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 if (!service_name_tlv) { 423 err = -ENOMEM; 424 goto error_tlv; 425 } 426 size += service_name_tlv_length; 427 } 428 429 /* If the socket parameters are not set, use the local ones */ 430 miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ? 431 local->miux : sock->miux; 432 rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw; 433 434 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0, 435 &miux_tlv_length); 436 if (!miux_tlv) { 437 err = -ENOMEM; 438 goto error_tlv; 439 } 440 size += miux_tlv_length; 441 442 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length); 443 if (!rw_tlv) { 444 err = -ENOMEM; 445 goto error_tlv; 446 } 447 size += rw_tlv_length; 448 449 pr_debug("SKB size %d SN length %zu\n", size, sock->service_name_len); 450 451 skb = llcp_allocate_pdu(sock, LLCP_PDU_CONNECT, size); 452 if (skb == NULL) { 453 err = -ENOMEM; 454 goto error_tlv; 455 } 456 457 llcp_add_tlv(skb, service_name_tlv, service_name_tlv_length); 458 llcp_add_tlv(skb, miux_tlv, miux_tlv_length); 459 llcp_add_tlv(skb, rw_tlv, rw_tlv_length); 460 461 skb_queue_tail(&local->tx_queue, skb); 462 463 err = 0; 464 465 error_tlv: 466 if (err) 467 pr_err("error %d\n", err); 468 469 kfree(service_name_tlv); 470 kfree(miux_tlv); 471 kfree(rw_tlv); 472 473 return err; 474 } 475 476 int nfc_llcp_send_cc(struct nfc_llcp_sock *sock) 477 { 478 struct nfc_llcp_local *local; 479 struct sk_buff *skb; 480 u8 *miux_tlv = NULL, miux_tlv_length; 481 u8 *rw_tlv = NULL, rw_tlv_length, rw; 482 int err; 483 u16 size = 0; 484 __be16 miux; 485 486 pr_debug("Sending CC\n"); 487 488 local = sock->local; 489 if (local == NULL) 490 return -ENODEV; 491 492 /* If the socket parameters are not set, use the local ones */ 493 miux = be16_to_cpu(sock->miux) > LLCP_MAX_MIUX ? 494 local->miux : sock->miux; 495 rw = sock->rw > LLCP_MAX_RW ? local->rw : sock->rw; 496 497 miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&miux, 0, 498 &miux_tlv_length); 499 if (!miux_tlv) { 500 err = -ENOMEM; 501 goto error_tlv; 502 } 503 size += miux_tlv_length; 504 505 rw_tlv = nfc_llcp_build_tlv(LLCP_TLV_RW, &rw, 0, &rw_tlv_length); 506 if (!rw_tlv) { 507 err = -ENOMEM; 508 goto error_tlv; 509 } 510 size += rw_tlv_length; 511 512 skb = llcp_allocate_pdu(sock, LLCP_PDU_CC, size); 513 if (skb == NULL) { 514 err = -ENOMEM; 515 goto error_tlv; 516 } 517 518 llcp_add_tlv(skb, miux_tlv, miux_tlv_length); 519 llcp_add_tlv(skb, rw_tlv, rw_tlv_length); 520 521 skb_queue_tail(&local->tx_queue, skb); 522 523 err = 0; 524 525 error_tlv: 526 if (err) 527 pr_err("error %d\n", err); 528 529 kfree(miux_tlv); 530 kfree(rw_tlv); 531 532 return err; 533 } 534 535 static struct sk_buff *nfc_llcp_allocate_snl(struct nfc_llcp_local *local, 536 size_t tlv_length) 537 { 538 struct sk_buff *skb; 539 struct nfc_dev *dev; 540 u16 size = 0; 541 542 if (local == NULL) 543 return ERR_PTR(-ENODEV); 544 545 dev = local->dev; 546 if (dev == NULL) 547 return ERR_PTR(-ENODEV); 548 549 size += LLCP_HEADER_SIZE; 550 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 551 size += tlv_length; 552 553 skb = alloc_skb(size, GFP_KERNEL); 554 if (skb == NULL) 555 return ERR_PTR(-ENOMEM); 556 557 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 558 559 skb = llcp_add_header(skb, LLCP_SAP_SDP, LLCP_SAP_SDP, LLCP_PDU_SNL); 560 561 return skb; 562 } 563 564 int nfc_llcp_send_snl_sdres(struct nfc_llcp_local *local, 565 struct hlist_head *tlv_list, size_t tlvs_len) 566 { 567 struct nfc_llcp_sdp_tlv *sdp; 568 struct hlist_node *n; 569 struct sk_buff *skb; 570 571 skb = nfc_llcp_allocate_snl(local, tlvs_len); 572 if (IS_ERR(skb)) 573 return PTR_ERR(skb); 574 575 hlist_for_each_entry_safe(sdp, n, tlv_list, node) { 576 skb_put_data(skb, sdp->tlv, sdp->tlv_len); 577 578 hlist_del(&sdp->node); 579 580 nfc_llcp_free_sdp_tlv(sdp); 581 } 582 583 skb_queue_tail(&local->tx_queue, skb); 584 585 return 0; 586 } 587 588 int nfc_llcp_send_snl_sdreq(struct nfc_llcp_local *local, 589 struct hlist_head *tlv_list, size_t tlvs_len) 590 { 591 struct nfc_llcp_sdp_tlv *sdreq; 592 struct hlist_node *n; 593 struct sk_buff *skb; 594 595 skb = nfc_llcp_allocate_snl(local, tlvs_len); 596 if (IS_ERR(skb)) 597 return PTR_ERR(skb); 598 599 mutex_lock(&local->sdreq_lock); 600 601 if (hlist_empty(&local->pending_sdreqs)) 602 mod_timer(&local->sdreq_timer, 603 jiffies + msecs_to_jiffies(3 * local->remote_lto)); 604 605 hlist_for_each_entry_safe(sdreq, n, tlv_list, node) { 606 pr_debug("tid %d for %s\n", sdreq->tid, sdreq->uri); 607 608 skb_put_data(skb, sdreq->tlv, sdreq->tlv_len); 609 610 hlist_del(&sdreq->node); 611 612 hlist_add_head(&sdreq->node, &local->pending_sdreqs); 613 } 614 615 mutex_unlock(&local->sdreq_lock); 616 617 skb_queue_tail(&local->tx_queue, skb); 618 619 return 0; 620 } 621 622 int nfc_llcp_send_dm(struct nfc_llcp_local *local, u8 ssap, u8 dsap, u8 reason) 623 { 624 struct sk_buff *skb; 625 struct nfc_dev *dev; 626 u16 size = 1; /* Reason code */ 627 628 pr_debug("Sending DM reason 0x%x\n", reason); 629 630 if (local == NULL) 631 return -ENODEV; 632 633 dev = local->dev; 634 if (dev == NULL) 635 return -ENODEV; 636 637 size += LLCP_HEADER_SIZE; 638 size += dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE; 639 640 skb = alloc_skb(size, GFP_KERNEL); 641 if (skb == NULL) 642 return -ENOMEM; 643 644 skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE); 645 646 skb = llcp_add_header(skb, dsap, ssap, LLCP_PDU_DM); 647 648 skb_put_data(skb, &reason, 1); 649 650 skb_queue_head(&local->tx_queue, skb); 651 652 return 0; 653 } 654 655 int nfc_llcp_send_i_frame(struct nfc_llcp_sock *sock, 656 struct msghdr *msg, size_t len) 657 { 658 struct sk_buff *pdu; 659 struct sock *sk = &sock->sk; 660 struct nfc_llcp_local *local; 661 size_t frag_len = 0, remaining_len; 662 u8 *msg_data, *msg_ptr; 663 u16 remote_miu; 664 665 pr_debug("Send I frame len %zd\n", len); 666 667 local = sock->local; 668 if (local == NULL) 669 return -ENODEV; 670 671 /* Remote is ready but has not acknowledged our frames */ 672 if((sock->remote_ready && 673 skb_queue_len(&sock->tx_pending_queue) >= sock->remote_rw && 674 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) { 675 pr_err("Pending queue is full %d frames\n", 676 skb_queue_len(&sock->tx_pending_queue)); 677 return -ENOBUFS; 678 } 679 680 /* Remote is not ready and we've been queueing enough frames */ 681 if ((!sock->remote_ready && 682 skb_queue_len(&sock->tx_queue) >= 2 * sock->remote_rw)) { 683 pr_err("Tx queue is full %d frames\n", 684 skb_queue_len(&sock->tx_queue)); 685 return -ENOBUFS; 686 } 687 688 msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN); 689 if (msg_data == NULL) 690 return -ENOMEM; 691 692 if (memcpy_from_msg(msg_data, msg, len)) { 693 kfree(msg_data); 694 return -EFAULT; 695 } 696 697 remaining_len = len; 698 msg_ptr = msg_data; 699 700 do { 701 remote_miu = sock->remote_miu > LLCP_MAX_MIU ? 702 LLCP_DEFAULT_MIU : sock->remote_miu; 703 704 frag_len = min_t(size_t, remote_miu, remaining_len); 705 706 pr_debug("Fragment %zd bytes remaining %zd", 707 frag_len, remaining_len); 708 709 pdu = llcp_allocate_pdu(sock, LLCP_PDU_I, 710 frag_len + LLCP_SEQUENCE_SIZE); 711 if (pdu == NULL) { 712 kfree(msg_data); 713 return -ENOMEM; 714 } 715 716 skb_put(pdu, LLCP_SEQUENCE_SIZE); 717 718 if (likely(frag_len > 0)) 719 skb_put_data(pdu, msg_ptr, frag_len); 720 721 skb_queue_tail(&sock->tx_queue, pdu); 722 723 lock_sock(sk); 724 725 nfc_llcp_queue_i_frames(sock); 726 727 release_sock(sk); 728 729 remaining_len -= frag_len; 730 msg_ptr += frag_len; 731 } while (remaining_len > 0); 732 733 kfree(msg_data); 734 735 return len; 736 } 737 738 int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap, 739 struct msghdr *msg, size_t len) 740 { 741 struct sk_buff *pdu; 742 struct nfc_llcp_local *local; 743 size_t frag_len = 0, remaining_len; 744 u8 *msg_ptr, *msg_data; 745 u16 remote_miu; 746 int err; 747 748 pr_debug("Send UI frame len %zd\n", len); 749 750 local = sock->local; 751 if (local == NULL) 752 return -ENODEV; 753 754 msg_data = kmalloc(len, GFP_USER | __GFP_NOWARN); 755 if (msg_data == NULL) 756 return -ENOMEM; 757 758 if (memcpy_from_msg(msg_data, msg, len)) { 759 kfree(msg_data); 760 return -EFAULT; 761 } 762 763 remaining_len = len; 764 msg_ptr = msg_data; 765 766 do { 767 remote_miu = sock->remote_miu > LLCP_MAX_MIU ? 768 local->remote_miu : sock->remote_miu; 769 770 frag_len = min_t(size_t, remote_miu, remaining_len); 771 772 pr_debug("Fragment %zd bytes remaining %zd", 773 frag_len, remaining_len); 774 775 pdu = nfc_alloc_send_skb(sock->dev, &sock->sk, 0, 776 frag_len + LLCP_HEADER_SIZE, &err); 777 if (pdu == NULL) { 778 pr_err("Could not allocate PDU (error=%d)\n", err); 779 len -= remaining_len; 780 if (len == 0) 781 len = err; 782 break; 783 } 784 785 pdu = llcp_add_header(pdu, dsap, ssap, LLCP_PDU_UI); 786 787 if (likely(frag_len > 0)) 788 skb_put_data(pdu, msg_ptr, frag_len); 789 790 /* No need to check for the peer RW for UI frames */ 791 skb_queue_tail(&local->tx_queue, pdu); 792 793 remaining_len -= frag_len; 794 msg_ptr += frag_len; 795 } while (remaining_len > 0); 796 797 kfree(msg_data); 798 799 return len; 800 } 801 802 int nfc_llcp_send_rr(struct nfc_llcp_sock *sock) 803 { 804 struct sk_buff *skb; 805 struct nfc_llcp_local *local; 806 807 pr_debug("Send rr nr %d\n", sock->recv_n); 808 809 local = sock->local; 810 if (local == NULL) 811 return -ENODEV; 812 813 skb = llcp_allocate_pdu(sock, LLCP_PDU_RR, LLCP_SEQUENCE_SIZE); 814 if (skb == NULL) 815 return -ENOMEM; 816 817 skb_put(skb, LLCP_SEQUENCE_SIZE); 818 819 skb->data[2] = sock->recv_n; 820 821 skb_queue_head(&local->tx_queue, skb); 822 823 return 0; 824 } 825