net/nfc/llcp_commands.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, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #define pr_fmt(fmt) "llcp: %s: " fmt, __func__
  19
  20 #include <linux/init.h>
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/nfc.h>
  24
  25 #include <net/nfc/nfc.h>
  26
  27 #include "nfc.h"
  28 #include "llcp.h"
  29
  30 static u8 llcp_tlv_length[LLCP_TLV_MAX] = {
  31         0,
  32         1, /* VERSION */
  33         2, /* MIUX */
  34         2, /* WKS */
  35         1, /* LTO */
  36         1, /* RW */
  37         0, /* SN */
  38         1, /* OPT */
  39         0, /* SDREQ */
  40         2, /* SDRES */
  41
  42 };
  43
  44 static u8 llcp_tlv8(u8 *tlv, u8 type)
  45 {
  46         if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
  47                 return 0;
  48
  49         return tlv[2];
  50 }
  51
  52 static u16 llcp_tlv16(u8 *tlv, u8 type)
  53 {
  54         if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
  55                 return 0;
  56
  57         return be16_to_cpu(*((__be16 *)(tlv + 2)));
  58 }
  59
  60
  61 static u8 llcp_tlv_version(u8 *tlv)
  62 {
  63         return llcp_tlv8(tlv, LLCP_TLV_VERSION);
  64 }
  65
  66 static u16 llcp_tlv_miux(u8 *tlv)
  67 {
  68         return llcp_tlv16(tlv, LLCP_TLV_MIUX) & 0x7ff;
  69 }
  70
  71 static u16 llcp_tlv_wks(u8 *tlv)
  72 {
  73         return llcp_tlv16(tlv, LLCP_TLV_WKS);
  74 }
  75
  76 static u16 llcp_tlv_lto(u8 *tlv)
  77 {
  78         return llcp_tlv8(tlv, LLCP_TLV_LTO);
  79 }
  80
  81 static u8 llcp_tlv_opt(u8 *tlv)
  82 {
  83         return llcp_tlv8(tlv, LLCP_TLV_OPT);
  84 }
  85
  86 static u8 llcp_tlv_rw(u8 *tlv)
  87 {
  88         return llcp_tlv8(tlv, LLCP_TLV_RW) & 0xf;
  89 }
  90
  91 u8 *nfc_llcp_build_tlv(u8 type, u8 *value, u8 value_length, u8 *tlv_length)
  92 {
  93         u8 *tlv, length;
  94
  95         pr_debug("type %d\n", type);
  96
  97         if (type >= LLCP_TLV_MAX)
  98                 return NULL;
  99
 100         length = llcp_tlv_length[type];
 101         if (length == 0 && value_length == 0)
 102                 return NULL;
 103         else if (length == 0)
 104                 length = value_length;
 105
 106         *tlv_length = 2 + length;
 107         tlv = kzalloc(2 + length, GFP_KERNEL);
 108         if (tlv == NULL)
 109                 return tlv;
 110
 111         tlv[0] = type;
 112         tlv[1] = length;
 113         memcpy(tlv + 2, value, length);
 114
 115         return tlv;
 116 }
 117
 118 struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdres_tlv(u8 tid, u8 sap)
 119 {
 120         struct nfc_llcp_sdp_tlv *sdres;
 121         u8 value[2];
 122
 123         sdres = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL);
 124         if (sdres == NULL)
 125                 return NULL;
 126
 127         value[0] = tid;
 128         value[1] = sap;
 129
 130         sdres->tlv = nfc_llcp_build_tlv(LLCP_TLV_SDRES, value, 2,
 131                                         &sdres->tlv_len);
 132         if (sdres->tlv == NULL) {
 133                 kfree(sdres);
 134                 return NULL;
 135         }
 136
 137         sdres->tid = tid;
 138         sdres->sap = sap;
 139
 140         INIT_HLIST_NODE(&sdres->node);
 141
 142         return sdres;
 143 }
 144
 145 struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdreq_tlv(u8 tid, char *uri,
 146                                                   size_t uri_len)
 147 {
 148         struct nfc_llcp_sdp_tlv *sdreq;
 149
 150         pr_debug("uri: %s, len: %zu\n", uri, uri_len);
 151
 152         /* sdreq->tlv_len is u8, takes uri_len, + 3 for header, + 1 for NULL */
 153         if (WARN_ON_ONCE(uri_len > U8_MAX - 4))
 154                 return NULL;
 155
 156         sdreq = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL);
 157         if (sdreq == NULL)
 158                 return NULL;
 159
 160         sdreq->tlv_len = uri_len + 3;
 161
 162         if (uri[uri_len - 1] == 0)
 163                 sdreq->tlv_len--;
 164
 165         sdreq->tlv = kzalloc(sdreq->tlv_len + 1, GFP_KERNEL);
 166         if (sdreq->tlv == NULL) {
 167                 kfree(sdreq);
 168                 return NULL;
 169         }
 170
 171         sdreq->tlv[0] = LLCP_TLV_SDREQ;
 172         sdreq->tlv[1] = sdreq->tlv_len - 2;
 173         sdreq->tlv[2] = tid;
 174
 175         sdreq->tid = tid;
 176         sdreq->uri = sdreq->tlv + 3;
 177         memcpy(sdreq->uri, uri, uri_len);
 178
 179         sdreq->time = jiffies;
 180
 181         INIT_HLIST_NODE(&sdreq->node);
 182
 183         return sdreq;
 184 }
 185
 186 void nfc_llcp_free_sdp_tlv(struct nfc_llcp_sdp_tlv *sdp)
 187 {
 188         kfree(sdp->tlv);
 189         kfree(sdp);
 190 }
 191
 192 void nfc_llcp_free_sdp_tlv_list(struct hlist_head *head)
 193 {
 194         struct nfc_llcp_sdp_tlv *sdp;
 195         struct hlist_node *n;
 196
 197         hlist_for_each_entry_safe(sdp, n, head, node) {
 198                 hlist_del(&sdp->node);
 199
 200                 nfc_llcp_free_sdp_tlv(sdp);
 201         }
 202 }
 203
 204 int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local *local,
 205                           u8 *tlv_array, u16 tlv_array_len)
 206 {
 207         u8 *tlv = tlv_array, type, length, offset = 0;
 208
 209         pr_debug("TLV array length %d\n", tlv_array_len);
 210
 211         if (local == NULL)
 212                 return -ENODEV;
 213
 214         while (offset < tlv_array_len) {
 215                 type = tlv[0];
 216                 length = tlv[1];
 217
 218                 pr_debug("type 0x%x length %d\n", type, length);
 219
 220                 switch (type) {
 221                 case LLCP_TLV_VERSION:
 222                         local->remote_version = llcp_tlv_version(tlv);
 223                         break;
 224                 case LLCP_TLV_MIUX:
 225                         local->remote_miu = llcp_tlv_miux(tlv) + 128;
 226                         break;
 227                 case LLCP_TLV_WKS:
 228                         local->remote_wks = llcp_tlv_wks(tlv);
 229                         break;
 230                 case LLCP_TLV_LTO:
 231                         local->remote_lto = llcp_tlv_lto(tlv) * 10;
 232                         break;
 233                 case LLCP_TLV_OPT:
 234                         local->remote_opt = llcp_tlv_opt(tlv);
 235                         break;
 236                 default:
 237                         pr_err("Invalid gt tlv value 0x%x\n", type);
 238                         break;
 239                 }
 240
 241                 offset += length + 2;
 242                 tlv += length + 2;
 243         }
 244
 245         pr_debug("version 0x%x miu %d lto %d opt 0x%x wks 0x%x\n",
 246                  local->remote_version, local->remote_miu,
 247                  local->remote_lto, local->remote_opt,
 248                  local->remote_wks);
 249
 250         return 0;
 251 }
 252
 253 int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock *sock,
 254                                   u8 *tlv_array, u16 tlv_array_len)
 255 {
 256         u8 *tlv = tlv_array, type, length, offset = 0;
 257
 258         pr_debug("TLV array length %d\n", tlv_array_len);
 259
 260         if (sock == NULL)
 261                 return -ENOTCONN;
 262
 263         while (offset < tlv_array_len) {
 264                 type = tlv[0];
 265                 length = tlv[1];
 266
 267                 pr_debug("type 0x%x length %d\n", type, length);
 268
 269                 switch (type) {
 270                 case LLCP_TLV_MIUX:
 271                         sock->remote_miu = llcp_tlv_miux(tlv) + 128;
 272                         break;
 273                 case LLCP_TLV_RW:
 274                         sock->remote_rw = llcp_tlv_rw(tlv);
 275                         break;
 276                 case LLCP_TLV_SN:
 277                         break;
 278                 default:
 279                         pr_err("Invalid gt tlv value 0x%x\n", type);
 280                         break;
 281                 }
 282
 283                 offset += length + 2;
 284                 tlv += length + 2;
 285         }
 286
 287         pr_debug("sock %p rw %d miu %d\n", sock,
 288                  sock->remote_rw, sock->remote_miu);
 289
 290         return 0;
 291 }
 292
 293 static struct sk_buff *llcp_add_header(struct sk_buff *pdu,
 294                                        u8 dsap, u8 ssap, u8 ptype)
 295 {
 296         u8 header[2];
 297
 298         pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
 299
 300         header[0] = (u8)((dsap << 2) | (ptype >> 2));
 301         header[1] = (u8)((ptype << 6) | ssap);
 302
 303         pr_debug("header 0x%x 0x%x\n", header[0], header[1]);
 304
 305         skb_put_data(pdu, header, LLCP_HEADER_SIZE);
 306
 307         return pdu;
 308 }
 309
 310 static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, u8 *tlv,
 311                                     u8 tlv_length)
 312 {
 313         /* XXX Add an skb length check */
 314
 315         if (tlv == NULL)
 316                 return NULL;
 317
 318         skb_put_data(pdu, tlv, tlv_length);
 319
 320         return pdu;
 321 }
 322
 323 static struct sk_buff *llcp_allocate_pdu(struct nfc_llcp_sock *sock,
 324                                          u8 cmd, u16 size)
 325 {
 326         struct sk_buff *skb;
 327         int err;
 328
 329         if (sock->ssap == 0)
 330                 return NULL;
 331
 332         skb = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT,
 333                                  size + LLCP_HEADER_SIZE, &err);
 334         if (skb == NULL) {
 335                 pr_err("Could not allocate PDU\n");
 336                 return NULL;
 337         }
 338
 339         skb = llcp_add_header(skb, sock->dsap, sock->ssap, cmd);
 340
 341         return skb;
 342 }
 343
 344 int nfc_llcp_send_disconnect(struct nfc_llcp_sock *sock)
 345 {
 346         struct sk_buff *skb;
 347         struct nfc_dev *dev;
 348         struct nfc_llcp_local *local;
 349
 350         pr_debug("Sending DISC\n");
 351
 352         local = sock->local;
 353         if (local == NULL)
 354                 return -ENODEV;
 355
 356         dev = sock->dev;
 357         if (dev == NULL)
 358                 return -ENODEV;
 359
 360         skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0);
 361         if (skb == NULL)
 362                 return -ENOMEM;
 363
 364         skb_queue_tail(&local->tx_queue, skb);
 365
 366         return 0;
 367 }
 368
 369 int nfc_llcp_send_symm(struct nfc_dev *dev)
 370 {
 371         struct sk_buff *skb;
 372         struct nfc_llcp_local *local;
 373         u16 size = 0;
 374
 375         pr_debug("Sending SYMM\n");
 376
 377         local = nfc_llcp_find_local(dev);
 378         if (local == NULL)
 379                 return -ENODEV;
 380
 381         size += LLCP_HEADER_SIZE;
 382         size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
 383
 384         skb = alloc_skb(size, GFP_KERNEL);
 385         if (skb == NULL)
 386                 return -ENOMEM;
 387
 388         skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
 389
 390         skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM);
 391
 392         __net_timestamp(skb);
 393
 394         nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_TX);
 395
 396         return nfc_data_exchange(dev, local->target_idx, skb,
 397                                  nfc_llcp_recv, local);
 398 }
 399
 400 int nfc_llcp_send_connect(struct nfc_llcp_sock *sock)
 401 {
 402         struct nfc_llcp_local *local;
 403         struct sk_buff *skb;
 404         u8 *service_name_tlv = NULL, service_name_tlv_length;
 405         u8 *miux_tlv = NULL, miux_tlv_length;
 406         u8 *rw_tlv = NULL, rw_tlv_length, rw;
 407         int err;
 408         u16 size = 0;
 409         __be16 miux;
 410
 411         pr_debug("Sending CONNECT\n");
 412
 413         local = sock->local;
 414         if (local == NULL)
 415                 return -ENODEV;
 416
 417         if (sock->service_name != NULL) {
 418                 service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN,
 419                                                       sock->service_name,
 420                                                       sock->service_name_len,
 421                                                       &service_name_tlv_length);
 422                 size += service_name_tlv_length;
 423         }
 424
 425         /* If the socket parameters are not set, use the local ones */
 426         miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ?
 427                 local->miux : sock->miux;
 428         rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw;
 429
 430         miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
 431                                       &miux_tlv_length);
 432         size += miux_tlv_length;
 433
 434         rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
 435         size += rw_tlv_length;
 436
 437         pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len);
 438
 439         skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size);
 440         if (skb == NULL) {
 441                 err = -ENOMEM;
 442                 goto error_tlv;
 443         }
 444
 445         llcp_add_tlv(skb, service_name_tlv, service_name_tlv_length);
 446         llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
 447         llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
 448
 449         skb_queue_tail(&local->tx_queue, skb);
 450
 451         err = 0;
 452
 453 error_tlv:
 454         if (err)
 455                 pr_err("error %d\n", err);
 456
 457         kfree(service_name_tlv);
 458         kfree(miux_tlv);
 459         kfree(rw_tlv);
 460
 461         return err;
 462 }
 463
 464 int nfc_llcp_send_cc(struct nfc_llcp_sock *sock)
 465 {
 466         struct nfc_llcp_local *local;
 467         struct sk_buff *skb;
 468         u8 *miux_tlv = NULL, miux_tlv_length;
 469         u8 *rw_tlv = NULL, rw_tlv_length, rw;
 470         int err;
 471         u16 size = 0;
 472         __be16 miux;
 473
 474         pr_debug("Sending CC\n");
 475
 476         local = sock->local;
 477         if (local == NULL)
 478                 return -ENODEV;
 479
 480         /* If the socket parameters are not set, use the local ones */
 481         miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ?
 482                 local->miux : sock->miux;
 483         rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw;
 484
 485         miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
 486                                       &miux_tlv_length);
 487         size += miux_tlv_length;
 488
 489         rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
 490         size += rw_tlv_length;
 491
 492         skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size);
 493         if (skb == NULL) {
 494                 err = -ENOMEM;
 495                 goto error_tlv;
 496         }
 497
 498         llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
 499         llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
 500
 501         skb_queue_tail(&local->tx_queue, skb);
 502
 503         err = 0;
 504
 505 error_tlv:
 506         if (err)
 507                 pr_err("error %d\n", err);
 508
 509         kfree(miux_tlv);
 510         kfree(rw_tlv);
 511
 512         return err;
 513 }
 514
 515 static struct sk_buff *nfc_llcp_allocate_snl(struct nfc_llcp_local *local,
 516                                              size_t tlv_length)
 517 {
 518         struct sk_buff *skb;
 519         struct nfc_dev *dev;
 520         u16 size = 0;
 521
 522         if (local == NULL)
 523                 return ERR_PTR(-ENODEV);
 524
 525         dev = local->dev;
 526         if (dev == NULL)
 527                 return ERR_PTR(-ENODEV);
 528
 529         size += LLCP_HEADER_SIZE;
 530         size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
 531         size += tlv_length;
 532
 533         skb = alloc_skb(size, GFP_KERNEL);
 534         if (skb == NULL)
 535                 return ERR_PTR(-ENOMEM);
 536
 537         skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
 538
 539         skb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL);
 540
 541         return skb;
 542 }
 543
 544 int nfc_llcp_send_snl_sdres(struct nfc_llcp_local *local,
 545                             struct hlist_head *tlv_list, size_t tlvs_len)
 546 {
 547         struct nfc_llcp_sdp_tlv *sdp;
 548         struct hlist_node *n;
 549         struct sk_buff *skb;
 550
 551         skb = nfc_llcp_allocate_snl(local, tlvs_len);
 552         if (IS_ERR(skb))
 553                 return PTR_ERR(skb);
 554
 555         hlist_for_each_entry_safe(sdp, n, tlv_list, node) {
 556                 skb_put_data(skb, sdp->tlv, sdp->tlv_len);
 557
 558                 hlist_del(&sdp->node);
 559
 560                 nfc_llcp_free_sdp_tlv(sdp);
 561         }
 562
 563         skb_queue_tail(&local->tx_queue, skb);
 564
 565         return 0;
 566 }
 567
 568 int nfc_llcp_send_snl_sdreq(struct nfc_llcp_local *local,
 569                             struct hlist_head *tlv_list, size_t tlvs_len)
 570 {
 571         struct nfc_llcp_sdp_tlv *sdreq;
 572         struct hlist_node *n;
 573         struct sk_buff *skb;
 574
 575         skb = nfc_llcp_allocate_snl(local, tlvs_len);
 576         if (IS_ERR(skb))
 577                 return PTR_ERR(skb);
 578
 579         mutex_lock(&local->sdreq_lock);
 580
 581         if (hlist_empty(&local->pending_sdreqs))
 582                 mod_timer(&local->sdreq_timer,
 583                           jiffies + msecs_to_jiffies(3 * local->remote_lto));
 584
 585         hlist_for_each_entry_safe(sdreq, n, tlv_list, node) {
 586                 pr_debug("tid %d for %s\n", sdreq->tid, sdreq->uri);
 587
 588                 skb_put_data(skb, sdreq->tlv, sdreq->tlv_len);
 589
 590                 hlist_del(&sdreq->node);
 591
 592                 hlist_add_head(&sdreq->node, &local->pending_sdreqs);
 593         }
 594
 595         mutex_unlock(&local->sdreq_lock);
 596
 597         skb_queue_tail(&local->tx_queue, skb);
 598
 599         return 0;
 600 }
 601
 602 int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason)
 603 {
 604         struct sk_buff *skb;
 605         struct nfc_dev *dev;
 606         u16 size = 1; /* Reason code */
 607
 608         pr_debug("Sending DM reason 0x%x\n", reason);
 609
 610         if (local == NULL)
 611                 return -ENODEV;
 612
 613         dev = local->dev;
 614         if (dev == NULL)
 615                 return -ENODEV;
 616
 617         size += LLCP_HEADER_SIZE;
 618         size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
 619
 620         skb = alloc_skb(size, GFP_KERNEL);
 621         if (skb == NULL)
 622                 return -ENOMEM;
 623
 624         skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
 625
 626         skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM);
 627
 628         skb_put_data(skb, &reason, 1);
 629
 630         skb_queue_head(&local->tx_queue, skb);
 631
 632         return 0;
 633 }
 634
 635 int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock,
 636                           struct msghdr *msg, size_t len)
 637 {
 638         struct sk_buff *pdu;
 639         struct sock *sk = &sock->sk;
 640         struct nfc_llcp_local *local;
 641         size_t frag_len = 0, remaining_len;
 642         u8 *msg_data, *msg_ptr;
 643         u16 remote_miu;
 644
 645         pr_debug("Send I frame len %zd\n", len);
 646
 647         local = sock->local;
 648         if (local == NULL)
 649                 return -ENODEV;
 650
 651         /* Remote is ready but has not acknowledged our frames */
 652         if((sock->remote_ready &&
 653             skb_queue_len(&sock->tx_pending_queue) >= sock->remote_rw &&
 654             skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
 655                 pr_err("Pending queue is full %d frames\n",
 656                        skb_queue_len(&sock->tx_pending_queue));
 657                 return -ENOBUFS;
 658         }
 659
 660         /* Remote is not ready and we've been queueing enough frames */
 661         if ((!sock->remote_ready &&
 662              skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
 663                 pr_err("Tx queue is full %d frames\n",
 664                        skb_queue_len(&sock->tx_queue));
 665                 return -ENOBUFS;
 666         }
 667
 668         msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN);
 669         if (msg_data == NULL)
 670                 return -ENOMEM;
 671
 672         if (memcpy_from_msg(msg_data, msg, len)) {
 673                 kfree(msg_data);
 674                 return -EFAULT;
 675         }
 676
 677         remaining_len = len;
 678         msg_ptr = msg_data;
 679
 680         do {
 681                 remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
 682                                 LLCP_DEFAULT_MIU : sock->remote_miu;
 683
 684                 frag_len = min_t(size_t, remote_miu, remaining_len);
 685
 686                 pr_debug("Fragment %zd bytes remaining %zd",
 687                          frag_len, remaining_len);
 688
 689                 pdu = llcp_allocate_pdu(sock, LLCP_PDU_I,
 690                                         frag_len + LLCP_SEQUENCE_SIZE);
 691                 if (pdu == NULL) {
 692                         kfree(msg_data);
 693                         return -ENOMEM;
 694                 }
 695
 696                 skb_put(pdu, LLCP_SEQUENCE_SIZE);
 697
 698                 if (likely(frag_len > 0))
 699                         skb_put_data(pdu, msg_ptr, frag_len);
 700
 701                 skb_queue_tail(&sock->tx_queue, pdu);
 702
 703                 lock_sock(sk);
 704
 705                 nfc_llcp_queue_i_frames(sock);
 706
 707                 release_sock(sk);
 708
 709                 remaining_len -= frag_len;
 710                 msg_ptr += frag_len;
 711         } while (remaining_len > 0);
 712
 713         kfree(msg_data);
 714
 715         return len;
 716 }
 717
 718 int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap,
 719                            struct msghdr *msg, size_t len)
 720 {
 721         struct sk_buff *pdu;
 722         struct nfc_llcp_local *local;
 723         size_t frag_len = 0, remaining_len;
 724         u8 *msg_ptr, *msg_data;
 725         u16 remote_miu;
 726         int err;
 727
 728         pr_debug("Send UI frame len %zd\n", len);
 729
 730         local = sock->local;
 731         if (local == NULL)
 732                 return -ENODEV;
 733
 734         msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN);
 735         if (msg_data == NULL)
 736                 return -ENOMEM;
 737
 738         if (memcpy_from_msg(msg_data, msg, len)) {
 739                 kfree(msg_data);
 740                 return -EFAULT;
 741         }
 742
 743         remaining_len = len;
 744         msg_ptr = msg_data;
 745
 746         do {
 747                 remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
 748                                 local->remote_miu : sock->remote_miu;
 749
 750                 frag_len = min_t(size_t, remote_miu, remaining_len);
 751
 752                 pr_debug("Fragment %zd bytes remaining %zd",
 753                          frag_len, remaining_len);
 754
 755                 pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, 0,
 756                                          frag_len + LLCP_HEADER_SIZE, &err);
 757                 if (pdu == NULL) {
 758                         pr_err("Could not allocate PDU (error=%d)\n", err);
 759                         len -= remaining_len;
 760                         if (len == 0)
 761                                 len = err;
 762                         break;
 763                 }
 764
 765                 pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI);
 766
 767                 if (likely(frag_len > 0))
 768                         skb_put_data(pdu, msg_ptr, frag_len);
 769
 770                 /* No need to check for the peer RW for UI frames */
 771                 skb_queue_tail(&local->tx_queue, pdu);
 772
 773                 remaining_len -= frag_len;
 774                 msg_ptr += frag_len;
 775         } while (remaining_len > 0);
 776
 777         kfree(msg_data);
 778
 779         return len;
 780 }
 781
 782 int nfc_llcp_send_rr(struct nfc_llcp_sock *sock)
 783 {
 784         struct sk_buff *skb;
 785         struct nfc_llcp_local *local;
 786
 787         pr_debug("Send rr nr %d\n", sock->recv_n);
 788
 789         local = sock->local;
 790         if (local == NULL)
 791                 return -ENODEV;
 792
 793         skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE);
 794         if (skb == NULL)
 795                 return -ENOMEM;
 796
 797         skb_put(skb, LLCP_SEQUENCE_SIZE);
 798
 799         skb->data[2] = sock->recv_n;
 800
 801         skb_queue_head(&local->tx_queue, skb);
 802
 803         return 0;
 804 }