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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * NETLINK Kernel-user communication protocol.
3 *
Alan Cox113aa832008-10-13 19:01:08 -07004 * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk>
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 * 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>
Patrick McHardyaf65bdf2007-04-20 14:14:21 -070057#include <linux/mutex.h>
Andrew Morton54e0f522005-04-30 07:07:04 +010058
Eric W. Biederman457c4cb2007-09-12 12:01:34 +020059#include <net/net_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070060#include <net/sock.h>
61#include <net/scm.h>
Thomas Graf82ace472005-11-10 02:25:53 +010062#include <net/netlink.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
Patrick McHardyf7fa9b12005-08-15 12:29:13 -070064#define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8)
Johannes Bergb4ff4f02007-07-18 15:46:06 -070065#define NLGRPLONGS(x) (NLGRPSZ(x)/sizeof(unsigned long))
Linus Torvalds1da177e2005-04-16 15:20:36 -070066
67struct netlink_sock {
68 /* struct sock has to be the first member of netlink_sock */
69 struct sock sk;
70 u32 pid;
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 u32 dst_pid;
Patrick McHardyd629b832005-08-14 19:27:50 -070072 u32 dst_group;
Patrick McHardyf7fa9b12005-08-15 12:29:13 -070073 u32 flags;
74 u32 subscriptions;
75 u32 ngroups;
76 unsigned long *groups;
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 unsigned long state;
78 wait_queue_head_t wait;
79 struct netlink_callback *cb;
Patrick McHardyaf65bdf2007-04-20 14:14:21 -070080 struct mutex *cb_mutex;
81 struct mutex cb_def_mutex;
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -070082 void (*netlink_rcv)(struct sk_buff *skb);
Patrick McHardy77247bb2005-08-14 19:27:13 -070083 struct module *module;
Linus Torvalds1da177e2005-04-16 15:20:36 -070084};
85
Eric Dumazet5c398dc2010-10-24 04:27:10 +000086struct listeners {
87 struct rcu_head rcu;
88 unsigned long masks[0];
Johannes Berg6c04bb12009-07-10 09:51:32 +000089};
90
Patrick McHardy77247bb2005-08-14 19:27:13 -070091#define NETLINK_KERNEL_SOCKET 0x1
Patrick McHardy9a4595b2005-08-15 12:32:15 -070092#define NETLINK_RECV_PKTINFO 0x2
Pablo Neira Ayusobe0c22a2009-02-18 01:40:43 +000093#define NETLINK_BROADCAST_SEND_ERROR 0x4
Pablo Neira Ayuso38938bf2009-03-24 16:37:55 -070094#define NETLINK_RECV_NO_ENOBUFS 0x8
Patrick McHardy77247bb2005-08-14 19:27:13 -070095
Linus Torvalds1da177e2005-04-16 15:20:36 -070096static inline struct netlink_sock *nlk_sk(struct sock *sk)
97{
Denis Cheng32b21e02007-08-28 15:41:11 -070098 return container_of(sk, struct netlink_sock, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -070099}
100
Denis V. Lunevaed81562007-10-10 21:14:32 -0700101static inline int netlink_is_kernel(struct sock *sk)
102{
103 return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET;
104}
105
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106struct nl_pid_hash {
107 struct hlist_head *table;
108 unsigned long rehash_time;
109
110 unsigned int mask;
111 unsigned int shift;
112
113 unsigned int entries;
114 unsigned int max_shift;
115
116 u32 rnd;
117};
118
119struct netlink_table {
120 struct nl_pid_hash hash;
121 struct hlist_head mc_list;
Eric Dumazet5c398dc2010-10-24 04:27:10 +0000122 struct listeners __rcu *listeners;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 unsigned int nl_nonroot;
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700124 unsigned int groups;
Patrick McHardyaf65bdf2007-04-20 14:14:21 -0700125 struct mutex *cb_mutex;
Patrick McHardy77247bb2005-08-14 19:27:13 -0700126 struct module *module;
Patrick McHardyab33a172005-08-14 19:31:36 -0700127 int registered;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128};
129
130static struct netlink_table *nl_table;
131
132static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
133
134static int netlink_dump(struct sock *sk);
135static void netlink_destroy_callback(struct netlink_callback *cb);
136
137static DEFINE_RWLOCK(nl_table_lock);
138static atomic_t nl_table_users = ATOMIC_INIT(0);
139
Alan Sterne041c682006-03-27 01:16:30 -0800140static ATOMIC_NOTIFIER_HEAD(netlink_chain);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141
Patrick McHardyd629b832005-08-14 19:27:50 -0700142static u32 netlink_group_mask(u32 group)
143{
144 return group ? 1 << (group - 1) : 0;
145}
146
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid)
148{
149 return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask];
150}
151
152static void netlink_sock_destruct(struct sock *sk)
153{
Herbert Xu3f660d62007-05-03 03:17:14 -0700154 struct netlink_sock *nlk = nlk_sk(sk);
155
Herbert Xu3f660d62007-05-03 03:17:14 -0700156 if (nlk->cb) {
157 if (nlk->cb->done)
158 nlk->cb->done(nlk->cb);
159 netlink_destroy_callback(nlk->cb);
160 }
161
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 skb_queue_purge(&sk->sk_receive_queue);
163
164 if (!sock_flag(sk, SOCK_DEAD)) {
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800165 printk(KERN_ERR "Freeing alive netlink socket %p\n", sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 return;
167 }
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700168
169 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
170 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
171 WARN_ON(nlk_sk(sk)->groups);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172}
173
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800174/* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on
175 * SMP. Look, when several writers sleep and reader wakes them up, all but one
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 * immediately hit write lock and grab all the cpus. Exclusive sleep solves
177 * this, _but_ remember, it adds useless work on UP machines.
178 */
179
Johannes Bergd136f1b2009-09-12 03:03:15 +0000180void netlink_table_grab(void)
Eric Dumazet9a429c42008-01-01 21:58:02 -0800181 __acquires(nl_table_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182{
Johannes Bergd136f1b2009-09-12 03:03:15 +0000183 might_sleep();
184
Arjan van de Ven6abd2192006-07-03 00:24:07 -0700185 write_lock_irq(&nl_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186
187 if (atomic_read(&nl_table_users)) {
188 DECLARE_WAITQUEUE(wait, current);
189
190 add_wait_queue_exclusive(&nl_table_wait, &wait);
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800191 for (;;) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 set_current_state(TASK_UNINTERRUPTIBLE);
193 if (atomic_read(&nl_table_users) == 0)
194 break;
Arjan van de Ven6abd2192006-07-03 00:24:07 -0700195 write_unlock_irq(&nl_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 schedule();
Arjan van de Ven6abd2192006-07-03 00:24:07 -0700197 write_lock_irq(&nl_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 }
199
200 __set_current_state(TASK_RUNNING);
201 remove_wait_queue(&nl_table_wait, &wait);
202 }
203}
204
Johannes Bergd136f1b2009-09-12 03:03:15 +0000205void netlink_table_ungrab(void)
Eric Dumazet9a429c42008-01-01 21:58:02 -0800206 __releases(nl_table_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207{
Arjan van de Ven6abd2192006-07-03 00:24:07 -0700208 write_unlock_irq(&nl_table_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 wake_up(&nl_table_wait);
210}
211
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800212static inline void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213netlink_lock_table(void)
214{
215 /* read_lock() synchronizes us to netlink_table_grab */
216
217 read_lock(&nl_table_lock);
218 atomic_inc(&nl_table_users);
219 read_unlock(&nl_table_lock);
220}
221
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800222static inline void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223netlink_unlock_table(void)
224{
225 if (atomic_dec_and_test(&nl_table_users))
226 wake_up(&nl_table_wait);
227}
228
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800229static inline struct sock *netlink_lookup(struct net *net, int protocol,
230 u32 pid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231{
232 struct nl_pid_hash *hash = &nl_table[protocol].hash;
233 struct hlist_head *head;
234 struct sock *sk;
235 struct hlist_node *node;
236
237 read_lock(&nl_table_lock);
238 head = nl_pid_hashfn(hash, pid);
239 sk_for_each(sk, node, head) {
YOSHIFUJI Hideaki878628f2008-03-26 03:57:35 +0900240 if (net_eq(sock_net(sk), net) && (nlk_sk(sk)->pid == pid)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 sock_hold(sk);
242 goto found;
243 }
244 }
245 sk = NULL;
246found:
247 read_unlock(&nl_table_lock);
248 return sk;
249}
250
Eric Dumazetea729122007-12-11 02:09:47 -0800251static inline struct hlist_head *nl_pid_hash_zalloc(size_t size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252{
253 if (size <= PAGE_SIZE)
Eric Dumazetea729122007-12-11 02:09:47 -0800254 return kzalloc(size, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 else
256 return (struct hlist_head *)
Eric Dumazetea729122007-12-11 02:09:47 -0800257 __get_free_pages(GFP_ATOMIC | __GFP_ZERO,
258 get_order(size));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259}
260
261static inline void nl_pid_hash_free(struct hlist_head *table, size_t size)
262{
263 if (size <= PAGE_SIZE)
264 kfree(table);
265 else
266 free_pages((unsigned long)table, get_order(size));
267}
268
269static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow)
270{
271 unsigned int omask, mask, shift;
272 size_t osize, size;
273 struct hlist_head *otable, *table;
274 int i;
275
276 omask = mask = hash->mask;
277 osize = size = (mask + 1) * sizeof(*table);
278 shift = hash->shift;
279
280 if (grow) {
281 if (++shift > hash->max_shift)
282 return 0;
283 mask = mask * 2 + 1;
284 size *= 2;
285 }
286
Eric Dumazetea729122007-12-11 02:09:47 -0800287 table = nl_pid_hash_zalloc(size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 if (!table)
289 return 0;
290
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 otable = hash->table;
292 hash->table = table;
293 hash->mask = mask;
294 hash->shift = shift;
295 get_random_bytes(&hash->rnd, sizeof(hash->rnd));
296
297 for (i = 0; i <= omask; i++) {
298 struct sock *sk;
299 struct hlist_node *node, *tmp;
300
301 sk_for_each_safe(sk, node, tmp, &otable[i])
302 __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid));
303 }
304
305 nl_pid_hash_free(otable, osize);
306 hash->rehash_time = jiffies + 10 * 60 * HZ;
307 return 1;
308}
309
310static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len)
311{
312 int avg = hash->entries >> hash->shift;
313
314 if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1))
315 return 1;
316
317 if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) {
318 nl_pid_hash_rehash(hash, 0);
319 return 1;
320 }
321
322 return 0;
323}
324
Eric Dumazet90ddc4f2005-12-22 12:49:22 -0800325static const struct proto_ops netlink_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326
Patrick McHardy4277a082006-03-20 18:52:01 -0800327static void
328netlink_update_listeners(struct sock *sk)
329{
330 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
331 struct hlist_node *node;
332 unsigned long mask;
333 unsigned int i;
334
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700335 for (i = 0; i < NLGRPLONGS(tbl->groups); i++) {
Patrick McHardy4277a082006-03-20 18:52:01 -0800336 mask = 0;
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700337 sk_for_each_bound(sk, node, &tbl->mc_list) {
338 if (i < NLGRPLONGS(nlk_sk(sk)->ngroups))
339 mask |= nlk_sk(sk)->groups[i];
340 }
Eric Dumazet5c398dc2010-10-24 04:27:10 +0000341 tbl->listeners->masks[i] = mask;
Patrick McHardy4277a082006-03-20 18:52:01 -0800342 }
343 /* this function is only called with the netlink table "grabbed", which
344 * makes sure updates are visible before bind or setsockopt return. */
345}
346
Eric W. Biedermanb4b51022007-09-12 13:05:38 +0200347static int netlink_insert(struct sock *sk, struct net *net, u32 pid)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348{
349 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
350 struct hlist_head *head;
351 int err = -EADDRINUSE;
352 struct sock *osk;
353 struct hlist_node *node;
354 int len;
355
356 netlink_table_grab();
357 head = nl_pid_hashfn(hash, pid);
358 len = 0;
359 sk_for_each(osk, node, head) {
YOSHIFUJI Hideaki878628f2008-03-26 03:57:35 +0900360 if (net_eq(sock_net(osk), net) && (nlk_sk(osk)->pid == pid))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 break;
362 len++;
363 }
364 if (node)
365 goto err;
366
367 err = -EBUSY;
368 if (nlk_sk(sk)->pid)
369 goto err;
370
371 err = -ENOMEM;
372 if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX))
373 goto err;
374
375 if (len && nl_pid_hash_dilute(hash, len))
376 head = nl_pid_hashfn(hash, pid);
377 hash->entries++;
378 nlk_sk(sk)->pid = pid;
379 sk_add_node(sk, head);
380 err = 0;
381
382err:
383 netlink_table_ungrab();
384 return err;
385}
386
387static void netlink_remove(struct sock *sk)
388{
389 netlink_table_grab();
David S. Millerd470e3b2005-06-26 15:31:51 -0700390 if (sk_del_node_init(sk))
391 nl_table[sk->sk_protocol].hash.entries--;
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700392 if (nlk_sk(sk)->subscriptions)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 __sk_del_bind_node(sk);
394 netlink_table_ungrab();
395}
396
397static struct proto netlink_proto = {
398 .name = "NETLINK",
399 .owner = THIS_MODULE,
400 .obj_size = sizeof(struct netlink_sock),
401};
402
Eric W. Biederman1b8d7ae2007-10-08 23:24:22 -0700403static int __netlink_create(struct net *net, struct socket *sock,
404 struct mutex *cb_mutex, int protocol)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405{
406 struct sock *sk;
407 struct netlink_sock *nlk;
Patrick McHardyab33a172005-08-14 19:31:36 -0700408
409 sock->ops = &netlink_ops;
410
Pavel Emelyanov6257ff22007-11-01 00:39:31 -0700411 sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto);
Patrick McHardyab33a172005-08-14 19:31:36 -0700412 if (!sk)
413 return -ENOMEM;
414
415 sock_init_data(sock, sk);
416
417 nlk = nlk_sk(sk);
Patrick McHardyffa4d722007-04-25 14:01:17 -0700418 if (cb_mutex)
419 nlk->cb_mutex = cb_mutex;
420 else {
421 nlk->cb_mutex = &nlk->cb_def_mutex;
422 mutex_init(nlk->cb_mutex);
423 }
Patrick McHardyab33a172005-08-14 19:31:36 -0700424 init_waitqueue_head(&nlk->wait);
425
426 sk->sk_destruct = netlink_sock_destruct;
427 sk->sk_protocol = protocol;
428 return 0;
429}
430
Eric Paris3f378b62009-11-05 22:18:14 -0800431static int netlink_create(struct net *net, struct socket *sock, int protocol,
432 int kern)
Patrick McHardyab33a172005-08-14 19:31:36 -0700433{
434 struct module *module = NULL;
Patrick McHardyaf65bdf2007-04-20 14:14:21 -0700435 struct mutex *cb_mutex;
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700436 struct netlink_sock *nlk;
Patrick McHardyab33a172005-08-14 19:31:36 -0700437 int err = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438
439 sock->state = SS_UNCONNECTED;
440
441 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
442 return -ESOCKTNOSUPPORT;
443
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800444 if (protocol < 0 || protocol >= MAX_LINKS)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 return -EPROTONOSUPPORT;
446
Patrick McHardy77247bb2005-08-14 19:27:13 -0700447 netlink_lock_table();
Johannes Berg95a5afc2008-10-16 15:24:51 -0700448#ifdef CONFIG_MODULES
Patrick McHardyab33a172005-08-14 19:31:36 -0700449 if (!nl_table[protocol].registered) {
Patrick McHardy77247bb2005-08-14 19:27:13 -0700450 netlink_unlock_table();
Harald Welte4fdb3bb2005-08-09 19:40:55 -0700451 request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
Patrick McHardy77247bb2005-08-14 19:27:13 -0700452 netlink_lock_table();
Harald Welte4fdb3bb2005-08-09 19:40:55 -0700453 }
Patrick McHardyab33a172005-08-14 19:31:36 -0700454#endif
455 if (nl_table[protocol].registered &&
456 try_module_get(nl_table[protocol].module))
457 module = nl_table[protocol].module;
Alexey Dobriyan974c37e2010-01-30 10:05:05 +0000458 else
459 err = -EPROTONOSUPPORT;
Patrick McHardyaf65bdf2007-04-20 14:14:21 -0700460 cb_mutex = nl_table[protocol].cb_mutex;
Patrick McHardy77247bb2005-08-14 19:27:13 -0700461 netlink_unlock_table();
Harald Welte4fdb3bb2005-08-09 19:40:55 -0700462
Alexey Dobriyan974c37e2010-01-30 10:05:05 +0000463 if (err < 0)
464 goto out;
465
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800466 err = __netlink_create(net, sock, cb_mutex, protocol);
467 if (err < 0)
Patrick McHardyab33a172005-08-14 19:31:36 -0700468 goto out_module;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469
David S. Miller6f756a82008-11-23 17:34:03 -0800470 local_bh_disable();
Eric Dumazetc1fd3b92008-11-23 15:48:22 -0800471 sock_prot_inuse_add(net, &netlink_proto, 1);
David S. Miller6f756a82008-11-23 17:34:03 -0800472 local_bh_enable();
473
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700474 nlk = nlk_sk(sock->sk);
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700475 nlk->module = module;
Patrick McHardyab33a172005-08-14 19:31:36 -0700476out:
477 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478
Patrick McHardyab33a172005-08-14 19:31:36 -0700479out_module:
480 module_put(module);
481 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482}
483
484static int netlink_release(struct socket *sock)
485{
486 struct sock *sk = sock->sk;
487 struct netlink_sock *nlk;
488
489 if (!sk)
490 return 0;
491
492 netlink_remove(sk);
Denis Lunevac57b3a2007-04-18 17:05:58 -0700493 sock_orphan(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 nlk = nlk_sk(sk);
495
Herbert Xu3f660d62007-05-03 03:17:14 -0700496 /*
497 * OK. Socket is unlinked, any packets that arrive now
498 * will be purged.
499 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 sock->sk = NULL;
502 wake_up_interruptible_all(&nlk->wait);
503
504 skb_queue_purge(&sk->sk_write_queue);
505
Johannes Berg649300b2009-11-16 12:05:34 +0000506 if (nlk->pid) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 struct netlink_notify n = {
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900508 .net = sock_net(sk),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 .protocol = sk->sk_protocol,
510 .pid = nlk->pid,
511 };
Alan Sterne041c682006-03-27 01:16:30 -0800512 atomic_notifier_call_chain(&netlink_chain,
513 NETLINK_URELEASE, &n);
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +0900514 }
Harald Welte4fdb3bb2005-08-09 19:40:55 -0700515
Mariusz Kozlowski5e7c0012007-01-02 15:24:30 -0800516 module_put(nlk->module);
Harald Welte4fdb3bb2005-08-09 19:40:55 -0700517
Patrick McHardy4277a082006-03-20 18:52:01 -0800518 netlink_table_grab();
Denis V. Lunevaed81562007-10-10 21:14:32 -0700519 if (netlink_is_kernel(sk)) {
Denis V. Lunev869e58f2008-01-18 23:53:31 -0800520 BUG_ON(nl_table[sk->sk_protocol].registered == 0);
521 if (--nl_table[sk->sk_protocol].registered == 0) {
522 kfree(nl_table[sk->sk_protocol].listeners);
523 nl_table[sk->sk_protocol].module = NULL;
524 nl_table[sk->sk_protocol].registered = 0;
525 }
Patrick McHardy4277a082006-03-20 18:52:01 -0800526 } else if (nlk->subscriptions)
527 netlink_update_listeners(sk);
528 netlink_table_ungrab();
Patrick McHardy77247bb2005-08-14 19:27:13 -0700529
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700530 kfree(nlk->groups);
531 nlk->groups = NULL;
532
Eric Dumazet37558102008-11-24 14:05:22 -0800533 local_bh_disable();
Eric Dumazetc1fd3b92008-11-23 15:48:22 -0800534 sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1);
Eric Dumazet37558102008-11-24 14:05:22 -0800535 local_bh_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 sock_put(sk);
537 return 0;
538}
539
540static int netlink_autobind(struct socket *sock)
541{
542 struct sock *sk = sock->sk;
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900543 struct net *net = sock_net(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
545 struct hlist_head *head;
546 struct sock *osk;
547 struct hlist_node *node;
Tom Goff66aa4a52010-03-19 15:38:50 +0000548 s32 pid = task_tgid_vnr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 int err;
550 static s32 rover = -4097;
551
552retry:
553 cond_resched();
554 netlink_table_grab();
555 head = nl_pid_hashfn(hash, pid);
556 sk_for_each(osk, node, head) {
YOSHIFUJI Hideaki878628f2008-03-26 03:57:35 +0900557 if (!net_eq(sock_net(osk), net))
Eric W. Biedermanb4b51022007-09-12 13:05:38 +0200558 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 if (nlk_sk(osk)->pid == pid) {
560 /* Bind collision, search negative pid values. */
561 pid = rover--;
562 if (rover > -4097)
563 rover = -4097;
564 netlink_table_ungrab();
565 goto retry;
566 }
567 }
568 netlink_table_ungrab();
569
Eric W. Biedermanb4b51022007-09-12 13:05:38 +0200570 err = netlink_insert(sk, net, pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571 if (err == -EADDRINUSE)
572 goto retry;
David S. Millerd470e3b2005-06-26 15:31:51 -0700573
574 /* If 2 threads race to autobind, that is fine. */
575 if (err == -EBUSY)
576 err = 0;
577
578 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579}
580
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +0900581static inline int netlink_capable(struct socket *sock, unsigned int flag)
582{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) ||
584 capable(CAP_NET_ADMIN);
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +0900585}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700587static void
588netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions)
589{
590 struct netlink_sock *nlk = nlk_sk(sk);
591
592 if (nlk->subscriptions && !subscriptions)
593 __sk_del_bind_node(sk);
594 else if (!nlk->subscriptions && subscriptions)
595 sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
596 nlk->subscriptions = subscriptions;
597}
598
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700599static int netlink_realloc_groups(struct sock *sk)
Patrick McHardy513c2502005-09-06 15:43:59 -0700600{
601 struct netlink_sock *nlk = nlk_sk(sk);
602 unsigned int groups;
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700603 unsigned long *new_groups;
Patrick McHardy513c2502005-09-06 15:43:59 -0700604 int err = 0;
605
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700606 netlink_table_grab();
607
Patrick McHardy513c2502005-09-06 15:43:59 -0700608 groups = nl_table[sk->sk_protocol].groups;
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700609 if (!nl_table[sk->sk_protocol].registered) {
Patrick McHardy513c2502005-09-06 15:43:59 -0700610 err = -ENOENT;
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700611 goto out_unlock;
612 }
Patrick McHardy513c2502005-09-06 15:43:59 -0700613
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700614 if (nlk->ngroups >= groups)
615 goto out_unlock;
Patrick McHardy513c2502005-09-06 15:43:59 -0700616
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700617 new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC);
618 if (new_groups == NULL) {
619 err = -ENOMEM;
620 goto out_unlock;
621 }
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800622 memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0,
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700623 NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups));
624
625 nlk->groups = new_groups;
Patrick McHardy513c2502005-09-06 15:43:59 -0700626 nlk->ngroups = groups;
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700627 out_unlock:
628 netlink_table_ungrab();
629 return err;
Patrick McHardy513c2502005-09-06 15:43:59 -0700630}
631
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800632static int netlink_bind(struct socket *sock, struct sockaddr *addr,
633 int addr_len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634{
635 struct sock *sk = sock->sk;
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900636 struct net *net = sock_net(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 struct netlink_sock *nlk = nlk_sk(sk);
638 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
639 int err;
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +0900640
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641 if (nladdr->nl_family != AF_NETLINK)
642 return -EINVAL;
643
644 /* Only superuser is allowed to listen multicasts */
Patrick McHardy513c2502005-09-06 15:43:59 -0700645 if (nladdr->nl_groups) {
646 if (!netlink_capable(sock, NL_NONROOT_RECV))
647 return -EPERM;
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700648 err = netlink_realloc_groups(sk);
649 if (err)
650 return err;
Patrick McHardy513c2502005-09-06 15:43:59 -0700651 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652
653 if (nlk->pid) {
654 if (nladdr->nl_pid != nlk->pid)
655 return -EINVAL;
656 } else {
657 err = nladdr->nl_pid ?
Eric W. Biedermanb4b51022007-09-12 13:05:38 +0200658 netlink_insert(sk, net, nladdr->nl_pid) :
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 netlink_autobind(sock);
660 if (err)
661 return err;
662 }
663
Patrick McHardy513c2502005-09-06 15:43:59 -0700664 if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 return 0;
666
667 netlink_table_grab();
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700668 netlink_update_subscriptions(sk, nlk->subscriptions +
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +0900669 hweight32(nladdr->nl_groups) -
670 hweight32(nlk->groups[0]));
671 nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups;
Patrick McHardy4277a082006-03-20 18:52:01 -0800672 netlink_update_listeners(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673 netlink_table_ungrab();
674
675 return 0;
676}
677
678static int netlink_connect(struct socket *sock, struct sockaddr *addr,
679 int alen, int flags)
680{
681 int err = 0;
682 struct sock *sk = sock->sk;
683 struct netlink_sock *nlk = nlk_sk(sk);
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800684 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685
Changli Gao6503d962010-03-31 22:58:26 +0000686 if (alen < sizeof(addr->sa_family))
687 return -EINVAL;
688
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689 if (addr->sa_family == AF_UNSPEC) {
690 sk->sk_state = NETLINK_UNCONNECTED;
691 nlk->dst_pid = 0;
Patrick McHardyd629b832005-08-14 19:27:50 -0700692 nlk->dst_group = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 return 0;
694 }
695 if (addr->sa_family != AF_NETLINK)
696 return -EINVAL;
697
698 /* Only superuser is allowed to send multicasts */
699 if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND))
700 return -EPERM;
701
702 if (!nlk->pid)
703 err = netlink_autobind(sock);
704
705 if (err == 0) {
706 sk->sk_state = NETLINK_CONNECTED;
707 nlk->dst_pid = nladdr->nl_pid;
Patrick McHardyd629b832005-08-14 19:27:50 -0700708 nlk->dst_group = ffs(nladdr->nl_groups);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 }
710
711 return err;
712}
713
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800714static int netlink_getname(struct socket *sock, struct sockaddr *addr,
715 int *addr_len, int peer)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716{
717 struct sock *sk = sock->sk;
718 struct netlink_sock *nlk = nlk_sk(sk);
Cyrill Gorcunov13cfa972009-11-08 05:51:19 +0000719 DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr);
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +0900720
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 nladdr->nl_family = AF_NETLINK;
722 nladdr->nl_pad = 0;
723 *addr_len = sizeof(*nladdr);
724
725 if (peer) {
726 nladdr->nl_pid = nlk->dst_pid;
Patrick McHardyd629b832005-08-14 19:27:50 -0700727 nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 } else {
729 nladdr->nl_pid = nlk->pid;
Patrick McHardy513c2502005-09-06 15:43:59 -0700730 nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 }
732 return 0;
733}
734
735static void netlink_overrun(struct sock *sk)
736{
Pablo Neira Ayuso38938bf2009-03-24 16:37:55 -0700737 struct netlink_sock *nlk = nlk_sk(sk);
738
739 if (!(nlk->flags & NETLINK_RECV_NO_ENOBUFS)) {
740 if (!test_and_set_bit(0, &nlk_sk(sk)->state)) {
741 sk->sk_err = ENOBUFS;
742 sk->sk_error_report(sk);
743 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 }
Pablo Neira Ayuso38938bf2009-03-24 16:37:55 -0700745 atomic_inc(&sk->sk_drops);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746}
747
748static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid)
749{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 struct sock *sock;
751 struct netlink_sock *nlk;
752
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900753 sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 if (!sock)
755 return ERR_PTR(-ECONNREFUSED);
756
757 /* Don't bother queuing skb if kernel socket has no input function */
758 nlk = nlk_sk(sock);
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700759 if (sock->sk_state == NETLINK_CONNECTED &&
760 nlk->dst_pid != nlk_sk(ssk)->pid) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 sock_put(sock);
762 return ERR_PTR(-ECONNREFUSED);
763 }
764 return sock;
765}
766
767struct sock *netlink_getsockbyfilp(struct file *filp)
768{
Josef Sipek6db5fc52006-12-08 02:37:25 -0800769 struct inode *inode = filp->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770 struct sock *sock;
771
772 if (!S_ISSOCK(inode->i_mode))
773 return ERR_PTR(-ENOTSOCK);
774
775 sock = SOCKET_I(inode)->sk;
776 if (sock->sk_family != AF_NETLINK)
777 return ERR_PTR(-EINVAL);
778
779 sock_hold(sock);
780 return sock;
781}
782
783/*
784 * Attach a skb to a netlink socket.
785 * The caller must hold a reference to the destination socket. On error, the
786 * reference is dropped. The skb is not send to the destination, just all
787 * all error checks are performed and memory in the queue is reserved.
788 * Return values:
789 * < 0: error. skb freed, reference to sock dropped.
790 * 0: continue
791 * 1: repeat lookup - reference dropped while waiting for socket memory.
792 */
Denis V. Lunev9457afe2008-06-05 11:23:39 -0700793int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
Patrick McHardyc3d8d1e2007-11-07 02:42:09 -0800794 long *timeo, struct sock *ssk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795{
796 struct netlink_sock *nlk;
797
798 nlk = nlk_sk(sk);
799
800 if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
801 test_bit(0, &nlk->state)) {
802 DECLARE_WAITQUEUE(wait, current);
Patrick McHardyc3d8d1e2007-11-07 02:42:09 -0800803 if (!*timeo) {
Denis V. Lunevaed81562007-10-10 21:14:32 -0700804 if (!ssk || netlink_is_kernel(ssk))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 netlink_overrun(sk);
806 sock_put(sk);
807 kfree_skb(skb);
808 return -EAGAIN;
809 }
810
811 __set_current_state(TASK_INTERRUPTIBLE);
812 add_wait_queue(&nlk->wait, &wait);
813
814 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
815 test_bit(0, &nlk->state)) &&
816 !sock_flag(sk, SOCK_DEAD))
Patrick McHardyc3d8d1e2007-11-07 02:42:09 -0800817 *timeo = schedule_timeout(*timeo);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818
819 __set_current_state(TASK_RUNNING);
820 remove_wait_queue(&nlk->wait, &wait);
821 sock_put(sk);
822
823 if (signal_pending(current)) {
824 kfree_skb(skb);
Patrick McHardyc3d8d1e2007-11-07 02:42:09 -0800825 return sock_intr_errno(*timeo);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826 }
827 return 1;
828 }
829 skb_set_owner_r(skb, sk);
830 return 0;
831}
832
Denis V. Lunev7ee015e2007-10-10 21:14:03 -0700833int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835 int len = skb->len;
836
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837 skb_queue_tail(&sk->sk_receive_queue, skb);
838 sk->sk_data_ready(sk, len);
839 sock_put(sk);
840 return len;
841}
842
843void netlink_detachskb(struct sock *sk, struct sk_buff *skb)
844{
845 kfree_skb(skb);
846 sock_put(sk);
847}
848
Victor Fusco37da6472005-07-18 13:35:43 -0700849static inline struct sk_buff *netlink_trim(struct sk_buff *skb,
Al Virodd0fc662005-10-07 07:46:04 +0100850 gfp_t allocation)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851{
852 int delta;
853
854 skb_orphan(skb);
855
Arnaldo Carvalho de Melo4305b542007-04-19 20:43:29 -0700856 delta = skb->end - skb->tail;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857 if (delta * 2 < skb->truesize)
858 return skb;
859
860 if (skb_shared(skb)) {
861 struct sk_buff *nskb = skb_clone(skb, allocation);
862 if (!nskb)
863 return skb;
864 kfree_skb(skb);
865 skb = nskb;
866 }
867
868 if (!pskb_expand_head(skb, 0, -delta, allocation))
869 skb->truesize -= delta;
870
871 return skb;
872}
873
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700874static inline void netlink_rcv_wake(struct sock *sk)
875{
876 struct netlink_sock *nlk = nlk_sk(sk);
877
878 if (skb_queue_empty(&sk->sk_receive_queue))
879 clear_bit(0, &nlk->state);
880 if (!test_bit(0, &nlk->state))
881 wake_up_interruptible(&nlk->wait);
882}
883
884static inline int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb)
885{
886 int ret;
887 struct netlink_sock *nlk = nlk_sk(sk);
888
889 ret = -ECONNREFUSED;
890 if (nlk->netlink_rcv != NULL) {
891 ret = skb->len;
892 skb_set_owner_r(skb, sk);
893 nlk->netlink_rcv(skb);
894 }
895 kfree_skb(skb);
896 sock_put(sk);
897 return ret;
898}
899
900int netlink_unicast(struct sock *ssk, struct sk_buff *skb,
901 u32 pid, int nonblock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902{
903 struct sock *sk;
904 int err;
905 long timeo;
906
907 skb = netlink_trim(skb, gfp_any());
908
909 timeo = sock_sndtimeo(ssk, nonblock);
910retry:
911 sk = netlink_getsockbypid(ssk, pid);
912 if (IS_ERR(sk)) {
913 kfree_skb(skb);
914 return PTR_ERR(sk);
915 }
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700916 if (netlink_is_kernel(sk))
917 return netlink_unicast_kernel(sk, skb);
918
Stephen Hemmingerb1153f22008-03-21 15:46:12 -0700919 if (sk_filter(sk, skb)) {
Wang Chen84874602008-07-01 19:55:09 -0700920 err = skb->len;
Stephen Hemmingerb1153f22008-03-21 15:46:12 -0700921 kfree_skb(skb);
922 sock_put(sk);
923 return err;
924 }
925
Denis V. Lunev9457afe2008-06-05 11:23:39 -0700926 err = netlink_attachskb(sk, skb, &timeo, ssk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927 if (err == 1)
928 goto retry;
929 if (err)
930 return err;
931
Denis V. Lunev7ee015e2007-10-10 21:14:03 -0700932 return netlink_sendskb(sk, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933}
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800934EXPORT_SYMBOL(netlink_unicast);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935
Patrick McHardy4277a082006-03-20 18:52:01 -0800936int netlink_has_listeners(struct sock *sk, unsigned int group)
937{
938 int res = 0;
Eric Dumazet5c398dc2010-10-24 04:27:10 +0000939 struct listeners *listeners;
Patrick McHardy4277a082006-03-20 18:52:01 -0800940
Denis V. Lunevaed81562007-10-10 21:14:32 -0700941 BUG_ON(!netlink_is_kernel(sk));
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700942
943 rcu_read_lock();
944 listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners);
945
Patrick McHardy4277a082006-03-20 18:52:01 -0800946 if (group - 1 < nl_table[sk->sk_protocol].groups)
Eric Dumazet5c398dc2010-10-24 04:27:10 +0000947 res = test_bit(group - 1, listeners->masks);
Johannes Bergb4ff4f02007-07-18 15:46:06 -0700948
949 rcu_read_unlock();
950
Patrick McHardy4277a082006-03-20 18:52:01 -0800951 return res;
952}
953EXPORT_SYMBOL_GPL(netlink_has_listeners);
954
Patrick McHardy6ac552f2007-12-04 00:19:38 -0800955static inline int netlink_broadcast_deliver(struct sock *sk,
956 struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957{
958 struct netlink_sock *nlk = nlk_sk(sk);
959
960 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
961 !test_bit(0, &nlk->state)) {
962 skb_set_owner_r(skb, sk);
963 skb_queue_tail(&sk->sk_receive_queue, skb);
964 sk->sk_data_ready(sk, skb->len);
965 return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf;
966 }
967 return -1;
968}
969
970struct netlink_broadcast_data {
971 struct sock *exclude_sk;
Eric W. Biedermanb4b51022007-09-12 13:05:38 +0200972 struct net *net;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700973 u32 pid;
974 u32 group;
975 int failure;
Pablo Neira Ayusoff491a72009-02-05 23:56:36 -0800976 int delivery_failure;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977 int congested;
978 int delivered;
Al Viro7d877f32005-10-21 03:20:43 -0400979 gfp_t allocation;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980 struct sk_buff *skb, *skb2;
Eric W. Biederman910a7e92010-05-04 17:36:46 -0700981 int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data);
982 void *tx_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983};
984
985static inline int do_one_broadcast(struct sock *sk,
986 struct netlink_broadcast_data *p)
987{
988 struct netlink_sock *nlk = nlk_sk(sk);
989 int val;
990
991 if (p->exclude_sk == sk)
992 goto out;
993
Patrick McHardyf7fa9b12005-08-15 12:29:13 -0700994 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
995 !test_bit(p->group - 1, nlk->groups))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996 goto out;
997
YOSHIFUJI Hideaki878628f2008-03-26 03:57:35 +0900998 if (!net_eq(sock_net(sk), p->net))
Eric W. Biedermanb4b51022007-09-12 13:05:38 +0200999 goto out;
1000
Linus Torvalds1da177e2005-04-16 15:20:36 -07001001 if (p->failure) {
1002 netlink_overrun(sk);
1003 goto out;
1004 }
1005
1006 sock_hold(sk);
1007 if (p->skb2 == NULL) {
Tommy S. Christensen68acc022005-05-19 13:06:35 -07001008 if (skb_shared(p->skb)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001009 p->skb2 = skb_clone(p->skb, p->allocation);
1010 } else {
Tommy S. Christensen68acc022005-05-19 13:06:35 -07001011 p->skb2 = skb_get(p->skb);
1012 /*
1013 * skb ownership may have been set when
1014 * delivered to a previous socket.
1015 */
1016 skb_orphan(p->skb2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017 }
1018 }
1019 if (p->skb2 == NULL) {
1020 netlink_overrun(sk);
1021 /* Clone failed. Notify ALL listeners. */
1022 p->failure = 1;
Pablo Neira Ayusobe0c22a2009-02-18 01:40:43 +00001023 if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR)
1024 p->delivery_failure = 1;
Eric W. Biederman910a7e92010-05-04 17:36:46 -07001025 } else if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) {
1026 kfree_skb(p->skb2);
1027 p->skb2 = NULL;
Stephen Hemmingerb1153f22008-03-21 15:46:12 -07001028 } else if (sk_filter(sk, p->skb2)) {
1029 kfree_skb(p->skb2);
1030 p->skb2 = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001031 } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) {
1032 netlink_overrun(sk);
Pablo Neira Ayusobe0c22a2009-02-18 01:40:43 +00001033 if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR)
1034 p->delivery_failure = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035 } else {
1036 p->congested |= val;
1037 p->delivered = 1;
1038 p->skb2 = NULL;
1039 }
1040 sock_put(sk);
1041
1042out:
1043 return 0;
1044}
1045
Eric W. Biederman910a7e92010-05-04 17:36:46 -07001046int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 pid,
1047 u32 group, gfp_t allocation,
1048 int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
1049 void *filter_data)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001050{
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +09001051 struct net *net = sock_net(ssk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052 struct netlink_broadcast_data info;
1053 struct hlist_node *node;
1054 struct sock *sk;
1055
1056 skb = netlink_trim(skb, allocation);
1057
1058 info.exclude_sk = ssk;
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001059 info.net = net;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001060 info.pid = pid;
1061 info.group = group;
1062 info.failure = 0;
Pablo Neira Ayusoff491a72009-02-05 23:56:36 -08001063 info.delivery_failure = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001064 info.congested = 0;
1065 info.delivered = 0;
1066 info.allocation = allocation;
1067 info.skb = skb;
1068 info.skb2 = NULL;
Eric W. Biederman910a7e92010-05-04 17:36:46 -07001069 info.tx_filter = filter;
1070 info.tx_data = filter_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001071
1072 /* While we sleep in clone, do not allow to change socket list */
1073
1074 netlink_lock_table();
1075
1076 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
1077 do_one_broadcast(sk, &info);
1078
Neil Horman70d4bf62010-07-20 06:45:56 +00001079 consume_skb(skb);
Tommy S. Christensenaa1c6a62005-05-19 13:07:32 -07001080
Linus Torvalds1da177e2005-04-16 15:20:36 -07001081 netlink_unlock_table();
1082
Neil Horman70d4bf62010-07-20 06:45:56 +00001083 if (info.delivery_failure) {
1084 kfree_skb(info.skb2);
Pablo Neira Ayusoff491a72009-02-05 23:56:36 -08001085 return -ENOBUFS;
Neil Horman70d4bf62010-07-20 06:45:56 +00001086 } else
1087 consume_skb(info.skb2);
Pablo Neira Ayusoff491a72009-02-05 23:56:36 -08001088
Linus Torvalds1da177e2005-04-16 15:20:36 -07001089 if (info.delivered) {
1090 if (info.congested && (allocation & __GFP_WAIT))
1091 yield();
1092 return 0;
1093 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001094 return -ESRCH;
1095}
Eric W. Biederman910a7e92010-05-04 17:36:46 -07001096EXPORT_SYMBOL(netlink_broadcast_filtered);
1097
1098int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
1099 u32 group, gfp_t allocation)
1100{
1101 return netlink_broadcast_filtered(ssk, skb, pid, group, allocation,
1102 NULL, NULL);
1103}
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001104EXPORT_SYMBOL(netlink_broadcast);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001105
1106struct netlink_set_err_data {
1107 struct sock *exclude_sk;
1108 u32 pid;
1109 u32 group;
1110 int code;
1111};
1112
1113static inline int do_one_set_err(struct sock *sk,
1114 struct netlink_set_err_data *p)
1115{
1116 struct netlink_sock *nlk = nlk_sk(sk);
Pablo Neira Ayuso1a503072010-03-18 14:24:42 +00001117 int ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001118
1119 if (sk == p->exclude_sk)
1120 goto out;
1121
Octavian Purdila09ad9bc2009-11-25 15:14:13 -08001122 if (!net_eq(sock_net(sk), sock_net(p->exclude_sk)))
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001123 goto out;
1124
Patrick McHardyf7fa9b12005-08-15 12:29:13 -07001125 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
1126 !test_bit(p->group - 1, nlk->groups))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001127 goto out;
1128
Pablo Neira Ayuso1a503072010-03-18 14:24:42 +00001129 if (p->code == ENOBUFS && nlk->flags & NETLINK_RECV_NO_ENOBUFS) {
1130 ret = 1;
1131 goto out;
1132 }
1133
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134 sk->sk_err = p->code;
1135 sk->sk_error_report(sk);
1136out:
Pablo Neira Ayuso1a503072010-03-18 14:24:42 +00001137 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138}
1139
Pablo Neira Ayuso4843b932009-03-03 23:37:30 -08001140/**
1141 * netlink_set_err - report error to broadcast listeners
1142 * @ssk: the kernel netlink socket, as returned by netlink_kernel_create()
1143 * @pid: the PID of a process that we want to skip (if any)
1144 * @groups: the broadcast group that will notice the error
1145 * @code: error code, must be negative (as usual in kernelspace)
Pablo Neira Ayuso1a503072010-03-18 14:24:42 +00001146 *
1147 * This function returns the number of broadcast listeners that have set the
1148 * NETLINK_RECV_NO_ENOBUFS socket option.
Pablo Neira Ayuso4843b932009-03-03 23:37:30 -08001149 */
Pablo Neira Ayuso1a503072010-03-18 14:24:42 +00001150int netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001151{
1152 struct netlink_set_err_data info;
1153 struct hlist_node *node;
1154 struct sock *sk;
Pablo Neira Ayuso1a503072010-03-18 14:24:42 +00001155 int ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001156
1157 info.exclude_sk = ssk;
1158 info.pid = pid;
1159 info.group = group;
Pablo Neira Ayuso4843b932009-03-03 23:37:30 -08001160 /* sk->sk_err wants a positive error value */
1161 info.code = -code;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001162
1163 read_lock(&nl_table_lock);
1164
1165 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
Pablo Neira Ayuso1a503072010-03-18 14:24:42 +00001166 ret += do_one_set_err(sk, &info);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167
1168 read_unlock(&nl_table_lock);
Pablo Neira Ayuso1a503072010-03-18 14:24:42 +00001169 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170}
Pablo Neira Ayusodd5b6ce2009-03-23 13:21:06 +01001171EXPORT_SYMBOL(netlink_set_err);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172
Johannes Berg84659eb2007-07-18 15:47:05 -07001173/* must be called with netlink table grabbed */
1174static void netlink_update_socket_mc(struct netlink_sock *nlk,
1175 unsigned int group,
1176 int is_new)
1177{
1178 int old, new = !!is_new, subscriptions;
1179
1180 old = test_bit(group - 1, nlk->groups);
1181 subscriptions = nlk->subscriptions - old + new;
1182 if (new)
1183 __set_bit(group - 1, nlk->groups);
1184 else
1185 __clear_bit(group - 1, nlk->groups);
1186 netlink_update_subscriptions(&nlk->sk, subscriptions);
1187 netlink_update_listeners(&nlk->sk);
1188}
1189
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001190static int netlink_setsockopt(struct socket *sock, int level, int optname,
David S. Millerb7058842009-09-30 16:12:20 -07001191 char __user *optval, unsigned int optlen)
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001192{
1193 struct sock *sk = sock->sk;
1194 struct netlink_sock *nlk = nlk_sk(sk);
Johannes Bergeb496532007-07-18 02:07:51 -07001195 unsigned int val = 0;
1196 int err;
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001197
1198 if (level != SOL_NETLINK)
1199 return -ENOPROTOOPT;
1200
1201 if (optlen >= sizeof(int) &&
Johannes Bergeb496532007-07-18 02:07:51 -07001202 get_user(val, (unsigned int __user *)optval))
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001203 return -EFAULT;
1204
1205 switch (optname) {
1206 case NETLINK_PKTINFO:
1207 if (val)
1208 nlk->flags |= NETLINK_RECV_PKTINFO;
1209 else
1210 nlk->flags &= ~NETLINK_RECV_PKTINFO;
1211 err = 0;
1212 break;
1213 case NETLINK_ADD_MEMBERSHIP:
1214 case NETLINK_DROP_MEMBERSHIP: {
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001215 if (!netlink_capable(sock, NL_NONROOT_RECV))
1216 return -EPERM;
Johannes Bergb4ff4f02007-07-18 15:46:06 -07001217 err = netlink_realloc_groups(sk);
1218 if (err)
1219 return err;
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001220 if (!val || val - 1 >= nlk->ngroups)
1221 return -EINVAL;
1222 netlink_table_grab();
Johannes Berg84659eb2007-07-18 15:47:05 -07001223 netlink_update_socket_mc(nlk, val,
1224 optname == NETLINK_ADD_MEMBERSHIP);
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001225 netlink_table_ungrab();
1226 err = 0;
1227 break;
1228 }
Pablo Neira Ayusobe0c22a2009-02-18 01:40:43 +00001229 case NETLINK_BROADCAST_ERROR:
1230 if (val)
1231 nlk->flags |= NETLINK_BROADCAST_SEND_ERROR;
1232 else
1233 nlk->flags &= ~NETLINK_BROADCAST_SEND_ERROR;
1234 err = 0;
1235 break;
Pablo Neira Ayuso38938bf2009-03-24 16:37:55 -07001236 case NETLINK_NO_ENOBUFS:
1237 if (val) {
1238 nlk->flags |= NETLINK_RECV_NO_ENOBUFS;
1239 clear_bit(0, &nlk->state);
1240 wake_up_interruptible(&nlk->wait);
1241 } else
1242 nlk->flags &= ~NETLINK_RECV_NO_ENOBUFS;
1243 err = 0;
1244 break;
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001245 default:
1246 err = -ENOPROTOOPT;
1247 }
1248 return err;
1249}
1250
1251static int netlink_getsockopt(struct socket *sock, int level, int optname,
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +09001252 char __user *optval, int __user *optlen)
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001253{
1254 struct sock *sk = sock->sk;
1255 struct netlink_sock *nlk = nlk_sk(sk);
1256 int len, val, err;
1257
1258 if (level != SOL_NETLINK)
1259 return -ENOPROTOOPT;
1260
1261 if (get_user(len, optlen))
1262 return -EFAULT;
1263 if (len < 0)
1264 return -EINVAL;
1265
1266 switch (optname) {
1267 case NETLINK_PKTINFO:
1268 if (len < sizeof(int))
1269 return -EINVAL;
1270 len = sizeof(int);
1271 val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0;
Heiko Carstensa27b58f2006-10-30 15:06:12 -08001272 if (put_user(len, optlen) ||
1273 put_user(val, optval))
1274 return -EFAULT;
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001275 err = 0;
1276 break;
Pablo Neira Ayusobe0c22a2009-02-18 01:40:43 +00001277 case NETLINK_BROADCAST_ERROR:
1278 if (len < sizeof(int))
1279 return -EINVAL;
1280 len = sizeof(int);
1281 val = nlk->flags & NETLINK_BROADCAST_SEND_ERROR ? 1 : 0;
1282 if (put_user(len, optlen) ||
1283 put_user(val, optval))
1284 return -EFAULT;
1285 err = 0;
1286 break;
Pablo Neira Ayuso38938bf2009-03-24 16:37:55 -07001287 case NETLINK_NO_ENOBUFS:
1288 if (len < sizeof(int))
1289 return -EINVAL;
1290 len = sizeof(int);
1291 val = nlk->flags & NETLINK_RECV_NO_ENOBUFS ? 1 : 0;
1292 if (put_user(len, optlen) ||
1293 put_user(val, optval))
1294 return -EFAULT;
1295 err = 0;
1296 break;
Patrick McHardy9a4595b2005-08-15 12:32:15 -07001297 default:
1298 err = -ENOPROTOOPT;
1299 }
1300 return err;
1301}
1302
1303static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
1304{
1305 struct nl_pktinfo info;
1306
1307 info.group = NETLINK_CB(skb).dst_group;
1308 put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info);
1309}
1310
Linus Torvalds1da177e2005-04-16 15:20:36 -07001311static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
1312 struct msghdr *msg, size_t len)
1313{
1314 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1315 struct sock *sk = sock->sk;
1316 struct netlink_sock *nlk = nlk_sk(sk);
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001317 struct sockaddr_nl *addr = msg->msg_name;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001318 u32 dst_pid;
Patrick McHardyd629b832005-08-14 19:27:50 -07001319 u32 dst_group;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001320 struct sk_buff *skb;
1321 int err;
1322 struct scm_cookie scm;
1323
1324 if (msg->msg_flags&MSG_OOB)
1325 return -EOPNOTSUPP;
1326
Eric W. Biedermanb47030c2010-06-13 03:31:06 +00001327 if (NULL == siocb->scm) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001328 siocb->scm = &scm;
Eric W. Biedermanb47030c2010-06-13 03:31:06 +00001329 memset(&scm, 0, sizeof(scm));
1330 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331 err = scm_send(sock, msg, siocb->scm);
1332 if (err < 0)
1333 return err;
1334
1335 if (msg->msg_namelen) {
Eric W. Biedermanb47030c2010-06-13 03:31:06 +00001336 err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001337 if (addr->nl_family != AF_NETLINK)
Eric W. Biedermanb47030c2010-06-13 03:31:06 +00001338 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001339 dst_pid = addr->nl_pid;
Patrick McHardyd629b832005-08-14 19:27:50 -07001340 dst_group = ffs(addr->nl_groups);
Eric W. Biedermanb47030c2010-06-13 03:31:06 +00001341 err = -EPERM;
Patrick McHardyd629b832005-08-14 19:27:50 -07001342 if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND))
Eric W. Biedermanb47030c2010-06-13 03:31:06 +00001343 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001344 } else {
1345 dst_pid = nlk->dst_pid;
Patrick McHardyd629b832005-08-14 19:27:50 -07001346 dst_group = nlk->dst_group;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001347 }
1348
1349 if (!nlk->pid) {
1350 err = netlink_autobind(sock);
1351 if (err)
1352 goto out;
1353 }
1354
1355 err = -EMSGSIZE;
1356 if (len > sk->sk_sndbuf - 32)
1357 goto out;
1358 err = -ENOBUFS;
Thomas Graf339bf982006-11-10 14:10:15 -08001359 skb = alloc_skb(len, GFP_KERNEL);
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001360 if (skb == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001361 goto out;
1362
1363 NETLINK_CB(skb).pid = nlk->pid;
Patrick McHardyd629b832005-08-14 19:27:50 -07001364 NETLINK_CB(skb).dst_group = dst_group;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001365 memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1366
Linus Torvalds1da177e2005-04-16 15:20:36 -07001367 err = -EFAULT;
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001368 if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001369 kfree_skb(skb);
1370 goto out;
1371 }
1372
1373 err = security_netlink_send(sk, skb);
1374 if (err) {
1375 kfree_skb(skb);
1376 goto out;
1377 }
1378
Patrick McHardyd629b832005-08-14 19:27:50 -07001379 if (dst_group) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001380 atomic_inc(&skb->users);
Patrick McHardyd629b832005-08-14 19:27:50 -07001381 netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001382 }
1383 err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT);
1384
1385out:
Eric W. Biedermanb47030c2010-06-13 03:31:06 +00001386 scm_destroy(siocb->scm);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001387 return err;
1388}
1389
1390static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
1391 struct msghdr *msg, size_t len,
1392 int flags)
1393{
1394 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1395 struct scm_cookie scm;
1396 struct sock *sk = sock->sk;
1397 struct netlink_sock *nlk = nlk_sk(sk);
1398 int noblock = flags&MSG_DONTWAIT;
1399 size_t copied;
Johannes Berg68d6ac62010-08-15 21:20:44 +00001400 struct sk_buff *skb, *data_skb;
Andrey Vaginb44d2112011-02-21 02:40:47 +00001401 int err, ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001402
1403 if (flags&MSG_OOB)
1404 return -EOPNOTSUPP;
1405
1406 copied = 0;
1407
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001408 skb = skb_recv_datagram(sk, flags, noblock, &err);
1409 if (skb == NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001410 goto out;
1411
Johannes Berg68d6ac62010-08-15 21:20:44 +00001412 data_skb = skb;
1413
Johannes Berg1dacc762009-07-01 11:26:02 +00001414#ifdef CONFIG_COMPAT_NETLINK_MESSAGES
1415 if (unlikely(skb_shinfo(skb)->frag_list)) {
Johannes Berg1dacc762009-07-01 11:26:02 +00001416 /*
Johannes Berg68d6ac62010-08-15 21:20:44 +00001417 * If this skb has a frag_list, then here that means that we
1418 * will have to use the frag_list skb's data for compat tasks
1419 * and the regular skb's data for normal (non-compat) tasks.
Johannes Berg1dacc762009-07-01 11:26:02 +00001420 *
Johannes Berg68d6ac62010-08-15 21:20:44 +00001421 * If we need to send the compat skb, assign it to the
1422 * 'data_skb' variable so that it will be used below for data
1423 * copying. We keep 'skb' for everything else, including
1424 * freeing both later.
Johannes Berg1dacc762009-07-01 11:26:02 +00001425 */
Johannes Berg68d6ac62010-08-15 21:20:44 +00001426 if (flags & MSG_CMSG_COMPAT)
1427 data_skb = skb_shinfo(skb)->frag_list;
Johannes Berg1dacc762009-07-01 11:26:02 +00001428 }
1429#endif
1430
Linus Torvalds1da177e2005-04-16 15:20:36 -07001431 msg->msg_namelen = 0;
1432
Johannes Berg68d6ac62010-08-15 21:20:44 +00001433 copied = data_skb->len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001434 if (len < copied) {
1435 msg->msg_flags |= MSG_TRUNC;
1436 copied = len;
1437 }
1438
Johannes Berg68d6ac62010-08-15 21:20:44 +00001439 skb_reset_transport_header(data_skb);
1440 err = skb_copy_datagram_iovec(data_skb, 0, msg->msg_iov, copied);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001441
1442 if (msg->msg_name) {
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001443 struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001444 addr->nl_family = AF_NETLINK;
1445 addr->nl_pad = 0;
1446 addr->nl_pid = NETLINK_CB(skb).pid;
Patrick McHardyd629b832005-08-14 19:27:50 -07001447 addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001448 msg->msg_namelen = sizeof(*addr);
1449 }
1450
Patrick McHardycc9a06c2006-03-12 20:34:27 -08001451 if (nlk->flags & NETLINK_RECV_PKTINFO)
1452 netlink_cmsg_recv_pktinfo(msg, skb);
1453
Linus Torvalds1da177e2005-04-16 15:20:36 -07001454 if (NULL == siocb->scm) {
1455 memset(&scm, 0, sizeof(scm));
1456 siocb->scm = &scm;
1457 }
1458 siocb->scm->creds = *NETLINK_CREDS(skb);
Patrick McHardy188ccb52007-05-03 03:27:01 -07001459 if (flags & MSG_TRUNC)
Johannes Berg68d6ac62010-08-15 21:20:44 +00001460 copied = data_skb->len;
David S. Millerdaa37662010-08-15 23:21:50 -07001461
Linus Torvalds1da177e2005-04-16 15:20:36 -07001462 skb_free_datagram(sk, skb);
1463
Andrey Vaginb44d2112011-02-21 02:40:47 +00001464 if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) {
1465 ret = netlink_dump(sk);
1466 if (ret) {
1467 sk->sk_err = ret;
1468 sk->sk_error_report(sk);
1469 }
1470 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001471
1472 scm_recv(sock, msg, siocb->scm, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001473out:
1474 netlink_rcv_wake(sk);
1475 return err ? : copied;
1476}
1477
1478static void netlink_data_ready(struct sock *sk, int len)
1479{
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -07001480 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001481}
1482
1483/*
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +09001484 * We export these functions to other modules. They provide a
Linus Torvalds1da177e2005-04-16 15:20:36 -07001485 * complete set of kernel non-blocking support for message
1486 * queueing.
1487 */
1488
1489struct sock *
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001490netlink_kernel_create(struct net *net, int unit, unsigned int groups,
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -07001491 void (*input)(struct sk_buff *skb),
Patrick McHardyaf65bdf2007-04-20 14:14:21 -07001492 struct mutex *cb_mutex, struct module *module)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001493{
1494 struct socket *sock;
1495 struct sock *sk;
Patrick McHardy77247bb2005-08-14 19:27:13 -07001496 struct netlink_sock *nlk;
Eric Dumazet5c398dc2010-10-24 04:27:10 +00001497 struct listeners *listeners = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001498
Akinobu Mitafab2caf2006-08-29 02:15:24 -07001499 BUG_ON(!nl_table);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001500
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001501 if (unit < 0 || unit >= MAX_LINKS)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001502 return NULL;
1503
1504 if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
1505 return NULL;
1506
Pavel Emelyanov23fe1862008-01-30 19:31:06 -08001507 /*
1508 * We have to just have a reference on the net from sk, but don't
1509 * get_net it. Besides, we cannot get and then put the net here.
1510 * So we create one inside init_net and the move it to net.
1511 */
1512
1513 if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0)
1514 goto out_sock_release_nosk;
1515
1516 sk = sock->sk;
Denis V. Lunevedf02082008-02-29 11:18:32 -08001517 sk_change_net(sk, net);
Harald Welte4fdb3bb2005-08-09 19:40:55 -07001518
Patrick McHardy4277a082006-03-20 18:52:01 -08001519 if (groups < 32)
1520 groups = 32;
1521
Eric Dumazet5c398dc2010-10-24 04:27:10 +00001522 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
Patrick McHardy4277a082006-03-20 18:52:01 -08001523 if (!listeners)
1524 goto out_sock_release;
1525
Linus Torvalds1da177e2005-04-16 15:20:36 -07001526 sk->sk_data_ready = netlink_data_ready;
1527 if (input)
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -07001528 nlk_sk(sk)->netlink_rcv = input;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001529
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001530 if (netlink_insert(sk, net, 0))
Patrick McHardy77247bb2005-08-14 19:27:13 -07001531 goto out_sock_release;
1532
1533 nlk = nlk_sk(sk);
1534 nlk->flags |= NETLINK_KERNEL_SOCKET;
1535
1536 netlink_table_grab();
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001537 if (!nl_table[unit].registered) {
1538 nl_table[unit].groups = groups;
Eric Dumazet5c398dc2010-10-24 04:27:10 +00001539 rcu_assign_pointer(nl_table[unit].listeners, listeners);
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001540 nl_table[unit].cb_mutex = cb_mutex;
1541 nl_table[unit].module = module;
1542 nl_table[unit].registered = 1;
Jesper Juhlf937f1f462007-10-15 01:39:12 -07001543 } else {
1544 kfree(listeners);
Denis V. Lunev869e58f2008-01-18 23:53:31 -08001545 nl_table[unit].registered++;
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001546 }
Patrick McHardy77247bb2005-08-14 19:27:13 -07001547 netlink_table_ungrab();
Harald Welte4fdb3bb2005-08-09 19:40:55 -07001548 return sk;
1549
Harald Welte4fdb3bb2005-08-09 19:40:55 -07001550out_sock_release:
Patrick McHardy4277a082006-03-20 18:52:01 -08001551 kfree(listeners);
Denis V. Lunev9dfbec12008-02-29 11:17:56 -08001552 netlink_kernel_release(sk);
Pavel Emelyanov23fe1862008-01-30 19:31:06 -08001553 return NULL;
1554
1555out_sock_release_nosk:
Harald Welte4fdb3bb2005-08-09 19:40:55 -07001556 sock_release(sock);
Patrick McHardy77247bb2005-08-14 19:27:13 -07001557 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001558}
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001559EXPORT_SYMBOL(netlink_kernel_create);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001560
Denis V. Lunevb7c6ba62008-01-28 14:41:19 -08001561
1562void
1563netlink_kernel_release(struct sock *sk)
1564{
Denis V. Lunevedf02082008-02-29 11:18:32 -08001565 sk_release_kernel(sk);
Denis V. Lunevb7c6ba62008-01-28 14:41:19 -08001566}
1567EXPORT_SYMBOL(netlink_kernel_release);
1568
Johannes Bergd136f1b2009-09-12 03:03:15 +00001569int __netlink_change_ngroups(struct sock *sk, unsigned int groups)
Johannes Bergb4ff4f02007-07-18 15:46:06 -07001570{
Eric Dumazet5c398dc2010-10-24 04:27:10 +00001571 struct listeners *new, *old;
Johannes Bergb4ff4f02007-07-18 15:46:06 -07001572 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
Johannes Bergb4ff4f02007-07-18 15:46:06 -07001573
1574 if (groups < 32)
1575 groups = 32;
1576
Johannes Bergb4ff4f02007-07-18 15:46:06 -07001577 if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) {
Eric Dumazet5c398dc2010-10-24 04:27:10 +00001578 new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC);
1579 if (!new)
Johannes Bergd136f1b2009-09-12 03:03:15 +00001580 return -ENOMEM;
Eric Dumazet5c398dc2010-10-24 04:27:10 +00001581 old = rcu_dereference_raw(tbl->listeners);
1582 memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups));
1583 rcu_assign_pointer(tbl->listeners, new);
1584
Lai Jiangshan37b6b932011-03-15 18:01:42 +08001585 kfree_rcu(old, rcu);
Johannes Bergb4ff4f02007-07-18 15:46:06 -07001586 }
1587 tbl->groups = groups;
1588
Johannes Bergd136f1b2009-09-12 03:03:15 +00001589 return 0;
1590}
1591
1592/**
1593 * netlink_change_ngroups - change number of multicast groups
1594 *
1595 * This changes the number of multicast groups that are available
1596 * on a certain netlink family. Note that it is not possible to
1597 * change the number of groups to below 32. Also note that it does
1598 * not implicitly call netlink_clear_multicast_users() when the
1599 * number of groups is reduced.
1600 *
1601 * @sk: The kernel netlink socket, as returned by netlink_kernel_create().
1602 * @groups: The new number of groups.
1603 */
1604int netlink_change_ngroups(struct sock *sk, unsigned int groups)
1605{
1606 int err;
1607
1608 netlink_table_grab();
1609 err = __netlink_change_ngroups(sk, groups);
Johannes Bergb4ff4f02007-07-18 15:46:06 -07001610 netlink_table_ungrab();
Johannes Bergd136f1b2009-09-12 03:03:15 +00001611
Johannes Bergb4ff4f02007-07-18 15:46:06 -07001612 return err;
1613}
Johannes Bergb4ff4f02007-07-18 15:46:06 -07001614
Johannes Bergb8273572009-09-24 15:44:05 -07001615void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
1616{
1617 struct sock *sk;
1618 struct hlist_node *node;
1619 struct netlink_table *tbl = &nl_table[ksk->sk_protocol];
1620
1621 sk_for_each_bound(sk, node, &tbl->mc_list)
1622 netlink_update_socket_mc(nlk_sk(sk), group, 0);
1623}
1624
Johannes Berg84659eb2007-07-18 15:47:05 -07001625/**
1626 * netlink_clear_multicast_users - kick off multicast listeners
1627 *
1628 * This function removes all listeners from the given group.
1629 * @ksk: The kernel netlink socket, as returned by
1630 * netlink_kernel_create().
1631 * @group: The multicast group to clear.
1632 */
1633void netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
1634{
Johannes Berg84659eb2007-07-18 15:47:05 -07001635 netlink_table_grab();
Johannes Bergb8273572009-09-24 15:44:05 -07001636 __netlink_clear_multicast_users(ksk, group);
Johannes Berg84659eb2007-07-18 15:47:05 -07001637 netlink_table_ungrab();
1638}
Johannes Berg84659eb2007-07-18 15:47:05 -07001639
Linus Torvalds1da177e2005-04-16 15:20:36 -07001640void netlink_set_nonroot(int protocol, unsigned int flags)
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +09001641{
1642 if ((unsigned int)protocol < MAX_LINKS)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001643 nl_table[protocol].nl_nonroot = flags;
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +09001644}
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001645EXPORT_SYMBOL(netlink_set_nonroot);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001646
1647static void netlink_destroy_callback(struct netlink_callback *cb)
1648{
Wei Yongjun91744f62009-02-25 00:34:41 +00001649 kfree_skb(cb->skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001650 kfree(cb);
1651}
1652
1653/*
1654 * It looks a bit ugly.
1655 * It would be better to create kernel thread.
1656 */
1657
1658static int netlink_dump(struct sock *sk)
1659{
1660 struct netlink_sock *nlk = nlk_sk(sk);
1661 struct netlink_callback *cb;
1662 struct sk_buff *skb;
1663 struct nlmsghdr *nlh;
Thomas Grafbf8b79e2006-08-04 23:03:29 -07001664 int len, err = -ENOBUFS;
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +09001665
Linus Torvalds1da177e2005-04-16 15:20:36 -07001666 skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL);
1667 if (!skb)
Thomas Grafbf8b79e2006-08-04 23:03:29 -07001668 goto errout;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001669
Patrick McHardyaf65bdf2007-04-20 14:14:21 -07001670 mutex_lock(nlk->cb_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001671
1672 cb = nlk->cb;
1673 if (cb == NULL) {
Thomas Grafbf8b79e2006-08-04 23:03:29 -07001674 err = -EINVAL;
1675 goto errout_skb;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001676 }
1677
1678 len = cb->dump(skb, cb);
1679
1680 if (len > 0) {
Patrick McHardyaf65bdf2007-04-20 14:14:21 -07001681 mutex_unlock(nlk->cb_mutex);
Stephen Hemmingerb1153f22008-03-21 15:46:12 -07001682
1683 if (sk_filter(sk, skb))
1684 kfree_skb(skb);
1685 else {
1686 skb_queue_tail(&sk->sk_receive_queue, skb);
1687 sk->sk_data_ready(sk, skb->len);
1688 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001689 return 0;
1690 }
1691
Thomas Grafbf8b79e2006-08-04 23:03:29 -07001692 nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI);
1693 if (!nlh)
1694 goto errout_skb;
1695
1696 memcpy(nlmsg_data(nlh), &len, sizeof(len));
1697
Stephen Hemmingerb1153f22008-03-21 15:46:12 -07001698 if (sk_filter(sk, skb))
1699 kfree_skb(skb);
1700 else {
1701 skb_queue_tail(&sk->sk_receive_queue, skb);
1702 sk->sk_data_ready(sk, skb->len);
1703 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001704
Thomas Grafa8f74b22005-11-10 02:25:52 +01001705 if (cb->done)
1706 cb->done(cb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001707 nlk->cb = NULL;
Patrick McHardyaf65bdf2007-04-20 14:14:21 -07001708 mutex_unlock(nlk->cb_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001709
1710 netlink_destroy_callback(cb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001711 return 0;
Thomas Graf17977542005-06-18 22:53:48 -07001712
Thomas Grafbf8b79e2006-08-04 23:03:29 -07001713errout_skb:
Patrick McHardyaf65bdf2007-04-20 14:14:21 -07001714 mutex_unlock(nlk->cb_mutex);
Thomas Grafbf8b79e2006-08-04 23:03:29 -07001715 kfree_skb(skb);
1716errout:
1717 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001718}
1719
1720int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
Patrick McHardy3a6c2b42009-08-25 16:07:40 +02001721 const struct nlmsghdr *nlh,
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001722 int (*dump)(struct sk_buff *skb,
1723 struct netlink_callback *),
1724 int (*done)(struct netlink_callback *))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001725{
1726 struct netlink_callback *cb;
1727 struct sock *sk;
1728 struct netlink_sock *nlk;
Andrey Vaginb44d2112011-02-21 02:40:47 +00001729 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001730
Panagiotis Issaris0da974f2006-07-21 14:51:30 -07001731 cb = kzalloc(sizeof(*cb), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001732 if (cb == NULL)
1733 return -ENOBUFS;
1734
Linus Torvalds1da177e2005-04-16 15:20:36 -07001735 cb->dump = dump;
1736 cb->done = done;
1737 cb->nlh = nlh;
1738 atomic_inc(&skb->users);
1739 cb->skb = skb;
1740
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +09001741 sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001742 if (sk == NULL) {
1743 netlink_destroy_callback(cb);
1744 return -ECONNREFUSED;
1745 }
1746 nlk = nlk_sk(sk);
Herbert Xu3f660d62007-05-03 03:17:14 -07001747 /* A dump is in progress... */
Patrick McHardyaf65bdf2007-04-20 14:14:21 -07001748 mutex_lock(nlk->cb_mutex);
Herbert Xu3f660d62007-05-03 03:17:14 -07001749 if (nlk->cb) {
Patrick McHardyaf65bdf2007-04-20 14:14:21 -07001750 mutex_unlock(nlk->cb_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001751 netlink_destroy_callback(cb);
1752 sock_put(sk);
1753 return -EBUSY;
1754 }
1755 nlk->cb = cb;
Patrick McHardyaf65bdf2007-04-20 14:14:21 -07001756 mutex_unlock(nlk->cb_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001757
Andrey Vaginb44d2112011-02-21 02:40:47 +00001758 ret = netlink_dump(sk);
1759
Linus Torvalds1da177e2005-04-16 15:20:36 -07001760 sock_put(sk);
Denis V. Lunev5c582982007-10-23 20:29:25 -07001761
Andrey Vaginb44d2112011-02-21 02:40:47 +00001762 if (ret)
1763 return ret;
1764
Denis V. Lunev5c582982007-10-23 20:29:25 -07001765 /* We successfully started a dump, by returning -EINTR we
1766 * signal not to send ACK even if it was requested.
1767 */
1768 return -EINTR;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001769}
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001770EXPORT_SYMBOL(netlink_dump_start);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001771
1772void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
1773{
1774 struct sk_buff *skb;
1775 struct nlmsghdr *rep;
1776 struct nlmsgerr *errmsg;
Thomas Graf339bf982006-11-10 14:10:15 -08001777 size_t payload = sizeof(*errmsg);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001778
Thomas Graf339bf982006-11-10 14:10:15 -08001779 /* error messages get the original request appened */
1780 if (err)
1781 payload += nlmsg_len(nlh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001782
Thomas Graf339bf982006-11-10 14:10:15 -08001783 skb = nlmsg_new(payload, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001784 if (!skb) {
1785 struct sock *sk;
1786
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +09001787 sk = netlink_lookup(sock_net(in_skb->sk),
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001788 in_skb->sk->sk_protocol,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001789 NETLINK_CB(in_skb).pid);
1790 if (sk) {
1791 sk->sk_err = ENOBUFS;
1792 sk->sk_error_report(sk);
1793 sock_put(sk);
1794 }
1795 return;
1796 }
1797
1798 rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
John Fastabend5dba93a2009-09-25 13:11:44 +00001799 NLMSG_ERROR, payload, 0);
Thomas Grafbf8b79e2006-08-04 23:03:29 -07001800 errmsg = nlmsg_data(rep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001801 errmsg->error = err;
Thomas Grafbf8b79e2006-08-04 23:03:29 -07001802 memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001803 netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
1804}
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001805EXPORT_SYMBOL(netlink_ack);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001806
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -07001807int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
Thomas Graf1d00a4e2007-03-22 23:30:12 -07001808 struct nlmsghdr *))
Thomas Graf82ace472005-11-10 02:25:53 +01001809{
Thomas Graf82ace472005-11-10 02:25:53 +01001810 struct nlmsghdr *nlh;
1811 int err;
1812
1813 while (skb->len >= nlmsg_total_size(0)) {
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -07001814 int msglen;
1815
Arnaldo Carvalho de Melob529ccf2007-04-25 19:08:35 -07001816 nlh = nlmsg_hdr(skb);
Thomas Grafd35b6852007-03-22 23:28:46 -07001817 err = 0;
Thomas Graf82ace472005-11-10 02:25:53 +01001818
Martin Murrayad8e4b72006-01-10 13:02:29 -08001819 if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
Thomas Graf82ace472005-11-10 02:25:53 +01001820 return 0;
1821
Thomas Grafd35b6852007-03-22 23:28:46 -07001822 /* Only requests are handled by the kernel */
1823 if (!(nlh->nlmsg_flags & NLM_F_REQUEST))
Denis V. Lunev5c582982007-10-23 20:29:25 -07001824 goto ack;
Thomas Grafd35b6852007-03-22 23:28:46 -07001825
Thomas Graf45e7ae72007-03-22 23:29:10 -07001826 /* Skip control messages */
1827 if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
Denis V. Lunev5c582982007-10-23 20:29:25 -07001828 goto ack;
Thomas Graf45e7ae72007-03-22 23:29:10 -07001829
Thomas Graf1d00a4e2007-03-22 23:30:12 -07001830 err = cb(skb, nlh);
Denis V. Lunev5c582982007-10-23 20:29:25 -07001831 if (err == -EINTR)
1832 goto skip;
1833
1834ack:
Thomas Grafd35b6852007-03-22 23:28:46 -07001835 if (nlh->nlmsg_flags & NLM_F_ACK || err)
Thomas Graf82ace472005-11-10 02:25:53 +01001836 netlink_ack(skb, nlh, err);
Thomas Graf82ace472005-11-10 02:25:53 +01001837
Denis V. Lunev5c582982007-10-23 20:29:25 -07001838skip:
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001839 msglen = NLMSG_ALIGN(nlh->nlmsg_len);
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -07001840 if (msglen > skb->len)
1841 msglen = skb->len;
1842 skb_pull(skb, msglen);
Thomas Graf82ace472005-11-10 02:25:53 +01001843 }
1844
1845 return 0;
1846}
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001847EXPORT_SYMBOL(netlink_rcv_skb);
Thomas Graf82ace472005-11-10 02:25:53 +01001848
1849/**
Thomas Grafd387f6a2006-08-15 00:31:06 -07001850 * nlmsg_notify - send a notification netlink message
1851 * @sk: netlink socket to use
1852 * @skb: notification message
1853 * @pid: destination netlink pid for reports or 0
1854 * @group: destination multicast group or 0
1855 * @report: 1 to report back, 0 to disable
1856 * @flags: allocation flags
1857 */
1858int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid,
1859 unsigned int group, int report, gfp_t flags)
1860{
1861 int err = 0;
1862
1863 if (group) {
1864 int exclude_pid = 0;
1865
1866 if (report) {
1867 atomic_inc(&skb->users);
1868 exclude_pid = pid;
1869 }
1870
Pablo Neira Ayuso1ce85fe2009-02-24 23:18:28 -08001871 /* errors reported via destination sk->sk_err, but propagate
1872 * delivery errors if NETLINK_BROADCAST_ERROR flag is set */
1873 err = nlmsg_multicast(sk, skb, exclude_pid, group, flags);
Thomas Grafd387f6a2006-08-15 00:31:06 -07001874 }
1875
Pablo Neira Ayuso1ce85fe2009-02-24 23:18:28 -08001876 if (report) {
1877 int err2;
1878
1879 err2 = nlmsg_unicast(sk, skb, pid);
1880 if (!err || err == -ESRCH)
1881 err = err2;
1882 }
Thomas Grafd387f6a2006-08-15 00:31:06 -07001883
1884 return err;
1885}
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001886EXPORT_SYMBOL(nlmsg_notify);
Thomas Grafd387f6a2006-08-15 00:31:06 -07001887
Linus Torvalds1da177e2005-04-16 15:20:36 -07001888#ifdef CONFIG_PROC_FS
1889struct nl_seq_iter {
Denis V. Luneve372c412007-11-19 22:31:54 -08001890 struct seq_net_private p;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001891 int link;
1892 int hash_idx;
1893};
1894
1895static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos)
1896{
1897 struct nl_seq_iter *iter = seq->private;
1898 int i, j;
1899 struct sock *s;
1900 struct hlist_node *node;
1901 loff_t off = 0;
1902
Patrick McHardy6ac552f2007-12-04 00:19:38 -08001903 for (i = 0; i < MAX_LINKS; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001904 struct nl_pid_hash *hash = &nl_table[i].hash;
1905
1906 for (j = 0; j <= hash->mask; j++) {
1907 sk_for_each(s, node, &hash->table[j]) {
YOSHIFUJI Hideaki12188542008-03-26 02:36:06 +09001908 if (sock_net(s) != seq_file_net(seq))
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001909 continue;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001910 if (off == pos) {
1911 iter->link = i;
1912 iter->hash_idx = j;
1913 return s;
1914 }
1915 ++off;
1916 }
1917 }
1918 }
1919 return NULL;
1920}
1921
1922static void *netlink_seq_start(struct seq_file *seq, loff_t *pos)
Eric Dumazet9a429c42008-01-01 21:58:02 -08001923 __acquires(nl_table_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001924{
1925 read_lock(&nl_table_lock);
1926 return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN;
1927}
1928
1929static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1930{
1931 struct sock *s;
1932 struct nl_seq_iter *iter;
1933 int i, j;
1934
1935 ++*pos;
1936
1937 if (v == SEQ_START_TOKEN)
1938 return netlink_seq_socket_idx(seq, 0);
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +09001939
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001940 iter = seq->private;
1941 s = v;
1942 do {
1943 s = sk_next(s);
YOSHIFUJI Hideaki12188542008-03-26 02:36:06 +09001944 } while (s && sock_net(s) != seq_file_net(seq));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001945 if (s)
1946 return s;
1947
Linus Torvalds1da177e2005-04-16 15:20:36 -07001948 i = iter->link;
1949 j = iter->hash_idx + 1;
1950
1951 do {
1952 struct nl_pid_hash *hash = &nl_table[i].hash;
1953
1954 for (; j <= hash->mask; j++) {
1955 s = sk_head(&hash->table[j]);
YOSHIFUJI Hideaki12188542008-03-26 02:36:06 +09001956 while (s && sock_net(s) != seq_file_net(seq))
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02001957 s = sk_next(s);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001958 if (s) {
1959 iter->link = i;
1960 iter->hash_idx = j;
1961 return s;
1962 }
1963 }
1964
1965 j = 0;
1966 } while (++i < MAX_LINKS);
1967
1968 return NULL;
1969}
1970
1971static void netlink_seq_stop(struct seq_file *seq, void *v)
Eric Dumazet9a429c42008-01-01 21:58:02 -08001972 __releases(nl_table_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001973{
1974 read_unlock(&nl_table_lock);
1975}
1976
1977
1978static int netlink_seq_show(struct seq_file *seq, void *v)
1979{
1980 if (v == SEQ_START_TOKEN)
1981 seq_puts(seq,
1982 "sk Eth Pid Groups "
Masatake YAMATOcf0aa4e2010-02-27 19:45:37 +00001983 "Rmem Wmem Dump Locks Drops Inode\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001984 else {
1985 struct sock *s = v;
1986 struct netlink_sock *nlk = nlk_sk(s);
1987
Dan Rosenberg71338aa2011-05-23 12:17:35 +00001988 seq_printf(seq, "%pK %-3d %-6d %08x %-8d %-8d %pK %-8d %-8d %-8lu\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001989 s,
1990 s->sk_protocol,
1991 nlk->pid,
Patrick McHardy513c2502005-09-06 15:43:59 -07001992 nlk->groups ? (u32)nlk->groups[0] : 0,
Eric Dumazet31e6d362009-06-17 19:05:41 -07001993 sk_rmem_alloc_get(s),
1994 sk_wmem_alloc_get(s),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001995 nlk->cb,
Pablo Neira Ayuso38938bf2009-03-24 16:37:55 -07001996 atomic_read(&s->sk_refcnt),
Masatake YAMATOcf0aa4e2010-02-27 19:45:37 +00001997 atomic_read(&s->sk_drops),
1998 sock_i_ino(s)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001999 );
2000
2001 }
2002 return 0;
2003}
2004
Philippe De Muyter56b3d972007-07-10 23:07:31 -07002005static const struct seq_operations netlink_seq_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002006 .start = netlink_seq_start,
2007 .next = netlink_seq_next,
2008 .stop = netlink_seq_stop,
2009 .show = netlink_seq_show,
2010};
2011
2012
2013static int netlink_seq_open(struct inode *inode, struct file *file)
2014{
Denis V. Luneve372c412007-11-19 22:31:54 -08002015 return seq_open_net(inode, file, &netlink_seq_ops,
2016 sizeof(struct nl_seq_iter));
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02002017}
2018
Arjan van de Venda7071d2007-02-12 00:55:36 -08002019static const struct file_operations netlink_seq_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002020 .owner = THIS_MODULE,
2021 .open = netlink_seq_open,
2022 .read = seq_read,
2023 .llseek = seq_lseek,
Denis V. Luneve372c412007-11-19 22:31:54 -08002024 .release = seq_release_net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002025};
2026
2027#endif
2028
2029int netlink_register_notifier(struct notifier_block *nb)
2030{
Alan Sterne041c682006-03-27 01:16:30 -08002031 return atomic_notifier_chain_register(&netlink_chain, nb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002032}
Patrick McHardy6ac552f2007-12-04 00:19:38 -08002033EXPORT_SYMBOL(netlink_register_notifier);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002034
2035int netlink_unregister_notifier(struct notifier_block *nb)
2036{
Alan Sterne041c682006-03-27 01:16:30 -08002037 return atomic_notifier_chain_unregister(&netlink_chain, nb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002038}
Patrick McHardy6ac552f2007-12-04 00:19:38 -08002039EXPORT_SYMBOL(netlink_unregister_notifier);
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +09002040
Eric Dumazet90ddc4f2005-12-22 12:49:22 -08002041static const struct proto_ops netlink_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002042 .family = PF_NETLINK,
2043 .owner = THIS_MODULE,
2044 .release = netlink_release,
2045 .bind = netlink_bind,
2046 .connect = netlink_connect,
2047 .socketpair = sock_no_socketpair,
2048 .accept = sock_no_accept,
2049 .getname = netlink_getname,
2050 .poll = datagram_poll,
2051 .ioctl = sock_no_ioctl,
2052 .listen = sock_no_listen,
2053 .shutdown = sock_no_shutdown,
Patrick McHardy9a4595b2005-08-15 12:32:15 -07002054 .setsockopt = netlink_setsockopt,
2055 .getsockopt = netlink_getsockopt,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002056 .sendmsg = netlink_sendmsg,
2057 .recvmsg = netlink_recvmsg,
2058 .mmap = sock_no_mmap,
2059 .sendpage = sock_no_sendpage,
2060};
2061
Stephen Hemmingerec1b4cf2009-10-05 05:58:39 +00002062static const struct net_proto_family netlink_family_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002063 .family = PF_NETLINK,
2064 .create = netlink_create,
2065 .owner = THIS_MODULE, /* for consistency 8) */
2066};
2067
Pavel Emelyanov46650792007-10-08 20:38:39 -07002068static int __net_init netlink_net_init(struct net *net)
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02002069{
2070#ifdef CONFIG_PROC_FS
2071 if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops))
2072 return -ENOMEM;
2073#endif
2074 return 0;
2075}
2076
Pavel Emelyanov46650792007-10-08 20:38:39 -07002077static void __net_exit netlink_net_exit(struct net *net)
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02002078{
2079#ifdef CONFIG_PROC_FS
2080 proc_net_remove(net, "netlink");
2081#endif
2082}
2083
David S. Millerb963ea82010-08-30 19:08:01 -07002084static void __init netlink_add_usersock_entry(void)
2085{
Eric Dumazet5c398dc2010-10-24 04:27:10 +00002086 struct listeners *listeners;
David S. Millerb963ea82010-08-30 19:08:01 -07002087 int groups = 32;
2088
Eric Dumazet5c398dc2010-10-24 04:27:10 +00002089 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
David S. Millerb963ea82010-08-30 19:08:01 -07002090 if (!listeners)
Eric Dumazet5c398dc2010-10-24 04:27:10 +00002091 panic("netlink_add_usersock_entry: Cannot allocate listeners\n");
David S. Millerb963ea82010-08-30 19:08:01 -07002092
2093 netlink_table_grab();
2094
2095 nl_table[NETLINK_USERSOCK].groups = groups;
Eric Dumazet5c398dc2010-10-24 04:27:10 +00002096 rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners);
David S. Millerb963ea82010-08-30 19:08:01 -07002097 nl_table[NETLINK_USERSOCK].module = THIS_MODULE;
2098 nl_table[NETLINK_USERSOCK].registered = 1;
2099
2100 netlink_table_ungrab();
2101}
2102
Denis V. Lunev022cbae2007-11-13 03:23:50 -08002103static struct pernet_operations __net_initdata netlink_net_ops = {
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02002104 .init = netlink_net_init,
2105 .exit = netlink_net_exit,
2106};
2107
Linus Torvalds1da177e2005-04-16 15:20:36 -07002108static int __init netlink_proto_init(void)
2109{
2110 struct sk_buff *dummy_skb;
2111 int i;
Denis Cheng26ff5dd2007-09-16 16:36:02 -07002112 unsigned long limit;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002113 unsigned int order;
2114 int err = proto_register(&netlink_proto, 0);
2115
2116 if (err != 0)
2117 goto out;
2118
YOSHIFUJI Hideakief047f52006-09-01 00:29:06 -07002119 BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002120
Panagiotis Issaris0da974f2006-07-21 14:51:30 -07002121 nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);
Akinobu Mitafab2caf2006-08-29 02:15:24 -07002122 if (!nl_table)
2123 goto panic;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002124
Jan Beulich44813742009-09-21 17:03:05 -07002125 if (totalram_pages >= (128 * 1024))
2126 limit = totalram_pages >> (21 - PAGE_SHIFT);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002127 else
Jan Beulich44813742009-09-21 17:03:05 -07002128 limit = totalram_pages >> (23 - PAGE_SHIFT);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002129
Denis Cheng26ff5dd2007-09-16 16:36:02 -07002130 order = get_bitmask_order(limit) - 1 + PAGE_SHIFT;
2131 limit = (1UL << order) / sizeof(struct hlist_head);
2132 order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002133
2134 for (i = 0; i < MAX_LINKS; i++) {
2135 struct nl_pid_hash *hash = &nl_table[i].hash;
2136
Eric Dumazetea729122007-12-11 02:09:47 -08002137 hash->table = nl_pid_hash_zalloc(1 * sizeof(*hash->table));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002138 if (!hash->table) {
2139 while (i-- > 0)
2140 nl_pid_hash_free(nl_table[i].hash.table,
2141 1 * sizeof(*hash->table));
2142 kfree(nl_table);
Akinobu Mitafab2caf2006-08-29 02:15:24 -07002143 goto panic;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002144 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002145 hash->max_shift = order;
2146 hash->shift = 0;
2147 hash->mask = 0;
2148 hash->rehash_time = jiffies;
2149 }
2150
David S. Millerb963ea82010-08-30 19:08:01 -07002151 netlink_add_usersock_entry();
2152
Linus Torvalds1da177e2005-04-16 15:20:36 -07002153 sock_register(&netlink_family_ops);
Eric W. Biedermanb4b51022007-09-12 13:05:38 +02002154 register_pernet_subsys(&netlink_net_ops);
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +09002155 /* The netlink device handler may be needed early. */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002156 rtnetlink_init();
2157out:
2158 return err;
Akinobu Mitafab2caf2006-08-29 02:15:24 -07002159panic:
2160 panic("netlink_init: Cannot allocate nl_table\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002161}
2162
Linus Torvalds1da177e2005-04-16 15:20:36 -07002163core_initcall(netlink_proto_init);