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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) ST-Ericsson AB 2010
4 * Author: Sjur Brendeland
5 */
6
7#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
8
9#include <linux/filter.h>
10#include <linux/fs.h>
11#include <linux/init.h>
12#include <linux/module.h>
13#include <linux/sched/signal.h>
14#include <linux/spinlock.h>
15#include <linux/mutex.h>
16#include <linux/list.h>
17#include <linux/wait.h>
18#include <linux/poll.h>
19#include <linux/tcp.h>
20#include <linux/uaccess.h>
21#include <linux/debugfs.h>
22#include <linux/caif/caif_socket.h>
23#include <linux/pkt_sched.h>
24#include <net/sock.h>
25#include <net/tcp_states.h>
26#include <net/caif/caif_layer.h>
27#include <net/caif/caif_dev.h>
28#include <net/caif/cfpkt.h>
29
30MODULE_LICENSE("GPL");
31MODULE_ALIAS_NETPROTO(AF_CAIF);
32
33/*
34 * CAIF state is re-using the TCP socket states.
35 * caif_states stored in sk_state reflect the state as reported by
36 * the CAIF stack, while sk_socket->state is the state of the socket.
37 */
38enum caif_states {
39 CAIF_CONNECTED = TCP_ESTABLISHED,
40 CAIF_CONNECTING = TCP_SYN_SENT,
41 CAIF_DISCONNECTED = TCP_CLOSE
42};
43
44#define TX_FLOW_ON_BIT 1
45#define RX_FLOW_ON_BIT 2
46
47struct caifsock {
48 struct sock sk; /* must be first member */
49 struct cflayer layer;
50 unsigned long flow_state;
51 struct caif_connect_request conn_req;
52 struct mutex readlock;
53 struct dentry *debugfs_socket_dir;
54 int headroom, tailroom, maxframe;
55};
56
57static int rx_flow_is_on(struct caifsock *cf_sk)
58{
59 return test_bit(RX_FLOW_ON_BIT, &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, &cf_sk->flow_state);
65}
66
67static void set_rx_flow_off(struct caifsock *cf_sk)
68{
69 clear_bit(RX_FLOW_ON_BIT, &cf_sk->flow_state);
70}
71
72static void set_rx_flow_on(struct caifsock *cf_sk)
73{
74 set_bit(RX_FLOW_ON_BIT, &cf_sk->flow_state);
75}
76
77static void set_tx_flow_off(struct caifsock *cf_sk)
78{
79 clear_bit(TX_FLOW_ON_BIT, &cf_sk->flow_state);
80}
81
82static void set_tx_flow_on(struct caifsock *cf_sk)
83{
84 set_bit(TX_FLOW_ON_BIT, &cf_sk->flow_state);
85}
86
87static void caif_read_lock(struct sock *sk)
88{
89 struct caifsock *cf_sk;
90 cf_sk = container_of(sk, struct caifsock, sk);
91 mutex_lock(&cf_sk->readlock);
92}
93
94static void caif_read_unlock(struct sock *sk)
95{
96 struct caifsock *cf_sk;
97 cf_sk = container_of(sk, struct caifsock, sk);
98 mutex_unlock(&cf_sk->readlock);
99}
100
101static int sk_rcvbuf_lowwater(struct caifsock *cf_sk)
102{
103 /* A quarter of full buffer is used a low water mark */
104 return cf_sk->sk.sk_rcvbuf / 4;
105}
106
107static void caif_flow_ctrl(struct sock *sk, int mode)
108{
109 struct caifsock *cf_sk;
110 cf_sk = container_of(sk, struct caifsock, sk);
111 if (cf_sk->layer.dn && cf_sk->layer.dn->modemcmd)
112 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, mode);
113}
114
115/*
116 * Copied from sock.c:sock_queue_rcv_skb(), but changed so packets are
117 * not dropped, but CAIF is sending flow off instead.
118 */
119static void caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
120{
121 int err;
122 unsigned long flags;
123 struct sk_buff_head *list = &sk->sk_receive_queue;
124 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
125 bool queued = false;
126
127 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
128 (unsigned int)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) {
129 net_dbg_ratelimited("sending flow OFF (queue len = %d %d)\n",
130 atomic_read(&cf_sk->sk.sk_rmem_alloc),
131 sk_rcvbuf_lowwater(cf_sk));
132 set_rx_flow_off(cf_sk);
133 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
134 }
135
136 err = sk_filter(sk, skb);
137 if (err)
138 goto out;
139
140 if (!sk_rmem_schedule(sk, skb, skb->truesize) && rx_flow_is_on(cf_sk)) {
141 set_rx_flow_off(cf_sk);
142 net_dbg_ratelimited("sending flow OFF due to rmem_schedule\n");
143 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
144 }
145 skb->dev = NULL;
146 skb_set_owner_r(skb, sk);
147 spin_lock_irqsave(&list->lock, flags);
148 queued = !sock_flag(sk, SOCK_DEAD);
149 if (queued)
150 __skb_queue_tail(list, skb);
151 spin_unlock_irqrestore(&list->lock, flags);
152out:
153 if (queued)
154 sk->sk_data_ready(sk);
155 else
156 kfree_skb(skb);
157}
158
159/* Packet Receive Callback function called from CAIF Stack */
160static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
161{
162 struct caifsock *cf_sk;
163 struct sk_buff *skb;
164
165 cf_sk = container_of(layr, struct caifsock, layer);
166 skb = cfpkt_tonative(pkt);
167
168 if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) {
169 kfree_skb(skb);
170 return 0;
171 }
172 caif_queue_rcv_skb(&cf_sk->sk, skb);
173 return 0;
174}
175
176static void cfsk_hold(struct cflayer *layr)
177{
178 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
179 sock_hold(&cf_sk->sk);
180}
181
182static void cfsk_put(struct cflayer *layr)
183{
184 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
185 sock_put(&cf_sk->sk);
186}
187
188/* Packet Control Callback function called from CAIF */
189static void caif_ctrl_cb(struct cflayer *layr,
190 enum caif_ctrlcmd flow,
191 int phyid)
192{
193 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
194 switch (flow) {
195 case CAIF_CTRLCMD_FLOW_ON_IND:
196 /* OK from modem to start sending again */
197 set_tx_flow_on(cf_sk);
198 cf_sk->sk.sk_state_change(&cf_sk->sk);
199 break;
200
201 case CAIF_CTRLCMD_FLOW_OFF_IND:
202 /* Modem asks us to shut up */
203 set_tx_flow_off(cf_sk);
204 cf_sk->sk.sk_state_change(&cf_sk->sk);
205 break;
206
207 case CAIF_CTRLCMD_INIT_RSP:
208 /* We're now connected */
209 caif_client_register_refcnt(&cf_sk->layer,
210 cfsk_hold, cfsk_put);
211 cf_sk->sk.sk_state = CAIF_CONNECTED;
212 set_tx_flow_on(cf_sk);
213 cf_sk->sk.sk_shutdown = 0;
214 cf_sk->sk.sk_state_change(&cf_sk->sk);
215 break;
216
217 case CAIF_CTRLCMD_DEINIT_RSP:
218 /* We're now disconnected */
219 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
220 cf_sk->sk.sk_state_change(&cf_sk->sk);
221 break;
222
223 case CAIF_CTRLCMD_INIT_FAIL_RSP:
224 /* Connect request failed */
225 cf_sk->sk.sk_err = ECONNREFUSED;
226 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
227 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
228 /*
229 * Socket "standards" seems to require POLLOUT to
230 * be set at connect failure.
231 */
232 set_tx_flow_on(cf_sk);
233 cf_sk->sk.sk_state_change(&cf_sk->sk);
234 break;
235
236 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
237 /* Modem has closed this connection, or device is down. */
238 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
239 cf_sk->sk.sk_err = ECONNRESET;
240 set_rx_flow_on(cf_sk);
241 sk_error_report(&cf_sk->sk);
242 break;
243
244 default:
245 pr_debug("Unexpected flow command %d\n", flow);
246 }
247}
248
249static void caif_check_flow_release(struct sock *sk)
250{
251 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
252
253 if (rx_flow_is_on(cf_sk))
254 return;
255
256 if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) {
257 set_rx_flow_on(cf_sk);
258 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ);
259 }
260}
261
262/*
263 * Copied from unix_dgram_recvmsg, but removed credit checks,
264 * changed locking, address handling and added MSG_TRUNC.
265 */
266static int caif_seqpkt_recvmsg(struct socket *sock, struct msghdr *m,
267 size_t len, int flags)
268
269{
270 struct sock *sk = sock->sk;
271 struct sk_buff *skb;
272 int ret;
273 int copylen;
274
275 ret = -EOPNOTSUPP;
276 if (flags & MSG_OOB)
277 goto read_error;
278
279 skb = skb_recv_datagram(sk, flags, &ret);
280 if (!skb)
281 goto read_error;
282 copylen = skb->len;
283 if (len < copylen) {
284 m->msg_flags |= MSG_TRUNC;
285 copylen = len;
286 }
287
288 ret = skb_copy_datagram_msg(skb, 0, m, copylen);
289 if (ret)
290 goto out_free;
291
292 ret = (flags & MSG_TRUNC) ? skb->len : copylen;
293out_free:
294 skb_free_datagram(sk, skb);
295 caif_check_flow_release(sk);
296 return ret;
297
298read_error:
299 return ret;
300}
301
302
303/* Copied from unix_stream_wait_data, identical except for lock call. */
304static long caif_stream_data_wait(struct sock *sk, long timeo)
305{
306 DEFINE_WAIT(wait);
307 lock_sock(sk);
308
309 for (;;) {
310 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
311
312 if (!skb_queue_empty(&sk->sk_receive_queue) ||
313 sk->sk_err ||
314 sk->sk_state != CAIF_CONNECTED ||
315 sock_flag(sk, SOCK_DEAD) ||
316 (sk->sk_shutdown & RCV_SHUTDOWN) ||
317 signal_pending(current) ||
318 !timeo)
319 break;
320
321 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
322 release_sock(sk);
323 timeo = schedule_timeout(timeo);
324 lock_sock(sk);
325
326 if (sock_flag(sk, SOCK_DEAD))
327 break;
328
329 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
330 }
331
332 finish_wait(sk_sleep(sk), &wait);
333 release_sock(sk);
334 return timeo;
335}
336
337
338/*
339 * Copied from unix_stream_recvmsg, but removed credit checks,
340 * changed locking calls, changed address handling.
341 */
342static int caif_stream_recvmsg(struct socket *sock, struct msghdr *msg,
343 size_t size, int flags)
344{
345 struct sock *sk = sock->sk;
346 int copied = 0;
347 int target;
348 int err = 0;
349 long timeo;
350
351 err = -EOPNOTSUPP;
352 if (flags&MSG_OOB)
353 goto out;
354
355 /*
356 * Lock the socket to prevent queue disordering
357 * while sleeps in memcpy_tomsg
358 */
359 err = -EAGAIN;
360 if (sk->sk_state == CAIF_CONNECTING)
361 goto out;
362
363 caif_read_lock(sk);
364 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
365 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
366
367 do {
368 int chunk;
369 struct sk_buff *skb;
370
371 lock_sock(sk);
372 if (sock_flag(sk, SOCK_DEAD)) {
373 err = -ECONNRESET;
374 goto unlock;
375 }
376 skb = skb_dequeue(&sk->sk_receive_queue);
377 caif_check_flow_release(sk);
378
379 if (skb == NULL) {
380 if (copied >= target)
381 goto unlock;
382 /*
383 * POSIX 1003.1g mandates this order.
384 */
385 err = sock_error(sk);
386 if (err)
387 goto unlock;
388 err = -ECONNRESET;
389 if (sk->sk_shutdown & RCV_SHUTDOWN)
390 goto unlock;
391
392 err = -EPIPE;
393 if (sk->sk_state != CAIF_CONNECTED)
394 goto unlock;
395 if (sock_flag(sk, SOCK_DEAD))
396 goto unlock;
397
398 release_sock(sk);
399
400 err = -EAGAIN;
401 if (!timeo)
402 break;
403
404 caif_read_unlock(sk);
405
406 timeo = caif_stream_data_wait(sk, timeo);
407
408 if (signal_pending(current)) {
409 err = sock_intr_errno(timeo);
410 goto out;
411 }
412 caif_read_lock(sk);
413 continue;
414unlock:
415 release_sock(sk);
416 break;
417 }
418 release_sock(sk);
419 chunk = min_t(unsigned int, skb->len, size);
420 if (memcpy_to_msg(msg, skb->data, chunk)) {
421 skb_queue_head(&sk->sk_receive_queue, skb);
422 if (copied == 0)
423 copied = -EFAULT;
424 break;
425 }
426 copied += chunk;
427 size -= chunk;
428
429 /* Mark read part of skb as used */
430 if (!(flags & MSG_PEEK)) {
431 skb_pull(skb, chunk);
432
433 /* put the skb back if we didn't use it up. */
434 if (skb->len) {
435 skb_queue_head(&sk->sk_receive_queue, skb);
436 break;
437 }
438 kfree_skb(skb);
439
440 } else {
441 /*
442 * It is questionable, see note in unix_dgram_recvmsg.
443 */
444 /* put message back and return */
445 skb_queue_head(&sk->sk_receive_queue, skb);
446 break;
447 }
448 } while (size);
449 caif_read_unlock(sk);
450
451out:
452 return copied ? : err;
453}
454
455/*
456 * Copied from sock.c:sock_wait_for_wmem, but change to wait for
457 * CAIF flow-on and sock_writable.
458 */
459static long caif_wait_for_flow_on(struct caifsock *cf_sk,
460 int wait_writeable, long timeo, int *err)
461{
462 struct sock *sk = &cf_sk->sk;
463 DEFINE_WAIT(wait);
464 for (;;) {
465 *err = 0;
466 if (tx_flow_is_on(cf_sk) &&
467 (!wait_writeable || sock_writeable(&cf_sk->sk)))
468 break;
469 *err = -ETIMEDOUT;
470 if (!timeo)
471 break;
472 *err = -ERESTARTSYS;
473 if (signal_pending(current))
474 break;
475 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
476 *err = -ECONNRESET;
477 if (sk->sk_shutdown & SHUTDOWN_MASK)
478 break;
479 *err = -sk->sk_err;
480 if (sk->sk_err)
481 break;
482 *err = -EPIPE;
483 if (cf_sk->sk.sk_state != CAIF_CONNECTED)
484 break;
485 timeo = schedule_timeout(timeo);
486 }
487 finish_wait(sk_sleep(sk), &wait);
488 return timeo;
489}
490
491/*
492 * Transmit a SKB. The device may temporarily request re-transmission
493 * by returning EAGAIN.
494 */
495static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk,
496 int noblock, long timeo)
497{
498 struct cfpkt *pkt;
499
500 pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb);
501 memset(skb->cb, 0, sizeof(struct caif_payload_info));
502 cfpkt_set_prio(pkt, cf_sk->sk.sk_priority);
503
504 if (cf_sk->layer.dn == NULL) {
505 kfree_skb(skb);
506 return -EINVAL;
507 }
508
509 return cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
510}
511
512/* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
513static int caif_seqpkt_sendmsg(struct socket *sock, struct msghdr *msg,
514 size_t len)
515{
516 struct sock *sk = sock->sk;
517 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
518 int buffer_size;
519 int ret = 0;
520 struct sk_buff *skb = NULL;
521 int noblock;
522 long timeo;
523 caif_assert(cf_sk);
524 ret = sock_error(sk);
525 if (ret)
526 goto err;
527
528 ret = -EOPNOTSUPP;
529 if (msg->msg_flags&MSG_OOB)
530 goto err;
531
532 ret = -EOPNOTSUPP;
533 if (msg->msg_namelen)
534 goto err;
535
536 ret = -EINVAL;
537 if (unlikely(msg->msg_iter.nr_segs == 0) ||
538 unlikely(msg->msg_iter.iov->iov_base == NULL))
539 goto err;
540 noblock = msg->msg_flags & MSG_DONTWAIT;
541
542 timeo = sock_sndtimeo(sk, noblock);
543 timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
544 1, timeo, &ret);
545
546 if (ret)
547 goto err;
548 ret = -EPIPE;
549 if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
550 sock_flag(sk, SOCK_DEAD) ||
551 (sk->sk_shutdown & RCV_SHUTDOWN))
552 goto err;
553
554 /* Error if trying to write more than maximum frame size. */
555 ret = -EMSGSIZE;
556 if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM)
557 goto err;
558
559 buffer_size = len + cf_sk->headroom + cf_sk->tailroom;
560
561 ret = -ENOMEM;
562 skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
563
564 if (!skb || skb_tailroom(skb) < buffer_size)
565 goto err;
566
567 skb_reserve(skb, cf_sk->headroom);
568
569 ret = memcpy_from_msg(skb_put(skb, len), msg, len);
570
571 if (ret)
572 goto err;
573 ret = transmit_skb(skb, cf_sk, noblock, timeo);
574 if (ret < 0)
575 /* skb is already freed */
576 return ret;
577
578 return len;
579err:
580 kfree_skb(skb);
581 return ret;
582}
583
584/*
585 * Copied from unix_stream_sendmsg and adapted to CAIF:
586 * Changed removed permission handling and added waiting for flow on
587 * and other minor adaptations.
588 */
589static int caif_stream_sendmsg(struct socket *sock, struct msghdr *msg,
590 size_t len)
591{
592 struct sock *sk = sock->sk;
593 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
594 int err, size;
595 struct sk_buff *skb;
596 int sent = 0;
597 long timeo;
598
599 err = -EOPNOTSUPP;
600 if (unlikely(msg->msg_flags&MSG_OOB))
601 goto out_err;
602
603 if (unlikely(msg->msg_namelen))
604 goto out_err;
605
606 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
607 timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
608
609 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
610 goto pipe_err;
611
612 while (sent < len) {
613
614 size = len-sent;
615
616 if (size > cf_sk->maxframe)
617 size = cf_sk->maxframe;
618
619 /* If size is more than half of sndbuf, chop up message */
620 if (size > ((sk->sk_sndbuf >> 1) - 64))
621 size = (sk->sk_sndbuf >> 1) - 64;
622
623 if (size > SKB_MAX_ALLOC)
624 size = SKB_MAX_ALLOC;
625
626 skb = sock_alloc_send_skb(sk,
627 size + cf_sk->headroom +
628 cf_sk->tailroom,
629 msg->msg_flags&MSG_DONTWAIT,
630 &err);
631 if (skb == NULL)
632 goto out_err;
633
634 skb_reserve(skb, cf_sk->headroom);
635 /*
636 * If you pass two values to the sock_alloc_send_skb
637 * it tries to grab the large buffer with GFP_NOFS
638 * (which can fail easily), and if it fails grab the
639 * fallback size buffer which is under a page and will
640 * succeed. [Alan]
641 */
642 size = min_t(int, size, skb_tailroom(skb));
643
644 err = memcpy_from_msg(skb_put(skb, size), msg, size);
645 if (err) {
646 kfree_skb(skb);
647 goto out_err;
648 }
649 err = transmit_skb(skb, cf_sk,
650 msg->msg_flags&MSG_DONTWAIT, timeo);
651 if (err < 0)
652 /* skb is already freed */
653 goto pipe_err;
654
655 sent += size;
656 }
657
658 return sent;
659
660pipe_err:
661 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
662 send_sig(SIGPIPE, current, 0);
663 err = -EPIPE;
664out_err:
665 return sent ? : err;
666}
667
668static int setsockopt(struct socket *sock, int lvl, int opt, sockptr_t ov,
669 unsigned int ol)
670{
671 struct sock *sk = sock->sk;
672 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
673 int linksel;
674
675 if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
676 return -ENOPROTOOPT;
677
678 switch (opt) {
679 case CAIFSO_LINK_SELECT:
680 if (ol < sizeof(int))
681 return -EINVAL;
682 if (lvl != SOL_CAIF)
683 goto bad_sol;
684 if (copy_from_sockptr(&linksel, ov, sizeof(int)))
685 return -EINVAL;
686 lock_sock(&(cf_sk->sk));
687 cf_sk->conn_req.link_selector = linksel;
688 release_sock(&cf_sk->sk);
689 return 0;
690
691 case CAIFSO_REQ_PARAM:
692 if (lvl != SOL_CAIF)
693 goto bad_sol;
694 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
695 return -ENOPROTOOPT;
696 lock_sock(&(cf_sk->sk));
697 if (ol > sizeof(cf_sk->conn_req.param.data) ||
698 copy_from_sockptr(&cf_sk->conn_req.param.data, ov, ol)) {
699 release_sock(&cf_sk->sk);
700 return -EINVAL;
701 }
702 cf_sk->conn_req.param.size = ol;
703 release_sock(&cf_sk->sk);
704 return 0;
705
706 default:
707 return -ENOPROTOOPT;
708 }
709
710 return 0;
711bad_sol:
712 return -ENOPROTOOPT;
713
714}
715
716/*
717 * caif_connect() - Connect a CAIF Socket
718 * Copied and modified af_irda.c:irda_connect().
719 *
720 * Note : by consulting "errno", the user space caller may learn the cause
721 * of the failure. Most of them are visible in the function, others may come
722 * from subroutines called and are listed here :
723 * o -EAFNOSUPPORT: bad socket family or type.
724 * o -ESOCKTNOSUPPORT: bad socket type or protocol
725 * o -EINVAL: bad socket address, or CAIF link type
726 * o -ECONNREFUSED: remote end refused the connection.
727 * o -EINPROGRESS: connect request sent but timed out (or non-blocking)
728 * o -EISCONN: already connected.
729 * o -ETIMEDOUT: Connection timed out (send timeout)
730 * o -ENODEV: No link layer to send request
731 * o -ECONNRESET: Received Shutdown indication or lost link layer
732 * o -ENOMEM: Out of memory
733 *
734 * State Strategy:
735 * o sk_state: holds the CAIF_* protocol state, it's updated by
736 * caif_ctrl_cb.
737 * o sock->state: holds the SS_* socket state and is updated by connect and
738 * disconnect.
739 */
740static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
741 int addr_len, int flags)
742{
743 struct sock *sk = sock->sk;
744 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
745 long timeo;
746 int err;
747 int ifindex, headroom, tailroom;
748 unsigned int mtu;
749 struct net_device *dev;
750
751 lock_sock(sk);
752
753 err = -EINVAL;
754 if (addr_len < offsetofend(struct sockaddr, sa_family))
755 goto out;
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), EPOLLERR|EPOLLHUP);
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 __poll_t caif_poll(struct file *file,
934 struct socket *sock, poll_table *wait)
935{
936 struct sock *sk = sock->sk;
937 __poll_t mask;
938 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
939
940 sock_poll_wait(file, sock, wait);
941 mask = 0;
942
943 /* exceptional events? */
944 if (sk->sk_err)
945 mask |= EPOLLERR;
946 if (sk->sk_shutdown == SHUTDOWN_MASK)
947 mask |= EPOLLHUP;
948 if (sk->sk_shutdown & RCV_SHUTDOWN)
949 mask |= EPOLLRDHUP;
950
951 /* readable? */
952 if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
953 (sk->sk_shutdown & RCV_SHUTDOWN))
954 mask |= EPOLLIN | EPOLLRDNORM;
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 |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
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 .sendmsg = caif_seqpkt_sendmsg,
981 .recvmsg = caif_seqpkt_recvmsg,
982 .mmap = sock_no_mmap,
983 .sendpage = sock_no_sendpage,
984};
985
986static const struct proto_ops caif_stream_ops = {
987 .family = PF_CAIF,
988 .owner = THIS_MODULE,
989 .release = caif_release,
990 .bind = sock_no_bind,
991 .connect = caif_connect,
992 .socketpair = sock_no_socketpair,
993 .accept = sock_no_accept,
994 .getname = sock_no_getname,
995 .poll = caif_poll,
996 .ioctl = sock_no_ioctl,
997 .listen = sock_no_listen,
998 .shutdown = sock_no_shutdown,
999 .setsockopt = setsockopt,
1000 .sendmsg = caif_stream_sendmsg,
1001 .recvmsg = caif_stream_recvmsg,
1002 .mmap = sock_no_mmap,
1003 .sendpage = sock_no_sendpage,
1004};
1005
1006/* This function is called when a socket is finally destroyed. */
1007static void caif_sock_destructor(struct sock *sk)
1008{
1009 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1010 caif_assert(!refcount_read(&sk->sk_wmem_alloc));
1011 caif_assert(sk_unhashed(sk));
1012 caif_assert(!sk->sk_socket);
1013 if (!sock_flag(sk, SOCK_DEAD)) {
1014 pr_debug("Attempt to release alive CAIF socket: %p\n", sk);
1015 return;
1016 }
1017 sk_stream_kill_queues(&cf_sk->sk);
1018 WARN_ON_ONCE(sk->sk_forward_alloc);
1019 caif_free_client(&cf_sk->layer);
1020}
1021
1022static int caif_create(struct net *net, struct socket *sock, int protocol,
1023 int kern)
1024{
1025 struct sock *sk = NULL;
1026 struct caifsock *cf_sk = NULL;
1027 static struct proto prot = {.name = "PF_CAIF",
1028 .owner = THIS_MODULE,
1029 .obj_size = sizeof(struct caifsock),
1030 .useroffset = offsetof(struct caifsock, conn_req.param),
1031 .usersize = sizeof_field(struct caifsock, conn_req.param)
1032 };
1033
1034 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
1035 return -EPERM;
1036 /*
1037 * The sock->type specifies the socket type to use.
1038 * The CAIF socket is a packet stream in the sense
1039 * that it is packet based. CAIF trusts the reliability
1040 * of the link, no resending is implemented.
1041 */
1042 if (sock->type == SOCK_SEQPACKET)
1043 sock->ops = &caif_seqpacket_ops;
1044 else if (sock->type == SOCK_STREAM)
1045 sock->ops = &caif_stream_ops;
1046 else
1047 return -ESOCKTNOSUPPORT;
1048
1049 if (protocol < 0 || protocol >= CAIFPROTO_MAX)
1050 return -EPROTONOSUPPORT;
1051 /*
1052 * Set the socket state to unconnected. The socket state
1053 * is really not used at all in the net/core or socket.c but the
1054 * initialization makes sure that sock->state is not uninitialized.
1055 */
1056 sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot, kern);
1057 if (!sk)
1058 return -ENOMEM;
1059
1060 cf_sk = container_of(sk, struct caifsock, sk);
1061
1062 /* Store the protocol */
1063 sk->sk_protocol = (unsigned char) protocol;
1064
1065 /* Initialize default priority for well-known cases */
1066 switch (protocol) {
1067 case CAIFPROTO_AT:
1068 sk->sk_priority = TC_PRIO_CONTROL;
1069 break;
1070 case CAIFPROTO_RFM:
1071 sk->sk_priority = TC_PRIO_INTERACTIVE_BULK;
1072 break;
1073 default:
1074 sk->sk_priority = TC_PRIO_BESTEFFORT;
1075 }
1076
1077 /*
1078 * Lock in order to try to stop someone from opening the socket
1079 * too early.
1080 */
1081 lock_sock(&(cf_sk->sk));
1082
1083 /* Initialize the nozero default sock structure data. */
1084 sock_init_data(sock, sk);
1085 sk->sk_destruct = caif_sock_destructor;
1086
1087 mutex_init(&cf_sk->readlock); /* single task reading lock */
1088 cf_sk->layer.ctrlcmd = caif_ctrl_cb;
1089 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
1090 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
1091
1092 set_tx_flow_off(cf_sk);
1093 set_rx_flow_on(cf_sk);
1094
1095 /* Set default options on configuration */
1096 cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1097 cf_sk->conn_req.protocol = protocol;
1098 release_sock(&cf_sk->sk);
1099 return 0;
1100}
1101
1102
1103static const struct net_proto_family caif_family_ops = {
1104 .family = PF_CAIF,
1105 .create = caif_create,
1106 .owner = THIS_MODULE,
1107};
1108
1109static int __init caif_sktinit_module(void)
1110{
1111 return sock_register(&caif_family_ops);
1112}
1113
1114static void __exit caif_sktexit_module(void)
1115{
1116 sock_unregister(PF_CAIF);
1117}
1118module_init(caif_sktinit_module);
1119module_exit(caif_sktexit_module);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) ST-Ericsson AB 2010
4 * Author: Sjur Brendeland
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/signal.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, int lvl, int opt, sockptr_t ov,
673 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_sockptr(&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_sockptr(&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 = -EINVAL;
758 if (addr_len < offsetofend(struct sockaddr, sa_family))
759 goto out;
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;
861wait_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;
889out:
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 */
898static 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), EPOLLERR|EPOLLHUP);
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 */
937static __poll_t caif_poll(struct file *file,
938 struct socket *sock, poll_table *wait)
939{
940 struct sock *sk = sock->sk;
941 __poll_t mask;
942 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
943
944 sock_poll_wait(file, sock, wait);
945 mask = 0;
946
947 /* exceptional events? */
948 if (sk->sk_err)
949 mask |= EPOLLERR;
950 if (sk->sk_shutdown == SHUTDOWN_MASK)
951 mask |= EPOLLHUP;
952 if (sk->sk_shutdown & RCV_SHUTDOWN)
953 mask |= EPOLLRDHUP;
954
955 /* readable? */
956 if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
957 (sk->sk_shutdown & RCV_SHUTDOWN))
958 mask |= EPOLLIN | EPOLLRDNORM;
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 |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
966
967 return mask;
968}
969
970static 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 .sendmsg = caif_seqpkt_sendmsg,
985 .recvmsg = caif_seqpkt_recvmsg,
986 .mmap = sock_no_mmap,
987 .sendpage = sock_no_sendpage,
988};
989
990static const struct proto_ops caif_stream_ops = {
991 .family = PF_CAIF,
992 .owner = THIS_MODULE,
993 .release = caif_release,
994 .bind = sock_no_bind,
995 .connect = caif_connect,
996 .socketpair = sock_no_socketpair,
997 .accept = sock_no_accept,
998 .getname = sock_no_getname,
999 .poll = caif_poll,
1000 .ioctl = sock_no_ioctl,
1001 .listen = sock_no_listen,
1002 .shutdown = sock_no_shutdown,
1003 .setsockopt = setsockopt,
1004 .sendmsg = caif_stream_sendmsg,
1005 .recvmsg = caif_stream_recvmsg,
1006 .mmap = sock_no_mmap,
1007 .sendpage = sock_no_sendpage,
1008};
1009
1010/* This function is called when a socket is finally destroyed. */
1011static void caif_sock_destructor(struct sock *sk)
1012{
1013 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1014 caif_assert(!refcount_read(&sk->sk_wmem_alloc));
1015 caif_assert(sk_unhashed(sk));
1016 caif_assert(!sk->sk_socket);
1017 if (!sock_flag(sk, SOCK_DEAD)) {
1018 pr_debug("Attempt to release alive CAIF socket: %p\n", sk);
1019 return;
1020 }
1021 sk_stream_kill_queues(&cf_sk->sk);
1022 caif_free_client(&cf_sk->layer);
1023}
1024
1025static int caif_create(struct net *net, struct socket *sock, int protocol,
1026 int kern)
1027{
1028 struct sock *sk = NULL;
1029 struct caifsock *cf_sk = NULL;
1030 static struct proto prot = {.name = "PF_CAIF",
1031 .owner = THIS_MODULE,
1032 .obj_size = sizeof(struct caifsock),
1033 .useroffset = offsetof(struct caifsock, conn_req.param),
1034 .usersize = sizeof_field(struct caifsock, conn_req.param)
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, kern);
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
1106static const struct net_proto_family caif_family_ops = {
1107 .family = PF_CAIF,
1108 .create = caif_create,
1109 .owner = THIS_MODULE,
1110};
1111
1112static int __init caif_sktinit_module(void)
1113{
1114 return sock_register(&caif_family_ops);
1115}
1116
1117static void __exit caif_sktexit_module(void)
1118{
1119 sock_unregister(PF_CAIF);
1120}
1121module_init(caif_sktinit_module);
1122module_exit(caif_sktexit_module);