xref: /linux/net/phonet/socket.c (revision 4413e16d9d21673bb5048a2e542f1aaa00015c2e)
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 hlist_node *node;
80 	struct sock *sknode;
81 	struct sock *rval = NULL;
82 	u16 obj = pn_sockaddr_get_object(spn);
83 	u8 res = spn->spn_resource;
84 	struct hlist_head *hlist = pn_hash_list(obj);
85 
86 	rcu_read_lock();
87 	sk_for_each_rcu(sknode, node, hlist) {
88 		struct pn_sock *pn = pn_sk(sknode);
89 		BUG_ON(!pn->sobject); /* unbound socket */
90 
91 		if (!net_eq(sock_net(sknode), net))
92 			continue;
93 		if (pn_port(obj)) {
94 			/* Look up socket by port */
95 			if (pn_port(pn->sobject) != pn_port(obj))
96 				continue;
97 		} else {
98 			/* If port is zero, look up by resource */
99 			if (pn->resource != res)
100 				continue;
101 		}
102 		if (pn_addr(pn->sobject) &&
103 		    pn_addr(pn->sobject) != pn_addr(obj))
104 			continue;
105 
106 		rval = sknode;
107 		sock_hold(sknode);
108 		break;
109 	}
110 	rcu_read_unlock();
111 
112 	return rval;
113 }
114 
115 /* Deliver a broadcast packet (only in bottom-half) */
116 void pn_deliver_sock_broadcast(struct net *net, struct sk_buff *skb)
117 {
118 	struct hlist_head *hlist = pnsocks.hlist;
119 	unsigned int h;
120 
121 	rcu_read_lock();
122 	for (h = 0; h < PN_HASHSIZE; h++) {
123 		struct hlist_node *node;
124 		struct sock *sknode;
125 
126 		sk_for_each(sknode, node, hlist) {
127 			struct sk_buff *clone;
128 
129 			if (!net_eq(sock_net(sknode), net))
130 				continue;
131 			if (!sock_flag(sknode, SOCK_BROADCAST))
132 				continue;
133 
134 			clone = skb_clone(skb, GFP_ATOMIC);
135 			if (clone) {
136 				sock_hold(sknode);
137 				sk_receive_skb(sknode, clone, 0);
138 			}
139 		}
140 		hlist++;
141 	}
142 	rcu_read_unlock();
143 }
144 
145 void pn_sock_hash(struct sock *sk)
146 {
147 	struct hlist_head *hlist = pn_hash_list(pn_sk(sk)->sobject);
148 
149 	mutex_lock(&pnsocks.lock);
150 	sk_add_node_rcu(sk, hlist);
151 	mutex_unlock(&pnsocks.lock);
152 }
153 EXPORT_SYMBOL(pn_sock_hash);
154 
155 void pn_sock_unhash(struct sock *sk)
156 {
157 	mutex_lock(&pnsocks.lock);
158 	sk_del_node_init_rcu(sk);
159 	mutex_unlock(&pnsocks.lock);
160 	pn_sock_unbind_all_res(sk);
161 	synchronize_rcu();
162 }
163 EXPORT_SYMBOL(pn_sock_unhash);
164 
165 static DEFINE_MUTEX(port_mutex);
166 
167 static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
168 {
169 	struct sock *sk = sock->sk;
170 	struct pn_sock *pn = pn_sk(sk);
171 	struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
172 	int err;
173 	u16 handle;
174 	u8 saddr;
175 
176 	if (sk->sk_prot->bind)
177 		return sk->sk_prot->bind(sk, addr, len);
178 
179 	if (len < sizeof(struct sockaddr_pn))
180 		return -EINVAL;
181 	if (spn->spn_family != AF_PHONET)
182 		return -EAFNOSUPPORT;
183 
184 	handle = pn_sockaddr_get_object((struct sockaddr_pn *)addr);
185 	saddr = pn_addr(handle);
186 	if (saddr && phonet_address_lookup(sock_net(sk), saddr))
187 		return -EADDRNOTAVAIL;
188 
189 	lock_sock(sk);
190 	if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
191 		err = -EINVAL; /* attempt to rebind */
192 		goto out;
193 	}
194 	WARN_ON(sk_hashed(sk));
195 	mutex_lock(&port_mutex);
196 	err = sk->sk_prot->get_port(sk, pn_port(handle));
197 	if (err)
198 		goto out_port;
199 
200 	/* get_port() sets the port, bind() sets the address if applicable */
201 	pn->sobject = pn_object(saddr, pn_port(pn->sobject));
202 	pn->resource = spn->spn_resource;
203 
204 	/* Enable RX on the socket */
205 	sk->sk_prot->hash(sk);
206 out_port:
207 	mutex_unlock(&port_mutex);
208 out:
209 	release_sock(sk);
210 	return err;
211 }
212 
213 static int pn_socket_autobind(struct socket *sock)
214 {
215 	struct sockaddr_pn sa;
216 	int err;
217 
218 	memset(&sa, 0, sizeof(sa));
219 	sa.spn_family = AF_PHONET;
220 	err = pn_socket_bind(sock, (struct sockaddr *)&sa,
221 				sizeof(struct sockaddr_pn));
222 	if (err != -EINVAL)
223 		return err;
224 	BUG_ON(!pn_port(pn_sk(sock->sk)->sobject));
225 	return 0; /* socket was already bound */
226 }
227 
228 static int pn_socket_connect(struct socket *sock, struct sockaddr *addr,
229 		int len, int flags)
230 {
231 	struct sock *sk = sock->sk;
232 	struct pn_sock *pn = pn_sk(sk);
233 	struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
234 	struct task_struct *tsk = current;
235 	long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
236 	int err;
237 
238 	if (pn_socket_autobind(sock))
239 		return -ENOBUFS;
240 	if (len < sizeof(struct sockaddr_pn))
241 		return -EINVAL;
242 	if (spn->spn_family != AF_PHONET)
243 		return -EAFNOSUPPORT;
244 
245 	lock_sock(sk);
246 
247 	switch (sock->state) {
248 	case SS_UNCONNECTED:
249 		if (sk->sk_state != TCP_CLOSE) {
250 			err = -EISCONN;
251 			goto out;
252 		}
253 		break;
254 	case SS_CONNECTING:
255 		err = -EALREADY;
256 		goto out;
257 	default:
258 		err = -EISCONN;
259 		goto out;
260 	}
261 
262 	pn->dobject = pn_sockaddr_get_object(spn);
263 	pn->resource = pn_sockaddr_get_resource(spn);
264 	sock->state = SS_CONNECTING;
265 
266 	err = sk->sk_prot->connect(sk, addr, len);
267 	if (err) {
268 		sock->state = SS_UNCONNECTED;
269 		pn->dobject = 0;
270 		goto out;
271 	}
272 
273 	while (sk->sk_state == TCP_SYN_SENT) {
274 		DEFINE_WAIT(wait);
275 
276 		if (!timeo) {
277 			err = -EINPROGRESS;
278 			goto out;
279 		}
280 		if (signal_pending(tsk)) {
281 			err = sock_intr_errno(timeo);
282 			goto out;
283 		}
284 
285 		prepare_to_wait_exclusive(sk_sleep(sk), &wait,
286 						TASK_INTERRUPTIBLE);
287 		release_sock(sk);
288 		timeo = schedule_timeout(timeo);
289 		lock_sock(sk);
290 		finish_wait(sk_sleep(sk), &wait);
291 	}
292 
293 	if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED))
294 		err = 0;
295 	else if (sk->sk_state == TCP_CLOSE_WAIT)
296 		err = -ECONNRESET;
297 	else
298 		err = -ECONNREFUSED;
299 	sock->state = err ? SS_UNCONNECTED : SS_CONNECTED;
300 out:
301 	release_sock(sk);
302 	return err;
303 }
304 
305 static int pn_socket_accept(struct socket *sock, struct socket *newsock,
306 				int flags)
307 {
308 	struct sock *sk = sock->sk;
309 	struct sock *newsk;
310 	int err;
311 
312 	if (unlikely(sk->sk_state != TCP_LISTEN))
313 		return -EINVAL;
314 
315 	newsk = sk->sk_prot->accept(sk, flags, &err);
316 	if (!newsk)
317 		return err;
318 
319 	lock_sock(newsk);
320 	sock_graft(newsk, newsock);
321 	newsock->state = SS_CONNECTED;
322 	release_sock(newsk);
323 	return 0;
324 }
325 
326 static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
327 				int *sockaddr_len, int peer)
328 {
329 	struct sock *sk = sock->sk;
330 	struct pn_sock *pn = pn_sk(sk);
331 
332 	memset(addr, 0, sizeof(struct sockaddr_pn));
333 	addr->sa_family = AF_PHONET;
334 	if (!peer) /* Race with bind() here is userland's problem. */
335 		pn_sockaddr_set_object((struct sockaddr_pn *)addr,
336 					pn->sobject);
337 
338 	*sockaddr_len = sizeof(struct sockaddr_pn);
339 	return 0;
340 }
341 
342 static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
343 					poll_table *wait)
344 {
345 	struct sock *sk = sock->sk;
346 	struct pep_sock *pn = pep_sk(sk);
347 	unsigned int mask = 0;
348 
349 	poll_wait(file, sk_sleep(sk), wait);
350 
351 	if (sk->sk_state == TCP_CLOSE)
352 		return POLLERR;
353 	if (!skb_queue_empty(&sk->sk_receive_queue))
354 		mask |= POLLIN | POLLRDNORM;
355 	if (!skb_queue_empty(&pn->ctrlreq_queue))
356 		mask |= POLLPRI;
357 	if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
358 		return POLLHUP;
359 
360 	if (sk->sk_state == TCP_ESTABLISHED &&
361 		atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf &&
362 		atomic_read(&pn->tx_credits))
363 		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
364 
365 	return mask;
366 }
367 
368 static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
369 				unsigned long arg)
370 {
371 	struct sock *sk = sock->sk;
372 	struct pn_sock *pn = pn_sk(sk);
373 
374 	if (cmd == SIOCPNGETOBJECT) {
375 		struct net_device *dev;
376 		u16 handle;
377 		u8 saddr;
378 
379 		if (get_user(handle, (__u16 __user *)arg))
380 			return -EFAULT;
381 
382 		lock_sock(sk);
383 		if (sk->sk_bound_dev_if)
384 			dev = dev_get_by_index(sock_net(sk),
385 						sk->sk_bound_dev_if);
386 		else
387 			dev = phonet_device_get(sock_net(sk));
388 		if (dev && (dev->flags & IFF_UP))
389 			saddr = phonet_address_get(dev, pn_addr(handle));
390 		else
391 			saddr = PN_NO_ADDR;
392 		release_sock(sk);
393 
394 		if (dev)
395 			dev_put(dev);
396 		if (saddr == PN_NO_ADDR)
397 			return -EHOSTUNREACH;
398 
399 		handle = pn_object(saddr, pn_port(pn->sobject));
400 		return put_user(handle, (__u16 __user *)arg);
401 	}
402 
403 	return sk->sk_prot->ioctl(sk, cmd, arg);
404 }
405 
406 static int pn_socket_listen(struct socket *sock, int backlog)
407 {
408 	struct sock *sk = sock->sk;
409 	int err = 0;
410 
411 	if (pn_socket_autobind(sock))
412 		return -ENOBUFS;
413 
414 	lock_sock(sk);
415 	if (sock->state != SS_UNCONNECTED) {
416 		err = -EINVAL;
417 		goto out;
418 	}
419 
420 	if (sk->sk_state != TCP_LISTEN) {
421 		sk->sk_state = TCP_LISTEN;
422 		sk->sk_ack_backlog = 0;
423 	}
424 	sk->sk_max_ack_backlog = backlog;
425 out:
426 	release_sock(sk);
427 	return err;
428 }
429 
430 static int pn_socket_sendmsg(struct kiocb *iocb, struct socket *sock,
431 				struct msghdr *m, size_t total_len)
432 {
433 	struct sock *sk = sock->sk;
434 
435 	if (pn_socket_autobind(sock))
436 		return -EAGAIN;
437 
438 	return sk->sk_prot->sendmsg(iocb, sk, m, total_len);
439 }
440 
441 const struct proto_ops phonet_dgram_ops = {
442 	.family		= AF_PHONET,
443 	.owner		= THIS_MODULE,
444 	.release	= pn_socket_release,
445 	.bind		= pn_socket_bind,
446 	.connect	= sock_no_connect,
447 	.socketpair	= sock_no_socketpair,
448 	.accept		= sock_no_accept,
449 	.getname	= pn_socket_getname,
450 	.poll		= datagram_poll,
451 	.ioctl		= pn_socket_ioctl,
452 	.listen		= sock_no_listen,
453 	.shutdown	= sock_no_shutdown,
454 	.setsockopt	= sock_no_setsockopt,
455 	.getsockopt	= sock_no_getsockopt,
456 #ifdef CONFIG_COMPAT
457 	.compat_setsockopt = sock_no_setsockopt,
458 	.compat_getsockopt = sock_no_getsockopt,
459 #endif
460 	.sendmsg	= pn_socket_sendmsg,
461 	.recvmsg	= sock_common_recvmsg,
462 	.mmap		= sock_no_mmap,
463 	.sendpage	= sock_no_sendpage,
464 };
465 
466 const struct proto_ops phonet_stream_ops = {
467 	.family		= AF_PHONET,
468 	.owner		= THIS_MODULE,
469 	.release	= pn_socket_release,
470 	.bind		= pn_socket_bind,
471 	.connect	= pn_socket_connect,
472 	.socketpair	= sock_no_socketpair,
473 	.accept		= pn_socket_accept,
474 	.getname	= pn_socket_getname,
475 	.poll		= pn_socket_poll,
476 	.ioctl		= pn_socket_ioctl,
477 	.listen		= pn_socket_listen,
478 	.shutdown	= sock_no_shutdown,
479 	.setsockopt	= sock_common_setsockopt,
480 	.getsockopt	= sock_common_getsockopt,
481 #ifdef CONFIG_COMPAT
482 	.compat_setsockopt = compat_sock_common_setsockopt,
483 	.compat_getsockopt = compat_sock_common_getsockopt,
484 #endif
485 	.sendmsg	= pn_socket_sendmsg,
486 	.recvmsg	= sock_common_recvmsg,
487 	.mmap		= sock_no_mmap,
488 	.sendpage	= sock_no_sendpage,
489 };
490 EXPORT_SYMBOL(phonet_stream_ops);
491 
492 /* allocate port for a socket */
493 int pn_sock_get_port(struct sock *sk, unsigned short sport)
494 {
495 	static int port_cur;
496 	struct net *net = sock_net(sk);
497 	struct pn_sock *pn = pn_sk(sk);
498 	struct sockaddr_pn try_sa;
499 	struct sock *tmpsk;
500 
501 	memset(&try_sa, 0, sizeof(struct sockaddr_pn));
502 	try_sa.spn_family = AF_PHONET;
503 	WARN_ON(!mutex_is_locked(&port_mutex));
504 	if (!sport) {
505 		/* search free port */
506 		int port, pmin, pmax;
507 
508 		phonet_get_local_port_range(&pmin, &pmax);
509 		for (port = pmin; port <= pmax; port++) {
510 			port_cur++;
511 			if (port_cur < pmin || port_cur > pmax)
512 				port_cur = pmin;
513 
514 			pn_sockaddr_set_port(&try_sa, port_cur);
515 			tmpsk = pn_find_sock_by_sa(net, &try_sa);
516 			if (tmpsk == NULL) {
517 				sport = port_cur;
518 				goto found;
519 			} else
520 				sock_put(tmpsk);
521 		}
522 	} else {
523 		/* try to find specific port */
524 		pn_sockaddr_set_port(&try_sa, sport);
525 		tmpsk = pn_find_sock_by_sa(net, &try_sa);
526 		if (tmpsk == NULL)
527 			/* No sock there! We can use that port... */
528 			goto found;
529 		else
530 			sock_put(tmpsk);
531 	}
532 	/* the port must be in use already */
533 	return -EADDRINUSE;
534 
535 found:
536 	pn->sobject = pn_object(pn_addr(pn->sobject), sport);
537 	return 0;
538 }
539 EXPORT_SYMBOL(pn_sock_get_port);
540 
541 #ifdef CONFIG_PROC_FS
542 static struct sock *pn_sock_get_idx(struct seq_file *seq, loff_t pos)
543 {
544 	struct net *net = seq_file_net(seq);
545 	struct hlist_head *hlist = pnsocks.hlist;
546 	struct hlist_node *node;
547 	struct sock *sknode;
548 	unsigned int h;
549 
550 	for (h = 0; h < PN_HASHSIZE; h++) {
551 		sk_for_each_rcu(sknode, node, hlist) {
552 			if (!net_eq(net, sock_net(sknode)))
553 				continue;
554 			if (!pos)
555 				return sknode;
556 			pos--;
557 		}
558 		hlist++;
559 	}
560 	return NULL;
561 }
562 
563 static struct sock *pn_sock_get_next(struct seq_file *seq, struct sock *sk)
564 {
565 	struct net *net = seq_file_net(seq);
566 
567 	do
568 		sk = sk_next(sk);
569 	while (sk && !net_eq(net, sock_net(sk)));
570 
571 	return sk;
572 }
573 
574 static void *pn_sock_seq_start(struct seq_file *seq, loff_t *pos)
575 	__acquires(rcu)
576 {
577 	rcu_read_lock();
578 	return *pos ? pn_sock_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
579 }
580 
581 static void *pn_sock_seq_next(struct seq_file *seq, void *v, loff_t *pos)
582 {
583 	struct sock *sk;
584 
585 	if (v == SEQ_START_TOKEN)
586 		sk = pn_sock_get_idx(seq, 0);
587 	else
588 		sk = pn_sock_get_next(seq, v);
589 	(*pos)++;
590 	return sk;
591 }
592 
593 static void pn_sock_seq_stop(struct seq_file *seq, void *v)
594 	__releases(rcu)
595 {
596 	rcu_read_unlock();
597 }
598 
599 static int pn_sock_seq_show(struct seq_file *seq, void *v)
600 {
601 	int len;
602 
603 	if (v == SEQ_START_TOKEN)
604 		seq_printf(seq, "%s%n", "pt  loc  rem rs st tx_queue rx_queue "
605 			"  uid inode ref pointer drops", &len);
606 	else {
607 		struct sock *sk = v;
608 		struct pn_sock *pn = pn_sk(sk);
609 
610 		seq_printf(seq, "%2d %04X:%04X:%02X %02X %08X:%08X %5d %lu "
611 			"%d %pK %d%n",
612 			sk->sk_protocol, pn->sobject, pn->dobject,
613 			pn->resource, sk->sk_state,
614 			sk_wmem_alloc_get(sk), sk_rmem_alloc_get(sk),
615 			sock_i_uid(sk), sock_i_ino(sk),
616 			atomic_read(&sk->sk_refcnt), sk,
617 			atomic_read(&sk->sk_drops), &len);
618 	}
619 	seq_printf(seq, "%*s\n", 127 - len, "");
620 	return 0;
621 }
622 
623 static const struct seq_operations pn_sock_seq_ops = {
624 	.start = pn_sock_seq_start,
625 	.next = pn_sock_seq_next,
626 	.stop = pn_sock_seq_stop,
627 	.show = pn_sock_seq_show,
628 };
629 
630 static int pn_sock_open(struct inode *inode, struct file *file)
631 {
632 	return seq_open_net(inode, file, &pn_sock_seq_ops,
633 				sizeof(struct seq_net_private));
634 }
635 
636 const struct file_operations pn_sock_seq_fops = {
637 	.owner = THIS_MODULE,
638 	.open = pn_sock_open,
639 	.read = seq_read,
640 	.llseek = seq_lseek,
641 	.release = seq_release_net,
642 };
643 #endif
644 
645 static struct  {
646 	struct sock *sk[256];
647 } pnres;
648 
649 /*
650  * Find and hold socket based on resource.
651  */
652 struct sock *pn_find_sock_by_res(struct net *net, u8 res)
653 {
654 	struct sock *sk;
655 
656 	if (!net_eq(net, &init_net))
657 		return NULL;
658 
659 	rcu_read_lock();
660 	sk = rcu_dereference(pnres.sk[res]);
661 	if (sk)
662 		sock_hold(sk);
663 	rcu_read_unlock();
664 	return sk;
665 }
666 
667 static DEFINE_MUTEX(resource_mutex);
668 
669 int pn_sock_bind_res(struct sock *sk, u8 res)
670 {
671 	int ret = -EADDRINUSE;
672 
673 	if (!net_eq(sock_net(sk), &init_net))
674 		return -ENOIOCTLCMD;
675 	if (!capable(CAP_SYS_ADMIN))
676 		return -EPERM;
677 	if (pn_socket_autobind(sk->sk_socket))
678 		return -EAGAIN;
679 
680 	mutex_lock(&resource_mutex);
681 	if (pnres.sk[res] == NULL) {
682 		sock_hold(sk);
683 		rcu_assign_pointer(pnres.sk[res], sk);
684 		ret = 0;
685 	}
686 	mutex_unlock(&resource_mutex);
687 	return ret;
688 }
689 
690 int pn_sock_unbind_res(struct sock *sk, u8 res)
691 {
692 	int ret = -ENOENT;
693 
694 	if (!capable(CAP_SYS_ADMIN))
695 		return -EPERM;
696 
697 	mutex_lock(&resource_mutex);
698 	if (pnres.sk[res] == sk) {
699 		RCU_INIT_POINTER(pnres.sk[res], NULL);
700 		ret = 0;
701 	}
702 	mutex_unlock(&resource_mutex);
703 
704 	if (ret == 0) {
705 		synchronize_rcu();
706 		sock_put(sk);
707 	}
708 	return ret;
709 }
710 
711 void pn_sock_unbind_all_res(struct sock *sk)
712 {
713 	unsigned int res, match = 0;
714 
715 	mutex_lock(&resource_mutex);
716 	for (res = 0; res < 256; res++) {
717 		if (pnres.sk[res] == sk) {
718 			RCU_INIT_POINTER(pnres.sk[res], NULL);
719 			match++;
720 		}
721 	}
722 	mutex_unlock(&resource_mutex);
723 
724 	while (match > 0) {
725 		__sock_put(sk);
726 		match--;
727 	}
728 	/* Caller is responsible for RCU sync before final sock_put() */
729 }
730 
731 #ifdef CONFIG_PROC_FS
732 static struct sock **pn_res_get_idx(struct seq_file *seq, loff_t pos)
733 {
734 	struct net *net = seq_file_net(seq);
735 	unsigned int i;
736 
737 	if (!net_eq(net, &init_net))
738 		return NULL;
739 
740 	for (i = 0; i < 256; i++) {
741 		if (pnres.sk[i] == NULL)
742 			continue;
743 		if (!pos)
744 			return pnres.sk + i;
745 		pos--;
746 	}
747 	return NULL;
748 }
749 
750 static struct sock **pn_res_get_next(struct seq_file *seq, struct sock **sk)
751 {
752 	struct net *net = seq_file_net(seq);
753 	unsigned int i;
754 
755 	BUG_ON(!net_eq(net, &init_net));
756 
757 	for (i = (sk - pnres.sk) + 1; i < 256; i++)
758 		if (pnres.sk[i])
759 			return pnres.sk + i;
760 	return NULL;
761 }
762 
763 static void *pn_res_seq_start(struct seq_file *seq, loff_t *pos)
764 	__acquires(resource_mutex)
765 {
766 	mutex_lock(&resource_mutex);
767 	return *pos ? pn_res_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
768 }
769 
770 static void *pn_res_seq_next(struct seq_file *seq, void *v, loff_t *pos)
771 {
772 	struct sock **sk;
773 
774 	if (v == SEQ_START_TOKEN)
775 		sk = pn_res_get_idx(seq, 0);
776 	else
777 		sk = pn_res_get_next(seq, v);
778 	(*pos)++;
779 	return sk;
780 }
781 
782 static void pn_res_seq_stop(struct seq_file *seq, void *v)
783 	__releases(resource_mutex)
784 {
785 	mutex_unlock(&resource_mutex);
786 }
787 
788 static int pn_res_seq_show(struct seq_file *seq, void *v)
789 {
790 	int len;
791 
792 	if (v == SEQ_START_TOKEN)
793 		seq_printf(seq, "%s%n", "rs   uid inode", &len);
794 	else {
795 		struct sock **psk = v;
796 		struct sock *sk = *psk;
797 
798 		seq_printf(seq, "%02X %5d %lu%n",
799 			   (int) (psk - pnres.sk), sock_i_uid(sk),
800 			   sock_i_ino(sk), &len);
801 	}
802 	seq_printf(seq, "%*s\n", 63 - len, "");
803 	return 0;
804 }
805 
806 static const struct seq_operations pn_res_seq_ops = {
807 	.start = pn_res_seq_start,
808 	.next = pn_res_seq_next,
809 	.stop = pn_res_seq_stop,
810 	.show = pn_res_seq_show,
811 };
812 
813 static int pn_res_open(struct inode *inode, struct file *file)
814 {
815 	return seq_open_net(inode, file, &pn_res_seq_ops,
816 				sizeof(struct seq_net_private));
817 }
818 
819 const struct file_operations pn_res_seq_fops = {
820 	.owner = THIS_MODULE,
821 	.open = pn_res_open,
822 	.read = seq_read,
823 	.llseek = seq_lseek,
824 	.release = seq_release_net,
825 };
826 #endif
827