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 // no need to stop timer here, it is removed from list during timer callback 274 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 275 btstack_memory_l2cap_channel_free(channel); 276 } 277 278 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 279 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 280 run_loop_remove_timer(&channel->rtx); 281 } 282 283 static void l2cap_start_rtx(l2cap_channel_t * channel){ 284 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 285 l2cap_stop_rtx(channel); 286 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 287 run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 288 run_loop_add_timer(&channel->rtx); 289 } 290 291 static void l2cap_start_ertx(l2cap_channel_t * channel){ 292 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 293 l2cap_stop_rtx(channel); 294 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 295 run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 296 run_loop_add_timer(&channel->rtx); 297 } 298 299 void l2cap_require_security_level_2_for_outgoing_sdp(){ 300 require_security_level2_for_outgoing_sdp = 1; 301 } 302 303 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 304 return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); 305 } 306 307 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 308 309 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 310 log_info("l2cap_send_signaling_packet, cannot send\n"); 311 return BTSTACK_ACL_BUFFERS_FULL; 312 } 313 314 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 315 hci_reserve_packet_buffer(); 316 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 317 va_list argptr; 318 va_start(argptr, identifier); 319 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 320 va_end(argptr); 321 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 322 return hci_send_acl_packet_buffer(len); 323 } 324 325 #ifdef HAVE_BLE 326 int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 327 328 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 329 log_info("l2cap_send_signaling_packet, cannot send\n"); 330 return BTSTACK_ACL_BUFFERS_FULL; 331 } 332 333 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 334 hci_reserve_packet_buffer(); 335 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 336 va_list argptr; 337 va_start(argptr, identifier); 338 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 339 va_end(argptr); 340 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 341 return hci_send_acl_packet_buffer(len); 342 } 343 #endif 344 345 uint8_t *l2cap_get_outgoing_buffer(void){ 346 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 347 } 348 349 int l2cap_reserve_packet_buffer(void){ 350 return hci_reserve_packet_buffer(); 351 } 352 353 void l2cap_release_packet_buffer(void){ 354 hci_release_packet_buffer(); 355 } 356 357 358 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 359 360 if (!hci_is_packet_buffer_reserved()){ 361 log_error("l2cap_send_prepared called without reserving packet first"); 362 return BTSTACK_ACL_BUFFERS_FULL; 363 } 364 365 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 366 log_info("l2cap_send_prepared cid 0x%02x, cannot send\n", local_cid); 367 return BTSTACK_ACL_BUFFERS_FULL; 368 } 369 370 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 371 if (!channel) { 372 log_error("l2cap_send_prepared no channel for cid 0x%02x\n", local_cid); 373 return -1; // TODO: define error 374 } 375 376 if (channel->packets_granted == 0){ 377 log_error("l2cap_send_prepared cid 0x%02x, no credits!\n", local_cid); 378 return -1; // TODO: define error 379 } 380 381 --channel->packets_granted; 382 383 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used, credits left %u;\n", 384 local_cid, channel->handle, channel->packets_granted); 385 386 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 387 388 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 389 390 // 0 - Connection handle : PB=pb : BC=00 391 bt_store_16(acl_buffer, 0, channel->handle | (pb << 12) | (0 << 14)); 392 // 2 - ACL length 393 bt_store_16(acl_buffer, 2, len + 4); 394 // 4 - L2CAP packet length 395 bt_store_16(acl_buffer, 4, len + 0); 396 // 6 - L2CAP channel DEST 397 bt_store_16(acl_buffer, 6, channel->remote_cid); 398 // send 399 int err = hci_send_acl_packet_buffer(len+8); 400 401 l2cap_hand_out_credits(); 402 403 return err; 404 } 405 406 int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len){ 407 408 if (!hci_is_packet_buffer_reserved()){ 409 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 410 return BTSTACK_ACL_BUFFERS_FULL; 411 } 412 413 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 414 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send\n", handle, cid); 415 return BTSTACK_ACL_BUFFERS_FULL; 416 } 417 418 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x\n", handle, cid); 419 420 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 421 422 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 423 424 // 0 - Connection handle : PB=pb : BC=00 425 bt_store_16(acl_buffer, 0, handle | (pb << 12) | (0 << 14)); 426 // 2 - ACL length 427 bt_store_16(acl_buffer, 2, len + 4); 428 // 4 - L2CAP packet length 429 bt_store_16(acl_buffer, 4, len + 0); 430 // 6 - L2CAP channel DEST 431 bt_store_16(acl_buffer, 6, cid); 432 // send 433 int err = hci_send_acl_packet_buffer(len+8); 434 435 l2cap_hand_out_credits(); 436 437 return err; 438 } 439 440 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 441 442 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 443 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 444 return BTSTACK_ACL_BUFFERS_FULL; 445 } 446 447 hci_reserve_packet_buffer(); 448 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 449 450 memcpy(&acl_buffer[8], data, len); 451 452 return l2cap_send_prepared(local_cid, len); 453 } 454 455 int l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len){ 456 457 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 458 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", cid); 459 return BTSTACK_ACL_BUFFERS_FULL; 460 } 461 462 hci_reserve_packet_buffer(); 463 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 464 465 memcpy(&acl_buffer[8], data, len); 466 467 return l2cap_send_prepared_connectionless(handle, cid, len); 468 } 469 470 int l2cap_send_echo_request(uint16_t handle, uint8_t *data, uint16_t len){ 471 return l2cap_send_signaling_packet(handle, ECHO_REQUEST, 0x77, len, data); 472 } 473 474 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 475 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 476 } 477 478 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 479 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 480 } 481 482 483 484 // MARK: L2CAP_RUN 485 // process outstanding signaling tasks 486 void l2cap_run(void){ 487 488 // check pending signaling responses 489 while (signaling_responses_pending){ 490 491 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)) break; 492 493 hci_con_handle_t handle = signaling_responses[0].handle; 494 uint8_t sig_id = signaling_responses[0].sig_id; 495 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 496 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 497 498 switch (signaling_responses[0].code){ 499 case CONNECTION_REQUEST: 500 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 501 // also disconnect if result is 0x0003 - security blocked 502 hci_disconnect_security_block(handle); 503 break; 504 case ECHO_REQUEST: 505 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 506 break; 507 case INFORMATION_REQUEST: 508 switch (infoType){ 509 case 1: { // Connectionless MTU 510 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 511 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 512 break; 513 } 514 case 2: { // Extended Features Supported 515 // extended features request supported, only supporing fixed channel map 516 uint32_t features = 0x80; 517 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 518 break; 519 } 520 case 3: { // Fixed Channels Supported 521 uint8_t map[8]; 522 memset(map, 0, 8); 523 map[0] = 0x01; // L2CAP Signaling Channel 524 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 525 break; 526 } 527 default: 528 // all other types are not supported 529 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 530 break; 531 } 532 break; 533 case COMMAND_REJECT: 534 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 535 #ifdef HAVE_BLE 536 case COMMAND_REJECT_LE: 537 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 538 break; 539 #endif 540 default: 541 // should not happen 542 break; 543 } 544 545 // remove first item 546 signaling_responses_pending--; 547 int i; 548 for (i=0; i < signaling_responses_pending; i++){ 549 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 550 } 551 } 552 553 uint8_t config_options[4]; 554 linked_item_t *it; 555 linked_item_t *next; 556 for (it = (linked_item_t *) l2cap_channels; it ; it = next){ 557 next = it->next; // cache next item as current item might get freed 558 559 if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) break; 560 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)) break; 561 562 l2cap_channel_t * channel = (l2cap_channel_t *) it; 563 564 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 565 566 567 switch (channel->state){ 568 569 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 570 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 571 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 572 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 573 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 574 } 575 break; 576 577 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 578 // send connection request - set state first 579 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 580 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 581 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 582 break; 583 584 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 585 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 586 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 587 l2cap_stop_rtx(channel); 588 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); // -- remove from list 589 btstack_memory_l2cap_channel_free(channel); 590 break; 591 592 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 593 channel->state = L2CAP_STATE_CONFIG; 594 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 595 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 596 break; 597 598 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 599 // success, start l2cap handshake 600 channel->local_sig_id = l2cap_next_sig_id(); 601 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 602 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 603 l2cap_start_rtx(channel); 604 break; 605 606 case L2CAP_STATE_CONFIG: 607 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 608 uint16_t flags = 0; 609 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 610 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 611 flags = 1; 612 } else { 613 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 614 } 615 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 616 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 617 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 618 config_options[0] = 1; // MTU 619 config_options[1] = 2; // len param 620 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 621 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 622 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 623 } else { 624 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 625 } 626 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 627 } 628 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 629 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 630 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 631 channel->local_sig_id = l2cap_next_sig_id(); 632 config_options[0] = 1; // MTU 633 config_options[1] = 2; // len param 634 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 635 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 636 l2cap_start_rtx(channel); 637 } 638 if (l2cap_channel_ready_for_open(channel)){ 639 channel->state = L2CAP_STATE_OPEN; 640 l2cap_emit_channel_opened(channel, 0); // success 641 l2cap_emit_credits(channel, 1); 642 } 643 break; 644 645 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 646 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 647 // 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 :) 648 l2cap_finialize_channel_close(channel); // -- remove from list 649 break; 650 651 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 652 channel->local_sig_id = l2cap_next_sig_id(); 653 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 654 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 655 break; 656 default: 657 break; 658 } 659 } 660 } 661 662 uint16_t l2cap_max_mtu(void){ 663 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 664 } 665 666 static void l2cap_handle_connection_complete(uint16_t handle, l2cap_channel_t * channel){ 667 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 668 log_info("l2cap_handle_connection_complete expected state"); 669 // success, start l2cap handshake 670 channel->handle = handle; 671 channel->local_cid = l2cap_next_local_cid(); 672 // check remote SSP feature first 673 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 674 } 675 } 676 677 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 678 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 679 680 // we have been waiting for remote supported features, if both support SSP, 681 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)); 682 if (hci_ssp_supported_on_both_sides(channel->handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 683 // request security level 2 684 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 685 gap_request_security_level(channel->handle, LEVEL_2); 686 return; 687 } 688 // fine, go ahead 689 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 690 } 691 692 // open outgoing L2CAP channel 693 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 694 bd_addr_t address, uint16_t psm, uint16_t mtu){ 695 696 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 697 698 // alloc structure 699 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 700 if (!chan) { 701 // emit error event 702 l2cap_channel_t dummy_channel; 703 BD_ADDR_COPY(dummy_channel.address, address); 704 dummy_channel.psm = psm; 705 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 706 return; 707 } 708 // limit local mtu to max acl packet length 709 if (mtu > l2cap_max_mtu()) { 710 mtu = l2cap_max_mtu(); 711 } 712 713 // fill in 714 BD_ADDR_COPY(chan->address, address); 715 chan->psm = psm; 716 chan->handle = 0; 717 chan->connection = connection; 718 chan->packet_handler = packet_handler; 719 chan->remote_mtu = L2CAP_MINIMAL_MTU; 720 chan->local_mtu = mtu; 721 chan->packets_granted = 0; 722 723 // set initial state 724 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 725 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 726 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 727 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 728 chan->required_security_level = LEVEL_0; 729 730 // add to connections list 731 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 732 733 // check if hci connection is already usable 734 hci_connection_t * conn = hci_connection_for_bd_addr_and_type((bd_addr_t*)address, BD_ADDR_TYPE_CLASSIC); 735 if (conn){ 736 log_info("l2cap_create_channel_internal, hci connection already exists"); 737 l2cap_handle_connection_complete(conn->con_handle, chan); 738 // check ir remote supported fearures are already received 739 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 740 l2cap_handle_remote_supported_features_received(chan); 741 } 742 } 743 744 l2cap_run(); 745 } 746 747 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 748 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 749 // find channel for local_cid 750 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 751 if (channel) { 752 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 753 } 754 // process 755 l2cap_run(); 756 } 757 758 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 759 linked_item_t *it = (linked_item_t *) &l2cap_channels; 760 while (it->next){ 761 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 762 if ( ! BD_ADDR_CMP( channel->address, address) ){ 763 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 764 // failure, forward error code 765 l2cap_emit_channel_opened(channel, status); 766 // discard channel 767 it->next = it->next->next; 768 l2cap_stop_rtx(channel); 769 btstack_memory_l2cap_channel_free(channel); 770 } 771 } else { 772 it = it->next; 773 } 774 } 775 } 776 777 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 778 linked_item_t *it; 779 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 780 l2cap_channel_t * channel = (l2cap_channel_t *) it; 781 if ( ! BD_ADDR_CMP( channel->address, address) ){ 782 l2cap_handle_connection_complete(handle, channel); 783 } 784 } 785 // process 786 l2cap_run(); 787 } 788 789 void l2cap_event_handler(uint8_t *packet, uint16_t size){ 790 791 bd_addr_t address; 792 hci_con_handle_t handle; 793 l2cap_channel_t * channel; 794 linked_item_t *it; 795 int hci_con_used; 796 797 switch(packet[0]){ 798 799 // handle connection complete events 800 case HCI_EVENT_CONNECTION_COMPLETE: 801 bt_flip_addr(address, &packet[5]); 802 if (packet[2] == 0){ 803 handle = READ_BT_16(packet, 3); 804 l2cap_handle_connection_success_for_addr(address, handle); 805 } else { 806 l2cap_handle_connection_failed_for_addr(address, packet[2]); 807 } 808 break; 809 810 // handle successful create connection cancel command 811 case HCI_EVENT_COMMAND_COMPLETE: 812 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 813 if (packet[5] == 0){ 814 bt_flip_addr(address, &packet[6]); 815 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 816 l2cap_handle_connection_failed_for_addr(address, 0x16); 817 } 818 } 819 l2cap_run(); // try sending signaling packets first 820 break; 821 822 case HCI_EVENT_COMMAND_STATUS: 823 l2cap_run(); // try sending signaling packets first 824 break; 825 826 // handle disconnection complete events 827 case HCI_EVENT_DISCONNECTION_COMPLETE: 828 // send l2cap disconnect events for all channels on this handle 829 handle = READ_BT_16(packet, 3); 830 it = (linked_item_t *) &l2cap_channels; 831 while (it->next){ 832 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 833 if ( channel->handle == handle ){ 834 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 835 it->next = it->next->next; 836 l2cap_emit_channel_closed(channel); 837 l2cap_stop_rtx(channel); 838 btstack_memory_l2cap_channel_free(channel); 839 } else { 840 it = it->next; 841 } 842 } 843 break; 844 845 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 846 l2cap_run(); // try sending signaling packets first 847 l2cap_hand_out_credits(); 848 break; 849 850 // HCI Connection Timeouts 851 case L2CAP_EVENT_TIMEOUT_CHECK: 852 handle = READ_BT_16(packet, 2); 853 if (hci_authentication_active_for_handle(handle)) break; 854 hci_con_used = 0; 855 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 856 channel = (l2cap_channel_t *) it; 857 if (channel->handle == handle) { 858 hci_con_used = 1; 859 } 860 } 861 if (hci_con_used) break; 862 if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) break; 863 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 864 break; 865 866 case DAEMON_EVENT_HCI_PACKET_SENT: 867 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 868 channel = (l2cap_channel_t *) it; 869 if (channel->packet_handler) { 870 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 871 } 872 } 873 if (attribute_protocol_packet_handler) { 874 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 875 } 876 if (security_protocol_packet_handler) { 877 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 878 } 879 break; 880 881 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 882 handle = READ_BT_16(packet, 3); 883 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 884 channel = (l2cap_channel_t *) it; 885 if (channel->handle != handle) continue; 886 l2cap_handle_remote_supported_features_received(channel); 887 break; 888 } 889 890 case GAP_SECURITY_LEVEL: 891 handle = READ_BT_16(packet, 2); 892 log_info("l2cap - security level update"); 893 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 894 channel = (l2cap_channel_t *) it; 895 if (channel->handle != handle) continue; 896 897 log_info("l2cap - state %u", channel->state); 898 899 gap_security_level_t actual_level = packet[4]; 900 gap_security_level_t required_level = channel->required_security_level; 901 902 switch (channel->state){ 903 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 904 if (actual_level >= required_level){ 905 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 906 l2cap_emit_connection_request(channel); 907 } else { 908 channel->reason = 0x03; // security block 909 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 910 } 911 break; 912 913 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 914 if (actual_level >= required_level){ 915 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 916 } else { 917 // disconnnect, authentication not good enough 918 hci_disconnect_security_block(handle); 919 } 920 break; 921 922 default: 923 break; 924 } 925 } 926 break; 927 928 default: 929 break; 930 } 931 932 // pass on: main packet handler, att and sm packet handlers 933 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 934 if (attribute_protocol_packet_handler){ 935 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 936 } 937 if (security_protocol_packet_handler) { 938 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 939 } 940 941 l2cap_run(); 942 } 943 944 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 945 channel->remote_sig_id = identifier; 946 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 947 l2cap_run(); 948 } 949 950 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 951 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 952 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 953 signaling_responses[signaling_responses_pending].handle = handle; 954 signaling_responses[signaling_responses_pending].code = code; 955 signaling_responses[signaling_responses_pending].sig_id = sig_id; 956 signaling_responses[signaling_responses_pending].data = data; 957 signaling_responses_pending++; 958 l2cap_run(); 959 } 960 } 961 962 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 963 964 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 965 l2cap_service_t *service = l2cap_get_service(psm); 966 if (!service) { 967 // 0x0002 PSM not supported 968 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 969 return; 970 } 971 972 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 973 if (!hci_connection) { 974 // 975 log_error("no hci_connection for handle %u\n", handle); 976 return; 977 } 978 979 // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP 980 if ( hci_ssp_supported_on_both_sides(handle) 981 && gap_security_level(handle) == LEVEL_0 982 && !l2cap_security_level_0_allowed_for_PSM(psm)){ 983 984 // 0x0003 Security Block 985 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); 986 return; 987 } 988 989 990 // alloc structure 991 // log_info("l2cap_handle_connection_request register channel\n"); 992 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 993 if (!channel){ 994 // 0x0004 No resources available 995 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 996 return; 997 } 998 999 // fill in 1000 BD_ADDR_COPY(channel->address, hci_connection->address); 1001 channel->psm = psm; 1002 channel->handle = handle; 1003 channel->connection = service->connection; 1004 channel->packet_handler = service->packet_handler; 1005 channel->local_cid = l2cap_next_local_cid(); 1006 channel->remote_cid = source_cid; 1007 channel->local_mtu = service->mtu; 1008 channel->remote_mtu = L2CAP_DEFAULT_MTU; 1009 channel->packets_granted = 0; 1010 channel->remote_sig_id = sig_id; 1011 channel->required_security_level = service->required_security_level; 1012 1013 // limit local mtu to max acl packet length 1014 if (channel->local_mtu > l2cap_max_mtu()) { 1015 channel->local_mtu = l2cap_max_mtu(); 1016 } 1017 1018 // set initial state 1019 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1020 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1021 1022 // add to connections list 1023 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 1024 1025 // assert security requirements 1026 gap_request_security_level(handle, channel->required_security_level); 1027 } 1028 1029 void l2cap_accept_connection_internal(uint16_t local_cid){ 1030 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1031 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1032 if (!channel) { 1033 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 1034 return; 1035 } 1036 1037 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1038 1039 // process 1040 l2cap_run(); 1041 } 1042 1043 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 1044 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 1045 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1046 if (!channel) { 1047 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 1048 return; 1049 } 1050 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1051 channel->reason = reason; 1052 l2cap_run(); 1053 } 1054 1055 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1056 1057 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1058 1059 uint16_t flags = READ_BT_16(command, 6); 1060 if (flags & 1) { 1061 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1062 } 1063 1064 // accept the other's configuration options 1065 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1066 uint16_t pos = 8; 1067 while (pos < end_pos){ 1068 uint8_t option_hint = command[pos] >> 7; 1069 uint8_t option_type = command[pos] & 0x7f; 1070 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1071 pos++; 1072 uint8_t length = command[pos++]; 1073 // MTU { type(8): 1, len(8):2, MTU(16) } 1074 if (option_type == 1 && length == 2){ 1075 channel->remote_mtu = READ_BT_16(command, pos); 1076 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 1077 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1078 } 1079 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1080 if (option_type == 2 && length == 2){ 1081 channel->flush_timeout = READ_BT_16(command, pos); 1082 } 1083 // check for unknown options 1084 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1085 log_info("l2cap cid %u, unknown options", channel->local_cid); 1086 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1087 } 1088 pos += length; 1089 } 1090 } 1091 1092 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1093 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 1094 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1095 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1096 return 1; 1097 } 1098 1099 1100 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1101 1102 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1103 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1104 uint16_t result = 0; 1105 1106 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 1107 1108 // handle DISCONNECT REQUESTS seperately 1109 if (code == DISCONNECTION_REQUEST){ 1110 switch (channel->state){ 1111 case L2CAP_STATE_CONFIG: 1112 case L2CAP_STATE_OPEN: 1113 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1114 case L2CAP_STATE_WAIT_DISCONNECT: 1115 l2cap_handle_disconnect_request(channel, identifier); 1116 break; 1117 1118 default: 1119 // ignore in other states 1120 break; 1121 } 1122 return; 1123 } 1124 1125 // @STATEMACHINE(l2cap) 1126 switch (channel->state) { 1127 1128 case L2CAP_STATE_WAIT_CONNECT_RSP: 1129 switch (code){ 1130 case CONNECTION_RESPONSE: 1131 l2cap_stop_rtx(channel); 1132 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1133 switch (result) { 1134 case 0: 1135 // successful connection 1136 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1137 channel->state = L2CAP_STATE_CONFIG; 1138 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1139 break; 1140 case 1: 1141 // connection pending. get some coffee, but start the ERTX 1142 l2cap_start_ertx(channel); 1143 break; 1144 default: 1145 // channel closed 1146 channel->state = L2CAP_STATE_CLOSED; 1147 // map l2cap connection response result to BTstack status enumeration 1148 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1149 1150 // drop link key if security block 1151 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1152 hci_drop_link_key_for_bd_addr(&channel->address); 1153 } 1154 1155 // discard channel 1156 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1157 btstack_memory_l2cap_channel_free(channel); 1158 break; 1159 } 1160 break; 1161 1162 default: 1163 //@TODO: implement other signaling packets 1164 break; 1165 } 1166 break; 1167 1168 case L2CAP_STATE_CONFIG: 1169 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1170 switch (code) { 1171 case CONFIGURE_REQUEST: 1172 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1173 l2cap_signaling_handle_configure_request(channel, command); 1174 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1175 // only done if continuation not set 1176 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1177 } 1178 break; 1179 case CONFIGURE_RESPONSE: 1180 l2cap_stop_rtx(channel); 1181 switch (result){ 1182 case 0: // success 1183 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1184 break; 1185 case 4: // pending 1186 l2cap_start_ertx(channel); 1187 break; 1188 default: 1189 // retry on negative result 1190 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1191 break; 1192 } 1193 break; 1194 default: 1195 break; 1196 } 1197 if (l2cap_channel_ready_for_open(channel)){ 1198 // for open: 1199 channel->state = L2CAP_STATE_OPEN; 1200 l2cap_emit_channel_opened(channel, 0); 1201 l2cap_emit_credits(channel, 1); 1202 } 1203 break; 1204 1205 case L2CAP_STATE_WAIT_DISCONNECT: 1206 switch (code) { 1207 case DISCONNECTION_RESPONSE: 1208 l2cap_finialize_channel_close(channel); 1209 break; 1210 default: 1211 //@TODO: implement other signaling packets 1212 break; 1213 } 1214 break; 1215 1216 case L2CAP_STATE_CLOSED: 1217 // @TODO handle incoming requests 1218 break; 1219 1220 case L2CAP_STATE_OPEN: 1221 //@TODO: implement other signaling packets, e.g. re-configure 1222 break; 1223 default: 1224 break; 1225 } 1226 // log_info("new state %u\n", channel->state); 1227 } 1228 1229 1230 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1231 1232 // get code, signalind identifier and command len 1233 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1234 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1235 1236 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1237 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1238 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1239 return; 1240 } 1241 1242 // general commands without an assigned channel 1243 switch(code) { 1244 1245 case CONNECTION_REQUEST: { 1246 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1247 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1248 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1249 return; 1250 } 1251 1252 case ECHO_REQUEST: 1253 l2cap_register_signaling_response(handle, code, sig_id, 0); 1254 return; 1255 1256 case INFORMATION_REQUEST: { 1257 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1258 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1259 return; 1260 } 1261 1262 default: 1263 break; 1264 } 1265 1266 1267 // Get potential destination CID 1268 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1269 1270 // Find channel for this sig_id and connection handle 1271 linked_item_t *it; 1272 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1273 l2cap_channel_t * channel = (l2cap_channel_t *) it; 1274 if (channel->handle == handle) { 1275 if (code & 1) { 1276 // match odd commands (responses) by previous signaling identifier 1277 if (channel->local_sig_id == sig_id) { 1278 l2cap_signaling_handler_channel(channel, command); 1279 break; 1280 } 1281 } else { 1282 // match even commands (requests) by local channel id 1283 if (channel->local_cid == dest_cid) { 1284 l2cap_signaling_handler_channel(channel, command); 1285 break; 1286 } 1287 } 1288 } 1289 } 1290 } 1291 1292 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1293 1294 // Get Channel ID 1295 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1296 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1297 1298 switch (channel_id) { 1299 1300 case L2CAP_CID_SIGNALING: { 1301 1302 uint16_t command_offset = 8; 1303 while (command_offset < size) { 1304 1305 // handle signaling commands 1306 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1307 1308 // increment command_offset 1309 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1310 } 1311 break; 1312 } 1313 1314 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1315 if (attribute_protocol_packet_handler) { 1316 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1317 } 1318 break; 1319 1320 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1321 if (security_protocol_packet_handler) { 1322 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1323 } 1324 break; 1325 1326 case L2CAP_CID_SIGNALING_LE: { 1327 // not implemented yet for LE Peripheral 1328 uint8_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1329 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1330 break; 1331 } 1332 1333 default: { 1334 // Find channel for this channel_id and connection handle 1335 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1336 if (channel) { 1337 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1338 } 1339 break; 1340 } 1341 } 1342 } 1343 1344 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1345 switch (packet_type) { 1346 case HCI_EVENT_PACKET: 1347 l2cap_event_handler(packet, size); 1348 break; 1349 case HCI_ACL_DATA_PACKET: 1350 l2cap_acl_handler(packet, size); 1351 break; 1352 default: 1353 break; 1354 } 1355 l2cap_run(); 1356 } 1357 1358 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1359 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1360 channel->state = L2CAP_STATE_CLOSED; 1361 l2cap_emit_channel_closed(channel); 1362 // discard channel 1363 l2cap_stop_rtx(channel); 1364 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1365 btstack_memory_l2cap_channel_free(channel); 1366 } 1367 1368 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1369 linked_item_t *it; 1370 1371 // close open channels 1372 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 1373 l2cap_service_t * service = ((l2cap_service_t *) it); 1374 if ( service->psm == psm){ 1375 return service; 1376 }; 1377 } 1378 return NULL; 1379 } 1380 1381 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){ 1382 1383 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1384 1385 // check for alread registered psm 1386 // TODO: emit error event 1387 l2cap_service_t *service = l2cap_get_service(psm); 1388 if (service) { 1389 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1390 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1391 return; 1392 } 1393 1394 // alloc structure 1395 // TODO: emit error event 1396 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1397 if (!service) { 1398 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1399 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1400 return; 1401 } 1402 1403 // fill in 1404 service->psm = psm; 1405 service->mtu = mtu; 1406 service->connection = connection; 1407 service->packet_handler = packet_handler; 1408 service->required_security_level = security_level; 1409 1410 // add to services list 1411 linked_list_add(&l2cap_services, (linked_item_t *) service); 1412 1413 // enable page scan 1414 hci_connectable_control(1); 1415 1416 // done 1417 l2cap_emit_service_registered(connection, 0, psm); 1418 } 1419 1420 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1421 1422 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1423 1424 l2cap_service_t *service = l2cap_get_service(psm); 1425 if (!service) return; 1426 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1427 btstack_memory_l2cap_service_free(service); 1428 1429 // disable page scan when no services registered 1430 if (!linked_list_empty(&l2cap_services)) return; 1431 hci_connectable_control(0); 1432 } 1433 1434 // 1435 void l2cap_close_connection(void *connection){ 1436 linked_item_t *it; 1437 1438 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1439 l2cap_channel_t * channel; 1440 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1441 channel = (l2cap_channel_t *) it; 1442 if (channel->connection == connection) { 1443 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1444 } 1445 } 1446 1447 // unregister services 1448 it = (linked_item_t *) &l2cap_services; 1449 while (it->next) { 1450 l2cap_service_t * service = (l2cap_service_t *) it->next; 1451 if (service->connection == connection){ 1452 it->next = it->next->next; 1453 btstack_memory_l2cap_service_free(service); 1454 } else { 1455 it = it->next; 1456 } 1457 } 1458 1459 // process 1460 l2cap_run(); 1461 } 1462 1463 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1464 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1465 switch(channel_id){ 1466 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1467 attribute_protocol_packet_handler = packet_handler; 1468 break; 1469 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1470 security_protocol_packet_handler = packet_handler; 1471 break; 1472 } 1473 } 1474 1475 #ifdef HAVE_BLE 1476 // Request LE connection parameter update 1477 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){ 1478 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 1479 log_info("l2cap_send_signaling_packet, cannot send\n"); 1480 return BTSTACK_ACL_BUFFERS_FULL; 1481 } 1482 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1483 hci_reserve_packet_buffer(); 1484 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1485 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1486 return hci_send_acl_packet_buffer(len); 1487 } 1488 #endif 1489 1490