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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris...
[linux/fpc-iii.git] / net / caif / caif_socket.c
blobd6be3edb7a43493a18766c6824b0a1c9ac430d05
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 (m->msg_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 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
336 }
337
338 finish_wait(sk_sleep(sk), &wait);
339 release_sock(sk);
340 return timeo;
341 }
342
343
344 /*
345 * Copied from unix_stream_recvmsg, but removed credit checks,
346 * changed locking calls, changed address handling.
347 */
348 static int caif_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
349 struct msghdr *msg, size_t size,
350 int flags)
351 {
352 struct sock *sk = sock->sk;
353 int copied = 0;
354 int target;
355 int err = 0;
356 long timeo;
357
358 err = -EOPNOTSUPP;
359 if (flags&MSG_OOB)
360 goto out;
361
362 /*
363 * Lock the socket to prevent queue disordering
364 * while sleeps in memcpy_tomsg
365 */
366 err = -EAGAIN;
367 if (sk->sk_state == CAIF_CONNECTING)
368 goto out;
369
370 caif_read_lock(sk);
371 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
372 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
373
374 do {
375 int chunk;
376 struct sk_buff *skb;
377
378 lock_sock(sk);
379 skb = skb_dequeue(&sk->sk_receive_queue);
380 caif_check_flow_release(sk);
381
382 if (skb == NULL) {
383 if (copied >= target)
384 goto unlock;
385 /*
386 * POSIX 1003.1g mandates this order.
387 */
388 err = sock_error(sk);
389 if (err)
390 goto unlock;
391 err = -ECONNRESET;
392 if (sk->sk_shutdown & RCV_SHUTDOWN)
393 goto unlock;
394
395 err = -EPIPE;
396 if (sk->sk_state != CAIF_CONNECTED)
397 goto unlock;
398 if (sock_flag(sk, SOCK_DEAD))
399 goto unlock;
400
401 release_sock(sk);
402
403 err = -EAGAIN;
404 if (!timeo)
405 break;
406
407 caif_read_unlock(sk);
408
409 timeo = caif_stream_data_wait(sk, timeo);
410
411 if (signal_pending(current)) {
412 err = sock_intr_errno(timeo);
413 goto out;
414 }
415 caif_read_lock(sk);
416 continue;
417 unlock:
418 release_sock(sk);
419 break;
420 }
421 release_sock(sk);
422 chunk = min_t(unsigned int, skb->len, size);
423 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
424 skb_queue_head(&sk->sk_receive_queue, skb);
425 if (copied == 0)
426 copied = -EFAULT;
427 break;
428 }
429 copied += chunk;
430 size -= chunk;
431
432 /* Mark read part of skb as used */
433 if (!(flags & MSG_PEEK)) {
434 skb_pull(skb, chunk);
435
436 /* put the skb back if we didn't use it up. */
437 if (skb->len) {
438 skb_queue_head(&sk->sk_receive_queue, skb);
439 break;
440 }
441 kfree_skb(skb);
442
443 } else {
444 /*
445 * It is questionable, see note in unix_dgram_recvmsg.
446 */
447 /* put message back and return */
448 skb_queue_head(&sk->sk_receive_queue, skb);
449 break;
450 }
451 } while (size);
452 caif_read_unlock(sk);
453
454 out:
455 return copied ? : err;
456 }
457
458 /*
459 * Copied from sock.c:sock_wait_for_wmem, but change to wait for
460 * CAIF flow-on and sock_writable.
461 */
462 static long caif_wait_for_flow_on(struct caifsock *cf_sk,
463 int wait_writeable, long timeo, int *err)
464 {
465 struct sock *sk = &cf_sk->sk;
466 DEFINE_WAIT(wait);
467 for (;;) {
468 *err = 0;
469 if (tx_flow_is_on(cf_sk) &&
470 (!wait_writeable || sock_writeable(&cf_sk->sk)))
471 break;
472 *err = -ETIMEDOUT;
473 if (!timeo)
474 break;
475 *err = -ERESTARTSYS;
476 if (signal_pending(current))
477 break;
478 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
479 *err = -ECONNRESET;
480 if (sk->sk_shutdown & SHUTDOWN_MASK)
481 break;
482 *err = -sk->sk_err;
483 if (sk->sk_err)
484 break;
485 *err = -EPIPE;
486 if (cf_sk->sk.sk_state != CAIF_CONNECTED)
487 break;
488 timeo = schedule_timeout(timeo);
489 }
490 finish_wait(sk_sleep(sk), &wait);
491 return timeo;
492 }
493
494 /*
495 * Transmit a SKB. The device may temporarily request re-transmission
496 * by returning EAGAIN.
497 */
498 static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk,
499 int noblock, long timeo)
500 {
501 struct cfpkt *pkt;
502
503 pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb);
504 memset(skb->cb, 0, sizeof(struct caif_payload_info));
505 cfpkt_set_prio(pkt, cf_sk->sk.sk_priority);
506
507 if (cf_sk->layer.dn == NULL) {
508 kfree_skb(skb);
509 return -EINVAL;
510 }
511
512 return cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
513 }
514
515 /* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
516 static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock,
517 struct msghdr *msg, size_t len)
518 {
519 struct sock *sk = sock->sk;
520 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
521 int buffer_size;
522 int ret = 0;
523 struct sk_buff *skb = NULL;
524 int noblock;
525 long timeo;
526 caif_assert(cf_sk);
527 ret = sock_error(sk);
528 if (ret)
529 goto err;
530
531 ret = -EOPNOTSUPP;
532 if (msg->msg_flags&MSG_OOB)
533 goto err;
534
535 ret = -EOPNOTSUPP;
536 if (msg->msg_namelen)
537 goto err;
538
539 ret = -EINVAL;
540 if (unlikely(msg->msg_iov->iov_base == NULL))
541 goto err;
542 noblock = msg->msg_flags & MSG_DONTWAIT;
543
544 timeo = sock_sndtimeo(sk, noblock);
545 timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
546 1, timeo, &ret);
547
548 if (ret)
549 goto err;
550 ret = -EPIPE;
551 if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
552 sock_flag(sk, SOCK_DEAD) ||
553 (sk->sk_shutdown & RCV_SHUTDOWN))
554 goto err;
555
556 /* Error if trying to write more than maximum frame size. */
557 ret = -EMSGSIZE;
558 if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM)
559 goto err;
560
561 buffer_size = len + cf_sk->headroom + cf_sk->tailroom;
562
563 ret = -ENOMEM;
564 skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
565
566 if (!skb || skb_tailroom(skb) < buffer_size)
567 goto err;
568
569 skb_reserve(skb, cf_sk->headroom);
570
571 ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
572
573 if (ret)
574 goto err;
575 ret = transmit_skb(skb, cf_sk, noblock, timeo);
576 if (ret < 0)
577 /* skb is already freed */
578 return ret;
579
580 return len;
581 err:
582 kfree_skb(skb);
583 return ret;
584 }
585
586 /*
587 * Copied from unix_stream_sendmsg and adapted to CAIF:
588 * Changed removed permission handling and added waiting for flow on
589 * and other minor adaptations.
590 */
591 static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
592 struct msghdr *msg, size_t len)
593 {
594 struct sock *sk = sock->sk;
595 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
596 int err, size;
597 struct sk_buff *skb;
598 int sent = 0;
599 long timeo;
600
601 err = -EOPNOTSUPP;
602 if (unlikely(msg->msg_flags&MSG_OOB))
603 goto out_err;
604
605 if (unlikely(msg->msg_namelen))
606 goto out_err;
607
608 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
609 timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
610
611 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
612 goto pipe_err;
613
614 while (sent < len) {
615
616 size = len-sent;
617
618 if (size > cf_sk->maxframe)
619 size = cf_sk->maxframe;
620
621 /* If size is more than half of sndbuf, chop up message */
622 if (size > ((sk->sk_sndbuf >> 1) - 64))
623 size = (sk->sk_sndbuf >> 1) - 64;
624
625 if (size > SKB_MAX_ALLOC)
626 size = SKB_MAX_ALLOC;
627
628 skb = sock_alloc_send_skb(sk,
629 size + cf_sk->headroom +
630 cf_sk->tailroom,
631 msg->msg_flags&MSG_DONTWAIT,
632 &err);
633 if (skb == NULL)
634 goto out_err;
635
636 skb_reserve(skb, cf_sk->headroom);
637 /*
638 * If you pass two values to the sock_alloc_send_skb
639 * it tries to grab the large buffer with GFP_NOFS
640 * (which can fail easily), and if it fails grab the
641 * fallback size buffer which is under a page and will
642 * succeed. [Alan]
643 */
644 size = min_t(int, size, skb_tailroom(skb));
645
646 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
647 if (err) {
648 kfree_skb(skb);
649 goto out_err;
650 }
651 err = transmit_skb(skb, cf_sk,
652 msg->msg_flags&MSG_DONTWAIT, timeo);
653 if (err < 0)
654 /* skb is already freed */
655 goto pipe_err;
656
657 sent += size;
658 }
659
660 return sent;
661
662 pipe_err:
663 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
664 send_sig(SIGPIPE, current, 0);
665 err = -EPIPE;
666 out_err:
667 return sent ? : err;
668 }
669
670 static int setsockopt(struct socket *sock,
671 int lvl, int opt, char __user *ov, unsigned int ol)
672 {
673 struct sock *sk = sock->sk;
674 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
675 int linksel;
676
677 if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
678 return -ENOPROTOOPT;
679
680 switch (opt) {
681 case CAIFSO_LINK_SELECT:
682 if (ol < sizeof(int))
683 return -EINVAL;
684 if (lvl != SOL_CAIF)
685 goto bad_sol;
686 if (copy_from_user(&linksel, ov, sizeof(int)))
687 return -EINVAL;
688 lock_sock(&(cf_sk->sk));
689 cf_sk->conn_req.link_selector = linksel;
690 release_sock(&cf_sk->sk);
691 return 0;
692
693 case CAIFSO_REQ_PARAM:
694 if (lvl != SOL_CAIF)
695 goto bad_sol;
696 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
697 return -ENOPROTOOPT;
698 lock_sock(&(cf_sk->sk));
699 if (ol > sizeof(cf_sk->conn_req.param.data) ||
700 copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) {
701 release_sock(&cf_sk->sk);
702 return -EINVAL;
703 }
704 cf_sk->conn_req.param.size = ol;
705 release_sock(&cf_sk->sk);
706 return 0;
707
708 default:
709 return -ENOPROTOOPT;
710 }
711
712 return 0;
713 bad_sol:
714 return -ENOPROTOOPT;
715
716 }
717
718 /*
719 * caif_connect() - Connect a CAIF Socket
720 * Copied and modified af_irda.c:irda_connect().
721 *
722 * Note : by consulting "errno", the user space caller may learn the cause
723 * of the failure. Most of them are visible in the function, others may come
724 * from subroutines called and are listed here :
725 * o -EAFNOSUPPORT: bad socket family or type.
726 * o -ESOCKTNOSUPPORT: bad socket type or protocol
727 * o -EINVAL: bad socket address, or CAIF link type
728 * o -ECONNREFUSED: remote end refused the connection.
729 * o -EINPROGRESS: connect request sent but timed out (or non-blocking)
730 * o -EISCONN: already connected.
731 * o -ETIMEDOUT: Connection timed out (send timeout)
732 * o -ENODEV: No link layer to send request
733 * o -ECONNRESET: Received Shutdown indication or lost link layer
734 * o -ENOMEM: Out of memory
735 *
736 * State Strategy:
737 * o sk_state: holds the CAIF_* protocol state, it's updated by
738 * caif_ctrl_cb.
739 * o sock->state: holds the SS_* socket state and is updated by connect and
740 * disconnect.
741 */
742 static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
743 int addr_len, int flags)
744 {
745 struct sock *sk = sock->sk;
746 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
747 long timeo;
748 int err;
749 int ifindex, headroom, tailroom;
750 unsigned int mtu;
751 struct net_device *dev;
752
753 lock_sock(sk);
754
755 err = -EAFNOSUPPORT;
756 if (uaddr->sa_family != AF_CAIF)
757 goto out;
758
759 switch (sock->state) {
760 case SS_UNCONNECTED:
761 /* Normal case, a fresh connect */
762 caif_assert(sk->sk_state == CAIF_DISCONNECTED);
763 break;
764 case SS_CONNECTING:
765 switch (sk->sk_state) {
766 case CAIF_CONNECTED:
767 sock->state = SS_CONNECTED;
768 err = -EISCONN;
769 goto out;
770 case CAIF_DISCONNECTED:
771 /* Reconnect allowed */
772 break;
773 case CAIF_CONNECTING:
774 err = -EALREADY;
775 if (flags & O_NONBLOCK)
776 goto out;
777 goto wait_connect;
778 }
779 break;
780 case SS_CONNECTED:
781 caif_assert(sk->sk_state == CAIF_CONNECTED ||
782 sk->sk_state == CAIF_DISCONNECTED);
783 if (sk->sk_shutdown & SHUTDOWN_MASK) {
784 /* Allow re-connect after SHUTDOWN_IND */
785 caif_disconnect_client(sock_net(sk), &cf_sk->layer);
786 caif_free_client(&cf_sk->layer);
787 break;
788 }
789 /* No reconnect on a seqpacket socket */
790 err = -EISCONN;
791 goto out;
792 case SS_DISCONNECTING:
793 case SS_FREE:
794 caif_assert(1); /*Should never happen */
795 break;
796 }
797 sk->sk_state = CAIF_DISCONNECTED;
798 sock->state = SS_UNCONNECTED;
799 sk_stream_kill_queues(&cf_sk->sk);
800
801 err = -EINVAL;
802 if (addr_len != sizeof(struct sockaddr_caif))
803 goto out;
804
805 memcpy(&cf_sk->conn_req.sockaddr, uaddr,
806 sizeof(struct sockaddr_caif));
807
808 /* Move to connecting socket, start sending Connect Requests */
809 sock->state = SS_CONNECTING;
810 sk->sk_state = CAIF_CONNECTING;
811
812 /* Check priority value comming from socket */
813 /* if priority value is out of range it will be ajusted */
814 if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX)
815 cf_sk->conn_req.priority = CAIF_PRIO_MAX;
816 else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN)
817 cf_sk->conn_req.priority = CAIF_PRIO_MIN;
818 else
819 cf_sk->conn_req.priority = cf_sk->sk.sk_priority;
820
821 /*ifindex = id of the interface.*/
822 cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if;
823
824 cf_sk->layer.receive = caif_sktrecv_cb;
825
826 err = caif_connect_client(sock_net(sk), &cf_sk->conn_req,
827 &cf_sk->layer, &ifindex, &headroom, &tailroom);
828
829 if (err < 0) {
830 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
831 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
832 goto out;
833 }
834
835 err = -ENODEV;
836 rcu_read_lock();
837 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
838 if (!dev) {
839 rcu_read_unlock();
840 goto out;
841 }
842 cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom);
843 mtu = dev->mtu;
844 rcu_read_unlock();
845
846 cf_sk->tailroom = tailroom;
847 cf_sk->maxframe = mtu - (headroom + tailroom);
848 if (cf_sk->maxframe < 1) {
849 pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu);
850 err = -ENODEV;
851 goto out;
852 }
853
854 err = -EINPROGRESS;
855 wait_connect:
856
857 if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
858 goto out;
859
860 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
861
862 release_sock(sk);
863 err = -ERESTARTSYS;
864 timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
865 sk->sk_state != CAIF_CONNECTING,
866 timeo);
867 lock_sock(sk);
868 if (timeo < 0)
869 goto out; /* -ERESTARTSYS */
870
871 err = -ETIMEDOUT;
872 if (timeo == 0 && sk->sk_state != CAIF_CONNECTED)
873 goto out;
874 if (sk->sk_state != CAIF_CONNECTED) {
875 sock->state = SS_UNCONNECTED;
876 err = sock_error(sk);
877 if (!err)
878 err = -ECONNREFUSED;
879 goto out;
880 }
881 sock->state = SS_CONNECTED;
882 err = 0;
883 out:
884 release_sock(sk);
885 return err;
886 }
887
888 /*
889 * caif_release() - Disconnect a CAIF Socket
890 * Copied and modified af_irda.c:irda_release().
891 */
892 static int caif_release(struct socket *sock)
893 {
894 struct sock *sk = sock->sk;
895 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
896
897 if (!sk)
898 return 0;
899
900 set_tx_flow_off(cf_sk);
901
902 /*
903 * Ensure that packets are not queued after this point in time.
904 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
905 * this ensures no packets when sock is dead.
906 */
907 spin_lock_bh(&sk->sk_receive_queue.lock);
908 sock_set_flag(sk, SOCK_DEAD);
909 spin_unlock_bh(&sk->sk_receive_queue.lock);
910 sock->sk = NULL;
911
912 WARN_ON(IS_ERR(cf_sk->debugfs_socket_dir));
913 if (cf_sk->debugfs_socket_dir != NULL)
914 debugfs_remove_recursive(cf_sk->debugfs_socket_dir);
915
916 lock_sock(&(cf_sk->sk));
917 sk->sk_state = CAIF_DISCONNECTED;
918 sk->sk_shutdown = SHUTDOWN_MASK;
919
920 caif_disconnect_client(sock_net(sk), &cf_sk->layer);
921 cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
922 wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP);
923
924 sock_orphan(sk);
925 sk_stream_kill_queues(&cf_sk->sk);
926 release_sock(sk);
927 sock_put(sk);
928 return 0;
929 }
930
931 /* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */
932 static unsigned int caif_poll(struct file *file,
933 struct socket *sock, poll_table *wait)
934 {
935 struct sock *sk = sock->sk;
936 unsigned int mask;
937 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
938
939 sock_poll_wait(file, sk_sleep(sk), wait);
940 mask = 0;
941
942 /* exceptional events? */
943 if (sk->sk_err)
944 mask |= POLLERR;
945 if (sk->sk_shutdown == SHUTDOWN_MASK)
946 mask |= POLLHUP;
947 if (sk->sk_shutdown & RCV_SHUTDOWN)
948 mask |= POLLRDHUP;
949
950 /* readable? */
951 if (!skb_queue_empty(&sk->sk_receive_queue) ||
952 (sk->sk_shutdown & RCV_SHUTDOWN))
953 mask |= POLLIN | POLLRDNORM;
954
955 /*
956 * we set writable also when the other side has shut down the
957 * connection. This prevents stuck sockets.
958 */
959 if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
960 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
961
962 return mask;
963 }
964
965 static const struct proto_ops caif_seqpacket_ops = {
966 .family = PF_CAIF,
967 .owner = THIS_MODULE,
968 .release = caif_release,
969 .bind = sock_no_bind,
970 .connect = caif_connect,
971 .socketpair = sock_no_socketpair,
972 .accept = sock_no_accept,
973 .getname = sock_no_getname,
974 .poll = caif_poll,
975 .ioctl = sock_no_ioctl,
976 .listen = sock_no_listen,
977 .shutdown = sock_no_shutdown,
978 .setsockopt = setsockopt,
979 .getsockopt = sock_no_getsockopt,
980 .sendmsg = caif_seqpkt_sendmsg,
981 .recvmsg = caif_seqpkt_recvmsg,
982 .mmap = sock_no_mmap,
983 .sendpage = sock_no_sendpage,
984 };
985
986 static const struct proto_ops caif_stream_ops = {
987 .family = PF_CAIF,
988 .owner = THIS_MODULE,
989 .release = caif_release,
990 .bind = sock_no_bind,
991 .connect = caif_connect,
992 .socketpair = sock_no_socketpair,
993 .accept = sock_no_accept,
994 .getname = sock_no_getname,
995 .poll = caif_poll,
996 .ioctl = sock_no_ioctl,
997 .listen = sock_no_listen,
998 .shutdown = sock_no_shutdown,
999 .setsockopt = setsockopt,
1000 .getsockopt = sock_no_getsockopt,
1001 .sendmsg = caif_stream_sendmsg,
1002 .recvmsg = caif_stream_recvmsg,
1003 .mmap = sock_no_mmap,
1004 .sendpage = sock_no_sendpage,
1005 };
1006
1007 /* This function is called when a socket is finally destroyed. */
1008 static void caif_sock_destructor(struct sock *sk)
1009 {
1010 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1011 caif_assert(!atomic_read(&sk->sk_wmem_alloc));
1012 caif_assert(sk_unhashed(sk));
1013 caif_assert(!sk->sk_socket);
1014 if (!sock_flag(sk, SOCK_DEAD)) {
1015 pr_debug("Attempt to release alive CAIF socket: %p\n", sk);
1016 return;
1017 }
1018 sk_stream_kill_queues(&cf_sk->sk);
1019 caif_free_client(&cf_sk->layer);
1020 }
1021
1022 static int caif_create(struct net *net, struct socket *sock, int protocol,
1023 int kern)
1024 {
1025 struct sock *sk = NULL;
1026 struct caifsock *cf_sk = NULL;
1027 static struct proto prot = {.name = "PF_CAIF",
1028 .owner = THIS_MODULE,
1029 .obj_size = sizeof(struct caifsock),
1030 };
1031
1032 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
1033 return -EPERM;
1034 /*
1035 * The sock->type specifies the socket type to use.
1036 * The CAIF socket is a packet stream in the sense
1037 * that it is packet based. CAIF trusts the reliability
1038 * of the link, no resending is implemented.
1039 */
1040 if (sock->type == SOCK_SEQPACKET)
1041 sock->ops = &caif_seqpacket_ops;
1042 else if (sock->type == SOCK_STREAM)
1043 sock->ops = &caif_stream_ops;
1044 else
1045 return -ESOCKTNOSUPPORT;
1046
1047 if (protocol < 0 || protocol >= CAIFPROTO_MAX)
1048 return -EPROTONOSUPPORT;
1049 /*
1050 * Set the socket state to unconnected. The socket state
1051 * is really not used at all in the net/core or socket.c but the
1052 * initialization makes sure that sock->state is not uninitialized.
1053 */
1054 sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot);
1055 if (!sk)
1056 return -ENOMEM;
1057
1058 cf_sk = container_of(sk, struct caifsock, sk);
1059
1060 /* Store the protocol */
1061 sk->sk_protocol = (unsigned char) protocol;
1062
1063 /* Initialize default priority for well-known cases */
1064 switch (protocol) {
1065 case CAIFPROTO_AT:
1066 sk->sk_priority = TC_PRIO_CONTROL;
1067 break;
1068 case CAIFPROTO_RFM:
1069 sk->sk_priority = TC_PRIO_INTERACTIVE_BULK;
1070 break;
1071 default:
1072 sk->sk_priority = TC_PRIO_BESTEFFORT;
1073 }
1074
1075 /*
1076 * Lock in order to try to stop someone from opening the socket
1077 * too early.
1078 */
1079 lock_sock(&(cf_sk->sk));
1080
1081 /* Initialize the nozero default sock structure data. */
1082 sock_init_data(sock, sk);
1083 sk->sk_destruct = caif_sock_destructor;
1084
1085 mutex_init(&cf_sk->readlock); /* single task reading lock */
1086 cf_sk->layer.ctrlcmd = caif_ctrl_cb;
1087 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
1088 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
1089
1090 set_tx_flow_off(cf_sk);
1091 set_rx_flow_on(cf_sk);
1092
1093 /* Set default options on configuration */
1094 cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1095 cf_sk->conn_req.protocol = protocol;
1096 release_sock(&cf_sk->sk);
1097 return 0;
1098 }
1099
1100
1101 static struct net_proto_family caif_family_ops = {
1102 .family = PF_CAIF,
1103 .create = caif_create,
1104 .owner = THIS_MODULE,
1105 };
1106
1107 static int __init caif_sktinit_module(void)
1108 {
1109 int err = sock_register(&caif_family_ops);
1110 if (!err)
1111 return err;
1112 return 0;
1113 }
1114
1115 static void __exit caif_sktexit_module(void)
1116 {
1117 sock_unregister(PF_CAIF);
1118 }
1119 module_init(caif_sktinit_module);
1120 module_exit(caif_sktexit_module);
Linux with added FPC-III support