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Linux 3.3-rc6
[linux/fpc-iii.git] / net / caif / caif_socket.c
bloba97d97a3a512706a2e37ecf873407f9b87482409
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 kfree_skb(skb);
544 return -EINVAL;
545 }
546
547 return cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
548 }
549
550 /* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
551 static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock,
552 struct msghdr *msg, size_t len)
553 {
554 struct sock *sk = sock->sk;
555 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
556 int buffer_size;
557 int ret = 0;
558 struct sk_buff *skb = NULL;
559 int noblock;
560 long timeo;
561 caif_assert(cf_sk);
562 ret = sock_error(sk);
563 if (ret)
564 goto err;
565
566 ret = -EOPNOTSUPP;
567 if (msg->msg_flags&MSG_OOB)
568 goto err;
569
570 ret = -EOPNOTSUPP;
571 if (msg->msg_namelen)
572 goto err;
573
574 ret = -EINVAL;
575 if (unlikely(msg->msg_iov->iov_base == NULL))
576 goto err;
577 noblock = msg->msg_flags & MSG_DONTWAIT;
578
579 timeo = sock_sndtimeo(sk, noblock);
580 timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
581 1, timeo, &ret);
582
583 if (ret)
584 goto err;
585 ret = -EPIPE;
586 if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
587 sock_flag(sk, SOCK_DEAD) ||
588 (sk->sk_shutdown & RCV_SHUTDOWN))
589 goto err;
590
591 /* Error if trying to write more than maximum frame size. */
592 ret = -EMSGSIZE;
593 if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM)
594 goto err;
595
596 buffer_size = len + cf_sk->headroom + cf_sk->tailroom;
597
598 ret = -ENOMEM;
599 skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
600
601 if (!skb || skb_tailroom(skb) < buffer_size)
602 goto err;
603
604 skb_reserve(skb, cf_sk->headroom);
605
606 ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
607
608 if (ret)
609 goto err;
610 ret = transmit_skb(skb, cf_sk, noblock, timeo);
611 if (ret < 0)
612 /* skb is already freed */
613 return ret;
614
615 return len;
616 err:
617 kfree_skb(skb);
618 return ret;
619 }
620
621 /*
622 * Copied from unix_stream_sendmsg and adapted to CAIF:
623 * Changed removed permission handling and added waiting for flow on
624 * and other minor adaptations.
625 */
626 static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
627 struct msghdr *msg, size_t len)
628 {
629 struct sock *sk = sock->sk;
630 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
631 int err, size;
632 struct sk_buff *skb;
633 int sent = 0;
634 long timeo;
635
636 err = -EOPNOTSUPP;
637 if (unlikely(msg->msg_flags&MSG_OOB))
638 goto out_err;
639
640 if (unlikely(msg->msg_namelen))
641 goto out_err;
642
643 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
644 timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
645
646 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
647 goto pipe_err;
648
649 while (sent < len) {
650
651 size = len-sent;
652
653 if (size > cf_sk->maxframe)
654 size = cf_sk->maxframe;
655
656 /* If size is more than half of sndbuf, chop up message */
657 if (size > ((sk->sk_sndbuf >> 1) - 64))
658 size = (sk->sk_sndbuf >> 1) - 64;
659
660 if (size > SKB_MAX_ALLOC)
661 size = SKB_MAX_ALLOC;
662
663 skb = sock_alloc_send_skb(sk,
664 size + cf_sk->headroom +
665 cf_sk->tailroom,
666 msg->msg_flags&MSG_DONTWAIT,
667 &err);
668 if (skb == NULL)
669 goto out_err;
670
671 skb_reserve(skb, cf_sk->headroom);
672 /*
673 * If you pass two values to the sock_alloc_send_skb
674 * it tries to grab the large buffer with GFP_NOFS
675 * (which can fail easily), and if it fails grab the
676 * fallback size buffer which is under a page and will
677 * succeed. [Alan]
678 */
679 size = min_t(int, size, skb_tailroom(skb));
680
681 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
682 if (err) {
683 kfree_skb(skb);
684 goto out_err;
685 }
686 err = transmit_skb(skb, cf_sk,
687 msg->msg_flags&MSG_DONTWAIT, timeo);
688 if (err < 0)
689 /* skb is already freed */
690 goto pipe_err;
691
692 sent += size;
693 }
694
695 return sent;
696
697 pipe_err:
698 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
699 send_sig(SIGPIPE, current, 0);
700 err = -EPIPE;
701 out_err:
702 return sent ? : err;
703 }
704
705 static int setsockopt(struct socket *sock,
706 int lvl, int opt, char __user *ov, unsigned int ol)
707 {
708 struct sock *sk = sock->sk;
709 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
710 int linksel;
711
712 if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
713 return -ENOPROTOOPT;
714
715 switch (opt) {
716 case CAIFSO_LINK_SELECT:
717 if (ol < sizeof(int))
718 return -EINVAL;
719 if (lvl != SOL_CAIF)
720 goto bad_sol;
721 if (copy_from_user(&linksel, ov, sizeof(int)))
722 return -EINVAL;
723 lock_sock(&(cf_sk->sk));
724 cf_sk->conn_req.link_selector = linksel;
725 release_sock(&cf_sk->sk);
726 return 0;
727
728 case CAIFSO_REQ_PARAM:
729 if (lvl != SOL_CAIF)
730 goto bad_sol;
731 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
732 return -ENOPROTOOPT;
733 lock_sock(&(cf_sk->sk));
734 if (ol > sizeof(cf_sk->conn_req.param.data) ||
735 copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) {
736 release_sock(&cf_sk->sk);
737 return -EINVAL;
738 }
739 cf_sk->conn_req.param.size = ol;
740 release_sock(&cf_sk->sk);
741 return 0;
742
743 default:
744 return -ENOPROTOOPT;
745 }
746
747 return 0;
748 bad_sol:
749 return -ENOPROTOOPT;
750
751 }
752
753 /*
754 * caif_connect() - Connect a CAIF Socket
755 * Copied and modified af_irda.c:irda_connect().
756 *
757 * Note : by consulting "errno", the user space caller may learn the cause
758 * of the failure. Most of them are visible in the function, others may come
759 * from subroutines called and are listed here :
760 * o -EAFNOSUPPORT: bad socket family or type.
761 * o -ESOCKTNOSUPPORT: bad socket type or protocol
762 * o -EINVAL: bad socket address, or CAIF link type
763 * o -ECONNREFUSED: remote end refused the connection.
764 * o -EINPROGRESS: connect request sent but timed out (or non-blocking)
765 * o -EISCONN: already connected.
766 * o -ETIMEDOUT: Connection timed out (send timeout)
767 * o -ENODEV: No link layer to send request
768 * o -ECONNRESET: Received Shutdown indication or lost link layer
769 * o -ENOMEM: Out of memory
770 *
771 * State Strategy:
772 * o sk_state: holds the CAIF_* protocol state, it's updated by
773 * caif_ctrl_cb.
774 * o sock->state: holds the SS_* socket state and is updated by connect and
775 * disconnect.
776 */
777 static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
778 int addr_len, int flags)
779 {
780 struct sock *sk = sock->sk;
781 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
782 long timeo;
783 int err;
784 int ifindex, headroom, tailroom;
785 unsigned int mtu;
786 struct net_device *dev;
787
788 lock_sock(sk);
789
790 err = -EAFNOSUPPORT;
791 if (uaddr->sa_family != AF_CAIF)
792 goto out;
793
794 switch (sock->state) {
795 case SS_UNCONNECTED:
796 /* Normal case, a fresh connect */
797 caif_assert(sk->sk_state == CAIF_DISCONNECTED);
798 break;
799 case SS_CONNECTING:
800 switch (sk->sk_state) {
801 case CAIF_CONNECTED:
802 sock->state = SS_CONNECTED;
803 err = -EISCONN;
804 goto out;
805 case CAIF_DISCONNECTED:
806 /* Reconnect allowed */
807 break;
808 case CAIF_CONNECTING:
809 err = -EALREADY;
810 if (flags & O_NONBLOCK)
811 goto out;
812 goto wait_connect;
813 }
814 break;
815 case SS_CONNECTED:
816 caif_assert(sk->sk_state == CAIF_CONNECTED ||
817 sk->sk_state == CAIF_DISCONNECTED);
818 if (sk->sk_shutdown & SHUTDOWN_MASK) {
819 /* Allow re-connect after SHUTDOWN_IND */
820 caif_disconnect_client(sock_net(sk), &cf_sk->layer);
821 caif_free_client(&cf_sk->layer);
822 break;
823 }
824 /* No reconnect on a seqpacket socket */
825 err = -EISCONN;
826 goto out;
827 case SS_DISCONNECTING:
828 case SS_FREE:
829 caif_assert(1); /*Should never happen */
830 break;
831 }
832 sk->sk_state = CAIF_DISCONNECTED;
833 sock->state = SS_UNCONNECTED;
834 sk_stream_kill_queues(&cf_sk->sk);
835
836 err = -EINVAL;
837 if (addr_len != sizeof(struct sockaddr_caif))
838 goto out;
839
840 memcpy(&cf_sk->conn_req.sockaddr, uaddr,
841 sizeof(struct sockaddr_caif));
842
843 /* Move to connecting socket, start sending Connect Requests */
844 sock->state = SS_CONNECTING;
845 sk->sk_state = CAIF_CONNECTING;
846
847 /* Check priority value comming from socket */
848 /* if priority value is out of range it will be ajusted */
849 if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX)
850 cf_sk->conn_req.priority = CAIF_PRIO_MAX;
851 else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN)
852 cf_sk->conn_req.priority = CAIF_PRIO_MIN;
853 else
854 cf_sk->conn_req.priority = cf_sk->sk.sk_priority;
855
856 /*ifindex = id of the interface.*/
857 cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if;
858
859 dbfs_atomic_inc(&cnt.num_connect_req);
860 cf_sk->layer.receive = caif_sktrecv_cb;
861
862 err = caif_connect_client(sock_net(sk), &cf_sk->conn_req,
863 &cf_sk->layer, &ifindex, &headroom, &tailroom);
864
865 if (err < 0) {
866 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
867 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
868 goto out;
869 }
870
871 err = -ENODEV;
872 rcu_read_lock();
873 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
874 if (!dev) {
875 rcu_read_unlock();
876 goto out;
877 }
878 cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom);
879 mtu = dev->mtu;
880 rcu_read_unlock();
881
882 cf_sk->tailroom = tailroom;
883 cf_sk->maxframe = mtu - (headroom + tailroom);
884 if (cf_sk->maxframe < 1) {
885 pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu);
886 err = -ENODEV;
887 goto out;
888 }
889
890 err = -EINPROGRESS;
891 wait_connect:
892
893 if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
894 goto out;
895
896 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
897
898 release_sock(sk);
899 err = -ERESTARTSYS;
900 timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
901 sk->sk_state != CAIF_CONNECTING,
902 timeo);
903 lock_sock(sk);
904 if (timeo < 0)
905 goto out; /* -ERESTARTSYS */
906
907 err = -ETIMEDOUT;
908 if (timeo == 0 && sk->sk_state != CAIF_CONNECTED)
909 goto out;
910 if (sk->sk_state != CAIF_CONNECTED) {
911 sock->state = SS_UNCONNECTED;
912 err = sock_error(sk);
913 if (!err)
914 err = -ECONNREFUSED;
915 goto out;
916 }
917 sock->state = SS_CONNECTED;
918 err = 0;
919 out:
920 release_sock(sk);
921 return err;
922 }
923
924 /*
925 * caif_release() - Disconnect a CAIF Socket
926 * Copied and modified af_irda.c:irda_release().
927 */
928 static int caif_release(struct socket *sock)
929 {
930 struct sock *sk = sock->sk;
931 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
932
933 if (!sk)
934 return 0;
935
936 set_tx_flow_off(cf_sk);
937
938 /*
939 * Ensure that packets are not queued after this point in time.
940 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
941 * this ensures no packets when sock is dead.
942 */
943 spin_lock_bh(&sk->sk_receive_queue.lock);
944 sock_set_flag(sk, SOCK_DEAD);
945 spin_unlock_bh(&sk->sk_receive_queue.lock);
946 sock->sk = NULL;
947
948 dbfs_atomic_inc(&cnt.num_disconnect);
949
950 WARN_ON(IS_ERR(cf_sk->debugfs_socket_dir));
951 if (cf_sk->debugfs_socket_dir != NULL)
952 debugfs_remove_recursive(cf_sk->debugfs_socket_dir);
953
954 lock_sock(&(cf_sk->sk));
955 sk->sk_state = CAIF_DISCONNECTED;
956 sk->sk_shutdown = SHUTDOWN_MASK;
957
958 caif_disconnect_client(sock_net(sk), &cf_sk->layer);
959 cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
960 wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP);
961
962 sock_orphan(sk);
963 sk_stream_kill_queues(&cf_sk->sk);
964 release_sock(sk);
965 sock_put(sk);
966 return 0;
967 }
968
969 /* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */
970 static unsigned int caif_poll(struct file *file,
971 struct socket *sock, poll_table *wait)
972 {
973 struct sock *sk = sock->sk;
974 unsigned int mask;
975 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
976
977 sock_poll_wait(file, sk_sleep(sk), wait);
978 mask = 0;
979
980 /* exceptional events? */
981 if (sk->sk_err)
982 mask |= POLLERR;
983 if (sk->sk_shutdown == SHUTDOWN_MASK)
984 mask |= POLLHUP;
985 if (sk->sk_shutdown & RCV_SHUTDOWN)
986 mask |= POLLRDHUP;
987
988 /* readable? */
989 if (!skb_queue_empty(&sk->sk_receive_queue) ||
990 (sk->sk_shutdown & RCV_SHUTDOWN))
991 mask |= POLLIN | POLLRDNORM;
992
993 /*
994 * we set writable also when the other side has shut down the
995 * connection. This prevents stuck sockets.
996 */
997 if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
998 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
999
1000 return mask;
1001 }
1002
1003 static const struct proto_ops caif_seqpacket_ops = {
1004 .family = PF_CAIF,
1005 .owner = THIS_MODULE,
1006 .release = caif_release,
1007 .bind = sock_no_bind,
1008 .connect = caif_connect,
1009 .socketpair = sock_no_socketpair,
1010 .accept = sock_no_accept,
1011 .getname = sock_no_getname,
1012 .poll = caif_poll,
1013 .ioctl = sock_no_ioctl,
1014 .listen = sock_no_listen,
1015 .shutdown = sock_no_shutdown,
1016 .setsockopt = setsockopt,
1017 .getsockopt = sock_no_getsockopt,
1018 .sendmsg = caif_seqpkt_sendmsg,
1019 .recvmsg = caif_seqpkt_recvmsg,
1020 .mmap = sock_no_mmap,
1021 .sendpage = sock_no_sendpage,
1022 };
1023
1024 static const struct proto_ops caif_stream_ops = {
1025 .family = PF_CAIF,
1026 .owner = THIS_MODULE,
1027 .release = caif_release,
1028 .bind = sock_no_bind,
1029 .connect = caif_connect,
1030 .socketpair = sock_no_socketpair,
1031 .accept = sock_no_accept,
1032 .getname = sock_no_getname,
1033 .poll = caif_poll,
1034 .ioctl = sock_no_ioctl,
1035 .listen = sock_no_listen,
1036 .shutdown = sock_no_shutdown,
1037 .setsockopt = setsockopt,
1038 .getsockopt = sock_no_getsockopt,
1039 .sendmsg = caif_stream_sendmsg,
1040 .recvmsg = caif_stream_recvmsg,
1041 .mmap = sock_no_mmap,
1042 .sendpage = sock_no_sendpage,
1043 };
1044
1045 /* This function is called when a socket is finally destroyed. */
1046 static void caif_sock_destructor(struct sock *sk)
1047 {
1048 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1049 caif_assert(!atomic_read(&sk->sk_wmem_alloc));
1050 caif_assert(sk_unhashed(sk));
1051 caif_assert(!sk->sk_socket);
1052 if (!sock_flag(sk, SOCK_DEAD)) {
1053 pr_debug("Attempt to release alive CAIF socket: %p\n", sk);
1054 return;
1055 }
1056 sk_stream_kill_queues(&cf_sk->sk);
1057 dbfs_atomic_dec(&cnt.caif_nr_socks);
1058 caif_free_client(&cf_sk->layer);
1059 }
1060
1061 static int caif_create(struct net *net, struct socket *sock, int protocol,
1062 int kern)
1063 {
1064 int num;
1065 struct sock *sk = NULL;
1066 struct caifsock *cf_sk = NULL;
1067 static struct proto prot = {.name = "PF_CAIF",
1068 .owner = THIS_MODULE,
1069 .obj_size = sizeof(struct caifsock),
1070 };
1071
1072 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
1073 return -EPERM;
1074 /*
1075 * The sock->type specifies the socket type to use.
1076 * The CAIF socket is a packet stream in the sense
1077 * that it is packet based. CAIF trusts the reliability
1078 * of the link, no resending is implemented.
1079 */
1080 if (sock->type == SOCK_SEQPACKET)
1081 sock->ops = &caif_seqpacket_ops;
1082 else if (sock->type == SOCK_STREAM)
1083 sock->ops = &caif_stream_ops;
1084 else
1085 return -ESOCKTNOSUPPORT;
1086
1087 if (protocol < 0 || protocol >= CAIFPROTO_MAX)
1088 return -EPROTONOSUPPORT;
1089 /*
1090 * Set the socket state to unconnected. The socket state
1091 * is really not used at all in the net/core or socket.c but the
1092 * initialization makes sure that sock->state is not uninitialized.
1093 */
1094 sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot);
1095 if (!sk)
1096 return -ENOMEM;
1097
1098 cf_sk = container_of(sk, struct caifsock, sk);
1099
1100 /* Store the protocol */
1101 sk->sk_protocol = (unsigned char) protocol;
1102
1103 /*
1104 * Lock in order to try to stop someone from opening the socket
1105 * too early.
1106 */
1107 lock_sock(&(cf_sk->sk));
1108
1109 /* Initialize the nozero default sock structure data. */
1110 sock_init_data(sock, sk);
1111 sk->sk_destruct = caif_sock_destructor;
1112
1113 mutex_init(&cf_sk->readlock); /* single task reading lock */
1114 cf_sk->layer.ctrlcmd = caif_ctrl_cb;
1115 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
1116 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
1117
1118 set_tx_flow_off(cf_sk);
1119 set_rx_flow_on(cf_sk);
1120
1121 /* Set default options on configuration */
1122 cf_sk->sk.sk_priority = CAIF_PRIO_NORMAL;
1123 cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1124 cf_sk->conn_req.protocol = protocol;
1125 /* Increase the number of sockets created. */
1126 dbfs_atomic_inc(&cnt.caif_nr_socks);
1127 num = dbfs_atomic_inc(&cnt.caif_sock_create);
1128 #ifdef CONFIG_DEBUG_FS
1129 if (!IS_ERR(debugfsdir)) {
1130
1131 /* Fill in some information concerning the misc socket. */
1132 snprintf(cf_sk->name, sizeof(cf_sk->name), "cfsk%d", num);
1133
1134 cf_sk->debugfs_socket_dir =
1135 debugfs_create_dir(cf_sk->name, debugfsdir);
1136
1137 debugfs_create_u32("sk_state", S_IRUSR | S_IWUSR,
1138 cf_sk->debugfs_socket_dir,
1139 (u32 *) &cf_sk->sk.sk_state);
1140 debugfs_create_u32("flow_state", S_IRUSR | S_IWUSR,
1141 cf_sk->debugfs_socket_dir, &cf_sk->flow_state);
1142 debugfs_create_u32("sk_rmem_alloc", S_IRUSR | S_IWUSR,
1143 cf_sk->debugfs_socket_dir,
1144 (u32 *) &cf_sk->sk.sk_rmem_alloc);
1145 debugfs_create_u32("sk_wmem_alloc", S_IRUSR | S_IWUSR,
1146 cf_sk->debugfs_socket_dir,
1147 (u32 *) &cf_sk->sk.sk_wmem_alloc);
1148 debugfs_create_u32("identity", S_IRUSR | S_IWUSR,
1149 cf_sk->debugfs_socket_dir,
1150 (u32 *) &cf_sk->layer.id);
1151 }
1152 #endif
1153 release_sock(&cf_sk->sk);
1154 return 0;
1155 }
1156
1157
1158 static struct net_proto_family caif_family_ops = {
1159 .family = PF_CAIF,
1160 .create = caif_create,
1161 .owner = THIS_MODULE,
1162 };
1163
1164 static int af_caif_init(void)
1165 {
1166 int err = sock_register(&caif_family_ops);
1167 if (!err)
1168 return err;
1169 return 0;
1170 }
1171
1172 static int __init caif_sktinit_module(void)
1173 {
1174 #ifdef CONFIG_DEBUG_FS
1175 debugfsdir = debugfs_create_dir("caif_sk", NULL);
1176 if (!IS_ERR(debugfsdir)) {
1177 debugfs_create_u32("num_sockets", S_IRUSR | S_IWUSR,
1178 debugfsdir,
1179 (u32 *) &cnt.caif_nr_socks);
1180 debugfs_create_u32("num_create", S_IRUSR | S_IWUSR,
1181 debugfsdir,
1182 (u32 *) &cnt.caif_sock_create);
1183 debugfs_create_u32("num_connect_req", S_IRUSR | S_IWUSR,
1184 debugfsdir,
1185 (u32 *) &cnt.num_connect_req);
1186 debugfs_create_u32("num_connect_resp", S_IRUSR | S_IWUSR,
1187 debugfsdir,
1188 (u32 *) &cnt.num_connect_resp);
1189 debugfs_create_u32("num_connect_fail_resp", S_IRUSR | S_IWUSR,
1190 debugfsdir,
1191 (u32 *) &cnt.num_connect_fail_resp);
1192 debugfs_create_u32("num_disconnect", S_IRUSR | S_IWUSR,
1193 debugfsdir,
1194 (u32 *) &cnt.num_disconnect);
1195 debugfs_create_u32("num_remote_shutdown_ind",
1196 S_IRUSR | S_IWUSR, debugfsdir,
1197 (u32 *) &cnt.num_remote_shutdown_ind);
1198 debugfs_create_u32("num_tx_flow_off_ind", S_IRUSR | S_IWUSR,
1199 debugfsdir,
1200 (u32 *) &cnt.num_tx_flow_off_ind);
1201 debugfs_create_u32("num_tx_flow_on_ind", S_IRUSR | S_IWUSR,
1202 debugfsdir,
1203 (u32 *) &cnt.num_tx_flow_on_ind);
1204 debugfs_create_u32("num_rx_flow_off", S_IRUSR | S_IWUSR,
1205 debugfsdir,
1206 (u32 *) &cnt.num_rx_flow_off);
1207 debugfs_create_u32("num_rx_flow_on", S_IRUSR | S_IWUSR,
1208 debugfsdir,
1209 (u32 *) &cnt.num_rx_flow_on);
1210 }
1211 #endif
1212 return af_caif_init();
1213 }
1214
1215 static void __exit caif_sktexit_module(void)
1216 {
1217 sock_unregister(PF_CAIF);
1218 if (debugfsdir != NULL)
1219 debugfs_remove_recursive(debugfsdir);
1220 }
1221 module_init(caif_sktinit_module);
1222 module_exit(caif_sktexit_module);
Linux with added FPC-III support