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caif: Bugfix - missing spin_unlock
[linux-2.6.git] / net / caif / caif_socket.c
blob691a5710974e660f12b28d136bb67ff6954eadb5
1 /*
2 * Copyright (C) ST-Ericsson AB 2010
3 * Author: Sjur Brendeland sjur.brandeland@stericsson.com
4 * License terms: GNU General Public License (GPL) version 2
5 */
6
7 #include <linux/fs.h>
8 #include <linux/init.h>
9 #include <linux/module.h>
10 #include <linux/sched.h>
11 #include <linux/spinlock.h>
12 #include <linux/mutex.h>
13 #include <linux/list.h>
14 #include <linux/wait.h>
15 #include <linux/poll.h>
16 #include <linux/tcp.h>
17 #include <linux/uaccess.h>
18 #include <linux/mutex.h>
19 #include <linux/debugfs.h>
20 #include <linux/caif/caif_socket.h>
21 #include <asm/atomic.h>
22 #include <net/sock.h>
23 #include <net/tcp_states.h>
24 #include <net/caif/caif_layer.h>
25 #include <net/caif/caif_dev.h>
26 #include <net/caif/cfpkt.h>
27
28 MODULE_LICENSE("GPL");
29 MODULE_ALIAS_NETPROTO(AF_CAIF);
30
31 #define CAIF_DEF_SNDBUF (CAIF_MAX_PAYLOAD_SIZE*10)
32 #define CAIF_DEF_RCVBUF (CAIF_MAX_PAYLOAD_SIZE*100)
33
34 /*
35 * CAIF state is re-using the TCP socket states.
36 * caif_states stored in sk_state reflect the state as reported by
37 * the CAIF stack, while sk_socket->state is the state of the socket.
38 */
39 enum caif_states {
40 CAIF_CONNECTED = TCP_ESTABLISHED,
41 CAIF_CONNECTING = TCP_SYN_SENT,
42 CAIF_DISCONNECTED = TCP_CLOSE
43 };
44
45 #define TX_FLOW_ON_BIT 1
46 #define RX_FLOW_ON_BIT 2
47
48 static struct dentry *debugfsdir;
49
50 #ifdef CONFIG_DEBUG_FS
51 struct debug_fs_counter {
52 atomic_t caif_nr_socks;
53 atomic_t num_connect_req;
54 atomic_t num_connect_resp;
55 atomic_t num_connect_fail_resp;
56 atomic_t num_disconnect;
57 atomic_t num_remote_shutdown_ind;
58 atomic_t num_tx_flow_off_ind;
59 atomic_t num_tx_flow_on_ind;
60 atomic_t num_rx_flow_off;
61 atomic_t num_rx_flow_on;
62 };
63 static struct debug_fs_counter cnt;
64 #define dbfs_atomic_inc(v) atomic_inc(v)
65 #define dbfs_atomic_dec(v) atomic_dec(v)
66 #else
67 #define dbfs_atomic_inc(v)
68 #define dbfs_atomic_dec(v)
69 #endif
70
71 struct caifsock {
72 struct sock sk; /* must be first member */
73 struct cflayer layer;
74 char name[CAIF_LAYER_NAME_SZ]; /* Used for debugging */
75 u32 flow_state;
76 struct caif_connect_request conn_req;
77 struct mutex readlock;
78 struct dentry *debugfs_socket_dir;
79 };
80
81 static int rx_flow_is_on(struct caifsock *cf_sk)
82 {
83 return test_bit(RX_FLOW_ON_BIT,
84 (void *) &cf_sk->flow_state);
85 }
86
87 static int tx_flow_is_on(struct caifsock *cf_sk)
88 {
89 return test_bit(TX_FLOW_ON_BIT,
90 (void *) &cf_sk->flow_state);
91 }
92
93 static void set_rx_flow_off(struct caifsock *cf_sk)
94 {
95 clear_bit(RX_FLOW_ON_BIT,
96 (void *) &cf_sk->flow_state);
97 }
98
99 static void set_rx_flow_on(struct caifsock *cf_sk)
100 {
101 set_bit(RX_FLOW_ON_BIT,
102 (void *) &cf_sk->flow_state);
103 }
104
105 static void set_tx_flow_off(struct caifsock *cf_sk)
106 {
107 clear_bit(TX_FLOW_ON_BIT,
108 (void *) &cf_sk->flow_state);
109 }
110
111 static void set_tx_flow_on(struct caifsock *cf_sk)
112 {
113 set_bit(TX_FLOW_ON_BIT,
114 (void *) &cf_sk->flow_state);
115 }
116
117 static void caif_read_lock(struct sock *sk)
118 {
119 struct caifsock *cf_sk;
120 cf_sk = container_of(sk, struct caifsock, sk);
121 mutex_lock(&cf_sk->readlock);
122 }
123
124 static void caif_read_unlock(struct sock *sk)
125 {
126 struct caifsock *cf_sk;
127 cf_sk = container_of(sk, struct caifsock, sk);
128 mutex_unlock(&cf_sk->readlock);
129 }
130
131 static int sk_rcvbuf_lowwater(struct caifsock *cf_sk)
132 {
133 /* A quarter of full buffer is used a low water mark */
134 return cf_sk->sk.sk_rcvbuf / 4;
135 }
136
137 static void caif_flow_ctrl(struct sock *sk, int mode)
138 {
139 struct caifsock *cf_sk;
140 cf_sk = container_of(sk, struct caifsock, sk);
141 if (cf_sk->layer.dn && cf_sk->layer.dn->modemcmd)
142 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, mode);
143 }
144
145 /*
146 * Copied from sock.c:sock_queue_rcv_skb(), but changed so packets are
147 * not dropped, but CAIF is sending flow off instead.
148 */
149 static int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
150 {
151 int err;
152 int skb_len;
153 unsigned long flags;
154 struct sk_buff_head *list = &sk->sk_receive_queue;
155 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
156
157 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
158 (unsigned)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) {
159 trace_printk("CAIF: %s():"
160 " sending flow OFF (queue len = %d %d)\n",
161 __func__,
162 atomic_read(&cf_sk->sk.sk_rmem_alloc),
163 sk_rcvbuf_lowwater(cf_sk));
164 set_rx_flow_off(cf_sk);
165 dbfs_atomic_inc(&cnt.num_rx_flow_off);
166 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
167 }
168
169 err = sk_filter(sk, skb);
170 if (err)
171 return err;
172 if (!sk_rmem_schedule(sk, skb->truesize) && rx_flow_is_on(cf_sk)) {
173 set_rx_flow_off(cf_sk);
174 trace_printk("CAIF: %s():"
175 " sending flow OFF due to rmem_schedule\n",
176 __func__);
177 dbfs_atomic_inc(&cnt.num_rx_flow_off);
178 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
179 }
180 skb->dev = NULL;
181 skb_set_owner_r(skb, sk);
182 /* Cache the SKB length before we tack it onto the receive
183 * queue. Once it is added it no longer belongs to us and
184 * may be freed by other threads of control pulling packets
185 * from the queue.
186 */
187 skb_len = skb->len;
188 spin_lock_irqsave(&list->lock, flags);
189 if (!sock_flag(sk, SOCK_DEAD))
190 __skb_queue_tail(list, skb);
191 spin_unlock_irqrestore(&list->lock, flags);
192
193 if (!sock_flag(sk, SOCK_DEAD))
194 sk->sk_data_ready(sk, skb_len);
195 else
196 kfree_skb(skb);
197 return 0;
198 }
199
200 /* Packet Receive Callback function called from CAIF Stack */
201 static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
202 {
203 struct caifsock *cf_sk;
204 struct sk_buff *skb;
205
206 cf_sk = container_of(layr, struct caifsock, layer);
207 skb = cfpkt_tonative(pkt);
208
209 if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) {
210 cfpkt_destroy(pkt);
211 return 0;
212 }
213 caif_queue_rcv_skb(&cf_sk->sk, skb);
214 return 0;
215 }
216
217 /* Packet Control Callback function called from CAIF */
218 static void caif_ctrl_cb(struct cflayer *layr,
219 enum caif_ctrlcmd flow,
220 int phyid)
221 {
222 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
223 switch (flow) {
224 case CAIF_CTRLCMD_FLOW_ON_IND:
225 /* OK from modem to start sending again */
226 dbfs_atomic_inc(&cnt.num_tx_flow_on_ind);
227 set_tx_flow_on(cf_sk);
228 cf_sk->sk.sk_state_change(&cf_sk->sk);
229 break;
230
231 case CAIF_CTRLCMD_FLOW_OFF_IND:
232 /* Modem asks us to shut up */
233 dbfs_atomic_inc(&cnt.num_tx_flow_off_ind);
234 set_tx_flow_off(cf_sk);
235 cf_sk->sk.sk_state_change(&cf_sk->sk);
236 break;
237
238 case CAIF_CTRLCMD_INIT_RSP:
239 /* We're now connected */
240 dbfs_atomic_inc(&cnt.num_connect_resp);
241 cf_sk->sk.sk_state = CAIF_CONNECTED;
242 set_tx_flow_on(cf_sk);
243 cf_sk->sk.sk_state_change(&cf_sk->sk);
244 break;
245
246 case CAIF_CTRLCMD_DEINIT_RSP:
247 /* We're now disconnected */
248 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
249 cf_sk->sk.sk_state_change(&cf_sk->sk);
250 cfcnfg_release_adap_layer(&cf_sk->layer);
251 break;
252
253 case CAIF_CTRLCMD_INIT_FAIL_RSP:
254 /* Connect request failed */
255 dbfs_atomic_inc(&cnt.num_connect_fail_resp);
256 cf_sk->sk.sk_err = ECONNREFUSED;
257 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
258 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
259 /*
260 * Socket "standards" seems to require POLLOUT to
261 * be set at connect failure.
262 */
263 set_tx_flow_on(cf_sk);
264 cf_sk->sk.sk_state_change(&cf_sk->sk);
265 break;
266
267 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
268 /* Modem has closed this connection, or device is down. */
269 dbfs_atomic_inc(&cnt.num_remote_shutdown_ind);
270 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
271 cf_sk->sk.sk_err = ECONNRESET;
272 set_rx_flow_on(cf_sk);
273 cf_sk->sk.sk_error_report(&cf_sk->sk);
274 break;
275
276 default:
277 pr_debug("CAIF: %s(): Unexpected flow command %d\n",
278 __func__, flow);
279 }
280 }
281
282 static void caif_check_flow_release(struct sock *sk)
283 {
284 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
285
286 if (rx_flow_is_on(cf_sk))
287 return;
288
289 if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) {
290 dbfs_atomic_inc(&cnt.num_rx_flow_on);
291 set_rx_flow_on(cf_sk);
292 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ);
293 }
294 }
295 /*
296 * Copied from sock.c:sock_queue_rcv_skb(), and added check that user buffer
297 * has sufficient size.
298 */
299
300 static int caif_seqpkt_recvmsg(struct kiocb *iocb, struct socket *sock,
301 struct msghdr *m, size_t buf_len, int flags)
302
303 {
304 struct sock *sk = sock->sk;
305 struct sk_buff *skb;
306 int ret = 0;
307 int len;
308
309 if (unlikely(!buf_len))
310 return -EINVAL;
311
312 skb = skb_recv_datagram(sk, flags, 0 , &ret);
313 if (!skb)
314 goto read_error;
315
316 len = skb->len;
317
318 if (skb && skb->len > buf_len && !(flags & MSG_PEEK)) {
319 len = buf_len;
320 /*
321 * Push skb back on receive queue if buffer too small.
322 * This has a built-in race where multi-threaded receive
323 * may get packet in wrong order, but multiple read does
324 * not really guarantee ordered delivery anyway.
325 * Let's optimize for speed without taking locks.
326 */
327
328 skb_queue_head(&sk->sk_receive_queue, skb);
329 ret = -EMSGSIZE;
330 goto read_error;
331 }
332
333 ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, len);
334 if (ret)
335 goto read_error;
336
337 skb_free_datagram(sk, skb);
338
339 caif_check_flow_release(sk);
340
341 return len;
342
343 read_error:
344 return ret;
345 }
346
347
348 /* Copied from unix_stream_wait_data, identical except for lock call. */
349 static long caif_stream_data_wait(struct sock *sk, long timeo)
350 {
351 DEFINE_WAIT(wait);
352 lock_sock(sk);
353
354 for (;;) {
355 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
356
357 if (!skb_queue_empty(&sk->sk_receive_queue) ||
358 sk->sk_err ||
359 sk->sk_state != CAIF_CONNECTED ||
360 sock_flag(sk, SOCK_DEAD) ||
361 (sk->sk_shutdown & RCV_SHUTDOWN) ||
362 signal_pending(current) ||
363 !timeo)
364 break;
365
366 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
367 release_sock(sk);
368 timeo = schedule_timeout(timeo);
369 lock_sock(sk);
370 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
371 }
372
373 finish_wait(sk_sleep(sk), &wait);
374 release_sock(sk);
375 return timeo;
376 }
377
378
379 /*
380 * Copied from unix_stream_recvmsg, but removed credit checks,
381 * changed locking calls, changed address handling.
382 */
383 static int caif_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
384 struct msghdr *msg, size_t size,
385 int flags)
386 {
387 struct sock *sk = sock->sk;
388 int copied = 0;
389 int target;
390 int err = 0;
391 long timeo;
392
393 err = -EOPNOTSUPP;
394 if (flags&MSG_OOB)
395 goto out;
396
397 msg->msg_namelen = 0;
398
399 /*
400 * Lock the socket to prevent queue disordering
401 * while sleeps in memcpy_tomsg
402 */
403 err = -EAGAIN;
404 if (sk->sk_state == CAIF_CONNECTING)
405 goto out;
406
407 caif_read_lock(sk);
408 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
409 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
410
411 do {
412 int chunk;
413 struct sk_buff *skb;
414
415 lock_sock(sk);
416 skb = skb_dequeue(&sk->sk_receive_queue);
417 caif_check_flow_release(sk);
418
419 if (skb == NULL) {
420 if (copied >= target)
421 goto unlock;
422 /*
423 * POSIX 1003.1g mandates this order.
424 */
425 err = sock_error(sk);
426 if (err)
427 goto unlock;
428 err = -ECONNRESET;
429 if (sk->sk_shutdown & RCV_SHUTDOWN)
430 goto unlock;
431
432 err = -EPIPE;
433 if (sk->sk_state != CAIF_CONNECTED)
434 goto unlock;
435 if (sock_flag(sk, SOCK_DEAD))
436 goto unlock;
437
438 release_sock(sk);
439
440 err = -EAGAIN;
441 if (!timeo)
442 break;
443
444 caif_read_unlock(sk);
445
446 timeo = caif_stream_data_wait(sk, timeo);
447
448 if (signal_pending(current)) {
449 err = sock_intr_errno(timeo);
450 goto out;
451 }
452 caif_read_lock(sk);
453 continue;
454 unlock:
455 release_sock(sk);
456 break;
457 }
458 release_sock(sk);
459 chunk = min_t(unsigned int, skb->len, size);
460 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
461 skb_queue_head(&sk->sk_receive_queue, skb);
462 if (copied == 0)
463 copied = -EFAULT;
464 break;
465 }
466 copied += chunk;
467 size -= chunk;
468
469 /* Mark read part of skb as used */
470 if (!(flags & MSG_PEEK)) {
471 skb_pull(skb, chunk);
472
473 /* put the skb back if we didn't use it up. */
474 if (skb->len) {
475 skb_queue_head(&sk->sk_receive_queue, skb);
476 break;
477 }
478 kfree_skb(skb);
479
480 } else {
481 /*
482 * It is questionable, see note in unix_dgram_recvmsg.
483 */
484 /* put message back and return */
485 skb_queue_head(&sk->sk_receive_queue, skb);
486 break;
487 }
488 } while (size);
489 caif_read_unlock(sk);
490
491 out:
492 return copied ? : err;
493 }
494
495 /*
496 * Copied from sock.c:sock_wait_for_wmem, but change to wait for
497 * CAIF flow-on and sock_writable.
498 */
499 static long caif_wait_for_flow_on(struct caifsock *cf_sk,
500 int wait_writeable, long timeo, int *err)
501 {
502 struct sock *sk = &cf_sk->sk;
503 DEFINE_WAIT(wait);
504 for (;;) {
505 *err = 0;
506 if (tx_flow_is_on(cf_sk) &&
507 (!wait_writeable || sock_writeable(&cf_sk->sk)))
508 break;
509 *err = -ETIMEDOUT;
510 if (!timeo)
511 break;
512 *err = -ERESTARTSYS;
513 if (signal_pending(current))
514 break;
515 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
516 *err = -ECONNRESET;
517 if (sk->sk_shutdown & SHUTDOWN_MASK)
518 break;
519 *err = -sk->sk_err;
520 if (sk->sk_err)
521 break;
522 *err = -EPIPE;
523 if (cf_sk->sk.sk_state != CAIF_CONNECTED)
524 break;
525 timeo = schedule_timeout(timeo);
526 }
527 finish_wait(sk_sleep(sk), &wait);
528 return timeo;
529 }
530
531 /*
532 * Transmit a SKB. The device may temporarily request re-transmission
533 * by returning EAGAIN.
534 */
535 static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk,
536 int noblock, long timeo)
537 {
538 struct cfpkt *pkt;
539 int ret, loopcnt = 0;
540
541 pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb);
542 memset(cfpkt_info(pkt), 0, sizeof(struct caif_payload_info));
543 do {
544
545 ret = -ETIMEDOUT;
546
547 /* Slight paranoia, probably not needed. */
548 if (unlikely(loopcnt++ > 1000)) {
549 pr_warning("CAIF: %s(): transmit retries failed,"
550 " error = %d\n", __func__, ret);
551 break;
552 }
553
554 if (cf_sk->layer.dn != NULL)
555 ret = cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
556 if (likely(ret >= 0))
557 break;
558 /* if transmit return -EAGAIN, then retry */
559 if (noblock && ret == -EAGAIN)
560 break;
561 timeo = caif_wait_for_flow_on(cf_sk, 0, timeo, &ret);
562 if (signal_pending(current)) {
563 ret = sock_intr_errno(timeo);
564 break;
565 }
566 if (ret)
567 break;
568 if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
569 sock_flag(&cf_sk->sk, SOCK_DEAD) ||
570 (cf_sk->sk.sk_shutdown & RCV_SHUTDOWN)) {
571 ret = -EPIPE;
572 cf_sk->sk.sk_err = EPIPE;
573 break;
574 }
575 } while (ret == -EAGAIN);
576 return ret;
577 }
578
579 /* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
580 static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock,
581 struct msghdr *msg, size_t len)
582 {
583 struct sock *sk = sock->sk;
584 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
585 int buffer_size;
586 int ret = 0;
587 struct sk_buff *skb = NULL;
588 int noblock;
589 long timeo;
590 caif_assert(cf_sk);
591 ret = sock_error(sk);
592 if (ret)
593 goto err;
594
595 ret = -EOPNOTSUPP;
596 if (msg->msg_flags&MSG_OOB)
597 goto err;
598
599 ret = -EOPNOTSUPP;
600 if (msg->msg_namelen)
601 goto err;
602
603 ret = -EINVAL;
604 if (unlikely(msg->msg_iov->iov_base == NULL))
605 goto err;
606 noblock = msg->msg_flags & MSG_DONTWAIT;
607
608 buffer_size = len + CAIF_NEEDED_HEADROOM + CAIF_NEEDED_TAILROOM;
609
610 ret = -EMSGSIZE;
611 if (buffer_size > CAIF_MAX_PAYLOAD_SIZE)
612 goto err;
613
614 timeo = sock_sndtimeo(sk, noblock);
615 timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
616 1, timeo, &ret);
617
618 ret = -EPIPE;
619 if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
620 sock_flag(sk, SOCK_DEAD) ||
621 (sk->sk_shutdown & RCV_SHUTDOWN))
622 goto err;
623
624 ret = -ENOMEM;
625 skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
626 if (!skb)
627 goto err;
628 skb_reserve(skb, CAIF_NEEDED_HEADROOM);
629
630 ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
631
632 if (ret)
633 goto err;
634 ret = transmit_skb(skb, cf_sk, noblock, timeo);
635 if (ret < 0)
636 goto err;
637 return len;
638 err:
639 kfree_skb(skb);
640 return ret;
641 }
642
643 /*
644 * Copied from unix_stream_sendmsg and adapted to CAIF:
645 * Changed removed permission handling and added waiting for flow on
646 * and other minor adaptations.
647 */
648 static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
649 struct msghdr *msg, size_t len)
650 {
651 struct sock *sk = sock->sk;
652 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
653 int err, size;
654 struct sk_buff *skb;
655 int sent = 0;
656 long timeo;
657
658 err = -EOPNOTSUPP;
659
660 if (unlikely(msg->msg_flags&MSG_OOB))
661 goto out_err;
662
663 if (unlikely(msg->msg_namelen))
664 goto out_err;
665
666 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
667 timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
668
669 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
670 goto pipe_err;
671
672 while (sent < len) {
673
674 size = len-sent;
675
676 if (size > CAIF_MAX_PAYLOAD_SIZE)
677 size = CAIF_MAX_PAYLOAD_SIZE;
678
679 /* If size is more than half of sndbuf, chop up message */
680 if (size > ((sk->sk_sndbuf >> 1) - 64))
681 size = (sk->sk_sndbuf >> 1) - 64;
682
683 if (size > SKB_MAX_ALLOC)
684 size = SKB_MAX_ALLOC;
685
686 skb = sock_alloc_send_skb(sk,
687 size + CAIF_NEEDED_HEADROOM
688 + CAIF_NEEDED_TAILROOM,
689 msg->msg_flags&MSG_DONTWAIT,
690 &err);
691 if (skb == NULL)
692 goto out_err;
693
694 skb_reserve(skb, CAIF_NEEDED_HEADROOM);
695 /*
696 * If you pass two values to the sock_alloc_send_skb
697 * it tries to grab the large buffer with GFP_NOFS
698 * (which can fail easily), and if it fails grab the
699 * fallback size buffer which is under a page and will
700 * succeed. [Alan]
701 */
702 size = min_t(int, size, skb_tailroom(skb));
703
704 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
705 if (err) {
706 kfree_skb(skb);
707 goto out_err;
708 }
709 err = transmit_skb(skb, cf_sk,
710 msg->msg_flags&MSG_DONTWAIT, timeo);
711 if (err < 0) {
712 kfree_skb(skb);
713 goto pipe_err;
714 }
715 sent += size;
716 }
717
718 return sent;
719
720 pipe_err:
721 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
722 send_sig(SIGPIPE, current, 0);
723 err = -EPIPE;
724 out_err:
725 return sent ? : err;
726 }
727
728 static int setsockopt(struct socket *sock,
729 int lvl, int opt, char __user *ov, unsigned int ol)
730 {
731 struct sock *sk = sock->sk;
732 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
733 int prio, linksel;
734 struct ifreq ifreq;
735
736 if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
737 return -ENOPROTOOPT;
738
739 switch (opt) {
740 case CAIFSO_LINK_SELECT:
741 if (ol < sizeof(int))
742 return -EINVAL;
743 if (lvl != SOL_CAIF)
744 goto bad_sol;
745 if (copy_from_user(&linksel, ov, sizeof(int)))
746 return -EINVAL;
747 lock_sock(&(cf_sk->sk));
748 cf_sk->conn_req.link_selector = linksel;
749 release_sock(&cf_sk->sk);
750 return 0;
751
752 case SO_PRIORITY:
753 if (lvl != SOL_SOCKET)
754 goto bad_sol;
755 if (ol < sizeof(int))
756 return -EINVAL;
757 if (copy_from_user(&prio, ov, sizeof(int)))
758 return -EINVAL;
759 lock_sock(&(cf_sk->sk));
760 cf_sk->conn_req.priority = prio;
761 release_sock(&cf_sk->sk);
762 return 0;
763
764 case SO_BINDTODEVICE:
765 if (lvl != SOL_SOCKET)
766 goto bad_sol;
767 if (ol < sizeof(struct ifreq))
768 return -EINVAL;
769 if (copy_from_user(&ifreq, ov, sizeof(ifreq)))
770 return -EFAULT;
771 lock_sock(&(cf_sk->sk));
772 strncpy(cf_sk->conn_req.link_name, ifreq.ifr_name,
773 sizeof(cf_sk->conn_req.link_name));
774 cf_sk->conn_req.link_name
775 [sizeof(cf_sk->conn_req.link_name)-1] = 0;
776 release_sock(&cf_sk->sk);
777 return 0;
778
779 case CAIFSO_REQ_PARAM:
780 if (lvl != SOL_CAIF)
781 goto bad_sol;
782 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
783 return -ENOPROTOOPT;
784 lock_sock(&(cf_sk->sk));
785 cf_sk->conn_req.param.size = ol;
786 if (ol > sizeof(cf_sk->conn_req.param.data) ||
787 copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) {
788 release_sock(&cf_sk->sk);
789 return -EINVAL;
790 }
791 release_sock(&cf_sk->sk);
792 return 0;
793
794 default:
795 return -ENOPROTOOPT;
796 }
797
798 return 0;
799 bad_sol:
800 return -ENOPROTOOPT;
801
802 }
803
804 /*
805 * caif_connect() - Connect a CAIF Socket
806 * Copied and modified af_irda.c:irda_connect().
807 *
808 * Note : by consulting "errno", the user space caller may learn the cause
809 * of the failure. Most of them are visible in the function, others may come
810 * from subroutines called and are listed here :
811 * o -EAFNOSUPPORT: bad socket family or type.
812 * o -ESOCKTNOSUPPORT: bad socket type or protocol
813 * o -EINVAL: bad socket address, or CAIF link type
814 * o -ECONNREFUSED: remote end refused the connection.
815 * o -EINPROGRESS: connect request sent but timed out (or non-blocking)
816 * o -EISCONN: already connected.
817 * o -ETIMEDOUT: Connection timed out (send timeout)
818 * o -ENODEV: No link layer to send request
819 * o -ECONNRESET: Received Shutdown indication or lost link layer
820 * o -ENOMEM: Out of memory
821 *
822 * State Strategy:
823 * o sk_state: holds the CAIF_* protocol state, it's updated by
824 * caif_ctrl_cb.
825 * o sock->state: holds the SS_* socket state and is updated by connect and
826 * disconnect.
827 */
828 static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
829 int addr_len, int flags)
830 {
831 struct sock *sk = sock->sk;
832 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
833 long timeo;
834 int err;
835 lock_sock(sk);
836
837 err = -EAFNOSUPPORT;
838 if (uaddr->sa_family != AF_CAIF)
839 goto out;
840
841 err = -ESOCKTNOSUPPORT;
842 if (unlikely(!(sk->sk_type == SOCK_STREAM &&
843 cf_sk->sk.sk_protocol == CAIFPROTO_AT) &&
844 sk->sk_type != SOCK_SEQPACKET))
845 goto out;
846 switch (sock->state) {
847 case SS_UNCONNECTED:
848 /* Normal case, a fresh connect */
849 caif_assert(sk->sk_state == CAIF_DISCONNECTED);
850 break;
851 case SS_CONNECTING:
852 switch (sk->sk_state) {
853 case CAIF_CONNECTED:
854 sock->state = SS_CONNECTED;
855 err = -EISCONN;
856 goto out;
857 case CAIF_DISCONNECTED:
858 /* Reconnect allowed */
859 break;
860 case CAIF_CONNECTING:
861 err = -EALREADY;
862 if (flags & O_NONBLOCK)
863 goto out;
864 goto wait_connect;
865 }
866 break;
867 case SS_CONNECTED:
868 caif_assert(sk->sk_state == CAIF_CONNECTED ||
869 sk->sk_state == CAIF_DISCONNECTED);
870 if (sk->sk_shutdown & SHUTDOWN_MASK) {
871 /* Allow re-connect after SHUTDOWN_IND */
872 caif_disconnect_client(&cf_sk->layer);
873 break;
874 }
875 /* No reconnect on a seqpacket socket */
876 err = -EISCONN;
877 goto out;
878 case SS_DISCONNECTING:
879 case SS_FREE:
880 caif_assert(1); /*Should never happen */
881 break;
882 }
883 sk->sk_state = CAIF_DISCONNECTED;
884 sock->state = SS_UNCONNECTED;
885 sk_stream_kill_queues(&cf_sk->sk);
886
887 err = -EINVAL;
888 if (addr_len != sizeof(struct sockaddr_caif) ||
889 !uaddr)
890 goto out;
891
892 memcpy(&cf_sk->conn_req.sockaddr, uaddr,
893 sizeof(struct sockaddr_caif));
894
895 /* Move to connecting socket, start sending Connect Requests */
896 sock->state = SS_CONNECTING;
897 sk->sk_state = CAIF_CONNECTING;
898
899 dbfs_atomic_inc(&cnt.num_connect_req);
900 cf_sk->layer.receive = caif_sktrecv_cb;
901 err = caif_connect_client(&cf_sk->conn_req,
902 &cf_sk->layer);
903 if (err < 0) {
904 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
905 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
906 goto out;
907 }
908
909 err = -EINPROGRESS;
910 wait_connect:
911
912 if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
913 goto out;
914
915 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
916
917 release_sock(sk);
918 err = -ERESTARTSYS;
919 timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
920 sk->sk_state != CAIF_CONNECTING,
921 timeo);
922 lock_sock(sk);
923 if (timeo < 0)
924 goto out; /* -ERESTARTSYS */
925
926 err = -ETIMEDOUT;
927 if (timeo == 0 && sk->sk_state != CAIF_CONNECTED)
928 goto out;
929 if (sk->sk_state != CAIF_CONNECTED) {
930 sock->state = SS_UNCONNECTED;
931 err = sock_error(sk);
932 if (!err)
933 err = -ECONNREFUSED;
934 goto out;
935 }
936 sock->state = SS_CONNECTED;
937 err = 0;
938 out:
939 release_sock(sk);
940 return err;
941 }
942
943 /*
944 * caif_release() - Disconnect a CAIF Socket
945 * Copied and modified af_irda.c:irda_release().
946 */
947 static int caif_release(struct socket *sock)
948 {
949 struct sock *sk = sock->sk;
950 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
951 int res = 0;
952
953 if (!sk)
954 return 0;
955
956 set_tx_flow_off(cf_sk);
957
958 /*
959 * Ensure that packets are not queued after this point in time.
960 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
961 * this ensures no packets when sock is dead.
962 */
963 spin_lock(&sk->sk_receive_queue.lock);
964 sock_set_flag(sk, SOCK_DEAD);
965 spin_unlock(&sk->sk_receive_queue.lock);
966 sock->sk = NULL;
967
968 dbfs_atomic_inc(&cnt.num_disconnect);
969
970 if (cf_sk->debugfs_socket_dir != NULL)
971 debugfs_remove_recursive(cf_sk->debugfs_socket_dir);
972
973 lock_sock(&(cf_sk->sk));
974 sk->sk_state = CAIF_DISCONNECTED;
975 sk->sk_shutdown = SHUTDOWN_MASK;
976
977 if (cf_sk->sk.sk_socket->state == SS_CONNECTED ||
978 cf_sk->sk.sk_socket->state == SS_CONNECTING)
979 res = caif_disconnect_client(&cf_sk->layer);
980
981 cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
982 wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP);
983
984 sock_orphan(sk);
985 cf_sk->layer.dn = NULL;
986 sk_stream_kill_queues(&cf_sk->sk);
987 release_sock(sk);
988 sock_put(sk);
989 return res;
990 }
991
992 /* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */
993 static unsigned int caif_poll(struct file *file,
994 struct socket *sock, poll_table *wait)
995 {
996 struct sock *sk = sock->sk;
997 unsigned int mask;
998 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
999
1000 sock_poll_wait(file, sk_sleep(sk), wait);
1001 mask = 0;
1002
1003 /* exceptional events? */
1004 if (sk->sk_err)
1005 mask |= POLLERR;
1006 if (sk->sk_shutdown == SHUTDOWN_MASK)
1007 mask |= POLLHUP;
1008 if (sk->sk_shutdown & RCV_SHUTDOWN)
1009 mask |= POLLRDHUP;
1010
1011 /* readable? */
1012 if (!skb_queue_empty(&sk->sk_receive_queue) ||
1013 (sk->sk_shutdown & RCV_SHUTDOWN))
1014 mask |= POLLIN | POLLRDNORM;
1015
1016 /*
1017 * we set writable also when the other side has shut down the
1018 * connection. This prevents stuck sockets.
1019 */
1020 if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
1021 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1022
1023 return mask;
1024 }
1025
1026 static const struct proto_ops caif_seqpacket_ops = {
1027 .family = PF_CAIF,
1028 .owner = THIS_MODULE,
1029 .release = caif_release,
1030 .bind = sock_no_bind,
1031 .connect = caif_connect,
1032 .socketpair = sock_no_socketpair,
1033 .accept = sock_no_accept,
1034 .getname = sock_no_getname,
1035 .poll = caif_poll,
1036 .ioctl = sock_no_ioctl,
1037 .listen = sock_no_listen,
1038 .shutdown = sock_no_shutdown,
1039 .setsockopt = setsockopt,
1040 .getsockopt = sock_no_getsockopt,
1041 .sendmsg = caif_seqpkt_sendmsg,
1042 .recvmsg = caif_seqpkt_recvmsg,
1043 .mmap = sock_no_mmap,
1044 .sendpage = sock_no_sendpage,
1045 };
1046
1047 static const struct proto_ops caif_stream_ops = {
1048 .family = PF_CAIF,
1049 .owner = THIS_MODULE,
1050 .release = caif_release,
1051 .bind = sock_no_bind,
1052 .connect = caif_connect,
1053 .socketpair = sock_no_socketpair,
1054 .accept = sock_no_accept,
1055 .getname = sock_no_getname,
1056 .poll = caif_poll,
1057 .ioctl = sock_no_ioctl,
1058 .listen = sock_no_listen,
1059 .shutdown = sock_no_shutdown,
1060 .setsockopt = setsockopt,
1061 .getsockopt = sock_no_getsockopt,
1062 .sendmsg = caif_stream_sendmsg,
1063 .recvmsg = caif_stream_recvmsg,
1064 .mmap = sock_no_mmap,
1065 .sendpage = sock_no_sendpage,
1066 };
1067
1068 /* This function is called when a socket is finally destroyed. */
1069 static void caif_sock_destructor(struct sock *sk)
1070 {
1071 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1072 caif_assert(!atomic_read(&sk->sk_wmem_alloc));
1073 caif_assert(sk_unhashed(sk));
1074 caif_assert(!sk->sk_socket);
1075 if (!sock_flag(sk, SOCK_DEAD)) {
1076 pr_info("Attempt to release alive CAIF socket: %p\n", sk);
1077 return;
1078 }
1079 sk_stream_kill_queues(&cf_sk->sk);
1080 dbfs_atomic_dec(&cnt.caif_nr_socks);
1081 }
1082
1083 static int caif_create(struct net *net, struct socket *sock, int protocol,
1084 int kern)
1085 {
1086 struct sock *sk = NULL;
1087 struct caifsock *cf_sk = NULL;
1088 static struct proto prot = {.name = "PF_CAIF",
1089 .owner = THIS_MODULE,
1090 .obj_size = sizeof(struct caifsock),
1091 };
1092
1093 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
1094 return -EPERM;
1095 /*
1096 * The sock->type specifies the socket type to use.
1097 * The CAIF socket is a packet stream in the sense
1098 * that it is packet based. CAIF trusts the reliability
1099 * of the link, no resending is implemented.
1100 */
1101 if (sock->type == SOCK_SEQPACKET)
1102 sock->ops = &caif_seqpacket_ops;
1103 else if (sock->type == SOCK_STREAM)
1104 sock->ops = &caif_stream_ops;
1105 else
1106 return -ESOCKTNOSUPPORT;
1107
1108 if (protocol < 0 || protocol >= CAIFPROTO_MAX)
1109 return -EPROTONOSUPPORT;
1110 /*
1111 * Set the socket state to unconnected. The socket state
1112 * is really not used at all in the net/core or socket.c but the
1113 * initialization makes sure that sock->state is not uninitialized.
1114 */
1115 sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot);
1116 if (!sk)
1117 return -ENOMEM;
1118
1119 cf_sk = container_of(sk, struct caifsock, sk);
1120
1121 /* Store the protocol */
1122 sk->sk_protocol = (unsigned char) protocol;
1123
1124 /* Sendbuf dictates the amount of outbound packets not yet sent */
1125 sk->sk_sndbuf = CAIF_DEF_SNDBUF;
1126 sk->sk_rcvbuf = CAIF_DEF_RCVBUF;
1127
1128 /*
1129 * Lock in order to try to stop someone from opening the socket
1130 * too early.
1131 */
1132 lock_sock(&(cf_sk->sk));
1133
1134 /* Initialize the nozero default sock structure data. */
1135 sock_init_data(sock, sk);
1136 sk->sk_destruct = caif_sock_destructor;
1137
1138 mutex_init(&cf_sk->readlock); /* single task reading lock */
1139 cf_sk->layer.ctrlcmd = caif_ctrl_cb;
1140 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
1141 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
1142
1143 set_tx_flow_off(cf_sk);
1144 set_rx_flow_on(cf_sk);
1145
1146 /* Set default options on configuration */
1147 cf_sk->conn_req.priority = CAIF_PRIO_NORMAL;
1148 cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1149 cf_sk->conn_req.protocol = protocol;
1150 /* Increase the number of sockets created. */
1151 dbfs_atomic_inc(&cnt.caif_nr_socks);
1152 #ifdef CONFIG_DEBUG_FS
1153 if (!IS_ERR(debugfsdir)) {
1154 /* Fill in some information concerning the misc socket. */
1155 snprintf(cf_sk->name, sizeof(cf_sk->name), "cfsk%d",
1156 atomic_read(&cnt.caif_nr_socks));
1157
1158 cf_sk->debugfs_socket_dir =
1159 debugfs_create_dir(cf_sk->name, debugfsdir);
1160 debugfs_create_u32("sk_state", S_IRUSR | S_IWUSR,
1161 cf_sk->debugfs_socket_dir,
1162 (u32 *) &cf_sk->sk.sk_state);
1163 debugfs_create_u32("flow_state", S_IRUSR | S_IWUSR,
1164 cf_sk->debugfs_socket_dir, &cf_sk->flow_state);
1165 debugfs_create_u32("sk_rmem_alloc", S_IRUSR | S_IWUSR,
1166 cf_sk->debugfs_socket_dir,
1167 (u32 *) &cf_sk->sk.sk_rmem_alloc);
1168 debugfs_create_u32("sk_wmem_alloc", S_IRUSR | S_IWUSR,
1169 cf_sk->debugfs_socket_dir,
1170 (u32 *) &cf_sk->sk.sk_wmem_alloc);
1171 debugfs_create_u32("identity", S_IRUSR | S_IWUSR,
1172 cf_sk->debugfs_socket_dir,
1173 (u32 *) &cf_sk->layer.id);
1174 }
1175 #endif
1176 release_sock(&cf_sk->sk);
1177 return 0;
1178 }
1179
1180
1181 static struct net_proto_family caif_family_ops = {
1182 .family = PF_CAIF,
1183 .create = caif_create,
1184 .owner = THIS_MODULE,
1185 };
1186
1187 static int af_caif_init(void)
1188 {
1189 int err = sock_register(&caif_family_ops);
1190 if (!err)
1191 return err;
1192 return 0;
1193 }
1194
1195 static int __init caif_sktinit_module(void)
1196 {
1197 #ifdef CONFIG_DEBUG_FS
1198 debugfsdir = debugfs_create_dir("caif_sk", NULL);
1199 if (!IS_ERR(debugfsdir)) {
1200 debugfs_create_u32("num_sockets", S_IRUSR | S_IWUSR,
1201 debugfsdir,
1202 (u32 *) &cnt.caif_nr_socks);
1203 debugfs_create_u32("num_connect_req", S_IRUSR | S_IWUSR,
1204 debugfsdir,
1205 (u32 *) &cnt.num_connect_req);
1206 debugfs_create_u32("num_connect_resp", S_IRUSR | S_IWUSR,
1207 debugfsdir,
1208 (u32 *) &cnt.num_connect_resp);
1209 debugfs_create_u32("num_connect_fail_resp", S_IRUSR | S_IWUSR,
1210 debugfsdir,
1211 (u32 *) &cnt.num_connect_fail_resp);
1212 debugfs_create_u32("num_disconnect", S_IRUSR | S_IWUSR,
1213 debugfsdir,
1214 (u32 *) &cnt.num_disconnect);
1215 debugfs_create_u32("num_remote_shutdown_ind",
1216 S_IRUSR | S_IWUSR, debugfsdir,
1217 (u32 *) &cnt.num_remote_shutdown_ind);
1218 debugfs_create_u32("num_tx_flow_off_ind", S_IRUSR | S_IWUSR,
1219 debugfsdir,
1220 (u32 *) &cnt.num_tx_flow_off_ind);
1221 debugfs_create_u32("num_tx_flow_on_ind", S_IRUSR | S_IWUSR,
1222 debugfsdir,
1223 (u32 *) &cnt.num_tx_flow_on_ind);
1224 debugfs_create_u32("num_rx_flow_off", S_IRUSR | S_IWUSR,
1225 debugfsdir,
1226 (u32 *) &cnt.num_rx_flow_off);
1227 debugfs_create_u32("num_rx_flow_on", S_IRUSR | S_IWUSR,
1228 debugfsdir,
1229 (u32 *) &cnt.num_rx_flow_on);
1230 }
1231 #endif
1232 return af_caif_init();
1233 }
1234
1235 static void __exit caif_sktexit_module(void)
1236 {
1237 sock_unregister(PF_CAIF);
1238 if (debugfsdir != NULL)
1239 debugfs_remove_recursive(debugfsdir);
1240 }
1241 module_init(caif_sktinit_module);
1242 module_exit(caif_sktexit_module);
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