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