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SUNRPC: Provide a callback to allow free pages allocated during xdr encoding
[linux-2.6/verdex.git] / net / netlink / af_netlink.c
blob678c3f2c0d0bdd9abad85d3eeb16acf38c8a01d3
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
62 #define Nprintk(a...)
63 #define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8)
64
65 struct netlink_sock {
66 /* struct sock has to be the first member of netlink_sock */
67 struct sock sk;
68 u32 pid;
69 u32 dst_pid;
70 u32 dst_group;
71 u32 flags;
72 u32 subscriptions;
73 u32 ngroups;
74 unsigned long *groups;
75 unsigned long state;
76 wait_queue_head_t wait;
77 struct netlink_callback *cb;
78 spinlock_t cb_lock;
79 void (*data_ready)(struct sock *sk, int bytes);
80 struct module *module;
81 };
82
83 #define NETLINK_KERNEL_SOCKET 0x1
84 #define NETLINK_RECV_PKTINFO 0x2
85
86 static inline struct netlink_sock *nlk_sk(struct sock *sk)
87 {
88 return (struct netlink_sock *)sk;
89 }
90
91 struct nl_pid_hash {
92 struct hlist_head *table;
93 unsigned long rehash_time;
94
95 unsigned int mask;
96 unsigned int shift;
97
98 unsigned int entries;
99 unsigned int max_shift;
100
101 u32 rnd;
102 };
103
104 struct netlink_table {
105 struct nl_pid_hash hash;
106 struct hlist_head mc_list;
107 unsigned int nl_nonroot;
108 unsigned int groups;
109 struct module *module;
110 int registered;
111 };
112
113 static struct netlink_table *nl_table;
114
115 static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
116
117 static int netlink_dump(struct sock *sk);
118 static void netlink_destroy_callback(struct netlink_callback *cb);
119
120 static DEFINE_RWLOCK(nl_table_lock);
121 static atomic_t nl_table_users = ATOMIC_INIT(0);
122
123 static struct notifier_block *netlink_chain;
124
125 static u32 netlink_group_mask(u32 group)
126 {
127 return group ? 1 << (group - 1) : 0;
128 }
129
130 static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid)
131 {
132 return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask];
133 }
134
135 static void netlink_sock_destruct(struct sock *sk)
136 {
137 skb_queue_purge(&sk->sk_receive_queue);
138
139 if (!sock_flag(sk, SOCK_DEAD)) {
140 printk("Freeing alive netlink socket %p\n", sk);
141 return;
142 }
143 BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc));
144 BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
145 BUG_TRAP(!nlk_sk(sk)->cb);
146 BUG_TRAP(!nlk_sk(sk)->groups);
147 }
148
149 /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on SMP.
150 * Look, when several writers sleep and reader wakes them up, all but one
151 * immediately hit write lock and grab all the cpus. Exclusive sleep solves
152 * this, _but_ remember, it adds useless work on UP machines.
153 */
154
155 static void netlink_table_grab(void)
156 {
157 write_lock_bh(&nl_table_lock);
158
159 if (atomic_read(&nl_table_users)) {
160 DECLARE_WAITQUEUE(wait, current);
161
162 add_wait_queue_exclusive(&nl_table_wait, &wait);
163 for(;;) {
164 set_current_state(TASK_UNINTERRUPTIBLE);
165 if (atomic_read(&nl_table_users) == 0)
166 break;
167 write_unlock_bh(&nl_table_lock);
168 schedule();
169 write_lock_bh(&nl_table_lock);
170 }
171
172 __set_current_state(TASK_RUNNING);
173 remove_wait_queue(&nl_table_wait, &wait);
174 }
175 }
176
177 static __inline__ void netlink_table_ungrab(void)
178 {
179 write_unlock_bh(&nl_table_lock);
180 wake_up(&nl_table_wait);
181 }
182
183 static __inline__ void
184 netlink_lock_table(void)
185 {
186 /* read_lock() synchronizes us to netlink_table_grab */
187
188 read_lock(&nl_table_lock);
189 atomic_inc(&nl_table_users);
190 read_unlock(&nl_table_lock);
191 }
192
193 static __inline__ void
194 netlink_unlock_table(void)
195 {
196 if (atomic_dec_and_test(&nl_table_users))
197 wake_up(&nl_table_wait);
198 }
199
200 static __inline__ struct sock *netlink_lookup(int protocol, u32 pid)
201 {
202 struct nl_pid_hash *hash = &nl_table[protocol].hash;
203 struct hlist_head *head;
204 struct sock *sk;
205 struct hlist_node *node;
206
207 read_lock(&nl_table_lock);
208 head = nl_pid_hashfn(hash, pid);
209 sk_for_each(sk, node, head) {
210 if (nlk_sk(sk)->pid == pid) {
211 sock_hold(sk);
212 goto found;
213 }
214 }
215 sk = NULL;
216 found:
217 read_unlock(&nl_table_lock);
218 return sk;
219 }
220
221 static inline struct hlist_head *nl_pid_hash_alloc(size_t size)
222 {
223 if (size <= PAGE_SIZE)
224 return kmalloc(size, GFP_ATOMIC);
225 else
226 return (struct hlist_head *)
227 __get_free_pages(GFP_ATOMIC, get_order(size));
228 }
229
230 static inline void nl_pid_hash_free(struct hlist_head *table, size_t size)
231 {
232 if (size <= PAGE_SIZE)
233 kfree(table);
234 else
235 free_pages((unsigned long)table, get_order(size));
236 }
237
238 static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow)
239 {
240 unsigned int omask, mask, shift;
241 size_t osize, size;
242 struct hlist_head *otable, *table;
243 int i;
244
245 omask = mask = hash->mask;
246 osize = size = (mask + 1) * sizeof(*table);
247 shift = hash->shift;
248
249 if (grow) {
250 if (++shift > hash->max_shift)
251 return 0;
252 mask = mask * 2 + 1;
253 size *= 2;
254 }
255
256 table = nl_pid_hash_alloc(size);
257 if (!table)
258 return 0;
259
260 memset(table, 0, size);
261 otable = hash->table;
262 hash->table = table;
263 hash->mask = mask;
264 hash->shift = shift;
265 get_random_bytes(&hash->rnd, sizeof(hash->rnd));
266
267 for (i = 0; i <= omask; i++) {
268 struct sock *sk;
269 struct hlist_node *node, *tmp;
270
271 sk_for_each_safe(sk, node, tmp, &otable[i])
272 __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid));
273 }
274
275 nl_pid_hash_free(otable, osize);
276 hash->rehash_time = jiffies + 10 * 60 * HZ;
277 return 1;
278 }
279
280 static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len)
281 {
282 int avg = hash->entries >> hash->shift;
283
284 if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1))
285 return 1;
286
287 if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) {
288 nl_pid_hash_rehash(hash, 0);
289 return 1;
290 }
291
292 return 0;
293 }
294
295 static struct proto_ops netlink_ops;
296
297 static int netlink_insert(struct sock *sk, u32 pid)
298 {
299 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
300 struct hlist_head *head;
301 int err = -EADDRINUSE;
302 struct sock *osk;
303 struct hlist_node *node;
304 int len;
305
306 netlink_table_grab();
307 head = nl_pid_hashfn(hash, pid);
308 len = 0;
309 sk_for_each(osk, node, head) {
310 if (nlk_sk(osk)->pid == pid)
311 break;
312 len++;
313 }
314 if (node)
315 goto err;
316
317 err = -EBUSY;
318 if (nlk_sk(sk)->pid)
319 goto err;
320
321 err = -ENOMEM;
322 if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX))
323 goto err;
324
325 if (len && nl_pid_hash_dilute(hash, len))
326 head = nl_pid_hashfn(hash, pid);
327 hash->entries++;
328 nlk_sk(sk)->pid = pid;
329 sk_add_node(sk, head);
330 err = 0;
331
332 err:
333 netlink_table_ungrab();
334 return err;
335 }
336
337 static void netlink_remove(struct sock *sk)
338 {
339 netlink_table_grab();
340 if (sk_del_node_init(sk))
341 nl_table[sk->sk_protocol].hash.entries--;
342 if (nlk_sk(sk)->subscriptions)
343 __sk_del_bind_node(sk);
344 netlink_table_ungrab();
345 }
346
347 static struct proto netlink_proto = {
348 .name = "NETLINK",
349 .owner = THIS_MODULE,
350 .obj_size = sizeof(struct netlink_sock),
351 };
352
353 static int __netlink_create(struct socket *sock, int protocol)
354 {
355 struct sock *sk;
356 struct netlink_sock *nlk;
357
358 sock->ops = &netlink_ops;
359
360 sk = sk_alloc(PF_NETLINK, GFP_KERNEL, &netlink_proto, 1);
361 if (!sk)
362 return -ENOMEM;
363
364 sock_init_data(sock, sk);
365
366 nlk = nlk_sk(sk);
367 spin_lock_init(&nlk->cb_lock);
368 init_waitqueue_head(&nlk->wait);
369
370 sk->sk_destruct = netlink_sock_destruct;
371 sk->sk_protocol = protocol;
372 return 0;
373 }
374
375 static int netlink_create(struct socket *sock, int protocol)
376 {
377 struct module *module = NULL;
378 struct netlink_sock *nlk;
379 unsigned int groups;
380 int err = 0;
381
382 sock->state = SS_UNCONNECTED;
383
384 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
385 return -ESOCKTNOSUPPORT;
386
387 if (protocol<0 || protocol >= MAX_LINKS)
388 return -EPROTONOSUPPORT;
389
390 netlink_lock_table();
391 #ifdef CONFIG_KMOD
392 if (!nl_table[protocol].registered) {
393 netlink_unlock_table();
394 request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
395 netlink_lock_table();
396 }
397 #endif
398 if (nl_table[protocol].registered &&
399 try_module_get(nl_table[protocol].module))
400 module = nl_table[protocol].module;
401 groups = nl_table[protocol].groups;
402 netlink_unlock_table();
403
404 if ((err = __netlink_create(sock, protocol) < 0))
405 goto out_module;
406
407 nlk = nlk_sk(sock->sk);
408 nlk->module = module;
409 out:
410 return err;
411
412 out_module:
413 module_put(module);
414 goto out;
415 }
416
417 static int netlink_release(struct socket *sock)
418 {
419 struct sock *sk = sock->sk;
420 struct netlink_sock *nlk;
421
422 if (!sk)
423 return 0;
424
425 netlink_remove(sk);
426 nlk = nlk_sk(sk);
427
428 spin_lock(&nlk->cb_lock);
429 if (nlk->cb) {
430 nlk->cb->done(nlk->cb);
431 netlink_destroy_callback(nlk->cb);
432 nlk->cb = NULL;
433 }
434 spin_unlock(&nlk->cb_lock);
435
436 /* OK. Socket is unlinked, and, therefore,
437 no new packets will arrive */
438
439 sock_orphan(sk);
440 sock->sk = NULL;
441 wake_up_interruptible_all(&nlk->wait);
442
443 skb_queue_purge(&sk->sk_write_queue);
444
445 if (nlk->pid && !nlk->subscriptions) {
446 struct netlink_notify n = {
447 .protocol = sk->sk_protocol,
448 .pid = nlk->pid,
449 };
450 notifier_call_chain(&netlink_chain, NETLINK_URELEASE, &n);
451 }
452
453 if (nlk->module)
454 module_put(nlk->module);
455
456 if (nlk->flags & NETLINK_KERNEL_SOCKET) {
457 netlink_table_grab();
458 nl_table[sk->sk_protocol].module = NULL;
459 nl_table[sk->sk_protocol].registered = 0;
460 netlink_table_ungrab();
461 }
462
463 kfree(nlk->groups);
464 nlk->groups = NULL;
465
466 sock_put(sk);
467 return 0;
468 }
469
470 static int netlink_autobind(struct socket *sock)
471 {
472 struct sock *sk = sock->sk;
473 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
474 struct hlist_head *head;
475 struct sock *osk;
476 struct hlist_node *node;
477 s32 pid = current->pid;
478 int err;
479 static s32 rover = -4097;
480
481 retry:
482 cond_resched();
483 netlink_table_grab();
484 head = nl_pid_hashfn(hash, pid);
485 sk_for_each(osk, node, head) {
486 if (nlk_sk(osk)->pid == pid) {
487 /* Bind collision, search negative pid values. */
488 pid = rover--;
489 if (rover > -4097)
490 rover = -4097;
491 netlink_table_ungrab();
492 goto retry;
493 }
494 }
495 netlink_table_ungrab();
496
497 err = netlink_insert(sk, pid);
498 if (err == -EADDRINUSE)
499 goto retry;
500
501 /* If 2 threads race to autobind, that is fine. */
502 if (err == -EBUSY)
503 err = 0;
504
505 return err;
506 }
507
508 static inline int netlink_capable(struct socket *sock, unsigned int flag)
509 {
510 return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) ||
511 capable(CAP_NET_ADMIN);
512 }
513
514 static void
515 netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions)
516 {
517 struct netlink_sock *nlk = nlk_sk(sk);
518
519 if (nlk->subscriptions && !subscriptions)
520 __sk_del_bind_node(sk);
521 else if (!nlk->subscriptions && subscriptions)
522 sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
523 nlk->subscriptions = subscriptions;
524 }
525
526 static int netlink_alloc_groups(struct sock *sk)
527 {
528 struct netlink_sock *nlk = nlk_sk(sk);
529 unsigned int groups;
530 int err = 0;
531
532 netlink_lock_table();
533 groups = nl_table[sk->sk_protocol].groups;
534 if (!nl_table[sk->sk_protocol].registered)
535 err = -ENOENT;
536 netlink_unlock_table();
537
538 if (err)
539 return err;
540
541 nlk->groups = kmalloc(NLGRPSZ(groups), GFP_KERNEL);
542 if (nlk->groups == NULL)
543 return -ENOMEM;
544 memset(nlk->groups, 0, NLGRPSZ(groups));
545 nlk->ngroups = groups;
546 return 0;
547 }
548
549 static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
550 {
551 struct sock *sk = sock->sk;
552 struct netlink_sock *nlk = nlk_sk(sk);
553 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
554 int err;
555
556 if (nladdr->nl_family != AF_NETLINK)
557 return -EINVAL;
558
559 /* Only superuser is allowed to listen multicasts */
560 if (nladdr->nl_groups) {
561 if (!netlink_capable(sock, NL_NONROOT_RECV))
562 return -EPERM;
563 if (nlk->groups == NULL) {
564 err = netlink_alloc_groups(sk);
565 if (err)
566 return err;
567 }
568 }
569
570 if (nlk->pid) {
571 if (nladdr->nl_pid != nlk->pid)
572 return -EINVAL;
573 } else {
574 err = nladdr->nl_pid ?
575 netlink_insert(sk, nladdr->nl_pid) :
576 netlink_autobind(sock);
577 if (err)
578 return err;
579 }
580
581 if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
582 return 0;
583
584 netlink_table_grab();
585 netlink_update_subscriptions(sk, nlk->subscriptions +
586 hweight32(nladdr->nl_groups) -
587 hweight32(nlk->groups[0]));
588 nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups;
589 netlink_table_ungrab();
590
591 return 0;
592 }
593
594 static int netlink_connect(struct socket *sock, struct sockaddr *addr,
595 int alen, int flags)
596 {
597 int err = 0;
598 struct sock *sk = sock->sk;
599 struct netlink_sock *nlk = nlk_sk(sk);
600 struct sockaddr_nl *nladdr=(struct sockaddr_nl*)addr;
601
602 if (addr->sa_family == AF_UNSPEC) {
603 sk->sk_state = NETLINK_UNCONNECTED;
604 nlk->dst_pid = 0;
605 nlk->dst_group = 0;
606 return 0;
607 }
608 if (addr->sa_family != AF_NETLINK)
609 return -EINVAL;
610
611 /* Only superuser is allowed to send multicasts */
612 if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND))
613 return -EPERM;
614
615 if (!nlk->pid)
616 err = netlink_autobind(sock);
617
618 if (err == 0) {
619 sk->sk_state = NETLINK_CONNECTED;
620 nlk->dst_pid = nladdr->nl_pid;
621 nlk->dst_group = ffs(nladdr->nl_groups);
622 }
623
624 return err;
625 }
626
627 static int netlink_getname(struct socket *sock, struct sockaddr *addr, int *addr_len, int peer)
628 {
629 struct sock *sk = sock->sk;
630 struct netlink_sock *nlk = nlk_sk(sk);
631 struct sockaddr_nl *nladdr=(struct sockaddr_nl *)addr;
632
633 nladdr->nl_family = AF_NETLINK;
634 nladdr->nl_pad = 0;
635 *addr_len = sizeof(*nladdr);
636
637 if (peer) {
638 nladdr->nl_pid = nlk->dst_pid;
639 nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
640 } else {
641 nladdr->nl_pid = nlk->pid;
642 nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
643 }
644 return 0;
645 }
646
647 static void netlink_overrun(struct sock *sk)
648 {
649 if (!test_and_set_bit(0, &nlk_sk(sk)->state)) {
650 sk->sk_err = ENOBUFS;
651 sk->sk_error_report(sk);
652 }
653 }
654
655 static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid)
656 {
657 int protocol = ssk->sk_protocol;
658 struct sock *sock;
659 struct netlink_sock *nlk;
660
661 sock = netlink_lookup(protocol, pid);
662 if (!sock)
663 return ERR_PTR(-ECONNREFUSED);
664
665 /* Don't bother queuing skb if kernel socket has no input function */
666 nlk = nlk_sk(sock);
667 if ((nlk->pid == 0 && !nlk->data_ready) ||
668 (sock->sk_state == NETLINK_CONNECTED &&
669 nlk->dst_pid != nlk_sk(ssk)->pid)) {
670 sock_put(sock);
671 return ERR_PTR(-ECONNREFUSED);
672 }
673 return sock;
674 }
675
676 struct sock *netlink_getsockbyfilp(struct file *filp)
677 {
678 struct inode *inode = filp->f_dentry->d_inode;
679 struct sock *sock;
680
681 if (!S_ISSOCK(inode->i_mode))
682 return ERR_PTR(-ENOTSOCK);
683
684 sock = SOCKET_I(inode)->sk;
685 if (sock->sk_family != AF_NETLINK)
686 return ERR_PTR(-EINVAL);
687
688 sock_hold(sock);
689 return sock;
690 }
691
692 /*
693 * Attach a skb to a netlink socket.
694 * The caller must hold a reference to the destination socket. On error, the
695 * reference is dropped. The skb is not send to the destination, just all
696 * all error checks are performed and memory in the queue is reserved.
697 * Return values:
698 * < 0: error. skb freed, reference to sock dropped.
699 * 0: continue
700 * 1: repeat lookup - reference dropped while waiting for socket memory.
701 */
702 int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock, long timeo)
703 {
704 struct netlink_sock *nlk;
705
706 nlk = nlk_sk(sk);
707
708 if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
709 test_bit(0, &nlk->state)) {
710 DECLARE_WAITQUEUE(wait, current);
711 if (!timeo) {
712 if (!nlk->pid)
713 netlink_overrun(sk);
714 sock_put(sk);
715 kfree_skb(skb);
716 return -EAGAIN;
717 }
718
719 __set_current_state(TASK_INTERRUPTIBLE);
720 add_wait_queue(&nlk->wait, &wait);
721
722 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
723 test_bit(0, &nlk->state)) &&
724 !sock_flag(sk, SOCK_DEAD))
725 timeo = schedule_timeout(timeo);
726
727 __set_current_state(TASK_RUNNING);
728 remove_wait_queue(&nlk->wait, &wait);
729 sock_put(sk);
730
731 if (signal_pending(current)) {
732 kfree_skb(skb);
733 return sock_intr_errno(timeo);
734 }
735 return 1;
736 }
737 skb_set_owner_r(skb, sk);
738 return 0;
739 }
740
741 int netlink_sendskb(struct sock *sk, struct sk_buff *skb, int protocol)
742 {
743 struct netlink_sock *nlk;
744 int len = skb->len;
745
746 nlk = nlk_sk(sk);
747
748 skb_queue_tail(&sk->sk_receive_queue, skb);
749 sk->sk_data_ready(sk, len);
750 sock_put(sk);
751 return len;
752 }
753
754 void netlink_detachskb(struct sock *sk, struct sk_buff *skb)
755 {
756 kfree_skb(skb);
757 sock_put(sk);
758 }
759
760 static inline struct sk_buff *netlink_trim(struct sk_buff *skb,
761 gfp_t allocation)
762 {
763 int delta;
764
765 skb_orphan(skb);
766
767 delta = skb->end - skb->tail;
768 if (delta * 2 < skb->truesize)
769 return skb;
770
771 if (skb_shared(skb)) {
772 struct sk_buff *nskb = skb_clone(skb, allocation);
773 if (!nskb)
774 return skb;
775 kfree_skb(skb);
776 skb = nskb;
777 }
778
779 if (!pskb_expand_head(skb, 0, -delta, allocation))
780 skb->truesize -= delta;
781
782 return skb;
783 }
784
785 int netlink_unicast(struct sock *ssk, struct sk_buff *skb, u32 pid, int nonblock)
786 {
787 struct sock *sk;
788 int err;
789 long timeo;
790
791 skb = netlink_trim(skb, gfp_any());
792
793 timeo = sock_sndtimeo(ssk, nonblock);
794 retry:
795 sk = netlink_getsockbypid(ssk, pid);
796 if (IS_ERR(sk)) {
797 kfree_skb(skb);
798 return PTR_ERR(sk);
799 }
800 err = netlink_attachskb(sk, skb, nonblock, timeo);
801 if (err == 1)
802 goto retry;
803 if (err)
804 return err;
805
806 return netlink_sendskb(sk, skb, ssk->sk_protocol);
807 }
808
809 static __inline__ int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb)
810 {
811 struct netlink_sock *nlk = nlk_sk(sk);
812
813 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
814 !test_bit(0, &nlk->state)) {
815 skb_set_owner_r(skb, sk);
816 skb_queue_tail(&sk->sk_receive_queue, skb);
817 sk->sk_data_ready(sk, skb->len);
818 return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf;
819 }
820 return -1;
821 }
822
823 struct netlink_broadcast_data {
824 struct sock *exclude_sk;
825 u32 pid;
826 u32 group;
827 int failure;
828 int congested;
829 int delivered;
830 unsigned int allocation;
831 struct sk_buff *skb, *skb2;
832 };
833
834 static inline int do_one_broadcast(struct sock *sk,
835 struct netlink_broadcast_data *p)
836 {
837 struct netlink_sock *nlk = nlk_sk(sk);
838 int val;
839
840 if (p->exclude_sk == sk)
841 goto out;
842
843 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
844 !test_bit(p->group - 1, nlk->groups))
845 goto out;
846
847 if (p->failure) {
848 netlink_overrun(sk);
849 goto out;
850 }
851
852 sock_hold(sk);
853 if (p->skb2 == NULL) {
854 if (skb_shared(p->skb)) {
855 p->skb2 = skb_clone(p->skb, p->allocation);
856 } else {
857 p->skb2 = skb_get(p->skb);
858 /*
859 * skb ownership may have been set when
860 * delivered to a previous socket.
861 */
862 skb_orphan(p->skb2);
863 }
864 }
865 if (p->skb2 == NULL) {
866 netlink_overrun(sk);
867 /* Clone failed. Notify ALL listeners. */
868 p->failure = 1;
869 } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) {
870 netlink_overrun(sk);
871 } else {
872 p->congested |= val;
873 p->delivered = 1;
874 p->skb2 = NULL;
875 }
876 sock_put(sk);
877
878 out:
879 return 0;
880 }
881
882 int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
883 u32 group, gfp_t allocation)
884 {
885 struct netlink_broadcast_data info;
886 struct hlist_node *node;
887 struct sock *sk;
888
889 skb = netlink_trim(skb, allocation);
890
891 info.exclude_sk = ssk;
892 info.pid = pid;
893 info.group = group;
894 info.failure = 0;
895 info.congested = 0;
896 info.delivered = 0;
897 info.allocation = allocation;
898 info.skb = skb;
899 info.skb2 = NULL;
900
901 /* While we sleep in clone, do not allow to change socket list */
902
903 netlink_lock_table();
904
905 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
906 do_one_broadcast(sk, &info);
907
908 kfree_skb(skb);
909
910 netlink_unlock_table();
911
912 if (info.skb2)
913 kfree_skb(info.skb2);
914
915 if (info.delivered) {
916 if (info.congested && (allocation & __GFP_WAIT))
917 yield();
918 return 0;
919 }
920 if (info.failure)
921 return -ENOBUFS;
922 return -ESRCH;
923 }
924
925 struct netlink_set_err_data {
926 struct sock *exclude_sk;
927 u32 pid;
928 u32 group;
929 int code;
930 };
931
932 static inline int do_one_set_err(struct sock *sk,
933 struct netlink_set_err_data *p)
934 {
935 struct netlink_sock *nlk = nlk_sk(sk);
936
937 if (sk == p->exclude_sk)
938 goto out;
939
940 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
941 !test_bit(p->group - 1, nlk->groups))
942 goto out;
943
944 sk->sk_err = p->code;
945 sk->sk_error_report(sk);
946 out:
947 return 0;
948 }
949
950 void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code)
951 {
952 struct netlink_set_err_data info;
953 struct hlist_node *node;
954 struct sock *sk;
955
956 info.exclude_sk = ssk;
957 info.pid = pid;
958 info.group = group;
959 info.code = code;
960
961 read_lock(&nl_table_lock);
962
963 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
964 do_one_set_err(sk, &info);
965
966 read_unlock(&nl_table_lock);
967 }
968
969 static int netlink_setsockopt(struct socket *sock, int level, int optname,
970 char __user *optval, int optlen)
971 {
972 struct sock *sk = sock->sk;
973 struct netlink_sock *nlk = nlk_sk(sk);
974 int val = 0, err;
975
976 if (level != SOL_NETLINK)
977 return -ENOPROTOOPT;
978
979 if (optlen >= sizeof(int) &&
980 get_user(val, (int __user *)optval))
981 return -EFAULT;
982
983 switch (optname) {
984 case NETLINK_PKTINFO:
985 if (val)
986 nlk->flags |= NETLINK_RECV_PKTINFO;
987 else
988 nlk->flags &= ~NETLINK_RECV_PKTINFO;
989 err = 0;
990 break;
991 case NETLINK_ADD_MEMBERSHIP:
992 case NETLINK_DROP_MEMBERSHIP: {
993 unsigned int subscriptions;
994 int old, new = optname == NETLINK_ADD_MEMBERSHIP ? 1 : 0;
995
996 if (!netlink_capable(sock, NL_NONROOT_RECV))
997 return -EPERM;
998 if (nlk->groups == NULL) {
999 err = netlink_alloc_groups(sk);
1000 if (err)
1001 return err;
1002 }
1003 if (!val || val - 1 >= nlk->ngroups)
1004 return -EINVAL;
1005 netlink_table_grab();
1006 old = test_bit(val - 1, nlk->groups);
1007 subscriptions = nlk->subscriptions - old + new;
1008 if (new)
1009 __set_bit(val - 1, nlk->groups);
1010 else
1011 __clear_bit(val - 1, nlk->groups);
1012 netlink_update_subscriptions(sk, subscriptions);
1013 netlink_table_ungrab();
1014 err = 0;
1015 break;
1016 }
1017 default:
1018 err = -ENOPROTOOPT;
1019 }
1020 return err;
1021 }
1022
1023 static int netlink_getsockopt(struct socket *sock, int level, int optname,
1024 char __user *optval, int __user *optlen)
1025 {
1026 struct sock *sk = sock->sk;
1027 struct netlink_sock *nlk = nlk_sk(sk);
1028 int len, val, err;
1029
1030 if (level != SOL_NETLINK)
1031 return -ENOPROTOOPT;
1032
1033 if (get_user(len, optlen))
1034 return -EFAULT;
1035 if (len < 0)
1036 return -EINVAL;
1037
1038 switch (optname) {
1039 case NETLINK_PKTINFO:
1040 if (len < sizeof(int))
1041 return -EINVAL;
1042 len = sizeof(int);
1043 val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0;
1044 put_user(len, optlen);
1045 put_user(val, optval);
1046 err = 0;
1047 break;
1048 default:
1049 err = -ENOPROTOOPT;
1050 }
1051 return err;
1052 }
1053
1054 static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
1055 {
1056 struct nl_pktinfo info;
1057
1058 info.group = NETLINK_CB(skb).dst_group;
1059 put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info);
1060 }
1061
1062 static inline void netlink_rcv_wake(struct sock *sk)
1063 {
1064 struct netlink_sock *nlk = nlk_sk(sk);
1065
1066 if (skb_queue_empty(&sk->sk_receive_queue))
1067 clear_bit(0, &nlk->state);
1068 if (!test_bit(0, &nlk->state))
1069 wake_up_interruptible(&nlk->wait);
1070 }
1071
1072 static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
1073 struct msghdr *msg, size_t len)
1074 {
1075 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1076 struct sock *sk = sock->sk;
1077 struct netlink_sock *nlk = nlk_sk(sk);
1078 struct sockaddr_nl *addr=msg->msg_name;
1079 u32 dst_pid;
1080 u32 dst_group;
1081 struct sk_buff *skb;
1082 int err;
1083 struct scm_cookie scm;
1084
1085 if (msg->msg_flags&MSG_OOB)
1086 return -EOPNOTSUPP;
1087
1088 if (NULL == siocb->scm)
1089 siocb->scm = &scm;
1090 err = scm_send(sock, msg, siocb->scm);
1091 if (err < 0)
1092 return err;
1093
1094 if (msg->msg_namelen) {
1095 if (addr->nl_family != AF_NETLINK)
1096 return -EINVAL;
1097 dst_pid = addr->nl_pid;
1098 dst_group = ffs(addr->nl_groups);
1099 if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND))
1100 return -EPERM;
1101 } else {
1102 dst_pid = nlk->dst_pid;
1103 dst_group = nlk->dst_group;
1104 }
1105
1106 if (!nlk->pid) {
1107 err = netlink_autobind(sock);
1108 if (err)
1109 goto out;
1110 }
1111
1112 err = -EMSGSIZE;
1113 if (len > sk->sk_sndbuf - 32)
1114 goto out;
1115 err = -ENOBUFS;
1116 skb = alloc_skb(len, GFP_KERNEL);
1117 if (skb==NULL)
1118 goto out;
1119
1120 NETLINK_CB(skb).pid = nlk->pid;
1121 NETLINK_CB(skb).dst_pid = dst_pid;
1122 NETLINK_CB(skb).dst_group = dst_group;
1123 NETLINK_CB(skb).loginuid = audit_get_loginuid(current->audit_context);
1124 memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1125
1126 /* What can I do? Netlink is asynchronous, so that
1127 we will have to save current capabilities to
1128 check them, when this message will be delivered
1129 to corresponding kernel module. --ANK (980802)
1130 */
1131
1132 err = -EFAULT;
1133 if (memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len)) {
1134 kfree_skb(skb);
1135 goto out;
1136 }
1137
1138 err = security_netlink_send(sk, skb);
1139 if (err) {
1140 kfree_skb(skb);
1141 goto out;
1142 }
1143
1144 if (dst_group) {
1145 atomic_inc(&skb->users);
1146 netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL);
1147 }
1148 err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT);
1149
1150 out:
1151 return err;
1152 }
1153
1154 static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
1155 struct msghdr *msg, size_t len,
1156 int flags)
1157 {
1158 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1159 struct scm_cookie scm;
1160 struct sock *sk = sock->sk;
1161 struct netlink_sock *nlk = nlk_sk(sk);
1162 int noblock = flags&MSG_DONTWAIT;
1163 size_t copied;
1164 struct sk_buff *skb;
1165 int err;
1166
1167 if (flags&MSG_OOB)
1168 return -EOPNOTSUPP;
1169
1170 copied = 0;
1171
1172 skb = skb_recv_datagram(sk,flags,noblock,&err);
1173 if (skb==NULL)
1174 goto out;
1175
1176 msg->msg_namelen = 0;
1177
1178 copied = skb->len;
1179 if (len < copied) {
1180 msg->msg_flags |= MSG_TRUNC;
1181 copied = len;
1182 }
1183
1184 skb->h.raw = skb->data;
1185 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
1186
1187 if (msg->msg_name) {
1188 struct sockaddr_nl *addr = (struct sockaddr_nl*)msg->msg_name;
1189 addr->nl_family = AF_NETLINK;
1190 addr->nl_pad = 0;
1191 addr->nl_pid = NETLINK_CB(skb).pid;
1192 addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group);
1193 msg->msg_namelen = sizeof(*addr);
1194 }
1195
1196 if (NULL == siocb->scm) {
1197 memset(&scm, 0, sizeof(scm));
1198 siocb->scm = &scm;
1199 }
1200 siocb->scm->creds = *NETLINK_CREDS(skb);
1201 skb_free_datagram(sk, skb);
1202
1203 if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2)
1204 netlink_dump(sk);
1205
1206 scm_recv(sock, msg, siocb->scm, flags);
1207 if (nlk->flags & NETLINK_RECV_PKTINFO)
1208 netlink_cmsg_recv_pktinfo(msg, skb);
1209
1210 out:
1211 netlink_rcv_wake(sk);
1212 return err ? : copied;
1213 }
1214
1215 static void netlink_data_ready(struct sock *sk, int len)
1216 {
1217 struct netlink_sock *nlk = nlk_sk(sk);
1218
1219 if (nlk->data_ready)
1220 nlk->data_ready(sk, len);
1221 netlink_rcv_wake(sk);
1222 }
1223
1224 /*
1225 * We export these functions to other modules. They provide a
1226 * complete set of kernel non-blocking support for message
1227 * queueing.
1228 */
1229
1230 struct sock *
1231 netlink_kernel_create(int unit, unsigned int groups,
1232 void (*input)(struct sock *sk, int len),
1233 struct module *module)
1234 {
1235 struct socket *sock;
1236 struct sock *sk;
1237 struct netlink_sock *nlk;
1238
1239 if (!nl_table)
1240 return NULL;
1241
1242 if (unit<0 || unit>=MAX_LINKS)
1243 return NULL;
1244
1245 if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
1246 return NULL;
1247
1248 if (__netlink_create(sock, unit) < 0)
1249 goto out_sock_release;
1250
1251 sk = sock->sk;
1252 sk->sk_data_ready = netlink_data_ready;
1253 if (input)
1254 nlk_sk(sk)->data_ready = input;
1255
1256 if (netlink_insert(sk, 0))
1257 goto out_sock_release;
1258
1259 nlk = nlk_sk(sk);
1260 nlk->flags |= NETLINK_KERNEL_SOCKET;
1261
1262 netlink_table_grab();
1263 nl_table[unit].groups = groups < 32 ? 32 : groups;
1264 nl_table[unit].module = module;
1265 nl_table[unit].registered = 1;
1266 netlink_table_ungrab();
1267
1268 return sk;
1269
1270 out_sock_release:
1271 sock_release(sock);
1272 return NULL;
1273 }
1274
1275 void netlink_set_nonroot(int protocol, unsigned int flags)
1276 {
1277 if ((unsigned int)protocol < MAX_LINKS)
1278 nl_table[protocol].nl_nonroot = flags;
1279 }
1280
1281 static void netlink_destroy_callback(struct netlink_callback *cb)
1282 {
1283 if (cb->skb)
1284 kfree_skb(cb->skb);
1285 kfree(cb);
1286 }
1287
1288 /*
1289 * It looks a bit ugly.
1290 * It would be better to create kernel thread.
1291 */
1292
1293 static int netlink_dump(struct sock *sk)
1294 {
1295 struct netlink_sock *nlk = nlk_sk(sk);
1296 struct netlink_callback *cb;
1297 struct sk_buff *skb;
1298 struct nlmsghdr *nlh;
1299 int len;
1300
1301 skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL);
1302 if (!skb)
1303 return -ENOBUFS;
1304
1305 spin_lock(&nlk->cb_lock);
1306
1307 cb = nlk->cb;
1308 if (cb == NULL) {
1309 spin_unlock(&nlk->cb_lock);
1310 kfree_skb(skb);
1311 return -EINVAL;
1312 }
1313
1314 len = cb->dump(skb, cb);
1315
1316 if (len > 0) {
1317 spin_unlock(&nlk->cb_lock);
1318 skb_queue_tail(&sk->sk_receive_queue, skb);
1319 sk->sk_data_ready(sk, len);
1320 return 0;
1321 }
1322
1323 nlh = NLMSG_NEW_ANSWER(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI);
1324 memcpy(NLMSG_DATA(nlh), &len, sizeof(len));
1325 skb_queue_tail(&sk->sk_receive_queue, skb);
1326 sk->sk_data_ready(sk, skb->len);
1327
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
1416 #ifdef CONFIG_PROC_FS
1417 struct nl_seq_iter {
1418 int link;
1419 int hash_idx;
1420 };
1421
1422 static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos)
1423 {
1424 struct nl_seq_iter *iter = seq->private;
1425 int i, j;
1426 struct sock *s;
1427 struct hlist_node *node;
1428 loff_t off = 0;
1429
1430 for (i=0; i<MAX_LINKS; i++) {
1431 struct nl_pid_hash *hash = &nl_table[i].hash;
1432
1433 for (j = 0; j <= hash->mask; j++) {
1434 sk_for_each(s, node, &hash->table[j]) {
1435 if (off == pos) {
1436 iter->link = i;
1437 iter->hash_idx = j;
1438 return s;
1439 }
1440 ++off;
1441 }
1442 }
1443 }
1444 return NULL;
1445 }
1446
1447 static void *netlink_seq_start(struct seq_file *seq, loff_t *pos)
1448 {
1449 read_lock(&nl_table_lock);
1450 return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN;
1451 }
1452
1453 static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1454 {
1455 struct sock *s;
1456 struct nl_seq_iter *iter;
1457 int i, j;
1458
1459 ++*pos;
1460
1461 if (v == SEQ_START_TOKEN)
1462 return netlink_seq_socket_idx(seq, 0);
1463
1464 s = sk_next(v);
1465 if (s)
1466 return s;
1467
1468 iter = seq->private;
1469 i = iter->link;
1470 j = iter->hash_idx + 1;
1471
1472 do {
1473 struct nl_pid_hash *hash = &nl_table[i].hash;
1474
1475 for (; j <= hash->mask; j++) {
1476 s = sk_head(&hash->table[j]);
1477 if (s) {
1478 iter->link = i;
1479 iter->hash_idx = j;
1480 return s;
1481 }
1482 }
1483
1484 j = 0;
1485 } while (++i < MAX_LINKS);
1486
1487 return NULL;
1488 }
1489
1490 static void netlink_seq_stop(struct seq_file *seq, void *v)
1491 {
1492 read_unlock(&nl_table_lock);
1493 }
1494
1495
1496 static int netlink_seq_show(struct seq_file *seq, void *v)
1497 {
1498 if (v == SEQ_START_TOKEN)
1499 seq_puts(seq,
1500 "sk Eth Pid Groups "
1501 "Rmem Wmem Dump Locks\n");
1502 else {
1503 struct sock *s = v;
1504 struct netlink_sock *nlk = nlk_sk(s);
1505
1506 seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %d\n",
1507 s,
1508 s->sk_protocol,
1509 nlk->pid,
1510 nlk->groups ? (u32)nlk->groups[0] : 0,
1511 atomic_read(&s->sk_rmem_alloc),
1512 atomic_read(&s->sk_wmem_alloc),
1513 nlk->cb,
1514 atomic_read(&s->sk_refcnt)
1515 );
1516
1517 }
1518 return 0;
1519 }
1520
1521 static struct seq_operations netlink_seq_ops = {
1522 .start = netlink_seq_start,
1523 .next = netlink_seq_next,
1524 .stop = netlink_seq_stop,
1525 .show = netlink_seq_show,
1526 };
1527
1528
1529 static int netlink_seq_open(struct inode *inode, struct file *file)
1530 {
1531 struct seq_file *seq;
1532 struct nl_seq_iter *iter;
1533 int err;
1534
1535 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
1536 if (!iter)
1537 return -ENOMEM;
1538
1539 err = seq_open(file, &netlink_seq_ops);
1540 if (err) {
1541 kfree(iter);
1542 return err;
1543 }
1544
1545 memset(iter, 0, sizeof(*iter));
1546 seq = file->private_data;
1547 seq->private = iter;
1548 return 0;
1549 }
1550
1551 static struct file_operations netlink_seq_fops = {
1552 .owner = THIS_MODULE,
1553 .open = netlink_seq_open,
1554 .read = seq_read,
1555 .llseek = seq_lseek,
1556 .release = seq_release_private,
1557 };
1558
1559 #endif
1560
1561 int netlink_register_notifier(struct notifier_block *nb)
1562 {
1563 return notifier_chain_register(&netlink_chain, nb);
1564 }
1565
1566 int netlink_unregister_notifier(struct notifier_block *nb)
1567 {
1568 return notifier_chain_unregister(&netlink_chain, nb);
1569 }
1570
1571 static struct proto_ops netlink_ops = {
1572 .family = PF_NETLINK,
1573 .owner = THIS_MODULE,
1574 .release = netlink_release,
1575 .bind = netlink_bind,
1576 .connect = netlink_connect,
1577 .socketpair = sock_no_socketpair,
1578 .accept = sock_no_accept,
1579 .getname = netlink_getname,
1580 .poll = datagram_poll,
1581 .ioctl = sock_no_ioctl,
1582 .listen = sock_no_listen,
1583 .shutdown = sock_no_shutdown,
1584 .setsockopt = netlink_setsockopt,
1585 .getsockopt = netlink_getsockopt,
1586 .sendmsg = netlink_sendmsg,
1587 .recvmsg = netlink_recvmsg,
1588 .mmap = sock_no_mmap,
1589 .sendpage = sock_no_sendpage,
1590 };
1591
1592 static struct net_proto_family netlink_family_ops = {
1593 .family = PF_NETLINK,
1594 .create = netlink_create,
1595 .owner = THIS_MODULE, /* for consistency 8) */
1596 };
1597
1598 extern void netlink_skb_parms_too_large(void);
1599
1600 static int __init netlink_proto_init(void)
1601 {
1602 struct sk_buff *dummy_skb;
1603 int i;
1604 unsigned long max;
1605 unsigned int order;
1606 int err = proto_register(&netlink_proto, 0);
1607
1608 if (err != 0)
1609 goto out;
1610
1611 if (sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb))
1612 netlink_skb_parms_too_large();
1613
1614 nl_table = kmalloc(sizeof(*nl_table) * MAX_LINKS, GFP_KERNEL);
1615 if (!nl_table) {
1616 enomem:
1617 printk(KERN_CRIT "netlink_init: Cannot allocate nl_table\n");
1618 return -ENOMEM;
1619 }
1620
1621 memset(nl_table, 0, sizeof(*nl_table) * MAX_LINKS);
1622
1623 if (num_physpages >= (128 * 1024))
1624 max = num_physpages >> (21 - PAGE_SHIFT);
1625 else
1626 max = num_physpages >> (23 - PAGE_SHIFT);
1627
1628 order = get_bitmask_order(max) - 1 + PAGE_SHIFT;
1629 max = (1UL << order) / sizeof(struct hlist_head);
1630 order = get_bitmask_order(max > UINT_MAX ? UINT_MAX : max) - 1;
1631
1632 for (i = 0; i < MAX_LINKS; i++) {
1633 struct nl_pid_hash *hash = &nl_table[i].hash;
1634
1635 hash->table = nl_pid_hash_alloc(1 * sizeof(*hash->table));
1636 if (!hash->table) {
1637 while (i-- > 0)
1638 nl_pid_hash_free(nl_table[i].hash.table,
1639 1 * sizeof(*hash->table));
1640 kfree(nl_table);
1641 goto enomem;
1642 }
1643 memset(hash->table, 0, 1 * sizeof(*hash->table));
1644 hash->max_shift = order;
1645 hash->shift = 0;
1646 hash->mask = 0;
1647 hash->rehash_time = jiffies;
1648 }
1649
1650 sock_register(&netlink_family_ops);
1651 #ifdef CONFIG_PROC_FS
1652 proc_net_fops_create("netlink", 0, &netlink_seq_fops);
1653 #endif
1654 /* The netlink device handler may be needed early. */
1655 rtnetlink_init();
1656 out:
1657 return err;
1658 }
1659
1660 core_initcall(netlink_proto_init);
1661
1662 EXPORT_SYMBOL(netlink_ack);
1663 EXPORT_SYMBOL(netlink_broadcast);
1664 EXPORT_SYMBOL(netlink_dump_start);
1665 EXPORT_SYMBOL(netlink_kernel_create);
1666 EXPORT_SYMBOL(netlink_register_notifier);
1667 EXPORT_SYMBOL(netlink_set_err);
1668 EXPORT_SYMBOL(netlink_set_nonroot);
1669 EXPORT_SYMBOL(netlink_unicast);
1670 EXPORT_SYMBOL(netlink_unregister_notifier);
1671
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