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[mirror_ubuntu-hirsute-kernel.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 * Patrick McHardy <kaber@trash.net>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 *
13 * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith
14 * added netlink_proto_exit
15 * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br>
16 * use nlk_sk, as sk->protinfo is on a diet 8)
17 * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org>
18 * - inc module use count of module that owns
19 * the kernel socket in case userspace opens
20 * socket of same protocol
21 * - remove all module support, since netlink is
22 * mandatory if CONFIG_NET=y these days
23 */
24
25 #include <linux/module.h>
26
27 #include <linux/capability.h>
28 #include <linux/kernel.h>
29 #include <linux/init.h>
30 #include <linux/signal.h>
31 #include <linux/sched.h>
32 #include <linux/errno.h>
33 #include <linux/string.h>
34 #include <linux/stat.h>
35 #include <linux/socket.h>
36 #include <linux/un.h>
37 #include <linux/fcntl.h>
38 #include <linux/termios.h>
39 #include <linux/sockios.h>
40 #include <linux/net.h>
41 #include <linux/fs.h>
42 #include <linux/slab.h>
43 #include <linux/uaccess.h>
44 #include <linux/skbuff.h>
45 #include <linux/netdevice.h>
46 #include <linux/rtnetlink.h>
47 #include <linux/proc_fs.h>
48 #include <linux/seq_file.h>
49 #include <linux/notifier.h>
50 #include <linux/security.h>
51 #include <linux/jhash.h>
52 #include <linux/jiffies.h>
53 #include <linux/random.h>
54 #include <linux/bitops.h>
55 #include <linux/mm.h>
56 #include <linux/types.h>
57 #include <linux/audit.h>
58 #include <linux/mutex.h>
59 #include <linux/vmalloc.h>
60 #include <linux/if_arp.h>
61 #include <linux/rhashtable.h>
62 #include <asm/cacheflush.h>
63 #include <linux/hash.h>
64 #include <linux/genetlink.h>
65 #include <linux/net_namespace.h>
66 #include <linux/nospec.h>
67
68 #include <net/net_namespace.h>
69 #include <net/netns/generic.h>
70 #include <net/sock.h>
71 #include <net/scm.h>
72 #include <net/netlink.h>
73
74 #include "af_netlink.h"
75
76 struct listeners {
77 struct rcu_head rcu;
78 unsigned long masks[0];
79 };
80
81 /* state bits */
82 #define NETLINK_S_CONGESTED 0x0
83
84 static inline int netlink_is_kernel(struct sock *sk)
85 {
86 return nlk_sk(sk)->flags & NETLINK_F_KERNEL_SOCKET;
87 }
88
89 struct netlink_table *nl_table __read_mostly;
90 EXPORT_SYMBOL_GPL(nl_table);
91
92 static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
93
94 static struct lock_class_key nlk_cb_mutex_keys[MAX_LINKS];
95
96 static const char *const nlk_cb_mutex_key_strings[MAX_LINKS + 1] = {
97 "nlk_cb_mutex-ROUTE",
98 "nlk_cb_mutex-1",
99 "nlk_cb_mutex-USERSOCK",
100 "nlk_cb_mutex-FIREWALL",
101 "nlk_cb_mutex-SOCK_DIAG",
102 "nlk_cb_mutex-NFLOG",
103 "nlk_cb_mutex-XFRM",
104 "nlk_cb_mutex-SELINUX",
105 "nlk_cb_mutex-ISCSI",
106 "nlk_cb_mutex-AUDIT",
107 "nlk_cb_mutex-FIB_LOOKUP",
108 "nlk_cb_mutex-CONNECTOR",
109 "nlk_cb_mutex-NETFILTER",
110 "nlk_cb_mutex-IP6_FW",
111 "nlk_cb_mutex-DNRTMSG",
112 "nlk_cb_mutex-KOBJECT_UEVENT",
113 "nlk_cb_mutex-GENERIC",
114 "nlk_cb_mutex-17",
115 "nlk_cb_mutex-SCSITRANSPORT",
116 "nlk_cb_mutex-ECRYPTFS",
117 "nlk_cb_mutex-RDMA",
118 "nlk_cb_mutex-CRYPTO",
119 "nlk_cb_mutex-SMC",
120 "nlk_cb_mutex-23",
121 "nlk_cb_mutex-24",
122 "nlk_cb_mutex-25",
123 "nlk_cb_mutex-26",
124 "nlk_cb_mutex-27",
125 "nlk_cb_mutex-28",
126 "nlk_cb_mutex-29",
127 "nlk_cb_mutex-30",
128 "nlk_cb_mutex-31",
129 "nlk_cb_mutex-MAX_LINKS"
130 };
131
132 static int netlink_dump(struct sock *sk);
133
134 /* nl_table locking explained:
135 * Lookup and traversal are protected with an RCU read-side lock. Insertion
136 * and removal are protected with per bucket lock while using RCU list
137 * modification primitives and may run in parallel to RCU protected lookups.
138 * Destruction of the Netlink socket may only occur *after* nl_table_lock has
139 * been acquired * either during or after the socket has been removed from
140 * the list and after an RCU grace period.
141 */
142 DEFINE_RWLOCK(nl_table_lock);
143 EXPORT_SYMBOL_GPL(nl_table_lock);
144 static atomic_t nl_table_users = ATOMIC_INIT(0);
145
146 #define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock));
147
148 static BLOCKING_NOTIFIER_HEAD(netlink_chain);
149
150
151 static const struct rhashtable_params netlink_rhashtable_params;
152
153 static inline u32 netlink_group_mask(u32 group)
154 {
155 return group ? 1 << (group - 1) : 0;
156 }
157
158 static struct sk_buff *netlink_to_full_skb(const struct sk_buff *skb,
159 gfp_t gfp_mask)
160 {
161 unsigned int len = skb_end_offset(skb);
162 struct sk_buff *new;
163
164 new = alloc_skb(len, gfp_mask);
165 if (new == NULL)
166 return NULL;
167
168 NETLINK_CB(new).portid = NETLINK_CB(skb).portid;
169 NETLINK_CB(new).dst_group = NETLINK_CB(skb).dst_group;
170 NETLINK_CB(new).creds = NETLINK_CB(skb).creds;
171
172 skb_put_data(new, skb->data, len);
173 return new;
174 }
175
176 static unsigned int netlink_tap_net_id;
177
178 struct netlink_tap_net {
179 struct list_head netlink_tap_all;
180 struct mutex netlink_tap_lock;
181 };
182
183 int netlink_add_tap(struct netlink_tap *nt)
184 {
185 struct net *net = dev_net(nt->dev);
186 struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
187
188 if (unlikely(nt->dev->type != ARPHRD_NETLINK))
189 return -EINVAL;
190
191 mutex_lock(&nn->netlink_tap_lock);
192 list_add_rcu(&nt->list, &nn->netlink_tap_all);
193 mutex_unlock(&nn->netlink_tap_lock);
194
195 __module_get(nt->module);
196
197 return 0;
198 }
199 EXPORT_SYMBOL_GPL(netlink_add_tap);
200
201 static int __netlink_remove_tap(struct netlink_tap *nt)
202 {
203 struct net *net = dev_net(nt->dev);
204 struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
205 bool found = false;
206 struct netlink_tap *tmp;
207
208 mutex_lock(&nn->netlink_tap_lock);
209
210 list_for_each_entry(tmp, &nn->netlink_tap_all, list) {
211 if (nt == tmp) {
212 list_del_rcu(&nt->list);
213 found = true;
214 goto out;
215 }
216 }
217
218 pr_warn("__netlink_remove_tap: %p not found\n", nt);
219 out:
220 mutex_unlock(&nn->netlink_tap_lock);
221
222 if (found)
223 module_put(nt->module);
224
225 return found ? 0 : -ENODEV;
226 }
227
228 int netlink_remove_tap(struct netlink_tap *nt)
229 {
230 int ret;
231
232 ret = __netlink_remove_tap(nt);
233 synchronize_net();
234
235 return ret;
236 }
237 EXPORT_SYMBOL_GPL(netlink_remove_tap);
238
239 static __net_init int netlink_tap_init_net(struct net *net)
240 {
241 struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
242
243 INIT_LIST_HEAD(&nn->netlink_tap_all);
244 mutex_init(&nn->netlink_tap_lock);
245 return 0;
246 }
247
248 static void __net_exit netlink_tap_exit_net(struct net *net)
249 {
250 }
251
252 static struct pernet_operations netlink_tap_net_ops = {
253 .init = netlink_tap_init_net,
254 .exit = netlink_tap_exit_net,
255 .id = &netlink_tap_net_id,
256 .size = sizeof(struct netlink_tap_net),
257 };
258
259 static bool netlink_filter_tap(const struct sk_buff *skb)
260 {
261 struct sock *sk = skb->sk;
262
263 /* We take the more conservative approach and
264 * whitelist socket protocols that may pass.
265 */
266 switch (sk->sk_protocol) {
267 case NETLINK_ROUTE:
268 case NETLINK_USERSOCK:
269 case NETLINK_SOCK_DIAG:
270 case NETLINK_NFLOG:
271 case NETLINK_XFRM:
272 case NETLINK_FIB_LOOKUP:
273 case NETLINK_NETFILTER:
274 case NETLINK_GENERIC:
275 return true;
276 }
277
278 return false;
279 }
280
281 static int __netlink_deliver_tap_skb(struct sk_buff *skb,
282 struct net_device *dev)
283 {
284 struct sk_buff *nskb;
285 struct sock *sk = skb->sk;
286 int ret = -ENOMEM;
287
288 if (!net_eq(dev_net(dev), sock_net(sk)))
289 return 0;
290
291 dev_hold(dev);
292
293 if (is_vmalloc_addr(skb->head))
294 nskb = netlink_to_full_skb(skb, GFP_ATOMIC);
295 else
296 nskb = skb_clone(skb, GFP_ATOMIC);
297 if (nskb) {
298 nskb->dev = dev;
299 nskb->protocol = htons((u16) sk->sk_protocol);
300 nskb->pkt_type = netlink_is_kernel(sk) ?
301 PACKET_KERNEL : PACKET_USER;
302 skb_reset_network_header(nskb);
303 ret = dev_queue_xmit(nskb);
304 if (unlikely(ret > 0))
305 ret = net_xmit_errno(ret);
306 }
307
308 dev_put(dev);
309 return ret;
310 }
311
312 static void __netlink_deliver_tap(struct sk_buff *skb, struct netlink_tap_net *nn)
313 {
314 int ret;
315 struct netlink_tap *tmp;
316
317 if (!netlink_filter_tap(skb))
318 return;
319
320 list_for_each_entry_rcu(tmp, &nn->netlink_tap_all, list) {
321 ret = __netlink_deliver_tap_skb(skb, tmp->dev);
322 if (unlikely(ret))
323 break;
324 }
325 }
326
327 static void netlink_deliver_tap(struct net *net, struct sk_buff *skb)
328 {
329 struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
330
331 rcu_read_lock();
332
333 if (unlikely(!list_empty(&nn->netlink_tap_all)))
334 __netlink_deliver_tap(skb, nn);
335
336 rcu_read_unlock();
337 }
338
339 static void netlink_deliver_tap_kernel(struct sock *dst, struct sock *src,
340 struct sk_buff *skb)
341 {
342 if (!(netlink_is_kernel(dst) && netlink_is_kernel(src)))
343 netlink_deliver_tap(sock_net(dst), skb);
344 }
345
346 static void netlink_overrun(struct sock *sk)
347 {
348 struct netlink_sock *nlk = nlk_sk(sk);
349
350 if (!(nlk->flags & NETLINK_F_RECV_NO_ENOBUFS)) {
351 if (!test_and_set_bit(NETLINK_S_CONGESTED,
352 &nlk_sk(sk)->state)) {
353 sk->sk_err = ENOBUFS;
354 sk->sk_error_report(sk);
355 }
356 }
357 atomic_inc(&sk->sk_drops);
358 }
359
360 static void netlink_rcv_wake(struct sock *sk)
361 {
362 struct netlink_sock *nlk = nlk_sk(sk);
363
364 if (skb_queue_empty(&sk->sk_receive_queue))
365 clear_bit(NETLINK_S_CONGESTED, &nlk->state);
366 if (!test_bit(NETLINK_S_CONGESTED, &nlk->state))
367 wake_up_interruptible(&nlk->wait);
368 }
369
370 static void netlink_skb_destructor(struct sk_buff *skb)
371 {
372 if (is_vmalloc_addr(skb->head)) {
373 if (!skb->cloned ||
374 !atomic_dec_return(&(skb_shinfo(skb)->dataref)))
375 vfree(skb->head);
376
377 skb->head = NULL;
378 }
379 if (skb->sk != NULL)
380 sock_rfree(skb);
381 }
382
383 static void netlink_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
384 {
385 WARN_ON(skb->sk != NULL);
386 skb->sk = sk;
387 skb->destructor = netlink_skb_destructor;
388 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
389 sk_mem_charge(sk, skb->truesize);
390 }
391
392 static void netlink_sock_destruct(struct sock *sk)
393 {
394 struct netlink_sock *nlk = nlk_sk(sk);
395
396 if (nlk->cb_running) {
397 if (nlk->cb.done)
398 nlk->cb.done(&nlk->cb);
399 module_put(nlk->cb.module);
400 kfree_skb(nlk->cb.skb);
401 }
402
403 skb_queue_purge(&sk->sk_receive_queue);
404
405 if (!sock_flag(sk, SOCK_DEAD)) {
406 printk(KERN_ERR "Freeing alive netlink socket %p\n", sk);
407 return;
408 }
409
410 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
411 WARN_ON(refcount_read(&sk->sk_wmem_alloc));
412 WARN_ON(nlk_sk(sk)->groups);
413 }
414
415 static void netlink_sock_destruct_work(struct work_struct *work)
416 {
417 struct netlink_sock *nlk = container_of(work, struct netlink_sock,
418 work);
419
420 sk_free(&nlk->sk);
421 }
422
423 /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on
424 * SMP. Look, when several writers sleep and reader wakes them up, all but one
425 * immediately hit write lock and grab all the cpus. Exclusive sleep solves
426 * this, _but_ remember, it adds useless work on UP machines.
427 */
428
429 void netlink_table_grab(void)
430 __acquires(nl_table_lock)
431 {
432 might_sleep();
433
434 write_lock_irq(&nl_table_lock);
435
436 if (atomic_read(&nl_table_users)) {
437 DECLARE_WAITQUEUE(wait, current);
438
439 add_wait_queue_exclusive(&nl_table_wait, &wait);
440 for (;;) {
441 set_current_state(TASK_UNINTERRUPTIBLE);
442 if (atomic_read(&nl_table_users) == 0)
443 break;
444 write_unlock_irq(&nl_table_lock);
445 schedule();
446 write_lock_irq(&nl_table_lock);
447 }
448
449 __set_current_state(TASK_RUNNING);
450 remove_wait_queue(&nl_table_wait, &wait);
451 }
452 }
453
454 void netlink_table_ungrab(void)
455 __releases(nl_table_lock)
456 {
457 write_unlock_irq(&nl_table_lock);
458 wake_up(&nl_table_wait);
459 }
460
461 static inline void
462 netlink_lock_table(void)
463 {
464 /* read_lock() synchronizes us to netlink_table_grab */
465
466 read_lock(&nl_table_lock);
467 atomic_inc(&nl_table_users);
468 read_unlock(&nl_table_lock);
469 }
470
471 static inline void
472 netlink_unlock_table(void)
473 {
474 if (atomic_dec_and_test(&nl_table_users))
475 wake_up(&nl_table_wait);
476 }
477
478 struct netlink_compare_arg
479 {
480 possible_net_t pnet;
481 u32 portid;
482 };
483
484 /* Doing sizeof directly may yield 4 extra bytes on 64-bit. */
485 #define netlink_compare_arg_len \
486 (offsetof(struct netlink_compare_arg, portid) + sizeof(u32))
487
488 static inline int netlink_compare(struct rhashtable_compare_arg *arg,
489 const void *ptr)
490 {
491 const struct netlink_compare_arg *x = arg->key;
492 const struct netlink_sock *nlk = ptr;
493
494 return nlk->portid != x->portid ||
495 !net_eq(sock_net(&nlk->sk), read_pnet(&x->pnet));
496 }
497
498 static void netlink_compare_arg_init(struct netlink_compare_arg *arg,
499 struct net *net, u32 portid)
500 {
501 memset(arg, 0, sizeof(*arg));
502 write_pnet(&arg->pnet, net);
503 arg->portid = portid;
504 }
505
506 static struct sock *__netlink_lookup(struct netlink_table *table, u32 portid,
507 struct net *net)
508 {
509 struct netlink_compare_arg arg;
510
511 netlink_compare_arg_init(&arg, net, portid);
512 return rhashtable_lookup_fast(&table->hash, &arg,
513 netlink_rhashtable_params);
514 }
515
516 static int __netlink_insert(struct netlink_table *table, struct sock *sk)
517 {
518 struct netlink_compare_arg arg;
519
520 netlink_compare_arg_init(&arg, sock_net(sk), nlk_sk(sk)->portid);
521 return rhashtable_lookup_insert_key(&table->hash, &arg,
522 &nlk_sk(sk)->node,
523 netlink_rhashtable_params);
524 }
525
526 static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid)
527 {
528 struct netlink_table *table = &nl_table[protocol];
529 struct sock *sk;
530
531 rcu_read_lock();
532 sk = __netlink_lookup(table, portid, net);
533 if (sk)
534 sock_hold(sk);
535 rcu_read_unlock();
536
537 return sk;
538 }
539
540 static const struct proto_ops netlink_ops;
541
542 static void
543 netlink_update_listeners(struct sock *sk)
544 {
545 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
546 unsigned long mask;
547 unsigned int i;
548 struct listeners *listeners;
549
550 listeners = nl_deref_protected(tbl->listeners);
551 if (!listeners)
552 return;
553
554 for (i = 0; i < NLGRPLONGS(tbl->groups); i++) {
555 mask = 0;
556 sk_for_each_bound(sk, &tbl->mc_list) {
557 if (i < NLGRPLONGS(nlk_sk(sk)->ngroups))
558 mask |= nlk_sk(sk)->groups[i];
559 }
560 listeners->masks[i] = mask;
561 }
562 /* this function is only called with the netlink table "grabbed", which
563 * makes sure updates are visible before bind or setsockopt return. */
564 }
565
566 static int netlink_insert(struct sock *sk, u32 portid)
567 {
568 struct netlink_table *table = &nl_table[sk->sk_protocol];
569 int err;
570
571 lock_sock(sk);
572
573 err = nlk_sk(sk)->portid == portid ? 0 : -EBUSY;
574 if (nlk_sk(sk)->bound)
575 goto err;
576
577 nlk_sk(sk)->portid = portid;
578 sock_hold(sk);
579
580 err = __netlink_insert(table, sk);
581 if (err) {
582 /* In case the hashtable backend returns with -EBUSY
583 * from here, it must not escape to the caller.
584 */
585 if (unlikely(err == -EBUSY))
586 err = -EOVERFLOW;
587 if (err == -EEXIST)
588 err = -EADDRINUSE;
589 sock_put(sk);
590 goto err;
591 }
592
593 /* We need to ensure that the socket is hashed and visible. */
594 smp_wmb();
595 nlk_sk(sk)->bound = portid;
596
597 err:
598 release_sock(sk);
599 return err;
600 }
601
602 static void netlink_remove(struct sock *sk)
603 {
604 struct netlink_table *table;
605
606 table = &nl_table[sk->sk_protocol];
607 if (!rhashtable_remove_fast(&table->hash, &nlk_sk(sk)->node,
608 netlink_rhashtable_params)) {
609 WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
610 __sock_put(sk);
611 }
612
613 netlink_table_grab();
614 if (nlk_sk(sk)->subscriptions) {
615 __sk_del_bind_node(sk);
616 netlink_update_listeners(sk);
617 }
618 if (sk->sk_protocol == NETLINK_GENERIC)
619 atomic_inc(&genl_sk_destructing_cnt);
620 netlink_table_ungrab();
621 }
622
623 static struct proto netlink_proto = {
624 .name = "NETLINK",
625 .owner = THIS_MODULE,
626 .obj_size = sizeof(struct netlink_sock),
627 };
628
629 static int __netlink_create(struct net *net, struct socket *sock,
630 struct mutex *cb_mutex, int protocol,
631 int kern)
632 {
633 struct sock *sk;
634 struct netlink_sock *nlk;
635
636 sock->ops = &netlink_ops;
637
638 sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto, kern);
639 if (!sk)
640 return -ENOMEM;
641
642 sock_init_data(sock, sk);
643
644 nlk = nlk_sk(sk);
645 if (cb_mutex) {
646 nlk->cb_mutex = cb_mutex;
647 } else {
648 nlk->cb_mutex = &nlk->cb_def_mutex;
649 mutex_init(nlk->cb_mutex);
650 lockdep_set_class_and_name(nlk->cb_mutex,
651 nlk_cb_mutex_keys + protocol,
652 nlk_cb_mutex_key_strings[protocol]);
653 }
654 init_waitqueue_head(&nlk->wait);
655
656 sk->sk_destruct = netlink_sock_destruct;
657 sk->sk_protocol = protocol;
658 return 0;
659 }
660
661 static int netlink_create(struct net *net, struct socket *sock, int protocol,
662 int kern)
663 {
664 struct module *module = NULL;
665 struct mutex *cb_mutex;
666 struct netlink_sock *nlk;
667 int (*bind)(struct net *net, int group);
668 void (*unbind)(struct net *net, int group);
669 int err = 0;
670
671 sock->state = SS_UNCONNECTED;
672
673 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
674 return -ESOCKTNOSUPPORT;
675
676 if (protocol < 0 || protocol >= MAX_LINKS)
677 return -EPROTONOSUPPORT;
678 protocol = array_index_nospec(protocol, MAX_LINKS);
679
680 netlink_lock_table();
681 #ifdef CONFIG_MODULES
682 if (!nl_table[protocol].registered) {
683 netlink_unlock_table();
684 request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
685 netlink_lock_table();
686 }
687 #endif
688 if (nl_table[protocol].registered &&
689 try_module_get(nl_table[protocol].module))
690 module = nl_table[protocol].module;
691 else
692 err = -EPROTONOSUPPORT;
693 cb_mutex = nl_table[protocol].cb_mutex;
694 bind = nl_table[protocol].bind;
695 unbind = nl_table[protocol].unbind;
696 netlink_unlock_table();
697
698 if (err < 0)
699 goto out;
700
701 err = __netlink_create(net, sock, cb_mutex, protocol, kern);
702 if (err < 0)
703 goto out_module;
704
705 local_bh_disable();
706 sock_prot_inuse_add(net, &netlink_proto, 1);
707 local_bh_enable();
708
709 nlk = nlk_sk(sock->sk);
710 nlk->module = module;
711 nlk->netlink_bind = bind;
712 nlk->netlink_unbind = unbind;
713 out:
714 return err;
715
716 out_module:
717 module_put(module);
718 goto out;
719 }
720
721 static void deferred_put_nlk_sk(struct rcu_head *head)
722 {
723 struct netlink_sock *nlk = container_of(head, struct netlink_sock, rcu);
724 struct sock *sk = &nlk->sk;
725
726 kfree(nlk->groups);
727 nlk->groups = NULL;
728
729 if (!refcount_dec_and_test(&sk->sk_refcnt))
730 return;
731
732 if (nlk->cb_running && nlk->cb.done) {
733 INIT_WORK(&nlk->work, netlink_sock_destruct_work);
734 schedule_work(&nlk->work);
735 return;
736 }
737
738 sk_free(sk);
739 }
740
741 static int netlink_release(struct socket *sock)
742 {
743 struct sock *sk = sock->sk;
744 struct netlink_sock *nlk;
745
746 if (!sk)
747 return 0;
748
749 netlink_remove(sk);
750 sock_orphan(sk);
751 nlk = nlk_sk(sk);
752
753 /*
754 * OK. Socket is unlinked, any packets that arrive now
755 * will be purged.
756 */
757
758 /* must not acquire netlink_table_lock in any way again before unbind
759 * and notifying genetlink is done as otherwise it might deadlock
760 */
761 if (nlk->netlink_unbind) {
762 int i;
763
764 for (i = 0; i < nlk->ngroups; i++)
765 if (test_bit(i, nlk->groups))
766 nlk->netlink_unbind(sock_net(sk), i + 1);
767 }
768 if (sk->sk_protocol == NETLINK_GENERIC &&
769 atomic_dec_return(&genl_sk_destructing_cnt) == 0)
770 wake_up(&genl_sk_destructing_waitq);
771
772 sock->sk = NULL;
773 wake_up_interruptible_all(&nlk->wait);
774
775 skb_queue_purge(&sk->sk_write_queue);
776
777 if (nlk->portid && nlk->bound) {
778 struct netlink_notify n = {
779 .net = sock_net(sk),
780 .protocol = sk->sk_protocol,
781 .portid = nlk->portid,
782 };
783 blocking_notifier_call_chain(&netlink_chain,
784 NETLINK_URELEASE, &n);
785 }
786
787 module_put(nlk->module);
788
789 if (netlink_is_kernel(sk)) {
790 netlink_table_grab();
791 BUG_ON(nl_table[sk->sk_protocol].registered == 0);
792 if (--nl_table[sk->sk_protocol].registered == 0) {
793 struct listeners *old;
794
795 old = nl_deref_protected(nl_table[sk->sk_protocol].listeners);
796 RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL);
797 kfree_rcu(old, rcu);
798 nl_table[sk->sk_protocol].module = NULL;
799 nl_table[sk->sk_protocol].bind = NULL;
800 nl_table[sk->sk_protocol].unbind = NULL;
801 nl_table[sk->sk_protocol].flags = 0;
802 nl_table[sk->sk_protocol].registered = 0;
803 }
804 netlink_table_ungrab();
805 }
806
807 local_bh_disable();
808 sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1);
809 local_bh_enable();
810 call_rcu(&nlk->rcu, deferred_put_nlk_sk);
811 return 0;
812 }
813
814 static int netlink_autobind(struct socket *sock)
815 {
816 struct sock *sk = sock->sk;
817 struct net *net = sock_net(sk);
818 struct netlink_table *table = &nl_table[sk->sk_protocol];
819 s32 portid = task_tgid_vnr(current);
820 int err;
821 s32 rover = -4096;
822 bool ok;
823
824 retry:
825 cond_resched();
826 rcu_read_lock();
827 ok = !__netlink_lookup(table, portid, net);
828 rcu_read_unlock();
829 if (!ok) {
830 /* Bind collision, search negative portid values. */
831 if (rover == -4096)
832 /* rover will be in range [S32_MIN, -4097] */
833 rover = S32_MIN + prandom_u32_max(-4096 - S32_MIN);
834 else if (rover >= -4096)
835 rover = -4097;
836 portid = rover--;
837 goto retry;
838 }
839
840 err = netlink_insert(sk, portid);
841 if (err == -EADDRINUSE)
842 goto retry;
843
844 /* If 2 threads race to autobind, that is fine. */
845 if (err == -EBUSY)
846 err = 0;
847
848 return err;
849 }
850
851 /**
852 * __netlink_ns_capable - General netlink message capability test
853 * @nsp: NETLINK_CB of the socket buffer holding a netlink command from userspace.
854 * @user_ns: The user namespace of the capability to use
855 * @cap: The capability to use
856 *
857 * Test to see if the opener of the socket we received the message
858 * from had when the netlink socket was created and the sender of the
859 * message has has the capability @cap in the user namespace @user_ns.
860 */
861 bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
862 struct user_namespace *user_ns, int cap)
863 {
864 return ((nsp->flags & NETLINK_SKB_DST) ||
865 file_ns_capable(nsp->sk->sk_socket->file, user_ns, cap)) &&
866 ns_capable(user_ns, cap);
867 }
868 EXPORT_SYMBOL(__netlink_ns_capable);
869
870 /**
871 * netlink_ns_capable - General netlink message capability test
872 * @skb: socket buffer holding a netlink command from userspace
873 * @user_ns: The user namespace of the capability to use
874 * @cap: The capability to use
875 *
876 * Test to see if the opener of the socket we received the message
877 * from had when the netlink socket was created and the sender of the
878 * message has has the capability @cap in the user namespace @user_ns.
879 */
880 bool netlink_ns_capable(const struct sk_buff *skb,
881 struct user_namespace *user_ns, int cap)
882 {
883 return __netlink_ns_capable(&NETLINK_CB(skb), user_ns, cap);
884 }
885 EXPORT_SYMBOL(netlink_ns_capable);
886
887 /**
888 * netlink_capable - Netlink global message capability test
889 * @skb: socket buffer holding a netlink command from userspace
890 * @cap: The capability to use
891 *
892 * Test to see if the opener of the socket we received the message
893 * from had when the netlink socket was created and the sender of the
894 * message has has the capability @cap in all user namespaces.
895 */
896 bool netlink_capable(const struct sk_buff *skb, int cap)
897 {
898 return netlink_ns_capable(skb, &init_user_ns, cap);
899 }
900 EXPORT_SYMBOL(netlink_capable);
901
902 /**
903 * netlink_net_capable - Netlink network namespace message capability test
904 * @skb: socket buffer holding a netlink command from userspace
905 * @cap: The capability to use
906 *
907 * Test to see if the opener of the socket we received the message
908 * from had when the netlink socket was created and the sender of the
909 * message has has the capability @cap over the network namespace of
910 * the socket we received the message from.
911 */
912 bool netlink_net_capable(const struct sk_buff *skb, int cap)
913 {
914 return netlink_ns_capable(skb, sock_net(skb->sk)->user_ns, cap);
915 }
916 EXPORT_SYMBOL(netlink_net_capable);
917
918 static inline int netlink_allowed(const struct socket *sock, unsigned int flag)
919 {
920 return (nl_table[sock->sk->sk_protocol].flags & flag) ||
921 ns_capable(sock_net(sock->sk)->user_ns, CAP_NET_ADMIN);
922 }
923
924 static void
925 netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions)
926 {
927 struct netlink_sock *nlk = nlk_sk(sk);
928
929 if (nlk->subscriptions && !subscriptions)
930 __sk_del_bind_node(sk);
931 else if (!nlk->subscriptions && subscriptions)
932 sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
933 nlk->subscriptions = subscriptions;
934 }
935
936 static int netlink_realloc_groups(struct sock *sk)
937 {
938 struct netlink_sock *nlk = nlk_sk(sk);
939 unsigned int groups;
940 unsigned long *new_groups;
941 int err = 0;
942
943 netlink_table_grab();
944
945 groups = nl_table[sk->sk_protocol].groups;
946 if (!nl_table[sk->sk_protocol].registered) {
947 err = -ENOENT;
948 goto out_unlock;
949 }
950
951 if (nlk->ngroups >= groups)
952 goto out_unlock;
953
954 new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC);
955 if (new_groups == NULL) {
956 err = -ENOMEM;
957 goto out_unlock;
958 }
959 memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0,
960 NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups));
961
962 nlk->groups = new_groups;
963 nlk->ngroups = groups;
964 out_unlock:
965 netlink_table_ungrab();
966 return err;
967 }
968
969 static void netlink_undo_bind(int group, long unsigned int groups,
970 struct sock *sk)
971 {
972 struct netlink_sock *nlk = nlk_sk(sk);
973 int undo;
974
975 if (!nlk->netlink_unbind)
976 return;
977
978 for (undo = 0; undo < group; undo++)
979 if (test_bit(undo, &groups))
980 nlk->netlink_unbind(sock_net(sk), undo + 1);
981 }
982
983 static int netlink_bind(struct socket *sock, struct sockaddr *addr,
984 int addr_len)
985 {
986 struct sock *sk = sock->sk;
987 struct net *net = sock_net(sk);
988 struct netlink_sock *nlk = nlk_sk(sk);
989 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
990 int err = 0;
991 unsigned long groups;
992 bool bound;
993
994 if (addr_len < sizeof(struct sockaddr_nl))
995 return -EINVAL;
996
997 if (nladdr->nl_family != AF_NETLINK)
998 return -EINVAL;
999 groups = nladdr->nl_groups;
1000
1001 /* Only superuser is allowed to listen multicasts */
1002 if (groups) {
1003 if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV))
1004 return -EPERM;
1005 err = netlink_realloc_groups(sk);
1006 if (err)
1007 return err;
1008 }
1009
1010 if (nlk->ngroups < BITS_PER_LONG)
1011 groups &= (1UL << nlk->ngroups) - 1;
1012
1013 bound = nlk->bound;
1014 if (bound) {
1015 /* Ensure nlk->portid is up-to-date. */
1016 smp_rmb();
1017
1018 if (nladdr->nl_pid != nlk->portid)
1019 return -EINVAL;
1020 }
1021
1022 netlink_lock_table();
1023 if (nlk->netlink_bind && groups) {
1024 int group;
1025
1026 for (group = 0; group < nlk->ngroups; group++) {
1027 if (!test_bit(group, &groups))
1028 continue;
1029 err = nlk->netlink_bind(net, group + 1);
1030 if (!err)
1031 continue;
1032 netlink_undo_bind(group, groups, sk);
1033 goto unlock;
1034 }
1035 }
1036
1037 /* No need for barriers here as we return to user-space without
1038 * using any of the bound attributes.
1039 */
1040 if (!bound) {
1041 err = nladdr->nl_pid ?
1042 netlink_insert(sk, nladdr->nl_pid) :
1043 netlink_autobind(sock);
1044 if (err) {
1045 netlink_undo_bind(nlk->ngroups, groups, sk);
1046 goto unlock;
1047 }
1048 }
1049
1050 if (!groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
1051 goto unlock;
1052 netlink_unlock_table();
1053
1054 netlink_table_grab();
1055 netlink_update_subscriptions(sk, nlk->subscriptions +
1056 hweight32(groups) -
1057 hweight32(nlk->groups[0]));
1058 nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | groups;
1059 netlink_update_listeners(sk);
1060 netlink_table_ungrab();
1061
1062 return 0;
1063
1064 unlock:
1065 netlink_unlock_table();
1066 return err;
1067 }
1068
1069 static int netlink_connect(struct socket *sock, struct sockaddr *addr,
1070 int alen, int flags)
1071 {
1072 int err = 0;
1073 struct sock *sk = sock->sk;
1074 struct netlink_sock *nlk = nlk_sk(sk);
1075 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
1076
1077 if (alen < sizeof(addr->sa_family))
1078 return -EINVAL;
1079
1080 if (addr->sa_family == AF_UNSPEC) {
1081 sk->sk_state = NETLINK_UNCONNECTED;
1082 nlk->dst_portid = 0;
1083 nlk->dst_group = 0;
1084 return 0;
1085 }
1086 if (addr->sa_family != AF_NETLINK)
1087 return -EINVAL;
1088
1089 if (alen < sizeof(struct sockaddr_nl))
1090 return -EINVAL;
1091
1092 if ((nladdr->nl_groups || nladdr->nl_pid) &&
1093 !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
1094 return -EPERM;
1095
1096 /* No need for barriers here as we return to user-space without
1097 * using any of the bound attributes.
1098 */
1099 if (!nlk->bound)
1100 err = netlink_autobind(sock);
1101
1102 if (err == 0) {
1103 sk->sk_state = NETLINK_CONNECTED;
1104 nlk->dst_portid = nladdr->nl_pid;
1105 nlk->dst_group = ffs(nladdr->nl_groups);
1106 }
1107
1108 return err;
1109 }
1110
1111 static int netlink_getname(struct socket *sock, struct sockaddr *addr,
1112 int peer)
1113 {
1114 struct sock *sk = sock->sk;
1115 struct netlink_sock *nlk = nlk_sk(sk);
1116 DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr);
1117
1118 nladdr->nl_family = AF_NETLINK;
1119 nladdr->nl_pad = 0;
1120
1121 if (peer) {
1122 nladdr->nl_pid = nlk->dst_portid;
1123 nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
1124 } else {
1125 nladdr->nl_pid = nlk->portid;
1126 netlink_lock_table();
1127 nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
1128 netlink_unlock_table();
1129 }
1130 return sizeof(*nladdr);
1131 }
1132
1133 static int netlink_ioctl(struct socket *sock, unsigned int cmd,
1134 unsigned long arg)
1135 {
1136 /* try to hand this ioctl down to the NIC drivers.
1137 */
1138 return -ENOIOCTLCMD;
1139 }
1140
1141 static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid)
1142 {
1143 struct sock *sock;
1144 struct netlink_sock *nlk;
1145
1146 sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, portid);
1147 if (!sock)
1148 return ERR_PTR(-ECONNREFUSED);
1149
1150 /* Don't bother queuing skb if kernel socket has no input function */
1151 nlk = nlk_sk(sock);
1152 if (sock->sk_state == NETLINK_CONNECTED &&
1153 nlk->dst_portid != nlk_sk(ssk)->portid) {
1154 sock_put(sock);
1155 return ERR_PTR(-ECONNREFUSED);
1156 }
1157 return sock;
1158 }
1159
1160 struct sock *netlink_getsockbyfilp(struct file *filp)
1161 {
1162 struct inode *inode = file_inode(filp);
1163 struct sock *sock;
1164
1165 if (!S_ISSOCK(inode->i_mode))
1166 return ERR_PTR(-ENOTSOCK);
1167
1168 sock = SOCKET_I(inode)->sk;
1169 if (sock->sk_family != AF_NETLINK)
1170 return ERR_PTR(-EINVAL);
1171
1172 sock_hold(sock);
1173 return sock;
1174 }
1175
1176 static struct sk_buff *netlink_alloc_large_skb(unsigned int size,
1177 int broadcast)
1178 {
1179 struct sk_buff *skb;
1180 void *data;
1181
1182 if (size <= NLMSG_GOODSIZE || broadcast)
1183 return alloc_skb(size, GFP_KERNEL);
1184
1185 size = SKB_DATA_ALIGN(size) +
1186 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1187
1188 data = vmalloc(size);
1189 if (data == NULL)
1190 return NULL;
1191
1192 skb = __build_skb(data, size);
1193 if (skb == NULL)
1194 vfree(data);
1195 else
1196 skb->destructor = netlink_skb_destructor;
1197
1198 return skb;
1199 }
1200
1201 /*
1202 * Attach a skb to a netlink socket.
1203 * The caller must hold a reference to the destination socket. On error, the
1204 * reference is dropped. The skb is not send to the destination, just all
1205 * all error checks are performed and memory in the queue is reserved.
1206 * Return values:
1207 * < 0: error. skb freed, reference to sock dropped.
1208 * 0: continue
1209 * 1: repeat lookup - reference dropped while waiting for socket memory.
1210 */
1211 int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
1212 long *timeo, struct sock *ssk)
1213 {
1214 struct netlink_sock *nlk;
1215
1216 nlk = nlk_sk(sk);
1217
1218 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
1219 test_bit(NETLINK_S_CONGESTED, &nlk->state))) {
1220 DECLARE_WAITQUEUE(wait, current);
1221 if (!*timeo) {
1222 if (!ssk || netlink_is_kernel(ssk))
1223 netlink_overrun(sk);
1224 sock_put(sk);
1225 kfree_skb(skb);
1226 return -EAGAIN;
1227 }
1228
1229 __set_current_state(TASK_INTERRUPTIBLE);
1230 add_wait_queue(&nlk->wait, &wait);
1231
1232 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
1233 test_bit(NETLINK_S_CONGESTED, &nlk->state)) &&
1234 !sock_flag(sk, SOCK_DEAD))
1235 *timeo = schedule_timeout(*timeo);
1236
1237 __set_current_state(TASK_RUNNING);
1238 remove_wait_queue(&nlk->wait, &wait);
1239 sock_put(sk);
1240
1241 if (signal_pending(current)) {
1242 kfree_skb(skb);
1243 return sock_intr_errno(*timeo);
1244 }
1245 return 1;
1246 }
1247 netlink_skb_set_owner_r(skb, sk);
1248 return 0;
1249 }
1250
1251 static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb)
1252 {
1253 int len = skb->len;
1254
1255 netlink_deliver_tap(sock_net(sk), skb);
1256
1257 skb_queue_tail(&sk->sk_receive_queue, skb);
1258 sk->sk_data_ready(sk);
1259 return len;
1260 }
1261
1262 int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
1263 {
1264 int len = __netlink_sendskb(sk, skb);
1265
1266 sock_put(sk);
1267 return len;
1268 }
1269
1270 void netlink_detachskb(struct sock *sk, struct sk_buff *skb)
1271 {
1272 kfree_skb(skb);
1273 sock_put(sk);
1274 }
1275
1276 static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation)
1277 {
1278 int delta;
1279
1280 WARN_ON(skb->sk != NULL);
1281 delta = skb->end - skb->tail;
1282 if (is_vmalloc_addr(skb->head) || delta * 2 < skb->truesize)
1283 return skb;
1284
1285 if (skb_shared(skb)) {
1286 struct sk_buff *nskb = skb_clone(skb, allocation);
1287 if (!nskb)
1288 return skb;
1289 consume_skb(skb);
1290 skb = nskb;
1291 }
1292
1293 pskb_expand_head(skb, 0, -delta,
1294 (allocation & ~__GFP_DIRECT_RECLAIM) |
1295 __GFP_NOWARN | __GFP_NORETRY);
1296 return skb;
1297 }
1298
1299 static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb,
1300 struct sock *ssk)
1301 {
1302 int ret;
1303 struct netlink_sock *nlk = nlk_sk(sk);
1304
1305 ret = -ECONNREFUSED;
1306 if (nlk->netlink_rcv != NULL) {
1307 ret = skb->len;
1308 netlink_skb_set_owner_r(skb, sk);
1309 NETLINK_CB(skb).sk = ssk;
1310 netlink_deliver_tap_kernel(sk, ssk, skb);
1311 nlk->netlink_rcv(skb);
1312 consume_skb(skb);
1313 } else {
1314 kfree_skb(skb);
1315 }
1316 sock_put(sk);
1317 return ret;
1318 }
1319
1320 int netlink_unicast(struct sock *ssk, struct sk_buff *skb,
1321 u32 portid, int nonblock)
1322 {
1323 struct sock *sk;
1324 int err;
1325 long timeo;
1326
1327 skb = netlink_trim(skb, gfp_any());
1328
1329 timeo = sock_sndtimeo(ssk, nonblock);
1330 retry:
1331 sk = netlink_getsockbyportid(ssk, portid);
1332 if (IS_ERR(sk)) {
1333 kfree_skb(skb);
1334 return PTR_ERR(sk);
1335 }
1336 if (netlink_is_kernel(sk))
1337 return netlink_unicast_kernel(sk, skb, ssk);
1338
1339 if (sk_filter(sk, skb)) {
1340 err = skb->len;
1341 kfree_skb(skb);
1342 sock_put(sk);
1343 return err;
1344 }
1345
1346 err = netlink_attachskb(sk, skb, &timeo, ssk);
1347 if (err == 1)
1348 goto retry;
1349 if (err)
1350 return err;
1351
1352 return netlink_sendskb(sk, skb);
1353 }
1354 EXPORT_SYMBOL(netlink_unicast);
1355
1356 int netlink_has_listeners(struct sock *sk, unsigned int group)
1357 {
1358 int res = 0;
1359 struct listeners *listeners;
1360
1361 BUG_ON(!netlink_is_kernel(sk));
1362
1363 rcu_read_lock();
1364 listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners);
1365
1366 if (listeners && group - 1 < nl_table[sk->sk_protocol].groups)
1367 res = test_bit(group - 1, listeners->masks);
1368
1369 rcu_read_unlock();
1370
1371 return res;
1372 }
1373 EXPORT_SYMBOL_GPL(netlink_has_listeners);
1374
1375 bool netlink_strict_get_check(struct sk_buff *skb)
1376 {
1377 const struct netlink_sock *nlk = nlk_sk(NETLINK_CB(skb).sk);
1378
1379 return nlk->flags & NETLINK_F_STRICT_CHK;
1380 }
1381 EXPORT_SYMBOL_GPL(netlink_strict_get_check);
1382
1383 static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb)
1384 {
1385 struct netlink_sock *nlk = nlk_sk(sk);
1386
1387 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
1388 !test_bit(NETLINK_S_CONGESTED, &nlk->state)) {
1389 netlink_skb_set_owner_r(skb, sk);
1390 __netlink_sendskb(sk, skb);
1391 return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1);
1392 }
1393 return -1;
1394 }
1395
1396 struct netlink_broadcast_data {
1397 struct sock *exclude_sk;
1398 struct net *net;
1399 u32 portid;
1400 u32 group;
1401 int failure;
1402 int delivery_failure;
1403 int congested;
1404 int delivered;
1405 gfp_t allocation;
1406 struct sk_buff *skb, *skb2;
1407 int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data);
1408 void *tx_data;
1409 };
1410
1411 static void do_one_broadcast(struct sock *sk,
1412 struct netlink_broadcast_data *p)
1413 {
1414 struct netlink_sock *nlk = nlk_sk(sk);
1415 int val;
1416
1417 if (p->exclude_sk == sk)
1418 return;
1419
1420 if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups ||
1421 !test_bit(p->group - 1, nlk->groups))
1422 return;
1423
1424 if (!net_eq(sock_net(sk), p->net)) {
1425 if (!(nlk->flags & NETLINK_F_LISTEN_ALL_NSID))
1426 return;
1427
1428 if (!peernet_has_id(sock_net(sk), p->net))
1429 return;
1430
1431 if (!file_ns_capable(sk->sk_socket->file, p->net->user_ns,
1432 CAP_NET_BROADCAST))
1433 return;
1434 }
1435
1436 if (p->failure) {
1437 netlink_overrun(sk);
1438 return;
1439 }
1440
1441 sock_hold(sk);
1442 if (p->skb2 == NULL) {
1443 if (skb_shared(p->skb)) {
1444 p->skb2 = skb_clone(p->skb, p->allocation);
1445 } else {
1446 p->skb2 = skb_get(p->skb);
1447 /*
1448 * skb ownership may have been set when
1449 * delivered to a previous socket.
1450 */
1451 skb_orphan(p->skb2);
1452 }
1453 }
1454 if (p->skb2 == NULL) {
1455 netlink_overrun(sk);
1456 /* Clone failed. Notify ALL listeners. */
1457 p->failure = 1;
1458 if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR)
1459 p->delivery_failure = 1;
1460 goto out;
1461 }
1462 if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) {
1463 kfree_skb(p->skb2);
1464 p->skb2 = NULL;
1465 goto out;
1466 }
1467 if (sk_filter(sk, p->skb2)) {
1468 kfree_skb(p->skb2);
1469 p->skb2 = NULL;
1470 goto out;
1471 }
1472 NETLINK_CB(p->skb2).nsid = peernet2id(sock_net(sk), p->net);
1473 if (NETLINK_CB(p->skb2).nsid != NETNSA_NSID_NOT_ASSIGNED)
1474 NETLINK_CB(p->skb2).nsid_is_set = true;
1475 val = netlink_broadcast_deliver(sk, p->skb2);
1476 if (val < 0) {
1477 netlink_overrun(sk);
1478 if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR)
1479 p->delivery_failure = 1;
1480 } else {
1481 p->congested |= val;
1482 p->delivered = 1;
1483 p->skb2 = NULL;
1484 }
1485 out:
1486 sock_put(sk);
1487 }
1488
1489 int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 portid,
1490 u32 group, gfp_t allocation,
1491 int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
1492 void *filter_data)
1493 {
1494 struct net *net = sock_net(ssk);
1495 struct netlink_broadcast_data info;
1496 struct sock *sk;
1497
1498 skb = netlink_trim(skb, allocation);
1499
1500 info.exclude_sk = ssk;
1501 info.net = net;
1502 info.portid = portid;
1503 info.group = group;
1504 info.failure = 0;
1505 info.delivery_failure = 0;
1506 info.congested = 0;
1507 info.delivered = 0;
1508 info.allocation = allocation;
1509 info.skb = skb;
1510 info.skb2 = NULL;
1511 info.tx_filter = filter;
1512 info.tx_data = filter_data;
1513
1514 /* While we sleep in clone, do not allow to change socket list */
1515
1516 netlink_lock_table();
1517
1518 sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list)
1519 do_one_broadcast(sk, &info);
1520
1521 consume_skb(skb);
1522
1523 netlink_unlock_table();
1524
1525 if (info.delivery_failure) {
1526 kfree_skb(info.skb2);
1527 return -ENOBUFS;
1528 }
1529 consume_skb(info.skb2);
1530
1531 if (info.delivered) {
1532 if (info.congested && gfpflags_allow_blocking(allocation))
1533 yield();
1534 return 0;
1535 }
1536 return -ESRCH;
1537 }
1538 EXPORT_SYMBOL(netlink_broadcast_filtered);
1539
1540 int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 portid,
1541 u32 group, gfp_t allocation)
1542 {
1543 return netlink_broadcast_filtered(ssk, skb, portid, group, allocation,
1544 NULL, NULL);
1545 }
1546 EXPORT_SYMBOL(netlink_broadcast);
1547
1548 struct netlink_set_err_data {
1549 struct sock *exclude_sk;
1550 u32 portid;
1551 u32 group;
1552 int code;
1553 };
1554
1555 static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p)
1556 {
1557 struct netlink_sock *nlk = nlk_sk(sk);
1558 int ret = 0;
1559
1560 if (sk == p->exclude_sk)
1561 goto out;
1562
1563 if (!net_eq(sock_net(sk), sock_net(p->exclude_sk)))
1564 goto out;
1565
1566 if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups ||
1567 !test_bit(p->group - 1, nlk->groups))
1568 goto out;
1569
1570 if (p->code == ENOBUFS && nlk->flags & NETLINK_F_RECV_NO_ENOBUFS) {
1571 ret = 1;
1572 goto out;
1573 }
1574
1575 sk->sk_err = p->code;
1576 sk->sk_error_report(sk);
1577 out:
1578 return ret;
1579 }
1580
1581 /**
1582 * netlink_set_err - report error to broadcast listeners
1583 * @ssk: the kernel netlink socket, as returned by netlink_kernel_create()
1584 * @portid: the PORTID of a process that we want to skip (if any)
1585 * @group: the broadcast group that will notice the error
1586 * @code: error code, must be negative (as usual in kernelspace)
1587 *
1588 * This function returns the number of broadcast listeners that have set the
1589 * NETLINK_NO_ENOBUFS socket option.
1590 */
1591 int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code)
1592 {
1593 struct netlink_set_err_data info;
1594 struct sock *sk;
1595 int ret = 0;
1596
1597 info.exclude_sk = ssk;
1598 info.portid = portid;
1599 info.group = group;
1600 /* sk->sk_err wants a positive error value */
1601 info.code = -code;
1602
1603 read_lock(&nl_table_lock);
1604
1605 sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list)
1606 ret += do_one_set_err(sk, &info);
1607
1608 read_unlock(&nl_table_lock);
1609 return ret;
1610 }
1611 EXPORT_SYMBOL(netlink_set_err);
1612
1613 /* must be called with netlink table grabbed */
1614 static void netlink_update_socket_mc(struct netlink_sock *nlk,
1615 unsigned int group,
1616 int is_new)
1617 {
1618 int old, new = !!is_new, subscriptions;
1619
1620 old = test_bit(group - 1, nlk->groups);
1621 subscriptions = nlk->subscriptions - old + new;
1622 if (new)
1623 __set_bit(group - 1, nlk->groups);
1624 else
1625 __clear_bit(group - 1, nlk->groups);
1626 netlink_update_subscriptions(&nlk->sk, subscriptions);
1627 netlink_update_listeners(&nlk->sk);
1628 }
1629
1630 static int netlink_setsockopt(struct socket *sock, int level, int optname,
1631 char __user *optval, unsigned int optlen)
1632 {
1633 struct sock *sk = sock->sk;
1634 struct netlink_sock *nlk = nlk_sk(sk);
1635 unsigned int val = 0;
1636 int err;
1637
1638 if (level != SOL_NETLINK)
1639 return -ENOPROTOOPT;
1640
1641 if (optlen >= sizeof(int) &&
1642 get_user(val, (unsigned int __user *)optval))
1643 return -EFAULT;
1644
1645 switch (optname) {
1646 case NETLINK_PKTINFO:
1647 if (val)
1648 nlk->flags |= NETLINK_F_RECV_PKTINFO;
1649 else
1650 nlk->flags &= ~NETLINK_F_RECV_PKTINFO;
1651 err = 0;
1652 break;
1653 case NETLINK_ADD_MEMBERSHIP:
1654 case NETLINK_DROP_MEMBERSHIP: {
1655 if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV))
1656 return -EPERM;
1657 err = netlink_realloc_groups(sk);
1658 if (err)
1659 return err;
1660 if (!val || val - 1 >= nlk->ngroups)
1661 return -EINVAL;
1662 if (optname == NETLINK_ADD_MEMBERSHIP && nlk->netlink_bind) {
1663 err = nlk->netlink_bind(sock_net(sk), val);
1664 if (err)
1665 return err;
1666 }
1667 netlink_table_grab();
1668 netlink_update_socket_mc(nlk, val,
1669 optname == NETLINK_ADD_MEMBERSHIP);
1670 netlink_table_ungrab();
1671 if (optname == NETLINK_DROP_MEMBERSHIP && nlk->netlink_unbind)
1672 nlk->netlink_unbind(sock_net(sk), val);
1673
1674 err = 0;
1675 break;
1676 }
1677 case NETLINK_BROADCAST_ERROR:
1678 if (val)
1679 nlk->flags |= NETLINK_F_BROADCAST_SEND_ERROR;
1680 else
1681 nlk->flags &= ~NETLINK_F_BROADCAST_SEND_ERROR;
1682 err = 0;
1683 break;
1684 case NETLINK_NO_ENOBUFS:
1685 if (val) {
1686 nlk->flags |= NETLINK_F_RECV_NO_ENOBUFS;
1687 clear_bit(NETLINK_S_CONGESTED, &nlk->state);
1688 wake_up_interruptible(&nlk->wait);
1689 } else {
1690 nlk->flags &= ~NETLINK_F_RECV_NO_ENOBUFS;
1691 }
1692 err = 0;
1693 break;
1694 case NETLINK_LISTEN_ALL_NSID:
1695 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_BROADCAST))
1696 return -EPERM;
1697
1698 if (val)
1699 nlk->flags |= NETLINK_F_LISTEN_ALL_NSID;
1700 else
1701 nlk->flags &= ~NETLINK_F_LISTEN_ALL_NSID;
1702 err = 0;
1703 break;
1704 case NETLINK_CAP_ACK:
1705 if (val)
1706 nlk->flags |= NETLINK_F_CAP_ACK;
1707 else
1708 nlk->flags &= ~NETLINK_F_CAP_ACK;
1709 err = 0;
1710 break;
1711 case NETLINK_EXT_ACK:
1712 if (val)
1713 nlk->flags |= NETLINK_F_EXT_ACK;
1714 else
1715 nlk->flags &= ~NETLINK_F_EXT_ACK;
1716 err = 0;
1717 break;
1718 case NETLINK_GET_STRICT_CHK:
1719 if (val)
1720 nlk->flags |= NETLINK_F_STRICT_CHK;
1721 else
1722 nlk->flags &= ~NETLINK_F_STRICT_CHK;
1723 err = 0;
1724 break;
1725 default:
1726 err = -ENOPROTOOPT;
1727 }
1728 return err;
1729 }
1730
1731 static int netlink_getsockopt(struct socket *sock, int level, int optname,
1732 char __user *optval, int __user *optlen)
1733 {
1734 struct sock *sk = sock->sk;
1735 struct netlink_sock *nlk = nlk_sk(sk);
1736 int len, val, err;
1737
1738 if (level != SOL_NETLINK)
1739 return -ENOPROTOOPT;
1740
1741 if (get_user(len, optlen))
1742 return -EFAULT;
1743 if (len < 0)
1744 return -EINVAL;
1745
1746 switch (optname) {
1747 case NETLINK_PKTINFO:
1748 if (len < sizeof(int))
1749 return -EINVAL;
1750 len = sizeof(int);
1751 val = nlk->flags & NETLINK_F_RECV_PKTINFO ? 1 : 0;
1752 if (put_user(len, optlen) ||
1753 put_user(val, optval))
1754 return -EFAULT;
1755 err = 0;
1756 break;
1757 case NETLINK_BROADCAST_ERROR:
1758 if (len < sizeof(int))
1759 return -EINVAL;
1760 len = sizeof(int);
1761 val = nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR ? 1 : 0;
1762 if (put_user(len, optlen) ||
1763 put_user(val, optval))
1764 return -EFAULT;
1765 err = 0;
1766 break;
1767 case NETLINK_NO_ENOBUFS:
1768 if (len < sizeof(int))
1769 return -EINVAL;
1770 len = sizeof(int);
1771 val = nlk->flags & NETLINK_F_RECV_NO_ENOBUFS ? 1 : 0;
1772 if (put_user(len, optlen) ||
1773 put_user(val, optval))
1774 return -EFAULT;
1775 err = 0;
1776 break;
1777 case NETLINK_LIST_MEMBERSHIPS: {
1778 int pos, idx, shift;
1779
1780 err = 0;
1781 netlink_lock_table();
1782 for (pos = 0; pos * 8 < nlk->ngroups; pos += sizeof(u32)) {
1783 if (len - pos < sizeof(u32))
1784 break;
1785
1786 idx = pos / sizeof(unsigned long);
1787 shift = (pos % sizeof(unsigned long)) * 8;
1788 if (put_user((u32)(nlk->groups[idx] >> shift),
1789 (u32 __user *)(optval + pos))) {
1790 err = -EFAULT;
1791 break;
1792 }
1793 }
1794 if (put_user(ALIGN(nlk->ngroups / 8, sizeof(u32)), optlen))
1795 err = -EFAULT;
1796 netlink_unlock_table();
1797 break;
1798 }
1799 case NETLINK_CAP_ACK:
1800 if (len < sizeof(int))
1801 return -EINVAL;
1802 len = sizeof(int);
1803 val = nlk->flags & NETLINK_F_CAP_ACK ? 1 : 0;
1804 if (put_user(len, optlen) ||
1805 put_user(val, optval))
1806 return -EFAULT;
1807 err = 0;
1808 break;
1809 case NETLINK_EXT_ACK:
1810 if (len < sizeof(int))
1811 return -EINVAL;
1812 len = sizeof(int);
1813 val = nlk->flags & NETLINK_F_EXT_ACK ? 1 : 0;
1814 if (put_user(len, optlen) || put_user(val, optval))
1815 return -EFAULT;
1816 err = 0;
1817 break;
1818 case NETLINK_GET_STRICT_CHK:
1819 if (len < sizeof(int))
1820 return -EINVAL;
1821 len = sizeof(int);
1822 val = nlk->flags & NETLINK_F_STRICT_CHK ? 1 : 0;
1823 if (put_user(len, optlen) || put_user(val, optval))
1824 return -EFAULT;
1825 err = 0;
1826 break;
1827 default:
1828 err = -ENOPROTOOPT;
1829 }
1830 return err;
1831 }
1832
1833 static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
1834 {
1835 struct nl_pktinfo info;
1836
1837 info.group = NETLINK_CB(skb).dst_group;
1838 put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info);
1839 }
1840
1841 static void netlink_cmsg_listen_all_nsid(struct sock *sk, struct msghdr *msg,
1842 struct sk_buff *skb)
1843 {
1844 if (!NETLINK_CB(skb).nsid_is_set)
1845 return;
1846
1847 put_cmsg(msg, SOL_NETLINK, NETLINK_LISTEN_ALL_NSID, sizeof(int),
1848 &NETLINK_CB(skb).nsid);
1849 }
1850
1851 static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1852 {
1853 struct sock *sk = sock->sk;
1854 struct netlink_sock *nlk = nlk_sk(sk);
1855 DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name);
1856 u32 dst_portid;
1857 u32 dst_group;
1858 struct sk_buff *skb;
1859 int err;
1860 struct scm_cookie scm;
1861 u32 netlink_skb_flags = 0;
1862
1863 if (msg->msg_flags&MSG_OOB)
1864 return -EOPNOTSUPP;
1865
1866 err = scm_send(sock, msg, &scm, true);
1867 if (err < 0)
1868 return err;
1869
1870 if (msg->msg_namelen) {
1871 err = -EINVAL;
1872 if (msg->msg_namelen < sizeof(struct sockaddr_nl))
1873 goto out;
1874 if (addr->nl_family != AF_NETLINK)
1875 goto out;
1876 dst_portid = addr->nl_pid;
1877 dst_group = ffs(addr->nl_groups);
1878 err = -EPERM;
1879 if ((dst_group || dst_portid) &&
1880 !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
1881 goto out;
1882 netlink_skb_flags |= NETLINK_SKB_DST;
1883 } else {
1884 dst_portid = nlk->dst_portid;
1885 dst_group = nlk->dst_group;
1886 }
1887
1888 if (!nlk->bound) {
1889 err = netlink_autobind(sock);
1890 if (err)
1891 goto out;
1892 } else {
1893 /* Ensure nlk is hashed and visible. */
1894 smp_rmb();
1895 }
1896
1897 err = -EMSGSIZE;
1898 if (len > sk->sk_sndbuf - 32)
1899 goto out;
1900 err = -ENOBUFS;
1901 skb = netlink_alloc_large_skb(len, dst_group);
1902 if (skb == NULL)
1903 goto out;
1904
1905 NETLINK_CB(skb).portid = nlk->portid;
1906 NETLINK_CB(skb).dst_group = dst_group;
1907 NETLINK_CB(skb).creds = scm.creds;
1908 NETLINK_CB(skb).flags = netlink_skb_flags;
1909
1910 err = -EFAULT;
1911 if (memcpy_from_msg(skb_put(skb, len), msg, len)) {
1912 kfree_skb(skb);
1913 goto out;
1914 }
1915
1916 err = security_netlink_send(sk, skb);
1917 if (err) {
1918 kfree_skb(skb);
1919 goto out;
1920 }
1921
1922 if (dst_group) {
1923 refcount_inc(&skb->users);
1924 netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL);
1925 }
1926 err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags&MSG_DONTWAIT);
1927
1928 out:
1929 scm_destroy(&scm);
1930 return err;
1931 }
1932
1933 static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1934 int flags)
1935 {
1936 struct scm_cookie scm;
1937 struct sock *sk = sock->sk;
1938 struct netlink_sock *nlk = nlk_sk(sk);
1939 int noblock = flags&MSG_DONTWAIT;
1940 size_t copied;
1941 struct sk_buff *skb, *data_skb;
1942 int err, ret;
1943
1944 if (flags&MSG_OOB)
1945 return -EOPNOTSUPP;
1946
1947 copied = 0;
1948
1949 skb = skb_recv_datagram(sk, flags, noblock, &err);
1950 if (skb == NULL)
1951 goto out;
1952
1953 data_skb = skb;
1954
1955 #ifdef CONFIG_COMPAT_NETLINK_MESSAGES
1956 if (unlikely(skb_shinfo(skb)->frag_list)) {
1957 /*
1958 * If this skb has a frag_list, then here that means that we
1959 * will have to use the frag_list skb's data for compat tasks
1960 * and the regular skb's data for normal (non-compat) tasks.
1961 *
1962 * If we need to send the compat skb, assign it to the
1963 * 'data_skb' variable so that it will be used below for data
1964 * copying. We keep 'skb' for everything else, including
1965 * freeing both later.
1966 */
1967 if (flags & MSG_CMSG_COMPAT)
1968 data_skb = skb_shinfo(skb)->frag_list;
1969 }
1970 #endif
1971
1972 /* Record the max length of recvmsg() calls for future allocations */
1973 nlk->max_recvmsg_len = max(nlk->max_recvmsg_len, len);
1974 nlk->max_recvmsg_len = min_t(size_t, nlk->max_recvmsg_len,
1975 SKB_WITH_OVERHEAD(32768));
1976
1977 copied = data_skb->len;
1978 if (len < copied) {
1979 msg->msg_flags |= MSG_TRUNC;
1980 copied = len;
1981 }
1982
1983 skb_reset_transport_header(data_skb);
1984 err = skb_copy_datagram_msg(data_skb, 0, msg, copied);
1985
1986 if (msg->msg_name) {
1987 DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name);
1988 addr->nl_family = AF_NETLINK;
1989 addr->nl_pad = 0;
1990 addr->nl_pid = NETLINK_CB(skb).portid;
1991 addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group);
1992 msg->msg_namelen = sizeof(*addr);
1993 }
1994
1995 if (nlk->flags & NETLINK_F_RECV_PKTINFO)
1996 netlink_cmsg_recv_pktinfo(msg, skb);
1997 if (nlk->flags & NETLINK_F_LISTEN_ALL_NSID)
1998 netlink_cmsg_listen_all_nsid(sk, msg, skb);
1999
2000 memset(&scm, 0, sizeof(scm));
2001 scm.creds = *NETLINK_CREDS(skb);
2002 if (flags & MSG_TRUNC)
2003 copied = data_skb->len;
2004
2005 skb_free_datagram(sk, skb);
2006
2007 if (nlk->cb_running &&
2008 atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) {
2009 ret = netlink_dump(sk);
2010 if (ret) {
2011 sk->sk_err = -ret;
2012 sk->sk_error_report(sk);
2013 }
2014 }
2015
2016 scm_recv(sock, msg, &scm, flags);
2017 out:
2018 netlink_rcv_wake(sk);
2019 return err ? : copied;
2020 }
2021
2022 static void netlink_data_ready(struct sock *sk)
2023 {
2024 BUG();
2025 }
2026
2027 /*
2028 * We export these functions to other modules. They provide a
2029 * complete set of kernel non-blocking support for message
2030 * queueing.
2031 */
2032
2033 struct sock *
2034 __netlink_kernel_create(struct net *net, int unit, struct module *module,
2035 struct netlink_kernel_cfg *cfg)
2036 {
2037 struct socket *sock;
2038 struct sock *sk;
2039 struct netlink_sock *nlk;
2040 struct listeners *listeners = NULL;
2041 struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL;
2042 unsigned int groups;
2043
2044 BUG_ON(!nl_table);
2045
2046 if (unit < 0 || unit >= MAX_LINKS)
2047 return NULL;
2048
2049 if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
2050 return NULL;
2051
2052 if (__netlink_create(net, sock, cb_mutex, unit, 1) < 0)
2053 goto out_sock_release_nosk;
2054
2055 sk = sock->sk;
2056
2057 if (!cfg || cfg->groups < 32)
2058 groups = 32;
2059 else
2060 groups = cfg->groups;
2061
2062 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
2063 if (!listeners)
2064 goto out_sock_release;
2065
2066 sk->sk_data_ready = netlink_data_ready;
2067 if (cfg && cfg->input)
2068 nlk_sk(sk)->netlink_rcv = cfg->input;
2069
2070 if (netlink_insert(sk, 0))
2071 goto out_sock_release;
2072
2073 nlk = nlk_sk(sk);
2074 nlk->flags |= NETLINK_F_KERNEL_SOCKET;
2075
2076 netlink_table_grab();
2077 if (!nl_table[unit].registered) {
2078 nl_table[unit].groups = groups;
2079 rcu_assign_pointer(nl_table[unit].listeners, listeners);
2080 nl_table[unit].cb_mutex = cb_mutex;
2081 nl_table[unit].module = module;
2082 if (cfg) {
2083 nl_table[unit].bind = cfg->bind;
2084 nl_table[unit].unbind = cfg->unbind;
2085 nl_table[unit].flags = cfg->flags;
2086 if (cfg->compare)
2087 nl_table[unit].compare = cfg->compare;
2088 }
2089 nl_table[unit].registered = 1;
2090 } else {
2091 kfree(listeners);
2092 nl_table[unit].registered++;
2093 }
2094 netlink_table_ungrab();
2095 return sk;
2096
2097 out_sock_release:
2098 kfree(listeners);
2099 netlink_kernel_release(sk);
2100 return NULL;
2101
2102 out_sock_release_nosk:
2103 sock_release(sock);
2104 return NULL;
2105 }
2106 EXPORT_SYMBOL(__netlink_kernel_create);
2107
2108 void
2109 netlink_kernel_release(struct sock *sk)
2110 {
2111 if (sk == NULL || sk->sk_socket == NULL)
2112 return;
2113
2114 sock_release(sk->sk_socket);
2115 }
2116 EXPORT_SYMBOL(netlink_kernel_release);
2117
2118 int __netlink_change_ngroups(struct sock *sk, unsigned int groups)
2119 {
2120 struct listeners *new, *old;
2121 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
2122
2123 if (groups < 32)
2124 groups = 32;
2125
2126 if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) {
2127 new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC);
2128 if (!new)
2129 return -ENOMEM;
2130 old = nl_deref_protected(tbl->listeners);
2131 memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups));
2132 rcu_assign_pointer(tbl->listeners, new);
2133
2134 kfree_rcu(old, rcu);
2135 }
2136 tbl->groups = groups;
2137
2138 return 0;
2139 }
2140
2141 /**
2142 * netlink_change_ngroups - change number of multicast groups
2143 *
2144 * This changes the number of multicast groups that are available
2145 * on a certain netlink family. Note that it is not possible to
2146 * change the number of groups to below 32. Also note that it does
2147 * not implicitly call netlink_clear_multicast_users() when the
2148 * number of groups is reduced.
2149 *
2150 * @sk: The kernel netlink socket, as returned by netlink_kernel_create().
2151 * @groups: The new number of groups.
2152 */
2153 int netlink_change_ngroups(struct sock *sk, unsigned int groups)
2154 {
2155 int err;
2156
2157 netlink_table_grab();
2158 err = __netlink_change_ngroups(sk, groups);
2159 netlink_table_ungrab();
2160
2161 return err;
2162 }
2163
2164 void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
2165 {
2166 struct sock *sk;
2167 struct netlink_table *tbl = &nl_table[ksk->sk_protocol];
2168
2169 sk_for_each_bound(sk, &tbl->mc_list)
2170 netlink_update_socket_mc(nlk_sk(sk), group, 0);
2171 }
2172
2173 struct nlmsghdr *
2174 __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags)
2175 {
2176 struct nlmsghdr *nlh;
2177 int size = nlmsg_msg_size(len);
2178
2179 nlh = skb_put(skb, NLMSG_ALIGN(size));
2180 nlh->nlmsg_type = type;
2181 nlh->nlmsg_len = size;
2182 nlh->nlmsg_flags = flags;
2183 nlh->nlmsg_pid = portid;
2184 nlh->nlmsg_seq = seq;
2185 if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0)
2186 memset(nlmsg_data(nlh) + len, 0, NLMSG_ALIGN(size) - size);
2187 return nlh;
2188 }
2189 EXPORT_SYMBOL(__nlmsg_put);
2190
2191 /*
2192 * It looks a bit ugly.
2193 * It would be better to create kernel thread.
2194 */
2195
2196 static int netlink_dump(struct sock *sk)
2197 {
2198 struct netlink_sock *nlk = nlk_sk(sk);
2199 struct netlink_ext_ack extack = {};
2200 struct netlink_callback *cb;
2201 struct sk_buff *skb = NULL;
2202 struct nlmsghdr *nlh;
2203 struct module *module;
2204 int err = -ENOBUFS;
2205 int alloc_min_size;
2206 int alloc_size;
2207
2208 mutex_lock(nlk->cb_mutex);
2209 if (!nlk->cb_running) {
2210 err = -EINVAL;
2211 goto errout_skb;
2212 }
2213
2214 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2215 goto errout_skb;
2216
2217 /* NLMSG_GOODSIZE is small to avoid high order allocations being
2218 * required, but it makes sense to _attempt_ a 16K bytes allocation
2219 * to reduce number of system calls on dump operations, if user
2220 * ever provided a big enough buffer.
2221 */
2222 cb = &nlk->cb;
2223 alloc_min_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE);
2224
2225 if (alloc_min_size < nlk->max_recvmsg_len) {
2226 alloc_size = nlk->max_recvmsg_len;
2227 skb = alloc_skb(alloc_size,
2228 (GFP_KERNEL & ~__GFP_DIRECT_RECLAIM) |
2229 __GFP_NOWARN | __GFP_NORETRY);
2230 }
2231 if (!skb) {
2232 alloc_size = alloc_min_size;
2233 skb = alloc_skb(alloc_size, GFP_KERNEL);
2234 }
2235 if (!skb)
2236 goto errout_skb;
2237
2238 /* Trim skb to allocated size. User is expected to provide buffer as
2239 * large as max(min_dump_alloc, 16KiB (mac_recvmsg_len capped at
2240 * netlink_recvmsg())). dump will pack as many smaller messages as
2241 * could fit within the allocated skb. skb is typically allocated
2242 * with larger space than required (could be as much as near 2x the
2243 * requested size with align to next power of 2 approach). Allowing
2244 * dump to use the excess space makes it difficult for a user to have a
2245 * reasonable static buffer based on the expected largest dump of a
2246 * single netdev. The outcome is MSG_TRUNC error.
2247 */
2248 skb_reserve(skb, skb_tailroom(skb) - alloc_size);
2249 netlink_skb_set_owner_r(skb, sk);
2250
2251 if (nlk->dump_done_errno > 0) {
2252 cb->extack = &extack;
2253 nlk->dump_done_errno = cb->dump(skb, cb);
2254 cb->extack = NULL;
2255 }
2256
2257 if (nlk->dump_done_errno > 0 ||
2258 skb_tailroom(skb) < nlmsg_total_size(sizeof(nlk->dump_done_errno))) {
2259 mutex_unlock(nlk->cb_mutex);
2260
2261 if (sk_filter(sk, skb))
2262 kfree_skb(skb);
2263 else
2264 __netlink_sendskb(sk, skb);
2265 return 0;
2266 }
2267
2268 nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE,
2269 sizeof(nlk->dump_done_errno),
2270 NLM_F_MULTI | cb->answer_flags);
2271 if (WARN_ON(!nlh))
2272 goto errout_skb;
2273
2274 nl_dump_check_consistent(cb, nlh);
2275
2276 memcpy(nlmsg_data(nlh), &nlk->dump_done_errno,
2277 sizeof(nlk->dump_done_errno));
2278
2279 if (extack._msg && nlk->flags & NETLINK_F_EXT_ACK) {
2280 nlh->nlmsg_flags |= NLM_F_ACK_TLVS;
2281 if (!nla_put_string(skb, NLMSGERR_ATTR_MSG, extack._msg))
2282 nlmsg_end(skb, nlh);
2283 }
2284
2285 if (sk_filter(sk, skb))
2286 kfree_skb(skb);
2287 else
2288 __netlink_sendskb(sk, skb);
2289
2290 if (cb->done)
2291 cb->done(cb);
2292
2293 nlk->cb_running = false;
2294 module = cb->module;
2295 skb = cb->skb;
2296 mutex_unlock(nlk->cb_mutex);
2297 module_put(module);
2298 consume_skb(skb);
2299 return 0;
2300
2301 errout_skb:
2302 mutex_unlock(nlk->cb_mutex);
2303 kfree_skb(skb);
2304 return err;
2305 }
2306
2307 int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
2308 const struct nlmsghdr *nlh,
2309 struct netlink_dump_control *control)
2310 {
2311 struct netlink_sock *nlk, *nlk2;
2312 struct netlink_callback *cb;
2313 struct sock *sk;
2314 int ret;
2315
2316 refcount_inc(&skb->users);
2317
2318 sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).portid);
2319 if (sk == NULL) {
2320 ret = -ECONNREFUSED;
2321 goto error_free;
2322 }
2323
2324 nlk = nlk_sk(sk);
2325 mutex_lock(nlk->cb_mutex);
2326 /* A dump is in progress... */
2327 if (nlk->cb_running) {
2328 ret = -EBUSY;
2329 goto error_unlock;
2330 }
2331 /* add reference of module which cb->dump belongs to */
2332 if (!try_module_get(control->module)) {
2333 ret = -EPROTONOSUPPORT;
2334 goto error_unlock;
2335 }
2336
2337 cb = &nlk->cb;
2338 memset(cb, 0, sizeof(*cb));
2339 cb->dump = control->dump;
2340 cb->done = control->done;
2341 cb->nlh = nlh;
2342 cb->data = control->data;
2343 cb->module = control->module;
2344 cb->min_dump_alloc = control->min_dump_alloc;
2345 cb->skb = skb;
2346
2347 nlk2 = nlk_sk(NETLINK_CB(skb).sk);
2348 cb->strict_check = !!(nlk2->flags & NETLINK_F_STRICT_CHK);
2349
2350 if (control->start) {
2351 ret = control->start(cb);
2352 if (ret)
2353 goto error_put;
2354 }
2355
2356 nlk->cb_running = true;
2357 nlk->dump_done_errno = INT_MAX;
2358
2359 mutex_unlock(nlk->cb_mutex);
2360
2361 ret = netlink_dump(sk);
2362
2363 sock_put(sk);
2364
2365 if (ret)
2366 return ret;
2367
2368 /* We successfully started a dump, by returning -EINTR we
2369 * signal not to send ACK even if it was requested.
2370 */
2371 return -EINTR;
2372
2373 error_put:
2374 module_put(control->module);
2375 error_unlock:
2376 sock_put(sk);
2377 mutex_unlock(nlk->cb_mutex);
2378 error_free:
2379 kfree_skb(skb);
2380 return ret;
2381 }
2382 EXPORT_SYMBOL(__netlink_dump_start);
2383
2384 void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
2385 const struct netlink_ext_ack *extack)
2386 {
2387 struct sk_buff *skb;
2388 struct nlmsghdr *rep;
2389 struct nlmsgerr *errmsg;
2390 size_t payload = sizeof(*errmsg);
2391 size_t tlvlen = 0;
2392 struct netlink_sock *nlk = nlk_sk(NETLINK_CB(in_skb).sk);
2393 unsigned int flags = 0;
2394 bool nlk_has_extack = nlk->flags & NETLINK_F_EXT_ACK;
2395
2396 /* Error messages get the original request appened, unless the user
2397 * requests to cap the error message, and get extra error data if
2398 * requested.
2399 */
2400 if (nlk_has_extack && extack && extack->_msg)
2401 tlvlen += nla_total_size(strlen(extack->_msg) + 1);
2402
2403 if (err) {
2404 if (!(nlk->flags & NETLINK_F_CAP_ACK))
2405 payload += nlmsg_len(nlh);
2406 else
2407 flags |= NLM_F_CAPPED;
2408 if (nlk_has_extack && extack && extack->bad_attr)
2409 tlvlen += nla_total_size(sizeof(u32));
2410 } else {
2411 flags |= NLM_F_CAPPED;
2412
2413 if (nlk_has_extack && extack && extack->cookie_len)
2414 tlvlen += nla_total_size(extack->cookie_len);
2415 }
2416
2417 if (tlvlen)
2418 flags |= NLM_F_ACK_TLVS;
2419
2420 skb = nlmsg_new(payload + tlvlen, GFP_KERNEL);
2421 if (!skb) {
2422 NETLINK_CB(in_skb).sk->sk_err = ENOBUFS;
2423 NETLINK_CB(in_skb).sk->sk_error_report(NETLINK_CB(in_skb).sk);
2424 return;
2425 }
2426
2427 rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2428 NLMSG_ERROR, payload, flags);
2429 errmsg = nlmsg_data(rep);
2430 errmsg->error = err;
2431 memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh));
2432
2433 if (nlk_has_extack && extack) {
2434 if (extack->_msg) {
2435 WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG,
2436 extack->_msg));
2437 }
2438 if (err) {
2439 if (extack->bad_attr &&
2440 !WARN_ON((u8 *)extack->bad_attr < in_skb->data ||
2441 (u8 *)extack->bad_attr >= in_skb->data +
2442 in_skb->len))
2443 WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS,
2444 (u8 *)extack->bad_attr -
2445 in_skb->data));
2446 } else {
2447 if (extack->cookie_len)
2448 WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE,
2449 extack->cookie_len,
2450 extack->cookie));
2451 }
2452 }
2453
2454 nlmsg_end(skb, rep);
2455
2456 netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT);
2457 }
2458 EXPORT_SYMBOL(netlink_ack);
2459
2460 int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
2461 struct nlmsghdr *,
2462 struct netlink_ext_ack *))
2463 {
2464 struct netlink_ext_ack extack;
2465 struct nlmsghdr *nlh;
2466 int err;
2467
2468 while (skb->len >= nlmsg_total_size(0)) {
2469 int msglen;
2470
2471 memset(&extack, 0, sizeof(extack));
2472 nlh = nlmsg_hdr(skb);
2473 err = 0;
2474
2475 if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
2476 return 0;
2477
2478 /* Only requests are handled by the kernel */
2479 if (!(nlh->nlmsg_flags & NLM_F_REQUEST))
2480 goto ack;
2481
2482 /* Skip control messages */
2483 if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
2484 goto ack;
2485
2486 err = cb(skb, nlh, &extack);
2487 if (err == -EINTR)
2488 goto skip;
2489
2490 ack:
2491 if (nlh->nlmsg_flags & NLM_F_ACK || err)
2492 netlink_ack(skb, nlh, err, &extack);
2493
2494 skip:
2495 msglen = NLMSG_ALIGN(nlh->nlmsg_len);
2496 if (msglen > skb->len)
2497 msglen = skb->len;
2498 skb_pull(skb, msglen);
2499 }
2500
2501 return 0;
2502 }
2503 EXPORT_SYMBOL(netlink_rcv_skb);
2504
2505 /**
2506 * nlmsg_notify - send a notification netlink message
2507 * @sk: netlink socket to use
2508 * @skb: notification message
2509 * @portid: destination netlink portid for reports or 0
2510 * @group: destination multicast group or 0
2511 * @report: 1 to report back, 0 to disable
2512 * @flags: allocation flags
2513 */
2514 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
2515 unsigned int group, int report, gfp_t flags)
2516 {
2517 int err = 0;
2518
2519 if (group) {
2520 int exclude_portid = 0;
2521
2522 if (report) {
2523 refcount_inc(&skb->users);
2524 exclude_portid = portid;
2525 }
2526
2527 /* errors reported via destination sk->sk_err, but propagate
2528 * delivery errors if NETLINK_BROADCAST_ERROR flag is set */
2529 err = nlmsg_multicast(sk, skb, exclude_portid, group, flags);
2530 }
2531
2532 if (report) {
2533 int err2;
2534
2535 err2 = nlmsg_unicast(sk, skb, portid);
2536 if (!err || err == -ESRCH)
2537 err = err2;
2538 }
2539
2540 return err;
2541 }
2542 EXPORT_SYMBOL(nlmsg_notify);
2543
2544 #ifdef CONFIG_PROC_FS
2545 struct nl_seq_iter {
2546 struct seq_net_private p;
2547 struct rhashtable_iter hti;
2548 int link;
2549 };
2550
2551 static int netlink_walk_start(struct nl_seq_iter *iter)
2552 {
2553 rhashtable_walk_enter(&nl_table[iter->link].hash, &iter->hti);
2554 rhashtable_walk_start(&iter->hti);
2555
2556 return 0;
2557 }
2558
2559 static void netlink_walk_stop(struct nl_seq_iter *iter)
2560 {
2561 rhashtable_walk_stop(&iter->hti);
2562 rhashtable_walk_exit(&iter->hti);
2563 }
2564
2565 static void *__netlink_seq_next(struct seq_file *seq)
2566 {
2567 struct nl_seq_iter *iter = seq->private;
2568 struct netlink_sock *nlk;
2569
2570 do {
2571 for (;;) {
2572 int err;
2573
2574 nlk = rhashtable_walk_next(&iter->hti);
2575
2576 if (IS_ERR(nlk)) {
2577 if (PTR_ERR(nlk) == -EAGAIN)
2578 continue;
2579
2580 return nlk;
2581 }
2582
2583 if (nlk)
2584 break;
2585
2586 netlink_walk_stop(iter);
2587 if (++iter->link >= MAX_LINKS)
2588 return NULL;
2589
2590 err = netlink_walk_start(iter);
2591 if (err)
2592 return ERR_PTR(err);
2593 }
2594 } while (sock_net(&nlk->sk) != seq_file_net(seq));
2595
2596 return nlk;
2597 }
2598
2599 static void *netlink_seq_start(struct seq_file *seq, loff_t *posp)
2600 {
2601 struct nl_seq_iter *iter = seq->private;
2602 void *obj = SEQ_START_TOKEN;
2603 loff_t pos;
2604 int err;
2605
2606 iter->link = 0;
2607
2608 err = netlink_walk_start(iter);
2609 if (err)
2610 return ERR_PTR(err);
2611
2612 for (pos = *posp; pos && obj && !IS_ERR(obj); pos--)
2613 obj = __netlink_seq_next(seq);
2614
2615 return obj;
2616 }
2617
2618 static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2619 {
2620 ++*pos;
2621 return __netlink_seq_next(seq);
2622 }
2623
2624 static void netlink_seq_stop(struct seq_file *seq, void *v)
2625 {
2626 struct nl_seq_iter *iter = seq->private;
2627
2628 if (iter->link >= MAX_LINKS)
2629 return;
2630
2631 netlink_walk_stop(iter);
2632 }
2633
2634
2635 static int netlink_seq_show(struct seq_file *seq, void *v)
2636 {
2637 if (v == SEQ_START_TOKEN) {
2638 seq_puts(seq,
2639 "sk Eth Pid Groups "
2640 "Rmem Wmem Dump Locks Drops Inode\n");
2641 } else {
2642 struct sock *s = v;
2643 struct netlink_sock *nlk = nlk_sk(s);
2644
2645 seq_printf(seq, "%pK %-3d %-10u %08x %-8d %-8d %-5d %-8d %-8d %-8lu\n",
2646 s,
2647 s->sk_protocol,
2648 nlk->portid,
2649 nlk->groups ? (u32)nlk->groups[0] : 0,
2650 sk_rmem_alloc_get(s),
2651 sk_wmem_alloc_get(s),
2652 nlk->cb_running,
2653 refcount_read(&s->sk_refcnt),
2654 atomic_read(&s->sk_drops),
2655 sock_i_ino(s)
2656 );
2657
2658 }
2659 return 0;
2660 }
2661
2662 static const struct seq_operations netlink_seq_ops = {
2663 .start = netlink_seq_start,
2664 .next = netlink_seq_next,
2665 .stop = netlink_seq_stop,
2666 .show = netlink_seq_show,
2667 };
2668 #endif
2669
2670 int netlink_register_notifier(struct notifier_block *nb)
2671 {
2672 return blocking_notifier_chain_register(&netlink_chain, nb);
2673 }
2674 EXPORT_SYMBOL(netlink_register_notifier);
2675
2676 int netlink_unregister_notifier(struct notifier_block *nb)
2677 {
2678 return blocking_notifier_chain_unregister(&netlink_chain, nb);
2679 }
2680 EXPORT_SYMBOL(netlink_unregister_notifier);
2681
2682 static const struct proto_ops netlink_ops = {
2683 .family = PF_NETLINK,
2684 .owner = THIS_MODULE,
2685 .release = netlink_release,
2686 .bind = netlink_bind,
2687 .connect = netlink_connect,
2688 .socketpair = sock_no_socketpair,
2689 .accept = sock_no_accept,
2690 .getname = netlink_getname,
2691 .poll = datagram_poll,
2692 .ioctl = netlink_ioctl,
2693 .listen = sock_no_listen,
2694 .shutdown = sock_no_shutdown,
2695 .setsockopt = netlink_setsockopt,
2696 .getsockopt = netlink_getsockopt,
2697 .sendmsg = netlink_sendmsg,
2698 .recvmsg = netlink_recvmsg,
2699 .mmap = sock_no_mmap,
2700 .sendpage = sock_no_sendpage,
2701 };
2702
2703 static const struct net_proto_family netlink_family_ops = {
2704 .family = PF_NETLINK,
2705 .create = netlink_create,
2706 .owner = THIS_MODULE, /* for consistency 8) */
2707 };
2708
2709 static int __net_init netlink_net_init(struct net *net)
2710 {
2711 #ifdef CONFIG_PROC_FS
2712 if (!proc_create_net("netlink", 0, net->proc_net, &netlink_seq_ops,
2713 sizeof(struct nl_seq_iter)))
2714 return -ENOMEM;
2715 #endif
2716 return 0;
2717 }
2718
2719 static void __net_exit netlink_net_exit(struct net *net)
2720 {
2721 #ifdef CONFIG_PROC_FS
2722 remove_proc_entry("netlink", net->proc_net);
2723 #endif
2724 }
2725
2726 static void __init netlink_add_usersock_entry(void)
2727 {
2728 struct listeners *listeners;
2729 int groups = 32;
2730
2731 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
2732 if (!listeners)
2733 panic("netlink_add_usersock_entry: Cannot allocate listeners\n");
2734
2735 netlink_table_grab();
2736
2737 nl_table[NETLINK_USERSOCK].groups = groups;
2738 rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners);
2739 nl_table[NETLINK_USERSOCK].module = THIS_MODULE;
2740 nl_table[NETLINK_USERSOCK].registered = 1;
2741 nl_table[NETLINK_USERSOCK].flags = NL_CFG_F_NONROOT_SEND;
2742
2743 netlink_table_ungrab();
2744 }
2745
2746 static struct pernet_operations __net_initdata netlink_net_ops = {
2747 .init = netlink_net_init,
2748 .exit = netlink_net_exit,
2749 };
2750
2751 static inline u32 netlink_hash(const void *data, u32 len, u32 seed)
2752 {
2753 const struct netlink_sock *nlk = data;
2754 struct netlink_compare_arg arg;
2755
2756 netlink_compare_arg_init(&arg, sock_net(&nlk->sk), nlk->portid);
2757 return jhash2((u32 *)&arg, netlink_compare_arg_len / sizeof(u32), seed);
2758 }
2759
2760 static const struct rhashtable_params netlink_rhashtable_params = {
2761 .head_offset = offsetof(struct netlink_sock, node),
2762 .key_len = netlink_compare_arg_len,
2763 .obj_hashfn = netlink_hash,
2764 .obj_cmpfn = netlink_compare,
2765 .automatic_shrinking = true,
2766 };
2767
2768 static int __init netlink_proto_init(void)
2769 {
2770 int i;
2771 int err = proto_register(&netlink_proto, 0);
2772
2773 if (err != 0)
2774 goto out;
2775
2776 BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb));
2777
2778 nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);
2779 if (!nl_table)
2780 goto panic;
2781
2782 for (i = 0; i < MAX_LINKS; i++) {
2783 if (rhashtable_init(&nl_table[i].hash,
2784 &netlink_rhashtable_params) < 0) {
2785 while (--i > 0)
2786 rhashtable_destroy(&nl_table[i].hash);
2787 kfree(nl_table);
2788 goto panic;
2789 }
2790 }
2791
2792 netlink_add_usersock_entry();
2793
2794 sock_register(&netlink_family_ops);
2795 register_pernet_subsys(&netlink_net_ops);
2796 register_pernet_subsys(&netlink_tap_net_ops);
2797 /* The netlink device handler may be needed early. */
2798 rtnetlink_init();
2799 out:
2800 return err;
2801 panic:
2802 panic("netlink_init: Cannot allocate nl_table\n");
2803 }
2804
2805 core_initcall(netlink_proto_init);
Ubuntu Hirsute Linux kernel mirror