xref: /openbmc/linux/net/phonet/socket.c (revision 4f3db074)
1 /*
2  * File: socket.c
3  *
4  * Phonet sockets
5  *
6  * Copyright (C) 2008 Nokia Corporation.
7  *
8  * Authors: Sakari Ailus <sakari.ailus@nokia.com>
9  *          Rémi Denis-Courmont
10  *
11  * This program is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU General Public License
13  * version 2 as published by the Free Software Foundation.
14  *
15  * This program is distributed in the hope that it will be useful, but
16  * WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  * General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
23  * 02110-1301 USA
24  */
25 
26 #include <linux/gfp.h>
27 #include <linux/kernel.h>
28 #include <linux/net.h>
29 #include <linux/poll.h>
30 #include <net/sock.h>
31 #include <net/tcp_states.h>
32 
33 #include <linux/phonet.h>
34 #include <linux/export.h>
35 #include <net/phonet/phonet.h>
36 #include <net/phonet/pep.h>
37 #include <net/phonet/pn_dev.h>
38 
39 static int pn_socket_release(struct socket *sock)
40 {
41 	struct sock *sk = sock->sk;
42 
43 	if (sk) {
44 		sock->sk = NULL;
45 		sk->sk_prot->close(sk, 0);
46 	}
47 	return 0;
48 }
49 
50 #define PN_HASHSIZE	16
51 #define PN_HASHMASK	(PN_HASHSIZE-1)
52 
53 
54 static struct  {
55 	struct hlist_head hlist[PN_HASHSIZE];
56 	struct mutex lock;
57 } pnsocks;
58 
59 void __init pn_sock_init(void)
60 {
61 	unsigned int i;
62 
63 	for (i = 0; i < PN_HASHSIZE; i++)
64 		INIT_HLIST_HEAD(pnsocks.hlist + i);
65 	mutex_init(&pnsocks.lock);
66 }
67 
68 static struct hlist_head *pn_hash_list(u16 obj)
69 {
70 	return pnsocks.hlist + (obj & PN_HASHMASK);
71 }
72 
73 /*
74  * Find address based on socket address, match only certain fields.
75  * Also grab sock if it was found. Remember to sock_put it later.
76  */
77 struct sock *pn_find_sock_by_sa(struct net *net, const struct sockaddr_pn *spn)
78 {
79 	struct sock *sknode;
80 	struct sock *rval = NULL;
81 	u16 obj = pn_sockaddr_get_object(spn);
82 	u8 res = spn->spn_resource;
83 	struct hlist_head *hlist = pn_hash_list(obj);
84 
85 	rcu_read_lock();
86 	sk_for_each_rcu(sknode, hlist) {
87 		struct pn_sock *pn = pn_sk(sknode);
88 		BUG_ON(!pn->sobject); /* unbound socket */
89 
90 		if (!net_eq(sock_net(sknode), net))
91 			continue;
92 		if (pn_port(obj)) {
93 			/* Look up socket by port */
94 			if (pn_port(pn->sobject) != pn_port(obj))
95 				continue;
96 		} else {
97 			/* If port is zero, look up by resource */
98 			if (pn->resource != res)
99 				continue;
100 		}
101 		if (pn_addr(pn->sobject) &&
102 		    pn_addr(pn->sobject) != pn_addr(obj))
103 			continue;
104 
105 		rval = sknode;
106 		sock_hold(sknode);
107 		break;
108 	}
109 	rcu_read_unlock();
110 
111 	return rval;
112 }
113 
114 /* Deliver a broadcast packet (only in bottom-half) */
115 void pn_deliver_sock_broadcast(struct net *net, struct sk_buff *skb)
116 {
117 	struct hlist_head *hlist = pnsocks.hlist;
118 	unsigned int h;
119 
120 	rcu_read_lock();
121 	for (h = 0; h < PN_HASHSIZE; h++) {
122 		struct sock *sknode;
123 
124 		sk_for_each(sknode, hlist) {
125 			struct sk_buff *clone;
126 
127 			if (!net_eq(sock_net(sknode), net))
128 				continue;
129 			if (!sock_flag(sknode, SOCK_BROADCAST))
130 				continue;
131 
132 			clone = skb_clone(skb, GFP_ATOMIC);
133 			if (clone) {
134 				sock_hold(sknode);
135 				sk_receive_skb(sknode, clone, 0);
136 			}
137 		}
138 		hlist++;
139 	}
140 	rcu_read_unlock();
141 }
142 
143 void pn_sock_hash(struct sock *sk)
144 {
145 	struct hlist_head *hlist = pn_hash_list(pn_sk(sk)->sobject);
146 
147 	mutex_lock(&pnsocks.lock);
148 	sk_add_node_rcu(sk, hlist);
149 	mutex_unlock(&pnsocks.lock);
150 }
151 EXPORT_SYMBOL(pn_sock_hash);
152 
153 void pn_sock_unhash(struct sock *sk)
154 {
155 	mutex_lock(&pnsocks.lock);
156 	sk_del_node_init_rcu(sk);
157 	mutex_unlock(&pnsocks.lock);
158 	pn_sock_unbind_all_res(sk);
159 	synchronize_rcu();
160 }
161 EXPORT_SYMBOL(pn_sock_unhash);
162 
163 static DEFINE_MUTEX(port_mutex);
164 
165 static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
166 {
167 	struct sock *sk = sock->sk;
168 	struct pn_sock *pn = pn_sk(sk);
169 	struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
170 	int err;
171 	u16 handle;
172 	u8 saddr;
173 
174 	if (sk->sk_prot->bind)
175 		return sk->sk_prot->bind(sk, addr, len);
176 
177 	if (len < sizeof(struct sockaddr_pn))
178 		return -EINVAL;
179 	if (spn->spn_family != AF_PHONET)
180 		return -EAFNOSUPPORT;
181 
182 	handle = pn_sockaddr_get_object((struct sockaddr_pn *)addr);
183 	saddr = pn_addr(handle);
184 	if (saddr && phonet_address_lookup(sock_net(sk), saddr))
185 		return -EADDRNOTAVAIL;
186 
187 	lock_sock(sk);
188 	if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
189 		err = -EINVAL; /* attempt to rebind */
190 		goto out;
191 	}
192 	WARN_ON(sk_hashed(sk));
193 	mutex_lock(&port_mutex);
194 	err = sk->sk_prot->get_port(sk, pn_port(handle));
195 	if (err)
196 		goto out_port;
197 
198 	/* get_port() sets the port, bind() sets the address if applicable */
199 	pn->sobject = pn_object(saddr, pn_port(pn->sobject));
200 	pn->resource = spn->spn_resource;
201 
202 	/* Enable RX on the socket */
203 	sk->sk_prot->hash(sk);
204 out_port:
205 	mutex_unlock(&port_mutex);
206 out:
207 	release_sock(sk);
208 	return err;
209 }
210 
211 static int pn_socket_autobind(struct socket *sock)
212 {
213 	struct sockaddr_pn sa;
214 	int err;
215 
216 	memset(&sa, 0, sizeof(sa));
217 	sa.spn_family = AF_PHONET;
218 	err = pn_socket_bind(sock, (struct sockaddr *)&sa,
219 				sizeof(struct sockaddr_pn));
220 	if (err != -EINVAL)
221 		return err;
222 	BUG_ON(!pn_port(pn_sk(sock->sk)->sobject));
223 	return 0; /* socket was already bound */
224 }
225 
226 static int pn_socket_connect(struct socket *sock, struct sockaddr *addr,
227 		int len, int flags)
228 {
229 	struct sock *sk = sock->sk;
230 	struct pn_sock *pn = pn_sk(sk);
231 	struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
232 	struct task_struct *tsk = current;
233 	long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
234 	int err;
235 
236 	if (pn_socket_autobind(sock))
237 		return -ENOBUFS;
238 	if (len < sizeof(struct sockaddr_pn))
239 		return -EINVAL;
240 	if (spn->spn_family != AF_PHONET)
241 		return -EAFNOSUPPORT;
242 
243 	lock_sock(sk);
244 
245 	switch (sock->state) {
246 	case SS_UNCONNECTED:
247 		if (sk->sk_state != TCP_CLOSE) {
248 			err = -EISCONN;
249 			goto out;
250 		}
251 		break;
252 	case SS_CONNECTING:
253 		err = -EALREADY;
254 		goto out;
255 	default:
256 		err = -EISCONN;
257 		goto out;
258 	}
259 
260 	pn->dobject = pn_sockaddr_get_object(spn);
261 	pn->resource = pn_sockaddr_get_resource(spn);
262 	sock->state = SS_CONNECTING;
263 
264 	err = sk->sk_prot->connect(sk, addr, len);
265 	if (err) {
266 		sock->state = SS_UNCONNECTED;
267 		pn->dobject = 0;
268 		goto out;
269 	}
270 
271 	while (sk->sk_state == TCP_SYN_SENT) {
272 		DEFINE_WAIT(wait);
273 
274 		if (!timeo) {
275 			err = -EINPROGRESS;
276 			goto out;
277 		}
278 		if (signal_pending(tsk)) {
279 			err = sock_intr_errno(timeo);
280 			goto out;
281 		}
282 
283 		prepare_to_wait_exclusive(sk_sleep(sk), &wait,
284 						TASK_INTERRUPTIBLE);
285 		release_sock(sk);
286 		timeo = schedule_timeout(timeo);
287 		lock_sock(sk);
288 		finish_wait(sk_sleep(sk), &wait);
289 	}
290 
291 	if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED))
292 		err = 0;
293 	else if (sk->sk_state == TCP_CLOSE_WAIT)
294 		err = -ECONNRESET;
295 	else
296 		err = -ECONNREFUSED;
297 	sock->state = err ? SS_UNCONNECTED : SS_CONNECTED;
298 out:
299 	release_sock(sk);
300 	return err;
301 }
302 
303 static int pn_socket_accept(struct socket *sock, struct socket *newsock,
304 				int flags)
305 {
306 	struct sock *sk = sock->sk;
307 	struct sock *newsk;
308 	int err;
309 
310 	if (unlikely(sk->sk_state != TCP_LISTEN))
311 		return -EINVAL;
312 
313 	newsk = sk->sk_prot->accept(sk, flags, &err);
314 	if (!newsk)
315 		return err;
316 
317 	lock_sock(newsk);
318 	sock_graft(newsk, newsock);
319 	newsock->state = SS_CONNECTED;
320 	release_sock(newsk);
321 	return 0;
322 }
323 
324 static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
325 				int *sockaddr_len, int peer)
326 {
327 	struct sock *sk = sock->sk;
328 	struct pn_sock *pn = pn_sk(sk);
329 
330 	memset(addr, 0, sizeof(struct sockaddr_pn));
331 	addr->sa_family = AF_PHONET;
332 	if (!peer) /* Race with bind() here is userland's problem. */
333 		pn_sockaddr_set_object((struct sockaddr_pn *)addr,
334 					pn->sobject);
335 
336 	*sockaddr_len = sizeof(struct sockaddr_pn);
337 	return 0;
338 }
339 
340 static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
341 					poll_table *wait)
342 {
343 	struct sock *sk = sock->sk;
344 	struct pep_sock *pn = pep_sk(sk);
345 	unsigned int mask = 0;
346 
347 	poll_wait(file, sk_sleep(sk), wait);
348 
349 	if (sk->sk_state == TCP_CLOSE)
350 		return POLLERR;
351 	if (!skb_queue_empty(&sk->sk_receive_queue))
352 		mask |= POLLIN | POLLRDNORM;
353 	if (!skb_queue_empty(&pn->ctrlreq_queue))
354 		mask |= POLLPRI;
355 	if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
356 		return POLLHUP;
357 
358 	if (sk->sk_state == TCP_ESTABLISHED &&
359 		atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf &&
360 		atomic_read(&pn->tx_credits))
361 		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
362 
363 	return mask;
364 }
365 
366 static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
367 				unsigned long arg)
368 {
369 	struct sock *sk = sock->sk;
370 	struct pn_sock *pn = pn_sk(sk);
371 
372 	if (cmd == SIOCPNGETOBJECT) {
373 		struct net_device *dev;
374 		u16 handle;
375 		u8 saddr;
376 
377 		if (get_user(handle, (__u16 __user *)arg))
378 			return -EFAULT;
379 
380 		lock_sock(sk);
381 		if (sk->sk_bound_dev_if)
382 			dev = dev_get_by_index(sock_net(sk),
383 						sk->sk_bound_dev_if);
384 		else
385 			dev = phonet_device_get(sock_net(sk));
386 		if (dev && (dev->flags & IFF_UP))
387 			saddr = phonet_address_get(dev, pn_addr(handle));
388 		else
389 			saddr = PN_NO_ADDR;
390 		release_sock(sk);
391 
392 		if (dev)
393 			dev_put(dev);
394 		if (saddr == PN_NO_ADDR)
395 			return -EHOSTUNREACH;
396 
397 		handle = pn_object(saddr, pn_port(pn->sobject));
398 		return put_user(handle, (__u16 __user *)arg);
399 	}
400 
401 	return sk->sk_prot->ioctl(sk, cmd, arg);
402 }
403 
404 static int pn_socket_listen(struct socket *sock, int backlog)
405 {
406 	struct sock *sk = sock->sk;
407 	int err = 0;
408 
409 	if (pn_socket_autobind(sock))
410 		return -ENOBUFS;
411 
412 	lock_sock(sk);
413 	if (sock->state != SS_UNCONNECTED) {
414 		err = -EINVAL;
415 		goto out;
416 	}
417 
418 	if (sk->sk_state != TCP_LISTEN) {
419 		sk->sk_state = TCP_LISTEN;
420 		sk->sk_ack_backlog = 0;
421 	}
422 	sk->sk_max_ack_backlog = backlog;
423 out:
424 	release_sock(sk);
425 	return err;
426 }
427 
428 static int pn_socket_sendmsg(struct socket *sock, struct msghdr *m,
429 			     size_t total_len)
430 {
431 	struct sock *sk = sock->sk;
432 
433 	if (pn_socket_autobind(sock))
434 		return -EAGAIN;
435 
436 	return sk->sk_prot->sendmsg(sk, m, total_len);
437 }
438 
439 const struct proto_ops phonet_dgram_ops = {
440 	.family		= AF_PHONET,
441 	.owner		= THIS_MODULE,
442 	.release	= pn_socket_release,
443 	.bind		= pn_socket_bind,
444 	.connect	= sock_no_connect,
445 	.socketpair	= sock_no_socketpair,
446 	.accept		= sock_no_accept,
447 	.getname	= pn_socket_getname,
448 	.poll		= datagram_poll,
449 	.ioctl		= pn_socket_ioctl,
450 	.listen		= sock_no_listen,
451 	.shutdown	= sock_no_shutdown,
452 	.setsockopt	= sock_no_setsockopt,
453 	.getsockopt	= sock_no_getsockopt,
454 #ifdef CONFIG_COMPAT
455 	.compat_setsockopt = sock_no_setsockopt,
456 	.compat_getsockopt = sock_no_getsockopt,
457 #endif
458 	.sendmsg	= pn_socket_sendmsg,
459 	.recvmsg	= sock_common_recvmsg,
460 	.mmap		= sock_no_mmap,
461 	.sendpage	= sock_no_sendpage,
462 };
463 
464 const struct proto_ops phonet_stream_ops = {
465 	.family		= AF_PHONET,
466 	.owner		= THIS_MODULE,
467 	.release	= pn_socket_release,
468 	.bind		= pn_socket_bind,
469 	.connect	= pn_socket_connect,
470 	.socketpair	= sock_no_socketpair,
471 	.accept		= pn_socket_accept,
472 	.getname	= pn_socket_getname,
473 	.poll		= pn_socket_poll,
474 	.ioctl		= pn_socket_ioctl,
475 	.listen		= pn_socket_listen,
476 	.shutdown	= sock_no_shutdown,
477 	.setsockopt	= sock_common_setsockopt,
478 	.getsockopt	= sock_common_getsockopt,
479 #ifdef CONFIG_COMPAT
480 	.compat_setsockopt = compat_sock_common_setsockopt,
481 	.compat_getsockopt = compat_sock_common_getsockopt,
482 #endif
483 	.sendmsg	= pn_socket_sendmsg,
484 	.recvmsg	= sock_common_recvmsg,
485 	.mmap		= sock_no_mmap,
486 	.sendpage	= sock_no_sendpage,
487 };
488 EXPORT_SYMBOL(phonet_stream_ops);
489 
490 /* allocate port for a socket */
491 int pn_sock_get_port(struct sock *sk, unsigned short sport)
492 {
493 	static int port_cur;
494 	struct net *net = sock_net(sk);
495 	struct pn_sock *pn = pn_sk(sk);
496 	struct sockaddr_pn try_sa;
497 	struct sock *tmpsk;
498 
499 	memset(&try_sa, 0, sizeof(struct sockaddr_pn));
500 	try_sa.spn_family = AF_PHONET;
501 	WARN_ON(!mutex_is_locked(&port_mutex));
502 	if (!sport) {
503 		/* search free port */
504 		int port, pmin, pmax;
505 
506 		phonet_get_local_port_range(&pmin, &pmax);
507 		for (port = pmin; port <= pmax; port++) {
508 			port_cur++;
509 			if (port_cur < pmin || port_cur > pmax)
510 				port_cur = pmin;
511 
512 			pn_sockaddr_set_port(&try_sa, port_cur);
513 			tmpsk = pn_find_sock_by_sa(net, &try_sa);
514 			if (tmpsk == NULL) {
515 				sport = port_cur;
516 				goto found;
517 			} else
518 				sock_put(tmpsk);
519 		}
520 	} else {
521 		/* try to find specific port */
522 		pn_sockaddr_set_port(&try_sa, sport);
523 		tmpsk = pn_find_sock_by_sa(net, &try_sa);
524 		if (tmpsk == NULL)
525 			/* No sock there! We can use that port... */
526 			goto found;
527 		else
528 			sock_put(tmpsk);
529 	}
530 	/* the port must be in use already */
531 	return -EADDRINUSE;
532 
533 found:
534 	pn->sobject = pn_object(pn_addr(pn->sobject), sport);
535 	return 0;
536 }
537 EXPORT_SYMBOL(pn_sock_get_port);
538 
539 #ifdef CONFIG_PROC_FS
540 static struct sock *pn_sock_get_idx(struct seq_file *seq, loff_t pos)
541 {
542 	struct net *net = seq_file_net(seq);
543 	struct hlist_head *hlist = pnsocks.hlist;
544 	struct sock *sknode;
545 	unsigned int h;
546 
547 	for (h = 0; h < PN_HASHSIZE; h++) {
548 		sk_for_each_rcu(sknode, hlist) {
549 			if (!net_eq(net, sock_net(sknode)))
550 				continue;
551 			if (!pos)
552 				return sknode;
553 			pos--;
554 		}
555 		hlist++;
556 	}
557 	return NULL;
558 }
559 
560 static struct sock *pn_sock_get_next(struct seq_file *seq, struct sock *sk)
561 {
562 	struct net *net = seq_file_net(seq);
563 
564 	do
565 		sk = sk_next(sk);
566 	while (sk && !net_eq(net, sock_net(sk)));
567 
568 	return sk;
569 }
570 
571 static void *pn_sock_seq_start(struct seq_file *seq, loff_t *pos)
572 	__acquires(rcu)
573 {
574 	rcu_read_lock();
575 	return *pos ? pn_sock_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
576 }
577 
578 static void *pn_sock_seq_next(struct seq_file *seq, void *v, loff_t *pos)
579 {
580 	struct sock *sk;
581 
582 	if (v == SEQ_START_TOKEN)
583 		sk = pn_sock_get_idx(seq, 0);
584 	else
585 		sk = pn_sock_get_next(seq, v);
586 	(*pos)++;
587 	return sk;
588 }
589 
590 static void pn_sock_seq_stop(struct seq_file *seq, void *v)
591 	__releases(rcu)
592 {
593 	rcu_read_unlock();
594 }
595 
596 static int pn_sock_seq_show(struct seq_file *seq, void *v)
597 {
598 	seq_setwidth(seq, 127);
599 	if (v == SEQ_START_TOKEN)
600 		seq_puts(seq, "pt  loc  rem rs st tx_queue rx_queue "
601 			"  uid inode ref pointer drops");
602 	else {
603 		struct sock *sk = v;
604 		struct pn_sock *pn = pn_sk(sk);
605 
606 		seq_printf(seq, "%2d %04X:%04X:%02X %02X %08X:%08X %5d %lu "
607 			"%d %pK %d",
608 			sk->sk_protocol, pn->sobject, pn->dobject,
609 			pn->resource, sk->sk_state,
610 			sk_wmem_alloc_get(sk), sk_rmem_alloc_get(sk),
611 			from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)),
612 			sock_i_ino(sk),
613 			atomic_read(&sk->sk_refcnt), sk,
614 			atomic_read(&sk->sk_drops));
615 	}
616 	seq_pad(seq, '\n');
617 	return 0;
618 }
619 
620 static const struct seq_operations pn_sock_seq_ops = {
621 	.start = pn_sock_seq_start,
622 	.next = pn_sock_seq_next,
623 	.stop = pn_sock_seq_stop,
624 	.show = pn_sock_seq_show,
625 };
626 
627 static int pn_sock_open(struct inode *inode, struct file *file)
628 {
629 	return seq_open_net(inode, file, &pn_sock_seq_ops,
630 				sizeof(struct seq_net_private));
631 }
632 
633 const struct file_operations pn_sock_seq_fops = {
634 	.owner = THIS_MODULE,
635 	.open = pn_sock_open,
636 	.read = seq_read,
637 	.llseek = seq_lseek,
638 	.release = seq_release_net,
639 };
640 #endif
641 
642 static struct  {
643 	struct sock *sk[256];
644 } pnres;
645 
646 /*
647  * Find and hold socket based on resource.
648  */
649 struct sock *pn_find_sock_by_res(struct net *net, u8 res)
650 {
651 	struct sock *sk;
652 
653 	if (!net_eq(net, &init_net))
654 		return NULL;
655 
656 	rcu_read_lock();
657 	sk = rcu_dereference(pnres.sk[res]);
658 	if (sk)
659 		sock_hold(sk);
660 	rcu_read_unlock();
661 	return sk;
662 }
663 
664 static DEFINE_MUTEX(resource_mutex);
665 
666 int pn_sock_bind_res(struct sock *sk, u8 res)
667 {
668 	int ret = -EADDRINUSE;
669 
670 	if (!net_eq(sock_net(sk), &init_net))
671 		return -ENOIOCTLCMD;
672 	if (!capable(CAP_SYS_ADMIN))
673 		return -EPERM;
674 	if (pn_socket_autobind(sk->sk_socket))
675 		return -EAGAIN;
676 
677 	mutex_lock(&resource_mutex);
678 	if (pnres.sk[res] == NULL) {
679 		sock_hold(sk);
680 		rcu_assign_pointer(pnres.sk[res], sk);
681 		ret = 0;
682 	}
683 	mutex_unlock(&resource_mutex);
684 	return ret;
685 }
686 
687 int pn_sock_unbind_res(struct sock *sk, u8 res)
688 {
689 	int ret = -ENOENT;
690 
691 	if (!capable(CAP_SYS_ADMIN))
692 		return -EPERM;
693 
694 	mutex_lock(&resource_mutex);
695 	if (pnres.sk[res] == sk) {
696 		RCU_INIT_POINTER(pnres.sk[res], NULL);
697 		ret = 0;
698 	}
699 	mutex_unlock(&resource_mutex);
700 
701 	if (ret == 0) {
702 		synchronize_rcu();
703 		sock_put(sk);
704 	}
705 	return ret;
706 }
707 
708 void pn_sock_unbind_all_res(struct sock *sk)
709 {
710 	unsigned int res, match = 0;
711 
712 	mutex_lock(&resource_mutex);
713 	for (res = 0; res < 256; res++) {
714 		if (pnres.sk[res] == sk) {
715 			RCU_INIT_POINTER(pnres.sk[res], NULL);
716 			match++;
717 		}
718 	}
719 	mutex_unlock(&resource_mutex);
720 
721 	while (match > 0) {
722 		__sock_put(sk);
723 		match--;
724 	}
725 	/* Caller is responsible for RCU sync before final sock_put() */
726 }
727 
728 #ifdef CONFIG_PROC_FS
729 static struct sock **pn_res_get_idx(struct seq_file *seq, loff_t pos)
730 {
731 	struct net *net = seq_file_net(seq);
732 	unsigned int i;
733 
734 	if (!net_eq(net, &init_net))
735 		return NULL;
736 
737 	for (i = 0; i < 256; i++) {
738 		if (pnres.sk[i] == NULL)
739 			continue;
740 		if (!pos)
741 			return pnres.sk + i;
742 		pos--;
743 	}
744 	return NULL;
745 }
746 
747 static struct sock **pn_res_get_next(struct seq_file *seq, struct sock **sk)
748 {
749 	struct net *net = seq_file_net(seq);
750 	unsigned int i;
751 
752 	BUG_ON(!net_eq(net, &init_net));
753 
754 	for (i = (sk - pnres.sk) + 1; i < 256; i++)
755 		if (pnres.sk[i])
756 			return pnres.sk + i;
757 	return NULL;
758 }
759 
760 static void *pn_res_seq_start(struct seq_file *seq, loff_t *pos)
761 	__acquires(resource_mutex)
762 {
763 	mutex_lock(&resource_mutex);
764 	return *pos ? pn_res_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
765 }
766 
767 static void *pn_res_seq_next(struct seq_file *seq, void *v, loff_t *pos)
768 {
769 	struct sock **sk;
770 
771 	if (v == SEQ_START_TOKEN)
772 		sk = pn_res_get_idx(seq, 0);
773 	else
774 		sk = pn_res_get_next(seq, v);
775 	(*pos)++;
776 	return sk;
777 }
778 
779 static void pn_res_seq_stop(struct seq_file *seq, void *v)
780 	__releases(resource_mutex)
781 {
782 	mutex_unlock(&resource_mutex);
783 }
784 
785 static int pn_res_seq_show(struct seq_file *seq, void *v)
786 {
787 	seq_setwidth(seq, 63);
788 	if (v == SEQ_START_TOKEN)
789 		seq_puts(seq, "rs   uid inode");
790 	else {
791 		struct sock **psk = v;
792 		struct sock *sk = *psk;
793 
794 		seq_printf(seq, "%02X %5u %lu",
795 			   (int) (psk - pnres.sk),
796 			   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)),
797 			   sock_i_ino(sk));
798 	}
799 	seq_pad(seq, '\n');
800 	return 0;
801 }
802 
803 static const struct seq_operations pn_res_seq_ops = {
804 	.start = pn_res_seq_start,
805 	.next = pn_res_seq_next,
806 	.stop = pn_res_seq_stop,
807 	.show = pn_res_seq_show,
808 };
809 
810 static int pn_res_open(struct inode *inode, struct file *file)
811 {
812 	return seq_open_net(inode, file, &pn_res_seq_ops,
813 				sizeof(struct seq_net_private));
814 }
815 
816 const struct file_operations pn_res_seq_fops = {
817 	.owner = THIS_MODULE,
818 	.open = pn_res_open,
819 	.read = seq_read,
820 	.llseek = seq_lseek,
821 	.release = seq_release_net,
822 };
823 #endif
824