Commit | Line | Data |
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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> | |
7c0f6ba6 | 43 | #include <linux/uaccess.h> |
1da177e4 LT |
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> |
e341694e | 61 | #include <linux/rhashtable.h> |
9652e931 | 62 | #include <asm/cacheflush.h> |
e341694e | 63 | #include <linux/hash.h> |
ee1c2442 | 64 | #include <linux/genetlink.h> |
54e0f520 | 65 | |
457c4cbc | 66 | #include <net/net_namespace.h> |
1da177e4 LT |
67 | #include <net/sock.h> |
68 | #include <net/scm.h> | |
82ace47a | 69 | #include <net/netlink.h> |
1da177e4 | 70 | |
0f29c768 | 71 | #include "af_netlink.h" |
1da177e4 | 72 | |
5c398dc8 ED |
73 | struct listeners { |
74 | struct rcu_head rcu; | |
75 | unsigned long masks[0]; | |
6c04bb18 JB |
76 | }; |
77 | ||
cd967e05 | 78 | /* state bits */ |
cc3a572f | 79 | #define NETLINK_S_CONGESTED 0x0 |
cd967e05 PM |
80 | |
81 | /* flags */ | |
cc3a572f ND |
82 | #define NETLINK_F_KERNEL_SOCKET 0x1 |
83 | #define NETLINK_F_RECV_PKTINFO 0x2 | |
84 | #define NETLINK_F_BROADCAST_SEND_ERROR 0x4 | |
85 | #define NETLINK_F_RECV_NO_ENOBUFS 0x8 | |
59324cf3 | 86 | #define NETLINK_F_LISTEN_ALL_NSID 0x10 |
0a6a3a23 | 87 | #define NETLINK_F_CAP_ACK 0x20 |
77247bbb | 88 | |
035c4c16 | 89 | static inline int netlink_is_kernel(struct sock *sk) |
aed81560 | 90 | { |
cc3a572f | 91 | return nlk_sk(sk)->flags & NETLINK_F_KERNEL_SOCKET; |
aed81560 DL |
92 | } |
93 | ||
91dd93f9 | 94 | struct netlink_table *nl_table __read_mostly; |
0f29c768 | 95 | EXPORT_SYMBOL_GPL(nl_table); |
1da177e4 LT |
96 | |
97 | static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); | |
98 | ||
8a0f5ccf HX |
99 | static struct lock_class_key nlk_cb_mutex_keys[MAX_LINKS]; |
100 | ||
101 | static const char *const nlk_cb_mutex_key_strings[MAX_LINKS + 1] = { | |
102 | "nlk_cb_mutex-ROUTE", | |
103 | "nlk_cb_mutex-1", | |
104 | "nlk_cb_mutex-USERSOCK", | |
105 | "nlk_cb_mutex-FIREWALL", | |
106 | "nlk_cb_mutex-SOCK_DIAG", | |
107 | "nlk_cb_mutex-NFLOG", | |
108 | "nlk_cb_mutex-XFRM", | |
109 | "nlk_cb_mutex-SELINUX", | |
110 | "nlk_cb_mutex-ISCSI", | |
111 | "nlk_cb_mutex-AUDIT", | |
112 | "nlk_cb_mutex-FIB_LOOKUP", | |
113 | "nlk_cb_mutex-CONNECTOR", | |
114 | "nlk_cb_mutex-NETFILTER", | |
115 | "nlk_cb_mutex-IP6_FW", | |
116 | "nlk_cb_mutex-DNRTMSG", | |
117 | "nlk_cb_mutex-KOBJECT_UEVENT", | |
118 | "nlk_cb_mutex-GENERIC", | |
119 | "nlk_cb_mutex-17", | |
120 | "nlk_cb_mutex-SCSITRANSPORT", | |
121 | "nlk_cb_mutex-ECRYPTFS", | |
122 | "nlk_cb_mutex-RDMA", | |
123 | "nlk_cb_mutex-CRYPTO", | |
124 | "nlk_cb_mutex-SMC", | |
125 | "nlk_cb_mutex-23", | |
126 | "nlk_cb_mutex-24", | |
127 | "nlk_cb_mutex-25", | |
128 | "nlk_cb_mutex-26", | |
129 | "nlk_cb_mutex-27", | |
130 | "nlk_cb_mutex-28", | |
131 | "nlk_cb_mutex-29", | |
132 | "nlk_cb_mutex-30", | |
133 | "nlk_cb_mutex-31", | |
134 | "nlk_cb_mutex-MAX_LINKS" | |
135 | }; | |
136 | ||
1da177e4 | 137 | static int netlink_dump(struct sock *sk); |
9652e931 | 138 | static void netlink_skb_destructor(struct sk_buff *skb); |
1da177e4 | 139 | |
78fd1d0a | 140 | /* nl_table locking explained: |
21e4902a | 141 | * Lookup and traversal are protected with an RCU read-side lock. Insertion |
c5adde94 | 142 | * and removal are protected with per bucket lock while using RCU list |
21e4902a TG |
143 | * modification primitives and may run in parallel to RCU protected lookups. |
144 | * Destruction of the Netlink socket may only occur *after* nl_table_lock has | |
145 | * been acquired * either during or after the socket has been removed from | |
146 | * the list and after an RCU grace period. | |
78fd1d0a | 147 | */ |
0f29c768 AV |
148 | DEFINE_RWLOCK(nl_table_lock); |
149 | EXPORT_SYMBOL_GPL(nl_table_lock); | |
1da177e4 LT |
150 | static atomic_t nl_table_users = ATOMIC_INIT(0); |
151 | ||
6d772ac5 ED |
152 | #define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock)); |
153 | ||
efa172f4 | 154 | static BLOCKING_NOTIFIER_HEAD(netlink_chain); |
1da177e4 | 155 | |
bcbde0d4 DB |
156 | static DEFINE_SPINLOCK(netlink_tap_lock); |
157 | static struct list_head netlink_tap_all __read_mostly; | |
158 | ||
c428ecd1 HX |
159 | static const struct rhashtable_params netlink_rhashtable_params; |
160 | ||
b57ef81f | 161 | static inline u32 netlink_group_mask(u32 group) |
d629b836 PM |
162 | { |
163 | return group ? 1 << (group - 1) : 0; | |
164 | } | |
165 | ||
1853c949 DB |
166 | static struct sk_buff *netlink_to_full_skb(const struct sk_buff *skb, |
167 | gfp_t gfp_mask) | |
168 | { | |
169 | unsigned int len = skb_end_offset(skb); | |
170 | struct sk_buff *new; | |
171 | ||
172 | new = alloc_skb(len, gfp_mask); | |
173 | if (new == NULL) | |
174 | return NULL; | |
175 | ||
176 | NETLINK_CB(new).portid = NETLINK_CB(skb).portid; | |
177 | NETLINK_CB(new).dst_group = NETLINK_CB(skb).dst_group; | |
178 | NETLINK_CB(new).creds = NETLINK_CB(skb).creds; | |
179 | ||
180 | memcpy(skb_put(new, len), skb->data, len); | |
181 | return new; | |
182 | } | |
183 | ||
bcbde0d4 DB |
184 | int netlink_add_tap(struct netlink_tap *nt) |
185 | { | |
186 | if (unlikely(nt->dev->type != ARPHRD_NETLINK)) | |
187 | return -EINVAL; | |
188 | ||
189 | spin_lock(&netlink_tap_lock); | |
190 | list_add_rcu(&nt->list, &netlink_tap_all); | |
191 | spin_unlock(&netlink_tap_lock); | |
192 | ||
fcd4d35e | 193 | __module_get(nt->module); |
bcbde0d4 DB |
194 | |
195 | return 0; | |
196 | } | |
197 | EXPORT_SYMBOL_GPL(netlink_add_tap); | |
198 | ||
2173f8d9 | 199 | static int __netlink_remove_tap(struct netlink_tap *nt) |
bcbde0d4 DB |
200 | { |
201 | bool found = false; | |
202 | struct netlink_tap *tmp; | |
203 | ||
204 | spin_lock(&netlink_tap_lock); | |
205 | ||
206 | list_for_each_entry(tmp, &netlink_tap_all, list) { | |
207 | if (nt == tmp) { | |
208 | list_del_rcu(&nt->list); | |
209 | found = true; | |
210 | goto out; | |
211 | } | |
212 | } | |
213 | ||
214 | pr_warn("__netlink_remove_tap: %p not found\n", nt); | |
215 | out: | |
216 | spin_unlock(&netlink_tap_lock); | |
217 | ||
92b80eb3 | 218 | if (found) |
bcbde0d4 DB |
219 | module_put(nt->module); |
220 | ||
221 | return found ? 0 : -ENODEV; | |
222 | } | |
bcbde0d4 DB |
223 | |
224 | int netlink_remove_tap(struct netlink_tap *nt) | |
225 | { | |
226 | int ret; | |
227 | ||
228 | ret = __netlink_remove_tap(nt); | |
229 | synchronize_net(); | |
230 | ||
231 | return ret; | |
232 | } | |
233 | EXPORT_SYMBOL_GPL(netlink_remove_tap); | |
234 | ||
5ffd5cdd DB |
235 | static bool netlink_filter_tap(const struct sk_buff *skb) |
236 | { | |
237 | struct sock *sk = skb->sk; | |
5ffd5cdd DB |
238 | |
239 | /* We take the more conservative approach and | |
240 | * whitelist socket protocols that may pass. | |
241 | */ | |
242 | switch (sk->sk_protocol) { | |
243 | case NETLINK_ROUTE: | |
244 | case NETLINK_USERSOCK: | |
245 | case NETLINK_SOCK_DIAG: | |
246 | case NETLINK_NFLOG: | |
247 | case NETLINK_XFRM: | |
248 | case NETLINK_FIB_LOOKUP: | |
249 | case NETLINK_NETFILTER: | |
250 | case NETLINK_GENERIC: | |
498044bb | 251 | return true; |
5ffd5cdd DB |
252 | } |
253 | ||
498044bb | 254 | return false; |
5ffd5cdd DB |
255 | } |
256 | ||
bcbde0d4 DB |
257 | static int __netlink_deliver_tap_skb(struct sk_buff *skb, |
258 | struct net_device *dev) | |
259 | { | |
260 | struct sk_buff *nskb; | |
5ffd5cdd | 261 | struct sock *sk = skb->sk; |
bcbde0d4 DB |
262 | int ret = -ENOMEM; |
263 | ||
264 | dev_hold(dev); | |
1853c949 | 265 | |
d1b4c689 | 266 | if (is_vmalloc_addr(skb->head)) |
1853c949 DB |
267 | nskb = netlink_to_full_skb(skb, GFP_ATOMIC); |
268 | else | |
269 | nskb = skb_clone(skb, GFP_ATOMIC); | |
bcbde0d4 DB |
270 | if (nskb) { |
271 | nskb->dev = dev; | |
5ffd5cdd | 272 | nskb->protocol = htons((u16) sk->sk_protocol); |
604d13c9 DB |
273 | nskb->pkt_type = netlink_is_kernel(sk) ? |
274 | PACKET_KERNEL : PACKET_USER; | |
4e48ed88 | 275 | skb_reset_network_header(nskb); |
bcbde0d4 DB |
276 | ret = dev_queue_xmit(nskb); |
277 | if (unlikely(ret > 0)) | |
278 | ret = net_xmit_errno(ret); | |
279 | } | |
280 | ||
281 | dev_put(dev); | |
282 | return ret; | |
283 | } | |
284 | ||
285 | static void __netlink_deliver_tap(struct sk_buff *skb) | |
286 | { | |
287 | int ret; | |
288 | struct netlink_tap *tmp; | |
289 | ||
5ffd5cdd DB |
290 | if (!netlink_filter_tap(skb)) |
291 | return; | |
292 | ||
bcbde0d4 DB |
293 | list_for_each_entry_rcu(tmp, &netlink_tap_all, list) { |
294 | ret = __netlink_deliver_tap_skb(skb, tmp->dev); | |
295 | if (unlikely(ret)) | |
296 | break; | |
297 | } | |
298 | } | |
299 | ||
300 | static void netlink_deliver_tap(struct sk_buff *skb) | |
301 | { | |
302 | rcu_read_lock(); | |
303 | ||
304 | if (unlikely(!list_empty(&netlink_tap_all))) | |
305 | __netlink_deliver_tap(skb); | |
306 | ||
307 | rcu_read_unlock(); | |
308 | } | |
309 | ||
73bfd370 DB |
310 | static void netlink_deliver_tap_kernel(struct sock *dst, struct sock *src, |
311 | struct sk_buff *skb) | |
312 | { | |
313 | if (!(netlink_is_kernel(dst) && netlink_is_kernel(src))) | |
314 | netlink_deliver_tap(skb); | |
315 | } | |
316 | ||
cd1df525 PM |
317 | static void netlink_overrun(struct sock *sk) |
318 | { | |
319 | struct netlink_sock *nlk = nlk_sk(sk); | |
320 | ||
cc3a572f ND |
321 | if (!(nlk->flags & NETLINK_F_RECV_NO_ENOBUFS)) { |
322 | if (!test_and_set_bit(NETLINK_S_CONGESTED, | |
323 | &nlk_sk(sk)->state)) { | |
cd1df525 PM |
324 | sk->sk_err = ENOBUFS; |
325 | sk->sk_error_report(sk); | |
326 | } | |
327 | } | |
328 | atomic_inc(&sk->sk_drops); | |
329 | } | |
330 | ||
331 | static void netlink_rcv_wake(struct sock *sk) | |
332 | { | |
333 | struct netlink_sock *nlk = nlk_sk(sk); | |
334 | ||
335 | if (skb_queue_empty(&sk->sk_receive_queue)) | |
cc3a572f ND |
336 | clear_bit(NETLINK_S_CONGESTED, &nlk->state); |
337 | if (!test_bit(NETLINK_S_CONGESTED, &nlk->state)) | |
cd1df525 PM |
338 | wake_up_interruptible(&nlk->wait); |
339 | } | |
340 | ||
cf0a018a PM |
341 | static void netlink_skb_destructor(struct sk_buff *skb) |
342 | { | |
c05cdb1b | 343 | if (is_vmalloc_addr(skb->head)) { |
3a36515f PN |
344 | if (!skb->cloned || |
345 | !atomic_dec_return(&(skb_shinfo(skb)->dataref))) | |
346 | vfree(skb->head); | |
347 | ||
c05cdb1b PNA |
348 | skb->head = NULL; |
349 | } | |
9652e931 PM |
350 | if (skb->sk != NULL) |
351 | sock_rfree(skb); | |
cf0a018a PM |
352 | } |
353 | ||
354 | static void netlink_skb_set_owner_r(struct sk_buff *skb, struct sock *sk) | |
355 | { | |
356 | WARN_ON(skb->sk != NULL); | |
357 | skb->sk = sk; | |
358 | skb->destructor = netlink_skb_destructor; | |
359 | atomic_add(skb->truesize, &sk->sk_rmem_alloc); | |
360 | sk_mem_charge(sk, skb->truesize); | |
361 | } | |
362 | ||
ed5d7788 | 363 | static void netlink_sock_destruct(struct sock *sk) |
1da177e4 | 364 | { |
3f660d66 HX |
365 | struct netlink_sock *nlk = nlk_sk(sk); |
366 | ||
16b304f3 | 367 | if (nlk->cb_running) { |
ed5d7788 HX |
368 | if (nlk->cb.done) |
369 | nlk->cb.done(&nlk->cb); | |
16b304f3 PS |
370 | module_put(nlk->cb.module); |
371 | kfree_skb(nlk->cb.skb); | |
3f660d66 HX |
372 | } |
373 | ||
1da177e4 LT |
374 | skb_queue_purge(&sk->sk_receive_queue); |
375 | ||
376 | if (!sock_flag(sk, SOCK_DEAD)) { | |
6ac552fd | 377 | printk(KERN_ERR "Freeing alive netlink socket %p\n", sk); |
1da177e4 LT |
378 | return; |
379 | } | |
547b792c IJ |
380 | |
381 | WARN_ON(atomic_read(&sk->sk_rmem_alloc)); | |
382 | WARN_ON(atomic_read(&sk->sk_wmem_alloc)); | |
383 | WARN_ON(nlk_sk(sk)->groups); | |
1da177e4 LT |
384 | } |
385 | ||
707693c8 HX |
386 | static void netlink_sock_destruct_work(struct work_struct *work) |
387 | { | |
388 | struct netlink_sock *nlk = container_of(work, struct netlink_sock, | |
389 | work); | |
390 | ||
ed5d7788 | 391 | sk_free(&nlk->sk); |
707693c8 HX |
392 | } |
393 | ||
6ac552fd PM |
394 | /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on |
395 | * SMP. Look, when several writers sleep and reader wakes them up, all but one | |
1da177e4 LT |
396 | * immediately hit write lock and grab all the cpus. Exclusive sleep solves |
397 | * this, _but_ remember, it adds useless work on UP machines. | |
398 | */ | |
399 | ||
d136f1bd | 400 | void netlink_table_grab(void) |
9a429c49 | 401 | __acquires(nl_table_lock) |
1da177e4 | 402 | { |
d136f1bd JB |
403 | might_sleep(); |
404 | ||
6abd219c | 405 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
406 | |
407 | if (atomic_read(&nl_table_users)) { | |
408 | DECLARE_WAITQUEUE(wait, current); | |
409 | ||
410 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
6ac552fd | 411 | for (;;) { |
1da177e4 LT |
412 | set_current_state(TASK_UNINTERRUPTIBLE); |
413 | if (atomic_read(&nl_table_users) == 0) | |
414 | break; | |
6abd219c | 415 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 416 | schedule(); |
6abd219c | 417 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
418 | } |
419 | ||
420 | __set_current_state(TASK_RUNNING); | |
421 | remove_wait_queue(&nl_table_wait, &wait); | |
422 | } | |
423 | } | |
424 | ||
d136f1bd | 425 | void netlink_table_ungrab(void) |
9a429c49 | 426 | __releases(nl_table_lock) |
1da177e4 | 427 | { |
6abd219c | 428 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
429 | wake_up(&nl_table_wait); |
430 | } | |
431 | ||
6ac552fd | 432 | static inline void |
1da177e4 LT |
433 | netlink_lock_table(void) |
434 | { | |
435 | /* read_lock() synchronizes us to netlink_table_grab */ | |
436 | ||
437 | read_lock(&nl_table_lock); | |
438 | atomic_inc(&nl_table_users); | |
439 | read_unlock(&nl_table_lock); | |
440 | } | |
441 | ||
6ac552fd | 442 | static inline void |
1da177e4 LT |
443 | netlink_unlock_table(void) |
444 | { | |
445 | if (atomic_dec_and_test(&nl_table_users)) | |
446 | wake_up(&nl_table_wait); | |
447 | } | |
448 | ||
e341694e | 449 | struct netlink_compare_arg |
1da177e4 | 450 | { |
c428ecd1 | 451 | possible_net_t pnet; |
e341694e TG |
452 | u32 portid; |
453 | }; | |
1da177e4 | 454 | |
8f2ddaac HX |
455 | /* Doing sizeof directly may yield 4 extra bytes on 64-bit. */ |
456 | #define netlink_compare_arg_len \ | |
457 | (offsetof(struct netlink_compare_arg, portid) + sizeof(u32)) | |
c428ecd1 HX |
458 | |
459 | static inline int netlink_compare(struct rhashtable_compare_arg *arg, | |
460 | const void *ptr) | |
1da177e4 | 461 | { |
c428ecd1 HX |
462 | const struct netlink_compare_arg *x = arg->key; |
463 | const struct netlink_sock *nlk = ptr; | |
1da177e4 | 464 | |
da314c99 | 465 | return nlk->portid != x->portid || |
c428ecd1 HX |
466 | !net_eq(sock_net(&nlk->sk), read_pnet(&x->pnet)); |
467 | } | |
468 | ||
469 | static void netlink_compare_arg_init(struct netlink_compare_arg *arg, | |
470 | struct net *net, u32 portid) | |
471 | { | |
472 | memset(arg, 0, sizeof(*arg)); | |
473 | write_pnet(&arg->pnet, net); | |
474 | arg->portid = portid; | |
1da177e4 LT |
475 | } |
476 | ||
e341694e TG |
477 | static struct sock *__netlink_lookup(struct netlink_table *table, u32 portid, |
478 | struct net *net) | |
1da177e4 | 479 | { |
c428ecd1 | 480 | struct netlink_compare_arg arg; |
1da177e4 | 481 | |
c428ecd1 HX |
482 | netlink_compare_arg_init(&arg, net, portid); |
483 | return rhashtable_lookup_fast(&table->hash, &arg, | |
484 | netlink_rhashtable_params); | |
1da177e4 LT |
485 | } |
486 | ||
c428ecd1 | 487 | static int __netlink_insert(struct netlink_table *table, struct sock *sk) |
c5adde94 | 488 | { |
c428ecd1 | 489 | struct netlink_compare_arg arg; |
c5adde94 | 490 | |
da314c99 | 491 | netlink_compare_arg_init(&arg, sock_net(sk), nlk_sk(sk)->portid); |
c428ecd1 HX |
492 | return rhashtable_lookup_insert_key(&table->hash, &arg, |
493 | &nlk_sk(sk)->node, | |
494 | netlink_rhashtable_params); | |
c5adde94 YX |
495 | } |
496 | ||
e341694e | 497 | static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid) |
1da177e4 | 498 | { |
e341694e TG |
499 | struct netlink_table *table = &nl_table[protocol]; |
500 | struct sock *sk; | |
1da177e4 | 501 | |
e341694e TG |
502 | rcu_read_lock(); |
503 | sk = __netlink_lookup(table, portid, net); | |
504 | if (sk) | |
505 | sock_hold(sk); | |
506 | rcu_read_unlock(); | |
1da177e4 | 507 | |
e341694e | 508 | return sk; |
1da177e4 LT |
509 | } |
510 | ||
90ddc4f0 | 511 | static const struct proto_ops netlink_ops; |
1da177e4 | 512 | |
4277a083 PM |
513 | static void |
514 | netlink_update_listeners(struct sock *sk) | |
515 | { | |
516 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
4277a083 PM |
517 | unsigned long mask; |
518 | unsigned int i; | |
6d772ac5 ED |
519 | struct listeners *listeners; |
520 | ||
521 | listeners = nl_deref_protected(tbl->listeners); | |
522 | if (!listeners) | |
523 | return; | |
4277a083 | 524 | |
b4ff4f04 | 525 | for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
4277a083 | 526 | mask = 0; |
b67bfe0d | 527 | sk_for_each_bound(sk, &tbl->mc_list) { |
b4ff4f04 JB |
528 | if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) |
529 | mask |= nlk_sk(sk)->groups[i]; | |
530 | } | |
6d772ac5 | 531 | listeners->masks[i] = mask; |
4277a083 PM |
532 | } |
533 | /* this function is only called with the netlink table "grabbed", which | |
534 | * makes sure updates are visible before bind or setsockopt return. */ | |
535 | } | |
536 | ||
8ea65f4a | 537 | static int netlink_insert(struct sock *sk, u32 portid) |
1da177e4 | 538 | { |
da12c90e | 539 | struct netlink_table *table = &nl_table[sk->sk_protocol]; |
919d9db9 | 540 | int err; |
1da177e4 | 541 | |
c5adde94 | 542 | lock_sock(sk); |
1da177e4 | 543 | |
da314c99 HX |
544 | err = nlk_sk(sk)->portid == portid ? 0 : -EBUSY; |
545 | if (nlk_sk(sk)->bound) | |
1da177e4 LT |
546 | goto err; |
547 | ||
548 | err = -ENOMEM; | |
97defe1e TG |
549 | if (BITS_PER_LONG > 32 && |
550 | unlikely(atomic_read(&table->hash.nelems) >= UINT_MAX)) | |
1da177e4 LT |
551 | goto err; |
552 | ||
da314c99 | 553 | nlk_sk(sk)->portid = portid; |
e341694e | 554 | sock_hold(sk); |
919d9db9 | 555 | |
c428ecd1 HX |
556 | err = __netlink_insert(table, sk); |
557 | if (err) { | |
4e7c1330 DB |
558 | /* In case the hashtable backend returns with -EBUSY |
559 | * from here, it must not escape to the caller. | |
560 | */ | |
561 | if (unlikely(err == -EBUSY)) | |
562 | err = -EOVERFLOW; | |
c428ecd1 HX |
563 | if (err == -EEXIST) |
564 | err = -EADDRINUSE; | |
c5adde94 | 565 | sock_put(sk); |
1f770c0a | 566 | goto err; |
919d9db9 HX |
567 | } |
568 | ||
da314c99 HX |
569 | /* We need to ensure that the socket is hashed and visible. */ |
570 | smp_wmb(); | |
571 | nlk_sk(sk)->bound = portid; | |
1f770c0a | 572 | |
1da177e4 | 573 | err: |
c5adde94 | 574 | release_sock(sk); |
1da177e4 LT |
575 | return err; |
576 | } | |
577 | ||
578 | static void netlink_remove(struct sock *sk) | |
579 | { | |
e341694e TG |
580 | struct netlink_table *table; |
581 | ||
e341694e | 582 | table = &nl_table[sk->sk_protocol]; |
c428ecd1 HX |
583 | if (!rhashtable_remove_fast(&table->hash, &nlk_sk(sk)->node, |
584 | netlink_rhashtable_params)) { | |
e341694e TG |
585 | WARN_ON(atomic_read(&sk->sk_refcnt) == 1); |
586 | __sock_put(sk); | |
587 | } | |
e341694e | 588 | |
1da177e4 | 589 | netlink_table_grab(); |
b10dcb3b | 590 | if (nlk_sk(sk)->subscriptions) { |
1da177e4 | 591 | __sk_del_bind_node(sk); |
b10dcb3b JB |
592 | netlink_update_listeners(sk); |
593 | } | |
ee1c2442 JB |
594 | if (sk->sk_protocol == NETLINK_GENERIC) |
595 | atomic_inc(&genl_sk_destructing_cnt); | |
1da177e4 LT |
596 | netlink_table_ungrab(); |
597 | } | |
598 | ||
599 | static struct proto netlink_proto = { | |
600 | .name = "NETLINK", | |
601 | .owner = THIS_MODULE, | |
602 | .obj_size = sizeof(struct netlink_sock), | |
603 | }; | |
604 | ||
1b8d7ae4 | 605 | static int __netlink_create(struct net *net, struct socket *sock, |
11aa9c28 EB |
606 | struct mutex *cb_mutex, int protocol, |
607 | int kern) | |
1da177e4 LT |
608 | { |
609 | struct sock *sk; | |
610 | struct netlink_sock *nlk; | |
ab33a171 PM |
611 | |
612 | sock->ops = &netlink_ops; | |
613 | ||
11aa9c28 | 614 | sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto, kern); |
ab33a171 PM |
615 | if (!sk) |
616 | return -ENOMEM; | |
617 | ||
618 | sock_init_data(sock, sk); | |
619 | ||
620 | nlk = nlk_sk(sk); | |
658cb354 | 621 | if (cb_mutex) { |
ffa4d721 | 622 | nlk->cb_mutex = cb_mutex; |
658cb354 | 623 | } else { |
ffa4d721 PM |
624 | nlk->cb_mutex = &nlk->cb_def_mutex; |
625 | mutex_init(nlk->cb_mutex); | |
8a0f5ccf HX |
626 | lockdep_set_class_and_name(nlk->cb_mutex, |
627 | nlk_cb_mutex_keys + protocol, | |
628 | nlk_cb_mutex_key_strings[protocol]); | |
ffa4d721 | 629 | } |
ab33a171 PM |
630 | init_waitqueue_head(&nlk->wait); |
631 | ||
632 | sk->sk_destruct = netlink_sock_destruct; | |
633 | sk->sk_protocol = protocol; | |
634 | return 0; | |
635 | } | |
636 | ||
3f378b68 EP |
637 | static int netlink_create(struct net *net, struct socket *sock, int protocol, |
638 | int kern) | |
ab33a171 PM |
639 | { |
640 | struct module *module = NULL; | |
af65bdfc | 641 | struct mutex *cb_mutex; |
f7fa9b10 | 642 | struct netlink_sock *nlk; |
023e2cfa JB |
643 | int (*bind)(struct net *net, int group); |
644 | void (*unbind)(struct net *net, int group); | |
ab33a171 | 645 | int err = 0; |
1da177e4 LT |
646 | |
647 | sock->state = SS_UNCONNECTED; | |
648 | ||
649 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
650 | return -ESOCKTNOSUPPORT; | |
651 | ||
6ac552fd | 652 | if (protocol < 0 || protocol >= MAX_LINKS) |
1da177e4 LT |
653 | return -EPROTONOSUPPORT; |
654 | ||
77247bbb | 655 | netlink_lock_table(); |
95a5afca | 656 | #ifdef CONFIG_MODULES |
ab33a171 | 657 | if (!nl_table[protocol].registered) { |
77247bbb | 658 | netlink_unlock_table(); |
4fdb3bb7 | 659 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 660 | netlink_lock_table(); |
4fdb3bb7 | 661 | } |
ab33a171 PM |
662 | #endif |
663 | if (nl_table[protocol].registered && | |
664 | try_module_get(nl_table[protocol].module)) | |
665 | module = nl_table[protocol].module; | |
974c37e9 AD |
666 | else |
667 | err = -EPROTONOSUPPORT; | |
af65bdfc | 668 | cb_mutex = nl_table[protocol].cb_mutex; |
03292745 | 669 | bind = nl_table[protocol].bind; |
4f520900 | 670 | unbind = nl_table[protocol].unbind; |
77247bbb | 671 | netlink_unlock_table(); |
4fdb3bb7 | 672 | |
974c37e9 AD |
673 | if (err < 0) |
674 | goto out; | |
675 | ||
11aa9c28 | 676 | err = __netlink_create(net, sock, cb_mutex, protocol, kern); |
6ac552fd | 677 | if (err < 0) |
f7fa9b10 PM |
678 | goto out_module; |
679 | ||
6f756a8c | 680 | local_bh_disable(); |
c1fd3b94 | 681 | sock_prot_inuse_add(net, &netlink_proto, 1); |
6f756a8c DM |
682 | local_bh_enable(); |
683 | ||
f7fa9b10 | 684 | nlk = nlk_sk(sock->sk); |
f7fa9b10 | 685 | nlk->module = module; |
03292745 | 686 | nlk->netlink_bind = bind; |
4f520900 | 687 | nlk->netlink_unbind = unbind; |
ab33a171 PM |
688 | out: |
689 | return err; | |
1da177e4 | 690 | |
ab33a171 PM |
691 | out_module: |
692 | module_put(module); | |
693 | goto out; | |
1da177e4 LT |
694 | } |
695 | ||
21e4902a TG |
696 | static void deferred_put_nlk_sk(struct rcu_head *head) |
697 | { | |
698 | struct netlink_sock *nlk = container_of(head, struct netlink_sock, rcu); | |
ed5d7788 HX |
699 | struct sock *sk = &nlk->sk; |
700 | ||
701 | if (!atomic_dec_and_test(&sk->sk_refcnt)) | |
702 | return; | |
703 | ||
704 | if (nlk->cb_running && nlk->cb.done) { | |
705 | INIT_WORK(&nlk->work, netlink_sock_destruct_work); | |
706 | schedule_work(&nlk->work); | |
707 | return; | |
708 | } | |
21e4902a | 709 | |
ed5d7788 | 710 | sk_free(sk); |
21e4902a TG |
711 | } |
712 | ||
1da177e4 LT |
713 | static int netlink_release(struct socket *sock) |
714 | { | |
715 | struct sock *sk = sock->sk; | |
716 | struct netlink_sock *nlk; | |
717 | ||
718 | if (!sk) | |
719 | return 0; | |
720 | ||
721 | netlink_remove(sk); | |
ac57b3a9 | 722 | sock_orphan(sk); |
1da177e4 LT |
723 | nlk = nlk_sk(sk); |
724 | ||
3f660d66 HX |
725 | /* |
726 | * OK. Socket is unlinked, any packets that arrive now | |
727 | * will be purged. | |
728 | */ | |
1da177e4 | 729 | |
ee1c2442 JB |
730 | /* must not acquire netlink_table_lock in any way again before unbind |
731 | * and notifying genetlink is done as otherwise it might deadlock | |
732 | */ | |
733 | if (nlk->netlink_unbind) { | |
734 | int i; | |
735 | ||
736 | for (i = 0; i < nlk->ngroups; i++) | |
737 | if (test_bit(i, nlk->groups)) | |
738 | nlk->netlink_unbind(sock_net(sk), i + 1); | |
739 | } | |
740 | if (sk->sk_protocol == NETLINK_GENERIC && | |
741 | atomic_dec_return(&genl_sk_destructing_cnt) == 0) | |
742 | wake_up(&genl_sk_destructing_waitq); | |
743 | ||
1da177e4 LT |
744 | sock->sk = NULL; |
745 | wake_up_interruptible_all(&nlk->wait); | |
746 | ||
747 | skb_queue_purge(&sk->sk_write_queue); | |
748 | ||
e2726020 | 749 | if (nlk->portid && nlk->bound) { |
1da177e4 | 750 | struct netlink_notify n = { |
3b1e0a65 | 751 | .net = sock_net(sk), |
1da177e4 | 752 | .protocol = sk->sk_protocol, |
15e47304 | 753 | .portid = nlk->portid, |
1da177e4 | 754 | }; |
efa172f4 | 755 | blocking_notifier_call_chain(&netlink_chain, |
e041c683 | 756 | NETLINK_URELEASE, &n); |
746fac4d | 757 | } |
4fdb3bb7 | 758 | |
5e7c001c | 759 | module_put(nlk->module); |
4fdb3bb7 | 760 | |
aed81560 | 761 | if (netlink_is_kernel(sk)) { |
b10dcb3b | 762 | netlink_table_grab(); |
869e58f8 DL |
763 | BUG_ON(nl_table[sk->sk_protocol].registered == 0); |
764 | if (--nl_table[sk->sk_protocol].registered == 0) { | |
6d772ac5 ED |
765 | struct listeners *old; |
766 | ||
767 | old = nl_deref_protected(nl_table[sk->sk_protocol].listeners); | |
768 | RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL); | |
769 | kfree_rcu(old, rcu); | |
869e58f8 | 770 | nl_table[sk->sk_protocol].module = NULL; |
9785e10a | 771 | nl_table[sk->sk_protocol].bind = NULL; |
4f520900 | 772 | nl_table[sk->sk_protocol].unbind = NULL; |
9785e10a | 773 | nl_table[sk->sk_protocol].flags = 0; |
869e58f8 DL |
774 | nl_table[sk->sk_protocol].registered = 0; |
775 | } | |
b10dcb3b | 776 | netlink_table_ungrab(); |
658cb354 | 777 | } |
77247bbb | 778 | |
f7fa9b10 PM |
779 | kfree(nlk->groups); |
780 | nlk->groups = NULL; | |
781 | ||
3755810c | 782 | local_bh_disable(); |
c1fd3b94 | 783 | sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); |
3755810c | 784 | local_bh_enable(); |
21e4902a | 785 | call_rcu(&nlk->rcu, deferred_put_nlk_sk); |
1da177e4 LT |
786 | return 0; |
787 | } | |
788 | ||
789 | static int netlink_autobind(struct socket *sock) | |
790 | { | |
791 | struct sock *sk = sock->sk; | |
3b1e0a65 | 792 | struct net *net = sock_net(sk); |
da12c90e | 793 | struct netlink_table *table = &nl_table[sk->sk_protocol]; |
15e47304 | 794 | s32 portid = task_tgid_vnr(current); |
1da177e4 | 795 | int err; |
b9fbe709 HX |
796 | s32 rover = -4096; |
797 | bool ok; | |
1da177e4 LT |
798 | |
799 | retry: | |
800 | cond_resched(); | |
e341694e | 801 | rcu_read_lock(); |
b9fbe709 HX |
802 | ok = !__netlink_lookup(table, portid, net); |
803 | rcu_read_unlock(); | |
804 | if (!ok) { | |
e341694e | 805 | /* Bind collision, search negative portid values. */ |
b9fbe709 HX |
806 | if (rover == -4096) |
807 | /* rover will be in range [S32_MIN, -4097] */ | |
808 | rover = S32_MIN + prandom_u32_max(-4096 - S32_MIN); | |
809 | else if (rover >= -4096) | |
e341694e | 810 | rover = -4097; |
b9fbe709 | 811 | portid = rover--; |
e341694e | 812 | goto retry; |
1da177e4 | 813 | } |
1da177e4 | 814 | |
8ea65f4a | 815 | err = netlink_insert(sk, portid); |
1da177e4 LT |
816 | if (err == -EADDRINUSE) |
817 | goto retry; | |
d470e3b4 DM |
818 | |
819 | /* If 2 threads race to autobind, that is fine. */ | |
820 | if (err == -EBUSY) | |
821 | err = 0; | |
822 | ||
823 | return err; | |
1da177e4 LT |
824 | } |
825 | ||
aa4cf945 EB |
826 | /** |
827 | * __netlink_ns_capable - General netlink message capability test | |
828 | * @nsp: NETLINK_CB of the socket buffer holding a netlink command from userspace. | |
829 | * @user_ns: The user namespace of the capability to use | |
830 | * @cap: The capability to use | |
831 | * | |
832 | * Test to see if the opener of the socket we received the message | |
833 | * from had when the netlink socket was created and the sender of the | |
834 | * message has has the capability @cap in the user namespace @user_ns. | |
835 | */ | |
836 | bool __netlink_ns_capable(const struct netlink_skb_parms *nsp, | |
837 | struct user_namespace *user_ns, int cap) | |
838 | { | |
2d7a85f4 EB |
839 | return ((nsp->flags & NETLINK_SKB_DST) || |
840 | file_ns_capable(nsp->sk->sk_socket->file, user_ns, cap)) && | |
841 | ns_capable(user_ns, cap); | |
aa4cf945 EB |
842 | } |
843 | EXPORT_SYMBOL(__netlink_ns_capable); | |
844 | ||
845 | /** | |
846 | * netlink_ns_capable - General netlink message capability test | |
847 | * @skb: socket buffer holding a netlink command from userspace | |
848 | * @user_ns: The user namespace of the capability to use | |
849 | * @cap: The capability to use | |
850 | * | |
851 | * Test to see if the opener of the socket we received the message | |
852 | * from had when the netlink socket was created and the sender of the | |
853 | * message has has the capability @cap in the user namespace @user_ns. | |
854 | */ | |
855 | bool netlink_ns_capable(const struct sk_buff *skb, | |
856 | struct user_namespace *user_ns, int cap) | |
857 | { | |
858 | return __netlink_ns_capable(&NETLINK_CB(skb), user_ns, cap); | |
859 | } | |
860 | EXPORT_SYMBOL(netlink_ns_capable); | |
861 | ||
862 | /** | |
863 | * netlink_capable - Netlink global message capability test | |
864 | * @skb: socket buffer holding a netlink command from userspace | |
865 | * @cap: The capability to use | |
866 | * | |
867 | * Test to see if the opener of the socket we received the message | |
868 | * from had when the netlink socket was created and the sender of the | |
869 | * message has has the capability @cap in all user namespaces. | |
870 | */ | |
871 | bool netlink_capable(const struct sk_buff *skb, int cap) | |
872 | { | |
873 | return netlink_ns_capable(skb, &init_user_ns, cap); | |
874 | } | |
875 | EXPORT_SYMBOL(netlink_capable); | |
876 | ||
877 | /** | |
878 | * netlink_net_capable - Netlink network namespace message capability test | |
879 | * @skb: socket buffer holding a netlink command from userspace | |
880 | * @cap: The capability to use | |
881 | * | |
882 | * Test to see if the opener of the socket we received the message | |
883 | * from had when the netlink socket was created and the sender of the | |
884 | * message has has the capability @cap over the network namespace of | |
885 | * the socket we received the message from. | |
886 | */ | |
887 | bool netlink_net_capable(const struct sk_buff *skb, int cap) | |
888 | { | |
889 | return netlink_ns_capable(skb, sock_net(skb->sk)->user_ns, cap); | |
890 | } | |
891 | EXPORT_SYMBOL(netlink_net_capable); | |
892 | ||
5187cd05 | 893 | static inline int netlink_allowed(const struct socket *sock, unsigned int flag) |
746fac4d | 894 | { |
9785e10a | 895 | return (nl_table[sock->sk->sk_protocol].flags & flag) || |
df008c91 | 896 | ns_capable(sock_net(sock->sk)->user_ns, CAP_NET_ADMIN); |
746fac4d | 897 | } |
1da177e4 | 898 | |
f7fa9b10 PM |
899 | static void |
900 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
901 | { | |
902 | struct netlink_sock *nlk = nlk_sk(sk); | |
903 | ||
904 | if (nlk->subscriptions && !subscriptions) | |
905 | __sk_del_bind_node(sk); | |
906 | else if (!nlk->subscriptions && subscriptions) | |
907 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
908 | nlk->subscriptions = subscriptions; | |
909 | } | |
910 | ||
b4ff4f04 | 911 | static int netlink_realloc_groups(struct sock *sk) |
513c2500 PM |
912 | { |
913 | struct netlink_sock *nlk = nlk_sk(sk); | |
914 | unsigned int groups; | |
b4ff4f04 | 915 | unsigned long *new_groups; |
513c2500 PM |
916 | int err = 0; |
917 | ||
b4ff4f04 JB |
918 | netlink_table_grab(); |
919 | ||
513c2500 | 920 | groups = nl_table[sk->sk_protocol].groups; |
b4ff4f04 | 921 | if (!nl_table[sk->sk_protocol].registered) { |
513c2500 | 922 | err = -ENOENT; |
b4ff4f04 JB |
923 | goto out_unlock; |
924 | } | |
513c2500 | 925 | |
b4ff4f04 JB |
926 | if (nlk->ngroups >= groups) |
927 | goto out_unlock; | |
513c2500 | 928 | |
b4ff4f04 JB |
929 | new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
930 | if (new_groups == NULL) { | |
931 | err = -ENOMEM; | |
932 | goto out_unlock; | |
933 | } | |
6ac552fd | 934 | memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, |
b4ff4f04 JB |
935 | NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); |
936 | ||
937 | nlk->groups = new_groups; | |
513c2500 | 938 | nlk->ngroups = groups; |
b4ff4f04 JB |
939 | out_unlock: |
940 | netlink_table_ungrab(); | |
941 | return err; | |
513c2500 PM |
942 | } |
943 | ||
02c81ab9 | 944 | static void netlink_undo_bind(int group, long unsigned int groups, |
023e2cfa | 945 | struct sock *sk) |
4f520900 | 946 | { |
023e2cfa | 947 | struct netlink_sock *nlk = nlk_sk(sk); |
4f520900 RGB |
948 | int undo; |
949 | ||
950 | if (!nlk->netlink_unbind) | |
951 | return; | |
952 | ||
953 | for (undo = 0; undo < group; undo++) | |
6251edd9 | 954 | if (test_bit(undo, &groups)) |
8b7c36d8 | 955 | nlk->netlink_unbind(sock_net(sk), undo + 1); |
4f520900 RGB |
956 | } |
957 | ||
6ac552fd PM |
958 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, |
959 | int addr_len) | |
1da177e4 LT |
960 | { |
961 | struct sock *sk = sock->sk; | |
3b1e0a65 | 962 | struct net *net = sock_net(sk); |
1da177e4 LT |
963 | struct netlink_sock *nlk = nlk_sk(sk); |
964 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
965 | int err; | |
4f520900 | 966 | long unsigned int groups = nladdr->nl_groups; |
da314c99 | 967 | bool bound; |
746fac4d | 968 | |
4e4b5376 HFS |
969 | if (addr_len < sizeof(struct sockaddr_nl)) |
970 | return -EINVAL; | |
971 | ||
1da177e4 LT |
972 | if (nladdr->nl_family != AF_NETLINK) |
973 | return -EINVAL; | |
974 | ||
975 | /* Only superuser is allowed to listen multicasts */ | |
4f520900 | 976 | if (groups) { |
5187cd05 | 977 | if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV)) |
513c2500 | 978 | return -EPERM; |
b4ff4f04 JB |
979 | err = netlink_realloc_groups(sk); |
980 | if (err) | |
981 | return err; | |
513c2500 | 982 | } |
1da177e4 | 983 | |
da314c99 HX |
984 | bound = nlk->bound; |
985 | if (bound) { | |
986 | /* Ensure nlk->portid is up-to-date. */ | |
987 | smp_rmb(); | |
988 | ||
15e47304 | 989 | if (nladdr->nl_pid != nlk->portid) |
1da177e4 | 990 | return -EINVAL; |
da314c99 | 991 | } |
4f520900 RGB |
992 | |
993 | if (nlk->netlink_bind && groups) { | |
994 | int group; | |
995 | ||
996 | for (group = 0; group < nlk->ngroups; group++) { | |
997 | if (!test_bit(group, &groups)) | |
998 | continue; | |
8b7c36d8 | 999 | err = nlk->netlink_bind(net, group + 1); |
4f520900 RGB |
1000 | if (!err) |
1001 | continue; | |
023e2cfa | 1002 | netlink_undo_bind(group, groups, sk); |
4f520900 RGB |
1003 | return err; |
1004 | } | |
1005 | } | |
1006 | ||
da314c99 HX |
1007 | /* No need for barriers here as we return to user-space without |
1008 | * using any of the bound attributes. | |
1009 | */ | |
1010 | if (!bound) { | |
1da177e4 | 1011 | err = nladdr->nl_pid ? |
8ea65f4a | 1012 | netlink_insert(sk, nladdr->nl_pid) : |
1da177e4 | 1013 | netlink_autobind(sock); |
4f520900 | 1014 | if (err) { |
023e2cfa | 1015 | netlink_undo_bind(nlk->ngroups, groups, sk); |
1da177e4 | 1016 | return err; |
4f520900 | 1017 | } |
1da177e4 LT |
1018 | } |
1019 | ||
4f520900 | 1020 | if (!groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
1da177e4 LT |
1021 | return 0; |
1022 | ||
1023 | netlink_table_grab(); | |
f7fa9b10 | 1024 | netlink_update_subscriptions(sk, nlk->subscriptions + |
4f520900 | 1025 | hweight32(groups) - |
746fac4d | 1026 | hweight32(nlk->groups[0])); |
4f520900 | 1027 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | groups; |
4277a083 | 1028 | netlink_update_listeners(sk); |
1da177e4 LT |
1029 | netlink_table_ungrab(); |
1030 | ||
1031 | return 0; | |
1032 | } | |
1033 | ||
1034 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
1035 | int alen, int flags) | |
1036 | { | |
1037 | int err = 0; | |
1038 | struct sock *sk = sock->sk; | |
1039 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 1040 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
1da177e4 | 1041 | |
6503d961 CG |
1042 | if (alen < sizeof(addr->sa_family)) |
1043 | return -EINVAL; | |
1044 | ||
1da177e4 LT |
1045 | if (addr->sa_family == AF_UNSPEC) { |
1046 | sk->sk_state = NETLINK_UNCONNECTED; | |
15e47304 | 1047 | nlk->dst_portid = 0; |
d629b836 | 1048 | nlk->dst_group = 0; |
1da177e4 LT |
1049 | return 0; |
1050 | } | |
1051 | if (addr->sa_family != AF_NETLINK) | |
1052 | return -EINVAL; | |
1053 | ||
46833a86 | 1054 | if ((nladdr->nl_groups || nladdr->nl_pid) && |
5187cd05 | 1055 | !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND)) |
1da177e4 LT |
1056 | return -EPERM; |
1057 | ||
da314c99 HX |
1058 | /* No need for barriers here as we return to user-space without |
1059 | * using any of the bound attributes. | |
1060 | */ | |
1061 | if (!nlk->bound) | |
1da177e4 LT |
1062 | err = netlink_autobind(sock); |
1063 | ||
1064 | if (err == 0) { | |
1065 | sk->sk_state = NETLINK_CONNECTED; | |
15e47304 | 1066 | nlk->dst_portid = nladdr->nl_pid; |
d629b836 | 1067 | nlk->dst_group = ffs(nladdr->nl_groups); |
1da177e4 LT |
1068 | } |
1069 | ||
1070 | return err; | |
1071 | } | |
1072 | ||
6ac552fd PM |
1073 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, |
1074 | int *addr_len, int peer) | |
1da177e4 LT |
1075 | { |
1076 | struct sock *sk = sock->sk; | |
1077 | struct netlink_sock *nlk = nlk_sk(sk); | |
13cfa97b | 1078 | DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr); |
746fac4d | 1079 | |
1da177e4 LT |
1080 | nladdr->nl_family = AF_NETLINK; |
1081 | nladdr->nl_pad = 0; | |
1082 | *addr_len = sizeof(*nladdr); | |
1083 | ||
1084 | if (peer) { | |
15e47304 | 1085 | nladdr->nl_pid = nlk->dst_portid; |
d629b836 | 1086 | nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
1da177e4 | 1087 | } else { |
15e47304 | 1088 | nladdr->nl_pid = nlk->portid; |
513c2500 | 1089 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
1da177e4 LT |
1090 | } |
1091 | return 0; | |
1092 | } | |
1093 | ||
025c6818 DD |
1094 | static int netlink_ioctl(struct socket *sock, unsigned int cmd, |
1095 | unsigned long arg) | |
1096 | { | |
1097 | /* try to hand this ioctl down to the NIC drivers. | |
1098 | */ | |
1099 | return -ENOIOCTLCMD; | |
1100 | } | |
1101 | ||
15e47304 | 1102 | static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid) |
1da177e4 | 1103 | { |
1da177e4 LT |
1104 | struct sock *sock; |
1105 | struct netlink_sock *nlk; | |
1106 | ||
15e47304 | 1107 | sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, portid); |
1da177e4 LT |
1108 | if (!sock) |
1109 | return ERR_PTR(-ECONNREFUSED); | |
1110 | ||
1111 | /* Don't bother queuing skb if kernel socket has no input function */ | |
1112 | nlk = nlk_sk(sock); | |
cd40b7d3 | 1113 | if (sock->sk_state == NETLINK_CONNECTED && |
15e47304 | 1114 | nlk->dst_portid != nlk_sk(ssk)->portid) { |
1da177e4 LT |
1115 | sock_put(sock); |
1116 | return ERR_PTR(-ECONNREFUSED); | |
1117 | } | |
1118 | return sock; | |
1119 | } | |
1120 | ||
1121 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
1122 | { | |
496ad9aa | 1123 | struct inode *inode = file_inode(filp); |
1da177e4 LT |
1124 | struct sock *sock; |
1125 | ||
1126 | if (!S_ISSOCK(inode->i_mode)) | |
1127 | return ERR_PTR(-ENOTSOCK); | |
1128 | ||
1129 | sock = SOCKET_I(inode)->sk; | |
1130 | if (sock->sk_family != AF_NETLINK) | |
1131 | return ERR_PTR(-EINVAL); | |
1132 | ||
1133 | sock_hold(sock); | |
1134 | return sock; | |
1135 | } | |
1136 | ||
3a36515f PN |
1137 | static struct sk_buff *netlink_alloc_large_skb(unsigned int size, |
1138 | int broadcast) | |
c05cdb1b PNA |
1139 | { |
1140 | struct sk_buff *skb; | |
1141 | void *data; | |
1142 | ||
3a36515f | 1143 | if (size <= NLMSG_GOODSIZE || broadcast) |
c05cdb1b PNA |
1144 | return alloc_skb(size, GFP_KERNEL); |
1145 | ||
3a36515f PN |
1146 | size = SKB_DATA_ALIGN(size) + |
1147 | SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); | |
c05cdb1b PNA |
1148 | |
1149 | data = vmalloc(size); | |
1150 | if (data == NULL) | |
3a36515f | 1151 | return NULL; |
c05cdb1b | 1152 | |
2ea2f62c | 1153 | skb = __build_skb(data, size); |
3a36515f PN |
1154 | if (skb == NULL) |
1155 | vfree(data); | |
2ea2f62c | 1156 | else |
3a36515f | 1157 | skb->destructor = netlink_skb_destructor; |
c05cdb1b PNA |
1158 | |
1159 | return skb; | |
c05cdb1b PNA |
1160 | } |
1161 | ||
1da177e4 LT |
1162 | /* |
1163 | * Attach a skb to a netlink socket. | |
1164 | * The caller must hold a reference to the destination socket. On error, the | |
1165 | * reference is dropped. The skb is not send to the destination, just all | |
1166 | * all error checks are performed and memory in the queue is reserved. | |
1167 | * Return values: | |
1168 | * < 0: error. skb freed, reference to sock dropped. | |
1169 | * 0: continue | |
1170 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
1171 | */ | |
9457afee | 1172 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
c3d8d1e3 | 1173 | long *timeo, struct sock *ssk) |
1da177e4 LT |
1174 | { |
1175 | struct netlink_sock *nlk; | |
1176 | ||
1177 | nlk = nlk_sk(sk); | |
1178 | ||
5fd96123 | 1179 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || |
d1b4c689 | 1180 | test_bit(NETLINK_S_CONGESTED, &nlk->state))) { |
1da177e4 | 1181 | DECLARE_WAITQUEUE(wait, current); |
c3d8d1e3 | 1182 | if (!*timeo) { |
aed81560 | 1183 | if (!ssk || netlink_is_kernel(ssk)) |
1da177e4 LT |
1184 | netlink_overrun(sk); |
1185 | sock_put(sk); | |
1186 | kfree_skb(skb); | |
1187 | return -EAGAIN; | |
1188 | } | |
1189 | ||
1190 | __set_current_state(TASK_INTERRUPTIBLE); | |
1191 | add_wait_queue(&nlk->wait, &wait); | |
1192 | ||
1193 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
cc3a572f | 1194 | test_bit(NETLINK_S_CONGESTED, &nlk->state)) && |
1da177e4 | 1195 | !sock_flag(sk, SOCK_DEAD)) |
c3d8d1e3 | 1196 | *timeo = schedule_timeout(*timeo); |
1da177e4 LT |
1197 | |
1198 | __set_current_state(TASK_RUNNING); | |
1199 | remove_wait_queue(&nlk->wait, &wait); | |
1200 | sock_put(sk); | |
1201 | ||
1202 | if (signal_pending(current)) { | |
1203 | kfree_skb(skb); | |
c3d8d1e3 | 1204 | return sock_intr_errno(*timeo); |
1da177e4 LT |
1205 | } |
1206 | return 1; | |
1207 | } | |
cf0a018a | 1208 | netlink_skb_set_owner_r(skb, sk); |
1da177e4 LT |
1209 | return 0; |
1210 | } | |
1211 | ||
4a7e7c2a | 1212 | static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 1213 | { |
1da177e4 LT |
1214 | int len = skb->len; |
1215 | ||
bcbde0d4 DB |
1216 | netlink_deliver_tap(skb); |
1217 | ||
d1b4c689 | 1218 | skb_queue_tail(&sk->sk_receive_queue, skb); |
676d2369 | 1219 | sk->sk_data_ready(sk); |
4a7e7c2a ED |
1220 | return len; |
1221 | } | |
1222 | ||
1223 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb) | |
1224 | { | |
1225 | int len = __netlink_sendskb(sk, skb); | |
1226 | ||
1da177e4 LT |
1227 | sock_put(sk); |
1228 | return len; | |
1229 | } | |
1230 | ||
1231 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
1232 | { | |
1233 | kfree_skb(skb); | |
1234 | sock_put(sk); | |
1235 | } | |
1236 | ||
b57ef81f | 1237 | static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation) |
1da177e4 LT |
1238 | { |
1239 | int delta; | |
1240 | ||
1298ca46 | 1241 | WARN_ON(skb->sk != NULL); |
4305b541 | 1242 | delta = skb->end - skb->tail; |
c05cdb1b | 1243 | if (is_vmalloc_addr(skb->head) || delta * 2 < skb->truesize) |
1da177e4 LT |
1244 | return skb; |
1245 | ||
1246 | if (skb_shared(skb)) { | |
1247 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
1248 | if (!nskb) | |
1249 | return skb; | |
8460c00f | 1250 | consume_skb(skb); |
1da177e4 LT |
1251 | skb = nskb; |
1252 | } | |
1253 | ||
158f323b ED |
1254 | pskb_expand_head(skb, 0, -delta, |
1255 | (allocation & ~__GFP_DIRECT_RECLAIM) | | |
1256 | __GFP_NOWARN | __GFP_NORETRY); | |
1da177e4 LT |
1257 | return skb; |
1258 | } | |
1259 | ||
3fbc2905 EB |
1260 | static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb, |
1261 | struct sock *ssk) | |
cd40b7d3 DL |
1262 | { |
1263 | int ret; | |
1264 | struct netlink_sock *nlk = nlk_sk(sk); | |
1265 | ||
1266 | ret = -ECONNREFUSED; | |
1267 | if (nlk->netlink_rcv != NULL) { | |
1268 | ret = skb->len; | |
cf0a018a | 1269 | netlink_skb_set_owner_r(skb, sk); |
e32123e5 | 1270 | NETLINK_CB(skb).sk = ssk; |
73bfd370 | 1271 | netlink_deliver_tap_kernel(sk, ssk, skb); |
cd40b7d3 | 1272 | nlk->netlink_rcv(skb); |
bfb253c9 ED |
1273 | consume_skb(skb); |
1274 | } else { | |
1275 | kfree_skb(skb); | |
cd40b7d3 | 1276 | } |
cd40b7d3 DL |
1277 | sock_put(sk); |
1278 | return ret; | |
1279 | } | |
1280 | ||
1281 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, | |
15e47304 | 1282 | u32 portid, int nonblock) |
1da177e4 LT |
1283 | { |
1284 | struct sock *sk; | |
1285 | int err; | |
1286 | long timeo; | |
1287 | ||
1288 | skb = netlink_trim(skb, gfp_any()); | |
1289 | ||
1290 | timeo = sock_sndtimeo(ssk, nonblock); | |
1291 | retry: | |
15e47304 | 1292 | sk = netlink_getsockbyportid(ssk, portid); |
1da177e4 LT |
1293 | if (IS_ERR(sk)) { |
1294 | kfree_skb(skb); | |
1295 | return PTR_ERR(sk); | |
1296 | } | |
cd40b7d3 | 1297 | if (netlink_is_kernel(sk)) |
3fbc2905 | 1298 | return netlink_unicast_kernel(sk, skb, ssk); |
cd40b7d3 | 1299 | |
b1153f29 | 1300 | if (sk_filter(sk, skb)) { |
84874607 | 1301 | err = skb->len; |
b1153f29 SH |
1302 | kfree_skb(skb); |
1303 | sock_put(sk); | |
1304 | return err; | |
1305 | } | |
1306 | ||
9457afee | 1307 | err = netlink_attachskb(sk, skb, &timeo, ssk); |
1da177e4 LT |
1308 | if (err == 1) |
1309 | goto retry; | |
1310 | if (err) | |
1311 | return err; | |
1312 | ||
7ee015e0 | 1313 | return netlink_sendskb(sk, skb); |
1da177e4 | 1314 | } |
6ac552fd | 1315 | EXPORT_SYMBOL(netlink_unicast); |
1da177e4 | 1316 | |
4277a083 PM |
1317 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
1318 | { | |
1319 | int res = 0; | |
5c398dc8 | 1320 | struct listeners *listeners; |
4277a083 | 1321 | |
aed81560 | 1322 | BUG_ON(!netlink_is_kernel(sk)); |
b4ff4f04 JB |
1323 | |
1324 | rcu_read_lock(); | |
1325 | listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); | |
1326 | ||
6d772ac5 | 1327 | if (listeners && group - 1 < nl_table[sk->sk_protocol].groups) |
5c398dc8 | 1328 | res = test_bit(group - 1, listeners->masks); |
b4ff4f04 JB |
1329 | |
1330 | rcu_read_unlock(); | |
1331 | ||
4277a083 PM |
1332 | return res; |
1333 | } | |
1334 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
1335 | ||
b57ef81f | 1336 | static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) |
1da177e4 LT |
1337 | { |
1338 | struct netlink_sock *nlk = nlk_sk(sk); | |
1339 | ||
1340 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
cc3a572f | 1341 | !test_bit(NETLINK_S_CONGESTED, &nlk->state)) { |
cf0a018a | 1342 | netlink_skb_set_owner_r(skb, sk); |
4a7e7c2a | 1343 | __netlink_sendskb(sk, skb); |
2c645800 | 1344 | return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1); |
1da177e4 LT |
1345 | } |
1346 | return -1; | |
1347 | } | |
1348 | ||
1349 | struct netlink_broadcast_data { | |
1350 | struct sock *exclude_sk; | |
b4b51029 | 1351 | struct net *net; |
15e47304 | 1352 | u32 portid; |
1da177e4 LT |
1353 | u32 group; |
1354 | int failure; | |
ff491a73 | 1355 | int delivery_failure; |
1da177e4 LT |
1356 | int congested; |
1357 | int delivered; | |
7d877f3b | 1358 | gfp_t allocation; |
1da177e4 | 1359 | struct sk_buff *skb, *skb2; |
910a7e90 EB |
1360 | int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data); |
1361 | void *tx_data; | |
1da177e4 LT |
1362 | }; |
1363 | ||
46c9521f RR |
1364 | static void do_one_broadcast(struct sock *sk, |
1365 | struct netlink_broadcast_data *p) | |
1da177e4 LT |
1366 | { |
1367 | struct netlink_sock *nlk = nlk_sk(sk); | |
1368 | int val; | |
1369 | ||
1370 | if (p->exclude_sk == sk) | |
46c9521f | 1371 | return; |
1da177e4 | 1372 | |
15e47304 | 1373 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
f7fa9b10 | 1374 | !test_bit(p->group - 1, nlk->groups)) |
46c9521f | 1375 | return; |
1da177e4 | 1376 | |
59324cf3 ND |
1377 | if (!net_eq(sock_net(sk), p->net)) { |
1378 | if (!(nlk->flags & NETLINK_F_LISTEN_ALL_NSID)) | |
1379 | return; | |
1380 | ||
1381 | if (!peernet_has_id(sock_net(sk), p->net)) | |
1382 | return; | |
1383 | ||
1384 | if (!file_ns_capable(sk->sk_socket->file, p->net->user_ns, | |
1385 | CAP_NET_BROADCAST)) | |
1386 | return; | |
1387 | } | |
b4b51029 | 1388 | |
1da177e4 LT |
1389 | if (p->failure) { |
1390 | netlink_overrun(sk); | |
46c9521f | 1391 | return; |
1da177e4 LT |
1392 | } |
1393 | ||
1394 | sock_hold(sk); | |
1395 | if (p->skb2 == NULL) { | |
68acc024 | 1396 | if (skb_shared(p->skb)) { |
1da177e4 LT |
1397 | p->skb2 = skb_clone(p->skb, p->allocation); |
1398 | } else { | |
68acc024 TC |
1399 | p->skb2 = skb_get(p->skb); |
1400 | /* | |
1401 | * skb ownership may have been set when | |
1402 | * delivered to a previous socket. | |
1403 | */ | |
1404 | skb_orphan(p->skb2); | |
1da177e4 LT |
1405 | } |
1406 | } | |
1407 | if (p->skb2 == NULL) { | |
1408 | netlink_overrun(sk); | |
1409 | /* Clone failed. Notify ALL listeners. */ | |
1410 | p->failure = 1; | |
cc3a572f | 1411 | if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR) |
be0c22a4 | 1412 | p->delivery_failure = 1; |
59324cf3 ND |
1413 | goto out; |
1414 | } | |
1415 | if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) { | |
910a7e90 EB |
1416 | kfree_skb(p->skb2); |
1417 | p->skb2 = NULL; | |
59324cf3 ND |
1418 | goto out; |
1419 | } | |
1420 | if (sk_filter(sk, p->skb2)) { | |
b1153f29 SH |
1421 | kfree_skb(p->skb2); |
1422 | p->skb2 = NULL; | |
59324cf3 ND |
1423 | goto out; |
1424 | } | |
1425 | NETLINK_CB(p->skb2).nsid = peernet2id(sock_net(sk), p->net); | |
1426 | NETLINK_CB(p->skb2).nsid_is_set = true; | |
1427 | val = netlink_broadcast_deliver(sk, p->skb2); | |
1428 | if (val < 0) { | |
1da177e4 | 1429 | netlink_overrun(sk); |
cc3a572f | 1430 | if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR) |
be0c22a4 | 1431 | p->delivery_failure = 1; |
1da177e4 LT |
1432 | } else { |
1433 | p->congested |= val; | |
1434 | p->delivered = 1; | |
1435 | p->skb2 = NULL; | |
1436 | } | |
59324cf3 | 1437 | out: |
1da177e4 | 1438 | sock_put(sk); |
1da177e4 LT |
1439 | } |
1440 | ||
15e47304 | 1441 | int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 portid, |
910a7e90 EB |
1442 | u32 group, gfp_t allocation, |
1443 | int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data), | |
1444 | void *filter_data) | |
1da177e4 | 1445 | { |
3b1e0a65 | 1446 | struct net *net = sock_net(ssk); |
1da177e4 | 1447 | struct netlink_broadcast_data info; |
1da177e4 LT |
1448 | struct sock *sk; |
1449 | ||
1450 | skb = netlink_trim(skb, allocation); | |
1451 | ||
1452 | info.exclude_sk = ssk; | |
b4b51029 | 1453 | info.net = net; |
15e47304 | 1454 | info.portid = portid; |
1da177e4 LT |
1455 | info.group = group; |
1456 | info.failure = 0; | |
ff491a73 | 1457 | info.delivery_failure = 0; |
1da177e4 LT |
1458 | info.congested = 0; |
1459 | info.delivered = 0; | |
1460 | info.allocation = allocation; | |
1461 | info.skb = skb; | |
1462 | info.skb2 = NULL; | |
910a7e90 EB |
1463 | info.tx_filter = filter; |
1464 | info.tx_data = filter_data; | |
1da177e4 LT |
1465 | |
1466 | /* While we sleep in clone, do not allow to change socket list */ | |
1467 | ||
1468 | netlink_lock_table(); | |
1469 | ||
b67bfe0d | 1470 | sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
1da177e4 LT |
1471 | do_one_broadcast(sk, &info); |
1472 | ||
70d4bf6d | 1473 | consume_skb(skb); |
aa1c6a6f | 1474 | |
1da177e4 LT |
1475 | netlink_unlock_table(); |
1476 | ||
70d4bf6d NH |
1477 | if (info.delivery_failure) { |
1478 | kfree_skb(info.skb2); | |
ff491a73 | 1479 | return -ENOBUFS; |
658cb354 ED |
1480 | } |
1481 | consume_skb(info.skb2); | |
ff491a73 | 1482 | |
1da177e4 | 1483 | if (info.delivered) { |
d0164adc | 1484 | if (info.congested && gfpflags_allow_blocking(allocation)) |
1da177e4 LT |
1485 | yield(); |
1486 | return 0; | |
1487 | } | |
1da177e4 LT |
1488 | return -ESRCH; |
1489 | } | |
910a7e90 EB |
1490 | EXPORT_SYMBOL(netlink_broadcast_filtered); |
1491 | ||
15e47304 | 1492 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 portid, |
910a7e90 EB |
1493 | u32 group, gfp_t allocation) |
1494 | { | |
15e47304 | 1495 | return netlink_broadcast_filtered(ssk, skb, portid, group, allocation, |
910a7e90 EB |
1496 | NULL, NULL); |
1497 | } | |
6ac552fd | 1498 | EXPORT_SYMBOL(netlink_broadcast); |
1da177e4 LT |
1499 | |
1500 | struct netlink_set_err_data { | |
1501 | struct sock *exclude_sk; | |
15e47304 | 1502 | u32 portid; |
1da177e4 LT |
1503 | u32 group; |
1504 | int code; | |
1505 | }; | |
1506 | ||
b57ef81f | 1507 | static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p) |
1da177e4 LT |
1508 | { |
1509 | struct netlink_sock *nlk = nlk_sk(sk); | |
1a50307b | 1510 | int ret = 0; |
1da177e4 LT |
1511 | |
1512 | if (sk == p->exclude_sk) | |
1513 | goto out; | |
1514 | ||
09ad9bc7 | 1515 | if (!net_eq(sock_net(sk), sock_net(p->exclude_sk))) |
b4b51029 EB |
1516 | goto out; |
1517 | ||
15e47304 | 1518 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
f7fa9b10 | 1519 | !test_bit(p->group - 1, nlk->groups)) |
1da177e4 LT |
1520 | goto out; |
1521 | ||
cc3a572f | 1522 | if (p->code == ENOBUFS && nlk->flags & NETLINK_F_RECV_NO_ENOBUFS) { |
1a50307b PNA |
1523 | ret = 1; |
1524 | goto out; | |
1525 | } | |
1526 | ||
1da177e4 LT |
1527 | sk->sk_err = p->code; |
1528 | sk->sk_error_report(sk); | |
1529 | out: | |
1a50307b | 1530 | return ret; |
1da177e4 LT |
1531 | } |
1532 | ||
4843b93c PNA |
1533 | /** |
1534 | * netlink_set_err - report error to broadcast listeners | |
1535 | * @ssk: the kernel netlink socket, as returned by netlink_kernel_create() | |
15e47304 | 1536 | * @portid: the PORTID of a process that we want to skip (if any) |
840e93f2 | 1537 | * @group: the broadcast group that will notice the error |
4843b93c | 1538 | * @code: error code, must be negative (as usual in kernelspace) |
1a50307b PNA |
1539 | * |
1540 | * This function returns the number of broadcast listeners that have set the | |
cc3a572f | 1541 | * NETLINK_NO_ENOBUFS socket option. |
4843b93c | 1542 | */ |
15e47304 | 1543 | int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code) |
1da177e4 LT |
1544 | { |
1545 | struct netlink_set_err_data info; | |
1da177e4 | 1546 | struct sock *sk; |
1a50307b | 1547 | int ret = 0; |
1da177e4 LT |
1548 | |
1549 | info.exclude_sk = ssk; | |
15e47304 | 1550 | info.portid = portid; |
1da177e4 | 1551 | info.group = group; |
4843b93c PNA |
1552 | /* sk->sk_err wants a positive error value */ |
1553 | info.code = -code; | |
1da177e4 LT |
1554 | |
1555 | read_lock(&nl_table_lock); | |
1556 | ||
b67bfe0d | 1557 | sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
1a50307b | 1558 | ret += do_one_set_err(sk, &info); |
1da177e4 LT |
1559 | |
1560 | read_unlock(&nl_table_lock); | |
1a50307b | 1561 | return ret; |
1da177e4 | 1562 | } |
dd5b6ce6 | 1563 | EXPORT_SYMBOL(netlink_set_err); |
1da177e4 | 1564 | |
84659eb5 JB |
1565 | /* must be called with netlink table grabbed */ |
1566 | static void netlink_update_socket_mc(struct netlink_sock *nlk, | |
1567 | unsigned int group, | |
1568 | int is_new) | |
1569 | { | |
1570 | int old, new = !!is_new, subscriptions; | |
1571 | ||
1572 | old = test_bit(group - 1, nlk->groups); | |
1573 | subscriptions = nlk->subscriptions - old + new; | |
1574 | if (new) | |
1575 | __set_bit(group - 1, nlk->groups); | |
1576 | else | |
1577 | __clear_bit(group - 1, nlk->groups); | |
1578 | netlink_update_subscriptions(&nlk->sk, subscriptions); | |
1579 | netlink_update_listeners(&nlk->sk); | |
1580 | } | |
1581 | ||
9a4595bc | 1582 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
b7058842 | 1583 | char __user *optval, unsigned int optlen) |
9a4595bc PM |
1584 | { |
1585 | struct sock *sk = sock->sk; | |
1586 | struct netlink_sock *nlk = nlk_sk(sk); | |
eb496534 JB |
1587 | unsigned int val = 0; |
1588 | int err; | |
9a4595bc PM |
1589 | |
1590 | if (level != SOL_NETLINK) | |
1591 | return -ENOPROTOOPT; | |
1592 | ||
d1b4c689 | 1593 | if (optlen >= sizeof(int) && |
eb496534 | 1594 | get_user(val, (unsigned int __user *)optval)) |
9a4595bc PM |
1595 | return -EFAULT; |
1596 | ||
1597 | switch (optname) { | |
1598 | case NETLINK_PKTINFO: | |
1599 | if (val) | |
cc3a572f | 1600 | nlk->flags |= NETLINK_F_RECV_PKTINFO; |
9a4595bc | 1601 | else |
cc3a572f | 1602 | nlk->flags &= ~NETLINK_F_RECV_PKTINFO; |
9a4595bc PM |
1603 | err = 0; |
1604 | break; | |
1605 | case NETLINK_ADD_MEMBERSHIP: | |
1606 | case NETLINK_DROP_MEMBERSHIP: { | |
5187cd05 | 1607 | if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV)) |
9a4595bc | 1608 | return -EPERM; |
b4ff4f04 JB |
1609 | err = netlink_realloc_groups(sk); |
1610 | if (err) | |
1611 | return err; | |
9a4595bc PM |
1612 | if (!val || val - 1 >= nlk->ngroups) |
1613 | return -EINVAL; | |
7774d5e0 | 1614 | if (optname == NETLINK_ADD_MEMBERSHIP && nlk->netlink_bind) { |
023e2cfa | 1615 | err = nlk->netlink_bind(sock_net(sk), val); |
4f520900 RGB |
1616 | if (err) |
1617 | return err; | |
1618 | } | |
9a4595bc | 1619 | netlink_table_grab(); |
84659eb5 JB |
1620 | netlink_update_socket_mc(nlk, val, |
1621 | optname == NETLINK_ADD_MEMBERSHIP); | |
9a4595bc | 1622 | netlink_table_ungrab(); |
7774d5e0 | 1623 | if (optname == NETLINK_DROP_MEMBERSHIP && nlk->netlink_unbind) |
023e2cfa | 1624 | nlk->netlink_unbind(sock_net(sk), val); |
03292745 | 1625 | |
9a4595bc PM |
1626 | err = 0; |
1627 | break; | |
1628 | } | |
be0c22a4 PNA |
1629 | case NETLINK_BROADCAST_ERROR: |
1630 | if (val) | |
cc3a572f | 1631 | nlk->flags |= NETLINK_F_BROADCAST_SEND_ERROR; |
be0c22a4 | 1632 | else |
cc3a572f | 1633 | nlk->flags &= ~NETLINK_F_BROADCAST_SEND_ERROR; |
be0c22a4 PNA |
1634 | err = 0; |
1635 | break; | |
38938bfe PNA |
1636 | case NETLINK_NO_ENOBUFS: |
1637 | if (val) { | |
cc3a572f ND |
1638 | nlk->flags |= NETLINK_F_RECV_NO_ENOBUFS; |
1639 | clear_bit(NETLINK_S_CONGESTED, &nlk->state); | |
38938bfe | 1640 | wake_up_interruptible(&nlk->wait); |
658cb354 | 1641 | } else { |
cc3a572f | 1642 | nlk->flags &= ~NETLINK_F_RECV_NO_ENOBUFS; |
658cb354 | 1643 | } |
38938bfe PNA |
1644 | err = 0; |
1645 | break; | |
59324cf3 ND |
1646 | case NETLINK_LISTEN_ALL_NSID: |
1647 | if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_BROADCAST)) | |
1648 | return -EPERM; | |
1649 | ||
1650 | if (val) | |
1651 | nlk->flags |= NETLINK_F_LISTEN_ALL_NSID; | |
1652 | else | |
1653 | nlk->flags &= ~NETLINK_F_LISTEN_ALL_NSID; | |
1654 | err = 0; | |
1655 | break; | |
0a6a3a23 CR |
1656 | case NETLINK_CAP_ACK: |
1657 | if (val) | |
1658 | nlk->flags |= NETLINK_F_CAP_ACK; | |
1659 | else | |
1660 | nlk->flags &= ~NETLINK_F_CAP_ACK; | |
1661 | err = 0; | |
1662 | break; | |
9a4595bc PM |
1663 | default: |
1664 | err = -ENOPROTOOPT; | |
1665 | } | |
1666 | return err; | |
1667 | } | |
1668 | ||
1669 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
746fac4d | 1670 | char __user *optval, int __user *optlen) |
9a4595bc PM |
1671 | { |
1672 | struct sock *sk = sock->sk; | |
1673 | struct netlink_sock *nlk = nlk_sk(sk); | |
1674 | int len, val, err; | |
1675 | ||
1676 | if (level != SOL_NETLINK) | |
1677 | return -ENOPROTOOPT; | |
1678 | ||
1679 | if (get_user(len, optlen)) | |
1680 | return -EFAULT; | |
1681 | if (len < 0) | |
1682 | return -EINVAL; | |
1683 | ||
1684 | switch (optname) { | |
1685 | case NETLINK_PKTINFO: | |
1686 | if (len < sizeof(int)) | |
1687 | return -EINVAL; | |
1688 | len = sizeof(int); | |
cc3a572f | 1689 | val = nlk->flags & NETLINK_F_RECV_PKTINFO ? 1 : 0; |
a27b58fe HC |
1690 | if (put_user(len, optlen) || |
1691 | put_user(val, optval)) | |
1692 | return -EFAULT; | |
9a4595bc PM |
1693 | err = 0; |
1694 | break; | |
be0c22a4 PNA |
1695 | case NETLINK_BROADCAST_ERROR: |
1696 | if (len < sizeof(int)) | |
1697 | return -EINVAL; | |
1698 | len = sizeof(int); | |
cc3a572f | 1699 | val = nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR ? 1 : 0; |
be0c22a4 PNA |
1700 | if (put_user(len, optlen) || |
1701 | put_user(val, optval)) | |
1702 | return -EFAULT; | |
1703 | err = 0; | |
1704 | break; | |
38938bfe PNA |
1705 | case NETLINK_NO_ENOBUFS: |
1706 | if (len < sizeof(int)) | |
1707 | return -EINVAL; | |
1708 | len = sizeof(int); | |
cc3a572f | 1709 | val = nlk->flags & NETLINK_F_RECV_NO_ENOBUFS ? 1 : 0; |
38938bfe PNA |
1710 | if (put_user(len, optlen) || |
1711 | put_user(val, optval)) | |
1712 | return -EFAULT; | |
1713 | err = 0; | |
1714 | break; | |
b42be38b DH |
1715 | case NETLINK_LIST_MEMBERSHIPS: { |
1716 | int pos, idx, shift; | |
1717 | ||
1718 | err = 0; | |
47191d65 | 1719 | netlink_lock_table(); |
b42be38b DH |
1720 | for (pos = 0; pos * 8 < nlk->ngroups; pos += sizeof(u32)) { |
1721 | if (len - pos < sizeof(u32)) | |
1722 | break; | |
1723 | ||
1724 | idx = pos / sizeof(unsigned long); | |
1725 | shift = (pos % sizeof(unsigned long)) * 8; | |
1726 | if (put_user((u32)(nlk->groups[idx] >> shift), | |
1727 | (u32 __user *)(optval + pos))) { | |
1728 | err = -EFAULT; | |
1729 | break; | |
1730 | } | |
1731 | } | |
1732 | if (put_user(ALIGN(nlk->ngroups / 8, sizeof(u32)), optlen)) | |
1733 | err = -EFAULT; | |
47191d65 | 1734 | netlink_unlock_table(); |
b42be38b DH |
1735 | break; |
1736 | } | |
0a6a3a23 CR |
1737 | case NETLINK_CAP_ACK: |
1738 | if (len < sizeof(int)) | |
1739 | return -EINVAL; | |
1740 | len = sizeof(int); | |
1741 | val = nlk->flags & NETLINK_F_CAP_ACK ? 1 : 0; | |
1742 | if (put_user(len, optlen) || | |
1743 | put_user(val, optval)) | |
1744 | return -EFAULT; | |
1745 | err = 0; | |
1746 | break; | |
9a4595bc PM |
1747 | default: |
1748 | err = -ENOPROTOOPT; | |
1749 | } | |
1750 | return err; | |
1751 | } | |
1752 | ||
1753 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
1754 | { | |
1755 | struct nl_pktinfo info; | |
1756 | ||
1757 | info.group = NETLINK_CB(skb).dst_group; | |
1758 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
1759 | } | |
1760 | ||
59324cf3 ND |
1761 | static void netlink_cmsg_listen_all_nsid(struct sock *sk, struct msghdr *msg, |
1762 | struct sk_buff *skb) | |
1763 | { | |
1764 | if (!NETLINK_CB(skb).nsid_is_set) | |
1765 | return; | |
1766 | ||
1767 | put_cmsg(msg, SOL_NETLINK, NETLINK_LISTEN_ALL_NSID, sizeof(int), | |
1768 | &NETLINK_CB(skb).nsid); | |
1769 | } | |
1770 | ||
1b784140 | 1771 | static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) |
1da177e4 | 1772 | { |
1da177e4 LT |
1773 | struct sock *sk = sock->sk; |
1774 | struct netlink_sock *nlk = nlk_sk(sk); | |
342dfc30 | 1775 | DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name); |
15e47304 | 1776 | u32 dst_portid; |
d629b836 | 1777 | u32 dst_group; |
1da177e4 LT |
1778 | struct sk_buff *skb; |
1779 | int err; | |
1780 | struct scm_cookie scm; | |
2d7a85f4 | 1781 | u32 netlink_skb_flags = 0; |
1da177e4 LT |
1782 | |
1783 | if (msg->msg_flags&MSG_OOB) | |
1784 | return -EOPNOTSUPP; | |
1785 | ||
7cc05662 | 1786 | err = scm_send(sock, msg, &scm, true); |
1da177e4 LT |
1787 | if (err < 0) |
1788 | return err; | |
1789 | ||
1790 | if (msg->msg_namelen) { | |
b47030c7 | 1791 | err = -EINVAL; |
1da177e4 | 1792 | if (addr->nl_family != AF_NETLINK) |
b47030c7 | 1793 | goto out; |
15e47304 | 1794 | dst_portid = addr->nl_pid; |
d629b836 | 1795 | dst_group = ffs(addr->nl_groups); |
b47030c7 | 1796 | err = -EPERM; |
15e47304 | 1797 | if ((dst_group || dst_portid) && |
5187cd05 | 1798 | !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND)) |
b47030c7 | 1799 | goto out; |
2d7a85f4 | 1800 | netlink_skb_flags |= NETLINK_SKB_DST; |
1da177e4 | 1801 | } else { |
15e47304 | 1802 | dst_portid = nlk->dst_portid; |
d629b836 | 1803 | dst_group = nlk->dst_group; |
1da177e4 LT |
1804 | } |
1805 | ||
da314c99 | 1806 | if (!nlk->bound) { |
1da177e4 LT |
1807 | err = netlink_autobind(sock); |
1808 | if (err) | |
1809 | goto out; | |
da314c99 HX |
1810 | } else { |
1811 | /* Ensure nlk is hashed and visible. */ | |
1812 | smp_rmb(); | |
1da177e4 LT |
1813 | } |
1814 | ||
1815 | err = -EMSGSIZE; | |
1816 | if (len > sk->sk_sndbuf - 32) | |
1817 | goto out; | |
1818 | err = -ENOBUFS; | |
3a36515f | 1819 | skb = netlink_alloc_large_skb(len, dst_group); |
6ac552fd | 1820 | if (skb == NULL) |
1da177e4 LT |
1821 | goto out; |
1822 | ||
15e47304 | 1823 | NETLINK_CB(skb).portid = nlk->portid; |
d629b836 | 1824 | NETLINK_CB(skb).dst_group = dst_group; |
7cc05662 | 1825 | NETLINK_CB(skb).creds = scm.creds; |
2d7a85f4 | 1826 | NETLINK_CB(skb).flags = netlink_skb_flags; |
1da177e4 | 1827 | |
1da177e4 | 1828 | err = -EFAULT; |
6ce8e9ce | 1829 | if (memcpy_from_msg(skb_put(skb, len), msg, len)) { |
1da177e4 LT |
1830 | kfree_skb(skb); |
1831 | goto out; | |
1832 | } | |
1833 | ||
1834 | err = security_netlink_send(sk, skb); | |
1835 | if (err) { | |
1836 | kfree_skb(skb); | |
1837 | goto out; | |
1838 | } | |
1839 | ||
d629b836 | 1840 | if (dst_group) { |
1da177e4 | 1841 | atomic_inc(&skb->users); |
15e47304 | 1842 | netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL); |
1da177e4 | 1843 | } |
15e47304 | 1844 | err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags&MSG_DONTWAIT); |
1da177e4 LT |
1845 | |
1846 | out: | |
7cc05662 | 1847 | scm_destroy(&scm); |
1da177e4 LT |
1848 | return err; |
1849 | } | |
1850 | ||
1b784140 | 1851 | static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, |
1da177e4 LT |
1852 | int flags) |
1853 | { | |
1da177e4 LT |
1854 | struct scm_cookie scm; |
1855 | struct sock *sk = sock->sk; | |
1856 | struct netlink_sock *nlk = nlk_sk(sk); | |
1857 | int noblock = flags&MSG_DONTWAIT; | |
1858 | size_t copied; | |
68d6ac6d | 1859 | struct sk_buff *skb, *data_skb; |
b44d211e | 1860 | int err, ret; |
1da177e4 LT |
1861 | |
1862 | if (flags&MSG_OOB) | |
1863 | return -EOPNOTSUPP; | |
1864 | ||
1865 | copied = 0; | |
1866 | ||
6ac552fd PM |
1867 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
1868 | if (skb == NULL) | |
1da177e4 LT |
1869 | goto out; |
1870 | ||
68d6ac6d JB |
1871 | data_skb = skb; |
1872 | ||
1dacc76d JB |
1873 | #ifdef CONFIG_COMPAT_NETLINK_MESSAGES |
1874 | if (unlikely(skb_shinfo(skb)->frag_list)) { | |
1dacc76d | 1875 | /* |
68d6ac6d JB |
1876 | * If this skb has a frag_list, then here that means that we |
1877 | * will have to use the frag_list skb's data for compat tasks | |
1878 | * and the regular skb's data for normal (non-compat) tasks. | |
1dacc76d | 1879 | * |
68d6ac6d JB |
1880 | * If we need to send the compat skb, assign it to the |
1881 | * 'data_skb' variable so that it will be used below for data | |
1882 | * copying. We keep 'skb' for everything else, including | |
1883 | * freeing both later. | |
1dacc76d | 1884 | */ |
68d6ac6d JB |
1885 | if (flags & MSG_CMSG_COMPAT) |
1886 | data_skb = skb_shinfo(skb)->frag_list; | |
1dacc76d JB |
1887 | } |
1888 | #endif | |
1889 | ||
9063e21f ED |
1890 | /* Record the max length of recvmsg() calls for future allocations */ |
1891 | nlk->max_recvmsg_len = max(nlk->max_recvmsg_len, len); | |
1892 | nlk->max_recvmsg_len = min_t(size_t, nlk->max_recvmsg_len, | |
d35c99ff | 1893 | SKB_WITH_OVERHEAD(32768)); |
9063e21f | 1894 | |
68d6ac6d | 1895 | copied = data_skb->len; |
1da177e4 LT |
1896 | if (len < copied) { |
1897 | msg->msg_flags |= MSG_TRUNC; | |
1898 | copied = len; | |
1899 | } | |
1900 | ||
68d6ac6d | 1901 | skb_reset_transport_header(data_skb); |
51f3d02b | 1902 | err = skb_copy_datagram_msg(data_skb, 0, msg, copied); |
1da177e4 LT |
1903 | |
1904 | if (msg->msg_name) { | |
342dfc30 | 1905 | DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name); |
1da177e4 LT |
1906 | addr->nl_family = AF_NETLINK; |
1907 | addr->nl_pad = 0; | |
15e47304 | 1908 | addr->nl_pid = NETLINK_CB(skb).portid; |
d629b836 | 1909 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
1910 | msg->msg_namelen = sizeof(*addr); |
1911 | } | |
1912 | ||
cc3a572f | 1913 | if (nlk->flags & NETLINK_F_RECV_PKTINFO) |
cc9a06cd | 1914 | netlink_cmsg_recv_pktinfo(msg, skb); |
59324cf3 ND |
1915 | if (nlk->flags & NETLINK_F_LISTEN_ALL_NSID) |
1916 | netlink_cmsg_listen_all_nsid(sk, msg, skb); | |
cc9a06cd | 1917 | |
7cc05662 CH |
1918 | memset(&scm, 0, sizeof(scm)); |
1919 | scm.creds = *NETLINK_CREDS(skb); | |
188ccb55 | 1920 | if (flags & MSG_TRUNC) |
68d6ac6d | 1921 | copied = data_skb->len; |
daa3766e | 1922 | |
1da177e4 LT |
1923 | skb_free_datagram(sk, skb); |
1924 | ||
16b304f3 PS |
1925 | if (nlk->cb_running && |
1926 | atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) { | |
b44d211e AV |
1927 | ret = netlink_dump(sk); |
1928 | if (ret) { | |
ac30ef83 | 1929 | sk->sk_err = -ret; |
b44d211e AV |
1930 | sk->sk_error_report(sk); |
1931 | } | |
1932 | } | |
1da177e4 | 1933 | |
7cc05662 | 1934 | scm_recv(sock, msg, &scm, flags); |
1da177e4 LT |
1935 | out: |
1936 | netlink_rcv_wake(sk); | |
1937 | return err ? : copied; | |
1938 | } | |
1939 | ||
676d2369 | 1940 | static void netlink_data_ready(struct sock *sk) |
1da177e4 | 1941 | { |
cd40b7d3 | 1942 | BUG(); |
1da177e4 LT |
1943 | } |
1944 | ||
1945 | /* | |
746fac4d | 1946 | * We export these functions to other modules. They provide a |
1da177e4 LT |
1947 | * complete set of kernel non-blocking support for message |
1948 | * queueing. | |
1949 | */ | |
1950 | ||
1951 | struct sock * | |
9f00d977 PNA |
1952 | __netlink_kernel_create(struct net *net, int unit, struct module *module, |
1953 | struct netlink_kernel_cfg *cfg) | |
1da177e4 LT |
1954 | { |
1955 | struct socket *sock; | |
1956 | struct sock *sk; | |
77247bbb | 1957 | struct netlink_sock *nlk; |
5c398dc8 | 1958 | struct listeners *listeners = NULL; |
a31f2d17 PNA |
1959 | struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL; |
1960 | unsigned int groups; | |
1da177e4 | 1961 | |
fab2caf6 | 1962 | BUG_ON(!nl_table); |
1da177e4 | 1963 | |
6ac552fd | 1964 | if (unit < 0 || unit >= MAX_LINKS) |
1da177e4 LT |
1965 | return NULL; |
1966 | ||
1967 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
1968 | return NULL; | |
13d3078e EB |
1969 | |
1970 | if (__netlink_create(net, sock, cb_mutex, unit, 1) < 0) | |
23fe1866 PE |
1971 | goto out_sock_release_nosk; |
1972 | ||
1973 | sk = sock->sk; | |
4fdb3bb7 | 1974 | |
a31f2d17 | 1975 | if (!cfg || cfg->groups < 32) |
4277a083 | 1976 | groups = 32; |
a31f2d17 PNA |
1977 | else |
1978 | groups = cfg->groups; | |
4277a083 | 1979 | |
5c398dc8 | 1980 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
4277a083 PM |
1981 | if (!listeners) |
1982 | goto out_sock_release; | |
1983 | ||
1da177e4 | 1984 | sk->sk_data_ready = netlink_data_ready; |
a31f2d17 PNA |
1985 | if (cfg && cfg->input) |
1986 | nlk_sk(sk)->netlink_rcv = cfg->input; | |
1da177e4 | 1987 | |
8ea65f4a | 1988 | if (netlink_insert(sk, 0)) |
77247bbb | 1989 | goto out_sock_release; |
4fdb3bb7 | 1990 | |
77247bbb | 1991 | nlk = nlk_sk(sk); |
cc3a572f | 1992 | nlk->flags |= NETLINK_F_KERNEL_SOCKET; |
4fdb3bb7 | 1993 | |
4fdb3bb7 | 1994 | netlink_table_grab(); |
b4b51029 EB |
1995 | if (!nl_table[unit].registered) { |
1996 | nl_table[unit].groups = groups; | |
5c398dc8 | 1997 | rcu_assign_pointer(nl_table[unit].listeners, listeners); |
b4b51029 EB |
1998 | nl_table[unit].cb_mutex = cb_mutex; |
1999 | nl_table[unit].module = module; | |
9785e10a PNA |
2000 | if (cfg) { |
2001 | nl_table[unit].bind = cfg->bind; | |
6251edd9 | 2002 | nl_table[unit].unbind = cfg->unbind; |
9785e10a | 2003 | nl_table[unit].flags = cfg->flags; |
da12c90e G |
2004 | if (cfg->compare) |
2005 | nl_table[unit].compare = cfg->compare; | |
9785e10a | 2006 | } |
b4b51029 | 2007 | nl_table[unit].registered = 1; |
f937f1f4 JJ |
2008 | } else { |
2009 | kfree(listeners); | |
869e58f8 | 2010 | nl_table[unit].registered++; |
b4b51029 | 2011 | } |
4fdb3bb7 | 2012 | netlink_table_ungrab(); |
77247bbb PM |
2013 | return sk; |
2014 | ||
4fdb3bb7 | 2015 | out_sock_release: |
4277a083 | 2016 | kfree(listeners); |
9dfbec1f | 2017 | netlink_kernel_release(sk); |
23fe1866 PE |
2018 | return NULL; |
2019 | ||
2020 | out_sock_release_nosk: | |
4fdb3bb7 | 2021 | sock_release(sock); |
77247bbb | 2022 | return NULL; |
1da177e4 | 2023 | } |
9f00d977 | 2024 | EXPORT_SYMBOL(__netlink_kernel_create); |
b7c6ba6e DL |
2025 | |
2026 | void | |
2027 | netlink_kernel_release(struct sock *sk) | |
2028 | { | |
13d3078e EB |
2029 | if (sk == NULL || sk->sk_socket == NULL) |
2030 | return; | |
2031 | ||
2032 | sock_release(sk->sk_socket); | |
b7c6ba6e DL |
2033 | } |
2034 | EXPORT_SYMBOL(netlink_kernel_release); | |
2035 | ||
d136f1bd | 2036 | int __netlink_change_ngroups(struct sock *sk, unsigned int groups) |
b4ff4f04 | 2037 | { |
5c398dc8 | 2038 | struct listeners *new, *old; |
b4ff4f04 | 2039 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; |
b4ff4f04 JB |
2040 | |
2041 | if (groups < 32) | |
2042 | groups = 32; | |
2043 | ||
b4ff4f04 | 2044 | if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { |
5c398dc8 ED |
2045 | new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC); |
2046 | if (!new) | |
d136f1bd | 2047 | return -ENOMEM; |
6d772ac5 | 2048 | old = nl_deref_protected(tbl->listeners); |
5c398dc8 ED |
2049 | memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups)); |
2050 | rcu_assign_pointer(tbl->listeners, new); | |
2051 | ||
37b6b935 | 2052 | kfree_rcu(old, rcu); |
b4ff4f04 JB |
2053 | } |
2054 | tbl->groups = groups; | |
2055 | ||
d136f1bd JB |
2056 | return 0; |
2057 | } | |
2058 | ||
2059 | /** | |
2060 | * netlink_change_ngroups - change number of multicast groups | |
2061 | * | |
2062 | * This changes the number of multicast groups that are available | |
2063 | * on a certain netlink family. Note that it is not possible to | |
2064 | * change the number of groups to below 32. Also note that it does | |
2065 | * not implicitly call netlink_clear_multicast_users() when the | |
2066 | * number of groups is reduced. | |
2067 | * | |
2068 | * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). | |
2069 | * @groups: The new number of groups. | |
2070 | */ | |
2071 | int netlink_change_ngroups(struct sock *sk, unsigned int groups) | |
2072 | { | |
2073 | int err; | |
2074 | ||
2075 | netlink_table_grab(); | |
2076 | err = __netlink_change_ngroups(sk, groups); | |
b4ff4f04 | 2077 | netlink_table_ungrab(); |
d136f1bd | 2078 | |
b4ff4f04 JB |
2079 | return err; |
2080 | } | |
b4ff4f04 | 2081 | |
b8273570 JB |
2082 | void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group) |
2083 | { | |
2084 | struct sock *sk; | |
b8273570 JB |
2085 | struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; |
2086 | ||
b67bfe0d | 2087 | sk_for_each_bound(sk, &tbl->mc_list) |
b8273570 JB |
2088 | netlink_update_socket_mc(nlk_sk(sk), group, 0); |
2089 | } | |
2090 | ||
a46621a3 | 2091 | struct nlmsghdr * |
15e47304 | 2092 | __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags) |
a46621a3 DV |
2093 | { |
2094 | struct nlmsghdr *nlh; | |
573ce260 | 2095 | int size = nlmsg_msg_size(len); |
a46621a3 | 2096 | |
23b45672 | 2097 | nlh = (struct nlmsghdr *)skb_put(skb, NLMSG_ALIGN(size)); |
a46621a3 DV |
2098 | nlh->nlmsg_type = type; |
2099 | nlh->nlmsg_len = size; | |
2100 | nlh->nlmsg_flags = flags; | |
15e47304 | 2101 | nlh->nlmsg_pid = portid; |
a46621a3 DV |
2102 | nlh->nlmsg_seq = seq; |
2103 | if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0) | |
573ce260 | 2104 | memset(nlmsg_data(nlh) + len, 0, NLMSG_ALIGN(size) - size); |
a46621a3 DV |
2105 | return nlh; |
2106 | } | |
2107 | EXPORT_SYMBOL(__nlmsg_put); | |
2108 | ||
1da177e4 LT |
2109 | /* |
2110 | * It looks a bit ugly. | |
2111 | * It would be better to create kernel thread. | |
2112 | */ | |
2113 | ||
2114 | static int netlink_dump(struct sock *sk) | |
2115 | { | |
2116 | struct netlink_sock *nlk = nlk_sk(sk); | |
2117 | struct netlink_callback *cb; | |
c7ac8679 | 2118 | struct sk_buff *skb = NULL; |
1da177e4 | 2119 | struct nlmsghdr *nlh; |
92964c79 | 2120 | struct module *module; |
bf8b79e4 | 2121 | int len, err = -ENOBUFS; |
db65a3aa | 2122 | int alloc_min_size; |
c7ac8679 | 2123 | int alloc_size; |
1da177e4 | 2124 | |
af65bdfc | 2125 | mutex_lock(nlk->cb_mutex); |
16b304f3 | 2126 | if (!nlk->cb_running) { |
bf8b79e4 TG |
2127 | err = -EINVAL; |
2128 | goto errout_skb; | |
1da177e4 LT |
2129 | } |
2130 | ||
d1b4c689 | 2131 | if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) |
f9c22888 | 2132 | goto errout_skb; |
9063e21f ED |
2133 | |
2134 | /* NLMSG_GOODSIZE is small to avoid high order allocations being | |
2135 | * required, but it makes sense to _attempt_ a 16K bytes allocation | |
2136 | * to reduce number of system calls on dump operations, if user | |
2137 | * ever provided a big enough buffer. | |
2138 | */ | |
db65a3aa AR |
2139 | cb = &nlk->cb; |
2140 | alloc_min_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE); | |
2141 | ||
2142 | if (alloc_min_size < nlk->max_recvmsg_len) { | |
2143 | alloc_size = nlk->max_recvmsg_len; | |
d35c99ff ED |
2144 | skb = alloc_skb(alloc_size, |
2145 | (GFP_KERNEL & ~__GFP_DIRECT_RECLAIM) | | |
2146 | __GFP_NOWARN | __GFP_NORETRY); | |
9063e21f | 2147 | } |
db65a3aa AR |
2148 | if (!skb) { |
2149 | alloc_size = alloc_min_size; | |
c5b0db32 | 2150 | skb = alloc_skb(alloc_size, GFP_KERNEL); |
db65a3aa | 2151 | } |
c7ac8679 | 2152 | if (!skb) |
c63d6ea3 | 2153 | goto errout_skb; |
db65a3aa AR |
2154 | |
2155 | /* Trim skb to allocated size. User is expected to provide buffer as | |
2156 | * large as max(min_dump_alloc, 16KiB (mac_recvmsg_len capped at | |
2157 | * netlink_recvmsg())). dump will pack as many smaller messages as | |
2158 | * could fit within the allocated skb. skb is typically allocated | |
2159 | * with larger space than required (could be as much as near 2x the | |
2160 | * requested size with align to next power of 2 approach). Allowing | |
2161 | * dump to use the excess space makes it difficult for a user to have a | |
2162 | * reasonable static buffer based on the expected largest dump of a | |
2163 | * single netdev. The outcome is MSG_TRUNC error. | |
2164 | */ | |
d1b4c689 | 2165 | skb_reserve(skb, skb_tailroom(skb) - alloc_size); |
f9c22888 | 2166 | netlink_skb_set_owner_r(skb, sk); |
c7ac8679 | 2167 | |
1da177e4 LT |
2168 | len = cb->dump(skb, cb); |
2169 | ||
2170 | if (len > 0) { | |
af65bdfc | 2171 | mutex_unlock(nlk->cb_mutex); |
b1153f29 SH |
2172 | |
2173 | if (sk_filter(sk, skb)) | |
2174 | kfree_skb(skb); | |
4a7e7c2a ED |
2175 | else |
2176 | __netlink_sendskb(sk, skb); | |
1da177e4 LT |
2177 | return 0; |
2178 | } | |
2179 | ||
bf8b79e4 TG |
2180 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); |
2181 | if (!nlh) | |
2182 | goto errout_skb; | |
2183 | ||
670dc283 JB |
2184 | nl_dump_check_consistent(cb, nlh); |
2185 | ||
bf8b79e4 TG |
2186 | memcpy(nlmsg_data(nlh), &len, sizeof(len)); |
2187 | ||
b1153f29 SH |
2188 | if (sk_filter(sk, skb)) |
2189 | kfree_skb(skb); | |
4a7e7c2a ED |
2190 | else |
2191 | __netlink_sendskb(sk, skb); | |
1da177e4 | 2192 | |
a8f74b22 TG |
2193 | if (cb->done) |
2194 | cb->done(cb); | |
1da177e4 | 2195 | |
16b304f3 | 2196 | nlk->cb_running = false; |
92964c79 HX |
2197 | module = cb->module; |
2198 | skb = cb->skb; | |
16b304f3 | 2199 | mutex_unlock(nlk->cb_mutex); |
92964c79 HX |
2200 | module_put(module); |
2201 | consume_skb(skb); | |
1da177e4 | 2202 | return 0; |
1797754e | 2203 | |
bf8b79e4 | 2204 | errout_skb: |
af65bdfc | 2205 | mutex_unlock(nlk->cb_mutex); |
bf8b79e4 | 2206 | kfree_skb(skb); |
bf8b79e4 | 2207 | return err; |
1da177e4 LT |
2208 | } |
2209 | ||
6dc878a8 G |
2210 | int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, |
2211 | const struct nlmsghdr *nlh, | |
2212 | struct netlink_dump_control *control) | |
1da177e4 LT |
2213 | { |
2214 | struct netlink_callback *cb; | |
2215 | struct sock *sk; | |
2216 | struct netlink_sock *nlk; | |
b44d211e | 2217 | int ret; |
1da177e4 | 2218 | |
d1b4c689 | 2219 | atomic_inc(&skb->users); |
f9c22888 | 2220 | |
15e47304 | 2221 | sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).portid); |
1da177e4 | 2222 | if (sk == NULL) { |
16b304f3 PS |
2223 | ret = -ECONNREFUSED; |
2224 | goto error_free; | |
1da177e4 | 2225 | } |
6dc878a8 | 2226 | |
16b304f3 | 2227 | nlk = nlk_sk(sk); |
af65bdfc | 2228 | mutex_lock(nlk->cb_mutex); |
6dc878a8 | 2229 | /* A dump is in progress... */ |
16b304f3 | 2230 | if (nlk->cb_running) { |
6dc878a8 | 2231 | ret = -EBUSY; |
16b304f3 | 2232 | goto error_unlock; |
1da177e4 | 2233 | } |
6dc878a8 | 2234 | /* add reference of module which cb->dump belongs to */ |
16b304f3 | 2235 | if (!try_module_get(control->module)) { |
6dc878a8 | 2236 | ret = -EPROTONOSUPPORT; |
16b304f3 | 2237 | goto error_unlock; |
6dc878a8 G |
2238 | } |
2239 | ||
16b304f3 PS |
2240 | cb = &nlk->cb; |
2241 | memset(cb, 0, sizeof(*cb)); | |
fc9e50f5 | 2242 | cb->start = control->start; |
16b304f3 PS |
2243 | cb->dump = control->dump; |
2244 | cb->done = control->done; | |
2245 | cb->nlh = nlh; | |
2246 | cb->data = control->data; | |
2247 | cb->module = control->module; | |
2248 | cb->min_dump_alloc = control->min_dump_alloc; | |
2249 | cb->skb = skb; | |
2250 | ||
2251 | nlk->cb_running = true; | |
2252 | ||
af65bdfc | 2253 | mutex_unlock(nlk->cb_mutex); |
1da177e4 | 2254 | |
fc9e50f5 TH |
2255 | if (cb->start) |
2256 | cb->start(cb); | |
2257 | ||
b44d211e | 2258 | ret = netlink_dump(sk); |
1da177e4 | 2259 | sock_put(sk); |
5c58298c | 2260 | |
b44d211e AV |
2261 | if (ret) |
2262 | return ret; | |
2263 | ||
5c58298c DL |
2264 | /* We successfully started a dump, by returning -EINTR we |
2265 | * signal not to send ACK even if it was requested. | |
2266 | */ | |
2267 | return -EINTR; | |
16b304f3 PS |
2268 | |
2269 | error_unlock: | |
2270 | sock_put(sk); | |
2271 | mutex_unlock(nlk->cb_mutex); | |
2272 | error_free: | |
2273 | kfree_skb(skb); | |
2274 | return ret; | |
1da177e4 | 2275 | } |
6dc878a8 | 2276 | EXPORT_SYMBOL(__netlink_dump_start); |
1da177e4 LT |
2277 | |
2278 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) | |
2279 | { | |
2280 | struct sk_buff *skb; | |
2281 | struct nlmsghdr *rep; | |
2282 | struct nlmsgerr *errmsg; | |
339bf98f | 2283 | size_t payload = sizeof(*errmsg); |
0a6a3a23 | 2284 | struct netlink_sock *nlk = nlk_sk(NETLINK_CB(in_skb).sk); |
1da177e4 | 2285 | |
0a6a3a23 CR |
2286 | /* Error messages get the original request appened, unless the user |
2287 | * requests to cap the error message. | |
2288 | */ | |
2289 | if (!(nlk->flags & NETLINK_F_CAP_ACK) && err) | |
339bf98f | 2290 | payload += nlmsg_len(nlh); |
1da177e4 | 2291 | |
c5b0db32 | 2292 | skb = nlmsg_new(payload, GFP_KERNEL); |
1da177e4 LT |
2293 | if (!skb) { |
2294 | struct sock *sk; | |
2295 | ||
3b1e0a65 | 2296 | sk = netlink_lookup(sock_net(in_skb->sk), |
b4b51029 | 2297 | in_skb->sk->sk_protocol, |
15e47304 | 2298 | NETLINK_CB(in_skb).portid); |
1da177e4 LT |
2299 | if (sk) { |
2300 | sk->sk_err = ENOBUFS; | |
2301 | sk->sk_error_report(sk); | |
2302 | sock_put(sk); | |
2303 | } | |
2304 | return; | |
2305 | } | |
2306 | ||
15e47304 | 2307 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, |
5dba93ae | 2308 | NLMSG_ERROR, payload, 0); |
bf8b79e4 | 2309 | errmsg = nlmsg_data(rep); |
1da177e4 | 2310 | errmsg->error = err; |
0a6a3a23 | 2311 | memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh)); |
15e47304 | 2312 | netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT); |
1da177e4 | 2313 | } |
6ac552fd | 2314 | EXPORT_SYMBOL(netlink_ack); |
1da177e4 | 2315 | |
cd40b7d3 | 2316 | int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
1d00a4eb | 2317 | struct nlmsghdr *)) |
82ace47a | 2318 | { |
82ace47a TG |
2319 | struct nlmsghdr *nlh; |
2320 | int err; | |
2321 | ||
2322 | while (skb->len >= nlmsg_total_size(0)) { | |
cd40b7d3 DL |
2323 | int msglen; |
2324 | ||
b529ccf2 | 2325 | nlh = nlmsg_hdr(skb); |
d35b6856 | 2326 | err = 0; |
82ace47a | 2327 | |
ad8e4b75 | 2328 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
2329 | return 0; |
2330 | ||
d35b6856 TG |
2331 | /* Only requests are handled by the kernel */ |
2332 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | |
5c58298c | 2333 | goto ack; |
45e7ae7f TG |
2334 | |
2335 | /* Skip control messages */ | |
2336 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | |
5c58298c | 2337 | goto ack; |
d35b6856 | 2338 | |
1d00a4eb | 2339 | err = cb(skb, nlh); |
5c58298c DL |
2340 | if (err == -EINTR) |
2341 | goto skip; | |
2342 | ||
2343 | ack: | |
d35b6856 | 2344 | if (nlh->nlmsg_flags & NLM_F_ACK || err) |
82ace47a | 2345 | netlink_ack(skb, nlh, err); |
82ace47a | 2346 | |
5c58298c | 2347 | skip: |
6ac552fd | 2348 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
cd40b7d3 DL |
2349 | if (msglen > skb->len) |
2350 | msglen = skb->len; | |
2351 | skb_pull(skb, msglen); | |
82ace47a TG |
2352 | } |
2353 | ||
2354 | return 0; | |
2355 | } | |
6ac552fd | 2356 | EXPORT_SYMBOL(netlink_rcv_skb); |
82ace47a | 2357 | |
d387f6ad TG |
2358 | /** |
2359 | * nlmsg_notify - send a notification netlink message | |
2360 | * @sk: netlink socket to use | |
2361 | * @skb: notification message | |
15e47304 | 2362 | * @portid: destination netlink portid for reports or 0 |
d387f6ad TG |
2363 | * @group: destination multicast group or 0 |
2364 | * @report: 1 to report back, 0 to disable | |
2365 | * @flags: allocation flags | |
2366 | */ | |
15e47304 | 2367 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, |
d387f6ad TG |
2368 | unsigned int group, int report, gfp_t flags) |
2369 | { | |
2370 | int err = 0; | |
2371 | ||
2372 | if (group) { | |
15e47304 | 2373 | int exclude_portid = 0; |
d387f6ad TG |
2374 | |
2375 | if (report) { | |
2376 | atomic_inc(&skb->users); | |
15e47304 | 2377 | exclude_portid = portid; |
d387f6ad TG |
2378 | } |
2379 | ||
1ce85fe4 PNA |
2380 | /* errors reported via destination sk->sk_err, but propagate |
2381 | * delivery errors if NETLINK_BROADCAST_ERROR flag is set */ | |
15e47304 | 2382 | err = nlmsg_multicast(sk, skb, exclude_portid, group, flags); |
d387f6ad TG |
2383 | } |
2384 | ||
1ce85fe4 PNA |
2385 | if (report) { |
2386 | int err2; | |
2387 | ||
15e47304 | 2388 | err2 = nlmsg_unicast(sk, skb, portid); |
1ce85fe4 PNA |
2389 | if (!err || err == -ESRCH) |
2390 | err = err2; | |
2391 | } | |
d387f6ad TG |
2392 | |
2393 | return err; | |
2394 | } | |
6ac552fd | 2395 | EXPORT_SYMBOL(nlmsg_notify); |
d387f6ad | 2396 | |
1da177e4 LT |
2397 | #ifdef CONFIG_PROC_FS |
2398 | struct nl_seq_iter { | |
e372c414 | 2399 | struct seq_net_private p; |
56d28b1e | 2400 | struct rhashtable_iter hti; |
1da177e4 | 2401 | int link; |
1da177e4 LT |
2402 | }; |
2403 | ||
56d28b1e | 2404 | static int netlink_walk_start(struct nl_seq_iter *iter) |
1da177e4 | 2405 | { |
56d28b1e | 2406 | int err; |
1da177e4 | 2407 | |
8f6fd83c BC |
2408 | err = rhashtable_walk_init(&nl_table[iter->link].hash, &iter->hti, |
2409 | GFP_KERNEL); | |
56d28b1e HX |
2410 | if (err) { |
2411 | iter->link = MAX_LINKS; | |
2412 | return err; | |
1da177e4 | 2413 | } |
56d28b1e HX |
2414 | |
2415 | err = rhashtable_walk_start(&iter->hti); | |
2416 | return err == -EAGAIN ? 0 : err; | |
1da177e4 LT |
2417 | } |
2418 | ||
56d28b1e | 2419 | static void netlink_walk_stop(struct nl_seq_iter *iter) |
1da177e4 | 2420 | { |
56d28b1e HX |
2421 | rhashtable_walk_stop(&iter->hti); |
2422 | rhashtable_walk_exit(&iter->hti); | |
1da177e4 LT |
2423 | } |
2424 | ||
56d28b1e | 2425 | static void *__netlink_seq_next(struct seq_file *seq) |
1da177e4 | 2426 | { |
56d28b1e | 2427 | struct nl_seq_iter *iter = seq->private; |
e341694e | 2428 | struct netlink_sock *nlk; |
1da177e4 | 2429 | |
56d28b1e HX |
2430 | do { |
2431 | for (;;) { | |
2432 | int err; | |
1da177e4 | 2433 | |
56d28b1e | 2434 | nlk = rhashtable_walk_next(&iter->hti); |
746fac4d | 2435 | |
56d28b1e HX |
2436 | if (IS_ERR(nlk)) { |
2437 | if (PTR_ERR(nlk) == -EAGAIN) | |
2438 | continue; | |
e341694e | 2439 | |
56d28b1e HX |
2440 | return nlk; |
2441 | } | |
1da177e4 | 2442 | |
56d28b1e HX |
2443 | if (nlk) |
2444 | break; | |
1da177e4 | 2445 | |
56d28b1e HX |
2446 | netlink_walk_stop(iter); |
2447 | if (++iter->link >= MAX_LINKS) | |
2448 | return NULL; | |
da12c90e | 2449 | |
56d28b1e HX |
2450 | err = netlink_walk_start(iter); |
2451 | if (err) | |
2452 | return ERR_PTR(err); | |
1da177e4 | 2453 | } |
56d28b1e | 2454 | } while (sock_net(&nlk->sk) != seq_file_net(seq)); |
1da177e4 | 2455 | |
56d28b1e HX |
2456 | return nlk; |
2457 | } | |
1da177e4 | 2458 | |
56d28b1e HX |
2459 | static void *netlink_seq_start(struct seq_file *seq, loff_t *posp) |
2460 | { | |
2461 | struct nl_seq_iter *iter = seq->private; | |
2462 | void *obj = SEQ_START_TOKEN; | |
2463 | loff_t pos; | |
2464 | int err; | |
2465 | ||
2466 | iter->link = 0; | |
2467 | ||
2468 | err = netlink_walk_start(iter); | |
2469 | if (err) | |
2470 | return ERR_PTR(err); | |
2471 | ||
2472 | for (pos = *posp; pos && obj && !IS_ERR(obj); pos--) | |
2473 | obj = __netlink_seq_next(seq); | |
2474 | ||
2475 | return obj; | |
2476 | } | |
2477 | ||
2478 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2479 | { | |
2480 | ++*pos; | |
2481 | return __netlink_seq_next(seq); | |
1da177e4 LT |
2482 | } |
2483 | ||
2484 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
2485 | { | |
56d28b1e HX |
2486 | struct nl_seq_iter *iter = seq->private; |
2487 | ||
2488 | if (iter->link >= MAX_LINKS) | |
2489 | return; | |
2490 | ||
2491 | netlink_walk_stop(iter); | |
1da177e4 LT |
2492 | } |
2493 | ||
2494 | ||
2495 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
2496 | { | |
658cb354 | 2497 | if (v == SEQ_START_TOKEN) { |
1da177e4 LT |
2498 | seq_puts(seq, |
2499 | "sk Eth Pid Groups " | |
cf0aa4e0 | 2500 | "Rmem Wmem Dump Locks Drops Inode\n"); |
658cb354 | 2501 | } else { |
1da177e4 LT |
2502 | struct sock *s = v; |
2503 | struct netlink_sock *nlk = nlk_sk(s); | |
2504 | ||
16b304f3 | 2505 | seq_printf(seq, "%pK %-3d %-6u %08x %-8d %-8d %d %-8d %-8d %-8lu\n", |
1da177e4 LT |
2506 | s, |
2507 | s->sk_protocol, | |
15e47304 | 2508 | nlk->portid, |
513c2500 | 2509 | nlk->groups ? (u32)nlk->groups[0] : 0, |
31e6d363 ED |
2510 | sk_rmem_alloc_get(s), |
2511 | sk_wmem_alloc_get(s), | |
16b304f3 | 2512 | nlk->cb_running, |
38938bfe | 2513 | atomic_read(&s->sk_refcnt), |
cf0aa4e0 MY |
2514 | atomic_read(&s->sk_drops), |
2515 | sock_i_ino(s) | |
1da177e4 LT |
2516 | ); |
2517 | ||
2518 | } | |
2519 | return 0; | |
2520 | } | |
2521 | ||
56b3d975 | 2522 | static const struct seq_operations netlink_seq_ops = { |
1da177e4 LT |
2523 | .start = netlink_seq_start, |
2524 | .next = netlink_seq_next, | |
2525 | .stop = netlink_seq_stop, | |
2526 | .show = netlink_seq_show, | |
2527 | }; | |
2528 | ||
2529 | ||
2530 | static int netlink_seq_open(struct inode *inode, struct file *file) | |
2531 | { | |
e372c414 DL |
2532 | return seq_open_net(inode, file, &netlink_seq_ops, |
2533 | sizeof(struct nl_seq_iter)); | |
b4b51029 EB |
2534 | } |
2535 | ||
da7071d7 | 2536 | static const struct file_operations netlink_seq_fops = { |
1da177e4 LT |
2537 | .owner = THIS_MODULE, |
2538 | .open = netlink_seq_open, | |
2539 | .read = seq_read, | |
2540 | .llseek = seq_lseek, | |
e372c414 | 2541 | .release = seq_release_net, |
1da177e4 LT |
2542 | }; |
2543 | ||
2544 | #endif | |
2545 | ||
2546 | int netlink_register_notifier(struct notifier_block *nb) | |
2547 | { | |
efa172f4 | 2548 | return blocking_notifier_chain_register(&netlink_chain, nb); |
1da177e4 | 2549 | } |
6ac552fd | 2550 | EXPORT_SYMBOL(netlink_register_notifier); |
1da177e4 LT |
2551 | |
2552 | int netlink_unregister_notifier(struct notifier_block *nb) | |
2553 | { | |
efa172f4 | 2554 | return blocking_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 | 2555 | } |
6ac552fd | 2556 | EXPORT_SYMBOL(netlink_unregister_notifier); |
746fac4d | 2557 | |
90ddc4f0 | 2558 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
2559 | .family = PF_NETLINK, |
2560 | .owner = THIS_MODULE, | |
2561 | .release = netlink_release, | |
2562 | .bind = netlink_bind, | |
2563 | .connect = netlink_connect, | |
2564 | .socketpair = sock_no_socketpair, | |
2565 | .accept = sock_no_accept, | |
2566 | .getname = netlink_getname, | |
d1b4c689 | 2567 | .poll = datagram_poll, |
025c6818 | 2568 | .ioctl = netlink_ioctl, |
1da177e4 LT |
2569 | .listen = sock_no_listen, |
2570 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
2571 | .setsockopt = netlink_setsockopt, |
2572 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
2573 | .sendmsg = netlink_sendmsg, |
2574 | .recvmsg = netlink_recvmsg, | |
d1b4c689 | 2575 | .mmap = sock_no_mmap, |
1da177e4 LT |
2576 | .sendpage = sock_no_sendpage, |
2577 | }; | |
2578 | ||
ec1b4cf7 | 2579 | static const struct net_proto_family netlink_family_ops = { |
1da177e4 LT |
2580 | .family = PF_NETLINK, |
2581 | .create = netlink_create, | |
2582 | .owner = THIS_MODULE, /* for consistency 8) */ | |
2583 | }; | |
2584 | ||
4665079c | 2585 | static int __net_init netlink_net_init(struct net *net) |
b4b51029 EB |
2586 | { |
2587 | #ifdef CONFIG_PROC_FS | |
d4beaa66 | 2588 | if (!proc_create("netlink", 0, net->proc_net, &netlink_seq_fops)) |
b4b51029 EB |
2589 | return -ENOMEM; |
2590 | #endif | |
2591 | return 0; | |
2592 | } | |
2593 | ||
4665079c | 2594 | static void __net_exit netlink_net_exit(struct net *net) |
b4b51029 EB |
2595 | { |
2596 | #ifdef CONFIG_PROC_FS | |
ece31ffd | 2597 | remove_proc_entry("netlink", net->proc_net); |
b4b51029 EB |
2598 | #endif |
2599 | } | |
2600 | ||
b963ea89 DM |
2601 | static void __init netlink_add_usersock_entry(void) |
2602 | { | |
5c398dc8 | 2603 | struct listeners *listeners; |
b963ea89 DM |
2604 | int groups = 32; |
2605 | ||
5c398dc8 | 2606 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
b963ea89 | 2607 | if (!listeners) |
5c398dc8 | 2608 | panic("netlink_add_usersock_entry: Cannot allocate listeners\n"); |
b963ea89 DM |
2609 | |
2610 | netlink_table_grab(); | |
2611 | ||
2612 | nl_table[NETLINK_USERSOCK].groups = groups; | |
5c398dc8 | 2613 | rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners); |
b963ea89 DM |
2614 | nl_table[NETLINK_USERSOCK].module = THIS_MODULE; |
2615 | nl_table[NETLINK_USERSOCK].registered = 1; | |
9785e10a | 2616 | nl_table[NETLINK_USERSOCK].flags = NL_CFG_F_NONROOT_SEND; |
b963ea89 DM |
2617 | |
2618 | netlink_table_ungrab(); | |
2619 | } | |
2620 | ||
022cbae6 | 2621 | static struct pernet_operations __net_initdata netlink_net_ops = { |
b4b51029 EB |
2622 | .init = netlink_net_init, |
2623 | .exit = netlink_net_exit, | |
2624 | }; | |
2625 | ||
49f7b33e | 2626 | static inline u32 netlink_hash(const void *data, u32 len, u32 seed) |
c428ecd1 HX |
2627 | { |
2628 | const struct netlink_sock *nlk = data; | |
2629 | struct netlink_compare_arg arg; | |
2630 | ||
da314c99 | 2631 | netlink_compare_arg_init(&arg, sock_net(&nlk->sk), nlk->portid); |
11b58ba1 | 2632 | return jhash2((u32 *)&arg, netlink_compare_arg_len / sizeof(u32), seed); |
c428ecd1 HX |
2633 | } |
2634 | ||
2635 | static const struct rhashtable_params netlink_rhashtable_params = { | |
2636 | .head_offset = offsetof(struct netlink_sock, node), | |
2637 | .key_len = netlink_compare_arg_len, | |
c428ecd1 HX |
2638 | .obj_hashfn = netlink_hash, |
2639 | .obj_cmpfn = netlink_compare, | |
b5e2c150 | 2640 | .automatic_shrinking = true, |
c428ecd1 HX |
2641 | }; |
2642 | ||
1da177e4 LT |
2643 | static int __init netlink_proto_init(void) |
2644 | { | |
1da177e4 | 2645 | int i; |
1da177e4 LT |
2646 | int err = proto_register(&netlink_proto, 0); |
2647 | ||
2648 | if (err != 0) | |
2649 | goto out; | |
2650 | ||
fab25745 | 2651 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb)); |
1da177e4 | 2652 | |
0da974f4 | 2653 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
2654 | if (!nl_table) |
2655 | goto panic; | |
1da177e4 | 2656 | |
1da177e4 | 2657 | for (i = 0; i < MAX_LINKS; i++) { |
c428ecd1 HX |
2658 | if (rhashtable_init(&nl_table[i].hash, |
2659 | &netlink_rhashtable_params) < 0) { | |
e341694e TG |
2660 | while (--i > 0) |
2661 | rhashtable_destroy(&nl_table[i].hash); | |
1da177e4 | 2662 | kfree(nl_table); |
fab2caf6 | 2663 | goto panic; |
1da177e4 | 2664 | } |
1da177e4 LT |
2665 | } |
2666 | ||
bcbde0d4 DB |
2667 | INIT_LIST_HEAD(&netlink_tap_all); |
2668 | ||
b963ea89 DM |
2669 | netlink_add_usersock_entry(); |
2670 | ||
1da177e4 | 2671 | sock_register(&netlink_family_ops); |
b4b51029 | 2672 | register_pernet_subsys(&netlink_net_ops); |
746fac4d | 2673 | /* The netlink device handler may be needed early. */ |
1da177e4 LT |
2674 | rtnetlink_init(); |
2675 | out: | |
2676 | return err; | |
fab2caf6 AM |
2677 | panic: |
2678 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
2679 | } |
2680 | ||
1da177e4 | 2681 | core_initcall(netlink_proto_init); |