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(HCI_ACL_DATA_PACKET); 236 } 237 238 int l2cap_can_send_packet_now_using_buffer(uint16_t local_cid){ 239 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 240 if (!channel) return 0; 241 if (!channel->packets_granted) return 0; 242 return hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET); 243 } 244 245 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 246 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 247 if (channel) { 248 return channel->remote_mtu; 249 } 250 return 0; 251 } 252 253 static l2cap_channel_t * l2cap_channel_for_rtx_timer(timer_source_t * ts){ 254 linked_item_t *it; 255 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 256 l2cap_channel_t * channel = (l2cap_channel_t *) it; 257 if ( &channel->rtx == ts) { 258 return channel; 259 } 260 } 261 return NULL; 262 } 263 264 static void l2cap_rtx_timeout(timer_source_t * ts){ 265 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 266 if (!ts) return; 267 268 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 269 270 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 271 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 272 // notify client 273 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 274 275 // discard channel 276 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 277 btstack_memory_l2cap_channel_free(channel); 278 } 279 280 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 281 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 282 run_loop_remove_timer(&channel->rtx); 283 } 284 285 static void l2cap_start_rtx(l2cap_channel_t * channel){ 286 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 287 l2cap_stop_rtx(channel); 288 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 289 run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 290 run_loop_add_timer(&channel->rtx); 291 } 292 293 static void l2cap_start_ertx(l2cap_channel_t * channel){ 294 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 295 l2cap_stop_rtx(channel); 296 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 297 run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 298 run_loop_add_timer(&channel->rtx); 299 } 300 301 void l2cap_require_security_level_2_for_outgoing_sdp(){ 302 require_security_level2_for_outgoing_sdp = 1; 303 } 304 305 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 306 return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); 307 } 308 309 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 310 311 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 312 log_info("l2cap_send_signaling_packet, cannot send\n"); 313 return BTSTACK_ACL_BUFFERS_FULL; 314 } 315 316 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 317 hci_reserve_packet_buffer(); 318 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 319 va_list argptr; 320 va_start(argptr, identifier); 321 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 322 va_end(argptr); 323 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 324 return hci_send_acl_packet(acl_buffer, len); 325 } 326 327 #ifdef HAVE_BLE 328 int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 329 330 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 331 log_info("l2cap_send_signaling_packet, cannot send\n"); 332 return BTSTACK_ACL_BUFFERS_FULL; 333 } 334 335 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 336 hci_reserve_packet_buffer(); 337 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 338 va_list argptr; 339 va_start(argptr, identifier); 340 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 341 va_end(argptr); 342 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 343 return hci_send_acl_packet(acl_buffer, len); 344 } 345 #endif 346 347 uint8_t *l2cap_get_outgoing_buffer(void){ 348 return hci_get_outgoing_acl_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 349 } 350 351 int l2cap_reserve_packet_buffer(void){ 352 return hci_reserve_packet_buffer(); 353 } 354 355 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 356 357 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 358 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 359 return BTSTACK_ACL_BUFFERS_FULL; 360 } 361 362 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 363 if (!channel) { 364 log_error("l2cap_send_internal no channel for cid 0x%02x\n", local_cid); 365 return -1; // TODO: define error 366 } 367 368 if (channel->packets_granted == 0){ 369 log_error("l2cap_send_internal cid 0x%02x, no credits!\n", local_cid); 370 return -1; // TODO: define error 371 } 372 373 --channel->packets_granted; 374 375 log_debug("l2cap_send_internal cid 0x%02x, handle %u, 1 credit used, credits left %u;\n", 376 local_cid, channel->handle, channel->packets_granted); 377 378 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 379 380 // 0 - Connection handle : PB=10 : BC=00 381 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 382 // 2 - ACL length 383 bt_store_16(acl_buffer, 2, len + 4); 384 // 4 - L2CAP packet length 385 bt_store_16(acl_buffer, 4, len + 0); 386 // 6 - L2CAP channel DEST 387 bt_store_16(acl_buffer, 6, channel->remote_cid); 388 // send 389 int err = hci_send_acl_packet(acl_buffer, len+8); 390 391 l2cap_hand_out_credits(); 392 393 return err; 394 } 395 396 int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len){ 397 398 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 399 log_info("l2cap_send_prepared_to_handle cid 0x%02x, cannot send\n", cid); 400 return BTSTACK_ACL_BUFFERS_FULL; 401 } 402 403 log_debug("l2cap_send_prepared_to_handle cid 0x%02x, handle %u\n", cid, handle); 404 405 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 406 407 // 0 - Connection handle : PB=10 : BC=00 408 bt_store_16(acl_buffer, 0, handle | (2 << 12) | (0 << 14)); 409 // 2 - ACL length 410 bt_store_16(acl_buffer, 2, len + 4); 411 // 4 - L2CAP packet length 412 bt_store_16(acl_buffer, 4, len + 0); 413 // 6 - L2CAP channel DEST 414 bt_store_16(acl_buffer, 6, cid); 415 // send 416 int err = hci_send_acl_packet(acl_buffer, len+8); 417 418 l2cap_hand_out_credits(); 419 420 return err; 421 } 422 423 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 424 425 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 426 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 427 return BTSTACK_ACL_BUFFERS_FULL; 428 } 429 430 hci_reserve_packet_buffer(); 431 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 432 433 memcpy(&acl_buffer[8], data, len); 434 435 return l2cap_send_prepared(local_cid, len); 436 } 437 438 int l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len){ 439 440 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 441 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", cid); 442 return BTSTACK_ACL_BUFFERS_FULL; 443 } 444 445 hci_reserve_packet_buffer(); 446 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 447 448 memcpy(&acl_buffer[8], data, len); 449 450 return l2cap_send_prepared_connectionless(handle, cid, len); 451 } 452 453 int l2cap_send_echo_request(uint16_t handle, uint8_t *data, uint16_t len){ 454 return l2cap_send_signaling_packet(handle, ECHO_REQUEST, 0x77, len, data); 455 } 456 457 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 458 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 459 } 460 461 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 462 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 463 } 464 465 466 467 // MARK: L2CAP_RUN 468 // process outstanding signaling tasks 469 void l2cap_run(void){ 470 471 // check pending signaling responses 472 while (signaling_responses_pending){ 473 474 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)) break; 475 476 hci_con_handle_t handle = signaling_responses[0].handle; 477 uint8_t sig_id = signaling_responses[0].sig_id; 478 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 479 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 480 481 switch (signaling_responses[0].code){ 482 case CONNECTION_REQUEST: 483 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 484 // also disconnect if result is 0x0003 - security blocked 485 hci_disconnect_security_block(handle); 486 break; 487 case ECHO_REQUEST: 488 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 489 break; 490 case INFORMATION_REQUEST: 491 switch (infoType){ 492 case 1: { // Connectionless MTU 493 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 494 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 495 break; 496 } 497 case 2: { // Extended Features Supported 498 // extended features request supported, only supporing fixed channel map 499 uint32_t features = 0x80; 500 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 501 break; 502 } 503 case 3: { // Fixed Channels Supported 504 uint8_t map[8]; 505 memset(map, 0, 8); 506 map[0] = 0x01; // L2CAP Signaling Channel 507 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 508 break; 509 } 510 default: 511 // all other types are not supported 512 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 513 break; 514 } 515 break; 516 case COMMAND_REJECT: 517 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 518 #ifdef HAVE_BLE 519 case COMMAND_REJECT_LE: 520 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 521 break; 522 #endif 523 default: 524 // should not happen 525 break; 526 } 527 528 // remove first item 529 signaling_responses_pending--; 530 int i; 531 for (i=0; i < signaling_responses_pending; i++){ 532 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 533 } 534 } 535 536 uint8_t config_options[4]; 537 linked_item_t *it; 538 linked_item_t *next; 539 for (it = (linked_item_t *) l2cap_channels; it ; it = next){ 540 next = it->next; // cache next item as current item might get freed 541 542 if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) break; 543 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)) break; 544 545 l2cap_channel_t * channel = (l2cap_channel_t *) it; 546 547 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 548 549 550 switch (channel->state){ 551 552 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 553 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 554 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 555 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 556 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 557 } 558 break; 559 560 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 561 // send connection request - set state first 562 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 563 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 564 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 565 break; 566 567 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 568 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 569 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 570 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); // -- remove from list 571 btstack_memory_l2cap_channel_free(channel); 572 break; 573 574 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 575 channel->state = L2CAP_STATE_CONFIG; 576 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 577 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 578 break; 579 580 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 581 // success, start l2cap handshake 582 channel->local_sig_id = l2cap_next_sig_id(); 583 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 584 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 585 l2cap_start_rtx(channel); 586 break; 587 588 case L2CAP_STATE_CONFIG: 589 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 590 uint16_t flags = 0; 591 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 592 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 593 flags = 1; 594 } else { 595 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 596 } 597 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 598 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 599 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 600 config_options[0] = 1; // MTU 601 config_options[1] = 2; // len param 602 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 603 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 604 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 605 } else { 606 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 607 } 608 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 609 } 610 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 611 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 612 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 613 channel->local_sig_id = l2cap_next_sig_id(); 614 config_options[0] = 1; // MTU 615 config_options[1] = 2; // len param 616 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 617 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 618 l2cap_start_rtx(channel); 619 } 620 if (l2cap_channel_ready_for_open(channel)){ 621 channel->state = L2CAP_STATE_OPEN; 622 l2cap_emit_channel_opened(channel, 0); // success 623 l2cap_emit_credits(channel, 1); 624 } 625 break; 626 627 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 628 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 629 // 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 :) 630 l2cap_finialize_channel_close(channel); // -- remove from list 631 break; 632 633 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 634 channel->local_sig_id = l2cap_next_sig_id(); 635 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 636 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 637 break; 638 default: 639 break; 640 } 641 } 642 } 643 644 uint16_t l2cap_max_mtu(void){ 645 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 646 } 647 648 static void l2cap_handle_connection_complete(uint16_t handle, l2cap_channel_t * channel){ 649 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 650 log_info("l2cap_handle_connection_complete expected state"); 651 // success, start l2cap handshake 652 channel->handle = handle; 653 channel->local_cid = l2cap_next_local_cid(); 654 // check remote SSP feature first 655 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 656 } 657 } 658 659 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 660 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 661 662 // we have been waiting for remote supported features, if both support SSP, 663 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)); 664 if (hci_ssp_supported_on_both_sides(channel->handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 665 // request security level 2 666 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 667 gap_request_security_level(channel->handle, LEVEL_2); 668 return; 669 } 670 // fine, go ahead 671 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 672 } 673 674 // open outgoing L2CAP channel 675 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 676 bd_addr_t address, uint16_t psm, uint16_t mtu){ 677 678 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 679 680 // alloc structure 681 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 682 if (!chan) { 683 // emit error event 684 l2cap_channel_t dummy_channel; 685 BD_ADDR_COPY(dummy_channel.address, address); 686 dummy_channel.psm = psm; 687 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 688 return; 689 } 690 // limit local mtu to max acl packet length 691 if (mtu > l2cap_max_mtu()) { 692 mtu = l2cap_max_mtu(); 693 } 694 695 // fill in 696 BD_ADDR_COPY(chan->address, address); 697 chan->psm = psm; 698 chan->handle = 0; 699 chan->connection = connection; 700 chan->packet_handler = packet_handler; 701 chan->remote_mtu = L2CAP_MINIMAL_MTU; 702 chan->local_mtu = mtu; 703 chan->packets_granted = 0; 704 705 // set initial state 706 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 707 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 708 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 709 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 710 chan->required_security_level = LEVEL_0; 711 712 // add to connections list 713 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 714 715 // check if hci connection is already usable 716 hci_connection_t * conn = hci_connection_for_bd_addr((bd_addr_t*)address); 717 if (conn){ 718 log_info("l2cap_create_channel_internal, hci connection already exists"); 719 l2cap_handle_connection_complete(conn->con_handle, chan); 720 // check ir remote supported fearures are already received 721 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 722 l2cap_handle_remote_supported_features_received(chan); 723 } 724 } 725 726 l2cap_run(); 727 } 728 729 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 730 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 731 // find channel for local_cid 732 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 733 if (channel) { 734 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 735 } 736 // process 737 l2cap_run(); 738 } 739 740 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 741 linked_item_t *it = (linked_item_t *) &l2cap_channels; 742 while (it->next){ 743 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 744 if ( ! BD_ADDR_CMP( channel->address, address) ){ 745 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 746 // failure, forward error code 747 l2cap_emit_channel_opened(channel, status); 748 // discard channel 749 it->next = it->next->next; 750 btstack_memory_l2cap_channel_free(channel); 751 } 752 } else { 753 it = it->next; 754 } 755 } 756 } 757 758 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 759 linked_item_t *it; 760 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 761 l2cap_channel_t * channel = (l2cap_channel_t *) it; 762 if ( ! BD_ADDR_CMP( channel->address, address) ){ 763 l2cap_handle_connection_complete(handle, channel); 764 } 765 } 766 // process 767 l2cap_run(); 768 } 769 770 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 771 772 bd_addr_t address; 773 hci_con_handle_t handle; 774 l2cap_channel_t * channel; 775 linked_item_t *it; 776 int hci_con_used; 777 778 switch(packet[0]){ 779 780 // handle connection complete events 781 case HCI_EVENT_CONNECTION_COMPLETE: 782 bt_flip_addr(address, &packet[5]); 783 if (packet[2] == 0){ 784 handle = READ_BT_16(packet, 3); 785 l2cap_handle_connection_success_for_addr(address, handle); 786 } else { 787 l2cap_handle_connection_failed_for_addr(address, packet[2]); 788 } 789 break; 790 791 // handle successful create connection cancel command 792 case HCI_EVENT_COMMAND_COMPLETE: 793 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 794 if (packet[5] == 0){ 795 bt_flip_addr(address, &packet[6]); 796 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 797 l2cap_handle_connection_failed_for_addr(address, 0x16); 798 } 799 } 800 l2cap_run(); // try sending signaling packets first 801 break; 802 803 case HCI_EVENT_COMMAND_STATUS: 804 l2cap_run(); // try sending signaling packets first 805 break; 806 807 // handle disconnection complete events 808 case HCI_EVENT_DISCONNECTION_COMPLETE: 809 // send l2cap disconnect events for all channels on this handle 810 handle = READ_BT_16(packet, 3); 811 it = (linked_item_t *) &l2cap_channels; 812 while (it->next){ 813 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 814 if ( channel->handle == handle ){ 815 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 816 it->next = it->next->next; 817 l2cap_emit_channel_closed(channel); 818 btstack_memory_l2cap_channel_free(channel); 819 } else { 820 it = it->next; 821 } 822 } 823 break; 824 825 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 826 l2cap_run(); // try sending signaling packets first 827 l2cap_hand_out_credits(); 828 break; 829 830 // HCI Connection Timeouts 831 case L2CAP_EVENT_TIMEOUT_CHECK: 832 handle = READ_BT_16(packet, 2); 833 if (hci_authentication_active_for_handle(handle)) break; 834 hci_con_used = 0; 835 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 836 channel = (l2cap_channel_t *) it; 837 if (channel->handle == handle) { 838 hci_con_used = 1; 839 } 840 } 841 if (hci_con_used) break; 842 if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) break; 843 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 844 break; 845 846 case DAEMON_EVENT_HCI_PACKET_SENT: 847 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 848 channel = (l2cap_channel_t *) it; 849 if (channel->packet_handler) { 850 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 851 } 852 } 853 if (attribute_protocol_packet_handler) { 854 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 855 } 856 if (security_protocol_packet_handler) { 857 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 858 } 859 break; 860 861 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 862 handle = READ_BT_16(packet, 3); 863 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 864 channel = (l2cap_channel_t *) it; 865 if (channel->handle != handle) continue; 866 l2cap_handle_remote_supported_features_received(channel); 867 break; 868 } 869 870 case GAP_SECURITY_LEVEL: 871 handle = READ_BT_16(packet, 2); 872 log_info("l2cap - security level update"); 873 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 874 channel = (l2cap_channel_t *) it; 875 if (channel->handle != handle) continue; 876 877 log_info("l2cap - state %u", channel->state); 878 879 gap_security_level_t actual_level = packet[4]; 880 gap_security_level_t required_level = channel->required_security_level; 881 882 switch (channel->state){ 883 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 884 if (actual_level >= required_level){ 885 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 886 l2cap_emit_connection_request(channel); 887 } else { 888 channel->reason = 0x03; // security block 889 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 890 } 891 break; 892 893 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 894 if (actual_level >= required_level){ 895 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 896 } else { 897 // disconnnect, authentication not good enough 898 hci_disconnect_security_block(handle); 899 } 900 break; 901 902 default: 903 break; 904 } 905 } 906 break; 907 908 default: 909 break; 910 } 911 912 // pass on 913 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 914 915 l2cap_run(); 916 } 917 918 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 919 channel->remote_sig_id = identifier; 920 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 921 l2cap_run(); 922 } 923 924 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 925 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 926 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 927 signaling_responses[signaling_responses_pending].handle = handle; 928 signaling_responses[signaling_responses_pending].code = code; 929 signaling_responses[signaling_responses_pending].sig_id = sig_id; 930 signaling_responses[signaling_responses_pending].data = data; 931 signaling_responses_pending++; 932 l2cap_run(); 933 } 934 } 935 936 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 937 938 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 939 l2cap_service_t *service = l2cap_get_service(psm); 940 if (!service) { 941 // 0x0002 PSM not supported 942 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 943 return; 944 } 945 946 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 947 if (!hci_connection) { 948 // 949 log_error("no hci_connection for handle %u\n", handle); 950 return; 951 } 952 953 // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP 954 if ( hci_ssp_supported_on_both_sides(handle) 955 && gap_security_level(handle) == LEVEL_0 956 && !l2cap_security_level_0_allowed_for_PSM(psm)){ 957 958 // 0x0003 Security Block 959 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); 960 return; 961 } 962 963 964 // alloc structure 965 // log_info("l2cap_handle_connection_request register channel\n"); 966 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 967 if (!channel){ 968 // 0x0004 No resources available 969 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 970 return; 971 } 972 973 // fill in 974 BD_ADDR_COPY(channel->address, hci_connection->address); 975 channel->psm = psm; 976 channel->handle = handle; 977 channel->connection = service->connection; 978 channel->packet_handler = service->packet_handler; 979 channel->local_cid = l2cap_next_local_cid(); 980 channel->remote_cid = source_cid; 981 channel->local_mtu = service->mtu; 982 channel->remote_mtu = L2CAP_DEFAULT_MTU; 983 channel->packets_granted = 0; 984 channel->remote_sig_id = sig_id; 985 channel->required_security_level = service->required_security_level; 986 987 // limit local mtu to max acl packet length 988 if (channel->local_mtu > l2cap_max_mtu()) { 989 channel->local_mtu = l2cap_max_mtu(); 990 } 991 992 // set initial state 993 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 994 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 995 996 // add to connections list 997 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 998 999 // assert security requirements 1000 gap_request_security_level(handle, channel->required_security_level); 1001 } 1002 1003 void l2cap_accept_connection_internal(uint16_t local_cid){ 1004 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1005 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1006 if (!channel) { 1007 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 1008 return; 1009 } 1010 1011 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1012 1013 // process 1014 l2cap_run(); 1015 } 1016 1017 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 1018 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 1019 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1020 if (!channel) { 1021 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 1022 return; 1023 } 1024 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1025 channel->reason = reason; 1026 l2cap_run(); 1027 } 1028 1029 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1030 1031 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1032 1033 uint16_t flags = READ_BT_16(command, 6); 1034 if (flags & 1) { 1035 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1036 } 1037 1038 // accept the other's configuration options 1039 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1040 uint16_t pos = 8; 1041 while (pos < end_pos){ 1042 uint8_t option_hint = command[pos] >> 7; 1043 uint8_t option_type = command[pos] & 0x7f; 1044 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1045 pos++; 1046 uint8_t length = command[pos++]; 1047 // MTU { type(8): 1, len(8):2, MTU(16) } 1048 if (option_type == 1 && length == 2){ 1049 channel->remote_mtu = READ_BT_16(command, pos); 1050 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 1051 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1052 } 1053 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1054 if (option_type == 2 && length == 2){ 1055 channel->flush_timeout = READ_BT_16(command, pos); 1056 } 1057 // check for unknown options 1058 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1059 log_info("l2cap cid %u, unknown options", channel->local_cid); 1060 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1061 } 1062 pos += length; 1063 } 1064 } 1065 1066 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1067 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 1068 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1069 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1070 return 1; 1071 } 1072 1073 1074 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1075 1076 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1077 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1078 uint16_t result = 0; 1079 1080 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 1081 1082 // handle DISCONNECT REQUESTS seperately 1083 if (code == DISCONNECTION_REQUEST){ 1084 switch (channel->state){ 1085 case L2CAP_STATE_CONFIG: 1086 case L2CAP_STATE_OPEN: 1087 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1088 case L2CAP_STATE_WAIT_DISCONNECT: 1089 l2cap_handle_disconnect_request(channel, identifier); 1090 break; 1091 1092 default: 1093 // ignore in other states 1094 break; 1095 } 1096 return; 1097 } 1098 1099 // @STATEMACHINE(l2cap) 1100 switch (channel->state) { 1101 1102 case L2CAP_STATE_WAIT_CONNECT_RSP: 1103 switch (code){ 1104 case CONNECTION_RESPONSE: 1105 l2cap_stop_rtx(channel); 1106 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1107 switch (result) { 1108 case 0: 1109 // successful connection 1110 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1111 channel->state = L2CAP_STATE_CONFIG; 1112 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1113 break; 1114 case 1: 1115 // connection pending. get some coffee, but start the ERTX 1116 l2cap_start_ertx(channel); 1117 break; 1118 default: 1119 // channel closed 1120 channel->state = L2CAP_STATE_CLOSED; 1121 // map l2cap connection response result to BTstack status enumeration 1122 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1123 1124 // drop link key if security block 1125 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1126 hci_drop_link_key_for_bd_addr(&channel->address); 1127 } 1128 1129 // discard channel 1130 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1131 btstack_memory_l2cap_channel_free(channel); 1132 break; 1133 } 1134 break; 1135 1136 default: 1137 //@TODO: implement other signaling packets 1138 break; 1139 } 1140 break; 1141 1142 case L2CAP_STATE_CONFIG: 1143 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1144 switch (code) { 1145 case CONFIGURE_REQUEST: 1146 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1147 l2cap_signaling_handle_configure_request(channel, command); 1148 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1149 // only done if continuation not set 1150 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1151 } 1152 break; 1153 case CONFIGURE_RESPONSE: 1154 l2cap_stop_rtx(channel); 1155 switch (result){ 1156 case 0: // success 1157 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1158 break; 1159 case 4: // pending 1160 l2cap_start_ertx(channel); 1161 break; 1162 default: 1163 // retry on negative result 1164 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1165 break; 1166 } 1167 break; 1168 default: 1169 break; 1170 } 1171 if (l2cap_channel_ready_for_open(channel)){ 1172 // for open: 1173 channel->state = L2CAP_STATE_OPEN; 1174 l2cap_emit_channel_opened(channel, 0); 1175 l2cap_emit_credits(channel, 1); 1176 } 1177 break; 1178 1179 case L2CAP_STATE_WAIT_DISCONNECT: 1180 switch (code) { 1181 case DISCONNECTION_RESPONSE: 1182 l2cap_finialize_channel_close(channel); 1183 break; 1184 default: 1185 //@TODO: implement other signaling packets 1186 break; 1187 } 1188 break; 1189 1190 case L2CAP_STATE_CLOSED: 1191 // @TODO handle incoming requests 1192 break; 1193 1194 case L2CAP_STATE_OPEN: 1195 //@TODO: implement other signaling packets, e.g. re-configure 1196 break; 1197 default: 1198 break; 1199 } 1200 // log_info("new state %u\n", channel->state); 1201 } 1202 1203 1204 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1205 1206 // get code, signalind identifier and command len 1207 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1208 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1209 1210 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1211 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1212 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1213 return; 1214 } 1215 1216 // general commands without an assigned channel 1217 switch(code) { 1218 1219 case CONNECTION_REQUEST: { 1220 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1221 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1222 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1223 return; 1224 } 1225 1226 case ECHO_REQUEST: 1227 l2cap_register_signaling_response(handle, code, sig_id, 0); 1228 return; 1229 1230 case INFORMATION_REQUEST: { 1231 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1232 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1233 return; 1234 } 1235 1236 default: 1237 break; 1238 } 1239 1240 1241 // Get potential destination CID 1242 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1243 1244 // Find channel for this sig_id and connection handle 1245 linked_item_t *it; 1246 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1247 l2cap_channel_t * channel = (l2cap_channel_t *) it; 1248 if (channel->handle == handle) { 1249 if (code & 1) { 1250 // match odd commands (responses) by previous signaling identifier 1251 if (channel->local_sig_id == sig_id) { 1252 l2cap_signaling_handler_channel(channel, command); 1253 break; 1254 } 1255 } else { 1256 // match even commands (requests) by local channel id 1257 if (channel->local_cid == dest_cid) { 1258 l2cap_signaling_handler_channel(channel, command); 1259 break; 1260 } 1261 } 1262 } 1263 } 1264 } 1265 1266 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1267 1268 // Get Channel ID 1269 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1270 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1271 1272 switch (channel_id) { 1273 1274 case L2CAP_CID_SIGNALING: { 1275 1276 uint16_t command_offset = 8; 1277 while (command_offset < size) { 1278 1279 // handle signaling commands 1280 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1281 1282 // increment command_offset 1283 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1284 } 1285 break; 1286 } 1287 1288 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1289 if (attribute_protocol_packet_handler) { 1290 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1291 } 1292 break; 1293 1294 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1295 if (security_protocol_packet_handler) { 1296 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1297 } 1298 break; 1299 1300 case L2CAP_CID_SIGNALING_LE: { 1301 // not implemented yet for LE Peripheral 1302 uint8_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1303 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1304 break; 1305 } 1306 1307 default: { 1308 // Find channel for this channel_id and connection handle 1309 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1310 if (channel) { 1311 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1312 } 1313 break; 1314 } 1315 } 1316 } 1317 1318 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1319 switch (packet_type) { 1320 case HCI_EVENT_PACKET: 1321 l2cap_event_handler(packet, size); 1322 break; 1323 case HCI_ACL_DATA_PACKET: 1324 l2cap_acl_handler(packet, size); 1325 break; 1326 default: 1327 break; 1328 } 1329 l2cap_run(); 1330 } 1331 1332 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1333 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1334 channel->state = L2CAP_STATE_CLOSED; 1335 l2cap_emit_channel_closed(channel); 1336 // discard channel 1337 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1338 btstack_memory_l2cap_channel_free(channel); 1339 } 1340 1341 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1342 linked_item_t *it; 1343 1344 // close open channels 1345 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 1346 l2cap_service_t * service = ((l2cap_service_t *) it); 1347 if ( service->psm == psm){ 1348 return service; 1349 }; 1350 } 1351 return NULL; 1352 } 1353 1354 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){ 1355 1356 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1357 1358 // check for alread registered psm 1359 // TODO: emit error event 1360 l2cap_service_t *service = l2cap_get_service(psm); 1361 if (service) { 1362 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1363 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1364 return; 1365 } 1366 1367 // alloc structure 1368 // TODO: emit error event 1369 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1370 if (!service) { 1371 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1372 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1373 return; 1374 } 1375 1376 // fill in 1377 service->psm = psm; 1378 service->mtu = mtu; 1379 service->connection = connection; 1380 service->packet_handler = packet_handler; 1381 service->required_security_level = security_level; 1382 1383 // add to services list 1384 linked_list_add(&l2cap_services, (linked_item_t *) service); 1385 1386 // enable page scan 1387 hci_connectable_control(1); 1388 1389 // done 1390 l2cap_emit_service_registered(connection, 0, psm); 1391 } 1392 1393 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1394 1395 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1396 1397 l2cap_service_t *service = l2cap_get_service(psm); 1398 if (!service) return; 1399 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1400 btstack_memory_l2cap_service_free(service); 1401 1402 // disable page scan when no services registered 1403 if (!linked_list_empty(&l2cap_services)) return; 1404 hci_connectable_control(0); 1405 } 1406 1407 // 1408 void l2cap_close_connection(void *connection){ 1409 linked_item_t *it; 1410 1411 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1412 l2cap_channel_t * channel; 1413 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1414 channel = (l2cap_channel_t *) it; 1415 if (channel->connection == connection) { 1416 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1417 } 1418 } 1419 1420 // unregister services 1421 it = (linked_item_t *) &l2cap_services; 1422 while (it->next) { 1423 l2cap_service_t * service = (l2cap_service_t *) it->next; 1424 if (service->connection == connection){ 1425 it->next = it->next->next; 1426 btstack_memory_l2cap_service_free(service); 1427 } else { 1428 it = it->next; 1429 } 1430 } 1431 1432 // process 1433 l2cap_run(); 1434 } 1435 1436 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1437 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1438 switch(channel_id){ 1439 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1440 attribute_protocol_packet_handler = packet_handler; 1441 break; 1442 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1443 security_protocol_packet_handler = packet_handler; 1444 break; 1445 } 1446 } 1447 1448 #ifdef HAVE_BLE 1449 // Request LE connection parameter update 1450 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){ 1451 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 1452 log_info("l2cap_send_signaling_packet, cannot send\n"); 1453 return BTSTACK_ACL_BUFFERS_FULL; 1454 } 1455 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1456 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 1457 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1458 return hci_send_acl_packet(acl_buffer, len); 1459 } 1460 #endif 1461 1462