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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright (C) 2011  Intel Corporation. All rights reserved.
   4 * Copyright (C) 2014 Marvell International Ltd.
   5 */
   6
   7#define pr_fmt(fmt) "llcp: %s: " fmt, __func__
   8
   9#include <linux/init.h>
  10#include <linux/kernel.h>
  11#include <linux/list.h>
  12#include <linux/nfc.h>
  13
  14#include "nfc.h"
  15#include "llcp.h"
  16
  17static u8 llcp_magic[3] = {0x46, 0x66, 0x6d};
  18
  19static LIST_HEAD(llcp_devices);
  20/* Protects llcp_devices list */
  21static DEFINE_SPINLOCK(llcp_devices_lock);
  22
  23static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb);
  24
  25void nfc_llcp_sock_link(struct llcp_sock_list *l, struct sock *sk)
  26{
  27	write_lock(&l->lock);
  28	sk_add_node(sk, &l->head);
  29	write_unlock(&l->lock);
  30}
  31
  32void nfc_llcp_sock_unlink(struct llcp_sock_list *l, struct sock *sk)
  33{
  34	write_lock(&l->lock);
  35	sk_del_node_init(sk);
  36	write_unlock(&l->lock);
  37}
  38
  39void nfc_llcp_socket_remote_param_init(struct nfc_llcp_sock *sock)
  40{
  41	sock->remote_rw = LLCP_DEFAULT_RW;
  42	sock->remote_miu = LLCP_MAX_MIU + 1;
  43}
  44
  45static void nfc_llcp_socket_purge(struct nfc_llcp_sock *sock)
  46{
  47	struct nfc_llcp_local *local = sock->local;
  48	struct sk_buff *s, *tmp;
  49
  50	skb_queue_purge(&sock->tx_queue);
  51	skb_queue_purge(&sock->tx_pending_queue);
  52
  53	if (local == NULL)
  54		return;
  55
  56	/* Search for local pending SKBs that are related to this socket */
  57	skb_queue_walk_safe(&local->tx_queue, s, tmp) {
  58		if (s->sk != &sock->sk)
  59			continue;
  60
  61		skb_unlink(s, &local->tx_queue);
  62		kfree_skb(s);
  63	}
  64}
  65
  66static void nfc_llcp_socket_release(struct nfc_llcp_local *local, bool device,
  67				    int err)
  68{
  69	struct sock *sk;
  70	struct hlist_node *tmp;
  71	struct nfc_llcp_sock *llcp_sock;
  72
  73	skb_queue_purge(&local->tx_queue);
  74
  75	write_lock(&local->sockets.lock);
  76
  77	sk_for_each_safe(sk, tmp, &local->sockets.head) {
  78		llcp_sock = nfc_llcp_sock(sk);
  79
  80		bh_lock_sock(sk);
  81
  82		nfc_llcp_socket_purge(llcp_sock);
  83
  84		if (sk->sk_state == LLCP_CONNECTED)
  85			nfc_put_device(llcp_sock->dev);
  86
  87		if (sk->sk_state == LLCP_LISTEN) {
  88			struct nfc_llcp_sock *lsk, *n;
  89			struct sock *accept_sk;
  90
  91			list_for_each_entry_safe(lsk, n,
  92						 &llcp_sock->accept_queue,
  93						 accept_queue) {
  94				accept_sk = &lsk->sk;
  95				bh_lock_sock(accept_sk);
  96
  97				nfc_llcp_accept_unlink(accept_sk);
  98
  99				if (err)
 100					accept_sk->sk_err = err;
 101				accept_sk->sk_state = LLCP_CLOSED;
 102				accept_sk->sk_state_change(sk);
 103
 104				bh_unlock_sock(accept_sk);
 105			}
 106		}
 107
 108		if (err)
 109			sk->sk_err = err;
 110		sk->sk_state = LLCP_CLOSED;
 111		sk->sk_state_change(sk);
 112
 113		bh_unlock_sock(sk);
 114
 115		sk_del_node_init(sk);
 116	}
 117
 118	write_unlock(&local->sockets.lock);
 119
 120	/* If we still have a device, we keep the RAW sockets alive */
 121	if (device == true)
 122		return;
 123
 124	write_lock(&local->raw_sockets.lock);
 125
 126	sk_for_each_safe(sk, tmp, &local->raw_sockets.head) {
 127		llcp_sock = nfc_llcp_sock(sk);
 128
 129		bh_lock_sock(sk);
 130
 131		nfc_llcp_socket_purge(llcp_sock);
 132
 133		if (err)
 134			sk->sk_err = err;
 135		sk->sk_state = LLCP_CLOSED;
 136		sk->sk_state_change(sk);
 137
 138		bh_unlock_sock(sk);
 139
 140		sk_del_node_init(sk);
 141	}
 142
 143	write_unlock(&local->raw_sockets.lock);
 144}
 145
 146static struct nfc_llcp_local *nfc_llcp_local_get(struct nfc_llcp_local *local)
 147{
 148	/* Since using nfc_llcp_local may result in usage of nfc_dev, whenever
 149	 * we hold a reference to local, we also need to hold a reference to
 150	 * the device to avoid UAF.
 151	 */
 152	if (!nfc_get_device(local->dev->idx))
 153		return NULL;
 154
 155	kref_get(&local->ref);
 156
 157	return local;
 158}
 159
 160static void local_cleanup(struct nfc_llcp_local *local)
 161{
 162	nfc_llcp_socket_release(local, false, ENXIO);
 163	del_timer_sync(&local->link_timer);
 164	skb_queue_purge(&local->tx_queue);
 165	cancel_work_sync(&local->tx_work);
 166	cancel_work_sync(&local->rx_work);
 167	cancel_work_sync(&local->timeout_work);
 168	kfree_skb(local->rx_pending);
 169	local->rx_pending = NULL;
 170	del_timer_sync(&local->sdreq_timer);
 171	cancel_work_sync(&local->sdreq_timeout_work);
 172	nfc_llcp_free_sdp_tlv_list(&local->pending_sdreqs);
 173}
 174
 175static void local_release(struct kref *ref)
 176{
 177	struct nfc_llcp_local *local;
 178
 179	local = container_of(ref, struct nfc_llcp_local, ref);
 180
 181	local_cleanup(local);
 182	kfree(local);
 183}
 184
 185int nfc_llcp_local_put(struct nfc_llcp_local *local)
 186{
 187	struct nfc_dev *dev;
 188	int ret;
 189
 190	if (local == NULL)
 191		return 0;
 192
 193	dev = local->dev;
 194
 195	ret = kref_put(&local->ref, local_release);
 196	nfc_put_device(dev);
 197
 198	return ret;
 199}
 200
 201static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local,
 202					       u8 ssap, u8 dsap)
 203{
 204	struct sock *sk;
 205	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
 206
 207	pr_debug("ssap dsap %d %d\n", ssap, dsap);
 208
 209	if (ssap == 0 && dsap == 0)
 210		return NULL;
 211
 212	read_lock(&local->sockets.lock);
 213
 214	llcp_sock = NULL;
 215
 216	sk_for_each(sk, &local->sockets.head) {
 217		tmp_sock = nfc_llcp_sock(sk);
 218
 219		if (tmp_sock->ssap == ssap && tmp_sock->dsap == dsap) {
 220			llcp_sock = tmp_sock;
 221			sock_hold(&llcp_sock->sk);
 222			break;
 223		}
 224	}
 225
 226	read_unlock(&local->sockets.lock);
 227
 228	return llcp_sock;
 229}
 230
 231static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock)
 232{
 233	sock_put(&sock->sk);
 234}
 235
 236static void nfc_llcp_timeout_work(struct work_struct *work)
 237{
 238	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
 239						    timeout_work);
 240
 241	nfc_dep_link_down(local->dev);
 242}
 243
 244static void nfc_llcp_symm_timer(struct timer_list *t)
 245{
 246	struct nfc_llcp_local *local = from_timer(local, t, link_timer);
 247
 248	pr_err("SYMM timeout\n");
 249
 250	schedule_work(&local->timeout_work);
 251}
 252
 253static void nfc_llcp_sdreq_timeout_work(struct work_struct *work)
 254{
 255	unsigned long time;
 256	HLIST_HEAD(nl_sdres_list);
 257	struct hlist_node *n;
 258	struct nfc_llcp_sdp_tlv *sdp;
 259	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
 260						    sdreq_timeout_work);
 261
 262	mutex_lock(&local->sdreq_lock);
 263
 264	time = jiffies - msecs_to_jiffies(3 * local->remote_lto);
 265
 266	hlist_for_each_entry_safe(sdp, n, &local->pending_sdreqs, node) {
 267		if (time_after(sdp->time, time))
 268			continue;
 269
 270		sdp->sap = LLCP_SDP_UNBOUND;
 271
 272		hlist_del(&sdp->node);
 273
 274		hlist_add_head(&sdp->node, &nl_sdres_list);
 275	}
 276
 277	if (!hlist_empty(&local->pending_sdreqs))
 278		mod_timer(&local->sdreq_timer,
 279			  jiffies + msecs_to_jiffies(3 * local->remote_lto));
 280
 281	mutex_unlock(&local->sdreq_lock);
 282
 283	if (!hlist_empty(&nl_sdres_list))
 284		nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
 285}
 286
 287static void nfc_llcp_sdreq_timer(struct timer_list *t)
 288{
 289	struct nfc_llcp_local *local = from_timer(local, t, sdreq_timer);
 290
 291	schedule_work(&local->sdreq_timeout_work);
 292}
 293
 294struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev)
 295{
 296	struct nfc_llcp_local *local;
 297	struct nfc_llcp_local *res = NULL;
 298
 299	spin_lock(&llcp_devices_lock);
 300	list_for_each_entry(local, &llcp_devices, list)
 301		if (local->dev == dev) {
 302			res = nfc_llcp_local_get(local);
 303			break;
 304		}
 305	spin_unlock(&llcp_devices_lock);
 306
 307	return res;
 308}
 309
 310static struct nfc_llcp_local *nfc_llcp_remove_local(struct nfc_dev *dev)
 311{
 312	struct nfc_llcp_local *local, *tmp;
 313
 314	spin_lock(&llcp_devices_lock);
 315	list_for_each_entry_safe(local, tmp, &llcp_devices, list)
 316		if (local->dev == dev) {
 317			list_del(&local->list);
 318			spin_unlock(&llcp_devices_lock);
 319			return local;
 320		}
 321	spin_unlock(&llcp_devices_lock);
 322
 323	pr_warn("Shutting down device not found\n");
 324
 325	return NULL;
 326}
 327
 328static char *wks[] = {
 329	NULL,
 330	NULL, /* SDP */
 331	"urn:nfc:sn:ip",
 332	"urn:nfc:sn:obex",
 333	"urn:nfc:sn:snep",
 334};
 335
 336static int nfc_llcp_wks_sap(const char *service_name, size_t service_name_len)
 337{
 338	int sap, num_wks;
 339
 340	pr_debug("%s\n", service_name);
 341
 342	if (service_name == NULL)
 343		return -EINVAL;
 344
 345	num_wks = ARRAY_SIZE(wks);
 346
 347	for (sap = 0; sap < num_wks; sap++) {
 348		if (wks[sap] == NULL)
 349			continue;
 350
 351		if (strncmp(wks[sap], service_name, service_name_len) == 0)
 352			return sap;
 353	}
 354
 355	return -EINVAL;
 356}
 357
 358static
 359struct nfc_llcp_sock *nfc_llcp_sock_from_sn(struct nfc_llcp_local *local,
 360					    const u8 *sn, size_t sn_len,
 361					    bool needref)
 362{
 363	struct sock *sk;
 364	struct nfc_llcp_sock *llcp_sock, *tmp_sock;
 365
 366	pr_debug("sn %zd %p\n", sn_len, sn);
 367
 368	if (sn == NULL || sn_len == 0)
 369		return NULL;
 370
 371	read_lock(&local->sockets.lock);
 372
 373	llcp_sock = NULL;
 374
 375	sk_for_each(sk, &local->sockets.head) {
 376		tmp_sock = nfc_llcp_sock(sk);
 377
 378		pr_debug("llcp sock %p\n", tmp_sock);
 379
 380		if (tmp_sock->sk.sk_type == SOCK_STREAM &&
 381		    tmp_sock->sk.sk_state != LLCP_LISTEN)
 382			continue;
 383
 384		if (tmp_sock->sk.sk_type == SOCK_DGRAM &&
 385		    tmp_sock->sk.sk_state != LLCP_BOUND)
 386			continue;
 387
 388		if (tmp_sock->service_name == NULL ||
 389		    tmp_sock->service_name_len == 0)
 390			continue;
 391
 392		if (tmp_sock->service_name_len != sn_len)
 393			continue;
 394
 395		if (memcmp(sn, tmp_sock->service_name, sn_len) == 0) {
 396			llcp_sock = tmp_sock;
 397			if (needref)
 398				sock_hold(&llcp_sock->sk);
 399			break;
 400		}
 401	}
 402
 403	read_unlock(&local->sockets.lock);
 404
 405	pr_debug("Found llcp sock %p\n", llcp_sock);
 406
 407	return llcp_sock;
 408}
 409
 410u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,
 411			 struct nfc_llcp_sock *sock)
 412{
 413	mutex_lock(&local->sdp_lock);
 414
 415	if (sock->service_name != NULL && sock->service_name_len > 0) {
 416		int ssap = nfc_llcp_wks_sap(sock->service_name,
 417					    sock->service_name_len);
 418
 419		if (ssap > 0) {
 420			pr_debug("WKS %d\n", ssap);
 421
 422			/* This is a WKS, let's check if it's free */
 423			if (test_bit(ssap, &local->local_wks)) {
 424				mutex_unlock(&local->sdp_lock);
 425
 426				return LLCP_SAP_MAX;
 427			}
 428
 429			set_bit(ssap, &local->local_wks);
 430			mutex_unlock(&local->sdp_lock);
 431
 432			return ssap;
 433		}
 434
 435		/*
 436		 * Check if there already is a non WKS socket bound
 437		 * to this service name.
 438		 */
 439		if (nfc_llcp_sock_from_sn(local, sock->service_name,
 440					  sock->service_name_len,
 441					  false) != NULL) {
 442			mutex_unlock(&local->sdp_lock);
 443
 444			return LLCP_SAP_MAX;
 445		}
 446
 447		mutex_unlock(&local->sdp_lock);
 448
 449		return LLCP_SDP_UNBOUND;
 450
 451	} else if (sock->ssap != 0 && sock->ssap < LLCP_WKS_NUM_SAP) {
 452		if (!test_bit(sock->ssap, &local->local_wks)) {
 453			set_bit(sock->ssap, &local->local_wks);
 454			mutex_unlock(&local->sdp_lock);
 455
 456			return sock->ssap;
 457		}
 458	}
 459
 460	mutex_unlock(&local->sdp_lock);
 461
 462	return LLCP_SAP_MAX;
 463}
 464
 465u8 nfc_llcp_get_local_ssap(struct nfc_llcp_local *local)
 466{
 467	u8 local_ssap;
 468
 469	mutex_lock(&local->sdp_lock);
 470
 471	local_ssap = find_first_zero_bit(&local->local_sap, LLCP_LOCAL_NUM_SAP);
 472	if (local_ssap == LLCP_LOCAL_NUM_SAP) {
 473		mutex_unlock(&local->sdp_lock);
 474		return LLCP_SAP_MAX;
 475	}
 476
 477	set_bit(local_ssap, &local->local_sap);
 478
 479	mutex_unlock(&local->sdp_lock);
 480
 481	return local_ssap + LLCP_LOCAL_SAP_OFFSET;
 482}
 483
 484void nfc_llcp_put_ssap(struct nfc_llcp_local *local, u8 ssap)
 485{
 486	u8 local_ssap;
 487	unsigned long *sdp;
 488
 489	if (ssap < LLCP_WKS_NUM_SAP) {
 490		local_ssap = ssap;
 491		sdp = &local->local_wks;
 492	} else if (ssap < LLCP_LOCAL_NUM_SAP) {
 493		atomic_t *client_cnt;
 494
 495		local_ssap = ssap - LLCP_WKS_NUM_SAP;
 496		sdp = &local->local_sdp;
 497		client_cnt = &local->local_sdp_cnt[local_ssap];
 498
 499		pr_debug("%d clients\n", atomic_read(client_cnt));
 500
 501		mutex_lock(&local->sdp_lock);
 502
 503		if (atomic_dec_and_test(client_cnt)) {
 504			struct nfc_llcp_sock *l_sock;
 505
 506			pr_debug("No more clients for SAP %d\n", ssap);
 507
 508			clear_bit(local_ssap, sdp);
 509
 510			/* Find the listening sock and set it back to UNBOUND */
 511			l_sock = nfc_llcp_sock_get(local, ssap, LLCP_SAP_SDP);
 512			if (l_sock) {
 513				l_sock->ssap = LLCP_SDP_UNBOUND;
 514				nfc_llcp_sock_put(l_sock);
 515			}
 516		}
 517
 518		mutex_unlock(&local->sdp_lock);
 519
 520		return;
 521	} else if (ssap < LLCP_MAX_SAP) {
 522		local_ssap = ssap - LLCP_LOCAL_NUM_SAP;
 523		sdp = &local->local_sap;
 524	} else {
 525		return;
 526	}
 527
 528	mutex_lock(&local->sdp_lock);
 529
 530	clear_bit(local_ssap, sdp);
 531
 532	mutex_unlock(&local->sdp_lock);
 533}
 534
 535static u8 nfc_llcp_reserve_sdp_ssap(struct nfc_llcp_local *local)
 536{
 537	u8 ssap;
 538
 539	mutex_lock(&local->sdp_lock);
 540
 541	ssap = find_first_zero_bit(&local->local_sdp, LLCP_SDP_NUM_SAP);
 542	if (ssap == LLCP_SDP_NUM_SAP) {
 543		mutex_unlock(&local->sdp_lock);
 544
 545		return LLCP_SAP_MAX;
 546	}
 547
 548	pr_debug("SDP ssap %d\n", LLCP_WKS_NUM_SAP + ssap);
 549
 550	set_bit(ssap, &local->local_sdp);
 551
 552	mutex_unlock(&local->sdp_lock);
 553
 554	return LLCP_WKS_NUM_SAP + ssap;
 555}
 556
 557static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
 558{
 559	u8 *gb_cur, version, version_length;
 560	u8 lto_length, wks_length, miux_length;
 561	const u8 *version_tlv = NULL, *lto_tlv = NULL,
 562	   *wks_tlv = NULL, *miux_tlv = NULL;
 563	__be16 wks = cpu_to_be16(local->local_wks);
 564	u8 gb_len = 0;
 565	int ret = 0;
 566
 567	version = LLCP_VERSION_11;
 568	version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version,
 569					 1, &version_length);
 570	if (!version_tlv) {
 571		ret = -ENOMEM;
 572		goto out;
 573	}
 574	gb_len += version_length;
 575
 576	lto_tlv = nfc_llcp_build_tlv(LLCP_TLV_LTO, &local->lto, 1, &lto_length);
 577	if (!lto_tlv) {
 578		ret = -ENOMEM;
 579		goto out;
 580	}
 581	gb_len += lto_length;
 582
 583	pr_debug("Local wks 0x%lx\n", local->local_wks);
 584	wks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 *)&wks, 2, &wks_length);
 585	if (!wks_tlv) {
 586		ret = -ENOMEM;
 587		goto out;
 588	}
 589	gb_len += wks_length;
 590
 591	miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&local->miux, 0,
 592				      &miux_length);
 593	if (!miux_tlv) {
 594		ret = -ENOMEM;
 595		goto out;
 596	}
 597	gb_len += miux_length;
 598
 599	gb_len += ARRAY_SIZE(llcp_magic);
 600
 601	if (gb_len > NFC_MAX_GT_LEN) {
 602		ret = -EINVAL;
 603		goto out;
 604	}
 605
 606	gb_cur = local->gb;
 607
 608	memcpy(gb_cur, llcp_magic, ARRAY_SIZE(llcp_magic));
 609	gb_cur += ARRAY_SIZE(llcp_magic);
 610
 611	memcpy(gb_cur, version_tlv, version_length);
 612	gb_cur += version_length;
 613
 614	memcpy(gb_cur, lto_tlv, lto_length);
 615	gb_cur += lto_length;
 616
 617	memcpy(gb_cur, wks_tlv, wks_length);
 618	gb_cur += wks_length;
 619
 620	memcpy(gb_cur, miux_tlv, miux_length);
 621	gb_cur += miux_length;
 622
 623	local->gb_len = gb_len;
 624
 625out:
 626	kfree(version_tlv);
 627	kfree(lto_tlv);
 628	kfree(wks_tlv);
 629	kfree(miux_tlv);
 630
 631	return ret;
 632}
 633
 634u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len)
 635{
 636	struct nfc_llcp_local *local;
 637
 638	local = nfc_llcp_find_local(dev);
 639	if (local == NULL) {
 640		*general_bytes_len = 0;
 641		return NULL;
 642	}
 643
 644	nfc_llcp_build_gb(local);
 645
 646	*general_bytes_len = local->gb_len;
 647
 648	nfc_llcp_local_put(local);
 649
 650	return local->gb;
 651}
 652
 653int nfc_llcp_set_remote_gb(struct nfc_dev *dev, const u8 *gb, u8 gb_len)
 654{
 655	struct nfc_llcp_local *local;
 656	int err;
 657
 658	if (gb_len < 3 || gb_len > NFC_MAX_GT_LEN)
 659		return -EINVAL;
 660
 661	local = nfc_llcp_find_local(dev);
 662	if (local == NULL) {
 663		pr_err("No LLCP device\n");
 664		return -ENODEV;
 665	}
 666
 667	memset(local->remote_gb, 0, NFC_MAX_GT_LEN);
 668	memcpy(local->remote_gb, gb, gb_len);
 669	local->remote_gb_len = gb_len;
 670
 671	if (memcmp(local->remote_gb, llcp_magic, 3)) {
 672		pr_err("MAC does not support LLCP\n");
 673		err = -EINVAL;
 674		goto out;
 675	}
 676
 677	err = nfc_llcp_parse_gb_tlv(local,
 678				     &local->remote_gb[3],
 679				     local->remote_gb_len - 3);
 680out:
 681	nfc_llcp_local_put(local);
 682	return err;
 683}
 684
 685static u8 nfc_llcp_dsap(const struct sk_buff *pdu)
 686{
 687	return (pdu->data[0] & 0xfc) >> 2;
 688}
 689
 690static u8 nfc_llcp_ptype(const struct sk_buff *pdu)
 691{
 692	return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6);
 693}
 694
 695static u8 nfc_llcp_ssap(const struct sk_buff *pdu)
 696{
 697	return pdu->data[1] & 0x3f;
 698}
 699
 700static u8 nfc_llcp_ns(const struct sk_buff *pdu)
 701{
 702	return pdu->data[2] >> 4;
 703}
 704
 705static u8 nfc_llcp_nr(const struct sk_buff *pdu)
 706{
 707	return pdu->data[2] & 0xf;
 708}
 709
 710static void nfc_llcp_set_nrns(struct nfc_llcp_sock *sock, struct sk_buff *pdu)
 711{
 712	pdu->data[2] = (sock->send_n << 4) | (sock->recv_n);
 713	sock->send_n = (sock->send_n + 1) % 16;
 714	sock->recv_ack_n = (sock->recv_n - 1) % 16;
 715}
 716
 717void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local *local,
 718			       struct sk_buff *skb, u8 direction)
 719{
 720	struct sk_buff *skb_copy = NULL, *nskb;
 721	struct sock *sk;
 722	u8 *data;
 723
 724	read_lock(&local->raw_sockets.lock);
 725
 726	sk_for_each(sk, &local->raw_sockets.head) {
 727		if (sk->sk_state != LLCP_BOUND)
 728			continue;
 729
 730		if (skb_copy == NULL) {
 731			skb_copy = __pskb_copy_fclone(skb, NFC_RAW_HEADER_SIZE,
 732						      GFP_ATOMIC, true);
 733
 734			if (skb_copy == NULL)
 735				continue;
 736
 737			data = skb_push(skb_copy, NFC_RAW_HEADER_SIZE);
 738
 739			data[0] = local->dev ? local->dev->idx : 0xFF;
 740			data[1] = direction & 0x01;
 741			data[1] |= (RAW_PAYLOAD_LLCP << 1);
 742		}
 743
 744		nskb = skb_clone(skb_copy, GFP_ATOMIC);
 745		if (!nskb)
 746			continue;
 747
 748		if (sock_queue_rcv_skb(sk, nskb))
 749			kfree_skb(nskb);
 750	}
 751
 752	read_unlock(&local->raw_sockets.lock);
 753
 754	kfree_skb(skb_copy);
 755}
 756
 757static void nfc_llcp_tx_work(struct work_struct *work)
 758{
 759	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
 760						    tx_work);
 761	struct sk_buff *skb;
 762	struct sock *sk;
 763	struct nfc_llcp_sock *llcp_sock;
 764
 765	skb = skb_dequeue(&local->tx_queue);
 766	if (skb != NULL) {
 767		sk = skb->sk;
 768		llcp_sock = nfc_llcp_sock(sk);
 769
 770		if (llcp_sock == NULL && nfc_llcp_ptype(skb) == LLCP_PDU_I) {
 771			kfree_skb(skb);
 772			nfc_llcp_send_symm(local->dev);
 773		} else if (llcp_sock && !llcp_sock->remote_ready) {
 774			skb_queue_head(&local->tx_queue, skb);
 775			nfc_llcp_send_symm(local->dev);
 776		} else {
 777			struct sk_buff *copy_skb = NULL;
 778			u8 ptype = nfc_llcp_ptype(skb);
 779			int ret;
 780
 781			pr_debug("Sending pending skb\n");
 782			print_hex_dump_debug("LLCP Tx: ", DUMP_PREFIX_OFFSET,
 783					     16, 1, skb->data, skb->len, true);
 784
 785			if (ptype == LLCP_PDU_I)
 786				copy_skb = skb_copy(skb, GFP_ATOMIC);
 787
 788			__net_timestamp(skb);
 789
 790			nfc_llcp_send_to_raw_sock(local, skb,
 791						  NFC_DIRECTION_TX);
 792
 793			ret = nfc_data_exchange(local->dev, local->target_idx,
 794						skb, nfc_llcp_recv, local);
 795
 796			if (ret) {
 797				kfree_skb(copy_skb);
 798				goto out;
 799			}
 800
 801			if (ptype == LLCP_PDU_I && copy_skb)
 802				skb_queue_tail(&llcp_sock->tx_pending_queue,
 803					       copy_skb);
 804		}
 805	} else {
 806		nfc_llcp_send_symm(local->dev);
 807	}
 808
 809out:
 810	mod_timer(&local->link_timer,
 811		  jiffies + msecs_to_jiffies(2 * local->remote_lto));
 812}
 813
 814static struct nfc_llcp_sock *nfc_llcp_connecting_sock_get(struct nfc_llcp_local *local,
 815							  u8 ssap)
 816{
 817	struct sock *sk;
 818	struct nfc_llcp_sock *llcp_sock;
 819
 820	read_lock(&local->connecting_sockets.lock);
 821
 822	sk_for_each(sk, &local->connecting_sockets.head) {
 823		llcp_sock = nfc_llcp_sock(sk);
 824
 825		if (llcp_sock->ssap == ssap) {
 826			sock_hold(&llcp_sock->sk);
 827			goto out;
 828		}
 829	}
 830
 831	llcp_sock = NULL;
 832
 833out:
 834	read_unlock(&local->connecting_sockets.lock);
 835
 836	return llcp_sock;
 837}
 838
 839static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local,
 840						  const u8 *sn, size_t sn_len)
 841{
 842	return nfc_llcp_sock_from_sn(local, sn, sn_len, true);
 843}
 844
 845static const u8 *nfc_llcp_connect_sn(const struct sk_buff *skb, size_t *sn_len)
 846{
 847	u8 type, length;
 848	const u8 *tlv = &skb->data[2];
 849	size_t tlv_array_len = skb->len - LLCP_HEADER_SIZE, offset = 0;
 850
 851	while (offset < tlv_array_len) {
 852		type = tlv[0];
 853		length = tlv[1];
 854
 855		pr_debug("type 0x%x length %d\n", type, length);
 856
 857		if (type == LLCP_TLV_SN) {
 858			*sn_len = length;
 859			return &tlv[2];
 860		}
 861
 862		offset += length + 2;
 863		tlv += length + 2;
 864	}
 865
 866	return NULL;
 867}
 868
 869static void nfc_llcp_recv_ui(struct nfc_llcp_local *local,
 870			     struct sk_buff *skb)
 871{
 872	struct nfc_llcp_sock *llcp_sock;
 873	struct nfc_llcp_ui_cb *ui_cb;
 874	u8 dsap, ssap;
 875
 876	dsap = nfc_llcp_dsap(skb);
 877	ssap = nfc_llcp_ssap(skb);
 878
 879	ui_cb = nfc_llcp_ui_skb_cb(skb);
 880	ui_cb->dsap = dsap;
 881	ui_cb->ssap = ssap;
 882
 883	pr_debug("%d %d\n", dsap, ssap);
 884
 885	/* We're looking for a bound socket, not a client one */
 886	llcp_sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
 887	if (llcp_sock == NULL || llcp_sock->sk.sk_type != SOCK_DGRAM)
 888		return;
 889
 890	/* There is no sequence with UI frames */
 891	skb_pull(skb, LLCP_HEADER_SIZE);
 892	if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
 893		/*
 894		 * UI frames will be freed from the socket layer, so we
 895		 * need to keep them alive until someone receives them.
 896		 */
 897		skb_get(skb);
 898	} else {
 899		pr_err("Receive queue is full\n");
 900	}
 901
 902	nfc_llcp_sock_put(llcp_sock);
 903}
 904
 905static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
 906				  const struct sk_buff *skb)
 907{
 908	struct sock *new_sk, *parent;
 909	struct nfc_llcp_sock *sock, *new_sock;
 910	u8 dsap, ssap, reason;
 911
 912	dsap = nfc_llcp_dsap(skb);
 913	ssap = nfc_llcp_ssap(skb);
 914
 915	pr_debug("%d %d\n", dsap, ssap);
 916
 917	if (dsap != LLCP_SAP_SDP) {
 918		sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
 919		if (sock == NULL || sock->sk.sk_state != LLCP_LISTEN) {
 920			reason = LLCP_DM_NOBOUND;
 921			goto fail;
 922		}
 923	} else {
 924		const u8 *sn;
 925		size_t sn_len;
 926
 927		sn = nfc_llcp_connect_sn(skb, &sn_len);
 928		if (sn == NULL) {
 929			reason = LLCP_DM_NOBOUND;
 930			goto fail;
 931		}
 932
 933		pr_debug("Service name length %zu\n", sn_len);
 934
 935		sock = nfc_llcp_sock_get_sn(local, sn, sn_len);
 936		if (sock == NULL) {
 937			reason = LLCP_DM_NOBOUND;
 938			goto fail;
 939		}
 940	}
 941
 942	lock_sock(&sock->sk);
 943
 944	parent = &sock->sk;
 945
 946	if (sk_acceptq_is_full(parent)) {
 947		reason = LLCP_DM_REJ;
 948		release_sock(&sock->sk);
 949		sock_put(&sock->sk);
 950		goto fail;
 951	}
 952
 953	if (sock->ssap == LLCP_SDP_UNBOUND) {
 954		u8 ssap = nfc_llcp_reserve_sdp_ssap(local);
 955
 956		pr_debug("First client, reserving %d\n", ssap);
 957
 958		if (ssap == LLCP_SAP_MAX) {
 959			reason = LLCP_DM_REJ;
 960			release_sock(&sock->sk);
 961			sock_put(&sock->sk);
 962			goto fail;
 963		}
 964
 965		sock->ssap = ssap;
 966	}
 967
 968	new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC, 0);
 969	if (new_sk == NULL) {
 970		reason = LLCP_DM_REJ;
 971		release_sock(&sock->sk);
 972		sock_put(&sock->sk);
 973		goto fail;
 974	}
 975
 976	new_sock = nfc_llcp_sock(new_sk);
 977
 978	new_sock->local = nfc_llcp_local_get(local);
 979	if (!new_sock->local) {
 980		reason = LLCP_DM_REJ;
 981		sock_put(&new_sock->sk);
 982		release_sock(&sock->sk);
 983		sock_put(&sock->sk);
 984		goto fail;
 985	}
 986
 987	new_sock->dev = local->dev;
 988	new_sock->rw = sock->rw;
 989	new_sock->miux = sock->miux;
 990	new_sock->nfc_protocol = sock->nfc_protocol;
 991	new_sock->dsap = ssap;
 992	new_sock->target_idx = local->target_idx;
 993	new_sock->parent = parent;
 994	new_sock->ssap = sock->ssap;
 995	if (sock->ssap < LLCP_LOCAL_NUM_SAP && sock->ssap >= LLCP_WKS_NUM_SAP) {
 996		atomic_t *client_count;
 997
 998		pr_debug("reserved_ssap %d for %p\n", sock->ssap, new_sock);
 999
1000		client_count =
1001			&local->local_sdp_cnt[sock->ssap - LLCP_WKS_NUM_SAP];
1002
1003		atomic_inc(client_count);
1004		new_sock->reserved_ssap = sock->ssap;
1005	}
1006
1007	nfc_llcp_parse_connection_tlv(new_sock, &skb->data[LLCP_HEADER_SIZE],
1008				      skb->len - LLCP_HEADER_SIZE);
1009
1010	pr_debug("new sock %p sk %p\n", new_sock, &new_sock->sk);
1011
1012	nfc_llcp_sock_link(&local->sockets, new_sk);
1013
1014	nfc_llcp_accept_enqueue(&sock->sk, new_sk);
1015
1016	nfc_get_device(local->dev->idx);
1017
1018	new_sk->sk_state = LLCP_CONNECTED;
1019
1020	/* Wake the listening processes */
1021	parent->sk_data_ready(parent);
1022
1023	/* Send CC */
1024	nfc_llcp_send_cc(new_sock);
1025
1026	release_sock(&sock->sk);
1027	sock_put(&sock->sk);
1028
1029	return;
1030
1031fail:
1032	/* Send DM */
1033	nfc_llcp_send_dm(local, dsap, ssap, reason);
1034}
1035
1036int nfc_llcp_queue_i_frames(struct nfc_llcp_sock *sock)
1037{
1038	int nr_frames = 0;
1039	struct nfc_llcp_local *local = sock->local;
1040
1041	pr_debug("Remote ready %d tx queue len %d remote rw %d",
1042		 sock->remote_ready, skb_queue_len(&sock->tx_pending_queue),
1043		 sock->remote_rw);
1044
1045	/* Try to queue some I frames for transmission */
1046	while (sock->remote_ready &&
1047	       skb_queue_len(&sock->tx_pending_queue) < sock->remote_rw) {
1048		struct sk_buff *pdu;
1049
1050		pdu = skb_dequeue(&sock->tx_queue);
1051		if (pdu == NULL)
1052			break;
1053
1054		/* Update N(S)/N(R) */
1055		nfc_llcp_set_nrns(sock, pdu);
1056
1057		skb_queue_tail(&local->tx_queue, pdu);
1058		nr_frames++;
1059	}
1060
1061	return nr_frames;
1062}
1063
1064static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local,
1065			       struct sk_buff *skb)
1066{
1067	struct nfc_llcp_sock *llcp_sock;
1068	struct sock *sk;
1069	u8 dsap, ssap, ptype, ns, nr;
1070
1071	ptype = nfc_llcp_ptype(skb);
1072	dsap = nfc_llcp_dsap(skb);
1073	ssap = nfc_llcp_ssap(skb);
1074	ns = nfc_llcp_ns(skb);
1075	nr = nfc_llcp_nr(skb);
1076
1077	pr_debug("%d %d R %d S %d\n", dsap, ssap, nr, ns);
1078
1079	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1080	if (llcp_sock == NULL) {
1081		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1082		return;
1083	}
1084
1085	sk = &llcp_sock->sk;
1086	lock_sock(sk);
1087	if (sk->sk_state == LLCP_CLOSED) {
1088		release_sock(sk);
1089		nfc_llcp_sock_put(llcp_sock);
1090	}
1091
1092	/* Pass the payload upstream */
1093	if (ptype == LLCP_PDU_I) {
1094		pr_debug("I frame, queueing on %p\n", &llcp_sock->sk);
1095
1096		if (ns == llcp_sock->recv_n)
1097			llcp_sock->recv_n = (llcp_sock->recv_n + 1) % 16;
1098		else
1099			pr_err("Received out of sequence I PDU\n");
1100
1101		skb_pull(skb, LLCP_HEADER_SIZE + LLCP_SEQUENCE_SIZE);
1102		if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
1103			/*
1104			 * I frames will be freed from the socket layer, so we
1105			 * need to keep them alive until someone receives them.
1106			 */
1107			skb_get(skb);
1108		} else {
1109			pr_err("Receive queue is full\n");
1110		}
1111	}
1112
1113	/* Remove skbs from the pending queue */
1114	if (llcp_sock->send_ack_n != nr) {
1115		struct sk_buff *s, *tmp;
1116		u8 n;
1117
1118		llcp_sock->send_ack_n = nr;
1119
1120		/* Remove and free all skbs until ns == nr */
1121		skb_queue_walk_safe(&llcp_sock->tx_pending_queue, s, tmp) {
1122			n = nfc_llcp_ns(s);
1123
1124			skb_unlink(s, &llcp_sock->tx_pending_queue);
1125			kfree_skb(s);
1126
1127			if (n == nr)
1128				break;
1129		}
1130
1131		/* Re-queue the remaining skbs for transmission */
1132		skb_queue_reverse_walk_safe(&llcp_sock->tx_pending_queue,
1133					    s, tmp) {
1134			skb_unlink(s, &llcp_sock->tx_pending_queue);
1135			skb_queue_head(&local->tx_queue, s);
1136		}
1137	}
1138
1139	if (ptype == LLCP_PDU_RR)
1140		llcp_sock->remote_ready = true;
1141	else if (ptype == LLCP_PDU_RNR)
1142		llcp_sock->remote_ready = false;
1143
1144	if (nfc_llcp_queue_i_frames(llcp_sock) == 0 && ptype == LLCP_PDU_I)
1145		nfc_llcp_send_rr(llcp_sock);
1146
1147	release_sock(sk);
1148	nfc_llcp_sock_put(llcp_sock);
1149}
1150
1151static void nfc_llcp_recv_disc(struct nfc_llcp_local *local,
1152			       const struct sk_buff *skb)
1153{
1154	struct nfc_llcp_sock *llcp_sock;
1155	struct sock *sk;
1156	u8 dsap, ssap;
1157
1158	dsap = nfc_llcp_dsap(skb);
1159	ssap = nfc_llcp_ssap(skb);
1160
1161	if ((dsap == 0) && (ssap == 0)) {
1162		pr_debug("Connection termination");
1163		nfc_dep_link_down(local->dev);
1164		return;
1165	}
1166
1167	llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1168	if (llcp_sock == NULL) {
1169		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1170		return;
1171	}
1172
1173	sk = &llcp_sock->sk;
1174	lock_sock(sk);
1175
1176	nfc_llcp_socket_purge(llcp_sock);
1177
1178	if (sk->sk_state == LLCP_CLOSED) {
1179		release_sock(sk);
1180		nfc_llcp_sock_put(llcp_sock);
1181	}
1182
1183	if (sk->sk_state == LLCP_CONNECTED) {
1184		nfc_put_device(local->dev);
1185		sk->sk_state = LLCP_CLOSED;
1186		sk->sk_state_change(sk);
1187	}
1188
1189	nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_DISC);
1190
1191	release_sock(sk);
1192	nfc_llcp_sock_put(llcp_sock);
1193}
1194
1195static void nfc_llcp_recv_cc(struct nfc_llcp_local *local,
1196			     const struct sk_buff *skb)
1197{
1198	struct nfc_llcp_sock *llcp_sock;
1199	struct sock *sk;
1200	u8 dsap, ssap;
1201
1202	dsap = nfc_llcp_dsap(skb);
1203	ssap = nfc_llcp_ssap(skb);
1204
1205	llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1206	if (llcp_sock == NULL) {
1207		pr_err("Invalid CC\n");
1208		nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1209
1210		return;
1211	}
1212
1213	sk = &llcp_sock->sk;
1214
1215	/* Unlink from connecting and link to the client array */
1216	nfc_llcp_sock_unlink(&local->connecting_sockets, sk);
1217	nfc_llcp_sock_link(&local->sockets, sk);
1218	llcp_sock->dsap = ssap;
1219
1220	nfc_llcp_parse_connection_tlv(llcp_sock, &skb->data[LLCP_HEADER_SIZE],
1221				      skb->len - LLCP_HEADER_SIZE);
1222
1223	sk->sk_state = LLCP_CONNECTED;
1224	sk->sk_state_change(sk);
1225
1226	nfc_llcp_sock_put(llcp_sock);
1227}
1228
1229static void nfc_llcp_recv_dm(struct nfc_llcp_local *local,
1230			     const struct sk_buff *skb)
1231{
1232	struct nfc_llcp_sock *llcp_sock;
1233	struct sock *sk;
1234	u8 dsap, ssap, reason;
1235
1236	dsap = nfc_llcp_dsap(skb);
1237	ssap = nfc_llcp_ssap(skb);
1238	reason = skb->data[2];
1239
1240	pr_debug("%d %d reason %d\n", ssap, dsap, reason);
1241
1242	switch (reason) {
1243	case LLCP_DM_NOBOUND:
1244	case LLCP_DM_REJ:
1245		llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1246		break;
1247
1248	default:
1249		llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1250		break;
1251	}
1252
1253	if (llcp_sock == NULL) {
1254		pr_debug("Already closed\n");
1255		return;
1256	}
1257
1258	sk = &llcp_sock->sk;
1259
1260	sk->sk_err = ENXIO;
1261	sk->sk_state = LLCP_CLOSED;
1262	sk->sk_state_change(sk);
1263
1264	nfc_llcp_sock_put(llcp_sock);
1265}
1266
1267static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
1268			      const struct sk_buff *skb)
1269{
1270	struct nfc_llcp_sock *llcp_sock;
1271	u8 dsap, ssap, type, length, tid, sap;
1272	const u8 *tlv;
1273	u16 tlv_len, offset;
1274	const char *service_name;
1275	size_t service_name_len;
1276	struct nfc_llcp_sdp_tlv *sdp;
1277	HLIST_HEAD(llc_sdres_list);
1278	size_t sdres_tlvs_len;
1279	HLIST_HEAD(nl_sdres_list);
1280
1281	dsap = nfc_llcp_dsap(skb);
1282	ssap = nfc_llcp_ssap(skb);
1283
1284	pr_debug("%d %d\n", dsap, ssap);
1285
1286	if (dsap != LLCP_SAP_SDP || ssap != LLCP_SAP_SDP) {
1287		pr_err("Wrong SNL SAP\n");
1288		return;
1289	}
1290
1291	tlv = &skb->data[LLCP_HEADER_SIZE];
1292	tlv_len = skb->len - LLCP_HEADER_SIZE;
1293	offset = 0;
1294	sdres_tlvs_len = 0;
1295
1296	while (offset < tlv_len) {
1297		type = tlv[0];
1298		length = tlv[1];
1299
1300		switch (type) {
1301		case LLCP_TLV_SDREQ:
1302			tid = tlv[2];
1303			service_name = (char *) &tlv[3];
1304			service_name_len = length - 1;
1305
1306			pr_debug("Looking for %.16s\n", service_name);
1307
1308			if (service_name_len == strlen("urn:nfc:sn:sdp") &&
1309			    !strncmp(service_name, "urn:nfc:sn:sdp",
1310				     service_name_len)) {
1311				sap = 1;
1312				goto add_snl;
1313			}
1314
1315			llcp_sock = nfc_llcp_sock_from_sn(local, service_name,
1316							  service_name_len,
1317							  true);
1318			if (!llcp_sock) {
1319				sap = 0;
1320				goto add_snl;
1321			}
1322
1323			/*
1324			 * We found a socket but its ssap has not been reserved
1325			 * yet. We need to assign it for good and send a reply.
1326			 * The ssap will be freed when the socket is closed.
1327			 */
1328			if (llcp_sock->ssap == LLCP_SDP_UNBOUND) {
1329				atomic_t *client_count;
1330
1331				sap = nfc_llcp_reserve_sdp_ssap(local);
1332
1333				pr_debug("Reserving %d\n", sap);
1334
1335				if (sap == LLCP_SAP_MAX) {
1336					sap = 0;
1337					nfc_llcp_sock_put(llcp_sock);
1338					goto add_snl;
1339				}
1340
1341				client_count =
1342					&local->local_sdp_cnt[sap -
1343							      LLCP_WKS_NUM_SAP];
1344
1345				atomic_inc(client_count);
1346
1347				llcp_sock->ssap = sap;
1348				llcp_sock->reserved_ssap = sap;
1349			} else {
1350				sap = llcp_sock->ssap;
1351			}
1352
1353			pr_debug("%p %d\n", llcp_sock, sap);
1354
1355			nfc_llcp_sock_put(llcp_sock);
1356add_snl:
1357			sdp = nfc_llcp_build_sdres_tlv(tid, sap);
1358			if (sdp == NULL)
1359				goto exit;
1360
1361			sdres_tlvs_len += sdp->tlv_len;
1362			hlist_add_head(&sdp->node, &llc_sdres_list);
1363			break;
1364
1365		case LLCP_TLV_SDRES:
1366			mutex_lock(&local->sdreq_lock);
1367
1368			pr_debug("LLCP_TLV_SDRES: searching tid %d\n", tlv[2]);
1369
1370			hlist_for_each_entry(sdp, &local->pending_sdreqs, node) {
1371				if (sdp->tid != tlv[2])
1372					continue;
1373
1374				sdp->sap = tlv[3];
1375
1376				pr_debug("Found: uri=%s, sap=%d\n",
1377					 sdp->uri, sdp->sap);
1378
1379				hlist_del(&sdp->node);
1380
1381				hlist_add_head(&sdp->node, &nl_sdres_list);
1382
1383				break;
1384			}
1385
1386			mutex_unlock(&local->sdreq_lock);
1387			break;
1388
1389		default:
1390			pr_err("Invalid SNL tlv value 0x%x\n", type);
1391			break;
1392		}
1393
1394		offset += length + 2;
1395		tlv += length + 2;
1396	}
1397
1398exit:
1399	if (!hlist_empty(&nl_sdres_list))
1400		nfc_genl_llc_send_sdres(local->dev, &nl_sdres_list);
1401
1402	if (!hlist_empty(&llc_sdres_list))
1403		nfc_llcp_send_snl_sdres(local, &llc_sdres_list, sdres_tlvs_len);
1404}
1405
1406static void nfc_llcp_recv_agf(struct nfc_llcp_local *local, struct sk_buff *skb)
1407{
1408	u8 ptype;
1409	u16 pdu_len;
1410	struct sk_buff *new_skb;
1411
1412	if (skb->len <= LLCP_HEADER_SIZE) {
1413		pr_err("Malformed AGF PDU\n");
1414		return;
1415	}
1416
1417	skb_pull(skb, LLCP_HEADER_SIZE);
1418
1419	while (skb->len > LLCP_AGF_PDU_HEADER_SIZE) {
1420		pdu_len = skb->data[0] << 8 | skb->data[1];
1421
1422		skb_pull(skb, LLCP_AGF_PDU_HEADER_SIZE);
1423
1424		if (pdu_len < LLCP_HEADER_SIZE || pdu_len > skb->len) {
1425			pr_err("Malformed AGF PDU\n");
1426			return;
1427		}
1428
1429		ptype = nfc_llcp_ptype(skb);
1430
1431		if (ptype == LLCP_PDU_SYMM || ptype == LLCP_PDU_AGF)
1432			goto next;
1433
1434		new_skb = nfc_alloc_recv_skb(pdu_len, GFP_KERNEL);
1435		if (new_skb == NULL) {
1436			pr_err("Could not allocate PDU\n");
1437			return;
1438		}
1439
1440		skb_put_data(new_skb, skb->data, pdu_len);
1441
1442		nfc_llcp_rx_skb(local, new_skb);
1443
1444		kfree_skb(new_skb);
1445next:
1446		skb_pull(skb, pdu_len);
1447	}
1448}
1449
1450static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb)
1451{
1452	u8 dsap, ssap, ptype;
1453
1454	ptype = nfc_llcp_ptype(skb);
1455	dsap = nfc_llcp_dsap(skb);
1456	ssap = nfc_llcp_ssap(skb);
1457
1458	pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
1459
1460	if (ptype != LLCP_PDU_SYMM)
1461		print_hex_dump_debug("LLCP Rx: ", DUMP_PREFIX_OFFSET, 16, 1,
1462				     skb->data, skb->len, true);
1463
1464	switch (ptype) {
1465	case LLCP_PDU_SYMM:
1466		pr_debug("SYMM\n");
1467		break;
1468
1469	case LLCP_PDU_UI:
1470		pr_debug("UI\n");
1471		nfc_llcp_recv_ui(local, skb);
1472		break;
1473
1474	case LLCP_PDU_CONNECT:
1475		pr_debug("CONNECT\n");
1476		nfc_llcp_recv_connect(local, skb);
1477		break;
1478
1479	case LLCP_PDU_DISC:
1480		pr_debug("DISC\n");
1481		nfc_llcp_recv_disc(local, skb);
1482		break;
1483
1484	case LLCP_PDU_CC:
1485		pr_debug("CC\n");
1486		nfc_llcp_recv_cc(local, skb);
1487		break;
1488
1489	case LLCP_PDU_DM:
1490		pr_debug("DM\n");
1491		nfc_llcp_recv_dm(local, skb);
1492		break;
1493
1494	case LLCP_PDU_SNL:
1495		pr_debug("SNL\n");
1496		nfc_llcp_recv_snl(local, skb);
1497		break;
1498
1499	case LLCP_PDU_I:
1500	case LLCP_PDU_RR:
1501	case LLCP_PDU_RNR:
1502		pr_debug("I frame\n");
1503		nfc_llcp_recv_hdlc(local, skb);
1504		break;
1505
1506	case LLCP_PDU_AGF:
1507		pr_debug("AGF frame\n");
1508		nfc_llcp_recv_agf(local, skb);
1509		break;
1510	}
1511}
1512
1513static void nfc_llcp_rx_work(struct work_struct *work)
1514{
1515	struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
1516						    rx_work);
1517	struct sk_buff *skb;
1518
1519	skb = local->rx_pending;
1520	if (skb == NULL) {
1521		pr_debug("No pending SKB\n");
1522		return;
1523	}
1524
1525	__net_timestamp(skb);
1526
1527	nfc_llcp_send_to_raw_sock(local, skb, NFC_DIRECTION_RX);
1528
1529	nfc_llcp_rx_skb(local, skb);
1530
1531	schedule_work(&local->tx_work);
1532	kfree_skb(local->rx_pending);
1533	local->rx_pending = NULL;
1534}
1535
1536static void __nfc_llcp_recv(struct nfc_llcp_local *local, struct sk_buff *skb)
1537{
1538	local->rx_pending = skb;
1539	del_timer(&local->link_timer);
1540	schedule_work(&local->rx_work);
1541}
1542
1543void nfc_llcp_recv(void *data, struct sk_buff *skb, int err)
1544{
1545	struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
1546
1547	if (err < 0) {
1548		pr_err("LLCP PDU receive err %d\n", err);
1549		return;
1550	}
1551
1552	__nfc_llcp_recv(local, skb);
1553}
1554
1555int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb)
1556{
1557	struct nfc_llcp_local *local;
1558
1559	local = nfc_llcp_find_local(dev);
1560	if (local == NULL) {
1561		kfree_skb(skb);
1562		return -ENODEV;
1563	}
1564
1565	__nfc_llcp_recv(local, skb);
1566
1567	nfc_llcp_local_put(local);
1568
1569	return 0;
1570}
1571
1572void nfc_llcp_mac_is_down(struct nfc_dev *dev)
1573{
1574	struct nfc_llcp_local *local;
1575
1576	local = nfc_llcp_find_local(dev);
1577	if (local == NULL)
1578		return;
1579
1580	local->remote_miu = LLCP_DEFAULT_MIU;
1581	local->remote_lto = LLCP_DEFAULT_LTO;
1582
1583	/* Close and purge all existing sockets */
1584	nfc_llcp_socket_release(local, true, 0);
1585
1586	nfc_llcp_local_put(local);
1587}
1588
1589void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
1590			u8 comm_mode, u8 rf_mode)
1591{
1592	struct nfc_llcp_local *local;
1593
1594	pr_debug("rf mode %d\n", rf_mode);
1595
1596	local = nfc_llcp_find_local(dev);
1597	if (local == NULL)
1598		return;
1599
1600	local->target_idx = target_idx;
1601	local->comm_mode = comm_mode;
1602	local->rf_mode = rf_mode;
1603
1604	if (rf_mode == NFC_RF_INITIATOR) {
1605		pr_debug("Queueing Tx work\n");
1606
1607		schedule_work(&local->tx_work);
1608	} else {
1609		mod_timer(&local->link_timer,
1610			  jiffies + msecs_to_jiffies(local->remote_lto));
1611	}
1612
1613	nfc_llcp_local_put(local);
1614}
1615
1616int nfc_llcp_register_device(struct nfc_dev *ndev)
1617{
1618	struct nfc_llcp_local *local;
1619
1620	local = kzalloc(sizeof(struct nfc_llcp_local), GFP_KERNEL);
1621	if (local == NULL)
1622		return -ENOMEM;
1623
1624	/* As we are going to initialize local's refcount, we need to get the
1625	 * nfc_dev to avoid UAF, otherwise there is no point in continuing.
1626	 * See nfc_llcp_local_get().
1627	 */
1628	local->dev = nfc_get_device(ndev->idx);
1629	if (!local->dev) {
1630		kfree(local);
1631		return -ENODEV;
1632	}
1633
1634	INIT_LIST_HEAD(&local->list);
1635	kref_init(&local->ref);
1636	mutex_init(&local->sdp_lock);
1637	timer_setup(&local->link_timer, nfc_llcp_symm_timer, 0);
1638
1639	skb_queue_head_init(&local->tx_queue);
1640	INIT_WORK(&local->tx_work, nfc_llcp_tx_work);
1641
1642	local->rx_pending = NULL;
1643	INIT_WORK(&local->rx_work, nfc_llcp_rx_work);
1644
1645	INIT_WORK(&local->timeout_work, nfc_llcp_timeout_work);
1646
1647	rwlock_init(&local->sockets.lock);
1648	rwlock_init(&local->connecting_sockets.lock);
1649	rwlock_init(&local->raw_sockets.lock);
1650
1651	local->lto = 150; /* 1500 ms */
1652	local->rw = LLCP_MAX_RW;
1653	local->miux = cpu_to_be16(LLCP_MAX_MIUX);
1654	local->local_wks = 0x1; /* LLC Link Management */
1655
1656	nfc_llcp_build_gb(local);
1657
1658	local->remote_miu = LLCP_DEFAULT_MIU;
1659	local->remote_lto = LLCP_DEFAULT_LTO;
1660
1661	mutex_init(&local->sdreq_lock);
1662	INIT_HLIST_HEAD(&local->pending_sdreqs);
1663	timer_setup(&local->sdreq_timer, nfc_llcp_sdreq_timer, 0);
1664	INIT_WORK(&local->sdreq_timeout_work, nfc_llcp_sdreq_timeout_work);
1665
1666	spin_lock(&llcp_devices_lock);
1667	list_add(&local->list, &llcp_devices);
1668	spin_unlock(&llcp_devices_lock);
1669
1670	return 0;
1671}
1672
1673void nfc_llcp_unregister_device(struct nfc_dev *dev)
1674{
1675	struct nfc_llcp_local *local = nfc_llcp_remove_local(dev);
1676
1677	if (local == NULL) {
1678		pr_debug("No such device\n");
1679		return;
1680	}
1681
1682	local_cleanup(local);
1683
1684	nfc_llcp_local_put(local);
1685}
1686
1687int __init nfc_llcp_init(void)
1688{
1689	return nfc_llcp_sock_init();
1690}
1691
1692void nfc_llcp_exit(void)
1693{
1694	nfc_llcp_sock_exit();
1695}