Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * NETLINK Kernel-user communication protocol. | |
3 | * | |
4 | * Authors: Alan Cox <alan@redhat.com> | |
5 | * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
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> |
e7c34970 | 57 | #include <linux/selinux.h> |
af65bdfc | 58 | #include <linux/mutex.h> |
54e0f520 | 59 | |
457c4cbc | 60 | #include <net/net_namespace.h> |
1da177e4 LT |
61 | #include <net/sock.h> |
62 | #include <net/scm.h> | |
82ace47a | 63 | #include <net/netlink.h> |
1da177e4 | 64 | |
f7fa9b10 | 65 | #define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8) |
b4ff4f04 | 66 | #define NLGRPLONGS(x) (NLGRPSZ(x)/sizeof(unsigned long)) |
1da177e4 LT |
67 | |
68 | struct netlink_sock { | |
69 | /* struct sock has to be the first member of netlink_sock */ | |
70 | struct sock sk; | |
71 | u32 pid; | |
1da177e4 | 72 | u32 dst_pid; |
d629b836 | 73 | u32 dst_group; |
f7fa9b10 PM |
74 | u32 flags; |
75 | u32 subscriptions; | |
76 | u32 ngroups; | |
77 | unsigned long *groups; | |
1da177e4 LT |
78 | unsigned long state; |
79 | wait_queue_head_t wait; | |
80 | struct netlink_callback *cb; | |
af65bdfc PM |
81 | struct mutex *cb_mutex; |
82 | struct mutex cb_def_mutex; | |
1da177e4 | 83 | void (*data_ready)(struct sock *sk, int bytes); |
77247bbb | 84 | struct module *module; |
1da177e4 LT |
85 | }; |
86 | ||
77247bbb | 87 | #define NETLINK_KERNEL_SOCKET 0x1 |
9a4595bc | 88 | #define NETLINK_RECV_PKTINFO 0x2 |
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 | ||
95 | struct nl_pid_hash { | |
96 | struct hlist_head *table; | |
97 | unsigned long rehash_time; | |
98 | ||
99 | unsigned int mask; | |
100 | unsigned int shift; | |
101 | ||
102 | unsigned int entries; | |
103 | unsigned int max_shift; | |
104 | ||
105 | u32 rnd; | |
106 | }; | |
107 | ||
108 | struct netlink_table { | |
109 | struct nl_pid_hash hash; | |
110 | struct hlist_head mc_list; | |
4277a083 | 111 | unsigned long *listeners; |
1da177e4 | 112 | unsigned int nl_nonroot; |
f7fa9b10 | 113 | unsigned int groups; |
af65bdfc | 114 | struct mutex *cb_mutex; |
77247bbb | 115 | struct module *module; |
ab33a171 | 116 | int registered; |
1da177e4 LT |
117 | }; |
118 | ||
119 | static struct netlink_table *nl_table; | |
120 | ||
121 | static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); | |
122 | ||
123 | static int netlink_dump(struct sock *sk); | |
124 | static void netlink_destroy_callback(struct netlink_callback *cb); | |
42bad1da | 125 | static void netlink_queue_skip(struct nlmsghdr *nlh, struct sk_buff *skb); |
1da177e4 LT |
126 | |
127 | static DEFINE_RWLOCK(nl_table_lock); | |
128 | static atomic_t nl_table_users = ATOMIC_INIT(0); | |
129 | ||
e041c683 | 130 | static ATOMIC_NOTIFIER_HEAD(netlink_chain); |
1da177e4 | 131 | |
d629b836 PM |
132 | static u32 netlink_group_mask(u32 group) |
133 | { | |
134 | return group ? 1 << (group - 1) : 0; | |
135 | } | |
136 | ||
1da177e4 LT |
137 | static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid) |
138 | { | |
139 | return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask]; | |
140 | } | |
141 | ||
142 | static void netlink_sock_destruct(struct sock *sk) | |
143 | { | |
3f660d66 HX |
144 | struct netlink_sock *nlk = nlk_sk(sk); |
145 | ||
3f660d66 HX |
146 | if (nlk->cb) { |
147 | if (nlk->cb->done) | |
148 | nlk->cb->done(nlk->cb); | |
149 | netlink_destroy_callback(nlk->cb); | |
150 | } | |
151 | ||
1da177e4 LT |
152 | skb_queue_purge(&sk->sk_receive_queue); |
153 | ||
154 | if (!sock_flag(sk, SOCK_DEAD)) { | |
155 | printk("Freeing alive netlink socket %p\n", sk); | |
156 | return; | |
157 | } | |
158 | BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc)); | |
159 | BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc)); | |
f7fa9b10 | 160 | BUG_TRAP(!nlk_sk(sk)->groups); |
1da177e4 LT |
161 | } |
162 | ||
163 | /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on SMP. | |
164 | * Look, when several writers sleep and reader wakes them up, all but one | |
165 | * immediately hit write lock and grab all the cpus. Exclusive sleep solves | |
166 | * this, _but_ remember, it adds useless work on UP machines. | |
167 | */ | |
168 | ||
169 | static void netlink_table_grab(void) | |
170 | { | |
6abd219c | 171 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
172 | |
173 | if (atomic_read(&nl_table_users)) { | |
174 | DECLARE_WAITQUEUE(wait, current); | |
175 | ||
176 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
177 | for(;;) { | |
178 | set_current_state(TASK_UNINTERRUPTIBLE); | |
179 | if (atomic_read(&nl_table_users) == 0) | |
180 | break; | |
6abd219c | 181 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 182 | schedule(); |
6abd219c | 183 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
184 | } |
185 | ||
186 | __set_current_state(TASK_RUNNING); | |
187 | remove_wait_queue(&nl_table_wait, &wait); | |
188 | } | |
189 | } | |
190 | ||
191 | static __inline__ void netlink_table_ungrab(void) | |
192 | { | |
6abd219c | 193 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
194 | wake_up(&nl_table_wait); |
195 | } | |
196 | ||
197 | static __inline__ void | |
198 | netlink_lock_table(void) | |
199 | { | |
200 | /* read_lock() synchronizes us to netlink_table_grab */ | |
201 | ||
202 | read_lock(&nl_table_lock); | |
203 | atomic_inc(&nl_table_users); | |
204 | read_unlock(&nl_table_lock); | |
205 | } | |
206 | ||
207 | static __inline__ void | |
208 | netlink_unlock_table(void) | |
209 | { | |
210 | if (atomic_dec_and_test(&nl_table_users)) | |
211 | wake_up(&nl_table_wait); | |
212 | } | |
213 | ||
b4b51029 | 214 | static __inline__ struct sock *netlink_lookup(struct net *net, int protocol, u32 pid) |
1da177e4 LT |
215 | { |
216 | struct nl_pid_hash *hash = &nl_table[protocol].hash; | |
217 | struct hlist_head *head; | |
218 | struct sock *sk; | |
219 | struct hlist_node *node; | |
220 | ||
221 | read_lock(&nl_table_lock); | |
222 | head = nl_pid_hashfn(hash, pid); | |
223 | sk_for_each(sk, node, head) { | |
b4b51029 | 224 | if ((sk->sk_net == net) && (nlk_sk(sk)->pid == pid)) { |
1da177e4 LT |
225 | sock_hold(sk); |
226 | goto found; | |
227 | } | |
228 | } | |
229 | sk = NULL; | |
230 | found: | |
231 | read_unlock(&nl_table_lock); | |
232 | return sk; | |
233 | } | |
234 | ||
235 | static inline struct hlist_head *nl_pid_hash_alloc(size_t size) | |
236 | { | |
237 | if (size <= PAGE_SIZE) | |
238 | return kmalloc(size, GFP_ATOMIC); | |
239 | else | |
240 | return (struct hlist_head *) | |
241 | __get_free_pages(GFP_ATOMIC, get_order(size)); | |
242 | } | |
243 | ||
244 | static inline void nl_pid_hash_free(struct hlist_head *table, size_t size) | |
245 | { | |
246 | if (size <= PAGE_SIZE) | |
247 | kfree(table); | |
248 | else | |
249 | free_pages((unsigned long)table, get_order(size)); | |
250 | } | |
251 | ||
252 | static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow) | |
253 | { | |
254 | unsigned int omask, mask, shift; | |
255 | size_t osize, size; | |
256 | struct hlist_head *otable, *table; | |
257 | int i; | |
258 | ||
259 | omask = mask = hash->mask; | |
260 | osize = size = (mask + 1) * sizeof(*table); | |
261 | shift = hash->shift; | |
262 | ||
263 | if (grow) { | |
264 | if (++shift > hash->max_shift) | |
265 | return 0; | |
266 | mask = mask * 2 + 1; | |
267 | size *= 2; | |
268 | } | |
269 | ||
270 | table = nl_pid_hash_alloc(size); | |
271 | if (!table) | |
272 | return 0; | |
273 | ||
274 | memset(table, 0, size); | |
275 | otable = hash->table; | |
276 | hash->table = table; | |
277 | hash->mask = mask; | |
278 | hash->shift = shift; | |
279 | get_random_bytes(&hash->rnd, sizeof(hash->rnd)); | |
280 | ||
281 | for (i = 0; i <= omask; i++) { | |
282 | struct sock *sk; | |
283 | struct hlist_node *node, *tmp; | |
284 | ||
285 | sk_for_each_safe(sk, node, tmp, &otable[i]) | |
286 | __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid)); | |
287 | } | |
288 | ||
289 | nl_pid_hash_free(otable, osize); | |
290 | hash->rehash_time = jiffies + 10 * 60 * HZ; | |
291 | return 1; | |
292 | } | |
293 | ||
294 | static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len) | |
295 | { | |
296 | int avg = hash->entries >> hash->shift; | |
297 | ||
298 | if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1)) | |
299 | return 1; | |
300 | ||
301 | if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) { | |
302 | nl_pid_hash_rehash(hash, 0); | |
303 | return 1; | |
304 | } | |
305 | ||
306 | return 0; | |
307 | } | |
308 | ||
90ddc4f0 | 309 | static const struct proto_ops netlink_ops; |
1da177e4 | 310 | |
4277a083 PM |
311 | static void |
312 | netlink_update_listeners(struct sock *sk) | |
313 | { | |
314 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
315 | struct hlist_node *node; | |
316 | unsigned long mask; | |
317 | unsigned int i; | |
318 | ||
b4ff4f04 | 319 | for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
4277a083 | 320 | mask = 0; |
b4ff4f04 JB |
321 | sk_for_each_bound(sk, node, &tbl->mc_list) { |
322 | if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) | |
323 | mask |= nlk_sk(sk)->groups[i]; | |
324 | } | |
4277a083 PM |
325 | tbl->listeners[i] = mask; |
326 | } | |
327 | /* this function is only called with the netlink table "grabbed", which | |
328 | * makes sure updates are visible before bind or setsockopt return. */ | |
329 | } | |
330 | ||
b4b51029 | 331 | static int netlink_insert(struct sock *sk, struct net *net, u32 pid) |
1da177e4 LT |
332 | { |
333 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; | |
334 | struct hlist_head *head; | |
335 | int err = -EADDRINUSE; | |
336 | struct sock *osk; | |
337 | struct hlist_node *node; | |
338 | int len; | |
339 | ||
340 | netlink_table_grab(); | |
341 | head = nl_pid_hashfn(hash, pid); | |
342 | len = 0; | |
343 | sk_for_each(osk, node, head) { | |
b4b51029 | 344 | if ((osk->sk_net == net) && (nlk_sk(osk)->pid == pid)) |
1da177e4 LT |
345 | break; |
346 | len++; | |
347 | } | |
348 | if (node) | |
349 | goto err; | |
350 | ||
351 | err = -EBUSY; | |
352 | if (nlk_sk(sk)->pid) | |
353 | goto err; | |
354 | ||
355 | err = -ENOMEM; | |
356 | if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX)) | |
357 | goto err; | |
358 | ||
359 | if (len && nl_pid_hash_dilute(hash, len)) | |
360 | head = nl_pid_hashfn(hash, pid); | |
361 | hash->entries++; | |
362 | nlk_sk(sk)->pid = pid; | |
363 | sk_add_node(sk, head); | |
364 | err = 0; | |
365 | ||
366 | err: | |
367 | netlink_table_ungrab(); | |
368 | return err; | |
369 | } | |
370 | ||
371 | static void netlink_remove(struct sock *sk) | |
372 | { | |
373 | netlink_table_grab(); | |
d470e3b4 DM |
374 | if (sk_del_node_init(sk)) |
375 | nl_table[sk->sk_protocol].hash.entries--; | |
f7fa9b10 | 376 | if (nlk_sk(sk)->subscriptions) |
1da177e4 LT |
377 | __sk_del_bind_node(sk); |
378 | netlink_table_ungrab(); | |
379 | } | |
380 | ||
381 | static struct proto netlink_proto = { | |
382 | .name = "NETLINK", | |
383 | .owner = THIS_MODULE, | |
384 | .obj_size = sizeof(struct netlink_sock), | |
385 | }; | |
386 | ||
1b8d7ae4 EB |
387 | static int __netlink_create(struct net *net, struct socket *sock, |
388 | struct mutex *cb_mutex, int protocol) | |
1da177e4 LT |
389 | { |
390 | struct sock *sk; | |
391 | struct netlink_sock *nlk; | |
ab33a171 PM |
392 | |
393 | sock->ops = &netlink_ops; | |
394 | ||
1b8d7ae4 | 395 | sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto, 1); |
ab33a171 PM |
396 | if (!sk) |
397 | return -ENOMEM; | |
398 | ||
399 | sock_init_data(sock, sk); | |
400 | ||
401 | nlk = nlk_sk(sk); | |
ffa4d721 PM |
402 | if (cb_mutex) |
403 | nlk->cb_mutex = cb_mutex; | |
404 | else { | |
405 | nlk->cb_mutex = &nlk->cb_def_mutex; | |
406 | mutex_init(nlk->cb_mutex); | |
407 | } | |
ab33a171 PM |
408 | init_waitqueue_head(&nlk->wait); |
409 | ||
410 | sk->sk_destruct = netlink_sock_destruct; | |
411 | sk->sk_protocol = protocol; | |
412 | return 0; | |
413 | } | |
414 | ||
1b8d7ae4 | 415 | static int netlink_create(struct net *net, struct socket *sock, int protocol) |
ab33a171 PM |
416 | { |
417 | struct module *module = NULL; | |
af65bdfc | 418 | struct mutex *cb_mutex; |
f7fa9b10 | 419 | struct netlink_sock *nlk; |
ab33a171 | 420 | int err = 0; |
1da177e4 LT |
421 | |
422 | sock->state = SS_UNCONNECTED; | |
423 | ||
424 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
425 | return -ESOCKTNOSUPPORT; | |
426 | ||
427 | if (protocol<0 || protocol >= MAX_LINKS) | |
428 | return -EPROTONOSUPPORT; | |
429 | ||
77247bbb | 430 | netlink_lock_table(); |
4fdb3bb7 | 431 | #ifdef CONFIG_KMOD |
ab33a171 | 432 | if (!nl_table[protocol].registered) { |
77247bbb | 433 | netlink_unlock_table(); |
4fdb3bb7 | 434 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 435 | netlink_lock_table(); |
4fdb3bb7 | 436 | } |
ab33a171 PM |
437 | #endif |
438 | if (nl_table[protocol].registered && | |
439 | try_module_get(nl_table[protocol].module)) | |
440 | module = nl_table[protocol].module; | |
af65bdfc | 441 | cb_mutex = nl_table[protocol].cb_mutex; |
77247bbb | 442 | netlink_unlock_table(); |
4fdb3bb7 | 443 | |
1b8d7ae4 | 444 | if ((err = __netlink_create(net, sock, cb_mutex, protocol)) < 0) |
f7fa9b10 PM |
445 | goto out_module; |
446 | ||
447 | nlk = nlk_sk(sock->sk); | |
f7fa9b10 | 448 | nlk->module = module; |
ab33a171 PM |
449 | out: |
450 | return err; | |
1da177e4 | 451 | |
ab33a171 PM |
452 | out_module: |
453 | module_put(module); | |
454 | goto out; | |
1da177e4 LT |
455 | } |
456 | ||
457 | static int netlink_release(struct socket *sock) | |
458 | { | |
459 | struct sock *sk = sock->sk; | |
460 | struct netlink_sock *nlk; | |
461 | ||
462 | if (!sk) | |
463 | return 0; | |
464 | ||
465 | netlink_remove(sk); | |
ac57b3a9 | 466 | sock_orphan(sk); |
1da177e4 LT |
467 | nlk = nlk_sk(sk); |
468 | ||
3f660d66 HX |
469 | /* |
470 | * OK. Socket is unlinked, any packets that arrive now | |
471 | * will be purged. | |
472 | */ | |
1da177e4 | 473 | |
1da177e4 LT |
474 | sock->sk = NULL; |
475 | wake_up_interruptible_all(&nlk->wait); | |
476 | ||
477 | skb_queue_purge(&sk->sk_write_queue); | |
478 | ||
f7fa9b10 | 479 | if (nlk->pid && !nlk->subscriptions) { |
1da177e4 | 480 | struct netlink_notify n = { |
b4b51029 | 481 | .net = sk->sk_net, |
1da177e4 LT |
482 | .protocol = sk->sk_protocol, |
483 | .pid = nlk->pid, | |
484 | }; | |
e041c683 AS |
485 | atomic_notifier_call_chain(&netlink_chain, |
486 | NETLINK_URELEASE, &n); | |
746fac4d | 487 | } |
4fdb3bb7 | 488 | |
5e7c001c | 489 | module_put(nlk->module); |
4fdb3bb7 | 490 | |
4277a083 | 491 | netlink_table_grab(); |
77247bbb | 492 | if (nlk->flags & NETLINK_KERNEL_SOCKET) { |
4277a083 | 493 | kfree(nl_table[sk->sk_protocol].listeners); |
77247bbb | 494 | nl_table[sk->sk_protocol].module = NULL; |
ab33a171 | 495 | nl_table[sk->sk_protocol].registered = 0; |
4277a083 PM |
496 | } else if (nlk->subscriptions) |
497 | netlink_update_listeners(sk); | |
498 | netlink_table_ungrab(); | |
77247bbb | 499 | |
f7fa9b10 PM |
500 | kfree(nlk->groups); |
501 | nlk->groups = NULL; | |
502 | ||
1da177e4 LT |
503 | sock_put(sk); |
504 | return 0; | |
505 | } | |
506 | ||
507 | static int netlink_autobind(struct socket *sock) | |
508 | { | |
509 | struct sock *sk = sock->sk; | |
b4b51029 | 510 | struct net *net = sk->sk_net; |
1da177e4 LT |
511 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; |
512 | struct hlist_head *head; | |
513 | struct sock *osk; | |
514 | struct hlist_node *node; | |
c27bd492 | 515 | s32 pid = current->tgid; |
1da177e4 LT |
516 | int err; |
517 | static s32 rover = -4097; | |
518 | ||
519 | retry: | |
520 | cond_resched(); | |
521 | netlink_table_grab(); | |
522 | head = nl_pid_hashfn(hash, pid); | |
523 | sk_for_each(osk, node, head) { | |
b4b51029 EB |
524 | if ((osk->sk_net != net)) |
525 | continue; | |
1da177e4 LT |
526 | if (nlk_sk(osk)->pid == pid) { |
527 | /* Bind collision, search negative pid values. */ | |
528 | pid = rover--; | |
529 | if (rover > -4097) | |
530 | rover = -4097; | |
531 | netlink_table_ungrab(); | |
532 | goto retry; | |
533 | } | |
534 | } | |
535 | netlink_table_ungrab(); | |
536 | ||
b4b51029 | 537 | err = netlink_insert(sk, net, pid); |
1da177e4 LT |
538 | if (err == -EADDRINUSE) |
539 | goto retry; | |
d470e3b4 DM |
540 | |
541 | /* If 2 threads race to autobind, that is fine. */ | |
542 | if (err == -EBUSY) | |
543 | err = 0; | |
544 | ||
545 | return err; | |
1da177e4 LT |
546 | } |
547 | ||
746fac4d YH |
548 | static inline int netlink_capable(struct socket *sock, unsigned int flag) |
549 | { | |
1da177e4 LT |
550 | return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) || |
551 | capable(CAP_NET_ADMIN); | |
746fac4d | 552 | } |
1da177e4 | 553 | |
f7fa9b10 PM |
554 | static void |
555 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
556 | { | |
557 | struct netlink_sock *nlk = nlk_sk(sk); | |
558 | ||
559 | if (nlk->subscriptions && !subscriptions) | |
560 | __sk_del_bind_node(sk); | |
561 | else if (!nlk->subscriptions && subscriptions) | |
562 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
563 | nlk->subscriptions = subscriptions; | |
564 | } | |
565 | ||
b4ff4f04 | 566 | static int netlink_realloc_groups(struct sock *sk) |
513c2500 PM |
567 | { |
568 | struct netlink_sock *nlk = nlk_sk(sk); | |
569 | unsigned int groups; | |
b4ff4f04 | 570 | unsigned long *new_groups; |
513c2500 PM |
571 | int err = 0; |
572 | ||
b4ff4f04 JB |
573 | netlink_table_grab(); |
574 | ||
513c2500 | 575 | groups = nl_table[sk->sk_protocol].groups; |
b4ff4f04 | 576 | if (!nl_table[sk->sk_protocol].registered) { |
513c2500 | 577 | err = -ENOENT; |
b4ff4f04 JB |
578 | goto out_unlock; |
579 | } | |
513c2500 | 580 | |
b4ff4f04 JB |
581 | if (nlk->ngroups >= groups) |
582 | goto out_unlock; | |
513c2500 | 583 | |
b4ff4f04 JB |
584 | new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
585 | if (new_groups == NULL) { | |
586 | err = -ENOMEM; | |
587 | goto out_unlock; | |
588 | } | |
589 | memset((char*)new_groups + NLGRPSZ(nlk->ngroups), 0, | |
590 | NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); | |
591 | ||
592 | nlk->groups = new_groups; | |
513c2500 | 593 | nlk->ngroups = groups; |
b4ff4f04 JB |
594 | out_unlock: |
595 | netlink_table_ungrab(); | |
596 | return err; | |
513c2500 PM |
597 | } |
598 | ||
1da177e4 LT |
599 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len) |
600 | { | |
601 | struct sock *sk = sock->sk; | |
b4b51029 | 602 | struct net *net = sk->sk_net; |
1da177e4 LT |
603 | struct netlink_sock *nlk = nlk_sk(sk); |
604 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
605 | int err; | |
746fac4d | 606 | |
1da177e4 LT |
607 | if (nladdr->nl_family != AF_NETLINK) |
608 | return -EINVAL; | |
609 | ||
610 | /* Only superuser is allowed to listen multicasts */ | |
513c2500 PM |
611 | if (nladdr->nl_groups) { |
612 | if (!netlink_capable(sock, NL_NONROOT_RECV)) | |
613 | return -EPERM; | |
b4ff4f04 JB |
614 | err = netlink_realloc_groups(sk); |
615 | if (err) | |
616 | return err; | |
513c2500 | 617 | } |
1da177e4 LT |
618 | |
619 | if (nlk->pid) { | |
620 | if (nladdr->nl_pid != nlk->pid) | |
621 | return -EINVAL; | |
622 | } else { | |
623 | err = nladdr->nl_pid ? | |
b4b51029 | 624 | netlink_insert(sk, net, nladdr->nl_pid) : |
1da177e4 LT |
625 | netlink_autobind(sock); |
626 | if (err) | |
627 | return err; | |
628 | } | |
629 | ||
513c2500 | 630 | if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
1da177e4 LT |
631 | return 0; |
632 | ||
633 | netlink_table_grab(); | |
f7fa9b10 | 634 | netlink_update_subscriptions(sk, nlk->subscriptions + |
746fac4d YH |
635 | hweight32(nladdr->nl_groups) - |
636 | hweight32(nlk->groups[0])); | |
637 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups; | |
4277a083 | 638 | netlink_update_listeners(sk); |
1da177e4 LT |
639 | netlink_table_ungrab(); |
640 | ||
641 | return 0; | |
642 | } | |
643 | ||
644 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
645 | int alen, int flags) | |
646 | { | |
647 | int err = 0; | |
648 | struct sock *sk = sock->sk; | |
649 | struct netlink_sock *nlk = nlk_sk(sk); | |
650 | struct sockaddr_nl *nladdr=(struct sockaddr_nl*)addr; | |
651 | ||
652 | if (addr->sa_family == AF_UNSPEC) { | |
653 | sk->sk_state = NETLINK_UNCONNECTED; | |
654 | nlk->dst_pid = 0; | |
d629b836 | 655 | nlk->dst_group = 0; |
1da177e4 LT |
656 | return 0; |
657 | } | |
658 | if (addr->sa_family != AF_NETLINK) | |
659 | return -EINVAL; | |
660 | ||
661 | /* Only superuser is allowed to send multicasts */ | |
662 | if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND)) | |
663 | return -EPERM; | |
664 | ||
665 | if (!nlk->pid) | |
666 | err = netlink_autobind(sock); | |
667 | ||
668 | if (err == 0) { | |
669 | sk->sk_state = NETLINK_CONNECTED; | |
670 | nlk->dst_pid = nladdr->nl_pid; | |
d629b836 | 671 | nlk->dst_group = ffs(nladdr->nl_groups); |
1da177e4 LT |
672 | } |
673 | ||
674 | return err; | |
675 | } | |
676 | ||
677 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, int *addr_len, int peer) | |
678 | { | |
679 | struct sock *sk = sock->sk; | |
680 | struct netlink_sock *nlk = nlk_sk(sk); | |
681 | struct sockaddr_nl *nladdr=(struct sockaddr_nl *)addr; | |
746fac4d | 682 | |
1da177e4 LT |
683 | nladdr->nl_family = AF_NETLINK; |
684 | nladdr->nl_pad = 0; | |
685 | *addr_len = sizeof(*nladdr); | |
686 | ||
687 | if (peer) { | |
688 | nladdr->nl_pid = nlk->dst_pid; | |
d629b836 | 689 | nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
1da177e4 LT |
690 | } else { |
691 | nladdr->nl_pid = nlk->pid; | |
513c2500 | 692 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
1da177e4 LT |
693 | } |
694 | return 0; | |
695 | } | |
696 | ||
697 | static void netlink_overrun(struct sock *sk) | |
698 | { | |
699 | if (!test_and_set_bit(0, &nlk_sk(sk)->state)) { | |
700 | sk->sk_err = ENOBUFS; | |
701 | sk->sk_error_report(sk); | |
702 | } | |
703 | } | |
704 | ||
705 | static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid) | |
706 | { | |
707 | int protocol = ssk->sk_protocol; | |
b4b51029 | 708 | struct net *net; |
1da177e4 LT |
709 | struct sock *sock; |
710 | struct netlink_sock *nlk; | |
711 | ||
b4b51029 EB |
712 | net = ssk->sk_net; |
713 | sock = netlink_lookup(net, protocol, pid); | |
1da177e4 LT |
714 | if (!sock) |
715 | return ERR_PTR(-ECONNREFUSED); | |
716 | ||
717 | /* Don't bother queuing skb if kernel socket has no input function */ | |
718 | nlk = nlk_sk(sock); | |
719 | if ((nlk->pid == 0 && !nlk->data_ready) || | |
720 | (sock->sk_state == NETLINK_CONNECTED && | |
721 | nlk->dst_pid != nlk_sk(ssk)->pid)) { | |
722 | sock_put(sock); | |
723 | return ERR_PTR(-ECONNREFUSED); | |
724 | } | |
725 | return sock; | |
726 | } | |
727 | ||
728 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
729 | { | |
6db5fc5d | 730 | struct inode *inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
731 | struct sock *sock; |
732 | ||
733 | if (!S_ISSOCK(inode->i_mode)) | |
734 | return ERR_PTR(-ENOTSOCK); | |
735 | ||
736 | sock = SOCKET_I(inode)->sk; | |
737 | if (sock->sk_family != AF_NETLINK) | |
738 | return ERR_PTR(-EINVAL); | |
739 | ||
740 | sock_hold(sock); | |
741 | return sock; | |
742 | } | |
743 | ||
744 | /* | |
745 | * Attach a skb to a netlink socket. | |
746 | * The caller must hold a reference to the destination socket. On error, the | |
747 | * reference is dropped. The skb is not send to the destination, just all | |
748 | * all error checks are performed and memory in the queue is reserved. | |
749 | * Return values: | |
750 | * < 0: error. skb freed, reference to sock dropped. | |
751 | * 0: continue | |
752 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
753 | */ | |
a70ea994 AK |
754 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock, |
755 | long timeo, struct sock *ssk) | |
1da177e4 LT |
756 | { |
757 | struct netlink_sock *nlk; | |
758 | ||
759 | nlk = nlk_sk(sk); | |
760 | ||
761 | if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
762 | test_bit(0, &nlk->state)) { | |
763 | DECLARE_WAITQUEUE(wait, current); | |
764 | if (!timeo) { | |
a70ea994 | 765 | if (!ssk || nlk_sk(ssk)->pid == 0) |
1da177e4 LT |
766 | netlink_overrun(sk); |
767 | sock_put(sk); | |
768 | kfree_skb(skb); | |
769 | return -EAGAIN; | |
770 | } | |
771 | ||
772 | __set_current_state(TASK_INTERRUPTIBLE); | |
773 | add_wait_queue(&nlk->wait, &wait); | |
774 | ||
775 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
776 | test_bit(0, &nlk->state)) && | |
777 | !sock_flag(sk, SOCK_DEAD)) | |
778 | timeo = schedule_timeout(timeo); | |
779 | ||
780 | __set_current_state(TASK_RUNNING); | |
781 | remove_wait_queue(&nlk->wait, &wait); | |
782 | sock_put(sk); | |
783 | ||
784 | if (signal_pending(current)) { | |
785 | kfree_skb(skb); | |
786 | return sock_intr_errno(timeo); | |
787 | } | |
788 | return 1; | |
789 | } | |
790 | skb_set_owner_r(skb, sk); | |
791 | return 0; | |
792 | } | |
793 | ||
794 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb, int protocol) | |
795 | { | |
1da177e4 LT |
796 | int len = skb->len; |
797 | ||
1da177e4 LT |
798 | skb_queue_tail(&sk->sk_receive_queue, skb); |
799 | sk->sk_data_ready(sk, len); | |
800 | sock_put(sk); | |
801 | return len; | |
802 | } | |
803 | ||
804 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
805 | { | |
806 | kfree_skb(skb); | |
807 | sock_put(sk); | |
808 | } | |
809 | ||
37da647d | 810 | static inline struct sk_buff *netlink_trim(struct sk_buff *skb, |
dd0fc66f | 811 | gfp_t allocation) |
1da177e4 LT |
812 | { |
813 | int delta; | |
814 | ||
815 | skb_orphan(skb); | |
816 | ||
4305b541 | 817 | delta = skb->end - skb->tail; |
1da177e4 LT |
818 | if (delta * 2 < skb->truesize) |
819 | return skb; | |
820 | ||
821 | if (skb_shared(skb)) { | |
822 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
823 | if (!nskb) | |
824 | return skb; | |
825 | kfree_skb(skb); | |
826 | skb = nskb; | |
827 | } | |
828 | ||
829 | if (!pskb_expand_head(skb, 0, -delta, allocation)) | |
830 | skb->truesize -= delta; | |
831 | ||
832 | return skb; | |
833 | } | |
834 | ||
835 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, u32 pid, int nonblock) | |
836 | { | |
837 | struct sock *sk; | |
838 | int err; | |
839 | long timeo; | |
840 | ||
841 | skb = netlink_trim(skb, gfp_any()); | |
842 | ||
843 | timeo = sock_sndtimeo(ssk, nonblock); | |
844 | retry: | |
845 | sk = netlink_getsockbypid(ssk, pid); | |
846 | if (IS_ERR(sk)) { | |
847 | kfree_skb(skb); | |
848 | return PTR_ERR(sk); | |
849 | } | |
a70ea994 | 850 | err = netlink_attachskb(sk, skb, nonblock, timeo, ssk); |
1da177e4 LT |
851 | if (err == 1) |
852 | goto retry; | |
853 | if (err) | |
854 | return err; | |
855 | ||
856 | return netlink_sendskb(sk, skb, ssk->sk_protocol); | |
857 | } | |
858 | ||
4277a083 PM |
859 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
860 | { | |
861 | int res = 0; | |
b4ff4f04 | 862 | unsigned long *listeners; |
4277a083 PM |
863 | |
864 | BUG_ON(!(nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET)); | |
b4ff4f04 JB |
865 | |
866 | rcu_read_lock(); | |
867 | listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); | |
868 | ||
4277a083 | 869 | if (group - 1 < nl_table[sk->sk_protocol].groups) |
b4ff4f04 JB |
870 | res = test_bit(group - 1, listeners); |
871 | ||
872 | rcu_read_unlock(); | |
873 | ||
4277a083 PM |
874 | return res; |
875 | } | |
876 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
877 | ||
1da177e4 LT |
878 | static __inline__ int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) |
879 | { | |
880 | struct netlink_sock *nlk = nlk_sk(sk); | |
881 | ||
882 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
883 | !test_bit(0, &nlk->state)) { | |
884 | skb_set_owner_r(skb, sk); | |
885 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
886 | sk->sk_data_ready(sk, skb->len); | |
887 | return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf; | |
888 | } | |
889 | return -1; | |
890 | } | |
891 | ||
892 | struct netlink_broadcast_data { | |
893 | struct sock *exclude_sk; | |
b4b51029 | 894 | struct net *net; |
1da177e4 LT |
895 | u32 pid; |
896 | u32 group; | |
897 | int failure; | |
898 | int congested; | |
899 | int delivered; | |
7d877f3b | 900 | gfp_t allocation; |
1da177e4 LT |
901 | struct sk_buff *skb, *skb2; |
902 | }; | |
903 | ||
904 | static inline int do_one_broadcast(struct sock *sk, | |
905 | struct netlink_broadcast_data *p) | |
906 | { | |
907 | struct netlink_sock *nlk = nlk_sk(sk); | |
908 | int val; | |
909 | ||
910 | if (p->exclude_sk == sk) | |
911 | goto out; | |
912 | ||
f7fa9b10 PM |
913 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
914 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
915 | goto out; |
916 | ||
b4b51029 EB |
917 | if ((sk->sk_net != p->net)) |
918 | goto out; | |
919 | ||
1da177e4 LT |
920 | if (p->failure) { |
921 | netlink_overrun(sk); | |
922 | goto out; | |
923 | } | |
924 | ||
925 | sock_hold(sk); | |
926 | if (p->skb2 == NULL) { | |
68acc024 | 927 | if (skb_shared(p->skb)) { |
1da177e4 LT |
928 | p->skb2 = skb_clone(p->skb, p->allocation); |
929 | } else { | |
68acc024 TC |
930 | p->skb2 = skb_get(p->skb); |
931 | /* | |
932 | * skb ownership may have been set when | |
933 | * delivered to a previous socket. | |
934 | */ | |
935 | skb_orphan(p->skb2); | |
1da177e4 LT |
936 | } |
937 | } | |
938 | if (p->skb2 == NULL) { | |
939 | netlink_overrun(sk); | |
940 | /* Clone failed. Notify ALL listeners. */ | |
941 | p->failure = 1; | |
942 | } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) { | |
943 | netlink_overrun(sk); | |
944 | } else { | |
945 | p->congested |= val; | |
946 | p->delivered = 1; | |
947 | p->skb2 = NULL; | |
948 | } | |
949 | sock_put(sk); | |
950 | ||
951 | out: | |
952 | return 0; | |
953 | } | |
954 | ||
955 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid, | |
dd0fc66f | 956 | u32 group, gfp_t allocation) |
1da177e4 | 957 | { |
b4b51029 | 958 | struct net *net = ssk->sk_net; |
1da177e4 LT |
959 | struct netlink_broadcast_data info; |
960 | struct hlist_node *node; | |
961 | struct sock *sk; | |
962 | ||
963 | skb = netlink_trim(skb, allocation); | |
964 | ||
965 | info.exclude_sk = ssk; | |
b4b51029 | 966 | info.net = net; |
1da177e4 LT |
967 | info.pid = pid; |
968 | info.group = group; | |
969 | info.failure = 0; | |
970 | info.congested = 0; | |
971 | info.delivered = 0; | |
972 | info.allocation = allocation; | |
973 | info.skb = skb; | |
974 | info.skb2 = NULL; | |
975 | ||
976 | /* While we sleep in clone, do not allow to change socket list */ | |
977 | ||
978 | netlink_lock_table(); | |
979 | ||
980 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
981 | do_one_broadcast(sk, &info); | |
982 | ||
aa1c6a6f TC |
983 | kfree_skb(skb); |
984 | ||
1da177e4 LT |
985 | netlink_unlock_table(); |
986 | ||
987 | if (info.skb2) | |
988 | kfree_skb(info.skb2); | |
1da177e4 LT |
989 | |
990 | if (info.delivered) { | |
991 | if (info.congested && (allocation & __GFP_WAIT)) | |
992 | yield(); | |
993 | return 0; | |
994 | } | |
995 | if (info.failure) | |
996 | return -ENOBUFS; | |
997 | return -ESRCH; | |
998 | } | |
999 | ||
1000 | struct netlink_set_err_data { | |
1001 | struct sock *exclude_sk; | |
1002 | u32 pid; | |
1003 | u32 group; | |
1004 | int code; | |
1005 | }; | |
1006 | ||
1007 | static inline int do_one_set_err(struct sock *sk, | |
1008 | struct netlink_set_err_data *p) | |
1009 | { | |
1010 | struct netlink_sock *nlk = nlk_sk(sk); | |
1011 | ||
1012 | if (sk == p->exclude_sk) | |
1013 | goto out; | |
1014 | ||
b4b51029 EB |
1015 | if (sk->sk_net != p->exclude_sk->sk_net) |
1016 | goto out; | |
1017 | ||
f7fa9b10 PM |
1018 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
1019 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
1020 | goto out; |
1021 | ||
1022 | sk->sk_err = p->code; | |
1023 | sk->sk_error_report(sk); | |
1024 | out: | |
1025 | return 0; | |
1026 | } | |
1027 | ||
1028 | void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) | |
1029 | { | |
1030 | struct netlink_set_err_data info; | |
1031 | struct hlist_node *node; | |
1032 | struct sock *sk; | |
1033 | ||
1034 | info.exclude_sk = ssk; | |
1035 | info.pid = pid; | |
1036 | info.group = group; | |
1037 | info.code = code; | |
1038 | ||
1039 | read_lock(&nl_table_lock); | |
1040 | ||
1041 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1042 | do_one_set_err(sk, &info); | |
1043 | ||
1044 | read_unlock(&nl_table_lock); | |
1045 | } | |
1046 | ||
84659eb5 JB |
1047 | /* must be called with netlink table grabbed */ |
1048 | static void netlink_update_socket_mc(struct netlink_sock *nlk, | |
1049 | unsigned int group, | |
1050 | int is_new) | |
1051 | { | |
1052 | int old, new = !!is_new, subscriptions; | |
1053 | ||
1054 | old = test_bit(group - 1, nlk->groups); | |
1055 | subscriptions = nlk->subscriptions - old + new; | |
1056 | if (new) | |
1057 | __set_bit(group - 1, nlk->groups); | |
1058 | else | |
1059 | __clear_bit(group - 1, nlk->groups); | |
1060 | netlink_update_subscriptions(&nlk->sk, subscriptions); | |
1061 | netlink_update_listeners(&nlk->sk); | |
1062 | } | |
1063 | ||
9a4595bc | 1064 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
746fac4d | 1065 | char __user *optval, int optlen) |
9a4595bc PM |
1066 | { |
1067 | struct sock *sk = sock->sk; | |
1068 | struct netlink_sock *nlk = nlk_sk(sk); | |
eb496534 JB |
1069 | unsigned int val = 0; |
1070 | int err; | |
9a4595bc PM |
1071 | |
1072 | if (level != SOL_NETLINK) | |
1073 | return -ENOPROTOOPT; | |
1074 | ||
1075 | if (optlen >= sizeof(int) && | |
eb496534 | 1076 | get_user(val, (unsigned int __user *)optval)) |
9a4595bc PM |
1077 | return -EFAULT; |
1078 | ||
1079 | switch (optname) { | |
1080 | case NETLINK_PKTINFO: | |
1081 | if (val) | |
1082 | nlk->flags |= NETLINK_RECV_PKTINFO; | |
1083 | else | |
1084 | nlk->flags &= ~NETLINK_RECV_PKTINFO; | |
1085 | err = 0; | |
1086 | break; | |
1087 | case NETLINK_ADD_MEMBERSHIP: | |
1088 | case NETLINK_DROP_MEMBERSHIP: { | |
9a4595bc PM |
1089 | if (!netlink_capable(sock, NL_NONROOT_RECV)) |
1090 | return -EPERM; | |
b4ff4f04 JB |
1091 | err = netlink_realloc_groups(sk); |
1092 | if (err) | |
1093 | return err; | |
9a4595bc PM |
1094 | if (!val || val - 1 >= nlk->ngroups) |
1095 | return -EINVAL; | |
1096 | netlink_table_grab(); | |
84659eb5 JB |
1097 | netlink_update_socket_mc(nlk, val, |
1098 | optname == NETLINK_ADD_MEMBERSHIP); | |
9a4595bc PM |
1099 | netlink_table_ungrab(); |
1100 | err = 0; | |
1101 | break; | |
1102 | } | |
1103 | default: | |
1104 | err = -ENOPROTOOPT; | |
1105 | } | |
1106 | return err; | |
1107 | } | |
1108 | ||
1109 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
746fac4d | 1110 | char __user *optval, int __user *optlen) |
9a4595bc PM |
1111 | { |
1112 | struct sock *sk = sock->sk; | |
1113 | struct netlink_sock *nlk = nlk_sk(sk); | |
1114 | int len, val, err; | |
1115 | ||
1116 | if (level != SOL_NETLINK) | |
1117 | return -ENOPROTOOPT; | |
1118 | ||
1119 | if (get_user(len, optlen)) | |
1120 | return -EFAULT; | |
1121 | if (len < 0) | |
1122 | return -EINVAL; | |
1123 | ||
1124 | switch (optname) { | |
1125 | case NETLINK_PKTINFO: | |
1126 | if (len < sizeof(int)) | |
1127 | return -EINVAL; | |
1128 | len = sizeof(int); | |
1129 | val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0; | |
a27b58fe HC |
1130 | if (put_user(len, optlen) || |
1131 | put_user(val, optval)) | |
1132 | return -EFAULT; | |
9a4595bc PM |
1133 | err = 0; |
1134 | break; | |
1135 | default: | |
1136 | err = -ENOPROTOOPT; | |
1137 | } | |
1138 | return err; | |
1139 | } | |
1140 | ||
1141 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
1142 | { | |
1143 | struct nl_pktinfo info; | |
1144 | ||
1145 | info.group = NETLINK_CB(skb).dst_group; | |
1146 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
1147 | } | |
1148 | ||
1da177e4 LT |
1149 | static inline void netlink_rcv_wake(struct sock *sk) |
1150 | { | |
1151 | struct netlink_sock *nlk = nlk_sk(sk); | |
1152 | ||
b03efcfb | 1153 | if (skb_queue_empty(&sk->sk_receive_queue)) |
1da177e4 LT |
1154 | clear_bit(0, &nlk->state); |
1155 | if (!test_bit(0, &nlk->state)) | |
1156 | wake_up_interruptible(&nlk->wait); | |
1157 | } | |
1158 | ||
1159 | static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, | |
1160 | struct msghdr *msg, size_t len) | |
1161 | { | |
1162 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1163 | struct sock *sk = sock->sk; | |
1164 | struct netlink_sock *nlk = nlk_sk(sk); | |
1165 | struct sockaddr_nl *addr=msg->msg_name; | |
1166 | u32 dst_pid; | |
d629b836 | 1167 | u32 dst_group; |
1da177e4 LT |
1168 | struct sk_buff *skb; |
1169 | int err; | |
1170 | struct scm_cookie scm; | |
1171 | ||
1172 | if (msg->msg_flags&MSG_OOB) | |
1173 | return -EOPNOTSUPP; | |
1174 | ||
1175 | if (NULL == siocb->scm) | |
1176 | siocb->scm = &scm; | |
1177 | err = scm_send(sock, msg, siocb->scm); | |
1178 | if (err < 0) | |
1179 | return err; | |
1180 | ||
1181 | if (msg->msg_namelen) { | |
1182 | if (addr->nl_family != AF_NETLINK) | |
1183 | return -EINVAL; | |
1184 | dst_pid = addr->nl_pid; | |
d629b836 PM |
1185 | dst_group = ffs(addr->nl_groups); |
1186 | if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND)) | |
1da177e4 LT |
1187 | return -EPERM; |
1188 | } else { | |
1189 | dst_pid = nlk->dst_pid; | |
d629b836 | 1190 | dst_group = nlk->dst_group; |
1da177e4 LT |
1191 | } |
1192 | ||
1193 | if (!nlk->pid) { | |
1194 | err = netlink_autobind(sock); | |
1195 | if (err) | |
1196 | goto out; | |
1197 | } | |
1198 | ||
1199 | err = -EMSGSIZE; | |
1200 | if (len > sk->sk_sndbuf - 32) | |
1201 | goto out; | |
1202 | err = -ENOBUFS; | |
339bf98f | 1203 | skb = alloc_skb(len, GFP_KERNEL); |
1da177e4 LT |
1204 | if (skb==NULL) |
1205 | goto out; | |
1206 | ||
1207 | NETLINK_CB(skb).pid = nlk->pid; | |
d629b836 | 1208 | NETLINK_CB(skb).dst_group = dst_group; |
c94c257c | 1209 | NETLINK_CB(skb).loginuid = audit_get_loginuid(current->audit_context); |
e7c34970 | 1210 | selinux_get_task_sid(current, &(NETLINK_CB(skb).sid)); |
1da177e4 LT |
1211 | memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); |
1212 | ||
1213 | /* What can I do? Netlink is asynchronous, so that | |
1214 | we will have to save current capabilities to | |
1215 | check them, when this message will be delivered | |
1216 | to corresponding kernel module. --ANK (980802) | |
1217 | */ | |
1218 | ||
1219 | err = -EFAULT; | |
1220 | if (memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len)) { | |
1221 | kfree_skb(skb); | |
1222 | goto out; | |
1223 | } | |
1224 | ||
1225 | err = security_netlink_send(sk, skb); | |
1226 | if (err) { | |
1227 | kfree_skb(skb); | |
1228 | goto out; | |
1229 | } | |
1230 | ||
d629b836 | 1231 | if (dst_group) { |
1da177e4 | 1232 | atomic_inc(&skb->users); |
d629b836 | 1233 | netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL); |
1da177e4 LT |
1234 | } |
1235 | err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT); | |
1236 | ||
1237 | out: | |
1238 | return err; | |
1239 | } | |
1240 | ||
1241 | static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, | |
1242 | struct msghdr *msg, size_t len, | |
1243 | int flags) | |
1244 | { | |
1245 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1246 | struct scm_cookie scm; | |
1247 | struct sock *sk = sock->sk; | |
1248 | struct netlink_sock *nlk = nlk_sk(sk); | |
1249 | int noblock = flags&MSG_DONTWAIT; | |
1250 | size_t copied; | |
1251 | struct sk_buff *skb; | |
1252 | int err; | |
1253 | ||
1254 | if (flags&MSG_OOB) | |
1255 | return -EOPNOTSUPP; | |
1256 | ||
1257 | copied = 0; | |
1258 | ||
1259 | skb = skb_recv_datagram(sk,flags,noblock,&err); | |
1260 | if (skb==NULL) | |
1261 | goto out; | |
1262 | ||
1263 | msg->msg_namelen = 0; | |
1264 | ||
1265 | copied = skb->len; | |
1266 | if (len < copied) { | |
1267 | msg->msg_flags |= MSG_TRUNC; | |
1268 | copied = len; | |
1269 | } | |
1270 | ||
badff6d0 | 1271 | skb_reset_transport_header(skb); |
1da177e4 LT |
1272 | err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); |
1273 | ||
1274 | if (msg->msg_name) { | |
1275 | struct sockaddr_nl *addr = (struct sockaddr_nl*)msg->msg_name; | |
1276 | addr->nl_family = AF_NETLINK; | |
1277 | addr->nl_pad = 0; | |
1278 | addr->nl_pid = NETLINK_CB(skb).pid; | |
d629b836 | 1279 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
1280 | msg->msg_namelen = sizeof(*addr); |
1281 | } | |
1282 | ||
cc9a06cd PM |
1283 | if (nlk->flags & NETLINK_RECV_PKTINFO) |
1284 | netlink_cmsg_recv_pktinfo(msg, skb); | |
1285 | ||
1da177e4 LT |
1286 | if (NULL == siocb->scm) { |
1287 | memset(&scm, 0, sizeof(scm)); | |
1288 | siocb->scm = &scm; | |
1289 | } | |
1290 | siocb->scm->creds = *NETLINK_CREDS(skb); | |
188ccb55 PM |
1291 | if (flags & MSG_TRUNC) |
1292 | copied = skb->len; | |
1da177e4 LT |
1293 | skb_free_datagram(sk, skb); |
1294 | ||
1295 | if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) | |
1296 | netlink_dump(sk); | |
1297 | ||
1298 | scm_recv(sock, msg, siocb->scm, flags); | |
1da177e4 LT |
1299 | out: |
1300 | netlink_rcv_wake(sk); | |
1301 | return err ? : copied; | |
1302 | } | |
1303 | ||
1304 | static void netlink_data_ready(struct sock *sk, int len) | |
1305 | { | |
1306 | struct netlink_sock *nlk = nlk_sk(sk); | |
1307 | ||
1308 | if (nlk->data_ready) | |
1309 | nlk->data_ready(sk, len); | |
1310 | netlink_rcv_wake(sk); | |
1311 | } | |
1312 | ||
1313 | /* | |
746fac4d | 1314 | * We export these functions to other modules. They provide a |
1da177e4 LT |
1315 | * complete set of kernel non-blocking support for message |
1316 | * queueing. | |
1317 | */ | |
1318 | ||
1319 | struct sock * | |
b4b51029 | 1320 | netlink_kernel_create(struct net *net, int unit, unsigned int groups, |
746fac4d | 1321 | void (*input)(struct sock *sk, int len), |
af65bdfc | 1322 | struct mutex *cb_mutex, struct module *module) |
1da177e4 LT |
1323 | { |
1324 | struct socket *sock; | |
1325 | struct sock *sk; | |
77247bbb | 1326 | struct netlink_sock *nlk; |
4277a083 | 1327 | unsigned long *listeners = NULL; |
1da177e4 | 1328 | |
fab2caf6 | 1329 | BUG_ON(!nl_table); |
1da177e4 LT |
1330 | |
1331 | if (unit<0 || unit>=MAX_LINKS) | |
1332 | return NULL; | |
1333 | ||
1334 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
1335 | return NULL; | |
1336 | ||
b4b51029 | 1337 | if (__netlink_create(net, sock, cb_mutex, unit) < 0) |
77247bbb | 1338 | goto out_sock_release; |
4fdb3bb7 | 1339 | |
4277a083 PM |
1340 | if (groups < 32) |
1341 | groups = 32; | |
1342 | ||
1343 | listeners = kzalloc(NLGRPSZ(groups), GFP_KERNEL); | |
1344 | if (!listeners) | |
1345 | goto out_sock_release; | |
1346 | ||
1da177e4 LT |
1347 | sk = sock->sk; |
1348 | sk->sk_data_ready = netlink_data_ready; | |
1349 | if (input) | |
1350 | nlk_sk(sk)->data_ready = input; | |
1351 | ||
b4b51029 | 1352 | if (netlink_insert(sk, net, 0)) |
77247bbb | 1353 | goto out_sock_release; |
4fdb3bb7 | 1354 | |
77247bbb PM |
1355 | nlk = nlk_sk(sk); |
1356 | nlk->flags |= NETLINK_KERNEL_SOCKET; | |
4fdb3bb7 | 1357 | |
4fdb3bb7 | 1358 | netlink_table_grab(); |
b4b51029 EB |
1359 | if (!nl_table[unit].registered) { |
1360 | nl_table[unit].groups = groups; | |
1361 | nl_table[unit].listeners = listeners; | |
1362 | nl_table[unit].cb_mutex = cb_mutex; | |
1363 | nl_table[unit].module = module; | |
1364 | nl_table[unit].registered = 1; | |
1365 | } | |
4fdb3bb7 | 1366 | netlink_table_ungrab(); |
77247bbb PM |
1367 | |
1368 | return sk; | |
1369 | ||
4fdb3bb7 | 1370 | out_sock_release: |
4277a083 | 1371 | kfree(listeners); |
4fdb3bb7 | 1372 | sock_release(sock); |
77247bbb | 1373 | return NULL; |
1da177e4 LT |
1374 | } |
1375 | ||
b4ff4f04 JB |
1376 | /** |
1377 | * netlink_change_ngroups - change number of multicast groups | |
1378 | * | |
1379 | * This changes the number of multicast groups that are available | |
1380 | * on a certain netlink family. Note that it is not possible to | |
84659eb5 JB |
1381 | * change the number of groups to below 32. Also note that it does |
1382 | * not implicitly call netlink_clear_multicast_users() when the | |
1383 | * number of groups is reduced. | |
b4ff4f04 JB |
1384 | * |
1385 | * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). | |
1386 | * @groups: The new number of groups. | |
1387 | */ | |
1388 | int netlink_change_ngroups(struct sock *sk, unsigned int groups) | |
1389 | { | |
1390 | unsigned long *listeners, *old = NULL; | |
1391 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
1392 | int err = 0; | |
1393 | ||
1394 | if (groups < 32) | |
1395 | groups = 32; | |
1396 | ||
1397 | netlink_table_grab(); | |
1398 | if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { | |
1399 | listeners = kzalloc(NLGRPSZ(groups), GFP_ATOMIC); | |
1400 | if (!listeners) { | |
1401 | err = -ENOMEM; | |
1402 | goto out_ungrab; | |
1403 | } | |
1404 | old = tbl->listeners; | |
1405 | memcpy(listeners, old, NLGRPSZ(tbl->groups)); | |
1406 | rcu_assign_pointer(tbl->listeners, listeners); | |
1407 | } | |
1408 | tbl->groups = groups; | |
1409 | ||
1410 | out_ungrab: | |
1411 | netlink_table_ungrab(); | |
1412 | synchronize_rcu(); | |
1413 | kfree(old); | |
1414 | return err; | |
1415 | } | |
1416 | EXPORT_SYMBOL(netlink_change_ngroups); | |
1417 | ||
84659eb5 JB |
1418 | /** |
1419 | * netlink_clear_multicast_users - kick off multicast listeners | |
1420 | * | |
1421 | * This function removes all listeners from the given group. | |
1422 | * @ksk: The kernel netlink socket, as returned by | |
1423 | * netlink_kernel_create(). | |
1424 | * @group: The multicast group to clear. | |
1425 | */ | |
1426 | void netlink_clear_multicast_users(struct sock *ksk, unsigned int group) | |
1427 | { | |
1428 | struct sock *sk; | |
1429 | struct hlist_node *node; | |
1430 | struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; | |
1431 | ||
1432 | netlink_table_grab(); | |
1433 | ||
1434 | sk_for_each_bound(sk, node, &tbl->mc_list) | |
1435 | netlink_update_socket_mc(nlk_sk(sk), group, 0); | |
1436 | ||
1437 | netlink_table_ungrab(); | |
1438 | } | |
1439 | EXPORT_SYMBOL(netlink_clear_multicast_users); | |
1440 | ||
1da177e4 | 1441 | void netlink_set_nonroot(int protocol, unsigned int flags) |
746fac4d YH |
1442 | { |
1443 | if ((unsigned int)protocol < MAX_LINKS) | |
1da177e4 | 1444 | nl_table[protocol].nl_nonroot = flags; |
746fac4d | 1445 | } |
1da177e4 LT |
1446 | |
1447 | static void netlink_destroy_callback(struct netlink_callback *cb) | |
1448 | { | |
1449 | if (cb->skb) | |
1450 | kfree_skb(cb->skb); | |
1451 | kfree(cb); | |
1452 | } | |
1453 | ||
1454 | /* | |
1455 | * It looks a bit ugly. | |
1456 | * It would be better to create kernel thread. | |
1457 | */ | |
1458 | ||
1459 | static int netlink_dump(struct sock *sk) | |
1460 | { | |
1461 | struct netlink_sock *nlk = nlk_sk(sk); | |
1462 | struct netlink_callback *cb; | |
1463 | struct sk_buff *skb; | |
1464 | struct nlmsghdr *nlh; | |
bf8b79e4 | 1465 | int len, err = -ENOBUFS; |
746fac4d | 1466 | |
1da177e4 LT |
1467 | skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL); |
1468 | if (!skb) | |
bf8b79e4 | 1469 | goto errout; |
1da177e4 | 1470 | |
af65bdfc | 1471 | mutex_lock(nlk->cb_mutex); |
1da177e4 LT |
1472 | |
1473 | cb = nlk->cb; | |
1474 | if (cb == NULL) { | |
bf8b79e4 TG |
1475 | err = -EINVAL; |
1476 | goto errout_skb; | |
1da177e4 LT |
1477 | } |
1478 | ||
1479 | len = cb->dump(skb, cb); | |
1480 | ||
1481 | if (len > 0) { | |
af65bdfc | 1482 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1483 | skb_queue_tail(&sk->sk_receive_queue, skb); |
1484 | sk->sk_data_ready(sk, len); | |
1485 | return 0; | |
1486 | } | |
1487 | ||
bf8b79e4 TG |
1488 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); |
1489 | if (!nlh) | |
1490 | goto errout_skb; | |
1491 | ||
1492 | memcpy(nlmsg_data(nlh), &len, sizeof(len)); | |
1493 | ||
1da177e4 LT |
1494 | skb_queue_tail(&sk->sk_receive_queue, skb); |
1495 | sk->sk_data_ready(sk, skb->len); | |
1496 | ||
a8f74b22 TG |
1497 | if (cb->done) |
1498 | cb->done(cb); | |
1da177e4 | 1499 | nlk->cb = NULL; |
af65bdfc | 1500 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1501 | |
1502 | netlink_destroy_callback(cb); | |
1da177e4 | 1503 | return 0; |
1797754e | 1504 | |
bf8b79e4 | 1505 | errout_skb: |
af65bdfc | 1506 | mutex_unlock(nlk->cb_mutex); |
bf8b79e4 TG |
1507 | kfree_skb(skb); |
1508 | errout: | |
1509 | return err; | |
1da177e4 LT |
1510 | } |
1511 | ||
1512 | int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, | |
1513 | struct nlmsghdr *nlh, | |
1514 | int (*dump)(struct sk_buff *skb, struct netlink_callback*), | |
1515 | int (*done)(struct netlink_callback*)) | |
1516 | { | |
1517 | struct netlink_callback *cb; | |
1518 | struct sock *sk; | |
1519 | struct netlink_sock *nlk; | |
1520 | ||
0da974f4 | 1521 | cb = kzalloc(sizeof(*cb), GFP_KERNEL); |
1da177e4 LT |
1522 | if (cb == NULL) |
1523 | return -ENOBUFS; | |
1524 | ||
1da177e4 LT |
1525 | cb->dump = dump; |
1526 | cb->done = done; | |
1527 | cb->nlh = nlh; | |
1528 | atomic_inc(&skb->users); | |
1529 | cb->skb = skb; | |
1530 | ||
b4b51029 | 1531 | sk = netlink_lookup(ssk->sk_net, ssk->sk_protocol, NETLINK_CB(skb).pid); |
1da177e4 LT |
1532 | if (sk == NULL) { |
1533 | netlink_destroy_callback(cb); | |
1534 | return -ECONNREFUSED; | |
1535 | } | |
1536 | nlk = nlk_sk(sk); | |
3f660d66 | 1537 | /* A dump is in progress... */ |
af65bdfc | 1538 | mutex_lock(nlk->cb_mutex); |
3f660d66 | 1539 | if (nlk->cb) { |
af65bdfc | 1540 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1541 | netlink_destroy_callback(cb); |
1542 | sock_put(sk); | |
1543 | return -EBUSY; | |
1544 | } | |
1545 | nlk->cb = cb; | |
af65bdfc | 1546 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1547 | |
1548 | netlink_dump(sk); | |
1549 | sock_put(sk); | |
c702e804 TG |
1550 | |
1551 | /* We successfully started a dump, by returning -EINTR we | |
1552 | * signal the queue mangement to interrupt processing of | |
1553 | * any netlink messages so userspace gets a chance to read | |
1554 | * the results. */ | |
1555 | return -EINTR; | |
1da177e4 LT |
1556 | } |
1557 | ||
1558 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) | |
1559 | { | |
1560 | struct sk_buff *skb; | |
1561 | struct nlmsghdr *rep; | |
1562 | struct nlmsgerr *errmsg; | |
339bf98f | 1563 | size_t payload = sizeof(*errmsg); |
1da177e4 | 1564 | |
339bf98f TG |
1565 | /* error messages get the original request appened */ |
1566 | if (err) | |
1567 | payload += nlmsg_len(nlh); | |
1da177e4 | 1568 | |
339bf98f | 1569 | skb = nlmsg_new(payload, GFP_KERNEL); |
1da177e4 LT |
1570 | if (!skb) { |
1571 | struct sock *sk; | |
1572 | ||
b4b51029 EB |
1573 | sk = netlink_lookup(in_skb->sk->sk_net, |
1574 | in_skb->sk->sk_protocol, | |
1da177e4 LT |
1575 | NETLINK_CB(in_skb).pid); |
1576 | if (sk) { | |
1577 | sk->sk_err = ENOBUFS; | |
1578 | sk->sk_error_report(sk); | |
1579 | sock_put(sk); | |
1580 | } | |
1581 | return; | |
1582 | } | |
1583 | ||
1584 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, | |
1797754e | 1585 | NLMSG_ERROR, sizeof(struct nlmsgerr), 0); |
bf8b79e4 | 1586 | errmsg = nlmsg_data(rep); |
1da177e4 | 1587 | errmsg->error = err; |
bf8b79e4 | 1588 | memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh)); |
1da177e4 LT |
1589 | netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT); |
1590 | } | |
1591 | ||
82ace47a | 1592 | static int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
1d00a4eb | 1593 | struct nlmsghdr *)) |
82ace47a | 1594 | { |
82ace47a TG |
1595 | struct nlmsghdr *nlh; |
1596 | int err; | |
1597 | ||
1598 | while (skb->len >= nlmsg_total_size(0)) { | |
b529ccf2 | 1599 | nlh = nlmsg_hdr(skb); |
d35b6856 | 1600 | err = 0; |
82ace47a | 1601 | |
ad8e4b75 | 1602 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
1603 | return 0; |
1604 | ||
d35b6856 TG |
1605 | /* Only requests are handled by the kernel */ |
1606 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | |
1607 | goto skip; | |
45e7ae7f TG |
1608 | |
1609 | /* Skip control messages */ | |
1610 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | |
1611 | goto skip; | |
d35b6856 | 1612 | |
1d00a4eb TG |
1613 | err = cb(skb, nlh); |
1614 | if (err == -EINTR) { | |
1615 | /* Not an error, but we interrupt processing */ | |
1616 | netlink_queue_skip(nlh, skb); | |
1617 | return err; | |
d35b6856 TG |
1618 | } |
1619 | skip: | |
1620 | if (nlh->nlmsg_flags & NLM_F_ACK || err) | |
82ace47a | 1621 | netlink_ack(skb, nlh, err); |
82ace47a | 1622 | |
bf8b79e4 | 1623 | netlink_queue_skip(nlh, skb); |
82ace47a TG |
1624 | } |
1625 | ||
1626 | return 0; | |
1627 | } | |
1628 | ||
1629 | /** | |
1630 | * nelink_run_queue - Process netlink receive queue. | |
1631 | * @sk: Netlink socket containing the queue | |
1632 | * @qlen: Place to store queue length upon entry | |
1633 | * @cb: Callback function invoked for each netlink message found | |
1634 | * | |
1635 | * Processes as much as there was in the queue upon entry and invokes | |
1636 | * a callback function for each netlink message found. The callback | |
1637 | * function may refuse a message by returning a negative error code | |
1638 | * but setting the error pointer to 0 in which case this function | |
1639 | * returns with a qlen != 0. | |
1640 | * | |
1641 | * qlen must be initialized to 0 before the initial entry, afterwards | |
1642 | * the function may be called repeatedly until qlen reaches 0. | |
1d00a4eb TG |
1643 | * |
1644 | * The callback function may return -EINTR to signal that processing | |
1645 | * of netlink messages shall be interrupted. In this case the message | |
1646 | * currently being processed will NOT be requeued onto the receive | |
1647 | * queue. | |
82ace47a TG |
1648 | */ |
1649 | void netlink_run_queue(struct sock *sk, unsigned int *qlen, | |
1d00a4eb | 1650 | int (*cb)(struct sk_buff *, struct nlmsghdr *)) |
82ace47a TG |
1651 | { |
1652 | struct sk_buff *skb; | |
1653 | ||
1654 | if (!*qlen || *qlen > skb_queue_len(&sk->sk_receive_queue)) | |
1655 | *qlen = skb_queue_len(&sk->sk_receive_queue); | |
1656 | ||
1657 | for (; *qlen; (*qlen)--) { | |
1658 | skb = skb_dequeue(&sk->sk_receive_queue); | |
1659 | if (netlink_rcv_skb(skb, cb)) { | |
1660 | if (skb->len) | |
1661 | skb_queue_head(&sk->sk_receive_queue, skb); | |
1662 | else { | |
1663 | kfree_skb(skb); | |
1664 | (*qlen)--; | |
1665 | } | |
1666 | break; | |
1667 | } | |
1668 | ||
1669 | kfree_skb(skb); | |
1670 | } | |
1671 | } | |
1672 | ||
1673 | /** | |
1674 | * netlink_queue_skip - Skip netlink message while processing queue. | |
1675 | * @nlh: Netlink message to be skipped | |
1676 | * @skb: Socket buffer containing the netlink messages. | |
1677 | * | |
1678 | * Pulls the given netlink message off the socket buffer so the next | |
1679 | * call to netlink_queue_run() will not reconsider the message. | |
1680 | */ | |
42bad1da | 1681 | static void netlink_queue_skip(struct nlmsghdr *nlh, struct sk_buff *skb) |
82ace47a TG |
1682 | { |
1683 | int msglen = NLMSG_ALIGN(nlh->nlmsg_len); | |
1684 | ||
1685 | if (msglen > skb->len) | |
1686 | msglen = skb->len; | |
1687 | ||
1688 | skb_pull(skb, msglen); | |
1689 | } | |
1da177e4 | 1690 | |
d387f6ad TG |
1691 | /** |
1692 | * nlmsg_notify - send a notification netlink message | |
1693 | * @sk: netlink socket to use | |
1694 | * @skb: notification message | |
1695 | * @pid: destination netlink pid for reports or 0 | |
1696 | * @group: destination multicast group or 0 | |
1697 | * @report: 1 to report back, 0 to disable | |
1698 | * @flags: allocation flags | |
1699 | */ | |
1700 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid, | |
1701 | unsigned int group, int report, gfp_t flags) | |
1702 | { | |
1703 | int err = 0; | |
1704 | ||
1705 | if (group) { | |
1706 | int exclude_pid = 0; | |
1707 | ||
1708 | if (report) { | |
1709 | atomic_inc(&skb->users); | |
1710 | exclude_pid = pid; | |
1711 | } | |
1712 | ||
1713 | /* errors reported via destination sk->sk_err */ | |
1714 | nlmsg_multicast(sk, skb, exclude_pid, group, flags); | |
1715 | } | |
1716 | ||
1717 | if (report) | |
1718 | err = nlmsg_unicast(sk, skb, pid); | |
1719 | ||
1720 | return err; | |
1721 | } | |
1722 | ||
1da177e4 LT |
1723 | #ifdef CONFIG_PROC_FS |
1724 | struct nl_seq_iter { | |
b4b51029 | 1725 | struct net *net; |
1da177e4 LT |
1726 | int link; |
1727 | int hash_idx; | |
1728 | }; | |
1729 | ||
1730 | static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) | |
1731 | { | |
1732 | struct nl_seq_iter *iter = seq->private; | |
1733 | int i, j; | |
1734 | struct sock *s; | |
1735 | struct hlist_node *node; | |
1736 | loff_t off = 0; | |
1737 | ||
1738 | for (i=0; i<MAX_LINKS; i++) { | |
1739 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1740 | ||
1741 | for (j = 0; j <= hash->mask; j++) { | |
1742 | sk_for_each(s, node, &hash->table[j]) { | |
b4b51029 EB |
1743 | if (iter->net != s->sk_net) |
1744 | continue; | |
1da177e4 LT |
1745 | if (off == pos) { |
1746 | iter->link = i; | |
1747 | iter->hash_idx = j; | |
1748 | return s; | |
1749 | } | |
1750 | ++off; | |
1751 | } | |
1752 | } | |
1753 | } | |
1754 | return NULL; | |
1755 | } | |
1756 | ||
1757 | static void *netlink_seq_start(struct seq_file *seq, loff_t *pos) | |
1758 | { | |
1759 | read_lock(&nl_table_lock); | |
1760 | return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
1761 | } | |
1762 | ||
1763 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
1764 | { | |
1765 | struct sock *s; | |
1766 | struct nl_seq_iter *iter; | |
1767 | int i, j; | |
1768 | ||
1769 | ++*pos; | |
1770 | ||
1771 | if (v == SEQ_START_TOKEN) | |
1772 | return netlink_seq_socket_idx(seq, 0); | |
746fac4d | 1773 | |
b4b51029 EB |
1774 | iter = seq->private; |
1775 | s = v; | |
1776 | do { | |
1777 | s = sk_next(s); | |
1778 | } while (s && (iter->net != s->sk_net)); | |
1da177e4 LT |
1779 | if (s) |
1780 | return s; | |
1781 | ||
1da177e4 LT |
1782 | i = iter->link; |
1783 | j = iter->hash_idx + 1; | |
1784 | ||
1785 | do { | |
1786 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1787 | ||
1788 | for (; j <= hash->mask; j++) { | |
1789 | s = sk_head(&hash->table[j]); | |
b4b51029 EB |
1790 | while (s && (iter->net != s->sk_net)) |
1791 | s = sk_next(s); | |
1da177e4 LT |
1792 | if (s) { |
1793 | iter->link = i; | |
1794 | iter->hash_idx = j; | |
1795 | return s; | |
1796 | } | |
1797 | } | |
1798 | ||
1799 | j = 0; | |
1800 | } while (++i < MAX_LINKS); | |
1801 | ||
1802 | return NULL; | |
1803 | } | |
1804 | ||
1805 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
1806 | { | |
1807 | read_unlock(&nl_table_lock); | |
1808 | } | |
1809 | ||
1810 | ||
1811 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
1812 | { | |
1813 | if (v == SEQ_START_TOKEN) | |
1814 | seq_puts(seq, | |
1815 | "sk Eth Pid Groups " | |
1816 | "Rmem Wmem Dump Locks\n"); | |
1817 | else { | |
1818 | struct sock *s = v; | |
1819 | struct netlink_sock *nlk = nlk_sk(s); | |
1820 | ||
1821 | seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %d\n", | |
1822 | s, | |
1823 | s->sk_protocol, | |
1824 | nlk->pid, | |
513c2500 | 1825 | nlk->groups ? (u32)nlk->groups[0] : 0, |
1da177e4 LT |
1826 | atomic_read(&s->sk_rmem_alloc), |
1827 | atomic_read(&s->sk_wmem_alloc), | |
1828 | nlk->cb, | |
1829 | atomic_read(&s->sk_refcnt) | |
1830 | ); | |
1831 | ||
1832 | } | |
1833 | return 0; | |
1834 | } | |
1835 | ||
56b3d975 | 1836 | static const struct seq_operations netlink_seq_ops = { |
1da177e4 LT |
1837 | .start = netlink_seq_start, |
1838 | .next = netlink_seq_next, | |
1839 | .stop = netlink_seq_stop, | |
1840 | .show = netlink_seq_show, | |
1841 | }; | |
1842 | ||
1843 | ||
1844 | static int netlink_seq_open(struct inode *inode, struct file *file) | |
1845 | { | |
1846 | struct seq_file *seq; | |
1847 | struct nl_seq_iter *iter; | |
1848 | int err; | |
1849 | ||
0da974f4 | 1850 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1da177e4 LT |
1851 | if (!iter) |
1852 | return -ENOMEM; | |
1853 | ||
1854 | err = seq_open(file, &netlink_seq_ops); | |
1855 | if (err) { | |
1856 | kfree(iter); | |
1857 | return err; | |
1858 | } | |
1859 | ||
1da177e4 LT |
1860 | seq = file->private_data; |
1861 | seq->private = iter; | |
b4b51029 | 1862 | iter->net = get_net(PROC_NET(inode)); |
1da177e4 LT |
1863 | return 0; |
1864 | } | |
1865 | ||
b4b51029 EB |
1866 | static int netlink_seq_release(struct inode *inode, struct file *file) |
1867 | { | |
1868 | struct seq_file *seq = file->private_data; | |
1869 | struct nl_seq_iter *iter = seq->private; | |
1870 | put_net(iter->net); | |
1871 | return seq_release_private(inode, file); | |
1872 | } | |
1873 | ||
da7071d7 | 1874 | static const struct file_operations netlink_seq_fops = { |
1da177e4 LT |
1875 | .owner = THIS_MODULE, |
1876 | .open = netlink_seq_open, | |
1877 | .read = seq_read, | |
1878 | .llseek = seq_lseek, | |
b4b51029 | 1879 | .release = netlink_seq_release, |
1da177e4 LT |
1880 | }; |
1881 | ||
1882 | #endif | |
1883 | ||
1884 | int netlink_register_notifier(struct notifier_block *nb) | |
1885 | { | |
e041c683 | 1886 | return atomic_notifier_chain_register(&netlink_chain, nb); |
1da177e4 LT |
1887 | } |
1888 | ||
1889 | int netlink_unregister_notifier(struct notifier_block *nb) | |
1890 | { | |
e041c683 | 1891 | return atomic_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 | 1892 | } |
746fac4d | 1893 | |
90ddc4f0 | 1894 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
1895 | .family = PF_NETLINK, |
1896 | .owner = THIS_MODULE, | |
1897 | .release = netlink_release, | |
1898 | .bind = netlink_bind, | |
1899 | .connect = netlink_connect, | |
1900 | .socketpair = sock_no_socketpair, | |
1901 | .accept = sock_no_accept, | |
1902 | .getname = netlink_getname, | |
1903 | .poll = datagram_poll, | |
1904 | .ioctl = sock_no_ioctl, | |
1905 | .listen = sock_no_listen, | |
1906 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
1907 | .setsockopt = netlink_setsockopt, |
1908 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
1909 | .sendmsg = netlink_sendmsg, |
1910 | .recvmsg = netlink_recvmsg, | |
1911 | .mmap = sock_no_mmap, | |
1912 | .sendpage = sock_no_sendpage, | |
1913 | }; | |
1914 | ||
1915 | static struct net_proto_family netlink_family_ops = { | |
1916 | .family = PF_NETLINK, | |
1917 | .create = netlink_create, | |
1918 | .owner = THIS_MODULE, /* for consistency 8) */ | |
1919 | }; | |
1920 | ||
b4b51029 EB |
1921 | static int netlink_net_init(struct net *net) |
1922 | { | |
1923 | #ifdef CONFIG_PROC_FS | |
1924 | if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops)) | |
1925 | return -ENOMEM; | |
1926 | #endif | |
1927 | return 0; | |
1928 | } | |
1929 | ||
1930 | static void netlink_net_exit(struct net *net) | |
1931 | { | |
1932 | #ifdef CONFIG_PROC_FS | |
1933 | proc_net_remove(net, "netlink"); | |
1934 | #endif | |
1935 | } | |
1936 | ||
1937 | static struct pernet_operations netlink_net_ops = { | |
1938 | .init = netlink_net_init, | |
1939 | .exit = netlink_net_exit, | |
1940 | }; | |
1941 | ||
1da177e4 LT |
1942 | static int __init netlink_proto_init(void) |
1943 | { | |
1944 | struct sk_buff *dummy_skb; | |
1945 | int i; | |
1946 | unsigned long max; | |
1947 | unsigned int order; | |
1948 | int err = proto_register(&netlink_proto, 0); | |
1949 | ||
1950 | if (err != 0) | |
1951 | goto out; | |
1952 | ||
ef047f5e | 1953 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb)); |
1da177e4 | 1954 | |
0da974f4 | 1955 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
1956 | if (!nl_table) |
1957 | goto panic; | |
1da177e4 | 1958 | |
1da177e4 LT |
1959 | if (num_physpages >= (128 * 1024)) |
1960 | max = num_physpages >> (21 - PAGE_SHIFT); | |
1961 | else | |
1962 | max = num_physpages >> (23 - PAGE_SHIFT); | |
1963 | ||
1964 | order = get_bitmask_order(max) - 1 + PAGE_SHIFT; | |
1965 | max = (1UL << order) / sizeof(struct hlist_head); | |
1966 | order = get_bitmask_order(max > UINT_MAX ? UINT_MAX : max) - 1; | |
1967 | ||
1968 | for (i = 0; i < MAX_LINKS; i++) { | |
1969 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1970 | ||
1971 | hash->table = nl_pid_hash_alloc(1 * sizeof(*hash->table)); | |
1972 | if (!hash->table) { | |
1973 | while (i-- > 0) | |
1974 | nl_pid_hash_free(nl_table[i].hash.table, | |
1975 | 1 * sizeof(*hash->table)); | |
1976 | kfree(nl_table); | |
fab2caf6 | 1977 | goto panic; |
1da177e4 LT |
1978 | } |
1979 | memset(hash->table, 0, 1 * sizeof(*hash->table)); | |
1980 | hash->max_shift = order; | |
1981 | hash->shift = 0; | |
1982 | hash->mask = 0; | |
1983 | hash->rehash_time = jiffies; | |
1984 | } | |
1985 | ||
1986 | sock_register(&netlink_family_ops); | |
b4b51029 | 1987 | register_pernet_subsys(&netlink_net_ops); |
746fac4d | 1988 | /* The netlink device handler may be needed early. */ |
1da177e4 LT |
1989 | rtnetlink_init(); |
1990 | out: | |
1991 | return err; | |
fab2caf6 AM |
1992 | panic: |
1993 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
1994 | } |
1995 | ||
1da177e4 | 1996 | core_initcall(netlink_proto_init); |
1da177e4 LT |
1997 | |
1998 | EXPORT_SYMBOL(netlink_ack); | |
82ace47a | 1999 | EXPORT_SYMBOL(netlink_run_queue); |
1da177e4 LT |
2000 | EXPORT_SYMBOL(netlink_broadcast); |
2001 | EXPORT_SYMBOL(netlink_dump_start); | |
2002 | EXPORT_SYMBOL(netlink_kernel_create); | |
2003 | EXPORT_SYMBOL(netlink_register_notifier); | |
1da177e4 LT |
2004 | EXPORT_SYMBOL(netlink_set_nonroot); |
2005 | EXPORT_SYMBOL(netlink_unicast); | |
2006 | EXPORT_SYMBOL(netlink_unregister_notifier); | |
d387f6ad | 2007 | EXPORT_SYMBOL(nlmsg_notify); |