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 uint8_t next_request; 131 } l2cap_fixed_channel_t; 132 133 #ifdef ENABLE_CLASSIC 134 static btstack_linked_list_t l2cap_channels; 135 static btstack_linked_list_t l2cap_services; 136 static uint8_t require_security_level2_for_outgoing_sdp; 137 #endif 138 139 #ifdef ENABLE_LE_DATA_CHANNELS 140 static btstack_linked_list_t l2cap_le_channels; 141 static btstack_linked_list_t l2cap_le_services; 142 #endif 143 144 // used to cache l2cap rejects, echo, and informational requests 145 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 146 static int signaling_responses_pending; 147 148 static btstack_packet_callback_registration_t hci_event_callback_registration; 149 #define FIXED_CHANNEL_FIFO_INVALID_INDEX 0xff 150 static l2cap_fixed_channel_t fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_SIZE]; 151 static uint8_t fixed_channel_head_index = FIXED_CHANNEL_FIFO_INVALID_INDEX; 152 static uint8_t fixed_channel_tail_index = FIXED_CHANNEL_FIFO_INVALID_INDEX; 153 154 #ifdef ENABLE_BLE 155 // only used for connection parameter update events 156 static btstack_packet_handler_t l2cap_event_packet_handler; 157 #endif 158 159 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 160 161 /* 162 * CRC lookup table for generator polynom D^16 + D^15 + D^2 + 1 163 */ 164 static const uint16_t crc16_table[256] = { 165 0x0000, 0xc0c1, 0xc181, 0x0140, 0xc301, 0x03c0, 0x0280, 0xc241, 0xc601, 0x06c0, 0x0780, 0xc741, 0x0500, 0xc5c1, 0xc481, 0x0440, 166 0xcc01, 0x0cc0, 0x0d80, 0xcd41, 0x0f00, 0xcfc1, 0xce81, 0x0e40, 0x0a00, 0xcac1, 0xcb81, 0x0b40, 0xc901, 0x09c0, 0x0880, 0xc841, 167 0xd801, 0x18c0, 0x1980, 0xd941, 0x1b00, 0xdbc1, 0xda81, 0x1a40, 0x1e00, 0xdec1, 0xdf81, 0x1f40, 0xdd01, 0x1dc0, 0x1c80, 0xdc41, 168 0x1400, 0xd4c1, 0xd581, 0x1540, 0xd701, 0x17c0, 0x1680, 0xd641, 0xd201, 0x12c0, 0x1380, 0xd341, 0x1100, 0xd1c1, 0xd081, 0x1040, 169 0xf001, 0x30c0, 0x3180, 0xf141, 0x3300, 0xf3c1, 0xf281, 0x3240, 0x3600, 0xf6c1, 0xf781, 0x3740, 0xf501, 0x35c0, 0x3480, 0xf441, 170 0x3c00, 0xfcc1, 0xfd81, 0x3d40, 0xff01, 0x3fc0, 0x3e80, 0xfe41, 0xfa01, 0x3ac0, 0x3b80, 0xfb41, 0x3900, 0xf9c1, 0xf881, 0x3840, 171 0x2800, 0xe8c1, 0xe981, 0x2940, 0xeb01, 0x2bc0, 0x2a80, 0xea41, 0xee01, 0x2ec0, 0x2f80, 0xef41, 0x2d00, 0xedc1, 0xec81, 0x2c40, 172 0xe401, 0x24c0, 0x2580, 0xe541, 0x2700, 0xe7c1, 0xe681, 0x2640, 0x2200, 0xe2c1, 0xe381, 0x2340, 0xe101, 0x21c0, 0x2080, 0xe041, 173 0xa001, 0x60c0, 0x6180, 0xa141, 0x6300, 0xa3c1, 0xa281, 0x6240, 0x6600, 0xa6c1, 0xa781, 0x6740, 0xa501, 0x65c0, 0x6480, 0xa441, 174 0x6c00, 0xacc1, 0xad81, 0x6d40, 0xaf01, 0x6fc0, 0x6e80, 0xae41, 0xaa01, 0x6ac0, 0x6b80, 0xab41, 0x6900, 0xa9c1, 0xa881, 0x6840, 175 0x7800, 0xb8c1, 0xb981, 0x7940, 0xbb01, 0x7bc0, 0x7a80, 0xba41, 0xbe01, 0x7ec0, 0x7f80, 0xbf41, 0x7d00, 0xbdc1, 0xbc81, 0x7c40, 176 0xb401, 0x74c0, 0x7580, 0xb541, 0x7700, 0xb7c1, 0xb681, 0x7640, 0x7200, 0xb2c1, 0xb381, 0x7340, 0xb101, 0x71c0, 0x7080, 0xb041, 177 0x5000, 0x90c1, 0x9181, 0x5140, 0x9301, 0x53c0, 0x5280, 0x9241, 0x9601, 0x56c0, 0x5780, 0x9741, 0x5500, 0x95c1, 0x9481, 0x5440, 178 0x9c01, 0x5cc0, 0x5d80, 0x9d41, 0x5f00, 0x9fc1, 0x9e81, 0x5e40, 0x5a00, 0x9ac1, 0x9b81, 0x5b40, 0x9901, 0x59c0, 0x5880, 0x9841, 179 0x8801, 0x48c0, 0x4980, 0x8941, 0x4b00, 0x8bc1, 0x8a81, 0x4a40, 0x4e00, 0x8ec1, 0x8f81, 0x4f40, 0x8d01, 0x4dc0, 0x4c80, 0x8c41, 180 0x4400, 0x84c1, 0x8581, 0x4540, 0x8701, 0x47c0, 0x4680, 0x8641, 0x8201, 0x42c0, 0x4380, 0x8341, 0x4100, 0x81c1, 0x8081, 0x4040, 181 }; 182 183 static uint16_t crc16_calc(uint8_t * data, uint16_t len){ 184 uint16_t crc = 0; // initial value = 0 185 while (len--){ 186 crc = (crc >> 8) ^ crc16_table[ (crc ^ ((uint16_t) *data++)) & 0x00FF ]; 187 } 188 return crc; 189 } 190 191 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){ 192 return (((uint16_t) sar) << 14) | (req_seq << 8) | (final << 7) | (tx_seq << 1) | 0; 193 } 194 195 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){ 196 return (req_seq << 8) | (final << 7) | (poll << 4) | (((int) supervisory_function) << 2) | 1; 197 } 198 199 static int l2cap_next_ertm_seq_nr(int seq_nr){ 200 return (seq_nr + 1) & 0x3f; 201 } 202 203 static int l2cap_ertm_can_store_packet_now(l2cap_channel_t * channel){ 204 // get num free tx buffers 205 int num_tx_buffers_used = channel->tx_write_index - channel->tx_read_index; 206 if (num_tx_buffers_used < 0){ 207 num_tx_buffers_used += channel->num_tx_buffers; 208 } 209 int num_free_tx_buffers = channel->num_tx_buffers - num_tx_buffers_used; 210 // calculate num tx buffers for remote MTU 211 int num_tx_buffers_for_max_remote_mtu; 212 if (channel->remote_mtu <= channel->remote_mps){ 213 // MTU fits into single packet 214 num_tx_buffers_for_max_remote_mtu = 1; 215 } else { 216 // include SDU Length 217 num_tx_buffers_for_max_remote_mtu = (channel->remote_mtu + 2 + (channel->remote_mps - 1)) / channel->remote_mps; 218 } 219 return num_tx_buffers_for_max_remote_mtu <= num_free_tx_buffers; 220 } 221 222 static void l2cap_ertm_next_tx_write_index(l2cap_channel_t * channel){ 223 channel->tx_write_index++; 224 if (channel->tx_write_index < channel->num_tx_buffers) return; 225 channel->tx_write_index = 0; 226 } 227 228 static void l2cap_ertm_start_monitor_timer(l2cap_channel_t * channel){ 229 log_info("Start Monitor timer"); 230 btstack_run_loop_remove_timer(&channel->monitor_timer); 231 btstack_run_loop_set_timer_handler(&channel->monitor_timer, &l2cap_ertm_monitor_timeout_callback); 232 btstack_run_loop_set_timer_context(&channel->monitor_timer, channel); 233 btstack_run_loop_set_timer(&channel->monitor_timer, channel->local_monitor_timeout_ms); 234 btstack_run_loop_add_timer(&channel->monitor_timer); 235 } 236 237 static void l2cap_ertm_stop_monitor_timer(l2cap_channel_t * channel){ 238 log_info("Stop Monitor timer"); 239 btstack_run_loop_remove_timer(&channel->monitor_timer); 240 } 241 242 static void l2cap_ertm_start_retransmission_timer(l2cap_channel_t * channel){ 243 log_info("Start Retransmission timer"); 244 btstack_run_loop_remove_timer(&channel->retransmission_timer); 245 btstack_run_loop_set_timer_handler(&channel->retransmission_timer, &l2cap_ertm_retransmission_timeout_callback); 246 btstack_run_loop_set_timer_context(&channel->retransmission_timer, channel); 247 btstack_run_loop_set_timer(&channel->retransmission_timer, channel->local_retransmission_timeout_ms); 248 btstack_run_loop_add_timer(&channel->retransmission_timer); 249 } 250 251 static void l2cap_ertm_stop_retransmission_timer(l2cap_channel_t * l2cap_channel){ 252 log_info("Stop Retransmission timer"); 253 btstack_run_loop_remove_timer(&l2cap_channel->retransmission_timer); 254 } 255 256 static void l2cap_ertm_monitor_timeout_callback(btstack_timer_source_t * ts){ 257 log_info("Monitor timeout"); 258 l2cap_channel_t * l2cap_channel = (l2cap_channel_t *) btstack_run_loop_get_timer_context(ts); 259 260 // TODO: we assume that it's the oldest packet 261 l2cap_ertm_tx_packet_state_t * tx_state; 262 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 263 264 // check retry count 265 if (tx_state->retry_count < l2cap_channel->remote_max_transmit){ 266 // increment retry count 267 tx_state->retry_count++; 268 269 l2cap_ertm_start_monitor_timer(l2cap_channel); 270 271 // send RR/P=1 272 l2cap_channel->send_supervisor_frame_receiver_ready_poll = 1; 273 } else { 274 log_info("Monitor timer expired & retry count >= max transmit -> disconnect"); 275 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 276 } 277 l2cap_run(); 278 } 279 280 static void l2cap_ertm_retransmission_timeout_callback(btstack_timer_source_t * ts){ 281 log_info("Retransmission timeout"); 282 l2cap_channel_t * l2cap_channel = (l2cap_channel_t *) btstack_run_loop_get_timer_context(ts); 283 284 // TODO: we assume that it's the oldest packet 285 l2cap_ertm_tx_packet_state_t * tx_state; 286 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 287 288 // set retry count = 1 289 tx_state->retry_count = 1; 290 291 // start monitor timer 292 l2cap_ertm_start_monitor_timer(l2cap_channel); 293 294 // send RR/P=1 295 l2cap_channel->send_supervisor_frame_receiver_ready_poll = 1; 296 l2cap_run(); 297 } 298 299 static int l2cap_ertm_send_information_frame(l2cap_channel_t * channel, int index, int final){ 300 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[index]; 301 hci_reserve_packet_buffer(); 302 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 303 uint16_t control = l2cap_encanced_control_field_for_information_frame(tx_state->tx_seq, final, channel->req_seq, tx_state->sar); 304 log_info("I-Frame: control 0x%04x", control); 305 little_endian_store_16(acl_buffer, 8, control); 306 memcpy(&acl_buffer[8+2], &channel->tx_packets_data[index * channel->local_mtu], tx_state->len); 307 // (re-)start retransmission timer on 308 l2cap_ertm_start_retransmission_timer(channel); 309 // send 310 return l2cap_send_prepared(channel->local_cid, 2 + tx_state->len); 311 } 312 313 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){ 314 // get next index for storing packets 315 int index = channel->tx_write_index; 316 317 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[index]; 318 tx_state->tx_seq = channel->next_tx_seq; 319 tx_state->len = len; 320 tx_state->sar = sar; 321 tx_state->retry_count = 0; 322 323 uint8_t * tx_packet = &channel->tx_packets_data[index * channel->local_mtu]; 324 int pos = 0; 325 if (sar == L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU){ 326 little_endian_store_16(tx_packet, 0, sdu_length); 327 pos += 2; 328 } 329 memcpy(&tx_packet[pos], data, len); 330 331 // update 332 channel->next_tx_seq = l2cap_next_ertm_seq_nr(channel->next_tx_seq); 333 l2cap_ertm_next_tx_write_index(channel); 334 335 log_info("l2cap_ertm_store_fragment: after store, tx_read_index %u, tx_write_index %u", channel->tx_read_index, channel->tx_write_index); 336 337 } 338 339 static int l2cap_ertm_send(l2cap_channel_t * channel, uint8_t * data, uint16_t len){ 340 if (len > channel->remote_mtu){ 341 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", channel->local_cid); 342 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 343 } 344 345 // check if it needs to get fragmented 346 if (len > channel->remote_mps){ 347 // fragmentation needed. 348 l2cap_segmentation_and_reassembly_t sar = L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU; 349 int chunk_len; 350 while (len){ 351 switch (sar){ 352 case L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU: 353 chunk_len = channel->remote_mps - 2; // sdu_length 354 l2cap_ertm_store_fragment(channel, sar, len, data, chunk_len); 355 len -= chunk_len; 356 sar = L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU; 357 break; 358 case L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU: 359 chunk_len = channel->remote_mps; 360 if (chunk_len >= len){ 361 sar = L2CAP_SEGMENTATION_AND_REASSEMBLY_END_OF_L2CAP_SDU; 362 chunk_len = len; 363 } 364 l2cap_ertm_store_fragment(channel, sar, len, data, chunk_len); 365 len -= chunk_len; 366 break; 367 default: 368 break; 369 } 370 } 371 372 } else { 373 l2cap_ertm_store_fragment(channel, L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU, 0, data, len); 374 } 375 376 // try to send 377 l2cap_run(); 378 return 0; 379 } 380 381 static uint16_t l2cap_setup_options_ertm_request(l2cap_channel_t * channel, uint8_t * config_options){ 382 config_options[0] = 0x04; // RETRANSMISSION AND FLOW CONTROL OPTION 383 config_options[1] = 9; // length 384 config_options[2] = (uint8_t) channel->mode; 385 config_options[3] = channel->num_rx_buffers; // == TxWindows size 386 config_options[4] = channel->local_max_transmit; 387 little_endian_store_16( config_options, 5, channel->local_retransmission_timeout_ms); 388 little_endian_store_16( config_options, 7, channel->local_monitor_timeout_ms); 389 little_endian_store_16( config_options, 9, channel->local_mps); 390 // 391 config_options[11] = 0x05; // FCS OPTION 392 config_options[12] = 1; // length 393 config_options[13] = channel->fcs_option; 394 return 14; 395 } 396 397 static uint16_t l2cap_setup_options_ertm_response(l2cap_channel_t * channel, uint8_t * config_options){ 398 config_options[0] = 0x04; // RETRANSMISSION AND FLOW CONTROL OPTION 399 config_options[1] = 9; // length 400 config_options[2] = (uint8_t) channel->mode; 401 // less or equal to remote tx window size 402 config_options[3] = btstack_min(channel->num_tx_buffers, channel->remote_tx_window_size); 403 // max transmit in response shall be ignored -> use sender values 404 config_options[4] = channel->remote_max_transmit; 405 // A value for the Retransmission time-out shall be sent in a positive Configuration Response 406 // and indicates the value that will be used by the sender of the Configuration Response -> use our value 407 little_endian_store_16( config_options, 5, channel->local_retransmission_timeout_ms); 408 // A value for the Monitor time-out shall be sent in a positive Configuration Response 409 // and indicates the value that will be used by the sender of the Configuration Response -> use our value 410 little_endian_store_16( config_options, 7, channel->local_monitor_timeout_ms); 411 // less or equal to remote mps 412 little_endian_store_16( config_options, 9, btstack_min(channel->local_mps, channel->remote_mps)); 413 // 414 config_options[11] = 0x05; // FCS OPTION 415 config_options[12] = 1; // length 416 config_options[13] = channel->fcs_option; 417 return 14; 418 } 419 420 static int l2cap_ertm_send_supervisor_frame(l2cap_channel_t * channel, uint16_t control){ 421 hci_reserve_packet_buffer(); 422 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 423 log_info("S-Frame: control 0x%04x", control); 424 little_endian_store_16(acl_buffer, 8, control); 425 return l2cap_send_prepared(channel->local_cid, 2); 426 } 427 428 static uint8_t l2cap_ertm_validate_local_config(l2cap_ertm_config_t * ertm_config){ 429 430 uint8_t result = ERROR_CODE_SUCCESS; 431 if (ertm_config->max_transmit < 1){ 432 log_error("max_transmit must be >= 1"); 433 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 434 } 435 if (ertm_config->retransmission_timeout_ms < 2000){ 436 log_error("retransmission_timeout_ms must be >= 2000 ms"); 437 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 438 } 439 if (ertm_config->monitor_timeout_ms < 12000){ 440 log_error("monitor_timeout_ms must be >= 12000 ms"); 441 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 442 } 443 if (ertm_config->local_mtu < 48){ 444 log_error("local_mtu must be >= 48"); 445 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 446 } 447 if (ertm_config->num_rx_buffers < 1){ 448 log_error("num_rx_buffers must be >= 1"); 449 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 450 } 451 if (ertm_config->num_tx_buffers < 1){ 452 log_error("num_rx_buffers must be >= 1"); 453 result = ERROR_CODE_INVALID_HCI_COMMAND_PARAMETERS; 454 } 455 return result; 456 } 457 458 static void l2cap_ertm_configure_channel(l2cap_channel_t * channel, l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size){ 459 460 channel->mode = L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION; 461 channel->ertm_mandatory = ertm_config->ertm_mandatory; 462 channel->local_max_transmit = ertm_config->max_transmit; 463 channel->local_retransmission_timeout_ms = ertm_config->retransmission_timeout_ms; 464 channel->local_monitor_timeout_ms = ertm_config->monitor_timeout_ms; 465 channel->local_mtu = ertm_config->local_mtu; 466 channel->num_rx_buffers = ertm_config->num_rx_buffers; 467 channel->num_tx_buffers = ertm_config->num_tx_buffers; 468 469 // align buffer to 16-byte boundary, just in case 470 int bytes_till_alignment = 16 - (((uintptr_t) buffer) & 0x0f); 471 buffer += bytes_till_alignment; 472 size -= bytes_till_alignment; 473 474 // setup state buffers 475 uint32_t pos = 0; 476 channel->rx_packets_state = (l2cap_ertm_rx_packet_state_t *) &buffer[pos]; 477 pos += ertm_config->num_rx_buffers * sizeof(l2cap_ertm_rx_packet_state_t); 478 channel->tx_packets_state = (l2cap_ertm_tx_packet_state_t *) &buffer[pos]; 479 pos += ertm_config->num_tx_buffers * sizeof(l2cap_ertm_tx_packet_state_t); 480 481 // setup reassembly buffer 482 channel->reassembly_buffer = &buffer[pos]; 483 pos += ertm_config->local_mtu; 484 485 // divide rest of data equally 486 channel->local_mps = (size - pos) / (ertm_config->num_rx_buffers + ertm_config->num_tx_buffers); 487 log_info("Local MPS: %u", channel->local_mps); 488 channel->rx_packets_data = &buffer[pos]; 489 pos += ertm_config->num_rx_buffers * channel->local_mps; 490 channel->tx_packets_data = &buffer[pos]; 491 492 // Issue: iOS (e.g. 10.2) uses "No FCS" as default while Core 5.0 specifies "FCS" as default 493 // Workaround: try to actively negotiate "No FCS" and fall back to "FCS" if "No FCS" is rejected 494 // This works as iOS accepts the "No FCS" request, hence the default value is only used on non-iOS devices 495 channel->fcs_option = 0; 496 } 497 498 uint8_t l2cap_create_ertm_channel(btstack_packet_handler_t packet_handler, bd_addr_t address, uint16_t psm, 499 l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size, uint16_t * out_local_cid){ 500 501 log_info("L2CAP_CREATE_ERTM_CHANNEL addr %s, psm 0x%x, local mtu %u", bd_addr_to_str(address), psm, ertm_config->local_mtu); 502 503 // validate local config 504 uint8_t result = l2cap_ertm_validate_local_config(ertm_config); 505 if (result) return result; 506 507 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, ertm_config->local_mtu, LEVEL_0); 508 if (!channel) { 509 return BTSTACK_MEMORY_ALLOC_FAILED; 510 } 511 512 // configure ERTM 513 l2cap_ertm_configure_channel(channel, ertm_config, buffer, size); 514 515 // add to connections list 516 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 517 518 // store local_cid 519 if (out_local_cid){ 520 *out_local_cid = channel->local_cid; 521 } 522 523 // check if hci connection is already usable 524 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 525 if (conn){ 526 log_info("l2cap_create_channel, hci connection already exists"); 527 l2cap_handle_connection_complete(conn->con_handle, channel); 528 // check if remote supported fearures are already received 529 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 530 l2cap_handle_remote_supported_features_received(channel); 531 } 532 } 533 534 l2cap_run(); 535 536 return 0; 537 } 538 539 static void l2cap_ertm_notify_channel_can_send(l2cap_channel_t * channel){ 540 if (l2cap_ertm_can_store_packet_now(channel)){ 541 channel->waiting_for_can_send_now = 0; 542 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 543 } 544 } 545 546 uint8_t l2cap_accept_ertm_connection(uint16_t local_cid, l2cap_ertm_config_t * ertm_config, uint8_t * buffer, uint32_t size){ 547 548 log_info("L2CAP_ACCEPT_ERTM_CONNECTION local_cid 0x%x", local_cid); 549 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 550 if (!channel) { 551 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 552 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 553 } 554 555 // validate local config 556 uint8_t result = l2cap_ertm_validate_local_config(ertm_config); 557 if (result) return result; 558 559 // configure L2CAP ERTM 560 l2cap_ertm_configure_channel(channel, ertm_config, buffer, size); 561 562 // continue 563 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 564 565 // process 566 l2cap_run(); 567 568 return ERROR_CODE_SUCCESS; 569 } 570 571 uint8_t l2cap_ertm_set_busy(uint16_t local_cid){ 572 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 573 if (!channel) { 574 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 575 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 576 } 577 if (!channel->local_busy){ 578 channel->local_busy = 1; 579 channel->send_supervisor_frame_receiver_not_ready = 1; 580 l2cap_run(); 581 } 582 return ERROR_CODE_SUCCESS; 583 } 584 585 uint8_t l2cap_ertm_set_ready(uint16_t local_cid){ 586 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 587 if (!channel) { 588 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 589 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 590 } 591 if (channel->local_busy){ 592 channel->local_busy = 0; 593 channel->send_supervisor_frame_receiver_ready_poll = 1; 594 l2cap_run(); 595 } 596 return ERROR_CODE_SUCCESS; 597 } 598 599 // Process-ReqSeq 600 static void l2cap_ertm_process_req_seq(l2cap_channel_t * l2cap_channel, uint8_t req_seq){ 601 int num_buffers_acked = 0; 602 l2cap_ertm_tx_packet_state_t * tx_state; 603 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); 604 while (1){ 605 606 // no unack packets left 607 if (l2cap_channel->unacked_frames == 0) { 608 // stop retransmission timer 609 l2cap_ertm_stop_retransmission_timer(l2cap_channel); 610 break; 611 } 612 613 tx_state = &l2cap_channel->tx_packets_state[l2cap_channel->tx_read_index]; 614 // calc delta 615 int delta = (req_seq - tx_state->tx_seq) & 0x03f; 616 if (delta == 0) break; // all packets acknowledged 617 if (delta > l2cap_channel->remote_tx_window_size) break; 618 619 num_buffers_acked++; 620 l2cap_channel->unacked_frames--; 621 log_info("RR seq %u => packet with tx_seq %u done", req_seq, tx_state->tx_seq); 622 623 l2cap_channel->tx_read_index++; 624 if (l2cap_channel->tx_read_index >= l2cap_channel->num_rx_buffers){ 625 l2cap_channel->tx_read_index = 0; 626 } 627 } 628 629 if (num_buffers_acked){ 630 l2cap_ertm_notify_channel_can_send(l2cap_channel); 631 } 632 } 633 634 static l2cap_ertm_tx_packet_state_t * l2cap_ertm_get_tx_state(l2cap_channel_t * l2cap_channel, uint8_t tx_seq){ 635 int i; 636 for (i=0;i<l2cap_channel->num_tx_buffers;i++){ 637 l2cap_ertm_tx_packet_state_t * tx_state = &l2cap_channel->tx_packets_state[i]; 638 if (tx_state->tx_seq == tx_seq) return tx_state; 639 } 640 return NULL; 641 } 642 643 // @param delta number of frames in the future, >= 1 644 // @assumption size <= l2cap_channel->local_mps (checked in l2cap_acl_classic_handler) 645 static void l2cap_ertm_handle_out_of_sequence_sdu(l2cap_channel_t * l2cap_channel, l2cap_segmentation_and_reassembly_t sar, int delta, const uint8_t * payload, uint16_t size){ 646 log_info("Store SDU with delta %u", delta); 647 // get rx state for packet to store 648 int index = l2cap_channel->rx_store_index + delta - 1; 649 if (index > l2cap_channel->num_rx_buffers){ 650 index -= l2cap_channel->num_rx_buffers; 651 } 652 log_info("Index of packet to store %u", index); 653 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 654 // check if buffer is free 655 if (rx_state->valid){ 656 log_error("Packet buffer already used"); 657 return; 658 } 659 rx_state->valid = 1; 660 rx_state->sar = sar; 661 rx_state->len = size; 662 uint8_t * rx_buffer = &l2cap_channel->rx_packets_data[index]; 663 memcpy(rx_buffer, payload, size); 664 } 665 666 // @assumption size <= l2cap_channel->local_mps (checked in l2cap_acl_classic_handler) 667 static void l2cap_ertm_handle_in_sequence_sdu(l2cap_channel_t * l2cap_channel, l2cap_segmentation_and_reassembly_t sar, const uint8_t * payload, uint16_t size){ 668 uint16_t reassembly_sdu_length; 669 switch (sar){ 670 case L2CAP_SEGMENTATION_AND_REASSEMBLY_UNSEGMENTED_L2CAP_SDU: 671 // assert total packet size <= our mtu 672 if (size > l2cap_channel->local_mtu) break; 673 // packet complete -> disapatch 674 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, (uint8_t*) payload, size); 675 break; 676 case L2CAP_SEGMENTATION_AND_REASSEMBLY_START_OF_L2CAP_SDU: 677 // read SDU len 678 reassembly_sdu_length = little_endian_read_16(payload, 0); 679 payload += 2; 680 size -= 2; 681 // assert reassembled size <= our mtu 682 if (reassembly_sdu_length > l2cap_channel->local_mtu) break; 683 // store start segment 684 l2cap_channel->reassembly_sdu_length = reassembly_sdu_length; 685 memcpy(&l2cap_channel->reassembly_buffer[0], payload, size); 686 l2cap_channel->reassembly_pos = size; 687 break; 688 case L2CAP_SEGMENTATION_AND_REASSEMBLY_CONTINUATION_OF_L2CAP_SDU: 689 // assert size of reassembled data <= our mtu 690 if (l2cap_channel->reassembly_pos + size > l2cap_channel->local_mtu) break; 691 // store continuation segment 692 memcpy(&l2cap_channel->reassembly_buffer[l2cap_channel->reassembly_pos], payload, size); 693 l2cap_channel->reassembly_pos += size; 694 break; 695 case L2CAP_SEGMENTATION_AND_REASSEMBLY_END_OF_L2CAP_SDU: 696 // assert size of reassembled data <= our mtu 697 if (l2cap_channel->reassembly_pos + size > l2cap_channel->local_mtu) break; 698 // store continuation segment 699 memcpy(&l2cap_channel->reassembly_buffer[l2cap_channel->reassembly_pos], payload, size); 700 l2cap_channel->reassembly_pos += size; 701 // assert size of reassembled data matches announced sdu length 702 if (l2cap_channel->reassembly_pos != l2cap_channel->reassembly_sdu_length) break; 703 // packet complete -> disapatch 704 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->reassembly_buffer, l2cap_channel->reassembly_pos); 705 l2cap_channel->reassembly_pos = 0; 706 break; 707 } 708 } 709 710 #endif 711 712 713 static uint16_t l2cap_fixed_channel_table_channel_id_for_index(int index){ 714 switch (index){ 715 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL: 716 return L2CAP_CID_ATTRIBUTE_PROTOCOL; 717 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL: 718 return L2CAP_CID_SECURITY_MANAGER_PROTOCOL; 719 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL: 720 return L2CAP_CID_CONNECTIONLESS_CHANNEL; 721 default: 722 return 0; 723 } 724 } 725 static int l2cap_fixed_channel_table_index_for_channel_id(uint16_t channel_id){ 726 switch (channel_id){ 727 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 728 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL; 729 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 730 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL; 731 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 732 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL; 733 default: 734 return -1; 735 } 736 } 737 738 static int l2cap_fixed_channel_table_index_is_le(int index){ 739 if (index == L2CAP_CID_CONNECTIONLESS_CHANNEL) return 0; 740 return 1; 741 } 742 743 void l2cap_init(void){ 744 signaling_responses_pending = 0; 745 746 #ifdef ENABLE_CLASSIC 747 l2cap_channels = NULL; 748 l2cap_services = NULL; 749 require_security_level2_for_outgoing_sdp = 0; 750 #endif 751 752 #ifdef ENABLE_LE_DATA_CHANNELS 753 l2cap_le_services = NULL; 754 l2cap_le_channels = NULL; 755 #endif 756 757 #ifdef ENABLE_BLE 758 l2cap_event_packet_handler = NULL; 759 #endif 760 memset(fixed_channels, 0, sizeof(fixed_channels)); 761 int i; 762 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 763 fixed_channels[i].next_request = FIXED_CHANNEL_FIFO_INVALID_INDEX; 764 } 765 766 // 767 // register callback with HCI 768 // 769 hci_event_callback_registration.callback = &l2cap_hci_event_handler; 770 hci_add_event_handler(&hci_event_callback_registration); 771 772 hci_register_acl_packet_handler(&l2cap_acl_handler); 773 774 #ifdef ENABLE_CLASSIC 775 gap_connectable_control(0); // no services yet 776 #endif 777 } 778 779 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 780 #ifdef ENABLE_BLE 781 l2cap_event_packet_handler = handler; 782 #else 783 UNUSED(handler); // ok: no code 784 #endif 785 } 786 787 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ 788 UNUSED(con_handle); // ok: there is no channel 789 790 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 791 if (index < 0) return; 792 793 // check if already registered 794 if (fixed_channels[index].waiting_for_can_send_now) return; 795 796 // insert into queue 797 if (fixed_channel_tail_index == FIXED_CHANNEL_FIFO_INVALID_INDEX){ 798 fixed_channel_head_index = index; 799 } else { 800 fixed_channels[fixed_channel_tail_index].next_request = index; 801 } 802 fixed_channel_tail_index = index; 803 fixed_channels[index].next_request = FIXED_CHANNEL_FIFO_INVALID_INDEX; 804 fixed_channels[index].waiting_for_can_send_now = 1; 805 l2cap_notify_channel_can_send(); 806 } 807 808 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ 809 UNUSED(channel_id); // ok: only depends on Controller LE buffers 810 811 return hci_can_send_acl_packet_now(con_handle); 812 } 813 814 uint8_t *l2cap_get_outgoing_buffer(void){ 815 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 816 } 817 818 int l2cap_reserve_packet_buffer(void){ 819 return hci_reserve_packet_buffer(); 820 } 821 822 void l2cap_release_packet_buffer(void){ 823 hci_release_packet_buffer(); 824 } 825 826 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){ 827 // 0 - Connection handle : PB=pb : BC=00 828 little_endian_store_16(acl_buffer, 0, con_handle | (packet_boundary << 12) | (0 << 14)); 829 // 2 - ACL length 830 little_endian_store_16(acl_buffer, 2, len + 4); 831 // 4 - L2CAP packet length 832 little_endian_store_16(acl_buffer, 4, len + 0); 833 // 6 - L2CAP channel DEST 834 little_endian_store_16(acl_buffer, 6, remote_cid); 835 } 836 837 // assumption - only on LE connections 838 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 839 840 if (!hci_is_packet_buffer_reserved()){ 841 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 842 return BTSTACK_ACL_BUFFERS_FULL; 843 } 844 845 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 846 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 847 return BTSTACK_ACL_BUFFERS_FULL; 848 } 849 850 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 851 852 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 853 l2cap_setup_header(acl_buffer, con_handle, 0, cid, len); 854 // send 855 return hci_send_acl_packet_buffer(len+8); 856 } 857 858 // assumption - only on LE connections 859 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 860 861 if (!hci_can_send_acl_packet_now(con_handle)){ 862 log_info("l2cap_send cid 0x%02x, cannot send", cid); 863 return BTSTACK_ACL_BUFFERS_FULL; 864 } 865 866 hci_reserve_packet_buffer(); 867 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 868 869 memcpy(&acl_buffer[8], data, len); 870 871 return l2cap_send_prepared_connectionless(con_handle, cid, len); 872 } 873 874 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { 875 log_debug("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); 876 uint8_t event[4]; 877 event[0] = L2CAP_EVENT_CAN_SEND_NOW; 878 event[1] = sizeof(event) - 2; 879 little_endian_store_16(event, 2, channel); 880 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 881 packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); 882 } 883 884 #ifdef L2CAP_USES_CHANNELS 885 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 886 (* (channel->packet_handler))(type, channel->local_cid, data, size); 887 } 888 889 static void l2cap_emit_simple_event_with_cid(l2cap_channel_t * channel, uint8_t event_code){ 890 uint8_t event[4]; 891 event[0] = event_code; 892 event[1] = sizeof(event) - 2; 893 little_endian_store_16(event, 2, channel->local_cid); 894 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 895 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 896 } 897 #endif 898 899 #ifdef ENABLE_CLASSIC 900 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 901 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", 902 status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 903 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 904 uint8_t event[24]; 905 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 906 event[1] = sizeof(event) - 2; 907 event[2] = status; 908 reverse_bd_addr(channel->address, &event[3]); 909 little_endian_store_16(event, 9, channel->con_handle); 910 little_endian_store_16(event, 11, channel->psm); 911 little_endian_store_16(event, 13, channel->local_cid); 912 little_endian_store_16(event, 15, channel->remote_cid); 913 little_endian_store_16(event, 17, channel->local_mtu); 914 little_endian_store_16(event, 19, channel->remote_mtu); 915 little_endian_store_16(event, 21, channel->flush_timeout); 916 event[23] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 917 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 918 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 919 } 920 921 static void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 922 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 923 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 924 } 925 926 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel) { 927 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 928 bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); 929 uint8_t event[16]; 930 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 931 event[1] = sizeof(event) - 2; 932 reverse_bd_addr(channel->address, &event[2]); 933 little_endian_store_16(event, 8, channel->con_handle); 934 little_endian_store_16(event, 10, channel->psm); 935 little_endian_store_16(event, 12, channel->local_cid); 936 little_endian_store_16(event, 14, channel->remote_cid); 937 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 938 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 939 } 940 941 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 942 btstack_linked_list_iterator_t it; 943 btstack_linked_list_iterator_init(&it, &l2cap_channels); 944 while (btstack_linked_list_iterator_has_next(&it)){ 945 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 946 if ( channel->local_cid == local_cid) { 947 return channel; 948 } 949 } 950 return NULL; 951 } 952 953 /// 954 955 void l2cap_request_can_send_now_event(uint16_t local_cid){ 956 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 957 if (!channel) return; 958 channel->waiting_for_can_send_now = 1; 959 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 960 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 961 l2cap_ertm_notify_channel_can_send(channel); 962 return; 963 } 964 #endif 965 l2cap_notify_channel_can_send(); 966 } 967 968 int l2cap_can_send_packet_now(uint16_t local_cid){ 969 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 970 if (!channel) return 0; 971 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 972 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 973 return l2cap_ertm_can_store_packet_now(channel); 974 } 975 #endif 976 return hci_can_send_acl_packet_now(channel->con_handle); 977 } 978 979 int l2cap_can_send_prepared_packet_now(uint16_t local_cid){ 980 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 981 if (!channel) return 0; 982 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 983 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 984 return 0; 985 } 986 #endif 987 return hci_can_send_prepared_acl_packet_now(channel->con_handle); 988 } 989 990 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 991 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 992 if (channel) { 993 return channel->remote_mtu; 994 } 995 return 0; 996 } 997 998 static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ 999 btstack_linked_list_iterator_t it; 1000 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1001 while (btstack_linked_list_iterator_has_next(&it)){ 1002 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1003 if ( &channel->rtx == ts) { 1004 return channel; 1005 } 1006 } 1007 return NULL; 1008 } 1009 1010 static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ 1011 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 1012 if (!channel) return; 1013 1014 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 1015 1016 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 1017 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 1018 // notify client 1019 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 1020 1021 // discard channel 1022 // no need to stop timer here, it is removed from list during timer callback 1023 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1024 btstack_memory_l2cap_channel_free(channel); 1025 } 1026 1027 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 1028 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 1029 btstack_run_loop_remove_timer(&channel->rtx); 1030 } 1031 1032 static void l2cap_start_rtx(l2cap_channel_t * channel){ 1033 l2cap_stop_rtx(channel); 1034 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 1035 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 1036 btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 1037 btstack_run_loop_add_timer(&channel->rtx); 1038 } 1039 1040 static void l2cap_start_ertx(l2cap_channel_t * channel){ 1041 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 1042 l2cap_stop_rtx(channel); 1043 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 1044 btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 1045 btstack_run_loop_add_timer(&channel->rtx); 1046 } 1047 1048 void l2cap_require_security_level_2_for_outgoing_sdp(void){ 1049 require_security_level2_for_outgoing_sdp = 1; 1050 } 1051 1052 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 1053 return (psm == BLUETOOTH_PROTOCOL_SDP) && (!require_security_level2_for_outgoing_sdp); 1054 } 1055 1056 static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, int identifier, ...){ 1057 if (!hci_can_send_acl_packet_now(handle)){ 1058 log_info("l2cap_send_signaling_packet, cannot send"); 1059 return BTSTACK_ACL_BUFFERS_FULL; 1060 } 1061 1062 // log_info("l2cap_send_signaling_packet type %u", cmd); 1063 hci_reserve_packet_buffer(); 1064 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1065 va_list argptr; 1066 va_start(argptr, identifier); 1067 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 1068 va_end(argptr); 1069 // log_info("l2cap_send_signaling_packet con %u!", handle); 1070 return hci_send_acl_packet_buffer(len); 1071 } 1072 1073 // assumption - only on Classic connections 1074 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 1075 1076 if (!hci_is_packet_buffer_reserved()){ 1077 log_error("l2cap_send_prepared called without reserving packet first"); 1078 return BTSTACK_ACL_BUFFERS_FULL; 1079 } 1080 1081 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1082 if (!channel) { 1083 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 1084 return -1; // TODO: define error 1085 } 1086 1087 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 1088 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 1089 return BTSTACK_ACL_BUFFERS_FULL; 1090 } 1091 1092 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 1093 1094 int fcs_size = 0; 1095 1096 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1097 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION && channel->fcs_option){ 1098 fcs_size = 2; 1099 } 1100 #endif 1101 1102 // set non-flushable packet boundary flag if supported on Controller 1103 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1104 uint8_t packet_boundary_flag = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 1105 l2cap_setup_header(acl_buffer, channel->con_handle, packet_boundary_flag, channel->remote_cid, len + fcs_size); 1106 1107 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1108 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1109 // calculate FCS over l2cap data 1110 uint16_t fcs = crc16_calc(acl_buffer + 4, 4 + len); 1111 log_info("I-Frame: fcs 0x%04x", fcs); 1112 little_endian_store_16(acl_buffer, 8 + len, fcs); 1113 } 1114 #endif 1115 1116 // send 1117 return hci_send_acl_packet_buffer(len+8+fcs_size); 1118 } 1119 1120 // assumption - only on Classic connections 1121 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 1122 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1123 if (!channel) { 1124 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 1125 return -1; // TODO: define error 1126 } 1127 1128 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1129 // send in ERTM 1130 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1131 return l2cap_ertm_send(channel, data, len); 1132 } 1133 #endif 1134 1135 if (len > channel->remote_mtu){ 1136 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 1137 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 1138 } 1139 1140 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 1141 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 1142 return BTSTACK_ACL_BUFFERS_FULL; 1143 } 1144 1145 hci_reserve_packet_buffer(); 1146 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1147 memcpy(&acl_buffer[8], data, len); 1148 return l2cap_send_prepared(local_cid, len); 1149 } 1150 1151 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ 1152 return l2cap_send_signaling_packet(con_handle, ECHO_REQUEST, 0x77, len, data); 1153 } 1154 1155 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 1156 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 1157 } 1158 1159 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 1160 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 1161 } 1162 #endif 1163 1164 1165 #ifdef ENABLE_BLE 1166 static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, int identifier, ...){ 1167 1168 if (!hci_can_send_acl_packet_now(handle)){ 1169 log_info("l2cap_send_le_signaling_packet, cannot send"); 1170 return BTSTACK_ACL_BUFFERS_FULL; 1171 } 1172 1173 // log_info("l2cap_send_le_signaling_packet type %u", cmd); 1174 hci_reserve_packet_buffer(); 1175 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1176 va_list argptr; 1177 va_start(argptr, identifier); 1178 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 1179 va_end(argptr); 1180 // log_info("l2cap_send_le_signaling_packet con %u!", handle); 1181 return hci_send_acl_packet_buffer(len); 1182 } 1183 #endif 1184 1185 uint16_t l2cap_max_mtu(void){ 1186 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 1187 } 1188 1189 uint16_t l2cap_max_le_mtu(void){ 1190 return l2cap_max_mtu(); 1191 } 1192 1193 #ifdef ENABLE_CLASSIC 1194 1195 static uint16_t l2cap_setup_options_mtu(uint8_t * config_options, uint16_t mtu){ 1196 config_options[0] = 1; // MTU 1197 config_options[1] = 2; // len param 1198 little_endian_store_16(config_options, 2, mtu); 1199 return 4; 1200 } 1201 1202 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1203 static int l2cap_ertm_mode(l2cap_channel_t * channel){ 1204 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1205 return ((connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_DONE) 1206 && (connection->l2cap_state.extended_feature_mask & 0x08)); 1207 } 1208 #endif 1209 1210 static uint16_t l2cap_setup_options_request(l2cap_channel_t * channel, uint8_t * config_options){ 1211 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1212 // use ERTM options if supported 1213 if (l2cap_ertm_mode(channel)){ 1214 return l2cap_setup_options_ertm_request(channel, config_options); 1215 } 1216 #endif 1217 uint16_t mtu = channel->local_mtu; 1218 return l2cap_setup_options_mtu(config_options, mtu); 1219 } 1220 1221 static uint16_t l2cap_setup_options_response(l2cap_channel_t * channel, uint8_t * config_options){ 1222 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1223 // use ERTM options if supported 1224 if (l2cap_ertm_mode(channel)){ 1225 return l2cap_setup_options_ertm_response(channel, config_options); 1226 } 1227 #endif 1228 uint16_t mtu = btstack_min(channel->local_mtu, channel->remote_mtu); 1229 return l2cap_setup_options_mtu(config_options, mtu); 1230 } 1231 1232 static uint32_t l2cap_extended_features_mask(void){ 1233 // extended features request supported, features: fixed channels, unicast connectionless data reception 1234 uint32_t features = 0x280; 1235 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1236 features |= 0x0008; 1237 #endif 1238 return features; 1239 } 1240 #endif 1241 1242 // MARK: L2CAP_RUN 1243 // process outstanding signaling tasks 1244 static void l2cap_run(void){ 1245 1246 // log_info("l2cap_run: entered"); 1247 1248 // check pending signaling responses 1249 while (signaling_responses_pending){ 1250 1251 hci_con_handle_t handle = signaling_responses[0].handle; 1252 1253 if (!hci_can_send_acl_packet_now(handle)) break; 1254 1255 uint8_t sig_id = signaling_responses[0].sig_id; 1256 uint8_t response_code = signaling_responses[0].code; 1257 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 1258 #ifdef ENABLE_CLASSIC 1259 uint16_t info_type = signaling_responses[0].data; // INFORMATION_REQUEST 1260 uint16_t source_cid = signaling_responses[0].cid; // CONNECTION_REQUEST 1261 #endif 1262 1263 // remove first item before sending (to avoid sending response mutliple times) 1264 signaling_responses_pending--; 1265 int i; 1266 for (i=0; i < signaling_responses_pending; i++){ 1267 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 1268 } 1269 1270 switch (response_code){ 1271 #ifdef ENABLE_CLASSIC 1272 case CONNECTION_REQUEST: 1273 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, source_cid, 0, result, 0); 1274 // also disconnect if result is 0x0003 - security blocked 1275 if (result == 0x0003){ 1276 hci_disconnect_security_block(handle); 1277 } 1278 break; 1279 case ECHO_REQUEST: 1280 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 1281 break; 1282 case INFORMATION_REQUEST: 1283 switch (info_type){ 1284 case L2CAP_INFO_TYPE_CONNECTIONLESS_MTU: { 1285 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 1286 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 0, sizeof(connectionless_mtu), &connectionless_mtu); 1287 } 1288 break; 1289 case L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED: { 1290 uint32_t features = l2cap_extended_features_mask(); 1291 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 0, sizeof(features), &features); 1292 } 1293 break; 1294 case L2CAP_INFO_TYPE_FIXED_CHANNELS_SUPPORTED: { 1295 uint8_t map[8]; 1296 memset(map, 0, 8); 1297 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 1298 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 0, sizeof(map), &map); 1299 } 1300 break; 1301 default: 1302 // all other types are not supported 1303 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, info_type, 1, 0, NULL); 1304 break; 1305 } 1306 break; 1307 case COMMAND_REJECT: 1308 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 1309 break; 1310 #endif 1311 #ifdef ENABLE_BLE 1312 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1313 l2cap_send_le_signaling_packet(handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, sig_id, 0, 0, 0, 0, result); 1314 break; 1315 case COMMAND_REJECT_LE: 1316 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 1317 break; 1318 #endif 1319 default: 1320 // should not happen 1321 break; 1322 } 1323 } 1324 1325 #if defined(ENABLE_CLASSIC) || defined(ENABLE_BLE) 1326 btstack_linked_list_iterator_t it; 1327 #endif 1328 1329 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1330 // send l2cap information request if neccessary 1331 hci_connections_get_iterator(&it); 1332 while(btstack_linked_list_iterator_has_next(&it)){ 1333 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1334 if (connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST){ 1335 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W4_EXTENDED_FEATURE_RESPONSE; 1336 // send information request for extended features 1337 uint8_t sig_id = l2cap_next_sig_id(); 1338 uint8_t info_type = L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED; 1339 l2cap_send_signaling_packet(connection->con_handle, INFORMATION_REQUEST, sig_id, info_type); 1340 return; 1341 } 1342 } 1343 #endif 1344 1345 #ifdef ENABLE_CLASSIC 1346 uint8_t config_options[10]; 1347 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1348 while (btstack_linked_list_iterator_has_next(&it)){ 1349 1350 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1351 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 1352 switch (channel->state){ 1353 1354 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1355 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 1356 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1357 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 1358 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 1359 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 1360 } 1361 break; 1362 1363 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1364 if (!hci_can_send_command_packet_now()) break; 1365 // send connection request - set state first 1366 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 1367 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 1368 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 1369 break; 1370 1371 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 1372 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1373 channel->state = L2CAP_STATE_INVALID; 1374 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 1375 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 1376 l2cap_stop_rtx(channel); 1377 btstack_linked_list_iterator_remove(&it); 1378 btstack_memory_l2cap_channel_free(channel); 1379 break; 1380 1381 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 1382 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1383 channel->state = L2CAP_STATE_CONFIG; 1384 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1385 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 1386 break; 1387 1388 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 1389 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1390 // success, start l2cap handshake 1391 channel->local_sig_id = l2cap_next_sig_id(); 1392 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 1393 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 1394 l2cap_start_rtx(channel); 1395 break; 1396 1397 case L2CAP_STATE_CONFIG: 1398 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1399 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 1400 uint16_t flags = 0; 1401 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1402 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 1403 flags = 1; 1404 } else { 1405 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 1406 } 1407 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 1408 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 1409 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 1410 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1411 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED){ 1412 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 1413 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 1414 uint16_t options_size = l2cap_setup_options_response(channel, config_options); 1415 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); 1416 #endif 1417 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 1418 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1419 uint16_t options_size = l2cap_setup_options_response(channel, config_options); 1420 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); 1421 } else { 1422 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_SUCCESS, 0, NULL); 1423 } 1424 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1425 } 1426 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 1427 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1428 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 1429 channel->local_sig_id = l2cap_next_sig_id(); 1430 uint16_t options_size = l2cap_setup_options_request(channel, config_options); 1431 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, options_size, &config_options); 1432 l2cap_start_rtx(channel); 1433 } 1434 if (l2cap_channel_ready_for_open(channel)){ 1435 channel->state = L2CAP_STATE_OPEN; 1436 l2cap_emit_channel_opened(channel, 0); // success 1437 } 1438 break; 1439 1440 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 1441 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1442 channel->state = L2CAP_STATE_INVALID; 1443 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 1444 // 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 :) 1445 l2cap_finialize_channel_close(channel); // -- remove from list 1446 break; 1447 1448 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1449 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1450 channel->local_sig_id = l2cap_next_sig_id(); 1451 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 1452 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 1453 break; 1454 default: 1455 break; 1456 } 1457 1458 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1459 // send s-frame to acknowledge received packets 1460 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1461 1462 if (channel->tx_send_index != channel->tx_write_index){ 1463 // check remote tx window 1464 log_info("unacknowledged_packets %u, remote tx window size %u", channel->unacked_frames, channel->remote_tx_window_size); 1465 if (channel->unacked_frames < channel->remote_tx_window_size){ 1466 channel->unacked_frames++; 1467 int index = channel->tx_send_index; 1468 channel->tx_send_index++; 1469 if (channel->tx_send_index >= channel->num_tx_buffers){ 1470 channel->tx_send_index = 0; 1471 } 1472 l2cap_ertm_send_information_frame(channel, index, 0); // final = 0 1473 continue; 1474 } 1475 } 1476 1477 if (channel->send_supervisor_frame_receiver_ready){ 1478 channel->send_supervisor_frame_receiver_ready = 0; 1479 log_info("Send S-Frame: RR %u, final %u", channel->req_seq, channel->set_final_bit_after_packet_with_poll_bit_set); 1480 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); 1481 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1482 l2cap_ertm_send_supervisor_frame(channel, control); 1483 continue; 1484 } 1485 if (channel->send_supervisor_frame_receiver_ready_poll){ 1486 channel->send_supervisor_frame_receiver_ready_poll = 0; 1487 log_info("Send S-Frame: RR %u with poll=1 ", channel->req_seq); 1488 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY, 1, 0, channel->req_seq); 1489 l2cap_ertm_send_supervisor_frame(channel, control); 1490 continue; 1491 } 1492 if (channel->send_supervisor_frame_receiver_not_ready){ 1493 channel->send_supervisor_frame_receiver_not_ready = 0; 1494 log_info("Send S-Frame: RNR %u", channel->req_seq); 1495 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY, 0, 0, channel->req_seq); 1496 l2cap_ertm_send_supervisor_frame(channel, control); 1497 continue; 1498 } 1499 if (channel->send_supervisor_frame_reject){ 1500 channel->send_supervisor_frame_reject = 0; 1501 log_info("Send S-Frame: REJ %u", channel->req_seq); 1502 uint16_t control = l2cap_encanced_control_field_for_supevisor_frame( L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT, 0, 0, channel->req_seq); 1503 l2cap_ertm_send_supervisor_frame(channel, control); 1504 continue; 1505 } 1506 if (channel->send_supervisor_frame_selective_reject){ 1507 channel->send_supervisor_frame_selective_reject = 0; 1508 log_info("Send S-Frame: SREJ %u", channel->expected_tx_seq); 1509 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); 1510 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1511 l2cap_ertm_send_supervisor_frame(channel, control); 1512 continue; 1513 } 1514 1515 if (channel->srej_active){ 1516 int i; 1517 for (i=0;i<channel->num_tx_buffers;i++){ 1518 l2cap_ertm_tx_packet_state_t * tx_state = &channel->tx_packets_state[i]; 1519 if (tx_state->retransmission_requested) { 1520 tx_state->retransmission_requested = 0; 1521 uint8_t final = channel->set_final_bit_after_packet_with_poll_bit_set; 1522 channel->set_final_bit_after_packet_with_poll_bit_set = 0; 1523 l2cap_ertm_send_information_frame(channel, i, final); 1524 break; 1525 } 1526 } 1527 if (i == channel->num_tx_buffers){ 1528 // no retransmission request found 1529 channel->srej_active = 0; 1530 } else { 1531 // packet was sent 1532 continue; 1533 } 1534 } 1535 #endif 1536 1537 } 1538 #endif 1539 1540 #ifdef ENABLE_LE_DATA_CHANNELS 1541 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1542 while (btstack_linked_list_iterator_has_next(&it)){ 1543 uint8_t * acl_buffer; 1544 uint8_t * l2cap_payload; 1545 uint16_t pos; 1546 uint16_t payload_size; 1547 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1548 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 1549 switch (channel->state){ 1550 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 1551 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1552 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 1553 // le psm, source cid, mtu, mps, initial credits 1554 channel->local_sig_id = l2cap_next_sig_id(); 1555 channel->credits_incoming = channel->new_credits_incoming; 1556 channel->new_credits_incoming = 0; 1557 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); 1558 break; 1559 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 1560 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1561 // TODO: support larger MPS 1562 channel->state = L2CAP_STATE_OPEN; 1563 channel->credits_incoming = channel->new_credits_incoming; 1564 channel->new_credits_incoming = 0; 1565 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); 1566 // notify client 1567 l2cap_emit_le_channel_opened(channel, 0); 1568 break; 1569 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 1570 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1571 channel->state = L2CAP_STATE_INVALID; 1572 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); 1573 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 1574 l2cap_stop_rtx(channel); 1575 btstack_linked_list_iterator_remove(&it); 1576 btstack_memory_l2cap_channel_free(channel); 1577 break; 1578 case L2CAP_STATE_OPEN: 1579 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1580 1581 // send credits 1582 if (channel->new_credits_incoming){ 1583 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 1584 channel->local_sig_id = l2cap_next_sig_id(); 1585 uint16_t new_credits = channel->new_credits_incoming; 1586 channel->new_credits_incoming = 0; 1587 channel->credits_incoming += new_credits; 1588 l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); 1589 break; 1590 } 1591 1592 // send data 1593 if (!channel->send_sdu_buffer) break; 1594 if (!channel->credits_outgoing) break; 1595 1596 // send part of SDU 1597 hci_reserve_packet_buffer(); 1598 acl_buffer = hci_get_outgoing_packet_buffer(); 1599 l2cap_payload = acl_buffer + 8; 1600 pos = 0; 1601 if (!channel->send_sdu_pos){ 1602 // store SDU len 1603 channel->send_sdu_pos += 2; 1604 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 1605 pos += 2; 1606 } 1607 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 1608 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); 1609 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 1610 pos += payload_size; 1611 channel->send_sdu_pos += payload_size; 1612 l2cap_setup_header(acl_buffer, channel->con_handle, 0, channel->remote_cid, pos); 1613 // done 1614 1615 channel->credits_outgoing--; 1616 1617 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 1618 channel->send_sdu_buffer = NULL; 1619 // send done event 1620 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_PACKET_SENT); 1621 // inform about can send now 1622 l2cap_le_notify_channel_can_send(channel); 1623 } 1624 hci_send_acl_packet_buffer(8 + pos); 1625 break; 1626 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1627 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1628 channel->local_sig_id = l2cap_next_sig_id(); 1629 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 1630 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 1631 break; 1632 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 1633 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 1634 channel->state = L2CAP_STATE_INVALID; 1635 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 1636 l2cap_le_finialize_channel_close(channel); // -- remove from list 1637 break; 1638 default: 1639 break; 1640 } 1641 } 1642 #endif 1643 1644 #ifdef ENABLE_BLE 1645 // send l2cap con paramter update if necessary 1646 hci_connections_get_iterator(&it); 1647 while(btstack_linked_list_iterator_has_next(&it)){ 1648 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 1649 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 1650 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 1651 switch (connection->le_con_parameter_update_state){ 1652 case CON_PARAMETER_UPDATE_SEND_REQUEST: 1653 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 1654 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 1655 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 1656 break; 1657 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 1658 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 1659 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 1660 break; 1661 case CON_PARAMETER_UPDATE_DENY: 1662 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 1663 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 1664 break; 1665 default: 1666 break; 1667 } 1668 } 1669 #endif 1670 1671 // log_info("l2cap_run: exit"); 1672 } 1673 1674 #ifdef ENABLE_CLASSIC 1675 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 1676 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 1677 log_info("l2cap_handle_connection_complete expected state"); 1678 // success, start l2cap handshake 1679 channel->con_handle = con_handle; 1680 // check remote SSP feature first 1681 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 1682 } 1683 } 1684 1685 static void l2cap_ready_to_connect(l2cap_channel_t * channel){ 1686 1687 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1688 // assumption: outgoing connection 1689 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 1690 if (connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_IDLE){ 1691 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 1692 channel->state = L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES; 1693 return; 1694 } 1695 #endif 1696 1697 // fine, go ahead 1698 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1699 } 1700 1701 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 1702 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 1703 1704 // we have been waiting for remote supported features, if both support SSP, 1705 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)); 1706 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 1707 // request security level 2 1708 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 1709 channel->required_security_level = LEVEL_2; 1710 gap_request_security_level(channel->con_handle, LEVEL_2); 1711 return; 1712 } 1713 1714 l2cap_ready_to_connect(channel); 1715 } 1716 #endif 1717 1718 #ifdef L2CAP_USES_CHANNELS 1719 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 1720 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 1721 1722 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 1723 if (!channel) { 1724 return NULL; 1725 } 1726 1727 // Init memory (make valgrind happy) 1728 memset(channel, 0, sizeof(l2cap_channel_t)); 1729 1730 // fill in 1731 channel->packet_handler = packet_handler; 1732 bd_addr_copy(channel->address, address); 1733 channel->address_type = address_type; 1734 channel->psm = psm; 1735 channel->local_mtu = local_mtu; 1736 channel->remote_mtu = L2CAP_MINIMAL_MTU; 1737 channel->required_security_level = security_level; 1738 1739 // 1740 channel->local_cid = l2cap_next_local_cid(); 1741 channel->con_handle = 0; 1742 1743 // set initial state 1744 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 1745 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 1746 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 1747 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 1748 1749 return channel; 1750 } 1751 #endif 1752 1753 #ifdef ENABLE_CLASSIC 1754 1755 /** 1756 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 1757 * @param packet_handler 1758 * @param address 1759 * @param psm 1760 * @param mtu 1761 * @param local_cid 1762 */ 1763 1764 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){ 1765 // limit MTU to the size of our outtgoing HCI buffer 1766 uint16_t local_mtu = btstack_min(mtu, l2cap_max_mtu()); 1767 1768 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u -> local mtu %u", bd_addr_to_str(address), psm, mtu, local_mtu); 1769 1770 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 1771 if (!channel) { 1772 return BTSTACK_MEMORY_ALLOC_FAILED; 1773 } 1774 1775 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1776 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1777 #endif 1778 1779 // add to connections list 1780 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1781 1782 // store local_cid 1783 if (out_local_cid){ 1784 *out_local_cid = channel->local_cid; 1785 } 1786 1787 // check if hci connection is already usable 1788 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 1789 if (conn){ 1790 log_info("l2cap_create_channel, hci connection already exists"); 1791 l2cap_handle_connection_complete(conn->con_handle, channel); 1792 // check if remote supported fearures are already received 1793 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 1794 l2cap_handle_remote_supported_features_received(channel); 1795 } 1796 } 1797 1798 l2cap_run(); 1799 1800 return 0; 1801 } 1802 1803 void 1804 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 1805 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 1806 // find channel for local_cid 1807 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1808 if (channel) { 1809 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1810 } 1811 // process 1812 l2cap_run(); 1813 } 1814 1815 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 1816 btstack_linked_list_iterator_t it; 1817 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1818 while (btstack_linked_list_iterator_has_next(&it)){ 1819 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1820 if ( bd_addr_cmp( channel->address, address) != 0) continue; 1821 // channel for this address found 1822 switch (channel->state){ 1823 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1824 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1825 // failure, forward error code 1826 l2cap_emit_channel_opened(channel, status); 1827 // discard channel 1828 l2cap_stop_rtx(channel); 1829 btstack_linked_list_iterator_remove(&it); 1830 btstack_memory_l2cap_channel_free(channel); 1831 break; 1832 default: 1833 break; 1834 } 1835 } 1836 } 1837 1838 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1839 btstack_linked_list_iterator_t it; 1840 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1841 while (btstack_linked_list_iterator_has_next(&it)){ 1842 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1843 if ( ! bd_addr_cmp( channel->address, address) ){ 1844 l2cap_handle_connection_complete(handle, channel); 1845 } 1846 } 1847 // process 1848 l2cap_run(); 1849 } 1850 #endif 1851 1852 static void l2cap_notify_channel_can_send(void){ 1853 1854 #ifdef ENABLE_CLASSIC 1855 btstack_linked_list_iterator_t it; 1856 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1857 while (btstack_linked_list_iterator_has_next(&it)){ 1858 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1859 if (!channel->waiting_for_can_send_now) continue; 1860 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1861 channel->waiting_for_can_send_now = 0; 1862 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1863 } 1864 #endif 1865 1866 #if 1 1867 if (fixed_channel_head_index != FIXED_CHANNEL_FIFO_INVALID_INDEX){ 1868 int can_send = 0; 1869 int remove_entry = 1; 1870 uint8_t i = fixed_channel_head_index; 1871 if (fixed_channels[i].callback && fixed_channels[i].waiting_for_can_send_now){ 1872 if (l2cap_fixed_channel_table_index_is_le(i)){ 1873 #ifdef ENABLE_BLE 1874 can_send = hci_can_send_acl_le_packet_now(); 1875 remove_entry = can_send; 1876 #endif 1877 } else { 1878 #ifdef ENABLE_CLASSIC 1879 can_send = hci_can_send_acl_classic_packet_now(); 1880 remove_entry = can_send; 1881 #endif 1882 } 1883 } 1884 // remove entry 1885 if (remove_entry){ 1886 fixed_channels[i].waiting_for_can_send_now = 0; 1887 fixed_channel_head_index = fixed_channels[i].next_request; 1888 fixed_channels[i].next_request = FIXED_CHANNEL_FIFO_INVALID_INDEX; 1889 if (fixed_channel_head_index == FIXED_CHANNEL_FIFO_INVALID_INDEX){ 1890 fixed_channel_tail_index = FIXED_CHANNEL_FIFO_INVALID_INDEX; 1891 } 1892 } 1893 // notify 1894 if (can_send) { 1895 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1896 } 1897 } 1898 #else 1899 int i; 1900 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1901 if (!fixed_channels[i].callback) continue; 1902 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1903 int can_send = 0; 1904 if (l2cap_fixed_channel_table_index_is_le(i)){ 1905 #ifdef ENABLE_BLE 1906 can_send = hci_can_send_acl_le_packet_now(); 1907 #endif 1908 } else { 1909 #ifdef ENABLE_CLASSIC 1910 can_send = hci_can_send_acl_classic_packet_now(); 1911 #endif 1912 } 1913 if (!can_send) continue; 1914 fixed_channels[i].waiting_for_can_send_now = 0; 1915 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1916 } 1917 1918 #endif 1919 1920 } 1921 1922 #ifdef L2CAP_USES_CHANNELS 1923 1924 static int l2cap_send_open_failed_on_hci_disconnect(l2cap_channel_t * channel){ 1925 // open cannot fail for for incoming connections 1926 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING) return 0; 1927 1928 // check state 1929 switch (channel->state){ 1930 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1931 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1932 case L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES: 1933 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1934 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 1935 case L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES: 1936 case L2CAP_STATE_WAIT_CONNECT_RSP: 1937 case L2CAP_STATE_CONFIG: 1938 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 1939 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 1940 case L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE: 1941 return 1; 1942 1943 case L2CAP_STATE_OPEN: 1944 case L2CAP_STATE_CLOSED: 1945 case L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES: 1946 case L2CAP_STATE_WAIT_DISCONNECT: 1947 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_INSUFFICIENT_SECURITY: 1948 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 1949 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 1950 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1951 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 1952 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 1953 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 1954 case L2CAP_STATE_INVALID: 1955 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1956 return 0; 1957 // no default here, to get a warning about new states 1958 } 1959 // still, the compiler insists on a return value 1960 return 0; 1961 } 1962 1963 static void l2cap_handle_hci_disconnect_event(l2cap_channel_t * channel){ 1964 if (l2cap_send_open_failed_on_hci_disconnect(channel)){ 1965 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_BASEBAND_DISCONNECT); 1966 } else { 1967 l2cap_emit_channel_closed(channel); 1968 } 1969 btstack_memory_l2cap_channel_free(channel); 1970 } 1971 1972 #endif 1973 1974 1975 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1976 1977 UNUSED(packet_type); // ok: registered with hci_event_callback_registration 1978 UNUSED(cid); // ok: there is no channel 1979 UNUSED(size); // ok: fixed format events read from HCI buffer 1980 1981 #ifdef ENABLE_CLASSIC 1982 bd_addr_t address; 1983 int hci_con_used; 1984 #endif 1985 #ifdef L2CAP_USES_CHANNELS 1986 hci_con_handle_t handle; 1987 btstack_linked_list_iterator_t it; 1988 #endif 1989 1990 switch(hci_event_packet_get_type(packet)){ 1991 1992 // Notify channel packet handler if they can send now 1993 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1994 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1995 l2cap_run(); // try sending signaling packets first 1996 l2cap_notify_channel_can_send(); 1997 break; 1998 1999 case HCI_EVENT_COMMAND_STATUS: 2000 l2cap_run(); // try sending signaling packets first 2001 break; 2002 2003 #ifdef ENABLE_CLASSIC 2004 // handle connection complete events 2005 case HCI_EVENT_CONNECTION_COMPLETE: 2006 reverse_bd_addr(&packet[5], address); 2007 if (packet[2] == 0){ 2008 handle = little_endian_read_16(packet, 3); 2009 l2cap_handle_connection_success_for_addr(address, handle); 2010 } else { 2011 l2cap_handle_connection_failed_for_addr(address, packet[2]); 2012 } 2013 break; 2014 2015 // handle successful create connection cancel command 2016 case HCI_EVENT_COMMAND_COMPLETE: 2017 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 2018 if (packet[5] == 0){ 2019 reverse_bd_addr(&packet[6], address); 2020 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 2021 l2cap_handle_connection_failed_for_addr(address, 0x16); 2022 } 2023 } 2024 l2cap_run(); // try sending signaling packets first 2025 break; 2026 #endif 2027 2028 #ifdef L2CAP_USES_CHANNELS 2029 // handle disconnection complete events 2030 case HCI_EVENT_DISCONNECTION_COMPLETE: 2031 handle = little_endian_read_16(packet, 3); 2032 // send l2cap open failed or closed events for all channels on this handle and free them 2033 #ifdef ENABLE_CLASSIC 2034 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2035 while (btstack_linked_list_iterator_has_next(&it)){ 2036 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2037 if (channel->con_handle != handle) continue; 2038 btstack_linked_list_iterator_remove(&it); 2039 l2cap_stop_rtx(channel); 2040 l2cap_handle_hci_disconnect_event(channel); 2041 } 2042 #endif 2043 #ifdef ENABLE_LE_DATA_CHANNELS 2044 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2045 while (btstack_linked_list_iterator_has_next(&it)){ 2046 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2047 if (channel->con_handle != handle) continue; 2048 btstack_linked_list_iterator_remove(&it); 2049 l2cap_handle_hci_disconnect_event(channel); 2050 } 2051 #endif 2052 break; 2053 #endif 2054 2055 // HCI Connection Timeouts 2056 #ifdef ENABLE_CLASSIC 2057 case L2CAP_EVENT_TIMEOUT_CHECK: 2058 handle = little_endian_read_16(packet, 2); 2059 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 2060 if (hci_authentication_active_for_handle(handle)) break; 2061 hci_con_used = 0; 2062 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2063 while (btstack_linked_list_iterator_has_next(&it)){ 2064 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2065 if (channel->con_handle != handle) continue; 2066 hci_con_used = 1; 2067 break; 2068 } 2069 if (hci_con_used) break; 2070 if (!hci_can_send_command_packet_now()) break; 2071 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 2072 break; 2073 2074 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 2075 handle = little_endian_read_16(packet, 3); 2076 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2077 while (btstack_linked_list_iterator_has_next(&it)){ 2078 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2079 if (channel->con_handle != handle) continue; 2080 l2cap_handle_remote_supported_features_received(channel); 2081 break; 2082 } 2083 break; 2084 2085 case GAP_EVENT_SECURITY_LEVEL: 2086 handle = little_endian_read_16(packet, 2); 2087 log_info("l2cap - security level update"); 2088 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2089 while (btstack_linked_list_iterator_has_next(&it)){ 2090 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2091 if (channel->con_handle != handle) continue; 2092 2093 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 2094 gap_security_level_t required_level = channel->required_security_level; 2095 2096 log_info("channel state %u: actual %u >= required %u?", channel->state, actual_level, required_level); 2097 2098 switch (channel->state){ 2099 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 2100 if (actual_level >= required_level){ 2101 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2102 // we need to know if ERTM is supported before sending a config response 2103 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 2104 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 2105 channel->state = L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES; 2106 #else 2107 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2108 l2cap_emit_incoming_connection(channel); 2109 #endif 2110 } else { 2111 channel->reason = 0x0003; // security block 2112 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 2113 } 2114 break; 2115 2116 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 2117 if (actual_level >= required_level){ 2118 l2cap_ready_to_connect(channel); 2119 } else { 2120 // disconnnect, authentication not good enough 2121 hci_disconnect_security_block(handle); 2122 } 2123 break; 2124 2125 default: 2126 break; 2127 } 2128 } 2129 break; 2130 #endif 2131 2132 default: 2133 break; 2134 } 2135 2136 l2cap_run(); 2137 } 2138 2139 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t cid, uint16_t data){ 2140 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 2141 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 2142 signaling_responses[signaling_responses_pending].handle = handle; 2143 signaling_responses[signaling_responses_pending].code = code; 2144 signaling_responses[signaling_responses_pending].sig_id = sig_id; 2145 signaling_responses[signaling_responses_pending].cid = cid; 2146 signaling_responses[signaling_responses_pending].data = data; 2147 signaling_responses_pending++; 2148 l2cap_run(); 2149 } 2150 } 2151 2152 #ifdef ENABLE_CLASSIC 2153 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 2154 channel->remote_sig_id = identifier; 2155 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 2156 l2cap_run(); 2157 } 2158 2159 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 2160 2161 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 2162 l2cap_service_t *service = l2cap_get_service(psm); 2163 if (!service) { 2164 // 0x0002 PSM not supported 2165 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 2166 return; 2167 } 2168 2169 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 2170 if (!hci_connection) { 2171 // 2172 log_error("no hci_connection for handle %u", handle); 2173 return; 2174 } 2175 2176 // alloc structure 2177 // log_info("l2cap_handle_connection_request register channel"); 2178 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 2179 psm, service->mtu, service->required_security_level); 2180 if (!channel){ 2181 // 0x0004 No resources available 2182 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 2183 return; 2184 } 2185 2186 channel->con_handle = handle; 2187 channel->remote_cid = source_cid; 2188 channel->remote_sig_id = sig_id; 2189 2190 // limit local mtu to max acl packet length - l2cap header 2191 if (channel->local_mtu > l2cap_max_mtu()) { 2192 channel->local_mtu = l2cap_max_mtu(); 2193 } 2194 2195 // set initial state 2196 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 2197 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND | L2CAP_CHANNEL_STATE_VAR_INCOMING); 2198 2199 // add to connections list 2200 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 2201 2202 // assert security requirements 2203 gap_request_security_level(handle, channel->required_security_level); 2204 } 2205 2206 void l2cap_accept_connection(uint16_t local_cid){ 2207 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 2208 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 2209 if (!channel) { 2210 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 2211 return; 2212 } 2213 2214 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2215 // configure L2CAP Basic mode 2216 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2217 #endif 2218 2219 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 2220 2221 // process 2222 l2cap_run(); 2223 } 2224 2225 void l2cap_decline_connection(uint16_t local_cid){ 2226 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 2227 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 2228 if (!channel) { 2229 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 2230 return; 2231 } 2232 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 2233 channel->reason = 0x04; // no resources available 2234 l2cap_run(); 2235 } 2236 2237 // @pre command len is valid, see check in l2cap_signaling_handler_channel 2238 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 2239 2240 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2241 2242 uint16_t flags = little_endian_read_16(command, 6); 2243 if (flags & 1) { 2244 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 2245 } 2246 2247 // accept the other's configuration options 2248 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2249 uint16_t pos = 8; 2250 while (pos < end_pos){ 2251 uint8_t option_hint = command[pos] >> 7; 2252 uint8_t option_type = command[pos] & 0x7f; 2253 // log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 2254 pos++; 2255 uint8_t length = command[pos++]; 2256 // MTU { type(8): 1, len(8):2, MTU(16) } 2257 if (option_type == L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT && length == 2){ 2258 channel->remote_mtu = little_endian_read_16(command, pos); 2259 log_info("Remote MTU %u", channel->remote_mtu); 2260 if (channel->remote_mtu > l2cap_max_mtu()){ 2261 log_info("Remote MTU %u larger than outgoing buffer, only using MTU = %u", channel->remote_mtu, l2cap_max_mtu()); 2262 channel->remote_mtu = l2cap_max_mtu(); 2263 } 2264 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 2265 } 2266 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 2267 if (option_type == L2CAP_CONFIG_OPTION_TYPE_FLUSH_TIMEOUT && length == 2){ 2268 channel->flush_timeout = little_endian_read_16(command, pos); 2269 log_info("Flush timeout: %u ms", channel->flush_timeout); 2270 } 2271 2272 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2273 // Retransmission and Flow Control Option 2274 if (option_type == L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL && length == 9){ 2275 l2cap_channel_mode_t mode = (l2cap_channel_mode_t) command[pos]; 2276 switch(channel->mode){ 2277 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 2278 // Store remote config 2279 channel->remote_tx_window_size = command[pos+1]; 2280 channel->remote_max_transmit = command[pos+2]; 2281 channel->remote_retransmission_timeout_ms = little_endian_read_16(command, pos + 3); 2282 channel->remote_monitor_timeout_ms = little_endian_read_16(command, pos + 5); 2283 channel->remote_mps = little_endian_read_16(command, pos + 7); 2284 log_info("FC&C config: tx window: %u, max transmit %u, retrans timeout %u, monitor timeout %u, mps %u", 2285 channel->remote_tx_window_size, 2286 channel->remote_max_transmit, 2287 channel->remote_retransmission_timeout_ms, 2288 channel->remote_monitor_timeout_ms, 2289 channel->remote_mps); 2290 // If ERTM mandatory, but remote doens't offer ERTM -> disconnect 2291 if (channel->ertm_mandatory && mode != L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 2292 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2293 } else { 2294 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 2295 } 2296 break; 2297 case L2CAP_CHANNEL_MODE_BASIC: 2298 switch (mode){ 2299 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 2300 // remote asks for ERTM, but we want basic mode. disconnect if this happens a second time 2301 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED){ 2302 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2303 } 2304 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_BASIC_FALLBACK_TRIED); 2305 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_REJECTED); 2306 break; 2307 default: // case L2CAP_CHANNEL_MODE_BASIC: 2308 // TODO store and evaluate configuration 2309 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 2310 break; 2311 } 2312 break; 2313 default: 2314 break; 2315 } 2316 } 2317 if (option_type == L2CAP_CONFIG_OPTION_TYPE_FRAME_CHECK_SEQUENCE && length == 1){ 2318 // "FCS" has precedence over "No FCS" 2319 if (command[pos] != 0){ 2320 log_info("ertm: accept remote request for FCS"); 2321 channel->fcs_option = 1; 2322 } 2323 } 2324 #endif 2325 // check for unknown options 2326 if (option_hint == 0 && (option_type < L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT || option_type > L2CAP_CONFIG_OPTION_TYPE_EXTENDED_WINDOW_SIZE)){ 2327 log_info("l2cap cid %u, unknown options", channel->local_cid); 2328 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 2329 } 2330 pos += length; 2331 } 2332 } 2333 2334 // @pre command len is valid, see check in l2cap_signaling_handler_channel 2335 static void l2cap_signaling_handle_configure_response(l2cap_channel_t *channel, uint8_t result, uint8_t *command){ 2336 log_info("l2cap_signaling_handle_configure_response"); 2337 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2338 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2339 uint16_t pos = 10; 2340 while (pos < end_pos){ 2341 uint8_t option_hint = command[pos] >> 7; 2342 uint8_t option_type = command[pos] & 0x7f; 2343 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 2344 pos++; 2345 uint8_t length = command[pos++]; 2346 2347 // Retransmission and Flow Control Option 2348 if (option_type == L2CAP_CONFIG_OPTION_TYPE_RETRANSMISSION_AND_FLOW_CONTROL && length == 9){ 2349 switch (channel->mode){ 2350 case L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION: 2351 if (channel->ertm_mandatory){ 2352 // ?? 2353 } else { 2354 // On 'Reject - Unacceptable Parameters' to our optional ERTM request, fall back to BASIC mode 2355 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 2356 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2357 } 2358 } 2359 break; 2360 case L2CAP_CHANNEL_MODE_BASIC: 2361 if (result == L2CAP_CONF_RESULT_UNACCEPTABLE_PARAMETERS){ 2362 // On 'Reject - Unacceptable Parameters' to our Basic mode request, disconnect 2363 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2364 } 2365 break; 2366 default: 2367 break; 2368 } 2369 } 2370 2371 // check for unknown options 2372 if (option_hint == 0 && (option_type < L2CAP_CONFIG_OPTION_TYPE_MAX_TRANSMISSION_UNIT || option_type > L2CAP_CONFIG_OPTION_TYPE_EXTENDED_WINDOW_SIZE)){ 2373 log_info("l2cap cid %u, unknown options", channel->local_cid); 2374 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 2375 } 2376 2377 pos += length; 2378 } 2379 #else 2380 UNUSED(channel); // ok: no code 2381 UNUSED(result); // ok: no code 2382 UNUSED(command); // ok: no code 2383 #endif 2384 } 2385 2386 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 2387 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 2388 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 2389 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 2390 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 2391 if (channel->state == L2CAP_STATE_OPEN) return 0; 2392 return 1; 2393 } 2394 2395 2396 // @pre command len is valid, see check in l2cap_signaling_handler_dispatch 2397 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 2398 2399 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2400 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2401 uint16_t cmd_len = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2402 uint16_t result = 0; 2403 2404 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 2405 2406 // handle DISCONNECT REQUESTS seperately 2407 if (code == DISCONNECTION_REQUEST){ 2408 switch (channel->state){ 2409 case L2CAP_STATE_CONFIG: 2410 case L2CAP_STATE_OPEN: 2411 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 2412 case L2CAP_STATE_WAIT_DISCONNECT: 2413 l2cap_handle_disconnect_request(channel, identifier); 2414 break; 2415 2416 default: 2417 // ignore in other states 2418 break; 2419 } 2420 return; 2421 } 2422 2423 // @STATEMACHINE(l2cap) 2424 switch (channel->state) { 2425 2426 case L2CAP_STATE_WAIT_CONNECT_RSP: 2427 switch (code){ 2428 case CONNECTION_RESPONSE: 2429 if (cmd_len < 8){ 2430 // command imcomplete 2431 l2cap_register_signaling_response(channel->con_handle, COMMAND_REJECT, identifier, 0, L2CAP_REJ_CMD_UNKNOWN); 2432 break; 2433 } 2434 l2cap_stop_rtx(channel); 2435 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2436 switch (result) { 2437 case 0: 2438 // successful connection 2439 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2440 channel->state = L2CAP_STATE_CONFIG; 2441 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 2442 break; 2443 case 1: 2444 // connection pending. get some coffee, but start the ERTX 2445 l2cap_start_ertx(channel); 2446 break; 2447 default: 2448 // channel closed 2449 channel->state = L2CAP_STATE_CLOSED; 2450 // map l2cap connection response result to BTstack status enumeration 2451 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 2452 2453 // drop link key if security block 2454 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 2455 gap_drop_link_key_for_bd_addr(channel->address); 2456 } 2457 2458 // discard channel 2459 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2460 btstack_memory_l2cap_channel_free(channel); 2461 break; 2462 } 2463 break; 2464 2465 default: 2466 //@TODO: implement other signaling packets 2467 break; 2468 } 2469 break; 2470 2471 case L2CAP_STATE_CONFIG: 2472 switch (code) { 2473 case CONFIGURE_REQUEST: 2474 if (cmd_len < 4){ 2475 // command incomplete 2476 l2cap_register_signaling_response(channel->con_handle, COMMAND_REJECT, identifier, 0, L2CAP_REJ_CMD_UNKNOWN); 2477 break; 2478 } 2479 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 2480 l2cap_signaling_handle_configure_request(channel, command); 2481 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 2482 // only done if continuation not set 2483 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 2484 } 2485 break; 2486 case CONFIGURE_RESPONSE: 2487 if (cmd_len < 6){ 2488 // command incomplete 2489 l2cap_register_signaling_response(channel->con_handle, COMMAND_REJECT, identifier, 0, L2CAP_REJ_CMD_UNKNOWN); 2490 break; 2491 } 2492 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2493 l2cap_stop_rtx(channel); 2494 l2cap_signaling_handle_configure_response(channel, result, command); 2495 switch (result){ 2496 case 0: // success 2497 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 2498 break; 2499 case 4: // pending 2500 l2cap_start_ertx(channel); 2501 break; 2502 default: 2503 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2504 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION && channel->ertm_mandatory){ 2505 // remote does not offer ertm but it's required 2506 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2507 break; 2508 } 2509 #endif 2510 // retry on negative result 2511 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 2512 break; 2513 } 2514 break; 2515 default: 2516 break; 2517 } 2518 if (l2cap_channel_ready_for_open(channel)){ 2519 // for open: 2520 channel->state = L2CAP_STATE_OPEN; 2521 l2cap_emit_channel_opened(channel, 0); 2522 } 2523 break; 2524 2525 case L2CAP_STATE_WAIT_DISCONNECT: 2526 switch (code) { 2527 case DISCONNECTION_RESPONSE: 2528 l2cap_finialize_channel_close(channel); 2529 break; 2530 default: 2531 //@TODO: implement other signaling packets 2532 break; 2533 } 2534 break; 2535 2536 case L2CAP_STATE_CLOSED: 2537 // @TODO handle incoming requests 2538 break; 2539 2540 case L2CAP_STATE_OPEN: 2541 //@TODO: implement other signaling packets, e.g. re-configure 2542 break; 2543 default: 2544 break; 2545 } 2546 // log_info("new state %u", channel->state); 2547 } 2548 2549 2550 // @pre command len is valid, see check in l2cap_acl_classic_handler 2551 static void l2cap_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command){ 2552 2553 btstack_linked_list_iterator_t it; 2554 2555 // get code, signalind identifier and command len 2556 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2557 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 2558 uint16_t cmd_len = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2559 2560 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_RESPONSE 2561 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_RESPONSE){ 2562 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2563 return; 2564 } 2565 2566 // general commands without an assigned channel 2567 switch(code) { 2568 2569 case CONNECTION_REQUEST: 2570 if (cmd_len == 4){ 2571 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2572 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2573 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 2574 } else { 2575 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2576 } 2577 return; 2578 2579 case ECHO_REQUEST: 2580 l2cap_register_signaling_response(handle, code, sig_id, 0, 0); 2581 return; 2582 2583 case INFORMATION_REQUEST: 2584 if (cmd_len == 2) { 2585 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2586 l2cap_register_signaling_response(handle, code, sig_id, 0, info_type); 2587 } else { 2588 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2589 } 2590 return; 2591 2592 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 2593 case INFORMATION_RESPONSE: { 2594 hci_connection_t * connection = hci_connection_for_handle(handle); 2595 if (!connection) return; 2596 if (cmd_len >= 4) { 2597 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2598 uint16_t result = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 2599 if (result != 0) return; 2600 if (info_type != L2CAP_INFO_TYPE_EXTENDED_FEATURES_SUPPORTED) return; 2601 if (cmd_len >= 6) { 2602 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_DONE; 2603 connection->l2cap_state.extended_feature_mask = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 2604 log_info("extended features mask 0x%02x", connection->l2cap_state.extended_feature_mask); 2605 // trigger connection request 2606 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2607 while (btstack_linked_list_iterator_has_next(&it)){ 2608 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2609 if (channel->con_handle != handle) continue; 2610 // bail if ERTM was requested but is not supported 2611 if ((channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION) && ((connection->l2cap_state.extended_feature_mask & 0x08) == 0)){ 2612 if (channel->ertm_mandatory){ 2613 // channel closed 2614 channel->state = L2CAP_STATE_CLOSED; 2615 // map l2cap connection response result to BTstack status enumeration 2616 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_ERTM_NOT_SUPPORTED); 2617 // discard channel 2618 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2619 btstack_memory_l2cap_channel_free(channel); 2620 continue; 2621 } else { 2622 // fallback to Basic mode 2623 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 2624 } 2625 } 2626 // start connecting 2627 if (channel->state == L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES){ 2628 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 2629 } 2630 // respond to connection request 2631 if (channel->state == L2CAP_STATE_WAIT_INCOMING_EXTENDED_FEATURES){ 2632 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2633 l2cap_emit_incoming_connection(channel); 2634 } 2635 } 2636 return; // cmd len valid 2637 } 2638 } 2639 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2640 return; 2641 } 2642 #endif 2643 2644 default: 2645 break; 2646 } 2647 2648 // Get potential destination CID 2649 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 2650 2651 // Find channel for this sig_id and connection handle 2652 btstack_linked_list_iterator_init(&it, &l2cap_channels); 2653 while (btstack_linked_list_iterator_has_next(&it)){ 2654 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2655 if (channel->con_handle != handle) continue; 2656 if (code & 1) { 2657 // match odd commands (responses) by previous signaling identifier 2658 if (channel->local_sig_id == sig_id) { 2659 l2cap_signaling_handler_channel(channel, command); 2660 break; 2661 } 2662 } else { 2663 // match even commands (requests) by local channel id 2664 if (channel->local_cid == dest_cid) { 2665 l2cap_signaling_handler_channel(channel, command); 2666 break; 2667 } 2668 } 2669 } 2670 } 2671 #endif 2672 2673 #ifdef ENABLE_BLE 2674 2675 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 2676 uint8_t event[6]; 2677 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 2678 event[1] = 4; 2679 little_endian_store_16(event, 2, con_handle); 2680 little_endian_store_16(event, 4, result); 2681 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2682 if (!l2cap_event_packet_handler) return; 2683 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 2684 } 2685 2686 // @returns valid 2687 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 2688 hci_connection_t * connection; 2689 uint16_t result; 2690 uint8_t event[10]; 2691 2692 #ifdef ENABLE_LE_DATA_CHANNELS 2693 btstack_linked_list_iterator_t it; 2694 l2cap_channel_t * channel; 2695 uint16_t local_cid; 2696 uint16_t le_psm; 2697 uint16_t new_credits; 2698 uint16_t credits_before; 2699 l2cap_service_t * service; 2700 uint16_t source_cid; 2701 #endif 2702 2703 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 2704 uint16_t len = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2705 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u, len %u", code, sig_id, len); 2706 2707 switch (code){ 2708 2709 case CONNECTION_PARAMETER_UPDATE_REQUEST: 2710 // check size 2711 if (len < 8) return 0; 2712 connection = hci_connection_for_handle(handle); 2713 if (connection){ 2714 if (connection->role != HCI_ROLE_MASTER){ 2715 // reject command without notifying upper layer when not in master role 2716 return 0; 2717 } 2718 int update_parameter = 1; 2719 le_connection_parameter_range_t existing_range; 2720 gap_get_connection_parameter_range(&existing_range); 2721 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 2722 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 2723 uint16_t le_conn_latency = little_endian_read_16(command,12); 2724 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 2725 2726 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 2727 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 2728 2729 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 2730 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 2731 2732 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 2733 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 2734 2735 if (update_parameter){ 2736 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 2737 connection->le_conn_interval_min = le_conn_interval_min; 2738 connection->le_conn_interval_max = le_conn_interval_max; 2739 connection->le_conn_latency = le_conn_latency; 2740 connection->le_supervision_timeout = le_supervision_timeout; 2741 } else { 2742 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 2743 } 2744 connection->le_con_param_update_identifier = sig_id; 2745 } 2746 2747 if (!l2cap_event_packet_handler) break; 2748 2749 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 2750 event[1] = 8; 2751 memcpy(&event[2], &command[4], 8); 2752 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2753 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2754 break; 2755 2756 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 2757 // check size 2758 if (len < 2) return 0; 2759 result = little_endian_read_16(command, 4); 2760 l2cap_emit_connection_parameter_update_response(handle, result); 2761 break; 2762 2763 #ifdef ENABLE_LE_DATA_CHANNELS 2764 2765 case COMMAND_REJECT: 2766 // Find channel for this sig_id and connection handle 2767 channel = NULL; 2768 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2769 while (btstack_linked_list_iterator_has_next(&it)){ 2770 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2771 if (a_channel->con_handle != handle) continue; 2772 if (a_channel->local_sig_id != sig_id) continue; 2773 channel = a_channel; 2774 break; 2775 } 2776 if (!channel) break; 2777 2778 // if received while waiting for le connection response, assume legacy device 2779 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 2780 channel->state = L2CAP_STATE_CLOSED; 2781 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 2782 l2cap_emit_le_channel_opened(channel, 0x0002); 2783 2784 // discard channel 2785 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2786 btstack_memory_l2cap_channel_free(channel); 2787 break; 2788 } 2789 break; 2790 2791 case LE_CREDIT_BASED_CONNECTION_REQUEST: 2792 // check size 2793 if (len < 10) return 0; 2794 2795 // get hci connection, bail if not found (must not happen) 2796 connection = hci_connection_for_handle(handle); 2797 if (!connection) return 0; 2798 2799 // check if service registered 2800 le_psm = little_endian_read_16(command, 4); 2801 service = l2cap_le_get_service(le_psm); 2802 source_cid = little_endian_read_16(command, 6); 2803 2804 if (service){ 2805 if (source_cid < 0x40){ 2806 // 0x0009 Connection refused - Invalid Source CID 2807 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0009); 2808 return 1; 2809 } 2810 2811 // go through list of channels for this ACL connection and check if we get a match 2812 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2813 while (btstack_linked_list_iterator_has_next(&it)){ 2814 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2815 if (a_channel->con_handle != handle) continue; 2816 if (a_channel->remote_cid != source_cid) continue; 2817 // 0x000a Connection refused - Source CID already allocated 2818 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x000a); 2819 return 1; 2820 } 2821 2822 // security: check encryption 2823 if (service->required_security_level >= LEVEL_2){ 2824 if (sm_encryption_key_size(handle) == 0){ 2825 // 0x0008 Connection refused - insufficient encryption 2826 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0008); 2827 return 1; 2828 } 2829 // anything less than 16 byte key size is insufficient 2830 if (sm_encryption_key_size(handle) < 16){ 2831 // 0x0007 Connection refused – insufficient encryption key size 2832 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0007); 2833 return 1; 2834 } 2835 } 2836 2837 // security: check authencation 2838 if (service->required_security_level >= LEVEL_3){ 2839 if (!sm_authenticated(handle)){ 2840 // 0x0005 Connection refused – insufficient authentication 2841 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0005); 2842 return 1; 2843 } 2844 } 2845 2846 // security: check authorization 2847 if (service->required_security_level >= LEVEL_4){ 2848 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 2849 // 0x0006 Connection refused – insufficient authorization 2850 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0006); 2851 return 1; 2852 } 2853 } 2854 2855 // allocate channel 2856 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 2857 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 2858 if (!channel){ 2859 // 0x0004 Connection refused – no resources available 2860 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 2861 return 1; 2862 } 2863 2864 channel->con_handle = handle; 2865 channel->remote_cid = source_cid; 2866 channel->remote_sig_id = sig_id; 2867 channel->remote_mtu = little_endian_read_16(command, 8); 2868 channel->remote_mps = little_endian_read_16(command, 10); 2869 channel->credits_outgoing = little_endian_read_16(command, 12); 2870 2871 // set initial state 2872 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2873 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 2874 2875 // add to connections list 2876 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2877 2878 // post connection request event 2879 l2cap_emit_le_incoming_connection(channel); 2880 2881 } else { 2882 // Connection refused – LE_PSM not supported 2883 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 2884 } 2885 break; 2886 2887 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 2888 // check size 2889 if (len < 10) return 0; 2890 2891 // Find channel for this sig_id and connection handle 2892 channel = NULL; 2893 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2894 while (btstack_linked_list_iterator_has_next(&it)){ 2895 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2896 if (a_channel->con_handle != handle) continue; 2897 if (a_channel->local_sig_id != sig_id) continue; 2898 channel = a_channel; 2899 break; 2900 } 2901 if (!channel) break; 2902 2903 // cid + 0 2904 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 2905 if (result){ 2906 channel->state = L2CAP_STATE_CLOSED; 2907 // map l2cap connection response result to BTstack status enumeration 2908 l2cap_emit_le_channel_opened(channel, result); 2909 2910 // discard channel 2911 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2912 btstack_memory_l2cap_channel_free(channel); 2913 break; 2914 } 2915 2916 // success 2917 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2918 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2919 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 2920 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 2921 channel->state = L2CAP_STATE_OPEN; 2922 l2cap_emit_le_channel_opened(channel, result); 2923 break; 2924 2925 case LE_FLOW_CONTROL_CREDIT: 2926 // check size 2927 if (len < 4) return 0; 2928 2929 // find channel 2930 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2931 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2932 if (!channel) { 2933 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2934 break; 2935 } 2936 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2937 credits_before = channel->credits_outgoing; 2938 channel->credits_outgoing += new_credits; 2939 // check for credit overrun 2940 if (credits_before > channel->credits_outgoing){ 2941 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 2942 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2943 break; 2944 } 2945 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 2946 break; 2947 2948 case DISCONNECTION_REQUEST: 2949 2950 // check size 2951 if (len < 4) return 0; 2952 2953 // find channel 2954 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2955 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2956 if (!channel) { 2957 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2958 break; 2959 } 2960 channel->remote_sig_id = sig_id; 2961 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 2962 break; 2963 2964 #endif 2965 2966 case DISCONNECTION_RESPONSE: 2967 break; 2968 2969 default: 2970 // command unknown -> reject command 2971 return 0; 2972 } 2973 return 1; 2974 } 2975 #endif 2976 2977 static void l2cap_acl_classic_handler(hci_con_handle_t handle, uint8_t *packet, uint16_t size){ 2978 #ifdef ENABLE_CLASSIC 2979 l2cap_channel_t * l2cap_channel; 2980 2981 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 2982 switch (channel_id) { 2983 2984 case L2CAP_CID_SIGNALING: { 2985 uint16_t command_offset = 8; 2986 while (command_offset < size) { 2987 // assert signaling command is fully inside packet 2988 uint16_t data_len = little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2989 uint32_t next_command_offset = ((uint32_t) command_offset) + L2CAP_SIGNALING_COMMAND_DATA_OFFSET + data_len; 2990 if (next_command_offset > size){ 2991 log_error("l2cap signaling command len invalid -> drop"); 2992 break; 2993 } 2994 // handle signaling command 2995 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 2996 // go to next command 2997 command_offset = (uint16_t) next_command_offset; 2998 } 2999 break; 3000 } 3001 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 3002 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 3003 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 3004 } 3005 break; 3006 3007 default: 3008 // Find channel for this channel_id and connection handle 3009 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 3010 if (l2cap_channel) { 3011 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 3012 if (l2cap_channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 3013 3014 int fcs_size = l2cap_channel->fcs_option ? 2 : 0; 3015 3016 // assert control + FCS fields are inside 3017 if (size < COMPLETE_L2CAP_HEADER+2+fcs_size) break; 3018 3019 if (l2cap_channel->fcs_option){ 3020 // verify FCS (required if one side requests it and BTstack does) 3021 uint16_t fcs_calculated = crc16_calc(&packet[4], size - (4+2)); 3022 uint16_t fcs_packet = little_endian_read_16(packet, size-2); 3023 if (fcs_calculated == fcs_packet){ 3024 log_info("Packet FCS 0x%04x verified", fcs_packet); 3025 } else { 3026 log_error("FCS mismatch! Packet 0x%04x, calculated 0x%04x", fcs_packet, fcs_calculated); 3027 // TODO: trigger retransmission or something like that 3028 break; 3029 } 3030 } 3031 3032 // switch on packet type 3033 uint16_t control = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 3034 uint8_t req_seq = (control >> 8) & 0x3f; 3035 int final = (control >> 7) & 0x01; 3036 if (control & 1){ 3037 // S-Frame 3038 int poll = (control >> 4) & 0x01; 3039 l2cap_supervisory_function_t s = (l2cap_supervisory_function_t) ((control >> 2) & 0x03); 3040 log_info("Control: 0x%04x => Supervisory function %u, ReqSeq %02u", control, (int) s, req_seq); 3041 l2cap_ertm_tx_packet_state_t * tx_state; 3042 switch (s){ 3043 case L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY: 3044 log_info("L2CAP_SUPERVISORY_FUNCTION_RR_RECEIVER_READY"); 3045 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 3046 if (poll && final){ 3047 // S-frames shall not be transmitted with both the F-bit and the P-bit set to 1 at the same time. 3048 log_error("P=F=1 in S-Frame"); 3049 break; 3050 } 3051 if (poll){ 3052 // check if we did request selective retransmission before <==> we have stored SDU segments 3053 int i; 3054 int num_stored_out_of_order_packets = 0; 3055 for (i=0;i<l2cap_channel->num_rx_buffers;i++){ 3056 int index = l2cap_channel->rx_store_index + i; 3057 if (index >= l2cap_channel->num_rx_buffers){ 3058 index -= l2cap_channel->num_rx_buffers; 3059 } 3060 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 3061 if (!rx_state->valid) continue; 3062 num_stored_out_of_order_packets++; 3063 } 3064 if (num_stored_out_of_order_packets){ 3065 l2cap_channel->send_supervisor_frame_selective_reject = 1; 3066 } else { 3067 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 3068 } 3069 l2cap_channel->set_final_bit_after_packet_with_poll_bit_set = 1; 3070 } 3071 if (final){ 3072 // Stop-MonitorTimer 3073 l2cap_ertm_stop_monitor_timer(l2cap_channel); 3074 // If UnackedFrames > 0 then Start-RetransTimer 3075 if (l2cap_channel->unacked_frames){ 3076 l2cap_ertm_start_retransmission_timer(l2cap_channel); 3077 } 3078 3079 // final bit set <- response to RR with poll bit set. All not acknowledged packets need to be retransmitted 3080 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 3081 } 3082 break; 3083 case L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT: 3084 log_info("L2CAP_SUPERVISORY_FUNCTION_REJ_REJECT"); 3085 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 3086 // rsetart transmittion from last unacknowledted packet (earlier packets already freed in l2cap_ertm_process_req_seq) 3087 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 3088 break; 3089 case L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY: 3090 log_error("L2CAP_SUPERVISORY_FUNCTION_RNR_RECEIVER_NOT_READY"); 3091 break; 3092 case L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT: 3093 log_info("L2CAP_SUPERVISORY_FUNCTION_SREJ_SELECTIVE_REJECT"); 3094 if (poll){ 3095 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 3096 } 3097 // find requested i-frame 3098 tx_state = l2cap_ertm_get_tx_state(l2cap_channel, req_seq); 3099 if (tx_state){ 3100 log_info("Retransmission for tx_seq %u requested", req_seq); 3101 l2cap_channel->set_final_bit_after_packet_with_poll_bit_set = poll; 3102 tx_state->retransmission_requested = 1; 3103 l2cap_channel->srej_active = 1; 3104 } 3105 break; 3106 default: 3107 break; 3108 } 3109 break; 3110 } else { 3111 // I-Frame 3112 // get control 3113 l2cap_segmentation_and_reassembly_t sar = (l2cap_segmentation_and_reassembly_t) (control >> 14); 3114 uint8_t tx_seq = (control >> 1) & 0x3f; 3115 log_info("Control: 0x%04x => SAR %u, ReqSeq %02u, R?, TxSeq %02u", control, (int) sar, req_seq, tx_seq); 3116 log_info("SAR: pos %u", l2cap_channel->reassembly_pos); 3117 log_info("State: expected_tx_seq %02u, req_seq %02u", l2cap_channel->expected_tx_seq, l2cap_channel->req_seq); 3118 l2cap_ertm_process_req_seq(l2cap_channel, req_seq); 3119 if (final){ 3120 // final bit set <- response to RR with poll bit set. All not acknowledged packets need to be retransmitted 3121 l2cap_channel->tx_send_index = l2cap_channel->tx_read_index; 3122 } 3123 3124 // get SDU 3125 const uint8_t * sdu_data = &packet[COMPLETE_L2CAP_HEADER+2]; 3126 uint16_t sdu_len = size-(COMPLETE_L2CAP_HEADER+2+fcs_size); 3127 3128 // assert SDU size is smaller or equal to our buffers 3129 if (sdu_len > l2cap_channel->local_mps) break; 3130 3131 // check ordering 3132 if (l2cap_channel->expected_tx_seq == tx_seq){ 3133 log_info("Received expected frame with TxSeq == ExpectedTxSeq == %02u", tx_seq); 3134 l2cap_channel->expected_tx_seq = l2cap_next_ertm_seq_nr(l2cap_channel->expected_tx_seq); 3135 l2cap_channel->req_seq = l2cap_channel->expected_tx_seq; 3136 3137 // process SDU 3138 l2cap_ertm_handle_in_sequence_sdu(l2cap_channel, sar, sdu_data, sdu_len); 3139 3140 // process stored segments 3141 while (1){ 3142 int index = l2cap_channel->rx_store_index; 3143 l2cap_ertm_rx_packet_state_t * rx_state = &l2cap_channel->rx_packets_state[index]; 3144 if (!rx_state->valid) break; 3145 3146 log_info("Processing stored frame with TxSeq == ExpectedTxSeq == %02u", l2cap_channel->expected_tx_seq); 3147 l2cap_channel->expected_tx_seq = l2cap_next_ertm_seq_nr(l2cap_channel->expected_tx_seq); 3148 l2cap_channel->req_seq = l2cap_channel->expected_tx_seq; 3149 3150 rx_state->valid = 0; 3151 l2cap_ertm_handle_in_sequence_sdu(l2cap_channel, rx_state->sar, &l2cap_channel->rx_packets_data[index], rx_state->len); 3152 3153 // update rx store index 3154 index++; 3155 if (index >= l2cap_channel->num_rx_buffers){ 3156 index = 0; 3157 } 3158 l2cap_channel->rx_store_index = index; 3159 } 3160 3161 // 3162 l2cap_channel->send_supervisor_frame_receiver_ready = 1; 3163 3164 } else { 3165 int delta = (tx_seq - l2cap_channel->expected_tx_seq) & 0x3f; 3166 if (delta < 2){ 3167 // store segment 3168 l2cap_ertm_handle_out_of_sequence_sdu(l2cap_channel, sar, delta, sdu_data, sdu_len); 3169 3170 log_info("Received unexpected frame TxSeq %u but expected %u -> send S-SREJ", tx_seq, l2cap_channel->expected_tx_seq); 3171 l2cap_channel->send_supervisor_frame_selective_reject = 1; 3172 } else { 3173 log_info("Received unexpected frame TxSeq %u but expected %u -> send S-REJ", tx_seq, l2cap_channel->expected_tx_seq); 3174 l2cap_channel->send_supervisor_frame_reject = 1; 3175 } 3176 } 3177 } 3178 break; 3179 } 3180 #endif 3181 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 3182 } 3183 break; 3184 } 3185 #else 3186 UNUSED(handle); // ok: no code 3187 UNUSED(packet); // ok: no code 3188 UNUSED(size); // ok: no code 3189 #endif 3190 } 3191 3192 static void l2cap_acl_le_handler(hci_con_handle_t handle, uint8_t *packet, uint16_t size){ 3193 #ifdef ENABLE_BLE 3194 3195 #ifdef ENABLE_LE_DATA_CHANNELS 3196 l2cap_channel_t * l2cap_channel; 3197 #endif 3198 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 3199 switch (channel_id) { 3200 3201 case L2CAP_CID_SIGNALING_LE: { 3202 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 3203 uint16_t len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER + 2); 3204 if (COMPLETE_L2CAP_HEADER + 4 + len > size) break; 3205 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 3206 if (!valid){ 3207 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 3208 } 3209 break; 3210 } 3211 3212 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 3213 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 3214 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 3215 } 3216 break; 3217 3218 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 3219 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 3220 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 3221 } 3222 break; 3223 3224 default: 3225 3226 #ifdef ENABLE_LE_DATA_CHANNELS 3227 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 3228 if (l2cap_channel) { 3229 // credit counting 3230 if (l2cap_channel->credits_incoming == 0){ 3231 log_error("LE Data Channel packet received but no incoming credits"); 3232 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3233 break; 3234 } 3235 l2cap_channel->credits_incoming--; 3236 3237 // automatic credits 3238 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 3239 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 3240 } 3241 3242 // first fragment 3243 uint16_t pos = 0; 3244 if (!l2cap_channel->receive_sdu_len){ 3245 uint16_t sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 3246 if(sdu_len > l2cap_channel->local_mtu) break; // SDU would be larger than our buffer 3247 l2cap_channel->receive_sdu_len = sdu_len; 3248 l2cap_channel->receive_sdu_pos = 0; 3249 pos += 2; 3250 size -= 2; 3251 } 3252 uint16_t fragment_size = size-COMPLETE_L2CAP_HEADER; 3253 uint16_t remaining_space = l2cap_channel->local_mtu - l2cap_channel->receive_sdu_pos; 3254 if (fragment_size > remaining_space) break; // SDU would cause buffer overrun 3255 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], fragment_size); 3256 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 3257 // done? 3258 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 3259 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 3260 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 3261 l2cap_channel->receive_sdu_len = 0; 3262 } 3263 } else { 3264 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 3265 } 3266 #endif 3267 break; 3268 } 3269 #else 3270 UNUSED(handle); // ok: no code 3271 UNUSED(packet); // ok: no code 3272 UNUSED(size); // ok: no code 3273 #endif 3274 } 3275 3276 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 3277 UNUSED(packet_type); // ok: registered with hci_register_acl_packet_handler 3278 UNUSED(channel); // ok: there is no channel 3279 3280 // Assert full L2CAP header present 3281 if (size < COMPLETE_L2CAP_HEADER) return; 3282 3283 // Dispatch to Classic or LE handler 3284 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 3285 hci_connection_t *conn = hci_connection_for_handle(handle); 3286 if (!conn) return; 3287 if (conn->address_type == BD_ADDR_TYPE_CLASSIC){ 3288 l2cap_acl_classic_handler(handle, packet, size); 3289 } else { 3290 l2cap_acl_le_handler(handle, packet, size); 3291 } 3292 3293 l2cap_run(); 3294 } 3295 3296 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 3297 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 3298 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 3299 if (index < 0) return; 3300 fixed_channels[index].callback = the_packet_handler; 3301 } 3302 3303 #ifdef ENABLE_CLASSIC 3304 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 3305 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 3306 channel->state = L2CAP_STATE_CLOSED; 3307 l2cap_emit_channel_closed(channel); 3308 // discard channel 3309 l2cap_stop_rtx(channel); 3310 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 3311 btstack_memory_l2cap_channel_free(channel); 3312 } 3313 3314 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 3315 btstack_linked_list_iterator_t it; 3316 btstack_linked_list_iterator_init(&it, services); 3317 while (btstack_linked_list_iterator_has_next(&it)){ 3318 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 3319 if ( service->psm == psm){ 3320 return service; 3321 }; 3322 } 3323 return NULL; 3324 } 3325 3326 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 3327 return l2cap_get_service_internal(&l2cap_services, psm); 3328 } 3329 3330 3331 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 3332 3333 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 3334 3335 // check for alread registered psm 3336 l2cap_service_t *service = l2cap_get_service(psm); 3337 if (service) { 3338 log_error("l2cap_register_service: PSM %u already registered", psm); 3339 return L2CAP_SERVICE_ALREADY_REGISTERED; 3340 } 3341 3342 // alloc structure 3343 service = btstack_memory_l2cap_service_get(); 3344 if (!service) { 3345 log_error("l2cap_register_service: no memory for l2cap_service_t"); 3346 return BTSTACK_MEMORY_ALLOC_FAILED; 3347 } 3348 3349 // fill in 3350 service->psm = psm; 3351 service->mtu = mtu; 3352 service->packet_handler = service_packet_handler; 3353 service->required_security_level = security_level; 3354 3355 // add to services list 3356 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 3357 3358 // enable page scan 3359 gap_connectable_control(1); 3360 3361 return 0; 3362 } 3363 3364 uint8_t l2cap_unregister_service(uint16_t psm){ 3365 3366 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 3367 3368 l2cap_service_t *service = l2cap_get_service(psm); 3369 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 3370 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 3371 btstack_memory_l2cap_service_free(service); 3372 3373 // disable page scan when no services registered 3374 if (btstack_linked_list_empty(&l2cap_services)) { 3375 gap_connectable_control(0); 3376 } 3377 return 0; 3378 } 3379 #endif 3380 3381 3382 #ifdef ENABLE_LE_DATA_CHANNELS 3383 3384 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 3385 if (!channel->waiting_for_can_send_now) return; 3386 if (channel->send_sdu_buffer) return; 3387 channel->waiting_for_can_send_now = 0; 3388 log_info("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 3389 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 3390 } 3391 3392 // 1BH2222 3393 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 3394 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", 3395 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 3396 uint8_t event[19]; 3397 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 3398 event[1] = sizeof(event) - 2; 3399 event[2] = channel->address_type; 3400 reverse_bd_addr(channel->address, &event[3]); 3401 little_endian_store_16(event, 9, channel->con_handle); 3402 little_endian_store_16(event, 11, channel->psm); 3403 little_endian_store_16(event, 13, channel->local_cid); 3404 little_endian_store_16(event, 15, channel->remote_cid); 3405 little_endian_store_16(event, 17, channel->remote_mtu); 3406 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 3407 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 3408 } 3409 // 11BH22222 3410 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 3411 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", 3412 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 3413 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 3414 uint8_t event[23]; 3415 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 3416 event[1] = sizeof(event) - 2; 3417 event[2] = status; 3418 event[3] = channel->address_type; 3419 reverse_bd_addr(channel->address, &event[4]); 3420 little_endian_store_16(event, 10, channel->con_handle); 3421 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 3422 little_endian_store_16(event, 13, channel->psm); 3423 little_endian_store_16(event, 15, channel->local_cid); 3424 little_endian_store_16(event, 17, channel->remote_cid); 3425 little_endian_store_16(event, 19, channel->local_mtu); 3426 little_endian_store_16(event, 21, channel->remote_mtu); 3427 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 3428 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 3429 } 3430 3431 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 3432 btstack_linked_list_iterator_t it; 3433 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 3434 while (btstack_linked_list_iterator_has_next(&it)){ 3435 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 3436 if ( channel->local_cid == local_cid) { 3437 return channel; 3438 } 3439 } 3440 return NULL; 3441 } 3442 3443 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 3444 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 3445 channel->state = L2CAP_STATE_CLOSED; 3446 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 3447 // discard channel 3448 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 3449 btstack_memory_l2cap_channel_free(channel); 3450 } 3451 3452 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 3453 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 3454 } 3455 3456 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 3457 3458 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 3459 3460 // check for alread registered psm 3461 l2cap_service_t *service = l2cap_le_get_service(psm); 3462 if (service) { 3463 return L2CAP_SERVICE_ALREADY_REGISTERED; 3464 } 3465 3466 // alloc structure 3467 service = btstack_memory_l2cap_service_get(); 3468 if (!service) { 3469 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 3470 return BTSTACK_MEMORY_ALLOC_FAILED; 3471 } 3472 3473 // fill in 3474 service->psm = psm; 3475 service->mtu = 0; 3476 service->packet_handler = packet_handler; 3477 service->required_security_level = security_level; 3478 3479 // add to services list 3480 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 3481 3482 // done 3483 return 0; 3484 } 3485 3486 uint8_t l2cap_le_unregister_service(uint16_t psm) { 3487 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 3488 l2cap_service_t *service = l2cap_le_get_service(psm); 3489 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 3490 3491 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 3492 btstack_memory_l2cap_service_free(service); 3493 return 0; 3494 } 3495 3496 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 3497 // get channel 3498 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3499 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3500 3501 // validate state 3502 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 3503 return ERROR_CODE_COMMAND_DISALLOWED; 3504 } 3505 3506 // set state accept connection 3507 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 3508 channel->receive_sdu_buffer = receive_sdu_buffer; 3509 channel->local_mtu = mtu; 3510 channel->new_credits_incoming = initial_credits; 3511 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 3512 3513 // test 3514 // channel->new_credits_incoming = 1; 3515 3516 // go 3517 l2cap_run(); 3518 return 0; 3519 } 3520 3521 /** 3522 * @brief Deny incoming LE Data Channel connection due to resource constraints 3523 * @param local_cid L2CAP LE Data Channel Identifier 3524 */ 3525 3526 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 3527 // get channel 3528 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3529 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3530 3531 // validate state 3532 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 3533 return ERROR_CODE_COMMAND_DISALLOWED; 3534 } 3535 3536 // set state decline connection 3537 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 3538 channel->reason = 0x04; // no resources available 3539 l2cap_run(); 3540 return 0; 3541 } 3542 3543 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 3544 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 3545 uint16_t * out_local_cid) { 3546 3547 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 3548 3549 3550 hci_connection_t * connection = hci_connection_for_handle(con_handle); 3551 if (!connection) { 3552 log_error("no hci_connection for handle 0x%04x", con_handle); 3553 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 3554 } 3555 3556 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 3557 if (!channel) { 3558 return BTSTACK_MEMORY_ALLOC_FAILED; 3559 } 3560 log_info("l2cap_le_create_channel %p", channel); 3561 3562 // store local_cid 3563 if (out_local_cid){ 3564 *out_local_cid = channel->local_cid; 3565 } 3566 3567 // provide buffer 3568 channel->con_handle = con_handle; 3569 channel->receive_sdu_buffer = receive_sdu_buffer; 3570 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 3571 channel->new_credits_incoming = initial_credits; 3572 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 3573 3574 // add to connections list 3575 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 3576 3577 // go 3578 l2cap_run(); 3579 return 0; 3580 } 3581 3582 /** 3583 * @brief Provide credtis for LE Data Channel 3584 * @param local_cid L2CAP LE Data Channel Identifier 3585 * @param credits Number additional credits for peer 3586 */ 3587 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 3588 3589 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3590 if (!channel) { 3591 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 3592 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3593 } 3594 3595 // check state 3596 if (channel->state != L2CAP_STATE_OPEN){ 3597 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 3598 } 3599 3600 // assert incoming credits + credits <= 0xffff 3601 uint32_t total_credits = channel->credits_incoming; 3602 total_credits += channel->new_credits_incoming; 3603 total_credits += credits; 3604 if (total_credits > 0xffff){ 3605 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 3606 channel->new_credits_incoming, credits); 3607 } 3608 3609 // set credits_granted 3610 channel->new_credits_incoming += credits; 3611 3612 // go 3613 l2cap_run(); 3614 return 0; 3615 } 3616 3617 /** 3618 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 3619 * @param local_cid L2CAP LE Data Channel Identifier 3620 */ 3621 int l2cap_le_can_send_now(uint16_t local_cid){ 3622 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3623 if (!channel) { 3624 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 3625 return 0; 3626 } 3627 3628 // check state 3629 if (channel->state != L2CAP_STATE_OPEN) return 0; 3630 3631 // check queue 3632 if (channel->send_sdu_buffer) return 0; 3633 3634 // fine, go ahead 3635 return 1; 3636 } 3637 3638 /** 3639 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 3640 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 3641 * so packet handler should be ready to handle it 3642 * @param local_cid L2CAP LE Data Channel Identifier 3643 */ 3644 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 3645 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3646 if (!channel) { 3647 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 3648 return 0; 3649 } 3650 channel->waiting_for_can_send_now = 1; 3651 l2cap_le_notify_channel_can_send(channel); 3652 return 0; 3653 } 3654 3655 /** 3656 * @brief Send data via LE Data Channel 3657 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 3658 * @param local_cid L2CAP LE Data Channel Identifier 3659 * @param data data to send 3660 * @param size data size 3661 */ 3662 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 3663 3664 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3665 if (!channel) { 3666 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 3667 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3668 } 3669 3670 if (len > channel->remote_mtu){ 3671 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 3672 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 3673 } 3674 3675 if (channel->send_sdu_buffer){ 3676 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 3677 return BTSTACK_ACL_BUFFERS_FULL; 3678 } 3679 3680 channel->send_sdu_buffer = data; 3681 channel->send_sdu_len = len; 3682 channel->send_sdu_pos = 0; 3683 3684 l2cap_run(); 3685 return 0; 3686 } 3687 3688 /** 3689 * @brief Disconnect from LE Data Channel 3690 * @param local_cid L2CAP LE Data Channel Identifier 3691 */ 3692 uint8_t l2cap_le_disconnect(uint16_t local_cid) 3693 { 3694 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 3695 if (!channel) { 3696 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 3697 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 3698 } 3699 3700 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 3701 l2cap_run(); 3702 return 0; 3703 } 3704 3705 #endif 3706