net/nfc/llcp_commands.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2011  Intel Corporation. All rights reserved.
   4  */
   5
   6 #define pr_fmt(fmt) "llcp: %s: " fmt, __func__
   7
   8 #include <linux/init.h>
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/nfc.h>
  12
  13 #include <net/nfc/nfc.h>
  14
  15 #include "nfc.h"
  16 #include "llcp.h"
  17
  18 static const u8 llcp_tlv_length[LLCP_TLV_MAX] = {
  19         0,
  20         1, /* VERSION */
  21         2, /* MIUX */
  22         2, /* WKS */
  23         1, /* LTO */
  24         1, /* RW */
  25         0, /* SN */
  26         1, /* OPT */
  27         0, /* SDREQ */
  28         2, /* SDRES */
  29
  30 };
  31
  32 static u8 llcp_tlv8(const u8 *tlv, u8 type)
  33 {
  34         if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
  35                 return 0;
  36
  37         return tlv[2];
  38 }
  39
  40 static u16 llcp_tlv16(const u8 *tlv, u8 type)
  41 {
  42         if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]])
  43                 return 0;
  44
  45         return be16_to_cpu(*((__be16 *)(tlv + 2)));
  46 }
  47
  48
  49 static u8 llcp_tlv_version(const u8 *tlv)
  50 {
  51         return llcp_tlv8(tlv, LLCP_TLV_VERSION);
  52 }
  53
  54 static u16 llcp_tlv_miux(const u8 *tlv)
  55 {
  56         return llcp_tlv16(tlv, LLCP_TLV_MIUX) & 0x7ff;
  57 }
  58
  59 static u16 llcp_tlv_wks(const u8 *tlv)
  60 {
  61         return llcp_tlv16(tlv, LLCP_TLV_WKS);
  62 }
  63
  64 static u16 llcp_tlv_lto(const u8 *tlv)
  65 {
  66         return llcp_tlv8(tlv, LLCP_TLV_LTO);
  67 }
  68
  69 static u8 llcp_tlv_opt(const u8 *tlv)
  70 {
  71         return llcp_tlv8(tlv, LLCP_TLV_OPT);
  72 }
  73
  74 static u8 llcp_tlv_rw(const u8 *tlv)
  75 {
  76         return llcp_tlv8(tlv, LLCP_TLV_RW) & 0xf;
  77 }
  78
  79 u8 *nfc_llcp_build_tlv(u8 type, const u8 *value, u8 value_length, u8 *tlv_length)
  80 {
  81         u8 *tlv, length;
  82
  83         pr_debug("type %d\n", type);
  84
  85         if (type >= LLCP_TLV_MAX)
  86                 return NULL;
  87
  88         length = llcp_tlv_length[type];
  89         if (length == 0 && value_length == 0)
  90                 return NULL;
  91         else if (length == 0)
  92                 length = value_length;
  93
  94         *tlv_length = 2 + length;
  95         tlv = kzalloc(2 + length, GFP_KERNEL);
  96         if (tlv == NULL)
  97                 return tlv;
  98
  99         tlv[0] = type;
 100         tlv[1] = length;
 101         memcpy(tlv + 2, value, length);
 102
 103         return tlv;
 104 }
 105
 106 struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdres_tlv(u8 tid, u8 sap)
 107 {
 108         struct nfc_llcp_sdp_tlv *sdres;
 109         u8 value[2];
 110
 111         sdres = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL);
 112         if (sdres == NULL)
 113                 return NULL;
 114
 115         value[0] = tid;
 116         value[1] = sap;
 117
 118         sdres->tlv = nfc_llcp_build_tlv(LLCP_TLV_SDRES, value, 2,
 119                                         &sdres->tlv_len);
 120         if (sdres->tlv == NULL) {
 121                 kfree(sdres);
 122                 return NULL;
 123         }
 124
 125         sdres->tid = tid;
 126         sdres->sap = sap;
 127
 128         INIT_HLIST_NODE(&sdres->node);
 129
 130         return sdres;
 131 }
 132
 133 struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdreq_tlv(u8 tid, const char *uri,
 134                                                   size_t uri_len)
 135 {
 136         struct nfc_llcp_sdp_tlv *sdreq;
 137
 138         pr_debug("uri: %s, len: %zu\n", uri, uri_len);
 139
 140         /* sdreq->tlv_len is u8, takes uri_len, + 3 for header, + 1 for NULL */
 141         if (WARN_ON_ONCE(uri_len > U8_MAX - 4))
 142                 return NULL;
 143
 144         sdreq = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL);
 145         if (sdreq == NULL)
 146                 return NULL;
 147
 148         sdreq->tlv_len = uri_len + 3;
 149
 150         if (uri[uri_len - 1] == 0)
 151                 sdreq->tlv_len--;
 152
 153         sdreq->tlv = kzalloc(sdreq->tlv_len + 1, GFP_KERNEL);
 154         if (sdreq->tlv == NULL) {
 155                 kfree(sdreq);
 156                 return NULL;
 157         }
 158
 159         sdreq->tlv[0] = LLCP_TLV_SDREQ;
 160         sdreq->tlv[1] = sdreq->tlv_len - 2;
 161         sdreq->tlv[2] = tid;
 162
 163         sdreq->tid = tid;
 164         sdreq->uri = sdreq->tlv + 3;
 165         memcpy(sdreq->uri, uri, uri_len);
 166
 167         sdreq->time = jiffies;
 168
 169         INIT_HLIST_NODE(&sdreq->node);
 170
 171         return sdreq;
 172 }
 173
 174 void nfc_llcp_free_sdp_tlv(struct nfc_llcp_sdp_tlv *sdp)
 175 {
 176         kfree(sdp->tlv);
 177         kfree(sdp);
 178 }
 179
 180 void nfc_llcp_free_sdp_tlv_list(struct hlist_head *head)
 181 {
 182         struct nfc_llcp_sdp_tlv *sdp;
 183         struct hlist_node *n;
 184
 185         hlist_for_each_entry_safe(sdp, n, head, node) {
 186                 hlist_del(&sdp->node);
 187
 188                 nfc_llcp_free_sdp_tlv(sdp);
 189         }
 190 }
 191
 192 int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local *local,
 193                           const u8 *tlv_array, u16 tlv_array_len)
 194 {
 195         const u8 *tlv = tlv_array;
 196         u8 type, length, offset = 0;
 197
 198         pr_debug("TLV array length %d\n", tlv_array_len);
 199
 200         if (local == NULL)
 201                 return -ENODEV;
 202
 203         while (offset < tlv_array_len) {
 204                 type = tlv[0];
 205                 length = tlv[1];
 206
 207                 pr_debug("type 0x%x length %d\n", type, length);
 208
 209                 switch (type) {
 210                 case LLCP_TLV_VERSION:
 211                         local->remote_version = llcp_tlv_version(tlv);
 212                         break;
 213                 case LLCP_TLV_MIUX:
 214                         local->remote_miu = llcp_tlv_miux(tlv) + 128;
 215                         break;
 216                 case LLCP_TLV_WKS:
 217                         local->remote_wks = llcp_tlv_wks(tlv);
 218                         break;
 219                 case LLCP_TLV_LTO:
 220                         local->remote_lto = llcp_tlv_lto(tlv) * 10;
 221                         break;
 222                 case LLCP_TLV_OPT:
 223                         local->remote_opt = llcp_tlv_opt(tlv);
 224                         break;
 225                 default:
 226                         pr_err("Invalid gt tlv value 0x%x\n", type);
 227                         break;
 228                 }
 229
 230                 offset += length + 2;
 231                 tlv += length + 2;
 232         }
 233
 234         pr_debug("version 0x%x miu %d lto %d opt 0x%x wks 0x%x\n",
 235                  local->remote_version, local->remote_miu,
 236                  local->remote_lto, local->remote_opt,
 237                  local->remote_wks);
 238
 239         return 0;
 240 }
 241
 242 int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock *sock,
 243                                   const u8 *tlv_array, u16 tlv_array_len)
 244 {
 245         const u8 *tlv = tlv_array;
 246         u8 type, length, offset = 0;
 247
 248         pr_debug("TLV array length %d\n", tlv_array_len);
 249
 250         if (sock == NULL)
 251                 return -ENOTCONN;
 252
 253         while (offset < tlv_array_len) {
 254                 type = tlv[0];
 255                 length = tlv[1];
 256
 257                 pr_debug("type 0x%x length %d\n", type, length);
 258
 259                 switch (type) {
 260                 case LLCP_TLV_MIUX:
 261                         sock->remote_miu = llcp_tlv_miux(tlv) + 128;
 262                         break;
 263                 case LLCP_TLV_RW:
 264                         sock->remote_rw = llcp_tlv_rw(tlv);
 265                         break;
 266                 case LLCP_TLV_SN:
 267                         break;
 268                 default:
 269                         pr_err("Invalid gt tlv value 0x%x\n", type);
 270                         break;
 271                 }
 272
 273                 offset += length + 2;
 274                 tlv += length + 2;
 275         }
 276
 277         pr_debug("sock %p rw %d miu %d\n", sock,
 278                  sock->remote_rw, sock->remote_miu);
 279
 280         return 0;
 281 }
 282
 283 static struct sk_buff *llcp_add_header(struct sk_buff *pdu,
 284                                        u8 dsap, u8 ssap, u8 ptype)
 285 {
 286         u8 header[2];
 287
 288         pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
 289
 290         header[0] = (u8)((dsap << 2) | (ptype >> 2));
 291         header[1] = (u8)((ptype << 6) | ssap);
 292
 293         pr_debug("header 0x%x 0x%x\n", header[0], header[1]);
 294
 295         skb_put_data(pdu, header, LLCP_HEADER_SIZE);
 296
 297         return pdu;
 298 }
 299
 300 static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, const u8 *tlv,
 301                                     u8 tlv_length)
 302 {
 303         /* XXX Add an skb length check */
 304
 305         if (tlv == NULL)
 306                 return NULL;
 307
 308         skb_put_data(pdu, tlv, tlv_length);
 309
 310         return pdu;
 311 }
 312
 313 static struct sk_buff *llcp_allocate_pdu(struct nfc_llcp_sock *sock,
 314                                          u8 cmd, u16 size)
 315 {
 316         struct sk_buff *skb;
 317         int err;
 318
 319         if (sock->ssap == 0)
 320                 return NULL;
 321
 322         skb = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT,
 323                                  size + LLCP_HEADER_SIZE, &err);
 324         if (skb == NULL) {
 325                 pr_err("Could not allocate PDU\n");
 326                 return NULL;
 327         }
 328
 329         skb = llcp_add_header(skb, sock->dsap, sock->ssap, cmd);
 330
 331         return skb;
 332 }
 333
 334 int nfc_llcp_send_disconnect(struct nfc_llcp_sock *sock)
 335 {
 336         struct sk_buff *skb;
 337         struct nfc_dev *dev;
 338         struct nfc_llcp_local *local;
 339
 340         local = sock->local;
 341         if (local == NULL)
 342                 return -ENODEV;
 343
 344         dev = sock->dev;
 345         if (dev == NULL)
 346                 return -ENODEV;
 347
 348         skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0);
 349         if (skb == NULL)
 350                 return -ENOMEM;
 351
 352         skb_queue_tail(&local->tx_queue, skb);
 353
 354         return 0;
 355 }
 356
 357 int nfc_llcp_send_symm(struct nfc_dev *dev)
 358 {
 359         struct sk_buff *skb;
 360         struct nfc_llcp_local *local;
 361         u16 size = 0;
 362         int err;
 363
 364         local = nfc_llcp_find_local(dev);
 365         if (local == NULL)
 366                 return -ENODEV;
 367
 368         size += LLCP_HEADER_SIZE;
 369         size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
 370
 371         skb = alloc_skb(size, GFP_KERNEL);
 372         if (skb == NULL) {
 373                 err = -ENOMEM;
 374                 goto out;
 375         }
 376
 377         skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
 378
 379         skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM);
 380
 381         __net_timestamp(skb);
 382
 383         nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_TX);
 384
 385         err = nfc_data_exchange(dev, local->target_idx, skb,
 386                                  nfc_llcp_recv, local);
 387 out:
 388         nfc_llcp_local_put(local);
 389         return err;
 390 }
 391
 392 int nfc_llcp_send_connect(struct nfc_llcp_sock *sock)
 393 {
 394         struct nfc_llcp_local *local;
 395         struct sk_buff *skb;
 396         const u8 *service_name_tlv = NULL;
 397         const u8 *miux_tlv = NULL;
 398         const u8 *rw_tlv = NULL;
 399         u8 service_name_tlv_length = 0;
 400         u8 miux_tlv_length,  rw_tlv_length, rw;
 401         int err;
 402         u16 size = 0;
 403         __be16 miux;
 404
 405         local = sock->local;
 406         if (local == NULL)
 407                 return -ENODEV;
 408
 409         if (sock->service_name != NULL) {
 410                 service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN,
 411                                                       sock->service_name,
 412                                                       sock->service_name_len,
 413                                                       &service_name_tlv_length);
 414                 if (!service_name_tlv) {
 415                         err = -ENOMEM;
 416                         goto error_tlv;
 417                 }
 418                 size += service_name_tlv_length;
 419         }
 420
 421         /* If the socket parameters are not set, use the local ones */
 422         miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ?
 423                 local->miux : sock->miux;
 424         rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw;
 425
 426         miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
 427                                       &miux_tlv_length);
 428         if (!miux_tlv) {
 429                 err = -ENOMEM;
 430                 goto error_tlv;
 431         }
 432         size += miux_tlv_length;
 433
 434         rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
 435         if (!rw_tlv) {
 436                 err = -ENOMEM;
 437                 goto error_tlv;
 438         }
 439         size += rw_tlv_length;
 440
 441         pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len);
 442
 443         skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size);
 444         if (skb == NULL) {
 445                 err = -ENOMEM;
 446                 goto error_tlv;
 447         }
 448
 449         llcp_add_tlv(skb, service_name_tlv, service_name_tlv_length);
 450         llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
 451         llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
 452
 453         skb_queue_tail(&local->tx_queue, skb);
 454
 455         err = 0;
 456
 457 error_tlv:
 458         if (err)
 459                 pr_err("error %d\n", err);
 460
 461         kfree(service_name_tlv);
 462         kfree(miux_tlv);
 463         kfree(rw_tlv);
 464
 465         return err;
 466 }
 467
 468 int nfc_llcp_send_cc(struct nfc_llcp_sock *sock)
 469 {
 470         struct nfc_llcp_local *local;
 471         struct sk_buff *skb;
 472         const u8 *miux_tlv = NULL;
 473         const u8 *rw_tlv = NULL;
 474         u8 miux_tlv_length, rw_tlv_length, rw;
 475         int err;
 476         u16 size = 0;
 477         __be16 miux;
 478
 479         local = sock->local;
 480         if (local == NULL)
 481                 return -ENODEV;
 482
 483         /* If the socket parameters are not set, use the local ones */
 484         miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ?
 485                 local->miux : sock->miux;
 486         rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw;
 487
 488         miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0,
 489                                       &miux_tlv_length);
 490         if (!miux_tlv) {
 491                 err = -ENOMEM;
 492                 goto error_tlv;
 493         }
 494         size += miux_tlv_length;
 495
 496         rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length);
 497         if (!rw_tlv) {
 498                 err = -ENOMEM;
 499                 goto error_tlv;
 500         }
 501         size += rw_tlv_length;
 502
 503         skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size);
 504         if (skb == NULL) {
 505                 err = -ENOMEM;
 506                 goto error_tlv;
 507         }
 508
 509         llcp_add_tlv(skb, miux_tlv, miux_tlv_length);
 510         llcp_add_tlv(skb, rw_tlv, rw_tlv_length);
 511
 512         skb_queue_tail(&local->tx_queue, skb);
 513
 514         err = 0;
 515
 516 error_tlv:
 517         if (err)
 518                 pr_err("error %d\n", err);
 519
 520         kfree(miux_tlv);
 521         kfree(rw_tlv);
 522
 523         return err;
 524 }
 525
 526 static struct sk_buff *nfc_llcp_allocate_snl(struct nfc_llcp_local *local,
 527                                              size_t tlv_length)
 528 {
 529         struct sk_buff *skb;
 530         struct nfc_dev *dev;
 531         u16 size = 0;
 532
 533         if (local == NULL)
 534                 return ERR_PTR(-ENODEV);
 535
 536         dev = local->dev;
 537         if (dev == NULL)
 538                 return ERR_PTR(-ENODEV);
 539
 540         size += LLCP_HEADER_SIZE;
 541         size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
 542         size += tlv_length;
 543
 544         skb = alloc_skb(size, GFP_KERNEL);
 545         if (skb == NULL)
 546                 return ERR_PTR(-ENOMEM);
 547
 548         skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
 549
 550         skb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL);
 551
 552         return skb;
 553 }
 554
 555 int nfc_llcp_send_snl_sdres(struct nfc_llcp_local *local,
 556                             struct hlist_head *tlv_list, size_t tlvs_len)
 557 {
 558         struct nfc_llcp_sdp_tlv *sdp;
 559         struct hlist_node *n;
 560         struct sk_buff *skb;
 561
 562         skb = nfc_llcp_allocate_snl(local, tlvs_len);
 563         if (IS_ERR(skb))
 564                 return PTR_ERR(skb);
 565
 566         hlist_for_each_entry_safe(sdp, n, tlv_list, node) {
 567                 skb_put_data(skb, sdp->tlv, sdp->tlv_len);
 568
 569                 hlist_del(&sdp->node);
 570
 571                 nfc_llcp_free_sdp_tlv(sdp);
 572         }
 573
 574         skb_queue_tail(&local->tx_queue, skb);
 575
 576         return 0;
 577 }
 578
 579 int nfc_llcp_send_snl_sdreq(struct nfc_llcp_local *local,
 580                             struct hlist_head *tlv_list, size_t tlvs_len)
 581 {
 582         struct nfc_llcp_sdp_tlv *sdreq;
 583         struct hlist_node *n;
 584         struct sk_buff *skb;
 585
 586         skb = nfc_llcp_allocate_snl(local, tlvs_len);
 587         if (IS_ERR(skb))
 588                 return PTR_ERR(skb);
 589
 590         mutex_lock(&local->sdreq_lock);
 591
 592         if (hlist_empty(&local->pending_sdreqs))
 593                 mod_timer(&local->sdreq_timer,
 594                           jiffies + msecs_to_jiffies(3 * local->remote_lto));
 595
 596         hlist_for_each_entry_safe(sdreq, n, tlv_list, node) {
 597                 pr_debug("tid %d for %s\n", sdreq->tid, sdreq->uri);
 598
 599                 skb_put_data(skb, sdreq->tlv, sdreq->tlv_len);
 600
 601                 hlist_del(&sdreq->node);
 602
 603                 hlist_add_head(&sdreq->node, &local->pending_sdreqs);
 604         }
 605
 606         mutex_unlock(&local->sdreq_lock);
 607
 608         skb_queue_tail(&local->tx_queue, skb);
 609
 610         return 0;
 611 }
 612
 613 int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason)
 614 {
 615         struct sk_buff *skb;
 616         struct nfc_dev *dev;
 617         u16 size = 1; /* Reason code */
 618
 619         pr_debug("Sending DM reason 0x%x\n", reason);
 620
 621         if (local == NULL)
 622                 return -ENODEV;
 623
 624         dev = local->dev;
 625         if (dev == NULL)
 626                 return -ENODEV;
 627
 628         size += LLCP_HEADER_SIZE;
 629         size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
 630
 631         skb = alloc_skb(size, GFP_KERNEL);
 632         if (skb == NULL)
 633                 return -ENOMEM;
 634
 635         skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
 636
 637         skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM);
 638
 639         skb_put_data(skb, &reason, 1);
 640
 641         skb_queue_head(&local->tx_queue, skb);
 642
 643         return 0;
 644 }
 645
 646 int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock,
 647                           struct msghdr *msg, size_t len)
 648 {
 649         struct sk_buff *pdu;
 650         struct sock *sk = &sock->sk;
 651         struct nfc_llcp_local *local;
 652         size_t frag_len = 0, remaining_len;
 653         u8 *msg_data, *msg_ptr;
 654         u16 remote_miu;
 655
 656         pr_debug("Send I frame len %zd\n", len);
 657
 658         local = sock->local;
 659         if (local == NULL)
 660                 return -ENODEV;
 661
 662         /* Remote is ready but has not acknowledged our frames */
 663         if((sock->remote_ready &&
 664             skb_queue_len(&sock->tx_pending_queue) >= sock->remote_rw &&
 665             skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
 666                 pr_err("Pending queue is full %d frames\n",
 667                        skb_queue_len(&sock->tx_pending_queue));
 668                 return -ENOBUFS;
 669         }
 670
 671         /* Remote is not ready and we've been queueing enough frames */
 672         if ((!sock->remote_ready &&
 673              skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) {
 674                 pr_err("Tx queue is full %d frames\n",
 675                        skb_queue_len(&sock->tx_queue));
 676                 return -ENOBUFS;
 677         }
 678
 679         msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN);
 680         if (msg_data == NULL)
 681                 return -ENOMEM;
 682
 683         if (memcpy_from_msg(msg_data, msg, len)) {
 684                 kfree(msg_data);
 685                 return -EFAULT;
 686         }
 687
 688         remaining_len = len;
 689         msg_ptr = msg_data;
 690
 691         do {
 692                 remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
 693                                 LLCP_DEFAULT_MIU : sock->remote_miu;
 694
 695                 frag_len = min_t(size_t, remote_miu, remaining_len);
 696
 697                 pr_debug("Fragment %zd bytes remaining %zd",
 698                          frag_len, remaining_len);
 699
 700                 pdu = llcp_allocate_pdu(sock, LLCP_PDU_I,
 701                                         frag_len + LLCP_SEQUENCE_SIZE);
 702                 if (pdu == NULL) {
 703                         kfree(msg_data);
 704                         return -ENOMEM;
 705                 }
 706
 707                 skb_put(pdu, LLCP_SEQUENCE_SIZE);
 708
 709                 if (likely(frag_len > 0))
 710                         skb_put_data(pdu, msg_ptr, frag_len);
 711
 712                 skb_queue_tail(&sock->tx_queue, pdu);
 713
 714                 lock_sock(sk);
 715
 716                 nfc_llcp_queue_i_frames(sock);
 717
 718                 release_sock(sk);
 719
 720                 remaining_len -= frag_len;
 721                 msg_ptr += frag_len;
 722         } while (remaining_len > 0);
 723
 724         kfree(msg_data);
 725
 726         return len;
 727 }
 728
 729 int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap,
 730                            struct msghdr *msg, size_t len)
 731 {
 732         struct sk_buff *pdu;
 733         struct nfc_llcp_local *local;
 734         size_t frag_len = 0, remaining_len;
 735         u8 *msg_ptr, *msg_data;
 736         u16 remote_miu;
 737         int err;
 738
 739         pr_debug("Send UI frame len %zd\n", len);
 740
 741         local = sock->local;
 742         if (local == NULL)
 743                 return -ENODEV;
 744
 745         msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN);
 746         if (msg_data == NULL)
 747                 return -ENOMEM;
 748
 749         if (memcpy_from_msg(msg_data, msg, len)) {
 750                 kfree(msg_data);
 751                 return -EFAULT;
 752         }
 753
 754         remaining_len = len;
 755         msg_ptr = msg_data;
 756
 757         do {
 758                 remote_miu = sock->remote_miu > LLCP_MAX_MIU ?
 759                                 local->remote_miu : sock->remote_miu;
 760
 761                 frag_len = min_t(size_t, remote_miu, remaining_len);
 762
 763                 pr_debug("Fragment %zd bytes remaining %zd",
 764                          frag_len, remaining_len);
 765
 766                 pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, 0,
 767                                          frag_len + LLCP_HEADER_SIZE, &err);
 768                 if (pdu == NULL) {
 769                         pr_err("Could not allocate PDU (error=%d)\n", err);
 770                         len -= remaining_len;
 771                         if (len == 0)
 772                                 len = err;
 773                         break;
 774                 }
 775
 776                 pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI);
 777
 778                 if (likely(frag_len > 0))
 779                         skb_put_data(pdu, msg_ptr, frag_len);
 780
 781                 /* No need to check for the peer RW for UI frames */
 782                 skb_queue_tail(&local->tx_queue, pdu);
 783
 784                 remaining_len -= frag_len;
 785                 msg_ptr += frag_len;
 786         } while (remaining_len > 0);
 787
 788         kfree(msg_data);
 789
 790         return len;
 791 }
 792
 793 int nfc_llcp_send_rr(struct nfc_llcp_sock *sock)
 794 {
 795         struct sk_buff *skb;
 796         struct nfc_llcp_local *local;
 797
 798         pr_debug("Send rr nr %d\n", sock->recv_n);
 799
 800         local = sock->local;
 801         if (local == NULL)
 802                 return -ENODEV;
 803
 804         skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE);
 805         if (skb == NULL)
 806                 return -ENOMEM;
 807
 808         skb_put(skb, LLCP_SEQUENCE_SIZE);
 809
 810         skb->data[2] = sock->recv_n;
 811
 812         skb_queue_head(&local->tx_queue, skb);
 813
 814         return 0;
 815 }