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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * NETLINK Kernel-user communication protocol. | |
3 | * | |
4 | * Authors: Alan Cox <alan@redhat.com> | |
5 | * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
11 | * | |
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) | |
16 | * | |
17 | */ | |
18 | ||
19 | #include <linux/config.h> | |
20 | #include <linux/module.h> | |
21 | ||
22 | #include <linux/kernel.h> | |
23 | #include <linux/init.h> | |
24 | #include <linux/major.h> | |
25 | #include <linux/signal.h> | |
26 | #include <linux/sched.h> | |
27 | #include <linux/errno.h> | |
28 | #include <linux/string.h> | |
29 | #include <linux/stat.h> | |
30 | #include <linux/socket.h> | |
31 | #include <linux/un.h> | |
32 | #include <linux/fcntl.h> | |
33 | #include <linux/termios.h> | |
34 | #include <linux/sockios.h> | |
35 | #include <linux/net.h> | |
36 | #include <linux/fs.h> | |
37 | #include <linux/slab.h> | |
38 | #include <asm/uaccess.h> | |
39 | #include <linux/skbuff.h> | |
40 | #include <linux/netdevice.h> | |
41 | #include <linux/rtnetlink.h> | |
42 | #include <linux/proc_fs.h> | |
43 | #include <linux/seq_file.h> | |
44 | #include <linux/smp_lock.h> | |
45 | #include <linux/notifier.h> | |
46 | #include <linux/security.h> | |
47 | #include <linux/jhash.h> | |
48 | #include <linux/jiffies.h> | |
49 | #include <linux/random.h> | |
50 | #include <linux/bitops.h> | |
51 | #include <linux/mm.h> | |
52 | #include <linux/types.h> | |
53 | #include <net/sock.h> | |
54 | #include <net/scm.h> | |
55 | ||
56 | #define Nprintk(a...) | |
57 | ||
58 | struct netlink_sock { | |
59 | /* struct sock has to be the first member of netlink_sock */ | |
60 | struct sock sk; | |
61 | u32 pid; | |
62 | unsigned int groups; | |
63 | u32 dst_pid; | |
64 | unsigned int dst_groups; | |
65 | unsigned long state; | |
66 | wait_queue_head_t wait; | |
67 | struct netlink_callback *cb; | |
68 | spinlock_t cb_lock; | |
69 | void (*data_ready)(struct sock *sk, int bytes); | |
70 | }; | |
71 | ||
72 | static inline struct netlink_sock *nlk_sk(struct sock *sk) | |
73 | { | |
74 | return (struct netlink_sock *)sk; | |
75 | } | |
76 | ||
77 | struct nl_pid_hash { | |
78 | struct hlist_head *table; | |
79 | unsigned long rehash_time; | |
80 | ||
81 | unsigned int mask; | |
82 | unsigned int shift; | |
83 | ||
84 | unsigned int entries; | |
85 | unsigned int max_shift; | |
86 | ||
87 | u32 rnd; | |
88 | }; | |
89 | ||
90 | struct netlink_table { | |
91 | struct nl_pid_hash hash; | |
92 | struct hlist_head mc_list; | |
93 | unsigned int nl_nonroot; | |
94 | }; | |
95 | ||
96 | static struct netlink_table *nl_table; | |
97 | ||
98 | static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); | |
99 | ||
100 | static int netlink_dump(struct sock *sk); | |
101 | static void netlink_destroy_callback(struct netlink_callback *cb); | |
102 | ||
103 | static DEFINE_RWLOCK(nl_table_lock); | |
104 | static atomic_t nl_table_users = ATOMIC_INIT(0); | |
105 | ||
106 | static struct notifier_block *netlink_chain; | |
107 | ||
108 | static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid) | |
109 | { | |
110 | return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask]; | |
111 | } | |
112 | ||
113 | static void netlink_sock_destruct(struct sock *sk) | |
114 | { | |
115 | skb_queue_purge(&sk->sk_receive_queue); | |
116 | ||
117 | if (!sock_flag(sk, SOCK_DEAD)) { | |
118 | printk("Freeing alive netlink socket %p\n", sk); | |
119 | return; | |
120 | } | |
121 | BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc)); | |
122 | BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc)); | |
123 | BUG_TRAP(!nlk_sk(sk)->cb); | |
124 | } | |
125 | ||
126 | /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on SMP. | |
127 | * Look, when several writers sleep and reader wakes them up, all but one | |
128 | * immediately hit write lock and grab all the cpus. Exclusive sleep solves | |
129 | * this, _but_ remember, it adds useless work on UP machines. | |
130 | */ | |
131 | ||
132 | static void netlink_table_grab(void) | |
133 | { | |
134 | write_lock_bh(&nl_table_lock); | |
135 | ||
136 | if (atomic_read(&nl_table_users)) { | |
137 | DECLARE_WAITQUEUE(wait, current); | |
138 | ||
139 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
140 | for(;;) { | |
141 | set_current_state(TASK_UNINTERRUPTIBLE); | |
142 | if (atomic_read(&nl_table_users) == 0) | |
143 | break; | |
144 | write_unlock_bh(&nl_table_lock); | |
145 | schedule(); | |
146 | write_lock_bh(&nl_table_lock); | |
147 | } | |
148 | ||
149 | __set_current_state(TASK_RUNNING); | |
150 | remove_wait_queue(&nl_table_wait, &wait); | |
151 | } | |
152 | } | |
153 | ||
154 | static __inline__ void netlink_table_ungrab(void) | |
155 | { | |
156 | write_unlock_bh(&nl_table_lock); | |
157 | wake_up(&nl_table_wait); | |
158 | } | |
159 | ||
160 | static __inline__ void | |
161 | netlink_lock_table(void) | |
162 | { | |
163 | /* read_lock() synchronizes us to netlink_table_grab */ | |
164 | ||
165 | read_lock(&nl_table_lock); | |
166 | atomic_inc(&nl_table_users); | |
167 | read_unlock(&nl_table_lock); | |
168 | } | |
169 | ||
170 | static __inline__ void | |
171 | netlink_unlock_table(void) | |
172 | { | |
173 | if (atomic_dec_and_test(&nl_table_users)) | |
174 | wake_up(&nl_table_wait); | |
175 | } | |
176 | ||
177 | static __inline__ struct sock *netlink_lookup(int protocol, u32 pid) | |
178 | { | |
179 | struct nl_pid_hash *hash = &nl_table[protocol].hash; | |
180 | struct hlist_head *head; | |
181 | struct sock *sk; | |
182 | struct hlist_node *node; | |
183 | ||
184 | read_lock(&nl_table_lock); | |
185 | head = nl_pid_hashfn(hash, pid); | |
186 | sk_for_each(sk, node, head) { | |
187 | if (nlk_sk(sk)->pid == pid) { | |
188 | sock_hold(sk); | |
189 | goto found; | |
190 | } | |
191 | } | |
192 | sk = NULL; | |
193 | found: | |
194 | read_unlock(&nl_table_lock); | |
195 | return sk; | |
196 | } | |
197 | ||
198 | static inline struct hlist_head *nl_pid_hash_alloc(size_t size) | |
199 | { | |
200 | if (size <= PAGE_SIZE) | |
201 | return kmalloc(size, GFP_ATOMIC); | |
202 | else | |
203 | return (struct hlist_head *) | |
204 | __get_free_pages(GFP_ATOMIC, get_order(size)); | |
205 | } | |
206 | ||
207 | static inline void nl_pid_hash_free(struct hlist_head *table, size_t size) | |
208 | { | |
209 | if (size <= PAGE_SIZE) | |
210 | kfree(table); | |
211 | else | |
212 | free_pages((unsigned long)table, get_order(size)); | |
213 | } | |
214 | ||
215 | static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow) | |
216 | { | |
217 | unsigned int omask, mask, shift; | |
218 | size_t osize, size; | |
219 | struct hlist_head *otable, *table; | |
220 | int i; | |
221 | ||
222 | omask = mask = hash->mask; | |
223 | osize = size = (mask + 1) * sizeof(*table); | |
224 | shift = hash->shift; | |
225 | ||
226 | if (grow) { | |
227 | if (++shift > hash->max_shift) | |
228 | return 0; | |
229 | mask = mask * 2 + 1; | |
230 | size *= 2; | |
231 | } | |
232 | ||
233 | table = nl_pid_hash_alloc(size); | |
234 | if (!table) | |
235 | return 0; | |
236 | ||
237 | memset(table, 0, size); | |
238 | otable = hash->table; | |
239 | hash->table = table; | |
240 | hash->mask = mask; | |
241 | hash->shift = shift; | |
242 | get_random_bytes(&hash->rnd, sizeof(hash->rnd)); | |
243 | ||
244 | for (i = 0; i <= omask; i++) { | |
245 | struct sock *sk; | |
246 | struct hlist_node *node, *tmp; | |
247 | ||
248 | sk_for_each_safe(sk, node, tmp, &otable[i]) | |
249 | __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid)); | |
250 | } | |
251 | ||
252 | nl_pid_hash_free(otable, osize); | |
253 | hash->rehash_time = jiffies + 10 * 60 * HZ; | |
254 | return 1; | |
255 | } | |
256 | ||
257 | static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len) | |
258 | { | |
259 | int avg = hash->entries >> hash->shift; | |
260 | ||
261 | if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1)) | |
262 | return 1; | |
263 | ||
264 | if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) { | |
265 | nl_pid_hash_rehash(hash, 0); | |
266 | return 1; | |
267 | } | |
268 | ||
269 | return 0; | |
270 | } | |
271 | ||
272 | static struct proto_ops netlink_ops; | |
273 | ||
274 | static int netlink_insert(struct sock *sk, u32 pid) | |
275 | { | |
276 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; | |
277 | struct hlist_head *head; | |
278 | int err = -EADDRINUSE; | |
279 | struct sock *osk; | |
280 | struct hlist_node *node; | |
281 | int len; | |
282 | ||
283 | netlink_table_grab(); | |
284 | head = nl_pid_hashfn(hash, pid); | |
285 | len = 0; | |
286 | sk_for_each(osk, node, head) { | |
287 | if (nlk_sk(osk)->pid == pid) | |
288 | break; | |
289 | len++; | |
290 | } | |
291 | if (node) | |
292 | goto err; | |
293 | ||
294 | err = -EBUSY; | |
295 | if (nlk_sk(sk)->pid) | |
296 | goto err; | |
297 | ||
298 | err = -ENOMEM; | |
299 | if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX)) | |
300 | goto err; | |
301 | ||
302 | if (len && nl_pid_hash_dilute(hash, len)) | |
303 | head = nl_pid_hashfn(hash, pid); | |
304 | hash->entries++; | |
305 | nlk_sk(sk)->pid = pid; | |
306 | sk_add_node(sk, head); | |
307 | err = 0; | |
308 | ||
309 | err: | |
310 | netlink_table_ungrab(); | |
311 | return err; | |
312 | } | |
313 | ||
314 | static void netlink_remove(struct sock *sk) | |
315 | { | |
316 | netlink_table_grab(); | |
317 | nl_table[sk->sk_protocol].hash.entries--; | |
318 | sk_del_node_init(sk); | |
319 | if (nlk_sk(sk)->groups) | |
320 | __sk_del_bind_node(sk); | |
321 | netlink_table_ungrab(); | |
322 | } | |
323 | ||
324 | static struct proto netlink_proto = { | |
325 | .name = "NETLINK", | |
326 | .owner = THIS_MODULE, | |
327 | .obj_size = sizeof(struct netlink_sock), | |
328 | }; | |
329 | ||
330 | static int netlink_create(struct socket *sock, int protocol) | |
331 | { | |
332 | struct sock *sk; | |
333 | struct netlink_sock *nlk; | |
334 | ||
335 | sock->state = SS_UNCONNECTED; | |
336 | ||
337 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
338 | return -ESOCKTNOSUPPORT; | |
339 | ||
340 | if (protocol<0 || protocol >= MAX_LINKS) | |
341 | return -EPROTONOSUPPORT; | |
342 | ||
343 | sock->ops = &netlink_ops; | |
344 | ||
345 | sk = sk_alloc(PF_NETLINK, GFP_KERNEL, &netlink_proto, 1); | |
346 | if (!sk) | |
347 | return -ENOMEM; | |
348 | ||
349 | sock_init_data(sock, sk); | |
350 | ||
351 | nlk = nlk_sk(sk); | |
352 | ||
353 | spin_lock_init(&nlk->cb_lock); | |
354 | init_waitqueue_head(&nlk->wait); | |
355 | sk->sk_destruct = netlink_sock_destruct; | |
356 | ||
357 | sk->sk_protocol = protocol; | |
358 | return 0; | |
359 | } | |
360 | ||
361 | static int netlink_release(struct socket *sock) | |
362 | { | |
363 | struct sock *sk = sock->sk; | |
364 | struct netlink_sock *nlk; | |
365 | ||
366 | if (!sk) | |
367 | return 0; | |
368 | ||
369 | netlink_remove(sk); | |
370 | nlk = nlk_sk(sk); | |
371 | ||
372 | spin_lock(&nlk->cb_lock); | |
373 | if (nlk->cb) { | |
374 | nlk->cb->done(nlk->cb); | |
375 | netlink_destroy_callback(nlk->cb); | |
376 | nlk->cb = NULL; | |
377 | __sock_put(sk); | |
378 | } | |
379 | spin_unlock(&nlk->cb_lock); | |
380 | ||
381 | /* OK. Socket is unlinked, and, therefore, | |
382 | no new packets will arrive */ | |
383 | ||
384 | sock_orphan(sk); | |
385 | sock->sk = NULL; | |
386 | wake_up_interruptible_all(&nlk->wait); | |
387 | ||
388 | skb_queue_purge(&sk->sk_write_queue); | |
389 | ||
390 | if (nlk->pid && !nlk->groups) { | |
391 | struct netlink_notify n = { | |
392 | .protocol = sk->sk_protocol, | |
393 | .pid = nlk->pid, | |
394 | }; | |
395 | notifier_call_chain(&netlink_chain, NETLINK_URELEASE, &n); | |
396 | } | |
397 | ||
398 | sock_put(sk); | |
399 | return 0; | |
400 | } | |
401 | ||
402 | static int netlink_autobind(struct socket *sock) | |
403 | { | |
404 | struct sock *sk = sock->sk; | |
405 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; | |
406 | struct hlist_head *head; | |
407 | struct sock *osk; | |
408 | struct hlist_node *node; | |
409 | s32 pid = current->pid; | |
410 | int err; | |
411 | static s32 rover = -4097; | |
412 | ||
413 | retry: | |
414 | cond_resched(); | |
415 | netlink_table_grab(); | |
416 | head = nl_pid_hashfn(hash, pid); | |
417 | sk_for_each(osk, node, head) { | |
418 | if (nlk_sk(osk)->pid == pid) { | |
419 | /* Bind collision, search negative pid values. */ | |
420 | pid = rover--; | |
421 | if (rover > -4097) | |
422 | rover = -4097; | |
423 | netlink_table_ungrab(); | |
424 | goto retry; | |
425 | } | |
426 | } | |
427 | netlink_table_ungrab(); | |
428 | ||
429 | err = netlink_insert(sk, pid); | |
430 | if (err == -EADDRINUSE) | |
431 | goto retry; | |
432 | return 0; | |
433 | } | |
434 | ||
435 | static inline int netlink_capable(struct socket *sock, unsigned int flag) | |
436 | { | |
437 | return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) || | |
438 | capable(CAP_NET_ADMIN); | |
439 | } | |
440 | ||
441 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len) | |
442 | { | |
443 | struct sock *sk = sock->sk; | |
444 | struct netlink_sock *nlk = nlk_sk(sk); | |
445 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
446 | int err; | |
447 | ||
448 | if (nladdr->nl_family != AF_NETLINK) | |
449 | return -EINVAL; | |
450 | ||
451 | /* Only superuser is allowed to listen multicasts */ | |
452 | if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_RECV)) | |
453 | return -EPERM; | |
454 | ||
455 | if (nlk->pid) { | |
456 | if (nladdr->nl_pid != nlk->pid) | |
457 | return -EINVAL; | |
458 | } else { | |
459 | err = nladdr->nl_pid ? | |
460 | netlink_insert(sk, nladdr->nl_pid) : | |
461 | netlink_autobind(sock); | |
462 | if (err) | |
463 | return err; | |
464 | } | |
465 | ||
466 | if (!nladdr->nl_groups && !nlk->groups) | |
467 | return 0; | |
468 | ||
469 | netlink_table_grab(); | |
470 | if (nlk->groups && !nladdr->nl_groups) | |
471 | __sk_del_bind_node(sk); | |
472 | else if (!nlk->groups && nladdr->nl_groups) | |
473 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
474 | nlk->groups = nladdr->nl_groups; | |
475 | netlink_table_ungrab(); | |
476 | ||
477 | return 0; | |
478 | } | |
479 | ||
480 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
481 | int alen, int flags) | |
482 | { | |
483 | int err = 0; | |
484 | struct sock *sk = sock->sk; | |
485 | struct netlink_sock *nlk = nlk_sk(sk); | |
486 | struct sockaddr_nl *nladdr=(struct sockaddr_nl*)addr; | |
487 | ||
488 | if (addr->sa_family == AF_UNSPEC) { | |
489 | sk->sk_state = NETLINK_UNCONNECTED; | |
490 | nlk->dst_pid = 0; | |
491 | nlk->dst_groups = 0; | |
492 | return 0; | |
493 | } | |
494 | if (addr->sa_family != AF_NETLINK) | |
495 | return -EINVAL; | |
496 | ||
497 | /* Only superuser is allowed to send multicasts */ | |
498 | if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND)) | |
499 | return -EPERM; | |
500 | ||
501 | if (!nlk->pid) | |
502 | err = netlink_autobind(sock); | |
503 | ||
504 | if (err == 0) { | |
505 | sk->sk_state = NETLINK_CONNECTED; | |
506 | nlk->dst_pid = nladdr->nl_pid; | |
507 | nlk->dst_groups = nladdr->nl_groups; | |
508 | } | |
509 | ||
510 | return err; | |
511 | } | |
512 | ||
513 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, int *addr_len, int peer) | |
514 | { | |
515 | struct sock *sk = sock->sk; | |
516 | struct netlink_sock *nlk = nlk_sk(sk); | |
517 | struct sockaddr_nl *nladdr=(struct sockaddr_nl *)addr; | |
518 | ||
519 | nladdr->nl_family = AF_NETLINK; | |
520 | nladdr->nl_pad = 0; | |
521 | *addr_len = sizeof(*nladdr); | |
522 | ||
523 | if (peer) { | |
524 | nladdr->nl_pid = nlk->dst_pid; | |
525 | nladdr->nl_groups = nlk->dst_groups; | |
526 | } else { | |
527 | nladdr->nl_pid = nlk->pid; | |
528 | nladdr->nl_groups = nlk->groups; | |
529 | } | |
530 | return 0; | |
531 | } | |
532 | ||
533 | static void netlink_overrun(struct sock *sk) | |
534 | { | |
535 | if (!test_and_set_bit(0, &nlk_sk(sk)->state)) { | |
536 | sk->sk_err = ENOBUFS; | |
537 | sk->sk_error_report(sk); | |
538 | } | |
539 | } | |
540 | ||
541 | static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid) | |
542 | { | |
543 | int protocol = ssk->sk_protocol; | |
544 | struct sock *sock; | |
545 | struct netlink_sock *nlk; | |
546 | ||
547 | sock = netlink_lookup(protocol, pid); | |
548 | if (!sock) | |
549 | return ERR_PTR(-ECONNREFUSED); | |
550 | ||
551 | /* Don't bother queuing skb if kernel socket has no input function */ | |
552 | nlk = nlk_sk(sock); | |
553 | if ((nlk->pid == 0 && !nlk->data_ready) || | |
554 | (sock->sk_state == NETLINK_CONNECTED && | |
555 | nlk->dst_pid != nlk_sk(ssk)->pid)) { | |
556 | sock_put(sock); | |
557 | return ERR_PTR(-ECONNREFUSED); | |
558 | } | |
559 | return sock; | |
560 | } | |
561 | ||
562 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
563 | { | |
564 | struct inode *inode = filp->f_dentry->d_inode; | |
565 | struct sock *sock; | |
566 | ||
567 | if (!S_ISSOCK(inode->i_mode)) | |
568 | return ERR_PTR(-ENOTSOCK); | |
569 | ||
570 | sock = SOCKET_I(inode)->sk; | |
571 | if (sock->sk_family != AF_NETLINK) | |
572 | return ERR_PTR(-EINVAL); | |
573 | ||
574 | sock_hold(sock); | |
575 | return sock; | |
576 | } | |
577 | ||
578 | /* | |
579 | * Attach a skb to a netlink socket. | |
580 | * The caller must hold a reference to the destination socket. On error, the | |
581 | * reference is dropped. The skb is not send to the destination, just all | |
582 | * all error checks are performed and memory in the queue is reserved. | |
583 | * Return values: | |
584 | * < 0: error. skb freed, reference to sock dropped. | |
585 | * 0: continue | |
586 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
587 | */ | |
588 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock, long timeo) | |
589 | { | |
590 | struct netlink_sock *nlk; | |
591 | ||
592 | nlk = nlk_sk(sk); | |
593 | ||
594 | if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
595 | test_bit(0, &nlk->state)) { | |
596 | DECLARE_WAITQUEUE(wait, current); | |
597 | if (!timeo) { | |
598 | if (!nlk->pid) | |
599 | netlink_overrun(sk); | |
600 | sock_put(sk); | |
601 | kfree_skb(skb); | |
602 | return -EAGAIN; | |
603 | } | |
604 | ||
605 | __set_current_state(TASK_INTERRUPTIBLE); | |
606 | add_wait_queue(&nlk->wait, &wait); | |
607 | ||
608 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
609 | test_bit(0, &nlk->state)) && | |
610 | !sock_flag(sk, SOCK_DEAD)) | |
611 | timeo = schedule_timeout(timeo); | |
612 | ||
613 | __set_current_state(TASK_RUNNING); | |
614 | remove_wait_queue(&nlk->wait, &wait); | |
615 | sock_put(sk); | |
616 | ||
617 | if (signal_pending(current)) { | |
618 | kfree_skb(skb); | |
619 | return sock_intr_errno(timeo); | |
620 | } | |
621 | return 1; | |
622 | } | |
623 | skb_set_owner_r(skb, sk); | |
624 | return 0; | |
625 | } | |
626 | ||
627 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb, int protocol) | |
628 | { | |
629 | struct netlink_sock *nlk; | |
630 | int len = skb->len; | |
631 | ||
632 | nlk = nlk_sk(sk); | |
633 | ||
634 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
635 | sk->sk_data_ready(sk, len); | |
636 | sock_put(sk); | |
637 | return len; | |
638 | } | |
639 | ||
640 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
641 | { | |
642 | kfree_skb(skb); | |
643 | sock_put(sk); | |
644 | } | |
645 | ||
646 | static inline struct sk_buff *netlink_trim(struct sk_buff *skb, int allocation) | |
647 | { | |
648 | int delta; | |
649 | ||
650 | skb_orphan(skb); | |
651 | ||
652 | delta = skb->end - skb->tail; | |
653 | if (delta * 2 < skb->truesize) | |
654 | return skb; | |
655 | ||
656 | if (skb_shared(skb)) { | |
657 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
658 | if (!nskb) | |
659 | return skb; | |
660 | kfree_skb(skb); | |
661 | skb = nskb; | |
662 | } | |
663 | ||
664 | if (!pskb_expand_head(skb, 0, -delta, allocation)) | |
665 | skb->truesize -= delta; | |
666 | ||
667 | return skb; | |
668 | } | |
669 | ||
670 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, u32 pid, int nonblock) | |
671 | { | |
672 | struct sock *sk; | |
673 | int err; | |
674 | long timeo; | |
675 | ||
676 | skb = netlink_trim(skb, gfp_any()); | |
677 | ||
678 | timeo = sock_sndtimeo(ssk, nonblock); | |
679 | retry: | |
680 | sk = netlink_getsockbypid(ssk, pid); | |
681 | if (IS_ERR(sk)) { | |
682 | kfree_skb(skb); | |
683 | return PTR_ERR(sk); | |
684 | } | |
685 | err = netlink_attachskb(sk, skb, nonblock, timeo); | |
686 | if (err == 1) | |
687 | goto retry; | |
688 | if (err) | |
689 | return err; | |
690 | ||
691 | return netlink_sendskb(sk, skb, ssk->sk_protocol); | |
692 | } | |
693 | ||
694 | static __inline__ int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) | |
695 | { | |
696 | struct netlink_sock *nlk = nlk_sk(sk); | |
697 | ||
698 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
699 | !test_bit(0, &nlk->state)) { | |
700 | skb_set_owner_r(skb, sk); | |
701 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
702 | sk->sk_data_ready(sk, skb->len); | |
703 | return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf; | |
704 | } | |
705 | return -1; | |
706 | } | |
707 | ||
708 | struct netlink_broadcast_data { | |
709 | struct sock *exclude_sk; | |
710 | u32 pid; | |
711 | u32 group; | |
712 | int failure; | |
713 | int congested; | |
714 | int delivered; | |
715 | int allocation; | |
716 | struct sk_buff *skb, *skb2; | |
717 | }; | |
718 | ||
719 | static inline int do_one_broadcast(struct sock *sk, | |
720 | struct netlink_broadcast_data *p) | |
721 | { | |
722 | struct netlink_sock *nlk = nlk_sk(sk); | |
723 | int val; | |
724 | ||
725 | if (p->exclude_sk == sk) | |
726 | goto out; | |
727 | ||
728 | if (nlk->pid == p->pid || !(nlk->groups & p->group)) | |
729 | goto out; | |
730 | ||
731 | if (p->failure) { | |
732 | netlink_overrun(sk); | |
733 | goto out; | |
734 | } | |
735 | ||
736 | sock_hold(sk); | |
737 | if (p->skb2 == NULL) { | |
738 | if (atomic_read(&p->skb->users) != 1) { | |
739 | p->skb2 = skb_clone(p->skb, p->allocation); | |
740 | } else { | |
741 | p->skb2 = p->skb; | |
742 | atomic_inc(&p->skb->users); | |
743 | } | |
744 | } | |
745 | if (p->skb2 == NULL) { | |
746 | netlink_overrun(sk); | |
747 | /* Clone failed. Notify ALL listeners. */ | |
748 | p->failure = 1; | |
749 | } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) { | |
750 | netlink_overrun(sk); | |
751 | } else { | |
752 | p->congested |= val; | |
753 | p->delivered = 1; | |
754 | p->skb2 = NULL; | |
755 | } | |
756 | sock_put(sk); | |
757 | ||
758 | out: | |
759 | return 0; | |
760 | } | |
761 | ||
762 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid, | |
763 | u32 group, int allocation) | |
764 | { | |
765 | struct netlink_broadcast_data info; | |
766 | struct hlist_node *node; | |
767 | struct sock *sk; | |
768 | ||
769 | skb = netlink_trim(skb, allocation); | |
770 | ||
771 | info.exclude_sk = ssk; | |
772 | info.pid = pid; | |
773 | info.group = group; | |
774 | info.failure = 0; | |
775 | info.congested = 0; | |
776 | info.delivered = 0; | |
777 | info.allocation = allocation; | |
778 | info.skb = skb; | |
779 | info.skb2 = NULL; | |
780 | ||
781 | /* While we sleep in clone, do not allow to change socket list */ | |
782 | ||
783 | netlink_lock_table(); | |
784 | ||
785 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
786 | do_one_broadcast(sk, &info); | |
787 | ||
788 | netlink_unlock_table(); | |
789 | ||
790 | if (info.skb2) | |
791 | kfree_skb(info.skb2); | |
792 | kfree_skb(skb); | |
793 | ||
794 | if (info.delivered) { | |
795 | if (info.congested && (allocation & __GFP_WAIT)) | |
796 | yield(); | |
797 | return 0; | |
798 | } | |
799 | if (info.failure) | |
800 | return -ENOBUFS; | |
801 | return -ESRCH; | |
802 | } | |
803 | ||
804 | struct netlink_set_err_data { | |
805 | struct sock *exclude_sk; | |
806 | u32 pid; | |
807 | u32 group; | |
808 | int code; | |
809 | }; | |
810 | ||
811 | static inline int do_one_set_err(struct sock *sk, | |
812 | struct netlink_set_err_data *p) | |
813 | { | |
814 | struct netlink_sock *nlk = nlk_sk(sk); | |
815 | ||
816 | if (sk == p->exclude_sk) | |
817 | goto out; | |
818 | ||
819 | if (nlk->pid == p->pid || !(nlk->groups & p->group)) | |
820 | goto out; | |
821 | ||
822 | sk->sk_err = p->code; | |
823 | sk->sk_error_report(sk); | |
824 | out: | |
825 | return 0; | |
826 | } | |
827 | ||
828 | void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) | |
829 | { | |
830 | struct netlink_set_err_data info; | |
831 | struct hlist_node *node; | |
832 | struct sock *sk; | |
833 | ||
834 | info.exclude_sk = ssk; | |
835 | info.pid = pid; | |
836 | info.group = group; | |
837 | info.code = code; | |
838 | ||
839 | read_lock(&nl_table_lock); | |
840 | ||
841 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
842 | do_one_set_err(sk, &info); | |
843 | ||
844 | read_unlock(&nl_table_lock); | |
845 | } | |
846 | ||
847 | static inline void netlink_rcv_wake(struct sock *sk) | |
848 | { | |
849 | struct netlink_sock *nlk = nlk_sk(sk); | |
850 | ||
851 | if (!skb_queue_len(&sk->sk_receive_queue)) | |
852 | clear_bit(0, &nlk->state); | |
853 | if (!test_bit(0, &nlk->state)) | |
854 | wake_up_interruptible(&nlk->wait); | |
855 | } | |
856 | ||
857 | static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, | |
858 | struct msghdr *msg, size_t len) | |
859 | { | |
860 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
861 | struct sock *sk = sock->sk; | |
862 | struct netlink_sock *nlk = nlk_sk(sk); | |
863 | struct sockaddr_nl *addr=msg->msg_name; | |
864 | u32 dst_pid; | |
865 | u32 dst_groups; | |
866 | struct sk_buff *skb; | |
867 | int err; | |
868 | struct scm_cookie scm; | |
869 | ||
870 | if (msg->msg_flags&MSG_OOB) | |
871 | return -EOPNOTSUPP; | |
872 | ||
873 | if (NULL == siocb->scm) | |
874 | siocb->scm = &scm; | |
875 | err = scm_send(sock, msg, siocb->scm); | |
876 | if (err < 0) | |
877 | return err; | |
878 | ||
879 | if (msg->msg_namelen) { | |
880 | if (addr->nl_family != AF_NETLINK) | |
881 | return -EINVAL; | |
882 | dst_pid = addr->nl_pid; | |
883 | dst_groups = addr->nl_groups; | |
884 | if (dst_groups && !netlink_capable(sock, NL_NONROOT_SEND)) | |
885 | return -EPERM; | |
886 | } else { | |
887 | dst_pid = nlk->dst_pid; | |
888 | dst_groups = nlk->dst_groups; | |
889 | } | |
890 | ||
891 | if (!nlk->pid) { | |
892 | err = netlink_autobind(sock); | |
893 | if (err) | |
894 | goto out; | |
895 | } | |
896 | ||
897 | err = -EMSGSIZE; | |
898 | if (len > sk->sk_sndbuf - 32) | |
899 | goto out; | |
900 | err = -ENOBUFS; | |
901 | skb = alloc_skb(len, GFP_KERNEL); | |
902 | if (skb==NULL) | |
903 | goto out; | |
904 | ||
905 | NETLINK_CB(skb).pid = nlk->pid; | |
906 | NETLINK_CB(skb).groups = nlk->groups; | |
907 | NETLINK_CB(skb).dst_pid = dst_pid; | |
908 | NETLINK_CB(skb).dst_groups = dst_groups; | |
909 | memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); | |
910 | ||
911 | /* What can I do? Netlink is asynchronous, so that | |
912 | we will have to save current capabilities to | |
913 | check them, when this message will be delivered | |
914 | to corresponding kernel module. --ANK (980802) | |
915 | */ | |
916 | ||
917 | err = -EFAULT; | |
918 | if (memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len)) { | |
919 | kfree_skb(skb); | |
920 | goto out; | |
921 | } | |
922 | ||
923 | err = security_netlink_send(sk, skb); | |
924 | if (err) { | |
925 | kfree_skb(skb); | |
926 | goto out; | |
927 | } | |
928 | ||
929 | if (dst_groups) { | |
930 | atomic_inc(&skb->users); | |
931 | netlink_broadcast(sk, skb, dst_pid, dst_groups, GFP_KERNEL); | |
932 | } | |
933 | err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT); | |
934 | ||
935 | out: | |
936 | return err; | |
937 | } | |
938 | ||
939 | static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, | |
940 | struct msghdr *msg, size_t len, | |
941 | int flags) | |
942 | { | |
943 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
944 | struct scm_cookie scm; | |
945 | struct sock *sk = sock->sk; | |
946 | struct netlink_sock *nlk = nlk_sk(sk); | |
947 | int noblock = flags&MSG_DONTWAIT; | |
948 | size_t copied; | |
949 | struct sk_buff *skb; | |
950 | int err; | |
951 | ||
952 | if (flags&MSG_OOB) | |
953 | return -EOPNOTSUPP; | |
954 | ||
955 | copied = 0; | |
956 | ||
957 | skb = skb_recv_datagram(sk,flags,noblock,&err); | |
958 | if (skb==NULL) | |
959 | goto out; | |
960 | ||
961 | msg->msg_namelen = 0; | |
962 | ||
963 | copied = skb->len; | |
964 | if (len < copied) { | |
965 | msg->msg_flags |= MSG_TRUNC; | |
966 | copied = len; | |
967 | } | |
968 | ||
969 | skb->h.raw = skb->data; | |
970 | err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); | |
971 | ||
972 | if (msg->msg_name) { | |
973 | struct sockaddr_nl *addr = (struct sockaddr_nl*)msg->msg_name; | |
974 | addr->nl_family = AF_NETLINK; | |
975 | addr->nl_pad = 0; | |
976 | addr->nl_pid = NETLINK_CB(skb).pid; | |
977 | addr->nl_groups = NETLINK_CB(skb).dst_groups; | |
978 | msg->msg_namelen = sizeof(*addr); | |
979 | } | |
980 | ||
981 | if (NULL == siocb->scm) { | |
982 | memset(&scm, 0, sizeof(scm)); | |
983 | siocb->scm = &scm; | |
984 | } | |
985 | siocb->scm->creds = *NETLINK_CREDS(skb); | |
986 | skb_free_datagram(sk, skb); | |
987 | ||
988 | if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) | |
989 | netlink_dump(sk); | |
990 | ||
991 | scm_recv(sock, msg, siocb->scm, flags); | |
992 | ||
993 | out: | |
994 | netlink_rcv_wake(sk); | |
995 | return err ? : copied; | |
996 | } | |
997 | ||
998 | static void netlink_data_ready(struct sock *sk, int len) | |
999 | { | |
1000 | struct netlink_sock *nlk = nlk_sk(sk); | |
1001 | ||
1002 | if (nlk->data_ready) | |
1003 | nlk->data_ready(sk, len); | |
1004 | netlink_rcv_wake(sk); | |
1005 | } | |
1006 | ||
1007 | /* | |
1008 | * We export these functions to other modules. They provide a | |
1009 | * complete set of kernel non-blocking support for message | |
1010 | * queueing. | |
1011 | */ | |
1012 | ||
1013 | struct sock * | |
1014 | netlink_kernel_create(int unit, void (*input)(struct sock *sk, int len)) | |
1015 | { | |
1016 | struct socket *sock; | |
1017 | struct sock *sk; | |
1018 | ||
1019 | if (!nl_table) | |
1020 | return NULL; | |
1021 | ||
1022 | if (unit<0 || unit>=MAX_LINKS) | |
1023 | return NULL; | |
1024 | ||
1025 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
1026 | return NULL; | |
1027 | ||
1028 | if (netlink_create(sock, unit) < 0) { | |
1029 | sock_release(sock); | |
1030 | return NULL; | |
1031 | } | |
1032 | sk = sock->sk; | |
1033 | sk->sk_data_ready = netlink_data_ready; | |
1034 | if (input) | |
1035 | nlk_sk(sk)->data_ready = input; | |
1036 | ||
1037 | if (netlink_insert(sk, 0)) { | |
1038 | sock_release(sock); | |
1039 | return NULL; | |
1040 | } | |
1041 | return sk; | |
1042 | } | |
1043 | ||
1044 | void netlink_set_nonroot(int protocol, unsigned int flags) | |
1045 | { | |
1046 | if ((unsigned int)protocol < MAX_LINKS) | |
1047 | nl_table[protocol].nl_nonroot = flags; | |
1048 | } | |
1049 | ||
1050 | static void netlink_destroy_callback(struct netlink_callback *cb) | |
1051 | { | |
1052 | if (cb->skb) | |
1053 | kfree_skb(cb->skb); | |
1054 | kfree(cb); | |
1055 | } | |
1056 | ||
1057 | /* | |
1058 | * It looks a bit ugly. | |
1059 | * It would be better to create kernel thread. | |
1060 | */ | |
1061 | ||
1062 | static int netlink_dump(struct sock *sk) | |
1063 | { | |
1064 | struct netlink_sock *nlk = nlk_sk(sk); | |
1065 | struct netlink_callback *cb; | |
1066 | struct sk_buff *skb; | |
1067 | struct nlmsghdr *nlh; | |
1068 | int len; | |
1069 | ||
1070 | skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL); | |
1071 | if (!skb) | |
1072 | return -ENOBUFS; | |
1073 | ||
1074 | spin_lock(&nlk->cb_lock); | |
1075 | ||
1076 | cb = nlk->cb; | |
1077 | if (cb == NULL) { | |
1078 | spin_unlock(&nlk->cb_lock); | |
1079 | kfree_skb(skb); | |
1080 | return -EINVAL; | |
1081 | } | |
1082 | ||
1083 | len = cb->dump(skb, cb); | |
1084 | ||
1085 | if (len > 0) { | |
1086 | spin_unlock(&nlk->cb_lock); | |
1087 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
1088 | sk->sk_data_ready(sk, len); | |
1089 | return 0; | |
1090 | } | |
1091 | ||
1092 | nlh = __nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, NLMSG_DONE, sizeof(int)); | |
1093 | nlh->nlmsg_flags |= NLM_F_MULTI; | |
1094 | memcpy(NLMSG_DATA(nlh), &len, sizeof(len)); | |
1095 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
1096 | sk->sk_data_ready(sk, skb->len); | |
1097 | ||
1098 | cb->done(cb); | |
1099 | nlk->cb = NULL; | |
1100 | spin_unlock(&nlk->cb_lock); | |
1101 | ||
1102 | netlink_destroy_callback(cb); | |
1103 | __sock_put(sk); | |
1104 | return 0; | |
1105 | } | |
1106 | ||
1107 | int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, | |
1108 | struct nlmsghdr *nlh, | |
1109 | int (*dump)(struct sk_buff *skb, struct netlink_callback*), | |
1110 | int (*done)(struct netlink_callback*)) | |
1111 | { | |
1112 | struct netlink_callback *cb; | |
1113 | struct sock *sk; | |
1114 | struct netlink_sock *nlk; | |
1115 | ||
1116 | cb = kmalloc(sizeof(*cb), GFP_KERNEL); | |
1117 | if (cb == NULL) | |
1118 | return -ENOBUFS; | |
1119 | ||
1120 | memset(cb, 0, sizeof(*cb)); | |
1121 | cb->dump = dump; | |
1122 | cb->done = done; | |
1123 | cb->nlh = nlh; | |
1124 | atomic_inc(&skb->users); | |
1125 | cb->skb = skb; | |
1126 | ||
1127 | sk = netlink_lookup(ssk->sk_protocol, NETLINK_CB(skb).pid); | |
1128 | if (sk == NULL) { | |
1129 | netlink_destroy_callback(cb); | |
1130 | return -ECONNREFUSED; | |
1131 | } | |
1132 | nlk = nlk_sk(sk); | |
1133 | /* A dump is in progress... */ | |
1134 | spin_lock(&nlk->cb_lock); | |
1135 | if (nlk->cb) { | |
1136 | spin_unlock(&nlk->cb_lock); | |
1137 | netlink_destroy_callback(cb); | |
1138 | sock_put(sk); | |
1139 | return -EBUSY; | |
1140 | } | |
1141 | nlk->cb = cb; | |
1142 | sock_hold(sk); | |
1143 | spin_unlock(&nlk->cb_lock); | |
1144 | ||
1145 | netlink_dump(sk); | |
1146 | sock_put(sk); | |
1147 | return 0; | |
1148 | } | |
1149 | ||
1150 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) | |
1151 | { | |
1152 | struct sk_buff *skb; | |
1153 | struct nlmsghdr *rep; | |
1154 | struct nlmsgerr *errmsg; | |
1155 | int size; | |
1156 | ||
1157 | if (err == 0) | |
1158 | size = NLMSG_SPACE(sizeof(struct nlmsgerr)); | |
1159 | else | |
1160 | size = NLMSG_SPACE(4 + NLMSG_ALIGN(nlh->nlmsg_len)); | |
1161 | ||
1162 | skb = alloc_skb(size, GFP_KERNEL); | |
1163 | if (!skb) { | |
1164 | struct sock *sk; | |
1165 | ||
1166 | sk = netlink_lookup(in_skb->sk->sk_protocol, | |
1167 | NETLINK_CB(in_skb).pid); | |
1168 | if (sk) { | |
1169 | sk->sk_err = ENOBUFS; | |
1170 | sk->sk_error_report(sk); | |
1171 | sock_put(sk); | |
1172 | } | |
1173 | return; | |
1174 | } | |
1175 | ||
1176 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, | |
1177 | NLMSG_ERROR, sizeof(struct nlmsgerr)); | |
1178 | errmsg = NLMSG_DATA(rep); | |
1179 | errmsg->error = err; | |
1180 | memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(struct nlmsghdr)); | |
1181 | netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT); | |
1182 | } | |
1183 | ||
1184 | ||
1185 | #ifdef CONFIG_PROC_FS | |
1186 | struct nl_seq_iter { | |
1187 | int link; | |
1188 | int hash_idx; | |
1189 | }; | |
1190 | ||
1191 | static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) | |
1192 | { | |
1193 | struct nl_seq_iter *iter = seq->private; | |
1194 | int i, j; | |
1195 | struct sock *s; | |
1196 | struct hlist_node *node; | |
1197 | loff_t off = 0; | |
1198 | ||
1199 | for (i=0; i<MAX_LINKS; i++) { | |
1200 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1201 | ||
1202 | for (j = 0; j <= hash->mask; j++) { | |
1203 | sk_for_each(s, node, &hash->table[j]) { | |
1204 | if (off == pos) { | |
1205 | iter->link = i; | |
1206 | iter->hash_idx = j; | |
1207 | return s; | |
1208 | } | |
1209 | ++off; | |
1210 | } | |
1211 | } | |
1212 | } | |
1213 | return NULL; | |
1214 | } | |
1215 | ||
1216 | static void *netlink_seq_start(struct seq_file *seq, loff_t *pos) | |
1217 | { | |
1218 | read_lock(&nl_table_lock); | |
1219 | return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
1220 | } | |
1221 | ||
1222 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
1223 | { | |
1224 | struct sock *s; | |
1225 | struct nl_seq_iter *iter; | |
1226 | int i, j; | |
1227 | ||
1228 | ++*pos; | |
1229 | ||
1230 | if (v == SEQ_START_TOKEN) | |
1231 | return netlink_seq_socket_idx(seq, 0); | |
1232 | ||
1233 | s = sk_next(v); | |
1234 | if (s) | |
1235 | return s; | |
1236 | ||
1237 | iter = seq->private; | |
1238 | i = iter->link; | |
1239 | j = iter->hash_idx + 1; | |
1240 | ||
1241 | do { | |
1242 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1243 | ||
1244 | for (; j <= hash->mask; j++) { | |
1245 | s = sk_head(&hash->table[j]); | |
1246 | if (s) { | |
1247 | iter->link = i; | |
1248 | iter->hash_idx = j; | |
1249 | return s; | |
1250 | } | |
1251 | } | |
1252 | ||
1253 | j = 0; | |
1254 | } while (++i < MAX_LINKS); | |
1255 | ||
1256 | return NULL; | |
1257 | } | |
1258 | ||
1259 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
1260 | { | |
1261 | read_unlock(&nl_table_lock); | |
1262 | } | |
1263 | ||
1264 | ||
1265 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
1266 | { | |
1267 | if (v == SEQ_START_TOKEN) | |
1268 | seq_puts(seq, | |
1269 | "sk Eth Pid Groups " | |
1270 | "Rmem Wmem Dump Locks\n"); | |
1271 | else { | |
1272 | struct sock *s = v; | |
1273 | struct netlink_sock *nlk = nlk_sk(s); | |
1274 | ||
1275 | seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %d\n", | |
1276 | s, | |
1277 | s->sk_protocol, | |
1278 | nlk->pid, | |
1279 | nlk->groups, | |
1280 | atomic_read(&s->sk_rmem_alloc), | |
1281 | atomic_read(&s->sk_wmem_alloc), | |
1282 | nlk->cb, | |
1283 | atomic_read(&s->sk_refcnt) | |
1284 | ); | |
1285 | ||
1286 | } | |
1287 | return 0; | |
1288 | } | |
1289 | ||
1290 | static struct seq_operations netlink_seq_ops = { | |
1291 | .start = netlink_seq_start, | |
1292 | .next = netlink_seq_next, | |
1293 | .stop = netlink_seq_stop, | |
1294 | .show = netlink_seq_show, | |
1295 | }; | |
1296 | ||
1297 | ||
1298 | static int netlink_seq_open(struct inode *inode, struct file *file) | |
1299 | { | |
1300 | struct seq_file *seq; | |
1301 | struct nl_seq_iter *iter; | |
1302 | int err; | |
1303 | ||
1304 | iter = kmalloc(sizeof(*iter), GFP_KERNEL); | |
1305 | if (!iter) | |
1306 | return -ENOMEM; | |
1307 | ||
1308 | err = seq_open(file, &netlink_seq_ops); | |
1309 | if (err) { | |
1310 | kfree(iter); | |
1311 | return err; | |
1312 | } | |
1313 | ||
1314 | memset(iter, 0, sizeof(*iter)); | |
1315 | seq = file->private_data; | |
1316 | seq->private = iter; | |
1317 | return 0; | |
1318 | } | |
1319 | ||
1320 | static struct file_operations netlink_seq_fops = { | |
1321 | .owner = THIS_MODULE, | |
1322 | .open = netlink_seq_open, | |
1323 | .read = seq_read, | |
1324 | .llseek = seq_lseek, | |
1325 | .release = seq_release_private, | |
1326 | }; | |
1327 | ||
1328 | #endif | |
1329 | ||
1330 | int netlink_register_notifier(struct notifier_block *nb) | |
1331 | { | |
1332 | return notifier_chain_register(&netlink_chain, nb); | |
1333 | } | |
1334 | ||
1335 | int netlink_unregister_notifier(struct notifier_block *nb) | |
1336 | { | |
1337 | return notifier_chain_unregister(&netlink_chain, nb); | |
1338 | } | |
1339 | ||
1340 | static struct proto_ops netlink_ops = { | |
1341 | .family = PF_NETLINK, | |
1342 | .owner = THIS_MODULE, | |
1343 | .release = netlink_release, | |
1344 | .bind = netlink_bind, | |
1345 | .connect = netlink_connect, | |
1346 | .socketpair = sock_no_socketpair, | |
1347 | .accept = sock_no_accept, | |
1348 | .getname = netlink_getname, | |
1349 | .poll = datagram_poll, | |
1350 | .ioctl = sock_no_ioctl, | |
1351 | .listen = sock_no_listen, | |
1352 | .shutdown = sock_no_shutdown, | |
1353 | .setsockopt = sock_no_setsockopt, | |
1354 | .getsockopt = sock_no_getsockopt, | |
1355 | .sendmsg = netlink_sendmsg, | |
1356 | .recvmsg = netlink_recvmsg, | |
1357 | .mmap = sock_no_mmap, | |
1358 | .sendpage = sock_no_sendpage, | |
1359 | }; | |
1360 | ||
1361 | static struct net_proto_family netlink_family_ops = { | |
1362 | .family = PF_NETLINK, | |
1363 | .create = netlink_create, | |
1364 | .owner = THIS_MODULE, /* for consistency 8) */ | |
1365 | }; | |
1366 | ||
1367 | extern void netlink_skb_parms_too_large(void); | |
1368 | ||
1369 | static int __init netlink_proto_init(void) | |
1370 | { | |
1371 | struct sk_buff *dummy_skb; | |
1372 | int i; | |
1373 | unsigned long max; | |
1374 | unsigned int order; | |
1375 | int err = proto_register(&netlink_proto, 0); | |
1376 | ||
1377 | if (err != 0) | |
1378 | goto out; | |
1379 | ||
1380 | if (sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb)) | |
1381 | netlink_skb_parms_too_large(); | |
1382 | ||
1383 | nl_table = kmalloc(sizeof(*nl_table) * MAX_LINKS, GFP_KERNEL); | |
1384 | if (!nl_table) { | |
1385 | enomem: | |
1386 | printk(KERN_CRIT "netlink_init: Cannot allocate nl_table\n"); | |
1387 | return -ENOMEM; | |
1388 | } | |
1389 | ||
1390 | memset(nl_table, 0, sizeof(*nl_table) * MAX_LINKS); | |
1391 | ||
1392 | if (num_physpages >= (128 * 1024)) | |
1393 | max = num_physpages >> (21 - PAGE_SHIFT); | |
1394 | else | |
1395 | max = num_physpages >> (23 - PAGE_SHIFT); | |
1396 | ||
1397 | order = get_bitmask_order(max) - 1 + PAGE_SHIFT; | |
1398 | max = (1UL << order) / sizeof(struct hlist_head); | |
1399 | order = get_bitmask_order(max > UINT_MAX ? UINT_MAX : max) - 1; | |
1400 | ||
1401 | for (i = 0; i < MAX_LINKS; i++) { | |
1402 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1403 | ||
1404 | hash->table = nl_pid_hash_alloc(1 * sizeof(*hash->table)); | |
1405 | if (!hash->table) { | |
1406 | while (i-- > 0) | |
1407 | nl_pid_hash_free(nl_table[i].hash.table, | |
1408 | 1 * sizeof(*hash->table)); | |
1409 | kfree(nl_table); | |
1410 | goto enomem; | |
1411 | } | |
1412 | memset(hash->table, 0, 1 * sizeof(*hash->table)); | |
1413 | hash->max_shift = order; | |
1414 | hash->shift = 0; | |
1415 | hash->mask = 0; | |
1416 | hash->rehash_time = jiffies; | |
1417 | } | |
1418 | ||
1419 | sock_register(&netlink_family_ops); | |
1420 | #ifdef CONFIG_PROC_FS | |
1421 | proc_net_fops_create("netlink", 0, &netlink_seq_fops); | |
1422 | #endif | |
1423 | /* The netlink device handler may be needed early. */ | |
1424 | rtnetlink_init(); | |
1425 | out: | |
1426 | return err; | |
1427 | } | |
1428 | ||
1429 | static void __exit netlink_proto_exit(void) | |
1430 | { | |
1431 | sock_unregister(PF_NETLINK); | |
1432 | proc_net_remove("netlink"); | |
1433 | kfree(nl_table); | |
1434 | nl_table = NULL; | |
1435 | proto_unregister(&netlink_proto); | |
1436 | } | |
1437 | ||
1438 | core_initcall(netlink_proto_init); | |
1439 | module_exit(netlink_proto_exit); | |
1440 | ||
1441 | MODULE_LICENSE("GPL"); | |
1442 | ||
1443 | MODULE_ALIAS_NETPROTO(PF_NETLINK); | |
1444 | ||
1445 | EXPORT_SYMBOL(netlink_ack); | |
1446 | EXPORT_SYMBOL(netlink_broadcast); | |
1447 | EXPORT_SYMBOL(netlink_dump_start); | |
1448 | EXPORT_SYMBOL(netlink_kernel_create); | |
1449 | EXPORT_SYMBOL(netlink_register_notifier); | |
1450 | EXPORT_SYMBOL(netlink_set_err); | |
1451 | EXPORT_SYMBOL(netlink_set_nonroot); | |
1452 | EXPORT_SYMBOL(netlink_unicast); | |
1453 | EXPORT_SYMBOL(netlink_unregister_notifier); | |
1454 |