1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * File: socket.c
4 *
5 * Phonet sockets
6 *
7 * Copyright (C) 2008 Nokia Corporation.
8 *
9 * Authors: Sakari Ailus <sakari.ailus@nokia.com>
10 * Rémi Denis-Courmont
11 */
12
13 #include <linux/gfp.h>
14 #include <linux/kernel.h>
15 #include <linux/net.h>
16 #include <linux/poll.h>
17 #include <linux/sched/signal.h>
18
19 #include <net/sock.h>
20 #include <net/tcp_states.h>
21
22 #include <linux/phonet.h>
23 #include <linux/export.h>
24 #include <net/phonet/phonet.h>
25 #include <net/phonet/pep.h>
26 #include <net/phonet/pn_dev.h>
27
pn_socket_release(struct socket * sock)28 static int pn_socket_release(struct socket *sock)
29 {
30 struct sock *sk = sock->sk;
31
32 if (sk) {
33 sock->sk = NULL;
34 sk->sk_prot->close(sk, 0);
35 }
36 return 0;
37 }
38
39 #define PN_HASHSIZE 16
40 #define PN_HASHMASK (PN_HASHSIZE-1)
41
42
43 static struct {
44 struct hlist_head hlist[PN_HASHSIZE];
45 struct mutex lock;
46 } pnsocks;
47
pn_sock_init(void)48 void __init pn_sock_init(void)
49 {
50 unsigned int i;
51
52 for (i = 0; i < PN_HASHSIZE; i++)
53 INIT_HLIST_HEAD(pnsocks.hlist + i);
54 mutex_init(&pnsocks.lock);
55 }
56
pn_hash_list(u16 obj)57 static struct hlist_head *pn_hash_list(u16 obj)
58 {
59 return pnsocks.hlist + (obj & PN_HASHMASK);
60 }
61
62 /*
63 * Find address based on socket address, match only certain fields.
64 * Also grab sock if it was found. Remember to sock_put it later.
65 */
pn_find_sock_by_sa(struct net * net,const struct sockaddr_pn * spn)66 struct sock *pn_find_sock_by_sa(struct net *net, const struct sockaddr_pn *spn)
67 {
68 struct sock *sknode;
69 struct sock *rval = NULL;
70 u16 obj = pn_sockaddr_get_object(spn);
71 u8 res = spn->spn_resource;
72 struct hlist_head *hlist = pn_hash_list(obj);
73
74 rcu_read_lock();
75 sk_for_each_rcu(sknode, hlist) {
76 struct pn_sock *pn = pn_sk(sknode);
77 BUG_ON(!pn->sobject); /* unbound socket */
78
79 if (!net_eq(sock_net(sknode), net))
80 continue;
81 if (pn_port(obj)) {
82 /* Look up socket by port */
83 if (pn_port(pn->sobject) != pn_port(obj))
84 continue;
85 } else {
86 /* If port is zero, look up by resource */
87 if (pn->resource != res)
88 continue;
89 }
90 if (pn_addr(pn->sobject) &&
91 pn_addr(pn->sobject) != pn_addr(obj))
92 continue;
93
94 rval = sknode;
95 sock_hold(sknode);
96 break;
97 }
98 rcu_read_unlock();
99
100 return rval;
101 }
102
103 /* Deliver a broadcast packet (only in bottom-half) */
pn_deliver_sock_broadcast(struct net * net,struct sk_buff * skb)104 void pn_deliver_sock_broadcast(struct net *net, struct sk_buff *skb)
105 {
106 struct hlist_head *hlist = pnsocks.hlist;
107 unsigned int h;
108
109 rcu_read_lock();
110 for (h = 0; h < PN_HASHSIZE; h++) {
111 struct sock *sknode;
112
113 sk_for_each(sknode, hlist) {
114 struct sk_buff *clone;
115
116 if (!net_eq(sock_net(sknode), net))
117 continue;
118 if (!sock_flag(sknode, SOCK_BROADCAST))
119 continue;
120
121 clone = skb_clone(skb, GFP_ATOMIC);
122 if (clone) {
123 sock_hold(sknode);
124 sk_receive_skb(sknode, clone, 0);
125 }
126 }
127 hlist++;
128 }
129 rcu_read_unlock();
130 }
131
pn_sock_hash(struct sock * sk)132 int pn_sock_hash(struct sock *sk)
133 {
134 struct hlist_head *hlist = pn_hash_list(pn_sk(sk)->sobject);
135
136 mutex_lock(&pnsocks.lock);
137 sk_add_node_rcu(sk, hlist);
138 mutex_unlock(&pnsocks.lock);
139
140 return 0;
141 }
142 EXPORT_SYMBOL(pn_sock_hash);
143
pn_sock_unhash(struct sock * sk)144 void pn_sock_unhash(struct sock *sk)
145 {
146 mutex_lock(&pnsocks.lock);
147 sk_del_node_init_rcu(sk);
148 mutex_unlock(&pnsocks.lock);
149 pn_sock_unbind_all_res(sk);
150 synchronize_rcu();
151 }
152 EXPORT_SYMBOL(pn_sock_unhash);
153
154 static DEFINE_MUTEX(port_mutex);
155
pn_socket_bind(struct socket * sock,struct sockaddr_unsized * addr,int len)156 static int pn_socket_bind(struct socket *sock, struct sockaddr_unsized *addr, int len)
157 {
158 struct sock *sk = sock->sk;
159 struct pn_sock *pn = pn_sk(sk);
160 struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
161 int err;
162 u16 handle;
163 u8 saddr;
164
165 if (sk->sk_prot->bind)
166 return sk->sk_prot->bind(sk, addr, len);
167
168 if (len < sizeof(struct sockaddr_pn))
169 return -EINVAL;
170 if (spn->spn_family != AF_PHONET)
171 return -EAFNOSUPPORT;
172
173 handle = pn_sockaddr_get_object((struct sockaddr_pn *)addr);
174 saddr = pn_addr(handle);
175 if (saddr && phonet_address_lookup(sock_net(sk), saddr))
176 return -EADDRNOTAVAIL;
177
178 lock_sock(sk);
179 if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
180 err = -EINVAL; /* attempt to rebind */
181 goto out;
182 }
183 WARN_ON(sk_hashed(sk));
184 mutex_lock(&port_mutex);
185 err = sk->sk_prot->get_port(sk, pn_port(handle));
186 if (err)
187 goto out_port;
188
189 /* get_port() sets the port, bind() sets the address if applicable */
190 pn->sobject = pn_object(saddr, pn_port(pn->sobject));
191 pn->resource = spn->spn_resource;
192
193 /* Enable RX on the socket */
194 err = sk->sk_prot->hash(sk);
195 out_port:
196 mutex_unlock(&port_mutex);
197 out:
198 release_sock(sk);
199 return err;
200 }
201
pn_socket_autobind(struct socket * sock)202 static int pn_socket_autobind(struct socket *sock)
203 {
204 struct sockaddr_pn sa;
205 int err;
206
207 memset(&sa, 0, sizeof(sa));
208 sa.spn_family = AF_PHONET;
209 err = pn_socket_bind(sock, (struct sockaddr_unsized *)&sa,
210 sizeof(struct sockaddr_pn));
211 /*
212 * pn_socket_bind() also returns -EINVAL when sk_state != TCP_CLOSE
213 * without a prior bind, so -EINVAL alone is not sufficient to infer
214 * that the socket was already bound. Only treat it as "already
215 * bound" when the port is non-zero; otherwise propagate the error
216 * instead of crashing the kernel.
217 */
218 if (err != -EINVAL || unlikely(!pn_port(pn_sk(sock->sk)->sobject)))
219 return err;
220 return 0; /* socket was already bound */
221 }
222
pn_socket_connect(struct socket * sock,struct sockaddr_unsized * addr,int len,int flags)223 static int pn_socket_connect(struct socket *sock, struct sockaddr_unsized *addr,
224 int len, int flags)
225 {
226 struct sock *sk = sock->sk;
227 struct pn_sock *pn = pn_sk(sk);
228 struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
229 struct task_struct *tsk = current;
230 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
231 int err;
232
233 if (pn_socket_autobind(sock))
234 return -ENOBUFS;
235 if (len < sizeof(struct sockaddr_pn))
236 return -EINVAL;
237 if (spn->spn_family != AF_PHONET)
238 return -EAFNOSUPPORT;
239
240 lock_sock(sk);
241
242 switch (sock->state) {
243 case SS_UNCONNECTED:
244 if (sk->sk_state != TCP_CLOSE) {
245 err = -EISCONN;
246 goto out;
247 }
248 break;
249 case SS_CONNECTING:
250 err = -EALREADY;
251 goto out;
252 default:
253 err = -EISCONN;
254 goto out;
255 }
256
257 pn->dobject = pn_sockaddr_get_object(spn);
258 pn->resource = pn_sockaddr_get_resource(spn);
259 sock->state = SS_CONNECTING;
260
261 err = sk->sk_prot->connect(sk, addr, len);
262 if (err) {
263 sock->state = SS_UNCONNECTED;
264 pn->dobject = 0;
265 goto out;
266 }
267
268 while (sk->sk_state == TCP_SYN_SENT) {
269 DEFINE_WAIT(wait);
270
271 if (!timeo) {
272 err = -EINPROGRESS;
273 goto out;
274 }
275 if (signal_pending(tsk)) {
276 err = sock_intr_errno(timeo);
277 goto out;
278 }
279
280 prepare_to_wait_exclusive(sk_sleep(sk), &wait,
281 TASK_INTERRUPTIBLE);
282 release_sock(sk);
283 timeo = schedule_timeout(timeo);
284 lock_sock(sk);
285 finish_wait(sk_sleep(sk), &wait);
286 }
287
288 if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED))
289 err = 0;
290 else if (sk->sk_state == TCP_CLOSE_WAIT)
291 err = -ECONNRESET;
292 else
293 err = -ECONNREFUSED;
294 sock->state = err ? SS_UNCONNECTED : SS_CONNECTED;
295 out:
296 release_sock(sk);
297 return err;
298 }
299
pn_socket_accept(struct socket * sock,struct socket * newsock,struct proto_accept_arg * arg)300 static int pn_socket_accept(struct socket *sock, struct socket *newsock,
301 struct proto_accept_arg *arg)
302 {
303 struct sock *sk = sock->sk;
304 struct sock *newsk;
305
306 if (unlikely(sk->sk_state != TCP_LISTEN))
307 return -EINVAL;
308
309 newsk = sk->sk_prot->accept(sk, arg);
310 if (!newsk)
311 return arg->err;
312
313 lock_sock(newsk);
314 sock_graft(newsk, newsock);
315 newsock->state = SS_CONNECTED;
316 release_sock(newsk);
317 return 0;
318 }
319
pn_socket_getname(struct socket * sock,struct sockaddr * addr,int peer)320 static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
321 int peer)
322 {
323 struct sock *sk = sock->sk;
324 struct pn_sock *pn = pn_sk(sk);
325
326 memset(addr, 0, sizeof(struct sockaddr_pn));
327 addr->sa_family = AF_PHONET;
328 if (!peer) /* Race with bind() here is userland's problem. */
329 pn_sockaddr_set_object((struct sockaddr_pn *)addr,
330 pn->sobject);
331
332 return sizeof(struct sockaddr_pn);
333 }
334
pn_socket_poll(struct file * file,struct socket * sock,poll_table * wait)335 static __poll_t pn_socket_poll(struct file *file, struct socket *sock,
336 poll_table *wait)
337 {
338 struct sock *sk = sock->sk;
339 struct pep_sock *pn = pep_sk(sk);
340 __poll_t mask = 0;
341
342 poll_wait(file, sk_sleep(sk), wait);
343
344 if (sk->sk_state == TCP_CLOSE)
345 return EPOLLERR;
346 if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
347 mask |= EPOLLIN | EPOLLRDNORM;
348 if (!skb_queue_empty_lockless(&pn->ctrlreq_queue))
349 mask |= EPOLLPRI;
350 if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
351 return EPOLLHUP;
352
353 if (sk->sk_state == TCP_ESTABLISHED &&
354 refcount_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf &&
355 atomic_read(&pn->tx_credits))
356 mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
357
358 return mask;
359 }
360
pn_socket_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)361 static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
362 unsigned long arg)
363 {
364 struct sock *sk = sock->sk;
365 struct pn_sock *pn = pn_sk(sk);
366
367 if (cmd == SIOCPNGETOBJECT) {
368 struct net_device *dev;
369 u16 handle;
370 u8 saddr;
371
372 if (get_user(handle, (__u16 __user *)arg))
373 return -EFAULT;
374
375 lock_sock(sk);
376 if (sk->sk_bound_dev_if)
377 dev = dev_get_by_index(sock_net(sk),
378 sk->sk_bound_dev_if);
379 else
380 dev = phonet_device_get(sock_net(sk));
381 if (dev && (dev->flags & IFF_UP))
382 saddr = phonet_address_get(dev, pn_addr(handle));
383 else
384 saddr = PN_NO_ADDR;
385 release_sock(sk);
386
387 dev_put(dev);
388 if (saddr == PN_NO_ADDR)
389 return -EHOSTUNREACH;
390
391 handle = pn_object(saddr, pn_port(pn->sobject));
392 return put_user(handle, (__u16 __user *)arg);
393 }
394
395 return sk_ioctl(sk, cmd, (void __user *)arg);
396 }
397
pn_socket_listen(struct socket * sock,int backlog)398 static int pn_socket_listen(struct socket *sock, int backlog)
399 {
400 struct sock *sk = sock->sk;
401 int err = 0;
402
403 if (pn_socket_autobind(sock))
404 return -ENOBUFS;
405
406 lock_sock(sk);
407 if (sock->state != SS_UNCONNECTED) {
408 err = -EINVAL;
409 goto out;
410 }
411
412 if (sk->sk_state != TCP_LISTEN) {
413 sk->sk_state = TCP_LISTEN;
414 sk->sk_ack_backlog = 0;
415 }
416 sk->sk_max_ack_backlog = backlog;
417 out:
418 release_sock(sk);
419 return err;
420 }
421
pn_socket_sendmsg(struct socket * sock,struct msghdr * m,size_t total_len)422 static int pn_socket_sendmsg(struct socket *sock, struct msghdr *m,
423 size_t total_len)
424 {
425 struct sock *sk = sock->sk;
426
427 if (pn_socket_autobind(sock))
428 return -EAGAIN;
429
430 return sk->sk_prot->sendmsg(sk, m, total_len);
431 }
432
433 const struct proto_ops phonet_dgram_ops = {
434 .family = AF_PHONET,
435 .owner = THIS_MODULE,
436 .release = pn_socket_release,
437 .bind = pn_socket_bind,
438 .connect = sock_no_connect,
439 .socketpair = sock_no_socketpair,
440 .accept = sock_no_accept,
441 .getname = pn_socket_getname,
442 .poll = datagram_poll,
443 .ioctl = pn_socket_ioctl,
444 .listen = sock_no_listen,
445 .shutdown = sock_no_shutdown,
446 .sendmsg = pn_socket_sendmsg,
447 .recvmsg = sock_common_recvmsg,
448 .mmap = sock_no_mmap,
449 };
450
451 const struct proto_ops phonet_stream_ops = {
452 .family = AF_PHONET,
453 .owner = THIS_MODULE,
454 .release = pn_socket_release,
455 .bind = pn_socket_bind,
456 .connect = pn_socket_connect,
457 .socketpair = sock_no_socketpair,
458 .accept = pn_socket_accept,
459 .getname = pn_socket_getname,
460 .poll = pn_socket_poll,
461 .ioctl = pn_socket_ioctl,
462 .listen = pn_socket_listen,
463 .shutdown = sock_no_shutdown,
464 .setsockopt = sock_common_setsockopt,
465 .getsockopt = sock_common_getsockopt,
466 .sendmsg = pn_socket_sendmsg,
467 .recvmsg = sock_common_recvmsg,
468 .mmap = sock_no_mmap,
469 };
470 EXPORT_SYMBOL(phonet_stream_ops);
471
472 /* allocate port for a socket */
pn_sock_get_port(struct sock * sk,unsigned short sport)473 int pn_sock_get_port(struct sock *sk, unsigned short sport)
474 {
475 static int port_cur;
476 struct net *net = sock_net(sk);
477 struct pn_sock *pn = pn_sk(sk);
478 struct sockaddr_pn try_sa;
479 struct sock *tmpsk;
480
481 memset(&try_sa, 0, sizeof(struct sockaddr_pn));
482 try_sa.spn_family = AF_PHONET;
483 WARN_ON(!mutex_is_locked(&port_mutex));
484 if (!sport) {
485 /* search free port */
486 int port, pmin, pmax;
487
488 phonet_get_local_port_range(&pmin, &pmax);
489 for (port = pmin; port <= pmax; port++) {
490 port_cur++;
491 if (port_cur < pmin || port_cur > pmax)
492 port_cur = pmin;
493
494 pn_sockaddr_set_port(&try_sa, port_cur);
495 tmpsk = pn_find_sock_by_sa(net, &try_sa);
496 if (tmpsk == NULL) {
497 sport = port_cur;
498 goto found;
499 } else
500 sock_put(tmpsk);
501 }
502 } else {
503 /* try to find specific port */
504 pn_sockaddr_set_port(&try_sa, sport);
505 tmpsk = pn_find_sock_by_sa(net, &try_sa);
506 if (tmpsk == NULL)
507 /* No sock there! We can use that port... */
508 goto found;
509 else
510 sock_put(tmpsk);
511 }
512 /* the port must be in use already */
513 return -EADDRINUSE;
514
515 found:
516 pn->sobject = pn_object(pn_addr(pn->sobject), sport);
517 return 0;
518 }
519 EXPORT_SYMBOL(pn_sock_get_port);
520
521 #ifdef CONFIG_PROC_FS
pn_sock_get_idx(struct seq_file * seq,loff_t pos)522 static struct sock *pn_sock_get_idx(struct seq_file *seq, loff_t pos)
523 {
524 struct net *net = seq_file_net(seq);
525 struct hlist_head *hlist = pnsocks.hlist;
526 struct sock *sknode;
527 unsigned int h;
528
529 for (h = 0; h < PN_HASHSIZE; h++) {
530 sk_for_each_rcu(sknode, hlist) {
531 if (!net_eq(net, sock_net(sknode)))
532 continue;
533 if (!pos)
534 return sknode;
535 pos--;
536 }
537 hlist++;
538 }
539 return NULL;
540 }
541
pn_sock_get_next(struct seq_file * seq,struct sock * sk)542 static struct sock *pn_sock_get_next(struct seq_file *seq, struct sock *sk)
543 {
544 struct net *net = seq_file_net(seq);
545
546 do
547 sk = sk_next(sk);
548 while (sk && !net_eq(net, sock_net(sk)));
549
550 return sk;
551 }
552
pn_sock_seq_start(struct seq_file * seq,loff_t * pos)553 static void *pn_sock_seq_start(struct seq_file *seq, loff_t *pos)
554 __acquires(rcu)
555 {
556 rcu_read_lock();
557 return *pos ? pn_sock_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
558 }
559
pn_sock_seq_next(struct seq_file * seq,void * v,loff_t * pos)560 static void *pn_sock_seq_next(struct seq_file *seq, void *v, loff_t *pos)
561 {
562 struct sock *sk;
563
564 if (v == SEQ_START_TOKEN)
565 sk = pn_sock_get_idx(seq, 0);
566 else
567 sk = pn_sock_get_next(seq, v);
568 (*pos)++;
569 return sk;
570 }
571
pn_sock_seq_stop(struct seq_file * seq,void * v)572 static void pn_sock_seq_stop(struct seq_file *seq, void *v)
573 __releases(rcu)
574 {
575 rcu_read_unlock();
576 }
577
pn_sock_seq_show(struct seq_file * seq,void * v)578 static int pn_sock_seq_show(struct seq_file *seq, void *v)
579 {
580 seq_setwidth(seq, 127);
581 if (v == SEQ_START_TOKEN)
582 seq_puts(seq, "pt loc rem rs st tx_queue rx_queue "
583 " uid inode ref pointer drops");
584 else {
585 struct sock *sk = v;
586 struct pn_sock *pn = pn_sk(sk);
587
588 seq_printf(seq, "%2d %04X:%04X:%02X %02X %08X:%08X %5d %llu "
589 "%d %pK %u",
590 sk->sk_protocol, pn->sobject, pn->dobject,
591 pn->resource, sk->sk_state,
592 sk_wmem_alloc_get(sk), sk_rmem_alloc_get(sk),
593 from_kuid_munged(seq_user_ns(seq), sk_uid(sk)),
594 sock_i_ino(sk),
595 refcount_read(&sk->sk_refcnt), sk,
596 sk_drops_read(sk));
597 }
598 seq_pad(seq, '\n');
599 return 0;
600 }
601
602 const struct seq_operations pn_sock_seq_ops = {
603 .start = pn_sock_seq_start,
604 .next = pn_sock_seq_next,
605 .stop = pn_sock_seq_stop,
606 .show = pn_sock_seq_show,
607 };
608 #endif
609
610 static struct {
611 struct sock __rcu *sk[256];
612 } pnres;
613
614 /*
615 * Find and hold socket based on resource.
616 */
pn_find_sock_by_res(struct net * net,u8 res)617 struct sock *pn_find_sock_by_res(struct net *net, u8 res)
618 {
619 struct sock *sk;
620
621 if (!net_eq(net, &init_net))
622 return NULL;
623
624 rcu_read_lock();
625 sk = rcu_dereference(pnres.sk[res]);
626 if (sk)
627 sock_hold(sk);
628 rcu_read_unlock();
629 return sk;
630 }
631
632 static DEFINE_MUTEX(resource_mutex);
633
pn_sock_bind_res(struct sock * sk,u8 res)634 int pn_sock_bind_res(struct sock *sk, u8 res)
635 {
636 int ret = -EADDRINUSE;
637
638 if (!net_eq(sock_net(sk), &init_net))
639 return -ENOIOCTLCMD;
640 if (!capable(CAP_SYS_ADMIN))
641 return -EPERM;
642 if (pn_socket_autobind(sk->sk_socket))
643 return -EAGAIN;
644
645 mutex_lock(&resource_mutex);
646 if (pnres.sk[res] == NULL) {
647 sock_hold(sk);
648 rcu_assign_pointer(pnres.sk[res], sk);
649 ret = 0;
650 }
651 mutex_unlock(&resource_mutex);
652 return ret;
653 }
654
pn_sock_unbind_res(struct sock * sk,u8 res)655 int pn_sock_unbind_res(struct sock *sk, u8 res)
656 {
657 int ret = -ENOENT;
658
659 if (!capable(CAP_SYS_ADMIN))
660 return -EPERM;
661
662 mutex_lock(&resource_mutex);
663 if (rcu_access_pointer(pnres.sk[res]) == sk) {
664 RCU_INIT_POINTER(pnres.sk[res], NULL);
665 ret = 0;
666 }
667 mutex_unlock(&resource_mutex);
668
669 if (ret == 0) {
670 synchronize_rcu();
671 sock_put(sk);
672 }
673 return ret;
674 }
675
pn_sock_unbind_all_res(struct sock * sk)676 void pn_sock_unbind_all_res(struct sock *sk)
677 {
678 unsigned int res, match = 0;
679
680 mutex_lock(&resource_mutex);
681 for (res = 0; res < 256; res++) {
682 if (rcu_access_pointer(pnres.sk[res]) == sk) {
683 RCU_INIT_POINTER(pnres.sk[res], NULL);
684 match++;
685 }
686 }
687 mutex_unlock(&resource_mutex);
688
689 while (match > 0) {
690 __sock_put(sk);
691 match--;
692 }
693 /* Caller is responsible for RCU sync before final sock_put() */
694 }
695
696 #ifdef CONFIG_PROC_FS
pn_res_get_idx(struct seq_file * seq,loff_t pos)697 static struct sock __rcu **pn_res_get_idx(struct seq_file *seq, loff_t pos)
698 {
699 struct net *net = seq_file_net(seq);
700 unsigned int i;
701
702 if (!net_eq(net, &init_net))
703 return NULL;
704
705 for (i = 0; i < 256; i++) {
706 if (rcu_access_pointer(pnres.sk[i]) == NULL)
707 continue;
708 if (!pos)
709 return pnres.sk + i;
710 pos--;
711 }
712 return NULL;
713 }
714
pn_res_get_next(struct seq_file * seq,struct sock __rcu ** sk)715 static struct sock __rcu **pn_res_get_next(struct seq_file *seq, struct sock __rcu **sk)
716 {
717 struct net *net = seq_file_net(seq);
718 unsigned int i;
719
720 BUG_ON(!net_eq(net, &init_net));
721
722 for (i = (sk - pnres.sk) + 1; i < 256; i++)
723 if (pnres.sk[i])
724 return pnres.sk + i;
725 return NULL;
726 }
727
pn_res_seq_start(struct seq_file * seq,loff_t * pos)728 static void *pn_res_seq_start(struct seq_file *seq, loff_t *pos)
729 __acquires(resource_mutex)
730 {
731 mutex_lock(&resource_mutex);
732 return *pos ? pn_res_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
733 }
734
pn_res_seq_next(struct seq_file * seq,void * v,loff_t * pos)735 static void *pn_res_seq_next(struct seq_file *seq, void *v, loff_t *pos)
736 {
737 struct sock __rcu **sk;
738
739 if (v == SEQ_START_TOKEN)
740 sk = pn_res_get_idx(seq, 0);
741 else
742 sk = pn_res_get_next(seq, v);
743 (*pos)++;
744 return sk;
745 }
746
pn_res_seq_stop(struct seq_file * seq,void * v)747 static void pn_res_seq_stop(struct seq_file *seq, void *v)
748 __releases(resource_mutex)
749 {
750 mutex_unlock(&resource_mutex);
751 }
752
pn_res_seq_show(struct seq_file * seq,void * v)753 static int pn_res_seq_show(struct seq_file *seq, void *v)
754 {
755 seq_setwidth(seq, 63);
756 if (v == SEQ_START_TOKEN) {
757 seq_puts(seq, "rs uid inode");
758 } else {
759 struct sock __rcu **psk = v;
760 struct sock *sk = rcu_dereference_protected(*psk,
761 lockdep_is_held(&resource_mutex));
762
763 seq_printf(seq, "%02X %5u %llu",
764 (int) (psk - pnres.sk),
765 from_kuid_munged(seq_user_ns(seq), sk_uid(sk)),
766 sock_i_ino(sk));
767 }
768 seq_pad(seq, '\n');
769 return 0;
770 }
771
772 const struct seq_operations pn_res_seq_ops = {
773 .start = pn_res_seq_start,
774 .next = pn_res_seq_next,
775 .stop = pn_res_seq_stop,
776 .show = pn_res_seq_show,
777 };
778 #endif
779