]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * NETLINK Kernel-user communication protocol. | |
3 | * | |
113aa838 | 4 | * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk> |
1da177e4 LT |
5 | * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
746fac4d | 11 | * |
1da177e4 LT |
12 | * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith |
13 | * added netlink_proto_exit | |
14 | * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br> | |
15 | * use nlk_sk, as sk->protinfo is on a diet 8) | |
4fdb3bb7 HW |
16 | * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org> |
17 | * - inc module use count of module that owns | |
18 | * the kernel socket in case userspace opens | |
19 | * socket of same protocol | |
20 | * - remove all module support, since netlink is | |
21 | * mandatory if CONFIG_NET=y these days | |
1da177e4 LT |
22 | */ |
23 | ||
1da177e4 LT |
24 | #include <linux/module.h> |
25 | ||
4fc268d2 | 26 | #include <linux/capability.h> |
1da177e4 LT |
27 | #include <linux/kernel.h> |
28 | #include <linux/init.h> | |
1da177e4 LT |
29 | #include <linux/signal.h> |
30 | #include <linux/sched.h> | |
31 | #include <linux/errno.h> | |
32 | #include <linux/string.h> | |
33 | #include <linux/stat.h> | |
34 | #include <linux/socket.h> | |
35 | #include <linux/un.h> | |
36 | #include <linux/fcntl.h> | |
37 | #include <linux/termios.h> | |
38 | #include <linux/sockios.h> | |
39 | #include <linux/net.h> | |
40 | #include <linux/fs.h> | |
41 | #include <linux/slab.h> | |
42 | #include <asm/uaccess.h> | |
43 | #include <linux/skbuff.h> | |
44 | #include <linux/netdevice.h> | |
45 | #include <linux/rtnetlink.h> | |
46 | #include <linux/proc_fs.h> | |
47 | #include <linux/seq_file.h> | |
1da177e4 LT |
48 | #include <linux/notifier.h> |
49 | #include <linux/security.h> | |
50 | #include <linux/jhash.h> | |
51 | #include <linux/jiffies.h> | |
52 | #include <linux/random.h> | |
53 | #include <linux/bitops.h> | |
54 | #include <linux/mm.h> | |
55 | #include <linux/types.h> | |
54e0f520 | 56 | #include <linux/audit.h> |
af65bdfc | 57 | #include <linux/mutex.h> |
54e0f520 | 58 | |
457c4cbc | 59 | #include <net/net_namespace.h> |
1da177e4 LT |
60 | #include <net/sock.h> |
61 | #include <net/scm.h> | |
82ace47a | 62 | #include <net/netlink.h> |
1da177e4 | 63 | |
f7fa9b10 | 64 | #define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8) |
b4ff4f04 | 65 | #define NLGRPLONGS(x) (NLGRPSZ(x)/sizeof(unsigned long)) |
1da177e4 LT |
66 | |
67 | struct netlink_sock { | |
68 | /* struct sock has to be the first member of netlink_sock */ | |
69 | struct sock sk; | |
70 | u32 pid; | |
1da177e4 | 71 | u32 dst_pid; |
d629b836 | 72 | u32 dst_group; |
f7fa9b10 PM |
73 | u32 flags; |
74 | u32 subscriptions; | |
75 | u32 ngroups; | |
76 | unsigned long *groups; | |
1da177e4 LT |
77 | unsigned long state; |
78 | wait_queue_head_t wait; | |
79 | struct netlink_callback *cb; | |
af65bdfc PM |
80 | struct mutex *cb_mutex; |
81 | struct mutex cb_def_mutex; | |
cd40b7d3 | 82 | void (*netlink_rcv)(struct sk_buff *skb); |
77247bbb | 83 | struct module *module; |
1da177e4 LT |
84 | }; |
85 | ||
77247bbb | 86 | #define NETLINK_KERNEL_SOCKET 0x1 |
9a4595bc | 87 | #define NETLINK_RECV_PKTINFO 0x2 |
be0c22a4 | 88 | #define NETLINK_BROADCAST_SEND_ERROR 0x4 |
38938bfe | 89 | #define NETLINK_RECV_NO_ENOBUFS 0x8 |
77247bbb | 90 | |
1da177e4 LT |
91 | static inline struct netlink_sock *nlk_sk(struct sock *sk) |
92 | { | |
32b21e03 | 93 | return container_of(sk, struct netlink_sock, sk); |
1da177e4 LT |
94 | } |
95 | ||
aed81560 DL |
96 | static inline int netlink_is_kernel(struct sock *sk) |
97 | { | |
98 | return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET; | |
99 | } | |
100 | ||
1da177e4 LT |
101 | struct nl_pid_hash { |
102 | struct hlist_head *table; | |
103 | unsigned long rehash_time; | |
104 | ||
105 | unsigned int mask; | |
106 | unsigned int shift; | |
107 | ||
108 | unsigned int entries; | |
109 | unsigned int max_shift; | |
110 | ||
111 | u32 rnd; | |
112 | }; | |
113 | ||
114 | struct netlink_table { | |
115 | struct nl_pid_hash hash; | |
116 | struct hlist_head mc_list; | |
4277a083 | 117 | unsigned long *listeners; |
1da177e4 | 118 | unsigned int nl_nonroot; |
f7fa9b10 | 119 | unsigned int groups; |
af65bdfc | 120 | struct mutex *cb_mutex; |
77247bbb | 121 | struct module *module; |
ab33a171 | 122 | int registered; |
1da177e4 LT |
123 | }; |
124 | ||
125 | static struct netlink_table *nl_table; | |
126 | ||
127 | static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); | |
128 | ||
129 | static int netlink_dump(struct sock *sk); | |
130 | static void netlink_destroy_callback(struct netlink_callback *cb); | |
131 | ||
132 | static DEFINE_RWLOCK(nl_table_lock); | |
133 | static atomic_t nl_table_users = ATOMIC_INIT(0); | |
134 | ||
e041c683 | 135 | static ATOMIC_NOTIFIER_HEAD(netlink_chain); |
1da177e4 | 136 | |
d629b836 PM |
137 | static u32 netlink_group_mask(u32 group) |
138 | { | |
139 | return group ? 1 << (group - 1) : 0; | |
140 | } | |
141 | ||
1da177e4 LT |
142 | static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid) |
143 | { | |
144 | return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask]; | |
145 | } | |
146 | ||
147 | static void netlink_sock_destruct(struct sock *sk) | |
148 | { | |
3f660d66 HX |
149 | struct netlink_sock *nlk = nlk_sk(sk); |
150 | ||
3f660d66 HX |
151 | if (nlk->cb) { |
152 | if (nlk->cb->done) | |
153 | nlk->cb->done(nlk->cb); | |
154 | netlink_destroy_callback(nlk->cb); | |
155 | } | |
156 | ||
1da177e4 LT |
157 | skb_queue_purge(&sk->sk_receive_queue); |
158 | ||
159 | if (!sock_flag(sk, SOCK_DEAD)) { | |
6ac552fd | 160 | printk(KERN_ERR "Freeing alive netlink socket %p\n", sk); |
1da177e4 LT |
161 | return; |
162 | } | |
547b792c IJ |
163 | |
164 | WARN_ON(atomic_read(&sk->sk_rmem_alloc)); | |
165 | WARN_ON(atomic_read(&sk->sk_wmem_alloc)); | |
166 | WARN_ON(nlk_sk(sk)->groups); | |
1da177e4 LT |
167 | } |
168 | ||
6ac552fd PM |
169 | /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on |
170 | * SMP. Look, when several writers sleep and reader wakes them up, all but one | |
1da177e4 LT |
171 | * immediately hit write lock and grab all the cpus. Exclusive sleep solves |
172 | * this, _but_ remember, it adds useless work on UP machines. | |
173 | */ | |
174 | ||
175 | static void netlink_table_grab(void) | |
9a429c49 | 176 | __acquires(nl_table_lock) |
1da177e4 | 177 | { |
6abd219c | 178 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
179 | |
180 | if (atomic_read(&nl_table_users)) { | |
181 | DECLARE_WAITQUEUE(wait, current); | |
182 | ||
183 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
6ac552fd | 184 | for (;;) { |
1da177e4 LT |
185 | set_current_state(TASK_UNINTERRUPTIBLE); |
186 | if (atomic_read(&nl_table_users) == 0) | |
187 | break; | |
6abd219c | 188 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 189 | schedule(); |
6abd219c | 190 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
191 | } |
192 | ||
193 | __set_current_state(TASK_RUNNING); | |
194 | remove_wait_queue(&nl_table_wait, &wait); | |
195 | } | |
196 | } | |
197 | ||
3f252526 | 198 | static void netlink_table_ungrab(void) |
9a429c49 | 199 | __releases(nl_table_lock) |
1da177e4 | 200 | { |
6abd219c | 201 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
202 | wake_up(&nl_table_wait); |
203 | } | |
204 | ||
6ac552fd | 205 | static inline void |
1da177e4 LT |
206 | netlink_lock_table(void) |
207 | { | |
208 | /* read_lock() synchronizes us to netlink_table_grab */ | |
209 | ||
210 | read_lock(&nl_table_lock); | |
211 | atomic_inc(&nl_table_users); | |
212 | read_unlock(&nl_table_lock); | |
213 | } | |
214 | ||
6ac552fd | 215 | static inline void |
1da177e4 LT |
216 | netlink_unlock_table(void) |
217 | { | |
218 | if (atomic_dec_and_test(&nl_table_users)) | |
219 | wake_up(&nl_table_wait); | |
220 | } | |
221 | ||
6ac552fd PM |
222 | static inline struct sock *netlink_lookup(struct net *net, int protocol, |
223 | u32 pid) | |
1da177e4 LT |
224 | { |
225 | struct nl_pid_hash *hash = &nl_table[protocol].hash; | |
226 | struct hlist_head *head; | |
227 | struct sock *sk; | |
228 | struct hlist_node *node; | |
229 | ||
230 | read_lock(&nl_table_lock); | |
231 | head = nl_pid_hashfn(hash, pid); | |
232 | sk_for_each(sk, node, head) { | |
878628fb | 233 | if (net_eq(sock_net(sk), net) && (nlk_sk(sk)->pid == pid)) { |
1da177e4 LT |
234 | sock_hold(sk); |
235 | goto found; | |
236 | } | |
237 | } | |
238 | sk = NULL; | |
239 | found: | |
240 | read_unlock(&nl_table_lock); | |
241 | return sk; | |
242 | } | |
243 | ||
ea72912c | 244 | static inline struct hlist_head *nl_pid_hash_zalloc(size_t size) |
1da177e4 LT |
245 | { |
246 | if (size <= PAGE_SIZE) | |
ea72912c | 247 | return kzalloc(size, GFP_ATOMIC); |
1da177e4 LT |
248 | else |
249 | return (struct hlist_head *) | |
ea72912c ED |
250 | __get_free_pages(GFP_ATOMIC | __GFP_ZERO, |
251 | get_order(size)); | |
1da177e4 LT |
252 | } |
253 | ||
254 | static inline void nl_pid_hash_free(struct hlist_head *table, size_t size) | |
255 | { | |
256 | if (size <= PAGE_SIZE) | |
257 | kfree(table); | |
258 | else | |
259 | free_pages((unsigned long)table, get_order(size)); | |
260 | } | |
261 | ||
262 | static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow) | |
263 | { | |
264 | unsigned int omask, mask, shift; | |
265 | size_t osize, size; | |
266 | struct hlist_head *otable, *table; | |
267 | int i; | |
268 | ||
269 | omask = mask = hash->mask; | |
270 | osize = size = (mask + 1) * sizeof(*table); | |
271 | shift = hash->shift; | |
272 | ||
273 | if (grow) { | |
274 | if (++shift > hash->max_shift) | |
275 | return 0; | |
276 | mask = mask * 2 + 1; | |
277 | size *= 2; | |
278 | } | |
279 | ||
ea72912c | 280 | table = nl_pid_hash_zalloc(size); |
1da177e4 LT |
281 | if (!table) |
282 | return 0; | |
283 | ||
1da177e4 LT |
284 | otable = hash->table; |
285 | hash->table = table; | |
286 | hash->mask = mask; | |
287 | hash->shift = shift; | |
288 | get_random_bytes(&hash->rnd, sizeof(hash->rnd)); | |
289 | ||
290 | for (i = 0; i <= omask; i++) { | |
291 | struct sock *sk; | |
292 | struct hlist_node *node, *tmp; | |
293 | ||
294 | sk_for_each_safe(sk, node, tmp, &otable[i]) | |
295 | __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid)); | |
296 | } | |
297 | ||
298 | nl_pid_hash_free(otable, osize); | |
299 | hash->rehash_time = jiffies + 10 * 60 * HZ; | |
300 | return 1; | |
301 | } | |
302 | ||
303 | static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len) | |
304 | { | |
305 | int avg = hash->entries >> hash->shift; | |
306 | ||
307 | if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1)) | |
308 | return 1; | |
309 | ||
310 | if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) { | |
311 | nl_pid_hash_rehash(hash, 0); | |
312 | return 1; | |
313 | } | |
314 | ||
315 | return 0; | |
316 | } | |
317 | ||
90ddc4f0 | 318 | static const struct proto_ops netlink_ops; |
1da177e4 | 319 | |
4277a083 PM |
320 | static void |
321 | netlink_update_listeners(struct sock *sk) | |
322 | { | |
323 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
324 | struct hlist_node *node; | |
325 | unsigned long mask; | |
326 | unsigned int i; | |
327 | ||
b4ff4f04 | 328 | for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
4277a083 | 329 | mask = 0; |
b4ff4f04 JB |
330 | sk_for_each_bound(sk, node, &tbl->mc_list) { |
331 | if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) | |
332 | mask |= nlk_sk(sk)->groups[i]; | |
333 | } | |
4277a083 PM |
334 | tbl->listeners[i] = mask; |
335 | } | |
336 | /* this function is only called with the netlink table "grabbed", which | |
337 | * makes sure updates are visible before bind or setsockopt return. */ | |
338 | } | |
339 | ||
b4b51029 | 340 | static int netlink_insert(struct sock *sk, struct net *net, u32 pid) |
1da177e4 LT |
341 | { |
342 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; | |
343 | struct hlist_head *head; | |
344 | int err = -EADDRINUSE; | |
345 | struct sock *osk; | |
346 | struct hlist_node *node; | |
347 | int len; | |
348 | ||
349 | netlink_table_grab(); | |
350 | head = nl_pid_hashfn(hash, pid); | |
351 | len = 0; | |
352 | sk_for_each(osk, node, head) { | |
878628fb | 353 | if (net_eq(sock_net(osk), net) && (nlk_sk(osk)->pid == pid)) |
1da177e4 LT |
354 | break; |
355 | len++; | |
356 | } | |
357 | if (node) | |
358 | goto err; | |
359 | ||
360 | err = -EBUSY; | |
361 | if (nlk_sk(sk)->pid) | |
362 | goto err; | |
363 | ||
364 | err = -ENOMEM; | |
365 | if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX)) | |
366 | goto err; | |
367 | ||
368 | if (len && nl_pid_hash_dilute(hash, len)) | |
369 | head = nl_pid_hashfn(hash, pid); | |
370 | hash->entries++; | |
371 | nlk_sk(sk)->pid = pid; | |
372 | sk_add_node(sk, head); | |
373 | err = 0; | |
374 | ||
375 | err: | |
376 | netlink_table_ungrab(); | |
377 | return err; | |
378 | } | |
379 | ||
380 | static void netlink_remove(struct sock *sk) | |
381 | { | |
382 | netlink_table_grab(); | |
d470e3b4 DM |
383 | if (sk_del_node_init(sk)) |
384 | nl_table[sk->sk_protocol].hash.entries--; | |
f7fa9b10 | 385 | if (nlk_sk(sk)->subscriptions) |
1da177e4 LT |
386 | __sk_del_bind_node(sk); |
387 | netlink_table_ungrab(); | |
388 | } | |
389 | ||
390 | static struct proto netlink_proto = { | |
391 | .name = "NETLINK", | |
392 | .owner = THIS_MODULE, | |
393 | .obj_size = sizeof(struct netlink_sock), | |
394 | }; | |
395 | ||
1b8d7ae4 EB |
396 | static int __netlink_create(struct net *net, struct socket *sock, |
397 | struct mutex *cb_mutex, int protocol) | |
1da177e4 LT |
398 | { |
399 | struct sock *sk; | |
400 | struct netlink_sock *nlk; | |
ab33a171 PM |
401 | |
402 | sock->ops = &netlink_ops; | |
403 | ||
6257ff21 | 404 | sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto); |
ab33a171 PM |
405 | if (!sk) |
406 | return -ENOMEM; | |
407 | ||
408 | sock_init_data(sock, sk); | |
409 | ||
410 | nlk = nlk_sk(sk); | |
ffa4d721 PM |
411 | if (cb_mutex) |
412 | nlk->cb_mutex = cb_mutex; | |
413 | else { | |
414 | nlk->cb_mutex = &nlk->cb_def_mutex; | |
415 | mutex_init(nlk->cb_mutex); | |
416 | } | |
ab33a171 PM |
417 | init_waitqueue_head(&nlk->wait); |
418 | ||
419 | sk->sk_destruct = netlink_sock_destruct; | |
420 | sk->sk_protocol = protocol; | |
421 | return 0; | |
422 | } | |
423 | ||
1b8d7ae4 | 424 | static int netlink_create(struct net *net, struct socket *sock, int protocol) |
ab33a171 PM |
425 | { |
426 | struct module *module = NULL; | |
af65bdfc | 427 | struct mutex *cb_mutex; |
f7fa9b10 | 428 | struct netlink_sock *nlk; |
ab33a171 | 429 | int err = 0; |
1da177e4 LT |
430 | |
431 | sock->state = SS_UNCONNECTED; | |
432 | ||
433 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
434 | return -ESOCKTNOSUPPORT; | |
435 | ||
6ac552fd | 436 | if (protocol < 0 || protocol >= MAX_LINKS) |
1da177e4 LT |
437 | return -EPROTONOSUPPORT; |
438 | ||
77247bbb | 439 | netlink_lock_table(); |
95a5afca | 440 | #ifdef CONFIG_MODULES |
ab33a171 | 441 | if (!nl_table[protocol].registered) { |
77247bbb | 442 | netlink_unlock_table(); |
4fdb3bb7 | 443 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 444 | netlink_lock_table(); |
4fdb3bb7 | 445 | } |
ab33a171 PM |
446 | #endif |
447 | if (nl_table[protocol].registered && | |
448 | try_module_get(nl_table[protocol].module)) | |
449 | module = nl_table[protocol].module; | |
af65bdfc | 450 | cb_mutex = nl_table[protocol].cb_mutex; |
77247bbb | 451 | netlink_unlock_table(); |
4fdb3bb7 | 452 | |
6ac552fd PM |
453 | err = __netlink_create(net, sock, cb_mutex, protocol); |
454 | if (err < 0) | |
f7fa9b10 PM |
455 | goto out_module; |
456 | ||
6f756a8c | 457 | local_bh_disable(); |
c1fd3b94 | 458 | sock_prot_inuse_add(net, &netlink_proto, 1); |
6f756a8c DM |
459 | local_bh_enable(); |
460 | ||
f7fa9b10 | 461 | nlk = nlk_sk(sock->sk); |
f7fa9b10 | 462 | nlk->module = module; |
ab33a171 PM |
463 | out: |
464 | return err; | |
1da177e4 | 465 | |
ab33a171 PM |
466 | out_module: |
467 | module_put(module); | |
468 | goto out; | |
1da177e4 LT |
469 | } |
470 | ||
471 | static int netlink_release(struct socket *sock) | |
472 | { | |
473 | struct sock *sk = sock->sk; | |
474 | struct netlink_sock *nlk; | |
475 | ||
476 | if (!sk) | |
477 | return 0; | |
478 | ||
479 | netlink_remove(sk); | |
ac57b3a9 | 480 | sock_orphan(sk); |
1da177e4 LT |
481 | nlk = nlk_sk(sk); |
482 | ||
3f660d66 HX |
483 | /* |
484 | * OK. Socket is unlinked, any packets that arrive now | |
485 | * will be purged. | |
486 | */ | |
1da177e4 | 487 | |
1da177e4 LT |
488 | sock->sk = NULL; |
489 | wake_up_interruptible_all(&nlk->wait); | |
490 | ||
491 | skb_queue_purge(&sk->sk_write_queue); | |
492 | ||
f7fa9b10 | 493 | if (nlk->pid && !nlk->subscriptions) { |
1da177e4 | 494 | struct netlink_notify n = { |
3b1e0a65 | 495 | .net = sock_net(sk), |
1da177e4 LT |
496 | .protocol = sk->sk_protocol, |
497 | .pid = nlk->pid, | |
498 | }; | |
e041c683 AS |
499 | atomic_notifier_call_chain(&netlink_chain, |
500 | NETLINK_URELEASE, &n); | |
746fac4d | 501 | } |
4fdb3bb7 | 502 | |
5e7c001c | 503 | module_put(nlk->module); |
4fdb3bb7 | 504 | |
4277a083 | 505 | netlink_table_grab(); |
aed81560 | 506 | if (netlink_is_kernel(sk)) { |
869e58f8 DL |
507 | BUG_ON(nl_table[sk->sk_protocol].registered == 0); |
508 | if (--nl_table[sk->sk_protocol].registered == 0) { | |
509 | kfree(nl_table[sk->sk_protocol].listeners); | |
510 | nl_table[sk->sk_protocol].module = NULL; | |
511 | nl_table[sk->sk_protocol].registered = 0; | |
512 | } | |
4277a083 PM |
513 | } else if (nlk->subscriptions) |
514 | netlink_update_listeners(sk); | |
515 | netlink_table_ungrab(); | |
77247bbb | 516 | |
f7fa9b10 PM |
517 | kfree(nlk->groups); |
518 | nlk->groups = NULL; | |
519 | ||
3755810c | 520 | local_bh_disable(); |
c1fd3b94 | 521 | sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); |
3755810c | 522 | local_bh_enable(); |
1da177e4 LT |
523 | sock_put(sk); |
524 | return 0; | |
525 | } | |
526 | ||
527 | static int netlink_autobind(struct socket *sock) | |
528 | { | |
529 | struct sock *sk = sock->sk; | |
3b1e0a65 | 530 | struct net *net = sock_net(sk); |
1da177e4 LT |
531 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; |
532 | struct hlist_head *head; | |
533 | struct sock *osk; | |
534 | struct hlist_node *node; | |
c27bd492 | 535 | s32 pid = current->tgid; |
1da177e4 LT |
536 | int err; |
537 | static s32 rover = -4097; | |
538 | ||
539 | retry: | |
540 | cond_resched(); | |
541 | netlink_table_grab(); | |
542 | head = nl_pid_hashfn(hash, pid); | |
543 | sk_for_each(osk, node, head) { | |
878628fb | 544 | if (!net_eq(sock_net(osk), net)) |
b4b51029 | 545 | continue; |
1da177e4 LT |
546 | if (nlk_sk(osk)->pid == pid) { |
547 | /* Bind collision, search negative pid values. */ | |
548 | pid = rover--; | |
549 | if (rover > -4097) | |
550 | rover = -4097; | |
551 | netlink_table_ungrab(); | |
552 | goto retry; | |
553 | } | |
554 | } | |
555 | netlink_table_ungrab(); | |
556 | ||
b4b51029 | 557 | err = netlink_insert(sk, net, pid); |
1da177e4 LT |
558 | if (err == -EADDRINUSE) |
559 | goto retry; | |
d470e3b4 DM |
560 | |
561 | /* If 2 threads race to autobind, that is fine. */ | |
562 | if (err == -EBUSY) | |
563 | err = 0; | |
564 | ||
565 | return err; | |
1da177e4 LT |
566 | } |
567 | ||
746fac4d YH |
568 | static inline int netlink_capable(struct socket *sock, unsigned int flag) |
569 | { | |
1da177e4 LT |
570 | return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) || |
571 | capable(CAP_NET_ADMIN); | |
746fac4d | 572 | } |
1da177e4 | 573 | |
f7fa9b10 PM |
574 | static void |
575 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
576 | { | |
577 | struct netlink_sock *nlk = nlk_sk(sk); | |
578 | ||
579 | if (nlk->subscriptions && !subscriptions) | |
580 | __sk_del_bind_node(sk); | |
581 | else if (!nlk->subscriptions && subscriptions) | |
582 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
583 | nlk->subscriptions = subscriptions; | |
584 | } | |
585 | ||
b4ff4f04 | 586 | static int netlink_realloc_groups(struct sock *sk) |
513c2500 PM |
587 | { |
588 | struct netlink_sock *nlk = nlk_sk(sk); | |
589 | unsigned int groups; | |
b4ff4f04 | 590 | unsigned long *new_groups; |
513c2500 PM |
591 | int err = 0; |
592 | ||
b4ff4f04 JB |
593 | netlink_table_grab(); |
594 | ||
513c2500 | 595 | groups = nl_table[sk->sk_protocol].groups; |
b4ff4f04 | 596 | if (!nl_table[sk->sk_protocol].registered) { |
513c2500 | 597 | err = -ENOENT; |
b4ff4f04 JB |
598 | goto out_unlock; |
599 | } | |
513c2500 | 600 | |
b4ff4f04 JB |
601 | if (nlk->ngroups >= groups) |
602 | goto out_unlock; | |
513c2500 | 603 | |
b4ff4f04 JB |
604 | new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
605 | if (new_groups == NULL) { | |
606 | err = -ENOMEM; | |
607 | goto out_unlock; | |
608 | } | |
6ac552fd | 609 | memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, |
b4ff4f04 JB |
610 | NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); |
611 | ||
612 | nlk->groups = new_groups; | |
513c2500 | 613 | nlk->ngroups = groups; |
b4ff4f04 JB |
614 | out_unlock: |
615 | netlink_table_ungrab(); | |
616 | return err; | |
513c2500 PM |
617 | } |
618 | ||
6ac552fd PM |
619 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, |
620 | int addr_len) | |
1da177e4 LT |
621 | { |
622 | struct sock *sk = sock->sk; | |
3b1e0a65 | 623 | struct net *net = sock_net(sk); |
1da177e4 LT |
624 | struct netlink_sock *nlk = nlk_sk(sk); |
625 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
626 | int err; | |
746fac4d | 627 | |
1da177e4 LT |
628 | if (nladdr->nl_family != AF_NETLINK) |
629 | return -EINVAL; | |
630 | ||
631 | /* Only superuser is allowed to listen multicasts */ | |
513c2500 PM |
632 | if (nladdr->nl_groups) { |
633 | if (!netlink_capable(sock, NL_NONROOT_RECV)) | |
634 | return -EPERM; | |
b4ff4f04 JB |
635 | err = netlink_realloc_groups(sk); |
636 | if (err) | |
637 | return err; | |
513c2500 | 638 | } |
1da177e4 LT |
639 | |
640 | if (nlk->pid) { | |
641 | if (nladdr->nl_pid != nlk->pid) | |
642 | return -EINVAL; | |
643 | } else { | |
644 | err = nladdr->nl_pid ? | |
b4b51029 | 645 | netlink_insert(sk, net, nladdr->nl_pid) : |
1da177e4 LT |
646 | netlink_autobind(sock); |
647 | if (err) | |
648 | return err; | |
649 | } | |
650 | ||
513c2500 | 651 | if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
1da177e4 LT |
652 | return 0; |
653 | ||
654 | netlink_table_grab(); | |
f7fa9b10 | 655 | netlink_update_subscriptions(sk, nlk->subscriptions + |
746fac4d YH |
656 | hweight32(nladdr->nl_groups) - |
657 | hweight32(nlk->groups[0])); | |
658 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups; | |
4277a083 | 659 | netlink_update_listeners(sk); |
1da177e4 LT |
660 | netlink_table_ungrab(); |
661 | ||
662 | return 0; | |
663 | } | |
664 | ||
665 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
666 | int alen, int flags) | |
667 | { | |
668 | int err = 0; | |
669 | struct sock *sk = sock->sk; | |
670 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 671 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
1da177e4 LT |
672 | |
673 | if (addr->sa_family == AF_UNSPEC) { | |
674 | sk->sk_state = NETLINK_UNCONNECTED; | |
675 | nlk->dst_pid = 0; | |
d629b836 | 676 | nlk->dst_group = 0; |
1da177e4 LT |
677 | return 0; |
678 | } | |
679 | if (addr->sa_family != AF_NETLINK) | |
680 | return -EINVAL; | |
681 | ||
682 | /* Only superuser is allowed to send multicasts */ | |
683 | if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND)) | |
684 | return -EPERM; | |
685 | ||
686 | if (!nlk->pid) | |
687 | err = netlink_autobind(sock); | |
688 | ||
689 | if (err == 0) { | |
690 | sk->sk_state = NETLINK_CONNECTED; | |
691 | nlk->dst_pid = nladdr->nl_pid; | |
d629b836 | 692 | nlk->dst_group = ffs(nladdr->nl_groups); |
1da177e4 LT |
693 | } |
694 | ||
695 | return err; | |
696 | } | |
697 | ||
6ac552fd PM |
698 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, |
699 | int *addr_len, int peer) | |
1da177e4 LT |
700 | { |
701 | struct sock *sk = sock->sk; | |
702 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 703 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
746fac4d | 704 | |
1da177e4 LT |
705 | nladdr->nl_family = AF_NETLINK; |
706 | nladdr->nl_pad = 0; | |
707 | *addr_len = sizeof(*nladdr); | |
708 | ||
709 | if (peer) { | |
710 | nladdr->nl_pid = nlk->dst_pid; | |
d629b836 | 711 | nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
1da177e4 LT |
712 | } else { |
713 | nladdr->nl_pid = nlk->pid; | |
513c2500 | 714 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
1da177e4 LT |
715 | } |
716 | return 0; | |
717 | } | |
718 | ||
719 | static void netlink_overrun(struct sock *sk) | |
720 | { | |
38938bfe PNA |
721 | struct netlink_sock *nlk = nlk_sk(sk); |
722 | ||
723 | if (!(nlk->flags & NETLINK_RECV_NO_ENOBUFS)) { | |
724 | if (!test_and_set_bit(0, &nlk_sk(sk)->state)) { | |
725 | sk->sk_err = ENOBUFS; | |
726 | sk->sk_error_report(sk); | |
727 | } | |
1da177e4 | 728 | } |
38938bfe | 729 | atomic_inc(&sk->sk_drops); |
1da177e4 LT |
730 | } |
731 | ||
732 | static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid) | |
733 | { | |
1da177e4 LT |
734 | struct sock *sock; |
735 | struct netlink_sock *nlk; | |
736 | ||
3b1e0a65 | 737 | sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, pid); |
1da177e4 LT |
738 | if (!sock) |
739 | return ERR_PTR(-ECONNREFUSED); | |
740 | ||
741 | /* Don't bother queuing skb if kernel socket has no input function */ | |
742 | nlk = nlk_sk(sock); | |
cd40b7d3 DL |
743 | if (sock->sk_state == NETLINK_CONNECTED && |
744 | nlk->dst_pid != nlk_sk(ssk)->pid) { | |
1da177e4 LT |
745 | sock_put(sock); |
746 | return ERR_PTR(-ECONNREFUSED); | |
747 | } | |
748 | return sock; | |
749 | } | |
750 | ||
751 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
752 | { | |
6db5fc5d | 753 | struct inode *inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
754 | struct sock *sock; |
755 | ||
756 | if (!S_ISSOCK(inode->i_mode)) | |
757 | return ERR_PTR(-ENOTSOCK); | |
758 | ||
759 | sock = SOCKET_I(inode)->sk; | |
760 | if (sock->sk_family != AF_NETLINK) | |
761 | return ERR_PTR(-EINVAL); | |
762 | ||
763 | sock_hold(sock); | |
764 | return sock; | |
765 | } | |
766 | ||
767 | /* | |
768 | * Attach a skb to a netlink socket. | |
769 | * The caller must hold a reference to the destination socket. On error, the | |
770 | * reference is dropped. The skb is not send to the destination, just all | |
771 | * all error checks are performed and memory in the queue is reserved. | |
772 | * Return values: | |
773 | * < 0: error. skb freed, reference to sock dropped. | |
774 | * 0: continue | |
775 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
776 | */ | |
9457afee | 777 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
c3d8d1e3 | 778 | long *timeo, struct sock *ssk) |
1da177e4 LT |
779 | { |
780 | struct netlink_sock *nlk; | |
781 | ||
782 | nlk = nlk_sk(sk); | |
783 | ||
784 | if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
785 | test_bit(0, &nlk->state)) { | |
786 | DECLARE_WAITQUEUE(wait, current); | |
c3d8d1e3 | 787 | if (!*timeo) { |
aed81560 | 788 | if (!ssk || netlink_is_kernel(ssk)) |
1da177e4 LT |
789 | netlink_overrun(sk); |
790 | sock_put(sk); | |
791 | kfree_skb(skb); | |
792 | return -EAGAIN; | |
793 | } | |
794 | ||
795 | __set_current_state(TASK_INTERRUPTIBLE); | |
796 | add_wait_queue(&nlk->wait, &wait); | |
797 | ||
798 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
799 | test_bit(0, &nlk->state)) && | |
800 | !sock_flag(sk, SOCK_DEAD)) | |
c3d8d1e3 | 801 | *timeo = schedule_timeout(*timeo); |
1da177e4 LT |
802 | |
803 | __set_current_state(TASK_RUNNING); | |
804 | remove_wait_queue(&nlk->wait, &wait); | |
805 | sock_put(sk); | |
806 | ||
807 | if (signal_pending(current)) { | |
808 | kfree_skb(skb); | |
c3d8d1e3 | 809 | return sock_intr_errno(*timeo); |
1da177e4 LT |
810 | } |
811 | return 1; | |
812 | } | |
813 | skb_set_owner_r(skb, sk); | |
814 | return 0; | |
815 | } | |
816 | ||
7ee015e0 | 817 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 818 | { |
1da177e4 LT |
819 | int len = skb->len; |
820 | ||
1da177e4 LT |
821 | skb_queue_tail(&sk->sk_receive_queue, skb); |
822 | sk->sk_data_ready(sk, len); | |
823 | sock_put(sk); | |
824 | return len; | |
825 | } | |
826 | ||
827 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
828 | { | |
829 | kfree_skb(skb); | |
830 | sock_put(sk); | |
831 | } | |
832 | ||
37da647d | 833 | static inline struct sk_buff *netlink_trim(struct sk_buff *skb, |
dd0fc66f | 834 | gfp_t allocation) |
1da177e4 LT |
835 | { |
836 | int delta; | |
837 | ||
838 | skb_orphan(skb); | |
839 | ||
4305b541 | 840 | delta = skb->end - skb->tail; |
1da177e4 LT |
841 | if (delta * 2 < skb->truesize) |
842 | return skb; | |
843 | ||
844 | if (skb_shared(skb)) { | |
845 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
846 | if (!nskb) | |
847 | return skb; | |
848 | kfree_skb(skb); | |
849 | skb = nskb; | |
850 | } | |
851 | ||
852 | if (!pskb_expand_head(skb, 0, -delta, allocation)) | |
853 | skb->truesize -= delta; | |
854 | ||
855 | return skb; | |
856 | } | |
857 | ||
cd40b7d3 DL |
858 | static inline void netlink_rcv_wake(struct sock *sk) |
859 | { | |
860 | struct netlink_sock *nlk = nlk_sk(sk); | |
861 | ||
862 | if (skb_queue_empty(&sk->sk_receive_queue)) | |
863 | clear_bit(0, &nlk->state); | |
864 | if (!test_bit(0, &nlk->state)) | |
865 | wake_up_interruptible(&nlk->wait); | |
866 | } | |
867 | ||
868 | static inline int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb) | |
869 | { | |
870 | int ret; | |
871 | struct netlink_sock *nlk = nlk_sk(sk); | |
872 | ||
873 | ret = -ECONNREFUSED; | |
874 | if (nlk->netlink_rcv != NULL) { | |
875 | ret = skb->len; | |
876 | skb_set_owner_r(skb, sk); | |
877 | nlk->netlink_rcv(skb); | |
878 | } | |
879 | kfree_skb(skb); | |
880 | sock_put(sk); | |
881 | return ret; | |
882 | } | |
883 | ||
884 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, | |
885 | u32 pid, int nonblock) | |
1da177e4 LT |
886 | { |
887 | struct sock *sk; | |
888 | int err; | |
889 | long timeo; | |
890 | ||
891 | skb = netlink_trim(skb, gfp_any()); | |
892 | ||
893 | timeo = sock_sndtimeo(ssk, nonblock); | |
894 | retry: | |
895 | sk = netlink_getsockbypid(ssk, pid); | |
896 | if (IS_ERR(sk)) { | |
897 | kfree_skb(skb); | |
898 | return PTR_ERR(sk); | |
899 | } | |
cd40b7d3 DL |
900 | if (netlink_is_kernel(sk)) |
901 | return netlink_unicast_kernel(sk, skb); | |
902 | ||
b1153f29 | 903 | if (sk_filter(sk, skb)) { |
84874607 | 904 | err = skb->len; |
b1153f29 SH |
905 | kfree_skb(skb); |
906 | sock_put(sk); | |
907 | return err; | |
908 | } | |
909 | ||
9457afee | 910 | err = netlink_attachskb(sk, skb, &timeo, ssk); |
1da177e4 LT |
911 | if (err == 1) |
912 | goto retry; | |
913 | if (err) | |
914 | return err; | |
915 | ||
7ee015e0 | 916 | return netlink_sendskb(sk, skb); |
1da177e4 | 917 | } |
6ac552fd | 918 | EXPORT_SYMBOL(netlink_unicast); |
1da177e4 | 919 | |
4277a083 PM |
920 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
921 | { | |
922 | int res = 0; | |
b4ff4f04 | 923 | unsigned long *listeners; |
4277a083 | 924 | |
aed81560 | 925 | BUG_ON(!netlink_is_kernel(sk)); |
b4ff4f04 JB |
926 | |
927 | rcu_read_lock(); | |
928 | listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); | |
929 | ||
4277a083 | 930 | if (group - 1 < nl_table[sk->sk_protocol].groups) |
b4ff4f04 JB |
931 | res = test_bit(group - 1, listeners); |
932 | ||
933 | rcu_read_unlock(); | |
934 | ||
4277a083 PM |
935 | return res; |
936 | } | |
937 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
938 | ||
6ac552fd PM |
939 | static inline int netlink_broadcast_deliver(struct sock *sk, |
940 | struct sk_buff *skb) | |
1da177e4 LT |
941 | { |
942 | struct netlink_sock *nlk = nlk_sk(sk); | |
943 | ||
944 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
945 | !test_bit(0, &nlk->state)) { | |
946 | skb_set_owner_r(skb, sk); | |
947 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
948 | sk->sk_data_ready(sk, skb->len); | |
949 | return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf; | |
950 | } | |
951 | return -1; | |
952 | } | |
953 | ||
954 | struct netlink_broadcast_data { | |
955 | struct sock *exclude_sk; | |
b4b51029 | 956 | struct net *net; |
1da177e4 LT |
957 | u32 pid; |
958 | u32 group; | |
959 | int failure; | |
ff491a73 | 960 | int delivery_failure; |
1da177e4 LT |
961 | int congested; |
962 | int delivered; | |
7d877f3b | 963 | gfp_t allocation; |
1da177e4 LT |
964 | struct sk_buff *skb, *skb2; |
965 | }; | |
966 | ||
967 | static inline int do_one_broadcast(struct sock *sk, | |
968 | struct netlink_broadcast_data *p) | |
969 | { | |
970 | struct netlink_sock *nlk = nlk_sk(sk); | |
971 | int val; | |
972 | ||
973 | if (p->exclude_sk == sk) | |
974 | goto out; | |
975 | ||
f7fa9b10 PM |
976 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
977 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
978 | goto out; |
979 | ||
878628fb | 980 | if (!net_eq(sock_net(sk), p->net)) |
b4b51029 EB |
981 | goto out; |
982 | ||
1da177e4 LT |
983 | if (p->failure) { |
984 | netlink_overrun(sk); | |
985 | goto out; | |
986 | } | |
987 | ||
988 | sock_hold(sk); | |
989 | if (p->skb2 == NULL) { | |
68acc024 | 990 | if (skb_shared(p->skb)) { |
1da177e4 LT |
991 | p->skb2 = skb_clone(p->skb, p->allocation); |
992 | } else { | |
68acc024 TC |
993 | p->skb2 = skb_get(p->skb); |
994 | /* | |
995 | * skb ownership may have been set when | |
996 | * delivered to a previous socket. | |
997 | */ | |
998 | skb_orphan(p->skb2); | |
1da177e4 LT |
999 | } |
1000 | } | |
1001 | if (p->skb2 == NULL) { | |
1002 | netlink_overrun(sk); | |
1003 | /* Clone failed. Notify ALL listeners. */ | |
1004 | p->failure = 1; | |
be0c22a4 PNA |
1005 | if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) |
1006 | p->delivery_failure = 1; | |
b1153f29 SH |
1007 | } else if (sk_filter(sk, p->skb2)) { |
1008 | kfree_skb(p->skb2); | |
1009 | p->skb2 = NULL; | |
1da177e4 LT |
1010 | } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) { |
1011 | netlink_overrun(sk); | |
be0c22a4 PNA |
1012 | if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) |
1013 | p->delivery_failure = 1; | |
1da177e4 LT |
1014 | } else { |
1015 | p->congested |= val; | |
1016 | p->delivered = 1; | |
1017 | p->skb2 = NULL; | |
1018 | } | |
1019 | sock_put(sk); | |
1020 | ||
1021 | out: | |
1022 | return 0; | |
1023 | } | |
1024 | ||
1025 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid, | |
dd0fc66f | 1026 | u32 group, gfp_t allocation) |
1da177e4 | 1027 | { |
3b1e0a65 | 1028 | struct net *net = sock_net(ssk); |
1da177e4 LT |
1029 | struct netlink_broadcast_data info; |
1030 | struct hlist_node *node; | |
1031 | struct sock *sk; | |
1032 | ||
1033 | skb = netlink_trim(skb, allocation); | |
1034 | ||
1035 | info.exclude_sk = ssk; | |
b4b51029 | 1036 | info.net = net; |
1da177e4 LT |
1037 | info.pid = pid; |
1038 | info.group = group; | |
1039 | info.failure = 0; | |
ff491a73 | 1040 | info.delivery_failure = 0; |
1da177e4 LT |
1041 | info.congested = 0; |
1042 | info.delivered = 0; | |
1043 | info.allocation = allocation; | |
1044 | info.skb = skb; | |
1045 | info.skb2 = NULL; | |
1046 | ||
1047 | /* While we sleep in clone, do not allow to change socket list */ | |
1048 | ||
1049 | netlink_lock_table(); | |
1050 | ||
1051 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1052 | do_one_broadcast(sk, &info); | |
1053 | ||
aa1c6a6f TC |
1054 | kfree_skb(skb); |
1055 | ||
1da177e4 LT |
1056 | netlink_unlock_table(); |
1057 | ||
91744f65 | 1058 | kfree_skb(info.skb2); |
1da177e4 | 1059 | |
be0c22a4 | 1060 | if (info.delivery_failure) |
ff491a73 PNA |
1061 | return -ENOBUFS; |
1062 | ||
1da177e4 LT |
1063 | if (info.delivered) { |
1064 | if (info.congested && (allocation & __GFP_WAIT)) | |
1065 | yield(); | |
1066 | return 0; | |
1067 | } | |
1da177e4 LT |
1068 | return -ESRCH; |
1069 | } | |
6ac552fd | 1070 | EXPORT_SYMBOL(netlink_broadcast); |
1da177e4 LT |
1071 | |
1072 | struct netlink_set_err_data { | |
1073 | struct sock *exclude_sk; | |
1074 | u32 pid; | |
1075 | u32 group; | |
1076 | int code; | |
1077 | }; | |
1078 | ||
1079 | static inline int do_one_set_err(struct sock *sk, | |
1080 | struct netlink_set_err_data *p) | |
1081 | { | |
1082 | struct netlink_sock *nlk = nlk_sk(sk); | |
1083 | ||
1084 | if (sk == p->exclude_sk) | |
1085 | goto out; | |
1086 | ||
3b1e0a65 | 1087 | if (sock_net(sk) != sock_net(p->exclude_sk)) |
b4b51029 EB |
1088 | goto out; |
1089 | ||
f7fa9b10 PM |
1090 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
1091 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
1092 | goto out; |
1093 | ||
1094 | sk->sk_err = p->code; | |
1095 | sk->sk_error_report(sk); | |
1096 | out: | |
1097 | return 0; | |
1098 | } | |
1099 | ||
4843b93c PNA |
1100 | /** |
1101 | * netlink_set_err - report error to broadcast listeners | |
1102 | * @ssk: the kernel netlink socket, as returned by netlink_kernel_create() | |
1103 | * @pid: the PID of a process that we want to skip (if any) | |
1104 | * @groups: the broadcast group that will notice the error | |
1105 | * @code: error code, must be negative (as usual in kernelspace) | |
1106 | */ | |
1da177e4 LT |
1107 | void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) |
1108 | { | |
1109 | struct netlink_set_err_data info; | |
1110 | struct hlist_node *node; | |
1111 | struct sock *sk; | |
1112 | ||
1113 | info.exclude_sk = ssk; | |
1114 | info.pid = pid; | |
1115 | info.group = group; | |
4843b93c PNA |
1116 | /* sk->sk_err wants a positive error value */ |
1117 | info.code = -code; | |
1da177e4 LT |
1118 | |
1119 | read_lock(&nl_table_lock); | |
1120 | ||
1121 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1122 | do_one_set_err(sk, &info); | |
1123 | ||
1124 | read_unlock(&nl_table_lock); | |
1125 | } | |
dd5b6ce6 | 1126 | EXPORT_SYMBOL(netlink_set_err); |
1da177e4 | 1127 | |
84659eb5 JB |
1128 | /* must be called with netlink table grabbed */ |
1129 | static void netlink_update_socket_mc(struct netlink_sock *nlk, | |
1130 | unsigned int group, | |
1131 | int is_new) | |
1132 | { | |
1133 | int old, new = !!is_new, subscriptions; | |
1134 | ||
1135 | old = test_bit(group - 1, nlk->groups); | |
1136 | subscriptions = nlk->subscriptions - old + new; | |
1137 | if (new) | |
1138 | __set_bit(group - 1, nlk->groups); | |
1139 | else | |
1140 | __clear_bit(group - 1, nlk->groups); | |
1141 | netlink_update_subscriptions(&nlk->sk, subscriptions); | |
1142 | netlink_update_listeners(&nlk->sk); | |
1143 | } | |
1144 | ||
9a4595bc | 1145 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
746fac4d | 1146 | char __user *optval, int optlen) |
9a4595bc PM |
1147 | { |
1148 | struct sock *sk = sock->sk; | |
1149 | struct netlink_sock *nlk = nlk_sk(sk); | |
eb496534 JB |
1150 | unsigned int val = 0; |
1151 | int err; | |
9a4595bc PM |
1152 | |
1153 | if (level != SOL_NETLINK) | |
1154 | return -ENOPROTOOPT; | |
1155 | ||
1156 | if (optlen >= sizeof(int) && | |
eb496534 | 1157 | get_user(val, (unsigned int __user *)optval)) |
9a4595bc PM |
1158 | return -EFAULT; |
1159 | ||
1160 | switch (optname) { | |
1161 | case NETLINK_PKTINFO: | |
1162 | if (val) | |
1163 | nlk->flags |= NETLINK_RECV_PKTINFO; | |
1164 | else | |
1165 | nlk->flags &= ~NETLINK_RECV_PKTINFO; | |
1166 | err = 0; | |
1167 | break; | |
1168 | case NETLINK_ADD_MEMBERSHIP: | |
1169 | case NETLINK_DROP_MEMBERSHIP: { | |
9a4595bc PM |
1170 | if (!netlink_capable(sock, NL_NONROOT_RECV)) |
1171 | return -EPERM; | |
b4ff4f04 JB |
1172 | err = netlink_realloc_groups(sk); |
1173 | if (err) | |
1174 | return err; | |
9a4595bc PM |
1175 | if (!val || val - 1 >= nlk->ngroups) |
1176 | return -EINVAL; | |
1177 | netlink_table_grab(); | |
84659eb5 JB |
1178 | netlink_update_socket_mc(nlk, val, |
1179 | optname == NETLINK_ADD_MEMBERSHIP); | |
9a4595bc PM |
1180 | netlink_table_ungrab(); |
1181 | err = 0; | |
1182 | break; | |
1183 | } | |
be0c22a4 PNA |
1184 | case NETLINK_BROADCAST_ERROR: |
1185 | if (val) | |
1186 | nlk->flags |= NETLINK_BROADCAST_SEND_ERROR; | |
1187 | else | |
1188 | nlk->flags &= ~NETLINK_BROADCAST_SEND_ERROR; | |
1189 | err = 0; | |
1190 | break; | |
38938bfe PNA |
1191 | case NETLINK_NO_ENOBUFS: |
1192 | if (val) { | |
1193 | nlk->flags |= NETLINK_RECV_NO_ENOBUFS; | |
1194 | clear_bit(0, &nlk->state); | |
1195 | wake_up_interruptible(&nlk->wait); | |
1196 | } else | |
1197 | nlk->flags &= ~NETLINK_RECV_NO_ENOBUFS; | |
1198 | err = 0; | |
1199 | break; | |
9a4595bc PM |
1200 | default: |
1201 | err = -ENOPROTOOPT; | |
1202 | } | |
1203 | return err; | |
1204 | } | |
1205 | ||
1206 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
746fac4d | 1207 | char __user *optval, int __user *optlen) |
9a4595bc PM |
1208 | { |
1209 | struct sock *sk = sock->sk; | |
1210 | struct netlink_sock *nlk = nlk_sk(sk); | |
1211 | int len, val, err; | |
1212 | ||
1213 | if (level != SOL_NETLINK) | |
1214 | return -ENOPROTOOPT; | |
1215 | ||
1216 | if (get_user(len, optlen)) | |
1217 | return -EFAULT; | |
1218 | if (len < 0) | |
1219 | return -EINVAL; | |
1220 | ||
1221 | switch (optname) { | |
1222 | case NETLINK_PKTINFO: | |
1223 | if (len < sizeof(int)) | |
1224 | return -EINVAL; | |
1225 | len = sizeof(int); | |
1226 | val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0; | |
a27b58fe HC |
1227 | if (put_user(len, optlen) || |
1228 | put_user(val, optval)) | |
1229 | return -EFAULT; | |
9a4595bc PM |
1230 | err = 0; |
1231 | break; | |
be0c22a4 PNA |
1232 | case NETLINK_BROADCAST_ERROR: |
1233 | if (len < sizeof(int)) | |
1234 | return -EINVAL; | |
1235 | len = sizeof(int); | |
1236 | val = nlk->flags & NETLINK_BROADCAST_SEND_ERROR ? 1 : 0; | |
1237 | if (put_user(len, optlen) || | |
1238 | put_user(val, optval)) | |
1239 | return -EFAULT; | |
1240 | err = 0; | |
1241 | break; | |
38938bfe PNA |
1242 | case NETLINK_NO_ENOBUFS: |
1243 | if (len < sizeof(int)) | |
1244 | return -EINVAL; | |
1245 | len = sizeof(int); | |
1246 | val = nlk->flags & NETLINK_RECV_NO_ENOBUFS ? 1 : 0; | |
1247 | if (put_user(len, optlen) || | |
1248 | put_user(val, optval)) | |
1249 | return -EFAULT; | |
1250 | err = 0; | |
1251 | break; | |
9a4595bc PM |
1252 | default: |
1253 | err = -ENOPROTOOPT; | |
1254 | } | |
1255 | return err; | |
1256 | } | |
1257 | ||
1258 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
1259 | { | |
1260 | struct nl_pktinfo info; | |
1261 | ||
1262 | info.group = NETLINK_CB(skb).dst_group; | |
1263 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
1264 | } | |
1265 | ||
1da177e4 LT |
1266 | static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, |
1267 | struct msghdr *msg, size_t len) | |
1268 | { | |
1269 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1270 | struct sock *sk = sock->sk; | |
1271 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 1272 | struct sockaddr_nl *addr = msg->msg_name; |
1da177e4 | 1273 | u32 dst_pid; |
d629b836 | 1274 | u32 dst_group; |
1da177e4 LT |
1275 | struct sk_buff *skb; |
1276 | int err; | |
1277 | struct scm_cookie scm; | |
1278 | ||
1279 | if (msg->msg_flags&MSG_OOB) | |
1280 | return -EOPNOTSUPP; | |
1281 | ||
1282 | if (NULL == siocb->scm) | |
1283 | siocb->scm = &scm; | |
1284 | err = scm_send(sock, msg, siocb->scm); | |
1285 | if (err < 0) | |
1286 | return err; | |
1287 | ||
1288 | if (msg->msg_namelen) { | |
1289 | if (addr->nl_family != AF_NETLINK) | |
1290 | return -EINVAL; | |
1291 | dst_pid = addr->nl_pid; | |
d629b836 PM |
1292 | dst_group = ffs(addr->nl_groups); |
1293 | if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND)) | |
1da177e4 LT |
1294 | return -EPERM; |
1295 | } else { | |
1296 | dst_pid = nlk->dst_pid; | |
d629b836 | 1297 | dst_group = nlk->dst_group; |
1da177e4 LT |
1298 | } |
1299 | ||
1300 | if (!nlk->pid) { | |
1301 | err = netlink_autobind(sock); | |
1302 | if (err) | |
1303 | goto out; | |
1304 | } | |
1305 | ||
1306 | err = -EMSGSIZE; | |
1307 | if (len > sk->sk_sndbuf - 32) | |
1308 | goto out; | |
1309 | err = -ENOBUFS; | |
339bf98f | 1310 | skb = alloc_skb(len, GFP_KERNEL); |
6ac552fd | 1311 | if (skb == NULL) |
1da177e4 LT |
1312 | goto out; |
1313 | ||
1314 | NETLINK_CB(skb).pid = nlk->pid; | |
d629b836 | 1315 | NETLINK_CB(skb).dst_group = dst_group; |
0c11b942 | 1316 | NETLINK_CB(skb).loginuid = audit_get_loginuid(current); |
2532386f | 1317 | NETLINK_CB(skb).sessionid = audit_get_sessionid(current); |
0ce784ca | 1318 | security_task_getsecid(current, &(NETLINK_CB(skb).sid)); |
1da177e4 LT |
1319 | memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); |
1320 | ||
1321 | /* What can I do? Netlink is asynchronous, so that | |
1322 | we will have to save current capabilities to | |
1323 | check them, when this message will be delivered | |
1324 | to corresponding kernel module. --ANK (980802) | |
1325 | */ | |
1326 | ||
1327 | err = -EFAULT; | |
6ac552fd | 1328 | if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) { |
1da177e4 LT |
1329 | kfree_skb(skb); |
1330 | goto out; | |
1331 | } | |
1332 | ||
1333 | err = security_netlink_send(sk, skb); | |
1334 | if (err) { | |
1335 | kfree_skb(skb); | |
1336 | goto out; | |
1337 | } | |
1338 | ||
d629b836 | 1339 | if (dst_group) { |
1da177e4 | 1340 | atomic_inc(&skb->users); |
d629b836 | 1341 | netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL); |
1da177e4 LT |
1342 | } |
1343 | err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT); | |
1344 | ||
1345 | out: | |
1346 | return err; | |
1347 | } | |
1348 | ||
1349 | static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, | |
1350 | struct msghdr *msg, size_t len, | |
1351 | int flags) | |
1352 | { | |
1353 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1354 | struct scm_cookie scm; | |
1355 | struct sock *sk = sock->sk; | |
1356 | struct netlink_sock *nlk = nlk_sk(sk); | |
1357 | int noblock = flags&MSG_DONTWAIT; | |
1358 | size_t copied; | |
1359 | struct sk_buff *skb; | |
1360 | int err; | |
1361 | ||
1362 | if (flags&MSG_OOB) | |
1363 | return -EOPNOTSUPP; | |
1364 | ||
1365 | copied = 0; | |
1366 | ||
6ac552fd PM |
1367 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
1368 | if (skb == NULL) | |
1da177e4 LT |
1369 | goto out; |
1370 | ||
1371 | msg->msg_namelen = 0; | |
1372 | ||
1373 | copied = skb->len; | |
1374 | if (len < copied) { | |
1375 | msg->msg_flags |= MSG_TRUNC; | |
1376 | copied = len; | |
1377 | } | |
1378 | ||
badff6d0 | 1379 | skb_reset_transport_header(skb); |
1da177e4 LT |
1380 | err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); |
1381 | ||
1382 | if (msg->msg_name) { | |
6ac552fd | 1383 | struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name; |
1da177e4 LT |
1384 | addr->nl_family = AF_NETLINK; |
1385 | addr->nl_pad = 0; | |
1386 | addr->nl_pid = NETLINK_CB(skb).pid; | |
d629b836 | 1387 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
1388 | msg->msg_namelen = sizeof(*addr); |
1389 | } | |
1390 | ||
cc9a06cd PM |
1391 | if (nlk->flags & NETLINK_RECV_PKTINFO) |
1392 | netlink_cmsg_recv_pktinfo(msg, skb); | |
1393 | ||
1da177e4 LT |
1394 | if (NULL == siocb->scm) { |
1395 | memset(&scm, 0, sizeof(scm)); | |
1396 | siocb->scm = &scm; | |
1397 | } | |
1398 | siocb->scm->creds = *NETLINK_CREDS(skb); | |
188ccb55 PM |
1399 | if (flags & MSG_TRUNC) |
1400 | copied = skb->len; | |
1da177e4 LT |
1401 | skb_free_datagram(sk, skb); |
1402 | ||
1403 | if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) | |
1404 | netlink_dump(sk); | |
1405 | ||
1406 | scm_recv(sock, msg, siocb->scm, flags); | |
1da177e4 LT |
1407 | out: |
1408 | netlink_rcv_wake(sk); | |
1409 | return err ? : copied; | |
1410 | } | |
1411 | ||
1412 | static void netlink_data_ready(struct sock *sk, int len) | |
1413 | { | |
cd40b7d3 | 1414 | BUG(); |
1da177e4 LT |
1415 | } |
1416 | ||
1417 | /* | |
746fac4d | 1418 | * We export these functions to other modules. They provide a |
1da177e4 LT |
1419 | * complete set of kernel non-blocking support for message |
1420 | * queueing. | |
1421 | */ | |
1422 | ||
1423 | struct sock * | |
b4b51029 | 1424 | netlink_kernel_create(struct net *net, int unit, unsigned int groups, |
cd40b7d3 | 1425 | void (*input)(struct sk_buff *skb), |
af65bdfc | 1426 | struct mutex *cb_mutex, struct module *module) |
1da177e4 LT |
1427 | { |
1428 | struct socket *sock; | |
1429 | struct sock *sk; | |
77247bbb | 1430 | struct netlink_sock *nlk; |
4277a083 | 1431 | unsigned long *listeners = NULL; |
1da177e4 | 1432 | |
fab2caf6 | 1433 | BUG_ON(!nl_table); |
1da177e4 | 1434 | |
6ac552fd | 1435 | if (unit < 0 || unit >= MAX_LINKS) |
1da177e4 LT |
1436 | return NULL; |
1437 | ||
1438 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
1439 | return NULL; | |
1440 | ||
23fe1866 PE |
1441 | /* |
1442 | * We have to just have a reference on the net from sk, but don't | |
1443 | * get_net it. Besides, we cannot get and then put the net here. | |
1444 | * So we create one inside init_net and the move it to net. | |
1445 | */ | |
1446 | ||
1447 | if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0) | |
1448 | goto out_sock_release_nosk; | |
1449 | ||
1450 | sk = sock->sk; | |
edf02087 | 1451 | sk_change_net(sk, net); |
4fdb3bb7 | 1452 | |
4277a083 PM |
1453 | if (groups < 32) |
1454 | groups = 32; | |
1455 | ||
1456 | listeners = kzalloc(NLGRPSZ(groups), GFP_KERNEL); | |
1457 | if (!listeners) | |
1458 | goto out_sock_release; | |
1459 | ||
1da177e4 LT |
1460 | sk->sk_data_ready = netlink_data_ready; |
1461 | if (input) | |
cd40b7d3 | 1462 | nlk_sk(sk)->netlink_rcv = input; |
1da177e4 | 1463 | |
b4b51029 | 1464 | if (netlink_insert(sk, net, 0)) |
77247bbb | 1465 | goto out_sock_release; |
4fdb3bb7 | 1466 | |
77247bbb PM |
1467 | nlk = nlk_sk(sk); |
1468 | nlk->flags |= NETLINK_KERNEL_SOCKET; | |
4fdb3bb7 | 1469 | |
4fdb3bb7 | 1470 | netlink_table_grab(); |
b4b51029 EB |
1471 | if (!nl_table[unit].registered) { |
1472 | nl_table[unit].groups = groups; | |
1473 | nl_table[unit].listeners = listeners; | |
1474 | nl_table[unit].cb_mutex = cb_mutex; | |
1475 | nl_table[unit].module = module; | |
1476 | nl_table[unit].registered = 1; | |
f937f1f4 JJ |
1477 | } else { |
1478 | kfree(listeners); | |
869e58f8 | 1479 | nl_table[unit].registered++; |
b4b51029 | 1480 | } |
4fdb3bb7 | 1481 | netlink_table_ungrab(); |
77247bbb PM |
1482 | return sk; |
1483 | ||
4fdb3bb7 | 1484 | out_sock_release: |
4277a083 | 1485 | kfree(listeners); |
9dfbec1f | 1486 | netlink_kernel_release(sk); |
23fe1866 PE |
1487 | return NULL; |
1488 | ||
1489 | out_sock_release_nosk: | |
4fdb3bb7 | 1490 | sock_release(sock); |
77247bbb | 1491 | return NULL; |
1da177e4 | 1492 | } |
6ac552fd | 1493 | EXPORT_SYMBOL(netlink_kernel_create); |
1da177e4 | 1494 | |
b7c6ba6e DL |
1495 | |
1496 | void | |
1497 | netlink_kernel_release(struct sock *sk) | |
1498 | { | |
edf02087 | 1499 | sk_release_kernel(sk); |
b7c6ba6e DL |
1500 | } |
1501 | EXPORT_SYMBOL(netlink_kernel_release); | |
1502 | ||
1503 | ||
b4ff4f04 JB |
1504 | /** |
1505 | * netlink_change_ngroups - change number of multicast groups | |
1506 | * | |
1507 | * This changes the number of multicast groups that are available | |
1508 | * on a certain netlink family. Note that it is not possible to | |
84659eb5 JB |
1509 | * change the number of groups to below 32. Also note that it does |
1510 | * not implicitly call netlink_clear_multicast_users() when the | |
1511 | * number of groups is reduced. | |
b4ff4f04 JB |
1512 | * |
1513 | * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). | |
1514 | * @groups: The new number of groups. | |
1515 | */ | |
1516 | int netlink_change_ngroups(struct sock *sk, unsigned int groups) | |
1517 | { | |
1518 | unsigned long *listeners, *old = NULL; | |
1519 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
1520 | int err = 0; | |
1521 | ||
1522 | if (groups < 32) | |
1523 | groups = 32; | |
1524 | ||
1525 | netlink_table_grab(); | |
1526 | if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { | |
1527 | listeners = kzalloc(NLGRPSZ(groups), GFP_ATOMIC); | |
1528 | if (!listeners) { | |
1529 | err = -ENOMEM; | |
1530 | goto out_ungrab; | |
1531 | } | |
1532 | old = tbl->listeners; | |
1533 | memcpy(listeners, old, NLGRPSZ(tbl->groups)); | |
1534 | rcu_assign_pointer(tbl->listeners, listeners); | |
1535 | } | |
1536 | tbl->groups = groups; | |
1537 | ||
1538 | out_ungrab: | |
1539 | netlink_table_ungrab(); | |
1540 | synchronize_rcu(); | |
1541 | kfree(old); | |
1542 | return err; | |
1543 | } | |
1544 | EXPORT_SYMBOL(netlink_change_ngroups); | |
1545 | ||
84659eb5 JB |
1546 | /** |
1547 | * netlink_clear_multicast_users - kick off multicast listeners | |
1548 | * | |
1549 | * This function removes all listeners from the given group. | |
1550 | * @ksk: The kernel netlink socket, as returned by | |
1551 | * netlink_kernel_create(). | |
1552 | * @group: The multicast group to clear. | |
1553 | */ | |
1554 | void netlink_clear_multicast_users(struct sock *ksk, unsigned int group) | |
1555 | { | |
1556 | struct sock *sk; | |
1557 | struct hlist_node *node; | |
1558 | struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; | |
1559 | ||
1560 | netlink_table_grab(); | |
1561 | ||
1562 | sk_for_each_bound(sk, node, &tbl->mc_list) | |
1563 | netlink_update_socket_mc(nlk_sk(sk), group, 0); | |
1564 | ||
1565 | netlink_table_ungrab(); | |
1566 | } | |
1567 | EXPORT_SYMBOL(netlink_clear_multicast_users); | |
1568 | ||
1da177e4 | 1569 | void netlink_set_nonroot(int protocol, unsigned int flags) |
746fac4d YH |
1570 | { |
1571 | if ((unsigned int)protocol < MAX_LINKS) | |
1da177e4 | 1572 | nl_table[protocol].nl_nonroot = flags; |
746fac4d | 1573 | } |
6ac552fd | 1574 | EXPORT_SYMBOL(netlink_set_nonroot); |
1da177e4 LT |
1575 | |
1576 | static void netlink_destroy_callback(struct netlink_callback *cb) | |
1577 | { | |
91744f65 | 1578 | kfree_skb(cb->skb); |
1da177e4 LT |
1579 | kfree(cb); |
1580 | } | |
1581 | ||
1582 | /* | |
1583 | * It looks a bit ugly. | |
1584 | * It would be better to create kernel thread. | |
1585 | */ | |
1586 | ||
1587 | static int netlink_dump(struct sock *sk) | |
1588 | { | |
1589 | struct netlink_sock *nlk = nlk_sk(sk); | |
1590 | struct netlink_callback *cb; | |
1591 | struct sk_buff *skb; | |
1592 | struct nlmsghdr *nlh; | |
bf8b79e4 | 1593 | int len, err = -ENOBUFS; |
746fac4d | 1594 | |
1da177e4 LT |
1595 | skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL); |
1596 | if (!skb) | |
bf8b79e4 | 1597 | goto errout; |
1da177e4 | 1598 | |
af65bdfc | 1599 | mutex_lock(nlk->cb_mutex); |
1da177e4 LT |
1600 | |
1601 | cb = nlk->cb; | |
1602 | if (cb == NULL) { | |
bf8b79e4 TG |
1603 | err = -EINVAL; |
1604 | goto errout_skb; | |
1da177e4 LT |
1605 | } |
1606 | ||
1607 | len = cb->dump(skb, cb); | |
1608 | ||
1609 | if (len > 0) { | |
af65bdfc | 1610 | mutex_unlock(nlk->cb_mutex); |
b1153f29 SH |
1611 | |
1612 | if (sk_filter(sk, skb)) | |
1613 | kfree_skb(skb); | |
1614 | else { | |
1615 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
1616 | sk->sk_data_ready(sk, skb->len); | |
1617 | } | |
1da177e4 LT |
1618 | return 0; |
1619 | } | |
1620 | ||
bf8b79e4 TG |
1621 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); |
1622 | if (!nlh) | |
1623 | goto errout_skb; | |
1624 | ||
1625 | memcpy(nlmsg_data(nlh), &len, sizeof(len)); | |
1626 | ||
b1153f29 SH |
1627 | if (sk_filter(sk, skb)) |
1628 | kfree_skb(skb); | |
1629 | else { | |
1630 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
1631 | sk->sk_data_ready(sk, skb->len); | |
1632 | } | |
1da177e4 | 1633 | |
a8f74b22 TG |
1634 | if (cb->done) |
1635 | cb->done(cb); | |
1da177e4 | 1636 | nlk->cb = NULL; |
af65bdfc | 1637 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1638 | |
1639 | netlink_destroy_callback(cb); | |
1da177e4 | 1640 | return 0; |
1797754e | 1641 | |
bf8b79e4 | 1642 | errout_skb: |
af65bdfc | 1643 | mutex_unlock(nlk->cb_mutex); |
bf8b79e4 TG |
1644 | kfree_skb(skb); |
1645 | errout: | |
1646 | return err; | |
1da177e4 LT |
1647 | } |
1648 | ||
1649 | int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, | |
1650 | struct nlmsghdr *nlh, | |
6ac552fd PM |
1651 | int (*dump)(struct sk_buff *skb, |
1652 | struct netlink_callback *), | |
1653 | int (*done)(struct netlink_callback *)) | |
1da177e4 LT |
1654 | { |
1655 | struct netlink_callback *cb; | |
1656 | struct sock *sk; | |
1657 | struct netlink_sock *nlk; | |
1658 | ||
0da974f4 | 1659 | cb = kzalloc(sizeof(*cb), GFP_KERNEL); |
1da177e4 LT |
1660 | if (cb == NULL) |
1661 | return -ENOBUFS; | |
1662 | ||
1da177e4 LT |
1663 | cb->dump = dump; |
1664 | cb->done = done; | |
1665 | cb->nlh = nlh; | |
1666 | atomic_inc(&skb->users); | |
1667 | cb->skb = skb; | |
1668 | ||
3b1e0a65 | 1669 | sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).pid); |
1da177e4 LT |
1670 | if (sk == NULL) { |
1671 | netlink_destroy_callback(cb); | |
1672 | return -ECONNREFUSED; | |
1673 | } | |
1674 | nlk = nlk_sk(sk); | |
3f660d66 | 1675 | /* A dump is in progress... */ |
af65bdfc | 1676 | mutex_lock(nlk->cb_mutex); |
3f660d66 | 1677 | if (nlk->cb) { |
af65bdfc | 1678 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1679 | netlink_destroy_callback(cb); |
1680 | sock_put(sk); | |
1681 | return -EBUSY; | |
1682 | } | |
1683 | nlk->cb = cb; | |
af65bdfc | 1684 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1685 | |
1686 | netlink_dump(sk); | |
1687 | sock_put(sk); | |
5c58298c DL |
1688 | |
1689 | /* We successfully started a dump, by returning -EINTR we | |
1690 | * signal not to send ACK even if it was requested. | |
1691 | */ | |
1692 | return -EINTR; | |
1da177e4 | 1693 | } |
6ac552fd | 1694 | EXPORT_SYMBOL(netlink_dump_start); |
1da177e4 LT |
1695 | |
1696 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) | |
1697 | { | |
1698 | struct sk_buff *skb; | |
1699 | struct nlmsghdr *rep; | |
1700 | struct nlmsgerr *errmsg; | |
339bf98f | 1701 | size_t payload = sizeof(*errmsg); |
1da177e4 | 1702 | |
339bf98f TG |
1703 | /* error messages get the original request appened */ |
1704 | if (err) | |
1705 | payload += nlmsg_len(nlh); | |
1da177e4 | 1706 | |
339bf98f | 1707 | skb = nlmsg_new(payload, GFP_KERNEL); |
1da177e4 LT |
1708 | if (!skb) { |
1709 | struct sock *sk; | |
1710 | ||
3b1e0a65 | 1711 | sk = netlink_lookup(sock_net(in_skb->sk), |
b4b51029 | 1712 | in_skb->sk->sk_protocol, |
1da177e4 LT |
1713 | NETLINK_CB(in_skb).pid); |
1714 | if (sk) { | |
1715 | sk->sk_err = ENOBUFS; | |
1716 | sk->sk_error_report(sk); | |
1717 | sock_put(sk); | |
1718 | } | |
1719 | return; | |
1720 | } | |
1721 | ||
1722 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, | |
1797754e | 1723 | NLMSG_ERROR, sizeof(struct nlmsgerr), 0); |
bf8b79e4 | 1724 | errmsg = nlmsg_data(rep); |
1da177e4 | 1725 | errmsg->error = err; |
bf8b79e4 | 1726 | memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh)); |
1da177e4 LT |
1727 | netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT); |
1728 | } | |
6ac552fd | 1729 | EXPORT_SYMBOL(netlink_ack); |
1da177e4 | 1730 | |
cd40b7d3 | 1731 | int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
1d00a4eb | 1732 | struct nlmsghdr *)) |
82ace47a | 1733 | { |
82ace47a TG |
1734 | struct nlmsghdr *nlh; |
1735 | int err; | |
1736 | ||
1737 | while (skb->len >= nlmsg_total_size(0)) { | |
cd40b7d3 DL |
1738 | int msglen; |
1739 | ||
b529ccf2 | 1740 | nlh = nlmsg_hdr(skb); |
d35b6856 | 1741 | err = 0; |
82ace47a | 1742 | |
ad8e4b75 | 1743 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
1744 | return 0; |
1745 | ||
d35b6856 TG |
1746 | /* Only requests are handled by the kernel */ |
1747 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | |
5c58298c | 1748 | goto ack; |
45e7ae7f TG |
1749 | |
1750 | /* Skip control messages */ | |
1751 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | |
5c58298c | 1752 | goto ack; |
d35b6856 | 1753 | |
1d00a4eb | 1754 | err = cb(skb, nlh); |
5c58298c DL |
1755 | if (err == -EINTR) |
1756 | goto skip; | |
1757 | ||
1758 | ack: | |
d35b6856 | 1759 | if (nlh->nlmsg_flags & NLM_F_ACK || err) |
82ace47a | 1760 | netlink_ack(skb, nlh, err); |
82ace47a | 1761 | |
5c58298c | 1762 | skip: |
6ac552fd | 1763 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
cd40b7d3 DL |
1764 | if (msglen > skb->len) |
1765 | msglen = skb->len; | |
1766 | skb_pull(skb, msglen); | |
82ace47a TG |
1767 | } |
1768 | ||
1769 | return 0; | |
1770 | } | |
6ac552fd | 1771 | EXPORT_SYMBOL(netlink_rcv_skb); |
82ace47a | 1772 | |
d387f6ad TG |
1773 | /** |
1774 | * nlmsg_notify - send a notification netlink message | |
1775 | * @sk: netlink socket to use | |
1776 | * @skb: notification message | |
1777 | * @pid: destination netlink pid for reports or 0 | |
1778 | * @group: destination multicast group or 0 | |
1779 | * @report: 1 to report back, 0 to disable | |
1780 | * @flags: allocation flags | |
1781 | */ | |
1782 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid, | |
1783 | unsigned int group, int report, gfp_t flags) | |
1784 | { | |
1785 | int err = 0; | |
1786 | ||
1787 | if (group) { | |
1788 | int exclude_pid = 0; | |
1789 | ||
1790 | if (report) { | |
1791 | atomic_inc(&skb->users); | |
1792 | exclude_pid = pid; | |
1793 | } | |
1794 | ||
1ce85fe4 PNA |
1795 | /* errors reported via destination sk->sk_err, but propagate |
1796 | * delivery errors if NETLINK_BROADCAST_ERROR flag is set */ | |
1797 | err = nlmsg_multicast(sk, skb, exclude_pid, group, flags); | |
d387f6ad TG |
1798 | } |
1799 | ||
1ce85fe4 PNA |
1800 | if (report) { |
1801 | int err2; | |
1802 | ||
1803 | err2 = nlmsg_unicast(sk, skb, pid); | |
1804 | if (!err || err == -ESRCH) | |
1805 | err = err2; | |
1806 | } | |
d387f6ad TG |
1807 | |
1808 | return err; | |
1809 | } | |
6ac552fd | 1810 | EXPORT_SYMBOL(nlmsg_notify); |
d387f6ad | 1811 | |
1da177e4 LT |
1812 | #ifdef CONFIG_PROC_FS |
1813 | struct nl_seq_iter { | |
e372c414 | 1814 | struct seq_net_private p; |
1da177e4 LT |
1815 | int link; |
1816 | int hash_idx; | |
1817 | }; | |
1818 | ||
1819 | static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) | |
1820 | { | |
1821 | struct nl_seq_iter *iter = seq->private; | |
1822 | int i, j; | |
1823 | struct sock *s; | |
1824 | struct hlist_node *node; | |
1825 | loff_t off = 0; | |
1826 | ||
6ac552fd | 1827 | for (i = 0; i < MAX_LINKS; i++) { |
1da177e4 LT |
1828 | struct nl_pid_hash *hash = &nl_table[i].hash; |
1829 | ||
1830 | for (j = 0; j <= hash->mask; j++) { | |
1831 | sk_for_each(s, node, &hash->table[j]) { | |
1218854a | 1832 | if (sock_net(s) != seq_file_net(seq)) |
b4b51029 | 1833 | continue; |
1da177e4 LT |
1834 | if (off == pos) { |
1835 | iter->link = i; | |
1836 | iter->hash_idx = j; | |
1837 | return s; | |
1838 | } | |
1839 | ++off; | |
1840 | } | |
1841 | } | |
1842 | } | |
1843 | return NULL; | |
1844 | } | |
1845 | ||
1846 | static void *netlink_seq_start(struct seq_file *seq, loff_t *pos) | |
9a429c49 | 1847 | __acquires(nl_table_lock) |
1da177e4 LT |
1848 | { |
1849 | read_lock(&nl_table_lock); | |
1850 | return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
1851 | } | |
1852 | ||
1853 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
1854 | { | |
1855 | struct sock *s; | |
1856 | struct nl_seq_iter *iter; | |
1857 | int i, j; | |
1858 | ||
1859 | ++*pos; | |
1860 | ||
1861 | if (v == SEQ_START_TOKEN) | |
1862 | return netlink_seq_socket_idx(seq, 0); | |
746fac4d | 1863 | |
b4b51029 EB |
1864 | iter = seq->private; |
1865 | s = v; | |
1866 | do { | |
1867 | s = sk_next(s); | |
1218854a | 1868 | } while (s && sock_net(s) != seq_file_net(seq)); |
1da177e4 LT |
1869 | if (s) |
1870 | return s; | |
1871 | ||
1da177e4 LT |
1872 | i = iter->link; |
1873 | j = iter->hash_idx + 1; | |
1874 | ||
1875 | do { | |
1876 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1877 | ||
1878 | for (; j <= hash->mask; j++) { | |
1879 | s = sk_head(&hash->table[j]); | |
1218854a | 1880 | while (s && sock_net(s) != seq_file_net(seq)) |
b4b51029 | 1881 | s = sk_next(s); |
1da177e4 LT |
1882 | if (s) { |
1883 | iter->link = i; | |
1884 | iter->hash_idx = j; | |
1885 | return s; | |
1886 | } | |
1887 | } | |
1888 | ||
1889 | j = 0; | |
1890 | } while (++i < MAX_LINKS); | |
1891 | ||
1892 | return NULL; | |
1893 | } | |
1894 | ||
1895 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
9a429c49 | 1896 | __releases(nl_table_lock) |
1da177e4 LT |
1897 | { |
1898 | read_unlock(&nl_table_lock); | |
1899 | } | |
1900 | ||
1901 | ||
1902 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
1903 | { | |
1904 | if (v == SEQ_START_TOKEN) | |
1905 | seq_puts(seq, | |
1906 | "sk Eth Pid Groups " | |
38938bfe | 1907 | "Rmem Wmem Dump Locks Drops\n"); |
1da177e4 LT |
1908 | else { |
1909 | struct sock *s = v; | |
1910 | struct netlink_sock *nlk = nlk_sk(s); | |
1911 | ||
38938bfe | 1912 | seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %-8d %-8d\n", |
1da177e4 LT |
1913 | s, |
1914 | s->sk_protocol, | |
1915 | nlk->pid, | |
513c2500 | 1916 | nlk->groups ? (u32)nlk->groups[0] : 0, |
31e6d363 ED |
1917 | sk_rmem_alloc_get(s), |
1918 | sk_wmem_alloc_get(s), | |
1da177e4 | 1919 | nlk->cb, |
38938bfe PNA |
1920 | atomic_read(&s->sk_refcnt), |
1921 | atomic_read(&s->sk_drops) | |
1da177e4 LT |
1922 | ); |
1923 | ||
1924 | } | |
1925 | return 0; | |
1926 | } | |
1927 | ||
56b3d975 | 1928 | static const struct seq_operations netlink_seq_ops = { |
1da177e4 LT |
1929 | .start = netlink_seq_start, |
1930 | .next = netlink_seq_next, | |
1931 | .stop = netlink_seq_stop, | |
1932 | .show = netlink_seq_show, | |
1933 | }; | |
1934 | ||
1935 | ||
1936 | static int netlink_seq_open(struct inode *inode, struct file *file) | |
1937 | { | |
e372c414 DL |
1938 | return seq_open_net(inode, file, &netlink_seq_ops, |
1939 | sizeof(struct nl_seq_iter)); | |
b4b51029 EB |
1940 | } |
1941 | ||
da7071d7 | 1942 | static const struct file_operations netlink_seq_fops = { |
1da177e4 LT |
1943 | .owner = THIS_MODULE, |
1944 | .open = netlink_seq_open, | |
1945 | .read = seq_read, | |
1946 | .llseek = seq_lseek, | |
e372c414 | 1947 | .release = seq_release_net, |
1da177e4 LT |
1948 | }; |
1949 | ||
1950 | #endif | |
1951 | ||
1952 | int netlink_register_notifier(struct notifier_block *nb) | |
1953 | { | |
e041c683 | 1954 | return atomic_notifier_chain_register(&netlink_chain, nb); |
1da177e4 | 1955 | } |
6ac552fd | 1956 | EXPORT_SYMBOL(netlink_register_notifier); |
1da177e4 LT |
1957 | |
1958 | int netlink_unregister_notifier(struct notifier_block *nb) | |
1959 | { | |
e041c683 | 1960 | return atomic_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 | 1961 | } |
6ac552fd | 1962 | EXPORT_SYMBOL(netlink_unregister_notifier); |
746fac4d | 1963 | |
90ddc4f0 | 1964 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
1965 | .family = PF_NETLINK, |
1966 | .owner = THIS_MODULE, | |
1967 | .release = netlink_release, | |
1968 | .bind = netlink_bind, | |
1969 | .connect = netlink_connect, | |
1970 | .socketpair = sock_no_socketpair, | |
1971 | .accept = sock_no_accept, | |
1972 | .getname = netlink_getname, | |
1973 | .poll = datagram_poll, | |
1974 | .ioctl = sock_no_ioctl, | |
1975 | .listen = sock_no_listen, | |
1976 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
1977 | .setsockopt = netlink_setsockopt, |
1978 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
1979 | .sendmsg = netlink_sendmsg, |
1980 | .recvmsg = netlink_recvmsg, | |
1981 | .mmap = sock_no_mmap, | |
1982 | .sendpage = sock_no_sendpage, | |
1983 | }; | |
1984 | ||
1985 | static struct net_proto_family netlink_family_ops = { | |
1986 | .family = PF_NETLINK, | |
1987 | .create = netlink_create, | |
1988 | .owner = THIS_MODULE, /* for consistency 8) */ | |
1989 | }; | |
1990 | ||
4665079c | 1991 | static int __net_init netlink_net_init(struct net *net) |
b4b51029 EB |
1992 | { |
1993 | #ifdef CONFIG_PROC_FS | |
1994 | if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops)) | |
1995 | return -ENOMEM; | |
1996 | #endif | |
1997 | return 0; | |
1998 | } | |
1999 | ||
4665079c | 2000 | static void __net_exit netlink_net_exit(struct net *net) |
b4b51029 EB |
2001 | { |
2002 | #ifdef CONFIG_PROC_FS | |
2003 | proc_net_remove(net, "netlink"); | |
2004 | #endif | |
2005 | } | |
2006 | ||
022cbae6 | 2007 | static struct pernet_operations __net_initdata netlink_net_ops = { |
b4b51029 EB |
2008 | .init = netlink_net_init, |
2009 | .exit = netlink_net_exit, | |
2010 | }; | |
2011 | ||
1da177e4 LT |
2012 | static int __init netlink_proto_init(void) |
2013 | { | |
2014 | struct sk_buff *dummy_skb; | |
2015 | int i; | |
26ff5ddc | 2016 | unsigned long limit; |
1da177e4 LT |
2017 | unsigned int order; |
2018 | int err = proto_register(&netlink_proto, 0); | |
2019 | ||
2020 | if (err != 0) | |
2021 | goto out; | |
2022 | ||
ef047f5e | 2023 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb)); |
1da177e4 | 2024 | |
0da974f4 | 2025 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
2026 | if (!nl_table) |
2027 | goto panic; | |
1da177e4 | 2028 | |
1da177e4 | 2029 | if (num_physpages >= (128 * 1024)) |
26ff5ddc | 2030 | limit = num_physpages >> (21 - PAGE_SHIFT); |
1da177e4 | 2031 | else |
26ff5ddc | 2032 | limit = num_physpages >> (23 - PAGE_SHIFT); |
1da177e4 | 2033 | |
26ff5ddc DC |
2034 | order = get_bitmask_order(limit) - 1 + PAGE_SHIFT; |
2035 | limit = (1UL << order) / sizeof(struct hlist_head); | |
2036 | order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1; | |
1da177e4 LT |
2037 | |
2038 | for (i = 0; i < MAX_LINKS; i++) { | |
2039 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
2040 | ||
ea72912c | 2041 | hash->table = nl_pid_hash_zalloc(1 * sizeof(*hash->table)); |
1da177e4 LT |
2042 | if (!hash->table) { |
2043 | while (i-- > 0) | |
2044 | nl_pid_hash_free(nl_table[i].hash.table, | |
2045 | 1 * sizeof(*hash->table)); | |
2046 | kfree(nl_table); | |
fab2caf6 | 2047 | goto panic; |
1da177e4 | 2048 | } |
1da177e4 LT |
2049 | hash->max_shift = order; |
2050 | hash->shift = 0; | |
2051 | hash->mask = 0; | |
2052 | hash->rehash_time = jiffies; | |
2053 | } | |
2054 | ||
2055 | sock_register(&netlink_family_ops); | |
b4b51029 | 2056 | register_pernet_subsys(&netlink_net_ops); |
746fac4d | 2057 | /* The netlink device handler may be needed early. */ |
1da177e4 LT |
2058 | rtnetlink_init(); |
2059 | out: | |
2060 | return err; | |
fab2caf6 AM |
2061 | panic: |
2062 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
2063 | } |
2064 | ||
1da177e4 | 2065 | core_initcall(netlink_proto_init); |