blob: 712a7bff8560c70196c3efc7ac9fc4b165d92f5c [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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.
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +090011 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070012 * 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)
Harald Welte4fdb3bb2005-08-09 19:40:55 -070016 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070022 */
23
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/module.h>
25
Randy Dunlap4fc268d2006-01-11 12:17:47 -080026#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <linux/kernel.h>
28#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070048#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>
Andrew Morton54e0f522005-04-30 07:07:04 +010056#include <linux/audit.h>
Steve Grubbe7c34972006-04-03 09:08:13 -040057#include <linux/selinux.h>
Patrick McHardyaf65bdf2007-04-20 14:14:21 -070058#include <linux/mutex.h>
Andrew Morton54e0f522005-04-30 07:07:04 +010059
Eric W. Biederman457c4cb2007-09-12 12:01:34 +020060#include <net/net_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070061#include <net/sock.h>
62#include <net/scm.h>
Thomas Graf82ace472005-11-10 02:25:53 +010063#include <net/netlink.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
Patrick McHardyf7fa9b12005-08-15 12:29:13 -070065#define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8)
Johannes Bergb4ff4f02007-07-18 15:46:06 -070066#define NLGRPLONGS(x) (NLGRPSZ(x)/sizeof(unsigned long))
Linus Torvalds1da177e2005-04-16 15:20:36 -070067
68struct netlink_sock {
69 /* struct sock has to be the first member of netlink_sock */
70 struct sock sk;
71 u32 pid;
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 u32 dst_pid;
Patrick McHardyd629b832005-08-14 19:27:50 -070073 u32 dst_group;
Patrick McHardyf7fa9b12005-08-15 12:29:13 -070074 u32 flags;
75 u32 subscriptions;
76 u32 ngroups;
77 unsigned long *groups;
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 unsigned long state;
79 wait_queue_head_t wait;
80 struct netlink_callback *cb;
Patrick McHardyaf65bdf2007-04-20 14:14:21 -070081 struct mutex *cb_mutex;
82 struct mutex cb_def_mutex;
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -070083 void (*netlink_rcv)(struct sk_buff *skb);
Patrick McHardy77247bb2005-08-14 19:27:13 -070084 struct module *module;
Linus Torvalds1da177e2005-04-16 15:20:36 -070085};
86
Patrick McHardy77247bb2005-08-14 19:27:13 -070087#define NETLINK_KERNEL_SOCKET 0x1
Patrick McHardy9a4595b2005-08-15 12:32:15 -070088#define NETLINK_RECV_PKTINFO 0x2
Patrick McHardy77247bb2005-08-14 19:27:13 -070089
Linus Torvalds1da177e2005-04-16 15:20:36 -070090static inline struct netlink_sock *nlk_sk(struct sock *sk)
91{
Denis Cheng32b21e02007-08-28 15:41:11 -070092 return container_of(sk, struct netlink_sock, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093}
94
Denis V. Lunevaed81562007-10-10 21:14:32 -070095static inline int netlink_is_kernel(struct sock *sk)
96{
97 return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET;
98}
99
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100struct nl_pid_hash {
101 struct hlist_head *table;
102 unsigned long rehash_time;
103
104 unsigned int mask;
105 unsigned int shift;
106
107 unsigned int entries;
108 unsigned int max_shift;
109
110 u32 rnd;
111};
112
113struct netlink_table {
114 struct nl_pid_hash hash;
115 struct hlist_head mc_list;
Patrick McHardy4277a082006-03-20 18:52:01 -0800116 unsigned long *listeners;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 unsigned int nl_nonroot;
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700118 unsigned int groups;
Patrick McHardyaf65bdf2007-04-20 14:14:21 -0700119 struct mutex *cb_mutex;
Patrick McHardy77247bb2005-08-14 19:27:13 -0700120 struct module *module;
Patrick McHardyab33a172005-08-14 19:31:36 -0700121 int registered;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122};
123
124static struct netlink_table *nl_table;
125
126static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
127
128static int netlink_dump(struct sock *sk);
129static void netlink_destroy_callback(struct netlink_callback *cb);
130
131static DEFINE_RWLOCK(nl_table_lock);
132static atomic_t nl_table_users = ATOMIC_INIT(0);
133
Alan Sterne041c682006-03-27 01:16:30 -0800134static ATOMIC_NOTIFIER_HEAD(netlink_chain);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135
Patrick McHardyd629b832005-08-14 19:27:50 -0700136static u32 netlink_group_mask(u32 group)
137{
138 return group ? 1 << (group - 1) : 0;
139}
140
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid)
142{
143 return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask];
144}
145
146static void netlink_sock_destruct(struct sock *sk)
147{
Herbert Xu3f660d62007-05-03 03:17:14 -0700148 struct netlink_sock *nlk = nlk_sk(sk);
149
Herbert Xu3f660d62007-05-03 03:17:14 -0700150 if (nlk->cb) {
151 if (nlk->cb->done)
152 nlk->cb->done(nlk->cb);
153 netlink_destroy_callback(nlk->cb);
154 }
155
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 skb_queue_purge(&sk->sk_receive_queue);
157
158 if (!sock_flag(sk, SOCK_DEAD)) {
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800159 printk(KERN_ERR "Freeing alive netlink socket %p\n", sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 return;
161 }
162 BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc));
163 BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700164 BUG_TRAP(!nlk_sk(sk)->groups);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165}
166
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800167/* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on
168 * SMP. Look, when several writers sleep and reader wakes them up, all but one
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 * immediately hit write lock and grab all the cpus. Exclusive sleep solves
170 * this, _but_ remember, it adds useless work on UP machines.
171 */
172
173static void netlink_table_grab(void)
Eric Dumazet9a429c42008-01-01 21:58:02 -0800174 __acquires(nl_table_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175{
Arjan van de Ven6abd2192006-07-03 00:24:07 -0700176 write_lock_irq(&nl_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177
178 if (atomic_read(&nl_table_users)) {
179 DECLARE_WAITQUEUE(wait, current);
180
181 add_wait_queue_exclusive(&nl_table_wait, &wait);
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800182 for (;;) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 set_current_state(TASK_UNINTERRUPTIBLE);
184 if (atomic_read(&nl_table_users) == 0)
185 break;
Arjan van de Ven6abd2192006-07-03 00:24:07 -0700186 write_unlock_irq(&nl_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 schedule();
Arjan van de Ven6abd2192006-07-03 00:24:07 -0700188 write_lock_irq(&nl_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 }
190
191 __set_current_state(TASK_RUNNING);
192 remove_wait_queue(&nl_table_wait, &wait);
193 }
194}
195
Ilpo Järvinen3f252522008-01-12 03:21:50 -0800196static void netlink_table_ungrab(void)
Eric Dumazet9a429c42008-01-01 21:58:02 -0800197 __releases(nl_table_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198{
Arjan van de Ven6abd2192006-07-03 00:24:07 -0700199 write_unlock_irq(&nl_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 wake_up(&nl_table_wait);
201}
202
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800203static inline void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204netlink_lock_table(void)
205{
206 /* read_lock() synchronizes us to netlink_table_grab */
207
208 read_lock(&nl_table_lock);
209 atomic_inc(&nl_table_users);
210 read_unlock(&nl_table_lock);
211}
212
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800213static inline void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214netlink_unlock_table(void)
215{
216 if (atomic_dec_and_test(&nl_table_users))
217 wake_up(&nl_table_wait);
218}
219
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800220static inline struct sock *netlink_lookup(struct net *net, int protocol,
221 u32 pid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222{
223 struct nl_pid_hash *hash = &nl_table[protocol].hash;
224 struct hlist_head *head;
225 struct sock *sk;
226 struct hlist_node *node;
227
228 read_lock(&nl_table_lock);
229 head = nl_pid_hashfn(hash, pid);
230 sk_for_each(sk, node, head) {
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900231 if (sock_net(sk) == net && (nlk_sk(sk)->pid == pid)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 sock_hold(sk);
233 goto found;
234 }
235 }
236 sk = NULL;
237found:
238 read_unlock(&nl_table_lock);
239 return sk;
240}
241
Eric Dumazetea729122007-12-11 02:09:47 -0800242static inline struct hlist_head *nl_pid_hash_zalloc(size_t size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243{
244 if (size <= PAGE_SIZE)
Eric Dumazetea729122007-12-11 02:09:47 -0800245 return kzalloc(size, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 else
247 return (struct hlist_head *)
Eric Dumazetea729122007-12-11 02:09:47 -0800248 __get_free_pages(GFP_ATOMIC | __GFP_ZERO,
249 get_order(size));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250}
251
252static inline void nl_pid_hash_free(struct hlist_head *table, size_t size)
253{
254 if (size <= PAGE_SIZE)
255 kfree(table);
256 else
257 free_pages((unsigned long)table, get_order(size));
258}
259
260static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow)
261{
262 unsigned int omask, mask, shift;
263 size_t osize, size;
264 struct hlist_head *otable, *table;
265 int i;
266
267 omask = mask = hash->mask;
268 osize = size = (mask + 1) * sizeof(*table);
269 shift = hash->shift;
270
271 if (grow) {
272 if (++shift > hash->max_shift)
273 return 0;
274 mask = mask * 2 + 1;
275 size *= 2;
276 }
277
Eric Dumazetea729122007-12-11 02:09:47 -0800278 table = nl_pid_hash_zalloc(size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 if (!table)
280 return 0;
281
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 otable = hash->table;
283 hash->table = table;
284 hash->mask = mask;
285 hash->shift = shift;
286 get_random_bytes(&hash->rnd, sizeof(hash->rnd));
287
288 for (i = 0; i <= omask; i++) {
289 struct sock *sk;
290 struct hlist_node *node, *tmp;
291
292 sk_for_each_safe(sk, node, tmp, &otable[i])
293 __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid));
294 }
295
296 nl_pid_hash_free(otable, osize);
297 hash->rehash_time = jiffies + 10 * 60 * HZ;
298 return 1;
299}
300
301static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len)
302{
303 int avg = hash->entries >> hash->shift;
304
305 if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1))
306 return 1;
307
308 if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) {
309 nl_pid_hash_rehash(hash, 0);
310 return 1;
311 }
312
313 return 0;
314}
315
Eric Dumazet90ddc4f2005-12-22 12:49:22 -0800316static const struct proto_ops netlink_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317
Patrick McHardy4277a082006-03-20 18:52:01 -0800318static void
319netlink_update_listeners(struct sock *sk)
320{
321 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
322 struct hlist_node *node;
323 unsigned long mask;
324 unsigned int i;
325
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700326 for (i = 0; i < NLGRPLONGS(tbl->groups); i++) {
Patrick McHardy4277a082006-03-20 18:52:01 -0800327 mask = 0;
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700328 sk_for_each_bound(sk, node, &tbl->mc_list) {
329 if (i < NLGRPLONGS(nlk_sk(sk)->ngroups))
330 mask |= nlk_sk(sk)->groups[i];
331 }
Patrick McHardy4277a082006-03-20 18:52:01 -0800332 tbl->listeners[i] = mask;
333 }
334 /* this function is only called with the netlink table "grabbed", which
335 * makes sure updates are visible before bind or setsockopt return. */
336}
337
Eric W. Biedermanb4b51022007-09-12 13:05:38 +0200338static int netlink_insert(struct sock *sk, struct net *net, u32 pid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339{
340 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
341 struct hlist_head *head;
342 int err = -EADDRINUSE;
343 struct sock *osk;
344 struct hlist_node *node;
345 int len;
346
347 netlink_table_grab();
348 head = nl_pid_hashfn(hash, pid);
349 len = 0;
350 sk_for_each(osk, node, head) {
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900351 if (sock_net(osk) == net && (nlk_sk(osk)->pid == pid))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 break;
353 len++;
354 }
355 if (node)
356 goto err;
357
358 err = -EBUSY;
359 if (nlk_sk(sk)->pid)
360 goto err;
361
362 err = -ENOMEM;
363 if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX))
364 goto err;
365
366 if (len && nl_pid_hash_dilute(hash, len))
367 head = nl_pid_hashfn(hash, pid);
368 hash->entries++;
369 nlk_sk(sk)->pid = pid;
370 sk_add_node(sk, head);
371 err = 0;
372
373err:
374 netlink_table_ungrab();
375 return err;
376}
377
378static void netlink_remove(struct sock *sk)
379{
380 netlink_table_grab();
David S. Millerd470e3b2005-06-26 15:31:51 -0700381 if (sk_del_node_init(sk))
382 nl_table[sk->sk_protocol].hash.entries--;
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700383 if (nlk_sk(sk)->subscriptions)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 __sk_del_bind_node(sk);
385 netlink_table_ungrab();
386}
387
388static struct proto netlink_proto = {
389 .name = "NETLINK",
390 .owner = THIS_MODULE,
391 .obj_size = sizeof(struct netlink_sock),
392};
393
Eric W. Biederman1b8d7ae2007-10-08 23:24:22 -0700394static int __netlink_create(struct net *net, struct socket *sock,
395 struct mutex *cb_mutex, int protocol)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396{
397 struct sock *sk;
398 struct netlink_sock *nlk;
Patrick McHardyab33a172005-08-14 19:31:36 -0700399
400 sock->ops = &netlink_ops;
401
Pavel Emelyanov6257ff22007-11-01 00:39:31 -0700402 sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto);
Patrick McHardyab33a172005-08-14 19:31:36 -0700403 if (!sk)
404 return -ENOMEM;
405
406 sock_init_data(sock, sk);
407
408 nlk = nlk_sk(sk);
Patrick McHardyffa4d722007-04-25 14:01:17 -0700409 if (cb_mutex)
410 nlk->cb_mutex = cb_mutex;
411 else {
412 nlk->cb_mutex = &nlk->cb_def_mutex;
413 mutex_init(nlk->cb_mutex);
414 }
Patrick McHardyab33a172005-08-14 19:31:36 -0700415 init_waitqueue_head(&nlk->wait);
416
417 sk->sk_destruct = netlink_sock_destruct;
418 sk->sk_protocol = protocol;
419 return 0;
420}
421
Eric W. Biederman1b8d7ae2007-10-08 23:24:22 -0700422static int netlink_create(struct net *net, struct socket *sock, int protocol)
Patrick McHardyab33a172005-08-14 19:31:36 -0700423{
424 struct module *module = NULL;
Patrick McHardyaf65bdf2007-04-20 14:14:21 -0700425 struct mutex *cb_mutex;
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700426 struct netlink_sock *nlk;
Patrick McHardyab33a172005-08-14 19:31:36 -0700427 int err = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428
429 sock->state = SS_UNCONNECTED;
430
431 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
432 return -ESOCKTNOSUPPORT;
433
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800434 if (protocol < 0 || protocol >= MAX_LINKS)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 return -EPROTONOSUPPORT;
436
Patrick McHardy77247bb2005-08-14 19:27:13 -0700437 netlink_lock_table();
Harald Welte4fdb3bb2005-08-09 19:40:55 -0700438#ifdef CONFIG_KMOD
Patrick McHardyab33a172005-08-14 19:31:36 -0700439 if (!nl_table[protocol].registered) {
Patrick McHardy77247bb2005-08-14 19:27:13 -0700440 netlink_unlock_table();
Harald Welte4fdb3bb2005-08-09 19:40:55 -0700441 request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
Patrick McHardy77247bb2005-08-14 19:27:13 -0700442 netlink_lock_table();
Harald Welte4fdb3bb2005-08-09 19:40:55 -0700443 }
Patrick McHardyab33a172005-08-14 19:31:36 -0700444#endif
445 if (nl_table[protocol].registered &&
446 try_module_get(nl_table[protocol].module))
447 module = nl_table[protocol].module;
Patrick McHardyaf65bdf2007-04-20 14:14:21 -0700448 cb_mutex = nl_table[protocol].cb_mutex;
Patrick McHardy77247bb2005-08-14 19:27:13 -0700449 netlink_unlock_table();
Harald Welte4fdb3bb2005-08-09 19:40:55 -0700450
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800451 err = __netlink_create(net, sock, cb_mutex, protocol);
452 if (err < 0)
Patrick McHardyab33a172005-08-14 19:31:36 -0700453 goto out_module;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700455 nlk = nlk_sk(sock->sk);
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700456 nlk->module = module;
Patrick McHardyab33a172005-08-14 19:31:36 -0700457out:
458 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459
Patrick McHardyab33a172005-08-14 19:31:36 -0700460out_module:
461 module_put(module);
462 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463}
464
465static int netlink_release(struct socket *sock)
466{
467 struct sock *sk = sock->sk;
468 struct netlink_sock *nlk;
469
470 if (!sk)
471 return 0;
472
473 netlink_remove(sk);
Denis Lunevac57b3a2007-04-18 17:05:58 -0700474 sock_orphan(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 nlk = nlk_sk(sk);
476
Herbert Xu3f660d62007-05-03 03:17:14 -0700477 /*
478 * OK. Socket is unlinked, any packets that arrive now
479 * will be purged.
480 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482 sock->sk = NULL;
483 wake_up_interruptible_all(&nlk->wait);
484
485 skb_queue_purge(&sk->sk_write_queue);
486
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700487 if (nlk->pid && !nlk->subscriptions) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 struct netlink_notify n = {
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900489 .net = sock_net(sk),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 .protocol = sk->sk_protocol,
491 .pid = nlk->pid,
492 };
Alan Sterne041c682006-03-27 01:16:30 -0800493 atomic_notifier_call_chain(&netlink_chain,
494 NETLINK_URELEASE, &n);
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +0900495 }
Harald Welte4fdb3bb2005-08-09 19:40:55 -0700496
Mariusz Kozlowski5e7c0012007-01-02 15:24:30 -0800497 module_put(nlk->module);
Harald Welte4fdb3bb2005-08-09 19:40:55 -0700498
Patrick McHardy4277a082006-03-20 18:52:01 -0800499 netlink_table_grab();
Denis V. Lunevaed81562007-10-10 21:14:32 -0700500 if (netlink_is_kernel(sk)) {
Denis V. Lunev869e58f2008-01-18 23:53:31 -0800501 BUG_ON(nl_table[sk->sk_protocol].registered == 0);
502 if (--nl_table[sk->sk_protocol].registered == 0) {
503 kfree(nl_table[sk->sk_protocol].listeners);
504 nl_table[sk->sk_protocol].module = NULL;
505 nl_table[sk->sk_protocol].registered = 0;
506 }
Patrick McHardy4277a082006-03-20 18:52:01 -0800507 } else if (nlk->subscriptions)
508 netlink_update_listeners(sk);
509 netlink_table_ungrab();
Patrick McHardy77247bb2005-08-14 19:27:13 -0700510
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700511 kfree(nlk->groups);
512 nlk->groups = NULL;
513
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 sock_put(sk);
515 return 0;
516}
517
518static int netlink_autobind(struct socket *sock)
519{
520 struct sock *sk = sock->sk;
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900521 struct net *net = sock_net(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
523 struct hlist_head *head;
524 struct sock *osk;
525 struct hlist_node *node;
Herbert Xuc27bd492005-11-22 14:41:50 -0800526 s32 pid = current->tgid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527 int err;
528 static s32 rover = -4097;
529
530retry:
531 cond_resched();
532 netlink_table_grab();
533 head = nl_pid_hashfn(hash, pid);
534 sk_for_each(osk, node, head) {
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900535 if (sock_net(osk) != net)
Eric W. Biedermanb4b51022007-09-12 13:05:38 +0200536 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 if (nlk_sk(osk)->pid == pid) {
538 /* Bind collision, search negative pid values. */
539 pid = rover--;
540 if (rover > -4097)
541 rover = -4097;
542 netlink_table_ungrab();
543 goto retry;
544 }
545 }
546 netlink_table_ungrab();
547
Eric W. Biedermanb4b51022007-09-12 13:05:38 +0200548 err = netlink_insert(sk, net, pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 if (err == -EADDRINUSE)
550 goto retry;
David S. Millerd470e3b2005-06-26 15:31:51 -0700551
552 /* If 2 threads race to autobind, that is fine. */
553 if (err == -EBUSY)
554 err = 0;
555
556 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557}
558
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +0900559static inline int netlink_capable(struct socket *sock, unsigned int flag)
560{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) ||
562 capable(CAP_NET_ADMIN);
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +0900563}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700565static void
566netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions)
567{
568 struct netlink_sock *nlk = nlk_sk(sk);
569
570 if (nlk->subscriptions && !subscriptions)
571 __sk_del_bind_node(sk);
572 else if (!nlk->subscriptions && subscriptions)
573 sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
574 nlk->subscriptions = subscriptions;
575}
576
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700577static int netlink_realloc_groups(struct sock *sk)
Patrick McHardy513c2502005-09-06 15:43:59 -0700578{
579 struct netlink_sock *nlk = nlk_sk(sk);
580 unsigned int groups;
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700581 unsigned long *new_groups;
Patrick McHardy513c2502005-09-06 15:43:59 -0700582 int err = 0;
583
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700584 netlink_table_grab();
585
Patrick McHardy513c2502005-09-06 15:43:59 -0700586 groups = nl_table[sk->sk_protocol].groups;
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700587 if (!nl_table[sk->sk_protocol].registered) {
Patrick McHardy513c2502005-09-06 15:43:59 -0700588 err = -ENOENT;
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700589 goto out_unlock;
590 }
Patrick McHardy513c2502005-09-06 15:43:59 -0700591
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700592 if (nlk->ngroups >= groups)
593 goto out_unlock;
Patrick McHardy513c2502005-09-06 15:43:59 -0700594
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700595 new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC);
596 if (new_groups == NULL) {
597 err = -ENOMEM;
598 goto out_unlock;
599 }
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800600 memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0,
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700601 NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups));
602
603 nlk->groups = new_groups;
Patrick McHardy513c2502005-09-06 15:43:59 -0700604 nlk->ngroups = groups;
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700605 out_unlock:
606 netlink_table_ungrab();
607 return err;
Patrick McHardy513c2502005-09-06 15:43:59 -0700608}
609
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800610static int netlink_bind(struct socket *sock, struct sockaddr *addr,
611 int addr_len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612{
613 struct sock *sk = sock->sk;
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900614 struct net *net = sock_net(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 struct netlink_sock *nlk = nlk_sk(sk);
616 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
617 int err;
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +0900618
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 if (nladdr->nl_family != AF_NETLINK)
620 return -EINVAL;
621
622 /* Only superuser is allowed to listen multicasts */
Patrick McHardy513c2502005-09-06 15:43:59 -0700623 if (nladdr->nl_groups) {
624 if (!netlink_capable(sock, NL_NONROOT_RECV))
625 return -EPERM;
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700626 err = netlink_realloc_groups(sk);
627 if (err)
628 return err;
Patrick McHardy513c2502005-09-06 15:43:59 -0700629 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630
631 if (nlk->pid) {
632 if (nladdr->nl_pid != nlk->pid)
633 return -EINVAL;
634 } else {
635 err = nladdr->nl_pid ?
Eric W. Biedermanb4b51022007-09-12 13:05:38 +0200636 netlink_insert(sk, net, nladdr->nl_pid) :
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 netlink_autobind(sock);
638 if (err)
639 return err;
640 }
641
Patrick McHardy513c2502005-09-06 15:43:59 -0700642 if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 return 0;
644
645 netlink_table_grab();
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700646 netlink_update_subscriptions(sk, nlk->subscriptions +
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +0900647 hweight32(nladdr->nl_groups) -
648 hweight32(nlk->groups[0]));
649 nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups;
Patrick McHardy4277a082006-03-20 18:52:01 -0800650 netlink_update_listeners(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 netlink_table_ungrab();
652
653 return 0;
654}
655
656static int netlink_connect(struct socket *sock, struct sockaddr *addr,
657 int alen, int flags)
658{
659 int err = 0;
660 struct sock *sk = sock->sk;
661 struct netlink_sock *nlk = nlk_sk(sk);
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800662 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663
664 if (addr->sa_family == AF_UNSPEC) {
665 sk->sk_state = NETLINK_UNCONNECTED;
666 nlk->dst_pid = 0;
Patrick McHardyd629b832005-08-14 19:27:50 -0700667 nlk->dst_group = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 return 0;
669 }
670 if (addr->sa_family != AF_NETLINK)
671 return -EINVAL;
672
673 /* Only superuser is allowed to send multicasts */
674 if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND))
675 return -EPERM;
676
677 if (!nlk->pid)
678 err = netlink_autobind(sock);
679
680 if (err == 0) {
681 sk->sk_state = NETLINK_CONNECTED;
682 nlk->dst_pid = nladdr->nl_pid;
Patrick McHardyd629b832005-08-14 19:27:50 -0700683 nlk->dst_group = ffs(nladdr->nl_groups);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 }
685
686 return err;
687}
688
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800689static int netlink_getname(struct socket *sock, struct sockaddr *addr,
690 int *addr_len, int peer)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691{
692 struct sock *sk = sock->sk;
693 struct netlink_sock *nlk = nlk_sk(sk);
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800694 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +0900695
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 nladdr->nl_family = AF_NETLINK;
697 nladdr->nl_pad = 0;
698 *addr_len = sizeof(*nladdr);
699
700 if (peer) {
701 nladdr->nl_pid = nlk->dst_pid;
Patrick McHardyd629b832005-08-14 19:27:50 -0700702 nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 } else {
704 nladdr->nl_pid = nlk->pid;
Patrick McHardy513c2502005-09-06 15:43:59 -0700705 nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 }
707 return 0;
708}
709
710static void netlink_overrun(struct sock *sk)
711{
712 if (!test_and_set_bit(0, &nlk_sk(sk)->state)) {
713 sk->sk_err = ENOBUFS;
714 sk->sk_error_report(sk);
715 }
716}
717
718static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid)
719{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720 struct sock *sock;
721 struct netlink_sock *nlk;
722
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900723 sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724 if (!sock)
725 return ERR_PTR(-ECONNREFUSED);
726
727 /* Don't bother queuing skb if kernel socket has no input function */
728 nlk = nlk_sk(sock);
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700729 if (sock->sk_state == NETLINK_CONNECTED &&
730 nlk->dst_pid != nlk_sk(ssk)->pid) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 sock_put(sock);
732 return ERR_PTR(-ECONNREFUSED);
733 }
734 return sock;
735}
736
737struct sock *netlink_getsockbyfilp(struct file *filp)
738{
Josef Sipek6db5fc52006-12-08 02:37:25 -0800739 struct inode *inode = filp->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 struct sock *sock;
741
742 if (!S_ISSOCK(inode->i_mode))
743 return ERR_PTR(-ENOTSOCK);
744
745 sock = SOCKET_I(inode)->sk;
746 if (sock->sk_family != AF_NETLINK)
747 return ERR_PTR(-EINVAL);
748
749 sock_hold(sock);
750 return sock;
751}
752
753/*
754 * Attach a skb to a netlink socket.
755 * The caller must hold a reference to the destination socket. On error, the
756 * reference is dropped. The skb is not send to the destination, just all
757 * all error checks are performed and memory in the queue is reserved.
758 * Return values:
759 * < 0: error. skb freed, reference to sock dropped.
760 * 0: continue
761 * 1: repeat lookup - reference dropped while waiting for socket memory.
762 */
Alexey Kuznetsova70ea992006-02-09 16:40:11 -0800763int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock,
Patrick McHardyc3d8d1e2007-11-07 02:42:09 -0800764 long *timeo, struct sock *ssk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765{
766 struct netlink_sock *nlk;
767
768 nlk = nlk_sk(sk);
769
770 if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
771 test_bit(0, &nlk->state)) {
772 DECLARE_WAITQUEUE(wait, current);
Patrick McHardyc3d8d1e2007-11-07 02:42:09 -0800773 if (!*timeo) {
Denis V. Lunevaed81562007-10-10 21:14:32 -0700774 if (!ssk || netlink_is_kernel(ssk))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775 netlink_overrun(sk);
776 sock_put(sk);
777 kfree_skb(skb);
778 return -EAGAIN;
779 }
780
781 __set_current_state(TASK_INTERRUPTIBLE);
782 add_wait_queue(&nlk->wait, &wait);
783
784 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
785 test_bit(0, &nlk->state)) &&
786 !sock_flag(sk, SOCK_DEAD))
Patrick McHardyc3d8d1e2007-11-07 02:42:09 -0800787 *timeo = schedule_timeout(*timeo);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788
789 __set_current_state(TASK_RUNNING);
790 remove_wait_queue(&nlk->wait, &wait);
791 sock_put(sk);
792
793 if (signal_pending(current)) {
794 kfree_skb(skb);
Patrick McHardyc3d8d1e2007-11-07 02:42:09 -0800795 return sock_intr_errno(*timeo);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 }
797 return 1;
798 }
799 skb_set_owner_r(skb, sk);
800 return 0;
801}
802
Denis V. Lunev7ee015e2007-10-10 21:14:03 -0700803int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 int len = skb->len;
806
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 skb_queue_tail(&sk->sk_receive_queue, skb);
808 sk->sk_data_ready(sk, len);
809 sock_put(sk);
810 return len;
811}
812
813void netlink_detachskb(struct sock *sk, struct sk_buff *skb)
814{
815 kfree_skb(skb);
816 sock_put(sk);
817}
818
Victor Fusco37da6472005-07-18 13:35:43 -0700819static inline struct sk_buff *netlink_trim(struct sk_buff *skb,
Al Virodd0fc662005-10-07 07:46:04 +0100820 gfp_t allocation)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700821{
822 int delta;
823
824 skb_orphan(skb);
825
Arnaldo Carvalho de Melo4305b542007-04-19 20:43:29 -0700826 delta = skb->end - skb->tail;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827 if (delta * 2 < skb->truesize)
828 return skb;
829
830 if (skb_shared(skb)) {
831 struct sk_buff *nskb = skb_clone(skb, allocation);
832 if (!nskb)
833 return skb;
834 kfree_skb(skb);
835 skb = nskb;
836 }
837
838 if (!pskb_expand_head(skb, 0, -delta, allocation))
839 skb->truesize -= delta;
840
841 return skb;
842}
843
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700844static inline void netlink_rcv_wake(struct sock *sk)
845{
846 struct netlink_sock *nlk = nlk_sk(sk);
847
848 if (skb_queue_empty(&sk->sk_receive_queue))
849 clear_bit(0, &nlk->state);
850 if (!test_bit(0, &nlk->state))
851 wake_up_interruptible(&nlk->wait);
852}
853
854static inline int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb)
855{
856 int ret;
857 struct netlink_sock *nlk = nlk_sk(sk);
858
859 ret = -ECONNREFUSED;
860 if (nlk->netlink_rcv != NULL) {
861 ret = skb->len;
862 skb_set_owner_r(skb, sk);
863 nlk->netlink_rcv(skb);
864 }
865 kfree_skb(skb);
866 sock_put(sk);
867 return ret;
868}
869
870int netlink_unicast(struct sock *ssk, struct sk_buff *skb,
871 u32 pid, int nonblock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872{
873 struct sock *sk;
874 int err;
875 long timeo;
876
877 skb = netlink_trim(skb, gfp_any());
878
879 timeo = sock_sndtimeo(ssk, nonblock);
880retry:
881 sk = netlink_getsockbypid(ssk, pid);
882 if (IS_ERR(sk)) {
883 kfree_skb(skb);
884 return PTR_ERR(sk);
885 }
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700886 if (netlink_is_kernel(sk))
887 return netlink_unicast_kernel(sk, skb);
888
Stephen Hemmingerb1153f22008-03-21 15:46:12 -0700889 if (sk_filter(sk, skb)) {
890 int err = skb->len;
891 kfree_skb(skb);
892 sock_put(sk);
893 return err;
894 }
895
Patrick McHardyc3d8d1e2007-11-07 02:42:09 -0800896 err = netlink_attachskb(sk, skb, nonblock, &timeo, ssk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897 if (err == 1)
898 goto retry;
899 if (err)
900 return err;
901
Denis V. Lunev7ee015e2007-10-10 21:14:03 -0700902 return netlink_sendskb(sk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903}
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800904EXPORT_SYMBOL(netlink_unicast);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905
Patrick McHardy4277a082006-03-20 18:52:01 -0800906int netlink_has_listeners(struct sock *sk, unsigned int group)
907{
908 int res = 0;
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700909 unsigned long *listeners;
Patrick McHardy4277a082006-03-20 18:52:01 -0800910
Denis V. Lunevaed81562007-10-10 21:14:32 -0700911 BUG_ON(!netlink_is_kernel(sk));
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700912
913 rcu_read_lock();
914 listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners);
915
Patrick McHardy4277a082006-03-20 18:52:01 -0800916 if (group - 1 < nl_table[sk->sk_protocol].groups)
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700917 res = test_bit(group - 1, listeners);
918
919 rcu_read_unlock();
920
Patrick McHardy4277a082006-03-20 18:52:01 -0800921 return res;
922}
923EXPORT_SYMBOL_GPL(netlink_has_listeners);
924
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800925static inline int netlink_broadcast_deliver(struct sock *sk,
926 struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927{
928 struct netlink_sock *nlk = nlk_sk(sk);
929
930 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
931 !test_bit(0, &nlk->state)) {
932 skb_set_owner_r(skb, sk);
933 skb_queue_tail(&sk->sk_receive_queue, skb);
934 sk->sk_data_ready(sk, skb->len);
935 return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf;
936 }
937 return -1;
938}
939
940struct netlink_broadcast_data {
941 struct sock *exclude_sk;
Eric W. Biedermanb4b51022007-09-12 13:05:38 +0200942 struct net *net;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943 u32 pid;
944 u32 group;
945 int failure;
946 int congested;
947 int delivered;
Al Viro7d877f32005-10-21 03:20:43 -0400948 gfp_t allocation;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949 struct sk_buff *skb, *skb2;
950};
951
952static inline int do_one_broadcast(struct sock *sk,
953 struct netlink_broadcast_data *p)
954{
955 struct netlink_sock *nlk = nlk_sk(sk);
956 int val;
957
958 if (p->exclude_sk == sk)
959 goto out;
960
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700961 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
962 !test_bit(p->group - 1, nlk->groups))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963 goto out;
964
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900965 if (sock_net(sk) != p->net)
Eric W. Biedermanb4b51022007-09-12 13:05:38 +0200966 goto out;
967
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968 if (p->failure) {
969 netlink_overrun(sk);
970 goto out;
971 }
972
973 sock_hold(sk);
974 if (p->skb2 == NULL) {
Tommy S. Christensen68acc022005-05-19 13:06:35 -0700975 if (skb_shared(p->skb)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 p->skb2 = skb_clone(p->skb, p->allocation);
977 } else {
Tommy S. Christensen68acc022005-05-19 13:06:35 -0700978 p->skb2 = skb_get(p->skb);
979 /*
980 * skb ownership may have been set when
981 * delivered to a previous socket.
982 */
983 skb_orphan(p->skb2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700984 }
985 }
986 if (p->skb2 == NULL) {
987 netlink_overrun(sk);
988 /* Clone failed. Notify ALL listeners. */
989 p->failure = 1;
Stephen Hemmingerb1153f22008-03-21 15:46:12 -0700990 } else if (sk_filter(sk, p->skb2)) {
991 kfree_skb(p->skb2);
992 p->skb2 = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993 } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) {
994 netlink_overrun(sk);
995 } else {
996 p->congested |= val;
997 p->delivered = 1;
998 p->skb2 = NULL;
999 }
1000 sock_put(sk);
1001
1002out:
1003 return 0;
1004}
1005
1006int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
Al Virodd0fc662005-10-07 07:46:04 +01001007 u32 group, gfp_t allocation)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008{
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +09001009 struct net *net = sock_net(ssk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010 struct netlink_broadcast_data info;
1011 struct hlist_node *node;
1012 struct sock *sk;
1013
1014 skb = netlink_trim(skb, allocation);
1015
1016 info.exclude_sk = ssk;
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001017 info.net = net;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018 info.pid = pid;
1019 info.group = group;
1020 info.failure = 0;
1021 info.congested = 0;
1022 info.delivered = 0;
1023 info.allocation = allocation;
1024 info.skb = skb;
1025 info.skb2 = NULL;
1026
1027 /* While we sleep in clone, do not allow to change socket list */
1028
1029 netlink_lock_table();
1030
1031 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
1032 do_one_broadcast(sk, &info);
1033
Tommy S. Christensenaa1c6a62005-05-19 13:07:32 -07001034 kfree_skb(skb);
1035
Linus Torvalds1da177e2005-04-16 15:20:36 -07001036 netlink_unlock_table();
1037
1038 if (info.skb2)
1039 kfree_skb(info.skb2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040
1041 if (info.delivered) {
1042 if (info.congested && (allocation & __GFP_WAIT))
1043 yield();
1044 return 0;
1045 }
1046 if (info.failure)
1047 return -ENOBUFS;
1048 return -ESRCH;
1049}
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001050EXPORT_SYMBOL(netlink_broadcast);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001051
1052struct netlink_set_err_data {
1053 struct sock *exclude_sk;
1054 u32 pid;
1055 u32 group;
1056 int code;
1057};
1058
1059static inline int do_one_set_err(struct sock *sk,
1060 struct netlink_set_err_data *p)
1061{
1062 struct netlink_sock *nlk = nlk_sk(sk);
1063
1064 if (sk == p->exclude_sk)
1065 goto out;
1066
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +09001067 if (sock_net(sk) != sock_net(p->exclude_sk))
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001068 goto out;
1069
Patrick McHardyf7fa9b12005-08-15 12:29:13 -07001070 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
1071 !test_bit(p->group - 1, nlk->groups))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001072 goto out;
1073
1074 sk->sk_err = p->code;
1075 sk->sk_error_report(sk);
1076out:
1077 return 0;
1078}
1079
1080void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code)
1081{
1082 struct netlink_set_err_data info;
1083 struct hlist_node *node;
1084 struct sock *sk;
1085
1086 info.exclude_sk = ssk;
1087 info.pid = pid;
1088 info.group = group;
1089 info.code = code;
1090
1091 read_lock(&nl_table_lock);
1092
1093 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
1094 do_one_set_err(sk, &info);
1095
1096 read_unlock(&nl_table_lock);
1097}
1098
Johannes Berg84659eb2007-07-18 15:47:05 -07001099/* must be called with netlink table grabbed */
1100static void netlink_update_socket_mc(struct netlink_sock *nlk,
1101 unsigned int group,
1102 int is_new)
1103{
1104 int old, new = !!is_new, subscriptions;
1105
1106 old = test_bit(group - 1, nlk->groups);
1107 subscriptions = nlk->subscriptions - old + new;
1108 if (new)
1109 __set_bit(group - 1, nlk->groups);
1110 else
1111 __clear_bit(group - 1, nlk->groups);
1112 netlink_update_subscriptions(&nlk->sk, subscriptions);
1113 netlink_update_listeners(&nlk->sk);
1114}
1115
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001116static int netlink_setsockopt(struct socket *sock, int level, int optname,
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +09001117 char __user *optval, int optlen)
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001118{
1119 struct sock *sk = sock->sk;
1120 struct netlink_sock *nlk = nlk_sk(sk);
Johannes Bergeb496532007-07-18 02:07:51 -07001121 unsigned int val = 0;
1122 int err;
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001123
1124 if (level != SOL_NETLINK)
1125 return -ENOPROTOOPT;
1126
1127 if (optlen >= sizeof(int) &&
Johannes Bergeb496532007-07-18 02:07:51 -07001128 get_user(val, (unsigned int __user *)optval))
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001129 return -EFAULT;
1130
1131 switch (optname) {
1132 case NETLINK_PKTINFO:
1133 if (val)
1134 nlk->flags |= NETLINK_RECV_PKTINFO;
1135 else
1136 nlk->flags &= ~NETLINK_RECV_PKTINFO;
1137 err = 0;
1138 break;
1139 case NETLINK_ADD_MEMBERSHIP:
1140 case NETLINK_DROP_MEMBERSHIP: {
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001141 if (!netlink_capable(sock, NL_NONROOT_RECV))
1142 return -EPERM;
Johannes Bergb4ff4f02007-07-18 15:46:06 -07001143 err = netlink_realloc_groups(sk);
1144 if (err)
1145 return err;
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001146 if (!val || val - 1 >= nlk->ngroups)
1147 return -EINVAL;
1148 netlink_table_grab();
Johannes Berg84659eb2007-07-18 15:47:05 -07001149 netlink_update_socket_mc(nlk, val,
1150 optname == NETLINK_ADD_MEMBERSHIP);
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001151 netlink_table_ungrab();
1152 err = 0;
1153 break;
1154 }
1155 default:
1156 err = -ENOPROTOOPT;
1157 }
1158 return err;
1159}
1160
1161static int netlink_getsockopt(struct socket *sock, int level, int optname,
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +09001162 char __user *optval, int __user *optlen)
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001163{
1164 struct sock *sk = sock->sk;
1165 struct netlink_sock *nlk = nlk_sk(sk);
1166 int len, val, err;
1167
1168 if (level != SOL_NETLINK)
1169 return -ENOPROTOOPT;
1170
1171 if (get_user(len, optlen))
1172 return -EFAULT;
1173 if (len < 0)
1174 return -EINVAL;
1175
1176 switch (optname) {
1177 case NETLINK_PKTINFO:
1178 if (len < sizeof(int))
1179 return -EINVAL;
1180 len = sizeof(int);
1181 val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0;
Heiko Carstensa27b58f2006-10-30 15:06:12 -08001182 if (put_user(len, optlen) ||
1183 put_user(val, optval))
1184 return -EFAULT;
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001185 err = 0;
1186 break;
1187 default:
1188 err = -ENOPROTOOPT;
1189 }
1190 return err;
1191}
1192
1193static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
1194{
1195 struct nl_pktinfo info;
1196
1197 info.group = NETLINK_CB(skb).dst_group;
1198 put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info);
1199}
1200
Linus Torvalds1da177e2005-04-16 15:20:36 -07001201static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
1202 struct msghdr *msg, size_t len)
1203{
1204 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1205 struct sock *sk = sock->sk;
1206 struct netlink_sock *nlk = nlk_sk(sk);
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001207 struct sockaddr_nl *addr = msg->msg_name;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001208 u32 dst_pid;
Patrick McHardyd629b832005-08-14 19:27:50 -07001209 u32 dst_group;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001210 struct sk_buff *skb;
1211 int err;
1212 struct scm_cookie scm;
1213
1214 if (msg->msg_flags&MSG_OOB)
1215 return -EOPNOTSUPP;
1216
1217 if (NULL == siocb->scm)
1218 siocb->scm = &scm;
1219 err = scm_send(sock, msg, siocb->scm);
1220 if (err < 0)
1221 return err;
1222
1223 if (msg->msg_namelen) {
1224 if (addr->nl_family != AF_NETLINK)
1225 return -EINVAL;
1226 dst_pid = addr->nl_pid;
Patrick McHardyd629b832005-08-14 19:27:50 -07001227 dst_group = ffs(addr->nl_groups);
1228 if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001229 return -EPERM;
1230 } else {
1231 dst_pid = nlk->dst_pid;
Patrick McHardyd629b832005-08-14 19:27:50 -07001232 dst_group = nlk->dst_group;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001233 }
1234
1235 if (!nlk->pid) {
1236 err = netlink_autobind(sock);
1237 if (err)
1238 goto out;
1239 }
1240
1241 err = -EMSGSIZE;
1242 if (len > sk->sk_sndbuf - 32)
1243 goto out;
1244 err = -ENOBUFS;
Thomas Graf339bf982006-11-10 14:10:15 -08001245 skb = alloc_skb(len, GFP_KERNEL);
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001246 if (skb == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001247 goto out;
1248
1249 NETLINK_CB(skb).pid = nlk->pid;
Patrick McHardyd629b832005-08-14 19:27:50 -07001250 NETLINK_CB(skb).dst_group = dst_group;
Al Viro0c11b942008-01-10 04:20:52 -05001251 NETLINK_CB(skb).loginuid = audit_get_loginuid(current);
Steve Grubbe7c34972006-04-03 09:08:13 -04001252 selinux_get_task_sid(current, &(NETLINK_CB(skb).sid));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001253 memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1254
1255 /* What can I do? Netlink is asynchronous, so that
1256 we will have to save current capabilities to
1257 check them, when this message will be delivered
1258 to corresponding kernel module. --ANK (980802)
1259 */
1260
1261 err = -EFAULT;
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001262 if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263 kfree_skb(skb);
1264 goto out;
1265 }
1266
1267 err = security_netlink_send(sk, skb);
1268 if (err) {
1269 kfree_skb(skb);
1270 goto out;
1271 }
1272
Patrick McHardyd629b832005-08-14 19:27:50 -07001273 if (dst_group) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001274 atomic_inc(&skb->users);
Patrick McHardyd629b832005-08-14 19:27:50 -07001275 netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276 }
1277 err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT);
1278
1279out:
1280 return err;
1281}
1282
1283static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
1284 struct msghdr *msg, size_t len,
1285 int flags)
1286{
1287 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1288 struct scm_cookie scm;
1289 struct sock *sk = sock->sk;
1290 struct netlink_sock *nlk = nlk_sk(sk);
1291 int noblock = flags&MSG_DONTWAIT;
1292 size_t copied;
1293 struct sk_buff *skb;
1294 int err;
1295
1296 if (flags&MSG_OOB)
1297 return -EOPNOTSUPP;
1298
1299 copied = 0;
1300
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001301 skb = skb_recv_datagram(sk, flags, noblock, &err);
1302 if (skb == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001303 goto out;
1304
1305 msg->msg_namelen = 0;
1306
1307 copied = skb->len;
1308 if (len < copied) {
1309 msg->msg_flags |= MSG_TRUNC;
1310 copied = len;
1311 }
1312
Arnaldo Carvalho de Melobadff6d2007-03-13 13:06:52 -03001313 skb_reset_transport_header(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001314 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
1315
1316 if (msg->msg_name) {
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001317 struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001318 addr->nl_family = AF_NETLINK;
1319 addr->nl_pad = 0;
1320 addr->nl_pid = NETLINK_CB(skb).pid;
Patrick McHardyd629b832005-08-14 19:27:50 -07001321 addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001322 msg->msg_namelen = sizeof(*addr);
1323 }
1324
Patrick McHardycc9a06c2006-03-12 20:34:27 -08001325 if (nlk->flags & NETLINK_RECV_PKTINFO)
1326 netlink_cmsg_recv_pktinfo(msg, skb);
1327
Linus Torvalds1da177e2005-04-16 15:20:36 -07001328 if (NULL == siocb->scm) {
1329 memset(&scm, 0, sizeof(scm));
1330 siocb->scm = &scm;
1331 }
1332 siocb->scm->creds = *NETLINK_CREDS(skb);
Patrick McHardy188ccb52007-05-03 03:27:01 -07001333 if (flags & MSG_TRUNC)
1334 copied = skb->len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001335 skb_free_datagram(sk, skb);
1336
1337 if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2)
1338 netlink_dump(sk);
1339
1340 scm_recv(sock, msg, siocb->scm, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001341out:
1342 netlink_rcv_wake(sk);
1343 return err ? : copied;
1344}
1345
1346static void netlink_data_ready(struct sock *sk, int len)
1347{
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -07001348 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001349}
1350
1351/*
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +09001352 * We export these functions to other modules. They provide a
Linus Torvalds1da177e2005-04-16 15:20:36 -07001353 * complete set of kernel non-blocking support for message
1354 * queueing.
1355 */
1356
1357struct sock *
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001358netlink_kernel_create(struct net *net, int unit, unsigned int groups,
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -07001359 void (*input)(struct sk_buff *skb),
Patrick McHardyaf65bdf2007-04-20 14:14:21 -07001360 struct mutex *cb_mutex, struct module *module)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001361{
1362 struct socket *sock;
1363 struct sock *sk;
Patrick McHardy77247bb2005-08-14 19:27:13 -07001364 struct netlink_sock *nlk;
Patrick McHardy4277a082006-03-20 18:52:01 -08001365 unsigned long *listeners = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001366
Akinobu Mitafab2caf2006-08-29 02:15:24 -07001367 BUG_ON(!nl_table);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001368
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001369 if (unit < 0 || unit >= MAX_LINKS)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001370 return NULL;
1371
1372 if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
1373 return NULL;
1374
Pavel Emelyanov23fe1862008-01-30 19:31:06 -08001375 /*
1376 * We have to just have a reference on the net from sk, but don't
1377 * get_net it. Besides, we cannot get and then put the net here.
1378 * So we create one inside init_net and the move it to net.
1379 */
1380
1381 if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0)
1382 goto out_sock_release_nosk;
1383
1384 sk = sock->sk;
Denis V. Lunevedf02082008-02-29 11:18:32 -08001385 sk_change_net(sk, net);
Harald Welte4fdb3bb2005-08-09 19:40:55 -07001386
Patrick McHardy4277a082006-03-20 18:52:01 -08001387 if (groups < 32)
1388 groups = 32;
1389
1390 listeners = kzalloc(NLGRPSZ(groups), GFP_KERNEL);
1391 if (!listeners)
1392 goto out_sock_release;
1393
Linus Torvalds1da177e2005-04-16 15:20:36 -07001394 sk->sk_data_ready = netlink_data_ready;
1395 if (input)
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -07001396 nlk_sk(sk)->netlink_rcv = input;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001397
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001398 if (netlink_insert(sk, net, 0))
Patrick McHardy77247bb2005-08-14 19:27:13 -07001399 goto out_sock_release;
1400
1401 nlk = nlk_sk(sk);
1402 nlk->flags |= NETLINK_KERNEL_SOCKET;
1403
1404 netlink_table_grab();
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001405 if (!nl_table[unit].registered) {
1406 nl_table[unit].groups = groups;
1407 nl_table[unit].listeners = listeners;
1408 nl_table[unit].cb_mutex = cb_mutex;
1409 nl_table[unit].module = module;
1410 nl_table[unit].registered = 1;
Jesper Juhlf937f1f462007-10-15 01:39:12 -07001411 } else {
1412 kfree(listeners);
Denis V. Lunev869e58f2008-01-18 23:53:31 -08001413 nl_table[unit].registered++;
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001414 }
Patrick McHardy77247bb2005-08-14 19:27:13 -07001415 netlink_table_ungrab();
Harald Welte4fdb3bb2005-08-09 19:40:55 -07001416 return sk;
1417
Harald Welte4fdb3bb2005-08-09 19:40:55 -07001418out_sock_release:
Patrick McHardy4277a082006-03-20 18:52:01 -08001419 kfree(listeners);
Denis V. Lunev9dfbec12008-02-29 11:17:56 -08001420 netlink_kernel_release(sk);
Pavel Emelyanov23fe1862008-01-30 19:31:06 -08001421 return NULL;
1422
1423out_sock_release_nosk:
Harald Welte4fdb3bb2005-08-09 19:40:55 -07001424 sock_release(sock);
Patrick McHardy77247bb2005-08-14 19:27:13 -07001425 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001426}
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001427EXPORT_SYMBOL(netlink_kernel_create);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001428
Denis V. Lunevb7c6ba62008-01-28 14:41:19 -08001429
1430void
1431netlink_kernel_release(struct sock *sk)
1432{
Denis V. Lunevedf02082008-02-29 11:18:32 -08001433 sk_release_kernel(sk);
Denis V. Lunevb7c6ba62008-01-28 14:41:19 -08001434}
1435EXPORT_SYMBOL(netlink_kernel_release);
1436
1437
Johannes Bergb4ff4f02007-07-18 15:46:06 -07001438/**
1439 * netlink_change_ngroups - change number of multicast groups
1440 *
1441 * This changes the number of multicast groups that are available
1442 * on a certain netlink family. Note that it is not possible to
Johannes Berg84659eb2007-07-18 15:47:05 -07001443 * change the number of groups to below 32. Also note that it does
1444 * not implicitly call netlink_clear_multicast_users() when the
1445 * number of groups is reduced.
Johannes Bergb4ff4f02007-07-18 15:46:06 -07001446 *
1447 * @sk: The kernel netlink socket, as returned by netlink_kernel_create().
1448 * @groups: The new number of groups.
1449 */
1450int netlink_change_ngroups(struct sock *sk, unsigned int groups)
1451{
1452 unsigned long *listeners, *old = NULL;
1453 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
1454 int err = 0;
1455
1456 if (groups < 32)
1457 groups = 32;
1458
1459 netlink_table_grab();
1460 if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) {
1461 listeners = kzalloc(NLGRPSZ(groups), GFP_ATOMIC);
1462 if (!listeners) {
1463 err = -ENOMEM;
1464 goto out_ungrab;
1465 }
1466 old = tbl->listeners;
1467 memcpy(listeners, old, NLGRPSZ(tbl->groups));
1468 rcu_assign_pointer(tbl->listeners, listeners);
1469 }
1470 tbl->groups = groups;
1471
1472 out_ungrab:
1473 netlink_table_ungrab();
1474 synchronize_rcu();
1475 kfree(old);
1476 return err;
1477}
1478EXPORT_SYMBOL(netlink_change_ngroups);
1479
Johannes Berg84659eb2007-07-18 15:47:05 -07001480/**
1481 * netlink_clear_multicast_users - kick off multicast listeners
1482 *
1483 * This function removes all listeners from the given group.
1484 * @ksk: The kernel netlink socket, as returned by
1485 * netlink_kernel_create().
1486 * @group: The multicast group to clear.
1487 */
1488void netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
1489{
1490 struct sock *sk;
1491 struct hlist_node *node;
1492 struct netlink_table *tbl = &nl_table[ksk->sk_protocol];
1493
1494 netlink_table_grab();
1495
1496 sk_for_each_bound(sk, node, &tbl->mc_list)
1497 netlink_update_socket_mc(nlk_sk(sk), group, 0);
1498
1499 netlink_table_ungrab();
1500}
1501EXPORT_SYMBOL(netlink_clear_multicast_users);
1502
Linus Torvalds1da177e2005-04-16 15:20:36 -07001503void netlink_set_nonroot(int protocol, unsigned int flags)
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +09001504{
1505 if ((unsigned int)protocol < MAX_LINKS)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001506 nl_table[protocol].nl_nonroot = flags;
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +09001507}
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001508EXPORT_SYMBOL(netlink_set_nonroot);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001509
1510static void netlink_destroy_callback(struct netlink_callback *cb)
1511{
1512 if (cb->skb)
1513 kfree_skb(cb->skb);
1514 kfree(cb);
1515}
1516
1517/*
1518 * It looks a bit ugly.
1519 * It would be better to create kernel thread.
1520 */
1521
1522static int netlink_dump(struct sock *sk)
1523{
1524 struct netlink_sock *nlk = nlk_sk(sk);
1525 struct netlink_callback *cb;
1526 struct sk_buff *skb;
1527 struct nlmsghdr *nlh;
Thomas Grafbf8b79e2006-08-04 23:03:29 -07001528 int len, err = -ENOBUFS;
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +09001529
Linus Torvalds1da177e2005-04-16 15:20:36 -07001530 skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL);
1531 if (!skb)
Thomas Grafbf8b79e2006-08-04 23:03:29 -07001532 goto errout;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001533
Patrick McHardyaf65bdf2007-04-20 14:14:21 -07001534 mutex_lock(nlk->cb_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001535
1536 cb = nlk->cb;
1537 if (cb == NULL) {
Thomas Grafbf8b79e2006-08-04 23:03:29 -07001538 err = -EINVAL;
1539 goto errout_skb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001540 }
1541
1542 len = cb->dump(skb, cb);
1543
1544 if (len > 0) {
Patrick McHardyaf65bdf2007-04-20 14:14:21 -07001545 mutex_unlock(nlk->cb_mutex);
Stephen Hemmingerb1153f22008-03-21 15:46:12 -07001546
1547 if (sk_filter(sk, skb))
1548 kfree_skb(skb);
1549 else {
1550 skb_queue_tail(&sk->sk_receive_queue, skb);
1551 sk->sk_data_ready(sk, skb->len);
1552 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001553 return 0;
1554 }
1555
Thomas Grafbf8b79e2006-08-04 23:03:29 -07001556 nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI);
1557 if (!nlh)
1558 goto errout_skb;
1559
1560 memcpy(nlmsg_data(nlh), &len, sizeof(len));
1561
Stephen Hemmingerb1153f22008-03-21 15:46:12 -07001562 if (sk_filter(sk, skb))
1563 kfree_skb(skb);
1564 else {
1565 skb_queue_tail(&sk->sk_receive_queue, skb);
1566 sk->sk_data_ready(sk, skb->len);
1567 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001568
Thomas Grafa8f74b22005-11-10 02:25:52 +01001569 if (cb->done)
1570 cb->done(cb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001571 nlk->cb = NULL;
Patrick McHardyaf65bdf2007-04-20 14:14:21 -07001572 mutex_unlock(nlk->cb_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001573
1574 netlink_destroy_callback(cb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001575 return 0;
Thomas Graf17977542005-06-18 22:53:48 -07001576
Thomas Grafbf8b79e2006-08-04 23:03:29 -07001577errout_skb:
Patrick McHardyaf65bdf2007-04-20 14:14:21 -07001578 mutex_unlock(nlk->cb_mutex);
Thomas Grafbf8b79e2006-08-04 23:03:29 -07001579 kfree_skb(skb);
1580errout:
1581 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001582}
1583
1584int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
1585 struct nlmsghdr *nlh,
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001586 int (*dump)(struct sk_buff *skb,
1587 struct netlink_callback *),
1588 int (*done)(struct netlink_callback *))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001589{
1590 struct netlink_callback *cb;
1591 struct sock *sk;
1592 struct netlink_sock *nlk;
1593
Panagiotis Issaris0da974f2006-07-21 14:51:30 -07001594 cb = kzalloc(sizeof(*cb), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001595 if (cb == NULL)
1596 return -ENOBUFS;
1597
Linus Torvalds1da177e2005-04-16 15:20:36 -07001598 cb->dump = dump;
1599 cb->done = done;
1600 cb->nlh = nlh;
1601 atomic_inc(&skb->users);
1602 cb->skb = skb;
1603
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +09001604 sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001605 if (sk == NULL) {
1606 netlink_destroy_callback(cb);
1607 return -ECONNREFUSED;
1608 }
1609 nlk = nlk_sk(sk);
Herbert Xu3f660d62007-05-03 03:17:14 -07001610 /* A dump is in progress... */
Patrick McHardyaf65bdf2007-04-20 14:14:21 -07001611 mutex_lock(nlk->cb_mutex);
Herbert Xu3f660d62007-05-03 03:17:14 -07001612 if (nlk->cb) {
Patrick McHardyaf65bdf2007-04-20 14:14:21 -07001613 mutex_unlock(nlk->cb_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001614 netlink_destroy_callback(cb);
1615 sock_put(sk);
1616 return -EBUSY;
1617 }
1618 nlk->cb = cb;
Patrick McHardyaf65bdf2007-04-20 14:14:21 -07001619 mutex_unlock(nlk->cb_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001620
1621 netlink_dump(sk);
1622 sock_put(sk);
Denis V. Lunev5c582982007-10-23 20:29:25 -07001623
1624 /* We successfully started a dump, by returning -EINTR we
1625 * signal not to send ACK even if it was requested.
1626 */
1627 return -EINTR;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001628}
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001629EXPORT_SYMBOL(netlink_dump_start);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001630
1631void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
1632{
1633 struct sk_buff *skb;
1634 struct nlmsghdr *rep;
1635 struct nlmsgerr *errmsg;
Thomas Graf339bf982006-11-10 14:10:15 -08001636 size_t payload = sizeof(*errmsg);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001637
Thomas Graf339bf982006-11-10 14:10:15 -08001638 /* error messages get the original request appened */
1639 if (err)
1640 payload += nlmsg_len(nlh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001641
Thomas Graf339bf982006-11-10 14:10:15 -08001642 skb = nlmsg_new(payload, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001643 if (!skb) {
1644 struct sock *sk;
1645
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +09001646 sk = netlink_lookup(sock_net(in_skb->sk),
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001647 in_skb->sk->sk_protocol,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001648 NETLINK_CB(in_skb).pid);
1649 if (sk) {
1650 sk->sk_err = ENOBUFS;
1651 sk->sk_error_report(sk);
1652 sock_put(sk);
1653 }
1654 return;
1655 }
1656
1657 rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
Thomas Graf17977542005-06-18 22:53:48 -07001658 NLMSG_ERROR, sizeof(struct nlmsgerr), 0);
Thomas Grafbf8b79e2006-08-04 23:03:29 -07001659 errmsg = nlmsg_data(rep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001660 errmsg->error = err;
Thomas Grafbf8b79e2006-08-04 23:03:29 -07001661 memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001662 netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
1663}
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001664EXPORT_SYMBOL(netlink_ack);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001665
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -07001666int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
Thomas Graf1d00a4e2007-03-22 23:30:12 -07001667 struct nlmsghdr *))
Thomas Graf82ace472005-11-10 02:25:53 +01001668{
Thomas Graf82ace472005-11-10 02:25:53 +01001669 struct nlmsghdr *nlh;
1670 int err;
1671
1672 while (skb->len >= nlmsg_total_size(0)) {
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -07001673 int msglen;
1674
Arnaldo Carvalho de Melob529ccf2007-04-25 19:08:35 -07001675 nlh = nlmsg_hdr(skb);
Thomas Grafd35b6852007-03-22 23:28:46 -07001676 err = 0;
Thomas Graf82ace472005-11-10 02:25:53 +01001677
Martin Murrayad8e4b72006-01-10 13:02:29 -08001678 if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
Thomas Graf82ace472005-11-10 02:25:53 +01001679 return 0;
1680
Thomas Grafd35b6852007-03-22 23:28:46 -07001681 /* Only requests are handled by the kernel */
1682 if (!(nlh->nlmsg_flags & NLM_F_REQUEST))
Denis V. Lunev5c582982007-10-23 20:29:25 -07001683 goto ack;
Thomas Grafd35b6852007-03-22 23:28:46 -07001684
Thomas Graf45e7ae72007-03-22 23:29:10 -07001685 /* Skip control messages */
1686 if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
Denis V. Lunev5c582982007-10-23 20:29:25 -07001687 goto ack;
Thomas Graf45e7ae72007-03-22 23:29:10 -07001688
Thomas Graf1d00a4e2007-03-22 23:30:12 -07001689 err = cb(skb, nlh);
Denis V. Lunev5c582982007-10-23 20:29:25 -07001690 if (err == -EINTR)
1691 goto skip;
1692
1693ack:
Thomas Grafd35b6852007-03-22 23:28:46 -07001694 if (nlh->nlmsg_flags & NLM_F_ACK || err)
Thomas Graf82ace472005-11-10 02:25:53 +01001695 netlink_ack(skb, nlh, err);
Thomas Graf82ace472005-11-10 02:25:53 +01001696
Denis V. Lunev5c582982007-10-23 20:29:25 -07001697skip:
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001698 msglen = NLMSG_ALIGN(nlh->nlmsg_len);
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -07001699 if (msglen > skb->len)
1700 msglen = skb->len;
1701 skb_pull(skb, msglen);
Thomas Graf82ace472005-11-10 02:25:53 +01001702 }
1703
1704 return 0;
1705}
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001706EXPORT_SYMBOL(netlink_rcv_skb);
Thomas Graf82ace472005-11-10 02:25:53 +01001707
1708/**
Thomas Grafd387f6a2006-08-15 00:31:06 -07001709 * nlmsg_notify - send a notification netlink message
1710 * @sk: netlink socket to use
1711 * @skb: notification message
1712 * @pid: destination netlink pid for reports or 0
1713 * @group: destination multicast group or 0
1714 * @report: 1 to report back, 0 to disable
1715 * @flags: allocation flags
1716 */
1717int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid,
1718 unsigned int group, int report, gfp_t flags)
1719{
1720 int err = 0;
1721
1722 if (group) {
1723 int exclude_pid = 0;
1724
1725 if (report) {
1726 atomic_inc(&skb->users);
1727 exclude_pid = pid;
1728 }
1729
1730 /* errors reported via destination sk->sk_err */
1731 nlmsg_multicast(sk, skb, exclude_pid, group, flags);
1732 }
1733
1734 if (report)
1735 err = nlmsg_unicast(sk, skb, pid);
1736
1737 return err;
1738}
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001739EXPORT_SYMBOL(nlmsg_notify);
Thomas Grafd387f6a2006-08-15 00:31:06 -07001740
Linus Torvalds1da177e2005-04-16 15:20:36 -07001741#ifdef CONFIG_PROC_FS
1742struct nl_seq_iter {
Denis V. Luneve372c412007-11-19 22:31:54 -08001743 struct seq_net_private p;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001744 int link;
1745 int hash_idx;
1746};
1747
1748static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos)
1749{
1750 struct nl_seq_iter *iter = seq->private;
1751 int i, j;
1752 struct sock *s;
1753 struct hlist_node *node;
1754 loff_t off = 0;
1755
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001756 for (i = 0; i < MAX_LINKS; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001757 struct nl_pid_hash *hash = &nl_table[i].hash;
1758
1759 for (j = 0; j <= hash->mask; j++) {
1760 sk_for_each(s, node, &hash->table[j]) {
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +09001761 if (sock_net(s) != iter->p.net)
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001762 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001763 if (off == pos) {
1764 iter->link = i;
1765 iter->hash_idx = j;
1766 return s;
1767 }
1768 ++off;
1769 }
1770 }
1771 }
1772 return NULL;
1773}
1774
1775static void *netlink_seq_start(struct seq_file *seq, loff_t *pos)
Eric Dumazet9a429c42008-01-01 21:58:02 -08001776 __acquires(nl_table_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001777{
1778 read_lock(&nl_table_lock);
1779 return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN;
1780}
1781
1782static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1783{
1784 struct sock *s;
1785 struct nl_seq_iter *iter;
1786 int i, j;
1787
1788 ++*pos;
1789
1790 if (v == SEQ_START_TOKEN)
1791 return netlink_seq_socket_idx(seq, 0);
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +09001792
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001793 iter = seq->private;
1794 s = v;
1795 do {
1796 s = sk_next(s);
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +09001797 } while (s && (sock_net(s) != iter->p.net));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001798 if (s)
1799 return s;
1800
Linus Torvalds1da177e2005-04-16 15:20:36 -07001801 i = iter->link;
1802 j = iter->hash_idx + 1;
1803
1804 do {
1805 struct nl_pid_hash *hash = &nl_table[i].hash;
1806
1807 for (; j <= hash->mask; j++) {
1808 s = sk_head(&hash->table[j]);
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +09001809 while (s && sock_net(s) != iter->p.net)
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001810 s = sk_next(s);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001811 if (s) {
1812 iter->link = i;
1813 iter->hash_idx = j;
1814 return s;
1815 }
1816 }
1817
1818 j = 0;
1819 } while (++i < MAX_LINKS);
1820
1821 return NULL;
1822}
1823
1824static void netlink_seq_stop(struct seq_file *seq, void *v)
Eric Dumazet9a429c42008-01-01 21:58:02 -08001825 __releases(nl_table_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001826{
1827 read_unlock(&nl_table_lock);
1828}
1829
1830
1831static int netlink_seq_show(struct seq_file *seq, void *v)
1832{
1833 if (v == SEQ_START_TOKEN)
1834 seq_puts(seq,
1835 "sk Eth Pid Groups "
1836 "Rmem Wmem Dump Locks\n");
1837 else {
1838 struct sock *s = v;
1839 struct netlink_sock *nlk = nlk_sk(s);
1840
1841 seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %d\n",
1842 s,
1843 s->sk_protocol,
1844 nlk->pid,
Patrick McHardy513c2502005-09-06 15:43:59 -07001845 nlk->groups ? (u32)nlk->groups[0] : 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001846 atomic_read(&s->sk_rmem_alloc),
1847 atomic_read(&s->sk_wmem_alloc),
1848 nlk->cb,
1849 atomic_read(&s->sk_refcnt)
1850 );
1851
1852 }
1853 return 0;
1854}
1855
Philippe De Muyter56b3d972007-07-10 23:07:31 -07001856static const struct seq_operations netlink_seq_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001857 .start = netlink_seq_start,
1858 .next = netlink_seq_next,
1859 .stop = netlink_seq_stop,
1860 .show = netlink_seq_show,
1861};
1862
1863
1864static int netlink_seq_open(struct inode *inode, struct file *file)
1865{
Denis V. Luneve372c412007-11-19 22:31:54 -08001866 return seq_open_net(inode, file, &netlink_seq_ops,
1867 sizeof(struct nl_seq_iter));
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001868}
1869
Arjan van de Venda7071d2007-02-12 00:55:36 -08001870static const struct file_operations netlink_seq_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001871 .owner = THIS_MODULE,
1872 .open = netlink_seq_open,
1873 .read = seq_read,
1874 .llseek = seq_lseek,
Denis V. Luneve372c412007-11-19 22:31:54 -08001875 .release = seq_release_net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001876};
1877
1878#endif
1879
1880int netlink_register_notifier(struct notifier_block *nb)
1881{
Alan Sterne041c682006-03-27 01:16:30 -08001882 return atomic_notifier_chain_register(&netlink_chain, nb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001883}
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001884EXPORT_SYMBOL(netlink_register_notifier);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001885
1886int netlink_unregister_notifier(struct notifier_block *nb)
1887{
Alan Sterne041c682006-03-27 01:16:30 -08001888 return atomic_notifier_chain_unregister(&netlink_chain, nb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001889}
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001890EXPORT_SYMBOL(netlink_unregister_notifier);
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +09001891
Eric Dumazet90ddc4f2005-12-22 12:49:22 -08001892static const struct proto_ops netlink_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001893 .family = PF_NETLINK,
1894 .owner = THIS_MODULE,
1895 .release = netlink_release,
1896 .bind = netlink_bind,
1897 .connect = netlink_connect,
1898 .socketpair = sock_no_socketpair,
1899 .accept = sock_no_accept,
1900 .getname = netlink_getname,
1901 .poll = datagram_poll,
1902 .ioctl = sock_no_ioctl,
1903 .listen = sock_no_listen,
1904 .shutdown = sock_no_shutdown,
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001905 .setsockopt = netlink_setsockopt,
1906 .getsockopt = netlink_getsockopt,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001907 .sendmsg = netlink_sendmsg,
1908 .recvmsg = netlink_recvmsg,
1909 .mmap = sock_no_mmap,
1910 .sendpage = sock_no_sendpage,
1911};
1912
1913static struct net_proto_family netlink_family_ops = {
1914 .family = PF_NETLINK,
1915 .create = netlink_create,
1916 .owner = THIS_MODULE, /* for consistency 8) */
1917};
1918
Pavel Emelyanov46650792007-10-08 20:38:39 -07001919static int __net_init netlink_net_init(struct net *net)
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001920{
1921#ifdef CONFIG_PROC_FS
1922 if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops))
1923 return -ENOMEM;
1924#endif
1925 return 0;
1926}
1927
Pavel Emelyanov46650792007-10-08 20:38:39 -07001928static void __net_exit netlink_net_exit(struct net *net)
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001929{
1930#ifdef CONFIG_PROC_FS
1931 proc_net_remove(net, "netlink");
1932#endif
1933}
1934
Denis V. Lunev022cbae2007-11-13 03:23:50 -08001935static struct pernet_operations __net_initdata netlink_net_ops = {
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001936 .init = netlink_net_init,
1937 .exit = netlink_net_exit,
1938};
1939
Linus Torvalds1da177e2005-04-16 15:20:36 -07001940static int __init netlink_proto_init(void)
1941{
1942 struct sk_buff *dummy_skb;
1943 int i;
Denis Cheng26ff5dd2007-09-16 16:36:02 -07001944 unsigned long limit;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001945 unsigned int order;
1946 int err = proto_register(&netlink_proto, 0);
1947
1948 if (err != 0)
1949 goto out;
1950
YOSHIFUJI Hideakief047f52006-09-01 00:29:06 -07001951 BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001952
Panagiotis Issaris0da974f2006-07-21 14:51:30 -07001953 nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);
Akinobu Mitafab2caf2006-08-29 02:15:24 -07001954 if (!nl_table)
1955 goto panic;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001956
Linus Torvalds1da177e2005-04-16 15:20:36 -07001957 if (num_physpages >= (128 * 1024))
Denis Cheng26ff5dd2007-09-16 16:36:02 -07001958 limit = num_physpages >> (21 - PAGE_SHIFT);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001959 else
Denis Cheng26ff5dd2007-09-16 16:36:02 -07001960 limit = num_physpages >> (23 - PAGE_SHIFT);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001961
Denis Cheng26ff5dd2007-09-16 16:36:02 -07001962 order = get_bitmask_order(limit) - 1 + PAGE_SHIFT;
1963 limit = (1UL << order) / sizeof(struct hlist_head);
1964 order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001965
1966 for (i = 0; i < MAX_LINKS; i++) {
1967 struct nl_pid_hash *hash = &nl_table[i].hash;
1968
Eric Dumazetea729122007-12-11 02:09:47 -08001969 hash->table = nl_pid_hash_zalloc(1 * sizeof(*hash->table));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001970 if (!hash->table) {
1971 while (i-- > 0)
1972 nl_pid_hash_free(nl_table[i].hash.table,
1973 1 * sizeof(*hash->table));
1974 kfree(nl_table);
Akinobu Mitafab2caf2006-08-29 02:15:24 -07001975 goto panic;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001976 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001977 hash->max_shift = order;
1978 hash->shift = 0;
1979 hash->mask = 0;
1980 hash->rehash_time = jiffies;
1981 }
1982
1983 sock_register(&netlink_family_ops);
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001984 register_pernet_subsys(&netlink_net_ops);
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +09001985 /* The netlink device handler may be needed early. */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001986 rtnetlink_init();
1987out:
1988 return err;
Akinobu Mitafab2caf2006-08-29 02:15:24 -07001989panic:
1990 panic("netlink_init: Cannot allocate nl_table\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001991}
1992
Linus Torvalds1da177e2005-04-16 15:20:36 -07001993core_initcall(netlink_proto_init);