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Merge branch 'for-3.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
[deliverable/linux.git] / net / netlink / af_netlink.c
1 /*
2 * NETLINK Kernel-user communication protocol.
3 *
4 * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk>
5 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith
13 * added netlink_proto_exit
14 * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br>
15 * use nlk_sk, as sk->protinfo is on a diet 8)
16 * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org>
17 * - inc module use count of module that owns
18 * the kernel socket in case userspace opens
19 * socket of same protocol
20 * - remove all module support, since netlink is
21 * mandatory if CONFIG_NET=y these days
22 */
23
24 #include <linux/module.h>
25
26 #include <linux/capability.h>
27 #include <linux/kernel.h>
28 #include <linux/init.h>
29 #include <linux/signal.h>
30 #include <linux/sched.h>
31 #include <linux/errno.h>
32 #include <linux/string.h>
33 #include <linux/stat.h>
34 #include <linux/socket.h>
35 #include <linux/un.h>
36 #include <linux/fcntl.h>
37 #include <linux/termios.h>
38 #include <linux/sockios.h>
39 #include <linux/net.h>
40 #include <linux/fs.h>
41 #include <linux/slab.h>
42 #include <asm/uaccess.h>
43 #include <linux/skbuff.h>
44 #include <linux/netdevice.h>
45 #include <linux/rtnetlink.h>
46 #include <linux/proc_fs.h>
47 #include <linux/seq_file.h>
48 #include <linux/notifier.h>
49 #include <linux/security.h>
50 #include <linux/jhash.h>
51 #include <linux/jiffies.h>
52 #include <linux/random.h>
53 #include <linux/bitops.h>
54 #include <linux/mm.h>
55 #include <linux/types.h>
56 #include <linux/audit.h>
57 #include <linux/mutex.h>
58
59 #include <net/net_namespace.h>
60 #include <net/sock.h>
61 #include <net/scm.h>
62 #include <net/netlink.h>
63
64 #define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8)
65 #define NLGRPLONGS(x) (NLGRPSZ(x)/sizeof(unsigned long))
66
67 struct netlink_sock {
68 /* struct sock has to be the first member of netlink_sock */
69 struct sock sk;
70 u32 pid;
71 u32 dst_pid;
72 u32 dst_group;
73 u32 flags;
74 u32 subscriptions;
75 u32 ngroups;
76 unsigned long *groups;
77 unsigned long state;
78 wait_queue_head_t wait;
79 struct netlink_callback *cb;
80 struct mutex *cb_mutex;
81 struct mutex cb_def_mutex;
82 void (*netlink_rcv)(struct sk_buff *skb);
83 void (*netlink_bind)(int group);
84 struct module *module;
85 };
86
87 struct listeners {
88 struct rcu_head rcu;
89 unsigned long masks[0];
90 };
91
92 #define NETLINK_KERNEL_SOCKET 0x1
93 #define NETLINK_RECV_PKTINFO 0x2
94 #define NETLINK_BROADCAST_SEND_ERROR 0x4
95 #define NETLINK_RECV_NO_ENOBUFS 0x8
96
97 static inline struct netlink_sock *nlk_sk(struct sock *sk)
98 {
99 return container_of(sk, struct netlink_sock, sk);
100 }
101
102 static inline int netlink_is_kernel(struct sock *sk)
103 {
104 return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET;
105 }
106
107 struct nl_pid_hash {
108 struct hlist_head *table;
109 unsigned long rehash_time;
110
111 unsigned int mask;
112 unsigned int shift;
113
114 unsigned int entries;
115 unsigned int max_shift;
116
117 u32 rnd;
118 };
119
120 struct netlink_table {
121 struct nl_pid_hash hash;
122 struct hlist_head mc_list;
123 struct listeners __rcu *listeners;
124 unsigned int nl_nonroot;
125 unsigned int groups;
126 struct mutex *cb_mutex;
127 struct module *module;
128 void (*bind)(int group);
129 int registered;
130 };
131
132 static struct netlink_table *nl_table;
133
134 static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
135
136 static int netlink_dump(struct sock *sk);
137
138 static DEFINE_RWLOCK(nl_table_lock);
139 static atomic_t nl_table_users = ATOMIC_INIT(0);
140
141 static ATOMIC_NOTIFIER_HEAD(netlink_chain);
142
143 static inline u32 netlink_group_mask(u32 group)
144 {
145 return group ? 1 << (group - 1) : 0;
146 }
147
148 static inline struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid)
149 {
150 return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask];
151 }
152
153 static void netlink_destroy_callback(struct netlink_callback *cb)
154 {
155 kfree_skb(cb->skb);
156 kfree(cb);
157 }
158
159 static void netlink_consume_callback(struct netlink_callback *cb)
160 {
161 consume_skb(cb->skb);
162 kfree(cb);
163 }
164
165 static void netlink_sock_destruct(struct sock *sk)
166 {
167 struct netlink_sock *nlk = nlk_sk(sk);
168
169 if (nlk->cb) {
170 if (nlk->cb->done)
171 nlk->cb->done(nlk->cb);
172 netlink_destroy_callback(nlk->cb);
173 }
174
175 skb_queue_purge(&sk->sk_receive_queue);
176
177 if (!sock_flag(sk, SOCK_DEAD)) {
178 printk(KERN_ERR "Freeing alive netlink socket %p\n", sk);
179 return;
180 }
181
182 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
183 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
184 WARN_ON(nlk_sk(sk)->groups);
185 }
186
187 /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on
188 * SMP. Look, when several writers sleep and reader wakes them up, all but one
189 * immediately hit write lock and grab all the cpus. Exclusive sleep solves
190 * this, _but_ remember, it adds useless work on UP machines.
191 */
192
193 void netlink_table_grab(void)
194 __acquires(nl_table_lock)
195 {
196 might_sleep();
197
198 write_lock_irq(&nl_table_lock);
199
200 if (atomic_read(&nl_table_users)) {
201 DECLARE_WAITQUEUE(wait, current);
202
203 add_wait_queue_exclusive(&nl_table_wait, &wait);
204 for (;;) {
205 set_current_state(TASK_UNINTERRUPTIBLE);
206 if (atomic_read(&nl_table_users) == 0)
207 break;
208 write_unlock_irq(&nl_table_lock);
209 schedule();
210 write_lock_irq(&nl_table_lock);
211 }
212
213 __set_current_state(TASK_RUNNING);
214 remove_wait_queue(&nl_table_wait, &wait);
215 }
216 }
217
218 void netlink_table_ungrab(void)
219 __releases(nl_table_lock)
220 {
221 write_unlock_irq(&nl_table_lock);
222 wake_up(&nl_table_wait);
223 }
224
225 static inline void
226 netlink_lock_table(void)
227 {
228 /* read_lock() synchronizes us to netlink_table_grab */
229
230 read_lock(&nl_table_lock);
231 atomic_inc(&nl_table_users);
232 read_unlock(&nl_table_lock);
233 }
234
235 static inline void
236 netlink_unlock_table(void)
237 {
238 if (atomic_dec_and_test(&nl_table_users))
239 wake_up(&nl_table_wait);
240 }
241
242 static struct sock *netlink_lookup(struct net *net, int protocol, u32 pid)
243 {
244 struct nl_pid_hash *hash = &nl_table[protocol].hash;
245 struct hlist_head *head;
246 struct sock *sk;
247 struct hlist_node *node;
248
249 read_lock(&nl_table_lock);
250 head = nl_pid_hashfn(hash, pid);
251 sk_for_each(sk, node, head) {
252 if (net_eq(sock_net(sk), net) && (nlk_sk(sk)->pid == pid)) {
253 sock_hold(sk);
254 goto found;
255 }
256 }
257 sk = NULL;
258 found:
259 read_unlock(&nl_table_lock);
260 return sk;
261 }
262
263 static struct hlist_head *nl_pid_hash_zalloc(size_t size)
264 {
265 if (size <= PAGE_SIZE)
266 return kzalloc(size, GFP_ATOMIC);
267 else
268 return (struct hlist_head *)
269 __get_free_pages(GFP_ATOMIC | __GFP_ZERO,
270 get_order(size));
271 }
272
273 static void nl_pid_hash_free(struct hlist_head *table, size_t size)
274 {
275 if (size <= PAGE_SIZE)
276 kfree(table);
277 else
278 free_pages((unsigned long)table, get_order(size));
279 }
280
281 static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow)
282 {
283 unsigned int omask, mask, shift;
284 size_t osize, size;
285 struct hlist_head *otable, *table;
286 int i;
287
288 omask = mask = hash->mask;
289 osize = size = (mask + 1) * sizeof(*table);
290 shift = hash->shift;
291
292 if (grow) {
293 if (++shift > hash->max_shift)
294 return 0;
295 mask = mask * 2 + 1;
296 size *= 2;
297 }
298
299 table = nl_pid_hash_zalloc(size);
300 if (!table)
301 return 0;
302
303 otable = hash->table;
304 hash->table = table;
305 hash->mask = mask;
306 hash->shift = shift;
307 get_random_bytes(&hash->rnd, sizeof(hash->rnd));
308
309 for (i = 0; i <= omask; i++) {
310 struct sock *sk;
311 struct hlist_node *node, *tmp;
312
313 sk_for_each_safe(sk, node, tmp, &otable[i])
314 __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid));
315 }
316
317 nl_pid_hash_free(otable, osize);
318 hash->rehash_time = jiffies + 10 * 60 * HZ;
319 return 1;
320 }
321
322 static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len)
323 {
324 int avg = hash->entries >> hash->shift;
325
326 if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1))
327 return 1;
328
329 if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) {
330 nl_pid_hash_rehash(hash, 0);
331 return 1;
332 }
333
334 return 0;
335 }
336
337 static const struct proto_ops netlink_ops;
338
339 static void
340 netlink_update_listeners(struct sock *sk)
341 {
342 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
343 struct hlist_node *node;
344 unsigned long mask;
345 unsigned int i;
346
347 for (i = 0; i < NLGRPLONGS(tbl->groups); i++) {
348 mask = 0;
349 sk_for_each_bound(sk, node, &tbl->mc_list) {
350 if (i < NLGRPLONGS(nlk_sk(sk)->ngroups))
351 mask |= nlk_sk(sk)->groups[i];
352 }
353 tbl->listeners->masks[i] = mask;
354 }
355 /* this function is only called with the netlink table "grabbed", which
356 * makes sure updates are visible before bind or setsockopt return. */
357 }
358
359 static int netlink_insert(struct sock *sk, struct net *net, u32 pid)
360 {
361 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
362 struct hlist_head *head;
363 int err = -EADDRINUSE;
364 struct sock *osk;
365 struct hlist_node *node;
366 int len;
367
368 netlink_table_grab();
369 head = nl_pid_hashfn(hash, pid);
370 len = 0;
371 sk_for_each(osk, node, head) {
372 if (net_eq(sock_net(osk), net) && (nlk_sk(osk)->pid == pid))
373 break;
374 len++;
375 }
376 if (node)
377 goto err;
378
379 err = -EBUSY;
380 if (nlk_sk(sk)->pid)
381 goto err;
382
383 err = -ENOMEM;
384 if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX))
385 goto err;
386
387 if (len && nl_pid_hash_dilute(hash, len))
388 head = nl_pid_hashfn(hash, pid);
389 hash->entries++;
390 nlk_sk(sk)->pid = pid;
391 sk_add_node(sk, head);
392 err = 0;
393
394 err:
395 netlink_table_ungrab();
396 return err;
397 }
398
399 static void netlink_remove(struct sock *sk)
400 {
401 netlink_table_grab();
402 if (sk_del_node_init(sk))
403 nl_table[sk->sk_protocol].hash.entries--;
404 if (nlk_sk(sk)->subscriptions)
405 __sk_del_bind_node(sk);
406 netlink_table_ungrab();
407 }
408
409 static struct proto netlink_proto = {
410 .name = "NETLINK",
411 .owner = THIS_MODULE,
412 .obj_size = sizeof(struct netlink_sock),
413 };
414
415 static int __netlink_create(struct net *net, struct socket *sock,
416 struct mutex *cb_mutex, int protocol)
417 {
418 struct sock *sk;
419 struct netlink_sock *nlk;
420
421 sock->ops = &netlink_ops;
422
423 sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto);
424 if (!sk)
425 return -ENOMEM;
426
427 sock_init_data(sock, sk);
428
429 nlk = nlk_sk(sk);
430 if (cb_mutex) {
431 nlk->cb_mutex = cb_mutex;
432 } else {
433 nlk->cb_mutex = &nlk->cb_def_mutex;
434 mutex_init(nlk->cb_mutex);
435 }
436 init_waitqueue_head(&nlk->wait);
437
438 sk->sk_destruct = netlink_sock_destruct;
439 sk->sk_protocol = protocol;
440 return 0;
441 }
442
443 static int netlink_create(struct net *net, struct socket *sock, int protocol,
444 int kern)
445 {
446 struct module *module = NULL;
447 struct mutex *cb_mutex;
448 struct netlink_sock *nlk;
449 void (*bind)(int group);
450 int err = 0;
451
452 sock->state = SS_UNCONNECTED;
453
454 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
455 return -ESOCKTNOSUPPORT;
456
457 if (protocol < 0 || protocol >= MAX_LINKS)
458 return -EPROTONOSUPPORT;
459
460 netlink_lock_table();
461 #ifdef CONFIG_MODULES
462 if (!nl_table[protocol].registered) {
463 netlink_unlock_table();
464 request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
465 netlink_lock_table();
466 }
467 #endif
468 if (nl_table[protocol].registered &&
469 try_module_get(nl_table[protocol].module))
470 module = nl_table[protocol].module;
471 else
472 err = -EPROTONOSUPPORT;
473 cb_mutex = nl_table[protocol].cb_mutex;
474 bind = nl_table[protocol].bind;
475 netlink_unlock_table();
476
477 if (err < 0)
478 goto out;
479
480 err = __netlink_create(net, sock, cb_mutex, protocol);
481 if (err < 0)
482 goto out_module;
483
484 local_bh_disable();
485 sock_prot_inuse_add(net, &netlink_proto, 1);
486 local_bh_enable();
487
488 nlk = nlk_sk(sock->sk);
489 nlk->module = module;
490 nlk->netlink_bind = bind;
491 out:
492 return err;
493
494 out_module:
495 module_put(module);
496 goto out;
497 }
498
499 static int netlink_release(struct socket *sock)
500 {
501 struct sock *sk = sock->sk;
502 struct netlink_sock *nlk;
503
504 if (!sk)
505 return 0;
506
507 netlink_remove(sk);
508 sock_orphan(sk);
509 nlk = nlk_sk(sk);
510
511 /*
512 * OK. Socket is unlinked, any packets that arrive now
513 * will be purged.
514 */
515
516 sock->sk = NULL;
517 wake_up_interruptible_all(&nlk->wait);
518
519 skb_queue_purge(&sk->sk_write_queue);
520
521 if (nlk->pid) {
522 struct netlink_notify n = {
523 .net = sock_net(sk),
524 .protocol = sk->sk_protocol,
525 .pid = nlk->pid,
526 };
527 atomic_notifier_call_chain(&netlink_chain,
528 NETLINK_URELEASE, &n);
529 }
530
531 module_put(nlk->module);
532
533 netlink_table_grab();
534 if (netlink_is_kernel(sk)) {
535 BUG_ON(nl_table[sk->sk_protocol].registered == 0);
536 if (--nl_table[sk->sk_protocol].registered == 0) {
537 kfree(nl_table[sk->sk_protocol].listeners);
538 nl_table[sk->sk_protocol].module = NULL;
539 nl_table[sk->sk_protocol].registered = 0;
540 }
541 } else if (nlk->subscriptions) {
542 netlink_update_listeners(sk);
543 }
544 netlink_table_ungrab();
545
546 kfree(nlk->groups);
547 nlk->groups = NULL;
548
549 local_bh_disable();
550 sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1);
551 local_bh_enable();
552 sock_put(sk);
553 return 0;
554 }
555
556 static int netlink_autobind(struct socket *sock)
557 {
558 struct sock *sk = sock->sk;
559 struct net *net = sock_net(sk);
560 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
561 struct hlist_head *head;
562 struct sock *osk;
563 struct hlist_node *node;
564 s32 pid = task_tgid_vnr(current);
565 int err;
566 static s32 rover = -4097;
567
568 retry:
569 cond_resched();
570 netlink_table_grab();
571 head = nl_pid_hashfn(hash, pid);
572 sk_for_each(osk, node, head) {
573 if (!net_eq(sock_net(osk), net))
574 continue;
575 if (nlk_sk(osk)->pid == pid) {
576 /* Bind collision, search negative pid values. */
577 pid = rover--;
578 if (rover > -4097)
579 rover = -4097;
580 netlink_table_ungrab();
581 goto retry;
582 }
583 }
584 netlink_table_ungrab();
585
586 err = netlink_insert(sk, net, pid);
587 if (err == -EADDRINUSE)
588 goto retry;
589
590 /* If 2 threads race to autobind, that is fine. */
591 if (err == -EBUSY)
592 err = 0;
593
594 return err;
595 }
596
597 static inline int netlink_capable(const struct socket *sock, unsigned int flag)
598 {
599 return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) ||
600 capable(CAP_NET_ADMIN);
601 }
602
603 static void
604 netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions)
605 {
606 struct netlink_sock *nlk = nlk_sk(sk);
607
608 if (nlk->subscriptions && !subscriptions)
609 __sk_del_bind_node(sk);
610 else if (!nlk->subscriptions && subscriptions)
611 sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
612 nlk->subscriptions = subscriptions;
613 }
614
615 static int netlink_realloc_groups(struct sock *sk)
616 {
617 struct netlink_sock *nlk = nlk_sk(sk);
618 unsigned int groups;
619 unsigned long *new_groups;
620 int err = 0;
621
622 netlink_table_grab();
623
624 groups = nl_table[sk->sk_protocol].groups;
625 if (!nl_table[sk->sk_protocol].registered) {
626 err = -ENOENT;
627 goto out_unlock;
628 }
629
630 if (nlk->ngroups >= groups)
631 goto out_unlock;
632
633 new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC);
634 if (new_groups == NULL) {
635 err = -ENOMEM;
636 goto out_unlock;
637 }
638 memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0,
639 NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups));
640
641 nlk->groups = new_groups;
642 nlk->ngroups = groups;
643 out_unlock:
644 netlink_table_ungrab();
645 return err;
646 }
647
648 static int netlink_bind(struct socket *sock, struct sockaddr *addr,
649 int addr_len)
650 {
651 struct sock *sk = sock->sk;
652 struct net *net = sock_net(sk);
653 struct netlink_sock *nlk = nlk_sk(sk);
654 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
655 int err;
656
657 if (nladdr->nl_family != AF_NETLINK)
658 return -EINVAL;
659
660 /* Only superuser is allowed to listen multicasts */
661 if (nladdr->nl_groups) {
662 if (!netlink_capable(sock, NL_NONROOT_RECV))
663 return -EPERM;
664 err = netlink_realloc_groups(sk);
665 if (err)
666 return err;
667 }
668
669 if (nlk->pid) {
670 if (nladdr->nl_pid != nlk->pid)
671 return -EINVAL;
672 } else {
673 err = nladdr->nl_pid ?
674 netlink_insert(sk, net, nladdr->nl_pid) :
675 netlink_autobind(sock);
676 if (err)
677 return err;
678 }
679
680 if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
681 return 0;
682
683 netlink_table_grab();
684 netlink_update_subscriptions(sk, nlk->subscriptions +
685 hweight32(nladdr->nl_groups) -
686 hweight32(nlk->groups[0]));
687 nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups;
688 netlink_update_listeners(sk);
689 netlink_table_ungrab();
690
691 if (nlk->netlink_bind && nlk->groups[0]) {
692 int i;
693
694 for (i=0; i<nlk->ngroups; i++) {
695 if (test_bit(i, nlk->groups))
696 nlk->netlink_bind(i);
697 }
698 }
699
700 return 0;
701 }
702
703 static int netlink_connect(struct socket *sock, struct sockaddr *addr,
704 int alen, int flags)
705 {
706 int err = 0;
707 struct sock *sk = sock->sk;
708 struct netlink_sock *nlk = nlk_sk(sk);
709 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
710
711 if (alen < sizeof(addr->sa_family))
712 return -EINVAL;
713
714 if (addr->sa_family == AF_UNSPEC) {
715 sk->sk_state = NETLINK_UNCONNECTED;
716 nlk->dst_pid = 0;
717 nlk->dst_group = 0;
718 return 0;
719 }
720 if (addr->sa_family != AF_NETLINK)
721 return -EINVAL;
722
723 /* Only superuser is allowed to send multicasts */
724 if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND))
725 return -EPERM;
726
727 if (!nlk->pid)
728 err = netlink_autobind(sock);
729
730 if (err == 0) {
731 sk->sk_state = NETLINK_CONNECTED;
732 nlk->dst_pid = nladdr->nl_pid;
733 nlk->dst_group = ffs(nladdr->nl_groups);
734 }
735
736 return err;
737 }
738
739 static int netlink_getname(struct socket *sock, struct sockaddr *addr,
740 int *addr_len, int peer)
741 {
742 struct sock *sk = sock->sk;
743 struct netlink_sock *nlk = nlk_sk(sk);
744 DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr);
745
746 nladdr->nl_family = AF_NETLINK;
747 nladdr->nl_pad = 0;
748 *addr_len = sizeof(*nladdr);
749
750 if (peer) {
751 nladdr->nl_pid = nlk->dst_pid;
752 nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
753 } else {
754 nladdr->nl_pid = nlk->pid;
755 nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
756 }
757 return 0;
758 }
759
760 static void netlink_overrun(struct sock *sk)
761 {
762 struct netlink_sock *nlk = nlk_sk(sk);
763
764 if (!(nlk->flags & NETLINK_RECV_NO_ENOBUFS)) {
765 if (!test_and_set_bit(0, &nlk_sk(sk)->state)) {
766 sk->sk_err = ENOBUFS;
767 sk->sk_error_report(sk);
768 }
769 }
770 atomic_inc(&sk->sk_drops);
771 }
772
773 static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid)
774 {
775 struct sock *sock;
776 struct netlink_sock *nlk;
777
778 sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, pid);
779 if (!sock)
780 return ERR_PTR(-ECONNREFUSED);
781
782 /* Don't bother queuing skb if kernel socket has no input function */
783 nlk = nlk_sk(sock);
784 if (sock->sk_state == NETLINK_CONNECTED &&
785 nlk->dst_pid != nlk_sk(ssk)->pid) {
786 sock_put(sock);
787 return ERR_PTR(-ECONNREFUSED);
788 }
789 return sock;
790 }
791
792 struct sock *netlink_getsockbyfilp(struct file *filp)
793 {
794 struct inode *inode = filp->f_path.dentry->d_inode;
795 struct sock *sock;
796
797 if (!S_ISSOCK(inode->i_mode))
798 return ERR_PTR(-ENOTSOCK);
799
800 sock = SOCKET_I(inode)->sk;
801 if (sock->sk_family != AF_NETLINK)
802 return ERR_PTR(-EINVAL);
803
804 sock_hold(sock);
805 return sock;
806 }
807
808 /*
809 * Attach a skb to a netlink socket.
810 * The caller must hold a reference to the destination socket. On error, the
811 * reference is dropped. The skb is not send to the destination, just all
812 * all error checks are performed and memory in the queue is reserved.
813 * Return values:
814 * < 0: error. skb freed, reference to sock dropped.
815 * 0: continue
816 * 1: repeat lookup - reference dropped while waiting for socket memory.
817 */
818 int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
819 long *timeo, struct sock *ssk)
820 {
821 struct netlink_sock *nlk;
822
823 nlk = nlk_sk(sk);
824
825 if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
826 test_bit(0, &nlk->state)) {
827 DECLARE_WAITQUEUE(wait, current);
828 if (!*timeo) {
829 if (!ssk || netlink_is_kernel(ssk))
830 netlink_overrun(sk);
831 sock_put(sk);
832 kfree_skb(skb);
833 return -EAGAIN;
834 }
835
836 __set_current_state(TASK_INTERRUPTIBLE);
837 add_wait_queue(&nlk->wait, &wait);
838
839 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
840 test_bit(0, &nlk->state)) &&
841 !sock_flag(sk, SOCK_DEAD))
842 *timeo = schedule_timeout(*timeo);
843
844 __set_current_state(TASK_RUNNING);
845 remove_wait_queue(&nlk->wait, &wait);
846 sock_put(sk);
847
848 if (signal_pending(current)) {
849 kfree_skb(skb);
850 return sock_intr_errno(*timeo);
851 }
852 return 1;
853 }
854 skb_set_owner_r(skb, sk);
855 return 0;
856 }
857
858 static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb)
859 {
860 int len = skb->len;
861
862 skb_queue_tail(&sk->sk_receive_queue, skb);
863 sk->sk_data_ready(sk, len);
864 return len;
865 }
866
867 int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
868 {
869 int len = __netlink_sendskb(sk, skb);
870
871 sock_put(sk);
872 return len;
873 }
874
875 void netlink_detachskb(struct sock *sk, struct sk_buff *skb)
876 {
877 kfree_skb(skb);
878 sock_put(sk);
879 }
880
881 static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation)
882 {
883 int delta;
884
885 skb_orphan(skb);
886
887 delta = skb->end - skb->tail;
888 if (delta * 2 < skb->truesize)
889 return skb;
890
891 if (skb_shared(skb)) {
892 struct sk_buff *nskb = skb_clone(skb, allocation);
893 if (!nskb)
894 return skb;
895 consume_skb(skb);
896 skb = nskb;
897 }
898
899 if (!pskb_expand_head(skb, 0, -delta, allocation))
900 skb->truesize -= delta;
901
902 return skb;
903 }
904
905 static void netlink_rcv_wake(struct sock *sk)
906 {
907 struct netlink_sock *nlk = nlk_sk(sk);
908
909 if (skb_queue_empty(&sk->sk_receive_queue))
910 clear_bit(0, &nlk->state);
911 if (!test_bit(0, &nlk->state))
912 wake_up_interruptible(&nlk->wait);
913 }
914
915 static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb)
916 {
917 int ret;
918 struct netlink_sock *nlk = nlk_sk(sk);
919
920 ret = -ECONNREFUSED;
921 if (nlk->netlink_rcv != NULL) {
922 ret = skb->len;
923 skb_set_owner_r(skb, sk);
924 nlk->netlink_rcv(skb);
925 consume_skb(skb);
926 } else {
927 kfree_skb(skb);
928 }
929 sock_put(sk);
930 return ret;
931 }
932
933 int netlink_unicast(struct sock *ssk, struct sk_buff *skb,
934 u32 pid, int nonblock)
935 {
936 struct sock *sk;
937 int err;
938 long timeo;
939
940 skb = netlink_trim(skb, gfp_any());
941
942 timeo = sock_sndtimeo(ssk, nonblock);
943 retry:
944 sk = netlink_getsockbypid(ssk, pid);
945 if (IS_ERR(sk)) {
946 kfree_skb(skb);
947 return PTR_ERR(sk);
948 }
949 if (netlink_is_kernel(sk))
950 return netlink_unicast_kernel(sk, skb);
951
952 if (sk_filter(sk, skb)) {
953 err = skb->len;
954 kfree_skb(skb);
955 sock_put(sk);
956 return err;
957 }
958
959 err = netlink_attachskb(sk, skb, &timeo, ssk);
960 if (err == 1)
961 goto retry;
962 if (err)
963 return err;
964
965 return netlink_sendskb(sk, skb);
966 }
967 EXPORT_SYMBOL(netlink_unicast);
968
969 int netlink_has_listeners(struct sock *sk, unsigned int group)
970 {
971 int res = 0;
972 struct listeners *listeners;
973
974 BUG_ON(!netlink_is_kernel(sk));
975
976 rcu_read_lock();
977 listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners);
978
979 if (group - 1 < nl_table[sk->sk_protocol].groups)
980 res = test_bit(group - 1, listeners->masks);
981
982 rcu_read_unlock();
983
984 return res;
985 }
986 EXPORT_SYMBOL_GPL(netlink_has_listeners);
987
988 static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb)
989 {
990 struct netlink_sock *nlk = nlk_sk(sk);
991
992 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
993 !test_bit(0, &nlk->state)) {
994 skb_set_owner_r(skb, sk);
995 __netlink_sendskb(sk, skb);
996 return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1);
997 }
998 return -1;
999 }
1000
1001 struct netlink_broadcast_data {
1002 struct sock *exclude_sk;
1003 struct net *net;
1004 u32 pid;
1005 u32 group;
1006 int failure;
1007 int delivery_failure;
1008 int congested;
1009 int delivered;
1010 gfp_t allocation;
1011 struct sk_buff *skb, *skb2;
1012 int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data);
1013 void *tx_data;
1014 };
1015
1016 static int do_one_broadcast(struct sock *sk,
1017 struct netlink_broadcast_data *p)
1018 {
1019 struct netlink_sock *nlk = nlk_sk(sk);
1020 int val;
1021
1022 if (p->exclude_sk == sk)
1023 goto out;
1024
1025 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
1026 !test_bit(p->group - 1, nlk->groups))
1027 goto out;
1028
1029 if (!net_eq(sock_net(sk), p->net))
1030 goto out;
1031
1032 if (p->failure) {
1033 netlink_overrun(sk);
1034 goto out;
1035 }
1036
1037 sock_hold(sk);
1038 if (p->skb2 == NULL) {
1039 if (skb_shared(p->skb)) {
1040 p->skb2 = skb_clone(p->skb, p->allocation);
1041 } else {
1042 p->skb2 = skb_get(p->skb);
1043 /*
1044 * skb ownership may have been set when
1045 * delivered to a previous socket.
1046 */
1047 skb_orphan(p->skb2);
1048 }
1049 }
1050 if (p->skb2 == NULL) {
1051 netlink_overrun(sk);
1052 /* Clone failed. Notify ALL listeners. */
1053 p->failure = 1;
1054 if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR)
1055 p->delivery_failure = 1;
1056 } else if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) {
1057 kfree_skb(p->skb2);
1058 p->skb2 = NULL;
1059 } else if (sk_filter(sk, p->skb2)) {
1060 kfree_skb(p->skb2);
1061 p->skb2 = NULL;
1062 } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) {
1063 netlink_overrun(sk);
1064 if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR)
1065 p->delivery_failure = 1;
1066 } else {
1067 p->congested |= val;
1068 p->delivered = 1;
1069 p->skb2 = NULL;
1070 }
1071 sock_put(sk);
1072
1073 out:
1074 return 0;
1075 }
1076
1077 int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 pid,
1078 u32 group, gfp_t allocation,
1079 int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
1080 void *filter_data)
1081 {
1082 struct net *net = sock_net(ssk);
1083 struct netlink_broadcast_data info;
1084 struct hlist_node *node;
1085 struct sock *sk;
1086
1087 skb = netlink_trim(skb, allocation);
1088
1089 info.exclude_sk = ssk;
1090 info.net = net;
1091 info.pid = pid;
1092 info.group = group;
1093 info.failure = 0;
1094 info.delivery_failure = 0;
1095 info.congested = 0;
1096 info.delivered = 0;
1097 info.allocation = allocation;
1098 info.skb = skb;
1099 info.skb2 = NULL;
1100 info.tx_filter = filter;
1101 info.tx_data = filter_data;
1102
1103 /* While we sleep in clone, do not allow to change socket list */
1104
1105 netlink_lock_table();
1106
1107 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
1108 do_one_broadcast(sk, &info);
1109
1110 consume_skb(skb);
1111
1112 netlink_unlock_table();
1113
1114 if (info.delivery_failure) {
1115 kfree_skb(info.skb2);
1116 return -ENOBUFS;
1117 }
1118 consume_skb(info.skb2);
1119
1120 if (info.delivered) {
1121 if (info.congested && (allocation & __GFP_WAIT))
1122 yield();
1123 return 0;
1124 }
1125 return -ESRCH;
1126 }
1127 EXPORT_SYMBOL(netlink_broadcast_filtered);
1128
1129 int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
1130 u32 group, gfp_t allocation)
1131 {
1132 return netlink_broadcast_filtered(ssk, skb, pid, group, allocation,
1133 NULL, NULL);
1134 }
1135 EXPORT_SYMBOL(netlink_broadcast);
1136
1137 struct netlink_set_err_data {
1138 struct sock *exclude_sk;
1139 u32 pid;
1140 u32 group;
1141 int code;
1142 };
1143
1144 static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p)
1145 {
1146 struct netlink_sock *nlk = nlk_sk(sk);
1147 int ret = 0;
1148
1149 if (sk == p->exclude_sk)
1150 goto out;
1151
1152 if (!net_eq(sock_net(sk), sock_net(p->exclude_sk)))
1153 goto out;
1154
1155 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
1156 !test_bit(p->group - 1, nlk->groups))
1157 goto out;
1158
1159 if (p->code == ENOBUFS && nlk->flags & NETLINK_RECV_NO_ENOBUFS) {
1160 ret = 1;
1161 goto out;
1162 }
1163
1164 sk->sk_err = p->code;
1165 sk->sk_error_report(sk);
1166 out:
1167 return ret;
1168 }
1169
1170 /**
1171 * netlink_set_err - report error to broadcast listeners
1172 * @ssk: the kernel netlink socket, as returned by netlink_kernel_create()
1173 * @pid: the PID of a process that we want to skip (if any)
1174 * @groups: the broadcast group that will notice the error
1175 * @code: error code, must be negative (as usual in kernelspace)
1176 *
1177 * This function returns the number of broadcast listeners that have set the
1178 * NETLINK_RECV_NO_ENOBUFS socket option.
1179 */
1180 int netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code)
1181 {
1182 struct netlink_set_err_data info;
1183 struct hlist_node *node;
1184 struct sock *sk;
1185 int ret = 0;
1186
1187 info.exclude_sk = ssk;
1188 info.pid = pid;
1189 info.group = group;
1190 /* sk->sk_err wants a positive error value */
1191 info.code = -code;
1192
1193 read_lock(&nl_table_lock);
1194
1195 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
1196 ret += do_one_set_err(sk, &info);
1197
1198 read_unlock(&nl_table_lock);
1199 return ret;
1200 }
1201 EXPORT_SYMBOL(netlink_set_err);
1202
1203 /* must be called with netlink table grabbed */
1204 static void netlink_update_socket_mc(struct netlink_sock *nlk,
1205 unsigned int group,
1206 int is_new)
1207 {
1208 int old, new = !!is_new, subscriptions;
1209
1210 old = test_bit(group - 1, nlk->groups);
1211 subscriptions = nlk->subscriptions - old + new;
1212 if (new)
1213 __set_bit(group - 1, nlk->groups);
1214 else
1215 __clear_bit(group - 1, nlk->groups);
1216 netlink_update_subscriptions(&nlk->sk, subscriptions);
1217 netlink_update_listeners(&nlk->sk);
1218 }
1219
1220 static int netlink_setsockopt(struct socket *sock, int level, int optname,
1221 char __user *optval, unsigned int optlen)
1222 {
1223 struct sock *sk = sock->sk;
1224 struct netlink_sock *nlk = nlk_sk(sk);
1225 unsigned int val = 0;
1226 int err;
1227
1228 if (level != SOL_NETLINK)
1229 return -ENOPROTOOPT;
1230
1231 if (optlen >= sizeof(int) &&
1232 get_user(val, (unsigned int __user *)optval))
1233 return -EFAULT;
1234
1235 switch (optname) {
1236 case NETLINK_PKTINFO:
1237 if (val)
1238 nlk->flags |= NETLINK_RECV_PKTINFO;
1239 else
1240 nlk->flags &= ~NETLINK_RECV_PKTINFO;
1241 err = 0;
1242 break;
1243 case NETLINK_ADD_MEMBERSHIP:
1244 case NETLINK_DROP_MEMBERSHIP: {
1245 if (!netlink_capable(sock, NL_NONROOT_RECV))
1246 return -EPERM;
1247 err = netlink_realloc_groups(sk);
1248 if (err)
1249 return err;
1250 if (!val || val - 1 >= nlk->ngroups)
1251 return -EINVAL;
1252 netlink_table_grab();
1253 netlink_update_socket_mc(nlk, val,
1254 optname == NETLINK_ADD_MEMBERSHIP);
1255 netlink_table_ungrab();
1256
1257 if (nlk->netlink_bind)
1258 nlk->netlink_bind(val);
1259
1260 err = 0;
1261 break;
1262 }
1263 case NETLINK_BROADCAST_ERROR:
1264 if (val)
1265 nlk->flags |= NETLINK_BROADCAST_SEND_ERROR;
1266 else
1267 nlk->flags &= ~NETLINK_BROADCAST_SEND_ERROR;
1268 err = 0;
1269 break;
1270 case NETLINK_NO_ENOBUFS:
1271 if (val) {
1272 nlk->flags |= NETLINK_RECV_NO_ENOBUFS;
1273 clear_bit(0, &nlk->state);
1274 wake_up_interruptible(&nlk->wait);
1275 } else {
1276 nlk->flags &= ~NETLINK_RECV_NO_ENOBUFS;
1277 }
1278 err = 0;
1279 break;
1280 default:
1281 err = -ENOPROTOOPT;
1282 }
1283 return err;
1284 }
1285
1286 static int netlink_getsockopt(struct socket *sock, int level, int optname,
1287 char __user *optval, int __user *optlen)
1288 {
1289 struct sock *sk = sock->sk;
1290 struct netlink_sock *nlk = nlk_sk(sk);
1291 int len, val, err;
1292
1293 if (level != SOL_NETLINK)
1294 return -ENOPROTOOPT;
1295
1296 if (get_user(len, optlen))
1297 return -EFAULT;
1298 if (len < 0)
1299 return -EINVAL;
1300
1301 switch (optname) {
1302 case NETLINK_PKTINFO:
1303 if (len < sizeof(int))
1304 return -EINVAL;
1305 len = sizeof(int);
1306 val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0;
1307 if (put_user(len, optlen) ||
1308 put_user(val, optval))
1309 return -EFAULT;
1310 err = 0;
1311 break;
1312 case NETLINK_BROADCAST_ERROR:
1313 if (len < sizeof(int))
1314 return -EINVAL;
1315 len = sizeof(int);
1316 val = nlk->flags & NETLINK_BROADCAST_SEND_ERROR ? 1 : 0;
1317 if (put_user(len, optlen) ||
1318 put_user(val, optval))
1319 return -EFAULT;
1320 err = 0;
1321 break;
1322 case NETLINK_NO_ENOBUFS:
1323 if (len < sizeof(int))
1324 return -EINVAL;
1325 len = sizeof(int);
1326 val = nlk->flags & NETLINK_RECV_NO_ENOBUFS ? 1 : 0;
1327 if (put_user(len, optlen) ||
1328 put_user(val, optval))
1329 return -EFAULT;
1330 err = 0;
1331 break;
1332 default:
1333 err = -ENOPROTOOPT;
1334 }
1335 return err;
1336 }
1337
1338 static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
1339 {
1340 struct nl_pktinfo info;
1341
1342 info.group = NETLINK_CB(skb).dst_group;
1343 put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info);
1344 }
1345
1346 static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
1347 struct msghdr *msg, size_t len)
1348 {
1349 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1350 struct sock *sk = sock->sk;
1351 struct netlink_sock *nlk = nlk_sk(sk);
1352 struct sockaddr_nl *addr = msg->msg_name;
1353 u32 dst_pid;
1354 u32 dst_group;
1355 struct sk_buff *skb;
1356 int err;
1357 struct scm_cookie scm;
1358
1359 if (msg->msg_flags&MSG_OOB)
1360 return -EOPNOTSUPP;
1361
1362 if (NULL == siocb->scm)
1363 siocb->scm = &scm;
1364
1365 err = scm_send(sock, msg, siocb->scm, true);
1366 if (err < 0)
1367 return err;
1368
1369 if (msg->msg_namelen) {
1370 err = -EINVAL;
1371 if (addr->nl_family != AF_NETLINK)
1372 goto out;
1373 dst_pid = addr->nl_pid;
1374 dst_group = ffs(addr->nl_groups);
1375 err = -EPERM;
1376 if ((dst_group || dst_pid) &&
1377 !netlink_capable(sock, NL_NONROOT_SEND))
1378 goto out;
1379 } else {
1380 dst_pid = nlk->dst_pid;
1381 dst_group = nlk->dst_group;
1382 }
1383
1384 if (!nlk->pid) {
1385 err = netlink_autobind(sock);
1386 if (err)
1387 goto out;
1388 }
1389
1390 err = -EMSGSIZE;
1391 if (len > sk->sk_sndbuf - 32)
1392 goto out;
1393 err = -ENOBUFS;
1394 skb = alloc_skb(len, GFP_KERNEL);
1395 if (skb == NULL)
1396 goto out;
1397
1398 NETLINK_CB(skb).pid = nlk->pid;
1399 NETLINK_CB(skb).dst_group = dst_group;
1400 memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1401
1402 err = -EFAULT;
1403 if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
1404 kfree_skb(skb);
1405 goto out;
1406 }
1407
1408 err = security_netlink_send(sk, skb);
1409 if (err) {
1410 kfree_skb(skb);
1411 goto out;
1412 }
1413
1414 if (dst_group) {
1415 atomic_inc(&skb->users);
1416 netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL);
1417 }
1418 err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT);
1419
1420 out:
1421 scm_destroy(siocb->scm);
1422 return err;
1423 }
1424
1425 static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
1426 struct msghdr *msg, size_t len,
1427 int flags)
1428 {
1429 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1430 struct scm_cookie scm;
1431 struct sock *sk = sock->sk;
1432 struct netlink_sock *nlk = nlk_sk(sk);
1433 int noblock = flags&MSG_DONTWAIT;
1434 size_t copied;
1435 struct sk_buff *skb, *data_skb;
1436 int err, ret;
1437
1438 if (flags&MSG_OOB)
1439 return -EOPNOTSUPP;
1440
1441 copied = 0;
1442
1443 skb = skb_recv_datagram(sk, flags, noblock, &err);
1444 if (skb == NULL)
1445 goto out;
1446
1447 data_skb = skb;
1448
1449 #ifdef CONFIG_COMPAT_NETLINK_MESSAGES
1450 if (unlikely(skb_shinfo(skb)->frag_list)) {
1451 /*
1452 * If this skb has a frag_list, then here that means that we
1453 * will have to use the frag_list skb's data for compat tasks
1454 * and the regular skb's data for normal (non-compat) tasks.
1455 *
1456 * If we need to send the compat skb, assign it to the
1457 * 'data_skb' variable so that it will be used below for data
1458 * copying. We keep 'skb' for everything else, including
1459 * freeing both later.
1460 */
1461 if (flags & MSG_CMSG_COMPAT)
1462 data_skb = skb_shinfo(skb)->frag_list;
1463 }
1464 #endif
1465
1466 msg->msg_namelen = 0;
1467
1468 copied = data_skb->len;
1469 if (len < copied) {
1470 msg->msg_flags |= MSG_TRUNC;
1471 copied = len;
1472 }
1473
1474 skb_reset_transport_header(data_skb);
1475 err = skb_copy_datagram_iovec(data_skb, 0, msg->msg_iov, copied);
1476
1477 if (msg->msg_name) {
1478 struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name;
1479 addr->nl_family = AF_NETLINK;
1480 addr->nl_pad = 0;
1481 addr->nl_pid = NETLINK_CB(skb).pid;
1482 addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group);
1483 msg->msg_namelen = sizeof(*addr);
1484 }
1485
1486 if (nlk->flags & NETLINK_RECV_PKTINFO)
1487 netlink_cmsg_recv_pktinfo(msg, skb);
1488
1489 if (NULL == siocb->scm) {
1490 memset(&scm, 0, sizeof(scm));
1491 siocb->scm = &scm;
1492 }
1493 siocb->scm->creds = *NETLINK_CREDS(skb);
1494 if (flags & MSG_TRUNC)
1495 copied = data_skb->len;
1496
1497 skb_free_datagram(sk, skb);
1498
1499 if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) {
1500 ret = netlink_dump(sk);
1501 if (ret) {
1502 sk->sk_err = ret;
1503 sk->sk_error_report(sk);
1504 }
1505 }
1506
1507 scm_recv(sock, msg, siocb->scm, flags);
1508 out:
1509 netlink_rcv_wake(sk);
1510 return err ? : copied;
1511 }
1512
1513 static void netlink_data_ready(struct sock *sk, int len)
1514 {
1515 BUG();
1516 }
1517
1518 /*
1519 * We export these functions to other modules. They provide a
1520 * complete set of kernel non-blocking support for message
1521 * queueing.
1522 */
1523
1524 struct sock *
1525 netlink_kernel_create(struct net *net, int unit,
1526 struct module *module,
1527 struct netlink_kernel_cfg *cfg)
1528 {
1529 struct socket *sock;
1530 struct sock *sk;
1531 struct netlink_sock *nlk;
1532 struct listeners *listeners = NULL;
1533 struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL;
1534 unsigned int groups;
1535
1536 BUG_ON(!nl_table);
1537
1538 if (unit < 0 || unit >= MAX_LINKS)
1539 return NULL;
1540
1541 if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
1542 return NULL;
1543
1544 /*
1545 * We have to just have a reference on the net from sk, but don't
1546 * get_net it. Besides, we cannot get and then put the net here.
1547 * So we create one inside init_net and the move it to net.
1548 */
1549
1550 if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0)
1551 goto out_sock_release_nosk;
1552
1553 sk = sock->sk;
1554 sk_change_net(sk, net);
1555
1556 if (!cfg || cfg->groups < 32)
1557 groups = 32;
1558 else
1559 groups = cfg->groups;
1560
1561 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
1562 if (!listeners)
1563 goto out_sock_release;
1564
1565 sk->sk_data_ready = netlink_data_ready;
1566 if (cfg && cfg->input)
1567 nlk_sk(sk)->netlink_rcv = cfg->input;
1568
1569 if (netlink_insert(sk, net, 0))
1570 goto out_sock_release;
1571
1572 nlk = nlk_sk(sk);
1573 nlk->flags |= NETLINK_KERNEL_SOCKET;
1574
1575 netlink_table_grab();
1576 if (!nl_table[unit].registered) {
1577 nl_table[unit].groups = groups;
1578 rcu_assign_pointer(nl_table[unit].listeners, listeners);
1579 nl_table[unit].cb_mutex = cb_mutex;
1580 nl_table[unit].module = module;
1581 nl_table[unit].bind = cfg ? cfg->bind : NULL;
1582 nl_table[unit].registered = 1;
1583 } else {
1584 kfree(listeners);
1585 nl_table[unit].registered++;
1586 }
1587 netlink_table_ungrab();
1588 return sk;
1589
1590 out_sock_release:
1591 kfree(listeners);
1592 netlink_kernel_release(sk);
1593 return NULL;
1594
1595 out_sock_release_nosk:
1596 sock_release(sock);
1597 return NULL;
1598 }
1599 EXPORT_SYMBOL(netlink_kernel_create);
1600
1601
1602 void
1603 netlink_kernel_release(struct sock *sk)
1604 {
1605 sk_release_kernel(sk);
1606 }
1607 EXPORT_SYMBOL(netlink_kernel_release);
1608
1609 int __netlink_change_ngroups(struct sock *sk, unsigned int groups)
1610 {
1611 struct listeners *new, *old;
1612 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
1613
1614 if (groups < 32)
1615 groups = 32;
1616
1617 if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) {
1618 new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC);
1619 if (!new)
1620 return -ENOMEM;
1621 old = rcu_dereference_protected(tbl->listeners, 1);
1622 memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups));
1623 rcu_assign_pointer(tbl->listeners, new);
1624
1625 kfree_rcu(old, rcu);
1626 }
1627 tbl->groups = groups;
1628
1629 return 0;
1630 }
1631
1632 /**
1633 * netlink_change_ngroups - change number of multicast groups
1634 *
1635 * This changes the number of multicast groups that are available
1636 * on a certain netlink family. Note that it is not possible to
1637 * change the number of groups to below 32. Also note that it does
1638 * not implicitly call netlink_clear_multicast_users() when the
1639 * number of groups is reduced.
1640 *
1641 * @sk: The kernel netlink socket, as returned by netlink_kernel_create().
1642 * @groups: The new number of groups.
1643 */
1644 int netlink_change_ngroups(struct sock *sk, unsigned int groups)
1645 {
1646 int err;
1647
1648 netlink_table_grab();
1649 err = __netlink_change_ngroups(sk, groups);
1650 netlink_table_ungrab();
1651
1652 return err;
1653 }
1654
1655 void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
1656 {
1657 struct sock *sk;
1658 struct hlist_node *node;
1659 struct netlink_table *tbl = &nl_table[ksk->sk_protocol];
1660
1661 sk_for_each_bound(sk, node, &tbl->mc_list)
1662 netlink_update_socket_mc(nlk_sk(sk), group, 0);
1663 }
1664
1665 /**
1666 * netlink_clear_multicast_users - kick off multicast listeners
1667 *
1668 * This function removes all listeners from the given group.
1669 * @ksk: The kernel netlink socket, as returned by
1670 * netlink_kernel_create().
1671 * @group: The multicast group to clear.
1672 */
1673 void netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
1674 {
1675 netlink_table_grab();
1676 __netlink_clear_multicast_users(ksk, group);
1677 netlink_table_ungrab();
1678 }
1679
1680 void netlink_set_nonroot(int protocol, unsigned int flags)
1681 {
1682 if ((unsigned int)protocol < MAX_LINKS)
1683 nl_table[protocol].nl_nonroot = flags;
1684 }
1685 EXPORT_SYMBOL(netlink_set_nonroot);
1686
1687 struct nlmsghdr *
1688 __nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, int type, int len, int flags)
1689 {
1690 struct nlmsghdr *nlh;
1691 int size = NLMSG_LENGTH(len);
1692
1693 nlh = (struct nlmsghdr*)skb_put(skb, NLMSG_ALIGN(size));
1694 nlh->nlmsg_type = type;
1695 nlh->nlmsg_len = size;
1696 nlh->nlmsg_flags = flags;
1697 nlh->nlmsg_pid = pid;
1698 nlh->nlmsg_seq = seq;
1699 if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0)
1700 memset(NLMSG_DATA(nlh) + len, 0, NLMSG_ALIGN(size) - size);
1701 return nlh;
1702 }
1703 EXPORT_SYMBOL(__nlmsg_put);
1704
1705 /*
1706 * It looks a bit ugly.
1707 * It would be better to create kernel thread.
1708 */
1709
1710 static int netlink_dump(struct sock *sk)
1711 {
1712 struct netlink_sock *nlk = nlk_sk(sk);
1713 struct netlink_callback *cb;
1714 struct sk_buff *skb = NULL;
1715 struct nlmsghdr *nlh;
1716 int len, err = -ENOBUFS;
1717 int alloc_size;
1718
1719 mutex_lock(nlk->cb_mutex);
1720
1721 cb = nlk->cb;
1722 if (cb == NULL) {
1723 err = -EINVAL;
1724 goto errout_skb;
1725 }
1726
1727 alloc_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE);
1728
1729 skb = sock_rmalloc(sk, alloc_size, 0, GFP_KERNEL);
1730 if (!skb)
1731 goto errout_skb;
1732
1733 len = cb->dump(skb, cb);
1734
1735 if (len > 0) {
1736 mutex_unlock(nlk->cb_mutex);
1737
1738 if (sk_filter(sk, skb))
1739 kfree_skb(skb);
1740 else
1741 __netlink_sendskb(sk, skb);
1742 return 0;
1743 }
1744
1745 nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI);
1746 if (!nlh)
1747 goto errout_skb;
1748
1749 nl_dump_check_consistent(cb, nlh);
1750
1751 memcpy(nlmsg_data(nlh), &len, sizeof(len));
1752
1753 if (sk_filter(sk, skb))
1754 kfree_skb(skb);
1755 else
1756 __netlink_sendskb(sk, skb);
1757
1758 if (cb->done)
1759 cb->done(cb);
1760 nlk->cb = NULL;
1761 mutex_unlock(nlk->cb_mutex);
1762
1763 netlink_consume_callback(cb);
1764 return 0;
1765
1766 errout_skb:
1767 mutex_unlock(nlk->cb_mutex);
1768 kfree_skb(skb);
1769 return err;
1770 }
1771
1772 int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
1773 const struct nlmsghdr *nlh,
1774 struct netlink_dump_control *control)
1775 {
1776 struct netlink_callback *cb;
1777 struct sock *sk;
1778 struct netlink_sock *nlk;
1779 int ret;
1780
1781 cb = kzalloc(sizeof(*cb), GFP_KERNEL);
1782 if (cb == NULL)
1783 return -ENOBUFS;
1784
1785 cb->dump = control->dump;
1786 cb->done = control->done;
1787 cb->nlh = nlh;
1788 cb->data = control->data;
1789 cb->min_dump_alloc = control->min_dump_alloc;
1790 atomic_inc(&skb->users);
1791 cb->skb = skb;
1792
1793 sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).pid);
1794 if (sk == NULL) {
1795 netlink_destroy_callback(cb);
1796 return -ECONNREFUSED;
1797 }
1798 nlk = nlk_sk(sk);
1799 /* A dump is in progress... */
1800 mutex_lock(nlk->cb_mutex);
1801 if (nlk->cb) {
1802 mutex_unlock(nlk->cb_mutex);
1803 netlink_destroy_callback(cb);
1804 sock_put(sk);
1805 return -EBUSY;
1806 }
1807 nlk->cb = cb;
1808 mutex_unlock(nlk->cb_mutex);
1809
1810 ret = netlink_dump(sk);
1811
1812 sock_put(sk);
1813
1814 if (ret)
1815 return ret;
1816
1817 /* We successfully started a dump, by returning -EINTR we
1818 * signal not to send ACK even if it was requested.
1819 */
1820 return -EINTR;
1821 }
1822 EXPORT_SYMBOL(netlink_dump_start);
1823
1824 void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
1825 {
1826 struct sk_buff *skb;
1827 struct nlmsghdr *rep;
1828 struct nlmsgerr *errmsg;
1829 size_t payload = sizeof(*errmsg);
1830
1831 /* error messages get the original request appened */
1832 if (err)
1833 payload += nlmsg_len(nlh);
1834
1835 skb = nlmsg_new(payload, GFP_KERNEL);
1836 if (!skb) {
1837 struct sock *sk;
1838
1839 sk = netlink_lookup(sock_net(in_skb->sk),
1840 in_skb->sk->sk_protocol,
1841 NETLINK_CB(in_skb).pid);
1842 if (sk) {
1843 sk->sk_err = ENOBUFS;
1844 sk->sk_error_report(sk);
1845 sock_put(sk);
1846 }
1847 return;
1848 }
1849
1850 rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
1851 NLMSG_ERROR, payload, 0);
1852 errmsg = nlmsg_data(rep);
1853 errmsg->error = err;
1854 memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh));
1855 netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
1856 }
1857 EXPORT_SYMBOL(netlink_ack);
1858
1859 int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
1860 struct nlmsghdr *))
1861 {
1862 struct nlmsghdr *nlh;
1863 int err;
1864
1865 while (skb->len >= nlmsg_total_size(0)) {
1866 int msglen;
1867
1868 nlh = nlmsg_hdr(skb);
1869 err = 0;
1870
1871 if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
1872 return 0;
1873
1874 /* Only requests are handled by the kernel */
1875 if (!(nlh->nlmsg_flags & NLM_F_REQUEST))
1876 goto ack;
1877
1878 /* Skip control messages */
1879 if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
1880 goto ack;
1881
1882 err = cb(skb, nlh);
1883 if (err == -EINTR)
1884 goto skip;
1885
1886 ack:
1887 if (nlh->nlmsg_flags & NLM_F_ACK || err)
1888 netlink_ack(skb, nlh, err);
1889
1890 skip:
1891 msglen = NLMSG_ALIGN(nlh->nlmsg_len);
1892 if (msglen > skb->len)
1893 msglen = skb->len;
1894 skb_pull(skb, msglen);
1895 }
1896
1897 return 0;
1898 }
1899 EXPORT_SYMBOL(netlink_rcv_skb);
1900
1901 /**
1902 * nlmsg_notify - send a notification netlink message
1903 * @sk: netlink socket to use
1904 * @skb: notification message
1905 * @pid: destination netlink pid for reports or 0
1906 * @group: destination multicast group or 0
1907 * @report: 1 to report back, 0 to disable
1908 * @flags: allocation flags
1909 */
1910 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid,
1911 unsigned int group, int report, gfp_t flags)
1912 {
1913 int err = 0;
1914
1915 if (group) {
1916 int exclude_pid = 0;
1917
1918 if (report) {
1919 atomic_inc(&skb->users);
1920 exclude_pid = pid;
1921 }
1922
1923 /* errors reported via destination sk->sk_err, but propagate
1924 * delivery errors if NETLINK_BROADCAST_ERROR flag is set */
1925 err = nlmsg_multicast(sk, skb, exclude_pid, group, flags);
1926 }
1927
1928 if (report) {
1929 int err2;
1930
1931 err2 = nlmsg_unicast(sk, skb, pid);
1932 if (!err || err == -ESRCH)
1933 err = err2;
1934 }
1935
1936 return err;
1937 }
1938 EXPORT_SYMBOL(nlmsg_notify);
1939
1940 #ifdef CONFIG_PROC_FS
1941 struct nl_seq_iter {
1942 struct seq_net_private p;
1943 int link;
1944 int hash_idx;
1945 };
1946
1947 static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos)
1948 {
1949 struct nl_seq_iter *iter = seq->private;
1950 int i, j;
1951 struct sock *s;
1952 struct hlist_node *node;
1953 loff_t off = 0;
1954
1955 for (i = 0; i < MAX_LINKS; i++) {
1956 struct nl_pid_hash *hash = &nl_table[i].hash;
1957
1958 for (j = 0; j <= hash->mask; j++) {
1959 sk_for_each(s, node, &hash->table[j]) {
1960 if (sock_net(s) != seq_file_net(seq))
1961 continue;
1962 if (off == pos) {
1963 iter->link = i;
1964 iter->hash_idx = j;
1965 return s;
1966 }
1967 ++off;
1968 }
1969 }
1970 }
1971 return NULL;
1972 }
1973
1974 static void *netlink_seq_start(struct seq_file *seq, loff_t *pos)
1975 __acquires(nl_table_lock)
1976 {
1977 read_lock(&nl_table_lock);
1978 return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN;
1979 }
1980
1981 static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1982 {
1983 struct sock *s;
1984 struct nl_seq_iter *iter;
1985 int i, j;
1986
1987 ++*pos;
1988
1989 if (v == SEQ_START_TOKEN)
1990 return netlink_seq_socket_idx(seq, 0);
1991
1992 iter = seq->private;
1993 s = v;
1994 do {
1995 s = sk_next(s);
1996 } while (s && sock_net(s) != seq_file_net(seq));
1997 if (s)
1998 return s;
1999
2000 i = iter->link;
2001 j = iter->hash_idx + 1;
2002
2003 do {
2004 struct nl_pid_hash *hash = &nl_table[i].hash;
2005
2006 for (; j <= hash->mask; j++) {
2007 s = sk_head(&hash->table[j]);
2008 while (s && sock_net(s) != seq_file_net(seq))
2009 s = sk_next(s);
2010 if (s) {
2011 iter->link = i;
2012 iter->hash_idx = j;
2013 return s;
2014 }
2015 }
2016
2017 j = 0;
2018 } while (++i < MAX_LINKS);
2019
2020 return NULL;
2021 }
2022
2023 static void netlink_seq_stop(struct seq_file *seq, void *v)
2024 __releases(nl_table_lock)
2025 {
2026 read_unlock(&nl_table_lock);
2027 }
2028
2029
2030 static int netlink_seq_show(struct seq_file *seq, void *v)
2031 {
2032 if (v == SEQ_START_TOKEN) {
2033 seq_puts(seq,
2034 "sk Eth Pid Groups "
2035 "Rmem Wmem Dump Locks Drops Inode\n");
2036 } else {
2037 struct sock *s = v;
2038 struct netlink_sock *nlk = nlk_sk(s);
2039
2040 seq_printf(seq, "%pK %-3d %-6d %08x %-8d %-8d %pK %-8d %-8d %-8lu\n",
2041 s,
2042 s->sk_protocol,
2043 nlk->pid,
2044 nlk->groups ? (u32)nlk->groups[0] : 0,
2045 sk_rmem_alloc_get(s),
2046 sk_wmem_alloc_get(s),
2047 nlk->cb,
2048 atomic_read(&s->sk_refcnt),
2049 atomic_read(&s->sk_drops),
2050 sock_i_ino(s)
2051 );
2052
2053 }
2054 return 0;
2055 }
2056
2057 static const struct seq_operations netlink_seq_ops = {
2058 .start = netlink_seq_start,
2059 .next = netlink_seq_next,
2060 .stop = netlink_seq_stop,
2061 .show = netlink_seq_show,
2062 };
2063
2064
2065 static int netlink_seq_open(struct inode *inode, struct file *file)
2066 {
2067 return seq_open_net(inode, file, &netlink_seq_ops,
2068 sizeof(struct nl_seq_iter));
2069 }
2070
2071 static const struct file_operations netlink_seq_fops = {
2072 .owner = THIS_MODULE,
2073 .open = netlink_seq_open,
2074 .read = seq_read,
2075 .llseek = seq_lseek,
2076 .release = seq_release_net,
2077 };
2078
2079 #endif
2080
2081 int netlink_register_notifier(struct notifier_block *nb)
2082 {
2083 return atomic_notifier_chain_register(&netlink_chain, nb);
2084 }
2085 EXPORT_SYMBOL(netlink_register_notifier);
2086
2087 int netlink_unregister_notifier(struct notifier_block *nb)
2088 {
2089 return atomic_notifier_chain_unregister(&netlink_chain, nb);
2090 }
2091 EXPORT_SYMBOL(netlink_unregister_notifier);
2092
2093 static const struct proto_ops netlink_ops = {
2094 .family = PF_NETLINK,
2095 .owner = THIS_MODULE,
2096 .release = netlink_release,
2097 .bind = netlink_bind,
2098 .connect = netlink_connect,
2099 .socketpair = sock_no_socketpair,
2100 .accept = sock_no_accept,
2101 .getname = netlink_getname,
2102 .poll = datagram_poll,
2103 .ioctl = sock_no_ioctl,
2104 .listen = sock_no_listen,
2105 .shutdown = sock_no_shutdown,
2106 .setsockopt = netlink_setsockopt,
2107 .getsockopt = netlink_getsockopt,
2108 .sendmsg = netlink_sendmsg,
2109 .recvmsg = netlink_recvmsg,
2110 .mmap = sock_no_mmap,
2111 .sendpage = sock_no_sendpage,
2112 };
2113
2114 static const struct net_proto_family netlink_family_ops = {
2115 .family = PF_NETLINK,
2116 .create = netlink_create,
2117 .owner = THIS_MODULE, /* for consistency 8) */
2118 };
2119
2120 static int __net_init netlink_net_init(struct net *net)
2121 {
2122 #ifdef CONFIG_PROC_FS
2123 if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops))
2124 return -ENOMEM;
2125 #endif
2126 return 0;
2127 }
2128
2129 static void __net_exit netlink_net_exit(struct net *net)
2130 {
2131 #ifdef CONFIG_PROC_FS
2132 proc_net_remove(net, "netlink");
2133 #endif
2134 }
2135
2136 static void __init netlink_add_usersock_entry(void)
2137 {
2138 struct listeners *listeners;
2139 int groups = 32;
2140
2141 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
2142 if (!listeners)
2143 panic("netlink_add_usersock_entry: Cannot allocate listeners\n");
2144
2145 netlink_table_grab();
2146
2147 nl_table[NETLINK_USERSOCK].groups = groups;
2148 rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners);
2149 nl_table[NETLINK_USERSOCK].module = THIS_MODULE;
2150 nl_table[NETLINK_USERSOCK].registered = 1;
2151 nl_table[NETLINK_USERSOCK].nl_nonroot = NL_NONROOT_SEND;
2152
2153 netlink_table_ungrab();
2154 }
2155
2156 static struct pernet_operations __net_initdata netlink_net_ops = {
2157 .init = netlink_net_init,
2158 .exit = netlink_net_exit,
2159 };
2160
2161 static int __init netlink_proto_init(void)
2162 {
2163 struct sk_buff *dummy_skb;
2164 int i;
2165 unsigned long limit;
2166 unsigned int order;
2167 int err = proto_register(&netlink_proto, 0);
2168
2169 if (err != 0)
2170 goto out;
2171
2172 BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb));
2173
2174 nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);
2175 if (!nl_table)
2176 goto panic;
2177
2178 if (totalram_pages >= (128 * 1024))
2179 limit = totalram_pages >> (21 - PAGE_SHIFT);
2180 else
2181 limit = totalram_pages >> (23 - PAGE_SHIFT);
2182
2183 order = get_bitmask_order(limit) - 1 + PAGE_SHIFT;
2184 limit = (1UL << order) / sizeof(struct hlist_head);
2185 order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1;
2186
2187 for (i = 0; i < MAX_LINKS; i++) {
2188 struct nl_pid_hash *hash = &nl_table[i].hash;
2189
2190 hash->table = nl_pid_hash_zalloc(1 * sizeof(*hash->table));
2191 if (!hash->table) {
2192 while (i-- > 0)
2193 nl_pid_hash_free(nl_table[i].hash.table,
2194 1 * sizeof(*hash->table));
2195 kfree(nl_table);
2196 goto panic;
2197 }
2198 hash->max_shift = order;
2199 hash->shift = 0;
2200 hash->mask = 0;
2201 hash->rehash_time = jiffies;
2202 }
2203
2204 netlink_add_usersock_entry();
2205
2206 sock_register(&netlink_family_ops);
2207 register_pernet_subsys(&netlink_net_ops);
2208 /* The netlink device handler may be needed early. */
2209 rtnetlink_init();
2210 out:
2211 return err;
2212 panic:
2213 panic("netlink_init: Cannot allocate nl_table\n");
2214 }
2215
2216 core_initcall(netlink_proto_init);
Linux kernel - Deliverables
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