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 #endif 2201 } 2202 2203 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 2204 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 2205 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 2206 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 2207 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 2208 if (channel->state == L2CAP_STATE_OPEN) return 0; 2209 return 1; 2210 } 2211 2212 2213 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 2214 2215 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2216 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2217 uint16_t result = 0; 2218 2219 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 2220 2221 // handle DISCONNECT REQUESTS seperately 2222 if (code == DISCONNECTION_REQUEST){ 2223 switch (channel->state){ 2224 case L2CAP_STATE_CONFIG: 2225 case L2CAP_STATE_OPEN: 2226 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 2227 case L2CAP_STATE_WAIT_DISCONNECT: 2228 l2cap_handle_disconnect_request(channel, identifier); 2229 break; 2230 2231 default: 2232 // ignore in other states 2233 break; 2234 } 2235 return; 2236 } 2237 2238 // @STATEMACHINE(l2cap) 2239 switch (channel->state) { 2240 2241 case L2CAP_STATE_WAIT_CONNECT_RSP: 2242 switch (code){ 2243 case CONNECTION_RESPONSE: 2244 l2cap_stop_rtx(channel); 2245 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2246 switch (result) { 2247 case 0: 2248 // successful connection 2249 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2250 channel->state = L2CAP_STATE_CONFIG; 2251 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 2252 break; 2253 case 1: 2254 // connection pending. get some coffee, but start the ERTX 2255 l2cap_start_ertx(channel); 2256 break; 2257 default: 2258 // channel closed 2259 channel->state = L2CAP_STATE_CLOSED; 2260 // map l2cap connection response result to BTstack status enumeration 2261 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 2262 2263 // drop link key if security block 2264 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 2265 gap_drop_link_key_for_bd_addr(channel->address); 2266 } 2267 2268 // discard channel 2269 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2270 btstack_memory_l2cap_channel_free(channel); 2271 break; 2272 } 2273 break; 2274 2275 default: 2276 //@TODO: implement other signaling packets 2277 break; 2278 } 2279 break; 2280 2281 case L2CAP_STATE_CONFIG: 2282 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2283 switch (code) { 2284 case CONFIGURE_REQUEST: 2285 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 2286 l2cap_signaling_handle_configure_request(channel, command); 2287 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 2288 // only done if continuation not set 2289 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 2290 } 2291 break; 2292 case CONFIGURE_RESPONSE: 2293 l2cap_stop_rtx(channel); 2294 l2cap_signaling_handle_configure_response(channel, result, command); 2295 switch (result){ 2296 case 0: // success 2297 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 2298 break; 2299 case 4: // pending 2300 l2cap_start_ertx(channel); 2301 break; 2302 default: 2303 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2304 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION && channel->ertm_mandatory){ 2305 // remote does not offer ertm but it's required 2306 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2307 break; 2308 } 2309 #endif 2310 // retry on negative result 2311 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 2312 break; 2313 } 2314 break; 2315 default: 2316 break; 2317 } 2318 if (l2cap_channel_ready_for_open(channel)){ 2319 // for open: 2320 channel->state = L2CAP_STATE_OPEN; 2321 l2cap_emit_channel_opened(channel, 0); 2322 } 2323 break; 2324 2325 case L2CAP_STATE_WAIT_DISCONNECT: 2326 switch (code) { 2327 case DISCONNECTION_RESPONSE: 2328 l2cap_finialize_channel_close(channel); 2329 break; 2330 default: 2331 //@TODO: implement other signaling packets 2332 break; 2333 } 2334 break; 2335 2336 case L2CAP_STATE_CLOSED: 2337 // @TODO handle incoming requests 2338 break; 2339 2340 case L2CAP_STATE_OPEN: 2341 //@TODO: implement other signaling packets, e.g. re-configure 2342 break; 2343 default: 2344 break; 2345 } 2346 // log_info("new state %u", channel->state); 2347 } 2348 2349 2350 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 2351 2352 btstack_linked_list_iterator_t it; 2353 2354 // get code, signalind identifier and command len 2355 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2356 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2357 2358 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_RESPONSE 2359 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_RESPONSE){ 2360 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2361 return; 2362 } 2363 2364 // general commands without an assigned channel 2365 switch(code) { 2366 2367 case CONNECTION_REQUEST: { 2368 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2369 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2370 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 2371 return; 2372 } 2373 2374 case ECHO_REQUEST: 2375 l2cap_register_signaling_response(handle, code, sig_id, 0, 0); 2376 return; 2377 2378 case INFORMATION_REQUEST: { 2379 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2380 l2cap_register_signaling_response(handle, code, sig_id, 0, info_type); 2381 return; 2382 } 2383 2384 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2385 case INFORMATION_RESPONSE: { 2386 hci_connection_t * connection = hci_connection_for_handle(handle); 2387 if (!connection) return; 2388 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2389 uint16_t result = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2390 if (result != 0) return; 2391 if (info_type != L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED) return; 2392 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_DONE; 2393 connection->l2cap_state.extended_feature_mask = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2394 log_info("extended features mask 0x%02x", connection->l2cap_state.extended_feature_mask); 2395 // trigger connection request 2396 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2397 while (btstack_linked_list_iterator_has_next(&it)){ 2398 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2399 if (channel->con_handle != handle) continue; 2400 // bail if ERTM was requested but is not supported 2401 if ((channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION) && ((connection->l2cap_state.extended_feature_mask & 0x08) == 0)){ 2402 if (channel->ertm_mandatory){ 2403 // channel closed 2404 channel->state = L2CAP_STATE_CLOSED; 2405 // map l2cap connection response result to BTstack status enumeration 2406 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_ERTM_NOT_SUPPORTD); 2407 // discard channel 2408 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2409 btstack_memory_l2cap_channel_free(channel); 2410 continue; 2411 } else { 2412 // fallback to Basic mode 2413 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2414 } 2415 } 2416 // start connecting 2417 if (channel->state == L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES){ 2418 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 2419 } 2420 // respond to connection request 2421 if (channel->state == L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES){ 2422 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2423 l2cap_emit_incoming_connection(channel); 2424 } 2425 } 2426 return; 2427 } 2428 #endif 2429 2430 default: 2431 break; 2432 } 2433 2434 2435 // Get potential destination CID 2436 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2437 2438 // Find channel for this sig_id and connection handle 2439 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2440 while (btstack_linked_list_iterator_has_next(&it)){ 2441 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2442 if (channel->con_handle != handle) continue; 2443 if (code & 1) { 2444 // match odd commands (responses) by previous signaling identifier 2445 if (channel->local_sig_id == sig_id) { 2446 l2cap_signaling_handler_channel(channel, command); 2447 break; 2448 } 2449 } else { 2450 // match even commands (requests) by local channel id 2451 if (channel->local_cid == dest_cid) { 2452 l2cap_signaling_handler_channel(channel, command); 2453 break; 2454 } 2455 } 2456 } 2457 } 2458 #endif 2459 2460 #ifdef ENABLE_BLE 2461 2462 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 2463 uint8_t event[6]; 2464 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 2465 event[1] = 4; 2466 little_endian_store_16(event, 2, con_handle); 2467 little_endian_store_16(event, 4, result); 2468 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2469 if (!l2cap_event_packet_handler) return; 2470 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 2471 } 2472 2473 // @returns valid 2474 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 2475 hci_connection_t * connection; 2476 uint16_t result; 2477 uint8_t event[10]; 2478 2479 #ifdef ENABLE_LE_DATA_CHANNELS 2480 btstack_linked_list_iterator_t it; 2481 l2cap_channel_t * channel; 2482 uint16_t local_cid; 2483 uint16_t le_psm; 2484 uint16_t new_credits; 2485 uint16_t credits_before; 2486 l2cap_service_t * service; 2487 uint16_t source_cid; 2488 #endif 2489 2490 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2491 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 2492 2493 switch (code){ 2494 2495 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 2496 result = little_endian_read_16(command, 4); 2497 l2cap_emit_connection_parameter_update_response(handle, result); 2498 break; 2499 2500 case CONNECTION_PARAMETER_UPDATE_REQUEST: 2501 connection = hci_connection_for_handle(handle); 2502 if (connection){ 2503 if (connection->role != HCI_ROLE_MASTER){ 2504 // reject command without notifying upper layer when not in master role 2505 return 0; 2506 } 2507 int update_parameter = 1; 2508 le_connection_parameter_range_t existing_range; 2509 gap_get_connection_parameter_range(&existing_range); 2510 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 2511 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 2512 uint16_t le_conn_latency = little_endian_read_16(command,12); 2513 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 2514 2515 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 2516 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 2517 2518 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 2519 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 2520 2521 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 2522 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 2523 2524 if (update_parameter){ 2525 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 2526 connection->le_conn_interval_min = le_conn_interval_min; 2527 connection->le_conn_interval_max = le_conn_interval_max; 2528 connection->le_conn_latency = le_conn_latency; 2529 connection->le_supervision_timeout = le_supervision_timeout; 2530 } else { 2531 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 2532 } 2533 connection->le_con_param_update_identifier = sig_id; 2534 } 2535 2536 if (!l2cap_event_packet_handler) break; 2537 2538 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 2539 event[1] = 8; 2540 memcpy(&event[2], &command[4], 8); 2541 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2542 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2543 break; 2544 2545 #ifdef ENABLE_LE_DATA_CHANNELS 2546 2547 case COMMAND_REJECT: 2548 // Find channel for this sig_id and connection handle 2549 channel = NULL; 2550 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2551 while (btstack_linked_list_iterator_has_next(&it)){ 2552 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2553 if (a_channel->con_handle != handle) continue; 2554 if (a_channel->local_sig_id != sig_id) continue; 2555 channel = a_channel; 2556 break; 2557 } 2558 if (!channel) break; 2559 2560 // if received while waiting for le connection response, assume legacy device 2561 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 2562 channel->state = L2CAP_STATE_CLOSED; 2563 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 2564 l2cap_emit_le_channel_opened(channel, 0x0002); 2565 2566 // discard channel 2567 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2568 btstack_memory_l2cap_channel_free(channel); 2569 break; 2570 } 2571 break; 2572 2573 case LE_CREDIT_BASED_CONNECTION_REQUEST: 2574 2575 // get hci connection, bail if not found (must not happen) 2576 connection = hci_connection_for_handle(handle); 2577 if (!connection) return 0; 2578 2579 // check if service registered 2580 le_psm = little_endian_read_16(command, 4); 2581 service = l2cap_le_get_service(le_psm); 2582 source_cid = little_endian_read_16(command, 6); 2583 2584 if (service){ 2585 if (source_cid < 0x40){ 2586 // 0x0009 Connection refused - Invalid Source CID 2587 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0009); 2588 return 1; 2589 } 2590 2591 // go through list of channels for this ACL connection and check if we get a match 2592 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2593 while (btstack_linked_list_iterator_has_next(&it)){ 2594 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2595 if (a_channel->con_handle != handle) continue; 2596 if (a_channel->remote_cid != source_cid) continue; 2597 // 0x000a Connection refused - Source CID already allocated 2598 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x000a); 2599 return 1; 2600 } 2601 2602 // security: check encryption 2603 if (service->required_security_level >= LEVEL_2){ 2604 if (sm_encryption_key_size(handle) == 0){ 2605 // 0x0008 Connection refused - insufficient encryption 2606 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0008); 2607 return 1; 2608 } 2609 // anything less than 16 byte key size is insufficient 2610 if (sm_encryption_key_size(handle) < 16){ 2611 // 0x0007 Connection refused – insufficient encryption key size 2612 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0007); 2613 return 1; 2614 } 2615 } 2616 2617 // security: check authencation 2618 if (service->required_security_level >= LEVEL_3){ 2619 if (!sm_authenticated(handle)){ 2620 // 0x0005 Connection refused – insufficient authentication 2621 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0005); 2622 return 1; 2623 } 2624 } 2625 2626 // security: check authorization 2627 if (service->required_security_level >= LEVEL_4){ 2628 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 2629 // 0x0006 Connection refused – insufficient authorization 2630 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0006); 2631 return 1; 2632 } 2633 } 2634 2635 // allocate channel 2636 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 2637 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 2638 if (!channel){ 2639 // 0x0004 Connection refused – no resources available 2640 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 2641 return 1; 2642 } 2643 2644 channel->con_handle = handle; 2645 channel->remote_cid = source_cid; 2646 channel->remote_sig_id = sig_id; 2647 channel->remote_mtu = little_endian_read_16(command, 8); 2648 channel->remote_mps = little_endian_read_16(command, 10); 2649 channel->credits_outgoing = little_endian_read_16(command, 12); 2650 2651 // set initial state 2652 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2653 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 2654 2655 // add to connections list 2656 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2657 2658 // post connection request event 2659 l2cap_emit_le_incoming_connection(channel); 2660 2661 } else { 2662 // Connection refused – LE_PSM not supported 2663 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 2664 } 2665 break; 2666 2667 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 2668 // Find channel for this sig_id and connection handle 2669 channel = NULL; 2670 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2671 while (btstack_linked_list_iterator_has_next(&it)){ 2672 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2673 if (a_channel->con_handle != handle) continue; 2674 if (a_channel->local_sig_id != sig_id) continue; 2675 channel = a_channel; 2676 break; 2677 } 2678 if (!channel) break; 2679 2680 // cid + 0 2681 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 2682 if (result){ 2683 channel->state = L2CAP_STATE_CLOSED; 2684 // map l2cap connection response result to BTstack status enumeration 2685 l2cap_emit_le_channel_opened(channel, result); 2686 2687 // discard channel 2688 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2689 btstack_memory_l2cap_channel_free(channel); 2690 break; 2691 } 2692 2693 // success 2694 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2695 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2696 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 2697 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 2698 channel->state = L2CAP_STATE_OPEN; 2699 l2cap_emit_le_channel_opened(channel, result); 2700 break; 2701 2702 case LE_FLOW_CONTROL_CREDIT: 2703 // find channel 2704 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2705 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2706 if (!channel) { 2707 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2708 break; 2709 } 2710 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2711 credits_before = channel->credits_outgoing; 2712 channel->credits_outgoing += new_credits; 2713 // check for credit overrun 2714 if (credits_before > channel->credits_outgoing){ 2715 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 2716 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2717 break; 2718 } 2719 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 2720 break; 2721 2722 case DISCONNECTION_REQUEST: 2723 // find channel 2724 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2725 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2726 if (!channel) { 2727 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2728 break; 2729 } 2730 channel->remote_sig_id = sig_id; 2731 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 2732 break; 2733 2734 #endif 2735 2736 case DISCONNECTION_RESPONSE: 2737 break; 2738 2739 default: 2740 // command unknown -> reject command 2741 return 0; 2742 } 2743 return 1; 2744 } 2745 #endif 2746 2747 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 2748 UNUSED(packet_type); 2749 UNUSED(channel); 2750 2751 l2cap_channel_t * l2cap_channel; 2752 UNUSED(l2cap_channel); 2753 2754 // Get Channel ID 2755 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 2756 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 2757 2758 switch (channel_id) { 2759 2760 #ifdef ENABLE_CLASSIC 2761 case L2CAP_CID_SIGNALING: { 2762 uint16_t command_offset = 8; 2763 while (command_offset < size) { 2764 // handle signaling commands 2765 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 2766 2767 // increment command_offset 2768 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2769 } 2770 break; 2771 } 2772 #endif 2773 2774 #ifdef ENABLE_BLE 2775 case L2CAP_CID_SIGNALING_LE: { 2776 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 2777 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 2778 if (!valid){ 2779 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2780 } 2781 break; 2782 } 2783 #endif 2784 2785 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 2786 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 2787 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2788 } 2789 break; 2790 2791 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 2792 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 2793 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2794 } 2795 break; 2796 2797 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 2798 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 2799 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2800 } 2801 break; 2802 2803 default: 2804 #ifdef ENABLE_CLASSIC 2805 // Find channel for this channel_id and connection handle 2806 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 2807 if (l2cap_channel) { 2808 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2809 if (l2cap_channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 2810 2811 // verify FCS 2812 uint16_t fcs_calculated = crc16_calc(&packet[4], size - (4+2)); 2813 uint16_t fcs_packet = little_endian_read_16(packet, size-2); 2814 log_info("Packet FCS 0x%04x, calculated FCS 0x%04x", fcs_packet, fcs_calculated); 2815 if (fcs_calculated != fcs_packet){ 2816 log_error("FCS mismatch! Packet 0x%04x, calculated 0x%04x", fcs_packet, fcs_calculated); 2817 // TODO: trigger retransmission or something like that 2818 break; 2819 } 2820 2821 // switch on packet type 2822 uint16_t control = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 2823 uint8_t req_seq = (control >> 8) & 0x3f; 2824 int final = (control >> 7) & 0x01; 2825 if (control & 1){ 2826 // S-Frame 2827 int poll = (control >> 4) & 0x01; 2828 l2cap_supervisory_function_t s = (l2cap_supervisory_function_t) ((control >> 2) & 0x03); 2829 log_info("Control: 0x%04x => Supervisory function %u, ReqSeq %02u", control, (int) s, req_seq); 2830 l2cap_ertm_tx_packet_state_t * tx_state; 2831 switch (s){ 2832 case L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY: 2833 log_info("L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY"); 2834 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 2835 if (poll && final){ 2836 // S-frames shall not be transmitted with both the F-bit and the P-bit set to 1 at the same time. 2837 log_error("P=F=1 in S-Frame"); 2838 break; 2839 } 2840 if (poll){ 2841 // check if we did request selective retransmission before <==> we have stored SDU segments 2842 int i; 2843 int num_stored_out_of_order_packets = 0; 2844 for (i=0;i<l2cap_channel->num_rx_buffers;i++){ 2845 int index = l2cap_channel->rx_store_index + i; 2846 if (index >= l2cap_channel->num_rx_buffers){ 2847 index -= l2cap_channel->num_rx_buffers; 2848 } 2849 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 2850 if (!rx_state->valid) continue; 2851 num_stored_out_of_order_packets++; 2852 } 2853 if (num_stored_out_of_order_packets){ 2854 l2cap_channel->send_supervisor_frame_selective_reject = 1; 2855 } else { 2856 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 2857 } 2858 l2cap_channel->set_final_bit_after_packet_with_poll_bit_set = 1; 2859 } 2860 if (final){ 2861 // Stop-MonitorTimer 2862 l2cap_ertm_stop_monitor_timer(l2cap_channel); 2863 // If UnackedFrames > 0 then Start-RetransTimer 2864 if (l2cap_channel->unacked_frames){ 2865 l2cap_ertm_start_retransmission_timer(l2cap_channel); 2866 } 2867 2868 // final bit set <- response to RR with poll bit set. All not acknowledged packets need to be retransmitted 2869 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 2870 } 2871 break; 2872 case L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT: 2873 log_info("L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT"); 2874 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 2875 // rsetart transmittion from last unacknowledted packet (earlier packets already freed in l2cap_ertm_process_req_seq) 2876 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 2877 break; 2878 case L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY: 2879 log_error("L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY"); 2880 break; 2881 case L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT: 2882 log_info("L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT"); 2883 if (poll){ 2884 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 2885 } 2886 // find requested i-frame 2887 tx_state = l2cap_ertm_get_tx_state(l2cap_channel, req_seq); 2888 if (tx_state){ 2889 log_info("Retransmission for tx_seq %u requested", req_seq); 2890 l2cap_channel->set_final_bit_after_packet_with_poll_bit_set = poll; 2891 tx_state->retransmission_requested = 1; 2892 l2cap_channel->srej_active = 1; 2893 } 2894 break; 2895 default: 2896 break; 2897 } 2898 break; 2899 } else { 2900 // I-Frame 2901 // get control 2902 l2cap_segmentation_and_reassembly_t sar = (l2cap_segmentation_and_reassembly_t) (control >> 14); 2903 uint8_t tx_seq = (control >> 1) & 0x3f; 2904 log_info("Control: 0x%04x => SAR %u, ReqSeq %02u, R?, TxSeq %02u", control, (int) sar, req_seq, tx_seq); 2905 log_info("SAR: pos %u", l2cap_channel->reassembly_pos); 2906 log_info("State: expected_tx_seq %02u, req_seq %02u", l2cap_channel->expected_tx_seq, l2cap_channel->req_seq); 2907 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 2908 if (final){ 2909 // final bit set <- response to RR with poll bit set. All not acknowledged packets need to be retransmitted 2910 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 2911 } 2912 // check ordering 2913 if (l2cap_channel->expected_tx_seq == tx_seq){ 2914 log_info("Received expected frame with TxSeq == ExpectedTxSeq == %02u", tx_seq); 2915 l2cap_channel->expected_tx_seq = l2cap_next_ertm_seq_nr(l2cap_channel->expected_tx_seq); 2916 l2cap_channel->req_seq = l2cap_channel->expected_tx_seq; 2917 2918 // process SDU 2919 l2cap_ertm_handle_in_sequence_sdu(l2cap_channel, sar, &packet[COMPLETE_L2CAP_HEADER+2], size-(COMPLETE_L2CAP_HEADER+2+2)); 2920 2921 // process stored segments 2922 while (1){ 2923 int index = l2cap_channel->rx_store_index; 2924 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 2925 if (!rx_state->valid) break; 2926 2927 log_info("Processing stored frame with TxSeq == ExpectedTxSeq == %02u", l2cap_channel->expected_tx_seq); 2928 l2cap_channel->expected_tx_seq = l2cap_next_ertm_seq_nr(l2cap_channel->expected_tx_seq); 2929 l2cap_channel->req_seq = l2cap_channel->expected_tx_seq; 2930 2931 rx_state->valid = 0; 2932 l2cap_ertm_handle_in_sequence_sdu(l2cap_channel, rx_state->sar, &l2cap_channel->rx_packets_data[index], rx_state->len); 2933 2934 // update rx store index 2935 index++; 2936 if (index >= l2cap_channel->num_rx_buffers){ 2937 index = 0; 2938 } 2939 l2cap_channel->rx_store_index = index; 2940 } 2941 2942 // 2943 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 2944 2945 } else { 2946 int delta = (tx_seq - l2cap_channel->expected_tx_seq) & 0x3f; 2947 if (delta < 2){ 2948 // store segment 2949 l2cap_ertm_handle_out_of_sequence_sdu(l2cap_channel, sar, delta, &packet[COMPLETE_L2CAP_HEADER+2], size-(COMPLETE_L2CAP_HEADER+2+2)); 2950 2951 log_info("Received unexpected frame TxSeq %u but expected %u -> send S-SREJ", tx_seq, l2cap_channel->expected_tx_seq); 2952 l2cap_channel->send_supervisor_frame_selective_reject = 1; 2953 } else { 2954 log_info("Received unexpected frame TxSeq %u but expected %u -> send S-REJ", tx_seq, l2cap_channel->expected_tx_seq); 2955 l2cap_channel->send_supervisor_frame_reject = 1; 2956 } 2957 } 2958 } 2959 break; 2960 } 2961 #endif 2962 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2963 } 2964 #endif 2965 #ifdef ENABLE_LE_DATA_CHANNELS 2966 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 2967 if (l2cap_channel) { 2968 // credit counting 2969 if (l2cap_channel->credits_incoming == 0){ 2970 log_error("LE Data Channel packet received but no incoming credits"); 2971 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2972 break; 2973 } 2974 l2cap_channel->credits_incoming--; 2975 2976 // automatic credits 2977 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 2978 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 2979 } 2980 2981 // first fragment 2982 uint16_t pos = 0; 2983 if (!l2cap_channel->receive_sdu_len){ 2984 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 2985 l2cap_channel->receive_sdu_pos = 0; 2986 pos += 2; 2987 size -= 2; 2988 } 2989 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 2990 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 2991 // done? 2992 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 2993 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 2994 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 2995 l2cap_channel->receive_sdu_len = 0; 2996 } 2997 } else { 2998 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 2999 } 3000 #endif 3001 break; 3002 } 3003 3004 l2cap_run(); 3005 } 3006 3007 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 3008 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 3009 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 3010 if (index < 0) return; 3011 fixed_channels[index].callback = the_packet_handler; 3012 } 3013 3014 #ifdef ENABLE_CLASSIC 3015 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 3016 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 3017 channel->state = L2CAP_STATE_CLOSED; 3018 l2cap_emit_channel_closed(channel); 3019 // discard channel 3020 l2cap_stop_rtx(channel); 3021 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 3022 btstack_memory_l2cap_channel_free(channel); 3023 } 3024 3025 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 3026 btstack_linked_list_iterator_t it; 3027 btstack_linked_list_iterator_init(&it, services); 3028 while (btstack_linked_list_iterator_has_next(&it)){ 3029 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 3030 if ( service->psm == psm){ 3031 return service; 3032 }; 3033 } 3034 return NULL; 3035 } 3036 3037 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 3038 return l2cap_get_service_internal(&l2cap_services, psm); 3039 } 3040 3041 3042 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 3043 3044 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 3045 3046 // check for alread registered psm 3047 l2cap_service_t *service = l2cap_get_service(psm); 3048 if (service) { 3049 log_error("l2cap_register_service: PSM %u already registered", psm); 3050 return L2CAP_SERVICE_ALREADY_REGISTERED; 3051 } 3052 3053 // alloc structure 3054 service = btstack_memory_l2cap_service_get(); 3055 if (!service) { 3056 log_error("l2cap_register_service: no memory for l2cap_service_t"); 3057 return BTSTACK_MEMORY_ALLOC_FAILED; 3058 } 3059 3060 // fill in 3061 service->psm = psm; 3062 service->mtu = mtu; 3063 service->packet_handler = service_packet_handler; 3064 service->required_security_level = security_level; 3065 3066 // add to services list 3067 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 3068 3069 // enable page scan 3070 gap_connectable_control(1); 3071 3072 return 0; 3073 } 3074 3075 uint8_t l2cap_unregister_service(uint16_t psm){ 3076 3077 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 3078 3079 l2cap_service_t *service = l2cap_get_service(psm); 3080 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 3081 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 3082 btstack_memory_l2cap_service_free(service); 3083 3084 // disable page scan when no services registered 3085 if (btstack_linked_list_empty(&l2cap_services)) { 3086 gap_connectable_control(0); 3087 } 3088 return 0; 3089 } 3090 #endif 3091 3092 3093 #ifdef ENABLE_LE_DATA_CHANNELS 3094 3095 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 3096 if (!channel->waiting_for_can_send_now) return; 3097 if (channel->send_sdu_buffer) return; 3098 channel->waiting_for_can_send_now = 0; 3099 log_info("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 3100 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 3101 } 3102 3103 // 1BH2222 3104 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 3105 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", 3106 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 3107 uint8_t event[19]; 3108 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 3109 event[1] = sizeof(event) - 2; 3110 event[2] = channel->address_type; 3111 reverse_bd_addr(channel->address, &event[3]); 3112 little_endian_store_16(event, 9, channel->con_handle); 3113 little_endian_store_16(event, 11, channel->psm); 3114 little_endian_store_16(event, 13, channel->local_cid); 3115 little_endian_store_16(event, 15, channel->remote_cid); 3116 little_endian_store_16(event, 17, channel->remote_mtu); 3117 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 3118 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 3119 } 3120 // 11BH22222 3121 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 3122 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", 3123 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 3124 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 3125 uint8_t event[23]; 3126 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 3127 event[1] = sizeof(event) - 2; 3128 event[2] = status; 3129 event[3] = channel->address_type; 3130 reverse_bd_addr(channel->address, &event[4]); 3131 little_endian_store_16(event, 10, channel->con_handle); 3132 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 3133 little_endian_store_16(event, 13, channel->psm); 3134 little_endian_store_16(event, 15, channel->local_cid); 3135 little_endian_store_16(event, 17, channel->remote_cid); 3136 little_endian_store_16(event, 19, channel->local_mtu); 3137 little_endian_store_16(event, 21, channel->remote_mtu); 3138 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 3139 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 3140 } 3141 3142 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 3143 btstack_linked_list_iterator_t it; 3144 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 3145 while (btstack_linked_list_iterator_has_next(&it)){ 3146 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 3147 if ( channel->local_cid == local_cid) { 3148 return channel; 3149 } 3150 } 3151 return NULL; 3152 } 3153 3154 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 3155 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 3156 channel->state = L2CAP_STATE_CLOSED; 3157 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 3158 // discard channel 3159 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 3160 btstack_memory_l2cap_channel_free(channel); 3161 } 3162 3163 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 3164 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 3165 } 3166 3167 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 3168 3169 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 3170 3171 // check for alread registered psm 3172 l2cap_service_t *service = l2cap_le_get_service(psm); 3173 if (service) { 3174 return L2CAP_SERVICE_ALREADY_REGISTERED; 3175 } 3176 3177 // alloc structure 3178 service = btstack_memory_l2cap_service_get(); 3179 if (!service) { 3180 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 3181 return BTSTACK_MEMORY_ALLOC_FAILED; 3182 } 3183 3184 // fill in 3185 service->psm = psm; 3186 service->mtu = 0; 3187 service->packet_handler = packet_handler; 3188 service->required_security_level = security_level; 3189 3190 // add to services list 3191 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 3192 3193 // done 3194 return 0; 3195 } 3196 3197 uint8_t l2cap_le_unregister_service(uint16_t psm) { 3198 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 3199 l2cap_service_t *service = l2cap_le_get_service(psm); 3200 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 3201 3202 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 3203 btstack_memory_l2cap_service_free(service); 3204 return 0; 3205 } 3206 3207 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 3208 // get channel 3209 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3210 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3211 3212 // validate state 3213 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 3214 return ERROR_CODE_COMMAND_DISALLOWED; 3215 } 3216 3217 // set state accept connection 3218 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 3219 channel->receive_sdu_buffer = receive_sdu_buffer; 3220 channel->local_mtu = mtu; 3221 channel->new_credits_incoming = initial_credits; 3222 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 3223 3224 // test 3225 // channel->new_credits_incoming = 1; 3226 3227 // go 3228 l2cap_run(); 3229 return 0; 3230 } 3231 3232 /** 3233 * @brief Deny incoming LE Data Channel connection due to resource constraints 3234 * @param local_cid L2CAP LE Data Channel Identifier 3235 */ 3236 3237 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 3238 // get channel 3239 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3240 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3241 3242 // validate state 3243 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 3244 return ERROR_CODE_COMMAND_DISALLOWED; 3245 } 3246 3247 // set state decline connection 3248 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 3249 channel->reason = 0x04; // no resources available 3250 l2cap_run(); 3251 return 0; 3252 } 3253 3254 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 3255 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 3256 uint16_t * out_local_cid) { 3257 3258 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 3259 3260 3261 hci_connection_t * connection = hci_connection_for_handle(con_handle); 3262 if (!connection) { 3263 log_error("no hci_connection for handle 0x%04x", con_handle); 3264 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 3265 } 3266 3267 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 3268 if (!channel) { 3269 return BTSTACK_MEMORY_ALLOC_FAILED; 3270 } 3271 log_info("l2cap_le_create_channel %p", channel); 3272 3273 // store local_cid 3274 if (out_local_cid){ 3275 *out_local_cid = channel->local_cid; 3276 } 3277 3278 // provide buffer 3279 channel->con_handle = con_handle; 3280 channel->receive_sdu_buffer = receive_sdu_buffer; 3281 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 3282 channel->new_credits_incoming = initial_credits; 3283 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 3284 3285 // add to connections list 3286 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 3287 3288 // go 3289 l2cap_run(); 3290 return 0; 3291 } 3292 3293 /** 3294 * @brief Provide credtis for LE Data Channel 3295 * @param local_cid L2CAP LE Data Channel Identifier 3296 * @param credits Number additional credits for peer 3297 */ 3298 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 3299 3300 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3301 if (!channel) { 3302 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 3303 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3304 } 3305 3306 // check state 3307 if (channel->state != L2CAP_STATE_OPEN){ 3308 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 3309 } 3310 3311 // assert incoming credits + credits <= 0xffff 3312 uint32_t total_credits = channel->credits_incoming; 3313 total_credits += channel->new_credits_incoming; 3314 total_credits += credits; 3315 if (total_credits > 0xffff){ 3316 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 3317 channel->new_credits_incoming, credits); 3318 } 3319 3320 // set credits_granted 3321 channel->new_credits_incoming += credits; 3322 3323 // go 3324 l2cap_run(); 3325 return 0; 3326 } 3327 3328 /** 3329 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 3330 * @param local_cid L2CAP LE Data Channel Identifier 3331 */ 3332 int l2cap_le_can_send_now(uint16_t local_cid){ 3333 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3334 if (!channel) { 3335 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 3336 return 0; 3337 } 3338 3339 // check state 3340 if (channel->state != L2CAP_STATE_OPEN) return 0; 3341 3342 // check queue 3343 if (channel->send_sdu_buffer) return 0; 3344 3345 // fine, go ahead 3346 return 1; 3347 } 3348 3349 /** 3350 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 3351 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 3352 * so packet handler should be ready to handle it 3353 * @param local_cid L2CAP LE Data Channel Identifier 3354 */ 3355 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 3356 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3357 if (!channel) { 3358 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 3359 return 0; 3360 } 3361 channel->waiting_for_can_send_now = 1; 3362 l2cap_le_notify_channel_can_send(channel); 3363 return 0; 3364 } 3365 3366 /** 3367 * @brief Send data via LE Data Channel 3368 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 3369 * @param local_cid L2CAP LE Data Channel Identifier 3370 * @param data data to send 3371 * @param size data size 3372 */ 3373 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 3374 3375 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3376 if (!channel) { 3377 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 3378 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3379 } 3380 3381 if (len > channel->remote_mtu){ 3382 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 3383 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 3384 } 3385 3386 if (channel->send_sdu_buffer){ 3387 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 3388 return BTSTACK_ACL_BUFFERS_FULL; 3389 } 3390 3391 channel->send_sdu_buffer = data; 3392 channel->send_sdu_len = len; 3393 channel->send_sdu_pos = 0; 3394 3395 l2cap_run(); 3396 return 0; 3397 } 3398 3399 /** 3400 * @brief Disconnect from LE Data Channel 3401 * @param local_cid L2CAP LE Data Channel Identifier 3402 */ 3403 uint8_t l2cap_le_disconnect(uint16_t local_cid) 3404 { 3405 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3406 if (!channel) { 3407 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 3408 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3409 } 3410 3411 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3412 l2cap_run(); 3413 return 0; 3414 } 3415 3416 #endif 3417