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1 /*
2  * Copyright (C) 2011  Intel Corporation. All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the
16  * Free Software Foundation, Inc.,
17  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18  */
19
20 #define pr_fmt(fmt) "llcp: %s: " fmt, __func__
21
22 #include <linux/init.h>
23 #include <linux/kernel.h>
24 #include <linux/list.h>
25 #include <linux/nfc.h>
26
27 #include "../nfc.h"
28 #include "llcp.h"
29
30 static u8 llcp_magic[3] = {0x46, 0x66, 0x6d};
31
32 static struct list_head llcp_devices;
33
34 void nfc_llcp_sock_link(struct llcp_sock_list *l, struct sock *sk)
35 {
36         write_lock(&l->lock);
37         sk_add_node(sk, &l->head);
38         write_unlock(&l->lock);
39 }
40
41 void nfc_llcp_sock_unlink(struct llcp_sock_list *l, struct sock *sk)
42 {
43         write_lock(&l->lock);
44         sk_del_node_init(sk);
45         write_unlock(&l->lock);
46 }
47
48 static void nfc_llcp_socket_purge(struct nfc_llcp_sock *sock)
49 {
50         struct nfc_llcp_local *local = sock->local;
51         struct sk_buff *s, *tmp;
52
53         pr_debug("%p\n", &sock->sk);
54
55         skb_queue_purge(&sock->tx_queue);
56         skb_queue_purge(&sock->tx_pending_queue);
57
58         if (local == NULL)
59                 return;
60
61         /* Search for local pending SKBs that are related to this socket */
62         skb_queue_walk_safe(&local->tx_queue, s, tmp) {
63                 if (s->sk != &sock->sk)
64                         continue;
65
66                 skb_unlink(s, &local->tx_queue);
67                 kfree_skb(s);
68         }
69 }
70
71 static void nfc_llcp_socket_release(struct nfc_llcp_local *local, bool listen)
72 {
73         struct sock *sk;
74         struct hlist_node *tmp;
75         struct nfc_llcp_sock *llcp_sock;
76
77         skb_queue_purge(&local->tx_queue);
78
79         write_lock(&local->sockets.lock);
80
81         sk_for_each_safe(sk, tmp, &local->sockets.head) {
82                 llcp_sock = nfc_llcp_sock(sk);
83
84                 bh_lock_sock(sk);
85
86                 nfc_llcp_socket_purge(llcp_sock);
87
88                 if (sk->sk_state == LLCP_CONNECTED)
89                         nfc_put_device(llcp_sock->dev);
90
91                 if (sk->sk_state == LLCP_LISTEN) {
92                         struct nfc_llcp_sock *lsk, *n;
93                         struct sock *accept_sk;
94
95                         list_for_each_entry_safe(lsk, n,
96                                                  &llcp_sock->accept_queue,
97                                                  accept_queue) {
98                                 accept_sk = &lsk->sk;
99                                 bh_lock_sock(accept_sk);
100
101                                 nfc_llcp_accept_unlink(accept_sk);
102
103                                 accept_sk->sk_state = LLCP_CLOSED;
104
105                                 bh_unlock_sock(accept_sk);
106
107                                 sock_orphan(accept_sk);
108                         }
109
110                         if (listen == true) {
111                                 bh_unlock_sock(sk);
112                                 continue;
113                         }
114                 }
115
116                 /*
117                  * If we have a connection less socket bound, we keep it alive
118                  * if the device is still present.
119                  */
120                 if (sk->sk_state == LLCP_BOUND && sk->sk_type == SOCK_DGRAM &&
121                     listen == true) {
122                         bh_unlock_sock(sk);
123                         continue;
124                 }
125
126                 sk->sk_state = LLCP_CLOSED;
127
128                 bh_unlock_sock(sk);
129
130                 sock_orphan(sk);
131
132                 sk_del_node_init(sk);
133         }
134
135         write_unlock(&local->sockets.lock);
136 }
137
138 struct nfc_llcp_local *nfc_llcp_local_get(struct nfc_llcp_local *local)
139 {
140         kref_get(&local->ref);
141
142         return local;
143 }
144
145 static void local_release(struct kref *ref)
146 {
147         struct nfc_llcp_local *local;
148
149         local = container_of(ref, struct nfc_llcp_local, ref);
150
151         list_del(&local->list);
152         nfc_llcp_socket_release(local, false);
153         del_timer_sync(&local->link_timer);
154         skb_queue_purge(&local->tx_queue);
155         cancel_work_sync(&local->tx_work);
156         cancel_work_sync(&local->rx_work);
157         cancel_work_sync(&local->timeout_work);
158         kfree_skb(local->rx_pending);
159         kfree(local);
160 }
161
162 int nfc_llcp_local_put(struct nfc_llcp_local *local)
163 {
164         if (local == NULL)
165                 return 0;
166
167         return kref_put(&local->ref, local_release);
168 }
169
170 static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local,
171                                                u8 ssap, u8 dsap)
172 {
173         struct sock *sk;
174         struct nfc_llcp_sock *llcp_sock, *tmp_sock;
175
176         pr_debug("ssap dsap %d %d\n", ssap, dsap);
177
178         if (ssap == 0 && dsap == 0)
179                 return NULL;
180
181         read_lock(&local->sockets.lock);
182
183         llcp_sock = NULL;
184
185         sk_for_each(sk, &local->sockets.head) {
186                 tmp_sock = nfc_llcp_sock(sk);
187
188                 if (tmp_sock->ssap == ssap && tmp_sock->dsap == dsap) {
189                         llcp_sock = tmp_sock;
190                         break;
191                 }
192         }
193
194         read_unlock(&local->sockets.lock);
195
196         if (llcp_sock == NULL)
197                 return NULL;
198
199         sock_hold(&llcp_sock->sk);
200
201         return llcp_sock;
202 }
203
204 static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock)
205 {
206         sock_put(&sock->sk);
207 }
208
209 static void nfc_llcp_timeout_work(struct work_struct *work)
210 {
211         struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
212                                                     timeout_work);
213
214         nfc_dep_link_down(local->dev);
215 }
216
217 static void nfc_llcp_symm_timer(unsigned long data)
218 {
219         struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
220
221         pr_err("SYMM timeout\n");
222
223         schedule_work(&local->timeout_work);
224 }
225
226 struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev)
227 {
228         struct nfc_llcp_local *local, *n;
229
230         list_for_each_entry_safe(local, n, &llcp_devices, list)
231                 if (local->dev == dev)
232                         return local;
233
234         pr_debug("No device found\n");
235
236         return NULL;
237 }
238
239 static char *wks[] = {
240         NULL,
241         NULL, /* SDP */
242         "urn:nfc:sn:ip",
243         "urn:nfc:sn:obex",
244         "urn:nfc:sn:snep",
245 };
246
247 static int nfc_llcp_wks_sap(char *service_name, size_t service_name_len)
248 {
249         int sap, num_wks;
250
251         pr_debug("%s\n", service_name);
252
253         if (service_name == NULL)
254                 return -EINVAL;
255
256         num_wks = ARRAY_SIZE(wks);
257
258         for (sap = 0; sap < num_wks; sap++) {
259                 if (wks[sap] == NULL)
260                         continue;
261
262                 if (strncmp(wks[sap], service_name, service_name_len) == 0)
263                         return sap;
264         }
265
266         return -EINVAL;
267 }
268
269 static
270 struct nfc_llcp_sock *nfc_llcp_sock_from_sn(struct nfc_llcp_local *local,
271                                             u8 *sn, size_t sn_len)
272 {
273         struct sock *sk;
274         struct nfc_llcp_sock *llcp_sock, *tmp_sock;
275
276         pr_debug("sn %zd %p\n", sn_len, sn);
277
278         if (sn == NULL || sn_len == 0)
279                 return NULL;
280
281         read_lock(&local->sockets.lock);
282
283         llcp_sock = NULL;
284
285         sk_for_each(sk, &local->sockets.head) {
286                 tmp_sock = nfc_llcp_sock(sk);
287
288                 pr_debug("llcp sock %p\n", tmp_sock);
289
290                 if (tmp_sock->sk.sk_type == SOCK_STREAM &&
291                     tmp_sock->sk.sk_state != LLCP_LISTEN)
292                         continue;
293
294                 if (tmp_sock->sk.sk_type == SOCK_DGRAM &&
295                     tmp_sock->sk.sk_state != LLCP_BOUND)
296                         continue;
297
298                 if (tmp_sock->service_name == NULL ||
299                     tmp_sock->service_name_len == 0)
300                         continue;
301
302                 if (tmp_sock->service_name_len != sn_len)
303                         continue;
304
305                 if (memcmp(sn, tmp_sock->service_name, sn_len) == 0) {
306                         llcp_sock = tmp_sock;
307                         break;
308                 }
309         }
310
311         read_unlock(&local->sockets.lock);
312
313         pr_debug("Found llcp sock %p\n", llcp_sock);
314
315         return llcp_sock;
316 }
317
318 u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,
319                          struct nfc_llcp_sock *sock)
320 {
321         mutex_lock(&local->sdp_lock);
322
323         if (sock->service_name != NULL && sock->service_name_len > 0) {
324                 int ssap = nfc_llcp_wks_sap(sock->service_name,
325                                             sock->service_name_len);
326
327                 if (ssap > 0) {
328                         pr_debug("WKS %d\n", ssap);
329
330                         /* This is a WKS, let's check if it's free */
331                         if (local->local_wks & BIT(ssap)) {
332                                 mutex_unlock(&local->sdp_lock);
333
334                                 return LLCP_SAP_MAX;
335                         }
336
337                         set_bit(ssap, &local->local_wks);
338                         mutex_unlock(&local->sdp_lock);
339
340                         return ssap;
341                 }
342
343                 /*
344                  * Check if there already is a non WKS socket bound
345                  * to this service name.
346                  */
347                 if (nfc_llcp_sock_from_sn(local, sock->service_name,
348                                           sock->service_name_len) != NULL) {
349                         mutex_unlock(&local->sdp_lock);
350
351                         return LLCP_SAP_MAX;
352                 }
353
354                 mutex_unlock(&local->sdp_lock);
355
356                 return LLCP_SDP_UNBOUND;
357
358         } else if (sock->ssap != 0 && sock->ssap < LLCP_WKS_NUM_SAP) {
359                 if (!test_bit(sock->ssap, &local->local_wks)) {
360                         set_bit(sock->ssap, &local->local_wks);
361                         mutex_unlock(&local->sdp_lock);
362
363                         return sock->ssap;
364                 }
365         }
366
367         mutex_unlock(&local->sdp_lock);
368
369         return LLCP_SAP_MAX;
370 }
371
372 u8 nfc_llcp_get_local_ssap(struct nfc_llcp_local *local)
373 {
374         u8 local_ssap;
375
376         mutex_lock(&local->sdp_lock);
377
378         local_ssap = find_first_zero_bit(&local->local_sap, LLCP_LOCAL_NUM_SAP);
379         if (local_ssap == LLCP_LOCAL_NUM_SAP) {
380                 mutex_unlock(&local->sdp_lock);
381                 return LLCP_SAP_MAX;
382         }
383
384         set_bit(local_ssap, &local->local_sap);
385
386         mutex_unlock(&local->sdp_lock);
387
388         return local_ssap + LLCP_LOCAL_SAP_OFFSET;
389 }
390
391 void nfc_llcp_put_ssap(struct nfc_llcp_local *local, u8 ssap)
392 {
393         u8 local_ssap;
394         unsigned long *sdp;
395
396         if (ssap < LLCP_WKS_NUM_SAP) {
397                 local_ssap = ssap;
398                 sdp = &local->local_wks;
399         } else if (ssap < LLCP_LOCAL_NUM_SAP) {
400                 atomic_t *client_cnt;
401
402                 local_ssap = ssap - LLCP_WKS_NUM_SAP;
403                 sdp = &local->local_sdp;
404                 client_cnt = &local->local_sdp_cnt[local_ssap];
405
406                 pr_debug("%d clients\n", atomic_read(client_cnt));
407
408                 mutex_lock(&local->sdp_lock);
409
410                 if (atomic_dec_and_test(client_cnt)) {
411                         struct nfc_llcp_sock *l_sock;
412
413                         pr_debug("No more clients for SAP %d\n", ssap);
414
415                         clear_bit(local_ssap, sdp);
416
417                         /* Find the listening sock and set it back to UNBOUND */
418                         l_sock = nfc_llcp_sock_get(local, ssap, LLCP_SAP_SDP);
419                         if (l_sock) {
420                                 l_sock->ssap = LLCP_SDP_UNBOUND;
421                                 nfc_llcp_sock_put(l_sock);
422                         }
423                 }
424
425                 mutex_unlock(&local->sdp_lock);
426
427                 return;
428         } else if (ssap < LLCP_MAX_SAP) {
429                 local_ssap = ssap - LLCP_LOCAL_NUM_SAP;
430                 sdp = &local->local_sap;
431         } else {
432                 return;
433         }
434
435         mutex_lock(&local->sdp_lock);
436
437         clear_bit(local_ssap, sdp);
438
439         mutex_unlock(&local->sdp_lock);
440 }
441
442 static u8 nfc_llcp_reserve_sdp_ssap(struct nfc_llcp_local *local)
443 {
444         u8 ssap;
445
446         mutex_lock(&local->sdp_lock);
447
448         ssap = find_first_zero_bit(&local->local_sdp, LLCP_SDP_NUM_SAP);
449         if (ssap == LLCP_SDP_NUM_SAP) {
450                 mutex_unlock(&local->sdp_lock);
451
452                 return LLCP_SAP_MAX;
453         }
454
455         pr_debug("SDP ssap %d\n", LLCP_WKS_NUM_SAP + ssap);
456
457         set_bit(ssap, &local->local_sdp);
458
459         mutex_unlock(&local->sdp_lock);
460
461         return LLCP_WKS_NUM_SAP + ssap;
462 }
463
464 static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
465 {
466         u8 *gb_cur, *version_tlv, version, version_length;
467         u8 *lto_tlv, lto_length;
468         u8 *wks_tlv, wks_length;
469         u8 *miux_tlv, miux_length;
470         u8 gb_len = 0;
471         int ret = 0;
472
473         version = LLCP_VERSION_11;
474         version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version,
475                                          1, &version_length);
476         gb_len += version_length;
477
478         lto_tlv = nfc_llcp_build_tlv(LLCP_TLV_LTO, &local->lto, 1, &lto_length);
479         gb_len += lto_length;
480
481         pr_debug("Local wks 0x%lx\n", local->local_wks);
482         wks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 *)&local->local_wks, 2,
483                                      &wks_length);
484         gb_len += wks_length;
485
486         miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&local->miux, 0,
487                                       &miux_length);
488         gb_len += miux_length;
489
490         gb_len += ARRAY_SIZE(llcp_magic);
491
492         if (gb_len > NFC_MAX_GT_LEN) {
493                 ret = -EINVAL;
494                 goto out;
495         }
496
497         gb_cur = local->gb;
498
499         memcpy(gb_cur, llcp_magic, ARRAY_SIZE(llcp_magic));
500         gb_cur += ARRAY_SIZE(llcp_magic);
501
502         memcpy(gb_cur, version_tlv, version_length);
503         gb_cur += version_length;
504
505         memcpy(gb_cur, lto_tlv, lto_length);
506         gb_cur += lto_length;
507
508         memcpy(gb_cur, wks_tlv, wks_length);
509         gb_cur += wks_length;
510
511         memcpy(gb_cur, miux_tlv, miux_length);
512         gb_cur += miux_length;
513
514         local->gb_len = gb_len;
515
516 out:
517         kfree(version_tlv);
518         kfree(lto_tlv);
519         kfree(wks_tlv);
520         kfree(miux_tlv);
521
522         return ret;
523 }
524
525 u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len)
526 {
527         struct nfc_llcp_local *local;
528
529         local = nfc_llcp_find_local(dev);
530         if (local == NULL) {
531                 *general_bytes_len = 0;
532                 return NULL;
533         }
534
535         nfc_llcp_build_gb(local);
536
537         *general_bytes_len = local->gb_len;
538
539         return local->gb;
540 }
541
542 int nfc_llcp_set_remote_gb(struct nfc_dev *dev, u8 *gb, u8 gb_len)
543 {
544         struct nfc_llcp_local *local = nfc_llcp_find_local(dev);
545
546         if (local == NULL) {
547                 pr_err("No LLCP device\n");
548                 return -ENODEV;
549         }
550         if (gb_len < 3)
551                 return -EINVAL;
552
553         memset(local->remote_gb, 0, NFC_MAX_GT_LEN);
554         memcpy(local->remote_gb, gb, gb_len);
555         local->remote_gb_len = gb_len;
556
557         if (memcmp(local->remote_gb, llcp_magic, 3)) {
558                 pr_err("MAC does not support LLCP\n");
559                 return -EINVAL;
560         }
561
562         return nfc_llcp_parse_gb_tlv(local,
563                                      &local->remote_gb[3],
564                                      local->remote_gb_len - 3);
565 }
566
567 static u8 nfc_llcp_dsap(struct sk_buff *pdu)
568 {
569         return (pdu->data[0] & 0xfc) >> 2;
570 }
571
572 static u8 nfc_llcp_ptype(struct sk_buff *pdu)
573 {
574         return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6);
575 }
576
577 static u8 nfc_llcp_ssap(struct sk_buff *pdu)
578 {
579         return pdu->data[1] & 0x3f;
580 }
581
582 static u8 nfc_llcp_ns(struct sk_buff *pdu)
583 {
584         return pdu->data[2] >> 4;
585 }
586
587 static u8 nfc_llcp_nr(struct sk_buff *pdu)
588 {
589         return pdu->data[2] & 0xf;
590 }
591
592 static void nfc_llcp_set_nrns(struct nfc_llcp_sock *sock, struct sk_buff *pdu)
593 {
594         pdu->data[2] = (sock->send_n << 4) | (sock->recv_n);
595         sock->send_n = (sock->send_n + 1) % 16;
596         sock->recv_ack_n = (sock->recv_n - 1) % 16;
597 }
598
599 void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local *local,
600                                struct sk_buff *skb, u8 direction)
601 {
602         struct sk_buff *skb_copy = NULL, *nskb;
603         struct sock *sk;
604         u8 *data;
605
606         read_lock(&local->raw_sockets.lock);
607
608         sk_for_each(sk, &local->raw_sockets.head) {
609                 if (sk->sk_state != LLCP_BOUND)
610                         continue;
611
612                 if (skb_copy == NULL) {
613                         skb_copy = __pskb_copy(skb, NFC_LLCP_RAW_HEADER_SIZE,
614                                                GFP_ATOMIC);
615
616                         if (skb_copy == NULL)
617                                 continue;
618
619                         data = skb_push(skb_copy, NFC_LLCP_RAW_HEADER_SIZE);
620
621                         data[0] = local->dev ? local->dev->idx : 0xFF;
622                         data[1] = direction;
623                 }
624
625                 nskb = skb_clone(skb_copy, GFP_ATOMIC);
626                 if (!nskb)
627                         continue;
628
629                 if (sock_queue_rcv_skb(sk, nskb))
630                         kfree_skb(nskb);
631         }
632
633         read_unlock(&local->raw_sockets.lock);
634
635         kfree_skb(skb_copy);
636 }
637
638 static void nfc_llcp_tx_work(struct work_struct *work)
639 {
640         struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
641                                                     tx_work);
642         struct sk_buff *skb;
643         struct sock *sk;
644         struct nfc_llcp_sock *llcp_sock;
645
646         skb = skb_dequeue(&local->tx_queue);
647         if (skb != NULL) {
648                 sk = skb->sk;
649                 llcp_sock = nfc_llcp_sock(sk);
650
651                 if (llcp_sock == NULL && nfc_llcp_ptype(skb) == LLCP_PDU_I) {
652                         nfc_llcp_send_symm(local->dev);
653                 } else {
654                         struct sk_buff *copy_skb = NULL;
655                         u8 ptype = nfc_llcp_ptype(skb);
656                         int ret;
657
658                         pr_debug("Sending pending skb\n");
659                         print_hex_dump(KERN_DEBUG, "LLCP Tx: ",
660                                        DUMP_PREFIX_OFFSET, 16, 1,
661                                        skb->data, skb->len, true);
662
663                         if (ptype == LLCP_PDU_I)
664                                 copy_skb = skb_copy(skb, GFP_ATOMIC);
665
666                         __net_timestamp(skb);
667
668                         nfc_llcp_send_to_raw_sock(local, skb,
669                                                   NFC_LLCP_DIRECTION_TX);
670
671                         ret = nfc_data_exchange(local->dev, local->target_idx,
672                                                 skb, nfc_llcp_recv, local);
673
674                         if (ret) {
675                                 kfree_skb(copy_skb);
676                                 goto out;
677                         }
678
679                         if (ptype == LLCP_PDU_I && copy_skb)
680                                 skb_queue_tail(&llcp_sock->tx_pending_queue,
681                                                copy_skb);
682                 }
683         } else {
684                 nfc_llcp_send_symm(local->dev);
685         }
686
687 out:
688         mod_timer(&local->link_timer,
689                   jiffies + msecs_to_jiffies(2 * local->remote_lto));
690 }
691
692 static struct nfc_llcp_sock *nfc_llcp_connecting_sock_get(struct nfc_llcp_local *local,
693                                                           u8 ssap)
694 {
695         struct sock *sk;
696         struct nfc_llcp_sock *llcp_sock;
697
698         read_lock(&local->connecting_sockets.lock);
699
700         sk_for_each(sk, &local->connecting_sockets.head) {
701                 llcp_sock = nfc_llcp_sock(sk);
702
703                 if (llcp_sock->ssap == ssap) {
704                         sock_hold(&llcp_sock->sk);
705                         goto out;
706                 }
707         }
708
709         llcp_sock = NULL;
710
711 out:
712         read_unlock(&local->connecting_sockets.lock);
713
714         return llcp_sock;
715 }
716
717 static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local,
718                                                   u8 *sn, size_t sn_len)
719 {
720         struct nfc_llcp_sock *llcp_sock;
721
722         llcp_sock = nfc_llcp_sock_from_sn(local, sn, sn_len);
723
724         if (llcp_sock == NULL)
725                 return NULL;
726
727         sock_hold(&llcp_sock->sk);
728
729         return llcp_sock;
730 }
731
732 static u8 *nfc_llcp_connect_sn(struct sk_buff *skb, size_t *sn_len)
733 {
734         u8 *tlv = &skb->data[2], type, length;
735         size_t tlv_array_len = skb->len - LLCP_HEADER_SIZE, offset = 0;
736
737         while (offset < tlv_array_len) {
738                 type = tlv[0];
739                 length = tlv[1];
740
741                 pr_debug("type 0x%x length %d\n", type, length);
742
743                 if (type == LLCP_TLV_SN) {
744                         *sn_len = length;
745                         return &tlv[2];
746                 }
747
748                 offset += length + 2;
749                 tlv += length + 2;
750         }
751
752         return NULL;
753 }
754
755 static void nfc_llcp_recv_ui(struct nfc_llcp_local *local,
756                              struct sk_buff *skb)
757 {
758         struct nfc_llcp_sock *llcp_sock;
759         struct nfc_llcp_ui_cb *ui_cb;
760         u8 dsap, ssap;
761
762         dsap = nfc_llcp_dsap(skb);
763         ssap = nfc_llcp_ssap(skb);
764
765         ui_cb = nfc_llcp_ui_skb_cb(skb);
766         ui_cb->dsap = dsap;
767         ui_cb->ssap = ssap;
768
769         printk("%s %d %d\n", __func__, dsap, ssap);
770
771         pr_debug("%d %d\n", dsap, ssap);
772
773         /* We're looking for a bound socket, not a client one */
774         llcp_sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
775         if (llcp_sock == NULL || llcp_sock->sk.sk_type != SOCK_DGRAM)
776                 return;
777
778         /* There is no sequence with UI frames */
779         skb_pull(skb, LLCP_HEADER_SIZE);
780         if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
781                 /*
782                  * UI frames will be freed from the socket layer, so we
783                  * need to keep them alive until someone receives them.
784                  */
785                 skb_get(skb);
786         } else {
787                 pr_err("Receive queue is full\n");
788                 kfree_skb(skb);
789         }
790
791         nfc_llcp_sock_put(llcp_sock);
792 }
793
794 static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
795                                   struct sk_buff *skb)
796 {
797         struct sock *new_sk, *parent;
798         struct nfc_llcp_sock *sock, *new_sock;
799         u8 dsap, ssap, reason;
800
801         dsap = nfc_llcp_dsap(skb);
802         ssap = nfc_llcp_ssap(skb);
803
804         pr_debug("%d %d\n", dsap, ssap);
805
806         if (dsap != LLCP_SAP_SDP) {
807                 sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
808                 if (sock == NULL || sock->sk.sk_state != LLCP_LISTEN) {
809                         reason = LLCP_DM_NOBOUND;
810                         goto fail;
811                 }
812         } else {
813                 u8 *sn;
814                 size_t sn_len;
815
816                 sn = nfc_llcp_connect_sn(skb, &sn_len);
817                 if (sn == NULL) {
818                         reason = LLCP_DM_NOBOUND;
819                         goto fail;
820                 }
821
822                 pr_debug("Service name length %zu\n", sn_len);
823
824                 sock = nfc_llcp_sock_get_sn(local, sn, sn_len);
825                 if (sock == NULL) {
826                         reason = LLCP_DM_NOBOUND;
827                         goto fail;
828                 }
829         }
830
831         lock_sock(&sock->sk);
832
833         parent = &sock->sk;
834
835         if (sk_acceptq_is_full(parent)) {
836                 reason = LLCP_DM_REJ;
837                 release_sock(&sock->sk);
838                 sock_put(&sock->sk);
839                 goto fail;
840         }
841
842         if (sock->ssap == LLCP_SDP_UNBOUND) {
843                 u8 ssap = nfc_llcp_reserve_sdp_ssap(local);
844
845                 pr_debug("First client, reserving %d\n", ssap);
846
847                 if (ssap == LLCP_SAP_MAX) {
848                         reason = LLCP_DM_REJ;
849                         release_sock(&sock->sk);
850                         sock_put(&sock->sk);
851                         goto fail;
852                 }
853
854                 sock->ssap = ssap;
855         }
856
857         new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC);
858         if (new_sk == NULL) {
859                 reason = LLCP_DM_REJ;
860                 release_sock(&sock->sk);
861                 sock_put(&sock->sk);
862                 goto fail;
863         }
864
865         new_sock = nfc_llcp_sock(new_sk);
866         new_sock->dev = local->dev;
867         new_sock->local = nfc_llcp_local_get(local);
868         new_sock->miu = local->remote_miu;
869         new_sock->nfc_protocol = sock->nfc_protocol;
870         new_sock->dsap = ssap;
871         new_sock->target_idx = local->target_idx;
872         new_sock->parent = parent;
873         new_sock->ssap = sock->ssap;
874         if (sock->ssap < LLCP_LOCAL_NUM_SAP && sock->ssap >= LLCP_WKS_NUM_SAP) {
875                 atomic_t *client_count;
876
877                 pr_debug("reserved_ssap %d for %p\n", sock->ssap, new_sock);
878
879                 client_count =
880                         &local->local_sdp_cnt[sock->ssap - LLCP_WKS_NUM_SAP];
881
882                 atomic_inc(client_count);
883                 new_sock->reserved_ssap = sock->ssap;
884         }
885
886         nfc_llcp_parse_connection_tlv(new_sock, &skb->data[LLCP_HEADER_SIZE],
887                                       skb->len - LLCP_HEADER_SIZE);
888
889         pr_debug("new sock %p sk %p\n", new_sock, &new_sock->sk);
890
891         nfc_llcp_sock_link(&local->sockets, new_sk);
892
893         nfc_llcp_accept_enqueue(&sock->sk, new_sk);
894
895         nfc_get_device(local->dev->idx);
896
897         new_sk->sk_state = LLCP_CONNECTED;
898
899         /* Wake the listening processes */
900         parent->sk_data_ready(parent, 0);
901
902         /* Send CC */
903         nfc_llcp_send_cc(new_sock);
904
905         release_sock(&sock->sk);
906         sock_put(&sock->sk);
907
908         return;
909
910 fail:
911         /* Send DM */
912         nfc_llcp_send_dm(local, dsap, ssap, reason);
913 }
914
915 int nfc_llcp_queue_i_frames(struct nfc_llcp_sock *sock)
916 {
917         int nr_frames = 0;
918         struct nfc_llcp_local *local = sock->local;
919
920         pr_debug("Remote ready %d tx queue len %d remote rw %d",
921                  sock->remote_ready, skb_queue_len(&sock->tx_pending_queue),
922                  sock->rw);
923
924         /* Try to queue some I frames for transmission */
925         while (sock->remote_ready &&
926                skb_queue_len(&sock->tx_pending_queue) < sock->rw) {
927                 struct sk_buff *pdu;
928
929                 pdu = skb_dequeue(&sock->tx_queue);
930                 if (pdu == NULL)
931                         break;
932
933                 /* Update N(S)/N(R) */
934                 nfc_llcp_set_nrns(sock, pdu);
935
936                 skb_queue_tail(&local->tx_queue, pdu);
937                 nr_frames++;
938         }
939
940         return nr_frames;
941 }
942
943 static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local,
944                                struct sk_buff *skb)
945 {
946         struct nfc_llcp_sock *llcp_sock;
947         struct sock *sk;
948         u8 dsap, ssap, ptype, ns, nr;
949
950         ptype = nfc_llcp_ptype(skb);
951         dsap = nfc_llcp_dsap(skb);
952         ssap = nfc_llcp_ssap(skb);
953         ns = nfc_llcp_ns(skb);
954         nr = nfc_llcp_nr(skb);
955
956         pr_debug("%d %d R %d S %d\n", dsap, ssap, nr, ns);
957
958         llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
959         if (llcp_sock == NULL) {
960                 nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
961                 return;
962         }
963
964         sk = &llcp_sock->sk;
965         lock_sock(sk);
966         if (sk->sk_state == LLCP_CLOSED) {
967                 release_sock(sk);
968                 nfc_llcp_sock_put(llcp_sock);
969         }
970
971         /* Pass the payload upstream */
972         if (ptype == LLCP_PDU_I) {
973                 pr_debug("I frame, queueing on %p\n", &llcp_sock->sk);
974
975                 if (ns == llcp_sock->recv_n)
976                         llcp_sock->recv_n = (llcp_sock->recv_n + 1) % 16;
977                 else
978                         pr_err("Received out of sequence I PDU\n");
979
980                 skb_pull(skb, LLCP_HEADER_SIZE + LLCP_SEQUENCE_SIZE);
981                 if (!sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
982                         /*
983                          * I frames will be freed from the socket layer, so we
984                          * need to keep them alive until someone receives them.
985                          */
986                         skb_get(skb);
987                 } else {
988                         pr_err("Receive queue is full\n");
989                         kfree_skb(skb);
990                 }
991         }
992
993         /* Remove skbs from the pending queue */
994         if (llcp_sock->send_ack_n != nr) {
995                 struct sk_buff *s, *tmp;
996                 u8 n;
997
998                 llcp_sock->send_ack_n = nr;
999
1000                 /* Remove and free all skbs until ns == nr */
1001                 skb_queue_walk_safe(&llcp_sock->tx_pending_queue, s, tmp) {
1002                         n = nfc_llcp_ns(s);
1003
1004                         skb_unlink(s, &llcp_sock->tx_pending_queue);
1005                         kfree_skb(s);
1006
1007                         if (n == nr)
1008                                 break;
1009                 }
1010
1011                 /* Re-queue the remaining skbs for transmission */
1012                 skb_queue_reverse_walk_safe(&llcp_sock->tx_pending_queue,
1013                                             s, tmp) {
1014                         skb_unlink(s, &llcp_sock->tx_pending_queue);
1015                         skb_queue_head(&local->tx_queue, s);
1016                 }
1017         }
1018
1019         if (ptype == LLCP_PDU_RR)
1020                 llcp_sock->remote_ready = true;
1021         else if (ptype == LLCP_PDU_RNR)
1022                 llcp_sock->remote_ready = false;
1023
1024         if (nfc_llcp_queue_i_frames(llcp_sock) == 0 && ptype == LLCP_PDU_I)
1025                 nfc_llcp_send_rr(llcp_sock);
1026
1027         release_sock(sk);
1028         nfc_llcp_sock_put(llcp_sock);
1029 }
1030
1031 static void nfc_llcp_recv_disc(struct nfc_llcp_local *local,
1032                                struct sk_buff *skb)
1033 {
1034         struct nfc_llcp_sock *llcp_sock;
1035         struct sock *sk;
1036         u8 dsap, ssap;
1037
1038         dsap = nfc_llcp_dsap(skb);
1039         ssap = nfc_llcp_ssap(skb);
1040
1041         llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1042         if (llcp_sock == NULL) {
1043                 nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1044                 return;
1045         }
1046
1047         sk = &llcp_sock->sk;
1048         lock_sock(sk);
1049
1050         nfc_llcp_socket_purge(llcp_sock);
1051
1052         if (sk->sk_state == LLCP_CLOSED) {
1053                 release_sock(sk);
1054                 nfc_llcp_sock_put(llcp_sock);
1055         }
1056
1057         if (sk->sk_state == LLCP_CONNECTED) {
1058                 nfc_put_device(local->dev);
1059                 sk->sk_state = LLCP_CLOSED;
1060                 sk->sk_state_change(sk);
1061         }
1062
1063         nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_DISC);
1064
1065         release_sock(sk);
1066         nfc_llcp_sock_put(llcp_sock);
1067 }
1068
1069 static void nfc_llcp_recv_cc(struct nfc_llcp_local *local, struct sk_buff *skb)
1070 {
1071         struct nfc_llcp_sock *llcp_sock;
1072         struct sock *sk;
1073         u8 dsap, ssap;
1074
1075         dsap = nfc_llcp_dsap(skb);
1076         ssap = nfc_llcp_ssap(skb);
1077
1078         llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1079         if (llcp_sock == NULL) {
1080                 pr_err("Invalid CC\n");
1081                 nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1082
1083                 return;
1084         }
1085
1086         sk = &llcp_sock->sk;
1087
1088         /* Unlink from connecting and link to the client array */
1089         nfc_llcp_sock_unlink(&local->connecting_sockets, sk);
1090         nfc_llcp_sock_link(&local->sockets, sk);
1091         llcp_sock->dsap = ssap;
1092
1093         nfc_llcp_parse_connection_tlv(llcp_sock, &skb->data[LLCP_HEADER_SIZE],
1094                                       skb->len - LLCP_HEADER_SIZE);
1095
1096         sk->sk_state = LLCP_CONNECTED;
1097         sk->sk_state_change(sk);
1098
1099         nfc_llcp_sock_put(llcp_sock);
1100 }
1101
1102 static void nfc_llcp_recv_dm(struct nfc_llcp_local *local, struct sk_buff *skb)
1103 {
1104         struct nfc_llcp_sock *llcp_sock;
1105         struct sock *sk;
1106         u8 dsap, ssap, reason;
1107
1108         dsap = nfc_llcp_dsap(skb);
1109         ssap = nfc_llcp_ssap(skb);
1110         reason = skb->data[2];
1111
1112         pr_debug("%d %d reason %d\n", ssap, dsap, reason);
1113
1114         switch (reason) {
1115         case LLCP_DM_NOBOUND:
1116         case LLCP_DM_REJ:
1117                 llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1118                 break;
1119
1120         default:
1121                 llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1122                 break;
1123         }
1124
1125         if (llcp_sock == NULL) {
1126                 pr_debug("Already closed\n");
1127                 return;
1128         }
1129
1130         sk = &llcp_sock->sk;
1131
1132         sk->sk_err = ENXIO;
1133         sk->sk_state = LLCP_CLOSED;
1134         sk->sk_state_change(sk);
1135
1136         nfc_llcp_sock_put(llcp_sock);
1137 }
1138
1139 static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
1140                               struct sk_buff *skb)
1141 {
1142         struct nfc_llcp_sock *llcp_sock;
1143         u8 dsap, ssap, *tlv, type, length, tid, sap;
1144         u16 tlv_len, offset;
1145         char *service_name;
1146         size_t service_name_len;
1147
1148         dsap = nfc_llcp_dsap(skb);
1149         ssap = nfc_llcp_ssap(skb);
1150
1151         pr_debug("%d %d\n", dsap, ssap);
1152
1153         if (dsap != LLCP_SAP_SDP || ssap != LLCP_SAP_SDP) {
1154                 pr_err("Wrong SNL SAP\n");
1155                 return;
1156         }
1157
1158         tlv = &skb->data[LLCP_HEADER_SIZE];
1159         tlv_len = skb->len - LLCP_HEADER_SIZE;
1160         offset = 0;
1161
1162         while (offset < tlv_len) {
1163                 type = tlv[0];
1164                 length = tlv[1];
1165
1166                 switch (type) {
1167                 case LLCP_TLV_SDREQ:
1168                         tid = tlv[2];
1169                         service_name = (char *) &tlv[3];
1170                         service_name_len = length - 1;
1171
1172                         pr_debug("Looking for %.16s\n", service_name);
1173
1174                         if (service_name_len == strlen("urn:nfc:sn:sdp") &&
1175                             !strncmp(service_name, "urn:nfc:sn:sdp",
1176                                      service_name_len)) {
1177                                 sap = 1;
1178                                 goto send_snl;
1179                         }
1180
1181                         llcp_sock = nfc_llcp_sock_from_sn(local, service_name,
1182                                                           service_name_len);
1183                         if (!llcp_sock) {
1184                                 sap = 0;
1185                                 goto send_snl;
1186                         }
1187
1188                         /*
1189                          * We found a socket but its ssap has not been reserved
1190                          * yet. We need to assign it for good and send a reply.
1191                          * The ssap will be freed when the socket is closed.
1192                          */
1193                         if (llcp_sock->ssap == LLCP_SDP_UNBOUND) {
1194                                 atomic_t *client_count;
1195
1196                                 sap = nfc_llcp_reserve_sdp_ssap(local);
1197
1198                                 pr_debug("Reserving %d\n", sap);
1199
1200                                 if (sap == LLCP_SAP_MAX) {
1201                                         sap = 0;
1202                                         goto send_snl;
1203                                 }
1204
1205                                 client_count =
1206                                         &local->local_sdp_cnt[sap -
1207                                                               LLCP_WKS_NUM_SAP];
1208
1209                                 atomic_inc(client_count);
1210
1211                                 llcp_sock->ssap = sap;
1212                                 llcp_sock->reserved_ssap = sap;
1213                         } else {
1214                                 sap = llcp_sock->ssap;
1215                         }
1216
1217                         pr_debug("%p %d\n", llcp_sock, sap);
1218
1219 send_snl:
1220                         nfc_llcp_send_snl(local, tid, sap);
1221                         break;
1222
1223                 default:
1224                         pr_err("Invalid SNL tlv value 0x%x\n", type);
1225                         break;
1226                 }
1227
1228                 offset += length + 2;
1229                 tlv += length + 2;
1230         }
1231 }
1232
1233 static void nfc_llcp_rx_work(struct work_struct *work)
1234 {
1235         struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
1236                                                     rx_work);
1237         u8 dsap, ssap, ptype;
1238         struct sk_buff *skb;
1239
1240         skb = local->rx_pending;
1241         if (skb == NULL) {
1242                 pr_debug("No pending SKB\n");
1243                 return;
1244         }
1245
1246         ptype = nfc_llcp_ptype(skb);
1247         dsap = nfc_llcp_dsap(skb);
1248         ssap = nfc_llcp_ssap(skb);
1249
1250         pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
1251
1252         if (ptype != LLCP_PDU_SYMM)
1253                 print_hex_dump(KERN_DEBUG, "LLCP Rx: ", DUMP_PREFIX_OFFSET,
1254                                16, 1, skb->data, skb->len, true);
1255
1256         __net_timestamp(skb);
1257
1258         nfc_llcp_send_to_raw_sock(local, skb, NFC_LLCP_DIRECTION_RX);
1259
1260         switch (ptype) {
1261         case LLCP_PDU_SYMM:
1262                 pr_debug("SYMM\n");
1263                 break;
1264
1265         case LLCP_PDU_UI:
1266                 pr_debug("UI\n");
1267                 nfc_llcp_recv_ui(local, skb);
1268                 break;
1269
1270         case LLCP_PDU_CONNECT:
1271                 pr_debug("CONNECT\n");
1272                 nfc_llcp_recv_connect(local, skb);
1273                 break;
1274
1275         case LLCP_PDU_DISC:
1276                 pr_debug("DISC\n");
1277                 nfc_llcp_recv_disc(local, skb);
1278                 break;
1279
1280         case LLCP_PDU_CC:
1281                 pr_debug("CC\n");
1282                 nfc_llcp_recv_cc(local, skb);
1283                 break;
1284
1285         case LLCP_PDU_DM:
1286                 pr_debug("DM\n");
1287                 nfc_llcp_recv_dm(local, skb);
1288                 break;
1289
1290         case LLCP_PDU_SNL:
1291                 pr_debug("SNL\n");
1292                 nfc_llcp_recv_snl(local, skb);
1293                 break;
1294
1295         case LLCP_PDU_I:
1296         case LLCP_PDU_RR:
1297         case LLCP_PDU_RNR:
1298                 pr_debug("I frame\n");
1299                 nfc_llcp_recv_hdlc(local, skb);
1300                 break;
1301
1302         }
1303
1304         schedule_work(&local->tx_work);
1305         kfree_skb(local->rx_pending);
1306         local->rx_pending = NULL;
1307 }
1308
1309 static void __nfc_llcp_recv(struct nfc_llcp_local *local, struct sk_buff *skb)
1310 {
1311         local->rx_pending = skb;
1312         del_timer(&local->link_timer);
1313         schedule_work(&local->rx_work);
1314 }
1315
1316 void nfc_llcp_recv(void *data, struct sk_buff *skb, int err)
1317 {
1318         struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
1319
1320         pr_debug("Received an LLCP PDU\n");
1321         if (err < 0) {
1322                 pr_err("err %d\n", err);
1323                 return;
1324         }
1325
1326         __nfc_llcp_recv(local, skb);
1327 }
1328
1329 int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb)
1330 {
1331         struct nfc_llcp_local *local;
1332
1333         local = nfc_llcp_find_local(dev);
1334         if (local == NULL)
1335                 return -ENODEV;
1336
1337         __nfc_llcp_recv(local, skb);
1338
1339         return 0;
1340 }
1341
1342 void nfc_llcp_mac_is_down(struct nfc_dev *dev)
1343 {
1344         struct nfc_llcp_local *local;
1345
1346         local = nfc_llcp_find_local(dev);
1347         if (local == NULL)
1348                 return;
1349
1350         /* Close and purge all existing sockets */
1351         nfc_llcp_socket_release(local, true);
1352 }
1353
1354 void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
1355                         u8 comm_mode, u8 rf_mode)
1356 {
1357         struct nfc_llcp_local *local;
1358
1359         pr_debug("rf mode %d\n", rf_mode);
1360
1361         local = nfc_llcp_find_local(dev);
1362         if (local == NULL)
1363                 return;
1364
1365         local->target_idx = target_idx;
1366         local->comm_mode = comm_mode;
1367         local->rf_mode = rf_mode;
1368
1369         if (rf_mode == NFC_RF_INITIATOR) {
1370                 pr_debug("Queueing Tx work\n");
1371
1372                 schedule_work(&local->tx_work);
1373         } else {
1374                 mod_timer(&local->link_timer,
1375                           jiffies + msecs_to_jiffies(local->remote_lto));
1376         }
1377 }
1378
1379 int nfc_llcp_register_device(struct nfc_dev *ndev)
1380 {
1381         struct nfc_llcp_local *local;
1382
1383         local = kzalloc(sizeof(struct nfc_llcp_local), GFP_KERNEL);
1384         if (local == NULL)
1385                 return -ENOMEM;
1386
1387         local->dev = ndev;
1388         INIT_LIST_HEAD(&local->list);
1389         kref_init(&local->ref);
1390         mutex_init(&local->sdp_lock);
1391         init_timer(&local->link_timer);
1392         local->link_timer.data = (unsigned long) local;
1393         local->link_timer.function = nfc_llcp_symm_timer;
1394
1395         skb_queue_head_init(&local->tx_queue);
1396         INIT_WORK(&local->tx_work, nfc_llcp_tx_work);
1397
1398         local->rx_pending = NULL;
1399         INIT_WORK(&local->rx_work, nfc_llcp_rx_work);
1400
1401         INIT_WORK(&local->timeout_work, nfc_llcp_timeout_work);
1402
1403         rwlock_init(&local->sockets.lock);
1404         rwlock_init(&local->connecting_sockets.lock);
1405         rwlock_init(&local->raw_sockets.lock);
1406
1407         local->lto = 150; /* 1500 ms */
1408         local->rw = LLCP_MAX_RW;
1409         local->miux = cpu_to_be16(LLCP_MAX_MIUX);
1410
1411         nfc_llcp_build_gb(local);
1412
1413         local->remote_miu = LLCP_DEFAULT_MIU;
1414         local->remote_lto = LLCP_DEFAULT_LTO;
1415
1416         list_add(&local->list, &llcp_devices);
1417
1418         return 0;
1419 }
1420
1421 void nfc_llcp_unregister_device(struct nfc_dev *dev)
1422 {
1423         struct nfc_llcp_local *local = nfc_llcp_find_local(dev);
1424
1425         if (local == NULL) {
1426                 pr_debug("No such device\n");
1427                 return;
1428         }
1429
1430         nfc_llcp_local_put(local);
1431 }
1432
1433 int __init nfc_llcp_init(void)
1434 {
1435         INIT_LIST_HEAD(&llcp_devices);
1436
1437         return nfc_llcp_sock_init();
1438 }
1439
1440 void nfc_llcp_exit(void)
1441 {
1442         nfc_llcp_sock_exit();
1443 }