NFC: llcp: Remove the tx backlog queue
[firefly-linux-kernel-4.4.55.git] / net / nfc / llcp / llcp.c
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 *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, node, 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 hlist_node *node;
175         struct nfc_llcp_sock *llcp_sock, *tmp_sock;
176
177         pr_debug("ssap dsap %d %d\n", ssap, dsap);
178
179         if (ssap == 0 && dsap == 0)
180                 return NULL;
181
182         read_lock(&local->sockets.lock);
183
184         llcp_sock = NULL;
185
186         sk_for_each(sk, node, &local->sockets.head) {
187                 tmp_sock = nfc_llcp_sock(sk);
188
189                 if (tmp_sock->ssap == ssap && tmp_sock->dsap == dsap) {
190                         llcp_sock = tmp_sock;
191                         break;
192                 }
193         }
194
195         read_unlock(&local->sockets.lock);
196
197         if (llcp_sock == NULL)
198                 return NULL;
199
200         sock_hold(&llcp_sock->sk);
201
202         return llcp_sock;
203 }
204
205 static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock)
206 {
207         sock_put(&sock->sk);
208 }
209
210 static void nfc_llcp_timeout_work(struct work_struct *work)
211 {
212         struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
213                                                     timeout_work);
214
215         nfc_dep_link_down(local->dev);
216 }
217
218 static void nfc_llcp_symm_timer(unsigned long data)
219 {
220         struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
221
222         pr_err("SYMM timeout\n");
223
224         schedule_work(&local->timeout_work);
225 }
226
227 struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev)
228 {
229         struct nfc_llcp_local *local, *n;
230
231         list_for_each_entry_safe(local, n, &llcp_devices, list)
232                 if (local->dev == dev)
233                         return local;
234
235         pr_debug("No device found\n");
236
237         return NULL;
238 }
239
240 static char *wks[] = {
241         NULL,
242         NULL, /* SDP */
243         "urn:nfc:sn:ip",
244         "urn:nfc:sn:obex",
245         "urn:nfc:sn:snep",
246 };
247
248 static int nfc_llcp_wks_sap(char *service_name, size_t service_name_len)
249 {
250         int sap, num_wks;
251
252         pr_debug("%s\n", service_name);
253
254         if (service_name == NULL)
255                 return -EINVAL;
256
257         num_wks = ARRAY_SIZE(wks);
258
259         for (sap = 0; sap < num_wks; sap++) {
260                 if (wks[sap] == NULL)
261                         continue;
262
263                 if (strncmp(wks[sap], service_name, service_name_len) == 0)
264                         return sap;
265         }
266
267         return -EINVAL;
268 }
269
270 static
271 struct nfc_llcp_sock *nfc_llcp_sock_from_sn(struct nfc_llcp_local *local,
272                                             u8 *sn, size_t sn_len)
273 {
274         struct sock *sk;
275         struct hlist_node *node;
276         struct nfc_llcp_sock *llcp_sock, *tmp_sock;
277
278         pr_debug("sn %zd %p\n", sn_len, sn);
279
280         if (sn == NULL || sn_len == 0)
281                 return NULL;
282
283         read_lock(&local->sockets.lock);
284
285         llcp_sock = NULL;
286
287         sk_for_each(sk, node, &local->sockets.head) {
288                 tmp_sock = nfc_llcp_sock(sk);
289
290                 pr_debug("llcp sock %p\n", tmp_sock);
291
292                 if (tmp_sock->sk.sk_type == SOCK_STREAM &&
293                     tmp_sock->sk.sk_state != LLCP_LISTEN)
294                         continue;
295
296                 if (tmp_sock->sk.sk_type == SOCK_DGRAM &&
297                     tmp_sock->sk.sk_state != LLCP_BOUND)
298                         continue;
299
300                 if (tmp_sock->service_name == NULL ||
301                     tmp_sock->service_name_len == 0)
302                         continue;
303
304                 if (tmp_sock->service_name_len != sn_len)
305                         continue;
306
307                 if (memcmp(sn, tmp_sock->service_name, sn_len) == 0) {
308                         llcp_sock = tmp_sock;
309                         break;
310                 }
311         }
312
313         read_unlock(&local->sockets.lock);
314
315         pr_debug("Found llcp sock %p\n", llcp_sock);
316
317         return llcp_sock;
318 }
319
320 u8 nfc_llcp_get_sdp_ssap(struct nfc_llcp_local *local,
321                          struct nfc_llcp_sock *sock)
322 {
323         mutex_lock(&local->sdp_lock);
324
325         if (sock->service_name != NULL && sock->service_name_len > 0) {
326                 int ssap = nfc_llcp_wks_sap(sock->service_name,
327                                             sock->service_name_len);
328
329                 if (ssap > 0) {
330                         pr_debug("WKS %d\n", ssap);
331
332                         /* This is a WKS, let's check if it's free */
333                         if (local->local_wks & BIT(ssap)) {
334                                 mutex_unlock(&local->sdp_lock);
335
336                                 return LLCP_SAP_MAX;
337                         }
338
339                         set_bit(ssap, &local->local_wks);
340                         mutex_unlock(&local->sdp_lock);
341
342                         return ssap;
343                 }
344
345                 /*
346                  * Check if there already is a non WKS socket bound
347                  * to this service name.
348                  */
349                 if (nfc_llcp_sock_from_sn(local, sock->service_name,
350                                           sock->service_name_len) != NULL) {
351                         mutex_unlock(&local->sdp_lock);
352
353                         return LLCP_SAP_MAX;
354                 }
355
356                 mutex_unlock(&local->sdp_lock);
357
358                 return LLCP_SDP_UNBOUND;
359
360         } else if (sock->ssap != 0 && sock->ssap < LLCP_WKS_NUM_SAP) {
361                 if (!test_bit(sock->ssap, &local->local_wks)) {
362                         set_bit(sock->ssap, &local->local_wks);
363                         mutex_unlock(&local->sdp_lock);
364
365                         return sock->ssap;
366                 }
367         }
368
369         mutex_unlock(&local->sdp_lock);
370
371         return LLCP_SAP_MAX;
372 }
373
374 u8 nfc_llcp_get_local_ssap(struct nfc_llcp_local *local)
375 {
376         u8 local_ssap;
377
378         mutex_lock(&local->sdp_lock);
379
380         local_ssap = find_first_zero_bit(&local->local_sap, LLCP_LOCAL_NUM_SAP);
381         if (local_ssap == LLCP_LOCAL_NUM_SAP) {
382                 mutex_unlock(&local->sdp_lock);
383                 return LLCP_SAP_MAX;
384         }
385
386         set_bit(local_ssap, &local->local_sap);
387
388         mutex_unlock(&local->sdp_lock);
389
390         return local_ssap + LLCP_LOCAL_SAP_OFFSET;
391 }
392
393 void nfc_llcp_put_ssap(struct nfc_llcp_local *local, u8 ssap)
394 {
395         u8 local_ssap;
396         unsigned long *sdp;
397
398         if (ssap < LLCP_WKS_NUM_SAP) {
399                 local_ssap = ssap;
400                 sdp = &local->local_wks;
401         } else if (ssap < LLCP_LOCAL_NUM_SAP) {
402                 atomic_t *client_cnt;
403
404                 local_ssap = ssap - LLCP_WKS_NUM_SAP;
405                 sdp = &local->local_sdp;
406                 client_cnt = &local->local_sdp_cnt[local_ssap];
407
408                 pr_debug("%d clients\n", atomic_read(client_cnt));
409
410                 mutex_lock(&local->sdp_lock);
411
412                 if (atomic_dec_and_test(client_cnt)) {
413                         struct nfc_llcp_sock *l_sock;
414
415                         pr_debug("No more clients for SAP %d\n", ssap);
416
417                         clear_bit(local_ssap, sdp);
418
419                         /* Find the listening sock and set it back to UNBOUND */
420                         l_sock = nfc_llcp_sock_get(local, ssap, LLCP_SAP_SDP);
421                         if (l_sock) {
422                                 l_sock->ssap = LLCP_SDP_UNBOUND;
423                                 nfc_llcp_sock_put(l_sock);
424                         }
425                 }
426
427                 mutex_unlock(&local->sdp_lock);
428
429                 return;
430         } else if (ssap < LLCP_MAX_SAP) {
431                 local_ssap = ssap - LLCP_LOCAL_NUM_SAP;
432                 sdp = &local->local_sap;
433         } else {
434                 return;
435         }
436
437         mutex_lock(&local->sdp_lock);
438
439         clear_bit(local_ssap, sdp);
440
441         mutex_unlock(&local->sdp_lock);
442 }
443
444 static u8 nfc_llcp_reserve_sdp_ssap(struct nfc_llcp_local *local)
445 {
446         u8 ssap;
447
448         mutex_lock(&local->sdp_lock);
449
450         ssap = find_first_zero_bit(&local->local_sdp, LLCP_SDP_NUM_SAP);
451         if (ssap == LLCP_SDP_NUM_SAP) {
452                 mutex_unlock(&local->sdp_lock);
453
454                 return LLCP_SAP_MAX;
455         }
456
457         pr_debug("SDP ssap %d\n", LLCP_WKS_NUM_SAP + ssap);
458
459         set_bit(ssap, &local->local_sdp);
460
461         mutex_unlock(&local->sdp_lock);
462
463         return LLCP_WKS_NUM_SAP + ssap;
464 }
465
466 static int nfc_llcp_build_gb(struct nfc_llcp_local *local)
467 {
468         u8 *gb_cur, *version_tlv, version, version_length;
469         u8 *lto_tlv, lto_length;
470         u8 *wks_tlv, wks_length;
471         u8 *miux_tlv, miux_length;
472         u8 gb_len = 0;
473         int ret = 0;
474
475         version = LLCP_VERSION_11;
476         version_tlv = nfc_llcp_build_tlv(LLCP_TLV_VERSION, &version,
477                                          1, &version_length);
478         gb_len += version_length;
479
480         lto_tlv = nfc_llcp_build_tlv(LLCP_TLV_LTO, &local->lto, 1, &lto_length);
481         gb_len += lto_length;
482
483         pr_debug("Local wks 0x%lx\n", local->local_wks);
484         wks_tlv = nfc_llcp_build_tlv(LLCP_TLV_WKS, (u8 *)&local->local_wks, 2,
485                                      &wks_length);
486         gb_len += wks_length;
487
488         miux_tlv = nfc_llcp_build_tlv(LLCP_TLV_MIUX, (u8 *)&local->miux, 0,
489                                       &miux_length);
490         gb_len += miux_length;
491
492         gb_len += ARRAY_SIZE(llcp_magic);
493
494         if (gb_len > NFC_MAX_GT_LEN) {
495                 ret = -EINVAL;
496                 goto out;
497         }
498
499         gb_cur = local->gb;
500
501         memcpy(gb_cur, llcp_magic, ARRAY_SIZE(llcp_magic));
502         gb_cur += ARRAY_SIZE(llcp_magic);
503
504         memcpy(gb_cur, version_tlv, version_length);
505         gb_cur += version_length;
506
507         memcpy(gb_cur, lto_tlv, lto_length);
508         gb_cur += lto_length;
509
510         memcpy(gb_cur, wks_tlv, wks_length);
511         gb_cur += wks_length;
512
513         memcpy(gb_cur, miux_tlv, miux_length);
514         gb_cur += miux_length;
515
516         local->gb_len = gb_len;
517
518 out:
519         kfree(version_tlv);
520         kfree(lto_tlv);
521         kfree(wks_tlv);
522         kfree(miux_tlv);
523
524         return ret;
525 }
526
527 u8 *nfc_llcp_general_bytes(struct nfc_dev *dev, size_t *general_bytes_len)
528 {
529         struct nfc_llcp_local *local;
530
531         local = nfc_llcp_find_local(dev);
532         if (local == NULL) {
533                 *general_bytes_len = 0;
534                 return NULL;
535         }
536
537         nfc_llcp_build_gb(local);
538
539         *general_bytes_len = local->gb_len;
540
541         return local->gb;
542 }
543
544 int nfc_llcp_set_remote_gb(struct nfc_dev *dev, u8 *gb, u8 gb_len)
545 {
546         struct nfc_llcp_local *local = nfc_llcp_find_local(dev);
547
548         if (local == NULL) {
549                 pr_err("No LLCP device\n");
550                 return -ENODEV;
551         }
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 (local->remote_gb == NULL || local->remote_gb_len == 0)
558                 return -ENODEV;
559
560         if (memcmp(local->remote_gb, llcp_magic, 3)) {
561                 pr_err("MAC does not support LLCP\n");
562                 return -EINVAL;
563         }
564
565         return nfc_llcp_parse_gb_tlv(local,
566                                      &local->remote_gb[3],
567                                      local->remote_gb_len - 3);
568 }
569
570 static u8 nfc_llcp_dsap(struct sk_buff *pdu)
571 {
572         return (pdu->data[0] & 0xfc) >> 2;
573 }
574
575 static u8 nfc_llcp_ptype(struct sk_buff *pdu)
576 {
577         return ((pdu->data[0] & 0x03) << 2) | ((pdu->data[1] & 0xc0) >> 6);
578 }
579
580 static u8 nfc_llcp_ssap(struct sk_buff *pdu)
581 {
582         return pdu->data[1] & 0x3f;
583 }
584
585 static u8 nfc_llcp_ns(struct sk_buff *pdu)
586 {
587         return pdu->data[2] >> 4;
588 }
589
590 static u8 nfc_llcp_nr(struct sk_buff *pdu)
591 {
592         return pdu->data[2] & 0xf;
593 }
594
595 static void nfc_llcp_set_nrns(struct nfc_llcp_sock *sock, struct sk_buff *pdu)
596 {
597         pdu->data[2] = (sock->send_n << 4) | (sock->recv_n);
598         sock->send_n = (sock->send_n + 1) % 16;
599         sock->recv_ack_n = (sock->recv_n - 1) % 16;
600 }
601
602 void nfc_llcp_send_to_raw_sock(struct nfc_llcp_local *local,
603                                struct sk_buff *skb, u8 direction)
604 {
605         struct hlist_node *node;
606         struct sk_buff *skb_copy = NULL, *nskb;
607         struct sock *sk;
608         u8 *data;
609
610         read_lock(&local->raw_sockets.lock);
611
612         sk_for_each(sk, node, &local->raw_sockets.head) {
613                 if (sk->sk_state != LLCP_BOUND)
614                         continue;
615
616                 if (skb_copy == NULL) {
617                         skb_copy = __pskb_copy(skb, NFC_LLCP_RAW_HEADER_SIZE,
618                                                GFP_ATOMIC);
619
620                         if (skb_copy == NULL)
621                                 continue;
622
623                         data = skb_push(skb_copy, NFC_LLCP_RAW_HEADER_SIZE);
624
625                         data[0] = local->dev ? local->dev->idx : 0xFF;
626                         data[1] = direction;
627                 }
628
629                 nskb = skb_clone(skb_copy, GFP_ATOMIC);
630                 if (!nskb)
631                         continue;
632
633                 if (sock_queue_rcv_skb(sk, nskb))
634                         kfree_skb(nskb);
635         }
636
637         read_unlock(&local->raw_sockets.lock);
638
639         kfree_skb(skb_copy);
640 }
641
642 static void nfc_llcp_tx_work(struct work_struct *work)
643 {
644         struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
645                                                     tx_work);
646         struct sk_buff *skb;
647         struct sock *sk;
648         struct nfc_llcp_sock *llcp_sock;
649
650         skb = skb_dequeue(&local->tx_queue);
651         if (skb != NULL) {
652                 sk = skb->sk;
653                 llcp_sock = nfc_llcp_sock(sk);
654
655                 if (llcp_sock == NULL && nfc_llcp_ptype(skb) == LLCP_PDU_I) {
656                         nfc_llcp_send_symm(local->dev);
657                 } else {
658                         struct sk_buff *copy_skb = NULL;
659                         u8 ptype = nfc_llcp_ptype(skb);
660                         int ret;
661
662                         pr_debug("Sending pending skb\n");
663                         print_hex_dump(KERN_DEBUG, "LLCP Tx: ",
664                                        DUMP_PREFIX_OFFSET, 16, 1,
665                                        skb->data, skb->len, true);
666
667                         if (ptype == LLCP_PDU_I)
668                                 copy_skb = skb_copy(skb, GFP_ATOMIC);
669
670                         __net_timestamp(skb);
671
672                         nfc_llcp_send_to_raw_sock(local, skb,
673                                                   NFC_LLCP_DIRECTION_TX);
674
675                         ret = nfc_data_exchange(local->dev, local->target_idx,
676                                                 skb, nfc_llcp_recv, local);
677
678                         if (ret) {
679                                 kfree_skb(copy_skb);
680                                 goto out;
681                         }
682
683                         if (ptype == LLCP_PDU_I && copy_skb)
684                                 skb_queue_tail(&llcp_sock->tx_pending_queue,
685                                                copy_skb);
686                 }
687         } else {
688                 nfc_llcp_send_symm(local->dev);
689         }
690
691 out:
692         mod_timer(&local->link_timer,
693                   jiffies + msecs_to_jiffies(2 * local->remote_lto));
694 }
695
696 static struct nfc_llcp_sock *nfc_llcp_connecting_sock_get(struct nfc_llcp_local *local,
697                                                           u8 ssap)
698 {
699         struct sock *sk;
700         struct nfc_llcp_sock *llcp_sock;
701         struct hlist_node *node;
702
703         read_lock(&local->connecting_sockets.lock);
704
705         sk_for_each(sk, node, &local->connecting_sockets.head) {
706                 llcp_sock = nfc_llcp_sock(sk);
707
708                 if (llcp_sock->ssap == ssap) {
709                         sock_hold(&llcp_sock->sk);
710                         goto out;
711                 }
712         }
713
714         llcp_sock = NULL;
715
716 out:
717         read_unlock(&local->connecting_sockets.lock);
718
719         return llcp_sock;
720 }
721
722 static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local,
723                                                   u8 *sn, size_t sn_len)
724 {
725         struct nfc_llcp_sock *llcp_sock;
726
727         llcp_sock = nfc_llcp_sock_from_sn(local, sn, sn_len);
728
729         if (llcp_sock == NULL)
730                 return NULL;
731
732         sock_hold(&llcp_sock->sk);
733
734         return llcp_sock;
735 }
736
737 static u8 *nfc_llcp_connect_sn(struct sk_buff *skb, size_t *sn_len)
738 {
739         u8 *tlv = &skb->data[2], type, length;
740         size_t tlv_array_len = skb->len - LLCP_HEADER_SIZE, offset = 0;
741
742         while (offset < tlv_array_len) {
743                 type = tlv[0];
744                 length = tlv[1];
745
746                 pr_debug("type 0x%x length %d\n", type, length);
747
748                 if (type == LLCP_TLV_SN) {
749                         *sn_len = length;
750                         return &tlv[2];
751                 }
752
753                 offset += length + 2;
754                 tlv += length + 2;
755         }
756
757         return NULL;
758 }
759
760 static void nfc_llcp_recv_ui(struct nfc_llcp_local *local,
761                              struct sk_buff *skb)
762 {
763         struct nfc_llcp_sock *llcp_sock;
764         struct nfc_llcp_ui_cb *ui_cb;
765         u8 dsap, ssap;
766
767         dsap = nfc_llcp_dsap(skb);
768         ssap = nfc_llcp_ssap(skb);
769
770         ui_cb = nfc_llcp_ui_skb_cb(skb);
771         ui_cb->dsap = dsap;
772         ui_cb->ssap = ssap;
773
774         printk("%s %d %d\n", __func__, dsap, ssap);
775
776         pr_debug("%d %d\n", dsap, ssap);
777
778         /* We're looking for a bound socket, not a client one */
779         llcp_sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
780         if (llcp_sock == NULL || llcp_sock->sk.sk_type != SOCK_DGRAM)
781                 return;
782
783         /* There is no sequence with UI frames */
784         skb_pull(skb, LLCP_HEADER_SIZE);
785         if (sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
786                 pr_err("receive queue is full\n");
787                 kfree_skb(skb);
788         }
789
790         nfc_llcp_sock_put(llcp_sock);
791 }
792
793 static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
794                                   struct sk_buff *skb)
795 {
796         struct sock *new_sk, *parent;
797         struct nfc_llcp_sock *sock, *new_sock;
798         u8 dsap, ssap, reason;
799
800         dsap = nfc_llcp_dsap(skb);
801         ssap = nfc_llcp_ssap(skb);
802
803         pr_debug("%d %d\n", dsap, ssap);
804
805         if (dsap != LLCP_SAP_SDP) {
806                 sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
807                 if (sock == NULL || sock->sk.sk_state != LLCP_LISTEN) {
808                         reason = LLCP_DM_NOBOUND;
809                         goto fail;
810                 }
811         } else {
812                 u8 *sn;
813                 size_t sn_len;
814
815                 sn = nfc_llcp_connect_sn(skb, &sn_len);
816                 if (sn == NULL) {
817                         reason = LLCP_DM_NOBOUND;
818                         goto fail;
819                 }
820
821                 pr_debug("Service name length %zu\n", sn_len);
822
823                 sock = nfc_llcp_sock_get_sn(local, sn, sn_len);
824                 if (sock == NULL) {
825                         reason = LLCP_DM_NOBOUND;
826                         goto fail;
827                 }
828         }
829
830         lock_sock(&sock->sk);
831
832         parent = &sock->sk;
833
834         if (sk_acceptq_is_full(parent)) {
835                 reason = LLCP_DM_REJ;
836                 release_sock(&sock->sk);
837                 sock_put(&sock->sk);
838                 goto fail;
839         }
840
841         if (sock->ssap == LLCP_SDP_UNBOUND) {
842                 u8 ssap = nfc_llcp_reserve_sdp_ssap(local);
843
844                 pr_debug("First client, reserving %d\n", ssap);
845
846                 if (ssap == LLCP_SAP_MAX) {
847                         reason = LLCP_DM_REJ;
848                         release_sock(&sock->sk);
849                         sock_put(&sock->sk);
850                         goto fail;
851                 }
852
853                 sock->ssap = ssap;
854         }
855
856         new_sk = nfc_llcp_sock_alloc(NULL, parent->sk_type, GFP_ATOMIC);
857         if (new_sk == NULL) {
858                 reason = LLCP_DM_REJ;
859                 release_sock(&sock->sk);
860                 sock_put(&sock->sk);
861                 goto fail;
862         }
863
864         new_sock = nfc_llcp_sock(new_sk);
865         new_sock->dev = local->dev;
866         new_sock->local = nfc_llcp_local_get(local);
867         new_sock->miu = local->remote_miu;
868         new_sock->nfc_protocol = sock->nfc_protocol;
869         new_sock->dsap = ssap;
870         new_sock->target_idx = local->target_idx;
871         new_sock->parent = parent;
872         new_sock->ssap = sock->ssap;
873         if (sock->ssap < LLCP_LOCAL_NUM_SAP && sock->ssap >= LLCP_WKS_NUM_SAP) {
874                 atomic_t *client_count;
875
876                 pr_debug("reserved_ssap %d for %p\n", sock->ssap, new_sock);
877
878                 client_count =
879                         &local->local_sdp_cnt[sock->ssap - LLCP_WKS_NUM_SAP];
880
881                 atomic_inc(client_count);
882                 new_sock->reserved_ssap = sock->ssap;
883         }
884
885         nfc_llcp_parse_connection_tlv(new_sock, &skb->data[LLCP_HEADER_SIZE],
886                                       skb->len - LLCP_HEADER_SIZE);
887
888         pr_debug("new sock %p sk %p\n", new_sock, &new_sock->sk);
889
890         nfc_llcp_sock_link(&local->sockets, new_sk);
891
892         nfc_llcp_accept_enqueue(&sock->sk, new_sk);
893
894         nfc_get_device(local->dev->idx);
895
896         new_sk->sk_state = LLCP_CONNECTED;
897
898         /* Wake the listening processes */
899         parent->sk_data_ready(parent, 0);
900
901         /* Send CC */
902         nfc_llcp_send_cc(new_sock);
903
904         release_sock(&sock->sk);
905         sock_put(&sock->sk);
906
907         return;
908
909 fail:
910         /* Send DM */
911         nfc_llcp_send_dm(local, dsap, ssap, reason);
912 }
913
914 int nfc_llcp_queue_i_frames(struct nfc_llcp_sock *sock)
915 {
916         int nr_frames = 0;
917         struct nfc_llcp_local *local = sock->local;
918
919         pr_debug("Remote ready %d tx queue len %d remote rw %d",
920                  sock->remote_ready, skb_queue_len(&sock->tx_pending_queue),
921                  sock->rw);
922
923         /* Try to queue some I frames for transmission */
924         while (sock->remote_ready &&
925                skb_queue_len(&sock->tx_pending_queue) < sock->rw) {
926                 struct sk_buff *pdu;
927
928                 pdu = skb_dequeue(&sock->tx_queue);
929                 if (pdu == NULL)
930                         break;
931
932                 /* Update N(S)/N(R) */
933                 nfc_llcp_set_nrns(sock, pdu);
934
935                 skb_queue_tail(&local->tx_queue, pdu);
936                 nr_frames++;
937         }
938
939         return nr_frames;
940 }
941
942 static void nfc_llcp_recv_hdlc(struct nfc_llcp_local *local,
943                                struct sk_buff *skb)
944 {
945         struct nfc_llcp_sock *llcp_sock;
946         struct sock *sk;
947         u8 dsap, ssap, ptype, ns, nr;
948
949         ptype = nfc_llcp_ptype(skb);
950         dsap = nfc_llcp_dsap(skb);
951         ssap = nfc_llcp_ssap(skb);
952         ns = nfc_llcp_ns(skb);
953         nr = nfc_llcp_nr(skb);
954
955         pr_debug("%d %d R %d S %d\n", dsap, ssap, nr, ns);
956
957         llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
958         if (llcp_sock == NULL) {
959                 nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
960                 return;
961         }
962
963         sk = &llcp_sock->sk;
964         lock_sock(sk);
965         if (sk->sk_state == LLCP_CLOSED) {
966                 release_sock(sk);
967                 nfc_llcp_sock_put(llcp_sock);
968         }
969
970         /* Pass the payload upstream */
971         if (ptype == LLCP_PDU_I) {
972                 pr_debug("I frame, queueing on %p\n", &llcp_sock->sk);
973
974                 if (ns == llcp_sock->recv_n)
975                         llcp_sock->recv_n = (llcp_sock->recv_n + 1) % 16;
976                 else
977                         pr_err("Received out of sequence I PDU\n");
978
979                 skb_pull(skb, LLCP_HEADER_SIZE + LLCP_SEQUENCE_SIZE);
980                 if (sock_queue_rcv_skb(&llcp_sock->sk, skb)) {
981                         pr_err("receive queue is full\n");
982                         kfree_skb(skb);
983                 }
984         }
985
986         /* Remove skbs from the pending queue */
987         if (llcp_sock->send_ack_n != nr) {
988                 struct sk_buff *s, *tmp;
989                 u8 n;
990
991                 llcp_sock->send_ack_n = nr;
992
993                 /* Remove and free all skbs until ns == nr */
994                 skb_queue_walk_safe(&llcp_sock->tx_pending_queue, s, tmp) {
995                         n = nfc_llcp_ns(s);
996
997                         skb_unlink(s, &llcp_sock->tx_pending_queue);
998                         kfree_skb(s);
999
1000                         if (n == nr)
1001                                 break;
1002                 }
1003
1004                 /* Re-queue the remaining skbs for transmission */
1005                 skb_queue_reverse_walk_safe(&llcp_sock->tx_pending_queue,
1006                                             s, tmp) {
1007                         skb_unlink(s, &llcp_sock->tx_pending_queue);
1008                         skb_queue_head(&local->tx_queue, s);
1009                 }
1010         }
1011
1012         if (ptype == LLCP_PDU_RR)
1013                 llcp_sock->remote_ready = true;
1014         else if (ptype == LLCP_PDU_RNR)
1015                 llcp_sock->remote_ready = false;
1016
1017         if (nfc_llcp_queue_i_frames(llcp_sock) == 0 && ptype == LLCP_PDU_I)
1018                 nfc_llcp_send_rr(llcp_sock);
1019
1020         release_sock(sk);
1021         nfc_llcp_sock_put(llcp_sock);
1022 }
1023
1024 static void nfc_llcp_recv_disc(struct nfc_llcp_local *local,
1025                                struct sk_buff *skb)
1026 {
1027         struct nfc_llcp_sock *llcp_sock;
1028         struct sock *sk;
1029         u8 dsap, ssap;
1030
1031         dsap = nfc_llcp_dsap(skb);
1032         ssap = nfc_llcp_ssap(skb);
1033
1034         llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1035         if (llcp_sock == NULL) {
1036                 nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1037                 return;
1038         }
1039
1040         sk = &llcp_sock->sk;
1041         lock_sock(sk);
1042
1043         nfc_llcp_socket_purge(llcp_sock);
1044
1045         if (sk->sk_state == LLCP_CLOSED) {
1046                 release_sock(sk);
1047                 nfc_llcp_sock_put(llcp_sock);
1048         }
1049
1050         if (sk->sk_state == LLCP_CONNECTED) {
1051                 nfc_put_device(local->dev);
1052                 sk->sk_state = LLCP_CLOSED;
1053                 sk->sk_state_change(sk);
1054         }
1055
1056         nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_DISC);
1057
1058         release_sock(sk);
1059         nfc_llcp_sock_put(llcp_sock);
1060 }
1061
1062 static void nfc_llcp_recv_cc(struct nfc_llcp_local *local, struct sk_buff *skb)
1063 {
1064         struct nfc_llcp_sock *llcp_sock;
1065         struct sock *sk;
1066         u8 dsap, ssap;
1067
1068         dsap = nfc_llcp_dsap(skb);
1069         ssap = nfc_llcp_ssap(skb);
1070
1071         llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1072         if (llcp_sock == NULL) {
1073                 pr_err("Invalid CC\n");
1074                 nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN);
1075
1076                 return;
1077         }
1078
1079         sk = &llcp_sock->sk;
1080
1081         /* Unlink from connecting and link to the client array */
1082         nfc_llcp_sock_unlink(&local->connecting_sockets, sk);
1083         nfc_llcp_sock_link(&local->sockets, sk);
1084         llcp_sock->dsap = ssap;
1085
1086         nfc_llcp_parse_connection_tlv(llcp_sock, &skb->data[LLCP_HEADER_SIZE],
1087                                       skb->len - LLCP_HEADER_SIZE);
1088
1089         sk->sk_state = LLCP_CONNECTED;
1090         sk->sk_state_change(sk);
1091
1092         nfc_llcp_sock_put(llcp_sock);
1093 }
1094
1095 static void nfc_llcp_recv_dm(struct nfc_llcp_local *local, struct sk_buff *skb)
1096 {
1097         struct nfc_llcp_sock *llcp_sock;
1098         struct sock *sk;
1099         u8 dsap, ssap, reason;
1100
1101         dsap = nfc_llcp_dsap(skb);
1102         ssap = nfc_llcp_ssap(skb);
1103         reason = skb->data[2];
1104
1105         pr_debug("%d %d reason %d\n", ssap, dsap, reason);
1106
1107         switch (reason) {
1108         case LLCP_DM_NOBOUND:
1109         case LLCP_DM_REJ:
1110                 llcp_sock = nfc_llcp_connecting_sock_get(local, dsap);
1111                 break;
1112
1113         default:
1114                 llcp_sock = nfc_llcp_sock_get(local, dsap, ssap);
1115                 break;
1116         }
1117
1118         if (llcp_sock == NULL) {
1119                 pr_debug("Already closed\n");
1120                 return;
1121         }
1122
1123         sk = &llcp_sock->sk;
1124
1125         sk->sk_err = ENXIO;
1126         sk->sk_state = LLCP_CLOSED;
1127         sk->sk_state_change(sk);
1128
1129         nfc_llcp_sock_put(llcp_sock);
1130 }
1131
1132 static void nfc_llcp_recv_snl(struct nfc_llcp_local *local,
1133                               struct sk_buff *skb)
1134 {
1135         struct nfc_llcp_sock *llcp_sock;
1136         u8 dsap, ssap, *tlv, type, length, tid, sap;
1137         u16 tlv_len, offset;
1138         char *service_name;
1139         size_t service_name_len;
1140
1141         dsap = nfc_llcp_dsap(skb);
1142         ssap = nfc_llcp_ssap(skb);
1143
1144         pr_debug("%d %d\n", dsap, ssap);
1145
1146         if (dsap != LLCP_SAP_SDP || ssap != LLCP_SAP_SDP) {
1147                 pr_err("Wrong SNL SAP\n");
1148                 return;
1149         }
1150
1151         tlv = &skb->data[LLCP_HEADER_SIZE];
1152         tlv_len = skb->len - LLCP_HEADER_SIZE;
1153         offset = 0;
1154
1155         while (offset < tlv_len) {
1156                 type = tlv[0];
1157                 length = tlv[1];
1158
1159                 switch (type) {
1160                 case LLCP_TLV_SDREQ:
1161                         tid = tlv[2];
1162                         service_name = (char *) &tlv[3];
1163                         service_name_len = length - 1;
1164
1165                         pr_debug("Looking for %.16s\n", service_name);
1166
1167                         if (service_name_len == strlen("urn:nfc:sn:sdp") &&
1168                             !strncmp(service_name, "urn:nfc:sn:sdp",
1169                                      service_name_len)) {
1170                                 sap = 1;
1171                                 goto send_snl;
1172                         }
1173
1174                         llcp_sock = nfc_llcp_sock_from_sn(local, service_name,
1175                                                           service_name_len);
1176                         if (!llcp_sock) {
1177                                 sap = 0;
1178                                 goto send_snl;
1179                         }
1180
1181                         /*
1182                          * We found a socket but its ssap has not been reserved
1183                          * yet. We need to assign it for good and send a reply.
1184                          * The ssap will be freed when the socket is closed.
1185                          */
1186                         if (llcp_sock->ssap == LLCP_SDP_UNBOUND) {
1187                                 atomic_t *client_count;
1188
1189                                 sap = nfc_llcp_reserve_sdp_ssap(local);
1190
1191                                 pr_debug("Reserving %d\n", sap);
1192
1193                                 if (sap == LLCP_SAP_MAX) {
1194                                         sap = 0;
1195                                         goto send_snl;
1196                                 }
1197
1198                                 client_count =
1199                                         &local->local_sdp_cnt[sap -
1200                                                               LLCP_WKS_NUM_SAP];
1201
1202                                 atomic_inc(client_count);
1203
1204                                 llcp_sock->ssap = sap;
1205                                 llcp_sock->reserved_ssap = sap;
1206                         } else {
1207                                 sap = llcp_sock->ssap;
1208                         }
1209
1210                         pr_debug("%p %d\n", llcp_sock, sap);
1211
1212 send_snl:
1213                         nfc_llcp_send_snl(local, tid, sap);
1214                         break;
1215
1216                 default:
1217                         pr_err("Invalid SNL tlv value 0x%x\n", type);
1218                         break;
1219                 }
1220
1221                 offset += length + 2;
1222                 tlv += length + 2;
1223         }
1224 }
1225
1226 static void nfc_llcp_rx_work(struct work_struct *work)
1227 {
1228         struct nfc_llcp_local *local = container_of(work, struct nfc_llcp_local,
1229                                                     rx_work);
1230         u8 dsap, ssap, ptype;
1231         struct sk_buff *skb;
1232
1233         skb = local->rx_pending;
1234         if (skb == NULL) {
1235                 pr_debug("No pending SKB\n");
1236                 return;
1237         }
1238
1239         ptype = nfc_llcp_ptype(skb);
1240         dsap = nfc_llcp_dsap(skb);
1241         ssap = nfc_llcp_ssap(skb);
1242
1243         pr_debug("ptype 0x%x dsap 0x%x ssap 0x%x\n", ptype, dsap, ssap);
1244
1245         if (ptype != LLCP_PDU_SYMM)
1246                 print_hex_dump(KERN_DEBUG, "LLCP Rx: ", DUMP_PREFIX_OFFSET,
1247                                16, 1, skb->data, skb->len, true);
1248
1249         __net_timestamp(skb);
1250
1251         nfc_llcp_send_to_raw_sock(local, skb, NFC_LLCP_DIRECTION_RX);
1252
1253         switch (ptype) {
1254         case LLCP_PDU_SYMM:
1255                 pr_debug("SYMM\n");
1256                 break;
1257
1258         case LLCP_PDU_UI:
1259                 pr_debug("UI\n");
1260                 nfc_llcp_recv_ui(local, skb);
1261                 break;
1262
1263         case LLCP_PDU_CONNECT:
1264                 pr_debug("CONNECT\n");
1265                 nfc_llcp_recv_connect(local, skb);
1266                 break;
1267
1268         case LLCP_PDU_DISC:
1269                 pr_debug("DISC\n");
1270                 nfc_llcp_recv_disc(local, skb);
1271                 break;
1272
1273         case LLCP_PDU_CC:
1274                 pr_debug("CC\n");
1275                 nfc_llcp_recv_cc(local, skb);
1276                 break;
1277
1278         case LLCP_PDU_DM:
1279                 pr_debug("DM\n");
1280                 nfc_llcp_recv_dm(local, skb);
1281                 break;
1282
1283         case LLCP_PDU_SNL:
1284                 pr_debug("SNL\n");
1285                 nfc_llcp_recv_snl(local, skb);
1286                 break;
1287
1288         case LLCP_PDU_I:
1289         case LLCP_PDU_RR:
1290         case LLCP_PDU_RNR:
1291                 pr_debug("I frame\n");
1292                 nfc_llcp_recv_hdlc(local, skb);
1293                 break;
1294
1295         }
1296
1297         schedule_work(&local->tx_work);
1298         kfree_skb(local->rx_pending);
1299         local->rx_pending = NULL;
1300 }
1301
1302 void nfc_llcp_recv(void *data, struct sk_buff *skb, int err)
1303 {
1304         struct nfc_llcp_local *local = (struct nfc_llcp_local *) data;
1305
1306         pr_debug("Received an LLCP PDU\n");
1307         if (err < 0) {
1308                 pr_err("err %d\n", err);
1309                 return;
1310         }
1311
1312         local->rx_pending = skb_get(skb);
1313         del_timer(&local->link_timer);
1314         schedule_work(&local->rx_work);
1315 }
1316
1317 int nfc_llcp_data_received(struct nfc_dev *dev, struct sk_buff *skb)
1318 {
1319         struct nfc_llcp_local *local;
1320
1321         local = nfc_llcp_find_local(dev);
1322         if (local == NULL)
1323                 return -ENODEV;
1324
1325         local->rx_pending = skb_get(skb);
1326         del_timer(&local->link_timer);
1327         schedule_work(&local->rx_work);
1328
1329         return 0;
1330 }
1331
1332 void nfc_llcp_mac_is_down(struct nfc_dev *dev)
1333 {
1334         struct nfc_llcp_local *local;
1335
1336         local = nfc_llcp_find_local(dev);
1337         if (local == NULL)
1338                 return;
1339
1340         /* Close and purge all existing sockets */
1341         nfc_llcp_socket_release(local, true);
1342 }
1343
1344 void nfc_llcp_mac_is_up(struct nfc_dev *dev, u32 target_idx,
1345                         u8 comm_mode, u8 rf_mode)
1346 {
1347         struct nfc_llcp_local *local;
1348
1349         pr_debug("rf mode %d\n", rf_mode);
1350
1351         local = nfc_llcp_find_local(dev);
1352         if (local == NULL)
1353                 return;
1354
1355         local->target_idx = target_idx;
1356         local->comm_mode = comm_mode;
1357         local->rf_mode = rf_mode;
1358
1359         if (rf_mode == NFC_RF_INITIATOR) {
1360                 pr_debug("Queueing Tx work\n");
1361
1362                 schedule_work(&local->tx_work);
1363         } else {
1364                 mod_timer(&local->link_timer,
1365                           jiffies + msecs_to_jiffies(local->remote_lto));
1366         }
1367 }
1368
1369 int nfc_llcp_register_device(struct nfc_dev *ndev)
1370 {
1371         struct nfc_llcp_local *local;
1372
1373         local = kzalloc(sizeof(struct nfc_llcp_local), GFP_KERNEL);
1374         if (local == NULL)
1375                 return -ENOMEM;
1376
1377         local->dev = ndev;
1378         INIT_LIST_HEAD(&local->list);
1379         kref_init(&local->ref);
1380         mutex_init(&local->sdp_lock);
1381         init_timer(&local->link_timer);
1382         local->link_timer.data = (unsigned long) local;
1383         local->link_timer.function = nfc_llcp_symm_timer;
1384
1385         skb_queue_head_init(&local->tx_queue);
1386         INIT_WORK(&local->tx_work, nfc_llcp_tx_work);
1387
1388         local->rx_pending = NULL;
1389         INIT_WORK(&local->rx_work, nfc_llcp_rx_work);
1390
1391         INIT_WORK(&local->timeout_work, nfc_llcp_timeout_work);
1392
1393         rwlock_init(&local->sockets.lock);
1394         rwlock_init(&local->connecting_sockets.lock);
1395         rwlock_init(&local->raw_sockets.lock);
1396
1397         local->lto = 150; /* 1500 ms */
1398         local->rw = LLCP_MAX_RW;
1399         local->miux = cpu_to_be16(LLCP_MAX_MIUX);
1400
1401         nfc_llcp_build_gb(local);
1402
1403         local->remote_miu = LLCP_DEFAULT_MIU;
1404         local->remote_lto = LLCP_DEFAULT_LTO;
1405
1406         list_add(&local->list, &llcp_devices);
1407
1408         return 0;
1409 }
1410
1411 void nfc_llcp_unregister_device(struct nfc_dev *dev)
1412 {
1413         struct nfc_llcp_local *local = nfc_llcp_find_local(dev);
1414
1415         if (local == NULL) {
1416                 pr_debug("No such device\n");
1417                 return;
1418         }
1419
1420         nfc_llcp_local_put(local);
1421 }
1422
1423 int __init nfc_llcp_init(void)
1424 {
1425         INIT_LIST_HEAD(&llcp_devices);
1426
1427         return nfc_llcp_sock_init();
1428 }
1429
1430 void nfc_llcp_exit(void)
1431 {
1432         nfc_llcp_sock_exit();
1433 }