ipv4: flush route cache after change accept_local
[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 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
8
9 #include <linux/fs.h>
10 #include <linux/init.h>
11 #include <linux/module.h>
12 #include <linux/sched.h>
13 #include <linux/spinlock.h>
14 #include <linux/mutex.h>
15 #include <linux/list.h>
16 #include <linux/wait.h>
17 #include <linux/poll.h>
18 #include <linux/tcp.h>
19 #include <linux/uaccess.h>
20 #include <linux/debugfs.h>
21 #include <linux/caif/caif_socket.h>
22 #include <linux/atomic.h>
23 #include <net/sock.h>
24 #include <net/tcp_states.h>
25 #include <net/caif/caif_layer.h>
26 #include <net/caif/caif_dev.h>
27 #include <net/caif/cfpkt.h>
28
29 MODULE_LICENSE("GPL");
30 MODULE_ALIAS_NETPROTO(AF_CAIF);
31
32 /*
33  * CAIF state is re-using the TCP socket states.
34  * caif_states stored in sk_state reflect the state as reported by
35  * the CAIF stack, while sk_socket->state is the state of the socket.
36  */
37 enum caif_states {
38         CAIF_CONNECTED          = TCP_ESTABLISHED,
39         CAIF_CONNECTING = TCP_SYN_SENT,
40         CAIF_DISCONNECTED       = TCP_CLOSE
41 };
42
43 #define TX_FLOW_ON_BIT  1
44 #define RX_FLOW_ON_BIT  2
45
46 static struct dentry *debugfsdir;
47
48 #ifdef CONFIG_DEBUG_FS
49 struct debug_fs_counter {
50         atomic_t caif_nr_socks;
51         atomic_t caif_sock_create;
52         atomic_t num_connect_req;
53         atomic_t num_connect_resp;
54         atomic_t num_connect_fail_resp;
55         atomic_t num_disconnect;
56         atomic_t num_remote_shutdown_ind;
57         atomic_t num_tx_flow_off_ind;
58         atomic_t num_tx_flow_on_ind;
59         atomic_t num_rx_flow_off;
60         atomic_t num_rx_flow_on;
61 };
62 static struct debug_fs_counter cnt;
63 #define dbfs_atomic_inc(v) atomic_inc_return(v)
64 #define dbfs_atomic_dec(v) atomic_dec_return(v)
65 #else
66 #define dbfs_atomic_inc(v) 0
67 #define dbfs_atomic_dec(v) 0
68 #endif
69
70 struct caifsock {
71         struct sock sk; /* must be first member */
72         struct cflayer layer;
73         char name[CAIF_LAYER_NAME_SZ]; /* Used for debugging */
74         u32 flow_state;
75         struct caif_connect_request conn_req;
76         struct mutex readlock;
77         struct dentry *debugfs_socket_dir;
78         int headroom, tailroom, maxframe;
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                 if (net_ratelimit())
160                         pr_debug("sending flow OFF (queue len = %d %d)\n",
161                                         atomic_read(&cf_sk->sk.sk_rmem_alloc),
162                                         sk_rcvbuf_lowwater(cf_sk));
163                 set_rx_flow_off(cf_sk);
164                 dbfs_atomic_inc(&cnt.num_rx_flow_off);
165                 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
166         }
167
168         err = sk_filter(sk, skb);
169         if (err)
170                 return err;
171         if (!sk_rmem_schedule(sk, skb->truesize) && rx_flow_is_on(cf_sk)) {
172                 set_rx_flow_off(cf_sk);
173                 if (net_ratelimit())
174                         pr_debug("sending flow OFF due to rmem_schedule\n");
175                 dbfs_atomic_inc(&cnt.num_rx_flow_off);
176                 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
177         }
178         skb->dev = NULL;
179         skb_set_owner_r(skb, sk);
180         /* Cache the SKB length before we tack it onto the receive
181          * queue. Once it is added it no longer belongs to us and
182          * may be freed by other threads of control pulling packets
183          * from the queue.
184          */
185         skb_len = skb->len;
186         spin_lock_irqsave(&list->lock, flags);
187         if (!sock_flag(sk, SOCK_DEAD))
188                 __skb_queue_tail(list, skb);
189         spin_unlock_irqrestore(&list->lock, flags);
190
191         if (!sock_flag(sk, SOCK_DEAD))
192                 sk->sk_data_ready(sk, skb_len);
193         else
194                 kfree_skb(skb);
195         return 0;
196 }
197
198 /* Packet Receive Callback function called from CAIF Stack */
199 static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
200 {
201         struct caifsock *cf_sk;
202         struct sk_buff *skb;
203
204         cf_sk = container_of(layr, struct caifsock, layer);
205         skb = cfpkt_tonative(pkt);
206
207         if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) {
208                 kfree_skb(skb);
209                 return 0;
210         }
211         caif_queue_rcv_skb(&cf_sk->sk, skb);
212         return 0;
213 }
214
215 static void cfsk_hold(struct cflayer *layr)
216 {
217         struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
218         sock_hold(&cf_sk->sk);
219 }
220
221 static void cfsk_put(struct cflayer *layr)
222 {
223         struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
224         sock_put(&cf_sk->sk);
225 }
226
227 /* Packet Control Callback function called from CAIF */
228 static void caif_ctrl_cb(struct cflayer *layr,
229                                 enum caif_ctrlcmd flow,
230                                 int phyid)
231 {
232         struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
233         switch (flow) {
234         case CAIF_CTRLCMD_FLOW_ON_IND:
235                 /* OK from modem to start sending again */
236                 dbfs_atomic_inc(&cnt.num_tx_flow_on_ind);
237                 set_tx_flow_on(cf_sk);
238                 cf_sk->sk.sk_state_change(&cf_sk->sk);
239                 break;
240
241         case CAIF_CTRLCMD_FLOW_OFF_IND:
242                 /* Modem asks us to shut up */
243                 dbfs_atomic_inc(&cnt.num_tx_flow_off_ind);
244                 set_tx_flow_off(cf_sk);
245                 cf_sk->sk.sk_state_change(&cf_sk->sk);
246                 break;
247
248         case CAIF_CTRLCMD_INIT_RSP:
249                 /* We're now connected */
250                 caif_client_register_refcnt(&cf_sk->layer,
251                                                 cfsk_hold, cfsk_put);
252                 dbfs_atomic_inc(&cnt.num_connect_resp);
253                 cf_sk->sk.sk_state = CAIF_CONNECTED;
254                 set_tx_flow_on(cf_sk);
255                 cf_sk->sk.sk_state_change(&cf_sk->sk);
256                 break;
257
258         case CAIF_CTRLCMD_DEINIT_RSP:
259                 /* We're now disconnected */
260                 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
261                 cf_sk->sk.sk_state_change(&cf_sk->sk);
262                 break;
263
264         case CAIF_CTRLCMD_INIT_FAIL_RSP:
265                 /* Connect request failed */
266                 dbfs_atomic_inc(&cnt.num_connect_fail_resp);
267                 cf_sk->sk.sk_err = ECONNREFUSED;
268                 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
269                 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
270                 /*
271                  * Socket "standards" seems to require POLLOUT to
272                  * be set at connect failure.
273                  */
274                 set_tx_flow_on(cf_sk);
275                 cf_sk->sk.sk_state_change(&cf_sk->sk);
276                 break;
277
278         case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
279                 /* Modem has closed this connection, or device is down. */
280                 dbfs_atomic_inc(&cnt.num_remote_shutdown_ind);
281                 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
282                 cf_sk->sk.sk_err = ECONNRESET;
283                 set_rx_flow_on(cf_sk);
284                 cf_sk->sk.sk_error_report(&cf_sk->sk);
285                 break;
286
287         default:
288                 pr_debug("Unexpected flow command %d\n", flow);
289         }
290 }
291
292 static void caif_check_flow_release(struct sock *sk)
293 {
294         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
295
296         if (rx_flow_is_on(cf_sk))
297                 return;
298
299         if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) {
300                         dbfs_atomic_inc(&cnt.num_rx_flow_on);
301                         set_rx_flow_on(cf_sk);
302                         caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ);
303         }
304 }
305
306 /*
307  * Copied from unix_dgram_recvmsg, but removed credit checks,
308  * changed locking, address handling and added MSG_TRUNC.
309  */
310 static int caif_seqpkt_recvmsg(struct kiocb *iocb, struct socket *sock,
311                                 struct msghdr *m, size_t len, int flags)
312
313 {
314         struct sock *sk = sock->sk;
315         struct sk_buff *skb;
316         int ret;
317         int copylen;
318
319         ret = -EOPNOTSUPP;
320         if (m->msg_flags&MSG_OOB)
321                 goto read_error;
322
323         skb = skb_recv_datagram(sk, flags, 0 , &ret);
324         if (!skb)
325                 goto read_error;
326         copylen = skb->len;
327         if (len < copylen) {
328                 m->msg_flags |= MSG_TRUNC;
329                 copylen = len;
330         }
331
332         ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, copylen);
333         if (ret)
334                 goto out_free;
335
336         ret = (flags & MSG_TRUNC) ? skb->len : copylen;
337 out_free:
338         skb_free_datagram(sk, skb);
339         caif_check_flow_release(sk);
340         return ret;
341
342 read_error:
343         return ret;
344 }
345
346
347 /* Copied from unix_stream_wait_data, identical except for lock call. */
348 static long caif_stream_data_wait(struct sock *sk, long timeo)
349 {
350         DEFINE_WAIT(wait);
351         lock_sock(sk);
352
353         for (;;) {
354                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
355
356                 if (!skb_queue_empty(&sk->sk_receive_queue) ||
357                         sk->sk_err ||
358                         sk->sk_state != CAIF_CONNECTED ||
359                         sock_flag(sk, SOCK_DEAD) ||
360                         (sk->sk_shutdown & RCV_SHUTDOWN) ||
361                         signal_pending(current) ||
362                         !timeo)
363                         break;
364
365                 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
366                 release_sock(sk);
367                 timeo = schedule_timeout(timeo);
368                 lock_sock(sk);
369                 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
370         }
371
372         finish_wait(sk_sleep(sk), &wait);
373         release_sock(sk);
374         return timeo;
375 }
376
377
378 /*
379  * Copied from unix_stream_recvmsg, but removed credit checks,
380  * changed locking calls, changed address handling.
381  */
382 static int caif_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
383                                 struct msghdr *msg, size_t size,
384                                 int flags)
385 {
386         struct sock *sk = sock->sk;
387         int copied = 0;
388         int target;
389         int err = 0;
390         long timeo;
391
392         err = -EOPNOTSUPP;
393         if (flags&MSG_OOB)
394                 goto out;
395
396         msg->msg_namelen = 0;
397
398         /*
399          * Lock the socket to prevent queue disordering
400          * while sleeps in memcpy_tomsg
401          */
402         err = -EAGAIN;
403         if (sk->sk_state == CAIF_CONNECTING)
404                 goto out;
405
406         caif_read_lock(sk);
407         target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
408         timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
409
410         do {
411                 int chunk;
412                 struct sk_buff *skb;
413
414                 lock_sock(sk);
415                 skb = skb_dequeue(&sk->sk_receive_queue);
416                 caif_check_flow_release(sk);
417
418                 if (skb == NULL) {
419                         if (copied >= target)
420                                 goto unlock;
421                         /*
422                          *      POSIX 1003.1g mandates this order.
423                          */
424                         err = sock_error(sk);
425                         if (err)
426                                 goto unlock;
427                         err = -ECONNRESET;
428                         if (sk->sk_shutdown & RCV_SHUTDOWN)
429                                 goto unlock;
430
431                         err = -EPIPE;
432                         if (sk->sk_state != CAIF_CONNECTED)
433                                 goto unlock;
434                         if (sock_flag(sk, SOCK_DEAD))
435                                 goto unlock;
436
437                         release_sock(sk);
438
439                         err = -EAGAIN;
440                         if (!timeo)
441                                 break;
442
443                         caif_read_unlock(sk);
444
445                         timeo = caif_stream_data_wait(sk, timeo);
446
447                         if (signal_pending(current)) {
448                                 err = sock_intr_errno(timeo);
449                                 goto out;
450                         }
451                         caif_read_lock(sk);
452                         continue;
453 unlock:
454                         release_sock(sk);
455                         break;
456                 }
457                 release_sock(sk);
458                 chunk = min_t(unsigned int, skb->len, size);
459                 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
460                         skb_queue_head(&sk->sk_receive_queue, skb);
461                         if (copied == 0)
462                                 copied = -EFAULT;
463                         break;
464                 }
465                 copied += chunk;
466                 size -= chunk;
467
468                 /* Mark read part of skb as used */
469                 if (!(flags & MSG_PEEK)) {
470                         skb_pull(skb, chunk);
471
472                         /* put the skb back if we didn't use it up. */
473                         if (skb->len) {
474                                 skb_queue_head(&sk->sk_receive_queue, skb);
475                                 break;
476                         }
477                         kfree_skb(skb);
478
479                 } else {
480                         /*
481                          * It is questionable, see note in unix_dgram_recvmsg.
482                          */
483                         /* put message back and return */
484                         skb_queue_head(&sk->sk_receive_queue, skb);
485                         break;
486                 }
487         } while (size);
488         caif_read_unlock(sk);
489
490 out:
491         return copied ? : err;
492 }
493
494 /*
495  * Copied from sock.c:sock_wait_for_wmem, but change to wait for
496  * CAIF flow-on and sock_writable.
497  */
498 static long caif_wait_for_flow_on(struct caifsock *cf_sk,
499                                 int wait_writeable, long timeo, int *err)
500 {
501         struct sock *sk = &cf_sk->sk;
502         DEFINE_WAIT(wait);
503         for (;;) {
504                 *err = 0;
505                 if (tx_flow_is_on(cf_sk) &&
506                         (!wait_writeable || sock_writeable(&cf_sk->sk)))
507                         break;
508                 *err = -ETIMEDOUT;
509                 if (!timeo)
510                         break;
511                 *err = -ERESTARTSYS;
512                 if (signal_pending(current))
513                         break;
514                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
515                 *err = -ECONNRESET;
516                 if (sk->sk_shutdown & SHUTDOWN_MASK)
517                         break;
518                 *err = -sk->sk_err;
519                 if (sk->sk_err)
520                         break;
521                 *err = -EPIPE;
522                 if (cf_sk->sk.sk_state != CAIF_CONNECTED)
523                         break;
524                 timeo = schedule_timeout(timeo);
525         }
526         finish_wait(sk_sleep(sk), &wait);
527         return timeo;
528 }
529
530 /*
531  * Transmit a SKB. The device may temporarily request re-transmission
532  * by returning EAGAIN.
533  */
534 static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk,
535                         int noblock, long timeo)
536 {
537         struct cfpkt *pkt;
538
539         pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb);
540         memset(skb->cb, 0, sizeof(struct caif_payload_info));
541
542         if (cf_sk->layer.dn == NULL)
543                 return -EINVAL;
544
545         return cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
546 }
547
548 /* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
549 static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock,
550                         struct msghdr *msg, size_t len)
551 {
552         struct sock *sk = sock->sk;
553         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
554         int buffer_size;
555         int ret = 0;
556         struct sk_buff *skb = NULL;
557         int noblock;
558         long timeo;
559         caif_assert(cf_sk);
560         ret = sock_error(sk);
561         if (ret)
562                 goto err;
563
564         ret = -EOPNOTSUPP;
565         if (msg->msg_flags&MSG_OOB)
566                 goto err;
567
568         ret = -EOPNOTSUPP;
569         if (msg->msg_namelen)
570                 goto err;
571
572         ret = -EINVAL;
573         if (unlikely(msg->msg_iov->iov_base == NULL))
574                 goto err;
575         noblock = msg->msg_flags & MSG_DONTWAIT;
576
577         timeo = sock_sndtimeo(sk, noblock);
578         timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
579                                 1, timeo, &ret);
580
581         if (ret)
582                 goto err;
583         ret = -EPIPE;
584         if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
585                 sock_flag(sk, SOCK_DEAD) ||
586                 (sk->sk_shutdown & RCV_SHUTDOWN))
587                 goto err;
588
589         /* Error if trying to write more than maximum frame size. */
590         ret = -EMSGSIZE;
591         if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM)
592                 goto err;
593
594         buffer_size = len + cf_sk->headroom + cf_sk->tailroom;
595
596         ret = -ENOMEM;
597         skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
598
599         if (!skb || skb_tailroom(skb) < buffer_size)
600                 goto err;
601
602         skb_reserve(skb, cf_sk->headroom);
603
604         ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
605
606         if (ret)
607                 goto err;
608         ret = transmit_skb(skb, cf_sk, noblock, timeo);
609         if (ret < 0)
610                 /* skb is already freed */
611                 return ret;
612
613         return len;
614 err:
615         kfree_skb(skb);
616         return ret;
617 }
618
619 /*
620  * Copied from unix_stream_sendmsg and adapted to CAIF:
621  * Changed removed permission handling and added waiting for flow on
622  * and other minor adaptations.
623  */
624 static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
625                                 struct msghdr *msg, size_t len)
626 {
627         struct sock *sk = sock->sk;
628         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
629         int err, size;
630         struct sk_buff *skb;
631         int sent = 0;
632         long timeo;
633
634         err = -EOPNOTSUPP;
635         if (unlikely(msg->msg_flags&MSG_OOB))
636                 goto out_err;
637
638         if (unlikely(msg->msg_namelen))
639                 goto out_err;
640
641         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
642         timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
643
644         if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
645                 goto pipe_err;
646
647         while (sent < len) {
648
649                 size = len-sent;
650
651                 if (size > cf_sk->maxframe)
652                         size = cf_sk->maxframe;
653
654                 /* If size is more than half of sndbuf, chop up message */
655                 if (size > ((sk->sk_sndbuf >> 1) - 64))
656                         size = (sk->sk_sndbuf >> 1) - 64;
657
658                 if (size > SKB_MAX_ALLOC)
659                         size = SKB_MAX_ALLOC;
660
661                 skb = sock_alloc_send_skb(sk,
662                                         size + cf_sk->headroom +
663                                         cf_sk->tailroom,
664                                         msg->msg_flags&MSG_DONTWAIT,
665                                         &err);
666                 if (skb == NULL)
667                         goto out_err;
668
669                 skb_reserve(skb, cf_sk->headroom);
670                 /*
671                  *      If you pass two values to the sock_alloc_send_skb
672                  *      it tries to grab the large buffer with GFP_NOFS
673                  *      (which can fail easily), and if it fails grab the
674                  *      fallback size buffer which is under a page and will
675                  *      succeed. [Alan]
676                  */
677                 size = min_t(int, size, skb_tailroom(skb));
678
679                 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
680                 if (err) {
681                         kfree_skb(skb);
682                         goto out_err;
683                 }
684                 err = transmit_skb(skb, cf_sk,
685                                 msg->msg_flags&MSG_DONTWAIT, timeo);
686                 if (err < 0) {
687                         kfree_skb(skb);
688                         goto pipe_err;
689                 }
690                 sent += size;
691         }
692
693         return sent;
694
695 pipe_err:
696         if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
697                 send_sig(SIGPIPE, current, 0);
698         err = -EPIPE;
699 out_err:
700         return sent ? : err;
701 }
702
703 static int setsockopt(struct socket *sock,
704                         int lvl, int opt, char __user *ov, unsigned int ol)
705 {
706         struct sock *sk = sock->sk;
707         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
708         int linksel;
709
710         if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
711                 return -ENOPROTOOPT;
712
713         switch (opt) {
714         case CAIFSO_LINK_SELECT:
715                 if (ol < sizeof(int))
716                         return -EINVAL;
717                 if (lvl != SOL_CAIF)
718                         goto bad_sol;
719                 if (copy_from_user(&linksel, ov, sizeof(int)))
720                         return -EINVAL;
721                 lock_sock(&(cf_sk->sk));
722                 cf_sk->conn_req.link_selector = linksel;
723                 release_sock(&cf_sk->sk);
724                 return 0;
725
726         case CAIFSO_REQ_PARAM:
727                 if (lvl != SOL_CAIF)
728                         goto bad_sol;
729                 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
730                         return -ENOPROTOOPT;
731                 lock_sock(&(cf_sk->sk));
732                 if (ol > sizeof(cf_sk->conn_req.param.data) ||
733                         copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) {
734                         release_sock(&cf_sk->sk);
735                         return -EINVAL;
736                 }
737                 cf_sk->conn_req.param.size = ol;
738                 release_sock(&cf_sk->sk);
739                 return 0;
740
741         default:
742                 return -ENOPROTOOPT;
743         }
744
745         return 0;
746 bad_sol:
747         return -ENOPROTOOPT;
748
749 }
750
751 /*
752  * caif_connect() - Connect a CAIF Socket
753  * Copied and modified af_irda.c:irda_connect().
754  *
755  * Note : by consulting "errno", the user space caller may learn the cause
756  * of the failure. Most of them are visible in the function, others may come
757  * from subroutines called and are listed here :
758  *  o -EAFNOSUPPORT: bad socket family or type.
759  *  o -ESOCKTNOSUPPORT: bad socket type or protocol
760  *  o -EINVAL: bad socket address, or CAIF link type
761  *  o -ECONNREFUSED: remote end refused the connection.
762  *  o -EINPROGRESS: connect request sent but timed out (or non-blocking)
763  *  o -EISCONN: already connected.
764  *  o -ETIMEDOUT: Connection timed out (send timeout)
765  *  o -ENODEV: No link layer to send request
766  *  o -ECONNRESET: Received Shutdown indication or lost link layer
767  *  o -ENOMEM: Out of memory
768  *
769  *  State Strategy:
770  *  o sk_state: holds the CAIF_* protocol state, it's updated by
771  *      caif_ctrl_cb.
772  *  o sock->state: holds the SS_* socket state and is updated by connect and
773  *      disconnect.
774  */
775 static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
776                         int addr_len, int flags)
777 {
778         struct sock *sk = sock->sk;
779         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
780         long timeo;
781         int err;
782         int ifindex, headroom, tailroom;
783         unsigned int mtu;
784         struct net_device *dev;
785
786         lock_sock(sk);
787
788         err = -EAFNOSUPPORT;
789         if (uaddr->sa_family != AF_CAIF)
790                 goto out;
791
792         switch (sock->state) {
793         case SS_UNCONNECTED:
794                 /* Normal case, a fresh connect */
795                 caif_assert(sk->sk_state == CAIF_DISCONNECTED);
796                 break;
797         case SS_CONNECTING:
798                 switch (sk->sk_state) {
799                 case CAIF_CONNECTED:
800                         sock->state = SS_CONNECTED;
801                         err = -EISCONN;
802                         goto out;
803                 case CAIF_DISCONNECTED:
804                         /* Reconnect allowed */
805                         break;
806                 case CAIF_CONNECTING:
807                         err = -EALREADY;
808                         if (flags & O_NONBLOCK)
809                                 goto out;
810                         goto wait_connect;
811                 }
812                 break;
813         case SS_CONNECTED:
814                 caif_assert(sk->sk_state == CAIF_CONNECTED ||
815                                 sk->sk_state == CAIF_DISCONNECTED);
816                 if (sk->sk_shutdown & SHUTDOWN_MASK) {
817                         /* Allow re-connect after SHUTDOWN_IND */
818                         caif_disconnect_client(sock_net(sk), &cf_sk->layer);
819                         caif_free_client(&cf_sk->layer);
820                         break;
821                 }
822                 /* No reconnect on a seqpacket socket */
823                 err = -EISCONN;
824                 goto out;
825         case SS_DISCONNECTING:
826         case SS_FREE:
827                 caif_assert(1); /*Should never happen */
828                 break;
829         }
830         sk->sk_state = CAIF_DISCONNECTED;
831         sock->state = SS_UNCONNECTED;
832         sk_stream_kill_queues(&cf_sk->sk);
833
834         err = -EINVAL;
835         if (addr_len != sizeof(struct sockaddr_caif))
836                 goto out;
837
838         memcpy(&cf_sk->conn_req.sockaddr, uaddr,
839                 sizeof(struct sockaddr_caif));
840
841         /* Move to connecting socket, start sending Connect Requests */
842         sock->state = SS_CONNECTING;
843         sk->sk_state = CAIF_CONNECTING;
844
845         /* Check priority value comming from socket */
846         /* if priority value is out of range it will be ajusted */
847         if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX)
848                 cf_sk->conn_req.priority = CAIF_PRIO_MAX;
849         else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN)
850                 cf_sk->conn_req.priority = CAIF_PRIO_MIN;
851         else
852                 cf_sk->conn_req.priority = cf_sk->sk.sk_priority;
853
854         /*ifindex = id of the interface.*/
855         cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if;
856
857         dbfs_atomic_inc(&cnt.num_connect_req);
858         cf_sk->layer.receive = caif_sktrecv_cb;
859
860         err = caif_connect_client(sock_net(sk), &cf_sk->conn_req,
861                                 &cf_sk->layer, &ifindex, &headroom, &tailroom);
862
863         if (err < 0) {
864                 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
865                 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
866                 goto out;
867         }
868
869         err = -ENODEV;
870         rcu_read_lock();
871         dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
872         if (!dev) {
873                 rcu_read_unlock();
874                 goto out;
875         }
876         cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom);
877         mtu = dev->mtu;
878         rcu_read_unlock();
879
880         cf_sk->tailroom = tailroom;
881         cf_sk->maxframe = mtu - (headroom + tailroom);
882         if (cf_sk->maxframe < 1) {
883                 pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu);
884                 err = -ENODEV;
885                 goto out;
886         }
887
888         err = -EINPROGRESS;
889 wait_connect:
890
891         if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
892                 goto out;
893
894         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
895
896         release_sock(sk);
897         err = -ERESTARTSYS;
898         timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
899                         sk->sk_state != CAIF_CONNECTING,
900                         timeo);
901         lock_sock(sk);
902         if (timeo < 0)
903                 goto out; /* -ERESTARTSYS */
904
905         err = -ETIMEDOUT;
906         if (timeo == 0 && sk->sk_state != CAIF_CONNECTED)
907                 goto out;
908         if (sk->sk_state != CAIF_CONNECTED) {
909                 sock->state = SS_UNCONNECTED;
910                 err = sock_error(sk);
911                 if (!err)
912                         err = -ECONNREFUSED;
913                 goto out;
914         }
915         sock->state = SS_CONNECTED;
916         err = 0;
917 out:
918         release_sock(sk);
919         return err;
920 }
921
922 /*
923  * caif_release() - Disconnect a CAIF Socket
924  * Copied and modified af_irda.c:irda_release().
925  */
926 static int caif_release(struct socket *sock)
927 {
928         struct sock *sk = sock->sk;
929         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
930
931         if (!sk)
932                 return 0;
933
934         set_tx_flow_off(cf_sk);
935
936         /*
937          * Ensure that packets are not queued after this point in time.
938          * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
939          * this ensures no packets when sock is dead.
940          */
941         spin_lock_bh(&sk->sk_receive_queue.lock);
942         sock_set_flag(sk, SOCK_DEAD);
943         spin_unlock_bh(&sk->sk_receive_queue.lock);
944         sock->sk = NULL;
945
946         dbfs_atomic_inc(&cnt.num_disconnect);
947
948         WARN_ON(IS_ERR(cf_sk->debugfs_socket_dir));
949         if (cf_sk->debugfs_socket_dir != NULL)
950                 debugfs_remove_recursive(cf_sk->debugfs_socket_dir);
951
952         lock_sock(&(cf_sk->sk));
953         sk->sk_state = CAIF_DISCONNECTED;
954         sk->sk_shutdown = SHUTDOWN_MASK;
955
956         caif_disconnect_client(sock_net(sk), &cf_sk->layer);
957         cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
958         wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP);
959
960         sock_orphan(sk);
961         sk_stream_kill_queues(&cf_sk->sk);
962         release_sock(sk);
963         sock_put(sk);
964         return 0;
965 }
966
967 /* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */
968 static unsigned int caif_poll(struct file *file,
969                                 struct socket *sock, poll_table *wait)
970 {
971         struct sock *sk = sock->sk;
972         unsigned int mask;
973         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
974
975         sock_poll_wait(file, sk_sleep(sk), wait);
976         mask = 0;
977
978         /* exceptional events? */
979         if (sk->sk_err)
980                 mask |= POLLERR;
981         if (sk->sk_shutdown == SHUTDOWN_MASK)
982                 mask |= POLLHUP;
983         if (sk->sk_shutdown & RCV_SHUTDOWN)
984                 mask |= POLLRDHUP;
985
986         /* readable? */
987         if (!skb_queue_empty(&sk->sk_receive_queue) ||
988                 (sk->sk_shutdown & RCV_SHUTDOWN))
989                 mask |= POLLIN | POLLRDNORM;
990
991         /*
992          * we set writable also when the other side has shut down the
993          * connection. This prevents stuck sockets.
994          */
995         if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
996                 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
997
998         return mask;
999 }
1000
1001 static const struct proto_ops caif_seqpacket_ops = {
1002         .family = PF_CAIF,
1003         .owner = THIS_MODULE,
1004         .release = caif_release,
1005         .bind = sock_no_bind,
1006         .connect = caif_connect,
1007         .socketpair = sock_no_socketpair,
1008         .accept = sock_no_accept,
1009         .getname = sock_no_getname,
1010         .poll = caif_poll,
1011         .ioctl = sock_no_ioctl,
1012         .listen = sock_no_listen,
1013         .shutdown = sock_no_shutdown,
1014         .setsockopt = setsockopt,
1015         .getsockopt = sock_no_getsockopt,
1016         .sendmsg = caif_seqpkt_sendmsg,
1017         .recvmsg = caif_seqpkt_recvmsg,
1018         .mmap = sock_no_mmap,
1019         .sendpage = sock_no_sendpage,
1020 };
1021
1022 static const struct proto_ops caif_stream_ops = {
1023         .family = PF_CAIF,
1024         .owner = THIS_MODULE,
1025         .release = caif_release,
1026         .bind = sock_no_bind,
1027         .connect = caif_connect,
1028         .socketpair = sock_no_socketpair,
1029         .accept = sock_no_accept,
1030         .getname = sock_no_getname,
1031         .poll = caif_poll,
1032         .ioctl = sock_no_ioctl,
1033         .listen = sock_no_listen,
1034         .shutdown = sock_no_shutdown,
1035         .setsockopt = setsockopt,
1036         .getsockopt = sock_no_getsockopt,
1037         .sendmsg = caif_stream_sendmsg,
1038         .recvmsg = caif_stream_recvmsg,
1039         .mmap = sock_no_mmap,
1040         .sendpage = sock_no_sendpage,
1041 };
1042
1043 /* This function is called when a socket is finally destroyed. */
1044 static void caif_sock_destructor(struct sock *sk)
1045 {
1046         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1047         caif_assert(!atomic_read(&sk->sk_wmem_alloc));
1048         caif_assert(sk_unhashed(sk));
1049         caif_assert(!sk->sk_socket);
1050         if (!sock_flag(sk, SOCK_DEAD)) {
1051                 pr_debug("Attempt to release alive CAIF socket: %p\n", sk);
1052                 return;
1053         }
1054         sk_stream_kill_queues(&cf_sk->sk);
1055         dbfs_atomic_dec(&cnt.caif_nr_socks);
1056         caif_free_client(&cf_sk->layer);
1057 }
1058
1059 static int caif_create(struct net *net, struct socket *sock, int protocol,
1060                         int kern)
1061 {
1062         int num;
1063         struct sock *sk = NULL;
1064         struct caifsock *cf_sk = NULL;
1065         static struct proto prot = {.name = "PF_CAIF",
1066                 .owner = THIS_MODULE,
1067                 .obj_size = sizeof(struct caifsock),
1068         };
1069
1070         if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
1071                 return -EPERM;
1072         /*
1073          * The sock->type specifies the socket type to use.
1074          * The CAIF socket is a packet stream in the sense
1075          * that it is packet based. CAIF trusts the reliability
1076          * of the link, no resending is implemented.
1077          */
1078         if (sock->type == SOCK_SEQPACKET)
1079                 sock->ops = &caif_seqpacket_ops;
1080         else if (sock->type == SOCK_STREAM)
1081                 sock->ops = &caif_stream_ops;
1082         else
1083                 return -ESOCKTNOSUPPORT;
1084
1085         if (protocol < 0 || protocol >= CAIFPROTO_MAX)
1086                 return -EPROTONOSUPPORT;
1087         /*
1088          * Set the socket state to unconnected.  The socket state
1089          * is really not used at all in the net/core or socket.c but the
1090          * initialization makes sure that sock->state is not uninitialized.
1091          */
1092         sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot);
1093         if (!sk)
1094                 return -ENOMEM;
1095
1096         cf_sk = container_of(sk, struct caifsock, sk);
1097
1098         /* Store the protocol */
1099         sk->sk_protocol = (unsigned char) protocol;
1100
1101         /*
1102          * Lock in order to try to stop someone from opening the socket
1103          * too early.
1104          */
1105         lock_sock(&(cf_sk->sk));
1106
1107         /* Initialize the nozero default sock structure data. */
1108         sock_init_data(sock, sk);
1109         sk->sk_destruct = caif_sock_destructor;
1110
1111         mutex_init(&cf_sk->readlock); /* single task reading lock */
1112         cf_sk->layer.ctrlcmd = caif_ctrl_cb;
1113         cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
1114         cf_sk->sk.sk_state = CAIF_DISCONNECTED;
1115
1116         set_tx_flow_off(cf_sk);
1117         set_rx_flow_on(cf_sk);
1118
1119         /* Set default options on configuration */
1120         cf_sk->sk.sk_priority = CAIF_PRIO_NORMAL;
1121         cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1122         cf_sk->conn_req.protocol = protocol;
1123         /* Increase the number of sockets created. */
1124         dbfs_atomic_inc(&cnt.caif_nr_socks);
1125         num = dbfs_atomic_inc(&cnt.caif_sock_create);
1126 #ifdef CONFIG_DEBUG_FS
1127         if (!IS_ERR(debugfsdir)) {
1128
1129                 /* Fill in some information concerning the misc socket. */
1130                 snprintf(cf_sk->name, sizeof(cf_sk->name), "cfsk%d", num);
1131
1132                 cf_sk->debugfs_socket_dir =
1133                         debugfs_create_dir(cf_sk->name, debugfsdir);
1134
1135                 debugfs_create_u32("sk_state", S_IRUSR | S_IWUSR,
1136                                 cf_sk->debugfs_socket_dir,
1137                                 (u32 *) &cf_sk->sk.sk_state);
1138                 debugfs_create_u32("flow_state", S_IRUSR | S_IWUSR,
1139                                 cf_sk->debugfs_socket_dir, &cf_sk->flow_state);
1140                 debugfs_create_u32("sk_rmem_alloc", S_IRUSR | S_IWUSR,
1141                                 cf_sk->debugfs_socket_dir,
1142                                 (u32 *) &cf_sk->sk.sk_rmem_alloc);
1143                 debugfs_create_u32("sk_wmem_alloc", S_IRUSR | S_IWUSR,
1144                                 cf_sk->debugfs_socket_dir,
1145                                 (u32 *) &cf_sk->sk.sk_wmem_alloc);
1146                 debugfs_create_u32("identity", S_IRUSR | S_IWUSR,
1147                                 cf_sk->debugfs_socket_dir,
1148                                 (u32 *) &cf_sk->layer.id);
1149         }
1150 #endif
1151         release_sock(&cf_sk->sk);
1152         return 0;
1153 }
1154
1155
1156 static struct net_proto_family caif_family_ops = {
1157         .family = PF_CAIF,
1158         .create = caif_create,
1159         .owner = THIS_MODULE,
1160 };
1161
1162 static int af_caif_init(void)
1163 {
1164         int err = sock_register(&caif_family_ops);
1165         if (!err)
1166                 return err;
1167         return 0;
1168 }
1169
1170 static int __init caif_sktinit_module(void)
1171 {
1172 #ifdef CONFIG_DEBUG_FS
1173         debugfsdir = debugfs_create_dir("caif_sk", NULL);
1174         if (!IS_ERR(debugfsdir)) {
1175                 debugfs_create_u32("num_sockets", S_IRUSR | S_IWUSR,
1176                                 debugfsdir,
1177                                 (u32 *) &cnt.caif_nr_socks);
1178                 debugfs_create_u32("num_create", S_IRUSR | S_IWUSR,
1179                                 debugfsdir,
1180                                 (u32 *) &cnt.caif_sock_create);
1181                 debugfs_create_u32("num_connect_req", S_IRUSR | S_IWUSR,
1182                                 debugfsdir,
1183                                 (u32 *) &cnt.num_connect_req);
1184                 debugfs_create_u32("num_connect_resp", S_IRUSR | S_IWUSR,
1185                                 debugfsdir,
1186                                 (u32 *) &cnt.num_connect_resp);
1187                 debugfs_create_u32("num_connect_fail_resp", S_IRUSR | S_IWUSR,
1188                                 debugfsdir,
1189                                 (u32 *) &cnt.num_connect_fail_resp);
1190                 debugfs_create_u32("num_disconnect", S_IRUSR | S_IWUSR,
1191                                 debugfsdir,
1192                                 (u32 *) &cnt.num_disconnect);
1193                 debugfs_create_u32("num_remote_shutdown_ind",
1194                                 S_IRUSR | S_IWUSR, debugfsdir,
1195                                 (u32 *) &cnt.num_remote_shutdown_ind);
1196                 debugfs_create_u32("num_tx_flow_off_ind", S_IRUSR | S_IWUSR,
1197                                 debugfsdir,
1198                                 (u32 *) &cnt.num_tx_flow_off_ind);
1199                 debugfs_create_u32("num_tx_flow_on_ind", S_IRUSR | S_IWUSR,
1200                                 debugfsdir,
1201                                 (u32 *) &cnt.num_tx_flow_on_ind);
1202                 debugfs_create_u32("num_rx_flow_off", S_IRUSR | S_IWUSR,
1203                                 debugfsdir,
1204                                 (u32 *) &cnt.num_rx_flow_off);
1205                 debugfs_create_u32("num_rx_flow_on", S_IRUSR | S_IWUSR,
1206                                 debugfsdir,
1207                                 (u32 *) &cnt.num_rx_flow_on);
1208         }
1209 #endif
1210         return af_caif_init();
1211 }
1212
1213 static void __exit caif_sktexit_module(void)
1214 {
1215         sock_unregister(PF_CAIF);
1216         if (debugfsdir != NULL)
1217                 debugfs_remove_recursive(debugfsdir);
1218 }
1219 module_init(caif_sktinit_module);
1220 module_exit(caif_sktexit_module);