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1 | /* |
2 | * Copyright (C) ST-Ericsson AB 2010 |
3 | * Author: Sjur Brendeland |
4 | * License terms: GNU General Public License (GPL) version 2 |
5 | */ |
6 | |
7 | #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__ |
8 | |
9 | #include <linux/fs.h> |
10 | #include <linux/init.h> |
11 | #include <linux/module.h> |
12 | #include <linux/sched.h> |
13 | #include <linux/spinlock.h> |
14 | #include <linux/mutex.h> |
15 | #include <linux/list.h> |
16 | #include <linux/wait.h> |
17 | #include <linux/poll.h> |
18 | #include <linux/tcp.h> |
19 | #include <linux/uaccess.h> |
20 | #include <linux/debugfs.h> |
21 | #include <linux/caif/caif_socket.h> |
22 | #include <linux/pkt_sched.h> |
23 | #include <net/sock.h> |
24 | #include <net/tcp_states.h> |
25 | #include <net/caif/caif_layer.h> |
26 | #include <net/caif/caif_dev.h> |
27 | #include <net/caif/cfpkt.h> |
28 | |
29 | MODULE_LICENSE("GPL"); |
30 | MODULE_ALIAS_NETPROTO(AF_CAIF); |
31 | |
32 | /* |
33 | * CAIF state is re-using the TCP socket states. |
34 | * caif_states stored in sk_state reflect the state as reported by |
35 | * the CAIF stack, while sk_socket->state is the state of the socket. |
36 | */ |
37 | enum caif_states { |
38 | CAIF_CONNECTED = TCP_ESTABLISHED, |
39 | CAIF_CONNECTING = TCP_SYN_SENT, |
40 | CAIF_DISCONNECTED = TCP_CLOSE |
41 | }; |
42 | |
43 | #define TX_FLOW_ON_BIT 1 |
44 | #define RX_FLOW_ON_BIT 2 |
45 | |
46 | struct caifsock { |
47 | struct sock sk; /* must be first member */ |
48 | struct cflayer layer; |
49 | u32 flow_state; |
50 | struct caif_connect_request conn_req; |
51 | struct mutex readlock; |
52 | struct dentry *debugfs_socket_dir; |
53 | int headroom, tailroom, maxframe; |
54 | }; |
55 | |
56 | static int rx_flow_is_on(struct caifsock *cf_sk) |
57 | { |
58 | return test_bit(RX_FLOW_ON_BIT, |
59 | (void *) &cf_sk->flow_state); |
60 | } |
61 | |
62 | static int tx_flow_is_on(struct caifsock *cf_sk) |
63 | { |
64 | return test_bit(TX_FLOW_ON_BIT, |
65 | (void *) &cf_sk->flow_state); |
66 | } |
67 | |
68 | static void set_rx_flow_off(struct caifsock *cf_sk) |
69 | { |
70 | clear_bit(RX_FLOW_ON_BIT, |
71 | (void *) &cf_sk->flow_state); |
72 | } |
73 | |
74 | static void set_rx_flow_on(struct caifsock *cf_sk) |
75 | { |
76 | set_bit(RX_FLOW_ON_BIT, |
77 | (void *) &cf_sk->flow_state); |
78 | } |
79 | |
80 | static void set_tx_flow_off(struct caifsock *cf_sk) |
81 | { |
82 | clear_bit(TX_FLOW_ON_BIT, |
83 | (void *) &cf_sk->flow_state); |
84 | } |
85 | |
86 | static void set_tx_flow_on(struct caifsock *cf_sk) |
87 | { |
88 | set_bit(TX_FLOW_ON_BIT, |
89 | (void *) &cf_sk->flow_state); |
90 | } |
91 | |
92 | static void caif_read_lock(struct sock *sk) |
93 | { |
94 | struct caifsock *cf_sk; |
95 | cf_sk = container_of(sk, struct caifsock, sk); |
96 | mutex_lock(&cf_sk->readlock); |
97 | } |
98 | |
99 | static void caif_read_unlock(struct sock *sk) |
100 | { |
101 | struct caifsock *cf_sk; |
102 | cf_sk = container_of(sk, struct caifsock, sk); |
103 | mutex_unlock(&cf_sk->readlock); |
104 | } |
105 | |
106 | static int sk_rcvbuf_lowwater(struct caifsock *cf_sk) |
107 | { |
108 | /* A quarter of full buffer is used a low water mark */ |
109 | return cf_sk->sk.sk_rcvbuf / 4; |
110 | } |
111 | |
112 | static void caif_flow_ctrl(struct sock *sk, int mode) |
113 | { |
114 | struct caifsock *cf_sk; |
115 | cf_sk = container_of(sk, struct caifsock, sk); |
116 | if (cf_sk->layer.dn && cf_sk->layer.dn->modemcmd) |
117 | cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, mode); |
118 | } |
119 | |
120 | /* |
121 | * Copied from sock.c:sock_queue_rcv_skb(), but changed so packets are |
122 | * not dropped, but CAIF is sending flow off instead. |
123 | */ |
124 | static int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) |
125 | { |
126 | int err; |
127 | unsigned long flags; |
128 | struct sk_buff_head *list = &sk->sk_receive_queue; |
129 | struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); |
130 | |
131 | if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= |
132 | (unsigned int)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) { |
133 | net_dbg_ratelimited("sending flow OFF (queue len = %d %d)\n", |
134 | atomic_read(&cf_sk->sk.sk_rmem_alloc), |
135 | sk_rcvbuf_lowwater(cf_sk)); |
136 | set_rx_flow_off(cf_sk); |
137 | caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ); |
138 | } |
139 | |
140 | err = sk_filter(sk, skb); |
141 | if (err) |
142 | return err; |
143 | if (!sk_rmem_schedule(sk, skb, skb->truesize) && rx_flow_is_on(cf_sk)) { |
144 | set_rx_flow_off(cf_sk); |
145 | net_dbg_ratelimited("sending flow OFF due to rmem_schedule\n"); |
146 | caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ); |
147 | } |
148 | skb->dev = NULL; |
149 | skb_set_owner_r(skb, sk); |
150 | /* Cache the SKB length before we tack it onto the receive |
151 | * queue. Once it is added it no longer belongs to us and |
152 | * may be freed by other threads of control pulling packets |
153 | * from the queue. |
154 | */ |
155 | spin_lock_irqsave(&list->lock, flags); |
156 | if (!sock_flag(sk, SOCK_DEAD)) |
157 | __skb_queue_tail(list, skb); |
158 | spin_unlock_irqrestore(&list->lock, flags); |
159 | |
160 | if (!sock_flag(sk, SOCK_DEAD)) |
161 | sk->sk_data_ready(sk); |
162 | else |
163 | kfree_skb(skb); |
164 | return 0; |
165 | } |
166 | |
167 | /* Packet Receive Callback function called from CAIF Stack */ |
168 | static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt) |
169 | { |
170 | struct caifsock *cf_sk; |
171 | struct sk_buff *skb; |
172 | |
173 | cf_sk = container_of(layr, struct caifsock, layer); |
174 | skb = cfpkt_tonative(pkt); |
175 | |
176 | if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) { |
177 | kfree_skb(skb); |
178 | return 0; |
179 | } |
180 | caif_queue_rcv_skb(&cf_sk->sk, skb); |
181 | return 0; |
182 | } |
183 | |
184 | static void cfsk_hold(struct cflayer *layr) |
185 | { |
186 | struct caifsock *cf_sk = container_of(layr, struct caifsock, layer); |
187 | sock_hold(&cf_sk->sk); |
188 | } |
189 | |
190 | static void cfsk_put(struct cflayer *layr) |
191 | { |
192 | struct caifsock *cf_sk = container_of(layr, struct caifsock, layer); |
193 | sock_put(&cf_sk->sk); |
194 | } |
195 | |
196 | /* Packet Control Callback function called from CAIF */ |
197 | static void caif_ctrl_cb(struct cflayer *layr, |
198 | enum caif_ctrlcmd flow, |
199 | int phyid) |
200 | { |
201 | struct caifsock *cf_sk = container_of(layr, struct caifsock, layer); |
202 | switch (flow) { |
203 | case CAIF_CTRLCMD_FLOW_ON_IND: |
204 | /* OK from modem to start sending again */ |
205 | set_tx_flow_on(cf_sk); |
206 | cf_sk->sk.sk_state_change(&cf_sk->sk); |
207 | break; |
208 | |
209 | case CAIF_CTRLCMD_FLOW_OFF_IND: |
210 | /* Modem asks us to shut up */ |
211 | set_tx_flow_off(cf_sk); |
212 | cf_sk->sk.sk_state_change(&cf_sk->sk); |
213 | break; |
214 | |
215 | case CAIF_CTRLCMD_INIT_RSP: |
216 | /* We're now connected */ |
217 | caif_client_register_refcnt(&cf_sk->layer, |
218 | cfsk_hold, cfsk_put); |
219 | cf_sk->sk.sk_state = CAIF_CONNECTED; |
220 | set_tx_flow_on(cf_sk); |
221 | cf_sk->sk.sk_shutdown = 0; |
222 | cf_sk->sk.sk_state_change(&cf_sk->sk); |
223 | break; |
224 | |
225 | case CAIF_CTRLCMD_DEINIT_RSP: |
226 | /* We're now disconnected */ |
227 | cf_sk->sk.sk_state = CAIF_DISCONNECTED; |
228 | cf_sk->sk.sk_state_change(&cf_sk->sk); |
229 | break; |
230 | |
231 | case CAIF_CTRLCMD_INIT_FAIL_RSP: |
232 | /* Connect request failed */ |
233 | cf_sk->sk.sk_err = ECONNREFUSED; |
234 | cf_sk->sk.sk_state = CAIF_DISCONNECTED; |
235 | cf_sk->sk.sk_shutdown = SHUTDOWN_MASK; |
236 | /* |
237 | * Socket "standards" seems to require POLLOUT to |
238 | * be set at connect failure. |
239 | */ |
240 | set_tx_flow_on(cf_sk); |
241 | cf_sk->sk.sk_state_change(&cf_sk->sk); |
242 | break; |
243 | |
244 | case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND: |
245 | /* Modem has closed this connection, or device is down. */ |
246 | cf_sk->sk.sk_shutdown = SHUTDOWN_MASK; |
247 | cf_sk->sk.sk_err = ECONNRESET; |
248 | set_rx_flow_on(cf_sk); |
249 | cf_sk->sk.sk_error_report(&cf_sk->sk); |
250 | break; |
251 | |
252 | default: |
253 | pr_debug("Unexpected flow command %d\n", flow); |
254 | } |
255 | } |
256 | |
257 | static void caif_check_flow_release(struct sock *sk) |
258 | { |
259 | struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); |
260 | |
261 | if (rx_flow_is_on(cf_sk)) |
262 | return; |
263 | |
264 | if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) { |
265 | set_rx_flow_on(cf_sk); |
266 | caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ); |
267 | } |
268 | } |
269 | |
270 | /* |
271 | * Copied from unix_dgram_recvmsg, but removed credit checks, |
272 | * changed locking, address handling and added MSG_TRUNC. |
273 | */ |
274 | static int caif_seqpkt_recvmsg(struct kiocb *iocb, struct socket *sock, |
275 | struct msghdr *m, size_t len, int flags) |
276 | |
277 | { |
278 | struct sock *sk = sock->sk; |
279 | struct sk_buff *skb; |
280 | int ret; |
281 | int copylen; |
282 | |
283 | ret = -EOPNOTSUPP; |
284 | if (m->msg_flags&MSG_OOB) |
285 | goto read_error; |
286 | |
287 | skb = skb_recv_datagram(sk, flags, 0 , &ret); |
288 | if (!skb) |
289 | goto read_error; |
290 | copylen = skb->len; |
291 | if (len < copylen) { |
292 | m->msg_flags |= MSG_TRUNC; |
293 | copylen = len; |
294 | } |
295 | |
296 | ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, copylen); |
297 | if (ret) |
298 | goto out_free; |
299 | |
300 | ret = (flags & MSG_TRUNC) ? skb->len : copylen; |
301 | out_free: |
302 | skb_free_datagram(sk, skb); |
303 | caif_check_flow_release(sk); |
304 | return ret; |
305 | |
306 | read_error: |
307 | return ret; |
308 | } |
309 | |
310 | |
311 | /* Copied from unix_stream_wait_data, identical except for lock call. */ |
312 | static long caif_stream_data_wait(struct sock *sk, long timeo) |
313 | { |
314 | DEFINE_WAIT(wait); |
315 | lock_sock(sk); |
316 | |
317 | for (;;) { |
318 | prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); |
319 | |
320 | if (!skb_queue_empty(&sk->sk_receive_queue) || |
321 | sk->sk_err || |
322 | sk->sk_state != CAIF_CONNECTED || |
323 | sock_flag(sk, SOCK_DEAD) || |
324 | (sk->sk_shutdown & RCV_SHUTDOWN) || |
325 | signal_pending(current) || |
326 | !timeo) |
327 | break; |
328 | |
329 | set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); |
330 | release_sock(sk); |
331 | timeo = schedule_timeout(timeo); |
332 | lock_sock(sk); |
333 | clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); |
334 | } |
335 | |
336 | finish_wait(sk_sleep(sk), &wait); |
337 | release_sock(sk); |
338 | return timeo; |
339 | } |
340 | |
341 | |
342 | /* |
343 | * Copied from unix_stream_recvmsg, but removed credit checks, |
344 | * changed locking calls, changed address handling. |
345 | */ |
346 | static int caif_stream_recvmsg(struct kiocb *iocb, struct socket *sock, |
347 | struct msghdr *msg, size_t size, |
348 | int flags) |
349 | { |
350 | struct sock *sk = sock->sk; |
351 | int copied = 0; |
352 | int target; |
353 | int err = 0; |
354 | long timeo; |
355 | |
356 | err = -EOPNOTSUPP; |
357 | if (flags&MSG_OOB) |
358 | goto out; |
359 | |
360 | /* |
361 | * Lock the socket to prevent queue disordering |
362 | * while sleeps in memcpy_tomsg |
363 | */ |
364 | err = -EAGAIN; |
365 | if (sk->sk_state == CAIF_CONNECTING) |
366 | goto out; |
367 | |
368 | caif_read_lock(sk); |
369 | target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); |
370 | timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); |
371 | |
372 | do { |
373 | int chunk; |
374 | struct sk_buff *skb; |
375 | |
376 | lock_sock(sk); |
377 | 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; |
415 | unlock: |
416 | release_sock(sk); |
417 | break; |
418 | } |
419 | release_sock(sk); |
420 | chunk = min_t(unsigned int, skb->len, size); |
421 | if (memcpy_toiovec(msg->msg_iov, 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 | |
452 | out: |
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 | */ |
460 | static 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 | */ |
496 | static 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 */ |
514 | static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock, |
515 | struct msghdr *msg, 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 | ret = -EINVAL; |
538 | if (unlikely(msg->msg_iov->iov_base == NULL)) |
539 | goto err; |
540 | noblock = msg->msg_flags & MSG_DONTWAIT; |
541 | |
542 | timeo = sock_sndtimeo(sk, noblock); |
543 | timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk), |
544 | 1, timeo, &ret); |
545 | |
546 | if (ret) |
547 | goto err; |
548 | ret = -EPIPE; |
549 | if (cf_sk->sk.sk_state != CAIF_CONNECTED || |
550 | sock_flag(sk, SOCK_DEAD) || |
551 | (sk->sk_shutdown & RCV_SHUTDOWN)) |
552 | goto err; |
553 | |
554 | /* Error if trying to write more than maximum frame size. */ |
555 | ret = -EMSGSIZE; |
556 | if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM) |
557 | goto err; |
558 | |
559 | buffer_size = len + cf_sk->headroom + cf_sk->tailroom; |
560 | |
561 | ret = -ENOMEM; |
562 | skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret); |
563 | |
564 | if (!skb || skb_tailroom(skb) < buffer_size) |
565 | goto err; |
566 | |
567 | skb_reserve(skb, cf_sk->headroom); |
568 | |
569 | ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); |
570 | |
571 | if (ret) |
572 | goto err; |
573 | ret = transmit_skb(skb, cf_sk, noblock, timeo); |
574 | if (ret < 0) |
575 | /* skb is already freed */ |
576 | return ret; |
577 | |
578 | return len; |
579 | err: |
580 | kfree_skb(skb); |
581 | return ret; |
582 | } |
583 | |
584 | /* |
585 | * Copied from unix_stream_sendmsg and adapted to CAIF: |
586 | * Changed removed permission handling and added waiting for flow on |
587 | * and other minor adaptations. |
588 | */ |
589 | static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, |
590 | struct msghdr *msg, size_t len) |
591 | { |
592 | struct sock *sk = sock->sk; |
593 | struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); |
594 | int err, size; |
595 | struct sk_buff *skb; |
596 | int sent = 0; |
597 | long timeo; |
598 | |
599 | err = -EOPNOTSUPP; |
600 | if (unlikely(msg->msg_flags&MSG_OOB)) |
601 | goto out_err; |
602 | |
603 | if (unlikely(msg->msg_namelen)) |
604 | goto out_err; |
605 | |
606 | timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); |
607 | timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err); |
608 | |
609 | if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN)) |
610 | goto pipe_err; |
611 | |
612 | while (sent < len) { |
613 | |
614 | size = len-sent; |
615 | |
616 | if (size > cf_sk->maxframe) |
617 | size = cf_sk->maxframe; |
618 | |
619 | /* If size is more than half of sndbuf, chop up message */ |
620 | if (size > ((sk->sk_sndbuf >> 1) - 64)) |
621 | size = (sk->sk_sndbuf >> 1) - 64; |
622 | |
623 | if (size > SKB_MAX_ALLOC) |
624 | size = SKB_MAX_ALLOC; |
625 | |
626 | skb = sock_alloc_send_skb(sk, |
627 | size + cf_sk->headroom + |
628 | cf_sk->tailroom, |
629 | msg->msg_flags&MSG_DONTWAIT, |
630 | &err); |
631 | if (skb == NULL) |
632 | goto out_err; |
633 | |
634 | skb_reserve(skb, cf_sk->headroom); |
635 | /* |
636 | * If you pass two values to the sock_alloc_send_skb |
637 | * it tries to grab the large buffer with GFP_NOFS |
638 | * (which can fail easily), and if it fails grab the |
639 | * fallback size buffer which is under a page and will |
640 | * succeed. [Alan] |
641 | */ |
642 | size = min_t(int, size, skb_tailroom(skb)); |
643 | |
644 | err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); |
645 | if (err) { |
646 | kfree_skb(skb); |
647 | goto out_err; |
648 | } |
649 | err = transmit_skb(skb, cf_sk, |
650 | msg->msg_flags&MSG_DONTWAIT, timeo); |
651 | if (err < 0) |
652 | /* skb is already freed */ |
653 | goto pipe_err; |
654 | |
655 | sent += size; |
656 | } |
657 | |
658 | return sent; |
659 | |
660 | pipe_err: |
661 | if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) |
662 | send_sig(SIGPIPE, current, 0); |
663 | err = -EPIPE; |
664 | out_err: |
665 | return sent ? : err; |
666 | } |
667 | |
668 | static int setsockopt(struct socket *sock, |
669 | int lvl, int opt, char __user *ov, unsigned int ol) |
670 | { |
671 | struct sock *sk = sock->sk; |
672 | struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); |
673 | int linksel; |
674 | |
675 | if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED) |
676 | return -ENOPROTOOPT; |
677 | |
678 | switch (opt) { |
679 | case CAIFSO_LINK_SELECT: |
680 | if (ol < sizeof(int)) |
681 | return -EINVAL; |
682 | if (lvl != SOL_CAIF) |
683 | goto bad_sol; |
684 | if (copy_from_user(&linksel, ov, sizeof(int))) |
685 | return -EINVAL; |
686 | lock_sock(&(cf_sk->sk)); |
687 | cf_sk->conn_req.link_selector = linksel; |
688 | release_sock(&cf_sk->sk); |
689 | return 0; |
690 | |
691 | case CAIFSO_REQ_PARAM: |
692 | if (lvl != SOL_CAIF) |
693 | goto bad_sol; |
694 | if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL) |
695 | return -ENOPROTOOPT; |
696 | lock_sock(&(cf_sk->sk)); |
697 | if (ol > sizeof(cf_sk->conn_req.param.data) || |
698 | copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) { |
699 | release_sock(&cf_sk->sk); |
700 | return -EINVAL; |
701 | } |
702 | cf_sk->conn_req.param.size = ol; |
703 | release_sock(&cf_sk->sk); |
704 | return 0; |
705 | |
706 | default: |
707 | return -ENOPROTOOPT; |
708 | } |
709 | |
710 | return 0; |
711 | bad_sol: |
712 | return -ENOPROTOOPT; |
713 | |
714 | } |
715 | |
716 | /* |
717 | * caif_connect() - Connect a CAIF Socket |
718 | * Copied and modified af_irda.c:irda_connect(). |
719 | * |
720 | * Note : by consulting "errno", the user space caller may learn the cause |
721 | * of the failure. Most of them are visible in the function, others may come |
722 | * from subroutines called and are listed here : |
723 | * o -EAFNOSUPPORT: bad socket family or type. |
724 | * o -ESOCKTNOSUPPORT: bad socket type or protocol |
725 | * o -EINVAL: bad socket address, or CAIF link type |
726 | * o -ECONNREFUSED: remote end refused the connection. |
727 | * o -EINPROGRESS: connect request sent but timed out (or non-blocking) |
728 | * o -EISCONN: already connected. |
729 | * o -ETIMEDOUT: Connection timed out (send timeout) |
730 | * o -ENODEV: No link layer to send request |
731 | * o -ECONNRESET: Received Shutdown indication or lost link layer |
732 | * o -ENOMEM: Out of memory |
733 | * |
734 | * State Strategy: |
735 | * o sk_state: holds the CAIF_* protocol state, it's updated by |
736 | * caif_ctrl_cb. |
737 | * o sock->state: holds the SS_* socket state and is updated by connect and |
738 | * disconnect. |
739 | */ |
740 | static int caif_connect(struct socket *sock, struct sockaddr *uaddr, |
741 | int addr_len, int flags) |
742 | { |
743 | struct sock *sk = sock->sk; |
744 | struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); |
745 | long timeo; |
746 | int err; |
747 | int ifindex, headroom, tailroom; |
748 | unsigned int mtu; |
749 | struct net_device *dev; |
750 | |
751 | lock_sock(sk); |
752 | |
753 | err = -EAFNOSUPPORT; |
754 | if (uaddr->sa_family != AF_CAIF) |
755 | goto out; |
756 | |
757 | switch (sock->state) { |
758 | case SS_UNCONNECTED: |
759 | /* Normal case, a fresh connect */ |
760 | caif_assert(sk->sk_state == CAIF_DISCONNECTED); |
761 | break; |
762 | case SS_CONNECTING: |
763 | switch (sk->sk_state) { |
764 | case CAIF_CONNECTED: |
765 | sock->state = SS_CONNECTED; |
766 | err = -EISCONN; |
767 | goto out; |
768 | case CAIF_DISCONNECTED: |
769 | /* Reconnect allowed */ |
770 | break; |
771 | case CAIF_CONNECTING: |
772 | err = -EALREADY; |
773 | if (flags & O_NONBLOCK) |
774 | goto out; |
775 | goto wait_connect; |
776 | } |
777 | break; |
778 | case SS_CONNECTED: |
779 | caif_assert(sk->sk_state == CAIF_CONNECTED || |
780 | sk->sk_state == CAIF_DISCONNECTED); |
781 | if (sk->sk_shutdown & SHUTDOWN_MASK) { |
782 | /* Allow re-connect after SHUTDOWN_IND */ |
783 | caif_disconnect_client(sock_net(sk), &cf_sk->layer); |
784 | caif_free_client(&cf_sk->layer); |
785 | break; |
786 | } |
787 | /* No reconnect on a seqpacket socket */ |
788 | err = -EISCONN; |
789 | goto out; |
790 | case SS_DISCONNECTING: |
791 | case SS_FREE: |
792 | caif_assert(1); /*Should never happen */ |
793 | break; |
794 | } |
795 | sk->sk_state = CAIF_DISCONNECTED; |
796 | sock->state = SS_UNCONNECTED; |
797 | sk_stream_kill_queues(&cf_sk->sk); |
798 | |
799 | err = -EINVAL; |
800 | if (addr_len != sizeof(struct sockaddr_caif)) |
801 | goto out; |
802 | |
803 | memcpy(&cf_sk->conn_req.sockaddr, uaddr, |
804 | sizeof(struct sockaddr_caif)); |
805 | |
806 | /* Move to connecting socket, start sending Connect Requests */ |
807 | sock->state = SS_CONNECTING; |
808 | sk->sk_state = CAIF_CONNECTING; |
809 | |
810 | /* Check priority value comming from socket */ |
811 | /* if priority value is out of range it will be ajusted */ |
812 | if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX) |
813 | cf_sk->conn_req.priority = CAIF_PRIO_MAX; |
814 | else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN) |
815 | cf_sk->conn_req.priority = CAIF_PRIO_MIN; |
816 | else |
817 | cf_sk->conn_req.priority = cf_sk->sk.sk_priority; |
818 | |
819 | /*ifindex = id of the interface.*/ |
820 | cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if; |
821 | |
822 | cf_sk->layer.receive = caif_sktrecv_cb; |
823 | |
824 | err = caif_connect_client(sock_net(sk), &cf_sk->conn_req, |
825 | &cf_sk->layer, &ifindex, &headroom, &tailroom); |
826 | |
827 | if (err < 0) { |
828 | cf_sk->sk.sk_socket->state = SS_UNCONNECTED; |
829 | cf_sk->sk.sk_state = CAIF_DISCONNECTED; |
830 | goto out; |
831 | } |
832 | |
833 | err = -ENODEV; |
834 | rcu_read_lock(); |
835 | dev = dev_get_by_index_rcu(sock_net(sk), ifindex); |
836 | if (!dev) { |
837 | rcu_read_unlock(); |
838 | goto out; |
839 | } |
840 | cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom); |
841 | mtu = dev->mtu; |
842 | rcu_read_unlock(); |
843 | |
844 | cf_sk->tailroom = tailroom; |
845 | cf_sk->maxframe = mtu - (headroom + tailroom); |
846 | if (cf_sk->maxframe < 1) { |
847 | pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu); |
848 | err = -ENODEV; |
849 | goto out; |
850 | } |
851 | |
852 | err = -EINPROGRESS; |
853 | wait_connect: |
854 | |
855 | if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK)) |
856 | goto out; |
857 | |
858 | timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); |
859 | |
860 | release_sock(sk); |
861 | err = -ERESTARTSYS; |
862 | timeo = wait_event_interruptible_timeout(*sk_sleep(sk), |
863 | sk->sk_state != CAIF_CONNECTING, |
864 | timeo); |
865 | lock_sock(sk); |
866 | if (timeo < 0) |
867 | goto out; /* -ERESTARTSYS */ |
868 | |
869 | err = -ETIMEDOUT; |
870 | if (timeo == 0 && sk->sk_state != CAIF_CONNECTED) |
871 | goto out; |
872 | if (sk->sk_state != CAIF_CONNECTED) { |
873 | sock->state = SS_UNCONNECTED; |
874 | err = sock_error(sk); |
875 | if (!err) |
876 | err = -ECONNREFUSED; |
877 | goto out; |
878 | } |
879 | sock->state = SS_CONNECTED; |
880 | err = 0; |
881 | out: |
882 | release_sock(sk); |
883 | return err; |
884 | } |
885 | |
886 | /* |
887 | * caif_release() - Disconnect a CAIF Socket |
888 | * Copied and modified af_irda.c:irda_release(). |
889 | */ |
890 | static int caif_release(struct socket *sock) |
891 | { |
892 | struct sock *sk = sock->sk; |
893 | struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); |
894 | |
895 | if (!sk) |
896 | return 0; |
897 | |
898 | set_tx_flow_off(cf_sk); |
899 | |
900 | /* |
901 | * Ensure that packets are not queued after this point in time. |
902 | * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock, |
903 | * this ensures no packets when sock is dead. |
904 | */ |
905 | spin_lock_bh(&sk->sk_receive_queue.lock); |
906 | sock_set_flag(sk, SOCK_DEAD); |
907 | spin_unlock_bh(&sk->sk_receive_queue.lock); |
908 | sock->sk = NULL; |
909 | |
910 | WARN_ON(IS_ERR(cf_sk->debugfs_socket_dir)); |
911 | if (cf_sk->debugfs_socket_dir != NULL) |
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), POLLERR|POLLHUP); |
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 */ |
930 | static unsigned int caif_poll(struct file *file, |
931 | struct socket *sock, poll_table *wait) |
932 | { |
933 | struct sock *sk = sock->sk; |
934 | unsigned int mask; |
935 | struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); |
936 | |
937 | sock_poll_wait(file, sk_sleep(sk), wait); |
938 | mask = 0; |
939 | |
940 | /* exceptional events? */ |
941 | if (sk->sk_err) |
942 | mask |= POLLERR; |
943 | if (sk->sk_shutdown == SHUTDOWN_MASK) |
944 | mask |= POLLHUP; |
945 | if (sk->sk_shutdown & RCV_SHUTDOWN) |
946 | mask |= POLLRDHUP; |
947 | |
948 | /* readable? */ |
949 | if (!skb_queue_empty(&sk->sk_receive_queue) || |
950 | (sk->sk_shutdown & RCV_SHUTDOWN)) |
951 | mask |= POLLIN | POLLRDNORM; |
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 |= POLLOUT | POLLWRNORM | POLLWRBAND; |
959 | |
960 | return mask; |
961 | } |
962 | |
963 | static 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 | .getsockopt = sock_no_getsockopt, |
978 | .sendmsg = caif_seqpkt_sendmsg, |
979 | .recvmsg = caif_seqpkt_recvmsg, |
980 | .mmap = sock_no_mmap, |
981 | .sendpage = sock_no_sendpage, |
982 | }; |
983 | |
984 | static const struct proto_ops caif_stream_ops = { |
985 | .family = PF_CAIF, |
986 | .owner = THIS_MODULE, |
987 | .release = caif_release, |
988 | .bind = sock_no_bind, |
989 | .connect = caif_connect, |
990 | .socketpair = sock_no_socketpair, |
991 | .accept = sock_no_accept, |
992 | .getname = sock_no_getname, |
993 | .poll = caif_poll, |
994 | .ioctl = sock_no_ioctl, |
995 | .listen = sock_no_listen, |
996 | .shutdown = sock_no_shutdown, |
997 | .setsockopt = setsockopt, |
998 | .getsockopt = sock_no_getsockopt, |
999 | .sendmsg = caif_stream_sendmsg, |
1000 | .recvmsg = caif_stream_recvmsg, |
1001 | .mmap = sock_no_mmap, |
1002 | .sendpage = sock_no_sendpage, |
1003 | }; |
1004 | |
1005 | /* This function is called when a socket is finally destroyed. */ |
1006 | static void caif_sock_destructor(struct sock *sk) |
1007 | { |
1008 | struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); |
1009 | caif_assert(!atomic_read(&sk->sk_wmem_alloc)); |
1010 | caif_assert(sk_unhashed(sk)); |
1011 | caif_assert(!sk->sk_socket); |
1012 | if (!sock_flag(sk, SOCK_DEAD)) { |
1013 | pr_debug("Attempt to release alive CAIF socket: %p\n", sk); |
1014 | return; |
1015 | } |
1016 | sk_stream_kill_queues(&cf_sk->sk); |
1017 | caif_free_client(&cf_sk->layer); |
1018 | } |
1019 | |
1020 | static int caif_create(struct net *net, struct socket *sock, int protocol, |
1021 | int kern) |
1022 | { |
1023 | struct sock *sk = NULL; |
1024 | struct caifsock *cf_sk = NULL; |
1025 | static struct proto prot = {.name = "PF_CAIF", |
1026 | .owner = THIS_MODULE, |
1027 | .obj_size = sizeof(struct caifsock), |
1028 | }; |
1029 | |
1030 | if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN)) |
1031 | return -EPERM; |
1032 | /* |
1033 | * The sock->type specifies the socket type to use. |
1034 | * The CAIF socket is a packet stream in the sense |
1035 | * that it is packet based. CAIF trusts the reliability |
1036 | * of the link, no resending is implemented. |
1037 | */ |
1038 | if (sock->type == SOCK_SEQPACKET) |
1039 | sock->ops = &caif_seqpacket_ops; |
1040 | else if (sock->type == SOCK_STREAM) |
1041 | sock->ops = &caif_stream_ops; |
1042 | else |
1043 | return -ESOCKTNOSUPPORT; |
1044 | |
1045 | if (protocol < 0 || protocol >= CAIFPROTO_MAX) |
1046 | return -EPROTONOSUPPORT; |
1047 | /* |
1048 | * Set the socket state to unconnected. The socket state |
1049 | * is really not used at all in the net/core or socket.c but the |
1050 | * initialization makes sure that sock->state is not uninitialized. |
1051 | */ |
1052 | sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot); |
1053 | if (!sk) |
1054 | return -ENOMEM; |
1055 | |
1056 | cf_sk = container_of(sk, struct caifsock, sk); |
1057 | |
1058 | /* Store the protocol */ |
1059 | sk->sk_protocol = (unsigned char) protocol; |
1060 | |
1061 | /* Initialize default priority for well-known cases */ |
1062 | switch (protocol) { |
1063 | case CAIFPROTO_AT: |
1064 | sk->sk_priority = TC_PRIO_CONTROL; |
1065 | break; |
1066 | case CAIFPROTO_RFM: |
1067 | sk->sk_priority = TC_PRIO_INTERACTIVE_BULK; |
1068 | break; |
1069 | default: |
1070 | sk->sk_priority = TC_PRIO_BESTEFFORT; |
1071 | } |
1072 | |
1073 | /* |
1074 | * Lock in order to try to stop someone from opening the socket |
1075 | * too early. |
1076 | */ |
1077 | lock_sock(&(cf_sk->sk)); |
1078 | |
1079 | /* Initialize the nozero default sock structure data. */ |
1080 | sock_init_data(sock, sk); |
1081 | sk->sk_destruct = caif_sock_destructor; |
1082 | |
1083 | mutex_init(&cf_sk->readlock); /* single task reading lock */ |
1084 | cf_sk->layer.ctrlcmd = caif_ctrl_cb; |
1085 | cf_sk->sk.sk_socket->state = SS_UNCONNECTED; |
1086 | cf_sk->sk.sk_state = CAIF_DISCONNECTED; |
1087 | |
1088 | set_tx_flow_off(cf_sk); |
1089 | set_rx_flow_on(cf_sk); |
1090 | |
1091 | /* Set default options on configuration */ |
1092 | cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY; |
1093 | cf_sk->conn_req.protocol = protocol; |
1094 | release_sock(&cf_sk->sk); |
1095 | return 0; |
1096 | } |
1097 | |
1098 | |
1099 | static struct net_proto_family caif_family_ops = { |
1100 | .family = PF_CAIF, |
1101 | .create = caif_create, |
1102 | .owner = THIS_MODULE, |
1103 | }; |
1104 | |
1105 | static int __init caif_sktinit_module(void) |
1106 | { |
1107 | int err = sock_register(&caif_family_ops); |
1108 | if (!err) |
1109 | return err; |
1110 | return 0; |
1111 | } |
1112 | |
1113 | static void __exit caif_sktexit_module(void) |
1114 | { |
1115 | sock_unregister(PF_CAIF); |
1116 | } |
1117 | module_init(caif_sktinit_module); |
1118 | module_exit(caif_sktexit_module); |
1119 |
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