1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #define __BTSTACK_FILE__ "l2cap.c" 39 40 /* 41 * l2cap.c 42 * 43 * Logical Link Control and Adaption Protocl (L2CAP) 44 * 45 * Created by Matthias Ringwald on 5/16/09. 46 */ 47 48 #include "l2cap.h" 49 #include "hci.h" 50 #include "hci_dump.h" 51 #include "bluetooth_sdp.h" 52 #include "btstack_debug.h" 53 #include "btstack_event.h" 54 #include "btstack_memory.h" 55 56 #ifdef ENABLE_LE_DATA_CHANNELS 57 #include "ble/sm.h" 58 #endif 59 60 #include <stdarg.h> 61 #include <string.h> 62 63 #include <stdio.h> 64 65 // nr of buffered acl packets in outgoing queue to get max performance 66 #define NR_BUFFERED_ACL_PACKETS 3 67 68 // used to cache l2cap rejects, echo, and informational requests 69 #define NR_PENDING_SIGNALING_RESPONSES 3 70 71 // nr of credits provided to remote if credits fall below watermark 72 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK 5 73 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT 5 74 75 // offsets for L2CAP SIGNALING COMMANDS 76 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 77 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 78 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 79 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 80 81 // internal table 82 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL 0 83 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL 1 84 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL 2 85 #define L2CAP_FIXED_CHANNEL_TABLE_SIZE (L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL+1) 86 87 #if defined(ENABLE_LE_DATA_CHANNELS) || defined(ENABLE_CLASSIC) 88 #define L2CAP_USES_CHANNELS 89 #endif 90 91 // prototypes 92 static void l2cap_run(void); 93 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 94 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ); 95 static void l2cap_notify_channel_can_send(void); 96 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel); 97 #ifdef ENABLE_CLASSIC 98 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel); 99 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel); 100 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 101 static inline l2cap_service_t * l2cap_get_service(uint16_t psm); 102 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 103 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 104 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel); 105 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 106 #endif 107 #ifdef ENABLE_LE_DATA_CHANNELS 108 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status); 109 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel); 110 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid); 111 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel); 112 static void l2cap_le_finialize_channel_close(l2cap_channel_t *channel); 113 static inline l2cap_service_t * l2cap_le_get_service(uint16_t psm); 114 #endif 115 #ifdef L2CAP_USES_CHANNELS 116 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size); 117 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid); 118 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 119 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level); 120 #endif 121 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 122 static void l2cap_ertm_notify_channel_can_send(l2cap_channel_t * channel); 123 static void l2cap_ertm_monitor_timeout_callback(btstack_timer_source_t * ts); 124 static void l2cap_ertm_retransmission_timeout_callback(btstack_timer_source_t * ts); 125 #endif 126 127 typedef struct l2cap_fixed_channel { 128 btstack_packet_handler_t callback; 129 uint8_t waiting_for_can_send_now; 130 } l2cap_fixed_channel_t; 131 132 #ifdef ENABLE_CLASSIC 133 static btstack_linked_list_t l2cap_channels; 134 static btstack_linked_list_t l2cap_services; 135 static uint8_t require_security_level2_for_outgoing_sdp; 136 #endif 137 138 #ifdef ENABLE_LE_DATA_CHANNELS 139 static btstack_linked_list_t l2cap_le_channels; 140 static btstack_linked_list_t l2cap_le_services; 141 #endif 142 143 // used to cache l2cap rejects, echo, and informational requests 144 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 145 static int signaling_responses_pending; 146 147 static btstack_packet_callback_registration_t hci_event_callback_registration; 148 static l2cap_fixed_channel_t fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_SIZE]; 149 150 #ifdef ENABLE_BLE 151 // only used for connection parameter update events 152 static btstack_packet_handler_t l2cap_event_packet_handler; 153 #endif 154 155 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 156 157 /* 158 * CRC lookup table for generator polynom D^16 + D^15 + D^2 + 1 159 */ 160 static const uint16_t crc16_table[256] = { 161 0x0000, 0xc0c1, 0xc181, 0x0140, 0xc301, 0x03c0, 0x0280, 0xc241, 0xc601, 0x06c0, 0x0780, 0xc741, 0x0500, 0xc5c1, 0xc481, 0x0440, 162 0xcc01, 0x0cc0, 0x0d80, 0xcd41, 0x0f00, 0xcfc1, 0xce81, 0x0e40, 0x0a00, 0xcac1, 0xcb81, 0x0b40, 0xc901, 0x09c0, 0x0880, 0xc841, 163 0xd801, 0x18c0, 0x1980, 0xd941, 0x1b00, 0xdbc1, 0xda81, 0x1a40, 0x1e00, 0xdec1, 0xdf81, 0x1f40, 0xdd01, 0x1dc0, 0x1c80, 0xdc41, 164 0x1400, 0xd4c1, 0xd581, 0x1540, 0xd701, 0x17c0, 0x1680, 0xd641, 0xd201, 0x12c0, 0x1380, 0xd341, 0x1100, 0xd1c1, 0xd081, 0x1040, 165 0xf001, 0x30c0, 0x3180, 0xf141, 0x3300, 0xf3c1, 0xf281, 0x3240, 0x3600, 0xf6c1, 0xf781, 0x3740, 0xf501, 0x35c0, 0x3480, 0xf441, 166 0x3c00, 0xfcc1, 0xfd81, 0x3d40, 0xff01, 0x3fc0, 0x3e80, 0xfe41, 0xfa01, 0x3ac0, 0x3b80, 0xfb41, 0x3900, 0xf9c1, 0xf881, 0x3840, 167 0x2800, 0xe8c1, 0xe981, 0x2940, 0xeb01, 0x2bc0, 0x2a80, 0xea41, 0xee01, 0x2ec0, 0x2f80, 0xef41, 0x2d00, 0xedc1, 0xec81, 0x2c40, 168 0xe401, 0x24c0, 0x2580, 0xe541, 0x2700, 0xe7c1, 0xe681, 0x2640, 0x2200, 0xe2c1, 0xe381, 0x2340, 0xe101, 0x21c0, 0x2080, 0xe041, 169 0xa001, 0x60c0, 0x6180, 0xa141, 0x6300, 0xa3c1, 0xa281, 0x6240, 0x6600, 0xa6c1, 0xa781, 0x6740, 0xa501, 0x65c0, 0x6480, 0xa441, 170 0x6c00, 0xacc1, 0xad81, 0x6d40, 0xaf01, 0x6fc0, 0x6e80, 0xae41, 0xaa01, 0x6ac0, 0x6b80, 0xab41, 0x6900, 0xa9c1, 0xa881, 0x6840, 171 0x7800, 0xb8c1, 0xb981, 0x7940, 0xbb01, 0x7bc0, 0x7a80, 0xba41, 0xbe01, 0x7ec0, 0x7f80, 0xbf41, 0x7d00, 0xbdc1, 0xbc81, 0x7c40, 172 0xb401, 0x74c0, 0x7580, 0xb541, 0x7700, 0xb7c1, 0xb681, 0x7640, 0x7200, 0xb2c1, 0xb381, 0x7340, 0xb101, 0x71c0, 0x7080, 0xb041, 173 0x5000, 0x90c1, 0x9181, 0x5140, 0x9301, 0x53c0, 0x5280, 0x9241, 0x9601, 0x56c0, 0x5780, 0x9741, 0x5500, 0x95c1, 0x9481, 0x5440, 174 0x9c01, 0x5cc0, 0x5d80, 0x9d41, 0x5f00, 0x9fc1, 0x9e81, 0x5e40, 0x5a00, 0x9ac1, 0x9b81, 0x5b40, 0x9901, 0x59c0, 0x5880, 0x9841, 175 0x8801, 0x48c0, 0x4980, 0x8941, 0x4b00, 0x8bc1, 0x8a81, 0x4a40, 0x4e00, 0x8ec1, 0x8f81, 0x4f40, 0x8d01, 0x4dc0, 0x4c80, 0x8c41, 176 0x4400, 0x84c1, 0x8581, 0x4540, 0x8701, 0x47c0, 0x4680, 0x8641, 0x8201, 0x42c0, 0x4380, 0x8341, 0x4100, 0x81c1, 0x8081, 0x4040, 177 }; 178 179 static uint16_t crc16_calc(uint8_t * data, uint16_t len){ 180 uint16_t crc = 0; // initial value = 0 181 while (len--){ 182 crc = (crc >> 8) ^ crc16_table[ (crc ^ ((uint16_t) *data++)) & 0x00FF ]; 183 } 184 return crc; 185 } 186 187 static inline uint16_t l2cap_encanced_control_field_for_information_frame(uint8_t tx_seq, int final, uint8_t req_seq, l2cap_segmentation_and_reassembly_t sar){ 188 return (((uint16_t) sar) << 14) | (req_seq << 8) | (final << 7) | (tx_seq << 1) | 0; 189 } 190 191 static inline uint16_t l2cap_encanced_control_field_for_supevisor_frame(l2cap_supervisory_function_t supervisory_function, int poll, int final, uint8_t req_seq){ 192 return (req_seq << 8) | (final << 7) | (poll << 4) | (((int) supervisory_function) << 2) | 1; 193 } 194 195 static int l2cap_next_ertm_seq_nr(int seq_nr){ 196 return (seq_nr + 1) & 0x3f; 197 } 198 199 static int l2cap_ertm_can_store_packet_now(l2cap_channel_t * channel){ 200 // get num free tx buffers 201 int num_tx_buffers_used = channel->tx_write_index - channel->tx_read_index; 202 if (num_tx_buffers_used < 0){ 203 num_tx_buffers_used += channel->num_tx_buffers; 204 } 205 int num_free_tx_buffers = channel->num_tx_buffers - num_tx_buffers_used; 206 // calculate num tx buffers for remote MTU 207 int num_tx_buffers_for_max_remote_mtu; 208 if (channel->remote_mtu <= channel->remote_mps){ 209 // MTU fits into single packet 210 num_tx_buffers_for_max_remote_mtu = 1; 211 } else { 212 // include SDU Length 213 num_tx_buffers_for_max_remote_mtu = (channel->remote_mtu + 2 + (channel->remote_mps - 1)) / channel->remote_mps; 214 } 215 return num_tx_buffers_for_max_remote_mtu <= num_free_tx_buffers; 216 } 217 218 static void l2cap_ertm_next_tx_write_index(l2cap_channel_t * channel){ 219 channel->tx_write_index++; 220 if (channel->tx_write_index < channel->num_tx_buffers) return; 221 channel->tx_write_index = 0; 222 } 223 224 static void l2cap_ertm_start_monitor_timer(l2cap_channel_t * channel){ 225 log_info("Start Monitor timer"); 226 btstack_run_loop_remove_timer(&channel->monitor_timer); 227 btstack_run_loop_set_timer_handler(&channel->monitor_timer, &l2cap_ertm_monitor_timeout_callback); 228 btstack_run_loop_set_timer_context(&channel->monitor_timer, channel); 229 btstack_run_loop_set_timer(&channel->monitor_timer, channel->local_monitor_timeout_ms); 230 btstack_run_loop_add_timer(&channel->monitor_timer); 231 } 232 233 static void l2cap_ertm_stop_monitor_timer(l2cap_channel_t * channel){ 234 log_info("Stop Monitor timer"); 235 btstack_run_loop_remove_timer(&channel->monitor_timer); 236 } 237 238 static void l2cap_ertm_start_retransmission_timer(l2cap_channel_t * channel){ 239 log_info("Start Retransmission timer"); 240 btstack_run_loop_remove_timer(&channel->retransmission_timer); 241 btstack_run_loop_set_timer_handler(&channel->retransmission_timer, &l2cap_ertm_retransmission_timeout_callback); 242 btstack_run_loop_set_timer_context(&channel->retransmission_timer, channel); 243 btstack_run_loop_set_timer(&channel->retransmission_timer, channel->local_retransmission_timeout_ms); 244 btstack_run_loop_add_timer(&channel->retransmission_timer); 245 } 246 247 static void l2cap_ertm_stop_retransmission_timer(l2cap_channel_t * l2cap_channel){ 248 log_info("Stop Retransmission timer"); 249 btstack_run_loop_remove_timer(&l2cap_channel->retransmission_timer); 250 } 251 252 static void l2cap_ertm_monitor_timeout_callback(btstack_timer_source_t * ts){ 253 log_info("Monitor timeout"); 254 l2cap_channel_t * l2cap_channel = (l2cap_channel_t *) btstack_run_loop_get_timer_context(ts); 255 256 // TODO: we assume that it's the oldest packet 257 l2cap_ertm_tx_packet_state_t * tx_state; 258 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 259 260 // check retry count 261 if (tx_state->retry_count < l2cap_channel->remote_max_transmit){ 262 // increment retry count 263 tx_state->retry_count++; 264 265 l2cap_ertm_start_monitor_timer(l2cap_channel); 266 267 // send RR/P=1 268 l2cap_channel->send_supervisor_frame_receiver_ready_poll = 1; 269 } else { 270 log_info("Monitor timer expired & retry count >= max transmit -> disconnect"); 271 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 272 } 273 l2cap_run(); 274 } 275 276 static void l2cap_ertm_retransmission_timeout_callback(btstack_timer_source_t * ts){ 277 log_info("Retransmission timeout"); 278 l2cap_channel_t * l2cap_channel = (l2cap_channel_t *) btstack_run_loop_get_timer_context(ts); 279 280 // TODO: we assume that it's the oldest packet 281 l2cap_ertm_tx_packet_state_t * tx_state; 282 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 283 284 // set retry count = 1 285 tx_state->retry_count = 1; 286 287 // start monitor timer 288 l2cap_ertm_start_monitor_timer(l2cap_channel); 289 290 // send RR/P=1 291 l2cap_channel->send_supervisor_frame_receiver_ready_poll = 1; 292 l2cap_run(); 293 } 294 295 static int l2cap_ertm_send_information_frame(l2cap_channel_t * channel, int index, int final){ 296 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[index]; 297 hci_reserve_packet_buffer(); 298 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 299 uint16_t control = l2cap_encanced_control_field_for_information_frame(tx_state->tx_seq, final, channel->req_seq, tx_state->sar); 300 log_info("I-Frame: control 0x%04x", control); 301 little_endian_store_16(acl_buffer, 8, control); 302 memcpy(&acl_buffer[8+2], &channel->tx_packets_data[index * channel->local_mtu], tx_state->len); 303 // (re-)start retransmission timer on 304 l2cap_ertm_start_retransmission_timer(channel); 305 // send 306 return l2cap_send_prepared(channel->local_cid, 2 + tx_state->len); 307 } 308 309 static void l2cap_ertm_store_fragment(l2cap_channel_t * channel, l2cap_segmentation_and_reassembly_t sar, uint16_t sdu_length, uint8_t * data, uint16_t len){ 310 // get next index for storing packets 311 int index = channel->tx_write_index; 312 313 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[index]; 314 tx_state->tx_seq = channel->next_tx_seq; 315 tx_state->len = len; 316 tx_state->sar = sar; 317 tx_state->retry_count = 0; 318 319 uint8_t * tx_packet = &channel->tx_packets_data[index * channel->local_mtu]; 320 int pos = 0; 321 if (sar == L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU){ 322 little_endian_store_16(tx_packet, 0, sdu_length); 323 pos += 2; 324 } 325 memcpy(&tx_packet[pos], data, len); 326 327 // update 328 channel->next_tx_seq = l2cap_next_ertm_seq_nr(channel->next_tx_seq); 329 l2cap_ertm_next_tx_write_index(channel); 330 331 log_info("l2cap_ertm_store_fragment: after store, tx_read_index %u, tx_write_index %u", channel->tx_read_index, channel->tx_write_index); 332 333 } 334 335 static int l2cap_ertm_send(l2cap_channel_t * channel, uint8_t * data, uint16_t len){ 336 if (len > channel->remote_mtu){ 337 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", channel->local_cid); 338 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 339 } 340 341 // check if it needs to get fragmented 342 if (len > channel->remote_mps){ 343 // fragmentation needed. 344 l2cap_segmentation_and_reassembly_t sar = L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU; 345 int chunk_len; 346 while (len){ 347 switch (sar){ 348 case L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU: 349 chunk_len = channel->remote_mps - 2; // sdu_length 350 l2cap_ertm_store_fragment(channel, sar, len, data, chunk_len); 351 len -= chunk_len; 352 sar = L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU; 353 break; 354 case L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU: 355 chunk_len = channel->remote_mps; 356 if (chunk_len >= len){ 357 sar = L2CAP_SEGMENTATION_AND_REASSEMBLY_END_OF_L2CAP_SDU; 358 chunk_len = len; 359 } 360 l2cap_ertm_store_fragment(channel, sar, len, data, chunk_len); 361 len -= chunk_len; 362 break; 363 default: 364 break; 365 } 366 } 367 368 } else { 369 l2cap_ertm_store_fragment(channel, L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU, 0, data, len); 370 } 371 372 // try to send 373 l2cap_run(); 374 return 0; 375 } 376 377 static uint16_t l2cap_setup_options_ertm(l2cap_channel_t * channel, uint8_t * config_options){ 378 config_options[0] = 0x04; // RETRANSMISSION AND FLOW CONTROL OPTION 379 config_options[1] = 9; // length 380 config_options[2] = (uint8_t) channel->mode; 381 config_options[3] = channel->num_rx_buffers; // == TxWindows size 382 config_options[4] = channel->local_max_transmit; 383 little_endian_store_16( config_options, 5, channel->local_retransmission_timeout_ms); 384 little_endian_store_16( config_options, 7, channel->local_monitor_timeout_ms); 385 little_endian_store_16( config_options, 9, channel->local_mps); 386 return 11; 387 } 388 389 static int l2cap_ertm_send_supervisor_frame(l2cap_channel_t * channel, uint16_t control){ 390 hci_reserve_packet_buffer(); 391 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 392 log_info("S-Frame: control 0x%04x", control); 393 little_endian_store_16(acl_buffer, 8, control); 394 return l2cap_send_prepared(channel->local_cid, 2); 395 } 396 397 static uint8_t l2cap_ertm_validate_local_config(l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size){ 398 399 UNUSED(buffer); 400 UNUSED(size); 401 402 uint8_t result = ERROR_CODE_SUCCESS; 403 if (ertm_config->max_transmit < 1){ 404 log_error("max_transmit must be >= 1"); 405 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 406 } 407 if (ertm_config->retransmission_timeout_ms < 2000){ 408 log_error("retransmission_timeout_ms must be >= 2000 ms"); 409 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 410 } 411 if (ertm_config->monitor_timeout_ms < 12000){ 412 log_error("monitor_timeout_ms must be >= 12000 ms"); 413 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 414 } 415 if (ertm_config->local_mtu < 48){ 416 log_error("local_mtu must be >= 48"); 417 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 418 } 419 if (ertm_config->num_rx_buffers < 1){ 420 log_error("num_rx_buffers must be >= 1"); 421 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 422 } 423 if (ertm_config->num_tx_buffers < 1){ 424 log_error("num_rx_buffers must be >= 1"); 425 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 426 } 427 return result; 428 } 429 430 static void l2cap_ertm_configure_channel(l2cap_channel_t * channel, l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size){ 431 432 channel->mode = L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION; 433 channel->ertm_mandatory = ertm_config->ertm_mandatory; 434 channel->local_max_transmit = ertm_config->max_transmit; 435 channel->local_retransmission_timeout_ms = ertm_config->retransmission_timeout_ms; 436 channel->local_monitor_timeout_ms = ertm_config->monitor_timeout_ms; 437 channel->local_mtu = ertm_config->local_mtu; 438 channel->num_rx_buffers = ertm_config->num_rx_buffers; 439 channel->num_tx_buffers = ertm_config->num_tx_buffers; 440 441 // align buffer to 16-byte boundary, just in case 442 int bytes_till_alignment = 16 - (((uintptr_t) buffer) & 0x0f); 443 buffer += bytes_till_alignment; 444 size -= bytes_till_alignment; 445 446 // setup state buffers 447 uint32_t pos = 0; 448 channel->rx_packets_state = (l2cap_ertm_rx_packet_state_t *) &buffer[pos]; 449 pos += ertm_config->num_rx_buffers * sizeof(l2cap_ertm_rx_packet_state_t); 450 channel->tx_packets_state = (l2cap_ertm_tx_packet_state_t *) &buffer[pos]; 451 pos += ertm_config->num_tx_buffers * sizeof(l2cap_ertm_tx_packet_state_t); 452 453 // setup reassembly buffer 454 channel->reassembly_buffer = &buffer[pos]; 455 pos += ertm_config->local_mtu; 456 457 // divide rest of data equally 458 channel->local_mps = (size - pos) / (ertm_config->num_rx_buffers + ertm_config->num_tx_buffers); 459 log_info("Local MPS: %u", channel->local_mtu); 460 channel->rx_packets_data = &buffer[pos]; 461 pos += ertm_config->num_rx_buffers * channel->local_mtu; 462 channel->tx_packets_data = &buffer[pos]; 463 } 464 465 uint8_t l2cap_create_ertm_channel(btstack_packet_handler_t packet_handler, bd_addr_t address, uint16_t psm, 466 l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size, uint16_t * out_local_cid){ 467 468 log_info("L2CAP_CREATE_ERTM_CHANNEL addr %s, psm 0x%x, local mtu %u", bd_addr_to_str(address), psm, ertm_config->local_mtu); 469 470 // validate local config 471 uint8_t result = l2cap_ertm_validate_local_config(ertm_config, buffer, size); 472 if (result) return result; 473 474 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, ertm_config->local_mtu, LEVEL_0); 475 if (!channel) { 476 return BTSTACK_MEMORY_ALLOC_FAILED; 477 } 478 479 // configure ERTM 480 l2cap_ertm_configure_channel(channel, ertm_config, buffer, size); 481 482 // add to connections list 483 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 484 485 // store local_cid 486 if (out_local_cid){ 487 *out_local_cid = channel->local_cid; 488 } 489 490 // check if hci connection is already usable 491 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 492 if (conn){ 493 log_info("l2cap_create_channel, hci connection already exists"); 494 l2cap_handle_connection_complete(conn->con_handle, channel); 495 // check if remote supported fearures are already received 496 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 497 l2cap_handle_remote_supported_features_received(channel); 498 } 499 } 500 501 l2cap_run(); 502 503 return 0; 504 } 505 506 static void l2cap_ertm_notify_channel_can_send(l2cap_channel_t * channel){ 507 if (l2cap_ertm_can_store_packet_now(channel)){ 508 channel->waiting_for_can_send_now = 0; 509 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 510 } 511 } 512 513 uint8_t l2cap_accept_ertm_connection(uint16_t local_cid, l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size){ 514 515 log_info("L2CAP_ACCEPT_ERTM_CONNECTION local_cid 0x%x", local_cid); 516 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 517 if (!channel) { 518 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 519 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 520 } 521 522 // validate local config 523 uint8_t result = l2cap_ertm_validate_local_config(ertm_config, buffer, size); 524 if (result) return result; 525 526 // configure L2CAP ERTM 527 l2cap_ertm_configure_channel(channel, ertm_config, buffer, size); 528 529 // continue 530 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 531 532 // process 533 l2cap_run(); 534 535 return ERROR_CODE_SUCCESS; 536 } 537 538 uint8_t l2cap_ertm_set_busy(uint16_t local_cid){ 539 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 540 if (!channel) { 541 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 542 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 543 } 544 if (!channel->local_busy){ 545 channel->local_busy = 1; 546 channel->send_supervisor_frame_receiver_not_ready = 1; 547 l2cap_run(); 548 } 549 return ERROR_CODE_SUCCESS; 550 } 551 552 uint8_t l2cap_ertm_set_ready(uint16_t local_cid){ 553 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 554 if (!channel) { 555 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 556 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 557 } 558 if (channel->local_busy){ 559 channel->local_busy = 0; 560 channel->send_supervisor_frame_receiver_ready_poll = 1; 561 l2cap_run(); 562 } 563 return ERROR_CODE_SUCCESS; 564 } 565 566 // Process-ReqSeq 567 static void l2cap_ertm_process_req_seq(l2cap_channel_t * l2cap_channel, uint8_t req_seq){ 568 int num_buffers_acked = 0; 569 l2cap_ertm_tx_packet_state_t * tx_state; 570 log_info("l2cap_ertm_process_req_seq: tx_read_index %u, tx_write_index %u, req_seq %u", l2cap_channel->tx_read_index, l2cap_channel->tx_write_index, req_seq); 571 while (1){ 572 573 // no unack packets left 574 if (l2cap_channel->unacked_frames == 0) { 575 // stop retransmission timer 576 l2cap_ertm_stop_retransmission_timer(l2cap_channel); 577 break; 578 } 579 580 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 581 // calc delta 582 int delta = (req_seq - tx_state->tx_seq) & 0x03f; 583 if (delta == 0) break; // all packets acknowledged 584 if (delta > l2cap_channel->remote_tx_window_size) break; 585 586 num_buffers_acked++; 587 l2cap_channel->unacked_frames--; 588 log_info("RR seq %u => packet with tx_seq %u done", req_seq, tx_state->tx_seq); 589 590 l2cap_channel->tx_read_index++; 591 if (l2cap_channel->tx_read_index >= l2cap_channel->num_rx_buffers){ 592 l2cap_channel->tx_read_index = 0; 593 } 594 } 595 596 if (num_buffers_acked){ 597 l2cap_ertm_notify_channel_can_send(l2cap_channel); 598 } 599 } 600 601 static l2cap_ertm_tx_packet_state_t * l2cap_ertm_get_tx_state(l2cap_channel_t * l2cap_channel, uint8_t tx_seq){ 602 int i; 603 for (i=0;i<l2cap_channel->num_tx_buffers;i++){ 604 l2cap_ertm_tx_packet_state_t * tx_state = &l2cap_channel->tx_packets_state[i]; 605 if (tx_state->tx_seq == tx_seq) return tx_state; 606 } 607 return NULL; 608 } 609 610 // @param delta number of frames in the future, >= 1 611 static void l2cap_ertm_handle_out_of_sequence_sdu(l2cap_channel_t * l2cap_channel, l2cap_segmentation_and_reassembly_t sar, int delta, uint8_t * payload, uint16_t size){ 612 log_info("Store SDU with delta %u", delta); 613 // get rx state for packet to store 614 int index = l2cap_channel->rx_store_index + delta - 1; 615 if (index > l2cap_channel->num_rx_buffers){ 616 index -= l2cap_channel->num_rx_buffers; 617 } 618 log_info("Index of packet to store %u", index); 619 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 620 // check if buffer is free 621 if (rx_state->valid){ 622 log_error("Packet buffer already used"); 623 return; 624 } 625 rx_state->valid = 1; 626 rx_state->sar = sar; 627 rx_state->len = size; 628 uint8_t * rx_buffer = &l2cap_channel->rx_packets_data[index]; 629 memcpy(rx_buffer, payload, size); 630 } 631 632 static void l2cap_ertm_handle_in_sequence_sdu(l2cap_channel_t * l2cap_channel, l2cap_segmentation_and_reassembly_t sar, uint8_t * payload, uint16_t size){ 633 switch (sar){ 634 case L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU: 635 // packet complete -> disapatch 636 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, payload, size); 637 break; 638 case L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU: 639 // TODO: check if reassembly started 640 // TODO: check sdu_len against local mtu 641 l2cap_channel->reassembly_sdu_length = little_endian_read_16(payload, 0); 642 payload += 2; 643 size -= 2; 644 memcpy(&l2cap_channel->reassembly_buffer[0], payload, size); 645 l2cap_channel->reassembly_pos = size; 646 break; 647 case L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU: 648 memcpy(&l2cap_channel->reassembly_buffer[l2cap_channel->reassembly_pos], payload, size); 649 l2cap_channel->reassembly_pos += size; 650 break; 651 case L2CAP_SEGMENTATION_AND_REASSEMBLY_END_OF_L2CAP_SDU: 652 memcpy(&l2cap_channel->reassembly_buffer[l2cap_channel->reassembly_pos], payload, size); 653 l2cap_channel->reassembly_pos += size; 654 // packet complete -> disapatch 655 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->reassembly_buffer, l2cap_channel->reassembly_pos); 656 l2cap_channel->reassembly_pos = 0; 657 break; 658 } 659 } 660 661 #endif 662 663 664 static uint16_t l2cap_fixed_channel_table_channel_id_for_index(int index){ 665 switch (index){ 666 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL: 667 return L2CAP_CID_ATTRIBUTE_PROTOCOL; 668 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL: 669 return L2CAP_CID_SECURITY_MANAGER_PROTOCOL; 670 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL: 671 return L2CAP_CID_CONNECTIONLESS_CHANNEL; 672 default: 673 return 0; 674 } 675 } 676 static int l2cap_fixed_channel_table_index_for_channel_id(uint16_t channel_id){ 677 switch (channel_id){ 678 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 679 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL; 680 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 681 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL; 682 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 683 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL; 684 default: 685 return -1; 686 } 687 } 688 689 static int l2cap_fixed_channel_table_index_is_le(int index){ 690 if (index == L2CAP_CID_CONNECTIONLESS_CHANNEL) return 0; 691 return 1; 692 } 693 694 void l2cap_init(void){ 695 signaling_responses_pending = 0; 696 697 #ifdef ENABLE_CLASSIC 698 l2cap_channels = NULL; 699 l2cap_services = NULL; 700 require_security_level2_for_outgoing_sdp = 0; 701 #endif 702 703 #ifdef ENABLE_LE_DATA_CHANNELS 704 l2cap_le_services = NULL; 705 l2cap_le_channels = NULL; 706 #endif 707 708 #ifdef ENABLE_BLE 709 l2cap_event_packet_handler = NULL; 710 #endif 711 memset(fixed_channels, 0, sizeof(fixed_channels)); 712 713 // 714 // register callback with HCI 715 // 716 hci_event_callback_registration.callback = &l2cap_hci_event_handler; 717 hci_add_event_handler(&hci_event_callback_registration); 718 719 hci_register_acl_packet_handler(&l2cap_acl_handler); 720 721 #ifdef ENABLE_CLASSIC 722 gap_connectable_control(0); // no services yet 723 #endif 724 } 725 726 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 727 #ifdef ENABLE_BLE 728 l2cap_event_packet_handler = handler; 729 #else 730 UNUSED(handler); 731 #endif 732 } 733 734 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ 735 UNUSED(con_handle); 736 737 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 738 if (index < 0) return; 739 fixed_channels[index].waiting_for_can_send_now = 1; 740 l2cap_notify_channel_can_send(); 741 } 742 743 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ 744 UNUSED(channel_id); 745 746 return hci_can_send_acl_packet_now(con_handle); 747 } 748 749 uint8_t *l2cap_get_outgoing_buffer(void){ 750 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 751 } 752 753 int l2cap_reserve_packet_buffer(void){ 754 return hci_reserve_packet_buffer(); 755 } 756 757 void l2cap_release_packet_buffer(void){ 758 hci_release_packet_buffer(); 759 } 760 761 static void l2cap_setup_header(uint8_t * acl_buffer, hci_con_handle_t con_handle, uint8_t packet_boundary, uint16_t remote_cid, uint16_t len){ 762 // 0 - Connection handle : PB=pb : BC=00 763 little_endian_store_16(acl_buffer, 0, con_handle | (packet_boundary << 12) | (0 << 14)); 764 // 2 - ACL length 765 little_endian_store_16(acl_buffer, 2, len + 4); 766 // 4 - L2CAP packet length 767 little_endian_store_16(acl_buffer, 4, len + 0); 768 // 6 - L2CAP channel DEST 769 little_endian_store_16(acl_buffer, 6, remote_cid); 770 } 771 772 // assumption - only on LE connections 773 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 774 775 if (!hci_is_packet_buffer_reserved()){ 776 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 777 return BTSTACK_ACL_BUFFERS_FULL; 778 } 779 780 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 781 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 782 return BTSTACK_ACL_BUFFERS_FULL; 783 } 784 785 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 786 787 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 788 l2cap_setup_header(acl_buffer, con_handle, 0, cid, len); 789 // send 790 return hci_send_acl_packet_buffer(len+8); 791 } 792 793 // assumption - only on LE connections 794 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 795 796 if (!hci_can_send_acl_packet_now(con_handle)){ 797 log_info("l2cap_send cid 0x%02x, cannot send", cid); 798 return BTSTACK_ACL_BUFFERS_FULL; 799 } 800 801 hci_reserve_packet_buffer(); 802 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 803 804 memcpy(&acl_buffer[8], data, len); 805 806 return l2cap_send_prepared_connectionless(con_handle, cid, len); 807 } 808 809 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { 810 log_debug("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); 811 uint8_t event[4]; 812 event[0] = L2CAP_EVENT_CAN_SEND_NOW; 813 event[1] = sizeof(event) - 2; 814 little_endian_store_16(event, 2, channel); 815 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 816 packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); 817 } 818 819 #ifdef L2CAP_USES_CHANNELS 820 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 821 (* (channel->packet_handler))(type, channel->local_cid, data, size); 822 } 823 824 static void l2cap_emit_simple_event_with_cid(l2cap_channel_t * channel, uint8_t event_code){ 825 uint8_t event[4]; 826 event[0] = event_code; 827 event[1] = sizeof(event) - 2; 828 little_endian_store_16(event, 2, channel->local_cid); 829 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 830 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 831 } 832 #endif 833 834 #ifdef ENABLE_CLASSIC 835 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 836 log_info("L2CAP_EVENT_CHANNEL_OPENED status 0x%x addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x local_mtu %u, remote_mtu %u, flush_timeout %u", 837 status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 838 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 839 uint8_t event[24]; 840 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 841 event[1] = sizeof(event) - 2; 842 event[2] = status; 843 reverse_bd_addr(channel->address, &event[3]); 844 little_endian_store_16(event, 9, channel->con_handle); 845 little_endian_store_16(event, 11, channel->psm); 846 little_endian_store_16(event, 13, channel->local_cid); 847 little_endian_store_16(event, 15, channel->remote_cid); 848 little_endian_store_16(event, 17, channel->local_mtu); 849 little_endian_store_16(event, 19, channel->remote_mtu); 850 little_endian_store_16(event, 21, channel->flush_timeout); 851 event[23] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 852 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 853 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 854 } 855 856 static void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 857 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 858 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 859 } 860 861 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel) { 862 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 863 bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); 864 uint8_t event[16]; 865 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 866 event[1] = sizeof(event) - 2; 867 reverse_bd_addr(channel->address, &event[2]); 868 little_endian_store_16(event, 8, channel->con_handle); 869 little_endian_store_16(event, 10, channel->psm); 870 little_endian_store_16(event, 12, channel->local_cid); 871 little_endian_store_16(event, 14, channel->remote_cid); 872 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 873 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 874 } 875 876 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 877 btstack_linked_list_iterator_t it; 878 btstack_linked_list_iterator_init(&it, &l2cap_channels); 879 while (btstack_linked_list_iterator_has_next(&it)){ 880 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 881 if ( channel->local_cid == local_cid) { 882 return channel; 883 } 884 } 885 return NULL; 886 } 887 888 /// 889 890 void l2cap_request_can_send_now_event(uint16_t local_cid){ 891 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 892 if (!channel) return; 893 channel->waiting_for_can_send_now = 1; 894 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 895 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 896 l2cap_ertm_notify_channel_can_send(channel); 897 return; 898 } 899 #endif 900 l2cap_notify_channel_can_send(); 901 } 902 903 int l2cap_can_send_packet_now(uint16_t local_cid){ 904 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 905 if (!channel) return 0; 906 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 907 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 908 return l2cap_ertm_can_store_packet_now(channel); 909 } 910 #endif 911 return hci_can_send_acl_packet_now(channel->con_handle); 912 } 913 914 int l2cap_can_send_prepared_packet_now(uint16_t local_cid){ 915 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 916 if (!channel) return 0; 917 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 918 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 919 return 0; 920 } 921 #endif 922 return hci_can_send_prepared_acl_packet_now(channel->con_handle); 923 } 924 925 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 926 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 927 if (channel) { 928 return channel->remote_mtu; 929 } 930 return 0; 931 } 932 933 static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ 934 btstack_linked_list_iterator_t it; 935 btstack_linked_list_iterator_init(&it, &l2cap_channels); 936 while (btstack_linked_list_iterator_has_next(&it)){ 937 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 938 if ( &channel->rtx == ts) { 939 return channel; 940 } 941 } 942 return NULL; 943 } 944 945 static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ 946 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 947 if (!channel) return; 948 949 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 950 951 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 952 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 953 // notify client 954 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 955 956 // discard channel 957 // no need to stop timer here, it is removed from list during timer callback 958 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 959 btstack_memory_l2cap_channel_free(channel); 960 } 961 962 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 963 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 964 btstack_run_loop_remove_timer(&channel->rtx); 965 } 966 967 static void l2cap_start_rtx(l2cap_channel_t * channel){ 968 l2cap_stop_rtx(channel); 969 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 970 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 971 btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 972 btstack_run_loop_add_timer(&channel->rtx); 973 } 974 975 static void l2cap_start_ertx(l2cap_channel_t * channel){ 976 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 977 l2cap_stop_rtx(channel); 978 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 979 btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 980 btstack_run_loop_add_timer(&channel->rtx); 981 } 982 983 void l2cap_require_security_level_2_for_outgoing_sdp(void){ 984 require_security_level2_for_outgoing_sdp = 1; 985 } 986 987 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 988 return (psm == BLUETOOTH_PROTOCOL_SDP) && (!require_security_level2_for_outgoing_sdp); 989 } 990 991 static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 992 if (!hci_can_send_acl_packet_now(handle)){ 993 log_info("l2cap_send_signaling_packet, cannot send"); 994 return BTSTACK_ACL_BUFFERS_FULL; 995 } 996 997 // log_info("l2cap_send_signaling_packet type %u", cmd); 998 hci_reserve_packet_buffer(); 999 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1000 va_list argptr; 1001 va_start(argptr, identifier); 1002 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 1003 va_end(argptr); 1004 // log_info("l2cap_send_signaling_packet con %u!", handle); 1005 return hci_send_acl_packet_buffer(len); 1006 } 1007 1008 // assumption - only on Classic connections 1009 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 1010 1011 if (!hci_is_packet_buffer_reserved()){ 1012 log_error("l2cap_send_prepared called without reserving packet first"); 1013 return BTSTACK_ACL_BUFFERS_FULL; 1014 } 1015 1016 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1017 if (!channel) { 1018 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 1019 return -1; // TODO: define error 1020 } 1021 1022 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 1023 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 1024 return BTSTACK_ACL_BUFFERS_FULL; 1025 } 1026 1027 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 1028 1029 int fcs_size = 0; 1030 1031 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1032 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1033 fcs_size = 2; 1034 } 1035 #endif 1036 1037 // set non-flushable packet boundary flag if supported on Controller 1038 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1039 uint8_t packet_boundary_flag = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 1040 l2cap_setup_header(acl_buffer, channel->con_handle, packet_boundary_flag, channel->remote_cid, len + fcs_size); 1041 1042 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1043 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1044 // calculate FCS over l2cap data 1045 uint16_t fcs = crc16_calc(acl_buffer + 4, 4 + len); 1046 log_info("I-Frame: fcs 0x%04x", fcs); 1047 little_endian_store_16(acl_buffer, 8 + len, fcs); 1048 } 1049 #endif 1050 1051 // send 1052 return hci_send_acl_packet_buffer(len+8+fcs_size); 1053 } 1054 1055 // assumption - only on Classic connections 1056 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 1057 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1058 if (!channel) { 1059 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 1060 return -1; // TODO: define error 1061 } 1062 1063 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1064 // send in ERTM 1065 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1066 return l2cap_ertm_send(channel, data, len); 1067 } 1068 #endif 1069 1070 if (len > channel->remote_mtu){ 1071 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 1072 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 1073 } 1074 1075 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 1076 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 1077 return BTSTACK_ACL_BUFFERS_FULL; 1078 } 1079 1080 hci_reserve_packet_buffer(); 1081 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1082 memcpy(&acl_buffer[8], data, len); 1083 return l2cap_send_prepared(local_cid, len); 1084 } 1085 1086 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ 1087 return l2cap_send_signaling_packet(con_handle, ECHO_REQUEST, 0x77, len, data); 1088 } 1089 1090 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 1091 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 1092 } 1093 1094 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 1095 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 1096 } 1097 #endif 1098 1099 1100 #ifdef ENABLE_BLE 1101 static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 1102 1103 if (!hci_can_send_acl_packet_now(handle)){ 1104 log_info("l2cap_send_le_signaling_packet, cannot send"); 1105 return BTSTACK_ACL_BUFFERS_FULL; 1106 } 1107 1108 // log_info("l2cap_send_le_signaling_packet type %u", cmd); 1109 hci_reserve_packet_buffer(); 1110 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1111 va_list argptr; 1112 va_start(argptr, identifier); 1113 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 1114 va_end(argptr); 1115 // log_info("l2cap_send_le_signaling_packet con %u!", handle); 1116 return hci_send_acl_packet_buffer(len); 1117 } 1118 #endif 1119 1120 uint16_t l2cap_max_mtu(void){ 1121 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 1122 } 1123 1124 uint16_t l2cap_max_le_mtu(void){ 1125 return l2cap_max_mtu(); 1126 } 1127 1128 #ifdef ENABLE_CLASSIC 1129 1130 static uint16_t l2cap_setup_options_mtu(l2cap_channel_t * channel, uint8_t * config_options){ 1131 config_options[0] = 1; // MTU 1132 config_options[1] = 2; // len param 1133 little_endian_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 1134 return 4; 1135 } 1136 1137 static uint16_t l2cap_setup_options(l2cap_channel_t * channel, uint8_t * config_options){ 1138 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1139 // use ERTM options if supported 1140 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1141 if ((connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_DONE) && (connection->l2cap_state.extended_feature_mask & 0x08)){ 1142 return l2cap_setup_options_ertm(channel, config_options); 1143 1144 } 1145 #endif 1146 return l2cap_setup_options_mtu(channel, config_options); 1147 } 1148 1149 static uint32_t l2cap_extended_features_mask(void){ 1150 // extended features request supported, features: fixed channels, unicast connectionless data reception 1151 uint32_t features = 0x280; 1152 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1153 features |= 0x0008; 1154 #endif 1155 return features; 1156 } 1157 #endif 1158 1159 // MARK: L2CAP_RUN 1160 // process outstanding signaling tasks 1161 static void l2cap_run(void){ 1162 1163 // log_info("l2cap_run: entered"); 1164 1165 // check pending signaling responses 1166 while (signaling_responses_pending){ 1167 1168 hci_con_handle_t handle = signaling_responses[0].handle; 1169 1170 if (!hci_can_send_acl_packet_now(handle)) break; 1171 1172 uint8_t sig_id = signaling_responses[0].sig_id; 1173 uint8_t response_code = signaling_responses[0].code; 1174 uint16_t info_type = signaling_responses[0].data; // INFORMATION_REQUEST 1175 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 1176 #ifdef ENABLE_CLASSIC 1177 uint16_t source_cid = signaling_responses[0].cid; // CONNECTION_REQUEST 1178 #endif 1179 UNUSED(info_type); 1180 1181 // remove first item before sending (to avoid sending response mutliple times) 1182 signaling_responses_pending--; 1183 int i; 1184 for (i=0; i < signaling_responses_pending; i++){ 1185 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 1186 } 1187 1188 switch (response_code){ 1189 #ifdef ENABLE_CLASSIC 1190 case CONNECTION_REQUEST: 1191 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, source_cid, 0, result, 0); 1192 // also disconnect if result is 0x0003 - security blocked 1193 if (result == 0x0003){ 1194 hci_disconnect_security_block(handle); 1195 } 1196 break; 1197 case ECHO_REQUEST: 1198 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 1199 break; 1200 case INFORMATION_REQUEST: 1201 switch (info_type){ 1202 case L2CAP_INFO_TYPE_CONNECTIONLESS_MTU: { 1203 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 1204 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 0, sizeof(connectionless_mtu), &connectionless_mtu); 1205 } 1206 break; 1207 case L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED: { 1208 uint32_t features = l2cap_extended_features_mask(); 1209 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 0, sizeof(features), &features); 1210 } 1211 break; 1212 case L2CAP_INFO_TYPE_FIXED_CHANNELS_SUPPORTED: { 1213 uint8_t map[8]; 1214 memset(map, 0, 8); 1215 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 1216 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 0, sizeof(map), &map); 1217 } 1218 break; 1219 default: 1220 // all other types are not supported 1221 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 1, 0, NULL); 1222 break; 1223 } 1224 break; 1225 case COMMAND_REJECT: 1226 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 1227 break; 1228 #endif 1229 #ifdef ENABLE_BLE 1230 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1231 l2cap_send_le_signaling_packet(handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, sig_id, 0, 0, 0, 0, result); 1232 break; 1233 case COMMAND_REJECT_LE: 1234 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 1235 break; 1236 #endif 1237 default: 1238 // should not happen 1239 break; 1240 } 1241 } 1242 1243 btstack_linked_list_iterator_t it; 1244 UNUSED(it); 1245 1246 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1247 // send l2cap information request if neccessary 1248 hci_connections_get_iterator(&it); 1249 while(btstack_linked_list_iterator_has_next(&it)){ 1250 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1251 if (connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST){ 1252 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W4_EXTENDED_FEATURE_RESPONSE; 1253 // send information request for extended features 1254 uint8_t sig_id = l2cap_next_sig_id(); 1255 uint8_t info_type = L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED; 1256 l2cap_send_signaling_packet(connection->con_handle, INFORMATION_REQUEST, sig_id, info_type); 1257 return; 1258 } 1259 } 1260 #endif 1261 1262 #ifdef ENABLE_CLASSIC 1263 uint8_t config_options[10]; 1264 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1265 while (btstack_linked_list_iterator_has_next(&it)){ 1266 1267 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1268 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 1269 switch (channel->state){ 1270 1271 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1272 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 1273 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1274 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 1275 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 1276 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 1277 } 1278 break; 1279 1280 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1281 if (!hci_can_send_command_packet_now()) break; 1282 // send connection request - set state first 1283 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 1284 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 1285 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 1286 break; 1287 1288 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 1289 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1290 channel->state = L2CAP_STATE_INVALID; 1291 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 1292 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 1293 l2cap_stop_rtx(channel); 1294 btstack_linked_list_iterator_remove(&it); 1295 btstack_memory_l2cap_channel_free(channel); 1296 break; 1297 1298 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 1299 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1300 channel->state = L2CAP_STATE_CONFIG; 1301 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1302 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 1303 break; 1304 1305 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 1306 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1307 // success, start l2cap handshake 1308 channel->local_sig_id = l2cap_next_sig_id(); 1309 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 1310 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 1311 l2cap_start_rtx(channel); 1312 break; 1313 1314 case L2CAP_STATE_CONFIG: 1315 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1316 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 1317 uint16_t flags = 0; 1318 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1319 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 1320 flags = 1; 1321 } else { 1322 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 1323 } 1324 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 1325 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 1326 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 1327 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1328 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED){ 1329 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 1330 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 1331 uint16_t options_size = l2cap_setup_options(channel, config_options); 1332 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS, options_size, &config_options); 1333 #endif 1334 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 1335 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1336 uint16_t options_size = l2cap_setup_options(channel, config_options); 1337 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_SUCCESS, options_size, &config_options); 1338 } else { 1339 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_SUCCESS, 0, NULL); 1340 } 1341 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1342 } 1343 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 1344 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1345 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 1346 channel->local_sig_id = l2cap_next_sig_id(); 1347 uint16_t options_size = l2cap_setup_options(channel, config_options); 1348 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, options_size, &config_options); 1349 l2cap_start_rtx(channel); 1350 } 1351 if (l2cap_channel_ready_for_open(channel)){ 1352 channel->state = L2CAP_STATE_OPEN; 1353 l2cap_emit_channel_opened(channel, 0); // success 1354 } 1355 break; 1356 1357 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 1358 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1359 channel->state = L2CAP_STATE_INVALID; 1360 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 1361 // we don't start an RTX timer for a disconnect - there's no point in closing the channel if the other side doesn't respond :) 1362 l2cap_finialize_channel_close(channel); // -- remove from list 1363 break; 1364 1365 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1366 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1367 channel->local_sig_id = l2cap_next_sig_id(); 1368 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 1369 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 1370 break; 1371 default: 1372 break; 1373 } 1374 1375 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1376 // send s-frame to acknowledge received packets 1377 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1378 1379 if (channel->tx_send_index != channel->tx_write_index){ 1380 // check remote tx window 1381 log_info("unacknowledged_packets %u, remote tx window size %u", channel->unacked_frames, channel->remote_tx_window_size); 1382 if (channel->unacked_frames < channel->remote_tx_window_size){ 1383 channel->unacked_frames++; 1384 int index = channel->tx_send_index; 1385 channel->tx_send_index++; 1386 if (channel->tx_send_index >= channel->num_tx_buffers){ 1387 channel->tx_send_index = 0; 1388 } 1389 l2cap_ertm_send_information_frame(channel, index, 0); // final = 0 1390 continue; 1391 } 1392 } 1393 1394 if (channel->send_supervisor_frame_receiver_ready){ 1395 channel->send_supervisor_frame_receiver_ready = 0; 1396 log_info("Send S-Frame: RR %u, final %u", channel->req_seq, channel->set_final_bit_after_packet_with_poll_bit_set); 1397 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY, 0, channel->set_final_bit_after_packet_with_poll_bit_set, channel->req_seq); 1398 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1399 l2cap_ertm_send_supervisor_frame(channel, control); 1400 continue; 1401 } 1402 if (channel->send_supervisor_frame_receiver_ready_poll){ 1403 channel->send_supervisor_frame_receiver_ready_poll = 0; 1404 log_info("Send S-Frame: RR %u with poll=1 ", channel->req_seq); 1405 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY, 1, 0, channel->req_seq); 1406 l2cap_ertm_send_supervisor_frame(channel, control); 1407 continue; 1408 } 1409 if (channel->send_supervisor_frame_receiver_not_ready){ 1410 channel->send_supervisor_frame_receiver_not_ready = 0; 1411 log_info("Send S-Frame: RNR %u", channel->req_seq); 1412 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY, 0, 0, channel->req_seq); 1413 l2cap_ertm_send_supervisor_frame(channel, control); 1414 continue; 1415 } 1416 if (channel->send_supervisor_frame_reject){ 1417 channel->send_supervisor_frame_reject = 0; 1418 log_info("Send S-Frame: REJ %u", channel->req_seq); 1419 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT, 0, 0, channel->req_seq); 1420 l2cap_ertm_send_supervisor_frame(channel, control); 1421 continue; 1422 } 1423 if (channel->send_supervisor_frame_selective_reject){ 1424 channel->send_supervisor_frame_selective_reject = 0; 1425 log_info("Send S-Frame: SREJ %u", channel->expected_tx_seq); 1426 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT, 0, channel->set_final_bit_after_packet_with_poll_bit_set, channel->expected_tx_seq); 1427 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1428 l2cap_ertm_send_supervisor_frame(channel, control); 1429 continue; 1430 } 1431 1432 if (channel->srej_active){ 1433 int i; 1434 for (i=0;i<channel->num_tx_buffers;i++){ 1435 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[i]; 1436 if (tx_state->retransmission_requested) { 1437 tx_state->retransmission_requested = 0; 1438 uint8_t final = channel->set_final_bit_after_packet_with_poll_bit_set; 1439 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1440 l2cap_ertm_send_information_frame(channel, i, final); 1441 break; 1442 } 1443 } 1444 if (i == channel->num_tx_buffers){ 1445 // no retransmission request found 1446 channel->srej_active = 0; 1447 } else { 1448 // packet was sent 1449 continue; 1450 } 1451 } 1452 #endif 1453 1454 } 1455 #endif 1456 1457 #ifdef ENABLE_LE_DATA_CHANNELS 1458 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1459 while (btstack_linked_list_iterator_has_next(&it)){ 1460 uint8_t * acl_buffer; 1461 uint8_t * l2cap_payload; 1462 uint16_t pos; 1463 uint16_t payload_size; 1464 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1465 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 1466 switch (channel->state){ 1467 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 1468 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1469 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 1470 // le psm, source cid, mtu, mps, initial credits 1471 channel->local_sig_id = l2cap_next_sig_id(); 1472 channel->credits_incoming = channel->new_credits_incoming; 1473 channel->new_credits_incoming = 0; 1474 l2cap_send_le_signaling_packet( channel->con_handle, LE_CREDIT_BASED_CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid, channel->local_mtu, 23, channel->credits_incoming); 1475 break; 1476 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 1477 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1478 // TODO: support larger MPS 1479 channel->state = L2CAP_STATE_OPEN; 1480 channel->credits_incoming = channel->new_credits_incoming; 1481 channel->new_credits_incoming = 0; 1482 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->local_mtu, 23, channel->credits_incoming, 0); 1483 // notify client 1484 l2cap_emit_le_channel_opened(channel, 0); 1485 break; 1486 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 1487 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1488 channel->state = L2CAP_STATE_INVALID; 1489 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); 1490 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 1491 l2cap_stop_rtx(channel); 1492 btstack_linked_list_iterator_remove(&it); 1493 btstack_memory_l2cap_channel_free(channel); 1494 break; 1495 case L2CAP_STATE_OPEN: 1496 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1497 1498 // send credits 1499 if (channel->new_credits_incoming){ 1500 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 1501 channel->local_sig_id = l2cap_next_sig_id(); 1502 uint16_t new_credits = channel->new_credits_incoming; 1503 channel->new_credits_incoming = 0; 1504 channel->credits_incoming += new_credits; 1505 l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); 1506 break; 1507 } 1508 1509 // send data 1510 if (!channel->send_sdu_buffer) break; 1511 if (!channel->credits_outgoing) break; 1512 1513 // send part of SDU 1514 hci_reserve_packet_buffer(); 1515 acl_buffer = hci_get_outgoing_packet_buffer(); 1516 l2cap_payload = acl_buffer + 8; 1517 pos = 0; 1518 if (!channel->send_sdu_pos){ 1519 // store SDU len 1520 channel->send_sdu_pos += 2; 1521 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 1522 pos += 2; 1523 } 1524 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 1525 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); 1526 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 1527 pos += payload_size; 1528 channel->send_sdu_pos += payload_size; 1529 l2cap_setup_header(acl_buffer, channel->con_handle, 0, channel->remote_cid, pos); 1530 // done 1531 1532 channel->credits_outgoing--; 1533 1534 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 1535 channel->send_sdu_buffer = NULL; 1536 // send done event 1537 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_PACKET_SENT); 1538 // inform about can send now 1539 l2cap_le_notify_channel_can_send(channel); 1540 } 1541 hci_send_acl_packet_buffer(8 + pos); 1542 break; 1543 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1544 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1545 channel->local_sig_id = l2cap_next_sig_id(); 1546 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 1547 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 1548 break; 1549 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 1550 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1551 channel->state = L2CAP_STATE_INVALID; 1552 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 1553 l2cap_le_finialize_channel_close(channel); // -- remove from list 1554 break; 1555 default: 1556 break; 1557 } 1558 } 1559 #endif 1560 1561 #ifdef ENABLE_BLE 1562 // send l2cap con paramter update if necessary 1563 hci_connections_get_iterator(&it); 1564 while(btstack_linked_list_iterator_has_next(&it)){ 1565 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1566 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 1567 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 1568 switch (connection->le_con_parameter_update_state){ 1569 case CON_PARAMETER_UPDATE_SEND_REQUEST: 1570 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 1571 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 1572 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 1573 break; 1574 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 1575 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 1576 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 1577 break; 1578 case CON_PARAMETER_UPDATE_DENY: 1579 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 1580 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 1581 break; 1582 default: 1583 break; 1584 } 1585 } 1586 #endif 1587 1588 // log_info("l2cap_run: exit"); 1589 } 1590 1591 #ifdef ENABLE_CLASSIC 1592 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 1593 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 1594 log_info("l2cap_handle_connection_complete expected state"); 1595 // success, start l2cap handshake 1596 channel->con_handle = con_handle; 1597 // check remote SSP feature first 1598 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 1599 } 1600 } 1601 1602 static void l2cap_ready_to_connect(l2cap_channel_t * channel){ 1603 1604 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1605 // assumption: outgoing connection 1606 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1607 if (connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_IDLE){ 1608 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 1609 channel->state = L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES; 1610 return; 1611 } 1612 #endif 1613 1614 // fine, go ahead 1615 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1616 } 1617 1618 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 1619 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 1620 1621 // we have been waiting for remote supported features, if both support SSP, 1622 log_info("l2cap received remote supported features, sec_level_0_allowed for psm %u = %u", channel->psm, l2cap_security_level_0_allowed_for_PSM(channel->psm)); 1623 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 1624 // request security level 2 1625 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 1626 gap_request_security_level(channel->con_handle, LEVEL_2); 1627 return; 1628 } 1629 1630 l2cap_ready_to_connect(channel); 1631 } 1632 #endif 1633 1634 #ifdef L2CAP_USES_CHANNELS 1635 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 1636 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 1637 1638 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 1639 if (!channel) { 1640 return NULL; 1641 } 1642 1643 // Init memory (make valgrind happy) 1644 memset(channel, 0, sizeof(l2cap_channel_t)); 1645 1646 // fill in 1647 channel->packet_handler = packet_handler; 1648 bd_addr_copy(channel->address, address); 1649 channel->address_type = address_type; 1650 channel->psm = psm; 1651 channel->local_mtu = local_mtu; 1652 channel->remote_mtu = L2CAP_MINIMAL_MTU; 1653 channel->required_security_level = security_level; 1654 1655 // 1656 channel->local_cid = l2cap_next_local_cid(); 1657 channel->con_handle = 0; 1658 1659 // set initial state 1660 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 1661 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 1662 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 1663 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 1664 1665 return channel; 1666 } 1667 #endif 1668 1669 #ifdef ENABLE_CLASSIC 1670 1671 /** 1672 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 1673 * @param packet_handler 1674 * @param address 1675 * @param psm 1676 * @param mtu 1677 * @param local_cid 1678 */ 1679 1680 uint8_t l2cap_create_channel(btstack_packet_handler_t channel_packet_handler, bd_addr_t address, uint16_t psm, uint16_t mtu, uint16_t * out_local_cid){ 1681 // limit MTU to the size of our outtgoing HCI buffer 1682 uint16_t local_mtu = btstack_min(mtu, l2cap_max_mtu()); 1683 1684 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u -> local mtu %u", bd_addr_to_str(address), psm, mtu, local_mtu); 1685 1686 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 1687 if (!channel) { 1688 return BTSTACK_MEMORY_ALLOC_FAILED; 1689 } 1690 1691 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1692 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1693 #endif 1694 1695 // add to connections list 1696 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1697 1698 // store local_cid 1699 if (out_local_cid){ 1700 *out_local_cid = channel->local_cid; 1701 } 1702 1703 // check if hci connection is already usable 1704 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 1705 if (conn){ 1706 log_info("l2cap_create_channel, hci connection already exists"); 1707 l2cap_handle_connection_complete(conn->con_handle, channel); 1708 // check if remote supported fearures are already received 1709 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 1710 l2cap_handle_remote_supported_features_received(channel); 1711 } 1712 } 1713 1714 l2cap_run(); 1715 1716 return 0; 1717 } 1718 1719 void 1720 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 1721 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 1722 // find channel for local_cid 1723 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1724 if (channel) { 1725 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1726 } 1727 // process 1728 l2cap_run(); 1729 } 1730 1731 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 1732 btstack_linked_list_iterator_t it; 1733 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1734 while (btstack_linked_list_iterator_has_next(&it)){ 1735 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1736 if ( bd_addr_cmp( channel->address, address) != 0) continue; 1737 // channel for this address found 1738 switch (channel->state){ 1739 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1740 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1741 // failure, forward error code 1742 l2cap_emit_channel_opened(channel, status); 1743 // discard channel 1744 l2cap_stop_rtx(channel); 1745 btstack_linked_list_iterator_remove(&it); 1746 btstack_memory_l2cap_channel_free(channel); 1747 break; 1748 default: 1749 break; 1750 } 1751 } 1752 } 1753 1754 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1755 btstack_linked_list_iterator_t it; 1756 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1757 while (btstack_linked_list_iterator_has_next(&it)){ 1758 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1759 if ( ! bd_addr_cmp( channel->address, address) ){ 1760 l2cap_handle_connection_complete(handle, channel); 1761 } 1762 } 1763 // process 1764 l2cap_run(); 1765 } 1766 #endif 1767 1768 static void l2cap_notify_channel_can_send(void){ 1769 1770 #ifdef ENABLE_CLASSIC 1771 btstack_linked_list_iterator_t it; 1772 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1773 while (btstack_linked_list_iterator_has_next(&it)){ 1774 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1775 if (!channel->waiting_for_can_send_now) continue; 1776 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1777 channel->waiting_for_can_send_now = 0; 1778 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1779 } 1780 #endif 1781 1782 int i; 1783 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1784 if (!fixed_channels[i].callback) continue; 1785 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1786 int can_send = 0; 1787 if (l2cap_fixed_channel_table_index_is_le(i)){ 1788 #ifdef ENABLE_BLE 1789 can_send = hci_can_send_acl_le_packet_now(); 1790 #endif 1791 } else { 1792 #ifdef ENABLE_CLASSIC 1793 can_send = hci_can_send_acl_classic_packet_now(); 1794 #endif 1795 } 1796 if (!can_send) continue; 1797 fixed_channels[i].waiting_for_can_send_now = 0; 1798 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1799 } 1800 } 1801 1802 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1803 1804 UNUSED(packet_type); 1805 UNUSED(cid); 1806 UNUSED(size); 1807 1808 bd_addr_t address; 1809 hci_con_handle_t handle; 1810 int hci_con_used; 1811 btstack_linked_list_iterator_t it; 1812 1813 // avoid unused warnings 1814 UNUSED(address); 1815 UNUSED(hci_con_used); 1816 UNUSED(it); 1817 UNUSED(handle); 1818 1819 switch(hci_event_packet_get_type(packet)){ 1820 1821 // Notify channel packet handler if they can send now 1822 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1823 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1824 l2cap_run(); // try sending signaling packets first 1825 l2cap_notify_channel_can_send(); 1826 break; 1827 1828 case HCI_EVENT_COMMAND_STATUS: 1829 l2cap_run(); // try sending signaling packets first 1830 break; 1831 1832 #ifdef ENABLE_CLASSIC 1833 // handle connection complete events 1834 case HCI_EVENT_CONNECTION_COMPLETE: 1835 reverse_bd_addr(&packet[5], address); 1836 if (packet[2] == 0){ 1837 handle = little_endian_read_16(packet, 3); 1838 l2cap_handle_connection_success_for_addr(address, handle); 1839 } else { 1840 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1841 } 1842 break; 1843 1844 // handle successful create connection cancel command 1845 case HCI_EVENT_COMMAND_COMPLETE: 1846 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1847 if (packet[5] == 0){ 1848 reverse_bd_addr(&packet[6], address); 1849 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1850 l2cap_handle_connection_failed_for_addr(address, 0x16); 1851 } 1852 } 1853 l2cap_run(); // try sending signaling packets first 1854 break; 1855 #endif 1856 1857 // handle disconnection complete events 1858 case HCI_EVENT_DISCONNECTION_COMPLETE: 1859 // send l2cap disconnect events for all channels on this handle and free them 1860 #ifdef ENABLE_CLASSIC 1861 handle = little_endian_read_16(packet, 3); 1862 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1863 while (btstack_linked_list_iterator_has_next(&it)){ 1864 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1865 if (channel->con_handle != handle) continue; 1866 l2cap_emit_channel_closed(channel); 1867 l2cap_stop_rtx(channel); 1868 btstack_linked_list_iterator_remove(&it); 1869 btstack_memory_l2cap_channel_free(channel); 1870 } 1871 #endif 1872 #ifdef ENABLE_LE_DATA_CHANNELS 1873 handle = little_endian_read_16(packet, 3); 1874 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1875 while (btstack_linked_list_iterator_has_next(&it)){ 1876 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1877 if (channel->con_handle != handle) continue; 1878 l2cap_emit_channel_closed(channel); 1879 btstack_linked_list_iterator_remove(&it); 1880 btstack_memory_l2cap_channel_free(channel); 1881 } 1882 #endif 1883 break; 1884 1885 // HCI Connection Timeouts 1886 #ifdef ENABLE_CLASSIC 1887 case L2CAP_EVENT_TIMEOUT_CHECK: 1888 handle = little_endian_read_16(packet, 2); 1889 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1890 if (hci_authentication_active_for_handle(handle)) break; 1891 hci_con_used = 0; 1892 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1893 while (btstack_linked_list_iterator_has_next(&it)){ 1894 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1895 if (channel->con_handle != handle) continue; 1896 hci_con_used = 1; 1897 break; 1898 } 1899 if (hci_con_used) break; 1900 if (!hci_can_send_command_packet_now()) break; 1901 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1902 break; 1903 1904 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1905 handle = little_endian_read_16(packet, 3); 1906 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1907 while (btstack_linked_list_iterator_has_next(&it)){ 1908 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1909 if (channel->con_handle != handle) continue; 1910 l2cap_handle_remote_supported_features_received(channel); 1911 break; 1912 } 1913 break; 1914 1915 case GAP_EVENT_SECURITY_LEVEL: 1916 handle = little_endian_read_16(packet, 2); 1917 log_info("l2cap - security level update"); 1918 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1919 while (btstack_linked_list_iterator_has_next(&it)){ 1920 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1921 if (channel->con_handle != handle) continue; 1922 1923 log_info("l2cap - state %u", channel->state); 1924 1925 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1926 gap_security_level_t required_level = channel->required_security_level; 1927 1928 switch (channel->state){ 1929 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1930 if (actual_level >= required_level){ 1931 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1932 // we need to know if ERTM is supported before sending a config response 1933 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1934 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 1935 channel->state = L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES; 1936 #else 1937 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1938 l2cap_emit_incoming_connection(channel); 1939 #endif 1940 } else { 1941 channel->reason = 0x0003; // security block 1942 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1943 } 1944 break; 1945 1946 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1947 if (actual_level >= required_level){ 1948 l2cap_ready_to_connect(channel); 1949 } else { 1950 // disconnnect, authentication not good enough 1951 hci_disconnect_security_block(handle); 1952 } 1953 break; 1954 1955 default: 1956 break; 1957 } 1958 } 1959 break; 1960 #endif 1961 1962 default: 1963 break; 1964 } 1965 1966 l2cap_run(); 1967 } 1968 1969 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t cid, uint16_t data){ 1970 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1971 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1972 signaling_responses[signaling_responses_pending].handle = handle; 1973 signaling_responses[signaling_responses_pending].code = code; 1974 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1975 signaling_responses[signaling_responses_pending].cid = cid; 1976 signaling_responses[signaling_responses_pending].data = data; 1977 signaling_responses_pending++; 1978 l2cap_run(); 1979 } 1980 } 1981 1982 #ifdef ENABLE_CLASSIC 1983 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1984 channel->remote_sig_id = identifier; 1985 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1986 l2cap_run(); 1987 } 1988 1989 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1990 1991 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1992 l2cap_service_t *service = l2cap_get_service(psm); 1993 if (!service) { 1994 // 0x0002 PSM not supported 1995 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 1996 return; 1997 } 1998 1999 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 2000 if (!hci_connection) { 2001 // 2002 log_error("no hci_connection for handle %u", handle); 2003 return; 2004 } 2005 2006 // alloc structure 2007 // log_info("l2cap_handle_connection_request register channel"); 2008 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 2009 psm, service->mtu, service->required_security_level); 2010 if (!channel){ 2011 // 0x0004 No resources available 2012 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 2013 return; 2014 } 2015 2016 channel->con_handle = handle; 2017 channel->remote_cid = source_cid; 2018 channel->remote_sig_id = sig_id; 2019 2020 // limit local mtu to max acl packet length - l2cap header 2021 if (channel->local_mtu > l2cap_max_mtu()) { 2022 channel->local_mtu = l2cap_max_mtu(); 2023 } 2024 2025 // set initial state 2026 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 2027 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND | L2CAP_CHANNEL_STATE_VAR_INCOMING); 2028 2029 // add to connections list 2030 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 2031 2032 // assert security requirements 2033 gap_request_security_level(handle, channel->required_security_level); 2034 } 2035 2036 void l2cap_accept_connection(uint16_t local_cid){ 2037 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 2038 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 2039 if (!channel) { 2040 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 2041 return; 2042 } 2043 2044 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2045 // configure L2CAP Basic mode 2046 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2047 #endif 2048 2049 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 2050 2051 // process 2052 l2cap_run(); 2053 } 2054 2055 void l2cap_decline_connection(uint16_t local_cid){ 2056 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 2057 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 2058 if (!channel) { 2059 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 2060 return; 2061 } 2062 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 2063 channel->reason = 0x04; // no resources available 2064 l2cap_run(); 2065 } 2066 2067 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 2068 2069 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2070 2071 uint16_t flags = little_endian_read_16(command, 6); 2072 if (flags & 1) { 2073 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 2074 } 2075 2076 // accept the other's configuration options 2077 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2078 uint16_t pos = 8; 2079 while (pos < end_pos){ 2080 uint8_t option_hint = command[pos] >> 7; 2081 uint8_t option_type = command[pos] & 0x7f; 2082 // log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 2083 pos++; 2084 uint8_t length = command[pos++]; 2085 // MTU { type(8): 1, len(8):2, MTU(16) } 2086 if (option_type == L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT && length == 2){ 2087 channel->remote_mtu = little_endian_read_16(command, pos); 2088 log_info("Remote MTU %u", channel->remote_mtu); 2089 if (channel->remote_mtu > l2cap_max_mtu()){ 2090 log_info("Remote MTU %u larger than outgoing buffer, only using MTU = %u", channel->remote_mtu, l2cap_max_mtu()); 2091 channel->remote_mtu = l2cap_max_mtu(); 2092 } 2093 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 2094 } 2095 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 2096 if (option_type == L2CAP_CONFIG_OPTION_TYPE_FLUSH_TIMEOUT && length == 2){ 2097 channel->flush_timeout = little_endian_read_16(command, pos); 2098 log_info("Flush timeout: %u ms", channel->flush_timeout); 2099 } 2100 2101 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2102 // Retransmission and Flow Control Option 2103 if (option_type == L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL && length == 9){ 2104 l2cap_channel_mode_t mode = (l2cap_channel_mode_t) command[pos]; 2105 switch(channel->mode){ 2106 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 2107 // Store remote config 2108 channel->remote_tx_window_size = command[pos+1]; 2109 channel->remote_max_transmit = command[pos+2]; 2110 channel->remote_retransmission_timeout_ms = little_endian_read_16(command, pos + 3); 2111 channel->remote_monitor_timeout_ms = little_endian_read_16(command, pos + 5); 2112 channel->remote_mps = little_endian_read_16(command, pos + 7); 2113 log_info("FC&C config: tx window: %u, max transmit %u, retrans timeout %u, monitor timeout %u, mps %u", 2114 channel->remote_tx_window_size, 2115 channel->remote_max_transmit, 2116 channel->remote_retransmission_timeout_ms, 2117 channel->remote_monitor_timeout_ms, 2118 channel->remote_mps); 2119 // If ERTM mandatory, but remote doens't offer ERTM -> disconnect 2120 if (channel->ertm_mandatory && mode != L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 2121 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2122 } else { 2123 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 2124 } 2125 break; 2126 case L2CAP_CHANNEL_MODE_BASIC: 2127 switch (mode){ 2128 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 2129 // remote asks for ERTM, but we want basic mode. disconnect if this happens a second time 2130 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED){ 2131 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2132 } 2133 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED); 2134 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 2135 break; 2136 default: // case L2CAP_CHANNEL_MODE_BASIC: 2137 // TODO store and evaluate configuration 2138 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 2139 break; 2140 } 2141 break; 2142 default: 2143 break; 2144 } 2145 } 2146 #endif 2147 // check for unknown options 2148 if (option_hint == 0 && (option_type < L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT || option_type > L2CAP_CONFIG_OPTION_TYPE_EXTENDED_WINDOW_SIZE)){ 2149 log_info("l2cap cid %u, unknown options", channel->local_cid); 2150 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 2151 } 2152 pos += length; 2153 } 2154 } 2155 2156 static void l2cap_signaling_handle_configure_response(l2cap_channel_t *channel, uint8_t result, uint8_t *command){ 2157 log_info("l2cap_signaling_handle_configure_response"); 2158 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2159 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2160 uint16_t pos = 10; 2161 while (pos < end_pos){ 2162 uint8_t option_hint = command[pos] >> 7; 2163 uint8_t option_type = command[pos] & 0x7f; 2164 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 2165 pos++; 2166 uint8_t length = command[pos++]; 2167 2168 // Retransmission and Flow Control Option 2169 if (option_type == L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL && length == 9){ 2170 switch (channel->mode){ 2171 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 2172 if (channel->ertm_mandatory){ 2173 // ?? 2174 } else { 2175 // On 'Reject - Unacceptable Parameters' to our optional ERTM request, fall back to BASIC mode 2176 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 2177 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2178 } 2179 } 2180 break; 2181 case L2CAP_CHANNEL_MODE_BASIC: 2182 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 2183 // On 'Reject - Unacceptable Parameters' to our Basic mode request, disconnect 2184 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2185 } 2186 break; 2187 default: 2188 break; 2189 } 2190 } 2191 2192 // check for unknown options 2193 if (option_hint == 0 && (option_type < L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT || option_type > L2CAP_CONFIG_OPTION_TYPE_EXTENDED_WINDOW_SIZE)){ 2194 log_info("l2cap cid %u, unknown options", channel->local_cid); 2195 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 2196 } 2197 2198 pos += length; 2199 } 2200 #else 2201 UNUSED(channel); 2202 UNUSED(result); 2203 UNUSED(command); 2204 #endif 2205 } 2206 2207 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 2208 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 2209 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 2210 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 2211 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 2212 if (channel->state == L2CAP_STATE_OPEN) return 0; 2213 return 1; 2214 } 2215 2216 2217 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 2218 2219 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2220 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2221 uint16_t result = 0; 2222 2223 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 2224 2225 // handle DISCONNECT REQUESTS seperately 2226 if (code == DISCONNECTION_REQUEST){ 2227 switch (channel->state){ 2228 case L2CAP_STATE_CONFIG: 2229 case L2CAP_STATE_OPEN: 2230 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 2231 case L2CAP_STATE_WAIT_DISCONNECT: 2232 l2cap_handle_disconnect_request(channel, identifier); 2233 break; 2234 2235 default: 2236 // ignore in other states 2237 break; 2238 } 2239 return; 2240 } 2241 2242 // @STATEMACHINE(l2cap) 2243 switch (channel->state) { 2244 2245 case L2CAP_STATE_WAIT_CONNECT_RSP: 2246 switch (code){ 2247 case CONNECTION_RESPONSE: 2248 l2cap_stop_rtx(channel); 2249 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2250 switch (result) { 2251 case 0: 2252 // successful connection 2253 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2254 channel->state = L2CAP_STATE_CONFIG; 2255 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 2256 break; 2257 case 1: 2258 // connection pending. get some coffee, but start the ERTX 2259 l2cap_start_ertx(channel); 2260 break; 2261 default: 2262 // channel closed 2263 channel->state = L2CAP_STATE_CLOSED; 2264 // map l2cap connection response result to BTstack status enumeration 2265 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 2266 2267 // drop link key if security block 2268 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 2269 gap_drop_link_key_for_bd_addr(channel->address); 2270 } 2271 2272 // discard channel 2273 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2274 btstack_memory_l2cap_channel_free(channel); 2275 break; 2276 } 2277 break; 2278 2279 default: 2280 //@TODO: implement other signaling packets 2281 break; 2282 } 2283 break; 2284 2285 case L2CAP_STATE_CONFIG: 2286 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2287 switch (code) { 2288 case CONFIGURE_REQUEST: 2289 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 2290 l2cap_signaling_handle_configure_request(channel, command); 2291 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 2292 // only done if continuation not set 2293 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 2294 } 2295 break; 2296 case CONFIGURE_RESPONSE: 2297 l2cap_stop_rtx(channel); 2298 l2cap_signaling_handle_configure_response(channel, result, command); 2299 switch (result){ 2300 case 0: // success 2301 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 2302 break; 2303 case 4: // pending 2304 l2cap_start_ertx(channel); 2305 break; 2306 default: 2307 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2308 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION && channel->ertm_mandatory){ 2309 // remote does not offer ertm but it's required 2310 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2311 break; 2312 } 2313 #endif 2314 // retry on negative result 2315 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 2316 break; 2317 } 2318 break; 2319 default: 2320 break; 2321 } 2322 if (l2cap_channel_ready_for_open(channel)){ 2323 // for open: 2324 channel->state = L2CAP_STATE_OPEN; 2325 l2cap_emit_channel_opened(channel, 0); 2326 } 2327 break; 2328 2329 case L2CAP_STATE_WAIT_DISCONNECT: 2330 switch (code) { 2331 case DISCONNECTION_RESPONSE: 2332 l2cap_finialize_channel_close(channel); 2333 break; 2334 default: 2335 //@TODO: implement other signaling packets 2336 break; 2337 } 2338 break; 2339 2340 case L2CAP_STATE_CLOSED: 2341 // @TODO handle incoming requests 2342 break; 2343 2344 case L2CAP_STATE_OPEN: 2345 //@TODO: implement other signaling packets, e.g. re-configure 2346 break; 2347 default: 2348 break; 2349 } 2350 // log_info("new state %u", channel->state); 2351 } 2352 2353 2354 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 2355 2356 btstack_linked_list_iterator_t it; 2357 2358 // get code, signalind identifier and command len 2359 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2360 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2361 2362 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_RESPONSE 2363 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_RESPONSE){ 2364 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2365 return; 2366 } 2367 2368 // general commands without an assigned channel 2369 switch(code) { 2370 2371 case CONNECTION_REQUEST: { 2372 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2373 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2374 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 2375 return; 2376 } 2377 2378 case ECHO_REQUEST: 2379 l2cap_register_signaling_response(handle, code, sig_id, 0, 0); 2380 return; 2381 2382 case INFORMATION_REQUEST: { 2383 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2384 l2cap_register_signaling_response(handle, code, sig_id, 0, info_type); 2385 return; 2386 } 2387 2388 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2389 case INFORMATION_RESPONSE: { 2390 hci_connection_t * connection = hci_connection_for_handle(handle); 2391 if (!connection) return; 2392 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2393 uint16_t result = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2394 if (result != 0) return; 2395 if (info_type != L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED) return; 2396 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_DONE; 2397 connection->l2cap_state.extended_feature_mask = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2398 log_info("extended features mask 0x%02x", connection->l2cap_state.extended_feature_mask); 2399 // trigger connection request 2400 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2401 while (btstack_linked_list_iterator_has_next(&it)){ 2402 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2403 if (channel->con_handle != handle) continue; 2404 // bail if ERTM was requested but is not supported 2405 if ((channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION) && ((connection->l2cap_state.extended_feature_mask & 0x08) == 0)){ 2406 if (channel->ertm_mandatory){ 2407 // channel closed 2408 channel->state = L2CAP_STATE_CLOSED; 2409 // map l2cap connection response result to BTstack status enumeration 2410 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_ERTM_NOT_SUPPORTD); 2411 // discard channel 2412 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2413 btstack_memory_l2cap_channel_free(channel); 2414 continue; 2415 } else { 2416 // fallback to Basic mode 2417 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2418 } 2419 } 2420 // start connecting 2421 if (channel->state == L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES){ 2422 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 2423 } 2424 // respond to connection request 2425 if (channel->state == L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES){ 2426 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2427 l2cap_emit_incoming_connection(channel); 2428 } 2429 } 2430 return; 2431 } 2432 #endif 2433 2434 default: 2435 break; 2436 } 2437 2438 2439 // Get potential destination CID 2440 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2441 2442 // Find channel for this sig_id and connection handle 2443 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2444 while (btstack_linked_list_iterator_has_next(&it)){ 2445 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2446 if (channel->con_handle != handle) continue; 2447 if (code & 1) { 2448 // match odd commands (responses) by previous signaling identifier 2449 if (channel->local_sig_id == sig_id) { 2450 l2cap_signaling_handler_channel(channel, command); 2451 break; 2452 } 2453 } else { 2454 // match even commands (requests) by local channel id 2455 if (channel->local_cid == dest_cid) { 2456 l2cap_signaling_handler_channel(channel, command); 2457 break; 2458 } 2459 } 2460 } 2461 } 2462 #endif 2463 2464 #ifdef ENABLE_BLE 2465 2466 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 2467 uint8_t event[6]; 2468 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 2469 event[1] = 4; 2470 little_endian_store_16(event, 2, con_handle); 2471 little_endian_store_16(event, 4, result); 2472 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2473 if (!l2cap_event_packet_handler) return; 2474 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 2475 } 2476 2477 // @returns valid 2478 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 2479 hci_connection_t * connection; 2480 uint16_t result; 2481 uint8_t event[10]; 2482 2483 #ifdef ENABLE_LE_DATA_CHANNELS 2484 btstack_linked_list_iterator_t it; 2485 l2cap_channel_t * channel; 2486 uint16_t local_cid; 2487 uint16_t le_psm; 2488 uint16_t new_credits; 2489 uint16_t credits_before; 2490 l2cap_service_t * service; 2491 uint16_t source_cid; 2492 #endif 2493 2494 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2495 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 2496 2497 switch (code){ 2498 2499 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 2500 result = little_endian_read_16(command, 4); 2501 l2cap_emit_connection_parameter_update_response(handle, result); 2502 break; 2503 2504 case CONNECTION_PARAMETER_UPDATE_REQUEST: 2505 connection = hci_connection_for_handle(handle); 2506 if (connection){ 2507 if (connection->role != HCI_ROLE_MASTER){ 2508 // reject command without notifying upper layer when not in master role 2509 return 0; 2510 } 2511 int update_parameter = 1; 2512 le_connection_parameter_range_t existing_range; 2513 gap_get_connection_parameter_range(&existing_range); 2514 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 2515 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 2516 uint16_t le_conn_latency = little_endian_read_16(command,12); 2517 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 2518 2519 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 2520 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 2521 2522 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 2523 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 2524 2525 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 2526 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 2527 2528 if (update_parameter){ 2529 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 2530 connection->le_conn_interval_min = le_conn_interval_min; 2531 connection->le_conn_interval_max = le_conn_interval_max; 2532 connection->le_conn_latency = le_conn_latency; 2533 connection->le_supervision_timeout = le_supervision_timeout; 2534 } else { 2535 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 2536 } 2537 connection->le_con_param_update_identifier = sig_id; 2538 } 2539 2540 if (!l2cap_event_packet_handler) break; 2541 2542 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 2543 event[1] = 8; 2544 memcpy(&event[2], &command[4], 8); 2545 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2546 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2547 break; 2548 2549 #ifdef ENABLE_LE_DATA_CHANNELS 2550 2551 case COMMAND_REJECT: 2552 // Find channel for this sig_id and connection handle 2553 channel = NULL; 2554 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2555 while (btstack_linked_list_iterator_has_next(&it)){ 2556 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2557 if (a_channel->con_handle != handle) continue; 2558 if (a_channel->local_sig_id != sig_id) continue; 2559 channel = a_channel; 2560 break; 2561 } 2562 if (!channel) break; 2563 2564 // if received while waiting for le connection response, assume legacy device 2565 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 2566 channel->state = L2CAP_STATE_CLOSED; 2567 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 2568 l2cap_emit_le_channel_opened(channel, 0x0002); 2569 2570 // discard channel 2571 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2572 btstack_memory_l2cap_channel_free(channel); 2573 break; 2574 } 2575 break; 2576 2577 case LE_CREDIT_BASED_CONNECTION_REQUEST: 2578 2579 // get hci connection, bail if not found (must not happen) 2580 connection = hci_connection_for_handle(handle); 2581 if (!connection) return 0; 2582 2583 // check if service registered 2584 le_psm = little_endian_read_16(command, 4); 2585 service = l2cap_le_get_service(le_psm); 2586 source_cid = little_endian_read_16(command, 6); 2587 2588 if (service){ 2589 if (source_cid < 0x40){ 2590 // 0x0009 Connection refused - Invalid Source CID 2591 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0009); 2592 return 1; 2593 } 2594 2595 // go through list of channels for this ACL connection and check if we get a match 2596 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2597 while (btstack_linked_list_iterator_has_next(&it)){ 2598 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2599 if (a_channel->con_handle != handle) continue; 2600 if (a_channel->remote_cid != source_cid) continue; 2601 // 0x000a Connection refused - Source CID already allocated 2602 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x000a); 2603 return 1; 2604 } 2605 2606 // security: check encryption 2607 if (service->required_security_level >= LEVEL_2){ 2608 if (sm_encryption_key_size(handle) == 0){ 2609 // 0x0008 Connection refused - insufficient encryption 2610 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0008); 2611 return 1; 2612 } 2613 // anything less than 16 byte key size is insufficient 2614 if (sm_encryption_key_size(handle) < 16){ 2615 // 0x0007 Connection refused – insufficient encryption key size 2616 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0007); 2617 return 1; 2618 } 2619 } 2620 2621 // security: check authencation 2622 if (service->required_security_level >= LEVEL_3){ 2623 if (!sm_authenticated(handle)){ 2624 // 0x0005 Connection refused – insufficient authentication 2625 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0005); 2626 return 1; 2627 } 2628 } 2629 2630 // security: check authorization 2631 if (service->required_security_level >= LEVEL_4){ 2632 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 2633 // 0x0006 Connection refused – insufficient authorization 2634 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0006); 2635 return 1; 2636 } 2637 } 2638 2639 // allocate channel 2640 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 2641 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 2642 if (!channel){ 2643 // 0x0004 Connection refused – no resources available 2644 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 2645 return 1; 2646 } 2647 2648 channel->con_handle = handle; 2649 channel->remote_cid = source_cid; 2650 channel->remote_sig_id = sig_id; 2651 channel->remote_mtu = little_endian_read_16(command, 8); 2652 channel->remote_mps = little_endian_read_16(command, 10); 2653 channel->credits_outgoing = little_endian_read_16(command, 12); 2654 2655 // set initial state 2656 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2657 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 2658 2659 // add to connections list 2660 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2661 2662 // post connection request event 2663 l2cap_emit_le_incoming_connection(channel); 2664 2665 } else { 2666 // Connection refused – LE_PSM not supported 2667 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 2668 } 2669 break; 2670 2671 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 2672 // Find channel for this sig_id and connection handle 2673 channel = NULL; 2674 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2675 while (btstack_linked_list_iterator_has_next(&it)){ 2676 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2677 if (a_channel->con_handle != handle) continue; 2678 if (a_channel->local_sig_id != sig_id) continue; 2679 channel = a_channel; 2680 break; 2681 } 2682 if (!channel) break; 2683 2684 // cid + 0 2685 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 2686 if (result){ 2687 channel->state = L2CAP_STATE_CLOSED; 2688 // map l2cap connection response result to BTstack status enumeration 2689 l2cap_emit_le_channel_opened(channel, result); 2690 2691 // discard channel 2692 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2693 btstack_memory_l2cap_channel_free(channel); 2694 break; 2695 } 2696 2697 // success 2698 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2699 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2700 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 2701 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 2702 channel->state = L2CAP_STATE_OPEN; 2703 l2cap_emit_le_channel_opened(channel, result); 2704 break; 2705 2706 case LE_FLOW_CONTROL_CREDIT: 2707 // find channel 2708 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2709 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2710 if (!channel) { 2711 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2712 break; 2713 } 2714 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2715 credits_before = channel->credits_outgoing; 2716 channel->credits_outgoing += new_credits; 2717 // check for credit overrun 2718 if (credits_before > channel->credits_outgoing){ 2719 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 2720 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2721 break; 2722 } 2723 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 2724 break; 2725 2726 case DISCONNECTION_REQUEST: 2727 // find channel 2728 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2729 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2730 if (!channel) { 2731 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2732 break; 2733 } 2734 channel->remote_sig_id = sig_id; 2735 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 2736 break; 2737 2738 #endif 2739 2740 case DISCONNECTION_RESPONSE: 2741 break; 2742 2743 default: 2744 // command unknown -> reject command 2745 return 0; 2746 } 2747 return 1; 2748 } 2749 #endif 2750 2751 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 2752 UNUSED(packet_type); 2753 UNUSED(channel); 2754 2755 l2cap_channel_t * l2cap_channel; 2756 UNUSED(l2cap_channel); 2757 2758 // Get Channel ID 2759 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 2760 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 2761 2762 switch (channel_id) { 2763 2764 #ifdef ENABLE_CLASSIC 2765 case L2CAP_CID_SIGNALING: { 2766 uint16_t command_offset = 8; 2767 while (command_offset < size) { 2768 // handle signaling commands 2769 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 2770 2771 // increment command_offset 2772 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2773 } 2774 break; 2775 } 2776 #endif 2777 2778 #ifdef ENABLE_BLE 2779 case L2CAP_CID_SIGNALING_LE: { 2780 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 2781 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 2782 if (!valid){ 2783 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2784 } 2785 break; 2786 } 2787 #endif 2788 2789 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 2790 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 2791 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2792 } 2793 break; 2794 2795 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 2796 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 2797 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2798 } 2799 break; 2800 2801 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 2802 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 2803 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2804 } 2805 break; 2806 2807 default: 2808 #ifdef ENABLE_CLASSIC 2809 // Find channel for this channel_id and connection handle 2810 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 2811 if (l2cap_channel) { 2812 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2813 if (l2cap_channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 2814 2815 // verify FCS 2816 uint16_t fcs_calculated = crc16_calc(&packet[4], size - (4+2)); 2817 uint16_t fcs_packet = little_endian_read_16(packet, size-2); 2818 log_info("Packet FCS 0x%04x, calculated FCS 0x%04x", fcs_packet, fcs_calculated); 2819 if (fcs_calculated != fcs_packet){ 2820 log_error("FCS mismatch! Packet 0x%04x, calculated 0x%04x", fcs_packet, fcs_calculated); 2821 // TODO: trigger retransmission or something like that 2822 break; 2823 } 2824 2825 // switch on packet type 2826 uint16_t control = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 2827 uint8_t req_seq = (control >> 8) & 0x3f; 2828 int final = (control >> 7) & 0x01; 2829 if (control & 1){ 2830 // S-Frame 2831 int poll = (control >> 4) & 0x01; 2832 l2cap_supervisory_function_t s = (l2cap_supervisory_function_t) ((control >> 2) & 0x03); 2833 log_info("Control: 0x%04x => Supervisory function %u, ReqSeq %02u", control, (int) s, req_seq); 2834 l2cap_ertm_tx_packet_state_t * tx_state; 2835 switch (s){ 2836 case L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY: 2837 log_info("L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY"); 2838 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 2839 if (poll && final){ 2840 // S-frames shall not be transmitted with both the F-bit and the P-bit set to 1 at the same time. 2841 log_error("P=F=1 in S-Frame"); 2842 break; 2843 } 2844 if (poll){ 2845 // check if we did request selective retransmission before <==> we have stored SDU segments 2846 int i; 2847 int num_stored_out_of_order_packets = 0; 2848 for (i=0;i<l2cap_channel->num_rx_buffers;i++){ 2849 int index = l2cap_channel->rx_store_index + i; 2850 if (index >= l2cap_channel->num_rx_buffers){ 2851 index -= l2cap_channel->num_rx_buffers; 2852 } 2853 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 2854 if (!rx_state->valid) continue; 2855 num_stored_out_of_order_packets++; 2856 } 2857 if (num_stored_out_of_order_packets){ 2858 l2cap_channel->send_supervisor_frame_selective_reject = 1; 2859 } else { 2860 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 2861 } 2862 l2cap_channel->set_final_bit_after_packet_with_poll_bit_set = 1; 2863 } 2864 if (final){ 2865 // Stop-MonitorTimer 2866 l2cap_ertm_stop_monitor_timer(l2cap_channel); 2867 // If UnackedFrames > 0 then Start-RetransTimer 2868 if (l2cap_channel->unacked_frames){ 2869 l2cap_ertm_start_retransmission_timer(l2cap_channel); 2870 } 2871 2872 // final bit set <- response to RR with poll bit set. All not acknowledged packets need to be retransmitted 2873 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 2874 } 2875 break; 2876 case L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT: 2877 log_info("L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT"); 2878 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 2879 // rsetart transmittion from last unacknowledted packet (earlier packets already freed in l2cap_ertm_process_req_seq) 2880 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 2881 break; 2882 case L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY: 2883 log_error("L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY"); 2884 break; 2885 case L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT: 2886 log_info("L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT"); 2887 if (poll){ 2888 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 2889 } 2890 // find requested i-frame 2891 tx_state = l2cap_ertm_get_tx_state(l2cap_channel, req_seq); 2892 if (tx_state){ 2893 log_info("Retransmission for tx_seq %u requested", req_seq); 2894 l2cap_channel->set_final_bit_after_packet_with_poll_bit_set = poll; 2895 tx_state->retransmission_requested = 1; 2896 l2cap_channel->srej_active = 1; 2897 } 2898 break; 2899 default: 2900 break; 2901 } 2902 break; 2903 } else { 2904 // I-Frame 2905 // get control 2906 l2cap_segmentation_and_reassembly_t sar = (l2cap_segmentation_and_reassembly_t) (control >> 14); 2907 uint8_t tx_seq = (control >> 1) & 0x3f; 2908 log_info("Control: 0x%04x => SAR %u, ReqSeq %02u, R?, TxSeq %02u", control, (int) sar, req_seq, tx_seq); 2909 log_info("SAR: pos %u", l2cap_channel->reassembly_pos); 2910 log_info("State: expected_tx_seq %02u, req_seq %02u", l2cap_channel->expected_tx_seq, l2cap_channel->req_seq); 2911 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 2912 if (final){ 2913 // final bit set <- response to RR with poll bit set. All not acknowledged packets need to be retransmitted 2914 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 2915 } 2916 // check ordering 2917 if (l2cap_channel->expected_tx_seq == tx_seq){ 2918 log_info("Received expected frame with TxSeq == ExpectedTxSeq == %02u", tx_seq); 2919 l2cap_channel->expected_tx_seq = l2cap_next_ertm_seq_nr(l2cap_channel->expected_tx_seq); 2920 l2cap_channel->req_seq = l2cap_channel->expected_tx_seq; 2921 2922 // process SDU 2923 l2cap_ertm_handle_in_sequence_sdu(l2cap_channel, sar, &packet[COMPLETE_L2CAP_HEADER+2], size-(COMPLETE_L2CAP_HEADER+2+2)); 2924 2925 // process stored segments 2926 while (1){ 2927 int index = l2cap_channel->rx_store_index; 2928 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 2929 if (!rx_state->valid) break; 2930 2931 log_info("Processing stored frame with TxSeq == ExpectedTxSeq == %02u", l2cap_channel->expected_tx_seq); 2932 l2cap_channel->expected_tx_seq = l2cap_next_ertm_seq_nr(l2cap_channel->expected_tx_seq); 2933 l2cap_channel->req_seq = l2cap_channel->expected_tx_seq; 2934 2935 rx_state->valid = 0; 2936 l2cap_ertm_handle_in_sequence_sdu(l2cap_channel, rx_state->sar, &l2cap_channel->rx_packets_data[index], rx_state->len); 2937 2938 // update rx store index 2939 index++; 2940 if (index >= l2cap_channel->num_rx_buffers){ 2941 index = 0; 2942 } 2943 l2cap_channel->rx_store_index = index; 2944 } 2945 2946 // 2947 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 2948 2949 } else { 2950 int delta = (tx_seq - l2cap_channel->expected_tx_seq) & 0x3f; 2951 if (delta < 2){ 2952 // store segment 2953 l2cap_ertm_handle_out_of_sequence_sdu(l2cap_channel, sar, delta, &packet[COMPLETE_L2CAP_HEADER+2], size-(COMPLETE_L2CAP_HEADER+2+2)); 2954 2955 log_info("Received unexpected frame TxSeq %u but expected %u -> send S-SREJ", tx_seq, l2cap_channel->expected_tx_seq); 2956 l2cap_channel->send_supervisor_frame_selective_reject = 1; 2957 } else { 2958 log_info("Received unexpected frame TxSeq %u but expected %u -> send S-REJ", tx_seq, l2cap_channel->expected_tx_seq); 2959 l2cap_channel->send_supervisor_frame_reject = 1; 2960 } 2961 } 2962 } 2963 break; 2964 } 2965 #endif 2966 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2967 } 2968 #endif 2969 #ifdef ENABLE_LE_DATA_CHANNELS 2970 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 2971 if (l2cap_channel) { 2972 // credit counting 2973 if (l2cap_channel->credits_incoming == 0){ 2974 log_error("LE Data Channel packet received but no incoming credits"); 2975 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2976 break; 2977 } 2978 l2cap_channel->credits_incoming--; 2979 2980 // automatic credits 2981 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 2982 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 2983 } 2984 2985 // first fragment 2986 uint16_t pos = 0; 2987 if (!l2cap_channel->receive_sdu_len){ 2988 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 2989 l2cap_channel->receive_sdu_pos = 0; 2990 pos += 2; 2991 size -= 2; 2992 } 2993 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 2994 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 2995 // done? 2996 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 2997 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 2998 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 2999 l2cap_channel->receive_sdu_len = 0; 3000 } 3001 } else { 3002 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 3003 } 3004 #endif 3005 break; 3006 } 3007 3008 l2cap_run(); 3009 } 3010 3011 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 3012 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 3013 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 3014 if (index < 0) return; 3015 fixed_channels[index].callback = the_packet_handler; 3016 } 3017 3018 #ifdef ENABLE_CLASSIC 3019 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 3020 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 3021 channel->state = L2CAP_STATE_CLOSED; 3022 l2cap_emit_channel_closed(channel); 3023 // discard channel 3024 l2cap_stop_rtx(channel); 3025 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 3026 btstack_memory_l2cap_channel_free(channel); 3027 } 3028 3029 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 3030 btstack_linked_list_iterator_t it; 3031 btstack_linked_list_iterator_init(&it, services); 3032 while (btstack_linked_list_iterator_has_next(&it)){ 3033 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 3034 if ( service->psm == psm){ 3035 return service; 3036 }; 3037 } 3038 return NULL; 3039 } 3040 3041 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 3042 return l2cap_get_service_internal(&l2cap_services, psm); 3043 } 3044 3045 3046 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 3047 3048 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 3049 3050 // check for alread registered psm 3051 l2cap_service_t *service = l2cap_get_service(psm); 3052 if (service) { 3053 log_error("l2cap_register_service: PSM %u already registered", psm); 3054 return L2CAP_SERVICE_ALREADY_REGISTERED; 3055 } 3056 3057 // alloc structure 3058 service = btstack_memory_l2cap_service_get(); 3059 if (!service) { 3060 log_error("l2cap_register_service: no memory for l2cap_service_t"); 3061 return BTSTACK_MEMORY_ALLOC_FAILED; 3062 } 3063 3064 // fill in 3065 service->psm = psm; 3066 service->mtu = mtu; 3067 service->packet_handler = service_packet_handler; 3068 service->required_security_level = security_level; 3069 3070 // add to services list 3071 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 3072 3073 // enable page scan 3074 gap_connectable_control(1); 3075 3076 return 0; 3077 } 3078 3079 uint8_t l2cap_unregister_service(uint16_t psm){ 3080 3081 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 3082 3083 l2cap_service_t *service = l2cap_get_service(psm); 3084 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 3085 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 3086 btstack_memory_l2cap_service_free(service); 3087 3088 // disable page scan when no services registered 3089 if (btstack_linked_list_empty(&l2cap_services)) { 3090 gap_connectable_control(0); 3091 } 3092 return 0; 3093 } 3094 #endif 3095 3096 3097 #ifdef ENABLE_LE_DATA_CHANNELS 3098 3099 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 3100 if (!channel->waiting_for_can_send_now) return; 3101 if (channel->send_sdu_buffer) return; 3102 channel->waiting_for_can_send_now = 0; 3103 log_info("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 3104 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 3105 } 3106 3107 // 1BH2222 3108 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 3109 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", 3110 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 3111 uint8_t event[19]; 3112 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 3113 event[1] = sizeof(event) - 2; 3114 event[2] = channel->address_type; 3115 reverse_bd_addr(channel->address, &event[3]); 3116 little_endian_store_16(event, 9, channel->con_handle); 3117 little_endian_store_16(event, 11, channel->psm); 3118 little_endian_store_16(event, 13, channel->local_cid); 3119 little_endian_store_16(event, 15, channel->remote_cid); 3120 little_endian_store_16(event, 17, channel->remote_mtu); 3121 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 3122 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 3123 } 3124 // 11BH22222 3125 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 3126 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", 3127 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 3128 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 3129 uint8_t event[23]; 3130 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 3131 event[1] = sizeof(event) - 2; 3132 event[2] = status; 3133 event[3] = channel->address_type; 3134 reverse_bd_addr(channel->address, &event[4]); 3135 little_endian_store_16(event, 10, channel->con_handle); 3136 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 3137 little_endian_store_16(event, 13, channel->psm); 3138 little_endian_store_16(event, 15, channel->local_cid); 3139 little_endian_store_16(event, 17, channel->remote_cid); 3140 little_endian_store_16(event, 19, channel->local_mtu); 3141 little_endian_store_16(event, 21, channel->remote_mtu); 3142 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 3143 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 3144 } 3145 3146 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 3147 btstack_linked_list_iterator_t it; 3148 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 3149 while (btstack_linked_list_iterator_has_next(&it)){ 3150 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 3151 if ( channel->local_cid == local_cid) { 3152 return channel; 3153 } 3154 } 3155 return NULL; 3156 } 3157 3158 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 3159 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 3160 channel->state = L2CAP_STATE_CLOSED; 3161 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 3162 // discard channel 3163 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 3164 btstack_memory_l2cap_channel_free(channel); 3165 } 3166 3167 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 3168 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 3169 } 3170 3171 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 3172 3173 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 3174 3175 // check for alread registered psm 3176 l2cap_service_t *service = l2cap_le_get_service(psm); 3177 if (service) { 3178 return L2CAP_SERVICE_ALREADY_REGISTERED; 3179 } 3180 3181 // alloc structure 3182 service = btstack_memory_l2cap_service_get(); 3183 if (!service) { 3184 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 3185 return BTSTACK_MEMORY_ALLOC_FAILED; 3186 } 3187 3188 // fill in 3189 service->psm = psm; 3190 service->mtu = 0; 3191 service->packet_handler = packet_handler; 3192 service->required_security_level = security_level; 3193 3194 // add to services list 3195 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 3196 3197 // done 3198 return 0; 3199 } 3200 3201 uint8_t l2cap_le_unregister_service(uint16_t psm) { 3202 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 3203 l2cap_service_t *service = l2cap_le_get_service(psm); 3204 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 3205 3206 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 3207 btstack_memory_l2cap_service_free(service); 3208 return 0; 3209 } 3210 3211 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 3212 // get channel 3213 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3214 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3215 3216 // validate state 3217 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 3218 return ERROR_CODE_COMMAND_DISALLOWED; 3219 } 3220 3221 // set state accept connection 3222 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 3223 channel->receive_sdu_buffer = receive_sdu_buffer; 3224 channel->local_mtu = mtu; 3225 channel->new_credits_incoming = initial_credits; 3226 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 3227 3228 // test 3229 // channel->new_credits_incoming = 1; 3230 3231 // go 3232 l2cap_run(); 3233 return 0; 3234 } 3235 3236 /** 3237 * @brief Deny incoming LE Data Channel connection due to resource constraints 3238 * @param local_cid L2CAP LE Data Channel Identifier 3239 */ 3240 3241 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 3242 // get channel 3243 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3244 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3245 3246 // validate state 3247 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 3248 return ERROR_CODE_COMMAND_DISALLOWED; 3249 } 3250 3251 // set state decline connection 3252 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 3253 channel->reason = 0x04; // no resources available 3254 l2cap_run(); 3255 return 0; 3256 } 3257 3258 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 3259 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 3260 uint16_t * out_local_cid) { 3261 3262 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 3263 3264 3265 hci_connection_t * connection = hci_connection_for_handle(con_handle); 3266 if (!connection) { 3267 log_error("no hci_connection for handle 0x%04x", con_handle); 3268 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 3269 } 3270 3271 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 3272 if (!channel) { 3273 return BTSTACK_MEMORY_ALLOC_FAILED; 3274 } 3275 log_info("l2cap_le_create_channel %p", channel); 3276 3277 // store local_cid 3278 if (out_local_cid){ 3279 *out_local_cid = channel->local_cid; 3280 } 3281 3282 // provide buffer 3283 channel->con_handle = con_handle; 3284 channel->receive_sdu_buffer = receive_sdu_buffer; 3285 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 3286 channel->new_credits_incoming = initial_credits; 3287 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 3288 3289 // add to connections list 3290 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 3291 3292 // go 3293 l2cap_run(); 3294 return 0; 3295 } 3296 3297 /** 3298 * @brief Provide credtis for LE Data Channel 3299 * @param local_cid L2CAP LE Data Channel Identifier 3300 * @param credits Number additional credits for peer 3301 */ 3302 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 3303 3304 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3305 if (!channel) { 3306 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 3307 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3308 } 3309 3310 // check state 3311 if (channel->state != L2CAP_STATE_OPEN){ 3312 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 3313 } 3314 3315 // assert incoming credits + credits <= 0xffff 3316 uint32_t total_credits = channel->credits_incoming; 3317 total_credits += channel->new_credits_incoming; 3318 total_credits += credits; 3319 if (total_credits > 0xffff){ 3320 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 3321 channel->new_credits_incoming, credits); 3322 } 3323 3324 // set credits_granted 3325 channel->new_credits_incoming += credits; 3326 3327 // go 3328 l2cap_run(); 3329 return 0; 3330 } 3331 3332 /** 3333 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 3334 * @param local_cid L2CAP LE Data Channel Identifier 3335 */ 3336 int l2cap_le_can_send_now(uint16_t local_cid){ 3337 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3338 if (!channel) { 3339 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 3340 return 0; 3341 } 3342 3343 // check state 3344 if (channel->state != L2CAP_STATE_OPEN) return 0; 3345 3346 // check queue 3347 if (channel->send_sdu_buffer) return 0; 3348 3349 // fine, go ahead 3350 return 1; 3351 } 3352 3353 /** 3354 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 3355 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 3356 * so packet handler should be ready to handle it 3357 * @param local_cid L2CAP LE Data Channel Identifier 3358 */ 3359 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 3360 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3361 if (!channel) { 3362 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 3363 return 0; 3364 } 3365 channel->waiting_for_can_send_now = 1; 3366 l2cap_le_notify_channel_can_send(channel); 3367 return 0; 3368 } 3369 3370 /** 3371 * @brief Send data via LE Data Channel 3372 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 3373 * @param local_cid L2CAP LE Data Channel Identifier 3374 * @param data data to send 3375 * @param size data size 3376 */ 3377 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 3378 3379 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3380 if (!channel) { 3381 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 3382 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3383 } 3384 3385 if (len > channel->remote_mtu){ 3386 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 3387 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 3388 } 3389 3390 if (channel->send_sdu_buffer){ 3391 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 3392 return BTSTACK_ACL_BUFFERS_FULL; 3393 } 3394 3395 channel->send_sdu_buffer = data; 3396 channel->send_sdu_len = len; 3397 channel->send_sdu_pos = 0; 3398 3399 l2cap_run(); 3400 return 0; 3401 } 3402 3403 /** 3404 * @brief Disconnect from LE Data Channel 3405 * @param local_cid L2CAP LE Data Channel Identifier 3406 */ 3407 uint8_t l2cap_le_disconnect(uint16_t local_cid) 3408 { 3409 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3410 if (!channel) { 3411 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 3412 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3413 } 3414 3415 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3416 l2cap_run(); 3417 return 0; 3418 } 3419 3420 #endif 3421