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 #include <stdarg.h> 57 #include <string.h> 58 59 #include <stdio.h> 60 61 // nr of buffered acl packets in outgoing queue to get max performance 62 #define NR_BUFFERED_ACL_PACKETS 3 63 64 // used to cache l2cap rejects, echo, and informational requests 65 #define NR_PENDING_SIGNALING_RESPONSES 3 66 67 // nr of credits provided to remote if credits fall below watermark 68 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK 5 69 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT 5 70 71 // offsets for L2CAP SIGNALING COMMANDS 72 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 73 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 74 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 75 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 76 77 #if defined(ENABLE_LE_DATA_CHANNELS) || defined(ENABLE_CLASSIC) 78 #define L2CAP_USES_CHANNELS 79 #endif 80 81 // prototypes 82 static void l2cap_run(void); 83 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 84 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ); 85 static void l2cap_notify_channel_can_send(void); 86 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel); 87 static l2cap_fixed_channel_t * l2cap_fixed_channel_for_channel_id(uint16_t local_cid); 88 #ifdef ENABLE_CLASSIC 89 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel); 90 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel); 91 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 92 static inline l2cap_service_t * l2cap_get_service(uint16_t psm); 93 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 94 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 95 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel); 96 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 97 #endif 98 #ifdef ENABLE_LE_DATA_CHANNELS 99 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status); 100 static void l2cap_emit_le_channel_closed(l2cap_channel_t * channel); 101 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel); 102 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel); 103 static void l2cap_le_finialize_channel_close(l2cap_channel_t *channel); 104 static inline l2cap_service_t * l2cap_le_get_service(uint16_t psm); 105 #endif 106 #ifdef L2CAP_USES_CHANNELS 107 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size); 108 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid); 109 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, l2cap_channel_type_t channel_type, bd_addr_t address, bd_addr_type_t address_type, 110 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level); 111 #endif 112 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 113 static void l2cap_ertm_notify_channel_can_send(l2cap_channel_t * channel); 114 static void l2cap_ertm_monitor_timeout_callback(btstack_timer_source_t * ts); 115 static void l2cap_ertm_retransmission_timeout_callback(btstack_timer_source_t * ts); 116 #endif 117 118 // l2cap_fixed_channel_t entries 119 #ifdef ENABLE_BLE 120 static l2cap_fixed_channel_t l2cap_fixed_channel_att; 121 static l2cap_fixed_channel_t l2cap_fixed_channel_sm; 122 #endif 123 #ifdef ENABLE_CLASSIC 124 static l2cap_fixed_channel_t l2cap_fixed_channel_connectionless; 125 #endif 126 127 #ifdef ENABLE_CLASSIC 128 static btstack_linked_list_t l2cap_services; 129 static uint8_t require_security_level2_for_outgoing_sdp; 130 #endif 131 132 #ifdef ENABLE_LE_DATA_CHANNELS 133 static btstack_linked_list_t l2cap_le_services; 134 #endif 135 136 // single list of channels for Classic Channels, LE Data Channels, Classic Connectionless, ATT, and SM 137 static btstack_linked_list_t l2cap_channels; 138 139 // used to cache l2cap rejects, echo, and informational requests 140 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 141 static int signaling_responses_pending; 142 static btstack_packet_callback_registration_t hci_event_callback_registration; 143 144 #ifdef ENABLE_BLE 145 // only used for connection parameter update events 146 static btstack_packet_handler_t l2cap_event_packet_handler; 147 static uint16_t l2cap_le_custom_max_mtu; 148 #endif 149 150 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 151 152 /* 153 * CRC lookup table for generator polynom D^16 + D^15 + D^2 + 1 154 */ 155 static const uint16_t crc16_table[256] = { 156 0x0000, 0xc0c1, 0xc181, 0x0140, 0xc301, 0x03c0, 0x0280, 0xc241, 0xc601, 0x06c0, 0x0780, 0xc741, 0x0500, 0xc5c1, 0xc481, 0x0440, 157 0xcc01, 0x0cc0, 0x0d80, 0xcd41, 0x0f00, 0xcfc1, 0xce81, 0x0e40, 0x0a00, 0xcac1, 0xcb81, 0x0b40, 0xc901, 0x09c0, 0x0880, 0xc841, 158 0xd801, 0x18c0, 0x1980, 0xd941, 0x1b00, 0xdbc1, 0xda81, 0x1a40, 0x1e00, 0xdec1, 0xdf81, 0x1f40, 0xdd01, 0x1dc0, 0x1c80, 0xdc41, 159 0x1400, 0xd4c1, 0xd581, 0x1540, 0xd701, 0x17c0, 0x1680, 0xd641, 0xd201, 0x12c0, 0x1380, 0xd341, 0x1100, 0xd1c1, 0xd081, 0x1040, 160 0xf001, 0x30c0, 0x3180, 0xf141, 0x3300, 0xf3c1, 0xf281, 0x3240, 0x3600, 0xf6c1, 0xf781, 0x3740, 0xf501, 0x35c0, 0x3480, 0xf441, 161 0x3c00, 0xfcc1, 0xfd81, 0x3d40, 0xff01, 0x3fc0, 0x3e80, 0xfe41, 0xfa01, 0x3ac0, 0x3b80, 0xfb41, 0x3900, 0xf9c1, 0xf881, 0x3840, 162 0x2800, 0xe8c1, 0xe981, 0x2940, 0xeb01, 0x2bc0, 0x2a80, 0xea41, 0xee01, 0x2ec0, 0x2f80, 0xef41, 0x2d00, 0xedc1, 0xec81, 0x2c40, 163 0xe401, 0x24c0, 0x2580, 0xe541, 0x2700, 0xe7c1, 0xe681, 0x2640, 0x2200, 0xe2c1, 0xe381, 0x2340, 0xe101, 0x21c0, 0x2080, 0xe041, 164 0xa001, 0x60c0, 0x6180, 0xa141, 0x6300, 0xa3c1, 0xa281, 0x6240, 0x6600, 0xa6c1, 0xa781, 0x6740, 0xa501, 0x65c0, 0x6480, 0xa441, 165 0x6c00, 0xacc1, 0xad81, 0x6d40, 0xaf01, 0x6fc0, 0x6e80, 0xae41, 0xaa01, 0x6ac0, 0x6b80, 0xab41, 0x6900, 0xa9c1, 0xa881, 0x6840, 166 0x7800, 0xb8c1, 0xb981, 0x7940, 0xbb01, 0x7bc0, 0x7a80, 0xba41, 0xbe01, 0x7ec0, 0x7f80, 0xbf41, 0x7d00, 0xbdc1, 0xbc81, 0x7c40, 167 0xb401, 0x74c0, 0x7580, 0xb541, 0x7700, 0xb7c1, 0xb681, 0x7640, 0x7200, 0xb2c1, 0xb381, 0x7340, 0xb101, 0x71c0, 0x7080, 0xb041, 168 0x5000, 0x90c1, 0x9181, 0x5140, 0x9301, 0x53c0, 0x5280, 0x9241, 0x9601, 0x56c0, 0x5780, 0x9741, 0x5500, 0x95c1, 0x9481, 0x5440, 169 0x9c01, 0x5cc0, 0x5d80, 0x9d41, 0x5f00, 0x9fc1, 0x9e81, 0x5e40, 0x5a00, 0x9ac1, 0x9b81, 0x5b40, 0x9901, 0x59c0, 0x5880, 0x9841, 170 0x8801, 0x48c0, 0x4980, 0x8941, 0x4b00, 0x8bc1, 0x8a81, 0x4a40, 0x4e00, 0x8ec1, 0x8f81, 0x4f40, 0x8d01, 0x4dc0, 0x4c80, 0x8c41, 171 0x4400, 0x84c1, 0x8581, 0x4540, 0x8701, 0x47c0, 0x4680, 0x8641, 0x8201, 0x42c0, 0x4380, 0x8341, 0x4100, 0x81c1, 0x8081, 0x4040, 172 }; 173 174 static uint16_t crc16_calc(uint8_t * data, uint16_t len){ 175 uint16_t crc = 0; // initial value = 0 176 while (len--){ 177 crc = (crc >> 8) ^ crc16_table[ (crc ^ ((uint16_t) *data++)) & 0x00FF ]; 178 } 179 return crc; 180 } 181 182 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){ 183 return (((uint16_t) sar) << 14) | (req_seq << 8) | (final << 7) | (tx_seq << 1) | 0; 184 } 185 186 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){ 187 return (req_seq << 8) | (final << 7) | (poll << 4) | (((int) supervisory_function) << 2) | 1; 188 } 189 190 static int l2cap_next_ertm_seq_nr(int seq_nr){ 191 return (seq_nr + 1) & 0x3f; 192 } 193 194 static int l2cap_ertm_can_store_packet_now(l2cap_channel_t * channel){ 195 // get num free tx buffers 196 int num_tx_buffers_used = channel->tx_write_index - channel->tx_read_index; 197 if (num_tx_buffers_used < 0){ 198 num_tx_buffers_used += channel->num_tx_buffers; 199 } 200 int num_free_tx_buffers = channel->num_tx_buffers - num_tx_buffers_used; 201 // calculate num tx buffers for remote MTU 202 int num_tx_buffers_for_max_remote_mtu; 203 if (channel->remote_mtu <= channel->remote_mps){ 204 // MTU fits into single packet 205 num_tx_buffers_for_max_remote_mtu = 1; 206 } else { 207 // include SDU Length 208 num_tx_buffers_for_max_remote_mtu = (channel->remote_mtu + 2 + (channel->remote_mps - 1)) / channel->remote_mps; 209 } 210 return num_tx_buffers_for_max_remote_mtu <= num_free_tx_buffers; 211 } 212 213 static void l2cap_ertm_next_tx_write_index(l2cap_channel_t * channel){ 214 channel->tx_write_index++; 215 if (channel->tx_write_index < channel->num_tx_buffers) return; 216 channel->tx_write_index = 0; 217 } 218 219 static void l2cap_ertm_start_monitor_timer(l2cap_channel_t * channel){ 220 log_info("Start Monitor timer"); 221 btstack_run_loop_remove_timer(&channel->monitor_timer); 222 btstack_run_loop_set_timer_handler(&channel->monitor_timer, &l2cap_ertm_monitor_timeout_callback); 223 btstack_run_loop_set_timer_context(&channel->monitor_timer, channel); 224 btstack_run_loop_set_timer(&channel->monitor_timer, channel->local_monitor_timeout_ms); 225 btstack_run_loop_add_timer(&channel->monitor_timer); 226 } 227 228 static void l2cap_ertm_stop_monitor_timer(l2cap_channel_t * channel){ 229 log_info("Stop Monitor timer"); 230 btstack_run_loop_remove_timer(&channel->monitor_timer); 231 } 232 233 static void l2cap_ertm_start_retransmission_timer(l2cap_channel_t * channel){ 234 log_info("Start Retransmission timer"); 235 btstack_run_loop_remove_timer(&channel->retransmission_timer); 236 btstack_run_loop_set_timer_handler(&channel->retransmission_timer, &l2cap_ertm_retransmission_timeout_callback); 237 btstack_run_loop_set_timer_context(&channel->retransmission_timer, channel); 238 btstack_run_loop_set_timer(&channel->retransmission_timer, channel->local_retransmission_timeout_ms); 239 btstack_run_loop_add_timer(&channel->retransmission_timer); 240 } 241 242 static void l2cap_ertm_stop_retransmission_timer(l2cap_channel_t * l2cap_channel){ 243 log_info("Stop Retransmission timer"); 244 btstack_run_loop_remove_timer(&l2cap_channel->retransmission_timer); 245 } 246 247 static void l2cap_ertm_monitor_timeout_callback(btstack_timer_source_t * ts){ 248 log_info("Monitor timeout"); 249 l2cap_channel_t * l2cap_channel = (l2cap_channel_t *) btstack_run_loop_get_timer_context(ts); 250 251 // TODO: we assume that it's the oldest packet 252 l2cap_ertm_tx_packet_state_t * tx_state; 253 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 254 255 // check retry count 256 if (tx_state->retry_count < l2cap_channel->remote_max_transmit){ 257 // increment retry count 258 tx_state->retry_count++; 259 260 l2cap_ertm_start_monitor_timer(l2cap_channel); 261 262 // send RR/P=1 263 l2cap_channel->send_supervisor_frame_receiver_ready_poll = 1; 264 } else { 265 log_info("Monitor timer expired & retry count >= max transmit -> disconnect"); 266 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 267 } 268 l2cap_run(); 269 } 270 271 static void l2cap_ertm_retransmission_timeout_callback(btstack_timer_source_t * ts){ 272 log_info("Retransmission timeout"); 273 l2cap_channel_t * l2cap_channel = (l2cap_channel_t *) btstack_run_loop_get_timer_context(ts); 274 275 // TODO: we assume that it's the oldest packet 276 l2cap_ertm_tx_packet_state_t * tx_state; 277 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 278 279 // set retry count = 1 280 tx_state->retry_count = 1; 281 282 // start monitor timer 283 l2cap_ertm_start_monitor_timer(l2cap_channel); 284 285 // send RR/P=1 286 l2cap_channel->send_supervisor_frame_receiver_ready_poll = 1; 287 l2cap_run(); 288 } 289 290 static int l2cap_ertm_send_information_frame(l2cap_channel_t * channel, int index, int final){ 291 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[index]; 292 hci_reserve_packet_buffer(); 293 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 294 uint16_t control = l2cap_encanced_control_field_for_information_frame(tx_state->tx_seq, final, channel->req_seq, tx_state->sar); 295 log_info("I-Frame: control 0x%04x", control); 296 little_endian_store_16(acl_buffer, 8, control); 297 memcpy(&acl_buffer[8+2], &channel->tx_packets_data[index * channel->local_mtu], tx_state->len); 298 // (re-)start retransmission timer on 299 l2cap_ertm_start_retransmission_timer(channel); 300 // send 301 return l2cap_send_prepared(channel->local_cid, 2 + tx_state->len); 302 } 303 304 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){ 305 // get next index for storing packets 306 int index = channel->tx_write_index; 307 308 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[index]; 309 tx_state->tx_seq = channel->next_tx_seq; 310 tx_state->len = len; 311 tx_state->sar = sar; 312 tx_state->retry_count = 0; 313 314 uint8_t * tx_packet = &channel->tx_packets_data[index * channel->local_mtu]; 315 int pos = 0; 316 if (sar == L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU){ 317 little_endian_store_16(tx_packet, 0, sdu_length); 318 pos += 2; 319 } 320 memcpy(&tx_packet[pos], data, len); 321 322 // update 323 channel->next_tx_seq = l2cap_next_ertm_seq_nr(channel->next_tx_seq); 324 l2cap_ertm_next_tx_write_index(channel); 325 326 log_info("l2cap_ertm_store_fragment: after store, tx_read_index %u, tx_write_index %u", channel->tx_read_index, channel->tx_write_index); 327 328 } 329 330 static int l2cap_ertm_send(l2cap_channel_t * channel, uint8_t * data, uint16_t len){ 331 if (len > channel->remote_mtu){ 332 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", channel->local_cid); 333 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 334 } 335 336 // check if it needs to get fragmented 337 if (len > channel->remote_mps){ 338 // fragmentation needed. 339 l2cap_segmentation_and_reassembly_t sar = L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU; 340 int chunk_len; 341 while (len){ 342 switch (sar){ 343 case L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU: 344 chunk_len = channel->remote_mps - 2; // sdu_length 345 l2cap_ertm_store_fragment(channel, sar, len, data, chunk_len); 346 len -= chunk_len; 347 sar = L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU; 348 break; 349 case L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU: 350 chunk_len = channel->remote_mps; 351 if (chunk_len >= len){ 352 sar = L2CAP_SEGMENTATION_AND_REASSEMBLY_END_OF_L2CAP_SDU; 353 chunk_len = len; 354 } 355 l2cap_ertm_store_fragment(channel, sar, len, data, chunk_len); 356 len -= chunk_len; 357 break; 358 default: 359 break; 360 } 361 } 362 363 } else { 364 l2cap_ertm_store_fragment(channel, L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU, 0, data, len); 365 } 366 367 // try to send 368 l2cap_run(); 369 return 0; 370 } 371 372 static uint16_t l2cap_setup_options_ertm_request(l2cap_channel_t * channel, uint8_t * config_options){ 373 int pos = 0; 374 config_options[pos++] = L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL; 375 config_options[pos++] = 9; // length 376 config_options[pos++] = (uint8_t) channel->mode; 377 config_options[pos++] = channel->num_rx_buffers; // == TxWindows size 378 config_options[pos++] = channel->local_max_transmit; 379 little_endian_store_16( config_options, pos, channel->local_retransmission_timeout_ms); 380 pos += 2; 381 little_endian_store_16( config_options, pos, channel->local_monitor_timeout_ms); 382 pos += 2; 383 little_endian_store_16( config_options, pos, channel->local_mps); 384 pos += 2; 385 // 386 config_options[pos++] = L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT; 387 config_options[pos++] = 2; // length 388 little_endian_store_16(config_options, pos, channel->local_mtu); 389 pos += 2; 390 // 391 config_options[pos++] = L2CAP_CONFIG_OPTION_TYPE_FRAME_CHECK_SEQUENCE; 392 config_options[pos++] = 1; // length 393 config_options[pos++] = channel->fcs_option; 394 return pos; // 11+4+3=18 395 } 396 397 static uint16_t l2cap_setup_options_ertm_response(l2cap_channel_t * channel, uint8_t * config_options){ 398 int pos = 0; 399 config_options[pos++] = L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL; 400 config_options[pos++] = 9; // length 401 config_options[pos++] = (uint8_t) channel->mode; 402 // less or equal to remote tx window size 403 config_options[pos++] = btstack_min(channel->num_tx_buffers, channel->remote_tx_window_size); 404 // max transmit in response shall be ignored -> use sender values 405 config_options[pos++] = channel->remote_max_transmit; 406 // A value for the Retransmission time-out shall be sent in a positive Configuration Response 407 // and indicates the value that will be used by the sender of the Configuration Response -> use our value 408 little_endian_store_16( config_options, pos, channel->local_retransmission_timeout_ms); 409 pos += 2; 410 // A value for the Monitor time-out shall be sent in a positive Configuration Response 411 // and indicates the value that will be used by the sender of the Configuration Response -> use our value 412 little_endian_store_16( config_options, pos, channel->local_monitor_timeout_ms); 413 pos += 2; 414 // less or equal to remote mps 415 little_endian_store_16( config_options, pos, btstack_min(channel->local_mps, channel->remote_mps)); 416 pos += 2; 417 // 418 config_options[pos++] = L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT; // MTU 419 config_options[pos++] = 2; // length 420 little_endian_store_16(config_options, pos, channel->remote_mtu); 421 pos += 2; 422 #if 0 423 // 424 config_options[pos++] = L2CAP_CONFIG_OPTION_TYPE_FRAME_CHECK_SEQUENCE; 425 config_options[pos++] = 1; // length 426 config_options[pos++] = channel->fcs_option; 427 #endif 428 return pos; // 11+4=15 429 } 430 431 static int l2cap_ertm_send_supervisor_frame(l2cap_channel_t * channel, uint16_t control){ 432 hci_reserve_packet_buffer(); 433 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 434 log_info("S-Frame: control 0x%04x", control); 435 little_endian_store_16(acl_buffer, 8, control); 436 return l2cap_send_prepared(channel->local_cid, 2); 437 } 438 439 static uint8_t l2cap_ertm_validate_local_config(l2cap_ertm_config_t * ertm_config){ 440 441 uint8_t result = ERROR_CODE_SUCCESS; 442 if (ertm_config->max_transmit < 1){ 443 log_error("max_transmit must be >= 1"); 444 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 445 } 446 if (ertm_config->retransmission_timeout_ms < 2000){ 447 log_error("retransmission_timeout_ms must be >= 2000 ms"); 448 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 449 } 450 if (ertm_config->monitor_timeout_ms < 12000){ 451 log_error("monitor_timeout_ms must be >= 12000 ms"); 452 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 453 } 454 if (ertm_config->local_mtu < 48){ 455 log_error("local_mtu must be >= 48"); 456 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 457 } 458 if (ertm_config->num_rx_buffers < 1){ 459 log_error("num_rx_buffers must be >= 1"); 460 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 461 } 462 if (ertm_config->num_tx_buffers < 1){ 463 log_error("num_rx_buffers must be >= 1"); 464 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 465 } 466 return result; 467 } 468 469 static void l2cap_ertm_configure_channel(l2cap_channel_t * channel, l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size){ 470 471 channel->mode = L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION; 472 channel->ertm_mandatory = ertm_config->ertm_mandatory; 473 channel->local_max_transmit = ertm_config->max_transmit; 474 channel->local_retransmission_timeout_ms = ertm_config->retransmission_timeout_ms; 475 channel->local_monitor_timeout_ms = ertm_config->monitor_timeout_ms; 476 channel->local_mtu = ertm_config->local_mtu; 477 channel->num_rx_buffers = ertm_config->num_rx_buffers; 478 channel->num_tx_buffers = ertm_config->num_tx_buffers; 479 480 // align buffer to 16-byte boundary, just in case 481 int bytes_till_alignment = 16 - (((uintptr_t) buffer) & 0x0f); 482 buffer += bytes_till_alignment; 483 size -= bytes_till_alignment; 484 485 // setup state buffers 486 uint32_t pos = 0; 487 channel->rx_packets_state = (l2cap_ertm_rx_packet_state_t *) &buffer[pos]; 488 pos += ertm_config->num_rx_buffers * sizeof(l2cap_ertm_rx_packet_state_t); 489 channel->tx_packets_state = (l2cap_ertm_tx_packet_state_t *) &buffer[pos]; 490 pos += ertm_config->num_tx_buffers * sizeof(l2cap_ertm_tx_packet_state_t); 491 492 // setup reassembly buffer 493 channel->reassembly_buffer = &buffer[pos]; 494 pos += ertm_config->local_mtu; 495 496 // divide rest of data equally 497 channel->local_mps = (size - pos) / (ertm_config->num_rx_buffers + ertm_config->num_tx_buffers); 498 log_info("Local MPS: %u", channel->local_mps); 499 channel->rx_packets_data = &buffer[pos]; 500 pos += ertm_config->num_rx_buffers * channel->local_mps; 501 channel->tx_packets_data = &buffer[pos]; 502 503 // Issue: iOS (e.g. 10.2) uses "No FCS" as default while Core 5.0 specifies "FCS" as default 504 // Workaround: try to actively negotiate "No FCS" and fall back to "FCS" if "No FCS" is rejected 505 // This works as iOS accepts the "No FCS" request, hence the default value is only used on non-iOS devices 506 channel->fcs_option = 0; 507 } 508 509 uint8_t l2cap_create_ertm_channel(btstack_packet_handler_t packet_handler, bd_addr_t address, uint16_t psm, 510 l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size, uint16_t * out_local_cid){ 511 512 log_info("L2CAP_CREATE_ERTM_CHANNEL addr %s, psm 0x%x, local mtu %u", bd_addr_to_str(address), psm, ertm_config->local_mtu); 513 514 // validate local config 515 uint8_t result = l2cap_ertm_validate_local_config(ertm_config); 516 if (result) return result; 517 518 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, L2CAP_CHANNEL_TYPE_CLASSIC, address, BD_ADDR_TYPE_CLASSIC, psm, ertm_config->local_mtu, LEVEL_0); 519 if (!channel) { 520 return BTSTACK_MEMORY_ALLOC_FAILED; 521 } 522 523 // configure ERTM 524 l2cap_ertm_configure_channel(channel, ertm_config, buffer, size); 525 526 // add to connections list 527 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 528 529 // store local_cid 530 if (out_local_cid){ 531 *out_local_cid = channel->local_cid; 532 } 533 534 // check if hci connection is already usable 535 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 536 if (conn){ 537 log_info("l2cap_create_channel, hci connection already exists"); 538 l2cap_handle_connection_complete(conn->con_handle, channel); 539 // check if remote supported fearures are already received 540 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 541 l2cap_handle_remote_supported_features_received(channel); 542 } 543 } 544 545 l2cap_run(); 546 547 return 0; 548 } 549 550 static void l2cap_ertm_notify_channel_can_send(l2cap_channel_t * channel){ 551 if (l2cap_ertm_can_store_packet_now(channel)){ 552 channel->waiting_for_can_send_now = 0; 553 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 554 } 555 } 556 557 uint8_t l2cap_accept_ertm_connection(uint16_t local_cid, l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size){ 558 559 log_info("L2CAP_ACCEPT_ERTM_CONNECTION local_cid 0x%x", local_cid); 560 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 561 if (!channel) { 562 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 563 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 564 } 565 566 // validate local config 567 uint8_t result = l2cap_ertm_validate_local_config(ertm_config); 568 if (result) return result; 569 570 // configure L2CAP ERTM 571 l2cap_ertm_configure_channel(channel, ertm_config, buffer, size); 572 573 // continue 574 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 575 576 // process 577 l2cap_run(); 578 579 return ERROR_CODE_SUCCESS; 580 } 581 582 uint8_t l2cap_ertm_set_busy(uint16_t local_cid){ 583 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 584 if (!channel) { 585 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 586 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 587 } 588 if (!channel->local_busy){ 589 channel->local_busy = 1; 590 channel->send_supervisor_frame_receiver_not_ready = 1; 591 l2cap_run(); 592 } 593 return ERROR_CODE_SUCCESS; 594 } 595 596 uint8_t l2cap_ertm_set_ready(uint16_t local_cid){ 597 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 598 if (!channel) { 599 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 600 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 601 } 602 if (channel->local_busy){ 603 channel->local_busy = 0; 604 channel->send_supervisor_frame_receiver_ready_poll = 1; 605 l2cap_run(); 606 } 607 return ERROR_CODE_SUCCESS; 608 } 609 610 // Process-ReqSeq 611 static void l2cap_ertm_process_req_seq(l2cap_channel_t * l2cap_channel, uint8_t req_seq){ 612 int num_buffers_acked = 0; 613 l2cap_ertm_tx_packet_state_t * tx_state; 614 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); 615 while (1){ 616 617 // no unack packets left 618 if (l2cap_channel->unacked_frames == 0) { 619 // stop retransmission timer 620 l2cap_ertm_stop_retransmission_timer(l2cap_channel); 621 break; 622 } 623 624 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 625 // calc delta 626 int delta = (req_seq - tx_state->tx_seq) & 0x03f; 627 if (delta == 0) break; // all packets acknowledged 628 if (delta > l2cap_channel->remote_tx_window_size) break; 629 630 num_buffers_acked++; 631 l2cap_channel->unacked_frames--; 632 log_info("RR seq %u => packet with tx_seq %u done", req_seq, tx_state->tx_seq); 633 634 l2cap_channel->tx_read_index++; 635 if (l2cap_channel->tx_read_index >= l2cap_channel->num_rx_buffers){ 636 l2cap_channel->tx_read_index = 0; 637 } 638 } 639 640 if (num_buffers_acked){ 641 l2cap_ertm_notify_channel_can_send(l2cap_channel); 642 } 643 } 644 645 static l2cap_ertm_tx_packet_state_t * l2cap_ertm_get_tx_state(l2cap_channel_t * l2cap_channel, uint8_t tx_seq){ 646 int i; 647 for (i=0;i<l2cap_channel->num_tx_buffers;i++){ 648 l2cap_ertm_tx_packet_state_t * tx_state = &l2cap_channel->tx_packets_state[i]; 649 if (tx_state->tx_seq == tx_seq) return tx_state; 650 } 651 return NULL; 652 } 653 654 // @param delta number of frames in the future, >= 1 655 // @assumption size <= l2cap_channel->local_mps (checked in l2cap_acl_classic_handler) 656 static void l2cap_ertm_handle_out_of_sequence_sdu(l2cap_channel_t * l2cap_channel, l2cap_segmentation_and_reassembly_t sar, int delta, const uint8_t * payload, uint16_t size){ 657 log_info("Store SDU with delta %u", delta); 658 // get rx state for packet to store 659 int index = l2cap_channel->rx_store_index + delta - 1; 660 if (index > l2cap_channel->num_rx_buffers){ 661 index -= l2cap_channel->num_rx_buffers; 662 } 663 log_info("Index of packet to store %u", index); 664 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 665 // check if buffer is free 666 if (rx_state->valid){ 667 log_error("Packet buffer already used"); 668 return; 669 } 670 rx_state->valid = 1; 671 rx_state->sar = sar; 672 rx_state->len = size; 673 uint8_t * rx_buffer = &l2cap_channel->rx_packets_data[index]; 674 memcpy(rx_buffer, payload, size); 675 } 676 677 // @assumption size <= l2cap_channel->local_mps (checked in l2cap_acl_classic_handler) 678 static void l2cap_ertm_handle_in_sequence_sdu(l2cap_channel_t * l2cap_channel, l2cap_segmentation_and_reassembly_t sar, const uint8_t * payload, uint16_t size){ 679 uint16_t reassembly_sdu_length; 680 switch (sar){ 681 case L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU: 682 // assert total packet size <= our mtu 683 if (size > l2cap_channel->local_mtu) break; 684 // packet complete -> disapatch 685 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, (uint8_t*) payload, size); 686 break; 687 case L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU: 688 // read SDU len 689 reassembly_sdu_length = little_endian_read_16(payload, 0); 690 payload += 2; 691 size -= 2; 692 // assert reassembled size <= our mtu 693 if (reassembly_sdu_length > l2cap_channel->local_mtu) break; 694 // store start segment 695 l2cap_channel->reassembly_sdu_length = reassembly_sdu_length; 696 memcpy(&l2cap_channel->reassembly_buffer[0], payload, size); 697 l2cap_channel->reassembly_pos = size; 698 break; 699 case L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU: 700 // assert size of reassembled data <= our mtu 701 if (l2cap_channel->reassembly_pos + size > l2cap_channel->local_mtu) break; 702 // store continuation segment 703 memcpy(&l2cap_channel->reassembly_buffer[l2cap_channel->reassembly_pos], payload, size); 704 l2cap_channel->reassembly_pos += size; 705 break; 706 case L2CAP_SEGMENTATION_AND_REASSEMBLY_END_OF_L2CAP_SDU: 707 // assert size of reassembled data <= our mtu 708 if (l2cap_channel->reassembly_pos + size > l2cap_channel->local_mtu) break; 709 // store continuation segment 710 memcpy(&l2cap_channel->reassembly_buffer[l2cap_channel->reassembly_pos], payload, size); 711 l2cap_channel->reassembly_pos += size; 712 // assert size of reassembled data matches announced sdu length 713 if (l2cap_channel->reassembly_pos != l2cap_channel->reassembly_sdu_length) break; 714 // packet complete -> disapatch 715 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->reassembly_buffer, l2cap_channel->reassembly_pos); 716 l2cap_channel->reassembly_pos = 0; 717 break; 718 } 719 } 720 721 #endif 722 723 void l2cap_init(void){ 724 signaling_responses_pending = 0; 725 726 l2cap_channels = NULL; 727 728 #ifdef ENABLE_CLASSIC 729 l2cap_services = NULL; 730 require_security_level2_for_outgoing_sdp = 0; 731 732 // Setup Connectionless Channel 733 l2cap_fixed_channel_connectionless.local_cid = L2CAP_CID_CONNECTIONLESS_CHANNEL; 734 l2cap_fixed_channel_connectionless.channel_type = L2CAP_CHANNEL_TYPE_CONNECTIONLESS; 735 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) &l2cap_fixed_channel_connectionless); 736 #endif 737 738 #ifdef ENABLE_LE_DATA_CHANNELS 739 l2cap_le_services = NULL; 740 #endif 741 742 #ifdef ENABLE_BLE 743 l2cap_event_packet_handler = NULL; 744 l2cap_le_custom_max_mtu = 0; 745 746 // Setup fixed ATT Channel 747 l2cap_fixed_channel_att.local_cid = L2CAP_CID_ATTRIBUTE_PROTOCOL; 748 l2cap_fixed_channel_att.channel_type = L2CAP_CHANNEL_TYPE_LE_FIXED; 749 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) &l2cap_fixed_channel_att); 750 751 // Setup fixed SM Channel 752 l2cap_fixed_channel_sm.local_cid = L2CAP_CID_SECURITY_MANAGER_PROTOCOL; 753 l2cap_fixed_channel_sm.channel_type = L2CAP_CHANNEL_TYPE_LE_FIXED; 754 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) &l2cap_fixed_channel_sm); 755 #endif 756 757 // 758 // register callback with HCI 759 // 760 hci_event_callback_registration.callback = &l2cap_hci_event_handler; 761 hci_add_event_handler(&hci_event_callback_registration); 762 763 hci_register_acl_packet_handler(&l2cap_acl_handler); 764 765 #ifdef ENABLE_CLASSIC 766 gap_connectable_control(0); // no services yet 767 #endif 768 } 769 770 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 771 #ifdef ENABLE_BLE 772 l2cap_event_packet_handler = handler; 773 #else 774 UNUSED(handler); // ok: no code 775 #endif 776 } 777 778 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ 779 UNUSED(con_handle); // ok: there is no con handle 780 781 l2cap_fixed_channel_t * channel = l2cap_fixed_channel_for_channel_id(channel_id); 782 if (!channel) return; 783 channel->waiting_for_can_send_now = 1; 784 l2cap_notify_channel_can_send(); 785 } 786 787 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ 788 UNUSED(channel_id); // ok: only depends on Controller LE buffers 789 790 return hci_can_send_acl_packet_now(con_handle); 791 } 792 793 uint8_t *l2cap_get_outgoing_buffer(void){ 794 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 795 } 796 797 int l2cap_reserve_packet_buffer(void){ 798 return hci_reserve_packet_buffer(); 799 } 800 801 void l2cap_release_packet_buffer(void){ 802 hci_release_packet_buffer(); 803 } 804 805 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){ 806 // 0 - Connection handle : PB=pb : BC=00 807 little_endian_store_16(acl_buffer, 0, con_handle | (packet_boundary << 12) | (0 << 14)); 808 // 2 - ACL length 809 little_endian_store_16(acl_buffer, 2, len + 4); 810 // 4 - L2CAP packet length 811 little_endian_store_16(acl_buffer, 4, len + 0); 812 // 6 - L2CAP channel DEST 813 little_endian_store_16(acl_buffer, 6, remote_cid); 814 } 815 816 // assumption - only on LE connections 817 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 818 819 if (!hci_is_packet_buffer_reserved()){ 820 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 821 return BTSTACK_ACL_BUFFERS_FULL; 822 } 823 824 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 825 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 826 return BTSTACK_ACL_BUFFERS_FULL; 827 } 828 829 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 830 831 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 832 l2cap_setup_header(acl_buffer, con_handle, 0, cid, len); 833 // send 834 return hci_send_acl_packet_buffer(len+8); 835 } 836 837 // assumption - only on LE connections 838 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 839 840 if (!hci_can_send_acl_packet_now(con_handle)){ 841 log_info("l2cap_send cid 0x%02x, cannot send", cid); 842 return BTSTACK_ACL_BUFFERS_FULL; 843 } 844 845 hci_reserve_packet_buffer(); 846 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 847 848 memcpy(&acl_buffer[8], data, len); 849 850 return l2cap_send_prepared_connectionless(con_handle, cid, len); 851 } 852 853 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { 854 log_debug("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); 855 uint8_t event[4]; 856 event[0] = L2CAP_EVENT_CAN_SEND_NOW; 857 event[1] = sizeof(event) - 2; 858 little_endian_store_16(event, 2, channel); 859 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 860 packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); 861 } 862 863 #ifdef L2CAP_USES_CHANNELS 864 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 865 (* (channel->packet_handler))(type, channel->local_cid, data, size); 866 } 867 868 static void l2cap_emit_simple_event_with_cid(l2cap_channel_t * channel, uint8_t event_code){ 869 uint8_t event[4]; 870 event[0] = event_code; 871 event[1] = sizeof(event) - 2; 872 little_endian_store_16(event, 2, channel->local_cid); 873 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 874 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 875 } 876 #endif 877 878 #ifdef ENABLE_CLASSIC 879 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 880 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", 881 status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 882 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 883 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 884 log_info("ERTM mode %u, fcs enabled %u", channel->mode, channel->fcs_option); 885 #endif 886 uint8_t event[24]; 887 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 888 event[1] = sizeof(event) - 2; 889 event[2] = status; 890 reverse_bd_addr(channel->address, &event[3]); 891 little_endian_store_16(event, 9, channel->con_handle); 892 little_endian_store_16(event, 11, channel->psm); 893 little_endian_store_16(event, 13, channel->local_cid); 894 little_endian_store_16(event, 15, channel->remote_cid); 895 little_endian_store_16(event, 17, channel->local_mtu); 896 little_endian_store_16(event, 19, channel->remote_mtu); 897 little_endian_store_16(event, 21, channel->flush_timeout); 898 event[23] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 899 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 900 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 901 } 902 903 static void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 904 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 905 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 906 } 907 908 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel) { 909 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 910 bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); 911 uint8_t event[16]; 912 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 913 event[1] = sizeof(event) - 2; 914 reverse_bd_addr(channel->address, &event[2]); 915 little_endian_store_16(event, 8, channel->con_handle); 916 little_endian_store_16(event, 10, channel->psm); 917 little_endian_store_16(event, 12, channel->local_cid); 918 little_endian_store_16(event, 14, channel->remote_cid); 919 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 920 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 921 } 922 #endif 923 924 static l2cap_fixed_channel_t * l2cap_channel_item_by_cid(uint16_t cid){ 925 btstack_linked_list_iterator_t it; 926 btstack_linked_list_iterator_init(&it, &l2cap_channels); 927 while (btstack_linked_list_iterator_has_next(&it)){ 928 l2cap_fixed_channel_t * channel = (l2cap_fixed_channel_t*) btstack_linked_list_iterator_next(&it); 929 if (channel->local_cid == cid) { 930 return channel; 931 } 932 } 933 return NULL; 934 } 935 936 // used for fixed channels in LE (ATT/SM) and Classic (Connectionless Channel). CID < 0x04 937 static l2cap_fixed_channel_t * l2cap_fixed_channel_for_channel_id(uint16_t local_cid){ 938 if (local_cid >= 0x40) return NULL; 939 return (l2cap_fixed_channel_t*) l2cap_channel_item_by_cid(local_cid); 940 } 941 942 // used for Classic Channels + LE Data Channels. local_cid >= 0x40 943 #ifdef L2CAP_USES_CHANNELS 944 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 945 if (local_cid < 0x40) return NULL; 946 return (l2cap_channel_t*) l2cap_channel_item_by_cid(local_cid); 947 } 948 949 void l2cap_request_can_send_now_event(uint16_t local_cid){ 950 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 951 if (!channel) return; 952 channel->waiting_for_can_send_now = 1; 953 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 954 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 955 l2cap_ertm_notify_channel_can_send(channel); 956 return; 957 } 958 #endif 959 l2cap_notify_channel_can_send(); 960 } 961 962 int l2cap_can_send_packet_now(uint16_t local_cid){ 963 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 964 if (!channel) return 0; 965 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 966 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 967 return l2cap_ertm_can_store_packet_now(channel); 968 } 969 #endif 970 return hci_can_send_acl_packet_now(channel->con_handle); 971 } 972 973 int l2cap_can_send_prepared_packet_now(uint16_t local_cid){ 974 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 975 if (!channel) return 0; 976 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 977 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 978 return 0; 979 } 980 #endif 981 return hci_can_send_prepared_acl_packet_now(channel->con_handle); 982 } 983 984 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 985 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 986 if (channel) { 987 return channel->remote_mtu; 988 } 989 return 0; 990 } 991 #endif 992 993 #ifdef L2CAP_USES_CHANNELS 994 static int l2cap_is_dynamic_channel_type(l2cap_channel_type_t channel_type){ 995 switch (channel_type){ 996 case L2CAP_CHANNEL_TYPE_CLASSIC: 997 case L2CAP_CHANNEL_TYPE_LE_DATA_CHANNEL: 998 return 1; 999 default: 1000 return 0; 1001 } 1002 } 1003 #endif 1004 1005 static int l2cap_is_le_channel_type(l2cap_channel_type_t channel_type){ 1006 switch (channel_type){ 1007 case L2CAP_CHANNEL_TYPE_LE_FIXED: 1008 case L2CAP_CHANNEL_TYPE_LE_DATA_CHANNEL: 1009 return 1; 1010 default: 1011 return 0; 1012 } 1013 } 1014 1015 #ifdef ENABLE_CLASSIC 1016 // RTX Timer only exist for dynamic channels 1017 static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ 1018 btstack_linked_list_iterator_t it; 1019 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1020 while (btstack_linked_list_iterator_has_next(&it)){ 1021 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1022 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 1023 if (&channel->rtx == ts) { 1024 return channel; 1025 } 1026 } 1027 return NULL; 1028 } 1029 1030 static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ 1031 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 1032 if (!channel) return; 1033 1034 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 1035 1036 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 1037 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 1038 // notify client 1039 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 1040 1041 // discard channel 1042 // no need to stop timer here, it is removed from list during timer callback 1043 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1044 btstack_memory_l2cap_channel_free(channel); 1045 } 1046 1047 #endif 1048 1049 #ifdef L2CAP_USES_CHANNELS 1050 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 1051 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 1052 btstack_run_loop_remove_timer(&channel->rtx); 1053 } 1054 #endif 1055 1056 #ifdef ENABLE_CLASSIC 1057 1058 static void l2cap_start_rtx(l2cap_channel_t * channel){ 1059 l2cap_stop_rtx(channel); 1060 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 1061 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 1062 btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 1063 btstack_run_loop_add_timer(&channel->rtx); 1064 } 1065 1066 static void l2cap_start_ertx(l2cap_channel_t * channel){ 1067 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 1068 l2cap_stop_rtx(channel); 1069 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 1070 btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 1071 btstack_run_loop_add_timer(&channel->rtx); 1072 } 1073 1074 void l2cap_require_security_level_2_for_outgoing_sdp(void){ 1075 require_security_level2_for_outgoing_sdp = 1; 1076 } 1077 1078 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 1079 return (psm == BLUETOOTH_PROTOCOL_SDP) && (!require_security_level2_for_outgoing_sdp); 1080 } 1081 1082 static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, int identifier, ...){ 1083 if (!hci_can_send_acl_packet_now(handle)){ 1084 log_info("l2cap_send_signaling_packet, cannot send"); 1085 return BTSTACK_ACL_BUFFERS_FULL; 1086 } 1087 1088 // log_info("l2cap_send_signaling_packet type %u", cmd); 1089 hci_reserve_packet_buffer(); 1090 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1091 va_list argptr; 1092 va_start(argptr, identifier); 1093 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 1094 va_end(argptr); 1095 // log_info("l2cap_send_signaling_packet con %u!", handle); 1096 return hci_send_acl_packet_buffer(len); 1097 } 1098 1099 // assumption - only on Classic connections 1100 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 1101 1102 if (!hci_is_packet_buffer_reserved()){ 1103 log_error("l2cap_send_prepared called without reserving packet first"); 1104 return BTSTACK_ACL_BUFFERS_FULL; 1105 } 1106 1107 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1108 if (!channel) { 1109 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 1110 return -1; // TODO: define error 1111 } 1112 1113 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 1114 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 1115 return BTSTACK_ACL_BUFFERS_FULL; 1116 } 1117 1118 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 1119 1120 int fcs_size = 0; 1121 1122 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1123 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION && channel->fcs_option){ 1124 fcs_size = 2; 1125 } 1126 #endif 1127 1128 // set non-flushable packet boundary flag if supported on Controller 1129 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1130 uint8_t packet_boundary_flag = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 1131 l2cap_setup_header(acl_buffer, channel->con_handle, packet_boundary_flag, channel->remote_cid, len + fcs_size); 1132 1133 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1134 if (fcs_size){ 1135 // calculate FCS over l2cap data 1136 uint16_t fcs = crc16_calc(acl_buffer + 4, 4 + len); 1137 log_info("I-Frame: fcs 0x%04x", fcs); 1138 little_endian_store_16(acl_buffer, 8 + len, fcs); 1139 } 1140 #endif 1141 1142 // send 1143 return hci_send_acl_packet_buffer(len+8+fcs_size); 1144 } 1145 1146 // assumption - only on Classic connections 1147 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 1148 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1149 if (!channel) { 1150 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 1151 return -1; // TODO: define error 1152 } 1153 1154 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1155 // send in ERTM 1156 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1157 return l2cap_ertm_send(channel, data, len); 1158 } 1159 #endif 1160 1161 if (len > channel->remote_mtu){ 1162 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 1163 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 1164 } 1165 1166 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 1167 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 1168 return BTSTACK_ACL_BUFFERS_FULL; 1169 } 1170 1171 hci_reserve_packet_buffer(); 1172 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1173 memcpy(&acl_buffer[8], data, len); 1174 return l2cap_send_prepared(local_cid, len); 1175 } 1176 1177 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ 1178 return l2cap_send_signaling_packet(con_handle, ECHO_REQUEST, 0x77, len, data); 1179 } 1180 1181 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 1182 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 1183 } 1184 1185 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 1186 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 1187 } 1188 #endif 1189 1190 1191 #ifdef ENABLE_BLE 1192 static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, int identifier, ...){ 1193 1194 if (!hci_can_send_acl_packet_now(handle)){ 1195 log_info("l2cap_send_le_signaling_packet, cannot send"); 1196 return BTSTACK_ACL_BUFFERS_FULL; 1197 } 1198 1199 // log_info("l2cap_send_le_signaling_packet type %u", cmd); 1200 hci_reserve_packet_buffer(); 1201 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1202 va_list argptr; 1203 va_start(argptr, identifier); 1204 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 1205 va_end(argptr); 1206 // log_info("l2cap_send_le_signaling_packet con %u!", handle); 1207 return hci_send_acl_packet_buffer(len); 1208 } 1209 #endif 1210 1211 uint16_t l2cap_max_mtu(void){ 1212 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 1213 } 1214 1215 #ifdef ENABLE_BLE 1216 uint16_t l2cap_max_le_mtu(void){ 1217 if (l2cap_le_custom_max_mtu != 0) return l2cap_le_custom_max_mtu; 1218 return l2cap_max_mtu(); 1219 } 1220 1221 void l2cap_set_max_le_mtu(uint16_t max_mtu){ 1222 if (max_mtu < l2cap_max_mtu()){ 1223 l2cap_le_custom_max_mtu = max_mtu; 1224 } 1225 } 1226 #endif 1227 1228 #ifdef ENABLE_CLASSIC 1229 1230 static uint16_t l2cap_setup_options_mtu(uint8_t * config_options, uint16_t mtu){ 1231 config_options[0] = L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT; // MTU 1232 config_options[1] = 2; // len param 1233 little_endian_store_16(config_options, 2, mtu); 1234 return 4; 1235 } 1236 1237 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1238 static int l2cap_ertm_mode(l2cap_channel_t * channel){ 1239 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1240 return ((connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_DONE) 1241 && (connection->l2cap_state.extended_feature_mask & 0x08)); 1242 } 1243 #endif 1244 1245 static uint16_t l2cap_setup_options_request(l2cap_channel_t * channel, uint8_t * config_options){ 1246 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1247 // use ERTM options if supported 1248 if (l2cap_ertm_mode(channel)){ 1249 return l2cap_setup_options_ertm_request(channel, config_options); 1250 } 1251 #endif 1252 uint16_t mtu = channel->local_mtu; 1253 return l2cap_setup_options_mtu(config_options, mtu); 1254 } 1255 1256 static uint16_t l2cap_setup_options_response(l2cap_channel_t * channel, uint8_t * config_options){ 1257 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1258 // use ERTM options if supported 1259 if (l2cap_ertm_mode(channel)){ 1260 return l2cap_setup_options_ertm_response(channel, config_options); 1261 } 1262 #endif 1263 uint16_t mtu = btstack_min(channel->local_mtu, channel->remote_mtu); 1264 return l2cap_setup_options_mtu(config_options, mtu); 1265 } 1266 1267 static uint32_t l2cap_extended_features_mask(void){ 1268 // extended features request supported, features: fixed channels, unicast connectionless data reception 1269 uint32_t features = 0x280; 1270 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1271 features |= 0x0028; 1272 #endif 1273 return features; 1274 } 1275 #endif 1276 1277 // MARK: L2CAP_RUN 1278 // process outstanding signaling tasks 1279 static void l2cap_run(void){ 1280 1281 // log_info("l2cap_run: entered"); 1282 1283 // check pending signaling responses 1284 while (signaling_responses_pending){ 1285 1286 hci_con_handle_t handle = signaling_responses[0].handle; 1287 1288 if (!hci_can_send_acl_packet_now(handle)) break; 1289 1290 uint8_t sig_id = signaling_responses[0].sig_id; 1291 uint8_t response_code = signaling_responses[0].code; 1292 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 1293 #ifdef ENABLE_CLASSIC 1294 uint16_t info_type = signaling_responses[0].data; // INFORMATION_REQUEST 1295 uint16_t source_cid = signaling_responses[0].cid; // CONNECTION_REQUEST 1296 #endif 1297 1298 // remove first item before sending (to avoid sending response mutliple times) 1299 signaling_responses_pending--; 1300 int i; 1301 for (i=0; i < signaling_responses_pending; i++){ 1302 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 1303 } 1304 1305 switch (response_code){ 1306 #ifdef ENABLE_CLASSIC 1307 case CONNECTION_REQUEST: 1308 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, source_cid, 0, result, 0); 1309 // also disconnect if result is 0x0003 - security blocked 1310 if (result == 0x0003){ 1311 hci_disconnect_security_block(handle); 1312 } 1313 break; 1314 case ECHO_REQUEST: 1315 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 1316 break; 1317 case INFORMATION_REQUEST: 1318 switch (info_type){ 1319 case L2CAP_INFO_TYPE_CONNECTIONLESS_MTU: { 1320 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 1321 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 0, sizeof(connectionless_mtu), &connectionless_mtu); 1322 } 1323 break; 1324 case L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED: { 1325 uint32_t features = l2cap_extended_features_mask(); 1326 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 0, sizeof(features), &features); 1327 } 1328 break; 1329 case L2CAP_INFO_TYPE_FIXED_CHANNELS_SUPPORTED: { 1330 uint8_t map[8]; 1331 memset(map, 0, 8); 1332 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 1333 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 0, sizeof(map), &map); 1334 } 1335 break; 1336 default: 1337 // all other types are not supported 1338 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 1, 0, NULL); 1339 break; 1340 } 1341 break; 1342 case COMMAND_REJECT: 1343 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 1344 break; 1345 #endif 1346 #ifdef ENABLE_BLE 1347 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1348 l2cap_send_le_signaling_packet(handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, sig_id, 0, 0, 0, 0, result); 1349 break; 1350 case COMMAND_REJECT_LE: 1351 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 1352 break; 1353 #endif 1354 default: 1355 // should not happen 1356 break; 1357 } 1358 } 1359 1360 #if defined(ENABLE_CLASSIC) || defined(ENABLE_BLE) 1361 btstack_linked_list_iterator_t it; 1362 #endif 1363 1364 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1365 // send l2cap information request if neccessary 1366 hci_connections_get_iterator(&it); 1367 while(btstack_linked_list_iterator_has_next(&it)){ 1368 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1369 if (connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST){ 1370 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W4_EXTENDED_FEATURE_RESPONSE; 1371 // send information request for extended features 1372 uint8_t sig_id = l2cap_next_sig_id(); 1373 uint8_t info_type = L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED; 1374 l2cap_send_signaling_packet(connection->con_handle, INFORMATION_REQUEST, sig_id, info_type); 1375 return; 1376 } 1377 } 1378 #endif 1379 1380 #ifdef ENABLE_CLASSIC 1381 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1382 uint8_t config_options[18]; 1383 #else 1384 uint8_t config_options[10]; 1385 #endif 1386 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1387 while (btstack_linked_list_iterator_has_next(&it)){ 1388 1389 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1390 1391 if (channel->channel_type != L2CAP_CHANNEL_TYPE_CLASSIC) continue; 1392 1393 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 1394 switch (channel->state){ 1395 1396 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1397 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 1398 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1399 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 1400 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 1401 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 1402 } 1403 break; 1404 1405 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1406 if (!hci_can_send_command_packet_now()) break; 1407 // send connection request - set state first 1408 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 1409 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 1410 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 1411 break; 1412 1413 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 1414 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1415 channel->state = L2CAP_STATE_INVALID; 1416 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 1417 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 1418 l2cap_stop_rtx(channel); 1419 btstack_linked_list_iterator_remove(&it); 1420 btstack_memory_l2cap_channel_free(channel); 1421 break; 1422 1423 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 1424 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1425 channel->state = L2CAP_STATE_CONFIG; 1426 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1427 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 1428 break; 1429 1430 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 1431 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1432 // success, start l2cap handshake 1433 channel->local_sig_id = l2cap_next_sig_id(); 1434 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 1435 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 1436 l2cap_start_rtx(channel); 1437 break; 1438 1439 case L2CAP_STATE_CONFIG: 1440 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1441 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 1442 uint16_t flags = 0; 1443 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1444 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 1445 flags = 1; 1446 } else { 1447 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 1448 } 1449 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 1450 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 1451 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 1452 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1453 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED){ 1454 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 1455 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 1456 uint16_t options_size = l2cap_setup_options_response(channel, config_options); 1457 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); 1458 #endif 1459 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 1460 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1461 uint16_t options_size = l2cap_setup_options_response(channel, config_options); 1462 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); 1463 } else { 1464 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_SUCCESS, 0, NULL); 1465 } 1466 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1467 } 1468 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 1469 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1470 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 1471 channel->local_sig_id = l2cap_next_sig_id(); 1472 uint16_t options_size = l2cap_setup_options_request(channel, config_options); 1473 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, options_size, &config_options); 1474 l2cap_start_rtx(channel); 1475 } 1476 if (l2cap_channel_ready_for_open(channel)){ 1477 channel->state = L2CAP_STATE_OPEN; 1478 l2cap_emit_channel_opened(channel, 0); // success 1479 } 1480 break; 1481 1482 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 1483 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1484 channel->state = L2CAP_STATE_INVALID; 1485 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 1486 // 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 :) 1487 l2cap_finialize_channel_close(channel); // -- remove from list 1488 break; 1489 1490 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1491 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1492 channel->local_sig_id = l2cap_next_sig_id(); 1493 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 1494 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 1495 break; 1496 default: 1497 break; 1498 } 1499 1500 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1501 // send s-frame to acknowledge received packets 1502 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1503 1504 if (channel->tx_send_index != channel->tx_write_index){ 1505 // check remote tx window 1506 log_info("unacknowledged_packets %u, remote tx window size %u", channel->unacked_frames, channel->remote_tx_window_size); 1507 if (channel->unacked_frames < channel->remote_tx_window_size){ 1508 channel->unacked_frames++; 1509 int index = channel->tx_send_index; 1510 channel->tx_send_index++; 1511 if (channel->tx_send_index >= channel->num_tx_buffers){ 1512 channel->tx_send_index = 0; 1513 } 1514 l2cap_ertm_send_information_frame(channel, index, 0); // final = 0 1515 continue; 1516 } 1517 } 1518 1519 if (channel->send_supervisor_frame_receiver_ready){ 1520 channel->send_supervisor_frame_receiver_ready = 0; 1521 log_info("Send S-Frame: RR %u, final %u", channel->req_seq, channel->set_final_bit_after_packet_with_poll_bit_set); 1522 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); 1523 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1524 l2cap_ertm_send_supervisor_frame(channel, control); 1525 continue; 1526 } 1527 if (channel->send_supervisor_frame_receiver_ready_poll){ 1528 channel->send_supervisor_frame_receiver_ready_poll = 0; 1529 log_info("Send S-Frame: RR %u with poll=1 ", channel->req_seq); 1530 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY, 1, 0, channel->req_seq); 1531 l2cap_ertm_send_supervisor_frame(channel, control); 1532 continue; 1533 } 1534 if (channel->send_supervisor_frame_receiver_not_ready){ 1535 channel->send_supervisor_frame_receiver_not_ready = 0; 1536 log_info("Send S-Frame: RNR %u", channel->req_seq); 1537 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY, 0, 0, channel->req_seq); 1538 l2cap_ertm_send_supervisor_frame(channel, control); 1539 continue; 1540 } 1541 if (channel->send_supervisor_frame_reject){ 1542 channel->send_supervisor_frame_reject = 0; 1543 log_info("Send S-Frame: REJ %u", channel->req_seq); 1544 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT, 0, 0, channel->req_seq); 1545 l2cap_ertm_send_supervisor_frame(channel, control); 1546 continue; 1547 } 1548 if (channel->send_supervisor_frame_selective_reject){ 1549 channel->send_supervisor_frame_selective_reject = 0; 1550 log_info("Send S-Frame: SREJ %u", channel->expected_tx_seq); 1551 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); 1552 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1553 l2cap_ertm_send_supervisor_frame(channel, control); 1554 continue; 1555 } 1556 1557 if (channel->srej_active){ 1558 int i; 1559 for (i=0;i<channel->num_tx_buffers;i++){ 1560 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[i]; 1561 if (tx_state->retransmission_requested) { 1562 tx_state->retransmission_requested = 0; 1563 uint8_t final = channel->set_final_bit_after_packet_with_poll_bit_set; 1564 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1565 l2cap_ertm_send_information_frame(channel, i, final); 1566 break; 1567 } 1568 } 1569 if (i == channel->num_tx_buffers){ 1570 // no retransmission request found 1571 channel->srej_active = 0; 1572 } else { 1573 // packet was sent 1574 continue; 1575 } 1576 } 1577 #endif 1578 1579 } 1580 #endif 1581 1582 #ifdef ENABLE_LE_DATA_CHANNELS 1583 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1584 while (btstack_linked_list_iterator_has_next(&it)){ 1585 uint8_t * acl_buffer; 1586 uint8_t * l2cap_payload; 1587 uint16_t pos; 1588 uint16_t payload_size; 1589 uint16_t mps; 1590 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1591 1592 if (channel->channel_type != L2CAP_CHANNEL_TYPE_LE_DATA_CHANNEL) continue; 1593 1594 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 1595 switch (channel->state){ 1596 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 1597 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1598 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 1599 // le psm, source cid, mtu, mps, initial credits 1600 channel->local_sig_id = l2cap_next_sig_id(); 1601 channel->credits_incoming = channel->new_credits_incoming; 1602 channel->new_credits_incoming = 0; 1603 mps = btstack_min(l2cap_max_le_mtu(), channel->local_mtu); 1604 l2cap_send_le_signaling_packet( channel->con_handle, LE_CREDIT_BASED_CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid, channel->local_mtu, mps, channel->credits_incoming); 1605 break; 1606 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 1607 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1608 // TODO: support larger MPS 1609 channel->state = L2CAP_STATE_OPEN; 1610 channel->credits_incoming = channel->new_credits_incoming; 1611 channel->new_credits_incoming = 0; 1612 mps = btstack_min(l2cap_max_le_mtu(), channel->local_mtu); 1613 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->local_mtu, mps, channel->credits_incoming, 0); 1614 // notify client 1615 l2cap_emit_le_channel_opened(channel, 0); 1616 break; 1617 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 1618 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1619 channel->state = L2CAP_STATE_INVALID; 1620 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); 1621 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 1622 l2cap_stop_rtx(channel); 1623 btstack_linked_list_iterator_remove(&it); 1624 btstack_memory_l2cap_channel_free(channel); 1625 break; 1626 case L2CAP_STATE_OPEN: 1627 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1628 1629 // send credits 1630 if (channel->new_credits_incoming){ 1631 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 1632 channel->local_sig_id = l2cap_next_sig_id(); 1633 uint16_t new_credits = channel->new_credits_incoming; 1634 channel->new_credits_incoming = 0; 1635 channel->credits_incoming += new_credits; 1636 l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); 1637 break; 1638 } 1639 1640 // send data 1641 if (!channel->send_sdu_buffer) break; 1642 if (!channel->credits_outgoing) break; 1643 1644 // send part of SDU 1645 hci_reserve_packet_buffer(); 1646 acl_buffer = hci_get_outgoing_packet_buffer(); 1647 l2cap_payload = acl_buffer + 8; 1648 pos = 0; 1649 if (!channel->send_sdu_pos){ 1650 // store SDU len 1651 channel->send_sdu_pos += 2; 1652 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 1653 pos += 2; 1654 } 1655 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 1656 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); 1657 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 1658 pos += payload_size; 1659 channel->send_sdu_pos += payload_size; 1660 l2cap_setup_header(acl_buffer, channel->con_handle, 0, channel->remote_cid, pos); 1661 // done 1662 1663 channel->credits_outgoing--; 1664 1665 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 1666 channel->send_sdu_buffer = NULL; 1667 // send done event 1668 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_PACKET_SENT); 1669 // inform about can send now 1670 l2cap_le_notify_channel_can_send(channel); 1671 } 1672 hci_send_acl_packet_buffer(8 + pos); 1673 break; 1674 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1675 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1676 channel->local_sig_id = l2cap_next_sig_id(); 1677 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 1678 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 1679 break; 1680 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 1681 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1682 channel->state = L2CAP_STATE_INVALID; 1683 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 1684 l2cap_le_finialize_channel_close(channel); // -- remove from list 1685 break; 1686 default: 1687 break; 1688 } 1689 } 1690 #endif 1691 1692 #ifdef ENABLE_BLE 1693 // send l2cap con paramter update if necessary 1694 hci_connections_get_iterator(&it); 1695 while(btstack_linked_list_iterator_has_next(&it)){ 1696 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1697 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 1698 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 1699 switch (connection->le_con_parameter_update_state){ 1700 case CON_PARAMETER_UPDATE_SEND_REQUEST: 1701 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 1702 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 1703 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 1704 break; 1705 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 1706 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 1707 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 1708 break; 1709 case CON_PARAMETER_UPDATE_DENY: 1710 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 1711 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 1712 break; 1713 default: 1714 break; 1715 } 1716 } 1717 #endif 1718 1719 // log_info("l2cap_run: exit"); 1720 } 1721 1722 #ifdef ENABLE_CLASSIC 1723 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 1724 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 1725 log_info("l2cap_handle_connection_complete expected state"); 1726 // success, start l2cap handshake 1727 channel->con_handle = con_handle; 1728 // check remote SSP feature first 1729 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 1730 } 1731 } 1732 1733 static void l2cap_ready_to_connect(l2cap_channel_t * channel){ 1734 1735 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1736 // assumption: outgoing connection 1737 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1738 if (connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_IDLE){ 1739 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 1740 channel->state = L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES; 1741 return; 1742 } 1743 #endif 1744 1745 // fine, go ahead 1746 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1747 } 1748 1749 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 1750 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 1751 1752 // we have been waiting for remote supported features, if both support SSP, 1753 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)); 1754 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 1755 // request security level 2 1756 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 1757 channel->required_security_level = LEVEL_2; 1758 gap_request_security_level(channel->con_handle, LEVEL_2); 1759 return; 1760 } 1761 1762 l2cap_ready_to_connect(channel); 1763 } 1764 #endif 1765 1766 #ifdef L2CAP_USES_CHANNELS 1767 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, l2cap_channel_type_t channel_type, bd_addr_t address, bd_addr_type_t address_type, 1768 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 1769 1770 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 1771 if (!channel) { 1772 return NULL; 1773 } 1774 1775 // Init memory (make valgrind happy) 1776 memset(channel, 0, sizeof(l2cap_channel_t)); 1777 1778 // fill in 1779 channel->packet_handler = packet_handler; 1780 channel->channel_type = channel_type; 1781 bd_addr_copy(channel->address, address); 1782 channel->address_type = address_type; 1783 channel->psm = psm; 1784 channel->local_mtu = local_mtu; 1785 channel->remote_mtu = L2CAP_DEFAULT_MTU; 1786 channel->required_security_level = security_level; 1787 1788 // 1789 channel->local_cid = l2cap_next_local_cid(); 1790 channel->con_handle = 0; 1791 1792 // set initial state 1793 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 1794 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 1795 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 1796 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 1797 1798 return channel; 1799 } 1800 #endif 1801 1802 #ifdef ENABLE_CLASSIC 1803 1804 /** 1805 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 1806 * @param packet_handler 1807 * @param address 1808 * @param psm 1809 * @param mtu 1810 * @param local_cid 1811 */ 1812 1813 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){ 1814 // limit MTU to the size of our outtgoing HCI buffer 1815 uint16_t local_mtu = btstack_min(mtu, l2cap_max_mtu()); 1816 1817 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u -> local mtu %u", bd_addr_to_str(address), psm, mtu, local_mtu); 1818 1819 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, L2CAP_CHANNEL_TYPE_CLASSIC, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 1820 if (!channel) { 1821 return BTSTACK_MEMORY_ALLOC_FAILED; 1822 } 1823 1824 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1825 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1826 #endif 1827 1828 // add to connections list 1829 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1830 1831 // store local_cid 1832 if (out_local_cid){ 1833 *out_local_cid = channel->local_cid; 1834 } 1835 1836 // check if hci connection is already usable 1837 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 1838 if (conn){ 1839 log_info("l2cap_create_channel, hci connection already exists"); 1840 l2cap_handle_connection_complete(conn->con_handle, channel); 1841 // check if remote supported fearures are already received 1842 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 1843 l2cap_handle_remote_supported_features_received(channel); 1844 } 1845 } 1846 1847 l2cap_run(); 1848 1849 return 0; 1850 } 1851 1852 void 1853 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 1854 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 1855 // find channel for local_cid 1856 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1857 if (channel) { 1858 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1859 } 1860 // process 1861 l2cap_run(); 1862 } 1863 1864 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 1865 // mark all channels before emitting open events as these could trigger new connetion requests to the same device 1866 btstack_linked_list_iterator_t it; 1867 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1868 while (btstack_linked_list_iterator_has_next(&it)){ 1869 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1870 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 1871 if (bd_addr_cmp( channel->address, address) != 0) continue; 1872 // channel for this address found 1873 switch (channel->state){ 1874 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1875 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1876 channel->state = L2CAP_STATE_EMIT_OPEN_FAILED_AND_DISCARD; 1877 break; 1878 default: 1879 break; 1880 } 1881 } 1882 // emit and free marked entries. restart loop to deal with list changes 1883 int done = 0; 1884 while (!done) { 1885 done = 1; 1886 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1887 while (btstack_linked_list_iterator_has_next(&it)){ 1888 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1889 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 1890 if (channel->state == L2CAP_STATE_EMIT_OPEN_FAILED_AND_DISCARD){ 1891 done = 0; 1892 // failure, forward error code 1893 l2cap_emit_channel_opened(channel, status); 1894 // discard channel 1895 l2cap_stop_rtx(channel); 1896 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1897 btstack_memory_l2cap_channel_free(channel); 1898 break; 1899 } 1900 } 1901 } 1902 1903 } 1904 1905 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1906 btstack_linked_list_iterator_t it; 1907 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1908 while (btstack_linked_list_iterator_has_next(&it)){ 1909 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1910 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 1911 if ( ! bd_addr_cmp( channel->address, address) ){ 1912 l2cap_handle_connection_complete(handle, channel); 1913 } 1914 } 1915 // process 1916 l2cap_run(); 1917 } 1918 #endif 1919 1920 static void l2cap_notify_channel_can_send(void){ 1921 int done = 0; 1922 while (!done){ 1923 done = 1; 1924 btstack_linked_list_iterator_t it; 1925 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1926 while (btstack_linked_list_iterator_has_next(&it)){ 1927 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1928 if (!channel->waiting_for_can_send_now) continue; 1929 int can_send = 0; 1930 if (l2cap_is_le_channel_type(channel->channel_type)){ 1931 #ifdef ENABLE_BLE 1932 can_send = hci_can_send_acl_le_packet_now(); 1933 #endif 1934 } else { 1935 #ifdef ENABLE_CLASSIC 1936 can_send = hci_can_send_acl_classic_packet_now(); 1937 #endif 1938 } 1939 if (!can_send) continue; 1940 // requeue for fairness 1941 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1942 btstack_linked_list_add_tail(&l2cap_channels, (btstack_linked_item_t *) channel); 1943 // emit can send 1944 channel->waiting_for_can_send_now = 0; 1945 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1946 // exit inner loop as we just broke the iterator, but try again 1947 done = 0; 1948 break; 1949 } 1950 } 1951 } 1952 1953 #ifdef L2CAP_USES_CHANNELS 1954 1955 static int l2cap_send_open_failed_on_hci_disconnect(l2cap_channel_t * channel){ 1956 // open cannot fail for for incoming connections 1957 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING) return 0; 1958 1959 // check state 1960 switch (channel->state){ 1961 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1962 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1963 case L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES: 1964 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1965 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 1966 case L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES: 1967 case L2CAP_STATE_WAIT_CONNECT_RSP: 1968 case L2CAP_STATE_CONFIG: 1969 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 1970 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 1971 case L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE: 1972 case L2CAP_STATE_EMIT_OPEN_FAILED_AND_DISCARD: 1973 return 1; 1974 1975 case L2CAP_STATE_OPEN: 1976 case L2CAP_STATE_CLOSED: 1977 case L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES: 1978 case L2CAP_STATE_WAIT_DISCONNECT: 1979 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_INSUFFICIENT_SECURITY: 1980 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 1981 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 1982 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1983 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 1984 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 1985 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 1986 case L2CAP_STATE_INVALID: 1987 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1988 return 0; 1989 // no default here, to get a warning about new states 1990 } 1991 // still, the compiler insists on a return value 1992 return 0; 1993 } 1994 #endif 1995 1996 #ifdef ENABLE_CLASSIC 1997 static void l2cap_handle_hci_disconnect_event(l2cap_channel_t * channel){ 1998 if (l2cap_send_open_failed_on_hci_disconnect(channel)){ 1999 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_BASEBAND_DISCONNECT); 2000 } else { 2001 l2cap_emit_channel_closed(channel); 2002 } 2003 btstack_memory_l2cap_channel_free(channel); 2004 } 2005 #endif 2006 2007 #ifdef ENABLE_LE_DATA_CHANNELS 2008 static void l2cap_handle_hci_le_disconnect_event(l2cap_channel_t * channel){ 2009 if (l2cap_send_open_failed_on_hci_disconnect(channel)){ 2010 l2cap_emit_le_channel_opened(channel, L2CAP_CONNECTION_BASEBAND_DISCONNECT); 2011 } else { 2012 l2cap_emit_le_channel_closed(channel); 2013 } 2014 btstack_memory_l2cap_channel_free(channel); 2015 } 2016 #endif 2017 2018 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 2019 2020 UNUSED(packet_type); // ok: registered with hci_event_callback_registration 2021 UNUSED(cid); // ok: there is no channel 2022 UNUSED(size); // ok: fixed format events read from HCI buffer 2023 2024 #ifdef ENABLE_CLASSIC 2025 bd_addr_t address; 2026 int hci_con_used; 2027 #endif 2028 #ifdef L2CAP_USES_CHANNELS 2029 hci_con_handle_t handle; 2030 btstack_linked_list_iterator_t it; 2031 #endif 2032 2033 switch(hci_event_packet_get_type(packet)){ 2034 2035 // Notify channel packet handler if they can send now 2036 case HCI_EVENT_TRANSPORT_PACKET_SENT: 2037 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 2038 l2cap_run(); // try sending signaling packets first 2039 l2cap_notify_channel_can_send(); 2040 break; 2041 2042 case HCI_EVENT_COMMAND_STATUS: 2043 l2cap_run(); // try sending signaling packets first 2044 break; 2045 2046 #ifdef ENABLE_CLASSIC 2047 // handle connection complete events 2048 case HCI_EVENT_CONNECTION_COMPLETE: 2049 reverse_bd_addr(&packet[5], address); 2050 if (packet[2] == 0){ 2051 handle = little_endian_read_16(packet, 3); 2052 l2cap_handle_connection_success_for_addr(address, handle); 2053 } else { 2054 l2cap_handle_connection_failed_for_addr(address, packet[2]); 2055 } 2056 break; 2057 2058 // handle successful create connection cancel command 2059 case HCI_EVENT_COMMAND_COMPLETE: 2060 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 2061 if (packet[5] == 0){ 2062 reverse_bd_addr(&packet[6], address); 2063 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 2064 l2cap_handle_connection_failed_for_addr(address, 0x16); 2065 } 2066 } 2067 l2cap_run(); // try sending signaling packets first 2068 break; 2069 #endif 2070 2071 #ifdef L2CAP_USES_CHANNELS 2072 // handle disconnection complete events 2073 case HCI_EVENT_DISCONNECTION_COMPLETE: 2074 handle = little_endian_read_16(packet, 3); 2075 // send l2cap open failed or closed events for all channels on this handle and free them 2076 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2077 while (btstack_linked_list_iterator_has_next(&it)){ 2078 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2079 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 2080 if (channel->con_handle != handle) continue; 2081 btstack_linked_list_iterator_remove(&it); 2082 switch(channel->channel_type){ 2083 #ifdef ENABLE_CLASSIC 2084 case L2CAP_CHANNEL_TYPE_CLASSIC: 2085 l2cap_stop_rtx(channel); 2086 l2cap_handle_hci_disconnect_event(channel); 2087 break; 2088 #endif 2089 #ifdef ENABLE_LE_DATA_CHANNELS 2090 case L2CAP_CHANNEL_TYPE_LE_DATA_CHANNEL: 2091 l2cap_handle_hci_le_disconnect_event(channel); 2092 break; 2093 #endif 2094 default: 2095 break; 2096 } 2097 } 2098 #endif 2099 2100 // HCI Connection Timeouts 2101 #ifdef ENABLE_CLASSIC 2102 case L2CAP_EVENT_TIMEOUT_CHECK: 2103 handle = little_endian_read_16(packet, 2); 2104 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 2105 if (hci_authentication_active_for_handle(handle)) break; 2106 hci_con_used = 0; 2107 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2108 while (btstack_linked_list_iterator_has_next(&it)){ 2109 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2110 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 2111 if (channel->con_handle != handle) continue; 2112 hci_con_used = 1; 2113 break; 2114 } 2115 if (hci_con_used) break; 2116 if (!hci_can_send_command_packet_now()) break; 2117 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 2118 break; 2119 2120 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 2121 handle = little_endian_read_16(packet, 3); 2122 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2123 while (btstack_linked_list_iterator_has_next(&it)){ 2124 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2125 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 2126 if (channel->con_handle != handle) continue; 2127 l2cap_handle_remote_supported_features_received(channel); 2128 break; 2129 } 2130 break; 2131 2132 case GAP_EVENT_SECURITY_LEVEL: 2133 handle = little_endian_read_16(packet, 2); 2134 log_info("l2cap - security level update"); 2135 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2136 while (btstack_linked_list_iterator_has_next(&it)){ 2137 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2138 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 2139 if (channel->con_handle != handle) continue; 2140 2141 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 2142 gap_security_level_t required_level = channel->required_security_level; 2143 2144 log_info("channel state %u: actual %u >= required %u?", channel->state, actual_level, required_level); 2145 2146 switch (channel->state){ 2147 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 2148 if (actual_level >= required_level){ 2149 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2150 // we need to know if ERTM is supported before sending a config response 2151 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 2152 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 2153 channel->state = L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES; 2154 #else 2155 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2156 l2cap_emit_incoming_connection(channel); 2157 #endif 2158 } else { 2159 channel->reason = 0x0003; // security block 2160 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 2161 } 2162 break; 2163 2164 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 2165 if (actual_level >= required_level){ 2166 l2cap_ready_to_connect(channel); 2167 } else { 2168 // disconnnect, authentication not good enough 2169 hci_disconnect_security_block(handle); 2170 } 2171 break; 2172 2173 default: 2174 break; 2175 } 2176 } 2177 break; 2178 #endif 2179 2180 default: 2181 break; 2182 } 2183 2184 l2cap_run(); 2185 } 2186 2187 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t cid, uint16_t data){ 2188 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 2189 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 2190 signaling_responses[signaling_responses_pending].handle = handle; 2191 signaling_responses[signaling_responses_pending].code = code; 2192 signaling_responses[signaling_responses_pending].sig_id = sig_id; 2193 signaling_responses[signaling_responses_pending].cid = cid; 2194 signaling_responses[signaling_responses_pending].data = data; 2195 signaling_responses_pending++; 2196 l2cap_run(); 2197 } 2198 } 2199 2200 #ifdef ENABLE_CLASSIC 2201 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 2202 channel->remote_sig_id = identifier; 2203 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 2204 l2cap_run(); 2205 } 2206 2207 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 2208 2209 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 2210 l2cap_service_t *service = l2cap_get_service(psm); 2211 if (!service) { 2212 // 0x0002 PSM not supported 2213 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 2214 return; 2215 } 2216 2217 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 2218 if (!hci_connection) { 2219 // 2220 log_error("no hci_connection for handle %u", handle); 2221 return; 2222 } 2223 2224 // alloc structure 2225 // log_info("l2cap_handle_connection_request register channel"); 2226 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, L2CAP_CHANNEL_TYPE_CLASSIC, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 2227 psm, service->mtu, service->required_security_level); 2228 if (!channel){ 2229 // 0x0004 No resources available 2230 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 2231 return; 2232 } 2233 2234 channel->con_handle = handle; 2235 channel->remote_cid = source_cid; 2236 channel->remote_sig_id = sig_id; 2237 2238 // limit local mtu to max acl packet length - l2cap header 2239 if (channel->local_mtu > l2cap_max_mtu()) { 2240 channel->local_mtu = l2cap_max_mtu(); 2241 } 2242 2243 // set initial state 2244 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 2245 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND | L2CAP_CHANNEL_STATE_VAR_INCOMING); 2246 2247 // add to connections list 2248 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 2249 2250 // assert security requirements 2251 gap_request_security_level(handle, channel->required_security_level); 2252 } 2253 2254 void l2cap_accept_connection(uint16_t local_cid){ 2255 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 2256 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 2257 if (!channel) { 2258 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 2259 return; 2260 } 2261 2262 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2263 // configure L2CAP Basic mode 2264 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2265 #endif 2266 2267 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 2268 2269 // process 2270 l2cap_run(); 2271 } 2272 2273 void l2cap_decline_connection(uint16_t local_cid){ 2274 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 2275 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 2276 if (!channel) { 2277 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 2278 return; 2279 } 2280 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 2281 channel->reason = 0x04; // no resources available 2282 l2cap_run(); 2283 } 2284 2285 // @pre command len is valid, see check in l2cap_signaling_handler_channel 2286 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 2287 2288 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2289 uint8_t use_fcs = 1; 2290 #endif 2291 2292 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2293 2294 uint16_t flags = little_endian_read_16(command, 6); 2295 if (flags & 1) { 2296 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 2297 } 2298 2299 // accept the other's configuration options 2300 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2301 uint16_t pos = 8; 2302 while (pos < end_pos){ 2303 uint8_t option_hint = command[pos] >> 7; 2304 uint8_t option_type = command[pos] & 0x7f; 2305 // log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 2306 pos++; 2307 uint8_t length = command[pos++]; 2308 // MTU { type(8): 1, len(8):2, MTU(16) } 2309 if (option_type == L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT && length == 2){ 2310 channel->remote_mtu = little_endian_read_16(command, pos); 2311 log_info("Remote MTU %u", channel->remote_mtu); 2312 if (channel->remote_mtu > l2cap_max_mtu()){ 2313 log_info("Remote MTU %u larger than outgoing buffer, only using MTU = %u", channel->remote_mtu, l2cap_max_mtu()); 2314 channel->remote_mtu = l2cap_max_mtu(); 2315 } 2316 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 2317 } 2318 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 2319 if (option_type == L2CAP_CONFIG_OPTION_TYPE_FLUSH_TIMEOUT && length == 2){ 2320 channel->flush_timeout = little_endian_read_16(command, pos); 2321 log_info("Flush timeout: %u ms", channel->flush_timeout); 2322 } 2323 2324 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2325 // Retransmission and Flow Control Option 2326 if (option_type == L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL && length == 9){ 2327 l2cap_channel_mode_t mode = (l2cap_channel_mode_t) command[pos]; 2328 switch(channel->mode){ 2329 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 2330 // Store remote config 2331 channel->remote_tx_window_size = command[pos+1]; 2332 channel->remote_max_transmit = command[pos+2]; 2333 channel->remote_retransmission_timeout_ms = little_endian_read_16(command, pos + 3); 2334 channel->remote_monitor_timeout_ms = little_endian_read_16(command, pos + 5); 2335 channel->remote_mps = little_endian_read_16(command, pos + 7); 2336 log_info("FC&C config: tx window: %u, max transmit %u, retrans timeout %u, monitor timeout %u, mps %u", 2337 channel->remote_tx_window_size, 2338 channel->remote_max_transmit, 2339 channel->remote_retransmission_timeout_ms, 2340 channel->remote_monitor_timeout_ms, 2341 channel->remote_mps); 2342 // If ERTM mandatory, but remote doens't offer ERTM -> disconnect 2343 if (channel->ertm_mandatory && mode != L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 2344 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2345 } else { 2346 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 2347 } 2348 break; 2349 case L2CAP_CHANNEL_MODE_BASIC: 2350 switch (mode){ 2351 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 2352 // remote asks for ERTM, but we want basic mode. disconnect if this happens a second time 2353 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED){ 2354 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2355 } 2356 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED); 2357 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 2358 break; 2359 default: // case L2CAP_CHANNEL_MODE_BASIC: 2360 // TODO store and evaluate configuration 2361 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 2362 break; 2363 } 2364 break; 2365 default: 2366 break; 2367 } 2368 } 2369 if (option_type == L2CAP_CONFIG_OPTION_TYPE_FRAME_CHECK_SEQUENCE && length == 1){ 2370 use_fcs = command[pos]; 2371 } 2372 #endif 2373 // check for unknown options 2374 if (option_hint == 0 && (option_type < L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT || option_type > L2CAP_CONFIG_OPTION_TYPE_EXTENDED_WINDOW_SIZE)){ 2375 log_info("l2cap cid %u, unknown options", channel->local_cid); 2376 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 2377 } 2378 pos += length; 2379 } 2380 2381 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2382 // "FCS" has precedence over "No FCS" 2383 uint8_t update = channel->fcs_option || use_fcs; 2384 log_info("local fcs: %u, remote fcs: %u -> %u", channel->fcs_option, use_fcs, update); 2385 channel->fcs_option = update; 2386 #endif 2387 } 2388 2389 // @pre command len is valid, see check in l2cap_signaling_handler_channel 2390 static void l2cap_signaling_handle_configure_response(l2cap_channel_t *channel, uint8_t result, uint8_t *command){ 2391 log_info("l2cap_signaling_handle_configure_response"); 2392 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2393 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2394 uint16_t pos = 10; 2395 while (pos < end_pos){ 2396 uint8_t option_hint = command[pos] >> 7; 2397 uint8_t option_type = command[pos] & 0x7f; 2398 // log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 2399 pos++; 2400 uint8_t length = command[pos++]; 2401 2402 // Retransmission and Flow Control Option 2403 if (option_type == L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL && length == 9){ 2404 switch (channel->mode){ 2405 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 2406 if (channel->ertm_mandatory){ 2407 // ?? 2408 } else { 2409 // On 'Reject - Unacceptable Parameters' to our optional ERTM request, fall back to BASIC mode 2410 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 2411 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2412 } 2413 } 2414 break; 2415 case L2CAP_CHANNEL_MODE_BASIC: 2416 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 2417 // On 'Reject - Unacceptable Parameters' to our Basic mode request, disconnect 2418 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2419 } 2420 break; 2421 default: 2422 break; 2423 } 2424 } 2425 2426 // check for unknown options 2427 if (option_hint == 0 && (option_type < L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT || option_type > L2CAP_CONFIG_OPTION_TYPE_EXTENDED_WINDOW_SIZE)){ 2428 log_info("l2cap cid %u, unknown options", channel->local_cid); 2429 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 2430 } 2431 2432 pos += length; 2433 } 2434 #else 2435 UNUSED(channel); // ok: no code 2436 UNUSED(result); // ok: no code 2437 UNUSED(command); // ok: no code 2438 #endif 2439 } 2440 2441 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 2442 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 2443 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 2444 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 2445 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 2446 if (channel->state == L2CAP_STATE_OPEN) return 0; 2447 return 1; 2448 } 2449 2450 2451 // @pre command len is valid, see check in l2cap_signaling_handler_dispatch 2452 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 2453 2454 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2455 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2456 uint16_t cmd_len = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2457 uint16_t result = 0; 2458 2459 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 2460 2461 // handle DISCONNECT REQUESTS seperately 2462 if (code == DISCONNECTION_REQUEST){ 2463 switch (channel->state){ 2464 case L2CAP_STATE_CONFIG: 2465 case L2CAP_STATE_OPEN: 2466 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 2467 case L2CAP_STATE_WAIT_DISCONNECT: 2468 l2cap_handle_disconnect_request(channel, identifier); 2469 break; 2470 2471 default: 2472 // ignore in other states 2473 break; 2474 } 2475 return; 2476 } 2477 2478 // @STATEMACHINE(l2cap) 2479 switch (channel->state) { 2480 2481 case L2CAP_STATE_WAIT_CONNECT_RSP: 2482 switch (code){ 2483 case CONNECTION_RESPONSE: 2484 if (cmd_len < 8){ 2485 // command imcomplete 2486 l2cap_register_signaling_response(channel->con_handle, COMMAND_REJECT, identifier, 0, L2CAP_REJ_CMD_UNKNOWN); 2487 break; 2488 } 2489 l2cap_stop_rtx(channel); 2490 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2491 switch (result) { 2492 case 0: 2493 // successful connection 2494 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2495 channel->state = L2CAP_STATE_CONFIG; 2496 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 2497 break; 2498 case 1: 2499 // connection pending. get some coffee, but start the ERTX 2500 l2cap_start_ertx(channel); 2501 break; 2502 default: 2503 // channel closed 2504 channel->state = L2CAP_STATE_CLOSED; 2505 // map l2cap connection response result to BTstack status enumeration 2506 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 2507 2508 // drop link key if security block 2509 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 2510 gap_drop_link_key_for_bd_addr(channel->address); 2511 } 2512 2513 // discard channel 2514 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2515 btstack_memory_l2cap_channel_free(channel); 2516 break; 2517 } 2518 break; 2519 2520 default: 2521 //@TODO: implement other signaling packets 2522 break; 2523 } 2524 break; 2525 2526 case L2CAP_STATE_CONFIG: 2527 switch (code) { 2528 case CONFIGURE_REQUEST: 2529 if (cmd_len < 4){ 2530 // command incomplete 2531 l2cap_register_signaling_response(channel->con_handle, COMMAND_REJECT, identifier, 0, L2CAP_REJ_CMD_UNKNOWN); 2532 break; 2533 } 2534 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 2535 l2cap_signaling_handle_configure_request(channel, command); 2536 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 2537 // only done if continuation not set 2538 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 2539 } 2540 break; 2541 case CONFIGURE_RESPONSE: 2542 if (cmd_len < 6){ 2543 // command incomplete 2544 l2cap_register_signaling_response(channel->con_handle, COMMAND_REJECT, identifier, 0, L2CAP_REJ_CMD_UNKNOWN); 2545 break; 2546 } 2547 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2548 l2cap_stop_rtx(channel); 2549 l2cap_signaling_handle_configure_response(channel, result, command); 2550 switch (result){ 2551 case 0: // success 2552 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 2553 break; 2554 case 4: // pending 2555 l2cap_start_ertx(channel); 2556 break; 2557 default: 2558 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2559 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION && channel->ertm_mandatory){ 2560 // remote does not offer ertm but it's required 2561 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2562 break; 2563 } 2564 #endif 2565 // retry on negative result 2566 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 2567 break; 2568 } 2569 break; 2570 default: 2571 break; 2572 } 2573 if (l2cap_channel_ready_for_open(channel)){ 2574 // for open: 2575 channel->state = L2CAP_STATE_OPEN; 2576 l2cap_emit_channel_opened(channel, 0); 2577 } 2578 break; 2579 2580 case L2CAP_STATE_WAIT_DISCONNECT: 2581 switch (code) { 2582 case DISCONNECTION_RESPONSE: 2583 l2cap_finialize_channel_close(channel); 2584 break; 2585 default: 2586 //@TODO: implement other signaling packets 2587 break; 2588 } 2589 break; 2590 2591 case L2CAP_STATE_CLOSED: 2592 // @TODO handle incoming requests 2593 break; 2594 2595 case L2CAP_STATE_OPEN: 2596 //@TODO: implement other signaling packets, e.g. re-configure 2597 break; 2598 default: 2599 break; 2600 } 2601 // log_info("new state %u", channel->state); 2602 } 2603 2604 2605 // @pre command len is valid, see check in l2cap_acl_classic_handler 2606 static void l2cap_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command){ 2607 2608 btstack_linked_list_iterator_t it; 2609 2610 // get code, signalind identifier and command len 2611 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2612 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2613 uint16_t cmd_len = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2614 2615 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_RESPONSE 2616 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_RESPONSE){ 2617 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2618 return; 2619 } 2620 2621 // general commands without an assigned channel 2622 switch(code) { 2623 2624 case CONNECTION_REQUEST: 2625 if (cmd_len == 4){ 2626 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2627 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2628 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 2629 } else { 2630 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2631 } 2632 return; 2633 2634 case ECHO_REQUEST: 2635 l2cap_register_signaling_response(handle, code, sig_id, 0, 0); 2636 return; 2637 2638 case INFORMATION_REQUEST: 2639 if (cmd_len == 2) { 2640 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2641 l2cap_register_signaling_response(handle, code, sig_id, 0, info_type); 2642 } else { 2643 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2644 } 2645 return; 2646 2647 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2648 case INFORMATION_RESPONSE: { 2649 hci_connection_t * connection = hci_connection_for_handle(handle); 2650 if (!connection) return; 2651 if (cmd_len >= 4) { 2652 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2653 uint16_t result = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2654 if (result != 0) return; 2655 if (info_type != L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED) return; 2656 if (cmd_len >= 6) { 2657 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_DONE; 2658 connection->l2cap_state.extended_feature_mask = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2659 log_info("extended features mask 0x%02x", connection->l2cap_state.extended_feature_mask); 2660 // trigger connection request 2661 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2662 while (btstack_linked_list_iterator_has_next(&it)){ 2663 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2664 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 2665 if (channel->con_handle != handle) continue; 2666 // bail if ERTM was requested but is not supported 2667 if ((channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION) && ((connection->l2cap_state.extended_feature_mask & 0x08) == 0)){ 2668 if (channel->ertm_mandatory){ 2669 // channel closed 2670 channel->state = L2CAP_STATE_CLOSED; 2671 // map l2cap connection response result to BTstack status enumeration 2672 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_ERTM_NOT_SUPPORTED); 2673 // discard channel 2674 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2675 btstack_memory_l2cap_channel_free(channel); 2676 continue; 2677 } else { 2678 // fallback to Basic mode 2679 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2680 } 2681 } 2682 // start connecting 2683 if (channel->state == L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES){ 2684 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 2685 } 2686 // respond to connection request 2687 if (channel->state == L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES){ 2688 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2689 l2cap_emit_incoming_connection(channel); 2690 } 2691 } 2692 return; // cmd len valid 2693 } 2694 } 2695 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2696 return; 2697 } 2698 #endif 2699 2700 default: 2701 break; 2702 } 2703 2704 // Get potential destination CID 2705 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2706 2707 // Find channel for this sig_id and connection handle 2708 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2709 while (btstack_linked_list_iterator_has_next(&it)){ 2710 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2711 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 2712 if (channel->con_handle != handle) continue; 2713 if (code & 1) { 2714 // match odd commands (responses) by previous signaling identifier 2715 if (channel->local_sig_id == sig_id) { 2716 l2cap_signaling_handler_channel(channel, command); 2717 break; 2718 } 2719 } else { 2720 // match even commands (requests) by local channel id 2721 if (channel->local_cid == dest_cid) { 2722 l2cap_signaling_handler_channel(channel, command); 2723 break; 2724 } 2725 } 2726 } 2727 } 2728 #endif 2729 2730 #ifdef ENABLE_BLE 2731 2732 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 2733 uint8_t event[6]; 2734 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 2735 event[1] = 4; 2736 little_endian_store_16(event, 2, con_handle); 2737 little_endian_store_16(event, 4, result); 2738 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2739 if (!l2cap_event_packet_handler) return; 2740 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 2741 } 2742 2743 // @returns valid 2744 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 2745 hci_connection_t * connection; 2746 uint16_t result; 2747 uint8_t event[10]; 2748 2749 #ifdef ENABLE_LE_DATA_CHANNELS 2750 btstack_linked_list_iterator_t it; 2751 l2cap_channel_t * channel; 2752 uint16_t local_cid; 2753 uint16_t le_psm; 2754 uint16_t new_credits; 2755 uint16_t credits_before; 2756 l2cap_service_t * service; 2757 uint16_t source_cid; 2758 #endif 2759 2760 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2761 uint16_t len = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2762 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u, len %u", code, sig_id, len); 2763 2764 switch (code){ 2765 2766 case CONNECTION_PARAMETER_UPDATE_REQUEST: 2767 // check size 2768 if (len < 8) return 0; 2769 connection = hci_connection_for_handle(handle); 2770 if (connection){ 2771 if (connection->role != HCI_ROLE_MASTER){ 2772 // reject command without notifying upper layer when not in master role 2773 return 0; 2774 } 2775 le_connection_parameter_range_t existing_range; 2776 gap_get_connection_parameter_range(&existing_range); 2777 uint16_t le_conn_interval_min = little_endian_read_16(command,L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2778 uint16_t le_conn_interval_max = little_endian_read_16(command,L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2779 uint16_t le_conn_latency = little_endian_read_16(command,L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2780 uint16_t le_supervision_timeout = little_endian_read_16(command,L2CAP_SIGNALING_COMMAND_DATA_OFFSET+6); 2781 2782 int update_parameter = gap_connection_parameter_range_included(&existing_range, le_conn_interval_min, le_conn_interval_max, le_conn_latency, le_supervision_timeout); 2783 if (update_parameter){ 2784 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 2785 connection->le_conn_interval_min = le_conn_interval_min; 2786 connection->le_conn_interval_max = le_conn_interval_max; 2787 connection->le_conn_latency = le_conn_latency; 2788 connection->le_supervision_timeout = le_supervision_timeout; 2789 } else { 2790 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 2791 } 2792 connection->le_con_param_update_identifier = sig_id; 2793 } 2794 2795 if (!l2cap_event_packet_handler) break; 2796 2797 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 2798 event[1] = 8; 2799 memcpy(&event[2], &command[4], 8); 2800 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2801 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2802 break; 2803 2804 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 2805 // check size 2806 if (len < 2) return 0; 2807 result = little_endian_read_16(command, 4); 2808 l2cap_emit_connection_parameter_update_response(handle, result); 2809 break; 2810 2811 #ifdef ENABLE_LE_DATA_CHANNELS 2812 2813 case COMMAND_REJECT: 2814 // Find channel for this sig_id and connection handle 2815 channel = NULL; 2816 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2817 while (btstack_linked_list_iterator_has_next(&it)){ 2818 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2819 if (!l2cap_is_dynamic_channel_type(a_channel->channel_type)) continue; 2820 if (a_channel->con_handle != handle) continue; 2821 if (a_channel->local_sig_id != sig_id) continue; 2822 channel = a_channel; 2823 break; 2824 } 2825 if (!channel) break; 2826 2827 // if received while waiting for le connection response, assume legacy device 2828 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 2829 channel->state = L2CAP_STATE_CLOSED; 2830 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 2831 l2cap_emit_le_channel_opened(channel, 0x0002); 2832 2833 // discard channel 2834 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2835 btstack_memory_l2cap_channel_free(channel); 2836 break; 2837 } 2838 break; 2839 2840 case LE_CREDIT_BASED_CONNECTION_REQUEST: 2841 // check size 2842 if (len < 10) return 0; 2843 2844 // get hci connection, bail if not found (must not happen) 2845 connection = hci_connection_for_handle(handle); 2846 if (!connection) return 0; 2847 2848 // check if service registered 2849 le_psm = little_endian_read_16(command, 4); 2850 service = l2cap_le_get_service(le_psm); 2851 source_cid = little_endian_read_16(command, 6); 2852 2853 if (service){ 2854 if (source_cid < 0x40){ 2855 // 0x0009 Connection refused - Invalid Source CID 2856 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0009); 2857 return 1; 2858 } 2859 2860 // go through list of channels for this ACL connection and check if we get a match 2861 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2862 while (btstack_linked_list_iterator_has_next(&it)){ 2863 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2864 if (!l2cap_is_dynamic_channel_type(a_channel->channel_type)) continue; 2865 if (a_channel->con_handle != handle) continue; 2866 if (a_channel->remote_cid != source_cid) continue; 2867 // 0x000a Connection refused - Source CID already allocated 2868 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x000a); 2869 return 1; 2870 } 2871 2872 // security: check encryption 2873 if (service->required_security_level >= LEVEL_2){ 2874 if (gap_encryption_key_size(handle) == 0){ 2875 // 0x0008 Connection refused - insufficient encryption 2876 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0008); 2877 return 1; 2878 } 2879 // anything less than 16 byte key size is insufficient 2880 if (gap_encryption_key_size(handle) < 16){ 2881 // 0x0007 Connection refused – insufficient encryption key size 2882 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0007); 2883 return 1; 2884 } 2885 } 2886 2887 // security: check authencation 2888 if (service->required_security_level >= LEVEL_3){ 2889 if (!gap_authenticated(handle)){ 2890 // 0x0005 Connection refused – insufficient authentication 2891 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0005); 2892 return 1; 2893 } 2894 } 2895 2896 // security: check authorization 2897 if (service->required_security_level >= LEVEL_4){ 2898 if (gap_authorization_state(handle) != AUTHORIZATION_GRANTED){ 2899 // 0x0006 Connection refused – insufficient authorization 2900 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0006); 2901 return 1; 2902 } 2903 } 2904 2905 // allocate channel 2906 channel = l2cap_create_channel_entry(service->packet_handler, L2CAP_CHANNEL_TYPE_LE_DATA_CHANNEL, connection->address, 2907 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 2908 if (!channel){ 2909 // 0x0004 Connection refused – no resources available 2910 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 2911 return 1; 2912 } 2913 2914 channel->con_handle = handle; 2915 channel->remote_cid = source_cid; 2916 channel->remote_sig_id = sig_id; 2917 channel->remote_mtu = little_endian_read_16(command, 8); 2918 channel->remote_mps = little_endian_read_16(command, 10); 2919 channel->credits_outgoing = little_endian_read_16(command, 12); 2920 2921 // set initial state 2922 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2923 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 2924 2925 // add to connections list 2926 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 2927 2928 // post connection request event 2929 l2cap_emit_le_incoming_connection(channel); 2930 2931 } else { 2932 // Connection refused – LE_PSM not supported 2933 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 2934 } 2935 break; 2936 2937 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 2938 // check size 2939 if (len < 10) return 0; 2940 2941 // Find channel for this sig_id and connection handle 2942 channel = NULL; 2943 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2944 while (btstack_linked_list_iterator_has_next(&it)){ 2945 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2946 if (!l2cap_is_dynamic_channel_type(a_channel->channel_type)) continue; 2947 if (a_channel->con_handle != handle) continue; 2948 if (a_channel->local_sig_id != sig_id) continue; 2949 channel = a_channel; 2950 break; 2951 } 2952 if (!channel) break; 2953 2954 // cid + 0 2955 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 2956 if (result){ 2957 channel->state = L2CAP_STATE_CLOSED; 2958 // map l2cap connection response result to BTstack status enumeration 2959 l2cap_emit_le_channel_opened(channel, result); 2960 2961 // discard channel 2962 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2963 btstack_memory_l2cap_channel_free(channel); 2964 break; 2965 } 2966 2967 // success 2968 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2969 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2970 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 2971 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 2972 channel->state = L2CAP_STATE_OPEN; 2973 l2cap_emit_le_channel_opened(channel, result); 2974 break; 2975 2976 case LE_FLOW_CONTROL_CREDIT: 2977 // check size 2978 if (len < 4) return 0; 2979 2980 // find channel 2981 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2982 channel = l2cap_get_channel_for_local_cid(local_cid); 2983 if (!channel) { 2984 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2985 break; 2986 } 2987 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2988 credits_before = channel->credits_outgoing; 2989 channel->credits_outgoing += new_credits; 2990 // check for credit overrun 2991 if (credits_before > channel->credits_outgoing){ 2992 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 2993 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2994 break; 2995 } 2996 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 2997 break; 2998 2999 case DISCONNECTION_REQUEST: 3000 3001 // check size 3002 if (len < 4) return 0; 3003 3004 // find channel 3005 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 3006 channel = l2cap_get_channel_for_local_cid(local_cid); 3007 if (!channel) { 3008 log_error("l2cap: no channel for cid 0x%02x", local_cid); 3009 break; 3010 } 3011 channel->remote_sig_id = sig_id; 3012 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 3013 break; 3014 3015 #endif 3016 3017 case DISCONNECTION_RESPONSE: 3018 break; 3019 3020 default: 3021 // command unknown -> reject command 3022 return 0; 3023 } 3024 return 1; 3025 } 3026 #endif 3027 3028 static void l2cap_acl_classic_handler(hci_con_handle_t handle, uint8_t *packet, uint16_t size){ 3029 #ifdef ENABLE_CLASSIC 3030 l2cap_channel_t * l2cap_channel; 3031 l2cap_fixed_channel_t * l2cap_fixed_channel; 3032 3033 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 3034 switch (channel_id) { 3035 3036 case L2CAP_CID_SIGNALING: { 3037 uint16_t command_offset = 8; 3038 while (command_offset < size) { 3039 // assert signaling command is fully inside packet 3040 uint16_t data_len = little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 3041 uint32_t next_command_offset = ((uint32_t) command_offset) + L2CAP_SIGNALING_COMMAND_DATA_OFFSET + data_len; 3042 if (next_command_offset > size){ 3043 log_error("l2cap signaling command len invalid -> drop"); 3044 break; 3045 } 3046 // handle signaling command 3047 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 3048 // go to next command 3049 command_offset = (uint16_t) next_command_offset; 3050 } 3051 break; 3052 } 3053 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 3054 l2cap_fixed_channel = l2cap_fixed_channel_for_channel_id(L2CAP_CID_CONNECTIONLESS_CHANNEL); 3055 if (!l2cap_fixed_channel) break; 3056 if (!l2cap_fixed_channel->packet_handler) break; 3057 (*l2cap_fixed_channel->packet_handler)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 3058 break; 3059 3060 default: 3061 // Find channel for this channel_id and connection handle 3062 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 3063 if (l2cap_channel) { 3064 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 3065 if (l2cap_channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 3066 3067 int fcs_size = l2cap_channel->fcs_option ? 2 : 0; 3068 3069 // assert control + FCS fields are inside 3070 if (size < COMPLETE_L2CAP_HEADER+2+fcs_size) break; 3071 3072 if (l2cap_channel->fcs_option){ 3073 // verify FCS (required if one side requested it) 3074 uint16_t fcs_calculated = crc16_calc(&packet[4], size - (4+2)); 3075 uint16_t fcs_packet = little_endian_read_16(packet, size-2); 3076 if (fcs_calculated == fcs_packet){ 3077 log_info("Packet FCS 0x%04x verified", fcs_packet); 3078 } else { 3079 log_error("FCS mismatch! Packet 0x%04x, calculated 0x%04x", fcs_packet, fcs_calculated); 3080 // TODO: trigger retransmission or something like that 3081 break; 3082 } 3083 } 3084 3085 // switch on packet type 3086 uint16_t control = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 3087 uint8_t req_seq = (control >> 8) & 0x3f; 3088 int final = (control >> 7) & 0x01; 3089 if (control & 1){ 3090 // S-Frame 3091 int poll = (control >> 4) & 0x01; 3092 l2cap_supervisory_function_t s = (l2cap_supervisory_function_t) ((control >> 2) & 0x03); 3093 log_info("Control: 0x%04x => Supervisory function %u, ReqSeq %02u", control, (int) s, req_seq); 3094 l2cap_ertm_tx_packet_state_t * tx_state; 3095 switch (s){ 3096 case L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY: 3097 log_info("L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY"); 3098 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 3099 if (poll && final){ 3100 // S-frames shall not be transmitted with both the F-bit and the P-bit set to 1 at the same time. 3101 log_error("P=F=1 in S-Frame"); 3102 break; 3103 } 3104 if (poll){ 3105 // check if we did request selective retransmission before <==> we have stored SDU segments 3106 int i; 3107 int num_stored_out_of_order_packets = 0; 3108 for (i=0;i<l2cap_channel->num_rx_buffers;i++){ 3109 int index = l2cap_channel->rx_store_index + i; 3110 if (index >= l2cap_channel->num_rx_buffers){ 3111 index -= l2cap_channel->num_rx_buffers; 3112 } 3113 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 3114 if (!rx_state->valid) continue; 3115 num_stored_out_of_order_packets++; 3116 } 3117 if (num_stored_out_of_order_packets){ 3118 l2cap_channel->send_supervisor_frame_selective_reject = 1; 3119 } else { 3120 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 3121 } 3122 l2cap_channel->set_final_bit_after_packet_with_poll_bit_set = 1; 3123 } 3124 if (final){ 3125 // Stop-MonitorTimer 3126 l2cap_ertm_stop_monitor_timer(l2cap_channel); 3127 // If UnackedFrames > 0 then Start-RetransTimer 3128 if (l2cap_channel->unacked_frames){ 3129 l2cap_ertm_start_retransmission_timer(l2cap_channel); 3130 } 3131 3132 // final bit set <- response to RR with poll bit set. All not acknowledged packets need to be retransmitted 3133 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 3134 } 3135 break; 3136 case L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT: 3137 log_info("L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT"); 3138 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 3139 // rsetart transmittion from last unacknowledted packet (earlier packets already freed in l2cap_ertm_process_req_seq) 3140 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 3141 break; 3142 case L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY: 3143 log_error("L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY"); 3144 break; 3145 case L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT: 3146 log_info("L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT"); 3147 if (poll){ 3148 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 3149 } 3150 // find requested i-frame 3151 tx_state = l2cap_ertm_get_tx_state(l2cap_channel, req_seq); 3152 if (tx_state){ 3153 log_info("Retransmission for tx_seq %u requested", req_seq); 3154 l2cap_channel->set_final_bit_after_packet_with_poll_bit_set = poll; 3155 tx_state->retransmission_requested = 1; 3156 l2cap_channel->srej_active = 1; 3157 } 3158 break; 3159 default: 3160 break; 3161 } 3162 break; 3163 } else { 3164 // I-Frame 3165 // get control 3166 l2cap_segmentation_and_reassembly_t sar = (l2cap_segmentation_and_reassembly_t) (control >> 14); 3167 uint8_t tx_seq = (control >> 1) & 0x3f; 3168 log_info("Control: 0x%04x => SAR %u, ReqSeq %02u, R?, TxSeq %02u", control, (int) sar, req_seq, tx_seq); 3169 log_info("SAR: pos %u", l2cap_channel->reassembly_pos); 3170 log_info("State: expected_tx_seq %02u, req_seq %02u", l2cap_channel->expected_tx_seq, l2cap_channel->req_seq); 3171 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 3172 if (final){ 3173 // final bit set <- response to RR with poll bit set. All not acknowledged packets need to be retransmitted 3174 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 3175 } 3176 3177 // get SDU 3178 const uint8_t * sdu_data = &packet[COMPLETE_L2CAP_HEADER+2]; 3179 uint16_t sdu_len = size-(COMPLETE_L2CAP_HEADER+2+fcs_size); 3180 3181 // assert SDU size is smaller or equal to our buffers 3182 if (sdu_len > l2cap_channel->local_mps) break; 3183 3184 // check ordering 3185 if (l2cap_channel->expected_tx_seq == tx_seq){ 3186 log_info("Received expected frame with TxSeq == ExpectedTxSeq == %02u", tx_seq); 3187 l2cap_channel->expected_tx_seq = l2cap_next_ertm_seq_nr(l2cap_channel->expected_tx_seq); 3188 l2cap_channel->req_seq = l2cap_channel->expected_tx_seq; 3189 3190 // process SDU 3191 l2cap_ertm_handle_in_sequence_sdu(l2cap_channel, sar, sdu_data, sdu_len); 3192 3193 // process stored segments 3194 while (1){ 3195 int index = l2cap_channel->rx_store_index; 3196 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 3197 if (!rx_state->valid) break; 3198 3199 log_info("Processing stored frame with TxSeq == ExpectedTxSeq == %02u", l2cap_channel->expected_tx_seq); 3200 l2cap_channel->expected_tx_seq = l2cap_next_ertm_seq_nr(l2cap_channel->expected_tx_seq); 3201 l2cap_channel->req_seq = l2cap_channel->expected_tx_seq; 3202 3203 rx_state->valid = 0; 3204 l2cap_ertm_handle_in_sequence_sdu(l2cap_channel, rx_state->sar, &l2cap_channel->rx_packets_data[index], rx_state->len); 3205 3206 // update rx store index 3207 index++; 3208 if (index >= l2cap_channel->num_rx_buffers){ 3209 index = 0; 3210 } 3211 l2cap_channel->rx_store_index = index; 3212 } 3213 3214 // 3215 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 3216 3217 } else { 3218 int delta = (tx_seq - l2cap_channel->expected_tx_seq) & 0x3f; 3219 if (delta < 2){ 3220 // store segment 3221 l2cap_ertm_handle_out_of_sequence_sdu(l2cap_channel, sar, delta, sdu_data, sdu_len); 3222 3223 log_info("Received unexpected frame TxSeq %u but expected %u -> send S-SREJ", tx_seq, l2cap_channel->expected_tx_seq); 3224 l2cap_channel->send_supervisor_frame_selective_reject = 1; 3225 } else { 3226 log_info("Received unexpected frame TxSeq %u but expected %u -> send S-REJ", tx_seq, l2cap_channel->expected_tx_seq); 3227 l2cap_channel->send_supervisor_frame_reject = 1; 3228 } 3229 } 3230 } 3231 break; 3232 } 3233 #endif 3234 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 3235 } 3236 break; 3237 } 3238 #else 3239 UNUSED(handle); // ok: no code 3240 UNUSED(packet); // ok: no code 3241 UNUSED(size); // ok: no code 3242 #endif 3243 } 3244 3245 static void l2cap_acl_le_handler(hci_con_handle_t handle, uint8_t *packet, uint16_t size){ 3246 #ifdef ENABLE_BLE 3247 3248 l2cap_fixed_channel_t * l2cap_fixed_channel; 3249 3250 #ifdef ENABLE_LE_DATA_CHANNELS 3251 l2cap_channel_t * l2cap_channel; 3252 #endif 3253 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 3254 switch (channel_id) { 3255 3256 case L2CAP_CID_SIGNALING_LE: { 3257 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 3258 uint16_t len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER + 2); 3259 if (COMPLETE_L2CAP_HEADER + 4 + len > size) break; 3260 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 3261 if (!valid){ 3262 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 3263 } 3264 break; 3265 } 3266 3267 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 3268 l2cap_fixed_channel = l2cap_fixed_channel_for_channel_id(L2CAP_CID_ATTRIBUTE_PROTOCOL); 3269 if (!l2cap_fixed_channel) break; 3270 if (!l2cap_fixed_channel->packet_handler) break; 3271 (*l2cap_fixed_channel->packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 3272 break; 3273 3274 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 3275 l2cap_fixed_channel = l2cap_fixed_channel_for_channel_id(L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3276 if (!l2cap_fixed_channel) break; 3277 if (!l2cap_fixed_channel->packet_handler) break; 3278 (*l2cap_fixed_channel->packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 3279 break; 3280 3281 default: 3282 3283 #ifdef ENABLE_LE_DATA_CHANNELS 3284 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 3285 if (l2cap_channel) { 3286 // credit counting 3287 if (l2cap_channel->credits_incoming == 0){ 3288 log_error("LE Data Channel packet received but no incoming credits"); 3289 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3290 break; 3291 } 3292 l2cap_channel->credits_incoming--; 3293 3294 // automatic credits 3295 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 3296 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 3297 } 3298 3299 // first fragment 3300 uint16_t pos = 0; 3301 if (!l2cap_channel->receive_sdu_len){ 3302 uint16_t sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 3303 if(sdu_len > l2cap_channel->local_mtu) break; // SDU would be larger than our buffer 3304 l2cap_channel->receive_sdu_len = sdu_len; 3305 l2cap_channel->receive_sdu_pos = 0; 3306 pos += 2; 3307 size -= 2; 3308 } 3309 uint16_t fragment_size = size-COMPLETE_L2CAP_HEADER; 3310 uint16_t remaining_space = l2cap_channel->local_mtu - l2cap_channel->receive_sdu_pos; 3311 if (fragment_size > remaining_space) break; // SDU would cause buffer overrun 3312 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], fragment_size); 3313 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 3314 // done? 3315 log_debug("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 3316 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 3317 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 3318 l2cap_channel->receive_sdu_len = 0; 3319 } 3320 } else { 3321 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 3322 } 3323 #endif 3324 break; 3325 } 3326 #else 3327 UNUSED(handle); // ok: no code 3328 UNUSED(packet); // ok: no code 3329 UNUSED(size); // ok: no code 3330 #endif 3331 } 3332 3333 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3334 UNUSED(packet_type); // ok: registered with hci_register_acl_packet_handler 3335 UNUSED(channel); // ok: there is no channel 3336 3337 // Assert full L2CAP header present 3338 if (size < COMPLETE_L2CAP_HEADER) return; 3339 3340 // Dispatch to Classic or LE handler 3341 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 3342 hci_connection_t *conn = hci_connection_for_handle(handle); 3343 if (!conn) return; 3344 if (conn->address_type == BD_ADDR_TYPE_CLASSIC){ 3345 l2cap_acl_classic_handler(handle, packet, size); 3346 } else { 3347 l2cap_acl_le_handler(handle, packet, size); 3348 } 3349 3350 l2cap_run(); 3351 } 3352 3353 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 3354 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 3355 l2cap_fixed_channel_t * channel = l2cap_fixed_channel_for_channel_id(channel_id); 3356 if (!channel) return; 3357 channel->packet_handler = the_packet_handler; 3358 } 3359 3360 #ifdef ENABLE_CLASSIC 3361 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 3362 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 3363 channel->state = L2CAP_STATE_CLOSED; 3364 l2cap_emit_channel_closed(channel); 3365 // discard channel 3366 l2cap_stop_rtx(channel); 3367 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 3368 btstack_memory_l2cap_channel_free(channel); 3369 } 3370 #endif 3371 3372 #ifdef L2CAP_USES_CHANNELS 3373 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 3374 btstack_linked_list_iterator_t it; 3375 btstack_linked_list_iterator_init(&it, services); 3376 while (btstack_linked_list_iterator_has_next(&it)){ 3377 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 3378 if ( service->psm == psm){ 3379 return service; 3380 }; 3381 } 3382 return NULL; 3383 } 3384 #endif 3385 3386 #ifdef ENABLE_CLASSIC 3387 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 3388 return l2cap_get_service_internal(&l2cap_services, psm); 3389 } 3390 3391 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 3392 3393 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 3394 3395 // check for alread registered psm 3396 l2cap_service_t *service = l2cap_get_service(psm); 3397 if (service) { 3398 log_error("l2cap_register_service: PSM %u already registered", psm); 3399 return L2CAP_SERVICE_ALREADY_REGISTERED; 3400 } 3401 3402 // alloc structure 3403 service = btstack_memory_l2cap_service_get(); 3404 if (!service) { 3405 log_error("l2cap_register_service: no memory for l2cap_service_t"); 3406 return BTSTACK_MEMORY_ALLOC_FAILED; 3407 } 3408 3409 // fill in 3410 service->psm = psm; 3411 service->mtu = mtu; 3412 service->packet_handler = service_packet_handler; 3413 service->required_security_level = security_level; 3414 3415 // add to services list 3416 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 3417 3418 // enable page scan 3419 gap_connectable_control(1); 3420 3421 return 0; 3422 } 3423 3424 uint8_t l2cap_unregister_service(uint16_t psm){ 3425 3426 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 3427 3428 l2cap_service_t *service = l2cap_get_service(psm); 3429 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 3430 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 3431 btstack_memory_l2cap_service_free(service); 3432 3433 // disable page scan when no services registered 3434 if (btstack_linked_list_empty(&l2cap_services)) { 3435 gap_connectable_control(0); 3436 } 3437 return 0; 3438 } 3439 #endif 3440 3441 3442 #ifdef ENABLE_LE_DATA_CHANNELS 3443 3444 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 3445 if (!channel->waiting_for_can_send_now) return; 3446 if (channel->send_sdu_buffer) return; 3447 channel->waiting_for_can_send_now = 0; 3448 log_debug("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 3449 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 3450 } 3451 3452 // 1BH2222 3453 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 3454 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", 3455 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 3456 uint8_t event[19]; 3457 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 3458 event[1] = sizeof(event) - 2; 3459 event[2] = channel->address_type; 3460 reverse_bd_addr(channel->address, &event[3]); 3461 little_endian_store_16(event, 9, channel->con_handle); 3462 little_endian_store_16(event, 11, channel->psm); 3463 little_endian_store_16(event, 13, channel->local_cid); 3464 little_endian_store_16(event, 15, channel->remote_cid); 3465 little_endian_store_16(event, 17, channel->remote_mtu); 3466 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 3467 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 3468 } 3469 // 11BH22222 3470 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 3471 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", 3472 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 3473 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 3474 uint8_t event[23]; 3475 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 3476 event[1] = sizeof(event) - 2; 3477 event[2] = status; 3478 event[3] = channel->address_type; 3479 reverse_bd_addr(channel->address, &event[4]); 3480 little_endian_store_16(event, 10, channel->con_handle); 3481 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 3482 little_endian_store_16(event, 13, channel->psm); 3483 little_endian_store_16(event, 15, channel->local_cid); 3484 little_endian_store_16(event, 17, channel->remote_cid); 3485 little_endian_store_16(event, 19, channel->local_mtu); 3486 little_endian_store_16(event, 21, channel->remote_mtu); 3487 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 3488 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 3489 } 3490 // 2 3491 static void l2cap_emit_le_channel_closed(l2cap_channel_t * channel){ 3492 log_info("L2CAP_EVENT_LE_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 3493 uint8_t event[4]; 3494 event[0] = L2CAP_EVENT_LE_CHANNEL_CLOSED; 3495 event[1] = sizeof(event) - 2; 3496 little_endian_store_16(event, 2, channel->local_cid); 3497 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 3498 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 3499 } 3500 3501 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 3502 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 3503 channel->state = L2CAP_STATE_CLOSED; 3504 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 3505 // discard channel 3506 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 3507 btstack_memory_l2cap_channel_free(channel); 3508 } 3509 3510 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 3511 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 3512 } 3513 3514 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 3515 3516 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 3517 3518 // check for alread registered psm 3519 l2cap_service_t *service = l2cap_le_get_service(psm); 3520 if (service) { 3521 return L2CAP_SERVICE_ALREADY_REGISTERED; 3522 } 3523 3524 // alloc structure 3525 service = btstack_memory_l2cap_service_get(); 3526 if (!service) { 3527 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 3528 return BTSTACK_MEMORY_ALLOC_FAILED; 3529 } 3530 3531 // fill in 3532 service->psm = psm; 3533 service->mtu = 0; 3534 service->packet_handler = packet_handler; 3535 service->required_security_level = security_level; 3536 3537 // add to services list 3538 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 3539 3540 // done 3541 return 0; 3542 } 3543 3544 uint8_t l2cap_le_unregister_service(uint16_t psm) { 3545 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 3546 l2cap_service_t *service = l2cap_le_get_service(psm); 3547 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 3548 3549 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 3550 btstack_memory_l2cap_service_free(service); 3551 return 0; 3552 } 3553 3554 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 3555 // get channel 3556 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 3557 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3558 3559 // validate state 3560 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 3561 return ERROR_CODE_COMMAND_DISALLOWED; 3562 } 3563 3564 // set state accept connection 3565 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 3566 channel->receive_sdu_buffer = receive_sdu_buffer; 3567 channel->local_mtu = mtu; 3568 channel->new_credits_incoming = initial_credits; 3569 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 3570 3571 // test 3572 // channel->new_credits_incoming = 1; 3573 3574 // go 3575 l2cap_run(); 3576 return 0; 3577 } 3578 3579 /** 3580 * @brief Deny incoming LE Data Channel connection due to resource constraints 3581 * @param local_cid L2CAP LE Data Channel Identifier 3582 */ 3583 3584 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 3585 // get channel 3586 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 3587 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3588 3589 // validate state 3590 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 3591 return ERROR_CODE_COMMAND_DISALLOWED; 3592 } 3593 3594 // set state decline connection 3595 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 3596 channel->reason = 0x04; // no resources available 3597 l2cap_run(); 3598 return 0; 3599 } 3600 3601 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 3602 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 3603 uint16_t * out_local_cid) { 3604 3605 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 3606 3607 3608 hci_connection_t * connection = hci_connection_for_handle(con_handle); 3609 if (!connection) { 3610 log_error("no hci_connection for handle 0x%04x", con_handle); 3611 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 3612 } 3613 3614 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, L2CAP_CHANNEL_TYPE_LE_DATA_CHANNEL, connection->address, connection->address_type, psm, mtu, security_level); 3615 if (!channel) { 3616 return BTSTACK_MEMORY_ALLOC_FAILED; 3617 } 3618 log_info("l2cap_le_create_channel %p", channel); 3619 3620 // store local_cid 3621 if (out_local_cid){ 3622 *out_local_cid = channel->local_cid; 3623 } 3624 3625 // provide buffer 3626 channel->con_handle = con_handle; 3627 channel->receive_sdu_buffer = receive_sdu_buffer; 3628 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 3629 channel->new_credits_incoming = initial_credits; 3630 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 3631 3632 // add to connections list 3633 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 3634 3635 // go 3636 l2cap_run(); 3637 return 0; 3638 } 3639 3640 /** 3641 * @brief Provide credtis for LE Data Channel 3642 * @param local_cid L2CAP LE Data Channel Identifier 3643 * @param credits Number additional credits for peer 3644 */ 3645 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 3646 3647 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 3648 if (!channel) { 3649 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 3650 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3651 } 3652 3653 // check state 3654 if (channel->state != L2CAP_STATE_OPEN){ 3655 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 3656 } 3657 3658 // assert incoming credits + credits <= 0xffff 3659 uint32_t total_credits = channel->credits_incoming; 3660 total_credits += channel->new_credits_incoming; 3661 total_credits += credits; 3662 if (total_credits > 0xffff){ 3663 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 3664 channel->new_credits_incoming, credits); 3665 } 3666 3667 // set credits_granted 3668 channel->new_credits_incoming += credits; 3669 3670 // go 3671 l2cap_run(); 3672 return 0; 3673 } 3674 3675 /** 3676 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 3677 * @param local_cid L2CAP LE Data Channel Identifier 3678 */ 3679 int l2cap_le_can_send_now(uint16_t local_cid){ 3680 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 3681 if (!channel) { 3682 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 3683 return 0; 3684 } 3685 3686 // check state 3687 if (channel->state != L2CAP_STATE_OPEN) return 0; 3688 3689 // check queue 3690 if (channel->send_sdu_buffer) return 0; 3691 3692 // fine, go ahead 3693 return 1; 3694 } 3695 3696 /** 3697 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 3698 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 3699 * so packet handler should be ready to handle it 3700 * @param local_cid L2CAP LE Data Channel Identifier 3701 */ 3702 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 3703 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 3704 if (!channel) { 3705 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 3706 return 0; 3707 } 3708 channel->waiting_for_can_send_now = 1; 3709 l2cap_le_notify_channel_can_send(channel); 3710 return 0; 3711 } 3712 3713 /** 3714 * @brief Send data via LE Data Channel 3715 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 3716 * @param local_cid L2CAP LE Data Channel Identifier 3717 * @param data data to send 3718 * @param size data size 3719 */ 3720 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 3721 3722 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 3723 if (!channel) { 3724 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 3725 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3726 } 3727 3728 if (len > channel->remote_mtu){ 3729 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 3730 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 3731 } 3732 3733 if (channel->send_sdu_buffer){ 3734 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 3735 return BTSTACK_ACL_BUFFERS_FULL; 3736 } 3737 3738 channel->send_sdu_buffer = data; 3739 channel->send_sdu_len = len; 3740 channel->send_sdu_pos = 0; 3741 3742 l2cap_run(); 3743 return 0; 3744 } 3745 3746 /** 3747 * @brief Disconnect from LE Data Channel 3748 * @param local_cid L2CAP LE Data Channel Identifier 3749 */ 3750 uint8_t l2cap_le_disconnect(uint16_t local_cid) 3751 { 3752 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 3753 if (!channel) { 3754 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 3755 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3756 } 3757 3758 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3759 l2cap_run(); 3760 return 0; 3761 } 3762 3763 #endif 3764