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