xref: /openbmc/linux/net/phonet/pep.c (revision 63dc02bd)
1 /*
2  * File: pep.c
3  *
4  * Phonet pipe protocol end point socket
5  *
6  * Copyright (C) 2008 Nokia Corporation.
7  *
8  * Author: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License
12  * version 2 as published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope that it will be useful, but
15  * WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  * General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
22  * 02110-1301 USA
23  */
24 
25 #include <linux/kernel.h>
26 #include <linux/slab.h>
27 #include <linux/socket.h>
28 #include <net/sock.h>
29 #include <net/tcp_states.h>
30 #include <asm/ioctls.h>
31 
32 #include <linux/phonet.h>
33 #include <linux/module.h>
34 #include <net/phonet/phonet.h>
35 #include <net/phonet/pep.h>
36 #include <net/phonet/gprs.h>
37 
38 /* sk_state values:
39  * TCP_CLOSE		sock not in use yet
40  * TCP_CLOSE_WAIT	disconnected pipe
41  * TCP_LISTEN		listening pipe endpoint
42  * TCP_SYN_RECV		connected pipe in disabled state
43  * TCP_ESTABLISHED	connected pipe in enabled state
44  *
45  * pep_sock locking:
46  *  - sk_state, hlist: sock lock needed
47  *  - listener: read only
48  *  - pipe_handle: read only
49  */
50 
51 #define CREDITS_MAX	10
52 #define CREDITS_THR	7
53 
54 #define pep_sb_size(s) (((s) + 5) & ~3) /* 2-bytes head, 32-bits aligned */
55 
56 /* Get the next TLV sub-block. */
57 static unsigned char *pep_get_sb(struct sk_buff *skb, u8 *ptype, u8 *plen,
58 					void *buf)
59 {
60 	void *data = NULL;
61 	struct {
62 		u8 sb_type;
63 		u8 sb_len;
64 	} *ph, h;
65 	int buflen = *plen;
66 
67 	ph = skb_header_pointer(skb, 0, 2, &h);
68 	if (ph == NULL || ph->sb_len < 2 || !pskb_may_pull(skb, ph->sb_len))
69 		return NULL;
70 	ph->sb_len -= 2;
71 	*ptype = ph->sb_type;
72 	*plen = ph->sb_len;
73 
74 	if (buflen > ph->sb_len)
75 		buflen = ph->sb_len;
76 	data = skb_header_pointer(skb, 2, buflen, buf);
77 	__skb_pull(skb, 2 + ph->sb_len);
78 	return data;
79 }
80 
81 static struct sk_buff *pep_alloc_skb(struct sock *sk, const void *payload,
82 					int len, gfp_t priority)
83 {
84 	struct sk_buff *skb = alloc_skb(MAX_PNPIPE_HEADER + len, priority);
85 	if (!skb)
86 		return NULL;
87 	skb_set_owner_w(skb, sk);
88 
89 	skb_reserve(skb, MAX_PNPIPE_HEADER);
90 	__skb_put(skb, len);
91 	skb_copy_to_linear_data(skb, payload, len);
92 	__skb_push(skb, sizeof(struct pnpipehdr));
93 	skb_reset_transport_header(skb);
94 	return skb;
95 }
96 
97 static int pep_reply(struct sock *sk, struct sk_buff *oskb, u8 code,
98 			const void *data, int len, gfp_t priority)
99 {
100 	const struct pnpipehdr *oph = pnp_hdr(oskb);
101 	struct pnpipehdr *ph;
102 	struct sk_buff *skb;
103 	struct sockaddr_pn peer;
104 
105 	skb = pep_alloc_skb(sk, data, len, priority);
106 	if (!skb)
107 		return -ENOMEM;
108 
109 	ph = pnp_hdr(skb);
110 	ph->utid = oph->utid;
111 	ph->message_id = oph->message_id + 1; /* REQ -> RESP */
112 	ph->pipe_handle = oph->pipe_handle;
113 	ph->error_code = code;
114 
115 	pn_skb_get_src_sockaddr(oskb, &peer);
116 	return pn_skb_send(sk, skb, &peer);
117 }
118 
119 static int pep_indicate(struct sock *sk, u8 id, u8 code,
120 			const void *data, int len, gfp_t priority)
121 {
122 	struct pep_sock *pn = pep_sk(sk);
123 	struct pnpipehdr *ph;
124 	struct sk_buff *skb;
125 
126 	skb = pep_alloc_skb(sk, data, len, priority);
127 	if (!skb)
128 		return -ENOMEM;
129 
130 	ph = pnp_hdr(skb);
131 	ph->utid = 0;
132 	ph->message_id = id;
133 	ph->pipe_handle = pn->pipe_handle;
134 	ph->data[0] = code;
135 	return pn_skb_send(sk, skb, NULL);
136 }
137 
138 #define PAD 0x00
139 
140 static int pipe_handler_request(struct sock *sk, u8 id, u8 code,
141 				const void *data, int len)
142 {
143 	struct pep_sock *pn = pep_sk(sk);
144 	struct pnpipehdr *ph;
145 	struct sk_buff *skb;
146 
147 	skb = pep_alloc_skb(sk, data, len, GFP_KERNEL);
148 	if (!skb)
149 		return -ENOMEM;
150 
151 	ph = pnp_hdr(skb);
152 	ph->utid = id; /* whatever */
153 	ph->message_id = id;
154 	ph->pipe_handle = pn->pipe_handle;
155 	ph->data[0] = code;
156 	return pn_skb_send(sk, skb, NULL);
157 }
158 
159 static int pipe_handler_send_created_ind(struct sock *sk)
160 {
161 	struct pep_sock *pn = pep_sk(sk);
162 	u8 data[4] = {
163 		PN_PIPE_SB_NEGOTIATED_FC, pep_sb_size(2),
164 		pn->tx_fc, pn->rx_fc,
165 	};
166 
167 	return pep_indicate(sk, PNS_PIPE_CREATED_IND, 1 /* sub-blocks */,
168 				data, 4, GFP_ATOMIC);
169 }
170 
171 static int pep_accept_conn(struct sock *sk, struct sk_buff *skb)
172 {
173 	static const u8 data[20] = {
174 		PAD, PAD, PAD, 2 /* sub-blocks */,
175 		PN_PIPE_SB_REQUIRED_FC_TX, pep_sb_size(5), 3, PAD,
176 			PN_MULTI_CREDIT_FLOW_CONTROL,
177 			PN_ONE_CREDIT_FLOW_CONTROL,
178 			PN_LEGACY_FLOW_CONTROL,
179 			PAD,
180 		PN_PIPE_SB_PREFERRED_FC_RX, pep_sb_size(5), 3, PAD,
181 			PN_MULTI_CREDIT_FLOW_CONTROL,
182 			PN_ONE_CREDIT_FLOW_CONTROL,
183 			PN_LEGACY_FLOW_CONTROL,
184 			PAD,
185 	};
186 
187 	might_sleep();
188 	return pep_reply(sk, skb, PN_PIPE_NO_ERROR, data, sizeof(data),
189 				GFP_KERNEL);
190 }
191 
192 static int pep_reject_conn(struct sock *sk, struct sk_buff *skb, u8 code,
193 				gfp_t priority)
194 {
195 	static const u8 data[4] = { PAD, PAD, PAD, 0 /* sub-blocks */ };
196 	WARN_ON(code == PN_PIPE_NO_ERROR);
197 	return pep_reply(sk, skb, code, data, sizeof(data), priority);
198 }
199 
200 /* Control requests are not sent by the pipe service and have a specific
201  * message format. */
202 static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code,
203 				gfp_t priority)
204 {
205 	const struct pnpipehdr *oph = pnp_hdr(oskb);
206 	struct sk_buff *skb;
207 	struct pnpipehdr *ph;
208 	struct sockaddr_pn dst;
209 	u8 data[4] = {
210 		oph->data[0], /* PEP type */
211 		code, /* error code, at an unusual offset */
212 		PAD, PAD,
213 	};
214 
215 	skb = pep_alloc_skb(sk, data, 4, priority);
216 	if (!skb)
217 		return -ENOMEM;
218 
219 	ph = pnp_hdr(skb);
220 	ph->utid = oph->utid;
221 	ph->message_id = PNS_PEP_CTRL_RESP;
222 	ph->pipe_handle = oph->pipe_handle;
223 	ph->data[0] = oph->data[1]; /* CTRL id */
224 
225 	pn_skb_get_src_sockaddr(oskb, &dst);
226 	return pn_skb_send(sk, skb, &dst);
227 }
228 
229 static int pipe_snd_status(struct sock *sk, u8 type, u8 status, gfp_t priority)
230 {
231 	u8 data[4] = { type, PAD, PAD, status };
232 
233 	return pep_indicate(sk, PNS_PEP_STATUS_IND, PN_PEP_TYPE_COMMON,
234 				data, 4, priority);
235 }
236 
237 /* Send our RX flow control information to the sender.
238  * Socket must be locked. */
239 static void pipe_grant_credits(struct sock *sk, gfp_t priority)
240 {
241 	struct pep_sock *pn = pep_sk(sk);
242 
243 	BUG_ON(sk->sk_state != TCP_ESTABLISHED);
244 
245 	switch (pn->rx_fc) {
246 	case PN_LEGACY_FLOW_CONTROL: /* TODO */
247 		break;
248 	case PN_ONE_CREDIT_FLOW_CONTROL:
249 		if (pipe_snd_status(sk, PN_PEP_IND_FLOW_CONTROL,
250 					PEP_IND_READY, priority) == 0)
251 			pn->rx_credits = 1;
252 		break;
253 	case PN_MULTI_CREDIT_FLOW_CONTROL:
254 		if ((pn->rx_credits + CREDITS_THR) > CREDITS_MAX)
255 			break;
256 		if (pipe_snd_status(sk, PN_PEP_IND_ID_MCFC_GRANT_CREDITS,
257 					CREDITS_MAX - pn->rx_credits,
258 					priority) == 0)
259 			pn->rx_credits = CREDITS_MAX;
260 		break;
261 	}
262 }
263 
264 static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
265 {
266 	struct pep_sock *pn = pep_sk(sk);
267 	struct pnpipehdr *hdr;
268 	int wake = 0;
269 
270 	if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
271 		return -EINVAL;
272 
273 	hdr = pnp_hdr(skb);
274 	if (hdr->data[0] != PN_PEP_TYPE_COMMON) {
275 		LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP type: %u\n",
276 				(unsigned)hdr->data[0]);
277 		return -EOPNOTSUPP;
278 	}
279 
280 	switch (hdr->data[1]) {
281 	case PN_PEP_IND_FLOW_CONTROL:
282 		switch (pn->tx_fc) {
283 		case PN_LEGACY_FLOW_CONTROL:
284 			switch (hdr->data[4]) {
285 			case PEP_IND_BUSY:
286 				atomic_set(&pn->tx_credits, 0);
287 				break;
288 			case PEP_IND_READY:
289 				atomic_set(&pn->tx_credits, wake = 1);
290 				break;
291 			}
292 			break;
293 		case PN_ONE_CREDIT_FLOW_CONTROL:
294 			if (hdr->data[4] == PEP_IND_READY)
295 				atomic_set(&pn->tx_credits, wake = 1);
296 			break;
297 		}
298 		break;
299 
300 	case PN_PEP_IND_ID_MCFC_GRANT_CREDITS:
301 		if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL)
302 			break;
303 		atomic_add(wake = hdr->data[4], &pn->tx_credits);
304 		break;
305 
306 	default:
307 		LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP indication: %u\n",
308 				(unsigned)hdr->data[1]);
309 		return -EOPNOTSUPP;
310 	}
311 	if (wake)
312 		sk->sk_write_space(sk);
313 	return 0;
314 }
315 
316 static int pipe_rcv_created(struct sock *sk, struct sk_buff *skb)
317 {
318 	struct pep_sock *pn = pep_sk(sk);
319 	struct pnpipehdr *hdr = pnp_hdr(skb);
320 	u8 n_sb = hdr->data[0];
321 
322 	pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
323 	__skb_pull(skb, sizeof(*hdr));
324 	while (n_sb > 0) {
325 		u8 type, buf[2], len = sizeof(buf);
326 		u8 *data = pep_get_sb(skb, &type, &len, buf);
327 
328 		if (data == NULL)
329 			return -EINVAL;
330 		switch (type) {
331 		case PN_PIPE_SB_NEGOTIATED_FC:
332 			if (len < 2 || (data[0] | data[1]) > 3)
333 				break;
334 			pn->tx_fc = data[0] & 3;
335 			pn->rx_fc = data[1] & 3;
336 			break;
337 		}
338 		n_sb--;
339 	}
340 	return 0;
341 }
342 
343 /* Queue an skb to a connected sock.
344  * Socket lock must be held. */
345 static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
346 {
347 	struct pep_sock *pn = pep_sk(sk);
348 	struct pnpipehdr *hdr = pnp_hdr(skb);
349 	struct sk_buff_head *queue;
350 	int err = 0;
351 
352 	BUG_ON(sk->sk_state == TCP_CLOSE_WAIT);
353 
354 	switch (hdr->message_id) {
355 	case PNS_PEP_CONNECT_REQ:
356 		pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, GFP_ATOMIC);
357 		break;
358 
359 	case PNS_PEP_DISCONNECT_REQ:
360 		pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
361 		sk->sk_state = TCP_CLOSE_WAIT;
362 		if (!sock_flag(sk, SOCK_DEAD))
363 			sk->sk_state_change(sk);
364 		break;
365 
366 	case PNS_PEP_ENABLE_REQ:
367 		/* Wait for PNS_PIPE_(ENABLED|REDIRECTED)_IND */
368 		pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
369 		break;
370 
371 	case PNS_PEP_RESET_REQ:
372 		switch (hdr->state_after_reset) {
373 		case PN_PIPE_DISABLE:
374 			pn->init_enable = 0;
375 			break;
376 		case PN_PIPE_ENABLE:
377 			pn->init_enable = 1;
378 			break;
379 		default: /* not allowed to send an error here!? */
380 			err = -EINVAL;
381 			goto out;
382 		}
383 		/* fall through */
384 	case PNS_PEP_DISABLE_REQ:
385 		atomic_set(&pn->tx_credits, 0);
386 		pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
387 		break;
388 
389 	case PNS_PEP_CTRL_REQ:
390 		if (skb_queue_len(&pn->ctrlreq_queue) >= PNPIPE_CTRLREQ_MAX) {
391 			atomic_inc(&sk->sk_drops);
392 			break;
393 		}
394 		__skb_pull(skb, 4);
395 		queue = &pn->ctrlreq_queue;
396 		goto queue;
397 
398 	case PNS_PIPE_ALIGNED_DATA:
399 		__skb_pull(skb, 1);
400 		/* fall through */
401 	case PNS_PIPE_DATA:
402 		__skb_pull(skb, 3); /* Pipe data header */
403 		if (!pn_flow_safe(pn->rx_fc)) {
404 			err = sock_queue_rcv_skb(sk, skb);
405 			if (!err)
406 				return NET_RX_SUCCESS;
407 			err = -ENOBUFS;
408 			break;
409 		}
410 
411 		if (pn->rx_credits == 0) {
412 			atomic_inc(&sk->sk_drops);
413 			err = -ENOBUFS;
414 			break;
415 		}
416 		pn->rx_credits--;
417 		queue = &sk->sk_receive_queue;
418 		goto queue;
419 
420 	case PNS_PEP_STATUS_IND:
421 		pipe_rcv_status(sk, skb);
422 		break;
423 
424 	case PNS_PIPE_REDIRECTED_IND:
425 		err = pipe_rcv_created(sk, skb);
426 		break;
427 
428 	case PNS_PIPE_CREATED_IND:
429 		err = pipe_rcv_created(sk, skb);
430 		if (err)
431 			break;
432 		/* fall through */
433 	case PNS_PIPE_RESET_IND:
434 		if (!pn->init_enable)
435 			break;
436 		/* fall through */
437 	case PNS_PIPE_ENABLED_IND:
438 		if (!pn_flow_safe(pn->tx_fc)) {
439 			atomic_set(&pn->tx_credits, 1);
440 			sk->sk_write_space(sk);
441 		}
442 		if (sk->sk_state == TCP_ESTABLISHED)
443 			break; /* Nothing to do */
444 		sk->sk_state = TCP_ESTABLISHED;
445 		pipe_grant_credits(sk, GFP_ATOMIC);
446 		break;
447 
448 	case PNS_PIPE_DISABLED_IND:
449 		sk->sk_state = TCP_SYN_RECV;
450 		pn->rx_credits = 0;
451 		break;
452 
453 	default:
454 		LIMIT_NETDEBUG(KERN_DEBUG"Phonet unknown PEP message: %u\n",
455 				hdr->message_id);
456 		err = -EINVAL;
457 	}
458 out:
459 	kfree_skb(skb);
460 	return (err == -ENOBUFS) ? NET_RX_DROP : NET_RX_SUCCESS;
461 
462 queue:
463 	skb->dev = NULL;
464 	skb_set_owner_r(skb, sk);
465 	err = skb->len;
466 	skb_queue_tail(queue, skb);
467 	if (!sock_flag(sk, SOCK_DEAD))
468 		sk->sk_data_ready(sk, err);
469 	return NET_RX_SUCCESS;
470 }
471 
472 /* Destroy connected sock. */
473 static void pipe_destruct(struct sock *sk)
474 {
475 	struct pep_sock *pn = pep_sk(sk);
476 
477 	skb_queue_purge(&sk->sk_receive_queue);
478 	skb_queue_purge(&pn->ctrlreq_queue);
479 }
480 
481 static u8 pipe_negotiate_fc(const u8 *fcs, unsigned n)
482 {
483 	unsigned i;
484 	u8 final_fc = PN_NO_FLOW_CONTROL;
485 
486 	for (i = 0; i < n; i++) {
487 		u8 fc = fcs[i];
488 
489 		if (fc > final_fc && fc < PN_MAX_FLOW_CONTROL)
490 			final_fc = fc;
491 	}
492 	return final_fc;
493 }
494 
495 static int pep_connresp_rcv(struct sock *sk, struct sk_buff *skb)
496 {
497 	struct pep_sock *pn = pep_sk(sk);
498 	struct pnpipehdr *hdr;
499 	u8 n_sb;
500 
501 	if (!pskb_pull(skb, sizeof(*hdr) + 4))
502 		return -EINVAL;
503 
504 	hdr = pnp_hdr(skb);
505 	if (hdr->error_code != PN_PIPE_NO_ERROR)
506 		return -ECONNREFUSED;
507 
508 	/* Parse sub-blocks */
509 	n_sb = hdr->data[4];
510 	while (n_sb > 0) {
511 		u8 type, buf[6], len = sizeof(buf);
512 		const u8 *data = pep_get_sb(skb, &type, &len, buf);
513 
514 		if (data == NULL)
515 			return -EINVAL;
516 
517 		switch (type) {
518 		case PN_PIPE_SB_REQUIRED_FC_TX:
519 			if (len < 2 || len < data[0])
520 				break;
521 			pn->tx_fc = pipe_negotiate_fc(data + 2, len - 2);
522 			break;
523 
524 		case PN_PIPE_SB_PREFERRED_FC_RX:
525 			if (len < 2 || len < data[0])
526 				break;
527 			pn->rx_fc = pipe_negotiate_fc(data + 2, len - 2);
528 			break;
529 
530 		}
531 		n_sb--;
532 	}
533 
534 	return pipe_handler_send_created_ind(sk);
535 }
536 
537 static int pep_enableresp_rcv(struct sock *sk, struct sk_buff *skb)
538 {
539 	struct pnpipehdr *hdr = pnp_hdr(skb);
540 
541 	if (hdr->error_code != PN_PIPE_NO_ERROR)
542 		return -ECONNREFUSED;
543 
544 	return pep_indicate(sk, PNS_PIPE_ENABLED_IND, 0 /* sub-blocks */,
545 		NULL, 0, GFP_ATOMIC);
546 
547 }
548 
549 static void pipe_start_flow_control(struct sock *sk)
550 {
551 	struct pep_sock *pn = pep_sk(sk);
552 
553 	if (!pn_flow_safe(pn->tx_fc)) {
554 		atomic_set(&pn->tx_credits, 1);
555 		sk->sk_write_space(sk);
556 	}
557 	pipe_grant_credits(sk, GFP_ATOMIC);
558 }
559 
560 /* Queue an skb to an actively connected sock.
561  * Socket lock must be held. */
562 static int pipe_handler_do_rcv(struct sock *sk, struct sk_buff *skb)
563 {
564 	struct pep_sock *pn = pep_sk(sk);
565 	struct pnpipehdr *hdr = pnp_hdr(skb);
566 	int err = NET_RX_SUCCESS;
567 
568 	switch (hdr->message_id) {
569 	case PNS_PIPE_ALIGNED_DATA:
570 		__skb_pull(skb, 1);
571 		/* fall through */
572 	case PNS_PIPE_DATA:
573 		__skb_pull(skb, 3); /* Pipe data header */
574 		if (!pn_flow_safe(pn->rx_fc)) {
575 			err = sock_queue_rcv_skb(sk, skb);
576 			if (!err)
577 				return NET_RX_SUCCESS;
578 			err = NET_RX_DROP;
579 			break;
580 		}
581 
582 		if (pn->rx_credits == 0) {
583 			atomic_inc(&sk->sk_drops);
584 			err = NET_RX_DROP;
585 			break;
586 		}
587 		pn->rx_credits--;
588 		skb->dev = NULL;
589 		skb_set_owner_r(skb, sk);
590 		err = skb->len;
591 		skb_queue_tail(&sk->sk_receive_queue, skb);
592 		if (!sock_flag(sk, SOCK_DEAD))
593 			sk->sk_data_ready(sk, err);
594 		return NET_RX_SUCCESS;
595 
596 	case PNS_PEP_CONNECT_RESP:
597 		if (sk->sk_state != TCP_SYN_SENT)
598 			break;
599 		if (!sock_flag(sk, SOCK_DEAD))
600 			sk->sk_state_change(sk);
601 		if (pep_connresp_rcv(sk, skb)) {
602 			sk->sk_state = TCP_CLOSE_WAIT;
603 			break;
604 		}
605 		if (pn->init_enable == PN_PIPE_DISABLE)
606 			sk->sk_state = TCP_SYN_RECV;
607 		else {
608 			sk->sk_state = TCP_ESTABLISHED;
609 			pipe_start_flow_control(sk);
610 		}
611 		break;
612 
613 	case PNS_PEP_ENABLE_RESP:
614 		if (sk->sk_state != TCP_SYN_SENT)
615 			break;
616 
617 		if (pep_enableresp_rcv(sk, skb)) {
618 			sk->sk_state = TCP_CLOSE_WAIT;
619 			break;
620 		}
621 
622 		sk->sk_state = TCP_ESTABLISHED;
623 		pipe_start_flow_control(sk);
624 		break;
625 
626 	case PNS_PEP_DISCONNECT_RESP:
627 		/* sock should already be dead, nothing to do */
628 		break;
629 
630 	case PNS_PEP_STATUS_IND:
631 		pipe_rcv_status(sk, skb);
632 		break;
633 	}
634 	kfree_skb(skb);
635 	return err;
636 }
637 
638 /* Listening sock must be locked */
639 static struct sock *pep_find_pipe(const struct hlist_head *hlist,
640 					const struct sockaddr_pn *dst,
641 					u8 pipe_handle)
642 {
643 	struct hlist_node *node;
644 	struct sock *sknode;
645 	u16 dobj = pn_sockaddr_get_object(dst);
646 
647 	sk_for_each(sknode, node, hlist) {
648 		struct pep_sock *pnnode = pep_sk(sknode);
649 
650 		/* Ports match, but addresses might not: */
651 		if (pnnode->pn_sk.sobject != dobj)
652 			continue;
653 		if (pnnode->pipe_handle != pipe_handle)
654 			continue;
655 		if (sknode->sk_state == TCP_CLOSE_WAIT)
656 			continue;
657 
658 		sock_hold(sknode);
659 		return sknode;
660 	}
661 	return NULL;
662 }
663 
664 /*
665  * Deliver an skb to a listening sock.
666  * Socket lock must be held.
667  * We then queue the skb to the right connected sock (if any).
668  */
669 static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
670 {
671 	struct pep_sock *pn = pep_sk(sk);
672 	struct sock *sknode;
673 	struct pnpipehdr *hdr;
674 	struct sockaddr_pn dst;
675 	u8 pipe_handle;
676 
677 	if (!pskb_may_pull(skb, sizeof(*hdr)))
678 		goto drop;
679 
680 	hdr = pnp_hdr(skb);
681 	pipe_handle = hdr->pipe_handle;
682 	if (pipe_handle == PN_PIPE_INVALID_HANDLE)
683 		goto drop;
684 
685 	pn_skb_get_dst_sockaddr(skb, &dst);
686 
687 	/* Look for an existing pipe handle */
688 	sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
689 	if (sknode)
690 		return sk_receive_skb(sknode, skb, 1);
691 
692 	switch (hdr->message_id) {
693 	case PNS_PEP_CONNECT_REQ:
694 		if (sk->sk_state != TCP_LISTEN || sk_acceptq_is_full(sk)) {
695 			pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE,
696 					GFP_ATOMIC);
697 			break;
698 		}
699 		skb_queue_head(&sk->sk_receive_queue, skb);
700 		sk_acceptq_added(sk);
701 		if (!sock_flag(sk, SOCK_DEAD))
702 			sk->sk_data_ready(sk, 0);
703 		return NET_RX_SUCCESS;
704 
705 	case PNS_PEP_DISCONNECT_REQ:
706 		pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
707 		break;
708 
709 	case PNS_PEP_CTRL_REQ:
710 		pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
711 		break;
712 
713 	case PNS_PEP_RESET_REQ:
714 	case PNS_PEP_ENABLE_REQ:
715 	case PNS_PEP_DISABLE_REQ:
716 		/* invalid handle is not even allowed here! */
717 		break;
718 
719 	default:
720 		if ((1 << sk->sk_state)
721 				& ~(TCPF_CLOSE|TCPF_LISTEN|TCPF_CLOSE_WAIT))
722 			/* actively connected socket */
723 			return pipe_handler_do_rcv(sk, skb);
724 	}
725 drop:
726 	kfree_skb(skb);
727 	return NET_RX_SUCCESS;
728 }
729 
730 static int pipe_do_remove(struct sock *sk)
731 {
732 	struct pep_sock *pn = pep_sk(sk);
733 	struct pnpipehdr *ph;
734 	struct sk_buff *skb;
735 
736 	skb = pep_alloc_skb(sk, NULL, 0, GFP_KERNEL);
737 	if (!skb)
738 		return -ENOMEM;
739 
740 	ph = pnp_hdr(skb);
741 	ph->utid = 0;
742 	ph->message_id = PNS_PIPE_REMOVE_REQ;
743 	ph->pipe_handle = pn->pipe_handle;
744 	ph->data[0] = PAD;
745 	return pn_skb_send(sk, skb, NULL);
746 }
747 
748 /* associated socket ceases to exist */
749 static void pep_sock_close(struct sock *sk, long timeout)
750 {
751 	struct pep_sock *pn = pep_sk(sk);
752 	int ifindex = 0;
753 
754 	sock_hold(sk); /* keep a reference after sk_common_release() */
755 	sk_common_release(sk);
756 
757 	lock_sock(sk);
758 	if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED)) {
759 		if (sk->sk_backlog_rcv == pipe_do_rcv)
760 			/* Forcefully remove dangling Phonet pipe */
761 			pipe_do_remove(sk);
762 		else
763 			pipe_handler_request(sk, PNS_PEP_DISCONNECT_REQ, PAD,
764 						NULL, 0);
765 	}
766 	sk->sk_state = TCP_CLOSE;
767 
768 	ifindex = pn->ifindex;
769 	pn->ifindex = 0;
770 	release_sock(sk);
771 
772 	if (ifindex)
773 		gprs_detach(sk);
774 	sock_put(sk);
775 }
776 
777 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
778 {
779 	struct pep_sock *pn = pep_sk(sk), *newpn;
780 	struct sock *newsk = NULL;
781 	struct sk_buff *skb;
782 	struct pnpipehdr *hdr;
783 	struct sockaddr_pn dst, src;
784 	int err;
785 	u16 peer_type;
786 	u8 pipe_handle, enabled, n_sb;
787 	u8 aligned = 0;
788 
789 	skb = skb_recv_datagram(sk, 0, flags & O_NONBLOCK, errp);
790 	if (!skb)
791 		return NULL;
792 
793 	lock_sock(sk);
794 	if (sk->sk_state != TCP_LISTEN) {
795 		err = -EINVAL;
796 		goto drop;
797 	}
798 	sk_acceptq_removed(sk);
799 
800 	err = -EPROTO;
801 	if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
802 		goto drop;
803 
804 	hdr = pnp_hdr(skb);
805 	pipe_handle = hdr->pipe_handle;
806 	switch (hdr->state_after_connect) {
807 	case PN_PIPE_DISABLE:
808 		enabled = 0;
809 		break;
810 	case PN_PIPE_ENABLE:
811 		enabled = 1;
812 		break;
813 	default:
814 		pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM,
815 				GFP_KERNEL);
816 		goto drop;
817 	}
818 	peer_type = hdr->other_pep_type << 8;
819 
820 	/* Parse sub-blocks (options) */
821 	n_sb = hdr->data[4];
822 	while (n_sb > 0) {
823 		u8 type, buf[1], len = sizeof(buf);
824 		const u8 *data = pep_get_sb(skb, &type, &len, buf);
825 
826 		if (data == NULL)
827 			goto drop;
828 		switch (type) {
829 		case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
830 			if (len < 1)
831 				goto drop;
832 			peer_type = (peer_type & 0xff00) | data[0];
833 			break;
834 		case PN_PIPE_SB_ALIGNED_DATA:
835 			aligned = data[0] != 0;
836 			break;
837 		}
838 		n_sb--;
839 	}
840 
841 	/* Check for duplicate pipe handle */
842 	newsk = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
843 	if (unlikely(newsk)) {
844 		__sock_put(newsk);
845 		newsk = NULL;
846 		pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, GFP_KERNEL);
847 		goto drop;
848 	}
849 
850 	/* Create a new to-be-accepted sock */
851 	newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_KERNEL, sk->sk_prot);
852 	if (!newsk) {
853 		pep_reject_conn(sk, skb, PN_PIPE_ERR_OVERLOAD, GFP_KERNEL);
854 		err = -ENOBUFS;
855 		goto drop;
856 	}
857 
858 	sock_init_data(NULL, newsk);
859 	newsk->sk_state = TCP_SYN_RECV;
860 	newsk->sk_backlog_rcv = pipe_do_rcv;
861 	newsk->sk_protocol = sk->sk_protocol;
862 	newsk->sk_destruct = pipe_destruct;
863 
864 	newpn = pep_sk(newsk);
865 	pn_skb_get_dst_sockaddr(skb, &dst);
866 	pn_skb_get_src_sockaddr(skb, &src);
867 	newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
868 	newpn->pn_sk.dobject = pn_sockaddr_get_object(&src);
869 	newpn->pn_sk.resource = pn_sockaddr_get_resource(&dst);
870 	sock_hold(sk);
871 	newpn->listener = sk;
872 	skb_queue_head_init(&newpn->ctrlreq_queue);
873 	newpn->pipe_handle = pipe_handle;
874 	atomic_set(&newpn->tx_credits, 0);
875 	newpn->ifindex = 0;
876 	newpn->peer_type = peer_type;
877 	newpn->rx_credits = 0;
878 	newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
879 	newpn->init_enable = enabled;
880 	newpn->aligned = aligned;
881 
882 	err = pep_accept_conn(newsk, skb);
883 	if (err) {
884 		sock_put(newsk);
885 		newsk = NULL;
886 		goto drop;
887 	}
888 	sk_add_node(newsk, &pn->hlist);
889 drop:
890 	release_sock(sk);
891 	kfree_skb(skb);
892 	*errp = err;
893 	return newsk;
894 }
895 
896 static int pep_sock_connect(struct sock *sk, struct sockaddr *addr, int len)
897 {
898 	struct pep_sock *pn = pep_sk(sk);
899 	int err;
900 	u8 data[4] = { 0 /* sub-blocks */, PAD, PAD, PAD };
901 
902 	if (pn->pipe_handle == PN_PIPE_INVALID_HANDLE)
903 		pn->pipe_handle = 1; /* anything but INVALID_HANDLE */
904 
905 	err = pipe_handler_request(sk, PNS_PEP_CONNECT_REQ,
906 				pn->init_enable, data, 4);
907 	if (err) {
908 		pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
909 		return err;
910 	}
911 
912 	sk->sk_state = TCP_SYN_SENT;
913 
914 	return 0;
915 }
916 
917 static int pep_sock_enable(struct sock *sk, struct sockaddr *addr, int len)
918 {
919 	int err;
920 
921 	err = pipe_handler_request(sk, PNS_PEP_ENABLE_REQ, PAD,
922 				NULL, 0);
923 	if (err)
924 		return err;
925 
926 	sk->sk_state = TCP_SYN_SENT;
927 
928 	return 0;
929 }
930 
931 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
932 {
933 	struct pep_sock *pn = pep_sk(sk);
934 	int answ;
935 	int ret = -ENOIOCTLCMD;
936 
937 	switch (cmd) {
938 	case SIOCINQ:
939 		if (sk->sk_state == TCP_LISTEN) {
940 			ret = -EINVAL;
941 			break;
942 		}
943 
944 		lock_sock(sk);
945 		if (sock_flag(sk, SOCK_URGINLINE) &&
946 		    !skb_queue_empty(&pn->ctrlreq_queue))
947 			answ = skb_peek(&pn->ctrlreq_queue)->len;
948 		else if (!skb_queue_empty(&sk->sk_receive_queue))
949 			answ = skb_peek(&sk->sk_receive_queue)->len;
950 		else
951 			answ = 0;
952 		release_sock(sk);
953 		ret = put_user(answ, (int __user *)arg);
954 		break;
955 
956 	case SIOCPNENABLEPIPE:
957 		lock_sock(sk);
958 		if (sk->sk_state == TCP_SYN_SENT)
959 			ret =  -EBUSY;
960 		else if (sk->sk_state == TCP_ESTABLISHED)
961 			ret = -EISCONN;
962 		else
963 			ret = pep_sock_enable(sk, NULL, 0);
964 		release_sock(sk);
965 		break;
966 	}
967 
968 	return ret;
969 }
970 
971 static int pep_init(struct sock *sk)
972 {
973 	struct pep_sock *pn = pep_sk(sk);
974 
975 	sk->sk_destruct = pipe_destruct;
976 	INIT_HLIST_HEAD(&pn->hlist);
977 	pn->listener = NULL;
978 	skb_queue_head_init(&pn->ctrlreq_queue);
979 	atomic_set(&pn->tx_credits, 0);
980 	pn->ifindex = 0;
981 	pn->peer_type = 0;
982 	pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
983 	pn->rx_credits = 0;
984 	pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
985 	pn->init_enable = 1;
986 	pn->aligned = 0;
987 	return 0;
988 }
989 
990 static int pep_setsockopt(struct sock *sk, int level, int optname,
991 				char __user *optval, unsigned int optlen)
992 {
993 	struct pep_sock *pn = pep_sk(sk);
994 	int val = 0, err = 0;
995 
996 	if (level != SOL_PNPIPE)
997 		return -ENOPROTOOPT;
998 	if (optlen >= sizeof(int)) {
999 		if (get_user(val, (int __user *) optval))
1000 			return -EFAULT;
1001 	}
1002 
1003 	lock_sock(sk);
1004 	switch (optname) {
1005 	case PNPIPE_ENCAP:
1006 		if (val && val != PNPIPE_ENCAP_IP) {
1007 			err = -EINVAL;
1008 			break;
1009 		}
1010 		if (!pn->ifindex == !val)
1011 			break; /* Nothing to do! */
1012 		if (!capable(CAP_NET_ADMIN)) {
1013 			err = -EPERM;
1014 			break;
1015 		}
1016 		if (val) {
1017 			release_sock(sk);
1018 			err = gprs_attach(sk);
1019 			if (err > 0) {
1020 				pn->ifindex = err;
1021 				err = 0;
1022 			}
1023 		} else {
1024 			pn->ifindex = 0;
1025 			release_sock(sk);
1026 			gprs_detach(sk);
1027 			err = 0;
1028 		}
1029 		goto out_norel;
1030 
1031 	case PNPIPE_HANDLE:
1032 		if ((sk->sk_state == TCP_CLOSE) &&
1033 			(val >= 0) && (val < PN_PIPE_INVALID_HANDLE))
1034 			pn->pipe_handle = val;
1035 		else
1036 			err = -EINVAL;
1037 		break;
1038 
1039 	case PNPIPE_INITSTATE:
1040 		pn->init_enable = !!val;
1041 		break;
1042 
1043 	default:
1044 		err = -ENOPROTOOPT;
1045 	}
1046 	release_sock(sk);
1047 
1048 out_norel:
1049 	return err;
1050 }
1051 
1052 static int pep_getsockopt(struct sock *sk, int level, int optname,
1053 				char __user *optval, int __user *optlen)
1054 {
1055 	struct pep_sock *pn = pep_sk(sk);
1056 	int len, val;
1057 
1058 	if (level != SOL_PNPIPE)
1059 		return -ENOPROTOOPT;
1060 	if (get_user(len, optlen))
1061 		return -EFAULT;
1062 
1063 	switch (optname) {
1064 	case PNPIPE_ENCAP:
1065 		val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
1066 		break;
1067 
1068 	case PNPIPE_IFINDEX:
1069 		val = pn->ifindex;
1070 		break;
1071 
1072 	case PNPIPE_HANDLE:
1073 		val = pn->pipe_handle;
1074 		if (val == PN_PIPE_INVALID_HANDLE)
1075 			return -EINVAL;
1076 		break;
1077 
1078 	case PNPIPE_INITSTATE:
1079 		val = pn->init_enable;
1080 		break;
1081 
1082 	default:
1083 		return -ENOPROTOOPT;
1084 	}
1085 
1086 	len = min_t(unsigned int, sizeof(int), len);
1087 	if (put_user(len, optlen))
1088 		return -EFAULT;
1089 	if (put_user(val, (int __user *) optval))
1090 		return -EFAULT;
1091 	return 0;
1092 }
1093 
1094 static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
1095 {
1096 	struct pep_sock *pn = pep_sk(sk);
1097 	struct pnpipehdr *ph;
1098 	int err;
1099 
1100 	if (pn_flow_safe(pn->tx_fc) &&
1101 	    !atomic_add_unless(&pn->tx_credits, -1, 0)) {
1102 		kfree_skb(skb);
1103 		return -ENOBUFS;
1104 	}
1105 
1106 	skb_push(skb, 3 + pn->aligned);
1107 	skb_reset_transport_header(skb);
1108 	ph = pnp_hdr(skb);
1109 	ph->utid = 0;
1110 	if (pn->aligned) {
1111 		ph->message_id = PNS_PIPE_ALIGNED_DATA;
1112 		ph->data[0] = 0; /* padding */
1113 	} else
1114 		ph->message_id = PNS_PIPE_DATA;
1115 	ph->pipe_handle = pn->pipe_handle;
1116 	err = pn_skb_send(sk, skb, NULL);
1117 
1118 	if (err && pn_flow_safe(pn->tx_fc))
1119 		atomic_inc(&pn->tx_credits);
1120 	return err;
1121 
1122 }
1123 
1124 static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
1125 			struct msghdr *msg, size_t len)
1126 {
1127 	struct pep_sock *pn = pep_sk(sk);
1128 	struct sk_buff *skb;
1129 	long timeo;
1130 	int flags = msg->msg_flags;
1131 	int err, done;
1132 
1133 	if (len > USHRT_MAX)
1134 		return -EMSGSIZE;
1135 
1136 	if ((msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|
1137 				MSG_CMSG_COMPAT)) ||
1138 			!(msg->msg_flags & MSG_EOR))
1139 		return -EOPNOTSUPP;
1140 
1141 	skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
1142 					flags & MSG_DONTWAIT, &err);
1143 	if (!skb)
1144 		return err;
1145 
1146 	skb_reserve(skb, MAX_PHONET_HEADER + 3 + pn->aligned);
1147 	err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1148 	if (err < 0)
1149 		goto outfree;
1150 
1151 	lock_sock(sk);
1152 	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
1153 	if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
1154 		err = -ENOTCONN;
1155 		goto out;
1156 	}
1157 	if (sk->sk_state != TCP_ESTABLISHED) {
1158 		/* Wait until the pipe gets to enabled state */
1159 disabled:
1160 		err = sk_stream_wait_connect(sk, &timeo);
1161 		if (err)
1162 			goto out;
1163 
1164 		if (sk->sk_state == TCP_CLOSE_WAIT) {
1165 			err = -ECONNRESET;
1166 			goto out;
1167 		}
1168 	}
1169 	BUG_ON(sk->sk_state != TCP_ESTABLISHED);
1170 
1171 	/* Wait until flow control allows TX */
1172 	done = atomic_read(&pn->tx_credits);
1173 	while (!done) {
1174 		DEFINE_WAIT(wait);
1175 
1176 		if (!timeo) {
1177 			err = -EAGAIN;
1178 			goto out;
1179 		}
1180 		if (signal_pending(current)) {
1181 			err = sock_intr_errno(timeo);
1182 			goto out;
1183 		}
1184 
1185 		prepare_to_wait(sk_sleep(sk), &wait,
1186 				TASK_INTERRUPTIBLE);
1187 		done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits));
1188 		finish_wait(sk_sleep(sk), &wait);
1189 
1190 		if (sk->sk_state != TCP_ESTABLISHED)
1191 			goto disabled;
1192 	}
1193 
1194 	err = pipe_skb_send(sk, skb);
1195 	if (err >= 0)
1196 		err = len; /* success! */
1197 	skb = NULL;
1198 out:
1199 	release_sock(sk);
1200 outfree:
1201 	kfree_skb(skb);
1202 	return err;
1203 }
1204 
1205 int pep_writeable(struct sock *sk)
1206 {
1207 	struct pep_sock *pn = pep_sk(sk);
1208 
1209 	return atomic_read(&pn->tx_credits);
1210 }
1211 
1212 int pep_write(struct sock *sk, struct sk_buff *skb)
1213 {
1214 	struct sk_buff *rskb, *fs;
1215 	int flen = 0;
1216 
1217 	if (pep_sk(sk)->aligned)
1218 		return pipe_skb_send(sk, skb);
1219 
1220 	rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
1221 	if (!rskb) {
1222 		kfree_skb(skb);
1223 		return -ENOMEM;
1224 	}
1225 	skb_shinfo(rskb)->frag_list = skb;
1226 	rskb->len += skb->len;
1227 	rskb->data_len += rskb->len;
1228 	rskb->truesize += rskb->len;
1229 
1230 	/* Avoid nested fragments */
1231 	skb_walk_frags(skb, fs)
1232 		flen += fs->len;
1233 	skb->next = skb_shinfo(skb)->frag_list;
1234 	skb_frag_list_init(skb);
1235 	skb->len -= flen;
1236 	skb->data_len -= flen;
1237 	skb->truesize -= flen;
1238 
1239 	skb_reserve(rskb, MAX_PHONET_HEADER + 3);
1240 	return pipe_skb_send(sk, rskb);
1241 }
1242 
1243 struct sk_buff *pep_read(struct sock *sk)
1244 {
1245 	struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
1246 
1247 	if (sk->sk_state == TCP_ESTABLISHED)
1248 		pipe_grant_credits(sk, GFP_ATOMIC);
1249 	return skb;
1250 }
1251 
1252 static int pep_recvmsg(struct kiocb *iocb, struct sock *sk,
1253 			struct msghdr *msg, size_t len, int noblock,
1254 			int flags, int *addr_len)
1255 {
1256 	struct sk_buff *skb;
1257 	int err;
1258 
1259 	if (flags & ~(MSG_OOB|MSG_PEEK|MSG_TRUNC|MSG_DONTWAIT|MSG_WAITALL|
1260 			MSG_NOSIGNAL|MSG_CMSG_COMPAT))
1261 		return -EOPNOTSUPP;
1262 
1263 	if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
1264 		return -ENOTCONN;
1265 
1266 	if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
1267 		/* Dequeue and acknowledge control request */
1268 		struct pep_sock *pn = pep_sk(sk);
1269 
1270 		if (flags & MSG_PEEK)
1271 			return -EOPNOTSUPP;
1272 		skb = skb_dequeue(&pn->ctrlreq_queue);
1273 		if (skb) {
1274 			pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
1275 						GFP_KERNEL);
1276 			msg->msg_flags |= MSG_OOB;
1277 			goto copy;
1278 		}
1279 		if (flags & MSG_OOB)
1280 			return -EINVAL;
1281 	}
1282 
1283 	skb = skb_recv_datagram(sk, flags, noblock, &err);
1284 	lock_sock(sk);
1285 	if (skb == NULL) {
1286 		if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
1287 			err = -ECONNRESET;
1288 		release_sock(sk);
1289 		return err;
1290 	}
1291 
1292 	if (sk->sk_state == TCP_ESTABLISHED)
1293 		pipe_grant_credits(sk, GFP_KERNEL);
1294 	release_sock(sk);
1295 copy:
1296 	msg->msg_flags |= MSG_EOR;
1297 	if (skb->len > len)
1298 		msg->msg_flags |= MSG_TRUNC;
1299 	else
1300 		len = skb->len;
1301 
1302 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len);
1303 	if (!err)
1304 		err = (flags & MSG_TRUNC) ? skb->len : len;
1305 
1306 	skb_free_datagram(sk, skb);
1307 	return err;
1308 }
1309 
1310 static void pep_sock_unhash(struct sock *sk)
1311 {
1312 	struct pep_sock *pn = pep_sk(sk);
1313 	struct sock *skparent = NULL;
1314 
1315 	lock_sock(sk);
1316 
1317 	if (pn->listener != NULL) {
1318 		skparent = pn->listener;
1319 		pn->listener = NULL;
1320 		release_sock(sk);
1321 
1322 		pn = pep_sk(skparent);
1323 		lock_sock(skparent);
1324 		sk_del_node_init(sk);
1325 		sk = skparent;
1326 	}
1327 
1328 	/* Unhash a listening sock only when it is closed
1329 	 * and all of its active connected pipes are closed. */
1330 	if (hlist_empty(&pn->hlist))
1331 		pn_sock_unhash(&pn->pn_sk.sk);
1332 	release_sock(sk);
1333 
1334 	if (skparent)
1335 		sock_put(skparent);
1336 }
1337 
1338 static struct proto pep_proto = {
1339 	.close		= pep_sock_close,
1340 	.accept		= pep_sock_accept,
1341 	.connect	= pep_sock_connect,
1342 	.ioctl		= pep_ioctl,
1343 	.init		= pep_init,
1344 	.setsockopt	= pep_setsockopt,
1345 	.getsockopt	= pep_getsockopt,
1346 	.sendmsg	= pep_sendmsg,
1347 	.recvmsg	= pep_recvmsg,
1348 	.backlog_rcv	= pep_do_rcv,
1349 	.hash		= pn_sock_hash,
1350 	.unhash		= pep_sock_unhash,
1351 	.get_port	= pn_sock_get_port,
1352 	.obj_size	= sizeof(struct pep_sock),
1353 	.owner		= THIS_MODULE,
1354 	.name		= "PNPIPE",
1355 };
1356 
1357 static struct phonet_protocol pep_pn_proto = {
1358 	.ops		= &phonet_stream_ops,
1359 	.prot		= &pep_proto,
1360 	.sock_type	= SOCK_SEQPACKET,
1361 };
1362 
1363 static int __init pep_register(void)
1364 {
1365 	return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1366 }
1367 
1368 static void __exit pep_unregister(void)
1369 {
1370 	phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
1371 }
1372 
1373 module_init(pep_register);
1374 module_exit(pep_unregister);
1375 MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
1376 MODULE_DESCRIPTION("Phonet pipe protocol");
1377 MODULE_LICENSE("GPL");
1378 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);
1379