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