Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * NETLINK Kernel-user communication protocol. | |
3 | * | |
113aa838 | 4 | * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk> |
1da177e4 | 5 | * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> |
cd1df525 | 6 | * Patrick McHardy <kaber@trash.net> |
1da177e4 LT |
7 | * |
8 | * This program is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU General Public License | |
10 | * as published by the Free Software Foundation; either version | |
11 | * 2 of the License, or (at your option) any later version. | |
746fac4d | 12 | * |
1da177e4 LT |
13 | * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith |
14 | * added netlink_proto_exit | |
15 | * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br> | |
16 | * use nlk_sk, as sk->protinfo is on a diet 8) | |
4fdb3bb7 HW |
17 | * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org> |
18 | * - inc module use count of module that owns | |
19 | * the kernel socket in case userspace opens | |
20 | * socket of same protocol | |
21 | * - remove all module support, since netlink is | |
22 | * mandatory if CONFIG_NET=y these days | |
1da177e4 LT |
23 | */ |
24 | ||
1da177e4 LT |
25 | #include <linux/module.h> |
26 | ||
4fc268d2 | 27 | #include <linux/capability.h> |
1da177e4 LT |
28 | #include <linux/kernel.h> |
29 | #include <linux/init.h> | |
1da177e4 LT |
30 | #include <linux/signal.h> |
31 | #include <linux/sched.h> | |
32 | #include <linux/errno.h> | |
33 | #include <linux/string.h> | |
34 | #include <linux/stat.h> | |
35 | #include <linux/socket.h> | |
36 | #include <linux/un.h> | |
37 | #include <linux/fcntl.h> | |
38 | #include <linux/termios.h> | |
39 | #include <linux/sockios.h> | |
40 | #include <linux/net.h> | |
41 | #include <linux/fs.h> | |
42 | #include <linux/slab.h> | |
43 | #include <asm/uaccess.h> | |
44 | #include <linux/skbuff.h> | |
45 | #include <linux/netdevice.h> | |
46 | #include <linux/rtnetlink.h> | |
47 | #include <linux/proc_fs.h> | |
48 | #include <linux/seq_file.h> | |
1da177e4 LT |
49 | #include <linux/notifier.h> |
50 | #include <linux/security.h> | |
51 | #include <linux/jhash.h> | |
52 | #include <linux/jiffies.h> | |
53 | #include <linux/random.h> | |
54 | #include <linux/bitops.h> | |
55 | #include <linux/mm.h> | |
56 | #include <linux/types.h> | |
54e0f520 | 57 | #include <linux/audit.h> |
af65bdfc | 58 | #include <linux/mutex.h> |
ccdfcc39 | 59 | #include <linux/vmalloc.h> |
bcbde0d4 | 60 | #include <linux/if_arp.h> |
9652e931 | 61 | #include <asm/cacheflush.h> |
54e0f520 | 62 | |
457c4cbc | 63 | #include <net/net_namespace.h> |
1da177e4 LT |
64 | #include <net/sock.h> |
65 | #include <net/scm.h> | |
82ace47a | 66 | #include <net/netlink.h> |
1da177e4 | 67 | |
0f29c768 | 68 | #include "af_netlink.h" |
1da177e4 | 69 | |
5c398dc8 ED |
70 | struct listeners { |
71 | struct rcu_head rcu; | |
72 | unsigned long masks[0]; | |
6c04bb18 JB |
73 | }; |
74 | ||
cd967e05 PM |
75 | /* state bits */ |
76 | #define NETLINK_CONGESTED 0x0 | |
77 | ||
78 | /* flags */ | |
77247bbb | 79 | #define NETLINK_KERNEL_SOCKET 0x1 |
9a4595bc | 80 | #define NETLINK_RECV_PKTINFO 0x2 |
be0c22a4 | 81 | #define NETLINK_BROADCAST_SEND_ERROR 0x4 |
38938bfe | 82 | #define NETLINK_RECV_NO_ENOBUFS 0x8 |
77247bbb | 83 | |
035c4c16 | 84 | static inline int netlink_is_kernel(struct sock *sk) |
aed81560 DL |
85 | { |
86 | return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET; | |
87 | } | |
88 | ||
0f29c768 AV |
89 | struct netlink_table *nl_table; |
90 | EXPORT_SYMBOL_GPL(nl_table); | |
1da177e4 LT |
91 | |
92 | static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); | |
93 | ||
94 | static int netlink_dump(struct sock *sk); | |
9652e931 | 95 | static void netlink_skb_destructor(struct sk_buff *skb); |
1da177e4 | 96 | |
0f29c768 AV |
97 | DEFINE_RWLOCK(nl_table_lock); |
98 | EXPORT_SYMBOL_GPL(nl_table_lock); | |
1da177e4 LT |
99 | static atomic_t nl_table_users = ATOMIC_INIT(0); |
100 | ||
6d772ac5 ED |
101 | #define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock)); |
102 | ||
e041c683 | 103 | static ATOMIC_NOTIFIER_HEAD(netlink_chain); |
1da177e4 | 104 | |
bcbde0d4 DB |
105 | static DEFINE_SPINLOCK(netlink_tap_lock); |
106 | static struct list_head netlink_tap_all __read_mostly; | |
107 | ||
b57ef81f | 108 | static inline u32 netlink_group_mask(u32 group) |
d629b836 PM |
109 | { |
110 | return group ? 1 << (group - 1) : 0; | |
111 | } | |
112 | ||
15e47304 | 113 | static inline struct hlist_head *nl_portid_hashfn(struct nl_portid_hash *hash, u32 portid) |
1da177e4 | 114 | { |
15e47304 | 115 | return &hash->table[jhash_1word(portid, hash->rnd) & hash->mask]; |
1da177e4 LT |
116 | } |
117 | ||
bcbde0d4 DB |
118 | int netlink_add_tap(struct netlink_tap *nt) |
119 | { | |
120 | if (unlikely(nt->dev->type != ARPHRD_NETLINK)) | |
121 | return -EINVAL; | |
122 | ||
123 | spin_lock(&netlink_tap_lock); | |
124 | list_add_rcu(&nt->list, &netlink_tap_all); | |
125 | spin_unlock(&netlink_tap_lock); | |
126 | ||
127 | if (nt->module) | |
128 | __module_get(nt->module); | |
129 | ||
130 | return 0; | |
131 | } | |
132 | EXPORT_SYMBOL_GPL(netlink_add_tap); | |
133 | ||
134 | int __netlink_remove_tap(struct netlink_tap *nt) | |
135 | { | |
136 | bool found = false; | |
137 | struct netlink_tap *tmp; | |
138 | ||
139 | spin_lock(&netlink_tap_lock); | |
140 | ||
141 | list_for_each_entry(tmp, &netlink_tap_all, list) { | |
142 | if (nt == tmp) { | |
143 | list_del_rcu(&nt->list); | |
144 | found = true; | |
145 | goto out; | |
146 | } | |
147 | } | |
148 | ||
149 | pr_warn("__netlink_remove_tap: %p not found\n", nt); | |
150 | out: | |
151 | spin_unlock(&netlink_tap_lock); | |
152 | ||
153 | if (found && nt->module) | |
154 | module_put(nt->module); | |
155 | ||
156 | return found ? 0 : -ENODEV; | |
157 | } | |
158 | EXPORT_SYMBOL_GPL(__netlink_remove_tap); | |
159 | ||
160 | int netlink_remove_tap(struct netlink_tap *nt) | |
161 | { | |
162 | int ret; | |
163 | ||
164 | ret = __netlink_remove_tap(nt); | |
165 | synchronize_net(); | |
166 | ||
167 | return ret; | |
168 | } | |
169 | EXPORT_SYMBOL_GPL(netlink_remove_tap); | |
170 | ||
5ffd5cdd DB |
171 | static bool netlink_filter_tap(const struct sk_buff *skb) |
172 | { | |
173 | struct sock *sk = skb->sk; | |
174 | bool pass = false; | |
175 | ||
176 | /* We take the more conservative approach and | |
177 | * whitelist socket protocols that may pass. | |
178 | */ | |
179 | switch (sk->sk_protocol) { | |
180 | case NETLINK_ROUTE: | |
181 | case NETLINK_USERSOCK: | |
182 | case NETLINK_SOCK_DIAG: | |
183 | case NETLINK_NFLOG: | |
184 | case NETLINK_XFRM: | |
185 | case NETLINK_FIB_LOOKUP: | |
186 | case NETLINK_NETFILTER: | |
187 | case NETLINK_GENERIC: | |
188 | pass = true; | |
189 | break; | |
190 | } | |
191 | ||
192 | return pass; | |
193 | } | |
194 | ||
bcbde0d4 DB |
195 | static int __netlink_deliver_tap_skb(struct sk_buff *skb, |
196 | struct net_device *dev) | |
197 | { | |
198 | struct sk_buff *nskb; | |
5ffd5cdd | 199 | struct sock *sk = skb->sk; |
bcbde0d4 DB |
200 | int ret = -ENOMEM; |
201 | ||
202 | dev_hold(dev); | |
203 | nskb = skb_clone(skb, GFP_ATOMIC); | |
204 | if (nskb) { | |
205 | nskb->dev = dev; | |
5ffd5cdd DB |
206 | nskb->protocol = htons((u16) sk->sk_protocol); |
207 | ||
bcbde0d4 DB |
208 | ret = dev_queue_xmit(nskb); |
209 | if (unlikely(ret > 0)) | |
210 | ret = net_xmit_errno(ret); | |
211 | } | |
212 | ||
213 | dev_put(dev); | |
214 | return ret; | |
215 | } | |
216 | ||
217 | static void __netlink_deliver_tap(struct sk_buff *skb) | |
218 | { | |
219 | int ret; | |
220 | struct netlink_tap *tmp; | |
221 | ||
5ffd5cdd DB |
222 | if (!netlink_filter_tap(skb)) |
223 | return; | |
224 | ||
bcbde0d4 DB |
225 | list_for_each_entry_rcu(tmp, &netlink_tap_all, list) { |
226 | ret = __netlink_deliver_tap_skb(skb, tmp->dev); | |
227 | if (unlikely(ret)) | |
228 | break; | |
229 | } | |
230 | } | |
231 | ||
232 | static void netlink_deliver_tap(struct sk_buff *skb) | |
233 | { | |
234 | rcu_read_lock(); | |
235 | ||
236 | if (unlikely(!list_empty(&netlink_tap_all))) | |
237 | __netlink_deliver_tap(skb); | |
238 | ||
239 | rcu_read_unlock(); | |
240 | } | |
241 | ||
cd1df525 PM |
242 | static void netlink_overrun(struct sock *sk) |
243 | { | |
244 | struct netlink_sock *nlk = nlk_sk(sk); | |
245 | ||
246 | if (!(nlk->flags & NETLINK_RECV_NO_ENOBUFS)) { | |
247 | if (!test_and_set_bit(NETLINK_CONGESTED, &nlk_sk(sk)->state)) { | |
248 | sk->sk_err = ENOBUFS; | |
249 | sk->sk_error_report(sk); | |
250 | } | |
251 | } | |
252 | atomic_inc(&sk->sk_drops); | |
253 | } | |
254 | ||
255 | static void netlink_rcv_wake(struct sock *sk) | |
256 | { | |
257 | struct netlink_sock *nlk = nlk_sk(sk); | |
258 | ||
259 | if (skb_queue_empty(&sk->sk_receive_queue)) | |
260 | clear_bit(NETLINK_CONGESTED, &nlk->state); | |
261 | if (!test_bit(NETLINK_CONGESTED, &nlk->state)) | |
262 | wake_up_interruptible(&nlk->wait); | |
263 | } | |
264 | ||
ccdfcc39 | 265 | #ifdef CONFIG_NETLINK_MMAP |
9652e931 PM |
266 | static bool netlink_skb_is_mmaped(const struct sk_buff *skb) |
267 | { | |
268 | return NETLINK_CB(skb).flags & NETLINK_SKB_MMAPED; | |
269 | } | |
270 | ||
f9c22888 PM |
271 | static bool netlink_rx_is_mmaped(struct sock *sk) |
272 | { | |
273 | return nlk_sk(sk)->rx_ring.pg_vec != NULL; | |
274 | } | |
275 | ||
5fd96123 PM |
276 | static bool netlink_tx_is_mmaped(struct sock *sk) |
277 | { | |
278 | return nlk_sk(sk)->tx_ring.pg_vec != NULL; | |
279 | } | |
280 | ||
ccdfcc39 PM |
281 | static __pure struct page *pgvec_to_page(const void *addr) |
282 | { | |
283 | if (is_vmalloc_addr(addr)) | |
284 | return vmalloc_to_page(addr); | |
285 | else | |
286 | return virt_to_page(addr); | |
287 | } | |
288 | ||
289 | static void free_pg_vec(void **pg_vec, unsigned int order, unsigned int len) | |
290 | { | |
291 | unsigned int i; | |
292 | ||
293 | for (i = 0; i < len; i++) { | |
294 | if (pg_vec[i] != NULL) { | |
295 | if (is_vmalloc_addr(pg_vec[i])) | |
296 | vfree(pg_vec[i]); | |
297 | else | |
298 | free_pages((unsigned long)pg_vec[i], order); | |
299 | } | |
300 | } | |
301 | kfree(pg_vec); | |
302 | } | |
303 | ||
304 | static void *alloc_one_pg_vec_page(unsigned long order) | |
305 | { | |
306 | void *buffer; | |
307 | gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | __GFP_ZERO | | |
308 | __GFP_NOWARN | __GFP_NORETRY; | |
309 | ||
310 | buffer = (void *)__get_free_pages(gfp_flags, order); | |
311 | if (buffer != NULL) | |
312 | return buffer; | |
313 | ||
314 | buffer = vzalloc((1 << order) * PAGE_SIZE); | |
315 | if (buffer != NULL) | |
316 | return buffer; | |
317 | ||
318 | gfp_flags &= ~__GFP_NORETRY; | |
319 | return (void *)__get_free_pages(gfp_flags, order); | |
320 | } | |
321 | ||
322 | static void **alloc_pg_vec(struct netlink_sock *nlk, | |
323 | struct nl_mmap_req *req, unsigned int order) | |
324 | { | |
325 | unsigned int block_nr = req->nm_block_nr; | |
326 | unsigned int i; | |
8a849bb7 | 327 | void **pg_vec; |
ccdfcc39 PM |
328 | |
329 | pg_vec = kcalloc(block_nr, sizeof(void *), GFP_KERNEL); | |
330 | if (pg_vec == NULL) | |
331 | return NULL; | |
332 | ||
333 | for (i = 0; i < block_nr; i++) { | |
8a849bb7 | 334 | pg_vec[i] = alloc_one_pg_vec_page(order); |
ccdfcc39 PM |
335 | if (pg_vec[i] == NULL) |
336 | goto err1; | |
337 | } | |
338 | ||
339 | return pg_vec; | |
340 | err1: | |
341 | free_pg_vec(pg_vec, order, block_nr); | |
342 | return NULL; | |
343 | } | |
344 | ||
345 | static int netlink_set_ring(struct sock *sk, struct nl_mmap_req *req, | |
346 | bool closing, bool tx_ring) | |
347 | { | |
348 | struct netlink_sock *nlk = nlk_sk(sk); | |
349 | struct netlink_ring *ring; | |
350 | struct sk_buff_head *queue; | |
351 | void **pg_vec = NULL; | |
352 | unsigned int order = 0; | |
353 | int err; | |
354 | ||
355 | ring = tx_ring ? &nlk->tx_ring : &nlk->rx_ring; | |
356 | queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue; | |
357 | ||
358 | if (!closing) { | |
359 | if (atomic_read(&nlk->mapped)) | |
360 | return -EBUSY; | |
361 | if (atomic_read(&ring->pending)) | |
362 | return -EBUSY; | |
363 | } | |
364 | ||
365 | if (req->nm_block_nr) { | |
366 | if (ring->pg_vec != NULL) | |
367 | return -EBUSY; | |
368 | ||
369 | if ((int)req->nm_block_size <= 0) | |
370 | return -EINVAL; | |
371 | if (!IS_ALIGNED(req->nm_block_size, PAGE_SIZE)) | |
372 | return -EINVAL; | |
373 | if (req->nm_frame_size < NL_MMAP_HDRLEN) | |
374 | return -EINVAL; | |
375 | if (!IS_ALIGNED(req->nm_frame_size, NL_MMAP_MSG_ALIGNMENT)) | |
376 | return -EINVAL; | |
377 | ||
378 | ring->frames_per_block = req->nm_block_size / | |
379 | req->nm_frame_size; | |
380 | if (ring->frames_per_block == 0) | |
381 | return -EINVAL; | |
382 | if (ring->frames_per_block * req->nm_block_nr != | |
383 | req->nm_frame_nr) | |
384 | return -EINVAL; | |
385 | ||
386 | order = get_order(req->nm_block_size); | |
387 | pg_vec = alloc_pg_vec(nlk, req, order); | |
388 | if (pg_vec == NULL) | |
389 | return -ENOMEM; | |
390 | } else { | |
391 | if (req->nm_frame_nr) | |
392 | return -EINVAL; | |
393 | } | |
394 | ||
395 | err = -EBUSY; | |
396 | mutex_lock(&nlk->pg_vec_lock); | |
397 | if (closing || atomic_read(&nlk->mapped) == 0) { | |
398 | err = 0; | |
399 | spin_lock_bh(&queue->lock); | |
400 | ||
401 | ring->frame_max = req->nm_frame_nr - 1; | |
402 | ring->head = 0; | |
403 | ring->frame_size = req->nm_frame_size; | |
404 | ring->pg_vec_pages = req->nm_block_size / PAGE_SIZE; | |
405 | ||
406 | swap(ring->pg_vec_len, req->nm_block_nr); | |
407 | swap(ring->pg_vec_order, order); | |
408 | swap(ring->pg_vec, pg_vec); | |
409 | ||
410 | __skb_queue_purge(queue); | |
411 | spin_unlock_bh(&queue->lock); | |
412 | ||
413 | WARN_ON(atomic_read(&nlk->mapped)); | |
414 | } | |
415 | mutex_unlock(&nlk->pg_vec_lock); | |
416 | ||
417 | if (pg_vec) | |
418 | free_pg_vec(pg_vec, order, req->nm_block_nr); | |
419 | return err; | |
420 | } | |
421 | ||
422 | static void netlink_mm_open(struct vm_area_struct *vma) | |
423 | { | |
424 | struct file *file = vma->vm_file; | |
425 | struct socket *sock = file->private_data; | |
426 | struct sock *sk = sock->sk; | |
427 | ||
428 | if (sk) | |
429 | atomic_inc(&nlk_sk(sk)->mapped); | |
430 | } | |
431 | ||
432 | static void netlink_mm_close(struct vm_area_struct *vma) | |
433 | { | |
434 | struct file *file = vma->vm_file; | |
435 | struct socket *sock = file->private_data; | |
436 | struct sock *sk = sock->sk; | |
437 | ||
438 | if (sk) | |
439 | atomic_dec(&nlk_sk(sk)->mapped); | |
440 | } | |
441 | ||
442 | static const struct vm_operations_struct netlink_mmap_ops = { | |
443 | .open = netlink_mm_open, | |
444 | .close = netlink_mm_close, | |
445 | }; | |
446 | ||
447 | static int netlink_mmap(struct file *file, struct socket *sock, | |
448 | struct vm_area_struct *vma) | |
449 | { | |
450 | struct sock *sk = sock->sk; | |
451 | struct netlink_sock *nlk = nlk_sk(sk); | |
452 | struct netlink_ring *ring; | |
453 | unsigned long start, size, expected; | |
454 | unsigned int i; | |
455 | int err = -EINVAL; | |
456 | ||
457 | if (vma->vm_pgoff) | |
458 | return -EINVAL; | |
459 | ||
460 | mutex_lock(&nlk->pg_vec_lock); | |
461 | ||
462 | expected = 0; | |
463 | for (ring = &nlk->rx_ring; ring <= &nlk->tx_ring; ring++) { | |
464 | if (ring->pg_vec == NULL) | |
465 | continue; | |
466 | expected += ring->pg_vec_len * ring->pg_vec_pages * PAGE_SIZE; | |
467 | } | |
468 | ||
469 | if (expected == 0) | |
470 | goto out; | |
471 | ||
472 | size = vma->vm_end - vma->vm_start; | |
473 | if (size != expected) | |
474 | goto out; | |
475 | ||
476 | start = vma->vm_start; | |
477 | for (ring = &nlk->rx_ring; ring <= &nlk->tx_ring; ring++) { | |
478 | if (ring->pg_vec == NULL) | |
479 | continue; | |
480 | ||
481 | for (i = 0; i < ring->pg_vec_len; i++) { | |
482 | struct page *page; | |
483 | void *kaddr = ring->pg_vec[i]; | |
484 | unsigned int pg_num; | |
485 | ||
486 | for (pg_num = 0; pg_num < ring->pg_vec_pages; pg_num++) { | |
487 | page = pgvec_to_page(kaddr); | |
488 | err = vm_insert_page(vma, start, page); | |
489 | if (err < 0) | |
490 | goto out; | |
491 | start += PAGE_SIZE; | |
492 | kaddr += PAGE_SIZE; | |
493 | } | |
494 | } | |
495 | } | |
496 | ||
497 | atomic_inc(&nlk->mapped); | |
498 | vma->vm_ops = &netlink_mmap_ops; | |
499 | err = 0; | |
500 | out: | |
501 | mutex_unlock(&nlk->pg_vec_lock); | |
7cdbac71 | 502 | return err; |
ccdfcc39 | 503 | } |
9652e931 PM |
504 | |
505 | static void netlink_frame_flush_dcache(const struct nl_mmap_hdr *hdr) | |
506 | { | |
507 | #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1 | |
508 | struct page *p_start, *p_end; | |
509 | ||
510 | /* First page is flushed through netlink_{get,set}_status */ | |
511 | p_start = pgvec_to_page(hdr + PAGE_SIZE); | |
1d5085cb | 512 | p_end = pgvec_to_page((void *)hdr + NL_MMAP_HDRLEN + hdr->nm_len - 1); |
9652e931 PM |
513 | while (p_start <= p_end) { |
514 | flush_dcache_page(p_start); | |
515 | p_start++; | |
516 | } | |
517 | #endif | |
518 | } | |
519 | ||
520 | static enum nl_mmap_status netlink_get_status(const struct nl_mmap_hdr *hdr) | |
521 | { | |
522 | smp_rmb(); | |
523 | flush_dcache_page(pgvec_to_page(hdr)); | |
524 | return hdr->nm_status; | |
525 | } | |
526 | ||
527 | static void netlink_set_status(struct nl_mmap_hdr *hdr, | |
528 | enum nl_mmap_status status) | |
529 | { | |
530 | hdr->nm_status = status; | |
531 | flush_dcache_page(pgvec_to_page(hdr)); | |
532 | smp_wmb(); | |
533 | } | |
534 | ||
535 | static struct nl_mmap_hdr * | |
536 | __netlink_lookup_frame(const struct netlink_ring *ring, unsigned int pos) | |
537 | { | |
538 | unsigned int pg_vec_pos, frame_off; | |
539 | ||
540 | pg_vec_pos = pos / ring->frames_per_block; | |
541 | frame_off = pos % ring->frames_per_block; | |
542 | ||
543 | return ring->pg_vec[pg_vec_pos] + (frame_off * ring->frame_size); | |
544 | } | |
545 | ||
546 | static struct nl_mmap_hdr * | |
547 | netlink_lookup_frame(const struct netlink_ring *ring, unsigned int pos, | |
548 | enum nl_mmap_status status) | |
549 | { | |
550 | struct nl_mmap_hdr *hdr; | |
551 | ||
552 | hdr = __netlink_lookup_frame(ring, pos); | |
553 | if (netlink_get_status(hdr) != status) | |
554 | return NULL; | |
555 | ||
556 | return hdr; | |
557 | } | |
558 | ||
559 | static struct nl_mmap_hdr * | |
560 | netlink_current_frame(const struct netlink_ring *ring, | |
561 | enum nl_mmap_status status) | |
562 | { | |
563 | return netlink_lookup_frame(ring, ring->head, status); | |
564 | } | |
565 | ||
566 | static struct nl_mmap_hdr * | |
567 | netlink_previous_frame(const struct netlink_ring *ring, | |
568 | enum nl_mmap_status status) | |
569 | { | |
570 | unsigned int prev; | |
571 | ||
572 | prev = ring->head ? ring->head - 1 : ring->frame_max; | |
573 | return netlink_lookup_frame(ring, prev, status); | |
574 | } | |
575 | ||
576 | static void netlink_increment_head(struct netlink_ring *ring) | |
577 | { | |
578 | ring->head = ring->head != ring->frame_max ? ring->head + 1 : 0; | |
579 | } | |
580 | ||
581 | static void netlink_forward_ring(struct netlink_ring *ring) | |
582 | { | |
583 | unsigned int head = ring->head, pos = head; | |
584 | const struct nl_mmap_hdr *hdr; | |
585 | ||
586 | do { | |
587 | hdr = __netlink_lookup_frame(ring, pos); | |
588 | if (hdr->nm_status == NL_MMAP_STATUS_UNUSED) | |
589 | break; | |
590 | if (hdr->nm_status != NL_MMAP_STATUS_SKIP) | |
591 | break; | |
592 | netlink_increment_head(ring); | |
593 | } while (ring->head != head); | |
594 | } | |
595 | ||
cd1df525 PM |
596 | static bool netlink_dump_space(struct netlink_sock *nlk) |
597 | { | |
598 | struct netlink_ring *ring = &nlk->rx_ring; | |
599 | struct nl_mmap_hdr *hdr; | |
600 | unsigned int n; | |
601 | ||
602 | hdr = netlink_current_frame(ring, NL_MMAP_STATUS_UNUSED); | |
603 | if (hdr == NULL) | |
604 | return false; | |
605 | ||
606 | n = ring->head + ring->frame_max / 2; | |
607 | if (n > ring->frame_max) | |
608 | n -= ring->frame_max; | |
609 | ||
610 | hdr = __netlink_lookup_frame(ring, n); | |
611 | ||
612 | return hdr->nm_status == NL_MMAP_STATUS_UNUSED; | |
613 | } | |
614 | ||
9652e931 PM |
615 | static unsigned int netlink_poll(struct file *file, struct socket *sock, |
616 | poll_table *wait) | |
617 | { | |
618 | struct sock *sk = sock->sk; | |
619 | struct netlink_sock *nlk = nlk_sk(sk); | |
620 | unsigned int mask; | |
cd1df525 | 621 | int err; |
9652e931 | 622 | |
cd1df525 PM |
623 | if (nlk->rx_ring.pg_vec != NULL) { |
624 | /* Memory mapped sockets don't call recvmsg(), so flow control | |
625 | * for dumps is performed here. A dump is allowed to continue | |
626 | * if at least half the ring is unused. | |
627 | */ | |
16b304f3 | 628 | while (nlk->cb_running && netlink_dump_space(nlk)) { |
cd1df525 PM |
629 | err = netlink_dump(sk); |
630 | if (err < 0) { | |
631 | sk->sk_err = err; | |
632 | sk->sk_error_report(sk); | |
633 | break; | |
634 | } | |
635 | } | |
636 | netlink_rcv_wake(sk); | |
637 | } | |
5fd96123 | 638 | |
9652e931 PM |
639 | mask = datagram_poll(file, sock, wait); |
640 | ||
641 | spin_lock_bh(&sk->sk_receive_queue.lock); | |
642 | if (nlk->rx_ring.pg_vec) { | |
643 | netlink_forward_ring(&nlk->rx_ring); | |
644 | if (!netlink_previous_frame(&nlk->rx_ring, NL_MMAP_STATUS_UNUSED)) | |
645 | mask |= POLLIN | POLLRDNORM; | |
646 | } | |
647 | spin_unlock_bh(&sk->sk_receive_queue.lock); | |
648 | ||
649 | spin_lock_bh(&sk->sk_write_queue.lock); | |
650 | if (nlk->tx_ring.pg_vec) { | |
651 | if (netlink_current_frame(&nlk->tx_ring, NL_MMAP_STATUS_UNUSED)) | |
652 | mask |= POLLOUT | POLLWRNORM; | |
653 | } | |
654 | spin_unlock_bh(&sk->sk_write_queue.lock); | |
655 | ||
656 | return mask; | |
657 | } | |
658 | ||
659 | static struct nl_mmap_hdr *netlink_mmap_hdr(struct sk_buff *skb) | |
660 | { | |
661 | return (struct nl_mmap_hdr *)(skb->head - NL_MMAP_HDRLEN); | |
662 | } | |
663 | ||
664 | static void netlink_ring_setup_skb(struct sk_buff *skb, struct sock *sk, | |
665 | struct netlink_ring *ring, | |
666 | struct nl_mmap_hdr *hdr) | |
667 | { | |
668 | unsigned int size; | |
669 | void *data; | |
670 | ||
671 | size = ring->frame_size - NL_MMAP_HDRLEN; | |
672 | data = (void *)hdr + NL_MMAP_HDRLEN; | |
673 | ||
674 | skb->head = data; | |
675 | skb->data = data; | |
676 | skb_reset_tail_pointer(skb); | |
677 | skb->end = skb->tail + size; | |
678 | skb->len = 0; | |
679 | ||
680 | skb->destructor = netlink_skb_destructor; | |
681 | NETLINK_CB(skb).flags |= NETLINK_SKB_MMAPED; | |
682 | NETLINK_CB(skb).sk = sk; | |
683 | } | |
5fd96123 PM |
684 | |
685 | static int netlink_mmap_sendmsg(struct sock *sk, struct msghdr *msg, | |
686 | u32 dst_portid, u32 dst_group, | |
687 | struct sock_iocb *siocb) | |
688 | { | |
689 | struct netlink_sock *nlk = nlk_sk(sk); | |
690 | struct netlink_ring *ring; | |
691 | struct nl_mmap_hdr *hdr; | |
692 | struct sk_buff *skb; | |
693 | unsigned int maxlen; | |
694 | bool excl = true; | |
695 | int err = 0, len = 0; | |
696 | ||
697 | /* Netlink messages are validated by the receiver before processing. | |
698 | * In order to avoid userspace changing the contents of the message | |
699 | * after validation, the socket and the ring may only be used by a | |
700 | * single process, otherwise we fall back to copying. | |
701 | */ | |
702 | if (atomic_long_read(&sk->sk_socket->file->f_count) > 2 || | |
703 | atomic_read(&nlk->mapped) > 1) | |
704 | excl = false; | |
705 | ||
706 | mutex_lock(&nlk->pg_vec_lock); | |
707 | ||
708 | ring = &nlk->tx_ring; | |
709 | maxlen = ring->frame_size - NL_MMAP_HDRLEN; | |
710 | ||
711 | do { | |
712 | hdr = netlink_current_frame(ring, NL_MMAP_STATUS_VALID); | |
713 | if (hdr == NULL) { | |
714 | if (!(msg->msg_flags & MSG_DONTWAIT) && | |
715 | atomic_read(&nlk->tx_ring.pending)) | |
716 | schedule(); | |
717 | continue; | |
718 | } | |
719 | if (hdr->nm_len > maxlen) { | |
720 | err = -EINVAL; | |
721 | goto out; | |
722 | } | |
723 | ||
724 | netlink_frame_flush_dcache(hdr); | |
725 | ||
726 | if (likely(dst_portid == 0 && dst_group == 0 && excl)) { | |
727 | skb = alloc_skb_head(GFP_KERNEL); | |
728 | if (skb == NULL) { | |
729 | err = -ENOBUFS; | |
730 | goto out; | |
731 | } | |
732 | sock_hold(sk); | |
733 | netlink_ring_setup_skb(skb, sk, ring, hdr); | |
734 | NETLINK_CB(skb).flags |= NETLINK_SKB_TX; | |
735 | __skb_put(skb, hdr->nm_len); | |
736 | netlink_set_status(hdr, NL_MMAP_STATUS_RESERVED); | |
737 | atomic_inc(&ring->pending); | |
738 | } else { | |
739 | skb = alloc_skb(hdr->nm_len, GFP_KERNEL); | |
740 | if (skb == NULL) { | |
741 | err = -ENOBUFS; | |
742 | goto out; | |
743 | } | |
744 | __skb_put(skb, hdr->nm_len); | |
745 | memcpy(skb->data, (void *)hdr + NL_MMAP_HDRLEN, hdr->nm_len); | |
746 | netlink_set_status(hdr, NL_MMAP_STATUS_UNUSED); | |
747 | } | |
748 | ||
749 | netlink_increment_head(ring); | |
750 | ||
751 | NETLINK_CB(skb).portid = nlk->portid; | |
752 | NETLINK_CB(skb).dst_group = dst_group; | |
753 | NETLINK_CB(skb).creds = siocb->scm->creds; | |
754 | ||
755 | err = security_netlink_send(sk, skb); | |
756 | if (err) { | |
757 | kfree_skb(skb); | |
758 | goto out; | |
759 | } | |
760 | ||
761 | if (unlikely(dst_group)) { | |
762 | atomic_inc(&skb->users); | |
763 | netlink_broadcast(sk, skb, dst_portid, dst_group, | |
764 | GFP_KERNEL); | |
765 | } | |
766 | err = netlink_unicast(sk, skb, dst_portid, | |
767 | msg->msg_flags & MSG_DONTWAIT); | |
768 | if (err < 0) | |
769 | goto out; | |
770 | len += err; | |
771 | ||
772 | } while (hdr != NULL || | |
773 | (!(msg->msg_flags & MSG_DONTWAIT) && | |
774 | atomic_read(&nlk->tx_ring.pending))); | |
775 | ||
776 | if (len > 0) | |
777 | err = len; | |
778 | out: | |
779 | mutex_unlock(&nlk->pg_vec_lock); | |
780 | return err; | |
781 | } | |
f9c22888 PM |
782 | |
783 | static void netlink_queue_mmaped_skb(struct sock *sk, struct sk_buff *skb) | |
784 | { | |
785 | struct nl_mmap_hdr *hdr; | |
786 | ||
787 | hdr = netlink_mmap_hdr(skb); | |
788 | hdr->nm_len = skb->len; | |
789 | hdr->nm_group = NETLINK_CB(skb).dst_group; | |
790 | hdr->nm_pid = NETLINK_CB(skb).creds.pid; | |
1bf9310a ND |
791 | hdr->nm_uid = from_kuid(sk_user_ns(sk), NETLINK_CB(skb).creds.uid); |
792 | hdr->nm_gid = from_kgid(sk_user_ns(sk), NETLINK_CB(skb).creds.gid); | |
f9c22888 PM |
793 | netlink_frame_flush_dcache(hdr); |
794 | netlink_set_status(hdr, NL_MMAP_STATUS_VALID); | |
795 | ||
796 | NETLINK_CB(skb).flags |= NETLINK_SKB_DELIVERED; | |
797 | kfree_skb(skb); | |
798 | } | |
799 | ||
800 | static void netlink_ring_set_copied(struct sock *sk, struct sk_buff *skb) | |
801 | { | |
802 | struct netlink_sock *nlk = nlk_sk(sk); | |
803 | struct netlink_ring *ring = &nlk->rx_ring; | |
804 | struct nl_mmap_hdr *hdr; | |
805 | ||
806 | spin_lock_bh(&sk->sk_receive_queue.lock); | |
807 | hdr = netlink_current_frame(ring, NL_MMAP_STATUS_UNUSED); | |
808 | if (hdr == NULL) { | |
809 | spin_unlock_bh(&sk->sk_receive_queue.lock); | |
810 | kfree_skb(skb); | |
cd1df525 | 811 | netlink_overrun(sk); |
f9c22888 PM |
812 | return; |
813 | } | |
814 | netlink_increment_head(ring); | |
815 | __skb_queue_tail(&sk->sk_receive_queue, skb); | |
816 | spin_unlock_bh(&sk->sk_receive_queue.lock); | |
817 | ||
818 | hdr->nm_len = skb->len; | |
819 | hdr->nm_group = NETLINK_CB(skb).dst_group; | |
820 | hdr->nm_pid = NETLINK_CB(skb).creds.pid; | |
1bf9310a ND |
821 | hdr->nm_uid = from_kuid(sk_user_ns(sk), NETLINK_CB(skb).creds.uid); |
822 | hdr->nm_gid = from_kgid(sk_user_ns(sk), NETLINK_CB(skb).creds.gid); | |
f9c22888 PM |
823 | netlink_set_status(hdr, NL_MMAP_STATUS_COPY); |
824 | } | |
825 | ||
ccdfcc39 | 826 | #else /* CONFIG_NETLINK_MMAP */ |
9652e931 | 827 | #define netlink_skb_is_mmaped(skb) false |
f9c22888 | 828 | #define netlink_rx_is_mmaped(sk) false |
5fd96123 | 829 | #define netlink_tx_is_mmaped(sk) false |
ccdfcc39 | 830 | #define netlink_mmap sock_no_mmap |
9652e931 | 831 | #define netlink_poll datagram_poll |
5fd96123 | 832 | #define netlink_mmap_sendmsg(sk, msg, dst_portid, dst_group, siocb) 0 |
ccdfcc39 PM |
833 | #endif /* CONFIG_NETLINK_MMAP */ |
834 | ||
cf0a018a PM |
835 | static void netlink_skb_destructor(struct sk_buff *skb) |
836 | { | |
9652e931 PM |
837 | #ifdef CONFIG_NETLINK_MMAP |
838 | struct nl_mmap_hdr *hdr; | |
839 | struct netlink_ring *ring; | |
840 | struct sock *sk; | |
841 | ||
842 | /* If a packet from the kernel to userspace was freed because of an | |
843 | * error without being delivered to userspace, the kernel must reset | |
844 | * the status. In the direction userspace to kernel, the status is | |
845 | * always reset here after the packet was processed and freed. | |
846 | */ | |
847 | if (netlink_skb_is_mmaped(skb)) { | |
848 | hdr = netlink_mmap_hdr(skb); | |
849 | sk = NETLINK_CB(skb).sk; | |
850 | ||
5fd96123 PM |
851 | if (NETLINK_CB(skb).flags & NETLINK_SKB_TX) { |
852 | netlink_set_status(hdr, NL_MMAP_STATUS_UNUSED); | |
853 | ring = &nlk_sk(sk)->tx_ring; | |
854 | } else { | |
855 | if (!(NETLINK_CB(skb).flags & NETLINK_SKB_DELIVERED)) { | |
856 | hdr->nm_len = 0; | |
857 | netlink_set_status(hdr, NL_MMAP_STATUS_VALID); | |
858 | } | |
859 | ring = &nlk_sk(sk)->rx_ring; | |
9652e931 | 860 | } |
9652e931 PM |
861 | |
862 | WARN_ON(atomic_read(&ring->pending) == 0); | |
863 | atomic_dec(&ring->pending); | |
864 | sock_put(sk); | |
865 | ||
5e71d9d7 | 866 | skb->head = NULL; |
9652e931 PM |
867 | } |
868 | #endif | |
c05cdb1b | 869 | if (is_vmalloc_addr(skb->head)) { |
3a36515f PN |
870 | if (!skb->cloned || |
871 | !atomic_dec_return(&(skb_shinfo(skb)->dataref))) | |
872 | vfree(skb->head); | |
873 | ||
c05cdb1b PNA |
874 | skb->head = NULL; |
875 | } | |
9652e931 PM |
876 | if (skb->sk != NULL) |
877 | sock_rfree(skb); | |
cf0a018a PM |
878 | } |
879 | ||
880 | static void netlink_skb_set_owner_r(struct sk_buff *skb, struct sock *sk) | |
881 | { | |
882 | WARN_ON(skb->sk != NULL); | |
883 | skb->sk = sk; | |
884 | skb->destructor = netlink_skb_destructor; | |
885 | atomic_add(skb->truesize, &sk->sk_rmem_alloc); | |
886 | sk_mem_charge(sk, skb->truesize); | |
887 | } | |
888 | ||
1da177e4 LT |
889 | static void netlink_sock_destruct(struct sock *sk) |
890 | { | |
3f660d66 HX |
891 | struct netlink_sock *nlk = nlk_sk(sk); |
892 | ||
16b304f3 PS |
893 | if (nlk->cb_running) { |
894 | if (nlk->cb.done) | |
895 | nlk->cb.done(&nlk->cb); | |
6dc878a8 | 896 | |
16b304f3 PS |
897 | module_put(nlk->cb.module); |
898 | kfree_skb(nlk->cb.skb); | |
3f660d66 HX |
899 | } |
900 | ||
1da177e4 | 901 | skb_queue_purge(&sk->sk_receive_queue); |
ccdfcc39 PM |
902 | #ifdef CONFIG_NETLINK_MMAP |
903 | if (1) { | |
904 | struct nl_mmap_req req; | |
905 | ||
906 | memset(&req, 0, sizeof(req)); | |
907 | if (nlk->rx_ring.pg_vec) | |
908 | netlink_set_ring(sk, &req, true, false); | |
909 | memset(&req, 0, sizeof(req)); | |
910 | if (nlk->tx_ring.pg_vec) | |
911 | netlink_set_ring(sk, &req, true, true); | |
912 | } | |
913 | #endif /* CONFIG_NETLINK_MMAP */ | |
1da177e4 LT |
914 | |
915 | if (!sock_flag(sk, SOCK_DEAD)) { | |
6ac552fd | 916 | printk(KERN_ERR "Freeing alive netlink socket %p\n", sk); |
1da177e4 LT |
917 | return; |
918 | } | |
547b792c IJ |
919 | |
920 | WARN_ON(atomic_read(&sk->sk_rmem_alloc)); | |
921 | WARN_ON(atomic_read(&sk->sk_wmem_alloc)); | |
922 | WARN_ON(nlk_sk(sk)->groups); | |
1da177e4 LT |
923 | } |
924 | ||
6ac552fd PM |
925 | /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on |
926 | * SMP. Look, when several writers sleep and reader wakes them up, all but one | |
1da177e4 LT |
927 | * immediately hit write lock and grab all the cpus. Exclusive sleep solves |
928 | * this, _but_ remember, it adds useless work on UP machines. | |
929 | */ | |
930 | ||
d136f1bd | 931 | void netlink_table_grab(void) |
9a429c49 | 932 | __acquires(nl_table_lock) |
1da177e4 | 933 | { |
d136f1bd JB |
934 | might_sleep(); |
935 | ||
6abd219c | 936 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
937 | |
938 | if (atomic_read(&nl_table_users)) { | |
939 | DECLARE_WAITQUEUE(wait, current); | |
940 | ||
941 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
6ac552fd | 942 | for (;;) { |
1da177e4 LT |
943 | set_current_state(TASK_UNINTERRUPTIBLE); |
944 | if (atomic_read(&nl_table_users) == 0) | |
945 | break; | |
6abd219c | 946 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 947 | schedule(); |
6abd219c | 948 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
949 | } |
950 | ||
951 | __set_current_state(TASK_RUNNING); | |
952 | remove_wait_queue(&nl_table_wait, &wait); | |
953 | } | |
954 | } | |
955 | ||
d136f1bd | 956 | void netlink_table_ungrab(void) |
9a429c49 | 957 | __releases(nl_table_lock) |
1da177e4 | 958 | { |
6abd219c | 959 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
960 | wake_up(&nl_table_wait); |
961 | } | |
962 | ||
6ac552fd | 963 | static inline void |
1da177e4 LT |
964 | netlink_lock_table(void) |
965 | { | |
966 | /* read_lock() synchronizes us to netlink_table_grab */ | |
967 | ||
968 | read_lock(&nl_table_lock); | |
969 | atomic_inc(&nl_table_users); | |
970 | read_unlock(&nl_table_lock); | |
971 | } | |
972 | ||
6ac552fd | 973 | static inline void |
1da177e4 LT |
974 | netlink_unlock_table(void) |
975 | { | |
976 | if (atomic_dec_and_test(&nl_table_users)) | |
977 | wake_up(&nl_table_wait); | |
978 | } | |
979 | ||
da12c90e G |
980 | static bool netlink_compare(struct net *net, struct sock *sk) |
981 | { | |
982 | return net_eq(sock_net(sk), net); | |
983 | } | |
984 | ||
15e47304 | 985 | static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid) |
1da177e4 | 986 | { |
da12c90e G |
987 | struct netlink_table *table = &nl_table[protocol]; |
988 | struct nl_portid_hash *hash = &table->hash; | |
1da177e4 LT |
989 | struct hlist_head *head; |
990 | struct sock *sk; | |
1da177e4 LT |
991 | |
992 | read_lock(&nl_table_lock); | |
15e47304 | 993 | head = nl_portid_hashfn(hash, portid); |
b67bfe0d | 994 | sk_for_each(sk, head) { |
da12c90e G |
995 | if (table->compare(net, sk) && |
996 | (nlk_sk(sk)->portid == portid)) { | |
1da177e4 LT |
997 | sock_hold(sk); |
998 | goto found; | |
999 | } | |
1000 | } | |
1001 | sk = NULL; | |
1002 | found: | |
1003 | read_unlock(&nl_table_lock); | |
1004 | return sk; | |
1005 | } | |
1006 | ||
15e47304 | 1007 | static struct hlist_head *nl_portid_hash_zalloc(size_t size) |
1da177e4 LT |
1008 | { |
1009 | if (size <= PAGE_SIZE) | |
ea72912c | 1010 | return kzalloc(size, GFP_ATOMIC); |
1da177e4 LT |
1011 | else |
1012 | return (struct hlist_head *) | |
ea72912c ED |
1013 | __get_free_pages(GFP_ATOMIC | __GFP_ZERO, |
1014 | get_order(size)); | |
1da177e4 LT |
1015 | } |
1016 | ||
15e47304 | 1017 | static void nl_portid_hash_free(struct hlist_head *table, size_t size) |
1da177e4 LT |
1018 | { |
1019 | if (size <= PAGE_SIZE) | |
1020 | kfree(table); | |
1021 | else | |
1022 | free_pages((unsigned long)table, get_order(size)); | |
1023 | } | |
1024 | ||
15e47304 | 1025 | static int nl_portid_hash_rehash(struct nl_portid_hash *hash, int grow) |
1da177e4 LT |
1026 | { |
1027 | unsigned int omask, mask, shift; | |
1028 | size_t osize, size; | |
1029 | struct hlist_head *otable, *table; | |
1030 | int i; | |
1031 | ||
1032 | omask = mask = hash->mask; | |
1033 | osize = size = (mask + 1) * sizeof(*table); | |
1034 | shift = hash->shift; | |
1035 | ||
1036 | if (grow) { | |
1037 | if (++shift > hash->max_shift) | |
1038 | return 0; | |
1039 | mask = mask * 2 + 1; | |
1040 | size *= 2; | |
1041 | } | |
1042 | ||
15e47304 | 1043 | table = nl_portid_hash_zalloc(size); |
1da177e4 LT |
1044 | if (!table) |
1045 | return 0; | |
1046 | ||
1da177e4 LT |
1047 | otable = hash->table; |
1048 | hash->table = table; | |
1049 | hash->mask = mask; | |
1050 | hash->shift = shift; | |
1051 | get_random_bytes(&hash->rnd, sizeof(hash->rnd)); | |
1052 | ||
1053 | for (i = 0; i <= omask; i++) { | |
1054 | struct sock *sk; | |
b67bfe0d | 1055 | struct hlist_node *tmp; |
1da177e4 | 1056 | |
b67bfe0d | 1057 | sk_for_each_safe(sk, tmp, &otable[i]) |
15e47304 | 1058 | __sk_add_node(sk, nl_portid_hashfn(hash, nlk_sk(sk)->portid)); |
1da177e4 LT |
1059 | } |
1060 | ||
15e47304 | 1061 | nl_portid_hash_free(otable, osize); |
1da177e4 LT |
1062 | hash->rehash_time = jiffies + 10 * 60 * HZ; |
1063 | return 1; | |
1064 | } | |
1065 | ||
15e47304 | 1066 | static inline int nl_portid_hash_dilute(struct nl_portid_hash *hash, int len) |
1da177e4 LT |
1067 | { |
1068 | int avg = hash->entries >> hash->shift; | |
1069 | ||
15e47304 | 1070 | if (unlikely(avg > 1) && nl_portid_hash_rehash(hash, 1)) |
1da177e4 LT |
1071 | return 1; |
1072 | ||
1073 | if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) { | |
15e47304 | 1074 | nl_portid_hash_rehash(hash, 0); |
1da177e4 LT |
1075 | return 1; |
1076 | } | |
1077 | ||
1078 | return 0; | |
1079 | } | |
1080 | ||
90ddc4f0 | 1081 | static const struct proto_ops netlink_ops; |
1da177e4 | 1082 | |
4277a083 PM |
1083 | static void |
1084 | netlink_update_listeners(struct sock *sk) | |
1085 | { | |
1086 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
4277a083 PM |
1087 | unsigned long mask; |
1088 | unsigned int i; | |
6d772ac5 ED |
1089 | struct listeners *listeners; |
1090 | ||
1091 | listeners = nl_deref_protected(tbl->listeners); | |
1092 | if (!listeners) | |
1093 | return; | |
4277a083 | 1094 | |
b4ff4f04 | 1095 | for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
4277a083 | 1096 | mask = 0; |
b67bfe0d | 1097 | sk_for_each_bound(sk, &tbl->mc_list) { |
b4ff4f04 JB |
1098 | if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) |
1099 | mask |= nlk_sk(sk)->groups[i]; | |
1100 | } | |
6d772ac5 | 1101 | listeners->masks[i] = mask; |
4277a083 PM |
1102 | } |
1103 | /* this function is only called with the netlink table "grabbed", which | |
1104 | * makes sure updates are visible before bind or setsockopt return. */ | |
1105 | } | |
1106 | ||
15e47304 | 1107 | static int netlink_insert(struct sock *sk, struct net *net, u32 portid) |
1da177e4 | 1108 | { |
da12c90e G |
1109 | struct netlink_table *table = &nl_table[sk->sk_protocol]; |
1110 | struct nl_portid_hash *hash = &table->hash; | |
1da177e4 LT |
1111 | struct hlist_head *head; |
1112 | int err = -EADDRINUSE; | |
1113 | struct sock *osk; | |
1da177e4 LT |
1114 | int len; |
1115 | ||
1116 | netlink_table_grab(); | |
15e47304 | 1117 | head = nl_portid_hashfn(hash, portid); |
1da177e4 | 1118 | len = 0; |
b67bfe0d | 1119 | sk_for_each(osk, head) { |
da12c90e G |
1120 | if (table->compare(net, osk) && |
1121 | (nlk_sk(osk)->portid == portid)) | |
1da177e4 LT |
1122 | break; |
1123 | len++; | |
1124 | } | |
b67bfe0d | 1125 | if (osk) |
1da177e4 LT |
1126 | goto err; |
1127 | ||
1128 | err = -EBUSY; | |
15e47304 | 1129 | if (nlk_sk(sk)->portid) |
1da177e4 LT |
1130 | goto err; |
1131 | ||
1132 | err = -ENOMEM; | |
1133 | if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX)) | |
1134 | goto err; | |
1135 | ||
15e47304 EB |
1136 | if (len && nl_portid_hash_dilute(hash, len)) |
1137 | head = nl_portid_hashfn(hash, portid); | |
1da177e4 | 1138 | hash->entries++; |
15e47304 | 1139 | nlk_sk(sk)->portid = portid; |
1da177e4 LT |
1140 | sk_add_node(sk, head); |
1141 | err = 0; | |
1142 | ||
1143 | err: | |
1144 | netlink_table_ungrab(); | |
1145 | return err; | |
1146 | } | |
1147 | ||
1148 | static void netlink_remove(struct sock *sk) | |
1149 | { | |
1150 | netlink_table_grab(); | |
d470e3b4 DM |
1151 | if (sk_del_node_init(sk)) |
1152 | nl_table[sk->sk_protocol].hash.entries--; | |
f7fa9b10 | 1153 | if (nlk_sk(sk)->subscriptions) |
1da177e4 LT |
1154 | __sk_del_bind_node(sk); |
1155 | netlink_table_ungrab(); | |
1156 | } | |
1157 | ||
1158 | static struct proto netlink_proto = { | |
1159 | .name = "NETLINK", | |
1160 | .owner = THIS_MODULE, | |
1161 | .obj_size = sizeof(struct netlink_sock), | |
1162 | }; | |
1163 | ||
1b8d7ae4 EB |
1164 | static int __netlink_create(struct net *net, struct socket *sock, |
1165 | struct mutex *cb_mutex, int protocol) | |
1da177e4 LT |
1166 | { |
1167 | struct sock *sk; | |
1168 | struct netlink_sock *nlk; | |
ab33a171 PM |
1169 | |
1170 | sock->ops = &netlink_ops; | |
1171 | ||
6257ff21 | 1172 | sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto); |
ab33a171 PM |
1173 | if (!sk) |
1174 | return -ENOMEM; | |
1175 | ||
1176 | sock_init_data(sock, sk); | |
1177 | ||
1178 | nlk = nlk_sk(sk); | |
658cb354 | 1179 | if (cb_mutex) { |
ffa4d721 | 1180 | nlk->cb_mutex = cb_mutex; |
658cb354 | 1181 | } else { |
ffa4d721 PM |
1182 | nlk->cb_mutex = &nlk->cb_def_mutex; |
1183 | mutex_init(nlk->cb_mutex); | |
1184 | } | |
ab33a171 | 1185 | init_waitqueue_head(&nlk->wait); |
ccdfcc39 PM |
1186 | #ifdef CONFIG_NETLINK_MMAP |
1187 | mutex_init(&nlk->pg_vec_lock); | |
1188 | #endif | |
ab33a171 PM |
1189 | |
1190 | sk->sk_destruct = netlink_sock_destruct; | |
1191 | sk->sk_protocol = protocol; | |
1192 | return 0; | |
1193 | } | |
1194 | ||
3f378b68 EP |
1195 | static int netlink_create(struct net *net, struct socket *sock, int protocol, |
1196 | int kern) | |
ab33a171 PM |
1197 | { |
1198 | struct module *module = NULL; | |
af65bdfc | 1199 | struct mutex *cb_mutex; |
f7fa9b10 | 1200 | struct netlink_sock *nlk; |
03292745 | 1201 | void (*bind)(int group); |
ab33a171 | 1202 | int err = 0; |
1da177e4 LT |
1203 | |
1204 | sock->state = SS_UNCONNECTED; | |
1205 | ||
1206 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
1207 | return -ESOCKTNOSUPPORT; | |
1208 | ||
6ac552fd | 1209 | if (protocol < 0 || protocol >= MAX_LINKS) |
1da177e4 LT |
1210 | return -EPROTONOSUPPORT; |
1211 | ||
77247bbb | 1212 | netlink_lock_table(); |
95a5afca | 1213 | #ifdef CONFIG_MODULES |
ab33a171 | 1214 | if (!nl_table[protocol].registered) { |
77247bbb | 1215 | netlink_unlock_table(); |
4fdb3bb7 | 1216 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 1217 | netlink_lock_table(); |
4fdb3bb7 | 1218 | } |
ab33a171 PM |
1219 | #endif |
1220 | if (nl_table[protocol].registered && | |
1221 | try_module_get(nl_table[protocol].module)) | |
1222 | module = nl_table[protocol].module; | |
974c37e9 AD |
1223 | else |
1224 | err = -EPROTONOSUPPORT; | |
af65bdfc | 1225 | cb_mutex = nl_table[protocol].cb_mutex; |
03292745 | 1226 | bind = nl_table[protocol].bind; |
77247bbb | 1227 | netlink_unlock_table(); |
4fdb3bb7 | 1228 | |
974c37e9 AD |
1229 | if (err < 0) |
1230 | goto out; | |
1231 | ||
6ac552fd PM |
1232 | err = __netlink_create(net, sock, cb_mutex, protocol); |
1233 | if (err < 0) | |
f7fa9b10 PM |
1234 | goto out_module; |
1235 | ||
6f756a8c | 1236 | local_bh_disable(); |
c1fd3b94 | 1237 | sock_prot_inuse_add(net, &netlink_proto, 1); |
6f756a8c DM |
1238 | local_bh_enable(); |
1239 | ||
f7fa9b10 | 1240 | nlk = nlk_sk(sock->sk); |
f7fa9b10 | 1241 | nlk->module = module; |
03292745 | 1242 | nlk->netlink_bind = bind; |
ab33a171 PM |
1243 | out: |
1244 | return err; | |
1da177e4 | 1245 | |
ab33a171 PM |
1246 | out_module: |
1247 | module_put(module); | |
1248 | goto out; | |
1da177e4 LT |
1249 | } |
1250 | ||
1251 | static int netlink_release(struct socket *sock) | |
1252 | { | |
1253 | struct sock *sk = sock->sk; | |
1254 | struct netlink_sock *nlk; | |
1255 | ||
1256 | if (!sk) | |
1257 | return 0; | |
1258 | ||
1259 | netlink_remove(sk); | |
ac57b3a9 | 1260 | sock_orphan(sk); |
1da177e4 LT |
1261 | nlk = nlk_sk(sk); |
1262 | ||
3f660d66 HX |
1263 | /* |
1264 | * OK. Socket is unlinked, any packets that arrive now | |
1265 | * will be purged. | |
1266 | */ | |
1da177e4 | 1267 | |
1da177e4 LT |
1268 | sock->sk = NULL; |
1269 | wake_up_interruptible_all(&nlk->wait); | |
1270 | ||
1271 | skb_queue_purge(&sk->sk_write_queue); | |
1272 | ||
15e47304 | 1273 | if (nlk->portid) { |
1da177e4 | 1274 | struct netlink_notify n = { |
3b1e0a65 | 1275 | .net = sock_net(sk), |
1da177e4 | 1276 | .protocol = sk->sk_protocol, |
15e47304 | 1277 | .portid = nlk->portid, |
1da177e4 | 1278 | }; |
e041c683 AS |
1279 | atomic_notifier_call_chain(&netlink_chain, |
1280 | NETLINK_URELEASE, &n); | |
746fac4d | 1281 | } |
4fdb3bb7 | 1282 | |
5e7c001c | 1283 | module_put(nlk->module); |
4fdb3bb7 | 1284 | |
4277a083 | 1285 | netlink_table_grab(); |
aed81560 | 1286 | if (netlink_is_kernel(sk)) { |
869e58f8 DL |
1287 | BUG_ON(nl_table[sk->sk_protocol].registered == 0); |
1288 | if (--nl_table[sk->sk_protocol].registered == 0) { | |
6d772ac5 ED |
1289 | struct listeners *old; |
1290 | ||
1291 | old = nl_deref_protected(nl_table[sk->sk_protocol].listeners); | |
1292 | RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL); | |
1293 | kfree_rcu(old, rcu); | |
869e58f8 | 1294 | nl_table[sk->sk_protocol].module = NULL; |
9785e10a PNA |
1295 | nl_table[sk->sk_protocol].bind = NULL; |
1296 | nl_table[sk->sk_protocol].flags = 0; | |
869e58f8 DL |
1297 | nl_table[sk->sk_protocol].registered = 0; |
1298 | } | |
658cb354 | 1299 | } else if (nlk->subscriptions) { |
4277a083 | 1300 | netlink_update_listeners(sk); |
658cb354 | 1301 | } |
4277a083 | 1302 | netlink_table_ungrab(); |
77247bbb | 1303 | |
f7fa9b10 PM |
1304 | kfree(nlk->groups); |
1305 | nlk->groups = NULL; | |
1306 | ||
3755810c | 1307 | local_bh_disable(); |
c1fd3b94 | 1308 | sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); |
3755810c | 1309 | local_bh_enable(); |
1da177e4 LT |
1310 | sock_put(sk); |
1311 | return 0; | |
1312 | } | |
1313 | ||
1314 | static int netlink_autobind(struct socket *sock) | |
1315 | { | |
1316 | struct sock *sk = sock->sk; | |
3b1e0a65 | 1317 | struct net *net = sock_net(sk); |
da12c90e G |
1318 | struct netlink_table *table = &nl_table[sk->sk_protocol]; |
1319 | struct nl_portid_hash *hash = &table->hash; | |
1da177e4 LT |
1320 | struct hlist_head *head; |
1321 | struct sock *osk; | |
15e47304 | 1322 | s32 portid = task_tgid_vnr(current); |
1da177e4 LT |
1323 | int err; |
1324 | static s32 rover = -4097; | |
1325 | ||
1326 | retry: | |
1327 | cond_resched(); | |
1328 | netlink_table_grab(); | |
15e47304 | 1329 | head = nl_portid_hashfn(hash, portid); |
b67bfe0d | 1330 | sk_for_each(osk, head) { |
da12c90e | 1331 | if (!table->compare(net, osk)) |
b4b51029 | 1332 | continue; |
15e47304 EB |
1333 | if (nlk_sk(osk)->portid == portid) { |
1334 | /* Bind collision, search negative portid values. */ | |
1335 | portid = rover--; | |
1da177e4 LT |
1336 | if (rover > -4097) |
1337 | rover = -4097; | |
1338 | netlink_table_ungrab(); | |
1339 | goto retry; | |
1340 | } | |
1341 | } | |
1342 | netlink_table_ungrab(); | |
1343 | ||
15e47304 | 1344 | err = netlink_insert(sk, net, portid); |
1da177e4 LT |
1345 | if (err == -EADDRINUSE) |
1346 | goto retry; | |
d470e3b4 DM |
1347 | |
1348 | /* If 2 threads race to autobind, that is fine. */ | |
1349 | if (err == -EBUSY) | |
1350 | err = 0; | |
1351 | ||
1352 | return err; | |
1da177e4 LT |
1353 | } |
1354 | ||
b57ef81f | 1355 | static inline int netlink_capable(const struct socket *sock, unsigned int flag) |
746fac4d | 1356 | { |
9785e10a | 1357 | return (nl_table[sock->sk->sk_protocol].flags & flag) || |
df008c91 | 1358 | ns_capable(sock_net(sock->sk)->user_ns, CAP_NET_ADMIN); |
746fac4d | 1359 | } |
1da177e4 | 1360 | |
f7fa9b10 PM |
1361 | static void |
1362 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
1363 | { | |
1364 | struct netlink_sock *nlk = nlk_sk(sk); | |
1365 | ||
1366 | if (nlk->subscriptions && !subscriptions) | |
1367 | __sk_del_bind_node(sk); | |
1368 | else if (!nlk->subscriptions && subscriptions) | |
1369 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
1370 | nlk->subscriptions = subscriptions; | |
1371 | } | |
1372 | ||
b4ff4f04 | 1373 | static int netlink_realloc_groups(struct sock *sk) |
513c2500 PM |
1374 | { |
1375 | struct netlink_sock *nlk = nlk_sk(sk); | |
1376 | unsigned int groups; | |
b4ff4f04 | 1377 | unsigned long *new_groups; |
513c2500 PM |
1378 | int err = 0; |
1379 | ||
b4ff4f04 JB |
1380 | netlink_table_grab(); |
1381 | ||
513c2500 | 1382 | groups = nl_table[sk->sk_protocol].groups; |
b4ff4f04 | 1383 | if (!nl_table[sk->sk_protocol].registered) { |
513c2500 | 1384 | err = -ENOENT; |
b4ff4f04 JB |
1385 | goto out_unlock; |
1386 | } | |
513c2500 | 1387 | |
b4ff4f04 JB |
1388 | if (nlk->ngroups >= groups) |
1389 | goto out_unlock; | |
513c2500 | 1390 | |
b4ff4f04 JB |
1391 | new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
1392 | if (new_groups == NULL) { | |
1393 | err = -ENOMEM; | |
1394 | goto out_unlock; | |
1395 | } | |
6ac552fd | 1396 | memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, |
b4ff4f04 JB |
1397 | NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); |
1398 | ||
1399 | nlk->groups = new_groups; | |
513c2500 | 1400 | nlk->ngroups = groups; |
b4ff4f04 JB |
1401 | out_unlock: |
1402 | netlink_table_ungrab(); | |
1403 | return err; | |
513c2500 PM |
1404 | } |
1405 | ||
6ac552fd PM |
1406 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, |
1407 | int addr_len) | |
1da177e4 LT |
1408 | { |
1409 | struct sock *sk = sock->sk; | |
3b1e0a65 | 1410 | struct net *net = sock_net(sk); |
1da177e4 LT |
1411 | struct netlink_sock *nlk = nlk_sk(sk); |
1412 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
1413 | int err; | |
746fac4d | 1414 | |
4e4b5376 HFS |
1415 | if (addr_len < sizeof(struct sockaddr_nl)) |
1416 | return -EINVAL; | |
1417 | ||
1da177e4 LT |
1418 | if (nladdr->nl_family != AF_NETLINK) |
1419 | return -EINVAL; | |
1420 | ||
1421 | /* Only superuser is allowed to listen multicasts */ | |
513c2500 | 1422 | if (nladdr->nl_groups) { |
9785e10a | 1423 | if (!netlink_capable(sock, NL_CFG_F_NONROOT_RECV)) |
513c2500 | 1424 | return -EPERM; |
b4ff4f04 JB |
1425 | err = netlink_realloc_groups(sk); |
1426 | if (err) | |
1427 | return err; | |
513c2500 | 1428 | } |
1da177e4 | 1429 | |
15e47304 EB |
1430 | if (nlk->portid) { |
1431 | if (nladdr->nl_pid != nlk->portid) | |
1da177e4 LT |
1432 | return -EINVAL; |
1433 | } else { | |
1434 | err = nladdr->nl_pid ? | |
b4b51029 | 1435 | netlink_insert(sk, net, nladdr->nl_pid) : |
1da177e4 LT |
1436 | netlink_autobind(sock); |
1437 | if (err) | |
1438 | return err; | |
1439 | } | |
1440 | ||
513c2500 | 1441 | if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
1da177e4 LT |
1442 | return 0; |
1443 | ||
1444 | netlink_table_grab(); | |
f7fa9b10 | 1445 | netlink_update_subscriptions(sk, nlk->subscriptions + |
746fac4d YH |
1446 | hweight32(nladdr->nl_groups) - |
1447 | hweight32(nlk->groups[0])); | |
1448 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups; | |
4277a083 | 1449 | netlink_update_listeners(sk); |
1da177e4 LT |
1450 | netlink_table_ungrab(); |
1451 | ||
03292745 PNA |
1452 | if (nlk->netlink_bind && nlk->groups[0]) { |
1453 | int i; | |
1454 | ||
1455 | for (i=0; i<nlk->ngroups; i++) { | |
1456 | if (test_bit(i, nlk->groups)) | |
1457 | nlk->netlink_bind(i); | |
1458 | } | |
1459 | } | |
1460 | ||
1da177e4 LT |
1461 | return 0; |
1462 | } | |
1463 | ||
1464 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
1465 | int alen, int flags) | |
1466 | { | |
1467 | int err = 0; | |
1468 | struct sock *sk = sock->sk; | |
1469 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 1470 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
1da177e4 | 1471 | |
6503d961 CG |
1472 | if (alen < sizeof(addr->sa_family)) |
1473 | return -EINVAL; | |
1474 | ||
1da177e4 LT |
1475 | if (addr->sa_family == AF_UNSPEC) { |
1476 | sk->sk_state = NETLINK_UNCONNECTED; | |
15e47304 | 1477 | nlk->dst_portid = 0; |
d629b836 | 1478 | nlk->dst_group = 0; |
1da177e4 LT |
1479 | return 0; |
1480 | } | |
1481 | if (addr->sa_family != AF_NETLINK) | |
1482 | return -EINVAL; | |
1483 | ||
1484 | /* Only superuser is allowed to send multicasts */ | |
9785e10a | 1485 | if (nladdr->nl_groups && !netlink_capable(sock, NL_CFG_F_NONROOT_SEND)) |
1da177e4 LT |
1486 | return -EPERM; |
1487 | ||
15e47304 | 1488 | if (!nlk->portid) |
1da177e4 LT |
1489 | err = netlink_autobind(sock); |
1490 | ||
1491 | if (err == 0) { | |
1492 | sk->sk_state = NETLINK_CONNECTED; | |
15e47304 | 1493 | nlk->dst_portid = nladdr->nl_pid; |
d629b836 | 1494 | nlk->dst_group = ffs(nladdr->nl_groups); |
1da177e4 LT |
1495 | } |
1496 | ||
1497 | return err; | |
1498 | } | |
1499 | ||
6ac552fd PM |
1500 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, |
1501 | int *addr_len, int peer) | |
1da177e4 LT |
1502 | { |
1503 | struct sock *sk = sock->sk; | |
1504 | struct netlink_sock *nlk = nlk_sk(sk); | |
13cfa97b | 1505 | DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr); |
746fac4d | 1506 | |
1da177e4 LT |
1507 | nladdr->nl_family = AF_NETLINK; |
1508 | nladdr->nl_pad = 0; | |
1509 | *addr_len = sizeof(*nladdr); | |
1510 | ||
1511 | if (peer) { | |
15e47304 | 1512 | nladdr->nl_pid = nlk->dst_portid; |
d629b836 | 1513 | nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
1da177e4 | 1514 | } else { |
15e47304 | 1515 | nladdr->nl_pid = nlk->portid; |
513c2500 | 1516 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
1da177e4 LT |
1517 | } |
1518 | return 0; | |
1519 | } | |
1520 | ||
15e47304 | 1521 | static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid) |
1da177e4 | 1522 | { |
1da177e4 LT |
1523 | struct sock *sock; |
1524 | struct netlink_sock *nlk; | |
1525 | ||
15e47304 | 1526 | sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, portid); |
1da177e4 LT |
1527 | if (!sock) |
1528 | return ERR_PTR(-ECONNREFUSED); | |
1529 | ||
1530 | /* Don't bother queuing skb if kernel socket has no input function */ | |
1531 | nlk = nlk_sk(sock); | |
cd40b7d3 | 1532 | if (sock->sk_state == NETLINK_CONNECTED && |
15e47304 | 1533 | nlk->dst_portid != nlk_sk(ssk)->portid) { |
1da177e4 LT |
1534 | sock_put(sock); |
1535 | return ERR_PTR(-ECONNREFUSED); | |
1536 | } | |
1537 | return sock; | |
1538 | } | |
1539 | ||
1540 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
1541 | { | |
496ad9aa | 1542 | struct inode *inode = file_inode(filp); |
1da177e4 LT |
1543 | struct sock *sock; |
1544 | ||
1545 | if (!S_ISSOCK(inode->i_mode)) | |
1546 | return ERR_PTR(-ENOTSOCK); | |
1547 | ||
1548 | sock = SOCKET_I(inode)->sk; | |
1549 | if (sock->sk_family != AF_NETLINK) | |
1550 | return ERR_PTR(-EINVAL); | |
1551 | ||
1552 | sock_hold(sock); | |
1553 | return sock; | |
1554 | } | |
1555 | ||
3a36515f PN |
1556 | static struct sk_buff *netlink_alloc_large_skb(unsigned int size, |
1557 | int broadcast) | |
c05cdb1b PNA |
1558 | { |
1559 | struct sk_buff *skb; | |
1560 | void *data; | |
1561 | ||
3a36515f | 1562 | if (size <= NLMSG_GOODSIZE || broadcast) |
c05cdb1b PNA |
1563 | return alloc_skb(size, GFP_KERNEL); |
1564 | ||
3a36515f PN |
1565 | size = SKB_DATA_ALIGN(size) + |
1566 | SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); | |
c05cdb1b PNA |
1567 | |
1568 | data = vmalloc(size); | |
1569 | if (data == NULL) | |
3a36515f | 1570 | return NULL; |
c05cdb1b | 1571 | |
3a36515f PN |
1572 | skb = build_skb(data, size); |
1573 | if (skb == NULL) | |
1574 | vfree(data); | |
1575 | else { | |
1576 | skb->head_frag = 0; | |
1577 | skb->destructor = netlink_skb_destructor; | |
1578 | } | |
c05cdb1b PNA |
1579 | |
1580 | return skb; | |
c05cdb1b PNA |
1581 | } |
1582 | ||
1da177e4 LT |
1583 | /* |
1584 | * Attach a skb to a netlink socket. | |
1585 | * The caller must hold a reference to the destination socket. On error, the | |
1586 | * reference is dropped. The skb is not send to the destination, just all | |
1587 | * all error checks are performed and memory in the queue is reserved. | |
1588 | * Return values: | |
1589 | * < 0: error. skb freed, reference to sock dropped. | |
1590 | * 0: continue | |
1591 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
1592 | */ | |
9457afee | 1593 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
c3d8d1e3 | 1594 | long *timeo, struct sock *ssk) |
1da177e4 LT |
1595 | { |
1596 | struct netlink_sock *nlk; | |
1597 | ||
1598 | nlk = nlk_sk(sk); | |
1599 | ||
5fd96123 PM |
1600 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || |
1601 | test_bit(NETLINK_CONGESTED, &nlk->state)) && | |
1602 | !netlink_skb_is_mmaped(skb)) { | |
1da177e4 | 1603 | DECLARE_WAITQUEUE(wait, current); |
c3d8d1e3 | 1604 | if (!*timeo) { |
aed81560 | 1605 | if (!ssk || netlink_is_kernel(ssk)) |
1da177e4 LT |
1606 | netlink_overrun(sk); |
1607 | sock_put(sk); | |
1608 | kfree_skb(skb); | |
1609 | return -EAGAIN; | |
1610 | } | |
1611 | ||
1612 | __set_current_state(TASK_INTERRUPTIBLE); | |
1613 | add_wait_queue(&nlk->wait, &wait); | |
1614 | ||
1615 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
cd967e05 | 1616 | test_bit(NETLINK_CONGESTED, &nlk->state)) && |
1da177e4 | 1617 | !sock_flag(sk, SOCK_DEAD)) |
c3d8d1e3 | 1618 | *timeo = schedule_timeout(*timeo); |
1da177e4 LT |
1619 | |
1620 | __set_current_state(TASK_RUNNING); | |
1621 | remove_wait_queue(&nlk->wait, &wait); | |
1622 | sock_put(sk); | |
1623 | ||
1624 | if (signal_pending(current)) { | |
1625 | kfree_skb(skb); | |
c3d8d1e3 | 1626 | return sock_intr_errno(*timeo); |
1da177e4 LT |
1627 | } |
1628 | return 1; | |
1629 | } | |
cf0a018a | 1630 | netlink_skb_set_owner_r(skb, sk); |
1da177e4 LT |
1631 | return 0; |
1632 | } | |
1633 | ||
4a7e7c2a | 1634 | static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 1635 | { |
1da177e4 LT |
1636 | int len = skb->len; |
1637 | ||
bcbde0d4 DB |
1638 | netlink_deliver_tap(skb); |
1639 | ||
f9c22888 PM |
1640 | #ifdef CONFIG_NETLINK_MMAP |
1641 | if (netlink_skb_is_mmaped(skb)) | |
1642 | netlink_queue_mmaped_skb(sk, skb); | |
1643 | else if (netlink_rx_is_mmaped(sk)) | |
1644 | netlink_ring_set_copied(sk, skb); | |
1645 | else | |
1646 | #endif /* CONFIG_NETLINK_MMAP */ | |
1647 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
1da177e4 | 1648 | sk->sk_data_ready(sk, len); |
4a7e7c2a ED |
1649 | return len; |
1650 | } | |
1651 | ||
1652 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb) | |
1653 | { | |
1654 | int len = __netlink_sendskb(sk, skb); | |
1655 | ||
1da177e4 LT |
1656 | sock_put(sk); |
1657 | return len; | |
1658 | } | |
1659 | ||
1660 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
1661 | { | |
1662 | kfree_skb(skb); | |
1663 | sock_put(sk); | |
1664 | } | |
1665 | ||
b57ef81f | 1666 | static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation) |
1da177e4 LT |
1667 | { |
1668 | int delta; | |
1669 | ||
1298ca46 | 1670 | WARN_ON(skb->sk != NULL); |
5fd96123 PM |
1671 | if (netlink_skb_is_mmaped(skb)) |
1672 | return skb; | |
1da177e4 | 1673 | |
4305b541 | 1674 | delta = skb->end - skb->tail; |
c05cdb1b | 1675 | if (is_vmalloc_addr(skb->head) || delta * 2 < skb->truesize) |
1da177e4 LT |
1676 | return skb; |
1677 | ||
1678 | if (skb_shared(skb)) { | |
1679 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
1680 | if (!nskb) | |
1681 | return skb; | |
8460c00f | 1682 | consume_skb(skb); |
1da177e4 LT |
1683 | skb = nskb; |
1684 | } | |
1685 | ||
1686 | if (!pskb_expand_head(skb, 0, -delta, allocation)) | |
1687 | skb->truesize -= delta; | |
1688 | ||
1689 | return skb; | |
1690 | } | |
1691 | ||
3fbc2905 EB |
1692 | static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb, |
1693 | struct sock *ssk) | |
cd40b7d3 DL |
1694 | { |
1695 | int ret; | |
1696 | struct netlink_sock *nlk = nlk_sk(sk); | |
1697 | ||
1698 | ret = -ECONNREFUSED; | |
1699 | if (nlk->netlink_rcv != NULL) { | |
bcbde0d4 DB |
1700 | /* We could do a netlink_deliver_tap(skb) here as well |
1701 | * but since this is intended for the kernel only, we | |
1702 | * should rather let it stay under the hood. | |
1703 | */ | |
1704 | ||
cd40b7d3 | 1705 | ret = skb->len; |
cf0a018a | 1706 | netlink_skb_set_owner_r(skb, sk); |
e32123e5 | 1707 | NETLINK_CB(skb).sk = ssk; |
cd40b7d3 | 1708 | nlk->netlink_rcv(skb); |
bfb253c9 ED |
1709 | consume_skb(skb); |
1710 | } else { | |
1711 | kfree_skb(skb); | |
cd40b7d3 | 1712 | } |
cd40b7d3 DL |
1713 | sock_put(sk); |
1714 | return ret; | |
1715 | } | |
1716 | ||
1717 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, | |
15e47304 | 1718 | u32 portid, int nonblock) |
1da177e4 LT |
1719 | { |
1720 | struct sock *sk; | |
1721 | int err; | |
1722 | long timeo; | |
1723 | ||
1724 | skb = netlink_trim(skb, gfp_any()); | |
1725 | ||
1726 | timeo = sock_sndtimeo(ssk, nonblock); | |
1727 | retry: | |
15e47304 | 1728 | sk = netlink_getsockbyportid(ssk, portid); |
1da177e4 LT |
1729 | if (IS_ERR(sk)) { |
1730 | kfree_skb(skb); | |
1731 | return PTR_ERR(sk); | |
1732 | } | |
cd40b7d3 | 1733 | if (netlink_is_kernel(sk)) |
3fbc2905 | 1734 | return netlink_unicast_kernel(sk, skb, ssk); |
cd40b7d3 | 1735 | |
b1153f29 | 1736 | if (sk_filter(sk, skb)) { |
84874607 | 1737 | err = skb->len; |
b1153f29 SH |
1738 | kfree_skb(skb); |
1739 | sock_put(sk); | |
1740 | return err; | |
1741 | } | |
1742 | ||
9457afee | 1743 | err = netlink_attachskb(sk, skb, &timeo, ssk); |
1da177e4 LT |
1744 | if (err == 1) |
1745 | goto retry; | |
1746 | if (err) | |
1747 | return err; | |
1748 | ||
7ee015e0 | 1749 | return netlink_sendskb(sk, skb); |
1da177e4 | 1750 | } |
6ac552fd | 1751 | EXPORT_SYMBOL(netlink_unicast); |
1da177e4 | 1752 | |
f9c22888 PM |
1753 | struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size, |
1754 | u32 dst_portid, gfp_t gfp_mask) | |
1755 | { | |
1756 | #ifdef CONFIG_NETLINK_MMAP | |
1757 | struct sock *sk = NULL; | |
1758 | struct sk_buff *skb; | |
1759 | struct netlink_ring *ring; | |
1760 | struct nl_mmap_hdr *hdr; | |
1761 | unsigned int maxlen; | |
1762 | ||
1763 | sk = netlink_getsockbyportid(ssk, dst_portid); | |
1764 | if (IS_ERR(sk)) | |
1765 | goto out; | |
1766 | ||
1767 | ring = &nlk_sk(sk)->rx_ring; | |
1768 | /* fast-path without atomic ops for common case: non-mmaped receiver */ | |
1769 | if (ring->pg_vec == NULL) | |
1770 | goto out_put; | |
1771 | ||
1772 | skb = alloc_skb_head(gfp_mask); | |
1773 | if (skb == NULL) | |
1774 | goto err1; | |
1775 | ||
1776 | spin_lock_bh(&sk->sk_receive_queue.lock); | |
1777 | /* check again under lock */ | |
1778 | if (ring->pg_vec == NULL) | |
1779 | goto out_free; | |
1780 | ||
1781 | maxlen = ring->frame_size - NL_MMAP_HDRLEN; | |
1782 | if (maxlen < size) | |
1783 | goto out_free; | |
1784 | ||
1785 | netlink_forward_ring(ring); | |
1786 | hdr = netlink_current_frame(ring, NL_MMAP_STATUS_UNUSED); | |
1787 | if (hdr == NULL) | |
1788 | goto err2; | |
1789 | netlink_ring_setup_skb(skb, sk, ring, hdr); | |
1790 | netlink_set_status(hdr, NL_MMAP_STATUS_RESERVED); | |
1791 | atomic_inc(&ring->pending); | |
1792 | netlink_increment_head(ring); | |
1793 | ||
1794 | spin_unlock_bh(&sk->sk_receive_queue.lock); | |
1795 | return skb; | |
1796 | ||
1797 | err2: | |
1798 | kfree_skb(skb); | |
1799 | spin_unlock_bh(&sk->sk_receive_queue.lock); | |
cd1df525 | 1800 | netlink_overrun(sk); |
f9c22888 PM |
1801 | err1: |
1802 | sock_put(sk); | |
1803 | return NULL; | |
1804 | ||
1805 | out_free: | |
1806 | kfree_skb(skb); | |
1807 | spin_unlock_bh(&sk->sk_receive_queue.lock); | |
1808 | out_put: | |
1809 | sock_put(sk); | |
1810 | out: | |
1811 | #endif | |
1812 | return alloc_skb(size, gfp_mask); | |
1813 | } | |
1814 | EXPORT_SYMBOL_GPL(netlink_alloc_skb); | |
1815 | ||
4277a083 PM |
1816 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
1817 | { | |
1818 | int res = 0; | |
5c398dc8 | 1819 | struct listeners *listeners; |
4277a083 | 1820 | |
aed81560 | 1821 | BUG_ON(!netlink_is_kernel(sk)); |
b4ff4f04 JB |
1822 | |
1823 | rcu_read_lock(); | |
1824 | listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); | |
1825 | ||
6d772ac5 | 1826 | if (listeners && group - 1 < nl_table[sk->sk_protocol].groups) |
5c398dc8 | 1827 | res = test_bit(group - 1, listeners->masks); |
b4ff4f04 JB |
1828 | |
1829 | rcu_read_unlock(); | |
1830 | ||
4277a083 PM |
1831 | return res; |
1832 | } | |
1833 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
1834 | ||
b57ef81f | 1835 | static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) |
1da177e4 LT |
1836 | { |
1837 | struct netlink_sock *nlk = nlk_sk(sk); | |
1838 | ||
1839 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
cd967e05 | 1840 | !test_bit(NETLINK_CONGESTED, &nlk->state)) { |
cf0a018a | 1841 | netlink_skb_set_owner_r(skb, sk); |
4a7e7c2a | 1842 | __netlink_sendskb(sk, skb); |
2c645800 | 1843 | return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1); |
1da177e4 LT |
1844 | } |
1845 | return -1; | |
1846 | } | |
1847 | ||
1848 | struct netlink_broadcast_data { | |
1849 | struct sock *exclude_sk; | |
b4b51029 | 1850 | struct net *net; |
15e47304 | 1851 | u32 portid; |
1da177e4 LT |
1852 | u32 group; |
1853 | int failure; | |
ff491a73 | 1854 | int delivery_failure; |
1da177e4 LT |
1855 | int congested; |
1856 | int delivered; | |
7d877f3b | 1857 | gfp_t allocation; |
1da177e4 | 1858 | struct sk_buff *skb, *skb2; |
910a7e90 EB |
1859 | int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data); |
1860 | void *tx_data; | |
1da177e4 LT |
1861 | }; |
1862 | ||
b57ef81f | 1863 | static int do_one_broadcast(struct sock *sk, |
1da177e4 LT |
1864 | struct netlink_broadcast_data *p) |
1865 | { | |
1866 | struct netlink_sock *nlk = nlk_sk(sk); | |
1867 | int val; | |
1868 | ||
1869 | if (p->exclude_sk == sk) | |
1870 | goto out; | |
1871 | ||
15e47304 | 1872 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
f7fa9b10 | 1873 | !test_bit(p->group - 1, nlk->groups)) |
1da177e4 LT |
1874 | goto out; |
1875 | ||
878628fb | 1876 | if (!net_eq(sock_net(sk), p->net)) |
b4b51029 EB |
1877 | goto out; |
1878 | ||
1da177e4 LT |
1879 | if (p->failure) { |
1880 | netlink_overrun(sk); | |
1881 | goto out; | |
1882 | } | |
1883 | ||
1884 | sock_hold(sk); | |
1885 | if (p->skb2 == NULL) { | |
68acc024 | 1886 | if (skb_shared(p->skb)) { |
1da177e4 LT |
1887 | p->skb2 = skb_clone(p->skb, p->allocation); |
1888 | } else { | |
68acc024 TC |
1889 | p->skb2 = skb_get(p->skb); |
1890 | /* | |
1891 | * skb ownership may have been set when | |
1892 | * delivered to a previous socket. | |
1893 | */ | |
1894 | skb_orphan(p->skb2); | |
1da177e4 LT |
1895 | } |
1896 | } | |
1897 | if (p->skb2 == NULL) { | |
1898 | netlink_overrun(sk); | |
1899 | /* Clone failed. Notify ALL listeners. */ | |
1900 | p->failure = 1; | |
be0c22a4 PNA |
1901 | if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) |
1902 | p->delivery_failure = 1; | |
910a7e90 EB |
1903 | } else if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) { |
1904 | kfree_skb(p->skb2); | |
1905 | p->skb2 = NULL; | |
b1153f29 SH |
1906 | } else if (sk_filter(sk, p->skb2)) { |
1907 | kfree_skb(p->skb2); | |
1908 | p->skb2 = NULL; | |
1da177e4 LT |
1909 | } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) { |
1910 | netlink_overrun(sk); | |
be0c22a4 PNA |
1911 | if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) |
1912 | p->delivery_failure = 1; | |
1da177e4 LT |
1913 | } else { |
1914 | p->congested |= val; | |
1915 | p->delivered = 1; | |
1916 | p->skb2 = NULL; | |
1917 | } | |
1918 | sock_put(sk); | |
1919 | ||
1920 | out: | |
1921 | return 0; | |
1922 | } | |
1923 | ||
15e47304 | 1924 | int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 portid, |
910a7e90 EB |
1925 | u32 group, gfp_t allocation, |
1926 | int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data), | |
1927 | void *filter_data) | |
1da177e4 | 1928 | { |
3b1e0a65 | 1929 | struct net *net = sock_net(ssk); |
1da177e4 | 1930 | struct netlink_broadcast_data info; |
1da177e4 LT |
1931 | struct sock *sk; |
1932 | ||
1933 | skb = netlink_trim(skb, allocation); | |
1934 | ||
1935 | info.exclude_sk = ssk; | |
b4b51029 | 1936 | info.net = net; |
15e47304 | 1937 | info.portid = portid; |
1da177e4 LT |
1938 | info.group = group; |
1939 | info.failure = 0; | |
ff491a73 | 1940 | info.delivery_failure = 0; |
1da177e4 LT |
1941 | info.congested = 0; |
1942 | info.delivered = 0; | |
1943 | info.allocation = allocation; | |
1944 | info.skb = skb; | |
1945 | info.skb2 = NULL; | |
910a7e90 EB |
1946 | info.tx_filter = filter; |
1947 | info.tx_data = filter_data; | |
1da177e4 LT |
1948 | |
1949 | /* While we sleep in clone, do not allow to change socket list */ | |
1950 | ||
1951 | netlink_lock_table(); | |
1952 | ||
b67bfe0d | 1953 | sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
1da177e4 LT |
1954 | do_one_broadcast(sk, &info); |
1955 | ||
70d4bf6d | 1956 | consume_skb(skb); |
aa1c6a6f | 1957 | |
1da177e4 LT |
1958 | netlink_unlock_table(); |
1959 | ||
70d4bf6d NH |
1960 | if (info.delivery_failure) { |
1961 | kfree_skb(info.skb2); | |
ff491a73 | 1962 | return -ENOBUFS; |
658cb354 ED |
1963 | } |
1964 | consume_skb(info.skb2); | |
ff491a73 | 1965 | |
1da177e4 LT |
1966 | if (info.delivered) { |
1967 | if (info.congested && (allocation & __GFP_WAIT)) | |
1968 | yield(); | |
1969 | return 0; | |
1970 | } | |
1da177e4 LT |
1971 | return -ESRCH; |
1972 | } | |
910a7e90 EB |
1973 | EXPORT_SYMBOL(netlink_broadcast_filtered); |
1974 | ||
15e47304 | 1975 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 portid, |
910a7e90 EB |
1976 | u32 group, gfp_t allocation) |
1977 | { | |
15e47304 | 1978 | return netlink_broadcast_filtered(ssk, skb, portid, group, allocation, |
910a7e90 EB |
1979 | NULL, NULL); |
1980 | } | |
6ac552fd | 1981 | EXPORT_SYMBOL(netlink_broadcast); |
1da177e4 LT |
1982 | |
1983 | struct netlink_set_err_data { | |
1984 | struct sock *exclude_sk; | |
15e47304 | 1985 | u32 portid; |
1da177e4 LT |
1986 | u32 group; |
1987 | int code; | |
1988 | }; | |
1989 | ||
b57ef81f | 1990 | static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p) |
1da177e4 LT |
1991 | { |
1992 | struct netlink_sock *nlk = nlk_sk(sk); | |
1a50307b | 1993 | int ret = 0; |
1da177e4 LT |
1994 | |
1995 | if (sk == p->exclude_sk) | |
1996 | goto out; | |
1997 | ||
09ad9bc7 | 1998 | if (!net_eq(sock_net(sk), sock_net(p->exclude_sk))) |
b4b51029 EB |
1999 | goto out; |
2000 | ||
15e47304 | 2001 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
f7fa9b10 | 2002 | !test_bit(p->group - 1, nlk->groups)) |
1da177e4 LT |
2003 | goto out; |
2004 | ||
1a50307b PNA |
2005 | if (p->code == ENOBUFS && nlk->flags & NETLINK_RECV_NO_ENOBUFS) { |
2006 | ret = 1; | |
2007 | goto out; | |
2008 | } | |
2009 | ||
1da177e4 LT |
2010 | sk->sk_err = p->code; |
2011 | sk->sk_error_report(sk); | |
2012 | out: | |
1a50307b | 2013 | return ret; |
1da177e4 LT |
2014 | } |
2015 | ||
4843b93c PNA |
2016 | /** |
2017 | * netlink_set_err - report error to broadcast listeners | |
2018 | * @ssk: the kernel netlink socket, as returned by netlink_kernel_create() | |
15e47304 | 2019 | * @portid: the PORTID of a process that we want to skip (if any) |
840e93f2 | 2020 | * @group: the broadcast group that will notice the error |
4843b93c | 2021 | * @code: error code, must be negative (as usual in kernelspace) |
1a50307b PNA |
2022 | * |
2023 | * This function returns the number of broadcast listeners that have set the | |
2024 | * NETLINK_RECV_NO_ENOBUFS socket option. | |
4843b93c | 2025 | */ |
15e47304 | 2026 | int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code) |
1da177e4 LT |
2027 | { |
2028 | struct netlink_set_err_data info; | |
1da177e4 | 2029 | struct sock *sk; |
1a50307b | 2030 | int ret = 0; |
1da177e4 LT |
2031 | |
2032 | info.exclude_sk = ssk; | |
15e47304 | 2033 | info.portid = portid; |
1da177e4 | 2034 | info.group = group; |
4843b93c PNA |
2035 | /* sk->sk_err wants a positive error value */ |
2036 | info.code = -code; | |
1da177e4 LT |
2037 | |
2038 | read_lock(&nl_table_lock); | |
2039 | ||
b67bfe0d | 2040 | sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
1a50307b | 2041 | ret += do_one_set_err(sk, &info); |
1da177e4 LT |
2042 | |
2043 | read_unlock(&nl_table_lock); | |
1a50307b | 2044 | return ret; |
1da177e4 | 2045 | } |
dd5b6ce6 | 2046 | EXPORT_SYMBOL(netlink_set_err); |
1da177e4 | 2047 | |
84659eb5 JB |
2048 | /* must be called with netlink table grabbed */ |
2049 | static void netlink_update_socket_mc(struct netlink_sock *nlk, | |
2050 | unsigned int group, | |
2051 | int is_new) | |
2052 | { | |
2053 | int old, new = !!is_new, subscriptions; | |
2054 | ||
2055 | old = test_bit(group - 1, nlk->groups); | |
2056 | subscriptions = nlk->subscriptions - old + new; | |
2057 | if (new) | |
2058 | __set_bit(group - 1, nlk->groups); | |
2059 | else | |
2060 | __clear_bit(group - 1, nlk->groups); | |
2061 | netlink_update_subscriptions(&nlk->sk, subscriptions); | |
2062 | netlink_update_listeners(&nlk->sk); | |
2063 | } | |
2064 | ||
9a4595bc | 2065 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
b7058842 | 2066 | char __user *optval, unsigned int optlen) |
9a4595bc PM |
2067 | { |
2068 | struct sock *sk = sock->sk; | |
2069 | struct netlink_sock *nlk = nlk_sk(sk); | |
eb496534 JB |
2070 | unsigned int val = 0; |
2071 | int err; | |
9a4595bc PM |
2072 | |
2073 | if (level != SOL_NETLINK) | |
2074 | return -ENOPROTOOPT; | |
2075 | ||
ccdfcc39 PM |
2076 | if (optname != NETLINK_RX_RING && optname != NETLINK_TX_RING && |
2077 | optlen >= sizeof(int) && | |
eb496534 | 2078 | get_user(val, (unsigned int __user *)optval)) |
9a4595bc PM |
2079 | return -EFAULT; |
2080 | ||
2081 | switch (optname) { | |
2082 | case NETLINK_PKTINFO: | |
2083 | if (val) | |
2084 | nlk->flags |= NETLINK_RECV_PKTINFO; | |
2085 | else | |
2086 | nlk->flags &= ~NETLINK_RECV_PKTINFO; | |
2087 | err = 0; | |
2088 | break; | |
2089 | case NETLINK_ADD_MEMBERSHIP: | |
2090 | case NETLINK_DROP_MEMBERSHIP: { | |
9785e10a | 2091 | if (!netlink_capable(sock, NL_CFG_F_NONROOT_RECV)) |
9a4595bc | 2092 | return -EPERM; |
b4ff4f04 JB |
2093 | err = netlink_realloc_groups(sk); |
2094 | if (err) | |
2095 | return err; | |
9a4595bc PM |
2096 | if (!val || val - 1 >= nlk->ngroups) |
2097 | return -EINVAL; | |
2098 | netlink_table_grab(); | |
84659eb5 JB |
2099 | netlink_update_socket_mc(nlk, val, |
2100 | optname == NETLINK_ADD_MEMBERSHIP); | |
9a4595bc | 2101 | netlink_table_ungrab(); |
03292745 PNA |
2102 | |
2103 | if (nlk->netlink_bind) | |
2104 | nlk->netlink_bind(val); | |
2105 | ||
9a4595bc PM |
2106 | err = 0; |
2107 | break; | |
2108 | } | |
be0c22a4 PNA |
2109 | case NETLINK_BROADCAST_ERROR: |
2110 | if (val) | |
2111 | nlk->flags |= NETLINK_BROADCAST_SEND_ERROR; | |
2112 | else | |
2113 | nlk->flags &= ~NETLINK_BROADCAST_SEND_ERROR; | |
2114 | err = 0; | |
2115 | break; | |
38938bfe PNA |
2116 | case NETLINK_NO_ENOBUFS: |
2117 | if (val) { | |
2118 | nlk->flags |= NETLINK_RECV_NO_ENOBUFS; | |
cd967e05 | 2119 | clear_bit(NETLINK_CONGESTED, &nlk->state); |
38938bfe | 2120 | wake_up_interruptible(&nlk->wait); |
658cb354 | 2121 | } else { |
38938bfe | 2122 | nlk->flags &= ~NETLINK_RECV_NO_ENOBUFS; |
658cb354 | 2123 | } |
38938bfe PNA |
2124 | err = 0; |
2125 | break; | |
ccdfcc39 PM |
2126 | #ifdef CONFIG_NETLINK_MMAP |
2127 | case NETLINK_RX_RING: | |
2128 | case NETLINK_TX_RING: { | |
2129 | struct nl_mmap_req req; | |
2130 | ||
2131 | /* Rings might consume more memory than queue limits, require | |
2132 | * CAP_NET_ADMIN. | |
2133 | */ | |
2134 | if (!capable(CAP_NET_ADMIN)) | |
2135 | return -EPERM; | |
2136 | if (optlen < sizeof(req)) | |
2137 | return -EINVAL; | |
2138 | if (copy_from_user(&req, optval, sizeof(req))) | |
2139 | return -EFAULT; | |
2140 | err = netlink_set_ring(sk, &req, false, | |
2141 | optname == NETLINK_TX_RING); | |
2142 | break; | |
2143 | } | |
2144 | #endif /* CONFIG_NETLINK_MMAP */ | |
9a4595bc PM |
2145 | default: |
2146 | err = -ENOPROTOOPT; | |
2147 | } | |
2148 | return err; | |
2149 | } | |
2150 | ||
2151 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
746fac4d | 2152 | char __user *optval, int __user *optlen) |
9a4595bc PM |
2153 | { |
2154 | struct sock *sk = sock->sk; | |
2155 | struct netlink_sock *nlk = nlk_sk(sk); | |
2156 | int len, val, err; | |
2157 | ||
2158 | if (level != SOL_NETLINK) | |
2159 | return -ENOPROTOOPT; | |
2160 | ||
2161 | if (get_user(len, optlen)) | |
2162 | return -EFAULT; | |
2163 | if (len < 0) | |
2164 | return -EINVAL; | |
2165 | ||
2166 | switch (optname) { | |
2167 | case NETLINK_PKTINFO: | |
2168 | if (len < sizeof(int)) | |
2169 | return -EINVAL; | |
2170 | len = sizeof(int); | |
2171 | val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0; | |
a27b58fe HC |
2172 | if (put_user(len, optlen) || |
2173 | put_user(val, optval)) | |
2174 | return -EFAULT; | |
9a4595bc PM |
2175 | err = 0; |
2176 | break; | |
be0c22a4 PNA |
2177 | case NETLINK_BROADCAST_ERROR: |
2178 | if (len < sizeof(int)) | |
2179 | return -EINVAL; | |
2180 | len = sizeof(int); | |
2181 | val = nlk->flags & NETLINK_BROADCAST_SEND_ERROR ? 1 : 0; | |
2182 | if (put_user(len, optlen) || | |
2183 | put_user(val, optval)) | |
2184 | return -EFAULT; | |
2185 | err = 0; | |
2186 | break; | |
38938bfe PNA |
2187 | case NETLINK_NO_ENOBUFS: |
2188 | if (len < sizeof(int)) | |
2189 | return -EINVAL; | |
2190 | len = sizeof(int); | |
2191 | val = nlk->flags & NETLINK_RECV_NO_ENOBUFS ? 1 : 0; | |
2192 | if (put_user(len, optlen) || | |
2193 | put_user(val, optval)) | |
2194 | return -EFAULT; | |
2195 | err = 0; | |
2196 | break; | |
9a4595bc PM |
2197 | default: |
2198 | err = -ENOPROTOOPT; | |
2199 | } | |
2200 | return err; | |
2201 | } | |
2202 | ||
2203 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
2204 | { | |
2205 | struct nl_pktinfo info; | |
2206 | ||
2207 | info.group = NETLINK_CB(skb).dst_group; | |
2208 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
2209 | } | |
2210 | ||
1da177e4 LT |
2211 | static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, |
2212 | struct msghdr *msg, size_t len) | |
2213 | { | |
2214 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
2215 | struct sock *sk = sock->sk; | |
2216 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 2217 | struct sockaddr_nl *addr = msg->msg_name; |
15e47304 | 2218 | u32 dst_portid; |
d629b836 | 2219 | u32 dst_group; |
1da177e4 LT |
2220 | struct sk_buff *skb; |
2221 | int err; | |
2222 | struct scm_cookie scm; | |
2223 | ||
2224 | if (msg->msg_flags&MSG_OOB) | |
2225 | return -EOPNOTSUPP; | |
2226 | ||
16e57262 | 2227 | if (NULL == siocb->scm) |
1da177e4 | 2228 | siocb->scm = &scm; |
16e57262 | 2229 | |
e0e3cea4 | 2230 | err = scm_send(sock, msg, siocb->scm, true); |
1da177e4 LT |
2231 | if (err < 0) |
2232 | return err; | |
2233 | ||
2234 | if (msg->msg_namelen) { | |
b47030c7 | 2235 | err = -EINVAL; |
1da177e4 | 2236 | if (addr->nl_family != AF_NETLINK) |
b47030c7 | 2237 | goto out; |
15e47304 | 2238 | dst_portid = addr->nl_pid; |
d629b836 | 2239 | dst_group = ffs(addr->nl_groups); |
b47030c7 | 2240 | err = -EPERM; |
15e47304 | 2241 | if ((dst_group || dst_portid) && |
9785e10a | 2242 | !netlink_capable(sock, NL_CFG_F_NONROOT_SEND)) |
b47030c7 | 2243 | goto out; |
1da177e4 | 2244 | } else { |
15e47304 | 2245 | dst_portid = nlk->dst_portid; |
d629b836 | 2246 | dst_group = nlk->dst_group; |
1da177e4 LT |
2247 | } |
2248 | ||
15e47304 | 2249 | if (!nlk->portid) { |
1da177e4 LT |
2250 | err = netlink_autobind(sock); |
2251 | if (err) | |
2252 | goto out; | |
2253 | } | |
2254 | ||
5fd96123 PM |
2255 | if (netlink_tx_is_mmaped(sk) && |
2256 | msg->msg_iov->iov_base == NULL) { | |
2257 | err = netlink_mmap_sendmsg(sk, msg, dst_portid, dst_group, | |
2258 | siocb); | |
2259 | goto out; | |
2260 | } | |
2261 | ||
1da177e4 LT |
2262 | err = -EMSGSIZE; |
2263 | if (len > sk->sk_sndbuf - 32) | |
2264 | goto out; | |
2265 | err = -ENOBUFS; | |
3a36515f | 2266 | skb = netlink_alloc_large_skb(len, dst_group); |
6ac552fd | 2267 | if (skb == NULL) |
1da177e4 LT |
2268 | goto out; |
2269 | ||
15e47304 | 2270 | NETLINK_CB(skb).portid = nlk->portid; |
d629b836 | 2271 | NETLINK_CB(skb).dst_group = dst_group; |
dbe9a417 | 2272 | NETLINK_CB(skb).creds = siocb->scm->creds; |
1da177e4 | 2273 | |
1da177e4 | 2274 | err = -EFAULT; |
6ac552fd | 2275 | if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) { |
1da177e4 LT |
2276 | kfree_skb(skb); |
2277 | goto out; | |
2278 | } | |
2279 | ||
2280 | err = security_netlink_send(sk, skb); | |
2281 | if (err) { | |
2282 | kfree_skb(skb); | |
2283 | goto out; | |
2284 | } | |
2285 | ||
d629b836 | 2286 | if (dst_group) { |
1da177e4 | 2287 | atomic_inc(&skb->users); |
15e47304 | 2288 | netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL); |
1da177e4 | 2289 | } |
15e47304 | 2290 | err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags&MSG_DONTWAIT); |
1da177e4 LT |
2291 | |
2292 | out: | |
b47030c7 | 2293 | scm_destroy(siocb->scm); |
1da177e4 LT |
2294 | return err; |
2295 | } | |
2296 | ||
2297 | static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, | |
2298 | struct msghdr *msg, size_t len, | |
2299 | int flags) | |
2300 | { | |
2301 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
2302 | struct scm_cookie scm; | |
2303 | struct sock *sk = sock->sk; | |
2304 | struct netlink_sock *nlk = nlk_sk(sk); | |
2305 | int noblock = flags&MSG_DONTWAIT; | |
2306 | size_t copied; | |
68d6ac6d | 2307 | struct sk_buff *skb, *data_skb; |
b44d211e | 2308 | int err, ret; |
1da177e4 LT |
2309 | |
2310 | if (flags&MSG_OOB) | |
2311 | return -EOPNOTSUPP; | |
2312 | ||
2313 | copied = 0; | |
2314 | ||
6ac552fd PM |
2315 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
2316 | if (skb == NULL) | |
1da177e4 LT |
2317 | goto out; |
2318 | ||
68d6ac6d JB |
2319 | data_skb = skb; |
2320 | ||
1dacc76d JB |
2321 | #ifdef CONFIG_COMPAT_NETLINK_MESSAGES |
2322 | if (unlikely(skb_shinfo(skb)->frag_list)) { | |
1dacc76d | 2323 | /* |
68d6ac6d JB |
2324 | * If this skb has a frag_list, then here that means that we |
2325 | * will have to use the frag_list skb's data for compat tasks | |
2326 | * and the regular skb's data for normal (non-compat) tasks. | |
1dacc76d | 2327 | * |
68d6ac6d JB |
2328 | * If we need to send the compat skb, assign it to the |
2329 | * 'data_skb' variable so that it will be used below for data | |
2330 | * copying. We keep 'skb' for everything else, including | |
2331 | * freeing both later. | |
1dacc76d | 2332 | */ |
68d6ac6d JB |
2333 | if (flags & MSG_CMSG_COMPAT) |
2334 | data_skb = skb_shinfo(skb)->frag_list; | |
1dacc76d JB |
2335 | } |
2336 | #endif | |
2337 | ||
68d6ac6d | 2338 | copied = data_skb->len; |
1da177e4 LT |
2339 | if (len < copied) { |
2340 | msg->msg_flags |= MSG_TRUNC; | |
2341 | copied = len; | |
2342 | } | |
2343 | ||
68d6ac6d JB |
2344 | skb_reset_transport_header(data_skb); |
2345 | err = skb_copy_datagram_iovec(data_skb, 0, msg->msg_iov, copied); | |
1da177e4 LT |
2346 | |
2347 | if (msg->msg_name) { | |
6ac552fd | 2348 | struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name; |
1da177e4 LT |
2349 | addr->nl_family = AF_NETLINK; |
2350 | addr->nl_pad = 0; | |
15e47304 | 2351 | addr->nl_pid = NETLINK_CB(skb).portid; |
d629b836 | 2352 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
2353 | msg->msg_namelen = sizeof(*addr); |
2354 | } | |
2355 | ||
cc9a06cd PM |
2356 | if (nlk->flags & NETLINK_RECV_PKTINFO) |
2357 | netlink_cmsg_recv_pktinfo(msg, skb); | |
2358 | ||
1da177e4 LT |
2359 | if (NULL == siocb->scm) { |
2360 | memset(&scm, 0, sizeof(scm)); | |
2361 | siocb->scm = &scm; | |
2362 | } | |
2363 | siocb->scm->creds = *NETLINK_CREDS(skb); | |
188ccb55 | 2364 | if (flags & MSG_TRUNC) |
68d6ac6d | 2365 | copied = data_skb->len; |
daa3766e | 2366 | |
1da177e4 LT |
2367 | skb_free_datagram(sk, skb); |
2368 | ||
16b304f3 PS |
2369 | if (nlk->cb_running && |
2370 | atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) { | |
b44d211e AV |
2371 | ret = netlink_dump(sk); |
2372 | if (ret) { | |
2373 | sk->sk_err = ret; | |
2374 | sk->sk_error_report(sk); | |
2375 | } | |
2376 | } | |
1da177e4 LT |
2377 | |
2378 | scm_recv(sock, msg, siocb->scm, flags); | |
1da177e4 LT |
2379 | out: |
2380 | netlink_rcv_wake(sk); | |
2381 | return err ? : copied; | |
2382 | } | |
2383 | ||
2384 | static void netlink_data_ready(struct sock *sk, int len) | |
2385 | { | |
cd40b7d3 | 2386 | BUG(); |
1da177e4 LT |
2387 | } |
2388 | ||
2389 | /* | |
746fac4d | 2390 | * We export these functions to other modules. They provide a |
1da177e4 LT |
2391 | * complete set of kernel non-blocking support for message |
2392 | * queueing. | |
2393 | */ | |
2394 | ||
2395 | struct sock * | |
9f00d977 PNA |
2396 | __netlink_kernel_create(struct net *net, int unit, struct module *module, |
2397 | struct netlink_kernel_cfg *cfg) | |
1da177e4 LT |
2398 | { |
2399 | struct socket *sock; | |
2400 | struct sock *sk; | |
77247bbb | 2401 | struct netlink_sock *nlk; |
5c398dc8 | 2402 | struct listeners *listeners = NULL; |
a31f2d17 PNA |
2403 | struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL; |
2404 | unsigned int groups; | |
1da177e4 | 2405 | |
fab2caf6 | 2406 | BUG_ON(!nl_table); |
1da177e4 | 2407 | |
6ac552fd | 2408 | if (unit < 0 || unit >= MAX_LINKS) |
1da177e4 LT |
2409 | return NULL; |
2410 | ||
2411 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
2412 | return NULL; | |
2413 | ||
23fe1866 PE |
2414 | /* |
2415 | * We have to just have a reference on the net from sk, but don't | |
2416 | * get_net it. Besides, we cannot get and then put the net here. | |
2417 | * So we create one inside init_net and the move it to net. | |
2418 | */ | |
2419 | ||
2420 | if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0) | |
2421 | goto out_sock_release_nosk; | |
2422 | ||
2423 | sk = sock->sk; | |
edf02087 | 2424 | sk_change_net(sk, net); |
4fdb3bb7 | 2425 | |
a31f2d17 | 2426 | if (!cfg || cfg->groups < 32) |
4277a083 | 2427 | groups = 32; |
a31f2d17 PNA |
2428 | else |
2429 | groups = cfg->groups; | |
4277a083 | 2430 | |
5c398dc8 | 2431 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
4277a083 PM |
2432 | if (!listeners) |
2433 | goto out_sock_release; | |
2434 | ||
1da177e4 | 2435 | sk->sk_data_ready = netlink_data_ready; |
a31f2d17 PNA |
2436 | if (cfg && cfg->input) |
2437 | nlk_sk(sk)->netlink_rcv = cfg->input; | |
1da177e4 | 2438 | |
b4b51029 | 2439 | if (netlink_insert(sk, net, 0)) |
77247bbb | 2440 | goto out_sock_release; |
4fdb3bb7 | 2441 | |
77247bbb PM |
2442 | nlk = nlk_sk(sk); |
2443 | nlk->flags |= NETLINK_KERNEL_SOCKET; | |
4fdb3bb7 | 2444 | |
4fdb3bb7 | 2445 | netlink_table_grab(); |
b4b51029 EB |
2446 | if (!nl_table[unit].registered) { |
2447 | nl_table[unit].groups = groups; | |
5c398dc8 | 2448 | rcu_assign_pointer(nl_table[unit].listeners, listeners); |
b4b51029 EB |
2449 | nl_table[unit].cb_mutex = cb_mutex; |
2450 | nl_table[unit].module = module; | |
9785e10a PNA |
2451 | if (cfg) { |
2452 | nl_table[unit].bind = cfg->bind; | |
2453 | nl_table[unit].flags = cfg->flags; | |
da12c90e G |
2454 | if (cfg->compare) |
2455 | nl_table[unit].compare = cfg->compare; | |
9785e10a | 2456 | } |
b4b51029 | 2457 | nl_table[unit].registered = 1; |
f937f1f4 JJ |
2458 | } else { |
2459 | kfree(listeners); | |
869e58f8 | 2460 | nl_table[unit].registered++; |
b4b51029 | 2461 | } |
4fdb3bb7 | 2462 | netlink_table_ungrab(); |
77247bbb PM |
2463 | return sk; |
2464 | ||
4fdb3bb7 | 2465 | out_sock_release: |
4277a083 | 2466 | kfree(listeners); |
9dfbec1f | 2467 | netlink_kernel_release(sk); |
23fe1866 PE |
2468 | return NULL; |
2469 | ||
2470 | out_sock_release_nosk: | |
4fdb3bb7 | 2471 | sock_release(sock); |
77247bbb | 2472 | return NULL; |
1da177e4 | 2473 | } |
9f00d977 | 2474 | EXPORT_SYMBOL(__netlink_kernel_create); |
b7c6ba6e DL |
2475 | |
2476 | void | |
2477 | netlink_kernel_release(struct sock *sk) | |
2478 | { | |
edf02087 | 2479 | sk_release_kernel(sk); |
b7c6ba6e DL |
2480 | } |
2481 | EXPORT_SYMBOL(netlink_kernel_release); | |
2482 | ||
d136f1bd | 2483 | int __netlink_change_ngroups(struct sock *sk, unsigned int groups) |
b4ff4f04 | 2484 | { |
5c398dc8 | 2485 | struct listeners *new, *old; |
b4ff4f04 | 2486 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; |
b4ff4f04 JB |
2487 | |
2488 | if (groups < 32) | |
2489 | groups = 32; | |
2490 | ||
b4ff4f04 | 2491 | if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { |
5c398dc8 ED |
2492 | new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC); |
2493 | if (!new) | |
d136f1bd | 2494 | return -ENOMEM; |
6d772ac5 | 2495 | old = nl_deref_protected(tbl->listeners); |
5c398dc8 ED |
2496 | memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups)); |
2497 | rcu_assign_pointer(tbl->listeners, new); | |
2498 | ||
37b6b935 | 2499 | kfree_rcu(old, rcu); |
b4ff4f04 JB |
2500 | } |
2501 | tbl->groups = groups; | |
2502 | ||
d136f1bd JB |
2503 | return 0; |
2504 | } | |
2505 | ||
2506 | /** | |
2507 | * netlink_change_ngroups - change number of multicast groups | |
2508 | * | |
2509 | * This changes the number of multicast groups that are available | |
2510 | * on a certain netlink family. Note that it is not possible to | |
2511 | * change the number of groups to below 32. Also note that it does | |
2512 | * not implicitly call netlink_clear_multicast_users() when the | |
2513 | * number of groups is reduced. | |
2514 | * | |
2515 | * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). | |
2516 | * @groups: The new number of groups. | |
2517 | */ | |
2518 | int netlink_change_ngroups(struct sock *sk, unsigned int groups) | |
2519 | { | |
2520 | int err; | |
2521 | ||
2522 | netlink_table_grab(); | |
2523 | err = __netlink_change_ngroups(sk, groups); | |
b4ff4f04 | 2524 | netlink_table_ungrab(); |
d136f1bd | 2525 | |
b4ff4f04 JB |
2526 | return err; |
2527 | } | |
b4ff4f04 | 2528 | |
b8273570 JB |
2529 | void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group) |
2530 | { | |
2531 | struct sock *sk; | |
b8273570 JB |
2532 | struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; |
2533 | ||
b67bfe0d | 2534 | sk_for_each_bound(sk, &tbl->mc_list) |
b8273570 JB |
2535 | netlink_update_socket_mc(nlk_sk(sk), group, 0); |
2536 | } | |
2537 | ||
84659eb5 JB |
2538 | /** |
2539 | * netlink_clear_multicast_users - kick off multicast listeners | |
2540 | * | |
2541 | * This function removes all listeners from the given group. | |
2542 | * @ksk: The kernel netlink socket, as returned by | |
2543 | * netlink_kernel_create(). | |
2544 | * @group: The multicast group to clear. | |
2545 | */ | |
2546 | void netlink_clear_multicast_users(struct sock *ksk, unsigned int group) | |
2547 | { | |
84659eb5 | 2548 | netlink_table_grab(); |
b8273570 | 2549 | __netlink_clear_multicast_users(ksk, group); |
84659eb5 JB |
2550 | netlink_table_ungrab(); |
2551 | } | |
84659eb5 | 2552 | |
a46621a3 | 2553 | struct nlmsghdr * |
15e47304 | 2554 | __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags) |
a46621a3 DV |
2555 | { |
2556 | struct nlmsghdr *nlh; | |
573ce260 | 2557 | int size = nlmsg_msg_size(len); |
a46621a3 DV |
2558 | |
2559 | nlh = (struct nlmsghdr*)skb_put(skb, NLMSG_ALIGN(size)); | |
2560 | nlh->nlmsg_type = type; | |
2561 | nlh->nlmsg_len = size; | |
2562 | nlh->nlmsg_flags = flags; | |
15e47304 | 2563 | nlh->nlmsg_pid = portid; |
a46621a3 DV |
2564 | nlh->nlmsg_seq = seq; |
2565 | if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0) | |
573ce260 | 2566 | memset(nlmsg_data(nlh) + len, 0, NLMSG_ALIGN(size) - size); |
a46621a3 DV |
2567 | return nlh; |
2568 | } | |
2569 | EXPORT_SYMBOL(__nlmsg_put); | |
2570 | ||
1da177e4 LT |
2571 | /* |
2572 | * It looks a bit ugly. | |
2573 | * It would be better to create kernel thread. | |
2574 | */ | |
2575 | ||
2576 | static int netlink_dump(struct sock *sk) | |
2577 | { | |
2578 | struct netlink_sock *nlk = nlk_sk(sk); | |
2579 | struct netlink_callback *cb; | |
c7ac8679 | 2580 | struct sk_buff *skb = NULL; |
1da177e4 | 2581 | struct nlmsghdr *nlh; |
bf8b79e4 | 2582 | int len, err = -ENOBUFS; |
c7ac8679 | 2583 | int alloc_size; |
1da177e4 | 2584 | |
af65bdfc | 2585 | mutex_lock(nlk->cb_mutex); |
16b304f3 | 2586 | if (!nlk->cb_running) { |
bf8b79e4 TG |
2587 | err = -EINVAL; |
2588 | goto errout_skb; | |
1da177e4 LT |
2589 | } |
2590 | ||
16b304f3 | 2591 | cb = &nlk->cb; |
c7ac8679 GR |
2592 | alloc_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE); |
2593 | ||
f9c22888 PM |
2594 | if (!netlink_rx_is_mmaped(sk) && |
2595 | atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) | |
2596 | goto errout_skb; | |
2597 | skb = netlink_alloc_skb(sk, alloc_size, nlk->portid, GFP_KERNEL); | |
c7ac8679 | 2598 | if (!skb) |
c63d6ea3 | 2599 | goto errout_skb; |
f9c22888 | 2600 | netlink_skb_set_owner_r(skb, sk); |
c7ac8679 | 2601 | |
1da177e4 LT |
2602 | len = cb->dump(skb, cb); |
2603 | ||
2604 | if (len > 0) { | |
af65bdfc | 2605 | mutex_unlock(nlk->cb_mutex); |
b1153f29 SH |
2606 | |
2607 | if (sk_filter(sk, skb)) | |
2608 | kfree_skb(skb); | |
4a7e7c2a ED |
2609 | else |
2610 | __netlink_sendskb(sk, skb); | |
1da177e4 LT |
2611 | return 0; |
2612 | } | |
2613 | ||
bf8b79e4 TG |
2614 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); |
2615 | if (!nlh) | |
2616 | goto errout_skb; | |
2617 | ||
670dc283 JB |
2618 | nl_dump_check_consistent(cb, nlh); |
2619 | ||
bf8b79e4 TG |
2620 | memcpy(nlmsg_data(nlh), &len, sizeof(len)); |
2621 | ||
b1153f29 SH |
2622 | if (sk_filter(sk, skb)) |
2623 | kfree_skb(skb); | |
4a7e7c2a ED |
2624 | else |
2625 | __netlink_sendskb(sk, skb); | |
1da177e4 | 2626 | |
a8f74b22 TG |
2627 | if (cb->done) |
2628 | cb->done(cb); | |
1da177e4 | 2629 | |
16b304f3 PS |
2630 | nlk->cb_running = false; |
2631 | mutex_unlock(nlk->cb_mutex); | |
6dc878a8 | 2632 | module_put(cb->module); |
16b304f3 | 2633 | consume_skb(cb->skb); |
1da177e4 | 2634 | return 0; |
1797754e | 2635 | |
bf8b79e4 | 2636 | errout_skb: |
af65bdfc | 2637 | mutex_unlock(nlk->cb_mutex); |
bf8b79e4 | 2638 | kfree_skb(skb); |
bf8b79e4 | 2639 | return err; |
1da177e4 LT |
2640 | } |
2641 | ||
6dc878a8 G |
2642 | int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, |
2643 | const struct nlmsghdr *nlh, | |
2644 | struct netlink_dump_control *control) | |
1da177e4 LT |
2645 | { |
2646 | struct netlink_callback *cb; | |
2647 | struct sock *sk; | |
2648 | struct netlink_sock *nlk; | |
b44d211e | 2649 | int ret; |
1da177e4 | 2650 | |
f9c22888 PM |
2651 | /* Memory mapped dump requests need to be copied to avoid looping |
2652 | * on the pending state in netlink_mmap_sendmsg() while the CB hold | |
2653 | * a reference to the skb. | |
2654 | */ | |
2655 | if (netlink_skb_is_mmaped(skb)) { | |
2656 | skb = skb_copy(skb, GFP_KERNEL); | |
16b304f3 | 2657 | if (skb == NULL) |
f9c22888 | 2658 | return -ENOBUFS; |
f9c22888 PM |
2659 | } else |
2660 | atomic_inc(&skb->users); | |
2661 | ||
15e47304 | 2662 | sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).portid); |
1da177e4 | 2663 | if (sk == NULL) { |
16b304f3 PS |
2664 | ret = -ECONNREFUSED; |
2665 | goto error_free; | |
1da177e4 | 2666 | } |
6dc878a8 | 2667 | |
16b304f3 | 2668 | nlk = nlk_sk(sk); |
af65bdfc | 2669 | mutex_lock(nlk->cb_mutex); |
6dc878a8 | 2670 | /* A dump is in progress... */ |
16b304f3 | 2671 | if (nlk->cb_running) { |
6dc878a8 | 2672 | ret = -EBUSY; |
16b304f3 | 2673 | goto error_unlock; |
1da177e4 | 2674 | } |
6dc878a8 | 2675 | /* add reference of module which cb->dump belongs to */ |
16b304f3 | 2676 | if (!try_module_get(control->module)) { |
6dc878a8 | 2677 | ret = -EPROTONOSUPPORT; |
16b304f3 | 2678 | goto error_unlock; |
6dc878a8 G |
2679 | } |
2680 | ||
16b304f3 PS |
2681 | cb = &nlk->cb; |
2682 | memset(cb, 0, sizeof(*cb)); | |
2683 | cb->dump = control->dump; | |
2684 | cb->done = control->done; | |
2685 | cb->nlh = nlh; | |
2686 | cb->data = control->data; | |
2687 | cb->module = control->module; | |
2688 | cb->min_dump_alloc = control->min_dump_alloc; | |
2689 | cb->skb = skb; | |
2690 | ||
2691 | nlk->cb_running = true; | |
2692 | ||
af65bdfc | 2693 | mutex_unlock(nlk->cb_mutex); |
1da177e4 | 2694 | |
b44d211e | 2695 | ret = netlink_dump(sk); |
1da177e4 | 2696 | sock_put(sk); |
5c58298c | 2697 | |
b44d211e AV |
2698 | if (ret) |
2699 | return ret; | |
2700 | ||
5c58298c DL |
2701 | /* We successfully started a dump, by returning -EINTR we |
2702 | * signal not to send ACK even if it was requested. | |
2703 | */ | |
2704 | return -EINTR; | |
16b304f3 PS |
2705 | |
2706 | error_unlock: | |
2707 | sock_put(sk); | |
2708 | mutex_unlock(nlk->cb_mutex); | |
2709 | error_free: | |
2710 | kfree_skb(skb); | |
2711 | return ret; | |
1da177e4 | 2712 | } |
6dc878a8 | 2713 | EXPORT_SYMBOL(__netlink_dump_start); |
1da177e4 LT |
2714 | |
2715 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) | |
2716 | { | |
2717 | struct sk_buff *skb; | |
2718 | struct nlmsghdr *rep; | |
2719 | struct nlmsgerr *errmsg; | |
339bf98f | 2720 | size_t payload = sizeof(*errmsg); |
1da177e4 | 2721 | |
339bf98f TG |
2722 | /* error messages get the original request appened */ |
2723 | if (err) | |
2724 | payload += nlmsg_len(nlh); | |
1da177e4 | 2725 | |
f9c22888 PM |
2726 | skb = netlink_alloc_skb(in_skb->sk, nlmsg_total_size(payload), |
2727 | NETLINK_CB(in_skb).portid, GFP_KERNEL); | |
1da177e4 LT |
2728 | if (!skb) { |
2729 | struct sock *sk; | |
2730 | ||
3b1e0a65 | 2731 | sk = netlink_lookup(sock_net(in_skb->sk), |
b4b51029 | 2732 | in_skb->sk->sk_protocol, |
15e47304 | 2733 | NETLINK_CB(in_skb).portid); |
1da177e4 LT |
2734 | if (sk) { |
2735 | sk->sk_err = ENOBUFS; | |
2736 | sk->sk_error_report(sk); | |
2737 | sock_put(sk); | |
2738 | } | |
2739 | return; | |
2740 | } | |
2741 | ||
15e47304 | 2742 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, |
5dba93ae | 2743 | NLMSG_ERROR, payload, 0); |
bf8b79e4 | 2744 | errmsg = nlmsg_data(rep); |
1da177e4 | 2745 | errmsg->error = err; |
bf8b79e4 | 2746 | memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh)); |
15e47304 | 2747 | netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT); |
1da177e4 | 2748 | } |
6ac552fd | 2749 | EXPORT_SYMBOL(netlink_ack); |
1da177e4 | 2750 | |
cd40b7d3 | 2751 | int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
1d00a4eb | 2752 | struct nlmsghdr *)) |
82ace47a | 2753 | { |
82ace47a TG |
2754 | struct nlmsghdr *nlh; |
2755 | int err; | |
2756 | ||
2757 | while (skb->len >= nlmsg_total_size(0)) { | |
cd40b7d3 DL |
2758 | int msglen; |
2759 | ||
b529ccf2 | 2760 | nlh = nlmsg_hdr(skb); |
d35b6856 | 2761 | err = 0; |
82ace47a | 2762 | |
ad8e4b75 | 2763 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
2764 | return 0; |
2765 | ||
d35b6856 TG |
2766 | /* Only requests are handled by the kernel */ |
2767 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | |
5c58298c | 2768 | goto ack; |
45e7ae7f TG |
2769 | |
2770 | /* Skip control messages */ | |
2771 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | |
5c58298c | 2772 | goto ack; |
d35b6856 | 2773 | |
1d00a4eb | 2774 | err = cb(skb, nlh); |
5c58298c DL |
2775 | if (err == -EINTR) |
2776 | goto skip; | |
2777 | ||
2778 | ack: | |
d35b6856 | 2779 | if (nlh->nlmsg_flags & NLM_F_ACK || err) |
82ace47a | 2780 | netlink_ack(skb, nlh, err); |
82ace47a | 2781 | |
5c58298c | 2782 | skip: |
6ac552fd | 2783 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
cd40b7d3 DL |
2784 | if (msglen > skb->len) |
2785 | msglen = skb->len; | |
2786 | skb_pull(skb, msglen); | |
82ace47a TG |
2787 | } |
2788 | ||
2789 | return 0; | |
2790 | } | |
6ac552fd | 2791 | EXPORT_SYMBOL(netlink_rcv_skb); |
82ace47a | 2792 | |
d387f6ad TG |
2793 | /** |
2794 | * nlmsg_notify - send a notification netlink message | |
2795 | * @sk: netlink socket to use | |
2796 | * @skb: notification message | |
15e47304 | 2797 | * @portid: destination netlink portid for reports or 0 |
d387f6ad TG |
2798 | * @group: destination multicast group or 0 |
2799 | * @report: 1 to report back, 0 to disable | |
2800 | * @flags: allocation flags | |
2801 | */ | |
15e47304 | 2802 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, |
d387f6ad TG |
2803 | unsigned int group, int report, gfp_t flags) |
2804 | { | |
2805 | int err = 0; | |
2806 | ||
2807 | if (group) { | |
15e47304 | 2808 | int exclude_portid = 0; |
d387f6ad TG |
2809 | |
2810 | if (report) { | |
2811 | atomic_inc(&skb->users); | |
15e47304 | 2812 | exclude_portid = portid; |
d387f6ad TG |
2813 | } |
2814 | ||
1ce85fe4 PNA |
2815 | /* errors reported via destination sk->sk_err, but propagate |
2816 | * delivery errors if NETLINK_BROADCAST_ERROR flag is set */ | |
15e47304 | 2817 | err = nlmsg_multicast(sk, skb, exclude_portid, group, flags); |
d387f6ad TG |
2818 | } |
2819 | ||
1ce85fe4 PNA |
2820 | if (report) { |
2821 | int err2; | |
2822 | ||
15e47304 | 2823 | err2 = nlmsg_unicast(sk, skb, portid); |
1ce85fe4 PNA |
2824 | if (!err || err == -ESRCH) |
2825 | err = err2; | |
2826 | } | |
d387f6ad TG |
2827 | |
2828 | return err; | |
2829 | } | |
6ac552fd | 2830 | EXPORT_SYMBOL(nlmsg_notify); |
d387f6ad | 2831 | |
1da177e4 LT |
2832 | #ifdef CONFIG_PROC_FS |
2833 | struct nl_seq_iter { | |
e372c414 | 2834 | struct seq_net_private p; |
1da177e4 LT |
2835 | int link; |
2836 | int hash_idx; | |
2837 | }; | |
2838 | ||
2839 | static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) | |
2840 | { | |
2841 | struct nl_seq_iter *iter = seq->private; | |
2842 | int i, j; | |
2843 | struct sock *s; | |
1da177e4 LT |
2844 | loff_t off = 0; |
2845 | ||
6ac552fd | 2846 | for (i = 0; i < MAX_LINKS; i++) { |
15e47304 | 2847 | struct nl_portid_hash *hash = &nl_table[i].hash; |
1da177e4 LT |
2848 | |
2849 | for (j = 0; j <= hash->mask; j++) { | |
b67bfe0d | 2850 | sk_for_each(s, &hash->table[j]) { |
1218854a | 2851 | if (sock_net(s) != seq_file_net(seq)) |
b4b51029 | 2852 | continue; |
1da177e4 LT |
2853 | if (off == pos) { |
2854 | iter->link = i; | |
2855 | iter->hash_idx = j; | |
2856 | return s; | |
2857 | } | |
2858 | ++off; | |
2859 | } | |
2860 | } | |
2861 | } | |
2862 | return NULL; | |
2863 | } | |
2864 | ||
2865 | static void *netlink_seq_start(struct seq_file *seq, loff_t *pos) | |
9a429c49 | 2866 | __acquires(nl_table_lock) |
1da177e4 LT |
2867 | { |
2868 | read_lock(&nl_table_lock); | |
2869 | return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
2870 | } | |
2871 | ||
2872 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2873 | { | |
2874 | struct sock *s; | |
2875 | struct nl_seq_iter *iter; | |
da12c90e | 2876 | struct net *net; |
1da177e4 LT |
2877 | int i, j; |
2878 | ||
2879 | ++*pos; | |
2880 | ||
2881 | if (v == SEQ_START_TOKEN) | |
2882 | return netlink_seq_socket_idx(seq, 0); | |
746fac4d | 2883 | |
da12c90e | 2884 | net = seq_file_net(seq); |
b4b51029 EB |
2885 | iter = seq->private; |
2886 | s = v; | |
2887 | do { | |
2888 | s = sk_next(s); | |
da12c90e | 2889 | } while (s && !nl_table[s->sk_protocol].compare(net, s)); |
1da177e4 LT |
2890 | if (s) |
2891 | return s; | |
2892 | ||
1da177e4 LT |
2893 | i = iter->link; |
2894 | j = iter->hash_idx + 1; | |
2895 | ||
2896 | do { | |
15e47304 | 2897 | struct nl_portid_hash *hash = &nl_table[i].hash; |
1da177e4 LT |
2898 | |
2899 | for (; j <= hash->mask; j++) { | |
2900 | s = sk_head(&hash->table[j]); | |
da12c90e G |
2901 | |
2902 | while (s && !nl_table[s->sk_protocol].compare(net, s)) | |
b4b51029 | 2903 | s = sk_next(s); |
1da177e4 LT |
2904 | if (s) { |
2905 | iter->link = i; | |
2906 | iter->hash_idx = j; | |
2907 | return s; | |
2908 | } | |
2909 | } | |
2910 | ||
2911 | j = 0; | |
2912 | } while (++i < MAX_LINKS); | |
2913 | ||
2914 | return NULL; | |
2915 | } | |
2916 | ||
2917 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
9a429c49 | 2918 | __releases(nl_table_lock) |
1da177e4 LT |
2919 | { |
2920 | read_unlock(&nl_table_lock); | |
2921 | } | |
2922 | ||
2923 | ||
2924 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
2925 | { | |
658cb354 | 2926 | if (v == SEQ_START_TOKEN) { |
1da177e4 LT |
2927 | seq_puts(seq, |
2928 | "sk Eth Pid Groups " | |
cf0aa4e0 | 2929 | "Rmem Wmem Dump Locks Drops Inode\n"); |
658cb354 | 2930 | } else { |
1da177e4 LT |
2931 | struct sock *s = v; |
2932 | struct netlink_sock *nlk = nlk_sk(s); | |
2933 | ||
16b304f3 | 2934 | seq_printf(seq, "%pK %-3d %-6u %08x %-8d %-8d %d %-8d %-8d %-8lu\n", |
1da177e4 LT |
2935 | s, |
2936 | s->sk_protocol, | |
15e47304 | 2937 | nlk->portid, |
513c2500 | 2938 | nlk->groups ? (u32)nlk->groups[0] : 0, |
31e6d363 ED |
2939 | sk_rmem_alloc_get(s), |
2940 | sk_wmem_alloc_get(s), | |
16b304f3 | 2941 | nlk->cb_running, |
38938bfe | 2942 | atomic_read(&s->sk_refcnt), |
cf0aa4e0 MY |
2943 | atomic_read(&s->sk_drops), |
2944 | sock_i_ino(s) | |
1da177e4 LT |
2945 | ); |
2946 | ||
2947 | } | |
2948 | return 0; | |
2949 | } | |
2950 | ||
56b3d975 | 2951 | static const struct seq_operations netlink_seq_ops = { |
1da177e4 LT |
2952 | .start = netlink_seq_start, |
2953 | .next = netlink_seq_next, | |
2954 | .stop = netlink_seq_stop, | |
2955 | .show = netlink_seq_show, | |
2956 | }; | |
2957 | ||
2958 | ||
2959 | static int netlink_seq_open(struct inode *inode, struct file *file) | |
2960 | { | |
e372c414 DL |
2961 | return seq_open_net(inode, file, &netlink_seq_ops, |
2962 | sizeof(struct nl_seq_iter)); | |
b4b51029 EB |
2963 | } |
2964 | ||
da7071d7 | 2965 | static const struct file_operations netlink_seq_fops = { |
1da177e4 LT |
2966 | .owner = THIS_MODULE, |
2967 | .open = netlink_seq_open, | |
2968 | .read = seq_read, | |
2969 | .llseek = seq_lseek, | |
e372c414 | 2970 | .release = seq_release_net, |
1da177e4 LT |
2971 | }; |
2972 | ||
2973 | #endif | |
2974 | ||
2975 | int netlink_register_notifier(struct notifier_block *nb) | |
2976 | { | |
e041c683 | 2977 | return atomic_notifier_chain_register(&netlink_chain, nb); |
1da177e4 | 2978 | } |
6ac552fd | 2979 | EXPORT_SYMBOL(netlink_register_notifier); |
1da177e4 LT |
2980 | |
2981 | int netlink_unregister_notifier(struct notifier_block *nb) | |
2982 | { | |
e041c683 | 2983 | return atomic_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 | 2984 | } |
6ac552fd | 2985 | EXPORT_SYMBOL(netlink_unregister_notifier); |
746fac4d | 2986 | |
90ddc4f0 | 2987 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
2988 | .family = PF_NETLINK, |
2989 | .owner = THIS_MODULE, | |
2990 | .release = netlink_release, | |
2991 | .bind = netlink_bind, | |
2992 | .connect = netlink_connect, | |
2993 | .socketpair = sock_no_socketpair, | |
2994 | .accept = sock_no_accept, | |
2995 | .getname = netlink_getname, | |
9652e931 | 2996 | .poll = netlink_poll, |
1da177e4 LT |
2997 | .ioctl = sock_no_ioctl, |
2998 | .listen = sock_no_listen, | |
2999 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
3000 | .setsockopt = netlink_setsockopt, |
3001 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
3002 | .sendmsg = netlink_sendmsg, |
3003 | .recvmsg = netlink_recvmsg, | |
ccdfcc39 | 3004 | .mmap = netlink_mmap, |
1da177e4 LT |
3005 | .sendpage = sock_no_sendpage, |
3006 | }; | |
3007 | ||
ec1b4cf7 | 3008 | static const struct net_proto_family netlink_family_ops = { |
1da177e4 LT |
3009 | .family = PF_NETLINK, |
3010 | .create = netlink_create, | |
3011 | .owner = THIS_MODULE, /* for consistency 8) */ | |
3012 | }; | |
3013 | ||
4665079c | 3014 | static int __net_init netlink_net_init(struct net *net) |
b4b51029 EB |
3015 | { |
3016 | #ifdef CONFIG_PROC_FS | |
d4beaa66 | 3017 | if (!proc_create("netlink", 0, net->proc_net, &netlink_seq_fops)) |
b4b51029 EB |
3018 | return -ENOMEM; |
3019 | #endif | |
3020 | return 0; | |
3021 | } | |
3022 | ||
4665079c | 3023 | static void __net_exit netlink_net_exit(struct net *net) |
b4b51029 EB |
3024 | { |
3025 | #ifdef CONFIG_PROC_FS | |
ece31ffd | 3026 | remove_proc_entry("netlink", net->proc_net); |
b4b51029 EB |
3027 | #endif |
3028 | } | |
3029 | ||
b963ea89 DM |
3030 | static void __init netlink_add_usersock_entry(void) |
3031 | { | |
5c398dc8 | 3032 | struct listeners *listeners; |
b963ea89 DM |
3033 | int groups = 32; |
3034 | ||
5c398dc8 | 3035 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
b963ea89 | 3036 | if (!listeners) |
5c398dc8 | 3037 | panic("netlink_add_usersock_entry: Cannot allocate listeners\n"); |
b963ea89 DM |
3038 | |
3039 | netlink_table_grab(); | |
3040 | ||
3041 | nl_table[NETLINK_USERSOCK].groups = groups; | |
5c398dc8 | 3042 | rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners); |
b963ea89 DM |
3043 | nl_table[NETLINK_USERSOCK].module = THIS_MODULE; |
3044 | nl_table[NETLINK_USERSOCK].registered = 1; | |
9785e10a | 3045 | nl_table[NETLINK_USERSOCK].flags = NL_CFG_F_NONROOT_SEND; |
b963ea89 DM |
3046 | |
3047 | netlink_table_ungrab(); | |
3048 | } | |
3049 | ||
022cbae6 | 3050 | static struct pernet_operations __net_initdata netlink_net_ops = { |
b4b51029 EB |
3051 | .init = netlink_net_init, |
3052 | .exit = netlink_net_exit, | |
3053 | }; | |
3054 | ||
1da177e4 LT |
3055 | static int __init netlink_proto_init(void) |
3056 | { | |
1da177e4 | 3057 | int i; |
26ff5ddc | 3058 | unsigned long limit; |
1da177e4 LT |
3059 | unsigned int order; |
3060 | int err = proto_register(&netlink_proto, 0); | |
3061 | ||
3062 | if (err != 0) | |
3063 | goto out; | |
3064 | ||
fab25745 | 3065 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb)); |
1da177e4 | 3066 | |
0da974f4 | 3067 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
3068 | if (!nl_table) |
3069 | goto panic; | |
1da177e4 | 3070 | |
4481374c JB |
3071 | if (totalram_pages >= (128 * 1024)) |
3072 | limit = totalram_pages >> (21 - PAGE_SHIFT); | |
1da177e4 | 3073 | else |
4481374c | 3074 | limit = totalram_pages >> (23 - PAGE_SHIFT); |
1da177e4 | 3075 | |
26ff5ddc DC |
3076 | order = get_bitmask_order(limit) - 1 + PAGE_SHIFT; |
3077 | limit = (1UL << order) / sizeof(struct hlist_head); | |
3078 | order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1; | |
1da177e4 LT |
3079 | |
3080 | for (i = 0; i < MAX_LINKS; i++) { | |
15e47304 | 3081 | struct nl_portid_hash *hash = &nl_table[i].hash; |
1da177e4 | 3082 | |
15e47304 | 3083 | hash->table = nl_portid_hash_zalloc(1 * sizeof(*hash->table)); |
1da177e4 LT |
3084 | if (!hash->table) { |
3085 | while (i-- > 0) | |
15e47304 | 3086 | nl_portid_hash_free(nl_table[i].hash.table, |
1da177e4 LT |
3087 | 1 * sizeof(*hash->table)); |
3088 | kfree(nl_table); | |
fab2caf6 | 3089 | goto panic; |
1da177e4 | 3090 | } |
1da177e4 LT |
3091 | hash->max_shift = order; |
3092 | hash->shift = 0; | |
3093 | hash->mask = 0; | |
3094 | hash->rehash_time = jiffies; | |
ca15febf G |
3095 | |
3096 | nl_table[i].compare = netlink_compare; | |
1da177e4 LT |
3097 | } |
3098 | ||
bcbde0d4 DB |
3099 | INIT_LIST_HEAD(&netlink_tap_all); |
3100 | ||
b963ea89 DM |
3101 | netlink_add_usersock_entry(); |
3102 | ||
1da177e4 | 3103 | sock_register(&netlink_family_ops); |
b4b51029 | 3104 | register_pernet_subsys(&netlink_net_ops); |
746fac4d | 3105 | /* The netlink device handler may be needed early. */ |
1da177e4 LT |
3106 | rtnetlink_init(); |
3107 | out: | |
3108 | return err; | |
fab2caf6 AM |
3109 | panic: |
3110 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
3111 | } |
3112 | ||
1da177e4 | 3113 | core_initcall(netlink_proto_init); |