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Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs
[linux/fpc-iii.git] / net / caif / caif_socket.c
blob3d0e09584fae59611c1599503356eef19f7c0379
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 #include <linux/fs.h>
8 #include <linux/init.h>
9 #include <linux/module.h>
10 #include <linux/sched.h>
11 #include <linux/spinlock.h>
12 #include <linux/mutex.h>
13 #include <linux/list.h>
14 #include <linux/wait.h>
15 #include <linux/poll.h>
16 #include <linux/tcp.h>
17 #include <linux/uaccess.h>
18 #include <linux/mutex.h>
19 #include <linux/debugfs.h>
20 #include <linux/caif/caif_socket.h>
21 #include <asm/atomic.h>
22 #include <net/sock.h>
23 #include <net/tcp_states.h>
24 #include <net/caif/caif_layer.h>
25 #include <net/caif/caif_dev.h>
26 #include <net/caif/cfpkt.h>
27
28 MODULE_LICENSE("GPL");
29 MODULE_ALIAS_NETPROTO(AF_CAIF);
30
31 #define CAIF_DEF_SNDBUF (CAIF_MAX_PAYLOAD_SIZE*10)
32 #define CAIF_DEF_RCVBUF (CAIF_MAX_PAYLOAD_SIZE*100)
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 */
39 enum 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
48 static struct dentry *debugfsdir;
49
50 #ifdef CONFIG_DEBUG_FS
51 struct debug_fs_counter {
52 atomic_t caif_nr_socks;
53 atomic_t num_connect_req;
54 atomic_t num_connect_resp;
55 atomic_t num_connect_fail_resp;
56 atomic_t num_disconnect;
57 atomic_t num_remote_shutdown_ind;
58 atomic_t num_tx_flow_off_ind;
59 atomic_t num_tx_flow_on_ind;
60 atomic_t num_rx_flow_off;
61 atomic_t num_rx_flow_on;
62 };
63 static struct debug_fs_counter cnt;
64 #define dbfs_atomic_inc(v) atomic_inc(v)
65 #define dbfs_atomic_dec(v) atomic_dec(v)
66 #else
67 #define dbfs_atomic_inc(v)
68 #define dbfs_atomic_dec(v)
69 #endif
70
71 struct caifsock {
72 struct sock sk; /* must be first member */
73 struct cflayer layer;
74 char name[CAIF_LAYER_NAME_SZ]; /* Used for debugging */
75 u32 flow_state;
76 struct caif_connect_request conn_req;
77 struct mutex readlock;
78 struct dentry *debugfs_socket_dir;
79 };
80
81 static 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
87 static 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
93 static 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
99 static 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
105 static 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
111 static 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
117 static 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
124 static 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
131 static 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
137 static 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 */
149 static 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 trace_printk("CAIF: %s():"
160 " sending flow OFF (queue len = %d %d)\n",
161 __func__,
162 atomic_read(&cf_sk->sk.sk_rmem_alloc),
163 sk_rcvbuf_lowwater(cf_sk));
164 set_rx_flow_off(cf_sk);
165 dbfs_atomic_inc(&cnt.num_rx_flow_off);
166 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
167 }
168
169 err = sk_filter(sk, skb);
170 if (err)
171 return err;
172 if (!sk_rmem_schedule(sk, skb->truesize) && rx_flow_is_on(cf_sk)) {
173 set_rx_flow_off(cf_sk);
174 trace_printk("CAIF: %s():"
175 " sending flow OFF due to rmem_schedule\n",
176 __func__);
177 dbfs_atomic_inc(&cnt.num_rx_flow_off);
178 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
179 }
180 skb->dev = NULL;
181 skb_set_owner_r(skb, sk);
182 /* Cache the SKB length before we tack it onto the receive
183 * queue. Once it is added it no longer belongs to us and
184 * may be freed by other threads of control pulling packets
185 * from the queue.
186 */
187 skb_len = skb->len;
188 spin_lock_irqsave(&list->lock, flags);
189 if (!sock_flag(sk, SOCK_DEAD))
190 __skb_queue_tail(list, skb);
191 spin_unlock_irqrestore(&list->lock, flags);
192
193 if (!sock_flag(sk, SOCK_DEAD))
194 sk->sk_data_ready(sk, skb_len);
195 else
196 kfree_skb(skb);
197 return 0;
198 }
199
200 /* Packet Receive Callback function called from CAIF Stack */
201 static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
202 {
203 struct caifsock *cf_sk;
204 struct sk_buff *skb;
205
206 cf_sk = container_of(layr, struct caifsock, layer);
207 skb = cfpkt_tonative(pkt);
208
209 if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) {
210 cfpkt_destroy(pkt);
211 return 0;
212 }
213 caif_queue_rcv_skb(&cf_sk->sk, skb);
214 return 0;
215 }
216
217 /* Packet Control Callback function called from CAIF */
218 static void caif_ctrl_cb(struct cflayer *layr,
219 enum caif_ctrlcmd flow,
220 int phyid)
221 {
222 struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
223 switch (flow) {
224 case CAIF_CTRLCMD_FLOW_ON_IND:
225 /* OK from modem to start sending again */
226 dbfs_atomic_inc(&cnt.num_tx_flow_on_ind);
227 set_tx_flow_on(cf_sk);
228 cf_sk->sk.sk_state_change(&cf_sk->sk);
229 break;
230
231 case CAIF_CTRLCMD_FLOW_OFF_IND:
232 /* Modem asks us to shut up */
233 dbfs_atomic_inc(&cnt.num_tx_flow_off_ind);
234 set_tx_flow_off(cf_sk);
235 cf_sk->sk.sk_state_change(&cf_sk->sk);
236 break;
237
238 case CAIF_CTRLCMD_INIT_RSP:
239 /* We're now connected */
240 dbfs_atomic_inc(&cnt.num_connect_resp);
241 cf_sk->sk.sk_state = CAIF_CONNECTED;
242 set_tx_flow_on(cf_sk);
243 cf_sk->sk.sk_state_change(&cf_sk->sk);
244 break;
245
246 case CAIF_CTRLCMD_DEINIT_RSP:
247 /* We're now disconnected */
248 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
249 cf_sk->sk.sk_state_change(&cf_sk->sk);
250 cfcnfg_release_adap_layer(&cf_sk->layer);
251 break;
252
253 case CAIF_CTRLCMD_INIT_FAIL_RSP:
254 /* Connect request failed */
255 dbfs_atomic_inc(&cnt.num_connect_fail_resp);
256 cf_sk->sk.sk_err = ECONNREFUSED;
257 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
258 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
259 /*
260 * Socket "standards" seems to require POLLOUT to
261 * be set at connect failure.
262 */
263 set_tx_flow_on(cf_sk);
264 cf_sk->sk.sk_state_change(&cf_sk->sk);
265 break;
266
267 case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
268 /* Modem has closed this connection, or device is down. */
269 dbfs_atomic_inc(&cnt.num_remote_shutdown_ind);
270 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
271 cf_sk->sk.sk_err = ECONNRESET;
272 set_rx_flow_on(cf_sk);
273 cf_sk->sk.sk_error_report(&cf_sk->sk);
274 break;
275
276 default:
277 pr_debug("CAIF: %s(): Unexpected flow command %d\n",
278 __func__, flow);
279 }
280 }
281
282 static void caif_check_flow_release(struct sock *sk)
283 {
284 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
285
286 if (rx_flow_is_on(cf_sk))
287 return;
288
289 if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) {
290 dbfs_atomic_inc(&cnt.num_rx_flow_on);
291 set_rx_flow_on(cf_sk);
292 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ);
293 }
294 }
295
296 /*
297 * Copied from unix_dgram_recvmsg, but removed credit checks,
298 * changed locking, address handling and added MSG_TRUNC.
299 */
300 static int caif_seqpkt_recvmsg(struct kiocb *iocb, struct socket *sock,
301 struct msghdr *m, size_t len, int flags)
302
303 {
304 struct sock *sk = sock->sk;
305 struct sk_buff *skb;
306 int ret;
307 int copylen;
308
309 ret = -EOPNOTSUPP;
310 if (m->msg_flags&MSG_OOB)
311 goto read_error;
312
313 skb = skb_recv_datagram(sk, flags, 0 , &ret);
314 if (!skb)
315 goto read_error;
316 copylen = skb->len;
317 if (len < copylen) {
318 m->msg_flags |= MSG_TRUNC;
319 copylen = len;
320 }
321
322 ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, copylen);
323 if (ret)
324 goto out_free;
325
326 ret = (flags & MSG_TRUNC) ? skb->len : copylen;
327 out_free:
328 skb_free_datagram(sk, skb);
329 caif_check_flow_release(sk);
330 return ret;
331
332 read_error:
333 return ret;
334 }
335
336
337 /* Copied from unix_stream_wait_data, identical except for lock call. */
338 static long caif_stream_data_wait(struct sock *sk, long timeo)
339 {
340 DEFINE_WAIT(wait);
341 lock_sock(sk);
342
343 for (;;) {
344 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
345
346 if (!skb_queue_empty(&sk->sk_receive_queue) ||
347 sk->sk_err ||
348 sk->sk_state != CAIF_CONNECTED ||
349 sock_flag(sk, SOCK_DEAD) ||
350 (sk->sk_shutdown & RCV_SHUTDOWN) ||
351 signal_pending(current) ||
352 !timeo)
353 break;
354
355 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
356 release_sock(sk);
357 timeo = schedule_timeout(timeo);
358 lock_sock(sk);
359 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
360 }
361
362 finish_wait(sk_sleep(sk), &wait);
363 release_sock(sk);
364 return timeo;
365 }
366
367
368 /*
369 * Copied from unix_stream_recvmsg, but removed credit checks,
370 * changed locking calls, changed address handling.
371 */
372 static int caif_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
373 struct msghdr *msg, size_t size,
374 int flags)
375 {
376 struct sock *sk = sock->sk;
377 int copied = 0;
378 int target;
379 int err = 0;
380 long timeo;
381
382 err = -EOPNOTSUPP;
383 if (flags&MSG_OOB)
384 goto out;
385
386 msg->msg_namelen = 0;
387
388 /*
389 * Lock the socket to prevent queue disordering
390 * while sleeps in memcpy_tomsg
391 */
392 err = -EAGAIN;
393 if (sk->sk_state == CAIF_CONNECTING)
394 goto out;
395
396 caif_read_lock(sk);
397 target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
398 timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
399
400 do {
401 int chunk;
402 struct sk_buff *skb;
403
404 lock_sock(sk);
405 skb = skb_dequeue(&sk->sk_receive_queue);
406 caif_check_flow_release(sk);
407
408 if (skb == NULL) {
409 if (copied >= target)
410 goto unlock;
411 /*
412 * POSIX 1003.1g mandates this order.
413 */
414 err = sock_error(sk);
415 if (err)
416 goto unlock;
417 err = -ECONNRESET;
418 if (sk->sk_shutdown & RCV_SHUTDOWN)
419 goto unlock;
420
421 err = -EPIPE;
422 if (sk->sk_state != CAIF_CONNECTED)
423 goto unlock;
424 if (sock_flag(sk, SOCK_DEAD))
425 goto unlock;
426
427 release_sock(sk);
428
429 err = -EAGAIN;
430 if (!timeo)
431 break;
432
433 caif_read_unlock(sk);
434
435 timeo = caif_stream_data_wait(sk, timeo);
436
437 if (signal_pending(current)) {
438 err = sock_intr_errno(timeo);
439 goto out;
440 }
441 caif_read_lock(sk);
442 continue;
443 unlock:
444 release_sock(sk);
445 break;
446 }
447 release_sock(sk);
448 chunk = min_t(unsigned int, skb->len, size);
449 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
450 skb_queue_head(&sk->sk_receive_queue, skb);
451 if (copied == 0)
452 copied = -EFAULT;
453 break;
454 }
455 copied += chunk;
456 size -= chunk;
457
458 /* Mark read part of skb as used */
459 if (!(flags & MSG_PEEK)) {
460 skb_pull(skb, chunk);
461
462 /* put the skb back if we didn't use it up. */
463 if (skb->len) {
464 skb_queue_head(&sk->sk_receive_queue, skb);
465 break;
466 }
467 kfree_skb(skb);
468
469 } else {
470 /*
471 * It is questionable, see note in unix_dgram_recvmsg.
472 */
473 /* put message back and return */
474 skb_queue_head(&sk->sk_receive_queue, skb);
475 break;
476 }
477 } while (size);
478 caif_read_unlock(sk);
479
480 out:
481 return copied ? : err;
482 }
483
484 /*
485 * Copied from sock.c:sock_wait_for_wmem, but change to wait for
486 * CAIF flow-on and sock_writable.
487 */
488 static long caif_wait_for_flow_on(struct caifsock *cf_sk,
489 int wait_writeable, long timeo, int *err)
490 {
491 struct sock *sk = &cf_sk->sk;
492 DEFINE_WAIT(wait);
493 for (;;) {
494 *err = 0;
495 if (tx_flow_is_on(cf_sk) &&
496 (!wait_writeable || sock_writeable(&cf_sk->sk)))
497 break;
498 *err = -ETIMEDOUT;
499 if (!timeo)
500 break;
501 *err = -ERESTARTSYS;
502 if (signal_pending(current))
503 break;
504 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
505 *err = -ECONNRESET;
506 if (sk->sk_shutdown & SHUTDOWN_MASK)
507 break;
508 *err = -sk->sk_err;
509 if (sk->sk_err)
510 break;
511 *err = -EPIPE;
512 if (cf_sk->sk.sk_state != CAIF_CONNECTED)
513 break;
514 timeo = schedule_timeout(timeo);
515 }
516 finish_wait(sk_sleep(sk), &wait);
517 return timeo;
518 }
519
520 /*
521 * Transmit a SKB. The device may temporarily request re-transmission
522 * by returning EAGAIN.
523 */
524 static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk,
525 int noblock, long timeo)
526 {
527 struct cfpkt *pkt;
528 int ret, loopcnt = 0;
529
530 pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb);
531 memset(cfpkt_info(pkt), 0, sizeof(struct caif_payload_info));
532 do {
533
534 ret = -ETIMEDOUT;
535
536 /* Slight paranoia, probably not needed. */
537 if (unlikely(loopcnt++ > 1000)) {
538 pr_warning("CAIF: %s(): transmit retries failed,"
539 " error = %d\n", __func__, ret);
540 break;
541 }
542
543 if (cf_sk->layer.dn != NULL)
544 ret = cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
545 if (likely(ret >= 0))
546 break;
547 /* if transmit return -EAGAIN, then retry */
548 if (noblock && ret == -EAGAIN)
549 break;
550 timeo = caif_wait_for_flow_on(cf_sk, 0, timeo, &ret);
551 if (signal_pending(current)) {
552 ret = sock_intr_errno(timeo);
553 break;
554 }
555 if (ret)
556 break;
557 if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
558 sock_flag(&cf_sk->sk, SOCK_DEAD) ||
559 (cf_sk->sk.sk_shutdown & RCV_SHUTDOWN)) {
560 ret = -EPIPE;
561 cf_sk->sk.sk_err = EPIPE;
562 break;
563 }
564 } while (ret == -EAGAIN);
565 return ret;
566 }
567
568 /* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
569 static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock,
570 struct msghdr *msg, size_t len)
571 {
572 struct sock *sk = sock->sk;
573 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
574 int buffer_size;
575 int ret = 0;
576 struct sk_buff *skb = NULL;
577 int noblock;
578 long timeo;
579 caif_assert(cf_sk);
580 ret = sock_error(sk);
581 if (ret)
582 goto err;
583
584 ret = -EOPNOTSUPP;
585 if (msg->msg_flags&MSG_OOB)
586 goto err;
587
588 ret = -EOPNOTSUPP;
589 if (msg->msg_namelen)
590 goto err;
591
592 ret = -EINVAL;
593 if (unlikely(msg->msg_iov->iov_base == NULL))
594 goto err;
595 noblock = msg->msg_flags & MSG_DONTWAIT;
596
597 buffer_size = len + CAIF_NEEDED_HEADROOM + CAIF_NEEDED_TAILROOM;
598
599 ret = -EMSGSIZE;
600 if (buffer_size > CAIF_MAX_PAYLOAD_SIZE)
601 goto err;
602
603 timeo = sock_sndtimeo(sk, noblock);
604 timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
605 1, timeo, &ret);
606
607 ret = -EPIPE;
608 if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
609 sock_flag(sk, SOCK_DEAD) ||
610 (sk->sk_shutdown & RCV_SHUTDOWN))
611 goto err;
612
613 ret = -ENOMEM;
614 skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
615 if (!skb)
616 goto err;
617 skb_reserve(skb, CAIF_NEEDED_HEADROOM);
618
619 ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
620
621 if (ret)
622 goto err;
623 ret = transmit_skb(skb, cf_sk, noblock, timeo);
624 if (ret < 0)
625 goto err;
626 return len;
627 err:
628 kfree_skb(skb);
629 return ret;
630 }
631
632 /*
633 * Copied from unix_stream_sendmsg and adapted to CAIF:
634 * Changed removed permission handling and added waiting for flow on
635 * and other minor adaptations.
636 */
637 static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
638 struct msghdr *msg, size_t len)
639 {
640 struct sock *sk = sock->sk;
641 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
642 int err, size;
643 struct sk_buff *skb;
644 int sent = 0;
645 long timeo;
646
647 err = -EOPNOTSUPP;
648
649 if (unlikely(msg->msg_flags&MSG_OOB))
650 goto out_err;
651
652 if (unlikely(msg->msg_namelen))
653 goto out_err;
654
655 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
656 timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
657
658 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
659 goto pipe_err;
660
661 while (sent < len) {
662
663 size = len-sent;
664
665 if (size > CAIF_MAX_PAYLOAD_SIZE)
666 size = CAIF_MAX_PAYLOAD_SIZE;
667
668 /* If size is more than half of sndbuf, chop up message */
669 if (size > ((sk->sk_sndbuf >> 1) - 64))
670 size = (sk->sk_sndbuf >> 1) - 64;
671
672 if (size > SKB_MAX_ALLOC)
673 size = SKB_MAX_ALLOC;
674
675 skb = sock_alloc_send_skb(sk,
676 size + CAIF_NEEDED_HEADROOM
677 + CAIF_NEEDED_TAILROOM,
678 msg->msg_flags&MSG_DONTWAIT,
679 &err);
680 if (skb == NULL)
681 goto out_err;
682
683 skb_reserve(skb, CAIF_NEEDED_HEADROOM);
684 /*
685 * If you pass two values to the sock_alloc_send_skb
686 * it tries to grab the large buffer with GFP_NOFS
687 * (which can fail easily), and if it fails grab the
688 * fallback size buffer which is under a page and will
689 * succeed. [Alan]
690 */
691 size = min_t(int, size, skb_tailroom(skb));
692
693 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
694 if (err) {
695 kfree_skb(skb);
696 goto out_err;
697 }
698 err = transmit_skb(skb, cf_sk,
699 msg->msg_flags&MSG_DONTWAIT, timeo);
700 if (err < 0) {
701 kfree_skb(skb);
702 goto pipe_err;
703 }
704 sent += size;
705 }
706
707 return sent;
708
709 pipe_err:
710 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
711 send_sig(SIGPIPE, current, 0);
712 err = -EPIPE;
713 out_err:
714 return sent ? : err;
715 }
716
717 static int setsockopt(struct socket *sock,
718 int lvl, int opt, char __user *ov, unsigned int ol)
719 {
720 struct sock *sk = sock->sk;
721 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
722 int prio, linksel;
723 struct ifreq ifreq;
724
725 if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
726 return -ENOPROTOOPT;
727
728 switch (opt) {
729 case CAIFSO_LINK_SELECT:
730 if (ol < sizeof(int))
731 return -EINVAL;
732 if (lvl != SOL_CAIF)
733 goto bad_sol;
734 if (copy_from_user(&linksel, ov, sizeof(int)))
735 return -EINVAL;
736 lock_sock(&(cf_sk->sk));
737 cf_sk->conn_req.link_selector = linksel;
738 release_sock(&cf_sk->sk);
739 return 0;
740
741 case SO_PRIORITY:
742 if (lvl != SOL_SOCKET)
743 goto bad_sol;
744 if (ol < sizeof(int))
745 return -EINVAL;
746 if (copy_from_user(&prio, ov, sizeof(int)))
747 return -EINVAL;
748 lock_sock(&(cf_sk->sk));
749 cf_sk->conn_req.priority = prio;
750 release_sock(&cf_sk->sk);
751 return 0;
752
753 case SO_BINDTODEVICE:
754 if (lvl != SOL_SOCKET)
755 goto bad_sol;
756 if (ol < sizeof(struct ifreq))
757 return -EINVAL;
758 if (copy_from_user(&ifreq, ov, sizeof(ifreq)))
759 return -EFAULT;
760 lock_sock(&(cf_sk->sk));
761 strncpy(cf_sk->conn_req.link_name, ifreq.ifr_name,
762 sizeof(cf_sk->conn_req.link_name));
763 cf_sk->conn_req.link_name
764 [sizeof(cf_sk->conn_req.link_name)-1] = 0;
765 release_sock(&cf_sk->sk);
766 return 0;
767
768 case CAIFSO_REQ_PARAM:
769 if (lvl != SOL_CAIF)
770 goto bad_sol;
771 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
772 return -ENOPROTOOPT;
773 lock_sock(&(cf_sk->sk));
774 cf_sk->conn_req.param.size = ol;
775 if (ol > sizeof(cf_sk->conn_req.param.data) ||
776 copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) {
777 release_sock(&cf_sk->sk);
778 return -EINVAL;
779 }
780 release_sock(&cf_sk->sk);
781 return 0;
782
783 default:
784 return -ENOPROTOOPT;
785 }
786
787 return 0;
788 bad_sol:
789 return -ENOPROTOOPT;
790
791 }
792
793 /*
794 * caif_connect() - Connect a CAIF Socket
795 * Copied and modified af_irda.c:irda_connect().
796 *
797 * Note : by consulting "errno", the user space caller may learn the cause
798 * of the failure. Most of them are visible in the function, others may come
799 * from subroutines called and are listed here :
800 * o -EAFNOSUPPORT: bad socket family or type.
801 * o -ESOCKTNOSUPPORT: bad socket type or protocol
802 * o -EINVAL: bad socket address, or CAIF link type
803 * o -ECONNREFUSED: remote end refused the connection.
804 * o -EINPROGRESS: connect request sent but timed out (or non-blocking)
805 * o -EISCONN: already connected.
806 * o -ETIMEDOUT: Connection timed out (send timeout)
807 * o -ENODEV: No link layer to send request
808 * o -ECONNRESET: Received Shutdown indication or lost link layer
809 * o -ENOMEM: Out of memory
810 *
811 * State Strategy:
812 * o sk_state: holds the CAIF_* protocol state, it's updated by
813 * caif_ctrl_cb.
814 * o sock->state: holds the SS_* socket state and is updated by connect and
815 * disconnect.
816 */
817 static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
818 int addr_len, int flags)
819 {
820 struct sock *sk = sock->sk;
821 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
822 long timeo;
823 int err;
824 lock_sock(sk);
825
826 err = -EAFNOSUPPORT;
827 if (uaddr->sa_family != AF_CAIF)
828 goto out;
829
830 err = -ESOCKTNOSUPPORT;
831 if (unlikely(!(sk->sk_type == SOCK_STREAM &&
832 cf_sk->sk.sk_protocol == CAIFPROTO_AT) &&
833 sk->sk_type != SOCK_SEQPACKET))
834 goto out;
835 switch (sock->state) {
836 case SS_UNCONNECTED:
837 /* Normal case, a fresh connect */
838 caif_assert(sk->sk_state == CAIF_DISCONNECTED);
839 break;
840 case SS_CONNECTING:
841 switch (sk->sk_state) {
842 case CAIF_CONNECTED:
843 sock->state = SS_CONNECTED;
844 err = -EISCONN;
845 goto out;
846 case CAIF_DISCONNECTED:
847 /* Reconnect allowed */
848 break;
849 case CAIF_CONNECTING:
850 err = -EALREADY;
851 if (flags & O_NONBLOCK)
852 goto out;
853 goto wait_connect;
854 }
855 break;
856 case SS_CONNECTED:
857 caif_assert(sk->sk_state == CAIF_CONNECTED ||
858 sk->sk_state == CAIF_DISCONNECTED);
859 if (sk->sk_shutdown & SHUTDOWN_MASK) {
860 /* Allow re-connect after SHUTDOWN_IND */
861 caif_disconnect_client(&cf_sk->layer);
862 break;
863 }
864 /* No reconnect on a seqpacket socket */
865 err = -EISCONN;
866 goto out;
867 case SS_DISCONNECTING:
868 case SS_FREE:
869 caif_assert(1); /*Should never happen */
870 break;
871 }
872 sk->sk_state = CAIF_DISCONNECTED;
873 sock->state = SS_UNCONNECTED;
874 sk_stream_kill_queues(&cf_sk->sk);
875
876 err = -EINVAL;
877 if (addr_len != sizeof(struct sockaddr_caif) ||
878 !uaddr)
879 goto out;
880
881 memcpy(&cf_sk->conn_req.sockaddr, uaddr,
882 sizeof(struct sockaddr_caif));
883
884 /* Move to connecting socket, start sending Connect Requests */
885 sock->state = SS_CONNECTING;
886 sk->sk_state = CAIF_CONNECTING;
887
888 dbfs_atomic_inc(&cnt.num_connect_req);
889 cf_sk->layer.receive = caif_sktrecv_cb;
890 err = caif_connect_client(&cf_sk->conn_req,
891 &cf_sk->layer);
892 if (err < 0) {
893 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
894 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
895 goto out;
896 }
897
898 err = -EINPROGRESS;
899 wait_connect:
900
901 if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
902 goto out;
903
904 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
905
906 release_sock(sk);
907 err = -ERESTARTSYS;
908 timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
909 sk->sk_state != CAIF_CONNECTING,
910 timeo);
911 lock_sock(sk);
912 if (timeo < 0)
913 goto out; /* -ERESTARTSYS */
914
915 err = -ETIMEDOUT;
916 if (timeo == 0 && sk->sk_state != CAIF_CONNECTED)
917 goto out;
918 if (sk->sk_state != CAIF_CONNECTED) {
919 sock->state = SS_UNCONNECTED;
920 err = sock_error(sk);
921 if (!err)
922 err = -ECONNREFUSED;
923 goto out;
924 }
925 sock->state = SS_CONNECTED;
926 err = 0;
927 out:
928 release_sock(sk);
929 return err;
930 }
931
932 /*
933 * caif_release() - Disconnect a CAIF Socket
934 * Copied and modified af_irda.c:irda_release().
935 */
936 static int caif_release(struct socket *sock)
937 {
938 struct sock *sk = sock->sk;
939 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
940 int res = 0;
941
942 if (!sk)
943 return 0;
944
945 set_tx_flow_off(cf_sk);
946
947 /*
948 * Ensure that packets are not queued after this point in time.
949 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
950 * this ensures no packets when sock is dead.
951 */
952 spin_lock(&sk->sk_receive_queue.lock);
953 sock_set_flag(sk, SOCK_DEAD);
954 spin_unlock(&sk->sk_receive_queue.lock);
955 sock->sk = NULL;
956
957 dbfs_atomic_inc(&cnt.num_disconnect);
958
959 if (cf_sk->debugfs_socket_dir != NULL)
960 debugfs_remove_recursive(cf_sk->debugfs_socket_dir);
961
962 lock_sock(&(cf_sk->sk));
963 sk->sk_state = CAIF_DISCONNECTED;
964 sk->sk_shutdown = SHUTDOWN_MASK;
965
966 if (cf_sk->sk.sk_socket->state == SS_CONNECTED ||
967 cf_sk->sk.sk_socket->state == SS_CONNECTING)
968 res = caif_disconnect_client(&cf_sk->layer);
969
970 cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
971 wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP);
972
973 sock_orphan(sk);
974 cf_sk->layer.dn = NULL;
975 sk_stream_kill_queues(&cf_sk->sk);
976 release_sock(sk);
977 sock_put(sk);
978 return res;
979 }
980
981 /* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */
982 static unsigned int caif_poll(struct file *file,
983 struct socket *sock, poll_table *wait)
984 {
985 struct sock *sk = sock->sk;
986 unsigned int mask;
987 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
988
989 sock_poll_wait(file, sk_sleep(sk), wait);
990 mask = 0;
991
992 /* exceptional events? */
993 if (sk->sk_err)
994 mask |= POLLERR;
995 if (sk->sk_shutdown == SHUTDOWN_MASK)
996 mask |= POLLHUP;
997 if (sk->sk_shutdown & RCV_SHUTDOWN)
998 mask |= POLLRDHUP;
999
1000 /* readable? */
1001 if (!skb_queue_empty(&sk->sk_receive_queue) ||
1002 (sk->sk_shutdown & RCV_SHUTDOWN))
1003 mask |= POLLIN | POLLRDNORM;
1004
1005 /*
1006 * we set writable also when the other side has shut down the
1007 * connection. This prevents stuck sockets.
1008 */
1009 if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
1010 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1011
1012 return mask;
1013 }
1014
1015 static const struct proto_ops caif_seqpacket_ops = {
1016 .family = PF_CAIF,
1017 .owner = THIS_MODULE,
1018 .release = caif_release,
1019 .bind = sock_no_bind,
1020 .connect = caif_connect,
1021 .socketpair = sock_no_socketpair,
1022 .accept = sock_no_accept,
1023 .getname = sock_no_getname,
1024 .poll = caif_poll,
1025 .ioctl = sock_no_ioctl,
1026 .listen = sock_no_listen,
1027 .shutdown = sock_no_shutdown,
1028 .setsockopt = setsockopt,
1029 .getsockopt = sock_no_getsockopt,
1030 .sendmsg = caif_seqpkt_sendmsg,
1031 .recvmsg = caif_seqpkt_recvmsg,
1032 .mmap = sock_no_mmap,
1033 .sendpage = sock_no_sendpage,
1034 };
1035
1036 static const struct proto_ops caif_stream_ops = {
1037 .family = PF_CAIF,
1038 .owner = THIS_MODULE,
1039 .release = caif_release,
1040 .bind = sock_no_bind,
1041 .connect = caif_connect,
1042 .socketpair = sock_no_socketpair,
1043 .accept = sock_no_accept,
1044 .getname = sock_no_getname,
1045 .poll = caif_poll,
1046 .ioctl = sock_no_ioctl,
1047 .listen = sock_no_listen,
1048 .shutdown = sock_no_shutdown,
1049 .setsockopt = setsockopt,
1050 .getsockopt = sock_no_getsockopt,
1051 .sendmsg = caif_stream_sendmsg,
1052 .recvmsg = caif_stream_recvmsg,
1053 .mmap = sock_no_mmap,
1054 .sendpage = sock_no_sendpage,
1055 };
1056
1057 /* This function is called when a socket is finally destroyed. */
1058 static void caif_sock_destructor(struct sock *sk)
1059 {
1060 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1061 caif_assert(!atomic_read(&sk->sk_wmem_alloc));
1062 caif_assert(sk_unhashed(sk));
1063 caif_assert(!sk->sk_socket);
1064 if (!sock_flag(sk, SOCK_DEAD)) {
1065 pr_info("Attempt to release alive CAIF socket: %p\n", sk);
1066 return;
1067 }
1068 sk_stream_kill_queues(&cf_sk->sk);
1069 dbfs_atomic_dec(&cnt.caif_nr_socks);
1070 }
1071
1072 static int caif_create(struct net *net, struct socket *sock, int protocol,
1073 int kern)
1074 {
1075 struct sock *sk = NULL;
1076 struct caifsock *cf_sk = NULL;
1077 static struct proto prot = {.name = "PF_CAIF",
1078 .owner = THIS_MODULE,
1079 .obj_size = sizeof(struct caifsock),
1080 };
1081
1082 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
1083 return -EPERM;
1084 /*
1085 * The sock->type specifies the socket type to use.
1086 * The CAIF socket is a packet stream in the sense
1087 * that it is packet based. CAIF trusts the reliability
1088 * of the link, no resending is implemented.
1089 */
1090 if (sock->type == SOCK_SEQPACKET)
1091 sock->ops = &caif_seqpacket_ops;
1092 else if (sock->type == SOCK_STREAM)
1093 sock->ops = &caif_stream_ops;
1094 else
1095 return -ESOCKTNOSUPPORT;
1096
1097 if (protocol < 0 || protocol >= CAIFPROTO_MAX)
1098 return -EPROTONOSUPPORT;
1099 /*
1100 * Set the socket state to unconnected. The socket state
1101 * is really not used at all in the net/core or socket.c but the
1102 * initialization makes sure that sock->state is not uninitialized.
1103 */
1104 sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot);
1105 if (!sk)
1106 return -ENOMEM;
1107
1108 cf_sk = container_of(sk, struct caifsock, sk);
1109
1110 /* Store the protocol */
1111 sk->sk_protocol = (unsigned char) protocol;
1112
1113 /* Sendbuf dictates the amount of outbound packets not yet sent */
1114 sk->sk_sndbuf = CAIF_DEF_SNDBUF;
1115 sk->sk_rcvbuf = CAIF_DEF_RCVBUF;
1116
1117 /*
1118 * Lock in order to try to stop someone from opening the socket
1119 * too early.
1120 */
1121 lock_sock(&(cf_sk->sk));
1122
1123 /* Initialize the nozero default sock structure data. */
1124 sock_init_data(sock, sk);
1125 sk->sk_destruct = caif_sock_destructor;
1126
1127 mutex_init(&cf_sk->readlock); /* single task reading lock */
1128 cf_sk->layer.ctrlcmd = caif_ctrl_cb;
1129 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
1130 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
1131
1132 set_tx_flow_off(cf_sk);
1133 set_rx_flow_on(cf_sk);
1134
1135 /* Set default options on configuration */
1136 cf_sk->conn_req.priority = CAIF_PRIO_NORMAL;
1137 cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1138 cf_sk->conn_req.protocol = protocol;
1139 /* Increase the number of sockets created. */
1140 dbfs_atomic_inc(&cnt.caif_nr_socks);
1141 #ifdef CONFIG_DEBUG_FS
1142 if (!IS_ERR(debugfsdir)) {
1143 /* Fill in some information concerning the misc socket. */
1144 snprintf(cf_sk->name, sizeof(cf_sk->name), "cfsk%d",
1145 atomic_read(&cnt.caif_nr_socks));
1146
1147 cf_sk->debugfs_socket_dir =
1148 debugfs_create_dir(cf_sk->name, debugfsdir);
1149 debugfs_create_u32("sk_state", S_IRUSR | S_IWUSR,
1150 cf_sk->debugfs_socket_dir,
1151 (u32 *) &cf_sk->sk.sk_state);
1152 debugfs_create_u32("flow_state", S_IRUSR | S_IWUSR,
1153 cf_sk->debugfs_socket_dir, &cf_sk->flow_state);
1154 debugfs_create_u32("sk_rmem_alloc", S_IRUSR | S_IWUSR,
1155 cf_sk->debugfs_socket_dir,
1156 (u32 *) &cf_sk->sk.sk_rmem_alloc);
1157 debugfs_create_u32("sk_wmem_alloc", S_IRUSR | S_IWUSR,
1158 cf_sk->debugfs_socket_dir,
1159 (u32 *) &cf_sk->sk.sk_wmem_alloc);
1160 debugfs_create_u32("identity", S_IRUSR | S_IWUSR,
1161 cf_sk->debugfs_socket_dir,
1162 (u32 *) &cf_sk->layer.id);
1163 }
1164 #endif
1165 release_sock(&cf_sk->sk);
1166 return 0;
1167 }
1168
1169
1170 static struct net_proto_family caif_family_ops = {
1171 .family = PF_CAIF,
1172 .create = caif_create,
1173 .owner = THIS_MODULE,
1174 };
1175
1176 static int af_caif_init(void)
1177 {
1178 int err = sock_register(&caif_family_ops);
1179 if (!err)
1180 return err;
1181 return 0;
1182 }
1183
1184 static int __init caif_sktinit_module(void)
1185 {
1186 #ifdef CONFIG_DEBUG_FS
1187 debugfsdir = debugfs_create_dir("caif_sk", NULL);
1188 if (!IS_ERR(debugfsdir)) {
1189 debugfs_create_u32("num_sockets", S_IRUSR | S_IWUSR,
1190 debugfsdir,
1191 (u32 *) &cnt.caif_nr_socks);
1192 debugfs_create_u32("num_connect_req", S_IRUSR | S_IWUSR,
1193 debugfsdir,
1194 (u32 *) &cnt.num_connect_req);
1195 debugfs_create_u32("num_connect_resp", S_IRUSR | S_IWUSR,
1196 debugfsdir,
1197 (u32 *) &cnt.num_connect_resp);
1198 debugfs_create_u32("num_connect_fail_resp", S_IRUSR | S_IWUSR,
1199 debugfsdir,
1200 (u32 *) &cnt.num_connect_fail_resp);
1201 debugfs_create_u32("num_disconnect", S_IRUSR | S_IWUSR,
1202 debugfsdir,
1203 (u32 *) &cnt.num_disconnect);
1204 debugfs_create_u32("num_remote_shutdown_ind",
1205 S_IRUSR | S_IWUSR, debugfsdir,
1206 (u32 *) &cnt.num_remote_shutdown_ind);
1207 debugfs_create_u32("num_tx_flow_off_ind", S_IRUSR | S_IWUSR,
1208 debugfsdir,
1209 (u32 *) &cnt.num_tx_flow_off_ind);
1210 debugfs_create_u32("num_tx_flow_on_ind", S_IRUSR | S_IWUSR,
1211 debugfsdir,
1212 (u32 *) &cnt.num_tx_flow_on_ind);
1213 debugfs_create_u32("num_rx_flow_off", S_IRUSR | S_IWUSR,
1214 debugfsdir,
1215 (u32 *) &cnt.num_rx_flow_off);
1216 debugfs_create_u32("num_rx_flow_on", S_IRUSR | S_IWUSR,
1217 debugfsdir,
1218 (u32 *) &cnt.num_rx_flow_on);
1219 }
1220 #endif
1221 return af_caif_init();
1222 }
1223
1224 static void __exit caif_sktexit_module(void)
1225 {
1226 sock_unregister(PF_CAIF);
1227 if (debugfsdir != NULL)
1228 debugfs_remove_recursive(debugfsdir);
1229 }
1230 module_init(caif_sktinit_module);
1231 module_exit(caif_sktexit_module);
Linux with added FPC-III support