->remote_sig_id = identifier; 2038 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 2039 l2cap_run(); 2040 } 2041 2042 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 2043 2044 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 2045 l2cap_service_t *service = l2cap_get_service(psm); 2046 if (!service) { 2047 // 0x0002 PSM not supported 2048 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 2049 return; 2050 } 2051 2052 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 2053 if (!hci_connection) { 2054 // 2055 log_error("no hci_connection for handle %u", handle); 2056 return; 2057 } 2058 2059 // alloc structure 2060 // log_info("l2cap_handle_connection_request register channel"); 2061 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 2062 psm, service->mtu, service->required_security_level); 2063 if (!channel){ 2064 // 0x0004 No resources available 2065 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 2066 return; 2067 } 2068 2069 channel->con_handle = handle; 2070 channel->remote_cid = source_cid; 2071 channel->remote_sig_id = sig_id; 2072 2073 // limit local mtu to max acl packet length - l2cap header 2074 if (channel->local_mtu > l2cap_max_mtu()) { 2075 channel->local_mtu = l2cap_max_mtu(); 2076 } 2077 2078 // set initial state 2079 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 2080 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND | L2CAP_CHANNEL_STATE_VAR_INCOMING); 2081 2082 // add to connections list 2083 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 2084 2085 // assert security requirements 2086 gap_request_security_level(handle, channel->required_security_level); 2087 } 2088 2089 void l2cap_accept_connection(uint16_t local_cid){ 2090 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 2091 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 2092 if (!channel) { 2093 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 2094 return; 2095 } 2096 2097 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2098 // configure L2CAP Basic mode 2099 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2100 #endif 2101 2102 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 2103 2104 // process 2105 l2cap_run(); 2106 } 2107 2108 void l2cap_decline_connection(uint16_t local_cid){ 2109 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 2110 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 2111 if (!channel) { 2112 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 2113 return; 2114 } 2115 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 2116 channel->reason = 0x04; // no resources available 2117 l2cap_run(); 2118 } 2119 2120 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 2121 2122 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2123 2124 uint16_t flags = little_endian_read_16(command, 6); 2125 if (flags & 1) { 2126 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 2127 } 2128 2129 // accept the other's configuration options 2130 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2131 uint16_t pos = 8; 2132 while (pos < end_pos){ 2133 uint8_t option_hint = command[pos] >> 7; 2134 uint8_t option_type = command[pos] & 0x7f; 2135 // log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 2136 pos++; 2137 uint8_t length = command[pos++]; 2138 // MTU { type(8): 1, len(8):2, MTU(16) } 2139 if (option_type == L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT && length == 2){ 2140 channel->remote_mtu = little_endian_read_16(command, pos); 2141 log_info("Remote MTU %u", channel->remote_mtu); 2142 if (channel->remote_mtu > l2cap_max_mtu()){ 2143 log_info("Remote MTU %u larger than outgoing buffer, only using MTU = %u", channel->remote_mtu, l2cap_max_mtu()); 2144 channel->remote_mtu = l2cap_max_mtu(); 2145 } 2146 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 2147 } 2148 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 2149 if (option_type == L2CAP_CONFIG_OPTION_TYPE_FLUSH_TIMEOUT && length == 2){ 2150 channel->flush_timeout = little_endian_read_16(command, pos); 2151 log_info("Flush timeout: %u ms", channel->flush_timeout); 2152 } 2153 2154 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2155 // Retransmission and Flow Control Option 2156 if (option_type == L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL && length == 9){ 2157 l2cap_channel_mode_t mode = (l2cap_channel_mode_t) command[pos]; 2158 switch(channel->mode){ 2159 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 2160 // Store remote config 2161 channel->remote_tx_window_size = command[pos+1]; 2162 channel->remote_max_transmit = command[pos+2]; 2163 channel->remote_retransmission_timeout_ms = little_endian_read_16(command, pos + 3); 2164 channel->remote_monitor_timeout_ms = little_endian_read_16(command, pos + 5); 2165 channel->remote_mps = little_endian_read_16(command, pos + 7); 2166 log_info("FC&C config: tx window: %u, max transmit %u, retrans timeout %u, monitor timeout %u, mps %u", 2167 channel->remote_tx_window_size, 2168 channel->remote_max_transmit, 2169 channel->remote_retransmission_timeout_ms, 2170 channel->remote_monitor_timeout_ms, 2171 channel->remote_mps); 2172 // If ERTM mandatory, but remote doens't offer ERTM -> disconnect 2173 if (channel->ertm_mandatory && mode != L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 2174 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2175 } else { 2176 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 2177 } 2178 break; 2179 case L2CAP_CHANNEL_MODE_BASIC: 2180 switch (mode){ 2181 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 2182 // remote asks for ERTM, but we want basic mode. disconnect if this happens a second time 2183 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED){ 2184 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2185 } 2186 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED); 2187 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 2188 break; 2189 default: // case L2CAP_CHANNEL_MODE_BASIC: 2190 // TODO store and evaluate configuration 2191 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 2192 break; 2193 } 2194 break; 2195 default: 2196 break; 2197 } 2198 } 2199 #endif 2200 // check for unknown options 2201 if (option_hint == 0 && (option_type < L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT || option_type > L2CAP_CONFIG_OPTION_TYPE_EXTENDED_WINDOW_SIZE)){ 2202 log_info("l2cap cid %u, unknown options", channel->local_cid); 2203 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 2204 } 2205 pos += length; 2206 } 2207 } 2208 2209 static void l2cap_signaling_handle_configure_response(l2cap_channel_t *channel, uint8_t result, uint8_t *command){ 2210 log_info("l2cap_signaling_handle_configure_response"); 2211 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2212 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2213 uint16_t pos = 10; 2214 while (pos < end_pos){ 2215 uint8_t option_hint = command[pos] >> 7; 2216 uint8_t option_type = command[pos] & 0x7f; 2217 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 2218 pos++; 2219 uint8_t length = command[pos++]; 2220 2221 // Retransmission and Flow Control Option 2222 if (option_type == L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL && length == 9){ 2223 switch (channel->mode){ 2224 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 2225 if (channel->ertm_mandatory){ 2226 // ?? 2227 } else { 2228 // On 'Reject - Unacceptable Parameters' to our optional ERTM request, fall back to BASIC mode 2229 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 2230 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2231 } 2232 } 2233 break; 2234 case L2CAP_CHANNEL_MODE_BASIC: 2235 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 2236 // On 'Reject - Unacceptable Parameters' to our Basic mode request, disconnect 2237 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2238 } 2239 break; 2240 default: 2241 break; 2242 } 2243 } 2244 2245 // check for unknown options 2246 if (option_hint == 0 && (option_type < L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT || option_type > L2CAP_CONFIG_OPTION_TYPE_EXTENDED_WINDOW_SIZE)){ 2247 log_info("l2cap cid %u, unknown options", channel->local_cid); 2248 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 2249 } 2250 2251 pos += length; 2252 } 2253 #else 2254 UNUSED(channel); 2255 UNUSED(result); 2256 UNUSED(command); 2257 #endif 2258 } 2259 2260 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 2261 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 2262 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 2263 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 2264 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 2265 if (channel->state == L2CAP_STATE_OPEN) return 0; 2266 return 1; 2267 } 2268 2269 2270 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 2271 2272 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2273 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2274 uint16_t result = 0; 2275 2276 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 2277 2278 // handle DISCONNECT REQUESTS seperately 2279 if (code == DISCONNECTION_REQUEST){ 2280 switch (channel->state){ 2281 case L2CAP_STATE_CONFIG: 2282 case L2CAP_STATE_OPEN: 2283 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 2284 case L2CAP_STATE_WAIT_DISCONNECT: 2285 l2cap_handle_disconnect_request(channel, identifier); 2286 break; 2287 2288 default: 2289 // ignore in other states 2290 break; 2291 } 2292 return; 2293 } 2294 2295 // @STATEMACHINE(l2cap) 2296 switch (channel->state) { 2297 2298 case L2CAP_STATE_WAIT_CONNECT_RSP: 2299 switch (code){ 2300 case CONNECTION_RESPONSE: 2301 l2cap_stop_rtx(channel); 2302 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2303 switch (result) { 2304 case 0: 2305 // successful connection 2306 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2307 channel->state = L2CAP_STATE_CONFIG; 2308 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 2309 break; 2310 case 1: 2311 // connection pending. get some coffee, but start the ERTX 2312 l2cap_start_ertx(channel); 2313 break; 2314 default: 2315 // channel closed 2316 channel->state = L2CAP_STATE_CLOSED; 2317 // map l2cap connection response result to BTstack status enumeration 2318 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 2319 2320 // drop link key if security block 2321 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 2322 gap_drop_link_key_for_bd_addr(channel->address); 2323 } 2324 2325 // discard channel 2326 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2327 btstack_memory_l2cap_channel_free(channel); 2328 break; 2329 } 2330 break; 2331 2332 default: 2333 //@TODO: implement other signaling packets 2334 break; 2335 } 2336 break; 2337 2338 case L2CAP_STATE_CONFIG: 2339 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2340 switch (code) { 2341 case CONFIGURE_REQUEST: 2342 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 2343 l2cap_signaling_handle_configure_request(channel, command); 2344 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 2345 // only done if continuation not set 2346 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 2347 } 2348 break; 2349 case CONFIGURE_RESPONSE: 2350 l2cap_stop_rtx(channel); 2351 l2cap_signaling_handle_configure_response(channel, result, command); 2352 switch (result){ 2353 case 0: // success 2354 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 2355 break; 2356 case 4: // pending 2357 l2cap_start_ertx(channel); 2358 break; 2359 default: 2360 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2361 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION && channel->ertm_mandatory){ 2362 // remote does not offer ertm but it's required 2363 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2364 break; 2365 } 2366 #endif 2367 // retry on negative result 2368 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 2369 break; 2370 } 2371 break; 2372 default: 2373 break; 2374 } 2375 if (l2cap_channel_ready_for_open(channel)){ 2376 // for open: 2377 channel->state = L2CAP_STATE_OPEN; 2378 l2cap_emit_channel_opened(channel, 0); 2379 } 2380 break; 2381 2382 case L2CAP_STATE_WAIT_DISCONNECT: 2383 switch (code) { 2384 case DISCONNECTION_RESPONSE: 2385 l2cap_finialize_channel_close(channel); 2386 break; 2387 default: 2388 //@TODO: implement other signaling packets 2389 break; 2390 } 2391 break; 2392 2393 case L2CAP_STATE_CLOSED: 2394 // @TODO handle incoming requests 2395 break; 2396 2397 case L2CAP_STATE_OPEN: 2398 //@TODO: implement other signaling packets, e.g. re-configure 2399 break; 2400 default: 2401 break; 2402 } 2403 // log_info("new state %u", channel->state); 2404 } 2405 2406 2407 // @pre command len is valid, see check in l2cap_acl_classic_handler 2408 static void l2cap_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command){ 2409 2410 btstack_linked_list_iterator_t it; 2411 2412 // get code, signalind identifier and command len 2413 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2414 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2415 2416 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_RESPONSE 2417 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_RESPONSE){ 2418 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2419 return; 2420 } 2421 2422 // general commands without an assigned channel 2423 switch(code) { 2424 2425 case CONNECTION_REQUEST: { 2426 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2427 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2428 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 2429 return; 2430 } 2431 2432 case ECHO_REQUEST: 2433 l2cap_register_signaling_response(handle, code, sig_id, 0, 0); 2434 return; 2435 2436 case INFORMATION_REQUEST: { 2437 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2438 l2cap_register_signaling_response(handle, code, sig_id, 0, info_type); 2439 return; 2440 } 2441 2442 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2443 case INFORMATION_RESPONSE: { 2444 hci_connection_t * connection = hci_connection_for_handle(handle); 2445 if (!connection) return; 2446 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2447 uint16_t result = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2448 if (result != 0) return; 2449 if (info_type != L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED) return; 2450 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_DONE; 2451 connection->l2cap_state.extended_feature_mask = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2452 log_info("extended features mask 0x%02x", connection->l2cap_state.extended_feature_mask); 2453 // trigger connection request 2454 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2455 while (btstack_linked_list_iterator_has_next(&it)){ 2456 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2457 if (channel->con_handle != handle) continue; 2458 // bail if ERTM was requested but is not supported 2459 if ((channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION) && ((connection->l2cap_state.extended_feature_mask & 0x08) == 0)){ 2460 if (channel->ertm_mandatory){ 2461 // channel closed 2462 channel->state = L2CAP_STATE_CLOSED; 2463 // map l2cap connection response result to BTstack status enumeration 2464 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_ERTM_NOT_SUPPORTED); 2465 // discard channel 2466 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2467 btstack_memory_l2cap_channel_free(channel); 2468 continue; 2469 } else { 2470 // fallback to Basic mode 2471 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2472 } 2473 } 2474 // start connecting 2475 if (channel->state == L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES){ 2476 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 2477 } 2478 // respond to connection request 2479 if (channel->state == L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES){ 2480 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2481 l2cap_emit_incoming_connection(channel); 2482 } 2483 } 2484 return; 2485 } 2486 #endif 2487 2488 default: 2489 break; 2490 } 2491 2492 2493 // Get potential destination CID 2494 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2495 2496 // Find channel for this sig_id and connection handle 2497 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2498 while (btstack_linked_list_iterator_has_next(&it)){ 2499 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2500 if (channel->con_handle != handle) continue; 2501 if (code & 1) { 2502 // match odd commands (responses) by previous signaling identifier 2503 if (channel->local_sig_id == sig_id) { 2504 l2cap_signaling_handler_channel(channel, command); 2505 break; 2506 } 2507 } else { 2508 // match even commands (requests) by local channel id 2509 if (channel->local_cid == dest_cid) { 2510 l2cap_signaling_handler_channel(channel, command); 2511 break; 2512 } 2513 } 2514 } 2515 } 2516 #endif 2517 2518 #ifdef ENABLE_BLE 2519 2520 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 2521 uint8_t event[6]; 2522 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 2523 event[1] = 4; 2524 little_endian_store_16(event, 2, con_handle); 2525 little_endian_store_16(event, 4, result); 2526 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2527 if (!l2cap_event_packet_handler) return; 2528 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 2529 } 2530 2531 // @returns valid 2532 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 2533 hci_connection_t * connection; 2534 uint16_t result; 2535 uint8_t event[10]; 2536 2537 #ifdef ENABLE_LE_DATA_CHANNELS 2538 btstack_linked_list_iterator_t it; 2539 l2cap_channel_t * channel; 2540 uint16_t local_cid; 2541 uint16_t le_psm; 2542 uint16_t new_credits; 2543 uint16_t credits_before; 2544 l2cap_service_t * service; 2545 uint16_t source_cid; 2546 #endif 2547 2548 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2549 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 2550 2551 switch (code){ 2552 2553 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 2554 result = little_endian_read_16(command, 4); 2555 l2cap_emit_connection_parameter_update_response(handle, result); 2556 break; 2557 2558 case CONNECTION_PARAMETER_UPDATE_REQUEST: 2559 connection = hci_connection_for_handle(handle); 2560 if (connection){ 2561 if (connection->role != HCI_ROLE_MASTER){ 2562 // reject command without notifying upper layer when not in master role 2563 return 0; 2564 } 2565 int update_parameter = 1; 2566 le_connection_parameter_range_t existing_range; 2567 gap_get_connection_parameter_range(&existing_range); 2568 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 2569 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 2570 uint16_t le_conn_latency = little_endian_read_16(command,12); 2571 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 2572 2573 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 2574 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 2575 2576 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 2577 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 2578 2579 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 2580 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 2581 2582 if (update_parameter){ 2583 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 2584 connection->le_conn_interval_min = le_conn_interval_min; 2585 connection->le_conn_interval_max = le_conn_interval_max; 2586 connection->le_conn_latency = le_conn_latency; 2587 connection->le_supervision_timeout = le_supervision_timeout; 2588 } else { 2589 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 2590 } 2591 connection->le_con_param_update_identifier = sig_id; 2592 } 2593 2594 if (!l2cap_event_packet_handler) break; 2595 2596 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 2597 event[1] = 8; 2598 memcpy(&event[2], &command[4], 8); 2599 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2600 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2601 break; 2602 2603 #ifdef ENABLE_LE_DATA_CHANNELS 2604 2605 case COMMAND_REJECT: 2606 // Find channel for this sig_id and connection handle 2607 channel = NULL; 2608 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2609 while (btstack_linked_list_iterator_has_next(&it)){ 2610 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2611 if (a_channel->con_handle != handle) continue; 2612 if (a_channel->local_sig_id != sig_id) continue; 2613 channel = a_channel; 2614 break; 2615 } 2616 if (!channel) break; 2617 2618 // if received while waiting for le connection response, assume legacy device 2619 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 2620 channel->state = L2CAP_STATE_CLOSED; 2621 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 2622 l2cap_emit_le_channel_opened(channel, 0x0002); 2623 2624 // discard channel 2625 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2626 btstack_memory_l2cap_channel_free(channel); 2627 break; 2628 } 2629 break; 2630 2631 case LE_CREDIT_BASED_CONNECTION_REQUEST: 2632 2633 // get hci connection, bail if not found (must not happen) 2634 connection = hci_connection_for_handle(handle); 2635 if (!connection) return 0; 2636 2637 // check if service registered 2638 le_psm = little_endian_read_16(command, 4); 2639 service = l2cap_le_get_service(le_psm); 2640 source_cid = little_endian_read_16(command, 6); 2641 2642 if (service){ 2643 if (source_cid < 0x40){ 2644 // 0x0009 Connection refused - Invalid Source CID 2645 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0009); 2646 return 1; 2647 } 2648 2649 // go through list of channels for this ACL connection and check if we get a match 2650 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2651 while (btstack_linked_list_iterator_has_next(&it)){ 2652 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2653 if (a_channel->con_handle != handle) continue; 2654 if (a_channel->remote_cid != source_cid) continue; 2655 // 0x000a Connection refused - Source CID already allocated 2656 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x000a); 2657 return 1; 2658 } 2659 2660 // security: check encryption 2661 if (service->required_security_level >= LEVEL_2){ 2662 if (sm_encryption_key_size(handle) == 0){ 2663 // 0x0008 Connection refused - insufficient encryption 2664 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0008); 2665 return 1; 2666 } 2667 // anything less than 16 byte key size is insufficient 2668 if (sm_encryption_key_size(handle) < 16){ 2669 // 0x0007 Connection refused – insufficient encryption key size 2670 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0007); 2671 return 1; 2672 } 2673 } 2674 2675 // security: check authencation 2676 if (service->required_security_level >= LEVEL_3){ 2677 if (!sm_authenticated(handle)){ 2678 // 0x0005 Connection refused – insufficient authentication 2679 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0005); 2680 return 1; 2681 } 2682 } 2683 2684 // security: check authorization 2685 if (service->required_security_level >= LEVEL_4){ 2686 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 2687 // 0x0006 Connection refused – insufficient authorization 2688 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0006); 2689 return 1; 2690 } 2691 } 2692 2693 // allocate channel 2694 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 2695 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 2696 if (!channel){ 2697 // 0x0004 Connection refused – no resources available 2698 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 2699 return 1; 2700 } 2701 2702 channel->con_handle = handle; 2703 channel->remote_cid = source_cid; 2704 channel->remote_sig_id = sig_id; 2705 channel->remote_mtu = little_endian_read_16(command, 8); 2706 channel->remote_mps = little_endian_read_16(command, 10); 2707 channel->credits_outgoing = little_endian_read_16(command, 12); 2708 2709 // set initial state 2710 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2711 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 2712 2713 // add to connections list 2714 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2715 2716 // post connection request event 2717 l2cap_emit_le_incoming_connection(channel); 2718 2719 } else { 2720 // Connection refused – LE_PSM not supported 2721 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 2722 } 2723 break; 2724 2725 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 2726 // Find channel for this sig_id and connection handle 2727 channel = NULL; 2728 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2729 while (btstack_linked_list_iterator_has_next(&it)){ 2730 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2731 if (a_channel->con_handle != handle) continue; 2732 if (a_channel->local_sig_id != sig_id) continue; 2733 channel = a_channel; 2734 break; 2735 } 2736 if (!channel) break; 2737 2738 // cid + 0 2739 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 2740 if (result){ 2741 channel->state = L2CAP_STATE_CLOSED; 2742 // map l2cap connection response result to BTstack status enumeration 2743 l2cap_emit_le_channel_opened(channel, result); 2744 2745 // discard channel 2746 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2747 btstack_memory_l2cap_channel_free(channel); 2748 break; 2749 } 2750 2751 // success 2752 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2753 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2754 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 2755 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 2756 channel->state = L2CAP_STATE_OPEN; 2757 l2cap_emit_le_channel_opened(channel, result); 2758 break; 2759 2760 case LE_FLOW_CONTROL_CREDIT: 2761 // find channel 2762 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2763 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2764 if (!channel) { 2765 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2766 break; 2767 } 2768 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2769 credits_before = channel->credits_outgoing; 2770 channel->credits_outgoing += new_credits; 2771 // check for credit overrun 2772 if (credits_before > channel->credits_outgoing){ 2773 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 2774 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2775 break; 2776 } 2777 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 2778 break; 2779 2780 case DISCONNECTION_REQUEST: 2781 // find channel 2782 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2783 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2784 if (!channel) { 2785 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2786 break; 2787 } 2788 channel->remote_sig_id = sig_id; 2789 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 2790 break; 2791 2792 #endif 2793 2794 case DISCONNECTION_RESPONSE: 2795 break; 2796 2797 default: 2798 // command unknown -> reject command 2799 return 0; 2800 } 2801 return 1; 2802 } 2803 #endif 2804 2805 static void l2cap_acl_classic_handler(hci_con_handle_t handle, uint8_t *packet, uint16_t size){ 2806 #ifdef ENABLE_CLASSIC 2807 l2cap_channel_t * l2cap_channel; 2808 2809 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 2810 switch (channel_id) { 2811 2812 case L2CAP_CID_SIGNALING: { 2813 uint16_t command_offset = 8; 2814 while (command_offset < size) { 2815 // assert signaling command is fully inside packet 2816 uint16_t data_len = little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2817 uint32_t next_command_offset = ((uint32_t) command_offset) + L2CAP_SIGNALING_COMMAND_DATA_OFFSET + data_len; 2818 if (next_command_offset > size){ 2819 log_error("l2cap signaling command len invalid -> drop"); 2820 break; 2821 } 2822 // handle signaling command 2823 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 2824 // go to next command 2825 command_offset = (uint16_t) next_command_offset; 2826 } 2827 break; 2828 } 2829 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 2830 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 2831 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2832 } 2833 break; 2834 2835 default: 2836 // Find channel for this channel_id and connection handle 2837 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 2838 if (l2cap_channel) { 2839 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2840 if (l2cap_channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 2841 2842 // verify FCS 2843 uint16_t fcs_calculated = crc16_calc(&packet[4], size - (4+2)); 2844 uint16_t fcs_packet = little_endian_read_16(packet, size-2); 2845 log_info("Packet FCS 0x%04x, calculated FCS 0x%04x", fcs_packet, fcs_calculated); 2846 if (fcs_calculated != fcs_packet){ 2847 log_error("FCS mismatch! Packet 0x%04x, calculated 0x%04x", fcs_packet, fcs_calculated); 2848 // TODO: trigger retransmission or something like that 2849 break; 2850 } 2851 2852 // switch on packet type 2853 uint16_t control = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 2854 uint8_t req_seq = (control >> 8) & 0x3f; 2855 int final = (control >> 7) & 0x01; 2856 if (control & 1){ 2857 // S-Frame 2858 int poll = (control >> 4) & 0x01; 2859 l2cap_supervisory_function_t s = (l2cap_supervisory_function_t) ((control >> 2) & 0x03); 2860 log_info("Control: 0x%04x => Supervisory function %u, ReqSeq %02u", control, (int) s, req_seq); 2861 l2cap_ertm_tx_packet_state_t * tx_state; 2862 switch (s){ 2863 case L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY: 2864 log_info("L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY"); 2865 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 2866 if (poll && final){ 2867 // S-frames shall not be transmitted with both the F-bit and the P-bit set to 1 at the same time. 2868 log_error("P=F=1 in S-Frame"); 2869 break; 2870 } 2871 if (poll){ 2872 // check if we did request selective retransmission before <==> we have stored SDU segments 2873 int i; 2874 int num_stored_out_of_order_packets = 0; 2875 for (i=0;i<l2cap_channel->num_rx_buffers;i++){ 2876 int index = l2cap_channel->rx_store_index + i; 2877 if (index >= l2cap_channel->num_rx_buffers){ 2878 index -= l2cap_channel->num_rx_buffers; 2879 } 2880 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 2881 if (!rx_state->valid) continue; 2882 num_stored_out_of_order_packets++; 2883 } 2884 if (num_stored_out_of_order_packets){ 2885 l2cap_channel->send_supervisor_frame_selective_reject = 1; 2886 } else { 2887 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 2888 } 2889 l2cap_channel->set_final_bit_after_packet_with_poll_bit_set = 1; 2890 } 2891 if (final){ 2892 // Stop-MonitorTimer 2893 l2cap_ertm_stop_monitor_timer(l2cap_channel); 2894 // If UnackedFrames > 0 then Start-RetransTimer 2895 if (l2cap_channel->unacked_frames){ 2896 l2cap_ertm_start_retransmission_timer(l2cap_channel); 2897 } 2898 2899 // final bit set <- response to RR with poll bit set. All not acknowledged packets need to be retransmitted 2900 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 2901 } 2902 break; 2903 case L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT: 2904 log_info("L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT"); 2905 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 2906 // rsetart transmittion from last unacknowledted packet (earlier packets already freed in l2cap_ertm_process_req_seq) 2907 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 2908 break; 2909 case L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY: 2910 log_error("L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY"); 2911 break; 2912 case L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT: 2913 log_info("L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT"); 2914 if (poll){ 2915 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 2916 } 2917 // find requested i-frame 2918 tx_state = l2cap_ertm_get_tx_state(l2cap_channel, req_seq); 2919 if (tx_state){ 2920 log_info("Retransmission for tx_seq %u requested", req_seq); 2921 l2cap_channel->set_final_bit_after_packet_with_poll_bit_set = poll; 2922 tx_state->retransmission_requested = 1; 2923 l2cap_channel->srej_active = 1; 2924 } 2925 break; 2926 default: 2927 break; 2928 } 2929 break; 2930 } else { 2931 // I-Frame 2932 // get control 2933 l2cap_segmentation_and_reassembly_t sar = (l2cap_segmentation_and_reassembly_t) (control >> 14); 2934 uint8_t tx_seq = (control >> 1) & 0x3f; 2935 log_info("Control: 0x%04x => SAR %u, ReqSeq %02u, R?, TxSeq %02u", control, (int) sar, req_seq, tx_seq); 2936 log_info("SAR: pos %u", l2cap_channel->reassembly_pos); 2937 log_info("State: expected_tx_seq %02u, req_seq %02u", l2cap_channel->expected_tx_seq, l2cap_channel->req_seq); 2938 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 2939 if (final){ 2940 // final bit set <- response to RR with poll bit set. All not acknowledged packets need to be retransmitted 2941 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 2942 } 2943 // check ordering 2944 if (l2cap_channel->expected_tx_seq == tx_seq){ 2945 log_info("Received expected frame with TxSeq == ExpectedTxSeq == %02u", tx_seq); 2946 l2cap_channel->expected_tx_seq = l2cap_next_ertm_seq_nr(l2cap_channel->expected_tx_seq); 2947 l2cap_channel->req_seq = l2cap_channel->expected_tx_seq; 2948 2949 // process SDU 2950 l2cap_ertm_handle_in_sequence_sdu(l2cap_channel, sar, &packet[COMPLETE_L2CAP_HEADER+2], size-(COMPLETE_L2CAP_HEADER+2+2)); 2951 2952 // process stored segments 2953 while (1){ 2954 int index = l2cap_channel->rx_store_index; 2955 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 2956 if (!rx_state->valid) break; 2957 2958 log_info("Processing stored frame with TxSeq == ExpectedTxSeq == %02u", l2cap_channel->expected_tx_seq); 2959 l2cap_channel->expected_tx_seq = l2cap_next_ertm_seq_nr(l2cap_channel->expected_tx_seq); 2960 l2cap_channel->req_seq = l2cap_channel->expected_tx_seq; 2961 2962 rx_state->valid = 0; 2963 l2cap_ertm_handle_in_sequence_sdu(l2cap_channel, rx_state->sar, &l2cap_channel->rx_packets_data[index], rx_state->len); 2964 2965 // update rx store index 2966 index++; 2967 if (index >= l2cap_channel->num_rx_buffers){ 2968 index = 0; 2969 } 2970 l2cap_channel->rx_store_index = index; 2971 } 2972 2973 // 2974 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 2975 2976 } else { 2977 int delta = (tx_seq - l2cap_channel->expected_tx_seq) & 0x3f; 2978 if (delta < 2){ 2979 // store segment 2980 l2cap_ertm_handle_out_of_sequence_sdu(l2cap_channel, sar, delta, &packet[COMPLETE_L2CAP_HEADER+2], size-(COMPLETE_L2CAP_HEADER+2+2)); 2981 2982 log_info("Received unexpected frame TxSeq %u but expected %u -> send S-SREJ", tx_seq, l2cap_channel->expected_tx_seq); 2983 l2cap_channel->send_supervisor_frame_selective_reject = 1; 2984 } else { 2985 log_info("Received unexpected frame TxSeq %u but expected %u -> send S-REJ", tx_seq, l2cap_channel->expected_tx_seq); 2986 l2cap_channel->send_supervisor_frame_reject = 1; 2987 } 2988 } 2989 } 2990 break; 2991 } 2992 #endif 2993 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2994 } 2995 break; 2996 } 2997 #else 2998 UNUSED(handle); // ok: no code 2999 UNUSED(packet); // ok: no code 3000 UNUSED(size); // ok: no code 3001 #endif 3002 } 3003 3004 static void l2cap_acl_le_handler(hci_con_handle_t handle, uint8_t *packet, uint16_t size ){ 3005 #ifdef ENABLE_BLE 3006 3007 #ifdef ENABLE_LE_DATA_CHANNELS 3008 l2cap_channel_t * l2cap_channel; 3009 #endif 3010 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 3011 switch (channel_id) { 3012 3013 case L2CAP_CID_SIGNALING_LE: { 3014 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 3015 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 3016 if (!valid){ 3017 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 3018 } 3019 break; 3020 } 3021 3022 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 3023 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 3024 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 3025 } 3026 break; 3027 3028 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 3029 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 3030 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 3031 } 3032 break; 3033 3034 default: 3035 3036 #ifdef ENABLE_LE_DATA_CHANNELS 3037 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 3038 if (l2cap_channel) { 3039 // credit counting 3040 if (l2cap_channel->credits_incoming == 0){ 3041 log_error("LE Data Channel packet received but no incoming credits"); 3042 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3043 break; 3044 } 3045 l2cap_channel->credits_incoming--; 3046 3047 // automatic credits 3048 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 3049 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 3050 } 3051 3052 // first fragment 3053 uint16_t pos = 0; 3054 if (!l2cap_channel->receive_sdu_len){ 3055 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 3056 l2cap_channel->receive_sdu_pos = 0; 3057 pos += 2; 3058 size -= 2; 3059 } 3060 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 3061 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 3062 // done? 3063 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 3064 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 3065 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 3066 l2cap_channel->receive_sdu_len = 0; 3067 } 3068 } else { 3069 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 3070 } 3071 #endif 3072 break; 3073 } 3074 #else 3075 UNUSED(handle); // ok: no code 3076 UNUSED(packet); // ok: no code 3077 UNUSED(size); // ok: no code 3078 #endif 3079 } 3080 3081 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3082 UNUSED(packet_type); // ok: registered with hci_register_acl_packet_handler 3083 UNUSED(channel); // ok: there is no channel 3084 3085 // Dispatch to Classic or LE handler 3086 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 3087 hci_connection_t *conn = hci_connection_for_handle(handle); 3088 if (!conn) return; 3089 if (conn->address_type == BD_ADDR_TYPE_CLASSIC){ 3090 l2cap_acl_classic_handler(handle, packet, size); 3091 } else { 3092 l2cap_acl_le_handler(handle, packet, size); 3093 } 3094 3095 l2cap_run(); 3096 } 3097 3098 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 3099 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 3100 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 3101 if (index < 0) return; 3102 fixed_channels[index].callback = the_packet_handler; 3103 } 3104 3105 #ifdef ENABLE_CLASSIC 3106 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 3107 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 3108 channel->state = L2CAP_STATE_CLOSED; 3109 l2cap_emit_channel_closed(channel); 3110 // discard channel 3111 l2cap_stop_rtx(channel); 3112 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 3113 btstack_memory_l2cap_channel_free(channel); 3114 } 3115 3116 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 3117 btstack_linked_list_iterator_t it; 3118 btstack_linked_list_iterator_init(&it, services); 3119 while (btstack_linked_list_iterator_has_next(&it)){ 3120 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 3121 if ( service->psm == psm){ 3122 return service; 3123 }; 3124 } 3125 return NULL; 3126 } 3127 3128 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 3129 return l2cap_get_service_internal(&l2cap_services, psm); 3130 } 3131 3132 3133 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 3134 3135 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 3136 3137 // check for alread registered psm 3138 l2cap_service_t *service = l2cap_get_service(psm); 3139 if (service) { 3140 log_error("l2cap_register_service: PSM %u already registered", psm); 3141 return L2CAP_SERVICE_ALREADY_REGISTERED; 3142 } 3143 3144 // alloc structure 3145 service = btstack_memory_l2cap_service_get(); 3146 if (!service) { 3147 log_error("l2cap_register_service: no memory for l2cap_service_t"); 3148 return BTSTACK_MEMORY_ALLOC_FAILED; 3149 } 3150 3151 // fill in 3152 service->psm = psm; 3153 service->mtu = mtu; 3154 service->packet_handler = service_packet_handler; 3155 service->required_security_level = security_level; 3156 3157 // add to services list 3158 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 3159 3160 // enable page scan 3161 gap_connectable_control(1); 3162 3163 return 0; 3164 } 3165 3166 uint8_t l2cap_unregister_service(uint16_t psm){ 3167 3168 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 3169 3170 l2cap_service_t *service = l2cap_get_service(psm); 3171 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 3172 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 3173 btstack_memory_l2cap_service_free(service); 3174 3175 // disable page scan when no services registered 3176 if (btstack_linked_list_empty(&l2cap_services)) { 3177 gap_connectable_control(0); 3178 } 3179 return 0; 3180 } 3181 #endif 3182 3183 3184 #ifdef ENABLE_LE_DATA_CHANNELS 3185 3186 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 3187 if (!channel->waiting_for_can_send_now) return; 3188 if (channel->send_sdu_buffer) return; 3189 channel->waiting_for_can_send_now = 0; 3190 log_info("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 3191 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 3192 } 3193 3194 // 1BH2222 3195 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 3196 log_info("L2CAP_EVENT_LE_INCOMING_CONNECTION addr_type %u, addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x, remote_mtu %u", 3197 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 3198 uint8_t event[19]; 3199 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 3200 event[1] = sizeof(event) - 2; 3201 event[2] = channel->address_type; 3202 reverse_bd_addr(channel->address, &event[3]); 3203 little_endian_store_16(event, 9, channel->con_handle); 3204 little_endian_store_16(event, 11, channel->psm); 3205 little_endian_store_16(event, 13, channel->local_cid); 3206 little_endian_store_16(event, 15, channel->remote_cid); 3207 little_endian_store_16(event, 17, channel->remote_mtu); 3208 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 3209 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 3210 } 3211 // 11BH22222 3212 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 3213 log_info("L2CAP_EVENT_LE_CHANNEL_OPENED 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", 3214 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 3215 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 3216 uint8_t event[23]; 3217 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 3218 event[1] = sizeof(event) - 2; 3219 event[2] = status; 3220 event[3] = channel->address_type; 3221 reverse_bd_addr(channel->address, &event[4]); 3222 little_endian_store_16(event, 10, channel->con_handle); 3223 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 3224 little_endian_store_16(event, 13, channel->psm); 3225 little_endian_store_16(event, 15, channel->local_cid); 3226 little_endian_store_16(event, 17, channel->remote_cid); 3227 little_endian_store_16(event, 19, channel->local_mtu); 3228 little_endian_store_16(event, 21, channel->remote_mtu); 3229 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 3230 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 3231 } 3232 3233 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 3234 btstack_linked_list_iterator_t it; 3235 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 3236 while (btstack_linked_list_iterator_has_next(&it)){ 3237 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 3238 if ( channel->local_cid == local_cid) { 3239 return channel; 3240 } 3241 } 3242 return NULL; 3243 } 3244 3245 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 3246 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 3247 channel->state = L2CAP_STATE_CLOSED; 3248 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 3249 // discard channel 3250 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 3251 btstack_memory_l2cap_channel_free(channel); 3252 } 3253 3254 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 3255 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 3256 } 3257 3258 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 3259 3260 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 3261 3262 // check for alread registered psm 3263 l2cap_service_t *service = l2cap_le_get_service(psm); 3264 if (service) { 3265 return L2CAP_SERVICE_ALREADY_REGISTERED; 3266 } 3267 3268 // alloc structure 3269 service = btstack_memory_l2cap_service_get(); 3270 if (!service) { 3271 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 3272 return BTSTACK_MEMORY_ALLOC_FAILED; 3273 } 3274 3275 // fill in 3276 service->psm = psm; 3277 service->mtu = 0; 3278 service->packet_handler = packet_handler; 3279 service->required_security_level = security_level; 3280 3281 // add to services list 3282 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 3283 3284 // done 3285 return 0; 3286 } 3287 3288 uint8_t l2cap_le_unregister_service(uint16_t psm) { 3289 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 3290 l2cap_service_t *service = l2cap_le_get_service(psm); 3291 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 3292 3293 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 3294 btstack_memory_l2cap_service_free(service); 3295 return 0; 3296 } 3297 3298 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 3299 // get channel 3300 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3301 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3302 3303 // validate state 3304 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 3305 return ERROR_CODE_COMMAND_DISALLOWED; 3306 } 3307 3308 // set state accept connection 3309 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 3310 channel->receive_sdu_buffer = receive_sdu_buffer; 3311 channel->local_mtu = mtu; 3312 channel->new_credits_incoming = initial_credits; 3313 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 3314 3315 // test 3316 // channel->new_credits_incoming = 1; 3317 3318 // go 3319 l2cap_run(); 3320 return 0; 3321 } 3322 3323 /** 3324 * @brief Deny incoming LE Data Channel connection due to resource constraints 3325 * @param local_cid L2CAP LE Data Channel Identifier 3326 */ 3327 3328 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 3329 // get channel 3330 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3331 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3332 3333 // validate state 3334 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 3335 return ERROR_CODE_COMMAND_DISALLOWED; 3336 } 3337 3338 // set state decline connection 3339 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 3340 channel->reason = 0x04; // no resources available 3341 l2cap_run(); 3342 return 0; 3343 } 3344 3345 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 3346 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 3347 uint16_t * out_local_cid) { 3348 3349 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 3350 3351 3352 hci_connection_t * connection = hci_connection_for_handle(con_handle); 3353 if (!connection) { 3354 log_error("no hci_connection for handle 0x%04x", con_handle); 3355 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 3356 } 3357 3358 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 3359 if (!channel) { 3360 return BTSTACK_MEMORY_ALLOC_FAILED; 3361 } 3362 log_info("l2cap_le_create_channel %p", channel); 3363 3364 // store local_cid 3365 if (out_local_cid){ 3366 *out_local_cid = channel->local_cid; 3367 } 3368 3369 // provide buffer 3370 channel->con_handle = con_handle; 3371 channel->receive_sdu_buffer = receive_sdu_buffer; 3372 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 3373 channel->new_credits_incoming = initial_credits; 3374 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 3375 3376 // add to connections list 3377 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 3378 3379 // go 3380 l2cap_run(); 3381 return 0; 3382 } 3383 3384 /** 3385 * @brief Provide credtis for LE Data Channel 3386 * @param local_cid L2CAP LE Data Channel Identifier 3387 * @param credits Number additional credits for peer 3388 */ 3389 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 3390 3391 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3392 if (!channel) { 3393 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 3394 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3395 } 3396 3397 // check state 3398 if (channel->state != L2CAP_STATE_OPEN){ 3399 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 3400 } 3401 3402 // assert incoming credits + credits <= 0xffff 3403 uint32_t total_credits = channel->credits_incoming; 3404 total_credits += channel->new_credits_incoming; 3405 total_credits += credits; 3406 if (total_credits > 0xffff){ 3407 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 3408 channel->new_credits_incoming, credits); 3409 } 3410 3411 // set credits_granted 3412 channel->new_credits_incoming += credits; 3413 3414 // go 3415 l2cap_run(); 3416 return 0; 3417 } 3418 3419 /** 3420 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 3421 * @param local_cid L2CAP LE Data Channel Identifier 3422 */ 3423 int l2cap_le_can_send_now(uint16_t local_cid){ 3424 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3425 if (!channel) { 3426 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 3427 return 0; 3428 } 3429 3430 // check state 3431 if (channel->state != L2CAP_STATE_OPEN) return 0; 3432 3433 // check queue 3434 if (channel->send_sdu_buffer) return 0; 3435 3436 // fine, go ahead 3437 return 1; 3438 } 3439 3440 /** 3441 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 3442 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 3443 * so packet handler should be ready to handle it 3444 * @param local_cid L2CAP LE Data Channel Identifier 3445 */ 3446 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 3447 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3448 if (!channel) { 3449 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 3450 return 0; 3451 } 3452 channel->waiting_for_can_send_now = 1; 3453 l2cap_le_notify_channel_can_send(channel); 3454 return 0; 3455 } 3456 3457 /** 3458 * @brief Send data via LE Data Channel 3459 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 3460 * @param local_cid L2CAP LE Data Channel Identifier 3461 * @param data data to send 3462 * @param size data size 3463 */ 3464 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 3465 3466 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3467 if (!channel) { 3468 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 3469 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3470 } 3471 3472 if (len > channel->remote_mtu){ 3473 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 3474 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 3475 } 3476 3477 if (channel->send_sdu_buffer){ 3478 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 3479 return BTSTACK_ACL_BUFFERS_FULL; 3480 } 3481 3482 channel->send_sdu_buffer = data; 3483 channel->send_sdu_len = len; 3484 channel->send_sdu_pos = 0; 3485 3486 l2cap_run(); 3487 return 0; 3488 } 3489 3490 /** 3491 * @brief Disconnect from LE Data Channel 3492 * @param local_cid L2CAP LE Data Channel Identifier 3493 */ 3494 uint8_t l2cap_le_disconnect(uint16_t local_cid) 3495 { 3496 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3497 if (!channel) { 3498 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 3499 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3500 } 3501 3502 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3503 l2cap_run(); 3504 return 0; 3505 } 3506 3507 #endif 3508