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 = 0; 1053 if (l2cap_fixed_channel_table_index_is_le(i)){ 1054 #ifdef ENABLE_BLE 1055 can_send = hci_can_send_acl_le_packet_now(); 1056 #endif 1057 } else { 1058 #ifdef ENABLE_CLASSIC 1059 can_send = hci_can_send_acl_classic_packet_now(); 1060 #endif 1061 } 1062 if (!can_send) continue; 1063 fixed_channels[i].waiting_for_can_send_now = 0; 1064 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1065 } 1066 } 1067 1068 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1069 1070 bd_addr_t address; 1071 hci_con_handle_t handle; 1072 int hci_con_used; 1073 btstack_linked_list_iterator_t it; 1074 1075 // avoid unused warnings 1076 (void) address; 1077 (void) hci_con_used; 1078 (void) it; 1079 1080 switch(hci_event_packet_get_type(packet)){ 1081 1082 // Notify channel packet handler if they can send now 1083 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1084 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1085 l2cap_run(); // try sending signaling packets first 1086 l2cap_notify_channel_can_send(); 1087 break; 1088 1089 case HCI_EVENT_COMMAND_STATUS: 1090 l2cap_run(); // try sending signaling packets first 1091 break; 1092 1093 #ifdef ENABLE_CLASSIC 1094 // handle connection complete events 1095 case HCI_EVENT_CONNECTION_COMPLETE: 1096 reverse_bd_addr(&packet[5], address); 1097 if (packet[2] == 0){ 1098 handle = little_endian_read_16(packet, 3); 1099 l2cap_handle_connection_success_for_addr(address, handle); 1100 } else { 1101 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1102 } 1103 break; 1104 1105 // handle successful create connection cancel command 1106 case HCI_EVENT_COMMAND_COMPLETE: 1107 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1108 if (packet[5] == 0){ 1109 reverse_bd_addr(&packet[6], address); 1110 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1111 l2cap_handle_connection_failed_for_addr(address, 0x16); 1112 } 1113 } 1114 l2cap_run(); // try sending signaling packets first 1115 break; 1116 #endif 1117 1118 // handle disconnection complete events 1119 case HCI_EVENT_DISCONNECTION_COMPLETE: 1120 // send l2cap disconnect events for all channels on this handle and free them 1121 handle = little_endian_read_16(packet, 3); 1122 #ifdef ENABLE_CLASSIC 1123 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1124 while (btstack_linked_list_iterator_has_next(&it)){ 1125 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1126 if (channel->con_handle != handle) continue; 1127 l2cap_emit_channel_closed(channel); 1128 l2cap_stop_rtx(channel); 1129 btstack_linked_list_iterator_remove(&it); 1130 btstack_memory_l2cap_channel_free(channel); 1131 } 1132 #endif 1133 #ifdef ENABLE_LE_DATA_CHANNELS 1134 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1135 while (btstack_linked_list_iterator_has_next(&it)){ 1136 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1137 if (channel->con_handle != handle) continue; 1138 l2cap_emit_channel_closed(channel); 1139 btstack_linked_list_iterator_remove(&it); 1140 btstack_memory_l2cap_channel_free(channel); 1141 } 1142 #endif 1143 break; 1144 1145 // HCI Connection Timeouts 1146 #ifdef ENABLE_CLASSIC 1147 case L2CAP_EVENT_TIMEOUT_CHECK: 1148 handle = little_endian_read_16(packet, 2); 1149 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1150 if (hci_authentication_active_for_handle(handle)) break; 1151 hci_con_used = 0; 1152 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1153 while (btstack_linked_list_iterator_has_next(&it)){ 1154 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1155 if (channel->con_handle != handle) continue; 1156 hci_con_used = 1; 1157 break; 1158 } 1159 if (hci_con_used) break; 1160 if (!hci_can_send_command_packet_now()) break; 1161 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1162 break; 1163 1164 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1165 handle = little_endian_read_16(packet, 3); 1166 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1167 while (btstack_linked_list_iterator_has_next(&it)){ 1168 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1169 if (channel->con_handle != handle) continue; 1170 l2cap_handle_remote_supported_features_received(channel); 1171 break; 1172 } 1173 break; 1174 1175 case GAP_EVENT_SECURITY_LEVEL: 1176 handle = little_endian_read_16(packet, 2); 1177 log_info("l2cap - security level update"); 1178 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1179 while (btstack_linked_list_iterator_has_next(&it)){ 1180 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1181 if (channel->con_handle != handle) continue; 1182 1183 log_info("l2cap - state %u", channel->state); 1184 1185 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1186 gap_security_level_t required_level = channel->required_security_level; 1187 1188 switch (channel->state){ 1189 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1190 if (actual_level >= required_level){ 1191 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1192 l2cap_emit_incoming_connection(channel); 1193 } else { 1194 channel->reason = 0x0003; // security block 1195 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1196 } 1197 break; 1198 1199 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1200 if (actual_level >= required_level){ 1201 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1202 } else { 1203 // disconnnect, authentication not good enough 1204 hci_disconnect_security_block(handle); 1205 } 1206 break; 1207 1208 default: 1209 break; 1210 } 1211 } 1212 break; 1213 #endif 1214 1215 default: 1216 break; 1217 } 1218 1219 l2cap_run(); 1220 } 1221 1222 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 1223 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1224 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1225 signaling_responses[signaling_responses_pending].handle = handle; 1226 signaling_responses[signaling_responses_pending].code = code; 1227 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1228 signaling_responses[signaling_responses_pending].data = data; 1229 signaling_responses_pending++; 1230 l2cap_run(); 1231 } 1232 } 1233 1234 #ifdef ENABLE_CLASSIC 1235 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1236 channel->remote_sig_id = identifier; 1237 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1238 l2cap_run(); 1239 } 1240 1241 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1242 1243 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1244 l2cap_service_t *service = l2cap_get_service(psm); 1245 if (!service) { 1246 // 0x0002 PSM not supported 1247 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 1248 return; 1249 } 1250 1251 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1252 if (!hci_connection) { 1253 // 1254 log_error("no hci_connection for handle %u", handle); 1255 return; 1256 } 1257 1258 // alloc structure 1259 // log_info("l2cap_handle_connection_request register channel"); 1260 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1261 psm, service->mtu, service->required_security_level); 1262 if (!channel){ 1263 // 0x0004 No resources available 1264 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 1265 return; 1266 } 1267 1268 channel->con_handle = handle; 1269 channel->remote_cid = source_cid; 1270 channel->remote_sig_id = sig_id; 1271 1272 // limit local mtu to max acl packet length - l2cap header 1273 if (channel->local_mtu > l2cap_max_mtu()) { 1274 channel->local_mtu = l2cap_max_mtu(); 1275 } 1276 1277 // set initial state 1278 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1279 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1280 1281 // add to connections list 1282 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1283 1284 // assert security requirements 1285 gap_request_security_level(handle, channel->required_security_level); 1286 } 1287 1288 void l2cap_accept_connection(uint16_t local_cid){ 1289 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1290 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1291 if (!channel) { 1292 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1293 return; 1294 } 1295 1296 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1297 1298 // process 1299 l2cap_run(); 1300 } 1301 1302 void l2cap_decline_connection(uint16_t local_cid){ 1303 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1304 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1305 if (!channel) { 1306 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1307 return; 1308 } 1309 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1310 channel->reason = 0x04; // no resources available 1311 l2cap_run(); 1312 } 1313 1314 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1315 1316 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1317 1318 uint16_t flags = little_endian_read_16(command, 6); 1319 if (flags & 1) { 1320 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1321 } 1322 1323 // accept the other's configuration options 1324 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1325 uint16_t pos = 8; 1326 while (pos < end_pos){ 1327 uint8_t option_hint = command[pos] >> 7; 1328 uint8_t option_type = command[pos] & 0x7f; 1329 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1330 pos++; 1331 uint8_t length = command[pos++]; 1332 // MTU { type(8): 1, len(8):2, MTU(16) } 1333 if (option_type == 1 && length == 2){ 1334 channel->remote_mtu = little_endian_read_16(command, pos); 1335 // log_info("l2cap cid 0x%02x, remote mtu %u", channel->local_cid, channel->remote_mtu); 1336 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1337 } 1338 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1339 if (option_type == 2 && length == 2){ 1340 channel->flush_timeout = little_endian_read_16(command, pos); 1341 } 1342 // check for unknown options 1343 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1344 log_info("l2cap cid %u, unknown options", channel->local_cid); 1345 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1346 } 1347 pos += length; 1348 } 1349 } 1350 1351 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1352 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1353 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1354 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1355 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1356 if (channel->state == L2CAP_STATE_OPEN) return 0; 1357 return 1; 1358 } 1359 1360 1361 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1362 1363 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1364 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1365 uint16_t result = 0; 1366 1367 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1368 1369 // handle DISCONNECT REQUESTS seperately 1370 if (code == DISCONNECTION_REQUEST){ 1371 switch (channel->state){ 1372 case L2CAP_STATE_CONFIG: 1373 case L2CAP_STATE_OPEN: 1374 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1375 case L2CAP_STATE_WAIT_DISCONNECT: 1376 l2cap_handle_disconnect_request(channel, identifier); 1377 break; 1378 1379 default: 1380 // ignore in other states 1381 break; 1382 } 1383 return; 1384 } 1385 1386 // @STATEMACHINE(l2cap) 1387 switch (channel->state) { 1388 1389 case L2CAP_STATE_WAIT_CONNECT_RSP: 1390 switch (code){ 1391 case CONNECTION_RESPONSE: 1392 l2cap_stop_rtx(channel); 1393 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1394 switch (result) { 1395 case 0: 1396 // successful connection 1397 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1398 channel->state = L2CAP_STATE_CONFIG; 1399 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1400 break; 1401 case 1: 1402 // connection pending. get some coffee, but start the ERTX 1403 l2cap_start_ertx(channel); 1404 break; 1405 default: 1406 // channel closed 1407 channel->state = L2CAP_STATE_CLOSED; 1408 // map l2cap connection response result to BTstack status enumeration 1409 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1410 1411 // drop link key if security block 1412 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1413 gap_drop_link_key_for_bd_addr(channel->address); 1414 } 1415 1416 // discard channel 1417 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1418 btstack_memory_l2cap_channel_free(channel); 1419 break; 1420 } 1421 break; 1422 1423 default: 1424 //@TODO: implement other signaling packets 1425 break; 1426 } 1427 break; 1428 1429 case L2CAP_STATE_CONFIG: 1430 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1431 switch (code) { 1432 case CONFIGURE_REQUEST: 1433 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1434 l2cap_signaling_handle_configure_request(channel, command); 1435 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1436 // only done if continuation not set 1437 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1438 } 1439 break; 1440 case CONFIGURE_RESPONSE: 1441 l2cap_stop_rtx(channel); 1442 switch (result){ 1443 case 0: // success 1444 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1445 break; 1446 case 4: // pending 1447 l2cap_start_ertx(channel); 1448 break; 1449 default: 1450 // retry on negative result 1451 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1452 break; 1453 } 1454 break; 1455 default: 1456 break; 1457 } 1458 if (l2cap_channel_ready_for_open(channel)){ 1459 // for open: 1460 channel->state = L2CAP_STATE_OPEN; 1461 l2cap_emit_channel_opened(channel, 0); 1462 } 1463 break; 1464 1465 case L2CAP_STATE_WAIT_DISCONNECT: 1466 switch (code) { 1467 case DISCONNECTION_RESPONSE: 1468 l2cap_finialize_channel_close(channel); 1469 break; 1470 default: 1471 //@TODO: implement other signaling packets 1472 break; 1473 } 1474 break; 1475 1476 case L2CAP_STATE_CLOSED: 1477 // @TODO handle incoming requests 1478 break; 1479 1480 case L2CAP_STATE_OPEN: 1481 //@TODO: implement other signaling packets, e.g. re-configure 1482 break; 1483 default: 1484 break; 1485 } 1486 // log_info("new state %u", channel->state); 1487 } 1488 1489 1490 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1491 1492 // get code, signalind identifier and command len 1493 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1494 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1495 1496 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1497 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1498 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1499 return; 1500 } 1501 1502 // general commands without an assigned channel 1503 switch(code) { 1504 1505 case CONNECTION_REQUEST: { 1506 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1507 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1508 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1509 return; 1510 } 1511 1512 case ECHO_REQUEST: 1513 l2cap_register_signaling_response(handle, code, sig_id, 0); 1514 return; 1515 1516 case INFORMATION_REQUEST: { 1517 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1518 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1519 return; 1520 } 1521 1522 default: 1523 break; 1524 } 1525 1526 1527 // Get potential destination CID 1528 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1529 1530 // Find channel for this sig_id and connection handle 1531 btstack_linked_list_iterator_t it; 1532 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1533 while (btstack_linked_list_iterator_has_next(&it)){ 1534 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1535 if (channel->con_handle != handle) continue; 1536 if (code & 1) { 1537 // match odd commands (responses) by previous signaling identifier 1538 if (channel->local_sig_id == sig_id) { 1539 l2cap_signaling_handler_channel(channel, command); 1540 break; 1541 } 1542 } else { 1543 // match even commands (requests) by local channel id 1544 if (channel->local_cid == dest_cid) { 1545 l2cap_signaling_handler_channel(channel, command); 1546 break; 1547 } 1548 } 1549 } 1550 } 1551 #endif 1552 1553 #ifdef ENABLE_BLE 1554 1555 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 1556 uint8_t event[6]; 1557 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 1558 event[1] = 4; 1559 little_endian_store_16(event, 2, con_handle); 1560 little_endian_store_16(event, 4, result); 1561 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1562 if (!l2cap_event_packet_handler) return; 1563 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 1564 } 1565 1566 // @returns valid 1567 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 1568 hci_connection_t * connection; 1569 uint16_t result; 1570 uint8_t event[10]; 1571 1572 #ifdef ENABLE_LE_DATA_CHANNELS 1573 btstack_linked_list_iterator_t it; 1574 l2cap_channel_t * channel; 1575 uint16_t local_cid; 1576 uint16_t le_psm; 1577 uint16_t new_credits; 1578 uint16_t credits_before; 1579 l2cap_service_t * service; 1580 #endif 1581 1582 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1583 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 1584 1585 switch (code){ 1586 1587 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 1588 result = little_endian_read_16(command, 4); 1589 l2cap_emit_connection_parameter_update_response(handle, result); 1590 break; 1591 1592 case CONNECTION_PARAMETER_UPDATE_REQUEST: 1593 connection = hci_connection_for_handle(handle); 1594 if (connection){ 1595 if (connection->role != HCI_ROLE_MASTER){ 1596 // reject command without notifying upper layer when not in master role 1597 return 0; 1598 } 1599 int update_parameter = 1; 1600 le_connection_parameter_range_t existing_range; 1601 gap_get_connection_parameter_range(&existing_range); 1602 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 1603 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 1604 uint16_t le_conn_latency = little_endian_read_16(command,12); 1605 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 1606 1607 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1608 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1609 1610 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1611 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1612 1613 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1614 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1615 1616 if (update_parameter){ 1617 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1618 connection->le_conn_interval_min = le_conn_interval_min; 1619 connection->le_conn_interval_max = le_conn_interval_max; 1620 connection->le_conn_latency = le_conn_latency; 1621 connection->le_supervision_timeout = le_supervision_timeout; 1622 } else { 1623 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1624 } 1625 connection->le_con_param_update_identifier = sig_id; 1626 } 1627 1628 if (!l2cap_event_packet_handler) break; 1629 1630 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1631 event[1] = 8; 1632 memcpy(&event[2], &command[4], 8); 1633 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1634 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1635 break; 1636 1637 #ifdef ENABLE_LE_DATA_CHANNELS 1638 1639 case COMMAND_REJECT: 1640 // Find channel for this sig_id and connection handle 1641 channel = NULL; 1642 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1643 while (btstack_linked_list_iterator_has_next(&it)){ 1644 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1645 if (a_channel->con_handle != handle) continue; 1646 if (a_channel->local_sig_id != sig_id) continue; 1647 channel = a_channel; 1648 break; 1649 } 1650 if (!channel) break; 1651 1652 // if received while waiting for le connection response, assume legacy device 1653 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 1654 channel->state = L2CAP_STATE_CLOSED; 1655 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 1656 l2cap_emit_le_channel_opened(channel, 0x0002); 1657 1658 // discard channel 1659 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1660 btstack_memory_l2cap_channel_free(channel); 1661 break; 1662 } 1663 break; 1664 1665 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1666 1667 // get hci connection, bail if not found (must not happen) 1668 connection = hci_connection_for_handle(handle); 1669 if (!connection) return 0; 1670 1671 // check if service registered 1672 le_psm = little_endian_read_16(command, 4); 1673 service = l2cap_le_get_service(le_psm); 1674 1675 if (service){ 1676 1677 uint16_t source_cid = little_endian_read_16(command, 6); 1678 if (source_cid < 0x40){ 1679 // 0x0009 Connection refused - Invalid Source CID 1680 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0009); 1681 return 1; 1682 } 1683 1684 // go through list of channels for this ACL connection and check if we get a match 1685 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1686 while (btstack_linked_list_iterator_has_next(&it)){ 1687 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1688 if (a_channel->con_handle != handle) continue; 1689 if (a_channel->remote_cid != source_cid) continue; 1690 // 0x000a Connection refused - Source CID already allocated 1691 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x000a); 1692 return 1; 1693 } 1694 1695 // security: check encryption 1696 if (service->required_security_level >= LEVEL_2){ 1697 if (sm_encryption_key_size(handle) == 0){ 1698 // 0x0008 Connection refused - insufficient encryption 1699 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0008); 1700 return 1; 1701 } 1702 // anything less than 16 byte key size is insufficient 1703 if (sm_encryption_key_size(handle) < 16){ 1704 // 0x0007 Connection refused – insufficient encryption key size 1705 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0007); 1706 return 1; 1707 } 1708 } 1709 1710 // security: check authencation 1711 if (service->required_security_level >= LEVEL_3){ 1712 if (!sm_authenticated(handle)){ 1713 // 0x0005 Connection refused – insufficient authentication 1714 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0005); 1715 return 1; 1716 } 1717 } 1718 1719 // security: check authorization 1720 if (service->required_security_level >= LEVEL_4){ 1721 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 1722 // 0x0006 Connection refused – insufficient authorization 1723 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0006); 1724 return 1; 1725 } 1726 } 1727 1728 // allocate channel 1729 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 1730 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 1731 if (!channel){ 1732 // 0x0004 Connection refused – no resources available 1733 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0004); 1734 return 1; 1735 } 1736 1737 channel->con_handle = handle; 1738 channel->remote_cid = source_cid; 1739 channel->remote_sig_id = sig_id; 1740 channel->remote_mtu = little_endian_read_16(command, 8); 1741 channel->remote_mps = little_endian_read_16(command, 10); 1742 channel->credits_outgoing = little_endian_read_16(command, 12); 1743 1744 // set initial state 1745 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1746 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 1747 1748 // add to connections list 1749 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1750 1751 // post connection request event 1752 l2cap_emit_le_incoming_connection(channel); 1753 1754 } else { 1755 // Connection refused – LE_PSM not supported 1756 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0002); 1757 } 1758 break; 1759 1760 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 1761 // Find channel for this sig_id and connection handle 1762 channel = NULL; 1763 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1764 while (btstack_linked_list_iterator_has_next(&it)){ 1765 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1766 if (a_channel->con_handle != handle) continue; 1767 if (a_channel->local_sig_id != sig_id) continue; 1768 channel = a_channel; 1769 break; 1770 } 1771 if (!channel) break; 1772 1773 // cid + 0 1774 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 1775 if (result){ 1776 channel->state = L2CAP_STATE_CLOSED; 1777 // map l2cap connection response result to BTstack status enumeration 1778 l2cap_emit_le_channel_opened(channel, result); 1779 1780 // discard channel 1781 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1782 btstack_memory_l2cap_channel_free(channel); 1783 break; 1784 } 1785 1786 // success 1787 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1788 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1789 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 1790 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 1791 channel->state = L2CAP_STATE_OPEN; 1792 l2cap_emit_le_channel_opened(channel, result); 1793 break; 1794 1795 case LE_FLOW_CONTROL_CREDIT: 1796 // find channel 1797 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1798 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1799 if (!channel) { 1800 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1801 break; 1802 } 1803 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1804 credits_before = channel->credits_outgoing; 1805 channel->credits_outgoing += new_credits; 1806 // check for credit overrun 1807 if (credits_before > channel->credits_outgoing){ 1808 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 1809 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1810 break; 1811 } 1812 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 1813 break; 1814 1815 case DISCONNECTION_REQUEST: 1816 // find channel 1817 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1818 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1819 if (!channel) { 1820 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1821 break; 1822 } 1823 channel->remote_sig_id = sig_id; 1824 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1825 break; 1826 1827 #endif 1828 1829 case DISCONNECTION_RESPONSE: 1830 break; 1831 1832 default: 1833 // command unknown -> reject command 1834 return 0; 1835 } 1836 return 1; 1837 } 1838 #endif 1839 1840 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 1841 1842 l2cap_channel_t * l2cap_channel; 1843 (void) l2cap_channel; 1844 1845 // Get Channel ID 1846 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1847 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1848 1849 switch (channel_id) { 1850 1851 #ifdef ENABLE_CLASSIC 1852 case L2CAP_CID_SIGNALING: { 1853 uint16_t command_offset = 8; 1854 while (command_offset < size) { 1855 // handle signaling commands 1856 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1857 1858 // increment command_offset 1859 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1860 } 1861 break; 1862 } 1863 #endif 1864 1865 #ifdef ENABLE_BLE 1866 case L2CAP_CID_SIGNALING_LE: { 1867 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1868 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 1869 if (!valid){ 1870 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1871 } 1872 break; 1873 } 1874 #endif 1875 1876 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1877 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 1878 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1879 } 1880 break; 1881 1882 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1883 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 1884 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1885 } 1886 break; 1887 1888 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 1889 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 1890 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1891 } 1892 break; 1893 1894 default: 1895 #ifdef ENABLE_CLASSIC 1896 // Find channel for this channel_id and connection handle 1897 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 1898 if (l2cap_channel) { 1899 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1900 } 1901 #endif 1902 #ifdef ENABLE_LE_DATA_CHANNELS 1903 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 1904 if (l2cap_channel) { 1905 // credit counting 1906 if (l2cap_channel->credits_incoming == 0){ 1907 log_error("LE Data Channel packet received but no incoming credits"); 1908 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1909 break; 1910 } 1911 l2cap_channel->credits_incoming--; 1912 1913 // automatic credits 1914 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 1915 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 1916 } 1917 1918 // first fragment 1919 uint16_t pos = 0; 1920 if (!l2cap_channel->receive_sdu_len){ 1921 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 1922 l2cap_channel->receive_sdu_pos = 0; 1923 pos += 2; 1924 size -= 2; 1925 } 1926 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 1927 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 1928 // done? 1929 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 1930 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 1931 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 1932 l2cap_channel->receive_sdu_len = 0; 1933 } 1934 } else { 1935 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 1936 } 1937 #endif 1938 break; 1939 } 1940 1941 l2cap_run(); 1942 } 1943 1944 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1945 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 1946 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 1947 if (index < 0) return; 1948 fixed_channels[index].callback = the_packet_handler; 1949 } 1950 1951 #ifdef ENABLE_CLASSIC 1952 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1953 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 1954 channel->state = L2CAP_STATE_CLOSED; 1955 l2cap_emit_channel_closed(channel); 1956 // discard channel 1957 l2cap_stop_rtx(channel); 1958 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1959 btstack_memory_l2cap_channel_free(channel); 1960 } 1961 1962 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 1963 btstack_linked_list_iterator_t it; 1964 btstack_linked_list_iterator_init(&it, services); 1965 while (btstack_linked_list_iterator_has_next(&it)){ 1966 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 1967 if ( service->psm == psm){ 1968 return service; 1969 }; 1970 } 1971 return NULL; 1972 } 1973 1974 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 1975 return l2cap_get_service_internal(&l2cap_services, psm); 1976 } 1977 1978 1979 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 1980 1981 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1982 1983 // check for alread registered psm 1984 l2cap_service_t *service = l2cap_get_service(psm); 1985 if (service) { 1986 log_error("l2cap_register_service: PSM %u already registered", psm); 1987 return L2CAP_SERVICE_ALREADY_REGISTERED; 1988 } 1989 1990 // alloc structure 1991 service = btstack_memory_l2cap_service_get(); 1992 if (!service) { 1993 log_error("l2cap_register_service: no memory for l2cap_service_t"); 1994 return BTSTACK_MEMORY_ALLOC_FAILED; 1995 } 1996 1997 // fill in 1998 service->psm = psm; 1999 service->mtu = mtu; 2000 service->packet_handler = service_packet_handler; 2001 service->required_security_level = security_level; 2002 2003 // add to services list 2004 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 2005 2006 // enable page scan 2007 gap_connectable_control(1); 2008 2009 return 0; 2010 } 2011 2012 uint8_t l2cap_unregister_service(uint16_t psm){ 2013 2014 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 2015 2016 l2cap_service_t *service = l2cap_get_service(psm); 2017 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2018 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 2019 btstack_memory_l2cap_service_free(service); 2020 2021 // disable page scan when no services registered 2022 if (btstack_linked_list_empty(&l2cap_services)) { 2023 gap_connectable_control(0); 2024 } 2025 return 0; 2026 } 2027 #endif 2028 2029 2030 #ifdef ENABLE_LE_DATA_CHANNELS 2031 2032 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 2033 if (!channel->waiting_for_can_send_now) return; 2034 if (channel->send_sdu_buffer) return; 2035 channel->waiting_for_can_send_now = 0; 2036 log_info("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 2037 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 2038 } 2039 2040 // 1BH2222 2041 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 2042 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", 2043 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 2044 uint8_t event[19]; 2045 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 2046 event[1] = sizeof(event) - 2; 2047 event[2] = channel->address_type; 2048 reverse_bd_addr(channel->address, &event[3]); 2049 little_endian_store_16(event, 9, channel->con_handle); 2050 little_endian_store_16(event, 11, channel->psm); 2051 little_endian_store_16(event, 13, channel->local_cid); 2052 little_endian_store_16(event, 15, channel->remote_cid); 2053 little_endian_store_16(event, 17, channel->remote_mtu); 2054 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2055 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2056 } 2057 // 11BH22222 2058 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 2059 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", 2060 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 2061 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 2062 uint8_t event[23]; 2063 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 2064 event[1] = sizeof(event) - 2; 2065 event[2] = status; 2066 event[3] = channel->address_type; 2067 reverse_bd_addr(channel->address, &event[4]); 2068 little_endian_store_16(event, 10, channel->con_handle); 2069 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 2070 little_endian_store_16(event, 13, channel->psm); 2071 little_endian_store_16(event, 15, channel->local_cid); 2072 little_endian_store_16(event, 17, channel->remote_cid); 2073 little_endian_store_16(event, 19, channel->local_mtu); 2074 little_endian_store_16(event, 21, channel->remote_mtu); 2075 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2076 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2077 } 2078 2079 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 2080 btstack_linked_list_iterator_t it; 2081 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2082 while (btstack_linked_list_iterator_has_next(&it)){ 2083 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2084 if ( channel->local_cid == local_cid) { 2085 return channel; 2086 } 2087 } 2088 return NULL; 2089 } 2090 2091 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2092 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 2093 channel->state = L2CAP_STATE_CLOSED; 2094 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 2095 // discard channel 2096 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2097 btstack_memory_l2cap_channel_free(channel); 2098 } 2099 2100 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 2101 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 2102 } 2103 2104 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 2105 2106 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 2107 2108 // check for alread registered psm 2109 l2cap_service_t *service = l2cap_le_get_service(psm); 2110 if (service) { 2111 return L2CAP_SERVICE_ALREADY_REGISTERED; 2112 } 2113 2114 // alloc structure 2115 service = btstack_memory_l2cap_service_get(); 2116 if (!service) { 2117 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 2118 return BTSTACK_MEMORY_ALLOC_FAILED; 2119 } 2120 2121 // fill in 2122 service->psm = psm; 2123 service->mtu = 0; 2124 service->packet_handler = packet_handler; 2125 service->required_security_level = security_level; 2126 2127 // add to services list 2128 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 2129 2130 // done 2131 return 0; 2132 } 2133 2134 uint8_t l2cap_le_unregister_service(uint16_t psm) { 2135 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 2136 l2cap_service_t *service = l2cap_le_get_service(psm); 2137 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2138 2139 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 2140 btstack_memory_l2cap_service_free(service); 2141 return 0; 2142 } 2143 2144 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 2145 // get channel 2146 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2147 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2148 2149 // validate state 2150 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2151 return ERROR_CODE_COMMAND_DISALLOWED; 2152 } 2153 2154 // set state accept connection 2155 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 2156 channel->receive_sdu_buffer = receive_sdu_buffer; 2157 channel->local_mtu = mtu; 2158 channel->new_credits_incoming = initial_credits; 2159 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2160 2161 // test 2162 // channel->new_credits_incoming = 1; 2163 2164 // go 2165 l2cap_run(); 2166 return 0; 2167 } 2168 2169 /** 2170 * @brief Deny incoming LE Data Channel connection due to resource constraints 2171 * @param local_cid L2CAP LE Data Channel Identifier 2172 */ 2173 2174 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 2175 // get channel 2176 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2177 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2178 2179 // validate state 2180 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2181 return ERROR_CODE_COMMAND_DISALLOWED; 2182 } 2183 2184 // set state decline connection 2185 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 2186 channel->reason = 0x04; // no resources available 2187 l2cap_run(); 2188 return 0; 2189 } 2190 2191 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 2192 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 2193 uint16_t * out_local_cid) { 2194 2195 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 2196 2197 2198 hci_connection_t * connection = hci_connection_for_handle(con_handle); 2199 if (!connection) { 2200 log_error("no hci_connection for handle 0x%04x", con_handle); 2201 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 2202 } 2203 2204 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 2205 if (!channel) { 2206 return BTSTACK_MEMORY_ALLOC_FAILED; 2207 } 2208 log_info("l2cap_le_create_channel %p", channel); 2209 2210 // store local_cid 2211 if (out_local_cid){ 2212 *out_local_cid = channel->local_cid; 2213 } 2214 2215 // provide buffer 2216 channel->con_handle = con_handle; 2217 channel->receive_sdu_buffer = receive_sdu_buffer; 2218 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 2219 channel->new_credits_incoming = initial_credits; 2220 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2221 2222 // add to connections list 2223 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2224 2225 // go 2226 l2cap_run(); 2227 return 0; 2228 } 2229 2230 /** 2231 * @brief Provide credtis for LE Data Channel 2232 * @param local_cid L2CAP LE Data Channel Identifier 2233 * @param credits Number additional credits for peer 2234 */ 2235 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2236 2237 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2238 if (!channel) { 2239 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2240 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2241 } 2242 2243 // check state 2244 if (channel->state != L2CAP_STATE_OPEN){ 2245 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 2246 } 2247 2248 // assert incoming credits + credits <= 0xffff 2249 uint32_t total_credits = channel->credits_incoming; 2250 total_credits += channel->new_credits_incoming; 2251 total_credits += credits; 2252 if (total_credits > 0xffff){ 2253 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 2254 channel->new_credits_incoming, credits); 2255 } 2256 2257 // set credits_granted 2258 channel->new_credits_incoming += credits; 2259 2260 // go 2261 l2cap_run(); 2262 return 0; 2263 } 2264 2265 /** 2266 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2267 * @param local_cid L2CAP LE Data Channel Identifier 2268 */ 2269 int l2cap_le_can_send_now(uint16_t local_cid){ 2270 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2271 if (!channel) { 2272 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2273 return 0; 2274 } 2275 2276 // check state 2277 if (channel->state != L2CAP_STATE_OPEN) return 0; 2278 2279 // check queue 2280 if (channel->send_sdu_buffer) return 0; 2281 2282 // fine, go ahead 2283 return 1; 2284 } 2285 2286 /** 2287 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2288 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2289 * so packet handler should be ready to handle it 2290 * @param local_cid L2CAP LE Data Channel Identifier 2291 */ 2292 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2293 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2294 if (!channel) { 2295 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 2296 return 0; 2297 } 2298 channel->waiting_for_can_send_now = 1; 2299 l2cap_le_notify_channel_can_send(channel); 2300 return 0; 2301 } 2302 2303 /** 2304 * @brief Send data via LE Data Channel 2305 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2306 * @param local_cid L2CAP LE Data Channel Identifier 2307 * @param data data to send 2308 * @param size data size 2309 */ 2310 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2311 2312 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2313 if (!channel) { 2314 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2315 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2316 } 2317 2318 if (len > channel->remote_mtu){ 2319 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2320 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2321 } 2322 2323 if (channel->send_sdu_buffer){ 2324 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2325 return BTSTACK_ACL_BUFFERS_FULL; 2326 } 2327 2328 channel->send_sdu_buffer = data; 2329 channel->send_sdu_len = len; 2330 channel->send_sdu_pos = 0; 2331 2332 l2cap_run(); 2333 return 0; 2334 } 2335 2336 /** 2337 * @brief Disconnect from LE Data Channel 2338 * @param local_cid L2CAP LE Data Channel Identifier 2339 */ 2340 uint8_t l2cap_le_disconnect(uint16_t local_cid) 2341 { 2342 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2343 if (!channel) { 2344 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2345 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2346 } 2347 2348 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2349 l2cap_run(); 2350 return 0; 2351 } 2352 2353 #endif 2354