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 gap_request_security_level(channel->con_handle, LEVEL_2); 1627 return; 1628 } 1629 1630 l2cap_ready_to_connect(channel); 1631 } 1632 #endif 1633 1634 #ifdef L2CAP_USES_CHANNELS 1635 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 1636 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 1637 1638 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 1639 if (!channel) { 1640 return NULL; 1641 } 1642 1643 // Init memory (make valgrind happy) 1644 memset(channel, 0, sizeof(l2cap_channel_t)); 1645 1646 // fill in 1647 channel->packet_handler = packet_handler; 1648 bd_addr_copy(channel->address, address); 1649 channel->address_type = address_type; 1650 channel->psm = psm; 1651 channel->local_mtu = local_mtu; 1652 channel->remote_mtu = L2CAP_MINIMAL_MTU; 1653 channel->required_security_level = security_level; 1654 1655 // 1656 channel->local_cid = l2cap_next_local_cid(); 1657 channel->con_handle = 0; 1658 1659 // set initial state 1660 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 1661 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 1662 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 1663 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 1664 1665 return channel; 1666 } 1667 #endif 1668 1669 #ifdef ENABLE_CLASSIC 1670 1671 /** 1672 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 1673 * @param packet_handler 1674 * @param address 1675 * @param psm 1676 * @param mtu 1677 * @param local_cid 1678 */ 1679 1680 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){ 1681 // limit MTU to the size of our outtgoing HCI buffer 1682 uint16_t local_mtu = btstack_min(mtu, l2cap_max_mtu()); 1683 1684 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u -> local mtu %u", bd_addr_to_str(address), psm, mtu, local_mtu); 1685 1686 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 1687 if (!channel) { 1688 return BTSTACK_MEMORY_ALLOC_FAILED; 1689 } 1690 1691 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1692 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1693 #endif 1694 1695 // add to connections list 1696 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1697 1698 // store local_cid 1699 if (out_local_cid){ 1700 *out_local_cid = channel->local_cid; 1701 } 1702 1703 // check if hci connection is already usable 1704 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 1705 if (conn){ 1706 log_info("l2cap_create_channel, hci connection already exists"); 1707 l2cap_handle_connection_complete(conn->con_handle, channel); 1708 // check if remote supported fearures are already received 1709 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 1710 l2cap_handle_remote_supported_features_received(channel); 1711 } 1712 } 1713 1714 l2cap_run(); 1715 1716 return 0; 1717 } 1718 1719 void 1720 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 1721 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 1722 // find channel for local_cid 1723 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1724 if (channel) { 1725 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1726 } 1727 // process 1728 l2cap_run(); 1729 } 1730 1731 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 1732 btstack_linked_list_iterator_t it; 1733 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1734 while (btstack_linked_list_iterator_has_next(&it)){ 1735 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1736 if ( bd_addr_cmp( channel->address, address) != 0) continue; 1737 // channel for this address found 1738 switch (channel->state){ 1739 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1740 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1741 // failure, forward error code 1742 l2cap_emit_channel_opened(channel, status); 1743 // discard channel 1744 l2cap_stop_rtx(channel); 1745 btstack_linked_list_iterator_remove(&it); 1746 btstack_memory_l2cap_channel_free(channel); 1747 break; 1748 default: 1749 break; 1750 } 1751 } 1752 } 1753 1754 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1755 btstack_linked_list_iterator_t it; 1756 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1757 while (btstack_linked_list_iterator_has_next(&it)){ 1758 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1759 if ( ! bd_addr_cmp( channel->address, address) ){ 1760 l2cap_handle_connection_complete(handle, channel); 1761 } 1762 } 1763 // process 1764 l2cap_run(); 1765 } 1766 #endif 1767 1768 static void l2cap_notify_channel_can_send(void){ 1769 1770 #ifdef ENABLE_CLASSIC 1771 btstack_linked_list_iterator_t it; 1772 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1773 while (btstack_linked_list_iterator_has_next(&it)){ 1774 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1775 if (!channel->waiting_for_can_send_now) continue; 1776 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1777 channel->waiting_for_can_send_now = 0; 1778 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1779 } 1780 #endif 1781 1782 int i; 1783 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1784 if (!fixed_channels[i].callback) continue; 1785 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1786 int can_send = 0; 1787 if (l2cap_fixed_channel_table_index_is_le(i)){ 1788 #ifdef ENABLE_BLE 1789 can_send = hci_can_send_acl_le_packet_now(); 1790 #endif 1791 } else { 1792 #ifdef ENABLE_CLASSIC 1793 can_send = hci_can_send_acl_classic_packet_now(); 1794 #endif 1795 } 1796 if (!can_send) continue; 1797 fixed_channels[i].waiting_for_can_send_now = 0; 1798 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1799 } 1800 } 1801 1802 #ifdef L2CAP_USES_CHANNELS 1803 1804 static int l2cap_send_open_failed_on_hci_disconnect(l2cap_channel_t * channel){ 1805 // open cannot fail for for incoming connections 1806 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING) return 0; 1807 1808 // check state 1809 switch (channel->state){ 1810 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1811 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1812 case L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES: 1813 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1814 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 1815 case L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES: 1816 case L2CAP_STATE_WAIT_CONNECT_RSP: 1817 case L2CAP_STATE_CONFIG: 1818 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 1819 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 1820 case L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE: 1821 return 1; 1822 1823 case L2CAP_STATE_OPEN: 1824 case L2CAP_STATE_CLOSED: 1825 case L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES: 1826 case L2CAP_STATE_WAIT_DISCONNECT: 1827 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_INSUFFICIENT_SECURITY: 1828 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 1829 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 1830 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1831 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 1832 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 1833 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 1834 case L2CAP_STATE_INVALID: 1835 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1836 return 0; 1837 } 1838 } 1839 1840 static void l2cap_handle_hci_disconnect_event(l2cap_channel_t * channel){ 1841 if (l2cap_send_open_failed_on_hci_disconnect(channel)){ 1842 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_BASEBAND_DISCONNECT); 1843 } else { 1844 l2cap_emit_channel_closed(channel); 1845 } 1846 btstack_memory_l2cap_channel_free(channel); 1847 } 1848 1849 #endif 1850 1851 1852 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1853 1854 UNUSED(packet_type); 1855 UNUSED(cid); 1856 UNUSED(size); 1857 1858 bd_addr_t address; 1859 hci_con_handle_t handle; 1860 int hci_con_used; 1861 btstack_linked_list_iterator_t it; 1862 1863 // avoid unused warnings 1864 UNUSED(address); 1865 UNUSED(hci_con_used); 1866 UNUSED(it); 1867 UNUSED(handle); 1868 1869 switch(hci_event_packet_get_type(packet)){ 1870 1871 // Notify channel packet handler if they can send now 1872 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1873 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1874 l2cap_run(); // try sending signaling packets first 1875 l2cap_notify_channel_can_send(); 1876 break; 1877 1878 case HCI_EVENT_COMMAND_STATUS: 1879 l2cap_run(); // try sending signaling packets first 1880 break; 1881 1882 #ifdef ENABLE_CLASSIC 1883 // handle connection complete events 1884 case HCI_EVENT_CONNECTION_COMPLETE: 1885 reverse_bd_addr(&packet[5], address); 1886 if (packet[2] == 0){ 1887 handle = little_endian_read_16(packet, 3); 1888 l2cap_handle_connection_success_for_addr(address, handle); 1889 } else { 1890 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1891 } 1892 break; 1893 1894 // handle successful create connection cancel command 1895 case HCI_EVENT_COMMAND_COMPLETE: 1896 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1897 if (packet[5] == 0){ 1898 reverse_bd_addr(&packet[6], address); 1899 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1900 l2cap_handle_connection_failed_for_addr(address, 0x16); 1901 } 1902 } 1903 l2cap_run(); // try sending signaling packets first 1904 break; 1905 #endif 1906 1907 #ifdef L2CAP_USES_CHANNELS 1908 // handle disconnection complete events 1909 case HCI_EVENT_DISCONNECTION_COMPLETE: 1910 handle = little_endian_read_16(packet, 3); 1911 // send l2cap open failed or closed events for all channels on this handle and free them 1912 #ifdef ENABLE_CLASSIC 1913 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1914 while (btstack_linked_list_iterator_has_next(&it)){ 1915 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1916 if (channel->con_handle != handle) continue; 1917 btstack_linked_list_iterator_remove(&it); 1918 l2cap_stop_rtx(channel); 1919 l2cap_handle_hci_disconnect_event(channel); 1920 } 1921 #endif 1922 #ifdef ENABLE_LE_DATA_CHANNELS 1923 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1924 while (btstack_linked_list_iterator_has_next(&it)){ 1925 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1926 if (channel->con_handle != handle) continue; 1927 btstack_linked_list_iterator_remove(&it); 1928 l2cap_handle_hci_disconnect_event(channel); 1929 } 1930 #endif 1931 break; 1932 #endif 1933 1934 // HCI Connection Timeouts 1935 #ifdef ENABLE_CLASSIC 1936 case L2CAP_EVENT_TIMEOUT_CHECK: 1937 handle = little_endian_read_16(packet, 2); 1938 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1939 if (hci_authentication_active_for_handle(handle)) break; 1940 hci_con_used = 0; 1941 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1942 while (btstack_linked_list_iterator_has_next(&it)){ 1943 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1944 if (channel->con_handle != handle) continue; 1945 hci_con_used = 1; 1946 break; 1947 } 1948 if (hci_con_used) break; 1949 if (!hci_can_send_command_packet_now()) break; 1950 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1951 break; 1952 1953 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1954 handle = little_endian_read_16(packet, 3); 1955 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1956 while (btstack_linked_list_iterator_has_next(&it)){ 1957 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1958 if (channel->con_handle != handle) continue; 1959 l2cap_handle_remote_supported_features_received(channel); 1960 break; 1961 } 1962 break; 1963 1964 case GAP_EVENT_SECURITY_LEVEL: 1965 handle = little_endian_read_16(packet, 2); 1966 log_info("l2cap - security level update"); 1967 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1968 while (btstack_linked_list_iterator_has_next(&it)){ 1969 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1970 if (channel->con_handle != handle) continue; 1971 1972 log_info("l2cap - state %u", channel->state); 1973 1974 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1975 gap_security_level_t required_level = channel->required_security_level; 1976 1977 switch (channel->state){ 1978 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1979 if (actual_level >= required_level){ 1980 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1981 // we need to know if ERTM is supported before sending a config response 1982 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1983 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 1984 channel->state = L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES; 1985 #else 1986 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1987 l2cap_emit_incoming_connection(channel); 1988 #endif 1989 } else { 1990 channel->reason = 0x0003; // security block 1991 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1992 } 1993 break; 1994 1995 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1996 if (actual_level >= required_level){ 1997 l2cap_ready_to_connect(channel); 1998 } else { 1999 // disconnnect, authentication not good enough 2000 hci_disconnect_security_block(handle); 2001 } 2002 break; 2003 2004 default: 2005 break; 2006 } 2007 } 2008 break; 2009 #endif 2010 2011 default: 2012 break; 2013 } 2014 2015 l2cap_run(); 2016 } 2017 2018 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t cid, uint16_t data){ 2019 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 2020 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 2021 signaling_responses[signaling_responses_pending].handle = handle; 2022 signaling_responses[signaling_responses_pending].code = code; 2023 signaling_responses[signaling_responses_pending].sig_id = sig_id; 2024 signaling_responses[signaling_responses_pending].cid = cid; 2025 signaling_responses[signaling_responses_pending].data = data; 2026 signaling_responses_pending++; 2027 l2cap_run(); 2028 } 2029 } 2030 2031 #ifdef ENABLE_CLASSIC 2032 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 2033 channel->remote_sig_id = identifier; 2034 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 2035 l2cap_run(); 2036 } 2037 2038 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 2039 2040 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 2041 l2cap_service_t *service = l2cap_get_service(psm); 2042 if (!service) { 2043 // 0x0002 PSM not supported 2044 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 2045 return; 2046 } 2047 2048 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 2049 if (!hci_connection) { 2050 // 2051 log_error("no hci_connection for handle %u", handle); 2052 return; 2053 } 2054 2055 // alloc structure 2056 // log_info("l2cap_handle_connection_request register channel"); 2057 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 2058 psm, service->mtu, service->required_security_level); 2059 if (!channel){ 2060 // 0x0004 No resources available 2061 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 2062 return; 2063 } 2064 2065 channel->con_handle = handle; 2066 channel->remote_cid = source_cid; 2067 channel->remote_sig_id = sig_id; 2068 2069 // limit local mtu to max acl packet length - l2cap header 2070 if (channel->local_mtu > l2cap_max_mtu()) { 2071 channel->local_mtu = l2cap_max_mtu(); 2072 } 2073 2074 // set initial state 2075 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 2076 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND | L2CAP_CHANNEL_STATE_VAR_INCOMING); 2077 2078 // add to connections list 2079 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 2080 2081 // assert security requirements 2082 gap_request_security_level(handle, channel->required_security_level); 2083 } 2084 2085 void l2cap_accept_connection(uint16_t local_cid){ 2086 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 2087 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 2088 if (!channel) { 2089 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 2090 return; 2091 } 2092 2093 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2094 // configure L2CAP Basic mode 2095 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2096 #endif 2097 2098 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 2099 2100 // process 2101 l2cap_run(); 2102 } 2103 2104 void l2cap_decline_connection(uint16_t local_cid){ 2105 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 2106 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 2107 if (!channel) { 2108 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 2109 return; 2110 } 2111 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 2112 channel->reason = 0x04; // no resources available 2113 l2cap_run(); 2114 } 2115 2116 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 2117 2118 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2119 2120 uint16_t flags = little_endian_read_16(command, 6); 2121 if (flags & 1) { 2122 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 2123 } 2124 2125 // accept the other's configuration options 2126 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2127 uint16_t pos = 8; 2128 while (pos < end_pos){ 2129 uint8_t option_hint = command[pos] >> 7; 2130 uint8_t option_type = command[pos] & 0x7f; 2131 // log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 2132 pos++; 2133 uint8_t length = command[pos++]; 2134 // MTU { type(8): 1, len(8):2, MTU(16) } 2135 if (option_type == L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT && length == 2){ 2136 channel->remote_mtu = little_endian_read_16(command, pos); 2137 log_info("Remote MTU %u", channel->remote_mtu); 2138 if (channel->remote_mtu > l2cap_max_mtu()){ 2139 log_info("Remote MTU %u larger than outgoing buffer, only using MTU = %u", channel->remote_mtu, l2cap_max_mtu()); 2140 channel->remote_mtu = l2cap_max_mtu(); 2141 } 2142 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 2143 } 2144 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 2145 if (option_type == L2CAP_CONFIG_OPTION_TYPE_FLUSH_TIMEOUT && length == 2){ 2146 channel->flush_timeout = little_endian_read_16(command, pos); 2147 log_info("Flush timeout: %u ms", channel->flush_timeout); 2148 } 2149 2150 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2151 // Retransmission and Flow Control Option 2152 if (option_type == L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL && length == 9){ 2153 l2cap_channel_mode_t mode = (l2cap_channel_mode_t) command[pos]; 2154 switch(channel->mode){ 2155 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 2156 // Store remote config 2157 channel->remote_tx_window_size = command[pos+1]; 2158 channel->remote_max_transmit = command[pos+2]; 2159 channel->remote_retransmission_timeout_ms = little_endian_read_16(command, pos + 3); 2160 channel->remote_monitor_timeout_ms = little_endian_read_16(command, pos + 5); 2161 channel->remote_mps = little_endian_read_16(command, pos + 7); 2162 log_info("FC&C config: tx window: %u, max transmit %u, retrans timeout %u, monitor timeout %u, mps %u", 2163 channel->remote_tx_window_size, 2164 channel->remote_max_transmit, 2165 channel->remote_retransmission_timeout_ms, 2166 channel->remote_monitor_timeout_ms, 2167 channel->remote_mps); 2168 // If ERTM mandatory, but remote doens't offer ERTM -> disconnect 2169 if (channel->ertm_mandatory && mode != L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 2170 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2171 } else { 2172 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 2173 } 2174 break; 2175 case L2CAP_CHANNEL_MODE_BASIC: 2176 switch (mode){ 2177 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 2178 // remote asks for ERTM, but we want basic mode. disconnect if this happens a second time 2179 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED){ 2180 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2181 } 2182 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED); 2183 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 2184 break; 2185 default: // case L2CAP_CHANNEL_MODE_BASIC: 2186 // TODO store and evaluate configuration 2187 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 2188 break; 2189 } 2190 break; 2191 default: 2192 break; 2193 } 2194 } 2195 #endif 2196 // check for unknown options 2197 if (option_hint == 0 && (option_type < L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT || option_type > L2CAP_CONFIG_OPTION_TYPE_EXTENDED_WINDOW_SIZE)){ 2198 log_info("l2cap cid %u, unknown options", channel->local_cid); 2199 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 2200 } 2201 pos += length; 2202 } 2203 } 2204 2205 static void l2cap_signaling_handle_configure_response(l2cap_channel_t *channel, uint8_t result, uint8_t *command){ 2206 log_info("l2cap_signaling_handle_configure_response"); 2207 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2208 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2209 uint16_t pos = 10; 2210 while (pos < end_pos){ 2211 uint8_t option_hint = command[pos] >> 7; 2212 uint8_t option_type = command[pos] & 0x7f; 2213 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 2214 pos++; 2215 uint8_t length = command[pos++]; 2216 2217 // Retransmission and Flow Control Option 2218 if (option_type == L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL && length == 9){ 2219 switch (channel->mode){ 2220 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 2221 if (channel->ertm_mandatory){ 2222 // ?? 2223 } else { 2224 // On 'Reject - Unacceptable Parameters' to our optional ERTM request, fall back to BASIC mode 2225 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 2226 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2227 } 2228 } 2229 break; 2230 case L2CAP_CHANNEL_MODE_BASIC: 2231 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 2232 // On 'Reject - Unacceptable Parameters' to our Basic mode request, disconnect 2233 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2234 } 2235 break; 2236 default: 2237 break; 2238 } 2239 } 2240 2241 // check for unknown options 2242 if (option_hint == 0 && (option_type < L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT || option_type > L2CAP_CONFIG_OPTION_TYPE_EXTENDED_WINDOW_SIZE)){ 2243 log_info("l2cap cid %u, unknown options", channel->local_cid); 2244 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 2245 } 2246 2247 pos += length; 2248 } 2249 #else 2250 UNUSED(channel); 2251 UNUSED(result); 2252 UNUSED(command); 2253 #endif 2254 } 2255 2256 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 2257 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 2258 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 2259 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 2260 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 2261 if (channel->state == L2CAP_STATE_OPEN) return 0; 2262 return 1; 2263 } 2264 2265 2266 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 2267 2268 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2269 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2270 uint16_t result = 0; 2271 2272 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 2273 2274 // handle DISCONNECT REQUESTS seperately 2275 if (code == DISCONNECTION_REQUEST){ 2276 switch (channel->state){ 2277 case L2CAP_STATE_CONFIG: 2278 case L2CAP_STATE_OPEN: 2279 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 2280 case L2CAP_STATE_WAIT_DISCONNECT: 2281 l2cap_handle_disconnect_request(channel, identifier); 2282 break; 2283 2284 default: 2285 // ignore in other states 2286 break; 2287 } 2288 return; 2289 } 2290 2291 // @STATEMACHINE(l2cap) 2292 switch (channel->state) { 2293 2294 case L2CAP_STATE_WAIT_CONNECT_RSP: 2295 switch (code){ 2296 case CONNECTION_RESPONSE: 2297 l2cap_stop_rtx(channel); 2298 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2299 switch (result) { 2300 case 0: 2301 // successful connection 2302 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2303 channel->state = L2CAP_STATE_CONFIG; 2304 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 2305 break; 2306 case 1: 2307 // connection pending. get some coffee, but start the ERTX 2308 l2cap_start_ertx(channel); 2309 break; 2310 default: 2311 // channel closed 2312 channel->state = L2CAP_STATE_CLOSED; 2313 // map l2cap connection response result to BTstack status enumeration 2314 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 2315 2316 // drop link key if security block 2317 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 2318 gap_drop_link_key_for_bd_addr(channel->address); 2319 } 2320 2321 // discard channel 2322 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2323 btstack_memory_l2cap_channel_free(channel); 2324 break; 2325 } 2326 break; 2327 2328 default: 2329 //@TODO: implement other signaling packets 2330 break; 2331 } 2332 break; 2333 2334 case L2CAP_STATE_CONFIG: 2335 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2336 switch (code) { 2337 case CONFIGURE_REQUEST: 2338 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 2339 l2cap_signaling_handle_configure_request(channel, command); 2340 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 2341 // only done if continuation not set 2342 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 2343 } 2344 break; 2345 case CONFIGURE_RESPONSE: 2346 l2cap_stop_rtx(channel); 2347 l2cap_signaling_handle_configure_response(channel, result, command); 2348 switch (result){ 2349 case 0: // success 2350 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 2351 break; 2352 case 4: // pending 2353 l2cap_start_ertx(channel); 2354 break; 2355 default: 2356 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2357 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION && channel->ertm_mandatory){ 2358 // remote does not offer ertm but it's required 2359 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2360 break; 2361 } 2362 #endif 2363 // retry on negative result 2364 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 2365 break; 2366 } 2367 break; 2368 default: 2369 break; 2370 } 2371 if (l2cap_channel_ready_for_open(channel)){ 2372 // for open: 2373 channel->state = L2CAP_STATE_OPEN; 2374 l2cap_emit_channel_opened(channel, 0); 2375 } 2376 break; 2377 2378 case L2CAP_STATE_WAIT_DISCONNECT: 2379 switch (code) { 2380 case DISCONNECTION_RESPONSE: 2381 l2cap_finialize_channel_close(channel); 2382 break; 2383 default: 2384 //@TODO: implement other signaling packets 2385 break; 2386 } 2387 break; 2388 2389 case L2CAP_STATE_CLOSED: 2390 // @TODO handle incoming requests 2391 break; 2392 2393 case L2CAP_STATE_OPEN: 2394 //@TODO: implement other signaling packets, e.g. re-configure 2395 break; 2396 default: 2397 break; 2398 } 2399 // log_info("new state %u", channel->state); 2400 } 2401 2402 2403 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 2404 2405 btstack_linked_list_iterator_t it; 2406 2407 // get code, signalind identifier and command len 2408 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2409 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2410 2411 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_RESPONSE 2412 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_RESPONSE){ 2413 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2414 return; 2415 } 2416 2417 // general commands without an assigned channel 2418 switch(code) { 2419 2420 case CONNECTION_REQUEST: { 2421 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2422 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2423 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 2424 return; 2425 } 2426 2427 case ECHO_REQUEST: 2428 l2cap_register_signaling_response(handle, code, sig_id, 0, 0); 2429 return; 2430 2431 case INFORMATION_REQUEST: { 2432 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2433 l2cap_register_signaling_response(handle, code, sig_id, 0, info_type); 2434 return; 2435 } 2436 2437 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2438 case INFORMATION_RESPONSE: { 2439 hci_connection_t * connection = hci_connection_for_handle(handle); 2440 if (!connection) return; 2441 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2442 uint16_t result = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2443 if (result != 0) return; 2444 if (info_type != L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED) return; 2445 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_DONE; 2446 connection->l2cap_state.extended_feature_mask = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2447 log_info("extended features mask 0x%02x", connection->l2cap_state.extended_feature_mask); 2448 // trigger connection request 2449 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2450 while (btstack_linked_list_iterator_has_next(&it)){ 2451 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2452 if (channel->con_handle != handle) continue; 2453 // bail if ERTM was requested but is not supported 2454 if ((channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION) && ((connection->l2cap_state.extended_feature_mask & 0x08) == 0)){ 2455 if (channel->ertm_mandatory){ 2456 // channel closed 2457 channel->state = L2CAP_STATE_CLOSED; 2458 // map l2cap connection response result to BTstack status enumeration 2459 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_ERTM_NOT_SUPPORTD); 2460 // discard channel 2461 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2462 btstack_memory_l2cap_channel_free(channel); 2463 continue; 2464 } else { 2465 // fallback to Basic mode 2466 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2467 } 2468 } 2469 // start connecting 2470 if (channel->state == L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES){ 2471 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 2472 } 2473 // respond to connection request 2474 if (channel->state == L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES){ 2475 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2476 l2cap_emit_incoming_connection(channel); 2477 } 2478 } 2479 return; 2480 } 2481 #endif 2482 2483 default: 2484 break; 2485 } 2486 2487 2488 // Get potential destination CID 2489 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2490 2491 // Find channel for this sig_id and connection handle 2492 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2493 while (btstack_linked_list_iterator_has_next(&it)){ 2494 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2495 if (channel->con_handle != handle) continue; 2496 if (code & 1) { 2497 // match odd commands (responses) by previous signaling identifier 2498 if (channel->local_sig_id == sig_id) { 2499 l2cap_signaling_handler_channel(channel, command); 2500 break; 2501 } 2502 } else { 2503 // match even commands (requests) by local channel id 2504 if (channel->local_cid == dest_cid) { 2505 l2cap_signaling_handler_channel(channel, command); 2506 break; 2507 } 2508 } 2509 } 2510 } 2511 #endif 2512 2513 #ifdef ENABLE_BLE 2514 2515 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 2516 uint8_t event[6]; 2517 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 2518 event[1] = 4; 2519 little_endian_store_16(event, 2, con_handle); 2520 little_endian_store_16(event, 4, result); 2521 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2522 if (!l2cap_event_packet_handler) return; 2523 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 2524 } 2525 2526 // @returns valid 2527 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 2528 hci_connection_t * connection; 2529 uint16_t result; 2530 uint8_t event[10]; 2531 2532 #ifdef ENABLE_LE_DATA_CHANNELS 2533 btstack_linked_list_iterator_t it; 2534 l2cap_channel_t * channel; 2535 uint16_t local_cid; 2536 uint16_t le_psm; 2537 uint16_t new_credits; 2538 uint16_t credits_before; 2539 l2cap_service_t * service; 2540 uint16_t source_cid; 2541 #endif 2542 2543 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2544 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 2545 2546 switch (code){ 2547 2548 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 2549 result = little_endian_read_16(command, 4); 2550 l2cap_emit_connection_parameter_update_response(handle, result); 2551 break; 2552 2553 case CONNECTION_PARAMETER_UPDATE_REQUEST: 2554 connection = hci_connection_for_handle(handle); 2555 if (connection){ 2556 if (connection->role != HCI_ROLE_MASTER){ 2557 // reject command without notifying upper layer when not in master role 2558 return 0; 2559 } 2560 int update_parameter = 1; 2561 le_connection_parameter_range_t existing_range; 2562 gap_get_connection_parameter_range(&existing_range); 2563 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 2564 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 2565 uint16_t le_conn_latency = little_endian_read_16(command,12); 2566 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 2567 2568 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 2569 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 2570 2571 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 2572 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 2573 2574 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 2575 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 2576 2577 if (update_parameter){ 2578 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 2579 connection->le_conn_interval_min = le_conn_interval_min; 2580 connection->le_conn_interval_max = le_conn_interval_max; 2581 connection->le_conn_latency = le_conn_latency; 2582 connection->le_supervision_timeout = le_supervision_timeout; 2583 } else { 2584 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 2585 } 2586 connection->le_con_param_update_identifier = sig_id; 2587 } 2588 2589 if (!l2cap_event_packet_handler) break; 2590 2591 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 2592 event[1] = 8; 2593 memcpy(&event[2], &command[4], 8); 2594 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2595 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2596 break; 2597 2598 #ifdef ENABLE_LE_DATA_CHANNELS 2599 2600 case COMMAND_REJECT: 2601 // Find channel for this sig_id and connection handle 2602 channel = NULL; 2603 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2604 while (btstack_linked_list_iterator_has_next(&it)){ 2605 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2606 if (a_channel->con_handle != handle) continue; 2607 if (a_channel->local_sig_id != sig_id) continue; 2608 channel = a_channel; 2609 break; 2610 } 2611 if (!channel) break; 2612 2613 // if received while waiting for le connection response, assume legacy device 2614 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 2615 channel->state = L2CAP_STATE_CLOSED; 2616 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 2617 l2cap_emit_le_channel_opened(channel, 0x0002); 2618 2619 // discard channel 2620 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2621 btstack_memory_l2cap_channel_free(channel); 2622 break; 2623 } 2624 break; 2625 2626 case LE_CREDIT_BASED_CONNECTION_REQUEST: 2627 2628 // get hci connection, bail if not found (must not happen) 2629 connection = hci_connection_for_handle(handle); 2630 if (!connection) return 0; 2631 2632 // check if service registered 2633 le_psm = little_endian_read_16(command, 4); 2634 service = l2cap_le_get_service(le_psm); 2635 source_cid = little_endian_read_16(command, 6); 2636 2637 if (service){ 2638 if (source_cid < 0x40){ 2639 // 0x0009 Connection refused - Invalid Source CID 2640 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0009); 2641 return 1; 2642 } 2643 2644 // go through list of channels for this ACL connection and check if we get a match 2645 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2646 while (btstack_linked_list_iterator_has_next(&it)){ 2647 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2648 if (a_channel->con_handle != handle) continue; 2649 if (a_channel->remote_cid != source_cid) continue; 2650 // 0x000a Connection refused - Source CID already allocated 2651 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x000a); 2652 return 1; 2653 } 2654 2655 // security: check encryption 2656 if (service->required_security_level >= LEVEL_2){ 2657 if (sm_encryption_key_size(handle) == 0){ 2658 // 0x0008 Connection refused - insufficient encryption 2659 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0008); 2660 return 1; 2661 } 2662 // anything less than 16 byte key size is insufficient 2663 if (sm_encryption_key_size(handle) < 16){ 2664 // 0x0007 Connection refused – insufficient encryption key size 2665 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0007); 2666 return 1; 2667 } 2668 } 2669 2670 // security: check authencation 2671 if (service->required_security_level >= LEVEL_3){ 2672 if (!sm_authenticated(handle)){ 2673 // 0x0005 Connection refused – insufficient authentication 2674 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0005); 2675 return 1; 2676 } 2677 } 2678 2679 // security: check authorization 2680 if (service->required_security_level >= LEVEL_4){ 2681 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 2682 // 0x0006 Connection refused – insufficient authorization 2683 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0006); 2684 return 1; 2685 } 2686 } 2687 2688 // allocate channel 2689 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 2690 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 2691 if (!channel){ 2692 // 0x0004 Connection refused – no resources available 2693 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 2694 return 1; 2695 } 2696 2697 channel->con_handle = handle; 2698 channel->remote_cid = source_cid; 2699 channel->remote_sig_id = sig_id; 2700 channel->remote_mtu = little_endian_read_16(command, 8); 2701 channel->remote_mps = little_endian_read_16(command, 10); 2702 channel->credits_outgoing = little_endian_read_16(command, 12); 2703 2704 // set initial state 2705 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2706 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 2707 2708 // add to connections list 2709 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2710 2711 // post connection request event 2712 l2cap_emit_le_incoming_connection(channel); 2713 2714 } else { 2715 // Connection refused – LE_PSM not supported 2716 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 2717 } 2718 break; 2719 2720 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 2721 // Find channel for this sig_id and connection handle 2722 channel = NULL; 2723 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2724 while (btstack_linked_list_iterator_has_next(&it)){ 2725 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2726 if (a_channel->con_handle != handle) continue; 2727 if (a_channel->local_sig_id != sig_id) continue; 2728 channel = a_channel; 2729 break; 2730 } 2731 if (!channel) break; 2732 2733 // cid + 0 2734 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 2735 if (result){ 2736 channel->state = L2CAP_STATE_CLOSED; 2737 // map l2cap connection response result to BTstack status enumeration 2738 l2cap_emit_le_channel_opened(channel, result); 2739 2740 // discard channel 2741 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2742 btstack_memory_l2cap_channel_free(channel); 2743 break; 2744 } 2745 2746 // success 2747 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2748 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2749 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 2750 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 2751 channel->state = L2CAP_STATE_OPEN; 2752 l2cap_emit_le_channel_opened(channel, result); 2753 break; 2754 2755 case LE_FLOW_CONTROL_CREDIT: 2756 // find channel 2757 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2758 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2759 if (!channel) { 2760 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2761 break; 2762 } 2763 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2764 credits_before = channel->credits_outgoing; 2765 channel->credits_outgoing += new_credits; 2766 // check for credit overrun 2767 if (credits_before > channel->credits_outgoing){ 2768 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 2769 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2770 break; 2771 } 2772 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 2773 break; 2774 2775 case DISCONNECTION_REQUEST: 2776 // find channel 2777 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2778 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2779 if (!channel) { 2780 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2781 break; 2782 } 2783 channel->remote_sig_id = sig_id; 2784 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 2785 break; 2786 2787 #endif 2788 2789 case DISCONNECTION_RESPONSE: 2790 break; 2791 2792 default: 2793 // command unknown -> reject command 2794 return 0; 2795 } 2796 return 1; 2797 } 2798 #endif 2799 2800 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 2801 UNUSED(packet_type); 2802 UNUSED(channel); 2803 2804 l2cap_channel_t * l2cap_channel; 2805 UNUSED(l2cap_channel); 2806 2807 // Get Channel ID 2808 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 2809 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 2810 2811 switch (channel_id) { 2812 2813 #ifdef ENABLE_CLASSIC 2814 case L2CAP_CID_SIGNALING: { 2815 uint16_t command_offset = 8; 2816 while (command_offset < size) { 2817 // handle signaling commands 2818 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 2819 2820 // increment command_offset 2821 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2822 } 2823 break; 2824 } 2825 #endif 2826 2827 #ifdef ENABLE_BLE 2828 case L2CAP_CID_SIGNALING_LE: { 2829 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 2830 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 2831 if (!valid){ 2832 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2833 } 2834 break; 2835 } 2836 #endif 2837 2838 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 2839 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 2840 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2841 } 2842 break; 2843 2844 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 2845 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 2846 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2847 } 2848 break; 2849 2850 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 2851 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 2852 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2853 } 2854 break; 2855 2856 default: 2857 #ifdef ENABLE_CLASSIC 2858 // Find channel for this channel_id and connection handle 2859 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 2860 if (l2cap_channel) { 2861 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2862 if (l2cap_channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 2863 2864 // verify FCS 2865 uint16_t fcs_calculated = crc16_calc(&packet[4], size - (4+2)); 2866 uint16_t fcs_packet = little_endian_read_16(packet, size-2); 2867 log_info("Packet FCS 0x%04x, calculated FCS 0x%04x", fcs_packet, fcs_calculated); 2868 if (fcs_calculated != fcs_packet){ 2869 log_error("FCS mismatch! Packet 0x%04x, calculated 0x%04x", fcs_packet, fcs_calculated); 2870 // TODO: trigger retransmission or something like that 2871 break; 2872 } 2873 2874 // switch on packet type 2875 uint16_t control = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 2876 uint8_t req_seq = (control >> 8) & 0x3f; 2877 int final = (control >> 7) & 0x01; 2878 if (control & 1){ 2879 // S-Frame 2880 int poll = (control >> 4) & 0x01; 2881 l2cap_supervisory_function_t s = (l2cap_supervisory_function_t) ((control >> 2) & 0x03); 2882 log_info("Control: 0x%04x => Supervisory function %u, ReqSeq %02u", control, (int) s, req_seq); 2883 l2cap_ertm_tx_packet_state_t * tx_state; 2884 switch (s){ 2885 case L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY: 2886 log_info("L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY"); 2887 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 2888 if (poll && final){ 2889 // S-frames shall not be transmitted with both the F-bit and the P-bit set to 1 at the same time. 2890 log_error("P=F=1 in S-Frame"); 2891 break; 2892 } 2893 if (poll){ 2894 // check if we did request selective retransmission before <==> we have stored SDU segments 2895 int i; 2896 int num_stored_out_of_order_packets = 0; 2897 for (i=0;i<l2cap_channel->num_rx_buffers;i++){ 2898 int index = l2cap_channel->rx_store_index + i; 2899 if (index >= l2cap_channel->num_rx_buffers){ 2900 index -= l2cap_channel->num_rx_buffers; 2901 } 2902 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 2903 if (!rx_state->valid) continue; 2904 num_stored_out_of_order_packets++; 2905 } 2906 if (num_stored_out_of_order_packets){ 2907 l2cap_channel->send_supervisor_frame_selective_reject = 1; 2908 } else { 2909 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 2910 } 2911 l2cap_channel->set_final_bit_after_packet_with_poll_bit_set = 1; 2912 } 2913 if (final){ 2914 // Stop-MonitorTimer 2915 l2cap_ertm_stop_monitor_timer(l2cap_channel); 2916 // If UnackedFrames > 0 then Start-RetransTimer 2917 if (l2cap_channel->unacked_frames){ 2918 l2cap_ertm_start_retransmission_timer(l2cap_channel); 2919 } 2920 2921 // final bit set <- response to RR with poll bit set. All not acknowledged packets need to be retransmitted 2922 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 2923 } 2924 break; 2925 case L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT: 2926 log_info("L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT"); 2927 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 2928 // rsetart transmittion from last unacknowledted packet (earlier packets already freed in l2cap_ertm_process_req_seq) 2929 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 2930 break; 2931 case L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY: 2932 log_error("L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY"); 2933 break; 2934 case L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT: 2935 log_info("L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT"); 2936 if (poll){ 2937 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 2938 } 2939 // find requested i-frame 2940 tx_state = l2cap_ertm_get_tx_state(l2cap_channel, req_seq); 2941 if (tx_state){ 2942 log_info("Retransmission for tx_seq %u requested", req_seq); 2943 l2cap_channel->set_final_bit_after_packet_with_poll_bit_set = poll; 2944 tx_state->retransmission_requested = 1; 2945 l2cap_channel->srej_active = 1; 2946 } 2947 break; 2948 default: 2949 break; 2950 } 2951 break; 2952 } else { 2953 // I-Frame 2954 // get control 2955 l2cap_segmentation_and_reassembly_t sar = (l2cap_segmentation_and_reassembly_t) (control >> 14); 2956 uint8_t tx_seq = (control >> 1) & 0x3f; 2957 log_info("Control: 0x%04x => SAR %u, ReqSeq %02u, R?, TxSeq %02u", control, (int) sar, req_seq, tx_seq); 2958 log_info("SAR: pos %u", l2cap_channel->reassembly_pos); 2959 log_info("State: expected_tx_seq %02u, req_seq %02u", l2cap_channel->expected_tx_seq, l2cap_channel->req_seq); 2960 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 2961 if (final){ 2962 // final bit set <- response to RR with poll bit set. All not acknowledged packets need to be retransmitted 2963 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 2964 } 2965 // check ordering 2966 if (l2cap_channel->expected_tx_seq == tx_seq){ 2967 log_info("Received expected frame with TxSeq == ExpectedTxSeq == %02u", tx_seq); 2968 l2cap_channel->expected_tx_seq = l2cap_next_ertm_seq_nr(l2cap_channel->expected_tx_seq); 2969 l2cap_channel->req_seq = l2cap_channel->expected_tx_seq; 2970 2971 // process SDU 2972 l2cap_ertm_handle_in_sequence_sdu(l2cap_channel, sar, &packet[COMPLETE_L2CAP_HEADER+2], size-(COMPLETE_L2CAP_HEADER+2+2)); 2973 2974 // process stored segments 2975 while (1){ 2976 int index = l2cap_channel->rx_store_index; 2977 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 2978 if (!rx_state->valid) break; 2979 2980 log_info("Processing stored frame with TxSeq == ExpectedTxSeq == %02u", l2cap_channel->expected_tx_seq); 2981 l2cap_channel->expected_tx_seq = l2cap_next_ertm_seq_nr(l2cap_channel->expected_tx_seq); 2982 l2cap_channel->req_seq = l2cap_channel->expected_tx_seq; 2983 2984 rx_state->valid = 0; 2985 l2cap_ertm_handle_in_sequence_sdu(l2cap_channel, rx_state->sar, &l2cap_channel->rx_packets_data[index], rx_state->len); 2986 2987 // update rx store index 2988 index++; 2989 if (index >= l2cap_channel->num_rx_buffers){ 2990 index = 0; 2991 } 2992 l2cap_channel->rx_store_index = index; 2993 } 2994 2995 // 2996 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 2997 2998 } else { 2999 int delta = (tx_seq - l2cap_channel->expected_tx_seq) & 0x3f; 3000 if (delta < 2){ 3001 // store segment 3002 l2cap_ertm_handle_out_of_sequence_sdu(l2cap_channel, sar, delta, &packet[COMPLETE_L2CAP_HEADER+2], size-(COMPLETE_L2CAP_HEADER+2+2)); 3003 3004 log_info("Received unexpected frame TxSeq %u but expected %u -> send S-SREJ", tx_seq, l2cap_channel->expected_tx_seq); 3005 l2cap_channel->send_supervisor_frame_selective_reject = 1; 3006 } else { 3007 log_info("Received unexpected frame TxSeq %u but expected %u -> send S-REJ", tx_seq, l2cap_channel->expected_tx_seq); 3008 l2cap_channel->send_supervisor_frame_reject = 1; 3009 } 3010 } 3011 } 3012 break; 3013 } 3014 #endif 3015 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 3016 } 3017 #endif 3018 #ifdef ENABLE_LE_DATA_CHANNELS 3019 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 3020 if (l2cap_channel) { 3021 // credit counting 3022 if (l2cap_channel->credits_incoming == 0){ 3023 log_error("LE Data Channel packet received but no incoming credits"); 3024 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3025 break; 3026 } 3027 l2cap_channel->credits_incoming--; 3028 3029 // automatic credits 3030 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 3031 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 3032 } 3033 3034 // first fragment 3035 uint16_t pos = 0; 3036 if (!l2cap_channel->receive_sdu_len){ 3037 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 3038 l2cap_channel->receive_sdu_pos = 0; 3039 pos += 2; 3040 size -= 2; 3041 } 3042 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 3043 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 3044 // done? 3045 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 3046 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 3047 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 3048 l2cap_channel->receive_sdu_len = 0; 3049 } 3050 } else { 3051 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 3052 } 3053 #endif 3054 break; 3055 } 3056 3057 l2cap_run(); 3058 } 3059 3060 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 3061 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 3062 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 3063 if (index < 0) return; 3064 fixed_channels[index].callback = the_packet_handler; 3065 } 3066 3067 #ifdef ENABLE_CLASSIC 3068 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 3069 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 3070 channel->state = L2CAP_STATE_CLOSED; 3071 l2cap_emit_channel_closed(channel); 3072 // discard channel 3073 l2cap_stop_rtx(channel); 3074 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 3075 btstack_memory_l2cap_channel_free(channel); 3076 } 3077 3078 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 3079 btstack_linked_list_iterator_t it; 3080 btstack_linked_list_iterator_init(&it, services); 3081 while (btstack_linked_list_iterator_has_next(&it)){ 3082 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 3083 if ( service->psm == psm){ 3084 return service; 3085 }; 3086 } 3087 return NULL; 3088 } 3089 3090 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 3091 return l2cap_get_service_internal(&l2cap_services, psm); 3092 } 3093 3094 3095 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 3096 3097 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 3098 3099 // check for alread registered psm 3100 l2cap_service_t *service = l2cap_get_service(psm); 3101 if (service) { 3102 log_error("l2cap_register_service: PSM %u already registered", psm); 3103 return L2CAP_SERVICE_ALREADY_REGISTERED; 3104 } 3105 3106 // alloc structure 3107 service = btstack_memory_l2cap_service_get(); 3108 if (!service) { 3109 log_error("l2cap_register_service: no memory for l2cap_service_t"); 3110 return BTSTACK_MEMORY_ALLOC_FAILED; 3111 } 3112 3113 // fill in 3114 service->psm = psm; 3115 service->mtu = mtu; 3116 service->packet_handler = service_packet_handler; 3117 service->required_security_level = security_level; 3118 3119 // add to services list 3120 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 3121 3122 // enable page scan 3123 gap_connectable_control(1); 3124 3125 return 0; 3126 } 3127 3128 uint8_t l2cap_unregister_service(uint16_t psm){ 3129 3130 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 3131 3132 l2cap_service_t *service = l2cap_get_service(psm); 3133 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 3134 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 3135 btstack_memory_l2cap_service_free(service); 3136 3137 // disable page scan when no services registered 3138 if (btstack_linked_list_empty(&l2cap_services)) { 3139 gap_connectable_control(0); 3140 } 3141 return 0; 3142 } 3143 #endif 3144 3145 3146 #ifdef ENABLE_LE_DATA_CHANNELS 3147 3148 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 3149 if (!channel->waiting_for_can_send_now) return; 3150 if (channel->send_sdu_buffer) return; 3151 channel->waiting_for_can_send_now = 0; 3152 log_info("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 3153 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 3154 } 3155 3156 // 1BH2222 3157 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 3158 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", 3159 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 3160 uint8_t event[19]; 3161 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 3162 event[1] = sizeof(event) - 2; 3163 event[2] = channel->address_type; 3164 reverse_bd_addr(channel->address, &event[3]); 3165 little_endian_store_16(event, 9, channel->con_handle); 3166 little_endian_store_16(event, 11, channel->psm); 3167 little_endian_store_16(event, 13, channel->local_cid); 3168 little_endian_store_16(event, 15, channel->remote_cid); 3169 little_endian_store_16(event, 17, channel->remote_mtu); 3170 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 3171 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 3172 } 3173 // 11BH22222 3174 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 3175 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", 3176 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 3177 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 3178 uint8_t event[23]; 3179 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 3180 event[1] = sizeof(event) - 2; 3181 event[2] = status; 3182 event[3] = channel->address_type; 3183 reverse_bd_addr(channel->address, &event[4]); 3184 little_endian_store_16(event, 10, channel->con_handle); 3185 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 3186 little_endian_store_16(event, 13, channel->psm); 3187 little_endian_store_16(event, 15, channel->local_cid); 3188 little_endian_store_16(event, 17, channel->remote_cid); 3189 little_endian_store_16(event, 19, channel->local_mtu); 3190 little_endian_store_16(event, 21, channel->remote_mtu); 3191 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 3192 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 3193 } 3194 3195 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 3196 btstack_linked_list_iterator_t it; 3197 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 3198 while (btstack_linked_list_iterator_has_next(&it)){ 3199 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 3200 if ( channel->local_cid == local_cid) { 3201 return channel; 3202 } 3203 } 3204 return NULL; 3205 } 3206 3207 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 3208 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 3209 channel->state = L2CAP_STATE_CLOSED; 3210 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 3211 // discard channel 3212 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 3213 btstack_memory_l2cap_channel_free(channel); 3214 } 3215 3216 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 3217 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 3218 } 3219 3220 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 3221 3222 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 3223 3224 // check for alread registered psm 3225 l2cap_service_t *service = l2cap_le_get_service(psm); 3226 if (service) { 3227 return L2CAP_SERVICE_ALREADY_REGISTERED; 3228 } 3229 3230 // alloc structure 3231 service = btstack_memory_l2cap_service_get(); 3232 if (!service) { 3233 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 3234 return BTSTACK_MEMORY_ALLOC_FAILED; 3235 } 3236 3237 // fill in 3238 service->psm = psm; 3239 service->mtu = 0; 3240 service->packet_handler = packet_handler; 3241 service->required_security_level = security_level; 3242 3243 // add to services list 3244 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 3245 3246 // done 3247 return 0; 3248 } 3249 3250 uint8_t l2cap_le_unregister_service(uint16_t psm) { 3251 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 3252 l2cap_service_t *service = l2cap_le_get_service(psm); 3253 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 3254 3255 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 3256 btstack_memory_l2cap_service_free(service); 3257 return 0; 3258 } 3259 3260 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 3261 // get channel 3262 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3263 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3264 3265 // validate state 3266 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 3267 return ERROR_CODE_COMMAND_DISALLOWED; 3268 } 3269 3270 // set state accept connection 3271 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 3272 channel->receive_sdu_buffer = receive_sdu_buffer; 3273 channel->local_mtu = mtu; 3274 channel->new_credits_incoming = initial_credits; 3275 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 3276 3277 // test 3278 // channel->new_credits_incoming = 1; 3279 3280 // go 3281 l2cap_run(); 3282 return 0; 3283 } 3284 3285 /** 3286 * @brief Deny incoming LE Data Channel connection due to resource constraints 3287 * @param local_cid L2CAP LE Data Channel Identifier 3288 */ 3289 3290 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 3291 // get channel 3292 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3293 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3294 3295 // validate state 3296 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 3297 return ERROR_CODE_COMMAND_DISALLOWED; 3298 } 3299 3300 // set state decline connection 3301 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 3302 channel->reason = 0x04; // no resources available 3303 l2cap_run(); 3304 return 0; 3305 } 3306 3307 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 3308 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 3309 uint16_t * out_local_cid) { 3310 3311 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 3312 3313 3314 hci_connection_t * connection = hci_connection_for_handle(con_handle); 3315 if (!connection) { 3316 log_error("no hci_connection for handle 0x%04x", con_handle); 3317 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 3318 } 3319 3320 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 3321 if (!channel) { 3322 return BTSTACK_MEMORY_ALLOC_FAILED; 3323 } 3324 log_info("l2cap_le_create_channel %p", channel); 3325 3326 // store local_cid 3327 if (out_local_cid){ 3328 *out_local_cid = channel->local_cid; 3329 } 3330 3331 // provide buffer 3332 channel->con_handle = con_handle; 3333 channel->receive_sdu_buffer = receive_sdu_buffer; 3334 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 3335 channel->new_credits_incoming = initial_credits; 3336 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 3337 3338 // add to connections list 3339 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 3340 3341 // go 3342 l2cap_run(); 3343 return 0; 3344 } 3345 3346 /** 3347 * @brief Provide credtis for LE Data Channel 3348 * @param local_cid L2CAP LE Data Channel Identifier 3349 * @param credits Number additional credits for peer 3350 */ 3351 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 3352 3353 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3354 if (!channel) { 3355 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 3356 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3357 } 3358 3359 // check state 3360 if (channel->state != L2CAP_STATE_OPEN){ 3361 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 3362 } 3363 3364 // assert incoming credits + credits <= 0xffff 3365 uint32_t total_credits = channel->credits_incoming; 3366 total_credits += channel->new_credits_incoming; 3367 total_credits += credits; 3368 if (total_credits > 0xffff){ 3369 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 3370 channel->new_credits_incoming, credits); 3371 } 3372 3373 // set credits_granted 3374 channel->new_credits_incoming += credits; 3375 3376 // go 3377 l2cap_run(); 3378 return 0; 3379 } 3380 3381 /** 3382 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 3383 * @param local_cid L2CAP LE Data Channel Identifier 3384 */ 3385 int l2cap_le_can_send_now(uint16_t local_cid){ 3386 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3387 if (!channel) { 3388 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 3389 return 0; 3390 } 3391 3392 // check state 3393 if (channel->state != L2CAP_STATE_OPEN) return 0; 3394 3395 // check queue 3396 if (channel->send_sdu_buffer) return 0; 3397 3398 // fine, go ahead 3399 return 1; 3400 } 3401 3402 /** 3403 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 3404 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 3405 * so packet handler should be ready to handle it 3406 * @param local_cid L2CAP LE Data Channel Identifier 3407 */ 3408 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 3409 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3410 if (!channel) { 3411 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 3412 return 0; 3413 } 3414 channel->waiting_for_can_send_now = 1; 3415 l2cap_le_notify_channel_can_send(channel); 3416 return 0; 3417 } 3418 3419 /** 3420 * @brief Send data via LE Data Channel 3421 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 3422 * @param local_cid L2CAP LE Data Channel Identifier 3423 * @param data data to send 3424 * @param size data size 3425 */ 3426 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 3427 3428 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3429 if (!channel) { 3430 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 3431 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3432 } 3433 3434 if (len > channel->remote_mtu){ 3435 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 3436 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 3437 } 3438 3439 if (channel->send_sdu_buffer){ 3440 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 3441 return BTSTACK_ACL_BUFFERS_FULL; 3442 } 3443 3444 channel->send_sdu_buffer = data; 3445 channel->send_sdu_len = len; 3446 channel->send_sdu_pos = 0; 3447 3448 l2cap_run(); 3449 return 0; 3450 } 3451 3452 /** 3453 * @brief Disconnect from LE Data Channel 3454 * @param local_cid L2CAP LE Data Channel Identifier 3455 */ 3456 uint8_t l2cap_le_disconnect(uint16_t local_cid) 3457 { 3458 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3459 if (!channel) { 3460 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 3461 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3462 } 3463 3464 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3465 l2cap_run(); 3466 return 0; 3467 } 3468 3469 #endif 3470