Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * NETLINK Kernel-user communication protocol. | |
3 | * | |
4 | * Authors: Alan Cox <alan@redhat.com> | |
5 | * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
746fac4d | 11 | * |
1da177e4 LT |
12 | * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith |
13 | * added netlink_proto_exit | |
14 | * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br> | |
15 | * use nlk_sk, as sk->protinfo is on a diet 8) | |
4fdb3bb7 HW |
16 | * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org> |
17 | * - inc module use count of module that owns | |
18 | * the kernel socket in case userspace opens | |
19 | * socket of same protocol | |
20 | * - remove all module support, since netlink is | |
21 | * mandatory if CONFIG_NET=y these days | |
1da177e4 LT |
22 | */ |
23 | ||
1da177e4 LT |
24 | #include <linux/module.h> |
25 | ||
4fc268d2 | 26 | #include <linux/capability.h> |
1da177e4 LT |
27 | #include <linux/kernel.h> |
28 | #include <linux/init.h> | |
1da177e4 LT |
29 | #include <linux/signal.h> |
30 | #include <linux/sched.h> | |
31 | #include <linux/errno.h> | |
32 | #include <linux/string.h> | |
33 | #include <linux/stat.h> | |
34 | #include <linux/socket.h> | |
35 | #include <linux/un.h> | |
36 | #include <linux/fcntl.h> | |
37 | #include <linux/termios.h> | |
38 | #include <linux/sockios.h> | |
39 | #include <linux/net.h> | |
40 | #include <linux/fs.h> | |
41 | #include <linux/slab.h> | |
42 | #include <asm/uaccess.h> | |
43 | #include <linux/skbuff.h> | |
44 | #include <linux/netdevice.h> | |
45 | #include <linux/rtnetlink.h> | |
46 | #include <linux/proc_fs.h> | |
47 | #include <linux/seq_file.h> | |
48 | #include <linux/smp_lock.h> | |
49 | #include <linux/notifier.h> | |
50 | #include <linux/security.h> | |
51 | #include <linux/jhash.h> | |
52 | #include <linux/jiffies.h> | |
53 | #include <linux/random.h> | |
54 | #include <linux/bitops.h> | |
55 | #include <linux/mm.h> | |
56 | #include <linux/types.h> | |
54e0f520 | 57 | #include <linux/audit.h> |
e7c34970 | 58 | #include <linux/selinux.h> |
af65bdfc | 59 | #include <linux/mutex.h> |
54e0f520 | 60 | |
1da177e4 LT |
61 | #include <net/sock.h> |
62 | #include <net/scm.h> | |
82ace47a | 63 | #include <net/netlink.h> |
1da177e4 | 64 | |
f7fa9b10 | 65 | #define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8) |
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; | |
1da177e4 | 82 | void (*data_ready)(struct sock *sk, int bytes); |
77247bbb | 83 | struct module *module; |
1da177e4 LT |
84 | }; |
85 | ||
77247bbb | 86 | #define NETLINK_KERNEL_SOCKET 0x1 |
9a4595bc | 87 | #define NETLINK_RECV_PKTINFO 0x2 |
77247bbb | 88 | |
1da177e4 LT |
89 | static inline struct netlink_sock *nlk_sk(struct sock *sk) |
90 | { | |
91 | return (struct netlink_sock *)sk; | |
92 | } | |
93 | ||
94 | struct nl_pid_hash { | |
95 | struct hlist_head *table; | |
96 | unsigned long rehash_time; | |
97 | ||
98 | unsigned int mask; | |
99 | unsigned int shift; | |
100 | ||
101 | unsigned int entries; | |
102 | unsigned int max_shift; | |
103 | ||
104 | u32 rnd; | |
105 | }; | |
106 | ||
107 | struct netlink_table { | |
108 | struct nl_pid_hash hash; | |
109 | struct hlist_head mc_list; | |
4277a083 | 110 | unsigned long *listeners; |
1da177e4 | 111 | unsigned int nl_nonroot; |
f7fa9b10 | 112 | unsigned int groups; |
af65bdfc | 113 | struct mutex *cb_mutex; |
77247bbb | 114 | struct module *module; |
ab33a171 | 115 | int registered; |
1da177e4 LT |
116 | }; |
117 | ||
118 | static struct netlink_table *nl_table; | |
119 | ||
120 | static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); | |
121 | ||
122 | static int netlink_dump(struct sock *sk); | |
123 | static void netlink_destroy_callback(struct netlink_callback *cb); | |
42bad1da | 124 | static void netlink_queue_skip(struct nlmsghdr *nlh, struct sk_buff *skb); |
1da177e4 LT |
125 | |
126 | static DEFINE_RWLOCK(nl_table_lock); | |
127 | static atomic_t nl_table_users = ATOMIC_INIT(0); | |
128 | ||
e041c683 | 129 | static ATOMIC_NOTIFIER_HEAD(netlink_chain); |
1da177e4 | 130 | |
d629b836 PM |
131 | static u32 netlink_group_mask(u32 group) |
132 | { | |
133 | return group ? 1 << (group - 1) : 0; | |
134 | } | |
135 | ||
1da177e4 LT |
136 | static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid) |
137 | { | |
138 | return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask]; | |
139 | } | |
140 | ||
141 | static void netlink_sock_destruct(struct sock *sk) | |
142 | { | |
143 | skb_queue_purge(&sk->sk_receive_queue); | |
144 | ||
145 | if (!sock_flag(sk, SOCK_DEAD)) { | |
146 | printk("Freeing alive netlink socket %p\n", sk); | |
147 | return; | |
148 | } | |
149 | BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc)); | |
150 | BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc)); | |
151 | BUG_TRAP(!nlk_sk(sk)->cb); | |
f7fa9b10 | 152 | BUG_TRAP(!nlk_sk(sk)->groups); |
1da177e4 LT |
153 | } |
154 | ||
155 | /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on SMP. | |
156 | * Look, when several writers sleep and reader wakes them up, all but one | |
157 | * immediately hit write lock and grab all the cpus. Exclusive sleep solves | |
158 | * this, _but_ remember, it adds useless work on UP machines. | |
159 | */ | |
160 | ||
161 | static void netlink_table_grab(void) | |
162 | { | |
6abd219c | 163 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
164 | |
165 | if (atomic_read(&nl_table_users)) { | |
166 | DECLARE_WAITQUEUE(wait, current); | |
167 | ||
168 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
169 | for(;;) { | |
170 | set_current_state(TASK_UNINTERRUPTIBLE); | |
171 | if (atomic_read(&nl_table_users) == 0) | |
172 | break; | |
6abd219c | 173 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 174 | schedule(); |
6abd219c | 175 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
176 | } |
177 | ||
178 | __set_current_state(TASK_RUNNING); | |
179 | remove_wait_queue(&nl_table_wait, &wait); | |
180 | } | |
181 | } | |
182 | ||
183 | static __inline__ void netlink_table_ungrab(void) | |
184 | { | |
6abd219c | 185 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
186 | wake_up(&nl_table_wait); |
187 | } | |
188 | ||
189 | static __inline__ void | |
190 | netlink_lock_table(void) | |
191 | { | |
192 | /* read_lock() synchronizes us to netlink_table_grab */ | |
193 | ||
194 | read_lock(&nl_table_lock); | |
195 | atomic_inc(&nl_table_users); | |
196 | read_unlock(&nl_table_lock); | |
197 | } | |
198 | ||
199 | static __inline__ void | |
200 | netlink_unlock_table(void) | |
201 | { | |
202 | if (atomic_dec_and_test(&nl_table_users)) | |
203 | wake_up(&nl_table_wait); | |
204 | } | |
205 | ||
206 | static __inline__ struct sock *netlink_lookup(int protocol, u32 pid) | |
207 | { | |
208 | struct nl_pid_hash *hash = &nl_table[protocol].hash; | |
209 | struct hlist_head *head; | |
210 | struct sock *sk; | |
211 | struct hlist_node *node; | |
212 | ||
213 | read_lock(&nl_table_lock); | |
214 | head = nl_pid_hashfn(hash, pid); | |
215 | sk_for_each(sk, node, head) { | |
216 | if (nlk_sk(sk)->pid == pid) { | |
217 | sock_hold(sk); | |
218 | goto found; | |
219 | } | |
220 | } | |
221 | sk = NULL; | |
222 | found: | |
223 | read_unlock(&nl_table_lock); | |
224 | return sk; | |
225 | } | |
226 | ||
227 | static inline struct hlist_head *nl_pid_hash_alloc(size_t size) | |
228 | { | |
229 | if (size <= PAGE_SIZE) | |
230 | return kmalloc(size, GFP_ATOMIC); | |
231 | else | |
232 | return (struct hlist_head *) | |
233 | __get_free_pages(GFP_ATOMIC, get_order(size)); | |
234 | } | |
235 | ||
236 | static inline void nl_pid_hash_free(struct hlist_head *table, size_t size) | |
237 | { | |
238 | if (size <= PAGE_SIZE) | |
239 | kfree(table); | |
240 | else | |
241 | free_pages((unsigned long)table, get_order(size)); | |
242 | } | |
243 | ||
244 | static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow) | |
245 | { | |
246 | unsigned int omask, mask, shift; | |
247 | size_t osize, size; | |
248 | struct hlist_head *otable, *table; | |
249 | int i; | |
250 | ||
251 | omask = mask = hash->mask; | |
252 | osize = size = (mask + 1) * sizeof(*table); | |
253 | shift = hash->shift; | |
254 | ||
255 | if (grow) { | |
256 | if (++shift > hash->max_shift) | |
257 | return 0; | |
258 | mask = mask * 2 + 1; | |
259 | size *= 2; | |
260 | } | |
261 | ||
262 | table = nl_pid_hash_alloc(size); | |
263 | if (!table) | |
264 | return 0; | |
265 | ||
266 | memset(table, 0, size); | |
267 | otable = hash->table; | |
268 | hash->table = table; | |
269 | hash->mask = mask; | |
270 | hash->shift = shift; | |
271 | get_random_bytes(&hash->rnd, sizeof(hash->rnd)); | |
272 | ||
273 | for (i = 0; i <= omask; i++) { | |
274 | struct sock *sk; | |
275 | struct hlist_node *node, *tmp; | |
276 | ||
277 | sk_for_each_safe(sk, node, tmp, &otable[i]) | |
278 | __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid)); | |
279 | } | |
280 | ||
281 | nl_pid_hash_free(otable, osize); | |
282 | hash->rehash_time = jiffies + 10 * 60 * HZ; | |
283 | return 1; | |
284 | } | |
285 | ||
286 | static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len) | |
287 | { | |
288 | int avg = hash->entries >> hash->shift; | |
289 | ||
290 | if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1)) | |
291 | return 1; | |
292 | ||
293 | if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) { | |
294 | nl_pid_hash_rehash(hash, 0); | |
295 | return 1; | |
296 | } | |
297 | ||
298 | return 0; | |
299 | } | |
300 | ||
90ddc4f0 | 301 | static const struct proto_ops netlink_ops; |
1da177e4 | 302 | |
4277a083 PM |
303 | static void |
304 | netlink_update_listeners(struct sock *sk) | |
305 | { | |
306 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
307 | struct hlist_node *node; | |
308 | unsigned long mask; | |
309 | unsigned int i; | |
310 | ||
311 | for (i = 0; i < NLGRPSZ(tbl->groups)/sizeof(unsigned long); i++) { | |
312 | mask = 0; | |
313 | sk_for_each_bound(sk, node, &tbl->mc_list) | |
314 | mask |= nlk_sk(sk)->groups[i]; | |
315 | tbl->listeners[i] = mask; | |
316 | } | |
317 | /* this function is only called with the netlink table "grabbed", which | |
318 | * makes sure updates are visible before bind or setsockopt return. */ | |
319 | } | |
320 | ||
1da177e4 LT |
321 | static int netlink_insert(struct sock *sk, u32 pid) |
322 | { | |
323 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; | |
324 | struct hlist_head *head; | |
325 | int err = -EADDRINUSE; | |
326 | struct sock *osk; | |
327 | struct hlist_node *node; | |
328 | int len; | |
329 | ||
330 | netlink_table_grab(); | |
331 | head = nl_pid_hashfn(hash, pid); | |
332 | len = 0; | |
333 | sk_for_each(osk, node, head) { | |
334 | if (nlk_sk(osk)->pid == pid) | |
335 | break; | |
336 | len++; | |
337 | } | |
338 | if (node) | |
339 | goto err; | |
340 | ||
341 | err = -EBUSY; | |
342 | if (nlk_sk(sk)->pid) | |
343 | goto err; | |
344 | ||
345 | err = -ENOMEM; | |
346 | if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX)) | |
347 | goto err; | |
348 | ||
349 | if (len && nl_pid_hash_dilute(hash, len)) | |
350 | head = nl_pid_hashfn(hash, pid); | |
351 | hash->entries++; | |
352 | nlk_sk(sk)->pid = pid; | |
353 | sk_add_node(sk, head); | |
354 | err = 0; | |
355 | ||
356 | err: | |
357 | netlink_table_ungrab(); | |
358 | return err; | |
359 | } | |
360 | ||
361 | static void netlink_remove(struct sock *sk) | |
362 | { | |
363 | netlink_table_grab(); | |
d470e3b4 DM |
364 | if (sk_del_node_init(sk)) |
365 | nl_table[sk->sk_protocol].hash.entries--; | |
f7fa9b10 | 366 | if (nlk_sk(sk)->subscriptions) |
1da177e4 LT |
367 | __sk_del_bind_node(sk); |
368 | netlink_table_ungrab(); | |
369 | } | |
370 | ||
371 | static struct proto netlink_proto = { | |
372 | .name = "NETLINK", | |
373 | .owner = THIS_MODULE, | |
374 | .obj_size = sizeof(struct netlink_sock), | |
375 | }; | |
376 | ||
af65bdfc PM |
377 | static int __netlink_create(struct socket *sock, struct mutex *cb_mutex, |
378 | int protocol) | |
1da177e4 LT |
379 | { |
380 | struct sock *sk; | |
381 | struct netlink_sock *nlk; | |
ab33a171 PM |
382 | |
383 | sock->ops = &netlink_ops; | |
384 | ||
385 | sk = sk_alloc(PF_NETLINK, GFP_KERNEL, &netlink_proto, 1); | |
386 | if (!sk) | |
387 | return -ENOMEM; | |
388 | ||
389 | sock_init_data(sock, sk); | |
390 | ||
391 | nlk = nlk_sk(sk); | |
ffa4d721 PM |
392 | if (cb_mutex) |
393 | nlk->cb_mutex = cb_mutex; | |
394 | else { | |
395 | nlk->cb_mutex = &nlk->cb_def_mutex; | |
396 | mutex_init(nlk->cb_mutex); | |
397 | } | |
ab33a171 PM |
398 | init_waitqueue_head(&nlk->wait); |
399 | ||
400 | sk->sk_destruct = netlink_sock_destruct; | |
401 | sk->sk_protocol = protocol; | |
402 | return 0; | |
403 | } | |
404 | ||
405 | static int netlink_create(struct socket *sock, int protocol) | |
406 | { | |
407 | struct module *module = NULL; | |
af65bdfc | 408 | struct mutex *cb_mutex; |
f7fa9b10 | 409 | struct netlink_sock *nlk; |
ab33a171 | 410 | int err = 0; |
1da177e4 LT |
411 | |
412 | sock->state = SS_UNCONNECTED; | |
413 | ||
414 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
415 | return -ESOCKTNOSUPPORT; | |
416 | ||
417 | if (protocol<0 || protocol >= MAX_LINKS) | |
418 | return -EPROTONOSUPPORT; | |
419 | ||
77247bbb | 420 | netlink_lock_table(); |
4fdb3bb7 | 421 | #ifdef CONFIG_KMOD |
ab33a171 | 422 | if (!nl_table[protocol].registered) { |
77247bbb | 423 | netlink_unlock_table(); |
4fdb3bb7 | 424 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 425 | netlink_lock_table(); |
4fdb3bb7 | 426 | } |
ab33a171 PM |
427 | #endif |
428 | if (nl_table[protocol].registered && | |
429 | try_module_get(nl_table[protocol].module)) | |
430 | module = nl_table[protocol].module; | |
af65bdfc | 431 | cb_mutex = nl_table[protocol].cb_mutex; |
77247bbb | 432 | netlink_unlock_table(); |
4fdb3bb7 | 433 | |
af65bdfc | 434 | if ((err = __netlink_create(sock, cb_mutex, protocol)) < 0) |
f7fa9b10 PM |
435 | goto out_module; |
436 | ||
437 | nlk = nlk_sk(sock->sk); | |
f7fa9b10 | 438 | nlk->module = module; |
ab33a171 PM |
439 | out: |
440 | return err; | |
1da177e4 | 441 | |
ab33a171 PM |
442 | out_module: |
443 | module_put(module); | |
444 | goto out; | |
1da177e4 LT |
445 | } |
446 | ||
447 | static int netlink_release(struct socket *sock) | |
448 | { | |
449 | struct sock *sk = sock->sk; | |
450 | struct netlink_sock *nlk; | |
451 | ||
452 | if (!sk) | |
453 | return 0; | |
454 | ||
455 | netlink_remove(sk); | |
ac57b3a9 | 456 | sock_orphan(sk); |
1da177e4 LT |
457 | nlk = nlk_sk(sk); |
458 | ||
af65bdfc | 459 | mutex_lock(nlk->cb_mutex); |
1da177e4 | 460 | if (nlk->cb) { |
a8f74b22 TG |
461 | if (nlk->cb->done) |
462 | nlk->cb->done(nlk->cb); | |
1da177e4 LT |
463 | netlink_destroy_callback(nlk->cb); |
464 | nlk->cb = NULL; | |
1da177e4 | 465 | } |
af65bdfc | 466 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
467 | |
468 | /* OK. Socket is unlinked, and, therefore, | |
469 | no new packets will arrive */ | |
470 | ||
1da177e4 LT |
471 | sock->sk = NULL; |
472 | wake_up_interruptible_all(&nlk->wait); | |
473 | ||
474 | skb_queue_purge(&sk->sk_write_queue); | |
475 | ||
f7fa9b10 | 476 | if (nlk->pid && !nlk->subscriptions) { |
1da177e4 LT |
477 | struct netlink_notify n = { |
478 | .protocol = sk->sk_protocol, | |
479 | .pid = nlk->pid, | |
480 | }; | |
e041c683 AS |
481 | atomic_notifier_call_chain(&netlink_chain, |
482 | NETLINK_URELEASE, &n); | |
746fac4d | 483 | } |
4fdb3bb7 | 484 | |
5e7c001c | 485 | module_put(nlk->module); |
4fdb3bb7 | 486 | |
4277a083 | 487 | netlink_table_grab(); |
77247bbb | 488 | if (nlk->flags & NETLINK_KERNEL_SOCKET) { |
4277a083 | 489 | kfree(nl_table[sk->sk_protocol].listeners); |
77247bbb | 490 | nl_table[sk->sk_protocol].module = NULL; |
ab33a171 | 491 | nl_table[sk->sk_protocol].registered = 0; |
4277a083 PM |
492 | } else if (nlk->subscriptions) |
493 | netlink_update_listeners(sk); | |
494 | netlink_table_ungrab(); | |
77247bbb | 495 | |
f7fa9b10 PM |
496 | kfree(nlk->groups); |
497 | nlk->groups = NULL; | |
498 | ||
1da177e4 LT |
499 | sock_put(sk); |
500 | return 0; | |
501 | } | |
502 | ||
503 | static int netlink_autobind(struct socket *sock) | |
504 | { | |
505 | struct sock *sk = sock->sk; | |
506 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; | |
507 | struct hlist_head *head; | |
508 | struct sock *osk; | |
509 | struct hlist_node *node; | |
c27bd492 | 510 | s32 pid = current->tgid; |
1da177e4 LT |
511 | int err; |
512 | static s32 rover = -4097; | |
513 | ||
514 | retry: | |
515 | cond_resched(); | |
516 | netlink_table_grab(); | |
517 | head = nl_pid_hashfn(hash, pid); | |
518 | sk_for_each(osk, node, head) { | |
519 | if (nlk_sk(osk)->pid == pid) { | |
520 | /* Bind collision, search negative pid values. */ | |
521 | pid = rover--; | |
522 | if (rover > -4097) | |
523 | rover = -4097; | |
524 | netlink_table_ungrab(); | |
525 | goto retry; | |
526 | } | |
527 | } | |
528 | netlink_table_ungrab(); | |
529 | ||
530 | err = netlink_insert(sk, pid); | |
531 | if (err == -EADDRINUSE) | |
532 | goto retry; | |
d470e3b4 DM |
533 | |
534 | /* If 2 threads race to autobind, that is fine. */ | |
535 | if (err == -EBUSY) | |
536 | err = 0; | |
537 | ||
538 | return err; | |
1da177e4 LT |
539 | } |
540 | ||
746fac4d YH |
541 | static inline int netlink_capable(struct socket *sock, unsigned int flag) |
542 | { | |
1da177e4 LT |
543 | return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) || |
544 | capable(CAP_NET_ADMIN); | |
746fac4d | 545 | } |
1da177e4 | 546 | |
f7fa9b10 PM |
547 | static void |
548 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
549 | { | |
550 | struct netlink_sock *nlk = nlk_sk(sk); | |
551 | ||
552 | if (nlk->subscriptions && !subscriptions) | |
553 | __sk_del_bind_node(sk); | |
554 | else if (!nlk->subscriptions && subscriptions) | |
555 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
556 | nlk->subscriptions = subscriptions; | |
557 | } | |
558 | ||
513c2500 PM |
559 | static int netlink_alloc_groups(struct sock *sk) |
560 | { | |
561 | struct netlink_sock *nlk = nlk_sk(sk); | |
562 | unsigned int groups; | |
563 | int err = 0; | |
564 | ||
565 | netlink_lock_table(); | |
566 | groups = nl_table[sk->sk_protocol].groups; | |
567 | if (!nl_table[sk->sk_protocol].registered) | |
568 | err = -ENOENT; | |
569 | netlink_unlock_table(); | |
570 | ||
571 | if (err) | |
572 | return err; | |
573 | ||
0da974f4 | 574 | nlk->groups = kzalloc(NLGRPSZ(groups), GFP_KERNEL); |
513c2500 PM |
575 | if (nlk->groups == NULL) |
576 | return -ENOMEM; | |
513c2500 PM |
577 | nlk->ngroups = groups; |
578 | return 0; | |
579 | } | |
580 | ||
1da177e4 LT |
581 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len) |
582 | { | |
583 | struct sock *sk = sock->sk; | |
584 | struct netlink_sock *nlk = nlk_sk(sk); | |
585 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
586 | int err; | |
746fac4d | 587 | |
1da177e4 LT |
588 | if (nladdr->nl_family != AF_NETLINK) |
589 | return -EINVAL; | |
590 | ||
591 | /* Only superuser is allowed to listen multicasts */ | |
513c2500 PM |
592 | if (nladdr->nl_groups) { |
593 | if (!netlink_capable(sock, NL_NONROOT_RECV)) | |
594 | return -EPERM; | |
595 | if (nlk->groups == NULL) { | |
596 | err = netlink_alloc_groups(sk); | |
597 | if (err) | |
598 | return err; | |
599 | } | |
600 | } | |
1da177e4 LT |
601 | |
602 | if (nlk->pid) { | |
603 | if (nladdr->nl_pid != nlk->pid) | |
604 | return -EINVAL; | |
605 | } else { | |
606 | err = nladdr->nl_pid ? | |
607 | netlink_insert(sk, nladdr->nl_pid) : | |
608 | netlink_autobind(sock); | |
609 | if (err) | |
610 | return err; | |
611 | } | |
612 | ||
513c2500 | 613 | if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
1da177e4 LT |
614 | return 0; |
615 | ||
616 | netlink_table_grab(); | |
f7fa9b10 | 617 | netlink_update_subscriptions(sk, nlk->subscriptions + |
746fac4d YH |
618 | hweight32(nladdr->nl_groups) - |
619 | hweight32(nlk->groups[0])); | |
620 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups; | |
4277a083 | 621 | netlink_update_listeners(sk); |
1da177e4 LT |
622 | netlink_table_ungrab(); |
623 | ||
624 | return 0; | |
625 | } | |
626 | ||
627 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
628 | int alen, int flags) | |
629 | { | |
630 | int err = 0; | |
631 | struct sock *sk = sock->sk; | |
632 | struct netlink_sock *nlk = nlk_sk(sk); | |
633 | struct sockaddr_nl *nladdr=(struct sockaddr_nl*)addr; | |
634 | ||
635 | if (addr->sa_family == AF_UNSPEC) { | |
636 | sk->sk_state = NETLINK_UNCONNECTED; | |
637 | nlk->dst_pid = 0; | |
d629b836 | 638 | nlk->dst_group = 0; |
1da177e4 LT |
639 | return 0; |
640 | } | |
641 | if (addr->sa_family != AF_NETLINK) | |
642 | return -EINVAL; | |
643 | ||
644 | /* Only superuser is allowed to send multicasts */ | |
645 | if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND)) | |
646 | return -EPERM; | |
647 | ||
648 | if (!nlk->pid) | |
649 | err = netlink_autobind(sock); | |
650 | ||
651 | if (err == 0) { | |
652 | sk->sk_state = NETLINK_CONNECTED; | |
653 | nlk->dst_pid = nladdr->nl_pid; | |
d629b836 | 654 | nlk->dst_group = ffs(nladdr->nl_groups); |
1da177e4 LT |
655 | } |
656 | ||
657 | return err; | |
658 | } | |
659 | ||
660 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, int *addr_len, int peer) | |
661 | { | |
662 | struct sock *sk = sock->sk; | |
663 | struct netlink_sock *nlk = nlk_sk(sk); | |
664 | struct sockaddr_nl *nladdr=(struct sockaddr_nl *)addr; | |
746fac4d | 665 | |
1da177e4 LT |
666 | nladdr->nl_family = AF_NETLINK; |
667 | nladdr->nl_pad = 0; | |
668 | *addr_len = sizeof(*nladdr); | |
669 | ||
670 | if (peer) { | |
671 | nladdr->nl_pid = nlk->dst_pid; | |
d629b836 | 672 | nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
1da177e4 LT |
673 | } else { |
674 | nladdr->nl_pid = nlk->pid; | |
513c2500 | 675 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
1da177e4 LT |
676 | } |
677 | return 0; | |
678 | } | |
679 | ||
680 | static void netlink_overrun(struct sock *sk) | |
681 | { | |
682 | if (!test_and_set_bit(0, &nlk_sk(sk)->state)) { | |
683 | sk->sk_err = ENOBUFS; | |
684 | sk->sk_error_report(sk); | |
685 | } | |
686 | } | |
687 | ||
688 | static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid) | |
689 | { | |
690 | int protocol = ssk->sk_protocol; | |
691 | struct sock *sock; | |
692 | struct netlink_sock *nlk; | |
693 | ||
694 | sock = netlink_lookup(protocol, pid); | |
695 | if (!sock) | |
696 | return ERR_PTR(-ECONNREFUSED); | |
697 | ||
698 | /* Don't bother queuing skb if kernel socket has no input function */ | |
699 | nlk = nlk_sk(sock); | |
700 | if ((nlk->pid == 0 && !nlk->data_ready) || | |
701 | (sock->sk_state == NETLINK_CONNECTED && | |
702 | nlk->dst_pid != nlk_sk(ssk)->pid)) { | |
703 | sock_put(sock); | |
704 | return ERR_PTR(-ECONNREFUSED); | |
705 | } | |
706 | return sock; | |
707 | } | |
708 | ||
709 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
710 | { | |
6db5fc5d | 711 | struct inode *inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
712 | struct sock *sock; |
713 | ||
714 | if (!S_ISSOCK(inode->i_mode)) | |
715 | return ERR_PTR(-ENOTSOCK); | |
716 | ||
717 | sock = SOCKET_I(inode)->sk; | |
718 | if (sock->sk_family != AF_NETLINK) | |
719 | return ERR_PTR(-EINVAL); | |
720 | ||
721 | sock_hold(sock); | |
722 | return sock; | |
723 | } | |
724 | ||
725 | /* | |
726 | * Attach a skb to a netlink socket. | |
727 | * The caller must hold a reference to the destination socket. On error, the | |
728 | * reference is dropped. The skb is not send to the destination, just all | |
729 | * all error checks are performed and memory in the queue is reserved. | |
730 | * Return values: | |
731 | * < 0: error. skb freed, reference to sock dropped. | |
732 | * 0: continue | |
733 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
734 | */ | |
a70ea994 AK |
735 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock, |
736 | long timeo, struct sock *ssk) | |
1da177e4 LT |
737 | { |
738 | struct netlink_sock *nlk; | |
739 | ||
740 | nlk = nlk_sk(sk); | |
741 | ||
742 | if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
743 | test_bit(0, &nlk->state)) { | |
744 | DECLARE_WAITQUEUE(wait, current); | |
745 | if (!timeo) { | |
a70ea994 | 746 | if (!ssk || nlk_sk(ssk)->pid == 0) |
1da177e4 LT |
747 | netlink_overrun(sk); |
748 | sock_put(sk); | |
749 | kfree_skb(skb); | |
750 | return -EAGAIN; | |
751 | } | |
752 | ||
753 | __set_current_state(TASK_INTERRUPTIBLE); | |
754 | add_wait_queue(&nlk->wait, &wait); | |
755 | ||
756 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
757 | test_bit(0, &nlk->state)) && | |
758 | !sock_flag(sk, SOCK_DEAD)) | |
759 | timeo = schedule_timeout(timeo); | |
760 | ||
761 | __set_current_state(TASK_RUNNING); | |
762 | remove_wait_queue(&nlk->wait, &wait); | |
763 | sock_put(sk); | |
764 | ||
765 | if (signal_pending(current)) { | |
766 | kfree_skb(skb); | |
767 | return sock_intr_errno(timeo); | |
768 | } | |
769 | return 1; | |
770 | } | |
771 | skb_set_owner_r(skb, sk); | |
772 | return 0; | |
773 | } | |
774 | ||
775 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb, int protocol) | |
776 | { | |
1da177e4 LT |
777 | int len = skb->len; |
778 | ||
1da177e4 LT |
779 | skb_queue_tail(&sk->sk_receive_queue, skb); |
780 | sk->sk_data_ready(sk, len); | |
781 | sock_put(sk); | |
782 | return len; | |
783 | } | |
784 | ||
785 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
786 | { | |
787 | kfree_skb(skb); | |
788 | sock_put(sk); | |
789 | } | |
790 | ||
37da647d | 791 | static inline struct sk_buff *netlink_trim(struct sk_buff *skb, |
dd0fc66f | 792 | gfp_t allocation) |
1da177e4 LT |
793 | { |
794 | int delta; | |
795 | ||
796 | skb_orphan(skb); | |
797 | ||
4305b541 | 798 | delta = skb->end - skb->tail; |
1da177e4 LT |
799 | if (delta * 2 < skb->truesize) |
800 | return skb; | |
801 | ||
802 | if (skb_shared(skb)) { | |
803 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
804 | if (!nskb) | |
805 | return skb; | |
806 | kfree_skb(skb); | |
807 | skb = nskb; | |
808 | } | |
809 | ||
810 | if (!pskb_expand_head(skb, 0, -delta, allocation)) | |
811 | skb->truesize -= delta; | |
812 | ||
813 | return skb; | |
814 | } | |
815 | ||
816 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, u32 pid, int nonblock) | |
817 | { | |
818 | struct sock *sk; | |
819 | int err; | |
820 | long timeo; | |
821 | ||
822 | skb = netlink_trim(skb, gfp_any()); | |
823 | ||
824 | timeo = sock_sndtimeo(ssk, nonblock); | |
825 | retry: | |
826 | sk = netlink_getsockbypid(ssk, pid); | |
827 | if (IS_ERR(sk)) { | |
828 | kfree_skb(skb); | |
829 | return PTR_ERR(sk); | |
830 | } | |
a70ea994 | 831 | err = netlink_attachskb(sk, skb, nonblock, timeo, ssk); |
1da177e4 LT |
832 | if (err == 1) |
833 | goto retry; | |
834 | if (err) | |
835 | return err; | |
836 | ||
837 | return netlink_sendskb(sk, skb, ssk->sk_protocol); | |
838 | } | |
839 | ||
4277a083 PM |
840 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
841 | { | |
842 | int res = 0; | |
843 | ||
844 | BUG_ON(!(nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET)); | |
845 | if (group - 1 < nl_table[sk->sk_protocol].groups) | |
846 | res = test_bit(group - 1, nl_table[sk->sk_protocol].listeners); | |
847 | return res; | |
848 | } | |
849 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
850 | ||
1da177e4 LT |
851 | static __inline__ int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) |
852 | { | |
853 | struct netlink_sock *nlk = nlk_sk(sk); | |
854 | ||
855 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
856 | !test_bit(0, &nlk->state)) { | |
857 | skb_set_owner_r(skb, sk); | |
858 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
859 | sk->sk_data_ready(sk, skb->len); | |
860 | return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf; | |
861 | } | |
862 | return -1; | |
863 | } | |
864 | ||
865 | struct netlink_broadcast_data { | |
866 | struct sock *exclude_sk; | |
867 | u32 pid; | |
868 | u32 group; | |
869 | int failure; | |
870 | int congested; | |
871 | int delivered; | |
7d877f3b | 872 | gfp_t allocation; |
1da177e4 LT |
873 | struct sk_buff *skb, *skb2; |
874 | }; | |
875 | ||
876 | static inline int do_one_broadcast(struct sock *sk, | |
877 | struct netlink_broadcast_data *p) | |
878 | { | |
879 | struct netlink_sock *nlk = nlk_sk(sk); | |
880 | int val; | |
881 | ||
882 | if (p->exclude_sk == sk) | |
883 | goto out; | |
884 | ||
f7fa9b10 PM |
885 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
886 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
887 | goto out; |
888 | ||
889 | if (p->failure) { | |
890 | netlink_overrun(sk); | |
891 | goto out; | |
892 | } | |
893 | ||
894 | sock_hold(sk); | |
895 | if (p->skb2 == NULL) { | |
68acc024 | 896 | if (skb_shared(p->skb)) { |
1da177e4 LT |
897 | p->skb2 = skb_clone(p->skb, p->allocation); |
898 | } else { | |
68acc024 TC |
899 | p->skb2 = skb_get(p->skb); |
900 | /* | |
901 | * skb ownership may have been set when | |
902 | * delivered to a previous socket. | |
903 | */ | |
904 | skb_orphan(p->skb2); | |
1da177e4 LT |
905 | } |
906 | } | |
907 | if (p->skb2 == NULL) { | |
908 | netlink_overrun(sk); | |
909 | /* Clone failed. Notify ALL listeners. */ | |
910 | p->failure = 1; | |
911 | } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) { | |
912 | netlink_overrun(sk); | |
913 | } else { | |
914 | p->congested |= val; | |
915 | p->delivered = 1; | |
916 | p->skb2 = NULL; | |
917 | } | |
918 | sock_put(sk); | |
919 | ||
920 | out: | |
921 | return 0; | |
922 | } | |
923 | ||
924 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid, | |
dd0fc66f | 925 | u32 group, gfp_t allocation) |
1da177e4 LT |
926 | { |
927 | struct netlink_broadcast_data info; | |
928 | struct hlist_node *node; | |
929 | struct sock *sk; | |
930 | ||
931 | skb = netlink_trim(skb, allocation); | |
932 | ||
933 | info.exclude_sk = ssk; | |
934 | info.pid = pid; | |
935 | info.group = group; | |
936 | info.failure = 0; | |
937 | info.congested = 0; | |
938 | info.delivered = 0; | |
939 | info.allocation = allocation; | |
940 | info.skb = skb; | |
941 | info.skb2 = NULL; | |
942 | ||
943 | /* While we sleep in clone, do not allow to change socket list */ | |
944 | ||
945 | netlink_lock_table(); | |
946 | ||
947 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
948 | do_one_broadcast(sk, &info); | |
949 | ||
aa1c6a6f TC |
950 | kfree_skb(skb); |
951 | ||
1da177e4 LT |
952 | netlink_unlock_table(); |
953 | ||
954 | if (info.skb2) | |
955 | kfree_skb(info.skb2); | |
1da177e4 LT |
956 | |
957 | if (info.delivered) { | |
958 | if (info.congested && (allocation & __GFP_WAIT)) | |
959 | yield(); | |
960 | return 0; | |
961 | } | |
962 | if (info.failure) | |
963 | return -ENOBUFS; | |
964 | return -ESRCH; | |
965 | } | |
966 | ||
967 | struct netlink_set_err_data { | |
968 | struct sock *exclude_sk; | |
969 | u32 pid; | |
970 | u32 group; | |
971 | int code; | |
972 | }; | |
973 | ||
974 | static inline int do_one_set_err(struct sock *sk, | |
975 | struct netlink_set_err_data *p) | |
976 | { | |
977 | struct netlink_sock *nlk = nlk_sk(sk); | |
978 | ||
979 | if (sk == p->exclude_sk) | |
980 | goto out; | |
981 | ||
f7fa9b10 PM |
982 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
983 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
984 | goto out; |
985 | ||
986 | sk->sk_err = p->code; | |
987 | sk->sk_error_report(sk); | |
988 | out: | |
989 | return 0; | |
990 | } | |
991 | ||
992 | void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) | |
993 | { | |
994 | struct netlink_set_err_data info; | |
995 | struct hlist_node *node; | |
996 | struct sock *sk; | |
997 | ||
998 | info.exclude_sk = ssk; | |
999 | info.pid = pid; | |
1000 | info.group = group; | |
1001 | info.code = code; | |
1002 | ||
1003 | read_lock(&nl_table_lock); | |
1004 | ||
1005 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1006 | do_one_set_err(sk, &info); | |
1007 | ||
1008 | read_unlock(&nl_table_lock); | |
1009 | } | |
1010 | ||
9a4595bc | 1011 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
746fac4d | 1012 | char __user *optval, int optlen) |
9a4595bc PM |
1013 | { |
1014 | struct sock *sk = sock->sk; | |
1015 | struct netlink_sock *nlk = nlk_sk(sk); | |
1016 | int val = 0, err; | |
1017 | ||
1018 | if (level != SOL_NETLINK) | |
1019 | return -ENOPROTOOPT; | |
1020 | ||
1021 | if (optlen >= sizeof(int) && | |
1022 | get_user(val, (int __user *)optval)) | |
1023 | return -EFAULT; | |
1024 | ||
1025 | switch (optname) { | |
1026 | case NETLINK_PKTINFO: | |
1027 | if (val) | |
1028 | nlk->flags |= NETLINK_RECV_PKTINFO; | |
1029 | else | |
1030 | nlk->flags &= ~NETLINK_RECV_PKTINFO; | |
1031 | err = 0; | |
1032 | break; | |
1033 | case NETLINK_ADD_MEMBERSHIP: | |
1034 | case NETLINK_DROP_MEMBERSHIP: { | |
1035 | unsigned int subscriptions; | |
1036 | int old, new = optname == NETLINK_ADD_MEMBERSHIP ? 1 : 0; | |
1037 | ||
1038 | if (!netlink_capable(sock, NL_NONROOT_RECV)) | |
1039 | return -EPERM; | |
513c2500 PM |
1040 | if (nlk->groups == NULL) { |
1041 | err = netlink_alloc_groups(sk); | |
1042 | if (err) | |
1043 | return err; | |
1044 | } | |
9a4595bc PM |
1045 | if (!val || val - 1 >= nlk->ngroups) |
1046 | return -EINVAL; | |
1047 | netlink_table_grab(); | |
1048 | old = test_bit(val - 1, nlk->groups); | |
1049 | subscriptions = nlk->subscriptions - old + new; | |
1050 | if (new) | |
1051 | __set_bit(val - 1, nlk->groups); | |
1052 | else | |
1053 | __clear_bit(val - 1, nlk->groups); | |
1054 | netlink_update_subscriptions(sk, subscriptions); | |
4277a083 | 1055 | netlink_update_listeners(sk); |
9a4595bc PM |
1056 | netlink_table_ungrab(); |
1057 | err = 0; | |
1058 | break; | |
1059 | } | |
1060 | default: | |
1061 | err = -ENOPROTOOPT; | |
1062 | } | |
1063 | return err; | |
1064 | } | |
1065 | ||
1066 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
746fac4d | 1067 | char __user *optval, int __user *optlen) |
9a4595bc PM |
1068 | { |
1069 | struct sock *sk = sock->sk; | |
1070 | struct netlink_sock *nlk = nlk_sk(sk); | |
1071 | int len, val, err; | |
1072 | ||
1073 | if (level != SOL_NETLINK) | |
1074 | return -ENOPROTOOPT; | |
1075 | ||
1076 | if (get_user(len, optlen)) | |
1077 | return -EFAULT; | |
1078 | if (len < 0) | |
1079 | return -EINVAL; | |
1080 | ||
1081 | switch (optname) { | |
1082 | case NETLINK_PKTINFO: | |
1083 | if (len < sizeof(int)) | |
1084 | return -EINVAL; | |
1085 | len = sizeof(int); | |
1086 | val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0; | |
a27b58fe HC |
1087 | if (put_user(len, optlen) || |
1088 | put_user(val, optval)) | |
1089 | return -EFAULT; | |
9a4595bc PM |
1090 | err = 0; |
1091 | break; | |
1092 | default: | |
1093 | err = -ENOPROTOOPT; | |
1094 | } | |
1095 | return err; | |
1096 | } | |
1097 | ||
1098 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
1099 | { | |
1100 | struct nl_pktinfo info; | |
1101 | ||
1102 | info.group = NETLINK_CB(skb).dst_group; | |
1103 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
1104 | } | |
1105 | ||
1da177e4 LT |
1106 | static inline void netlink_rcv_wake(struct sock *sk) |
1107 | { | |
1108 | struct netlink_sock *nlk = nlk_sk(sk); | |
1109 | ||
b03efcfb | 1110 | if (skb_queue_empty(&sk->sk_receive_queue)) |
1da177e4 LT |
1111 | clear_bit(0, &nlk->state); |
1112 | if (!test_bit(0, &nlk->state)) | |
1113 | wake_up_interruptible(&nlk->wait); | |
1114 | } | |
1115 | ||
1116 | static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, | |
1117 | struct msghdr *msg, size_t len) | |
1118 | { | |
1119 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1120 | struct sock *sk = sock->sk; | |
1121 | struct netlink_sock *nlk = nlk_sk(sk); | |
1122 | struct sockaddr_nl *addr=msg->msg_name; | |
1123 | u32 dst_pid; | |
d629b836 | 1124 | u32 dst_group; |
1da177e4 LT |
1125 | struct sk_buff *skb; |
1126 | int err; | |
1127 | struct scm_cookie scm; | |
1128 | ||
1129 | if (msg->msg_flags&MSG_OOB) | |
1130 | return -EOPNOTSUPP; | |
1131 | ||
1132 | if (NULL == siocb->scm) | |
1133 | siocb->scm = &scm; | |
1134 | err = scm_send(sock, msg, siocb->scm); | |
1135 | if (err < 0) | |
1136 | return err; | |
1137 | ||
1138 | if (msg->msg_namelen) { | |
1139 | if (addr->nl_family != AF_NETLINK) | |
1140 | return -EINVAL; | |
1141 | dst_pid = addr->nl_pid; | |
d629b836 PM |
1142 | dst_group = ffs(addr->nl_groups); |
1143 | if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND)) | |
1da177e4 LT |
1144 | return -EPERM; |
1145 | } else { | |
1146 | dst_pid = nlk->dst_pid; | |
d629b836 | 1147 | dst_group = nlk->dst_group; |
1da177e4 LT |
1148 | } |
1149 | ||
1150 | if (!nlk->pid) { | |
1151 | err = netlink_autobind(sock); | |
1152 | if (err) | |
1153 | goto out; | |
1154 | } | |
1155 | ||
1156 | err = -EMSGSIZE; | |
1157 | if (len > sk->sk_sndbuf - 32) | |
1158 | goto out; | |
1159 | err = -ENOBUFS; | |
339bf98f | 1160 | skb = alloc_skb(len, GFP_KERNEL); |
1da177e4 LT |
1161 | if (skb==NULL) |
1162 | goto out; | |
1163 | ||
1164 | NETLINK_CB(skb).pid = nlk->pid; | |
d629b836 | 1165 | NETLINK_CB(skb).dst_group = dst_group; |
c94c257c | 1166 | NETLINK_CB(skb).loginuid = audit_get_loginuid(current->audit_context); |
e7c34970 | 1167 | selinux_get_task_sid(current, &(NETLINK_CB(skb).sid)); |
1da177e4 LT |
1168 | memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); |
1169 | ||
1170 | /* What can I do? Netlink is asynchronous, so that | |
1171 | we will have to save current capabilities to | |
1172 | check them, when this message will be delivered | |
1173 | to corresponding kernel module. --ANK (980802) | |
1174 | */ | |
1175 | ||
1176 | err = -EFAULT; | |
1177 | if (memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len)) { | |
1178 | kfree_skb(skb); | |
1179 | goto out; | |
1180 | } | |
1181 | ||
1182 | err = security_netlink_send(sk, skb); | |
1183 | if (err) { | |
1184 | kfree_skb(skb); | |
1185 | goto out; | |
1186 | } | |
1187 | ||
d629b836 | 1188 | if (dst_group) { |
1da177e4 | 1189 | atomic_inc(&skb->users); |
d629b836 | 1190 | netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL); |
1da177e4 LT |
1191 | } |
1192 | err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT); | |
1193 | ||
1194 | out: | |
1195 | return err; | |
1196 | } | |
1197 | ||
1198 | static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, | |
1199 | struct msghdr *msg, size_t len, | |
1200 | int flags) | |
1201 | { | |
1202 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1203 | struct scm_cookie scm; | |
1204 | struct sock *sk = sock->sk; | |
1205 | struct netlink_sock *nlk = nlk_sk(sk); | |
1206 | int noblock = flags&MSG_DONTWAIT; | |
1207 | size_t copied; | |
1208 | struct sk_buff *skb; | |
1209 | int err; | |
1210 | ||
1211 | if (flags&MSG_OOB) | |
1212 | return -EOPNOTSUPP; | |
1213 | ||
1214 | copied = 0; | |
1215 | ||
1216 | skb = skb_recv_datagram(sk,flags,noblock,&err); | |
1217 | if (skb==NULL) | |
1218 | goto out; | |
1219 | ||
1220 | msg->msg_namelen = 0; | |
1221 | ||
1222 | copied = skb->len; | |
1223 | if (len < copied) { | |
1224 | msg->msg_flags |= MSG_TRUNC; | |
1225 | copied = len; | |
1226 | } | |
1227 | ||
badff6d0 | 1228 | skb_reset_transport_header(skb); |
1da177e4 LT |
1229 | err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); |
1230 | ||
1231 | if (msg->msg_name) { | |
1232 | struct sockaddr_nl *addr = (struct sockaddr_nl*)msg->msg_name; | |
1233 | addr->nl_family = AF_NETLINK; | |
1234 | addr->nl_pad = 0; | |
1235 | addr->nl_pid = NETLINK_CB(skb).pid; | |
d629b836 | 1236 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
1237 | msg->msg_namelen = sizeof(*addr); |
1238 | } | |
1239 | ||
cc9a06cd PM |
1240 | if (nlk->flags & NETLINK_RECV_PKTINFO) |
1241 | netlink_cmsg_recv_pktinfo(msg, skb); | |
1242 | ||
1da177e4 LT |
1243 | if (NULL == siocb->scm) { |
1244 | memset(&scm, 0, sizeof(scm)); | |
1245 | siocb->scm = &scm; | |
1246 | } | |
1247 | siocb->scm->creds = *NETLINK_CREDS(skb); | |
1248 | skb_free_datagram(sk, skb); | |
1249 | ||
1250 | if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) | |
1251 | netlink_dump(sk); | |
1252 | ||
1253 | scm_recv(sock, msg, siocb->scm, flags); | |
1254 | ||
b558ff79 DM |
1255 | if (flags & MSG_TRUNC) |
1256 | copied = skb->len; | |
1257 | ||
1da177e4 LT |
1258 | out: |
1259 | netlink_rcv_wake(sk); | |
1260 | return err ? : copied; | |
1261 | } | |
1262 | ||
1263 | static void netlink_data_ready(struct sock *sk, int len) | |
1264 | { | |
1265 | struct netlink_sock *nlk = nlk_sk(sk); | |
1266 | ||
1267 | if (nlk->data_ready) | |
1268 | nlk->data_ready(sk, len); | |
1269 | netlink_rcv_wake(sk); | |
1270 | } | |
1271 | ||
1272 | /* | |
746fac4d | 1273 | * We export these functions to other modules. They provide a |
1da177e4 LT |
1274 | * complete set of kernel non-blocking support for message |
1275 | * queueing. | |
1276 | */ | |
1277 | ||
1278 | struct sock * | |
06628607 | 1279 | netlink_kernel_create(int unit, unsigned int groups, |
746fac4d | 1280 | void (*input)(struct sock *sk, int len), |
af65bdfc | 1281 | struct mutex *cb_mutex, struct module *module) |
1da177e4 LT |
1282 | { |
1283 | struct socket *sock; | |
1284 | struct sock *sk; | |
77247bbb | 1285 | struct netlink_sock *nlk; |
4277a083 | 1286 | unsigned long *listeners = NULL; |
1da177e4 | 1287 | |
fab2caf6 | 1288 | BUG_ON(!nl_table); |
1da177e4 LT |
1289 | |
1290 | if (unit<0 || unit>=MAX_LINKS) | |
1291 | return NULL; | |
1292 | ||
1293 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
1294 | return NULL; | |
1295 | ||
af65bdfc | 1296 | if (__netlink_create(sock, cb_mutex, unit) < 0) |
77247bbb | 1297 | goto out_sock_release; |
4fdb3bb7 | 1298 | |
4277a083 PM |
1299 | if (groups < 32) |
1300 | groups = 32; | |
1301 | ||
1302 | listeners = kzalloc(NLGRPSZ(groups), GFP_KERNEL); | |
1303 | if (!listeners) | |
1304 | goto out_sock_release; | |
1305 | ||
1da177e4 LT |
1306 | sk = sock->sk; |
1307 | sk->sk_data_ready = netlink_data_ready; | |
1308 | if (input) | |
1309 | nlk_sk(sk)->data_ready = input; | |
1310 | ||
77247bbb PM |
1311 | if (netlink_insert(sk, 0)) |
1312 | goto out_sock_release; | |
4fdb3bb7 | 1313 | |
77247bbb PM |
1314 | nlk = nlk_sk(sk); |
1315 | nlk->flags |= NETLINK_KERNEL_SOCKET; | |
4fdb3bb7 | 1316 | |
4fdb3bb7 | 1317 | netlink_table_grab(); |
4277a083 PM |
1318 | nl_table[unit].groups = groups; |
1319 | nl_table[unit].listeners = listeners; | |
af65bdfc | 1320 | nl_table[unit].cb_mutex = cb_mutex; |
77247bbb | 1321 | nl_table[unit].module = module; |
ab33a171 | 1322 | nl_table[unit].registered = 1; |
4fdb3bb7 | 1323 | netlink_table_ungrab(); |
77247bbb PM |
1324 | |
1325 | return sk; | |
1326 | ||
4fdb3bb7 | 1327 | out_sock_release: |
4277a083 | 1328 | kfree(listeners); |
4fdb3bb7 | 1329 | sock_release(sock); |
77247bbb | 1330 | return NULL; |
1da177e4 LT |
1331 | } |
1332 | ||
1333 | void netlink_set_nonroot(int protocol, unsigned int flags) | |
746fac4d YH |
1334 | { |
1335 | if ((unsigned int)protocol < MAX_LINKS) | |
1da177e4 | 1336 | nl_table[protocol].nl_nonroot = flags; |
746fac4d | 1337 | } |
1da177e4 LT |
1338 | |
1339 | static void netlink_destroy_callback(struct netlink_callback *cb) | |
1340 | { | |
1341 | if (cb->skb) | |
1342 | kfree_skb(cb->skb); | |
1343 | kfree(cb); | |
1344 | } | |
1345 | ||
1346 | /* | |
1347 | * It looks a bit ugly. | |
1348 | * It would be better to create kernel thread. | |
1349 | */ | |
1350 | ||
1351 | static int netlink_dump(struct sock *sk) | |
1352 | { | |
1353 | struct netlink_sock *nlk = nlk_sk(sk); | |
1354 | struct netlink_callback *cb; | |
1355 | struct sk_buff *skb; | |
1356 | struct nlmsghdr *nlh; | |
bf8b79e4 | 1357 | int len, err = -ENOBUFS; |
746fac4d | 1358 | |
1da177e4 LT |
1359 | skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL); |
1360 | if (!skb) | |
bf8b79e4 | 1361 | goto errout; |
1da177e4 | 1362 | |
af65bdfc | 1363 | mutex_lock(nlk->cb_mutex); |
1da177e4 LT |
1364 | |
1365 | cb = nlk->cb; | |
1366 | if (cb == NULL) { | |
bf8b79e4 TG |
1367 | err = -EINVAL; |
1368 | goto errout_skb; | |
1da177e4 LT |
1369 | } |
1370 | ||
1371 | len = cb->dump(skb, cb); | |
1372 | ||
1373 | if (len > 0) { | |
af65bdfc | 1374 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1375 | skb_queue_tail(&sk->sk_receive_queue, skb); |
1376 | sk->sk_data_ready(sk, len); | |
1377 | return 0; | |
1378 | } | |
1379 | ||
bf8b79e4 TG |
1380 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); |
1381 | if (!nlh) | |
1382 | goto errout_skb; | |
1383 | ||
1384 | memcpy(nlmsg_data(nlh), &len, sizeof(len)); | |
1385 | ||
1da177e4 LT |
1386 | skb_queue_tail(&sk->sk_receive_queue, skb); |
1387 | sk->sk_data_ready(sk, skb->len); | |
1388 | ||
a8f74b22 TG |
1389 | if (cb->done) |
1390 | cb->done(cb); | |
1da177e4 | 1391 | nlk->cb = NULL; |
af65bdfc | 1392 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1393 | |
1394 | netlink_destroy_callback(cb); | |
1da177e4 | 1395 | return 0; |
1797754e | 1396 | |
bf8b79e4 | 1397 | errout_skb: |
af65bdfc | 1398 | mutex_unlock(nlk->cb_mutex); |
bf8b79e4 TG |
1399 | kfree_skb(skb); |
1400 | errout: | |
1401 | return err; | |
1da177e4 LT |
1402 | } |
1403 | ||
1404 | int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, | |
1405 | struct nlmsghdr *nlh, | |
1406 | int (*dump)(struct sk_buff *skb, struct netlink_callback*), | |
1407 | int (*done)(struct netlink_callback*)) | |
1408 | { | |
1409 | struct netlink_callback *cb; | |
1410 | struct sock *sk; | |
1411 | struct netlink_sock *nlk; | |
1412 | ||
0da974f4 | 1413 | cb = kzalloc(sizeof(*cb), GFP_KERNEL); |
1da177e4 LT |
1414 | if (cb == NULL) |
1415 | return -ENOBUFS; | |
1416 | ||
1da177e4 LT |
1417 | cb->dump = dump; |
1418 | cb->done = done; | |
1419 | cb->nlh = nlh; | |
1420 | atomic_inc(&skb->users); | |
1421 | cb->skb = skb; | |
1422 | ||
1423 | sk = netlink_lookup(ssk->sk_protocol, NETLINK_CB(skb).pid); | |
1424 | if (sk == NULL) { | |
1425 | netlink_destroy_callback(cb); | |
1426 | return -ECONNREFUSED; | |
1427 | } | |
1428 | nlk = nlk_sk(sk); | |
ac57b3a9 | 1429 | /* A dump or destruction is in progress... */ |
af65bdfc | 1430 | mutex_lock(nlk->cb_mutex); |
ac57b3a9 | 1431 | if (nlk->cb || sock_flag(sk, SOCK_DEAD)) { |
af65bdfc | 1432 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1433 | netlink_destroy_callback(cb); |
1434 | sock_put(sk); | |
1435 | return -EBUSY; | |
1436 | } | |
1437 | nlk->cb = cb; | |
af65bdfc | 1438 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1439 | |
1440 | netlink_dump(sk); | |
1441 | sock_put(sk); | |
c702e804 TG |
1442 | |
1443 | /* We successfully started a dump, by returning -EINTR we | |
1444 | * signal the queue mangement to interrupt processing of | |
1445 | * any netlink messages so userspace gets a chance to read | |
1446 | * the results. */ | |
1447 | return -EINTR; | |
1da177e4 LT |
1448 | } |
1449 | ||
1450 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) | |
1451 | { | |
1452 | struct sk_buff *skb; | |
1453 | struct nlmsghdr *rep; | |
1454 | struct nlmsgerr *errmsg; | |
339bf98f | 1455 | size_t payload = sizeof(*errmsg); |
1da177e4 | 1456 | |
339bf98f TG |
1457 | /* error messages get the original request appened */ |
1458 | if (err) | |
1459 | payload += nlmsg_len(nlh); | |
1da177e4 | 1460 | |
339bf98f | 1461 | skb = nlmsg_new(payload, GFP_KERNEL); |
1da177e4 LT |
1462 | if (!skb) { |
1463 | struct sock *sk; | |
1464 | ||
1465 | sk = netlink_lookup(in_skb->sk->sk_protocol, | |
1466 | NETLINK_CB(in_skb).pid); | |
1467 | if (sk) { | |
1468 | sk->sk_err = ENOBUFS; | |
1469 | sk->sk_error_report(sk); | |
1470 | sock_put(sk); | |
1471 | } | |
1472 | return; | |
1473 | } | |
1474 | ||
1475 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, | |
1797754e | 1476 | NLMSG_ERROR, sizeof(struct nlmsgerr), 0); |
bf8b79e4 | 1477 | errmsg = nlmsg_data(rep); |
1da177e4 | 1478 | errmsg->error = err; |
bf8b79e4 | 1479 | memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh)); |
1da177e4 LT |
1480 | netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT); |
1481 | } | |
1482 | ||
82ace47a | 1483 | static int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
1d00a4eb | 1484 | struct nlmsghdr *)) |
82ace47a | 1485 | { |
82ace47a TG |
1486 | struct nlmsghdr *nlh; |
1487 | int err; | |
1488 | ||
1489 | while (skb->len >= nlmsg_total_size(0)) { | |
b529ccf2 | 1490 | nlh = nlmsg_hdr(skb); |
d35b6856 | 1491 | err = 0; |
82ace47a | 1492 | |
ad8e4b75 | 1493 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
1494 | return 0; |
1495 | ||
d35b6856 TG |
1496 | /* Only requests are handled by the kernel */ |
1497 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | |
1498 | goto skip; | |
45e7ae7f TG |
1499 | |
1500 | /* Skip control messages */ | |
1501 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | |
1502 | goto skip; | |
d35b6856 | 1503 | |
1d00a4eb TG |
1504 | err = cb(skb, nlh); |
1505 | if (err == -EINTR) { | |
1506 | /* Not an error, but we interrupt processing */ | |
1507 | netlink_queue_skip(nlh, skb); | |
1508 | return err; | |
d35b6856 TG |
1509 | } |
1510 | skip: | |
1511 | if (nlh->nlmsg_flags & NLM_F_ACK || err) | |
82ace47a | 1512 | netlink_ack(skb, nlh, err); |
82ace47a | 1513 | |
bf8b79e4 | 1514 | netlink_queue_skip(nlh, skb); |
82ace47a TG |
1515 | } |
1516 | ||
1517 | return 0; | |
1518 | } | |
1519 | ||
1520 | /** | |
1521 | * nelink_run_queue - Process netlink receive queue. | |
1522 | * @sk: Netlink socket containing the queue | |
1523 | * @qlen: Place to store queue length upon entry | |
1524 | * @cb: Callback function invoked for each netlink message found | |
1525 | * | |
1526 | * Processes as much as there was in the queue upon entry and invokes | |
1527 | * a callback function for each netlink message found. The callback | |
1528 | * function may refuse a message by returning a negative error code | |
1529 | * but setting the error pointer to 0 in which case this function | |
1530 | * returns with a qlen != 0. | |
1531 | * | |
1532 | * qlen must be initialized to 0 before the initial entry, afterwards | |
1533 | * the function may be called repeatedly until qlen reaches 0. | |
1d00a4eb TG |
1534 | * |
1535 | * The callback function may return -EINTR to signal that processing | |
1536 | * of netlink messages shall be interrupted. In this case the message | |
1537 | * currently being processed will NOT be requeued onto the receive | |
1538 | * queue. | |
82ace47a TG |
1539 | */ |
1540 | void netlink_run_queue(struct sock *sk, unsigned int *qlen, | |
1d00a4eb | 1541 | int (*cb)(struct sk_buff *, struct nlmsghdr *)) |
82ace47a TG |
1542 | { |
1543 | struct sk_buff *skb; | |
1544 | ||
1545 | if (!*qlen || *qlen > skb_queue_len(&sk->sk_receive_queue)) | |
1546 | *qlen = skb_queue_len(&sk->sk_receive_queue); | |
1547 | ||
1548 | for (; *qlen; (*qlen)--) { | |
1549 | skb = skb_dequeue(&sk->sk_receive_queue); | |
1550 | if (netlink_rcv_skb(skb, cb)) { | |
1551 | if (skb->len) | |
1552 | skb_queue_head(&sk->sk_receive_queue, skb); | |
1553 | else { | |
1554 | kfree_skb(skb); | |
1555 | (*qlen)--; | |
1556 | } | |
1557 | break; | |
1558 | } | |
1559 | ||
1560 | kfree_skb(skb); | |
1561 | } | |
1562 | } | |
1563 | ||
1564 | /** | |
1565 | * netlink_queue_skip - Skip netlink message while processing queue. | |
1566 | * @nlh: Netlink message to be skipped | |
1567 | * @skb: Socket buffer containing the netlink messages. | |
1568 | * | |
1569 | * Pulls the given netlink message off the socket buffer so the next | |
1570 | * call to netlink_queue_run() will not reconsider the message. | |
1571 | */ | |
42bad1da | 1572 | static void netlink_queue_skip(struct nlmsghdr *nlh, struct sk_buff *skb) |
82ace47a TG |
1573 | { |
1574 | int msglen = NLMSG_ALIGN(nlh->nlmsg_len); | |
1575 | ||
1576 | if (msglen > skb->len) | |
1577 | msglen = skb->len; | |
1578 | ||
1579 | skb_pull(skb, msglen); | |
1580 | } | |
1da177e4 | 1581 | |
d387f6ad TG |
1582 | /** |
1583 | * nlmsg_notify - send a notification netlink message | |
1584 | * @sk: netlink socket to use | |
1585 | * @skb: notification message | |
1586 | * @pid: destination netlink pid for reports or 0 | |
1587 | * @group: destination multicast group or 0 | |
1588 | * @report: 1 to report back, 0 to disable | |
1589 | * @flags: allocation flags | |
1590 | */ | |
1591 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid, | |
1592 | unsigned int group, int report, gfp_t flags) | |
1593 | { | |
1594 | int err = 0; | |
1595 | ||
1596 | if (group) { | |
1597 | int exclude_pid = 0; | |
1598 | ||
1599 | if (report) { | |
1600 | atomic_inc(&skb->users); | |
1601 | exclude_pid = pid; | |
1602 | } | |
1603 | ||
1604 | /* errors reported via destination sk->sk_err */ | |
1605 | nlmsg_multicast(sk, skb, exclude_pid, group, flags); | |
1606 | } | |
1607 | ||
1608 | if (report) | |
1609 | err = nlmsg_unicast(sk, skb, pid); | |
1610 | ||
1611 | return err; | |
1612 | } | |
1613 | ||
1da177e4 LT |
1614 | #ifdef CONFIG_PROC_FS |
1615 | struct nl_seq_iter { | |
1616 | int link; | |
1617 | int hash_idx; | |
1618 | }; | |
1619 | ||
1620 | static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) | |
1621 | { | |
1622 | struct nl_seq_iter *iter = seq->private; | |
1623 | int i, j; | |
1624 | struct sock *s; | |
1625 | struct hlist_node *node; | |
1626 | loff_t off = 0; | |
1627 | ||
1628 | for (i=0; i<MAX_LINKS; i++) { | |
1629 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1630 | ||
1631 | for (j = 0; j <= hash->mask; j++) { | |
1632 | sk_for_each(s, node, &hash->table[j]) { | |
1633 | if (off == pos) { | |
1634 | iter->link = i; | |
1635 | iter->hash_idx = j; | |
1636 | return s; | |
1637 | } | |
1638 | ++off; | |
1639 | } | |
1640 | } | |
1641 | } | |
1642 | return NULL; | |
1643 | } | |
1644 | ||
1645 | static void *netlink_seq_start(struct seq_file *seq, loff_t *pos) | |
1646 | { | |
1647 | read_lock(&nl_table_lock); | |
1648 | return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
1649 | } | |
1650 | ||
1651 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
1652 | { | |
1653 | struct sock *s; | |
1654 | struct nl_seq_iter *iter; | |
1655 | int i, j; | |
1656 | ||
1657 | ++*pos; | |
1658 | ||
1659 | if (v == SEQ_START_TOKEN) | |
1660 | return netlink_seq_socket_idx(seq, 0); | |
746fac4d | 1661 | |
1da177e4 LT |
1662 | s = sk_next(v); |
1663 | if (s) | |
1664 | return s; | |
1665 | ||
1666 | iter = seq->private; | |
1667 | i = iter->link; | |
1668 | j = iter->hash_idx + 1; | |
1669 | ||
1670 | do { | |
1671 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1672 | ||
1673 | for (; j <= hash->mask; j++) { | |
1674 | s = sk_head(&hash->table[j]); | |
1675 | if (s) { | |
1676 | iter->link = i; | |
1677 | iter->hash_idx = j; | |
1678 | return s; | |
1679 | } | |
1680 | } | |
1681 | ||
1682 | j = 0; | |
1683 | } while (++i < MAX_LINKS); | |
1684 | ||
1685 | return NULL; | |
1686 | } | |
1687 | ||
1688 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
1689 | { | |
1690 | read_unlock(&nl_table_lock); | |
1691 | } | |
1692 | ||
1693 | ||
1694 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
1695 | { | |
1696 | if (v == SEQ_START_TOKEN) | |
1697 | seq_puts(seq, | |
1698 | "sk Eth Pid Groups " | |
1699 | "Rmem Wmem Dump Locks\n"); | |
1700 | else { | |
1701 | struct sock *s = v; | |
1702 | struct netlink_sock *nlk = nlk_sk(s); | |
1703 | ||
1704 | seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %d\n", | |
1705 | s, | |
1706 | s->sk_protocol, | |
1707 | nlk->pid, | |
513c2500 | 1708 | nlk->groups ? (u32)nlk->groups[0] : 0, |
1da177e4 LT |
1709 | atomic_read(&s->sk_rmem_alloc), |
1710 | atomic_read(&s->sk_wmem_alloc), | |
1711 | nlk->cb, | |
1712 | atomic_read(&s->sk_refcnt) | |
1713 | ); | |
1714 | ||
1715 | } | |
1716 | return 0; | |
1717 | } | |
1718 | ||
1719 | static struct seq_operations netlink_seq_ops = { | |
1720 | .start = netlink_seq_start, | |
1721 | .next = netlink_seq_next, | |
1722 | .stop = netlink_seq_stop, | |
1723 | .show = netlink_seq_show, | |
1724 | }; | |
1725 | ||
1726 | ||
1727 | static int netlink_seq_open(struct inode *inode, struct file *file) | |
1728 | { | |
1729 | struct seq_file *seq; | |
1730 | struct nl_seq_iter *iter; | |
1731 | int err; | |
1732 | ||
0da974f4 | 1733 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1da177e4 LT |
1734 | if (!iter) |
1735 | return -ENOMEM; | |
1736 | ||
1737 | err = seq_open(file, &netlink_seq_ops); | |
1738 | if (err) { | |
1739 | kfree(iter); | |
1740 | return err; | |
1741 | } | |
1742 | ||
1da177e4 LT |
1743 | seq = file->private_data; |
1744 | seq->private = iter; | |
1745 | return 0; | |
1746 | } | |
1747 | ||
da7071d7 | 1748 | static const struct file_operations netlink_seq_fops = { |
1da177e4 LT |
1749 | .owner = THIS_MODULE, |
1750 | .open = netlink_seq_open, | |
1751 | .read = seq_read, | |
1752 | .llseek = seq_lseek, | |
1753 | .release = seq_release_private, | |
1754 | }; | |
1755 | ||
1756 | #endif | |
1757 | ||
1758 | int netlink_register_notifier(struct notifier_block *nb) | |
1759 | { | |
e041c683 | 1760 | return atomic_notifier_chain_register(&netlink_chain, nb); |
1da177e4 LT |
1761 | } |
1762 | ||
1763 | int netlink_unregister_notifier(struct notifier_block *nb) | |
1764 | { | |
e041c683 | 1765 | return atomic_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 | 1766 | } |
746fac4d | 1767 | |
90ddc4f0 | 1768 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
1769 | .family = PF_NETLINK, |
1770 | .owner = THIS_MODULE, | |
1771 | .release = netlink_release, | |
1772 | .bind = netlink_bind, | |
1773 | .connect = netlink_connect, | |
1774 | .socketpair = sock_no_socketpair, | |
1775 | .accept = sock_no_accept, | |
1776 | .getname = netlink_getname, | |
1777 | .poll = datagram_poll, | |
1778 | .ioctl = sock_no_ioctl, | |
1779 | .listen = sock_no_listen, | |
1780 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
1781 | .setsockopt = netlink_setsockopt, |
1782 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
1783 | .sendmsg = netlink_sendmsg, |
1784 | .recvmsg = netlink_recvmsg, | |
1785 | .mmap = sock_no_mmap, | |
1786 | .sendpage = sock_no_sendpage, | |
1787 | }; | |
1788 | ||
1789 | static struct net_proto_family netlink_family_ops = { | |
1790 | .family = PF_NETLINK, | |
1791 | .create = netlink_create, | |
1792 | .owner = THIS_MODULE, /* for consistency 8) */ | |
1793 | }; | |
1794 | ||
1da177e4 LT |
1795 | static int __init netlink_proto_init(void) |
1796 | { | |
1797 | struct sk_buff *dummy_skb; | |
1798 | int i; | |
1799 | unsigned long max; | |
1800 | unsigned int order; | |
1801 | int err = proto_register(&netlink_proto, 0); | |
1802 | ||
1803 | if (err != 0) | |
1804 | goto out; | |
1805 | ||
ef047f5e | 1806 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb)); |
1da177e4 | 1807 | |
0da974f4 | 1808 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
1809 | if (!nl_table) |
1810 | goto panic; | |
1da177e4 | 1811 | |
1da177e4 LT |
1812 | if (num_physpages >= (128 * 1024)) |
1813 | max = num_physpages >> (21 - PAGE_SHIFT); | |
1814 | else | |
1815 | max = num_physpages >> (23 - PAGE_SHIFT); | |
1816 | ||
1817 | order = get_bitmask_order(max) - 1 + PAGE_SHIFT; | |
1818 | max = (1UL << order) / sizeof(struct hlist_head); | |
1819 | order = get_bitmask_order(max > UINT_MAX ? UINT_MAX : max) - 1; | |
1820 | ||
1821 | for (i = 0; i < MAX_LINKS; i++) { | |
1822 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1823 | ||
1824 | hash->table = nl_pid_hash_alloc(1 * sizeof(*hash->table)); | |
1825 | if (!hash->table) { | |
1826 | while (i-- > 0) | |
1827 | nl_pid_hash_free(nl_table[i].hash.table, | |
1828 | 1 * sizeof(*hash->table)); | |
1829 | kfree(nl_table); | |
fab2caf6 | 1830 | goto panic; |
1da177e4 LT |
1831 | } |
1832 | memset(hash->table, 0, 1 * sizeof(*hash->table)); | |
1833 | hash->max_shift = order; | |
1834 | hash->shift = 0; | |
1835 | hash->mask = 0; | |
1836 | hash->rehash_time = jiffies; | |
1837 | } | |
1838 | ||
1839 | sock_register(&netlink_family_ops); | |
1840 | #ifdef CONFIG_PROC_FS | |
1841 | proc_net_fops_create("netlink", 0, &netlink_seq_fops); | |
1842 | #endif | |
746fac4d | 1843 | /* The netlink device handler may be needed early. */ |
1da177e4 LT |
1844 | rtnetlink_init(); |
1845 | out: | |
1846 | return err; | |
fab2caf6 AM |
1847 | panic: |
1848 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
1849 | } |
1850 | ||
1da177e4 | 1851 | core_initcall(netlink_proto_init); |
1da177e4 LT |
1852 | |
1853 | EXPORT_SYMBOL(netlink_ack); | |
82ace47a | 1854 | EXPORT_SYMBOL(netlink_run_queue); |
1da177e4 LT |
1855 | EXPORT_SYMBOL(netlink_broadcast); |
1856 | EXPORT_SYMBOL(netlink_dump_start); | |
1857 | EXPORT_SYMBOL(netlink_kernel_create); | |
1858 | EXPORT_SYMBOL(netlink_register_notifier); | |
1da177e4 LT |
1859 | EXPORT_SYMBOL(netlink_set_nonroot); |
1860 | EXPORT_SYMBOL(netlink_unicast); | |
1861 | EXPORT_SYMBOL(netlink_unregister_notifier); | |
d387f6ad | 1862 | EXPORT_SYMBOL(nlmsg_notify); |