xref: /openbmc/linux/net/phonet/pep.c (revision 4161b450)
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
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 		net_dbg_ratelimited("Phonet unknown PEP type: %u\n",
276 				    (unsigned int)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 		net_dbg_ratelimited("Phonet unknown PEP indication: %u\n",
308 				    (unsigned int)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 		net_dbg_ratelimited("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 	skb_queue_tail(queue, skb);
466 	if (!sock_flag(sk, SOCK_DEAD))
467 		sk->sk_data_ready(sk);
468 	return NET_RX_SUCCESS;
469 }
470 
471 /* Destroy connected sock. */
472 static void pipe_destruct(struct sock *sk)
473 {
474 	struct pep_sock *pn = pep_sk(sk);
475 
476 	skb_queue_purge(&sk->sk_receive_queue);
477 	skb_queue_purge(&pn->ctrlreq_queue);
478 }
479 
480 static u8 pipe_negotiate_fc(const u8 *fcs, unsigned int n)
481 {
482 	unsigned int i;
483 	u8 final_fc = PN_NO_FLOW_CONTROL;
484 
485 	for (i = 0; i < n; i++) {
486 		u8 fc = fcs[i];
487 
488 		if (fc > final_fc && fc < PN_MAX_FLOW_CONTROL)
489 			final_fc = fc;
490 	}
491 	return final_fc;
492 }
493 
494 static int pep_connresp_rcv(struct sock *sk, struct sk_buff *skb)
495 {
496 	struct pep_sock *pn = pep_sk(sk);
497 	struct pnpipehdr *hdr;
498 	u8 n_sb;
499 
500 	if (!pskb_pull(skb, sizeof(*hdr) + 4))
501 		return -EINVAL;
502 
503 	hdr = pnp_hdr(skb);
504 	if (hdr->error_code != PN_PIPE_NO_ERROR)
505 		return -ECONNREFUSED;
506 
507 	/* Parse sub-blocks */
508 	n_sb = hdr->data[4];
509 	while (n_sb > 0) {
510 		u8 type, buf[6], len = sizeof(buf);
511 		const u8 *data = pep_get_sb(skb, &type, &len, buf);
512 
513 		if (data == NULL)
514 			return -EINVAL;
515 
516 		switch (type) {
517 		case PN_PIPE_SB_REQUIRED_FC_TX:
518 			if (len < 2 || len < data[0])
519 				break;
520 			pn->tx_fc = pipe_negotiate_fc(data + 2, len - 2);
521 			break;
522 
523 		case PN_PIPE_SB_PREFERRED_FC_RX:
524 			if (len < 2 || len < data[0])
525 				break;
526 			pn->rx_fc = pipe_negotiate_fc(data + 2, len - 2);
527 			break;
528 
529 		}
530 		n_sb--;
531 	}
532 
533 	return pipe_handler_send_created_ind(sk);
534 }
535 
536 static int pep_enableresp_rcv(struct sock *sk, struct sk_buff *skb)
537 {
538 	struct pnpipehdr *hdr = pnp_hdr(skb);
539 
540 	if (hdr->error_code != PN_PIPE_NO_ERROR)
541 		return -ECONNREFUSED;
542 
543 	return pep_indicate(sk, PNS_PIPE_ENABLED_IND, 0 /* sub-blocks */,
544 		NULL, 0, GFP_ATOMIC);
545 
546 }
547 
548 static void pipe_start_flow_control(struct sock *sk)
549 {
550 	struct pep_sock *pn = pep_sk(sk);
551 
552 	if (!pn_flow_safe(pn->tx_fc)) {
553 		atomic_set(&pn->tx_credits, 1);
554 		sk->sk_write_space(sk);
555 	}
556 	pipe_grant_credits(sk, GFP_ATOMIC);
557 }
558 
559 /* Queue an skb to an actively connected sock.
560  * Socket lock must be held. */
561 static int pipe_handler_do_rcv(struct sock *sk, struct sk_buff *skb)
562 {
563 	struct pep_sock *pn = pep_sk(sk);
564 	struct pnpipehdr *hdr = pnp_hdr(skb);
565 	int err = NET_RX_SUCCESS;
566 
567 	switch (hdr->message_id) {
568 	case PNS_PIPE_ALIGNED_DATA:
569 		__skb_pull(skb, 1);
570 		/* fall through */
571 	case PNS_PIPE_DATA:
572 		__skb_pull(skb, 3); /* Pipe data header */
573 		if (!pn_flow_safe(pn->rx_fc)) {
574 			err = sock_queue_rcv_skb(sk, skb);
575 			if (!err)
576 				return NET_RX_SUCCESS;
577 			err = NET_RX_DROP;
578 			break;
579 		}
580 
581 		if (pn->rx_credits == 0) {
582 			atomic_inc(&sk->sk_drops);
583 			err = NET_RX_DROP;
584 			break;
585 		}
586 		pn->rx_credits--;
587 		skb->dev = NULL;
588 		skb_set_owner_r(skb, sk);
589 		skb_queue_tail(&sk->sk_receive_queue, skb);
590 		if (!sock_flag(sk, SOCK_DEAD))
591 			sk->sk_data_ready(sk);
592 		return NET_RX_SUCCESS;
593 
594 	case PNS_PEP_CONNECT_RESP:
595 		if (sk->sk_state != TCP_SYN_SENT)
596 			break;
597 		if (!sock_flag(sk, SOCK_DEAD))
598 			sk->sk_state_change(sk);
599 		if (pep_connresp_rcv(sk, skb)) {
600 			sk->sk_state = TCP_CLOSE_WAIT;
601 			break;
602 		}
603 		if (pn->init_enable == PN_PIPE_DISABLE)
604 			sk->sk_state = TCP_SYN_RECV;
605 		else {
606 			sk->sk_state = TCP_ESTABLISHED;
607 			pipe_start_flow_control(sk);
608 		}
609 		break;
610 
611 	case PNS_PEP_ENABLE_RESP:
612 		if (sk->sk_state != TCP_SYN_SENT)
613 			break;
614 
615 		if (pep_enableresp_rcv(sk, skb)) {
616 			sk->sk_state = TCP_CLOSE_WAIT;
617 			break;
618 		}
619 
620 		sk->sk_state = TCP_ESTABLISHED;
621 		pipe_start_flow_control(sk);
622 		break;
623 
624 	case PNS_PEP_DISCONNECT_RESP:
625 		/* sock should already be dead, nothing to do */
626 		break;
627 
628 	case PNS_PEP_STATUS_IND:
629 		pipe_rcv_status(sk, skb);
630 		break;
631 	}
632 	kfree_skb(skb);
633 	return err;
634 }
635 
636 /* Listening sock must be locked */
637 static struct sock *pep_find_pipe(const struct hlist_head *hlist,
638 					const struct sockaddr_pn *dst,
639 					u8 pipe_handle)
640 {
641 	struct sock *sknode;
642 	u16 dobj = pn_sockaddr_get_object(dst);
643 
644 	sk_for_each(sknode, hlist) {
645 		struct pep_sock *pnnode = pep_sk(sknode);
646 
647 		/* Ports match, but addresses might not: */
648 		if (pnnode->pn_sk.sobject != dobj)
649 			continue;
650 		if (pnnode->pipe_handle != pipe_handle)
651 			continue;
652 		if (sknode->sk_state == TCP_CLOSE_WAIT)
653 			continue;
654 
655 		sock_hold(sknode);
656 		return sknode;
657 	}
658 	return NULL;
659 }
660 
661 /*
662  * Deliver an skb to a listening sock.
663  * Socket lock must be held.
664  * We then queue the skb to the right connected sock (if any).
665  */
666 static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
667 {
668 	struct pep_sock *pn = pep_sk(sk);
669 	struct sock *sknode;
670 	struct pnpipehdr *hdr;
671 	struct sockaddr_pn dst;
672 	u8 pipe_handle;
673 
674 	if (!pskb_may_pull(skb, sizeof(*hdr)))
675 		goto drop;
676 
677 	hdr = pnp_hdr(skb);
678 	pipe_handle = hdr->pipe_handle;
679 	if (pipe_handle == PN_PIPE_INVALID_HANDLE)
680 		goto drop;
681 
682 	pn_skb_get_dst_sockaddr(skb, &dst);
683 
684 	/* Look for an existing pipe handle */
685 	sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
686 	if (sknode)
687 		return sk_receive_skb(sknode, skb, 1);
688 
689 	switch (hdr->message_id) {
690 	case PNS_PEP_CONNECT_REQ:
691 		if (sk->sk_state != TCP_LISTEN || sk_acceptq_is_full(sk)) {
692 			pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE,
693 					GFP_ATOMIC);
694 			break;
695 		}
696 		skb_queue_head(&sk->sk_receive_queue, skb);
697 		sk_acceptq_added(sk);
698 		if (!sock_flag(sk, SOCK_DEAD))
699 			sk->sk_data_ready(sk);
700 		return NET_RX_SUCCESS;
701 
702 	case PNS_PEP_DISCONNECT_REQ:
703 		pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
704 		break;
705 
706 	case PNS_PEP_CTRL_REQ:
707 		pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
708 		break;
709 
710 	case PNS_PEP_RESET_REQ:
711 	case PNS_PEP_ENABLE_REQ:
712 	case PNS_PEP_DISABLE_REQ:
713 		/* invalid handle is not even allowed here! */
714 		break;
715 
716 	default:
717 		if ((1 << sk->sk_state)
718 				& ~(TCPF_CLOSE|TCPF_LISTEN|TCPF_CLOSE_WAIT))
719 			/* actively connected socket */
720 			return pipe_handler_do_rcv(sk, skb);
721 	}
722 drop:
723 	kfree_skb(skb);
724 	return NET_RX_SUCCESS;
725 }
726 
727 static int pipe_do_remove(struct sock *sk)
728 {
729 	struct pep_sock *pn = pep_sk(sk);
730 	struct pnpipehdr *ph;
731 	struct sk_buff *skb;
732 
733 	skb = pep_alloc_skb(sk, NULL, 0, GFP_KERNEL);
734 	if (!skb)
735 		return -ENOMEM;
736 
737 	ph = pnp_hdr(skb);
738 	ph->utid = 0;
739 	ph->message_id = PNS_PIPE_REMOVE_REQ;
740 	ph->pipe_handle = pn->pipe_handle;
741 	ph->data[0] = PAD;
742 	return pn_skb_send(sk, skb, NULL);
743 }
744 
745 /* associated socket ceases to exist */
746 static void pep_sock_close(struct sock *sk, long timeout)
747 {
748 	struct pep_sock *pn = pep_sk(sk);
749 	int ifindex = 0;
750 
751 	sock_hold(sk); /* keep a reference after sk_common_release() */
752 	sk_common_release(sk);
753 
754 	lock_sock(sk);
755 	if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED)) {
756 		if (sk->sk_backlog_rcv == pipe_do_rcv)
757 			/* Forcefully remove dangling Phonet pipe */
758 			pipe_do_remove(sk);
759 		else
760 			pipe_handler_request(sk, PNS_PEP_DISCONNECT_REQ, PAD,
761 						NULL, 0);
762 	}
763 	sk->sk_state = TCP_CLOSE;
764 
765 	ifindex = pn->ifindex;
766 	pn->ifindex = 0;
767 	release_sock(sk);
768 
769 	if (ifindex)
770 		gprs_detach(sk);
771 	sock_put(sk);
772 }
773 
774 static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
775 {
776 	struct pep_sock *pn = pep_sk(sk), *newpn;
777 	struct sock *newsk = NULL;
778 	struct sk_buff *skb;
779 	struct pnpipehdr *hdr;
780 	struct sockaddr_pn dst, src;
781 	int err;
782 	u16 peer_type;
783 	u8 pipe_handle, enabled, n_sb;
784 	u8 aligned = 0;
785 
786 	skb = skb_recv_datagram(sk, 0, flags & O_NONBLOCK, errp);
787 	if (!skb)
788 		return NULL;
789 
790 	lock_sock(sk);
791 	if (sk->sk_state != TCP_LISTEN) {
792 		err = -EINVAL;
793 		goto drop;
794 	}
795 	sk_acceptq_removed(sk);
796 
797 	err = -EPROTO;
798 	if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
799 		goto drop;
800 
801 	hdr = pnp_hdr(skb);
802 	pipe_handle = hdr->pipe_handle;
803 	switch (hdr->state_after_connect) {
804 	case PN_PIPE_DISABLE:
805 		enabled = 0;
806 		break;
807 	case PN_PIPE_ENABLE:
808 		enabled = 1;
809 		break;
810 	default:
811 		pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM,
812 				GFP_KERNEL);
813 		goto drop;
814 	}
815 	peer_type = hdr->other_pep_type << 8;
816 
817 	/* Parse sub-blocks (options) */
818 	n_sb = hdr->data[4];
819 	while (n_sb > 0) {
820 		u8 type, buf[1], len = sizeof(buf);
821 		const u8 *data = pep_get_sb(skb, &type, &len, buf);
822 
823 		if (data == NULL)
824 			goto drop;
825 		switch (type) {
826 		case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
827 			if (len < 1)
828 				goto drop;
829 			peer_type = (peer_type & 0xff00) | data[0];
830 			break;
831 		case PN_PIPE_SB_ALIGNED_DATA:
832 			aligned = data[0] != 0;
833 			break;
834 		}
835 		n_sb--;
836 	}
837 
838 	/* Check for duplicate pipe handle */
839 	newsk = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
840 	if (unlikely(newsk)) {
841 		__sock_put(newsk);
842 		newsk = NULL;
843 		pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, GFP_KERNEL);
844 		goto drop;
845 	}
846 
847 	/* Create a new to-be-accepted sock */
848 	newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_KERNEL, sk->sk_prot);
849 	if (!newsk) {
850 		pep_reject_conn(sk, skb, PN_PIPE_ERR_OVERLOAD, GFP_KERNEL);
851 		err = -ENOBUFS;
852 		goto drop;
853 	}
854 
855 	sock_init_data(NULL, newsk);
856 	newsk->sk_state = TCP_SYN_RECV;
857 	newsk->sk_backlog_rcv = pipe_do_rcv;
858 	newsk->sk_protocol = sk->sk_protocol;
859 	newsk->sk_destruct = pipe_destruct;
860 
861 	newpn = pep_sk(newsk);
862 	pn_skb_get_dst_sockaddr(skb, &dst);
863 	pn_skb_get_src_sockaddr(skb, &src);
864 	newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
865 	newpn->pn_sk.dobject = pn_sockaddr_get_object(&src);
866 	newpn->pn_sk.resource = pn_sockaddr_get_resource(&dst);
867 	sock_hold(sk);
868 	newpn->listener = sk;
869 	skb_queue_head_init(&newpn->ctrlreq_queue);
870 	newpn->pipe_handle = pipe_handle;
871 	atomic_set(&newpn->tx_credits, 0);
872 	newpn->ifindex = 0;
873 	newpn->peer_type = peer_type;
874 	newpn->rx_credits = 0;
875 	newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
876 	newpn->init_enable = enabled;
877 	newpn->aligned = aligned;
878 
879 	err = pep_accept_conn(newsk, skb);
880 	if (err) {
881 		sock_put(newsk);
882 		newsk = NULL;
883 		goto drop;
884 	}
885 	sk_add_node(newsk, &pn->hlist);
886 drop:
887 	release_sock(sk);
888 	kfree_skb(skb);
889 	*errp = err;
890 	return newsk;
891 }
892 
893 static int pep_sock_connect(struct sock *sk, struct sockaddr *addr, int len)
894 {
895 	struct pep_sock *pn = pep_sk(sk);
896 	int err;
897 	u8 data[4] = { 0 /* sub-blocks */, PAD, PAD, PAD };
898 
899 	if (pn->pipe_handle == PN_PIPE_INVALID_HANDLE)
900 		pn->pipe_handle = 1; /* anything but INVALID_HANDLE */
901 
902 	err = pipe_handler_request(sk, PNS_PEP_CONNECT_REQ,
903 				pn->init_enable, data, 4);
904 	if (err) {
905 		pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
906 		return err;
907 	}
908 
909 	sk->sk_state = TCP_SYN_SENT;
910 
911 	return 0;
912 }
913 
914 static int pep_sock_enable(struct sock *sk, struct sockaddr *addr, int len)
915 {
916 	int err;
917 
918 	err = pipe_handler_request(sk, PNS_PEP_ENABLE_REQ, PAD,
919 				NULL, 0);
920 	if (err)
921 		return err;
922 
923 	sk->sk_state = TCP_SYN_SENT;
924 
925 	return 0;
926 }
927 
928 static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
929 {
930 	struct pep_sock *pn = pep_sk(sk);
931 	int answ;
932 	int ret = -ENOIOCTLCMD;
933 
934 	switch (cmd) {
935 	case SIOCINQ:
936 		if (sk->sk_state == TCP_LISTEN) {
937 			ret = -EINVAL;
938 			break;
939 		}
940 
941 		lock_sock(sk);
942 		if (sock_flag(sk, SOCK_URGINLINE) &&
943 		    !skb_queue_empty(&pn->ctrlreq_queue))
944 			answ = skb_peek(&pn->ctrlreq_queue)->len;
945 		else if (!skb_queue_empty(&sk->sk_receive_queue))
946 			answ = skb_peek(&sk->sk_receive_queue)->len;
947 		else
948 			answ = 0;
949 		release_sock(sk);
950 		ret = put_user(answ, (int __user *)arg);
951 		break;
952 
953 	case SIOCPNENABLEPIPE:
954 		lock_sock(sk);
955 		if (sk->sk_state == TCP_SYN_SENT)
956 			ret =  -EBUSY;
957 		else if (sk->sk_state == TCP_ESTABLISHED)
958 			ret = -EISCONN;
959 		else
960 			ret = pep_sock_enable(sk, NULL, 0);
961 		release_sock(sk);
962 		break;
963 	}
964 
965 	return ret;
966 }
967 
968 static int pep_init(struct sock *sk)
969 {
970 	struct pep_sock *pn = pep_sk(sk);
971 
972 	sk->sk_destruct = pipe_destruct;
973 	INIT_HLIST_HEAD(&pn->hlist);
974 	pn->listener = NULL;
975 	skb_queue_head_init(&pn->ctrlreq_queue);
976 	atomic_set(&pn->tx_credits, 0);
977 	pn->ifindex = 0;
978 	pn->peer_type = 0;
979 	pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
980 	pn->rx_credits = 0;
981 	pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
982 	pn->init_enable = 1;
983 	pn->aligned = 0;
984 	return 0;
985 }
986 
987 static int pep_setsockopt(struct sock *sk, int level, int optname,
988 				char __user *optval, unsigned int optlen)
989 {
990 	struct pep_sock *pn = pep_sk(sk);
991 	int val = 0, err = 0;
992 
993 	if (level != SOL_PNPIPE)
994 		return -ENOPROTOOPT;
995 	if (optlen >= sizeof(int)) {
996 		if (get_user(val, (int __user *) optval))
997 			return -EFAULT;
998 	}
999 
1000 	lock_sock(sk);
1001 	switch (optname) {
1002 	case PNPIPE_ENCAP:
1003 		if (val && val != PNPIPE_ENCAP_IP) {
1004 			err = -EINVAL;
1005 			break;
1006 		}
1007 		if (!pn->ifindex == !val)
1008 			break; /* Nothing to do! */
1009 		if (!capable(CAP_NET_ADMIN)) {
1010 			err = -EPERM;
1011 			break;
1012 		}
1013 		if (val) {
1014 			release_sock(sk);
1015 			err = gprs_attach(sk);
1016 			if (err > 0) {
1017 				pn->ifindex = err;
1018 				err = 0;
1019 			}
1020 		} else {
1021 			pn->ifindex = 0;
1022 			release_sock(sk);
1023 			gprs_detach(sk);
1024 			err = 0;
1025 		}
1026 		goto out_norel;
1027 
1028 	case PNPIPE_HANDLE:
1029 		if ((sk->sk_state == TCP_CLOSE) &&
1030 			(val >= 0) && (val < PN_PIPE_INVALID_HANDLE))
1031 			pn->pipe_handle = val;
1032 		else
1033 			err = -EINVAL;
1034 		break;
1035 
1036 	case PNPIPE_INITSTATE:
1037 		pn->init_enable = !!val;
1038 		break;
1039 
1040 	default:
1041 		err = -ENOPROTOOPT;
1042 	}
1043 	release_sock(sk);
1044 
1045 out_norel:
1046 	return err;
1047 }
1048 
1049 static int pep_getsockopt(struct sock *sk, int level, int optname,
1050 				char __user *optval, int __user *optlen)
1051 {
1052 	struct pep_sock *pn = pep_sk(sk);
1053 	int len, val;
1054 
1055 	if (level != SOL_PNPIPE)
1056 		return -ENOPROTOOPT;
1057 	if (get_user(len, optlen))
1058 		return -EFAULT;
1059 
1060 	switch (optname) {
1061 	case PNPIPE_ENCAP:
1062 		val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
1063 		break;
1064 
1065 	case PNPIPE_IFINDEX:
1066 		val = pn->ifindex;
1067 		break;
1068 
1069 	case PNPIPE_HANDLE:
1070 		val = pn->pipe_handle;
1071 		if (val == PN_PIPE_INVALID_HANDLE)
1072 			return -EINVAL;
1073 		break;
1074 
1075 	case PNPIPE_INITSTATE:
1076 		val = pn->init_enable;
1077 		break;
1078 
1079 	default:
1080 		return -ENOPROTOOPT;
1081 	}
1082 
1083 	len = min_t(unsigned int, sizeof(int), len);
1084 	if (put_user(len, optlen))
1085 		return -EFAULT;
1086 	if (put_user(val, (int __user *) optval))
1087 		return -EFAULT;
1088 	return 0;
1089 }
1090 
1091 static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
1092 {
1093 	struct pep_sock *pn = pep_sk(sk);
1094 	struct pnpipehdr *ph;
1095 	int err;
1096 
1097 	if (pn_flow_safe(pn->tx_fc) &&
1098 	    !atomic_add_unless(&pn->tx_credits, -1, 0)) {
1099 		kfree_skb(skb);
1100 		return -ENOBUFS;
1101 	}
1102 
1103 	skb_push(skb, 3 + pn->aligned);
1104 	skb_reset_transport_header(skb);
1105 	ph = pnp_hdr(skb);
1106 	ph->utid = 0;
1107 	if (pn->aligned) {
1108 		ph->message_id = PNS_PIPE_ALIGNED_DATA;
1109 		ph->data[0] = 0; /* padding */
1110 	} else
1111 		ph->message_id = PNS_PIPE_DATA;
1112 	ph->pipe_handle = pn->pipe_handle;
1113 	err = pn_skb_send(sk, skb, NULL);
1114 
1115 	if (err && pn_flow_safe(pn->tx_fc))
1116 		atomic_inc(&pn->tx_credits);
1117 	return err;
1118 
1119 }
1120 
1121 static int pep_sendmsg(struct kiocb *iocb, struct sock *sk,
1122 			struct msghdr *msg, size_t len)
1123 {
1124 	struct pep_sock *pn = pep_sk(sk);
1125 	struct sk_buff *skb;
1126 	long timeo;
1127 	int flags = msg->msg_flags;
1128 	int err, done;
1129 
1130 	if (len > USHRT_MAX)
1131 		return -EMSGSIZE;
1132 
1133 	if ((msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|
1134 				MSG_CMSG_COMPAT)) ||
1135 			!(msg->msg_flags & MSG_EOR))
1136 		return -EOPNOTSUPP;
1137 
1138 	skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
1139 					flags & MSG_DONTWAIT, &err);
1140 	if (!skb)
1141 		return err;
1142 
1143 	skb_reserve(skb, MAX_PHONET_HEADER + 3 + pn->aligned);
1144 	err = memcpy_from_msg(skb_put(skb, len), msg, len);
1145 	if (err < 0)
1146 		goto outfree;
1147 
1148 	lock_sock(sk);
1149 	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
1150 	if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
1151 		err = -ENOTCONN;
1152 		goto out;
1153 	}
1154 	if (sk->sk_state != TCP_ESTABLISHED) {
1155 		/* Wait until the pipe gets to enabled state */
1156 disabled:
1157 		err = sk_stream_wait_connect(sk, &timeo);
1158 		if (err)
1159 			goto out;
1160 
1161 		if (sk->sk_state == TCP_CLOSE_WAIT) {
1162 			err = -ECONNRESET;
1163 			goto out;
1164 		}
1165 	}
1166 	BUG_ON(sk->sk_state != TCP_ESTABLISHED);
1167 
1168 	/* Wait until flow control allows TX */
1169 	done = atomic_read(&pn->tx_credits);
1170 	while (!done) {
1171 		DEFINE_WAIT(wait);
1172 
1173 		if (!timeo) {
1174 			err = -EAGAIN;
1175 			goto out;
1176 		}
1177 		if (signal_pending(current)) {
1178 			err = sock_intr_errno(timeo);
1179 			goto out;
1180 		}
1181 
1182 		prepare_to_wait(sk_sleep(sk), &wait,
1183 				TASK_INTERRUPTIBLE);
1184 		done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits));
1185 		finish_wait(sk_sleep(sk), &wait);
1186 
1187 		if (sk->sk_state != TCP_ESTABLISHED)
1188 			goto disabled;
1189 	}
1190 
1191 	err = pipe_skb_send(sk, skb);
1192 	if (err >= 0)
1193 		err = len; /* success! */
1194 	skb = NULL;
1195 out:
1196 	release_sock(sk);
1197 outfree:
1198 	kfree_skb(skb);
1199 	return err;
1200 }
1201 
1202 int pep_writeable(struct sock *sk)
1203 {
1204 	struct pep_sock *pn = pep_sk(sk);
1205 
1206 	return atomic_read(&pn->tx_credits);
1207 }
1208 
1209 int pep_write(struct sock *sk, struct sk_buff *skb)
1210 {
1211 	struct sk_buff *rskb, *fs;
1212 	int flen = 0;
1213 
1214 	if (pep_sk(sk)->aligned)
1215 		return pipe_skb_send(sk, skb);
1216 
1217 	rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
1218 	if (!rskb) {
1219 		kfree_skb(skb);
1220 		return -ENOMEM;
1221 	}
1222 	skb_shinfo(rskb)->frag_list = skb;
1223 	rskb->len += skb->len;
1224 	rskb->data_len += rskb->len;
1225 	rskb->truesize += rskb->len;
1226 
1227 	/* Avoid nested fragments */
1228 	skb_walk_frags(skb, fs)
1229 		flen += fs->len;
1230 	skb->next = skb_shinfo(skb)->frag_list;
1231 	skb_frag_list_init(skb);
1232 	skb->len -= flen;
1233 	skb->data_len -= flen;
1234 	skb->truesize -= flen;
1235 
1236 	skb_reserve(rskb, MAX_PHONET_HEADER + 3);
1237 	return pipe_skb_send(sk, rskb);
1238 }
1239 
1240 struct sk_buff *pep_read(struct sock *sk)
1241 {
1242 	struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
1243 
1244 	if (sk->sk_state == TCP_ESTABLISHED)
1245 		pipe_grant_credits(sk, GFP_ATOMIC);
1246 	return skb;
1247 }
1248 
1249 static int pep_recvmsg(struct kiocb *iocb, struct sock *sk,
1250 			struct msghdr *msg, size_t len, int noblock,
1251 			int flags, int *addr_len)
1252 {
1253 	struct sk_buff *skb;
1254 	int err;
1255 
1256 	if (flags & ~(MSG_OOB|MSG_PEEK|MSG_TRUNC|MSG_DONTWAIT|MSG_WAITALL|
1257 			MSG_NOSIGNAL|MSG_CMSG_COMPAT))
1258 		return -EOPNOTSUPP;
1259 
1260 	if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
1261 		return -ENOTCONN;
1262 
1263 	if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
1264 		/* Dequeue and acknowledge control request */
1265 		struct pep_sock *pn = pep_sk(sk);
1266 
1267 		if (flags & MSG_PEEK)
1268 			return -EOPNOTSUPP;
1269 		skb = skb_dequeue(&pn->ctrlreq_queue);
1270 		if (skb) {
1271 			pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
1272 						GFP_KERNEL);
1273 			msg->msg_flags |= MSG_OOB;
1274 			goto copy;
1275 		}
1276 		if (flags & MSG_OOB)
1277 			return -EINVAL;
1278 	}
1279 
1280 	skb = skb_recv_datagram(sk, flags, noblock, &err);
1281 	lock_sock(sk);
1282 	if (skb == NULL) {
1283 		if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
1284 			err = -ECONNRESET;
1285 		release_sock(sk);
1286 		return err;
1287 	}
1288 
1289 	if (sk->sk_state == TCP_ESTABLISHED)
1290 		pipe_grant_credits(sk, GFP_KERNEL);
1291 	release_sock(sk);
1292 copy:
1293 	msg->msg_flags |= MSG_EOR;
1294 	if (skb->len > len)
1295 		msg->msg_flags |= MSG_TRUNC;
1296 	else
1297 		len = skb->len;
1298 
1299 	err = skb_copy_datagram_msg(skb, 0, msg, len);
1300 	if (!err)
1301 		err = (flags & MSG_TRUNC) ? skb->len : len;
1302 
1303 	skb_free_datagram(sk, skb);
1304 	return err;
1305 }
1306 
1307 static void pep_sock_unhash(struct sock *sk)
1308 {
1309 	struct pep_sock *pn = pep_sk(sk);
1310 	struct sock *skparent = NULL;
1311 
1312 	lock_sock(sk);
1313 
1314 	if (pn->listener != NULL) {
1315 		skparent = pn->listener;
1316 		pn->listener = NULL;
1317 		release_sock(sk);
1318 
1319 		pn = pep_sk(skparent);
1320 		lock_sock(skparent);
1321 		sk_del_node_init(sk);
1322 		sk = skparent;
1323 	}
1324 
1325 	/* Unhash a listening sock only when it is closed
1326 	 * and all of its active connected pipes are closed. */
1327 	if (hlist_empty(&pn->hlist))
1328 		pn_sock_unhash(&pn->pn_sk.sk);
1329 	release_sock(sk);
1330 
1331 	if (skparent)
1332 		sock_put(skparent);
1333 }
1334 
1335 static struct proto pep_proto = {
1336 	.close		= pep_sock_close,
1337 	.accept		= pep_sock_accept,
1338 	.connect	= pep_sock_connect,
1339 	.ioctl		= pep_ioctl,
1340 	.init		= pep_init,
1341 	.setsockopt	= pep_setsockopt,
1342 	.getsockopt	= pep_getsockopt,
1343 	.sendmsg	= pep_sendmsg,
1344 	.recvmsg	= pep_recvmsg,
1345 	.backlog_rcv	= pep_do_rcv,
1346 	.hash		= pn_sock_hash,
1347 	.unhash		= pep_sock_unhash,
1348 	.get_port	= pn_sock_get_port,
1349 	.obj_size	= sizeof(struct pep_sock),
1350 	.owner		= THIS_MODULE,
1351 	.name		= "PNPIPE",
1352 };
1353 
1354 static struct phonet_protocol pep_pn_proto = {
1355 	.ops		= &phonet_stream_ops,
1356 	.prot		= &pep_proto,
1357 	.sock_type	= SOCK_SEQPACKET,
1358 };
1359 
1360 static int __init pep_register(void)
1361 {
1362 	return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
1363 }
1364 
1365 static void __exit pep_unregister(void)
1366 {
1367 	phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
1368 }
1369 
1370 module_init(pep_register);
1371 module_exit(pep_unregister);
1372 MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
1373 MODULE_DESCRIPTION("Phonet pipe protocol");
1374 MODULE_LICENSE("GPL");
1375 MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);
1376