1 /* 2 * Copyright (C) 2009-2012 by Matthias Ringwald 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 MATTHIAS RINGWALD 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 [email protected] 34 * 35 */ 36 37 /* 38 * l2cap.c 39 * 40 * Logical Link Control and Adaption Protocl (L2CAP) 41 * 42 * Created by Matthias Ringwald on 5/16/09. 43 */ 44 45 #include "l2cap.h" 46 #include "hci.h" 47 #include "hci_dump.h" 48 #include "debug.h" 49 #include "btstack_memory.h" 50 51 #include <stdarg.h> 52 #include <string.h> 53 54 #include <stdio.h> 55 56 // nr of buffered acl packets in outgoing queue to get max performance 57 #define NR_BUFFERED_ACL_PACKETS 3 58 59 // used to cache l2cap rejects, echo, and informational requests 60 #define NR_PENDING_SIGNALING_RESPONSES 3 61 62 // offsets for L2CAP SIGNALING COMMANDS 63 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 64 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 65 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 66 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 67 68 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 69 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size); 70 71 // used to cache l2cap rejects, echo, and informational requests 72 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 73 static int signaling_responses_pending; 74 75 static linked_list_t l2cap_channels; 76 static linked_list_t l2cap_services; 77 static void (*packet_handler) (void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) = null_packet_handler; 78 static int new_credits_blocked = 0; 79 80 static btstack_packet_handler_t attribute_protocol_packet_handler; 81 static btstack_packet_handler_t security_protocol_packet_handler; 82 static uint8_t require_security_level2_for_outgoing_sdp; 83 84 // prototypes 85 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 86 static l2cap_service_t * l2cap_get_service(uint16_t psm); 87 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 88 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 89 static void l2cap_emit_connection_request(l2cap_channel_t *channel); 90 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 91 92 93 void l2cap_init(){ 94 new_credits_blocked = 0; 95 signaling_responses_pending = 0; 96 97 l2cap_channels = NULL; 98 l2cap_services = NULL; 99 100 packet_handler = null_packet_handler; 101 attribute_protocol_packet_handler = NULL; 102 security_protocol_packet_handler = NULL; 103 104 require_security_level2_for_outgoing_sdp = 0; 105 106 // 107 // register callback with HCI 108 // 109 hci_register_packet_handler(&l2cap_packet_handler); 110 hci_connectable_control(0); // no services yet 111 } 112 113 114 /** Register L2CAP packet handlers */ 115 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 116 } 117 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 118 packet_handler = handler; 119 } 120 121 // notify client/protocol handler 122 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 123 if (channel->packet_handler) { 124 (* (channel->packet_handler))(type, channel->local_cid, data, size); 125 } else { 126 (*packet_handler)(channel->connection, type, channel->local_cid, data, size); 127 } 128 } 129 130 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 131 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", 132 status, bd_addr_to_str(channel->address), channel->handle, channel->psm, 133 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 134 uint8_t event[23]; 135 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 136 event[1] = sizeof(event) - 2; 137 event[2] = status; 138 bt_flip_addr(&event[3], channel->address); 139 bt_store_16(event, 9, channel->handle); 140 bt_store_16(event, 11, channel->psm); 141 bt_store_16(event, 13, channel->local_cid); 142 bt_store_16(event, 15, channel->remote_cid); 143 bt_store_16(event, 17, channel->local_mtu); 144 bt_store_16(event, 19, channel->remote_mtu); 145 bt_store_16(event, 19, channel->flush_timeout); 146 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 147 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 148 } 149 150 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 151 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 152 uint8_t event[4]; 153 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 154 event[1] = sizeof(event) - 2; 155 bt_store_16(event, 2, channel->local_cid); 156 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 157 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 158 } 159 160 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 161 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 162 bd_addr_to_str(channel->address), channel->handle, channel->psm, channel->local_cid, channel->remote_cid); 163 uint8_t event[16]; 164 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 165 event[1] = sizeof(event) - 2; 166 bt_flip_addr(&event[2], channel->address); 167 bt_store_16(event, 8, channel->handle); 168 bt_store_16(event, 10, channel->psm); 169 bt_store_16(event, 12, channel->local_cid); 170 bt_store_16(event, 14, channel->remote_cid); 171 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 172 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 173 } 174 175 static void l2cap_emit_service_registered(void *connection, uint8_t status, uint16_t psm){ 176 log_info("L2CAP_EVENT_SERVICE_REGISTERED status 0x%x psm 0x%x", status, psm); 177 uint8_t event[5]; 178 event[0] = L2CAP_EVENT_SERVICE_REGISTERED; 179 event[1] = sizeof(event) - 2; 180 event[2] = status; 181 bt_store_16(event, 3, psm); 182 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 183 (*packet_handler)(connection, HCI_EVENT_PACKET, 0, event, sizeof(event)); 184 } 185 186 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 187 188 log_info("L2CAP_EVENT_CREDITS local_cid 0x%x credits %u", channel->local_cid, credits); 189 // track credits 190 channel->packets_granted += credits; 191 192 uint8_t event[5]; 193 event[0] = L2CAP_EVENT_CREDITS; 194 event[1] = sizeof(event) - 2; 195 bt_store_16(event, 2, channel->local_cid); 196 event[4] = credits; 197 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 198 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 199 } 200 201 void l2cap_block_new_credits(uint8_t blocked){ 202 new_credits_blocked = blocked; 203 } 204 205 void l2cap_hand_out_credits(void){ 206 207 if (new_credits_blocked) return; // we're told not to. used by daemon 208 209 linked_item_t *it; 210 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 211 if (!hci_number_free_acl_slots()) return; 212 l2cap_channel_t * channel = (l2cap_channel_t *) it; 213 if (channel->state != L2CAP_STATE_OPEN) continue; 214 if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { 215 l2cap_emit_credits(channel, 1); 216 } 217 } 218 } 219 220 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 221 linked_item_t *it; 222 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 223 l2cap_channel_t * channel = (l2cap_channel_t *) it; 224 if ( channel->local_cid == local_cid) { 225 return channel; 226 } 227 } 228 return NULL; 229 } 230 231 int l2cap_can_send_packet_now(uint16_t local_cid){ 232 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 233 if (!channel) return 0; 234 if (!channel->packets_granted) return 0; 235 return hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET); 236 } 237 238 int l2cap_can_send_connectionless_packet_now(void){ 239 return hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET); 240 } 241 242 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 243 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 244 if (channel) { 245 return channel->remote_mtu; 246 } 247 return 0; 248 } 249 250 static l2cap_channel_t * l2cap_channel_for_rtx_timer(timer_source_t * ts){ 251 linked_item_t *it; 252 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 253 l2cap_channel_t * channel = (l2cap_channel_t *) it; 254 if ( &channel->rtx == ts) { 255 return channel; 256 } 257 } 258 return NULL; 259 } 260 261 static void l2cap_rtx_timeout(timer_source_t * ts){ 262 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 263 if (!ts) return; 264 265 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 266 267 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 268 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 269 // notify client 270 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 271 272 // discard channel 273 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 274 btstack_memory_l2cap_channel_free(channel); 275 } 276 277 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 278 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 279 run_loop_remove_timer(&channel->rtx); 280 } 281 282 static void l2cap_start_rtx(l2cap_channel_t * channel){ 283 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 284 l2cap_stop_rtx(channel); 285 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 286 run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 287 run_loop_add_timer(&channel->rtx); 288 } 289 290 static void l2cap_start_ertx(l2cap_channel_t * channel){ 291 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 292 l2cap_stop_rtx(channel); 293 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 294 run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 295 run_loop_add_timer(&channel->rtx); 296 } 297 298 void l2cap_require_security_level_2_for_outgoing_sdp(){ 299 require_security_level2_for_outgoing_sdp = 1; 300 } 301 302 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 303 return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); 304 } 305 306 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 307 308 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 309 log_info("l2cap_send_signaling_packet, cannot send\n"); 310 return BTSTACK_ACL_BUFFERS_FULL; 311 } 312 313 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 314 hci_reserve_packet_buffer(); 315 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 316 va_list argptr; 317 va_start(argptr, identifier); 318 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 319 va_end(argptr); 320 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 321 return hci_send_acl_packet(acl_buffer, len); 322 } 323 324 #ifdef HAVE_BLE 325 int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 326 327 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 328 log_info("l2cap_send_signaling_packet, cannot send\n"); 329 return BTSTACK_ACL_BUFFERS_FULL; 330 } 331 332 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 333 hci_reserve_packet_buffer(); 334 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 335 va_list argptr; 336 va_start(argptr, identifier); 337 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 338 va_end(argptr); 339 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 340 return hci_send_acl_packet(acl_buffer, len); 341 } 342 #endif 343 344 uint8_t *l2cap_get_outgoing_buffer(void){ 345 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 346 } 347 348 int l2cap_reserve_packet_buffer(void){ 349 return hci_reserve_packet_buffer(); 350 } 351 352 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 353 354 if (!hci_is_packet_buffer_reserved()){ 355 log_error("l2cap_send_prepared called without reserving packet first"); 356 return BTSTACK_ACL_BUFFERS_FULL; 357 } 358 359 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 360 log_info("l2cap_send_prepared cid 0x%02x, cannot send\n", local_cid); 361 return BTSTACK_ACL_BUFFERS_FULL; 362 } 363 364 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 365 if (!channel) { 366 log_error("l2cap_send_prepared no channel for cid 0x%02x\n", local_cid); 367 return -1; // TODO: define error 368 } 369 370 if (channel->packets_granted == 0){ 371 log_error("l2cap_send_prepared cid 0x%02x, no credits!\n", local_cid); 372 return -1; // TODO: define error 373 } 374 375 --channel->packets_granted; 376 377 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used, credits left %u;\n", 378 local_cid, channel->handle, channel->packets_granted); 379 380 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 381 382 // 0 - Connection handle : PB=10 : BC=00 383 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 384 // 2 - ACL length 385 bt_store_16(acl_buffer, 2, len + 4); 386 // 4 - L2CAP packet length 387 bt_store_16(acl_buffer, 4, len + 0); 388 // 6 - L2CAP channel DEST 389 bt_store_16(acl_buffer, 6, channel->remote_cid); 390 // send 391 int err = hci_send_acl_packet(acl_buffer, len+8); 392 393 l2cap_hand_out_credits(); 394 395 return err; 396 } 397 398 int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len){ 399 400 if (!hci_is_packet_buffer_reserved()){ 401 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 402 return BTSTACK_ACL_BUFFERS_FULL; 403 } 404 405 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 406 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send\n", handle, cid); 407 return BTSTACK_ACL_BUFFERS_FULL; 408 } 409 410 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x\n", handle, cid); 411 412 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 413 414 // 0 - Connection handle : PB=10 : BC=00 415 bt_store_16(acl_buffer, 0, handle | (2 << 12) | (0 << 14)); 416 // 2 - ACL length 417 bt_store_16(acl_buffer, 2, len + 4); 418 // 4 - L2CAP packet length 419 bt_store_16(acl_buffer, 4, len + 0); 420 // 6 - L2CAP channel DEST 421 bt_store_16(acl_buffer, 6, cid); 422 // send 423 int err = hci_send_acl_packet(acl_buffer, len+8); 424 425 l2cap_hand_out_credits(); 426 427 return err; 428 } 429 430 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 431 432 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 433 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 434 return BTSTACK_ACL_BUFFERS_FULL; 435 } 436 437 hci_reserve_packet_buffer(); 438 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 439 440 memcpy(&acl_buffer[8], data, len); 441 442 return l2cap_send_prepared(local_cid, len); 443 } 444 445 int l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len){ 446 447 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 448 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", cid); 449 return BTSTACK_ACL_BUFFERS_FULL; 450 } 451 452 hci_reserve_packet_buffer(); 453 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 454 455 memcpy(&acl_buffer[8], data, len); 456 457 return l2cap_send_prepared_connectionless(handle, cid, len); 458 } 459 460 int l2cap_send_echo_request(uint16_t handle, uint8_t *data, uint16_t len){ 461 return l2cap_send_signaling_packet(handle, ECHO_REQUEST, 0x77, len, data); 462 } 463 464 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 465 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 466 } 467 468 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 469 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 470 } 471 472 473 474 // MARK: L2CAP_RUN 475 // process outstanding signaling tasks 476 void l2cap_run(void){ 477 478 // check pending signaling responses 479 while (signaling_responses_pending){ 480 481 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)) break; 482 483 hci_con_handle_t handle = signaling_responses[0].handle; 484 uint8_t sig_id = signaling_responses[0].sig_id; 485 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 486 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 487 488 switch (signaling_responses[0].code){ 489 case CONNECTION_REQUEST: 490 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 491 // also disconnect if result is 0x0003 - security blocked 492 hci_disconnect_security_block(handle); 493 break; 494 case ECHO_REQUEST: 495 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 496 break; 497 case INFORMATION_REQUEST: 498 switch (infoType){ 499 case 1: { // Connectionless MTU 500 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 501 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 502 break; 503 } 504 case 2: { // Extended Features Supported 505 // extended features request supported, only supporing fixed channel map 506 uint32_t features = 0x80; 507 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 508 break; 509 } 510 case 3: { // Fixed Channels Supported 511 uint8_t map[8]; 512 memset(map, 0, 8); 513 map[0] = 0x01; // L2CAP Signaling Channel 514 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 515 break; 516 } 517 default: 518 // all other types are not supported 519 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 520 break; 521 } 522 break; 523 case COMMAND_REJECT: 524 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 525 #ifdef HAVE_BLE 526 case COMMAND_REJECT_LE: 527 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 528 break; 529 #endif 530 default: 531 // should not happen 532 break; 533 } 534 535 // remove first item 536 signaling_responses_pending--; 537 int i; 538 for (i=0; i < signaling_responses_pending; i++){ 539 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 540 } 541 } 542 543 uint8_t config_options[4]; 544 linked_item_t *it; 545 linked_item_t *next; 546 for (it = (linked_item_t *) l2cap_channels; it ; it = next){ 547 next = it->next; // cache next item as current item might get freed 548 549 if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) break; 550 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)) break; 551 552 l2cap_channel_t * channel = (l2cap_channel_t *) it; 553 554 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 555 556 557 switch (channel->state){ 558 559 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 560 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 561 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 562 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 563 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 564 } 565 break; 566 567 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 568 // send connection request - set state first 569 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 570 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 571 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 572 break; 573 574 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 575 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 576 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 577 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); // -- remove from list 578 btstack_memory_l2cap_channel_free(channel); 579 break; 580 581 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 582 channel->state = L2CAP_STATE_CONFIG; 583 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 584 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 585 break; 586 587 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 588 // success, start l2cap handshake 589 channel->local_sig_id = l2cap_next_sig_id(); 590 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 591 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 592 l2cap_start_rtx(channel); 593 break; 594 595 case L2CAP_STATE_CONFIG: 596 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 597 uint16_t flags = 0; 598 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 599 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 600 flags = 1; 601 } else { 602 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 603 } 604 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 605 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 606 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 607 config_options[0] = 1; // MTU 608 config_options[1] = 2; // len param 609 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 610 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 611 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 612 } else { 613 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 614 } 615 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 616 } 617 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 618 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 619 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 620 channel->local_sig_id = l2cap_next_sig_id(); 621 config_options[0] = 1; // MTU 622 config_options[1] = 2; // len param 623 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 624 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 625 l2cap_start_rtx(channel); 626 } 627 if (l2cap_channel_ready_for_open(channel)){ 628 channel->state = L2CAP_STATE_OPEN; 629 l2cap_emit_channel_opened(channel, 0); // success 630 l2cap_emit_credits(channel, 1); 631 } 632 break; 633 634 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 635 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 636 // 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 :) 637 l2cap_finialize_channel_close(channel); // -- remove from list 638 break; 639 640 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 641 channel->local_sig_id = l2cap_next_sig_id(); 642 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 643 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 644 break; 645 default: 646 break; 647 } 648 } 649 } 650 651 uint16_t l2cap_max_mtu(void){ 652 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 653 } 654 655 static void l2cap_handle_connection_complete(uint16_t handle, l2cap_channel_t * channel){ 656 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 657 log_info("l2cap_handle_connection_complete expected state"); 658 // success, start l2cap handshake 659 channel->handle = handle; 660 channel->local_cid = l2cap_next_local_cid(); 661 // check remote SSP feature first 662 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 663 } 664 } 665 666 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 667 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 668 669 // we have been waiting for remote supported features, if both support SSP, 670 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)); 671 if (hci_ssp_supported_on_both_sides(channel->handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 672 // request security level 2 673 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 674 gap_request_security_level(channel->handle, LEVEL_2); 675 return; 676 } 677 // fine, go ahead 678 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 679 } 680 681 // open outgoing L2CAP channel 682 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 683 bd_addr_t address, uint16_t psm, uint16_t mtu){ 684 685 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 686 687 // alloc structure 688 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 689 if (!chan) { 690 // emit error event 691 l2cap_channel_t dummy_channel; 692 BD_ADDR_COPY(dummy_channel.address, address); 693 dummy_channel.psm = psm; 694 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 695 return; 696 } 697 // limit local mtu to max acl packet length 698 if (mtu > l2cap_max_mtu()) { 699 mtu = l2cap_max_mtu(); 700 } 701 702 // fill in 703 BD_ADDR_COPY(chan->address, address); 704 chan->psm = psm; 705 chan->handle = 0; 706 chan->connection = connection; 707 chan->packet_handler = packet_handler; 708 chan->remote_mtu = L2CAP_MINIMAL_MTU; 709 chan->local_mtu = mtu; 710 chan->packets_granted = 0; 711 712 // set initial state 713 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 714 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 715 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 716 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 717 chan->required_security_level = LEVEL_0; 718 719 // add to connections list 720 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 721 722 // check if hci connection is already usable 723 hci_connection_t * conn = hci_connection_for_bd_addr((bd_addr_t*)address); 724 if (conn){ 725 log_info("l2cap_create_channel_internal, hci connection already exists"); 726 l2cap_handle_connection_complete(conn->con_handle, chan); 727 // check ir remote supported fearures are already received 728 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 729 l2cap_handle_remote_supported_features_received(chan); 730 } 731 } 732 733 l2cap_run(); 734 } 735 736 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 737 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 738 // find channel for local_cid 739 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 740 if (channel) { 741 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 742 } 743 // process 744 l2cap_run(); 745 } 746 747 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 748 linked_item_t *it = (linked_item_t *) &l2cap_channels; 749 while (it->next){ 750 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 751 if ( ! BD_ADDR_CMP( channel->address, address) ){ 752 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 753 // failure, forward error code 754 l2cap_emit_channel_opened(channel, status); 755 // discard channel 756 it->next = it->next->next; 757 btstack_memory_l2cap_channel_free(channel); 758 } 759 } else { 760 it = it->next; 761 } 762 } 763 } 764 765 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 766 linked_item_t *it; 767 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 768 l2cap_channel_t * channel = (l2cap_channel_t *) it; 769 if ( ! BD_ADDR_CMP( channel->address, address) ){ 770 l2cap_handle_connection_complete(handle, channel); 771 } 772 } 773 // process 774 l2cap_run(); 775 } 776 777 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 778 779 bd_addr_t address; 780 hci_con_handle_t handle; 781 l2cap_channel_t * channel; 782 linked_item_t *it; 783 int hci_con_used; 784 785 switch(packet[0]){ 786 787 // handle connection complete events 788 case HCI_EVENT_CONNECTION_COMPLETE: 789 bt_flip_addr(address, &packet[5]); 790 if (packet[2] == 0){ 791 handle = READ_BT_16(packet, 3); 792 l2cap_handle_connection_success_for_addr(address, handle); 793 } else { 794 l2cap_handle_connection_failed_for_addr(address, packet[2]); 795 } 796 break; 797 798 // handle successful create connection cancel command 799 case HCI_EVENT_COMMAND_COMPLETE: 800 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 801 if (packet[5] == 0){ 802 bt_flip_addr(address, &packet[6]); 803 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 804 l2cap_handle_connection_failed_for_addr(address, 0x16); 805 } 806 } 807 l2cap_run(); // try sending signaling packets first 808 break; 809 810 case HCI_EVENT_COMMAND_STATUS: 811 l2cap_run(); // try sending signaling packets first 812 break; 813 814 // handle disconnection complete events 815 case HCI_EVENT_DISCONNECTION_COMPLETE: 816 // send l2cap disconnect events for all channels on this handle 817 handle = READ_BT_16(packet, 3); 818 it = (linked_item_t *) &l2cap_channels; 819 while (it->next){ 820 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 821 if ( channel->handle == handle ){ 822 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 823 it->next = it->next->next; 824 l2cap_emit_channel_closed(channel); 825 btstack_memory_l2cap_channel_free(channel); 826 } else { 827 it = it->next; 828 } 829 } 830 break; 831 832 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 833 l2cap_run(); // try sending signaling packets first 834 l2cap_hand_out_credits(); 835 break; 836 837 // HCI Connection Timeouts 838 case L2CAP_EVENT_TIMEOUT_CHECK: 839 handle = READ_BT_16(packet, 2); 840 if (hci_authentication_active_for_handle(handle)) break; 841 hci_con_used = 0; 842 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 843 channel = (l2cap_channel_t *) it; 844 if (channel->handle == handle) { 845 hci_con_used = 1; 846 } 847 } 848 if (hci_con_used) break; 849 if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) break; 850 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 851 break; 852 853 case DAEMON_EVENT_HCI_PACKET_SENT: 854 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 855 channel = (l2cap_channel_t *) it; 856 if (channel->packet_handler) { 857 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 858 } 859 } 860 if (attribute_protocol_packet_handler) { 861 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 862 } 863 if (security_protocol_packet_handler) { 864 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 865 } 866 break; 867 868 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 869 handle = READ_BT_16(packet, 3); 870 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 871 channel = (l2cap_channel_t *) it; 872 if (channel->handle != handle) continue; 873 l2cap_handle_remote_supported_features_received(channel); 874 break; 875 } 876 877 case GAP_SECURITY_LEVEL: 878 handle = READ_BT_16(packet, 2); 879 log_info("l2cap - security level update"); 880 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 881 channel = (l2cap_channel_t *) it; 882 if (channel->handle != handle) continue; 883 884 log_info("l2cap - state %u", channel->state); 885 886 gap_security_level_t actual_level = packet[4]; 887 gap_security_level_t required_level = channel->required_security_level; 888 889 switch (channel->state){ 890 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 891 if (actual_level >= required_level){ 892 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 893 l2cap_emit_connection_request(channel); 894 } else { 895 channel->reason = 0x03; // security block 896 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 897 } 898 break; 899 900 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 901 if (actual_level >= required_level){ 902 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 903 } else { 904 // disconnnect, authentication not good enough 905 hci_disconnect_security_block(handle); 906 } 907 break; 908 909 default: 910 break; 911 } 912 } 913 break; 914 915 default: 916 break; 917 } 918 919 // pass on 920 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 921 922 l2cap_run(); 923 } 924 925 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 926 channel->remote_sig_id = identifier; 927 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 928 l2cap_run(); 929 } 930 931 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 932 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 933 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 934 signaling_responses[signaling_responses_pending].handle = handle; 935 signaling_responses[signaling_responses_pending].code = code; 936 signaling_responses[signaling_responses_pending].sig_id = sig_id; 937 signaling_responses[signaling_responses_pending].data = data; 938 signaling_responses_pending++; 939 l2cap_run(); 940 } 941 } 942 943 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 944 945 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 946 l2cap_service_t *service = l2cap_get_service(psm); 947 if (!service) { 948 // 0x0002 PSM not supported 949 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 950 return; 951 } 952 953 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 954 if (!hci_connection) { 955 // 956 log_error("no hci_connection for handle %u\n", handle); 957 return; 958 } 959 960 // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP 961 if ( hci_ssp_supported_on_both_sides(handle) 962 && gap_security_level(handle) == LEVEL_0 963 && !l2cap_security_level_0_allowed_for_PSM(psm)){ 964 965 // 0x0003 Security Block 966 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); 967 return; 968 } 969 970 971 // alloc structure 972 // log_info("l2cap_handle_connection_request register channel\n"); 973 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 974 if (!channel){ 975 // 0x0004 No resources available 976 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 977 return; 978 } 979 980 // fill in 981 BD_ADDR_COPY(channel->address, hci_connection->address); 982 channel->psm = psm; 983 channel->handle = handle; 984 channel->connection = service->connection; 985 channel->packet_handler = service->packet_handler; 986 channel->local_cid = l2cap_next_local_cid(); 987 channel->remote_cid = source_cid; 988 channel->local_mtu = service->mtu; 989 channel->remote_mtu = L2CAP_DEFAULT_MTU; 990 channel->packets_granted = 0; 991 channel->remote_sig_id = sig_id; 992 channel->required_security_level = service->required_security_level; 993 994 // limit local mtu to max acl packet length 995 if (channel->local_mtu > l2cap_max_mtu()) { 996 channel->local_mtu = l2cap_max_mtu(); 997 } 998 999 // set initial state 1000 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1001 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1002 1003 // add to connections list 1004 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 1005 1006 // assert security requirements 1007 gap_request_security_level(handle, channel->required_security_level); 1008 } 1009 1010 void l2cap_accept_connection_internal(uint16_t local_cid){ 1011 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1012 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1013 if (!channel) { 1014 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 1015 return; 1016 } 1017 1018 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1019 1020 // process 1021 l2cap_run(); 1022 } 1023 1024 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 1025 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 1026 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1027 if (!channel) { 1028 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 1029 return; 1030 } 1031 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1032 channel->reason = reason; 1033 l2cap_run(); 1034 } 1035 1036 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1037 1038 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1039 1040 uint16_t flags = READ_BT_16(command, 6); 1041 if (flags & 1) { 1042 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1043 } 1044 1045 // accept the other's configuration options 1046 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1047 uint16_t pos = 8; 1048 while (pos < end_pos){ 1049 uint8_t option_hint = command[pos] >> 7; 1050 uint8_t option_type = command[pos] & 0x7f; 1051 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1052 pos++; 1053 uint8_t length = command[pos++]; 1054 // MTU { type(8): 1, len(8):2, MTU(16) } 1055 if (option_type == 1 && length == 2){ 1056 channel->remote_mtu = READ_BT_16(command, pos); 1057 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 1058 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1059 } 1060 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1061 if (option_type == 2 && length == 2){ 1062 channel->flush_timeout = READ_BT_16(command, pos); 1063 } 1064 // check for unknown options 1065 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1066 log_info("l2cap cid %u, unknown options", channel->local_cid); 1067 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1068 } 1069 pos += length; 1070 } 1071 } 1072 1073 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1074 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 1075 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1076 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1077 return 1; 1078 } 1079 1080 1081 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1082 1083 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1084 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1085 uint16_t result = 0; 1086 1087 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 1088 1089 // handle DISCONNECT REQUESTS seperately 1090 if (code == DISCONNECTION_REQUEST){ 1091 switch (channel->state){ 1092 case L2CAP_STATE_CONFIG: 1093 case L2CAP_STATE_OPEN: 1094 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1095 case L2CAP_STATE_WAIT_DISCONNECT: 1096 l2cap_handle_disconnect_request(channel, identifier); 1097 break; 1098 1099 default: 1100 // ignore in other states 1101 break; 1102 } 1103 return; 1104 } 1105 1106 // @STATEMACHINE(l2cap) 1107 switch (channel->state) { 1108 1109 case L2CAP_STATE_WAIT_CONNECT_RSP: 1110 switch (code){ 1111 case CONNECTION_RESPONSE: 1112 l2cap_stop_rtx(channel); 1113 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1114 switch (result) { 1115 case 0: 1116 // successful connection 1117 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1118 channel->state = L2CAP_STATE_CONFIG; 1119 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1120 break; 1121 case 1: 1122 // connection pending. get some coffee, but start the ERTX 1123 l2cap_start_ertx(channel); 1124 break; 1125 default: 1126 // channel closed 1127 channel->state = L2CAP_STATE_CLOSED; 1128 // map l2cap connection response result to BTstack status enumeration 1129 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1130 1131 // drop link key if security block 1132 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1133 hci_drop_link_key_for_bd_addr(&channel->address); 1134 } 1135 1136 // discard channel 1137 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1138 btstack_memory_l2cap_channel_free(channel); 1139 break; 1140 } 1141 break; 1142 1143 default: 1144 //@TODO: implement other signaling packets 1145 break; 1146 } 1147 break; 1148 1149 case L2CAP_STATE_CONFIG: 1150 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1151 switch (code) { 1152 case CONFIGURE_REQUEST: 1153 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1154 l2cap_signaling_handle_configure_request(channel, command); 1155 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1156 // only done if continuation not set 1157 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1158 } 1159 break; 1160 case CONFIGURE_RESPONSE: 1161 l2cap_stop_rtx(channel); 1162 switch (result){ 1163 case 0: // success 1164 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1165 break; 1166 case 4: // pending 1167 l2cap_start_ertx(channel); 1168 break; 1169 default: 1170 // retry on negative result 1171 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1172 break; 1173 } 1174 break; 1175 default: 1176 break; 1177 } 1178 if (l2cap_channel_ready_for_open(channel)){ 1179 // for open: 1180 channel->state = L2CAP_STATE_OPEN; 1181 l2cap_emit_channel_opened(channel, 0); 1182 l2cap_emit_credits(channel, 1); 1183 } 1184 break; 1185 1186 case L2CAP_STATE_WAIT_DISCONNECT: 1187 switch (code) { 1188 case DISCONNECTION_RESPONSE: 1189 l2cap_finialize_channel_close(channel); 1190 break; 1191 default: 1192 //@TODO: implement other signaling packets 1193 break; 1194 } 1195 break; 1196 1197 case L2CAP_STATE_CLOSED: 1198 // @TODO handle incoming requests 1199 break; 1200 1201 case L2CAP_STATE_OPEN: 1202 //@TODO: implement other signaling packets, e.g. re-configure 1203 break; 1204 default: 1205 break; 1206 } 1207 // log_info("new state %u\n", channel->state); 1208 } 1209 1210 1211 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1212 1213 // get code, signalind identifier and command len 1214 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1215 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1216 1217 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1218 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1219 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1220 return; 1221 } 1222 1223 // general commands without an assigned channel 1224 switch(code) { 1225 1226 case CONNECTION_REQUEST: { 1227 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1228 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1229 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1230 return; 1231 } 1232 1233 case ECHO_REQUEST: 1234 l2cap_register_signaling_response(handle, code, sig_id, 0); 1235 return; 1236 1237 case INFORMATION_REQUEST: { 1238 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1239 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1240 return; 1241 } 1242 1243 default: 1244 break; 1245 } 1246 1247 1248 // Get potential destination CID 1249 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1250 1251 // Find channel for this sig_id and connection handle 1252 linked_item_t *it; 1253 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1254 l2cap_channel_t * channel = (l2cap_channel_t *) it; 1255 if (channel->handle == handle) { 1256 if (code & 1) { 1257 // match odd commands (responses) by previous signaling identifier 1258 if (channel->local_sig_id == sig_id) { 1259 l2cap_signaling_handler_channel(channel, command); 1260 break; 1261 } 1262 } else { 1263 // match even commands (requests) by local channel id 1264 if (channel->local_cid == dest_cid) { 1265 l2cap_signaling_handler_channel(channel, command); 1266 break; 1267 } 1268 } 1269 } 1270 } 1271 } 1272 1273 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1274 1275 // Get Channel ID 1276 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1277 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1278 1279 switch (channel_id) { 1280 1281 case L2CAP_CID_SIGNALING: { 1282 1283 uint16_t command_offset = 8; 1284 while (command_offset < size) { 1285 1286 // handle signaling commands 1287 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1288 1289 // increment command_offset 1290 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1291 } 1292 break; 1293 } 1294 1295 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1296 if (attribute_protocol_packet_handler) { 1297 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1298 } 1299 break; 1300 1301 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1302 if (security_protocol_packet_handler) { 1303 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1304 } 1305 break; 1306 1307 case L2CAP_CID_SIGNALING_LE: { 1308 // not implemented yet for LE Peripheral 1309 uint8_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1310 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1311 break; 1312 } 1313 1314 default: { 1315 // Find channel for this channel_id and connection handle 1316 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1317 if (channel) { 1318 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1319 } 1320 break; 1321 } 1322 } 1323 } 1324 1325 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1326 switch (packet_type) { 1327 case HCI_EVENT_PACKET: 1328 l2cap_event_handler(packet, size); 1329 break; 1330 case HCI_ACL_DATA_PACKET: 1331 l2cap_acl_handler(packet, size); 1332 break; 1333 default: 1334 break; 1335 } 1336 l2cap_run(); 1337 } 1338 1339 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1340 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1341 channel->state = L2CAP_STATE_CLOSED; 1342 l2cap_emit_channel_closed(channel); 1343 // discard channel 1344 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1345 btstack_memory_l2cap_channel_free(channel); 1346 } 1347 1348 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1349 linked_item_t *it; 1350 1351 // close open channels 1352 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 1353 l2cap_service_t * service = ((l2cap_service_t *) it); 1354 if ( service->psm == psm){ 1355 return service; 1356 }; 1357 } 1358 return NULL; 1359 } 1360 1361 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 1362 1363 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1364 1365 // check for alread registered psm 1366 // TODO: emit error event 1367 l2cap_service_t *service = l2cap_get_service(psm); 1368 if (service) { 1369 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1370 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1371 return; 1372 } 1373 1374 // alloc structure 1375 // TODO: emit error event 1376 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1377 if (!service) { 1378 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1379 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1380 return; 1381 } 1382 1383 // fill in 1384 service->psm = psm; 1385 service->mtu = mtu; 1386 service->connection = connection; 1387 service->packet_handler = packet_handler; 1388 service->required_security_level = security_level; 1389 1390 // add to services list 1391 linked_list_add(&l2cap_services, (linked_item_t *) service); 1392 1393 // enable page scan 1394 hci_connectable_control(1); 1395 1396 // done 1397 l2cap_emit_service_registered(connection, 0, psm); 1398 } 1399 1400 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1401 1402 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1403 1404 l2cap_service_t *service = l2cap_get_service(psm); 1405 if (!service) return; 1406 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1407 btstack_memory_l2cap_service_free(service); 1408 1409 // disable page scan when no services registered 1410 if (!linked_list_empty(&l2cap_services)) return; 1411 hci_connectable_control(0); 1412 } 1413 1414 // 1415 void l2cap_close_connection(void *connection){ 1416 linked_item_t *it; 1417 1418 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1419 l2cap_channel_t * channel; 1420 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1421 channel = (l2cap_channel_t *) it; 1422 if (channel->connection == connection) { 1423 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1424 } 1425 } 1426 1427 // unregister services 1428 it = (linked_item_t *) &l2cap_services; 1429 while (it->next) { 1430 l2cap_service_t * service = (l2cap_service_t *) it->next; 1431 if (service->connection == connection){ 1432 it->next = it->next->next; 1433 btstack_memory_l2cap_service_free(service); 1434 } else { 1435 it = it->next; 1436 } 1437 } 1438 1439 // process 1440 l2cap_run(); 1441 } 1442 1443 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1444 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1445 switch(channel_id){ 1446 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1447 attribute_protocol_packet_handler = packet_handler; 1448 break; 1449 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1450 security_protocol_packet_handler = packet_handler; 1451 break; 1452 } 1453 } 1454 1455 #ifdef HAVE_BLE 1456 // Request LE connection parameter update 1457 int l2cap_le_request_connection_parameter_update(uint16_t handle, uint16_t interval_min, uint16_t interval_max, uint16_t slave_latency, uint16_t timeout_multiplier){ 1458 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 1459 log_info("l2cap_send_signaling_packet, cannot send\n"); 1460 return BTSTACK_ACL_BUFFERS_FULL; 1461 } 1462 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1463 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1464 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1465 return hci_send_acl_packet(acl_buffer, len); 1466 } 1467 #endif 1468 1469