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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; | |
cd40b7d3 | 83 | void (*netlink_rcv)(struct sk_buff *skb); |
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 | ||
aed81560 DL |
95 | static inline int netlink_is_kernel(struct sock *sk) |
96 | { | |
97 | return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET; | |
98 | } | |
99 | ||
1da177e4 LT |
100 | struct nl_pid_hash { |
101 | struct hlist_head *table; | |
102 | unsigned long rehash_time; | |
103 | ||
104 | unsigned int mask; | |
105 | unsigned int shift; | |
106 | ||
107 | unsigned int entries; | |
108 | unsigned int max_shift; | |
109 | ||
110 | u32 rnd; | |
111 | }; | |
112 | ||
113 | struct netlink_table { | |
114 | struct nl_pid_hash hash; | |
115 | struct hlist_head mc_list; | |
4277a083 | 116 | unsigned long *listeners; |
1da177e4 | 117 | unsigned int nl_nonroot; |
f7fa9b10 | 118 | unsigned int groups; |
af65bdfc | 119 | struct mutex *cb_mutex; |
77247bbb | 120 | struct module *module; |
ab33a171 | 121 | int registered; |
1da177e4 LT |
122 | }; |
123 | ||
124 | static struct netlink_table *nl_table; | |
125 | ||
126 | static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); | |
127 | ||
128 | static int netlink_dump(struct sock *sk); | |
129 | static void netlink_destroy_callback(struct netlink_callback *cb); | |
130 | ||
131 | static DEFINE_RWLOCK(nl_table_lock); | |
132 | static atomic_t nl_table_users = ATOMIC_INIT(0); | |
133 | ||
e041c683 | 134 | static ATOMIC_NOTIFIER_HEAD(netlink_chain); |
1da177e4 | 135 | |
d629b836 PM |
136 | static u32 netlink_group_mask(u32 group) |
137 | { | |
138 | return group ? 1 << (group - 1) : 0; | |
139 | } | |
140 | ||
1da177e4 LT |
141 | static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid) |
142 | { | |
143 | return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask]; | |
144 | } | |
145 | ||
146 | static void netlink_sock_destruct(struct sock *sk) | |
147 | { | |
3f660d66 HX |
148 | struct netlink_sock *nlk = nlk_sk(sk); |
149 | ||
3f660d66 HX |
150 | if (nlk->cb) { |
151 | if (nlk->cb->done) | |
152 | nlk->cb->done(nlk->cb); | |
153 | netlink_destroy_callback(nlk->cb); | |
154 | } | |
155 | ||
1da177e4 LT |
156 | skb_queue_purge(&sk->sk_receive_queue); |
157 | ||
158 | if (!sock_flag(sk, SOCK_DEAD)) { | |
6ac552fd | 159 | printk(KERN_ERR "Freeing alive netlink socket %p\n", sk); |
1da177e4 LT |
160 | return; |
161 | } | |
162 | BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc)); | |
163 | BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc)); | |
f7fa9b10 | 164 | BUG_TRAP(!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) | |
174 | { | |
6abd219c | 175 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
176 | |
177 | if (atomic_read(&nl_table_users)) { | |
178 | DECLARE_WAITQUEUE(wait, current); | |
179 | ||
180 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
6ac552fd | 181 | for (;;) { |
1da177e4 LT |
182 | set_current_state(TASK_UNINTERRUPTIBLE); |
183 | if (atomic_read(&nl_table_users) == 0) | |
184 | break; | |
6abd219c | 185 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 186 | schedule(); |
6abd219c | 187 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
188 | } |
189 | ||
190 | __set_current_state(TASK_RUNNING); | |
191 | remove_wait_queue(&nl_table_wait, &wait); | |
192 | } | |
193 | } | |
194 | ||
6ac552fd | 195 | static inline void netlink_table_ungrab(void) |
1da177e4 | 196 | { |
6abd219c | 197 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
198 | wake_up(&nl_table_wait); |
199 | } | |
200 | ||
6ac552fd | 201 | static inline void |
1da177e4 LT |
202 | netlink_lock_table(void) |
203 | { | |
204 | /* read_lock() synchronizes us to netlink_table_grab */ | |
205 | ||
206 | read_lock(&nl_table_lock); | |
207 | atomic_inc(&nl_table_users); | |
208 | read_unlock(&nl_table_lock); | |
209 | } | |
210 | ||
6ac552fd | 211 | static inline void |
1da177e4 LT |
212 | netlink_unlock_table(void) |
213 | { | |
214 | if (atomic_dec_and_test(&nl_table_users)) | |
215 | wake_up(&nl_table_wait); | |
216 | } | |
217 | ||
6ac552fd PM |
218 | static inline struct sock *netlink_lookup(struct net *net, int protocol, |
219 | u32 pid) | |
1da177e4 LT |
220 | { |
221 | struct nl_pid_hash *hash = &nl_table[protocol].hash; | |
222 | struct hlist_head *head; | |
223 | struct sock *sk; | |
224 | struct hlist_node *node; | |
225 | ||
226 | read_lock(&nl_table_lock); | |
227 | head = nl_pid_hashfn(hash, pid); | |
228 | sk_for_each(sk, node, head) { | |
b4b51029 | 229 | if ((sk->sk_net == net) && (nlk_sk(sk)->pid == pid)) { |
1da177e4 LT |
230 | sock_hold(sk); |
231 | goto found; | |
232 | } | |
233 | } | |
234 | sk = NULL; | |
235 | found: | |
236 | read_unlock(&nl_table_lock); | |
237 | return sk; | |
238 | } | |
239 | ||
ea72912c | 240 | static inline struct hlist_head *nl_pid_hash_zalloc(size_t size) |
1da177e4 LT |
241 | { |
242 | if (size <= PAGE_SIZE) | |
ea72912c | 243 | return kzalloc(size, GFP_ATOMIC); |
1da177e4 LT |
244 | else |
245 | return (struct hlist_head *) | |
ea72912c ED |
246 | __get_free_pages(GFP_ATOMIC | __GFP_ZERO, |
247 | get_order(size)); | |
1da177e4 LT |
248 | } |
249 | ||
250 | static inline void nl_pid_hash_free(struct hlist_head *table, size_t size) | |
251 | { | |
252 | if (size <= PAGE_SIZE) | |
253 | kfree(table); | |
254 | else | |
255 | free_pages((unsigned long)table, get_order(size)); | |
256 | } | |
257 | ||
258 | static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow) | |
259 | { | |
260 | unsigned int omask, mask, shift; | |
261 | size_t osize, size; | |
262 | struct hlist_head *otable, *table; | |
263 | int i; | |
264 | ||
265 | omask = mask = hash->mask; | |
266 | osize = size = (mask + 1) * sizeof(*table); | |
267 | shift = hash->shift; | |
268 | ||
269 | if (grow) { | |
270 | if (++shift > hash->max_shift) | |
271 | return 0; | |
272 | mask = mask * 2 + 1; | |
273 | size *= 2; | |
274 | } | |
275 | ||
ea72912c | 276 | table = nl_pid_hash_zalloc(size); |
1da177e4 LT |
277 | if (!table) |
278 | return 0; | |
279 | ||
1da177e4 LT |
280 | otable = hash->table; |
281 | hash->table = table; | |
282 | hash->mask = mask; | |
283 | hash->shift = shift; | |
284 | get_random_bytes(&hash->rnd, sizeof(hash->rnd)); | |
285 | ||
286 | for (i = 0; i <= omask; i++) { | |
287 | struct sock *sk; | |
288 | struct hlist_node *node, *tmp; | |
289 | ||
290 | sk_for_each_safe(sk, node, tmp, &otable[i]) | |
291 | __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid)); | |
292 | } | |
293 | ||
294 | nl_pid_hash_free(otable, osize); | |
295 | hash->rehash_time = jiffies + 10 * 60 * HZ; | |
296 | return 1; | |
297 | } | |
298 | ||
299 | static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len) | |
300 | { | |
301 | int avg = hash->entries >> hash->shift; | |
302 | ||
303 | if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1)) | |
304 | return 1; | |
305 | ||
306 | if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) { | |
307 | nl_pid_hash_rehash(hash, 0); | |
308 | return 1; | |
309 | } | |
310 | ||
311 | return 0; | |
312 | } | |
313 | ||
90ddc4f0 | 314 | static const struct proto_ops netlink_ops; |
1da177e4 | 315 | |
4277a083 PM |
316 | static void |
317 | netlink_update_listeners(struct sock *sk) | |
318 | { | |
319 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
320 | struct hlist_node *node; | |
321 | unsigned long mask; | |
322 | unsigned int i; | |
323 | ||
b4ff4f04 | 324 | for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
4277a083 | 325 | mask = 0; |
b4ff4f04 JB |
326 | sk_for_each_bound(sk, node, &tbl->mc_list) { |
327 | if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) | |
328 | mask |= nlk_sk(sk)->groups[i]; | |
329 | } | |
4277a083 PM |
330 | tbl->listeners[i] = mask; |
331 | } | |
332 | /* this function is only called with the netlink table "grabbed", which | |
333 | * makes sure updates are visible before bind or setsockopt return. */ | |
334 | } | |
335 | ||
b4b51029 | 336 | static int netlink_insert(struct sock *sk, struct net *net, u32 pid) |
1da177e4 LT |
337 | { |
338 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; | |
339 | struct hlist_head *head; | |
340 | int err = -EADDRINUSE; | |
341 | struct sock *osk; | |
342 | struct hlist_node *node; | |
343 | int len; | |
344 | ||
345 | netlink_table_grab(); | |
346 | head = nl_pid_hashfn(hash, pid); | |
347 | len = 0; | |
348 | sk_for_each(osk, node, head) { | |
b4b51029 | 349 | if ((osk->sk_net == net) && (nlk_sk(osk)->pid == pid)) |
1da177e4 LT |
350 | break; |
351 | len++; | |
352 | } | |
353 | if (node) | |
354 | goto err; | |
355 | ||
356 | err = -EBUSY; | |
357 | if (nlk_sk(sk)->pid) | |
358 | goto err; | |
359 | ||
360 | err = -ENOMEM; | |
361 | if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX)) | |
362 | goto err; | |
363 | ||
364 | if (len && nl_pid_hash_dilute(hash, len)) | |
365 | head = nl_pid_hashfn(hash, pid); | |
366 | hash->entries++; | |
367 | nlk_sk(sk)->pid = pid; | |
368 | sk_add_node(sk, head); | |
369 | err = 0; | |
370 | ||
371 | err: | |
372 | netlink_table_ungrab(); | |
373 | return err; | |
374 | } | |
375 | ||
376 | static void netlink_remove(struct sock *sk) | |
377 | { | |
378 | netlink_table_grab(); | |
d470e3b4 DM |
379 | if (sk_del_node_init(sk)) |
380 | nl_table[sk->sk_protocol].hash.entries--; | |
f7fa9b10 | 381 | if (nlk_sk(sk)->subscriptions) |
1da177e4 LT |
382 | __sk_del_bind_node(sk); |
383 | netlink_table_ungrab(); | |
384 | } | |
385 | ||
386 | static struct proto netlink_proto = { | |
387 | .name = "NETLINK", | |
388 | .owner = THIS_MODULE, | |
389 | .obj_size = sizeof(struct netlink_sock), | |
390 | }; | |
391 | ||
1b8d7ae4 EB |
392 | static int __netlink_create(struct net *net, struct socket *sock, |
393 | struct mutex *cb_mutex, int protocol) | |
1da177e4 LT |
394 | { |
395 | struct sock *sk; | |
396 | struct netlink_sock *nlk; | |
ab33a171 PM |
397 | |
398 | sock->ops = &netlink_ops; | |
399 | ||
6257ff21 | 400 | sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto); |
ab33a171 PM |
401 | if (!sk) |
402 | return -ENOMEM; | |
403 | ||
404 | sock_init_data(sock, sk); | |
405 | ||
406 | nlk = nlk_sk(sk); | |
ffa4d721 PM |
407 | if (cb_mutex) |
408 | nlk->cb_mutex = cb_mutex; | |
409 | else { | |
410 | nlk->cb_mutex = &nlk->cb_def_mutex; | |
411 | mutex_init(nlk->cb_mutex); | |
412 | } | |
ab33a171 PM |
413 | init_waitqueue_head(&nlk->wait); |
414 | ||
415 | sk->sk_destruct = netlink_sock_destruct; | |
416 | sk->sk_protocol = protocol; | |
417 | return 0; | |
418 | } | |
419 | ||
1b8d7ae4 | 420 | static int netlink_create(struct net *net, struct socket *sock, int protocol) |
ab33a171 PM |
421 | { |
422 | struct module *module = NULL; | |
af65bdfc | 423 | struct mutex *cb_mutex; |
f7fa9b10 | 424 | struct netlink_sock *nlk; |
ab33a171 | 425 | int err = 0; |
1da177e4 LT |
426 | |
427 | sock->state = SS_UNCONNECTED; | |
428 | ||
429 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
430 | return -ESOCKTNOSUPPORT; | |
431 | ||
6ac552fd | 432 | if (protocol < 0 || protocol >= MAX_LINKS) |
1da177e4 LT |
433 | return -EPROTONOSUPPORT; |
434 | ||
77247bbb | 435 | netlink_lock_table(); |
4fdb3bb7 | 436 | #ifdef CONFIG_KMOD |
ab33a171 | 437 | if (!nl_table[protocol].registered) { |
77247bbb | 438 | netlink_unlock_table(); |
4fdb3bb7 | 439 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 440 | netlink_lock_table(); |
4fdb3bb7 | 441 | } |
ab33a171 PM |
442 | #endif |
443 | if (nl_table[protocol].registered && | |
444 | try_module_get(nl_table[protocol].module)) | |
445 | module = nl_table[protocol].module; | |
af65bdfc | 446 | cb_mutex = nl_table[protocol].cb_mutex; |
77247bbb | 447 | netlink_unlock_table(); |
4fdb3bb7 | 448 | |
6ac552fd PM |
449 | err = __netlink_create(net, sock, cb_mutex, protocol); |
450 | if (err < 0) | |
f7fa9b10 PM |
451 | goto out_module; |
452 | ||
453 | nlk = nlk_sk(sock->sk); | |
f7fa9b10 | 454 | nlk->module = module; |
ab33a171 PM |
455 | out: |
456 | return err; | |
1da177e4 | 457 | |
ab33a171 PM |
458 | out_module: |
459 | module_put(module); | |
460 | goto out; | |
1da177e4 LT |
461 | } |
462 | ||
463 | static int netlink_release(struct socket *sock) | |
464 | { | |
465 | struct sock *sk = sock->sk; | |
466 | struct netlink_sock *nlk; | |
467 | ||
468 | if (!sk) | |
469 | return 0; | |
470 | ||
471 | netlink_remove(sk); | |
ac57b3a9 | 472 | sock_orphan(sk); |
1da177e4 LT |
473 | nlk = nlk_sk(sk); |
474 | ||
3f660d66 HX |
475 | /* |
476 | * OK. Socket is unlinked, any packets that arrive now | |
477 | * will be purged. | |
478 | */ | |
1da177e4 | 479 | |
1da177e4 LT |
480 | sock->sk = NULL; |
481 | wake_up_interruptible_all(&nlk->wait); | |
482 | ||
483 | skb_queue_purge(&sk->sk_write_queue); | |
484 | ||
f7fa9b10 | 485 | if (nlk->pid && !nlk->subscriptions) { |
1da177e4 | 486 | struct netlink_notify n = { |
b4b51029 | 487 | .net = sk->sk_net, |
1da177e4 LT |
488 | .protocol = sk->sk_protocol, |
489 | .pid = nlk->pid, | |
490 | }; | |
e041c683 AS |
491 | atomic_notifier_call_chain(&netlink_chain, |
492 | NETLINK_URELEASE, &n); | |
746fac4d | 493 | } |
4fdb3bb7 | 494 | |
5e7c001c | 495 | module_put(nlk->module); |
4fdb3bb7 | 496 | |
4277a083 | 497 | netlink_table_grab(); |
aed81560 | 498 | if (netlink_is_kernel(sk)) { |
4277a083 | 499 | kfree(nl_table[sk->sk_protocol].listeners); |
77247bbb | 500 | nl_table[sk->sk_protocol].module = NULL; |
ab33a171 | 501 | nl_table[sk->sk_protocol].registered = 0; |
4277a083 PM |
502 | } else if (nlk->subscriptions) |
503 | netlink_update_listeners(sk); | |
504 | netlink_table_ungrab(); | |
77247bbb | 505 | |
f7fa9b10 PM |
506 | kfree(nlk->groups); |
507 | nlk->groups = NULL; | |
508 | ||
1da177e4 LT |
509 | sock_put(sk); |
510 | return 0; | |
511 | } | |
512 | ||
513 | static int netlink_autobind(struct socket *sock) | |
514 | { | |
515 | struct sock *sk = sock->sk; | |
b4b51029 | 516 | struct net *net = sk->sk_net; |
1da177e4 LT |
517 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; |
518 | struct hlist_head *head; | |
519 | struct sock *osk; | |
520 | struct hlist_node *node; | |
c27bd492 | 521 | s32 pid = current->tgid; |
1da177e4 LT |
522 | int err; |
523 | static s32 rover = -4097; | |
524 | ||
525 | retry: | |
526 | cond_resched(); | |
527 | netlink_table_grab(); | |
528 | head = nl_pid_hashfn(hash, pid); | |
529 | sk_for_each(osk, node, head) { | |
b4b51029 EB |
530 | if ((osk->sk_net != net)) |
531 | continue; | |
1da177e4 LT |
532 | if (nlk_sk(osk)->pid == pid) { |
533 | /* Bind collision, search negative pid values. */ | |
534 | pid = rover--; | |
535 | if (rover > -4097) | |
536 | rover = -4097; | |
537 | netlink_table_ungrab(); | |
538 | goto retry; | |
539 | } | |
540 | } | |
541 | netlink_table_ungrab(); | |
542 | ||
b4b51029 | 543 | err = netlink_insert(sk, net, pid); |
1da177e4 LT |
544 | if (err == -EADDRINUSE) |
545 | goto retry; | |
d470e3b4 DM |
546 | |
547 | /* If 2 threads race to autobind, that is fine. */ | |
548 | if (err == -EBUSY) | |
549 | err = 0; | |
550 | ||
551 | return err; | |
1da177e4 LT |
552 | } |
553 | ||
746fac4d YH |
554 | static inline int netlink_capable(struct socket *sock, unsigned int flag) |
555 | { | |
1da177e4 LT |
556 | return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) || |
557 | capable(CAP_NET_ADMIN); | |
746fac4d | 558 | } |
1da177e4 | 559 | |
f7fa9b10 PM |
560 | static void |
561 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
562 | { | |
563 | struct netlink_sock *nlk = nlk_sk(sk); | |
564 | ||
565 | if (nlk->subscriptions && !subscriptions) | |
566 | __sk_del_bind_node(sk); | |
567 | else if (!nlk->subscriptions && subscriptions) | |
568 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
569 | nlk->subscriptions = subscriptions; | |
570 | } | |
571 | ||
b4ff4f04 | 572 | static int netlink_realloc_groups(struct sock *sk) |
513c2500 PM |
573 | { |
574 | struct netlink_sock *nlk = nlk_sk(sk); | |
575 | unsigned int groups; | |
b4ff4f04 | 576 | unsigned long *new_groups; |
513c2500 PM |
577 | int err = 0; |
578 | ||
b4ff4f04 JB |
579 | netlink_table_grab(); |
580 | ||
513c2500 | 581 | groups = nl_table[sk->sk_protocol].groups; |
b4ff4f04 | 582 | if (!nl_table[sk->sk_protocol].registered) { |
513c2500 | 583 | err = -ENOENT; |
b4ff4f04 JB |
584 | goto out_unlock; |
585 | } | |
513c2500 | 586 | |
b4ff4f04 JB |
587 | if (nlk->ngroups >= groups) |
588 | goto out_unlock; | |
513c2500 | 589 | |
b4ff4f04 JB |
590 | new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
591 | if (new_groups == NULL) { | |
592 | err = -ENOMEM; | |
593 | goto out_unlock; | |
594 | } | |
6ac552fd | 595 | memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, |
b4ff4f04 JB |
596 | NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); |
597 | ||
598 | nlk->groups = new_groups; | |
513c2500 | 599 | nlk->ngroups = groups; |
b4ff4f04 JB |
600 | out_unlock: |
601 | netlink_table_ungrab(); | |
602 | return err; | |
513c2500 PM |
603 | } |
604 | ||
6ac552fd PM |
605 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, |
606 | int addr_len) | |
1da177e4 LT |
607 | { |
608 | struct sock *sk = sock->sk; | |
b4b51029 | 609 | struct net *net = sk->sk_net; |
1da177e4 LT |
610 | struct netlink_sock *nlk = nlk_sk(sk); |
611 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
612 | int err; | |
746fac4d | 613 | |
1da177e4 LT |
614 | if (nladdr->nl_family != AF_NETLINK) |
615 | return -EINVAL; | |
616 | ||
617 | /* Only superuser is allowed to listen multicasts */ | |
513c2500 PM |
618 | if (nladdr->nl_groups) { |
619 | if (!netlink_capable(sock, NL_NONROOT_RECV)) | |
620 | return -EPERM; | |
b4ff4f04 JB |
621 | err = netlink_realloc_groups(sk); |
622 | if (err) | |
623 | return err; | |
513c2500 | 624 | } |
1da177e4 LT |
625 | |
626 | if (nlk->pid) { | |
627 | if (nladdr->nl_pid != nlk->pid) | |
628 | return -EINVAL; | |
629 | } else { | |
630 | err = nladdr->nl_pid ? | |
b4b51029 | 631 | netlink_insert(sk, net, nladdr->nl_pid) : |
1da177e4 LT |
632 | netlink_autobind(sock); |
633 | if (err) | |
634 | return err; | |
635 | } | |
636 | ||
513c2500 | 637 | if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
1da177e4 LT |
638 | return 0; |
639 | ||
640 | netlink_table_grab(); | |
f7fa9b10 | 641 | netlink_update_subscriptions(sk, nlk->subscriptions + |
746fac4d YH |
642 | hweight32(nladdr->nl_groups) - |
643 | hweight32(nlk->groups[0])); | |
644 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups; | |
4277a083 | 645 | netlink_update_listeners(sk); |
1da177e4 LT |
646 | netlink_table_ungrab(); |
647 | ||
648 | return 0; | |
649 | } | |
650 | ||
651 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
652 | int alen, int flags) | |
653 | { | |
654 | int err = 0; | |
655 | struct sock *sk = sock->sk; | |
656 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 657 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
1da177e4 LT |
658 | |
659 | if (addr->sa_family == AF_UNSPEC) { | |
660 | sk->sk_state = NETLINK_UNCONNECTED; | |
661 | nlk->dst_pid = 0; | |
d629b836 | 662 | nlk->dst_group = 0; |
1da177e4 LT |
663 | return 0; |
664 | } | |
665 | if (addr->sa_family != AF_NETLINK) | |
666 | return -EINVAL; | |
667 | ||
668 | /* Only superuser is allowed to send multicasts */ | |
669 | if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND)) | |
670 | return -EPERM; | |
671 | ||
672 | if (!nlk->pid) | |
673 | err = netlink_autobind(sock); | |
674 | ||
675 | if (err == 0) { | |
676 | sk->sk_state = NETLINK_CONNECTED; | |
677 | nlk->dst_pid = nladdr->nl_pid; | |
d629b836 | 678 | nlk->dst_group = ffs(nladdr->nl_groups); |
1da177e4 LT |
679 | } |
680 | ||
681 | return err; | |
682 | } | |
683 | ||
6ac552fd PM |
684 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, |
685 | int *addr_len, int peer) | |
1da177e4 LT |
686 | { |
687 | struct sock *sk = sock->sk; | |
688 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 689 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
746fac4d | 690 | |
1da177e4 LT |
691 | nladdr->nl_family = AF_NETLINK; |
692 | nladdr->nl_pad = 0; | |
693 | *addr_len = sizeof(*nladdr); | |
694 | ||
695 | if (peer) { | |
696 | nladdr->nl_pid = nlk->dst_pid; | |
d629b836 | 697 | nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
1da177e4 LT |
698 | } else { |
699 | nladdr->nl_pid = nlk->pid; | |
513c2500 | 700 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
1da177e4 LT |
701 | } |
702 | return 0; | |
703 | } | |
704 | ||
705 | static void netlink_overrun(struct sock *sk) | |
706 | { | |
707 | if (!test_and_set_bit(0, &nlk_sk(sk)->state)) { | |
708 | sk->sk_err = ENOBUFS; | |
709 | sk->sk_error_report(sk); | |
710 | } | |
711 | } | |
712 | ||
713 | static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid) | |
714 | { | |
1da177e4 LT |
715 | struct sock *sock; |
716 | struct netlink_sock *nlk; | |
717 | ||
cd40b7d3 | 718 | sock = netlink_lookup(ssk->sk_net, ssk->sk_protocol, pid); |
1da177e4 LT |
719 | if (!sock) |
720 | return ERR_PTR(-ECONNREFUSED); | |
721 | ||
722 | /* Don't bother queuing skb if kernel socket has no input function */ | |
723 | nlk = nlk_sk(sock); | |
cd40b7d3 DL |
724 | if (sock->sk_state == NETLINK_CONNECTED && |
725 | nlk->dst_pid != nlk_sk(ssk)->pid) { | |
1da177e4 LT |
726 | sock_put(sock); |
727 | return ERR_PTR(-ECONNREFUSED); | |
728 | } | |
729 | return sock; | |
730 | } | |
731 | ||
732 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
733 | { | |
6db5fc5d | 734 | struct inode *inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
735 | struct sock *sock; |
736 | ||
737 | if (!S_ISSOCK(inode->i_mode)) | |
738 | return ERR_PTR(-ENOTSOCK); | |
739 | ||
740 | sock = SOCKET_I(inode)->sk; | |
741 | if (sock->sk_family != AF_NETLINK) | |
742 | return ERR_PTR(-EINVAL); | |
743 | ||
744 | sock_hold(sock); | |
745 | return sock; | |
746 | } | |
747 | ||
748 | /* | |
749 | * Attach a skb to a netlink socket. | |
750 | * The caller must hold a reference to the destination socket. On error, the | |
751 | * reference is dropped. The skb is not send to the destination, just all | |
752 | * all error checks are performed and memory in the queue is reserved. | |
753 | * Return values: | |
754 | * < 0: error. skb freed, reference to sock dropped. | |
755 | * 0: continue | |
756 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
757 | */ | |
a70ea994 | 758 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock, |
c3d8d1e3 | 759 | long *timeo, struct sock *ssk) |
1da177e4 LT |
760 | { |
761 | struct netlink_sock *nlk; | |
762 | ||
763 | nlk = nlk_sk(sk); | |
764 | ||
765 | if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
766 | test_bit(0, &nlk->state)) { | |
767 | DECLARE_WAITQUEUE(wait, current); | |
c3d8d1e3 | 768 | if (!*timeo) { |
aed81560 | 769 | if (!ssk || netlink_is_kernel(ssk)) |
1da177e4 LT |
770 | netlink_overrun(sk); |
771 | sock_put(sk); | |
772 | kfree_skb(skb); | |
773 | return -EAGAIN; | |
774 | } | |
775 | ||
776 | __set_current_state(TASK_INTERRUPTIBLE); | |
777 | add_wait_queue(&nlk->wait, &wait); | |
778 | ||
779 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
780 | test_bit(0, &nlk->state)) && | |
781 | !sock_flag(sk, SOCK_DEAD)) | |
c3d8d1e3 | 782 | *timeo = schedule_timeout(*timeo); |
1da177e4 LT |
783 | |
784 | __set_current_state(TASK_RUNNING); | |
785 | remove_wait_queue(&nlk->wait, &wait); | |
786 | sock_put(sk); | |
787 | ||
788 | if (signal_pending(current)) { | |
789 | kfree_skb(skb); | |
c3d8d1e3 | 790 | return sock_intr_errno(*timeo); |
1da177e4 LT |
791 | } |
792 | return 1; | |
793 | } | |
794 | skb_set_owner_r(skb, sk); | |
795 | return 0; | |
796 | } | |
797 | ||
7ee015e0 | 798 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 799 | { |
1da177e4 LT |
800 | int len = skb->len; |
801 | ||
1da177e4 LT |
802 | skb_queue_tail(&sk->sk_receive_queue, skb); |
803 | sk->sk_data_ready(sk, len); | |
804 | sock_put(sk); | |
805 | return len; | |
806 | } | |
807 | ||
808 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
809 | { | |
810 | kfree_skb(skb); | |
811 | sock_put(sk); | |
812 | } | |
813 | ||
37da647d | 814 | static inline struct sk_buff *netlink_trim(struct sk_buff *skb, |
dd0fc66f | 815 | gfp_t allocation) |
1da177e4 LT |
816 | { |
817 | int delta; | |
818 | ||
819 | skb_orphan(skb); | |
820 | ||
4305b541 | 821 | delta = skb->end - skb->tail; |
1da177e4 LT |
822 | if (delta * 2 < skb->truesize) |
823 | return skb; | |
824 | ||
825 | if (skb_shared(skb)) { | |
826 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
827 | if (!nskb) | |
828 | return skb; | |
829 | kfree_skb(skb); | |
830 | skb = nskb; | |
831 | } | |
832 | ||
833 | if (!pskb_expand_head(skb, 0, -delta, allocation)) | |
834 | skb->truesize -= delta; | |
835 | ||
836 | return skb; | |
837 | } | |
838 | ||
cd40b7d3 DL |
839 | static inline void netlink_rcv_wake(struct sock *sk) |
840 | { | |
841 | struct netlink_sock *nlk = nlk_sk(sk); | |
842 | ||
843 | if (skb_queue_empty(&sk->sk_receive_queue)) | |
844 | clear_bit(0, &nlk->state); | |
845 | if (!test_bit(0, &nlk->state)) | |
846 | wake_up_interruptible(&nlk->wait); | |
847 | } | |
848 | ||
849 | static inline int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb) | |
850 | { | |
851 | int ret; | |
852 | struct netlink_sock *nlk = nlk_sk(sk); | |
853 | ||
854 | ret = -ECONNREFUSED; | |
855 | if (nlk->netlink_rcv != NULL) { | |
856 | ret = skb->len; | |
857 | skb_set_owner_r(skb, sk); | |
858 | nlk->netlink_rcv(skb); | |
859 | } | |
860 | kfree_skb(skb); | |
861 | sock_put(sk); | |
862 | return ret; | |
863 | } | |
864 | ||
865 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, | |
866 | u32 pid, int nonblock) | |
1da177e4 LT |
867 | { |
868 | struct sock *sk; | |
869 | int err; | |
870 | long timeo; | |
871 | ||
872 | skb = netlink_trim(skb, gfp_any()); | |
873 | ||
874 | timeo = sock_sndtimeo(ssk, nonblock); | |
875 | retry: | |
876 | sk = netlink_getsockbypid(ssk, pid); | |
877 | if (IS_ERR(sk)) { | |
878 | kfree_skb(skb); | |
879 | return PTR_ERR(sk); | |
880 | } | |
cd40b7d3 DL |
881 | if (netlink_is_kernel(sk)) |
882 | return netlink_unicast_kernel(sk, skb); | |
883 | ||
c3d8d1e3 | 884 | err = netlink_attachskb(sk, skb, nonblock, &timeo, ssk); |
1da177e4 LT |
885 | if (err == 1) |
886 | goto retry; | |
887 | if (err) | |
888 | return err; | |
889 | ||
7ee015e0 | 890 | return netlink_sendskb(sk, skb); |
1da177e4 | 891 | } |
6ac552fd | 892 | EXPORT_SYMBOL(netlink_unicast); |
1da177e4 | 893 | |
4277a083 PM |
894 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
895 | { | |
896 | int res = 0; | |
b4ff4f04 | 897 | unsigned long *listeners; |
4277a083 | 898 | |
aed81560 | 899 | BUG_ON(!netlink_is_kernel(sk)); |
b4ff4f04 JB |
900 | |
901 | rcu_read_lock(); | |
902 | listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); | |
903 | ||
4277a083 | 904 | if (group - 1 < nl_table[sk->sk_protocol].groups) |
b4ff4f04 JB |
905 | res = test_bit(group - 1, listeners); |
906 | ||
907 | rcu_read_unlock(); | |
908 | ||
4277a083 PM |
909 | return res; |
910 | } | |
911 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
912 | ||
6ac552fd PM |
913 | static inline int netlink_broadcast_deliver(struct sock *sk, |
914 | struct sk_buff *skb) | |
1da177e4 LT |
915 | { |
916 | struct netlink_sock *nlk = nlk_sk(sk); | |
917 | ||
918 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
919 | !test_bit(0, &nlk->state)) { | |
920 | skb_set_owner_r(skb, sk); | |
921 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
922 | sk->sk_data_ready(sk, skb->len); | |
923 | return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf; | |
924 | } | |
925 | return -1; | |
926 | } | |
927 | ||
928 | struct netlink_broadcast_data { | |
929 | struct sock *exclude_sk; | |
b4b51029 | 930 | struct net *net; |
1da177e4 LT |
931 | u32 pid; |
932 | u32 group; | |
933 | int failure; | |
934 | int congested; | |
935 | int delivered; | |
7d877f3b | 936 | gfp_t allocation; |
1da177e4 LT |
937 | struct sk_buff *skb, *skb2; |
938 | }; | |
939 | ||
940 | static inline int do_one_broadcast(struct sock *sk, | |
941 | struct netlink_broadcast_data *p) | |
942 | { | |
943 | struct netlink_sock *nlk = nlk_sk(sk); | |
944 | int val; | |
945 | ||
946 | if (p->exclude_sk == sk) | |
947 | goto out; | |
948 | ||
f7fa9b10 PM |
949 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
950 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
951 | goto out; |
952 | ||
b4b51029 EB |
953 | if ((sk->sk_net != p->net)) |
954 | goto out; | |
955 | ||
1da177e4 LT |
956 | if (p->failure) { |
957 | netlink_overrun(sk); | |
958 | goto out; | |
959 | } | |
960 | ||
961 | sock_hold(sk); | |
962 | if (p->skb2 == NULL) { | |
68acc024 | 963 | if (skb_shared(p->skb)) { |
1da177e4 LT |
964 | p->skb2 = skb_clone(p->skb, p->allocation); |
965 | } else { | |
68acc024 TC |
966 | p->skb2 = skb_get(p->skb); |
967 | /* | |
968 | * skb ownership may have been set when | |
969 | * delivered to a previous socket. | |
970 | */ | |
971 | skb_orphan(p->skb2); | |
1da177e4 LT |
972 | } |
973 | } | |
974 | if (p->skb2 == NULL) { | |
975 | netlink_overrun(sk); | |
976 | /* Clone failed. Notify ALL listeners. */ | |
977 | p->failure = 1; | |
978 | } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) { | |
979 | netlink_overrun(sk); | |
980 | } else { | |
981 | p->congested |= val; | |
982 | p->delivered = 1; | |
983 | p->skb2 = NULL; | |
984 | } | |
985 | sock_put(sk); | |
986 | ||
987 | out: | |
988 | return 0; | |
989 | } | |
990 | ||
991 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid, | |
dd0fc66f | 992 | u32 group, gfp_t allocation) |
1da177e4 | 993 | { |
b4b51029 | 994 | struct net *net = ssk->sk_net; |
1da177e4 LT |
995 | struct netlink_broadcast_data info; |
996 | struct hlist_node *node; | |
997 | struct sock *sk; | |
998 | ||
999 | skb = netlink_trim(skb, allocation); | |
1000 | ||
1001 | info.exclude_sk = ssk; | |
b4b51029 | 1002 | info.net = net; |
1da177e4 LT |
1003 | info.pid = pid; |
1004 | info.group = group; | |
1005 | info.failure = 0; | |
1006 | info.congested = 0; | |
1007 | info.delivered = 0; | |
1008 | info.allocation = allocation; | |
1009 | info.skb = skb; | |
1010 | info.skb2 = NULL; | |
1011 | ||
1012 | /* While we sleep in clone, do not allow to change socket list */ | |
1013 | ||
1014 | netlink_lock_table(); | |
1015 | ||
1016 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1017 | do_one_broadcast(sk, &info); | |
1018 | ||
aa1c6a6f TC |
1019 | kfree_skb(skb); |
1020 | ||
1da177e4 LT |
1021 | netlink_unlock_table(); |
1022 | ||
1023 | if (info.skb2) | |
1024 | kfree_skb(info.skb2); | |
1da177e4 LT |
1025 | |
1026 | if (info.delivered) { | |
1027 | if (info.congested && (allocation & __GFP_WAIT)) | |
1028 | yield(); | |
1029 | return 0; | |
1030 | } | |
1031 | if (info.failure) | |
1032 | return -ENOBUFS; | |
1033 | return -ESRCH; | |
1034 | } | |
6ac552fd | 1035 | EXPORT_SYMBOL(netlink_broadcast); |
1da177e4 LT |
1036 | |
1037 | struct netlink_set_err_data { | |
1038 | struct sock *exclude_sk; | |
1039 | u32 pid; | |
1040 | u32 group; | |
1041 | int code; | |
1042 | }; | |
1043 | ||
1044 | static inline int do_one_set_err(struct sock *sk, | |
1045 | struct netlink_set_err_data *p) | |
1046 | { | |
1047 | struct netlink_sock *nlk = nlk_sk(sk); | |
1048 | ||
1049 | if (sk == p->exclude_sk) | |
1050 | goto out; | |
1051 | ||
b4b51029 EB |
1052 | if (sk->sk_net != p->exclude_sk->sk_net) |
1053 | goto out; | |
1054 | ||
f7fa9b10 PM |
1055 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
1056 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
1057 | goto out; |
1058 | ||
1059 | sk->sk_err = p->code; | |
1060 | sk->sk_error_report(sk); | |
1061 | out: | |
1062 | return 0; | |
1063 | } | |
1064 | ||
1065 | void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) | |
1066 | { | |
1067 | struct netlink_set_err_data info; | |
1068 | struct hlist_node *node; | |
1069 | struct sock *sk; | |
1070 | ||
1071 | info.exclude_sk = ssk; | |
1072 | info.pid = pid; | |
1073 | info.group = group; | |
1074 | info.code = code; | |
1075 | ||
1076 | read_lock(&nl_table_lock); | |
1077 | ||
1078 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1079 | do_one_set_err(sk, &info); | |
1080 | ||
1081 | read_unlock(&nl_table_lock); | |
1082 | } | |
1083 | ||
84659eb5 JB |
1084 | /* must be called with netlink table grabbed */ |
1085 | static void netlink_update_socket_mc(struct netlink_sock *nlk, | |
1086 | unsigned int group, | |
1087 | int is_new) | |
1088 | { | |
1089 | int old, new = !!is_new, subscriptions; | |
1090 | ||
1091 | old = test_bit(group - 1, nlk->groups); | |
1092 | subscriptions = nlk->subscriptions - old + new; | |
1093 | if (new) | |
1094 | __set_bit(group - 1, nlk->groups); | |
1095 | else | |
1096 | __clear_bit(group - 1, nlk->groups); | |
1097 | netlink_update_subscriptions(&nlk->sk, subscriptions); | |
1098 | netlink_update_listeners(&nlk->sk); | |
1099 | } | |
1100 | ||
9a4595bc | 1101 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
746fac4d | 1102 | char __user *optval, int optlen) |
9a4595bc PM |
1103 | { |
1104 | struct sock *sk = sock->sk; | |
1105 | struct netlink_sock *nlk = nlk_sk(sk); | |
eb496534 JB |
1106 | unsigned int val = 0; |
1107 | int err; | |
9a4595bc PM |
1108 | |
1109 | if (level != SOL_NETLINK) | |
1110 | return -ENOPROTOOPT; | |
1111 | ||
1112 | if (optlen >= sizeof(int) && | |
eb496534 | 1113 | get_user(val, (unsigned int __user *)optval)) |
9a4595bc PM |
1114 | return -EFAULT; |
1115 | ||
1116 | switch (optname) { | |
1117 | case NETLINK_PKTINFO: | |
1118 | if (val) | |
1119 | nlk->flags |= NETLINK_RECV_PKTINFO; | |
1120 | else | |
1121 | nlk->flags &= ~NETLINK_RECV_PKTINFO; | |
1122 | err = 0; | |
1123 | break; | |
1124 | case NETLINK_ADD_MEMBERSHIP: | |
1125 | case NETLINK_DROP_MEMBERSHIP: { | |
9a4595bc PM |
1126 | if (!netlink_capable(sock, NL_NONROOT_RECV)) |
1127 | return -EPERM; | |
b4ff4f04 JB |
1128 | err = netlink_realloc_groups(sk); |
1129 | if (err) | |
1130 | return err; | |
9a4595bc PM |
1131 | if (!val || val - 1 >= nlk->ngroups) |
1132 | return -EINVAL; | |
1133 | netlink_table_grab(); | |
84659eb5 JB |
1134 | netlink_update_socket_mc(nlk, val, |
1135 | optname == NETLINK_ADD_MEMBERSHIP); | |
9a4595bc PM |
1136 | netlink_table_ungrab(); |
1137 | err = 0; | |
1138 | break; | |
1139 | } | |
1140 | default: | |
1141 | err = -ENOPROTOOPT; | |
1142 | } | |
1143 | return err; | |
1144 | } | |
1145 | ||
1146 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
746fac4d | 1147 | char __user *optval, int __user *optlen) |
9a4595bc PM |
1148 | { |
1149 | struct sock *sk = sock->sk; | |
1150 | struct netlink_sock *nlk = nlk_sk(sk); | |
1151 | int len, val, err; | |
1152 | ||
1153 | if (level != SOL_NETLINK) | |
1154 | return -ENOPROTOOPT; | |
1155 | ||
1156 | if (get_user(len, optlen)) | |
1157 | return -EFAULT; | |
1158 | if (len < 0) | |
1159 | return -EINVAL; | |
1160 | ||
1161 | switch (optname) { | |
1162 | case NETLINK_PKTINFO: | |
1163 | if (len < sizeof(int)) | |
1164 | return -EINVAL; | |
1165 | len = sizeof(int); | |
1166 | val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0; | |
a27b58fe HC |
1167 | if (put_user(len, optlen) || |
1168 | put_user(val, optval)) | |
1169 | return -EFAULT; | |
9a4595bc PM |
1170 | err = 0; |
1171 | break; | |
1172 | default: | |
1173 | err = -ENOPROTOOPT; | |
1174 | } | |
1175 | return err; | |
1176 | } | |
1177 | ||
1178 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
1179 | { | |
1180 | struct nl_pktinfo info; | |
1181 | ||
1182 | info.group = NETLINK_CB(skb).dst_group; | |
1183 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
1184 | } | |
1185 | ||
1da177e4 LT |
1186 | static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, |
1187 | struct msghdr *msg, size_t len) | |
1188 | { | |
1189 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1190 | struct sock *sk = sock->sk; | |
1191 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 1192 | struct sockaddr_nl *addr = msg->msg_name; |
1da177e4 | 1193 | u32 dst_pid; |
d629b836 | 1194 | u32 dst_group; |
1da177e4 LT |
1195 | struct sk_buff *skb; |
1196 | int err; | |
1197 | struct scm_cookie scm; | |
1198 | ||
1199 | if (msg->msg_flags&MSG_OOB) | |
1200 | return -EOPNOTSUPP; | |
1201 | ||
1202 | if (NULL == siocb->scm) | |
1203 | siocb->scm = &scm; | |
1204 | err = scm_send(sock, msg, siocb->scm); | |
1205 | if (err < 0) | |
1206 | return err; | |
1207 | ||
1208 | if (msg->msg_namelen) { | |
1209 | if (addr->nl_family != AF_NETLINK) | |
1210 | return -EINVAL; | |
1211 | dst_pid = addr->nl_pid; | |
d629b836 PM |
1212 | dst_group = ffs(addr->nl_groups); |
1213 | if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND)) | |
1da177e4 LT |
1214 | return -EPERM; |
1215 | } else { | |
1216 | dst_pid = nlk->dst_pid; | |
d629b836 | 1217 | dst_group = nlk->dst_group; |
1da177e4 LT |
1218 | } |
1219 | ||
1220 | if (!nlk->pid) { | |
1221 | err = netlink_autobind(sock); | |
1222 | if (err) | |
1223 | goto out; | |
1224 | } | |
1225 | ||
1226 | err = -EMSGSIZE; | |
1227 | if (len > sk->sk_sndbuf - 32) | |
1228 | goto out; | |
1229 | err = -ENOBUFS; | |
339bf98f | 1230 | skb = alloc_skb(len, GFP_KERNEL); |
6ac552fd | 1231 | if (skb == NULL) |
1da177e4 LT |
1232 | goto out; |
1233 | ||
1234 | NETLINK_CB(skb).pid = nlk->pid; | |
d629b836 | 1235 | NETLINK_CB(skb).dst_group = dst_group; |
c94c257c | 1236 | NETLINK_CB(skb).loginuid = audit_get_loginuid(current->audit_context); |
e7c34970 | 1237 | selinux_get_task_sid(current, &(NETLINK_CB(skb).sid)); |
1da177e4 LT |
1238 | memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); |
1239 | ||
1240 | /* What can I do? Netlink is asynchronous, so that | |
1241 | we will have to save current capabilities to | |
1242 | check them, when this message will be delivered | |
1243 | to corresponding kernel module. --ANK (980802) | |
1244 | */ | |
1245 | ||
1246 | err = -EFAULT; | |
6ac552fd | 1247 | if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) { |
1da177e4 LT |
1248 | kfree_skb(skb); |
1249 | goto out; | |
1250 | } | |
1251 | ||
1252 | err = security_netlink_send(sk, skb); | |
1253 | if (err) { | |
1254 | kfree_skb(skb); | |
1255 | goto out; | |
1256 | } | |
1257 | ||
d629b836 | 1258 | if (dst_group) { |
1da177e4 | 1259 | atomic_inc(&skb->users); |
d629b836 | 1260 | netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL); |
1da177e4 LT |
1261 | } |
1262 | err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT); | |
1263 | ||
1264 | out: | |
1265 | return err; | |
1266 | } | |
1267 | ||
1268 | static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, | |
1269 | struct msghdr *msg, size_t len, | |
1270 | int flags) | |
1271 | { | |
1272 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1273 | struct scm_cookie scm; | |
1274 | struct sock *sk = sock->sk; | |
1275 | struct netlink_sock *nlk = nlk_sk(sk); | |
1276 | int noblock = flags&MSG_DONTWAIT; | |
1277 | size_t copied; | |
1278 | struct sk_buff *skb; | |
1279 | int err; | |
1280 | ||
1281 | if (flags&MSG_OOB) | |
1282 | return -EOPNOTSUPP; | |
1283 | ||
1284 | copied = 0; | |
1285 | ||
6ac552fd PM |
1286 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
1287 | if (skb == NULL) | |
1da177e4 LT |
1288 | goto out; |
1289 | ||
1290 | msg->msg_namelen = 0; | |
1291 | ||
1292 | copied = skb->len; | |
1293 | if (len < copied) { | |
1294 | msg->msg_flags |= MSG_TRUNC; | |
1295 | copied = len; | |
1296 | } | |
1297 | ||
badff6d0 | 1298 | skb_reset_transport_header(skb); |
1da177e4 LT |
1299 | err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); |
1300 | ||
1301 | if (msg->msg_name) { | |
6ac552fd | 1302 | struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name; |
1da177e4 LT |
1303 | addr->nl_family = AF_NETLINK; |
1304 | addr->nl_pad = 0; | |
1305 | addr->nl_pid = NETLINK_CB(skb).pid; | |
d629b836 | 1306 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
1307 | msg->msg_namelen = sizeof(*addr); |
1308 | } | |
1309 | ||
cc9a06cd PM |
1310 | if (nlk->flags & NETLINK_RECV_PKTINFO) |
1311 | netlink_cmsg_recv_pktinfo(msg, skb); | |
1312 | ||
1da177e4 LT |
1313 | if (NULL == siocb->scm) { |
1314 | memset(&scm, 0, sizeof(scm)); | |
1315 | siocb->scm = &scm; | |
1316 | } | |
1317 | siocb->scm->creds = *NETLINK_CREDS(skb); | |
188ccb55 PM |
1318 | if (flags & MSG_TRUNC) |
1319 | copied = skb->len; | |
1da177e4 LT |
1320 | skb_free_datagram(sk, skb); |
1321 | ||
1322 | if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) | |
1323 | netlink_dump(sk); | |
1324 | ||
1325 | scm_recv(sock, msg, siocb->scm, flags); | |
1da177e4 LT |
1326 | out: |
1327 | netlink_rcv_wake(sk); | |
1328 | return err ? : copied; | |
1329 | } | |
1330 | ||
1331 | static void netlink_data_ready(struct sock *sk, int len) | |
1332 | { | |
cd40b7d3 | 1333 | BUG(); |
1da177e4 LT |
1334 | } |
1335 | ||
1336 | /* | |
746fac4d | 1337 | * We export these functions to other modules. They provide a |
1da177e4 LT |
1338 | * complete set of kernel non-blocking support for message |
1339 | * queueing. | |
1340 | */ | |
1341 | ||
1342 | struct sock * | |
b4b51029 | 1343 | netlink_kernel_create(struct net *net, int unit, unsigned int groups, |
cd40b7d3 | 1344 | void (*input)(struct sk_buff *skb), |
af65bdfc | 1345 | struct mutex *cb_mutex, struct module *module) |
1da177e4 LT |
1346 | { |
1347 | struct socket *sock; | |
1348 | struct sock *sk; | |
77247bbb | 1349 | struct netlink_sock *nlk; |
4277a083 | 1350 | unsigned long *listeners = NULL; |
1da177e4 | 1351 | |
fab2caf6 | 1352 | BUG_ON(!nl_table); |
1da177e4 | 1353 | |
6ac552fd | 1354 | if (unit < 0 || unit >= MAX_LINKS) |
1da177e4 LT |
1355 | return NULL; |
1356 | ||
1357 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
1358 | return NULL; | |
1359 | ||
b4b51029 | 1360 | if (__netlink_create(net, sock, cb_mutex, unit) < 0) |
77247bbb | 1361 | goto out_sock_release; |
4fdb3bb7 | 1362 | |
4277a083 PM |
1363 | if (groups < 32) |
1364 | groups = 32; | |
1365 | ||
1366 | listeners = kzalloc(NLGRPSZ(groups), GFP_KERNEL); | |
1367 | if (!listeners) | |
1368 | goto out_sock_release; | |
1369 | ||
1da177e4 LT |
1370 | sk = sock->sk; |
1371 | sk->sk_data_ready = netlink_data_ready; | |
1372 | if (input) | |
cd40b7d3 | 1373 | nlk_sk(sk)->netlink_rcv = input; |
1da177e4 | 1374 | |
b4b51029 | 1375 | if (netlink_insert(sk, net, 0)) |
77247bbb | 1376 | goto out_sock_release; |
4fdb3bb7 | 1377 | |
77247bbb PM |
1378 | nlk = nlk_sk(sk); |
1379 | nlk->flags |= NETLINK_KERNEL_SOCKET; | |
4fdb3bb7 | 1380 | |
4fdb3bb7 | 1381 | netlink_table_grab(); |
b4b51029 EB |
1382 | if (!nl_table[unit].registered) { |
1383 | nl_table[unit].groups = groups; | |
1384 | nl_table[unit].listeners = listeners; | |
1385 | nl_table[unit].cb_mutex = cb_mutex; | |
1386 | nl_table[unit].module = module; | |
1387 | nl_table[unit].registered = 1; | |
f937f1f4 JJ |
1388 | } else { |
1389 | kfree(listeners); | |
b4b51029 | 1390 | } |
4fdb3bb7 | 1391 | netlink_table_ungrab(); |
77247bbb PM |
1392 | |
1393 | return sk; | |
1394 | ||
4fdb3bb7 | 1395 | out_sock_release: |
4277a083 | 1396 | kfree(listeners); |
4fdb3bb7 | 1397 | sock_release(sock); |
77247bbb | 1398 | return NULL; |
1da177e4 | 1399 | } |
6ac552fd | 1400 | EXPORT_SYMBOL(netlink_kernel_create); |
1da177e4 | 1401 | |
b4ff4f04 JB |
1402 | /** |
1403 | * netlink_change_ngroups - change number of multicast groups | |
1404 | * | |
1405 | * This changes the number of multicast groups that are available | |
1406 | * on a certain netlink family. Note that it is not possible to | |
84659eb5 JB |
1407 | * change the number of groups to below 32. Also note that it does |
1408 | * not implicitly call netlink_clear_multicast_users() when the | |
1409 | * number of groups is reduced. | |
b4ff4f04 JB |
1410 | * |
1411 | * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). | |
1412 | * @groups: The new number of groups. | |
1413 | */ | |
1414 | int netlink_change_ngroups(struct sock *sk, unsigned int groups) | |
1415 | { | |
1416 | unsigned long *listeners, *old = NULL; | |
1417 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
1418 | int err = 0; | |
1419 | ||
1420 | if (groups < 32) | |
1421 | groups = 32; | |
1422 | ||
1423 | netlink_table_grab(); | |
1424 | if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { | |
1425 | listeners = kzalloc(NLGRPSZ(groups), GFP_ATOMIC); | |
1426 | if (!listeners) { | |
1427 | err = -ENOMEM; | |
1428 | goto out_ungrab; | |
1429 | } | |
1430 | old = tbl->listeners; | |
1431 | memcpy(listeners, old, NLGRPSZ(tbl->groups)); | |
1432 | rcu_assign_pointer(tbl->listeners, listeners); | |
1433 | } | |
1434 | tbl->groups = groups; | |
1435 | ||
1436 | out_ungrab: | |
1437 | netlink_table_ungrab(); | |
1438 | synchronize_rcu(); | |
1439 | kfree(old); | |
1440 | return err; | |
1441 | } | |
1442 | EXPORT_SYMBOL(netlink_change_ngroups); | |
1443 | ||
84659eb5 JB |
1444 | /** |
1445 | * netlink_clear_multicast_users - kick off multicast listeners | |
1446 | * | |
1447 | * This function removes all listeners from the given group. | |
1448 | * @ksk: The kernel netlink socket, as returned by | |
1449 | * netlink_kernel_create(). | |
1450 | * @group: The multicast group to clear. | |
1451 | */ | |
1452 | void netlink_clear_multicast_users(struct sock *ksk, unsigned int group) | |
1453 | { | |
1454 | struct sock *sk; | |
1455 | struct hlist_node *node; | |
1456 | struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; | |
1457 | ||
1458 | netlink_table_grab(); | |
1459 | ||
1460 | sk_for_each_bound(sk, node, &tbl->mc_list) | |
1461 | netlink_update_socket_mc(nlk_sk(sk), group, 0); | |
1462 | ||
1463 | netlink_table_ungrab(); | |
1464 | } | |
1465 | EXPORT_SYMBOL(netlink_clear_multicast_users); | |
1466 | ||
1da177e4 | 1467 | void netlink_set_nonroot(int protocol, unsigned int flags) |
746fac4d YH |
1468 | { |
1469 | if ((unsigned int)protocol < MAX_LINKS) | |
1da177e4 | 1470 | nl_table[protocol].nl_nonroot = flags; |
746fac4d | 1471 | } |
6ac552fd | 1472 | EXPORT_SYMBOL(netlink_set_nonroot); |
1da177e4 LT |
1473 | |
1474 | static void netlink_destroy_callback(struct netlink_callback *cb) | |
1475 | { | |
1476 | if (cb->skb) | |
1477 | kfree_skb(cb->skb); | |
1478 | kfree(cb); | |
1479 | } | |
1480 | ||
1481 | /* | |
1482 | * It looks a bit ugly. | |
1483 | * It would be better to create kernel thread. | |
1484 | */ | |
1485 | ||
1486 | static int netlink_dump(struct sock *sk) | |
1487 | { | |
1488 | struct netlink_sock *nlk = nlk_sk(sk); | |
1489 | struct netlink_callback *cb; | |
1490 | struct sk_buff *skb; | |
1491 | struct nlmsghdr *nlh; | |
bf8b79e4 | 1492 | int len, err = -ENOBUFS; |
746fac4d | 1493 | |
1da177e4 LT |
1494 | skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL); |
1495 | if (!skb) | |
bf8b79e4 | 1496 | goto errout; |
1da177e4 | 1497 | |
af65bdfc | 1498 | mutex_lock(nlk->cb_mutex); |
1da177e4 LT |
1499 | |
1500 | cb = nlk->cb; | |
1501 | if (cb == NULL) { | |
bf8b79e4 TG |
1502 | err = -EINVAL; |
1503 | goto errout_skb; | |
1da177e4 LT |
1504 | } |
1505 | ||
1506 | len = cb->dump(skb, cb); | |
1507 | ||
1508 | if (len > 0) { | |
af65bdfc | 1509 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1510 | skb_queue_tail(&sk->sk_receive_queue, skb); |
1511 | sk->sk_data_ready(sk, len); | |
1512 | return 0; | |
1513 | } | |
1514 | ||
bf8b79e4 TG |
1515 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); |
1516 | if (!nlh) | |
1517 | goto errout_skb; | |
1518 | ||
1519 | memcpy(nlmsg_data(nlh), &len, sizeof(len)); | |
1520 | ||
1da177e4 LT |
1521 | skb_queue_tail(&sk->sk_receive_queue, skb); |
1522 | sk->sk_data_ready(sk, skb->len); | |
1523 | ||
a8f74b22 TG |
1524 | if (cb->done) |
1525 | cb->done(cb); | |
1da177e4 | 1526 | nlk->cb = NULL; |
af65bdfc | 1527 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1528 | |
1529 | netlink_destroy_callback(cb); | |
1da177e4 | 1530 | return 0; |
1797754e | 1531 | |
bf8b79e4 | 1532 | errout_skb: |
af65bdfc | 1533 | mutex_unlock(nlk->cb_mutex); |
bf8b79e4 TG |
1534 | kfree_skb(skb); |
1535 | errout: | |
1536 | return err; | |
1da177e4 LT |
1537 | } |
1538 | ||
1539 | int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, | |
1540 | struct nlmsghdr *nlh, | |
6ac552fd PM |
1541 | int (*dump)(struct sk_buff *skb, |
1542 | struct netlink_callback *), | |
1543 | int (*done)(struct netlink_callback *)) | |
1da177e4 LT |
1544 | { |
1545 | struct netlink_callback *cb; | |
1546 | struct sock *sk; | |
1547 | struct netlink_sock *nlk; | |
1548 | ||
0da974f4 | 1549 | cb = kzalloc(sizeof(*cb), GFP_KERNEL); |
1da177e4 LT |
1550 | if (cb == NULL) |
1551 | return -ENOBUFS; | |
1552 | ||
1da177e4 LT |
1553 | cb->dump = dump; |
1554 | cb->done = done; | |
1555 | cb->nlh = nlh; | |
1556 | atomic_inc(&skb->users); | |
1557 | cb->skb = skb; | |
1558 | ||
b4b51029 | 1559 | sk = netlink_lookup(ssk->sk_net, ssk->sk_protocol, NETLINK_CB(skb).pid); |
1da177e4 LT |
1560 | if (sk == NULL) { |
1561 | netlink_destroy_callback(cb); | |
1562 | return -ECONNREFUSED; | |
1563 | } | |
1564 | nlk = nlk_sk(sk); | |
3f660d66 | 1565 | /* A dump is in progress... */ |
af65bdfc | 1566 | mutex_lock(nlk->cb_mutex); |
3f660d66 | 1567 | if (nlk->cb) { |
af65bdfc | 1568 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1569 | netlink_destroy_callback(cb); |
1570 | sock_put(sk); | |
1571 | return -EBUSY; | |
1572 | } | |
1573 | nlk->cb = cb; | |
af65bdfc | 1574 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1575 | |
1576 | netlink_dump(sk); | |
1577 | sock_put(sk); | |
5c58298c DL |
1578 | |
1579 | /* We successfully started a dump, by returning -EINTR we | |
1580 | * signal not to send ACK even if it was requested. | |
1581 | */ | |
1582 | return -EINTR; | |
1da177e4 | 1583 | } |
6ac552fd | 1584 | EXPORT_SYMBOL(netlink_dump_start); |
1da177e4 LT |
1585 | |
1586 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) | |
1587 | { | |
1588 | struct sk_buff *skb; | |
1589 | struct nlmsghdr *rep; | |
1590 | struct nlmsgerr *errmsg; | |
339bf98f | 1591 | size_t payload = sizeof(*errmsg); |
1da177e4 | 1592 | |
339bf98f TG |
1593 | /* error messages get the original request appened */ |
1594 | if (err) | |
1595 | payload += nlmsg_len(nlh); | |
1da177e4 | 1596 | |
339bf98f | 1597 | skb = nlmsg_new(payload, GFP_KERNEL); |
1da177e4 LT |
1598 | if (!skb) { |
1599 | struct sock *sk; | |
1600 | ||
b4b51029 EB |
1601 | sk = netlink_lookup(in_skb->sk->sk_net, |
1602 | in_skb->sk->sk_protocol, | |
1da177e4 LT |
1603 | NETLINK_CB(in_skb).pid); |
1604 | if (sk) { | |
1605 | sk->sk_err = ENOBUFS; | |
1606 | sk->sk_error_report(sk); | |
1607 | sock_put(sk); | |
1608 | } | |
1609 | return; | |
1610 | } | |
1611 | ||
1612 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, | |
1797754e | 1613 | NLMSG_ERROR, sizeof(struct nlmsgerr), 0); |
bf8b79e4 | 1614 | errmsg = nlmsg_data(rep); |
1da177e4 | 1615 | errmsg->error = err; |
bf8b79e4 | 1616 | memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh)); |
1da177e4 LT |
1617 | netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT); |
1618 | } | |
6ac552fd | 1619 | EXPORT_SYMBOL(netlink_ack); |
1da177e4 | 1620 | |
cd40b7d3 | 1621 | int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
1d00a4eb | 1622 | struct nlmsghdr *)) |
82ace47a | 1623 | { |
82ace47a TG |
1624 | struct nlmsghdr *nlh; |
1625 | int err; | |
1626 | ||
1627 | while (skb->len >= nlmsg_total_size(0)) { | |
cd40b7d3 DL |
1628 | int msglen; |
1629 | ||
b529ccf2 | 1630 | nlh = nlmsg_hdr(skb); |
d35b6856 | 1631 | err = 0; |
82ace47a | 1632 | |
ad8e4b75 | 1633 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
1634 | return 0; |
1635 | ||
d35b6856 TG |
1636 | /* Only requests are handled by the kernel */ |
1637 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | |
5c58298c | 1638 | goto ack; |
45e7ae7f TG |
1639 | |
1640 | /* Skip control messages */ | |
1641 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | |
5c58298c | 1642 | goto ack; |
d35b6856 | 1643 | |
1d00a4eb | 1644 | err = cb(skb, nlh); |
5c58298c DL |
1645 | if (err == -EINTR) |
1646 | goto skip; | |
1647 | ||
1648 | ack: | |
d35b6856 | 1649 | if (nlh->nlmsg_flags & NLM_F_ACK || err) |
82ace47a | 1650 | netlink_ack(skb, nlh, err); |
82ace47a | 1651 | |
5c58298c | 1652 | skip: |
6ac552fd | 1653 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
cd40b7d3 DL |
1654 | if (msglen > skb->len) |
1655 | msglen = skb->len; | |
1656 | skb_pull(skb, msglen); | |
82ace47a TG |
1657 | } |
1658 | ||
1659 | return 0; | |
1660 | } | |
6ac552fd | 1661 | EXPORT_SYMBOL(netlink_rcv_skb); |
82ace47a | 1662 | |
d387f6ad TG |
1663 | /** |
1664 | * nlmsg_notify - send a notification netlink message | |
1665 | * @sk: netlink socket to use | |
1666 | * @skb: notification message | |
1667 | * @pid: destination netlink pid for reports or 0 | |
1668 | * @group: destination multicast group or 0 | |
1669 | * @report: 1 to report back, 0 to disable | |
1670 | * @flags: allocation flags | |
1671 | */ | |
1672 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid, | |
1673 | unsigned int group, int report, gfp_t flags) | |
1674 | { | |
1675 | int err = 0; | |
1676 | ||
1677 | if (group) { | |
1678 | int exclude_pid = 0; | |
1679 | ||
1680 | if (report) { | |
1681 | atomic_inc(&skb->users); | |
1682 | exclude_pid = pid; | |
1683 | } | |
1684 | ||
1685 | /* errors reported via destination sk->sk_err */ | |
1686 | nlmsg_multicast(sk, skb, exclude_pid, group, flags); | |
1687 | } | |
1688 | ||
1689 | if (report) | |
1690 | err = nlmsg_unicast(sk, skb, pid); | |
1691 | ||
1692 | return err; | |
1693 | } | |
6ac552fd | 1694 | EXPORT_SYMBOL(nlmsg_notify); |
d387f6ad | 1695 | |
1da177e4 LT |
1696 | #ifdef CONFIG_PROC_FS |
1697 | struct nl_seq_iter { | |
e372c414 | 1698 | struct seq_net_private p; |
1da177e4 LT |
1699 | int link; |
1700 | int hash_idx; | |
1701 | }; | |
1702 | ||
1703 | static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) | |
1704 | { | |
1705 | struct nl_seq_iter *iter = seq->private; | |
1706 | int i, j; | |
1707 | struct sock *s; | |
1708 | struct hlist_node *node; | |
1709 | loff_t off = 0; | |
1710 | ||
6ac552fd | 1711 | for (i = 0; i < MAX_LINKS; i++) { |
1da177e4 LT |
1712 | struct nl_pid_hash *hash = &nl_table[i].hash; |
1713 | ||
1714 | for (j = 0; j <= hash->mask; j++) { | |
1715 | sk_for_each(s, node, &hash->table[j]) { | |
e372c414 | 1716 | if (iter->p.net != s->sk_net) |
b4b51029 | 1717 | continue; |
1da177e4 LT |
1718 | if (off == pos) { |
1719 | iter->link = i; | |
1720 | iter->hash_idx = j; | |
1721 | return s; | |
1722 | } | |
1723 | ++off; | |
1724 | } | |
1725 | } | |
1726 | } | |
1727 | return NULL; | |
1728 | } | |
1729 | ||
1730 | static void *netlink_seq_start(struct seq_file *seq, loff_t *pos) | |
1731 | { | |
1732 | read_lock(&nl_table_lock); | |
1733 | return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
1734 | } | |
1735 | ||
1736 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
1737 | { | |
1738 | struct sock *s; | |
1739 | struct nl_seq_iter *iter; | |
1740 | int i, j; | |
1741 | ||
1742 | ++*pos; | |
1743 | ||
1744 | if (v == SEQ_START_TOKEN) | |
1745 | return netlink_seq_socket_idx(seq, 0); | |
746fac4d | 1746 | |
b4b51029 EB |
1747 | iter = seq->private; |
1748 | s = v; | |
1749 | do { | |
1750 | s = sk_next(s); | |
e372c414 | 1751 | } while (s && (iter->p.net != s->sk_net)); |
1da177e4 LT |
1752 | if (s) |
1753 | return s; | |
1754 | ||
1da177e4 LT |
1755 | i = iter->link; |
1756 | j = iter->hash_idx + 1; | |
1757 | ||
1758 | do { | |
1759 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1760 | ||
1761 | for (; j <= hash->mask; j++) { | |
1762 | s = sk_head(&hash->table[j]); | |
e372c414 | 1763 | while (s && (iter->p.net != s->sk_net)) |
b4b51029 | 1764 | s = sk_next(s); |
1da177e4 LT |
1765 | if (s) { |
1766 | iter->link = i; | |
1767 | iter->hash_idx = j; | |
1768 | return s; | |
1769 | } | |
1770 | } | |
1771 | ||
1772 | j = 0; | |
1773 | } while (++i < MAX_LINKS); | |
1774 | ||
1775 | return NULL; | |
1776 | } | |
1777 | ||
1778 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
1779 | { | |
1780 | read_unlock(&nl_table_lock); | |
1781 | } | |
1782 | ||
1783 | ||
1784 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
1785 | { | |
1786 | if (v == SEQ_START_TOKEN) | |
1787 | seq_puts(seq, | |
1788 | "sk Eth Pid Groups " | |
1789 | "Rmem Wmem Dump Locks\n"); | |
1790 | else { | |
1791 | struct sock *s = v; | |
1792 | struct netlink_sock *nlk = nlk_sk(s); | |
1793 | ||
1794 | seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %d\n", | |
1795 | s, | |
1796 | s->sk_protocol, | |
1797 | nlk->pid, | |
513c2500 | 1798 | nlk->groups ? (u32)nlk->groups[0] : 0, |
1da177e4 LT |
1799 | atomic_read(&s->sk_rmem_alloc), |
1800 | atomic_read(&s->sk_wmem_alloc), | |
1801 | nlk->cb, | |
1802 | atomic_read(&s->sk_refcnt) | |
1803 | ); | |
1804 | ||
1805 | } | |
1806 | return 0; | |
1807 | } | |
1808 | ||
56b3d975 | 1809 | static const struct seq_operations netlink_seq_ops = { |
1da177e4 LT |
1810 | .start = netlink_seq_start, |
1811 | .next = netlink_seq_next, | |
1812 | .stop = netlink_seq_stop, | |
1813 | .show = netlink_seq_show, | |
1814 | }; | |
1815 | ||
1816 | ||
1817 | static int netlink_seq_open(struct inode *inode, struct file *file) | |
1818 | { | |
e372c414 DL |
1819 | return seq_open_net(inode, file, &netlink_seq_ops, |
1820 | sizeof(struct nl_seq_iter)); | |
b4b51029 EB |
1821 | } |
1822 | ||
da7071d7 | 1823 | static const struct file_operations netlink_seq_fops = { |
1da177e4 LT |
1824 | .owner = THIS_MODULE, |
1825 | .open = netlink_seq_open, | |
1826 | .read = seq_read, | |
1827 | .llseek = seq_lseek, | |
e372c414 | 1828 | .release = seq_release_net, |
1da177e4 LT |
1829 | }; |
1830 | ||
1831 | #endif | |
1832 | ||
1833 | int netlink_register_notifier(struct notifier_block *nb) | |
1834 | { | |
e041c683 | 1835 | return atomic_notifier_chain_register(&netlink_chain, nb); |
1da177e4 | 1836 | } |
6ac552fd | 1837 | EXPORT_SYMBOL(netlink_register_notifier); |
1da177e4 LT |
1838 | |
1839 | int netlink_unregister_notifier(struct notifier_block *nb) | |
1840 | { | |
e041c683 | 1841 | return atomic_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 | 1842 | } |
6ac552fd | 1843 | EXPORT_SYMBOL(netlink_unregister_notifier); |
746fac4d | 1844 | |
90ddc4f0 | 1845 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
1846 | .family = PF_NETLINK, |
1847 | .owner = THIS_MODULE, | |
1848 | .release = netlink_release, | |
1849 | .bind = netlink_bind, | |
1850 | .connect = netlink_connect, | |
1851 | .socketpair = sock_no_socketpair, | |
1852 | .accept = sock_no_accept, | |
1853 | .getname = netlink_getname, | |
1854 | .poll = datagram_poll, | |
1855 | .ioctl = sock_no_ioctl, | |
1856 | .listen = sock_no_listen, | |
1857 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
1858 | .setsockopt = netlink_setsockopt, |
1859 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
1860 | .sendmsg = netlink_sendmsg, |
1861 | .recvmsg = netlink_recvmsg, | |
1862 | .mmap = sock_no_mmap, | |
1863 | .sendpage = sock_no_sendpage, | |
1864 | }; | |
1865 | ||
1866 | static struct net_proto_family netlink_family_ops = { | |
1867 | .family = PF_NETLINK, | |
1868 | .create = netlink_create, | |
1869 | .owner = THIS_MODULE, /* for consistency 8) */ | |
1870 | }; | |
1871 | ||
4665079c | 1872 | static int __net_init netlink_net_init(struct net *net) |
b4b51029 EB |
1873 | { |
1874 | #ifdef CONFIG_PROC_FS | |
1875 | if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops)) | |
1876 | return -ENOMEM; | |
1877 | #endif | |
1878 | return 0; | |
1879 | } | |
1880 | ||
4665079c | 1881 | static void __net_exit netlink_net_exit(struct net *net) |
b4b51029 EB |
1882 | { |
1883 | #ifdef CONFIG_PROC_FS | |
1884 | proc_net_remove(net, "netlink"); | |
1885 | #endif | |
1886 | } | |
1887 | ||
022cbae6 | 1888 | static struct pernet_operations __net_initdata netlink_net_ops = { |
b4b51029 EB |
1889 | .init = netlink_net_init, |
1890 | .exit = netlink_net_exit, | |
1891 | }; | |
1892 | ||
1da177e4 LT |
1893 | static int __init netlink_proto_init(void) |
1894 | { | |
1895 | struct sk_buff *dummy_skb; | |
1896 | int i; | |
26ff5ddc | 1897 | unsigned long limit; |
1da177e4 LT |
1898 | unsigned int order; |
1899 | int err = proto_register(&netlink_proto, 0); | |
1900 | ||
1901 | if (err != 0) | |
1902 | goto out; | |
1903 | ||
ef047f5e | 1904 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb)); |
1da177e4 | 1905 | |
0da974f4 | 1906 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
1907 | if (!nl_table) |
1908 | goto panic; | |
1da177e4 | 1909 | |
1da177e4 | 1910 | if (num_physpages >= (128 * 1024)) |
26ff5ddc | 1911 | limit = num_physpages >> (21 - PAGE_SHIFT); |
1da177e4 | 1912 | else |
26ff5ddc | 1913 | limit = num_physpages >> (23 - PAGE_SHIFT); |
1da177e4 | 1914 | |
26ff5ddc DC |
1915 | order = get_bitmask_order(limit) - 1 + PAGE_SHIFT; |
1916 | limit = (1UL << order) / sizeof(struct hlist_head); | |
1917 | order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1; | |
1da177e4 LT |
1918 | |
1919 | for (i = 0; i < MAX_LINKS; i++) { | |
1920 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1921 | ||
ea72912c | 1922 | hash->table = nl_pid_hash_zalloc(1 * sizeof(*hash->table)); |
1da177e4 LT |
1923 | if (!hash->table) { |
1924 | while (i-- > 0) | |
1925 | nl_pid_hash_free(nl_table[i].hash.table, | |
1926 | 1 * sizeof(*hash->table)); | |
1927 | kfree(nl_table); | |
fab2caf6 | 1928 | goto panic; |
1da177e4 | 1929 | } |
1da177e4 LT |
1930 | hash->max_shift = order; |
1931 | hash->shift = 0; | |
1932 | hash->mask = 0; | |
1933 | hash->rehash_time = jiffies; | |
1934 | } | |
1935 | ||
1936 | sock_register(&netlink_family_ops); | |
b4b51029 | 1937 | register_pernet_subsys(&netlink_net_ops); |
746fac4d | 1938 | /* The netlink device handler may be needed early. */ |
1da177e4 LT |
1939 | rtnetlink_init(); |
1940 | out: | |
1941 | return err; | |
fab2caf6 AM |
1942 | panic: |
1943 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
1944 | } |
1945 | ||
1da177e4 | 1946 | core_initcall(netlink_proto_init); |