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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * NETLINK Kernel-user communication protocol. | |
3 | * | |
113aa838 | 4 | * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk> |
1da177e4 LT |
5 | * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
746fac4d | 11 | * |
1da177e4 LT |
12 | * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith |
13 | * added netlink_proto_exit | |
14 | * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br> | |
15 | * use nlk_sk, as sk->protinfo is on a diet 8) | |
4fdb3bb7 HW |
16 | * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org> |
17 | * - inc module use count of module that owns | |
18 | * the kernel socket in case userspace opens | |
19 | * socket of same protocol | |
20 | * - remove all module support, since netlink is | |
21 | * mandatory if CONFIG_NET=y these days | |
1da177e4 LT |
22 | */ |
23 | ||
1da177e4 LT |
24 | #include <linux/module.h> |
25 | ||
4fc268d2 | 26 | #include <linux/capability.h> |
1da177e4 LT |
27 | #include <linux/kernel.h> |
28 | #include <linux/init.h> | |
1da177e4 LT |
29 | #include <linux/signal.h> |
30 | #include <linux/sched.h> | |
31 | #include <linux/errno.h> | |
32 | #include <linux/string.h> | |
33 | #include <linux/stat.h> | |
34 | #include <linux/socket.h> | |
35 | #include <linux/un.h> | |
36 | #include <linux/fcntl.h> | |
37 | #include <linux/termios.h> | |
38 | #include <linux/sockios.h> | |
39 | #include <linux/net.h> | |
40 | #include <linux/fs.h> | |
41 | #include <linux/slab.h> | |
42 | #include <asm/uaccess.h> | |
43 | #include <linux/skbuff.h> | |
44 | #include <linux/netdevice.h> | |
45 | #include <linux/rtnetlink.h> | |
46 | #include <linux/proc_fs.h> | |
47 | #include <linux/seq_file.h> | |
1da177e4 LT |
48 | #include <linux/notifier.h> |
49 | #include <linux/security.h> | |
50 | #include <linux/jhash.h> | |
51 | #include <linux/jiffies.h> | |
52 | #include <linux/random.h> | |
53 | #include <linux/bitops.h> | |
54 | #include <linux/mm.h> | |
55 | #include <linux/types.h> | |
54e0f520 | 56 | #include <linux/audit.h> |
af65bdfc | 57 | #include <linux/mutex.h> |
54e0f520 | 58 | |
457c4cbc | 59 | #include <net/net_namespace.h> |
1da177e4 LT |
60 | #include <net/sock.h> |
61 | #include <net/scm.h> | |
82ace47a | 62 | #include <net/netlink.h> |
1da177e4 | 63 | |
f7fa9b10 | 64 | #define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8) |
b4ff4f04 | 65 | #define NLGRPLONGS(x) (NLGRPSZ(x)/sizeof(unsigned long)) |
1da177e4 LT |
66 | |
67 | struct netlink_sock { | |
68 | /* struct sock has to be the first member of netlink_sock */ | |
69 | struct sock sk; | |
15e47304 EB |
70 | u32 portid; |
71 | u32 dst_portid; | |
d629b836 | 72 | u32 dst_group; |
f7fa9b10 PM |
73 | u32 flags; |
74 | u32 subscriptions; | |
75 | u32 ngroups; | |
76 | unsigned long *groups; | |
1da177e4 LT |
77 | unsigned long state; |
78 | wait_queue_head_t wait; | |
79 | struct netlink_callback *cb; | |
af65bdfc PM |
80 | struct mutex *cb_mutex; |
81 | struct mutex cb_def_mutex; | |
cd40b7d3 | 82 | void (*netlink_rcv)(struct sk_buff *skb); |
03292745 | 83 | void (*netlink_bind)(int group); |
77247bbb | 84 | struct module *module; |
1da177e4 LT |
85 | }; |
86 | ||
5c398dc8 ED |
87 | struct listeners { |
88 | struct rcu_head rcu; | |
89 | unsigned long masks[0]; | |
6c04bb18 JB |
90 | }; |
91 | ||
77247bbb | 92 | #define NETLINK_KERNEL_SOCKET 0x1 |
9a4595bc | 93 | #define NETLINK_RECV_PKTINFO 0x2 |
be0c22a4 | 94 | #define NETLINK_BROADCAST_SEND_ERROR 0x4 |
38938bfe | 95 | #define NETLINK_RECV_NO_ENOBUFS 0x8 |
77247bbb | 96 | |
1da177e4 LT |
97 | static inline struct netlink_sock *nlk_sk(struct sock *sk) |
98 | { | |
32b21e03 | 99 | return container_of(sk, struct netlink_sock, sk); |
1da177e4 LT |
100 | } |
101 | ||
035c4c16 | 102 | static inline int netlink_is_kernel(struct sock *sk) |
aed81560 DL |
103 | { |
104 | return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET; | |
105 | } | |
106 | ||
15e47304 | 107 | struct nl_portid_hash { |
658cb354 ED |
108 | struct hlist_head *table; |
109 | unsigned long rehash_time; | |
1da177e4 | 110 | |
658cb354 ED |
111 | unsigned int mask; |
112 | unsigned int shift; | |
1da177e4 | 113 | |
658cb354 ED |
114 | unsigned int entries; |
115 | unsigned int max_shift; | |
1da177e4 | 116 | |
658cb354 | 117 | u32 rnd; |
1da177e4 LT |
118 | }; |
119 | ||
120 | struct netlink_table { | |
15e47304 | 121 | struct nl_portid_hash hash; |
658cb354 ED |
122 | struct hlist_head mc_list; |
123 | struct listeners __rcu *listeners; | |
9785e10a | 124 | unsigned int flags; |
658cb354 ED |
125 | unsigned int groups; |
126 | struct mutex *cb_mutex; | |
127 | struct module *module; | |
03292745 | 128 | void (*bind)(int group); |
658cb354 | 129 | int registered; |
1da177e4 LT |
130 | }; |
131 | ||
132 | static struct netlink_table *nl_table; | |
133 | ||
134 | static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); | |
135 | ||
136 | static int netlink_dump(struct sock *sk); | |
1da177e4 LT |
137 | |
138 | static DEFINE_RWLOCK(nl_table_lock); | |
139 | static atomic_t nl_table_users = ATOMIC_INIT(0); | |
140 | ||
6d772ac5 ED |
141 | #define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock)); |
142 | ||
e041c683 | 143 | static ATOMIC_NOTIFIER_HEAD(netlink_chain); |
1da177e4 | 144 | |
b57ef81f | 145 | static inline u32 netlink_group_mask(u32 group) |
d629b836 PM |
146 | { |
147 | return group ? 1 << (group - 1) : 0; | |
148 | } | |
149 | ||
15e47304 | 150 | static inline struct hlist_head *nl_portid_hashfn(struct nl_portid_hash *hash, u32 portid) |
1da177e4 | 151 | { |
15e47304 | 152 | return &hash->table[jhash_1word(portid, hash->rnd) & hash->mask]; |
1da177e4 LT |
153 | } |
154 | ||
658cb354 ED |
155 | static void netlink_destroy_callback(struct netlink_callback *cb) |
156 | { | |
157 | kfree_skb(cb->skb); | |
158 | kfree(cb); | |
159 | } | |
160 | ||
bfb253c9 ED |
161 | static void netlink_consume_callback(struct netlink_callback *cb) |
162 | { | |
163 | consume_skb(cb->skb); | |
164 | kfree(cb); | |
165 | } | |
166 | ||
1da177e4 LT |
167 | static void netlink_sock_destruct(struct sock *sk) |
168 | { | |
3f660d66 HX |
169 | struct netlink_sock *nlk = nlk_sk(sk); |
170 | ||
3f660d66 HX |
171 | if (nlk->cb) { |
172 | if (nlk->cb->done) | |
173 | nlk->cb->done(nlk->cb); | |
6dc878a8 G |
174 | |
175 | module_put(nlk->cb->module); | |
3f660d66 HX |
176 | netlink_destroy_callback(nlk->cb); |
177 | } | |
178 | ||
1da177e4 LT |
179 | skb_queue_purge(&sk->sk_receive_queue); |
180 | ||
181 | if (!sock_flag(sk, SOCK_DEAD)) { | |
6ac552fd | 182 | printk(KERN_ERR "Freeing alive netlink socket %p\n", sk); |
1da177e4 LT |
183 | return; |
184 | } | |
547b792c IJ |
185 | |
186 | WARN_ON(atomic_read(&sk->sk_rmem_alloc)); | |
187 | WARN_ON(atomic_read(&sk->sk_wmem_alloc)); | |
188 | WARN_ON(nlk_sk(sk)->groups); | |
1da177e4 LT |
189 | } |
190 | ||
6ac552fd PM |
191 | /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on |
192 | * SMP. Look, when several writers sleep and reader wakes them up, all but one | |
1da177e4 LT |
193 | * immediately hit write lock and grab all the cpus. Exclusive sleep solves |
194 | * this, _but_ remember, it adds useless work on UP machines. | |
195 | */ | |
196 | ||
d136f1bd | 197 | void netlink_table_grab(void) |
9a429c49 | 198 | __acquires(nl_table_lock) |
1da177e4 | 199 | { |
d136f1bd JB |
200 | might_sleep(); |
201 | ||
6abd219c | 202 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
203 | |
204 | if (atomic_read(&nl_table_users)) { | |
205 | DECLARE_WAITQUEUE(wait, current); | |
206 | ||
207 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
6ac552fd | 208 | for (;;) { |
1da177e4 LT |
209 | set_current_state(TASK_UNINTERRUPTIBLE); |
210 | if (atomic_read(&nl_table_users) == 0) | |
211 | break; | |
6abd219c | 212 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 213 | schedule(); |
6abd219c | 214 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
215 | } |
216 | ||
217 | __set_current_state(TASK_RUNNING); | |
218 | remove_wait_queue(&nl_table_wait, &wait); | |
219 | } | |
220 | } | |
221 | ||
d136f1bd | 222 | void netlink_table_ungrab(void) |
9a429c49 | 223 | __releases(nl_table_lock) |
1da177e4 | 224 | { |
6abd219c | 225 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
226 | wake_up(&nl_table_wait); |
227 | } | |
228 | ||
6ac552fd | 229 | static inline void |
1da177e4 LT |
230 | netlink_lock_table(void) |
231 | { | |
232 | /* read_lock() synchronizes us to netlink_table_grab */ | |
233 | ||
234 | read_lock(&nl_table_lock); | |
235 | atomic_inc(&nl_table_users); | |
236 | read_unlock(&nl_table_lock); | |
237 | } | |
238 | ||
6ac552fd | 239 | static inline void |
1da177e4 LT |
240 | netlink_unlock_table(void) |
241 | { | |
242 | if (atomic_dec_and_test(&nl_table_users)) | |
243 | wake_up(&nl_table_wait); | |
244 | } | |
245 | ||
15e47304 | 246 | static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid) |
1da177e4 | 247 | { |
15e47304 | 248 | struct nl_portid_hash *hash = &nl_table[protocol].hash; |
1da177e4 LT |
249 | struct hlist_head *head; |
250 | struct sock *sk; | |
251 | struct hlist_node *node; | |
252 | ||
253 | read_lock(&nl_table_lock); | |
15e47304 | 254 | head = nl_portid_hashfn(hash, portid); |
1da177e4 | 255 | sk_for_each(sk, node, head) { |
15e47304 | 256 | if (net_eq(sock_net(sk), net) && (nlk_sk(sk)->portid == portid)) { |
1da177e4 LT |
257 | sock_hold(sk); |
258 | goto found; | |
259 | } | |
260 | } | |
261 | sk = NULL; | |
262 | found: | |
263 | read_unlock(&nl_table_lock); | |
264 | return sk; | |
265 | } | |
266 | ||
15e47304 | 267 | static struct hlist_head *nl_portid_hash_zalloc(size_t size) |
1da177e4 LT |
268 | { |
269 | if (size <= PAGE_SIZE) | |
ea72912c | 270 | return kzalloc(size, GFP_ATOMIC); |
1da177e4 LT |
271 | else |
272 | return (struct hlist_head *) | |
ea72912c ED |
273 | __get_free_pages(GFP_ATOMIC | __GFP_ZERO, |
274 | get_order(size)); | |
1da177e4 LT |
275 | } |
276 | ||
15e47304 | 277 | static void nl_portid_hash_free(struct hlist_head *table, size_t size) |
1da177e4 LT |
278 | { |
279 | if (size <= PAGE_SIZE) | |
280 | kfree(table); | |
281 | else | |
282 | free_pages((unsigned long)table, get_order(size)); | |
283 | } | |
284 | ||
15e47304 | 285 | static int nl_portid_hash_rehash(struct nl_portid_hash *hash, int grow) |
1da177e4 LT |
286 | { |
287 | unsigned int omask, mask, shift; | |
288 | size_t osize, size; | |
289 | struct hlist_head *otable, *table; | |
290 | int i; | |
291 | ||
292 | omask = mask = hash->mask; | |
293 | osize = size = (mask + 1) * sizeof(*table); | |
294 | shift = hash->shift; | |
295 | ||
296 | if (grow) { | |
297 | if (++shift > hash->max_shift) | |
298 | return 0; | |
299 | mask = mask * 2 + 1; | |
300 | size *= 2; | |
301 | } | |
302 | ||
15e47304 | 303 | table = nl_portid_hash_zalloc(size); |
1da177e4 LT |
304 | if (!table) |
305 | return 0; | |
306 | ||
1da177e4 LT |
307 | otable = hash->table; |
308 | hash->table = table; | |
309 | hash->mask = mask; | |
310 | hash->shift = shift; | |
311 | get_random_bytes(&hash->rnd, sizeof(hash->rnd)); | |
312 | ||
313 | for (i = 0; i <= omask; i++) { | |
314 | struct sock *sk; | |
315 | struct hlist_node *node, *tmp; | |
316 | ||
317 | sk_for_each_safe(sk, node, tmp, &otable[i]) | |
15e47304 | 318 | __sk_add_node(sk, nl_portid_hashfn(hash, nlk_sk(sk)->portid)); |
1da177e4 LT |
319 | } |
320 | ||
15e47304 | 321 | nl_portid_hash_free(otable, osize); |
1da177e4 LT |
322 | hash->rehash_time = jiffies + 10 * 60 * HZ; |
323 | return 1; | |
324 | } | |
325 | ||
15e47304 | 326 | static inline int nl_portid_hash_dilute(struct nl_portid_hash *hash, int len) |
1da177e4 LT |
327 | { |
328 | int avg = hash->entries >> hash->shift; | |
329 | ||
15e47304 | 330 | if (unlikely(avg > 1) && nl_portid_hash_rehash(hash, 1)) |
1da177e4 LT |
331 | return 1; |
332 | ||
333 | if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) { | |
15e47304 | 334 | nl_portid_hash_rehash(hash, 0); |
1da177e4 LT |
335 | return 1; |
336 | } | |
337 | ||
338 | return 0; | |
339 | } | |
340 | ||
90ddc4f0 | 341 | static const struct proto_ops netlink_ops; |
1da177e4 | 342 | |
4277a083 PM |
343 | static void |
344 | netlink_update_listeners(struct sock *sk) | |
345 | { | |
346 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
347 | struct hlist_node *node; | |
348 | unsigned long mask; | |
349 | unsigned int i; | |
6d772ac5 ED |
350 | struct listeners *listeners; |
351 | ||
352 | listeners = nl_deref_protected(tbl->listeners); | |
353 | if (!listeners) | |
354 | return; | |
4277a083 | 355 | |
b4ff4f04 | 356 | for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
4277a083 | 357 | mask = 0; |
b4ff4f04 JB |
358 | sk_for_each_bound(sk, node, &tbl->mc_list) { |
359 | if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) | |
360 | mask |= nlk_sk(sk)->groups[i]; | |
361 | } | |
6d772ac5 | 362 | listeners->masks[i] = mask; |
4277a083 PM |
363 | } |
364 | /* this function is only called with the netlink table "grabbed", which | |
365 | * makes sure updates are visible before bind or setsockopt return. */ | |
366 | } | |
367 | ||
15e47304 | 368 | static int netlink_insert(struct sock *sk, struct net *net, u32 portid) |
1da177e4 | 369 | { |
15e47304 | 370 | struct nl_portid_hash *hash = &nl_table[sk->sk_protocol].hash; |
1da177e4 LT |
371 | struct hlist_head *head; |
372 | int err = -EADDRINUSE; | |
373 | struct sock *osk; | |
374 | struct hlist_node *node; | |
375 | int len; | |
376 | ||
377 | netlink_table_grab(); | |
15e47304 | 378 | head = nl_portid_hashfn(hash, portid); |
1da177e4 LT |
379 | len = 0; |
380 | sk_for_each(osk, node, head) { | |
15e47304 | 381 | if (net_eq(sock_net(osk), net) && (nlk_sk(osk)->portid == portid)) |
1da177e4 LT |
382 | break; |
383 | len++; | |
384 | } | |
385 | if (node) | |
386 | goto err; | |
387 | ||
388 | err = -EBUSY; | |
15e47304 | 389 | if (nlk_sk(sk)->portid) |
1da177e4 LT |
390 | goto err; |
391 | ||
392 | err = -ENOMEM; | |
393 | if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX)) | |
394 | goto err; | |
395 | ||
15e47304 EB |
396 | if (len && nl_portid_hash_dilute(hash, len)) |
397 | head = nl_portid_hashfn(hash, portid); | |
1da177e4 | 398 | hash->entries++; |
15e47304 | 399 | nlk_sk(sk)->portid = portid; |
1da177e4 LT |
400 | sk_add_node(sk, head); |
401 | err = 0; | |
402 | ||
403 | err: | |
404 | netlink_table_ungrab(); | |
405 | return err; | |
406 | } | |
407 | ||
408 | static void netlink_remove(struct sock *sk) | |
409 | { | |
410 | netlink_table_grab(); | |
d470e3b4 DM |
411 | if (sk_del_node_init(sk)) |
412 | nl_table[sk->sk_protocol].hash.entries--; | |
f7fa9b10 | 413 | if (nlk_sk(sk)->subscriptions) |
1da177e4 LT |
414 | __sk_del_bind_node(sk); |
415 | netlink_table_ungrab(); | |
416 | } | |
417 | ||
418 | static struct proto netlink_proto = { | |
419 | .name = "NETLINK", | |
420 | .owner = THIS_MODULE, | |
421 | .obj_size = sizeof(struct netlink_sock), | |
422 | }; | |
423 | ||
1b8d7ae4 EB |
424 | static int __netlink_create(struct net *net, struct socket *sock, |
425 | struct mutex *cb_mutex, int protocol) | |
1da177e4 LT |
426 | { |
427 | struct sock *sk; | |
428 | struct netlink_sock *nlk; | |
ab33a171 PM |
429 | |
430 | sock->ops = &netlink_ops; | |
431 | ||
6257ff21 | 432 | sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto); |
ab33a171 PM |
433 | if (!sk) |
434 | return -ENOMEM; | |
435 | ||
436 | sock_init_data(sock, sk); | |
437 | ||
438 | nlk = nlk_sk(sk); | |
658cb354 | 439 | if (cb_mutex) { |
ffa4d721 | 440 | nlk->cb_mutex = cb_mutex; |
658cb354 | 441 | } else { |
ffa4d721 PM |
442 | nlk->cb_mutex = &nlk->cb_def_mutex; |
443 | mutex_init(nlk->cb_mutex); | |
444 | } | |
ab33a171 PM |
445 | init_waitqueue_head(&nlk->wait); |
446 | ||
447 | sk->sk_destruct = netlink_sock_destruct; | |
448 | sk->sk_protocol = protocol; | |
449 | return 0; | |
450 | } | |
451 | ||
3f378b68 EP |
452 | static int netlink_create(struct net *net, struct socket *sock, int protocol, |
453 | int kern) | |
ab33a171 PM |
454 | { |
455 | struct module *module = NULL; | |
af65bdfc | 456 | struct mutex *cb_mutex; |
f7fa9b10 | 457 | struct netlink_sock *nlk; |
03292745 | 458 | void (*bind)(int group); |
ab33a171 | 459 | int err = 0; |
1da177e4 LT |
460 | |
461 | sock->state = SS_UNCONNECTED; | |
462 | ||
463 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
464 | return -ESOCKTNOSUPPORT; | |
465 | ||
6ac552fd | 466 | if (protocol < 0 || protocol >= MAX_LINKS) |
1da177e4 LT |
467 | return -EPROTONOSUPPORT; |
468 | ||
77247bbb | 469 | netlink_lock_table(); |
95a5afca | 470 | #ifdef CONFIG_MODULES |
ab33a171 | 471 | if (!nl_table[protocol].registered) { |
77247bbb | 472 | netlink_unlock_table(); |
4fdb3bb7 | 473 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 474 | netlink_lock_table(); |
4fdb3bb7 | 475 | } |
ab33a171 PM |
476 | #endif |
477 | if (nl_table[protocol].registered && | |
478 | try_module_get(nl_table[protocol].module)) | |
479 | module = nl_table[protocol].module; | |
974c37e9 AD |
480 | else |
481 | err = -EPROTONOSUPPORT; | |
af65bdfc | 482 | cb_mutex = nl_table[protocol].cb_mutex; |
03292745 | 483 | bind = nl_table[protocol].bind; |
77247bbb | 484 | netlink_unlock_table(); |
4fdb3bb7 | 485 | |
974c37e9 AD |
486 | if (err < 0) |
487 | goto out; | |
488 | ||
6ac552fd PM |
489 | err = __netlink_create(net, sock, cb_mutex, protocol); |
490 | if (err < 0) | |
f7fa9b10 PM |
491 | goto out_module; |
492 | ||
6f756a8c | 493 | local_bh_disable(); |
c1fd3b94 | 494 | sock_prot_inuse_add(net, &netlink_proto, 1); |
6f756a8c DM |
495 | local_bh_enable(); |
496 | ||
f7fa9b10 | 497 | nlk = nlk_sk(sock->sk); |
f7fa9b10 | 498 | nlk->module = module; |
03292745 | 499 | nlk->netlink_bind = bind; |
ab33a171 PM |
500 | out: |
501 | return err; | |
1da177e4 | 502 | |
ab33a171 PM |
503 | out_module: |
504 | module_put(module); | |
505 | goto out; | |
1da177e4 LT |
506 | } |
507 | ||
508 | static int netlink_release(struct socket *sock) | |
509 | { | |
510 | struct sock *sk = sock->sk; | |
511 | struct netlink_sock *nlk; | |
512 | ||
513 | if (!sk) | |
514 | return 0; | |
515 | ||
516 | netlink_remove(sk); | |
ac57b3a9 | 517 | sock_orphan(sk); |
1da177e4 LT |
518 | nlk = nlk_sk(sk); |
519 | ||
3f660d66 HX |
520 | /* |
521 | * OK. Socket is unlinked, any packets that arrive now | |
522 | * will be purged. | |
523 | */ | |
1da177e4 | 524 | |
1da177e4 LT |
525 | sock->sk = NULL; |
526 | wake_up_interruptible_all(&nlk->wait); | |
527 | ||
528 | skb_queue_purge(&sk->sk_write_queue); | |
529 | ||
15e47304 | 530 | if (nlk->portid) { |
1da177e4 | 531 | struct netlink_notify n = { |
3b1e0a65 | 532 | .net = sock_net(sk), |
1da177e4 | 533 | .protocol = sk->sk_protocol, |
15e47304 | 534 | .portid = nlk->portid, |
1da177e4 | 535 | }; |
e041c683 AS |
536 | atomic_notifier_call_chain(&netlink_chain, |
537 | NETLINK_URELEASE, &n); | |
746fac4d | 538 | } |
4fdb3bb7 | 539 | |
5e7c001c | 540 | module_put(nlk->module); |
4fdb3bb7 | 541 | |
4277a083 | 542 | netlink_table_grab(); |
aed81560 | 543 | if (netlink_is_kernel(sk)) { |
869e58f8 DL |
544 | BUG_ON(nl_table[sk->sk_protocol].registered == 0); |
545 | if (--nl_table[sk->sk_protocol].registered == 0) { | |
6d772ac5 ED |
546 | struct listeners *old; |
547 | ||
548 | old = nl_deref_protected(nl_table[sk->sk_protocol].listeners); | |
549 | RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL); | |
550 | kfree_rcu(old, rcu); | |
869e58f8 | 551 | nl_table[sk->sk_protocol].module = NULL; |
9785e10a PNA |
552 | nl_table[sk->sk_protocol].bind = NULL; |
553 | nl_table[sk->sk_protocol].flags = 0; | |
869e58f8 DL |
554 | nl_table[sk->sk_protocol].registered = 0; |
555 | } | |
658cb354 | 556 | } else if (nlk->subscriptions) { |
4277a083 | 557 | netlink_update_listeners(sk); |
658cb354 | 558 | } |
4277a083 | 559 | netlink_table_ungrab(); |
77247bbb | 560 | |
f7fa9b10 PM |
561 | kfree(nlk->groups); |
562 | nlk->groups = NULL; | |
563 | ||
3755810c | 564 | local_bh_disable(); |
c1fd3b94 | 565 | sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); |
3755810c | 566 | local_bh_enable(); |
1da177e4 LT |
567 | sock_put(sk); |
568 | return 0; | |
569 | } | |
570 | ||
571 | static int netlink_autobind(struct socket *sock) | |
572 | { | |
573 | struct sock *sk = sock->sk; | |
3b1e0a65 | 574 | struct net *net = sock_net(sk); |
15e47304 | 575 | struct nl_portid_hash *hash = &nl_table[sk->sk_protocol].hash; |
1da177e4 LT |
576 | struct hlist_head *head; |
577 | struct sock *osk; | |
578 | struct hlist_node *node; | |
15e47304 | 579 | s32 portid = task_tgid_vnr(current); |
1da177e4 LT |
580 | int err; |
581 | static s32 rover = -4097; | |
582 | ||
583 | retry: | |
584 | cond_resched(); | |
585 | netlink_table_grab(); | |
15e47304 | 586 | head = nl_portid_hashfn(hash, portid); |
1da177e4 | 587 | sk_for_each(osk, node, head) { |
878628fb | 588 | if (!net_eq(sock_net(osk), net)) |
b4b51029 | 589 | continue; |
15e47304 EB |
590 | if (nlk_sk(osk)->portid == portid) { |
591 | /* Bind collision, search negative portid values. */ | |
592 | portid = rover--; | |
1da177e4 LT |
593 | if (rover > -4097) |
594 | rover = -4097; | |
595 | netlink_table_ungrab(); | |
596 | goto retry; | |
597 | } | |
598 | } | |
599 | netlink_table_ungrab(); | |
600 | ||
15e47304 | 601 | err = netlink_insert(sk, net, portid); |
1da177e4 LT |
602 | if (err == -EADDRINUSE) |
603 | goto retry; | |
d470e3b4 DM |
604 | |
605 | /* If 2 threads race to autobind, that is fine. */ | |
606 | if (err == -EBUSY) | |
607 | err = 0; | |
608 | ||
609 | return err; | |
1da177e4 LT |
610 | } |
611 | ||
b57ef81f | 612 | static inline int netlink_capable(const struct socket *sock, unsigned int flag) |
746fac4d | 613 | { |
9785e10a | 614 | return (nl_table[sock->sk->sk_protocol].flags & flag) || |
df008c91 | 615 | ns_capable(sock_net(sock->sk)->user_ns, CAP_NET_ADMIN); |
746fac4d | 616 | } |
1da177e4 | 617 | |
f7fa9b10 PM |
618 | static void |
619 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
620 | { | |
621 | struct netlink_sock *nlk = nlk_sk(sk); | |
622 | ||
623 | if (nlk->subscriptions && !subscriptions) | |
624 | __sk_del_bind_node(sk); | |
625 | else if (!nlk->subscriptions && subscriptions) | |
626 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
627 | nlk->subscriptions = subscriptions; | |
628 | } | |
629 | ||
b4ff4f04 | 630 | static int netlink_realloc_groups(struct sock *sk) |
513c2500 PM |
631 | { |
632 | struct netlink_sock *nlk = nlk_sk(sk); | |
633 | unsigned int groups; | |
b4ff4f04 | 634 | unsigned long *new_groups; |
513c2500 PM |
635 | int err = 0; |
636 | ||
b4ff4f04 JB |
637 | netlink_table_grab(); |
638 | ||
513c2500 | 639 | groups = nl_table[sk->sk_protocol].groups; |
b4ff4f04 | 640 | if (!nl_table[sk->sk_protocol].registered) { |
513c2500 | 641 | err = -ENOENT; |
b4ff4f04 JB |
642 | goto out_unlock; |
643 | } | |
513c2500 | 644 | |
b4ff4f04 JB |
645 | if (nlk->ngroups >= groups) |
646 | goto out_unlock; | |
513c2500 | 647 | |
b4ff4f04 JB |
648 | new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
649 | if (new_groups == NULL) { | |
650 | err = -ENOMEM; | |
651 | goto out_unlock; | |
652 | } | |
6ac552fd | 653 | memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, |
b4ff4f04 JB |
654 | NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); |
655 | ||
656 | nlk->groups = new_groups; | |
513c2500 | 657 | nlk->ngroups = groups; |
b4ff4f04 JB |
658 | out_unlock: |
659 | netlink_table_ungrab(); | |
660 | return err; | |
513c2500 PM |
661 | } |
662 | ||
6ac552fd PM |
663 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, |
664 | int addr_len) | |
1da177e4 LT |
665 | { |
666 | struct sock *sk = sock->sk; | |
3b1e0a65 | 667 | struct net *net = sock_net(sk); |
1da177e4 LT |
668 | struct netlink_sock *nlk = nlk_sk(sk); |
669 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
670 | int err; | |
746fac4d | 671 | |
4e4b5376 HFS |
672 | if (addr_len < sizeof(struct sockaddr_nl)) |
673 | return -EINVAL; | |
674 | ||
1da177e4 LT |
675 | if (nladdr->nl_family != AF_NETLINK) |
676 | return -EINVAL; | |
677 | ||
678 | /* Only superuser is allowed to listen multicasts */ | |
513c2500 | 679 | if (nladdr->nl_groups) { |
9785e10a | 680 | if (!netlink_capable(sock, NL_CFG_F_NONROOT_RECV)) |
513c2500 | 681 | return -EPERM; |
b4ff4f04 JB |
682 | err = netlink_realloc_groups(sk); |
683 | if (err) | |
684 | return err; | |
513c2500 | 685 | } |
1da177e4 | 686 | |
15e47304 EB |
687 | if (nlk->portid) { |
688 | if (nladdr->nl_pid != nlk->portid) | |
1da177e4 LT |
689 | return -EINVAL; |
690 | } else { | |
691 | err = nladdr->nl_pid ? | |
b4b51029 | 692 | netlink_insert(sk, net, nladdr->nl_pid) : |
1da177e4 LT |
693 | netlink_autobind(sock); |
694 | if (err) | |
695 | return err; | |
696 | } | |
697 | ||
513c2500 | 698 | if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
1da177e4 LT |
699 | return 0; |
700 | ||
701 | netlink_table_grab(); | |
f7fa9b10 | 702 | netlink_update_subscriptions(sk, nlk->subscriptions + |
746fac4d YH |
703 | hweight32(nladdr->nl_groups) - |
704 | hweight32(nlk->groups[0])); | |
705 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups; | |
4277a083 | 706 | netlink_update_listeners(sk); |
1da177e4 LT |
707 | netlink_table_ungrab(); |
708 | ||
03292745 PNA |
709 | if (nlk->netlink_bind && nlk->groups[0]) { |
710 | int i; | |
711 | ||
712 | for (i=0; i<nlk->ngroups; i++) { | |
713 | if (test_bit(i, nlk->groups)) | |
714 | nlk->netlink_bind(i); | |
715 | } | |
716 | } | |
717 | ||
1da177e4 LT |
718 | return 0; |
719 | } | |
720 | ||
721 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
722 | int alen, int flags) | |
723 | { | |
724 | int err = 0; | |
725 | struct sock *sk = sock->sk; | |
726 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 727 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
1da177e4 | 728 | |
6503d961 CG |
729 | if (alen < sizeof(addr->sa_family)) |
730 | return -EINVAL; | |
731 | ||
1da177e4 LT |
732 | if (addr->sa_family == AF_UNSPEC) { |
733 | sk->sk_state = NETLINK_UNCONNECTED; | |
15e47304 | 734 | nlk->dst_portid = 0; |
d629b836 | 735 | nlk->dst_group = 0; |
1da177e4 LT |
736 | return 0; |
737 | } | |
738 | if (addr->sa_family != AF_NETLINK) | |
739 | return -EINVAL; | |
740 | ||
741 | /* Only superuser is allowed to send multicasts */ | |
9785e10a | 742 | if (nladdr->nl_groups && !netlink_capable(sock, NL_CFG_F_NONROOT_SEND)) |
1da177e4 LT |
743 | return -EPERM; |
744 | ||
15e47304 | 745 | if (!nlk->portid) |
1da177e4 LT |
746 | err = netlink_autobind(sock); |
747 | ||
748 | if (err == 0) { | |
749 | sk->sk_state = NETLINK_CONNECTED; | |
15e47304 | 750 | nlk->dst_portid = nladdr->nl_pid; |
d629b836 | 751 | nlk->dst_group = ffs(nladdr->nl_groups); |
1da177e4 LT |
752 | } |
753 | ||
754 | return err; | |
755 | } | |
756 | ||
6ac552fd PM |
757 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, |
758 | int *addr_len, int peer) | |
1da177e4 LT |
759 | { |
760 | struct sock *sk = sock->sk; | |
761 | struct netlink_sock *nlk = nlk_sk(sk); | |
13cfa97b | 762 | DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr); |
746fac4d | 763 | |
1da177e4 LT |
764 | nladdr->nl_family = AF_NETLINK; |
765 | nladdr->nl_pad = 0; | |
766 | *addr_len = sizeof(*nladdr); | |
767 | ||
768 | if (peer) { | |
15e47304 | 769 | nladdr->nl_pid = nlk->dst_portid; |
d629b836 | 770 | nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
1da177e4 | 771 | } else { |
15e47304 | 772 | nladdr->nl_pid = nlk->portid; |
513c2500 | 773 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
1da177e4 LT |
774 | } |
775 | return 0; | |
776 | } | |
777 | ||
778 | static void netlink_overrun(struct sock *sk) | |
779 | { | |
38938bfe PNA |
780 | struct netlink_sock *nlk = nlk_sk(sk); |
781 | ||
782 | if (!(nlk->flags & NETLINK_RECV_NO_ENOBUFS)) { | |
783 | if (!test_and_set_bit(0, &nlk_sk(sk)->state)) { | |
784 | sk->sk_err = ENOBUFS; | |
785 | sk->sk_error_report(sk); | |
786 | } | |
1da177e4 | 787 | } |
38938bfe | 788 | atomic_inc(&sk->sk_drops); |
1da177e4 LT |
789 | } |
790 | ||
15e47304 | 791 | static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid) |
1da177e4 | 792 | { |
1da177e4 LT |
793 | struct sock *sock; |
794 | struct netlink_sock *nlk; | |
795 | ||
15e47304 | 796 | sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, portid); |
1da177e4 LT |
797 | if (!sock) |
798 | return ERR_PTR(-ECONNREFUSED); | |
799 | ||
800 | /* Don't bother queuing skb if kernel socket has no input function */ | |
801 | nlk = nlk_sk(sock); | |
cd40b7d3 | 802 | if (sock->sk_state == NETLINK_CONNECTED && |
15e47304 | 803 | nlk->dst_portid != nlk_sk(ssk)->portid) { |
1da177e4 LT |
804 | sock_put(sock); |
805 | return ERR_PTR(-ECONNREFUSED); | |
806 | } | |
807 | return sock; | |
808 | } | |
809 | ||
810 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
811 | { | |
6db5fc5d | 812 | struct inode *inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
813 | struct sock *sock; |
814 | ||
815 | if (!S_ISSOCK(inode->i_mode)) | |
816 | return ERR_PTR(-ENOTSOCK); | |
817 | ||
818 | sock = SOCKET_I(inode)->sk; | |
819 | if (sock->sk_family != AF_NETLINK) | |
820 | return ERR_PTR(-EINVAL); | |
821 | ||
822 | sock_hold(sock); | |
823 | return sock; | |
824 | } | |
825 | ||
826 | /* | |
827 | * Attach a skb to a netlink socket. | |
828 | * The caller must hold a reference to the destination socket. On error, the | |
829 | * reference is dropped. The skb is not send to the destination, just all | |
830 | * all error checks are performed and memory in the queue is reserved. | |
831 | * Return values: | |
832 | * < 0: error. skb freed, reference to sock dropped. | |
833 | * 0: continue | |
834 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
835 | */ | |
9457afee | 836 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
c3d8d1e3 | 837 | long *timeo, struct sock *ssk) |
1da177e4 LT |
838 | { |
839 | struct netlink_sock *nlk; | |
840 | ||
841 | nlk = nlk_sk(sk); | |
842 | ||
843 | if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
844 | test_bit(0, &nlk->state)) { | |
845 | DECLARE_WAITQUEUE(wait, current); | |
c3d8d1e3 | 846 | if (!*timeo) { |
aed81560 | 847 | if (!ssk || netlink_is_kernel(ssk)) |
1da177e4 LT |
848 | netlink_overrun(sk); |
849 | sock_put(sk); | |
850 | kfree_skb(skb); | |
851 | return -EAGAIN; | |
852 | } | |
853 | ||
854 | __set_current_state(TASK_INTERRUPTIBLE); | |
855 | add_wait_queue(&nlk->wait, &wait); | |
856 | ||
857 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
858 | test_bit(0, &nlk->state)) && | |
859 | !sock_flag(sk, SOCK_DEAD)) | |
c3d8d1e3 | 860 | *timeo = schedule_timeout(*timeo); |
1da177e4 LT |
861 | |
862 | __set_current_state(TASK_RUNNING); | |
863 | remove_wait_queue(&nlk->wait, &wait); | |
864 | sock_put(sk); | |
865 | ||
866 | if (signal_pending(current)) { | |
867 | kfree_skb(skb); | |
c3d8d1e3 | 868 | return sock_intr_errno(*timeo); |
1da177e4 LT |
869 | } |
870 | return 1; | |
871 | } | |
872 | skb_set_owner_r(skb, sk); | |
873 | return 0; | |
874 | } | |
875 | ||
4a7e7c2a | 876 | static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 877 | { |
1da177e4 LT |
878 | int len = skb->len; |
879 | ||
1da177e4 LT |
880 | skb_queue_tail(&sk->sk_receive_queue, skb); |
881 | sk->sk_data_ready(sk, len); | |
4a7e7c2a ED |
882 | return len; |
883 | } | |
884 | ||
885 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb) | |
886 | { | |
887 | int len = __netlink_sendskb(sk, skb); | |
888 | ||
1da177e4 LT |
889 | sock_put(sk); |
890 | return len; | |
891 | } | |
892 | ||
893 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
894 | { | |
895 | kfree_skb(skb); | |
896 | sock_put(sk); | |
897 | } | |
898 | ||
b57ef81f | 899 | static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation) |
1da177e4 LT |
900 | { |
901 | int delta; | |
902 | ||
903 | skb_orphan(skb); | |
904 | ||
4305b541 | 905 | delta = skb->end - skb->tail; |
1da177e4 LT |
906 | if (delta * 2 < skb->truesize) |
907 | return skb; | |
908 | ||
909 | if (skb_shared(skb)) { | |
910 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
911 | if (!nskb) | |
912 | return skb; | |
8460c00f | 913 | consume_skb(skb); |
1da177e4 LT |
914 | skb = nskb; |
915 | } | |
916 | ||
917 | if (!pskb_expand_head(skb, 0, -delta, allocation)) | |
918 | skb->truesize -= delta; | |
919 | ||
920 | return skb; | |
921 | } | |
922 | ||
b57ef81f | 923 | static void netlink_rcv_wake(struct sock *sk) |
cd40b7d3 DL |
924 | { |
925 | struct netlink_sock *nlk = nlk_sk(sk); | |
926 | ||
927 | if (skb_queue_empty(&sk->sk_receive_queue)) | |
928 | clear_bit(0, &nlk->state); | |
929 | if (!test_bit(0, &nlk->state)) | |
930 | wake_up_interruptible(&nlk->wait); | |
931 | } | |
932 | ||
3fbc2905 EB |
933 | static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb, |
934 | struct sock *ssk) | |
cd40b7d3 DL |
935 | { |
936 | int ret; | |
937 | struct netlink_sock *nlk = nlk_sk(sk); | |
938 | ||
939 | ret = -ECONNREFUSED; | |
940 | if (nlk->netlink_rcv != NULL) { | |
941 | ret = skb->len; | |
942 | skb_set_owner_r(skb, sk); | |
3fbc2905 | 943 | NETLINK_CB(skb).ssk = ssk; |
cd40b7d3 | 944 | nlk->netlink_rcv(skb); |
bfb253c9 ED |
945 | consume_skb(skb); |
946 | } else { | |
947 | kfree_skb(skb); | |
cd40b7d3 | 948 | } |
cd40b7d3 DL |
949 | sock_put(sk); |
950 | return ret; | |
951 | } | |
952 | ||
953 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, | |
15e47304 | 954 | u32 portid, int nonblock) |
1da177e4 LT |
955 | { |
956 | struct sock *sk; | |
957 | int err; | |
958 | long timeo; | |
959 | ||
960 | skb = netlink_trim(skb, gfp_any()); | |
961 | ||
962 | timeo = sock_sndtimeo(ssk, nonblock); | |
963 | retry: | |
15e47304 | 964 | sk = netlink_getsockbyportid(ssk, portid); |
1da177e4 LT |
965 | if (IS_ERR(sk)) { |
966 | kfree_skb(skb); | |
967 | return PTR_ERR(sk); | |
968 | } | |
cd40b7d3 | 969 | if (netlink_is_kernel(sk)) |
3fbc2905 | 970 | return netlink_unicast_kernel(sk, skb, ssk); |
cd40b7d3 | 971 | |
b1153f29 | 972 | if (sk_filter(sk, skb)) { |
84874607 | 973 | err = skb->len; |
b1153f29 SH |
974 | kfree_skb(skb); |
975 | sock_put(sk); | |
976 | return err; | |
977 | } | |
978 | ||
9457afee | 979 | err = netlink_attachskb(sk, skb, &timeo, ssk); |
1da177e4 LT |
980 | if (err == 1) |
981 | goto retry; | |
982 | if (err) | |
983 | return err; | |
984 | ||
7ee015e0 | 985 | return netlink_sendskb(sk, skb); |
1da177e4 | 986 | } |
6ac552fd | 987 | EXPORT_SYMBOL(netlink_unicast); |
1da177e4 | 988 | |
4277a083 PM |
989 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
990 | { | |
991 | int res = 0; | |
5c398dc8 | 992 | struct listeners *listeners; |
4277a083 | 993 | |
aed81560 | 994 | BUG_ON(!netlink_is_kernel(sk)); |
b4ff4f04 JB |
995 | |
996 | rcu_read_lock(); | |
997 | listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); | |
998 | ||
6d772ac5 | 999 | if (listeners && group - 1 < nl_table[sk->sk_protocol].groups) |
5c398dc8 | 1000 | res = test_bit(group - 1, listeners->masks); |
b4ff4f04 JB |
1001 | |
1002 | rcu_read_unlock(); | |
1003 | ||
4277a083 PM |
1004 | return res; |
1005 | } | |
1006 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
1007 | ||
b57ef81f | 1008 | static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) |
1da177e4 LT |
1009 | { |
1010 | struct netlink_sock *nlk = nlk_sk(sk); | |
1011 | ||
1012 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
1013 | !test_bit(0, &nlk->state)) { | |
1014 | skb_set_owner_r(skb, sk); | |
4a7e7c2a | 1015 | __netlink_sendskb(sk, skb); |
2c645800 | 1016 | return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1); |
1da177e4 LT |
1017 | } |
1018 | return -1; | |
1019 | } | |
1020 | ||
1021 | struct netlink_broadcast_data { | |
1022 | struct sock *exclude_sk; | |
b4b51029 | 1023 | struct net *net; |
15e47304 | 1024 | u32 portid; |
1da177e4 LT |
1025 | u32 group; |
1026 | int failure; | |
ff491a73 | 1027 | int delivery_failure; |
1da177e4 LT |
1028 | int congested; |
1029 | int delivered; | |
7d877f3b | 1030 | gfp_t allocation; |
1da177e4 | 1031 | struct sk_buff *skb, *skb2; |
910a7e90 EB |
1032 | int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data); |
1033 | void *tx_data; | |
1da177e4 LT |
1034 | }; |
1035 | ||
b57ef81f | 1036 | static int do_one_broadcast(struct sock *sk, |
1da177e4 LT |
1037 | struct netlink_broadcast_data *p) |
1038 | { | |
1039 | struct netlink_sock *nlk = nlk_sk(sk); | |
1040 | int val; | |
1041 | ||
1042 | if (p->exclude_sk == sk) | |
1043 | goto out; | |
1044 | ||
15e47304 | 1045 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
f7fa9b10 | 1046 | !test_bit(p->group - 1, nlk->groups)) |
1da177e4 LT |
1047 | goto out; |
1048 | ||
878628fb | 1049 | if (!net_eq(sock_net(sk), p->net)) |
b4b51029 EB |
1050 | goto out; |
1051 | ||
1da177e4 LT |
1052 | if (p->failure) { |
1053 | netlink_overrun(sk); | |
1054 | goto out; | |
1055 | } | |
1056 | ||
1057 | sock_hold(sk); | |
1058 | if (p->skb2 == NULL) { | |
68acc024 | 1059 | if (skb_shared(p->skb)) { |
1da177e4 LT |
1060 | p->skb2 = skb_clone(p->skb, p->allocation); |
1061 | } else { | |
68acc024 TC |
1062 | p->skb2 = skb_get(p->skb); |
1063 | /* | |
1064 | * skb ownership may have been set when | |
1065 | * delivered to a previous socket. | |
1066 | */ | |
1067 | skb_orphan(p->skb2); | |
1da177e4 LT |
1068 | } |
1069 | } | |
1070 | if (p->skb2 == NULL) { | |
1071 | netlink_overrun(sk); | |
1072 | /* Clone failed. Notify ALL listeners. */ | |
1073 | p->failure = 1; | |
be0c22a4 PNA |
1074 | if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) |
1075 | p->delivery_failure = 1; | |
910a7e90 EB |
1076 | } else if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) { |
1077 | kfree_skb(p->skb2); | |
1078 | p->skb2 = NULL; | |
b1153f29 SH |
1079 | } else if (sk_filter(sk, p->skb2)) { |
1080 | kfree_skb(p->skb2); | |
1081 | p->skb2 = NULL; | |
1da177e4 LT |
1082 | } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) { |
1083 | netlink_overrun(sk); | |
be0c22a4 PNA |
1084 | if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) |
1085 | p->delivery_failure = 1; | |
1da177e4 LT |
1086 | } else { |
1087 | p->congested |= val; | |
1088 | p->delivered = 1; | |
1089 | p->skb2 = NULL; | |
1090 | } | |
1091 | sock_put(sk); | |
1092 | ||
1093 | out: | |
1094 | return 0; | |
1095 | } | |
1096 | ||
15e47304 | 1097 | int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 portid, |
910a7e90 EB |
1098 | u32 group, gfp_t allocation, |
1099 | int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data), | |
1100 | void *filter_data) | |
1da177e4 | 1101 | { |
3b1e0a65 | 1102 | struct net *net = sock_net(ssk); |
1da177e4 LT |
1103 | struct netlink_broadcast_data info; |
1104 | struct hlist_node *node; | |
1105 | struct sock *sk; | |
1106 | ||
1107 | skb = netlink_trim(skb, allocation); | |
1108 | ||
1109 | info.exclude_sk = ssk; | |
b4b51029 | 1110 | info.net = net; |
15e47304 | 1111 | info.portid = portid; |
1da177e4 LT |
1112 | info.group = group; |
1113 | info.failure = 0; | |
ff491a73 | 1114 | info.delivery_failure = 0; |
1da177e4 LT |
1115 | info.congested = 0; |
1116 | info.delivered = 0; | |
1117 | info.allocation = allocation; | |
1118 | info.skb = skb; | |
1119 | info.skb2 = NULL; | |
910a7e90 EB |
1120 | info.tx_filter = filter; |
1121 | info.tx_data = filter_data; | |
1da177e4 LT |
1122 | |
1123 | /* While we sleep in clone, do not allow to change socket list */ | |
1124 | ||
1125 | netlink_lock_table(); | |
1126 | ||
1127 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1128 | do_one_broadcast(sk, &info); | |
1129 | ||
70d4bf6d | 1130 | consume_skb(skb); |
aa1c6a6f | 1131 | |
1da177e4 LT |
1132 | netlink_unlock_table(); |
1133 | ||
70d4bf6d NH |
1134 | if (info.delivery_failure) { |
1135 | kfree_skb(info.skb2); | |
ff491a73 | 1136 | return -ENOBUFS; |
658cb354 ED |
1137 | } |
1138 | consume_skb(info.skb2); | |
ff491a73 | 1139 | |
1da177e4 LT |
1140 | if (info.delivered) { |
1141 | if (info.congested && (allocation & __GFP_WAIT)) | |
1142 | yield(); | |
1143 | return 0; | |
1144 | } | |
1da177e4 LT |
1145 | return -ESRCH; |
1146 | } | |
910a7e90 EB |
1147 | EXPORT_SYMBOL(netlink_broadcast_filtered); |
1148 | ||
15e47304 | 1149 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 portid, |
910a7e90 EB |
1150 | u32 group, gfp_t allocation) |
1151 | { | |
15e47304 | 1152 | return netlink_broadcast_filtered(ssk, skb, portid, group, allocation, |
910a7e90 EB |
1153 | NULL, NULL); |
1154 | } | |
6ac552fd | 1155 | EXPORT_SYMBOL(netlink_broadcast); |
1da177e4 LT |
1156 | |
1157 | struct netlink_set_err_data { | |
1158 | struct sock *exclude_sk; | |
15e47304 | 1159 | u32 portid; |
1da177e4 LT |
1160 | u32 group; |
1161 | int code; | |
1162 | }; | |
1163 | ||
b57ef81f | 1164 | static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p) |
1da177e4 LT |
1165 | { |
1166 | struct netlink_sock *nlk = nlk_sk(sk); | |
1a50307b | 1167 | int ret = 0; |
1da177e4 LT |
1168 | |
1169 | if (sk == p->exclude_sk) | |
1170 | goto out; | |
1171 | ||
09ad9bc7 | 1172 | if (!net_eq(sock_net(sk), sock_net(p->exclude_sk))) |
b4b51029 EB |
1173 | goto out; |
1174 | ||
15e47304 | 1175 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
f7fa9b10 | 1176 | !test_bit(p->group - 1, nlk->groups)) |
1da177e4 LT |
1177 | goto out; |
1178 | ||
1a50307b PNA |
1179 | if (p->code == ENOBUFS && nlk->flags & NETLINK_RECV_NO_ENOBUFS) { |
1180 | ret = 1; | |
1181 | goto out; | |
1182 | } | |
1183 | ||
1da177e4 LT |
1184 | sk->sk_err = p->code; |
1185 | sk->sk_error_report(sk); | |
1186 | out: | |
1a50307b | 1187 | return ret; |
1da177e4 LT |
1188 | } |
1189 | ||
4843b93c PNA |
1190 | /** |
1191 | * netlink_set_err - report error to broadcast listeners | |
1192 | * @ssk: the kernel netlink socket, as returned by netlink_kernel_create() | |
15e47304 | 1193 | * @portid: the PORTID of a process that we want to skip (if any) |
4843b93c PNA |
1194 | * @groups: the broadcast group that will notice the error |
1195 | * @code: error code, must be negative (as usual in kernelspace) | |
1a50307b PNA |
1196 | * |
1197 | * This function returns the number of broadcast listeners that have set the | |
1198 | * NETLINK_RECV_NO_ENOBUFS socket option. | |
4843b93c | 1199 | */ |
15e47304 | 1200 | int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code) |
1da177e4 LT |
1201 | { |
1202 | struct netlink_set_err_data info; | |
1203 | struct hlist_node *node; | |
1204 | struct sock *sk; | |
1a50307b | 1205 | int ret = 0; |
1da177e4 LT |
1206 | |
1207 | info.exclude_sk = ssk; | |
15e47304 | 1208 | info.portid = portid; |
1da177e4 | 1209 | info.group = group; |
4843b93c PNA |
1210 | /* sk->sk_err wants a positive error value */ |
1211 | info.code = -code; | |
1da177e4 LT |
1212 | |
1213 | read_lock(&nl_table_lock); | |
1214 | ||
1215 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1a50307b | 1216 | ret += do_one_set_err(sk, &info); |
1da177e4 LT |
1217 | |
1218 | read_unlock(&nl_table_lock); | |
1a50307b | 1219 | return ret; |
1da177e4 | 1220 | } |
dd5b6ce6 | 1221 | EXPORT_SYMBOL(netlink_set_err); |
1da177e4 | 1222 | |
84659eb5 JB |
1223 | /* must be called with netlink table grabbed */ |
1224 | static void netlink_update_socket_mc(struct netlink_sock *nlk, | |
1225 | unsigned int group, | |
1226 | int is_new) | |
1227 | { | |
1228 | int old, new = !!is_new, subscriptions; | |
1229 | ||
1230 | old = test_bit(group - 1, nlk->groups); | |
1231 | subscriptions = nlk->subscriptions - old + new; | |
1232 | if (new) | |
1233 | __set_bit(group - 1, nlk->groups); | |
1234 | else | |
1235 | __clear_bit(group - 1, nlk->groups); | |
1236 | netlink_update_subscriptions(&nlk->sk, subscriptions); | |
1237 | netlink_update_listeners(&nlk->sk); | |
1238 | } | |
1239 | ||
9a4595bc | 1240 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
b7058842 | 1241 | char __user *optval, unsigned int optlen) |
9a4595bc PM |
1242 | { |
1243 | struct sock *sk = sock->sk; | |
1244 | struct netlink_sock *nlk = nlk_sk(sk); | |
eb496534 JB |
1245 | unsigned int val = 0; |
1246 | int err; | |
9a4595bc PM |
1247 | |
1248 | if (level != SOL_NETLINK) | |
1249 | return -ENOPROTOOPT; | |
1250 | ||
1251 | if (optlen >= sizeof(int) && | |
eb496534 | 1252 | get_user(val, (unsigned int __user *)optval)) |
9a4595bc PM |
1253 | return -EFAULT; |
1254 | ||
1255 | switch (optname) { | |
1256 | case NETLINK_PKTINFO: | |
1257 | if (val) | |
1258 | nlk->flags |= NETLINK_RECV_PKTINFO; | |
1259 | else | |
1260 | nlk->flags &= ~NETLINK_RECV_PKTINFO; | |
1261 | err = 0; | |
1262 | break; | |
1263 | case NETLINK_ADD_MEMBERSHIP: | |
1264 | case NETLINK_DROP_MEMBERSHIP: { | |
9785e10a | 1265 | if (!netlink_capable(sock, NL_CFG_F_NONROOT_RECV)) |
9a4595bc | 1266 | return -EPERM; |
b4ff4f04 JB |
1267 | err = netlink_realloc_groups(sk); |
1268 | if (err) | |
1269 | return err; | |
9a4595bc PM |
1270 | if (!val || val - 1 >= nlk->ngroups) |
1271 | return -EINVAL; | |
1272 | netlink_table_grab(); | |
84659eb5 JB |
1273 | netlink_update_socket_mc(nlk, val, |
1274 | optname == NETLINK_ADD_MEMBERSHIP); | |
9a4595bc | 1275 | netlink_table_ungrab(); |
03292745 PNA |
1276 | |
1277 | if (nlk->netlink_bind) | |
1278 | nlk->netlink_bind(val); | |
1279 | ||
9a4595bc PM |
1280 | err = 0; |
1281 | break; | |
1282 | } | |
be0c22a4 PNA |
1283 | case NETLINK_BROADCAST_ERROR: |
1284 | if (val) | |
1285 | nlk->flags |= NETLINK_BROADCAST_SEND_ERROR; | |
1286 | else | |
1287 | nlk->flags &= ~NETLINK_BROADCAST_SEND_ERROR; | |
1288 | err = 0; | |
1289 | break; | |
38938bfe PNA |
1290 | case NETLINK_NO_ENOBUFS: |
1291 | if (val) { | |
1292 | nlk->flags |= NETLINK_RECV_NO_ENOBUFS; | |
1293 | clear_bit(0, &nlk->state); | |
1294 | wake_up_interruptible(&nlk->wait); | |
658cb354 | 1295 | } else { |
38938bfe | 1296 | nlk->flags &= ~NETLINK_RECV_NO_ENOBUFS; |
658cb354 | 1297 | } |
38938bfe PNA |
1298 | err = 0; |
1299 | break; | |
9a4595bc PM |
1300 | default: |
1301 | err = -ENOPROTOOPT; | |
1302 | } | |
1303 | return err; | |
1304 | } | |
1305 | ||
1306 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
746fac4d | 1307 | char __user *optval, int __user *optlen) |
9a4595bc PM |
1308 | { |
1309 | struct sock *sk = sock->sk; | |
1310 | struct netlink_sock *nlk = nlk_sk(sk); | |
1311 | int len, val, err; | |
1312 | ||
1313 | if (level != SOL_NETLINK) | |
1314 | return -ENOPROTOOPT; | |
1315 | ||
1316 | if (get_user(len, optlen)) | |
1317 | return -EFAULT; | |
1318 | if (len < 0) | |
1319 | return -EINVAL; | |
1320 | ||
1321 | switch (optname) { | |
1322 | case NETLINK_PKTINFO: | |
1323 | if (len < sizeof(int)) | |
1324 | return -EINVAL; | |
1325 | len = sizeof(int); | |
1326 | val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0; | |
a27b58fe HC |
1327 | if (put_user(len, optlen) || |
1328 | put_user(val, optval)) | |
1329 | return -EFAULT; | |
9a4595bc PM |
1330 | err = 0; |
1331 | break; | |
be0c22a4 PNA |
1332 | case NETLINK_BROADCAST_ERROR: |
1333 | if (len < sizeof(int)) | |
1334 | return -EINVAL; | |
1335 | len = sizeof(int); | |
1336 | val = nlk->flags & NETLINK_BROADCAST_SEND_ERROR ? 1 : 0; | |
1337 | if (put_user(len, optlen) || | |
1338 | put_user(val, optval)) | |
1339 | return -EFAULT; | |
1340 | err = 0; | |
1341 | break; | |
38938bfe PNA |
1342 | case NETLINK_NO_ENOBUFS: |
1343 | if (len < sizeof(int)) | |
1344 | return -EINVAL; | |
1345 | len = sizeof(int); | |
1346 | val = nlk->flags & NETLINK_RECV_NO_ENOBUFS ? 1 : 0; | |
1347 | if (put_user(len, optlen) || | |
1348 | put_user(val, optval)) | |
1349 | return -EFAULT; | |
1350 | err = 0; | |
1351 | break; | |
9a4595bc PM |
1352 | default: |
1353 | err = -ENOPROTOOPT; | |
1354 | } | |
1355 | return err; | |
1356 | } | |
1357 | ||
1358 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
1359 | { | |
1360 | struct nl_pktinfo info; | |
1361 | ||
1362 | info.group = NETLINK_CB(skb).dst_group; | |
1363 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
1364 | } | |
1365 | ||
1da177e4 LT |
1366 | static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, |
1367 | struct msghdr *msg, size_t len) | |
1368 | { | |
1369 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1370 | struct sock *sk = sock->sk; | |
1371 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 1372 | struct sockaddr_nl *addr = msg->msg_name; |
15e47304 | 1373 | u32 dst_portid; |
d629b836 | 1374 | u32 dst_group; |
1da177e4 LT |
1375 | struct sk_buff *skb; |
1376 | int err; | |
1377 | struct scm_cookie scm; | |
1378 | ||
1379 | if (msg->msg_flags&MSG_OOB) | |
1380 | return -EOPNOTSUPP; | |
1381 | ||
16e57262 | 1382 | if (NULL == siocb->scm) |
1da177e4 | 1383 | siocb->scm = &scm; |
16e57262 | 1384 | |
e0e3cea4 | 1385 | err = scm_send(sock, msg, siocb->scm, true); |
1da177e4 LT |
1386 | if (err < 0) |
1387 | return err; | |
1388 | ||
1389 | if (msg->msg_namelen) { | |
b47030c7 | 1390 | err = -EINVAL; |
1da177e4 | 1391 | if (addr->nl_family != AF_NETLINK) |
b47030c7 | 1392 | goto out; |
15e47304 | 1393 | dst_portid = addr->nl_pid; |
d629b836 | 1394 | dst_group = ffs(addr->nl_groups); |
b47030c7 | 1395 | err = -EPERM; |
15e47304 | 1396 | if ((dst_group || dst_portid) && |
9785e10a | 1397 | !netlink_capable(sock, NL_CFG_F_NONROOT_SEND)) |
b47030c7 | 1398 | goto out; |
1da177e4 | 1399 | } else { |
15e47304 | 1400 | dst_portid = nlk->dst_portid; |
d629b836 | 1401 | dst_group = nlk->dst_group; |
1da177e4 LT |
1402 | } |
1403 | ||
15e47304 | 1404 | if (!nlk->portid) { |
1da177e4 LT |
1405 | err = netlink_autobind(sock); |
1406 | if (err) | |
1407 | goto out; | |
1408 | } | |
1409 | ||
1410 | err = -EMSGSIZE; | |
1411 | if (len > sk->sk_sndbuf - 32) | |
1412 | goto out; | |
1413 | err = -ENOBUFS; | |
339bf98f | 1414 | skb = alloc_skb(len, GFP_KERNEL); |
6ac552fd | 1415 | if (skb == NULL) |
1da177e4 LT |
1416 | goto out; |
1417 | ||
15e47304 | 1418 | NETLINK_CB(skb).portid = nlk->portid; |
d629b836 | 1419 | NETLINK_CB(skb).dst_group = dst_group; |
dbe9a417 | 1420 | NETLINK_CB(skb).creds = siocb->scm->creds; |
1da177e4 | 1421 | |
1da177e4 | 1422 | err = -EFAULT; |
6ac552fd | 1423 | if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) { |
1da177e4 LT |
1424 | kfree_skb(skb); |
1425 | goto out; | |
1426 | } | |
1427 | ||
1428 | err = security_netlink_send(sk, skb); | |
1429 | if (err) { | |
1430 | kfree_skb(skb); | |
1431 | goto out; | |
1432 | } | |
1433 | ||
d629b836 | 1434 | if (dst_group) { |
1da177e4 | 1435 | atomic_inc(&skb->users); |
15e47304 | 1436 | netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL); |
1da177e4 | 1437 | } |
15e47304 | 1438 | err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags&MSG_DONTWAIT); |
1da177e4 LT |
1439 | |
1440 | out: | |
b47030c7 | 1441 | scm_destroy(siocb->scm); |
1da177e4 LT |
1442 | return err; |
1443 | } | |
1444 | ||
1445 | static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, | |
1446 | struct msghdr *msg, size_t len, | |
1447 | int flags) | |
1448 | { | |
1449 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1450 | struct scm_cookie scm; | |
1451 | struct sock *sk = sock->sk; | |
1452 | struct netlink_sock *nlk = nlk_sk(sk); | |
1453 | int noblock = flags&MSG_DONTWAIT; | |
1454 | size_t copied; | |
68d6ac6d | 1455 | struct sk_buff *skb, *data_skb; |
b44d211e | 1456 | int err, ret; |
1da177e4 LT |
1457 | |
1458 | if (flags&MSG_OOB) | |
1459 | return -EOPNOTSUPP; | |
1460 | ||
1461 | copied = 0; | |
1462 | ||
6ac552fd PM |
1463 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
1464 | if (skb == NULL) | |
1da177e4 LT |
1465 | goto out; |
1466 | ||
68d6ac6d JB |
1467 | data_skb = skb; |
1468 | ||
1dacc76d JB |
1469 | #ifdef CONFIG_COMPAT_NETLINK_MESSAGES |
1470 | if (unlikely(skb_shinfo(skb)->frag_list)) { | |
1dacc76d | 1471 | /* |
68d6ac6d JB |
1472 | * If this skb has a frag_list, then here that means that we |
1473 | * will have to use the frag_list skb's data for compat tasks | |
1474 | * and the regular skb's data for normal (non-compat) tasks. | |
1dacc76d | 1475 | * |
68d6ac6d JB |
1476 | * If we need to send the compat skb, assign it to the |
1477 | * 'data_skb' variable so that it will be used below for data | |
1478 | * copying. We keep 'skb' for everything else, including | |
1479 | * freeing both later. | |
1dacc76d | 1480 | */ |
68d6ac6d JB |
1481 | if (flags & MSG_CMSG_COMPAT) |
1482 | data_skb = skb_shinfo(skb)->frag_list; | |
1dacc76d JB |
1483 | } |
1484 | #endif | |
1485 | ||
1da177e4 LT |
1486 | msg->msg_namelen = 0; |
1487 | ||
68d6ac6d | 1488 | copied = data_skb->len; |
1da177e4 LT |
1489 | if (len < copied) { |
1490 | msg->msg_flags |= MSG_TRUNC; | |
1491 | copied = len; | |
1492 | } | |
1493 | ||
68d6ac6d JB |
1494 | skb_reset_transport_header(data_skb); |
1495 | err = skb_copy_datagram_iovec(data_skb, 0, msg->msg_iov, copied); | |
1da177e4 LT |
1496 | |
1497 | if (msg->msg_name) { | |
6ac552fd | 1498 | struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name; |
1da177e4 LT |
1499 | addr->nl_family = AF_NETLINK; |
1500 | addr->nl_pad = 0; | |
15e47304 | 1501 | addr->nl_pid = NETLINK_CB(skb).portid; |
d629b836 | 1502 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
1503 | msg->msg_namelen = sizeof(*addr); |
1504 | } | |
1505 | ||
cc9a06cd PM |
1506 | if (nlk->flags & NETLINK_RECV_PKTINFO) |
1507 | netlink_cmsg_recv_pktinfo(msg, skb); | |
1508 | ||
1da177e4 LT |
1509 | if (NULL == siocb->scm) { |
1510 | memset(&scm, 0, sizeof(scm)); | |
1511 | siocb->scm = &scm; | |
1512 | } | |
1513 | siocb->scm->creds = *NETLINK_CREDS(skb); | |
188ccb55 | 1514 | if (flags & MSG_TRUNC) |
68d6ac6d | 1515 | copied = data_skb->len; |
daa3766e | 1516 | |
1da177e4 LT |
1517 | skb_free_datagram(sk, skb); |
1518 | ||
b44d211e AV |
1519 | if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) { |
1520 | ret = netlink_dump(sk); | |
1521 | if (ret) { | |
1522 | sk->sk_err = ret; | |
1523 | sk->sk_error_report(sk); | |
1524 | } | |
1525 | } | |
1da177e4 LT |
1526 | |
1527 | scm_recv(sock, msg, siocb->scm, flags); | |
1da177e4 LT |
1528 | out: |
1529 | netlink_rcv_wake(sk); | |
1530 | return err ? : copied; | |
1531 | } | |
1532 | ||
1533 | static void netlink_data_ready(struct sock *sk, int len) | |
1534 | { | |
cd40b7d3 | 1535 | BUG(); |
1da177e4 LT |
1536 | } |
1537 | ||
1538 | /* | |
746fac4d | 1539 | * We export these functions to other modules. They provide a |
1da177e4 LT |
1540 | * complete set of kernel non-blocking support for message |
1541 | * queueing. | |
1542 | */ | |
1543 | ||
1544 | struct sock * | |
9f00d977 PNA |
1545 | __netlink_kernel_create(struct net *net, int unit, struct module *module, |
1546 | struct netlink_kernel_cfg *cfg) | |
1da177e4 LT |
1547 | { |
1548 | struct socket *sock; | |
1549 | struct sock *sk; | |
77247bbb | 1550 | struct netlink_sock *nlk; |
5c398dc8 | 1551 | struct listeners *listeners = NULL; |
a31f2d17 PNA |
1552 | struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL; |
1553 | unsigned int groups; | |
1da177e4 | 1554 | |
fab2caf6 | 1555 | BUG_ON(!nl_table); |
1da177e4 | 1556 | |
6ac552fd | 1557 | if (unit < 0 || unit >= MAX_LINKS) |
1da177e4 LT |
1558 | return NULL; |
1559 | ||
1560 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
1561 | return NULL; | |
1562 | ||
23fe1866 PE |
1563 | /* |
1564 | * We have to just have a reference on the net from sk, but don't | |
1565 | * get_net it. Besides, we cannot get and then put the net here. | |
1566 | * So we create one inside init_net and the move it to net. | |
1567 | */ | |
1568 | ||
1569 | if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0) | |
1570 | goto out_sock_release_nosk; | |
1571 | ||
1572 | sk = sock->sk; | |
edf02087 | 1573 | sk_change_net(sk, net); |
4fdb3bb7 | 1574 | |
a31f2d17 | 1575 | if (!cfg || cfg->groups < 32) |
4277a083 | 1576 | groups = 32; |
a31f2d17 PNA |
1577 | else |
1578 | groups = cfg->groups; | |
4277a083 | 1579 | |
5c398dc8 | 1580 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
4277a083 PM |
1581 | if (!listeners) |
1582 | goto out_sock_release; | |
1583 | ||
1da177e4 | 1584 | sk->sk_data_ready = netlink_data_ready; |
a31f2d17 PNA |
1585 | if (cfg && cfg->input) |
1586 | nlk_sk(sk)->netlink_rcv = cfg->input; | |
1da177e4 | 1587 | |
b4b51029 | 1588 | if (netlink_insert(sk, net, 0)) |
77247bbb | 1589 | goto out_sock_release; |
4fdb3bb7 | 1590 | |
77247bbb PM |
1591 | nlk = nlk_sk(sk); |
1592 | nlk->flags |= NETLINK_KERNEL_SOCKET; | |
4fdb3bb7 | 1593 | |
4fdb3bb7 | 1594 | netlink_table_grab(); |
b4b51029 EB |
1595 | if (!nl_table[unit].registered) { |
1596 | nl_table[unit].groups = groups; | |
5c398dc8 | 1597 | rcu_assign_pointer(nl_table[unit].listeners, listeners); |
b4b51029 EB |
1598 | nl_table[unit].cb_mutex = cb_mutex; |
1599 | nl_table[unit].module = module; | |
9785e10a PNA |
1600 | if (cfg) { |
1601 | nl_table[unit].bind = cfg->bind; | |
1602 | nl_table[unit].flags = cfg->flags; | |
1603 | } | |
b4b51029 | 1604 | nl_table[unit].registered = 1; |
f937f1f4 JJ |
1605 | } else { |
1606 | kfree(listeners); | |
869e58f8 | 1607 | nl_table[unit].registered++; |
b4b51029 | 1608 | } |
4fdb3bb7 | 1609 | netlink_table_ungrab(); |
77247bbb PM |
1610 | return sk; |
1611 | ||
4fdb3bb7 | 1612 | out_sock_release: |
4277a083 | 1613 | kfree(listeners); |
9dfbec1f | 1614 | netlink_kernel_release(sk); |
23fe1866 PE |
1615 | return NULL; |
1616 | ||
1617 | out_sock_release_nosk: | |
4fdb3bb7 | 1618 | sock_release(sock); |
77247bbb | 1619 | return NULL; |
1da177e4 | 1620 | } |
9f00d977 | 1621 | EXPORT_SYMBOL(__netlink_kernel_create); |
b7c6ba6e DL |
1622 | |
1623 | void | |
1624 | netlink_kernel_release(struct sock *sk) | |
1625 | { | |
edf02087 | 1626 | sk_release_kernel(sk); |
b7c6ba6e DL |
1627 | } |
1628 | EXPORT_SYMBOL(netlink_kernel_release); | |
1629 | ||
d136f1bd | 1630 | int __netlink_change_ngroups(struct sock *sk, unsigned int groups) |
b4ff4f04 | 1631 | { |
5c398dc8 | 1632 | struct listeners *new, *old; |
b4ff4f04 | 1633 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; |
b4ff4f04 JB |
1634 | |
1635 | if (groups < 32) | |
1636 | groups = 32; | |
1637 | ||
b4ff4f04 | 1638 | if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { |
5c398dc8 ED |
1639 | new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC); |
1640 | if (!new) | |
d136f1bd | 1641 | return -ENOMEM; |
6d772ac5 | 1642 | old = nl_deref_protected(tbl->listeners); |
5c398dc8 ED |
1643 | memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups)); |
1644 | rcu_assign_pointer(tbl->listeners, new); | |
1645 | ||
37b6b935 | 1646 | kfree_rcu(old, rcu); |
b4ff4f04 JB |
1647 | } |
1648 | tbl->groups = groups; | |
1649 | ||
d136f1bd JB |
1650 | return 0; |
1651 | } | |
1652 | ||
1653 | /** | |
1654 | * netlink_change_ngroups - change number of multicast groups | |
1655 | * | |
1656 | * This changes the number of multicast groups that are available | |
1657 | * on a certain netlink family. Note that it is not possible to | |
1658 | * change the number of groups to below 32. Also note that it does | |
1659 | * not implicitly call netlink_clear_multicast_users() when the | |
1660 | * number of groups is reduced. | |
1661 | * | |
1662 | * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). | |
1663 | * @groups: The new number of groups. | |
1664 | */ | |
1665 | int netlink_change_ngroups(struct sock *sk, unsigned int groups) | |
1666 | { | |
1667 | int err; | |
1668 | ||
1669 | netlink_table_grab(); | |
1670 | err = __netlink_change_ngroups(sk, groups); | |
b4ff4f04 | 1671 | netlink_table_ungrab(); |
d136f1bd | 1672 | |
b4ff4f04 JB |
1673 | return err; |
1674 | } | |
b4ff4f04 | 1675 | |
b8273570 JB |
1676 | void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group) |
1677 | { | |
1678 | struct sock *sk; | |
1679 | struct hlist_node *node; | |
1680 | struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; | |
1681 | ||
1682 | sk_for_each_bound(sk, node, &tbl->mc_list) | |
1683 | netlink_update_socket_mc(nlk_sk(sk), group, 0); | |
1684 | } | |
1685 | ||
84659eb5 JB |
1686 | /** |
1687 | * netlink_clear_multicast_users - kick off multicast listeners | |
1688 | * | |
1689 | * This function removes all listeners from the given group. | |
1690 | * @ksk: The kernel netlink socket, as returned by | |
1691 | * netlink_kernel_create(). | |
1692 | * @group: The multicast group to clear. | |
1693 | */ | |
1694 | void netlink_clear_multicast_users(struct sock *ksk, unsigned int group) | |
1695 | { | |
84659eb5 | 1696 | netlink_table_grab(); |
b8273570 | 1697 | __netlink_clear_multicast_users(ksk, group); |
84659eb5 JB |
1698 | netlink_table_ungrab(); |
1699 | } | |
84659eb5 | 1700 | |
a46621a3 | 1701 | struct nlmsghdr * |
15e47304 | 1702 | __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags) |
a46621a3 DV |
1703 | { |
1704 | struct nlmsghdr *nlh; | |
1705 | int size = NLMSG_LENGTH(len); | |
1706 | ||
1707 | nlh = (struct nlmsghdr*)skb_put(skb, NLMSG_ALIGN(size)); | |
1708 | nlh->nlmsg_type = type; | |
1709 | nlh->nlmsg_len = size; | |
1710 | nlh->nlmsg_flags = flags; | |
15e47304 | 1711 | nlh->nlmsg_pid = portid; |
a46621a3 DV |
1712 | nlh->nlmsg_seq = seq; |
1713 | if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0) | |
1714 | memset(NLMSG_DATA(nlh) + len, 0, NLMSG_ALIGN(size) - size); | |
1715 | return nlh; | |
1716 | } | |
1717 | EXPORT_SYMBOL(__nlmsg_put); | |
1718 | ||
1da177e4 LT |
1719 | /* |
1720 | * It looks a bit ugly. | |
1721 | * It would be better to create kernel thread. | |
1722 | */ | |
1723 | ||
1724 | static int netlink_dump(struct sock *sk) | |
1725 | { | |
1726 | struct netlink_sock *nlk = nlk_sk(sk); | |
1727 | struct netlink_callback *cb; | |
c7ac8679 | 1728 | struct sk_buff *skb = NULL; |
1da177e4 | 1729 | struct nlmsghdr *nlh; |
bf8b79e4 | 1730 | int len, err = -ENOBUFS; |
c7ac8679 | 1731 | int alloc_size; |
1da177e4 | 1732 | |
af65bdfc | 1733 | mutex_lock(nlk->cb_mutex); |
1da177e4 LT |
1734 | |
1735 | cb = nlk->cb; | |
1736 | if (cb == NULL) { | |
bf8b79e4 TG |
1737 | err = -EINVAL; |
1738 | goto errout_skb; | |
1da177e4 LT |
1739 | } |
1740 | ||
c7ac8679 GR |
1741 | alloc_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE); |
1742 | ||
1743 | skb = sock_rmalloc(sk, alloc_size, 0, GFP_KERNEL); | |
1744 | if (!skb) | |
c63d6ea3 | 1745 | goto errout_skb; |
c7ac8679 | 1746 | |
1da177e4 LT |
1747 | len = cb->dump(skb, cb); |
1748 | ||
1749 | if (len > 0) { | |
af65bdfc | 1750 | mutex_unlock(nlk->cb_mutex); |
b1153f29 SH |
1751 | |
1752 | if (sk_filter(sk, skb)) | |
1753 | kfree_skb(skb); | |
4a7e7c2a ED |
1754 | else |
1755 | __netlink_sendskb(sk, skb); | |
1da177e4 LT |
1756 | return 0; |
1757 | } | |
1758 | ||
bf8b79e4 TG |
1759 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); |
1760 | if (!nlh) | |
1761 | goto errout_skb; | |
1762 | ||
670dc283 JB |
1763 | nl_dump_check_consistent(cb, nlh); |
1764 | ||
bf8b79e4 TG |
1765 | memcpy(nlmsg_data(nlh), &len, sizeof(len)); |
1766 | ||
b1153f29 SH |
1767 | if (sk_filter(sk, skb)) |
1768 | kfree_skb(skb); | |
4a7e7c2a ED |
1769 | else |
1770 | __netlink_sendskb(sk, skb); | |
1da177e4 | 1771 | |
a8f74b22 TG |
1772 | if (cb->done) |
1773 | cb->done(cb); | |
1da177e4 | 1774 | nlk->cb = NULL; |
af65bdfc | 1775 | mutex_unlock(nlk->cb_mutex); |
1da177e4 | 1776 | |
6dc878a8 | 1777 | module_put(cb->module); |
bfb253c9 | 1778 | netlink_consume_callback(cb); |
1da177e4 | 1779 | return 0; |
1797754e | 1780 | |
bf8b79e4 | 1781 | errout_skb: |
af65bdfc | 1782 | mutex_unlock(nlk->cb_mutex); |
bf8b79e4 | 1783 | kfree_skb(skb); |
bf8b79e4 | 1784 | return err; |
1da177e4 LT |
1785 | } |
1786 | ||
6dc878a8 G |
1787 | int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, |
1788 | const struct nlmsghdr *nlh, | |
1789 | struct netlink_dump_control *control) | |
1da177e4 LT |
1790 | { |
1791 | struct netlink_callback *cb; | |
1792 | struct sock *sk; | |
1793 | struct netlink_sock *nlk; | |
b44d211e | 1794 | int ret; |
1da177e4 | 1795 | |
0da974f4 | 1796 | cb = kzalloc(sizeof(*cb), GFP_KERNEL); |
1da177e4 LT |
1797 | if (cb == NULL) |
1798 | return -ENOBUFS; | |
1799 | ||
80d326fa PNA |
1800 | cb->dump = control->dump; |
1801 | cb->done = control->done; | |
1da177e4 | 1802 | cb->nlh = nlh; |
7175c883 | 1803 | cb->data = control->data; |
6dc878a8 | 1804 | cb->module = control->module; |
80d326fa | 1805 | cb->min_dump_alloc = control->min_dump_alloc; |
1da177e4 LT |
1806 | atomic_inc(&skb->users); |
1807 | cb->skb = skb; | |
1808 | ||
15e47304 | 1809 | sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).portid); |
1da177e4 LT |
1810 | if (sk == NULL) { |
1811 | netlink_destroy_callback(cb); | |
1812 | return -ECONNREFUSED; | |
1813 | } | |
1814 | nlk = nlk_sk(sk); | |
6dc878a8 | 1815 | |
af65bdfc | 1816 | mutex_lock(nlk->cb_mutex); |
6dc878a8 | 1817 | /* A dump is in progress... */ |
3f660d66 | 1818 | if (nlk->cb) { |
af65bdfc | 1819 | mutex_unlock(nlk->cb_mutex); |
1da177e4 | 1820 | netlink_destroy_callback(cb); |
6dc878a8 G |
1821 | ret = -EBUSY; |
1822 | goto out; | |
1da177e4 | 1823 | } |
6dc878a8 G |
1824 | /* add reference of module which cb->dump belongs to */ |
1825 | if (!try_module_get(cb->module)) { | |
1826 | mutex_unlock(nlk->cb_mutex); | |
1827 | netlink_destroy_callback(cb); | |
1828 | ret = -EPROTONOSUPPORT; | |
1829 | goto out; | |
1830 | } | |
1831 | ||
1da177e4 | 1832 | nlk->cb = cb; |
af65bdfc | 1833 | mutex_unlock(nlk->cb_mutex); |
1da177e4 | 1834 | |
b44d211e | 1835 | ret = netlink_dump(sk); |
6dc878a8 | 1836 | out: |
1da177e4 | 1837 | sock_put(sk); |
5c58298c | 1838 | |
b44d211e AV |
1839 | if (ret) |
1840 | return ret; | |
1841 | ||
5c58298c DL |
1842 | /* We successfully started a dump, by returning -EINTR we |
1843 | * signal not to send ACK even if it was requested. | |
1844 | */ | |
1845 | return -EINTR; | |
1da177e4 | 1846 | } |
6dc878a8 | 1847 | EXPORT_SYMBOL(__netlink_dump_start); |
1da177e4 LT |
1848 | |
1849 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) | |
1850 | { | |
1851 | struct sk_buff *skb; | |
1852 | struct nlmsghdr *rep; | |
1853 | struct nlmsgerr *errmsg; | |
339bf98f | 1854 | size_t payload = sizeof(*errmsg); |
1da177e4 | 1855 | |
339bf98f TG |
1856 | /* error messages get the original request appened */ |
1857 | if (err) | |
1858 | payload += nlmsg_len(nlh); | |
1da177e4 | 1859 | |
339bf98f | 1860 | skb = nlmsg_new(payload, GFP_KERNEL); |
1da177e4 LT |
1861 | if (!skb) { |
1862 | struct sock *sk; | |
1863 | ||
3b1e0a65 | 1864 | sk = netlink_lookup(sock_net(in_skb->sk), |
b4b51029 | 1865 | in_skb->sk->sk_protocol, |
15e47304 | 1866 | NETLINK_CB(in_skb).portid); |
1da177e4 LT |
1867 | if (sk) { |
1868 | sk->sk_err = ENOBUFS; | |
1869 | sk->sk_error_report(sk); | |
1870 | sock_put(sk); | |
1871 | } | |
1872 | return; | |
1873 | } | |
1874 | ||
15e47304 | 1875 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, |
5dba93ae | 1876 | NLMSG_ERROR, payload, 0); |
bf8b79e4 | 1877 | errmsg = nlmsg_data(rep); |
1da177e4 | 1878 | errmsg->error = err; |
bf8b79e4 | 1879 | memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh)); |
15e47304 | 1880 | netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT); |
1da177e4 | 1881 | } |
6ac552fd | 1882 | EXPORT_SYMBOL(netlink_ack); |
1da177e4 | 1883 | |
cd40b7d3 | 1884 | int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
1d00a4eb | 1885 | struct nlmsghdr *)) |
82ace47a | 1886 | { |
82ace47a TG |
1887 | struct nlmsghdr *nlh; |
1888 | int err; | |
1889 | ||
1890 | while (skb->len >= nlmsg_total_size(0)) { | |
cd40b7d3 DL |
1891 | int msglen; |
1892 | ||
b529ccf2 | 1893 | nlh = nlmsg_hdr(skb); |
d35b6856 | 1894 | err = 0; |
82ace47a | 1895 | |
ad8e4b75 | 1896 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
1897 | return 0; |
1898 | ||
d35b6856 TG |
1899 | /* Only requests are handled by the kernel */ |
1900 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | |
5c58298c | 1901 | goto ack; |
45e7ae7f TG |
1902 | |
1903 | /* Skip control messages */ | |
1904 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | |
5c58298c | 1905 | goto ack; |
d35b6856 | 1906 | |
1d00a4eb | 1907 | err = cb(skb, nlh); |
5c58298c DL |
1908 | if (err == -EINTR) |
1909 | goto skip; | |
1910 | ||
1911 | ack: | |
d35b6856 | 1912 | if (nlh->nlmsg_flags & NLM_F_ACK || err) |
82ace47a | 1913 | netlink_ack(skb, nlh, err); |
82ace47a | 1914 | |
5c58298c | 1915 | skip: |
6ac552fd | 1916 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
cd40b7d3 DL |
1917 | if (msglen > skb->len) |
1918 | msglen = skb->len; | |
1919 | skb_pull(skb, msglen); | |
82ace47a TG |
1920 | } |
1921 | ||
1922 | return 0; | |
1923 | } | |
6ac552fd | 1924 | EXPORT_SYMBOL(netlink_rcv_skb); |
82ace47a | 1925 | |
d387f6ad TG |
1926 | /** |
1927 | * nlmsg_notify - send a notification netlink message | |
1928 | * @sk: netlink socket to use | |
1929 | * @skb: notification message | |
15e47304 | 1930 | * @portid: destination netlink portid for reports or 0 |
d387f6ad TG |
1931 | * @group: destination multicast group or 0 |
1932 | * @report: 1 to report back, 0 to disable | |
1933 | * @flags: allocation flags | |
1934 | */ | |
15e47304 | 1935 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, |
d387f6ad TG |
1936 | unsigned int group, int report, gfp_t flags) |
1937 | { | |
1938 | int err = 0; | |
1939 | ||
1940 | if (group) { | |
15e47304 | 1941 | int exclude_portid = 0; |
d387f6ad TG |
1942 | |
1943 | if (report) { | |
1944 | atomic_inc(&skb->users); | |
15e47304 | 1945 | exclude_portid = portid; |
d387f6ad TG |
1946 | } |
1947 | ||
1ce85fe4 PNA |
1948 | /* errors reported via destination sk->sk_err, but propagate |
1949 | * delivery errors if NETLINK_BROADCAST_ERROR flag is set */ | |
15e47304 | 1950 | err = nlmsg_multicast(sk, skb, exclude_portid, group, flags); |
d387f6ad TG |
1951 | } |
1952 | ||
1ce85fe4 PNA |
1953 | if (report) { |
1954 | int err2; | |
1955 | ||
15e47304 | 1956 | err2 = nlmsg_unicast(sk, skb, portid); |
1ce85fe4 PNA |
1957 | if (!err || err == -ESRCH) |
1958 | err = err2; | |
1959 | } | |
d387f6ad TG |
1960 | |
1961 | return err; | |
1962 | } | |
6ac552fd | 1963 | EXPORT_SYMBOL(nlmsg_notify); |
d387f6ad | 1964 | |
1da177e4 LT |
1965 | #ifdef CONFIG_PROC_FS |
1966 | struct nl_seq_iter { | |
e372c414 | 1967 | struct seq_net_private p; |
1da177e4 LT |
1968 | int link; |
1969 | int hash_idx; | |
1970 | }; | |
1971 | ||
1972 | static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) | |
1973 | { | |
1974 | struct nl_seq_iter *iter = seq->private; | |
1975 | int i, j; | |
1976 | struct sock *s; | |
1977 | struct hlist_node *node; | |
1978 | loff_t off = 0; | |
1979 | ||
6ac552fd | 1980 | for (i = 0; i < MAX_LINKS; i++) { |
15e47304 | 1981 | struct nl_portid_hash *hash = &nl_table[i].hash; |
1da177e4 LT |
1982 | |
1983 | for (j = 0; j <= hash->mask; j++) { | |
1984 | sk_for_each(s, node, &hash->table[j]) { | |
1218854a | 1985 | if (sock_net(s) != seq_file_net(seq)) |
b4b51029 | 1986 | continue; |
1da177e4 LT |
1987 | if (off == pos) { |
1988 | iter->link = i; | |
1989 | iter->hash_idx = j; | |
1990 | return s; | |
1991 | } | |
1992 | ++off; | |
1993 | } | |
1994 | } | |
1995 | } | |
1996 | return NULL; | |
1997 | } | |
1998 | ||
1999 | static void *netlink_seq_start(struct seq_file *seq, loff_t *pos) | |
9a429c49 | 2000 | __acquires(nl_table_lock) |
1da177e4 LT |
2001 | { |
2002 | read_lock(&nl_table_lock); | |
2003 | return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
2004 | } | |
2005 | ||
2006 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2007 | { | |
2008 | struct sock *s; | |
2009 | struct nl_seq_iter *iter; | |
2010 | int i, j; | |
2011 | ||
2012 | ++*pos; | |
2013 | ||
2014 | if (v == SEQ_START_TOKEN) | |
2015 | return netlink_seq_socket_idx(seq, 0); | |
746fac4d | 2016 | |
b4b51029 EB |
2017 | iter = seq->private; |
2018 | s = v; | |
2019 | do { | |
2020 | s = sk_next(s); | |
1218854a | 2021 | } while (s && sock_net(s) != seq_file_net(seq)); |
1da177e4 LT |
2022 | if (s) |
2023 | return s; | |
2024 | ||
1da177e4 LT |
2025 | i = iter->link; |
2026 | j = iter->hash_idx + 1; | |
2027 | ||
2028 | do { | |
15e47304 | 2029 | struct nl_portid_hash *hash = &nl_table[i].hash; |
1da177e4 LT |
2030 | |
2031 | for (; j <= hash->mask; j++) { | |
2032 | s = sk_head(&hash->table[j]); | |
1218854a | 2033 | while (s && sock_net(s) != seq_file_net(seq)) |
b4b51029 | 2034 | s = sk_next(s); |
1da177e4 LT |
2035 | if (s) { |
2036 | iter->link = i; | |
2037 | iter->hash_idx = j; | |
2038 | return s; | |
2039 | } | |
2040 | } | |
2041 | ||
2042 | j = 0; | |
2043 | } while (++i < MAX_LINKS); | |
2044 | ||
2045 | return NULL; | |
2046 | } | |
2047 | ||
2048 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
9a429c49 | 2049 | __releases(nl_table_lock) |
1da177e4 LT |
2050 | { |
2051 | read_unlock(&nl_table_lock); | |
2052 | } | |
2053 | ||
2054 | ||
2055 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
2056 | { | |
658cb354 | 2057 | if (v == SEQ_START_TOKEN) { |
1da177e4 LT |
2058 | seq_puts(seq, |
2059 | "sk Eth Pid Groups " | |
cf0aa4e0 | 2060 | "Rmem Wmem Dump Locks Drops Inode\n"); |
658cb354 | 2061 | } else { |
1da177e4 LT |
2062 | struct sock *s = v; |
2063 | struct netlink_sock *nlk = nlk_sk(s); | |
2064 | ||
9f1e0ad0 | 2065 | seq_printf(seq, "%pK %-3d %-6u %08x %-8d %-8d %pK %-8d %-8d %-8lu\n", |
1da177e4 LT |
2066 | s, |
2067 | s->sk_protocol, | |
15e47304 | 2068 | nlk->portid, |
513c2500 | 2069 | nlk->groups ? (u32)nlk->groups[0] : 0, |
31e6d363 ED |
2070 | sk_rmem_alloc_get(s), |
2071 | sk_wmem_alloc_get(s), | |
1da177e4 | 2072 | nlk->cb, |
38938bfe | 2073 | atomic_read(&s->sk_refcnt), |
cf0aa4e0 MY |
2074 | atomic_read(&s->sk_drops), |
2075 | sock_i_ino(s) | |
1da177e4 LT |
2076 | ); |
2077 | ||
2078 | } | |
2079 | return 0; | |
2080 | } | |
2081 | ||
56b3d975 | 2082 | static const struct seq_operations netlink_seq_ops = { |
1da177e4 LT |
2083 | .start = netlink_seq_start, |
2084 | .next = netlink_seq_next, | |
2085 | .stop = netlink_seq_stop, | |
2086 | .show = netlink_seq_show, | |
2087 | }; | |
2088 | ||
2089 | ||
2090 | static int netlink_seq_open(struct inode *inode, struct file *file) | |
2091 | { | |
e372c414 DL |
2092 | return seq_open_net(inode, file, &netlink_seq_ops, |
2093 | sizeof(struct nl_seq_iter)); | |
b4b51029 EB |
2094 | } |
2095 | ||
da7071d7 | 2096 | static const struct file_operations netlink_seq_fops = { |
1da177e4 LT |
2097 | .owner = THIS_MODULE, |
2098 | .open = netlink_seq_open, | |
2099 | .read = seq_read, | |
2100 | .llseek = seq_lseek, | |
e372c414 | 2101 | .release = seq_release_net, |
1da177e4 LT |
2102 | }; |
2103 | ||
2104 | #endif | |
2105 | ||
2106 | int netlink_register_notifier(struct notifier_block *nb) | |
2107 | { | |
e041c683 | 2108 | return atomic_notifier_chain_register(&netlink_chain, nb); |
1da177e4 | 2109 | } |
6ac552fd | 2110 | EXPORT_SYMBOL(netlink_register_notifier); |
1da177e4 LT |
2111 | |
2112 | int netlink_unregister_notifier(struct notifier_block *nb) | |
2113 | { | |
e041c683 | 2114 | return atomic_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 | 2115 | } |
6ac552fd | 2116 | EXPORT_SYMBOL(netlink_unregister_notifier); |
746fac4d | 2117 | |
90ddc4f0 | 2118 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
2119 | .family = PF_NETLINK, |
2120 | .owner = THIS_MODULE, | |
2121 | .release = netlink_release, | |
2122 | .bind = netlink_bind, | |
2123 | .connect = netlink_connect, | |
2124 | .socketpair = sock_no_socketpair, | |
2125 | .accept = sock_no_accept, | |
2126 | .getname = netlink_getname, | |
2127 | .poll = datagram_poll, | |
2128 | .ioctl = sock_no_ioctl, | |
2129 | .listen = sock_no_listen, | |
2130 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
2131 | .setsockopt = netlink_setsockopt, |
2132 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
2133 | .sendmsg = netlink_sendmsg, |
2134 | .recvmsg = netlink_recvmsg, | |
2135 | .mmap = sock_no_mmap, | |
2136 | .sendpage = sock_no_sendpage, | |
2137 | }; | |
2138 | ||
ec1b4cf7 | 2139 | static const struct net_proto_family netlink_family_ops = { |
1da177e4 LT |
2140 | .family = PF_NETLINK, |
2141 | .create = netlink_create, | |
2142 | .owner = THIS_MODULE, /* for consistency 8) */ | |
2143 | }; | |
2144 | ||
4665079c | 2145 | static int __net_init netlink_net_init(struct net *net) |
b4b51029 EB |
2146 | { |
2147 | #ifdef CONFIG_PROC_FS | |
2148 | if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops)) | |
2149 | return -ENOMEM; | |
2150 | #endif | |
2151 | return 0; | |
2152 | } | |
2153 | ||
4665079c | 2154 | static void __net_exit netlink_net_exit(struct net *net) |
b4b51029 EB |
2155 | { |
2156 | #ifdef CONFIG_PROC_FS | |
2157 | proc_net_remove(net, "netlink"); | |
2158 | #endif | |
2159 | } | |
2160 | ||
b963ea89 DM |
2161 | static void __init netlink_add_usersock_entry(void) |
2162 | { | |
5c398dc8 | 2163 | struct listeners *listeners; |
b963ea89 DM |
2164 | int groups = 32; |
2165 | ||
5c398dc8 | 2166 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
b963ea89 | 2167 | if (!listeners) |
5c398dc8 | 2168 | panic("netlink_add_usersock_entry: Cannot allocate listeners\n"); |
b963ea89 DM |
2169 | |
2170 | netlink_table_grab(); | |
2171 | ||
2172 | nl_table[NETLINK_USERSOCK].groups = groups; | |
5c398dc8 | 2173 | rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners); |
b963ea89 DM |
2174 | nl_table[NETLINK_USERSOCK].module = THIS_MODULE; |
2175 | nl_table[NETLINK_USERSOCK].registered = 1; | |
9785e10a | 2176 | nl_table[NETLINK_USERSOCK].flags = NL_CFG_F_NONROOT_SEND; |
b963ea89 DM |
2177 | |
2178 | netlink_table_ungrab(); | |
2179 | } | |
2180 | ||
022cbae6 | 2181 | static struct pernet_operations __net_initdata netlink_net_ops = { |
b4b51029 EB |
2182 | .init = netlink_net_init, |
2183 | .exit = netlink_net_exit, | |
2184 | }; | |
2185 | ||
1da177e4 LT |
2186 | static int __init netlink_proto_init(void) |
2187 | { | |
2188 | struct sk_buff *dummy_skb; | |
2189 | int i; | |
26ff5ddc | 2190 | unsigned long limit; |
1da177e4 LT |
2191 | unsigned int order; |
2192 | int err = proto_register(&netlink_proto, 0); | |
2193 | ||
2194 | if (err != 0) | |
2195 | goto out; | |
2196 | ||
ef047f5e | 2197 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb)); |
1da177e4 | 2198 | |
0da974f4 | 2199 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
2200 | if (!nl_table) |
2201 | goto panic; | |
1da177e4 | 2202 | |
4481374c JB |
2203 | if (totalram_pages >= (128 * 1024)) |
2204 | limit = totalram_pages >> (21 - PAGE_SHIFT); | |
1da177e4 | 2205 | else |
4481374c | 2206 | limit = totalram_pages >> (23 - PAGE_SHIFT); |
1da177e4 | 2207 | |
26ff5ddc DC |
2208 | order = get_bitmask_order(limit) - 1 + PAGE_SHIFT; |
2209 | limit = (1UL << order) / sizeof(struct hlist_head); | |
2210 | order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1; | |
1da177e4 LT |
2211 | |
2212 | for (i = 0; i < MAX_LINKS; i++) { | |
15e47304 | 2213 | struct nl_portid_hash *hash = &nl_table[i].hash; |
1da177e4 | 2214 | |
15e47304 | 2215 | hash->table = nl_portid_hash_zalloc(1 * sizeof(*hash->table)); |
1da177e4 LT |
2216 | if (!hash->table) { |
2217 | while (i-- > 0) | |
15e47304 | 2218 | nl_portid_hash_free(nl_table[i].hash.table, |
1da177e4 LT |
2219 | 1 * sizeof(*hash->table)); |
2220 | kfree(nl_table); | |
fab2caf6 | 2221 | goto panic; |
1da177e4 | 2222 | } |
1da177e4 LT |
2223 | hash->max_shift = order; |
2224 | hash->shift = 0; | |
2225 | hash->mask = 0; | |
2226 | hash->rehash_time = jiffies; | |
2227 | } | |
2228 | ||
b963ea89 DM |
2229 | netlink_add_usersock_entry(); |
2230 | ||
1da177e4 | 2231 | sock_register(&netlink_family_ops); |
b4b51029 | 2232 | register_pernet_subsys(&netlink_net_ops); |
746fac4d | 2233 | /* The netlink device handler may be needed early. */ |
1da177e4 LT |
2234 | rtnetlink_init(); |
2235 | out: | |
2236 | return err; | |
fab2caf6 AM |
2237 | panic: |
2238 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
2239 | } |
2240 | ||
1da177e4 | 2241 | core_initcall(netlink_proto_init); |