1 /* 2 * Copyright (C) 2009-2012 by Matthias Ringwald 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY MATTHIAS RINGWALD AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at [email protected] 34 * 35 */ 36 37 /* 38 * l2cap.c 39 * 40 * Logical Link Control and Adaption Protocl (L2CAP) 41 * 42 * Created by Matthias Ringwald on 5/16/09. 43 */ 44 45 #include "l2cap.h" 46 #include "hci.h" 47 #include "hci_dump.h" 48 #include "debug.h" 49 #include "btstack_memory.h" 50 51 #include <stdarg.h> 52 #include <string.h> 53 54 #include <stdio.h> 55 56 // nr of buffered acl packets in outgoing queue to get max performance 57 #define NR_BUFFERED_ACL_PACKETS 3 58 59 // used to cache l2cap rejects, echo, and informational requests 60 #define NR_PENDING_SIGNALING_RESPONSES 3 61 62 // offsets for L2CAP SIGNALING COMMANDS 63 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 64 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 65 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 66 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 67 68 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 69 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size); 70 71 // used to cache l2cap rejects, echo, and informational requests 72 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 73 static int signaling_responses_pending; 74 75 static linked_list_t l2cap_channels; 76 static linked_list_t l2cap_services; 77 static void (*packet_handler) (void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) = null_packet_handler; 78 static int new_credits_blocked = 0; 79 80 static btstack_packet_handler_t attribute_protocol_packet_handler; 81 static btstack_packet_handler_t security_protocol_packet_handler; 82 static uint8_t require_security_level2_for_outgoing_sdp; 83 84 // prototypes 85 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 86 static l2cap_service_t * l2cap_get_service(uint16_t psm); 87 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 88 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 89 static void l2cap_emit_connection_request(l2cap_channel_t *channel); 90 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 91 92 93 void l2cap_init(){ 94 new_credits_blocked = 0; 95 signaling_responses_pending = 0; 96 97 l2cap_channels = NULL; 98 l2cap_services = NULL; 99 100 packet_handler = null_packet_handler; 101 attribute_protocol_packet_handler = NULL; 102 security_protocol_packet_handler = NULL; 103 104 require_security_level2_for_outgoing_sdp = 0; 105 106 // 107 // register callback with HCI 108 // 109 hci_register_packet_handler(&l2cap_packet_handler); 110 hci_connectable_control(0); // no services yet 111 } 112 113 114 /** Register L2CAP packet handlers */ 115 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 116 } 117 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 118 packet_handler = handler; 119 } 120 121 // notify client/protocol handler 122 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 123 if (channel->packet_handler) { 124 (* (channel->packet_handler))(type, channel->local_cid, data, size); 125 } else { 126 (*packet_handler)(channel->connection, type, channel->local_cid, data, size); 127 } 128 } 129 130 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 131 log_info("L2CAP_EVENT_CHANNEL_OPENED status 0x%x addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x local_mtu %u, remote_mtu %u, flush_timeout %u", 132 status, bd_addr_to_str(channel->address), channel->handle, channel->psm, 133 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 134 uint8_t event[23]; 135 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 136 event[1] = sizeof(event) - 2; 137 event[2] = status; 138 bt_flip_addr(&event[3], channel->address); 139 bt_store_16(event, 9, channel->handle); 140 bt_store_16(event, 11, channel->psm); 141 bt_store_16(event, 13, channel->local_cid); 142 bt_store_16(event, 15, channel->remote_cid); 143 bt_store_16(event, 17, channel->local_mtu); 144 bt_store_16(event, 19, channel->remote_mtu); 145 bt_store_16(event, 19, channel->flush_timeout); 146 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 147 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 148 } 149 150 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 151 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 152 uint8_t event[4]; 153 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 154 event[1] = sizeof(event) - 2; 155 bt_store_16(event, 2, channel->local_cid); 156 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 157 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 158 } 159 160 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 161 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 162 bd_addr_to_str(channel->address), channel->handle, channel->psm, channel->local_cid, channel->remote_cid); 163 uint8_t event[16]; 164 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 165 event[1] = sizeof(event) - 2; 166 bt_flip_addr(&event[2], channel->address); 167 bt_store_16(event, 8, channel->handle); 168 bt_store_16(event, 10, channel->psm); 169 bt_store_16(event, 12, channel->local_cid); 170 bt_store_16(event, 14, channel->remote_cid); 171 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 172 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 173 } 174 175 static void l2cap_emit_service_registered(void *connection, uint8_t status, uint16_t psm){ 176 log_info("L2CAP_EVENT_SERVICE_REGISTERED status 0x%x psm 0x%x", status, psm); 177 uint8_t event[5]; 178 event[0] = L2CAP_EVENT_SERVICE_REGISTERED; 179 event[1] = sizeof(event) - 2; 180 event[2] = status; 181 bt_store_16(event, 3, psm); 182 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 183 (*packet_handler)(connection, HCI_EVENT_PACKET, 0, event, sizeof(event)); 184 } 185 186 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 187 188 log_info("L2CAP_EVENT_CREDITS local_cid 0x%x credits %u", channel->local_cid, credits); 189 // track credits 190 channel->packets_granted += credits; 191 192 uint8_t event[5]; 193 event[0] = L2CAP_EVENT_CREDITS; 194 event[1] = sizeof(event) - 2; 195 bt_store_16(event, 2, channel->local_cid); 196 event[4] = credits; 197 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 198 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 199 } 200 201 void l2cap_block_new_credits(uint8_t blocked){ 202 new_credits_blocked = blocked; 203 } 204 205 void l2cap_hand_out_credits(void){ 206 207 if (new_credits_blocked) return; // we're told not to. used by daemon 208 209 linked_item_t *it; 210 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 211 if (!hci_number_free_acl_slots()) return; 212 l2cap_channel_t * channel = (l2cap_channel_t *) it; 213 if (channel->state != L2CAP_STATE_OPEN) continue; 214 if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { 215 l2cap_emit_credits(channel, 1); 216 } 217 } 218 } 219 220 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 221 linked_item_t *it; 222 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 223 l2cap_channel_t * channel = (l2cap_channel_t *) it; 224 if ( channel->local_cid == local_cid) { 225 return channel; 226 } 227 } 228 return NULL; 229 } 230 231 int l2cap_can_send_packet_now(uint16_t local_cid){ 232 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 233 if (!channel) return 0; 234 if (!channel->packets_granted) return 0; 235 return hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET); 236 } 237 238 int l2cap_can_send_connectionless_packet_now(void){ 239 return hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET); 240 } 241 242 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 243 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 244 if (channel) { 245 return channel->remote_mtu; 246 } 247 return 0; 248 } 249 250 static l2cap_channel_t * l2cap_channel_for_rtx_timer(timer_source_t * ts){ 251 linked_item_t *it; 252 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 253 l2cap_channel_t * channel = (l2cap_channel_t *) it; 254 if ( &channel->rtx == ts) { 255 return channel; 256 } 257 } 258 return NULL; 259 } 260 261 static void l2cap_rtx_timeout(timer_source_t * ts){ 262 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 263 if (!ts) return; 264 265 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 266 267 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 268 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 269 // notify client 270 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 271 272 // discard channel 273 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 274 btstack_memory_l2cap_channel_free(channel); 275 } 276 277 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 278 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 279 run_loop_remove_timer(&channel->rtx); 280 } 281 282 static void l2cap_start_rtx(l2cap_channel_t * channel){ 283 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 284 l2cap_stop_rtx(channel); 285 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 286 run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 287 run_loop_add_timer(&channel->rtx); 288 } 289 290 static void l2cap_start_ertx(l2cap_channel_t * channel){ 291 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 292 l2cap_stop_rtx(channel); 293 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 294 run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 295 run_loop_add_timer(&channel->rtx); 296 } 297 298 void l2cap_require_security_level_2_for_outgoing_sdp(){ 299 require_security_level2_for_outgoing_sdp = 1; 300 } 301 302 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 303 return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); 304 } 305 306 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 307 308 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 309 log_info("l2cap_send_signaling_packet, cannot send\n"); 310 return BTSTACK_ACL_BUFFERS_FULL; 311 } 312 313 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 314 hci_reserve_packet_buffer(); 315 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 316 va_list argptr; 317 va_start(argptr, identifier); 318 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 319 va_end(argptr); 320 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 321 return hci_send_acl_packet(acl_buffer, len); 322 } 323 324 #ifdef HAVE_BLE 325 int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 326 327 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 328 log_info("l2cap_send_signaling_packet, cannot send\n"); 329 return BTSTACK_ACL_BUFFERS_FULL; 330 } 331 332 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 333 hci_reserve_packet_buffer(); 334 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 335 va_list argptr; 336 va_start(argptr, identifier); 337 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 338 va_end(argptr); 339 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 340 return hci_send_acl_packet(acl_buffer, len); 341 } 342 #endif 343 344 uint8_t *l2cap_get_outgoing_buffer(void){ 345 return hci_get_outgoing_acl_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 346 } 347 348 int l2cap_reserve_packet_buffer(void){ 349 return hci_reserve_packet_buffer(); 350 } 351 352 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 353 354 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 355 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 356 return BTSTACK_ACL_BUFFERS_FULL; 357 } 358 359 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 360 if (!channel) { 361 log_error("l2cap_send_internal no channel for cid 0x%02x\n", local_cid); 362 return -1; // TODO: define error 363 } 364 365 if (channel->packets_granted == 0){ 366 log_error("l2cap_send_internal cid 0x%02x, no credits!\n", local_cid); 367 return -1; // TODO: define error 368 } 369 370 --channel->packets_granted; 371 372 log_debug("l2cap_send_internal cid 0x%02x, handle %u, 1 credit used, credits left %u;\n", 373 local_cid, channel->handle, channel->packets_granted); 374 375 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 376 377 // 0 - Connection handle : PB=10 : BC=00 378 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 379 // 2 - ACL length 380 bt_store_16(acl_buffer, 2, len + 4); 381 // 4 - L2CAP packet length 382 bt_store_16(acl_buffer, 4, len + 0); 383 // 6 - L2CAP channel DEST 384 bt_store_16(acl_buffer, 6, channel->remote_cid); 385 // send 386 int err = hci_send_acl_packet(acl_buffer, len+8); 387 388 l2cap_hand_out_credits(); 389 390 return err; 391 } 392 393 int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len){ 394 395 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 396 log_info("l2cap_send_prepared_to_handle cid 0x%02x, cannot send\n", cid); 397 return BTSTACK_ACL_BUFFERS_FULL; 398 } 399 400 log_debug("l2cap_send_prepared_to_handle cid 0x%02x, handle %u\n", cid, handle); 401 402 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 403 404 // 0 - Connection handle : PB=10 : BC=00 405 bt_store_16(acl_buffer, 0, handle | (2 << 12) | (0 << 14)); 406 // 2 - ACL length 407 bt_store_16(acl_buffer, 2, len + 4); 408 // 4 - L2CAP packet length 409 bt_store_16(acl_buffer, 4, len + 0); 410 // 6 - L2CAP channel DEST 411 bt_store_16(acl_buffer, 6, cid); 412 // send 413 int err = hci_send_acl_packet(acl_buffer, len+8); 414 415 l2cap_hand_out_credits(); 416 417 return err; 418 } 419 420 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 421 422 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 423 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 424 return BTSTACK_ACL_BUFFERS_FULL; 425 } 426 427 hci_reserve_packet_buffer(); 428 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 429 430 memcpy(&acl_buffer[8], data, len); 431 432 return l2cap_send_prepared(local_cid, len); 433 } 434 435 int l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len){ 436 437 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 438 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", cid); 439 return BTSTACK_ACL_BUFFERS_FULL; 440 } 441 442 hci_reserve_packet_buffer(); 443 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 444 445 memcpy(&acl_buffer[8], data, len); 446 447 return l2cap_send_prepared_connectionless(handle, cid, len); 448 } 449 450 int l2cap_send_echo_request(uint16_t handle, uint8_t *data, uint16_t len){ 451 return l2cap_send_signaling_packet(handle, ECHO_REQUEST, 0x77, len, data); 452 } 453 454 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 455 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 456 } 457 458 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 459 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 460 } 461 462 463 464 // MARK: L2CAP_RUN 465 // process outstanding signaling tasks 466 void l2cap_run(void){ 467 468 // check pending signaling responses 469 while (signaling_responses_pending){ 470 471 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)) break; 472 473 hci_con_handle_t handle = signaling_responses[0].handle; 474 uint8_t sig_id = signaling_responses[0].sig_id; 475 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 476 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 477 478 switch (signaling_responses[0].code){ 479 case CONNECTION_REQUEST: 480 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 481 // also disconnect if result is 0x0003 - security blocked 482 hci_disconnect_security_block(handle); 483 break; 484 case ECHO_REQUEST: 485 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 486 break; 487 case INFORMATION_REQUEST: 488 switch (infoType){ 489 case 1: { // Connectionless MTU 490 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 491 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 492 break; 493 } 494 case 2: { // Extended Features Supported 495 // extended features request supported, only supporing fixed channel map 496 uint32_t features = 0x80; 497 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 498 break; 499 } 500 case 3: { // Fixed Channels Supported 501 uint8_t map[8]; 502 memset(map, 0, 8); 503 map[0] = 0x01; // L2CAP Signaling Channel 504 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 505 break; 506 } 507 default: 508 // all other types are not supported 509 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 510 break; 511 } 512 break; 513 case COMMAND_REJECT: 514 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 515 #ifdef HAVE_BLE 516 case COMMAND_REJECT_LE: 517 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 518 break; 519 #endif 520 default: 521 // should not happen 522 break; 523 } 524 525 // remove first item 526 signaling_responses_pending--; 527 int i; 528 for (i=0; i < signaling_responses_pending; i++){ 529 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 530 } 531 } 532 533 uint8_t config_options[4]; 534 linked_item_t *it; 535 linked_item_t *next; 536 for (it = (linked_item_t *) l2cap_channels; it ; it = next){ 537 next = it->next; // cache next item as current item might get freed 538 539 if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) break; 540 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)) break; 541 542 l2cap_channel_t * channel = (l2cap_channel_t *) it; 543 544 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 545 546 547 switch (channel->state){ 548 549 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 550 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 551 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 552 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 553 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 554 } 555 break; 556 557 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 558 // send connection request - set state first 559 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 560 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 561 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 562 break; 563 564 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 565 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 566 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 567 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); // -- remove from list 568 btstack_memory_l2cap_channel_free(channel); 569 break; 570 571 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 572 channel->state = L2CAP_STATE_CONFIG; 573 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 574 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 575 break; 576 577 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 578 // success, start l2cap handshake 579 channel->local_sig_id = l2cap_next_sig_id(); 580 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 581 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 582 l2cap_start_rtx(channel); 583 break; 584 585 case L2CAP_STATE_CONFIG: 586 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 587 uint16_t flags = 0; 588 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 589 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 590 flags = 1; 591 } else { 592 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 593 } 594 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 595 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 596 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 597 config_options[0] = 1; // MTU 598 config_options[1] = 2; // len param 599 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 600 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 601 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 602 } else { 603 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 604 } 605 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 606 } 607 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 608 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 609 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 610 channel->local_sig_id = l2cap_next_sig_id(); 611 config_options[0] = 1; // MTU 612 config_options[1] = 2; // len param 613 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 614 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 615 l2cap_start_rtx(channel); 616 } 617 if (l2cap_channel_ready_for_open(channel)){ 618 channel->state = L2CAP_STATE_OPEN; 619 l2cap_emit_channel_opened(channel, 0); // success 620 l2cap_emit_credits(channel, 1); 621 } 622 break; 623 624 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 625 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 626 // 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 :) 627 l2cap_finialize_channel_close(channel); // -- remove from list 628 break; 629 630 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 631 channel->local_sig_id = l2cap_next_sig_id(); 632 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 633 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 634 break; 635 default: 636 break; 637 } 638 } 639 } 640 641 uint16_t l2cap_max_mtu(void){ 642 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 643 } 644 645 static void l2cap_handle_connection_complete(uint16_t handle, l2cap_channel_t * channel){ 646 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 647 log_info("l2cap_handle_connection_complete expected state"); 648 // success, start l2cap handshake 649 channel->handle = handle; 650 channel->local_cid = l2cap_next_local_cid(); 651 // check remote SSP feature first 652 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 653 } 654 } 655 656 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 657 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 658 659 // we have been waiting for remote supported features, if both support SSP, 660 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)); 661 if (hci_ssp_supported_on_both_sides(channel->handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 662 // request security level 2 663 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 664 gap_request_security_level(channel->handle, LEVEL_2); 665 return; 666 } 667 // fine, go ahead 668 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 669 } 670 671 // open outgoing L2CAP channel 672 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 673 bd_addr_t address, uint16_t psm, uint16_t mtu){ 674 675 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 676 677 // alloc structure 678 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 679 if (!chan) { 680 // emit error event 681 l2cap_channel_t dummy_channel; 682 BD_ADDR_COPY(dummy_channel.address, address); 683 dummy_channel.psm = psm; 684 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 685 return; 686 } 687 // limit local mtu to max acl packet length 688 if (mtu > l2cap_max_mtu()) { 689 mtu = l2cap_max_mtu(); 690 } 691 692 // fill in 693 BD_ADDR_COPY(chan->address, address); 694 chan->psm = psm; 695 chan->handle = 0; 696 chan->connection = connection; 697 chan->packet_handler = packet_handler; 698 chan->remote_mtu = L2CAP_MINIMAL_MTU; 699 chan->local_mtu = mtu; 700 chan->packets_granted = 0; 701 702 // set initial state 703 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 704 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 705 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 706 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 707 chan->required_security_level = LEVEL_0; 708 709 // add to connections list 710 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 711 712 // check if hci connection is already usable 713 hci_connection_t * conn = hci_connection_for_bd_addr((bd_addr_t*)address); 714 if (conn){ 715 log_info("l2cap_create_channel_internal, hci connection already exists"); 716 l2cap_handle_connection_complete(conn->con_handle, chan); 717 // check ir remote supported fearures are already received 718 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 719 l2cap_handle_remote_supported_features_received(chan); 720 } 721 } 722 723 l2cap_run(); 724 } 725 726 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 727 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 728 // find channel for local_cid 729 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 730 if (channel) { 731 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 732 } 733 // process 734 l2cap_run(); 735 } 736 737 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 738 linked_item_t *it = (linked_item_t *) &l2cap_channels; 739 while (it->next){ 740 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 741 if ( ! BD_ADDR_CMP( channel->address, address) ){ 742 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 743 // failure, forward error code 744 l2cap_emit_channel_opened(channel, status); 745 // discard channel 746 it->next = it->next->next; 747 btstack_memory_l2cap_channel_free(channel); 748 } 749 } else { 750 it = it->next; 751 } 752 } 753 } 754 755 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 756 linked_item_t *it; 757 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 758 l2cap_channel_t * channel = (l2cap_channel_t *) it; 759 if ( ! BD_ADDR_CMP( channel->address, address) ){ 760 l2cap_handle_connection_complete(handle, channel); 761 } 762 } 763 // process 764 l2cap_run(); 765 } 766 767 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 768 769 bd_addr_t address; 770 hci_con_handle_t handle; 771 l2cap_channel_t * channel; 772 linked_item_t *it; 773 int hci_con_used; 774 775 switch(packet[0]){ 776 777 // handle connection complete events 778 case HCI_EVENT_CONNECTION_COMPLETE: 779 bt_flip_addr(address, &packet[5]); 780 if (packet[2] == 0){ 781 handle = READ_BT_16(packet, 3); 782 l2cap_handle_connection_success_for_addr(address, handle); 783 } else { 784 l2cap_handle_connection_failed_for_addr(address, packet[2]); 785 } 786 break; 787 788 // handle successful create connection cancel command 789 case HCI_EVENT_COMMAND_COMPLETE: 790 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 791 if (packet[5] == 0){ 792 bt_flip_addr(address, &packet[6]); 793 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 794 l2cap_handle_connection_failed_for_addr(address, 0x16); 795 } 796 } 797 l2cap_run(); // try sending signaling packets first 798 break; 799 800 case HCI_EVENT_COMMAND_STATUS: 801 l2cap_run(); // try sending signaling packets first 802 break; 803 804 // handle disconnection complete events 805 case HCI_EVENT_DISCONNECTION_COMPLETE: 806 // send l2cap disconnect events for all channels on this handle 807 handle = READ_BT_16(packet, 3); 808 it = (linked_item_t *) &l2cap_channels; 809 while (it->next){ 810 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 811 if ( channel->handle == handle ){ 812 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 813 it->next = it->next->next; 814 l2cap_emit_channel_closed(channel); 815 btstack_memory_l2cap_channel_free(channel); 816 } else { 817 it = it->next; 818 } 819 } 820 break; 821 822 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 823 l2cap_run(); // try sending signaling packets first 824 l2cap_hand_out_credits(); 825 break; 826 827 // HCI Connection Timeouts 828 case L2CAP_EVENT_TIMEOUT_CHECK: 829 handle = READ_BT_16(packet, 2); 830 if (hci_authentication_active_for_handle(handle)) break; 831 hci_con_used = 0; 832 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 833 channel = (l2cap_channel_t *) it; 834 if (channel->handle == handle) { 835 hci_con_used = 1; 836 } 837 } 838 if (hci_con_used) break; 839 if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) break; 840 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 841 break; 842 843 case DAEMON_EVENT_HCI_PACKET_SENT: 844 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 845 channel = (l2cap_channel_t *) it; 846 if (channel->packet_handler) { 847 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 848 } 849 } 850 if (attribute_protocol_packet_handler) { 851 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 852 } 853 if (security_protocol_packet_handler) { 854 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 855 } 856 break; 857 858 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 859 handle = READ_BT_16(packet, 3); 860 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 861 channel = (l2cap_channel_t *) it; 862 if (channel->handle != handle) continue; 863 l2cap_handle_remote_supported_features_received(channel); 864 break; 865 } 866 867 case GAP_SECURITY_LEVEL: 868 handle = READ_BT_16(packet, 2); 869 log_info("l2cap - security level update"); 870 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 871 channel = (l2cap_channel_t *) it; 872 if (channel->handle != handle) continue; 873 874 log_info("l2cap - state %u", channel->state); 875 876 gap_security_level_t actual_level = packet[4]; 877 gap_security_level_t required_level = channel->required_security_level; 878 879 switch (channel->state){ 880 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 881 if (actual_level >= required_level){ 882 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 883 l2cap_emit_connection_request(channel); 884 } else { 885 channel->reason = 0x03; // security block 886 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 887 } 888 break; 889 890 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 891 if (actual_level >= required_level){ 892 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 893 } else { 894 // disconnnect, authentication not good enough 895 hci_disconnect_security_block(handle); 896 } 897 break; 898 899 default: 900 break; 901 } 902 } 903 break; 904 905 default: 906 break; 907 } 908 909 // pass on 910 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 911 912 l2cap_run(); 913 } 914 915 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 916 channel->remote_sig_id = identifier; 917 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 918 l2cap_run(); 919 } 920 921 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 922 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 923 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 924 signaling_responses[signaling_responses_pending].handle = handle; 925 signaling_responses[signaling_responses_pending].code = code; 926 signaling_responses[signaling_responses_pending].sig_id = sig_id; 927 signaling_responses[signaling_responses_pending].data = data; 928 signaling_responses_pending++; 929 l2cap_run(); 930 } 931 } 932 933 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 934 935 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 936 l2cap_service_t *service = l2cap_get_service(psm); 937 if (!service) { 938 // 0x0002 PSM not supported 939 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 940 return; 941 } 942 943 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 944 if (!hci_connection) { 945 // 946 log_error("no hci_connection for handle %u\n", handle); 947 return; 948 } 949 950 // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP 951 if ( hci_ssp_supported_on_both_sides(handle) 952 && gap_security_level(handle) == LEVEL_0 953 && !l2cap_security_level_0_allowed_for_PSM(psm)){ 954 955 // 0x0003 Security Block 956 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); 957 return; 958 } 959 960 961 // alloc structure 962 // log_info("l2cap_handle_connection_request register channel\n"); 963 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 964 if (!channel){ 965 // 0x0004 No resources available 966 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 967 return; 968 } 969 970 // fill in 971 BD_ADDR_COPY(channel->address, hci_connection->address); 972 channel->psm = psm; 973 channel->handle = handle; 974 channel->connection = service->connection; 975 channel->packet_handler = service->packet_handler; 976 channel->local_cid = l2cap_next_local_cid(); 977 channel->remote_cid = source_cid; 978 channel->local_mtu = service->mtu; 979 channel->remote_mtu = L2CAP_DEFAULT_MTU; 980 channel->packets_granted = 0; 981 channel->remote_sig_id = sig_id; 982 channel->required_security_level = service->required_security_level; 983 984 // limit local mtu to max acl packet length 985 if (channel->local_mtu > l2cap_max_mtu()) { 986 channel->local_mtu = l2cap_max_mtu(); 987 } 988 989 // set initial state 990 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 991 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 992 993 // add to connections list 994 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 995 996 // assert security requirements 997 gap_request_security_level(handle, channel->required_security_level); 998 } 999 1000 void l2cap_accept_connection_internal(uint16_t local_cid){ 1001 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1002 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1003 if (!channel) { 1004 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 1005 return; 1006 } 1007 1008 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1009 1010 // process 1011 l2cap_run(); 1012 } 1013 1014 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 1015 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 1016 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1017 if (!channel) { 1018 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 1019 return; 1020 } 1021 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1022 channel->reason = reason; 1023 l2cap_run(); 1024 } 1025 1026 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1027 1028 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1029 1030 uint16_t flags = READ_BT_16(command, 6); 1031 if (flags & 1) { 1032 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1033 } 1034 1035 // accept the other's configuration options 1036 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1037 uint16_t pos = 8; 1038 while (pos < end_pos){ 1039 uint8_t option_hint = command[pos] >> 7; 1040 uint8_t option_type = command[pos] & 0x7f; 1041 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1042 pos++; 1043 uint8_t length = command[pos++]; 1044 // MTU { type(8): 1, len(8):2, MTU(16) } 1045 if (option_type == 1 && length == 2){ 1046 channel->remote_mtu = READ_BT_16(command, pos); 1047 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 1048 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1049 } 1050 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1051 if (option_type == 2 && length == 2){ 1052 channel->flush_timeout = READ_BT_16(command, pos); 1053 } 1054 // check for unknown options 1055 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1056 log_info("l2cap cid %u, unknown options", channel->local_cid); 1057 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1058 } 1059 pos += length; 1060 } 1061 } 1062 1063 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1064 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 1065 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1066 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1067 return 1; 1068 } 1069 1070 1071 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1072 1073 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1074 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1075 uint16_t result = 0; 1076 1077 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 1078 1079 // handle DISCONNECT REQUESTS seperately 1080 if (code == DISCONNECTION_REQUEST){ 1081 switch (channel->state){ 1082 case L2CAP_STATE_CONFIG: 1083 case L2CAP_STATE_OPEN: 1084 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1085 case L2CAP_STATE_WAIT_DISCONNECT: 1086 l2cap_handle_disconnect_request(channel, identifier); 1087 break; 1088 1089 default: 1090 // ignore in other states 1091 break; 1092 } 1093 return; 1094 } 1095 1096 // @STATEMACHINE(l2cap) 1097 switch (channel->state) { 1098 1099 case L2CAP_STATE_WAIT_CONNECT_RSP: 1100 switch (code){ 1101 case CONNECTION_RESPONSE: 1102 l2cap_stop_rtx(channel); 1103 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1104 switch (result) { 1105 case 0: 1106 // successful connection 1107 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1108 channel->state = L2CAP_STATE_CONFIG; 1109 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1110 break; 1111 case 1: 1112 // connection pending. get some coffee, but start the ERTX 1113 l2cap_start_ertx(channel); 1114 break; 1115 default: 1116 // channel closed 1117 channel->state = L2CAP_STATE_CLOSED; 1118 // map l2cap connection response result to BTstack status enumeration 1119 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1120 1121 // drop link key if security block 1122 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1123 hci_drop_link_key_for_bd_addr(&channel->address); 1124 } 1125 1126 // discard channel 1127 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1128 btstack_memory_l2cap_channel_free(channel); 1129 break; 1130 } 1131 break; 1132 1133 default: 1134 //@TODO: implement other signaling packets 1135 break; 1136 } 1137 break; 1138 1139 case L2CAP_STATE_CONFIG: 1140 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1141 switch (code) { 1142 case CONFIGURE_REQUEST: 1143 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1144 l2cap_signaling_handle_configure_request(channel, command); 1145 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1146 // only done if continuation not set 1147 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1148 } 1149 break; 1150 case CONFIGURE_RESPONSE: 1151 l2cap_stop_rtx(channel); 1152 switch (result){ 1153 case 0: // success 1154 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1155 break; 1156 case 4: // pending 1157 l2cap_start_ertx(channel); 1158 break; 1159 default: 1160 // retry on negative result 1161 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1162 break; 1163 } 1164 break; 1165 default: 1166 break; 1167 } 1168 if (l2cap_channel_ready_for_open(channel)){ 1169 // for open: 1170 channel->state = L2CAP_STATE_OPEN; 1171 l2cap_emit_channel_opened(channel, 0); 1172 l2cap_emit_credits(channel, 1); 1173 } 1174 break; 1175 1176 case L2CAP_STATE_WAIT_DISCONNECT: 1177 switch (code) { 1178 case DISCONNECTION_RESPONSE: 1179 l2cap_finialize_channel_close(channel); 1180 break; 1181 default: 1182 //@TODO: implement other signaling packets 1183 break; 1184 } 1185 break; 1186 1187 case L2CAP_STATE_CLOSED: 1188 // @TODO handle incoming requests 1189 break; 1190 1191 case L2CAP_STATE_OPEN: 1192 //@TODO: implement other signaling packets, e.g. re-configure 1193 break; 1194 default: 1195 break; 1196 } 1197 // log_info("new state %u\n", channel->state); 1198 } 1199 1200 1201 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1202 1203 // get code, signalind identifier and command len 1204 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1205 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1206 1207 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1208 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1209 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1210 return; 1211 } 1212 1213 // general commands without an assigned channel 1214 switch(code) { 1215 1216 case CONNECTION_REQUEST: { 1217 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1218 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1219 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1220 return; 1221 } 1222 1223 case ECHO_REQUEST: 1224 l2cap_register_signaling_response(handle, code, sig_id, 0); 1225 return; 1226 1227 case INFORMATION_REQUEST: { 1228 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1229 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1230 return; 1231 } 1232 1233 default: 1234 break; 1235 } 1236 1237 1238 // Get potential destination CID 1239 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1240 1241 // Find channel for this sig_id and connection handle 1242 linked_item_t *it; 1243 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1244 l2cap_channel_t * channel = (l2cap_channel_t *) it; 1245 if (channel->handle == handle) { 1246 if (code & 1) { 1247 // match odd commands (responses) by previous signaling identifier 1248 if (channel->local_sig_id == sig_id) { 1249 l2cap_signaling_handler_channel(channel, command); 1250 break; 1251 } 1252 } else { 1253 // match even commands (requests) by local channel id 1254 if (channel->local_cid == dest_cid) { 1255 l2cap_signaling_handler_channel(channel, command); 1256 break; 1257 } 1258 } 1259 } 1260 } 1261 } 1262 1263 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1264 1265 // Get Channel ID 1266 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1267 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1268 1269 switch (channel_id) { 1270 1271 case L2CAP_CID_SIGNALING: { 1272 1273 uint16_t command_offset = 8; 1274 while (command_offset < size) { 1275 1276 // handle signaling commands 1277 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1278 1279 // increment command_offset 1280 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1281 } 1282 break; 1283 } 1284 1285 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1286 if (attribute_protocol_packet_handler) { 1287 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1288 } 1289 break; 1290 1291 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1292 if (security_protocol_packet_handler) { 1293 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1294 } 1295 break; 1296 1297 case L2CAP_CID_SIGNALING_LE: { 1298 // not implemented yet for LE Peripheral 1299 uint8_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1300 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1301 break; 1302 } 1303 1304 default: { 1305 // Find channel for this channel_id and connection handle 1306 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1307 if (channel) { 1308 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1309 } 1310 break; 1311 } 1312 } 1313 } 1314 1315 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1316 switch (packet_type) { 1317 case HCI_EVENT_PACKET: 1318 l2cap_event_handler(packet, size); 1319 break; 1320 case HCI_ACL_DATA_PACKET: 1321 l2cap_acl_handler(packet, size); 1322 break; 1323 default: 1324 break; 1325 } 1326 l2cap_run(); 1327 } 1328 1329 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1330 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1331 channel->state = L2CAP_STATE_CLOSED; 1332 l2cap_emit_channel_closed(channel); 1333 // discard channel 1334 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1335 btstack_memory_l2cap_channel_free(channel); 1336 } 1337 1338 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1339 linked_item_t *it; 1340 1341 // close open channels 1342 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 1343 l2cap_service_t * service = ((l2cap_service_t *) it); 1344 if ( service->psm == psm){ 1345 return service; 1346 }; 1347 } 1348 return NULL; 1349 } 1350 1351 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){ 1352 1353 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1354 1355 // check for alread registered psm 1356 // TODO: emit error event 1357 l2cap_service_t *service = l2cap_get_service(psm); 1358 if (service) { 1359 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1360 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1361 return; 1362 } 1363 1364 // alloc structure 1365 // TODO: emit error event 1366 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1367 if (!service) { 1368 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1369 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1370 return; 1371 } 1372 1373 // fill in 1374 service->psm = psm; 1375 service->mtu = mtu; 1376 service->connection = connection; 1377 service->packet_handler = packet_handler; 1378 service->required_security_level = security_level; 1379 1380 // add to services list 1381 linked_list_add(&l2cap_services, (linked_item_t *) service); 1382 1383 // enable page scan 1384 hci_connectable_control(1); 1385 1386 // done 1387 l2cap_emit_service_registered(connection, 0, psm); 1388 } 1389 1390 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1391 1392 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1393 1394 l2cap_service_t *service = l2cap_get_service(psm); 1395 if (!service) return; 1396 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1397 btstack_memory_l2cap_service_free(service); 1398 1399 // disable page scan when no services registered 1400 if (!linked_list_empty(&l2cap_services)) return; 1401 hci_connectable_control(0); 1402 } 1403 1404 // 1405 void l2cap_close_connection(void *connection){ 1406 linked_item_t *it; 1407 1408 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1409 l2cap_channel_t * channel; 1410 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1411 channel = (l2cap_channel_t *) it; 1412 if (channel->connection == connection) { 1413 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1414 } 1415 } 1416 1417 // unregister services 1418 it = (linked_item_t *) &l2cap_services; 1419 while (it->next) { 1420 l2cap_service_t * service = (l2cap_service_t *) it->next; 1421 if (service->connection == connection){ 1422 it->next = it->next->next; 1423 btstack_memory_l2cap_service_free(service); 1424 } else { 1425 it = it->next; 1426 } 1427 } 1428 1429 // process 1430 l2cap_run(); 1431 } 1432 1433 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1434 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1435 switch(channel_id){ 1436 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1437 attribute_protocol_packet_handler = packet_handler; 1438 break; 1439 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1440 security_protocol_packet_handler = packet_handler; 1441 break; 1442 } 1443 } 1444 1445 #ifdef HAVE_BLE 1446 // Request LE connection parameter update 1447 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){ 1448 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 1449 log_info("l2cap_send_signaling_packet, cannot send\n"); 1450 return BTSTACK_ACL_BUFFERS_FULL; 1451 } 1452 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1453 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 1454 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1455 return hci_send_acl_packet(acl_buffer, len); 1456 } 1457 #endif 1458 1459