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) | |
9a429c49 | 174 | __acquires(nl_table_lock) |
1da177e4 | 175 | { |
6abd219c | 176 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
177 | |
178 | if (atomic_read(&nl_table_users)) { | |
179 | DECLARE_WAITQUEUE(wait, current); | |
180 | ||
181 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
6ac552fd | 182 | for (;;) { |
1da177e4 LT |
183 | set_current_state(TASK_UNINTERRUPTIBLE); |
184 | if (atomic_read(&nl_table_users) == 0) | |
185 | break; | |
6abd219c | 186 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 187 | schedule(); |
6abd219c | 188 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
189 | } |
190 | ||
191 | __set_current_state(TASK_RUNNING); | |
192 | remove_wait_queue(&nl_table_wait, &wait); | |
193 | } | |
194 | } | |
195 | ||
6ac552fd | 196 | static inline void netlink_table_ungrab(void) |
9a429c49 | 197 | __releases(nl_table_lock) |
1da177e4 | 198 | { |
6abd219c | 199 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
200 | wake_up(&nl_table_wait); |
201 | } | |
202 | ||
6ac552fd | 203 | static inline void |
1da177e4 LT |
204 | netlink_lock_table(void) |
205 | { | |
206 | /* read_lock() synchronizes us to netlink_table_grab */ | |
207 | ||
208 | read_lock(&nl_table_lock); | |
209 | atomic_inc(&nl_table_users); | |
210 | read_unlock(&nl_table_lock); | |
211 | } | |
212 | ||
6ac552fd | 213 | static inline void |
1da177e4 LT |
214 | netlink_unlock_table(void) |
215 | { | |
216 | if (atomic_dec_and_test(&nl_table_users)) | |
217 | wake_up(&nl_table_wait); | |
218 | } | |
219 | ||
6ac552fd PM |
220 | static inline struct sock *netlink_lookup(struct net *net, int protocol, |
221 | u32 pid) | |
1da177e4 LT |
222 | { |
223 | struct nl_pid_hash *hash = &nl_table[protocol].hash; | |
224 | struct hlist_head *head; | |
225 | struct sock *sk; | |
226 | struct hlist_node *node; | |
227 | ||
228 | read_lock(&nl_table_lock); | |
229 | head = nl_pid_hashfn(hash, pid); | |
230 | sk_for_each(sk, node, head) { | |
b4b51029 | 231 | if ((sk->sk_net == net) && (nlk_sk(sk)->pid == pid)) { |
1da177e4 LT |
232 | sock_hold(sk); |
233 | goto found; | |
234 | } | |
235 | } | |
236 | sk = NULL; | |
237 | found: | |
238 | read_unlock(&nl_table_lock); | |
239 | return sk; | |
240 | } | |
241 | ||
ea72912c | 242 | static inline struct hlist_head *nl_pid_hash_zalloc(size_t size) |
1da177e4 LT |
243 | { |
244 | if (size <= PAGE_SIZE) | |
ea72912c | 245 | return kzalloc(size, GFP_ATOMIC); |
1da177e4 LT |
246 | else |
247 | return (struct hlist_head *) | |
ea72912c ED |
248 | __get_free_pages(GFP_ATOMIC | __GFP_ZERO, |
249 | get_order(size)); | |
1da177e4 LT |
250 | } |
251 | ||
252 | static inline void nl_pid_hash_free(struct hlist_head *table, size_t size) | |
253 | { | |
254 | if (size <= PAGE_SIZE) | |
255 | kfree(table); | |
256 | else | |
257 | free_pages((unsigned long)table, get_order(size)); | |
258 | } | |
259 | ||
260 | static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow) | |
261 | { | |
262 | unsigned int omask, mask, shift; | |
263 | size_t osize, size; | |
264 | struct hlist_head *otable, *table; | |
265 | int i; | |
266 | ||
267 | omask = mask = hash->mask; | |
268 | osize = size = (mask + 1) * sizeof(*table); | |
269 | shift = hash->shift; | |
270 | ||
271 | if (grow) { | |
272 | if (++shift > hash->max_shift) | |
273 | return 0; | |
274 | mask = mask * 2 + 1; | |
275 | size *= 2; | |
276 | } | |
277 | ||
ea72912c | 278 | table = nl_pid_hash_zalloc(size); |
1da177e4 LT |
279 | if (!table) |
280 | return 0; | |
281 | ||
1da177e4 LT |
282 | otable = hash->table; |
283 | hash->table = table; | |
284 | hash->mask = mask; | |
285 | hash->shift = shift; | |
286 | get_random_bytes(&hash->rnd, sizeof(hash->rnd)); | |
287 | ||
288 | for (i = 0; i <= omask; i++) { | |
289 | struct sock *sk; | |
290 | struct hlist_node *node, *tmp; | |
291 | ||
292 | sk_for_each_safe(sk, node, tmp, &otable[i]) | |
293 | __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid)); | |
294 | } | |
295 | ||
296 | nl_pid_hash_free(otable, osize); | |
297 | hash->rehash_time = jiffies + 10 * 60 * HZ; | |
298 | return 1; | |
299 | } | |
300 | ||
301 | static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len) | |
302 | { | |
303 | int avg = hash->entries >> hash->shift; | |
304 | ||
305 | if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1)) | |
306 | return 1; | |
307 | ||
308 | if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) { | |
309 | nl_pid_hash_rehash(hash, 0); | |
310 | return 1; | |
311 | } | |
312 | ||
313 | return 0; | |
314 | } | |
315 | ||
90ddc4f0 | 316 | static const struct proto_ops netlink_ops; |
1da177e4 | 317 | |
4277a083 PM |
318 | static void |
319 | netlink_update_listeners(struct sock *sk) | |
320 | { | |
321 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
322 | struct hlist_node *node; | |
323 | unsigned long mask; | |
324 | unsigned int i; | |
325 | ||
b4ff4f04 | 326 | for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
4277a083 | 327 | mask = 0; |
b4ff4f04 JB |
328 | sk_for_each_bound(sk, node, &tbl->mc_list) { |
329 | if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) | |
330 | mask |= nlk_sk(sk)->groups[i]; | |
331 | } | |
4277a083 PM |
332 | tbl->listeners[i] = mask; |
333 | } | |
334 | /* this function is only called with the netlink table "grabbed", which | |
335 | * makes sure updates are visible before bind or setsockopt return. */ | |
336 | } | |
337 | ||
b4b51029 | 338 | static int netlink_insert(struct sock *sk, struct net *net, u32 pid) |
1da177e4 LT |
339 | { |
340 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; | |
341 | struct hlist_head *head; | |
342 | int err = -EADDRINUSE; | |
343 | struct sock *osk; | |
344 | struct hlist_node *node; | |
345 | int len; | |
346 | ||
347 | netlink_table_grab(); | |
348 | head = nl_pid_hashfn(hash, pid); | |
349 | len = 0; | |
350 | sk_for_each(osk, node, head) { | |
b4b51029 | 351 | if ((osk->sk_net == net) && (nlk_sk(osk)->pid == pid)) |
1da177e4 LT |
352 | break; |
353 | len++; | |
354 | } | |
355 | if (node) | |
356 | goto err; | |
357 | ||
358 | err = -EBUSY; | |
359 | if (nlk_sk(sk)->pid) | |
360 | goto err; | |
361 | ||
362 | err = -ENOMEM; | |
363 | if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX)) | |
364 | goto err; | |
365 | ||
366 | if (len && nl_pid_hash_dilute(hash, len)) | |
367 | head = nl_pid_hashfn(hash, pid); | |
368 | hash->entries++; | |
369 | nlk_sk(sk)->pid = pid; | |
370 | sk_add_node(sk, head); | |
371 | err = 0; | |
372 | ||
373 | err: | |
374 | netlink_table_ungrab(); | |
375 | return err; | |
376 | } | |
377 | ||
378 | static void netlink_remove(struct sock *sk) | |
379 | { | |
380 | netlink_table_grab(); | |
d470e3b4 DM |
381 | if (sk_del_node_init(sk)) |
382 | nl_table[sk->sk_protocol].hash.entries--; | |
f7fa9b10 | 383 | if (nlk_sk(sk)->subscriptions) |
1da177e4 LT |
384 | __sk_del_bind_node(sk); |
385 | netlink_table_ungrab(); | |
386 | } | |
387 | ||
388 | static struct proto netlink_proto = { | |
389 | .name = "NETLINK", | |
390 | .owner = THIS_MODULE, | |
391 | .obj_size = sizeof(struct netlink_sock), | |
392 | }; | |
393 | ||
1b8d7ae4 EB |
394 | static int __netlink_create(struct net *net, struct socket *sock, |
395 | struct mutex *cb_mutex, int protocol) | |
1da177e4 LT |
396 | { |
397 | struct sock *sk; | |
398 | struct netlink_sock *nlk; | |
ab33a171 PM |
399 | |
400 | sock->ops = &netlink_ops; | |
401 | ||
6257ff21 | 402 | sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto); |
ab33a171 PM |
403 | if (!sk) |
404 | return -ENOMEM; | |
405 | ||
406 | sock_init_data(sock, sk); | |
407 | ||
408 | nlk = nlk_sk(sk); | |
ffa4d721 PM |
409 | if (cb_mutex) |
410 | nlk->cb_mutex = cb_mutex; | |
411 | else { | |
412 | nlk->cb_mutex = &nlk->cb_def_mutex; | |
413 | mutex_init(nlk->cb_mutex); | |
414 | } | |
ab33a171 PM |
415 | init_waitqueue_head(&nlk->wait); |
416 | ||
417 | sk->sk_destruct = netlink_sock_destruct; | |
418 | sk->sk_protocol = protocol; | |
419 | return 0; | |
420 | } | |
421 | ||
1b8d7ae4 | 422 | static int netlink_create(struct net *net, struct socket *sock, int protocol) |
ab33a171 PM |
423 | { |
424 | struct module *module = NULL; | |
af65bdfc | 425 | struct mutex *cb_mutex; |
f7fa9b10 | 426 | struct netlink_sock *nlk; |
ab33a171 | 427 | int err = 0; |
1da177e4 LT |
428 | |
429 | sock->state = SS_UNCONNECTED; | |
430 | ||
431 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
432 | return -ESOCKTNOSUPPORT; | |
433 | ||
6ac552fd | 434 | if (protocol < 0 || protocol >= MAX_LINKS) |
1da177e4 LT |
435 | return -EPROTONOSUPPORT; |
436 | ||
77247bbb | 437 | netlink_lock_table(); |
4fdb3bb7 | 438 | #ifdef CONFIG_KMOD |
ab33a171 | 439 | if (!nl_table[protocol].registered) { |
77247bbb | 440 | netlink_unlock_table(); |
4fdb3bb7 | 441 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 442 | netlink_lock_table(); |
4fdb3bb7 | 443 | } |
ab33a171 PM |
444 | #endif |
445 | if (nl_table[protocol].registered && | |
446 | try_module_get(nl_table[protocol].module)) | |
447 | module = nl_table[protocol].module; | |
af65bdfc | 448 | cb_mutex = nl_table[protocol].cb_mutex; |
77247bbb | 449 | netlink_unlock_table(); |
4fdb3bb7 | 450 | |
6ac552fd PM |
451 | err = __netlink_create(net, sock, cb_mutex, protocol); |
452 | if (err < 0) | |
f7fa9b10 PM |
453 | goto out_module; |
454 | ||
455 | nlk = nlk_sk(sock->sk); | |
f7fa9b10 | 456 | nlk->module = module; |
ab33a171 PM |
457 | out: |
458 | return err; | |
1da177e4 | 459 | |
ab33a171 PM |
460 | out_module: |
461 | module_put(module); | |
462 | goto out; | |
1da177e4 LT |
463 | } |
464 | ||
465 | static int netlink_release(struct socket *sock) | |
466 | { | |
467 | struct sock *sk = sock->sk; | |
468 | struct netlink_sock *nlk; | |
469 | ||
470 | if (!sk) | |
471 | return 0; | |
472 | ||
473 | netlink_remove(sk); | |
ac57b3a9 | 474 | sock_orphan(sk); |
1da177e4 LT |
475 | nlk = nlk_sk(sk); |
476 | ||
3f660d66 HX |
477 | /* |
478 | * OK. Socket is unlinked, any packets that arrive now | |
479 | * will be purged. | |
480 | */ | |
1da177e4 | 481 | |
1da177e4 LT |
482 | sock->sk = NULL; |
483 | wake_up_interruptible_all(&nlk->wait); | |
484 | ||
485 | skb_queue_purge(&sk->sk_write_queue); | |
486 | ||
f7fa9b10 | 487 | if (nlk->pid && !nlk->subscriptions) { |
1da177e4 | 488 | struct netlink_notify n = { |
b4b51029 | 489 | .net = sk->sk_net, |
1da177e4 LT |
490 | .protocol = sk->sk_protocol, |
491 | .pid = nlk->pid, | |
492 | }; | |
e041c683 AS |
493 | atomic_notifier_call_chain(&netlink_chain, |
494 | NETLINK_URELEASE, &n); | |
746fac4d | 495 | } |
4fdb3bb7 | 496 | |
5e7c001c | 497 | module_put(nlk->module); |
4fdb3bb7 | 498 | |
4277a083 | 499 | netlink_table_grab(); |
aed81560 | 500 | if (netlink_is_kernel(sk)) { |
4277a083 | 501 | kfree(nl_table[sk->sk_protocol].listeners); |
77247bbb | 502 | nl_table[sk->sk_protocol].module = NULL; |
ab33a171 | 503 | nl_table[sk->sk_protocol].registered = 0; |
4277a083 PM |
504 | } else if (nlk->subscriptions) |
505 | netlink_update_listeners(sk); | |
506 | netlink_table_ungrab(); | |
77247bbb | 507 | |
f7fa9b10 PM |
508 | kfree(nlk->groups); |
509 | nlk->groups = NULL; | |
510 | ||
1da177e4 LT |
511 | sock_put(sk); |
512 | return 0; | |
513 | } | |
514 | ||
515 | static int netlink_autobind(struct socket *sock) | |
516 | { | |
517 | struct sock *sk = sock->sk; | |
b4b51029 | 518 | struct net *net = sk->sk_net; |
1da177e4 LT |
519 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; |
520 | struct hlist_head *head; | |
521 | struct sock *osk; | |
522 | struct hlist_node *node; | |
c27bd492 | 523 | s32 pid = current->tgid; |
1da177e4 LT |
524 | int err; |
525 | static s32 rover = -4097; | |
526 | ||
527 | retry: | |
528 | cond_resched(); | |
529 | netlink_table_grab(); | |
530 | head = nl_pid_hashfn(hash, pid); | |
531 | sk_for_each(osk, node, head) { | |
b4b51029 EB |
532 | if ((osk->sk_net != net)) |
533 | continue; | |
1da177e4 LT |
534 | if (nlk_sk(osk)->pid == pid) { |
535 | /* Bind collision, search negative pid values. */ | |
536 | pid = rover--; | |
537 | if (rover > -4097) | |
538 | rover = -4097; | |
539 | netlink_table_ungrab(); | |
540 | goto retry; | |
541 | } | |
542 | } | |
543 | netlink_table_ungrab(); | |
544 | ||
b4b51029 | 545 | err = netlink_insert(sk, net, pid); |
1da177e4 LT |
546 | if (err == -EADDRINUSE) |
547 | goto retry; | |
d470e3b4 DM |
548 | |
549 | /* If 2 threads race to autobind, that is fine. */ | |
550 | if (err == -EBUSY) | |
551 | err = 0; | |
552 | ||
553 | return err; | |
1da177e4 LT |
554 | } |
555 | ||
746fac4d YH |
556 | static inline int netlink_capable(struct socket *sock, unsigned int flag) |
557 | { | |
1da177e4 LT |
558 | return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) || |
559 | capable(CAP_NET_ADMIN); | |
746fac4d | 560 | } |
1da177e4 | 561 | |
f7fa9b10 PM |
562 | static void |
563 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
564 | { | |
565 | struct netlink_sock *nlk = nlk_sk(sk); | |
566 | ||
567 | if (nlk->subscriptions && !subscriptions) | |
568 | __sk_del_bind_node(sk); | |
569 | else if (!nlk->subscriptions && subscriptions) | |
570 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
571 | nlk->subscriptions = subscriptions; | |
572 | } | |
573 | ||
b4ff4f04 | 574 | static int netlink_realloc_groups(struct sock *sk) |
513c2500 PM |
575 | { |
576 | struct netlink_sock *nlk = nlk_sk(sk); | |
577 | unsigned int groups; | |
b4ff4f04 | 578 | unsigned long *new_groups; |
513c2500 PM |
579 | int err = 0; |
580 | ||
b4ff4f04 JB |
581 | netlink_table_grab(); |
582 | ||
513c2500 | 583 | groups = nl_table[sk->sk_protocol].groups; |
b4ff4f04 | 584 | if (!nl_table[sk->sk_protocol].registered) { |
513c2500 | 585 | err = -ENOENT; |
b4ff4f04 JB |
586 | goto out_unlock; |
587 | } | |
513c2500 | 588 | |
b4ff4f04 JB |
589 | if (nlk->ngroups >= groups) |
590 | goto out_unlock; | |
513c2500 | 591 | |
b4ff4f04 JB |
592 | new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
593 | if (new_groups == NULL) { | |
594 | err = -ENOMEM; | |
595 | goto out_unlock; | |
596 | } | |
6ac552fd | 597 | memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, |
b4ff4f04 JB |
598 | NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); |
599 | ||
600 | nlk->groups = new_groups; | |
513c2500 | 601 | nlk->ngroups = groups; |
b4ff4f04 JB |
602 | out_unlock: |
603 | netlink_table_ungrab(); | |
604 | return err; | |
513c2500 PM |
605 | } |
606 | ||
6ac552fd PM |
607 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, |
608 | int addr_len) | |
1da177e4 LT |
609 | { |
610 | struct sock *sk = sock->sk; | |
b4b51029 | 611 | struct net *net = sk->sk_net; |
1da177e4 LT |
612 | struct netlink_sock *nlk = nlk_sk(sk); |
613 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
614 | int err; | |
746fac4d | 615 | |
1da177e4 LT |
616 | if (nladdr->nl_family != AF_NETLINK) |
617 | return -EINVAL; | |
618 | ||
619 | /* Only superuser is allowed to listen multicasts */ | |
513c2500 PM |
620 | if (nladdr->nl_groups) { |
621 | if (!netlink_capable(sock, NL_NONROOT_RECV)) | |
622 | return -EPERM; | |
b4ff4f04 JB |
623 | err = netlink_realloc_groups(sk); |
624 | if (err) | |
625 | return err; | |
513c2500 | 626 | } |
1da177e4 LT |
627 | |
628 | if (nlk->pid) { | |
629 | if (nladdr->nl_pid != nlk->pid) | |
630 | return -EINVAL; | |
631 | } else { | |
632 | err = nladdr->nl_pid ? | |
b4b51029 | 633 | netlink_insert(sk, net, nladdr->nl_pid) : |
1da177e4 LT |
634 | netlink_autobind(sock); |
635 | if (err) | |
636 | return err; | |
637 | } | |
638 | ||
513c2500 | 639 | if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
1da177e4 LT |
640 | return 0; |
641 | ||
642 | netlink_table_grab(); | |
f7fa9b10 | 643 | netlink_update_subscriptions(sk, nlk->subscriptions + |
746fac4d YH |
644 | hweight32(nladdr->nl_groups) - |
645 | hweight32(nlk->groups[0])); | |
646 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups; | |
4277a083 | 647 | netlink_update_listeners(sk); |
1da177e4 LT |
648 | netlink_table_ungrab(); |
649 | ||
650 | return 0; | |
651 | } | |
652 | ||
653 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
654 | int alen, int flags) | |
655 | { | |
656 | int err = 0; | |
657 | struct sock *sk = sock->sk; | |
658 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 659 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
1da177e4 LT |
660 | |
661 | if (addr->sa_family == AF_UNSPEC) { | |
662 | sk->sk_state = NETLINK_UNCONNECTED; | |
663 | nlk->dst_pid = 0; | |
d629b836 | 664 | nlk->dst_group = 0; |
1da177e4 LT |
665 | return 0; |
666 | } | |
667 | if (addr->sa_family != AF_NETLINK) | |
668 | return -EINVAL; | |
669 | ||
670 | /* Only superuser is allowed to send multicasts */ | |
671 | if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND)) | |
672 | return -EPERM; | |
673 | ||
674 | if (!nlk->pid) | |
675 | err = netlink_autobind(sock); | |
676 | ||
677 | if (err == 0) { | |
678 | sk->sk_state = NETLINK_CONNECTED; | |
679 | nlk->dst_pid = nladdr->nl_pid; | |
d629b836 | 680 | nlk->dst_group = ffs(nladdr->nl_groups); |
1da177e4 LT |
681 | } |
682 | ||
683 | return err; | |
684 | } | |
685 | ||
6ac552fd PM |
686 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, |
687 | int *addr_len, int peer) | |
1da177e4 LT |
688 | { |
689 | struct sock *sk = sock->sk; | |
690 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 691 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
746fac4d | 692 | |
1da177e4 LT |
693 | nladdr->nl_family = AF_NETLINK; |
694 | nladdr->nl_pad = 0; | |
695 | *addr_len = sizeof(*nladdr); | |
696 | ||
697 | if (peer) { | |
698 | nladdr->nl_pid = nlk->dst_pid; | |
d629b836 | 699 | nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
1da177e4 LT |
700 | } else { |
701 | nladdr->nl_pid = nlk->pid; | |
513c2500 | 702 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
1da177e4 LT |
703 | } |
704 | return 0; | |
705 | } | |
706 | ||
707 | static void netlink_overrun(struct sock *sk) | |
708 | { | |
709 | if (!test_and_set_bit(0, &nlk_sk(sk)->state)) { | |
710 | sk->sk_err = ENOBUFS; | |
711 | sk->sk_error_report(sk); | |
712 | } | |
713 | } | |
714 | ||
715 | static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid) | |
716 | { | |
1da177e4 LT |
717 | struct sock *sock; |
718 | struct netlink_sock *nlk; | |
719 | ||
cd40b7d3 | 720 | sock = netlink_lookup(ssk->sk_net, ssk->sk_protocol, pid); |
1da177e4 LT |
721 | if (!sock) |
722 | return ERR_PTR(-ECONNREFUSED); | |
723 | ||
724 | /* Don't bother queuing skb if kernel socket has no input function */ | |
725 | nlk = nlk_sk(sock); | |
cd40b7d3 DL |
726 | if (sock->sk_state == NETLINK_CONNECTED && |
727 | nlk->dst_pid != nlk_sk(ssk)->pid) { | |
1da177e4 LT |
728 | sock_put(sock); |
729 | return ERR_PTR(-ECONNREFUSED); | |
730 | } | |
731 | return sock; | |
732 | } | |
733 | ||
734 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
735 | { | |
6db5fc5d | 736 | struct inode *inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
737 | struct sock *sock; |
738 | ||
739 | if (!S_ISSOCK(inode->i_mode)) | |
740 | return ERR_PTR(-ENOTSOCK); | |
741 | ||
742 | sock = SOCKET_I(inode)->sk; | |
743 | if (sock->sk_family != AF_NETLINK) | |
744 | return ERR_PTR(-EINVAL); | |
745 | ||
746 | sock_hold(sock); | |
747 | return sock; | |
748 | } | |
749 | ||
750 | /* | |
751 | * Attach a skb to a netlink socket. | |
752 | * The caller must hold a reference to the destination socket. On error, the | |
753 | * reference is dropped. The skb is not send to the destination, just all | |
754 | * all error checks are performed and memory in the queue is reserved. | |
755 | * Return values: | |
756 | * < 0: error. skb freed, reference to sock dropped. | |
757 | * 0: continue | |
758 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
759 | */ | |
a70ea994 | 760 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock, |
c3d8d1e3 | 761 | long *timeo, struct sock *ssk) |
1da177e4 LT |
762 | { |
763 | struct netlink_sock *nlk; | |
764 | ||
765 | nlk = nlk_sk(sk); | |
766 | ||
767 | if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
768 | test_bit(0, &nlk->state)) { | |
769 | DECLARE_WAITQUEUE(wait, current); | |
c3d8d1e3 | 770 | if (!*timeo) { |
aed81560 | 771 | if (!ssk || netlink_is_kernel(ssk)) |
1da177e4 LT |
772 | netlink_overrun(sk); |
773 | sock_put(sk); | |
774 | kfree_skb(skb); | |
775 | return -EAGAIN; | |
776 | } | |
777 | ||
778 | __set_current_state(TASK_INTERRUPTIBLE); | |
779 | add_wait_queue(&nlk->wait, &wait); | |
780 | ||
781 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
782 | test_bit(0, &nlk->state)) && | |
783 | !sock_flag(sk, SOCK_DEAD)) | |
c3d8d1e3 | 784 | *timeo = schedule_timeout(*timeo); |
1da177e4 LT |
785 | |
786 | __set_current_state(TASK_RUNNING); | |
787 | remove_wait_queue(&nlk->wait, &wait); | |
788 | sock_put(sk); | |
789 | ||
790 | if (signal_pending(current)) { | |
791 | kfree_skb(skb); | |
c3d8d1e3 | 792 | return sock_intr_errno(*timeo); |
1da177e4 LT |
793 | } |
794 | return 1; | |
795 | } | |
796 | skb_set_owner_r(skb, sk); | |
797 | return 0; | |
798 | } | |
799 | ||
7ee015e0 | 800 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 801 | { |
1da177e4 LT |
802 | int len = skb->len; |
803 | ||
1da177e4 LT |
804 | skb_queue_tail(&sk->sk_receive_queue, skb); |
805 | sk->sk_data_ready(sk, len); | |
806 | sock_put(sk); | |
807 | return len; | |
808 | } | |
809 | ||
810 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
811 | { | |
812 | kfree_skb(skb); | |
813 | sock_put(sk); | |
814 | } | |
815 | ||
37da647d | 816 | static inline struct sk_buff *netlink_trim(struct sk_buff *skb, |
dd0fc66f | 817 | gfp_t allocation) |
1da177e4 LT |
818 | { |
819 | int delta; | |
820 | ||
821 | skb_orphan(skb); | |
822 | ||
4305b541 | 823 | delta = skb->end - skb->tail; |
1da177e4 LT |
824 | if (delta * 2 < skb->truesize) |
825 | return skb; | |
826 | ||
827 | if (skb_shared(skb)) { | |
828 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
829 | if (!nskb) | |
830 | return skb; | |
831 | kfree_skb(skb); | |
832 | skb = nskb; | |
833 | } | |
834 | ||
835 | if (!pskb_expand_head(skb, 0, -delta, allocation)) | |
836 | skb->truesize -= delta; | |
837 | ||
838 | return skb; | |
839 | } | |
840 | ||
cd40b7d3 DL |
841 | static inline void netlink_rcv_wake(struct sock *sk) |
842 | { | |
843 | struct netlink_sock *nlk = nlk_sk(sk); | |
844 | ||
845 | if (skb_queue_empty(&sk->sk_receive_queue)) | |
846 | clear_bit(0, &nlk->state); | |
847 | if (!test_bit(0, &nlk->state)) | |
848 | wake_up_interruptible(&nlk->wait); | |
849 | } | |
850 | ||
851 | static inline int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb) | |
852 | { | |
853 | int ret; | |
854 | struct netlink_sock *nlk = nlk_sk(sk); | |
855 | ||
856 | ret = -ECONNREFUSED; | |
857 | if (nlk->netlink_rcv != NULL) { | |
858 | ret = skb->len; | |
859 | skb_set_owner_r(skb, sk); | |
860 | nlk->netlink_rcv(skb); | |
861 | } | |
862 | kfree_skb(skb); | |
863 | sock_put(sk); | |
864 | return ret; | |
865 | } | |
866 | ||
867 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, | |
868 | u32 pid, int nonblock) | |
1da177e4 LT |
869 | { |
870 | struct sock *sk; | |
871 | int err; | |
872 | long timeo; | |
873 | ||
874 | skb = netlink_trim(skb, gfp_any()); | |
875 | ||
876 | timeo = sock_sndtimeo(ssk, nonblock); | |
877 | retry: | |
878 | sk = netlink_getsockbypid(ssk, pid); | |
879 | if (IS_ERR(sk)) { | |
880 | kfree_skb(skb); | |
881 | return PTR_ERR(sk); | |
882 | } | |
cd40b7d3 DL |
883 | if (netlink_is_kernel(sk)) |
884 | return netlink_unicast_kernel(sk, skb); | |
885 | ||
c3d8d1e3 | 886 | err = netlink_attachskb(sk, skb, nonblock, &timeo, ssk); |
1da177e4 LT |
887 | if (err == 1) |
888 | goto retry; | |
889 | if (err) | |
890 | return err; | |
891 | ||
7ee015e0 | 892 | return netlink_sendskb(sk, skb); |
1da177e4 | 893 | } |
6ac552fd | 894 | EXPORT_SYMBOL(netlink_unicast); |
1da177e4 | 895 | |
4277a083 PM |
896 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
897 | { | |
898 | int res = 0; | |
b4ff4f04 | 899 | unsigned long *listeners; |
4277a083 | 900 | |
aed81560 | 901 | BUG_ON(!netlink_is_kernel(sk)); |
b4ff4f04 JB |
902 | |
903 | rcu_read_lock(); | |
904 | listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); | |
905 | ||
4277a083 | 906 | if (group - 1 < nl_table[sk->sk_protocol].groups) |
b4ff4f04 JB |
907 | res = test_bit(group - 1, listeners); |
908 | ||
909 | rcu_read_unlock(); | |
910 | ||
4277a083 PM |
911 | return res; |
912 | } | |
913 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
914 | ||
6ac552fd PM |
915 | static inline int netlink_broadcast_deliver(struct sock *sk, |
916 | struct sk_buff *skb) | |
1da177e4 LT |
917 | { |
918 | struct netlink_sock *nlk = nlk_sk(sk); | |
919 | ||
920 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
921 | !test_bit(0, &nlk->state)) { | |
922 | skb_set_owner_r(skb, sk); | |
923 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
924 | sk->sk_data_ready(sk, skb->len); | |
925 | return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf; | |
926 | } | |
927 | return -1; | |
928 | } | |
929 | ||
930 | struct netlink_broadcast_data { | |
931 | struct sock *exclude_sk; | |
b4b51029 | 932 | struct net *net; |
1da177e4 LT |
933 | u32 pid; |
934 | u32 group; | |
935 | int failure; | |
936 | int congested; | |
937 | int delivered; | |
7d877f3b | 938 | gfp_t allocation; |
1da177e4 LT |
939 | struct sk_buff *skb, *skb2; |
940 | }; | |
941 | ||
942 | static inline int do_one_broadcast(struct sock *sk, | |
943 | struct netlink_broadcast_data *p) | |
944 | { | |
945 | struct netlink_sock *nlk = nlk_sk(sk); | |
946 | int val; | |
947 | ||
948 | if (p->exclude_sk == sk) | |
949 | goto out; | |
950 | ||
f7fa9b10 PM |
951 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
952 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
953 | goto out; |
954 | ||
b4b51029 EB |
955 | if ((sk->sk_net != p->net)) |
956 | goto out; | |
957 | ||
1da177e4 LT |
958 | if (p->failure) { |
959 | netlink_overrun(sk); | |
960 | goto out; | |
961 | } | |
962 | ||
963 | sock_hold(sk); | |
964 | if (p->skb2 == NULL) { | |
68acc024 | 965 | if (skb_shared(p->skb)) { |
1da177e4 LT |
966 | p->skb2 = skb_clone(p->skb, p->allocation); |
967 | } else { | |
68acc024 TC |
968 | p->skb2 = skb_get(p->skb); |
969 | /* | |
970 | * skb ownership may have been set when | |
971 | * delivered to a previous socket. | |
972 | */ | |
973 | skb_orphan(p->skb2); | |
1da177e4 LT |
974 | } |
975 | } | |
976 | if (p->skb2 == NULL) { | |
977 | netlink_overrun(sk); | |
978 | /* Clone failed. Notify ALL listeners. */ | |
979 | p->failure = 1; | |
980 | } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) { | |
981 | netlink_overrun(sk); | |
982 | } else { | |
983 | p->congested |= val; | |
984 | p->delivered = 1; | |
985 | p->skb2 = NULL; | |
986 | } | |
987 | sock_put(sk); | |
988 | ||
989 | out: | |
990 | return 0; | |
991 | } | |
992 | ||
993 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid, | |
dd0fc66f | 994 | u32 group, gfp_t allocation) |
1da177e4 | 995 | { |
b4b51029 | 996 | struct net *net = ssk->sk_net; |
1da177e4 LT |
997 | struct netlink_broadcast_data info; |
998 | struct hlist_node *node; | |
999 | struct sock *sk; | |
1000 | ||
1001 | skb = netlink_trim(skb, allocation); | |
1002 | ||
1003 | info.exclude_sk = ssk; | |
b4b51029 | 1004 | info.net = net; |
1da177e4 LT |
1005 | info.pid = pid; |
1006 | info.group = group; | |
1007 | info.failure = 0; | |
1008 | info.congested = 0; | |
1009 | info.delivered = 0; | |
1010 | info.allocation = allocation; | |
1011 | info.skb = skb; | |
1012 | info.skb2 = NULL; | |
1013 | ||
1014 | /* While we sleep in clone, do not allow to change socket list */ | |
1015 | ||
1016 | netlink_lock_table(); | |
1017 | ||
1018 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1019 | do_one_broadcast(sk, &info); | |
1020 | ||
aa1c6a6f TC |
1021 | kfree_skb(skb); |
1022 | ||
1da177e4 LT |
1023 | netlink_unlock_table(); |
1024 | ||
1025 | if (info.skb2) | |
1026 | kfree_skb(info.skb2); | |
1da177e4 LT |
1027 | |
1028 | if (info.delivered) { | |
1029 | if (info.congested && (allocation & __GFP_WAIT)) | |
1030 | yield(); | |
1031 | return 0; | |
1032 | } | |
1033 | if (info.failure) | |
1034 | return -ENOBUFS; | |
1035 | return -ESRCH; | |
1036 | } | |
6ac552fd | 1037 | EXPORT_SYMBOL(netlink_broadcast); |
1da177e4 LT |
1038 | |
1039 | struct netlink_set_err_data { | |
1040 | struct sock *exclude_sk; | |
1041 | u32 pid; | |
1042 | u32 group; | |
1043 | int code; | |
1044 | }; | |
1045 | ||
1046 | static inline int do_one_set_err(struct sock *sk, | |
1047 | struct netlink_set_err_data *p) | |
1048 | { | |
1049 | struct netlink_sock *nlk = nlk_sk(sk); | |
1050 | ||
1051 | if (sk == p->exclude_sk) | |
1052 | goto out; | |
1053 | ||
b4b51029 EB |
1054 | if (sk->sk_net != p->exclude_sk->sk_net) |
1055 | goto out; | |
1056 | ||
f7fa9b10 PM |
1057 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
1058 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
1059 | goto out; |
1060 | ||
1061 | sk->sk_err = p->code; | |
1062 | sk->sk_error_report(sk); | |
1063 | out: | |
1064 | return 0; | |
1065 | } | |
1066 | ||
1067 | void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) | |
1068 | { | |
1069 | struct netlink_set_err_data info; | |
1070 | struct hlist_node *node; | |
1071 | struct sock *sk; | |
1072 | ||
1073 | info.exclude_sk = ssk; | |
1074 | info.pid = pid; | |
1075 | info.group = group; | |
1076 | info.code = code; | |
1077 | ||
1078 | read_lock(&nl_table_lock); | |
1079 | ||
1080 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1081 | do_one_set_err(sk, &info); | |
1082 | ||
1083 | read_unlock(&nl_table_lock); | |
1084 | } | |
1085 | ||
84659eb5 JB |
1086 | /* must be called with netlink table grabbed */ |
1087 | static void netlink_update_socket_mc(struct netlink_sock *nlk, | |
1088 | unsigned int group, | |
1089 | int is_new) | |
1090 | { | |
1091 | int old, new = !!is_new, subscriptions; | |
1092 | ||
1093 | old = test_bit(group - 1, nlk->groups); | |
1094 | subscriptions = nlk->subscriptions - old + new; | |
1095 | if (new) | |
1096 | __set_bit(group - 1, nlk->groups); | |
1097 | else | |
1098 | __clear_bit(group - 1, nlk->groups); | |
1099 | netlink_update_subscriptions(&nlk->sk, subscriptions); | |
1100 | netlink_update_listeners(&nlk->sk); | |
1101 | } | |
1102 | ||
9a4595bc | 1103 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
746fac4d | 1104 | char __user *optval, int optlen) |
9a4595bc PM |
1105 | { |
1106 | struct sock *sk = sock->sk; | |
1107 | struct netlink_sock *nlk = nlk_sk(sk); | |
eb496534 JB |
1108 | unsigned int val = 0; |
1109 | int err; | |
9a4595bc PM |
1110 | |
1111 | if (level != SOL_NETLINK) | |
1112 | return -ENOPROTOOPT; | |
1113 | ||
1114 | if (optlen >= sizeof(int) && | |
eb496534 | 1115 | get_user(val, (unsigned int __user *)optval)) |
9a4595bc PM |
1116 | return -EFAULT; |
1117 | ||
1118 | switch (optname) { | |
1119 | case NETLINK_PKTINFO: | |
1120 | if (val) | |
1121 | nlk->flags |= NETLINK_RECV_PKTINFO; | |
1122 | else | |
1123 | nlk->flags &= ~NETLINK_RECV_PKTINFO; | |
1124 | err = 0; | |
1125 | break; | |
1126 | case NETLINK_ADD_MEMBERSHIP: | |
1127 | case NETLINK_DROP_MEMBERSHIP: { | |
9a4595bc PM |
1128 | if (!netlink_capable(sock, NL_NONROOT_RECV)) |
1129 | return -EPERM; | |
b4ff4f04 JB |
1130 | err = netlink_realloc_groups(sk); |
1131 | if (err) | |
1132 | return err; | |
9a4595bc PM |
1133 | if (!val || val - 1 >= nlk->ngroups) |
1134 | return -EINVAL; | |
1135 | netlink_table_grab(); | |
84659eb5 JB |
1136 | netlink_update_socket_mc(nlk, val, |
1137 | optname == NETLINK_ADD_MEMBERSHIP); | |
9a4595bc PM |
1138 | netlink_table_ungrab(); |
1139 | err = 0; | |
1140 | break; | |
1141 | } | |
1142 | default: | |
1143 | err = -ENOPROTOOPT; | |
1144 | } | |
1145 | return err; | |
1146 | } | |
1147 | ||
1148 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
746fac4d | 1149 | char __user *optval, int __user *optlen) |
9a4595bc PM |
1150 | { |
1151 | struct sock *sk = sock->sk; | |
1152 | struct netlink_sock *nlk = nlk_sk(sk); | |
1153 | int len, val, err; | |
1154 | ||
1155 | if (level != SOL_NETLINK) | |
1156 | return -ENOPROTOOPT; | |
1157 | ||
1158 | if (get_user(len, optlen)) | |
1159 | return -EFAULT; | |
1160 | if (len < 0) | |
1161 | return -EINVAL; | |
1162 | ||
1163 | switch (optname) { | |
1164 | case NETLINK_PKTINFO: | |
1165 | if (len < sizeof(int)) | |
1166 | return -EINVAL; | |
1167 | len = sizeof(int); | |
1168 | val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0; | |
a27b58fe HC |
1169 | if (put_user(len, optlen) || |
1170 | put_user(val, optval)) | |
1171 | return -EFAULT; | |
9a4595bc PM |
1172 | err = 0; |
1173 | break; | |
1174 | default: | |
1175 | err = -ENOPROTOOPT; | |
1176 | } | |
1177 | return err; | |
1178 | } | |
1179 | ||
1180 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
1181 | { | |
1182 | struct nl_pktinfo info; | |
1183 | ||
1184 | info.group = NETLINK_CB(skb).dst_group; | |
1185 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
1186 | } | |
1187 | ||
1da177e4 LT |
1188 | static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, |
1189 | struct msghdr *msg, size_t len) | |
1190 | { | |
1191 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1192 | struct sock *sk = sock->sk; | |
1193 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 1194 | struct sockaddr_nl *addr = msg->msg_name; |
1da177e4 | 1195 | u32 dst_pid; |
d629b836 | 1196 | u32 dst_group; |
1da177e4 LT |
1197 | struct sk_buff *skb; |
1198 | int err; | |
1199 | struct scm_cookie scm; | |
1200 | ||
1201 | if (msg->msg_flags&MSG_OOB) | |
1202 | return -EOPNOTSUPP; | |
1203 | ||
1204 | if (NULL == siocb->scm) | |
1205 | siocb->scm = &scm; | |
1206 | err = scm_send(sock, msg, siocb->scm); | |
1207 | if (err < 0) | |
1208 | return err; | |
1209 | ||
1210 | if (msg->msg_namelen) { | |
1211 | if (addr->nl_family != AF_NETLINK) | |
1212 | return -EINVAL; | |
1213 | dst_pid = addr->nl_pid; | |
d629b836 PM |
1214 | dst_group = ffs(addr->nl_groups); |
1215 | if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND)) | |
1da177e4 LT |
1216 | return -EPERM; |
1217 | } else { | |
1218 | dst_pid = nlk->dst_pid; | |
d629b836 | 1219 | dst_group = nlk->dst_group; |
1da177e4 LT |
1220 | } |
1221 | ||
1222 | if (!nlk->pid) { | |
1223 | err = netlink_autobind(sock); | |
1224 | if (err) | |
1225 | goto out; | |
1226 | } | |
1227 | ||
1228 | err = -EMSGSIZE; | |
1229 | if (len > sk->sk_sndbuf - 32) | |
1230 | goto out; | |
1231 | err = -ENOBUFS; | |
339bf98f | 1232 | skb = alloc_skb(len, GFP_KERNEL); |
6ac552fd | 1233 | if (skb == NULL) |
1da177e4 LT |
1234 | goto out; |
1235 | ||
1236 | NETLINK_CB(skb).pid = nlk->pid; | |
d629b836 | 1237 | NETLINK_CB(skb).dst_group = dst_group; |
c94c257c | 1238 | NETLINK_CB(skb).loginuid = audit_get_loginuid(current->audit_context); |
e7c34970 | 1239 | selinux_get_task_sid(current, &(NETLINK_CB(skb).sid)); |
1da177e4 LT |
1240 | memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); |
1241 | ||
1242 | /* What can I do? Netlink is asynchronous, so that | |
1243 | we will have to save current capabilities to | |
1244 | check them, when this message will be delivered | |
1245 | to corresponding kernel module. --ANK (980802) | |
1246 | */ | |
1247 | ||
1248 | err = -EFAULT; | |
6ac552fd | 1249 | if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) { |
1da177e4 LT |
1250 | kfree_skb(skb); |
1251 | goto out; | |
1252 | } | |
1253 | ||
1254 | err = security_netlink_send(sk, skb); | |
1255 | if (err) { | |
1256 | kfree_skb(skb); | |
1257 | goto out; | |
1258 | } | |
1259 | ||
d629b836 | 1260 | if (dst_group) { |
1da177e4 | 1261 | atomic_inc(&skb->users); |
d629b836 | 1262 | netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL); |
1da177e4 LT |
1263 | } |
1264 | err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT); | |
1265 | ||
1266 | out: | |
1267 | return err; | |
1268 | } | |
1269 | ||
1270 | static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, | |
1271 | struct msghdr *msg, size_t len, | |
1272 | int flags) | |
1273 | { | |
1274 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1275 | struct scm_cookie scm; | |
1276 | struct sock *sk = sock->sk; | |
1277 | struct netlink_sock *nlk = nlk_sk(sk); | |
1278 | int noblock = flags&MSG_DONTWAIT; | |
1279 | size_t copied; | |
1280 | struct sk_buff *skb; | |
1281 | int err; | |
1282 | ||
1283 | if (flags&MSG_OOB) | |
1284 | return -EOPNOTSUPP; | |
1285 | ||
1286 | copied = 0; | |
1287 | ||
6ac552fd PM |
1288 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
1289 | if (skb == NULL) | |
1da177e4 LT |
1290 | goto out; |
1291 | ||
1292 | msg->msg_namelen = 0; | |
1293 | ||
1294 | copied = skb->len; | |
1295 | if (len < copied) { | |
1296 | msg->msg_flags |= MSG_TRUNC; | |
1297 | copied = len; | |
1298 | } | |
1299 | ||
badff6d0 | 1300 | skb_reset_transport_header(skb); |
1da177e4 LT |
1301 | err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); |
1302 | ||
1303 | if (msg->msg_name) { | |
6ac552fd | 1304 | struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name; |
1da177e4 LT |
1305 | addr->nl_family = AF_NETLINK; |
1306 | addr->nl_pad = 0; | |
1307 | addr->nl_pid = NETLINK_CB(skb).pid; | |
d629b836 | 1308 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
1309 | msg->msg_namelen = sizeof(*addr); |
1310 | } | |
1311 | ||
cc9a06cd PM |
1312 | if (nlk->flags & NETLINK_RECV_PKTINFO) |
1313 | netlink_cmsg_recv_pktinfo(msg, skb); | |
1314 | ||
1da177e4 LT |
1315 | if (NULL == siocb->scm) { |
1316 | memset(&scm, 0, sizeof(scm)); | |
1317 | siocb->scm = &scm; | |
1318 | } | |
1319 | siocb->scm->creds = *NETLINK_CREDS(skb); | |
188ccb55 PM |
1320 | if (flags & MSG_TRUNC) |
1321 | copied = skb->len; | |
1da177e4 LT |
1322 | skb_free_datagram(sk, skb); |
1323 | ||
1324 | if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) | |
1325 | netlink_dump(sk); | |
1326 | ||
1327 | scm_recv(sock, msg, siocb->scm, flags); | |
1da177e4 LT |
1328 | out: |
1329 | netlink_rcv_wake(sk); | |
1330 | return err ? : copied; | |
1331 | } | |
1332 | ||
1333 | static void netlink_data_ready(struct sock *sk, int len) | |
1334 | { | |
cd40b7d3 | 1335 | BUG(); |
1da177e4 LT |
1336 | } |
1337 | ||
1338 | /* | |
746fac4d | 1339 | * We export these functions to other modules. They provide a |
1da177e4 LT |
1340 | * complete set of kernel non-blocking support for message |
1341 | * queueing. | |
1342 | */ | |
1343 | ||
1344 | struct sock * | |
b4b51029 | 1345 | netlink_kernel_create(struct net *net, int unit, unsigned int groups, |
cd40b7d3 | 1346 | void (*input)(struct sk_buff *skb), |
af65bdfc | 1347 | struct mutex *cb_mutex, struct module *module) |
1da177e4 LT |
1348 | { |
1349 | struct socket *sock; | |
1350 | struct sock *sk; | |
77247bbb | 1351 | struct netlink_sock *nlk; |
4277a083 | 1352 | unsigned long *listeners = NULL; |
1da177e4 | 1353 | |
fab2caf6 | 1354 | BUG_ON(!nl_table); |
1da177e4 | 1355 | |
6ac552fd | 1356 | if (unit < 0 || unit >= MAX_LINKS) |
1da177e4 LT |
1357 | return NULL; |
1358 | ||
1359 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
1360 | return NULL; | |
1361 | ||
b4b51029 | 1362 | if (__netlink_create(net, sock, cb_mutex, unit) < 0) |
77247bbb | 1363 | goto out_sock_release; |
4fdb3bb7 | 1364 | |
4277a083 PM |
1365 | if (groups < 32) |
1366 | groups = 32; | |
1367 | ||
1368 | listeners = kzalloc(NLGRPSZ(groups), GFP_KERNEL); | |
1369 | if (!listeners) | |
1370 | goto out_sock_release; | |
1371 | ||
1da177e4 LT |
1372 | sk = sock->sk; |
1373 | sk->sk_data_ready = netlink_data_ready; | |
1374 | if (input) | |
cd40b7d3 | 1375 | nlk_sk(sk)->netlink_rcv = input; |
1da177e4 | 1376 | |
b4b51029 | 1377 | if (netlink_insert(sk, net, 0)) |
77247bbb | 1378 | goto out_sock_release; |
4fdb3bb7 | 1379 | |
77247bbb PM |
1380 | nlk = nlk_sk(sk); |
1381 | nlk->flags |= NETLINK_KERNEL_SOCKET; | |
4fdb3bb7 | 1382 | |
4fdb3bb7 | 1383 | netlink_table_grab(); |
b4b51029 EB |
1384 | if (!nl_table[unit].registered) { |
1385 | nl_table[unit].groups = groups; | |
1386 | nl_table[unit].listeners = listeners; | |
1387 | nl_table[unit].cb_mutex = cb_mutex; | |
1388 | nl_table[unit].module = module; | |
1389 | nl_table[unit].registered = 1; | |
f937f1f4 JJ |
1390 | } else { |
1391 | kfree(listeners); | |
b4b51029 | 1392 | } |
4fdb3bb7 | 1393 | netlink_table_ungrab(); |
77247bbb PM |
1394 | |
1395 | return sk; | |
1396 | ||
4fdb3bb7 | 1397 | out_sock_release: |
4277a083 | 1398 | kfree(listeners); |
4fdb3bb7 | 1399 | sock_release(sock); |
77247bbb | 1400 | return NULL; |
1da177e4 | 1401 | } |
6ac552fd | 1402 | EXPORT_SYMBOL(netlink_kernel_create); |
1da177e4 | 1403 | |
b4ff4f04 JB |
1404 | /** |
1405 | * netlink_change_ngroups - change number of multicast groups | |
1406 | * | |
1407 | * This changes the number of multicast groups that are available | |
1408 | * on a certain netlink family. Note that it is not possible to | |
84659eb5 JB |
1409 | * change the number of groups to below 32. Also note that it does |
1410 | * not implicitly call netlink_clear_multicast_users() when the | |
1411 | * number of groups is reduced. | |
b4ff4f04 JB |
1412 | * |
1413 | * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). | |
1414 | * @groups: The new number of groups. | |
1415 | */ | |
1416 | int netlink_change_ngroups(struct sock *sk, unsigned int groups) | |
1417 | { | |
1418 | unsigned long *listeners, *old = NULL; | |
1419 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
1420 | int err = 0; | |
1421 | ||
1422 | if (groups < 32) | |
1423 | groups = 32; | |
1424 | ||
1425 | netlink_table_grab(); | |
1426 | if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { | |
1427 | listeners = kzalloc(NLGRPSZ(groups), GFP_ATOMIC); | |
1428 | if (!listeners) { | |
1429 | err = -ENOMEM; | |
1430 | goto out_ungrab; | |
1431 | } | |
1432 | old = tbl->listeners; | |
1433 | memcpy(listeners, old, NLGRPSZ(tbl->groups)); | |
1434 | rcu_assign_pointer(tbl->listeners, listeners); | |
1435 | } | |
1436 | tbl->groups = groups; | |
1437 | ||
1438 | out_ungrab: | |
1439 | netlink_table_ungrab(); | |
1440 | synchronize_rcu(); | |
1441 | kfree(old); | |
1442 | return err; | |
1443 | } | |
1444 | EXPORT_SYMBOL(netlink_change_ngroups); | |
1445 | ||
84659eb5 JB |
1446 | /** |
1447 | * netlink_clear_multicast_users - kick off multicast listeners | |
1448 | * | |
1449 | * This function removes all listeners from the given group. | |
1450 | * @ksk: The kernel netlink socket, as returned by | |
1451 | * netlink_kernel_create(). | |
1452 | * @group: The multicast group to clear. | |
1453 | */ | |
1454 | void netlink_clear_multicast_users(struct sock *ksk, unsigned int group) | |
1455 | { | |
1456 | struct sock *sk; | |
1457 | struct hlist_node *node; | |
1458 | struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; | |
1459 | ||
1460 | netlink_table_grab(); | |
1461 | ||
1462 | sk_for_each_bound(sk, node, &tbl->mc_list) | |
1463 | netlink_update_socket_mc(nlk_sk(sk), group, 0); | |
1464 | ||
1465 | netlink_table_ungrab(); | |
1466 | } | |
1467 | EXPORT_SYMBOL(netlink_clear_multicast_users); | |
1468 | ||
1da177e4 | 1469 | void netlink_set_nonroot(int protocol, unsigned int flags) |
746fac4d YH |
1470 | { |
1471 | if ((unsigned int)protocol < MAX_LINKS) | |
1da177e4 | 1472 | nl_table[protocol].nl_nonroot = flags; |
746fac4d | 1473 | } |
6ac552fd | 1474 | EXPORT_SYMBOL(netlink_set_nonroot); |
1da177e4 LT |
1475 | |
1476 | static void netlink_destroy_callback(struct netlink_callback *cb) | |
1477 | { | |
1478 | if (cb->skb) | |
1479 | kfree_skb(cb->skb); | |
1480 | kfree(cb); | |
1481 | } | |
1482 | ||
1483 | /* | |
1484 | * It looks a bit ugly. | |
1485 | * It would be better to create kernel thread. | |
1486 | */ | |
1487 | ||
1488 | static int netlink_dump(struct sock *sk) | |
1489 | { | |
1490 | struct netlink_sock *nlk = nlk_sk(sk); | |
1491 | struct netlink_callback *cb; | |
1492 | struct sk_buff *skb; | |
1493 | struct nlmsghdr *nlh; | |
bf8b79e4 | 1494 | int len, err = -ENOBUFS; |
746fac4d | 1495 | |
1da177e4 LT |
1496 | skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL); |
1497 | if (!skb) | |
bf8b79e4 | 1498 | goto errout; |
1da177e4 | 1499 | |
af65bdfc | 1500 | mutex_lock(nlk->cb_mutex); |
1da177e4 LT |
1501 | |
1502 | cb = nlk->cb; | |
1503 | if (cb == NULL) { | |
bf8b79e4 TG |
1504 | err = -EINVAL; |
1505 | goto errout_skb; | |
1da177e4 LT |
1506 | } |
1507 | ||
1508 | len = cb->dump(skb, cb); | |
1509 | ||
1510 | if (len > 0) { | |
af65bdfc | 1511 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1512 | skb_queue_tail(&sk->sk_receive_queue, skb); |
1513 | sk->sk_data_ready(sk, len); | |
1514 | return 0; | |
1515 | } | |
1516 | ||
bf8b79e4 TG |
1517 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); |
1518 | if (!nlh) | |
1519 | goto errout_skb; | |
1520 | ||
1521 | memcpy(nlmsg_data(nlh), &len, sizeof(len)); | |
1522 | ||
1da177e4 LT |
1523 | skb_queue_tail(&sk->sk_receive_queue, skb); |
1524 | sk->sk_data_ready(sk, skb->len); | |
1525 | ||
a8f74b22 TG |
1526 | if (cb->done) |
1527 | cb->done(cb); | |
1da177e4 | 1528 | nlk->cb = NULL; |
af65bdfc | 1529 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1530 | |
1531 | netlink_destroy_callback(cb); | |
1da177e4 | 1532 | return 0; |
1797754e | 1533 | |
bf8b79e4 | 1534 | errout_skb: |
af65bdfc | 1535 | mutex_unlock(nlk->cb_mutex); |
bf8b79e4 TG |
1536 | kfree_skb(skb); |
1537 | errout: | |
1538 | return err; | |
1da177e4 LT |
1539 | } |
1540 | ||
1541 | int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, | |
1542 | struct nlmsghdr *nlh, | |
6ac552fd PM |
1543 | int (*dump)(struct sk_buff *skb, |
1544 | struct netlink_callback *), | |
1545 | int (*done)(struct netlink_callback *)) | |
1da177e4 LT |
1546 | { |
1547 | struct netlink_callback *cb; | |
1548 | struct sock *sk; | |
1549 | struct netlink_sock *nlk; | |
1550 | ||
0da974f4 | 1551 | cb = kzalloc(sizeof(*cb), GFP_KERNEL); |
1da177e4 LT |
1552 | if (cb == NULL) |
1553 | return -ENOBUFS; | |
1554 | ||
1da177e4 LT |
1555 | cb->dump = dump; |
1556 | cb->done = done; | |
1557 | cb->nlh = nlh; | |
1558 | atomic_inc(&skb->users); | |
1559 | cb->skb = skb; | |
1560 | ||
b4b51029 | 1561 | sk = netlink_lookup(ssk->sk_net, ssk->sk_protocol, NETLINK_CB(skb).pid); |
1da177e4 LT |
1562 | if (sk == NULL) { |
1563 | netlink_destroy_callback(cb); | |
1564 | return -ECONNREFUSED; | |
1565 | } | |
1566 | nlk = nlk_sk(sk); | |
3f660d66 | 1567 | /* A dump is in progress... */ |
af65bdfc | 1568 | mutex_lock(nlk->cb_mutex); |
3f660d66 | 1569 | if (nlk->cb) { |
af65bdfc | 1570 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1571 | netlink_destroy_callback(cb); |
1572 | sock_put(sk); | |
1573 | return -EBUSY; | |
1574 | } | |
1575 | nlk->cb = cb; | |
af65bdfc | 1576 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1577 | |
1578 | netlink_dump(sk); | |
1579 | sock_put(sk); | |
5c58298c DL |
1580 | |
1581 | /* We successfully started a dump, by returning -EINTR we | |
1582 | * signal not to send ACK even if it was requested. | |
1583 | */ | |
1584 | return -EINTR; | |
1da177e4 | 1585 | } |
6ac552fd | 1586 | EXPORT_SYMBOL(netlink_dump_start); |
1da177e4 LT |
1587 | |
1588 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) | |
1589 | { | |
1590 | struct sk_buff *skb; | |
1591 | struct nlmsghdr *rep; | |
1592 | struct nlmsgerr *errmsg; | |
339bf98f | 1593 | size_t payload = sizeof(*errmsg); |
1da177e4 | 1594 | |
339bf98f TG |
1595 | /* error messages get the original request appened */ |
1596 | if (err) | |
1597 | payload += nlmsg_len(nlh); | |
1da177e4 | 1598 | |
339bf98f | 1599 | skb = nlmsg_new(payload, GFP_KERNEL); |
1da177e4 LT |
1600 | if (!skb) { |
1601 | struct sock *sk; | |
1602 | ||
b4b51029 EB |
1603 | sk = netlink_lookup(in_skb->sk->sk_net, |
1604 | in_skb->sk->sk_protocol, | |
1da177e4 LT |
1605 | NETLINK_CB(in_skb).pid); |
1606 | if (sk) { | |
1607 | sk->sk_err = ENOBUFS; | |
1608 | sk->sk_error_report(sk); | |
1609 | sock_put(sk); | |
1610 | } | |
1611 | return; | |
1612 | } | |
1613 | ||
1614 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, | |
1797754e | 1615 | NLMSG_ERROR, sizeof(struct nlmsgerr), 0); |
bf8b79e4 | 1616 | errmsg = nlmsg_data(rep); |
1da177e4 | 1617 | errmsg->error = err; |
bf8b79e4 | 1618 | memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh)); |
1da177e4 LT |
1619 | netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT); |
1620 | } | |
6ac552fd | 1621 | EXPORT_SYMBOL(netlink_ack); |
1da177e4 | 1622 | |
cd40b7d3 | 1623 | int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
1d00a4eb | 1624 | struct nlmsghdr *)) |
82ace47a | 1625 | { |
82ace47a TG |
1626 | struct nlmsghdr *nlh; |
1627 | int err; | |
1628 | ||
1629 | while (skb->len >= nlmsg_total_size(0)) { | |
cd40b7d3 DL |
1630 | int msglen; |
1631 | ||
b529ccf2 | 1632 | nlh = nlmsg_hdr(skb); |
d35b6856 | 1633 | err = 0; |
82ace47a | 1634 | |
ad8e4b75 | 1635 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
1636 | return 0; |
1637 | ||
d35b6856 TG |
1638 | /* Only requests are handled by the kernel */ |
1639 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | |
5c58298c | 1640 | goto ack; |
45e7ae7f TG |
1641 | |
1642 | /* Skip control messages */ | |
1643 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | |
5c58298c | 1644 | goto ack; |
d35b6856 | 1645 | |
1d00a4eb | 1646 | err = cb(skb, nlh); |
5c58298c DL |
1647 | if (err == -EINTR) |
1648 | goto skip; | |
1649 | ||
1650 | ack: | |
d35b6856 | 1651 | if (nlh->nlmsg_flags & NLM_F_ACK || err) |
82ace47a | 1652 | netlink_ack(skb, nlh, err); |
82ace47a | 1653 | |
5c58298c | 1654 | skip: |
6ac552fd | 1655 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
cd40b7d3 DL |
1656 | if (msglen > skb->len) |
1657 | msglen = skb->len; | |
1658 | skb_pull(skb, msglen); | |
82ace47a TG |
1659 | } |
1660 | ||
1661 | return 0; | |
1662 | } | |
6ac552fd | 1663 | EXPORT_SYMBOL(netlink_rcv_skb); |
82ace47a | 1664 | |
d387f6ad TG |
1665 | /** |
1666 | * nlmsg_notify - send a notification netlink message | |
1667 | * @sk: netlink socket to use | |
1668 | * @skb: notification message | |
1669 | * @pid: destination netlink pid for reports or 0 | |
1670 | * @group: destination multicast group or 0 | |
1671 | * @report: 1 to report back, 0 to disable | |
1672 | * @flags: allocation flags | |
1673 | */ | |
1674 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid, | |
1675 | unsigned int group, int report, gfp_t flags) | |
1676 | { | |
1677 | int err = 0; | |
1678 | ||
1679 | if (group) { | |
1680 | int exclude_pid = 0; | |
1681 | ||
1682 | if (report) { | |
1683 | atomic_inc(&skb->users); | |
1684 | exclude_pid = pid; | |
1685 | } | |
1686 | ||
1687 | /* errors reported via destination sk->sk_err */ | |
1688 | nlmsg_multicast(sk, skb, exclude_pid, group, flags); | |
1689 | } | |
1690 | ||
1691 | if (report) | |
1692 | err = nlmsg_unicast(sk, skb, pid); | |
1693 | ||
1694 | return err; | |
1695 | } | |
6ac552fd | 1696 | EXPORT_SYMBOL(nlmsg_notify); |
d387f6ad | 1697 | |
1da177e4 LT |
1698 | #ifdef CONFIG_PROC_FS |
1699 | struct nl_seq_iter { | |
e372c414 | 1700 | struct seq_net_private p; |
1da177e4 LT |
1701 | int link; |
1702 | int hash_idx; | |
1703 | }; | |
1704 | ||
1705 | static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) | |
1706 | { | |
1707 | struct nl_seq_iter *iter = seq->private; | |
1708 | int i, j; | |
1709 | struct sock *s; | |
1710 | struct hlist_node *node; | |
1711 | loff_t off = 0; | |
1712 | ||
6ac552fd | 1713 | for (i = 0; i < MAX_LINKS; i++) { |
1da177e4 LT |
1714 | struct nl_pid_hash *hash = &nl_table[i].hash; |
1715 | ||
1716 | for (j = 0; j <= hash->mask; j++) { | |
1717 | sk_for_each(s, node, &hash->table[j]) { | |
e372c414 | 1718 | if (iter->p.net != s->sk_net) |
b4b51029 | 1719 | continue; |
1da177e4 LT |
1720 | if (off == pos) { |
1721 | iter->link = i; | |
1722 | iter->hash_idx = j; | |
1723 | return s; | |
1724 | } | |
1725 | ++off; | |
1726 | } | |
1727 | } | |
1728 | } | |
1729 | return NULL; | |
1730 | } | |
1731 | ||
1732 | static void *netlink_seq_start(struct seq_file *seq, loff_t *pos) | |
9a429c49 | 1733 | __acquires(nl_table_lock) |
1da177e4 LT |
1734 | { |
1735 | read_lock(&nl_table_lock); | |
1736 | return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
1737 | } | |
1738 | ||
1739 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
1740 | { | |
1741 | struct sock *s; | |
1742 | struct nl_seq_iter *iter; | |
1743 | int i, j; | |
1744 | ||
1745 | ++*pos; | |
1746 | ||
1747 | if (v == SEQ_START_TOKEN) | |
1748 | return netlink_seq_socket_idx(seq, 0); | |
746fac4d | 1749 | |
b4b51029 EB |
1750 | iter = seq->private; |
1751 | s = v; | |
1752 | do { | |
1753 | s = sk_next(s); | |
e372c414 | 1754 | } while (s && (iter->p.net != s->sk_net)); |
1da177e4 LT |
1755 | if (s) |
1756 | return s; | |
1757 | ||
1da177e4 LT |
1758 | i = iter->link; |
1759 | j = iter->hash_idx + 1; | |
1760 | ||
1761 | do { | |
1762 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1763 | ||
1764 | for (; j <= hash->mask; j++) { | |
1765 | s = sk_head(&hash->table[j]); | |
e372c414 | 1766 | while (s && (iter->p.net != s->sk_net)) |
b4b51029 | 1767 | s = sk_next(s); |
1da177e4 LT |
1768 | if (s) { |
1769 | iter->link = i; | |
1770 | iter->hash_idx = j; | |
1771 | return s; | |
1772 | } | |
1773 | } | |
1774 | ||
1775 | j = 0; | |
1776 | } while (++i < MAX_LINKS); | |
1777 | ||
1778 | return NULL; | |
1779 | } | |
1780 | ||
1781 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
9a429c49 | 1782 | __releases(nl_table_lock) |
1da177e4 LT |
1783 | { |
1784 | read_unlock(&nl_table_lock); | |
1785 | } | |
1786 | ||
1787 | ||
1788 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
1789 | { | |
1790 | if (v == SEQ_START_TOKEN) | |
1791 | seq_puts(seq, | |
1792 | "sk Eth Pid Groups " | |
1793 | "Rmem Wmem Dump Locks\n"); | |
1794 | else { | |
1795 | struct sock *s = v; | |
1796 | struct netlink_sock *nlk = nlk_sk(s); | |
1797 | ||
1798 | seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %d\n", | |
1799 | s, | |
1800 | s->sk_protocol, | |
1801 | nlk->pid, | |
513c2500 | 1802 | nlk->groups ? (u32)nlk->groups[0] : 0, |
1da177e4 LT |
1803 | atomic_read(&s->sk_rmem_alloc), |
1804 | atomic_read(&s->sk_wmem_alloc), | |
1805 | nlk->cb, | |
1806 | atomic_read(&s->sk_refcnt) | |
1807 | ); | |
1808 | ||
1809 | } | |
1810 | return 0; | |
1811 | } | |
1812 | ||
56b3d975 | 1813 | static const struct seq_operations netlink_seq_ops = { |
1da177e4 LT |
1814 | .start = netlink_seq_start, |
1815 | .next = netlink_seq_next, | |
1816 | .stop = netlink_seq_stop, | |
1817 | .show = netlink_seq_show, | |
1818 | }; | |
1819 | ||
1820 | ||
1821 | static int netlink_seq_open(struct inode *inode, struct file *file) | |
1822 | { | |
e372c414 DL |
1823 | return seq_open_net(inode, file, &netlink_seq_ops, |
1824 | sizeof(struct nl_seq_iter)); | |
b4b51029 EB |
1825 | } |
1826 | ||
da7071d7 | 1827 | static const struct file_operations netlink_seq_fops = { |
1da177e4 LT |
1828 | .owner = THIS_MODULE, |
1829 | .open = netlink_seq_open, | |
1830 | .read = seq_read, | |
1831 | .llseek = seq_lseek, | |
e372c414 | 1832 | .release = seq_release_net, |
1da177e4 LT |
1833 | }; |
1834 | ||
1835 | #endif | |
1836 | ||
1837 | int netlink_register_notifier(struct notifier_block *nb) | |
1838 | { | |
e041c683 | 1839 | return atomic_notifier_chain_register(&netlink_chain, nb); |
1da177e4 | 1840 | } |
6ac552fd | 1841 | EXPORT_SYMBOL(netlink_register_notifier); |
1da177e4 LT |
1842 | |
1843 | int netlink_unregister_notifier(struct notifier_block *nb) | |
1844 | { | |
e041c683 | 1845 | return atomic_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 | 1846 | } |
6ac552fd | 1847 | EXPORT_SYMBOL(netlink_unregister_notifier); |
746fac4d | 1848 | |
90ddc4f0 | 1849 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
1850 | .family = PF_NETLINK, |
1851 | .owner = THIS_MODULE, | |
1852 | .release = netlink_release, | |
1853 | .bind = netlink_bind, | |
1854 | .connect = netlink_connect, | |
1855 | .socketpair = sock_no_socketpair, | |
1856 | .accept = sock_no_accept, | |
1857 | .getname = netlink_getname, | |
1858 | .poll = datagram_poll, | |
1859 | .ioctl = sock_no_ioctl, | |
1860 | .listen = sock_no_listen, | |
1861 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
1862 | .setsockopt = netlink_setsockopt, |
1863 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
1864 | .sendmsg = netlink_sendmsg, |
1865 | .recvmsg = netlink_recvmsg, | |
1866 | .mmap = sock_no_mmap, | |
1867 | .sendpage = sock_no_sendpage, | |
1868 | }; | |
1869 | ||
1870 | static struct net_proto_family netlink_family_ops = { | |
1871 | .family = PF_NETLINK, | |
1872 | .create = netlink_create, | |
1873 | .owner = THIS_MODULE, /* for consistency 8) */ | |
1874 | }; | |
1875 | ||
4665079c | 1876 | static int __net_init netlink_net_init(struct net *net) |
b4b51029 EB |
1877 | { |
1878 | #ifdef CONFIG_PROC_FS | |
1879 | if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops)) | |
1880 | return -ENOMEM; | |
1881 | #endif | |
1882 | return 0; | |
1883 | } | |
1884 | ||
4665079c | 1885 | static void __net_exit netlink_net_exit(struct net *net) |
b4b51029 EB |
1886 | { |
1887 | #ifdef CONFIG_PROC_FS | |
1888 | proc_net_remove(net, "netlink"); | |
1889 | #endif | |
1890 | } | |
1891 | ||
022cbae6 | 1892 | static struct pernet_operations __net_initdata netlink_net_ops = { |
b4b51029 EB |
1893 | .init = netlink_net_init, |
1894 | .exit = netlink_net_exit, | |
1895 | }; | |
1896 | ||
1da177e4 LT |
1897 | static int __init netlink_proto_init(void) |
1898 | { | |
1899 | struct sk_buff *dummy_skb; | |
1900 | int i; | |
26ff5ddc | 1901 | unsigned long limit; |
1da177e4 LT |
1902 | unsigned int order; |
1903 | int err = proto_register(&netlink_proto, 0); | |
1904 | ||
1905 | if (err != 0) | |
1906 | goto out; | |
1907 | ||
ef047f5e | 1908 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb)); |
1da177e4 | 1909 | |
0da974f4 | 1910 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
1911 | if (!nl_table) |
1912 | goto panic; | |
1da177e4 | 1913 | |
1da177e4 | 1914 | if (num_physpages >= (128 * 1024)) |
26ff5ddc | 1915 | limit = num_physpages >> (21 - PAGE_SHIFT); |
1da177e4 | 1916 | else |
26ff5ddc | 1917 | limit = num_physpages >> (23 - PAGE_SHIFT); |
1da177e4 | 1918 | |
26ff5ddc DC |
1919 | order = get_bitmask_order(limit) - 1 + PAGE_SHIFT; |
1920 | limit = (1UL << order) / sizeof(struct hlist_head); | |
1921 | order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1; | |
1da177e4 LT |
1922 | |
1923 | for (i = 0; i < MAX_LINKS; i++) { | |
1924 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1925 | ||
ea72912c | 1926 | hash->table = nl_pid_hash_zalloc(1 * sizeof(*hash->table)); |
1da177e4 LT |
1927 | if (!hash->table) { |
1928 | while (i-- > 0) | |
1929 | nl_pid_hash_free(nl_table[i].hash.table, | |
1930 | 1 * sizeof(*hash->table)); | |
1931 | kfree(nl_table); | |
fab2caf6 | 1932 | goto panic; |
1da177e4 | 1933 | } |
1da177e4 LT |
1934 | hash->max_shift = order; |
1935 | hash->shift = 0; | |
1936 | hash->mask = 0; | |
1937 | hash->rehash_time = jiffies; | |
1938 | } | |
1939 | ||
1940 | sock_register(&netlink_family_ops); | |
b4b51029 | 1941 | register_pernet_subsys(&netlink_net_ops); |
746fac4d | 1942 | /* The netlink device handler may be needed early. */ |
1da177e4 LT |
1943 | rtnetlink_init(); |
1944 | out: | |
1945 | return err; | |
fab2caf6 AM |
1946 | panic: |
1947 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
1948 | } |
1949 | ||
1da177e4 | 1950 | core_initcall(netlink_proto_init); |