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 static void l2cap_free_channel_entry(l2cap_channel_t * channel); 112 #endif 113 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 114 static void l2cap_ertm_notify_channel_can_send(l2cap_channel_t * channel); 115 static void l2cap_ertm_monitor_timeout_callback(btstack_timer_source_t * ts); 116 static void l2cap_ertm_retransmission_timeout_callback(btstack_timer_source_t * ts); 117 #endif 118 119 // l2cap_fixed_channel_t entries 120 #ifdef ENABLE_BLE 121 static l2cap_fixed_channel_t l2cap_fixed_channel_att; 122 static l2cap_fixed_channel_t l2cap_fixed_channel_sm; 123 #endif 124 #ifdef ENABLE_CLASSIC 125 static l2cap_fixed_channel_t l2cap_fixed_channel_connectionless; 126 #endif 127 128 #ifdef ENABLE_CLASSIC 129 static btstack_linked_list_t l2cap_services; 130 static uint8_t require_security_level2_for_outgoing_sdp; 131 static bd_addr_t l2cap_outgoing_classic_addr; 132 #endif 133 134 #ifdef ENABLE_LE_DATA_CHANNELS 135 static btstack_linked_list_t l2cap_le_services; 136 #endif 137 138 // single list of channels for Classic Channels, LE Data Channels, Classic Connectionless, ATT, and SM 139 static btstack_linked_list_t l2cap_channels; 140 141 // used to cache l2cap rejects, echo, and informational requests 142 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 143 static int signaling_responses_pending; 144 static btstack_packet_callback_registration_t hci_event_callback_registration; 145 146 #ifdef ENABLE_BLE 147 // only used for connection parameter update events 148 static btstack_packet_handler_t l2cap_event_packet_handler; 149 static uint16_t l2cap_le_custom_max_mtu; 150 #endif 151 152 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 153 154 // enable for testing 155 // #define L2CAP_ERTM_SIMULATE_FCS_ERROR_INTERVAL 16 156 157 /* 158 * CRC lookup table for generator polynom D^16 + D^15 + D^2 + 1 159 */ 160 static const uint16_t crc16_table[256] = { 161 0x0000, 0xc0c1, 0xc181, 0x0140, 0xc301, 0x03c0, 0x0280, 0xc241, 0xc601, 0x06c0, 0x0780, 0xc741, 0x0500, 0xc5c1, 0xc481, 0x0440, 162 0xcc01, 0x0cc0, 0x0d80, 0xcd41, 0x0f00, 0xcfc1, 0xce81, 0x0e40, 0x0a00, 0xcac1, 0xcb81, 0x0b40, 0xc901, 0x09c0, 0x0880, 0xc841, 163 0xd801, 0x18c0, 0x1980, 0xd941, 0x1b00, 0xdbc1, 0xda81, 0x1a40, 0x1e00, 0xdec1, 0xdf81, 0x1f40, 0xdd01, 0x1dc0, 0x1c80, 0xdc41, 164 0x1400, 0xd4c1, 0xd581, 0x1540, 0xd701, 0x17c0, 0x1680, 0xd641, 0xd201, 0x12c0, 0x1380, 0xd341, 0x1100, 0xd1c1, 0xd081, 0x1040, 165 0xf001, 0x30c0, 0x3180, 0xf141, 0x3300, 0xf3c1, 0xf281, 0x3240, 0x3600, 0xf6c1, 0xf781, 0x3740, 0xf501, 0x35c0, 0x3480, 0xf441, 166 0x3c00, 0xfcc1, 0xfd81, 0x3d40, 0xff01, 0x3fc0, 0x3e80, 0xfe41, 0xfa01, 0x3ac0, 0x3b80, 0xfb41, 0x3900, 0xf9c1, 0xf881, 0x3840, 167 0x2800, 0xe8c1, 0xe981, 0x2940, 0xeb01, 0x2bc0, 0x2a80, 0xea41, 0xee01, 0x2ec0, 0x2f80, 0xef41, 0x2d00, 0xedc1, 0xec81, 0x2c40, 168 0xe401, 0x24c0, 0x2580, 0xe541, 0x2700, 0xe7c1, 0xe681, 0x2640, 0x2200, 0xe2c1, 0xe381, 0x2340, 0xe101, 0x21c0, 0x2080, 0xe041, 169 0xa001, 0x60c0, 0x6180, 0xa141, 0x6300, 0xa3c1, 0xa281, 0x6240, 0x6600, 0xa6c1, 0xa781, 0x6740, 0xa501, 0x65c0, 0x6480, 0xa441, 170 0x6c00, 0xacc1, 0xad81, 0x6d40, 0xaf01, 0x6fc0, 0x6e80, 0xae41, 0xaa01, 0x6ac0, 0x6b80, 0xab41, 0x6900, 0xa9c1, 0xa881, 0x6840, 171 0x7800, 0xb8c1, 0xb981, 0x7940, 0xbb01, 0x7bc0, 0x7a80, 0xba41, 0xbe01, 0x7ec0, 0x7f80, 0xbf41, 0x7d00, 0xbdc1, 0xbc81, 0x7c40, 172 0xb401, 0x74c0, 0x7580, 0xb541, 0x7700, 0xb7c1, 0xb681, 0x7640, 0x7200, 0xb2c1, 0xb381, 0x7340, 0xb101, 0x71c0, 0x7080, 0xb041, 173 0x5000, 0x90c1, 0x9181, 0x5140, 0x9301, 0x53c0, 0x5280, 0x9241, 0x9601, 0x56c0, 0x5780, 0x9741, 0x5500, 0x95c1, 0x9481, 0x5440, 174 0x9c01, 0x5cc0, 0x5d80, 0x9d41, 0x5f00, 0x9fc1, 0x9e81, 0x5e40, 0x5a00, 0x9ac1, 0x9b81, 0x5b40, 0x9901, 0x59c0, 0x5880, 0x9841, 175 0x8801, 0x48c0, 0x4980, 0x8941, 0x4b00, 0x8bc1, 0x8a81, 0x4a40, 0x4e00, 0x8ec1, 0x8f81, 0x4f40, 0x8d01, 0x4dc0, 0x4c80, 0x8c41, 176 0x4400, 0x84c1, 0x8581, 0x4540, 0x8701, 0x47c0, 0x4680, 0x8641, 0x8201, 0x42c0, 0x4380, 0x8341, 0x4100, 0x81c1, 0x8081, 0x4040, 177 }; 178 179 static uint16_t crc16_calc(uint8_t * data, uint16_t len){ 180 uint16_t crc = 0; // initial value = 0 181 while (len--){ 182 crc = (crc >> 8) ^ crc16_table[ (crc ^ ((uint16_t) *data++)) & 0x00FF ]; 183 } 184 return crc; 185 } 186 187 static inline uint16_t l2cap_encanced_control_field_for_information_frame(uint8_t tx_seq, int final, uint8_t req_seq, l2cap_segmentation_and_reassembly_t sar){ 188 return (((uint16_t) sar) << 14) | (req_seq << 8) | (final << 7) | (tx_seq << 1) | 0; 189 } 190 191 static inline uint16_t l2cap_encanced_control_field_for_supevisor_frame(l2cap_supervisory_function_t supervisory_function, int poll, int final, uint8_t req_seq){ 192 return (req_seq << 8) | (final << 7) | (poll << 4) | (((int) supervisory_function) << 2) | 1; 193 } 194 195 static int l2cap_next_ertm_seq_nr(int seq_nr){ 196 return (seq_nr + 1) & 0x3f; 197 } 198 199 static int l2cap_ertm_can_store_packet_now(l2cap_channel_t * channel){ 200 // get num free tx buffers 201 int num_free_tx_buffers = channel->num_tx_buffers - channel->num_stored_tx_frames; 202 // calculate num tx buffers for remote MTU 203 int num_tx_buffers_for_max_remote_mtu; 204 if (channel->remote_mtu <= channel->remote_mps){ 205 // MTU fits into single packet 206 num_tx_buffers_for_max_remote_mtu = 1; 207 } else { 208 // include SDU Length 209 num_tx_buffers_for_max_remote_mtu = (channel->remote_mtu + 2 + (channel->remote_mps - 1)) / channel->remote_mps; 210 } 211 log_debug("num_free_tx_buffers %u, num_tx_buffers_for_max_remote_mtu %u", num_free_tx_buffers, num_tx_buffers_for_max_remote_mtu); 212 return num_tx_buffers_for_max_remote_mtu <= num_free_tx_buffers; 213 } 214 215 static void l2cap_ertm_retransmit_unacknowleded_frames(l2cap_channel_t * l2cap_channel){ 216 log_info("Retransmit unacknowleged frames"); 217 l2cap_channel->unacked_frames = 0;; 218 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 219 } 220 221 static void l2cap_ertm_next_tx_write_index(l2cap_channel_t * channel){ 222 channel->tx_write_index++; 223 if (channel->tx_write_index < channel->num_tx_buffers) return; 224 channel->tx_write_index = 0; 225 } 226 227 static void l2cap_ertm_start_monitor_timer(l2cap_channel_t * channel){ 228 log_info("Start Monitor timer"); 229 btstack_run_loop_remove_timer(&channel->monitor_timer); 230 btstack_run_loop_set_timer_handler(&channel->monitor_timer, &l2cap_ertm_monitor_timeout_callback); 231 btstack_run_loop_set_timer_context(&channel->monitor_timer, channel); 232 btstack_run_loop_set_timer(&channel->monitor_timer, channel->local_monitor_timeout_ms); 233 btstack_run_loop_add_timer(&channel->monitor_timer); 234 } 235 236 static void l2cap_ertm_stop_monitor_timer(l2cap_channel_t * channel){ 237 log_info("Stop Monitor timer"); 238 btstack_run_loop_remove_timer(&channel->monitor_timer); 239 } 240 241 static void l2cap_ertm_start_retransmission_timer(l2cap_channel_t * channel){ 242 log_info("Start Retransmission timer"); 243 btstack_run_loop_remove_timer(&channel->retransmission_timer); 244 btstack_run_loop_set_timer_handler(&channel->retransmission_timer, &l2cap_ertm_retransmission_timeout_callback); 245 btstack_run_loop_set_timer_context(&channel->retransmission_timer, channel); 246 btstack_run_loop_set_timer(&channel->retransmission_timer, channel->local_retransmission_timeout_ms); 247 btstack_run_loop_add_timer(&channel->retransmission_timer); 248 } 249 250 static void l2cap_ertm_stop_retransmission_timer(l2cap_channel_t * l2cap_channel){ 251 log_info("Stop Retransmission timer"); 252 btstack_run_loop_remove_timer(&l2cap_channel->retransmission_timer); 253 } 254 255 static void l2cap_ertm_monitor_timeout_callback(btstack_timer_source_t * ts){ 256 log_info("Monitor timeout"); 257 l2cap_channel_t * l2cap_channel = (l2cap_channel_t *) btstack_run_loop_get_timer_context(ts); 258 259 // TODO: we assume that it's the oldest packet 260 l2cap_ertm_tx_packet_state_t * tx_state; 261 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 262 263 // check retry count 264 if (tx_state->retry_count < l2cap_channel->remote_max_transmit){ 265 // increment retry count 266 tx_state->retry_count++; 267 268 // start retransmit 269 l2cap_ertm_retransmit_unacknowleded_frames(l2cap_channel); 270 271 // start monitor timer 272 l2cap_ertm_start_monitor_timer(l2cap_channel); 273 274 // send RR/P=1 275 l2cap_channel->send_supervisor_frame_receiver_ready_poll = 1; 276 } else { 277 log_info("Monitor timer expired & retry count >= max transmit -> disconnect"); 278 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 279 } 280 l2cap_run(); 281 } 282 283 static void l2cap_ertm_retransmission_timeout_callback(btstack_timer_source_t * ts){ 284 log_info("Retransmission timeout"); 285 l2cap_channel_t * l2cap_channel = (l2cap_channel_t *) btstack_run_loop_get_timer_context(ts); 286 287 // TODO: we assume that it's the oldest packet 288 l2cap_ertm_tx_packet_state_t * tx_state; 289 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 290 291 // set retry count = 1 292 tx_state->retry_count = 1; 293 294 // start retransmit 295 l2cap_ertm_retransmit_unacknowleded_frames(l2cap_channel); 296 297 // start monitor timer 298 l2cap_ertm_start_monitor_timer(l2cap_channel); 299 300 // send RR/P=1 301 l2cap_channel->send_supervisor_frame_receiver_ready_poll = 1; 302 l2cap_run(); 303 } 304 305 static int l2cap_ertm_send_information_frame(l2cap_channel_t * channel, int index, int final){ 306 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[index]; 307 hci_reserve_packet_buffer(); 308 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 309 uint16_t control = l2cap_encanced_control_field_for_information_frame(tx_state->tx_seq, final, channel->req_seq, tx_state->sar); 310 log_info("I-Frame: control 0x%04x", control); 311 little_endian_store_16(acl_buffer, 8, control); 312 memcpy(&acl_buffer[8+2], &channel->tx_packets_data[index * channel->local_mps], tx_state->len); 313 // (re-)start retransmission timer on 314 l2cap_ertm_start_retransmission_timer(channel); 315 // send 316 return l2cap_send_prepared(channel->local_cid, 2 + tx_state->len); 317 } 318 319 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){ 320 // get next index for storing packets 321 int index = channel->tx_write_index; 322 323 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[index]; 324 tx_state->tx_seq = channel->next_tx_seq; 325 tx_state->len = len; 326 tx_state->sar = sar; 327 tx_state->retry_count = 0; 328 329 uint8_t * tx_packet = &channel->tx_packets_data[index * channel->local_mps]; 330 log_debug("index %u, mtu %u, packet tx %p", index, channel->local_mtu, tx_packet); 331 int pos = 0; 332 if (sar == L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU){ 333 little_endian_store_16(tx_packet, 0, sdu_length); 334 pos += 2; 335 } 336 memcpy(&tx_packet[pos], data, len); 337 338 // update 339 channel->num_stored_tx_frames++; 340 channel->next_tx_seq = l2cap_next_ertm_seq_nr(channel->next_tx_seq); 341 l2cap_ertm_next_tx_write_index(channel); 342 343 log_info("l2cap_ertm_store_fragment: tx_read_index %u, tx_write_index %u, num stored %u", channel->tx_read_index, channel->tx_write_index, channel->num_stored_tx_frames); 344 345 } 346 347 static int l2cap_ertm_send(l2cap_channel_t * channel, uint8_t * data, uint16_t len){ 348 if (len > channel->remote_mtu){ 349 log_error("l2cap_ertm_send cid 0x%02x, data length exceeds remote MTU.", channel->local_cid); 350 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 351 } 352 353 if (!l2cap_ertm_can_store_packet_now(channel)){ 354 log_error("l2cap_ertm_send cid 0x%02x, fragment store full", channel->local_cid); 355 return BTSTACK_ACL_BUFFERS_FULL; 356 } 357 358 // check if it needs to get fragmented 359 if (len > channel->remote_mps){ 360 // fragmentation needed. 361 l2cap_segmentation_and_reassembly_t sar = L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU; 362 int chunk_len; 363 while (len){ 364 switch (sar){ 365 case L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU: 366 chunk_len = channel->remote_mps - 2; // sdu_length 367 l2cap_ertm_store_fragment(channel, sar, len, data, chunk_len); 368 len -= chunk_len; 369 sar = L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU; 370 break; 371 case L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU: 372 chunk_len = channel->remote_mps; 373 if (chunk_len >= len){ 374 sar = L2CAP_SEGMENTATION_AND_REASSEMBLY_END_OF_L2CAP_SDU; 375 chunk_len = len; 376 } 377 l2cap_ertm_store_fragment(channel, sar, len, data, chunk_len); 378 len -= chunk_len; 379 break; 380 default: 381 break; 382 } 383 } 384 385 } else { 386 l2cap_ertm_store_fragment(channel, L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU, 0, data, len); 387 } 388 389 // try to send 390 l2cap_run(); 391 return 0; 392 } 393 394 static uint16_t l2cap_setup_options_ertm_request(l2cap_channel_t * channel, uint8_t * config_options){ 395 int pos = 0; 396 config_options[pos++] = L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL; 397 config_options[pos++] = 9; // length 398 config_options[pos++] = (uint8_t) channel->mode; 399 config_options[pos++] = channel->num_rx_buffers; // == TxWindows size 400 config_options[pos++] = channel->local_max_transmit; 401 little_endian_store_16( config_options, pos, channel->local_retransmission_timeout_ms); 402 pos += 2; 403 little_endian_store_16( config_options, pos, channel->local_monitor_timeout_ms); 404 pos += 2; 405 little_endian_store_16( config_options, pos, channel->local_mps); 406 pos += 2; 407 // 408 config_options[pos++] = L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT; 409 config_options[pos++] = 2; // length 410 little_endian_store_16(config_options, pos, channel->local_mtu); 411 pos += 2; 412 413 // Issue: iOS (e.g. 10.2) uses "No FCS" as default while Core 5.0 specifies "FCS" as default 414 // Workaround: try to actively negotiate FCS option 415 config_options[pos++] = L2CAP_CONFIG_OPTION_TYPE_FRAME_CHECK_SEQUENCE; 416 config_options[pos++] = 1; // length 417 config_options[pos++] = channel->fcs_option; 418 return pos; // 11+4+3=18 419 } 420 421 static uint16_t l2cap_setup_options_ertm_response(l2cap_channel_t * channel, uint8_t * config_options){ 422 int pos = 0; 423 config_options[pos++] = L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL; 424 config_options[pos++] = 9; // length 425 config_options[pos++] = (uint8_t) channel->mode; 426 // less or equal to remote tx window size 427 config_options[pos++] = btstack_min(channel->num_tx_buffers, channel->remote_tx_window_size); 428 // max transmit in response shall be ignored -> use sender values 429 config_options[pos++] = channel->remote_max_transmit; 430 // A value for the Retransmission time-out shall be sent in a positive Configuration Response 431 // and indicates the value that will be used by the sender of the Configuration Response -> use our value 432 little_endian_store_16( config_options, pos, channel->local_retransmission_timeout_ms); 433 pos += 2; 434 // A value for the Monitor time-out shall be sent in a positive Configuration Response 435 // and indicates the value that will be used by the sender of the Configuration Response -> use our value 436 little_endian_store_16( config_options, pos, channel->local_monitor_timeout_ms); 437 pos += 2; 438 // less or equal to remote mps 439 little_endian_store_16( config_options, pos, btstack_min(channel->local_mps, channel->remote_mps)); 440 pos += 2; 441 // 442 config_options[pos++] = L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT; // MTU 443 config_options[pos++] = 2; // length 444 little_endian_store_16(config_options, pos, channel->remote_mtu); 445 pos += 2; 446 #if 0 447 // 448 config_options[pos++] = L2CAP_CONFIG_OPTION_TYPE_FRAME_CHECK_SEQUENCE; 449 config_options[pos++] = 1; // length 450 config_options[pos++] = channel->fcs_option; 451 #endif 452 return pos; // 11+4=15 453 } 454 455 static int l2cap_ertm_send_supervisor_frame(l2cap_channel_t * channel, uint16_t control){ 456 hci_reserve_packet_buffer(); 457 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 458 log_info("S-Frame: control 0x%04x", control); 459 little_endian_store_16(acl_buffer, 8, control); 460 return l2cap_send_prepared(channel->local_cid, 2); 461 } 462 463 static uint8_t l2cap_ertm_validate_local_config(l2cap_ertm_config_t * ertm_config){ 464 465 uint8_t result = ERROR_CODE_SUCCESS; 466 if (ertm_config->max_transmit < 1){ 467 log_error("max_transmit must be >= 1"); 468 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 469 } 470 if (ertm_config->retransmission_timeout_ms < 2000){ 471 log_error("retransmission_timeout_ms must be >= 2000 ms"); 472 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 473 } 474 if (ertm_config->monitor_timeout_ms < 12000){ 475 log_error("monitor_timeout_ms must be >= 12000 ms"); 476 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 477 } 478 if (ertm_config->local_mtu < 48){ 479 log_error("local_mtu must be >= 48"); 480 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 481 } 482 if (ertm_config->num_rx_buffers < 1){ 483 log_error("num_rx_buffers must be >= 1"); 484 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 485 } 486 if (ertm_config->num_tx_buffers < 1){ 487 log_error("num_rx_buffers must be >= 1"); 488 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 489 } 490 return result; 491 } 492 493 static void l2cap_ertm_configure_channel(l2cap_channel_t * channel, l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size){ 494 495 channel->mode = L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION; 496 channel->ertm_mandatory = ertm_config->ertm_mandatory; 497 channel->local_max_transmit = ertm_config->max_transmit; 498 channel->local_retransmission_timeout_ms = ertm_config->retransmission_timeout_ms; 499 channel->local_monitor_timeout_ms = ertm_config->monitor_timeout_ms; 500 channel->local_mtu = ertm_config->local_mtu; 501 channel->num_rx_buffers = ertm_config->num_rx_buffers; 502 channel->num_tx_buffers = ertm_config->num_tx_buffers; 503 504 // align buffer to 16-byte boundary to assert l2cap_ertm_rx_packet_state_t is aligned 505 int bytes_till_alignment = 16 - (((uintptr_t) buffer) & 0x0f); 506 buffer += bytes_till_alignment; 507 size -= bytes_till_alignment; 508 509 // setup state buffers - use void cast to avoid -Wcast-align warning 510 uint32_t pos = 0; 511 channel->rx_packets_state = (l2cap_ertm_rx_packet_state_t *) (void *) &buffer[pos]; 512 pos += ertm_config->num_rx_buffers * sizeof(l2cap_ertm_rx_packet_state_t); 513 channel->tx_packets_state = (l2cap_ertm_tx_packet_state_t *) (void *) &buffer[pos]; 514 pos += ertm_config->num_tx_buffers * sizeof(l2cap_ertm_tx_packet_state_t); 515 516 // setup reassembly buffer 517 channel->reassembly_buffer = &buffer[pos]; 518 pos += ertm_config->local_mtu; 519 520 // divide rest of data equally 521 channel->local_mps = (size - pos) / (ertm_config->num_rx_buffers + ertm_config->num_tx_buffers); 522 log_info("Local MPS: %u", channel->local_mps); 523 channel->rx_packets_data = &buffer[pos]; 524 pos += ertm_config->num_rx_buffers * channel->local_mps; 525 channel->tx_packets_data = &buffer[pos]; 526 527 channel->fcs_option = ertm_config->fcs_option; 528 } 529 530 uint8_t l2cap_create_ertm_channel(btstack_packet_handler_t packet_handler, bd_addr_t address, uint16_t psm, 531 l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size, uint16_t * out_local_cid){ 532 533 log_info("L2CAP_CREATE_ERTM_CHANNEL addr %s, psm 0x%x, local mtu %u", bd_addr_to_str(address), psm, ertm_config->local_mtu); 534 535 // validate local config 536 uint8_t result = l2cap_ertm_validate_local_config(ertm_config); 537 if (result) return result; 538 539 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); 540 if (!channel) { 541 return BTSTACK_MEMORY_ALLOC_FAILED; 542 } 543 544 // configure ERTM 545 l2cap_ertm_configure_channel(channel, ertm_config, buffer, size); 546 547 // add to connections list 548 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 549 550 // store local_cid 551 if (out_local_cid){ 552 *out_local_cid = channel->local_cid; 553 } 554 555 // check if hci connection is already usable 556 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 557 if (conn){ 558 log_info("l2cap_create_channel, hci connection already exists"); 559 l2cap_handle_connection_complete(conn->con_handle, channel); 560 // check if remote supported fearures are already received 561 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 562 l2cap_handle_remote_supported_features_received(channel); 563 } 564 } 565 566 l2cap_run(); 567 568 return 0; 569 } 570 571 static void l2cap_ertm_notify_channel_can_send(l2cap_channel_t * channel){ 572 if (l2cap_ertm_can_store_packet_now(channel)){ 573 channel->waiting_for_can_send_now = 0; 574 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 575 } 576 } 577 578 uint8_t l2cap_accept_ertm_connection(uint16_t local_cid, l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size){ 579 580 log_info("L2CAP_ACCEPT_ERTM_CONNECTION local_cid 0x%x", local_cid); 581 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 582 if (!channel) { 583 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 584 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 585 } 586 587 // validate local config 588 uint8_t result = l2cap_ertm_validate_local_config(ertm_config); 589 if (result) return result; 590 591 // configure L2CAP ERTM 592 l2cap_ertm_configure_channel(channel, ertm_config, buffer, size); 593 594 // continue 595 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 596 597 // process 598 l2cap_run(); 599 600 return ERROR_CODE_SUCCESS; 601 } 602 603 uint8_t l2cap_ertm_set_busy(uint16_t local_cid){ 604 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 605 if (!channel) { 606 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 607 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 608 } 609 if (!channel->local_busy){ 610 channel->local_busy = 1; 611 channel->send_supervisor_frame_receiver_not_ready = 1; 612 l2cap_run(); 613 } 614 return ERROR_CODE_SUCCESS; 615 } 616 617 uint8_t l2cap_ertm_set_ready(uint16_t local_cid){ 618 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 619 if (!channel) { 620 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 621 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 622 } 623 if (channel->local_busy){ 624 channel->local_busy = 0; 625 channel->send_supervisor_frame_receiver_ready_poll = 1; 626 l2cap_run(); 627 } 628 return ERROR_CODE_SUCCESS; 629 } 630 631 // Process-ReqSeq 632 static void l2cap_ertm_process_req_seq(l2cap_channel_t * l2cap_channel, uint8_t req_seq){ 633 int num_buffers_acked = 0; 634 l2cap_ertm_tx_packet_state_t * tx_state; 635 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); 636 while (1){ 637 638 // no unack packets left 639 if (l2cap_channel->unacked_frames == 0) { 640 // stop retransmission timer 641 l2cap_ertm_stop_retransmission_timer(l2cap_channel); 642 break; 643 } 644 645 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 646 // calc delta 647 int delta = (req_seq - tx_state->tx_seq) & 0x03f; 648 if (delta == 0) break; // all packets acknowledged 649 if (delta > l2cap_channel->remote_tx_window_size) break; 650 651 num_buffers_acked++; 652 l2cap_channel->num_stored_tx_frames--; 653 l2cap_channel->unacked_frames--; 654 log_info("RR seq %u => packet with tx_seq %u done", req_seq, tx_state->tx_seq); 655 656 l2cap_channel->tx_read_index++; 657 if (l2cap_channel->tx_read_index >= l2cap_channel->num_rx_buffers){ 658 l2cap_channel->tx_read_index = 0; 659 } 660 } 661 if (num_buffers_acked){ 662 log_info("num_buffers_acked %u", num_buffers_acked); 663 l2cap_ertm_notify_channel_can_send(l2cap_channel); 664 } 665 } 666 667 static l2cap_ertm_tx_packet_state_t * l2cap_ertm_get_tx_state(l2cap_channel_t * l2cap_channel, uint8_t tx_seq){ 668 int i; 669 for (i=0;i<l2cap_channel->num_tx_buffers;i++){ 670 l2cap_ertm_tx_packet_state_t * tx_state = &l2cap_channel->tx_packets_state[i]; 671 if (tx_state->tx_seq == tx_seq) return tx_state; 672 } 673 return NULL; 674 } 675 676 // @param delta number of frames in the future, >= 1 677 // @assumption size <= l2cap_channel->local_mps (checked in l2cap_acl_classic_handler) 678 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){ 679 log_info("Store SDU with delta %u", delta); 680 // get rx state for packet to store 681 int index = l2cap_channel->rx_store_index + delta - 1; 682 if (index > l2cap_channel->num_rx_buffers){ 683 index -= l2cap_channel->num_rx_buffers; 684 } 685 log_info("Index of packet to store %u", index); 686 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 687 // check if buffer is free 688 if (rx_state->valid){ 689 log_error("Packet buffer already used"); 690 return; 691 } 692 rx_state->valid = 1; 693 rx_state->sar = sar; 694 rx_state->len = size; 695 uint8_t * rx_buffer = &l2cap_channel->rx_packets_data[index]; 696 memcpy(rx_buffer, payload, size); 697 } 698 699 // @assumption size <= l2cap_channel->local_mps (checked in l2cap_acl_classic_handler) 700 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){ 701 uint16_t reassembly_sdu_length; 702 switch (sar){ 703 case L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU: 704 // assert total packet size <= our mtu 705 if (size > l2cap_channel->local_mtu) break; 706 // packet complete -> disapatch 707 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, (uint8_t*) payload, size); 708 break; 709 case L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU: 710 // read SDU len 711 reassembly_sdu_length = little_endian_read_16(payload, 0); 712 payload += 2; 713 size -= 2; 714 // assert reassembled size <= our mtu 715 if (reassembly_sdu_length > l2cap_channel->local_mtu) break; 716 // store start segment 717 l2cap_channel->reassembly_sdu_length = reassembly_sdu_length; 718 memcpy(&l2cap_channel->reassembly_buffer[0], payload, size); 719 l2cap_channel->reassembly_pos = size; 720 break; 721 case L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU: 722 // assert size of reassembled data <= our mtu 723 if (l2cap_channel->reassembly_pos + size > l2cap_channel->local_mtu) break; 724 // store continuation segment 725 memcpy(&l2cap_channel->reassembly_buffer[l2cap_channel->reassembly_pos], payload, size); 726 l2cap_channel->reassembly_pos += size; 727 break; 728 case L2CAP_SEGMENTATION_AND_REASSEMBLY_END_OF_L2CAP_SDU: 729 // assert size of reassembled data <= our mtu 730 if (l2cap_channel->reassembly_pos + size > l2cap_channel->local_mtu) break; 731 // store continuation segment 732 memcpy(&l2cap_channel->reassembly_buffer[l2cap_channel->reassembly_pos], payload, size); 733 l2cap_channel->reassembly_pos += size; 734 // assert size of reassembled data matches announced sdu length 735 if (l2cap_channel->reassembly_pos != l2cap_channel->reassembly_sdu_length) break; 736 // packet complete -> disapatch 737 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->reassembly_buffer, l2cap_channel->reassembly_pos); 738 l2cap_channel->reassembly_pos = 0; 739 break; 740 } 741 } 742 743 #endif 744 745 void l2cap_init(void){ 746 signaling_responses_pending = 0; 747 748 l2cap_channels = NULL; 749 750 #ifdef ENABLE_CLASSIC 751 l2cap_services = NULL; 752 require_security_level2_for_outgoing_sdp = 0; 753 754 // Setup Connectionless Channel 755 l2cap_fixed_channel_connectionless.local_cid = L2CAP_CID_CONNECTIONLESS_CHANNEL; 756 l2cap_fixed_channel_connectionless.channel_type = L2CAP_CHANNEL_TYPE_CONNECTIONLESS; 757 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) &l2cap_fixed_channel_connectionless); 758 #endif 759 760 #ifdef ENABLE_LE_DATA_CHANNELS 761 l2cap_le_services = NULL; 762 #endif 763 764 #ifdef ENABLE_BLE 765 l2cap_event_packet_handler = NULL; 766 l2cap_le_custom_max_mtu = 0; 767 768 // Setup fixed ATT Channel 769 l2cap_fixed_channel_att.local_cid = L2CAP_CID_ATTRIBUTE_PROTOCOL; 770 l2cap_fixed_channel_att.channel_type = L2CAP_CHANNEL_TYPE_LE_FIXED; 771 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) &l2cap_fixed_channel_att); 772 773 // Setup fixed SM Channel 774 l2cap_fixed_channel_sm.local_cid = L2CAP_CID_SECURITY_MANAGER_PROTOCOL; 775 l2cap_fixed_channel_sm.channel_type = L2CAP_CHANNEL_TYPE_LE_FIXED; 776 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) &l2cap_fixed_channel_sm); 777 #endif 778 779 // 780 // register callback with HCI 781 // 782 hci_event_callback_registration.callback = &l2cap_hci_event_handler; 783 hci_add_event_handler(&hci_event_callback_registration); 784 785 hci_register_acl_packet_handler(&l2cap_acl_handler); 786 787 #ifdef ENABLE_CLASSIC 788 gap_connectable_control(0); // no services yet 789 #endif 790 } 791 792 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 793 #ifdef ENABLE_BLE 794 l2cap_event_packet_handler = handler; 795 #else 796 UNUSED(handler); // ok: no code 797 #endif 798 } 799 800 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ 801 UNUSED(con_handle); // ok: there is no con handle 802 803 l2cap_fixed_channel_t * channel = l2cap_fixed_channel_for_channel_id(channel_id); 804 if (!channel) return; 805 channel->waiting_for_can_send_now = 1; 806 l2cap_notify_channel_can_send(); 807 } 808 809 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ 810 UNUSED(channel_id); // ok: only depends on Controller LE buffers 811 812 return hci_can_send_acl_packet_now(con_handle); 813 } 814 815 uint8_t *l2cap_get_outgoing_buffer(void){ 816 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 817 } 818 819 // only for L2CAP Basic Channels 820 int l2cap_reserve_packet_buffer(void){ 821 return hci_reserve_packet_buffer(); 822 } 823 824 // only for L2CAP Basic Channels 825 void l2cap_release_packet_buffer(void){ 826 hci_release_packet_buffer(); 827 } 828 829 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){ 830 // 0 - Connection handle : PB=pb : BC=00 831 little_endian_store_16(acl_buffer, 0, con_handle | (packet_boundary << 12) | (0 << 14)); 832 // 2 - ACL length 833 little_endian_store_16(acl_buffer, 2, len + 4); 834 // 4 - L2CAP packet length 835 little_endian_store_16(acl_buffer, 4, len + 0); 836 // 6 - L2CAP channel DEST 837 little_endian_store_16(acl_buffer, 6, remote_cid); 838 } 839 840 // assumption - only on LE connections 841 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 842 843 if (!hci_is_packet_buffer_reserved()){ 844 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 845 return BTSTACK_ACL_BUFFERS_FULL; 846 } 847 848 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 849 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 850 return BTSTACK_ACL_BUFFERS_FULL; 851 } 852 853 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 854 855 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 856 l2cap_setup_header(acl_buffer, con_handle, 0, cid, len); 857 // send 858 return hci_send_acl_packet_buffer(len+8); 859 } 860 861 // assumption - only on LE connections 862 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 863 864 if (!hci_can_send_acl_packet_now(con_handle)){ 865 log_info("l2cap_send cid 0x%02x, cannot send", cid); 866 return BTSTACK_ACL_BUFFERS_FULL; 867 } 868 869 hci_reserve_packet_buffer(); 870 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 871 872 memcpy(&acl_buffer[8], data, len); 873 874 return l2cap_send_prepared_connectionless(con_handle, cid, len); 875 } 876 877 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { 878 log_debug("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); 879 uint8_t event[4]; 880 event[0] = L2CAP_EVENT_CAN_SEND_NOW; 881 event[1] = sizeof(event) - 2; 882 little_endian_store_16(event, 2, channel); 883 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 884 packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); 885 } 886 887 #ifdef L2CAP_USES_CHANNELS 888 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 889 (* (channel->packet_handler))(type, channel->local_cid, data, size); 890 } 891 892 static void l2cap_emit_simple_event_with_cid(l2cap_channel_t * channel, uint8_t event_code){ 893 uint8_t event[4]; 894 event[0] = event_code; 895 event[1] = sizeof(event) - 2; 896 little_endian_store_16(event, 2, channel->local_cid); 897 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 898 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 899 } 900 #endif 901 902 #ifdef ENABLE_CLASSIC 903 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 904 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", 905 status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 906 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 907 uint8_t event[26]; 908 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 909 event[1] = sizeof(event) - 2; 910 event[2] = status; 911 reverse_bd_addr(channel->address, &event[3]); 912 little_endian_store_16(event, 9, channel->con_handle); 913 little_endian_store_16(event, 11, channel->psm); 914 little_endian_store_16(event, 13, channel->local_cid); 915 little_endian_store_16(event, 15, channel->remote_cid); 916 little_endian_store_16(event, 17, channel->local_mtu); 917 little_endian_store_16(event, 19, channel->remote_mtu); 918 little_endian_store_16(event, 21, channel->flush_timeout); 919 event[23] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 920 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 921 log_info("ERTM mode %u, fcs enabled %u", channel->mode, channel->fcs_option); 922 event[24] = channel->mode; 923 event[25] = channel->fcs_option; 924 925 #else 926 event[24] = L2CAP_CHANNEL_MODE_BASIC; 927 event[25] = 0; 928 #endif 929 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 930 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 931 } 932 933 static void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 934 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 935 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 936 } 937 938 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel) { 939 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 940 bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); 941 uint8_t event[16]; 942 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 943 event[1] = sizeof(event) - 2; 944 reverse_bd_addr(channel->address, &event[2]); 945 little_endian_store_16(event, 8, channel->con_handle); 946 little_endian_store_16(event, 10, channel->psm); 947 little_endian_store_16(event, 12, channel->local_cid); 948 little_endian_store_16(event, 14, channel->remote_cid); 949 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 950 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 951 } 952 953 static void l2cap_handle_channel_open_failed(l2cap_channel_t * channel, uint8_t status){ 954 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 955 // emit ertm buffer released, as it's not needed. if in basic mode, it was either not allocated or already released 956 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 957 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_ERTM_BUFFER_RELEASED); 958 } 959 #endif 960 l2cap_emit_channel_opened(channel, status); 961 } 962 963 static void l2cap_handle_channel_closed(l2cap_channel_t * channel){ 964 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 965 // emit ertm buffer released, as it's not needed anymore. if in basic mode, it was either not allocated or already released 966 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 967 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_ERTM_BUFFER_RELEASED); 968 } 969 #endif 970 l2cap_emit_channel_closed(channel); 971 } 972 #endif 973 974 static l2cap_fixed_channel_t * l2cap_channel_item_by_cid(uint16_t cid){ 975 btstack_linked_list_iterator_t it; 976 btstack_linked_list_iterator_init(&it, &l2cap_channels); 977 while (btstack_linked_list_iterator_has_next(&it)){ 978 l2cap_fixed_channel_t * channel = (l2cap_fixed_channel_t*) btstack_linked_list_iterator_next(&it); 979 if (channel->local_cid == cid) { 980 return channel; 981 } 982 } 983 return NULL; 984 } 985 986 // used for fixed channels in LE (ATT/SM) and Classic (Connectionless Channel). CID < 0x04 987 static l2cap_fixed_channel_t * l2cap_fixed_channel_for_channel_id(uint16_t local_cid){ 988 if (local_cid >= 0x40) return NULL; 989 return (l2cap_fixed_channel_t*) l2cap_channel_item_by_cid(local_cid); 990 } 991 992 // used for Classic Channels + LE Data Channels. local_cid >= 0x40 993 #ifdef L2CAP_USES_CHANNELS 994 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 995 if (local_cid < 0x40) return NULL; 996 return (l2cap_channel_t*) l2cap_channel_item_by_cid(local_cid); 997 } 998 999 void l2cap_request_can_send_now_event(uint16_t local_cid){ 1000 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 1001 if (!channel) return; 1002 channel->waiting_for_can_send_now = 1; 1003 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1004 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1005 l2cap_ertm_notify_channel_can_send(channel); 1006 return; 1007 } 1008 #endif 1009 l2cap_notify_channel_can_send(); 1010 } 1011 1012 int l2cap_can_send_packet_now(uint16_t local_cid){ 1013 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 1014 if (!channel) return 0; 1015 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1016 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1017 return l2cap_ertm_can_store_packet_now(channel); 1018 } 1019 #endif 1020 return hci_can_send_acl_packet_now(channel->con_handle); 1021 } 1022 1023 int l2cap_can_send_prepared_packet_now(uint16_t local_cid){ 1024 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 1025 if (!channel) return 0; 1026 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1027 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1028 return 0; 1029 } 1030 #endif 1031 return hci_can_send_prepared_acl_packet_now(channel->con_handle); 1032 } 1033 1034 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 1035 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1036 if (channel) { 1037 return channel->remote_mtu; 1038 } 1039 return 0; 1040 } 1041 #endif 1042 1043 #ifdef L2CAP_USES_CHANNELS 1044 static int l2cap_is_dynamic_channel_type(l2cap_channel_type_t channel_type){ 1045 switch (channel_type){ 1046 case L2CAP_CHANNEL_TYPE_CLASSIC: 1047 case L2CAP_CHANNEL_TYPE_LE_DATA_CHANNEL: 1048 return 1; 1049 default: 1050 return 0; 1051 } 1052 } 1053 #endif 1054 1055 static int l2cap_is_le_channel_type(l2cap_channel_type_t channel_type){ 1056 switch (channel_type){ 1057 case L2CAP_CHANNEL_TYPE_LE_FIXED: 1058 case L2CAP_CHANNEL_TYPE_LE_DATA_CHANNEL: 1059 return 1; 1060 default: 1061 return 0; 1062 } 1063 } 1064 1065 #ifdef ENABLE_CLASSIC 1066 // RTX Timer only exist for dynamic channels 1067 static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ 1068 btstack_linked_list_iterator_t it; 1069 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1070 while (btstack_linked_list_iterator_has_next(&it)){ 1071 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1072 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 1073 if (&channel->rtx == ts) { 1074 return channel; 1075 } 1076 } 1077 return NULL; 1078 } 1079 1080 static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ 1081 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 1082 if (!channel) return; 1083 1084 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 1085 1086 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 1087 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 1088 // notify client 1089 l2cap_handle_channel_open_failed(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 1090 1091 // discard channel 1092 // no need to stop timer here, it is removed from list during timer callback 1093 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1094 l2cap_free_channel_entry(channel); 1095 } 1096 1097 #endif 1098 1099 #ifdef L2CAP_USES_CHANNELS 1100 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 1101 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 1102 btstack_run_loop_remove_timer(&channel->rtx); 1103 } 1104 #endif 1105 1106 #ifdef ENABLE_CLASSIC 1107 1108 static void l2cap_start_rtx(l2cap_channel_t * channel){ 1109 l2cap_stop_rtx(channel); 1110 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 1111 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 1112 btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 1113 btstack_run_loop_add_timer(&channel->rtx); 1114 } 1115 1116 static void l2cap_start_ertx(l2cap_channel_t * channel){ 1117 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 1118 l2cap_stop_rtx(channel); 1119 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 1120 btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 1121 btstack_run_loop_add_timer(&channel->rtx); 1122 } 1123 1124 void l2cap_require_security_level_2_for_outgoing_sdp(void){ 1125 require_security_level2_for_outgoing_sdp = 1; 1126 } 1127 1128 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 1129 return (psm == BLUETOOTH_PROTOCOL_SDP) && (!require_security_level2_for_outgoing_sdp); 1130 } 1131 1132 static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, int identifier, ...){ 1133 if (!hci_can_send_acl_packet_now(handle)){ 1134 log_info("l2cap_send_signaling_packet, cannot send"); 1135 return BTSTACK_ACL_BUFFERS_FULL; 1136 } 1137 1138 // log_info("l2cap_send_signaling_packet type %u", cmd); 1139 hci_reserve_packet_buffer(); 1140 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1141 va_list argptr; 1142 va_start(argptr, identifier); 1143 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 1144 va_end(argptr); 1145 // log_info("l2cap_send_signaling_packet con %u!", handle); 1146 return hci_send_acl_packet_buffer(len); 1147 } 1148 1149 // assumption - only on Classic connections 1150 // cannot be used for L2CAP ERTM 1151 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 1152 1153 if (!hci_is_packet_buffer_reserved()){ 1154 log_error("l2cap_send_prepared called without reserving packet first"); 1155 return BTSTACK_ACL_BUFFERS_FULL; 1156 } 1157 1158 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1159 if (!channel) { 1160 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 1161 return -1; // TODO: define error 1162 } 1163 1164 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 1165 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 1166 return BTSTACK_ACL_BUFFERS_FULL; 1167 } 1168 1169 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 1170 1171 int fcs_size = 0; 1172 1173 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1174 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION && channel->fcs_option){ 1175 fcs_size = 2; 1176 } 1177 #endif 1178 1179 // set non-flushable packet boundary flag if supported on Controller 1180 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1181 uint8_t packet_boundary_flag = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 1182 l2cap_setup_header(acl_buffer, channel->con_handle, packet_boundary_flag, channel->remote_cid, len + fcs_size); 1183 1184 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1185 if (fcs_size){ 1186 // calculate FCS over l2cap data 1187 uint16_t fcs = crc16_calc(acl_buffer + 4, 4 + len); 1188 log_info("I-Frame: fcs 0x%04x", fcs); 1189 little_endian_store_16(acl_buffer, 8 + len, fcs); 1190 } 1191 #endif 1192 1193 // send 1194 return hci_send_acl_packet_buffer(len+8+fcs_size); 1195 } 1196 1197 // assumption - only on Classic connections 1198 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 1199 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1200 if (!channel) { 1201 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 1202 return -1; // TODO: define error 1203 } 1204 1205 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1206 // send in ERTM 1207 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1208 return l2cap_ertm_send(channel, data, len); 1209 } 1210 #endif 1211 1212 if (len > channel->remote_mtu){ 1213 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 1214 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 1215 } 1216 1217 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 1218 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 1219 return BTSTACK_ACL_BUFFERS_FULL; 1220 } 1221 1222 hci_reserve_packet_buffer(); 1223 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1224 memcpy(&acl_buffer[8], data, len); 1225 return l2cap_send_prepared(local_cid, len); 1226 } 1227 1228 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ 1229 return l2cap_send_signaling_packet(con_handle, ECHO_REQUEST, 0x77, len, data); 1230 } 1231 1232 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 1233 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 1234 } 1235 1236 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 1237 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 1238 } 1239 #endif 1240 1241 1242 #ifdef ENABLE_BLE 1243 static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, int identifier, ...){ 1244 1245 if (!hci_can_send_acl_packet_now(handle)){ 1246 log_info("l2cap_send_le_signaling_packet, cannot send"); 1247 return BTSTACK_ACL_BUFFERS_FULL; 1248 } 1249 1250 // log_info("l2cap_send_le_signaling_packet type %u", cmd); 1251 hci_reserve_packet_buffer(); 1252 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1253 va_list argptr; 1254 va_start(argptr, identifier); 1255 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 1256 va_end(argptr); 1257 // log_info("l2cap_send_le_signaling_packet con %u!", handle); 1258 return hci_send_acl_packet_buffer(len); 1259 } 1260 #endif 1261 1262 uint16_t l2cap_max_mtu(void){ 1263 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 1264 } 1265 1266 #ifdef ENABLE_BLE 1267 uint16_t l2cap_max_le_mtu(void){ 1268 if (l2cap_le_custom_max_mtu != 0) return l2cap_le_custom_max_mtu; 1269 return l2cap_max_mtu(); 1270 } 1271 1272 void l2cap_set_max_le_mtu(uint16_t max_mtu){ 1273 if (max_mtu < l2cap_max_mtu()){ 1274 l2cap_le_custom_max_mtu = max_mtu; 1275 } 1276 } 1277 #endif 1278 1279 #ifdef ENABLE_CLASSIC 1280 1281 static uint16_t l2cap_setup_options_mtu(uint8_t * config_options, uint16_t mtu){ 1282 config_options[0] = L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT; // MTU 1283 config_options[1] = 2; // len param 1284 little_endian_store_16(config_options, 2, mtu); 1285 return 4; 1286 } 1287 1288 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1289 static int l2cap_ertm_mode(l2cap_channel_t * channel){ 1290 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1291 return ((connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_DONE) 1292 && (connection->l2cap_state.extended_feature_mask & 0x08)); 1293 } 1294 #endif 1295 1296 static uint16_t l2cap_setup_options_request(l2cap_channel_t * channel, uint8_t * config_options){ 1297 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1298 // use ERTM options if supported 1299 if (l2cap_ertm_mode(channel)){ 1300 return l2cap_setup_options_ertm_request(channel, config_options); 1301 } 1302 #endif 1303 uint16_t mtu = channel->local_mtu; 1304 return l2cap_setup_options_mtu(config_options, mtu); 1305 } 1306 1307 static uint16_t l2cap_setup_options_response(l2cap_channel_t * channel, uint8_t * config_options){ 1308 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1309 // use ERTM options if supported 1310 if (l2cap_ertm_mode(channel)){ 1311 return l2cap_setup_options_ertm_response(channel, config_options); 1312 } 1313 #endif 1314 uint16_t mtu = btstack_min(channel->local_mtu, channel->remote_mtu); 1315 return l2cap_setup_options_mtu(config_options, mtu); 1316 } 1317 1318 static uint32_t l2cap_extended_features_mask(void){ 1319 // extended features request supported, features: fixed channels, unicast connectionless data reception 1320 uint32_t features = 0x280; 1321 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1322 features |= 0x0028; 1323 #endif 1324 return features; 1325 } 1326 #endif 1327 1328 // MARK: L2CAP_RUN 1329 // process outstanding signaling tasks 1330 static void l2cap_run(void){ 1331 1332 // log_info("l2cap_run: entered"); 1333 1334 // check pending signaling responses 1335 while (signaling_responses_pending){ 1336 1337 hci_con_handle_t handle = signaling_responses[0].handle; 1338 1339 if (!hci_can_send_acl_packet_now(handle)) break; 1340 1341 uint8_t sig_id = signaling_responses[0].sig_id; 1342 uint8_t response_code = signaling_responses[0].code; 1343 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 1344 #ifdef ENABLE_CLASSIC 1345 uint16_t info_type = signaling_responses[0].data; // INFORMATION_REQUEST 1346 uint16_t source_cid = signaling_responses[0].cid; // CONNECTION_REQUEST 1347 #endif 1348 1349 // remove first item before sending (to avoid sending response mutliple times) 1350 signaling_responses_pending--; 1351 int i; 1352 for (i=0; i < signaling_responses_pending; i++){ 1353 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 1354 } 1355 1356 switch (response_code){ 1357 #ifdef ENABLE_CLASSIC 1358 case CONNECTION_REQUEST: 1359 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, source_cid, 0, result, 0); 1360 // also disconnect if result is 0x0003 - security blocked 1361 if (result == 0x0003){ 1362 hci_disconnect_security_block(handle); 1363 } 1364 break; 1365 case ECHO_REQUEST: 1366 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 1367 break; 1368 case INFORMATION_REQUEST: 1369 switch (info_type){ 1370 case L2CAP_INFO_TYPE_CONNECTIONLESS_MTU: { 1371 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 1372 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 0, sizeof(connectionless_mtu), &connectionless_mtu); 1373 } 1374 break; 1375 case L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED: { 1376 uint32_t features = l2cap_extended_features_mask(); 1377 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 0, sizeof(features), &features); 1378 } 1379 break; 1380 case L2CAP_INFO_TYPE_FIXED_CHANNELS_SUPPORTED: { 1381 uint8_t map[8]; 1382 memset(map, 0, 8); 1383 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 1384 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 0, sizeof(map), &map); 1385 } 1386 break; 1387 default: 1388 // all other types are not supported 1389 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 1, 0, NULL); 1390 break; 1391 } 1392 break; 1393 case COMMAND_REJECT: 1394 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 1395 break; 1396 #endif 1397 #ifdef ENABLE_BLE 1398 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1399 l2cap_send_le_signaling_packet(handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, sig_id, 0, 0, 0, 0, result); 1400 break; 1401 case COMMAND_REJECT_LE: 1402 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 1403 break; 1404 #endif 1405 default: 1406 // should not happen 1407 break; 1408 } 1409 } 1410 1411 #if defined(ENABLE_CLASSIC) || defined(ENABLE_BLE) 1412 btstack_linked_list_iterator_t it; 1413 #endif 1414 1415 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1416 // send l2cap information request if neccessary 1417 hci_connections_get_iterator(&it); 1418 while(btstack_linked_list_iterator_has_next(&it)){ 1419 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1420 if (connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST){ 1421 if (!hci_can_send_acl_packet_now(connection->con_handle)) break; 1422 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W4_EXTENDED_FEATURE_RESPONSE; 1423 uint8_t sig_id = l2cap_next_sig_id(); 1424 uint8_t info_type = L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED; 1425 l2cap_send_signaling_packet(connection->con_handle, INFORMATION_REQUEST, sig_id, info_type); 1426 return; 1427 } 1428 } 1429 #endif 1430 1431 #ifdef ENABLE_CLASSIC 1432 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1433 uint8_t config_options[18]; 1434 #else 1435 uint8_t config_options[10]; 1436 #endif 1437 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1438 while (btstack_linked_list_iterator_has_next(&it)){ 1439 1440 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1441 1442 if (channel->channel_type != L2CAP_CHANNEL_TYPE_CLASSIC) continue; 1443 1444 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 1445 switch (channel->state){ 1446 1447 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1448 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 1449 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1450 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 1451 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 1452 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 1453 } 1454 break; 1455 1456 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1457 if (!hci_can_send_command_packet_now()) break; 1458 // send connection request - set state first 1459 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 1460 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 1461 memcpy(l2cap_outgoing_classic_addr, channel->address, 6); 1462 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 1463 break; 1464 1465 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 1466 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1467 channel->state = L2CAP_STATE_INVALID; 1468 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 1469 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 1470 btstack_linked_list_iterator_remove(&it); 1471 l2cap_free_channel_entry(channel); 1472 break; 1473 1474 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 1475 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1476 channel->state = L2CAP_STATE_CONFIG; 1477 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1478 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 1479 break; 1480 1481 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 1482 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1483 // success, start l2cap handshake 1484 channel->local_sig_id = l2cap_next_sig_id(); 1485 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 1486 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 1487 l2cap_start_rtx(channel); 1488 break; 1489 1490 case L2CAP_STATE_CONFIG: 1491 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1492 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1493 // fallback to basic mode if ERTM requested but not not supported by remote 1494 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1495 if (!l2cap_ertm_mode(channel)){ 1496 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_ERTM_BUFFER_RELEASED); 1497 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1498 } 1499 } 1500 #endif 1501 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 1502 uint16_t flags = 0; 1503 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1504 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 1505 flags = 1; 1506 } else { 1507 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 1508 } 1509 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 1510 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 1511 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 1512 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1513 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED){ 1514 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 1515 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 1516 uint16_t options_size = l2cap_setup_options_response(channel, config_options); 1517 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); 1518 #endif 1519 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 1520 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1521 uint16_t options_size = l2cap_setup_options_response(channel, config_options); 1522 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); 1523 } else { 1524 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_SUCCESS, 0, NULL); 1525 } 1526 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1527 } 1528 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 1529 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1530 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 1531 channel->local_sig_id = l2cap_next_sig_id(); 1532 uint16_t options_size = l2cap_setup_options_request(channel, config_options); 1533 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, options_size, &config_options); 1534 l2cap_start_rtx(channel); 1535 } 1536 if (l2cap_channel_ready_for_open(channel)){ 1537 channel->state = L2CAP_STATE_OPEN; 1538 l2cap_emit_channel_opened(channel, 0); // success 1539 } 1540 break; 1541 1542 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 1543 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1544 channel->state = L2CAP_STATE_INVALID; 1545 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 1546 // 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 :) 1547 l2cap_finialize_channel_close(channel); // -- remove from list 1548 channel = NULL; 1549 break; 1550 1551 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1552 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1553 channel->local_sig_id = l2cap_next_sig_id(); 1554 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 1555 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 1556 break; 1557 default: 1558 break; 1559 } 1560 1561 1562 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1563 1564 // handle channel finalize on L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE 1565 if (!channel) continue; 1566 1567 // ERTM mode 1568 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1569 1570 // check if we can still send 1571 if (channel->con_handle == HCI_CON_HANDLE_INVALID) continue; 1572 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1573 1574 // send if we have more data and remote windows isn't full yet 1575 log_debug("unacked_frames %u < min( stored frames %u, remote tx window size %u)?", channel->unacked_frames, channel->num_stored_tx_frames, channel->remote_tx_window_size); 1576 if (channel->unacked_frames < btstack_min(channel->num_stored_tx_frames, channel->remote_tx_window_size)){ 1577 channel->unacked_frames++; 1578 int index = channel->tx_send_index; 1579 channel->tx_send_index++; 1580 if (channel->tx_send_index >= channel->num_tx_buffers){ 1581 channel->tx_send_index = 0; 1582 } 1583 l2cap_ertm_send_information_frame(channel, index, 0); // final = 0 1584 continue; 1585 } 1586 1587 if (channel->send_supervisor_frame_receiver_ready){ 1588 channel->send_supervisor_frame_receiver_ready = 0; 1589 log_info("Send S-Frame: RR %u, final %u", channel->req_seq, channel->set_final_bit_after_packet_with_poll_bit_set); 1590 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); 1591 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1592 l2cap_ertm_send_supervisor_frame(channel, control); 1593 continue; 1594 } 1595 if (channel->send_supervisor_frame_receiver_ready_poll){ 1596 channel->send_supervisor_frame_receiver_ready_poll = 0; 1597 log_info("Send S-Frame: RR %u with poll=1 ", channel->req_seq); 1598 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY, 1, 0, channel->req_seq); 1599 l2cap_ertm_send_supervisor_frame(channel, control); 1600 continue; 1601 } 1602 if (channel->send_supervisor_frame_receiver_not_ready){ 1603 channel->send_supervisor_frame_receiver_not_ready = 0; 1604 log_info("Send S-Frame: RNR %u", channel->req_seq); 1605 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY, 0, 0, channel->req_seq); 1606 l2cap_ertm_send_supervisor_frame(channel, control); 1607 continue; 1608 } 1609 if (channel->send_supervisor_frame_reject){ 1610 channel->send_supervisor_frame_reject = 0; 1611 log_info("Send S-Frame: REJ %u", channel->req_seq); 1612 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT, 0, 0, channel->req_seq); 1613 l2cap_ertm_send_supervisor_frame(channel, control); 1614 continue; 1615 } 1616 if (channel->send_supervisor_frame_selective_reject){ 1617 channel->send_supervisor_frame_selective_reject = 0; 1618 log_info("Send S-Frame: SREJ %u", channel->expected_tx_seq); 1619 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); 1620 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1621 l2cap_ertm_send_supervisor_frame(channel, control); 1622 continue; 1623 } 1624 1625 if (channel->srej_active){ 1626 int i; 1627 for (i=0;i<channel->num_tx_buffers;i++){ 1628 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[i]; 1629 if (tx_state->retransmission_requested) { 1630 tx_state->retransmission_requested = 0; 1631 uint8_t final = channel->set_final_bit_after_packet_with_poll_bit_set; 1632 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1633 l2cap_ertm_send_information_frame(channel, i, final); 1634 break; 1635 } 1636 } 1637 if (i == channel->num_tx_buffers){ 1638 // no retransmission request found 1639 channel->srej_active = 0; 1640 } else { 1641 // packet was sent 1642 continue; 1643 } 1644 } 1645 } 1646 #endif 1647 1648 } 1649 #endif 1650 1651 #ifdef ENABLE_LE_DATA_CHANNELS 1652 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1653 while (btstack_linked_list_iterator_has_next(&it)){ 1654 uint8_t * acl_buffer; 1655 uint8_t * l2cap_payload; 1656 uint16_t pos; 1657 uint16_t payload_size; 1658 uint16_t mps; 1659 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1660 1661 if (channel->channel_type != L2CAP_CHANNEL_TYPE_LE_DATA_CHANNEL) continue; 1662 1663 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 1664 switch (channel->state){ 1665 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 1666 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1667 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 1668 // le psm, source cid, mtu, mps, initial credits 1669 channel->local_sig_id = l2cap_next_sig_id(); 1670 channel->credits_incoming = channel->new_credits_incoming; 1671 channel->new_credits_incoming = 0; 1672 mps = btstack_min(l2cap_max_le_mtu(), channel->local_mtu); 1673 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); 1674 break; 1675 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 1676 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1677 // TODO: support larger MPS 1678 channel->state = L2CAP_STATE_OPEN; 1679 channel->credits_incoming = channel->new_credits_incoming; 1680 channel->new_credits_incoming = 0; 1681 mps = btstack_min(l2cap_max_le_mtu(), channel->local_mtu); 1682 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); 1683 // notify client 1684 l2cap_emit_le_channel_opened(channel, 0); 1685 break; 1686 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 1687 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1688 channel->state = L2CAP_STATE_INVALID; 1689 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); 1690 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 1691 btstack_linked_list_iterator_remove(&it); 1692 l2cap_free_channel_entry(channel); 1693 break; 1694 case L2CAP_STATE_OPEN: 1695 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1696 1697 // send credits 1698 if (channel->new_credits_incoming){ 1699 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 1700 channel->local_sig_id = l2cap_next_sig_id(); 1701 uint16_t new_credits = channel->new_credits_incoming; 1702 channel->new_credits_incoming = 0; 1703 channel->credits_incoming += new_credits; 1704 l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); 1705 break; 1706 } 1707 1708 // send data 1709 if (!channel->send_sdu_buffer) break; 1710 if (!channel->credits_outgoing) break; 1711 1712 // send part of SDU 1713 hci_reserve_packet_buffer(); 1714 acl_buffer = hci_get_outgoing_packet_buffer(); 1715 l2cap_payload = acl_buffer + 8; 1716 pos = 0; 1717 if (!channel->send_sdu_pos){ 1718 // store SDU len 1719 channel->send_sdu_pos += 2; 1720 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 1721 pos += 2; 1722 } 1723 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 1724 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); 1725 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 1726 pos += payload_size; 1727 channel->send_sdu_pos += payload_size; 1728 l2cap_setup_header(acl_buffer, channel->con_handle, 0, channel->remote_cid, pos); 1729 // done 1730 1731 channel->credits_outgoing--; 1732 1733 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 1734 channel->send_sdu_buffer = NULL; 1735 // send done event 1736 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_PACKET_SENT); 1737 // inform about can send now 1738 l2cap_le_notify_channel_can_send(channel); 1739 } 1740 hci_send_acl_packet_buffer(8 + pos); 1741 break; 1742 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1743 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1744 channel->local_sig_id = l2cap_next_sig_id(); 1745 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 1746 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 1747 break; 1748 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 1749 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1750 channel->state = L2CAP_STATE_INVALID; 1751 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 1752 l2cap_le_finialize_channel_close(channel); // -- remove from list 1753 break; 1754 default: 1755 break; 1756 } 1757 } 1758 #endif 1759 1760 #ifdef ENABLE_BLE 1761 // send l2cap con paramter update if necessary 1762 hci_connections_get_iterator(&it); 1763 while(btstack_linked_list_iterator_has_next(&it)){ 1764 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1765 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 1766 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 1767 switch (connection->le_con_parameter_update_state){ 1768 case CON_PARAMETER_UPDATE_SEND_REQUEST: 1769 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 1770 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, l2cap_next_sig_id(), 1771 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 1772 break; 1773 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 1774 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 1775 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 1776 break; 1777 case CON_PARAMETER_UPDATE_DENY: 1778 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 1779 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 1780 break; 1781 default: 1782 break; 1783 } 1784 } 1785 #endif 1786 1787 // log_info("l2cap_run: exit"); 1788 } 1789 1790 #ifdef ENABLE_CLASSIC 1791 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 1792 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 1793 log_info("connection complete con_handle %04x - for channel %p cid 0x%04x", (int) con_handle, channel, channel->local_cid); 1794 // success, start l2cap handshake 1795 channel->con_handle = con_handle; 1796 // check remote SSP feature first 1797 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 1798 } 1799 } 1800 1801 static void l2cap_ready_to_connect(l2cap_channel_t * channel){ 1802 1803 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1804 // assumption: outgoing connection 1805 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1806 if (connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_IDLE){ 1807 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 1808 channel->state = L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES; 1809 return; 1810 } 1811 #endif 1812 1813 // fine, go ahead 1814 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1815 } 1816 1817 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 1818 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 1819 1820 // we have been waiting for remote supported features, if both support SSP, 1821 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)); 1822 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 1823 // request security level 2 1824 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 1825 channel->required_security_level = LEVEL_2; 1826 gap_request_security_level(channel->con_handle, LEVEL_2); 1827 return; 1828 } 1829 1830 l2cap_ready_to_connect(channel); 1831 } 1832 #endif 1833 1834 #ifdef L2CAP_USES_CHANNELS 1835 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, 1836 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 1837 1838 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 1839 if (!channel) { 1840 return NULL; 1841 } 1842 1843 // fill in 1844 channel->packet_handler = packet_handler; 1845 channel->channel_type = channel_type; 1846 bd_addr_copy(channel->address, address); 1847 channel->address_type = address_type; 1848 channel->psm = psm; 1849 channel->local_mtu = local_mtu; 1850 channel->remote_mtu = L2CAP_DEFAULT_MTU; 1851 channel->required_security_level = security_level; 1852 1853 // 1854 channel->local_cid = l2cap_next_local_cid(); 1855 channel->con_handle = HCI_CON_HANDLE_INVALID; 1856 1857 // set initial state 1858 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 1859 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 1860 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 1861 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 1862 1863 log_info("create channel %p, local_cid 0x%04x", channel, channel->local_cid); 1864 1865 return channel; 1866 } 1867 1868 static void l2cap_free_channel_entry(l2cap_channel_t * channel){ 1869 log_info("free channel %p, local_cid 0x%04x", channel, channel->local_cid); 1870 // assert rts/ertx timers are stopped 1871 l2cap_stop_rtx(channel); 1872 // free memory 1873 btstack_memory_l2cap_channel_free(channel); 1874 } 1875 #endif 1876 1877 #ifdef ENABLE_CLASSIC 1878 1879 /** 1880 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 1881 * @param packet_handler 1882 * @param address 1883 * @param psm 1884 * @param mtu 1885 * @param local_cid 1886 */ 1887 1888 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){ 1889 // limit MTU to the size of our outtgoing HCI buffer 1890 uint16_t local_mtu = btstack_min(mtu, l2cap_max_mtu()); 1891 1892 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u -> local mtu %u", bd_addr_to_str(address), psm, mtu, local_mtu); 1893 1894 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); 1895 if (!channel) { 1896 return BTSTACK_MEMORY_ALLOC_FAILED; 1897 } 1898 1899 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1900 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1901 #endif 1902 1903 // add to connections list 1904 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1905 1906 // store local_cid 1907 if (out_local_cid){ 1908 *out_local_cid = channel->local_cid; 1909 } 1910 1911 // check if hci connection is already usable 1912 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 1913 if (conn){ 1914 log_info("l2cap_create_channel, hci connection 0x%04x already exists", conn->con_handle); 1915 l2cap_handle_connection_complete(conn->con_handle, channel); 1916 // check if remote supported fearures are already received 1917 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 1918 l2cap_handle_remote_supported_features_received(channel); 1919 } 1920 } 1921 1922 l2cap_run(); 1923 1924 return 0; 1925 } 1926 1927 void l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 1928 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 1929 // find channel for local_cid 1930 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1931 if (channel) { 1932 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1933 } 1934 // process 1935 l2cap_run(); 1936 } 1937 1938 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 1939 // mark all channels before emitting open events as these could trigger new connetion requests to the same device 1940 btstack_linked_list_iterator_t it; 1941 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1942 while (btstack_linked_list_iterator_has_next(&it)){ 1943 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1944 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 1945 if (bd_addr_cmp( channel->address, address) != 0) continue; 1946 // channel for this address found 1947 switch (channel->state){ 1948 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1949 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1950 channel->state = L2CAP_STATE_EMIT_OPEN_FAILED_AND_DISCARD; 1951 break; 1952 default: 1953 break; 1954 } 1955 } 1956 // emit and free marked entries. restart loop to deal with list changes 1957 int done = 0; 1958 while (!done) { 1959 done = 1; 1960 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1961 while (btstack_linked_list_iterator_has_next(&it)){ 1962 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1963 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 1964 if (channel->state == L2CAP_STATE_EMIT_OPEN_FAILED_AND_DISCARD){ 1965 done = 0; 1966 // failure, forward error code 1967 l2cap_handle_channel_open_failed(channel, status); 1968 // discard channel 1969 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1970 l2cap_free_channel_entry(channel); 1971 break; 1972 } 1973 } 1974 } 1975 1976 } 1977 1978 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1979 btstack_linked_list_iterator_t it; 1980 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1981 while (btstack_linked_list_iterator_has_next(&it)){ 1982 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1983 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 1984 if ( ! bd_addr_cmp( channel->address, address) ){ 1985 l2cap_handle_connection_complete(handle, channel); 1986 } 1987 } 1988 // process 1989 l2cap_run(); 1990 } 1991 #endif 1992 1993 static void l2cap_notify_channel_can_send(void){ 1994 int done = 0; 1995 while (!done){ 1996 done = 1; 1997 btstack_linked_list_iterator_t it; 1998 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1999 while (btstack_linked_list_iterator_has_next(&it)){ 2000 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2001 if (!channel->waiting_for_can_send_now) continue; 2002 int can_send = 0; 2003 if (l2cap_is_le_channel_type(channel->channel_type)){ 2004 #ifdef ENABLE_BLE 2005 can_send = hci_can_send_acl_le_packet_now(); 2006 #endif 2007 } else { 2008 #ifdef ENABLE_CLASSIC 2009 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2010 // skip ertm channels as they only depend on free buffers in storage 2011 if (channel->mode == L2CAP_CHANNEL_MODE_BASIC){ 2012 can_send = hci_can_send_acl_classic_packet_now(); 2013 } 2014 #else 2015 can_send = hci_can_send_acl_classic_packet_now(); 2016 #endif /* ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE */ 2017 #endif /* ENABLE_CLASSIC */ 2018 } 2019 if (!can_send) continue; 2020 // requeue for fairness 2021 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2022 btstack_linked_list_add_tail(&l2cap_channels, (btstack_linked_item_t *) channel); 2023 // emit can send 2024 channel->waiting_for_can_send_now = 0; 2025 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 2026 // exit inner loop as we just broke the iterator, but try again 2027 done = 0; 2028 break; 2029 } 2030 } 2031 } 2032 2033 #ifdef L2CAP_USES_CHANNELS 2034 2035 static int l2cap_send_open_failed_on_hci_disconnect(l2cap_channel_t * channel){ 2036 // open cannot fail for for incoming connections 2037 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING) return 0; 2038 2039 // check state 2040 switch (channel->state){ 2041 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 2042 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 2043 case L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES: 2044 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 2045 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 2046 case L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES: 2047 case L2CAP_STATE_WAIT_CONNECT_RSP: 2048 case L2CAP_STATE_CONFIG: 2049 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 2050 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 2051 case L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE: 2052 case L2CAP_STATE_EMIT_OPEN_FAILED_AND_DISCARD: 2053 return 1; 2054 2055 case L2CAP_STATE_OPEN: 2056 case L2CAP_STATE_CLOSED: 2057 case L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES: 2058 case L2CAP_STATE_WAIT_DISCONNECT: 2059 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_INSUFFICIENT_SECURITY: 2060 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 2061 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 2062 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 2063 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 2064 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 2065 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 2066 case L2CAP_STATE_INVALID: 2067 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 2068 return 0; 2069 // no default here, to get a warning about new states 2070 } 2071 // still, the compiler insists on a return value 2072 return 0; 2073 } 2074 #endif 2075 2076 #ifdef ENABLE_CLASSIC 2077 static void l2cap_handle_hci_disconnect_event(l2cap_channel_t * channel){ 2078 if (l2cap_send_open_failed_on_hci_disconnect(channel)){ 2079 l2cap_handle_channel_open_failed(channel, L2CAP_CONNECTION_BASEBAND_DISCONNECT); 2080 } else { 2081 l2cap_handle_channel_closed(channel); 2082 } 2083 l2cap_free_channel_entry(channel); 2084 } 2085 #endif 2086 2087 #ifdef ENABLE_LE_DATA_CHANNELS 2088 static void l2cap_handle_hci_le_disconnect_event(l2cap_channel_t * channel){ 2089 if (l2cap_send_open_failed_on_hci_disconnect(channel)){ 2090 l2cap_emit_le_channel_opened(channel, L2CAP_CONNECTION_BASEBAND_DISCONNECT); 2091 } else { 2092 l2cap_emit_le_channel_closed(channel); 2093 } 2094 l2cap_free_channel_entry(channel); 2095 } 2096 #endif 2097 2098 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 2099 2100 UNUSED(packet_type); // ok: registered with hci_event_callback_registration 2101 UNUSED(cid); // ok: there is no channel 2102 UNUSED(size); // ok: fixed format events read from HCI buffer 2103 2104 #ifdef ENABLE_CLASSIC 2105 bd_addr_t address; 2106 int hci_con_used; 2107 #endif 2108 #ifdef L2CAP_USES_CHANNELS 2109 hci_con_handle_t handle; 2110 btstack_linked_list_iterator_t it; 2111 #endif 2112 2113 switch(hci_event_packet_get_type(packet)){ 2114 2115 // Notify channel packet handler if they can send now 2116 case HCI_EVENT_TRANSPORT_PACKET_SENT: 2117 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 2118 case BTSTACK_EVENT_NR_CONNECTIONS_CHANGED: 2119 l2cap_run(); // try sending signaling packets first 2120 l2cap_notify_channel_can_send(); 2121 break; 2122 2123 case HCI_EVENT_COMMAND_STATUS: 2124 #ifdef ENABLE_CLASSIC 2125 // check command status for create connection for errors 2126 if (HCI_EVENT_IS_COMMAND_STATUS(packet, hci_create_connection)){ 2127 // cache outgoing address and reset 2128 memcpy(address, l2cap_outgoing_classic_addr, 6); 2129 memset(l2cap_outgoing_classic_addr, 0, 6); 2130 // error => outgoing connection failed 2131 uint8_t status = hci_event_command_status_get_status(packet); 2132 if (status){ 2133 l2cap_handle_connection_failed_for_addr(address, status); 2134 } 2135 } 2136 #endif 2137 l2cap_run(); // try sending signaling packets first 2138 break; 2139 2140 #ifdef ENABLE_CLASSIC 2141 // handle connection complete events 2142 case HCI_EVENT_CONNECTION_COMPLETE: 2143 reverse_bd_addr(&packet[5], address); 2144 if (packet[2] == 0){ 2145 handle = little_endian_read_16(packet, 3); 2146 l2cap_handle_connection_success_for_addr(address, handle); 2147 } else { 2148 l2cap_handle_connection_failed_for_addr(address, packet[2]); 2149 } 2150 break; 2151 2152 // handle successful create connection cancel command 2153 case HCI_EVENT_COMMAND_COMPLETE: 2154 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 2155 if (packet[5] == 0){ 2156 reverse_bd_addr(&packet[6], address); 2157 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 2158 l2cap_handle_connection_failed_for_addr(address, 0x16); 2159 } 2160 } 2161 l2cap_run(); // try sending signaling packets first 2162 break; 2163 #endif 2164 2165 #ifdef L2CAP_USES_CHANNELS 2166 // handle disconnection complete events 2167 case HCI_EVENT_DISCONNECTION_COMPLETE: 2168 handle = little_endian_read_16(packet, 3); 2169 // send l2cap open failed or closed events for all channels on this handle and free them 2170 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2171 while (btstack_linked_list_iterator_has_next(&it)){ 2172 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2173 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 2174 if (channel->con_handle != handle) continue; 2175 btstack_linked_list_iterator_remove(&it); 2176 switch(channel->channel_type){ 2177 #ifdef ENABLE_CLASSIC 2178 case L2CAP_CHANNEL_TYPE_CLASSIC: 2179 l2cap_handle_hci_disconnect_event(channel); 2180 break; 2181 #endif 2182 #ifdef ENABLE_LE_DATA_CHANNELS 2183 case L2CAP_CHANNEL_TYPE_LE_DATA_CHANNEL: 2184 l2cap_handle_hci_le_disconnect_event(channel); 2185 break; 2186 #endif 2187 default: 2188 break; 2189 } 2190 } 2191 break; 2192 #endif 2193 2194 2195 // HCI Connection Timeouts 2196 #ifdef ENABLE_CLASSIC 2197 case L2CAP_EVENT_TIMEOUT_CHECK: 2198 handle = little_endian_read_16(packet, 2); 2199 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 2200 if (hci_authentication_active_for_handle(handle)) break; 2201 hci_con_used = 0; 2202 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2203 while (btstack_linked_list_iterator_has_next(&it)){ 2204 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2205 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 2206 if (channel->con_handle != handle) continue; 2207 hci_con_used = 1; 2208 break; 2209 } 2210 if (hci_con_used) break; 2211 if (!hci_can_send_command_packet_now()) break; 2212 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 2213 break; 2214 2215 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 2216 handle = little_endian_read_16(packet, 3); 2217 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2218 while (btstack_linked_list_iterator_has_next(&it)){ 2219 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2220 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 2221 if (channel->con_handle != handle) continue; 2222 log_info("remote supported features, channel %p, cid %04x - state %u", channel, channel->local_cid, channel->state); 2223 l2cap_handle_remote_supported_features_received(channel); 2224 } 2225 break; 2226 2227 case GAP_EVENT_SECURITY_LEVEL: 2228 handle = little_endian_read_16(packet, 2); 2229 log_info("l2cap - security level update for handle 0x%04x", handle); 2230 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2231 while (btstack_linked_list_iterator_has_next(&it)){ 2232 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2233 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 2234 if (channel->con_handle != handle) continue; 2235 2236 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 2237 gap_security_level_t required_level = channel->required_security_level; 2238 2239 log_info("channel %p, cid %04x - state %u: actual %u >= required %u?", channel, channel->local_cid, channel->state, actual_level, required_level); 2240 2241 switch (channel->state){ 2242 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 2243 if (actual_level >= required_level){ 2244 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2245 // we need to know if ERTM is supported before sending a config response 2246 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 2247 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 2248 channel->state = L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES; 2249 #else 2250 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2251 l2cap_emit_incoming_connection(channel); 2252 #endif 2253 } else { 2254 channel->reason = 0x0003; // security block 2255 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 2256 } 2257 break; 2258 2259 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 2260 if (actual_level >= required_level){ 2261 l2cap_ready_to_connect(channel); 2262 } else { 2263 // disconnnect, authentication not good enough 2264 hci_disconnect_security_block(handle); 2265 } 2266 break; 2267 2268 default: 2269 break; 2270 } 2271 } 2272 break; 2273 #endif 2274 2275 default: 2276 break; 2277 } 2278 2279 l2cap_run(); 2280 } 2281 2282 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t cid, uint16_t data){ 2283 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 2284 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 2285 signaling_responses[signaling_responses_pending].handle = handle; 2286 signaling_responses[signaling_responses_pending].code = code; 2287 signaling_responses[signaling_responses_pending].sig_id = sig_id; 2288 signaling_responses[signaling_responses_pending].cid = cid; 2289 signaling_responses[signaling_responses_pending].data = data; 2290 signaling_responses_pending++; 2291 l2cap_run(); 2292 } 2293 } 2294 2295 #ifdef ENABLE_CLASSIC 2296 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 2297 channel->remote_sig_id = identifier; 2298 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 2299 l2cap_run(); 2300 } 2301 2302 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 2303 2304 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 2305 l2cap_service_t *service = l2cap_get_service(psm); 2306 if (!service) { 2307 // 0x0002 PSM not supported 2308 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 2309 return; 2310 } 2311 2312 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 2313 if (!hci_connection) { 2314 // 2315 log_error("no hci_connection for handle %u", handle); 2316 return; 2317 } 2318 2319 // alloc structure 2320 // log_info("l2cap_handle_connection_request register channel"); 2321 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, L2CAP_CHANNEL_TYPE_CLASSIC, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 2322 psm, service->mtu, service->required_security_level); 2323 if (!channel){ 2324 // 0x0004 No resources available 2325 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 2326 return; 2327 } 2328 2329 channel->con_handle = handle; 2330 channel->remote_cid = source_cid; 2331 channel->remote_sig_id = sig_id; 2332 2333 // limit local mtu to max acl packet length - l2cap header 2334 if (channel->local_mtu > l2cap_max_mtu()) { 2335 channel->local_mtu = l2cap_max_mtu(); 2336 } 2337 2338 // set initial state 2339 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 2340 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND | L2CAP_CHANNEL_STATE_VAR_INCOMING); 2341 2342 // add to connections list 2343 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 2344 2345 // assert security requirements 2346 gap_request_security_level(handle, channel->required_security_level); 2347 } 2348 2349 void l2cap_accept_connection(uint16_t local_cid){ 2350 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 2351 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 2352 if (!channel) { 2353 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 2354 return; 2355 } 2356 2357 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2358 // configure L2CAP Basic mode 2359 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2360 #endif 2361 2362 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 2363 2364 // process 2365 l2cap_run(); 2366 } 2367 2368 void l2cap_decline_connection(uint16_t local_cid){ 2369 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 2370 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 2371 if (!channel) { 2372 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 2373 return; 2374 } 2375 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 2376 channel->reason = 0x04; // no resources available 2377 l2cap_run(); 2378 } 2379 2380 // @pre command len is valid, see check in l2cap_signaling_handler_channel 2381 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 2382 2383 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2384 uint8_t use_fcs = 1; 2385 #endif 2386 2387 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2388 2389 uint16_t flags = little_endian_read_16(command, 6); 2390 if (flags & 1) { 2391 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 2392 } 2393 2394 // accept the other's configuration options 2395 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2396 uint16_t pos = 8; 2397 while (pos < end_pos){ 2398 uint8_t option_hint = command[pos] >> 7; 2399 uint8_t option_type = command[pos] & 0x7f; 2400 // log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 2401 pos++; 2402 uint8_t length = command[pos++]; 2403 // MTU { type(8): 1, len(8):2, MTU(16) } 2404 if (option_type == L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT && length == 2){ 2405 channel->remote_mtu = little_endian_read_16(command, pos); 2406 log_info("Remote MTU %u", channel->remote_mtu); 2407 if (channel->remote_mtu > l2cap_max_mtu()){ 2408 log_info("Remote MTU %u larger than outgoing buffer, only using MTU = %u", channel->remote_mtu, l2cap_max_mtu()); 2409 channel->remote_mtu = l2cap_max_mtu(); 2410 } 2411 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 2412 } 2413 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 2414 if (option_type == L2CAP_CONFIG_OPTION_TYPE_FLUSH_TIMEOUT && length == 2){ 2415 channel->flush_timeout = little_endian_read_16(command, pos); 2416 log_info("Flush timeout: %u ms", channel->flush_timeout); 2417 } 2418 2419 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2420 // Retransmission and Flow Control Option 2421 if (option_type == L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL && length == 9){ 2422 l2cap_channel_mode_t mode = (l2cap_channel_mode_t) command[pos]; 2423 switch(channel->mode){ 2424 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 2425 // Store remote config 2426 channel->remote_tx_window_size = command[pos+1]; 2427 channel->remote_max_transmit = command[pos+2]; 2428 channel->remote_retransmission_timeout_ms = little_endian_read_16(command, pos + 3); 2429 channel->remote_monitor_timeout_ms = little_endian_read_16(command, pos + 5); 2430 channel->remote_mps = little_endian_read_16(command, pos + 7); 2431 log_info("FC&C config: tx window: %u, max transmit %u, retrans timeout %u, monitor timeout %u, mps %u", 2432 channel->remote_tx_window_size, 2433 channel->remote_max_transmit, 2434 channel->remote_retransmission_timeout_ms, 2435 channel->remote_monitor_timeout_ms, 2436 channel->remote_mps); 2437 // If ERTM mandatory, but remote doens't offer ERTM -> disconnect 2438 if (channel->ertm_mandatory && mode != L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 2439 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2440 } else { 2441 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 2442 } 2443 break; 2444 case L2CAP_CHANNEL_MODE_BASIC: 2445 switch (mode){ 2446 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 2447 // remote asks for ERTM, but we want basic mode. disconnect if this happens a second time 2448 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED){ 2449 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2450 } 2451 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED); 2452 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 2453 break; 2454 default: // case L2CAP_CHANNEL_MODE_BASIC: 2455 // TODO store and evaluate configuration 2456 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 2457 break; 2458 } 2459 break; 2460 default: 2461 break; 2462 } 2463 } 2464 if (option_type == L2CAP_CONFIG_OPTION_TYPE_FRAME_CHECK_SEQUENCE && length == 1){ 2465 use_fcs = command[pos]; 2466 } 2467 #endif 2468 // check for unknown options 2469 if (option_hint == 0 && (option_type < L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT || option_type > L2CAP_CONFIG_OPTION_TYPE_EXTENDED_WINDOW_SIZE)){ 2470 log_info("l2cap cid %u, unknown options", channel->local_cid); 2471 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 2472 } 2473 pos += length; 2474 } 2475 2476 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2477 // "FCS" has precedence over "No FCS" 2478 uint8_t update = channel->fcs_option || use_fcs; 2479 log_info("local fcs: %u, remote fcs: %u -> %u", channel->fcs_option, use_fcs, update); 2480 channel->fcs_option = update; 2481 #endif 2482 } 2483 2484 // @pre command len is valid, see check in l2cap_signaling_handler_channel 2485 static void l2cap_signaling_handle_configure_response(l2cap_channel_t *channel, uint8_t result, uint8_t *command){ 2486 log_info("l2cap_signaling_handle_configure_response"); 2487 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2488 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2489 uint16_t pos = 10; 2490 while (pos < end_pos){ 2491 uint8_t option_hint = command[pos] >> 7; 2492 uint8_t option_type = command[pos] & 0x7f; 2493 // log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 2494 pos++; 2495 uint8_t length = command[pos++]; 2496 2497 // Retransmission and Flow Control Option 2498 if (option_type == L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL && length == 9){ 2499 switch (channel->mode){ 2500 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 2501 if (channel->ertm_mandatory){ 2502 // ?? 2503 } else { 2504 // On 'Reject - Unacceptable Parameters' to our optional ERTM request, fall back to BASIC mode 2505 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 2506 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_ERTM_BUFFER_RELEASED); 2507 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2508 } 2509 } 2510 break; 2511 case L2CAP_CHANNEL_MODE_BASIC: 2512 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 2513 // On 'Reject - Unacceptable Parameters' to our Basic mode request, disconnect 2514 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2515 } 2516 break; 2517 default: 2518 break; 2519 } 2520 } 2521 2522 // check for unknown options 2523 if (option_hint == 0 && (option_type < L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT || option_type > L2CAP_CONFIG_OPTION_TYPE_EXTENDED_WINDOW_SIZE)){ 2524 log_info("l2cap cid %u, unknown options", channel->local_cid); 2525 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 2526 } 2527 2528 pos += length; 2529 } 2530 #else 2531 UNUSED(channel); // ok: no code 2532 UNUSED(result); // ok: no code 2533 UNUSED(command); // ok: no code 2534 #endif 2535 } 2536 2537 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 2538 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 2539 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 2540 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 2541 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 2542 if (channel->state == L2CAP_STATE_OPEN) return 0; 2543 return 1; 2544 } 2545 2546 2547 // @pre command len is valid, see check in l2cap_signaling_handler_dispatch 2548 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 2549 2550 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2551 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2552 uint16_t cmd_len = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2553 uint16_t result = 0; 2554 2555 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 2556 2557 // handle DISCONNECT REQUESTS seperately 2558 if (code == DISCONNECTION_REQUEST){ 2559 switch (channel->state){ 2560 case L2CAP_STATE_CONFIG: 2561 case L2CAP_STATE_OPEN: 2562 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 2563 case L2CAP_STATE_WAIT_DISCONNECT: 2564 l2cap_handle_disconnect_request(channel, identifier); 2565 break; 2566 2567 default: 2568 // ignore in other states 2569 break; 2570 } 2571 return; 2572 } 2573 2574 // @STATEMACHINE(l2cap) 2575 switch (channel->state) { 2576 2577 case L2CAP_STATE_WAIT_CONNECT_RSP: 2578 switch (code){ 2579 case CONNECTION_RESPONSE: 2580 if (cmd_len < 8){ 2581 // command imcomplete 2582 l2cap_register_signaling_response(channel->con_handle, COMMAND_REJECT, identifier, 0, L2CAP_REJ_CMD_UNKNOWN); 2583 break; 2584 } 2585 l2cap_stop_rtx(channel); 2586 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2587 switch (result) { 2588 case 0: 2589 // successful connection 2590 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2591 channel->state = L2CAP_STATE_CONFIG; 2592 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 2593 break; 2594 case 1: 2595 // connection pending. get some coffee, but start the ERTX 2596 l2cap_start_ertx(channel); 2597 break; 2598 default: 2599 // channel closed 2600 channel->state = L2CAP_STATE_CLOSED; 2601 // map l2cap connection response result to BTstack status enumeration 2602 l2cap_handle_channel_open_failed(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 2603 2604 // drop link key if security block 2605 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 2606 gap_drop_link_key_for_bd_addr(channel->address); 2607 } 2608 2609 // discard channel 2610 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2611 l2cap_free_channel_entry(channel); 2612 break; 2613 } 2614 break; 2615 2616 default: 2617 //@TODO: implement other signaling packets 2618 break; 2619 } 2620 break; 2621 2622 case L2CAP_STATE_CONFIG: 2623 switch (code) { 2624 case CONFIGURE_REQUEST: 2625 if (cmd_len < 4){ 2626 // command incomplete 2627 l2cap_register_signaling_response(channel->con_handle, COMMAND_REJECT, identifier, 0, L2CAP_REJ_CMD_UNKNOWN); 2628 break; 2629 } 2630 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 2631 l2cap_signaling_handle_configure_request(channel, command); 2632 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 2633 // only done if continuation not set 2634 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 2635 } 2636 break; 2637 case CONFIGURE_RESPONSE: 2638 if (cmd_len < 6){ 2639 // command incomplete 2640 l2cap_register_signaling_response(channel->con_handle, COMMAND_REJECT, identifier, 0, L2CAP_REJ_CMD_UNKNOWN); 2641 break; 2642 } 2643 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2644 l2cap_stop_rtx(channel); 2645 l2cap_signaling_handle_configure_response(channel, result, command); 2646 switch (result){ 2647 case 0: // success 2648 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 2649 break; 2650 case 4: // pending 2651 l2cap_start_ertx(channel); 2652 break; 2653 default: 2654 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2655 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION && channel->ertm_mandatory){ 2656 // remote does not offer ertm but it's required 2657 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2658 break; 2659 } 2660 #endif 2661 // retry on negative result 2662 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 2663 break; 2664 } 2665 break; 2666 default: 2667 break; 2668 } 2669 if (l2cap_channel_ready_for_open(channel)){ 2670 // for open: 2671 channel->state = L2CAP_STATE_OPEN; 2672 l2cap_emit_channel_opened(channel, 0); 2673 } 2674 break; 2675 2676 case L2CAP_STATE_WAIT_DISCONNECT: 2677 switch (code) { 2678 case DISCONNECTION_RESPONSE: 2679 l2cap_finialize_channel_close(channel); 2680 break; 2681 default: 2682 //@TODO: implement other signaling packets 2683 break; 2684 } 2685 break; 2686 2687 case L2CAP_STATE_CLOSED: 2688 // @TODO handle incoming requests 2689 break; 2690 2691 case L2CAP_STATE_OPEN: 2692 //@TODO: implement other signaling packets, e.g. re-configure 2693 break; 2694 default: 2695 break; 2696 } 2697 // log_info("new state %u", channel->state); 2698 } 2699 2700 2701 // @pre command len is valid, see check in l2cap_acl_classic_handler 2702 static void l2cap_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command){ 2703 2704 btstack_linked_list_iterator_t it; 2705 2706 // get code, signalind identifier and command len 2707 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2708 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2709 uint16_t cmd_len = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2710 2711 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_RESPONSE 2712 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_RESPONSE){ 2713 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2714 return; 2715 } 2716 2717 // general commands without an assigned channel 2718 switch(code) { 2719 2720 case CONNECTION_REQUEST: 2721 if (cmd_len == 4){ 2722 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2723 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2724 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 2725 } else { 2726 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2727 } 2728 return; 2729 2730 case ECHO_REQUEST: 2731 l2cap_register_signaling_response(handle, code, sig_id, 0, 0); 2732 return; 2733 2734 case INFORMATION_REQUEST: 2735 if (cmd_len == 2) { 2736 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2737 l2cap_register_signaling_response(handle, code, sig_id, 0, info_type); 2738 } else { 2739 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2740 } 2741 return; 2742 2743 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2744 case INFORMATION_RESPONSE: { 2745 hci_connection_t * connection = hci_connection_for_handle(handle); 2746 if (!connection) return; 2747 if (cmd_len >= 4) { 2748 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2749 uint16_t result = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2750 if (result != 0) return; 2751 if (info_type != L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED) return; 2752 if (cmd_len >= 6) { 2753 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_DONE; 2754 connection->l2cap_state.extended_feature_mask = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2755 log_info("extended features mask 0x%02x", connection->l2cap_state.extended_feature_mask); 2756 // trigger connection request 2757 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2758 while (btstack_linked_list_iterator_has_next(&it)){ 2759 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2760 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 2761 if (channel->con_handle != handle) continue; 2762 // bail if ERTM was requested but is not supported 2763 if ((channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION) && ((connection->l2cap_state.extended_feature_mask & 0x08) == 0)){ 2764 if (channel->ertm_mandatory){ 2765 // channel closed 2766 channel->state = L2CAP_STATE_CLOSED; 2767 // map l2cap connection response result to BTstack status enumeration 2768 l2cap_handle_channel_open_failed(channel, L2CAP_CONNECTION_RESPONSE_RESULT_ERTM_NOT_SUPPORTED); 2769 // discard channel 2770 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2771 l2cap_free_channel_entry(channel); 2772 continue; 2773 } else { 2774 // fallback to Basic mode 2775 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_ERTM_BUFFER_RELEASED); 2776 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2777 } 2778 } 2779 // start connecting 2780 if (channel->state == L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES){ 2781 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 2782 } 2783 // respond to connection request 2784 if (channel->state == L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES){ 2785 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2786 l2cap_emit_incoming_connection(channel); 2787 } 2788 } 2789 return; // cmd len valid 2790 } 2791 } 2792 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2793 return; 2794 } 2795 #endif 2796 2797 default: 2798 break; 2799 } 2800 2801 // Get potential destination CID 2802 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2803 2804 // Find channel for this sig_id and connection handle 2805 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2806 while (btstack_linked_list_iterator_has_next(&it)){ 2807 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2808 if (!l2cap_is_dynamic_channel_type(channel->channel_type)) continue; 2809 if (channel->con_handle != handle) continue; 2810 if (code & 1) { 2811 // match odd commands (responses) by previous signaling identifier 2812 if (channel->local_sig_id == sig_id) { 2813 l2cap_signaling_handler_channel(channel, command); 2814 break; 2815 } 2816 } else { 2817 // match even commands (requests) by local channel id 2818 if (channel->local_cid == dest_cid) { 2819 l2cap_signaling_handler_channel(channel, command); 2820 break; 2821 } 2822 } 2823 } 2824 } 2825 #endif 2826 2827 #ifdef ENABLE_BLE 2828 2829 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 2830 uint8_t event[6]; 2831 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 2832 event[1] = 4; 2833 little_endian_store_16(event, 2, con_handle); 2834 little_endian_store_16(event, 4, result); 2835 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2836 if (!l2cap_event_packet_handler) return; 2837 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 2838 } 2839 2840 // @returns valid 2841 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 2842 hci_connection_t * connection; 2843 uint16_t result; 2844 uint8_t event[12]; 2845 2846 #ifdef ENABLE_LE_DATA_CHANNELS 2847 btstack_linked_list_iterator_t it; 2848 l2cap_channel_t * channel; 2849 uint16_t local_cid; 2850 uint16_t le_psm; 2851 uint16_t new_credits; 2852 uint16_t credits_before; 2853 l2cap_service_t * service; 2854 uint16_t source_cid; 2855 #endif 2856 2857 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2858 uint16_t len = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2859 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u, len %u", code, sig_id, len); 2860 2861 switch (code){ 2862 2863 case CONNECTION_PARAMETER_UPDATE_REQUEST: 2864 // check size 2865 if (len < 8) return 0; 2866 connection = hci_connection_for_handle(handle); 2867 if (connection){ 2868 if (connection->role != HCI_ROLE_MASTER){ 2869 // reject command without notifying upper layer when not in master role 2870 return 0; 2871 } 2872 le_connection_parameter_range_t existing_range; 2873 gap_get_connection_parameter_range(&existing_range); 2874 uint16_t le_conn_interval_min = little_endian_read_16(command,L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2875 uint16_t le_conn_interval_max = little_endian_read_16(command,L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2876 uint16_t le_conn_latency = little_endian_read_16(command,L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2877 uint16_t le_supervision_timeout = little_endian_read_16(command,L2CAP_SIGNALING_COMMAND_DATA_OFFSET+6); 2878 2879 int update_parameter = gap_connection_parameter_range_included(&existing_range, le_conn_interval_min, le_conn_interval_max, le_conn_latency, le_supervision_timeout); 2880 if (update_parameter){ 2881 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 2882 connection->le_conn_interval_min = le_conn_interval_min; 2883 connection->le_conn_interval_max = le_conn_interval_max; 2884 connection->le_conn_latency = le_conn_latency; 2885 connection->le_supervision_timeout = le_supervision_timeout; 2886 } else { 2887 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 2888 } 2889 connection->le_con_param_update_identifier = sig_id; 2890 } 2891 2892 if (!l2cap_event_packet_handler) break; 2893 2894 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 2895 event[1] = 8; 2896 little_endian_store_16(event, 2, handle); 2897 memcpy(&event[4], &command[4], 8); 2898 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2899 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2900 break; 2901 2902 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 2903 // check size 2904 if (len < 2) return 0; 2905 result = little_endian_read_16(command, 4); 2906 l2cap_emit_connection_parameter_update_response(handle, result); 2907 break; 2908 2909 #ifdef ENABLE_LE_DATA_CHANNELS 2910 2911 case COMMAND_REJECT: 2912 // Find channel for this sig_id and connection handle 2913 channel = NULL; 2914 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2915 while (btstack_linked_list_iterator_has_next(&it)){ 2916 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2917 if (!l2cap_is_dynamic_channel_type(a_channel->channel_type)) continue; 2918 if (a_channel->con_handle != handle) continue; 2919 if (a_channel->local_sig_id != sig_id) continue; 2920 channel = a_channel; 2921 break; 2922 } 2923 if (!channel) break; 2924 2925 // if received while waiting for le connection response, assume legacy device 2926 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 2927 channel->state = L2CAP_STATE_CLOSED; 2928 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 2929 l2cap_emit_le_channel_opened(channel, 0x0002); 2930 2931 // discard channel 2932 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2933 l2cap_free_channel_entry(channel); 2934 break; 2935 } 2936 break; 2937 2938 case LE_CREDIT_BASED_CONNECTION_REQUEST: 2939 // check size 2940 if (len < 10) return 0; 2941 2942 // get hci connection, bail if not found (must not happen) 2943 connection = hci_connection_for_handle(handle); 2944 if (!connection) return 0; 2945 2946 // check if service registered 2947 le_psm = little_endian_read_16(command, 4); 2948 service = l2cap_le_get_service(le_psm); 2949 source_cid = little_endian_read_16(command, 6); 2950 2951 if (service){ 2952 if (source_cid < 0x40){ 2953 // 0x0009 Connection refused - Invalid Source CID 2954 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0009); 2955 return 1; 2956 } 2957 2958 // go through list of channels for this ACL connection and check if we get a match 2959 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2960 while (btstack_linked_list_iterator_has_next(&it)){ 2961 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2962 if (!l2cap_is_dynamic_channel_type(a_channel->channel_type)) continue; 2963 if (a_channel->con_handle != handle) continue; 2964 if (a_channel->remote_cid != source_cid) continue; 2965 // 0x000a Connection refused - Source CID already allocated 2966 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x000a); 2967 return 1; 2968 } 2969 2970 // security: check encryption 2971 if (service->required_security_level >= LEVEL_2){ 2972 if (gap_encryption_key_size(handle) == 0){ 2973 // 0x0008 Connection refused - insufficient encryption 2974 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0008); 2975 return 1; 2976 } 2977 // anything less than 16 byte key size is insufficient 2978 if (gap_encryption_key_size(handle) < 16){ 2979 // 0x0007 Connection refused – insufficient encryption key size 2980 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0007); 2981 return 1; 2982 } 2983 } 2984 2985 // security: check authencation 2986 if (service->required_security_level >= LEVEL_3){ 2987 if (!gap_authenticated(handle)){ 2988 // 0x0005 Connection refused – insufficient authentication 2989 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0005); 2990 return 1; 2991 } 2992 } 2993 2994 // security: check authorization 2995 if (service->required_security_level >= LEVEL_4){ 2996 if (gap_authorization_state(handle) != AUTHORIZATION_GRANTED){ 2997 // 0x0006 Connection refused – insufficient authorization 2998 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0006); 2999 return 1; 3000 } 3001 } 3002 3003 // allocate channel 3004 channel = l2cap_create_channel_entry(service->packet_handler, L2CAP_CHANNEL_TYPE_LE_DATA_CHANNEL, connection->address, 3005 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 3006 if (!channel){ 3007 // 0x0004 Connection refused – no resources available 3008 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 3009 return 1; 3010 } 3011 3012 channel->con_handle = handle; 3013 channel->remote_cid = source_cid; 3014 channel->remote_sig_id = sig_id; 3015 channel->remote_mtu = little_endian_read_16(command, 8); 3016 channel->remote_mps = little_endian_read_16(command, 10); 3017 channel->credits_outgoing = little_endian_read_16(command, 12); 3018 3019 // set initial state 3020 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 3021 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 3022 3023 // add to connections list 3024 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 3025 3026 // post connection request event 3027 l2cap_emit_le_incoming_connection(channel); 3028 3029 } else { 3030 // Connection refused – LE_PSM not supported 3031 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 3032 } 3033 break; 3034 3035 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 3036 // check size 3037 if (len < 10) return 0; 3038 3039 // Find channel for this sig_id and connection handle 3040 channel = NULL; 3041 btstack_linked_list_iterator_init(&it, &l2cap_channels); 3042 while (btstack_linked_list_iterator_has_next(&it)){ 3043 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 3044 if (!l2cap_is_dynamic_channel_type(a_channel->channel_type)) continue; 3045 if (a_channel->con_handle != handle) continue; 3046 if (a_channel->local_sig_id != sig_id) continue; 3047 channel = a_channel; 3048 break; 3049 } 3050 if (!channel) break; 3051 3052 // cid + 0 3053 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 3054 if (result){ 3055 channel->state = L2CAP_STATE_CLOSED; 3056 // map l2cap connection response result to BTstack status enumeration 3057 l2cap_emit_le_channel_opened(channel, result); 3058 3059 // discard channel 3060 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 3061 l2cap_free_channel_entry(channel); 3062 break; 3063 } 3064 3065 // success 3066 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 3067 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 3068 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 3069 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 3070 channel->state = L2CAP_STATE_OPEN; 3071 l2cap_emit_le_channel_opened(channel, result); 3072 break; 3073 3074 case LE_FLOW_CONTROL_CREDIT: 3075 // check size 3076 if (len < 4) return 0; 3077 3078 // find channel 3079 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 3080 channel = l2cap_get_channel_for_local_cid(local_cid); 3081 if (!channel) { 3082 log_error("l2cap: no channel for cid 0x%02x", local_cid); 3083 break; 3084 } 3085 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 3086 credits_before = channel->credits_outgoing; 3087 channel->credits_outgoing += new_credits; 3088 // check for credit overrun 3089 if (credits_before > channel->credits_outgoing){ 3090 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 3091 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3092 break; 3093 } 3094 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 3095 break; 3096 3097 case DISCONNECTION_REQUEST: 3098 3099 // check size 3100 if (len < 4) return 0; 3101 3102 // find channel 3103 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 3104 channel = l2cap_get_channel_for_local_cid(local_cid); 3105 if (!channel) { 3106 log_error("l2cap: no channel for cid 0x%02x", local_cid); 3107 break; 3108 } 3109 channel->remote_sig_id = sig_id; 3110 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 3111 break; 3112 3113 #endif 3114 3115 case DISCONNECTION_RESPONSE: 3116 break; 3117 3118 default: 3119 // command unknown -> reject command 3120 return 0; 3121 } 3122 return 1; 3123 } 3124 #endif 3125 3126 static void l2cap_acl_classic_handler(hci_con_handle_t handle, uint8_t *packet, uint16_t size){ 3127 #ifdef ENABLE_CLASSIC 3128 l2cap_channel_t * l2cap_channel; 3129 l2cap_fixed_channel_t * l2cap_fixed_channel; 3130 3131 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 3132 switch (channel_id) { 3133 3134 case L2CAP_CID_SIGNALING: { 3135 uint32_t command_offset = 8; 3136 while ((command_offset + L2CAP_SIGNALING_COMMAND_DATA_OFFSET) < size) { 3137 // assert signaling command is fully inside packet 3138 uint16_t data_len = little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 3139 uint32_t next_command_offset = command_offset + L2CAP_SIGNALING_COMMAND_DATA_OFFSET + data_len; 3140 if (next_command_offset > size){ 3141 log_error("l2cap signaling command len invalid -> drop"); 3142 break; 3143 } 3144 // handle signaling command 3145 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 3146 // go to next command 3147 command_offset = next_command_offset; 3148 } 3149 break; 3150 } 3151 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 3152 l2cap_fixed_channel = l2cap_fixed_channel_for_channel_id(L2CAP_CID_CONNECTIONLESS_CHANNEL); 3153 if (!l2cap_fixed_channel) break; 3154 if (!l2cap_fixed_channel->packet_handler) break; 3155 (*l2cap_fixed_channel->packet_handler)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 3156 break; 3157 3158 default: 3159 // Find channel for this channel_id and connection handle 3160 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 3161 if (l2cap_channel) { 3162 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 3163 if (l2cap_channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 3164 3165 int fcs_size = l2cap_channel->fcs_option ? 2 : 0; 3166 3167 // assert control + FCS fields are inside 3168 if (size < COMPLETE_L2CAP_HEADER+2+fcs_size) break; 3169 3170 if (l2cap_channel->fcs_option){ 3171 // verify FCS (required if one side requested it) 3172 uint16_t fcs_calculated = crc16_calc(&packet[4], size - (4+2)); 3173 uint16_t fcs_packet = little_endian_read_16(packet, size-2); 3174 3175 #ifdef L2CAP_ERTM_SIMULATE_FCS_ERROR_INTERVAL 3176 // simulate fcs error 3177 static int counter = 0; 3178 if (++counter == L2CAP_ERTM_SIMULATE_FCS_ERROR_INTERVAL) { 3179 log_info("Simulate fcs error"); 3180 fcs_calculated++; 3181 counter = 0; 3182 } 3183 #endif 3184 3185 if (fcs_calculated == fcs_packet){ 3186 log_info("Packet FCS 0x%04x verified", fcs_packet); 3187 } else { 3188 log_error("FCS mismatch! Packet 0x%04x, calculated 0x%04x", fcs_packet, fcs_calculated); 3189 // ERTM State Machine in Bluetooth Spec does not handle 'I-Frame with invalid FCS' 3190 break; 3191 } 3192 } 3193 3194 // switch on packet type 3195 uint16_t control = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 3196 uint8_t req_seq = (control >> 8) & 0x3f; 3197 int final = (control >> 7) & 0x01; 3198 if (control & 1){ 3199 // S-Frame 3200 int poll = (control >> 4) & 0x01; 3201 l2cap_supervisory_function_t s = (l2cap_supervisory_function_t) ((control >> 2) & 0x03); 3202 log_info("Control: 0x%04x => Supervisory function %u, ReqSeq %02u", control, (int) s, req_seq); 3203 l2cap_ertm_tx_packet_state_t * tx_state; 3204 switch (s){ 3205 case L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY: 3206 log_info("L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY"); 3207 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 3208 if (poll && final){ 3209 // S-frames shall not be transmitted with both the F-bit and the P-bit set to 1 at the same time. 3210 log_error("P=F=1 in S-Frame"); 3211 break; 3212 } 3213 if (poll){ 3214 // check if we did request selective retransmission before <==> we have stored SDU segments 3215 int i; 3216 int num_stored_out_of_order_packets = 0; 3217 for (i=0;i<l2cap_channel->num_rx_buffers;i++){ 3218 int index = l2cap_channel->rx_store_index + i; 3219 if (index >= l2cap_channel->num_rx_buffers){ 3220 index -= l2cap_channel->num_rx_buffers; 3221 } 3222 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 3223 if (!rx_state->valid) continue; 3224 num_stored_out_of_order_packets++; 3225 } 3226 if (num_stored_out_of_order_packets){ 3227 l2cap_channel->send_supervisor_frame_selective_reject = 1; 3228 } else { 3229 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 3230 } 3231 l2cap_channel->set_final_bit_after_packet_with_poll_bit_set = 1; 3232 } 3233 if (final){ 3234 // Stop-MonitorTimer 3235 l2cap_ertm_stop_monitor_timer(l2cap_channel); 3236 // If UnackedFrames > 0 then Start-RetransTimer 3237 if (l2cap_channel->unacked_frames){ 3238 l2cap_ertm_start_retransmission_timer(l2cap_channel); 3239 } 3240 // final bit set <- response to RR with poll bit set. All not acknowledged packets need to be retransmitted 3241 l2cap_ertm_retransmit_unacknowleded_frames(l2cap_channel); 3242 } 3243 break; 3244 case L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT: 3245 log_info("L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT"); 3246 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 3247 // restart transmittion from last unacknowledted packet (earlier packets already freed in l2cap_ertm_process_req_seq) 3248 l2cap_ertm_retransmit_unacknowleded_frames(l2cap_channel); 3249 break; 3250 case L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY: 3251 log_error("L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY"); 3252 break; 3253 case L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT: 3254 log_info("L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT"); 3255 if (poll){ 3256 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 3257 } 3258 // find requested i-frame 3259 tx_state = l2cap_ertm_get_tx_state(l2cap_channel, req_seq); 3260 if (tx_state){ 3261 log_info("Retransmission for tx_seq %u requested", req_seq); 3262 l2cap_channel->set_final_bit_after_packet_with_poll_bit_set = poll; 3263 tx_state->retransmission_requested = 1; 3264 l2cap_channel->srej_active = 1; 3265 } 3266 break; 3267 default: 3268 break; 3269 } 3270 break; 3271 } else { 3272 // I-Frame 3273 // get control 3274 l2cap_segmentation_and_reassembly_t sar = (l2cap_segmentation_and_reassembly_t) (control >> 14); 3275 uint8_t tx_seq = (control >> 1) & 0x3f; 3276 log_info("Control: 0x%04x => SAR %u, ReqSeq %02u, R?, TxSeq %02u", control, (int) sar, req_seq, tx_seq); 3277 log_info("SAR: pos %u", l2cap_channel->reassembly_pos); 3278 log_info("State: expected_tx_seq %02u, req_seq %02u", l2cap_channel->expected_tx_seq, l2cap_channel->req_seq); 3279 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 3280 if (final){ 3281 // final bit set <- response to RR with poll bit set. All not acknowledged packets need to be retransmitted 3282 l2cap_ertm_retransmit_unacknowleded_frames(l2cap_channel); 3283 } 3284 3285 // get SDU 3286 const uint8_t * payload_data = &packet[COMPLETE_L2CAP_HEADER+2]; 3287 uint16_t payload_len = size-(COMPLETE_L2CAP_HEADER+2+fcs_size); 3288 3289 // assert SDU size is smaller or equal to our buffers 3290 uint16_t max_payload_size = 0; 3291 switch (sar){ 3292 case L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU: 3293 case L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU: 3294 // SDU Length + MPS 3295 max_payload_size = l2cap_channel->local_mps + 2; 3296 break; 3297 case L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU: 3298 case L2CAP_SEGMENTATION_AND_REASSEMBLY_END_OF_L2CAP_SDU: 3299 max_payload_size = l2cap_channel->local_mps; 3300 break; 3301 } 3302 if (payload_len > max_payload_size){ 3303 log_info("payload len %u > max payload %u -> drop packet", payload_len, max_payload_size); 3304 break; 3305 } 3306 3307 // check ordering 3308 if (l2cap_channel->expected_tx_seq == tx_seq){ 3309 log_info("Received expected frame with TxSeq == ExpectedTxSeq == %02u", tx_seq); 3310 l2cap_channel->expected_tx_seq = l2cap_next_ertm_seq_nr(l2cap_channel->expected_tx_seq); 3311 l2cap_channel->req_seq = l2cap_channel->expected_tx_seq; 3312 3313 // process SDU 3314 l2cap_ertm_handle_in_sequence_sdu(l2cap_channel, sar, payload_data, payload_len); 3315 3316 // process stored segments 3317 while (1){ 3318 int index = l2cap_channel->rx_store_index; 3319 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 3320 if (!rx_state->valid) break; 3321 3322 log_info("Processing stored frame with TxSeq == ExpectedTxSeq == %02u", l2cap_channel->expected_tx_seq); 3323 l2cap_channel->expected_tx_seq = l2cap_next_ertm_seq_nr(l2cap_channel->expected_tx_seq); 3324 l2cap_channel->req_seq = l2cap_channel->expected_tx_seq; 3325 3326 rx_state->valid = 0; 3327 l2cap_ertm_handle_in_sequence_sdu(l2cap_channel, rx_state->sar, &l2cap_channel->rx_packets_data[index], rx_state->len); 3328 3329 // update rx store index 3330 index++; 3331 if (index >= l2cap_channel->num_rx_buffers){ 3332 index = 0; 3333 } 3334 l2cap_channel->rx_store_index = index; 3335 } 3336 3337 // 3338 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 3339 3340 } else { 3341 int delta = (tx_seq - l2cap_channel->expected_tx_seq) & 0x3f; 3342 if (delta < 2){ 3343 // store segment 3344 l2cap_ertm_handle_out_of_sequence_sdu(l2cap_channel, sar, delta, payload_data, payload_len); 3345 3346 log_info("Received unexpected frame TxSeq %u but expected %u -> send S-SREJ", tx_seq, l2cap_channel->expected_tx_seq); 3347 l2cap_channel->send_supervisor_frame_selective_reject = 1; 3348 } else { 3349 log_info("Received unexpected frame TxSeq %u but expected %u -> send S-REJ", tx_seq, l2cap_channel->expected_tx_seq); 3350 l2cap_channel->send_supervisor_frame_reject = 1; 3351 } 3352 } 3353 } 3354 break; 3355 } 3356 #endif 3357 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 3358 } 3359 break; 3360 } 3361 #else 3362 UNUSED(handle); // ok: no code 3363 UNUSED(packet); // ok: no code 3364 UNUSED(size); // ok: no code 3365 #endif 3366 } 3367 3368 static void l2cap_acl_le_handler(hci_con_handle_t handle, uint8_t *packet, uint16_t size){ 3369 #ifdef ENABLE_BLE 3370 3371 l2cap_fixed_channel_t * l2cap_fixed_channel; 3372 3373 #ifdef ENABLE_LE_DATA_CHANNELS 3374 l2cap_channel_t * l2cap_channel; 3375 #endif 3376 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 3377 switch (channel_id) { 3378 3379 case L2CAP_CID_SIGNALING_LE: { 3380 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 3381 uint16_t len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER + 2); 3382 if (COMPLETE_L2CAP_HEADER + 4 + len > size) break; 3383 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 3384 if (!valid){ 3385 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 3386 } 3387 break; 3388 } 3389 3390 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 3391 l2cap_fixed_channel = l2cap_fixed_channel_for_channel_id(L2CAP_CID_ATTRIBUTE_PROTOCOL); 3392 if (!l2cap_fixed_channel) break; 3393 if (!l2cap_fixed_channel->packet_handler) break; 3394 (*l2cap_fixed_channel->packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 3395 break; 3396 3397 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 3398 l2cap_fixed_channel = l2cap_fixed_channel_for_channel_id(L2CAP_CID_SECURITY_MANAGER_PROTOCOL); 3399 if (!l2cap_fixed_channel) break; 3400 if (!l2cap_fixed_channel->packet_handler) break; 3401 (*l2cap_fixed_channel->packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 3402 break; 3403 3404 default: 3405 3406 #ifdef ENABLE_LE_DATA_CHANNELS 3407 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 3408 if (l2cap_channel) { 3409 // credit counting 3410 if (l2cap_channel->credits_incoming == 0){ 3411 log_error("LE Data Channel packet received but no incoming credits"); 3412 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3413 break; 3414 } 3415 l2cap_channel->credits_incoming--; 3416 3417 // automatic credits 3418 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 3419 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 3420 } 3421 3422 // first fragment 3423 uint16_t pos = 0; 3424 if (!l2cap_channel->receive_sdu_len){ 3425 uint16_t sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 3426 if(sdu_len > l2cap_channel->local_mtu) break; // SDU would be larger than our buffer 3427 l2cap_channel->receive_sdu_len = sdu_len; 3428 l2cap_channel->receive_sdu_pos = 0; 3429 pos += 2; 3430 size -= 2; 3431 } 3432 uint16_t fragment_size = size-COMPLETE_L2CAP_HEADER; 3433 uint16_t remaining_space = l2cap_channel->local_mtu - l2cap_channel->receive_sdu_pos; 3434 if (fragment_size > remaining_space) break; // SDU would cause buffer overrun 3435 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], fragment_size); 3436 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 3437 // done? 3438 log_debug("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 3439 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 3440 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 3441 l2cap_channel->receive_sdu_len = 0; 3442 } 3443 } else { 3444 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 3445 } 3446 #endif 3447 break; 3448 } 3449 #else 3450 UNUSED(handle); // ok: no code 3451 UNUSED(packet); // ok: no code 3452 UNUSED(size); // ok: no code 3453 #endif 3454 } 3455 3456 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3457 UNUSED(packet_type); // ok: registered with hci_register_acl_packet_handler 3458 UNUSED(channel); // ok: there is no channel 3459 3460 // Assert full L2CAP header present 3461 if (size < COMPLETE_L2CAP_HEADER) return; 3462 3463 // Dispatch to Classic or LE handler 3464 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 3465 hci_connection_t *conn = hci_connection_for_handle(handle); 3466 if (!conn) return; 3467 if (conn->address_type == BD_ADDR_TYPE_CLASSIC){ 3468 l2cap_acl_classic_handler(handle, packet, size); 3469 } else { 3470 l2cap_acl_le_handler(handle, packet, size); 3471 } 3472 3473 l2cap_run(); 3474 } 3475 3476 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 3477 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 3478 l2cap_fixed_channel_t * channel = l2cap_fixed_channel_for_channel_id(channel_id); 3479 if (!channel) return; 3480 channel->packet_handler = the_packet_handler; 3481 } 3482 3483 #ifdef ENABLE_CLASSIC 3484 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 3485 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 3486 channel->state = L2CAP_STATE_CLOSED; 3487 l2cap_handle_channel_closed(channel); 3488 // discard channel 3489 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 3490 l2cap_free_channel_entry(channel); 3491 } 3492 #endif 3493 3494 #ifdef L2CAP_USES_CHANNELS 3495 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 3496 btstack_linked_list_iterator_t it; 3497 btstack_linked_list_iterator_init(&it, services); 3498 while (btstack_linked_list_iterator_has_next(&it)){ 3499 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 3500 if ( service->psm == psm){ 3501 return service; 3502 }; 3503 } 3504 return NULL; 3505 } 3506 #endif 3507 3508 #ifdef ENABLE_CLASSIC 3509 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 3510 return l2cap_get_service_internal(&l2cap_services, psm); 3511 } 3512 3513 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 3514 3515 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 3516 3517 // check for alread registered psm 3518 l2cap_service_t *service = l2cap_get_service(psm); 3519 if (service) { 3520 log_error("l2cap_register_service: PSM %u already registered", psm); 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: no memory for l2cap_service_t"); 3528 return BTSTACK_MEMORY_ALLOC_FAILED; 3529 } 3530 3531 // fill in 3532 service->psm = psm; 3533 service->mtu = mtu; 3534 service->packet_handler = service_packet_handler; 3535 service->required_security_level = security_level; 3536 3537 // add to services list 3538 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 3539 3540 // enable page scan 3541 gap_connectable_control(1); 3542 3543 return 0; 3544 } 3545 3546 uint8_t l2cap_unregister_service(uint16_t psm){ 3547 3548 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 3549 3550 l2cap_service_t *service = l2cap_get_service(psm); 3551 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 3552 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 3553 btstack_memory_l2cap_service_free(service); 3554 3555 // disable page scan when no services registered 3556 if (btstack_linked_list_empty(&l2cap_services)) { 3557 gap_connectable_control(0); 3558 } 3559 return 0; 3560 } 3561 #endif 3562 3563 3564 #ifdef ENABLE_LE_DATA_CHANNELS 3565 3566 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 3567 if (!channel->waiting_for_can_send_now) return; 3568 if (channel->send_sdu_buffer) return; 3569 channel->waiting_for_can_send_now = 0; 3570 log_debug("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 3571 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 3572 } 3573 3574 // 1BH2222 3575 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 3576 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", 3577 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 3578 uint8_t event[19]; 3579 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 3580 event[1] = sizeof(event) - 2; 3581 event[2] = channel->address_type; 3582 reverse_bd_addr(channel->address, &event[3]); 3583 little_endian_store_16(event, 9, channel->con_handle); 3584 little_endian_store_16(event, 11, channel->psm); 3585 little_endian_store_16(event, 13, channel->local_cid); 3586 little_endian_store_16(event, 15, channel->remote_cid); 3587 little_endian_store_16(event, 17, channel->remote_mtu); 3588 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 3589 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 3590 } 3591 // 11BH22222 3592 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 3593 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", 3594 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 3595 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 3596 uint8_t event[23]; 3597 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 3598 event[1] = sizeof(event) - 2; 3599 event[2] = status; 3600 event[3] = channel->address_type; 3601 reverse_bd_addr(channel->address, &event[4]); 3602 little_endian_store_16(event, 10, channel->con_handle); 3603 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 3604 little_endian_store_16(event, 13, channel->psm); 3605 little_endian_store_16(event, 15, channel->local_cid); 3606 little_endian_store_16(event, 17, channel->remote_cid); 3607 little_endian_store_16(event, 19, channel->local_mtu); 3608 little_endian_store_16(event, 21, channel->remote_mtu); 3609 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 3610 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 3611 } 3612 // 2 3613 static void l2cap_emit_le_channel_closed(l2cap_channel_t * channel){ 3614 log_info("L2CAP_EVENT_LE_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 3615 uint8_t event[4]; 3616 event[0] = L2CAP_EVENT_LE_CHANNEL_CLOSED; 3617 event[1] = sizeof(event) - 2; 3618 little_endian_store_16(event, 2, channel->local_cid); 3619 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 3620 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 3621 } 3622 3623 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 3624 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 3625 channel->state = L2CAP_STATE_CLOSED; 3626 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 3627 // discard channel 3628 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 3629 l2cap_free_channel_entry(channel); 3630 } 3631 3632 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 3633 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 3634 } 3635 3636 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 3637 3638 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 3639 3640 // check for alread registered psm 3641 l2cap_service_t *service = l2cap_le_get_service(psm); 3642 if (service) { 3643 return L2CAP_SERVICE_ALREADY_REGISTERED; 3644 } 3645 3646 // alloc structure 3647 service = btstack_memory_l2cap_service_get(); 3648 if (!service) { 3649 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 3650 return BTSTACK_MEMORY_ALLOC_FAILED; 3651 } 3652 3653 // fill in 3654 service->psm = psm; 3655 service->mtu = 0; 3656 service->packet_handler = packet_handler; 3657 service->required_security_level = security_level; 3658 3659 // add to services list 3660 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 3661 3662 // done 3663 return 0; 3664 } 3665 3666 uint8_t l2cap_le_unregister_service(uint16_t psm) { 3667 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 3668 l2cap_service_t *service = l2cap_le_get_service(psm); 3669 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 3670 3671 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 3672 btstack_memory_l2cap_service_free(service); 3673 return 0; 3674 } 3675 3676 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 3677 // get channel 3678 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 3679 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3680 3681 // validate state 3682 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 3683 return ERROR_CODE_COMMAND_DISALLOWED; 3684 } 3685 3686 // set state accept connection 3687 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 3688 channel->receive_sdu_buffer = receive_sdu_buffer; 3689 channel->local_mtu = mtu; 3690 channel->new_credits_incoming = initial_credits; 3691 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 3692 3693 // test 3694 // channel->new_credits_incoming = 1; 3695 3696 // go 3697 l2cap_run(); 3698 return 0; 3699 } 3700 3701 /** 3702 * @brief Deny incoming LE Data Channel connection due to resource constraints 3703 * @param local_cid L2CAP LE Data Channel Identifier 3704 */ 3705 3706 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 3707 // get channel 3708 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 3709 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3710 3711 // validate state 3712 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 3713 return ERROR_CODE_COMMAND_DISALLOWED; 3714 } 3715 3716 // set state decline connection 3717 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 3718 channel->reason = 0x04; // no resources available 3719 l2cap_run(); 3720 return 0; 3721 } 3722 3723 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 3724 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 3725 uint16_t * out_local_cid) { 3726 3727 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 3728 3729 3730 hci_connection_t * connection = hci_connection_for_handle(con_handle); 3731 if (!connection) { 3732 log_error("no hci_connection for handle 0x%04x", con_handle); 3733 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 3734 } 3735 3736 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); 3737 if (!channel) { 3738 return BTSTACK_MEMORY_ALLOC_FAILED; 3739 } 3740 log_info("l2cap_le_create_channel %p", channel); 3741 3742 // store local_cid 3743 if (out_local_cid){ 3744 *out_local_cid = channel->local_cid; 3745 } 3746 3747 // provide buffer 3748 channel->con_handle = con_handle; 3749 channel->receive_sdu_buffer = receive_sdu_buffer; 3750 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 3751 channel->new_credits_incoming = initial_credits; 3752 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 3753 3754 // add to connections list 3755 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 3756 3757 // go 3758 l2cap_run(); 3759 return 0; 3760 } 3761 3762 /** 3763 * @brief Provide credtis for LE Data Channel 3764 * @param local_cid L2CAP LE Data Channel Identifier 3765 * @param credits Number additional credits for peer 3766 */ 3767 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 3768 3769 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 3770 if (!channel) { 3771 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 3772 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3773 } 3774 3775 // check state 3776 if (channel->state != L2CAP_STATE_OPEN){ 3777 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 3778 } 3779 3780 // assert incoming credits + credits <= 0xffff 3781 uint32_t total_credits = channel->credits_incoming; 3782 total_credits += channel->new_credits_incoming; 3783 total_credits += credits; 3784 if (total_credits > 0xffff){ 3785 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 3786 channel->new_credits_incoming, credits); 3787 } 3788 3789 // set credits_granted 3790 channel->new_credits_incoming += credits; 3791 3792 // go 3793 l2cap_run(); 3794 return 0; 3795 } 3796 3797 /** 3798 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 3799 * @param local_cid L2CAP LE Data Channel Identifier 3800 */ 3801 int l2cap_le_can_send_now(uint16_t local_cid){ 3802 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 3803 if (!channel) { 3804 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 3805 return 0; 3806 } 3807 3808 // check state 3809 if (channel->state != L2CAP_STATE_OPEN) return 0; 3810 3811 // check queue 3812 if (channel->send_sdu_buffer) return 0; 3813 3814 // fine, go ahead 3815 return 1; 3816 } 3817 3818 /** 3819 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 3820 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 3821 * so packet handler should be ready to handle it 3822 * @param local_cid L2CAP LE Data Channel Identifier 3823 */ 3824 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 3825 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 3826 if (!channel) { 3827 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 3828 return 0; 3829 } 3830 channel->waiting_for_can_send_now = 1; 3831 l2cap_le_notify_channel_can_send(channel); 3832 return 0; 3833 } 3834 3835 /** 3836 * @brief Send data via LE Data Channel 3837 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 3838 * @param local_cid L2CAP LE Data Channel Identifier 3839 * @param data data to send 3840 * @param size data size 3841 */ 3842 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 3843 3844 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 3845 if (!channel) { 3846 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 3847 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3848 } 3849 3850 if (len > channel->remote_mtu){ 3851 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 3852 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 3853 } 3854 3855 if (channel->send_sdu_buffer){ 3856 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 3857 return BTSTACK_ACL_BUFFERS_FULL; 3858 } 3859 3860 channel->send_sdu_buffer = data; 3861 channel->send_sdu_len = len; 3862 channel->send_sdu_pos = 0; 3863 3864 l2cap_run(); 3865 return 0; 3866 } 3867 3868 /** 3869 * @brief Disconnect from LE Data Channel 3870 * @param local_cid L2CAP LE Data Channel Identifier 3871 */ 3872 uint8_t l2cap_le_disconnect(uint16_t local_cid) 3873 { 3874 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 3875 if (!channel) { 3876 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 3877 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3878 } 3879 3880 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3881 l2cap_run(); 3882 return 0; 3883 } 3884 3885 #endif 3886