net/nfc/llcp/llcp.c

   1 /*
   2  * Copyright (C) 2011  Intel Corporation. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the
  16  * Free Software Foundation, Inc.,
  17  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18  */
  19
  20 #define pr_fmt(fmt) "llcp: %s: " fmt, __func__
  21
  22 #include <linux/init.h>
  23 #include <linux/kernel.h>
  24 #include <linux/list.h>
  25 #include <linux/nfc.h>
  26
  27 #include "../nfc.h"
  28 #include "llcp.h"
  29
  30 static u8 llcp_magic[3] = {0x46, 0x66, 0x6d};
  31
  32 static struct list_head llcp_devices;
  33
  34 void nfc_llcp_sock_link(struct llcp_sock_list *l, struct sock *sk)
  35 {
  36         write_lock(&l->lock);
  37         sk_add_node(sk, &l->head);
  38         write_unlock(&l->lock);
  39 }
  40
  41 void nfc_llcp_sock_unlink(struct llcp_sock_list *l, struct sock *sk)
  42 {
  43         write_lock(&l->lock);
  44         sk_del_node_init(sk);
  45         write_unlock(&l->lock);
  46 }
  47
  48 static void nfc_llcp_socket_release(struct nfc_llcp_local *local, bool listen)
  49 {
  50         struct sock *sk;
  51         struct hlist_node *node, *tmp;
  52         struct nfc_llcp_sock *llcp_sock;
  53
  54         write_lock(&local->sockets.lock);
  55
  56         sk_for_each_safe(sk, node, tmp, &local->sockets.head) {
  57                 llcp_sock = nfc_llcp_sock(sk);
  58
  59                 bh_lock_sock(sk);
  60
  61                 if (sk->sk_state == LLCP_CONNECTED)
  62                         nfc_put_device(llcp_sock->dev);
  63
  64                 if (sk->sk_state == LLCP_LISTEN) {
  65                         struct nfc_llcp_sock *lsk, *n;
  66                         struct sock *accept_sk;
  67
  68                         list_for_each_entry_safe(lsk, n, &llcp_sock->accept_queue,
  69                                                  accept_queue) {
  70                                 accept_sk = &lsk->sk;
  71                                 bh_lock_sock(accept_sk);
  72
  73                                 nfc_llcp_accept_unlink(accept_sk);
  74
  75                                 accept_sk->sk_state = LLCP_CLOSED;
  76
  77                                 bh_unlock_sock(accept_sk);
  78
  79                                 sock_orphan(accept_sk);
  80                         }
  81
  82                         if (listen == true) {
  83                                 bh_unlock_sock(sk);
  84                                 continue;
  85                         }
  86                 }
  87
  88                 sk->sk_state = LLCP_CLOSED;
  89
  90                 bh_unlock_sock(sk);
  91
  92                 sock_orphan(sk);
  93
  94                 sk_del_node_init(sk);
  95         }
  96
  97         write_unlock(&local->sockets.lock);
  98 }
  99
 100 struct nfc_llcp_local *nfc_llcp_local_get(struct nfc_llcp_local *local)
 101 {
 102         kref_get(&local->ref);
 103
 104         return local;
 105 }
 106
 107 static void local_release(struct kref *ref)
 108 {
 109         struct nfc_llcp_local *local;
 110
 111         local = container_of(ref, struct nfc_llcp_local, ref);
 112
 113         list_del(&local->list);
 114         nfc_llcp_socket_release(local, false);
 115         del_timer_sync(&local->link_timer);
 116         skb_queue_purge(&local->tx_queue);
 117         cancel_work_sync(&local->tx_work);
 118         cancel_work_sync(&local->rx_work);
 119         cancel_work_sync(&local->timeout_work);
 120         kfree_skb(local->rx_pending);
 121         kfree(local);
 122 }
 123
 124 int nfc_llcp_local_put(struct nfc_llcp_local *local)
 125 {
 126         if (local == NULL)
 127                 return 0;
 128
 129         return kref_put(&local->ref, local_release);
 130 }
 131
 132 static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local,
 133                                                u8 ssap, u8 dsap)
 134 {
 135         struct sock *sk;
 136         struct hlist_node *node;
 137         struct nfc_llcp_sock *llcp_sock;
 138
 139         pr_debug("ssap dsap %d %d\n", ssap, dsap);
 140
 141         if (ssap == 0 && dsap == 0)
 142                 return NULL;
 143
 144         read_lock(&local->sockets.lock);
 145
 146         llcp_sock = NULL;
 147
 148         sk_for_each(sk, node, &local->sockets.head) {
 149                 llcp_sock = nfc_llcp_sock(sk);
 150
 151                 if (llcp_sock->ssap == ssap && llcp_sock->dsap == dsap)
 152                         break;
 153         }
 154
 155         read_unlock(&local->sockets.lock);
 156
 157         if (llcp_sock == NULL)
 158                 return NULL;
 159
 160         sock_hold(&llcp_sock->sk);
 161
 162         return llcp_sock;
 163 }
 164
 165 static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock)
 166 {
 167         sock_put(&sock->sk);
 168 }
 169
 170 static void nfc_llcp_timeout_work(struct work_struct *work)
 171 {
 172         struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
 173                                                     timeout_work);
 174
 175         nfc_dep_link_down(local->dev);
 176 }
 177
 178 static void nfc_llcp_symm_timer(unsigned long data)
 179 {
 180         struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
 181
 182         pr_err("SYMM timeout\n");
 183
 184         queue_work(system_nrt_wq, &local->timeout_work);
 185 }
 186
 187 struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev)
 188 {
 189         struct nfc_llcp_local *local, *n;
 190
 191         list_for_each_entry_safe(local, n, &llcp_devices, list)
 192                 if (local->dev == dev)
 193                         return local;
 194
 195         pr_debug("No device found\n");
 196
 197         return NULL;
 198 }
 199
 200 static char *wks[] = {
 201         NULL,
 202         NULL, /* SDP */
 203         "urn:nfc:sn:ip",
 204         "urn:nfc:sn:obex",
 205         "urn:nfc:sn:snep",
 206 };
 207
 208 static int nfc_llcp_wks_sap(char *service_name, size_t service_name_len)
 209 {
 210         int sap, num_wks;
 211
 212         pr_debug("%s\n", service_name);
 213
 214         if (service_name == NULL)
 215                 return -EINVAL;
 216
 217         num_wks = ARRAY_SIZE(wks);
 218
 219         for (sap = 0; sap < num_wks; sap++) {
 220                 if (wks[sap] == NULL)
 221                         continue;
 222
 223                 if (strncmp(wks[sap], service_name, service_name_len) == 0)
 224                         return sap;
 225         }
 226
 227         return -EINVAL;
 228 }
 229
 230 static
 231 struct nfc_llcp_sock *nfc_llcp_sock_from_sn(struct nfc_llcp_local *local,
 232                                             u8 *sn, size_t sn_len)
 233 {
 234         struct sock *sk;
 235         struct hlist_node *node;
 236         struct nfc_llcp_sock *llcp_sock, *tmp_sock;
 237
 238         pr_debug("sn %zd %p\n", sn_len, sn);
 239
 240         if (sn == NULL || sn_len == 0)
 241                 return NULL;
 242
 243         read_lock(&local->sockets.lock);
 244
 245         llcp_sock = NULL;
 246
 247         sk_for_each(sk, node, &local->sockets.head) {
 248                 tmp_sock = nfc_llcp_sock(sk);
 249
 250                 pr_debug("llcp sock %p\n", tmp_sock);
 251
 252                 if (tmp_sock->sk.sk_state != LLCP_LISTEN)
 253                         continue;
 254
 255                 if (tmp_sock->service_name == NULL ||
 256                     tmp_sock->service_name_len == 0)
 257                         continue;
 258
 259                 if (tmp_sock->service_name_len != sn_len)
 260                         continue;
 261
 262                 if (memcmp(sn, tmp_sock->service_name, sn_len) == 0) {
 263                         llcp_sock = tmp_sock;
 264                         break;
 265                 }
 266         }
 267
 268         read_unlock(&local->sockets.lock);
 269
 270         pr_debug("Found llcp sock %p\n", llcp_sock);
 271
 272         return llcp_sock;
 273 }
 274
 275 u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,
 276                          struct nfc_llcp_sock *sock)
 277 {
 278         mutex_lock(&local->sdp_lock);
 279
 280         if (sock->service_name != NULL && sock->service_name_len > 0) {
 281                 int ssap = nfc_llcp_wks_sap(sock->service_name,
 282                                             sock->service_name_len);
 283
 284                 if (ssap > 0) {
 285                         pr_debug("WKS %d\n", ssap);
 286
 287                         /* This is a WKS, let's check if it's free */
 288                         if (local->local_wks & BIT(ssap)) {
 289                                 mutex_unlock(&local->sdp_lock);
 290
 291                                 return LLCP_SAP_MAX;
 292                         }
 293
 294                         set_bit(ssap, &local->local_wks);
 295                         mutex_unlock(&local->sdp_lock);
 296
 297                         return ssap;
 298                 }
 299
 300                 /*
 301                  * Check if there already is a non WKS socket bound
 302                  * to this service name.
 303                  */
 304                 if (nfc_llcp_sock_from_sn(local, sock->service_name,
 305                                           sock->service_name_len) != NULL) {
 306                         mutex_unlock(&local->sdp_lock);
 307
 308                         return LLCP_SAP_MAX;
 309                 }
 310
 311                 mutex_unlock(&local->sdp_lock);
 312
 313                 return LLCP_SDP_UNBOUND;
 314
 315         } else if (sock->ssap != 0 && sock->ssap < LLCP_WKS_NUM_SAP) {
 316                 if (!test_bit(sock->ssap, &local->local_wks)) {
 317                         set_bit(sock->ssap, &local->local_wks);
 318                         mutex_unlock(&local->sdp_lock);
 319
 320                         return sock->ssap;
 321                 }
 322         }
 323
 324         mutex_unlock(&local->sdp_lock);
 325
 326         return LLCP_SAP_MAX;
 327 }
 328
 329 u8 nfc_llcp_get_local_ssap(struct nfc_llcp_local *local)
 330 {
 331         u8 local_ssap;
 332
 333         mutex_lock(&local->sdp_lock);
 334
 335         local_ssap = find_first_zero_bit(&local->local_sap, LLCP_LOCAL_NUM_SAP);
 336         if (local_ssap == LLCP_LOCAL_NUM_SAP) {
 337                 mutex_unlock(&local->sdp_lock);
 338                 return LLCP_SAP_MAX;
 339         }
 340
 341         set_bit(local_ssap, &local->local_sap);
 342
 343         mutex_unlock(&local->sdp_lock);
 344
 345         return local_ssap + LLCP_LOCAL_SAP_OFFSET;
 346 }
 347
 348 void nfc_llcp_put_ssap(struct nfc_llcp_local *local, u8 ssap)
 349 {
 350         u8 local_ssap;
 351         unsigned long *sdp;
 352
 353         if (ssap < LLCP_WKS_NUM_SAP) {
 354                 local_ssap = ssap;
 355                 sdp = &local->local_wks;
 356         } else if (ssap < LLCP_LOCAL_NUM_SAP) {
 357                 atomic_t *client_cnt;
 358
 359                 local_ssap = ssap - LLCP_WKS_NUM_SAP;
 360                 sdp = &local->local_sdp;
 361                 client_cnt = &local->local_sdp_cnt[local_ssap];
 362
 363                 pr_debug("%d clients\n", atomic_read(client_cnt));
 364
 365                 mutex_lock(&local->sdp_lock);
 366
 367                 if (atomic_dec_and_test(client_cnt)) {
 368                         struct nfc_llcp_sock *l_sock;
 369
 370                         pr_debug("No more clients for SAP %d\n", ssap);
 371
 372                         clear_bit(local_ssap, sdp);
 373
 374                         /* Find the listening sock and set it back to UNBOUND */
 375                         l_sock = nfc_llcp_sock_get(local, ssap, LLCP_SAP_SDP);
 376                         if (l_sock) {
 377                                 l_sock->ssap = LLCP_SDP_UNBOUND;
 378                                 nfc_llcp_sock_put(l_sock);
 379                         }
 380                 }
 381
 382                 mutex_unlock(&local->sdp_lock);
 383
 384                 return;
 385         } else if (ssap < LLCP_MAX_SAP) {
 386                 local_ssap = ssap - LLCP_LOCAL_NUM_SAP;
 387                 sdp = &local->local_sap;
 388         } else {
 389                 return;
 390         }
 391
 392         mutex_lock(&local->sdp_lock);
 393
 394         clear_bit(local_ssap, sdp);
 395
 396         mutex_unlock(&local->sdp_lock);
 397 }
 398
 399 static u8 nfc_llcp_reserve_sdp_ssap(struct nfc_llcp_local *local)
 400 {
 401         u8 ssap;
 402
 403         mutex_lock(&local->sdp_lock);
 404
 405         ssap = find_first_zero_bit(&local->local_sdp, LLCP_SDP_NUM_SAP);
 406         if (ssap == LLCP_SDP_NUM_SAP) {
 407                 mutex_unlock(&local->sdp_lock);
 408
 409                 return LLCP_SAP_MAX;
 410         }
 411
 412         pr_debug("SDP ssap %d\n", LLCP_WKS_NUM_SAP + ssap);
 413
 414         set_bit(ssap, &local->local_sdp);
 415
 416         mutex_unlock(&local->sdp_lock);
 417
 418         return LLCP_WKS_NUM_SAP + ssap;
 419 }
 420
 421 static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
 422 {
 423         u8 *gb_cur, *version_tlv, version, version_length;
 424         u8 *lto_tlv, lto, lto_length;
 425         u8 *wks_tlv, wks_length;
 426         u8 *miux_tlv, miux_length;
 427         __be16 miux;
 428         u8 gb_len = 0;
 429         int ret = 0;
 430
 431         version = LLCP_VERSION_11;
 432         version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version,
 433                                          1, &version_length);
 434         gb_len += version_length;
 435
 436         /* 1500 ms */
 437         lto = 150;
 438         lto_tlv = nfc_llcp_build_tlv(LLCP_TLV_LTO, &lto, 1, &lto_length);
 439         gb_len += lto_length;
 440
 441         pr_debug("Local wks 0x%lx\n", local->local_wks);
 442         wks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 *)&local->local_wks, 2,
 443                                      &wks_length);
 444         gb_len += wks_length;
 445
 446         miux = cpu_to_be16(LLCP_MAX_MIUX);
 447         miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
 448                                       &miux_length);
 449         gb_len += miux_length;
 450
 451         gb_len += ARRAY_SIZE(llcp_magic);
 452
 453         if (gb_len > NFC_MAX_GT_LEN) {
 454                 ret = -EINVAL;
 455                 goto out;
 456         }
 457
 458         gb_cur = local->gb;
 459
 460         memcpy(gb_cur, llcp_magic, ARRAY_SIZE(llcp_magic));
 461         gb_cur += ARRAY_SIZE(llcp_magic);
 462
 463         memcpy(gb_cur, version_tlv, version_length);
 464         gb_cur += version_length;
 465
 466         memcpy(gb_cur, lto_tlv, lto_length);
 467         gb_cur += lto_length;
 468
 469         memcpy(gb_cur, wks_tlv, wks_length);
 470         gb_cur += wks_length;
 471
 472         memcpy(gb_cur, miux_tlv, miux_length);
 473         gb_cur += miux_length;
 474
 475         local->gb_len = gb_len;
 476
 477 out:
 478         kfree(version_tlv);
 479         kfree(lto_tlv);
 480         kfree(wks_tlv);
 481         kfree(miux_tlv);
 482
 483         return ret;
 484 }
 485
 486 u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len)
 487 {
 488         struct nfc_llcp_local *local;
 489
 490         local = nfc_llcp_find_local(dev);
 491         if (local == NULL) {
 492                 *general_bytes_len = 0;
 493                 return NULL;
 494         }
 495
 496         nfc_llcp_build_gb(local);
 497
 498         *general_bytes_len = local->gb_len;
 499
 500         return local->gb;
 501 }
 502
 503 int nfc_llcp_set_remote_gb(struct nfc_dev *dev, u8 *gb, u8 gb_len)
 504 {
 505         struct nfc_llcp_local *local = nfc_llcp_find_local(dev);
 506
 507         if (local == NULL) {
 508                 pr_err("No LLCP device\n");
 509                 return -ENODEV;
 510         }
 511
 512         memset(local->remote_gb, 0, NFC_MAX_GT_LEN);
 513         memcpy(local->remote_gb, gb, gb_len);
 514         local->remote_gb_len = gb_len;
 515
 516         if (local->remote_gb == NULL || local->remote_gb_len == 0)
 517                 return -ENODEV;
 518
 519         if (memcmp(local->remote_gb, llcp_magic, 3)) {
 520                 pr_err("MAC does not support LLCP\n");
 521                 return -EINVAL;
 522         }
 523
 524         return nfc_llcp_parse_gb_tlv(local,
 525                                      &local->remote_gb[3],
 526                                      local->remote_gb_len - 3);
 527 }
 528
 529 static u8 nfc_llcp_dsap(struct sk_buff *pdu)
 530 {
 531         return (pdu->data[0] & 0xfc) >> 2;
 532 }
 533
 534 static u8 nfc_llcp_ptype(struct sk_buff *pdu)
 535 {
 536         return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6);
 537 }
 538
 539 static u8 nfc_llcp_ssap(struct sk_buff *pdu)
 540 {
 541         return pdu->data[1] & 0x3f;
 542 }
 543
 544 static u8 nfc_llcp_ns(struct sk_buff *pdu)
 545 {
 546         return pdu->data[2] >> 4;
 547 }
 548
 549 static u8 nfc_llcp_nr(struct sk_buff *pdu)
 550 {
 551         return pdu->data[2] & 0xf;
 552 }
 553
 554 static void nfc_llcp_set_nrns(struct nfc_llcp_sock *sock, struct sk_buff *pdu)
 555 {
 556         pdu->data[2] = (sock->send_n << 4) | (sock->recv_n);
 557         sock->send_n = (sock->send_n + 1) % 16;
 558         sock->recv_ack_n = (sock->recv_n - 1) % 16;
 559 }
 560
 561 void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local *local,
 562                                struct sk_buff *skb, u8 direction)
 563 {
 564         struct hlist_node *node;
 565         struct sk_buff *skb_copy = NULL, *nskb;
 566         struct sock *sk;
 567         u8 *data;
 568
 569         read_lock(&local->raw_sockets.lock);
 570
 571         sk_for_each(sk, node, &local->raw_sockets.head) {
 572                 if (sk->sk_state != LLCP_BOUND)
 573                         continue;
 574
 575                 if (skb_copy == NULL) {
 576                         skb_copy = __pskb_copy(skb, NFC_LLCP_RAW_HEADER_SIZE,
 577                                                GFP_ATOMIC);
 578
 579                         if (skb_copy == NULL)
 580                                 continue;
 581
 582                         data = skb_push(skb_copy, NFC_LLCP_RAW_HEADER_SIZE);
 583
 584                         data[0] = local->dev ? local->dev->idx : 0xFF;
 585                         data[1] = direction;
 586                 }
 587
 588                 nskb = skb_clone(skb_copy, GFP_ATOMIC);
 589                 if (!nskb)
 590                         continue;
 591
 592                 if (sock_queue_rcv_skb(sk, nskb))
 593                         kfree_skb(nskb);
 594         }
 595
 596         read_unlock(&local->raw_sockets.lock);
 597
 598         kfree_skb(skb_copy);
 599 }
 600
 601 static void nfc_llcp_tx_work(struct work_struct *work)
 602 {
 603         struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
 604                                                     tx_work);
 605         struct sk_buff *skb;
 606         struct sock *sk;
 607         struct nfc_llcp_sock *llcp_sock;
 608
 609         skb = skb_dequeue(&local->tx_queue);
 610         if (skb != NULL) {
 611                 sk = skb->sk;
 612                 llcp_sock = nfc_llcp_sock(sk);
 613                 if (llcp_sock != NULL) {
 614                         int ret;
 615
 616                         pr_debug("Sending pending skb\n");
 617                         print_hex_dump(KERN_DEBUG, "LLCP Tx: ",
 618                                        DUMP_PREFIX_OFFSET, 16, 1,
 619                                        skb->data, skb->len, true);
 620
 621                         nfc_llcp_send_to_raw_sock(local, skb,
 622                                                   NFC_LLCP_DIRECTION_TX);
 623
 624                         ret = nfc_data_exchange(local->dev, local->target_idx,
 625                                                 skb, nfc_llcp_recv, local);
 626
 627                         if (!ret && nfc_llcp_ptype(skb) == LLCP_PDU_I) {
 628                                 skb = skb_get(skb);
 629                                 skb_queue_tail(&llcp_sock->tx_pending_queue,
 630                                                skb);
 631                         }
 632                 } else {
 633                         nfc_llcp_send_symm(local->dev);
 634                 }
 635         } else {
 636                 nfc_llcp_send_symm(local->dev);
 637         }
 638
 639         mod_timer(&local->link_timer,
 640                   jiffies + msecs_to_jiffies(2 * local->remote_lto));
 641 }
 642
 643 static struct nfc_llcp_sock *nfc_llcp_connecting_sock_get(struct nfc_llcp_local *local,
 644                                                           u8 ssap)
 645 {
 646         struct sock *sk;
 647         struct nfc_llcp_sock *llcp_sock;
 648         struct hlist_node *node;
 649
 650         read_lock(&local->connecting_sockets.lock);
 651
 652         sk_for_each(sk, node, &local->connecting_sockets.head) {
 653                 llcp_sock = nfc_llcp_sock(sk);
 654
 655                 if (llcp_sock->ssap == ssap) {
 656                         sock_hold(&llcp_sock->sk);
 657                         goto out;
 658                 }
 659         }
 660
 661         llcp_sock = NULL;
 662
 663 out:
 664         read_unlock(&local->connecting_sockets.lock);
 665
 666         return llcp_sock;
 667 }
 668
 669 static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local,
 670                                                   u8 *sn, size_t sn_len)
 671 {
 672         struct nfc_llcp_sock *llcp_sock;
 673
 674         llcp_sock = nfc_llcp_sock_from_sn(local, sn, sn_len);
 675
 676         if (llcp_sock == NULL)
 677                 return NULL;
 678
 679         sock_hold(&llcp_sock->sk);
 680
 681         return llcp_sock;
 682 }
 683
 684 static u8 *nfc_llcp_connect_sn(struct sk_buff *skb, size_t *sn_len)
 685 {
 686         u8 *tlv = &skb->data[2], type, length;
 687         size_t tlv_array_len = skb->len - LLCP_HEADER_SIZE, offset = 0;
 688
 689         while (offset < tlv_array_len) {
 690                 type = tlv[0];
 691                 length = tlv[1];
 692
 693                 pr_debug("type 0x%x length %d\n", type, length);
 694
 695                 if (type == LLCP_TLV_SN) {
 696                         *sn_len = length;
 697                         return &tlv[2];
 698                 }
 699
 700                 offset += length + 2;
 701                 tlv += length + 2;
 702         }
 703
 704         return NULL;
 705 }
 706
 707 static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
 708                                   struct sk_buff *skb)
 709 {
 710         struct sock *new_sk, *parent;
 711         struct nfc_llcp_sock *sock, *new_sock;
 712         u8 dsap, ssap, reason;
 713
 714         dsap = nfc_llcp_dsap(skb);
 715         ssap = nfc_llcp_ssap(skb);
 716
 717         pr_debug("%d %d\n", dsap, ssap);
 718
 719         if (dsap != LLCP_SAP_SDP) {
 720                 sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
 721                 if (sock == NULL || sock->sk.sk_state != LLCP_LISTEN) {
 722                         reason = LLCP_DM_NOBOUND;
 723                         goto fail;
 724                 }
 725         } else {
 726                 u8 *sn;
 727                 size_t sn_len;
 728
 729                 sn = nfc_llcp_connect_sn(skb, &sn_len);
 730                 if (sn == NULL) {
 731                         reason = LLCP_DM_NOBOUND;
 732                         goto fail;
 733                 }
 734
 735                 pr_debug("Service name length %zu\n", sn_len);
 736
 737                 sock = nfc_llcp_sock_get_sn(local, sn, sn_len);
 738                 if (sock == NULL) {
 739                         reason = LLCP_DM_NOBOUND;
 740                         goto fail;
 741                 }
 742         }
 743
 744         lock_sock(&sock->sk);
 745
 746         parent = &sock->sk;
 747
 748         if (sk_acceptq_is_full(parent)) {
 749                 reason = LLCP_DM_REJ;
 750                 release_sock(&sock->sk);
 751                 sock_put(&sock->sk);
 752                 goto fail;
 753         }
 754
 755         if (sock->ssap == LLCP_SDP_UNBOUND) {
 756                 u8 ssap = nfc_llcp_reserve_sdp_ssap(local);
 757
 758                 pr_debug("First client, reserving %d\n", ssap);
 759
 760                 if (ssap == LLCP_SAP_MAX) {
 761                         reason = LLCP_DM_REJ;
 762                         release_sock(&sock->sk);
 763                         sock_put(&sock->sk);
 764                         goto fail;
 765                 }
 766
 767                 sock->ssap = ssap;
 768         }
 769
 770         new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC);
 771         if (new_sk == NULL) {
 772                 reason = LLCP_DM_REJ;
 773                 release_sock(&sock->sk);
 774                 sock_put(&sock->sk);
 775                 goto fail;
 776         }
 777
 778         new_sock = nfc_llcp_sock(new_sk);
 779         new_sock->dev = local->dev;
 780         new_sock->local = nfc_llcp_local_get(local);
 781         new_sock->miu = local->remote_miu;
 782         new_sock->nfc_protocol = sock->nfc_protocol;
 783         new_sock->dsap = ssap;
 784         new_sock->target_idx = local->target_idx;
 785         new_sock->parent = parent;
 786         new_sock->ssap = sock->ssap;
 787         if (sock->ssap < LLCP_LOCAL_NUM_SAP && sock->ssap >= LLCP_WKS_NUM_SAP) {
 788                 atomic_t *client_count;
 789
 790                 pr_debug("reserved_ssap %d for %p\n", sock->ssap, new_sock);
 791
 792                 client_count =
 793                         &local->local_sdp_cnt[sock->ssap - LLCP_WKS_NUM_SAP];
 794
 795                 atomic_inc(client_count);
 796                 new_sock->reserved_ssap = sock->ssap;
 797         }
 798
 799         nfc_llcp_parse_connection_tlv(new_sock, &skb->data[LLCP_HEADER_SIZE],
 800                                       skb->len - LLCP_HEADER_SIZE);
 801
 802         pr_debug("new sock %p sk %p\n", new_sock, &new_sock->sk);
 803
 804         nfc_llcp_sock_link(&local->sockets, new_sk);
 805
 806         nfc_llcp_accept_enqueue(&sock->sk, new_sk);
 807
 808         nfc_get_device(local->dev->idx);
 809
 810         new_sk->sk_state = LLCP_CONNECTED;
 811
 812         /* Wake the listening processes */
 813         parent->sk_data_ready(parent, 0);
 814
 815         /* Send CC */
 816         nfc_llcp_send_cc(new_sock);
 817
 818         release_sock(&sock->sk);
 819         sock_put(&sock->sk);
 820
 821         return;
 822
 823 fail:
 824         /* Send DM */
 825         nfc_llcp_send_dm(local, dsap, ssap, reason);
 826
 827         return;
 828
 829 }
 830
 831 int nfc_llcp_queue_i_frames(struct nfc_llcp_sock *sock)
 832 {
 833         int nr_frames = 0;
 834         struct nfc_llcp_local *local = sock->local;
 835
 836         pr_debug("Remote ready %d tx queue len %d remote rw %d",
 837                  sock->remote_ready, skb_queue_len(&sock->tx_pending_queue),
 838                  sock->rw);
 839
 840         /* Try to queue some I frames for transmission */
 841         while (sock->remote_ready &&
 842                skb_queue_len(&sock->tx_pending_queue) < sock->rw) {
 843                 struct sk_buff *pdu;
 844
 845                 pdu = skb_dequeue(&sock->tx_queue);
 846                 if (pdu == NULL)
 847                         break;
 848
 849                 /* Update N(S)/N(R) */
 850                 nfc_llcp_set_nrns(sock, pdu);
 851
 852                 skb_queue_tail(&local->tx_queue, pdu);
 853                 nr_frames++;
 854         }
 855
 856         return nr_frames;
 857 }
 858
 859 static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local,
 860                                struct sk_buff *skb)
 861 {
 862         struct nfc_llcp_sock *llcp_sock;
 863         struct sock *sk;
 864         u8 dsap, ssap, ptype, ns, nr;
 865
 866         ptype = nfc_llcp_ptype(skb);
 867         dsap = nfc_llcp_dsap(skb);
 868         ssap = nfc_llcp_ssap(skb);
 869         ns = nfc_llcp_ns(skb);
 870         nr = nfc_llcp_nr(skb);
 871
 872         pr_debug("%d %d R %d S %d\n", dsap, ssap, nr, ns);
 873
 874         llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
 875         if (llcp_sock == NULL) {
 876                 nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
 877                 return;
 878         }
 879
 880         sk = &llcp_sock->sk;
 881         lock_sock(sk);
 882         if (sk->sk_state == LLCP_CLOSED) {
 883                 release_sock(sk);
 884                 nfc_llcp_sock_put(llcp_sock);
 885         }
 886
 887         /* Pass the payload upstream */
 888         if (ptype == LLCP_PDU_I) {
 889                 pr_debug("I frame, queueing on %p\n", &llcp_sock->sk);
 890
 891                 if (ns == llcp_sock->recv_n)
 892                         llcp_sock->recv_n = (llcp_sock->recv_n + 1) % 16;
 893                 else
 894                         pr_err("Received out of sequence I PDU\n");
 895
 896                 skb_pull(skb, LLCP_HEADER_SIZE + LLCP_SEQUENCE_SIZE);
 897                 if (sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
 898                         pr_err("receive queue is full\n");
 899                         skb_queue_head(&llcp_sock->tx_backlog_queue, skb);
 900                 }
 901         }
 902
 903         /* Remove skbs from the pending queue */
 904         if (llcp_sock->send_ack_n != nr) {
 905                 struct sk_buff *s, *tmp;
 906
 907                 llcp_sock->send_ack_n = nr;
 908
 909                 /* Remove and free all skbs until ns == nr */
 910                 skb_queue_walk_safe(&llcp_sock->tx_pending_queue, s, tmp) {
 911                         skb_unlink(s, &llcp_sock->tx_pending_queue);
 912                         kfree_skb(s);
 913
 914                         if (nfc_llcp_ns(s) == nr)
 915                                 break;
 916                 }
 917
 918                 /* Re-queue the remaining skbs for transmission */
 919                 skb_queue_reverse_walk_safe(&llcp_sock->tx_pending_queue,
 920                                             s, tmp) {
 921                         skb_unlink(s, &llcp_sock->tx_pending_queue);
 922                         skb_queue_head(&local->tx_queue, s);
 923                 }
 924         }
 925
 926         if (ptype == LLCP_PDU_RR)
 927                 llcp_sock->remote_ready = true;
 928         else if (ptype == LLCP_PDU_RNR)
 929                 llcp_sock->remote_ready = false;
 930
 931         if (nfc_llcp_queue_i_frames(llcp_sock) == 0 && ptype == LLCP_PDU_I)
 932                 nfc_llcp_send_rr(llcp_sock);
 933
 934         release_sock(sk);
 935         nfc_llcp_sock_put(llcp_sock);
 936 }
 937
 938 static void nfc_llcp_recv_disc(struct nfc_llcp_local *local,
 939                                struct sk_buff *skb)
 940 {
 941         struct nfc_llcp_sock *llcp_sock;
 942         struct sock *sk;
 943         u8 dsap, ssap;
 944
 945         dsap = nfc_llcp_dsap(skb);
 946         ssap = nfc_llcp_ssap(skb);
 947
 948         llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
 949         if (llcp_sock == NULL) {
 950                 nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
 951                 return;
 952         }
 953
 954         sk = &llcp_sock->sk;
 955         lock_sock(sk);
 956         if (sk->sk_state == LLCP_CLOSED) {
 957                 release_sock(sk);
 958                 nfc_llcp_sock_put(llcp_sock);
 959         }
 960
 961         if (sk->sk_state == LLCP_CONNECTED) {
 962                 nfc_put_device(local->dev);
 963                 sk->sk_state = LLCP_CLOSED;
 964                 sk->sk_state_change(sk);
 965         }
 966
 967         nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_DISC);
 968
 969         release_sock(sk);
 970         nfc_llcp_sock_put(llcp_sock);
 971 }
 972
 973 static void nfc_llcp_recv_cc(struct nfc_llcp_local *local, struct sk_buff *skb)
 974 {
 975         struct nfc_llcp_sock *llcp_sock;
 976         struct sock *sk;
 977         u8 dsap, ssap;
 978
 979         dsap = nfc_llcp_dsap(skb);
 980         ssap = nfc_llcp_ssap(skb);
 981
 982         llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
 983         if (llcp_sock == NULL) {
 984                 pr_err("Invalid CC\n");
 985                 nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
 986
 987                 return;
 988         }
 989
 990         sk = &llcp_sock->sk;
 991
 992         /* Unlink from connecting and link to the client array */
 993         nfc_llcp_sock_unlink(&local->connecting_sockets, sk);
 994         nfc_llcp_sock_link(&local->sockets, sk);
 995         llcp_sock->dsap = ssap;
 996
 997         nfc_llcp_parse_connection_tlv(llcp_sock, &skb->data[LLCP_HEADER_SIZE],
 998                                       skb->len - LLCP_HEADER_SIZE);
 999
1000         sk->sk_state = LLCP_CONNECTED;
1001         sk->sk_state_change(sk);
1002
1003         nfc_llcp_sock_put(llcp_sock);
1004 }
1005
1006 static void nfc_llcp_recv_dm(struct nfc_llcp_local *local, struct sk_buff *skb)
1007 {
1008         struct nfc_llcp_sock *llcp_sock;
1009         struct sock *sk;
1010         u8 dsap, ssap, reason;
1011
1012         dsap = nfc_llcp_dsap(skb);
1013         ssap = nfc_llcp_ssap(skb);
1014         reason = skb->data[2];
1015
1016         pr_debug("%d %d reason %d\n", ssap, dsap, reason);
1017
1018         switch (reason) {
1019         case LLCP_DM_NOBOUND:
1020         case LLCP_DM_REJ:
1021                 llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1022                 break;
1023
1024         default:
1025                 llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1026                 break;
1027         }
1028
1029         if (llcp_sock == NULL) {
1030                 pr_err("Invalid DM\n");
1031                 return;
1032         }
1033
1034         sk = &llcp_sock->sk;
1035
1036         sk->sk_err = ENXIO;
1037         sk->sk_state = LLCP_CLOSED;
1038         sk->sk_state_change(sk);
1039
1040         nfc_llcp_sock_put(llcp_sock);
1041
1042         return;
1043 }
1044
1045 static void nfc_llcp_rx_work(struct work_struct *work)
1046 {
1047         struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
1048                                                     rx_work);
1049         u8 dsap, ssap, ptype;
1050         struct sk_buff *skb;
1051
1052         skb = local->rx_pending;
1053         if (skb == NULL) {
1054                 pr_debug("No pending SKB\n");
1055                 return;
1056         }
1057
1058         ptype = nfc_llcp_ptype(skb);
1059         dsap = nfc_llcp_dsap(skb);
1060         ssap = nfc_llcp_ssap(skb);
1061
1062         pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
1063
1064         if (ptype != LLCP_PDU_SYMM)
1065                 print_hex_dump(KERN_DEBUG, "LLCP Rx: ", DUMP_PREFIX_OFFSET,
1066                                16, 1, skb->data, skb->len, true);
1067
1068         nfc_llcp_send_to_raw_sock(local, skb, NFC_LLCP_DIRECTION_RX);
1069
1070         switch (ptype) {
1071         case LLCP_PDU_SYMM:
1072                 pr_debug("SYMM\n");
1073                 break;
1074
1075         case LLCP_PDU_CONNECT:
1076                 pr_debug("CONNECT\n");
1077                 nfc_llcp_recv_connect(local, skb);
1078                 break;
1079
1080         case LLCP_PDU_DISC:
1081                 pr_debug("DISC\n");
1082                 nfc_llcp_recv_disc(local, skb);
1083                 break;
1084
1085         case LLCP_PDU_CC:
1086                 pr_debug("CC\n");
1087                 nfc_llcp_recv_cc(local, skb);
1088                 break;
1089
1090         case LLCP_PDU_DM:
1091                 pr_debug("DM\n");
1092                 nfc_llcp_recv_dm(local, skb);
1093                 break;
1094
1095         case LLCP_PDU_I:
1096         case LLCP_PDU_RR:
1097         case LLCP_PDU_RNR:
1098                 pr_debug("I frame\n");
1099                 nfc_llcp_recv_hdlc(local, skb);
1100                 break;
1101
1102         }
1103
1104         queue_work(system_nrt_wq, &local->tx_work);
1105         kfree_skb(local->rx_pending);
1106         local->rx_pending = NULL;
1107
1108         return;
1109 }
1110
1111 void nfc_llcp_recv(void *data, struct sk_buff *skb, int err)
1112 {
1113         struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
1114
1115         pr_debug("Received an LLCP PDU\n");
1116         if (err < 0) {
1117                 pr_err("err %d\n", err);
1118                 return;
1119         }
1120
1121         local->rx_pending = skb_get(skb);
1122         del_timer(&local->link_timer);
1123         queue_work(system_nrt_wq, &local->rx_work);
1124
1125         return;
1126 }
1127
1128 int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb)
1129 {
1130         struct nfc_llcp_local *local;
1131
1132         local = nfc_llcp_find_local(dev);
1133         if (local == NULL)
1134                 return -ENODEV;
1135
1136         local->rx_pending = skb_get(skb);
1137         del_timer(&local->link_timer);
1138         queue_work(system_nrt_wq, &local->rx_work);
1139
1140         return 0;
1141 }
1142
1143 void nfc_llcp_mac_is_down(struct nfc_dev *dev)
1144 {
1145         struct nfc_llcp_local *local;
1146
1147         local = nfc_llcp_find_local(dev);
1148         if (local == NULL)
1149                 return;
1150
1151         /* Close and purge all existing sockets */
1152         nfc_llcp_socket_release(local, true);
1153 }
1154
1155 void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
1156                         u8 comm_mode, u8 rf_mode)
1157 {
1158         struct nfc_llcp_local *local;
1159
1160         pr_debug("rf mode %d\n", rf_mode);
1161
1162         local = nfc_llcp_find_local(dev);
1163         if (local == NULL)
1164                 return;
1165
1166         local->target_idx = target_idx;
1167         local->comm_mode = comm_mode;
1168         local->rf_mode = rf_mode;
1169
1170         if (rf_mode == NFC_RF_INITIATOR) {
1171                 pr_debug("Queueing Tx work\n");
1172
1173                 queue_work(system_nrt_wq, &local->tx_work);
1174         } else {
1175                 mod_timer(&local->link_timer,
1176                           jiffies + msecs_to_jiffies(local->remote_lto));
1177         }
1178 }
1179
1180 int nfc_llcp_register_device(struct nfc_dev *ndev)
1181 {
1182         struct nfc_llcp_local *local;
1183
1184         local = kzalloc(sizeof(struct nfc_llcp_local), GFP_KERNEL);
1185         if (local == NULL)
1186                 return -ENOMEM;
1187
1188         local->dev = ndev;
1189         INIT_LIST_HEAD(&local->list);
1190         kref_init(&local->ref);
1191         mutex_init(&local->sdp_lock);
1192         init_timer(&local->link_timer);
1193         local->link_timer.data = (unsigned long) local;
1194         local->link_timer.function = nfc_llcp_symm_timer;
1195
1196         skb_queue_head_init(&local->tx_queue);
1197         INIT_WORK(&local->tx_work, nfc_llcp_tx_work);
1198
1199         local->rx_pending = NULL;
1200         INIT_WORK(&local->rx_work, nfc_llcp_rx_work);
1201
1202         INIT_WORK(&local->timeout_work, nfc_llcp_timeout_work);
1203
1204         rwlock_init(&local->sockets.lock);
1205         rwlock_init(&local->connecting_sockets.lock);
1206         rwlock_init(&local->raw_sockets.lock);
1207
1208         nfc_llcp_build_gb(local);
1209
1210         local->remote_miu = LLCP_DEFAULT_MIU;
1211         local->remote_lto = LLCP_DEFAULT_LTO;
1212
1213         list_add(&llcp_devices, &local->list);
1214
1215         return 0;
1216 }
1217
1218 void nfc_llcp_unregister_device(struct nfc_dev *dev)
1219 {
1220         struct nfc_llcp_local *local = nfc_llcp_find_local(dev);
1221
1222         if (local == NULL) {
1223                 pr_debug("No such device\n");
1224                 return;
1225         }
1226
1227         nfc_llcp_local_put(local);
1228 }
1229
1230 int __init nfc_llcp_init(void)
1231 {
1232         INIT_LIST_HEAD(&llcp_devices);
1233
1234         return nfc_llcp_sock_init();
1235 }
1236
1237 void nfc_llcp_exit(void)
1238 {
1239         nfc_llcp_sock_exit();
1240 }