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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 | // SPDX-License-Identifier: GPL-2.0-only /* * shdlc Link Layer Control * * Copyright (C) 2012 Intel Corporation. All rights reserved. */ #define pr_fmt(fmt) "shdlc: %s: " fmt, __func__ #include <linux/types.h> #include <linux/sched.h> #include <linux/wait.h> #include <linux/slab.h> #include <linux/skbuff.h> #include "llc.h" enum shdlc_state { SHDLC_DISCONNECTED = 0, SHDLC_CONNECTING = 1, SHDLC_NEGOTIATING = 2, SHDLC_HALF_CONNECTED = 3, SHDLC_CONNECTED = 4 }; struct llc_shdlc { struct nfc_hci_dev *hdev; xmit_to_drv_t xmit_to_drv; rcv_to_hci_t rcv_to_hci; struct mutex state_mutex; enum shdlc_state state; int hard_fault; wait_queue_head_t *connect_wq; int connect_tries; int connect_result; struct timer_list connect_timer;/* aka T3 in spec 10.6.1 */ u8 w; /* window size */ bool srej_support; struct timer_list t1_timer; /* send ack timeout */ bool t1_active; struct timer_list t2_timer; /* guard/retransmit timeout */ bool t2_active; int ns; /* next seq num for send */ int nr; /* next expected seq num for receive */ int dnr; /* oldest sent unacked seq num */ struct sk_buff_head rcv_q; struct sk_buff_head send_q; bool rnr; /* other side is not ready to receive */ struct sk_buff_head ack_pending_q; struct work_struct sm_work; int tx_headroom; int tx_tailroom; llc_failure_t llc_failure; }; #define SHDLC_LLC_HEAD_ROOM 2 #define SHDLC_MAX_WINDOW 4 #define SHDLC_SREJ_SUPPORT false #define SHDLC_CONTROL_HEAD_MASK 0xe0 #define SHDLC_CONTROL_HEAD_I 0x80 #define SHDLC_CONTROL_HEAD_I2 0xa0 #define SHDLC_CONTROL_HEAD_S 0xc0 #define SHDLC_CONTROL_HEAD_U 0xe0 #define SHDLC_CONTROL_NS_MASK 0x38 #define SHDLC_CONTROL_NR_MASK 0x07 #define SHDLC_CONTROL_TYPE_MASK 0x18 #define SHDLC_CONTROL_M_MASK 0x1f enum sframe_type { S_FRAME_RR = 0x00, S_FRAME_REJ = 0x01, S_FRAME_RNR = 0x02, S_FRAME_SREJ = 0x03 }; enum uframe_modifier { U_FRAME_UA = 0x06, U_FRAME_RSET = 0x19 }; #define SHDLC_CONNECT_VALUE_MS 5 #define SHDLC_T1_VALUE_MS(w) ((5 * w) / 4) #define SHDLC_T2_VALUE_MS 300 #define SHDLC_DUMP_SKB(info, skb) \ do { \ pr_debug("%s:\n", info); \ print_hex_dump(KERN_DEBUG, "shdlc: ", DUMP_PREFIX_OFFSET, \ 16, 1, skb->data, skb->len, 0); \ } while (0) /* checks x < y <= z modulo 8 */ static bool llc_shdlc_x_lt_y_lteq_z(int x, int y, int z) { if (x < z) return ((x < y) && (y <= z)) ? true : false; else return ((y > x) || (y <= z)) ? true : false; } /* checks x <= y < z modulo 8 */ static bool llc_shdlc_x_lteq_y_lt_z(int x, int y, int z) { if (x <= z) return ((x <= y) && (y < z)) ? true : false; else /* x > z -> z+8 > x */ return ((y >= x) || (y < z)) ? true : false; } static struct sk_buff *llc_shdlc_alloc_skb(const struct llc_shdlc *shdlc, int payload_len) { struct sk_buff *skb; skb = alloc_skb(shdlc->tx_headroom + SHDLC_LLC_HEAD_ROOM + shdlc->tx_tailroom + payload_len, GFP_KERNEL); if (skb) skb_reserve(skb, shdlc->tx_headroom + SHDLC_LLC_HEAD_ROOM); return skb; } /* immediately sends an S frame. */ static int llc_shdlc_send_s_frame(const struct llc_shdlc *shdlc, enum sframe_type sframe_type, int nr) { int r; struct sk_buff *skb; pr_debug("sframe_type=%d nr=%d\n", sframe_type, nr); skb = llc_shdlc_alloc_skb(shdlc, 0); if (skb == NULL) return -ENOMEM; *(u8 *)skb_push(skb, 1) = SHDLC_CONTROL_HEAD_S | (sframe_type << 3) | nr; r = shdlc->xmit_to_drv(shdlc->hdev, skb); kfree_skb(skb); return r; } /* immediately sends an U frame. skb may contain optional payload */ static int llc_shdlc_send_u_frame(const struct llc_shdlc *shdlc, struct sk_buff *skb, enum uframe_modifier uframe_modifier) { int r; pr_debug("uframe_modifier=%d\n", uframe_modifier); *(u8 *)skb_push(skb, 1) = SHDLC_CONTROL_HEAD_U | uframe_modifier; r = shdlc->xmit_to_drv(shdlc->hdev, skb); kfree_skb(skb); return r; } /* * Free ack_pending frames until y_nr - 1, and reset t2 according to * the remaining oldest ack_pending frame sent time */ static void llc_shdlc_reset_t2(struct llc_shdlc *shdlc, int y_nr) { struct sk_buff *skb; int dnr = shdlc->dnr; /* MUST initially be < y_nr */ pr_debug("release ack pending up to frame %d excluded\n", y_nr); while (dnr != y_nr) { pr_debug("release ack pending frame %d\n", dnr); skb = skb_dequeue(&shdlc->ack_pending_q); kfree_skb(skb); dnr = (dnr + 1) % 8; } if (skb_queue_empty(&shdlc->ack_pending_q)) { if (shdlc->t2_active) { del_timer_sync(&shdlc->t2_timer); shdlc->t2_active = false; pr_debug("All sent frames acked. Stopped T2(retransmit)\n"); } } else { skb = skb_peek(&shdlc->ack_pending_q); mod_timer(&shdlc->t2_timer, *(unsigned long *)skb->cb + msecs_to_jiffies(SHDLC_T2_VALUE_MS)); shdlc->t2_active = true; pr_debug("Start T2(retransmit) for remaining unacked sent frames\n"); } } /* * Receive validated frames from lower layer. skb contains HCI payload only. * Handle according to algorithm at spec:10.8.2 */ static void llc_shdlc_rcv_i_frame(struct llc_shdlc *shdlc, struct sk_buff *skb, int ns, int nr) { int x_ns = ns; int y_nr = nr; pr_debug("recvd I-frame %d, remote waiting frame %d\n", ns, nr); if (shdlc->state != SHDLC_CONNECTED) goto exit; if (x_ns != shdlc->nr) { llc_shdlc_send_s_frame(shdlc, S_FRAME_REJ, shdlc->nr); goto exit; } if (!shdlc->t1_active) { shdlc->t1_active = true; mod_timer(&shdlc->t1_timer, jiffies + msecs_to_jiffies(SHDLC_T1_VALUE_MS(shdlc->w))); pr_debug("(re)Start T1(send ack)\n"); } if (skb->len) { shdlc->rcv_to_hci(shdlc->hdev, skb); skb = NULL; } shdlc->nr = (shdlc->nr + 1) % 8; if (llc_shdlc_x_lt_y_lteq_z(shdlc->dnr, y_nr, shdlc->ns)) { llc_shdlc_reset_t2(shdlc, y_nr); shdlc->dnr = y_nr; } exit: kfree_skb(skb); } static void llc_shdlc_rcv_ack(struct llc_shdlc *shdlc, int y_nr) { pr_debug("remote acked up to frame %d excluded\n", y_nr); if (llc_shdlc_x_lt_y_lteq_z(shdlc->dnr, y_nr, shdlc->ns)) { llc_shdlc_reset_t2(shdlc, y_nr); shdlc->dnr = y_nr; } } static void llc_shdlc_requeue_ack_pending(struct llc_shdlc *shdlc) { struct sk_buff *skb; pr_debug("ns reset to %d\n", shdlc->dnr); while ((skb = skb_dequeue_tail(&shdlc->ack_pending_q))) { skb_pull(skb, 1); /* remove control field */ skb_queue_head(&shdlc->send_q, skb); } shdlc->ns = shdlc->dnr; } static void llc_shdlc_rcv_rej(struct llc_shdlc *shdlc, int y_nr) { struct sk_buff *skb; pr_debug("remote asks retransmission from frame %d\n", y_nr); if (llc_shdlc_x_lteq_y_lt_z(shdlc->dnr, y_nr, shdlc->ns)) { if (shdlc->t2_active) { del_timer_sync(&shdlc->t2_timer); shdlc->t2_active = false; pr_debug("Stopped T2(retransmit)\n"); } if (shdlc->dnr != y_nr) { while ((shdlc->dnr = ((shdlc->dnr + 1) % 8)) != y_nr) { skb = skb_dequeue(&shdlc->ack_pending_q); kfree_skb(skb); } } llc_shdlc_requeue_ack_pending(shdlc); } } /* See spec RR:10.8.3 REJ:10.8.4 */ static void llc_shdlc_rcv_s_frame(struct llc_shdlc *shdlc, enum sframe_type s_frame_type, int nr) { struct sk_buff *skb; if (shdlc->state != SHDLC_CONNECTED) return; switch (s_frame_type) { case S_FRAME_RR: llc_shdlc_rcv_ack(shdlc, nr); if (shdlc->rnr == true) { /* see SHDLC 10.7.7 */ shdlc->rnr = false; if (shdlc->send_q.qlen == 0) { skb = llc_shdlc_alloc_skb(shdlc, 0); if (skb) skb_queue_tail(&shdlc->send_q, skb); } } break; case S_FRAME_REJ: llc_shdlc_rcv_rej(shdlc, nr); break; case S_FRAME_RNR: llc_shdlc_rcv_ack(shdlc, nr); shdlc->rnr = true; break; default: break; } } static void llc_shdlc_connect_complete(struct llc_shdlc *shdlc, int r) { pr_debug("result=%d\n", r); del_timer_sync(&shdlc->connect_timer); if (r == 0) { shdlc->ns = 0; shdlc->nr = 0; shdlc->dnr = 0; shdlc->state = SHDLC_HALF_CONNECTED; } else { shdlc->state = SHDLC_DISCONNECTED; } shdlc->connect_result = r; wake_up(shdlc->connect_wq); } static int llc_shdlc_connect_initiate(const struct llc_shdlc *shdlc) { struct sk_buff *skb; skb = llc_shdlc_alloc_skb(shdlc, 2); if (skb == NULL) return -ENOMEM; skb_put_u8(skb, SHDLC_MAX_WINDOW); skb_put_u8(skb, SHDLC_SREJ_SUPPORT ? 1 : 0); return llc_shdlc_send_u_frame(shdlc, skb, U_FRAME_RSET); } static int llc_shdlc_connect_send_ua(const struct llc_shdlc *shdlc) { struct sk_buff *skb; skb = llc_shdlc_alloc_skb(shdlc, 0); if (skb == NULL) return -ENOMEM; return llc_shdlc_send_u_frame(shdlc, skb, U_FRAME_UA); } static void llc_shdlc_rcv_u_frame(struct llc_shdlc *shdlc, struct sk_buff *skb, enum uframe_modifier u_frame_modifier) { u8 w = SHDLC_MAX_WINDOW; bool srej_support = SHDLC_SREJ_SUPPORT; int r; pr_debug("u_frame_modifier=%d\n", u_frame_modifier); switch (u_frame_modifier) { case U_FRAME_RSET: switch (shdlc->state) { case SHDLC_NEGOTIATING: case SHDLC_CONNECTING: /* * We sent RSET, but chip wants to negotiate or we * got RSET before we managed to send out our. */ if (skb->len > 0) w = skb->data[0]; if (skb->len > 1) srej_support = skb->data[1] & 0x01 ? true : false; if ((w <= SHDLC_MAX_WINDOW) && (SHDLC_SREJ_SUPPORT || (srej_support == false))) { shdlc->w = w; shdlc->srej_support = srej_support; r = llc_shdlc_connect_send_ua(shdlc); llc_shdlc_connect_complete(shdlc, r); } break; case SHDLC_HALF_CONNECTED: /* * Chip resent RSET due to its timeout - Ignote it * as we already sent UA. */ break; case SHDLC_CONNECTED: /* * Chip wants to reset link. This is unexpected and * unsupported. */ shdlc->hard_fault = -ECONNRESET; break; default: break; } break; case U_FRAME_UA: if ((shdlc->state == SHDLC_CONNECTING && shdlc->connect_tries > 0) || (shdlc->state == SHDLC_NEGOTIATING)) { llc_shdlc_connect_complete(shdlc, 0); shdlc->state = SHDLC_CONNECTED; } break; default: break; } kfree_skb(skb); } static void llc_shdlc_handle_rcv_queue(struct llc_shdlc *shdlc) { struct sk_buff *skb; u8 control; int nr; int ns; enum sframe_type s_frame_type; enum uframe_modifier u_frame_modifier; if (shdlc->rcv_q.qlen) pr_debug("rcvQlen=%d\n", shdlc->rcv_q.qlen); while ((skb = skb_dequeue(&shdlc->rcv_q)) != NULL) { control = skb->data[0]; skb_pull(skb, 1); switch (control & SHDLC_CONTROL_HEAD_MASK) { case SHDLC_CONTROL_HEAD_I: case SHDLC_CONTROL_HEAD_I2: if (shdlc->state == SHDLC_HALF_CONNECTED) shdlc->state = SHDLC_CONNECTED; ns = (control & SHDLC_CONTROL_NS_MASK) >> 3; nr = control & SHDLC_CONTROL_NR_MASK; llc_shdlc_rcv_i_frame(shdlc, skb, ns, nr); break; case SHDLC_CONTROL_HEAD_S: if (shdlc->state == SHDLC_HALF_CONNECTED) shdlc->state = SHDLC_CONNECTED; s_frame_type = (control & SHDLC_CONTROL_TYPE_MASK) >> 3; nr = control & SHDLC_CONTROL_NR_MASK; llc_shdlc_rcv_s_frame(shdlc, s_frame_type, nr); kfree_skb(skb); break; case SHDLC_CONTROL_HEAD_U: u_frame_modifier = control & SHDLC_CONTROL_M_MASK; llc_shdlc_rcv_u_frame(shdlc, skb, u_frame_modifier); break; default: pr_err("UNKNOWN Control=%d\n", control); kfree_skb(skb); break; } } } static int llc_shdlc_w_used(int ns, int dnr) { int unack_count; if (dnr <= ns) unack_count = ns - dnr; else unack_count = 8 - dnr + ns; return unack_count; } /* Send frames according to algorithm at spec:10.8.1 */ static void llc_shdlc_handle_send_queue(struct llc_shdlc *shdlc) { struct sk_buff *skb; int r; unsigned long time_sent; if (shdlc->send_q.qlen) pr_debug("sendQlen=%d ns=%d dnr=%d rnr=%s w_room=%d unackQlen=%d\n", shdlc->send_q.qlen, shdlc->ns, shdlc->dnr, shdlc->rnr == false ? "false" : "true", shdlc->w - llc_shdlc_w_used(shdlc->ns, shdlc->dnr), shdlc->ack_pending_q.qlen); while (shdlc->send_q.qlen && shdlc->ack_pending_q.qlen < shdlc->w && (shdlc->rnr == false)) { if (shdlc->t1_active) { del_timer_sync(&shdlc->t1_timer); shdlc->t1_active = false; pr_debug("Stopped T1(send ack)\n"); } skb = skb_dequeue(&shdlc->send_q); *(u8 *)skb_push(skb, 1) = SHDLC_CONTROL_HEAD_I | (shdlc->ns << 3) | shdlc->nr; pr_debug("Sending I-Frame %d, waiting to rcv %d\n", shdlc->ns, shdlc->nr); SHDLC_DUMP_SKB("shdlc frame written", skb); r = shdlc->xmit_to_drv(shdlc->hdev, skb); if (r < 0) { shdlc->hard_fault = r; break; } shdlc->ns = (shdlc->ns + 1) % 8; time_sent = jiffies; *(unsigned long *)skb->cb = time_sent; skb_queue_tail(&shdlc->ack_pending_q, skb); if (shdlc->t2_active == false) { shdlc->t2_active = true; mod_timer(&shdlc->t2_timer, time_sent + msecs_to_jiffies(SHDLC_T2_VALUE_MS)); pr_debug("Started T2 (retransmit)\n"); } } } static void llc_shdlc_connect_timeout(struct timer_list *t) { struct llc_shdlc *shdlc = from_timer(shdlc, t, connect_timer); schedule_work(&shdlc->sm_work); } static void llc_shdlc_t1_timeout(struct timer_list *t) { struct llc_shdlc *shdlc = from_timer(shdlc, t, t1_timer); pr_debug("SoftIRQ: need to send ack\n"); schedule_work(&shdlc->sm_work); } static void llc_shdlc_t2_timeout(struct timer_list *t) { struct llc_shdlc *shdlc = from_timer(shdlc, t, t2_timer); pr_debug("SoftIRQ: need to retransmit\n"); schedule_work(&shdlc->sm_work); } static void llc_shdlc_sm_work(struct work_struct *work) { struct llc_shdlc *shdlc = container_of(work, struct llc_shdlc, sm_work); int r; mutex_lock(&shdlc->state_mutex); switch (shdlc->state) { case SHDLC_DISCONNECTED: skb_queue_purge(&shdlc->rcv_q); skb_queue_purge(&shdlc->send_q); skb_queue_purge(&shdlc->ack_pending_q); break; case SHDLC_CONNECTING: if (shdlc->hard_fault) { llc_shdlc_connect_complete(shdlc, shdlc->hard_fault); break; } if (shdlc->connect_tries++ < 5) r = llc_shdlc_connect_initiate(shdlc); else r = -ETIME; if (r < 0) { llc_shdlc_connect_complete(shdlc, r); } else { mod_timer(&shdlc->connect_timer, jiffies + msecs_to_jiffies(SHDLC_CONNECT_VALUE_MS)); shdlc->state = SHDLC_NEGOTIATING; } break; case SHDLC_NEGOTIATING: if (timer_pending(&shdlc->connect_timer) == 0) { shdlc->state = SHDLC_CONNECTING; schedule_work(&shdlc->sm_work); } llc_shdlc_handle_rcv_queue(shdlc); if (shdlc->hard_fault) { llc_shdlc_connect_complete(shdlc, shdlc->hard_fault); break; } break; case SHDLC_HALF_CONNECTED: case SHDLC_CONNECTED: llc_shdlc_handle_rcv_queue(shdlc); llc_shdlc_handle_send_queue(shdlc); if (shdlc->t1_active && timer_pending(&shdlc->t1_timer) == 0) { pr_debug("Handle T1(send ack) elapsed (T1 now inactive)\n"); shdlc->t1_active = false; r = llc_shdlc_send_s_frame(shdlc, S_FRAME_RR, shdlc->nr); if (r < 0) shdlc->hard_fault = r; } if (shdlc->t2_active && timer_pending(&shdlc->t2_timer) == 0) { pr_debug("Handle T2(retransmit) elapsed (T2 inactive)\n"); shdlc->t2_active = false; llc_shdlc_requeue_ack_pending(shdlc); llc_shdlc_handle_send_queue(shdlc); } if (shdlc->hard_fault) shdlc->llc_failure(shdlc->hdev, shdlc->hard_fault); break; default: break; } mutex_unlock(&shdlc->state_mutex); } /* * Called from syscall context to establish shdlc link. Sleeps until * link is ready or failure. */ static int llc_shdlc_connect(struct llc_shdlc *shdlc) { DECLARE_WAIT_QUEUE_HEAD_ONSTACK(connect_wq); mutex_lock(&shdlc->state_mutex); shdlc->state = SHDLC_CONNECTING; shdlc->connect_wq = &connect_wq; shdlc->connect_tries = 0; shdlc->connect_result = 1; mutex_unlock(&shdlc->state_mutex); schedule_work(&shdlc->sm_work); wait_event(connect_wq, shdlc->connect_result != 1); return shdlc->connect_result; } static void llc_shdlc_disconnect(struct llc_shdlc *shdlc) { mutex_lock(&shdlc->state_mutex); shdlc->state = SHDLC_DISCONNECTED; mutex_unlock(&shdlc->state_mutex); schedule_work(&shdlc->sm_work); } /* * Receive an incoming shdlc frame. Frame has already been crc-validated. * skb contains only LLC header and payload. * If skb == NULL, it is a notification that the link below is dead. */ static void llc_shdlc_recv_frame(struct llc_shdlc *shdlc, struct sk_buff *skb) { if (skb == NULL) { pr_err("NULL Frame -> link is dead\n"); shdlc->hard_fault = -EREMOTEIO; } else { SHDLC_DUMP_SKB("incoming frame", skb); skb_queue_tail(&shdlc->rcv_q, skb); } schedule_work(&shdlc->sm_work); } static void *llc_shdlc_init(struct nfc_hci_dev *hdev, xmit_to_drv_t xmit_to_drv, rcv_to_hci_t rcv_to_hci, int tx_headroom, int tx_tailroom, int *rx_headroom, int *rx_tailroom, llc_failure_t llc_failure) { struct llc_shdlc *shdlc; *rx_headroom = SHDLC_LLC_HEAD_ROOM; *rx_tailroom = 0; shdlc = kzalloc(sizeof(struct llc_shdlc), GFP_KERNEL); if (shdlc == NULL) return NULL; mutex_init(&shdlc->state_mutex); shdlc->state = SHDLC_DISCONNECTED; timer_setup(&shdlc->connect_timer, llc_shdlc_connect_timeout, 0); timer_setup(&shdlc->t1_timer, llc_shdlc_t1_timeout, 0); timer_setup(&shdlc->t2_timer, llc_shdlc_t2_timeout, 0); shdlc->w = SHDLC_MAX_WINDOW; shdlc->srej_support = SHDLC_SREJ_SUPPORT; skb_queue_head_init(&shdlc->rcv_q); skb_queue_head_init(&shdlc->send_q); skb_queue_head_init(&shdlc->ack_pending_q); INIT_WORK(&shdlc->sm_work, llc_shdlc_sm_work); shdlc->hdev = hdev; shdlc->xmit_to_drv = xmit_to_drv; shdlc->rcv_to_hci = rcv_to_hci; shdlc->tx_headroom = tx_headroom; shdlc->tx_tailroom = tx_tailroom; shdlc->llc_failure = llc_failure; return shdlc; } static void llc_shdlc_deinit(struct nfc_llc *llc) { struct llc_shdlc *shdlc = nfc_llc_get_data(llc); skb_queue_purge(&shdlc->rcv_q); skb_queue_purge(&shdlc->send_q); skb_queue_purge(&shdlc->ack_pending_q); kfree(shdlc); } static int llc_shdlc_start(struct nfc_llc *llc) { struct llc_shdlc *shdlc = nfc_llc_get_data(llc); return llc_shdlc_connect(shdlc); } static int llc_shdlc_stop(struct nfc_llc *llc) { struct llc_shdlc *shdlc = nfc_llc_get_data(llc); llc_shdlc_disconnect(shdlc); return 0; } static void llc_shdlc_rcv_from_drv(struct nfc_llc *llc, struct sk_buff *skb) { struct llc_shdlc *shdlc = nfc_llc_get_data(llc); llc_shdlc_recv_frame(shdlc, skb); } static int llc_shdlc_xmit_from_hci(struct nfc_llc *llc, struct sk_buff *skb) { struct llc_shdlc *shdlc = nfc_llc_get_data(llc); skb_queue_tail(&shdlc->send_q, skb); schedule_work(&shdlc->sm_work); return 0; } static const struct nfc_llc_ops llc_shdlc_ops = { .init = llc_shdlc_init, .deinit = llc_shdlc_deinit, .start = llc_shdlc_start, .stop = llc_shdlc_stop, .rcv_from_drv = llc_shdlc_rcv_from_drv, .xmit_from_hci = llc_shdlc_xmit_from_hci, }; int nfc_llc_shdlc_register(void) { return nfc_llc_register(LLC_SHDLC_NAME, &llc_shdlc_ops); } |