Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * NETLINK Kernel-user communication protocol. | |
3 | * | |
113aa838 | 4 | * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk> |
1da177e4 LT |
5 | * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
746fac4d | 11 | * |
1da177e4 LT |
12 | * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith |
13 | * added netlink_proto_exit | |
14 | * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br> | |
15 | * use nlk_sk, as sk->protinfo is on a diet 8) | |
4fdb3bb7 HW |
16 | * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org> |
17 | * - inc module use count of module that owns | |
18 | * the kernel socket in case userspace opens | |
19 | * socket of same protocol | |
20 | * - remove all module support, since netlink is | |
21 | * mandatory if CONFIG_NET=y these days | |
1da177e4 LT |
22 | */ |
23 | ||
1da177e4 LT |
24 | #include <linux/module.h> |
25 | ||
4fc268d2 | 26 | #include <linux/capability.h> |
1da177e4 LT |
27 | #include <linux/kernel.h> |
28 | #include <linux/init.h> | |
1da177e4 LT |
29 | #include <linux/signal.h> |
30 | #include <linux/sched.h> | |
31 | #include <linux/errno.h> | |
32 | #include <linux/string.h> | |
33 | #include <linux/stat.h> | |
34 | #include <linux/socket.h> | |
35 | #include <linux/un.h> | |
36 | #include <linux/fcntl.h> | |
37 | #include <linux/termios.h> | |
38 | #include <linux/sockios.h> | |
39 | #include <linux/net.h> | |
40 | #include <linux/fs.h> | |
41 | #include <linux/slab.h> | |
42 | #include <asm/uaccess.h> | |
43 | #include <linux/skbuff.h> | |
44 | #include <linux/netdevice.h> | |
45 | #include <linux/rtnetlink.h> | |
46 | #include <linux/proc_fs.h> | |
47 | #include <linux/seq_file.h> | |
1da177e4 LT |
48 | #include <linux/notifier.h> |
49 | #include <linux/security.h> | |
50 | #include <linux/jhash.h> | |
51 | #include <linux/jiffies.h> | |
52 | #include <linux/random.h> | |
53 | #include <linux/bitops.h> | |
54 | #include <linux/mm.h> | |
55 | #include <linux/types.h> | |
54e0f520 | 56 | #include <linux/audit.h> |
af65bdfc | 57 | #include <linux/mutex.h> |
ccdfcc39 | 58 | #include <linux/vmalloc.h> |
54e0f520 | 59 | |
457c4cbc | 60 | #include <net/net_namespace.h> |
1da177e4 LT |
61 | #include <net/sock.h> |
62 | #include <net/scm.h> | |
82ace47a | 63 | #include <net/netlink.h> |
1da177e4 | 64 | |
0f29c768 | 65 | #include "af_netlink.h" |
1da177e4 | 66 | |
5c398dc8 ED |
67 | struct listeners { |
68 | struct rcu_head rcu; | |
69 | unsigned long masks[0]; | |
6c04bb18 JB |
70 | }; |
71 | ||
cd967e05 PM |
72 | /* state bits */ |
73 | #define NETLINK_CONGESTED 0x0 | |
74 | ||
75 | /* flags */ | |
77247bbb | 76 | #define NETLINK_KERNEL_SOCKET 0x1 |
9a4595bc | 77 | #define NETLINK_RECV_PKTINFO 0x2 |
be0c22a4 | 78 | #define NETLINK_BROADCAST_SEND_ERROR 0x4 |
38938bfe | 79 | #define NETLINK_RECV_NO_ENOBUFS 0x8 |
77247bbb | 80 | |
035c4c16 | 81 | static inline int netlink_is_kernel(struct sock *sk) |
aed81560 DL |
82 | { |
83 | return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET; | |
84 | } | |
85 | ||
0f29c768 AV |
86 | struct netlink_table *nl_table; |
87 | EXPORT_SYMBOL_GPL(nl_table); | |
1da177e4 LT |
88 | |
89 | static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); | |
90 | ||
91 | static int netlink_dump(struct sock *sk); | |
1da177e4 | 92 | |
0f29c768 AV |
93 | DEFINE_RWLOCK(nl_table_lock); |
94 | EXPORT_SYMBOL_GPL(nl_table_lock); | |
1da177e4 LT |
95 | static atomic_t nl_table_users = ATOMIC_INIT(0); |
96 | ||
6d772ac5 ED |
97 | #define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock)); |
98 | ||
e041c683 | 99 | static ATOMIC_NOTIFIER_HEAD(netlink_chain); |
1da177e4 | 100 | |
b57ef81f | 101 | static inline u32 netlink_group_mask(u32 group) |
d629b836 PM |
102 | { |
103 | return group ? 1 << (group - 1) : 0; | |
104 | } | |
105 | ||
15e47304 | 106 | static inline struct hlist_head *nl_portid_hashfn(struct nl_portid_hash *hash, u32 portid) |
1da177e4 | 107 | { |
15e47304 | 108 | return &hash->table[jhash_1word(portid, hash->rnd) & hash->mask]; |
1da177e4 LT |
109 | } |
110 | ||
ccdfcc39 PM |
111 | #ifdef CONFIG_NETLINK_MMAP |
112 | static __pure struct page *pgvec_to_page(const void *addr) | |
113 | { | |
114 | if (is_vmalloc_addr(addr)) | |
115 | return vmalloc_to_page(addr); | |
116 | else | |
117 | return virt_to_page(addr); | |
118 | } | |
119 | ||
120 | static void free_pg_vec(void **pg_vec, unsigned int order, unsigned int len) | |
121 | { | |
122 | unsigned int i; | |
123 | ||
124 | for (i = 0; i < len; i++) { | |
125 | if (pg_vec[i] != NULL) { | |
126 | if (is_vmalloc_addr(pg_vec[i])) | |
127 | vfree(pg_vec[i]); | |
128 | else | |
129 | free_pages((unsigned long)pg_vec[i], order); | |
130 | } | |
131 | } | |
132 | kfree(pg_vec); | |
133 | } | |
134 | ||
135 | static void *alloc_one_pg_vec_page(unsigned long order) | |
136 | { | |
137 | void *buffer; | |
138 | gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | __GFP_ZERO | | |
139 | __GFP_NOWARN | __GFP_NORETRY; | |
140 | ||
141 | buffer = (void *)__get_free_pages(gfp_flags, order); | |
142 | if (buffer != NULL) | |
143 | return buffer; | |
144 | ||
145 | buffer = vzalloc((1 << order) * PAGE_SIZE); | |
146 | if (buffer != NULL) | |
147 | return buffer; | |
148 | ||
149 | gfp_flags &= ~__GFP_NORETRY; | |
150 | return (void *)__get_free_pages(gfp_flags, order); | |
151 | } | |
152 | ||
153 | static void **alloc_pg_vec(struct netlink_sock *nlk, | |
154 | struct nl_mmap_req *req, unsigned int order) | |
155 | { | |
156 | unsigned int block_nr = req->nm_block_nr; | |
157 | unsigned int i; | |
158 | void **pg_vec, *ptr; | |
159 | ||
160 | pg_vec = kcalloc(block_nr, sizeof(void *), GFP_KERNEL); | |
161 | if (pg_vec == NULL) | |
162 | return NULL; | |
163 | ||
164 | for (i = 0; i < block_nr; i++) { | |
165 | pg_vec[i] = ptr = alloc_one_pg_vec_page(order); | |
166 | if (pg_vec[i] == NULL) | |
167 | goto err1; | |
168 | } | |
169 | ||
170 | return pg_vec; | |
171 | err1: | |
172 | free_pg_vec(pg_vec, order, block_nr); | |
173 | return NULL; | |
174 | } | |
175 | ||
176 | static int netlink_set_ring(struct sock *sk, struct nl_mmap_req *req, | |
177 | bool closing, bool tx_ring) | |
178 | { | |
179 | struct netlink_sock *nlk = nlk_sk(sk); | |
180 | struct netlink_ring *ring; | |
181 | struct sk_buff_head *queue; | |
182 | void **pg_vec = NULL; | |
183 | unsigned int order = 0; | |
184 | int err; | |
185 | ||
186 | ring = tx_ring ? &nlk->tx_ring : &nlk->rx_ring; | |
187 | queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; | |
188 | ||
189 | if (!closing) { | |
190 | if (atomic_read(&nlk->mapped)) | |
191 | return -EBUSY; | |
192 | if (atomic_read(&ring->pending)) | |
193 | return -EBUSY; | |
194 | } | |
195 | ||
196 | if (req->nm_block_nr) { | |
197 | if (ring->pg_vec != NULL) | |
198 | return -EBUSY; | |
199 | ||
200 | if ((int)req->nm_block_size <= 0) | |
201 | return -EINVAL; | |
202 | if (!IS_ALIGNED(req->nm_block_size, PAGE_SIZE)) | |
203 | return -EINVAL; | |
204 | if (req->nm_frame_size < NL_MMAP_HDRLEN) | |
205 | return -EINVAL; | |
206 | if (!IS_ALIGNED(req->nm_frame_size, NL_MMAP_MSG_ALIGNMENT)) | |
207 | return -EINVAL; | |
208 | ||
209 | ring->frames_per_block = req->nm_block_size / | |
210 | req->nm_frame_size; | |
211 | if (ring->frames_per_block == 0) | |
212 | return -EINVAL; | |
213 | if (ring->frames_per_block * req->nm_block_nr != | |
214 | req->nm_frame_nr) | |
215 | return -EINVAL; | |
216 | ||
217 | order = get_order(req->nm_block_size); | |
218 | pg_vec = alloc_pg_vec(nlk, req, order); | |
219 | if (pg_vec == NULL) | |
220 | return -ENOMEM; | |
221 | } else { | |
222 | if (req->nm_frame_nr) | |
223 | return -EINVAL; | |
224 | } | |
225 | ||
226 | err = -EBUSY; | |
227 | mutex_lock(&nlk->pg_vec_lock); | |
228 | if (closing || atomic_read(&nlk->mapped) == 0) { | |
229 | err = 0; | |
230 | spin_lock_bh(&queue->lock); | |
231 | ||
232 | ring->frame_max = req->nm_frame_nr - 1; | |
233 | ring->head = 0; | |
234 | ring->frame_size = req->nm_frame_size; | |
235 | ring->pg_vec_pages = req->nm_block_size / PAGE_SIZE; | |
236 | ||
237 | swap(ring->pg_vec_len, req->nm_block_nr); | |
238 | swap(ring->pg_vec_order, order); | |
239 | swap(ring->pg_vec, pg_vec); | |
240 | ||
241 | __skb_queue_purge(queue); | |
242 | spin_unlock_bh(&queue->lock); | |
243 | ||
244 | WARN_ON(atomic_read(&nlk->mapped)); | |
245 | } | |
246 | mutex_unlock(&nlk->pg_vec_lock); | |
247 | ||
248 | if (pg_vec) | |
249 | free_pg_vec(pg_vec, order, req->nm_block_nr); | |
250 | return err; | |
251 | } | |
252 | ||
253 | static void netlink_mm_open(struct vm_area_struct *vma) | |
254 | { | |
255 | struct file *file = vma->vm_file; | |
256 | struct socket *sock = file->private_data; | |
257 | struct sock *sk = sock->sk; | |
258 | ||
259 | if (sk) | |
260 | atomic_inc(&nlk_sk(sk)->mapped); | |
261 | } | |
262 | ||
263 | static void netlink_mm_close(struct vm_area_struct *vma) | |
264 | { | |
265 | struct file *file = vma->vm_file; | |
266 | struct socket *sock = file->private_data; | |
267 | struct sock *sk = sock->sk; | |
268 | ||
269 | if (sk) | |
270 | atomic_dec(&nlk_sk(sk)->mapped); | |
271 | } | |
272 | ||
273 | static const struct vm_operations_struct netlink_mmap_ops = { | |
274 | .open = netlink_mm_open, | |
275 | .close = netlink_mm_close, | |
276 | }; | |
277 | ||
278 | static int netlink_mmap(struct file *file, struct socket *sock, | |
279 | struct vm_area_struct *vma) | |
280 | { | |
281 | struct sock *sk = sock->sk; | |
282 | struct netlink_sock *nlk = nlk_sk(sk); | |
283 | struct netlink_ring *ring; | |
284 | unsigned long start, size, expected; | |
285 | unsigned int i; | |
286 | int err = -EINVAL; | |
287 | ||
288 | if (vma->vm_pgoff) | |
289 | return -EINVAL; | |
290 | ||
291 | mutex_lock(&nlk->pg_vec_lock); | |
292 | ||
293 | expected = 0; | |
294 | for (ring = &nlk->rx_ring; ring <= &nlk->tx_ring; ring++) { | |
295 | if (ring->pg_vec == NULL) | |
296 | continue; | |
297 | expected += ring->pg_vec_len * ring->pg_vec_pages * PAGE_SIZE; | |
298 | } | |
299 | ||
300 | if (expected == 0) | |
301 | goto out; | |
302 | ||
303 | size = vma->vm_end - vma->vm_start; | |
304 | if (size != expected) | |
305 | goto out; | |
306 | ||
307 | start = vma->vm_start; | |
308 | for (ring = &nlk->rx_ring; ring <= &nlk->tx_ring; ring++) { | |
309 | if (ring->pg_vec == NULL) | |
310 | continue; | |
311 | ||
312 | for (i = 0; i < ring->pg_vec_len; i++) { | |
313 | struct page *page; | |
314 | void *kaddr = ring->pg_vec[i]; | |
315 | unsigned int pg_num; | |
316 | ||
317 | for (pg_num = 0; pg_num < ring->pg_vec_pages; pg_num++) { | |
318 | page = pgvec_to_page(kaddr); | |
319 | err = vm_insert_page(vma, start, page); | |
320 | if (err < 0) | |
321 | goto out; | |
322 | start += PAGE_SIZE; | |
323 | kaddr += PAGE_SIZE; | |
324 | } | |
325 | } | |
326 | } | |
327 | ||
328 | atomic_inc(&nlk->mapped); | |
329 | vma->vm_ops = &netlink_mmap_ops; | |
330 | err = 0; | |
331 | out: | |
332 | mutex_unlock(&nlk->pg_vec_lock); | |
333 | return 0; | |
334 | } | |
335 | #else /* CONFIG_NETLINK_MMAP */ | |
336 | #define netlink_mmap sock_no_mmap | |
337 | #endif /* CONFIG_NETLINK_MMAP */ | |
338 | ||
658cb354 ED |
339 | static void netlink_destroy_callback(struct netlink_callback *cb) |
340 | { | |
341 | kfree_skb(cb->skb); | |
342 | kfree(cb); | |
343 | } | |
344 | ||
bfb253c9 ED |
345 | static void netlink_consume_callback(struct netlink_callback *cb) |
346 | { | |
347 | consume_skb(cb->skb); | |
348 | kfree(cb); | |
349 | } | |
350 | ||
cf0a018a PM |
351 | static void netlink_skb_destructor(struct sk_buff *skb) |
352 | { | |
353 | sock_rfree(skb); | |
354 | } | |
355 | ||
356 | static void netlink_skb_set_owner_r(struct sk_buff *skb, struct sock *sk) | |
357 | { | |
358 | WARN_ON(skb->sk != NULL); | |
359 | skb->sk = sk; | |
360 | skb->destructor = netlink_skb_destructor; | |
361 | atomic_add(skb->truesize, &sk->sk_rmem_alloc); | |
362 | sk_mem_charge(sk, skb->truesize); | |
363 | } | |
364 | ||
1da177e4 LT |
365 | static void netlink_sock_destruct(struct sock *sk) |
366 | { | |
3f660d66 HX |
367 | struct netlink_sock *nlk = nlk_sk(sk); |
368 | ||
3f660d66 HX |
369 | if (nlk->cb) { |
370 | if (nlk->cb->done) | |
371 | nlk->cb->done(nlk->cb); | |
6dc878a8 G |
372 | |
373 | module_put(nlk->cb->module); | |
3f660d66 HX |
374 | netlink_destroy_callback(nlk->cb); |
375 | } | |
376 | ||
1da177e4 | 377 | skb_queue_purge(&sk->sk_receive_queue); |
ccdfcc39 PM |
378 | #ifdef CONFIG_NETLINK_MMAP |
379 | if (1) { | |
380 | struct nl_mmap_req req; | |
381 | ||
382 | memset(&req, 0, sizeof(req)); | |
383 | if (nlk->rx_ring.pg_vec) | |
384 | netlink_set_ring(sk, &req, true, false); | |
385 | memset(&req, 0, sizeof(req)); | |
386 | if (nlk->tx_ring.pg_vec) | |
387 | netlink_set_ring(sk, &req, true, true); | |
388 | } | |
389 | #endif /* CONFIG_NETLINK_MMAP */ | |
1da177e4 LT |
390 | |
391 | if (!sock_flag(sk, SOCK_DEAD)) { | |
6ac552fd | 392 | printk(KERN_ERR "Freeing alive netlink socket %p\n", sk); |
1da177e4 LT |
393 | return; |
394 | } | |
547b792c IJ |
395 | |
396 | WARN_ON(atomic_read(&sk->sk_rmem_alloc)); | |
397 | WARN_ON(atomic_read(&sk->sk_wmem_alloc)); | |
398 | WARN_ON(nlk_sk(sk)->groups); | |
1da177e4 LT |
399 | } |
400 | ||
6ac552fd PM |
401 | /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on |
402 | * SMP. Look, when several writers sleep and reader wakes them up, all but one | |
1da177e4 LT |
403 | * immediately hit write lock and grab all the cpus. Exclusive sleep solves |
404 | * this, _but_ remember, it adds useless work on UP machines. | |
405 | */ | |
406 | ||
d136f1bd | 407 | void netlink_table_grab(void) |
9a429c49 | 408 | __acquires(nl_table_lock) |
1da177e4 | 409 | { |
d136f1bd JB |
410 | might_sleep(); |
411 | ||
6abd219c | 412 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
413 | |
414 | if (atomic_read(&nl_table_users)) { | |
415 | DECLARE_WAITQUEUE(wait, current); | |
416 | ||
417 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
6ac552fd | 418 | for (;;) { |
1da177e4 LT |
419 | set_current_state(TASK_UNINTERRUPTIBLE); |
420 | if (atomic_read(&nl_table_users) == 0) | |
421 | break; | |
6abd219c | 422 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 423 | schedule(); |
6abd219c | 424 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
425 | } |
426 | ||
427 | __set_current_state(TASK_RUNNING); | |
428 | remove_wait_queue(&nl_table_wait, &wait); | |
429 | } | |
430 | } | |
431 | ||
d136f1bd | 432 | void netlink_table_ungrab(void) |
9a429c49 | 433 | __releases(nl_table_lock) |
1da177e4 | 434 | { |
6abd219c | 435 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
436 | wake_up(&nl_table_wait); |
437 | } | |
438 | ||
6ac552fd | 439 | static inline void |
1da177e4 LT |
440 | netlink_lock_table(void) |
441 | { | |
442 | /* read_lock() synchronizes us to netlink_table_grab */ | |
443 | ||
444 | read_lock(&nl_table_lock); | |
445 | atomic_inc(&nl_table_users); | |
446 | read_unlock(&nl_table_lock); | |
447 | } | |
448 | ||
6ac552fd | 449 | static inline void |
1da177e4 LT |
450 | netlink_unlock_table(void) |
451 | { | |
452 | if (atomic_dec_and_test(&nl_table_users)) | |
453 | wake_up(&nl_table_wait); | |
454 | } | |
455 | ||
15e47304 | 456 | static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid) |
1da177e4 | 457 | { |
15e47304 | 458 | struct nl_portid_hash *hash = &nl_table[protocol].hash; |
1da177e4 LT |
459 | struct hlist_head *head; |
460 | struct sock *sk; | |
1da177e4 LT |
461 | |
462 | read_lock(&nl_table_lock); | |
15e47304 | 463 | head = nl_portid_hashfn(hash, portid); |
b67bfe0d | 464 | sk_for_each(sk, head) { |
15e47304 | 465 | if (net_eq(sock_net(sk), net) && (nlk_sk(sk)->portid == portid)) { |
1da177e4 LT |
466 | sock_hold(sk); |
467 | goto found; | |
468 | } | |
469 | } | |
470 | sk = NULL; | |
471 | found: | |
472 | read_unlock(&nl_table_lock); | |
473 | return sk; | |
474 | } | |
475 | ||
15e47304 | 476 | static struct hlist_head *nl_portid_hash_zalloc(size_t size) |
1da177e4 LT |
477 | { |
478 | if (size <= PAGE_SIZE) | |
ea72912c | 479 | return kzalloc(size, GFP_ATOMIC); |
1da177e4 LT |
480 | else |
481 | return (struct hlist_head *) | |
ea72912c ED |
482 | __get_free_pages(GFP_ATOMIC | __GFP_ZERO, |
483 | get_order(size)); | |
1da177e4 LT |
484 | } |
485 | ||
15e47304 | 486 | static void nl_portid_hash_free(struct hlist_head *table, size_t size) |
1da177e4 LT |
487 | { |
488 | if (size <= PAGE_SIZE) | |
489 | kfree(table); | |
490 | else | |
491 | free_pages((unsigned long)table, get_order(size)); | |
492 | } | |
493 | ||
15e47304 | 494 | static int nl_portid_hash_rehash(struct nl_portid_hash *hash, int grow) |
1da177e4 LT |
495 | { |
496 | unsigned int omask, mask, shift; | |
497 | size_t osize, size; | |
498 | struct hlist_head *otable, *table; | |
499 | int i; | |
500 | ||
501 | omask = mask = hash->mask; | |
502 | osize = size = (mask + 1) * sizeof(*table); | |
503 | shift = hash->shift; | |
504 | ||
505 | if (grow) { | |
506 | if (++shift > hash->max_shift) | |
507 | return 0; | |
508 | mask = mask * 2 + 1; | |
509 | size *= 2; | |
510 | } | |
511 | ||
15e47304 | 512 | table = nl_portid_hash_zalloc(size); |
1da177e4 LT |
513 | if (!table) |
514 | return 0; | |
515 | ||
1da177e4 LT |
516 | otable = hash->table; |
517 | hash->table = table; | |
518 | hash->mask = mask; | |
519 | hash->shift = shift; | |
520 | get_random_bytes(&hash->rnd, sizeof(hash->rnd)); | |
521 | ||
522 | for (i = 0; i <= omask; i++) { | |
523 | struct sock *sk; | |
b67bfe0d | 524 | struct hlist_node *tmp; |
1da177e4 | 525 | |
b67bfe0d | 526 | sk_for_each_safe(sk, tmp, &otable[i]) |
15e47304 | 527 | __sk_add_node(sk, nl_portid_hashfn(hash, nlk_sk(sk)->portid)); |
1da177e4 LT |
528 | } |
529 | ||
15e47304 | 530 | nl_portid_hash_free(otable, osize); |
1da177e4 LT |
531 | hash->rehash_time = jiffies + 10 * 60 * HZ; |
532 | return 1; | |
533 | } | |
534 | ||
15e47304 | 535 | static inline int nl_portid_hash_dilute(struct nl_portid_hash *hash, int len) |
1da177e4 LT |
536 | { |
537 | int avg = hash->entries >> hash->shift; | |
538 | ||
15e47304 | 539 | if (unlikely(avg > 1) && nl_portid_hash_rehash(hash, 1)) |
1da177e4 LT |
540 | return 1; |
541 | ||
542 | if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) { | |
15e47304 | 543 | nl_portid_hash_rehash(hash, 0); |
1da177e4 LT |
544 | return 1; |
545 | } | |
546 | ||
547 | return 0; | |
548 | } | |
549 | ||
90ddc4f0 | 550 | static const struct proto_ops netlink_ops; |
1da177e4 | 551 | |
4277a083 PM |
552 | static void |
553 | netlink_update_listeners(struct sock *sk) | |
554 | { | |
555 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
4277a083 PM |
556 | unsigned long mask; |
557 | unsigned int i; | |
6d772ac5 ED |
558 | struct listeners *listeners; |
559 | ||
560 | listeners = nl_deref_protected(tbl->listeners); | |
561 | if (!listeners) | |
562 | return; | |
4277a083 | 563 | |
b4ff4f04 | 564 | for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
4277a083 | 565 | mask = 0; |
b67bfe0d | 566 | sk_for_each_bound(sk, &tbl->mc_list) { |
b4ff4f04 JB |
567 | if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) |
568 | mask |= nlk_sk(sk)->groups[i]; | |
569 | } | |
6d772ac5 | 570 | listeners->masks[i] = mask; |
4277a083 PM |
571 | } |
572 | /* this function is only called with the netlink table "grabbed", which | |
573 | * makes sure updates are visible before bind or setsockopt return. */ | |
574 | } | |
575 | ||
15e47304 | 576 | static int netlink_insert(struct sock *sk, struct net *net, u32 portid) |
1da177e4 | 577 | { |
15e47304 | 578 | struct nl_portid_hash *hash = &nl_table[sk->sk_protocol].hash; |
1da177e4 LT |
579 | struct hlist_head *head; |
580 | int err = -EADDRINUSE; | |
581 | struct sock *osk; | |
1da177e4 LT |
582 | int len; |
583 | ||
584 | netlink_table_grab(); | |
15e47304 | 585 | head = nl_portid_hashfn(hash, portid); |
1da177e4 | 586 | len = 0; |
b67bfe0d | 587 | sk_for_each(osk, head) { |
15e47304 | 588 | if (net_eq(sock_net(osk), net) && (nlk_sk(osk)->portid == portid)) |
1da177e4 LT |
589 | break; |
590 | len++; | |
591 | } | |
b67bfe0d | 592 | if (osk) |
1da177e4 LT |
593 | goto err; |
594 | ||
595 | err = -EBUSY; | |
15e47304 | 596 | if (nlk_sk(sk)->portid) |
1da177e4 LT |
597 | goto err; |
598 | ||
599 | err = -ENOMEM; | |
600 | if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX)) | |
601 | goto err; | |
602 | ||
15e47304 EB |
603 | if (len && nl_portid_hash_dilute(hash, len)) |
604 | head = nl_portid_hashfn(hash, portid); | |
1da177e4 | 605 | hash->entries++; |
15e47304 | 606 | nlk_sk(sk)->portid = portid; |
1da177e4 LT |
607 | sk_add_node(sk, head); |
608 | err = 0; | |
609 | ||
610 | err: | |
611 | netlink_table_ungrab(); | |
612 | return err; | |
613 | } | |
614 | ||
615 | static void netlink_remove(struct sock *sk) | |
616 | { | |
617 | netlink_table_grab(); | |
d470e3b4 DM |
618 | if (sk_del_node_init(sk)) |
619 | nl_table[sk->sk_protocol].hash.entries--; | |
f7fa9b10 | 620 | if (nlk_sk(sk)->subscriptions) |
1da177e4 LT |
621 | __sk_del_bind_node(sk); |
622 | netlink_table_ungrab(); | |
623 | } | |
624 | ||
625 | static struct proto netlink_proto = { | |
626 | .name = "NETLINK", | |
627 | .owner = THIS_MODULE, | |
628 | .obj_size = sizeof(struct netlink_sock), | |
629 | }; | |
630 | ||
1b8d7ae4 EB |
631 | static int __netlink_create(struct net *net, struct socket *sock, |
632 | struct mutex *cb_mutex, int protocol) | |
1da177e4 LT |
633 | { |
634 | struct sock *sk; | |
635 | struct netlink_sock *nlk; | |
ab33a171 PM |
636 | |
637 | sock->ops = &netlink_ops; | |
638 | ||
6257ff21 | 639 | sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto); |
ab33a171 PM |
640 | if (!sk) |
641 | return -ENOMEM; | |
642 | ||
643 | sock_init_data(sock, sk); | |
644 | ||
645 | nlk = nlk_sk(sk); | |
658cb354 | 646 | if (cb_mutex) { |
ffa4d721 | 647 | nlk->cb_mutex = cb_mutex; |
658cb354 | 648 | } else { |
ffa4d721 PM |
649 | nlk->cb_mutex = &nlk->cb_def_mutex; |
650 | mutex_init(nlk->cb_mutex); | |
651 | } | |
ab33a171 | 652 | init_waitqueue_head(&nlk->wait); |
ccdfcc39 PM |
653 | #ifdef CONFIG_NETLINK_MMAP |
654 | mutex_init(&nlk->pg_vec_lock); | |
655 | #endif | |
ab33a171 PM |
656 | |
657 | sk->sk_destruct = netlink_sock_destruct; | |
658 | sk->sk_protocol = protocol; | |
659 | return 0; | |
660 | } | |
661 | ||
3f378b68 EP |
662 | static int netlink_create(struct net *net, struct socket *sock, int protocol, |
663 | int kern) | |
ab33a171 PM |
664 | { |
665 | struct module *module = NULL; | |
af65bdfc | 666 | struct mutex *cb_mutex; |
f7fa9b10 | 667 | struct netlink_sock *nlk; |
03292745 | 668 | void (*bind)(int group); |
ab33a171 | 669 | int err = 0; |
1da177e4 LT |
670 | |
671 | sock->state = SS_UNCONNECTED; | |
672 | ||
673 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
674 | return -ESOCKTNOSUPPORT; | |
675 | ||
6ac552fd | 676 | if (protocol < 0 || protocol >= MAX_LINKS) |
1da177e4 LT |
677 | return -EPROTONOSUPPORT; |
678 | ||
77247bbb | 679 | netlink_lock_table(); |
95a5afca | 680 | #ifdef CONFIG_MODULES |
ab33a171 | 681 | if (!nl_table[protocol].registered) { |
77247bbb | 682 | netlink_unlock_table(); |
4fdb3bb7 | 683 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 684 | netlink_lock_table(); |
4fdb3bb7 | 685 | } |
ab33a171 PM |
686 | #endif |
687 | if (nl_table[protocol].registered && | |
688 | try_module_get(nl_table[protocol].module)) | |
689 | module = nl_table[protocol].module; | |
974c37e9 AD |
690 | else |
691 | err = -EPROTONOSUPPORT; | |
af65bdfc | 692 | cb_mutex = nl_table[protocol].cb_mutex; |
03292745 | 693 | bind = nl_table[protocol].bind; |
77247bbb | 694 | netlink_unlock_table(); |
4fdb3bb7 | 695 | |
974c37e9 AD |
696 | if (err < 0) |
697 | goto out; | |
698 | ||
6ac552fd PM |
699 | err = __netlink_create(net, sock, cb_mutex, protocol); |
700 | if (err < 0) | |
f7fa9b10 PM |
701 | goto out_module; |
702 | ||
6f756a8c | 703 | local_bh_disable(); |
c1fd3b94 | 704 | sock_prot_inuse_add(net, &netlink_proto, 1); |
6f756a8c DM |
705 | local_bh_enable(); |
706 | ||
f7fa9b10 | 707 | nlk = nlk_sk(sock->sk); |
f7fa9b10 | 708 | nlk->module = module; |
03292745 | 709 | nlk->netlink_bind = bind; |
ab33a171 PM |
710 | out: |
711 | return err; | |
1da177e4 | 712 | |
ab33a171 PM |
713 | out_module: |
714 | module_put(module); | |
715 | goto out; | |
1da177e4 LT |
716 | } |
717 | ||
718 | static int netlink_release(struct socket *sock) | |
719 | { | |
720 | struct sock *sk = sock->sk; | |
721 | struct netlink_sock *nlk; | |
722 | ||
723 | if (!sk) | |
724 | return 0; | |
725 | ||
726 | netlink_remove(sk); | |
ac57b3a9 | 727 | sock_orphan(sk); |
1da177e4 LT |
728 | nlk = nlk_sk(sk); |
729 | ||
3f660d66 HX |
730 | /* |
731 | * OK. Socket is unlinked, any packets that arrive now | |
732 | * will be purged. | |
733 | */ | |
1da177e4 | 734 | |
1da177e4 LT |
735 | sock->sk = NULL; |
736 | wake_up_interruptible_all(&nlk->wait); | |
737 | ||
738 | skb_queue_purge(&sk->sk_write_queue); | |
739 | ||
15e47304 | 740 | if (nlk->portid) { |
1da177e4 | 741 | struct netlink_notify n = { |
3b1e0a65 | 742 | .net = sock_net(sk), |
1da177e4 | 743 | .protocol = sk->sk_protocol, |
15e47304 | 744 | .portid = nlk->portid, |
1da177e4 | 745 | }; |
e041c683 AS |
746 | atomic_notifier_call_chain(&netlink_chain, |
747 | NETLINK_URELEASE, &n); | |
746fac4d | 748 | } |
4fdb3bb7 | 749 | |
5e7c001c | 750 | module_put(nlk->module); |
4fdb3bb7 | 751 | |
4277a083 | 752 | netlink_table_grab(); |
aed81560 | 753 | if (netlink_is_kernel(sk)) { |
869e58f8 DL |
754 | BUG_ON(nl_table[sk->sk_protocol].registered == 0); |
755 | if (--nl_table[sk->sk_protocol].registered == 0) { | |
6d772ac5 ED |
756 | struct listeners *old; |
757 | ||
758 | old = nl_deref_protected(nl_table[sk->sk_protocol].listeners); | |
759 | RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL); | |
760 | kfree_rcu(old, rcu); | |
869e58f8 | 761 | nl_table[sk->sk_protocol].module = NULL; |
9785e10a PNA |
762 | nl_table[sk->sk_protocol].bind = NULL; |
763 | nl_table[sk->sk_protocol].flags = 0; | |
869e58f8 DL |
764 | nl_table[sk->sk_protocol].registered = 0; |
765 | } | |
658cb354 | 766 | } else if (nlk->subscriptions) { |
4277a083 | 767 | netlink_update_listeners(sk); |
658cb354 | 768 | } |
4277a083 | 769 | netlink_table_ungrab(); |
77247bbb | 770 | |
f7fa9b10 PM |
771 | kfree(nlk->groups); |
772 | nlk->groups = NULL; | |
773 | ||
3755810c | 774 | local_bh_disable(); |
c1fd3b94 | 775 | sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); |
3755810c | 776 | local_bh_enable(); |
1da177e4 LT |
777 | sock_put(sk); |
778 | return 0; | |
779 | } | |
780 | ||
781 | static int netlink_autobind(struct socket *sock) | |
782 | { | |
783 | struct sock *sk = sock->sk; | |
3b1e0a65 | 784 | struct net *net = sock_net(sk); |
15e47304 | 785 | struct nl_portid_hash *hash = &nl_table[sk->sk_protocol].hash; |
1da177e4 LT |
786 | struct hlist_head *head; |
787 | struct sock *osk; | |
15e47304 | 788 | s32 portid = task_tgid_vnr(current); |
1da177e4 LT |
789 | int err; |
790 | static s32 rover = -4097; | |
791 | ||
792 | retry: | |
793 | cond_resched(); | |
794 | netlink_table_grab(); | |
15e47304 | 795 | head = nl_portid_hashfn(hash, portid); |
b67bfe0d | 796 | sk_for_each(osk, head) { |
878628fb | 797 | if (!net_eq(sock_net(osk), net)) |
b4b51029 | 798 | continue; |
15e47304 EB |
799 | if (nlk_sk(osk)->portid == portid) { |
800 | /* Bind collision, search negative portid values. */ | |
801 | portid = rover--; | |
1da177e4 LT |
802 | if (rover > -4097) |
803 | rover = -4097; | |
804 | netlink_table_ungrab(); | |
805 | goto retry; | |
806 | } | |
807 | } | |
808 | netlink_table_ungrab(); | |
809 | ||
15e47304 | 810 | err = netlink_insert(sk, net, portid); |
1da177e4 LT |
811 | if (err == -EADDRINUSE) |
812 | goto retry; | |
d470e3b4 DM |
813 | |
814 | /* If 2 threads race to autobind, that is fine. */ | |
815 | if (err == -EBUSY) | |
816 | err = 0; | |
817 | ||
818 | return err; | |
1da177e4 LT |
819 | } |
820 | ||
b57ef81f | 821 | static inline int netlink_capable(const struct socket *sock, unsigned int flag) |
746fac4d | 822 | { |
9785e10a | 823 | return (nl_table[sock->sk->sk_protocol].flags & flag) || |
df008c91 | 824 | ns_capable(sock_net(sock->sk)->user_ns, CAP_NET_ADMIN); |
746fac4d | 825 | } |
1da177e4 | 826 | |
f7fa9b10 PM |
827 | static void |
828 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
829 | { | |
830 | struct netlink_sock *nlk = nlk_sk(sk); | |
831 | ||
832 | if (nlk->subscriptions && !subscriptions) | |
833 | __sk_del_bind_node(sk); | |
834 | else if (!nlk->subscriptions && subscriptions) | |
835 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
836 | nlk->subscriptions = subscriptions; | |
837 | } | |
838 | ||
b4ff4f04 | 839 | static int netlink_realloc_groups(struct sock *sk) |
513c2500 PM |
840 | { |
841 | struct netlink_sock *nlk = nlk_sk(sk); | |
842 | unsigned int groups; | |
b4ff4f04 | 843 | unsigned long *new_groups; |
513c2500 PM |
844 | int err = 0; |
845 | ||
b4ff4f04 JB |
846 | netlink_table_grab(); |
847 | ||
513c2500 | 848 | groups = nl_table[sk->sk_protocol].groups; |
b4ff4f04 | 849 | if (!nl_table[sk->sk_protocol].registered) { |
513c2500 | 850 | err = -ENOENT; |
b4ff4f04 JB |
851 | goto out_unlock; |
852 | } | |
513c2500 | 853 | |
b4ff4f04 JB |
854 | if (nlk->ngroups >= groups) |
855 | goto out_unlock; | |
513c2500 | 856 | |
b4ff4f04 JB |
857 | new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
858 | if (new_groups == NULL) { | |
859 | err = -ENOMEM; | |
860 | goto out_unlock; | |
861 | } | |
6ac552fd | 862 | memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, |
b4ff4f04 JB |
863 | NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); |
864 | ||
865 | nlk->groups = new_groups; | |
513c2500 | 866 | nlk->ngroups = groups; |
b4ff4f04 JB |
867 | out_unlock: |
868 | netlink_table_ungrab(); | |
869 | return err; | |
513c2500 PM |
870 | } |
871 | ||
6ac552fd PM |
872 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, |
873 | int addr_len) | |
1da177e4 LT |
874 | { |
875 | struct sock *sk = sock->sk; | |
3b1e0a65 | 876 | struct net *net = sock_net(sk); |
1da177e4 LT |
877 | struct netlink_sock *nlk = nlk_sk(sk); |
878 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
879 | int err; | |
746fac4d | 880 | |
4e4b5376 HFS |
881 | if (addr_len < sizeof(struct sockaddr_nl)) |
882 | return -EINVAL; | |
883 | ||
1da177e4 LT |
884 | if (nladdr->nl_family != AF_NETLINK) |
885 | return -EINVAL; | |
886 | ||
887 | /* Only superuser is allowed to listen multicasts */ | |
513c2500 | 888 | if (nladdr->nl_groups) { |
9785e10a | 889 | if (!netlink_capable(sock, NL_CFG_F_NONROOT_RECV)) |
513c2500 | 890 | return -EPERM; |
b4ff4f04 JB |
891 | err = netlink_realloc_groups(sk); |
892 | if (err) | |
893 | return err; | |
513c2500 | 894 | } |
1da177e4 | 895 | |
15e47304 EB |
896 | if (nlk->portid) { |
897 | if (nladdr->nl_pid != nlk->portid) | |
1da177e4 LT |
898 | return -EINVAL; |
899 | } else { | |
900 | err = nladdr->nl_pid ? | |
b4b51029 | 901 | netlink_insert(sk, net, nladdr->nl_pid) : |
1da177e4 LT |
902 | netlink_autobind(sock); |
903 | if (err) | |
904 | return err; | |
905 | } | |
906 | ||
513c2500 | 907 | if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
1da177e4 LT |
908 | return 0; |
909 | ||
910 | netlink_table_grab(); | |
f7fa9b10 | 911 | netlink_update_subscriptions(sk, nlk->subscriptions + |
746fac4d YH |
912 | hweight32(nladdr->nl_groups) - |
913 | hweight32(nlk->groups[0])); | |
914 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups; | |
4277a083 | 915 | netlink_update_listeners(sk); |
1da177e4 LT |
916 | netlink_table_ungrab(); |
917 | ||
03292745 PNA |
918 | if (nlk->netlink_bind && nlk->groups[0]) { |
919 | int i; | |
920 | ||
921 | for (i=0; i<nlk->ngroups; i++) { | |
922 | if (test_bit(i, nlk->groups)) | |
923 | nlk->netlink_bind(i); | |
924 | } | |
925 | } | |
926 | ||
1da177e4 LT |
927 | return 0; |
928 | } | |
929 | ||
930 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
931 | int alen, int flags) | |
932 | { | |
933 | int err = 0; | |
934 | struct sock *sk = sock->sk; | |
935 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 936 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
1da177e4 | 937 | |
6503d961 CG |
938 | if (alen < sizeof(addr->sa_family)) |
939 | return -EINVAL; | |
940 | ||
1da177e4 LT |
941 | if (addr->sa_family == AF_UNSPEC) { |
942 | sk->sk_state = NETLINK_UNCONNECTED; | |
15e47304 | 943 | nlk->dst_portid = 0; |
d629b836 | 944 | nlk->dst_group = 0; |
1da177e4 LT |
945 | return 0; |
946 | } | |
947 | if (addr->sa_family != AF_NETLINK) | |
948 | return -EINVAL; | |
949 | ||
950 | /* Only superuser is allowed to send multicasts */ | |
9785e10a | 951 | if (nladdr->nl_groups && !netlink_capable(sock, NL_CFG_F_NONROOT_SEND)) |
1da177e4 LT |
952 | return -EPERM; |
953 | ||
15e47304 | 954 | if (!nlk->portid) |
1da177e4 LT |
955 | err = netlink_autobind(sock); |
956 | ||
957 | if (err == 0) { | |
958 | sk->sk_state = NETLINK_CONNECTED; | |
15e47304 | 959 | nlk->dst_portid = nladdr->nl_pid; |
d629b836 | 960 | nlk->dst_group = ffs(nladdr->nl_groups); |
1da177e4 LT |
961 | } |
962 | ||
963 | return err; | |
964 | } | |
965 | ||
6ac552fd PM |
966 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, |
967 | int *addr_len, int peer) | |
1da177e4 LT |
968 | { |
969 | struct sock *sk = sock->sk; | |
970 | struct netlink_sock *nlk = nlk_sk(sk); | |
13cfa97b | 971 | DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr); |
746fac4d | 972 | |
1da177e4 LT |
973 | nladdr->nl_family = AF_NETLINK; |
974 | nladdr->nl_pad = 0; | |
975 | *addr_len = sizeof(*nladdr); | |
976 | ||
977 | if (peer) { | |
15e47304 | 978 | nladdr->nl_pid = nlk->dst_portid; |
d629b836 | 979 | nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
1da177e4 | 980 | } else { |
15e47304 | 981 | nladdr->nl_pid = nlk->portid; |
513c2500 | 982 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
1da177e4 LT |
983 | } |
984 | return 0; | |
985 | } | |
986 | ||
987 | static void netlink_overrun(struct sock *sk) | |
988 | { | |
38938bfe PNA |
989 | struct netlink_sock *nlk = nlk_sk(sk); |
990 | ||
991 | if (!(nlk->flags & NETLINK_RECV_NO_ENOBUFS)) { | |
cd967e05 | 992 | if (!test_and_set_bit(NETLINK_CONGESTED, &nlk_sk(sk)->state)) { |
38938bfe PNA |
993 | sk->sk_err = ENOBUFS; |
994 | sk->sk_error_report(sk); | |
995 | } | |
1da177e4 | 996 | } |
38938bfe | 997 | atomic_inc(&sk->sk_drops); |
1da177e4 LT |
998 | } |
999 | ||
15e47304 | 1000 | static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid) |
1da177e4 | 1001 | { |
1da177e4 LT |
1002 | struct sock *sock; |
1003 | struct netlink_sock *nlk; | |
1004 | ||
15e47304 | 1005 | sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, portid); |
1da177e4 LT |
1006 | if (!sock) |
1007 | return ERR_PTR(-ECONNREFUSED); | |
1008 | ||
1009 | /* Don't bother queuing skb if kernel socket has no input function */ | |
1010 | nlk = nlk_sk(sock); | |
cd40b7d3 | 1011 | if (sock->sk_state == NETLINK_CONNECTED && |
15e47304 | 1012 | nlk->dst_portid != nlk_sk(ssk)->portid) { |
1da177e4 LT |
1013 | sock_put(sock); |
1014 | return ERR_PTR(-ECONNREFUSED); | |
1015 | } | |
1016 | return sock; | |
1017 | } | |
1018 | ||
1019 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
1020 | { | |
496ad9aa | 1021 | struct inode *inode = file_inode(filp); |
1da177e4 LT |
1022 | struct sock *sock; |
1023 | ||
1024 | if (!S_ISSOCK(inode->i_mode)) | |
1025 | return ERR_PTR(-ENOTSOCK); | |
1026 | ||
1027 | sock = SOCKET_I(inode)->sk; | |
1028 | if (sock->sk_family != AF_NETLINK) | |
1029 | return ERR_PTR(-EINVAL); | |
1030 | ||
1031 | sock_hold(sock); | |
1032 | return sock; | |
1033 | } | |
1034 | ||
1035 | /* | |
1036 | * Attach a skb to a netlink socket. | |
1037 | * The caller must hold a reference to the destination socket. On error, the | |
1038 | * reference is dropped. The skb is not send to the destination, just all | |
1039 | * all error checks are performed and memory in the queue is reserved. | |
1040 | * Return values: | |
1041 | * < 0: error. skb freed, reference to sock dropped. | |
1042 | * 0: continue | |
1043 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
1044 | */ | |
9457afee | 1045 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
c3d8d1e3 | 1046 | long *timeo, struct sock *ssk) |
1da177e4 LT |
1047 | { |
1048 | struct netlink_sock *nlk; | |
1049 | ||
1050 | nlk = nlk_sk(sk); | |
1051 | ||
1052 | if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
cd967e05 | 1053 | test_bit(NETLINK_CONGESTED, &nlk->state)) { |
1da177e4 | 1054 | DECLARE_WAITQUEUE(wait, current); |
c3d8d1e3 | 1055 | if (!*timeo) { |
aed81560 | 1056 | if (!ssk || netlink_is_kernel(ssk)) |
1da177e4 LT |
1057 | netlink_overrun(sk); |
1058 | sock_put(sk); | |
1059 | kfree_skb(skb); | |
1060 | return -EAGAIN; | |
1061 | } | |
1062 | ||
1063 | __set_current_state(TASK_INTERRUPTIBLE); | |
1064 | add_wait_queue(&nlk->wait, &wait); | |
1065 | ||
1066 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
cd967e05 | 1067 | test_bit(NETLINK_CONGESTED, &nlk->state)) && |
1da177e4 | 1068 | !sock_flag(sk, SOCK_DEAD)) |
c3d8d1e3 | 1069 | *timeo = schedule_timeout(*timeo); |
1da177e4 LT |
1070 | |
1071 | __set_current_state(TASK_RUNNING); | |
1072 | remove_wait_queue(&nlk->wait, &wait); | |
1073 | sock_put(sk); | |
1074 | ||
1075 | if (signal_pending(current)) { | |
1076 | kfree_skb(skb); | |
c3d8d1e3 | 1077 | return sock_intr_errno(*timeo); |
1da177e4 LT |
1078 | } |
1079 | return 1; | |
1080 | } | |
cf0a018a | 1081 | netlink_skb_set_owner_r(skb, sk); |
1da177e4 LT |
1082 | return 0; |
1083 | } | |
1084 | ||
4a7e7c2a | 1085 | static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 1086 | { |
1da177e4 LT |
1087 | int len = skb->len; |
1088 | ||
1da177e4 LT |
1089 | skb_queue_tail(&sk->sk_receive_queue, skb); |
1090 | sk->sk_data_ready(sk, len); | |
4a7e7c2a ED |
1091 | return len; |
1092 | } | |
1093 | ||
1094 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb) | |
1095 | { | |
1096 | int len = __netlink_sendskb(sk, skb); | |
1097 | ||
1da177e4 LT |
1098 | sock_put(sk); |
1099 | return len; | |
1100 | } | |
1101 | ||
1102 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
1103 | { | |
1104 | kfree_skb(skb); | |
1105 | sock_put(sk); | |
1106 | } | |
1107 | ||
b57ef81f | 1108 | static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation) |
1da177e4 LT |
1109 | { |
1110 | int delta; | |
1111 | ||
1298ca46 | 1112 | WARN_ON(skb->sk != NULL); |
1da177e4 | 1113 | |
4305b541 | 1114 | delta = skb->end - skb->tail; |
1da177e4 LT |
1115 | if (delta * 2 < skb->truesize) |
1116 | return skb; | |
1117 | ||
1118 | if (skb_shared(skb)) { | |
1119 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
1120 | if (!nskb) | |
1121 | return skb; | |
8460c00f | 1122 | consume_skb(skb); |
1da177e4 LT |
1123 | skb = nskb; |
1124 | } | |
1125 | ||
1126 | if (!pskb_expand_head(skb, 0, -delta, allocation)) | |
1127 | skb->truesize -= delta; | |
1128 | ||
1129 | return skb; | |
1130 | } | |
1131 | ||
b57ef81f | 1132 | static void netlink_rcv_wake(struct sock *sk) |
cd40b7d3 DL |
1133 | { |
1134 | struct netlink_sock *nlk = nlk_sk(sk); | |
1135 | ||
1136 | if (skb_queue_empty(&sk->sk_receive_queue)) | |
cd967e05 PM |
1137 | clear_bit(NETLINK_CONGESTED, &nlk->state); |
1138 | if (!test_bit(NETLINK_CONGESTED, &nlk->state)) | |
cd40b7d3 DL |
1139 | wake_up_interruptible(&nlk->wait); |
1140 | } | |
1141 | ||
3fbc2905 EB |
1142 | static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb, |
1143 | struct sock *ssk) | |
cd40b7d3 DL |
1144 | { |
1145 | int ret; | |
1146 | struct netlink_sock *nlk = nlk_sk(sk); | |
1147 | ||
1148 | ret = -ECONNREFUSED; | |
1149 | if (nlk->netlink_rcv != NULL) { | |
1150 | ret = skb->len; | |
cf0a018a | 1151 | netlink_skb_set_owner_r(skb, sk); |
e32123e5 | 1152 | NETLINK_CB(skb).sk = ssk; |
cd40b7d3 | 1153 | nlk->netlink_rcv(skb); |
bfb253c9 ED |
1154 | consume_skb(skb); |
1155 | } else { | |
1156 | kfree_skb(skb); | |
cd40b7d3 | 1157 | } |
cd40b7d3 DL |
1158 | sock_put(sk); |
1159 | return ret; | |
1160 | } | |
1161 | ||
1162 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, | |
15e47304 | 1163 | u32 portid, int nonblock) |
1da177e4 LT |
1164 | { |
1165 | struct sock *sk; | |
1166 | int err; | |
1167 | long timeo; | |
1168 | ||
1169 | skb = netlink_trim(skb, gfp_any()); | |
1170 | ||
1171 | timeo = sock_sndtimeo(ssk, nonblock); | |
1172 | retry: | |
15e47304 | 1173 | sk = netlink_getsockbyportid(ssk, portid); |
1da177e4 LT |
1174 | if (IS_ERR(sk)) { |
1175 | kfree_skb(skb); | |
1176 | return PTR_ERR(sk); | |
1177 | } | |
cd40b7d3 | 1178 | if (netlink_is_kernel(sk)) |
3fbc2905 | 1179 | return netlink_unicast_kernel(sk, skb, ssk); |
cd40b7d3 | 1180 | |
b1153f29 | 1181 | if (sk_filter(sk, skb)) { |
84874607 | 1182 | err = skb->len; |
b1153f29 SH |
1183 | kfree_skb(skb); |
1184 | sock_put(sk); | |
1185 | return err; | |
1186 | } | |
1187 | ||
9457afee | 1188 | err = netlink_attachskb(sk, skb, &timeo, ssk); |
1da177e4 LT |
1189 | if (err == 1) |
1190 | goto retry; | |
1191 | if (err) | |
1192 | return err; | |
1193 | ||
7ee015e0 | 1194 | return netlink_sendskb(sk, skb); |
1da177e4 | 1195 | } |
6ac552fd | 1196 | EXPORT_SYMBOL(netlink_unicast); |
1da177e4 | 1197 | |
4277a083 PM |
1198 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
1199 | { | |
1200 | int res = 0; | |
5c398dc8 | 1201 | struct listeners *listeners; |
4277a083 | 1202 | |
aed81560 | 1203 | BUG_ON(!netlink_is_kernel(sk)); |
b4ff4f04 JB |
1204 | |
1205 | rcu_read_lock(); | |
1206 | listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); | |
1207 | ||
6d772ac5 | 1208 | if (listeners && group - 1 < nl_table[sk->sk_protocol].groups) |
5c398dc8 | 1209 | res = test_bit(group - 1, listeners->masks); |
b4ff4f04 JB |
1210 | |
1211 | rcu_read_unlock(); | |
1212 | ||
4277a083 PM |
1213 | return res; |
1214 | } | |
1215 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
1216 | ||
b57ef81f | 1217 | static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) |
1da177e4 LT |
1218 | { |
1219 | struct netlink_sock *nlk = nlk_sk(sk); | |
1220 | ||
1221 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
cd967e05 | 1222 | !test_bit(NETLINK_CONGESTED, &nlk->state)) { |
cf0a018a | 1223 | netlink_skb_set_owner_r(skb, sk); |
4a7e7c2a | 1224 | __netlink_sendskb(sk, skb); |
2c645800 | 1225 | return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1); |
1da177e4 LT |
1226 | } |
1227 | return -1; | |
1228 | } | |
1229 | ||
1230 | struct netlink_broadcast_data { | |
1231 | struct sock *exclude_sk; | |
b4b51029 | 1232 | struct net *net; |
15e47304 | 1233 | u32 portid; |
1da177e4 LT |
1234 | u32 group; |
1235 | int failure; | |
ff491a73 | 1236 | int delivery_failure; |
1da177e4 LT |
1237 | int congested; |
1238 | int delivered; | |
7d877f3b | 1239 | gfp_t allocation; |
1da177e4 | 1240 | struct sk_buff *skb, *skb2; |
910a7e90 EB |
1241 | int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data); |
1242 | void *tx_data; | |
1da177e4 LT |
1243 | }; |
1244 | ||
b57ef81f | 1245 | static int do_one_broadcast(struct sock *sk, |
1da177e4 LT |
1246 | struct netlink_broadcast_data *p) |
1247 | { | |
1248 | struct netlink_sock *nlk = nlk_sk(sk); | |
1249 | int val; | |
1250 | ||
1251 | if (p->exclude_sk == sk) | |
1252 | goto out; | |
1253 | ||
15e47304 | 1254 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
f7fa9b10 | 1255 | !test_bit(p->group - 1, nlk->groups)) |
1da177e4 LT |
1256 | goto out; |
1257 | ||
878628fb | 1258 | if (!net_eq(sock_net(sk), p->net)) |
b4b51029 EB |
1259 | goto out; |
1260 | ||
1da177e4 LT |
1261 | if (p->failure) { |
1262 | netlink_overrun(sk); | |
1263 | goto out; | |
1264 | } | |
1265 | ||
1266 | sock_hold(sk); | |
1267 | if (p->skb2 == NULL) { | |
68acc024 | 1268 | if (skb_shared(p->skb)) { |
1da177e4 LT |
1269 | p->skb2 = skb_clone(p->skb, p->allocation); |
1270 | } else { | |
68acc024 TC |
1271 | p->skb2 = skb_get(p->skb); |
1272 | /* | |
1273 | * skb ownership may have been set when | |
1274 | * delivered to a previous socket. | |
1275 | */ | |
1276 | skb_orphan(p->skb2); | |
1da177e4 LT |
1277 | } |
1278 | } | |
1279 | if (p->skb2 == NULL) { | |
1280 | netlink_overrun(sk); | |
1281 | /* Clone failed. Notify ALL listeners. */ | |
1282 | p->failure = 1; | |
be0c22a4 PNA |
1283 | if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) |
1284 | p->delivery_failure = 1; | |
910a7e90 EB |
1285 | } else if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) { |
1286 | kfree_skb(p->skb2); | |
1287 | p->skb2 = NULL; | |
b1153f29 SH |
1288 | } else if (sk_filter(sk, p->skb2)) { |
1289 | kfree_skb(p->skb2); | |
1290 | p->skb2 = NULL; | |
1da177e4 LT |
1291 | } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) { |
1292 | netlink_overrun(sk); | |
be0c22a4 PNA |
1293 | if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) |
1294 | p->delivery_failure = 1; | |
1da177e4 LT |
1295 | } else { |
1296 | p->congested |= val; | |
1297 | p->delivered = 1; | |
1298 | p->skb2 = NULL; | |
1299 | } | |
1300 | sock_put(sk); | |
1301 | ||
1302 | out: | |
1303 | return 0; | |
1304 | } | |
1305 | ||
15e47304 | 1306 | int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 portid, |
910a7e90 EB |
1307 | u32 group, gfp_t allocation, |
1308 | int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data), | |
1309 | void *filter_data) | |
1da177e4 | 1310 | { |
3b1e0a65 | 1311 | struct net *net = sock_net(ssk); |
1da177e4 | 1312 | struct netlink_broadcast_data info; |
1da177e4 LT |
1313 | struct sock *sk; |
1314 | ||
1315 | skb = netlink_trim(skb, allocation); | |
1316 | ||
1317 | info.exclude_sk = ssk; | |
b4b51029 | 1318 | info.net = net; |
15e47304 | 1319 | info.portid = portid; |
1da177e4 LT |
1320 | info.group = group; |
1321 | info.failure = 0; | |
ff491a73 | 1322 | info.delivery_failure = 0; |
1da177e4 LT |
1323 | info.congested = 0; |
1324 | info.delivered = 0; | |
1325 | info.allocation = allocation; | |
1326 | info.skb = skb; | |
1327 | info.skb2 = NULL; | |
910a7e90 EB |
1328 | info.tx_filter = filter; |
1329 | info.tx_data = filter_data; | |
1da177e4 LT |
1330 | |
1331 | /* While we sleep in clone, do not allow to change socket list */ | |
1332 | ||
1333 | netlink_lock_table(); | |
1334 | ||
b67bfe0d | 1335 | sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
1da177e4 LT |
1336 | do_one_broadcast(sk, &info); |
1337 | ||
70d4bf6d | 1338 | consume_skb(skb); |
aa1c6a6f | 1339 | |
1da177e4 LT |
1340 | netlink_unlock_table(); |
1341 | ||
70d4bf6d NH |
1342 | if (info.delivery_failure) { |
1343 | kfree_skb(info.skb2); | |
ff491a73 | 1344 | return -ENOBUFS; |
658cb354 ED |
1345 | } |
1346 | consume_skb(info.skb2); | |
ff491a73 | 1347 | |
1da177e4 LT |
1348 | if (info.delivered) { |
1349 | if (info.congested && (allocation & __GFP_WAIT)) | |
1350 | yield(); | |
1351 | return 0; | |
1352 | } | |
1da177e4 LT |
1353 | return -ESRCH; |
1354 | } | |
910a7e90 EB |
1355 | EXPORT_SYMBOL(netlink_broadcast_filtered); |
1356 | ||
15e47304 | 1357 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 portid, |
910a7e90 EB |
1358 | u32 group, gfp_t allocation) |
1359 | { | |
15e47304 | 1360 | return netlink_broadcast_filtered(ssk, skb, portid, group, allocation, |
910a7e90 EB |
1361 | NULL, NULL); |
1362 | } | |
6ac552fd | 1363 | EXPORT_SYMBOL(netlink_broadcast); |
1da177e4 LT |
1364 | |
1365 | struct netlink_set_err_data { | |
1366 | struct sock *exclude_sk; | |
15e47304 | 1367 | u32 portid; |
1da177e4 LT |
1368 | u32 group; |
1369 | int code; | |
1370 | }; | |
1371 | ||
b57ef81f | 1372 | static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p) |
1da177e4 LT |
1373 | { |
1374 | struct netlink_sock *nlk = nlk_sk(sk); | |
1a50307b | 1375 | int ret = 0; |
1da177e4 LT |
1376 | |
1377 | if (sk == p->exclude_sk) | |
1378 | goto out; | |
1379 | ||
09ad9bc7 | 1380 | if (!net_eq(sock_net(sk), sock_net(p->exclude_sk))) |
b4b51029 EB |
1381 | goto out; |
1382 | ||
15e47304 | 1383 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
f7fa9b10 | 1384 | !test_bit(p->group - 1, nlk->groups)) |
1da177e4 LT |
1385 | goto out; |
1386 | ||
1a50307b PNA |
1387 | if (p->code == ENOBUFS && nlk->flags & NETLINK_RECV_NO_ENOBUFS) { |
1388 | ret = 1; | |
1389 | goto out; | |
1390 | } | |
1391 | ||
1da177e4 LT |
1392 | sk->sk_err = p->code; |
1393 | sk->sk_error_report(sk); | |
1394 | out: | |
1a50307b | 1395 | return ret; |
1da177e4 LT |
1396 | } |
1397 | ||
4843b93c PNA |
1398 | /** |
1399 | * netlink_set_err - report error to broadcast listeners | |
1400 | * @ssk: the kernel netlink socket, as returned by netlink_kernel_create() | |
15e47304 | 1401 | * @portid: the PORTID of a process that we want to skip (if any) |
4843b93c PNA |
1402 | * @groups: the broadcast group that will notice the error |
1403 | * @code: error code, must be negative (as usual in kernelspace) | |
1a50307b PNA |
1404 | * |
1405 | * This function returns the number of broadcast listeners that have set the | |
1406 | * NETLINK_RECV_NO_ENOBUFS socket option. | |
4843b93c | 1407 | */ |
15e47304 | 1408 | int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code) |
1da177e4 LT |
1409 | { |
1410 | struct netlink_set_err_data info; | |
1da177e4 | 1411 | struct sock *sk; |
1a50307b | 1412 | int ret = 0; |
1da177e4 LT |
1413 | |
1414 | info.exclude_sk = ssk; | |
15e47304 | 1415 | info.portid = portid; |
1da177e4 | 1416 | info.group = group; |
4843b93c PNA |
1417 | /* sk->sk_err wants a positive error value */ |
1418 | info.code = -code; | |
1da177e4 LT |
1419 | |
1420 | read_lock(&nl_table_lock); | |
1421 | ||
b67bfe0d | 1422 | sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
1a50307b | 1423 | ret += do_one_set_err(sk, &info); |
1da177e4 LT |
1424 | |
1425 | read_unlock(&nl_table_lock); | |
1a50307b | 1426 | return ret; |
1da177e4 | 1427 | } |
dd5b6ce6 | 1428 | EXPORT_SYMBOL(netlink_set_err); |
1da177e4 | 1429 | |
84659eb5 JB |
1430 | /* must be called with netlink table grabbed */ |
1431 | static void netlink_update_socket_mc(struct netlink_sock *nlk, | |
1432 | unsigned int group, | |
1433 | int is_new) | |
1434 | { | |
1435 | int old, new = !!is_new, subscriptions; | |
1436 | ||
1437 | old = test_bit(group - 1, nlk->groups); | |
1438 | subscriptions = nlk->subscriptions - old + new; | |
1439 | if (new) | |
1440 | __set_bit(group - 1, nlk->groups); | |
1441 | else | |
1442 | __clear_bit(group - 1, nlk->groups); | |
1443 | netlink_update_subscriptions(&nlk->sk, subscriptions); | |
1444 | netlink_update_listeners(&nlk->sk); | |
1445 | } | |
1446 | ||
9a4595bc | 1447 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
b7058842 | 1448 | char __user *optval, unsigned int optlen) |
9a4595bc PM |
1449 | { |
1450 | struct sock *sk = sock->sk; | |
1451 | struct netlink_sock *nlk = nlk_sk(sk); | |
eb496534 JB |
1452 | unsigned int val = 0; |
1453 | int err; | |
9a4595bc PM |
1454 | |
1455 | if (level != SOL_NETLINK) | |
1456 | return -ENOPROTOOPT; | |
1457 | ||
ccdfcc39 PM |
1458 | if (optname != NETLINK_RX_RING && optname != NETLINK_TX_RING && |
1459 | optlen >= sizeof(int) && | |
eb496534 | 1460 | get_user(val, (unsigned int __user *)optval)) |
9a4595bc PM |
1461 | return -EFAULT; |
1462 | ||
1463 | switch (optname) { | |
1464 | case NETLINK_PKTINFO: | |
1465 | if (val) | |
1466 | nlk->flags |= NETLINK_RECV_PKTINFO; | |
1467 | else | |
1468 | nlk->flags &= ~NETLINK_RECV_PKTINFO; | |
1469 | err = 0; | |
1470 | break; | |
1471 | case NETLINK_ADD_MEMBERSHIP: | |
1472 | case NETLINK_DROP_MEMBERSHIP: { | |
9785e10a | 1473 | if (!netlink_capable(sock, NL_CFG_F_NONROOT_RECV)) |
9a4595bc | 1474 | return -EPERM; |
b4ff4f04 JB |
1475 | err = netlink_realloc_groups(sk); |
1476 | if (err) | |
1477 | return err; | |
9a4595bc PM |
1478 | if (!val || val - 1 >= nlk->ngroups) |
1479 | return -EINVAL; | |
1480 | netlink_table_grab(); | |
84659eb5 JB |
1481 | netlink_update_socket_mc(nlk, val, |
1482 | optname == NETLINK_ADD_MEMBERSHIP); | |
9a4595bc | 1483 | netlink_table_ungrab(); |
03292745 PNA |
1484 | |
1485 | if (nlk->netlink_bind) | |
1486 | nlk->netlink_bind(val); | |
1487 | ||
9a4595bc PM |
1488 | err = 0; |
1489 | break; | |
1490 | } | |
be0c22a4 PNA |
1491 | case NETLINK_BROADCAST_ERROR: |
1492 | if (val) | |
1493 | nlk->flags |= NETLINK_BROADCAST_SEND_ERROR; | |
1494 | else | |
1495 | nlk->flags &= ~NETLINK_BROADCAST_SEND_ERROR; | |
1496 | err = 0; | |
1497 | break; | |
38938bfe PNA |
1498 | case NETLINK_NO_ENOBUFS: |
1499 | if (val) { | |
1500 | nlk->flags |= NETLINK_RECV_NO_ENOBUFS; | |
cd967e05 | 1501 | clear_bit(NETLINK_CONGESTED, &nlk->state); |
38938bfe | 1502 | wake_up_interruptible(&nlk->wait); |
658cb354 | 1503 | } else { |
38938bfe | 1504 | nlk->flags &= ~NETLINK_RECV_NO_ENOBUFS; |
658cb354 | 1505 | } |
38938bfe PNA |
1506 | err = 0; |
1507 | break; | |
ccdfcc39 PM |
1508 | #ifdef CONFIG_NETLINK_MMAP |
1509 | case NETLINK_RX_RING: | |
1510 | case NETLINK_TX_RING: { | |
1511 | struct nl_mmap_req req; | |
1512 | ||
1513 | /* Rings might consume more memory than queue limits, require | |
1514 | * CAP_NET_ADMIN. | |
1515 | */ | |
1516 | if (!capable(CAP_NET_ADMIN)) | |
1517 | return -EPERM; | |
1518 | if (optlen < sizeof(req)) | |
1519 | return -EINVAL; | |
1520 | if (copy_from_user(&req, optval, sizeof(req))) | |
1521 | return -EFAULT; | |
1522 | err = netlink_set_ring(sk, &req, false, | |
1523 | optname == NETLINK_TX_RING); | |
1524 | break; | |
1525 | } | |
1526 | #endif /* CONFIG_NETLINK_MMAP */ | |
9a4595bc PM |
1527 | default: |
1528 | err = -ENOPROTOOPT; | |
1529 | } | |
1530 | return err; | |
1531 | } | |
1532 | ||
1533 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
746fac4d | 1534 | char __user *optval, int __user *optlen) |
9a4595bc PM |
1535 | { |
1536 | struct sock *sk = sock->sk; | |
1537 | struct netlink_sock *nlk = nlk_sk(sk); | |
1538 | int len, val, err; | |
1539 | ||
1540 | if (level != SOL_NETLINK) | |
1541 | return -ENOPROTOOPT; | |
1542 | ||
1543 | if (get_user(len, optlen)) | |
1544 | return -EFAULT; | |
1545 | if (len < 0) | |
1546 | return -EINVAL; | |
1547 | ||
1548 | switch (optname) { | |
1549 | case NETLINK_PKTINFO: | |
1550 | if (len < sizeof(int)) | |
1551 | return -EINVAL; | |
1552 | len = sizeof(int); | |
1553 | val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0; | |
a27b58fe HC |
1554 | if (put_user(len, optlen) || |
1555 | put_user(val, optval)) | |
1556 | return -EFAULT; | |
9a4595bc PM |
1557 | err = 0; |
1558 | break; | |
be0c22a4 PNA |
1559 | case NETLINK_BROADCAST_ERROR: |
1560 | if (len < sizeof(int)) | |
1561 | return -EINVAL; | |
1562 | len = sizeof(int); | |
1563 | val = nlk->flags & NETLINK_BROADCAST_SEND_ERROR ? 1 : 0; | |
1564 | if (put_user(len, optlen) || | |
1565 | put_user(val, optval)) | |
1566 | return -EFAULT; | |
1567 | err = 0; | |
1568 | break; | |
38938bfe PNA |
1569 | case NETLINK_NO_ENOBUFS: |
1570 | if (len < sizeof(int)) | |
1571 | return -EINVAL; | |
1572 | len = sizeof(int); | |
1573 | val = nlk->flags & NETLINK_RECV_NO_ENOBUFS ? 1 : 0; | |
1574 | if (put_user(len, optlen) || | |
1575 | put_user(val, optval)) | |
1576 | return -EFAULT; | |
1577 | err = 0; | |
1578 | break; | |
9a4595bc PM |
1579 | default: |
1580 | err = -ENOPROTOOPT; | |
1581 | } | |
1582 | return err; | |
1583 | } | |
1584 | ||
1585 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
1586 | { | |
1587 | struct nl_pktinfo info; | |
1588 | ||
1589 | info.group = NETLINK_CB(skb).dst_group; | |
1590 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
1591 | } | |
1592 | ||
1da177e4 LT |
1593 | static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, |
1594 | struct msghdr *msg, size_t len) | |
1595 | { | |
1596 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1597 | struct sock *sk = sock->sk; | |
1598 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 1599 | struct sockaddr_nl *addr = msg->msg_name; |
15e47304 | 1600 | u32 dst_portid; |
d629b836 | 1601 | u32 dst_group; |
1da177e4 LT |
1602 | struct sk_buff *skb; |
1603 | int err; | |
1604 | struct scm_cookie scm; | |
1605 | ||
1606 | if (msg->msg_flags&MSG_OOB) | |
1607 | return -EOPNOTSUPP; | |
1608 | ||
16e57262 | 1609 | if (NULL == siocb->scm) |
1da177e4 | 1610 | siocb->scm = &scm; |
16e57262 | 1611 | |
e0e3cea4 | 1612 | err = scm_send(sock, msg, siocb->scm, true); |
1da177e4 LT |
1613 | if (err < 0) |
1614 | return err; | |
1615 | ||
1616 | if (msg->msg_namelen) { | |
b47030c7 | 1617 | err = -EINVAL; |
1da177e4 | 1618 | if (addr->nl_family != AF_NETLINK) |
b47030c7 | 1619 | goto out; |
15e47304 | 1620 | dst_portid = addr->nl_pid; |
d629b836 | 1621 | dst_group = ffs(addr->nl_groups); |
b47030c7 | 1622 | err = -EPERM; |
15e47304 | 1623 | if ((dst_group || dst_portid) && |
9785e10a | 1624 | !netlink_capable(sock, NL_CFG_F_NONROOT_SEND)) |
b47030c7 | 1625 | goto out; |
1da177e4 | 1626 | } else { |
15e47304 | 1627 | dst_portid = nlk->dst_portid; |
d629b836 | 1628 | dst_group = nlk->dst_group; |
1da177e4 LT |
1629 | } |
1630 | ||
15e47304 | 1631 | if (!nlk->portid) { |
1da177e4 LT |
1632 | err = netlink_autobind(sock); |
1633 | if (err) | |
1634 | goto out; | |
1635 | } | |
1636 | ||
1637 | err = -EMSGSIZE; | |
1638 | if (len > sk->sk_sndbuf - 32) | |
1639 | goto out; | |
1640 | err = -ENOBUFS; | |
339bf98f | 1641 | skb = alloc_skb(len, GFP_KERNEL); |
6ac552fd | 1642 | if (skb == NULL) |
1da177e4 LT |
1643 | goto out; |
1644 | ||
15e47304 | 1645 | NETLINK_CB(skb).portid = nlk->portid; |
d629b836 | 1646 | NETLINK_CB(skb).dst_group = dst_group; |
dbe9a417 | 1647 | NETLINK_CB(skb).creds = siocb->scm->creds; |
1da177e4 | 1648 | |
1da177e4 | 1649 | err = -EFAULT; |
6ac552fd | 1650 | if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) { |
1da177e4 LT |
1651 | kfree_skb(skb); |
1652 | goto out; | |
1653 | } | |
1654 | ||
1655 | err = security_netlink_send(sk, skb); | |
1656 | if (err) { | |
1657 | kfree_skb(skb); | |
1658 | goto out; | |
1659 | } | |
1660 | ||
d629b836 | 1661 | if (dst_group) { |
1da177e4 | 1662 | atomic_inc(&skb->users); |
15e47304 | 1663 | netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL); |
1da177e4 | 1664 | } |
15e47304 | 1665 | err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags&MSG_DONTWAIT); |
1da177e4 LT |
1666 | |
1667 | out: | |
b47030c7 | 1668 | scm_destroy(siocb->scm); |
1da177e4 LT |
1669 | return err; |
1670 | } | |
1671 | ||
1672 | static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, | |
1673 | struct msghdr *msg, size_t len, | |
1674 | int flags) | |
1675 | { | |
1676 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1677 | struct scm_cookie scm; | |
1678 | struct sock *sk = sock->sk; | |
1679 | struct netlink_sock *nlk = nlk_sk(sk); | |
1680 | int noblock = flags&MSG_DONTWAIT; | |
1681 | size_t copied; | |
68d6ac6d | 1682 | struct sk_buff *skb, *data_skb; |
b44d211e | 1683 | int err, ret; |
1da177e4 LT |
1684 | |
1685 | if (flags&MSG_OOB) | |
1686 | return -EOPNOTSUPP; | |
1687 | ||
1688 | copied = 0; | |
1689 | ||
6ac552fd PM |
1690 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
1691 | if (skb == NULL) | |
1da177e4 LT |
1692 | goto out; |
1693 | ||
68d6ac6d JB |
1694 | data_skb = skb; |
1695 | ||
1dacc76d JB |
1696 | #ifdef CONFIG_COMPAT_NETLINK_MESSAGES |
1697 | if (unlikely(skb_shinfo(skb)->frag_list)) { | |
1dacc76d | 1698 | /* |
68d6ac6d JB |
1699 | * If this skb has a frag_list, then here that means that we |
1700 | * will have to use the frag_list skb's data for compat tasks | |
1701 | * and the regular skb's data for normal (non-compat) tasks. | |
1dacc76d | 1702 | * |
68d6ac6d JB |
1703 | * If we need to send the compat skb, assign it to the |
1704 | * 'data_skb' variable so that it will be used below for data | |
1705 | * copying. We keep 'skb' for everything else, including | |
1706 | * freeing both later. | |
1dacc76d | 1707 | */ |
68d6ac6d JB |
1708 | if (flags & MSG_CMSG_COMPAT) |
1709 | data_skb = skb_shinfo(skb)->frag_list; | |
1dacc76d JB |
1710 | } |
1711 | #endif | |
1712 | ||
1da177e4 LT |
1713 | msg->msg_namelen = 0; |
1714 | ||
68d6ac6d | 1715 | copied = data_skb->len; |
1da177e4 LT |
1716 | if (len < copied) { |
1717 | msg->msg_flags |= MSG_TRUNC; | |
1718 | copied = len; | |
1719 | } | |
1720 | ||
68d6ac6d JB |
1721 | skb_reset_transport_header(data_skb); |
1722 | err = skb_copy_datagram_iovec(data_skb, 0, msg->msg_iov, copied); | |
1da177e4 LT |
1723 | |
1724 | if (msg->msg_name) { | |
6ac552fd | 1725 | struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name; |
1da177e4 LT |
1726 | addr->nl_family = AF_NETLINK; |
1727 | addr->nl_pad = 0; | |
15e47304 | 1728 | addr->nl_pid = NETLINK_CB(skb).portid; |
d629b836 | 1729 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
1730 | msg->msg_namelen = sizeof(*addr); |
1731 | } | |
1732 | ||
cc9a06cd PM |
1733 | if (nlk->flags & NETLINK_RECV_PKTINFO) |
1734 | netlink_cmsg_recv_pktinfo(msg, skb); | |
1735 | ||
1da177e4 LT |
1736 | if (NULL == siocb->scm) { |
1737 | memset(&scm, 0, sizeof(scm)); | |
1738 | siocb->scm = &scm; | |
1739 | } | |
1740 | siocb->scm->creds = *NETLINK_CREDS(skb); | |
188ccb55 | 1741 | if (flags & MSG_TRUNC) |
68d6ac6d | 1742 | copied = data_skb->len; |
daa3766e | 1743 | |
1da177e4 LT |
1744 | skb_free_datagram(sk, skb); |
1745 | ||
b44d211e AV |
1746 | if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) { |
1747 | ret = netlink_dump(sk); | |
1748 | if (ret) { | |
1749 | sk->sk_err = ret; | |
1750 | sk->sk_error_report(sk); | |
1751 | } | |
1752 | } | |
1da177e4 LT |
1753 | |
1754 | scm_recv(sock, msg, siocb->scm, flags); | |
1da177e4 LT |
1755 | out: |
1756 | netlink_rcv_wake(sk); | |
1757 | return err ? : copied; | |
1758 | } | |
1759 | ||
1760 | static void netlink_data_ready(struct sock *sk, int len) | |
1761 | { | |
cd40b7d3 | 1762 | BUG(); |
1da177e4 LT |
1763 | } |
1764 | ||
1765 | /* | |
746fac4d | 1766 | * We export these functions to other modules. They provide a |
1da177e4 LT |
1767 | * complete set of kernel non-blocking support for message |
1768 | * queueing. | |
1769 | */ | |
1770 | ||
1771 | struct sock * | |
9f00d977 PNA |
1772 | __netlink_kernel_create(struct net *net, int unit, struct module *module, |
1773 | struct netlink_kernel_cfg *cfg) | |
1da177e4 LT |
1774 | { |
1775 | struct socket *sock; | |
1776 | struct sock *sk; | |
77247bbb | 1777 | struct netlink_sock *nlk; |
5c398dc8 | 1778 | struct listeners *listeners = NULL; |
a31f2d17 PNA |
1779 | struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL; |
1780 | unsigned int groups; | |
1da177e4 | 1781 | |
fab2caf6 | 1782 | BUG_ON(!nl_table); |
1da177e4 | 1783 | |
6ac552fd | 1784 | if (unit < 0 || unit >= MAX_LINKS) |
1da177e4 LT |
1785 | return NULL; |
1786 | ||
1787 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
1788 | return NULL; | |
1789 | ||
23fe1866 PE |
1790 | /* |
1791 | * We have to just have a reference on the net from sk, but don't | |
1792 | * get_net it. Besides, we cannot get and then put the net here. | |
1793 | * So we create one inside init_net and the move it to net. | |
1794 | */ | |
1795 | ||
1796 | if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0) | |
1797 | goto out_sock_release_nosk; | |
1798 | ||
1799 | sk = sock->sk; | |
edf02087 | 1800 | sk_change_net(sk, net); |
4fdb3bb7 | 1801 | |
a31f2d17 | 1802 | if (!cfg || cfg->groups < 32) |
4277a083 | 1803 | groups = 32; |
a31f2d17 PNA |
1804 | else |
1805 | groups = cfg->groups; | |
4277a083 | 1806 | |
5c398dc8 | 1807 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
4277a083 PM |
1808 | if (!listeners) |
1809 | goto out_sock_release; | |
1810 | ||
1da177e4 | 1811 | sk->sk_data_ready = netlink_data_ready; |
a31f2d17 PNA |
1812 | if (cfg && cfg->input) |
1813 | nlk_sk(sk)->netlink_rcv = cfg->input; | |
1da177e4 | 1814 | |
b4b51029 | 1815 | if (netlink_insert(sk, net, 0)) |
77247bbb | 1816 | goto out_sock_release; |
4fdb3bb7 | 1817 | |
77247bbb PM |
1818 | nlk = nlk_sk(sk); |
1819 | nlk->flags |= NETLINK_KERNEL_SOCKET; | |
4fdb3bb7 | 1820 | |
4fdb3bb7 | 1821 | netlink_table_grab(); |
b4b51029 EB |
1822 | if (!nl_table[unit].registered) { |
1823 | nl_table[unit].groups = groups; | |
5c398dc8 | 1824 | rcu_assign_pointer(nl_table[unit].listeners, listeners); |
b4b51029 EB |
1825 | nl_table[unit].cb_mutex = cb_mutex; |
1826 | nl_table[unit].module = module; | |
9785e10a PNA |
1827 | if (cfg) { |
1828 | nl_table[unit].bind = cfg->bind; | |
1829 | nl_table[unit].flags = cfg->flags; | |
1830 | } | |
b4b51029 | 1831 | nl_table[unit].registered = 1; |
f937f1f4 JJ |
1832 | } else { |
1833 | kfree(listeners); | |
869e58f8 | 1834 | nl_table[unit].registered++; |
b4b51029 | 1835 | } |
4fdb3bb7 | 1836 | netlink_table_ungrab(); |
77247bbb PM |
1837 | return sk; |
1838 | ||
4fdb3bb7 | 1839 | out_sock_release: |
4277a083 | 1840 | kfree(listeners); |
9dfbec1f | 1841 | netlink_kernel_release(sk); |
23fe1866 PE |
1842 | return NULL; |
1843 | ||
1844 | out_sock_release_nosk: | |
4fdb3bb7 | 1845 | sock_release(sock); |
77247bbb | 1846 | return NULL; |
1da177e4 | 1847 | } |
9f00d977 | 1848 | EXPORT_SYMBOL(__netlink_kernel_create); |
b7c6ba6e DL |
1849 | |
1850 | void | |
1851 | netlink_kernel_release(struct sock *sk) | |
1852 | { | |
edf02087 | 1853 | sk_release_kernel(sk); |
b7c6ba6e DL |
1854 | } |
1855 | EXPORT_SYMBOL(netlink_kernel_release); | |
1856 | ||
d136f1bd | 1857 | int __netlink_change_ngroups(struct sock *sk, unsigned int groups) |
b4ff4f04 | 1858 | { |
5c398dc8 | 1859 | struct listeners *new, *old; |
b4ff4f04 | 1860 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; |
b4ff4f04 JB |
1861 | |
1862 | if (groups < 32) | |
1863 | groups = 32; | |
1864 | ||
b4ff4f04 | 1865 | if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { |
5c398dc8 ED |
1866 | new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC); |
1867 | if (!new) | |
d136f1bd | 1868 | return -ENOMEM; |
6d772ac5 | 1869 | old = nl_deref_protected(tbl->listeners); |
5c398dc8 ED |
1870 | memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups)); |
1871 | rcu_assign_pointer(tbl->listeners, new); | |
1872 | ||
37b6b935 | 1873 | kfree_rcu(old, rcu); |
b4ff4f04 JB |
1874 | } |
1875 | tbl->groups = groups; | |
1876 | ||
d136f1bd JB |
1877 | return 0; |
1878 | } | |
1879 | ||
1880 | /** | |
1881 | * netlink_change_ngroups - change number of multicast groups | |
1882 | * | |
1883 | * This changes the number of multicast groups that are available | |
1884 | * on a certain netlink family. Note that it is not possible to | |
1885 | * change the number of groups to below 32. Also note that it does | |
1886 | * not implicitly call netlink_clear_multicast_users() when the | |
1887 | * number of groups is reduced. | |
1888 | * | |
1889 | * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). | |
1890 | * @groups: The new number of groups. | |
1891 | */ | |
1892 | int netlink_change_ngroups(struct sock *sk, unsigned int groups) | |
1893 | { | |
1894 | int err; | |
1895 | ||
1896 | netlink_table_grab(); | |
1897 | err = __netlink_change_ngroups(sk, groups); | |
b4ff4f04 | 1898 | netlink_table_ungrab(); |
d136f1bd | 1899 | |
b4ff4f04 JB |
1900 | return err; |
1901 | } | |
b4ff4f04 | 1902 | |
b8273570 JB |
1903 | void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group) |
1904 | { | |
1905 | struct sock *sk; | |
b8273570 JB |
1906 | struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; |
1907 | ||
b67bfe0d | 1908 | sk_for_each_bound(sk, &tbl->mc_list) |
b8273570 JB |
1909 | netlink_update_socket_mc(nlk_sk(sk), group, 0); |
1910 | } | |
1911 | ||
84659eb5 JB |
1912 | /** |
1913 | * netlink_clear_multicast_users - kick off multicast listeners | |
1914 | * | |
1915 | * This function removes all listeners from the given group. | |
1916 | * @ksk: The kernel netlink socket, as returned by | |
1917 | * netlink_kernel_create(). | |
1918 | * @group: The multicast group to clear. | |
1919 | */ | |
1920 | void netlink_clear_multicast_users(struct sock *ksk, unsigned int group) | |
1921 | { | |
84659eb5 | 1922 | netlink_table_grab(); |
b8273570 | 1923 | __netlink_clear_multicast_users(ksk, group); |
84659eb5 JB |
1924 | netlink_table_ungrab(); |
1925 | } | |
84659eb5 | 1926 | |
a46621a3 | 1927 | struct nlmsghdr * |
15e47304 | 1928 | __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags) |
a46621a3 DV |
1929 | { |
1930 | struct nlmsghdr *nlh; | |
573ce260 | 1931 | int size = nlmsg_msg_size(len); |
a46621a3 DV |
1932 | |
1933 | nlh = (struct nlmsghdr*)skb_put(skb, NLMSG_ALIGN(size)); | |
1934 | nlh->nlmsg_type = type; | |
1935 | nlh->nlmsg_len = size; | |
1936 | nlh->nlmsg_flags = flags; | |
15e47304 | 1937 | nlh->nlmsg_pid = portid; |
a46621a3 DV |
1938 | nlh->nlmsg_seq = seq; |
1939 | if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0) | |
573ce260 | 1940 | memset(nlmsg_data(nlh) + len, 0, NLMSG_ALIGN(size) - size); |
a46621a3 DV |
1941 | return nlh; |
1942 | } | |
1943 | EXPORT_SYMBOL(__nlmsg_put); | |
1944 | ||
1da177e4 LT |
1945 | /* |
1946 | * It looks a bit ugly. | |
1947 | * It would be better to create kernel thread. | |
1948 | */ | |
1949 | ||
1950 | static int netlink_dump(struct sock *sk) | |
1951 | { | |
1952 | struct netlink_sock *nlk = nlk_sk(sk); | |
1953 | struct netlink_callback *cb; | |
c7ac8679 | 1954 | struct sk_buff *skb = NULL; |
1da177e4 | 1955 | struct nlmsghdr *nlh; |
bf8b79e4 | 1956 | int len, err = -ENOBUFS; |
c7ac8679 | 1957 | int alloc_size; |
1da177e4 | 1958 | |
af65bdfc | 1959 | mutex_lock(nlk->cb_mutex); |
1da177e4 LT |
1960 | |
1961 | cb = nlk->cb; | |
1962 | if (cb == NULL) { | |
bf8b79e4 TG |
1963 | err = -EINVAL; |
1964 | goto errout_skb; | |
1da177e4 LT |
1965 | } |
1966 | ||
c7ac8679 GR |
1967 | alloc_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE); |
1968 | ||
1969 | skb = sock_rmalloc(sk, alloc_size, 0, GFP_KERNEL); | |
1970 | if (!skb) | |
c63d6ea3 | 1971 | goto errout_skb; |
c7ac8679 | 1972 | |
1da177e4 LT |
1973 | len = cb->dump(skb, cb); |
1974 | ||
1975 | if (len > 0) { | |
af65bdfc | 1976 | mutex_unlock(nlk->cb_mutex); |
b1153f29 SH |
1977 | |
1978 | if (sk_filter(sk, skb)) | |
1979 | kfree_skb(skb); | |
4a7e7c2a ED |
1980 | else |
1981 | __netlink_sendskb(sk, skb); | |
1da177e4 LT |
1982 | return 0; |
1983 | } | |
1984 | ||
bf8b79e4 TG |
1985 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); |
1986 | if (!nlh) | |
1987 | goto errout_skb; | |
1988 | ||
670dc283 JB |
1989 | nl_dump_check_consistent(cb, nlh); |
1990 | ||
bf8b79e4 TG |
1991 | memcpy(nlmsg_data(nlh), &len, sizeof(len)); |
1992 | ||
b1153f29 SH |
1993 | if (sk_filter(sk, skb)) |
1994 | kfree_skb(skb); | |
4a7e7c2a ED |
1995 | else |
1996 | __netlink_sendskb(sk, skb); | |
1da177e4 | 1997 | |
a8f74b22 TG |
1998 | if (cb->done) |
1999 | cb->done(cb); | |
1da177e4 | 2000 | nlk->cb = NULL; |
af65bdfc | 2001 | mutex_unlock(nlk->cb_mutex); |
1da177e4 | 2002 | |
6dc878a8 | 2003 | module_put(cb->module); |
bfb253c9 | 2004 | netlink_consume_callback(cb); |
1da177e4 | 2005 | return 0; |
1797754e | 2006 | |
bf8b79e4 | 2007 | errout_skb: |
af65bdfc | 2008 | mutex_unlock(nlk->cb_mutex); |
bf8b79e4 | 2009 | kfree_skb(skb); |
bf8b79e4 | 2010 | return err; |
1da177e4 LT |
2011 | } |
2012 | ||
6dc878a8 G |
2013 | int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, |
2014 | const struct nlmsghdr *nlh, | |
2015 | struct netlink_dump_control *control) | |
1da177e4 LT |
2016 | { |
2017 | struct netlink_callback *cb; | |
2018 | struct sock *sk; | |
2019 | struct netlink_sock *nlk; | |
b44d211e | 2020 | int ret; |
1da177e4 | 2021 | |
0da974f4 | 2022 | cb = kzalloc(sizeof(*cb), GFP_KERNEL); |
1da177e4 LT |
2023 | if (cb == NULL) |
2024 | return -ENOBUFS; | |
2025 | ||
80d326fa PNA |
2026 | cb->dump = control->dump; |
2027 | cb->done = control->done; | |
1da177e4 | 2028 | cb->nlh = nlh; |
7175c883 | 2029 | cb->data = control->data; |
6dc878a8 | 2030 | cb->module = control->module; |
80d326fa | 2031 | cb->min_dump_alloc = control->min_dump_alloc; |
1da177e4 LT |
2032 | atomic_inc(&skb->users); |
2033 | cb->skb = skb; | |
2034 | ||
15e47304 | 2035 | sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).portid); |
1da177e4 LT |
2036 | if (sk == NULL) { |
2037 | netlink_destroy_callback(cb); | |
2038 | return -ECONNREFUSED; | |
2039 | } | |
2040 | nlk = nlk_sk(sk); | |
6dc878a8 | 2041 | |
af65bdfc | 2042 | mutex_lock(nlk->cb_mutex); |
6dc878a8 | 2043 | /* A dump is in progress... */ |
3f660d66 | 2044 | if (nlk->cb) { |
af65bdfc | 2045 | mutex_unlock(nlk->cb_mutex); |
1da177e4 | 2046 | netlink_destroy_callback(cb); |
6dc878a8 G |
2047 | ret = -EBUSY; |
2048 | goto out; | |
1da177e4 | 2049 | } |
6dc878a8 G |
2050 | /* add reference of module which cb->dump belongs to */ |
2051 | if (!try_module_get(cb->module)) { | |
2052 | mutex_unlock(nlk->cb_mutex); | |
2053 | netlink_destroy_callback(cb); | |
2054 | ret = -EPROTONOSUPPORT; | |
2055 | goto out; | |
2056 | } | |
2057 | ||
1da177e4 | 2058 | nlk->cb = cb; |
af65bdfc | 2059 | mutex_unlock(nlk->cb_mutex); |
1da177e4 | 2060 | |
b44d211e | 2061 | ret = netlink_dump(sk); |
6dc878a8 | 2062 | out: |
1da177e4 | 2063 | sock_put(sk); |
5c58298c | 2064 | |
b44d211e AV |
2065 | if (ret) |
2066 | return ret; | |
2067 | ||
5c58298c DL |
2068 | /* We successfully started a dump, by returning -EINTR we |
2069 | * signal not to send ACK even if it was requested. | |
2070 | */ | |
2071 | return -EINTR; | |
1da177e4 | 2072 | } |
6dc878a8 | 2073 | EXPORT_SYMBOL(__netlink_dump_start); |
1da177e4 LT |
2074 | |
2075 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) | |
2076 | { | |
2077 | struct sk_buff *skb; | |
2078 | struct nlmsghdr *rep; | |
2079 | struct nlmsgerr *errmsg; | |
339bf98f | 2080 | size_t payload = sizeof(*errmsg); |
1da177e4 | 2081 | |
339bf98f TG |
2082 | /* error messages get the original request appened */ |
2083 | if (err) | |
2084 | payload += nlmsg_len(nlh); | |
1da177e4 | 2085 | |
339bf98f | 2086 | skb = nlmsg_new(payload, GFP_KERNEL); |
1da177e4 LT |
2087 | if (!skb) { |
2088 | struct sock *sk; | |
2089 | ||
3b1e0a65 | 2090 | sk = netlink_lookup(sock_net(in_skb->sk), |
b4b51029 | 2091 | in_skb->sk->sk_protocol, |
15e47304 | 2092 | NETLINK_CB(in_skb).portid); |
1da177e4 LT |
2093 | if (sk) { |
2094 | sk->sk_err = ENOBUFS; | |
2095 | sk->sk_error_report(sk); | |
2096 | sock_put(sk); | |
2097 | } | |
2098 | return; | |
2099 | } | |
2100 | ||
15e47304 | 2101 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, |
5dba93ae | 2102 | NLMSG_ERROR, payload, 0); |
bf8b79e4 | 2103 | errmsg = nlmsg_data(rep); |
1da177e4 | 2104 | errmsg->error = err; |
bf8b79e4 | 2105 | memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh)); |
15e47304 | 2106 | netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT); |
1da177e4 | 2107 | } |
6ac552fd | 2108 | EXPORT_SYMBOL(netlink_ack); |
1da177e4 | 2109 | |
cd40b7d3 | 2110 | int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
1d00a4eb | 2111 | struct nlmsghdr *)) |
82ace47a | 2112 | { |
82ace47a TG |
2113 | struct nlmsghdr *nlh; |
2114 | int err; | |
2115 | ||
2116 | while (skb->len >= nlmsg_total_size(0)) { | |
cd40b7d3 DL |
2117 | int msglen; |
2118 | ||
b529ccf2 | 2119 | nlh = nlmsg_hdr(skb); |
d35b6856 | 2120 | err = 0; |
82ace47a | 2121 | |
ad8e4b75 | 2122 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
2123 | return 0; |
2124 | ||
d35b6856 TG |
2125 | /* Only requests are handled by the kernel */ |
2126 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | |
5c58298c | 2127 | goto ack; |
45e7ae7f TG |
2128 | |
2129 | /* Skip control messages */ | |
2130 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | |
5c58298c | 2131 | goto ack; |
d35b6856 | 2132 | |
1d00a4eb | 2133 | err = cb(skb, nlh); |
5c58298c DL |
2134 | if (err == -EINTR) |
2135 | goto skip; | |
2136 | ||
2137 | ack: | |
d35b6856 | 2138 | if (nlh->nlmsg_flags & NLM_F_ACK || err) |
82ace47a | 2139 | netlink_ack(skb, nlh, err); |
82ace47a | 2140 | |
5c58298c | 2141 | skip: |
6ac552fd | 2142 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
cd40b7d3 DL |
2143 | if (msglen > skb->len) |
2144 | msglen = skb->len; | |
2145 | skb_pull(skb, msglen); | |
82ace47a TG |
2146 | } |
2147 | ||
2148 | return 0; | |
2149 | } | |
6ac552fd | 2150 | EXPORT_SYMBOL(netlink_rcv_skb); |
82ace47a | 2151 | |
d387f6ad TG |
2152 | /** |
2153 | * nlmsg_notify - send a notification netlink message | |
2154 | * @sk: netlink socket to use | |
2155 | * @skb: notification message | |
15e47304 | 2156 | * @portid: destination netlink portid for reports or 0 |
d387f6ad TG |
2157 | * @group: destination multicast group or 0 |
2158 | * @report: 1 to report back, 0 to disable | |
2159 | * @flags: allocation flags | |
2160 | */ | |
15e47304 | 2161 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, |
d387f6ad TG |
2162 | unsigned int group, int report, gfp_t flags) |
2163 | { | |
2164 | int err = 0; | |
2165 | ||
2166 | if (group) { | |
15e47304 | 2167 | int exclude_portid = 0; |
d387f6ad TG |
2168 | |
2169 | if (report) { | |
2170 | atomic_inc(&skb->users); | |
15e47304 | 2171 | exclude_portid = portid; |
d387f6ad TG |
2172 | } |
2173 | ||
1ce85fe4 PNA |
2174 | /* errors reported via destination sk->sk_err, but propagate |
2175 | * delivery errors if NETLINK_BROADCAST_ERROR flag is set */ | |
15e47304 | 2176 | err = nlmsg_multicast(sk, skb, exclude_portid, group, flags); |
d387f6ad TG |
2177 | } |
2178 | ||
1ce85fe4 PNA |
2179 | if (report) { |
2180 | int err2; | |
2181 | ||
15e47304 | 2182 | err2 = nlmsg_unicast(sk, skb, portid); |
1ce85fe4 PNA |
2183 | if (!err || err == -ESRCH) |
2184 | err = err2; | |
2185 | } | |
d387f6ad TG |
2186 | |
2187 | return err; | |
2188 | } | |
6ac552fd | 2189 | EXPORT_SYMBOL(nlmsg_notify); |
d387f6ad | 2190 | |
1da177e4 LT |
2191 | #ifdef CONFIG_PROC_FS |
2192 | struct nl_seq_iter { | |
e372c414 | 2193 | struct seq_net_private p; |
1da177e4 LT |
2194 | int link; |
2195 | int hash_idx; | |
2196 | }; | |
2197 | ||
2198 | static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) | |
2199 | { | |
2200 | struct nl_seq_iter *iter = seq->private; | |
2201 | int i, j; | |
2202 | struct sock *s; | |
1da177e4 LT |
2203 | loff_t off = 0; |
2204 | ||
6ac552fd | 2205 | for (i = 0; i < MAX_LINKS; i++) { |
15e47304 | 2206 | struct nl_portid_hash *hash = &nl_table[i].hash; |
1da177e4 LT |
2207 | |
2208 | for (j = 0; j <= hash->mask; j++) { | |
b67bfe0d | 2209 | sk_for_each(s, &hash->table[j]) { |
1218854a | 2210 | if (sock_net(s) != seq_file_net(seq)) |
b4b51029 | 2211 | continue; |
1da177e4 LT |
2212 | if (off == pos) { |
2213 | iter->link = i; | |
2214 | iter->hash_idx = j; | |
2215 | return s; | |
2216 | } | |
2217 | ++off; | |
2218 | } | |
2219 | } | |
2220 | } | |
2221 | return NULL; | |
2222 | } | |
2223 | ||
2224 | static void *netlink_seq_start(struct seq_file *seq, loff_t *pos) | |
9a429c49 | 2225 | __acquires(nl_table_lock) |
1da177e4 LT |
2226 | { |
2227 | read_lock(&nl_table_lock); | |
2228 | return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
2229 | } | |
2230 | ||
2231 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2232 | { | |
2233 | struct sock *s; | |
2234 | struct nl_seq_iter *iter; | |
2235 | int i, j; | |
2236 | ||
2237 | ++*pos; | |
2238 | ||
2239 | if (v == SEQ_START_TOKEN) | |
2240 | return netlink_seq_socket_idx(seq, 0); | |
746fac4d | 2241 | |
b4b51029 EB |
2242 | iter = seq->private; |
2243 | s = v; | |
2244 | do { | |
2245 | s = sk_next(s); | |
1218854a | 2246 | } while (s && sock_net(s) != seq_file_net(seq)); |
1da177e4 LT |
2247 | if (s) |
2248 | return s; | |
2249 | ||
1da177e4 LT |
2250 | i = iter->link; |
2251 | j = iter->hash_idx + 1; | |
2252 | ||
2253 | do { | |
15e47304 | 2254 | struct nl_portid_hash *hash = &nl_table[i].hash; |
1da177e4 LT |
2255 | |
2256 | for (; j <= hash->mask; j++) { | |
2257 | s = sk_head(&hash->table[j]); | |
1218854a | 2258 | while (s && sock_net(s) != seq_file_net(seq)) |
b4b51029 | 2259 | s = sk_next(s); |
1da177e4 LT |
2260 | if (s) { |
2261 | iter->link = i; | |
2262 | iter->hash_idx = j; | |
2263 | return s; | |
2264 | } | |
2265 | } | |
2266 | ||
2267 | j = 0; | |
2268 | } while (++i < MAX_LINKS); | |
2269 | ||
2270 | return NULL; | |
2271 | } | |
2272 | ||
2273 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
9a429c49 | 2274 | __releases(nl_table_lock) |
1da177e4 LT |
2275 | { |
2276 | read_unlock(&nl_table_lock); | |
2277 | } | |
2278 | ||
2279 | ||
2280 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
2281 | { | |
658cb354 | 2282 | if (v == SEQ_START_TOKEN) { |
1da177e4 LT |
2283 | seq_puts(seq, |
2284 | "sk Eth Pid Groups " | |
cf0aa4e0 | 2285 | "Rmem Wmem Dump Locks Drops Inode\n"); |
658cb354 | 2286 | } else { |
1da177e4 LT |
2287 | struct sock *s = v; |
2288 | struct netlink_sock *nlk = nlk_sk(s); | |
2289 | ||
9f1e0ad0 | 2290 | seq_printf(seq, "%pK %-3d %-6u %08x %-8d %-8d %pK %-8d %-8d %-8lu\n", |
1da177e4 LT |
2291 | s, |
2292 | s->sk_protocol, | |
15e47304 | 2293 | nlk->portid, |
513c2500 | 2294 | nlk->groups ? (u32)nlk->groups[0] : 0, |
31e6d363 ED |
2295 | sk_rmem_alloc_get(s), |
2296 | sk_wmem_alloc_get(s), | |
1da177e4 | 2297 | nlk->cb, |
38938bfe | 2298 | atomic_read(&s->sk_refcnt), |
cf0aa4e0 MY |
2299 | atomic_read(&s->sk_drops), |
2300 | sock_i_ino(s) | |
1da177e4 LT |
2301 | ); |
2302 | ||
2303 | } | |
2304 | return 0; | |
2305 | } | |
2306 | ||
56b3d975 | 2307 | static const struct seq_operations netlink_seq_ops = { |
1da177e4 LT |
2308 | .start = netlink_seq_start, |
2309 | .next = netlink_seq_next, | |
2310 | .stop = netlink_seq_stop, | |
2311 | .show = netlink_seq_show, | |
2312 | }; | |
2313 | ||
2314 | ||
2315 | static int netlink_seq_open(struct inode *inode, struct file *file) | |
2316 | { | |
e372c414 DL |
2317 | return seq_open_net(inode, file, &netlink_seq_ops, |
2318 | sizeof(struct nl_seq_iter)); | |
b4b51029 EB |
2319 | } |
2320 | ||
da7071d7 | 2321 | static const struct file_operations netlink_seq_fops = { |
1da177e4 LT |
2322 | .owner = THIS_MODULE, |
2323 | .open = netlink_seq_open, | |
2324 | .read = seq_read, | |
2325 | .llseek = seq_lseek, | |
e372c414 | 2326 | .release = seq_release_net, |
1da177e4 LT |
2327 | }; |
2328 | ||
2329 | #endif | |
2330 | ||
2331 | int netlink_register_notifier(struct notifier_block *nb) | |
2332 | { | |
e041c683 | 2333 | return atomic_notifier_chain_register(&netlink_chain, nb); |
1da177e4 | 2334 | } |
6ac552fd | 2335 | EXPORT_SYMBOL(netlink_register_notifier); |
1da177e4 LT |
2336 | |
2337 | int netlink_unregister_notifier(struct notifier_block *nb) | |
2338 | { | |
e041c683 | 2339 | return atomic_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 | 2340 | } |
6ac552fd | 2341 | EXPORT_SYMBOL(netlink_unregister_notifier); |
746fac4d | 2342 | |
90ddc4f0 | 2343 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
2344 | .family = PF_NETLINK, |
2345 | .owner = THIS_MODULE, | |
2346 | .release = netlink_release, | |
2347 | .bind = netlink_bind, | |
2348 | .connect = netlink_connect, | |
2349 | .socketpair = sock_no_socketpair, | |
2350 | .accept = sock_no_accept, | |
2351 | .getname = netlink_getname, | |
2352 | .poll = datagram_poll, | |
2353 | .ioctl = sock_no_ioctl, | |
2354 | .listen = sock_no_listen, | |
2355 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
2356 | .setsockopt = netlink_setsockopt, |
2357 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
2358 | .sendmsg = netlink_sendmsg, |
2359 | .recvmsg = netlink_recvmsg, | |
ccdfcc39 | 2360 | .mmap = netlink_mmap, |
1da177e4 LT |
2361 | .sendpage = sock_no_sendpage, |
2362 | }; | |
2363 | ||
ec1b4cf7 | 2364 | static const struct net_proto_family netlink_family_ops = { |
1da177e4 LT |
2365 | .family = PF_NETLINK, |
2366 | .create = netlink_create, | |
2367 | .owner = THIS_MODULE, /* for consistency 8) */ | |
2368 | }; | |
2369 | ||
4665079c | 2370 | static int __net_init netlink_net_init(struct net *net) |
b4b51029 EB |
2371 | { |
2372 | #ifdef CONFIG_PROC_FS | |
d4beaa66 | 2373 | if (!proc_create("netlink", 0, net->proc_net, &netlink_seq_fops)) |
b4b51029 EB |
2374 | return -ENOMEM; |
2375 | #endif | |
2376 | return 0; | |
2377 | } | |
2378 | ||
4665079c | 2379 | static void __net_exit netlink_net_exit(struct net *net) |
b4b51029 EB |
2380 | { |
2381 | #ifdef CONFIG_PROC_FS | |
ece31ffd | 2382 | remove_proc_entry("netlink", net->proc_net); |
b4b51029 EB |
2383 | #endif |
2384 | } | |
2385 | ||
b963ea89 DM |
2386 | static void __init netlink_add_usersock_entry(void) |
2387 | { | |
5c398dc8 | 2388 | struct listeners *listeners; |
b963ea89 DM |
2389 | int groups = 32; |
2390 | ||
5c398dc8 | 2391 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
b963ea89 | 2392 | if (!listeners) |
5c398dc8 | 2393 | panic("netlink_add_usersock_entry: Cannot allocate listeners\n"); |
b963ea89 DM |
2394 | |
2395 | netlink_table_grab(); | |
2396 | ||
2397 | nl_table[NETLINK_USERSOCK].groups = groups; | |
5c398dc8 | 2398 | rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners); |
b963ea89 DM |
2399 | nl_table[NETLINK_USERSOCK].module = THIS_MODULE; |
2400 | nl_table[NETLINK_USERSOCK].registered = 1; | |
9785e10a | 2401 | nl_table[NETLINK_USERSOCK].flags = NL_CFG_F_NONROOT_SEND; |
b963ea89 DM |
2402 | |
2403 | netlink_table_ungrab(); | |
2404 | } | |
2405 | ||
022cbae6 | 2406 | static struct pernet_operations __net_initdata netlink_net_ops = { |
b4b51029 EB |
2407 | .init = netlink_net_init, |
2408 | .exit = netlink_net_exit, | |
2409 | }; | |
2410 | ||
1da177e4 LT |
2411 | static int __init netlink_proto_init(void) |
2412 | { | |
1da177e4 | 2413 | int i; |
26ff5ddc | 2414 | unsigned long limit; |
1da177e4 LT |
2415 | unsigned int order; |
2416 | int err = proto_register(&netlink_proto, 0); | |
2417 | ||
2418 | if (err != 0) | |
2419 | goto out; | |
2420 | ||
fab25745 | 2421 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb)); |
1da177e4 | 2422 | |
0da974f4 | 2423 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
2424 | if (!nl_table) |
2425 | goto panic; | |
1da177e4 | 2426 | |
4481374c JB |
2427 | if (totalram_pages >= (128 * 1024)) |
2428 | limit = totalram_pages >> (21 - PAGE_SHIFT); | |
1da177e4 | 2429 | else |
4481374c | 2430 | limit = totalram_pages >> (23 - PAGE_SHIFT); |
1da177e4 | 2431 | |
26ff5ddc DC |
2432 | order = get_bitmask_order(limit) - 1 + PAGE_SHIFT; |
2433 | limit = (1UL << order) / sizeof(struct hlist_head); | |
2434 | order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1; | |
1da177e4 LT |
2435 | |
2436 | for (i = 0; i < MAX_LINKS; i++) { | |
15e47304 | 2437 | struct nl_portid_hash *hash = &nl_table[i].hash; |
1da177e4 | 2438 | |
15e47304 | 2439 | hash->table = nl_portid_hash_zalloc(1 * sizeof(*hash->table)); |
1da177e4 LT |
2440 | if (!hash->table) { |
2441 | while (i-- > 0) | |
15e47304 | 2442 | nl_portid_hash_free(nl_table[i].hash.table, |
1da177e4 LT |
2443 | 1 * sizeof(*hash->table)); |
2444 | kfree(nl_table); | |
fab2caf6 | 2445 | goto panic; |
1da177e4 | 2446 | } |
1da177e4 LT |
2447 | hash->max_shift = order; |
2448 | hash->shift = 0; | |
2449 | hash->mask = 0; | |
2450 | hash->rehash_time = jiffies; | |
2451 | } | |
2452 | ||
b963ea89 DM |
2453 | netlink_add_usersock_entry(); |
2454 | ||
1da177e4 | 2455 | sock_register(&netlink_family_ops); |
b4b51029 | 2456 | register_pernet_subsys(&netlink_net_ops); |
746fac4d | 2457 | /* The netlink device handler may be needed early. */ |
1da177e4 LT |
2458 | rtnetlink_init(); |
2459 | out: | |
2460 | return err; | |
fab2caf6 AM |
2461 | panic: |
2462 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
2463 | } |
2464 | ||
1da177e4 | 2465 | core_initcall(netlink_proto_init); |