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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);
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_DESCRIPTION("ST-Ericsson CAIF modem protocol socket support (AF_CAIF)");
31MODULE_LICENSE("GPL");
32MODULE_ALIAS_NETPROTO(AF_CAIF);
33
34/*
35 * CAIF state is re-using the TCP socket states.
36 * caif_states stored in sk_state reflect the state as reported by
37 * the CAIF stack, while sk_socket->state is the state of the socket.
38 */
39enum caif_states {
40 CAIF_CONNECTED = TCP_ESTABLISHED,
41 CAIF_CONNECTING = TCP_SYN_SENT,
42 CAIF_DISCONNECTED = TCP_CLOSE
43};
44
45#define TX_FLOW_ON_BIT 1
46#define RX_FLOW_ON_BIT 2
47
48struct caifsock {
49 struct sock sk; /* must be first member */
50 struct cflayer layer;
51 unsigned long flow_state;
52 struct caif_connect_request conn_req;
53 struct mutex readlock;
54 struct dentry *debugfs_socket_dir;
55 int headroom, tailroom, maxframe;
56};
57
58static int rx_flow_is_on(struct caifsock *cf_sk)
59{
60 return test_bit(RX_FLOW_ON_BIT, &cf_sk->flow_state);
61}
62
63static int tx_flow_is_on(struct caifsock *cf_sk)
64{
65 return test_bit(TX_FLOW_ON_BIT, &cf_sk->flow_state);
66}
67
68static void set_rx_flow_off(struct caifsock *cf_sk)
69{
70 clear_bit(RX_FLOW_ON_BIT, &cf_sk->flow_state);
71}
72
73static void set_rx_flow_on(struct caifsock *cf_sk)
74{
75 set_bit(RX_FLOW_ON_BIT, &cf_sk->flow_state);
76}
77
78static void set_tx_flow_off(struct caifsock *cf_sk)
79{
80 clear_bit(TX_FLOW_ON_BIT, &cf_sk->flow_state);
81}
82
83static void set_tx_flow_on(struct caifsock *cf_sk)
84{
85 set_bit(TX_FLOW_ON_BIT, &cf_sk->flow_state);
86}
87
88static void caif_read_lock(struct sock *sk)
89{
90 struct caifsock *cf_sk;
91 cf_sk = container_of(sk, struct caifsock, sk);
92 mutex_lock(&cf_sk->readlock);
93}
94
95static void caif_read_unlock(struct sock *sk)
96{
97 struct caifsock *cf_sk;
98 cf_sk = container_of(sk, struct caifsock, sk);
99 mutex_unlock(&cf_sk->readlock);
100}
101
102static int sk_rcvbuf_lowwater(struct caifsock *cf_sk)
103{
104 /* A quarter of full buffer is used a low water mark */
105 return cf_sk->sk.sk_rcvbuf / 4;
106}
107
108static void caif_flow_ctrl(struct sock *sk, int mode)
109{
110 struct caifsock *cf_sk;
111 cf_sk = container_of(sk, struct caifsock, sk);
112 if (cf_sk->layer.dn && cf_sk->layer.dn->modemcmd)
113 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, mode);
114}
115
116/*
117 * Copied from sock.c:sock_queue_rcv_skb(), but changed so packets are
118 * not dropped, but CAIF is sending flow off instead.
119 */
120static void caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
121{
122 int err;
123 unsigned long flags;
124 struct sk_buff_head *list = &sk->sk_receive_queue;
125 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
126 bool queued = false;
127
128 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
129 (unsigned int)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) {
130 net_dbg_ratelimited("sending flow OFF (queue len = %d %d)\n",
131 atomic_read(&cf_sk->sk.sk_rmem_alloc),
132 sk_rcvbuf_lowwater(cf_sk));
133 set_rx_flow_off(cf_sk);
134 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
135 }
136
137 err = sk_filter(sk, skb);
138 if (err)
139 goto out;
140
141 if (!sk_rmem_schedule(sk, skb, skb->truesize) && rx_flow_is_on(cf_sk)) {
142 set_rx_flow_off(cf_sk);
143 net_dbg_ratelimited("sending flow OFF due to rmem_schedule\n");
144 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
145 }
146 skb->dev = NULL;
147 skb_set_owner_r(skb, sk);
148 spin_lock_irqsave(&list->lock, flags);
149 queued = !sock_flag(sk, SOCK_DEAD);
150 if (queued)
151 __skb_queue_tail(list, skb);
152 spin_unlock_irqrestore(&list->lock, flags);
153out:
154 if (queued)
155 sk->sk_data_ready(sk);
156 else
157 kfree_skb(skb);
158}
159
160/* Packet Receive Callback function called from CAIF Stack */
161static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
162{
163 struct caifsock *cf_sk;
164 struct sk_buff *skb;
165
166 cf_sk = container_of(layr, struct caifsock, layer);
167 skb = cfpkt_tonative(pkt);
168
169 if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) {
170 kfree_skb(skb);
171 return 0;
172 }
173 caif_queue_rcv_skb(&cf_sk->sk, skb);
174 return 0;
175}
176
177static void cfsk_hold(struct cflayer *layr)
178{
179 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
180 sock_hold(&cf_sk->sk);
181}
182
183static void cfsk_put(struct cflayer *layr)
184{
185 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
186 sock_put(&cf_sk->sk);
187}
188
189/* Packet Control Callback function called from CAIF */
190static void caif_ctrl_cb(struct cflayer *layr,
191 enum caif_ctrlcmd flow,
192 int phyid)
193{
194 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
195 switch (flow) {
196 case CAIF_CTRLCMD_FLOW_ON_IND:
197 /* OK from modem to start sending again */
198 set_tx_flow_on(cf_sk);
199 cf_sk->sk.sk_state_change(&cf_sk->sk);
200 break;
201
202 case CAIF_CTRLCMD_FLOW_OFF_IND:
203 /* Modem asks us to shut up */
204 set_tx_flow_off(cf_sk);
205 cf_sk->sk.sk_state_change(&cf_sk->sk);
206 break;
207
208 case CAIF_CTRLCMD_INIT_RSP:
209 /* We're now connected */
210 caif_client_register_refcnt(&cf_sk->layer,
211 cfsk_hold, cfsk_put);
212 cf_sk->sk.sk_state = CAIF_CONNECTED;
213 set_tx_flow_on(cf_sk);
214 cf_sk->sk.sk_shutdown = 0;
215 cf_sk->sk.sk_state_change(&cf_sk->sk);
216 break;
217
218 case CAIF_CTRLCMD_DEINIT_RSP:
219 /* We're now disconnected */
220 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
221 cf_sk->sk.sk_state_change(&cf_sk->sk);
222 break;
223
224 case CAIF_CTRLCMD_INIT_FAIL_RSP:
225 /* Connect request failed */
226 cf_sk->sk.sk_err = ECONNREFUSED;
227 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
228 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
229 /*
230 * Socket "standards" seems to require POLLOUT to
231 * be set at connect failure.
232 */
233 set_tx_flow_on(cf_sk);
234 cf_sk->sk.sk_state_change(&cf_sk->sk);
235 break;
236
237 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
238 /* Modem has closed this connection, or device is down. */
239 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
240 cf_sk->sk.sk_err = ECONNRESET;
241 set_rx_flow_on(cf_sk);
242 sk_error_report(&cf_sk->sk);
243 break;
244
245 default:
246 pr_debug("Unexpected flow command %d\n", flow);
247 }
248}
249
250static void caif_check_flow_release(struct sock *sk)
251{
252 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
253
254 if (rx_flow_is_on(cf_sk))
255 return;
256
257 if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) {
258 set_rx_flow_on(cf_sk);
259 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ);
260 }
261}
262
263/*
264 * Copied from unix_dgram_recvmsg, but removed credit checks,
265 * changed locking, address handling and added MSG_TRUNC.
266 */
267static int caif_seqpkt_recvmsg(struct socket *sock, struct msghdr *m,
268 size_t len, int flags)
269
270{
271 struct sock *sk = sock->sk;
272 struct sk_buff *skb;
273 int ret;
274 int copylen;
275
276 ret = -EOPNOTSUPP;
277 if (flags & MSG_OOB)
278 goto read_error;
279
280 skb = skb_recv_datagram(sk, flags, &ret);
281 if (!skb)
282 goto read_error;
283 copylen = skb->len;
284 if (len < copylen) {
285 m->msg_flags |= MSG_TRUNC;
286 copylen = len;
287 }
288
289 ret = skb_copy_datagram_msg(skb, 0, m, copylen);
290 if (ret)
291 goto out_free;
292
293 ret = (flags & MSG_TRUNC) ? skb->len : copylen;
294out_free:
295 skb_free_datagram(sk, skb);
296 caif_check_flow_release(sk);
297 return ret;
298
299read_error:
300 return ret;
301}
302
303
304/* Copied from unix_stream_wait_data, identical except for lock call. */
305static long caif_stream_data_wait(struct sock *sk, long timeo)
306{
307 DEFINE_WAIT(wait);
308 lock_sock(sk);
309
310 for (;;) {
311 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
312
313 if (!skb_queue_empty(&sk->sk_receive_queue) ||
314 sk->sk_err ||
315 sk->sk_state != CAIF_CONNECTED ||
316 sock_flag(sk, SOCK_DEAD) ||
317 (sk->sk_shutdown & RCV_SHUTDOWN) ||
318 signal_pending(current) ||
319 !timeo)
320 break;
321
322 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
323 release_sock(sk);
324 timeo = schedule_timeout(timeo);
325 lock_sock(sk);
326
327 if (sock_flag(sk, SOCK_DEAD))
328 break;
329
330 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
331 }
332
333 finish_wait(sk_sleep(sk), &wait);
334 release_sock(sk);
335 return timeo;
336}
337
338
339/*
340 * Copied from unix_stream_recvmsg, but removed credit checks,
341 * changed locking calls, changed address handling.
342 */
343static int caif_stream_recvmsg(struct socket *sock, struct msghdr *msg,
344 size_t size, int flags)
345{
346 struct sock *sk = sock->sk;
347 int copied = 0;
348 int target;
349 int err = 0;
350 long timeo;
351
352 err = -EOPNOTSUPP;
353 if (flags&MSG_OOB)
354 goto out;
355
356 /*
357 * Lock the socket to prevent queue disordering
358 * while sleeps in memcpy_tomsg
359 */
360 err = -EAGAIN;
361 if (sk->sk_state == CAIF_CONNECTING)
362 goto out;
363
364 caif_read_lock(sk);
365 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
366 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
367
368 do {
369 int chunk;
370 struct sk_buff *skb;
371
372 lock_sock(sk);
373 if (sock_flag(sk, SOCK_DEAD)) {
374 err = -ECONNRESET;
375 goto unlock;
376 }
377 skb = skb_dequeue(&sk->sk_receive_queue);
378 caif_check_flow_release(sk);
379
380 if (skb == NULL) {
381 if (copied >= target)
382 goto unlock;
383 /*
384 * POSIX 1003.1g mandates this order.
385 */
386 err = sock_error(sk);
387 if (err)
388 goto unlock;
389 err = -ECONNRESET;
390 if (sk->sk_shutdown & RCV_SHUTDOWN)
391 goto unlock;
392
393 err = -EPIPE;
394 if (sk->sk_state != CAIF_CONNECTED)
395 goto unlock;
396 if (sock_flag(sk, SOCK_DEAD))
397 goto unlock;
398
399 release_sock(sk);
400
401 err = -EAGAIN;
402 if (!timeo)
403 break;
404
405 caif_read_unlock(sk);
406
407 timeo = caif_stream_data_wait(sk, timeo);
408
409 if (signal_pending(current)) {
410 err = sock_intr_errno(timeo);
411 goto out;
412 }
413 caif_read_lock(sk);
414 continue;
415unlock:
416 release_sock(sk);
417 break;
418 }
419 release_sock(sk);
420 chunk = min_t(unsigned int, skb->len, size);
421 if (memcpy_to_msg(msg, skb->data, chunk)) {
422 skb_queue_head(&sk->sk_receive_queue, skb);
423 if (copied == 0)
424 copied = -EFAULT;
425 break;
426 }
427 copied += chunk;
428 size -= chunk;
429
430 /* Mark read part of skb as used */
431 if (!(flags & MSG_PEEK)) {
432 skb_pull(skb, chunk);
433
434 /* put the skb back if we didn't use it up. */
435 if (skb->len) {
436 skb_queue_head(&sk->sk_receive_queue, skb);
437 break;
438 }
439 kfree_skb(skb);
440
441 } else {
442 /*
443 * It is questionable, see note in unix_dgram_recvmsg.
444 */
445 /* put message back and return */
446 skb_queue_head(&sk->sk_receive_queue, skb);
447 break;
448 }
449 } while (size);
450 caif_read_unlock(sk);
451
452out:
453 return copied ? : err;
454}
455
456/*
457 * Copied from sock.c:sock_wait_for_wmem, but change to wait for
458 * CAIF flow-on and sock_writable.
459 */
460static long caif_wait_for_flow_on(struct caifsock *cf_sk,
461 int wait_writeable, long timeo, int *err)
462{
463 struct sock *sk = &cf_sk->sk;
464 DEFINE_WAIT(wait);
465 for (;;) {
466 *err = 0;
467 if (tx_flow_is_on(cf_sk) &&
468 (!wait_writeable || sock_writeable(&cf_sk->sk)))
469 break;
470 *err = -ETIMEDOUT;
471 if (!timeo)
472 break;
473 *err = -ERESTARTSYS;
474 if (signal_pending(current))
475 break;
476 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
477 *err = -ECONNRESET;
478 if (sk->sk_shutdown & SHUTDOWN_MASK)
479 break;
480 *err = -sk->sk_err;
481 if (sk->sk_err)
482 break;
483 *err = -EPIPE;
484 if (cf_sk->sk.sk_state != CAIF_CONNECTED)
485 break;
486 timeo = schedule_timeout(timeo);
487 }
488 finish_wait(sk_sleep(sk), &wait);
489 return timeo;
490}
491
492/*
493 * Transmit a SKB. The device may temporarily request re-transmission
494 * by returning EAGAIN.
495 */
496static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk,
497 int noblock, long timeo)
498{
499 struct cfpkt *pkt;
500
501 pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb);
502 memset(skb->cb, 0, sizeof(struct caif_payload_info));
503 cfpkt_set_prio(pkt, cf_sk->sk.sk_priority);
504
505 if (cf_sk->layer.dn == NULL) {
506 kfree_skb(skb);
507 return -EINVAL;
508 }
509
510 return cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
511}
512
513/* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
514static int caif_seqpkt_sendmsg(struct socket *sock, struct msghdr *msg,
515 size_t len)
516{
517 struct sock *sk = sock->sk;
518 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
519 int buffer_size;
520 int ret = 0;
521 struct sk_buff *skb = NULL;
522 int noblock;
523 long timeo;
524 caif_assert(cf_sk);
525 ret = sock_error(sk);
526 if (ret)
527 goto err;
528
529 ret = -EOPNOTSUPP;
530 if (msg->msg_flags&MSG_OOB)
531 goto err;
532
533 ret = -EOPNOTSUPP;
534 if (msg->msg_namelen)
535 goto err;
536
537 noblock = msg->msg_flags & MSG_DONTWAIT;
538
539 timeo = sock_sndtimeo(sk, noblock);
540 timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
541 1, timeo, &ret);
542
543 if (ret)
544 goto err;
545 ret = -EPIPE;
546 if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
547 sock_flag(sk, SOCK_DEAD) ||
548 (sk->sk_shutdown & RCV_SHUTDOWN))
549 goto err;
550
551 /* Error if trying to write more than maximum frame size. */
552 ret = -EMSGSIZE;
553 if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM)
554 goto err;
555
556 buffer_size = len + cf_sk->headroom + cf_sk->tailroom;
557
558 ret = -ENOMEM;
559 skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
560
561 if (!skb || skb_tailroom(skb) < buffer_size)
562 goto err;
563
564 skb_reserve(skb, cf_sk->headroom);
565
566 ret = memcpy_from_msg(skb_put(skb, len), msg, len);
567
568 if (ret)
569 goto err;
570 ret = transmit_skb(skb, cf_sk, noblock, timeo);
571 if (ret < 0)
572 /* skb is already freed */
573 return ret;
574
575 return len;
576err:
577 kfree_skb(skb);
578 return ret;
579}
580
581/*
582 * Copied from unix_stream_sendmsg and adapted to CAIF:
583 * Changed removed permission handling and added waiting for flow on
584 * and other minor adaptations.
585 */
586static int caif_stream_sendmsg(struct socket *sock, struct msghdr *msg,
587 size_t len)
588{
589 struct sock *sk = sock->sk;
590 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
591 int err, size;
592 struct sk_buff *skb;
593 int sent = 0;
594 long timeo;
595
596 err = -EOPNOTSUPP;
597 if (unlikely(msg->msg_flags&MSG_OOB))
598 goto out_err;
599
600 if (unlikely(msg->msg_namelen))
601 goto out_err;
602
603 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
604 timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
605
606 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
607 goto pipe_err;
608
609 while (sent < len) {
610
611 size = len-sent;
612
613 if (size > cf_sk->maxframe)
614 size = cf_sk->maxframe;
615
616 /* If size is more than half of sndbuf, chop up message */
617 if (size > ((sk->sk_sndbuf >> 1) - 64))
618 size = (sk->sk_sndbuf >> 1) - 64;
619
620 if (size > SKB_MAX_ALLOC)
621 size = SKB_MAX_ALLOC;
622
623 skb = sock_alloc_send_skb(sk,
624 size + cf_sk->headroom +
625 cf_sk->tailroom,
626 msg->msg_flags&MSG_DONTWAIT,
627 &err);
628 if (skb == NULL)
629 goto out_err;
630
631 skb_reserve(skb, cf_sk->headroom);
632 /*
633 * If you pass two values to the sock_alloc_send_skb
634 * it tries to grab the large buffer with GFP_NOFS
635 * (which can fail easily), and if it fails grab the
636 * fallback size buffer which is under a page and will
637 * succeed. [Alan]
638 */
639 size = min_t(int, size, skb_tailroom(skb));
640
641 err = memcpy_from_msg(skb_put(skb, size), msg, size);
642 if (err) {
643 kfree_skb(skb);
644 goto out_err;
645 }
646 err = transmit_skb(skb, cf_sk,
647 msg->msg_flags&MSG_DONTWAIT, timeo);
648 if (err < 0)
649 /* skb is already freed */
650 goto pipe_err;
651
652 sent += size;
653 }
654
655 return sent;
656
657pipe_err:
658 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
659 send_sig(SIGPIPE, current, 0);
660 err = -EPIPE;
661out_err:
662 return sent ? : err;
663}
664
665static int setsockopt(struct socket *sock, int lvl, int opt, sockptr_t ov,
666 unsigned int ol)
667{
668 struct sock *sk = sock->sk;
669 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
670 int linksel;
671
672 if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
673 return -ENOPROTOOPT;
674
675 switch (opt) {
676 case CAIFSO_LINK_SELECT:
677 if (ol < sizeof(int))
678 return -EINVAL;
679 if (lvl != SOL_CAIF)
680 goto bad_sol;
681 if (copy_from_sockptr(&linksel, ov, sizeof(int)))
682 return -EINVAL;
683 lock_sock(&(cf_sk->sk));
684 cf_sk->conn_req.link_selector = linksel;
685 release_sock(&cf_sk->sk);
686 return 0;
687
688 case CAIFSO_REQ_PARAM:
689 if (lvl != SOL_CAIF)
690 goto bad_sol;
691 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
692 return -ENOPROTOOPT;
693 lock_sock(&(cf_sk->sk));
694 if (ol > sizeof(cf_sk->conn_req.param.data) ||
695 copy_from_sockptr(&cf_sk->conn_req.param.data, ov, ol)) {
696 release_sock(&cf_sk->sk);
697 return -EINVAL;
698 }
699 cf_sk->conn_req.param.size = ol;
700 release_sock(&cf_sk->sk);
701 return 0;
702
703 default:
704 return -ENOPROTOOPT;
705 }
706
707 return 0;
708bad_sol:
709 return -ENOPROTOOPT;
710
711}
712
713/*
714 * caif_connect() - Connect a CAIF Socket
715 * Copied and modified af_irda.c:irda_connect().
716 *
717 * Note : by consulting "errno", the user space caller may learn the cause
718 * of the failure. Most of them are visible in the function, others may come
719 * from subroutines called and are listed here :
720 * o -EAFNOSUPPORT: bad socket family or type.
721 * o -ESOCKTNOSUPPORT: bad socket type or protocol
722 * o -EINVAL: bad socket address, or CAIF link type
723 * o -ECONNREFUSED: remote end refused the connection.
724 * o -EINPROGRESS: connect request sent but timed out (or non-blocking)
725 * o -EISCONN: already connected.
726 * o -ETIMEDOUT: Connection timed out (send timeout)
727 * o -ENODEV: No link layer to send request
728 * o -ECONNRESET: Received Shutdown indication or lost link layer
729 * o -ENOMEM: Out of memory
730 *
731 * State Strategy:
732 * o sk_state: holds the CAIF_* protocol state, it's updated by
733 * caif_ctrl_cb.
734 * o sock->state: holds the SS_* socket state and is updated by connect and
735 * disconnect.
736 */
737static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
738 int addr_len, int flags)
739{
740 struct sock *sk = sock->sk;
741 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
742 long timeo;
743 int err;
744 int ifindex, headroom, tailroom;
745 unsigned int mtu;
746 struct net_device *dev;
747
748 lock_sock(sk);
749
750 err = -EINVAL;
751 if (addr_len < offsetofend(struct sockaddr, sa_family))
752 goto out;
753
754 err = -EAFNOSUPPORT;
755 if (uaddr->sa_family != AF_CAIF)
756 goto out;
757
758 switch (sock->state) {
759 case SS_UNCONNECTED:
760 /* Normal case, a fresh connect */
761 caif_assert(sk->sk_state == CAIF_DISCONNECTED);
762 break;
763 case SS_CONNECTING:
764 switch (sk->sk_state) {
765 case CAIF_CONNECTED:
766 sock->state = SS_CONNECTED;
767 err = -EISCONN;
768 goto out;
769 case CAIF_DISCONNECTED:
770 /* Reconnect allowed */
771 break;
772 case CAIF_CONNECTING:
773 err = -EALREADY;
774 if (flags & O_NONBLOCK)
775 goto out;
776 goto wait_connect;
777 }
778 break;
779 case SS_CONNECTED:
780 caif_assert(sk->sk_state == CAIF_CONNECTED ||
781 sk->sk_state == CAIF_DISCONNECTED);
782 if (sk->sk_shutdown & SHUTDOWN_MASK) {
783 /* Allow re-connect after SHUTDOWN_IND */
784 caif_disconnect_client(sock_net(sk), &cf_sk->layer);
785 caif_free_client(&cf_sk->layer);
786 break;
787 }
788 /* No reconnect on a seqpacket socket */
789 err = -EISCONN;
790 goto out;
791 case SS_DISCONNECTING:
792 case SS_FREE:
793 caif_assert(1); /*Should never happen */
794 break;
795 }
796 sk->sk_state = CAIF_DISCONNECTED;
797 sock->state = SS_UNCONNECTED;
798 sk_stream_kill_queues(&cf_sk->sk);
799
800 err = -EINVAL;
801 if (addr_len != sizeof(struct sockaddr_caif))
802 goto out;
803
804 memcpy(&cf_sk->conn_req.sockaddr, uaddr,
805 sizeof(struct sockaddr_caif));
806
807 /* Move to connecting socket, start sending Connect Requests */
808 sock->state = SS_CONNECTING;
809 sk->sk_state = CAIF_CONNECTING;
810
811 /* Check priority value comming from socket */
812 /* if priority value is out of range it will be ajusted */
813 if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX)
814 cf_sk->conn_req.priority = CAIF_PRIO_MAX;
815 else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN)
816 cf_sk->conn_req.priority = CAIF_PRIO_MIN;
817 else
818 cf_sk->conn_req.priority = cf_sk->sk.sk_priority;
819
820 /*ifindex = id of the interface.*/
821 cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if;
822
823 cf_sk->layer.receive = caif_sktrecv_cb;
824
825 err = caif_connect_client(sock_net(sk), &cf_sk->conn_req,
826 &cf_sk->layer, &ifindex, &headroom, &tailroom);
827
828 if (err < 0) {
829 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
830 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
831 goto out;
832 }
833
834 err = -ENODEV;
835 rcu_read_lock();
836 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
837 if (!dev) {
838 rcu_read_unlock();
839 goto out;
840 }
841 cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom);
842 mtu = dev->mtu;
843 rcu_read_unlock();
844
845 cf_sk->tailroom = tailroom;
846 cf_sk->maxframe = mtu - (headroom + tailroom);
847 if (cf_sk->maxframe < 1) {
848 pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu);
849 err = -ENODEV;
850 goto out;
851 }
852
853 err = -EINPROGRESS;
854wait_connect:
855
856 if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
857 goto out;
858
859 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
860
861 release_sock(sk);
862 err = -ERESTARTSYS;
863 timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
864 sk->sk_state != CAIF_CONNECTING,
865 timeo);
866 lock_sock(sk);
867 if (timeo < 0)
868 goto out; /* -ERESTARTSYS */
869
870 err = -ETIMEDOUT;
871 if (timeo == 0 && sk->sk_state != CAIF_CONNECTED)
872 goto out;
873 if (sk->sk_state != CAIF_CONNECTED) {
874 sock->state = SS_UNCONNECTED;
875 err = sock_error(sk);
876 if (!err)
877 err = -ECONNREFUSED;
878 goto out;
879 }
880 sock->state = SS_CONNECTED;
881 err = 0;
882out:
883 release_sock(sk);
884 return err;
885}
886
887/*
888 * caif_release() - Disconnect a CAIF Socket
889 * Copied and modified af_irda.c:irda_release().
890 */
891static int caif_release(struct socket *sock)
892{
893 struct sock *sk = sock->sk;
894 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
895
896 if (!sk)
897 return 0;
898
899 set_tx_flow_off(cf_sk);
900
901 /*
902 * Ensure that packets are not queued after this point in time.
903 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
904 * this ensures no packets when sock is dead.
905 */
906 spin_lock_bh(&sk->sk_receive_queue.lock);
907 sock_set_flag(sk, SOCK_DEAD);
908 spin_unlock_bh(&sk->sk_receive_queue.lock);
909 sock->sk = NULL;
910
911 WARN_ON(IS_ERR(cf_sk->debugfs_socket_dir));
912 debugfs_remove_recursive(cf_sk->debugfs_socket_dir);
913
914 lock_sock(&(cf_sk->sk));
915 sk->sk_state = CAIF_DISCONNECTED;
916 sk->sk_shutdown = SHUTDOWN_MASK;
917
918 caif_disconnect_client(sock_net(sk), &cf_sk->layer);
919 cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
920 wake_up_interruptible_poll(sk_sleep(sk), EPOLLERR|EPOLLHUP);
921
922 sock_orphan(sk);
923 sk_stream_kill_queues(&cf_sk->sk);
924 release_sock(sk);
925 sock_put(sk);
926 return 0;
927}
928
929/* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */
930static __poll_t caif_poll(struct file *file,
931 struct socket *sock, poll_table *wait)
932{
933 struct sock *sk = sock->sk;
934 __poll_t mask;
935 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
936
937 sock_poll_wait(file, sock, wait);
938 mask = 0;
939
940 /* exceptional events? */
941 if (sk->sk_err)
942 mask |= EPOLLERR;
943 if (sk->sk_shutdown == SHUTDOWN_MASK)
944 mask |= EPOLLHUP;
945 if (sk->sk_shutdown & RCV_SHUTDOWN)
946 mask |= EPOLLRDHUP;
947
948 /* readable? */
949 if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
950 (sk->sk_shutdown & RCV_SHUTDOWN))
951 mask |= EPOLLIN | EPOLLRDNORM;
952
953 /*
954 * we set writable also when the other side has shut down the
955 * connection. This prevents stuck sockets.
956 */
957 if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
958 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
959
960 return mask;
961}
962
963static const struct proto_ops caif_seqpacket_ops = {
964 .family = PF_CAIF,
965 .owner = THIS_MODULE,
966 .release = caif_release,
967 .bind = sock_no_bind,
968 .connect = caif_connect,
969 .socketpair = sock_no_socketpair,
970 .accept = sock_no_accept,
971 .getname = sock_no_getname,
972 .poll = caif_poll,
973 .ioctl = sock_no_ioctl,
974 .listen = sock_no_listen,
975 .shutdown = sock_no_shutdown,
976 .setsockopt = setsockopt,
977 .sendmsg = caif_seqpkt_sendmsg,
978 .recvmsg = caif_seqpkt_recvmsg,
979 .mmap = sock_no_mmap,
980};
981
982static const struct proto_ops caif_stream_ops = {
983 .family = PF_CAIF,
984 .owner = THIS_MODULE,
985 .release = caif_release,
986 .bind = sock_no_bind,
987 .connect = caif_connect,
988 .socketpair = sock_no_socketpair,
989 .accept = sock_no_accept,
990 .getname = sock_no_getname,
991 .poll = caif_poll,
992 .ioctl = sock_no_ioctl,
993 .listen = sock_no_listen,
994 .shutdown = sock_no_shutdown,
995 .setsockopt = setsockopt,
996 .sendmsg = caif_stream_sendmsg,
997 .recvmsg = caif_stream_recvmsg,
998 .mmap = sock_no_mmap,
999};
1000
1001/* This function is called when a socket is finally destroyed. */
1002static void caif_sock_destructor(struct sock *sk)
1003{
1004 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1005 caif_assert(!refcount_read(&sk->sk_wmem_alloc));
1006 caif_assert(sk_unhashed(sk));
1007 caif_assert(!sk->sk_socket);
1008 if (!sock_flag(sk, SOCK_DEAD)) {
1009 pr_debug("Attempt to release alive CAIF socket: %p\n", sk);
1010 return;
1011 }
1012 sk_stream_kill_queues(&cf_sk->sk);
1013 WARN_ON_ONCE(sk->sk_forward_alloc);
1014 caif_free_client(&cf_sk->layer);
1015}
1016
1017static int caif_create(struct net *net, struct socket *sock, int protocol,
1018 int kern)
1019{
1020 struct sock *sk = NULL;
1021 struct caifsock *cf_sk = NULL;
1022 static struct proto prot = {.name = "PF_CAIF",
1023 .owner = THIS_MODULE,
1024 .obj_size = sizeof(struct caifsock),
1025 .useroffset = offsetof(struct caifsock, conn_req.param),
1026 .usersize = sizeof_field(struct caifsock, conn_req.param)
1027 };
1028
1029 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
1030 return -EPERM;
1031 /*
1032 * The sock->type specifies the socket type to use.
1033 * The CAIF socket is a packet stream in the sense
1034 * that it is packet based. CAIF trusts the reliability
1035 * of the link, no resending is implemented.
1036 */
1037 if (sock->type == SOCK_SEQPACKET)
1038 sock->ops = &caif_seqpacket_ops;
1039 else if (sock->type == SOCK_STREAM)
1040 sock->ops = &caif_stream_ops;
1041 else
1042 return -ESOCKTNOSUPPORT;
1043
1044 if (protocol < 0 || protocol >= CAIFPROTO_MAX)
1045 return -EPROTONOSUPPORT;
1046 /*
1047 * Set the socket state to unconnected. The socket state
1048 * is really not used at all in the net/core or socket.c but the
1049 * initialization makes sure that sock->state is not uninitialized.
1050 */
1051 sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot, kern);
1052 if (!sk)
1053 return -ENOMEM;
1054
1055 cf_sk = container_of(sk, struct caifsock, sk);
1056
1057 /* Store the protocol */
1058 sk->sk_protocol = (unsigned char) protocol;
1059
1060 /* Initialize default priority for well-known cases */
1061 switch (protocol) {
1062 case CAIFPROTO_AT:
1063 sk->sk_priority = TC_PRIO_CONTROL;
1064 break;
1065 case CAIFPROTO_RFM:
1066 sk->sk_priority = TC_PRIO_INTERACTIVE_BULK;
1067 break;
1068 default:
1069 sk->sk_priority = TC_PRIO_BESTEFFORT;
1070 }
1071
1072 /*
1073 * Lock in order to try to stop someone from opening the socket
1074 * too early.
1075 */
1076 lock_sock(&(cf_sk->sk));
1077
1078 /* Initialize the nozero default sock structure data. */
1079 sock_init_data(sock, sk);
1080 sk->sk_destruct = caif_sock_destructor;
1081
1082 mutex_init(&cf_sk->readlock); /* single task reading lock */
1083 cf_sk->layer.ctrlcmd = caif_ctrl_cb;
1084 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
1085 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
1086
1087 set_tx_flow_off(cf_sk);
1088 set_rx_flow_on(cf_sk);
1089
1090 /* Set default options on configuration */
1091 cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1092 cf_sk->conn_req.protocol = protocol;
1093 release_sock(&cf_sk->sk);
1094 return 0;
1095}
1096
1097
1098static const struct net_proto_family caif_family_ops = {
1099 .family = PF_CAIF,
1100 .create = caif_create,
1101 .owner = THIS_MODULE,
1102};
1103
1104static int __init caif_sktinit_module(void)
1105{
1106 return sock_register(&caif_family_ops);
1107}
1108
1109static void __exit caif_sktexit_module(void)
1110{
1111 sock_unregister(PF_CAIF);
1112}
1113module_init(caif_sktinit_module);
1114module_exit(caif_sktexit_module);