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reiserfs: Fix resuming of quotas on remount read-write
[linux-2.6/btrfs-unstable.git] / net / caif / caif_socket.c
blobc3a70c5c893a8efe0603b5e4a82a4e4ae515b10f
1 /*
2 * Copyright (C) ST-Ericsson AB 2010
3 * Author: Sjur Brendeland sjur.brandeland@stericsson.com
4 * License terms: GNU General Public License (GPL) version 2
5 */
6
7 #include <linux/fs.h>
8 #include <linux/init.h>
9 #include <linux/module.h>
10 #include <linux/sched.h>
11 #include <linux/spinlock.h>
12 #include <linux/mutex.h>
13 #include <linux/list.h>
14 #include <linux/wait.h>
15 #include <linux/poll.h>
16 #include <linux/tcp.h>
17 #include <linux/uaccess.h>
18 #include <linux/mutex.h>
19 #include <linux/debugfs.h>
20 #include <linux/caif/caif_socket.h>
21 #include <asm/atomic.h>
22 #include <net/sock.h>
23 #include <net/tcp_states.h>
24 #include <net/caif/caif_layer.h>
25 #include <net/caif/caif_dev.h>
26 #include <net/caif/cfpkt.h>
27
28 MODULE_LICENSE("GPL");
29 MODULE_ALIAS_NETPROTO(AF_CAIF);
30
31 #define CAIF_DEF_SNDBUF (CAIF_MAX_PAYLOAD_SIZE*10)
32 #define CAIF_DEF_RCVBUF (CAIF_MAX_PAYLOAD_SIZE*100)
33
34 /*
35 * CAIF state is re-using the TCP socket states.
36 * caif_states stored in sk_state reflect the state as reported by
37 * the CAIF stack, while sk_socket->state is the state of the socket.
38 */
39 enum caif_states {
40 CAIF_CONNECTED = TCP_ESTABLISHED,
41 CAIF_CONNECTING = TCP_SYN_SENT,
42 CAIF_DISCONNECTED = TCP_CLOSE
43 };
44
45 #define TX_FLOW_ON_BIT 1
46 #define RX_FLOW_ON_BIT 2
47
48 static struct dentry *debugfsdir;
49
50 #ifdef CONFIG_DEBUG_FS
51 struct debug_fs_counter {
52 atomic_t caif_nr_socks;
53 atomic_t num_connect_req;
54 atomic_t num_connect_resp;
55 atomic_t num_connect_fail_resp;
56 atomic_t num_disconnect;
57 atomic_t num_remote_shutdown_ind;
58 atomic_t num_tx_flow_off_ind;
59 atomic_t num_tx_flow_on_ind;
60 atomic_t num_rx_flow_off;
61 atomic_t num_rx_flow_on;
62 };
63 struct debug_fs_counter cnt;
64 #define dbfs_atomic_inc(v) atomic_inc(v)
65 #define dbfs_atomic_dec(v) atomic_dec(v)
66 #else
67 #define dbfs_atomic_inc(v)
68 #define dbfs_atomic_dec(v)
69 #endif
70
71 struct caifsock {
72 struct sock sk; /* must be first member */
73 struct cflayer layer;
74 char name[CAIF_LAYER_NAME_SZ]; /* Used for debugging */
75 u32 flow_state;
76 struct caif_connect_request conn_req;
77 struct mutex readlock;
78 struct dentry *debugfs_socket_dir;
79 };
80
81 static int rx_flow_is_on(struct caifsock *cf_sk)
82 {
83 return test_bit(RX_FLOW_ON_BIT,
84 (void *) &cf_sk->flow_state);
85 }
86
87 static int tx_flow_is_on(struct caifsock *cf_sk)
88 {
89 return test_bit(TX_FLOW_ON_BIT,
90 (void *) &cf_sk->flow_state);
91 }
92
93 static void set_rx_flow_off(struct caifsock *cf_sk)
94 {
95 clear_bit(RX_FLOW_ON_BIT,
96 (void *) &cf_sk->flow_state);
97 }
98
99 static void set_rx_flow_on(struct caifsock *cf_sk)
100 {
101 set_bit(RX_FLOW_ON_BIT,
102 (void *) &cf_sk->flow_state);
103 }
104
105 static void set_tx_flow_off(struct caifsock *cf_sk)
106 {
107 clear_bit(TX_FLOW_ON_BIT,
108 (void *) &cf_sk->flow_state);
109 }
110
111 static void set_tx_flow_on(struct caifsock *cf_sk)
112 {
113 set_bit(TX_FLOW_ON_BIT,
114 (void *) &cf_sk->flow_state);
115 }
116
117 static void caif_read_lock(struct sock *sk)
118 {
119 struct caifsock *cf_sk;
120 cf_sk = container_of(sk, struct caifsock, sk);
121 mutex_lock(&cf_sk->readlock);
122 }
123
124 static void caif_read_unlock(struct sock *sk)
125 {
126 struct caifsock *cf_sk;
127 cf_sk = container_of(sk, struct caifsock, sk);
128 mutex_unlock(&cf_sk->readlock);
129 }
130
131 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 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)
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 int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
150 {
151 int err;
152 int skb_len;
153 unsigned long flags;
154 struct sk_buff_head *list = &sk->sk_receive_queue;
155 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
156
157 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
158 (unsigned)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) {
159 trace_printk("CAIF: %s():"
160 " sending flow OFF (queue len = %d %d)\n",
161 __func__,
162 atomic_read(&cf_sk->sk.sk_rmem_alloc),
163 sk_rcvbuf_lowwater(cf_sk));
164 set_rx_flow_off(cf_sk);
165 if (cf_sk->layer.dn)
166 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn,
167 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 if (cf_sk->layer.dn)
179 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn,
180 CAIF_MODEMCMD_FLOW_OFF_REQ);
181 }
182 skb->dev = NULL;
183 skb_set_owner_r(skb, sk);
184 /* Cache the SKB length before we tack it onto the receive
185 * queue. Once it is added it no longer belongs to us and
186 * may be freed by other threads of control pulling packets
187 * from the queue.
188 */
189 skb_len = skb->len;
190 spin_lock_irqsave(&list->lock, flags);
191 if (!sock_flag(sk, SOCK_DEAD))
192 __skb_queue_tail(list, skb);
193 spin_unlock_irqrestore(&list->lock, flags);
194
195 if (!sock_flag(sk, SOCK_DEAD))
196 sk->sk_data_ready(sk, skb_len);
197 else
198 kfree_skb(skb);
199 return 0;
200 }
201
202 /* Packet Receive Callback function called from CAIF Stack */
203 static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
204 {
205 struct caifsock *cf_sk;
206 struct sk_buff *skb;
207
208 cf_sk = container_of(layr, struct caifsock, layer);
209 skb = cfpkt_tonative(pkt);
210
211 if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) {
212 cfpkt_destroy(pkt);
213 return 0;
214 }
215 caif_queue_rcv_skb(&cf_sk->sk, skb);
216 return 0;
217 }
218
219 /* Packet Control Callback function called from CAIF */
220 static void caif_ctrl_cb(struct cflayer *layr,
221 enum caif_ctrlcmd flow,
222 int phyid)
223 {
224 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
225 switch (flow) {
226 case CAIF_CTRLCMD_FLOW_ON_IND:
227 /* OK from modem to start sending again */
228 dbfs_atomic_inc(&cnt.num_tx_flow_on_ind);
229 set_tx_flow_on(cf_sk);
230 cf_sk->sk.sk_state_change(&cf_sk->sk);
231 break;
232
233 case CAIF_CTRLCMD_FLOW_OFF_IND:
234 /* Modem asks us to shut up */
235 dbfs_atomic_inc(&cnt.num_tx_flow_off_ind);
236 set_tx_flow_off(cf_sk);
237 cf_sk->sk.sk_state_change(&cf_sk->sk);
238 break;
239
240 case CAIF_CTRLCMD_INIT_RSP:
241 /* We're now connected */
242 dbfs_atomic_inc(&cnt.num_connect_resp);
243 cf_sk->sk.sk_state = CAIF_CONNECTED;
244 set_tx_flow_on(cf_sk);
245 cf_sk->sk.sk_state_change(&cf_sk->sk);
246 break;
247
248 case CAIF_CTRLCMD_DEINIT_RSP:
249 /* We're now disconnected */
250 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
251 cf_sk->sk.sk_state_change(&cf_sk->sk);
252 cfcnfg_release_adap_layer(&cf_sk->layer);
253 break;
254
255 case CAIF_CTRLCMD_INIT_FAIL_RSP:
256 /* Connect request failed */
257 dbfs_atomic_inc(&cnt.num_connect_fail_resp);
258 cf_sk->sk.sk_err = ECONNREFUSED;
259 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
260 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
261 /*
262 * Socket "standards" seems to require POLLOUT to
263 * be set at connect failure.
264 */
265 set_tx_flow_on(cf_sk);
266 cf_sk->sk.sk_state_change(&cf_sk->sk);
267 break;
268
269 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
270 /* Modem has closed this connection, or device is down. */
271 dbfs_atomic_inc(&cnt.num_remote_shutdown_ind);
272 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
273 cf_sk->sk.sk_err = ECONNRESET;
274 set_rx_flow_on(cf_sk);
275 cf_sk->sk.sk_error_report(&cf_sk->sk);
276 break;
277
278 default:
279 pr_debug("CAIF: %s(): Unexpected flow command %d\n",
280 __func__, flow);
281 }
282 }
283
284 static void caif_check_flow_release(struct sock *sk)
285 {
286 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
287
288 if (cf_sk->layer.dn == NULL || cf_sk->layer.dn->modemcmd == NULL)
289 return;
290 if (rx_flow_is_on(cf_sk))
291 return;
292
293 if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) {
294 dbfs_atomic_inc(&cnt.num_rx_flow_on);
295 set_rx_flow_on(cf_sk);
296 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn,
297 CAIF_MODEMCMD_FLOW_ON_REQ);
298 }
299 }
300 /*
301 * Copied from sock.c:sock_queue_rcv_skb(), and added check that user buffer
302 * has sufficient size.
303 */
304
305 static int caif_seqpkt_recvmsg(struct kiocb *iocb, struct socket *sock,
306 struct msghdr *m, size_t buf_len, int flags)
307
308 {
309 struct sock *sk = sock->sk;
310 struct sk_buff *skb;
311 int ret = 0;
312 int len;
313
314 if (unlikely(!buf_len))
315 return -EINVAL;
316
317 skb = skb_recv_datagram(sk, flags, 0 , &ret);
318 if (!skb)
319 goto read_error;
320
321 len = skb->len;
322
323 if (skb && skb->len > buf_len && !(flags & MSG_PEEK)) {
324 len = buf_len;
325 /*
326 * Push skb back on receive queue if buffer too small.
327 * This has a built-in race where multi-threaded receive
328 * may get packet in wrong order, but multiple read does
329 * not really guarantee ordered delivery anyway.
330 * Let's optimize for speed without taking locks.
331 */
332
333 skb_queue_head(&sk->sk_receive_queue, skb);
334 ret = -EMSGSIZE;
335 goto read_error;
336 }
337
338 ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, len);
339 if (ret)
340 goto read_error;
341
342 skb_free_datagram(sk, skb);
343
344 caif_check_flow_release(sk);
345
346 return len;
347
348 read_error:
349 return ret;
350 }
351
352
353 /* Copied from unix_stream_wait_data, identical except for lock call. */
354 static long caif_stream_data_wait(struct sock *sk, long timeo)
355 {
356 DEFINE_WAIT(wait);
357 lock_sock(sk);
358
359 for (;;) {
360 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
361
362 if (!skb_queue_empty(&sk->sk_receive_queue) ||
363 sk->sk_err ||
364 sk->sk_state != CAIF_CONNECTED ||
365 sock_flag(sk, SOCK_DEAD) ||
366 (sk->sk_shutdown & RCV_SHUTDOWN) ||
367 signal_pending(current) ||
368 !timeo)
369 break;
370
371 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
372 release_sock(sk);
373 timeo = schedule_timeout(timeo);
374 lock_sock(sk);
375 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
376 }
377
378 finish_wait(sk_sleep(sk), &wait);
379 release_sock(sk);
380 return timeo;
381 }
382
383
384 /*
385 * Copied from unix_stream_recvmsg, but removed credit checks,
386 * changed locking calls, changed address handling.
387 */
388 static int caif_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
389 struct msghdr *msg, size_t size,
390 int flags)
391 {
392 struct sock *sk = sock->sk;
393 int copied = 0;
394 int target;
395 int err = 0;
396 long timeo;
397
398 err = -EOPNOTSUPP;
399 if (flags&MSG_OOB)
400 goto out;
401
402 msg->msg_namelen = 0;
403
404 /*
405 * Lock the socket to prevent queue disordering
406 * while sleeps in memcpy_tomsg
407 */
408 err = -EAGAIN;
409 if (sk->sk_state == CAIF_CONNECTING)
410 goto out;
411
412 caif_read_lock(sk);
413 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
414 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
415
416 do {
417 int chunk;
418 struct sk_buff *skb;
419
420 lock_sock(sk);
421 skb = skb_dequeue(&sk->sk_receive_queue);
422 caif_check_flow_release(sk);
423
424 if (skb == NULL) {
425 if (copied >= target)
426 goto unlock;
427 /*
428 * POSIX 1003.1g mandates this order.
429 */
430 err = sock_error(sk);
431 if (err)
432 goto unlock;
433 err = -ECONNRESET;
434 if (sk->sk_shutdown & RCV_SHUTDOWN)
435 goto unlock;
436
437 err = -EPIPE;
438 if (sk->sk_state != CAIF_CONNECTED)
439 goto unlock;
440 if (sock_flag(sk, SOCK_DEAD))
441 goto unlock;
442
443 release_sock(sk);
444
445 err = -EAGAIN;
446 if (!timeo)
447 break;
448
449 caif_read_unlock(sk);
450
451 timeo = caif_stream_data_wait(sk, timeo);
452
453 if (signal_pending(current)) {
454 err = sock_intr_errno(timeo);
455 goto out;
456 }
457 caif_read_lock(sk);
458 continue;
459 unlock:
460 release_sock(sk);
461 break;
462 }
463 release_sock(sk);
464 chunk = min_t(unsigned int, skb->len, size);
465 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
466 skb_queue_head(&sk->sk_receive_queue, skb);
467 if (copied == 0)
468 copied = -EFAULT;
469 break;
470 }
471 copied += chunk;
472 size -= chunk;
473
474 /* Mark read part of skb as used */
475 if (!(flags & MSG_PEEK)) {
476 skb_pull(skb, chunk);
477
478 /* put the skb back if we didn't use it up. */
479 if (skb->len) {
480 skb_queue_head(&sk->sk_receive_queue, skb);
481 break;
482 }
483 kfree_skb(skb);
484
485 } else {
486 /*
487 * It is questionable, see note in unix_dgram_recvmsg.
488 */
489 /* put message back and return */
490 skb_queue_head(&sk->sk_receive_queue, skb);
491 break;
492 }
493 } while (size);
494 caif_read_unlock(sk);
495
496 out:
497 return copied ? : err;
498 }
499
500 /*
501 * Copied from sock.c:sock_wait_for_wmem, but change to wait for
502 * CAIF flow-on and sock_writable.
503 */
504 static long caif_wait_for_flow_on(struct caifsock *cf_sk,
505 int wait_writeable, long timeo, int *err)
506 {
507 struct sock *sk = &cf_sk->sk;
508 DEFINE_WAIT(wait);
509 for (;;) {
510 *err = 0;
511 if (tx_flow_is_on(cf_sk) &&
512 (!wait_writeable || sock_writeable(&cf_sk->sk)))
513 break;
514 *err = -ETIMEDOUT;
515 if (!timeo)
516 break;
517 *err = -ERESTARTSYS;
518 if (signal_pending(current))
519 break;
520 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
521 *err = -ECONNRESET;
522 if (sk->sk_shutdown & SHUTDOWN_MASK)
523 break;
524 *err = -sk->sk_err;
525 if (sk->sk_err)
526 break;
527 *err = -EPIPE;
528 if (cf_sk->sk.sk_state != CAIF_CONNECTED)
529 break;
530 timeo = schedule_timeout(timeo);
531 }
532 finish_wait(sk_sleep(sk), &wait);
533 return timeo;
534 }
535
536 /*
537 * Transmit a SKB. The device may temporarily request re-transmission
538 * by returning EAGAIN.
539 */
540 static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk,
541 int noblock, long timeo)
542 {
543 struct cfpkt *pkt;
544 int ret, loopcnt = 0;
545
546 pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb);
547 memset(cfpkt_info(pkt), 0, sizeof(struct caif_payload_info));
548 do {
549
550 ret = -ETIMEDOUT;
551
552 /* Slight paranoia, probably not needed. */
553 if (unlikely(loopcnt++ > 1000)) {
554 pr_warning("CAIF: %s(): transmit retries failed,"
555 " error = %d\n", __func__, ret);
556 break;
557 }
558
559 if (cf_sk->layer.dn != NULL)
560 ret = cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
561 if (likely(ret >= 0))
562 break;
563 /* if transmit return -EAGAIN, then retry */
564 if (noblock && ret == -EAGAIN)
565 break;
566 timeo = caif_wait_for_flow_on(cf_sk, 0, timeo, &ret);
567 if (signal_pending(current)) {
568 ret = sock_intr_errno(timeo);
569 break;
570 }
571 if (ret)
572 break;
573 if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
574 sock_flag(&cf_sk->sk, SOCK_DEAD) ||
575 (cf_sk->sk.sk_shutdown & RCV_SHUTDOWN)) {
576 ret = -EPIPE;
577 cf_sk->sk.sk_err = EPIPE;
578 break;
579 }
580 } while (ret == -EAGAIN);
581 return ret;
582 }
583
584 /* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
585 static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock,
586 struct msghdr *msg, size_t len)
587 {
588 struct sock *sk = sock->sk;
589 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
590 int buffer_size;
591 int ret = 0;
592 struct sk_buff *skb = NULL;
593 int noblock;
594 long timeo;
595 caif_assert(cf_sk);
596 ret = sock_error(sk);
597 if (ret)
598 goto err;
599
600 ret = -EOPNOTSUPP;
601 if (msg->msg_flags&MSG_OOB)
602 goto err;
603
604 ret = -EOPNOTSUPP;
605 if (msg->msg_namelen)
606 goto err;
607
608 ret = -EINVAL;
609 if (unlikely(msg->msg_iov->iov_base == NULL))
610 goto err;
611 noblock = msg->msg_flags & MSG_DONTWAIT;
612
613 buffer_size = len + CAIF_NEEDED_HEADROOM + CAIF_NEEDED_TAILROOM;
614
615 ret = -EMSGSIZE;
616 if (buffer_size > CAIF_MAX_PAYLOAD_SIZE)
617 goto err;
618
619 timeo = sock_sndtimeo(sk, noblock);
620 timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
621 1, timeo, &ret);
622
623 ret = -EPIPE;
624 if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
625 sock_flag(sk, SOCK_DEAD) ||
626 (sk->sk_shutdown & RCV_SHUTDOWN))
627 goto err;
628
629 ret = -ENOMEM;
630 skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
631 if (!skb)
632 goto err;
633 skb_reserve(skb, CAIF_NEEDED_HEADROOM);
634
635 ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
636
637 if (ret)
638 goto err;
639 ret = transmit_skb(skb, cf_sk, noblock, timeo);
640 if (ret < 0)
641 goto err;
642 return len;
643 err:
644 kfree_skb(skb);
645 return ret;
646 }
647
648 /*
649 * Copied from unix_stream_sendmsg and adapted to CAIF:
650 * Changed removed permission handling and added waiting for flow on
651 * and other minor adaptations.
652 */
653 static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
654 struct msghdr *msg, size_t len)
655 {
656 struct sock *sk = sock->sk;
657 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
658 int err, size;
659 struct sk_buff *skb;
660 int sent = 0;
661 long timeo;
662
663 err = -EOPNOTSUPP;
664
665 if (unlikely(msg->msg_flags&MSG_OOB))
666 goto out_err;
667
668 if (unlikely(msg->msg_namelen))
669 goto out_err;
670
671 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
672 timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
673
674 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
675 goto pipe_err;
676
677 while (sent < len) {
678
679 size = len-sent;
680
681 if (size > CAIF_MAX_PAYLOAD_SIZE)
682 size = CAIF_MAX_PAYLOAD_SIZE;
683
684 /* If size is more than half of sndbuf, chop up message */
685 if (size > ((sk->sk_sndbuf >> 1) - 64))
686 size = (sk->sk_sndbuf >> 1) - 64;
687
688 if (size > SKB_MAX_ALLOC)
689 size = SKB_MAX_ALLOC;
690
691 skb = sock_alloc_send_skb(sk,
692 size + CAIF_NEEDED_HEADROOM
693 + CAIF_NEEDED_TAILROOM,
694 msg->msg_flags&MSG_DONTWAIT,
695 &err);
696 if (skb == NULL)
697 goto out_err;
698
699 skb_reserve(skb, CAIF_NEEDED_HEADROOM);
700 /*
701 * If you pass two values to the sock_alloc_send_skb
702 * it tries to grab the large buffer with GFP_NOFS
703 * (which can fail easily), and if it fails grab the
704 * fallback size buffer which is under a page and will
705 * succeed. [Alan]
706 */
707 size = min_t(int, size, skb_tailroom(skb));
708
709 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
710 if (err) {
711 kfree_skb(skb);
712 goto out_err;
713 }
714 err = transmit_skb(skb, cf_sk,
715 msg->msg_flags&MSG_DONTWAIT, timeo);
716 if (err < 0) {
717 kfree_skb(skb);
718 goto pipe_err;
719 }
720 sent += size;
721 }
722
723 return sent;
724
725 pipe_err:
726 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
727 send_sig(SIGPIPE, current, 0);
728 err = -EPIPE;
729 out_err:
730 return sent ? : err;
731 }
732
733 static int setsockopt(struct socket *sock,
734 int lvl, int opt, char __user *ov, unsigned int ol)
735 {
736 struct sock *sk = sock->sk;
737 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
738 int prio, linksel;
739 struct ifreq ifreq;
740
741 if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
742 return -ENOPROTOOPT;
743
744 switch (opt) {
745 case CAIFSO_LINK_SELECT:
746 if (ol < sizeof(int))
747 return -EINVAL;
748 if (lvl != SOL_CAIF)
749 goto bad_sol;
750 if (copy_from_user(&linksel, ov, sizeof(int)))
751 return -EINVAL;
752 lock_sock(&(cf_sk->sk));
753 cf_sk->conn_req.link_selector = linksel;
754 release_sock(&cf_sk->sk);
755 return 0;
756
757 case SO_PRIORITY:
758 if (lvl != SOL_SOCKET)
759 goto bad_sol;
760 if (ol < sizeof(int))
761 return -EINVAL;
762 if (copy_from_user(&prio, ov, sizeof(int)))
763 return -EINVAL;
764 lock_sock(&(cf_sk->sk));
765 cf_sk->conn_req.priority = prio;
766 release_sock(&cf_sk->sk);
767 return 0;
768
769 case SO_BINDTODEVICE:
770 if (lvl != SOL_SOCKET)
771 goto bad_sol;
772 if (ol < sizeof(struct ifreq))
773 return -EINVAL;
774 if (copy_from_user(&ifreq, ov, sizeof(ifreq)))
775 return -EFAULT;
776 lock_sock(&(cf_sk->sk));
777 strncpy(cf_sk->conn_req.link_name, ifreq.ifr_name,
778 sizeof(cf_sk->conn_req.link_name));
779 cf_sk->conn_req.link_name
780 [sizeof(cf_sk->conn_req.link_name)-1] = 0;
781 release_sock(&cf_sk->sk);
782 return 0;
783
784 case CAIFSO_REQ_PARAM:
785 if (lvl != SOL_CAIF)
786 goto bad_sol;
787 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
788 return -ENOPROTOOPT;
789 lock_sock(&(cf_sk->sk));
790 cf_sk->conn_req.param.size = ol;
791 if (ol > sizeof(cf_sk->conn_req.param.data) ||
792 copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) {
793 release_sock(&cf_sk->sk);
794 return -EINVAL;
795 }
796 release_sock(&cf_sk->sk);
797 return 0;
798
799 default:
800 return -ENOPROTOOPT;
801 }
802
803 return 0;
804 bad_sol:
805 return -ENOPROTOOPT;
806
807 }
808
809 /*
810 * caif_connect() - Connect a CAIF Socket
811 * Copied and modified af_irda.c:irda_connect().
812 *
813 * Note : by consulting "errno", the user space caller may learn the cause
814 * of the failure. Most of them are visible in the function, others may come
815 * from subroutines called and are listed here :
816 * o -EAFNOSUPPORT: bad socket family or type.
817 * o -ESOCKTNOSUPPORT: bad socket type or protocol
818 * o -EINVAL: bad socket address, or CAIF link type
819 * o -ECONNREFUSED: remote end refused the connection.
820 * o -EINPROGRESS: connect request sent but timed out (or non-blocking)
821 * o -EISCONN: already connected.
822 * o -ETIMEDOUT: Connection timed out (send timeout)
823 * o -ENODEV: No link layer to send request
824 * o -ECONNRESET: Received Shutdown indication or lost link layer
825 * o -ENOMEM: Out of memory
826 *
827 * State Strategy:
828 * o sk_state: holds the CAIF_* protocol state, it's updated by
829 * caif_ctrl_cb.
830 * o sock->state: holds the SS_* socket state and is updated by connect and
831 * disconnect.
832 */
833 static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
834 int addr_len, int flags)
835 {
836 struct sock *sk = sock->sk;
837 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
838 long timeo;
839 int err;
840 lock_sock(sk);
841
842 err = -EAFNOSUPPORT;
843 if (uaddr->sa_family != AF_CAIF)
844 goto out;
845
846 err = -ESOCKTNOSUPPORT;
847 if (unlikely(!(sk->sk_type == SOCK_STREAM &&
848 cf_sk->sk.sk_protocol == CAIFPROTO_AT) &&
849 sk->sk_type != SOCK_SEQPACKET))
850 goto out;
851 switch (sock->state) {
852 case SS_UNCONNECTED:
853 /* Normal case, a fresh connect */
854 caif_assert(sk->sk_state == CAIF_DISCONNECTED);
855 break;
856 case SS_CONNECTING:
857 switch (sk->sk_state) {
858 case CAIF_CONNECTED:
859 sock->state = SS_CONNECTED;
860 err = -EISCONN;
861 goto out;
862 case CAIF_DISCONNECTED:
863 /* Reconnect allowed */
864 break;
865 case CAIF_CONNECTING:
866 err = -EALREADY;
867 if (flags & O_NONBLOCK)
868 goto out;
869 goto wait_connect;
870 }
871 break;
872 case SS_CONNECTED:
873 caif_assert(sk->sk_state == CAIF_CONNECTED ||
874 sk->sk_state == CAIF_DISCONNECTED);
875 if (sk->sk_shutdown & SHUTDOWN_MASK) {
876 /* Allow re-connect after SHUTDOWN_IND */
877 caif_disconnect_client(&cf_sk->layer);
878 break;
879 }
880 /* No reconnect on a seqpacket socket */
881 err = -EISCONN;
882 goto out;
883 case SS_DISCONNECTING:
884 case SS_FREE:
885 caif_assert(1); /*Should never happen */
886 break;
887 }
888 sk->sk_state = CAIF_DISCONNECTED;
889 sock->state = SS_UNCONNECTED;
890 sk_stream_kill_queues(&cf_sk->sk);
891
892 err = -EINVAL;
893 if (addr_len != sizeof(struct sockaddr_caif) ||
894 !uaddr)
895 goto out;
896
897 memcpy(&cf_sk->conn_req.sockaddr, uaddr,
898 sizeof(struct sockaddr_caif));
899
900 /* Move to connecting socket, start sending Connect Requests */
901 sock->state = SS_CONNECTING;
902 sk->sk_state = CAIF_CONNECTING;
903
904 dbfs_atomic_inc(&cnt.num_connect_req);
905 cf_sk->layer.receive = caif_sktrecv_cb;
906 err = caif_connect_client(&cf_sk->conn_req,
907 &cf_sk->layer);
908 if (err < 0) {
909 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
910 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
911 goto out;
912 }
913
914 err = -EINPROGRESS;
915 wait_connect:
916
917 if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
918 goto out;
919
920 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
921
922 release_sock(sk);
923 err = wait_event_interruptible_timeout(*sk_sleep(sk),
924 sk->sk_state != CAIF_CONNECTING,
925 timeo);
926 lock_sock(sk);
927 if (err < 0)
928 goto out; /* -ERESTARTSYS */
929 if (err == 0 && sk->sk_state != CAIF_CONNECTED) {
930 err = -ETIMEDOUT;
931 goto out;
932 }
933
934 if (sk->sk_state != CAIF_CONNECTED) {
935 sock->state = SS_UNCONNECTED;
936 err = sock_error(sk);
937 if (!err)
938 err = -ECONNREFUSED;
939 goto out;
940 }
941 sock->state = SS_CONNECTED;
942 err = 0;
943 out:
944 release_sock(sk);
945 return err;
946 }
947
948
949 /*
950 * caif_release() - Disconnect a CAIF Socket
951 * Copied and modified af_irda.c:irda_release().
952 */
953 static int caif_release(struct socket *sock)
954 {
955 struct sock *sk = sock->sk;
956 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
957 int res = 0;
958
959 if (!sk)
960 return 0;
961
962 set_tx_flow_off(cf_sk);
963
964 /*
965 * Ensure that packets are not queued after this point in time.
966 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
967 * this ensures no packets when sock is dead.
968 */
969 spin_lock(&sk->sk_receive_queue.lock);
970 sock_set_flag(sk, SOCK_DEAD);
971 spin_unlock(&sk->sk_receive_queue.lock);
972 sock->sk = NULL;
973
974 dbfs_atomic_inc(&cnt.num_disconnect);
975
976 if (cf_sk->debugfs_socket_dir != NULL)
977 debugfs_remove_recursive(cf_sk->debugfs_socket_dir);
978
979 lock_sock(&(cf_sk->sk));
980 sk->sk_state = CAIF_DISCONNECTED;
981 sk->sk_shutdown = SHUTDOWN_MASK;
982
983 if (cf_sk->sk.sk_socket->state == SS_CONNECTED ||
984 cf_sk->sk.sk_socket->state == SS_CONNECTING)
985 res = caif_disconnect_client(&cf_sk->layer);
986
987 cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
988 wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP);
989
990 sock_orphan(sk);
991 cf_sk->layer.dn = NULL;
992 sk_stream_kill_queues(&cf_sk->sk);
993 release_sock(sk);
994 sock_put(sk);
995 return res;
996 }
997
998 /* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */
999 static unsigned int caif_poll(struct file *file,
1000 struct socket *sock, poll_table *wait)
1001 {
1002 struct sock *sk = sock->sk;
1003 unsigned int mask;
1004 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1005
1006 sock_poll_wait(file, sk_sleep(sk), wait);
1007 mask = 0;
1008
1009 /* exceptional events? */
1010 if (sk->sk_err)
1011 mask |= POLLERR;
1012 if (sk->sk_shutdown == SHUTDOWN_MASK)
1013 mask |= POLLHUP;
1014 if (sk->sk_shutdown & RCV_SHUTDOWN)
1015 mask |= POLLRDHUP;
1016
1017 /* readable? */
1018 if (!skb_queue_empty(&sk->sk_receive_queue) ||
1019 (sk->sk_shutdown & RCV_SHUTDOWN))
1020 mask |= POLLIN | POLLRDNORM;
1021
1022 /* Connection-based need to check for termination and startup */
1023 if (sk->sk_state == CAIF_DISCONNECTED)
1024 mask |= POLLHUP;
1025
1026 /*
1027 * we set writable also when the other side has shut down the
1028 * connection. This prevents stuck sockets.
1029 */
1030 if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
1031 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1032
1033 return mask;
1034 }
1035
1036 static const struct proto_ops caif_seqpacket_ops = {
1037 .family = PF_CAIF,
1038 .owner = THIS_MODULE,
1039 .release = caif_release,
1040 .bind = sock_no_bind,
1041 .connect = caif_connect,
1042 .socketpair = sock_no_socketpair,
1043 .accept = sock_no_accept,
1044 .getname = sock_no_getname,
1045 .poll = caif_poll,
1046 .ioctl = sock_no_ioctl,
1047 .listen = sock_no_listen,
1048 .shutdown = sock_no_shutdown,
1049 .setsockopt = setsockopt,
1050 .getsockopt = sock_no_getsockopt,
1051 .sendmsg = caif_seqpkt_sendmsg,
1052 .recvmsg = caif_seqpkt_recvmsg,
1053 .mmap = sock_no_mmap,
1054 .sendpage = sock_no_sendpage,
1055 };
1056
1057 static const struct proto_ops caif_stream_ops = {
1058 .family = PF_CAIF,
1059 .owner = THIS_MODULE,
1060 .release = caif_release,
1061 .bind = sock_no_bind,
1062 .connect = caif_connect,
1063 .socketpair = sock_no_socketpair,
1064 .accept = sock_no_accept,
1065 .getname = sock_no_getname,
1066 .poll = caif_poll,
1067 .ioctl = sock_no_ioctl,
1068 .listen = sock_no_listen,
1069 .shutdown = sock_no_shutdown,
1070 .setsockopt = setsockopt,
1071 .getsockopt = sock_no_getsockopt,
1072 .sendmsg = caif_stream_sendmsg,
1073 .recvmsg = caif_stream_recvmsg,
1074 .mmap = sock_no_mmap,
1075 .sendpage = sock_no_sendpage,
1076 };
1077
1078 /* This function is called when a socket is finally destroyed. */
1079 static void caif_sock_destructor(struct sock *sk)
1080 {
1081 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1082 caif_assert(!atomic_read(&sk->sk_wmem_alloc));
1083 caif_assert(sk_unhashed(sk));
1084 caif_assert(!sk->sk_socket);
1085 if (!sock_flag(sk, SOCK_DEAD)) {
1086 pr_info("Attempt to release alive CAIF socket: %p\n", sk);
1087 return;
1088 }
1089 sk_stream_kill_queues(&cf_sk->sk);
1090 dbfs_atomic_dec(&cnt.caif_nr_socks);
1091 }
1092
1093 static int caif_create(struct net *net, struct socket *sock, int protocol,
1094 int kern)
1095 {
1096 struct sock *sk = NULL;
1097 struct caifsock *cf_sk = NULL;
1098 static struct proto prot = {.name = "PF_CAIF",
1099 .owner = THIS_MODULE,
1100 .obj_size = sizeof(struct caifsock),
1101 };
1102
1103 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
1104 return -EPERM;
1105 /*
1106 * The sock->type specifies the socket type to use.
1107 * The CAIF socket is a packet stream in the sense
1108 * that it is packet based. CAIF trusts the reliability
1109 * of the link, no resending is implemented.
1110 */
1111 if (sock->type == SOCK_SEQPACKET)
1112 sock->ops = &caif_seqpacket_ops;
1113 else if (sock->type == SOCK_STREAM)
1114 sock->ops = &caif_stream_ops;
1115 else
1116 return -ESOCKTNOSUPPORT;
1117
1118 if (protocol < 0 || protocol >= CAIFPROTO_MAX)
1119 return -EPROTONOSUPPORT;
1120 /*
1121 * Set the socket state to unconnected. The socket state
1122 * is really not used at all in the net/core or socket.c but the
1123 * initialization makes sure that sock->state is not uninitialized.
1124 */
1125 sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot);
1126 if (!sk)
1127 return -ENOMEM;
1128
1129 cf_sk = container_of(sk, struct caifsock, sk);
1130
1131 /* Store the protocol */
1132 sk->sk_protocol = (unsigned char) protocol;
1133
1134 /* Sendbuf dictates the amount of outbound packets not yet sent */
1135 sk->sk_sndbuf = CAIF_DEF_SNDBUF;
1136 sk->sk_rcvbuf = CAIF_DEF_RCVBUF;
1137
1138 /*
1139 * Lock in order to try to stop someone from opening the socket
1140 * too early.
1141 */
1142 lock_sock(&(cf_sk->sk));
1143
1144 /* Initialize the nozero default sock structure data. */
1145 sock_init_data(sock, sk);
1146 sk->sk_destruct = caif_sock_destructor;
1147
1148 mutex_init(&cf_sk->readlock); /* single task reading lock */
1149 cf_sk->layer.ctrlcmd = caif_ctrl_cb;
1150 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
1151 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
1152
1153 set_tx_flow_off(cf_sk);
1154 set_rx_flow_on(cf_sk);
1155
1156 /* Set default options on configuration */
1157 cf_sk->conn_req.priority = CAIF_PRIO_NORMAL;
1158 cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1159 cf_sk->conn_req.protocol = protocol;
1160 /* Increase the number of sockets created. */
1161 dbfs_atomic_inc(&cnt.caif_nr_socks);
1162 #ifdef CONFIG_DEBUG_FS
1163 if (!IS_ERR(debugfsdir)) {
1164 /* Fill in some information concerning the misc socket. */
1165 snprintf(cf_sk->name, sizeof(cf_sk->name), "cfsk%d",
1166 atomic_read(&cnt.caif_nr_socks));
1167
1168 cf_sk->debugfs_socket_dir =
1169 debugfs_create_dir(cf_sk->name, debugfsdir);
1170 debugfs_create_u32("sk_state", S_IRUSR | S_IWUSR,
1171 cf_sk->debugfs_socket_dir,
1172 (u32 *) &cf_sk->sk.sk_state);
1173 debugfs_create_u32("flow_state", S_IRUSR | S_IWUSR,
1174 cf_sk->debugfs_socket_dir, &cf_sk->flow_state);
1175 debugfs_create_u32("sk_rmem_alloc", S_IRUSR | S_IWUSR,
1176 cf_sk->debugfs_socket_dir,
1177 (u32 *) &cf_sk->sk.sk_rmem_alloc);
1178 debugfs_create_u32("sk_wmem_alloc", S_IRUSR | S_IWUSR,
1179 cf_sk->debugfs_socket_dir,
1180 (u32 *) &cf_sk->sk.sk_wmem_alloc);
1181 debugfs_create_u32("identity", S_IRUSR | S_IWUSR,
1182 cf_sk->debugfs_socket_dir,
1183 (u32 *) &cf_sk->layer.id);
1184 }
1185 #endif
1186 release_sock(&cf_sk->sk);
1187 return 0;
1188 }
1189
1190
1191 static struct net_proto_family caif_family_ops = {
1192 .family = PF_CAIF,
1193 .create = caif_create,
1194 .owner = THIS_MODULE,
1195 };
1196
1197 int af_caif_init(void)
1198 {
1199 int err = sock_register(&caif_family_ops);
1200 if (!err)
1201 return err;
1202 return 0;
1203 }
1204
1205 static int __init caif_sktinit_module(void)
1206 {
1207 #ifdef CONFIG_DEBUG_FS
1208 debugfsdir = debugfs_create_dir("caif_sk", NULL);
1209 if (!IS_ERR(debugfsdir)) {
1210 debugfs_create_u32("num_sockets", S_IRUSR | S_IWUSR,
1211 debugfsdir,
1212 (u32 *) &cnt.caif_nr_socks);
1213 debugfs_create_u32("num_connect_req", S_IRUSR | S_IWUSR,
1214 debugfsdir,
1215 (u32 *) &cnt.num_connect_req);
1216 debugfs_create_u32("num_connect_resp", S_IRUSR | S_IWUSR,
1217 debugfsdir,
1218 (u32 *) &cnt.num_connect_resp);
1219 debugfs_create_u32("num_connect_fail_resp", S_IRUSR | S_IWUSR,
1220 debugfsdir,
1221 (u32 *) &cnt.num_connect_fail_resp);
1222 debugfs_create_u32("num_disconnect", S_IRUSR | S_IWUSR,
1223 debugfsdir,
1224 (u32 *) &cnt.num_disconnect);
1225 debugfs_create_u32("num_remote_shutdown_ind",
1226 S_IRUSR | S_IWUSR, debugfsdir,
1227 (u32 *) &cnt.num_remote_shutdown_ind);
1228 debugfs_create_u32("num_tx_flow_off_ind", S_IRUSR | S_IWUSR,
1229 debugfsdir,
1230 (u32 *) &cnt.num_tx_flow_off_ind);
1231 debugfs_create_u32("num_tx_flow_on_ind", S_IRUSR | S_IWUSR,
1232 debugfsdir,
1233 (u32 *) &cnt.num_tx_flow_on_ind);
1234 debugfs_create_u32("num_rx_flow_off", S_IRUSR | S_IWUSR,
1235 debugfsdir,
1236 (u32 *) &cnt.num_rx_flow_off);
1237 debugfs_create_u32("num_rx_flow_on", S_IRUSR | S_IWUSR,
1238 debugfsdir,
1239 (u32 *) &cnt.num_rx_flow_on);
1240 }
1241 #endif
1242 return af_caif_init();
1243 }
1244
1245 static void __exit caif_sktexit_module(void)
1246 {
1247 sock_unregister(PF_CAIF);
1248 if (debugfsdir != NULL)
1249 debugfs_remove_recursive(debugfsdir);
1250 }
1251 module_init(caif_sktinit_module);
1252 module_exit(caif_sktexit_module);
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