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[PATCH] PCIE: make bus_id for PCI Express devices unique
[linux/fpc-iii.git] / net / netlink / af_netlink.c
bloba67f1b44c9a385e24c1b8c3330e2e869b2e5d55b
1 /*
2 * NETLINK Kernel-user communication protocol.
3 *
4 * Authors: Alan Cox <alan@redhat.com>
5 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith
13 * added netlink_proto_exit
14 * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br>
15 * use nlk_sk, as sk->protinfo is on a diet 8)
16 * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org>
17 * - inc module use count of module that owns
18 * the kernel socket in case userspace opens
19 * socket of same protocol
20 * - remove all module support, since netlink is
21 * mandatory if CONFIG_NET=y these days
22 */
23
24 #include <linux/config.h>
25 #include <linux/module.h>
26
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/smp_lock.h>
49 #include <linux/notifier.h>
50 #include <linux/security.h>
51 #include <linux/jhash.h>
52 #include <linux/jiffies.h>
53 #include <linux/random.h>
54 #include <linux/bitops.h>
55 #include <linux/mm.h>
56 #include <linux/types.h>
57 #include <linux/audit.h>
58
59 #include <net/sock.h>
60 #include <net/scm.h>
61 #include <net/netlink.h>
62
63 #define Nprintk(a...)
64 #define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8)
65
66 struct netlink_sock {
67 /* struct sock has to be the first member of netlink_sock */
68 struct sock sk;
69 u32 pid;
70 u32 dst_pid;
71 u32 dst_group;
72 u32 flags;
73 u32 subscriptions;
74 u32 ngroups;
75 unsigned long *groups;
76 unsigned long state;
77 wait_queue_head_t wait;
78 struct netlink_callback *cb;
79 spinlock_t cb_lock;
80 void (*data_ready)(struct sock *sk, int bytes);
81 struct module *module;
82 };
83
84 #define NETLINK_KERNEL_SOCKET 0x1
85 #define NETLINK_RECV_PKTINFO 0x2
86
87 static inline struct netlink_sock *nlk_sk(struct sock *sk)
88 {
89 return (struct netlink_sock *)sk;
90 }
91
92 struct nl_pid_hash {
93 struct hlist_head *table;
94 unsigned long rehash_time;
95
96 unsigned int mask;
97 unsigned int shift;
98
99 unsigned int entries;
100 unsigned int max_shift;
101
102 u32 rnd;
103 };
104
105 struct netlink_table {
106 struct nl_pid_hash hash;
107 struct hlist_head mc_list;
108 unsigned int nl_nonroot;
109 unsigned int groups;
110 struct module *module;
111 int registered;
112 };
113
114 static struct netlink_table *nl_table;
115
116 static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
117
118 static int netlink_dump(struct sock *sk);
119 static void netlink_destroy_callback(struct netlink_callback *cb);
120
121 static DEFINE_RWLOCK(nl_table_lock);
122 static atomic_t nl_table_users = ATOMIC_INIT(0);
123
124 static struct notifier_block *netlink_chain;
125
126 static u32 netlink_group_mask(u32 group)
127 {
128 return group ? 1 << (group - 1) : 0;
129 }
130
131 static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid)
132 {
133 return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask];
134 }
135
136 static void netlink_sock_destruct(struct sock *sk)
137 {
138 skb_queue_purge(&sk->sk_receive_queue);
139
140 if (!sock_flag(sk, SOCK_DEAD)) {
141 printk("Freeing alive netlink socket %p\n", sk);
142 return;
143 }
144 BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc));
145 BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
146 BUG_TRAP(!nlk_sk(sk)->cb);
147 BUG_TRAP(!nlk_sk(sk)->groups);
148 }
149
150 /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on SMP.
151 * Look, when several writers sleep and reader wakes them up, all but one
152 * immediately hit write lock and grab all the cpus. Exclusive sleep solves
153 * this, _but_ remember, it adds useless work on UP machines.
154 */
155
156 static void netlink_table_grab(void)
157 {
158 write_lock_bh(&nl_table_lock);
159
160 if (atomic_read(&nl_table_users)) {
161 DECLARE_WAITQUEUE(wait, current);
162
163 add_wait_queue_exclusive(&nl_table_wait, &wait);
164 for(;;) {
165 set_current_state(TASK_UNINTERRUPTIBLE);
166 if (atomic_read(&nl_table_users) == 0)
167 break;
168 write_unlock_bh(&nl_table_lock);
169 schedule();
170 write_lock_bh(&nl_table_lock);
171 }
172
173 __set_current_state(TASK_RUNNING);
174 remove_wait_queue(&nl_table_wait, &wait);
175 }
176 }
177
178 static __inline__ void netlink_table_ungrab(void)
179 {
180 write_unlock_bh(&nl_table_lock);
181 wake_up(&nl_table_wait);
182 }
183
184 static __inline__ void
185 netlink_lock_table(void)
186 {
187 /* read_lock() synchronizes us to netlink_table_grab */
188
189 read_lock(&nl_table_lock);
190 atomic_inc(&nl_table_users);
191 read_unlock(&nl_table_lock);
192 }
193
194 static __inline__ void
195 netlink_unlock_table(void)
196 {
197 if (atomic_dec_and_test(&nl_table_users))
198 wake_up(&nl_table_wait);
199 }
200
201 static __inline__ struct sock *netlink_lookup(int protocol, u32 pid)
202 {
203 struct nl_pid_hash *hash = &nl_table[protocol].hash;
204 struct hlist_head *head;
205 struct sock *sk;
206 struct hlist_node *node;
207
208 read_lock(&nl_table_lock);
209 head = nl_pid_hashfn(hash, pid);
210 sk_for_each(sk, node, head) {
211 if (nlk_sk(sk)->pid == pid) {
212 sock_hold(sk);
213 goto found;
214 }
215 }
216 sk = NULL;
217 found:
218 read_unlock(&nl_table_lock);
219 return sk;
220 }
221
222 static inline struct hlist_head *nl_pid_hash_alloc(size_t size)
223 {
224 if (size <= PAGE_SIZE)
225 return kmalloc(size, GFP_ATOMIC);
226 else
227 return (struct hlist_head *)
228 __get_free_pages(GFP_ATOMIC, get_order(size));
229 }
230
231 static inline void nl_pid_hash_free(struct hlist_head *table, size_t size)
232 {
233 if (size <= PAGE_SIZE)
234 kfree(table);
235 else
236 free_pages((unsigned long)table, get_order(size));
237 }
238
239 static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow)
240 {
241 unsigned int omask, mask, shift;
242 size_t osize, size;
243 struct hlist_head *otable, *table;
244 int i;
245
246 omask = mask = hash->mask;
247 osize = size = (mask + 1) * sizeof(*table);
248 shift = hash->shift;
249
250 if (grow) {
251 if (++shift > hash->max_shift)
252 return 0;
253 mask = mask * 2 + 1;
254 size *= 2;
255 }
256
257 table = nl_pid_hash_alloc(size);
258 if (!table)
259 return 0;
260
261 memset(table, 0, size);
262 otable = hash->table;
263 hash->table = table;
264 hash->mask = mask;
265 hash->shift = shift;
266 get_random_bytes(&hash->rnd, sizeof(hash->rnd));
267
268 for (i = 0; i <= omask; i++) {
269 struct sock *sk;
270 struct hlist_node *node, *tmp;
271
272 sk_for_each_safe(sk, node, tmp, &otable[i])
273 __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid));
274 }
275
276 nl_pid_hash_free(otable, osize);
277 hash->rehash_time = jiffies + 10 * 60 * HZ;
278 return 1;
279 }
280
281 static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len)
282 {
283 int avg = hash->entries >> hash->shift;
284
285 if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1))
286 return 1;
287
288 if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) {
289 nl_pid_hash_rehash(hash, 0);
290 return 1;
291 }
292
293 return 0;
294 }
295
296 static const struct proto_ops netlink_ops;
297
298 static int netlink_insert(struct sock *sk, u32 pid)
299 {
300 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
301 struct hlist_head *head;
302 int err = -EADDRINUSE;
303 struct sock *osk;
304 struct hlist_node *node;
305 int len;
306
307 netlink_table_grab();
308 head = nl_pid_hashfn(hash, pid);
309 len = 0;
310 sk_for_each(osk, node, head) {
311 if (nlk_sk(osk)->pid == pid)
312 break;
313 len++;
314 }
315 if (node)
316 goto err;
317
318 err = -EBUSY;
319 if (nlk_sk(sk)->pid)
320 goto err;
321
322 err = -ENOMEM;
323 if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX))
324 goto err;
325
326 if (len && nl_pid_hash_dilute(hash, len))
327 head = nl_pid_hashfn(hash, pid);
328 hash->entries++;
329 nlk_sk(sk)->pid = pid;
330 sk_add_node(sk, head);
331 err = 0;
332
333 err:
334 netlink_table_ungrab();
335 return err;
336 }
337
338 static void netlink_remove(struct sock *sk)
339 {
340 netlink_table_grab();
341 if (sk_del_node_init(sk))
342 nl_table[sk->sk_protocol].hash.entries--;
343 if (nlk_sk(sk)->subscriptions)
344 __sk_del_bind_node(sk);
345 netlink_table_ungrab();
346 }
347
348 static struct proto netlink_proto = {
349 .name = "NETLINK",
350 .owner = THIS_MODULE,
351 .obj_size = sizeof(struct netlink_sock),
352 };
353
354 static int __netlink_create(struct socket *sock, int protocol)
355 {
356 struct sock *sk;
357 struct netlink_sock *nlk;
358
359 sock->ops = &netlink_ops;
360
361 sk = sk_alloc(PF_NETLINK, GFP_KERNEL, &netlink_proto, 1);
362 if (!sk)
363 return -ENOMEM;
364
365 sock_init_data(sock, sk);
366
367 nlk = nlk_sk(sk);
368 spin_lock_init(&nlk->cb_lock);
369 init_waitqueue_head(&nlk->wait);
370
371 sk->sk_destruct = netlink_sock_destruct;
372 sk->sk_protocol = protocol;
373 return 0;
374 }
375
376 static int netlink_create(struct socket *sock, int protocol)
377 {
378 struct module *module = NULL;
379 struct netlink_sock *nlk;
380 unsigned int groups;
381 int err = 0;
382
383 sock->state = SS_UNCONNECTED;
384
385 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
386 return -ESOCKTNOSUPPORT;
387
388 if (protocol<0 || protocol >= MAX_LINKS)
389 return -EPROTONOSUPPORT;
390
391 netlink_lock_table();
392 #ifdef CONFIG_KMOD
393 if (!nl_table[protocol].registered) {
394 netlink_unlock_table();
395 request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
396 netlink_lock_table();
397 }
398 #endif
399 if (nl_table[protocol].registered &&
400 try_module_get(nl_table[protocol].module))
401 module = nl_table[protocol].module;
402 groups = nl_table[protocol].groups;
403 netlink_unlock_table();
404
405 if ((err = __netlink_create(sock, protocol)) < 0)
406 goto out_module;
407
408 nlk = nlk_sk(sock->sk);
409 nlk->module = module;
410 out:
411 return err;
412
413 out_module:
414 module_put(module);
415 goto out;
416 }
417
418 static int netlink_release(struct socket *sock)
419 {
420 struct sock *sk = sock->sk;
421 struct netlink_sock *nlk;
422
423 if (!sk)
424 return 0;
425
426 netlink_remove(sk);
427 nlk = nlk_sk(sk);
428
429 spin_lock(&nlk->cb_lock);
430 if (nlk->cb) {
431 if (nlk->cb->done)
432 nlk->cb->done(nlk->cb);
433 netlink_destroy_callback(nlk->cb);
434 nlk->cb = NULL;
435 }
436 spin_unlock(&nlk->cb_lock);
437
438 /* OK. Socket is unlinked, and, therefore,
439 no new packets will arrive */
440
441 sock_orphan(sk);
442 sock->sk = NULL;
443 wake_up_interruptible_all(&nlk->wait);
444
445 skb_queue_purge(&sk->sk_write_queue);
446
447 if (nlk->pid && !nlk->subscriptions) {
448 struct netlink_notify n = {
449 .protocol = sk->sk_protocol,
450 .pid = nlk->pid,
451 };
452 notifier_call_chain(&netlink_chain, NETLINK_URELEASE, &n);
453 }
454
455 if (nlk->module)
456 module_put(nlk->module);
457
458 if (nlk->flags & NETLINK_KERNEL_SOCKET) {
459 netlink_table_grab();
460 nl_table[sk->sk_protocol].module = NULL;
461 nl_table[sk->sk_protocol].registered = 0;
462 netlink_table_ungrab();
463 }
464
465 kfree(nlk->groups);
466 nlk->groups = NULL;
467
468 sock_put(sk);
469 return 0;
470 }
471
472 static int netlink_autobind(struct socket *sock)
473 {
474 struct sock *sk = sock->sk;
475 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
476 struct hlist_head *head;
477 struct sock *osk;
478 struct hlist_node *node;
479 s32 pid = current->tgid;
480 int err;
481 static s32 rover = -4097;
482
483 retry:
484 cond_resched();
485 netlink_table_grab();
486 head = nl_pid_hashfn(hash, pid);
487 sk_for_each(osk, node, head) {
488 if (nlk_sk(osk)->pid == pid) {
489 /* Bind collision, search negative pid values. */
490 pid = rover--;
491 if (rover > -4097)
492 rover = -4097;
493 netlink_table_ungrab();
494 goto retry;
495 }
496 }
497 netlink_table_ungrab();
498
499 err = netlink_insert(sk, pid);
500 if (err == -EADDRINUSE)
501 goto retry;
502
503 /* If 2 threads race to autobind, that is fine. */
504 if (err == -EBUSY)
505 err = 0;
506
507 return err;
508 }
509
510 static inline int netlink_capable(struct socket *sock, unsigned int flag)
511 {
512 return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) ||
513 capable(CAP_NET_ADMIN);
514 }
515
516 static void
517 netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions)
518 {
519 struct netlink_sock *nlk = nlk_sk(sk);
520
521 if (nlk->subscriptions && !subscriptions)
522 __sk_del_bind_node(sk);
523 else if (!nlk->subscriptions && subscriptions)
524 sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
525 nlk->subscriptions = subscriptions;
526 }
527
528 static int netlink_alloc_groups(struct sock *sk)
529 {
530 struct netlink_sock *nlk = nlk_sk(sk);
531 unsigned int groups;
532 int err = 0;
533
534 netlink_lock_table();
535 groups = nl_table[sk->sk_protocol].groups;
536 if (!nl_table[sk->sk_protocol].registered)
537 err = -ENOENT;
538 netlink_unlock_table();
539
540 if (err)
541 return err;
542
543 nlk->groups = kmalloc(NLGRPSZ(groups), GFP_KERNEL);
544 if (nlk->groups == NULL)
545 return -ENOMEM;
546 memset(nlk->groups, 0, NLGRPSZ(groups));
547 nlk->ngroups = groups;
548 return 0;
549 }
550
551 static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
552 {
553 struct sock *sk = sock->sk;
554 struct netlink_sock *nlk = nlk_sk(sk);
555 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
556 int err;
557
558 if (nladdr->nl_family != AF_NETLINK)
559 return -EINVAL;
560
561 /* Only superuser is allowed to listen multicasts */
562 if (nladdr->nl_groups) {
563 if (!netlink_capable(sock, NL_NONROOT_RECV))
564 return -EPERM;
565 if (nlk->groups == NULL) {
566 err = netlink_alloc_groups(sk);
567 if (err)
568 return err;
569 }
570 }
571
572 if (nlk->pid) {
573 if (nladdr->nl_pid != nlk->pid)
574 return -EINVAL;
575 } else {
576 err = nladdr->nl_pid ?
577 netlink_insert(sk, nladdr->nl_pid) :
578 netlink_autobind(sock);
579 if (err)
580 return err;
581 }
582
583 if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
584 return 0;
585
586 netlink_table_grab();
587 netlink_update_subscriptions(sk, nlk->subscriptions +
588 hweight32(nladdr->nl_groups) -
589 hweight32(nlk->groups[0]));
590 nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups;
591 netlink_table_ungrab();
592
593 return 0;
594 }
595
596 static int netlink_connect(struct socket *sock, struct sockaddr *addr,
597 int alen, int flags)
598 {
599 int err = 0;
600 struct sock *sk = sock->sk;
601 struct netlink_sock *nlk = nlk_sk(sk);
602 struct sockaddr_nl *nladdr=(struct sockaddr_nl*)addr;
603
604 if (addr->sa_family == AF_UNSPEC) {
605 sk->sk_state = NETLINK_UNCONNECTED;
606 nlk->dst_pid = 0;
607 nlk->dst_group = 0;
608 return 0;
609 }
610 if (addr->sa_family != AF_NETLINK)
611 return -EINVAL;
612
613 /* Only superuser is allowed to send multicasts */
614 if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND))
615 return -EPERM;
616
617 if (!nlk->pid)
618 err = netlink_autobind(sock);
619
620 if (err == 0) {
621 sk->sk_state = NETLINK_CONNECTED;
622 nlk->dst_pid = nladdr->nl_pid;
623 nlk->dst_group = ffs(nladdr->nl_groups);
624 }
625
626 return err;
627 }
628
629 static int netlink_getname(struct socket *sock, struct sockaddr *addr, int *addr_len, int peer)
630 {
631 struct sock *sk = sock->sk;
632 struct netlink_sock *nlk = nlk_sk(sk);
633 struct sockaddr_nl *nladdr=(struct sockaddr_nl *)addr;
634
635 nladdr->nl_family = AF_NETLINK;
636 nladdr->nl_pad = 0;
637 *addr_len = sizeof(*nladdr);
638
639 if (peer) {
640 nladdr->nl_pid = nlk->dst_pid;
641 nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
642 } else {
643 nladdr->nl_pid = nlk->pid;
644 nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
645 }
646 return 0;
647 }
648
649 static void netlink_overrun(struct sock *sk)
650 {
651 if (!test_and_set_bit(0, &nlk_sk(sk)->state)) {
652 sk->sk_err = ENOBUFS;
653 sk->sk_error_report(sk);
654 }
655 }
656
657 static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid)
658 {
659 int protocol = ssk->sk_protocol;
660 struct sock *sock;
661 struct netlink_sock *nlk;
662
663 sock = netlink_lookup(protocol, pid);
664 if (!sock)
665 return ERR_PTR(-ECONNREFUSED);
666
667 /* Don't bother queuing skb if kernel socket has no input function */
668 nlk = nlk_sk(sock);
669 if ((nlk->pid == 0 && !nlk->data_ready) ||
670 (sock->sk_state == NETLINK_CONNECTED &&
671 nlk->dst_pid != nlk_sk(ssk)->pid)) {
672 sock_put(sock);
673 return ERR_PTR(-ECONNREFUSED);
674 }
675 return sock;
676 }
677
678 struct sock *netlink_getsockbyfilp(struct file *filp)
679 {
680 struct inode *inode = filp->f_dentry->d_inode;
681 struct sock *sock;
682
683 if (!S_ISSOCK(inode->i_mode))
684 return ERR_PTR(-ENOTSOCK);
685
686 sock = SOCKET_I(inode)->sk;
687 if (sock->sk_family != AF_NETLINK)
688 return ERR_PTR(-EINVAL);
689
690 sock_hold(sock);
691 return sock;
692 }
693
694 /*
695 * Attach a skb to a netlink socket.
696 * The caller must hold a reference to the destination socket. On error, the
697 * reference is dropped. The skb is not send to the destination, just all
698 * all error checks are performed and memory in the queue is reserved.
699 * Return values:
700 * < 0: error. skb freed, reference to sock dropped.
701 * 0: continue
702 * 1: repeat lookup - reference dropped while waiting for socket memory.
703 */
704 int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock, long timeo)
705 {
706 struct netlink_sock *nlk;
707
708 nlk = nlk_sk(sk);
709
710 if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
711 test_bit(0, &nlk->state)) {
712 DECLARE_WAITQUEUE(wait, current);
713 if (!timeo) {
714 if (!nlk->pid)
715 netlink_overrun(sk);
716 sock_put(sk);
717 kfree_skb(skb);
718 return -EAGAIN;
719 }
720
721 __set_current_state(TASK_INTERRUPTIBLE);
722 add_wait_queue(&nlk->wait, &wait);
723
724 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
725 test_bit(0, &nlk->state)) &&
726 !sock_flag(sk, SOCK_DEAD))
727 timeo = schedule_timeout(timeo);
728
729 __set_current_state(TASK_RUNNING);
730 remove_wait_queue(&nlk->wait, &wait);
731 sock_put(sk);
732
733 if (signal_pending(current)) {
734 kfree_skb(skb);
735 return sock_intr_errno(timeo);
736 }
737 return 1;
738 }
739 skb_set_owner_r(skb, sk);
740 return 0;
741 }
742
743 int netlink_sendskb(struct sock *sk, struct sk_buff *skb, int protocol)
744 {
745 int len = skb->len;
746
747 skb_queue_tail(&sk->sk_receive_queue, skb);
748 sk->sk_data_ready(sk, len);
749 sock_put(sk);
750 return len;
751 }
752
753 void netlink_detachskb(struct sock *sk, struct sk_buff *skb)
754 {
755 kfree_skb(skb);
756 sock_put(sk);
757 }
758
759 static inline struct sk_buff *netlink_trim(struct sk_buff *skb,
760 gfp_t allocation)
761 {
762 int delta;
763
764 skb_orphan(skb);
765
766 delta = skb->end - skb->tail;
767 if (delta * 2 < skb->truesize)
768 return skb;
769
770 if (skb_shared(skb)) {
771 struct sk_buff *nskb = skb_clone(skb, allocation);
772 if (!nskb)
773 return skb;
774 kfree_skb(skb);
775 skb = nskb;
776 }
777
778 if (!pskb_expand_head(skb, 0, -delta, allocation))
779 skb->truesize -= delta;
780
781 return skb;
782 }
783
784 int netlink_unicast(struct sock *ssk, struct sk_buff *skb, u32 pid, int nonblock)
785 {
786 struct sock *sk;
787 int err;
788 long timeo;
789
790 skb = netlink_trim(skb, gfp_any());
791
792 timeo = sock_sndtimeo(ssk, nonblock);
793 retry:
794 sk = netlink_getsockbypid(ssk, pid);
795 if (IS_ERR(sk)) {
796 kfree_skb(skb);
797 return PTR_ERR(sk);
798 }
799 err = netlink_attachskb(sk, skb, nonblock, timeo);
800 if (err == 1)
801 goto retry;
802 if (err)
803 return err;
804
805 return netlink_sendskb(sk, skb, ssk->sk_protocol);
806 }
807
808 static __inline__ int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb)
809 {
810 struct netlink_sock *nlk = nlk_sk(sk);
811
812 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
813 !test_bit(0, &nlk->state)) {
814 skb_set_owner_r(skb, sk);
815 skb_queue_tail(&sk->sk_receive_queue, skb);
816 sk->sk_data_ready(sk, skb->len);
817 return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf;
818 }
819 return -1;
820 }
821
822 struct netlink_broadcast_data {
823 struct sock *exclude_sk;
824 u32 pid;
825 u32 group;
826 int failure;
827 int congested;
828 int delivered;
829 gfp_t allocation;
830 struct sk_buff *skb, *skb2;
831 };
832
833 static inline int do_one_broadcast(struct sock *sk,
834 struct netlink_broadcast_data *p)
835 {
836 struct netlink_sock *nlk = nlk_sk(sk);
837 int val;
838
839 if (p->exclude_sk == sk)
840 goto out;
841
842 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
843 !test_bit(p->group - 1, nlk->groups))
844 goto out;
845
846 if (p->failure) {
847 netlink_overrun(sk);
848 goto out;
849 }
850
851 sock_hold(sk);
852 if (p->skb2 == NULL) {
853 if (skb_shared(p->skb)) {
854 p->skb2 = skb_clone(p->skb, p->allocation);
855 } else {
856 p->skb2 = skb_get(p->skb);
857 /*
858 * skb ownership may have been set when
859 * delivered to a previous socket.
860 */
861 skb_orphan(p->skb2);
862 }
863 }
864 if (p->skb2 == NULL) {
865 netlink_overrun(sk);
866 /* Clone failed. Notify ALL listeners. */
867 p->failure = 1;
868 } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) {
869 netlink_overrun(sk);
870 } else {
871 p->congested |= val;
872 p->delivered = 1;
873 p->skb2 = NULL;
874 }
875 sock_put(sk);
876
877 out:
878 return 0;
879 }
880
881 int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
882 u32 group, gfp_t allocation)
883 {
884 struct netlink_broadcast_data info;
885 struct hlist_node *node;
886 struct sock *sk;
887
888 skb = netlink_trim(skb, allocation);
889
890 info.exclude_sk = ssk;
891 info.pid = pid;
892 info.group = group;
893 info.failure = 0;
894 info.congested = 0;
895 info.delivered = 0;
896 info.allocation = allocation;
897 info.skb = skb;
898 info.skb2 = NULL;
899
900 /* While we sleep in clone, do not allow to change socket list */
901
902 netlink_lock_table();
903
904 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
905 do_one_broadcast(sk, &info);
906
907 kfree_skb(skb);
908
909 netlink_unlock_table();
910
911 if (info.skb2)
912 kfree_skb(info.skb2);
913
914 if (info.delivered) {
915 if (info.congested && (allocation & __GFP_WAIT))
916 yield();
917 return 0;
918 }
919 if (info.failure)
920 return -ENOBUFS;
921 return -ESRCH;
922 }
923
924 struct netlink_set_err_data {
925 struct sock *exclude_sk;
926 u32 pid;
927 u32 group;
928 int code;
929 };
930
931 static inline int do_one_set_err(struct sock *sk,
932 struct netlink_set_err_data *p)
933 {
934 struct netlink_sock *nlk = nlk_sk(sk);
935
936 if (sk == p->exclude_sk)
937 goto out;
938
939 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
940 !test_bit(p->group - 1, nlk->groups))
941 goto out;
942
943 sk->sk_err = p->code;
944 sk->sk_error_report(sk);
945 out:
946 return 0;
947 }
948
949 void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code)
950 {
951 struct netlink_set_err_data info;
952 struct hlist_node *node;
953 struct sock *sk;
954
955 info.exclude_sk = ssk;
956 info.pid = pid;
957 info.group = group;
958 info.code = code;
959
960 read_lock(&nl_table_lock);
961
962 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
963 do_one_set_err(sk, &info);
964
965 read_unlock(&nl_table_lock);
966 }
967
968 static int netlink_setsockopt(struct socket *sock, int level, int optname,
969 char __user *optval, int optlen)
970 {
971 struct sock *sk = sock->sk;
972 struct netlink_sock *nlk = nlk_sk(sk);
973 int val = 0, err;
974
975 if (level != SOL_NETLINK)
976 return -ENOPROTOOPT;
977
978 if (optlen >= sizeof(int) &&
979 get_user(val, (int __user *)optval))
980 return -EFAULT;
981
982 switch (optname) {
983 case NETLINK_PKTINFO:
984 if (val)
985 nlk->flags |= NETLINK_RECV_PKTINFO;
986 else
987 nlk->flags &= ~NETLINK_RECV_PKTINFO;
988 err = 0;
989 break;
990 case NETLINK_ADD_MEMBERSHIP:
991 case NETLINK_DROP_MEMBERSHIP: {
992 unsigned int subscriptions;
993 int old, new = optname == NETLINK_ADD_MEMBERSHIP ? 1 : 0;
994
995 if (!netlink_capable(sock, NL_NONROOT_RECV))
996 return -EPERM;
997 if (nlk->groups == NULL) {
998 err = netlink_alloc_groups(sk);
999 if (err)
1000 return err;
1001 }
1002 if (!val || val - 1 >= nlk->ngroups)
1003 return -EINVAL;
1004 netlink_table_grab();
1005 old = test_bit(val - 1, nlk->groups);
1006 subscriptions = nlk->subscriptions - old + new;
1007 if (new)
1008 __set_bit(val - 1, nlk->groups);
1009 else
1010 __clear_bit(val - 1, nlk->groups);
1011 netlink_update_subscriptions(sk, subscriptions);
1012 netlink_table_ungrab();
1013 err = 0;
1014 break;
1015 }
1016 default:
1017 err = -ENOPROTOOPT;
1018 }
1019 return err;
1020 }
1021
1022 static int netlink_getsockopt(struct socket *sock, int level, int optname,
1023 char __user *optval, int __user *optlen)
1024 {
1025 struct sock *sk = sock->sk;
1026 struct netlink_sock *nlk = nlk_sk(sk);
1027 int len, val, err;
1028
1029 if (level != SOL_NETLINK)
1030 return -ENOPROTOOPT;
1031
1032 if (get_user(len, optlen))
1033 return -EFAULT;
1034 if (len < 0)
1035 return -EINVAL;
1036
1037 switch (optname) {
1038 case NETLINK_PKTINFO:
1039 if (len < sizeof(int))
1040 return -EINVAL;
1041 len = sizeof(int);
1042 val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0;
1043 put_user(len, optlen);
1044 put_user(val, optval);
1045 err = 0;
1046 break;
1047 default:
1048 err = -ENOPROTOOPT;
1049 }
1050 return err;
1051 }
1052
1053 static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
1054 {
1055 struct nl_pktinfo info;
1056
1057 info.group = NETLINK_CB(skb).dst_group;
1058 put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info);
1059 }
1060
1061 static inline void netlink_rcv_wake(struct sock *sk)
1062 {
1063 struct netlink_sock *nlk = nlk_sk(sk);
1064
1065 if (skb_queue_empty(&sk->sk_receive_queue))
1066 clear_bit(0, &nlk->state);
1067 if (!test_bit(0, &nlk->state))
1068 wake_up_interruptible(&nlk->wait);
1069 }
1070
1071 static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
1072 struct msghdr *msg, size_t len)
1073 {
1074 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1075 struct sock *sk = sock->sk;
1076 struct netlink_sock *nlk = nlk_sk(sk);
1077 struct sockaddr_nl *addr=msg->msg_name;
1078 u32 dst_pid;
1079 u32 dst_group;
1080 struct sk_buff *skb;
1081 int err;
1082 struct scm_cookie scm;
1083
1084 if (msg->msg_flags&MSG_OOB)
1085 return -EOPNOTSUPP;
1086
1087 if (NULL == siocb->scm)
1088 siocb->scm = &scm;
1089 err = scm_send(sock, msg, siocb->scm);
1090 if (err < 0)
1091 return err;
1092
1093 if (msg->msg_namelen) {
1094 if (addr->nl_family != AF_NETLINK)
1095 return -EINVAL;
1096 dst_pid = addr->nl_pid;
1097 dst_group = ffs(addr->nl_groups);
1098 if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND))
1099 return -EPERM;
1100 } else {
1101 dst_pid = nlk->dst_pid;
1102 dst_group = nlk->dst_group;
1103 }
1104
1105 if (!nlk->pid) {
1106 err = netlink_autobind(sock);
1107 if (err)
1108 goto out;
1109 }
1110
1111 err = -EMSGSIZE;
1112 if (len > sk->sk_sndbuf - 32)
1113 goto out;
1114 err = -ENOBUFS;
1115 skb = alloc_skb(len, GFP_KERNEL);
1116 if (skb==NULL)
1117 goto out;
1118
1119 NETLINK_CB(skb).pid = nlk->pid;
1120 NETLINK_CB(skb).dst_pid = dst_pid;
1121 NETLINK_CB(skb).dst_group = dst_group;
1122 NETLINK_CB(skb).loginuid = audit_get_loginuid(current->audit_context);
1123 memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1124
1125 /* What can I do? Netlink is asynchronous, so that
1126 we will have to save current capabilities to
1127 check them, when this message will be delivered
1128 to corresponding kernel module. --ANK (980802)
1129 */
1130
1131 err = -EFAULT;
1132 if (memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len)) {
1133 kfree_skb(skb);
1134 goto out;
1135 }
1136
1137 err = security_netlink_send(sk, skb);
1138 if (err) {
1139 kfree_skb(skb);
1140 goto out;
1141 }
1142
1143 if (dst_group) {
1144 atomic_inc(&skb->users);
1145 netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL);
1146 }
1147 err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT);
1148
1149 out:
1150 return err;
1151 }
1152
1153 static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
1154 struct msghdr *msg, size_t len,
1155 int flags)
1156 {
1157 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1158 struct scm_cookie scm;
1159 struct sock *sk = sock->sk;
1160 struct netlink_sock *nlk = nlk_sk(sk);
1161 int noblock = flags&MSG_DONTWAIT;
1162 size_t copied;
1163 struct sk_buff *skb;
1164 int err;
1165
1166 if (flags&MSG_OOB)
1167 return -EOPNOTSUPP;
1168
1169 copied = 0;
1170
1171 skb = skb_recv_datagram(sk,flags,noblock,&err);
1172 if (skb==NULL)
1173 goto out;
1174
1175 msg->msg_namelen = 0;
1176
1177 copied = skb->len;
1178 if (len < copied) {
1179 msg->msg_flags |= MSG_TRUNC;
1180 copied = len;
1181 }
1182
1183 skb->h.raw = skb->data;
1184 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
1185
1186 if (msg->msg_name) {
1187 struct sockaddr_nl *addr = (struct sockaddr_nl*)msg->msg_name;
1188 addr->nl_family = AF_NETLINK;
1189 addr->nl_pad = 0;
1190 addr->nl_pid = NETLINK_CB(skb).pid;
1191 addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group);
1192 msg->msg_namelen = sizeof(*addr);
1193 }
1194
1195 if (NULL == siocb->scm) {
1196 memset(&scm, 0, sizeof(scm));
1197 siocb->scm = &scm;
1198 }
1199 siocb->scm->creds = *NETLINK_CREDS(skb);
1200 skb_free_datagram(sk, skb);
1201
1202 if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2)
1203 netlink_dump(sk);
1204
1205 scm_recv(sock, msg, siocb->scm, flags);
1206 if (nlk->flags & NETLINK_RECV_PKTINFO)
1207 netlink_cmsg_recv_pktinfo(msg, skb);
1208
1209 out:
1210 netlink_rcv_wake(sk);
1211 return err ? : copied;
1212 }
1213
1214 static void netlink_data_ready(struct sock *sk, int len)
1215 {
1216 struct netlink_sock *nlk = nlk_sk(sk);
1217
1218 if (nlk->data_ready)
1219 nlk->data_ready(sk, len);
1220 netlink_rcv_wake(sk);
1221 }
1222
1223 /*
1224 * We export these functions to other modules. They provide a
1225 * complete set of kernel non-blocking support for message
1226 * queueing.
1227 */
1228
1229 struct sock *
1230 netlink_kernel_create(int unit, unsigned int groups,
1231 void (*input)(struct sock *sk, int len),
1232 struct module *module)
1233 {
1234 struct socket *sock;
1235 struct sock *sk;
1236 struct netlink_sock *nlk;
1237
1238 if (!nl_table)
1239 return NULL;
1240
1241 if (unit<0 || unit>=MAX_LINKS)
1242 return NULL;
1243
1244 if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
1245 return NULL;
1246
1247 if (__netlink_create(sock, unit) < 0)
1248 goto out_sock_release;
1249
1250 sk = sock->sk;
1251 sk->sk_data_ready = netlink_data_ready;
1252 if (input)
1253 nlk_sk(sk)->data_ready = input;
1254
1255 if (netlink_insert(sk, 0))
1256 goto out_sock_release;
1257
1258 nlk = nlk_sk(sk);
1259 nlk->flags |= NETLINK_KERNEL_SOCKET;
1260
1261 netlink_table_grab();
1262 nl_table[unit].groups = groups < 32 ? 32 : groups;
1263 nl_table[unit].module = module;
1264 nl_table[unit].registered = 1;
1265 netlink_table_ungrab();
1266
1267 return sk;
1268
1269 out_sock_release:
1270 sock_release(sock);
1271 return NULL;
1272 }
1273
1274 void netlink_set_nonroot(int protocol, unsigned int flags)
1275 {
1276 if ((unsigned int)protocol < MAX_LINKS)
1277 nl_table[protocol].nl_nonroot = flags;
1278 }
1279
1280 static void netlink_destroy_callback(struct netlink_callback *cb)
1281 {
1282 if (cb->skb)
1283 kfree_skb(cb->skb);
1284 kfree(cb);
1285 }
1286
1287 /*
1288 * It looks a bit ugly.
1289 * It would be better to create kernel thread.
1290 */
1291
1292 static int netlink_dump(struct sock *sk)
1293 {
1294 struct netlink_sock *nlk = nlk_sk(sk);
1295 struct netlink_callback *cb;
1296 struct sk_buff *skb;
1297 struct nlmsghdr *nlh;
1298 int len;
1299
1300 skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL);
1301 if (!skb)
1302 return -ENOBUFS;
1303
1304 spin_lock(&nlk->cb_lock);
1305
1306 cb = nlk->cb;
1307 if (cb == NULL) {
1308 spin_unlock(&nlk->cb_lock);
1309 kfree_skb(skb);
1310 return -EINVAL;
1311 }
1312
1313 len = cb->dump(skb, cb);
1314
1315 if (len > 0) {
1316 spin_unlock(&nlk->cb_lock);
1317 skb_queue_tail(&sk->sk_receive_queue, skb);
1318 sk->sk_data_ready(sk, len);
1319 return 0;
1320 }
1321
1322 nlh = NLMSG_NEW_ANSWER(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI);
1323 memcpy(NLMSG_DATA(nlh), &len, sizeof(len));
1324 skb_queue_tail(&sk->sk_receive_queue, skb);
1325 sk->sk_data_ready(sk, skb->len);
1326
1327 if (cb->done)
1328 cb->done(cb);
1329 nlk->cb = NULL;
1330 spin_unlock(&nlk->cb_lock);
1331
1332 netlink_destroy_callback(cb);
1333 return 0;
1334
1335 nlmsg_failure:
1336 return -ENOBUFS;
1337 }
1338
1339 int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
1340 struct nlmsghdr *nlh,
1341 int (*dump)(struct sk_buff *skb, struct netlink_callback*),
1342 int (*done)(struct netlink_callback*))
1343 {
1344 struct netlink_callback *cb;
1345 struct sock *sk;
1346 struct netlink_sock *nlk;
1347
1348 cb = kmalloc(sizeof(*cb), GFP_KERNEL);
1349 if (cb == NULL)
1350 return -ENOBUFS;
1351
1352 memset(cb, 0, sizeof(*cb));
1353 cb->dump = dump;
1354 cb->done = done;
1355 cb->nlh = nlh;
1356 atomic_inc(&skb->users);
1357 cb->skb = skb;
1358
1359 sk = netlink_lookup(ssk->sk_protocol, NETLINK_CB(skb).pid);
1360 if (sk == NULL) {
1361 netlink_destroy_callback(cb);
1362 return -ECONNREFUSED;
1363 }
1364 nlk = nlk_sk(sk);
1365 /* A dump is in progress... */
1366 spin_lock(&nlk->cb_lock);
1367 if (nlk->cb) {
1368 spin_unlock(&nlk->cb_lock);
1369 netlink_destroy_callback(cb);
1370 sock_put(sk);
1371 return -EBUSY;
1372 }
1373 nlk->cb = cb;
1374 spin_unlock(&nlk->cb_lock);
1375
1376 netlink_dump(sk);
1377 sock_put(sk);
1378 return 0;
1379 }
1380
1381 void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
1382 {
1383 struct sk_buff *skb;
1384 struct nlmsghdr *rep;
1385 struct nlmsgerr *errmsg;
1386 int size;
1387
1388 if (err == 0)
1389 size = NLMSG_SPACE(sizeof(struct nlmsgerr));
1390 else
1391 size = NLMSG_SPACE(4 + NLMSG_ALIGN(nlh->nlmsg_len));
1392
1393 skb = alloc_skb(size, GFP_KERNEL);
1394 if (!skb) {
1395 struct sock *sk;
1396
1397 sk = netlink_lookup(in_skb->sk->sk_protocol,
1398 NETLINK_CB(in_skb).pid);
1399 if (sk) {
1400 sk->sk_err = ENOBUFS;
1401 sk->sk_error_report(sk);
1402 sock_put(sk);
1403 }
1404 return;
1405 }
1406
1407 rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
1408 NLMSG_ERROR, sizeof(struct nlmsgerr), 0);
1409 errmsg = NLMSG_DATA(rep);
1410 errmsg->error = err;
1411 memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(struct nlmsghdr));
1412 netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
1413 }
1414
1415 static int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
1416 struct nlmsghdr *, int *))
1417 {
1418 unsigned int total_len;
1419 struct nlmsghdr *nlh;
1420 int err;
1421
1422 while (skb->len >= nlmsg_total_size(0)) {
1423 nlh = (struct nlmsghdr *) skb->data;
1424
1425 if (skb->len < nlh->nlmsg_len)
1426 return 0;
1427
1428 total_len = min(NLMSG_ALIGN(nlh->nlmsg_len), skb->len);
1429
1430 if (cb(skb, nlh, &err) < 0) {
1431 /* Not an error, but we have to interrupt processing
1432 * here. Note: that in this case we do not pull
1433 * message from skb, it will be processed later.
1434 */
1435 if (err == 0)
1436 return -1;
1437 netlink_ack(skb, nlh, err);
1438 } else if (nlh->nlmsg_flags & NLM_F_ACK)
1439 netlink_ack(skb, nlh, 0);
1440
1441 skb_pull(skb, total_len);
1442 }
1443
1444 return 0;
1445 }
1446
1447 /**
1448 * nelink_run_queue - Process netlink receive queue.
1449 * @sk: Netlink socket containing the queue
1450 * @qlen: Place to store queue length upon entry
1451 * @cb: Callback function invoked for each netlink message found
1452 *
1453 * Processes as much as there was in the queue upon entry and invokes
1454 * a callback function for each netlink message found. The callback
1455 * function may refuse a message by returning a negative error code
1456 * but setting the error pointer to 0 in which case this function
1457 * returns with a qlen != 0.
1458 *
1459 * qlen must be initialized to 0 before the initial entry, afterwards
1460 * the function may be called repeatedly until qlen reaches 0.
1461 */
1462 void netlink_run_queue(struct sock *sk, unsigned int *qlen,
1463 int (*cb)(struct sk_buff *, struct nlmsghdr *, int *))
1464 {
1465 struct sk_buff *skb;
1466
1467 if (!*qlen || *qlen > skb_queue_len(&sk->sk_receive_queue))
1468 *qlen = skb_queue_len(&sk->sk_receive_queue);
1469
1470 for (; *qlen; (*qlen)--) {
1471 skb = skb_dequeue(&sk->sk_receive_queue);
1472 if (netlink_rcv_skb(skb, cb)) {
1473 if (skb->len)
1474 skb_queue_head(&sk->sk_receive_queue, skb);
1475 else {
1476 kfree_skb(skb);
1477 (*qlen)--;
1478 }
1479 break;
1480 }
1481
1482 kfree_skb(skb);
1483 }
1484 }
1485
1486 /**
1487 * netlink_queue_skip - Skip netlink message while processing queue.
1488 * @nlh: Netlink message to be skipped
1489 * @skb: Socket buffer containing the netlink messages.
1490 *
1491 * Pulls the given netlink message off the socket buffer so the next
1492 * call to netlink_queue_run() will not reconsider the message.
1493 */
1494 void netlink_queue_skip(struct nlmsghdr *nlh, struct sk_buff *skb)
1495 {
1496 int msglen = NLMSG_ALIGN(nlh->nlmsg_len);
1497
1498 if (msglen > skb->len)
1499 msglen = skb->len;
1500
1501 skb_pull(skb, msglen);
1502 }
1503
1504 #ifdef CONFIG_PROC_FS
1505 struct nl_seq_iter {
1506 int link;
1507 int hash_idx;
1508 };
1509
1510 static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos)
1511 {
1512 struct nl_seq_iter *iter = seq->private;
1513 int i, j;
1514 struct sock *s;
1515 struct hlist_node *node;
1516 loff_t off = 0;
1517
1518 for (i=0; i<MAX_LINKS; i++) {
1519 struct nl_pid_hash *hash = &nl_table[i].hash;
1520
1521 for (j = 0; j <= hash->mask; j++) {
1522 sk_for_each(s, node, &hash->table[j]) {
1523 if (off == pos) {
1524 iter->link = i;
1525 iter->hash_idx = j;
1526 return s;
1527 }
1528 ++off;
1529 }
1530 }
1531 }
1532 return NULL;
1533 }
1534
1535 static void *netlink_seq_start(struct seq_file *seq, loff_t *pos)
1536 {
1537 read_lock(&nl_table_lock);
1538 return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN;
1539 }
1540
1541 static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1542 {
1543 struct sock *s;
1544 struct nl_seq_iter *iter;
1545 int i, j;
1546
1547 ++*pos;
1548
1549 if (v == SEQ_START_TOKEN)
1550 return netlink_seq_socket_idx(seq, 0);
1551
1552 s = sk_next(v);
1553 if (s)
1554 return s;
1555
1556 iter = seq->private;
1557 i = iter->link;
1558 j = iter->hash_idx + 1;
1559
1560 do {
1561 struct nl_pid_hash *hash = &nl_table[i].hash;
1562
1563 for (; j <= hash->mask; j++) {
1564 s = sk_head(&hash->table[j]);
1565 if (s) {
1566 iter->link = i;
1567 iter->hash_idx = j;
1568 return s;
1569 }
1570 }
1571
1572 j = 0;
1573 } while (++i < MAX_LINKS);
1574
1575 return NULL;
1576 }
1577
1578 static void netlink_seq_stop(struct seq_file *seq, void *v)
1579 {
1580 read_unlock(&nl_table_lock);
1581 }
1582
1583
1584 static int netlink_seq_show(struct seq_file *seq, void *v)
1585 {
1586 if (v == SEQ_START_TOKEN)
1587 seq_puts(seq,
1588 "sk Eth Pid Groups "
1589 "Rmem Wmem Dump Locks\n");
1590 else {
1591 struct sock *s = v;
1592 struct netlink_sock *nlk = nlk_sk(s);
1593
1594 seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %d\n",
1595 s,
1596 s->sk_protocol,
1597 nlk->pid,
1598 nlk->groups ? (u32)nlk->groups[0] : 0,
1599 atomic_read(&s->sk_rmem_alloc),
1600 atomic_read(&s->sk_wmem_alloc),
1601 nlk->cb,
1602 atomic_read(&s->sk_refcnt)
1603 );
1604
1605 }
1606 return 0;
1607 }
1608
1609 static struct seq_operations netlink_seq_ops = {
1610 .start = netlink_seq_start,
1611 .next = netlink_seq_next,
1612 .stop = netlink_seq_stop,
1613 .show = netlink_seq_show,
1614 };
1615
1616
1617 static int netlink_seq_open(struct inode *inode, struct file *file)
1618 {
1619 struct seq_file *seq;
1620 struct nl_seq_iter *iter;
1621 int err;
1622
1623 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
1624 if (!iter)
1625 return -ENOMEM;
1626
1627 err = seq_open(file, &netlink_seq_ops);
1628 if (err) {
1629 kfree(iter);
1630 return err;
1631 }
1632
1633 memset(iter, 0, sizeof(*iter));
1634 seq = file->private_data;
1635 seq->private = iter;
1636 return 0;
1637 }
1638
1639 static struct file_operations netlink_seq_fops = {
1640 .owner = THIS_MODULE,
1641 .open = netlink_seq_open,
1642 .read = seq_read,
1643 .llseek = seq_lseek,
1644 .release = seq_release_private,
1645 };
1646
1647 #endif
1648
1649 int netlink_register_notifier(struct notifier_block *nb)
1650 {
1651 return notifier_chain_register(&netlink_chain, nb);
1652 }
1653
1654 int netlink_unregister_notifier(struct notifier_block *nb)
1655 {
1656 return notifier_chain_unregister(&netlink_chain, nb);
1657 }
1658
1659 static const struct proto_ops netlink_ops = {
1660 .family = PF_NETLINK,
1661 .owner = THIS_MODULE,
1662 .release = netlink_release,
1663 .bind = netlink_bind,
1664 .connect = netlink_connect,
1665 .socketpair = sock_no_socketpair,
1666 .accept = sock_no_accept,
1667 .getname = netlink_getname,
1668 .poll = datagram_poll,
1669 .ioctl = sock_no_ioctl,
1670 .listen = sock_no_listen,
1671 .shutdown = sock_no_shutdown,
1672 .setsockopt = netlink_setsockopt,
1673 .getsockopt = netlink_getsockopt,
1674 .sendmsg = netlink_sendmsg,
1675 .recvmsg = netlink_recvmsg,
1676 .mmap = sock_no_mmap,
1677 .sendpage = sock_no_sendpage,
1678 };
1679
1680 static struct net_proto_family netlink_family_ops = {
1681 .family = PF_NETLINK,
1682 .create = netlink_create,
1683 .owner = THIS_MODULE, /* for consistency 8) */
1684 };
1685
1686 extern void netlink_skb_parms_too_large(void);
1687
1688 static int __init netlink_proto_init(void)
1689 {
1690 struct sk_buff *dummy_skb;
1691 int i;
1692 unsigned long max;
1693 unsigned int order;
1694 int err = proto_register(&netlink_proto, 0);
1695
1696 if (err != 0)
1697 goto out;
1698
1699 if (sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb))
1700 netlink_skb_parms_too_large();
1701
1702 nl_table = kmalloc(sizeof(*nl_table) * MAX_LINKS, GFP_KERNEL);
1703 if (!nl_table) {
1704 enomem:
1705 printk(KERN_CRIT "netlink_init: Cannot allocate nl_table\n");
1706 return -ENOMEM;
1707 }
1708
1709 memset(nl_table, 0, sizeof(*nl_table) * MAX_LINKS);
1710
1711 if (num_physpages >= (128 * 1024))
1712 max = num_physpages >> (21 - PAGE_SHIFT);
1713 else
1714 max = num_physpages >> (23 - PAGE_SHIFT);
1715
1716 order = get_bitmask_order(max) - 1 + PAGE_SHIFT;
1717 max = (1UL << order) / sizeof(struct hlist_head);
1718 order = get_bitmask_order(max > UINT_MAX ? UINT_MAX : max) - 1;
1719
1720 for (i = 0; i < MAX_LINKS; i++) {
1721 struct nl_pid_hash *hash = &nl_table[i].hash;
1722
1723 hash->table = nl_pid_hash_alloc(1 * sizeof(*hash->table));
1724 if (!hash->table) {
1725 while (i-- > 0)
1726 nl_pid_hash_free(nl_table[i].hash.table,
1727 1 * sizeof(*hash->table));
1728 kfree(nl_table);
1729 goto enomem;
1730 }
1731 memset(hash->table, 0, 1 * sizeof(*hash->table));
1732 hash->max_shift = order;
1733 hash->shift = 0;
1734 hash->mask = 0;
1735 hash->rehash_time = jiffies;
1736 }
1737
1738 sock_register(&netlink_family_ops);
1739 #ifdef CONFIG_PROC_FS
1740 proc_net_fops_create("netlink", 0, &netlink_seq_fops);
1741 #endif
1742 /* The netlink device handler may be needed early. */
1743 rtnetlink_init();
1744 out:
1745 return err;
1746 }
1747
1748 core_initcall(netlink_proto_init);
1749
1750 EXPORT_SYMBOL(netlink_ack);
1751 EXPORT_SYMBOL(netlink_run_queue);
1752 EXPORT_SYMBOL(netlink_queue_skip);
1753 EXPORT_SYMBOL(netlink_broadcast);
1754 EXPORT_SYMBOL(netlink_dump_start);
1755 EXPORT_SYMBOL(netlink_kernel_create);
1756 EXPORT_SYMBOL(netlink_register_notifier);
1757 EXPORT_SYMBOL(netlink_set_err);
1758 EXPORT_SYMBOL(netlink_set_nonroot);
1759 EXPORT_SYMBOL(netlink_unicast);
1760 EXPORT_SYMBOL(netlink_unregister_notifier);
1761
Linux with added FPC-III support