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 pr_debug("Sending DISC\n"); 341 342 local = sock->local; 343 if (local == NULL) 344 return -ENODEV; 345 346 dev = sock->dev; 347 if (dev == NULL) 348 return -ENODEV; 349 350 skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0); 351 if (skb == NULL) 352 return -ENOMEM; 353 354 skb_queue_tail(&local->tx_queue, skb); 355 356 return 0; 357 } 358 359 int nfc_llcp_send_symm(struct nfc_dev *dev) 360 { 361 struct sk_buff *skb; 362 struct nfc_llcp_local *local; 363 u16 size = 0; 364 365 pr_debug("Sending SYMM\n"); 366 367 local = nfc_llcp_find_local(dev); 368 if (local == NULL) 369 return -ENODEV; 370 371 size += LLCP_HEADER_SIZE; 372 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 373 374 skb = alloc_skb(size, GFP_KERNEL); 375 if (skb == NULL) 376 return -ENOMEM; 377 378 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 379 380 skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM); 381 382 __net_timestamp(skb); 383 384 nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_TX); 385 386 return nfc_data_exchange(dev, local->target_idx, skb, 387 nfc_llcp_recv, local); 388 } 389 390 int nfc_llcp_send_connect(struct nfc_llcp_sock *sock) 391 { 392 struct nfc_llcp_local *local; 393 struct sk_buff *skb; 394 const u8 *service_name_tlv = NULL; 395 const u8 *miux_tlv = NULL; 396 const u8 *rw_tlv = NULL; 397 u8 service_name_tlv_length, miux_tlv_length, rw_tlv_length, rw; 398 int err; 399 u16 size = 0; 400 __be16 miux; 401 402 pr_debug("Sending CONNECT\n"); 403 404 local = sock->local; 405 if (local == NULL) 406 return -ENODEV; 407 408 if (sock->service_name != NULL) { 409 service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN, 410 sock->service_name, 411 sock->service_name_len, 412 &service_name_tlv_length); 413 if (!service_name_tlv) { 414 err = -ENOMEM; 415 goto error_tlv; 416 } 417 size += service_name_tlv_length; 418 } 419 420 /* If the socket parameters are not set, use the local ones */ 421 miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ? 422 local->miux : sock->miux; 423 rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw; 424 425 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0, 426 &miux_tlv_length); 427 if (!miux_tlv) { 428 err = -ENOMEM; 429 goto error_tlv; 430 } 431 size += miux_tlv_length; 432 433 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length); 434 if (!rw_tlv) { 435 err = -ENOMEM; 436 goto error_tlv; 437 } 438 size += rw_tlv_length; 439 440 pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len); 441 442 skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size); 443 if (skb == NULL) { 444 err = -ENOMEM; 445 goto error_tlv; 446 } 447 448 llcp_add_tlv(skb, service_name_tlv, service_name_tlv_length); 449 llcp_add_tlv(skb, miux_tlv, miux_tlv_length); 450 llcp_add_tlv(skb, rw_tlv, rw_tlv_length); 451 452 skb_queue_tail(&local->tx_queue, skb); 453 454 err = 0; 455 456 error_tlv: 457 if (err) 458 pr_err("error %d\n", err); 459 460 kfree(service_name_tlv); 461 kfree(miux_tlv); 462 kfree(rw_tlv); 463 464 return err; 465 } 466 467 int nfc_llcp_send_cc(struct nfc_llcp_sock *sock) 468 { 469 struct nfc_llcp_local *local; 470 struct sk_buff *skb; 471 const u8 *miux_tlv = NULL; 472 const u8 *rw_tlv = NULL; 473 u8 miux_tlv_length, rw_tlv_length, rw; 474 int err; 475 u16 size = 0; 476 __be16 miux; 477 478 pr_debug("Sending CC\n"); 479 480 local = sock->local; 481 if (local == NULL) 482 return -ENODEV; 483 484 /* If the socket parameters are not set, use the local ones */ 485 miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ? 486 local->miux : sock->miux; 487 rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw; 488 489 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0, 490 &miux_tlv_length); 491 if (!miux_tlv) { 492 err = -ENOMEM; 493 goto error_tlv; 494 } 495 size += miux_tlv_length; 496 497 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length); 498 if (!rw_tlv) { 499 err = -ENOMEM; 500 goto error_tlv; 501 } 502 size += rw_tlv_length; 503 504 skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size); 505 if (skb == NULL) { 506 err = -ENOMEM; 507 goto error_tlv; 508 } 509 510 llcp_add_tlv(skb, miux_tlv, miux_tlv_length); 511 llcp_add_tlv(skb, rw_tlv, rw_tlv_length); 512 513 skb_queue_tail(&local->tx_queue, skb); 514 515 err = 0; 516 517 error_tlv: 518 if (err) 519 pr_err("error %d\n", err); 520 521 kfree(miux_tlv); 522 kfree(rw_tlv); 523 524 return err; 525 } 526 527 static struct sk_buff *nfc_llcp_allocate_snl(struct nfc_llcp_local *local, 528 size_t tlv_length) 529 { 530 struct sk_buff *skb; 531 struct nfc_dev *dev; 532 u16 size = 0; 533 534 if (local == NULL) 535 return ERR_PTR(-ENODEV); 536 537 dev = local->dev; 538 if (dev == NULL) 539 return ERR_PTR(-ENODEV); 540 541 size += LLCP_HEADER_SIZE; 542 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 543 size += tlv_length; 544 545 skb = alloc_skb(size, GFP_KERNEL); 546 if (skb == NULL) 547 return ERR_PTR(-ENOMEM); 548 549 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 550 551 skb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL); 552 553 return skb; 554 } 555 556 int nfc_llcp_send_snl_sdres(struct nfc_llcp_local *local, 557 struct hlist_head *tlv_list, size_t tlvs_len) 558 { 559 struct nfc_llcp_sdp_tlv *sdp; 560 struct hlist_node *n; 561 struct sk_buff *skb; 562 563 skb = nfc_llcp_allocate_snl(local, tlvs_len); 564 if (IS_ERR(skb)) 565 return PTR_ERR(skb); 566 567 hlist_for_each_entry_safe(sdp, n, tlv_list, node) { 568 skb_put_data(skb, sdp->tlv, sdp->tlv_len); 569 570 hlist_del(&sdp->node); 571 572 nfc_llcp_free_sdp_tlv(sdp); 573 } 574 575 skb_queue_tail(&local->tx_queue, skb); 576 577 return 0; 578 } 579 580 int nfc_llcp_send_snl_sdreq(struct nfc_llcp_local *local, 581 struct hlist_head *tlv_list, size_t tlvs_len) 582 { 583 struct nfc_llcp_sdp_tlv *sdreq; 584 struct hlist_node *n; 585 struct sk_buff *skb; 586 587 skb = nfc_llcp_allocate_snl(local, tlvs_len); 588 if (IS_ERR(skb)) 589 return PTR_ERR(skb); 590 591 mutex_lock(&local->sdreq_lock); 592 593 if (hlist_empty(&local->pending_sdreqs)) 594 mod_timer(&local->sdreq_timer, 595 jiffies + msecs_to_jiffies(3 * local->remote_lto)); 596 597 hlist_for_each_entry_safe(sdreq, n, tlv_list, node) { 598 pr_debug("tid %d for %s\n", sdreq->tid, sdreq->uri); 599 600 skb_put_data(skb, sdreq->tlv, sdreq->tlv_len); 601 602 hlist_del(&sdreq->node); 603 604 hlist_add_head(&sdreq->node, &local->pending_sdreqs); 605 } 606 607 mutex_unlock(&local->sdreq_lock); 608 609 skb_queue_tail(&local->tx_queue, skb); 610 611 return 0; 612 } 613 614 int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason) 615 { 616 struct sk_buff *skb; 617 struct nfc_dev *dev; 618 u16 size = 1; /* Reason code */ 619 620 pr_debug("Sending DM reason 0x%x\n", reason); 621 622 if (local == NULL) 623 return -ENODEV; 624 625 dev = local->dev; 626 if (dev == NULL) 627 return -ENODEV; 628 629 size += LLCP_HEADER_SIZE; 630 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 631 632 skb = alloc_skb(size, GFP_KERNEL); 633 if (skb == NULL) 634 return -ENOMEM; 635 636 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 637 638 skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM); 639 640 skb_put_data(skb, &reason, 1); 641 642 skb_queue_head(&local->tx_queue, skb); 643 644 return 0; 645 } 646 647 int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock, 648 struct msghdr *msg, size_t len) 649 { 650 struct sk_buff *pdu; 651 struct sock *sk = &sock->sk; 652 struct nfc_llcp_local *local; 653 size_t frag_len = 0, remaining_len; 654 u8 *msg_data, *msg_ptr; 655 u16 remote_miu; 656 657 pr_debug("Send I frame len %zd\n", len); 658 659 local = sock->local; 660 if (local == NULL) 661 return -ENODEV; 662 663 /* Remote is ready but has not acknowledged our frames */ 664 if((sock->remote_ready && 665 skb_queue_len(&sock->tx_pending_queue) >= sock->remote_rw && 666 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) { 667 pr_err("Pending queue is full %d frames\n", 668 skb_queue_len(&sock->tx_pending_queue)); 669 return -ENOBUFS; 670 } 671 672 /* Remote is not ready and we've been queueing enough frames */ 673 if ((!sock->remote_ready && 674 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) { 675 pr_err("Tx queue is full %d frames\n", 676 skb_queue_len(&sock->tx_queue)); 677 return -ENOBUFS; 678 } 679 680 msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN); 681 if (msg_data == NULL) 682 return -ENOMEM; 683 684 if (memcpy_from_msg(msg_data, msg, len)) { 685 kfree(msg_data); 686 return -EFAULT; 687 } 688 689 remaining_len = len; 690 msg_ptr = msg_data; 691 692 do { 693 remote_miu = sock->remote_miu > LLCP_MAX_MIU ? 694 LLCP_DEFAULT_MIU : sock->remote_miu; 695 696 frag_len = min_t(size_t, remote_miu, remaining_len); 697 698 pr_debug("Fragment %zd bytes remaining %zd", 699 frag_len, remaining_len); 700 701 pdu = llcp_allocate_pdu(sock, LLCP_PDU_I, 702 frag_len + LLCP_SEQUENCE_SIZE); 703 if (pdu == NULL) { 704 kfree(msg_data); 705 return -ENOMEM; 706 } 707 708 skb_put(pdu, LLCP_SEQUENCE_SIZE); 709 710 if (likely(frag_len > 0)) 711 skb_put_data(pdu, msg_ptr, frag_len); 712 713 skb_queue_tail(&sock->tx_queue, pdu); 714 715 lock_sock(sk); 716 717 nfc_llcp_queue_i_frames(sock); 718 719 release_sock(sk); 720 721 remaining_len -= frag_len; 722 msg_ptr += frag_len; 723 } while (remaining_len > 0); 724 725 kfree(msg_data); 726 727 return len; 728 } 729 730 int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap, 731 struct msghdr *msg, size_t len) 732 { 733 struct sk_buff *pdu; 734 struct nfc_llcp_local *local; 735 size_t frag_len = 0, remaining_len; 736 u8 *msg_ptr, *msg_data; 737 u16 remote_miu; 738 int err; 739 740 pr_debug("Send UI frame len %zd\n", len); 741 742 local = sock->local; 743 if (local == NULL) 744 return -ENODEV; 745 746 msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN); 747 if (msg_data == NULL) 748 return -ENOMEM; 749 750 if (memcpy_from_msg(msg_data, msg, len)) { 751 kfree(msg_data); 752 return -EFAULT; 753 } 754 755 remaining_len = len; 756 msg_ptr = msg_data; 757 758 do { 759 remote_miu = sock->remote_miu > LLCP_MAX_MIU ? 760 local->remote_miu : sock->remote_miu; 761 762 frag_len = min_t(size_t, remote_miu, remaining_len); 763 764 pr_debug("Fragment %zd bytes remaining %zd", 765 frag_len, remaining_len); 766 767 pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, 0, 768 frag_len + LLCP_HEADER_SIZE, &err); 769 if (pdu == NULL) { 770 pr_err("Could not allocate PDU (error=%d)\n", err); 771 len -= remaining_len; 772 if (len == 0) 773 len = err; 774 break; 775 } 776 777 pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI); 778 779 if (likely(frag_len > 0)) 780 skb_put_data(pdu, msg_ptr, frag_len); 781 782 /* No need to check for the peer RW for UI frames */ 783 skb_queue_tail(&local->tx_queue, pdu); 784 785 remaining_len -= frag_len; 786 msg_ptr += frag_len; 787 } while (remaining_len > 0); 788 789 kfree(msg_data); 790 791 return len; 792 } 793 794 int nfc_llcp_send_rr(struct nfc_llcp_sock *sock) 795 { 796 struct sk_buff *skb; 797 struct nfc_llcp_local *local; 798 799 pr_debug("Send rr nr %d\n", sock->recv_n); 800 801 local = sock->local; 802 if (local == NULL) 803 return -ENODEV; 804 805 skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE); 806 if (skb == NULL) 807 return -ENOMEM; 808 809 skb_put(skb, LLCP_SEQUENCE_SIZE); 810 811 skb->data[2] = sock->recv_n; 812 813 skb_queue_head(&local->tx_queue, skb); 814 815 return 0; 816 } 817