xref: /openbmc/linux/net/caif/caif_socket.c (revision 62910554656cdcd6b6f84a5154c4155aae4ca231)
1 /*
2  * Copyright (C) ST-Ericsson AB 2010
3  * Author:	Sjur Brendeland sjur.brandeland@stericsson.com
4  *		Per Sigmond per.sigmond@stericsson.com
5  * License terms: GNU General Public License (GPL) version 2
6  */
7 
8 #include <linux/fs.h>
9 #include <linux/init.h>
10 #include <linux/module.h>
11 #include <linux/sched.h>
12 #include <linux/spinlock.h>
13 #include <linux/mutex.h>
14 #include <linux/list.h>
15 #include <linux/wait.h>
16 #include <linux/poll.h>
17 #include <linux/tcp.h>
18 #include <linux/uaccess.h>
19 #include <asm/atomic.h>
20 
21 #include <linux/caif/caif_socket.h>
22 #include <net/caif/caif_layer.h>
23 #include <net/caif/caif_dev.h>
24 #include <net/caif/cfpkt.h>
25 
26 MODULE_LICENSE("GPL");
27 
28 #define CHNL_SKT_READ_QUEUE_HIGH 200
29 #define CHNL_SKT_READ_QUEUE_LOW 100
30 
31 static int caif_sockbuf_size = 40000;
32 static atomic_t caif_nr_socks = ATOMIC_INIT(0);
33 
34 #define CONN_STATE_OPEN_BIT	      1
35 #define CONN_STATE_PENDING_BIT	      2
36 #define CONN_STATE_PEND_DESTROY_BIT   3
37 #define CONN_REMOTE_SHUTDOWN_BIT      4
38 
39 #define TX_FLOW_ON_BIT		      1
40 #define RX_FLOW_ON_BIT		      2
41 
42 #define STATE_IS_OPEN(cf_sk) test_bit(CONN_STATE_OPEN_BIT,\
43 				    (void *) &(cf_sk)->conn_state)
44 #define STATE_IS_REMOTE_SHUTDOWN(cf_sk) test_bit(CONN_REMOTE_SHUTDOWN_BIT,\
45 				    (void *) &(cf_sk)->conn_state)
46 #define STATE_IS_PENDING(cf_sk) test_bit(CONN_STATE_PENDING_BIT,\
47 				       (void *) &(cf_sk)->conn_state)
48 #define STATE_IS_PENDING_DESTROY(cf_sk) test_bit(CONN_STATE_PEND_DESTROY_BIT,\
49 				       (void *) &(cf_sk)->conn_state)
50 
51 #define SET_STATE_PENDING_DESTROY(cf_sk) set_bit(CONN_STATE_PEND_DESTROY_BIT,\
52 				    (void *) &(cf_sk)->conn_state)
53 #define SET_STATE_OPEN(cf_sk) set_bit(CONN_STATE_OPEN_BIT,\
54 				    (void *) &(cf_sk)->conn_state)
55 #define SET_STATE_CLOSED(cf_sk) clear_bit(CONN_STATE_OPEN_BIT,\
56 					(void *) &(cf_sk)->conn_state)
57 #define SET_PENDING_ON(cf_sk) set_bit(CONN_STATE_PENDING_BIT,\
58 				    (void *) &(cf_sk)->conn_state)
59 #define SET_PENDING_OFF(cf_sk) clear_bit(CONN_STATE_PENDING_BIT,\
60 				       (void *) &(cf_sk)->conn_state)
61 #define SET_REMOTE_SHUTDOWN(cf_sk) set_bit(CONN_REMOTE_SHUTDOWN_BIT,\
62 				    (void *) &(cf_sk)->conn_state)
63 
64 #define SET_REMOTE_SHUTDOWN_OFF(dev) clear_bit(CONN_REMOTE_SHUTDOWN_BIT,\
65 				    (void *) &(dev)->conn_state)
66 #define RX_FLOW_IS_ON(cf_sk) test_bit(RX_FLOW_ON_BIT,\
67 				    (void *) &(cf_sk)->flow_state)
68 #define TX_FLOW_IS_ON(cf_sk) test_bit(TX_FLOW_ON_BIT,\
69 				    (void *) &(cf_sk)->flow_state)
70 
71 #define SET_RX_FLOW_OFF(cf_sk) clear_bit(RX_FLOW_ON_BIT,\
72 				       (void *) &(cf_sk)->flow_state)
73 #define SET_RX_FLOW_ON(cf_sk) set_bit(RX_FLOW_ON_BIT,\
74 				    (void *) &(cf_sk)->flow_state)
75 #define SET_TX_FLOW_OFF(cf_sk) clear_bit(TX_FLOW_ON_BIT,\
76 				       (void *) &(cf_sk)->flow_state)
77 #define SET_TX_FLOW_ON(cf_sk) set_bit(TX_FLOW_ON_BIT,\
78 				    (void *) &(cf_sk)->flow_state)
79 
80 #define SKT_READ_FLAG 0x01
81 #define SKT_WRITE_FLAG 0x02
82 static struct dentry *debugfsdir;
83 #include <linux/debugfs.h>
84 
85 #ifdef CONFIG_DEBUG_FS
86 struct debug_fs_counter {
87 	atomic_t num_open;
88 	atomic_t num_close;
89 	atomic_t num_init;
90 	atomic_t num_init_resp;
91 	atomic_t num_init_fail_resp;
92 	atomic_t num_deinit;
93 	atomic_t num_deinit_resp;
94 	atomic_t num_remote_shutdown_ind;
95 	atomic_t num_tx_flow_off_ind;
96 	atomic_t num_tx_flow_on_ind;
97 	atomic_t num_rx_flow_off;
98 	atomic_t num_rx_flow_on;
99 	atomic_t skb_in_use;
100 	atomic_t skb_alloc;
101 	atomic_t skb_free;
102 };
103 static struct debug_fs_counter cnt;
104 #define	dbfs_atomic_inc(v) atomic_inc(v)
105 #define	dbfs_atomic_dec(v) atomic_dec(v)
106 #else
107 #define	dbfs_atomic_inc(v)
108 #define	dbfs_atomic_dec(v)
109 #endif
110 
111 /* The AF_CAIF socket */
112 struct caifsock {
113 	/* NOTE: sk has to be the first member */
114 	struct sock sk;
115 	struct cflayer layer;
116 	char name[CAIF_LAYER_NAME_SZ];
117 	u32 conn_state;
118 	u32 flow_state;
119 	struct cfpktq *pktq;
120 	int file_mode;
121 	struct caif_connect_request conn_req;
122 	int read_queue_len;
123 	/* protect updates of read_queue_len */
124 	spinlock_t read_queue_len_lock;
125 	struct dentry *debugfs_socket_dir;
126 };
127 
128 static void drain_queue(struct caifsock *cf_sk);
129 
130 /* Packet Receive Callback function called from CAIF Stack */
131 static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
132 {
133 	struct caifsock *cf_sk;
134 	int read_queue_high;
135 	cf_sk = container_of(layr, struct caifsock, layer);
136 
137 	if (!STATE_IS_OPEN(cf_sk)) {
138 		/*FIXME: This should be allowed finally!*/
139 		pr_debug("CAIF: %s(): called after close request\n", __func__);
140 		cfpkt_destroy(pkt);
141 		return 0;
142 	}
143 	/* NOTE: This function may be called in Tasklet context! */
144 
145 	/* The queue has its own lock */
146 	cfpkt_queue(cf_sk->pktq, pkt, 0);
147 
148 	spin_lock(&cf_sk->read_queue_len_lock);
149 	cf_sk->read_queue_len++;
150 
151 	read_queue_high = (cf_sk->read_queue_len > CHNL_SKT_READ_QUEUE_HIGH);
152 	spin_unlock(&cf_sk->read_queue_len_lock);
153 
154 	if (RX_FLOW_IS_ON(cf_sk) && read_queue_high) {
155 		dbfs_atomic_inc(&cnt.num_rx_flow_off);
156 		SET_RX_FLOW_OFF(cf_sk);
157 
158 		/* Send flow off (NOTE: must not sleep) */
159 		pr_debug("CAIF: %s():"
160 			" sending flow OFF (queue len = %d)\n",
161 			__func__,
162 		     cf_sk->read_queue_len);
163 		caif_assert(cf_sk->layer.dn);
164 		caif_assert(cf_sk->layer.dn->ctrlcmd);
165 
166 		(void) cf_sk->layer.dn->modemcmd(cf_sk->layer.dn,
167 					       CAIF_MODEMCMD_FLOW_OFF_REQ);
168 	}
169 
170 	/* Signal reader that data is available. */
171 
172 	wake_up_interruptible(cf_sk->sk.sk_sleep);
173 
174 	return 0;
175 }
176 
177 /* Packet Flow Control Callback function called from CAIF */
178 static void caif_sktflowctrl_cb(struct cflayer *layr,
179 				enum caif_ctrlcmd flow,
180 				int phyid)
181 {
182 	struct caifsock *cf_sk;
183 
184 	/* NOTE: This function may be called in Tasklet context! */
185 	pr_debug("CAIF: %s(): flowctrl func called: %s.\n",
186 		      __func__,
187 		      flow == CAIF_CTRLCMD_FLOW_ON_IND ? "ON" :
188 		      flow == CAIF_CTRLCMD_FLOW_OFF_IND ? "OFF" :
189 		      flow == CAIF_CTRLCMD_INIT_RSP ? "INIT_RSP" :
190 		      flow == CAIF_CTRLCMD_DEINIT_RSP ? "DEINIT_RSP" :
191 		      flow == CAIF_CTRLCMD_INIT_FAIL_RSP ? "INIT_FAIL_RSP" :
192 		      flow ==
193 		      CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND ? "REMOTE_SHUTDOWN" :
194 		      "UKNOWN CTRL COMMAND");
195 
196 	if (layr == NULL)
197 		return;
198 
199 	cf_sk = container_of(layr, struct caifsock, layer);
200 
201 	switch (flow) {
202 	case CAIF_CTRLCMD_FLOW_ON_IND:
203 		dbfs_atomic_inc(&cnt.num_tx_flow_on_ind);
204 		/* Signal reader that data is available. */
205 		SET_TX_FLOW_ON(cf_sk);
206 		wake_up_interruptible(cf_sk->sk.sk_sleep);
207 		break;
208 
209 	case CAIF_CTRLCMD_FLOW_OFF_IND:
210 		dbfs_atomic_inc(&cnt.num_tx_flow_off_ind);
211 		SET_TX_FLOW_OFF(cf_sk);
212 		break;
213 
214 	case CAIF_CTRLCMD_INIT_RSP:
215 		dbfs_atomic_inc(&cnt.num_init_resp);
216 		/* Signal reader that data is available. */
217 		caif_assert(STATE_IS_OPEN(cf_sk));
218 		SET_PENDING_OFF(cf_sk);
219 		SET_TX_FLOW_ON(cf_sk);
220 		wake_up_interruptible(cf_sk->sk.sk_sleep);
221 		break;
222 
223 	case CAIF_CTRLCMD_DEINIT_RSP:
224 		dbfs_atomic_inc(&cnt.num_deinit_resp);
225 		caif_assert(!STATE_IS_OPEN(cf_sk));
226 		SET_PENDING_OFF(cf_sk);
227 		if (!STATE_IS_PENDING_DESTROY(cf_sk)) {
228 			if (cf_sk->sk.sk_sleep != NULL)
229 				wake_up_interruptible(cf_sk->sk.sk_sleep);
230 		}
231 		dbfs_atomic_inc(&cnt.num_deinit);
232 		sock_put(&cf_sk->sk);
233 		break;
234 
235 	case CAIF_CTRLCMD_INIT_FAIL_RSP:
236 		dbfs_atomic_inc(&cnt.num_init_fail_resp);
237 		caif_assert(STATE_IS_OPEN(cf_sk));
238 		SET_STATE_CLOSED(cf_sk);
239 		SET_PENDING_OFF(cf_sk);
240 		SET_TX_FLOW_OFF(cf_sk);
241 		wake_up_interruptible(cf_sk->sk.sk_sleep);
242 		break;
243 
244 	case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
245 		dbfs_atomic_inc(&cnt.num_remote_shutdown_ind);
246 		SET_REMOTE_SHUTDOWN(cf_sk);
247 		/* Use sk_shutdown to indicate remote shutdown indication */
248 		cf_sk->sk.sk_shutdown |= RCV_SHUTDOWN;
249 		cf_sk->file_mode = 0;
250 		wake_up_interruptible(cf_sk->sk.sk_sleep);
251 		break;
252 
253 	default:
254 		pr_debug("CAIF: %s(): Unexpected flow command %d\n",
255 			      __func__, flow);
256 	}
257 }
258 
259 static void skb_destructor(struct sk_buff *skb)
260 {
261 	dbfs_atomic_inc(&cnt.skb_free);
262 	dbfs_atomic_dec(&cnt.skb_in_use);
263 }
264 
265 
266 static int caif_recvmsg(struct kiocb *iocb, struct socket *sock,
267 				struct msghdr *m, size_t buf_len, int flags)
268 
269 {
270 	struct sock *sk = sock->sk;
271 	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
272 	struct cfpkt *pkt = NULL;
273 	size_t len;
274 	int result;
275 	struct sk_buff *skb;
276 	ssize_t ret = -EIO;
277 	int read_queue_low;
278 
279 	if (cf_sk == NULL) {
280 		pr_debug("CAIF: %s(): private_data not set!\n",
281 			      __func__);
282 		ret = -EBADFD;
283 		goto read_error;
284 	}
285 
286 	/* Don't do multiple iovec entries yet */
287 	if (m->msg_iovlen != 1)
288 		return -EOPNOTSUPP;
289 
290 	if (unlikely(!buf_len))
291 		return -EINVAL;
292 
293 	lock_sock(&(cf_sk->sk));
294 
295 	caif_assert(cf_sk->pktq);
296 
297 	if (!STATE_IS_OPEN(cf_sk)) {
298 		/* Socket is closed or closing. */
299 		if (!STATE_IS_PENDING(cf_sk)) {
300 			pr_debug("CAIF: %s(): socket is closed (by remote)\n",
301 				 __func__);
302 			ret = -EPIPE;
303 		} else {
304 			pr_debug("CAIF: %s(): socket is closing..\n", __func__);
305 			ret = -EBADF;
306 		}
307 		goto read_error;
308 	}
309 	/* Socket is open or opening. */
310 	if (STATE_IS_PENDING(cf_sk)) {
311 		pr_debug("CAIF: %s(): socket is opening...\n", __func__);
312 
313 		if (flags & MSG_DONTWAIT) {
314 			/* We can't block. */
315 			pr_debug("CAIF: %s():state pending and MSG_DONTWAIT\n",
316 				 __func__);
317 			ret = -EAGAIN;
318 			goto read_error;
319 		}
320 
321 		/*
322 		 * Blocking mode; state is pending and we need to wait
323 		 * for its conclusion.
324 		 */
325 		release_sock(&cf_sk->sk);
326 
327 		result =
328 		    wait_event_interruptible(*cf_sk->sk.sk_sleep,
329 					     !STATE_IS_PENDING(cf_sk));
330 
331 		lock_sock(&(cf_sk->sk));
332 
333 		if (result == -ERESTARTSYS) {
334 			pr_debug("CAIF: %s(): wait_event_interruptible"
335 				 " woken by a signal (1)", __func__);
336 			ret = -ERESTARTSYS;
337 			goto read_error;
338 		}
339 	}
340 
341 	if (STATE_IS_REMOTE_SHUTDOWN(cf_sk) ||
342 		!STATE_IS_OPEN(cf_sk) ||
343 		STATE_IS_PENDING(cf_sk)) {
344 
345 		pr_debug("CAIF: %s(): socket closed\n",
346 			__func__);
347 		ret = -ESHUTDOWN;
348 		goto read_error;
349 	}
350 
351 	/*
352 	 * Block if we don't have any received buffers.
353 	 * The queue has its own lock.
354 	 */
355 	while ((pkt = cfpkt_qpeek(cf_sk->pktq)) == NULL) {
356 
357 		if (flags & MSG_DONTWAIT) {
358 			pr_debug("CAIF: %s(): MSG_DONTWAIT\n", __func__);
359 			ret = -EAGAIN;
360 			goto read_error;
361 		}
362 		trace_printk("CAIF: %s() wait_event\n", __func__);
363 
364 		/* Let writers in. */
365 		release_sock(&cf_sk->sk);
366 
367 		/* Block reader until data arrives or socket is closed. */
368 		if (wait_event_interruptible(*cf_sk->sk.sk_sleep,
369 					cfpkt_qpeek(cf_sk->pktq)
370 					|| STATE_IS_REMOTE_SHUTDOWN(cf_sk)
371 					|| !STATE_IS_OPEN(cf_sk)) ==
372 		    -ERESTARTSYS) {
373 			pr_debug("CAIF: %s():"
374 				" wait_event_interruptible woken by "
375 				"a signal, signal_pending(current) = %d\n",
376 				__func__,
377 				signal_pending(current));
378 			return -ERESTARTSYS;
379 		}
380 
381 		trace_printk("CAIF: %s() awake\n", __func__);
382 		if (STATE_IS_REMOTE_SHUTDOWN(cf_sk)) {
383 			pr_debug("CAIF: %s(): "
384 				 "received remote_shutdown indication\n",
385 				 __func__);
386 			ret = -ESHUTDOWN;
387 			goto read_error_no_unlock;
388 		}
389 
390 		/* I want to be alone on cf_sk (except status and queue). */
391 		lock_sock(&(cf_sk->sk));
392 
393 		if (!STATE_IS_OPEN(cf_sk)) {
394 			/* Someone closed the link, report error. */
395 			pr_debug("CAIF: %s(): remote end shutdown!\n",
396 				      __func__);
397 			ret = -EPIPE;
398 			goto read_error;
399 		}
400 	}
401 
402 	/* The queue has its own lock. */
403 	len = cfpkt_getlen(pkt);
404 
405 	/* Check max length that can be copied. */
406 	if (len <= buf_len)
407 		pkt = cfpkt_dequeue(cf_sk->pktq);
408 	else {
409 		pr_debug("CAIF: %s(): user buffer too small (%ld,%ld)\n",
410 			 __func__, (long) len, (long) buf_len);
411 		if (sock->type == SOCK_SEQPACKET) {
412 			ret = -EMSGSIZE;
413 			goto read_error;
414 		}
415 		len = buf_len;
416 	}
417 
418 
419 	spin_lock(&cf_sk->read_queue_len_lock);
420 	cf_sk->read_queue_len--;
421 	read_queue_low = (cf_sk->read_queue_len < CHNL_SKT_READ_QUEUE_LOW);
422 	spin_unlock(&cf_sk->read_queue_len_lock);
423 
424 	if (!RX_FLOW_IS_ON(cf_sk) && read_queue_low) {
425 		dbfs_atomic_inc(&cnt.num_rx_flow_on);
426 		SET_RX_FLOW_ON(cf_sk);
427 
428 		/* Send flow on. */
429 		pr_debug("CAIF: %s(): sending flow ON (queue len = %d)\n",
430 			 __func__, cf_sk->read_queue_len);
431 		caif_assert(cf_sk->layer.dn);
432 		caif_assert(cf_sk->layer.dn->ctrlcmd);
433 		(void) cf_sk->layer.dn->modemcmd(cf_sk->layer.dn,
434 					       CAIF_MODEMCMD_FLOW_ON_REQ);
435 
436 		caif_assert(cf_sk->read_queue_len >= 0);
437 	}
438 
439 	skb = cfpkt_tonative(pkt);
440 	result = skb_copy_datagram_iovec(skb, 0, m->msg_iov, len);
441 	skb_pull(skb, len);
442 
443 	if (result) {
444 		pr_debug("CAIF: %s(): copy to_iovec failed\n", __func__);
445 		cfpkt_destroy(pkt);
446 		ret = -EFAULT;
447 		goto read_error;
448 	}
449 
450 	/* Free packet and remove from queue */
451 	if (skb->len == 0)
452 		skb_free_datagram(sk, skb);
453 
454 	/* Let the others in. */
455 	release_sock(&cf_sk->sk);
456 	return len;
457 
458 read_error:
459 	release_sock(&cf_sk->sk);
460 read_error_no_unlock:
461 	return ret;
462 }
463 
464 /* Send a signal as a consequence of sendmsg, sendto or caif_sendmsg. */
465 static int caif_sendmsg(struct kiocb *kiocb, struct socket *sock,
466 			struct msghdr *msg, size_t len)
467 {
468 
469 	struct sock *sk = sock->sk;
470 	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
471 	size_t payload_size = msg->msg_iov->iov_len;
472 	struct cfpkt *pkt = NULL;
473 	struct caif_payload_info info;
474 	unsigned char *txbuf;
475 	ssize_t ret = -EIO;
476 	int result;
477 	struct sk_buff *skb;
478 	caif_assert(msg->msg_iovlen == 1);
479 
480 	if (cf_sk == NULL) {
481 		pr_debug("CAIF: %s(): private_data not set!\n",
482 			      __func__);
483 		ret = -EBADFD;
484 		goto write_error_no_unlock;
485 	}
486 
487 	if (unlikely(msg->msg_iov->iov_base == NULL)) {
488 		pr_warning("CAIF: %s(): Buffer is NULL.\n", __func__);
489 		ret = -EINVAL;
490 		goto write_error_no_unlock;
491 	}
492 
493 	if (payload_size > CAIF_MAX_PAYLOAD_SIZE) {
494 		pr_debug("CAIF: %s(): buffer too long\n", __func__);
495 		if (sock->type == SOCK_SEQPACKET) {
496 			ret = -EINVAL;
497 			goto write_error_no_unlock;
498 		}
499 		payload_size = CAIF_MAX_PAYLOAD_SIZE;
500 	}
501 
502 	/* I want to be alone on cf_sk (except status and queue) */
503 	lock_sock(&(cf_sk->sk));
504 
505 	caif_assert(cf_sk->pktq);
506 
507 	if (!STATE_IS_OPEN(cf_sk)) {
508 		/* Socket is closed or closing */
509 		if (!STATE_IS_PENDING(cf_sk)) {
510 			pr_debug("CAIF: %s(): socket is closed (by remote)\n",
511 				 __func__);
512 			ret = -EPIPE;
513 		} else {
514 			pr_debug("CAIF: %s(): socket is closing...\n",
515 				 __func__);
516 			ret = -EBADF;
517 		}
518 		goto write_error;
519 	}
520 
521 	/* Socket is open or opening */
522 	if (STATE_IS_PENDING(cf_sk)) {
523 		pr_debug("CAIF: %s(): socket is opening...\n", __func__);
524 
525 		if (msg->msg_flags & MSG_DONTWAIT) {
526 			/* We can't block */
527 			trace_printk("CAIF: %s():state pending:"
528 				     "state=MSG_DONTWAIT\n", __func__);
529 			ret = -EAGAIN;
530 			goto write_error;
531 		}
532 		/* Let readers in */
533 		release_sock(&cf_sk->sk);
534 
535 		/*
536 		 * Blocking mode; state is pending and we need to wait
537 		 * for its conclusion.
538 		 */
539 		result =
540 		    wait_event_interruptible(*cf_sk->sk.sk_sleep,
541 					     !STATE_IS_PENDING(cf_sk));
542 		/* I want to be alone on cf_sk (except status and queue) */
543 		lock_sock(&(cf_sk->sk));
544 
545 		if (result == -ERESTARTSYS) {
546 			pr_debug("CAIF: %s(): wait_event_interruptible"
547 				 " woken by a signal (1)", __func__);
548 			ret = -ERESTARTSYS;
549 			goto write_error;
550 		}
551 	}
552 	if (STATE_IS_REMOTE_SHUTDOWN(cf_sk) ||
553 		!STATE_IS_OPEN(cf_sk) ||
554 		STATE_IS_PENDING(cf_sk)) {
555 
556 		pr_debug("CAIF: %s(): socket closed\n",
557 			__func__);
558 		ret = -ESHUTDOWN;
559 		goto write_error;
560 	}
561 
562 	if (!TX_FLOW_IS_ON(cf_sk)) {
563 
564 		/* Flow is off. Check non-block flag */
565 		if (msg->msg_flags & MSG_DONTWAIT) {
566 			trace_printk("CAIF: %s(): MSG_DONTWAIT and tx flow off",
567 				 __func__);
568 			ret = -EAGAIN;
569 			goto write_error;
570 		}
571 
572 		/* release lock before waiting */
573 		release_sock(&cf_sk->sk);
574 
575 		/* Wait until flow is on or socket is closed */
576 		if (wait_event_interruptible(*cf_sk->sk.sk_sleep,
577 					TX_FLOW_IS_ON(cf_sk)
578 					|| !STATE_IS_OPEN(cf_sk)
579 					|| STATE_IS_REMOTE_SHUTDOWN(cf_sk)
580 					) == -ERESTARTSYS) {
581 			pr_debug("CAIF: %s():"
582 				 " wait_event_interruptible woken by a signal",
583 				 __func__);
584 			ret = -ERESTARTSYS;
585 			goto write_error_no_unlock;
586 		}
587 
588 		/* I want to be alone on cf_sk (except status and queue) */
589 		lock_sock(&(cf_sk->sk));
590 
591 		if (!STATE_IS_OPEN(cf_sk)) {
592 			/* someone closed the link, report error */
593 			pr_debug("CAIF: %s(): remote end shutdown!\n",
594 				      __func__);
595 			ret = -EPIPE;
596 			goto write_error;
597 		}
598 
599 		if (STATE_IS_REMOTE_SHUTDOWN(cf_sk)) {
600 			pr_debug("CAIF: %s(): "
601 				 "received remote_shutdown indication\n",
602 				 __func__);
603 			ret = -ESHUTDOWN;
604 			goto write_error;
605 		}
606 	}
607 
608 	pkt = cfpkt_create(payload_size);
609 	skb = (struct sk_buff *)pkt;
610 	skb->destructor = skb_destructor;
611 	skb->sk = sk;
612 	dbfs_atomic_inc(&cnt.skb_alloc);
613 	dbfs_atomic_inc(&cnt.skb_in_use);
614 	if (cfpkt_raw_append(pkt, (void **) &txbuf, payload_size) < 0) {
615 		pr_debug("CAIF: %s(): cfpkt_raw_append failed\n", __func__);
616 		cfpkt_destroy(pkt);
617 		ret = -EINVAL;
618 		goto write_error;
619 	}
620 
621 	/* Copy data into buffer. */
622 	if (copy_from_user(txbuf, msg->msg_iov->iov_base, payload_size)) {
623 		pr_debug("CAIF: %s(): copy_from_user returned non zero.\n",
624 			 __func__);
625 		cfpkt_destroy(pkt);
626 		ret = -EINVAL;
627 		goto write_error;
628 	}
629 	memset(&info, 0, sizeof(info));
630 
631 	/* Send the packet down the stack. */
632 	caif_assert(cf_sk->layer.dn);
633 	caif_assert(cf_sk->layer.dn->transmit);
634 
635 	do {
636 		ret = cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
637 
638 		if (likely((ret >= 0) || (ret != -EAGAIN)))
639 			break;
640 
641 		/* EAGAIN - retry */
642 		if (msg->msg_flags & MSG_DONTWAIT) {
643 			pr_debug("CAIF: %s(): NONBLOCK and transmit failed,"
644 				 " error = %ld\n", __func__, (long) ret);
645 			ret = -EAGAIN;
646 			goto write_error;
647 		}
648 
649 		/* Let readers in */
650 		release_sock(&cf_sk->sk);
651 
652 		/* Wait until flow is on or socket is closed */
653 		if (wait_event_interruptible(*cf_sk->sk.sk_sleep,
654 					TX_FLOW_IS_ON(cf_sk)
655 					|| !STATE_IS_OPEN(cf_sk)
656 					|| STATE_IS_REMOTE_SHUTDOWN(cf_sk)
657 					) == -ERESTARTSYS) {
658 			pr_debug("CAIF: %s(): wait_event_interruptible"
659 				 " woken by a signal", __func__);
660 			ret = -ERESTARTSYS;
661 			goto write_error_no_unlock;
662 		}
663 
664 		/* I want to be alone on cf_sk (except status and queue) */
665 		lock_sock(&(cf_sk->sk));
666 
667 	} while (ret == -EAGAIN);
668 
669 	if (ret < 0) {
670 		cfpkt_destroy(pkt);
671 		pr_debug("CAIF: %s(): transmit failed, error = %ld\n",
672 			 __func__, (long) ret);
673 
674 		goto write_error;
675 	}
676 
677 	release_sock(&cf_sk->sk);
678 	return payload_size;
679 
680 write_error:
681 	release_sock(&cf_sk->sk);
682 write_error_no_unlock:
683 	return ret;
684 }
685 
686 static unsigned int caif_poll(struct file *file, struct socket *sock,
687 						poll_table *wait)
688 {
689 	struct sock *sk = sock->sk;
690 	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
691 	u32 mask = 0;
692 	poll_wait(file, sk->sk_sleep, wait);
693 	lock_sock(&(cf_sk->sk));
694 	if (!STATE_IS_OPEN(cf_sk)) {
695 		if (!STATE_IS_PENDING(cf_sk))
696 			mask |= POLLHUP;
697 	} else {
698 		if (cfpkt_qpeek(cf_sk->pktq) != NULL)
699 			mask |= (POLLIN | POLLRDNORM);
700 		if (TX_FLOW_IS_ON(cf_sk))
701 			mask |= (POLLOUT | POLLWRNORM);
702 	}
703 	release_sock(&cf_sk->sk);
704 	trace_printk("CAIF: %s(): poll mask=0x%04x\n",
705 		      __func__, mask);
706 	return mask;
707 }
708 
709 static void drain_queue(struct caifsock *cf_sk)
710 {
711 	struct cfpkt *pkt = NULL;
712 
713 	/* Empty the queue */
714 	do {
715 		/* The queue has its own lock */
716 		if (!cf_sk->pktq)
717 			break;
718 
719 		pkt = cfpkt_dequeue(cf_sk->pktq);
720 		if (!pkt)
721 			break;
722 		pr_debug("CAIF: %s(): freeing packet from read queue\n",
723 			 __func__);
724 		cfpkt_destroy(pkt);
725 
726 	} while (1);
727 
728 	cf_sk->read_queue_len = 0;
729 }
730 
731 static int setsockopt(struct socket *sock,
732 			int lvl, int opt, char __user *ov, unsigned int ol)
733 {
734 	struct sock *sk = sock->sk;
735 	struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
736 	int prio, linksel;
737 	struct ifreq ifreq;
738 
739 	if (STATE_IS_OPEN(cf_sk)) {
740 		pr_debug("CAIF: %s(): setsockopt "
741 			 "cannot be done on a connected socket\n",
742 			 __func__);
743 		return -ENOPROTOOPT;
744 	}
745 	switch (opt) {
746 	case CAIFSO_LINK_SELECT:
747 		if (ol < sizeof(int)) {
748 			pr_debug("CAIF: %s(): setsockopt"
749 				 " CAIFSO_CHANNEL_CONFIG bad size\n", __func__);
750 			return -EINVAL;
751 		}
752 		if (lvl != SOL_CAIF)
753 			goto bad_sol;
754 		if (copy_from_user(&linksel, ov, sizeof(int)))
755 			return -EINVAL;
756 		lock_sock(&(cf_sk->sk));
757 		cf_sk->conn_req.link_selector = linksel;
758 		release_sock(&cf_sk->sk);
759 		return 0;
760 
761 	case SO_PRIORITY:
762 		if (lvl != SOL_SOCKET)
763 			goto bad_sol;
764 		if (ol < sizeof(int)) {
765 			pr_debug("CAIF: %s(): setsockopt"
766 				 " SO_PRIORITY bad size\n", __func__);
767 			return -EINVAL;
768 		}
769 		if (copy_from_user(&prio, ov, sizeof(int)))
770 			return -EINVAL;
771 		lock_sock(&(cf_sk->sk));
772 		cf_sk->conn_req.priority = prio;
773 		pr_debug("CAIF: %s(): Setting sockopt priority=%d\n", __func__,
774 			cf_sk->conn_req.priority);
775 		release_sock(&cf_sk->sk);
776 		return 0;
777 
778 	case SO_BINDTODEVICE:
779 		if (lvl != SOL_SOCKET)
780 			goto bad_sol;
781 		if (ol < sizeof(struct ifreq)) {
782 			pr_debug("CAIF: %s(): setsockopt"
783 				 " SO_PRIORITY bad size\n", __func__);
784 			return -EINVAL;
785 		}
786 		if (copy_from_user(&ifreq, ov, sizeof(ifreq)))
787 			return -EFAULT;
788 		lock_sock(&(cf_sk->sk));
789 		strncpy(cf_sk->conn_req.link_name, ifreq.ifr_name,
790 			sizeof(cf_sk->conn_req.link_name));
791 		cf_sk->conn_req.link_name
792 			[sizeof(cf_sk->conn_req.link_name)-1] = 0;
793 		release_sock(&cf_sk->sk);
794 		return 0;
795 
796 	case CAIFSO_REQ_PARAM:
797 		if (lvl != SOL_CAIF)
798 			goto bad_sol;
799 		if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
800 			return -ENOPROTOOPT;
801 		if (ol > sizeof(cf_sk->conn_req.param.data))
802 			goto req_param_bad_size;
803 
804 		lock_sock(&(cf_sk->sk));
805 		cf_sk->conn_req.param.size = ol;
806 		if (copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) {
807 			release_sock(&cf_sk->sk);
808 req_param_bad_size:
809 			pr_debug("CAIF: %s(): setsockopt"
810 				 " CAIFSO_CHANNEL_CONFIG bad size\n", __func__);
811 			return -EINVAL;
812 		}
813 
814 		release_sock(&cf_sk->sk);
815 		return 0;
816 
817 	default:
818 		pr_debug("CAIF: %s(): unhandled option %d\n", __func__, opt);
819 		return -EINVAL;
820 	}
821 
822 	return 0;
823 bad_sol:
824 	pr_debug("CAIF: %s(): setsockopt bad level\n", __func__);
825 	return -ENOPROTOOPT;
826 
827 }
828 
829 static int caif_connect(struct socket *sock, struct sockaddr *uservaddr,
830 	       int sockaddr_len, int flags)
831 {
832 	struct caifsock *cf_sk = NULL;
833 	int result = -1;
834 	int mode = 0;
835 	int ret = -EIO;
836 	struct sock *sk = sock->sk;
837 	BUG_ON(sk == NULL);
838 
839 	cf_sk = container_of(sk, struct caifsock, sk);
840 
841 	trace_printk("CAIF: %s(): cf_sk=%p OPEN=%d, TX_FLOW=%d, RX_FLOW=%d\n",
842 		 __func__, cf_sk,
843 		STATE_IS_OPEN(cf_sk),
844 		TX_FLOW_IS_ON(cf_sk), RX_FLOW_IS_ON(cf_sk));
845 
846 
847 	if (sock->type == SOCK_SEQPACKET || sock->type == SOCK_STREAM)
848 		sock->state	= SS_CONNECTING;
849 	else
850 		goto out;
851 
852 	/* I want to be alone on cf_sk (except status and queue) */
853 	lock_sock(&(cf_sk->sk));
854 
855 	if (sockaddr_len != sizeof(struct sockaddr_caif)) {
856 		pr_debug("CAIF: %s(): Bad address len (%ld,%lu)\n",
857 			 __func__, (long) sockaddr_len,
858 			(long unsigned) sizeof(struct sockaddr_caif));
859 		ret = -EINVAL;
860 		goto open_error;
861 	}
862 
863 	if (uservaddr->sa_family != AF_CAIF) {
864 		pr_debug("CAIF: %s(): Bad address family (%d)\n",
865 			 __func__, uservaddr->sa_family);
866 		ret = -EAFNOSUPPORT;
867 		goto open_error;
868 	}
869 
870 	memcpy(&cf_sk->conn_req.sockaddr, uservaddr,
871 		sizeof(struct sockaddr_caif));
872 
873 	dbfs_atomic_inc(&cnt.num_open);
874 	mode = SKT_READ_FLAG | SKT_WRITE_FLAG;
875 
876 	/* If socket is not open, make sure socket is in fully closed state */
877 	if (!STATE_IS_OPEN(cf_sk)) {
878 		/* Has link close response been received (if we ever sent it)?*/
879 		if (STATE_IS_PENDING(cf_sk)) {
880 			/*
881 			 * Still waiting for close response from remote.
882 			 * If opened non-blocking, report "would block"
883 			 */
884 			if (flags & O_NONBLOCK) {
885 				pr_debug("CAIF: %s(): O_NONBLOCK"
886 					" && close pending\n", __func__);
887 				ret = -EAGAIN;
888 				goto open_error;
889 			}
890 
891 			pr_debug("CAIF: %s(): Wait for close response"
892 				 " from remote...\n", __func__);
893 
894 			release_sock(&cf_sk->sk);
895 
896 			/*
897 			 * Blocking mode; close is pending and we need to wait
898 			 * for its conclusion.
899 			 */
900 			result =
901 			    wait_event_interruptible(*cf_sk->sk.sk_sleep,
902 						     !STATE_IS_PENDING(cf_sk));
903 
904 			lock_sock(&(cf_sk->sk));
905 			if (result == -ERESTARTSYS) {
906 				pr_debug("CAIF: %s(): wait_event_interruptible"
907 					 "woken by a signal (1)", __func__);
908 				ret = -ERESTARTSYS;
909 				goto open_error;
910 			}
911 		}
912 	}
913 
914 	/* socket is now either closed, pending open or open */
915 	if (STATE_IS_OPEN(cf_sk) && !STATE_IS_PENDING(cf_sk)) {
916 		/* Open */
917 		pr_debug("CAIF: %s(): Socket is already opened (cf_sk=%p)"
918 			" check access f_flags = 0x%x file_mode = 0x%x\n",
919 			 __func__, cf_sk, mode, cf_sk->file_mode);
920 
921 	} else {
922 		/* We are closed or pending open.
923 		 * If closed:	    send link setup
924 		 * If pending open: link setup already sent (we could have been
925 		 *		    interrupted by a signal last time)
926 		 */
927 		if (!STATE_IS_OPEN(cf_sk)) {
928 			/* First opening of file; connect lower layers: */
929 			/* Drain queue (very unlikely) */
930 			drain_queue(cf_sk);
931 
932 			cf_sk->layer.receive = caif_sktrecv_cb;
933 			SET_STATE_OPEN(cf_sk);
934 			SET_PENDING_ON(cf_sk);
935 
936 			/* Register this channel. */
937 			result =
938 				caif_connect_client(&cf_sk->conn_req,
939 							&cf_sk->layer);
940 			if (result < 0) {
941 				pr_debug("CAIF: %s(): can't register channel\n",
942 					__func__);
943 				ret = -EIO;
944 				SET_STATE_CLOSED(cf_sk);
945 				SET_PENDING_OFF(cf_sk);
946 				goto open_error;
947 			}
948 			dbfs_atomic_inc(&cnt.num_init);
949 		}
950 
951 		/* If opened non-blocking, report "success".
952 		 */
953 		if (flags & O_NONBLOCK) {
954 			pr_debug("CAIF: %s(): O_NONBLOCK success\n",
955 				 __func__);
956 			ret = -EINPROGRESS;
957 			cf_sk->sk.sk_err = -EINPROGRESS;
958 			goto open_error;
959 		}
960 
961 		trace_printk("CAIF: %s(): Wait for connect response\n",
962 			     __func__);
963 
964 		/* release lock before waiting */
965 		release_sock(&cf_sk->sk);
966 
967 		result =
968 		    wait_event_interruptible(*cf_sk->sk.sk_sleep,
969 					     !STATE_IS_PENDING(cf_sk));
970 
971 		lock_sock(&(cf_sk->sk));
972 
973 		if (result == -ERESTARTSYS) {
974 			pr_debug("CAIF: %s(): wait_event_interruptible"
975 				 "woken by a signal (2)", __func__);
976 			ret = -ERESTARTSYS;
977 			goto open_error;
978 		}
979 
980 		if (!STATE_IS_OPEN(cf_sk)) {
981 			/* Lower layers said "no" */
982 			pr_debug("CAIF: %s(): Closed received\n", __func__);
983 			ret = -EPIPE;
984 			goto open_error;
985 		}
986 
987 		trace_printk("CAIF: %s(): Connect received\n", __func__);
988 	}
989 	/* Open is ok */
990 	cf_sk->file_mode |= mode;
991 
992 	trace_printk("CAIF: %s(): Connected - file mode = %x\n",
993 		  __func__, cf_sk->file_mode);
994 
995 	release_sock(&cf_sk->sk);
996 	return 0;
997 open_error:
998 	sock->state	= SS_UNCONNECTED;
999 	release_sock(&cf_sk->sk);
1000 out:
1001 	return ret;
1002 }
1003 
1004 static int caif_shutdown(struct socket *sock, int how)
1005 {
1006 	struct caifsock *cf_sk = NULL;
1007 	int result = 0;
1008 	int tx_flow_state_was_on;
1009 	struct sock *sk = sock->sk;
1010 
1011 	trace_printk("CAIF: %s(): enter\n", __func__);
1012 	pr_debug("f_flags=%x\n", sock->file->f_flags);
1013 
1014 	if (how != SHUT_RDWR)
1015 		return -EOPNOTSUPP;
1016 
1017 	cf_sk = container_of(sk, struct caifsock, sk);
1018 	if (cf_sk == NULL) {
1019 		pr_debug("CAIF: %s(): COULD NOT FIND SOCKET\n", __func__);
1020 		return -EBADF;
1021 	}
1022 
1023 	/* I want to be alone on cf_sk (except status queue) */
1024 	lock_sock(&(cf_sk->sk));
1025 	sock_hold(&cf_sk->sk);
1026 
1027 	/* IS_CLOSED have double meaning:
1028 	 * 1) Spontanous Remote Shutdown Request.
1029 	 * 2) Ack on a channel teardown(disconnect)
1030 	 * Must clear bit in case we previously received
1031 	 * remote shudown request.
1032 	 */
1033 	if (STATE_IS_OPEN(cf_sk) && !STATE_IS_PENDING(cf_sk)) {
1034 		SET_STATE_CLOSED(cf_sk);
1035 		SET_PENDING_ON(cf_sk);
1036 		tx_flow_state_was_on = TX_FLOW_IS_ON(cf_sk);
1037 		SET_TX_FLOW_OFF(cf_sk);
1038 
1039 		/* Hold the socket until DEINIT_RSP is received */
1040 		sock_hold(&cf_sk->sk);
1041 		result = caif_disconnect_client(&cf_sk->layer);
1042 
1043 		if (result < 0) {
1044 			pr_debug("CAIF: %s(): "
1045 					"caif_disconnect_client() failed\n",
1046 					 __func__);
1047 			SET_STATE_CLOSED(cf_sk);
1048 			SET_PENDING_OFF(cf_sk);
1049 			SET_TX_FLOW_OFF(cf_sk);
1050 			release_sock(&cf_sk->sk);
1051 			sock_put(&cf_sk->sk);
1052 			return -EIO;
1053 		}
1054 
1055 	}
1056 	if (STATE_IS_REMOTE_SHUTDOWN(cf_sk)) {
1057 		SET_PENDING_OFF(cf_sk);
1058 		SET_REMOTE_SHUTDOWN_OFF(cf_sk);
1059 	}
1060 
1061 	/*
1062 	 * Socket is no longer in state pending close,
1063 	 * and we can release the reference.
1064 	 */
1065 
1066 	dbfs_atomic_inc(&cnt.num_close);
1067 	drain_queue(cf_sk);
1068 	SET_RX_FLOW_ON(cf_sk);
1069 	cf_sk->file_mode = 0;
1070 	sock_put(&cf_sk->sk);
1071 	release_sock(&cf_sk->sk);
1072 	if (!result && (sock->file->f_flags & O_NONBLOCK)) {
1073 		pr_debug("nonblocking shutdown returing -EAGAIN\n");
1074 		return -EAGAIN;
1075 	} else
1076 		return result;
1077 }
1078 
1079 static ssize_t caif_sock_no_sendpage(struct socket *sock,
1080 				     struct page *page,
1081 				     int offset, size_t size, int flags)
1082 {
1083 	return -EOPNOTSUPP;
1084 }
1085 
1086 /* This function is called as part of close. */
1087 static int caif_release(struct socket *sock)
1088 {
1089 	struct sock *sk = sock->sk;
1090 	struct caifsock *cf_sk = NULL;
1091 	int res;
1092 	caif_assert(sk != NULL);
1093 	cf_sk = container_of(sk, struct caifsock, sk);
1094 
1095 	if (cf_sk->debugfs_socket_dir != NULL)
1096 		debugfs_remove_recursive(cf_sk->debugfs_socket_dir);
1097 
1098 	res = caif_shutdown(sock, SHUT_RDWR);
1099 	if (res && res != -EINPROGRESS)
1100 		return res;
1101 
1102 	/*
1103 	 * FIXME: Shutdown should probably be possible to do async
1104 	 * without flushing queues, allowing reception of frames while
1105 	 * waiting for DEINIT_IND.
1106 	 * Release should always block, to allow secure decoupling of
1107 	 * CAIF stack.
1108 	 */
1109 	if (!(sock->file->f_flags & O_NONBLOCK)) {
1110 		res = wait_event_interruptible(*cf_sk->sk.sk_sleep,
1111 						!STATE_IS_PENDING(cf_sk));
1112 
1113 		if (res == -ERESTARTSYS) {
1114 			pr_debug("CAIF: %s(): wait_event_interruptible"
1115 				"woken by a signal (1)", __func__);
1116 		}
1117 	}
1118 	lock_sock(&(cf_sk->sk));
1119 
1120 	sock->sk = NULL;
1121 
1122 	/* Detach the socket from its process context by making it orphan. */
1123 	sock_orphan(sk);
1124 
1125 	/*
1126 	 * Setting SHUTDOWN_MASK means that both send and receive are shutdown
1127 	 * for the socket.
1128 	 */
1129 	sk->sk_shutdown = SHUTDOWN_MASK;
1130 
1131 	/*
1132 	 * Set the socket state to closed, the TCP_CLOSE macro is used when
1133 	 * closing any socket.
1134 	 */
1135 
1136 	/* Flush out this sockets receive queue. */
1137 	drain_queue(cf_sk);
1138 
1139 	/* Finally release the socket. */
1140 	SET_STATE_PENDING_DESTROY(cf_sk);
1141 
1142 	release_sock(&cf_sk->sk);
1143 
1144 	sock_put(sk);
1145 
1146 	/*
1147 	 * The rest of the cleanup will be handled from the
1148 	 * caif_sock_destructor
1149 	 */
1150 	return res;
1151 }
1152 
1153 static const struct proto_ops caif_ops = {
1154 	.family = PF_CAIF,
1155 	.owner = THIS_MODULE,
1156 	.release = caif_release,
1157 	.bind = sock_no_bind,
1158 	.connect = caif_connect,
1159 	.socketpair = sock_no_socketpair,
1160 	.accept = sock_no_accept,
1161 	.getname = sock_no_getname,
1162 	.poll = caif_poll,
1163 	.ioctl = sock_no_ioctl,
1164 	.listen = sock_no_listen,
1165 	.shutdown = caif_shutdown,
1166 	.setsockopt = setsockopt,
1167 	.getsockopt = sock_no_getsockopt,
1168 	.sendmsg = caif_sendmsg,
1169 	.recvmsg = caif_recvmsg,
1170 	.mmap = sock_no_mmap,
1171 	.sendpage = caif_sock_no_sendpage,
1172 };
1173 
1174 /* This function is called when a socket is finally destroyed. */
1175 static void caif_sock_destructor(struct sock *sk)
1176 {
1177 	struct caifsock *cf_sk = NULL;
1178 	cf_sk = container_of(sk, struct caifsock, sk);
1179 	/* Error checks. */
1180 	caif_assert(!atomic_read(&sk->sk_wmem_alloc));
1181 	caif_assert(sk_unhashed(sk));
1182 	caif_assert(!sk->sk_socket);
1183 	if (!sock_flag(sk, SOCK_DEAD)) {
1184 		pr_debug("CAIF: %s(): 0x%p", __func__, sk);
1185 		return;
1186 	}
1187 
1188 	if (STATE_IS_OPEN(cf_sk)) {
1189 		pr_debug("CAIF: %s(): socket is opened (cf_sk=%p)"
1190 			 " file_mode = 0x%x\n", __func__,
1191 			 cf_sk, cf_sk->file_mode);
1192 		return;
1193 	}
1194 	drain_queue(cf_sk);
1195 	kfree(cf_sk->pktq);
1196 
1197 	trace_printk("CAIF: %s(): caif_sock_destructor: Removing socket %s\n",
1198 		__func__, cf_sk->name);
1199 	atomic_dec(&caif_nr_socks);
1200 }
1201 
1202 static int caif_create(struct net *net, struct socket *sock, int protocol,
1203 		       int kern)
1204 {
1205 	struct sock *sk = NULL;
1206 	struct caifsock *cf_sk = NULL;
1207 	int result = 0;
1208 	static struct proto prot = {.name = "PF_CAIF",
1209 		.owner = THIS_MODULE,
1210 		.obj_size = sizeof(struct caifsock),
1211 	};
1212 
1213 	/*
1214 	 * The sock->type specifies the socket type to use.
1215 	 * in SEQPACKET mode packet boundaries are enforced.
1216 	 */
1217 	if (sock->type != SOCK_SEQPACKET && sock->type != SOCK_STREAM)
1218 		return -ESOCKTNOSUPPORT;
1219 
1220 	if (net != &init_net)
1221 		return -EAFNOSUPPORT;
1222 
1223 	if (protocol < 0 || protocol >= CAIFPROTO_MAX)
1224 		return -EPROTONOSUPPORT;
1225 	/*
1226 	 * Set the socket state to unconnected.	 The socket state is really
1227 	 * not used at all in the net/core or socket.c but the
1228 	 * initialization makes sure that sock->state is not uninitialized.
1229 	 */
1230 	sock->state = SS_UNCONNECTED;
1231 
1232 	sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot);
1233 	if (!sk)
1234 		return -ENOMEM;
1235 
1236 	cf_sk = container_of(sk, struct caifsock, sk);
1237 
1238 	/* Store the protocol */
1239 	sk->sk_protocol = (unsigned char) protocol;
1240 
1241 	spin_lock_init(&cf_sk->read_queue_len_lock);
1242 
1243 	/* Fill in some information concerning the misc socket. */
1244 	snprintf(cf_sk->name, sizeof(cf_sk->name), "cf_sk%d",
1245 		atomic_read(&caif_nr_socks));
1246 
1247 	/*
1248 	 * Lock in order to try to stop someone from opening the socket
1249 	 * too early.
1250 	 */
1251 	lock_sock(&(cf_sk->sk));
1252 
1253 	/* Initialize the nozero default sock structure data. */
1254 	sock_init_data(sock, sk);
1255 	sock->ops = &caif_ops;
1256 	sk->sk_destruct = caif_sock_destructor;
1257 	sk->sk_sndbuf = caif_sockbuf_size;
1258 	sk->sk_rcvbuf = caif_sockbuf_size;
1259 
1260 	cf_sk->pktq = cfpktq_create();
1261 
1262 	if (!cf_sk->pktq) {
1263 		pr_err("CAIF: %s(): queue create failed.\n", __func__);
1264 		result = -ENOMEM;
1265 		release_sock(&cf_sk->sk);
1266 		goto err_failed;
1267 	}
1268 	cf_sk->layer.ctrlcmd = caif_sktflowctrl_cb;
1269 	SET_STATE_CLOSED(cf_sk);
1270 	SET_PENDING_OFF(cf_sk);
1271 	SET_TX_FLOW_OFF(cf_sk);
1272 	SET_RX_FLOW_ON(cf_sk);
1273 
1274 	/* Set default options on configuration */
1275 	cf_sk->conn_req.priority = CAIF_PRIO_NORMAL;
1276 	cf_sk->conn_req.link_selector = CAIF_LINK_HIGH_BANDW;
1277 	cf_sk->conn_req.protocol = protocol;
1278 	/* Increase the number of sockets created. */
1279 	atomic_inc(&caif_nr_socks);
1280 	if (!IS_ERR(debugfsdir)) {
1281 		cf_sk->debugfs_socket_dir =
1282 			debugfs_create_dir(cf_sk->name, debugfsdir);
1283 		debugfs_create_u32("conn_state", S_IRUSR | S_IWUSR,
1284 				cf_sk->debugfs_socket_dir, &cf_sk->conn_state);
1285 		debugfs_create_u32("flow_state", S_IRUSR | S_IWUSR,
1286 				cf_sk->debugfs_socket_dir, &cf_sk->flow_state);
1287 		debugfs_create_u32("read_queue_len", S_IRUSR | S_IWUSR,
1288 				cf_sk->debugfs_socket_dir,
1289 				(u32 *) &cf_sk->read_queue_len);
1290 		debugfs_create_u32("identity", S_IRUSR | S_IWUSR,
1291 				cf_sk->debugfs_socket_dir,
1292 				(u32 *) &cf_sk->layer.id);
1293 	}
1294 	release_sock(&cf_sk->sk);
1295 	return 0;
1296 err_failed:
1297 	sk_free(sk);
1298 	return result;
1299 }
1300 
1301 static struct net_proto_family caif_family_ops = {
1302 	.family = PF_CAIF,
1303 	.create = caif_create,
1304 	.owner = THIS_MODULE,
1305 };
1306 
1307 static int af_caif_init(void)
1308 {
1309 	int err;
1310 	err = sock_register(&caif_family_ops);
1311 
1312 	if (!err)
1313 		return err;
1314 
1315 	return 0;
1316 }
1317 
1318 static int __init caif_sktinit_module(void)
1319 {
1320 	int stat;
1321 #ifdef CONFIG_DEBUG_FS
1322 	debugfsdir = debugfs_create_dir("chnl_skt", NULL);
1323 	if (!IS_ERR(debugfsdir)) {
1324 		debugfs_create_u32("skb_inuse", S_IRUSR | S_IWUSR,
1325 				debugfsdir,
1326 				(u32 *) &cnt.skb_in_use);
1327 		debugfs_create_u32("skb_alloc", S_IRUSR | S_IWUSR,
1328 				debugfsdir,
1329 				(u32 *) &cnt.skb_alloc);
1330 		debugfs_create_u32("skb_free", S_IRUSR | S_IWUSR,
1331 				debugfsdir,
1332 				(u32 *) &cnt.skb_free);
1333 		debugfs_create_u32("num_sockets", S_IRUSR | S_IWUSR,
1334 				debugfsdir,
1335 				(u32 *) &caif_nr_socks);
1336 		debugfs_create_u32("num_open", S_IRUSR | S_IWUSR,
1337 				debugfsdir,
1338 				(u32 *) &cnt.num_open);
1339 		debugfs_create_u32("num_close", S_IRUSR | S_IWUSR,
1340 				debugfsdir,
1341 				(u32 *) &cnt.num_close);
1342 		debugfs_create_u32("num_init", S_IRUSR | S_IWUSR,
1343 				debugfsdir,
1344 				(u32 *) &cnt.num_init);
1345 		debugfs_create_u32("num_init_resp", S_IRUSR | S_IWUSR,
1346 				debugfsdir,
1347 				(u32 *) &cnt.num_init_resp);
1348 		debugfs_create_u32("num_init_fail_resp", S_IRUSR | S_IWUSR,
1349 				debugfsdir,
1350 				(u32 *) &cnt.num_init_fail_resp);
1351 		debugfs_create_u32("num_deinit", S_IRUSR | S_IWUSR,
1352 				debugfsdir,
1353 				(u32 *) &cnt.num_deinit);
1354 		debugfs_create_u32("num_deinit_resp", S_IRUSR | S_IWUSR,
1355 				debugfsdir,
1356 				(u32 *) &cnt.num_deinit_resp);
1357 		debugfs_create_u32("num_remote_shutdown_ind",
1358 				S_IRUSR | S_IWUSR, debugfsdir,
1359 				(u32 *) &cnt.num_remote_shutdown_ind);
1360 		debugfs_create_u32("num_tx_flow_off_ind", S_IRUSR | S_IWUSR,
1361 				debugfsdir,
1362 				(u32 *) &cnt.num_tx_flow_off_ind);
1363 		debugfs_create_u32("num_tx_flow_on_ind", S_IRUSR | S_IWUSR,
1364 				debugfsdir,
1365 				(u32 *) &cnt.num_tx_flow_on_ind);
1366 		debugfs_create_u32("num_rx_flow_off", S_IRUSR | S_IWUSR,
1367 				debugfsdir,
1368 				(u32 *) &cnt.num_rx_flow_off);
1369 		debugfs_create_u32("num_rx_flow_on", S_IRUSR | S_IWUSR,
1370 				debugfsdir,
1371 				(u32 *) &cnt.num_rx_flow_on);
1372 	}
1373 #endif
1374 	stat = af_caif_init();
1375 	if (stat) {
1376 		pr_err("CAIF: %s(): Failed to initialize CAIF socket layer.",
1377 		       __func__);
1378 		return stat;
1379 	}
1380 	return 0;
1381 }
1382 
1383 static void __exit caif_sktexit_module(void)
1384 {
1385 	sock_unregister(PF_CAIF);
1386 	if (debugfsdir != NULL)
1387 		debugfs_remove_recursive(debugfsdir);
1388 }
1389 
1390 module_init(caif_sktinit_module);
1391 module_exit(caif_sktexit_module);
1392