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Linux 4.1.16
[linux/fpc-iii.git] / net / caif / caif_socket.c
blob112ad784838a5bf6b46eed6c2b90f2d8b0e50d7a
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 unsigned long flags;
128 struct sk_buff_head *list = &sk->sk_receive_queue;
129 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
130
131 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
132 (unsigned int)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) {
133 net_dbg_ratelimited("sending flow OFF (queue len = %d %d)\n",
134 atomic_read(&cf_sk->sk.sk_rmem_alloc),
135 sk_rcvbuf_lowwater(cf_sk));
136 set_rx_flow_off(cf_sk);
137 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
138 }
139
140 err = sk_filter(sk, skb);
141 if (err)
142 return err;
143 if (!sk_rmem_schedule(sk, skb, skb->truesize) && rx_flow_is_on(cf_sk)) {
144 set_rx_flow_off(cf_sk);
145 net_dbg_ratelimited("sending flow OFF due to rmem_schedule\n");
146 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
147 }
148 skb->dev = NULL;
149 skb_set_owner_r(skb, sk);
150 /* Cache the SKB length before we tack it onto the receive
151 * queue. Once it is added it no longer belongs to us and
152 * may be freed by other threads of control pulling packets
153 * from the queue.
154 */
155 spin_lock_irqsave(&list->lock, flags);
156 if (!sock_flag(sk, SOCK_DEAD))
157 __skb_queue_tail(list, skb);
158 spin_unlock_irqrestore(&list->lock, flags);
159
160 if (!sock_flag(sk, SOCK_DEAD))
161 sk->sk_data_ready(sk);
162 else
163 kfree_skb(skb);
164 return 0;
165 }
166
167 /* Packet Receive Callback function called from CAIF Stack */
168 static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
169 {
170 struct caifsock *cf_sk;
171 struct sk_buff *skb;
172
173 cf_sk = container_of(layr, struct caifsock, layer);
174 skb = cfpkt_tonative(pkt);
175
176 if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) {
177 kfree_skb(skb);
178 return 0;
179 }
180 caif_queue_rcv_skb(&cf_sk->sk, skb);
181 return 0;
182 }
183
184 static void cfsk_hold(struct cflayer *layr)
185 {
186 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
187 sock_hold(&cf_sk->sk);
188 }
189
190 static void cfsk_put(struct cflayer *layr)
191 {
192 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
193 sock_put(&cf_sk->sk);
194 }
195
196 /* Packet Control Callback function called from CAIF */
197 static void caif_ctrl_cb(struct cflayer *layr,
198 enum caif_ctrlcmd flow,
199 int phyid)
200 {
201 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
202 switch (flow) {
203 case CAIF_CTRLCMD_FLOW_ON_IND:
204 /* OK from modem to start sending again */
205 set_tx_flow_on(cf_sk);
206 cf_sk->sk.sk_state_change(&cf_sk->sk);
207 break;
208
209 case CAIF_CTRLCMD_FLOW_OFF_IND:
210 /* Modem asks us to shut up */
211 set_tx_flow_off(cf_sk);
212 cf_sk->sk.sk_state_change(&cf_sk->sk);
213 break;
214
215 case CAIF_CTRLCMD_INIT_RSP:
216 /* We're now connected */
217 caif_client_register_refcnt(&cf_sk->layer,
218 cfsk_hold, cfsk_put);
219 cf_sk->sk.sk_state = CAIF_CONNECTED;
220 set_tx_flow_on(cf_sk);
221 cf_sk->sk.sk_shutdown = 0;
222 cf_sk->sk.sk_state_change(&cf_sk->sk);
223 break;
224
225 case CAIF_CTRLCMD_DEINIT_RSP:
226 /* We're now disconnected */
227 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
228 cf_sk->sk.sk_state_change(&cf_sk->sk);
229 break;
230
231 case CAIF_CTRLCMD_INIT_FAIL_RSP:
232 /* Connect request failed */
233 cf_sk->sk.sk_err = ECONNREFUSED;
234 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
235 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
236 /*
237 * Socket "standards" seems to require POLLOUT to
238 * be set at connect failure.
239 */
240 set_tx_flow_on(cf_sk);
241 cf_sk->sk.sk_state_change(&cf_sk->sk);
242 break;
243
244 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
245 /* Modem has closed this connection, or device is down. */
246 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
247 cf_sk->sk.sk_err = ECONNRESET;
248 set_rx_flow_on(cf_sk);
249 cf_sk->sk.sk_error_report(&cf_sk->sk);
250 break;
251
252 default:
253 pr_debug("Unexpected flow command %d\n", flow);
254 }
255 }
256
257 static void caif_check_flow_release(struct sock *sk)
258 {
259 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
260
261 if (rx_flow_is_on(cf_sk))
262 return;
263
264 if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) {
265 set_rx_flow_on(cf_sk);
266 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ);
267 }
268 }
269
270 /*
271 * Copied from unix_dgram_recvmsg, but removed credit checks,
272 * changed locking, address handling and added MSG_TRUNC.
273 */
274 static int caif_seqpkt_recvmsg(struct socket *sock, struct msghdr *m,
275 size_t len, int flags)
276
277 {
278 struct sock *sk = sock->sk;
279 struct sk_buff *skb;
280 int ret;
281 int copylen;
282
283 ret = -EOPNOTSUPP;
284 if (flags & MSG_OOB)
285 goto read_error;
286
287 skb = skb_recv_datagram(sk, flags, 0 , &ret);
288 if (!skb)
289 goto read_error;
290 copylen = skb->len;
291 if (len < copylen) {
292 m->msg_flags |= MSG_TRUNC;
293 copylen = len;
294 }
295
296 ret = skb_copy_datagram_msg(skb, 0, m, copylen);
297 if (ret)
298 goto out_free;
299
300 ret = (flags & MSG_TRUNC) ? skb->len : copylen;
301 out_free:
302 skb_free_datagram(sk, skb);
303 caif_check_flow_release(sk);
304 return ret;
305
306 read_error:
307 return ret;
308 }
309
310
311 /* Copied from unix_stream_wait_data, identical except for lock call. */
312 static long caif_stream_data_wait(struct sock *sk, long timeo)
313 {
314 DEFINE_WAIT(wait);
315 lock_sock(sk);
316
317 for (;;) {
318 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
319
320 if (!skb_queue_empty(&sk->sk_receive_queue) ||
321 sk->sk_err ||
322 sk->sk_state != CAIF_CONNECTED ||
323 sock_flag(sk, SOCK_DEAD) ||
324 (sk->sk_shutdown & RCV_SHUTDOWN) ||
325 signal_pending(current) ||
326 !timeo)
327 break;
328
329 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
330 release_sock(sk);
331 timeo = schedule_timeout(timeo);
332 lock_sock(sk);
333
334 if (sock_flag(sk, SOCK_DEAD))
335 break;
336
337 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
338 }
339
340 finish_wait(sk_sleep(sk), &wait);
341 release_sock(sk);
342 return timeo;
343 }
344
345
346 /*
347 * Copied from unix_stream_recvmsg, but removed credit checks,
348 * changed locking calls, changed address handling.
349 */
350 static int caif_stream_recvmsg(struct socket *sock, struct msghdr *msg,
351 size_t size, int flags)
352 {
353 struct sock *sk = sock->sk;
354 int copied = 0;
355 int target;
356 int err = 0;
357 long timeo;
358
359 err = -EOPNOTSUPP;
360 if (flags&MSG_OOB)
361 goto out;
362
363 /*
364 * Lock the socket to prevent queue disordering
365 * while sleeps in memcpy_tomsg
366 */
367 err = -EAGAIN;
368 if (sk->sk_state == CAIF_CONNECTING)
369 goto out;
370
371 caif_read_lock(sk);
372 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
373 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
374
375 do {
376 int chunk;
377 struct sk_buff *skb;
378
379 lock_sock(sk);
380 if (sock_flag(sk, SOCK_DEAD)) {
381 err = -ECONNRESET;
382 goto unlock;
383 }
384 skb = skb_dequeue(&sk->sk_receive_queue);
385 caif_check_flow_release(sk);
386
387 if (skb == NULL) {
388 if (copied >= target)
389 goto unlock;
390 /*
391 * POSIX 1003.1g mandates this order.
392 */
393 err = sock_error(sk);
394 if (err)
395 goto unlock;
396 err = -ECONNRESET;
397 if (sk->sk_shutdown & RCV_SHUTDOWN)
398 goto unlock;
399
400 err = -EPIPE;
401 if (sk->sk_state != CAIF_CONNECTED)
402 goto unlock;
403 if (sock_flag(sk, SOCK_DEAD))
404 goto unlock;
405
406 release_sock(sk);
407
408 err = -EAGAIN;
409 if (!timeo)
410 break;
411
412 caif_read_unlock(sk);
413
414 timeo = caif_stream_data_wait(sk, timeo);
415
416 if (signal_pending(current)) {
417 err = sock_intr_errno(timeo);
418 goto out;
419 }
420 caif_read_lock(sk);
421 continue;
422 unlock:
423 release_sock(sk);
424 break;
425 }
426 release_sock(sk);
427 chunk = min_t(unsigned int, skb->len, size);
428 if (memcpy_to_msg(msg, skb->data, chunk)) {
429 skb_queue_head(&sk->sk_receive_queue, skb);
430 if (copied == 0)
431 copied = -EFAULT;
432 break;
433 }
434 copied += chunk;
435 size -= chunk;
436
437 /* Mark read part of skb as used */
438 if (!(flags & MSG_PEEK)) {
439 skb_pull(skb, chunk);
440
441 /* put the skb back if we didn't use it up. */
442 if (skb->len) {
443 skb_queue_head(&sk->sk_receive_queue, skb);
444 break;
445 }
446 kfree_skb(skb);
447
448 } else {
449 /*
450 * It is questionable, see note in unix_dgram_recvmsg.
451 */
452 /* put message back and return */
453 skb_queue_head(&sk->sk_receive_queue, skb);
454 break;
455 }
456 } while (size);
457 caif_read_unlock(sk);
458
459 out:
460 return copied ? : err;
461 }
462
463 /*
464 * Copied from sock.c:sock_wait_for_wmem, but change to wait for
465 * CAIF flow-on and sock_writable.
466 */
467 static long caif_wait_for_flow_on(struct caifsock *cf_sk,
468 int wait_writeable, long timeo, int *err)
469 {
470 struct sock *sk = &cf_sk->sk;
471 DEFINE_WAIT(wait);
472 for (;;) {
473 *err = 0;
474 if (tx_flow_is_on(cf_sk) &&
475 (!wait_writeable || sock_writeable(&cf_sk->sk)))
476 break;
477 *err = -ETIMEDOUT;
478 if (!timeo)
479 break;
480 *err = -ERESTARTSYS;
481 if (signal_pending(current))
482 break;
483 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
484 *err = -ECONNRESET;
485 if (sk->sk_shutdown & SHUTDOWN_MASK)
486 break;
487 *err = -sk->sk_err;
488 if (sk->sk_err)
489 break;
490 *err = -EPIPE;
491 if (cf_sk->sk.sk_state != CAIF_CONNECTED)
492 break;
493 timeo = schedule_timeout(timeo);
494 }
495 finish_wait(sk_sleep(sk), &wait);
496 return timeo;
497 }
498
499 /*
500 * Transmit a SKB. The device may temporarily request re-transmission
501 * by returning EAGAIN.
502 */
503 static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk,
504 int noblock, long timeo)
505 {
506 struct cfpkt *pkt;
507
508 pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb);
509 memset(skb->cb, 0, sizeof(struct caif_payload_info));
510 cfpkt_set_prio(pkt, cf_sk->sk.sk_priority);
511
512 if (cf_sk->layer.dn == NULL) {
513 kfree_skb(skb);
514 return -EINVAL;
515 }
516
517 return cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
518 }
519
520 /* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
521 static int caif_seqpkt_sendmsg(struct socket *sock, struct msghdr *msg,
522 size_t len)
523 {
524 struct sock *sk = sock->sk;
525 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
526 int buffer_size;
527 int ret = 0;
528 struct sk_buff *skb = NULL;
529 int noblock;
530 long timeo;
531 caif_assert(cf_sk);
532 ret = sock_error(sk);
533 if (ret)
534 goto err;
535
536 ret = -EOPNOTSUPP;
537 if (msg->msg_flags&MSG_OOB)
538 goto err;
539
540 ret = -EOPNOTSUPP;
541 if (msg->msg_namelen)
542 goto err;
543
544 ret = -EINVAL;
545 if (unlikely(msg->msg_iter.iov->iov_base == NULL))
546 goto err;
547 noblock = msg->msg_flags & MSG_DONTWAIT;
548
549 timeo = sock_sndtimeo(sk, noblock);
550 timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
551 1, timeo, &ret);
552
553 if (ret)
554 goto err;
555 ret = -EPIPE;
556 if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
557 sock_flag(sk, SOCK_DEAD) ||
558 (sk->sk_shutdown & RCV_SHUTDOWN))
559 goto err;
560
561 /* Error if trying to write more than maximum frame size. */
562 ret = -EMSGSIZE;
563 if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM)
564 goto err;
565
566 buffer_size = len + cf_sk->headroom + cf_sk->tailroom;
567
568 ret = -ENOMEM;
569 skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
570
571 if (!skb || skb_tailroom(skb) < buffer_size)
572 goto err;
573
574 skb_reserve(skb, cf_sk->headroom);
575
576 ret = memcpy_from_msg(skb_put(skb, len), msg, len);
577
578 if (ret)
579 goto err;
580 ret = transmit_skb(skb, cf_sk, noblock, timeo);
581 if (ret < 0)
582 /* skb is already freed */
583 return ret;
584
585 return len;
586 err:
587 kfree_skb(skb);
588 return ret;
589 }
590
591 /*
592 * Copied from unix_stream_sendmsg and adapted to CAIF:
593 * Changed removed permission handling and added waiting for flow on
594 * and other minor adaptations.
595 */
596 static int caif_stream_sendmsg(struct socket *sock, struct msghdr *msg,
597 size_t len)
598 {
599 struct sock *sk = sock->sk;
600 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
601 int err, size;
602 struct sk_buff *skb;
603 int sent = 0;
604 long timeo;
605
606 err = -EOPNOTSUPP;
607 if (unlikely(msg->msg_flags&MSG_OOB))
608 goto out_err;
609
610 if (unlikely(msg->msg_namelen))
611 goto out_err;
612
613 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
614 timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
615
616 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
617 goto pipe_err;
618
619 while (sent < len) {
620
621 size = len-sent;
622
623 if (size > cf_sk->maxframe)
624 size = cf_sk->maxframe;
625
626 /* If size is more than half of sndbuf, chop up message */
627 if (size > ((sk->sk_sndbuf >> 1) - 64))
628 size = (sk->sk_sndbuf >> 1) - 64;
629
630 if (size > SKB_MAX_ALLOC)
631 size = SKB_MAX_ALLOC;
632
633 skb = sock_alloc_send_skb(sk,
634 size + cf_sk->headroom +
635 cf_sk->tailroom,
636 msg->msg_flags&MSG_DONTWAIT,
637 &err);
638 if (skb == NULL)
639 goto out_err;
640
641 skb_reserve(skb, cf_sk->headroom);
642 /*
643 * If you pass two values to the sock_alloc_send_skb
644 * it tries to grab the large buffer with GFP_NOFS
645 * (which can fail easily), and if it fails grab the
646 * fallback size buffer which is under a page and will
647 * succeed. [Alan]
648 */
649 size = min_t(int, size, skb_tailroom(skb));
650
651 err = memcpy_from_msg(skb_put(skb, size), msg, size);
652 if (err) {
653 kfree_skb(skb);
654 goto out_err;
655 }
656 err = transmit_skb(skb, cf_sk,
657 msg->msg_flags&MSG_DONTWAIT, timeo);
658 if (err < 0)
659 /* skb is already freed */
660 goto pipe_err;
661
662 sent += size;
663 }
664
665 return sent;
666
667 pipe_err:
668 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
669 send_sig(SIGPIPE, current, 0);
670 err = -EPIPE;
671 out_err:
672 return sent ? : err;
673 }
674
675 static int setsockopt(struct socket *sock,
676 int lvl, int opt, char __user *ov, unsigned int ol)
677 {
678 struct sock *sk = sock->sk;
679 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
680 int linksel;
681
682 if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
683 return -ENOPROTOOPT;
684
685 switch (opt) {
686 case CAIFSO_LINK_SELECT:
687 if (ol < sizeof(int))
688 return -EINVAL;
689 if (lvl != SOL_CAIF)
690 goto bad_sol;
691 if (copy_from_user(&linksel, ov, sizeof(int)))
692 return -EINVAL;
693 lock_sock(&(cf_sk->sk));
694 cf_sk->conn_req.link_selector = linksel;
695 release_sock(&cf_sk->sk);
696 return 0;
697
698 case CAIFSO_REQ_PARAM:
699 if (lvl != SOL_CAIF)
700 goto bad_sol;
701 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
702 return -ENOPROTOOPT;
703 lock_sock(&(cf_sk->sk));
704 if (ol > sizeof(cf_sk->conn_req.param.data) ||
705 copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) {
706 release_sock(&cf_sk->sk);
707 return -EINVAL;
708 }
709 cf_sk->conn_req.param.size = ol;
710 release_sock(&cf_sk->sk);
711 return 0;
712
713 default:
714 return -ENOPROTOOPT;
715 }
716
717 return 0;
718 bad_sol:
719 return -ENOPROTOOPT;
720
721 }
722
723 /*
724 * caif_connect() - Connect a CAIF Socket
725 * Copied and modified af_irda.c:irda_connect().
726 *
727 * Note : by consulting "errno", the user space caller may learn the cause
728 * of the failure. Most of them are visible in the function, others may come
729 * from subroutines called and are listed here :
730 * o -EAFNOSUPPORT: bad socket family or type.
731 * o -ESOCKTNOSUPPORT: bad socket type or protocol
732 * o -EINVAL: bad socket address, or CAIF link type
733 * o -ECONNREFUSED: remote end refused the connection.
734 * o -EINPROGRESS: connect request sent but timed out (or non-blocking)
735 * o -EISCONN: already connected.
736 * o -ETIMEDOUT: Connection timed out (send timeout)
737 * o -ENODEV: No link layer to send request
738 * o -ECONNRESET: Received Shutdown indication or lost link layer
739 * o -ENOMEM: Out of memory
740 *
741 * State Strategy:
742 * o sk_state: holds the CAIF_* protocol state, it's updated by
743 * caif_ctrl_cb.
744 * o sock->state: holds the SS_* socket state and is updated by connect and
745 * disconnect.
746 */
747 static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
748 int addr_len, int flags)
749 {
750 struct sock *sk = sock->sk;
751 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
752 long timeo;
753 int err;
754 int ifindex, headroom, tailroom;
755 unsigned int mtu;
756 struct net_device *dev;
757
758 lock_sock(sk);
759
760 err = -EAFNOSUPPORT;
761 if (uaddr->sa_family != AF_CAIF)
762 goto out;
763
764 switch (sock->state) {
765 case SS_UNCONNECTED:
766 /* Normal case, a fresh connect */
767 caif_assert(sk->sk_state == CAIF_DISCONNECTED);
768 break;
769 case SS_CONNECTING:
770 switch (sk->sk_state) {
771 case CAIF_CONNECTED:
772 sock->state = SS_CONNECTED;
773 err = -EISCONN;
774 goto out;
775 case CAIF_DISCONNECTED:
776 /* Reconnect allowed */
777 break;
778 case CAIF_CONNECTING:
779 err = -EALREADY;
780 if (flags & O_NONBLOCK)
781 goto out;
782 goto wait_connect;
783 }
784 break;
785 case SS_CONNECTED:
786 caif_assert(sk->sk_state == CAIF_CONNECTED ||
787 sk->sk_state == CAIF_DISCONNECTED);
788 if (sk->sk_shutdown & SHUTDOWN_MASK) {
789 /* Allow re-connect after SHUTDOWN_IND */
790 caif_disconnect_client(sock_net(sk), &cf_sk->layer);
791 caif_free_client(&cf_sk->layer);
792 break;
793 }
794 /* No reconnect on a seqpacket socket */
795 err = -EISCONN;
796 goto out;
797 case SS_DISCONNECTING:
798 case SS_FREE:
799 caif_assert(1); /*Should never happen */
800 break;
801 }
802 sk->sk_state = CAIF_DISCONNECTED;
803 sock->state = SS_UNCONNECTED;
804 sk_stream_kill_queues(&cf_sk->sk);
805
806 err = -EINVAL;
807 if (addr_len != sizeof(struct sockaddr_caif))
808 goto out;
809
810 memcpy(&cf_sk->conn_req.sockaddr, uaddr,
811 sizeof(struct sockaddr_caif));
812
813 /* Move to connecting socket, start sending Connect Requests */
814 sock->state = SS_CONNECTING;
815 sk->sk_state = CAIF_CONNECTING;
816
817 /* Check priority value comming from socket */
818 /* if priority value is out of range it will be ajusted */
819 if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX)
820 cf_sk->conn_req.priority = CAIF_PRIO_MAX;
821 else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN)
822 cf_sk->conn_req.priority = CAIF_PRIO_MIN;
823 else
824 cf_sk->conn_req.priority = cf_sk->sk.sk_priority;
825
826 /*ifindex = id of the interface.*/
827 cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if;
828
829 cf_sk->layer.receive = caif_sktrecv_cb;
830
831 err = caif_connect_client(sock_net(sk), &cf_sk->conn_req,
832 &cf_sk->layer, &ifindex, &headroom, &tailroom);
833
834 if (err < 0) {
835 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
836 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
837 goto out;
838 }
839
840 err = -ENODEV;
841 rcu_read_lock();
842 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
843 if (!dev) {
844 rcu_read_unlock();
845 goto out;
846 }
847 cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom);
848 mtu = dev->mtu;
849 rcu_read_unlock();
850
851 cf_sk->tailroom = tailroom;
852 cf_sk->maxframe = mtu - (headroom + tailroom);
853 if (cf_sk->maxframe < 1) {
854 pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu);
855 err = -ENODEV;
856 goto out;
857 }
858
859 err = -EINPROGRESS;
860 wait_connect:
861
862 if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
863 goto out;
864
865 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
866
867 release_sock(sk);
868 err = -ERESTARTSYS;
869 timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
870 sk->sk_state != CAIF_CONNECTING,
871 timeo);
872 lock_sock(sk);
873 if (timeo < 0)
874 goto out; /* -ERESTARTSYS */
875
876 err = -ETIMEDOUT;
877 if (timeo == 0 && sk->sk_state != CAIF_CONNECTED)
878 goto out;
879 if (sk->sk_state != CAIF_CONNECTED) {
880 sock->state = SS_UNCONNECTED;
881 err = sock_error(sk);
882 if (!err)
883 err = -ECONNREFUSED;
884 goto out;
885 }
886 sock->state = SS_CONNECTED;
887 err = 0;
888 out:
889 release_sock(sk);
890 return err;
891 }
892
893 /*
894 * caif_release() - Disconnect a CAIF Socket
895 * Copied and modified af_irda.c:irda_release().
896 */
897 static int caif_release(struct socket *sock)
898 {
899 struct sock *sk = sock->sk;
900 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
901
902 if (!sk)
903 return 0;
904
905 set_tx_flow_off(cf_sk);
906
907 /*
908 * Ensure that packets are not queued after this point in time.
909 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
910 * this ensures no packets when sock is dead.
911 */
912 spin_lock_bh(&sk->sk_receive_queue.lock);
913 sock_set_flag(sk, SOCK_DEAD);
914 spin_unlock_bh(&sk->sk_receive_queue.lock);
915 sock->sk = NULL;
916
917 WARN_ON(IS_ERR(cf_sk->debugfs_socket_dir));
918 debugfs_remove_recursive(cf_sk->debugfs_socket_dir);
919
920 lock_sock(&(cf_sk->sk));
921 sk->sk_state = CAIF_DISCONNECTED;
922 sk->sk_shutdown = SHUTDOWN_MASK;
923
924 caif_disconnect_client(sock_net(sk), &cf_sk->layer);
925 cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
926 wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP);
927
928 sock_orphan(sk);
929 sk_stream_kill_queues(&cf_sk->sk);
930 release_sock(sk);
931 sock_put(sk);
932 return 0;
933 }
934
935 /* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */
936 static unsigned int caif_poll(struct file *file,
937 struct socket *sock, poll_table *wait)
938 {
939 struct sock *sk = sock->sk;
940 unsigned int mask;
941 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
942
943 sock_poll_wait(file, sk_sleep(sk), wait);
944 mask = 0;
945
946 /* exceptional events? */
947 if (sk->sk_err)
948 mask |= POLLERR;
949 if (sk->sk_shutdown == SHUTDOWN_MASK)
950 mask |= POLLHUP;
951 if (sk->sk_shutdown & RCV_SHUTDOWN)
952 mask |= POLLRDHUP;
953
954 /* readable? */
955 if (!skb_queue_empty(&sk->sk_receive_queue) ||
956 (sk->sk_shutdown & RCV_SHUTDOWN))
957 mask |= POLLIN | POLLRDNORM;
958
959 /*
960 * we set writable also when the other side has shut down the
961 * connection. This prevents stuck sockets.
962 */
963 if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
964 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
965
966 return mask;
967 }
968
969 static const struct proto_ops caif_seqpacket_ops = {
970 .family = PF_CAIF,
971 .owner = THIS_MODULE,
972 .release = caif_release,
973 .bind = sock_no_bind,
974 .connect = caif_connect,
975 .socketpair = sock_no_socketpair,
976 .accept = sock_no_accept,
977 .getname = sock_no_getname,
978 .poll = caif_poll,
979 .ioctl = sock_no_ioctl,
980 .listen = sock_no_listen,
981 .shutdown = sock_no_shutdown,
982 .setsockopt = setsockopt,
983 .getsockopt = sock_no_getsockopt,
984 .sendmsg = caif_seqpkt_sendmsg,
985 .recvmsg = caif_seqpkt_recvmsg,
986 .mmap = sock_no_mmap,
987 .sendpage = sock_no_sendpage,
988 };
989
990 static const struct proto_ops caif_stream_ops = {
991 .family = PF_CAIF,
992 .owner = THIS_MODULE,
993 .release = caif_release,
994 .bind = sock_no_bind,
995 .connect = caif_connect,
996 .socketpair = sock_no_socketpair,
997 .accept = sock_no_accept,
998 .getname = sock_no_getname,
999 .poll = caif_poll,
1000 .ioctl = sock_no_ioctl,
1001 .listen = sock_no_listen,
1002 .shutdown = sock_no_shutdown,
1003 .setsockopt = setsockopt,
1004 .getsockopt = sock_no_getsockopt,
1005 .sendmsg = caif_stream_sendmsg,
1006 .recvmsg = caif_stream_recvmsg,
1007 .mmap = sock_no_mmap,
1008 .sendpage = sock_no_sendpage,
1009 };
1010
1011 /* This function is called when a socket is finally destroyed. */
1012 static void caif_sock_destructor(struct sock *sk)
1013 {
1014 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1015 caif_assert(!atomic_read(&sk->sk_wmem_alloc));
1016 caif_assert(sk_unhashed(sk));
1017 caif_assert(!sk->sk_socket);
1018 if (!sock_flag(sk, SOCK_DEAD)) {
1019 pr_debug("Attempt to release alive CAIF socket: %p\n", sk);
1020 return;
1021 }
1022 sk_stream_kill_queues(&cf_sk->sk);
1023 caif_free_client(&cf_sk->layer);
1024 }
1025
1026 static int caif_create(struct net *net, struct socket *sock, int protocol,
1027 int kern)
1028 {
1029 struct sock *sk = NULL;
1030 struct caifsock *cf_sk = NULL;
1031 static struct proto prot = {.name = "PF_CAIF",
1032 .owner = THIS_MODULE,
1033 .obj_size = sizeof(struct caifsock),
1034 };
1035
1036 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
1037 return -EPERM;
1038 /*
1039 * The sock->type specifies the socket type to use.
1040 * The CAIF socket is a packet stream in the sense
1041 * that it is packet based. CAIF trusts the reliability
1042 * of the link, no resending is implemented.
1043 */
1044 if (sock->type == SOCK_SEQPACKET)
1045 sock->ops = &caif_seqpacket_ops;
1046 else if (sock->type == SOCK_STREAM)
1047 sock->ops = &caif_stream_ops;
1048 else
1049 return -ESOCKTNOSUPPORT;
1050
1051 if (protocol < 0 || protocol >= CAIFPROTO_MAX)
1052 return -EPROTONOSUPPORT;
1053 /*
1054 * Set the socket state to unconnected. The socket state
1055 * is really not used at all in the net/core or socket.c but the
1056 * initialization makes sure that sock->state is not uninitialized.
1057 */
1058 sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot);
1059 if (!sk)
1060 return -ENOMEM;
1061
1062 cf_sk = container_of(sk, struct caifsock, sk);
1063
1064 /* Store the protocol */
1065 sk->sk_protocol = (unsigned char) protocol;
1066
1067 /* Initialize default priority for well-known cases */
1068 switch (protocol) {
1069 case CAIFPROTO_AT:
1070 sk->sk_priority = TC_PRIO_CONTROL;
1071 break;
1072 case CAIFPROTO_RFM:
1073 sk->sk_priority = TC_PRIO_INTERACTIVE_BULK;
1074 break;
1075 default:
1076 sk->sk_priority = TC_PRIO_BESTEFFORT;
1077 }
1078
1079 /*
1080 * Lock in order to try to stop someone from opening the socket
1081 * too early.
1082 */
1083 lock_sock(&(cf_sk->sk));
1084
1085 /* Initialize the nozero default sock structure data. */
1086 sock_init_data(sock, sk);
1087 sk->sk_destruct = caif_sock_destructor;
1088
1089 mutex_init(&cf_sk->readlock); /* single task reading lock */
1090 cf_sk->layer.ctrlcmd = caif_ctrl_cb;
1091 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
1092 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
1093
1094 set_tx_flow_off(cf_sk);
1095 set_rx_flow_on(cf_sk);
1096
1097 /* Set default options on configuration */
1098 cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1099 cf_sk->conn_req.protocol = protocol;
1100 release_sock(&cf_sk->sk);
1101 return 0;
1102 }
1103
1104
1105 static struct net_proto_family caif_family_ops = {
1106 .family = PF_CAIF,
1107 .create = caif_create,
1108 .owner = THIS_MODULE,
1109 };
1110
1111 static int __init caif_sktinit_module(void)
1112 {
1113 int err = sock_register(&caif_family_ops);
1114 if (!err)
1115 return err;
1116 return 0;
1117 }
1118
1119 static void __exit caif_sktexit_module(void)
1120 {
1121 sock_unregister(PF_CAIF);
1122 }
1123 module_init(caif_sktinit_module);
1124 module_exit(caif_sktexit_module);
Linux with added FPC-III support