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Linux 3.12.70
[linux/fpc-iii.git] / net / caif / caif_socket.c
blobafeb8e07ee41c44639222557f5272eaca26900b7
1 /*
2 * Copyright (C) ST-Ericsson AB 2010
3 * Author: Sjur Brendeland
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/pkt_sched.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 struct caifsock {
47 struct sock sk; /* must be first member */
48 struct cflayer layer;
49 u32 flow_state;
50 struct caif_connect_request conn_req;
51 struct mutex readlock;
52 struct dentry *debugfs_socket_dir;
53 int headroom, tailroom, maxframe;
54 };
55
56 static int rx_flow_is_on(struct caifsock *cf_sk)
57 {
58 return test_bit(RX_FLOW_ON_BIT,
59 (void *) &cf_sk->flow_state);
60 }
61
62 static int tx_flow_is_on(struct caifsock *cf_sk)
63 {
64 return test_bit(TX_FLOW_ON_BIT,
65 (void *) &cf_sk->flow_state);
66 }
67
68 static void set_rx_flow_off(struct caifsock *cf_sk)
69 {
70 clear_bit(RX_FLOW_ON_BIT,
71 (void *) &cf_sk->flow_state);
72 }
73
74 static void set_rx_flow_on(struct caifsock *cf_sk)
75 {
76 set_bit(RX_FLOW_ON_BIT,
77 (void *) &cf_sk->flow_state);
78 }
79
80 static void set_tx_flow_off(struct caifsock *cf_sk)
81 {
82 clear_bit(TX_FLOW_ON_BIT,
83 (void *) &cf_sk->flow_state);
84 }
85
86 static void set_tx_flow_on(struct caifsock *cf_sk)
87 {
88 set_bit(TX_FLOW_ON_BIT,
89 (void *) &cf_sk->flow_state);
90 }
91
92 static void caif_read_lock(struct sock *sk)
93 {
94 struct caifsock *cf_sk;
95 cf_sk = container_of(sk, struct caifsock, sk);
96 mutex_lock(&cf_sk->readlock);
97 }
98
99 static void caif_read_unlock(struct sock *sk)
100 {
101 struct caifsock *cf_sk;
102 cf_sk = container_of(sk, struct caifsock, sk);
103 mutex_unlock(&cf_sk->readlock);
104 }
105
106 static int sk_rcvbuf_lowwater(struct caifsock *cf_sk)
107 {
108 /* A quarter of full buffer is used a low water mark */
109 return cf_sk->sk.sk_rcvbuf / 4;
110 }
111
112 static void caif_flow_ctrl(struct sock *sk, int mode)
113 {
114 struct caifsock *cf_sk;
115 cf_sk = container_of(sk, struct caifsock, sk);
116 if (cf_sk->layer.dn && cf_sk->layer.dn->modemcmd)
117 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, mode);
118 }
119
120 /*
121 * Copied from sock.c:sock_queue_rcv_skb(), but changed so packets are
122 * not dropped, but CAIF is sending flow off instead.
123 */
124 static int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
125 {
126 int err;
127 int skb_len;
128 unsigned long flags;
129 struct sk_buff_head *list = &sk->sk_receive_queue;
130 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
131
132 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
133 (unsigned int)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) {
134 net_dbg_ratelimited("sending flow OFF (queue len = %d %d)\n",
135 atomic_read(&cf_sk->sk.sk_rmem_alloc),
136 sk_rcvbuf_lowwater(cf_sk));
137 set_rx_flow_off(cf_sk);
138 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
139 }
140
141 err = sk_filter(sk, skb);
142 if (err)
143 return err;
144 if (!sk_rmem_schedule(sk, skb, skb->truesize) && rx_flow_is_on(cf_sk)) {
145 set_rx_flow_off(cf_sk);
146 net_dbg_ratelimited("sending flow OFF due to rmem_schedule\n");
147 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
148 }
149 skb->dev = NULL;
150 skb_set_owner_r(skb, sk);
151 /* Cache the SKB length before we tack it onto the receive
152 * queue. Once it is added it no longer belongs to us and
153 * may be freed by other threads of control pulling packets
154 * from the queue.
155 */
156 skb_len = skb->len;
157 spin_lock_irqsave(&list->lock, flags);
158 if (!sock_flag(sk, SOCK_DEAD))
159 __skb_queue_tail(list, skb);
160 spin_unlock_irqrestore(&list->lock, flags);
161
162 if (!sock_flag(sk, SOCK_DEAD))
163 sk->sk_data_ready(sk, skb_len);
164 else
165 kfree_skb(skb);
166 return 0;
167 }
168
169 /* Packet Receive Callback function called from CAIF Stack */
170 static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
171 {
172 struct caifsock *cf_sk;
173 struct sk_buff *skb;
174
175 cf_sk = container_of(layr, struct caifsock, layer);
176 skb = cfpkt_tonative(pkt);
177
178 if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) {
179 kfree_skb(skb);
180 return 0;
181 }
182 caif_queue_rcv_skb(&cf_sk->sk, skb);
183 return 0;
184 }
185
186 static void cfsk_hold(struct cflayer *layr)
187 {
188 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
189 sock_hold(&cf_sk->sk);
190 }
191
192 static void cfsk_put(struct cflayer *layr)
193 {
194 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
195 sock_put(&cf_sk->sk);
196 }
197
198 /* Packet Control Callback function called from CAIF */
199 static void caif_ctrl_cb(struct cflayer *layr,
200 enum caif_ctrlcmd flow,
201 int phyid)
202 {
203 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
204 switch (flow) {
205 case CAIF_CTRLCMD_FLOW_ON_IND:
206 /* OK from modem to start sending again */
207 set_tx_flow_on(cf_sk);
208 cf_sk->sk.sk_state_change(&cf_sk->sk);
209 break;
210
211 case CAIF_CTRLCMD_FLOW_OFF_IND:
212 /* Modem asks us to shut up */
213 set_tx_flow_off(cf_sk);
214 cf_sk->sk.sk_state_change(&cf_sk->sk);
215 break;
216
217 case CAIF_CTRLCMD_INIT_RSP:
218 /* We're now connected */
219 caif_client_register_refcnt(&cf_sk->layer,
220 cfsk_hold, cfsk_put);
221 cf_sk->sk.sk_state = CAIF_CONNECTED;
222 set_tx_flow_on(cf_sk);
223 cf_sk->sk.sk_shutdown = 0;
224 cf_sk->sk.sk_state_change(&cf_sk->sk);
225 break;
226
227 case CAIF_CTRLCMD_DEINIT_RSP:
228 /* We're now disconnected */
229 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
230 cf_sk->sk.sk_state_change(&cf_sk->sk);
231 break;
232
233 case CAIF_CTRLCMD_INIT_FAIL_RSP:
234 /* Connect request failed */
235 cf_sk->sk.sk_err = ECONNREFUSED;
236 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
237 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
238 /*
239 * Socket "standards" seems to require POLLOUT to
240 * be set at connect failure.
241 */
242 set_tx_flow_on(cf_sk);
243 cf_sk->sk.sk_state_change(&cf_sk->sk);
244 break;
245
246 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
247 /* Modem has closed this connection, or device is down. */
248 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
249 cf_sk->sk.sk_err = ECONNRESET;
250 set_rx_flow_on(cf_sk);
251 cf_sk->sk.sk_error_report(&cf_sk->sk);
252 break;
253
254 default:
255 pr_debug("Unexpected flow command %d\n", flow);
256 }
257 }
258
259 static void caif_check_flow_release(struct sock *sk)
260 {
261 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
262
263 if (rx_flow_is_on(cf_sk))
264 return;
265
266 if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) {
267 set_rx_flow_on(cf_sk);
268 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ);
269 }
270 }
271
272 /*
273 * Copied from unix_dgram_recvmsg, but removed credit checks,
274 * changed locking, address handling and added MSG_TRUNC.
275 */
276 static int caif_seqpkt_recvmsg(struct kiocb *iocb, struct socket *sock,
277 struct msghdr *m, size_t len, int flags)
278
279 {
280 struct sock *sk = sock->sk;
281 struct sk_buff *skb;
282 int ret;
283 int copylen;
284
285 ret = -EOPNOTSUPP;
286 if (flags & MSG_OOB)
287 goto read_error;
288
289 skb = skb_recv_datagram(sk, flags, 0 , &ret);
290 if (!skb)
291 goto read_error;
292 copylen = skb->len;
293 if (len < copylen) {
294 m->msg_flags |= MSG_TRUNC;
295 copylen = len;
296 }
297
298 ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, copylen);
299 if (ret)
300 goto out_free;
301
302 ret = (flags & MSG_TRUNC) ? skb->len : copylen;
303 out_free:
304 skb_free_datagram(sk, skb);
305 caif_check_flow_release(sk);
306 return ret;
307
308 read_error:
309 return ret;
310 }
311
312
313 /* Copied from unix_stream_wait_data, identical except for lock call. */
314 static long caif_stream_data_wait(struct sock *sk, long timeo)
315 {
316 DEFINE_WAIT(wait);
317 lock_sock(sk);
318
319 for (;;) {
320 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
321
322 if (!skb_queue_empty(&sk->sk_receive_queue) ||
323 sk->sk_err ||
324 sk->sk_state != CAIF_CONNECTED ||
325 sock_flag(sk, SOCK_DEAD) ||
326 (sk->sk_shutdown & RCV_SHUTDOWN) ||
327 signal_pending(current) ||
328 !timeo)
329 break;
330
331 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
332 release_sock(sk);
333 timeo = schedule_timeout(timeo);
334 lock_sock(sk);
335
336 if (sock_flag(sk, SOCK_DEAD))
337 break;
338
339 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
340 }
341
342 finish_wait(sk_sleep(sk), &wait);
343 release_sock(sk);
344 return timeo;
345 }
346
347
348 /*
349 * Copied from unix_stream_recvmsg, but removed credit checks,
350 * changed locking calls, changed address handling.
351 */
352 static int caif_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
353 struct msghdr *msg, size_t size,
354 int flags)
355 {
356 struct sock *sk = sock->sk;
357 int copied = 0;
358 int target;
359 int err = 0;
360 long timeo;
361
362 err = -EOPNOTSUPP;
363 if (flags&MSG_OOB)
364 goto out;
365
366 /*
367 * Lock the socket to prevent queue disordering
368 * while sleeps in memcpy_tomsg
369 */
370 err = -EAGAIN;
371 if (sk->sk_state == CAIF_CONNECTING)
372 goto out;
373
374 caif_read_lock(sk);
375 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
376 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
377
378 do {
379 int chunk;
380 struct sk_buff *skb;
381
382 lock_sock(sk);
383 if (sock_flag(sk, SOCK_DEAD)) {
384 err = -ECONNRESET;
385 goto unlock;
386 }
387 skb = skb_dequeue(&sk->sk_receive_queue);
388 caif_check_flow_release(sk);
389
390 if (skb == NULL) {
391 if (copied >= target)
392 goto unlock;
393 /*
394 * POSIX 1003.1g mandates this order.
395 */
396 err = sock_error(sk);
397 if (err)
398 goto unlock;
399 err = -ECONNRESET;
400 if (sk->sk_shutdown & RCV_SHUTDOWN)
401 goto unlock;
402
403 err = -EPIPE;
404 if (sk->sk_state != CAIF_CONNECTED)
405 goto unlock;
406 if (sock_flag(sk, SOCK_DEAD))
407 goto unlock;
408
409 release_sock(sk);
410
411 err = -EAGAIN;
412 if (!timeo)
413 break;
414
415 caif_read_unlock(sk);
416
417 timeo = caif_stream_data_wait(sk, timeo);
418
419 if (signal_pending(current)) {
420 err = sock_intr_errno(timeo);
421 goto out;
422 }
423 caif_read_lock(sk);
424 continue;
425 unlock:
426 release_sock(sk);
427 break;
428 }
429 release_sock(sk);
430 chunk = min_t(unsigned int, skb->len, size);
431 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
432 skb_queue_head(&sk->sk_receive_queue, skb);
433 if (copied == 0)
434 copied = -EFAULT;
435 break;
436 }
437 copied += chunk;
438 size -= chunk;
439
440 /* Mark read part of skb as used */
441 if (!(flags & MSG_PEEK)) {
442 skb_pull(skb, chunk);
443
444 /* put the skb back if we didn't use it up. */
445 if (skb->len) {
446 skb_queue_head(&sk->sk_receive_queue, skb);
447 break;
448 }
449 kfree_skb(skb);
450
451 } else {
452 /*
453 * It is questionable, see note in unix_dgram_recvmsg.
454 */
455 /* put message back and return */
456 skb_queue_head(&sk->sk_receive_queue, skb);
457 break;
458 }
459 } while (size);
460 caif_read_unlock(sk);
461
462 out:
463 return copied ? : err;
464 }
465
466 /*
467 * Copied from sock.c:sock_wait_for_wmem, but change to wait for
468 * CAIF flow-on and sock_writable.
469 */
470 static long caif_wait_for_flow_on(struct caifsock *cf_sk,
471 int wait_writeable, long timeo, int *err)
472 {
473 struct sock *sk = &cf_sk->sk;
474 DEFINE_WAIT(wait);
475 for (;;) {
476 *err = 0;
477 if (tx_flow_is_on(cf_sk) &&
478 (!wait_writeable || sock_writeable(&cf_sk->sk)))
479 break;
480 *err = -ETIMEDOUT;
481 if (!timeo)
482 break;
483 *err = -ERESTARTSYS;
484 if (signal_pending(current))
485 break;
486 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
487 *err = -ECONNRESET;
488 if (sk->sk_shutdown & SHUTDOWN_MASK)
489 break;
490 *err = -sk->sk_err;
491 if (sk->sk_err)
492 break;
493 *err = -EPIPE;
494 if (cf_sk->sk.sk_state != CAIF_CONNECTED)
495 break;
496 timeo = schedule_timeout(timeo);
497 }
498 finish_wait(sk_sleep(sk), &wait);
499 return timeo;
500 }
501
502 /*
503 * Transmit a SKB. The device may temporarily request re-transmission
504 * by returning EAGAIN.
505 */
506 static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk,
507 int noblock, long timeo)
508 {
509 struct cfpkt *pkt;
510
511 pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb);
512 memset(skb->cb, 0, sizeof(struct caif_payload_info));
513 cfpkt_set_prio(pkt, cf_sk->sk.sk_priority);
514
515 if (cf_sk->layer.dn == NULL) {
516 kfree_skb(skb);
517 return -EINVAL;
518 }
519
520 return cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
521 }
522
523 /* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
524 static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock,
525 struct msghdr *msg, size_t len)
526 {
527 struct sock *sk = sock->sk;
528 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
529 int buffer_size;
530 int ret = 0;
531 struct sk_buff *skb = NULL;
532 int noblock;
533 long timeo;
534 caif_assert(cf_sk);
535 ret = sock_error(sk);
536 if (ret)
537 goto err;
538
539 ret = -EOPNOTSUPP;
540 if (msg->msg_flags&MSG_OOB)
541 goto err;
542
543 ret = -EOPNOTSUPP;
544 if (msg->msg_namelen)
545 goto err;
546
547 ret = -EINVAL;
548 if (unlikely(msg->msg_iov->iov_base == NULL))
549 goto err;
550 noblock = msg->msg_flags & MSG_DONTWAIT;
551
552 timeo = sock_sndtimeo(sk, noblock);
553 timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
554 1, timeo, &ret);
555
556 if (ret)
557 goto err;
558 ret = -EPIPE;
559 if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
560 sock_flag(sk, SOCK_DEAD) ||
561 (sk->sk_shutdown & RCV_SHUTDOWN))
562 goto err;
563
564 /* Error if trying to write more than maximum frame size. */
565 ret = -EMSGSIZE;
566 if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM)
567 goto err;
568
569 buffer_size = len + cf_sk->headroom + cf_sk->tailroom;
570
571 ret = -ENOMEM;
572 skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
573
574 if (!skb || skb_tailroom(skb) < buffer_size)
575 goto err;
576
577 skb_reserve(skb, cf_sk->headroom);
578
579 ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
580
581 if (ret)
582 goto err;
583 ret = transmit_skb(skb, cf_sk, noblock, timeo);
584 if (ret < 0)
585 /* skb is already freed */
586 return ret;
587
588 return len;
589 err:
590 kfree_skb(skb);
591 return ret;
592 }
593
594 /*
595 * Copied from unix_stream_sendmsg and adapted to CAIF:
596 * Changed removed permission handling and added waiting for flow on
597 * and other minor adaptations.
598 */
599 static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
600 struct msghdr *msg, size_t len)
601 {
602 struct sock *sk = sock->sk;
603 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
604 int err, size;
605 struct sk_buff *skb;
606 int sent = 0;
607 long timeo;
608
609 err = -EOPNOTSUPP;
610 if (unlikely(msg->msg_flags&MSG_OOB))
611 goto out_err;
612
613 if (unlikely(msg->msg_namelen))
614 goto out_err;
615
616 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
617 timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
618
619 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
620 goto pipe_err;
621
622 while (sent < len) {
623
624 size = len-sent;
625
626 if (size > cf_sk->maxframe)
627 size = cf_sk->maxframe;
628
629 /* If size is more than half of sndbuf, chop up message */
630 if (size > ((sk->sk_sndbuf >> 1) - 64))
631 size = (sk->sk_sndbuf >> 1) - 64;
632
633 if (size > SKB_MAX_ALLOC)
634 size = SKB_MAX_ALLOC;
635
636 skb = sock_alloc_send_skb(sk,
637 size + cf_sk->headroom +
638 cf_sk->tailroom,
639 msg->msg_flags&MSG_DONTWAIT,
640 &err);
641 if (skb == NULL)
642 goto out_err;
643
644 skb_reserve(skb, cf_sk->headroom);
645 /*
646 * If you pass two values to the sock_alloc_send_skb
647 * it tries to grab the large buffer with GFP_NOFS
648 * (which can fail easily), and if it fails grab the
649 * fallback size buffer which is under a page and will
650 * succeed. [Alan]
651 */
652 size = min_t(int, size, skb_tailroom(skb));
653
654 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
655 if (err) {
656 kfree_skb(skb);
657 goto out_err;
658 }
659 err = transmit_skb(skb, cf_sk,
660 msg->msg_flags&MSG_DONTWAIT, timeo);
661 if (err < 0)
662 /* skb is already freed */
663 goto pipe_err;
664
665 sent += size;
666 }
667
668 return sent;
669
670 pipe_err:
671 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
672 send_sig(SIGPIPE, current, 0);
673 err = -EPIPE;
674 out_err:
675 return sent ? : err;
676 }
677
678 static int setsockopt(struct socket *sock,
679 int lvl, int opt, char __user *ov, unsigned int ol)
680 {
681 struct sock *sk = sock->sk;
682 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
683 int linksel;
684
685 if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
686 return -ENOPROTOOPT;
687
688 switch (opt) {
689 case CAIFSO_LINK_SELECT:
690 if (ol < sizeof(int))
691 return -EINVAL;
692 if (lvl != SOL_CAIF)
693 goto bad_sol;
694 if (copy_from_user(&linksel, ov, sizeof(int)))
695 return -EINVAL;
696 lock_sock(&(cf_sk->sk));
697 cf_sk->conn_req.link_selector = linksel;
698 release_sock(&cf_sk->sk);
699 return 0;
700
701 case CAIFSO_REQ_PARAM:
702 if (lvl != SOL_CAIF)
703 goto bad_sol;
704 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
705 return -ENOPROTOOPT;
706 lock_sock(&(cf_sk->sk));
707 if (ol > sizeof(cf_sk->conn_req.param.data) ||
708 copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) {
709 release_sock(&cf_sk->sk);
710 return -EINVAL;
711 }
712 cf_sk->conn_req.param.size = ol;
713 release_sock(&cf_sk->sk);
714 return 0;
715
716 default:
717 return -ENOPROTOOPT;
718 }
719
720 return 0;
721 bad_sol:
722 return -ENOPROTOOPT;
723
724 }
725
726 /*
727 * caif_connect() - Connect a CAIF Socket
728 * Copied and modified af_irda.c:irda_connect().
729 *
730 * Note : by consulting "errno", the user space caller may learn the cause
731 * of the failure. Most of them are visible in the function, others may come
732 * from subroutines called and are listed here :
733 * o -EAFNOSUPPORT: bad socket family or type.
734 * o -ESOCKTNOSUPPORT: bad socket type or protocol
735 * o -EINVAL: bad socket address, or CAIF link type
736 * o -ECONNREFUSED: remote end refused the connection.
737 * o -EINPROGRESS: connect request sent but timed out (or non-blocking)
738 * o -EISCONN: already connected.
739 * o -ETIMEDOUT: Connection timed out (send timeout)
740 * o -ENODEV: No link layer to send request
741 * o -ECONNRESET: Received Shutdown indication or lost link layer
742 * o -ENOMEM: Out of memory
743 *
744 * State Strategy:
745 * o sk_state: holds the CAIF_* protocol state, it's updated by
746 * caif_ctrl_cb.
747 * o sock->state: holds the SS_* socket state and is updated by connect and
748 * disconnect.
749 */
750 static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
751 int addr_len, int flags)
752 {
753 struct sock *sk = sock->sk;
754 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
755 long timeo;
756 int err;
757 int ifindex, headroom, tailroom;
758 unsigned int mtu;
759 struct net_device *dev;
760
761 lock_sock(sk);
762
763 err = -EAFNOSUPPORT;
764 if (uaddr->sa_family != AF_CAIF)
765 goto out;
766
767 switch (sock->state) {
768 case SS_UNCONNECTED:
769 /* Normal case, a fresh connect */
770 caif_assert(sk->sk_state == CAIF_DISCONNECTED);
771 break;
772 case SS_CONNECTING:
773 switch (sk->sk_state) {
774 case CAIF_CONNECTED:
775 sock->state = SS_CONNECTED;
776 err = -EISCONN;
777 goto out;
778 case CAIF_DISCONNECTED:
779 /* Reconnect allowed */
780 break;
781 case CAIF_CONNECTING:
782 err = -EALREADY;
783 if (flags & O_NONBLOCK)
784 goto out;
785 goto wait_connect;
786 }
787 break;
788 case SS_CONNECTED:
789 caif_assert(sk->sk_state == CAIF_CONNECTED ||
790 sk->sk_state == CAIF_DISCONNECTED);
791 if (sk->sk_shutdown & SHUTDOWN_MASK) {
792 /* Allow re-connect after SHUTDOWN_IND */
793 caif_disconnect_client(sock_net(sk), &cf_sk->layer);
794 caif_free_client(&cf_sk->layer);
795 break;
796 }
797 /* No reconnect on a seqpacket socket */
798 err = -EISCONN;
799 goto out;
800 case SS_DISCONNECTING:
801 case SS_FREE:
802 caif_assert(1); /*Should never happen */
803 break;
804 }
805 sk->sk_state = CAIF_DISCONNECTED;
806 sock->state = SS_UNCONNECTED;
807 sk_stream_kill_queues(&cf_sk->sk);
808
809 err = -EINVAL;
810 if (addr_len != sizeof(struct sockaddr_caif))
811 goto out;
812
813 memcpy(&cf_sk->conn_req.sockaddr, uaddr,
814 sizeof(struct sockaddr_caif));
815
816 /* Move to connecting socket, start sending Connect Requests */
817 sock->state = SS_CONNECTING;
818 sk->sk_state = CAIF_CONNECTING;
819
820 /* Check priority value comming from socket */
821 /* if priority value is out of range it will be ajusted */
822 if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX)
823 cf_sk->conn_req.priority = CAIF_PRIO_MAX;
824 else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN)
825 cf_sk->conn_req.priority = CAIF_PRIO_MIN;
826 else
827 cf_sk->conn_req.priority = cf_sk->sk.sk_priority;
828
829 /*ifindex = id of the interface.*/
830 cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if;
831
832 cf_sk->layer.receive = caif_sktrecv_cb;
833
834 err = caif_connect_client(sock_net(sk), &cf_sk->conn_req,
835 &cf_sk->layer, &ifindex, &headroom, &tailroom);
836
837 if (err < 0) {
838 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
839 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
840 goto out;
841 }
842
843 err = -ENODEV;
844 rcu_read_lock();
845 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
846 if (!dev) {
847 rcu_read_unlock();
848 goto out;
849 }
850 cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom);
851 mtu = dev->mtu;
852 rcu_read_unlock();
853
854 cf_sk->tailroom = tailroom;
855 cf_sk->maxframe = mtu - (headroom + tailroom);
856 if (cf_sk->maxframe < 1) {
857 pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu);
858 err = -ENODEV;
859 goto out;
860 }
861
862 err = -EINPROGRESS;
863 wait_connect:
864
865 if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
866 goto out;
867
868 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
869
870 release_sock(sk);
871 err = -ERESTARTSYS;
872 timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
873 sk->sk_state != CAIF_CONNECTING,
874 timeo);
875 lock_sock(sk);
876 if (timeo < 0)
877 goto out; /* -ERESTARTSYS */
878
879 err = -ETIMEDOUT;
880 if (timeo == 0 && sk->sk_state != CAIF_CONNECTED)
881 goto out;
882 if (sk->sk_state != CAIF_CONNECTED) {
883 sock->state = SS_UNCONNECTED;
884 err = sock_error(sk);
885 if (!err)
886 err = -ECONNREFUSED;
887 goto out;
888 }
889 sock->state = SS_CONNECTED;
890 err = 0;
891 out:
892 release_sock(sk);
893 return err;
894 }
895
896 /*
897 * caif_release() - Disconnect a CAIF Socket
898 * Copied and modified af_irda.c:irda_release().
899 */
900 static int caif_release(struct socket *sock)
901 {
902 struct sock *sk = sock->sk;
903 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
904
905 if (!sk)
906 return 0;
907
908 set_tx_flow_off(cf_sk);
909
910 /*
911 * Ensure that packets are not queued after this point in time.
912 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
913 * this ensures no packets when sock is dead.
914 */
915 spin_lock_bh(&sk->sk_receive_queue.lock);
916 sock_set_flag(sk, SOCK_DEAD);
917 spin_unlock_bh(&sk->sk_receive_queue.lock);
918 sock->sk = NULL;
919
920 WARN_ON(IS_ERR(cf_sk->debugfs_socket_dir));
921 if (cf_sk->debugfs_socket_dir != NULL)
922 debugfs_remove_recursive(cf_sk->debugfs_socket_dir);
923
924 lock_sock(&(cf_sk->sk));
925 sk->sk_state = CAIF_DISCONNECTED;
926 sk->sk_shutdown = SHUTDOWN_MASK;
927
928 caif_disconnect_client(sock_net(sk), &cf_sk->layer);
929 cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
930 wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP);
931
932 sock_orphan(sk);
933 sk_stream_kill_queues(&cf_sk->sk);
934 release_sock(sk);
935 sock_put(sk);
936 return 0;
937 }
938
939 /* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */
940 static unsigned int caif_poll(struct file *file,
941 struct socket *sock, poll_table *wait)
942 {
943 struct sock *sk = sock->sk;
944 unsigned int mask;
945 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
946
947 sock_poll_wait(file, sk_sleep(sk), wait);
948 mask = 0;
949
950 /* exceptional events? */
951 if (sk->sk_err)
952 mask |= POLLERR;
953 if (sk->sk_shutdown == SHUTDOWN_MASK)
954 mask |= POLLHUP;
955 if (sk->sk_shutdown & RCV_SHUTDOWN)
956 mask |= POLLRDHUP;
957
958 /* readable? */
959 if (!skb_queue_empty(&sk->sk_receive_queue) ||
960 (sk->sk_shutdown & RCV_SHUTDOWN))
961 mask |= POLLIN | POLLRDNORM;
962
963 /*
964 * we set writable also when the other side has shut down the
965 * connection. This prevents stuck sockets.
966 */
967 if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
968 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
969
970 return mask;
971 }
972
973 static const struct proto_ops caif_seqpacket_ops = {
974 .family = PF_CAIF,
975 .owner = THIS_MODULE,
976 .release = caif_release,
977 .bind = sock_no_bind,
978 .connect = caif_connect,
979 .socketpair = sock_no_socketpair,
980 .accept = sock_no_accept,
981 .getname = sock_no_getname,
982 .poll = caif_poll,
983 .ioctl = sock_no_ioctl,
984 .listen = sock_no_listen,
985 .shutdown = sock_no_shutdown,
986 .setsockopt = setsockopt,
987 .getsockopt = sock_no_getsockopt,
988 .sendmsg = caif_seqpkt_sendmsg,
989 .recvmsg = caif_seqpkt_recvmsg,
990 .mmap = sock_no_mmap,
991 .sendpage = sock_no_sendpage,
992 };
993
994 static const struct proto_ops caif_stream_ops = {
995 .family = PF_CAIF,
996 .owner = THIS_MODULE,
997 .release = caif_release,
998 .bind = sock_no_bind,
999 .connect = caif_connect,
1000 .socketpair = sock_no_socketpair,
1001 .accept = sock_no_accept,
1002 .getname = sock_no_getname,
1003 .poll = caif_poll,
1004 .ioctl = sock_no_ioctl,
1005 .listen = sock_no_listen,
1006 .shutdown = sock_no_shutdown,
1007 .setsockopt = setsockopt,
1008 .getsockopt = sock_no_getsockopt,
1009 .sendmsg = caif_stream_sendmsg,
1010 .recvmsg = caif_stream_recvmsg,
1011 .mmap = sock_no_mmap,
1012 .sendpage = sock_no_sendpage,
1013 };
1014
1015 /* This function is called when a socket is finally destroyed. */
1016 static void caif_sock_destructor(struct sock *sk)
1017 {
1018 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1019 caif_assert(!atomic_read(&sk->sk_wmem_alloc));
1020 caif_assert(sk_unhashed(sk));
1021 caif_assert(!sk->sk_socket);
1022 if (!sock_flag(sk, SOCK_DEAD)) {
1023 pr_debug("Attempt to release alive CAIF socket: %p\n", sk);
1024 return;
1025 }
1026 sk_stream_kill_queues(&cf_sk->sk);
1027 caif_free_client(&cf_sk->layer);
1028 }
1029
1030 static int caif_create(struct net *net, struct socket *sock, int protocol,
1031 int kern)
1032 {
1033 struct sock *sk = NULL;
1034 struct caifsock *cf_sk = NULL;
1035 static struct proto prot = {.name = "PF_CAIF",
1036 .owner = THIS_MODULE,
1037 .obj_size = sizeof(struct caifsock),
1038 };
1039
1040 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
1041 return -EPERM;
1042 /*
1043 * The sock->type specifies the socket type to use.
1044 * The CAIF socket is a packet stream in the sense
1045 * that it is packet based. CAIF trusts the reliability
1046 * of the link, no resending is implemented.
1047 */
1048 if (sock->type == SOCK_SEQPACKET)
1049 sock->ops = &caif_seqpacket_ops;
1050 else if (sock->type == SOCK_STREAM)
1051 sock->ops = &caif_stream_ops;
1052 else
1053 return -ESOCKTNOSUPPORT;
1054
1055 if (protocol < 0 || protocol >= CAIFPROTO_MAX)
1056 return -EPROTONOSUPPORT;
1057 /*
1058 * Set the socket state to unconnected. The socket state
1059 * is really not used at all in the net/core or socket.c but the
1060 * initialization makes sure that sock->state is not uninitialized.
1061 */
1062 sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot);
1063 if (!sk)
1064 return -ENOMEM;
1065
1066 cf_sk = container_of(sk, struct caifsock, sk);
1067
1068 /* Store the protocol */
1069 sk->sk_protocol = (unsigned char) protocol;
1070
1071 /* Initialize default priority for well-known cases */
1072 switch (protocol) {
1073 case CAIFPROTO_AT:
1074 sk->sk_priority = TC_PRIO_CONTROL;
1075 break;
1076 case CAIFPROTO_RFM:
1077 sk->sk_priority = TC_PRIO_INTERACTIVE_BULK;
1078 break;
1079 default:
1080 sk->sk_priority = TC_PRIO_BESTEFFORT;
1081 }
1082
1083 /*
1084 * Lock in order to try to stop someone from opening the socket
1085 * too early.
1086 */
1087 lock_sock(&(cf_sk->sk));
1088
1089 /* Initialize the nozero default sock structure data. */
1090 sock_init_data(sock, sk);
1091 sk->sk_destruct = caif_sock_destructor;
1092
1093 mutex_init(&cf_sk->readlock); /* single task reading lock */
1094 cf_sk->layer.ctrlcmd = caif_ctrl_cb;
1095 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
1096 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
1097
1098 set_tx_flow_off(cf_sk);
1099 set_rx_flow_on(cf_sk);
1100
1101 /* Set default options on configuration */
1102 cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1103 cf_sk->conn_req.protocol = protocol;
1104 release_sock(&cf_sk->sk);
1105 return 0;
1106 }
1107
1108
1109 static struct net_proto_family caif_family_ops = {
1110 .family = PF_CAIF,
1111 .create = caif_create,
1112 .owner = THIS_MODULE,
1113 };
1114
1115 static int __init caif_sktinit_module(void)
1116 {
1117 int err = sock_register(&caif_family_ops);
1118 if (!err)
1119 return err;
1120 return 0;
1121 }
1122
1123 static void __exit caif_sktexit_module(void)
1124 {
1125 sock_unregister(PF_CAIF);
1126 }
1127 module_init(caif_sktinit_module);
1128 module_exit(caif_sktexit_module);
Linux with added FPC-III support