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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 void (*netlink_bind)(int group);
84 struct module *module;
85};
86
87struct listeners {
88 struct rcu_head rcu;
89 unsigned long masks[0];
90};
91
92#define NETLINK_KERNEL_SOCKET 0x1
93#define NETLINK_RECV_PKTINFO 0x2
94#define NETLINK_BROADCAST_SEND_ERROR 0x4
95#define NETLINK_RECV_NO_ENOBUFS 0x8
96
97static inline struct netlink_sock *nlk_sk(struct sock *sk)
98{
99 return container_of(sk, struct netlink_sock, sk);
100}
101
102static inline int netlink_is_kernel(struct sock *sk)
103{
104 return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET;
105}
106
107struct nl_pid_hash {
108 struct hlist_head *table;
109 unsigned long rehash_time;
110
111 unsigned int mask;
112 unsigned int shift;
113
114 unsigned int entries;
115 unsigned int max_shift;
116
117 u32 rnd;
118};
119
120struct netlink_table {
121 struct nl_pid_hash hash;
122 struct hlist_head mc_list;
123 struct listeners __rcu *listeners;
124 unsigned int nl_nonroot;
125 unsigned int groups;
126 struct mutex *cb_mutex;
127 struct module *module;
128 void (*bind)(int group);
129 int registered;
130};
131
132static struct netlink_table *nl_table;
133
134static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
135
136static int netlink_dump(struct sock *sk);
137
138static DEFINE_RWLOCK(nl_table_lock);
139static atomic_t nl_table_users = ATOMIC_INIT(0);
140
141static ATOMIC_NOTIFIER_HEAD(netlink_chain);
142
143static inline u32 netlink_group_mask(u32 group)
144{
145 return group ? 1 << (group - 1) : 0;
146}
147
148static inline struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid)
149{
150 return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask];
151}
152
153static void netlink_destroy_callback(struct netlink_callback *cb)
154{
155 kfree_skb(cb->skb);
156 kfree(cb);
157}
158
159static void netlink_consume_callback(struct netlink_callback *cb)
160{
161 consume_skb(cb->skb);
162 kfree(cb);
163}
164
165static void netlink_sock_destruct(struct sock *sk)
166{
167 struct netlink_sock *nlk = nlk_sk(sk);
168
169 if (nlk->cb) {
170 if (nlk->cb->done)
171 nlk->cb->done(nlk->cb);
172 netlink_destroy_callback(nlk->cb);
173 }
174
175 skb_queue_purge(&sk->sk_receive_queue);
176
177 if (!sock_flag(sk, SOCK_DEAD)) {
178 printk(KERN_ERR "Freeing alive netlink socket %p\n", sk);
179 return;
180 }
181
182 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
183 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
184 WARN_ON(nlk_sk(sk)->groups);
185}
186
187
188
189
190
191
192
193void netlink_table_grab(void)
194 __acquires(nl_table_lock)
195{
196 might_sleep();
197
198 write_lock_irq(&nl_table_lock);
199
200 if (atomic_read(&nl_table_users)) {
201 DECLARE_WAITQUEUE(wait, current);
202
203 add_wait_queue_exclusive(&nl_table_wait, &wait);
204 for (;;) {
205 set_current_state(TASK_UNINTERRUPTIBLE);
206 if (atomic_read(&nl_table_users) == 0)
207 break;
208 write_unlock_irq(&nl_table_lock);
209 schedule();
210 write_lock_irq(&nl_table_lock);
211 }
212
213 __set_current_state(TASK_RUNNING);
214 remove_wait_queue(&nl_table_wait, &wait);
215 }
216}
217
218void netlink_table_ungrab(void)
219 __releases(nl_table_lock)
220{
221 write_unlock_irq(&nl_table_lock);
222 wake_up(&nl_table_wait);
223}
224
225static inline void
226netlink_lock_table(void)
227{
228
229
230 read_lock(&nl_table_lock);
231 atomic_inc(&nl_table_users);
232 read_unlock(&nl_table_lock);
233}
234
235static inline void
236netlink_unlock_table(void)
237{
238 if (atomic_dec_and_test(&nl_table_users))
239 wake_up(&nl_table_wait);
240}
241
242static struct sock *netlink_lookup(struct net *net, int protocol, u32 pid)
243{
244 struct nl_pid_hash *hash = &nl_table[protocol].hash;
245 struct hlist_head *head;
246 struct sock *sk;
247 struct hlist_node *node;
248
249 read_lock(&nl_table_lock);
250 head = nl_pid_hashfn(hash, pid);
251 sk_for_each(sk, node, head) {
252 if (net_eq(sock_net(sk), net) && (nlk_sk(sk)->pid == pid)) {
253 sock_hold(sk);
254 goto found;
255 }
256 }
257 sk = NULL;
258found:
259 read_unlock(&nl_table_lock);
260 return sk;
261}
262
263static struct hlist_head *nl_pid_hash_zalloc(size_t size)
264{
265 if (size <= PAGE_SIZE)
266 return kzalloc(size, GFP_ATOMIC);
267 else
268 return (struct hlist_head *)
269 __get_free_pages(GFP_ATOMIC | __GFP_ZERO,
270 get_order(size));
271}
272
273static void nl_pid_hash_free(struct hlist_head *table, size_t size)
274{
275 if (size <= PAGE_SIZE)
276 kfree(table);
277 else
278 free_pages((unsigned long)table, get_order(size));
279}
280
281static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow)
282{
283 unsigned int omask, mask, shift;
284 size_t osize, size;
285 struct hlist_head *otable, *table;
286 int i;
287
288 omask = mask = hash->mask;
289 osize = size = (mask + 1) * sizeof(*table);
290 shift = hash->shift;
291
292 if (grow) {
293 if (++shift > hash->max_shift)
294 return 0;
295 mask = mask * 2 + 1;
296 size *= 2;
297 }
298
299 table = nl_pid_hash_zalloc(size);
300 if (!table)
301 return 0;
302
303 otable = hash->table;
304 hash->table = table;
305 hash->mask = mask;
306 hash->shift = shift;
307 get_random_bytes(&hash->rnd, sizeof(hash->rnd));
308
309 for (i = 0; i <= omask; i++) {
310 struct sock *sk;
311 struct hlist_node *node, *tmp;
312
313 sk_for_each_safe(sk, node, tmp, &otable[i])
314 __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid));
315 }
316
317 nl_pid_hash_free(otable, osize);
318 hash->rehash_time = jiffies + 10 * 60 * HZ;
319 return 1;
320}
321
322static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len)
323{
324 int avg = hash->entries >> hash->shift;
325
326 if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1))
327 return 1;
328
329 if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) {
330 nl_pid_hash_rehash(hash, 0);
331 return 1;
332 }
333
334 return 0;
335}
336
337static const struct proto_ops netlink_ops;
338
339static void
340netlink_update_listeners(struct sock *sk)
341{
342 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
343 struct hlist_node *node;
344 unsigned long mask;
345 unsigned int i;
346
347 for (i = 0; i < NLGRPLONGS(tbl->groups); i++) {
348 mask = 0;
349 sk_for_each_bound(sk, node, &tbl->mc_list) {
350 if (i < NLGRPLONGS(nlk_sk(sk)->ngroups))
351 mask |= nlk_sk(sk)->groups[i];
352 }
353 tbl->listeners->masks[i] = mask;
354 }
355
356
357}
358
359static int netlink_insert(struct sock *sk, struct net *net, u32 pid)
360{
361 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
362 struct hlist_head *head;
363 int err = -EADDRINUSE;
364 struct sock *osk;
365 struct hlist_node *node;
366 int len;
367
368 netlink_table_grab();
369 head = nl_pid_hashfn(hash, pid);
370 len = 0;
371 sk_for_each(osk, node, head) {
372 if (net_eq(sock_net(osk), net) && (nlk_sk(osk)->pid == pid))
373 break;
374 len++;
375 }
376 if (node)
377 goto err;
378
379 err = -EBUSY;
380 if (nlk_sk(sk)->pid)
381 goto err;
382
383 err = -ENOMEM;
384 if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX))
385 goto err;
386
387 if (len && nl_pid_hash_dilute(hash, len))
388 head = nl_pid_hashfn(hash, pid);
389 hash->entries++;
390 nlk_sk(sk)->pid = pid;
391 sk_add_node(sk, head);
392 err = 0;
393
394err:
395 netlink_table_ungrab();
396 return err;
397}
398
399static void netlink_remove(struct sock *sk)
400{
401 netlink_table_grab();
402 if (sk_del_node_init(sk))
403 nl_table[sk->sk_protocol].hash.entries--;
404 if (nlk_sk(sk)->subscriptions)
405 __sk_del_bind_node(sk);
406 netlink_table_ungrab();
407}
408
409static struct proto netlink_proto = {
410 .name = "NETLINK",
411 .owner = THIS_MODULE,
412 .obj_size = sizeof(struct netlink_sock),
413};
414
415static int __netlink_create(struct net *net, struct socket *sock,
416 struct mutex *cb_mutex, int protocol)
417{
418 struct sock *sk;
419 struct netlink_sock *nlk;
420
421 sock->ops = &netlink_ops;
422
423 sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto);
424 if (!sk)
425 return -ENOMEM;
426
427 sock_init_data(sock, sk);
428
429 nlk = nlk_sk(sk);
430 if (cb_mutex) {
431 nlk->cb_mutex = cb_mutex;
432 } else {
433 nlk->cb_mutex = &nlk->cb_def_mutex;
434 mutex_init(nlk->cb_mutex);
435 }
436 init_waitqueue_head(&nlk->wait);
437
438 sk->sk_destruct = netlink_sock_destruct;
439 sk->sk_protocol = protocol;
440 return 0;
441}
442
443static int netlink_create(struct net *net, struct socket *sock, int protocol,
444 int kern)
445{
446 struct module *module = NULL;
447 struct mutex *cb_mutex;
448 struct netlink_sock *nlk;
449 void (*bind)(int group);
450 int err = 0;
451
452 sock->state = SS_UNCONNECTED;
453
454 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
455 return -ESOCKTNOSUPPORT;
456
457 if (protocol < 0 || protocol >= MAX_LINKS)
458 return -EPROTONOSUPPORT;
459
460 netlink_lock_table();
461#ifdef CONFIG_MODULES
462 if (!nl_table[protocol].registered) {
463 netlink_unlock_table();
464 request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
465 netlink_lock_table();
466 }
467#endif
468 if (nl_table[protocol].registered &&
469 try_module_get(nl_table[protocol].module))
470 module = nl_table[protocol].module;
471 else
472 err = -EPROTONOSUPPORT;
473 cb_mutex = nl_table[protocol].cb_mutex;
474 bind = nl_table[protocol].bind;
475 netlink_unlock_table();
476
477 if (err < 0)
478 goto out;
479
480 err = __netlink_create(net, sock, cb_mutex, protocol);
481 if (err < 0)
482 goto out_module;
483
484 local_bh_disable();
485 sock_prot_inuse_add(net, &netlink_proto, 1);
486 local_bh_enable();
487
488 nlk = nlk_sk(sock->sk);
489 nlk->module = module;
490 nlk->netlink_bind = bind;
491out:
492 return err;
493
494out_module:
495 module_put(module);
496 goto out;
497}
498
499static int netlink_release(struct socket *sock)
500{
501 struct sock *sk = sock->sk;
502 struct netlink_sock *nlk;
503
504 if (!sk)
505 return 0;
506
507 netlink_remove(sk);
508 sock_orphan(sk);
509 nlk = nlk_sk(sk);
510
511
512
513
514
515
516 sock->sk = NULL;
517 wake_up_interruptible_all(&nlk->wait);
518
519 skb_queue_purge(&sk->sk_write_queue);
520
521 if (nlk->pid) {
522 struct netlink_notify n = {
523 .net = sock_net(sk),
524 .protocol = sk->sk_protocol,
525 .pid = nlk->pid,
526 };
527 atomic_notifier_call_chain(&netlink_chain,
528 NETLINK_URELEASE, &n);
529 }
530
531 module_put(nlk->module);
532
533 netlink_table_grab();
534 if (netlink_is_kernel(sk)) {
535 BUG_ON(nl_table[sk->sk_protocol].registered == 0);
536 if (--nl_table[sk->sk_protocol].registered == 0) {
537 kfree(nl_table[sk->sk_protocol].listeners);
538 nl_table[sk->sk_protocol].module = NULL;
539 nl_table[sk->sk_protocol].registered = 0;
540 }
541 } else if (nlk->subscriptions) {
542 netlink_update_listeners(sk);
543 }
544 netlink_table_ungrab();
545
546 kfree(nlk->groups);
547 nlk->groups = NULL;
548
549 local_bh_disable();
550 sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1);
551 local_bh_enable();
552 sock_put(sk);
553 return 0;
554}
555
556static int netlink_autobind(struct socket *sock)
557{
558 struct sock *sk = sock->sk;
559 struct net *net = sock_net(sk);
560 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
561 struct hlist_head *head;
562 struct sock *osk;
563 struct hlist_node *node;
564 s32 pid = task_tgid_vnr(current);
565 int err;
566 static s32 rover = -4097;
567
568retry:
569 cond_resched();
570 netlink_table_grab();
571 head = nl_pid_hashfn(hash, pid);
572 sk_for_each(osk, node, head) {
573 if (!net_eq(sock_net(osk), net))
574 continue;
575 if (nlk_sk(osk)->pid == pid) {
576
577 pid = rover--;
578 if (rover > -4097)
579 rover = -4097;
580 netlink_table_ungrab();
581 goto retry;
582 }
583 }
584 netlink_table_ungrab();
585
586 err = netlink_insert(sk, net, pid);
587 if (err == -EADDRINUSE)
588 goto retry;
589
590
591 if (err == -EBUSY)
592 err = 0;
593
594 return err;
595}
596
597static inline int netlink_capable(const struct socket *sock, unsigned int flag)
598{
599 return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) ||
600 capable(CAP_NET_ADMIN);
601}
602
603static void
604netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions)
605{
606 struct netlink_sock *nlk = nlk_sk(sk);
607
608 if (nlk->subscriptions && !subscriptions)
609 __sk_del_bind_node(sk);
610 else if (!nlk->subscriptions && subscriptions)
611 sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
612 nlk->subscriptions = subscriptions;
613}
614
615static int netlink_realloc_groups(struct sock *sk)
616{
617 struct netlink_sock *nlk = nlk_sk(sk);
618 unsigned int groups;
619 unsigned long *new_groups;
620 int err = 0;
621
622 netlink_table_grab();
623
624 groups = nl_table[sk->sk_protocol].groups;
625 if (!nl_table[sk->sk_protocol].registered) {
626 err = -ENOENT;
627 goto out_unlock;
628 }
629
630 if (nlk->ngroups >= groups)
631 goto out_unlock;
632
633 new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC);
634 if (new_groups == NULL) {
635 err = -ENOMEM;
636 goto out_unlock;
637 }
638 memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0,
639 NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups));
640
641 nlk->groups = new_groups;
642 nlk->ngroups = groups;
643 out_unlock:
644 netlink_table_ungrab();
645 return err;
646}
647
648static int netlink_bind(struct socket *sock, struct sockaddr *addr,
649 int addr_len)
650{
651 struct sock *sk = sock->sk;
652 struct net *net = sock_net(sk);
653 struct netlink_sock *nlk = nlk_sk(sk);
654 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
655 int err;
656
657 if (nladdr->nl_family != AF_NETLINK)
658 return -EINVAL;
659
660
661 if (nladdr->nl_groups) {
662 if (!netlink_capable(sock, NL_NONROOT_RECV))
663 return -EPERM;
664 err = netlink_realloc_groups(sk);
665 if (err)
666 return err;
667 }
668
669 if (nlk->pid) {
670 if (nladdr->nl_pid != nlk->pid)
671 return -EINVAL;
672 } else {
673 err = nladdr->nl_pid ?
674 netlink_insert(sk, net, nladdr->nl_pid) :
675 netlink_autobind(sock);
676 if (err)
677 return err;
678 }
679
680 if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
681 return 0;
682
683 netlink_table_grab();
684 netlink_update_subscriptions(sk, nlk->subscriptions +
685 hweight32(nladdr->nl_groups) -
686 hweight32(nlk->groups[0]));
687 nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups;
688 netlink_update_listeners(sk);
689 netlink_table_ungrab();
690
691 if (nlk->netlink_bind && nlk->groups[0]) {
692 int i;
693
694 for (i=0; i<nlk->ngroups; i++) {
695 if (test_bit(i, nlk->groups))
696 nlk->netlink_bind(i);
697 }
698 }
699
700 return 0;
701}
702
703static int netlink_connect(struct socket *sock, struct sockaddr *addr,
704 int alen, int flags)
705{
706 int err = 0;
707 struct sock *sk = sock->sk;
708 struct netlink_sock *nlk = nlk_sk(sk);
709 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
710
711 if (alen < sizeof(addr->sa_family))
712 return -EINVAL;
713
714 if (addr->sa_family == AF_UNSPEC) {
715 sk->sk_state = NETLINK_UNCONNECTED;
716 nlk->dst_pid = 0;
717 nlk->dst_group = 0;
718 return 0;
719 }
720 if (addr->sa_family != AF_NETLINK)
721 return -EINVAL;
722
723
724 if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND))
725 return -EPERM;
726
727 if (!nlk->pid)
728 err = netlink_autobind(sock);
729
730 if (err == 0) {
731 sk->sk_state = NETLINK_CONNECTED;
732 nlk->dst_pid = nladdr->nl_pid;
733 nlk->dst_group = ffs(nladdr->nl_groups);
734 }
735
736 return err;
737}
738
739static int netlink_getname(struct socket *sock, struct sockaddr *addr,
740 int *addr_len, int peer)
741{
742 struct sock *sk = sock->sk;
743 struct netlink_sock *nlk = nlk_sk(sk);
744 DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr);
745
746 nladdr->nl_family = AF_NETLINK;
747 nladdr->nl_pad = 0;
748 *addr_len = sizeof(*nladdr);
749
750 if (peer) {
751 nladdr->nl_pid = nlk->dst_pid;
752 nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
753 } else {
754 nladdr->nl_pid = nlk->pid;
755 nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
756 }
757 return 0;
758}
759
760static void netlink_overrun(struct sock *sk)
761{
762 struct netlink_sock *nlk = nlk_sk(sk);
763
764 if (!(nlk->flags & NETLINK_RECV_NO_ENOBUFS)) {
765 if (!test_and_set_bit(0, &nlk_sk(sk)->state)) {
766 sk->sk_err = ENOBUFS;
767 sk->sk_error_report(sk);
768 }
769 }
770 atomic_inc(&sk->sk_drops);
771}
772
773static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid)
774{
775 struct sock *sock;
776 struct netlink_sock *nlk;
777
778 sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, pid);
779 if (!sock)
780 return ERR_PTR(-ECONNREFUSED);
781
782
783 nlk = nlk_sk(sock);
784 if (sock->sk_state == NETLINK_CONNECTED &&
785 nlk->dst_pid != nlk_sk(ssk)->pid) {
786 sock_put(sock);
787 return ERR_PTR(-ECONNREFUSED);
788 }
789 return sock;
790}
791
792struct sock *netlink_getsockbyfilp(struct file *filp)
793{
794 struct inode *inode = filp->f_path.dentry->d_inode;
795 struct sock *sock;
796
797 if (!S_ISSOCK(inode->i_mode))
798 return ERR_PTR(-ENOTSOCK);
799
800 sock = SOCKET_I(inode)->sk;
801 if (sock->sk_family != AF_NETLINK)
802 return ERR_PTR(-EINVAL);
803
804 sock_hold(sock);
805 return sock;
806}
807
808
809
810
811
812
813
814
815
816
817
818int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
819 long *timeo, struct sock *ssk)
820{
821 struct netlink_sock *nlk;
822
823 nlk = nlk_sk(sk);
824
825 if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
826 test_bit(0, &nlk->state)) {
827 DECLARE_WAITQUEUE(wait, current);
828 if (!*timeo) {
829 if (!ssk || netlink_is_kernel(ssk))
830 netlink_overrun(sk);
831 sock_put(sk);
832 kfree_skb(skb);
833 return -EAGAIN;
834 }
835
836 __set_current_state(TASK_INTERRUPTIBLE);
837 add_wait_queue(&nlk->wait, &wait);
838
839 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
840 test_bit(0, &nlk->state)) &&
841 !sock_flag(sk, SOCK_DEAD))
842 *timeo = schedule_timeout(*timeo);
843
844 __set_current_state(TASK_RUNNING);
845 remove_wait_queue(&nlk->wait, &wait);
846 sock_put(sk);
847
848 if (signal_pending(current)) {
849 kfree_skb(skb);
850 return sock_intr_errno(*timeo);
851 }
852 return 1;
853 }
854 skb_set_owner_r(skb, sk);
855 return 0;
856}
857
858static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb)
859{
860 int len = skb->len;
861
862 skb_queue_tail(&sk->sk_receive_queue, skb);
863 sk->sk_data_ready(sk, len);
864 return len;
865}
866
867int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
868{
869 int len = __netlink_sendskb(sk, skb);
870
871 sock_put(sk);
872 return len;
873}
874
875void netlink_detachskb(struct sock *sk, struct sk_buff *skb)
876{
877 kfree_skb(skb);
878 sock_put(sk);
879}
880
881static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation)
882{
883 int delta;
884
885 skb_orphan(skb);
886
887 delta = skb->end - skb->tail;
888 if (delta * 2 < skb->truesize)
889 return skb;
890
891 if (skb_shared(skb)) {
892 struct sk_buff *nskb = skb_clone(skb, allocation);
893 if (!nskb)
894 return skb;
895 consume_skb(skb);
896 skb = nskb;
897 }
898
899 if (!pskb_expand_head(skb, 0, -delta, allocation))
900 skb->truesize -= delta;
901
902 return skb;
903}
904
905static void netlink_rcv_wake(struct sock *sk)
906{
907 struct netlink_sock *nlk = nlk_sk(sk);
908
909 if (skb_queue_empty(&sk->sk_receive_queue))
910 clear_bit(0, &nlk->state);
911 if (!test_bit(0, &nlk->state))
912 wake_up_interruptible(&nlk->wait);
913}
914
915static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb)
916{
917 int ret;
918 struct netlink_sock *nlk = nlk_sk(sk);
919
920 ret = -ECONNREFUSED;
921 if (nlk->netlink_rcv != NULL) {
922 ret = skb->len;
923 skb_set_owner_r(skb, sk);
924 nlk->netlink_rcv(skb);
925 consume_skb(skb);
926 } else {
927 kfree_skb(skb);
928 }
929 sock_put(sk);
930 return ret;
931}
932
933int netlink_unicast(struct sock *ssk, struct sk_buff *skb,
934 u32 pid, int nonblock)
935{
936 struct sock *sk;
937 int err;
938 long timeo;
939
940 skb = netlink_trim(skb, gfp_any());
941
942 timeo = sock_sndtimeo(ssk, nonblock);
943retry:
944 sk = netlink_getsockbypid(ssk, pid);
945 if (IS_ERR(sk)) {
946 kfree_skb(skb);
947 return PTR_ERR(sk);
948 }
949 if (netlink_is_kernel(sk))
950 return netlink_unicast_kernel(sk, skb);
951
952 if (sk_filter(sk, skb)) {
953 err = skb->len;
954 kfree_skb(skb);
955 sock_put(sk);
956 return err;
957 }
958
959 err = netlink_attachskb(sk, skb, &timeo, ssk);
960 if (err == 1)
961 goto retry;
962 if (err)
963 return err;
964
965 return netlink_sendskb(sk, skb);
966}
967EXPORT_SYMBOL(netlink_unicast);
968
969int netlink_has_listeners(struct sock *sk, unsigned int group)
970{
971 int res = 0;
972 struct listeners *listeners;
973
974 BUG_ON(!netlink_is_kernel(sk));
975
976 rcu_read_lock();
977 listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners);
978
979 if (group - 1 < nl_table[sk->sk_protocol].groups)
980 res = test_bit(group - 1, listeners->masks);
981
982 rcu_read_unlock();
983
984 return res;
985}
986EXPORT_SYMBOL_GPL(netlink_has_listeners);
987
988static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb)
989{
990 struct netlink_sock *nlk = nlk_sk(sk);
991
992 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
993 !test_bit(0, &nlk->state)) {
994 skb_set_owner_r(skb, sk);
995 __netlink_sendskb(sk, skb);
996 return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1);
997 }
998 return -1;
999}
1000
1001struct netlink_broadcast_data {
1002 struct sock *exclude_sk;
1003 struct net *net;
1004 u32 pid;
1005 u32 group;
1006 int failure;
1007 int delivery_failure;
1008 int congested;
1009 int delivered;
1010 gfp_t allocation;
1011 struct sk_buff *skb, *skb2;
1012 int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data);
1013 void *tx_data;
1014};
1015
1016static int do_one_broadcast(struct sock *sk,
1017 struct netlink_broadcast_data *p)
1018{
1019 struct netlink_sock *nlk = nlk_sk(sk);
1020 int val;
1021
1022 if (p->exclude_sk == sk)
1023 goto out;
1024
1025 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
1026 !test_bit(p->group - 1, nlk->groups))
1027 goto out;
1028
1029 if (!net_eq(sock_net(sk), p->net))
1030 goto out;
1031
1032 if (p->failure) {
1033 netlink_overrun(sk);
1034 goto out;
1035 }
1036
1037 sock_hold(sk);
1038 if (p->skb2 == NULL) {
1039 if (skb_shared(p->skb)) {
1040 p->skb2 = skb_clone(p->skb, p->allocation);
1041 } else {
1042 p->skb2 = skb_get(p->skb);
1043
1044
1045
1046
1047 skb_orphan(p->skb2);
1048 }
1049 }
1050 if (p->skb2 == NULL) {
1051 netlink_overrun(sk);
1052
1053 p->failure = 1;
1054 if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR)
1055 p->delivery_failure = 1;
1056 } else if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) {
1057 kfree_skb(p->skb2);
1058 p->skb2 = NULL;
1059 } else if (sk_filter(sk, p->skb2)) {
1060 kfree_skb(p->skb2);
1061 p->skb2 = NULL;
1062 } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) {
1063 netlink_overrun(sk);
1064 if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR)
1065 p->delivery_failure = 1;
1066 } else {
1067 p->congested |= val;
1068 p->delivered = 1;
1069 p->skb2 = NULL;
1070 }
1071 sock_put(sk);
1072
1073out:
1074 return 0;
1075}
1076
1077int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 pid,
1078 u32 group, gfp_t allocation,
1079 int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
1080 void *filter_data)
1081{
1082 struct net *net = sock_net(ssk);
1083 struct netlink_broadcast_data info;
1084 struct hlist_node *node;
1085 struct sock *sk;
1086
1087 skb = netlink_trim(skb, allocation);
1088
1089 info.exclude_sk = ssk;
1090 info.net = net;
1091 info.pid = pid;
1092 info.group = group;
1093 info.failure = 0;
1094 info.delivery_failure = 0;
1095 info.congested = 0;
1096 info.delivered = 0;
1097 info.allocation = allocation;
1098 info.skb = skb;
1099 info.skb2 = NULL;
1100 info.tx_filter = filter;
1101 info.tx_data = filter_data;
1102
1103
1104
1105 netlink_lock_table();
1106
1107 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
1108 do_one_broadcast(sk, &info);
1109
1110 consume_skb(skb);
1111
1112 netlink_unlock_table();
1113
1114 if (info.delivery_failure) {
1115 kfree_skb(info.skb2);
1116 return -ENOBUFS;
1117 }
1118 consume_skb(info.skb2);
1119
1120 if (info.delivered) {
1121 if (info.congested && (allocation & __GFP_WAIT))
1122 yield();
1123 return 0;
1124 }
1125 return -ESRCH;
1126}
1127EXPORT_SYMBOL(netlink_broadcast_filtered);
1128
1129int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
1130 u32 group, gfp_t allocation)
1131{
1132 return netlink_broadcast_filtered(ssk, skb, pid, group, allocation,
1133 NULL, NULL);
1134}
1135EXPORT_SYMBOL(netlink_broadcast);
1136
1137struct netlink_set_err_data {
1138 struct sock *exclude_sk;
1139 u32 pid;
1140 u32 group;
1141 int code;
1142};
1143
1144static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p)
1145{
1146 struct netlink_sock *nlk = nlk_sk(sk);
1147 int ret = 0;
1148
1149 if (sk == p->exclude_sk)
1150 goto out;
1151
1152 if (!net_eq(sock_net(sk), sock_net(p->exclude_sk)))
1153 goto out;
1154
1155 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
1156 !test_bit(p->group - 1, nlk->groups))
1157 goto out;
1158
1159 if (p->code == ENOBUFS && nlk->flags & NETLINK_RECV_NO_ENOBUFS) {
1160 ret = 1;
1161 goto out;
1162 }
1163
1164 sk->sk_err = p->code;
1165 sk->sk_error_report(sk);
1166out:
1167 return ret;
1168}
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180int netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code)
1181{
1182 struct netlink_set_err_data info;
1183 struct hlist_node *node;
1184 struct sock *sk;
1185 int ret = 0;
1186
1187 info.exclude_sk = ssk;
1188 info.pid = pid;
1189 info.group = group;
1190
1191 info.code = -code;
1192
1193 read_lock(&nl_table_lock);
1194
1195 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
1196 ret += do_one_set_err(sk, &info);
1197
1198 read_unlock(&nl_table_lock);
1199 return ret;
1200}
1201EXPORT_SYMBOL(netlink_set_err);
1202
1203
1204static void netlink_update_socket_mc(struct netlink_sock *nlk,
1205 unsigned int group,
1206 int is_new)
1207{
1208 int old, new = !!is_new, subscriptions;
1209
1210 old = test_bit(group - 1, nlk->groups);
1211 subscriptions = nlk->subscriptions - old + new;
1212 if (new)
1213 __set_bit(group - 1, nlk->groups);
1214 else
1215 __clear_bit(group - 1, nlk->groups);
1216 netlink_update_subscriptions(&nlk->sk, subscriptions);
1217 netlink_update_listeners(&nlk->sk);
1218}
1219
1220static int netlink_setsockopt(struct socket *sock, int level, int optname,
1221 char __user *optval, unsigned int optlen)
1222{
1223 struct sock *sk = sock->sk;
1224 struct netlink_sock *nlk = nlk_sk(sk);
1225 unsigned int val = 0;
1226 int err;
1227
1228 if (level != SOL_NETLINK)
1229 return -ENOPROTOOPT;
1230
1231 if (optlen >= sizeof(int) &&
1232 get_user(val, (unsigned int __user *)optval))
1233 return -EFAULT;
1234
1235 switch (optname) {
1236 case NETLINK_PKTINFO:
1237 if (val)
1238 nlk->flags |= NETLINK_RECV_PKTINFO;
1239 else
1240 nlk->flags &= ~NETLINK_RECV_PKTINFO;
1241 err = 0;
1242 break;
1243 case NETLINK_ADD_MEMBERSHIP:
1244 case NETLINK_DROP_MEMBERSHIP: {
1245 if (!netlink_capable(sock, NL_NONROOT_RECV))
1246 return -EPERM;
1247 err = netlink_realloc_groups(sk);
1248 if (err)
1249 return err;
1250 if (!val || val - 1 >= nlk->ngroups)
1251 return -EINVAL;
1252 netlink_table_grab();
1253 netlink_update_socket_mc(nlk, val,
1254 optname == NETLINK_ADD_MEMBERSHIP);
1255 netlink_table_ungrab();
1256
1257 if (nlk->netlink_bind)
1258 nlk->netlink_bind(val);
1259
1260 err = 0;
1261 break;
1262 }
1263 case NETLINK_BROADCAST_ERROR:
1264 if (val)
1265 nlk->flags |= NETLINK_BROADCAST_SEND_ERROR;
1266 else
1267 nlk->flags &= ~NETLINK_BROADCAST_SEND_ERROR;
1268 err = 0;
1269 break;
1270 case NETLINK_NO_ENOBUFS:
1271 if (val) {
1272 nlk->flags |= NETLINK_RECV_NO_ENOBUFS;
1273 clear_bit(0, &nlk->state);
1274 wake_up_interruptible(&nlk->wait);
1275 } else {
1276 nlk->flags &= ~NETLINK_RECV_NO_ENOBUFS;
1277 }
1278 err = 0;
1279 break;
1280 default:
1281 err = -ENOPROTOOPT;
1282 }
1283 return err;
1284}
1285
1286static int netlink_getsockopt(struct socket *sock, int level, int optname,
1287 char __user *optval, int __user *optlen)
1288{
1289 struct sock *sk = sock->sk;
1290 struct netlink_sock *nlk = nlk_sk(sk);
1291 int len, val, err;
1292
1293 if (level != SOL_NETLINK)
1294 return -ENOPROTOOPT;
1295
1296 if (get_user(len, optlen))
1297 return -EFAULT;
1298 if (len < 0)
1299 return -EINVAL;
1300
1301 switch (optname) {
1302 case NETLINK_PKTINFO:
1303 if (len < sizeof(int))
1304 return -EINVAL;
1305 len = sizeof(int);
1306 val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0;
1307 if (put_user(len, optlen) ||
1308 put_user(val, optval))
1309 return -EFAULT;
1310 err = 0;
1311 break;
1312 case NETLINK_BROADCAST_ERROR:
1313 if (len < sizeof(int))
1314 return -EINVAL;
1315 len = sizeof(int);
1316 val = nlk->flags & NETLINK_BROADCAST_SEND_ERROR ? 1 : 0;
1317 if (put_user(len, optlen) ||
1318 put_user(val, optval))
1319 return -EFAULT;
1320 err = 0;
1321 break;
1322 case NETLINK_NO_ENOBUFS:
1323 if (len < sizeof(int))
1324 return -EINVAL;
1325 len = sizeof(int);
1326 val = nlk->flags & NETLINK_RECV_NO_ENOBUFS ? 1 : 0;
1327 if (put_user(len, optlen) ||
1328 put_user(val, optval))
1329 return -EFAULT;
1330 err = 0;
1331 break;
1332 default:
1333 err = -ENOPROTOOPT;
1334 }
1335 return err;
1336}
1337
1338static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
1339{
1340 struct nl_pktinfo info;
1341
1342 info.group = NETLINK_CB(skb).dst_group;
1343 put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info);
1344}
1345
1346static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
1347 struct msghdr *msg, size_t len)
1348{
1349 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1350 struct sock *sk = sock->sk;
1351 struct netlink_sock *nlk = nlk_sk(sk);
1352 struct sockaddr_nl *addr = msg->msg_name;
1353 u32 dst_pid;
1354 u32 dst_group;
1355 struct sk_buff *skb;
1356 int err;
1357 struct scm_cookie scm;
1358
1359 if (msg->msg_flags&MSG_OOB)
1360 return -EOPNOTSUPP;
1361
1362 if (NULL == siocb->scm)
1363 siocb->scm = &scm;
1364
1365 err = scm_send(sock, msg, siocb->scm, true);
1366 if (err < 0)
1367 return err;
1368
1369 if (msg->msg_namelen) {
1370 err = -EINVAL;
1371 if (addr->nl_family != AF_NETLINK)
1372 goto out;
1373 dst_pid = addr->nl_pid;
1374 dst_group = ffs(addr->nl_groups);
1375 err = -EPERM;
1376 if ((dst_group || dst_pid) &&
1377 !netlink_capable(sock, NL_NONROOT_SEND))
1378 goto out;
1379 } else {
1380 dst_pid = nlk->dst_pid;
1381 dst_group = nlk->dst_group;
1382 }
1383
1384 if (!nlk->pid) {
1385 err = netlink_autobind(sock);
1386 if (err)
1387 goto out;
1388 }
1389
1390 err = -EMSGSIZE;
1391 if (len > sk->sk_sndbuf - 32)
1392 goto out;
1393 err = -ENOBUFS;
1394 skb = alloc_skb(len, GFP_KERNEL);
1395 if (skb == NULL)
1396 goto out;
1397
1398 NETLINK_CB(skb).pid = nlk->pid;
1399 NETLINK_CB(skb).dst_group = dst_group;
1400 memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1401
1402 err = -EFAULT;
1403 if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
1404 kfree_skb(skb);
1405 goto out;
1406 }
1407
1408 err = security_netlink_send(sk, skb);
1409 if (err) {
1410 kfree_skb(skb);
1411 goto out;
1412 }
1413
1414 if (dst_group) {
1415 atomic_inc(&skb->users);
1416 netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL);
1417 }
1418 err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT);
1419
1420out:
1421 scm_destroy(siocb->scm);
1422 return err;
1423}
1424
1425static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
1426 struct msghdr *msg, size_t len,
1427 int flags)
1428{
1429 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1430 struct scm_cookie scm;
1431 struct sock *sk = sock->sk;
1432 struct netlink_sock *nlk = nlk_sk(sk);
1433 int noblock = flags&MSG_DONTWAIT;
1434 size_t copied;
1435 struct sk_buff *skb, *data_skb;
1436 int err, ret;
1437
1438 if (flags&MSG_OOB)
1439 return -EOPNOTSUPP;
1440
1441 copied = 0;
1442
1443 skb = skb_recv_datagram(sk, flags, noblock, &err);
1444 if (skb == NULL)
1445 goto out;
1446
1447 data_skb = skb;
1448
1449#ifdef CONFIG_COMPAT_NETLINK_MESSAGES
1450 if (unlikely(skb_shinfo(skb)->frag_list)) {
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461 if (flags & MSG_CMSG_COMPAT)
1462 data_skb = skb_shinfo(skb)->frag_list;
1463 }
1464#endif
1465
1466 msg->msg_namelen = 0;
1467
1468 copied = data_skb->len;
1469 if (len < copied) {
1470 msg->msg_flags |= MSG_TRUNC;
1471 copied = len;
1472 }
1473
1474 skb_reset_transport_header(data_skb);
1475 err = skb_copy_datagram_iovec(data_skb, 0, msg->msg_iov, copied);
1476
1477 if (msg->msg_name) {
1478 struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name;
1479 addr->nl_family = AF_NETLINK;
1480 addr->nl_pad = 0;
1481 addr->nl_pid = NETLINK_CB(skb).pid;
1482 addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group);
1483 msg->msg_namelen = sizeof(*addr);
1484 }
1485
1486 if (nlk->flags & NETLINK_RECV_PKTINFO)
1487 netlink_cmsg_recv_pktinfo(msg, skb);
1488
1489 if (NULL == siocb->scm) {
1490 memset(&scm, 0, sizeof(scm));
1491 siocb->scm = &scm;
1492 }
1493 siocb->scm->creds = *NETLINK_CREDS(skb);
1494 if (flags & MSG_TRUNC)
1495 copied = data_skb->len;
1496
1497 skb_free_datagram(sk, skb);
1498
1499 if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) {
1500 ret = netlink_dump(sk);
1501 if (ret) {
1502 sk->sk_err = ret;
1503 sk->sk_error_report(sk);
1504 }
1505 }
1506
1507 scm_recv(sock, msg, siocb->scm, flags);
1508out:
1509 netlink_rcv_wake(sk);
1510 return err ? : copied;
1511}
1512
1513static void netlink_data_ready(struct sock *sk, int len)
1514{
1515 BUG();
1516}
1517
1518
1519
1520
1521
1522
1523
1524struct sock *
1525netlink_kernel_create(struct net *net, int unit,
1526 struct module *module,
1527 struct netlink_kernel_cfg *cfg)
1528{
1529 struct socket *sock;
1530 struct sock *sk;
1531 struct netlink_sock *nlk;
1532 struct listeners *listeners = NULL;
1533 struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL;
1534 unsigned int groups;
1535
1536 BUG_ON(!nl_table);
1537
1538 if (unit < 0 || unit >= MAX_LINKS)
1539 return NULL;
1540
1541 if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
1542 return NULL;
1543
1544
1545
1546
1547
1548
1549
1550 if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0)
1551 goto out_sock_release_nosk;
1552
1553 sk = sock->sk;
1554 sk_change_net(sk, net);
1555
1556 if (!cfg || cfg->groups < 32)
1557 groups = 32;
1558 else
1559 groups = cfg->groups;
1560
1561 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
1562 if (!listeners)
1563 goto out_sock_release;
1564
1565 sk->sk_data_ready = netlink_data_ready;
1566 if (cfg && cfg->input)
1567 nlk_sk(sk)->netlink_rcv = cfg->input;
1568
1569 if (netlink_insert(sk, net, 0))
1570 goto out_sock_release;
1571
1572 nlk = nlk_sk(sk);
1573 nlk->flags |= NETLINK_KERNEL_SOCKET;
1574
1575 netlink_table_grab();
1576 if (!nl_table[unit].registered) {
1577 nl_table[unit].groups = groups;
1578 rcu_assign_pointer(nl_table[unit].listeners, listeners);
1579 nl_table[unit].cb_mutex = cb_mutex;
1580 nl_table[unit].module = module;
1581 nl_table[unit].bind = cfg ? cfg->bind : NULL;
1582 nl_table[unit].registered = 1;
1583 } else {
1584 kfree(listeners);
1585 nl_table[unit].registered++;
1586 }
1587 netlink_table_ungrab();
1588 return sk;
1589
1590out_sock_release:
1591 kfree(listeners);
1592 netlink_kernel_release(sk);
1593 return NULL;
1594
1595out_sock_release_nosk:
1596 sock_release(sock);
1597 return NULL;
1598}
1599EXPORT_SYMBOL(netlink_kernel_create);
1600
1601
1602void
1603netlink_kernel_release(struct sock *sk)
1604{
1605 sk_release_kernel(sk);
1606}
1607EXPORT_SYMBOL(netlink_kernel_release);
1608
1609int __netlink_change_ngroups(struct sock *sk, unsigned int groups)
1610{
1611 struct listeners *new, *old;
1612 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
1613
1614 if (groups < 32)
1615 groups = 32;
1616
1617 if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) {
1618 new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC);
1619 if (!new)
1620 return -ENOMEM;
1621 old = rcu_dereference_protected(tbl->listeners, 1);
1622 memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups));
1623 rcu_assign_pointer(tbl->listeners, new);
1624
1625 kfree_rcu(old, rcu);
1626 }
1627 tbl->groups = groups;
1628
1629 return 0;
1630}
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644int netlink_change_ngroups(struct sock *sk, unsigned int groups)
1645{
1646 int err;
1647
1648 netlink_table_grab();
1649 err = __netlink_change_ngroups(sk, groups);
1650 netlink_table_ungrab();
1651
1652 return err;
1653}
1654
1655void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
1656{
1657 struct sock *sk;
1658 struct hlist_node *node;
1659 struct netlink_table *tbl = &nl_table[ksk->sk_protocol];
1660
1661 sk_for_each_bound(sk, node, &tbl->mc_list)
1662 netlink_update_socket_mc(nlk_sk(sk), group, 0);
1663}
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673void netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
1674{
1675 netlink_table_grab();
1676 __netlink_clear_multicast_users(ksk, group);
1677 netlink_table_ungrab();
1678}
1679
1680void netlink_set_nonroot(int protocol, unsigned int flags)
1681{
1682 if ((unsigned int)protocol < MAX_LINKS)
1683 nl_table[protocol].nl_nonroot = flags;
1684}
1685EXPORT_SYMBOL(netlink_set_nonroot);
1686
1687struct nlmsghdr *
1688__nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, int type, int len, int flags)
1689{
1690 struct nlmsghdr *nlh;
1691 int size = NLMSG_LENGTH(len);
1692
1693 nlh = (struct nlmsghdr*)skb_put(skb, NLMSG_ALIGN(size));
1694 nlh->nlmsg_type = type;
1695 nlh->nlmsg_len = size;
1696 nlh->nlmsg_flags = flags;
1697 nlh->nlmsg_pid = pid;
1698 nlh->nlmsg_seq = seq;
1699 if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0)
1700 memset(NLMSG_DATA(nlh) + len, 0, NLMSG_ALIGN(size) - size);
1701 return nlh;
1702}
1703EXPORT_SYMBOL(__nlmsg_put);
1704
1705
1706
1707
1708
1709
1710static int netlink_dump(struct sock *sk)
1711{
1712 struct netlink_sock *nlk = nlk_sk(sk);
1713 struct netlink_callback *cb;
1714 struct sk_buff *skb = NULL;
1715 struct nlmsghdr *nlh;
1716 int len, err = -ENOBUFS;
1717 int alloc_size;
1718
1719 mutex_lock(nlk->cb_mutex);
1720
1721 cb = nlk->cb;
1722 if (cb == NULL) {
1723 err = -EINVAL;
1724 goto errout_skb;
1725 }
1726
1727 alloc_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE);
1728
1729 skb = sock_rmalloc(sk, alloc_size, 0, GFP_KERNEL);
1730 if (!skb)
1731 goto errout_skb;
1732
1733 len = cb->dump(skb, cb);
1734
1735 if (len > 0) {
1736 mutex_unlock(nlk->cb_mutex);
1737
1738 if (sk_filter(sk, skb))
1739 kfree_skb(skb);
1740 else
1741 __netlink_sendskb(sk, skb);
1742 return 0;
1743 }
1744
1745 nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI);
1746 if (!nlh)
1747 goto errout_skb;
1748
1749 nl_dump_check_consistent(cb, nlh);
1750
1751 memcpy(nlmsg_data(nlh), &len, sizeof(len));
1752
1753 if (sk_filter(sk, skb))
1754 kfree_skb(skb);
1755 else
1756 __netlink_sendskb(sk, skb);
1757
1758 if (cb->done)
1759 cb->done(cb);
1760 nlk->cb = NULL;
1761 mutex_unlock(nlk->cb_mutex);
1762
1763 netlink_consume_callback(cb);
1764 return 0;
1765
1766errout_skb:
1767 mutex_unlock(nlk->cb_mutex);
1768 kfree_skb(skb);
1769 return err;
1770}
1771
1772int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
1773 const struct nlmsghdr *nlh,
1774 struct netlink_dump_control *control)
1775{
1776 struct netlink_callback *cb;
1777 struct sock *sk;
1778 struct netlink_sock *nlk;
1779 int ret;
1780
1781 cb = kzalloc(sizeof(*cb), GFP_KERNEL);
1782 if (cb == NULL)
1783 return -ENOBUFS;
1784
1785 cb->dump = control->dump;
1786 cb->done = control->done;
1787 cb->nlh = nlh;
1788 cb->data = control->data;
1789 cb->min_dump_alloc = control->min_dump_alloc;
1790 atomic_inc(&skb->users);
1791 cb->skb = skb;
1792
1793 sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).pid);
1794 if (sk == NULL) {
1795 netlink_destroy_callback(cb);
1796 return -ECONNREFUSED;
1797 }
1798 nlk = nlk_sk(sk);
1799
1800 mutex_lock(nlk->cb_mutex);
1801 if (nlk->cb) {
1802 mutex_unlock(nlk->cb_mutex);
1803 netlink_destroy_callback(cb);
1804 sock_put(sk);
1805 return -EBUSY;
1806 }
1807 nlk->cb = cb;
1808 mutex_unlock(nlk->cb_mutex);
1809
1810 ret = netlink_dump(sk);
1811
1812 sock_put(sk);
1813
1814 if (ret)
1815 return ret;
1816
1817
1818
1819
1820 return -EINTR;
1821}
1822EXPORT_SYMBOL(netlink_dump_start);
1823
1824void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
1825{
1826 struct sk_buff *skb;
1827 struct nlmsghdr *rep;
1828 struct nlmsgerr *errmsg;
1829 size_t payload = sizeof(*errmsg);
1830
1831
1832 if (err)
1833 payload += nlmsg_len(nlh);
1834
1835 skb = nlmsg_new(payload, GFP_KERNEL);
1836 if (!skb) {
1837 struct sock *sk;
1838
1839 sk = netlink_lookup(sock_net(in_skb->sk),
1840 in_skb->sk->sk_protocol,
1841 NETLINK_CB(in_skb).pid);
1842 if (sk) {
1843 sk->sk_err = ENOBUFS;
1844 sk->sk_error_report(sk);
1845 sock_put(sk);
1846 }
1847 return;
1848 }
1849
1850 rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
1851 NLMSG_ERROR, payload, 0);
1852 errmsg = nlmsg_data(rep);
1853 errmsg->error = err;
1854 memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh));
1855 netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
1856}
1857EXPORT_SYMBOL(netlink_ack);
1858
1859int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
1860 struct nlmsghdr *))
1861{
1862 struct nlmsghdr *nlh;
1863 int err;
1864
1865 while (skb->len >= nlmsg_total_size(0)) {
1866 int msglen;
1867
1868 nlh = nlmsg_hdr(skb);
1869 err = 0;
1870
1871 if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
1872 return 0;
1873
1874
1875 if (!(nlh->nlmsg_flags & NLM_F_REQUEST))
1876 goto ack;
1877
1878
1879 if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
1880 goto ack;
1881
1882 err = cb(skb, nlh);
1883 if (err == -EINTR)
1884 goto skip;
1885
1886ack:
1887 if (nlh->nlmsg_flags & NLM_F_ACK || err)
1888 netlink_ack(skb, nlh, err);
1889
1890skip:
1891 msglen = NLMSG_ALIGN(nlh->nlmsg_len);
1892 if (msglen > skb->len)
1893 msglen = skb->len;
1894 skb_pull(skb, msglen);
1895 }
1896
1897 return 0;
1898}
1899EXPORT_SYMBOL(netlink_rcv_skb);
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid,
1911 unsigned int group, int report, gfp_t flags)
1912{
1913 int err = 0;
1914
1915 if (group) {
1916 int exclude_pid = 0;
1917
1918 if (report) {
1919 atomic_inc(&skb->users);
1920 exclude_pid = pid;
1921 }
1922
1923
1924
1925 err = nlmsg_multicast(sk, skb, exclude_pid, group, flags);
1926 }
1927
1928 if (report) {
1929 int err2;
1930
1931 err2 = nlmsg_unicast(sk, skb, pid);
1932 if (!err || err == -ESRCH)
1933 err = err2;
1934 }
1935
1936 return err;
1937}
1938EXPORT_SYMBOL(nlmsg_notify);
1939
1940#ifdef CONFIG_PROC_FS
1941struct nl_seq_iter {
1942 struct seq_net_private p;
1943 int link;
1944 int hash_idx;
1945};
1946
1947static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos)
1948{
1949 struct nl_seq_iter *iter = seq->private;
1950 int i, j;
1951 struct sock *s;
1952 struct hlist_node *node;
1953 loff_t off = 0;
1954
1955 for (i = 0; i < MAX_LINKS; i++) {
1956 struct nl_pid_hash *hash = &nl_table[i].hash;
1957
1958 for (j = 0; j <= hash->mask; j++) {
1959 sk_for_each(s, node, &hash->table[j]) {
1960 if (sock_net(s) != seq_file_net(seq))
1961 continue;
1962 if (off == pos) {
1963 iter->link = i;
1964 iter->hash_idx = j;
1965 return s;
1966 }
1967 ++off;
1968 }
1969 }
1970 }
1971 return NULL;
1972}
1973
1974static void *netlink_seq_start(struct seq_file *seq, loff_t *pos)
1975 __acquires(nl_table_lock)
1976{
1977 read_lock(&nl_table_lock);
1978 return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN;
1979}
1980
1981static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1982{
1983 struct sock *s;
1984 struct nl_seq_iter *iter;
1985 int i, j;
1986
1987 ++*pos;
1988
1989 if (v == SEQ_START_TOKEN)
1990 return netlink_seq_socket_idx(seq, 0);
1991
1992 iter = seq->private;
1993 s = v;
1994 do {
1995 s = sk_next(s);
1996 } while (s && sock_net(s) != seq_file_net(seq));
1997 if (s)
1998 return s;
1999
2000 i = iter->link;
2001 j = iter->hash_idx + 1;
2002
2003 do {
2004 struct nl_pid_hash *hash = &nl_table[i].hash;
2005
2006 for (; j <= hash->mask; j++) {
2007 s = sk_head(&hash->table[j]);
2008 while (s && sock_net(s) != seq_file_net(seq))
2009 s = sk_next(s);
2010 if (s) {
2011 iter->link = i;
2012 iter->hash_idx = j;
2013 return s;
2014 }
2015 }
2016
2017 j = 0;
2018 } while (++i < MAX_LINKS);
2019
2020 return NULL;
2021}
2022
2023static void netlink_seq_stop(struct seq_file *seq, void *v)
2024 __releases(nl_table_lock)
2025{
2026 read_unlock(&nl_table_lock);
2027}
2028
2029
2030static int netlink_seq_show(struct seq_file *seq, void *v)
2031{
2032 if (v == SEQ_START_TOKEN) {
2033 seq_puts(seq,
2034 "sk Eth Pid Groups "
2035 "Rmem Wmem Dump Locks Drops Inode\n");
2036 } else {
2037 struct sock *s = v;
2038 struct netlink_sock *nlk = nlk_sk(s);
2039
2040 seq_printf(seq, "%pK %-3d %-6d %08x %-8d %-8d %pK %-8d %-8d %-8lu\n",
2041 s,
2042 s->sk_protocol,
2043 nlk->pid,
2044 nlk->groups ? (u32)nlk->groups[0] : 0,
2045 sk_rmem_alloc_get(s),
2046 sk_wmem_alloc_get(s),
2047 nlk->cb,
2048 atomic_read(&s->sk_refcnt),
2049 atomic_read(&s->sk_drops),
2050 sock_i_ino(s)
2051 );
2052
2053 }
2054 return 0;
2055}
2056
2057static const struct seq_operations netlink_seq_ops = {
2058 .start = netlink_seq_start,
2059 .next = netlink_seq_next,
2060 .stop = netlink_seq_stop,
2061 .show = netlink_seq_show,
2062};
2063
2064
2065static int netlink_seq_open(struct inode *inode, struct file *file)
2066{
2067 return seq_open_net(inode, file, &netlink_seq_ops,
2068 sizeof(struct nl_seq_iter));
2069}
2070
2071static const struct file_operations netlink_seq_fops = {
2072 .owner = THIS_MODULE,
2073 .open = netlink_seq_open,
2074 .read = seq_read,
2075 .llseek = seq_lseek,
2076 .release = seq_release_net,
2077};
2078
2079#endif
2080
2081int netlink_register_notifier(struct notifier_block *nb)
2082{
2083 return atomic_notifier_chain_register(&netlink_chain, nb);
2084}
2085EXPORT_SYMBOL(netlink_register_notifier);
2086
2087int netlink_unregister_notifier(struct notifier_block *nb)
2088{
2089 return atomic_notifier_chain_unregister(&netlink_chain, nb);
2090}
2091EXPORT_SYMBOL(netlink_unregister_notifier);
2092
2093static const struct proto_ops netlink_ops = {
2094 .family = PF_NETLINK,
2095 .owner = THIS_MODULE,
2096 .release = netlink_release,
2097 .bind = netlink_bind,
2098 .connect = netlink_connect,
2099 .socketpair = sock_no_socketpair,
2100 .accept = sock_no_accept,
2101 .getname = netlink_getname,
2102 .poll = datagram_poll,
2103 .ioctl = sock_no_ioctl,
2104 .listen = sock_no_listen,
2105 .shutdown = sock_no_shutdown,
2106 .setsockopt = netlink_setsockopt,
2107 .getsockopt = netlink_getsockopt,
2108 .sendmsg = netlink_sendmsg,
2109 .recvmsg = netlink_recvmsg,
2110 .mmap = sock_no_mmap,
2111 .sendpage = sock_no_sendpage,
2112};
2113
2114static const struct net_proto_family netlink_family_ops = {
2115 .family = PF_NETLINK,
2116 .create = netlink_create,
2117 .owner = THIS_MODULE,
2118};
2119
2120static int __net_init netlink_net_init(struct net *net)
2121{
2122#ifdef CONFIG_PROC_FS
2123 if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops))
2124 return -ENOMEM;
2125#endif
2126 return 0;
2127}
2128
2129static void __net_exit netlink_net_exit(struct net *net)
2130{
2131#ifdef CONFIG_PROC_FS
2132 proc_net_remove(net, "netlink");
2133#endif
2134}
2135
2136static void __init netlink_add_usersock_entry(void)
2137{
2138 struct listeners *listeners;
2139 int groups = 32;
2140
2141 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
2142 if (!listeners)
2143 panic("netlink_add_usersock_entry: Cannot allocate listeners\n");
2144
2145 netlink_table_grab();
2146
2147 nl_table[NETLINK_USERSOCK].groups = groups;
2148 rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners);
2149 nl_table[NETLINK_USERSOCK].module = THIS_MODULE;
2150 nl_table[NETLINK_USERSOCK].registered = 1;
2151 nl_table[NETLINK_USERSOCK].nl_nonroot = NL_NONROOT_SEND;
2152
2153 netlink_table_ungrab();
2154}
2155
2156static struct pernet_operations __net_initdata netlink_net_ops = {
2157 .init = netlink_net_init,
2158 .exit = netlink_net_exit,
2159};
2160
2161static int __init netlink_proto_init(void)
2162{
2163 struct sk_buff *dummy_skb;
2164 int i;
2165 unsigned long limit;
2166 unsigned int order;
2167 int err = proto_register(&netlink_proto, 0);
2168
2169 if (err != 0)
2170 goto out;
2171
2172 BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb));
2173
2174 nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);
2175 if (!nl_table)
2176 goto panic;
2177
2178 if (totalram_pages >= (128 * 1024))
2179 limit = totalram_pages >> (21 - PAGE_SHIFT);
2180 else
2181 limit = totalram_pages >> (23 - PAGE_SHIFT);
2182
2183 order = get_bitmask_order(limit) - 1 + PAGE_SHIFT;
2184 limit = (1UL << order) / sizeof(struct hlist_head);
2185 order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1;
2186
2187 for (i = 0; i < MAX_LINKS; i++) {
2188 struct nl_pid_hash *hash = &nl_table[i].hash;
2189
2190 hash->table = nl_pid_hash_zalloc(1 * sizeof(*hash->table));
2191 if (!hash->table) {
2192 while (i-- > 0)
2193 nl_pid_hash_free(nl_table[i].hash.table,
2194 1 * sizeof(*hash->table));
2195 kfree(nl_table);
2196 goto panic;
2197 }
2198 hash->max_shift = order;
2199 hash->shift = 0;
2200 hash->mask = 0;
2201 hash->rehash_time = jiffies;
2202 }
2203
2204 netlink_add_usersock_entry();
2205
2206 sock_register(&netlink_family_ops);
2207 register_pernet_subsys(&netlink_net_ops);
2208
2209 rtnetlink_init();
2210out:
2211 return err;
2212panic:
2213 panic("netlink_init: Cannot allocate nl_table\n");
2214}
2215
2216core_initcall(netlink_proto_init);
2217
