l2cap_signal.c revision 1.4
1 /* $NetBSD: l2cap_signal.c,v 1.4 2007/03/05 19:04:46 plunky Exp $ */ 2 3 /*- 4 * Copyright (c) 2005 Iain Hibbert. 5 * Copyright (c) 2006 Itronix Inc. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. The name of Itronix Inc. may not be used to endorse 17 * or promote products derived from this software without specific 18 * prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY ITRONIX INC. ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL ITRONIX INC. BE LIABLE FOR ANY 24 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 25 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 26 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 27 * ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #include <sys/cdefs.h> 34 __KERNEL_RCSID(0, "$NetBSD: l2cap_signal.c,v 1.4 2007/03/05 19:04:46 plunky Exp $"); 35 36 #include <sys/param.h> 37 #include <sys/kernel.h> 38 #include <sys/mbuf.h> 39 #include <sys/proc.h> 40 #include <sys/queue.h> 41 #include <sys/systm.h> 42 43 #include <machine/stdarg.h> 44 45 #include <netbt/bluetooth.h> 46 #include <netbt/hci.h> 47 #include <netbt/l2cap.h> 48 49 /******************************************************************************* 50 * 51 * L2CAP Signal processing 52 */ 53 54 static void l2cap_recv_command_rej(struct mbuf *, struct hci_link *); 55 static void l2cap_recv_connect_req(struct mbuf *, struct hci_link *); 56 static void l2cap_recv_connect_rsp(struct mbuf *, struct hci_link *); 57 static void l2cap_recv_config_req(struct mbuf *, struct hci_link *); 58 static void l2cap_recv_config_rsp(struct mbuf *, struct hci_link *); 59 static void l2cap_recv_disconnect_req(struct mbuf *, struct hci_link *); 60 static void l2cap_recv_disconnect_rsp(struct mbuf *, struct hci_link *); 61 static void l2cap_recv_info_req(struct mbuf *, struct hci_link *); 62 static int l2cap_send_signal(struct hci_link *, uint8_t, uint8_t, uint16_t, void *); 63 static int l2cap_send_command_rej(struct hci_link *, uint8_t, uint16_t, ...); 64 65 /* 66 * process incoming signal packets (CID 0x0001). Can contain multiple 67 * requests/responses. 68 */ 69 void 70 l2cap_recv_signal(struct mbuf *m, struct hci_link *link) 71 { 72 l2cap_cmd_hdr_t cmd; 73 74 for(;;) { 75 if (m->m_pkthdr.len == 0) 76 goto finish; 77 78 if (m->m_pkthdr.len < sizeof(cmd)) 79 goto reject; 80 81 m_copydata(m, 0, sizeof(cmd), &cmd); 82 cmd.length = le16toh(cmd.length); 83 84 if (m->m_pkthdr.len < sizeof(cmd) + cmd.length) 85 goto reject; 86 87 DPRINTFN(2, "(%s) code %d, ident %d, len %d\n", 88 link->hl_unit->hci_devname, 89 cmd.code, cmd.ident, cmd.length); 90 91 switch (cmd.code) { 92 case L2CAP_COMMAND_REJ: 93 if (cmd.length > sizeof(l2cap_cmd_rej_cp)) 94 goto finish; 95 96 l2cap_recv_command_rej(m, link); 97 break; 98 99 case L2CAP_CONNECT_REQ: 100 if (cmd.length != sizeof(l2cap_con_req_cp)) 101 goto reject; 102 103 l2cap_recv_connect_req(m, link); 104 break; 105 106 case L2CAP_CONNECT_RSP: 107 if (cmd.length != sizeof(l2cap_con_rsp_cp)) 108 goto finish; 109 110 l2cap_recv_connect_rsp(m, link); 111 break; 112 113 case L2CAP_CONFIG_REQ: 114 l2cap_recv_config_req(m, link); 115 break; 116 117 case L2CAP_CONFIG_RSP: 118 l2cap_recv_config_rsp(m, link); 119 break; 120 121 case L2CAP_DISCONNECT_REQ: 122 if (cmd.length != sizeof(l2cap_discon_req_cp)) 123 goto reject; 124 125 l2cap_recv_disconnect_req(m, link); 126 break; 127 128 case L2CAP_DISCONNECT_RSP: 129 if (cmd.length != sizeof(l2cap_discon_rsp_cp)) 130 goto finish; 131 132 l2cap_recv_disconnect_rsp(m, link); 133 break; 134 135 case L2CAP_ECHO_REQ: 136 m_adj(m, sizeof(cmd) + cmd.length); 137 l2cap_send_signal(link, L2CAP_ECHO_RSP, cmd.ident, 138 0, NULL); 139 break; 140 141 case L2CAP_ECHO_RSP: 142 m_adj(m, sizeof(cmd) + cmd.length); 143 break; 144 145 case L2CAP_INFO_REQ: 146 if (cmd.length != sizeof(l2cap_info_req_cp)) 147 goto reject; 148 149 l2cap_recv_info_req(m, link); 150 break; 151 152 case L2CAP_INFO_RSP: 153 m_adj(m, sizeof(cmd) + cmd.length); 154 break; 155 156 default: 157 goto reject; 158 } 159 } 160 161 #ifdef DIAGNOSTIC 162 panic("impossible!"); 163 #endif 164 165 reject: 166 l2cap_send_command_rej(link, cmd.ident, L2CAP_REJ_NOT_UNDERSTOOD); 167 finish: 168 m_freem(m); 169 } 170 171 /* 172 * Process Received Command Reject. For now we dont try to recover gracefully 173 * from this, it probably means that the link is garbled or the other end is 174 * insufficiently capable of handling normal traffic. (not *my* fault, no way!) 175 */ 176 static void 177 l2cap_recv_command_rej(struct mbuf *m, struct hci_link *link) 178 { 179 struct l2cap_req *req; 180 struct l2cap_channel *chan; 181 l2cap_cmd_hdr_t cmd; 182 l2cap_cmd_rej_cp cp; 183 184 m_copydata(m, 0, sizeof(cmd), &cmd); 185 m_adj(m, sizeof(cmd)); 186 187 cmd.length = le16toh(cmd.length); 188 189 m_copydata(m, 0, cmd.length, &cp); 190 m_adj(m, cmd.length); 191 192 req = l2cap_request_lookup(link, cmd.ident); 193 if (req == NULL) 194 return; 195 196 switch (le16toh(cp.reason)) { 197 case L2CAP_REJ_NOT_UNDERSTOOD: 198 /* 199 * I dont know what to do, just move up the timeout 200 */ 201 callout_schedule(&req->lr_rtx, 0); 202 break; 203 204 case L2CAP_REJ_MTU_EXCEEDED: 205 /* 206 * I didnt send any commands over L2CAP_MTU_MINIMUM size, but.. 207 */ 208 link->hl_mtu = le16toh(cp.data[0]); 209 callout_schedule(&req->lr_rtx, 0); // XX maybe resend instead? 210 break; 211 212 case L2CAP_REJ_INVALID_CID: 213 /* 214 * Well, if they dont have such a channel then our channel is 215 * most likely closed. Make it so. 216 */ 217 chan = req->lr_chan; 218 l2cap_request_free(req); 219 if (chan != NULL && chan->lc_state != L2CAP_CLOSED) 220 l2cap_close(chan, ECONNABORTED); 221 222 break; 223 224 default: 225 UNKNOWN(le16toh(cp.reason)); 226 break; 227 } 228 } 229 230 /* 231 * Process Received Connect Request. Find listening channel matching 232 * psm & addr and ask upper layer for a new channel. 233 */ 234 static void 235 l2cap_recv_connect_req(struct mbuf *m, struct hci_link *link) 236 { 237 struct sockaddr_bt laddr, raddr; 238 struct l2cap_channel *chan, *new; 239 l2cap_cmd_hdr_t cmd; 240 l2cap_con_req_cp cp; 241 l2cap_con_rsp_cp rp; 242 int err; 243 244 /* extract cmd */ 245 m_copydata(m, 0, sizeof(cmd), &cmd); 246 m_adj(m, sizeof(cmd)); 247 248 /* extract request */ 249 m_copydata(m, 0, sizeof(cp), &cp); 250 m_adj(m, sizeof(cp)); 251 252 /* init response */ 253 memset(&rp, 0, sizeof(rp)); 254 rp.scid = cp.scid; 255 256 memset(&laddr, 0, sizeof(struct sockaddr_bt)); 257 laddr.bt_len = sizeof(struct sockaddr_bt); 258 laddr.bt_family = AF_BLUETOOTH; 259 laddr.bt_psm = le16toh(cp.psm); 260 bdaddr_copy(&laddr.bt_bdaddr, &link->hl_unit->hci_bdaddr); 261 262 memset(&raddr, 0, sizeof(struct sockaddr_bt)); 263 raddr.bt_len = sizeof(struct sockaddr_bt); 264 raddr.bt_family = AF_BLUETOOTH; 265 raddr.bt_psm = le16toh(cp.psm); 266 bdaddr_copy(&raddr.bt_bdaddr, &link->hl_bdaddr); 267 268 LIST_FOREACH(chan, &l2cap_listen_list, lc_ncid) { 269 if (chan->lc_laddr.bt_psm != laddr.bt_psm 270 && chan->lc_laddr.bt_psm != L2CAP_PSM_ANY) 271 continue; 272 273 if (!bdaddr_same(&laddr.bt_bdaddr, &chan->lc_laddr.bt_bdaddr) 274 && bdaddr_any(&chan->lc_laddr.bt_bdaddr) == 0) 275 continue; 276 277 new= (*chan->lc_proto->newconn)(chan->lc_upper, &laddr, &raddr); 278 if (new == NULL) 279 continue; 280 281 err = l2cap_cid_alloc(new); 282 if (err) { 283 rp.result = htole16(L2CAP_NO_RESOURCES); 284 l2cap_send_signal(link, L2CAP_CONNECT_RSP, 285 cmd.ident, sizeof(rp), &rp); 286 (*new->lc_proto->disconnected)(new->lc_upper, err); 287 return; 288 } 289 290 new->lc_link = hci_acl_open(link->hl_unit, &link->hl_bdaddr); 291 KASSERT(new->lc_link == link); 292 293 new->lc_rcid = le16toh(cp.scid); 294 295 memcpy(&new->lc_laddr, &laddr, sizeof(struct sockaddr_bt)); 296 memcpy(&new->lc_raddr, &raddr, sizeof(struct sockaddr_bt)); 297 298 rp.dcid = htole16(new->lc_lcid); 299 rp.result = htole16(L2CAP_SUCCESS); 300 l2cap_send_signal(link, L2CAP_CONNECT_RSP, cmd.ident, 301 sizeof(rp), &rp); 302 303 new->lc_state = L2CAP_WAIT_CONFIG_REQ | L2CAP_WAIT_CONFIG_RSP; 304 l2cap_send_config_req(new); 305 return; 306 } 307 308 rp.result = htole16(L2CAP_PSM_NOT_SUPPORTED); 309 l2cap_send_signal(link, L2CAP_CONNECT_RSP, cmd.ident, sizeof(rp), &rp); 310 } 311 312 /* 313 * Process Received Connect Response. 314 */ 315 static void 316 l2cap_recv_connect_rsp(struct mbuf *m, struct hci_link *link) 317 { 318 l2cap_cmd_hdr_t cmd; 319 l2cap_con_rsp_cp cp; 320 struct l2cap_req *req; 321 struct l2cap_channel *chan; 322 323 m_copydata(m, 0, sizeof(cmd), &cmd); 324 m_adj(m, sizeof(cmd)); 325 326 m_copydata(m, 0, sizeof(cp), &cp); 327 m_adj(m, sizeof(cp)); 328 329 cp.scid = le16toh(cp.scid); 330 cp.dcid = le16toh(cp.dcid); 331 cp.result = le16toh(cp.result); 332 333 req = l2cap_request_lookup(link, cmd.ident); 334 if (req == NULL || req->lr_code != L2CAP_CONNECT_REQ) 335 return; 336 337 chan = req->lr_chan; 338 if (chan != NULL && chan->lc_lcid != cp.scid) 339 return; 340 341 if (chan == NULL || chan->lc_state != L2CAP_WAIT_CONNECT_RSP) { 342 l2cap_request_free(req); 343 return; 344 } 345 346 switch (cp.result) { 347 case L2CAP_SUCCESS: 348 /* 349 * Ok, at this point we have a connection to the other party. We 350 * could indicate upstream that we are ready for business and 351 * wait for a "Configure Channel Request" but I'm not so sure 352 * that is required in our case - we will proceed directly to 353 * sending our config request. We set two state bits because in 354 * the config state we are waiting for requests and responses. 355 */ 356 l2cap_request_free(req); 357 chan->lc_rcid = cp.dcid; 358 chan->lc_state = L2CAP_WAIT_CONFIG_REQ | L2CAP_WAIT_CONFIG_RSP; 359 l2cap_send_config_req(chan); 360 break; 361 362 case L2CAP_PENDING: 363 // dont release request, should start eRTX timeout? 364 (*chan->lc_proto->connecting)(chan->lc_upper); 365 break; 366 367 case L2CAP_PSM_NOT_SUPPORTED: 368 case L2CAP_SECURITY_BLOCK: 369 case L2CAP_NO_RESOURCES: 370 default: 371 l2cap_request_free(req); 372 l2cap_close(chan, ECONNREFUSED); 373 break; 374 } 375 } 376 377 /* 378 * Process Received Config Reqest. 379 */ 380 static void 381 l2cap_recv_config_req(struct mbuf *m, struct hci_link *link) 382 { 383 uint8_t buf[L2CAP_MTU_MINIMUM]; 384 l2cap_cmd_hdr_t cmd; 385 l2cap_cfg_req_cp cp; 386 l2cap_cfg_opt_t opt; 387 l2cap_cfg_opt_val_t val; 388 l2cap_cfg_rsp_cp rp; 389 struct l2cap_channel *chan; 390 int left, len; 391 392 m_copydata(m, 0, sizeof(cmd), &cmd); 393 m_adj(m, sizeof(cmd)); 394 left = le16toh(cmd.length); 395 396 if (left < sizeof(cp)) 397 goto reject; 398 399 m_copydata(m, 0, sizeof(cp), &cp); 400 m_adj(m, sizeof(cp)); 401 left -= sizeof(cp); 402 403 cp.dcid = le16toh(cp.dcid); 404 cp.flags = le16toh(cp.flags); 405 406 chan = l2cap_cid_lookup(cp.dcid); 407 if (chan == NULL || chan->lc_link != link 408 || (chan->lc_state & L2CAP_WAIT_CONFIG_REQ) == 0) { 409 l2cap_send_command_rej(link, cmd.ident, L2CAP_REJ_INVALID_CID, 410 L2CAP_NULL_CID, cp.dcid); 411 goto out; 412 } 413 414 /* ready our response packet */ 415 rp.scid = htole16(chan->lc_rcid); 416 rp.flags = 0; /* "No Continuation" */ 417 rp.result = L2CAP_SUCCESS; 418 len = sizeof(rp); 419 420 /* 421 * Process the packet. We build the return packet on the fly adding any 422 * unacceptable parameters as we go. As we can only return one result, 423 * unknown option takes precedence so we start our return packet anew 424 * and ignore option values thereafter as they will be re-sent. 425 * 426 * Since we do not support enough options to make overflowing the min 427 * MTU size an issue in normal use, we just reject config requests that 428 * make that happen. This could be because options are repeated or the 429 * packet is corrupted in some way. 430 * 431 * If unknown option types threaten to overflow the packet, we just 432 * ignore them. We can deny them next time. 433 */ 434 while (left > 0) { 435 if (left < sizeof(opt)) 436 goto reject; 437 438 m_copydata(m, 0, sizeof(opt), &opt); 439 m_adj(m, sizeof(opt)); 440 left -= sizeof(opt); 441 442 if (left < opt.length) 443 goto reject; 444 445 switch(opt.type & L2CAP_OPT_HINT_MASK) { 446 case L2CAP_OPT_MTU: 447 if (rp.result == L2CAP_UNKNOWN_OPTION) 448 break; 449 450 if (opt.length != L2CAP_OPT_MTU_SIZE) 451 goto reject; 452 453 m_copydata(m, 0, L2CAP_OPT_MTU_SIZE, &val); 454 val.mtu = le16toh(val.mtu); 455 456 /* 457 * XXX how do we know what the minimum acceptable MTU is 458 * for a channel? Spec says some profiles have a higher 459 * minimum but I have no way to find that out at this 460 * juncture.. 461 */ 462 if (val.mtu < L2CAP_MTU_MINIMUM) { 463 if (len + sizeof(opt) + L2CAP_OPT_MTU_SIZE > sizeof(buf)) 464 goto reject; 465 466 rp.result = L2CAP_UNACCEPTABLE_PARAMS; 467 memcpy(buf + len, &opt, sizeof(opt)); 468 len += sizeof(opt); 469 val.mtu = htole16(L2CAP_MTU_MINIMUM); 470 memcpy(buf + len, &val, L2CAP_OPT_MTU_SIZE); 471 len += L2CAP_OPT_MTU_SIZE; 472 } else 473 chan->lc_omtu = val.mtu; 474 475 break; 476 477 case L2CAP_OPT_FLUSH_TIMO: 478 if (rp.result == L2CAP_UNKNOWN_OPTION) 479 break; 480 481 if (opt.length != L2CAP_OPT_FLUSH_TIMO_SIZE) 482 goto reject; 483 484 /* 485 * I think that this is informational only - he is 486 * informing us of the flush timeout he will be using. 487 * I dont think this affects us in any significant way, 488 * so just ignore this value for now. 489 */ 490 break; 491 492 case L2CAP_OPT_QOS: 493 default: 494 /* ignore hints */ 495 if (opt.type & L2CAP_OPT_HINT_BIT) 496 break; 497 498 /* unknown options supercede all else */ 499 if (rp.result != L2CAP_UNKNOWN_OPTION) { 500 rp.result = L2CAP_UNKNOWN_OPTION; 501 len = sizeof(rp); 502 } 503 504 /* ignore if it don't fit */ 505 if (len + sizeof(opt) > sizeof(buf)) 506 break; 507 508 /* return unknown option type, but no data */ 509 buf[len++] = opt.type; 510 buf[len++] = 0; 511 break; 512 } 513 514 m_adj(m, opt.length); 515 left -= opt.length; 516 } 517 518 rp.result = htole16(rp.result); 519 memcpy(buf, &rp, sizeof(rp)); 520 l2cap_send_signal(link, L2CAP_CONFIG_RSP, cmd.ident, len, buf); 521 522 if ((cp.flags & L2CAP_OPT_CFLAG_BIT) == 0 523 && rp.result == le16toh(L2CAP_SUCCESS)) { 524 525 chan->lc_state &= ~L2CAP_WAIT_CONFIG_REQ; 526 527 if ((chan->lc_state & L2CAP_WAIT_CONFIG_RSP) == 0) { 528 chan->lc_state = L2CAP_OPEN; 529 // XXX how to distinguish REconfiguration? 530 (*chan->lc_proto->connected)(chan->lc_upper); 531 } 532 } 533 return; 534 535 reject: 536 l2cap_send_command_rej(link, cmd.ident, L2CAP_REJ_NOT_UNDERSTOOD); 537 out: 538 m_adj(m, left); 539 } 540 541 /* 542 * Process Received Config Response. 543 */ 544 static void 545 l2cap_recv_config_rsp(struct mbuf *m, struct hci_link *link) 546 { 547 l2cap_cmd_hdr_t cmd; 548 l2cap_cfg_rsp_cp cp; 549 l2cap_cfg_opt_t opt; 550 l2cap_cfg_opt_val_t val; 551 struct l2cap_req *req; 552 struct l2cap_channel *chan; 553 int left; 554 555 m_copydata(m, 0, sizeof(cmd), &cmd); 556 m_adj(m, sizeof(cmd)); 557 left = le16toh(cmd.length); 558 559 if (left < sizeof(cp)) 560 goto out; 561 562 m_copydata(m, 0, sizeof(cp), &cp); 563 m_adj(m, sizeof(cp)); 564 left -= sizeof(cp); 565 566 cp.scid = le16toh(cp.scid); 567 cp.flags = le16toh(cp.flags); 568 cp.result = le16toh(cp.result); 569 570 req = l2cap_request_lookup(link, cmd.ident); 571 if (req == NULL || req->lr_code != L2CAP_CONFIG_REQ) 572 goto out; 573 574 chan = req->lr_chan; 575 if (chan != NULL && chan->lc_lcid != cp.scid) 576 goto out; 577 578 l2cap_request_free(req); 579 580 if (chan == NULL || (chan->lc_state & L2CAP_WAIT_CONFIG_RSP) == 0) 581 goto out; 582 583 if ((cp.flags & L2CAP_OPT_CFLAG_BIT)) { 584 l2cap_cfg_req_cp rp; 585 586 /* 587 * They have more to tell us and want another ID to 588 * use, so send an empty config request 589 */ 590 if (l2cap_request_alloc(chan, L2CAP_CONFIG_REQ)) 591 goto discon; 592 593 rp.dcid = htole16(cp.scid); 594 rp.flags = 0; 595 596 if (l2cap_send_signal(link, L2CAP_CONFIG_REQ, link->hl_lastid, 597 sizeof(rp), &rp)) 598 goto discon; 599 } 600 601 switch(cp.result) { 602 case L2CAP_SUCCESS: 603 /* 604 * If continuation flag was not set, our config request was 605 * accepted. We may have to wait for their config request to 606 * complete, so check that but otherwise we are open 607 * 608 * There may be 'advisory' values in the packet but we just 609 * ignore those.. 610 */ 611 if ((cp.flags & L2CAP_OPT_CFLAG_BIT) == 0) { 612 chan->lc_state &= ~L2CAP_WAIT_CONFIG_RSP; 613 614 if ((chan->lc_state & L2CAP_WAIT_CONFIG_REQ) == 0) { 615 chan->lc_state = L2CAP_OPEN; 616 // XXX how to distinguish REconfiguration? 617 (*chan->lc_proto->connected)(chan->lc_upper); 618 } 619 } 620 goto out; 621 622 case L2CAP_UNACCEPTABLE_PARAMS: 623 /* 624 * Packet contains unacceptable parameters with preferred values 625 */ 626 while (left > 0) { 627 if (left < sizeof(opt)) 628 goto discon; 629 630 m_copydata(m, 0, sizeof(opt), &opt); 631 m_adj(m, sizeof(opt)); 632 left -= sizeof(opt); 633 634 if (left < opt.length) 635 goto discon; 636 637 switch (opt.type) { 638 case L2CAP_OPT_MTU: 639 if (opt.length != L2CAP_OPT_MTU_SIZE) 640 goto discon; 641 642 m_copydata(m, 0, L2CAP_OPT_MTU_SIZE, &val); 643 chan->lc_imtu = le16toh(val.mtu); 644 if (chan->lc_imtu < L2CAP_MTU_MINIMUM) 645 chan->lc_imtu = L2CAP_MTU_DEFAULT; 646 break; 647 648 case L2CAP_OPT_FLUSH_TIMO: 649 if (opt.length != L2CAP_OPT_FLUSH_TIMO_SIZE) 650 goto discon; 651 652 /* 653 * Spec says: If we cannot honor proposed value, 654 * either disconnect or try again with original 655 * value. I can't really see why they want to 656 * interfere with OUR flush timeout in any case 657 * so we just punt for now. 658 */ 659 goto discon; 660 661 case L2CAP_OPT_QOS: 662 break; 663 664 default: 665 UNKNOWN(opt.type); 666 goto discon; 667 } 668 669 m_adj(m, opt.length); 670 left -= opt.length; 671 } 672 673 if ((cp.flags & L2CAP_OPT_CFLAG_BIT) == 0) 674 l2cap_send_config_req(chan); // no state change 675 676 goto out; 677 678 case L2CAP_REJECT: 679 goto discon; 680 681 case L2CAP_UNKNOWN_OPTION: 682 /* 683 * Packet contains options not understood. Turn off unknown 684 * options by setting them to default values (means they will 685 * not be requested again). 686 * 687 * If our option was already off then fail (paranoia?) 688 * 689 * XXX Should we consider that options were set for a reason? 690 */ 691 while (left > 0) { 692 if (left < sizeof(opt)) 693 goto discon; 694 695 m_copydata(m, 0, sizeof(opt), &opt); 696 m_adj(m, sizeof(opt)); 697 left -= sizeof(opt); 698 699 if (left < opt.length) 700 goto discon; 701 702 m_adj(m, opt.length); 703 left -= opt.length; 704 705 switch(opt.type) { 706 case L2CAP_OPT_MTU: 707 if (chan->lc_imtu == L2CAP_MTU_DEFAULT) 708 goto discon; 709 710 chan->lc_imtu = L2CAP_MTU_DEFAULT; 711 break; 712 713 case L2CAP_OPT_FLUSH_TIMO: 714 if (chan->lc_flush == L2CAP_FLUSH_TIMO_DEFAULT) 715 goto discon; 716 717 chan->lc_flush = L2CAP_FLUSH_TIMO_DEFAULT; 718 break; 719 720 case L2CAP_OPT_QOS: 721 break; 722 723 default: 724 UNKNOWN(opt.type); 725 goto discon; 726 } 727 } 728 729 if ((cp.flags & L2CAP_OPT_CFLAG_BIT) == 0) 730 l2cap_send_config_req(chan); /* no state change */ 731 732 goto out; 733 734 default: 735 UNKNOWN(cp.result); 736 goto discon; 737 } 738 739 DPRINTF("how did I get here!?\n"); 740 741 discon: 742 l2cap_send_disconnect_req(chan); 743 l2cap_close(chan, ECONNABORTED); 744 745 out: 746 m_adj(m, left); 747 } 748 749 /* 750 * Process Received Disconnect Request. We must validate scid and dcid 751 * just in case but otherwise this connection is finished. 752 */ 753 static void 754 l2cap_recv_disconnect_req(struct mbuf *m, struct hci_link *link) 755 { 756 l2cap_cmd_hdr_t cmd; 757 l2cap_discon_req_cp cp; 758 l2cap_discon_rsp_cp rp; 759 struct l2cap_channel *chan; 760 761 m_copydata(m, 0, sizeof(cmd), &cmd); 762 m_adj(m, sizeof(cmd)); 763 764 m_copydata(m, 0, sizeof(cp), &cp); 765 m_adj(m, sizeof(cp)); 766 767 cp.scid = le16toh(cp.scid); 768 cp.dcid = le16toh(cp.dcid); 769 770 chan = l2cap_cid_lookup(cp.dcid); 771 if (chan == NULL || chan->lc_link != link || chan->lc_rcid != cp.scid) { 772 l2cap_send_command_rej(link, cmd.ident, L2CAP_REJ_INVALID_CID, 773 cp.dcid, cp.scid); 774 return; 775 } 776 777 rp.dcid = htole16(chan->lc_lcid); 778 rp.scid = htole16(chan->lc_rcid); 779 l2cap_send_signal(link, L2CAP_DISCONNECT_RSP, cmd.ident, 780 sizeof(rp), &rp); 781 782 if (chan->lc_state != L2CAP_CLOSED) 783 l2cap_close(chan, ECONNRESET); 784 } 785 786 /* 787 * Process Received Disconnect Response. We must validate scid and dcid but 788 * unless we were waiting for this signal, ignore it. 789 */ 790 static void 791 l2cap_recv_disconnect_rsp(struct mbuf *m, struct hci_link *link) 792 { 793 l2cap_cmd_hdr_t cmd; 794 l2cap_discon_rsp_cp cp; 795 struct l2cap_req *req; 796 struct l2cap_channel *chan; 797 798 m_copydata(m, 0, sizeof(cmd), &cmd); 799 m_adj(m, sizeof(cmd)); 800 801 m_copydata(m, 0, sizeof(cp), &cp); 802 m_adj(m, sizeof(cp)); 803 804 cp.scid = le16toh(cp.scid); 805 cp.dcid = le16toh(cp.dcid); 806 807 req = l2cap_request_lookup(link, cmd.ident); 808 if (req == NULL || req->lr_code != L2CAP_DISCONNECT_REQ) 809 return; 810 811 chan = req->lr_chan; 812 if (chan == NULL 813 || chan->lc_lcid != cp.scid 814 || chan->lc_rcid != cp.dcid) 815 return; 816 817 l2cap_request_free(req); 818 819 if (chan->lc_state != L2CAP_WAIT_DISCONNECT) 820 return; 821 822 l2cap_close(chan, 0); 823 } 824 825 /* 826 * Process Received Info Request. We must respond but alas dont 827 * support anything as yet so thats easy. 828 */ 829 static void 830 l2cap_recv_info_req(struct mbuf *m, struct hci_link *link) 831 { 832 l2cap_cmd_hdr_t cmd; 833 l2cap_info_req_cp cp; 834 l2cap_info_rsp_cp rp; 835 836 m_copydata(m, 0, sizeof(cmd), &cmd); 837 m_adj(m, sizeof(cmd)); 838 839 m_copydata(m, 0, sizeof(cp), &cp); 840 m_adj(m, sizeof(cp)); 841 842 switch(le16toh(cp.type)) { 843 case L2CAP_CONNLESS_MTU: 844 case L2CAP_EXTENDED_FEATURES: 845 default: 846 rp.type = cp.type; 847 rp.result = htole16(L2CAP_NOT_SUPPORTED); 848 849 l2cap_send_signal(link, L2CAP_INFO_RSP, cmd.ident, 850 sizeof(rp), &rp); 851 break; 852 } 853 } 854 855 /* 856 * Construct signal and wrap in C-Frame for link. 857 */ 858 static int 859 l2cap_send_signal(struct hci_link *link, uint8_t code, uint8_t ident, 860 uint16_t length, void *data) 861 { 862 struct mbuf *m; 863 l2cap_hdr_t *hdr; 864 l2cap_cmd_hdr_t *cmd; 865 866 #ifdef DIAGNOSTIC 867 if (link == NULL) 868 return ENETDOWN; 869 870 if (sizeof(l2cap_cmd_hdr_t) + length > link->hl_mtu) 871 printf("(%s) exceeding L2CAP Signal MTU for link!\n", 872 link->hl_unit->hci_devname); 873 #endif 874 875 m = m_gethdr(M_DONTWAIT, MT_DATA); 876 if (m == NULL) 877 return ENOMEM; 878 879 hdr = mtod(m, l2cap_hdr_t *); 880 cmd = (l2cap_cmd_hdr_t *)(hdr + 1); 881 882 m->m_len = m->m_pkthdr.len = MHLEN; 883 884 /* Command Data */ 885 if (length > 0) 886 m_copyback(m, sizeof(hdr) + sizeof(cmd), length, data); 887 888 /* Command Header */ 889 cmd->code = code; 890 cmd->ident = ident; 891 cmd->length = htole16(length); 892 length += sizeof(cmd); 893 894 /* C-Frame Header */ 895 hdr->length = htole16(length); 896 hdr->dcid = htole16(L2CAP_SIGNAL_CID); 897 length += sizeof(hdr); 898 899 if (m->m_pkthdr.len != MAX(MHLEN, length)) { 900 m_freem(m); 901 return ENOMEM; 902 } 903 904 m->m_pkthdr.len = length; 905 m->m_len = MIN(length, MHLEN); 906 907 DPRINTFN(2, "(%s) code %d, ident %d, len %d\n", 908 link->hl_unit->hci_devname, code, ident, length); 909 910 return hci_acl_send(m, link, NULL); 911 } 912 913 /* 914 * Send Command Reject packet. 915 */ 916 static int 917 l2cap_send_command_rej(struct hci_link *link, uint8_t ident, 918 uint16_t reason, ...) 919 { 920 l2cap_cmd_rej_cp cp; 921 int len = 0; 922 va_list ap; 923 924 va_start(ap, reason); 925 926 cp.reason = htole16(reason); 927 928 switch (reason) { 929 case L2CAP_REJ_NOT_UNDERSTOOD: 930 len = 2; 931 break; 932 933 case L2CAP_REJ_MTU_EXCEEDED: 934 len = 4; 935 cp.data[0] = va_arg(ap, int); /* SigMTU */ 936 cp.data[0] = htole16(cp.data[0]); 937 break; 938 939 case L2CAP_REJ_INVALID_CID: 940 len = 6; 941 cp.data[0] = va_arg(ap, int); /* dcid */ 942 cp.data[0] = htole16(cp.data[0]); 943 cp.data[1] = va_arg(ap, int); /* scid */ 944 cp.data[1] = htole16(cp.data[1]); 945 break; 946 947 default: 948 UNKNOWN(reason); 949 return EINVAL; 950 } 951 952 va_end(ap); 953 954 return l2cap_send_signal(link, L2CAP_COMMAND_REJ, ident, len, &cp); 955 } 956 957 /* 958 * Send Connect Request 959 */ 960 int 961 l2cap_send_connect_req(struct l2cap_channel *chan) 962 { 963 l2cap_con_req_cp cp; 964 int err; 965 966 err = l2cap_request_alloc(chan, L2CAP_CONNECT_REQ); 967 if (err) 968 return err; 969 970 cp.psm = htole16(chan->lc_raddr.bt_psm); 971 cp.scid = htole16(chan->lc_lcid); 972 973 return l2cap_send_signal(chan->lc_link, L2CAP_CONNECT_REQ, 974 chan->lc_link->hl_lastid, sizeof(cp), &cp); 975 } 976 977 /* 978 * Send Config Request 979 * 980 * For outgoing config request, we only put options in the packet if they 981 * differ from the default and would have to be actioned. We dont support 982 * enough option types to make overflowing SigMTU an issue so it can all 983 * go in one packet. 984 */ 985 int 986 l2cap_send_config_req(struct l2cap_channel *chan) 987 { 988 l2cap_cfg_req_cp *cp; 989 l2cap_cfg_opt_t *opt; 990 l2cap_cfg_opt_val_t *val; 991 uint8_t *next, buf[L2CAP_MTU_MINIMUM]; 992 int err; 993 994 err = l2cap_request_alloc(chan, L2CAP_CONFIG_REQ); 995 if (err) 996 return err; 997 998 /* Config Header (4 octets) */ 999 cp = (l2cap_cfg_req_cp *)buf; 1000 cp->dcid = htole16(chan->lc_rcid); 1001 cp->flags = 0; /* "No Continuation" */ 1002 1003 next = buf + sizeof(l2cap_cfg_req_cp); 1004 1005 /* Incoming MTU (4 octets) */ 1006 if (chan->lc_imtu != L2CAP_MTU_DEFAULT) { 1007 opt = (l2cap_cfg_opt_t *)next; 1008 opt->type = L2CAP_OPT_MTU; 1009 opt->length = L2CAP_OPT_MTU_SIZE; 1010 1011 val = (l2cap_cfg_opt_val_t *)(opt + 1); 1012 val->mtu = htole16(chan->lc_imtu); 1013 1014 next += sizeof(l2cap_cfg_opt_t) + L2CAP_OPT_MTU_SIZE; 1015 } 1016 1017 /* Flush Timeout (4 octets) */ 1018 if (chan->lc_flush != L2CAP_FLUSH_TIMO_DEFAULT) { 1019 opt = (l2cap_cfg_opt_t *)next; 1020 opt->type = L2CAP_OPT_FLUSH_TIMO; 1021 opt->length = L2CAP_OPT_FLUSH_TIMO_SIZE; 1022 1023 val = (l2cap_cfg_opt_val_t *)(opt + 1); 1024 val->flush_timo = htole16(chan->lc_flush); 1025 1026 next += sizeof(l2cap_cfg_opt_t) + L2CAP_OPT_FLUSH_TIMO_SIZE; 1027 } 1028 1029 /* Outgoing QoS Flow (24 octets) */ 1030 /* Retransmission & Flow Control (11 octets) */ 1031 /* 1032 * From here we need to start paying attention to SigMTU as we have 1033 * possibly overflowed the minimum supported.. 1034 */ 1035 1036 return l2cap_send_signal(chan->lc_link, L2CAP_CONFIG_REQ, 1037 chan->lc_link->hl_lastid, (int)(next - buf), buf); 1038 } 1039 1040 /* 1041 * Send Disconnect Request 1042 */ 1043 int 1044 l2cap_send_disconnect_req(struct l2cap_channel *chan) 1045 { 1046 l2cap_discon_req_cp cp; 1047 int err; 1048 1049 err = l2cap_request_alloc(chan, L2CAP_DISCONNECT_REQ); 1050 if (err) 1051 return err; 1052 1053 cp.dcid = htole16(chan->lc_rcid); 1054 cp.scid = htole16(chan->lc_lcid); 1055 1056 return l2cap_send_signal(chan->lc_link, L2CAP_DISCONNECT_REQ, 1057 chan->lc_link->hl_lastid, sizeof(cp), &cp); 1058 } 1059
Indexes created Thu Sep 25 02:09:54 GMT 2025