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 /* 39 * l2cap.c 40 * 41 * Logical Link Control and Adaption Protocl (L2CAP) 42 * 43 * Created by Matthias Ringwald on 5/16/09. 44 */ 45 46 #include "l2cap.h" 47 #include "hci.h" 48 #include "hci_dump.h" 49 #include "btstack_debug.h" 50 #include "btstack_event.h" 51 #include "btstack_memory.h" 52 53 #ifdef ENABLE_LE_DATA_CHANNELS 54 #include "ble/sm.h" 55 #endif 56 57 #include <stdarg.h> 58 #include <string.h> 59 60 #include <stdio.h> 61 62 // nr of buffered acl packets in outgoing queue to get max performance 63 #define NR_BUFFERED_ACL_PACKETS 3 64 65 // used to cache l2cap rejects, echo, and informational requests 66 #define NR_PENDING_SIGNALING_RESPONSES 3 67 68 // nr of credits provided to remote if credits fall below watermark 69 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK 5 70 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT 5 71 72 // offsets for L2CAP SIGNALING COMMANDS 73 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 74 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 75 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 76 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 77 78 // internal table 79 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL 0 80 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL 1 81 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL 2 82 #define L2CAP_FIXED_CHANNEL_TABLE_SIZE (L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL+1) 83 84 #if defined(ENABLE_LE_DATA_CHANNELS) || defined(ENABLE_CLASSIC) 85 #define L2CAP_USES_CHANNELS 86 #endif 87 88 // prototypes 89 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 90 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ); 91 static void l2cap_notify_channel_can_send(void); 92 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel); 93 #ifdef ENABLE_CLASSIC 94 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 95 static inline l2cap_service_t * l2cap_get_service(uint16_t psm); 96 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 97 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 98 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel); 99 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 100 #endif 101 #ifdef ENABLE_LE_DATA_CHANNELS 102 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status); 103 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel); 104 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid); 105 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel); 106 static void l2cap_le_finialize_channel_close(l2cap_channel_t *channel); 107 static inline l2cap_service_t * l2cap_le_get_service(uint16_t psm); 108 #endif 109 110 typedef struct l2cap_fixed_channel { 111 btstack_packet_handler_t callback; 112 uint8_t waiting_for_can_send_now; 113 } l2cap_fixed_channel_t; 114 115 #ifdef ENABLE_CLASSIC 116 static btstack_linked_list_t l2cap_channels; 117 static btstack_linked_list_t l2cap_services; 118 static uint8_t require_security_level2_for_outgoing_sdp; 119 #endif 120 121 #ifdef ENABLE_LE_DATA_CHANNELS 122 static btstack_linked_list_t l2cap_le_channels; 123 static btstack_linked_list_t l2cap_le_services; 124 #endif 125 126 // used to cache l2cap rejects, echo, and informational requests 127 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 128 static int signaling_responses_pending; 129 130 static btstack_packet_callback_registration_t hci_event_callback_registration; 131 132 static btstack_packet_handler_t l2cap_event_packet_handler; 133 static l2cap_fixed_channel_t fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_SIZE]; 134 135 static uint16_t l2cap_fixed_channel_table_channel_id_for_index(int index){ 136 switch (index){ 137 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL: 138 return L2CAP_CID_ATTRIBUTE_PROTOCOL; 139 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL: 140 return L2CAP_CID_SECURITY_MANAGER_PROTOCOL; 141 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL: 142 return L2CAP_CID_CONNECTIONLESS_CHANNEL; 143 default: 144 return 0; 145 } 146 } 147 static int l2cap_fixed_channel_table_index_for_channel_id(uint16_t channel_id){ 148 switch (channel_id){ 149 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 150 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL; 151 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 152 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL; 153 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 154 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL; 155 default: 156 return -1; 157 } 158 } 159 160 static int l2cap_fixed_channel_table_index_is_le(int index){ 161 if (index == L2CAP_CID_CONNECTIONLESS_CHANNEL) return 0; 162 return 1; 163 } 164 165 void l2cap_init(void){ 166 signaling_responses_pending = 0; 167 168 #ifdef ENABLE_CLASSIC 169 l2cap_channels = NULL; 170 l2cap_services = NULL; 171 require_security_level2_for_outgoing_sdp = 0; 172 #endif 173 174 #ifdef ENABLE_LE_DATA_CHANNELS 175 l2cap_le_services = NULL; 176 l2cap_le_channels = NULL; 177 #endif 178 179 l2cap_event_packet_handler = NULL; 180 memset(fixed_channels, 0, sizeof(fixed_channels)); 181 182 // 183 // register callback with HCI 184 // 185 hci_event_callback_registration.callback = &l2cap_hci_event_handler; 186 hci_add_event_handler(&hci_event_callback_registration); 187 188 hci_register_acl_packet_handler(&l2cap_acl_handler); 189 190 gap_connectable_control(0); // no services yet 191 } 192 193 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 194 l2cap_event_packet_handler = handler; 195 } 196 197 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ 198 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 199 if (index < 0) return; 200 fixed_channels[index].waiting_for_can_send_now = 1; 201 l2cap_notify_channel_can_send(); 202 } 203 204 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ 205 return hci_can_send_acl_packet_now(con_handle); 206 } 207 208 uint8_t *l2cap_get_outgoing_buffer(void){ 209 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 210 } 211 212 int l2cap_reserve_packet_buffer(void){ 213 return hci_reserve_packet_buffer(); 214 } 215 216 void l2cap_release_packet_buffer(void){ 217 hci_release_packet_buffer(); 218 } 219 220 static void l2cap_setup_header(uint8_t * acl_buffer, hci_con_handle_t con_handle, uint16_t remote_cid, uint16_t len){ 221 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 222 223 // 0 - Connection handle : PB=pb : BC=00 224 little_endian_store_16(acl_buffer, 0, con_handle | (pb << 12) | (0 << 14)); 225 // 2 - ACL length 226 little_endian_store_16(acl_buffer, 2, len + 4); 227 // 4 - L2CAP packet length 228 little_endian_store_16(acl_buffer, 4, len + 0); 229 // 6 - L2CAP channel DEST 230 little_endian_store_16(acl_buffer, 6, remote_cid); 231 } 232 233 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 234 235 if (!hci_is_packet_buffer_reserved()){ 236 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 237 return BTSTACK_ACL_BUFFERS_FULL; 238 } 239 240 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 241 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 242 return BTSTACK_ACL_BUFFERS_FULL; 243 } 244 245 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 246 247 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 248 l2cap_setup_header(acl_buffer, con_handle, cid, len); 249 // send 250 return hci_send_acl_packet_buffer(len+8); 251 } 252 253 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 254 255 if (!hci_can_send_acl_packet_now(con_handle)){ 256 log_info("l2cap_send cid 0x%02x, cannot send", cid); 257 return BTSTACK_ACL_BUFFERS_FULL; 258 } 259 260 hci_reserve_packet_buffer(); 261 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 262 263 memcpy(&acl_buffer[8], data, len); 264 265 return l2cap_send_prepared_connectionless(con_handle, cid, len); 266 } 267 268 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { 269 log_info("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); 270 uint8_t event[4]; 271 event[0] = L2CAP_EVENT_CAN_SEND_NOW; 272 event[1] = sizeof(event) - 2; 273 little_endian_store_16(event, 2, channel); 274 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 275 packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); 276 } 277 278 #ifdef L2CAP_USES_CHANNELS 279 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 280 (* (channel->packet_handler))(type, channel->local_cid, data, size); 281 } 282 283 static void l2cap_emit_simple_event_with_cid(l2cap_channel_t * channel, uint8_t event_code){ 284 uint8_t event[4]; 285 event[0] = event_code; 286 event[1] = sizeof(event) - 2; 287 little_endian_store_16(event, 2, channel->local_cid); 288 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 289 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 290 } 291 #endif 292 293 #ifdef ENABLE_CLASSIC 294 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 295 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", 296 status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 297 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 298 uint8_t event[23]; 299 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 300 event[1] = sizeof(event) - 2; 301 event[2] = status; 302 reverse_bd_addr(channel->address, &event[3]); 303 little_endian_store_16(event, 9, channel->con_handle); 304 little_endian_store_16(event, 11, channel->psm); 305 little_endian_store_16(event, 13, channel->local_cid); 306 little_endian_store_16(event, 15, channel->remote_cid); 307 little_endian_store_16(event, 17, channel->local_mtu); 308 little_endian_store_16(event, 19, channel->remote_mtu); 309 little_endian_store_16(event, 21, channel->flush_timeout); 310 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 311 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 312 } 313 314 static void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 315 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 316 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 317 } 318 319 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel) { 320 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 321 bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); 322 uint8_t event[16]; 323 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 324 event[1] = sizeof(event) - 2; 325 reverse_bd_addr(channel->address, &event[2]); 326 little_endian_store_16(event, 8, channel->con_handle); 327 little_endian_store_16(event, 10, channel->psm); 328 little_endian_store_16(event, 12, channel->local_cid); 329 little_endian_store_16(event, 14, channel->remote_cid); 330 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 331 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 332 } 333 334 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 335 btstack_linked_list_iterator_t it; 336 btstack_linked_list_iterator_init(&it, &l2cap_channels); 337 while (btstack_linked_list_iterator_has_next(&it)){ 338 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 339 if ( channel->local_cid == local_cid) { 340 return channel; 341 } 342 } 343 return NULL; 344 } 345 346 /// 347 348 void l2cap_request_can_send_now_event(uint16_t local_cid){ 349 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 350 if (!channel) return; 351 channel->waiting_for_can_send_now = 1; 352 l2cap_notify_channel_can_send(); 353 } 354 355 int l2cap_can_send_packet_now(uint16_t local_cid){ 356 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 357 if (!channel) return 0; 358 return hci_can_send_acl_packet_now(channel->con_handle); 359 } 360 361 int l2cap_can_send_prepared_packet_now(uint16_t local_cid){ 362 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 363 if (!channel) return 0; 364 return hci_can_send_prepared_acl_packet_now(channel->con_handle); 365 } 366 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 367 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 368 if (channel) { 369 return channel->remote_mtu; 370 } 371 return 0; 372 } 373 374 static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ 375 btstack_linked_list_iterator_t it; 376 btstack_linked_list_iterator_init(&it, &l2cap_channels); 377 while (btstack_linked_list_iterator_has_next(&it)){ 378 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 379 if ( &channel->rtx == ts) { 380 return channel; 381 } 382 } 383 return NULL; 384 } 385 386 static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ 387 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 388 if (!channel) return; 389 390 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 391 392 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 393 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 394 // notify client 395 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 396 397 // discard channel 398 // no need to stop timer here, it is removed from list during timer callback 399 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 400 btstack_memory_l2cap_channel_free(channel); 401 } 402 403 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 404 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 405 btstack_run_loop_remove_timer(&channel->rtx); 406 } 407 408 static void l2cap_start_rtx(l2cap_channel_t * channel){ 409 l2cap_stop_rtx(channel); 410 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 411 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 412 btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 413 btstack_run_loop_add_timer(&channel->rtx); 414 } 415 416 static void l2cap_start_ertx(l2cap_channel_t * channel){ 417 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 418 l2cap_stop_rtx(channel); 419 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 420 btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 421 btstack_run_loop_add_timer(&channel->rtx); 422 } 423 424 void l2cap_require_security_level_2_for_outgoing_sdp(void){ 425 require_security_level2_for_outgoing_sdp = 1; 426 } 427 428 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 429 return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); 430 } 431 432 static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 433 if (!hci_can_send_acl_packet_now(handle)){ 434 log_info("l2cap_send_signaling_packet, cannot send"); 435 return BTSTACK_ACL_BUFFERS_FULL; 436 } 437 438 // log_info("l2cap_send_signaling_packet type %u", cmd); 439 hci_reserve_packet_buffer(); 440 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 441 va_list argptr; 442 va_start(argptr, identifier); 443 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 444 va_end(argptr); 445 // log_info("l2cap_send_signaling_packet con %u!", handle); 446 return hci_send_acl_packet_buffer(len); 447 } 448 449 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 450 451 if (!hci_is_packet_buffer_reserved()){ 452 log_error("l2cap_send_prepared called without reserving packet first"); 453 return BTSTACK_ACL_BUFFERS_FULL; 454 } 455 456 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 457 if (!channel) { 458 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 459 return -1; // TODO: define error 460 } 461 462 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 463 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 464 return BTSTACK_ACL_BUFFERS_FULL; 465 } 466 467 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 468 469 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 470 l2cap_setup_header(acl_buffer, channel->con_handle, channel->remote_cid, len); 471 // send 472 return hci_send_acl_packet_buffer(len+8); 473 } 474 475 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 476 477 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 478 if (!channel) { 479 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 480 return -1; // TODO: define error 481 } 482 483 if (len > channel->remote_mtu){ 484 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 485 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 486 } 487 488 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 489 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 490 return BTSTACK_ACL_BUFFERS_FULL; 491 } 492 493 hci_reserve_packet_buffer(); 494 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 495 496 memcpy(&acl_buffer[8], data, len); 497 498 return l2cap_send_prepared(local_cid, len); 499 } 500 501 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ 502 return l2cap_send_signaling_packet(con_handle, ECHO_REQUEST, 0x77, len, data); 503 } 504 505 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 506 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 507 } 508 509 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 510 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 511 } 512 #endif 513 514 515 #ifdef ENABLE_BLE 516 static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 517 518 if (!hci_can_send_acl_packet_now(handle)){ 519 log_info("l2cap_send_le_signaling_packet, cannot send"); 520 return BTSTACK_ACL_BUFFERS_FULL; 521 } 522 523 // log_info("l2cap_send_le_signaling_packet type %u", cmd); 524 hci_reserve_packet_buffer(); 525 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 526 va_list argptr; 527 va_start(argptr, identifier); 528 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 529 va_end(argptr); 530 // log_info("l2cap_send_le_signaling_packet con %u!", handle); 531 return hci_send_acl_packet_buffer(len); 532 } 533 #endif 534 535 uint16_t l2cap_max_mtu(void){ 536 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 537 } 538 539 uint16_t l2cap_max_le_mtu(void){ 540 return l2cap_max_mtu(); 541 } 542 543 // MARK: L2CAP_RUN 544 // process outstanding signaling tasks 545 static void l2cap_run(void){ 546 547 // log_info("l2cap_run: entered"); 548 549 // check pending signaling responses 550 while (signaling_responses_pending){ 551 552 hci_con_handle_t handle = signaling_responses[0].handle; 553 554 if (!hci_can_send_acl_packet_now(handle)) break; 555 556 uint8_t sig_id = signaling_responses[0].sig_id; 557 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 558 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 559 uint8_t response_code = signaling_responses[0].code; 560 561 // avoid warnings 562 (void) infoType; 563 564 // remove first item before sending (to avoid sending response mutliple times) 565 signaling_responses_pending--; 566 int i; 567 for (i=0; i < signaling_responses_pending; i++){ 568 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 569 } 570 571 switch (response_code){ 572 #ifdef ENABLE_CLASSIC 573 case CONNECTION_REQUEST: 574 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 575 // also disconnect if result is 0x0003 - security blocked 576 if (result == 0x0003){ 577 hci_disconnect_security_block(handle); 578 } 579 break; 580 case ECHO_REQUEST: 581 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 582 break; 583 case INFORMATION_REQUEST: 584 switch (infoType){ 585 case 1: { // Connectionless MTU 586 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 587 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 588 } 589 break; 590 case 2: { // Extended Features Supported 591 // extended features request supported, features: fixed channels, unicast connectionless data reception 592 uint32_t features = 0x280; 593 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 594 } 595 break; 596 case 3: { // Fixed Channels Supported 597 uint8_t map[8]; 598 memset(map, 0, 8); 599 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 600 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 601 } 602 break; 603 default: 604 // all other types are not supported 605 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 606 break; 607 } 608 break; 609 case COMMAND_REJECT: 610 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 611 break; 612 #endif 613 #ifdef ENABLE_BLE 614 case LE_CREDIT_BASED_CONNECTION_REQUEST: 615 l2cap_send_le_signaling_packet(handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, sig_id, 0, 0, 0, 0, result); 616 break; 617 case COMMAND_REJECT_LE: 618 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 619 break; 620 #endif 621 default: 622 // should not happen 623 break; 624 } 625 } 626 627 btstack_linked_list_iterator_t it; 628 (void) it; 629 630 #ifdef ENABLE_CLASSIC 631 uint8_t config_options[4]; 632 btstack_linked_list_iterator_init(&it, &l2cap_channels); 633 while (btstack_linked_list_iterator_has_next(&it)){ 634 635 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 636 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 637 switch (channel->state){ 638 639 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 640 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 641 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 642 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 643 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 644 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 645 } 646 break; 647 648 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 649 if (!hci_can_send_command_packet_now()) break; 650 // send connection request - set state first 651 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 652 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 653 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 654 break; 655 656 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 657 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 658 channel->state = L2CAP_STATE_INVALID; 659 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 660 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 661 l2cap_stop_rtx(channel); 662 btstack_linked_list_iterator_remove(&it); 663 btstack_memory_l2cap_channel_free(channel); 664 break; 665 666 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 667 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 668 channel->state = L2CAP_STATE_CONFIG; 669 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 670 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 671 break; 672 673 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 674 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 675 // success, start l2cap handshake 676 channel->local_sig_id = l2cap_next_sig_id(); 677 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 678 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 679 l2cap_start_rtx(channel); 680 break; 681 682 case L2CAP_STATE_CONFIG: 683 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 684 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 685 uint16_t flags = 0; 686 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 687 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 688 flags = 1; 689 } else { 690 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 691 } 692 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 693 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 694 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 695 config_options[0] = 1; // MTU 696 config_options[1] = 2; // len param 697 little_endian_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 698 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 699 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 700 } else { 701 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 702 } 703 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 704 } 705 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 706 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 707 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 708 channel->local_sig_id = l2cap_next_sig_id(); 709 config_options[0] = 1; // MTU 710 config_options[1] = 2; // len param 711 little_endian_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 712 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 713 l2cap_start_rtx(channel); 714 } 715 if (l2cap_channel_ready_for_open(channel)){ 716 channel->state = L2CAP_STATE_OPEN; 717 l2cap_emit_channel_opened(channel, 0); // success 718 } 719 break; 720 721 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 722 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 723 channel->state = L2CAP_STATE_INVALID; 724 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 725 // 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 :) 726 l2cap_finialize_channel_close(channel); // -- remove from list 727 break; 728 729 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 730 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 731 channel->local_sig_id = l2cap_next_sig_id(); 732 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 733 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 734 break; 735 default: 736 break; 737 } 738 } 739 #endif 740 741 #ifdef ENABLE_LE_DATA_CHANNELS 742 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 743 while (btstack_linked_list_iterator_has_next(&it)){ 744 uint8_t * acl_buffer; 745 uint8_t * l2cap_payload; 746 uint16_t pos; 747 uint16_t payload_size; 748 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 749 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 750 switch (channel->state){ 751 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 752 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 753 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 754 // le psm, source cid, mtu, mps, initial credits 755 channel->local_sig_id = l2cap_next_sig_id(); 756 channel->credits_incoming = channel->new_credits_incoming; 757 channel->new_credits_incoming = 0; 758 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); 759 break; 760 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 761 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 762 // TODO: support larger MPS 763 channel->state = L2CAP_STATE_OPEN; 764 channel->credits_incoming = channel->new_credits_incoming; 765 channel->new_credits_incoming = 0; 766 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); 767 // notify client 768 l2cap_emit_le_channel_opened(channel, 0); 769 break; 770 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 771 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 772 channel->state = L2CAP_STATE_INVALID; 773 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); 774 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 775 l2cap_stop_rtx(channel); 776 btstack_linked_list_iterator_remove(&it); 777 btstack_memory_l2cap_channel_free(channel); 778 break; 779 case L2CAP_STATE_OPEN: 780 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 781 782 // send credits 783 if (channel->new_credits_incoming){ 784 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 785 channel->local_sig_id = l2cap_next_sig_id(); 786 uint16_t new_credits = channel->new_credits_incoming; 787 channel->new_credits_incoming = 0; 788 channel->credits_incoming += new_credits; 789 l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); 790 break; 791 } 792 793 // send data 794 if (!channel->send_sdu_buffer) break; 795 if (!channel->credits_outgoing) break; 796 797 // send part of SDU 798 hci_reserve_packet_buffer(); 799 acl_buffer = hci_get_outgoing_packet_buffer(); 800 l2cap_payload = acl_buffer + 8; 801 pos = 0; 802 if (!channel->send_sdu_pos){ 803 // store SDU len 804 channel->send_sdu_pos += 2; 805 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 806 pos += 2; 807 } 808 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 809 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); 810 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 811 pos += payload_size; 812 channel->send_sdu_pos += payload_size; 813 l2cap_setup_header(acl_buffer, channel->con_handle, channel->remote_cid, pos); 814 // done 815 816 channel->credits_outgoing--; 817 818 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 819 channel->send_sdu_buffer = NULL; 820 // send done event 821 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_PACKET_SENT); 822 // inform about can send now 823 l2cap_le_notify_channel_can_send(channel); 824 } 825 hci_send_acl_packet_buffer(8 + pos); 826 break; 827 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 828 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 829 channel->local_sig_id = l2cap_next_sig_id(); 830 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 831 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 832 break; 833 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 834 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 835 channel->state = L2CAP_STATE_INVALID; 836 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 837 l2cap_le_finialize_channel_close(channel); // -- remove from list 838 break; 839 default: 840 break; 841 } 842 } 843 #endif 844 845 #ifdef ENABLE_BLE 846 // send l2cap con paramter update if necessary 847 hci_connections_get_iterator(&it); 848 while(btstack_linked_list_iterator_has_next(&it)){ 849 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 850 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 851 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 852 switch (connection->le_con_parameter_update_state){ 853 case CON_PARAMETER_UPDATE_SEND_REQUEST: 854 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 855 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 856 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 857 break; 858 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 859 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 860 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 861 break; 862 case CON_PARAMETER_UPDATE_DENY: 863 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 864 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 865 break; 866 default: 867 break; 868 } 869 } 870 #endif 871 872 // log_info("l2cap_run: exit"); 873 } 874 875 #ifdef ENABLE_CLASSIC 876 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 877 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 878 log_info("l2cap_handle_connection_complete expected state"); 879 // success, start l2cap handshake 880 channel->con_handle = con_handle; 881 // check remote SSP feature first 882 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 883 } 884 } 885 886 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 887 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 888 889 // we have been waiting for remote supported features, if both support SSP, 890 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)); 891 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 892 // request security level 2 893 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 894 gap_request_security_level(channel->con_handle, LEVEL_2); 895 return; 896 } 897 // fine, go ahead 898 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 899 } 900 #endif 901 902 #ifdef L2CAP_USES_CHANNELS 903 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 904 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 905 906 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 907 if (!channel) { 908 return NULL; 909 } 910 911 // Init memory (make valgrind happy) 912 memset(channel, 0, sizeof(l2cap_channel_t)); 913 914 // fill in 915 channel->packet_handler = packet_handler; 916 bd_addr_copy(channel->address, address); 917 channel->address_type = address_type; 918 channel->psm = psm; 919 channel->local_mtu = local_mtu; 920 channel->remote_mtu = L2CAP_MINIMAL_MTU; 921 channel->required_security_level = security_level; 922 923 // 924 channel->local_cid = l2cap_next_local_cid(); 925 channel->con_handle = 0; 926 927 // set initial state 928 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 929 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 930 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 931 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 932 return channel; 933 } 934 #endif 935 936 #ifdef ENABLE_CLASSIC 937 938 /** 939 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 940 * @param packet_handler 941 * @param address 942 * @param psm 943 * @param mtu 944 * @param local_cid 945 */ 946 947 uint8_t l2cap_create_channel(btstack_packet_handler_t channel_packet_handler, bd_addr_t address, uint16_t psm, uint16_t local_mtu, uint16_t * out_local_cid){ 948 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, local_mtu); 949 950 if (local_mtu > l2cap_max_mtu()) { 951 local_mtu = l2cap_max_mtu(); 952 } 953 954 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 955 if (!channel) { 956 return BTSTACK_MEMORY_ALLOC_FAILED; 957 } 958 959 // add to connections list 960 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 961 962 // store local_cid 963 if (out_local_cid){ 964 *out_local_cid = channel->local_cid; 965 } 966 967 // check if hci connection is already usable 968 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 969 if (conn){ 970 log_info("l2cap_create_channel, hci connection already exists"); 971 l2cap_handle_connection_complete(conn->con_handle, channel); 972 // check if remote supported fearures are already received 973 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 974 l2cap_handle_remote_supported_features_received(channel); 975 } 976 } 977 978 l2cap_run(); 979 980 return 0; 981 } 982 983 void 984 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 985 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 986 // find channel for local_cid 987 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 988 if (channel) { 989 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 990 } 991 // process 992 l2cap_run(); 993 } 994 995 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 996 btstack_linked_list_iterator_t it; 997 btstack_linked_list_iterator_init(&it, &l2cap_channels); 998 while (btstack_linked_list_iterator_has_next(&it)){ 999 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1000 if ( bd_addr_cmp( channel->address, address) != 0) continue; 1001 // channel for this address found 1002 switch (channel->state){ 1003 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1004 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1005 // failure, forward error code 1006 l2cap_emit_channel_opened(channel, status); 1007 // discard channel 1008 l2cap_stop_rtx(channel); 1009 btstack_linked_list_iterator_remove(&it); 1010 btstack_memory_l2cap_channel_free(channel); 1011 break; 1012 default: 1013 break; 1014 } 1015 } 1016 } 1017 1018 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1019 btstack_linked_list_iterator_t it; 1020 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1021 while (btstack_linked_list_iterator_has_next(&it)){ 1022 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1023 if ( ! bd_addr_cmp( channel->address, address) ){ 1024 l2cap_handle_connection_complete(handle, channel); 1025 } 1026 } 1027 // process 1028 l2cap_run(); 1029 } 1030 #endif 1031 1032 static void l2cap_notify_channel_can_send(void){ 1033 1034 #ifdef ENABLE_CLASSIC 1035 btstack_linked_list_iterator_t it; 1036 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1037 while (btstack_linked_list_iterator_has_next(&it)){ 1038 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1039 if (!channel->waiting_for_can_send_now) continue; 1040 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1041 channel->waiting_for_can_send_now = 0; 1042 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1043 } 1044 #endif 1045 1046 int i; 1047 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1048 if (!fixed_channels[i].callback) continue; 1049 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1050 int can_send; 1051 if (l2cap_fixed_channel_table_index_is_le(i)){ 1052 can_send = hci_can_send_acl_le_packet_now(); 1053 } else { 1054 can_send = hci_can_send_acl_classic_packet_now(); 1055 } 1056 if (!can_send) continue; 1057 fixed_channels[i].waiting_for_can_send_now = 0; 1058 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1059 } 1060 } 1061 1062 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1063 1064 bd_addr_t address; 1065 hci_con_handle_t handle; 1066 int hci_con_used; 1067 btstack_linked_list_iterator_t it; 1068 1069 // avoid unused warnings 1070 (void) address; 1071 (void) hci_con_used; 1072 (void) it; 1073 1074 switch(hci_event_packet_get_type(packet)){ 1075 1076 // Notify channel packet handler if they can send now 1077 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1078 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1079 l2cap_run(); // try sending signaling packets first 1080 l2cap_notify_channel_can_send(); 1081 break; 1082 1083 case HCI_EVENT_COMMAND_STATUS: 1084 l2cap_run(); // try sending signaling packets first 1085 break; 1086 1087 #ifdef ENABLE_CLASSIC 1088 // handle connection complete events 1089 case HCI_EVENT_CONNECTION_COMPLETE: 1090 reverse_bd_addr(&packet[5], address); 1091 if (packet[2] == 0){ 1092 handle = little_endian_read_16(packet, 3); 1093 l2cap_handle_connection_success_for_addr(address, handle); 1094 } else { 1095 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1096 } 1097 break; 1098 1099 // handle successful create connection cancel command 1100 case HCI_EVENT_COMMAND_COMPLETE: 1101 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1102 if (packet[5] == 0){ 1103 reverse_bd_addr(&packet[6], address); 1104 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1105 l2cap_handle_connection_failed_for_addr(address, 0x16); 1106 } 1107 } 1108 l2cap_run(); // try sending signaling packets first 1109 break; 1110 #endif 1111 1112 // handle disconnection complete events 1113 case HCI_EVENT_DISCONNECTION_COMPLETE: 1114 // send l2cap disconnect events for all channels on this handle and free them 1115 handle = little_endian_read_16(packet, 3); 1116 #ifdef ENABLE_CLASSIC 1117 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1118 while (btstack_linked_list_iterator_has_next(&it)){ 1119 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1120 if (channel->con_handle != handle) continue; 1121 l2cap_emit_channel_closed(channel); 1122 l2cap_stop_rtx(channel); 1123 btstack_linked_list_iterator_remove(&it); 1124 btstack_memory_l2cap_channel_free(channel); 1125 } 1126 #endif 1127 #ifdef ENABLE_LE_DATA_CHANNELS 1128 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1129 while (btstack_linked_list_iterator_has_next(&it)){ 1130 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1131 if (channel->con_handle != handle) continue; 1132 l2cap_emit_channel_closed(channel); 1133 btstack_linked_list_iterator_remove(&it); 1134 btstack_memory_l2cap_channel_free(channel); 1135 } 1136 #endif 1137 break; 1138 1139 // HCI Connection Timeouts 1140 #ifdef ENABLE_CLASSIC 1141 case L2CAP_EVENT_TIMEOUT_CHECK: 1142 handle = little_endian_read_16(packet, 2); 1143 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1144 if (hci_authentication_active_for_handle(handle)) break; 1145 hci_con_used = 0; 1146 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1147 while (btstack_linked_list_iterator_has_next(&it)){ 1148 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1149 if (channel->con_handle != handle) continue; 1150 hci_con_used = 1; 1151 break; 1152 } 1153 if (hci_con_used) break; 1154 if (!hci_can_send_command_packet_now()) break; 1155 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1156 break; 1157 1158 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1159 handle = little_endian_read_16(packet, 3); 1160 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1161 while (btstack_linked_list_iterator_has_next(&it)){ 1162 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1163 if (channel->con_handle != handle) continue; 1164 l2cap_handle_remote_supported_features_received(channel); 1165 break; 1166 } 1167 break; 1168 1169 case GAP_EVENT_SECURITY_LEVEL: 1170 handle = little_endian_read_16(packet, 2); 1171 log_info("l2cap - security level update"); 1172 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1173 while (btstack_linked_list_iterator_has_next(&it)){ 1174 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1175 if (channel->con_handle != handle) continue; 1176 1177 log_info("l2cap - state %u", channel->state); 1178 1179 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1180 gap_security_level_t required_level = channel->required_security_level; 1181 1182 switch (channel->state){ 1183 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1184 if (actual_level >= required_level){ 1185 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1186 l2cap_emit_incoming_connection(channel); 1187 } else { 1188 channel->reason = 0x0003; // security block 1189 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1190 } 1191 break; 1192 1193 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1194 if (actual_level >= required_level){ 1195 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1196 } else { 1197 // disconnnect, authentication not good enough 1198 hci_disconnect_security_block(handle); 1199 } 1200 break; 1201 1202 default: 1203 break; 1204 } 1205 } 1206 break; 1207 #endif 1208 1209 default: 1210 break; 1211 } 1212 1213 l2cap_run(); 1214 } 1215 1216 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 1217 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1218 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1219 signaling_responses[signaling_responses_pending].handle = handle; 1220 signaling_responses[signaling_responses_pending].code = code; 1221 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1222 signaling_responses[signaling_responses_pending].data = data; 1223 signaling_responses_pending++; 1224 l2cap_run(); 1225 } 1226 } 1227 1228 #ifdef ENABLE_CLASSIC 1229 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1230 channel->remote_sig_id = identifier; 1231 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1232 l2cap_run(); 1233 } 1234 1235 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1236 1237 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1238 l2cap_service_t *service = l2cap_get_service(psm); 1239 if (!service) { 1240 // 0x0002 PSM not supported 1241 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 1242 return; 1243 } 1244 1245 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1246 if (!hci_connection) { 1247 // 1248 log_error("no hci_connection for handle %u", handle); 1249 return; 1250 } 1251 1252 // alloc structure 1253 // log_info("l2cap_handle_connection_request register channel"); 1254 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1255 psm, service->mtu, service->required_security_level); 1256 if (!channel){ 1257 // 0x0004 No resources available 1258 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 1259 return; 1260 } 1261 1262 channel->con_handle = handle; 1263 channel->remote_cid = source_cid; 1264 channel->remote_sig_id = sig_id; 1265 1266 // limit local mtu to max acl packet length - l2cap header 1267 if (channel->local_mtu > l2cap_max_mtu()) { 1268 channel->local_mtu = l2cap_max_mtu(); 1269 } 1270 1271 // set initial state 1272 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1273 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1274 1275 // add to connections list 1276 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1277 1278 // assert security requirements 1279 gap_request_security_level(handle, channel->required_security_level); 1280 } 1281 1282 void l2cap_accept_connection(uint16_t local_cid){ 1283 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1284 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1285 if (!channel) { 1286 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1287 return; 1288 } 1289 1290 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1291 1292 // process 1293 l2cap_run(); 1294 } 1295 1296 void l2cap_decline_connection(uint16_t local_cid){ 1297 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1298 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1299 if (!channel) { 1300 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1301 return; 1302 } 1303 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1304 channel->reason = 0x04; // no resources available 1305 l2cap_run(); 1306 } 1307 1308 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1309 1310 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1311 1312 uint16_t flags = little_endian_read_16(command, 6); 1313 if (flags & 1) { 1314 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1315 } 1316 1317 // accept the other's configuration options 1318 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1319 uint16_t pos = 8; 1320 while (pos < end_pos){ 1321 uint8_t option_hint = command[pos] >> 7; 1322 uint8_t option_type = command[pos] & 0x7f; 1323 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1324 pos++; 1325 uint8_t length = command[pos++]; 1326 // MTU { type(8): 1, len(8):2, MTU(16) } 1327 if (option_type == 1 && length == 2){ 1328 channel->remote_mtu = little_endian_read_16(command, pos); 1329 // log_info("l2cap cid 0x%02x, remote mtu %u", channel->local_cid, channel->remote_mtu); 1330 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1331 } 1332 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1333 if (option_type == 2 && length == 2){ 1334 channel->flush_timeout = little_endian_read_16(command, pos); 1335 } 1336 // check for unknown options 1337 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1338 log_info("l2cap cid %u, unknown options", channel->local_cid); 1339 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1340 } 1341 pos += length; 1342 } 1343 } 1344 1345 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1346 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1347 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1348 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1349 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1350 if (channel->state == L2CAP_STATE_OPEN) return 0; 1351 return 1; 1352 } 1353 1354 1355 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1356 1357 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1358 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1359 uint16_t result = 0; 1360 1361 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1362 1363 // handle DISCONNECT REQUESTS seperately 1364 if (code == DISCONNECTION_REQUEST){ 1365 switch (channel->state){ 1366 case L2CAP_STATE_CONFIG: 1367 case L2CAP_STATE_OPEN: 1368 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1369 case L2CAP_STATE_WAIT_DISCONNECT: 1370 l2cap_handle_disconnect_request(channel, identifier); 1371 break; 1372 1373 default: 1374 // ignore in other states 1375 break; 1376 } 1377 return; 1378 } 1379 1380 // @STATEMACHINE(l2cap) 1381 switch (channel->state) { 1382 1383 case L2CAP_STATE_WAIT_CONNECT_RSP: 1384 switch (code){ 1385 case CONNECTION_RESPONSE: 1386 l2cap_stop_rtx(channel); 1387 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1388 switch (result) { 1389 case 0: 1390 // successful connection 1391 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1392 channel->state = L2CAP_STATE_CONFIG; 1393 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1394 break; 1395 case 1: 1396 // connection pending. get some coffee, but start the ERTX 1397 l2cap_start_ertx(channel); 1398 break; 1399 default: 1400 // channel closed 1401 channel->state = L2CAP_STATE_CLOSED; 1402 // map l2cap connection response result to BTstack status enumeration 1403 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1404 1405 // drop link key if security block 1406 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1407 gap_drop_link_key_for_bd_addr(channel->address); 1408 } 1409 1410 // discard channel 1411 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1412 btstack_memory_l2cap_channel_free(channel); 1413 break; 1414 } 1415 break; 1416 1417 default: 1418 //@TODO: implement other signaling packets 1419 break; 1420 } 1421 break; 1422 1423 case L2CAP_STATE_CONFIG: 1424 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1425 switch (code) { 1426 case CONFIGURE_REQUEST: 1427 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1428 l2cap_signaling_handle_configure_request(channel, command); 1429 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1430 // only done if continuation not set 1431 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1432 } 1433 break; 1434 case CONFIGURE_RESPONSE: 1435 l2cap_stop_rtx(channel); 1436 switch (result){ 1437 case 0: // success 1438 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1439 break; 1440 case 4: // pending 1441 l2cap_start_ertx(channel); 1442 break; 1443 default: 1444 // retry on negative result 1445 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1446 break; 1447 } 1448 break; 1449 default: 1450 break; 1451 } 1452 if (l2cap_channel_ready_for_open(channel)){ 1453 // for open: 1454 channel->state = L2CAP_STATE_OPEN; 1455 l2cap_emit_channel_opened(channel, 0); 1456 } 1457 break; 1458 1459 case L2CAP_STATE_WAIT_DISCONNECT: 1460 switch (code) { 1461 case DISCONNECTION_RESPONSE: 1462 l2cap_finialize_channel_close(channel); 1463 break; 1464 default: 1465 //@TODO: implement other signaling packets 1466 break; 1467 } 1468 break; 1469 1470 case L2CAP_STATE_CLOSED: 1471 // @TODO handle incoming requests 1472 break; 1473 1474 case L2CAP_STATE_OPEN: 1475 //@TODO: implement other signaling packets, e.g. re-configure 1476 break; 1477 default: 1478 break; 1479 } 1480 // log_info("new state %u", channel->state); 1481 } 1482 1483 1484 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1485 1486 // get code, signalind identifier and command len 1487 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1488 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1489 1490 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1491 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1492 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1493 return; 1494 } 1495 1496 // general commands without an assigned channel 1497 switch(code) { 1498 1499 case CONNECTION_REQUEST: { 1500 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1501 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1502 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1503 return; 1504 } 1505 1506 case ECHO_REQUEST: 1507 l2cap_register_signaling_response(handle, code, sig_id, 0); 1508 return; 1509 1510 case INFORMATION_REQUEST: { 1511 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1512 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1513 return; 1514 } 1515 1516 default: 1517 break; 1518 } 1519 1520 1521 // Get potential destination CID 1522 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1523 1524 // Find channel for this sig_id and connection handle 1525 btstack_linked_list_iterator_t it; 1526 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1527 while (btstack_linked_list_iterator_has_next(&it)){ 1528 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1529 if (channel->con_handle != handle) continue; 1530 if (code & 1) { 1531 // match odd commands (responses) by previous signaling identifier 1532 if (channel->local_sig_id == sig_id) { 1533 l2cap_signaling_handler_channel(channel, command); 1534 break; 1535 } 1536 } else { 1537 // match even commands (requests) by local channel id 1538 if (channel->local_cid == dest_cid) { 1539 l2cap_signaling_handler_channel(channel, command); 1540 break; 1541 } 1542 } 1543 } 1544 } 1545 #endif 1546 1547 #ifdef ENABLE_BLE 1548 1549 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 1550 uint8_t event[6]; 1551 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 1552 event[1] = 4; 1553 little_endian_store_16(event, 2, con_handle); 1554 little_endian_store_16(event, 4, result); 1555 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1556 if (!l2cap_event_packet_handler) return; 1557 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 1558 } 1559 1560 // @returns valid 1561 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 1562 hci_connection_t * connection; 1563 uint16_t result; 1564 uint8_t event[10]; 1565 1566 #ifdef ENABLE_LE_DATA_CHANNELS 1567 btstack_linked_list_iterator_t it; 1568 l2cap_channel_t * channel; 1569 uint16_t local_cid; 1570 uint16_t le_psm; 1571 uint16_t new_credits; 1572 uint16_t credits_before; 1573 l2cap_service_t * service; 1574 #endif 1575 1576 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1577 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 1578 1579 switch (code){ 1580 1581 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 1582 result = little_endian_read_16(command, 4); 1583 l2cap_emit_connection_parameter_update_response(handle, result); 1584 break; 1585 1586 case CONNECTION_PARAMETER_UPDATE_REQUEST: 1587 connection = hci_connection_for_handle(handle); 1588 if (connection){ 1589 if (connection->role != HCI_ROLE_MASTER){ 1590 // reject command without notifying upper layer when not in master role 1591 return 0; 1592 } 1593 int update_parameter = 1; 1594 le_connection_parameter_range_t existing_range; 1595 gap_get_connection_parameter_range(&existing_range); 1596 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 1597 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 1598 uint16_t le_conn_latency = little_endian_read_16(command,12); 1599 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 1600 1601 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1602 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1603 1604 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1605 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1606 1607 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1608 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1609 1610 if (update_parameter){ 1611 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1612 connection->le_conn_interval_min = le_conn_interval_min; 1613 connection->le_conn_interval_max = le_conn_interval_max; 1614 connection->le_conn_latency = le_conn_latency; 1615 connection->le_supervision_timeout = le_supervision_timeout; 1616 } else { 1617 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1618 } 1619 connection->le_con_param_update_identifier = sig_id; 1620 } 1621 1622 if (!l2cap_event_packet_handler) break; 1623 1624 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1625 event[1] = 8; 1626 memcpy(&event[2], &command[4], 8); 1627 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1628 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1629 break; 1630 1631 #ifdef ENABLE_LE_DATA_CHANNELS 1632 1633 case COMMAND_REJECT: 1634 // Find channel for this sig_id and connection handle 1635 channel = NULL; 1636 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1637 while (btstack_linked_list_iterator_has_next(&it)){ 1638 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1639 if (a_channel->con_handle != handle) continue; 1640 if (a_channel->local_sig_id != sig_id) continue; 1641 channel = a_channel; 1642 break; 1643 } 1644 if (!channel) break; 1645 1646 // if received while waiting for le connection response, assume legacy device 1647 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 1648 channel->state = L2CAP_STATE_CLOSED; 1649 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 1650 l2cap_emit_le_channel_opened(channel, 0x0002); 1651 1652 // discard channel 1653 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1654 btstack_memory_l2cap_channel_free(channel); 1655 break; 1656 } 1657 break; 1658 1659 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1660 1661 // get hci connection, bail if not found (must not happen) 1662 connection = hci_connection_for_handle(handle); 1663 if (!connection) return 0; 1664 1665 // check if service registered 1666 le_psm = little_endian_read_16(command, 4); 1667 service = l2cap_le_get_service(le_psm); 1668 1669 if (service){ 1670 1671 uint16_t source_cid = little_endian_read_16(command, 6); 1672 if (source_cid < 0x40){ 1673 // 0x0009 Connection refused - Invalid Source CID 1674 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0009); 1675 return 1; 1676 } 1677 1678 // go through list of channels for this ACL connection and check if we get a match 1679 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1680 while (btstack_linked_list_iterator_has_next(&it)){ 1681 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1682 if (a_channel->con_handle != handle) continue; 1683 if (a_channel->remote_cid != source_cid) continue; 1684 // 0x000a Connection refused - Source CID already allocated 1685 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x000a); 1686 return 1; 1687 } 1688 1689 // security: check encryption 1690 if (service->required_security_level >= LEVEL_2){ 1691 if (sm_encryption_key_size(handle) == 0){ 1692 // 0x0008 Connection refused - insufficient encryption 1693 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0008); 1694 return 1; 1695 } 1696 // anything less than 16 byte key size is insufficient 1697 if (sm_encryption_key_size(handle) < 16){ 1698 // 0x0007 Connection refused – insufficient encryption key size 1699 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0007); 1700 return 1; 1701 } 1702 } 1703 1704 // security: check authencation 1705 if (service->required_security_level >= LEVEL_3){ 1706 if (!sm_authenticated(handle)){ 1707 // 0x0005 Connection refused – insufficient authentication 1708 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0005); 1709 return 1; 1710 } 1711 } 1712 1713 // security: check authorization 1714 if (service->required_security_level >= LEVEL_4){ 1715 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 1716 // 0x0006 Connection refused – insufficient authorization 1717 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0006); 1718 return 1; 1719 } 1720 } 1721 1722 // allocate channel 1723 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 1724 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 1725 if (!channel){ 1726 // 0x0004 Connection refused – no resources available 1727 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0004); 1728 return 1; 1729 } 1730 1731 channel->con_handle = handle; 1732 channel->remote_cid = source_cid; 1733 channel->remote_sig_id = sig_id; 1734 channel->remote_mtu = little_endian_read_16(command, 8); 1735 channel->remote_mps = little_endian_read_16(command, 10); 1736 channel->credits_outgoing = little_endian_read_16(command, 12); 1737 1738 // set initial state 1739 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1740 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 1741 1742 // add to connections list 1743 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1744 1745 // post connection request event 1746 l2cap_emit_le_incoming_connection(channel); 1747 1748 } else { 1749 // Connection refused – LE_PSM not supported 1750 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0002); 1751 } 1752 break; 1753 1754 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 1755 // Find channel for this sig_id and connection handle 1756 channel = NULL; 1757 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1758 while (btstack_linked_list_iterator_has_next(&it)){ 1759 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1760 if (a_channel->con_handle != handle) continue; 1761 if (a_channel->local_sig_id != sig_id) continue; 1762 channel = a_channel; 1763 break; 1764 } 1765 if (!channel) break; 1766 1767 // cid + 0 1768 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 1769 if (result){ 1770 channel->state = L2CAP_STATE_CLOSED; 1771 // map l2cap connection response result to BTstack status enumeration 1772 l2cap_emit_le_channel_opened(channel, result); 1773 1774 // discard channel 1775 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1776 btstack_memory_l2cap_channel_free(channel); 1777 break; 1778 } 1779 1780 // success 1781 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1782 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1783 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 1784 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 1785 channel->state = L2CAP_STATE_OPEN; 1786 l2cap_emit_le_channel_opened(channel, result); 1787 break; 1788 1789 case LE_FLOW_CONTROL_CREDIT: 1790 // find channel 1791 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1792 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1793 if (!channel) { 1794 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1795 break; 1796 } 1797 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1798 credits_before = channel->credits_outgoing; 1799 channel->credits_outgoing += new_credits; 1800 // check for credit overrun 1801 if (credits_before > channel->credits_outgoing){ 1802 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 1803 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1804 break; 1805 } 1806 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 1807 break; 1808 1809 case DISCONNECTION_REQUEST: 1810 // find channel 1811 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1812 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1813 if (!channel) { 1814 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1815 break; 1816 } 1817 channel->remote_sig_id = sig_id; 1818 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1819 break; 1820 1821 #endif 1822 1823 case DISCONNECTION_RESPONSE: 1824 break; 1825 1826 default: 1827 // command unknown -> reject command 1828 return 0; 1829 } 1830 return 1; 1831 } 1832 #endif 1833 1834 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 1835 1836 l2cap_channel_t * l2cap_channel; 1837 (void) l2cap_channel; 1838 1839 // Get Channel ID 1840 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1841 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1842 1843 switch (channel_id) { 1844 1845 #ifdef ENABLE_CLASSIC 1846 case L2CAP_CID_SIGNALING: { 1847 uint16_t command_offset = 8; 1848 while (command_offset < size) { 1849 // handle signaling commands 1850 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1851 1852 // increment command_offset 1853 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1854 } 1855 break; 1856 } 1857 #endif 1858 1859 #ifdef ENABLE_BLE 1860 case L2CAP_CID_SIGNALING_LE: { 1861 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1862 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 1863 if (!valid){ 1864 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1865 } 1866 break; 1867 } 1868 #endif 1869 1870 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1871 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 1872 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1873 } 1874 break; 1875 1876 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1877 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 1878 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1879 } 1880 break; 1881 1882 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 1883 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 1884 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1885 } 1886 break; 1887 1888 default: 1889 #ifdef ENABLE_CLASSIC 1890 // Find channel for this channel_id and connection handle 1891 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 1892 if (l2cap_channel) { 1893 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1894 } 1895 #endif 1896 #ifdef ENABLE_LE_DATA_CHANNELS 1897 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 1898 if (l2cap_channel) { 1899 // credit counting 1900 if (l2cap_channel->credits_incoming == 0){ 1901 log_error("LE Data Channel packet received but no incoming credits"); 1902 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1903 break; 1904 } 1905 l2cap_channel->credits_incoming--; 1906 1907 // automatic credits 1908 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 1909 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 1910 } 1911 1912 // first fragment 1913 uint16_t pos = 0; 1914 if (!l2cap_channel->receive_sdu_len){ 1915 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 1916 l2cap_channel->receive_sdu_pos = 0; 1917 pos += 2; 1918 size -= 2; 1919 } 1920 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 1921 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 1922 // done? 1923 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 1924 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 1925 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 1926 l2cap_channel->receive_sdu_len = 0; 1927 } 1928 } else { 1929 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 1930 } 1931 #endif 1932 break; 1933 } 1934 1935 l2cap_run(); 1936 } 1937 1938 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1939 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 1940 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 1941 if (index < 0) return; 1942 fixed_channels[index].callback = the_packet_handler; 1943 } 1944 1945 #ifdef ENABLE_CLASSIC 1946 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1947 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 1948 channel->state = L2CAP_STATE_CLOSED; 1949 l2cap_emit_channel_closed(channel); 1950 // discard channel 1951 l2cap_stop_rtx(channel); 1952 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1953 btstack_memory_l2cap_channel_free(channel); 1954 } 1955 1956 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 1957 btstack_linked_list_iterator_t it; 1958 btstack_linked_list_iterator_init(&it, services); 1959 while (btstack_linked_list_iterator_has_next(&it)){ 1960 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 1961 if ( service->psm == psm){ 1962 return service; 1963 }; 1964 } 1965 return NULL; 1966 } 1967 1968 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 1969 return l2cap_get_service_internal(&l2cap_services, psm); 1970 } 1971 1972 1973 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 1974 1975 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1976 1977 // check for alread registered psm 1978 l2cap_service_t *service = l2cap_get_service(psm); 1979 if (service) { 1980 log_error("l2cap_register_service: PSM %u already registered", psm); 1981 return L2CAP_SERVICE_ALREADY_REGISTERED; 1982 } 1983 1984 // alloc structure 1985 service = btstack_memory_l2cap_service_get(); 1986 if (!service) { 1987 log_error("l2cap_register_service: no memory for l2cap_service_t"); 1988 return BTSTACK_MEMORY_ALLOC_FAILED; 1989 } 1990 1991 // fill in 1992 service->psm = psm; 1993 service->mtu = mtu; 1994 service->packet_handler = service_packet_handler; 1995 service->required_security_level = security_level; 1996 1997 // add to services list 1998 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 1999 2000 // enable page scan 2001 gap_connectable_control(1); 2002 2003 return 0; 2004 } 2005 2006 uint8_t l2cap_unregister_service(uint16_t psm){ 2007 2008 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 2009 2010 l2cap_service_t *service = l2cap_get_service(psm); 2011 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2012 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 2013 btstack_memory_l2cap_service_free(service); 2014 2015 // disable page scan when no services registered 2016 if (btstack_linked_list_empty(&l2cap_services)) { 2017 gap_connectable_control(0); 2018 } 2019 return 0; 2020 } 2021 #endif 2022 2023 2024 #ifdef ENABLE_LE_DATA_CHANNELS 2025 2026 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 2027 if (!channel->waiting_for_can_send_now) return; 2028 if (channel->send_sdu_buffer) return; 2029 channel->waiting_for_can_send_now = 0; 2030 log_info("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 2031 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 2032 } 2033 2034 // 1BH2222 2035 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 2036 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", 2037 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 2038 uint8_t event[19]; 2039 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 2040 event[1] = sizeof(event) - 2; 2041 event[2] = channel->address_type; 2042 reverse_bd_addr(channel->address, &event[3]); 2043 little_endian_store_16(event, 9, channel->con_handle); 2044 little_endian_store_16(event, 11, channel->psm); 2045 little_endian_store_16(event, 13, channel->local_cid); 2046 little_endian_store_16(event, 15, channel->remote_cid); 2047 little_endian_store_16(event, 17, channel->remote_mtu); 2048 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2049 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2050 } 2051 // 11BH22222 2052 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 2053 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", 2054 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 2055 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 2056 uint8_t event[23]; 2057 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 2058 event[1] = sizeof(event) - 2; 2059 event[2] = status; 2060 event[3] = channel->address_type; 2061 reverse_bd_addr(channel->address, &event[4]); 2062 little_endian_store_16(event, 10, channel->con_handle); 2063 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 2064 little_endian_store_16(event, 13, channel->psm); 2065 little_endian_store_16(event, 15, channel->local_cid); 2066 little_endian_store_16(event, 17, channel->remote_cid); 2067 little_endian_store_16(event, 19, channel->local_mtu); 2068 little_endian_store_16(event, 21, channel->remote_mtu); 2069 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2070 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2071 } 2072 2073 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 2074 btstack_linked_list_iterator_t it; 2075 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2076 while (btstack_linked_list_iterator_has_next(&it)){ 2077 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2078 if ( channel->local_cid == local_cid) { 2079 return channel; 2080 } 2081 } 2082 return NULL; 2083 } 2084 2085 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2086 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 2087 channel->state = L2CAP_STATE_CLOSED; 2088 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 2089 // discard channel 2090 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2091 btstack_memory_l2cap_channel_free(channel); 2092 } 2093 2094 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 2095 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 2096 } 2097 2098 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 2099 2100 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 2101 2102 // check for alread registered psm 2103 l2cap_service_t *service = l2cap_le_get_service(psm); 2104 if (service) { 2105 return L2CAP_SERVICE_ALREADY_REGISTERED; 2106 } 2107 2108 // alloc structure 2109 service = btstack_memory_l2cap_service_get(); 2110 if (!service) { 2111 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 2112 return BTSTACK_MEMORY_ALLOC_FAILED; 2113 } 2114 2115 // fill in 2116 service->psm = psm; 2117 service->mtu = 0; 2118 service->packet_handler = packet_handler; 2119 service->required_security_level = security_level; 2120 2121 // add to services list 2122 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 2123 2124 // done 2125 return 0; 2126 } 2127 2128 uint8_t l2cap_le_unregister_service(uint16_t psm) { 2129 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 2130 l2cap_service_t *service = l2cap_le_get_service(psm); 2131 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2132 2133 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 2134 btstack_memory_l2cap_service_free(service); 2135 return 0; 2136 } 2137 2138 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 2139 // get channel 2140 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2141 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2142 2143 // validate state 2144 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2145 return ERROR_CODE_COMMAND_DISALLOWED; 2146 } 2147 2148 // set state accept connection 2149 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 2150 channel->receive_sdu_buffer = receive_sdu_buffer; 2151 channel->local_mtu = mtu; 2152 channel->new_credits_incoming = initial_credits; 2153 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2154 2155 // test 2156 // channel->new_credits_incoming = 1; 2157 2158 // go 2159 l2cap_run(); 2160 return 0; 2161 } 2162 2163 /** 2164 * @brief Deny incoming LE Data Channel connection due to resource constraints 2165 * @param local_cid L2CAP LE Data Channel Identifier 2166 */ 2167 2168 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 2169 // get channel 2170 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2171 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2172 2173 // validate state 2174 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2175 return ERROR_CODE_COMMAND_DISALLOWED; 2176 } 2177 2178 // set state decline connection 2179 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 2180 channel->reason = 0x04; // no resources available 2181 l2cap_run(); 2182 return 0; 2183 } 2184 2185 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 2186 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 2187 uint16_t * out_local_cid) { 2188 2189 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 2190 2191 2192 hci_connection_t * connection = hci_connection_for_handle(con_handle); 2193 if (!connection) { 2194 log_error("no hci_connection for handle 0x%04x", con_handle); 2195 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 2196 } 2197 2198 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 2199 if (!channel) { 2200 return BTSTACK_MEMORY_ALLOC_FAILED; 2201 } 2202 log_info("l2cap_le_create_channel %p", channel); 2203 2204 // store local_cid 2205 if (out_local_cid){ 2206 *out_local_cid = channel->local_cid; 2207 } 2208 2209 // provide buffer 2210 channel->con_handle = con_handle; 2211 channel->receive_sdu_buffer = receive_sdu_buffer; 2212 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 2213 channel->new_credits_incoming = initial_credits; 2214 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2215 2216 // add to connections list 2217 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2218 2219 // go 2220 l2cap_run(); 2221 return 0; 2222 } 2223 2224 /** 2225 * @brief Provide credtis for LE Data Channel 2226 * @param local_cid L2CAP LE Data Channel Identifier 2227 * @param credits Number additional credits for peer 2228 */ 2229 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2230 2231 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2232 if (!channel) { 2233 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2234 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2235 } 2236 2237 // check state 2238 if (channel->state != L2CAP_STATE_OPEN){ 2239 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 2240 } 2241 2242 // assert incoming credits + credits <= 0xffff 2243 uint32_t total_credits = channel->credits_incoming; 2244 total_credits += channel->new_credits_incoming; 2245 total_credits += credits; 2246 if (total_credits > 0xffff){ 2247 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 2248 channel->new_credits_incoming, credits); 2249 } 2250 2251 // set credits_granted 2252 channel->new_credits_incoming += credits; 2253 2254 // go 2255 l2cap_run(); 2256 return 0; 2257 } 2258 2259 /** 2260 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2261 * @param local_cid L2CAP LE Data Channel Identifier 2262 */ 2263 int l2cap_le_can_send_now(uint16_t local_cid){ 2264 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2265 if (!channel) { 2266 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2267 return 0; 2268 } 2269 2270 // check state 2271 if (channel->state != L2CAP_STATE_OPEN) return 0; 2272 2273 // check queue 2274 if (channel->send_sdu_buffer) return 0; 2275 2276 // fine, go ahead 2277 return 1; 2278 } 2279 2280 /** 2281 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2282 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2283 * so packet handler should be ready to handle it 2284 * @param local_cid L2CAP LE Data Channel Identifier 2285 */ 2286 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2287 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2288 if (!channel) { 2289 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 2290 return 0; 2291 } 2292 channel->waiting_for_can_send_now = 1; 2293 l2cap_le_notify_channel_can_send(channel); 2294 return 0; 2295 } 2296 2297 /** 2298 * @brief Send data via LE Data Channel 2299 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2300 * @param local_cid L2CAP LE Data Channel Identifier 2301 * @param data data to send 2302 * @param size data size 2303 */ 2304 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2305 2306 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2307 if (!channel) { 2308 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2309 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2310 } 2311 2312 if (len > channel->remote_mtu){ 2313 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2314 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2315 } 2316 2317 if (channel->send_sdu_buffer){ 2318 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2319 return BTSTACK_ACL_BUFFERS_FULL; 2320 } 2321 2322 channel->send_sdu_buffer = data; 2323 channel->send_sdu_len = len; 2324 channel->send_sdu_pos = 0; 2325 2326 l2cap_run(); 2327 return 0; 2328 } 2329 2330 /** 2331 * @brief Disconnect from LE Data Channel 2332 * @param local_cid L2CAP LE Data Channel Identifier 2333 */ 2334 uint8_t l2cap_le_disconnect(uint16_t local_cid) 2335 { 2336 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2337 if (!channel) { 2338 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2339 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2340 } 2341 2342 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2343 l2cap_run(); 2344 return 0; 2345 } 2346 2347 #endif 2348