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