caif: remove unneeded null check in caif_connect()
[linux-2.6.git] / net / caif / caif_socket.c
1 /*
2  * Copyright (C) ST-Ericsson AB 2010
3  * Author:      Sjur Brendeland sjur.brandeland@stericsson.com
4  * License terms: GNU General Public License (GPL) version 2
5  */
6
7 #include <linux/fs.h>
8 #include <linux/init.h>
9 #include <linux/module.h>
10 #include <linux/sched.h>
11 #include <linux/spinlock.h>
12 #include <linux/mutex.h>
13 #include <linux/list.h>
14 #include <linux/wait.h>
15 #include <linux/poll.h>
16 #include <linux/tcp.h>
17 #include <linux/uaccess.h>
18 #include <linux/mutex.h>
19 #include <linux/debugfs.h>
20 #include <linux/caif/caif_socket.h>
21 #include <asm/atomic.h>
22 #include <net/sock.h>
23 #include <net/tcp_states.h>
24 #include <net/caif/caif_layer.h>
25 #include <net/caif/caif_dev.h>
26 #include <net/caif/cfpkt.h>
27
28 MODULE_LICENSE("GPL");
29 MODULE_ALIAS_NETPROTO(AF_CAIF);
30
31 #define CAIF_DEF_SNDBUF (CAIF_MAX_PAYLOAD_SIZE*10)
32 #define CAIF_DEF_RCVBUF (CAIF_MAX_PAYLOAD_SIZE*100)
33
34 /*
35  * CAIF state is re-using the TCP socket states.
36  * caif_states stored in sk_state reflect the state as reported by
37  * the CAIF stack, while sk_socket->state is the state of the socket.
38  */
39 enum caif_states {
40         CAIF_CONNECTED          = TCP_ESTABLISHED,
41         CAIF_CONNECTING = TCP_SYN_SENT,
42         CAIF_DISCONNECTED       = TCP_CLOSE
43 };
44
45 #define TX_FLOW_ON_BIT  1
46 #define RX_FLOW_ON_BIT  2
47
48 static struct dentry *debugfsdir;
49
50 #ifdef CONFIG_DEBUG_FS
51 struct debug_fs_counter {
52         atomic_t caif_nr_socks;
53         atomic_t num_connect_req;
54         atomic_t num_connect_resp;
55         atomic_t num_connect_fail_resp;
56         atomic_t num_disconnect;
57         atomic_t num_remote_shutdown_ind;
58         atomic_t num_tx_flow_off_ind;
59         atomic_t num_tx_flow_on_ind;
60         atomic_t num_rx_flow_off;
61         atomic_t num_rx_flow_on;
62 };
63 static struct debug_fs_counter cnt;
64 #define dbfs_atomic_inc(v) atomic_inc(v)
65 #define dbfs_atomic_dec(v) atomic_dec(v)
66 #else
67 #define dbfs_atomic_inc(v)
68 #define dbfs_atomic_dec(v)
69 #endif
70
71 struct caifsock {
72         struct sock sk; /* must be first member */
73         struct cflayer layer;
74         char name[CAIF_LAYER_NAME_SZ]; /* Used for debugging */
75         u32 flow_state;
76         struct caif_connect_request conn_req;
77         struct mutex readlock;
78         struct dentry *debugfs_socket_dir;
79 };
80
81 static int rx_flow_is_on(struct caifsock *cf_sk)
82 {
83         return test_bit(RX_FLOW_ON_BIT,
84                         (void *) &cf_sk->flow_state);
85 }
86
87 static int tx_flow_is_on(struct caifsock *cf_sk)
88 {
89         return test_bit(TX_FLOW_ON_BIT,
90                         (void *) &cf_sk->flow_state);
91 }
92
93 static void set_rx_flow_off(struct caifsock *cf_sk)
94 {
95          clear_bit(RX_FLOW_ON_BIT,
96                  (void *) &cf_sk->flow_state);
97 }
98
99 static void set_rx_flow_on(struct caifsock *cf_sk)
100 {
101          set_bit(RX_FLOW_ON_BIT,
102                         (void *) &cf_sk->flow_state);
103 }
104
105 static void set_tx_flow_off(struct caifsock *cf_sk)
106 {
107          clear_bit(TX_FLOW_ON_BIT,
108                 (void *) &cf_sk->flow_state);
109 }
110
111 static void set_tx_flow_on(struct caifsock *cf_sk)
112 {
113          set_bit(TX_FLOW_ON_BIT,
114                 (void *) &cf_sk->flow_state);
115 }
116
117 static void caif_read_lock(struct sock *sk)
118 {
119         struct caifsock *cf_sk;
120         cf_sk = container_of(sk, struct caifsock, sk);
121         mutex_lock(&cf_sk->readlock);
122 }
123
124 static void caif_read_unlock(struct sock *sk)
125 {
126         struct caifsock *cf_sk;
127         cf_sk = container_of(sk, struct caifsock, sk);
128         mutex_unlock(&cf_sk->readlock);
129 }
130
131 static int sk_rcvbuf_lowwater(struct caifsock *cf_sk)
132 {
133         /* A quarter of full buffer is used a low water mark */
134         return cf_sk->sk.sk_rcvbuf / 4;
135 }
136
137 static void caif_flow_ctrl(struct sock *sk, int mode)
138 {
139         struct caifsock *cf_sk;
140         cf_sk = container_of(sk, struct caifsock, sk);
141         if (cf_sk->layer.dn && cf_sk->layer.dn->modemcmd)
142                 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, mode);
143 }
144
145 /*
146  * Copied from sock.c:sock_queue_rcv_skb(), but changed so packets are
147  * not dropped, but CAIF is sending flow off instead.
148  */
149 static int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
150 {
151         int err;
152         int skb_len;
153         unsigned long flags;
154         struct sk_buff_head *list = &sk->sk_receive_queue;
155         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
156
157         if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
158                 (unsigned)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) {
159                 trace_printk("CAIF: %s():"
160                         " sending flow OFF (queue len = %d %d)\n",
161                         __func__,
162                         atomic_read(&cf_sk->sk.sk_rmem_alloc),
163                         sk_rcvbuf_lowwater(cf_sk));
164                 set_rx_flow_off(cf_sk);
165                 dbfs_atomic_inc(&cnt.num_rx_flow_off);
166                 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
167         }
168
169         err = sk_filter(sk, skb);
170         if (err)
171                 return err;
172         if (!sk_rmem_schedule(sk, skb->truesize) && rx_flow_is_on(cf_sk)) {
173                 set_rx_flow_off(cf_sk);
174                 trace_printk("CAIF: %s():"
175                         " sending flow OFF due to rmem_schedule\n",
176                         __func__);
177                 dbfs_atomic_inc(&cnt.num_rx_flow_off);
178                 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
179         }
180         skb->dev = NULL;
181         skb_set_owner_r(skb, sk);
182         /* Cache the SKB length before we tack it onto the receive
183          * queue. Once it is added it no longer belongs to us and
184          * may be freed by other threads of control pulling packets
185          * from the queue.
186          */
187         skb_len = skb->len;
188         spin_lock_irqsave(&list->lock, flags);
189         if (!sock_flag(sk, SOCK_DEAD))
190                 __skb_queue_tail(list, skb);
191         spin_unlock_irqrestore(&list->lock, flags);
192
193         if (!sock_flag(sk, SOCK_DEAD))
194                 sk->sk_data_ready(sk, skb_len);
195         else
196                 kfree_skb(skb);
197         return 0;
198 }
199
200 /* Packet Receive Callback function called from CAIF Stack */
201 static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
202 {
203         struct caifsock *cf_sk;
204         struct sk_buff *skb;
205
206         cf_sk = container_of(layr, struct caifsock, layer);
207         skb = cfpkt_tonative(pkt);
208
209         if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) {
210                 cfpkt_destroy(pkt);
211                 return 0;
212         }
213         caif_queue_rcv_skb(&cf_sk->sk, skb);
214         return 0;
215 }
216
217 /* Packet Control Callback function called from CAIF */
218 static void caif_ctrl_cb(struct cflayer *layr,
219                                 enum caif_ctrlcmd flow,
220                                 int phyid)
221 {
222         struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
223         switch (flow) {
224         case CAIF_CTRLCMD_FLOW_ON_IND:
225                 /* OK from modem to start sending again */
226                 dbfs_atomic_inc(&cnt.num_tx_flow_on_ind);
227                 set_tx_flow_on(cf_sk);
228                 cf_sk->sk.sk_state_change(&cf_sk->sk);
229                 break;
230
231         case CAIF_CTRLCMD_FLOW_OFF_IND:
232                 /* Modem asks us to shut up */
233                 dbfs_atomic_inc(&cnt.num_tx_flow_off_ind);
234                 set_tx_flow_off(cf_sk);
235                 cf_sk->sk.sk_state_change(&cf_sk->sk);
236                 break;
237
238         case CAIF_CTRLCMD_INIT_RSP:
239                 /* We're now connected */
240                 dbfs_atomic_inc(&cnt.num_connect_resp);
241                 cf_sk->sk.sk_state = CAIF_CONNECTED;
242                 set_tx_flow_on(cf_sk);
243                 cf_sk->sk.sk_state_change(&cf_sk->sk);
244                 break;
245
246         case CAIF_CTRLCMD_DEINIT_RSP:
247                 /* We're now disconnected */
248                 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
249                 cf_sk->sk.sk_state_change(&cf_sk->sk);
250                 cfcnfg_release_adap_layer(&cf_sk->layer);
251                 break;
252
253         case CAIF_CTRLCMD_INIT_FAIL_RSP:
254                 /* Connect request failed */
255                 dbfs_atomic_inc(&cnt.num_connect_fail_resp);
256                 cf_sk->sk.sk_err = ECONNREFUSED;
257                 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
258                 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
259                 /*
260                  * Socket "standards" seems to require POLLOUT to
261                  * be set at connect failure.
262                  */
263                 set_tx_flow_on(cf_sk);
264                 cf_sk->sk.sk_state_change(&cf_sk->sk);
265                 break;
266
267         case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
268                 /* Modem has closed this connection, or device is down. */
269                 dbfs_atomic_inc(&cnt.num_remote_shutdown_ind);
270                 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
271                 cf_sk->sk.sk_err = ECONNRESET;
272                 set_rx_flow_on(cf_sk);
273                 cf_sk->sk.sk_error_report(&cf_sk->sk);
274                 break;
275
276         default:
277                 pr_debug("CAIF: %s(): Unexpected flow command %d\n",
278                                 __func__, flow);
279         }
280 }
281
282 static void caif_check_flow_release(struct sock *sk)
283 {
284         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
285
286         if (rx_flow_is_on(cf_sk))
287                 return;
288
289         if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) {
290                         dbfs_atomic_inc(&cnt.num_rx_flow_on);
291                         set_rx_flow_on(cf_sk);
292                         caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ);
293         }
294 }
295
296 /*
297  * Copied from unix_dgram_recvmsg, but removed credit checks,
298  * changed locking, address handling and added MSG_TRUNC.
299  */
300 static int caif_seqpkt_recvmsg(struct kiocb *iocb, struct socket *sock,
301                                 struct msghdr *m, size_t len, int flags)
302
303 {
304         struct sock *sk = sock->sk;
305         struct sk_buff *skb;
306         int ret;
307         int copylen;
308
309         ret = -EOPNOTSUPP;
310         if (m->msg_flags&MSG_OOB)
311                 goto read_error;
312
313         skb = skb_recv_datagram(sk, flags, 0 , &ret);
314         if (!skb)
315                 goto read_error;
316         copylen = skb->len;
317         if (len < copylen) {
318                 m->msg_flags |= MSG_TRUNC;
319                 copylen = len;
320         }
321
322         ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, copylen);
323         if (ret)
324                 goto out_free;
325
326         ret = (flags & MSG_TRUNC) ? skb->len : copylen;
327 out_free:
328         skb_free_datagram(sk, skb);
329         caif_check_flow_release(sk);
330         return ret;
331
332 read_error:
333         return ret;
334 }
335
336
337 /* Copied from unix_stream_wait_data, identical except for lock call. */
338 static long caif_stream_data_wait(struct sock *sk, long timeo)
339 {
340         DEFINE_WAIT(wait);
341         lock_sock(sk);
342
343         for (;;) {
344                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
345
346                 if (!skb_queue_empty(&sk->sk_receive_queue) ||
347                         sk->sk_err ||
348                         sk->sk_state != CAIF_CONNECTED ||
349                         sock_flag(sk, SOCK_DEAD) ||
350                         (sk->sk_shutdown & RCV_SHUTDOWN) ||
351                         signal_pending(current) ||
352                         !timeo)
353                         break;
354
355                 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
356                 release_sock(sk);
357                 timeo = schedule_timeout(timeo);
358                 lock_sock(sk);
359                 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
360         }
361
362         finish_wait(sk_sleep(sk), &wait);
363         release_sock(sk);
364         return timeo;
365 }
366
367
368 /*
369  * Copied from unix_stream_recvmsg, but removed credit checks,
370  * changed locking calls, changed address handling.
371  */
372 static int caif_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
373                                 struct msghdr *msg, size_t size,
374                                 int flags)
375 {
376         struct sock *sk = sock->sk;
377         int copied = 0;
378         int target;
379         int err = 0;
380         long timeo;
381
382         err = -EOPNOTSUPP;
383         if (flags&MSG_OOB)
384                 goto out;
385
386         msg->msg_namelen = 0;
387
388         /*
389          * Lock the socket to prevent queue disordering
390          * while sleeps in memcpy_tomsg
391          */
392         err = -EAGAIN;
393         if (sk->sk_state == CAIF_CONNECTING)
394                 goto out;
395
396         caif_read_lock(sk);
397         target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
398         timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
399
400         do {
401                 int chunk;
402                 struct sk_buff *skb;
403
404                 lock_sock(sk);
405                 skb = skb_dequeue(&sk->sk_receive_queue);
406                 caif_check_flow_release(sk);
407
408                 if (skb == NULL) {
409                         if (copied >= target)
410                                 goto unlock;
411                         /*
412                          *      POSIX 1003.1g mandates this order.
413                          */
414                         err = sock_error(sk);
415                         if (err)
416                                 goto unlock;
417                         err = -ECONNRESET;
418                         if (sk->sk_shutdown & RCV_SHUTDOWN)
419                                 goto unlock;
420
421                         err = -EPIPE;
422                         if (sk->sk_state != CAIF_CONNECTED)
423                                 goto unlock;
424                         if (sock_flag(sk, SOCK_DEAD))
425                                 goto unlock;
426
427                         release_sock(sk);
428
429                         err = -EAGAIN;
430                         if (!timeo)
431                                 break;
432
433                         caif_read_unlock(sk);
434
435                         timeo = caif_stream_data_wait(sk, timeo);
436
437                         if (signal_pending(current)) {
438                                 err = sock_intr_errno(timeo);
439                                 goto out;
440                         }
441                         caif_read_lock(sk);
442                         continue;
443 unlock:
444                         release_sock(sk);
445                         break;
446                 }
447                 release_sock(sk);
448                 chunk = min_t(unsigned int, skb->len, size);
449                 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
450                         skb_queue_head(&sk->sk_receive_queue, skb);
451                         if (copied == 0)
452                                 copied = -EFAULT;
453                         break;
454                 }
455                 copied += chunk;
456                 size -= chunk;
457
458                 /* Mark read part of skb as used */
459                 if (!(flags & MSG_PEEK)) {
460                         skb_pull(skb, chunk);
461
462                         /* put the skb back if we didn't use it up. */
463                         if (skb->len) {
464                                 skb_queue_head(&sk->sk_receive_queue, skb);
465                                 break;
466                         }
467                         kfree_skb(skb);
468
469                 } else {
470                         /*
471                          * It is questionable, see note in unix_dgram_recvmsg.
472                          */
473                         /* put message back and return */
474                         skb_queue_head(&sk->sk_receive_queue, skb);
475                         break;
476                 }
477         } while (size);
478         caif_read_unlock(sk);
479
480 out:
481         return copied ? : err;
482 }
483
484 /*
485  * Copied from sock.c:sock_wait_for_wmem, but change to wait for
486  * CAIF flow-on and sock_writable.
487  */
488 static long caif_wait_for_flow_on(struct caifsock *cf_sk,
489                                 int wait_writeable, long timeo, int *err)
490 {
491         struct sock *sk = &cf_sk->sk;
492         DEFINE_WAIT(wait);
493         for (;;) {
494                 *err = 0;
495                 if (tx_flow_is_on(cf_sk) &&
496                         (!wait_writeable || sock_writeable(&cf_sk->sk)))
497                         break;
498                 *err = -ETIMEDOUT;
499                 if (!timeo)
500                         break;
501                 *err = -ERESTARTSYS;
502                 if (signal_pending(current))
503                         break;
504                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
505                 *err = -ECONNRESET;
506                 if (sk->sk_shutdown & SHUTDOWN_MASK)
507                         break;
508                 *err = -sk->sk_err;
509                 if (sk->sk_err)
510                         break;
511                 *err = -EPIPE;
512                 if (cf_sk->sk.sk_state != CAIF_CONNECTED)
513                         break;
514                 timeo = schedule_timeout(timeo);
515         }
516         finish_wait(sk_sleep(sk), &wait);
517         return timeo;
518 }
519
520 /*
521  * Transmit a SKB. The device may temporarily request re-transmission
522  * by returning EAGAIN.
523  */
524 static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk,
525                         int noblock, long timeo)
526 {
527         struct cfpkt *pkt;
528         int ret, loopcnt = 0;
529
530         pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb);
531         memset(cfpkt_info(pkt), 0, sizeof(struct caif_payload_info));
532         do {
533
534                 ret = -ETIMEDOUT;
535
536                 /* Slight paranoia, probably not needed. */
537                 if (unlikely(loopcnt++ > 1000)) {
538                         pr_warning("CAIF: %s(): transmit retries failed,"
539                                 " error = %d\n", __func__, ret);
540                         break;
541                 }
542
543                 if (cf_sk->layer.dn != NULL)
544                         ret = cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
545                 if (likely(ret >= 0))
546                         break;
547                 /* if transmit return -EAGAIN, then retry */
548                 if (noblock && ret == -EAGAIN)
549                         break;
550                 timeo = caif_wait_for_flow_on(cf_sk, 0, timeo, &ret);
551                 if (signal_pending(current)) {
552                         ret = sock_intr_errno(timeo);
553                         break;
554                 }
555                 if (ret)
556                         break;
557                 if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
558                         sock_flag(&cf_sk->sk, SOCK_DEAD) ||
559                         (cf_sk->sk.sk_shutdown & RCV_SHUTDOWN)) {
560                         ret = -EPIPE;
561                         cf_sk->sk.sk_err = EPIPE;
562                         break;
563                 }
564         } while (ret == -EAGAIN);
565         return ret;
566 }
567
568 /* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
569 static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock,
570                         struct msghdr *msg, size_t len)
571 {
572         struct sock *sk = sock->sk;
573         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
574         int buffer_size;
575         int ret = 0;
576         struct sk_buff *skb = NULL;
577         int noblock;
578         long timeo;
579         caif_assert(cf_sk);
580         ret = sock_error(sk);
581         if (ret)
582                 goto err;
583
584         ret = -EOPNOTSUPP;
585         if (msg->msg_flags&MSG_OOB)
586                 goto err;
587
588         ret = -EOPNOTSUPP;
589         if (msg->msg_namelen)
590                 goto err;
591
592         ret = -EINVAL;
593         if (unlikely(msg->msg_iov->iov_base == NULL))
594                 goto err;
595         noblock = msg->msg_flags & MSG_DONTWAIT;
596
597         buffer_size = len + CAIF_NEEDED_HEADROOM + CAIF_NEEDED_TAILROOM;
598
599         ret = -EMSGSIZE;
600         if (buffer_size > CAIF_MAX_PAYLOAD_SIZE)
601                 goto err;
602
603         timeo = sock_sndtimeo(sk, noblock);
604         timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
605                                 1, timeo, &ret);
606
607         ret = -EPIPE;
608         if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
609                 sock_flag(sk, SOCK_DEAD) ||
610                 (sk->sk_shutdown & RCV_SHUTDOWN))
611                 goto err;
612
613         ret = -ENOMEM;
614         skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
615         if (!skb)
616                 goto err;
617         skb_reserve(skb, CAIF_NEEDED_HEADROOM);
618
619         ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
620
621         if (ret)
622                 goto err;
623         ret = transmit_skb(skb, cf_sk, noblock, timeo);
624         if (ret < 0)
625                 goto err;
626         return len;
627 err:
628         kfree_skb(skb);
629         return ret;
630 }
631
632 /*
633  * Copied from unix_stream_sendmsg and adapted to CAIF:
634  * Changed removed permission handling and added waiting for flow on
635  * and other minor adaptations.
636  */
637 static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
638                                 struct msghdr *msg, size_t len)
639 {
640         struct sock *sk = sock->sk;
641         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
642         int err, size;
643         struct sk_buff *skb;
644         int sent = 0;
645         long timeo;
646
647         err = -EOPNOTSUPP;
648
649         if (unlikely(msg->msg_flags&MSG_OOB))
650                 goto out_err;
651
652         if (unlikely(msg->msg_namelen))
653                 goto out_err;
654
655         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
656         timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
657
658         if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
659                 goto pipe_err;
660
661         while (sent < len) {
662
663                 size = len-sent;
664
665                 if (size > CAIF_MAX_PAYLOAD_SIZE)
666                         size = CAIF_MAX_PAYLOAD_SIZE;
667
668                 /* If size is more than half of sndbuf, chop up message */
669                 if (size > ((sk->sk_sndbuf >> 1) - 64))
670                         size = (sk->sk_sndbuf >> 1) - 64;
671
672                 if (size > SKB_MAX_ALLOC)
673                         size = SKB_MAX_ALLOC;
674
675                 skb = sock_alloc_send_skb(sk,
676                                         size + CAIF_NEEDED_HEADROOM
677                                         + CAIF_NEEDED_TAILROOM,
678                                         msg->msg_flags&MSG_DONTWAIT,
679                                         &err);
680                 if (skb == NULL)
681                         goto out_err;
682
683                 skb_reserve(skb, CAIF_NEEDED_HEADROOM);
684                 /*
685                  *      If you pass two values to the sock_alloc_send_skb
686                  *      it tries to grab the large buffer with GFP_NOFS
687                  *      (which can fail easily), and if it fails grab the
688                  *      fallback size buffer which is under a page and will
689                  *      succeed. [Alan]
690                  */
691                 size = min_t(int, size, skb_tailroom(skb));
692
693                 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
694                 if (err) {
695                         kfree_skb(skb);
696                         goto out_err;
697                 }
698                 err = transmit_skb(skb, cf_sk,
699                                 msg->msg_flags&MSG_DONTWAIT, timeo);
700                 if (err < 0) {
701                         kfree_skb(skb);
702                         goto pipe_err;
703                 }
704                 sent += size;
705         }
706
707         return sent;
708
709 pipe_err:
710         if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
711                 send_sig(SIGPIPE, current, 0);
712         err = -EPIPE;
713 out_err:
714         return sent ? : err;
715 }
716
717 static int setsockopt(struct socket *sock,
718                         int lvl, int opt, char __user *ov, unsigned int ol)
719 {
720         struct sock *sk = sock->sk;
721         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
722         int prio, linksel;
723         struct ifreq ifreq;
724
725         if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
726                 return -ENOPROTOOPT;
727
728         switch (opt) {
729         case CAIFSO_LINK_SELECT:
730                 if (ol < sizeof(int))
731                         return -EINVAL;
732                 if (lvl != SOL_CAIF)
733                         goto bad_sol;
734                 if (copy_from_user(&linksel, ov, sizeof(int)))
735                         return -EINVAL;
736                 lock_sock(&(cf_sk->sk));
737                 cf_sk->conn_req.link_selector = linksel;
738                 release_sock(&cf_sk->sk);
739                 return 0;
740
741         case SO_PRIORITY:
742                 if (lvl != SOL_SOCKET)
743                         goto bad_sol;
744                 if (ol < sizeof(int))
745                         return -EINVAL;
746                 if (copy_from_user(&prio, ov, sizeof(int)))
747                         return -EINVAL;
748                 lock_sock(&(cf_sk->sk));
749                 cf_sk->conn_req.priority = prio;
750                 release_sock(&cf_sk->sk);
751                 return 0;
752
753         case SO_BINDTODEVICE:
754                 if (lvl != SOL_SOCKET)
755                         goto bad_sol;
756                 if (ol < sizeof(struct ifreq))
757                         return -EINVAL;
758                 if (copy_from_user(&ifreq, ov, sizeof(ifreq)))
759                         return -EFAULT;
760                 lock_sock(&(cf_sk->sk));
761                 strncpy(cf_sk->conn_req.link_name, ifreq.ifr_name,
762                         sizeof(cf_sk->conn_req.link_name));
763                 cf_sk->conn_req.link_name
764                         [sizeof(cf_sk->conn_req.link_name)-1] = 0;
765                 release_sock(&cf_sk->sk);
766                 return 0;
767
768         case CAIFSO_REQ_PARAM:
769                 if (lvl != SOL_CAIF)
770                         goto bad_sol;
771                 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
772                         return -ENOPROTOOPT;
773                 lock_sock(&(cf_sk->sk));
774                 cf_sk->conn_req.param.size = ol;
775                 if (ol > sizeof(cf_sk->conn_req.param.data) ||
776                         copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) {
777                         release_sock(&cf_sk->sk);
778                         return -EINVAL;
779                 }
780                 release_sock(&cf_sk->sk);
781                 return 0;
782
783         default:
784                 return -ENOPROTOOPT;
785         }
786
787         return 0;
788 bad_sol:
789         return -ENOPROTOOPT;
790
791 }
792
793 /*
794  * caif_connect() - Connect a CAIF Socket
795  * Copied and modified af_irda.c:irda_connect().
796  *
797  * Note : by consulting "errno", the user space caller may learn the cause
798  * of the failure. Most of them are visible in the function, others may come
799  * from subroutines called and are listed here :
800  *  o -EAFNOSUPPORT: bad socket family or type.
801  *  o -ESOCKTNOSUPPORT: bad socket type or protocol
802  *  o -EINVAL: bad socket address, or CAIF link type
803  *  o -ECONNREFUSED: remote end refused the connection.
804  *  o -EINPROGRESS: connect request sent but timed out (or non-blocking)
805  *  o -EISCONN: already connected.
806  *  o -ETIMEDOUT: Connection timed out (send timeout)
807  *  o -ENODEV: No link layer to send request
808  *  o -ECONNRESET: Received Shutdown indication or lost link layer
809  *  o -ENOMEM: Out of memory
810  *
811  *  State Strategy:
812  *  o sk_state: holds the CAIF_* protocol state, it's updated by
813  *      caif_ctrl_cb.
814  *  o sock->state: holds the SS_* socket state and is updated by connect and
815  *      disconnect.
816  */
817 static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
818                         int addr_len, int flags)
819 {
820         struct sock *sk = sock->sk;
821         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
822         long timeo;
823         int err;
824         lock_sock(sk);
825
826         err = -EAFNOSUPPORT;
827         if (uaddr->sa_family != AF_CAIF)
828                 goto out;
829
830         err = -ESOCKTNOSUPPORT;
831         if (unlikely(!(sk->sk_type == SOCK_STREAM &&
832                        cf_sk->sk.sk_protocol == CAIFPROTO_AT) &&
833                        sk->sk_type != SOCK_SEQPACKET))
834                 goto out;
835         switch (sock->state) {
836         case SS_UNCONNECTED:
837                 /* Normal case, a fresh connect */
838                 caif_assert(sk->sk_state == CAIF_DISCONNECTED);
839                 break;
840         case SS_CONNECTING:
841                 switch (sk->sk_state) {
842                 case CAIF_CONNECTED:
843                         sock->state = SS_CONNECTED;
844                         err = -EISCONN;
845                         goto out;
846                 case CAIF_DISCONNECTED:
847                         /* Reconnect allowed */
848                         break;
849                 case CAIF_CONNECTING:
850                         err = -EALREADY;
851                         if (flags & O_NONBLOCK)
852                                 goto out;
853                         goto wait_connect;
854                 }
855                 break;
856         case SS_CONNECTED:
857                 caif_assert(sk->sk_state == CAIF_CONNECTED ||
858                                 sk->sk_state == CAIF_DISCONNECTED);
859                 if (sk->sk_shutdown & SHUTDOWN_MASK) {
860                         /* Allow re-connect after SHUTDOWN_IND */
861                         caif_disconnect_client(&cf_sk->layer);
862                         break;
863                 }
864                 /* No reconnect on a seqpacket socket */
865                 err = -EISCONN;
866                 goto out;
867         case SS_DISCONNECTING:
868         case SS_FREE:
869                 caif_assert(1); /*Should never happen */
870                 break;
871         }
872         sk->sk_state = CAIF_DISCONNECTED;
873         sock->state = SS_UNCONNECTED;
874         sk_stream_kill_queues(&cf_sk->sk);
875
876         err = -EINVAL;
877         if (addr_len != sizeof(struct sockaddr_caif))
878                 goto out;
879
880         memcpy(&cf_sk->conn_req.sockaddr, uaddr,
881                 sizeof(struct sockaddr_caif));
882
883         /* Move to connecting socket, start sending Connect Requests */
884         sock->state = SS_CONNECTING;
885         sk->sk_state = CAIF_CONNECTING;
886
887         dbfs_atomic_inc(&cnt.num_connect_req);
888         cf_sk->layer.receive = caif_sktrecv_cb;
889         err = caif_connect_client(&cf_sk->conn_req,
890                                 &cf_sk->layer);
891         if (err < 0) {
892                 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
893                 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
894                 goto out;
895         }
896
897         err = -EINPROGRESS;
898 wait_connect:
899
900         if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
901                 goto out;
902
903         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
904
905         release_sock(sk);
906         err = -ERESTARTSYS;
907         timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
908                         sk->sk_state != CAIF_CONNECTING,
909                         timeo);
910         lock_sock(sk);
911         if (timeo < 0)
912                 goto out; /* -ERESTARTSYS */
913
914         err = -ETIMEDOUT;
915         if (timeo == 0 && sk->sk_state != CAIF_CONNECTED)
916                 goto out;
917         if (sk->sk_state != CAIF_CONNECTED) {
918                 sock->state = SS_UNCONNECTED;
919                 err = sock_error(sk);
920                 if (!err)
921                         err = -ECONNREFUSED;
922                 goto out;
923         }
924         sock->state = SS_CONNECTED;
925         err = 0;
926 out:
927         release_sock(sk);
928         return err;
929 }
930
931 /*
932  * caif_release() - Disconnect a CAIF Socket
933  * Copied and modified af_irda.c:irda_release().
934  */
935 static int caif_release(struct socket *sock)
936 {
937         struct sock *sk = sock->sk;
938         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
939         int res = 0;
940
941         if (!sk)
942                 return 0;
943
944         set_tx_flow_off(cf_sk);
945
946         /*
947          * Ensure that packets are not queued after this point in time.
948          * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
949          * this ensures no packets when sock is dead.
950          */
951         spin_lock(&sk->sk_receive_queue.lock);
952         sock_set_flag(sk, SOCK_DEAD);
953         spin_unlock(&sk->sk_receive_queue.lock);
954         sock->sk = NULL;
955
956         dbfs_atomic_inc(&cnt.num_disconnect);
957
958         if (cf_sk->debugfs_socket_dir != NULL)
959                 debugfs_remove_recursive(cf_sk->debugfs_socket_dir);
960
961         lock_sock(&(cf_sk->sk));
962         sk->sk_state = CAIF_DISCONNECTED;
963         sk->sk_shutdown = SHUTDOWN_MASK;
964
965         if (cf_sk->sk.sk_socket->state == SS_CONNECTED ||
966                 cf_sk->sk.sk_socket->state == SS_CONNECTING)
967                 res = caif_disconnect_client(&cf_sk->layer);
968
969         cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
970         wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP);
971
972         sock_orphan(sk);
973         cf_sk->layer.dn = NULL;
974         sk_stream_kill_queues(&cf_sk->sk);
975         release_sock(sk);
976         sock_put(sk);
977         return res;
978 }
979
980 /* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */
981 static unsigned int caif_poll(struct file *file,
982                                 struct socket *sock, poll_table *wait)
983 {
984         struct sock *sk = sock->sk;
985         unsigned int mask;
986         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
987
988         sock_poll_wait(file, sk_sleep(sk), wait);
989         mask = 0;
990
991         /* exceptional events? */
992         if (sk->sk_err)
993                 mask |= POLLERR;
994         if (sk->sk_shutdown == SHUTDOWN_MASK)
995                 mask |= POLLHUP;
996         if (sk->sk_shutdown & RCV_SHUTDOWN)
997                 mask |= POLLRDHUP;
998
999         /* readable? */
1000         if (!skb_queue_empty(&sk->sk_receive_queue) ||
1001                 (sk->sk_shutdown & RCV_SHUTDOWN))
1002                 mask |= POLLIN | POLLRDNORM;
1003
1004         /*
1005          * we set writable also when the other side has shut down the
1006          * connection. This prevents stuck sockets.
1007          */
1008         if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
1009                 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1010
1011         return mask;
1012 }
1013
1014 static const struct proto_ops caif_seqpacket_ops = {
1015         .family = PF_CAIF,
1016         .owner = THIS_MODULE,
1017         .release = caif_release,
1018         .bind = sock_no_bind,
1019         .connect = caif_connect,
1020         .socketpair = sock_no_socketpair,
1021         .accept = sock_no_accept,
1022         .getname = sock_no_getname,
1023         .poll = caif_poll,
1024         .ioctl = sock_no_ioctl,
1025         .listen = sock_no_listen,
1026         .shutdown = sock_no_shutdown,
1027         .setsockopt = setsockopt,
1028         .getsockopt = sock_no_getsockopt,
1029         .sendmsg = caif_seqpkt_sendmsg,
1030         .recvmsg = caif_seqpkt_recvmsg,
1031         .mmap = sock_no_mmap,
1032         .sendpage = sock_no_sendpage,
1033 };
1034
1035 static const struct proto_ops caif_stream_ops = {
1036         .family = PF_CAIF,
1037         .owner = THIS_MODULE,
1038         .release = caif_release,
1039         .bind = sock_no_bind,
1040         .connect = caif_connect,
1041         .socketpair = sock_no_socketpair,
1042         .accept = sock_no_accept,
1043         .getname = sock_no_getname,
1044         .poll = caif_poll,
1045         .ioctl = sock_no_ioctl,
1046         .listen = sock_no_listen,
1047         .shutdown = sock_no_shutdown,
1048         .setsockopt = setsockopt,
1049         .getsockopt = sock_no_getsockopt,
1050         .sendmsg = caif_stream_sendmsg,
1051         .recvmsg = caif_stream_recvmsg,
1052         .mmap = sock_no_mmap,
1053         .sendpage = sock_no_sendpage,
1054 };
1055
1056 /* This function is called when a socket is finally destroyed. */
1057 static void caif_sock_destructor(struct sock *sk)
1058 {
1059         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1060         caif_assert(!atomic_read(&sk->sk_wmem_alloc));
1061         caif_assert(sk_unhashed(sk));
1062         caif_assert(!sk->sk_socket);
1063         if (!sock_flag(sk, SOCK_DEAD)) {
1064                 pr_info("Attempt to release alive CAIF socket: %p\n", sk);
1065                 return;
1066         }
1067         sk_stream_kill_queues(&cf_sk->sk);
1068         dbfs_atomic_dec(&cnt.caif_nr_socks);
1069 }
1070
1071 static int caif_create(struct net *net, struct socket *sock, int protocol,
1072                         int kern)
1073 {
1074         struct sock *sk = NULL;
1075         struct caifsock *cf_sk = NULL;
1076         static struct proto prot = {.name = "PF_CAIF",
1077                 .owner = THIS_MODULE,
1078                 .obj_size = sizeof(struct caifsock),
1079         };
1080
1081         if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
1082                 return -EPERM;
1083         /*
1084          * The sock->type specifies the socket type to use.
1085          * The CAIF socket is a packet stream in the sense
1086          * that it is packet based. CAIF trusts the reliability
1087          * of the link, no resending is implemented.
1088          */
1089         if (sock->type == SOCK_SEQPACKET)
1090                 sock->ops = &caif_seqpacket_ops;
1091         else if (sock->type == SOCK_STREAM)
1092                 sock->ops = &caif_stream_ops;
1093         else
1094                 return -ESOCKTNOSUPPORT;
1095
1096         if (protocol < 0 || protocol >= CAIFPROTO_MAX)
1097                 return -EPROTONOSUPPORT;
1098         /*
1099          * Set the socket state to unconnected.  The socket state
1100          * is really not used at all in the net/core or socket.c but the
1101          * initialization makes sure that sock->state is not uninitialized.
1102          */
1103         sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot);
1104         if (!sk)
1105                 return -ENOMEM;
1106
1107         cf_sk = container_of(sk, struct caifsock, sk);
1108
1109         /* Store the protocol */
1110         sk->sk_protocol = (unsigned char) protocol;
1111
1112         /* Sendbuf dictates the amount of outbound packets not yet sent */
1113         sk->sk_sndbuf = CAIF_DEF_SNDBUF;
1114         sk->sk_rcvbuf = CAIF_DEF_RCVBUF;
1115
1116         /*
1117          * Lock in order to try to stop someone from opening the socket
1118          * too early.
1119          */
1120         lock_sock(&(cf_sk->sk));
1121
1122         /* Initialize the nozero default sock structure data. */
1123         sock_init_data(sock, sk);
1124         sk->sk_destruct = caif_sock_destructor;
1125
1126         mutex_init(&cf_sk->readlock); /* single task reading lock */
1127         cf_sk->layer.ctrlcmd = caif_ctrl_cb;
1128         cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
1129         cf_sk->sk.sk_state = CAIF_DISCONNECTED;
1130
1131         set_tx_flow_off(cf_sk);
1132         set_rx_flow_on(cf_sk);
1133
1134         /* Set default options on configuration */
1135         cf_sk->conn_req.priority = CAIF_PRIO_NORMAL;
1136         cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1137         cf_sk->conn_req.protocol = protocol;
1138         /* Increase the number of sockets created. */
1139         dbfs_atomic_inc(&cnt.caif_nr_socks);
1140 #ifdef CONFIG_DEBUG_FS
1141         if (!IS_ERR(debugfsdir)) {
1142                 /* Fill in some information concerning the misc socket. */
1143                 snprintf(cf_sk->name, sizeof(cf_sk->name), "cfsk%d",
1144                                 atomic_read(&cnt.caif_nr_socks));
1145
1146                 cf_sk->debugfs_socket_dir =
1147                         debugfs_create_dir(cf_sk->name, debugfsdir);
1148                 debugfs_create_u32("sk_state", S_IRUSR | S_IWUSR,
1149                                 cf_sk->debugfs_socket_dir,
1150                                 (u32 *) &cf_sk->sk.sk_state);
1151                 debugfs_create_u32("flow_state", S_IRUSR | S_IWUSR,
1152                                 cf_sk->debugfs_socket_dir, &cf_sk->flow_state);
1153                 debugfs_create_u32("sk_rmem_alloc", S_IRUSR | S_IWUSR,
1154                                 cf_sk->debugfs_socket_dir,
1155                                 (u32 *) &cf_sk->sk.sk_rmem_alloc);
1156                 debugfs_create_u32("sk_wmem_alloc", S_IRUSR | S_IWUSR,
1157                                 cf_sk->debugfs_socket_dir,
1158                                 (u32 *) &cf_sk->sk.sk_wmem_alloc);
1159                 debugfs_create_u32("identity", S_IRUSR | S_IWUSR,
1160                                 cf_sk->debugfs_socket_dir,
1161                                 (u32 *) &cf_sk->layer.id);
1162         }
1163 #endif
1164         release_sock(&cf_sk->sk);
1165         return 0;
1166 }
1167
1168
1169 static struct net_proto_family caif_family_ops = {
1170         .family = PF_CAIF,
1171         .create = caif_create,
1172         .owner = THIS_MODULE,
1173 };
1174
1175 static int af_caif_init(void)
1176 {
1177         int err = sock_register(&caif_family_ops);
1178         if (!err)
1179                 return err;
1180         return 0;
1181 }
1182
1183 static int __init caif_sktinit_module(void)
1184 {
1185 #ifdef CONFIG_DEBUG_FS
1186         debugfsdir = debugfs_create_dir("caif_sk", NULL);
1187         if (!IS_ERR(debugfsdir)) {
1188                 debugfs_create_u32("num_sockets", S_IRUSR | S_IWUSR,
1189                                 debugfsdir,
1190                                 (u32 *) &cnt.caif_nr_socks);
1191                 debugfs_create_u32("num_connect_req", S_IRUSR | S_IWUSR,
1192                                 debugfsdir,
1193                                 (u32 *) &cnt.num_connect_req);
1194                 debugfs_create_u32("num_connect_resp", S_IRUSR | S_IWUSR,
1195                                 debugfsdir,
1196                                 (u32 *) &cnt.num_connect_resp);
1197                 debugfs_create_u32("num_connect_fail_resp", S_IRUSR | S_IWUSR,
1198                                 debugfsdir,
1199                                 (u32 *) &cnt.num_connect_fail_resp);
1200                 debugfs_create_u32("num_disconnect", S_IRUSR | S_IWUSR,
1201                                 debugfsdir,
1202                                 (u32 *) &cnt.num_disconnect);
1203                 debugfs_create_u32("num_remote_shutdown_ind",
1204                                 S_IRUSR | S_IWUSR, debugfsdir,
1205                                 (u32 *) &cnt.num_remote_shutdown_ind);
1206                 debugfs_create_u32("num_tx_flow_off_ind", S_IRUSR | S_IWUSR,
1207                                 debugfsdir,
1208                                 (u32 *) &cnt.num_tx_flow_off_ind);
1209                 debugfs_create_u32("num_tx_flow_on_ind", S_IRUSR | S_IWUSR,
1210                                 debugfsdir,
1211                                 (u32 *) &cnt.num_tx_flow_on_ind);
1212                 debugfs_create_u32("num_rx_flow_off", S_IRUSR | S_IWUSR,
1213                                 debugfsdir,
1214                                 (u32 *) &cnt.num_rx_flow_off);
1215                 debugfs_create_u32("num_rx_flow_on", S_IRUSR | S_IWUSR,
1216                                 debugfsdir,
1217                                 (u32 *) &cnt.num_rx_flow_on);
1218         }
1219 #endif
1220         return af_caif_init();
1221 }
1222
1223 static void __exit caif_sktexit_module(void)
1224 {
1225         sock_unregister(PF_CAIF);
1226         if (debugfsdir != NULL)
1227                 debugfs_remove_recursive(debugfsdir);
1228 }
1229 module_init(caif_sktinit_module);
1230 module_exit(caif_sktexit_module);