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TOMOYO Linux Cross Reference
Linux/net/nfc/llcp_core.c

Version: ~ [ linux-6.11.5 ] ~ [ linux-6.10.14 ] ~ [ linux-6.9.12 ] ~ [ linux-6.8.12 ] ~ [ linux-6.7.12 ] ~ [ linux-6.6.58 ] ~ [ linux-6.5.13 ] ~ [ linux-6.4.16 ] ~ [ linux-6.3.13 ] ~ [ linux-6.2.16 ] ~ [ linux-6.1.114 ] ~ [ linux-6.0.19 ] ~ [ linux-5.19.17 ] ~ [ linux-5.18.19 ] ~ [ linux-5.17.15 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.169 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.228 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.284 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.322 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.336 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.337 ] ~ [ linux-4.4.302 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.9 ] ~ [ policy-sample ] ~
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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 
 17 static u8 llcp_magic[3] = {0x46, 0x66, 0x6d};
 18 
 19 static LIST_HEAD(llcp_devices);
 20 /* Protects llcp_devices list */
 21 static DEFINE_SPINLOCK(llcp_devices_lock);
 22 
 23 static void nfc_llcp_rx_skb(struct nfc_llcp_local *local, struct sk_buff *skb);
 24 
 25 void 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 
 32 void 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 
 39 void 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 
 45 static 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 
 66 static 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 
146 static 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 
160 static 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 
175 static 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 
185 int 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 
201 static 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 
231 static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock)
232 {
233         sock_put(&sock->sk);
234 }
235 
236 static 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 
244 static 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 
253 static 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 
287 static 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 
294 struct 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 
310 static 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 
328 static char *wks[] = {
329         NULL,
330         NULL, /* SDP */
331         "urn:nfc:sn:ip",
332         "urn:nfc:sn:obex",
333         "urn:nfc:sn:snep",
334 };
335 
336 static 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 
358 static
359 struct 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 
410 u8 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 
465 u8 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 
484 void 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 
535 static 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 
557 static 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 
625 out:
626         kfree(version_tlv);
627         kfree(lto_tlv);
628         kfree(wks_tlv);
629         kfree(miux_tlv);
630 
631         return ret;
632 }
633 
634 u8 *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 
653 int 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);
680 out:
681         nfc_llcp_local_put(local);
682         return err;
683 }
684 
685 static u8 nfc_llcp_dsap(const struct sk_buff *pdu)
686 {
687         return (pdu->data[0] & 0xfc) >> 2;
688 }
689 
690 static u8 nfc_llcp_ptype(const struct sk_buff *pdu)
691 {
692         return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6);
693 }
694 
695 static u8 nfc_llcp_ssap(const struct sk_buff *pdu)
696 {
697         return pdu->data[1] & 0x3f;
698 }
699 
700 static u8 nfc_llcp_ns(const struct sk_buff *pdu)
701 {
702         return pdu->data[2] >> 4;
703 }
704 
705 static u8 nfc_llcp_nr(const struct sk_buff *pdu)
706 {
707         return pdu->data[2] & 0xf;
708 }
709 
710 static 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 
717 void 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 
757 static 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 
809 out:
810         mod_timer(&local->link_timer,
811                   jiffies + msecs_to_jiffies(2 * local->remote_lto));
812 }
813 
814 static 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 
833 out:
834         read_unlock(&local->connecting_sockets.lock);
835 
836         return llcp_sock;
837 }
838 
839 static 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 
845 static 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 
869 static 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 
905 static 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 
1031 fail:
1032         /* Send DM */
1033         nfc_llcp_send_dm(local, dsap, ssap, reason);
1034 }
1035 
1036 int 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 
1064 static 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 
1151 static 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 
1195 static 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 
1229 static 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 
1267 static 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);
1356 add_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 
1398 exit:
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 
1406 static 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);
1445 next:
1446                 skb_pull(skb, pdu_len);
1447         }
1448 }
1449 
1450 static 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 
1513 static 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 
1536 static 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 
1543 void 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 
1555 int 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 
1572 void 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 
1589 void 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 
1616 int 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 
1673 void 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 
1687 int __init nfc_llcp_init(void)
1688 {
1689         return nfc_llcp_sock_init();
1690 }
1691 
1692 void nfc_llcp_exit(void)
1693 {
1694         nfc_llcp_sock_exit();
1695 }
1696 

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