]>
Commit | Line | Data |
---|---|---|
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 |
77247bbb | 88 | |
1da177e4 LT |
89 | static inline struct netlink_sock *nlk_sk(struct sock *sk) |
90 | { | |
32b21e03 | 91 | return container_of(sk, struct netlink_sock, sk); |
1da177e4 LT |
92 | } |
93 | ||
aed81560 DL |
94 | static inline int netlink_is_kernel(struct sock *sk) |
95 | { | |
96 | return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET; | |
97 | } | |
98 | ||
1da177e4 LT |
99 | struct nl_pid_hash { |
100 | struct hlist_head *table; | |
101 | unsigned long rehash_time; | |
102 | ||
103 | unsigned int mask; | |
104 | unsigned int shift; | |
105 | ||
106 | unsigned int entries; | |
107 | unsigned int max_shift; | |
108 | ||
109 | u32 rnd; | |
110 | }; | |
111 | ||
112 | struct netlink_table { | |
113 | struct nl_pid_hash hash; | |
114 | struct hlist_head mc_list; | |
4277a083 | 115 | unsigned long *listeners; |
1da177e4 | 116 | unsigned int nl_nonroot; |
f7fa9b10 | 117 | unsigned int groups; |
af65bdfc | 118 | struct mutex *cb_mutex; |
77247bbb | 119 | struct module *module; |
ab33a171 | 120 | int registered; |
1da177e4 LT |
121 | }; |
122 | ||
123 | static struct netlink_table *nl_table; | |
124 | ||
125 | static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); | |
126 | ||
127 | static int netlink_dump(struct sock *sk); | |
128 | static void netlink_destroy_callback(struct netlink_callback *cb); | |
129 | ||
130 | static DEFINE_RWLOCK(nl_table_lock); | |
131 | static atomic_t nl_table_users = ATOMIC_INIT(0); | |
132 | ||
e041c683 | 133 | static ATOMIC_NOTIFIER_HEAD(netlink_chain); |
1da177e4 | 134 | |
d629b836 PM |
135 | static u32 netlink_group_mask(u32 group) |
136 | { | |
137 | return group ? 1 << (group - 1) : 0; | |
138 | } | |
139 | ||
1da177e4 LT |
140 | static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid) |
141 | { | |
142 | return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask]; | |
143 | } | |
144 | ||
145 | static void netlink_sock_destruct(struct sock *sk) | |
146 | { | |
3f660d66 HX |
147 | struct netlink_sock *nlk = nlk_sk(sk); |
148 | ||
3f660d66 HX |
149 | if (nlk->cb) { |
150 | if (nlk->cb->done) | |
151 | nlk->cb->done(nlk->cb); | |
152 | netlink_destroy_callback(nlk->cb); | |
153 | } | |
154 | ||
1da177e4 LT |
155 | skb_queue_purge(&sk->sk_receive_queue); |
156 | ||
157 | if (!sock_flag(sk, SOCK_DEAD)) { | |
6ac552fd | 158 | printk(KERN_ERR "Freeing alive netlink socket %p\n", sk); |
1da177e4 LT |
159 | return; |
160 | } | |
547b792c IJ |
161 | |
162 | WARN_ON(atomic_read(&sk->sk_rmem_alloc)); | |
163 | WARN_ON(atomic_read(&sk->sk_wmem_alloc)); | |
164 | WARN_ON(nlk_sk(sk)->groups); | |
1da177e4 LT |
165 | } |
166 | ||
6ac552fd PM |
167 | /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on |
168 | * SMP. Look, when several writers sleep and reader wakes them up, all but one | |
1da177e4 LT |
169 | * immediately hit write lock and grab all the cpus. Exclusive sleep solves |
170 | * this, _but_ remember, it adds useless work on UP machines. | |
171 | */ | |
172 | ||
173 | static void netlink_table_grab(void) | |
9a429c49 | 174 | __acquires(nl_table_lock) |
1da177e4 | 175 | { |
6abd219c | 176 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
177 | |
178 | if (atomic_read(&nl_table_users)) { | |
179 | DECLARE_WAITQUEUE(wait, current); | |
180 | ||
181 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
6ac552fd | 182 | for (;;) { |
1da177e4 LT |
183 | set_current_state(TASK_UNINTERRUPTIBLE); |
184 | if (atomic_read(&nl_table_users) == 0) | |
185 | break; | |
6abd219c | 186 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 187 | schedule(); |
6abd219c | 188 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
189 | } |
190 | ||
191 | __set_current_state(TASK_RUNNING); | |
192 | remove_wait_queue(&nl_table_wait, &wait); | |
193 | } | |
194 | } | |
195 | ||
3f252526 | 196 | static void netlink_table_ungrab(void) |
9a429c49 | 197 | __releases(nl_table_lock) |
1da177e4 | 198 | { |
6abd219c | 199 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
200 | wake_up(&nl_table_wait); |
201 | } | |
202 | ||
6ac552fd | 203 | static inline void |
1da177e4 LT |
204 | netlink_lock_table(void) |
205 | { | |
206 | /* read_lock() synchronizes us to netlink_table_grab */ | |
207 | ||
208 | read_lock(&nl_table_lock); | |
209 | atomic_inc(&nl_table_users); | |
210 | read_unlock(&nl_table_lock); | |
211 | } | |
212 | ||
6ac552fd | 213 | static inline void |
1da177e4 LT |
214 | netlink_unlock_table(void) |
215 | { | |
216 | if (atomic_dec_and_test(&nl_table_users)) | |
217 | wake_up(&nl_table_wait); | |
218 | } | |
219 | ||
6ac552fd PM |
220 | static inline struct sock *netlink_lookup(struct net *net, int protocol, |
221 | u32 pid) | |
1da177e4 LT |
222 | { |
223 | struct nl_pid_hash *hash = &nl_table[protocol].hash; | |
224 | struct hlist_head *head; | |
225 | struct sock *sk; | |
226 | struct hlist_node *node; | |
227 | ||
228 | read_lock(&nl_table_lock); | |
229 | head = nl_pid_hashfn(hash, pid); | |
230 | sk_for_each(sk, node, head) { | |
878628fb | 231 | if (net_eq(sock_net(sk), net) && (nlk_sk(sk)->pid == pid)) { |
1da177e4 LT |
232 | sock_hold(sk); |
233 | goto found; | |
234 | } | |
235 | } | |
236 | sk = NULL; | |
237 | found: | |
238 | read_unlock(&nl_table_lock); | |
239 | return sk; | |
240 | } | |
241 | ||
ea72912c | 242 | static inline struct hlist_head *nl_pid_hash_zalloc(size_t size) |
1da177e4 LT |
243 | { |
244 | if (size <= PAGE_SIZE) | |
ea72912c | 245 | return kzalloc(size, GFP_ATOMIC); |
1da177e4 LT |
246 | else |
247 | return (struct hlist_head *) | |
ea72912c ED |
248 | __get_free_pages(GFP_ATOMIC | __GFP_ZERO, |
249 | get_order(size)); | |
1da177e4 LT |
250 | } |
251 | ||
252 | static inline void nl_pid_hash_free(struct hlist_head *table, size_t size) | |
253 | { | |
254 | if (size <= PAGE_SIZE) | |
255 | kfree(table); | |
256 | else | |
257 | free_pages((unsigned long)table, get_order(size)); | |
258 | } | |
259 | ||
260 | static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow) | |
261 | { | |
262 | unsigned int omask, mask, shift; | |
263 | size_t osize, size; | |
264 | struct hlist_head *otable, *table; | |
265 | int i; | |
266 | ||
267 | omask = mask = hash->mask; | |
268 | osize = size = (mask + 1) * sizeof(*table); | |
269 | shift = hash->shift; | |
270 | ||
271 | if (grow) { | |
272 | if (++shift > hash->max_shift) | |
273 | return 0; | |
274 | mask = mask * 2 + 1; | |
275 | size *= 2; | |
276 | } | |
277 | ||
ea72912c | 278 | table = nl_pid_hash_zalloc(size); |
1da177e4 LT |
279 | if (!table) |
280 | return 0; | |
281 | ||
1da177e4 LT |
282 | otable = hash->table; |
283 | hash->table = table; | |
284 | hash->mask = mask; | |
285 | hash->shift = shift; | |
286 | get_random_bytes(&hash->rnd, sizeof(hash->rnd)); | |
287 | ||
288 | for (i = 0; i <= omask; i++) { | |
289 | struct sock *sk; | |
290 | struct hlist_node *node, *tmp; | |
291 | ||
292 | sk_for_each_safe(sk, node, tmp, &otable[i]) | |
293 | __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid)); | |
294 | } | |
295 | ||
296 | nl_pid_hash_free(otable, osize); | |
297 | hash->rehash_time = jiffies + 10 * 60 * HZ; | |
298 | return 1; | |
299 | } | |
300 | ||
301 | static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len) | |
302 | { | |
303 | int avg = hash->entries >> hash->shift; | |
304 | ||
305 | if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1)) | |
306 | return 1; | |
307 | ||
308 | if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) { | |
309 | nl_pid_hash_rehash(hash, 0); | |
310 | return 1; | |
311 | } | |
312 | ||
313 | return 0; | |
314 | } | |
315 | ||
90ddc4f0 | 316 | static const struct proto_ops netlink_ops; |
1da177e4 | 317 | |
4277a083 PM |
318 | static void |
319 | netlink_update_listeners(struct sock *sk) | |
320 | { | |
321 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
322 | struct hlist_node *node; | |
323 | unsigned long mask; | |
324 | unsigned int i; | |
325 | ||
b4ff4f04 | 326 | for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
4277a083 | 327 | mask = 0; |
b4ff4f04 JB |
328 | sk_for_each_bound(sk, node, &tbl->mc_list) { |
329 | if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) | |
330 | mask |= nlk_sk(sk)->groups[i]; | |
331 | } | |
4277a083 PM |
332 | tbl->listeners[i] = mask; |
333 | } | |
334 | /* this function is only called with the netlink table "grabbed", which | |
335 | * makes sure updates are visible before bind or setsockopt return. */ | |
336 | } | |
337 | ||
b4b51029 | 338 | static int netlink_insert(struct sock *sk, struct net *net, u32 pid) |
1da177e4 LT |
339 | { |
340 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; | |
341 | struct hlist_head *head; | |
342 | int err = -EADDRINUSE; | |
343 | struct sock *osk; | |
344 | struct hlist_node *node; | |
345 | int len; | |
346 | ||
347 | netlink_table_grab(); | |
348 | head = nl_pid_hashfn(hash, pid); | |
349 | len = 0; | |
350 | sk_for_each(osk, node, head) { | |
878628fb | 351 | if (net_eq(sock_net(osk), net) && (nlk_sk(osk)->pid == pid)) |
1da177e4 LT |
352 | break; |
353 | len++; | |
354 | } | |
355 | if (node) | |
356 | goto err; | |
357 | ||
358 | err = -EBUSY; | |
359 | if (nlk_sk(sk)->pid) | |
360 | goto err; | |
361 | ||
362 | err = -ENOMEM; | |
363 | if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX)) | |
364 | goto err; | |
365 | ||
366 | if (len && nl_pid_hash_dilute(hash, len)) | |
367 | head = nl_pid_hashfn(hash, pid); | |
368 | hash->entries++; | |
369 | nlk_sk(sk)->pid = pid; | |
370 | sk_add_node(sk, head); | |
371 | err = 0; | |
372 | ||
373 | err: | |
374 | netlink_table_ungrab(); | |
375 | return err; | |
376 | } | |
377 | ||
378 | static void netlink_remove(struct sock *sk) | |
379 | { | |
380 | netlink_table_grab(); | |
d470e3b4 DM |
381 | if (sk_del_node_init(sk)) |
382 | nl_table[sk->sk_protocol].hash.entries--; | |
f7fa9b10 | 383 | if (nlk_sk(sk)->subscriptions) |
1da177e4 LT |
384 | __sk_del_bind_node(sk); |
385 | netlink_table_ungrab(); | |
386 | } | |
387 | ||
388 | static struct proto netlink_proto = { | |
389 | .name = "NETLINK", | |
390 | .owner = THIS_MODULE, | |
391 | .obj_size = sizeof(struct netlink_sock), | |
392 | }; | |
393 | ||
1b8d7ae4 EB |
394 | static int __netlink_create(struct net *net, struct socket *sock, |
395 | struct mutex *cb_mutex, int protocol) | |
1da177e4 LT |
396 | { |
397 | struct sock *sk; | |
398 | struct netlink_sock *nlk; | |
ab33a171 PM |
399 | |
400 | sock->ops = &netlink_ops; | |
401 | ||
6257ff21 | 402 | sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto); |
ab33a171 PM |
403 | if (!sk) |
404 | return -ENOMEM; | |
405 | ||
406 | sock_init_data(sock, sk); | |
407 | ||
408 | nlk = nlk_sk(sk); | |
ffa4d721 PM |
409 | if (cb_mutex) |
410 | nlk->cb_mutex = cb_mutex; | |
411 | else { | |
412 | nlk->cb_mutex = &nlk->cb_def_mutex; | |
413 | mutex_init(nlk->cb_mutex); | |
414 | } | |
ab33a171 PM |
415 | init_waitqueue_head(&nlk->wait); |
416 | ||
417 | sk->sk_destruct = netlink_sock_destruct; | |
418 | sk->sk_protocol = protocol; | |
419 | return 0; | |
420 | } | |
421 | ||
1b8d7ae4 | 422 | static int netlink_create(struct net *net, struct socket *sock, int protocol) |
ab33a171 PM |
423 | { |
424 | struct module *module = NULL; | |
af65bdfc | 425 | struct mutex *cb_mutex; |
f7fa9b10 | 426 | struct netlink_sock *nlk; |
ab33a171 | 427 | int err = 0; |
1da177e4 LT |
428 | |
429 | sock->state = SS_UNCONNECTED; | |
430 | ||
431 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
432 | return -ESOCKTNOSUPPORT; | |
433 | ||
6ac552fd | 434 | if (protocol < 0 || protocol >= MAX_LINKS) |
1da177e4 LT |
435 | return -EPROTONOSUPPORT; |
436 | ||
77247bbb | 437 | netlink_lock_table(); |
95a5afca | 438 | #ifdef CONFIG_MODULES |
ab33a171 | 439 | if (!nl_table[protocol].registered) { |
77247bbb | 440 | netlink_unlock_table(); |
4fdb3bb7 | 441 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 442 | netlink_lock_table(); |
4fdb3bb7 | 443 | } |
ab33a171 PM |
444 | #endif |
445 | if (nl_table[protocol].registered && | |
446 | try_module_get(nl_table[protocol].module)) | |
447 | module = nl_table[protocol].module; | |
af65bdfc | 448 | cb_mutex = nl_table[protocol].cb_mutex; |
77247bbb | 449 | netlink_unlock_table(); |
4fdb3bb7 | 450 | |
6ac552fd PM |
451 | err = __netlink_create(net, sock, cb_mutex, protocol); |
452 | if (err < 0) | |
f7fa9b10 PM |
453 | goto out_module; |
454 | ||
6f756a8c | 455 | local_bh_disable(); |
c1fd3b94 | 456 | sock_prot_inuse_add(net, &netlink_proto, 1); |
6f756a8c DM |
457 | local_bh_enable(); |
458 | ||
f7fa9b10 | 459 | nlk = nlk_sk(sock->sk); |
f7fa9b10 | 460 | nlk->module = module; |
ab33a171 PM |
461 | out: |
462 | return err; | |
1da177e4 | 463 | |
ab33a171 PM |
464 | out_module: |
465 | module_put(module); | |
466 | goto out; | |
1da177e4 LT |
467 | } |
468 | ||
469 | static int netlink_release(struct socket *sock) | |
470 | { | |
471 | struct sock *sk = sock->sk; | |
472 | struct netlink_sock *nlk; | |
473 | ||
474 | if (!sk) | |
475 | return 0; | |
476 | ||
477 | netlink_remove(sk); | |
ac57b3a9 | 478 | sock_orphan(sk); |
1da177e4 LT |
479 | nlk = nlk_sk(sk); |
480 | ||
3f660d66 HX |
481 | /* |
482 | * OK. Socket is unlinked, any packets that arrive now | |
483 | * will be purged. | |
484 | */ | |
1da177e4 | 485 | |
1da177e4 LT |
486 | sock->sk = NULL; |
487 | wake_up_interruptible_all(&nlk->wait); | |
488 | ||
489 | skb_queue_purge(&sk->sk_write_queue); | |
490 | ||
f7fa9b10 | 491 | if (nlk->pid && !nlk->subscriptions) { |
1da177e4 | 492 | struct netlink_notify n = { |
3b1e0a65 | 493 | .net = sock_net(sk), |
1da177e4 LT |
494 | .protocol = sk->sk_protocol, |
495 | .pid = nlk->pid, | |
496 | }; | |
e041c683 AS |
497 | atomic_notifier_call_chain(&netlink_chain, |
498 | NETLINK_URELEASE, &n); | |
746fac4d | 499 | } |
4fdb3bb7 | 500 | |
5e7c001c | 501 | module_put(nlk->module); |
4fdb3bb7 | 502 | |
4277a083 | 503 | netlink_table_grab(); |
aed81560 | 504 | if (netlink_is_kernel(sk)) { |
869e58f8 DL |
505 | BUG_ON(nl_table[sk->sk_protocol].registered == 0); |
506 | if (--nl_table[sk->sk_protocol].registered == 0) { | |
507 | kfree(nl_table[sk->sk_protocol].listeners); | |
508 | nl_table[sk->sk_protocol].module = NULL; | |
509 | nl_table[sk->sk_protocol].registered = 0; | |
510 | } | |
4277a083 PM |
511 | } else if (nlk->subscriptions) |
512 | netlink_update_listeners(sk); | |
513 | netlink_table_ungrab(); | |
77247bbb | 514 | |
f7fa9b10 PM |
515 | kfree(nlk->groups); |
516 | nlk->groups = NULL; | |
517 | ||
3755810c | 518 | local_bh_disable(); |
c1fd3b94 | 519 | sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); |
3755810c | 520 | local_bh_enable(); |
1da177e4 LT |
521 | sock_put(sk); |
522 | return 0; | |
523 | } | |
524 | ||
525 | static int netlink_autobind(struct socket *sock) | |
526 | { | |
527 | struct sock *sk = sock->sk; | |
3b1e0a65 | 528 | struct net *net = sock_net(sk); |
1da177e4 LT |
529 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; |
530 | struct hlist_head *head; | |
531 | struct sock *osk; | |
532 | struct hlist_node *node; | |
c27bd492 | 533 | s32 pid = current->tgid; |
1da177e4 LT |
534 | int err; |
535 | static s32 rover = -4097; | |
536 | ||
537 | retry: | |
538 | cond_resched(); | |
539 | netlink_table_grab(); | |
540 | head = nl_pid_hashfn(hash, pid); | |
541 | sk_for_each(osk, node, head) { | |
878628fb | 542 | if (!net_eq(sock_net(osk), net)) |
b4b51029 | 543 | continue; |
1da177e4 LT |
544 | if (nlk_sk(osk)->pid == pid) { |
545 | /* Bind collision, search negative pid values. */ | |
546 | pid = rover--; | |
547 | if (rover > -4097) | |
548 | rover = -4097; | |
549 | netlink_table_ungrab(); | |
550 | goto retry; | |
551 | } | |
552 | } | |
553 | netlink_table_ungrab(); | |
554 | ||
b4b51029 | 555 | err = netlink_insert(sk, net, pid); |
1da177e4 LT |
556 | if (err == -EADDRINUSE) |
557 | goto retry; | |
d470e3b4 DM |
558 | |
559 | /* If 2 threads race to autobind, that is fine. */ | |
560 | if (err == -EBUSY) | |
561 | err = 0; | |
562 | ||
563 | return err; | |
1da177e4 LT |
564 | } |
565 | ||
746fac4d YH |
566 | static inline int netlink_capable(struct socket *sock, unsigned int flag) |
567 | { | |
1da177e4 LT |
568 | return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) || |
569 | capable(CAP_NET_ADMIN); | |
746fac4d | 570 | } |
1da177e4 | 571 | |
f7fa9b10 PM |
572 | static void |
573 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
574 | { | |
575 | struct netlink_sock *nlk = nlk_sk(sk); | |
576 | ||
577 | if (nlk->subscriptions && !subscriptions) | |
578 | __sk_del_bind_node(sk); | |
579 | else if (!nlk->subscriptions && subscriptions) | |
580 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
581 | nlk->subscriptions = subscriptions; | |
582 | } | |
583 | ||
b4ff4f04 | 584 | static int netlink_realloc_groups(struct sock *sk) |
513c2500 PM |
585 | { |
586 | struct netlink_sock *nlk = nlk_sk(sk); | |
587 | unsigned int groups; | |
b4ff4f04 | 588 | unsigned long *new_groups; |
513c2500 PM |
589 | int err = 0; |
590 | ||
b4ff4f04 JB |
591 | netlink_table_grab(); |
592 | ||
513c2500 | 593 | groups = nl_table[sk->sk_protocol].groups; |
b4ff4f04 | 594 | if (!nl_table[sk->sk_protocol].registered) { |
513c2500 | 595 | err = -ENOENT; |
b4ff4f04 JB |
596 | goto out_unlock; |
597 | } | |
513c2500 | 598 | |
b4ff4f04 JB |
599 | if (nlk->ngroups >= groups) |
600 | goto out_unlock; | |
513c2500 | 601 | |
b4ff4f04 JB |
602 | new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
603 | if (new_groups == NULL) { | |
604 | err = -ENOMEM; | |
605 | goto out_unlock; | |
606 | } | |
6ac552fd | 607 | memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, |
b4ff4f04 JB |
608 | NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); |
609 | ||
610 | nlk->groups = new_groups; | |
513c2500 | 611 | nlk->ngroups = groups; |
b4ff4f04 JB |
612 | out_unlock: |
613 | netlink_table_ungrab(); | |
614 | return err; | |
513c2500 PM |
615 | } |
616 | ||
6ac552fd PM |
617 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, |
618 | int addr_len) | |
1da177e4 LT |
619 | { |
620 | struct sock *sk = sock->sk; | |
3b1e0a65 | 621 | struct net *net = sock_net(sk); |
1da177e4 LT |
622 | struct netlink_sock *nlk = nlk_sk(sk); |
623 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
624 | int err; | |
746fac4d | 625 | |
1da177e4 LT |
626 | if (nladdr->nl_family != AF_NETLINK) |
627 | return -EINVAL; | |
628 | ||
629 | /* Only superuser is allowed to listen multicasts */ | |
513c2500 PM |
630 | if (nladdr->nl_groups) { |
631 | if (!netlink_capable(sock, NL_NONROOT_RECV)) | |
632 | return -EPERM; | |
b4ff4f04 JB |
633 | err = netlink_realloc_groups(sk); |
634 | if (err) | |
635 | return err; | |
513c2500 | 636 | } |
1da177e4 LT |
637 | |
638 | if (nlk->pid) { | |
639 | if (nladdr->nl_pid != nlk->pid) | |
640 | return -EINVAL; | |
641 | } else { | |
642 | err = nladdr->nl_pid ? | |
b4b51029 | 643 | netlink_insert(sk, net, nladdr->nl_pid) : |
1da177e4 LT |
644 | netlink_autobind(sock); |
645 | if (err) | |
646 | return err; | |
647 | } | |
648 | ||
513c2500 | 649 | if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
1da177e4 LT |
650 | return 0; |
651 | ||
652 | netlink_table_grab(); | |
f7fa9b10 | 653 | netlink_update_subscriptions(sk, nlk->subscriptions + |
746fac4d YH |
654 | hweight32(nladdr->nl_groups) - |
655 | hweight32(nlk->groups[0])); | |
656 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups; | |
4277a083 | 657 | netlink_update_listeners(sk); |
1da177e4 LT |
658 | netlink_table_ungrab(); |
659 | ||
660 | return 0; | |
661 | } | |
662 | ||
663 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
664 | int alen, int flags) | |
665 | { | |
666 | int err = 0; | |
667 | struct sock *sk = sock->sk; | |
668 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 669 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
1da177e4 LT |
670 | |
671 | if (addr->sa_family == AF_UNSPEC) { | |
672 | sk->sk_state = NETLINK_UNCONNECTED; | |
673 | nlk->dst_pid = 0; | |
d629b836 | 674 | nlk->dst_group = 0; |
1da177e4 LT |
675 | return 0; |
676 | } | |
677 | if (addr->sa_family != AF_NETLINK) | |
678 | return -EINVAL; | |
679 | ||
680 | /* Only superuser is allowed to send multicasts */ | |
681 | if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND)) | |
682 | return -EPERM; | |
683 | ||
684 | if (!nlk->pid) | |
685 | err = netlink_autobind(sock); | |
686 | ||
687 | if (err == 0) { | |
688 | sk->sk_state = NETLINK_CONNECTED; | |
689 | nlk->dst_pid = nladdr->nl_pid; | |
d629b836 | 690 | nlk->dst_group = ffs(nladdr->nl_groups); |
1da177e4 LT |
691 | } |
692 | ||
693 | return err; | |
694 | } | |
695 | ||
6ac552fd PM |
696 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, |
697 | int *addr_len, int peer) | |
1da177e4 LT |
698 | { |
699 | struct sock *sk = sock->sk; | |
700 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 701 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
746fac4d | 702 | |
1da177e4 LT |
703 | nladdr->nl_family = AF_NETLINK; |
704 | nladdr->nl_pad = 0; | |
705 | *addr_len = sizeof(*nladdr); | |
706 | ||
707 | if (peer) { | |
708 | nladdr->nl_pid = nlk->dst_pid; | |
d629b836 | 709 | nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
1da177e4 LT |
710 | } else { |
711 | nladdr->nl_pid = nlk->pid; | |
513c2500 | 712 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
1da177e4 LT |
713 | } |
714 | return 0; | |
715 | } | |
716 | ||
717 | static void netlink_overrun(struct sock *sk) | |
718 | { | |
719 | if (!test_and_set_bit(0, &nlk_sk(sk)->state)) { | |
720 | sk->sk_err = ENOBUFS; | |
721 | sk->sk_error_report(sk); | |
722 | } | |
723 | } | |
724 | ||
725 | static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid) | |
726 | { | |
1da177e4 LT |
727 | struct sock *sock; |
728 | struct netlink_sock *nlk; | |
729 | ||
3b1e0a65 | 730 | sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, pid); |
1da177e4 LT |
731 | if (!sock) |
732 | return ERR_PTR(-ECONNREFUSED); | |
733 | ||
734 | /* Don't bother queuing skb if kernel socket has no input function */ | |
735 | nlk = nlk_sk(sock); | |
cd40b7d3 DL |
736 | if (sock->sk_state == NETLINK_CONNECTED && |
737 | nlk->dst_pid != nlk_sk(ssk)->pid) { | |
1da177e4 LT |
738 | sock_put(sock); |
739 | return ERR_PTR(-ECONNREFUSED); | |
740 | } | |
741 | return sock; | |
742 | } | |
743 | ||
744 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
745 | { | |
6db5fc5d | 746 | struct inode *inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
747 | struct sock *sock; |
748 | ||
749 | if (!S_ISSOCK(inode->i_mode)) | |
750 | return ERR_PTR(-ENOTSOCK); | |
751 | ||
752 | sock = SOCKET_I(inode)->sk; | |
753 | if (sock->sk_family != AF_NETLINK) | |
754 | return ERR_PTR(-EINVAL); | |
755 | ||
756 | sock_hold(sock); | |
757 | return sock; | |
758 | } | |
759 | ||
760 | /* | |
761 | * Attach a skb to a netlink socket. | |
762 | * The caller must hold a reference to the destination socket. On error, the | |
763 | * reference is dropped. The skb is not send to the destination, just all | |
764 | * all error checks are performed and memory in the queue is reserved. | |
765 | * Return values: | |
766 | * < 0: error. skb freed, reference to sock dropped. | |
767 | * 0: continue | |
768 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
769 | */ | |
9457afee | 770 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
c3d8d1e3 | 771 | long *timeo, struct sock *ssk) |
1da177e4 LT |
772 | { |
773 | struct netlink_sock *nlk; | |
774 | ||
775 | nlk = nlk_sk(sk); | |
776 | ||
777 | if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
778 | test_bit(0, &nlk->state)) { | |
779 | DECLARE_WAITQUEUE(wait, current); | |
c3d8d1e3 | 780 | if (!*timeo) { |
aed81560 | 781 | if (!ssk || netlink_is_kernel(ssk)) |
1da177e4 LT |
782 | netlink_overrun(sk); |
783 | sock_put(sk); | |
784 | kfree_skb(skb); | |
785 | return -EAGAIN; | |
786 | } | |
787 | ||
788 | __set_current_state(TASK_INTERRUPTIBLE); | |
789 | add_wait_queue(&nlk->wait, &wait); | |
790 | ||
791 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
792 | test_bit(0, &nlk->state)) && | |
793 | !sock_flag(sk, SOCK_DEAD)) | |
c3d8d1e3 | 794 | *timeo = schedule_timeout(*timeo); |
1da177e4 LT |
795 | |
796 | __set_current_state(TASK_RUNNING); | |
797 | remove_wait_queue(&nlk->wait, &wait); | |
798 | sock_put(sk); | |
799 | ||
800 | if (signal_pending(current)) { | |
801 | kfree_skb(skb); | |
c3d8d1e3 | 802 | return sock_intr_errno(*timeo); |
1da177e4 LT |
803 | } |
804 | return 1; | |
805 | } | |
806 | skb_set_owner_r(skb, sk); | |
807 | return 0; | |
808 | } | |
809 | ||
7ee015e0 | 810 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 811 | { |
1da177e4 LT |
812 | int len = skb->len; |
813 | ||
1da177e4 LT |
814 | skb_queue_tail(&sk->sk_receive_queue, skb); |
815 | sk->sk_data_ready(sk, len); | |
816 | sock_put(sk); | |
817 | return len; | |
818 | } | |
819 | ||
820 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
821 | { | |
822 | kfree_skb(skb); | |
823 | sock_put(sk); | |
824 | } | |
825 | ||
37da647d | 826 | static inline struct sk_buff *netlink_trim(struct sk_buff *skb, |
dd0fc66f | 827 | gfp_t allocation) |
1da177e4 LT |
828 | { |
829 | int delta; | |
830 | ||
831 | skb_orphan(skb); | |
832 | ||
4305b541 | 833 | delta = skb->end - skb->tail; |
1da177e4 LT |
834 | if (delta * 2 < skb->truesize) |
835 | return skb; | |
836 | ||
837 | if (skb_shared(skb)) { | |
838 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
839 | if (!nskb) | |
840 | return skb; | |
841 | kfree_skb(skb); | |
842 | skb = nskb; | |
843 | } | |
844 | ||
845 | if (!pskb_expand_head(skb, 0, -delta, allocation)) | |
846 | skb->truesize -= delta; | |
847 | ||
848 | return skb; | |
849 | } | |
850 | ||
cd40b7d3 DL |
851 | static inline void netlink_rcv_wake(struct sock *sk) |
852 | { | |
853 | struct netlink_sock *nlk = nlk_sk(sk); | |
854 | ||
855 | if (skb_queue_empty(&sk->sk_receive_queue)) | |
856 | clear_bit(0, &nlk->state); | |
857 | if (!test_bit(0, &nlk->state)) | |
858 | wake_up_interruptible(&nlk->wait); | |
859 | } | |
860 | ||
861 | static inline int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb) | |
862 | { | |
863 | int ret; | |
864 | struct netlink_sock *nlk = nlk_sk(sk); | |
865 | ||
866 | ret = -ECONNREFUSED; | |
867 | if (nlk->netlink_rcv != NULL) { | |
868 | ret = skb->len; | |
869 | skb_set_owner_r(skb, sk); | |
870 | nlk->netlink_rcv(skb); | |
871 | } | |
872 | kfree_skb(skb); | |
873 | sock_put(sk); | |
874 | return ret; | |
875 | } | |
876 | ||
877 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, | |
878 | u32 pid, int nonblock) | |
1da177e4 LT |
879 | { |
880 | struct sock *sk; | |
881 | int err; | |
882 | long timeo; | |
883 | ||
884 | skb = netlink_trim(skb, gfp_any()); | |
885 | ||
886 | timeo = sock_sndtimeo(ssk, nonblock); | |
887 | retry: | |
888 | sk = netlink_getsockbypid(ssk, pid); | |
889 | if (IS_ERR(sk)) { | |
890 | kfree_skb(skb); | |
891 | return PTR_ERR(sk); | |
892 | } | |
cd40b7d3 DL |
893 | if (netlink_is_kernel(sk)) |
894 | return netlink_unicast_kernel(sk, skb); | |
895 | ||
b1153f29 | 896 | if (sk_filter(sk, skb)) { |
84874607 | 897 | err = skb->len; |
b1153f29 SH |
898 | kfree_skb(skb); |
899 | sock_put(sk); | |
900 | return err; | |
901 | } | |
902 | ||
9457afee | 903 | err = netlink_attachskb(sk, skb, &timeo, ssk); |
1da177e4 LT |
904 | if (err == 1) |
905 | goto retry; | |
906 | if (err) | |
907 | return err; | |
908 | ||
7ee015e0 | 909 | return netlink_sendskb(sk, skb); |
1da177e4 | 910 | } |
6ac552fd | 911 | EXPORT_SYMBOL(netlink_unicast); |
1da177e4 | 912 | |
4277a083 PM |
913 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
914 | { | |
915 | int res = 0; | |
b4ff4f04 | 916 | unsigned long *listeners; |
4277a083 | 917 | |
aed81560 | 918 | BUG_ON(!netlink_is_kernel(sk)); |
b4ff4f04 JB |
919 | |
920 | rcu_read_lock(); | |
921 | listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); | |
922 | ||
4277a083 | 923 | if (group - 1 < nl_table[sk->sk_protocol].groups) |
b4ff4f04 JB |
924 | res = test_bit(group - 1, listeners); |
925 | ||
926 | rcu_read_unlock(); | |
927 | ||
4277a083 PM |
928 | return res; |
929 | } | |
930 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
931 | ||
6ac552fd PM |
932 | static inline int netlink_broadcast_deliver(struct sock *sk, |
933 | struct sk_buff *skb) | |
1da177e4 LT |
934 | { |
935 | struct netlink_sock *nlk = nlk_sk(sk); | |
936 | ||
937 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
938 | !test_bit(0, &nlk->state)) { | |
939 | skb_set_owner_r(skb, sk); | |
940 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
941 | sk->sk_data_ready(sk, skb->len); | |
942 | return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf; | |
943 | } | |
944 | return -1; | |
945 | } | |
946 | ||
947 | struct netlink_broadcast_data { | |
948 | struct sock *exclude_sk; | |
b4b51029 | 949 | struct net *net; |
1da177e4 LT |
950 | u32 pid; |
951 | u32 group; | |
952 | int failure; | |
953 | int congested; | |
954 | int delivered; | |
7d877f3b | 955 | gfp_t allocation; |
1da177e4 LT |
956 | struct sk_buff *skb, *skb2; |
957 | }; | |
958 | ||
959 | static inline int do_one_broadcast(struct sock *sk, | |
960 | struct netlink_broadcast_data *p) | |
961 | { | |
962 | struct netlink_sock *nlk = nlk_sk(sk); | |
963 | int val; | |
964 | ||
965 | if (p->exclude_sk == sk) | |
966 | goto out; | |
967 | ||
f7fa9b10 PM |
968 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
969 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
970 | goto out; |
971 | ||
878628fb | 972 | if (!net_eq(sock_net(sk), p->net)) |
b4b51029 EB |
973 | goto out; |
974 | ||
1da177e4 LT |
975 | if (p->failure) { |
976 | netlink_overrun(sk); | |
977 | goto out; | |
978 | } | |
979 | ||
980 | sock_hold(sk); | |
981 | if (p->skb2 == NULL) { | |
68acc024 | 982 | if (skb_shared(p->skb)) { |
1da177e4 LT |
983 | p->skb2 = skb_clone(p->skb, p->allocation); |
984 | } else { | |
68acc024 TC |
985 | p->skb2 = skb_get(p->skb); |
986 | /* | |
987 | * skb ownership may have been set when | |
988 | * delivered to a previous socket. | |
989 | */ | |
990 | skb_orphan(p->skb2); | |
1da177e4 LT |
991 | } |
992 | } | |
993 | if (p->skb2 == NULL) { | |
994 | netlink_overrun(sk); | |
995 | /* Clone failed. Notify ALL listeners. */ | |
996 | p->failure = 1; | |
b1153f29 SH |
997 | } else if (sk_filter(sk, p->skb2)) { |
998 | kfree_skb(p->skb2); | |
999 | p->skb2 = NULL; | |
1da177e4 LT |
1000 | } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) { |
1001 | netlink_overrun(sk); | |
1002 | } else { | |
1003 | p->congested |= val; | |
1004 | p->delivered = 1; | |
1005 | p->skb2 = NULL; | |
1006 | } | |
1007 | sock_put(sk); | |
1008 | ||
1009 | out: | |
1010 | return 0; | |
1011 | } | |
1012 | ||
1013 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid, | |
dd0fc66f | 1014 | u32 group, gfp_t allocation) |
1da177e4 | 1015 | { |
3b1e0a65 | 1016 | struct net *net = sock_net(ssk); |
1da177e4 LT |
1017 | struct netlink_broadcast_data info; |
1018 | struct hlist_node *node; | |
1019 | struct sock *sk; | |
1020 | ||
1021 | skb = netlink_trim(skb, allocation); | |
1022 | ||
1023 | info.exclude_sk = ssk; | |
b4b51029 | 1024 | info.net = net; |
1da177e4 LT |
1025 | info.pid = pid; |
1026 | info.group = group; | |
1027 | info.failure = 0; | |
1028 | info.congested = 0; | |
1029 | info.delivered = 0; | |
1030 | info.allocation = allocation; | |
1031 | info.skb = skb; | |
1032 | info.skb2 = NULL; | |
1033 | ||
1034 | /* While we sleep in clone, do not allow to change socket list */ | |
1035 | ||
1036 | netlink_lock_table(); | |
1037 | ||
1038 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1039 | do_one_broadcast(sk, &info); | |
1040 | ||
aa1c6a6f TC |
1041 | kfree_skb(skb); |
1042 | ||
1da177e4 LT |
1043 | netlink_unlock_table(); |
1044 | ||
1045 | if (info.skb2) | |
1046 | kfree_skb(info.skb2); | |
1da177e4 LT |
1047 | |
1048 | if (info.delivered) { | |
1049 | if (info.congested && (allocation & __GFP_WAIT)) | |
1050 | yield(); | |
1051 | return 0; | |
1052 | } | |
1053 | if (info.failure) | |
1054 | return -ENOBUFS; | |
1055 | return -ESRCH; | |
1056 | } | |
6ac552fd | 1057 | EXPORT_SYMBOL(netlink_broadcast); |
1da177e4 LT |
1058 | |
1059 | struct netlink_set_err_data { | |
1060 | struct sock *exclude_sk; | |
1061 | u32 pid; | |
1062 | u32 group; | |
1063 | int code; | |
1064 | }; | |
1065 | ||
1066 | static inline int do_one_set_err(struct sock *sk, | |
1067 | struct netlink_set_err_data *p) | |
1068 | { | |
1069 | struct netlink_sock *nlk = nlk_sk(sk); | |
1070 | ||
1071 | if (sk == p->exclude_sk) | |
1072 | goto out; | |
1073 | ||
3b1e0a65 | 1074 | if (sock_net(sk) != sock_net(p->exclude_sk)) |
b4b51029 EB |
1075 | goto out; |
1076 | ||
f7fa9b10 PM |
1077 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
1078 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
1079 | goto out; |
1080 | ||
1081 | sk->sk_err = p->code; | |
1082 | sk->sk_error_report(sk); | |
1083 | out: | |
1084 | return 0; | |
1085 | } | |
1086 | ||
1087 | void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) | |
1088 | { | |
1089 | struct netlink_set_err_data info; | |
1090 | struct hlist_node *node; | |
1091 | struct sock *sk; | |
1092 | ||
1093 | info.exclude_sk = ssk; | |
1094 | info.pid = pid; | |
1095 | info.group = group; | |
1096 | info.code = code; | |
1097 | ||
1098 | read_lock(&nl_table_lock); | |
1099 | ||
1100 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1101 | do_one_set_err(sk, &info); | |
1102 | ||
1103 | read_unlock(&nl_table_lock); | |
1104 | } | |
1105 | ||
84659eb5 JB |
1106 | /* must be called with netlink table grabbed */ |
1107 | static void netlink_update_socket_mc(struct netlink_sock *nlk, | |
1108 | unsigned int group, | |
1109 | int is_new) | |
1110 | { | |
1111 | int old, new = !!is_new, subscriptions; | |
1112 | ||
1113 | old = test_bit(group - 1, nlk->groups); | |
1114 | subscriptions = nlk->subscriptions - old + new; | |
1115 | if (new) | |
1116 | __set_bit(group - 1, nlk->groups); | |
1117 | else | |
1118 | __clear_bit(group - 1, nlk->groups); | |
1119 | netlink_update_subscriptions(&nlk->sk, subscriptions); | |
1120 | netlink_update_listeners(&nlk->sk); | |
1121 | } | |
1122 | ||
9a4595bc | 1123 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
746fac4d | 1124 | char __user *optval, int optlen) |
9a4595bc PM |
1125 | { |
1126 | struct sock *sk = sock->sk; | |
1127 | struct netlink_sock *nlk = nlk_sk(sk); | |
eb496534 JB |
1128 | unsigned int val = 0; |
1129 | int err; | |
9a4595bc PM |
1130 | |
1131 | if (level != SOL_NETLINK) | |
1132 | return -ENOPROTOOPT; | |
1133 | ||
1134 | if (optlen >= sizeof(int) && | |
eb496534 | 1135 | get_user(val, (unsigned int __user *)optval)) |
9a4595bc PM |
1136 | return -EFAULT; |
1137 | ||
1138 | switch (optname) { | |
1139 | case NETLINK_PKTINFO: | |
1140 | if (val) | |
1141 | nlk->flags |= NETLINK_RECV_PKTINFO; | |
1142 | else | |
1143 | nlk->flags &= ~NETLINK_RECV_PKTINFO; | |
1144 | err = 0; | |
1145 | break; | |
1146 | case NETLINK_ADD_MEMBERSHIP: | |
1147 | case NETLINK_DROP_MEMBERSHIP: { | |
9a4595bc PM |
1148 | if (!netlink_capable(sock, NL_NONROOT_RECV)) |
1149 | return -EPERM; | |
b4ff4f04 JB |
1150 | err = netlink_realloc_groups(sk); |
1151 | if (err) | |
1152 | return err; | |
9a4595bc PM |
1153 | if (!val || val - 1 >= nlk->ngroups) |
1154 | return -EINVAL; | |
1155 | netlink_table_grab(); | |
84659eb5 JB |
1156 | netlink_update_socket_mc(nlk, val, |
1157 | optname == NETLINK_ADD_MEMBERSHIP); | |
9a4595bc PM |
1158 | netlink_table_ungrab(); |
1159 | err = 0; | |
1160 | break; | |
1161 | } | |
1162 | default: | |
1163 | err = -ENOPROTOOPT; | |
1164 | } | |
1165 | return err; | |
1166 | } | |
1167 | ||
1168 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
746fac4d | 1169 | char __user *optval, int __user *optlen) |
9a4595bc PM |
1170 | { |
1171 | struct sock *sk = sock->sk; | |
1172 | struct netlink_sock *nlk = nlk_sk(sk); | |
1173 | int len, val, err; | |
1174 | ||
1175 | if (level != SOL_NETLINK) | |
1176 | return -ENOPROTOOPT; | |
1177 | ||
1178 | if (get_user(len, optlen)) | |
1179 | return -EFAULT; | |
1180 | if (len < 0) | |
1181 | return -EINVAL; | |
1182 | ||
1183 | switch (optname) { | |
1184 | case NETLINK_PKTINFO: | |
1185 | if (len < sizeof(int)) | |
1186 | return -EINVAL; | |
1187 | len = sizeof(int); | |
1188 | val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0; | |
a27b58fe HC |
1189 | if (put_user(len, optlen) || |
1190 | put_user(val, optval)) | |
1191 | return -EFAULT; | |
9a4595bc PM |
1192 | err = 0; |
1193 | break; | |
1194 | default: | |
1195 | err = -ENOPROTOOPT; | |
1196 | } | |
1197 | return err; | |
1198 | } | |
1199 | ||
1200 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
1201 | { | |
1202 | struct nl_pktinfo info; | |
1203 | ||
1204 | info.group = NETLINK_CB(skb).dst_group; | |
1205 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
1206 | } | |
1207 | ||
1da177e4 LT |
1208 | static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, |
1209 | struct msghdr *msg, size_t len) | |
1210 | { | |
1211 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1212 | struct sock *sk = sock->sk; | |
1213 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 1214 | struct sockaddr_nl *addr = msg->msg_name; |
1da177e4 | 1215 | u32 dst_pid; |
d629b836 | 1216 | u32 dst_group; |
1da177e4 LT |
1217 | struct sk_buff *skb; |
1218 | int err; | |
1219 | struct scm_cookie scm; | |
1220 | ||
1221 | if (msg->msg_flags&MSG_OOB) | |
1222 | return -EOPNOTSUPP; | |
1223 | ||
1224 | if (NULL == siocb->scm) | |
1225 | siocb->scm = &scm; | |
1226 | err = scm_send(sock, msg, siocb->scm); | |
1227 | if (err < 0) | |
1228 | return err; | |
1229 | ||
1230 | if (msg->msg_namelen) { | |
1231 | if (addr->nl_family != AF_NETLINK) | |
1232 | return -EINVAL; | |
1233 | dst_pid = addr->nl_pid; | |
d629b836 PM |
1234 | dst_group = ffs(addr->nl_groups); |
1235 | if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND)) | |
1da177e4 LT |
1236 | return -EPERM; |
1237 | } else { | |
1238 | dst_pid = nlk->dst_pid; | |
d629b836 | 1239 | dst_group = nlk->dst_group; |
1da177e4 LT |
1240 | } |
1241 | ||
1242 | if (!nlk->pid) { | |
1243 | err = netlink_autobind(sock); | |
1244 | if (err) | |
1245 | goto out; | |
1246 | } | |
1247 | ||
1248 | err = -EMSGSIZE; | |
1249 | if (len > sk->sk_sndbuf - 32) | |
1250 | goto out; | |
1251 | err = -ENOBUFS; | |
339bf98f | 1252 | skb = alloc_skb(len, GFP_KERNEL); |
6ac552fd | 1253 | if (skb == NULL) |
1da177e4 LT |
1254 | goto out; |
1255 | ||
1256 | NETLINK_CB(skb).pid = nlk->pid; | |
d629b836 | 1257 | NETLINK_CB(skb).dst_group = dst_group; |
0c11b942 | 1258 | NETLINK_CB(skb).loginuid = audit_get_loginuid(current); |
2532386f | 1259 | NETLINK_CB(skb).sessionid = audit_get_sessionid(current); |
0ce784ca | 1260 | security_task_getsecid(current, &(NETLINK_CB(skb).sid)); |
1da177e4 LT |
1261 | memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); |
1262 | ||
1263 | /* What can I do? Netlink is asynchronous, so that | |
1264 | we will have to save current capabilities to | |
1265 | check them, when this message will be delivered | |
1266 | to corresponding kernel module. --ANK (980802) | |
1267 | */ | |
1268 | ||
1269 | err = -EFAULT; | |
6ac552fd | 1270 | if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) { |
1da177e4 LT |
1271 | kfree_skb(skb); |
1272 | goto out; | |
1273 | } | |
1274 | ||
1275 | err = security_netlink_send(sk, skb); | |
1276 | if (err) { | |
1277 | kfree_skb(skb); | |
1278 | goto out; | |
1279 | } | |
1280 | ||
d629b836 | 1281 | if (dst_group) { |
1da177e4 | 1282 | atomic_inc(&skb->users); |
d629b836 | 1283 | netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL); |
1da177e4 LT |
1284 | } |
1285 | err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT); | |
1286 | ||
1287 | out: | |
1288 | return err; | |
1289 | } | |
1290 | ||
1291 | static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, | |
1292 | struct msghdr *msg, size_t len, | |
1293 | int flags) | |
1294 | { | |
1295 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1296 | struct scm_cookie scm; | |
1297 | struct sock *sk = sock->sk; | |
1298 | struct netlink_sock *nlk = nlk_sk(sk); | |
1299 | int noblock = flags&MSG_DONTWAIT; | |
1300 | size_t copied; | |
1301 | struct sk_buff *skb; | |
1302 | int err; | |
1303 | ||
1304 | if (flags&MSG_OOB) | |
1305 | return -EOPNOTSUPP; | |
1306 | ||
1307 | copied = 0; | |
1308 | ||
6ac552fd PM |
1309 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
1310 | if (skb == NULL) | |
1da177e4 LT |
1311 | goto out; |
1312 | ||
1313 | msg->msg_namelen = 0; | |
1314 | ||
1315 | copied = skb->len; | |
1316 | if (len < copied) { | |
1317 | msg->msg_flags |= MSG_TRUNC; | |
1318 | copied = len; | |
1319 | } | |
1320 | ||
badff6d0 | 1321 | skb_reset_transport_header(skb); |
1da177e4 LT |
1322 | err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); |
1323 | ||
1324 | if (msg->msg_name) { | |
6ac552fd | 1325 | struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name; |
1da177e4 LT |
1326 | addr->nl_family = AF_NETLINK; |
1327 | addr->nl_pad = 0; | |
1328 | addr->nl_pid = NETLINK_CB(skb).pid; | |
d629b836 | 1329 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
1330 | msg->msg_namelen = sizeof(*addr); |
1331 | } | |
1332 | ||
cc9a06cd PM |
1333 | if (nlk->flags & NETLINK_RECV_PKTINFO) |
1334 | netlink_cmsg_recv_pktinfo(msg, skb); | |
1335 | ||
1da177e4 LT |
1336 | if (NULL == siocb->scm) { |
1337 | memset(&scm, 0, sizeof(scm)); | |
1338 | siocb->scm = &scm; | |
1339 | } | |
1340 | siocb->scm->creds = *NETLINK_CREDS(skb); | |
188ccb55 PM |
1341 | if (flags & MSG_TRUNC) |
1342 | copied = skb->len; | |
1da177e4 LT |
1343 | skb_free_datagram(sk, skb); |
1344 | ||
1345 | if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) | |
1346 | netlink_dump(sk); | |
1347 | ||
1348 | scm_recv(sock, msg, siocb->scm, flags); | |
1da177e4 LT |
1349 | out: |
1350 | netlink_rcv_wake(sk); | |
1351 | return err ? : copied; | |
1352 | } | |
1353 | ||
1354 | static void netlink_data_ready(struct sock *sk, int len) | |
1355 | { | |
cd40b7d3 | 1356 | BUG(); |
1da177e4 LT |
1357 | } |
1358 | ||
1359 | /* | |
746fac4d | 1360 | * We export these functions to other modules. They provide a |
1da177e4 LT |
1361 | * complete set of kernel non-blocking support for message |
1362 | * queueing. | |
1363 | */ | |
1364 | ||
1365 | struct sock * | |
b4b51029 | 1366 | netlink_kernel_create(struct net *net, int unit, unsigned int groups, |
cd40b7d3 | 1367 | void (*input)(struct sk_buff *skb), |
af65bdfc | 1368 | struct mutex *cb_mutex, struct module *module) |
1da177e4 LT |
1369 | { |
1370 | struct socket *sock; | |
1371 | struct sock *sk; | |
77247bbb | 1372 | struct netlink_sock *nlk; |
4277a083 | 1373 | unsigned long *listeners = NULL; |
1da177e4 | 1374 | |
fab2caf6 | 1375 | BUG_ON(!nl_table); |
1da177e4 | 1376 | |
6ac552fd | 1377 | if (unit < 0 || unit >= MAX_LINKS) |
1da177e4 LT |
1378 | return NULL; |
1379 | ||
1380 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
1381 | return NULL; | |
1382 | ||
23fe1866 PE |
1383 | /* |
1384 | * We have to just have a reference on the net from sk, but don't | |
1385 | * get_net it. Besides, we cannot get and then put the net here. | |
1386 | * So we create one inside init_net and the move it to net. | |
1387 | */ | |
1388 | ||
1389 | if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0) | |
1390 | goto out_sock_release_nosk; | |
1391 | ||
1392 | sk = sock->sk; | |
edf02087 | 1393 | sk_change_net(sk, net); |
4fdb3bb7 | 1394 | |
4277a083 PM |
1395 | if (groups < 32) |
1396 | groups = 32; | |
1397 | ||
1398 | listeners = kzalloc(NLGRPSZ(groups), GFP_KERNEL); | |
1399 | if (!listeners) | |
1400 | goto out_sock_release; | |
1401 | ||
1da177e4 LT |
1402 | sk->sk_data_ready = netlink_data_ready; |
1403 | if (input) | |
cd40b7d3 | 1404 | nlk_sk(sk)->netlink_rcv = input; |
1da177e4 | 1405 | |
b4b51029 | 1406 | if (netlink_insert(sk, net, 0)) |
77247bbb | 1407 | goto out_sock_release; |
4fdb3bb7 | 1408 | |
77247bbb PM |
1409 | nlk = nlk_sk(sk); |
1410 | nlk->flags |= NETLINK_KERNEL_SOCKET; | |
4fdb3bb7 | 1411 | |
4fdb3bb7 | 1412 | netlink_table_grab(); |
b4b51029 EB |
1413 | if (!nl_table[unit].registered) { |
1414 | nl_table[unit].groups = groups; | |
1415 | nl_table[unit].listeners = listeners; | |
1416 | nl_table[unit].cb_mutex = cb_mutex; | |
1417 | nl_table[unit].module = module; | |
1418 | nl_table[unit].registered = 1; | |
f937f1f4 JJ |
1419 | } else { |
1420 | kfree(listeners); | |
869e58f8 | 1421 | nl_table[unit].registered++; |
b4b51029 | 1422 | } |
4fdb3bb7 | 1423 | netlink_table_ungrab(); |
77247bbb PM |
1424 | return sk; |
1425 | ||
4fdb3bb7 | 1426 | out_sock_release: |
4277a083 | 1427 | kfree(listeners); |
9dfbec1f | 1428 | netlink_kernel_release(sk); |
23fe1866 PE |
1429 | return NULL; |
1430 | ||
1431 | out_sock_release_nosk: | |
4fdb3bb7 | 1432 | sock_release(sock); |
77247bbb | 1433 | return NULL; |
1da177e4 | 1434 | } |
6ac552fd | 1435 | EXPORT_SYMBOL(netlink_kernel_create); |
1da177e4 | 1436 | |
b7c6ba6e DL |
1437 | |
1438 | void | |
1439 | netlink_kernel_release(struct sock *sk) | |
1440 | { | |
edf02087 | 1441 | sk_release_kernel(sk); |
b7c6ba6e DL |
1442 | } |
1443 | EXPORT_SYMBOL(netlink_kernel_release); | |
1444 | ||
1445 | ||
b4ff4f04 JB |
1446 | /** |
1447 | * netlink_change_ngroups - change number of multicast groups | |
1448 | * | |
1449 | * This changes the number of multicast groups that are available | |
1450 | * on a certain netlink family. Note that it is not possible to | |
84659eb5 JB |
1451 | * change the number of groups to below 32. Also note that it does |
1452 | * not implicitly call netlink_clear_multicast_users() when the | |
1453 | * number of groups is reduced. | |
b4ff4f04 JB |
1454 | * |
1455 | * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). | |
1456 | * @groups: The new number of groups. | |
1457 | */ | |
1458 | int netlink_change_ngroups(struct sock *sk, unsigned int groups) | |
1459 | { | |
1460 | unsigned long *listeners, *old = NULL; | |
1461 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
1462 | int err = 0; | |
1463 | ||
1464 | if (groups < 32) | |
1465 | groups = 32; | |
1466 | ||
1467 | netlink_table_grab(); | |
1468 | if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { | |
1469 | listeners = kzalloc(NLGRPSZ(groups), GFP_ATOMIC); | |
1470 | if (!listeners) { | |
1471 | err = -ENOMEM; | |
1472 | goto out_ungrab; | |
1473 | } | |
1474 | old = tbl->listeners; | |
1475 | memcpy(listeners, old, NLGRPSZ(tbl->groups)); | |
1476 | rcu_assign_pointer(tbl->listeners, listeners); | |
1477 | } | |
1478 | tbl->groups = groups; | |
1479 | ||
1480 | out_ungrab: | |
1481 | netlink_table_ungrab(); | |
1482 | synchronize_rcu(); | |
1483 | kfree(old); | |
1484 | return err; | |
1485 | } | |
1486 | EXPORT_SYMBOL(netlink_change_ngroups); | |
1487 | ||
84659eb5 JB |
1488 | /** |
1489 | * netlink_clear_multicast_users - kick off multicast listeners | |
1490 | * | |
1491 | * This function removes all listeners from the given group. | |
1492 | * @ksk: The kernel netlink socket, as returned by | |
1493 | * netlink_kernel_create(). | |
1494 | * @group: The multicast group to clear. | |
1495 | */ | |
1496 | void netlink_clear_multicast_users(struct sock *ksk, unsigned int group) | |
1497 | { | |
1498 | struct sock *sk; | |
1499 | struct hlist_node *node; | |
1500 | struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; | |
1501 | ||
1502 | netlink_table_grab(); | |
1503 | ||
1504 | sk_for_each_bound(sk, node, &tbl->mc_list) | |
1505 | netlink_update_socket_mc(nlk_sk(sk), group, 0); | |
1506 | ||
1507 | netlink_table_ungrab(); | |
1508 | } | |
1509 | EXPORT_SYMBOL(netlink_clear_multicast_users); | |
1510 | ||
1da177e4 | 1511 | void netlink_set_nonroot(int protocol, unsigned int flags) |
746fac4d YH |
1512 | { |
1513 | if ((unsigned int)protocol < MAX_LINKS) | |
1da177e4 | 1514 | nl_table[protocol].nl_nonroot = flags; |
746fac4d | 1515 | } |
6ac552fd | 1516 | EXPORT_SYMBOL(netlink_set_nonroot); |
1da177e4 LT |
1517 | |
1518 | static void netlink_destroy_callback(struct netlink_callback *cb) | |
1519 | { | |
1520 | if (cb->skb) | |
1521 | kfree_skb(cb->skb); | |
1522 | kfree(cb); | |
1523 | } | |
1524 | ||
1525 | /* | |
1526 | * It looks a bit ugly. | |
1527 | * It would be better to create kernel thread. | |
1528 | */ | |
1529 | ||
1530 | static int netlink_dump(struct sock *sk) | |
1531 | { | |
1532 | struct netlink_sock *nlk = nlk_sk(sk); | |
1533 | struct netlink_callback *cb; | |
1534 | struct sk_buff *skb; | |
1535 | struct nlmsghdr *nlh; | |
bf8b79e4 | 1536 | int len, err = -ENOBUFS; |
746fac4d | 1537 | |
1da177e4 LT |
1538 | skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL); |
1539 | if (!skb) | |
bf8b79e4 | 1540 | goto errout; |
1da177e4 | 1541 | |
af65bdfc | 1542 | mutex_lock(nlk->cb_mutex); |
1da177e4 LT |
1543 | |
1544 | cb = nlk->cb; | |
1545 | if (cb == NULL) { | |
bf8b79e4 TG |
1546 | err = -EINVAL; |
1547 | goto errout_skb; | |
1da177e4 LT |
1548 | } |
1549 | ||
1550 | len = cb->dump(skb, cb); | |
1551 | ||
1552 | if (len > 0) { | |
af65bdfc | 1553 | mutex_unlock(nlk->cb_mutex); |
b1153f29 SH |
1554 | |
1555 | if (sk_filter(sk, skb)) | |
1556 | kfree_skb(skb); | |
1557 | else { | |
1558 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
1559 | sk->sk_data_ready(sk, skb->len); | |
1560 | } | |
1da177e4 LT |
1561 | return 0; |
1562 | } | |
1563 | ||
bf8b79e4 TG |
1564 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); |
1565 | if (!nlh) | |
1566 | goto errout_skb; | |
1567 | ||
1568 | memcpy(nlmsg_data(nlh), &len, sizeof(len)); | |
1569 | ||
b1153f29 SH |
1570 | if (sk_filter(sk, skb)) |
1571 | kfree_skb(skb); | |
1572 | else { | |
1573 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
1574 | sk->sk_data_ready(sk, skb->len); | |
1575 | } | |
1da177e4 | 1576 | |
a8f74b22 TG |
1577 | if (cb->done) |
1578 | cb->done(cb); | |
1da177e4 | 1579 | nlk->cb = NULL; |
af65bdfc | 1580 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1581 | |
1582 | netlink_destroy_callback(cb); | |
1da177e4 | 1583 | return 0; |
1797754e | 1584 | |
bf8b79e4 | 1585 | errout_skb: |
af65bdfc | 1586 | mutex_unlock(nlk->cb_mutex); |
bf8b79e4 TG |
1587 | kfree_skb(skb); |
1588 | errout: | |
1589 | return err; | |
1da177e4 LT |
1590 | } |
1591 | ||
1592 | int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, | |
1593 | struct nlmsghdr *nlh, | |
6ac552fd PM |
1594 | int (*dump)(struct sk_buff *skb, |
1595 | struct netlink_callback *), | |
1596 | int (*done)(struct netlink_callback *)) | |
1da177e4 LT |
1597 | { |
1598 | struct netlink_callback *cb; | |
1599 | struct sock *sk; | |
1600 | struct netlink_sock *nlk; | |
1601 | ||
0da974f4 | 1602 | cb = kzalloc(sizeof(*cb), GFP_KERNEL); |
1da177e4 LT |
1603 | if (cb == NULL) |
1604 | return -ENOBUFS; | |
1605 | ||
1da177e4 LT |
1606 | cb->dump = dump; |
1607 | cb->done = done; | |
1608 | cb->nlh = nlh; | |
1609 | atomic_inc(&skb->users); | |
1610 | cb->skb = skb; | |
1611 | ||
3b1e0a65 | 1612 | sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).pid); |
1da177e4 LT |
1613 | if (sk == NULL) { |
1614 | netlink_destroy_callback(cb); | |
1615 | return -ECONNREFUSED; | |
1616 | } | |
1617 | nlk = nlk_sk(sk); | |
3f660d66 | 1618 | /* A dump is in progress... */ |
af65bdfc | 1619 | mutex_lock(nlk->cb_mutex); |
3f660d66 | 1620 | if (nlk->cb) { |
af65bdfc | 1621 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1622 | netlink_destroy_callback(cb); |
1623 | sock_put(sk); | |
1624 | return -EBUSY; | |
1625 | } | |
1626 | nlk->cb = cb; | |
af65bdfc | 1627 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1628 | |
1629 | netlink_dump(sk); | |
1630 | sock_put(sk); | |
5c58298c DL |
1631 | |
1632 | /* We successfully started a dump, by returning -EINTR we | |
1633 | * signal not to send ACK even if it was requested. | |
1634 | */ | |
1635 | return -EINTR; | |
1da177e4 | 1636 | } |
6ac552fd | 1637 | EXPORT_SYMBOL(netlink_dump_start); |
1da177e4 LT |
1638 | |
1639 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) | |
1640 | { | |
1641 | struct sk_buff *skb; | |
1642 | struct nlmsghdr *rep; | |
1643 | struct nlmsgerr *errmsg; | |
339bf98f | 1644 | size_t payload = sizeof(*errmsg); |
1da177e4 | 1645 | |
339bf98f TG |
1646 | /* error messages get the original request appened */ |
1647 | if (err) | |
1648 | payload += nlmsg_len(nlh); | |
1da177e4 | 1649 | |
339bf98f | 1650 | skb = nlmsg_new(payload, GFP_KERNEL); |
1da177e4 LT |
1651 | if (!skb) { |
1652 | struct sock *sk; | |
1653 | ||
3b1e0a65 | 1654 | sk = netlink_lookup(sock_net(in_skb->sk), |
b4b51029 | 1655 | in_skb->sk->sk_protocol, |
1da177e4 LT |
1656 | NETLINK_CB(in_skb).pid); |
1657 | if (sk) { | |
1658 | sk->sk_err = ENOBUFS; | |
1659 | sk->sk_error_report(sk); | |
1660 | sock_put(sk); | |
1661 | } | |
1662 | return; | |
1663 | } | |
1664 | ||
1665 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, | |
1797754e | 1666 | NLMSG_ERROR, sizeof(struct nlmsgerr), 0); |
bf8b79e4 | 1667 | errmsg = nlmsg_data(rep); |
1da177e4 | 1668 | errmsg->error = err; |
bf8b79e4 | 1669 | memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh)); |
1da177e4 LT |
1670 | netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT); |
1671 | } | |
6ac552fd | 1672 | EXPORT_SYMBOL(netlink_ack); |
1da177e4 | 1673 | |
cd40b7d3 | 1674 | int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
1d00a4eb | 1675 | struct nlmsghdr *)) |
82ace47a | 1676 | { |
82ace47a TG |
1677 | struct nlmsghdr *nlh; |
1678 | int err; | |
1679 | ||
1680 | while (skb->len >= nlmsg_total_size(0)) { | |
cd40b7d3 DL |
1681 | int msglen; |
1682 | ||
b529ccf2 | 1683 | nlh = nlmsg_hdr(skb); |
d35b6856 | 1684 | err = 0; |
82ace47a | 1685 | |
ad8e4b75 | 1686 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
1687 | return 0; |
1688 | ||
d35b6856 TG |
1689 | /* Only requests are handled by the kernel */ |
1690 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | |
5c58298c | 1691 | goto ack; |
45e7ae7f TG |
1692 | |
1693 | /* Skip control messages */ | |
1694 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | |
5c58298c | 1695 | goto ack; |
d35b6856 | 1696 | |
1d00a4eb | 1697 | err = cb(skb, nlh); |
5c58298c DL |
1698 | if (err == -EINTR) |
1699 | goto skip; | |
1700 | ||
1701 | ack: | |
d35b6856 | 1702 | if (nlh->nlmsg_flags & NLM_F_ACK || err) |
82ace47a | 1703 | netlink_ack(skb, nlh, err); |
82ace47a | 1704 | |
5c58298c | 1705 | skip: |
6ac552fd | 1706 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
cd40b7d3 DL |
1707 | if (msglen > skb->len) |
1708 | msglen = skb->len; | |
1709 | skb_pull(skb, msglen); | |
82ace47a TG |
1710 | } |
1711 | ||
1712 | return 0; | |
1713 | } | |
6ac552fd | 1714 | EXPORT_SYMBOL(netlink_rcv_skb); |
82ace47a | 1715 | |
d387f6ad TG |
1716 | /** |
1717 | * nlmsg_notify - send a notification netlink message | |
1718 | * @sk: netlink socket to use | |
1719 | * @skb: notification message | |
1720 | * @pid: destination netlink pid for reports or 0 | |
1721 | * @group: destination multicast group or 0 | |
1722 | * @report: 1 to report back, 0 to disable | |
1723 | * @flags: allocation flags | |
1724 | */ | |
1725 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid, | |
1726 | unsigned int group, int report, gfp_t flags) | |
1727 | { | |
1728 | int err = 0; | |
1729 | ||
1730 | if (group) { | |
1731 | int exclude_pid = 0; | |
1732 | ||
1733 | if (report) { | |
1734 | atomic_inc(&skb->users); | |
1735 | exclude_pid = pid; | |
1736 | } | |
1737 | ||
1738 | /* errors reported via destination sk->sk_err */ | |
1739 | nlmsg_multicast(sk, skb, exclude_pid, group, flags); | |
1740 | } | |
1741 | ||
1742 | if (report) | |
1743 | err = nlmsg_unicast(sk, skb, pid); | |
1744 | ||
1745 | return err; | |
1746 | } | |
6ac552fd | 1747 | EXPORT_SYMBOL(nlmsg_notify); |
d387f6ad | 1748 | |
1da177e4 LT |
1749 | #ifdef CONFIG_PROC_FS |
1750 | struct nl_seq_iter { | |
e372c414 | 1751 | struct seq_net_private p; |
1da177e4 LT |
1752 | int link; |
1753 | int hash_idx; | |
1754 | }; | |
1755 | ||
1756 | static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) | |
1757 | { | |
1758 | struct nl_seq_iter *iter = seq->private; | |
1759 | int i, j; | |
1760 | struct sock *s; | |
1761 | struct hlist_node *node; | |
1762 | loff_t off = 0; | |
1763 | ||
6ac552fd | 1764 | for (i = 0; i < MAX_LINKS; i++) { |
1da177e4 LT |
1765 | struct nl_pid_hash *hash = &nl_table[i].hash; |
1766 | ||
1767 | for (j = 0; j <= hash->mask; j++) { | |
1768 | sk_for_each(s, node, &hash->table[j]) { | |
1218854a | 1769 | if (sock_net(s) != seq_file_net(seq)) |
b4b51029 | 1770 | continue; |
1da177e4 LT |
1771 | if (off == pos) { |
1772 | iter->link = i; | |
1773 | iter->hash_idx = j; | |
1774 | return s; | |
1775 | } | |
1776 | ++off; | |
1777 | } | |
1778 | } | |
1779 | } | |
1780 | return NULL; | |
1781 | } | |
1782 | ||
1783 | static void *netlink_seq_start(struct seq_file *seq, loff_t *pos) | |
9a429c49 | 1784 | __acquires(nl_table_lock) |
1da177e4 LT |
1785 | { |
1786 | read_lock(&nl_table_lock); | |
1787 | return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
1788 | } | |
1789 | ||
1790 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
1791 | { | |
1792 | struct sock *s; | |
1793 | struct nl_seq_iter *iter; | |
1794 | int i, j; | |
1795 | ||
1796 | ++*pos; | |
1797 | ||
1798 | if (v == SEQ_START_TOKEN) | |
1799 | return netlink_seq_socket_idx(seq, 0); | |
746fac4d | 1800 | |
b4b51029 EB |
1801 | iter = seq->private; |
1802 | s = v; | |
1803 | do { | |
1804 | s = sk_next(s); | |
1218854a | 1805 | } while (s && sock_net(s) != seq_file_net(seq)); |
1da177e4 LT |
1806 | if (s) |
1807 | return s; | |
1808 | ||
1da177e4 LT |
1809 | i = iter->link; |
1810 | j = iter->hash_idx + 1; | |
1811 | ||
1812 | do { | |
1813 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1814 | ||
1815 | for (; j <= hash->mask; j++) { | |
1816 | s = sk_head(&hash->table[j]); | |
1218854a | 1817 | while (s && sock_net(s) != seq_file_net(seq)) |
b4b51029 | 1818 | s = sk_next(s); |
1da177e4 LT |
1819 | if (s) { |
1820 | iter->link = i; | |
1821 | iter->hash_idx = j; | |
1822 | return s; | |
1823 | } | |
1824 | } | |
1825 | ||
1826 | j = 0; | |
1827 | } while (++i < MAX_LINKS); | |
1828 | ||
1829 | return NULL; | |
1830 | } | |
1831 | ||
1832 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
9a429c49 | 1833 | __releases(nl_table_lock) |
1da177e4 LT |
1834 | { |
1835 | read_unlock(&nl_table_lock); | |
1836 | } | |
1837 | ||
1838 | ||
1839 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
1840 | { | |
1841 | if (v == SEQ_START_TOKEN) | |
1842 | seq_puts(seq, | |
1843 | "sk Eth Pid Groups " | |
1844 | "Rmem Wmem Dump Locks\n"); | |
1845 | else { | |
1846 | struct sock *s = v; | |
1847 | struct netlink_sock *nlk = nlk_sk(s); | |
1848 | ||
1849 | seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %d\n", | |
1850 | s, | |
1851 | s->sk_protocol, | |
1852 | nlk->pid, | |
513c2500 | 1853 | nlk->groups ? (u32)nlk->groups[0] : 0, |
1da177e4 LT |
1854 | atomic_read(&s->sk_rmem_alloc), |
1855 | atomic_read(&s->sk_wmem_alloc), | |
1856 | nlk->cb, | |
1857 | atomic_read(&s->sk_refcnt) | |
1858 | ); | |
1859 | ||
1860 | } | |
1861 | return 0; | |
1862 | } | |
1863 | ||
56b3d975 | 1864 | static const struct seq_operations netlink_seq_ops = { |
1da177e4 LT |
1865 | .start = netlink_seq_start, |
1866 | .next = netlink_seq_next, | |
1867 | .stop = netlink_seq_stop, | |
1868 | .show = netlink_seq_show, | |
1869 | }; | |
1870 | ||
1871 | ||
1872 | static int netlink_seq_open(struct inode *inode, struct file *file) | |
1873 | { | |
e372c414 DL |
1874 | return seq_open_net(inode, file, &netlink_seq_ops, |
1875 | sizeof(struct nl_seq_iter)); | |
b4b51029 EB |
1876 | } |
1877 | ||
da7071d7 | 1878 | static const struct file_operations netlink_seq_fops = { |
1da177e4 LT |
1879 | .owner = THIS_MODULE, |
1880 | .open = netlink_seq_open, | |
1881 | .read = seq_read, | |
1882 | .llseek = seq_lseek, | |
e372c414 | 1883 | .release = seq_release_net, |
1da177e4 LT |
1884 | }; |
1885 | ||
1886 | #endif | |
1887 | ||
1888 | int netlink_register_notifier(struct notifier_block *nb) | |
1889 | { | |
e041c683 | 1890 | return atomic_notifier_chain_register(&netlink_chain, nb); |
1da177e4 | 1891 | } |
6ac552fd | 1892 | EXPORT_SYMBOL(netlink_register_notifier); |
1da177e4 LT |
1893 | |
1894 | int netlink_unregister_notifier(struct notifier_block *nb) | |
1895 | { | |
e041c683 | 1896 | return atomic_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 | 1897 | } |
6ac552fd | 1898 | EXPORT_SYMBOL(netlink_unregister_notifier); |
746fac4d | 1899 | |
90ddc4f0 | 1900 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
1901 | .family = PF_NETLINK, |
1902 | .owner = THIS_MODULE, | |
1903 | .release = netlink_release, | |
1904 | .bind = netlink_bind, | |
1905 | .connect = netlink_connect, | |
1906 | .socketpair = sock_no_socketpair, | |
1907 | .accept = sock_no_accept, | |
1908 | .getname = netlink_getname, | |
1909 | .poll = datagram_poll, | |
1910 | .ioctl = sock_no_ioctl, | |
1911 | .listen = sock_no_listen, | |
1912 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
1913 | .setsockopt = netlink_setsockopt, |
1914 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
1915 | .sendmsg = netlink_sendmsg, |
1916 | .recvmsg = netlink_recvmsg, | |
1917 | .mmap = sock_no_mmap, | |
1918 | .sendpage = sock_no_sendpage, | |
1919 | }; | |
1920 | ||
1921 | static struct net_proto_family netlink_family_ops = { | |
1922 | .family = PF_NETLINK, | |
1923 | .create = netlink_create, | |
1924 | .owner = THIS_MODULE, /* for consistency 8) */ | |
1925 | }; | |
1926 | ||
4665079c | 1927 | static int __net_init netlink_net_init(struct net *net) |
b4b51029 EB |
1928 | { |
1929 | #ifdef CONFIG_PROC_FS | |
1930 | if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops)) | |
1931 | return -ENOMEM; | |
1932 | #endif | |
1933 | return 0; | |
1934 | } | |
1935 | ||
4665079c | 1936 | static void __net_exit netlink_net_exit(struct net *net) |
b4b51029 EB |
1937 | { |
1938 | #ifdef CONFIG_PROC_FS | |
1939 | proc_net_remove(net, "netlink"); | |
1940 | #endif | |
1941 | } | |
1942 | ||
022cbae6 | 1943 | static struct pernet_operations __net_initdata netlink_net_ops = { |
b4b51029 EB |
1944 | .init = netlink_net_init, |
1945 | .exit = netlink_net_exit, | |
1946 | }; | |
1947 | ||
1da177e4 LT |
1948 | static int __init netlink_proto_init(void) |
1949 | { | |
1950 | struct sk_buff *dummy_skb; | |
1951 | int i; | |
26ff5ddc | 1952 | unsigned long limit; |
1da177e4 LT |
1953 | unsigned int order; |
1954 | int err = proto_register(&netlink_proto, 0); | |
1955 | ||
1956 | if (err != 0) | |
1957 | goto out; | |
1958 | ||
ef047f5e | 1959 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb)); |
1da177e4 | 1960 | |
0da974f4 | 1961 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
1962 | if (!nl_table) |
1963 | goto panic; | |
1da177e4 | 1964 | |
1da177e4 | 1965 | if (num_physpages >= (128 * 1024)) |
26ff5ddc | 1966 | limit = num_physpages >> (21 - PAGE_SHIFT); |
1da177e4 | 1967 | else |
26ff5ddc | 1968 | limit = num_physpages >> (23 - PAGE_SHIFT); |
1da177e4 | 1969 | |
26ff5ddc DC |
1970 | order = get_bitmask_order(limit) - 1 + PAGE_SHIFT; |
1971 | limit = (1UL << order) / sizeof(struct hlist_head); | |
1972 | order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1; | |
1da177e4 LT |
1973 | |
1974 | for (i = 0; i < MAX_LINKS; i++) { | |
1975 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1976 | ||
ea72912c | 1977 | hash->table = nl_pid_hash_zalloc(1 * sizeof(*hash->table)); |
1da177e4 LT |
1978 | if (!hash->table) { |
1979 | while (i-- > 0) | |
1980 | nl_pid_hash_free(nl_table[i].hash.table, | |
1981 | 1 * sizeof(*hash->table)); | |
1982 | kfree(nl_table); | |
fab2caf6 | 1983 | goto panic; |
1da177e4 | 1984 | } |
1da177e4 LT |
1985 | hash->max_shift = order; |
1986 | hash->shift = 0; | |
1987 | hash->mask = 0; | |
1988 | hash->rehash_time = jiffies; | |
1989 | } | |
1990 | ||
1991 | sock_register(&netlink_family_ops); | |
b4b51029 | 1992 | register_pernet_subsys(&netlink_net_ops); |
746fac4d | 1993 | /* The netlink device handler may be needed early. */ |
1da177e4 LT |
1994 | rtnetlink_init(); |
1995 | out: | |
1996 | return err; | |
fab2caf6 AM |
1997 | panic: |
1998 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
1999 | } |
2000 | ||
1da177e4 | 2001 | core_initcall(netlink_proto_init); |