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/module.h> 25#include <linux/nfc.h> 26 27#include <net/nfc/nfc.h> 28 29#include "nfc.h" 30#include "llcp.h" 31 32static u8 llcp_tlv_length[LLCP_TLV_MAX] = { 33 0, 34 1, /* VERSION */ 35 2, /* MIUX */ 36 2, /* WKS */ 37 1, /* LTO */ 38 1, /* RW */ 39 0, /* SN */ 40 1, /* OPT */ 41 0, /* SDREQ */ 42 2, /* SDRES */ 43 44}; 45 46static u8 llcp_tlv8(u8 *tlv, u8 type) 47{ 48 if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]]) 49 return 0; 50 51 return tlv[2]; 52} 53 54static u16 llcp_tlv16(u8 *tlv, u8 type) 55{ 56 if (tlv[0] != type || tlv[1] != llcp_tlv_length[tlv[0]]) 57 return 0; 58 59 return be16_to_cpu(*((__be16 *)(tlv + 2))); 60} 61 62 63static u8 llcp_tlv_version(u8 *tlv) 64{ 65 return llcp_tlv8(tlv, LLCP_TLV_VERSION); 66} 67 68static u16 llcp_tlv_miux(u8 *tlv) 69{ 70 return llcp_tlv16(tlv, LLCP_TLV_MIUX) & 0x7ff; 71} 72 73static u16 llcp_tlv_wks(u8 *tlv) 74{ 75 return llcp_tlv16(tlv, LLCP_TLV_WKS); 76} 77 78static u16 llcp_tlv_lto(u8 *tlv) 79{ 80 return llcp_tlv8(tlv, LLCP_TLV_LTO); 81} 82 83static u8 llcp_tlv_opt(u8 *tlv) 84{ 85 return llcp_tlv8(tlv, LLCP_TLV_OPT); 86} 87 88static u8 llcp_tlv_rw(u8 *tlv) 89{ 90 return llcp_tlv8(tlv, LLCP_TLV_RW) & 0xf; 91} 92 93u8 *nfc_llcp_build_tlv(u8 type, u8 *value, u8 value_length, u8 *tlv_length) 94{ 95 u8 *tlv, length; 96 97 pr_debug("type %d\n", type); 98 99 if (type >= LLCP_TLV_MAX) 100 return NULL; 101 102 length = llcp_tlv_length[type]; 103 if (length == 0 && value_length == 0) 104 return NULL; 105 else if (length == 0) 106 length = value_length; 107 108 *tlv_length = 2 + length; 109 tlv = kzalloc(2 + length, GFP_KERNEL); 110 if (tlv == NULL) 111 return tlv; 112 113 tlv[0] = type; 114 tlv[1] = length; 115 memcpy(tlv + 2, value, length); 116 117 return tlv; 118} 119 120struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdres_tlv(u8 tid, u8 sap) 121{ 122 struct nfc_llcp_sdp_tlv *sdres; 123 u8 value[2]; 124 125 sdres = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL); 126 if (sdres == NULL) 127 return NULL; 128 129 value[0] = tid; 130 value[1] = sap; 131 132 sdres->tlv = nfc_llcp_build_tlv(LLCP_TLV_SDRES, value, 2, 133 &sdres->tlv_len); 134 if (sdres->tlv == NULL) { 135 kfree(sdres); 136 return NULL; 137 } 138 139 sdres->tid = tid; 140 sdres->sap = sap; 141 142 INIT_HLIST_NODE(&sdres->node); 143 144 return sdres; 145} 146 147struct nfc_llcp_sdp_tlv *nfc_llcp_build_sdreq_tlv(u8 tid, char *uri, 148 size_t uri_len) 149{ 150 struct nfc_llcp_sdp_tlv *sdreq; 151 152 pr_debug("uri: %s, len: %zu\n", uri, uri_len); 153 154 sdreq = kzalloc(sizeof(struct nfc_llcp_sdp_tlv), GFP_KERNEL); 155 if (sdreq == NULL) 156 return NULL; 157 158 sdreq->tlv_len = uri_len + 3; 159 160 if (uri[uri_len - 1] == 0) 161 sdreq->tlv_len--; 162 163 sdreq->tlv = kzalloc(sdreq->tlv_len + 1, GFP_KERNEL); 164 if (sdreq->tlv == NULL) { 165 kfree(sdreq); 166 return NULL; 167 } 168 169 sdreq->tlv[0] = LLCP_TLV_SDREQ; 170 sdreq->tlv[1] = sdreq->tlv_len - 2; 171 sdreq->tlv[2] = tid; 172 173 sdreq->tid = tid; 174 sdreq->uri = sdreq->tlv + 3; 175 memcpy(sdreq->uri, uri, uri_len); 176 177 sdreq->time = jiffies; 178 179 INIT_HLIST_NODE(&sdreq->node); 180 181 return sdreq; 182} 183 184void nfc_llcp_free_sdp_tlv(struct nfc_llcp_sdp_tlv *sdp) 185{ 186 kfree(sdp->tlv); 187 kfree(sdp); 188} 189 190void nfc_llcp_free_sdp_tlv_list(struct hlist_head *head) 191{ 192 struct nfc_llcp_sdp_tlv *sdp; 193 struct hlist_node *n; 194 195 hlist_for_each_entry_safe(sdp, n, head, node) { 196 hlist_del(&sdp->node); 197 198 nfc_llcp_free_sdp_tlv(sdp); 199 } 200} 201 202int nfc_llcp_parse_gb_tlv(struct nfc_llcp_local *local, 203 u8 *tlv_array, u16 tlv_array_len) 204{ 205 u8 *tlv = tlv_array, type, length, offset = 0; 206 207 pr_debug("TLV array length %d\n", tlv_array_len); 208 209 if (local == NULL) 210 return -ENODEV; 211 212 while (offset < tlv_array_len) { 213 type = tlv[0]; 214 length = tlv[1]; 215 216 pr_debug("type 0x%x length %d\n", type, length); 217 218 switch (type) { 219 case LLCP_TLV_VERSION: 220 local->remote_version = llcp_tlv_version(tlv); 221 break; 222 case LLCP_TLV_MIUX: 223 local->remote_miu = llcp_tlv_miux(tlv) + 128; 224 break; 225 case LLCP_TLV_WKS: 226 local->remote_wks = llcp_tlv_wks(tlv); 227 break; 228 case LLCP_TLV_LTO: 229 local->remote_lto = llcp_tlv_lto(tlv) * 10; 230 break; 231 case LLCP_TLV_OPT: 232 local->remote_opt = llcp_tlv_opt(tlv); 233 break; 234 default: 235 pr_err("Invalid gt tlv value 0x%x\n", type); 236 break; 237 } 238 239 offset += length + 2; 240 tlv += length + 2; 241 } 242 243 pr_debug("version 0x%x miu %d lto %d opt 0x%x wks 0x%x\n", 244 local->remote_version, local->remote_miu, 245 local->remote_lto, local->remote_opt, 246 local->remote_wks); 247 248 return 0; 249} 250 251int nfc_llcp_parse_connection_tlv(struct nfc_llcp_sock *sock, 252 u8 *tlv_array, u16 tlv_array_len) 253{ 254 u8 *tlv = tlv_array, type, length, offset = 0; 255 256 pr_debug("TLV array length %d\n", tlv_array_len); 257 258 if (sock == NULL) 259 return -ENOTCONN; 260 261 while (offset < tlv_array_len) { 262 type = tlv[0]; 263 length = tlv[1]; 264 265 pr_debug("type 0x%x length %d\n", type, length); 266 267 switch (type) { 268 case LLCP_TLV_MIUX: 269 sock->remote_miu = llcp_tlv_miux(tlv) + 128; 270 break; 271 case LLCP_TLV_RW: 272 sock->remote_rw = llcp_tlv_rw(tlv); 273 break; 274 case LLCP_TLV_SN: 275 break; 276 default: 277 pr_err("Invalid gt tlv value 0x%x\n", type); 278 break; 279 } 280 281 offset += length + 2; 282 tlv += length + 2; 283 } 284 285 pr_debug("sock %p rw %d miu %d\n", sock, 286 sock->remote_rw, sock->remote_miu); 287 288 return 0; 289} 290 291static struct sk_buff *llcp_add_header(struct sk_buff *pdu, 292 u8 dsap, u8 ssap, u8 ptype) 293{ 294 u8 header[2]; 295 296 pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap); 297 298 header[0] = (u8)((dsap << 2) | (ptype >> 2)); 299 header[1] = (u8)((ptype << 6) | ssap); 300 301 pr_debug("header 0x%x 0x%x\n", header[0], header[1]); 302 303 memcpy(skb_put(pdu, LLCP_HEADER_SIZE), header, LLCP_HEADER_SIZE); 304 305 return pdu; 306} 307 308static struct sk_buff *llcp_add_tlv(struct sk_buff *pdu, u8 *tlv, 309 u8 tlv_length) 310{ 311 /* XXX Add an skb length check */ 312 313 if (tlv == NULL) 314 return NULL; 315 316 memcpy(skb_put(pdu, tlv_length), tlv, tlv_length); 317 318 return pdu; 319} 320 321static struct sk_buff *llcp_allocate_pdu(struct nfc_llcp_sock *sock, 322 u8 cmd, u16 size) 323{ 324 struct sk_buff *skb; 325 int err; 326 327 if (sock->ssap == 0) 328 return NULL; 329 330 skb = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT, 331 size + LLCP_HEADER_SIZE, &err); 332 if (skb == NULL) { 333 pr_err("Could not allocate PDU\n"); 334 return NULL; 335 } 336 337 skb = llcp_add_header(skb, sock->dsap, sock->ssap, cmd); 338 339 return skb; 340} 341 342int nfc_llcp_disconnect(struct nfc_llcp_sock *sock) 343{ 344 struct sk_buff *skb; 345 struct nfc_dev *dev; 346 struct nfc_llcp_local *local; 347 348 pr_debug("Sending DISC\n"); 349 350 local = sock->local; 351 if (local == NULL) 352 return -ENODEV; 353 354 dev = sock->dev; 355 if (dev == NULL) 356 return -ENODEV; 357 358 skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0); 359 if (skb == NULL) 360 return -ENOMEM; 361 362 skb_queue_tail(&local->tx_queue, skb); 363 364 return 0; 365} 366 367int nfc_llcp_send_symm(struct nfc_dev *dev) 368{ 369 struct sk_buff *skb; 370 struct nfc_llcp_local *local; 371 u16 size = 0; 372 373 pr_debug("Sending SYMM\n"); 374 375 local = nfc_llcp_find_local(dev); 376 if (local == NULL) 377 return -ENODEV; 378 379 size += LLCP_HEADER_SIZE; 380 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 381 382 skb = alloc_skb(size, GFP_KERNEL); 383 if (skb == NULL) 384 return -ENOMEM; 385 386 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 387 388 skb = llcp_add_header(skb, 0, 0, LLCP_PDU_SYMM); 389 390 __net_timestamp(skb); 391 392 nfc_llcp_send_to_raw_sock(local, skb, NFC_LLCP_DIRECTION_TX); 393 394 return nfc_data_exchange(dev, local->target_idx, skb, 395 nfc_llcp_recv, local); 396} 397 398int nfc_llcp_send_connect(struct nfc_llcp_sock *sock) 399{ 400 struct nfc_llcp_local *local; 401 struct sk_buff *skb; 402 u8 *service_name_tlv = NULL, service_name_tlv_length; 403 u8 *miux_tlv = NULL, miux_tlv_length; 404 u8 *rw_tlv = NULL, rw_tlv_length, rw; 405 int err; 406 u16 size = 0, miux; 407 408 pr_debug("Sending CONNECT\n"); 409 410 local = sock->local; 411 if (local == NULL) 412 return -ENODEV; 413 414 if (sock->service_name != NULL) { 415 service_name_tlv = nfc_llcp_build_tlv(LLCP_TLV_SN, 416 sock->service_name, 417 sock->service_name_len, 418 &service_name_tlv_length); 419 size += service_name_tlv_length; 420 } 421 422 /* If the socket parameters are not set, use the local ones */ 423 miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ? 424 local->miux : sock->miux; 425 rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw; 426 427 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0, 428 &miux_tlv_length); 429 size += miux_tlv_length; 430 431 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length); 432 size += rw_tlv_length; 433 434 pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len); 435 436 skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size); 437 if (skb == NULL) { 438 err = -ENOMEM; 439 goto error_tlv; 440 } 441 442 if (service_name_tlv != NULL) 443 skb = llcp_add_tlv(skb, service_name_tlv, 444 service_name_tlv_length); 445 446 skb = llcp_add_tlv(skb, miux_tlv, miux_tlv_length); 447 skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length); 448 449 skb_queue_tail(&local->tx_queue, skb); 450 451 return 0; 452 453error_tlv: 454 pr_err("error %d\n", err); 455 456 kfree(service_name_tlv); 457 kfree(miux_tlv); 458 kfree(rw_tlv); 459 460 return err; 461} 462 463int nfc_llcp_send_cc(struct nfc_llcp_sock *sock) 464{ 465 struct nfc_llcp_local *local; 466 struct sk_buff *skb; 467 u8 *miux_tlv = NULL, miux_tlv_length; 468 u8 *rw_tlv = NULL, rw_tlv_length, rw; 469 int err; 470 u16 size = 0, miux; 471 472 pr_debug("Sending CC\n"); 473 474 local = sock->local; 475 if (local == NULL) 476 return -ENODEV; 477 478 /* If the socket parameters are not set, use the local ones */ 479 miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ? 480 local->miux : sock->miux; 481 rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw; 482 483 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0, 484 &miux_tlv_length); 485 size += miux_tlv_length; 486 487 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length); 488 size += rw_tlv_length; 489 490 skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size); 491 if (skb == NULL) { 492 err = -ENOMEM; 493 goto error_tlv; 494 } 495 496 skb = llcp_add_tlv(skb, miux_tlv, miux_tlv_length); 497 skb = llcp_add_tlv(skb, rw_tlv, rw_tlv_length); 498 499 skb_queue_tail(&local->tx_queue, skb); 500 501 return 0; 502 503error_tlv: 504 pr_err("error %d\n", err); 505 506 kfree(miux_tlv); 507 kfree(rw_tlv); 508 509 return err; 510} 511 512static struct sk_buff *nfc_llcp_allocate_snl(struct nfc_llcp_local *local, 513 size_t tlv_length) 514{ 515 struct sk_buff *skb; 516 struct nfc_dev *dev; 517 u16 size = 0; 518 519 if (local == NULL) 520 return ERR_PTR(-ENODEV); 521 522 dev = local->dev; 523 if (dev == NULL) 524 return ERR_PTR(-ENODEV); 525 526 size += LLCP_HEADER_SIZE; 527 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 528 size += tlv_length; 529 530 skb = alloc_skb(size, GFP_KERNEL); 531 if (skb == NULL) 532 return ERR_PTR(-ENOMEM); 533 534 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 535 536 skb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL); 537 538 return skb; 539} 540 541int nfc_llcp_send_snl_sdres(struct nfc_llcp_local *local, 542 struct hlist_head *tlv_list, size_t tlvs_len) 543{ 544 struct nfc_llcp_sdp_tlv *sdp; 545 struct hlist_node *n; 546 struct sk_buff *skb; 547 548 skb = nfc_llcp_allocate_snl(local, tlvs_len); 549 if (IS_ERR(skb)) 550 return PTR_ERR(skb); 551 552 hlist_for_each_entry_safe(sdp, n, tlv_list, node) { 553 memcpy(skb_put(skb, sdp->tlv_len), sdp->tlv, sdp->tlv_len); 554 555 hlist_del(&sdp->node); 556 557 nfc_llcp_free_sdp_tlv(sdp); 558 } 559 560 skb_queue_tail(&local->tx_queue, skb); 561 562 return 0; 563} 564 565int nfc_llcp_send_snl_sdreq(struct nfc_llcp_local *local, 566 struct hlist_head *tlv_list, size_t tlvs_len) 567{ 568 struct nfc_llcp_sdp_tlv *sdreq; 569 struct hlist_node *n; 570 struct sk_buff *skb; 571 572 skb = nfc_llcp_allocate_snl(local, tlvs_len); 573 if (IS_ERR(skb)) 574 return PTR_ERR(skb); 575 576 mutex_lock(&local->sdreq_lock); 577 578 if (hlist_empty(&local->pending_sdreqs)) 579 mod_timer(&local->sdreq_timer, 580 jiffies + msecs_to_jiffies(3 * local->remote_lto)); 581 582 hlist_for_each_entry_safe(sdreq, n, tlv_list, node) { 583 pr_debug("tid %d for %s\n", sdreq->tid, sdreq->uri); 584 585 memcpy(skb_put(skb, sdreq->tlv_len), sdreq->tlv, 586 sdreq->tlv_len); 587 588 hlist_del(&sdreq->node); 589 590 hlist_add_head(&sdreq->node, &local->pending_sdreqs); 591 } 592 593 mutex_unlock(&local->sdreq_lock); 594 595 skb_queue_tail(&local->tx_queue, skb); 596 597 return 0; 598} 599 600int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason) 601{ 602 struct sk_buff *skb; 603 struct nfc_dev *dev; 604 u16 size = 1; /* Reason code */ 605 606 pr_debug("Sending DM reason 0x%x\n", reason); 607 608 if (local == NULL) 609 return -ENODEV; 610 611 dev = local->dev; 612 if (dev == NULL) 613 return -ENODEV; 614 615 size += LLCP_HEADER_SIZE; 616 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 617 618 skb = alloc_skb(size, GFP_KERNEL); 619 if (skb == NULL) 620 return -ENOMEM; 621 622 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 623 624 skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM); 625 626 memcpy(skb_put(skb, 1), &reason, 1); 627 628 skb_queue_head(&local->tx_queue, skb); 629 630 return 0; 631} 632 633int nfc_llcp_send_disconnect(struct nfc_llcp_sock *sock) 634{ 635 struct sk_buff *skb; 636 struct nfc_llcp_local *local; 637 638 pr_debug("Send DISC\n"); 639 640 local = sock->local; 641 if (local == NULL) 642 return -ENODEV; 643 644 skb = llcp_allocate_pdu(sock, LLCP_PDU_DISC, 0); 645 if (skb == NULL) 646 return -ENOMEM; 647 648 skb_queue_head(&local->tx_queue, skb); 649 650 return 0; 651} 652 653int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock, 654 struct msghdr *msg, size_t len) 655{ 656 struct sk_buff *pdu; 657 struct sock *sk = &sock->sk; 658 struct nfc_llcp_local *local; 659 size_t frag_len = 0, remaining_len; 660 u8 *msg_data, *msg_ptr; 661 u16 remote_miu; 662 663 pr_debug("Send I frame len %zd\n", len); 664 665 local = sock->local; 666 if (local == NULL) 667 return -ENODEV; 668 669 /* Remote is ready but has not acknowledged our frames */ 670 if((sock->remote_ready && 671 skb_queue_len(&sock->tx_pending_queue) >= sock->remote_rw && 672 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) { 673 pr_err("Pending queue is full %d frames\n", 674 skb_queue_len(&sock->tx_pending_queue)); 675 return -ENOBUFS; 676 } 677 678 /* Remote is not ready and we've been queueing enough frames */ 679 if ((!sock->remote_ready && 680 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) { 681 pr_err("Tx queue is full %d frames\n", 682 skb_queue_len(&sock->tx_queue)); 683 return -ENOBUFS; 684 } 685 686 msg_data = kzalloc(len, GFP_KERNEL); 687 if (msg_data == NULL) 688 return -ENOMEM; 689 690 if (memcpy_fromiovec(msg_data, msg->msg_iov, len)) { 691 kfree(msg_data); 692 return -EFAULT; 693 } 694 695 remaining_len = len; 696 msg_ptr = msg_data; 697 698 do { 699 remote_miu = sock->remote_miu > LLCP_MAX_MIU ? 700 local->remote_miu : sock->remote_miu; 701 702 frag_len = min_t(size_t, remote_miu, remaining_len); 703 704 pr_debug("Fragment %zd bytes remaining %zd", 705 frag_len, remaining_len); 706 707 pdu = llcp_allocate_pdu(sock, LLCP_PDU_I, 708 frag_len + LLCP_SEQUENCE_SIZE); 709 if (pdu == NULL) 710 return -ENOMEM; 711 712 skb_put(pdu, LLCP_SEQUENCE_SIZE); 713 714 if (likely(frag_len > 0)) 715 memcpy(skb_put(pdu, frag_len), msg_ptr, frag_len); 716 717 skb_queue_tail(&sock->tx_queue, pdu); 718 719 lock_sock(sk); 720 721 nfc_llcp_queue_i_frames(sock); 722 723 release_sock(sk); 724 725 remaining_len -= frag_len; 726 msg_ptr += frag_len; 727 } while (remaining_len > 0); 728 729 kfree(msg_data); 730 731 return len; 732} 733 734int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap, 735 struct msghdr *msg, size_t len) 736{ 737 struct sk_buff *pdu; 738 struct nfc_llcp_local *local; 739 size_t frag_len = 0, remaining_len; 740 u8 *msg_ptr, *msg_data; 741 u16 remote_miu; 742 int err; 743 744 pr_debug("Send UI frame len %zd\n", len); 745 746 local = sock->local; 747 if (local == NULL) 748 return -ENODEV; 749 750 msg_data = kzalloc(len, GFP_KERNEL); 751 if (msg_data == NULL) 752 return -ENOMEM; 753 754 if (memcpy_fromiovec(msg_data, msg->msg_iov, len)) { 755 kfree(msg_data); 756 return -EFAULT; 757 } 758 759 remaining_len = len; 760 msg_ptr = msg_data; 761 762 do { 763 remote_miu = sock->remote_miu > LLCP_MAX_MIU ? 764 local->remote_miu : sock->remote_miu; 765 766 frag_len = min_t(size_t, remote_miu, remaining_len); 767 768 pr_debug("Fragment %zd bytes remaining %zd", 769 frag_len, remaining_len); 770 771 pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, MSG_DONTWAIT, 772 frag_len + LLCP_HEADER_SIZE, &err); 773 if (pdu == NULL) { 774 pr_err("Could not allocate PDU\n"); 775 continue; 776 } 777 778 pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI); 779 780 if (likely(frag_len > 0)) 781 memcpy(skb_put(pdu, frag_len), msg_ptr, frag_len); 782 783 /* No need to check for the peer RW for UI frames */ 784 skb_queue_tail(&local->tx_queue, pdu); 785 786 remaining_len -= frag_len; 787 msg_ptr += frag_len; 788 } while (remaining_len > 0); 789 790 kfree(msg_data); 791 792 return len; 793} 794 795int nfc_llcp_send_rr(struct nfc_llcp_sock *sock) 796{ 797 struct sk_buff *skb; 798 struct nfc_llcp_local *local; 799 800 pr_debug("Send rr nr %d\n", sock->recv_n); 801 802 local = sock->local; 803 if (local == NULL) 804 return -ENODEV; 805 806 skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE); 807 if (skb == NULL) 808 return -ENOMEM; 809 810 skb_put(skb, LLCP_SEQUENCE_SIZE); 811 812 skb->data[2] = sock->recv_n; 813 814 skb_queue_head(&local->tx_queue, skb); 815 816 return 0; 817} 818