8ce9047861166740a17a2448cb1d4f668fba1d21
[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 (4096*10)
32 #define CAIF_DEF_RCVBUF (4096*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         int headroom, tailroom, maxframe;
80 };
81
82 static int rx_flow_is_on(struct caifsock *cf_sk)
83 {
84         return test_bit(RX_FLOW_ON_BIT,
85                         (void *) &cf_sk->flow_state);
86 }
87
88 static int tx_flow_is_on(struct caifsock *cf_sk)
89 {
90         return test_bit(TX_FLOW_ON_BIT,
91                         (void *) &cf_sk->flow_state);
92 }
93
94 static void set_rx_flow_off(struct caifsock *cf_sk)
95 {
96          clear_bit(RX_FLOW_ON_BIT,
97                  (void *) &cf_sk->flow_state);
98 }
99
100 static void set_rx_flow_on(struct caifsock *cf_sk)
101 {
102          set_bit(RX_FLOW_ON_BIT,
103                         (void *) &cf_sk->flow_state);
104 }
105
106 static void set_tx_flow_off(struct caifsock *cf_sk)
107 {
108          clear_bit(TX_FLOW_ON_BIT,
109                 (void *) &cf_sk->flow_state);
110 }
111
112 static void set_tx_flow_on(struct caifsock *cf_sk)
113 {
114          set_bit(TX_FLOW_ON_BIT,
115                 (void *) &cf_sk->flow_state);
116 }
117
118 static void caif_read_lock(struct sock *sk)
119 {
120         struct caifsock *cf_sk;
121         cf_sk = container_of(sk, struct caifsock, sk);
122         mutex_lock(&cf_sk->readlock);
123 }
124
125 static void caif_read_unlock(struct sock *sk)
126 {
127         struct caifsock *cf_sk;
128         cf_sk = container_of(sk, struct caifsock, sk);
129         mutex_unlock(&cf_sk->readlock);
130 }
131
132 static int sk_rcvbuf_lowwater(struct caifsock *cf_sk)
133 {
134         /* A quarter of full buffer is used a low water mark */
135         return cf_sk->sk.sk_rcvbuf / 4;
136 }
137
138 static void caif_flow_ctrl(struct sock *sk, int mode)
139 {
140         struct caifsock *cf_sk;
141         cf_sk = container_of(sk, struct caifsock, sk);
142         if (cf_sk->layer.dn && cf_sk->layer.dn->modemcmd)
143                 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, mode);
144 }
145
146 /*
147  * Copied from sock.c:sock_queue_rcv_skb(), but changed so packets are
148  * not dropped, but CAIF is sending flow off instead.
149  */
150 static int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
151 {
152         int err;
153         int skb_len;
154         unsigned long flags;
155         struct sk_buff_head *list = &sk->sk_receive_queue;
156         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
157
158         if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
159                 (unsigned)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) {
160                 trace_printk("CAIF: %s():"
161                         " sending flow OFF (queue len = %d %d)\n",
162                         __func__,
163                         atomic_read(&cf_sk->sk.sk_rmem_alloc),
164                         sk_rcvbuf_lowwater(cf_sk));
165                 set_rx_flow_off(cf_sk);
166                 dbfs_atomic_inc(&cnt.num_rx_flow_off);
167                 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
168         }
169
170         err = sk_filter(sk, skb);
171         if (err)
172                 return err;
173         if (!sk_rmem_schedule(sk, skb->truesize) && rx_flow_is_on(cf_sk)) {
174                 set_rx_flow_off(cf_sk);
175                 trace_printk("CAIF: %s():"
176                         " sending flow OFF due to rmem_schedule\n",
177                         __func__);
178                 dbfs_atomic_inc(&cnt.num_rx_flow_off);
179                 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
180         }
181         skb->dev = NULL;
182         skb_set_owner_r(skb, sk);
183         /* Cache the SKB length before we tack it onto the receive
184          * queue. Once it is added it no longer belongs to us and
185          * may be freed by other threads of control pulling packets
186          * from the queue.
187          */
188         skb_len = skb->len;
189         spin_lock_irqsave(&list->lock, flags);
190         if (!sock_flag(sk, SOCK_DEAD))
191                 __skb_queue_tail(list, skb);
192         spin_unlock_irqrestore(&list->lock, flags);
193
194         if (!sock_flag(sk, SOCK_DEAD))
195                 sk->sk_data_ready(sk, skb_len);
196         else
197                 kfree_skb(skb);
198         return 0;
199 }
200
201 /* Packet Receive Callback function called from CAIF Stack */
202 static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
203 {
204         struct caifsock *cf_sk;
205         struct sk_buff *skb;
206
207         cf_sk = container_of(layr, struct caifsock, layer);
208         skb = cfpkt_tonative(pkt);
209
210         if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) {
211                 cfpkt_destroy(pkt);
212                 return 0;
213         }
214         caif_queue_rcv_skb(&cf_sk->sk, skb);
215         return 0;
216 }
217
218 /* Packet Control Callback function called from CAIF */
219 static void caif_ctrl_cb(struct cflayer *layr,
220                                 enum caif_ctrlcmd flow,
221                                 int phyid)
222 {
223         struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
224         switch (flow) {
225         case CAIF_CTRLCMD_FLOW_ON_IND:
226                 /* OK from modem to start sending again */
227                 dbfs_atomic_inc(&cnt.num_tx_flow_on_ind);
228                 set_tx_flow_on(cf_sk);
229                 cf_sk->sk.sk_state_change(&cf_sk->sk);
230                 break;
231
232         case CAIF_CTRLCMD_FLOW_OFF_IND:
233                 /* Modem asks us to shut up */
234                 dbfs_atomic_inc(&cnt.num_tx_flow_off_ind);
235                 set_tx_flow_off(cf_sk);
236                 cf_sk->sk.sk_state_change(&cf_sk->sk);
237                 break;
238
239         case CAIF_CTRLCMD_INIT_RSP:
240                 /* We're now connected */
241                 dbfs_atomic_inc(&cnt.num_connect_resp);
242                 cf_sk->sk.sk_state = CAIF_CONNECTED;
243                 set_tx_flow_on(cf_sk);
244                 cf_sk->sk.sk_state_change(&cf_sk->sk);
245                 break;
246
247         case CAIF_CTRLCMD_DEINIT_RSP:
248                 /* We're now disconnected */
249                 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
250                 cf_sk->sk.sk_state_change(&cf_sk->sk);
251                 cfcnfg_release_adap_layer(&cf_sk->layer);
252                 break;
253
254         case CAIF_CTRLCMD_INIT_FAIL_RSP:
255                 /* Connect request failed */
256                 dbfs_atomic_inc(&cnt.num_connect_fail_resp);
257                 cf_sk->sk.sk_err = ECONNREFUSED;
258                 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
259                 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
260                 /*
261                  * Socket "standards" seems to require POLLOUT to
262                  * be set at connect failure.
263                  */
264                 set_tx_flow_on(cf_sk);
265                 cf_sk->sk.sk_state_change(&cf_sk->sk);
266                 break;
267
268         case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
269                 /* Modem has closed this connection, or device is down. */
270                 dbfs_atomic_inc(&cnt.num_remote_shutdown_ind);
271                 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
272                 cf_sk->sk.sk_err = ECONNRESET;
273                 set_rx_flow_on(cf_sk);
274                 cf_sk->sk.sk_error_report(&cf_sk->sk);
275                 break;
276
277         default:
278                 pr_debug("CAIF: %s(): Unexpected flow command %d\n",
279                                 __func__, flow);
280         }
281 }
282
283 static void caif_check_flow_release(struct sock *sk)
284 {
285         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
286
287         if (rx_flow_is_on(cf_sk))
288                 return;
289
290         if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) {
291                         dbfs_atomic_inc(&cnt.num_rx_flow_on);
292                         set_rx_flow_on(cf_sk);
293                         caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ);
294         }
295 }
296
297 /*
298  * Copied from unix_dgram_recvmsg, but removed credit checks,
299  * changed locking, address handling and added MSG_TRUNC.
300  */
301 static int caif_seqpkt_recvmsg(struct kiocb *iocb, struct socket *sock,
302                                 struct msghdr *m, size_t len, int flags)
303
304 {
305         struct sock *sk = sock->sk;
306         struct sk_buff *skb;
307         int ret;
308         int copylen;
309
310         ret = -EOPNOTSUPP;
311         if (m->msg_flags&MSG_OOB)
312                 goto read_error;
313
314         skb = skb_recv_datagram(sk, flags, 0 , &ret);
315         if (!skb)
316                 goto read_error;
317         copylen = skb->len;
318         if (len < copylen) {
319                 m->msg_flags |= MSG_TRUNC;
320                 copylen = len;
321         }
322
323         ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, copylen);
324         if (ret)
325                 goto out_free;
326
327         ret = (flags & MSG_TRUNC) ? skb->len : copylen;
328 out_free:
329         skb_free_datagram(sk, skb);
330         caif_check_flow_release(sk);
331         return ret;
332
333 read_error:
334         return ret;
335 }
336
337
338 /* Copied from unix_stream_wait_data, identical except for lock call. */
339 static long caif_stream_data_wait(struct sock *sk, long timeo)
340 {
341         DEFINE_WAIT(wait);
342         lock_sock(sk);
343
344         for (;;) {
345                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
346
347                 if (!skb_queue_empty(&sk->sk_receive_queue) ||
348                         sk->sk_err ||
349                         sk->sk_state != CAIF_CONNECTED ||
350                         sock_flag(sk, SOCK_DEAD) ||
351                         (sk->sk_shutdown & RCV_SHUTDOWN) ||
352                         signal_pending(current) ||
353                         !timeo)
354                         break;
355
356                 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
357                 release_sock(sk);
358                 timeo = schedule_timeout(timeo);
359                 lock_sock(sk);
360                 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
361         }
362
363         finish_wait(sk_sleep(sk), &wait);
364         release_sock(sk);
365         return timeo;
366 }
367
368
369 /*
370  * Copied from unix_stream_recvmsg, but removed credit checks,
371  * changed locking calls, changed address handling.
372  */
373 static int caif_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
374                                 struct msghdr *msg, size_t size,
375                                 int flags)
376 {
377         struct sock *sk = sock->sk;
378         int copied = 0;
379         int target;
380         int err = 0;
381         long timeo;
382
383         err = -EOPNOTSUPP;
384         if (flags&MSG_OOB)
385                 goto out;
386
387         msg->msg_namelen = 0;
388
389         /*
390          * Lock the socket to prevent queue disordering
391          * while sleeps in memcpy_tomsg
392          */
393         err = -EAGAIN;
394         if (sk->sk_state == CAIF_CONNECTING)
395                 goto out;
396
397         caif_read_lock(sk);
398         target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
399         timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
400
401         do {
402                 int chunk;
403                 struct sk_buff *skb;
404
405                 lock_sock(sk);
406                 skb = skb_dequeue(&sk->sk_receive_queue);
407                 caif_check_flow_release(sk);
408
409                 if (skb == NULL) {
410                         if (copied >= target)
411                                 goto unlock;
412                         /*
413                          *      POSIX 1003.1g mandates this order.
414                          */
415                         err = sock_error(sk);
416                         if (err)
417                                 goto unlock;
418                         err = -ECONNRESET;
419                         if (sk->sk_shutdown & RCV_SHUTDOWN)
420                                 goto unlock;
421
422                         err = -EPIPE;
423                         if (sk->sk_state != CAIF_CONNECTED)
424                                 goto unlock;
425                         if (sock_flag(sk, SOCK_DEAD))
426                                 goto unlock;
427
428                         release_sock(sk);
429
430                         err = -EAGAIN;
431                         if (!timeo)
432                                 break;
433
434                         caif_read_unlock(sk);
435
436                         timeo = caif_stream_data_wait(sk, timeo);
437
438                         if (signal_pending(current)) {
439                                 err = sock_intr_errno(timeo);
440                                 goto out;
441                         }
442                         caif_read_lock(sk);
443                         continue;
444 unlock:
445                         release_sock(sk);
446                         break;
447                 }
448                 release_sock(sk);
449                 chunk = min_t(unsigned int, skb->len, size);
450                 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
451                         skb_queue_head(&sk->sk_receive_queue, skb);
452                         if (copied == 0)
453                                 copied = -EFAULT;
454                         break;
455                 }
456                 copied += chunk;
457                 size -= chunk;
458
459                 /* Mark read part of skb as used */
460                 if (!(flags & MSG_PEEK)) {
461                         skb_pull(skb, chunk);
462
463                         /* put the skb back if we didn't use it up. */
464                         if (skb->len) {
465                                 skb_queue_head(&sk->sk_receive_queue, skb);
466                                 break;
467                         }
468                         kfree_skb(skb);
469
470                 } else {
471                         /*
472                          * It is questionable, see note in unix_dgram_recvmsg.
473                          */
474                         /* put message back and return */
475                         skb_queue_head(&sk->sk_receive_queue, skb);
476                         break;
477                 }
478         } while (size);
479         caif_read_unlock(sk);
480
481 out:
482         return copied ? : err;
483 }
484
485 /*
486  * Copied from sock.c:sock_wait_for_wmem, but change to wait for
487  * CAIF flow-on and sock_writable.
488  */
489 static long caif_wait_for_flow_on(struct caifsock *cf_sk,
490                                 int wait_writeable, long timeo, int *err)
491 {
492         struct sock *sk = &cf_sk->sk;
493         DEFINE_WAIT(wait);
494         for (;;) {
495                 *err = 0;
496                 if (tx_flow_is_on(cf_sk) &&
497                         (!wait_writeable || sock_writeable(&cf_sk->sk)))
498                         break;
499                 *err = -ETIMEDOUT;
500                 if (!timeo)
501                         break;
502                 *err = -ERESTARTSYS;
503                 if (signal_pending(current))
504                         break;
505                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
506                 *err = -ECONNRESET;
507                 if (sk->sk_shutdown & SHUTDOWN_MASK)
508                         break;
509                 *err = -sk->sk_err;
510                 if (sk->sk_err)
511                         break;
512                 *err = -EPIPE;
513                 if (cf_sk->sk.sk_state != CAIF_CONNECTED)
514                         break;
515                 timeo = schedule_timeout(timeo);
516         }
517         finish_wait(sk_sleep(sk), &wait);
518         return timeo;
519 }
520
521 /*
522  * Transmit a SKB. The device may temporarily request re-transmission
523  * by returning EAGAIN.
524  */
525 static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk,
526                         int noblock, long timeo)
527 {
528         struct cfpkt *pkt;
529         int ret, loopcnt = 0;
530
531         pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb);
532         memset(cfpkt_info(pkt), 0, sizeof(struct caif_payload_info));
533         do {
534
535                 ret = -ETIMEDOUT;
536
537                 /* Slight paranoia, probably not needed. */
538                 if (unlikely(loopcnt++ > 1000)) {
539                         pr_warning("CAIF: %s(): transmit retries failed,"
540                                 " error = %d\n", __func__, ret);
541                         break;
542                 }
543
544                 if (cf_sk->layer.dn != NULL)
545                         ret = cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
546                 if (likely(ret >= 0))
547                         break;
548                 /* if transmit return -EAGAIN, then retry */
549                 if (noblock && ret == -EAGAIN)
550                         break;
551                 timeo = caif_wait_for_flow_on(cf_sk, 0, timeo, &ret);
552                 if (signal_pending(current)) {
553                         ret = sock_intr_errno(timeo);
554                         break;
555                 }
556                 if (ret)
557                         break;
558                 if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
559                         sock_flag(&cf_sk->sk, SOCK_DEAD) ||
560                         (cf_sk->sk.sk_shutdown & RCV_SHUTDOWN)) {
561                         ret = -EPIPE;
562                         cf_sk->sk.sk_err = EPIPE;
563                         break;
564                 }
565         } while (ret == -EAGAIN);
566         return ret;
567 }
568
569 /* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
570 static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock,
571                         struct msghdr *msg, size_t len)
572 {
573         struct sock *sk = sock->sk;
574         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
575         int buffer_size;
576         int ret = 0;
577         struct sk_buff *skb = NULL;
578         int noblock;
579         long timeo;
580         caif_assert(cf_sk);
581         ret = sock_error(sk);
582         if (ret)
583                 goto err;
584
585         ret = -EOPNOTSUPP;
586         if (msg->msg_flags&MSG_OOB)
587                 goto err;
588
589         ret = -EOPNOTSUPP;
590         if (msg->msg_namelen)
591                 goto err;
592
593         ret = -EINVAL;
594         if (unlikely(msg->msg_iov->iov_base == NULL))
595                 goto err;
596         noblock = msg->msg_flags & MSG_DONTWAIT;
597
598         timeo = sock_sndtimeo(sk, noblock);
599         timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
600                                 1, timeo, &ret);
601
602         if (ret)
603                 goto err;
604         ret = -EPIPE;
605         if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
606                 sock_flag(sk, SOCK_DEAD) ||
607                 (sk->sk_shutdown & RCV_SHUTDOWN))
608                 goto err;
609
610         /* Error if trying to write more than maximum frame size. */
611         ret = -EMSGSIZE;
612         if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM)
613                 goto err;
614
615         buffer_size = len + cf_sk->headroom + cf_sk->tailroom;
616
617         ret = -ENOMEM;
618         skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
619
620         if (!skb || skb_tailroom(skb) < buffer_size)
621                 goto err;
622
623         skb_reserve(skb, cf_sk->headroom);
624
625         ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
626
627         if (ret)
628                 goto err;
629         ret = transmit_skb(skb, cf_sk, noblock, timeo);
630         if (ret < 0)
631                 goto err;
632         return len;
633 err:
634         kfree_skb(skb);
635         return ret;
636 }
637
638 /*
639  * Copied from unix_stream_sendmsg and adapted to CAIF:
640  * Changed removed permission handling and added waiting for flow on
641  * and other minor adaptations.
642  */
643 static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
644                                 struct msghdr *msg, size_t len)
645 {
646         struct sock *sk = sock->sk;
647         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
648         int err, size;
649         struct sk_buff *skb;
650         int sent = 0;
651         long timeo;
652
653         err = -EOPNOTSUPP;
654         if (unlikely(msg->msg_flags&MSG_OOB))
655                 goto out_err;
656
657         if (unlikely(msg->msg_namelen))
658                 goto out_err;
659
660         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
661         timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
662
663         if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
664                 goto pipe_err;
665
666         while (sent < len) {
667
668                 size = len-sent;
669
670                 if (size > cf_sk->maxframe)
671                         size = cf_sk->maxframe;
672
673                 /* If size is more than half of sndbuf, chop up message */
674                 if (size > ((sk->sk_sndbuf >> 1) - 64))
675                         size = (sk->sk_sndbuf >> 1) - 64;
676
677                 if (size > SKB_MAX_ALLOC)
678                         size = SKB_MAX_ALLOC;
679
680                 skb = sock_alloc_send_skb(sk,
681                                         size + cf_sk->headroom +
682                                         cf_sk->tailroom,
683                                         msg->msg_flags&MSG_DONTWAIT,
684                                         &err);
685                 if (skb == NULL)
686                         goto out_err;
687
688                 skb_reserve(skb, cf_sk->headroom);
689                 /*
690                  *      If you pass two values to the sock_alloc_send_skb
691                  *      it tries to grab the large buffer with GFP_NOFS
692                  *      (which can fail easily), and if it fails grab the
693                  *      fallback size buffer which is under a page and will
694                  *      succeed. [Alan]
695                  */
696                 size = min_t(int, size, skb_tailroom(skb));
697
698                 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
699                 if (err) {
700                         kfree_skb(skb);
701                         goto out_err;
702                 }
703                 err = transmit_skb(skb, cf_sk,
704                                 msg->msg_flags&MSG_DONTWAIT, timeo);
705                 if (err < 0) {
706                         kfree_skb(skb);
707                         goto pipe_err;
708                 }
709                 sent += size;
710         }
711
712         return sent;
713
714 pipe_err:
715         if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
716                 send_sig(SIGPIPE, current, 0);
717         err = -EPIPE;
718 out_err:
719         return sent ? : err;
720 }
721
722 static int setsockopt(struct socket *sock,
723                         int lvl, int opt, char __user *ov, unsigned int ol)
724 {
725         struct sock *sk = sock->sk;
726         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
727         int prio, linksel;
728         struct ifreq ifreq;
729
730         if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
731                 return -ENOPROTOOPT;
732
733         switch (opt) {
734         case CAIFSO_LINK_SELECT:
735                 if (ol < sizeof(int))
736                         return -EINVAL;
737                 if (lvl != SOL_CAIF)
738                         goto bad_sol;
739                 if (copy_from_user(&linksel, ov, sizeof(int)))
740                         return -EINVAL;
741                 lock_sock(&(cf_sk->sk));
742                 cf_sk->conn_req.link_selector = linksel;
743                 release_sock(&cf_sk->sk);
744                 return 0;
745
746         case SO_PRIORITY:
747                 if (lvl != SOL_SOCKET)
748                         goto bad_sol;
749                 if (ol < sizeof(int))
750                         return -EINVAL;
751                 if (copy_from_user(&prio, ov, sizeof(int)))
752                         return -EINVAL;
753                 lock_sock(&(cf_sk->sk));
754                 cf_sk->conn_req.priority = prio;
755                 release_sock(&cf_sk->sk);
756                 return 0;
757
758         case SO_BINDTODEVICE:
759                 if (lvl != SOL_SOCKET)
760                         goto bad_sol;
761                 if (ol < sizeof(struct ifreq))
762                         return -EINVAL;
763                 if (copy_from_user(&ifreq, ov, sizeof(ifreq)))
764                         return -EFAULT;
765                 lock_sock(&(cf_sk->sk));
766                 strncpy(cf_sk->conn_req.link_name, ifreq.ifr_name,
767                         sizeof(cf_sk->conn_req.link_name));
768                 cf_sk->conn_req.link_name
769                         [sizeof(cf_sk->conn_req.link_name)-1] = 0;
770                 release_sock(&cf_sk->sk);
771                 return 0;
772
773         case CAIFSO_REQ_PARAM:
774                 if (lvl != SOL_CAIF)
775                         goto bad_sol;
776                 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
777                         return -ENOPROTOOPT;
778                 lock_sock(&(cf_sk->sk));
779                 cf_sk->conn_req.param.size = ol;
780                 if (ol > sizeof(cf_sk->conn_req.param.data) ||
781                         copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) {
782                         release_sock(&cf_sk->sk);
783                         return -EINVAL;
784                 }
785                 release_sock(&cf_sk->sk);
786                 return 0;
787
788         default:
789                 return -ENOPROTOOPT;
790         }
791
792         return 0;
793 bad_sol:
794         return -ENOPROTOOPT;
795
796 }
797
798 /*
799  * caif_connect() - Connect a CAIF Socket
800  * Copied and modified af_irda.c:irda_connect().
801  *
802  * Note : by consulting "errno", the user space caller may learn the cause
803  * of the failure. Most of them are visible in the function, others may come
804  * from subroutines called and are listed here :
805  *  o -EAFNOSUPPORT: bad socket family or type.
806  *  o -ESOCKTNOSUPPORT: bad socket type or protocol
807  *  o -EINVAL: bad socket address, or CAIF link type
808  *  o -ECONNREFUSED: remote end refused the connection.
809  *  o -EINPROGRESS: connect request sent but timed out (or non-blocking)
810  *  o -EISCONN: already connected.
811  *  o -ETIMEDOUT: Connection timed out (send timeout)
812  *  o -ENODEV: No link layer to send request
813  *  o -ECONNRESET: Received Shutdown indication or lost link layer
814  *  o -ENOMEM: Out of memory
815  *
816  *  State Strategy:
817  *  o sk_state: holds the CAIF_* protocol state, it's updated by
818  *      caif_ctrl_cb.
819  *  o sock->state: holds the SS_* socket state and is updated by connect and
820  *      disconnect.
821  */
822 static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
823                         int addr_len, int flags)
824 {
825         struct sock *sk = sock->sk;
826         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
827         long timeo;
828         int err;
829         int ifindex, headroom, tailroom;
830         struct net_device *dev;
831
832         lock_sock(sk);
833
834         err = -EAFNOSUPPORT;
835         if (uaddr->sa_family != AF_CAIF)
836                 goto out;
837
838         switch (sock->state) {
839         case SS_UNCONNECTED:
840                 /* Normal case, a fresh connect */
841                 caif_assert(sk->sk_state == CAIF_DISCONNECTED);
842                 break;
843         case SS_CONNECTING:
844                 switch (sk->sk_state) {
845                 case CAIF_CONNECTED:
846                         sock->state = SS_CONNECTED;
847                         err = -EISCONN;
848                         goto out;
849                 case CAIF_DISCONNECTED:
850                         /* Reconnect allowed */
851                         break;
852                 case CAIF_CONNECTING:
853                         err = -EALREADY;
854                         if (flags & O_NONBLOCK)
855                                 goto out;
856                         goto wait_connect;
857                 }
858                 break;
859         case SS_CONNECTED:
860                 caif_assert(sk->sk_state == CAIF_CONNECTED ||
861                                 sk->sk_state == CAIF_DISCONNECTED);
862                 if (sk->sk_shutdown & SHUTDOWN_MASK) {
863                         /* Allow re-connect after SHUTDOWN_IND */
864                         caif_disconnect_client(&cf_sk->layer);
865                         break;
866                 }
867                 /* No reconnect on a seqpacket socket */
868                 err = -EISCONN;
869                 goto out;
870         case SS_DISCONNECTING:
871         case SS_FREE:
872                 caif_assert(1); /*Should never happen */
873                 break;
874         }
875         sk->sk_state = CAIF_DISCONNECTED;
876         sock->state = SS_UNCONNECTED;
877         sk_stream_kill_queues(&cf_sk->sk);
878
879         err = -EINVAL;
880         if (addr_len != sizeof(struct sockaddr_caif))
881                 goto out;
882
883         memcpy(&cf_sk->conn_req.sockaddr, uaddr,
884                 sizeof(struct sockaddr_caif));
885
886         /* Move to connecting socket, start sending Connect Requests */
887         sock->state = SS_CONNECTING;
888         sk->sk_state = CAIF_CONNECTING;
889
890         dbfs_atomic_inc(&cnt.num_connect_req);
891         cf_sk->layer.receive = caif_sktrecv_cb;
892         err = caif_connect_client(&cf_sk->conn_req,
893                                 &cf_sk->layer, &ifindex, &headroom, &tailroom);
894         if (err < 0) {
895                 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
896                 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
897                 goto out;
898         }
899         dev = dev_get_by_index(sock_net(sk), ifindex);
900         cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom);
901         cf_sk->tailroom = tailroom;
902         cf_sk->maxframe = dev->mtu - (headroom + tailroom);
903         dev_put(dev);
904         if (cf_sk->maxframe < 1) {
905                 pr_warning("CAIF: %s(): CAIF Interface MTU too small (%d)\n",
906                         __func__, dev->mtu);
907                 err = -ENODEV;
908                 goto out;
909         }
910
911         err = -EINPROGRESS;
912 wait_connect:
913
914         if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
915                 goto out;
916
917         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
918
919         release_sock(sk);
920         err = -ERESTARTSYS;
921         timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
922                         sk->sk_state != CAIF_CONNECTING,
923                         timeo);
924         lock_sock(sk);
925         if (timeo < 0)
926                 goto out; /* -ERESTARTSYS */
927
928         err = -ETIMEDOUT;
929         if (timeo == 0 && sk->sk_state != CAIF_CONNECTED)
930                 goto out;
931         if (sk->sk_state != CAIF_CONNECTED) {
932                 sock->state = SS_UNCONNECTED;
933                 err = sock_error(sk);
934                 if (!err)
935                         err = -ECONNREFUSED;
936                 goto out;
937         }
938         sock->state = SS_CONNECTED;
939         err = 0;
940 out:
941         release_sock(sk);
942         return err;
943 }
944
945 /*
946  * caif_release() - Disconnect a CAIF Socket
947  * Copied and modified af_irda.c:irda_release().
948  */
949 static int caif_release(struct socket *sock)
950 {
951         struct sock *sk = sock->sk;
952         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
953         int res = 0;
954
955         if (!sk)
956                 return 0;
957
958         set_tx_flow_off(cf_sk);
959
960         /*
961          * Ensure that packets are not queued after this point in time.
962          * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
963          * this ensures no packets when sock is dead.
964          */
965         spin_lock(&sk->sk_receive_queue.lock);
966         sock_set_flag(sk, SOCK_DEAD);
967         spin_unlock(&sk->sk_receive_queue.lock);
968         sock->sk = NULL;
969
970         dbfs_atomic_inc(&cnt.num_disconnect);
971
972         if (cf_sk->debugfs_socket_dir != NULL)
973                 debugfs_remove_recursive(cf_sk->debugfs_socket_dir);
974
975         lock_sock(&(cf_sk->sk));
976         sk->sk_state = CAIF_DISCONNECTED;
977         sk->sk_shutdown = SHUTDOWN_MASK;
978
979         if (cf_sk->sk.sk_socket->state == SS_CONNECTED ||
980                 cf_sk->sk.sk_socket->state == SS_CONNECTING)
981                 res = caif_disconnect_client(&cf_sk->layer);
982
983         cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
984         wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP);
985
986         sock_orphan(sk);
987         cf_sk->layer.dn = NULL;
988         sk_stream_kill_queues(&cf_sk->sk);
989         release_sock(sk);
990         sock_put(sk);
991         return res;
992 }
993
994 /* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */
995 static unsigned int caif_poll(struct file *file,
996                                 struct socket *sock, poll_table *wait)
997 {
998         struct sock *sk = sock->sk;
999         unsigned int mask;
1000         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1001
1002         sock_poll_wait(file, sk_sleep(sk), wait);
1003         mask = 0;
1004
1005         /* exceptional events? */
1006         if (sk->sk_err)
1007                 mask |= POLLERR;
1008         if (sk->sk_shutdown == SHUTDOWN_MASK)
1009                 mask |= POLLHUP;
1010         if (sk->sk_shutdown & RCV_SHUTDOWN)
1011                 mask |= POLLRDHUP;
1012
1013         /* readable? */
1014         if (!skb_queue_empty(&sk->sk_receive_queue) ||
1015                 (sk->sk_shutdown & RCV_SHUTDOWN))
1016                 mask |= POLLIN | POLLRDNORM;
1017
1018         /*
1019          * we set writable also when the other side has shut down the
1020          * connection. This prevents stuck sockets.
1021          */
1022         if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
1023                 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1024
1025         return mask;
1026 }
1027
1028 static const struct proto_ops caif_seqpacket_ops = {
1029         .family = PF_CAIF,
1030         .owner = THIS_MODULE,
1031         .release = caif_release,
1032         .bind = sock_no_bind,
1033         .connect = caif_connect,
1034         .socketpair = sock_no_socketpair,
1035         .accept = sock_no_accept,
1036         .getname = sock_no_getname,
1037         .poll = caif_poll,
1038         .ioctl = sock_no_ioctl,
1039         .listen = sock_no_listen,
1040         .shutdown = sock_no_shutdown,
1041         .setsockopt = setsockopt,
1042         .getsockopt = sock_no_getsockopt,
1043         .sendmsg = caif_seqpkt_sendmsg,
1044         .recvmsg = caif_seqpkt_recvmsg,
1045         .mmap = sock_no_mmap,
1046         .sendpage = sock_no_sendpage,
1047 };
1048
1049 static const struct proto_ops caif_stream_ops = {
1050         .family = PF_CAIF,
1051         .owner = THIS_MODULE,
1052         .release = caif_release,
1053         .bind = sock_no_bind,
1054         .connect = caif_connect,
1055         .socketpair = sock_no_socketpair,
1056         .accept = sock_no_accept,
1057         .getname = sock_no_getname,
1058         .poll = caif_poll,
1059         .ioctl = sock_no_ioctl,
1060         .listen = sock_no_listen,
1061         .shutdown = sock_no_shutdown,
1062         .setsockopt = setsockopt,
1063         .getsockopt = sock_no_getsockopt,
1064         .sendmsg = caif_stream_sendmsg,
1065         .recvmsg = caif_stream_recvmsg,
1066         .mmap = sock_no_mmap,
1067         .sendpage = sock_no_sendpage,
1068 };
1069
1070 /* This function is called when a socket is finally destroyed. */
1071 static void caif_sock_destructor(struct sock *sk)
1072 {
1073         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1074         caif_assert(!atomic_read(&sk->sk_wmem_alloc));
1075         caif_assert(sk_unhashed(sk));
1076         caif_assert(!sk->sk_socket);
1077         if (!sock_flag(sk, SOCK_DEAD)) {
1078                 pr_info("Attempt to release alive CAIF socket: %p\n", sk);
1079                 return;
1080         }
1081         sk_stream_kill_queues(&cf_sk->sk);
1082         dbfs_atomic_dec(&cnt.caif_nr_socks);
1083 }
1084
1085 static int caif_create(struct net *net, struct socket *sock, int protocol,
1086                         int kern)
1087 {
1088         struct sock *sk = NULL;
1089         struct caifsock *cf_sk = NULL;
1090         static struct proto prot = {.name = "PF_CAIF",
1091                 .owner = THIS_MODULE,
1092                 .obj_size = sizeof(struct caifsock),
1093         };
1094
1095         if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
1096                 return -EPERM;
1097         /*
1098          * The sock->type specifies the socket type to use.
1099          * The CAIF socket is a packet stream in the sense
1100          * that it is packet based. CAIF trusts the reliability
1101          * of the link, no resending is implemented.
1102          */
1103         if (sock->type == SOCK_SEQPACKET)
1104                 sock->ops = &caif_seqpacket_ops;
1105         else if (sock->type == SOCK_STREAM)
1106                 sock->ops = &caif_stream_ops;
1107         else
1108                 return -ESOCKTNOSUPPORT;
1109
1110         if (protocol < 0 || protocol >= CAIFPROTO_MAX)
1111                 return -EPROTONOSUPPORT;
1112         /*
1113          * Set the socket state to unconnected.  The socket state
1114          * is really not used at all in the net/core or socket.c but the
1115          * initialization makes sure that sock->state is not uninitialized.
1116          */
1117         sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot);
1118         if (!sk)
1119                 return -ENOMEM;
1120
1121         cf_sk = container_of(sk, struct caifsock, sk);
1122
1123         /* Store the protocol */
1124         sk->sk_protocol = (unsigned char) protocol;
1125
1126         /* Sendbuf dictates the amount of outbound packets not yet sent */
1127         sk->sk_sndbuf = CAIF_DEF_SNDBUF;
1128         sk->sk_rcvbuf = CAIF_DEF_RCVBUF;
1129
1130         /*
1131          * Lock in order to try to stop someone from opening the socket
1132          * too early.
1133          */
1134         lock_sock(&(cf_sk->sk));
1135
1136         /* Initialize the nozero default sock structure data. */
1137         sock_init_data(sock, sk);
1138         sk->sk_destruct = caif_sock_destructor;
1139
1140         mutex_init(&cf_sk->readlock); /* single task reading lock */
1141         cf_sk->layer.ctrlcmd = caif_ctrl_cb;
1142         cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
1143         cf_sk->sk.sk_state = CAIF_DISCONNECTED;
1144
1145         set_tx_flow_off(cf_sk);
1146         set_rx_flow_on(cf_sk);
1147
1148         /* Set default options on configuration */
1149         cf_sk->conn_req.priority = CAIF_PRIO_NORMAL;
1150         cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1151         cf_sk->conn_req.protocol = protocol;
1152         /* Increase the number of sockets created. */
1153         dbfs_atomic_inc(&cnt.caif_nr_socks);
1154 #ifdef CONFIG_DEBUG_FS
1155         if (!IS_ERR(debugfsdir)) {
1156                 /* Fill in some information concerning the misc socket. */
1157                 snprintf(cf_sk->name, sizeof(cf_sk->name), "cfsk%d",
1158                                 atomic_read(&cnt.caif_nr_socks));
1159
1160                 cf_sk->debugfs_socket_dir =
1161                         debugfs_create_dir(cf_sk->name, debugfsdir);
1162                 debugfs_create_u32("sk_state", S_IRUSR | S_IWUSR,
1163                                 cf_sk->debugfs_socket_dir,
1164                                 (u32 *) &cf_sk->sk.sk_state);
1165                 debugfs_create_u32("flow_state", S_IRUSR | S_IWUSR,
1166                                 cf_sk->debugfs_socket_dir, &cf_sk->flow_state);
1167                 debugfs_create_u32("sk_rmem_alloc", S_IRUSR | S_IWUSR,
1168                                 cf_sk->debugfs_socket_dir,
1169                                 (u32 *) &cf_sk->sk.sk_rmem_alloc);
1170                 debugfs_create_u32("sk_wmem_alloc", S_IRUSR | S_IWUSR,
1171                                 cf_sk->debugfs_socket_dir,
1172                                 (u32 *) &cf_sk->sk.sk_wmem_alloc);
1173                 debugfs_create_u32("identity", S_IRUSR | S_IWUSR,
1174                                 cf_sk->debugfs_socket_dir,
1175                                 (u32 *) &cf_sk->layer.id);
1176         }
1177 #endif
1178         release_sock(&cf_sk->sk);
1179         return 0;
1180 }
1181
1182
1183 static struct net_proto_family caif_family_ops = {
1184         .family = PF_CAIF,
1185         .create = caif_create,
1186         .owner = THIS_MODULE,
1187 };
1188
1189 static int af_caif_init(void)
1190 {
1191         int err = sock_register(&caif_family_ops);
1192         if (!err)
1193                 return err;
1194         return 0;
1195 }
1196
1197 static int __init caif_sktinit_module(void)
1198 {
1199 #ifdef CONFIG_DEBUG_FS
1200         debugfsdir = debugfs_create_dir("caif_sk", NULL);
1201         if (!IS_ERR(debugfsdir)) {
1202                 debugfs_create_u32("num_sockets", S_IRUSR | S_IWUSR,
1203                                 debugfsdir,
1204                                 (u32 *) &cnt.caif_nr_socks);
1205                 debugfs_create_u32("num_connect_req", S_IRUSR | S_IWUSR,
1206                                 debugfsdir,
1207                                 (u32 *) &cnt.num_connect_req);
1208                 debugfs_create_u32("num_connect_resp", S_IRUSR | S_IWUSR,
1209                                 debugfsdir,
1210                                 (u32 *) &cnt.num_connect_resp);
1211                 debugfs_create_u32("num_connect_fail_resp", S_IRUSR | S_IWUSR,
1212                                 debugfsdir,
1213                                 (u32 *) &cnt.num_connect_fail_resp);
1214                 debugfs_create_u32("num_disconnect", S_IRUSR | S_IWUSR,
1215                                 debugfsdir,
1216                                 (u32 *) &cnt.num_disconnect);
1217                 debugfs_create_u32("num_remote_shutdown_ind",
1218                                 S_IRUSR | S_IWUSR, debugfsdir,
1219                                 (u32 *) &cnt.num_remote_shutdown_ind);
1220                 debugfs_create_u32("num_tx_flow_off_ind", S_IRUSR | S_IWUSR,
1221                                 debugfsdir,
1222                                 (u32 *) &cnt.num_tx_flow_off_ind);
1223                 debugfs_create_u32("num_tx_flow_on_ind", S_IRUSR | S_IWUSR,
1224                                 debugfsdir,
1225                                 (u32 *) &cnt.num_tx_flow_on_ind);
1226                 debugfs_create_u32("num_rx_flow_off", S_IRUSR | S_IWUSR,
1227                                 debugfsdir,
1228                                 (u32 *) &cnt.num_rx_flow_off);
1229                 debugfs_create_u32("num_rx_flow_on", S_IRUSR | S_IWUSR,
1230                                 debugfsdir,
1231                                 (u32 *) &cnt.num_rx_flow_on);
1232         }
1233 #endif
1234         return af_caif_init();
1235 }
1236
1237 static void __exit caif_sktexit_module(void)
1238 {
1239         sock_unregister(PF_CAIF);
1240         if (debugfsdir != NULL)
1241                 debugfs_remove_recursive(debugfsdir);
1242 }
1243 module_init(caif_sktinit_module);
1244 module_exit(caif_sktexit_module);