l2cap_signal.c revision 1.3
1 /* $NetBSD: l2cap_signal.c,v 1.3 2006/12/07 21:36:27 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 1.3 2006/12/07 21:36:27 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_state & L2CAP_WAIT_CONFIG_REQ) == 0) { 408 l2cap_send_command_rej(link, cmd.ident, L2CAP_REJ_INVALID_CID, 409 L2CAP_NULL_CID, cp.dcid); 410 goto out; 411 } 412 413 /* ready our response packet */ 414 rp.scid = htole16(chan->lc_rcid); 415 rp.flags = 0; /* "No Continuation" */ 416 rp.result = L2CAP_SUCCESS; 417 len = sizeof(rp); 418 419 /* 420 * Process the packet. We build the return packet on the fly adding any 421 * unacceptable parameters as we go. As we can only return one result, 422 * unknown option takes precedence so we start our return packet anew 423 * and ignore option values thereafter as they will be re-sent. 424 * 425 * Since we do not support enough options to make overflowing the min 426 * MTU size an issue in normal use, we just reject config requests that 427 * make that happen. This could be because options are repeated or the 428 * packet is corrupted in some way. 429 * 430 * If unknown option types threaten to overflow the packet, we just 431 * ignore them. We can deny them next time. 432 */ 433 while (left > 0) { 434 if (left < sizeof(opt)) 435 goto reject; 436 437 m_copydata(m, 0, sizeof(opt), &opt); 438 m_adj(m, sizeof(opt)); 439 left -= sizeof(opt); 440 441 if (left < opt.length) 442 goto reject; 443 444 switch(opt.type & L2CAP_OPT_HINT_MASK) { 445 case L2CAP_OPT_MTU: 446 if (rp.result == L2CAP_UNKNOWN_OPTION) 447 break; 448 449 if (opt.length != L2CAP_OPT_MTU_SIZE) 450 goto reject; 451 452 m_copydata(m, 0, L2CAP_OPT_MTU_SIZE, &val); 453 val.mtu = le16toh(val.mtu); 454 455 /* 456 * XXX how do we know what the minimum acceptable MTU is 457 * for a channel? Spec says some profiles have a higher 458 * minimum but I have no way to find that out at this 459 * juncture.. 460 */ 461 if (val.mtu < L2CAP_MTU_MINIMUM) { 462 if (len + sizeof(opt) + L2CAP_OPT_MTU_SIZE > sizeof(buf)) 463 goto reject; 464 465 rp.result = L2CAP_UNACCEPTABLE_PARAMS; 466 memcpy(buf + len, &opt, sizeof(opt)); 467 len += sizeof(opt); 468 val.mtu = htole16(L2CAP_MTU_MINIMUM); 469 memcpy(buf + len, &val, L2CAP_OPT_MTU_SIZE); 470 len += L2CAP_OPT_MTU_SIZE; 471 } else 472 chan->lc_omtu = val.mtu; 473 474 break; 475 476 case L2CAP_OPT_FLUSH_TIMO: 477 if (rp.result == L2CAP_UNKNOWN_OPTION) 478 break; 479 480 if (opt.length != L2CAP_OPT_FLUSH_TIMO_SIZE) 481 goto reject; 482 483 /* 484 * I think that this is informational only - he is 485 * informing us of the flush timeout he will be using. 486 * I dont think this affects us in any significant way, 487 * so just ignore this value for now. 488 */ 489 break; 490 491 case L2CAP_OPT_QOS: 492 default: 493 /* ignore hints */ 494 if (opt.type & L2CAP_OPT_HINT_BIT) 495 break; 496 497 /* unknown options supercede all else */ 498 if (rp.result != L2CAP_UNKNOWN_OPTION) { 499 rp.result = L2CAP_UNKNOWN_OPTION; 500 len = sizeof(rp); 501 } 502 503 /* ignore if it don't fit */ 504 if (len + sizeof(opt) > sizeof(buf)) 505 break; 506 507 /* return unknown option type, but no data */ 508 buf[len++] = opt.type; 509 buf[len++] = 0; 510 break; 511 } 512 513 m_adj(m, opt.length); 514 left -= opt.length; 515 } 516 517 rp.result = htole16(rp.result); 518 memcpy(buf, &rp, sizeof(rp)); 519 l2cap_send_signal(link, L2CAP_CONFIG_RSP, cmd.ident, len, buf); 520 521 if ((cp.flags & L2CAP_OPT_CFLAG_BIT) == 0 522 && rp.result == le16toh(L2CAP_SUCCESS)) { 523 524 chan->lc_state &= ~L2CAP_WAIT_CONFIG_REQ; 525 526 if ((chan->lc_state & L2CAP_WAIT_CONFIG_RSP) == 0) { 527 chan->lc_state = L2CAP_OPEN; 528 // XXX how to distinguish REconfiguration? 529 (*chan->lc_proto->connected)(chan->lc_upper); 530 } 531 } 532 return; 533 534 reject: 535 l2cap_send_command_rej(link, cmd.ident, L2CAP_REJ_NOT_UNDERSTOOD); 536 out: 537 m_adj(m, left); 538 } 539 540 /* 541 * Process Received Config Response. 542 */ 543 static void 544 l2cap_recv_config_rsp(struct mbuf *m, struct hci_link *link) 545 { 546 l2cap_cmd_hdr_t cmd; 547 l2cap_cfg_rsp_cp cp; 548 l2cap_cfg_opt_t opt; 549 l2cap_cfg_opt_val_t val; 550 struct l2cap_req *req; 551 struct l2cap_channel *chan; 552 int left; 553 554 m_copydata(m, 0, sizeof(cmd), &cmd); 555 m_adj(m, sizeof(cmd)); 556 left = le16toh(cmd.length); 557 558 if (left < sizeof(cp)) 559 goto out; 560 561 m_copydata(m, 0, sizeof(cp), &cp); 562 m_adj(m, sizeof(cp)); 563 left -= sizeof(cp); 564 565 cp.scid = le16toh(cp.scid); 566 cp.flags = le16toh(cp.flags); 567 cp.result = le16toh(cp.result); 568 569 req = l2cap_request_lookup(link, cmd.ident); 570 if (req == NULL || req->lr_code != L2CAP_CONFIG_REQ) 571 goto out; 572 573 chan = req->lr_chan; 574 if (chan != NULL && chan->lc_lcid != cp.scid) 575 goto out; 576 577 l2cap_request_free(req); 578 579 if (chan == NULL || (chan->lc_state & L2CAP_WAIT_CONFIG_RSP) == 0) 580 goto out; 581 582 if ((cp.flags & L2CAP_OPT_CFLAG_BIT)) { 583 l2cap_cfg_req_cp rp; 584 585 /* 586 * They have more to tell us and want another ID to 587 * use, so send an empty config request 588 */ 589 if (l2cap_request_alloc(chan, L2CAP_CONFIG_REQ)) 590 goto discon; 591 592 rp.dcid = htole16(cp.scid); 593 rp.flags = 0; 594 595 if (l2cap_send_signal(link, L2CAP_CONFIG_REQ, link->hl_lastid, 596 sizeof(rp), &rp)) 597 goto discon; 598 } 599 600 switch(cp.result) { 601 case L2CAP_SUCCESS: 602 /* 603 * If continuation flag was not set, our config request was 604 * accepted. We may have to wait for their config request to 605 * complete, so check that but otherwise we are open 606 * 607 * There may be 'advisory' values in the packet but we just 608 * ignore those.. 609 */ 610 if ((cp.flags & L2CAP_OPT_CFLAG_BIT) == 0) { 611 chan->lc_state &= ~L2CAP_WAIT_CONFIG_RSP; 612 613 if ((chan->lc_state & L2CAP_WAIT_CONFIG_REQ) == 0) { 614 chan->lc_state = L2CAP_OPEN; 615 // XXX how to distinguish REconfiguration? 616 (*chan->lc_proto->connected)(chan->lc_upper); 617 } 618 } 619 goto out; 620 621 case L2CAP_UNACCEPTABLE_PARAMS: 622 /* 623 * Packet contains unacceptable parameters with preferred values 624 */ 625 while (left > 0) { 626 if (left < sizeof(opt)) 627 goto discon; 628 629 m_copydata(m, 0, sizeof(opt), &opt); 630 m_adj(m, sizeof(opt)); 631 left -= sizeof(opt); 632 633 if (left < opt.length) 634 goto discon; 635 636 switch (opt.type) { 637 case L2CAP_OPT_MTU: 638 if (opt.length != L2CAP_OPT_MTU_SIZE) 639 goto discon; 640 641 m_copydata(m, 0, L2CAP_OPT_MTU_SIZE, &val); 642 chan->lc_imtu = le16toh(val.mtu); 643 if (chan->lc_imtu < L2CAP_MTU_MINIMUM) 644 chan->lc_imtu = L2CAP_MTU_DEFAULT; 645 break; 646 647 case L2CAP_OPT_FLUSH_TIMO: 648 if (opt.length != L2CAP_OPT_FLUSH_TIMO_SIZE) 649 goto discon; 650 651 /* 652 * Spec says: If we cannot honor proposed value, 653 * either disconnect or try again with original 654 * value. I can't really see why they want to 655 * interfere with OUR flush timeout in any case 656 * so we just punt for now. 657 */ 658 goto discon; 659 660 case L2CAP_OPT_QOS: 661 break; 662 663 default: 664 UNKNOWN(opt.type); 665 goto discon; 666 } 667 668 m_adj(m, opt.length); 669 left -= opt.length; 670 } 671 672 if ((cp.flags & L2CAP_OPT_CFLAG_BIT) == 0) 673 l2cap_send_config_req(chan); // no state change 674 675 goto out; 676 677 case L2CAP_REJECT: 678 goto discon; 679 680 case L2CAP_UNKNOWN_OPTION: 681 /* 682 * Packet contains options not understood. Turn off unknown 683 * options by setting them to default values (means they will 684 * not be requested again). 685 * 686 * If our option was already off then fail (paranoia?) 687 * 688 * XXX Should we consider that options were set for a reason? 689 */ 690 while (left > 0) { 691 if (left < sizeof(opt)) 692 goto discon; 693 694 m_copydata(m, 0, sizeof(opt), &opt); 695 m_adj(m, sizeof(opt)); 696 left -= sizeof(opt); 697 698 if (left < opt.length) 699 goto discon; 700 701 m_adj(m, opt.length); 702 left -= opt.length; 703 704 switch(opt.type) { 705 case L2CAP_OPT_MTU: 706 if (chan->lc_imtu == L2CAP_MTU_DEFAULT) 707 goto discon; 708 709 chan->lc_imtu = L2CAP_MTU_DEFAULT; 710 break; 711 712 case L2CAP_OPT_FLUSH_TIMO: 713 if (chan->lc_flush == L2CAP_FLUSH_TIMO_DEFAULT) 714 goto discon; 715 716 chan->lc_flush = L2CAP_FLUSH_TIMO_DEFAULT; 717 break; 718 719 case L2CAP_OPT_QOS: 720 break; 721 722 default: 723 UNKNOWN(opt.type); 724 goto discon; 725 } 726 } 727 728 if ((cp.flags & L2CAP_OPT_CFLAG_BIT) == 0) 729 l2cap_send_config_req(chan); /* no state change */ 730 731 goto out; 732 733 default: 734 UNKNOWN(cp.result); 735 goto discon; 736 } 737 738 DPRINTF("how did I get here!?\n"); 739 740 discon: 741 l2cap_send_disconnect_req(chan); 742 l2cap_close(chan, ECONNABORTED); 743 744 out: 745 m_adj(m, left); 746 } 747 748 /* 749 * Process Received Disconnect Request. We must validate scid and dcid 750 * just in case but otherwise this connection is finished. 751 */ 752 static void 753 l2cap_recv_disconnect_req(struct mbuf *m, struct hci_link *link) 754 { 755 l2cap_cmd_hdr_t cmd; 756 l2cap_discon_req_cp cp; 757 l2cap_discon_rsp_cp rp; 758 struct l2cap_channel *chan; 759 760 m_copydata(m, 0, sizeof(cmd), &cmd); 761 m_adj(m, sizeof(cmd)); 762 763 m_copydata(m, 0, sizeof(cp), &cp); 764 m_adj(m, sizeof(cp)); 765 766 cp.scid = le16toh(cp.scid); 767 cp.dcid = le16toh(cp.dcid); 768 769 chan = l2cap_cid_lookup(cp.dcid); 770 if (chan == NULL || chan->lc_rcid != cp.scid) { 771 l2cap_send_command_rej(link, cmd.ident, L2CAP_REJ_INVALID_CID, 772 cp.dcid, cp.scid); 773 return; 774 } 775 776 rp.dcid = htole16(chan->lc_lcid); 777 rp.scid = htole16(chan->lc_rcid); 778 l2cap_send_signal(link, L2CAP_DISCONNECT_RSP, cmd.ident, 779 sizeof(rp), &rp); 780 781 if (chan->lc_state != L2CAP_CLOSED) 782 l2cap_close(chan, ECONNRESET); 783 } 784 785 /* 786 * Process Received Disconnect Response. We must validate scid and dcid but 787 * unless we were waiting for this signal, ignore it. 788 */ 789 static void 790 l2cap_recv_disconnect_rsp(struct mbuf *m, struct hci_link *link) 791 { 792 l2cap_cmd_hdr_t cmd; 793 l2cap_discon_rsp_cp cp; 794 struct l2cap_req *req; 795 struct l2cap_channel *chan; 796 797 m_copydata(m, 0, sizeof(cmd), &cmd); 798 m_adj(m, sizeof(cmd)); 799 800 m_copydata(m, 0, sizeof(cp), &cp); 801 m_adj(m, sizeof(cp)); 802 803 cp.scid = le16toh(cp.scid); 804 cp.dcid = le16toh(cp.dcid); 805 806 req = l2cap_request_lookup(link, cmd.ident); 807 if (req == NULL || req->lr_code != L2CAP_DISCONNECT_REQ) 808 return; 809 810 chan = req->lr_chan; 811 if (chan == NULL 812 || chan->lc_lcid != cp.scid 813 || chan->lc_rcid != cp.dcid) 814 return; 815 816 l2cap_request_free(req); 817 818 if (chan->lc_state != L2CAP_WAIT_DISCONNECT) 819 return; 820 821 l2cap_close(chan, 0); 822 } 823 824 /* 825 * Process Received Info Request. We must respond but alas dont 826 * support anything as yet so thats easy. 827 */ 828 static void 829 l2cap_recv_info_req(struct mbuf *m, struct hci_link *link) 830 { 831 l2cap_cmd_hdr_t cmd; 832 l2cap_info_req_cp cp; 833 l2cap_info_rsp_cp rp; 834 835 m_copydata(m, 0, sizeof(cmd), &cmd); 836 m_adj(m, sizeof(cmd)); 837 838 m_copydata(m, 0, sizeof(cp), &cp); 839 m_adj(m, sizeof(cp)); 840 841 switch(le16toh(cp.type)) { 842 case L2CAP_CONNLESS_MTU: 843 case L2CAP_EXTENDED_FEATURES: 844 default: 845 rp.type = cp.type; 846 rp.result = htole16(L2CAP_NOT_SUPPORTED); 847 848 l2cap_send_signal(link, L2CAP_INFO_RSP, cmd.ident, 849 sizeof(rp), &rp); 850 break; 851 } 852 } 853 854 /* 855 * Construct signal and wrap in C-Frame for link. 856 */ 857 static int 858 l2cap_send_signal(struct hci_link *link, uint8_t code, uint8_t ident, 859 uint16_t length, void *data) 860 { 861 struct mbuf *m; 862 l2cap_hdr_t *hdr; 863 l2cap_cmd_hdr_t *cmd; 864 865 #ifdef DIAGNOSTIC 866 if (link == NULL) 867 return ENETDOWN; 868 869 if (sizeof(l2cap_cmd_hdr_t) + length > link->hl_mtu) 870 printf("(%s) exceeding L2CAP Signal MTU for link!\n", 871 link->hl_unit->hci_devname); 872 #endif 873 874 m = m_gethdr(M_DONTWAIT, MT_DATA); 875 if (m == NULL) 876 return ENOMEM; 877 878 hdr = mtod(m, l2cap_hdr_t *); 879 cmd = (l2cap_cmd_hdr_t *)(hdr + 1); 880 881 m->m_len = m->m_pkthdr.len = MHLEN; 882 883 /* Command Data */ 884 if (length > 0) 885 m_copyback(m, sizeof(hdr) + sizeof(cmd), length, data); 886 887 /* Command Header */ 888 cmd->code = code; 889 cmd->ident = ident; 890 cmd->length = htole16(length); 891 length += sizeof(cmd); 892 893 /* C-Frame Header */ 894 hdr->length = htole16(length); 895 hdr->dcid = htole16(L2CAP_SIGNAL_CID); 896 length += sizeof(hdr); 897 898 if (m->m_pkthdr.len != MAX(MHLEN, length)) { 899 m_freem(m); 900 return ENOMEM; 901 } 902 903 m->m_pkthdr.len = length; 904 m->m_len = MIN(length, MHLEN); 905 906 DPRINTFN(2, "(%s) code %d, ident %d, len %d\n", 907 link->hl_unit->hci_devname, code, ident, length); 908 909 return hci_acl_send(m, link, NULL); 910 } 911 912 /* 913 * Send Command Reject packet. 914 */ 915 static int 916 l2cap_send_command_rej(struct hci_link *link, uint8_t ident, 917 uint16_t reason, ...) 918 { 919 l2cap_cmd_rej_cp cp; 920 int len = 0; 921 va_list ap; 922 923 va_start(ap, reason); 924 925 cp.reason = htole16(reason); 926 927 switch (reason) { 928 case L2CAP_REJ_NOT_UNDERSTOOD: 929 len = 2; 930 break; 931 932 case L2CAP_REJ_MTU_EXCEEDED: 933 len = 4; 934 cp.data[0] = va_arg(ap, int); /* SigMTU */ 935 cp.data[0] = htole16(cp.data[0]); 936 break; 937 938 case L2CAP_REJ_INVALID_CID: 939 len = 6; 940 cp.data[0] = va_arg(ap, int); /* dcid */ 941 cp.data[0] = htole16(cp.data[0]); 942 cp.data[1] = va_arg(ap, int); /* scid */ 943 cp.data[1] = htole16(cp.data[1]); 944 break; 945 946 default: 947 UNKNOWN(reason); 948 return EINVAL; 949 } 950 951 va_end(ap); 952 953 return l2cap_send_signal(link, L2CAP_COMMAND_REJ, ident, len, &cp); 954 } 955 956 /* 957 * Send Connect Request 958 */ 959 int 960 l2cap_send_connect_req(struct l2cap_channel *chan) 961 { 962 l2cap_con_req_cp cp; 963 int err; 964 965 err = l2cap_request_alloc(chan, L2CAP_CONNECT_REQ); 966 if (err) 967 return err; 968 969 cp.psm = htole16(chan->lc_raddr.bt_psm); 970 cp.scid = htole16(chan->lc_lcid); 971 972 return l2cap_send_signal(chan->lc_link, L2CAP_CONNECT_REQ, 973 chan->lc_link->hl_lastid, sizeof(cp), &cp); 974 } 975 976 /* 977 * Send Config Request 978 * 979 * For outgoing config request, we only put options in the packet if they 980 * differ from the default and would have to be actioned. We dont support 981 * enough option types to make overflowing SigMTU an issue so it can all 982 * go in one packet. 983 */ 984 int 985 l2cap_send_config_req(struct l2cap_channel *chan) 986 { 987 l2cap_cfg_req_cp *cp; 988 l2cap_cfg_opt_t *opt; 989 l2cap_cfg_opt_val_t *val; 990 uint8_t *next, buf[L2CAP_MTU_MINIMUM]; 991 int err; 992 993 err = l2cap_request_alloc(chan, L2CAP_CONFIG_REQ); 994 if (err) 995 return err; 996 997 /* Config Header (4 octets) */ 998 cp = (l2cap_cfg_req_cp *)buf; 999 cp->dcid = htole16(chan->lc_rcid); 1000 cp->flags = 0; /* "No Continuation" */ 1001 1002 next = buf + sizeof(l2cap_cfg_req_cp); 1003 1004 /* Incoming MTU (4 octets) */ 1005 if (chan->lc_imtu != L2CAP_MTU_DEFAULT) { 1006 opt = (l2cap_cfg_opt_t *)next; 1007 opt->type = L2CAP_OPT_MTU; 1008 opt->length = L2CAP_OPT_MTU_SIZE; 1009 1010 val = (l2cap_cfg_opt_val_t *)(opt + 1); 1011 val->mtu = htole16(chan->lc_imtu); 1012 1013 next += sizeof(l2cap_cfg_opt_t) + L2CAP_OPT_MTU_SIZE; 1014 } 1015 1016 /* Flush Timeout (4 octets) */ 1017 if (chan->lc_flush != L2CAP_FLUSH_TIMO_DEFAULT) { 1018 opt = (l2cap_cfg_opt_t *)next; 1019 opt->type = L2CAP_OPT_FLUSH_TIMO; 1020 opt->length = L2CAP_OPT_FLUSH_TIMO_SIZE; 1021 1022 val = (l2cap_cfg_opt_val_t *)(opt + 1); 1023 val->flush_timo = htole16(chan->lc_flush); 1024 1025 next += sizeof(l2cap_cfg_opt_t) + L2CAP_OPT_FLUSH_TIMO_SIZE; 1026 } 1027 1028 /* Outgoing QoS Flow (24 octets) */ 1029 /* Retransmission & Flow Control (11 octets) */ 1030 /* 1031 * From here we need to start paying attention to SigMTU as we have 1032 * possibly overflowed the minimum supported.. 1033 */ 1034 1035 return l2cap_send_signal(chan->lc_link, L2CAP_CONFIG_REQ, 1036 chan->lc_link->hl_lastid, (int)(next - buf), buf); 1037 } 1038 1039 /* 1040 * Send Disconnect Request 1041 */ 1042 int 1043 l2cap_send_disconnect_req(struct l2cap_channel *chan) 1044 { 1045 l2cap_discon_req_cp cp; 1046 int err; 1047 1048 err = l2cap_request_alloc(chan, L2CAP_DISCONNECT_REQ); 1049 if (err) 1050 return err; 1051 1052 cp.dcid = htole16(chan->lc_rcid); 1053 cp.scid = htole16(chan->lc_lcid); 1054 1055 return l2cap_send_signal(chan->lc_link, L2CAP_DISCONNECT_REQ, 1056 chan->lc_link->hl_lastid, sizeof(cp), &cp); 1057 } 1058
Indexes created Fri Sep 26 20:09:58 GMT 2025