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TOMOYO Linux Cross Reference
Linux/net/phonet/socket.c

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  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  *          RĂ©mi 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 

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