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 #ifdef ENABLE_CLASSIC 191 gap_connectable_control(0); // no services yet 192 #endif 193 } 194 195 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 196 l2cap_event_packet_handler = handler; 197 } 198 199 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ 200 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 201 if (index < 0) return; 202 fixed_channels[index].waiting_for_can_send_now = 1; 203 l2cap_notify_channel_can_send(); 204 } 205 206 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ 207 return hci_can_send_acl_packet_now(con_handle); 208 } 209 210 uint8_t *l2cap_get_outgoing_buffer(void){ 211 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 212 } 213 214 int l2cap_reserve_packet_buffer(void){ 215 return hci_reserve_packet_buffer(); 216 } 217 218 void l2cap_release_packet_buffer(void){ 219 hci_release_packet_buffer(); 220 } 221 222 static void l2cap_setup_header(uint8_t * acl_buffer, hci_con_handle_t con_handle, uint16_t remote_cid, uint16_t len){ 223 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 224 225 // 0 - Connection handle : PB=pb : BC=00 226 little_endian_store_16(acl_buffer, 0, con_handle | (pb << 12) | (0 << 14)); 227 // 2 - ACL length 228 little_endian_store_16(acl_buffer, 2, len + 4); 229 // 4 - L2CAP packet length 230 little_endian_store_16(acl_buffer, 4, len + 0); 231 // 6 - L2CAP channel DEST 232 little_endian_store_16(acl_buffer, 6, remote_cid); 233 } 234 235 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 236 237 if (!hci_is_packet_buffer_reserved()){ 238 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 239 return BTSTACK_ACL_BUFFERS_FULL; 240 } 241 242 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 243 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 244 return BTSTACK_ACL_BUFFERS_FULL; 245 } 246 247 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 248 249 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 250 l2cap_setup_header(acl_buffer, con_handle, cid, len); 251 // send 252 return hci_send_acl_packet_buffer(len+8); 253 } 254 255 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 256 257 if (!hci_can_send_acl_packet_now(con_handle)){ 258 log_info("l2cap_send cid 0x%02x, cannot send", cid); 259 return BTSTACK_ACL_BUFFERS_FULL; 260 } 261 262 hci_reserve_packet_buffer(); 263 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 264 265 memcpy(&acl_buffer[8], data, len); 266 267 return l2cap_send_prepared_connectionless(con_handle, cid, len); 268 } 269 270 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { 271 log_info("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); 272 uint8_t event[4]; 273 event[0] = L2CAP_EVENT_CAN_SEND_NOW; 274 event[1] = sizeof(event) - 2; 275 little_endian_store_16(event, 2, channel); 276 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 277 packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); 278 } 279 280 #ifdef L2CAP_USES_CHANNELS 281 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 282 (* (channel->packet_handler))(type, channel->local_cid, data, size); 283 } 284 285 static void l2cap_emit_simple_event_with_cid(l2cap_channel_t * channel, uint8_t event_code){ 286 uint8_t event[4]; 287 event[0] = event_code; 288 event[1] = sizeof(event) - 2; 289 little_endian_store_16(event, 2, channel->local_cid); 290 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 291 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 292 } 293 #endif 294 295 #ifdef ENABLE_CLASSIC 296 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 297 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", 298 status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 299 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 300 uint8_t event[23]; 301 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 302 event[1] = sizeof(event) - 2; 303 event[2] = status; 304 reverse_bd_addr(channel->address, &event[3]); 305 little_endian_store_16(event, 9, channel->con_handle); 306 little_endian_store_16(event, 11, channel->psm); 307 little_endian_store_16(event, 13, channel->local_cid); 308 little_endian_store_16(event, 15, channel->remote_cid); 309 little_endian_store_16(event, 17, channel->local_mtu); 310 little_endian_store_16(event, 19, channel->remote_mtu); 311 little_endian_store_16(event, 21, channel->flush_timeout); 312 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 313 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 314 } 315 316 static void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 317 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 318 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 319 } 320 321 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel) { 322 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 323 bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); 324 uint8_t event[16]; 325 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 326 event[1] = sizeof(event) - 2; 327 reverse_bd_addr(channel->address, &event[2]); 328 little_endian_store_16(event, 8, channel->con_handle); 329 little_endian_store_16(event, 10, channel->psm); 330 little_endian_store_16(event, 12, channel->local_cid); 331 little_endian_store_16(event, 14, channel->remote_cid); 332 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 333 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 334 } 335 336 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 337 btstack_linked_list_iterator_t it; 338 btstack_linked_list_iterator_init(&it, &l2cap_channels); 339 while (btstack_linked_list_iterator_has_next(&it)){ 340 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 341 if ( channel->local_cid == local_cid) { 342 return channel; 343 } 344 } 345 return NULL; 346 } 347 348 /// 349 350 void l2cap_request_can_send_now_event(uint16_t local_cid){ 351 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 352 if (!channel) return; 353 channel->waiting_for_can_send_now = 1; 354 l2cap_notify_channel_can_send(); 355 } 356 357 int l2cap_can_send_packet_now(uint16_t local_cid){ 358 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 359 if (!channel) return 0; 360 return hci_can_send_acl_packet_now(channel->con_handle); 361 } 362 363 int l2cap_can_send_prepared_packet_now(uint16_t local_cid){ 364 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 365 if (!channel) return 0; 366 return hci_can_send_prepared_acl_packet_now(channel->con_handle); 367 } 368 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 369 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 370 if (channel) { 371 return channel->remote_mtu; 372 } 373 return 0; 374 } 375 376 static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ 377 btstack_linked_list_iterator_t it; 378 btstack_linked_list_iterator_init(&it, &l2cap_channels); 379 while (btstack_linked_list_iterator_has_next(&it)){ 380 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 381 if ( &channel->rtx == ts) { 382 return channel; 383 } 384 } 385 return NULL; 386 } 387 388 static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ 389 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 390 if (!channel) return; 391 392 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 393 394 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 395 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 396 // notify client 397 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 398 399 // discard channel 400 // no need to stop timer here, it is removed from list during timer callback 401 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 402 btstack_memory_l2cap_channel_free(channel); 403 } 404 405 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 406 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 407 btstack_run_loop_remove_timer(&channel->rtx); 408 } 409 410 static void l2cap_start_rtx(l2cap_channel_t * channel){ 411 l2cap_stop_rtx(channel); 412 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 413 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 414 btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 415 btstack_run_loop_add_timer(&channel->rtx); 416 } 417 418 static void l2cap_start_ertx(l2cap_channel_t * channel){ 419 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 420 l2cap_stop_rtx(channel); 421 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 422 btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 423 btstack_run_loop_add_timer(&channel->rtx); 424 } 425 426 void l2cap_require_security_level_2_for_outgoing_sdp(void){ 427 require_security_level2_for_outgoing_sdp = 1; 428 } 429 430 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 431 return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); 432 } 433 434 static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 435 if (!hci_can_send_acl_packet_now(handle)){ 436 log_info("l2cap_send_signaling_packet, cannot send"); 437 return BTSTACK_ACL_BUFFERS_FULL; 438 } 439 440 // log_info("l2cap_send_signaling_packet type %u", cmd); 441 hci_reserve_packet_buffer(); 442 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 443 va_list argptr; 444 va_start(argptr, identifier); 445 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 446 va_end(argptr); 447 // log_info("l2cap_send_signaling_packet con %u!", handle); 448 return hci_send_acl_packet_buffer(len); 449 } 450 451 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 452 453 if (!hci_is_packet_buffer_reserved()){ 454 log_error("l2cap_send_prepared called without reserving packet first"); 455 return BTSTACK_ACL_BUFFERS_FULL; 456 } 457 458 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 459 if (!channel) { 460 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 461 return -1; // TODO: define error 462 } 463 464 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 465 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 466 return BTSTACK_ACL_BUFFERS_FULL; 467 } 468 469 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 470 471 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 472 l2cap_setup_header(acl_buffer, channel->con_handle, channel->remote_cid, len); 473 // send 474 return hci_send_acl_packet_buffer(len+8); 475 } 476 477 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 478 479 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 480 if (!channel) { 481 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 482 return -1; // TODO: define error 483 } 484 485 if (len > channel->remote_mtu){ 486 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 487 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 488 } 489 490 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 491 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 492 return BTSTACK_ACL_BUFFERS_FULL; 493 } 494 495 hci_reserve_packet_buffer(); 496 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 497 498 memcpy(&acl_buffer[8], data, len); 499 500 return l2cap_send_prepared(local_cid, len); 501 } 502 503 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ 504 return l2cap_send_signaling_packet(con_handle, ECHO_REQUEST, 0x77, len, data); 505 } 506 507 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 508 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 509 } 510 511 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 512 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 513 } 514 #endif 515 516 517 #ifdef ENABLE_BLE 518 static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 519 520 if (!hci_can_send_acl_packet_now(handle)){ 521 log_info("l2cap_send_le_signaling_packet, cannot send"); 522 return BTSTACK_ACL_BUFFERS_FULL; 523 } 524 525 // log_info("l2cap_send_le_signaling_packet type %u", cmd); 526 hci_reserve_packet_buffer(); 527 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 528 va_list argptr; 529 va_start(argptr, identifier); 530 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 531 va_end(argptr); 532 // log_info("l2cap_send_le_signaling_packet con %u!", handle); 533 return hci_send_acl_packet_buffer(len); 534 } 535 #endif 536 537 uint16_t l2cap_max_mtu(void){ 538 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 539 } 540 541 uint16_t l2cap_max_le_mtu(void){ 542 return l2cap_max_mtu(); 543 } 544 545 // MARK: L2CAP_RUN 546 // process outstanding signaling tasks 547 static void l2cap_run(void){ 548 549 // log_info("l2cap_run: entered"); 550 551 // check pending signaling responses 552 while (signaling_responses_pending){ 553 554 hci_con_handle_t handle = signaling_responses[0].handle; 555 556 if (!hci_can_send_acl_packet_now(handle)) break; 557 558 uint8_t sig_id = signaling_responses[0].sig_id; 559 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 560 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 561 uint8_t response_code = signaling_responses[0].code; 562 563 // avoid warnings 564 (void) infoType; 565 566 // remove first item before sending (to avoid sending response mutliple times) 567 signaling_responses_pending--; 568 int i; 569 for (i=0; i < signaling_responses_pending; i++){ 570 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 571 } 572 573 switch (response_code){ 574 #ifdef ENABLE_CLASSIC 575 case CONNECTION_REQUEST: 576 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 577 // also disconnect if result is 0x0003 - security blocked 578 if (result == 0x0003){ 579 hci_disconnect_security_block(handle); 580 } 581 break; 582 case ECHO_REQUEST: 583 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 584 break; 585 case INFORMATION_REQUEST: 586 switch (infoType){ 587 case 1: { // Connectionless MTU 588 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 589 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 590 } 591 break; 592 case 2: { // Extended Features Supported 593 // extended features request supported, features: fixed channels, unicast connectionless data reception 594 uint32_t features = 0x280; 595 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 596 } 597 break; 598 case 3: { // Fixed Channels Supported 599 uint8_t map[8]; 600 memset(map, 0, 8); 601 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 602 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 603 } 604 break; 605 default: 606 // all other types are not supported 607 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 608 break; 609 } 610 break; 611 case COMMAND_REJECT: 612 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 613 break; 614 #endif 615 #ifdef ENABLE_BLE 616 case LE_CREDIT_BASED_CONNECTION_REQUEST: 617 l2cap_send_le_signaling_packet(handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, sig_id, 0, 0, 0, 0, result); 618 break; 619 case COMMAND_REJECT_LE: 620 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 621 break; 622 #endif 623 default: 624 // should not happen 625 break; 626 } 627 } 628 629 btstack_linked_list_iterator_t it; 630 (void) it; 631 632 #ifdef ENABLE_CLASSIC 633 uint8_t config_options[4]; 634 btstack_linked_list_iterator_init(&it, &l2cap_channels); 635 while (btstack_linked_list_iterator_has_next(&it)){ 636 637 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 638 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 639 switch (channel->state){ 640 641 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 642 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 643 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 644 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 645 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 646 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 647 } 648 break; 649 650 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 651 if (!hci_can_send_command_packet_now()) break; 652 // send connection request - set state first 653 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 654 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 655 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 656 break; 657 658 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 659 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 660 channel->state = L2CAP_STATE_INVALID; 661 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 662 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 663 l2cap_stop_rtx(channel); 664 btstack_linked_list_iterator_remove(&it); 665 btstack_memory_l2cap_channel_free(channel); 666 break; 667 668 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 669 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 670 channel->state = L2CAP_STATE_CONFIG; 671 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 672 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 673 break; 674 675 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 676 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 677 // success, start l2cap handshake 678 channel->local_sig_id = l2cap_next_sig_id(); 679 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 680 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 681 l2cap_start_rtx(channel); 682 break; 683 684 case L2CAP_STATE_CONFIG: 685 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 686 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 687 uint16_t flags = 0; 688 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 689 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 690 flags = 1; 691 } else { 692 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 693 } 694 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 695 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 696 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 697 config_options[0] = 1; // MTU 698 config_options[1] = 2; // len param 699 little_endian_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 700 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 701 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 702 } else { 703 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 704 } 705 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 706 } 707 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 708 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 709 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 710 channel->local_sig_id = l2cap_next_sig_id(); 711 config_options[0] = 1; // MTU 712 config_options[1] = 2; // len param 713 little_endian_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 714 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 715 l2cap_start_rtx(channel); 716 } 717 if (l2cap_channel_ready_for_open(channel)){ 718 channel->state = L2CAP_STATE_OPEN; 719 l2cap_emit_channel_opened(channel, 0); // success 720 } 721 break; 722 723 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 724 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 725 channel->state = L2CAP_STATE_INVALID; 726 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 727 // 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 :) 728 l2cap_finialize_channel_close(channel); // -- remove from list 729 break; 730 731 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 732 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 733 channel->local_sig_id = l2cap_next_sig_id(); 734 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 735 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 736 break; 737 default: 738 break; 739 } 740 } 741 #endif 742 743 #ifdef ENABLE_LE_DATA_CHANNELS 744 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 745 while (btstack_linked_list_iterator_has_next(&it)){ 746 uint8_t * acl_buffer; 747 uint8_t * l2cap_payload; 748 uint16_t pos; 749 uint16_t payload_size; 750 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 751 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 752 switch (channel->state){ 753 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 754 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 755 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 756 // le psm, source cid, mtu, mps, initial credits 757 channel->local_sig_id = l2cap_next_sig_id(); 758 channel->credits_incoming = channel->new_credits_incoming; 759 channel->new_credits_incoming = 0; 760 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); 761 break; 762 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 763 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 764 // TODO: support larger MPS 765 channel->state = L2CAP_STATE_OPEN; 766 channel->credits_incoming = channel->new_credits_incoming; 767 channel->new_credits_incoming = 0; 768 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); 769 // notify client 770 l2cap_emit_le_channel_opened(channel, 0); 771 break; 772 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 773 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 774 channel->state = L2CAP_STATE_INVALID; 775 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); 776 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 777 l2cap_stop_rtx(channel); 778 btstack_linked_list_iterator_remove(&it); 779 btstack_memory_l2cap_channel_free(channel); 780 break; 781 case L2CAP_STATE_OPEN: 782 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 783 784 // send credits 785 if (channel->new_credits_incoming){ 786 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 787 channel->local_sig_id = l2cap_next_sig_id(); 788 uint16_t new_credits = channel->new_credits_incoming; 789 channel->new_credits_incoming = 0; 790 channel->credits_incoming += new_credits; 791 l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); 792 break; 793 } 794 795 // send data 796 if (!channel->send_sdu_buffer) break; 797 if (!channel->credits_outgoing) break; 798 799 // send part of SDU 800 hci_reserve_packet_buffer(); 801 acl_buffer = hci_get_outgoing_packet_buffer(); 802 l2cap_payload = acl_buffer + 8; 803 pos = 0; 804 if (!channel->send_sdu_pos){ 805 // store SDU len 806 channel->send_sdu_pos += 2; 807 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 808 pos += 2; 809 } 810 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 811 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); 812 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 813 pos += payload_size; 814 channel->send_sdu_pos += payload_size; 815 l2cap_setup_header(acl_buffer, channel->con_handle, channel->remote_cid, pos); 816 // done 817 818 channel->credits_outgoing--; 819 820 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 821 channel->send_sdu_buffer = NULL; 822 // send done event 823 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_PACKET_SENT); 824 // inform about can send now 825 l2cap_le_notify_channel_can_send(channel); 826 } 827 hci_send_acl_packet_buffer(8 + pos); 828 break; 829 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 830 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 831 channel->local_sig_id = l2cap_next_sig_id(); 832 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 833 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 834 break; 835 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 836 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 837 channel->state = L2CAP_STATE_INVALID; 838 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 839 l2cap_le_finialize_channel_close(channel); // -- remove from list 840 break; 841 default: 842 break; 843 } 844 } 845 #endif 846 847 #ifdef ENABLE_BLE 848 // send l2cap con paramter update if necessary 849 hci_connections_get_iterator(&it); 850 while(btstack_linked_list_iterator_has_next(&it)){ 851 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 852 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 853 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 854 switch (connection->le_con_parameter_update_state){ 855 case CON_PARAMETER_UPDATE_SEND_REQUEST: 856 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 857 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 858 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 859 break; 860 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 861 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 862 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 863 break; 864 case CON_PARAMETER_UPDATE_DENY: 865 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 866 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 867 break; 868 default: 869 break; 870 } 871 } 872 #endif 873 874 // log_info("l2cap_run: exit"); 875 } 876 877 #ifdef ENABLE_CLASSIC 878 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 879 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 880 log_info("l2cap_handle_connection_complete expected state"); 881 // success, start l2cap handshake 882 channel->con_handle = con_handle; 883 // check remote SSP feature first 884 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 885 } 886 } 887 888 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 889 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 890 891 // we have been waiting for remote supported features, if both support SSP, 892 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)); 893 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 894 // request security level 2 895 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 896 gap_request_security_level(channel->con_handle, LEVEL_2); 897 return; 898 } 899 // fine, go ahead 900 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 901 } 902 #endif 903 904 #ifdef L2CAP_USES_CHANNELS 905 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 906 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 907 908 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 909 if (!channel) { 910 return NULL; 911 } 912 913 // Init memory (make valgrind happy) 914 memset(channel, 0, sizeof(l2cap_channel_t)); 915 916 // fill in 917 channel->packet_handler = packet_handler; 918 bd_addr_copy(channel->address, address); 919 channel->address_type = address_type; 920 channel->psm = psm; 921 channel->local_mtu = local_mtu; 922 channel->remote_mtu = L2CAP_MINIMAL_MTU; 923 channel->required_security_level = security_level; 924 925 // 926 channel->local_cid = l2cap_next_local_cid(); 927 channel->con_handle = 0; 928 929 // set initial state 930 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 931 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 932 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 933 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 934 return channel; 935 } 936 #endif 937 938 #ifdef ENABLE_CLASSIC 939 940 /** 941 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 942 * @param packet_handler 943 * @param address 944 * @param psm 945 * @param mtu 946 * @param local_cid 947 */ 948 949 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){ 950 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, local_mtu); 951 952 if (local_mtu > l2cap_max_mtu()) { 953 local_mtu = l2cap_max_mtu(); 954 } 955 956 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 957 if (!channel) { 958 return BTSTACK_MEMORY_ALLOC_FAILED; 959 } 960 961 // add to connections list 962 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 963 964 // store local_cid 965 if (out_local_cid){ 966 *out_local_cid = channel->local_cid; 967 } 968 969 // check if hci connection is already usable 970 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 971 if (conn){ 972 log_info("l2cap_create_channel, hci connection already exists"); 973 l2cap_handle_connection_complete(conn->con_handle, channel); 974 // check if remote supported fearures are already received 975 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 976 l2cap_handle_remote_supported_features_received(channel); 977 } 978 } 979 980 l2cap_run(); 981 982 return 0; 983 } 984 985 void 986 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 987 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 988 // find channel for local_cid 989 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 990 if (channel) { 991 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 992 } 993 // process 994 l2cap_run(); 995 } 996 997 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 998 btstack_linked_list_iterator_t it; 999 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1000 while (btstack_linked_list_iterator_has_next(&it)){ 1001 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1002 if ( bd_addr_cmp( channel->address, address) != 0) continue; 1003 // channel for this address found 1004 switch (channel->state){ 1005 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1006 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1007 // failure, forward error code 1008 l2cap_emit_channel_opened(channel, status); 1009 // discard channel 1010 l2cap_stop_rtx(channel); 1011 btstack_linked_list_iterator_remove(&it); 1012 btstack_memory_l2cap_channel_free(channel); 1013 break; 1014 default: 1015 break; 1016 } 1017 } 1018 } 1019 1020 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1021 btstack_linked_list_iterator_t it; 1022 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1023 while (btstack_linked_list_iterator_has_next(&it)){ 1024 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1025 if ( ! bd_addr_cmp( channel->address, address) ){ 1026 l2cap_handle_connection_complete(handle, channel); 1027 } 1028 } 1029 // process 1030 l2cap_run(); 1031 } 1032 #endif 1033 1034 static void l2cap_notify_channel_can_send(void){ 1035 1036 #ifdef ENABLE_CLASSIC 1037 btstack_linked_list_iterator_t it; 1038 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1039 while (btstack_linked_list_iterator_has_next(&it)){ 1040 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1041 if (!channel->waiting_for_can_send_now) continue; 1042 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1043 channel->waiting_for_can_send_now = 0; 1044 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1045 } 1046 #endif 1047 1048 int i; 1049 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1050 if (!fixed_channels[i].callback) continue; 1051 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1052 int can_send; 1053 if (l2cap_fixed_channel_table_index_is_le(i)){ 1054 can_send = hci_can_send_acl_le_packet_now(); 1055 } else { 1056 can_send = hci_can_send_acl_classic_packet_now(); 1057 } 1058 if (!can_send) continue; 1059 fixed_channels[i].waiting_for_can_send_now = 0; 1060 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1061 } 1062 } 1063 1064 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1065 1066 bd_addr_t address; 1067 hci_con_handle_t handle; 1068 int hci_con_used; 1069 btstack_linked_list_iterator_t it; 1070 1071 // avoid unused warnings 1072 (void) address; 1073 (void) hci_con_used; 1074 (void) it; 1075 1076 switch(hci_event_packet_get_type(packet)){ 1077 1078 // Notify channel packet handler if they can send now 1079 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1080 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1081 l2cap_run(); // try sending signaling packets first 1082 l2cap_notify_channel_can_send(); 1083 break; 1084 1085 case HCI_EVENT_COMMAND_STATUS: 1086 l2cap_run(); // try sending signaling packets first 1087 break; 1088 1089 #ifdef ENABLE_CLASSIC 1090 // handle connection complete events 1091 case HCI_EVENT_CONNECTION_COMPLETE: 1092 reverse_bd_addr(&packet[5], address); 1093 if (packet[2] == 0){ 1094 handle = little_endian_read_16(packet, 3); 1095 l2cap_handle_connection_success_for_addr(address, handle); 1096 } else { 1097 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1098 } 1099 break; 1100 1101 // handle successful create connection cancel command 1102 case HCI_EVENT_COMMAND_COMPLETE: 1103 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1104 if (packet[5] == 0){ 1105 reverse_bd_addr(&packet[6], address); 1106 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1107 l2cap_handle_connection_failed_for_addr(address, 0x16); 1108 } 1109 } 1110 l2cap_run(); // try sending signaling packets first 1111 break; 1112 #endif 1113 1114 // handle disconnection complete events 1115 case HCI_EVENT_DISCONNECTION_COMPLETE: 1116 // send l2cap disconnect events for all channels on this handle and free them 1117 handle = little_endian_read_16(packet, 3); 1118 #ifdef ENABLE_CLASSIC 1119 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1120 while (btstack_linked_list_iterator_has_next(&it)){ 1121 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1122 if (channel->con_handle != handle) continue; 1123 l2cap_emit_channel_closed(channel); 1124 l2cap_stop_rtx(channel); 1125 btstack_linked_list_iterator_remove(&it); 1126 btstack_memory_l2cap_channel_free(channel); 1127 } 1128 #endif 1129 #ifdef ENABLE_LE_DATA_CHANNELS 1130 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1131 while (btstack_linked_list_iterator_has_next(&it)){ 1132 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1133 if (channel->con_handle != handle) continue; 1134 l2cap_emit_channel_closed(channel); 1135 btstack_linked_list_iterator_remove(&it); 1136 btstack_memory_l2cap_channel_free(channel); 1137 } 1138 #endif 1139 break; 1140 1141 // HCI Connection Timeouts 1142 #ifdef ENABLE_CLASSIC 1143 case L2CAP_EVENT_TIMEOUT_CHECK: 1144 handle = little_endian_read_16(packet, 2); 1145 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1146 if (hci_authentication_active_for_handle(handle)) break; 1147 hci_con_used = 0; 1148 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1149 while (btstack_linked_list_iterator_has_next(&it)){ 1150 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1151 if (channel->con_handle != handle) continue; 1152 hci_con_used = 1; 1153 break; 1154 } 1155 if (hci_con_used) break; 1156 if (!hci_can_send_command_packet_now()) break; 1157 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1158 break; 1159 1160 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1161 handle = little_endian_read_16(packet, 3); 1162 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1163 while (btstack_linked_list_iterator_has_next(&it)){ 1164 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1165 if (channel->con_handle != handle) continue; 1166 l2cap_handle_remote_supported_features_received(channel); 1167 break; 1168 } 1169 break; 1170 1171 case GAP_EVENT_SECURITY_LEVEL: 1172 handle = little_endian_read_16(packet, 2); 1173 log_info("l2cap - security level update"); 1174 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1175 while (btstack_linked_list_iterator_has_next(&it)){ 1176 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1177 if (channel->con_handle != handle) continue; 1178 1179 log_info("l2cap - state %u", channel->state); 1180 1181 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1182 gap_security_level_t required_level = channel->required_security_level; 1183 1184 switch (channel->state){ 1185 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1186 if (actual_level >= required_level){ 1187 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1188 l2cap_emit_incoming_connection(channel); 1189 } else { 1190 channel->reason = 0x0003; // security block 1191 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1192 } 1193 break; 1194 1195 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1196 if (actual_level >= required_level){ 1197 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1198 } else { 1199 // disconnnect, authentication not good enough 1200 hci_disconnect_security_block(handle); 1201 } 1202 break; 1203 1204 default: 1205 break; 1206 } 1207 } 1208 break; 1209 #endif 1210 1211 default: 1212 break; 1213 } 1214 1215 l2cap_run(); 1216 } 1217 1218 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 1219 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1220 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1221 signaling_responses[signaling_responses_pending].handle = handle; 1222 signaling_responses[signaling_responses_pending].code = code; 1223 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1224 signaling_responses[signaling_responses_pending].data = data; 1225 signaling_responses_pending++; 1226 l2cap_run(); 1227 } 1228 } 1229 1230 #ifdef ENABLE_CLASSIC 1231 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1232 channel->remote_sig_id = identifier; 1233 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1234 l2cap_run(); 1235 } 1236 1237 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1238 1239 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1240 l2cap_service_t *service = l2cap_get_service(psm); 1241 if (!service) { 1242 // 0x0002 PSM not supported 1243 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 1244 return; 1245 } 1246 1247 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1248 if (!hci_connection) { 1249 // 1250 log_error("no hci_connection for handle %u", handle); 1251 return; 1252 } 1253 1254 // alloc structure 1255 // log_info("l2cap_handle_connection_request register channel"); 1256 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1257 psm, service->mtu, service->required_security_level); 1258 if (!channel){ 1259 // 0x0004 No resources available 1260 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 1261 return; 1262 } 1263 1264 channel->con_handle = handle; 1265 channel->remote_cid = source_cid; 1266 channel->remote_sig_id = sig_id; 1267 1268 // limit local mtu to max acl packet length - l2cap header 1269 if (channel->local_mtu > l2cap_max_mtu()) { 1270 channel->local_mtu = l2cap_max_mtu(); 1271 } 1272 1273 // set initial state 1274 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1275 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1276 1277 // add to connections list 1278 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1279 1280 // assert security requirements 1281 gap_request_security_level(handle, channel->required_security_level); 1282 } 1283 1284 void l2cap_accept_connection(uint16_t local_cid){ 1285 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1286 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1287 if (!channel) { 1288 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1289 return; 1290 } 1291 1292 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1293 1294 // process 1295 l2cap_run(); 1296 } 1297 1298 void l2cap_decline_connection(uint16_t local_cid){ 1299 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1300 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1301 if (!channel) { 1302 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1303 return; 1304 } 1305 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1306 channel->reason = 0x04; // no resources available 1307 l2cap_run(); 1308 } 1309 1310 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1311 1312 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1313 1314 uint16_t flags = little_endian_read_16(command, 6); 1315 if (flags & 1) { 1316 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1317 } 1318 1319 // accept the other's configuration options 1320 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1321 uint16_t pos = 8; 1322 while (pos < end_pos){ 1323 uint8_t option_hint = command[pos] >> 7; 1324 uint8_t option_type = command[pos] & 0x7f; 1325 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1326 pos++; 1327 uint8_t length = command[pos++]; 1328 // MTU { type(8): 1, len(8):2, MTU(16) } 1329 if (option_type == 1 && length == 2){ 1330 channel->remote_mtu = little_endian_read_16(command, pos); 1331 // log_info("l2cap cid 0x%02x, remote mtu %u", channel->local_cid, channel->remote_mtu); 1332 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1333 } 1334 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1335 if (option_type == 2 && length == 2){ 1336 channel->flush_timeout = little_endian_read_16(command, pos); 1337 } 1338 // check for unknown options 1339 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1340 log_info("l2cap cid %u, unknown options", channel->local_cid); 1341 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1342 } 1343 pos += length; 1344 } 1345 } 1346 1347 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1348 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1349 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1350 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1351 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1352 if (channel->state == L2CAP_STATE_OPEN) return 0; 1353 return 1; 1354 } 1355 1356 1357 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1358 1359 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1360 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1361 uint16_t result = 0; 1362 1363 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1364 1365 // handle DISCONNECT REQUESTS seperately 1366 if (code == DISCONNECTION_REQUEST){ 1367 switch (channel->state){ 1368 case L2CAP_STATE_CONFIG: 1369 case L2CAP_STATE_OPEN: 1370 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1371 case L2CAP_STATE_WAIT_DISCONNECT: 1372 l2cap_handle_disconnect_request(channel, identifier); 1373 break; 1374 1375 default: 1376 // ignore in other states 1377 break; 1378 } 1379 return; 1380 } 1381 1382 // @STATEMACHINE(l2cap) 1383 switch (channel->state) { 1384 1385 case L2CAP_STATE_WAIT_CONNECT_RSP: 1386 switch (code){ 1387 case CONNECTION_RESPONSE: 1388 l2cap_stop_rtx(channel); 1389 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1390 switch (result) { 1391 case 0: 1392 // successful connection 1393 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1394 channel->state = L2CAP_STATE_CONFIG; 1395 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1396 break; 1397 case 1: 1398 // connection pending. get some coffee, but start the ERTX 1399 l2cap_start_ertx(channel); 1400 break; 1401 default: 1402 // channel closed 1403 channel->state = L2CAP_STATE_CLOSED; 1404 // map l2cap connection response result to BTstack status enumeration 1405 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1406 1407 // drop link key if security block 1408 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1409 gap_drop_link_key_for_bd_addr(channel->address); 1410 } 1411 1412 // discard channel 1413 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1414 btstack_memory_l2cap_channel_free(channel); 1415 break; 1416 } 1417 break; 1418 1419 default: 1420 //@TODO: implement other signaling packets 1421 break; 1422 } 1423 break; 1424 1425 case L2CAP_STATE_CONFIG: 1426 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1427 switch (code) { 1428 case CONFIGURE_REQUEST: 1429 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1430 l2cap_signaling_handle_configure_request(channel, command); 1431 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1432 // only done if continuation not set 1433 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1434 } 1435 break; 1436 case CONFIGURE_RESPONSE: 1437 l2cap_stop_rtx(channel); 1438 switch (result){ 1439 case 0: // success 1440 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1441 break; 1442 case 4: // pending 1443 l2cap_start_ertx(channel); 1444 break; 1445 default: 1446 // retry on negative result 1447 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1448 break; 1449 } 1450 break; 1451 default: 1452 break; 1453 } 1454 if (l2cap_channel_ready_for_open(channel)){ 1455 // for open: 1456 channel->state = L2CAP_STATE_OPEN; 1457 l2cap_emit_channel_opened(channel, 0); 1458 } 1459 break; 1460 1461 case L2CAP_STATE_WAIT_DISCONNECT: 1462 switch (code) { 1463 case DISCONNECTION_RESPONSE: 1464 l2cap_finialize_channel_close(channel); 1465 break; 1466 default: 1467 //@TODO: implement other signaling packets 1468 break; 1469 } 1470 break; 1471 1472 case L2CAP_STATE_CLOSED: 1473 // @TODO handle incoming requests 1474 break; 1475 1476 case L2CAP_STATE_OPEN: 1477 //@TODO: implement other signaling packets, e.g. re-configure 1478 break; 1479 default: 1480 break; 1481 } 1482 // log_info("new state %u", channel->state); 1483 } 1484 1485 1486 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1487 1488 // get code, signalind identifier and command len 1489 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1490 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1491 1492 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1493 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1494 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1495 return; 1496 } 1497 1498 // general commands without an assigned channel 1499 switch(code) { 1500 1501 case CONNECTION_REQUEST: { 1502 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1503 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1504 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1505 return; 1506 } 1507 1508 case ECHO_REQUEST: 1509 l2cap_register_signaling_response(handle, code, sig_id, 0); 1510 return; 1511 1512 case INFORMATION_REQUEST: { 1513 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1514 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1515 return; 1516 } 1517 1518 default: 1519 break; 1520 } 1521 1522 1523 // Get potential destination CID 1524 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1525 1526 // Find channel for this sig_id and connection handle 1527 btstack_linked_list_iterator_t it; 1528 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1529 while (btstack_linked_list_iterator_has_next(&it)){ 1530 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1531 if (channel->con_handle != handle) continue; 1532 if (code & 1) { 1533 // match odd commands (responses) by previous signaling identifier 1534 if (channel->local_sig_id == sig_id) { 1535 l2cap_signaling_handler_channel(channel, command); 1536 break; 1537 } 1538 } else { 1539 // match even commands (requests) by local channel id 1540 if (channel->local_cid == dest_cid) { 1541 l2cap_signaling_handler_channel(channel, command); 1542 break; 1543 } 1544 } 1545 } 1546 } 1547 #endif 1548 1549 #ifdef ENABLE_BLE 1550 1551 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 1552 uint8_t event[6]; 1553 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 1554 event[1] = 4; 1555 little_endian_store_16(event, 2, con_handle); 1556 little_endian_store_16(event, 4, result); 1557 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1558 if (!l2cap_event_packet_handler) return; 1559 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 1560 } 1561 1562 // @returns valid 1563 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 1564 hci_connection_t * connection; 1565 uint16_t result; 1566 uint8_t event[10]; 1567 1568 #ifdef ENABLE_LE_DATA_CHANNELS 1569 btstack_linked_list_iterator_t it; 1570 l2cap_channel_t * channel; 1571 uint16_t local_cid; 1572 uint16_t le_psm; 1573 uint16_t new_credits; 1574 uint16_t credits_before; 1575 l2cap_service_t * service; 1576 #endif 1577 1578 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1579 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 1580 1581 switch (code){ 1582 1583 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 1584 result = little_endian_read_16(command, 4); 1585 l2cap_emit_connection_parameter_update_response(handle, result); 1586 break; 1587 1588 case CONNECTION_PARAMETER_UPDATE_REQUEST: 1589 connection = hci_connection_for_handle(handle); 1590 if (connection){ 1591 if (connection->role != HCI_ROLE_MASTER){ 1592 // reject command without notifying upper layer when not in master role 1593 return 0; 1594 } 1595 int update_parameter = 1; 1596 le_connection_parameter_range_t existing_range; 1597 gap_get_connection_parameter_range(&existing_range); 1598 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 1599 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 1600 uint16_t le_conn_latency = little_endian_read_16(command,12); 1601 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 1602 1603 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1604 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1605 1606 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1607 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1608 1609 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1610 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1611 1612 if (update_parameter){ 1613 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1614 connection->le_conn_interval_min = le_conn_interval_min; 1615 connection->le_conn_interval_max = le_conn_interval_max; 1616 connection->le_conn_latency = le_conn_latency; 1617 connection->le_supervision_timeout = le_supervision_timeout; 1618 } else { 1619 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1620 } 1621 connection->le_con_param_update_identifier = sig_id; 1622 } 1623 1624 if (!l2cap_event_packet_handler) break; 1625 1626 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1627 event[1] = 8; 1628 memcpy(&event[2], &command[4], 8); 1629 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1630 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1631 break; 1632 1633 #ifdef ENABLE_LE_DATA_CHANNELS 1634 1635 case COMMAND_REJECT: 1636 // Find channel for this sig_id and connection handle 1637 channel = NULL; 1638 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1639 while (btstack_linked_list_iterator_has_next(&it)){ 1640 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1641 if (a_channel->con_handle != handle) continue; 1642 if (a_channel->local_sig_id != sig_id) continue; 1643 channel = a_channel; 1644 break; 1645 } 1646 if (!channel) break; 1647 1648 // if received while waiting for le connection response, assume legacy device 1649 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 1650 channel->state = L2CAP_STATE_CLOSED; 1651 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 1652 l2cap_emit_le_channel_opened(channel, 0x0002); 1653 1654 // discard channel 1655 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1656 btstack_memory_l2cap_channel_free(channel); 1657 break; 1658 } 1659 break; 1660 1661 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1662 1663 // get hci connection, bail if not found (must not happen) 1664 connection = hci_connection_for_handle(handle); 1665 if (!connection) return 0; 1666 1667 // check if service registered 1668 le_psm = little_endian_read_16(command, 4); 1669 service = l2cap_le_get_service(le_psm); 1670 1671 if (service){ 1672 1673 uint16_t source_cid = little_endian_read_16(command, 6); 1674 if (source_cid < 0x40){ 1675 // 0x0009 Connection refused - Invalid Source CID 1676 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0009); 1677 return 1; 1678 } 1679 1680 // go through list of channels for this ACL connection and check if we get a match 1681 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1682 while (btstack_linked_list_iterator_has_next(&it)){ 1683 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1684 if (a_channel->con_handle != handle) continue; 1685 if (a_channel->remote_cid != source_cid) continue; 1686 // 0x000a Connection refused - Source CID already allocated 1687 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x000a); 1688 return 1; 1689 } 1690 1691 // security: check encryption 1692 if (service->required_security_level >= LEVEL_2){ 1693 if (sm_encryption_key_size(handle) == 0){ 1694 // 0x0008 Connection refused - insufficient encryption 1695 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0008); 1696 return 1; 1697 } 1698 // anything less than 16 byte key size is insufficient 1699 if (sm_encryption_key_size(handle) < 16){ 1700 // 0x0007 Connection refused – insufficient encryption key size 1701 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0007); 1702 return 1; 1703 } 1704 } 1705 1706 // security: check authencation 1707 if (service->required_security_level >= LEVEL_3){ 1708 if (!sm_authenticated(handle)){ 1709 // 0x0005 Connection refused – insufficient authentication 1710 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0005); 1711 return 1; 1712 } 1713 } 1714 1715 // security: check authorization 1716 if (service->required_security_level >= LEVEL_4){ 1717 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 1718 // 0x0006 Connection refused – insufficient authorization 1719 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0006); 1720 return 1; 1721 } 1722 } 1723 1724 // allocate channel 1725 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 1726 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 1727 if (!channel){ 1728 // 0x0004 Connection refused – no resources available 1729 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0004); 1730 return 1; 1731 } 1732 1733 channel->con_handle = handle; 1734 channel->remote_cid = source_cid; 1735 channel->remote_sig_id = sig_id; 1736 channel->remote_mtu = little_endian_read_16(command, 8); 1737 channel->remote_mps = little_endian_read_16(command, 10); 1738 channel->credits_outgoing = little_endian_read_16(command, 12); 1739 1740 // set initial state 1741 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1742 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 1743 1744 // add to connections list 1745 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1746 1747 // post connection request event 1748 l2cap_emit_le_incoming_connection(channel); 1749 1750 } else { 1751 // Connection refused – LE_PSM not supported 1752 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0002); 1753 } 1754 break; 1755 1756 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 1757 // Find channel for this sig_id and connection handle 1758 channel = NULL; 1759 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1760 while (btstack_linked_list_iterator_has_next(&it)){ 1761 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1762 if (a_channel->con_handle != handle) continue; 1763 if (a_channel->local_sig_id != sig_id) continue; 1764 channel = a_channel; 1765 break; 1766 } 1767 if (!channel) break; 1768 1769 // cid + 0 1770 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 1771 if (result){ 1772 channel->state = L2CAP_STATE_CLOSED; 1773 // map l2cap connection response result to BTstack status enumeration 1774 l2cap_emit_le_channel_opened(channel, result); 1775 1776 // discard channel 1777 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1778 btstack_memory_l2cap_channel_free(channel); 1779 break; 1780 } 1781 1782 // success 1783 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1784 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1785 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 1786 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 1787 channel->state = L2CAP_STATE_OPEN; 1788 l2cap_emit_le_channel_opened(channel, result); 1789 break; 1790 1791 case LE_FLOW_CONTROL_CREDIT: 1792 // find channel 1793 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1794 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1795 if (!channel) { 1796 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1797 break; 1798 } 1799 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1800 credits_before = channel->credits_outgoing; 1801 channel->credits_outgoing += new_credits; 1802 // check for credit overrun 1803 if (credits_before > channel->credits_outgoing){ 1804 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 1805 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1806 break; 1807 } 1808 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 1809 break; 1810 1811 case DISCONNECTION_REQUEST: 1812 // find channel 1813 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1814 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1815 if (!channel) { 1816 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1817 break; 1818 } 1819 channel->remote_sig_id = sig_id; 1820 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1821 break; 1822 1823 #endif 1824 1825 case DISCONNECTION_RESPONSE: 1826 break; 1827 1828 default: 1829 // command unknown -> reject command 1830 return 0; 1831 } 1832 return 1; 1833 } 1834 #endif 1835 1836 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 1837 1838 l2cap_channel_t * l2cap_channel; 1839 (void) l2cap_channel; 1840 1841 // Get Channel ID 1842 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1843 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1844 1845 switch (channel_id) { 1846 1847 #ifdef ENABLE_CLASSIC 1848 case L2CAP_CID_SIGNALING: { 1849 uint16_t command_offset = 8; 1850 while (command_offset < size) { 1851 // handle signaling commands 1852 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1853 1854 // increment command_offset 1855 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1856 } 1857 break; 1858 } 1859 #endif 1860 1861 #ifdef ENABLE_BLE 1862 case L2CAP_CID_SIGNALING_LE: { 1863 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1864 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 1865 if (!valid){ 1866 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1867 } 1868 break; 1869 } 1870 #endif 1871 1872 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1873 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 1874 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1875 } 1876 break; 1877 1878 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1879 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 1880 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1881 } 1882 break; 1883 1884 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 1885 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 1886 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1887 } 1888 break; 1889 1890 default: 1891 #ifdef ENABLE_CLASSIC 1892 // Find channel for this channel_id and connection handle 1893 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 1894 if (l2cap_channel) { 1895 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1896 } 1897 #endif 1898 #ifdef ENABLE_LE_DATA_CHANNELS 1899 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 1900 if (l2cap_channel) { 1901 // credit counting 1902 if (l2cap_channel->credits_incoming == 0){ 1903 log_error("LE Data Channel packet received but no incoming credits"); 1904 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1905 break; 1906 } 1907 l2cap_channel->credits_incoming--; 1908 1909 // automatic credits 1910 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 1911 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 1912 } 1913 1914 // first fragment 1915 uint16_t pos = 0; 1916 if (!l2cap_channel->receive_sdu_len){ 1917 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 1918 l2cap_channel->receive_sdu_pos = 0; 1919 pos += 2; 1920 size -= 2; 1921 } 1922 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 1923 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 1924 // done? 1925 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 1926 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 1927 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 1928 l2cap_channel->receive_sdu_len = 0; 1929 } 1930 } else { 1931 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 1932 } 1933 #endif 1934 break; 1935 } 1936 1937 l2cap_run(); 1938 } 1939 1940 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1941 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 1942 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 1943 if (index < 0) return; 1944 fixed_channels[index].callback = the_packet_handler; 1945 } 1946 1947 #ifdef ENABLE_CLASSIC 1948 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1949 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 1950 channel->state = L2CAP_STATE_CLOSED; 1951 l2cap_emit_channel_closed(channel); 1952 // discard channel 1953 l2cap_stop_rtx(channel); 1954 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1955 btstack_memory_l2cap_channel_free(channel); 1956 } 1957 1958 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 1959 btstack_linked_list_iterator_t it; 1960 btstack_linked_list_iterator_init(&it, services); 1961 while (btstack_linked_list_iterator_has_next(&it)){ 1962 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 1963 if ( service->psm == psm){ 1964 return service; 1965 }; 1966 } 1967 return NULL; 1968 } 1969 1970 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 1971 return l2cap_get_service_internal(&l2cap_services, psm); 1972 } 1973 1974 1975 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 1976 1977 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1978 1979 // check for alread registered psm 1980 l2cap_service_t *service = l2cap_get_service(psm); 1981 if (service) { 1982 log_error("l2cap_register_service: PSM %u already registered", psm); 1983 return L2CAP_SERVICE_ALREADY_REGISTERED; 1984 } 1985 1986 // alloc structure 1987 service = btstack_memory_l2cap_service_get(); 1988 if (!service) { 1989 log_error("l2cap_register_service: no memory for l2cap_service_t"); 1990 return BTSTACK_MEMORY_ALLOC_FAILED; 1991 } 1992 1993 // fill in 1994 service->psm = psm; 1995 service->mtu = mtu; 1996 service->packet_handler = service_packet_handler; 1997 service->required_security_level = security_level; 1998 1999 // add to services list 2000 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 2001 2002 // enable page scan 2003 gap_connectable_control(1); 2004 2005 return 0; 2006 } 2007 2008 uint8_t l2cap_unregister_service(uint16_t psm){ 2009 2010 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 2011 2012 l2cap_service_t *service = l2cap_get_service(psm); 2013 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2014 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 2015 btstack_memory_l2cap_service_free(service); 2016 2017 // disable page scan when no services registered 2018 if (btstack_linked_list_empty(&l2cap_services)) { 2019 gap_connectable_control(0); 2020 } 2021 return 0; 2022 } 2023 #endif 2024 2025 2026 #ifdef ENABLE_LE_DATA_CHANNELS 2027 2028 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 2029 if (!channel->waiting_for_can_send_now) return; 2030 if (channel->send_sdu_buffer) return; 2031 channel->waiting_for_can_send_now = 0; 2032 log_info("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 2033 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 2034 } 2035 2036 // 1BH2222 2037 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 2038 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", 2039 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 2040 uint8_t event[19]; 2041 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 2042 event[1] = sizeof(event) - 2; 2043 event[2] = channel->address_type; 2044 reverse_bd_addr(channel->address, &event[3]); 2045 little_endian_store_16(event, 9, channel->con_handle); 2046 little_endian_store_16(event, 11, channel->psm); 2047 little_endian_store_16(event, 13, channel->local_cid); 2048 little_endian_store_16(event, 15, channel->remote_cid); 2049 little_endian_store_16(event, 17, channel->remote_mtu); 2050 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2051 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2052 } 2053 // 11BH22222 2054 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 2055 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", 2056 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 2057 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 2058 uint8_t event[23]; 2059 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 2060 event[1] = sizeof(event) - 2; 2061 event[2] = status; 2062 event[3] = channel->address_type; 2063 reverse_bd_addr(channel->address, &event[4]); 2064 little_endian_store_16(event, 10, channel->con_handle); 2065 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 2066 little_endian_store_16(event, 13, channel->psm); 2067 little_endian_store_16(event, 15, channel->local_cid); 2068 little_endian_store_16(event, 17, channel->remote_cid); 2069 little_endian_store_16(event, 19, channel->local_mtu); 2070 little_endian_store_16(event, 21, channel->remote_mtu); 2071 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2072 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2073 } 2074 2075 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 2076 btstack_linked_list_iterator_t it; 2077 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2078 while (btstack_linked_list_iterator_has_next(&it)){ 2079 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2080 if ( channel->local_cid == local_cid) { 2081 return channel; 2082 } 2083 } 2084 return NULL; 2085 } 2086 2087 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2088 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 2089 channel->state = L2CAP_STATE_CLOSED; 2090 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 2091 // discard channel 2092 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2093 btstack_memory_l2cap_channel_free(channel); 2094 } 2095 2096 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 2097 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 2098 } 2099 2100 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 2101 2102 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 2103 2104 // check for alread registered psm 2105 l2cap_service_t *service = l2cap_le_get_service(psm); 2106 if (service) { 2107 return L2CAP_SERVICE_ALREADY_REGISTERED; 2108 } 2109 2110 // alloc structure 2111 service = btstack_memory_l2cap_service_get(); 2112 if (!service) { 2113 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 2114 return BTSTACK_MEMORY_ALLOC_FAILED; 2115 } 2116 2117 // fill in 2118 service->psm = psm; 2119 service->mtu = 0; 2120 service->packet_handler = packet_handler; 2121 service->required_security_level = security_level; 2122 2123 // add to services list 2124 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 2125 2126 // done 2127 return 0; 2128 } 2129 2130 uint8_t l2cap_le_unregister_service(uint16_t psm) { 2131 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 2132 l2cap_service_t *service = l2cap_le_get_service(psm); 2133 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2134 2135 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 2136 btstack_memory_l2cap_service_free(service); 2137 return 0; 2138 } 2139 2140 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 2141 // get channel 2142 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2143 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2144 2145 // validate state 2146 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2147 return ERROR_CODE_COMMAND_DISALLOWED; 2148 } 2149 2150 // set state accept connection 2151 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 2152 channel->receive_sdu_buffer = receive_sdu_buffer; 2153 channel->local_mtu = mtu; 2154 channel->new_credits_incoming = initial_credits; 2155 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2156 2157 // test 2158 // channel->new_credits_incoming = 1; 2159 2160 // go 2161 l2cap_run(); 2162 return 0; 2163 } 2164 2165 /** 2166 * @brief Deny incoming LE Data Channel connection due to resource constraints 2167 * @param local_cid L2CAP LE Data Channel Identifier 2168 */ 2169 2170 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 2171 // get channel 2172 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2173 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2174 2175 // validate state 2176 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2177 return ERROR_CODE_COMMAND_DISALLOWED; 2178 } 2179 2180 // set state decline connection 2181 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 2182 channel->reason = 0x04; // no resources available 2183 l2cap_run(); 2184 return 0; 2185 } 2186 2187 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 2188 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 2189 uint16_t * out_local_cid) { 2190 2191 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 2192 2193 2194 hci_connection_t * connection = hci_connection_for_handle(con_handle); 2195 if (!connection) { 2196 log_error("no hci_connection for handle 0x%04x", con_handle); 2197 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 2198 } 2199 2200 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 2201 if (!channel) { 2202 return BTSTACK_MEMORY_ALLOC_FAILED; 2203 } 2204 log_info("l2cap_le_create_channel %p", channel); 2205 2206 // store local_cid 2207 if (out_local_cid){ 2208 *out_local_cid = channel->local_cid; 2209 } 2210 2211 // provide buffer 2212 channel->con_handle = con_handle; 2213 channel->receive_sdu_buffer = receive_sdu_buffer; 2214 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 2215 channel->new_credits_incoming = initial_credits; 2216 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2217 2218 // add to connections list 2219 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2220 2221 // go 2222 l2cap_run(); 2223 return 0; 2224 } 2225 2226 /** 2227 * @brief Provide credtis for LE Data Channel 2228 * @param local_cid L2CAP LE Data Channel Identifier 2229 * @param credits Number additional credits for peer 2230 */ 2231 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2232 2233 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2234 if (!channel) { 2235 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2236 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2237 } 2238 2239 // check state 2240 if (channel->state != L2CAP_STATE_OPEN){ 2241 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 2242 } 2243 2244 // assert incoming credits + credits <= 0xffff 2245 uint32_t total_credits = channel->credits_incoming; 2246 total_credits += channel->new_credits_incoming; 2247 total_credits += credits; 2248 if (total_credits > 0xffff){ 2249 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 2250 channel->new_credits_incoming, credits); 2251 } 2252 2253 // set credits_granted 2254 channel->new_credits_incoming += credits; 2255 2256 // go 2257 l2cap_run(); 2258 return 0; 2259 } 2260 2261 /** 2262 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2263 * @param local_cid L2CAP LE Data Channel Identifier 2264 */ 2265 int l2cap_le_can_send_now(uint16_t local_cid){ 2266 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2267 if (!channel) { 2268 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2269 return 0; 2270 } 2271 2272 // check state 2273 if (channel->state != L2CAP_STATE_OPEN) return 0; 2274 2275 // check queue 2276 if (channel->send_sdu_buffer) return 0; 2277 2278 // fine, go ahead 2279 return 1; 2280 } 2281 2282 /** 2283 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2284 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2285 * so packet handler should be ready to handle it 2286 * @param local_cid L2CAP LE Data Channel Identifier 2287 */ 2288 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2289 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2290 if (!channel) { 2291 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 2292 return 0; 2293 } 2294 channel->waiting_for_can_send_now = 1; 2295 l2cap_le_notify_channel_can_send(channel); 2296 return 0; 2297 } 2298 2299 /** 2300 * @brief Send data via LE Data Channel 2301 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2302 * @param local_cid L2CAP LE Data Channel Identifier 2303 * @param data data to send 2304 * @param size data size 2305 */ 2306 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2307 2308 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2309 if (!channel) { 2310 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2311 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2312 } 2313 2314 if (len > channel->remote_mtu){ 2315 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2316 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2317 } 2318 2319 if (channel->send_sdu_buffer){ 2320 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2321 return BTSTACK_ACL_BUFFERS_FULL; 2322 } 2323 2324 channel->send_sdu_buffer = data; 2325 channel->send_sdu_len = len; 2326 channel->send_sdu_pos = 0; 2327 2328 l2cap_run(); 2329 return 0; 2330 } 2331 2332 /** 2333 * @brief Disconnect from LE Data Channel 2334 * @param local_cid L2CAP LE Data Channel Identifier 2335 */ 2336 uint8_t l2cap_le_disconnect(uint16_t local_cid) 2337 { 2338 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2339 if (!channel) { 2340 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2341 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2342 } 2343 2344 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2345 l2cap_run(); 2346 return 0; 2347 } 2348 2349 #endif 2350