xref: /openbmc/linux/net/phonet/socket.c (revision aac5987a)
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 <linux/sched/signal.h>
31 
32 #include <net/sock.h>
33 #include <net/tcp_states.h>
34 
35 #include <linux/phonet.h>
36 #include <linux/export.h>
37 #include <net/phonet/phonet.h>
38 #include <net/phonet/pep.h>
39 #include <net/phonet/pn_dev.h>
40 
41 static int pn_socket_release(struct socket *sock)
42 {
43 	struct sock *sk = sock->sk;
44 
45 	if (sk) {
46 		sock->sk = NULL;
47 		sk->sk_prot->close(sk, 0);
48 	}
49 	return 0;
50 }
51 
52 #define PN_HASHSIZE	16
53 #define PN_HASHMASK	(PN_HASHSIZE-1)
54 
55 
56 static struct  {
57 	struct hlist_head hlist[PN_HASHSIZE];
58 	struct mutex lock;
59 } pnsocks;
60 
61 void __init pn_sock_init(void)
62 {
63 	unsigned int i;
64 
65 	for (i = 0; i < PN_HASHSIZE; i++)
66 		INIT_HLIST_HEAD(pnsocks.hlist + i);
67 	mutex_init(&pnsocks.lock);
68 }
69 
70 static struct hlist_head *pn_hash_list(u16 obj)
71 {
72 	return pnsocks.hlist + (obj & PN_HASHMASK);
73 }
74 
75 /*
76  * Find address based on socket address, match only certain fields.
77  * Also grab sock if it was found. Remember to sock_put it later.
78  */
79 struct sock *pn_find_sock_by_sa(struct net *net, const struct sockaddr_pn *spn)
80 {
81 	struct sock *sknode;
82 	struct sock *rval = NULL;
83 	u16 obj = pn_sockaddr_get_object(spn);
84 	u8 res = spn->spn_resource;
85 	struct hlist_head *hlist = pn_hash_list(obj);
86 
87 	rcu_read_lock();
88 	sk_for_each_rcu(sknode, hlist) {
89 		struct pn_sock *pn = pn_sk(sknode);
90 		BUG_ON(!pn->sobject); /* unbound socket */
91 
92 		if (!net_eq(sock_net(sknode), net))
93 			continue;
94 		if (pn_port(obj)) {
95 			/* Look up socket by port */
96 			if (pn_port(pn->sobject) != pn_port(obj))
97 				continue;
98 		} else {
99 			/* If port is zero, look up by resource */
100 			if (pn->resource != res)
101 				continue;
102 		}
103 		if (pn_addr(pn->sobject) &&
104 		    pn_addr(pn->sobject) != pn_addr(obj))
105 			continue;
106 
107 		rval = sknode;
108 		sock_hold(sknode);
109 		break;
110 	}
111 	rcu_read_unlock();
112 
113 	return rval;
114 }
115 
116 /* Deliver a broadcast packet (only in bottom-half) */
117 void pn_deliver_sock_broadcast(struct net *net, struct sk_buff *skb)
118 {
119 	struct hlist_head *hlist = pnsocks.hlist;
120 	unsigned int h;
121 
122 	rcu_read_lock();
123 	for (h = 0; h < PN_HASHSIZE; h++) {
124 		struct sock *sknode;
125 
126 		sk_for_each(sknode, 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 int 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 	return 0;
154 }
155 EXPORT_SYMBOL(pn_sock_hash);
156 
157 void pn_sock_unhash(struct sock *sk)
158 {
159 	mutex_lock(&pnsocks.lock);
160 	sk_del_node_init_rcu(sk);
161 	mutex_unlock(&pnsocks.lock);
162 	pn_sock_unbind_all_res(sk);
163 	synchronize_rcu();
164 }
165 EXPORT_SYMBOL(pn_sock_unhash);
166 
167 static DEFINE_MUTEX(port_mutex);
168 
169 static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
170 {
171 	struct sock *sk = sock->sk;
172 	struct pn_sock *pn = pn_sk(sk);
173 	struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
174 	int err;
175 	u16 handle;
176 	u8 saddr;
177 
178 	if (sk->sk_prot->bind)
179 		return sk->sk_prot->bind(sk, addr, len);
180 
181 	if (len < sizeof(struct sockaddr_pn))
182 		return -EINVAL;
183 	if (spn->spn_family != AF_PHONET)
184 		return -EAFNOSUPPORT;
185 
186 	handle = pn_sockaddr_get_object((struct sockaddr_pn *)addr);
187 	saddr = pn_addr(handle);
188 	if (saddr && phonet_address_lookup(sock_net(sk), saddr))
189 		return -EADDRNOTAVAIL;
190 
191 	lock_sock(sk);
192 	if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
193 		err = -EINVAL; /* attempt to rebind */
194 		goto out;
195 	}
196 	WARN_ON(sk_hashed(sk));
197 	mutex_lock(&port_mutex);
198 	err = sk->sk_prot->get_port(sk, pn_port(handle));
199 	if (err)
200 		goto out_port;
201 
202 	/* get_port() sets the port, bind() sets the address if applicable */
203 	pn->sobject = pn_object(saddr, pn_port(pn->sobject));
204 	pn->resource = spn->spn_resource;
205 
206 	/* Enable RX on the socket */
207 	err = sk->sk_prot->hash(sk);
208 out_port:
209 	mutex_unlock(&port_mutex);
210 out:
211 	release_sock(sk);
212 	return err;
213 }
214 
215 static int pn_socket_autobind(struct socket *sock)
216 {
217 	struct sockaddr_pn sa;
218 	int err;
219 
220 	memset(&sa, 0, sizeof(sa));
221 	sa.spn_family = AF_PHONET;
222 	err = pn_socket_bind(sock, (struct sockaddr *)&sa,
223 				sizeof(struct sockaddr_pn));
224 	if (err != -EINVAL)
225 		return err;
226 	BUG_ON(!pn_port(pn_sk(sock->sk)->sobject));
227 	return 0; /* socket was already bound */
228 }
229 
230 static int pn_socket_connect(struct socket *sock, struct sockaddr *addr,
231 		int len, int flags)
232 {
233 	struct sock *sk = sock->sk;
234 	struct pn_sock *pn = pn_sk(sk);
235 	struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
236 	struct task_struct *tsk = current;
237 	long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
238 	int err;
239 
240 	if (pn_socket_autobind(sock))
241 		return -ENOBUFS;
242 	if (len < sizeof(struct sockaddr_pn))
243 		return -EINVAL;
244 	if (spn->spn_family != AF_PHONET)
245 		return -EAFNOSUPPORT;
246 
247 	lock_sock(sk);
248 
249 	switch (sock->state) {
250 	case SS_UNCONNECTED:
251 		if (sk->sk_state != TCP_CLOSE) {
252 			err = -EISCONN;
253 			goto out;
254 		}
255 		break;
256 	case SS_CONNECTING:
257 		err = -EALREADY;
258 		goto out;
259 	default:
260 		err = -EISCONN;
261 		goto out;
262 	}
263 
264 	pn->dobject = pn_sockaddr_get_object(spn);
265 	pn->resource = pn_sockaddr_get_resource(spn);
266 	sock->state = SS_CONNECTING;
267 
268 	err = sk->sk_prot->connect(sk, addr, len);
269 	if (err) {
270 		sock->state = SS_UNCONNECTED;
271 		pn->dobject = 0;
272 		goto out;
273 	}
274 
275 	while (sk->sk_state == TCP_SYN_SENT) {
276 		DEFINE_WAIT(wait);
277 
278 		if (!timeo) {
279 			err = -EINPROGRESS;
280 			goto out;
281 		}
282 		if (signal_pending(tsk)) {
283 			err = sock_intr_errno(timeo);
284 			goto out;
285 		}
286 
287 		prepare_to_wait_exclusive(sk_sleep(sk), &wait,
288 						TASK_INTERRUPTIBLE);
289 		release_sock(sk);
290 		timeo = schedule_timeout(timeo);
291 		lock_sock(sk);
292 		finish_wait(sk_sleep(sk), &wait);
293 	}
294 
295 	if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED))
296 		err = 0;
297 	else if (sk->sk_state == TCP_CLOSE_WAIT)
298 		err = -ECONNRESET;
299 	else
300 		err = -ECONNREFUSED;
301 	sock->state = err ? SS_UNCONNECTED : SS_CONNECTED;
302 out:
303 	release_sock(sk);
304 	return err;
305 }
306 
307 static int pn_socket_accept(struct socket *sock, struct socket *newsock,
308 				int flags)
309 {
310 	struct sock *sk = sock->sk;
311 	struct sock *newsk;
312 	int err;
313 
314 	if (unlikely(sk->sk_state != TCP_LISTEN))
315 		return -EINVAL;
316 
317 	newsk = sk->sk_prot->accept(sk, flags, &err);
318 	if (!newsk)
319 		return err;
320 
321 	lock_sock(newsk);
322 	sock_graft(newsk, newsock);
323 	newsock->state = SS_CONNECTED;
324 	release_sock(newsk);
325 	return 0;
326 }
327 
328 static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
329 				int *sockaddr_len, int peer)
330 {
331 	struct sock *sk = sock->sk;
332 	struct pn_sock *pn = pn_sk(sk);
333 
334 	memset(addr, 0, sizeof(struct sockaddr_pn));
335 	addr->sa_family = AF_PHONET;
336 	if (!peer) /* Race with bind() here is userland's problem. */
337 		pn_sockaddr_set_object((struct sockaddr_pn *)addr,
338 					pn->sobject);
339 
340 	*sockaddr_len = sizeof(struct sockaddr_pn);
341 	return 0;
342 }
343 
344 static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
345 					poll_table *wait)
346 {
347 	struct sock *sk = sock->sk;
348 	struct pep_sock *pn = pep_sk(sk);
349 	unsigned int mask = 0;
350 
351 	poll_wait(file, sk_sleep(sk), wait);
352 
353 	if (sk->sk_state == TCP_CLOSE)
354 		return POLLERR;
355 	if (!skb_queue_empty(&sk->sk_receive_queue))
356 		mask |= POLLIN | POLLRDNORM;
357 	if (!skb_queue_empty(&pn->ctrlreq_queue))
358 		mask |= POLLPRI;
359 	if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
360 		return POLLHUP;
361 
362 	if (sk->sk_state == TCP_ESTABLISHED &&
363 		atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf &&
364 		atomic_read(&pn->tx_credits))
365 		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
366 
367 	return mask;
368 }
369 
370 static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
371 				unsigned long arg)
372 {
373 	struct sock *sk = sock->sk;
374 	struct pn_sock *pn = pn_sk(sk);
375 
376 	if (cmd == SIOCPNGETOBJECT) {
377 		struct net_device *dev;
378 		u16 handle;
379 		u8 saddr;
380 
381 		if (get_user(handle, (__u16 __user *)arg))
382 			return -EFAULT;
383 
384 		lock_sock(sk);
385 		if (sk->sk_bound_dev_if)
386 			dev = dev_get_by_index(sock_net(sk),
387 						sk->sk_bound_dev_if);
388 		else
389 			dev = phonet_device_get(sock_net(sk));
390 		if (dev && (dev->flags & IFF_UP))
391 			saddr = phonet_address_get(dev, pn_addr(handle));
392 		else
393 			saddr = PN_NO_ADDR;
394 		release_sock(sk);
395 
396 		if (dev)
397 			dev_put(dev);
398 		if (saddr == PN_NO_ADDR)
399 			return -EHOSTUNREACH;
400 
401 		handle = pn_object(saddr, pn_port(pn->sobject));
402 		return put_user(handle, (__u16 __user *)arg);
403 	}
404 
405 	return sk->sk_prot->ioctl(sk, cmd, arg);
406 }
407 
408 static int pn_socket_listen(struct socket *sock, int backlog)
409 {
410 	struct sock *sk = sock->sk;
411 	int err = 0;
412 
413 	if (pn_socket_autobind(sock))
414 		return -ENOBUFS;
415 
416 	lock_sock(sk);
417 	if (sock->state != SS_UNCONNECTED) {
418 		err = -EINVAL;
419 		goto out;
420 	}
421 
422 	if (sk->sk_state != TCP_LISTEN) {
423 		sk->sk_state = TCP_LISTEN;
424 		sk->sk_ack_backlog = 0;
425 	}
426 	sk->sk_max_ack_backlog = backlog;
427 out:
428 	release_sock(sk);
429 	return err;
430 }
431 
432 static int pn_socket_sendmsg(struct socket *sock, struct msghdr *m,
433 			     size_t total_len)
434 {
435 	struct sock *sk = sock->sk;
436 
437 	if (pn_socket_autobind(sock))
438 		return -EAGAIN;
439 
440 	return sk->sk_prot->sendmsg(sk, m, total_len);
441 }
442 
443 const struct proto_ops phonet_dgram_ops = {
444 	.family		= AF_PHONET,
445 	.owner		= THIS_MODULE,
446 	.release	= pn_socket_release,
447 	.bind		= pn_socket_bind,
448 	.connect	= sock_no_connect,
449 	.socketpair	= sock_no_socketpair,
450 	.accept		= sock_no_accept,
451 	.getname	= pn_socket_getname,
452 	.poll		= datagram_poll,
453 	.ioctl		= pn_socket_ioctl,
454 	.listen		= sock_no_listen,
455 	.shutdown	= sock_no_shutdown,
456 	.setsockopt	= sock_no_setsockopt,
457 	.getsockopt	= sock_no_getsockopt,
458 #ifdef CONFIG_COMPAT
459 	.compat_setsockopt = sock_no_setsockopt,
460 	.compat_getsockopt = sock_no_getsockopt,
461 #endif
462 	.sendmsg	= pn_socket_sendmsg,
463 	.recvmsg	= sock_common_recvmsg,
464 	.mmap		= sock_no_mmap,
465 	.sendpage	= sock_no_sendpage,
466 };
467 
468 const struct proto_ops phonet_stream_ops = {
469 	.family		= AF_PHONET,
470 	.owner		= THIS_MODULE,
471 	.release	= pn_socket_release,
472 	.bind		= pn_socket_bind,
473 	.connect	= pn_socket_connect,
474 	.socketpair	= sock_no_socketpair,
475 	.accept		= pn_socket_accept,
476 	.getname	= pn_socket_getname,
477 	.poll		= pn_socket_poll,
478 	.ioctl		= pn_socket_ioctl,
479 	.listen		= pn_socket_listen,
480 	.shutdown	= sock_no_shutdown,
481 	.setsockopt	= sock_common_setsockopt,
482 	.getsockopt	= sock_common_getsockopt,
483 #ifdef CONFIG_COMPAT
484 	.compat_setsockopt = compat_sock_common_setsockopt,
485 	.compat_getsockopt = compat_sock_common_getsockopt,
486 #endif
487 	.sendmsg	= pn_socket_sendmsg,
488 	.recvmsg	= sock_common_recvmsg,
489 	.mmap		= sock_no_mmap,
490 	.sendpage	= sock_no_sendpage,
491 };
492 EXPORT_SYMBOL(phonet_stream_ops);
493 
494 /* allocate port for a socket */
495 int pn_sock_get_port(struct sock *sk, unsigned short sport)
496 {
497 	static int port_cur;
498 	struct net *net = sock_net(sk);
499 	struct pn_sock *pn = pn_sk(sk);
500 	struct sockaddr_pn try_sa;
501 	struct sock *tmpsk;
502 
503 	memset(&try_sa, 0, sizeof(struct sockaddr_pn));
504 	try_sa.spn_family = AF_PHONET;
505 	WARN_ON(!mutex_is_locked(&port_mutex));
506 	if (!sport) {
507 		/* search free port */
508 		int port, pmin, pmax;
509 
510 		phonet_get_local_port_range(&pmin, &pmax);
511 		for (port = pmin; port <= pmax; port++) {
512 			port_cur++;
513 			if (port_cur < pmin || port_cur > pmax)
514 				port_cur = pmin;
515 
516 			pn_sockaddr_set_port(&try_sa, port_cur);
517 			tmpsk = pn_find_sock_by_sa(net, &try_sa);
518 			if (tmpsk == NULL) {
519 				sport = port_cur;
520 				goto found;
521 			} else
522 				sock_put(tmpsk);
523 		}
524 	} else {
525 		/* try to find specific port */
526 		pn_sockaddr_set_port(&try_sa, sport);
527 		tmpsk = pn_find_sock_by_sa(net, &try_sa);
528 		if (tmpsk == NULL)
529 			/* No sock there! We can use that port... */
530 			goto found;
531 		else
532 			sock_put(tmpsk);
533 	}
534 	/* the port must be in use already */
535 	return -EADDRINUSE;
536 
537 found:
538 	pn->sobject = pn_object(pn_addr(pn->sobject), sport);
539 	return 0;
540 }
541 EXPORT_SYMBOL(pn_sock_get_port);
542 
543 #ifdef CONFIG_PROC_FS
544 static struct sock *pn_sock_get_idx(struct seq_file *seq, loff_t pos)
545 {
546 	struct net *net = seq_file_net(seq);
547 	struct hlist_head *hlist = pnsocks.hlist;
548 	struct sock *sknode;
549 	unsigned int h;
550 
551 	for (h = 0; h < PN_HASHSIZE; h++) {
552 		sk_for_each_rcu(sknode, hlist) {
553 			if (!net_eq(net, sock_net(sknode)))
554 				continue;
555 			if (!pos)
556 				return sknode;
557 			pos--;
558 		}
559 		hlist++;
560 	}
561 	return NULL;
562 }
563 
564 static struct sock *pn_sock_get_next(struct seq_file *seq, struct sock *sk)
565 {
566 	struct net *net = seq_file_net(seq);
567 
568 	do
569 		sk = sk_next(sk);
570 	while (sk && !net_eq(net, sock_net(sk)));
571 
572 	return sk;
573 }
574 
575 static void *pn_sock_seq_start(struct seq_file *seq, loff_t *pos)
576 	__acquires(rcu)
577 {
578 	rcu_read_lock();
579 	return *pos ? pn_sock_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
580 }
581 
582 static void *pn_sock_seq_next(struct seq_file *seq, void *v, loff_t *pos)
583 {
584 	struct sock *sk;
585 
586 	if (v == SEQ_START_TOKEN)
587 		sk = pn_sock_get_idx(seq, 0);
588 	else
589 		sk = pn_sock_get_next(seq, v);
590 	(*pos)++;
591 	return sk;
592 }
593 
594 static void pn_sock_seq_stop(struct seq_file *seq, void *v)
595 	__releases(rcu)
596 {
597 	rcu_read_unlock();
598 }
599 
600 static int pn_sock_seq_show(struct seq_file *seq, void *v)
601 {
602 	seq_setwidth(seq, 127);
603 	if (v == SEQ_START_TOKEN)
604 		seq_puts(seq, "pt  loc  rem rs st tx_queue rx_queue "
605 			"  uid inode ref pointer drops");
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",
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 			from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)),
616 			sock_i_ino(sk),
617 			atomic_read(&sk->sk_refcnt), sk,
618 			atomic_read(&sk->sk_drops));
619 	}
620 	seq_pad(seq, '\n');
621 	return 0;
622 }
623 
624 static const struct seq_operations pn_sock_seq_ops = {
625 	.start = pn_sock_seq_start,
626 	.next = pn_sock_seq_next,
627 	.stop = pn_sock_seq_stop,
628 	.show = pn_sock_seq_show,
629 };
630 
631 static int pn_sock_open(struct inode *inode, struct file *file)
632 {
633 	return seq_open_net(inode, file, &pn_sock_seq_ops,
634 				sizeof(struct seq_net_private));
635 }
636 
637 const struct file_operations pn_sock_seq_fops = {
638 	.owner = THIS_MODULE,
639 	.open = pn_sock_open,
640 	.read = seq_read,
641 	.llseek = seq_lseek,
642 	.release = seq_release_net,
643 };
644 #endif
645 
646 static struct  {
647 	struct sock *sk[256];
648 } pnres;
649 
650 /*
651  * Find and hold socket based on resource.
652  */
653 struct sock *pn_find_sock_by_res(struct net *net, u8 res)
654 {
655 	struct sock *sk;
656 
657 	if (!net_eq(net, &init_net))
658 		return NULL;
659 
660 	rcu_read_lock();
661 	sk = rcu_dereference(pnres.sk[res]);
662 	if (sk)
663 		sock_hold(sk);
664 	rcu_read_unlock();
665 	return sk;
666 }
667 
668 static DEFINE_MUTEX(resource_mutex);
669 
670 int pn_sock_bind_res(struct sock *sk, u8 res)
671 {
672 	int ret = -EADDRINUSE;
673 
674 	if (!net_eq(sock_net(sk), &init_net))
675 		return -ENOIOCTLCMD;
676 	if (!capable(CAP_SYS_ADMIN))
677 		return -EPERM;
678 	if (pn_socket_autobind(sk->sk_socket))
679 		return -EAGAIN;
680 
681 	mutex_lock(&resource_mutex);
682 	if (pnres.sk[res] == NULL) {
683 		sock_hold(sk);
684 		rcu_assign_pointer(pnres.sk[res], sk);
685 		ret = 0;
686 	}
687 	mutex_unlock(&resource_mutex);
688 	return ret;
689 }
690 
691 int pn_sock_unbind_res(struct sock *sk, u8 res)
692 {
693 	int ret = -ENOENT;
694 
695 	if (!capable(CAP_SYS_ADMIN))
696 		return -EPERM;
697 
698 	mutex_lock(&resource_mutex);
699 	if (pnres.sk[res] == sk) {
700 		RCU_INIT_POINTER(pnres.sk[res], NULL);
701 		ret = 0;
702 	}
703 	mutex_unlock(&resource_mutex);
704 
705 	if (ret == 0) {
706 		synchronize_rcu();
707 		sock_put(sk);
708 	}
709 	return ret;
710 }
711 
712 void pn_sock_unbind_all_res(struct sock *sk)
713 {
714 	unsigned int res, match = 0;
715 
716 	mutex_lock(&resource_mutex);
717 	for (res = 0; res < 256; res++) {
718 		if (pnres.sk[res] == sk) {
719 			RCU_INIT_POINTER(pnres.sk[res], NULL);
720 			match++;
721 		}
722 	}
723 	mutex_unlock(&resource_mutex);
724 
725 	while (match > 0) {
726 		__sock_put(sk);
727 		match--;
728 	}
729 	/* Caller is responsible for RCU sync before final sock_put() */
730 }
731 
732 #ifdef CONFIG_PROC_FS
733 static struct sock **pn_res_get_idx(struct seq_file *seq, loff_t pos)
734 {
735 	struct net *net = seq_file_net(seq);
736 	unsigned int i;
737 
738 	if (!net_eq(net, &init_net))
739 		return NULL;
740 
741 	for (i = 0; i < 256; i++) {
742 		if (pnres.sk[i] == NULL)
743 			continue;
744 		if (!pos)
745 			return pnres.sk + i;
746 		pos--;
747 	}
748 	return NULL;
749 }
750 
751 static struct sock **pn_res_get_next(struct seq_file *seq, struct sock **sk)
752 {
753 	struct net *net = seq_file_net(seq);
754 	unsigned int i;
755 
756 	BUG_ON(!net_eq(net, &init_net));
757 
758 	for (i = (sk - pnres.sk) + 1; i < 256; i++)
759 		if (pnres.sk[i])
760 			return pnres.sk + i;
761 	return NULL;
762 }
763 
764 static void *pn_res_seq_start(struct seq_file *seq, loff_t *pos)
765 	__acquires(resource_mutex)
766 {
767 	mutex_lock(&resource_mutex);
768 	return *pos ? pn_res_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
769 }
770 
771 static void *pn_res_seq_next(struct seq_file *seq, void *v, loff_t *pos)
772 {
773 	struct sock **sk;
774 
775 	if (v == SEQ_START_TOKEN)
776 		sk = pn_res_get_idx(seq, 0);
777 	else
778 		sk = pn_res_get_next(seq, v);
779 	(*pos)++;
780 	return sk;
781 }
782 
783 static void pn_res_seq_stop(struct seq_file *seq, void *v)
784 	__releases(resource_mutex)
785 {
786 	mutex_unlock(&resource_mutex);
787 }
788 
789 static int pn_res_seq_show(struct seq_file *seq, void *v)
790 {
791 	seq_setwidth(seq, 63);
792 	if (v == SEQ_START_TOKEN)
793 		seq_puts(seq, "rs   uid inode");
794 	else {
795 		struct sock **psk = v;
796 		struct sock *sk = *psk;
797 
798 		seq_printf(seq, "%02X %5u %lu",
799 			   (int) (psk - pnres.sk),
800 			   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)),
801 			   sock_i_ino(sk));
802 	}
803 	seq_pad(seq, '\n');
804 	return 0;
805 }
806 
807 static const struct seq_operations pn_res_seq_ops = {
808 	.start = pn_res_seq_start,
809 	.next = pn_res_seq_next,
810 	.stop = pn_res_seq_stop,
811 	.show = pn_res_seq_show,
812 };
813 
814 static int pn_res_open(struct inode *inode, struct file *file)
815 {
816 	return seq_open_net(inode, file, &pn_res_seq_ops,
817 				sizeof(struct seq_net_private));
818 }
819 
820 const struct file_operations pn_res_seq_fops = {
821 	.owner = THIS_MODULE,
822 	.open = pn_res_open,
823 	.read = seq_read,
824 	.llseek = seq_lseek,
825 	.release = seq_release_net,
826 };
827 #endif
828