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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * NETLINK Kernel-user communication protocol. | |
3 | * | |
113aa838 | 4 | * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk> |
1da177e4 LT |
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. | |
746fac4d | 11 | * |
1da177e4 LT |
12 | * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith |
13 | * added netlink_proto_exit | |
14 | * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br> | |
15 | * use nlk_sk, as sk->protinfo is on a diet 8) | |
4fdb3bb7 HW |
16 | * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org> |
17 | * - inc module use count of module that owns | |
18 | * the kernel socket in case userspace opens | |
19 | * socket of same protocol | |
20 | * - remove all module support, since netlink is | |
21 | * mandatory if CONFIG_NET=y these days | |
1da177e4 LT |
22 | */ |
23 | ||
1da177e4 LT |
24 | #include <linux/module.h> |
25 | ||
4fc268d2 | 26 | #include <linux/capability.h> |
1da177e4 LT |
27 | #include <linux/kernel.h> |
28 | #include <linux/init.h> | |
1da177e4 LT |
29 | #include <linux/signal.h> |
30 | #include <linux/sched.h> | |
31 | #include <linux/errno.h> | |
32 | #include <linux/string.h> | |
33 | #include <linux/stat.h> | |
34 | #include <linux/socket.h> | |
35 | #include <linux/un.h> | |
36 | #include <linux/fcntl.h> | |
37 | #include <linux/termios.h> | |
38 | #include <linux/sockios.h> | |
39 | #include <linux/net.h> | |
40 | #include <linux/fs.h> | |
41 | #include <linux/slab.h> | |
42 | #include <asm/uaccess.h> | |
43 | #include <linux/skbuff.h> | |
44 | #include <linux/netdevice.h> | |
45 | #include <linux/rtnetlink.h> | |
46 | #include <linux/proc_fs.h> | |
47 | #include <linux/seq_file.h> | |
1da177e4 LT |
48 | #include <linux/notifier.h> |
49 | #include <linux/security.h> | |
50 | #include <linux/jhash.h> | |
51 | #include <linux/jiffies.h> | |
52 | #include <linux/random.h> | |
53 | #include <linux/bitops.h> | |
54 | #include <linux/mm.h> | |
55 | #include <linux/types.h> | |
54e0f520 | 56 | #include <linux/audit.h> |
af65bdfc | 57 | #include <linux/mutex.h> |
54e0f520 | 58 | |
457c4cbc | 59 | #include <net/net_namespace.h> |
1da177e4 LT |
60 | #include <net/sock.h> |
61 | #include <net/scm.h> | |
82ace47a | 62 | #include <net/netlink.h> |
1da177e4 | 63 | |
f7fa9b10 | 64 | #define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8) |
b4ff4f04 | 65 | #define NLGRPLONGS(x) (NLGRPSZ(x)/sizeof(unsigned long)) |
1da177e4 LT |
66 | |
67 | struct netlink_sock { | |
68 | /* struct sock has to be the first member of netlink_sock */ | |
69 | struct sock sk; | |
70 | u32 pid; | |
1da177e4 | 71 | u32 dst_pid; |
d629b836 | 72 | u32 dst_group; |
f7fa9b10 PM |
73 | u32 flags; |
74 | u32 subscriptions; | |
75 | u32 ngroups; | |
76 | unsigned long *groups; | |
1da177e4 LT |
77 | unsigned long state; |
78 | wait_queue_head_t wait; | |
79 | struct netlink_callback *cb; | |
af65bdfc PM |
80 | struct mutex *cb_mutex; |
81 | struct mutex cb_def_mutex; | |
cd40b7d3 | 82 | void (*netlink_rcv)(struct sk_buff *skb); |
77247bbb | 83 | struct module *module; |
1da177e4 LT |
84 | }; |
85 | ||
77247bbb | 86 | #define NETLINK_KERNEL_SOCKET 0x1 |
9a4595bc | 87 | #define NETLINK_RECV_PKTINFO 0x2 |
be0c22a4 | 88 | #define NETLINK_BROADCAST_SEND_ERROR 0x4 |
77247bbb | 89 | |
1da177e4 LT |
90 | static inline struct netlink_sock *nlk_sk(struct sock *sk) |
91 | { | |
32b21e03 | 92 | return container_of(sk, struct netlink_sock, sk); |
1da177e4 LT |
93 | } |
94 | ||
aed81560 DL |
95 | static inline int netlink_is_kernel(struct sock *sk) |
96 | { | |
97 | return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET; | |
98 | } | |
99 | ||
1da177e4 LT |
100 | struct 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 | ||
113 | struct netlink_table { | |
114 | struct nl_pid_hash hash; | |
115 | struct hlist_head mc_list; | |
4277a083 | 116 | unsigned long *listeners; |
1da177e4 | 117 | unsigned int nl_nonroot; |
f7fa9b10 | 118 | unsigned int groups; |
af65bdfc | 119 | struct mutex *cb_mutex; |
77247bbb | 120 | struct module *module; |
ab33a171 | 121 | int registered; |
1da177e4 LT |
122 | }; |
123 | ||
124 | static struct netlink_table *nl_table; | |
125 | ||
126 | static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); | |
127 | ||
128 | static int netlink_dump(struct sock *sk); | |
129 | static void netlink_destroy_callback(struct netlink_callback *cb); | |
130 | ||
131 | static DEFINE_RWLOCK(nl_table_lock); | |
132 | static atomic_t nl_table_users = ATOMIC_INIT(0); | |
133 | ||
e041c683 | 134 | static ATOMIC_NOTIFIER_HEAD(netlink_chain); |
1da177e4 | 135 | |
d629b836 PM |
136 | static u32 netlink_group_mask(u32 group) |
137 | { | |
138 | return group ? 1 << (group - 1) : 0; | |
139 | } | |
140 | ||
1da177e4 LT |
141 | static 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 | ||
146 | static void netlink_sock_destruct(struct sock *sk) | |
147 | { | |
3f660d66 HX |
148 | struct netlink_sock *nlk = nlk_sk(sk); |
149 | ||
3f660d66 HX |
150 | if (nlk->cb) { |
151 | if (nlk->cb->done) | |
152 | nlk->cb->done(nlk->cb); | |
153 | netlink_destroy_callback(nlk->cb); | |
154 | } | |
155 | ||
1da177e4 LT |
156 | skb_queue_purge(&sk->sk_receive_queue); |
157 | ||
158 | if (!sock_flag(sk, SOCK_DEAD)) { | |
6ac552fd | 159 | printk(KERN_ERR "Freeing alive netlink socket %p\n", sk); |
1da177e4 LT |
160 | return; |
161 | } | |
547b792c IJ |
162 | |
163 | WARN_ON(atomic_read(&sk->sk_rmem_alloc)); | |
164 | WARN_ON(atomic_read(&sk->sk_wmem_alloc)); | |
165 | WARN_ON(nlk_sk(sk)->groups); | |
1da177e4 LT |
166 | } |
167 | ||
6ac552fd PM |
168 | /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on |
169 | * SMP. Look, when several writers sleep and reader wakes them up, all but one | |
1da177e4 LT |
170 | * immediately hit write lock and grab all the cpus. Exclusive sleep solves |
171 | * this, _but_ remember, it adds useless work on UP machines. | |
172 | */ | |
173 | ||
174 | static void netlink_table_grab(void) | |
9a429c49 | 175 | __acquires(nl_table_lock) |
1da177e4 | 176 | { |
6abd219c | 177 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
178 | |
179 | if (atomic_read(&nl_table_users)) { | |
180 | DECLARE_WAITQUEUE(wait, current); | |
181 | ||
182 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
6ac552fd | 183 | for (;;) { |
1da177e4 LT |
184 | set_current_state(TASK_UNINTERRUPTIBLE); |
185 | if (atomic_read(&nl_table_users) == 0) | |
186 | break; | |
6abd219c | 187 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 188 | schedule(); |
6abd219c | 189 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
190 | } |
191 | ||
192 | __set_current_state(TASK_RUNNING); | |
193 | remove_wait_queue(&nl_table_wait, &wait); | |
194 | } | |
195 | } | |
196 | ||
3f252526 | 197 | static void netlink_table_ungrab(void) |
9a429c49 | 198 | __releases(nl_table_lock) |
1da177e4 | 199 | { |
6abd219c | 200 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
201 | wake_up(&nl_table_wait); |
202 | } | |
203 | ||
6ac552fd | 204 | static inline void |
1da177e4 LT |
205 | netlink_lock_table(void) |
206 | { | |
207 | /* read_lock() synchronizes us to netlink_table_grab */ | |
208 | ||
209 | read_lock(&nl_table_lock); | |
210 | atomic_inc(&nl_table_users); | |
211 | read_unlock(&nl_table_lock); | |
212 | } | |
213 | ||
6ac552fd | 214 | static inline void |
1da177e4 LT |
215 | netlink_unlock_table(void) |
216 | { | |
217 | if (atomic_dec_and_test(&nl_table_users)) | |
218 | wake_up(&nl_table_wait); | |
219 | } | |
220 | ||
6ac552fd PM |
221 | static inline struct sock *netlink_lookup(struct net *net, int protocol, |
222 | u32 pid) | |
1da177e4 LT |
223 | { |
224 | struct nl_pid_hash *hash = &nl_table[protocol].hash; | |
225 | struct hlist_head *head; | |
226 | struct sock *sk; | |
227 | struct hlist_node *node; | |
228 | ||
229 | read_lock(&nl_table_lock); | |
230 | head = nl_pid_hashfn(hash, pid); | |
231 | sk_for_each(sk, node, head) { | |
878628fb | 232 | if (net_eq(sock_net(sk), net) && (nlk_sk(sk)->pid == pid)) { |
1da177e4 LT |
233 | sock_hold(sk); |
234 | goto found; | |
235 | } | |
236 | } | |
237 | sk = NULL; | |
238 | found: | |
239 | read_unlock(&nl_table_lock); | |
240 | return sk; | |
241 | } | |
242 | ||
ea72912c | 243 | static inline struct hlist_head *nl_pid_hash_zalloc(size_t size) |
1da177e4 LT |
244 | { |
245 | if (size <= PAGE_SIZE) | |
ea72912c | 246 | return kzalloc(size, GFP_ATOMIC); |
1da177e4 LT |
247 | else |
248 | return (struct hlist_head *) | |
ea72912c ED |
249 | __get_free_pages(GFP_ATOMIC | __GFP_ZERO, |
250 | get_order(size)); | |
1da177e4 LT |
251 | } |
252 | ||
253 | static inline void nl_pid_hash_free(struct hlist_head *table, size_t size) | |
254 | { | |
255 | if (size <= PAGE_SIZE) | |
256 | kfree(table); | |
257 | else | |
258 | free_pages((unsigned long)table, get_order(size)); | |
259 | } | |
260 | ||
261 | static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow) | |
262 | { | |
263 | unsigned int omask, mask, shift; | |
264 | size_t osize, size; | |
265 | struct hlist_head *otable, *table; | |
266 | int i; | |
267 | ||
268 | omask = mask = hash->mask; | |
269 | osize = size = (mask + 1) * sizeof(*table); | |
270 | shift = hash->shift; | |
271 | ||
272 | if (grow) { | |
273 | if (++shift > hash->max_shift) | |
274 | return 0; | |
275 | mask = mask * 2 + 1; | |
276 | size *= 2; | |
277 | } | |
278 | ||
ea72912c | 279 | table = nl_pid_hash_zalloc(size); |
1da177e4 LT |
280 | if (!table) |
281 | return 0; | |
282 | ||
1da177e4 LT |
283 | otable = hash->table; |
284 | hash->table = table; | |
285 | hash->mask = mask; | |
286 | hash->shift = shift; | |
287 | get_random_bytes(&hash->rnd, sizeof(hash->rnd)); | |
288 | ||
289 | for (i = 0; i <= omask; i++) { | |
290 | struct sock *sk; | |
291 | struct hlist_node *node, *tmp; | |
292 | ||
293 | sk_for_each_safe(sk, node, tmp, &otable[i]) | |
294 | __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid)); | |
295 | } | |
296 | ||
297 | nl_pid_hash_free(otable, osize); | |
298 | hash->rehash_time = jiffies + 10 * 60 * HZ; | |
299 | return 1; | |
300 | } | |
301 | ||
302 | static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len) | |
303 | { | |
304 | int avg = hash->entries >> hash->shift; | |
305 | ||
306 | if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1)) | |
307 | return 1; | |
308 | ||
309 | if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) { | |
310 | nl_pid_hash_rehash(hash, 0); | |
311 | return 1; | |
312 | } | |
313 | ||
314 | return 0; | |
315 | } | |
316 | ||
90ddc4f0 | 317 | static const struct proto_ops netlink_ops; |
1da177e4 | 318 | |
4277a083 PM |
319 | static void |
320 | netlink_update_listeners(struct sock *sk) | |
321 | { | |
322 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
323 | struct hlist_node *node; | |
324 | unsigned long mask; | |
325 | unsigned int i; | |
326 | ||
b4ff4f04 | 327 | for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
4277a083 | 328 | mask = 0; |
b4ff4f04 JB |
329 | sk_for_each_bound(sk, node, &tbl->mc_list) { |
330 | if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) | |
331 | mask |= nlk_sk(sk)->groups[i]; | |
332 | } | |
4277a083 PM |
333 | tbl->listeners[i] = mask; |
334 | } | |
335 | /* this function is only called with the netlink table "grabbed", which | |
336 | * makes sure updates are visible before bind or setsockopt return. */ | |
337 | } | |
338 | ||
b4b51029 | 339 | static int netlink_insert(struct sock *sk, struct net *net, u32 pid) |
1da177e4 LT |
340 | { |
341 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; | |
342 | struct hlist_head *head; | |
343 | int err = -EADDRINUSE; | |
344 | struct sock *osk; | |
345 | struct hlist_node *node; | |
346 | int len; | |
347 | ||
348 | netlink_table_grab(); | |
349 | head = nl_pid_hashfn(hash, pid); | |
350 | len = 0; | |
351 | sk_for_each(osk, node, head) { | |
878628fb | 352 | if (net_eq(sock_net(osk), net) && (nlk_sk(osk)->pid == pid)) |
1da177e4 LT |
353 | break; |
354 | len++; | |
355 | } | |
356 | if (node) | |
357 | goto err; | |
358 | ||
359 | err = -EBUSY; | |
360 | if (nlk_sk(sk)->pid) | |
361 | goto err; | |
362 | ||
363 | err = -ENOMEM; | |
364 | if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX)) | |
365 | goto err; | |
366 | ||
367 | if (len && nl_pid_hash_dilute(hash, len)) | |
368 | head = nl_pid_hashfn(hash, pid); | |
369 | hash->entries++; | |
370 | nlk_sk(sk)->pid = pid; | |
371 | sk_add_node(sk, head); | |
372 | err = 0; | |
373 | ||
374 | err: | |
375 | netlink_table_ungrab(); | |
376 | return err; | |
377 | } | |
378 | ||
379 | static void netlink_remove(struct sock *sk) | |
380 | { | |
381 | netlink_table_grab(); | |
d470e3b4 DM |
382 | if (sk_del_node_init(sk)) |
383 | nl_table[sk->sk_protocol].hash.entries--; | |
f7fa9b10 | 384 | if (nlk_sk(sk)->subscriptions) |
1da177e4 LT |
385 | __sk_del_bind_node(sk); |
386 | netlink_table_ungrab(); | |
387 | } | |
388 | ||
389 | static struct proto netlink_proto = { | |
390 | .name = "NETLINK", | |
391 | .owner = THIS_MODULE, | |
392 | .obj_size = sizeof(struct netlink_sock), | |
393 | }; | |
394 | ||
1b8d7ae4 EB |
395 | static int __netlink_create(struct net *net, struct socket *sock, |
396 | struct mutex *cb_mutex, int protocol) | |
1da177e4 LT |
397 | { |
398 | struct sock *sk; | |
399 | struct netlink_sock *nlk; | |
ab33a171 PM |
400 | |
401 | sock->ops = &netlink_ops; | |
402 | ||
6257ff21 | 403 | sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto); |
ab33a171 PM |
404 | if (!sk) |
405 | return -ENOMEM; | |
406 | ||
407 | sock_init_data(sock, sk); | |
408 | ||
409 | nlk = nlk_sk(sk); | |
ffa4d721 PM |
410 | if (cb_mutex) |
411 | nlk->cb_mutex = cb_mutex; | |
412 | else { | |
413 | nlk->cb_mutex = &nlk->cb_def_mutex; | |
414 | mutex_init(nlk->cb_mutex); | |
415 | } | |
ab33a171 PM |
416 | init_waitqueue_head(&nlk->wait); |
417 | ||
418 | sk->sk_destruct = netlink_sock_destruct; | |
419 | sk->sk_protocol = protocol; | |
420 | return 0; | |
421 | } | |
422 | ||
1b8d7ae4 | 423 | static int netlink_create(struct net *net, struct socket *sock, int protocol) |
ab33a171 PM |
424 | { |
425 | struct module *module = NULL; | |
af65bdfc | 426 | struct mutex *cb_mutex; |
f7fa9b10 | 427 | struct netlink_sock *nlk; |
ab33a171 | 428 | int err = 0; |
1da177e4 LT |
429 | |
430 | sock->state = SS_UNCONNECTED; | |
431 | ||
432 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
433 | return -ESOCKTNOSUPPORT; | |
434 | ||
6ac552fd | 435 | if (protocol < 0 || protocol >= MAX_LINKS) |
1da177e4 LT |
436 | return -EPROTONOSUPPORT; |
437 | ||
77247bbb | 438 | netlink_lock_table(); |
95a5afca | 439 | #ifdef CONFIG_MODULES |
ab33a171 | 440 | if (!nl_table[protocol].registered) { |
77247bbb | 441 | netlink_unlock_table(); |
4fdb3bb7 | 442 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 443 | netlink_lock_table(); |
4fdb3bb7 | 444 | } |
ab33a171 PM |
445 | #endif |
446 | if (nl_table[protocol].registered && | |
447 | try_module_get(nl_table[protocol].module)) | |
448 | module = nl_table[protocol].module; | |
af65bdfc | 449 | cb_mutex = nl_table[protocol].cb_mutex; |
77247bbb | 450 | netlink_unlock_table(); |
4fdb3bb7 | 451 | |
6ac552fd PM |
452 | err = __netlink_create(net, sock, cb_mutex, protocol); |
453 | if (err < 0) | |
f7fa9b10 PM |
454 | goto out_module; |
455 | ||
6f756a8c | 456 | local_bh_disable(); |
c1fd3b94 | 457 | sock_prot_inuse_add(net, &netlink_proto, 1); |
6f756a8c DM |
458 | local_bh_enable(); |
459 | ||
f7fa9b10 | 460 | nlk = nlk_sk(sock->sk); |
f7fa9b10 | 461 | nlk->module = module; |
ab33a171 PM |
462 | out: |
463 | return err; | |
1da177e4 | 464 | |
ab33a171 PM |
465 | out_module: |
466 | module_put(module); | |
467 | goto out; | |
1da177e4 LT |
468 | } |
469 | ||
470 | static int netlink_release(struct socket *sock) | |
471 | { | |
472 | struct sock *sk = sock->sk; | |
473 | struct netlink_sock *nlk; | |
474 | ||
475 | if (!sk) | |
476 | return 0; | |
477 | ||
478 | netlink_remove(sk); | |
ac57b3a9 | 479 | sock_orphan(sk); |
1da177e4 LT |
480 | nlk = nlk_sk(sk); |
481 | ||
3f660d66 HX |
482 | /* |
483 | * OK. Socket is unlinked, any packets that arrive now | |
484 | * will be purged. | |
485 | */ | |
1da177e4 | 486 | |
1da177e4 LT |
487 | sock->sk = NULL; |
488 | wake_up_interruptible_all(&nlk->wait); | |
489 | ||
490 | skb_queue_purge(&sk->sk_write_queue); | |
491 | ||
f7fa9b10 | 492 | if (nlk->pid && !nlk->subscriptions) { |
1da177e4 | 493 | struct netlink_notify n = { |
3b1e0a65 | 494 | .net = sock_net(sk), |
1da177e4 LT |
495 | .protocol = sk->sk_protocol, |
496 | .pid = nlk->pid, | |
497 | }; | |
e041c683 AS |
498 | atomic_notifier_call_chain(&netlink_chain, |
499 | NETLINK_URELEASE, &n); | |
746fac4d | 500 | } |
4fdb3bb7 | 501 | |
5e7c001c | 502 | module_put(nlk->module); |
4fdb3bb7 | 503 | |
4277a083 | 504 | netlink_table_grab(); |
aed81560 | 505 | if (netlink_is_kernel(sk)) { |
869e58f8 DL |
506 | BUG_ON(nl_table[sk->sk_protocol].registered == 0); |
507 | if (--nl_table[sk->sk_protocol].registered == 0) { | |
508 | kfree(nl_table[sk->sk_protocol].listeners); | |
509 | nl_table[sk->sk_protocol].module = NULL; | |
510 | nl_table[sk->sk_protocol].registered = 0; | |
511 | } | |
4277a083 PM |
512 | } else if (nlk->subscriptions) |
513 | netlink_update_listeners(sk); | |
514 | netlink_table_ungrab(); | |
77247bbb | 515 | |
f7fa9b10 PM |
516 | kfree(nlk->groups); |
517 | nlk->groups = NULL; | |
518 | ||
3755810c | 519 | local_bh_disable(); |
c1fd3b94 | 520 | sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); |
3755810c | 521 | local_bh_enable(); |
1da177e4 LT |
522 | sock_put(sk); |
523 | return 0; | |
524 | } | |
525 | ||
526 | static int netlink_autobind(struct socket *sock) | |
527 | { | |
528 | struct sock *sk = sock->sk; | |
3b1e0a65 | 529 | struct net *net = sock_net(sk); |
1da177e4 LT |
530 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; |
531 | struct hlist_head *head; | |
532 | struct sock *osk; | |
533 | struct hlist_node *node; | |
c27bd492 | 534 | s32 pid = current->tgid; |
1da177e4 LT |
535 | int err; |
536 | static s32 rover = -4097; | |
537 | ||
538 | retry: | |
539 | cond_resched(); | |
540 | netlink_table_grab(); | |
541 | head = nl_pid_hashfn(hash, pid); | |
542 | sk_for_each(osk, node, head) { | |
878628fb | 543 | if (!net_eq(sock_net(osk), net)) |
b4b51029 | 544 | continue; |
1da177e4 LT |
545 | if (nlk_sk(osk)->pid == pid) { |
546 | /* Bind collision, search negative pid values. */ | |
547 | pid = rover--; | |
548 | if (rover > -4097) | |
549 | rover = -4097; | |
550 | netlink_table_ungrab(); | |
551 | goto retry; | |
552 | } | |
553 | } | |
554 | netlink_table_ungrab(); | |
555 | ||
b4b51029 | 556 | err = netlink_insert(sk, net, pid); |
1da177e4 LT |
557 | if (err == -EADDRINUSE) |
558 | goto retry; | |
d470e3b4 DM |
559 | |
560 | /* If 2 threads race to autobind, that is fine. */ | |
561 | if (err == -EBUSY) | |
562 | err = 0; | |
563 | ||
564 | return err; | |
1da177e4 LT |
565 | } |
566 | ||
746fac4d YH |
567 | static inline int netlink_capable(struct socket *sock, unsigned int flag) |
568 | { | |
1da177e4 LT |
569 | return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) || |
570 | capable(CAP_NET_ADMIN); | |
746fac4d | 571 | } |
1da177e4 | 572 | |
f7fa9b10 PM |
573 | static void |
574 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
575 | { | |
576 | struct netlink_sock *nlk = nlk_sk(sk); | |
577 | ||
578 | if (nlk->subscriptions && !subscriptions) | |
579 | __sk_del_bind_node(sk); | |
580 | else if (!nlk->subscriptions && subscriptions) | |
581 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
582 | nlk->subscriptions = subscriptions; | |
583 | } | |
584 | ||
b4ff4f04 | 585 | static int netlink_realloc_groups(struct sock *sk) |
513c2500 PM |
586 | { |
587 | struct netlink_sock *nlk = nlk_sk(sk); | |
588 | unsigned int groups; | |
b4ff4f04 | 589 | unsigned long *new_groups; |
513c2500 PM |
590 | int err = 0; |
591 | ||
b4ff4f04 JB |
592 | netlink_table_grab(); |
593 | ||
513c2500 | 594 | groups = nl_table[sk->sk_protocol].groups; |
b4ff4f04 | 595 | if (!nl_table[sk->sk_protocol].registered) { |
513c2500 | 596 | err = -ENOENT; |
b4ff4f04 JB |
597 | goto out_unlock; |
598 | } | |
513c2500 | 599 | |
b4ff4f04 JB |
600 | if (nlk->ngroups >= groups) |
601 | goto out_unlock; | |
513c2500 | 602 | |
b4ff4f04 JB |
603 | new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
604 | if (new_groups == NULL) { | |
605 | err = -ENOMEM; | |
606 | goto out_unlock; | |
607 | } | |
6ac552fd | 608 | memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, |
b4ff4f04 JB |
609 | NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); |
610 | ||
611 | nlk->groups = new_groups; | |
513c2500 | 612 | nlk->ngroups = groups; |
b4ff4f04 JB |
613 | out_unlock: |
614 | netlink_table_ungrab(); | |
615 | return err; | |
513c2500 PM |
616 | } |
617 | ||
6ac552fd PM |
618 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, |
619 | int addr_len) | |
1da177e4 LT |
620 | { |
621 | struct sock *sk = sock->sk; | |
3b1e0a65 | 622 | struct net *net = sock_net(sk); |
1da177e4 LT |
623 | struct netlink_sock *nlk = nlk_sk(sk); |
624 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
625 | int err; | |
746fac4d | 626 | |
1da177e4 LT |
627 | if (nladdr->nl_family != AF_NETLINK) |
628 | return -EINVAL; | |
629 | ||
630 | /* Only superuser is allowed to listen multicasts */ | |
513c2500 PM |
631 | if (nladdr->nl_groups) { |
632 | if (!netlink_capable(sock, NL_NONROOT_RECV)) | |
633 | return -EPERM; | |
b4ff4f04 JB |
634 | err = netlink_realloc_groups(sk); |
635 | if (err) | |
636 | return err; | |
513c2500 | 637 | } |
1da177e4 LT |
638 | |
639 | if (nlk->pid) { | |
640 | if (nladdr->nl_pid != nlk->pid) | |
641 | return -EINVAL; | |
642 | } else { | |
643 | err = nladdr->nl_pid ? | |
b4b51029 | 644 | netlink_insert(sk, net, nladdr->nl_pid) : |
1da177e4 LT |
645 | netlink_autobind(sock); |
646 | if (err) | |
647 | return err; | |
648 | } | |
649 | ||
513c2500 | 650 | if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
1da177e4 LT |
651 | return 0; |
652 | ||
653 | netlink_table_grab(); | |
f7fa9b10 | 654 | netlink_update_subscriptions(sk, nlk->subscriptions + |
746fac4d YH |
655 | hweight32(nladdr->nl_groups) - |
656 | hweight32(nlk->groups[0])); | |
657 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups; | |
4277a083 | 658 | netlink_update_listeners(sk); |
1da177e4 LT |
659 | netlink_table_ungrab(); |
660 | ||
661 | return 0; | |
662 | } | |
663 | ||
664 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
665 | int alen, int flags) | |
666 | { | |
667 | int err = 0; | |
668 | struct sock *sk = sock->sk; | |
669 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 670 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
1da177e4 LT |
671 | |
672 | if (addr->sa_family == AF_UNSPEC) { | |
673 | sk->sk_state = NETLINK_UNCONNECTED; | |
674 | nlk->dst_pid = 0; | |
d629b836 | 675 | nlk->dst_group = 0; |
1da177e4 LT |
676 | return 0; |
677 | } | |
678 | if (addr->sa_family != AF_NETLINK) | |
679 | return -EINVAL; | |
680 | ||
681 | /* Only superuser is allowed to send multicasts */ | |
682 | if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND)) | |
683 | return -EPERM; | |
684 | ||
685 | if (!nlk->pid) | |
686 | err = netlink_autobind(sock); | |
687 | ||
688 | if (err == 0) { | |
689 | sk->sk_state = NETLINK_CONNECTED; | |
690 | nlk->dst_pid = nladdr->nl_pid; | |
d629b836 | 691 | nlk->dst_group = ffs(nladdr->nl_groups); |
1da177e4 LT |
692 | } |
693 | ||
694 | return err; | |
695 | } | |
696 | ||
6ac552fd PM |
697 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, |
698 | int *addr_len, int peer) | |
1da177e4 LT |
699 | { |
700 | struct sock *sk = sock->sk; | |
701 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 702 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
746fac4d | 703 | |
1da177e4 LT |
704 | nladdr->nl_family = AF_NETLINK; |
705 | nladdr->nl_pad = 0; | |
706 | *addr_len = sizeof(*nladdr); | |
707 | ||
708 | if (peer) { | |
709 | nladdr->nl_pid = nlk->dst_pid; | |
d629b836 | 710 | nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
1da177e4 LT |
711 | } else { |
712 | nladdr->nl_pid = nlk->pid; | |
513c2500 | 713 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
1da177e4 LT |
714 | } |
715 | return 0; | |
716 | } | |
717 | ||
718 | static void netlink_overrun(struct sock *sk) | |
719 | { | |
720 | if (!test_and_set_bit(0, &nlk_sk(sk)->state)) { | |
721 | sk->sk_err = ENOBUFS; | |
722 | sk->sk_error_report(sk); | |
723 | } | |
724 | } | |
725 | ||
726 | static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid) | |
727 | { | |
1da177e4 LT |
728 | struct sock *sock; |
729 | struct netlink_sock *nlk; | |
730 | ||
3b1e0a65 | 731 | sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, pid); |
1da177e4 LT |
732 | if (!sock) |
733 | return ERR_PTR(-ECONNREFUSED); | |
734 | ||
735 | /* Don't bother queuing skb if kernel socket has no input function */ | |
736 | nlk = nlk_sk(sock); | |
cd40b7d3 DL |
737 | if (sock->sk_state == NETLINK_CONNECTED && |
738 | nlk->dst_pid != nlk_sk(ssk)->pid) { | |
1da177e4 LT |
739 | sock_put(sock); |
740 | return ERR_PTR(-ECONNREFUSED); | |
741 | } | |
742 | return sock; | |
743 | } | |
744 | ||
745 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
746 | { | |
6db5fc5d | 747 | struct inode *inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
748 | struct sock *sock; |
749 | ||
750 | if (!S_ISSOCK(inode->i_mode)) | |
751 | return ERR_PTR(-ENOTSOCK); | |
752 | ||
753 | sock = SOCKET_I(inode)->sk; | |
754 | if (sock->sk_family != AF_NETLINK) | |
755 | return ERR_PTR(-EINVAL); | |
756 | ||
757 | sock_hold(sock); | |
758 | return sock; | |
759 | } | |
760 | ||
761 | /* | |
762 | * Attach a skb to a netlink socket. | |
763 | * The caller must hold a reference to the destination socket. On error, the | |
764 | * reference is dropped. The skb is not send to the destination, just all | |
765 | * all error checks are performed and memory in the queue is reserved. | |
766 | * Return values: | |
767 | * < 0: error. skb freed, reference to sock dropped. | |
768 | * 0: continue | |
769 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
770 | */ | |
9457afee | 771 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
c3d8d1e3 | 772 | long *timeo, struct sock *ssk) |
1da177e4 LT |
773 | { |
774 | struct netlink_sock *nlk; | |
775 | ||
776 | nlk = nlk_sk(sk); | |
777 | ||
778 | if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
779 | test_bit(0, &nlk->state)) { | |
780 | DECLARE_WAITQUEUE(wait, current); | |
c3d8d1e3 | 781 | if (!*timeo) { |
aed81560 | 782 | if (!ssk || netlink_is_kernel(ssk)) |
1da177e4 LT |
783 | netlink_overrun(sk); |
784 | sock_put(sk); | |
785 | kfree_skb(skb); | |
786 | return -EAGAIN; | |
787 | } | |
788 | ||
789 | __set_current_state(TASK_INTERRUPTIBLE); | |
790 | add_wait_queue(&nlk->wait, &wait); | |
791 | ||
792 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
793 | test_bit(0, &nlk->state)) && | |
794 | !sock_flag(sk, SOCK_DEAD)) | |
c3d8d1e3 | 795 | *timeo = schedule_timeout(*timeo); |
1da177e4 LT |
796 | |
797 | __set_current_state(TASK_RUNNING); | |
798 | remove_wait_queue(&nlk->wait, &wait); | |
799 | sock_put(sk); | |
800 | ||
801 | if (signal_pending(current)) { | |
802 | kfree_skb(skb); | |
c3d8d1e3 | 803 | return sock_intr_errno(*timeo); |
1da177e4 LT |
804 | } |
805 | return 1; | |
806 | } | |
807 | skb_set_owner_r(skb, sk); | |
808 | return 0; | |
809 | } | |
810 | ||
7ee015e0 | 811 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 812 | { |
1da177e4 LT |
813 | int len = skb->len; |
814 | ||
1da177e4 LT |
815 | skb_queue_tail(&sk->sk_receive_queue, skb); |
816 | sk->sk_data_ready(sk, len); | |
817 | sock_put(sk); | |
818 | return len; | |
819 | } | |
820 | ||
821 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
822 | { | |
823 | kfree_skb(skb); | |
824 | sock_put(sk); | |
825 | } | |
826 | ||
37da647d | 827 | static inline struct sk_buff *netlink_trim(struct sk_buff *skb, |
dd0fc66f | 828 | gfp_t allocation) |
1da177e4 LT |
829 | { |
830 | int delta; | |
831 | ||
832 | skb_orphan(skb); | |
833 | ||
4305b541 | 834 | delta = skb->end - skb->tail; |
1da177e4 LT |
835 | if (delta * 2 < skb->truesize) |
836 | return skb; | |
837 | ||
838 | if (skb_shared(skb)) { | |
839 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
840 | if (!nskb) | |
841 | return skb; | |
842 | kfree_skb(skb); | |
843 | skb = nskb; | |
844 | } | |
845 | ||
846 | if (!pskb_expand_head(skb, 0, -delta, allocation)) | |
847 | skb->truesize -= delta; | |
848 | ||
849 | return skb; | |
850 | } | |
851 | ||
cd40b7d3 DL |
852 | static inline void netlink_rcv_wake(struct sock *sk) |
853 | { | |
854 | struct netlink_sock *nlk = nlk_sk(sk); | |
855 | ||
856 | if (skb_queue_empty(&sk->sk_receive_queue)) | |
857 | clear_bit(0, &nlk->state); | |
858 | if (!test_bit(0, &nlk->state)) | |
859 | wake_up_interruptible(&nlk->wait); | |
860 | } | |
861 | ||
862 | static inline int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb) | |
863 | { | |
864 | int ret; | |
865 | struct netlink_sock *nlk = nlk_sk(sk); | |
866 | ||
867 | ret = -ECONNREFUSED; | |
868 | if (nlk->netlink_rcv != NULL) { | |
869 | ret = skb->len; | |
870 | skb_set_owner_r(skb, sk); | |
871 | nlk->netlink_rcv(skb); | |
872 | } | |
873 | kfree_skb(skb); | |
874 | sock_put(sk); | |
875 | return ret; | |
876 | } | |
877 | ||
878 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, | |
879 | u32 pid, int nonblock) | |
1da177e4 LT |
880 | { |
881 | struct sock *sk; | |
882 | int err; | |
883 | long timeo; | |
884 | ||
885 | skb = netlink_trim(skb, gfp_any()); | |
886 | ||
887 | timeo = sock_sndtimeo(ssk, nonblock); | |
888 | retry: | |
889 | sk = netlink_getsockbypid(ssk, pid); | |
890 | if (IS_ERR(sk)) { | |
891 | kfree_skb(skb); | |
892 | return PTR_ERR(sk); | |
893 | } | |
cd40b7d3 DL |
894 | if (netlink_is_kernel(sk)) |
895 | return netlink_unicast_kernel(sk, skb); | |
896 | ||
b1153f29 | 897 | if (sk_filter(sk, skb)) { |
84874607 | 898 | err = skb->len; |
b1153f29 SH |
899 | kfree_skb(skb); |
900 | sock_put(sk); | |
901 | return err; | |
902 | } | |
903 | ||
9457afee | 904 | err = netlink_attachskb(sk, skb, &timeo, ssk); |
1da177e4 LT |
905 | if (err == 1) |
906 | goto retry; | |
907 | if (err) | |
908 | return err; | |
909 | ||
7ee015e0 | 910 | return netlink_sendskb(sk, skb); |
1da177e4 | 911 | } |
6ac552fd | 912 | EXPORT_SYMBOL(netlink_unicast); |
1da177e4 | 913 | |
4277a083 PM |
914 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
915 | { | |
916 | int res = 0; | |
b4ff4f04 | 917 | unsigned long *listeners; |
4277a083 | 918 | |
aed81560 | 919 | BUG_ON(!netlink_is_kernel(sk)); |
b4ff4f04 JB |
920 | |
921 | rcu_read_lock(); | |
922 | listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); | |
923 | ||
4277a083 | 924 | if (group - 1 < nl_table[sk->sk_protocol].groups) |
b4ff4f04 JB |
925 | res = test_bit(group - 1, listeners); |
926 | ||
927 | rcu_read_unlock(); | |
928 | ||
4277a083 PM |
929 | return res; |
930 | } | |
931 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
932 | ||
6ac552fd PM |
933 | static inline int netlink_broadcast_deliver(struct sock *sk, |
934 | struct sk_buff *skb) | |
1da177e4 LT |
935 | { |
936 | struct netlink_sock *nlk = nlk_sk(sk); | |
937 | ||
938 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
939 | !test_bit(0, &nlk->state)) { | |
940 | skb_set_owner_r(skb, sk); | |
941 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
942 | sk->sk_data_ready(sk, skb->len); | |
943 | return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf; | |
944 | } | |
945 | return -1; | |
946 | } | |
947 | ||
948 | struct netlink_broadcast_data { | |
949 | struct sock *exclude_sk; | |
b4b51029 | 950 | struct net *net; |
1da177e4 LT |
951 | u32 pid; |
952 | u32 group; | |
953 | int failure; | |
ff491a73 | 954 | int delivery_failure; |
1da177e4 LT |
955 | int congested; |
956 | int delivered; | |
7d877f3b | 957 | gfp_t allocation; |
1da177e4 LT |
958 | struct sk_buff *skb, *skb2; |
959 | }; | |
960 | ||
961 | static inline int do_one_broadcast(struct sock *sk, | |
962 | struct netlink_broadcast_data *p) | |
963 | { | |
964 | struct netlink_sock *nlk = nlk_sk(sk); | |
965 | int val; | |
966 | ||
967 | if (p->exclude_sk == sk) | |
968 | goto out; | |
969 | ||
f7fa9b10 PM |
970 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
971 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
972 | goto out; |
973 | ||
878628fb | 974 | if (!net_eq(sock_net(sk), p->net)) |
b4b51029 EB |
975 | goto out; |
976 | ||
1da177e4 LT |
977 | if (p->failure) { |
978 | netlink_overrun(sk); | |
979 | goto out; | |
980 | } | |
981 | ||
982 | sock_hold(sk); | |
983 | if (p->skb2 == NULL) { | |
68acc024 | 984 | if (skb_shared(p->skb)) { |
1da177e4 LT |
985 | p->skb2 = skb_clone(p->skb, p->allocation); |
986 | } else { | |
68acc024 TC |
987 | p->skb2 = skb_get(p->skb); |
988 | /* | |
989 | * skb ownership may have been set when | |
990 | * delivered to a previous socket. | |
991 | */ | |
992 | skb_orphan(p->skb2); | |
1da177e4 LT |
993 | } |
994 | } | |
995 | if (p->skb2 == NULL) { | |
996 | netlink_overrun(sk); | |
997 | /* Clone failed. Notify ALL listeners. */ | |
998 | p->failure = 1; | |
be0c22a4 PNA |
999 | if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) |
1000 | p->delivery_failure = 1; | |
b1153f29 SH |
1001 | } else if (sk_filter(sk, p->skb2)) { |
1002 | kfree_skb(p->skb2); | |
1003 | p->skb2 = NULL; | |
1da177e4 LT |
1004 | } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) { |
1005 | netlink_overrun(sk); | |
be0c22a4 PNA |
1006 | if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) |
1007 | p->delivery_failure = 1; | |
1da177e4 LT |
1008 | } else { |
1009 | p->congested |= val; | |
1010 | p->delivered = 1; | |
1011 | p->skb2 = NULL; | |
1012 | } | |
1013 | sock_put(sk); | |
1014 | ||
1015 | out: | |
1016 | return 0; | |
1017 | } | |
1018 | ||
1019 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid, | |
dd0fc66f | 1020 | u32 group, gfp_t allocation) |
1da177e4 | 1021 | { |
3b1e0a65 | 1022 | struct net *net = sock_net(ssk); |
1da177e4 LT |
1023 | struct netlink_broadcast_data info; |
1024 | struct hlist_node *node; | |
1025 | struct sock *sk; | |
1026 | ||
1027 | skb = netlink_trim(skb, allocation); | |
1028 | ||
1029 | info.exclude_sk = ssk; | |
b4b51029 | 1030 | info.net = net; |
1da177e4 LT |
1031 | info.pid = pid; |
1032 | info.group = group; | |
1033 | info.failure = 0; | |
ff491a73 | 1034 | info.delivery_failure = 0; |
1da177e4 LT |
1035 | info.congested = 0; |
1036 | info.delivered = 0; | |
1037 | info.allocation = allocation; | |
1038 | info.skb = skb; | |
1039 | info.skb2 = NULL; | |
1040 | ||
1041 | /* While we sleep in clone, do not allow to change socket list */ | |
1042 | ||
1043 | netlink_lock_table(); | |
1044 | ||
1045 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1046 | do_one_broadcast(sk, &info); | |
1047 | ||
aa1c6a6f TC |
1048 | kfree_skb(skb); |
1049 | ||
1da177e4 LT |
1050 | netlink_unlock_table(); |
1051 | ||
1052 | if (info.skb2) | |
1053 | kfree_skb(info.skb2); | |
1da177e4 | 1054 | |
be0c22a4 | 1055 | if (info.delivery_failure) |
ff491a73 PNA |
1056 | return -ENOBUFS; |
1057 | ||
1da177e4 LT |
1058 | if (info.delivered) { |
1059 | if (info.congested && (allocation & __GFP_WAIT)) | |
1060 | yield(); | |
1061 | return 0; | |
1062 | } | |
1da177e4 LT |
1063 | return -ESRCH; |
1064 | } | |
6ac552fd | 1065 | EXPORT_SYMBOL(netlink_broadcast); |
1da177e4 LT |
1066 | |
1067 | struct netlink_set_err_data { | |
1068 | struct sock *exclude_sk; | |
1069 | u32 pid; | |
1070 | u32 group; | |
1071 | int code; | |
1072 | }; | |
1073 | ||
1074 | static inline int do_one_set_err(struct sock *sk, | |
1075 | struct netlink_set_err_data *p) | |
1076 | { | |
1077 | struct netlink_sock *nlk = nlk_sk(sk); | |
1078 | ||
1079 | if (sk == p->exclude_sk) | |
1080 | goto out; | |
1081 | ||
3b1e0a65 | 1082 | if (sock_net(sk) != sock_net(p->exclude_sk)) |
b4b51029 EB |
1083 | goto out; |
1084 | ||
f7fa9b10 PM |
1085 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
1086 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
1087 | goto out; |
1088 | ||
1089 | sk->sk_err = p->code; | |
1090 | sk->sk_error_report(sk); | |
1091 | out: | |
1092 | return 0; | |
1093 | } | |
1094 | ||
1095 | void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) | |
1096 | { | |
1097 | struct netlink_set_err_data info; | |
1098 | struct hlist_node *node; | |
1099 | struct sock *sk; | |
1100 | ||
1101 | info.exclude_sk = ssk; | |
1102 | info.pid = pid; | |
1103 | info.group = group; | |
1104 | info.code = code; | |
1105 | ||
1106 | read_lock(&nl_table_lock); | |
1107 | ||
1108 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1109 | do_one_set_err(sk, &info); | |
1110 | ||
1111 | read_unlock(&nl_table_lock); | |
1112 | } | |
1113 | ||
84659eb5 JB |
1114 | /* must be called with netlink table grabbed */ |
1115 | static void netlink_update_socket_mc(struct netlink_sock *nlk, | |
1116 | unsigned int group, | |
1117 | int is_new) | |
1118 | { | |
1119 | int old, new = !!is_new, subscriptions; | |
1120 | ||
1121 | old = test_bit(group - 1, nlk->groups); | |
1122 | subscriptions = nlk->subscriptions - old + new; | |
1123 | if (new) | |
1124 | __set_bit(group - 1, nlk->groups); | |
1125 | else | |
1126 | __clear_bit(group - 1, nlk->groups); | |
1127 | netlink_update_subscriptions(&nlk->sk, subscriptions); | |
1128 | netlink_update_listeners(&nlk->sk); | |
1129 | } | |
1130 | ||
9a4595bc | 1131 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
746fac4d | 1132 | char __user *optval, int optlen) |
9a4595bc PM |
1133 | { |
1134 | struct sock *sk = sock->sk; | |
1135 | struct netlink_sock *nlk = nlk_sk(sk); | |
eb496534 JB |
1136 | unsigned int val = 0; |
1137 | int err; | |
9a4595bc PM |
1138 | |
1139 | if (level != SOL_NETLINK) | |
1140 | return -ENOPROTOOPT; | |
1141 | ||
1142 | if (optlen >= sizeof(int) && | |
eb496534 | 1143 | get_user(val, (unsigned int __user *)optval)) |
9a4595bc PM |
1144 | return -EFAULT; |
1145 | ||
1146 | switch (optname) { | |
1147 | case NETLINK_PKTINFO: | |
1148 | if (val) | |
1149 | nlk->flags |= NETLINK_RECV_PKTINFO; | |
1150 | else | |
1151 | nlk->flags &= ~NETLINK_RECV_PKTINFO; | |
1152 | err = 0; | |
1153 | break; | |
1154 | case NETLINK_ADD_MEMBERSHIP: | |
1155 | case NETLINK_DROP_MEMBERSHIP: { | |
9a4595bc PM |
1156 | if (!netlink_capable(sock, NL_NONROOT_RECV)) |
1157 | return -EPERM; | |
b4ff4f04 JB |
1158 | err = netlink_realloc_groups(sk); |
1159 | if (err) | |
1160 | return err; | |
9a4595bc PM |
1161 | if (!val || val - 1 >= nlk->ngroups) |
1162 | return -EINVAL; | |
1163 | netlink_table_grab(); | |
84659eb5 JB |
1164 | netlink_update_socket_mc(nlk, val, |
1165 | optname == NETLINK_ADD_MEMBERSHIP); | |
9a4595bc PM |
1166 | netlink_table_ungrab(); |
1167 | err = 0; | |
1168 | break; | |
1169 | } | |
be0c22a4 PNA |
1170 | case NETLINK_BROADCAST_ERROR: |
1171 | if (val) | |
1172 | nlk->flags |= NETLINK_BROADCAST_SEND_ERROR; | |
1173 | else | |
1174 | nlk->flags &= ~NETLINK_BROADCAST_SEND_ERROR; | |
1175 | err = 0; | |
1176 | break; | |
9a4595bc PM |
1177 | default: |
1178 | err = -ENOPROTOOPT; | |
1179 | } | |
1180 | return err; | |
1181 | } | |
1182 | ||
1183 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
746fac4d | 1184 | char __user *optval, int __user *optlen) |
9a4595bc PM |
1185 | { |
1186 | struct sock *sk = sock->sk; | |
1187 | struct netlink_sock *nlk = nlk_sk(sk); | |
1188 | int len, val, err; | |
1189 | ||
1190 | if (level != SOL_NETLINK) | |
1191 | return -ENOPROTOOPT; | |
1192 | ||
1193 | if (get_user(len, optlen)) | |
1194 | return -EFAULT; | |
1195 | if (len < 0) | |
1196 | return -EINVAL; | |
1197 | ||
1198 | switch (optname) { | |
1199 | case NETLINK_PKTINFO: | |
1200 | if (len < sizeof(int)) | |
1201 | return -EINVAL; | |
1202 | len = sizeof(int); | |
1203 | val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0; | |
a27b58fe HC |
1204 | if (put_user(len, optlen) || |
1205 | put_user(val, optval)) | |
1206 | return -EFAULT; | |
9a4595bc PM |
1207 | err = 0; |
1208 | break; | |
be0c22a4 PNA |
1209 | case NETLINK_BROADCAST_ERROR: |
1210 | if (len < sizeof(int)) | |
1211 | return -EINVAL; | |
1212 | len = sizeof(int); | |
1213 | val = nlk->flags & NETLINK_BROADCAST_SEND_ERROR ? 1 : 0; | |
1214 | if (put_user(len, optlen) || | |
1215 | put_user(val, optval)) | |
1216 | return -EFAULT; | |
1217 | err = 0; | |
1218 | break; | |
9a4595bc PM |
1219 | default: |
1220 | err = -ENOPROTOOPT; | |
1221 | } | |
1222 | return err; | |
1223 | } | |
1224 | ||
1225 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
1226 | { | |
1227 | struct nl_pktinfo info; | |
1228 | ||
1229 | info.group = NETLINK_CB(skb).dst_group; | |
1230 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
1231 | } | |
1232 | ||
1da177e4 LT |
1233 | static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, |
1234 | struct msghdr *msg, size_t len) | |
1235 | { | |
1236 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1237 | struct sock *sk = sock->sk; | |
1238 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 1239 | struct sockaddr_nl *addr = msg->msg_name; |
1da177e4 | 1240 | u32 dst_pid; |
d629b836 | 1241 | u32 dst_group; |
1da177e4 LT |
1242 | struct sk_buff *skb; |
1243 | int err; | |
1244 | struct scm_cookie scm; | |
1245 | ||
1246 | if (msg->msg_flags&MSG_OOB) | |
1247 | return -EOPNOTSUPP; | |
1248 | ||
1249 | if (NULL == siocb->scm) | |
1250 | siocb->scm = &scm; | |
1251 | err = scm_send(sock, msg, siocb->scm); | |
1252 | if (err < 0) | |
1253 | return err; | |
1254 | ||
1255 | if (msg->msg_namelen) { | |
1256 | if (addr->nl_family != AF_NETLINK) | |
1257 | return -EINVAL; | |
1258 | dst_pid = addr->nl_pid; | |
d629b836 PM |
1259 | dst_group = ffs(addr->nl_groups); |
1260 | if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND)) | |
1da177e4 LT |
1261 | return -EPERM; |
1262 | } else { | |
1263 | dst_pid = nlk->dst_pid; | |
d629b836 | 1264 | dst_group = nlk->dst_group; |
1da177e4 LT |
1265 | } |
1266 | ||
1267 | if (!nlk->pid) { | |
1268 | err = netlink_autobind(sock); | |
1269 | if (err) | |
1270 | goto out; | |
1271 | } | |
1272 | ||
1273 | err = -EMSGSIZE; | |
1274 | if (len > sk->sk_sndbuf - 32) | |
1275 | goto out; | |
1276 | err = -ENOBUFS; | |
339bf98f | 1277 | skb = alloc_skb(len, GFP_KERNEL); |
6ac552fd | 1278 | if (skb == NULL) |
1da177e4 LT |
1279 | goto out; |
1280 | ||
1281 | NETLINK_CB(skb).pid = nlk->pid; | |
d629b836 | 1282 | NETLINK_CB(skb).dst_group = dst_group; |
0c11b942 | 1283 | NETLINK_CB(skb).loginuid = audit_get_loginuid(current); |
2532386f | 1284 | NETLINK_CB(skb).sessionid = audit_get_sessionid(current); |
0ce784ca | 1285 | security_task_getsecid(current, &(NETLINK_CB(skb).sid)); |
1da177e4 LT |
1286 | memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); |
1287 | ||
1288 | /* What can I do? Netlink is asynchronous, so that | |
1289 | we will have to save current capabilities to | |
1290 | check them, when this message will be delivered | |
1291 | to corresponding kernel module. --ANK (980802) | |
1292 | */ | |
1293 | ||
1294 | err = -EFAULT; | |
6ac552fd | 1295 | if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) { |
1da177e4 LT |
1296 | kfree_skb(skb); |
1297 | goto out; | |
1298 | } | |
1299 | ||
1300 | err = security_netlink_send(sk, skb); | |
1301 | if (err) { | |
1302 | kfree_skb(skb); | |
1303 | goto out; | |
1304 | } | |
1305 | ||
d629b836 | 1306 | if (dst_group) { |
1da177e4 | 1307 | atomic_inc(&skb->users); |
d629b836 | 1308 | netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL); |
1da177e4 LT |
1309 | } |
1310 | err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT); | |
1311 | ||
1312 | out: | |
1313 | return err; | |
1314 | } | |
1315 | ||
1316 | static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, | |
1317 | struct msghdr *msg, size_t len, | |
1318 | int flags) | |
1319 | { | |
1320 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1321 | struct scm_cookie scm; | |
1322 | struct sock *sk = sock->sk; | |
1323 | struct netlink_sock *nlk = nlk_sk(sk); | |
1324 | int noblock = flags&MSG_DONTWAIT; | |
1325 | size_t copied; | |
1326 | struct sk_buff *skb; | |
1327 | int err; | |
1328 | ||
1329 | if (flags&MSG_OOB) | |
1330 | return -EOPNOTSUPP; | |
1331 | ||
1332 | copied = 0; | |
1333 | ||
6ac552fd PM |
1334 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
1335 | if (skb == NULL) | |
1da177e4 LT |
1336 | goto out; |
1337 | ||
1338 | msg->msg_namelen = 0; | |
1339 | ||
1340 | copied = skb->len; | |
1341 | if (len < copied) { | |
1342 | msg->msg_flags |= MSG_TRUNC; | |
1343 | copied = len; | |
1344 | } | |
1345 | ||
badff6d0 | 1346 | skb_reset_transport_header(skb); |
1da177e4 LT |
1347 | err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); |
1348 | ||
1349 | if (msg->msg_name) { | |
6ac552fd | 1350 | struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name; |
1da177e4 LT |
1351 | addr->nl_family = AF_NETLINK; |
1352 | addr->nl_pad = 0; | |
1353 | addr->nl_pid = NETLINK_CB(skb).pid; | |
d629b836 | 1354 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
1355 | msg->msg_namelen = sizeof(*addr); |
1356 | } | |
1357 | ||
cc9a06cd PM |
1358 | if (nlk->flags & NETLINK_RECV_PKTINFO) |
1359 | netlink_cmsg_recv_pktinfo(msg, skb); | |
1360 | ||
1da177e4 LT |
1361 | if (NULL == siocb->scm) { |
1362 | memset(&scm, 0, sizeof(scm)); | |
1363 | siocb->scm = &scm; | |
1364 | } | |
1365 | siocb->scm->creds = *NETLINK_CREDS(skb); | |
188ccb55 PM |
1366 | if (flags & MSG_TRUNC) |
1367 | copied = skb->len; | |
1da177e4 LT |
1368 | skb_free_datagram(sk, skb); |
1369 | ||
1370 | if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) | |
1371 | netlink_dump(sk); | |
1372 | ||
1373 | scm_recv(sock, msg, siocb->scm, flags); | |
1da177e4 LT |
1374 | out: |
1375 | netlink_rcv_wake(sk); | |
1376 | return err ? : copied; | |
1377 | } | |
1378 | ||
1379 | static void netlink_data_ready(struct sock *sk, int len) | |
1380 | { | |
cd40b7d3 | 1381 | BUG(); |
1da177e4 LT |
1382 | } |
1383 | ||
1384 | /* | |
746fac4d | 1385 | * We export these functions to other modules. They provide a |
1da177e4 LT |
1386 | * complete set of kernel non-blocking support for message |
1387 | * queueing. | |
1388 | */ | |
1389 | ||
1390 | struct sock * | |
b4b51029 | 1391 | netlink_kernel_create(struct net *net, int unit, unsigned int groups, |
cd40b7d3 | 1392 | void (*input)(struct sk_buff *skb), |
af65bdfc | 1393 | struct mutex *cb_mutex, struct module *module) |
1da177e4 LT |
1394 | { |
1395 | struct socket *sock; | |
1396 | struct sock *sk; | |
77247bbb | 1397 | struct netlink_sock *nlk; |
4277a083 | 1398 | unsigned long *listeners = NULL; |
1da177e4 | 1399 | |
fab2caf6 | 1400 | BUG_ON(!nl_table); |
1da177e4 | 1401 | |
6ac552fd | 1402 | if (unit < 0 || unit >= MAX_LINKS) |
1da177e4 LT |
1403 | return NULL; |
1404 | ||
1405 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
1406 | return NULL; | |
1407 | ||
23fe1866 PE |
1408 | /* |
1409 | * We have to just have a reference on the net from sk, but don't | |
1410 | * get_net it. Besides, we cannot get and then put the net here. | |
1411 | * So we create one inside init_net and the move it to net. | |
1412 | */ | |
1413 | ||
1414 | if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0) | |
1415 | goto out_sock_release_nosk; | |
1416 | ||
1417 | sk = sock->sk; | |
edf02087 | 1418 | sk_change_net(sk, net); |
4fdb3bb7 | 1419 | |
4277a083 PM |
1420 | if (groups < 32) |
1421 | groups = 32; | |
1422 | ||
1423 | listeners = kzalloc(NLGRPSZ(groups), GFP_KERNEL); | |
1424 | if (!listeners) | |
1425 | goto out_sock_release; | |
1426 | ||
1da177e4 LT |
1427 | sk->sk_data_ready = netlink_data_ready; |
1428 | if (input) | |
cd40b7d3 | 1429 | nlk_sk(sk)->netlink_rcv = input; |
1da177e4 | 1430 | |
b4b51029 | 1431 | if (netlink_insert(sk, net, 0)) |
77247bbb | 1432 | goto out_sock_release; |
4fdb3bb7 | 1433 | |
77247bbb PM |
1434 | nlk = nlk_sk(sk); |
1435 | nlk->flags |= NETLINK_KERNEL_SOCKET; | |
4fdb3bb7 | 1436 | |
4fdb3bb7 | 1437 | netlink_table_grab(); |
b4b51029 EB |
1438 | if (!nl_table[unit].registered) { |
1439 | nl_table[unit].groups = groups; | |
1440 | nl_table[unit].listeners = listeners; | |
1441 | nl_table[unit].cb_mutex = cb_mutex; | |
1442 | nl_table[unit].module = module; | |
1443 | nl_table[unit].registered = 1; | |
f937f1f4 JJ |
1444 | } else { |
1445 | kfree(listeners); | |
869e58f8 | 1446 | nl_table[unit].registered++; |
b4b51029 | 1447 | } |
4fdb3bb7 | 1448 | netlink_table_ungrab(); |
77247bbb PM |
1449 | return sk; |
1450 | ||
4fdb3bb7 | 1451 | out_sock_release: |
4277a083 | 1452 | kfree(listeners); |
9dfbec1f | 1453 | netlink_kernel_release(sk); |
23fe1866 PE |
1454 | return NULL; |
1455 | ||
1456 | out_sock_release_nosk: | |
4fdb3bb7 | 1457 | sock_release(sock); |
77247bbb | 1458 | return NULL; |
1da177e4 | 1459 | } |
6ac552fd | 1460 | EXPORT_SYMBOL(netlink_kernel_create); |
1da177e4 | 1461 | |
b7c6ba6e DL |
1462 | |
1463 | void | |
1464 | netlink_kernel_release(struct sock *sk) | |
1465 | { | |
edf02087 | 1466 | sk_release_kernel(sk); |
b7c6ba6e DL |
1467 | } |
1468 | EXPORT_SYMBOL(netlink_kernel_release); | |
1469 | ||
1470 | ||
b4ff4f04 JB |
1471 | /** |
1472 | * netlink_change_ngroups - change number of multicast groups | |
1473 | * | |
1474 | * This changes the number of multicast groups that are available | |
1475 | * on a certain netlink family. Note that it is not possible to | |
84659eb5 JB |
1476 | * change the number of groups to below 32. Also note that it does |
1477 | * not implicitly call netlink_clear_multicast_users() when the | |
1478 | * number of groups is reduced. | |
b4ff4f04 JB |
1479 | * |
1480 | * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). | |
1481 | * @groups: The new number of groups. | |
1482 | */ | |
1483 | int netlink_change_ngroups(struct sock *sk, unsigned int groups) | |
1484 | { | |
1485 | unsigned long *listeners, *old = NULL; | |
1486 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
1487 | int err = 0; | |
1488 | ||
1489 | if (groups < 32) | |
1490 | groups = 32; | |
1491 | ||
1492 | netlink_table_grab(); | |
1493 | if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { | |
1494 | listeners = kzalloc(NLGRPSZ(groups), GFP_ATOMIC); | |
1495 | if (!listeners) { | |
1496 | err = -ENOMEM; | |
1497 | goto out_ungrab; | |
1498 | } | |
1499 | old = tbl->listeners; | |
1500 | memcpy(listeners, old, NLGRPSZ(tbl->groups)); | |
1501 | rcu_assign_pointer(tbl->listeners, listeners); | |
1502 | } | |
1503 | tbl->groups = groups; | |
1504 | ||
1505 | out_ungrab: | |
1506 | netlink_table_ungrab(); | |
1507 | synchronize_rcu(); | |
1508 | kfree(old); | |
1509 | return err; | |
1510 | } | |
1511 | EXPORT_SYMBOL(netlink_change_ngroups); | |
1512 | ||
84659eb5 JB |
1513 | /** |
1514 | * netlink_clear_multicast_users - kick off multicast listeners | |
1515 | * | |
1516 | * This function removes all listeners from the given group. | |
1517 | * @ksk: The kernel netlink socket, as returned by | |
1518 | * netlink_kernel_create(). | |
1519 | * @group: The multicast group to clear. | |
1520 | */ | |
1521 | void netlink_clear_multicast_users(struct sock *ksk, unsigned int group) | |
1522 | { | |
1523 | struct sock *sk; | |
1524 | struct hlist_node *node; | |
1525 | struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; | |
1526 | ||
1527 | netlink_table_grab(); | |
1528 | ||
1529 | sk_for_each_bound(sk, node, &tbl->mc_list) | |
1530 | netlink_update_socket_mc(nlk_sk(sk), group, 0); | |
1531 | ||
1532 | netlink_table_ungrab(); | |
1533 | } | |
1534 | EXPORT_SYMBOL(netlink_clear_multicast_users); | |
1535 | ||
1da177e4 | 1536 | void netlink_set_nonroot(int protocol, unsigned int flags) |
746fac4d YH |
1537 | { |
1538 | if ((unsigned int)protocol < MAX_LINKS) | |
1da177e4 | 1539 | nl_table[protocol].nl_nonroot = flags; |
746fac4d | 1540 | } |
6ac552fd | 1541 | EXPORT_SYMBOL(netlink_set_nonroot); |
1da177e4 LT |
1542 | |
1543 | static void netlink_destroy_callback(struct netlink_callback *cb) | |
1544 | { | |
1545 | if (cb->skb) | |
1546 | kfree_skb(cb->skb); | |
1547 | kfree(cb); | |
1548 | } | |
1549 | ||
1550 | /* | |
1551 | * It looks a bit ugly. | |
1552 | * It would be better to create kernel thread. | |
1553 | */ | |
1554 | ||
1555 | static int netlink_dump(struct sock *sk) | |
1556 | { | |
1557 | struct netlink_sock *nlk = nlk_sk(sk); | |
1558 | struct netlink_callback *cb; | |
1559 | struct sk_buff *skb; | |
1560 | struct nlmsghdr *nlh; | |
bf8b79e4 | 1561 | int len, err = -ENOBUFS; |
746fac4d | 1562 | |
1da177e4 LT |
1563 | skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL); |
1564 | if (!skb) | |
bf8b79e4 | 1565 | goto errout; |
1da177e4 | 1566 | |
af65bdfc | 1567 | mutex_lock(nlk->cb_mutex); |
1da177e4 LT |
1568 | |
1569 | cb = nlk->cb; | |
1570 | if (cb == NULL) { | |
bf8b79e4 TG |
1571 | err = -EINVAL; |
1572 | goto errout_skb; | |
1da177e4 LT |
1573 | } |
1574 | ||
1575 | len = cb->dump(skb, cb); | |
1576 | ||
1577 | if (len > 0) { | |
af65bdfc | 1578 | mutex_unlock(nlk->cb_mutex); |
b1153f29 SH |
1579 | |
1580 | if (sk_filter(sk, skb)) | |
1581 | kfree_skb(skb); | |
1582 | else { | |
1583 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
1584 | sk->sk_data_ready(sk, skb->len); | |
1585 | } | |
1da177e4 LT |
1586 | return 0; |
1587 | } | |
1588 | ||
bf8b79e4 TG |
1589 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); |
1590 | if (!nlh) | |
1591 | goto errout_skb; | |
1592 | ||
1593 | memcpy(nlmsg_data(nlh), &len, sizeof(len)); | |
1594 | ||
b1153f29 SH |
1595 | if (sk_filter(sk, skb)) |
1596 | kfree_skb(skb); | |
1597 | else { | |
1598 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
1599 | sk->sk_data_ready(sk, skb->len); | |
1600 | } | |
1da177e4 | 1601 | |
a8f74b22 TG |
1602 | if (cb->done) |
1603 | cb->done(cb); | |
1da177e4 | 1604 | nlk->cb = NULL; |
af65bdfc | 1605 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1606 | |
1607 | netlink_destroy_callback(cb); | |
1da177e4 | 1608 | return 0; |
1797754e | 1609 | |
bf8b79e4 | 1610 | errout_skb: |
af65bdfc | 1611 | mutex_unlock(nlk->cb_mutex); |
bf8b79e4 TG |
1612 | kfree_skb(skb); |
1613 | errout: | |
1614 | return err; | |
1da177e4 LT |
1615 | } |
1616 | ||
1617 | int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, | |
1618 | struct nlmsghdr *nlh, | |
6ac552fd PM |
1619 | int (*dump)(struct sk_buff *skb, |
1620 | struct netlink_callback *), | |
1621 | int (*done)(struct netlink_callback *)) | |
1da177e4 LT |
1622 | { |
1623 | struct netlink_callback *cb; | |
1624 | struct sock *sk; | |
1625 | struct netlink_sock *nlk; | |
1626 | ||
0da974f4 | 1627 | cb = kzalloc(sizeof(*cb), GFP_KERNEL); |
1da177e4 LT |
1628 | if (cb == NULL) |
1629 | return -ENOBUFS; | |
1630 | ||
1da177e4 LT |
1631 | cb->dump = dump; |
1632 | cb->done = done; | |
1633 | cb->nlh = nlh; | |
1634 | atomic_inc(&skb->users); | |
1635 | cb->skb = skb; | |
1636 | ||
3b1e0a65 | 1637 | sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).pid); |
1da177e4 LT |
1638 | if (sk == NULL) { |
1639 | netlink_destroy_callback(cb); | |
1640 | return -ECONNREFUSED; | |
1641 | } | |
1642 | nlk = nlk_sk(sk); | |
3f660d66 | 1643 | /* A dump is in progress... */ |
af65bdfc | 1644 | mutex_lock(nlk->cb_mutex); |
3f660d66 | 1645 | if (nlk->cb) { |
af65bdfc | 1646 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1647 | netlink_destroy_callback(cb); |
1648 | sock_put(sk); | |
1649 | return -EBUSY; | |
1650 | } | |
1651 | nlk->cb = cb; | |
af65bdfc | 1652 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1653 | |
1654 | netlink_dump(sk); | |
1655 | sock_put(sk); | |
5c58298c DL |
1656 | |
1657 | /* We successfully started a dump, by returning -EINTR we | |
1658 | * signal not to send ACK even if it was requested. | |
1659 | */ | |
1660 | return -EINTR; | |
1da177e4 | 1661 | } |
6ac552fd | 1662 | EXPORT_SYMBOL(netlink_dump_start); |
1da177e4 LT |
1663 | |
1664 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) | |
1665 | { | |
1666 | struct sk_buff *skb; | |
1667 | struct nlmsghdr *rep; | |
1668 | struct nlmsgerr *errmsg; | |
339bf98f | 1669 | size_t payload = sizeof(*errmsg); |
1da177e4 | 1670 | |
339bf98f TG |
1671 | /* error messages get the original request appened */ |
1672 | if (err) | |
1673 | payload += nlmsg_len(nlh); | |
1da177e4 | 1674 | |
339bf98f | 1675 | skb = nlmsg_new(payload, GFP_KERNEL); |
1da177e4 LT |
1676 | if (!skb) { |
1677 | struct sock *sk; | |
1678 | ||
3b1e0a65 | 1679 | sk = netlink_lookup(sock_net(in_skb->sk), |
b4b51029 | 1680 | in_skb->sk->sk_protocol, |
1da177e4 LT |
1681 | NETLINK_CB(in_skb).pid); |
1682 | if (sk) { | |
1683 | sk->sk_err = ENOBUFS; | |
1684 | sk->sk_error_report(sk); | |
1685 | sock_put(sk); | |
1686 | } | |
1687 | return; | |
1688 | } | |
1689 | ||
1690 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, | |
1797754e | 1691 | NLMSG_ERROR, sizeof(struct nlmsgerr), 0); |
bf8b79e4 | 1692 | errmsg = nlmsg_data(rep); |
1da177e4 | 1693 | errmsg->error = err; |
bf8b79e4 | 1694 | memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh)); |
1da177e4 LT |
1695 | netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT); |
1696 | } | |
6ac552fd | 1697 | EXPORT_SYMBOL(netlink_ack); |
1da177e4 | 1698 | |
cd40b7d3 | 1699 | int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
1d00a4eb | 1700 | struct nlmsghdr *)) |
82ace47a | 1701 | { |
82ace47a TG |
1702 | struct nlmsghdr *nlh; |
1703 | int err; | |
1704 | ||
1705 | while (skb->len >= nlmsg_total_size(0)) { | |
cd40b7d3 DL |
1706 | int msglen; |
1707 | ||
b529ccf2 | 1708 | nlh = nlmsg_hdr(skb); |
d35b6856 | 1709 | err = 0; |
82ace47a | 1710 | |
ad8e4b75 | 1711 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
1712 | return 0; |
1713 | ||
d35b6856 TG |
1714 | /* Only requests are handled by the kernel */ |
1715 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | |
5c58298c | 1716 | goto ack; |
45e7ae7f TG |
1717 | |
1718 | /* Skip control messages */ | |
1719 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | |
5c58298c | 1720 | goto ack; |
d35b6856 | 1721 | |
1d00a4eb | 1722 | err = cb(skb, nlh); |
5c58298c DL |
1723 | if (err == -EINTR) |
1724 | goto skip; | |
1725 | ||
1726 | ack: | |
d35b6856 | 1727 | if (nlh->nlmsg_flags & NLM_F_ACK || err) |
82ace47a | 1728 | netlink_ack(skb, nlh, err); |
82ace47a | 1729 | |
5c58298c | 1730 | skip: |
6ac552fd | 1731 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
cd40b7d3 DL |
1732 | if (msglen > skb->len) |
1733 | msglen = skb->len; | |
1734 | skb_pull(skb, msglen); | |
82ace47a TG |
1735 | } |
1736 | ||
1737 | return 0; | |
1738 | } | |
6ac552fd | 1739 | EXPORT_SYMBOL(netlink_rcv_skb); |
82ace47a | 1740 | |
d387f6ad TG |
1741 | /** |
1742 | * nlmsg_notify - send a notification netlink message | |
1743 | * @sk: netlink socket to use | |
1744 | * @skb: notification message | |
1745 | * @pid: destination netlink pid for reports or 0 | |
1746 | * @group: destination multicast group or 0 | |
1747 | * @report: 1 to report back, 0 to disable | |
1748 | * @flags: allocation flags | |
1749 | */ | |
1750 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid, | |
1751 | unsigned int group, int report, gfp_t flags) | |
1752 | { | |
1753 | int err = 0; | |
1754 | ||
1755 | if (group) { | |
1756 | int exclude_pid = 0; | |
1757 | ||
1758 | if (report) { | |
1759 | atomic_inc(&skb->users); | |
1760 | exclude_pid = pid; | |
1761 | } | |
1762 | ||
1ce85fe4 PNA |
1763 | /* errors reported via destination sk->sk_err, but propagate |
1764 | * delivery errors if NETLINK_BROADCAST_ERROR flag is set */ | |
1765 | err = nlmsg_multicast(sk, skb, exclude_pid, group, flags); | |
d387f6ad TG |
1766 | } |
1767 | ||
1ce85fe4 PNA |
1768 | if (report) { |
1769 | int err2; | |
1770 | ||
1771 | err2 = nlmsg_unicast(sk, skb, pid); | |
1772 | if (!err || err == -ESRCH) | |
1773 | err = err2; | |
1774 | } | |
d387f6ad TG |
1775 | |
1776 | return err; | |
1777 | } | |
6ac552fd | 1778 | EXPORT_SYMBOL(nlmsg_notify); |
d387f6ad | 1779 | |
1da177e4 LT |
1780 | #ifdef CONFIG_PROC_FS |
1781 | struct nl_seq_iter { | |
e372c414 | 1782 | struct seq_net_private p; |
1da177e4 LT |
1783 | int link; |
1784 | int hash_idx; | |
1785 | }; | |
1786 | ||
1787 | static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) | |
1788 | { | |
1789 | struct nl_seq_iter *iter = seq->private; | |
1790 | int i, j; | |
1791 | struct sock *s; | |
1792 | struct hlist_node *node; | |
1793 | loff_t off = 0; | |
1794 | ||
6ac552fd | 1795 | for (i = 0; i < MAX_LINKS; i++) { |
1da177e4 LT |
1796 | struct nl_pid_hash *hash = &nl_table[i].hash; |
1797 | ||
1798 | for (j = 0; j <= hash->mask; j++) { | |
1799 | sk_for_each(s, node, &hash->table[j]) { | |
1218854a | 1800 | if (sock_net(s) != seq_file_net(seq)) |
b4b51029 | 1801 | continue; |
1da177e4 LT |
1802 | if (off == pos) { |
1803 | iter->link = i; | |
1804 | iter->hash_idx = j; | |
1805 | return s; | |
1806 | } | |
1807 | ++off; | |
1808 | } | |
1809 | } | |
1810 | } | |
1811 | return NULL; | |
1812 | } | |
1813 | ||
1814 | static void *netlink_seq_start(struct seq_file *seq, loff_t *pos) | |
9a429c49 | 1815 | __acquires(nl_table_lock) |
1da177e4 LT |
1816 | { |
1817 | read_lock(&nl_table_lock); | |
1818 | return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
1819 | } | |
1820 | ||
1821 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
1822 | { | |
1823 | struct sock *s; | |
1824 | struct nl_seq_iter *iter; | |
1825 | int i, j; | |
1826 | ||
1827 | ++*pos; | |
1828 | ||
1829 | if (v == SEQ_START_TOKEN) | |
1830 | return netlink_seq_socket_idx(seq, 0); | |
746fac4d | 1831 | |
b4b51029 EB |
1832 | iter = seq->private; |
1833 | s = v; | |
1834 | do { | |
1835 | s = sk_next(s); | |
1218854a | 1836 | } while (s && sock_net(s) != seq_file_net(seq)); |
1da177e4 LT |
1837 | if (s) |
1838 | return s; | |
1839 | ||
1da177e4 LT |
1840 | i = iter->link; |
1841 | j = iter->hash_idx + 1; | |
1842 | ||
1843 | do { | |
1844 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1845 | ||
1846 | for (; j <= hash->mask; j++) { | |
1847 | s = sk_head(&hash->table[j]); | |
1218854a | 1848 | while (s && sock_net(s) != seq_file_net(seq)) |
b4b51029 | 1849 | s = sk_next(s); |
1da177e4 LT |
1850 | if (s) { |
1851 | iter->link = i; | |
1852 | iter->hash_idx = j; | |
1853 | return s; | |
1854 | } | |
1855 | } | |
1856 | ||
1857 | j = 0; | |
1858 | } while (++i < MAX_LINKS); | |
1859 | ||
1860 | return NULL; | |
1861 | } | |
1862 | ||
1863 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
9a429c49 | 1864 | __releases(nl_table_lock) |
1da177e4 LT |
1865 | { |
1866 | read_unlock(&nl_table_lock); | |
1867 | } | |
1868 | ||
1869 | ||
1870 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
1871 | { | |
1872 | if (v == SEQ_START_TOKEN) | |
1873 | seq_puts(seq, | |
1874 | "sk Eth Pid Groups " | |
1875 | "Rmem Wmem Dump Locks\n"); | |
1876 | else { | |
1877 | struct sock *s = v; | |
1878 | struct netlink_sock *nlk = nlk_sk(s); | |
1879 | ||
1880 | seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %d\n", | |
1881 | s, | |
1882 | s->sk_protocol, | |
1883 | nlk->pid, | |
513c2500 | 1884 | nlk->groups ? (u32)nlk->groups[0] : 0, |
1da177e4 LT |
1885 | atomic_read(&s->sk_rmem_alloc), |
1886 | atomic_read(&s->sk_wmem_alloc), | |
1887 | nlk->cb, | |
1888 | atomic_read(&s->sk_refcnt) | |
1889 | ); | |
1890 | ||
1891 | } | |
1892 | return 0; | |
1893 | } | |
1894 | ||
56b3d975 | 1895 | static const struct seq_operations netlink_seq_ops = { |
1da177e4 LT |
1896 | .start = netlink_seq_start, |
1897 | .next = netlink_seq_next, | |
1898 | .stop = netlink_seq_stop, | |
1899 | .show = netlink_seq_show, | |
1900 | }; | |
1901 | ||
1902 | ||
1903 | static int netlink_seq_open(struct inode *inode, struct file *file) | |
1904 | { | |
e372c414 DL |
1905 | return seq_open_net(inode, file, &netlink_seq_ops, |
1906 | sizeof(struct nl_seq_iter)); | |
b4b51029 EB |
1907 | } |
1908 | ||
da7071d7 | 1909 | static const struct file_operations netlink_seq_fops = { |
1da177e4 LT |
1910 | .owner = THIS_MODULE, |
1911 | .open = netlink_seq_open, | |
1912 | .read = seq_read, | |
1913 | .llseek = seq_lseek, | |
e372c414 | 1914 | .release = seq_release_net, |
1da177e4 LT |
1915 | }; |
1916 | ||
1917 | #endif | |
1918 | ||
1919 | int netlink_register_notifier(struct notifier_block *nb) | |
1920 | { | |
e041c683 | 1921 | return atomic_notifier_chain_register(&netlink_chain, nb); |
1da177e4 | 1922 | } |
6ac552fd | 1923 | EXPORT_SYMBOL(netlink_register_notifier); |
1da177e4 LT |
1924 | |
1925 | int netlink_unregister_notifier(struct notifier_block *nb) | |
1926 | { | |
e041c683 | 1927 | return atomic_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 | 1928 | } |
6ac552fd | 1929 | EXPORT_SYMBOL(netlink_unregister_notifier); |
746fac4d | 1930 | |
90ddc4f0 | 1931 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
1932 | .family = PF_NETLINK, |
1933 | .owner = THIS_MODULE, | |
1934 | .release = netlink_release, | |
1935 | .bind = netlink_bind, | |
1936 | .connect = netlink_connect, | |
1937 | .socketpair = sock_no_socketpair, | |
1938 | .accept = sock_no_accept, | |
1939 | .getname = netlink_getname, | |
1940 | .poll = datagram_poll, | |
1941 | .ioctl = sock_no_ioctl, | |
1942 | .listen = sock_no_listen, | |
1943 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
1944 | .setsockopt = netlink_setsockopt, |
1945 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
1946 | .sendmsg = netlink_sendmsg, |
1947 | .recvmsg = netlink_recvmsg, | |
1948 | .mmap = sock_no_mmap, | |
1949 | .sendpage = sock_no_sendpage, | |
1950 | }; | |
1951 | ||
1952 | static struct net_proto_family netlink_family_ops = { | |
1953 | .family = PF_NETLINK, | |
1954 | .create = netlink_create, | |
1955 | .owner = THIS_MODULE, /* for consistency 8) */ | |
1956 | }; | |
1957 | ||
4665079c | 1958 | static int __net_init netlink_net_init(struct net *net) |
b4b51029 EB |
1959 | { |
1960 | #ifdef CONFIG_PROC_FS | |
1961 | if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops)) | |
1962 | return -ENOMEM; | |
1963 | #endif | |
1964 | return 0; | |
1965 | } | |
1966 | ||
4665079c | 1967 | static void __net_exit netlink_net_exit(struct net *net) |
b4b51029 EB |
1968 | { |
1969 | #ifdef CONFIG_PROC_FS | |
1970 | proc_net_remove(net, "netlink"); | |
1971 | #endif | |
1972 | } | |
1973 | ||
022cbae6 | 1974 | static struct pernet_operations __net_initdata netlink_net_ops = { |
b4b51029 EB |
1975 | .init = netlink_net_init, |
1976 | .exit = netlink_net_exit, | |
1977 | }; | |
1978 | ||
1da177e4 LT |
1979 | static int __init netlink_proto_init(void) |
1980 | { | |
1981 | struct sk_buff *dummy_skb; | |
1982 | int i; | |
26ff5ddc | 1983 | unsigned long limit; |
1da177e4 LT |
1984 | unsigned int order; |
1985 | int err = proto_register(&netlink_proto, 0); | |
1986 | ||
1987 | if (err != 0) | |
1988 | goto out; | |
1989 | ||
ef047f5e | 1990 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb)); |
1da177e4 | 1991 | |
0da974f4 | 1992 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
1993 | if (!nl_table) |
1994 | goto panic; | |
1da177e4 | 1995 | |
1da177e4 | 1996 | if (num_physpages >= (128 * 1024)) |
26ff5ddc | 1997 | limit = num_physpages >> (21 - PAGE_SHIFT); |
1da177e4 | 1998 | else |
26ff5ddc | 1999 | limit = num_physpages >> (23 - PAGE_SHIFT); |
1da177e4 | 2000 | |
26ff5ddc DC |
2001 | order = get_bitmask_order(limit) - 1 + PAGE_SHIFT; |
2002 | limit = (1UL << order) / sizeof(struct hlist_head); | |
2003 | order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1; | |
1da177e4 LT |
2004 | |
2005 | for (i = 0; i < MAX_LINKS; i++) { | |
2006 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
2007 | ||
ea72912c | 2008 | hash->table = nl_pid_hash_zalloc(1 * sizeof(*hash->table)); |
1da177e4 LT |
2009 | if (!hash->table) { |
2010 | while (i-- > 0) | |
2011 | nl_pid_hash_free(nl_table[i].hash.table, | |
2012 | 1 * sizeof(*hash->table)); | |
2013 | kfree(nl_table); | |
fab2caf6 | 2014 | goto panic; |
1da177e4 | 2015 | } |
1da177e4 LT |
2016 | hash->max_shift = order; |
2017 | hash->shift = 0; | |
2018 | hash->mask = 0; | |
2019 | hash->rehash_time = jiffies; | |
2020 | } | |
2021 | ||
2022 | sock_register(&netlink_family_ops); | |
b4b51029 | 2023 | register_pernet_subsys(&netlink_net_ops); |
746fac4d | 2024 | /* The netlink device handler may be needed early. */ |
1da177e4 LT |
2025 | rtnetlink_init(); |
2026 | out: | |
2027 | return err; | |
fab2caf6 AM |
2028 | panic: |
2029 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
2030 | } |
2031 | ||
1da177e4 | 2032 | core_initcall(netlink_proto_init); |