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Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* |
3 | * NETLINK Kernel-user communication protocol. | |
4 | * | |
113aa838 | 5 | * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk> |
1da177e4 | 6 | * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> |
cd1df525 | 7 | * Patrick McHardy <kaber@trash.net> |
1da177e4 | 8 | * |
1da177e4 LT |
9 | * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith |
10 | * added netlink_proto_exit | |
11 | * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br> | |
12 | * use nlk_sk, as sk->protinfo is on a diet 8) | |
4fdb3bb7 HW |
13 | * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org> |
14 | * - inc module use count of module that owns | |
15 | * the kernel socket in case userspace opens | |
16 | * socket of same protocol | |
17 | * - remove all module support, since netlink is | |
18 | * mandatory if CONFIG_NET=y these days | |
1da177e4 LT |
19 | */ |
20 | ||
1da177e4 LT |
21 | #include <linux/module.h> |
22 | ||
b6459415 | 23 | #include <linux/bpf.h> |
4fc268d2 | 24 | #include <linux/capability.h> |
1da177e4 | 25 | #include <linux/kernel.h> |
b6459415 | 26 | #include <linux/filter.h> |
1da177e4 | 27 | #include <linux/init.h> |
1da177e4 LT |
28 | #include <linux/signal.h> |
29 | #include <linux/sched.h> | |
30 | #include <linux/errno.h> | |
31 | #include <linux/string.h> | |
32 | #include <linux/stat.h> | |
33 | #include <linux/socket.h> | |
34 | #include <linux/un.h> | |
35 | #include <linux/fcntl.h> | |
36 | #include <linux/termios.h> | |
37 | #include <linux/sockios.h> | |
38 | #include <linux/net.h> | |
39 | #include <linux/fs.h> | |
40 | #include <linux/slab.h> | |
7c0f6ba6 | 41 | #include <linux/uaccess.h> |
1da177e4 LT |
42 | #include <linux/skbuff.h> |
43 | #include <linux/netdevice.h> | |
44 | #include <linux/rtnetlink.h> | |
45 | #include <linux/proc_fs.h> | |
46 | #include <linux/seq_file.h> | |
1da177e4 LT |
47 | #include <linux/notifier.h> |
48 | #include <linux/security.h> | |
49 | #include <linux/jhash.h> | |
50 | #include <linux/jiffies.h> | |
51 | #include <linux/random.h> | |
52 | #include <linux/bitops.h> | |
53 | #include <linux/mm.h> | |
54 | #include <linux/types.h> | |
54e0f520 | 55 | #include <linux/audit.h> |
af65bdfc | 56 | #include <linux/mutex.h> |
ccdfcc39 | 57 | #include <linux/vmalloc.h> |
bcbde0d4 | 58 | #include <linux/if_arp.h> |
e341694e | 59 | #include <linux/rhashtable.h> |
9652e931 | 60 | #include <asm/cacheflush.h> |
e341694e | 61 | #include <linux/hash.h> |
ee1c2442 | 62 | #include <linux/genetlink.h> |
7212462f | 63 | #include <linux/net_namespace.h> |
bc5b6c0b | 64 | #include <linux/nospec.h> |
951cf368 | 65 | #include <linux/btf_ids.h> |
54e0f520 | 66 | |
457c4cbc | 67 | #include <net/net_namespace.h> |
25e3f70f | 68 | #include <net/netns/generic.h> |
1da177e4 LT |
69 | #include <net/sock.h> |
70 | #include <net/scm.h> | |
82ace47a | 71 | #include <net/netlink.h> |
7e3ce05e MRL |
72 | #define CREATE_TRACE_POINTS |
73 | #include <trace/events/netlink.h> | |
1da177e4 | 74 | |
0f29c768 | 75 | #include "af_netlink.h" |
1da177e4 | 76 | |
5c398dc8 ED |
77 | struct listeners { |
78 | struct rcu_head rcu; | |
2b738124 | 79 | unsigned long masks[]; |
6c04bb18 JB |
80 | }; |
81 | ||
cd967e05 | 82 | /* state bits */ |
cc3a572f | 83 | #define NETLINK_S_CONGESTED 0x0 |
cd967e05 | 84 | |
035c4c16 | 85 | static inline int netlink_is_kernel(struct sock *sk) |
aed81560 | 86 | { |
8fe08d70 | 87 | return nlk_test_bit(KERNEL_SOCKET, sk); |
aed81560 DL |
88 | } |
89 | ||
91dd93f9 | 90 | struct netlink_table *nl_table __read_mostly; |
0f29c768 | 91 | EXPORT_SYMBOL_GPL(nl_table); |
1da177e4 LT |
92 | |
93 | static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); | |
94 | ||
8a0f5ccf HX |
95 | static struct lock_class_key nlk_cb_mutex_keys[MAX_LINKS]; |
96 | ||
97 | static const char *const nlk_cb_mutex_key_strings[MAX_LINKS + 1] = { | |
98 | "nlk_cb_mutex-ROUTE", | |
99 | "nlk_cb_mutex-1", | |
100 | "nlk_cb_mutex-USERSOCK", | |
101 | "nlk_cb_mutex-FIREWALL", | |
102 | "nlk_cb_mutex-SOCK_DIAG", | |
103 | "nlk_cb_mutex-NFLOG", | |
104 | "nlk_cb_mutex-XFRM", | |
105 | "nlk_cb_mutex-SELINUX", | |
106 | "nlk_cb_mutex-ISCSI", | |
107 | "nlk_cb_mutex-AUDIT", | |
108 | "nlk_cb_mutex-FIB_LOOKUP", | |
109 | "nlk_cb_mutex-CONNECTOR", | |
110 | "nlk_cb_mutex-NETFILTER", | |
111 | "nlk_cb_mutex-IP6_FW", | |
112 | "nlk_cb_mutex-DNRTMSG", | |
113 | "nlk_cb_mutex-KOBJECT_UEVENT", | |
114 | "nlk_cb_mutex-GENERIC", | |
115 | "nlk_cb_mutex-17", | |
116 | "nlk_cb_mutex-SCSITRANSPORT", | |
117 | "nlk_cb_mutex-ECRYPTFS", | |
118 | "nlk_cb_mutex-RDMA", | |
119 | "nlk_cb_mutex-CRYPTO", | |
120 | "nlk_cb_mutex-SMC", | |
121 | "nlk_cb_mutex-23", | |
122 | "nlk_cb_mutex-24", | |
123 | "nlk_cb_mutex-25", | |
124 | "nlk_cb_mutex-26", | |
125 | "nlk_cb_mutex-27", | |
126 | "nlk_cb_mutex-28", | |
127 | "nlk_cb_mutex-29", | |
128 | "nlk_cb_mutex-30", | |
129 | "nlk_cb_mutex-31", | |
130 | "nlk_cb_mutex-MAX_LINKS" | |
131 | }; | |
132 | ||
1da177e4 | 133 | static int netlink_dump(struct sock *sk); |
1da177e4 | 134 | |
78fd1d0a | 135 | /* nl_table locking explained: |
21e4902a | 136 | * Lookup and traversal are protected with an RCU read-side lock. Insertion |
c5adde94 | 137 | * and removal are protected with per bucket lock while using RCU list |
21e4902a TG |
138 | * modification primitives and may run in parallel to RCU protected lookups. |
139 | * Destruction of the Netlink socket may only occur *after* nl_table_lock has | |
140 | * been acquired * either during or after the socket has been removed from | |
141 | * the list and after an RCU grace period. | |
78fd1d0a | 142 | */ |
0f29c768 AV |
143 | DEFINE_RWLOCK(nl_table_lock); |
144 | EXPORT_SYMBOL_GPL(nl_table_lock); | |
1da177e4 LT |
145 | static atomic_t nl_table_users = ATOMIC_INIT(0); |
146 | ||
6d772ac5 ED |
147 | #define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock)); |
148 | ||
efa172f4 | 149 | static BLOCKING_NOTIFIER_HEAD(netlink_chain); |
1da177e4 | 150 | |
bcbde0d4 | 151 | |
c428ecd1 HX |
152 | static const struct rhashtable_params netlink_rhashtable_params; |
153 | ||
7e3ce05e MRL |
154 | void do_trace_netlink_extack(const char *msg) |
155 | { | |
156 | trace_netlink_extack(msg); | |
157 | } | |
158 | EXPORT_SYMBOL(do_trace_netlink_extack); | |
159 | ||
b57ef81f | 160 | static inline u32 netlink_group_mask(u32 group) |
d629b836 | 161 | { |
0caf6d99 PM |
162 | if (group > 32) |
163 | return 0; | |
d629b836 PM |
164 | return group ? 1 << (group - 1) : 0; |
165 | } | |
166 | ||
1853c949 DB |
167 | static struct sk_buff *netlink_to_full_skb(const struct sk_buff *skb, |
168 | gfp_t gfp_mask) | |
169 | { | |
170 | unsigned int len = skb_end_offset(skb); | |
171 | struct sk_buff *new; | |
172 | ||
173 | new = alloc_skb(len, gfp_mask); | |
174 | if (new == NULL) | |
175 | return NULL; | |
176 | ||
177 | NETLINK_CB(new).portid = NETLINK_CB(skb).portid; | |
178 | NETLINK_CB(new).dst_group = NETLINK_CB(skb).dst_group; | |
179 | NETLINK_CB(new).creds = NETLINK_CB(skb).creds; | |
180 | ||
59ae1d12 | 181 | skb_put_data(new, skb->data, len); |
1853c949 DB |
182 | return new; |
183 | } | |
184 | ||
25e3f70f CW |
185 | static unsigned int netlink_tap_net_id; |
186 | ||
187 | struct netlink_tap_net { | |
188 | struct list_head netlink_tap_all; | |
b1042d35 | 189 | struct mutex netlink_tap_lock; |
25e3f70f CW |
190 | }; |
191 | ||
bcbde0d4 DB |
192 | int netlink_add_tap(struct netlink_tap *nt) |
193 | { | |
25e3f70f CW |
194 | struct net *net = dev_net(nt->dev); |
195 | struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); | |
196 | ||
bcbde0d4 DB |
197 | if (unlikely(nt->dev->type != ARPHRD_NETLINK)) |
198 | return -EINVAL; | |
199 | ||
b1042d35 | 200 | mutex_lock(&nn->netlink_tap_lock); |
25e3f70f | 201 | list_add_rcu(&nt->list, &nn->netlink_tap_all); |
b1042d35 | 202 | mutex_unlock(&nn->netlink_tap_lock); |
bcbde0d4 | 203 | |
fcd4d35e | 204 | __module_get(nt->module); |
bcbde0d4 DB |
205 | |
206 | return 0; | |
207 | } | |
208 | EXPORT_SYMBOL_GPL(netlink_add_tap); | |
209 | ||
2173f8d9 | 210 | static int __netlink_remove_tap(struct netlink_tap *nt) |
bcbde0d4 | 211 | { |
25e3f70f CW |
212 | struct net *net = dev_net(nt->dev); |
213 | struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); | |
bcbde0d4 DB |
214 | bool found = false; |
215 | struct netlink_tap *tmp; | |
216 | ||
b1042d35 | 217 | mutex_lock(&nn->netlink_tap_lock); |
bcbde0d4 | 218 | |
25e3f70f | 219 | list_for_each_entry(tmp, &nn->netlink_tap_all, list) { |
bcbde0d4 DB |
220 | if (nt == tmp) { |
221 | list_del_rcu(&nt->list); | |
222 | found = true; | |
223 | goto out; | |
224 | } | |
225 | } | |
226 | ||
227 | pr_warn("__netlink_remove_tap: %p not found\n", nt); | |
228 | out: | |
b1042d35 | 229 | mutex_unlock(&nn->netlink_tap_lock); |
bcbde0d4 | 230 | |
92b80eb3 | 231 | if (found) |
bcbde0d4 DB |
232 | module_put(nt->module); |
233 | ||
234 | return found ? 0 : -ENODEV; | |
235 | } | |
bcbde0d4 DB |
236 | |
237 | int netlink_remove_tap(struct netlink_tap *nt) | |
238 | { | |
239 | int ret; | |
240 | ||
241 | ret = __netlink_remove_tap(nt); | |
242 | synchronize_net(); | |
243 | ||
244 | return ret; | |
245 | } | |
246 | EXPORT_SYMBOL_GPL(netlink_remove_tap); | |
247 | ||
25e3f70f CW |
248 | static __net_init int netlink_tap_init_net(struct net *net) |
249 | { | |
250 | struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); | |
251 | ||
252 | INIT_LIST_HEAD(&nn->netlink_tap_all); | |
b1042d35 | 253 | mutex_init(&nn->netlink_tap_lock); |
25e3f70f CW |
254 | return 0; |
255 | } | |
256 | ||
25e3f70f CW |
257 | static struct pernet_operations netlink_tap_net_ops = { |
258 | .init = netlink_tap_init_net, | |
25e3f70f CW |
259 | .id = &netlink_tap_net_id, |
260 | .size = sizeof(struct netlink_tap_net), | |
261 | }; | |
262 | ||
5ffd5cdd DB |
263 | static bool netlink_filter_tap(const struct sk_buff *skb) |
264 | { | |
265 | struct sock *sk = skb->sk; | |
5ffd5cdd DB |
266 | |
267 | /* We take the more conservative approach and | |
268 | * whitelist socket protocols that may pass. | |
269 | */ | |
270 | switch (sk->sk_protocol) { | |
271 | case NETLINK_ROUTE: | |
272 | case NETLINK_USERSOCK: | |
273 | case NETLINK_SOCK_DIAG: | |
274 | case NETLINK_NFLOG: | |
275 | case NETLINK_XFRM: | |
276 | case NETLINK_FIB_LOOKUP: | |
277 | case NETLINK_NETFILTER: | |
278 | case NETLINK_GENERIC: | |
498044bb | 279 | return true; |
5ffd5cdd DB |
280 | } |
281 | ||
498044bb | 282 | return false; |
5ffd5cdd DB |
283 | } |
284 | ||
bcbde0d4 DB |
285 | static int __netlink_deliver_tap_skb(struct sk_buff *skb, |
286 | struct net_device *dev) | |
287 | { | |
288 | struct sk_buff *nskb; | |
5ffd5cdd | 289 | struct sock *sk = skb->sk; |
bcbde0d4 DB |
290 | int ret = -ENOMEM; |
291 | ||
93c64764 KC |
292 | if (!net_eq(dev_net(dev), sock_net(sk))) |
293 | return 0; | |
294 | ||
bcbde0d4 | 295 | dev_hold(dev); |
1853c949 | 296 | |
d1b4c689 | 297 | if (is_vmalloc_addr(skb->head)) |
1853c949 DB |
298 | nskb = netlink_to_full_skb(skb, GFP_ATOMIC); |
299 | else | |
300 | nskb = skb_clone(skb, GFP_ATOMIC); | |
bcbde0d4 DB |
301 | if (nskb) { |
302 | nskb->dev = dev; | |
5ffd5cdd | 303 | nskb->protocol = htons((u16) sk->sk_protocol); |
604d13c9 DB |
304 | nskb->pkt_type = netlink_is_kernel(sk) ? |
305 | PACKET_KERNEL : PACKET_USER; | |
4e48ed88 | 306 | skb_reset_network_header(nskb); |
bcbde0d4 DB |
307 | ret = dev_queue_xmit(nskb); |
308 | if (unlikely(ret > 0)) | |
309 | ret = net_xmit_errno(ret); | |
310 | } | |
311 | ||
312 | dev_put(dev); | |
313 | return ret; | |
314 | } | |
315 | ||
25e3f70f | 316 | static void __netlink_deliver_tap(struct sk_buff *skb, struct netlink_tap_net *nn) |
bcbde0d4 DB |
317 | { |
318 | int ret; | |
319 | struct netlink_tap *tmp; | |
320 | ||
5ffd5cdd DB |
321 | if (!netlink_filter_tap(skb)) |
322 | return; | |
323 | ||
25e3f70f | 324 | list_for_each_entry_rcu(tmp, &nn->netlink_tap_all, list) { |
bcbde0d4 DB |
325 | ret = __netlink_deliver_tap_skb(skb, tmp->dev); |
326 | if (unlikely(ret)) | |
327 | break; | |
328 | } | |
329 | } | |
330 | ||
25e3f70f | 331 | static void netlink_deliver_tap(struct net *net, struct sk_buff *skb) |
bcbde0d4 | 332 | { |
25e3f70f CW |
333 | struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); |
334 | ||
bcbde0d4 DB |
335 | rcu_read_lock(); |
336 | ||
25e3f70f CW |
337 | if (unlikely(!list_empty(&nn->netlink_tap_all))) |
338 | __netlink_deliver_tap(skb, nn); | |
bcbde0d4 DB |
339 | |
340 | rcu_read_unlock(); | |
341 | } | |
342 | ||
73bfd370 DB |
343 | static void netlink_deliver_tap_kernel(struct sock *dst, struct sock *src, |
344 | struct sk_buff *skb) | |
345 | { | |
346 | if (!(netlink_is_kernel(dst) && netlink_is_kernel(src))) | |
25e3f70f | 347 | netlink_deliver_tap(sock_net(dst), skb); |
73bfd370 DB |
348 | } |
349 | ||
cd1df525 PM |
350 | static void netlink_overrun(struct sock *sk) |
351 | { | |
8fe08d70 | 352 | if (!nlk_test_bit(RECV_NO_ENOBUFS, sk)) { |
cc3a572f ND |
353 | if (!test_and_set_bit(NETLINK_S_CONGESTED, |
354 | &nlk_sk(sk)->state)) { | |
d0f95894 | 355 | WRITE_ONCE(sk->sk_err, ENOBUFS); |
e3ae2365 | 356 | sk_error_report(sk); |
cd1df525 PM |
357 | } |
358 | } | |
359 | atomic_inc(&sk->sk_drops); | |
360 | } | |
361 | ||
362 | static void netlink_rcv_wake(struct sock *sk) | |
363 | { | |
364 | struct netlink_sock *nlk = nlk_sk(sk); | |
365 | ||
174bce38 | 366 | if (skb_queue_empty_lockless(&sk->sk_receive_queue)) |
cc3a572f ND |
367 | clear_bit(NETLINK_S_CONGESTED, &nlk->state); |
368 | if (!test_bit(NETLINK_S_CONGESTED, &nlk->state)) | |
cd1df525 PM |
369 | wake_up_interruptible(&nlk->wait); |
370 | } | |
371 | ||
cf0a018a PM |
372 | static void netlink_skb_destructor(struct sk_buff *skb) |
373 | { | |
c05cdb1b | 374 | if (is_vmalloc_addr(skb->head)) { |
3a36515f PN |
375 | if (!skb->cloned || |
376 | !atomic_dec_return(&(skb_shinfo(skb)->dataref))) | |
377 | vfree(skb->head); | |
378 | ||
c05cdb1b PNA |
379 | skb->head = NULL; |
380 | } | |
9652e931 PM |
381 | if (skb->sk != NULL) |
382 | sock_rfree(skb); | |
cf0a018a PM |
383 | } |
384 | ||
385 | static void netlink_skb_set_owner_r(struct sk_buff *skb, struct sock *sk) | |
386 | { | |
387 | WARN_ON(skb->sk != NULL); | |
388 | skb->sk = sk; | |
389 | skb->destructor = netlink_skb_destructor; | |
390 | atomic_add(skb->truesize, &sk->sk_rmem_alloc); | |
391 | sk_mem_charge(sk, skb->truesize); | |
392 | } | |
393 | ||
ed5d7788 | 394 | static void netlink_sock_destruct(struct sock *sk) |
1da177e4 | 395 | { |
3f660d66 HX |
396 | struct netlink_sock *nlk = nlk_sk(sk); |
397 | ||
16b304f3 | 398 | if (nlk->cb_running) { |
ed5d7788 HX |
399 | if (nlk->cb.done) |
400 | nlk->cb.done(&nlk->cb); | |
16b304f3 PS |
401 | module_put(nlk->cb.module); |
402 | kfree_skb(nlk->cb.skb); | |
3f660d66 HX |
403 | } |
404 | ||
1da177e4 LT |
405 | skb_queue_purge(&sk->sk_receive_queue); |
406 | ||
407 | if (!sock_flag(sk, SOCK_DEAD)) { | |
6ac552fd | 408 | printk(KERN_ERR "Freeing alive netlink socket %p\n", sk); |
1da177e4 LT |
409 | return; |
410 | } | |
547b792c IJ |
411 | |
412 | WARN_ON(atomic_read(&sk->sk_rmem_alloc)); | |
14afee4b | 413 | WARN_ON(refcount_read(&sk->sk_wmem_alloc)); |
547b792c | 414 | WARN_ON(nlk_sk(sk)->groups); |
1da177e4 LT |
415 | } |
416 | ||
707693c8 HX |
417 | static void netlink_sock_destruct_work(struct work_struct *work) |
418 | { | |
419 | struct netlink_sock *nlk = container_of(work, struct netlink_sock, | |
420 | work); | |
421 | ||
ed5d7788 | 422 | sk_free(&nlk->sk); |
707693c8 HX |
423 | } |
424 | ||
6ac552fd PM |
425 | /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on |
426 | * SMP. Look, when several writers sleep and reader wakes them up, all but one | |
1da177e4 LT |
427 | * immediately hit write lock and grab all the cpus. Exclusive sleep solves |
428 | * this, _but_ remember, it adds useless work on UP machines. | |
429 | */ | |
430 | ||
d136f1bd | 431 | void netlink_table_grab(void) |
9a429c49 | 432 | __acquires(nl_table_lock) |
1da177e4 | 433 | { |
d136f1bd JB |
434 | might_sleep(); |
435 | ||
6abd219c | 436 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
437 | |
438 | if (atomic_read(&nl_table_users)) { | |
439 | DECLARE_WAITQUEUE(wait, current); | |
440 | ||
441 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
6ac552fd | 442 | for (;;) { |
1da177e4 LT |
443 | set_current_state(TASK_UNINTERRUPTIBLE); |
444 | if (atomic_read(&nl_table_users) == 0) | |
445 | break; | |
6abd219c | 446 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 447 | schedule(); |
6abd219c | 448 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
449 | } |
450 | ||
451 | __set_current_state(TASK_RUNNING); | |
452 | remove_wait_queue(&nl_table_wait, &wait); | |
453 | } | |
454 | } | |
455 | ||
d136f1bd | 456 | void netlink_table_ungrab(void) |
9a429c49 | 457 | __releases(nl_table_lock) |
1da177e4 | 458 | { |
6abd219c | 459 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
460 | wake_up(&nl_table_wait); |
461 | } | |
462 | ||
6ac552fd | 463 | static inline void |
1da177e4 LT |
464 | netlink_lock_table(void) |
465 | { | |
1d482e66 JB |
466 | unsigned long flags; |
467 | ||
1da177e4 LT |
468 | /* read_lock() synchronizes us to netlink_table_grab */ |
469 | ||
1d482e66 | 470 | read_lock_irqsave(&nl_table_lock, flags); |
1da177e4 | 471 | atomic_inc(&nl_table_users); |
1d482e66 | 472 | read_unlock_irqrestore(&nl_table_lock, flags); |
1da177e4 LT |
473 | } |
474 | ||
6ac552fd | 475 | static inline void |
1da177e4 LT |
476 | netlink_unlock_table(void) |
477 | { | |
478 | if (atomic_dec_and_test(&nl_table_users)) | |
479 | wake_up(&nl_table_wait); | |
480 | } | |
481 | ||
e341694e | 482 | struct netlink_compare_arg |
1da177e4 | 483 | { |
c428ecd1 | 484 | possible_net_t pnet; |
e341694e TG |
485 | u32 portid; |
486 | }; | |
1da177e4 | 487 | |
8f2ddaac HX |
488 | /* Doing sizeof directly may yield 4 extra bytes on 64-bit. */ |
489 | #define netlink_compare_arg_len \ | |
490 | (offsetof(struct netlink_compare_arg, portid) + sizeof(u32)) | |
c428ecd1 HX |
491 | |
492 | static inline int netlink_compare(struct rhashtable_compare_arg *arg, | |
493 | const void *ptr) | |
1da177e4 | 494 | { |
c428ecd1 HX |
495 | const struct netlink_compare_arg *x = arg->key; |
496 | const struct netlink_sock *nlk = ptr; | |
1da177e4 | 497 | |
da314c99 | 498 | return nlk->portid != x->portid || |
c428ecd1 HX |
499 | !net_eq(sock_net(&nlk->sk), read_pnet(&x->pnet)); |
500 | } | |
501 | ||
502 | static void netlink_compare_arg_init(struct netlink_compare_arg *arg, | |
503 | struct net *net, u32 portid) | |
504 | { | |
505 | memset(arg, 0, sizeof(*arg)); | |
506 | write_pnet(&arg->pnet, net); | |
507 | arg->portid = portid; | |
1da177e4 LT |
508 | } |
509 | ||
e341694e TG |
510 | static struct sock *__netlink_lookup(struct netlink_table *table, u32 portid, |
511 | struct net *net) | |
1da177e4 | 512 | { |
c428ecd1 | 513 | struct netlink_compare_arg arg; |
1da177e4 | 514 | |
c428ecd1 HX |
515 | netlink_compare_arg_init(&arg, net, portid); |
516 | return rhashtable_lookup_fast(&table->hash, &arg, | |
517 | netlink_rhashtable_params); | |
1da177e4 LT |
518 | } |
519 | ||
c428ecd1 | 520 | static int __netlink_insert(struct netlink_table *table, struct sock *sk) |
c5adde94 | 521 | { |
c428ecd1 | 522 | struct netlink_compare_arg arg; |
c5adde94 | 523 | |
da314c99 | 524 | netlink_compare_arg_init(&arg, sock_net(sk), nlk_sk(sk)->portid); |
c428ecd1 HX |
525 | return rhashtable_lookup_insert_key(&table->hash, &arg, |
526 | &nlk_sk(sk)->node, | |
527 | netlink_rhashtable_params); | |
c5adde94 YX |
528 | } |
529 | ||
e341694e | 530 | static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid) |
1da177e4 | 531 | { |
e341694e TG |
532 | struct netlink_table *table = &nl_table[protocol]; |
533 | struct sock *sk; | |
1da177e4 | 534 | |
e341694e TG |
535 | rcu_read_lock(); |
536 | sk = __netlink_lookup(table, portid, net); | |
537 | if (sk) | |
538 | sock_hold(sk); | |
539 | rcu_read_unlock(); | |
1da177e4 | 540 | |
e341694e | 541 | return sk; |
1da177e4 LT |
542 | } |
543 | ||
90ddc4f0 | 544 | static const struct proto_ops netlink_ops; |
1da177e4 | 545 | |
4277a083 PM |
546 | static void |
547 | netlink_update_listeners(struct sock *sk) | |
548 | { | |
549 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
4277a083 PM |
550 | unsigned long mask; |
551 | unsigned int i; | |
6d772ac5 ED |
552 | struct listeners *listeners; |
553 | ||
554 | listeners = nl_deref_protected(tbl->listeners); | |
555 | if (!listeners) | |
556 | return; | |
4277a083 | 557 | |
b4ff4f04 | 558 | for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
4277a083 | 559 | mask = 0; |
b67bfe0d | 560 | sk_for_each_bound(sk, &tbl->mc_list) { |
b4ff4f04 JB |
561 | if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) |
562 | mask |= nlk_sk(sk)->groups[i]; | |
563 | } | |
6d772ac5 | 564 | listeners->masks[i] = mask; |
4277a083 PM |
565 | } |
566 | /* this function is only called with the netlink table "grabbed", which | |
567 | * makes sure updates are visible before bind or setsockopt return. */ | |
568 | } | |
569 | ||
8ea65f4a | 570 | static int netlink_insert(struct sock *sk, u32 portid) |
1da177e4 | 571 | { |
da12c90e | 572 | struct netlink_table *table = &nl_table[sk->sk_protocol]; |
919d9db9 | 573 | int err; |
1da177e4 | 574 | |
c5adde94 | 575 | lock_sock(sk); |
1da177e4 | 576 | |
da314c99 HX |
577 | err = nlk_sk(sk)->portid == portid ? 0 : -EBUSY; |
578 | if (nlk_sk(sk)->bound) | |
1da177e4 LT |
579 | goto err; |
580 | ||
c1bb9484 ED |
581 | /* portid can be read locklessly from netlink_getname(). */ |
582 | WRITE_ONCE(nlk_sk(sk)->portid, portid); | |
583 | ||
e341694e | 584 | sock_hold(sk); |
919d9db9 | 585 | |
c428ecd1 HX |
586 | err = __netlink_insert(table, sk); |
587 | if (err) { | |
4e7c1330 DB |
588 | /* In case the hashtable backend returns with -EBUSY |
589 | * from here, it must not escape to the caller. | |
590 | */ | |
591 | if (unlikely(err == -EBUSY)) | |
592 | err = -EOVERFLOW; | |
c428ecd1 HX |
593 | if (err == -EEXIST) |
594 | err = -EADDRINUSE; | |
c5adde94 | 595 | sock_put(sk); |
1f770c0a | 596 | goto err; |
919d9db9 HX |
597 | } |
598 | ||
da314c99 HX |
599 | /* We need to ensure that the socket is hashed and visible. */ |
600 | smp_wmb(); | |
7707a4d0 ED |
601 | /* Paired with lockless reads from netlink_bind(), |
602 | * netlink_connect() and netlink_sendmsg(). | |
603 | */ | |
604 | WRITE_ONCE(nlk_sk(sk)->bound, portid); | |
1f770c0a | 605 | |
1da177e4 | 606 | err: |
c5adde94 | 607 | release_sock(sk); |
1da177e4 LT |
608 | return err; |
609 | } | |
610 | ||
611 | static void netlink_remove(struct sock *sk) | |
612 | { | |
e341694e TG |
613 | struct netlink_table *table; |
614 | ||
e341694e | 615 | table = &nl_table[sk->sk_protocol]; |
c428ecd1 HX |
616 | if (!rhashtable_remove_fast(&table->hash, &nlk_sk(sk)->node, |
617 | netlink_rhashtable_params)) { | |
41c6d650 | 618 | WARN_ON(refcount_read(&sk->sk_refcnt) == 1); |
e341694e TG |
619 | __sock_put(sk); |
620 | } | |
e341694e | 621 | |
1da177e4 | 622 | netlink_table_grab(); |
b10dcb3b | 623 | if (nlk_sk(sk)->subscriptions) { |
1da177e4 | 624 | __sk_del_bind_node(sk); |
b10dcb3b JB |
625 | netlink_update_listeners(sk); |
626 | } | |
ee1c2442 JB |
627 | if (sk->sk_protocol == NETLINK_GENERIC) |
628 | atomic_inc(&genl_sk_destructing_cnt); | |
1da177e4 LT |
629 | netlink_table_ungrab(); |
630 | } | |
631 | ||
632 | static struct proto netlink_proto = { | |
633 | .name = "NETLINK", | |
634 | .owner = THIS_MODULE, | |
635 | .obj_size = sizeof(struct netlink_sock), | |
636 | }; | |
637 | ||
1b8d7ae4 | 638 | static int __netlink_create(struct net *net, struct socket *sock, |
11aa9c28 EB |
639 | struct mutex *cb_mutex, int protocol, |
640 | int kern) | |
1da177e4 LT |
641 | { |
642 | struct sock *sk; | |
643 | struct netlink_sock *nlk; | |
ab33a171 PM |
644 | |
645 | sock->ops = &netlink_ops; | |
646 | ||
11aa9c28 | 647 | sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto, kern); |
ab33a171 PM |
648 | if (!sk) |
649 | return -ENOMEM; | |
650 | ||
651 | sock_init_data(sock, sk); | |
652 | ||
653 | nlk = nlk_sk(sk); | |
658cb354 | 654 | if (cb_mutex) { |
ffa4d721 | 655 | nlk->cb_mutex = cb_mutex; |
658cb354 | 656 | } else { |
ffa4d721 PM |
657 | nlk->cb_mutex = &nlk->cb_def_mutex; |
658 | mutex_init(nlk->cb_mutex); | |
8a0f5ccf HX |
659 | lockdep_set_class_and_name(nlk->cb_mutex, |
660 | nlk_cb_mutex_keys + protocol, | |
661 | nlk_cb_mutex_key_strings[protocol]); | |
ffa4d721 | 662 | } |
ab33a171 PM |
663 | init_waitqueue_head(&nlk->wait); |
664 | ||
665 | sk->sk_destruct = netlink_sock_destruct; | |
666 | sk->sk_protocol = protocol; | |
667 | return 0; | |
668 | } | |
669 | ||
3f378b68 EP |
670 | static int netlink_create(struct net *net, struct socket *sock, int protocol, |
671 | int kern) | |
ab33a171 PM |
672 | { |
673 | struct module *module = NULL; | |
af65bdfc | 674 | struct mutex *cb_mutex; |
f7fa9b10 | 675 | struct netlink_sock *nlk; |
023e2cfa JB |
676 | int (*bind)(struct net *net, int group); |
677 | void (*unbind)(struct net *net, int group); | |
a4c9a56e | 678 | void (*release)(struct sock *sock, unsigned long *groups); |
ab33a171 | 679 | int err = 0; |
1da177e4 LT |
680 | |
681 | sock->state = SS_UNCONNECTED; | |
682 | ||
683 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
684 | return -ESOCKTNOSUPPORT; | |
685 | ||
6ac552fd | 686 | if (protocol < 0 || protocol >= MAX_LINKS) |
1da177e4 | 687 | return -EPROTONOSUPPORT; |
bc5b6c0b | 688 | protocol = array_index_nospec(protocol, MAX_LINKS); |
1da177e4 | 689 | |
77247bbb | 690 | netlink_lock_table(); |
95a5afca | 691 | #ifdef CONFIG_MODULES |
ab33a171 | 692 | if (!nl_table[protocol].registered) { |
77247bbb | 693 | netlink_unlock_table(); |
4fdb3bb7 | 694 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 695 | netlink_lock_table(); |
4fdb3bb7 | 696 | } |
ab33a171 PM |
697 | #endif |
698 | if (nl_table[protocol].registered && | |
699 | try_module_get(nl_table[protocol].module)) | |
700 | module = nl_table[protocol].module; | |
974c37e9 AD |
701 | else |
702 | err = -EPROTONOSUPPORT; | |
af65bdfc | 703 | cb_mutex = nl_table[protocol].cb_mutex; |
03292745 | 704 | bind = nl_table[protocol].bind; |
4f520900 | 705 | unbind = nl_table[protocol].unbind; |
a4c9a56e | 706 | release = nl_table[protocol].release; |
77247bbb | 707 | netlink_unlock_table(); |
4fdb3bb7 | 708 | |
974c37e9 AD |
709 | if (err < 0) |
710 | goto out; | |
711 | ||
11aa9c28 | 712 | err = __netlink_create(net, sock, cb_mutex, protocol, kern); |
6ac552fd | 713 | if (err < 0) |
f7fa9b10 PM |
714 | goto out_module; |
715 | ||
c1fd3b94 | 716 | sock_prot_inuse_add(net, &netlink_proto, 1); |
6f756a8c | 717 | |
f7fa9b10 | 718 | nlk = nlk_sk(sock->sk); |
f7fa9b10 | 719 | nlk->module = module; |
03292745 | 720 | nlk->netlink_bind = bind; |
4f520900 | 721 | nlk->netlink_unbind = unbind; |
a4c9a56e | 722 | nlk->netlink_release = release; |
ab33a171 PM |
723 | out: |
724 | return err; | |
1da177e4 | 725 | |
ab33a171 PM |
726 | out_module: |
727 | module_put(module); | |
728 | goto out; | |
1da177e4 LT |
729 | } |
730 | ||
21e4902a TG |
731 | static void deferred_put_nlk_sk(struct rcu_head *head) |
732 | { | |
733 | struct netlink_sock *nlk = container_of(head, struct netlink_sock, rcu); | |
ed5d7788 HX |
734 | struct sock *sk = &nlk->sk; |
735 | ||
be82485f XL |
736 | kfree(nlk->groups); |
737 | nlk->groups = NULL; | |
738 | ||
41c6d650 | 739 | if (!refcount_dec_and_test(&sk->sk_refcnt)) |
ed5d7788 HX |
740 | return; |
741 | ||
742 | if (nlk->cb_running && nlk->cb.done) { | |
743 | INIT_WORK(&nlk->work, netlink_sock_destruct_work); | |
744 | schedule_work(&nlk->work); | |
745 | return; | |
746 | } | |
21e4902a | 747 | |
ed5d7788 | 748 | sk_free(sk); |
21e4902a TG |
749 | } |
750 | ||
1da177e4 LT |
751 | static int netlink_release(struct socket *sock) |
752 | { | |
753 | struct sock *sk = sock->sk; | |
754 | struct netlink_sock *nlk; | |
755 | ||
756 | if (!sk) | |
757 | return 0; | |
758 | ||
759 | netlink_remove(sk); | |
ac57b3a9 | 760 | sock_orphan(sk); |
1da177e4 LT |
761 | nlk = nlk_sk(sk); |
762 | ||
3f660d66 HX |
763 | /* |
764 | * OK. Socket is unlinked, any packets that arrive now | |
765 | * will be purged. | |
766 | */ | |
a4c9a56e AK |
767 | if (nlk->netlink_release) |
768 | nlk->netlink_release(sk, nlk->groups); | |
1da177e4 | 769 | |
ee1c2442 JB |
770 | /* must not acquire netlink_table_lock in any way again before unbind |
771 | * and notifying genetlink is done as otherwise it might deadlock | |
772 | */ | |
773 | if (nlk->netlink_unbind) { | |
774 | int i; | |
775 | ||
776 | for (i = 0; i < nlk->ngroups; i++) | |
777 | if (test_bit(i, nlk->groups)) | |
778 | nlk->netlink_unbind(sock_net(sk), i + 1); | |
779 | } | |
780 | if (sk->sk_protocol == NETLINK_GENERIC && | |
781 | atomic_dec_return(&genl_sk_destructing_cnt) == 0) | |
782 | wake_up(&genl_sk_destructing_waitq); | |
783 | ||
1da177e4 LT |
784 | sock->sk = NULL; |
785 | wake_up_interruptible_all(&nlk->wait); | |
786 | ||
787 | skb_queue_purge(&sk->sk_write_queue); | |
788 | ||
e2726020 | 789 | if (nlk->portid && nlk->bound) { |
1da177e4 | 790 | struct netlink_notify n = { |
3b1e0a65 | 791 | .net = sock_net(sk), |
1da177e4 | 792 | .protocol = sk->sk_protocol, |
15e47304 | 793 | .portid = nlk->portid, |
1da177e4 | 794 | }; |
efa172f4 | 795 | blocking_notifier_call_chain(&netlink_chain, |
e041c683 | 796 | NETLINK_URELEASE, &n); |
746fac4d | 797 | } |
4fdb3bb7 | 798 | |
5e7c001c | 799 | module_put(nlk->module); |
4fdb3bb7 | 800 | |
aed81560 | 801 | if (netlink_is_kernel(sk)) { |
b10dcb3b | 802 | netlink_table_grab(); |
869e58f8 DL |
803 | BUG_ON(nl_table[sk->sk_protocol].registered == 0); |
804 | if (--nl_table[sk->sk_protocol].registered == 0) { | |
6d772ac5 ED |
805 | struct listeners *old; |
806 | ||
807 | old = nl_deref_protected(nl_table[sk->sk_protocol].listeners); | |
808 | RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL); | |
809 | kfree_rcu(old, rcu); | |
869e58f8 | 810 | nl_table[sk->sk_protocol].module = NULL; |
9785e10a | 811 | nl_table[sk->sk_protocol].bind = NULL; |
4f520900 | 812 | nl_table[sk->sk_protocol].unbind = NULL; |
9785e10a | 813 | nl_table[sk->sk_protocol].flags = 0; |
869e58f8 DL |
814 | nl_table[sk->sk_protocol].registered = 0; |
815 | } | |
b10dcb3b | 816 | netlink_table_ungrab(); |
658cb354 | 817 | } |
77247bbb | 818 | |
c1fd3b94 | 819 | sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); |
0cafd77d ED |
820 | |
821 | /* Because struct net might disappear soon, do not keep a pointer. */ | |
822 | if (!sk->sk_net_refcnt && sock_net(sk) != &init_net) { | |
823 | __netns_tracker_free(sock_net(sk), &sk->ns_tracker, false); | |
824 | /* Because of deferred_put_nlk_sk and use of work queue, | |
825 | * it is possible netns will be freed before this socket. | |
826 | */ | |
827 | sock_net_set(sk, &init_net); | |
828 | __netns_tracker_alloc(&init_net, &sk->ns_tracker, | |
829 | false, GFP_KERNEL); | |
830 | } | |
21e4902a | 831 | call_rcu(&nlk->rcu, deferred_put_nlk_sk); |
1da177e4 LT |
832 | return 0; |
833 | } | |
834 | ||
835 | static int netlink_autobind(struct socket *sock) | |
836 | { | |
837 | struct sock *sk = sock->sk; | |
3b1e0a65 | 838 | struct net *net = sock_net(sk); |
da12c90e | 839 | struct netlink_table *table = &nl_table[sk->sk_protocol]; |
15e47304 | 840 | s32 portid = task_tgid_vnr(current); |
1da177e4 | 841 | int err; |
b9fbe709 HX |
842 | s32 rover = -4096; |
843 | bool ok; | |
1da177e4 LT |
844 | |
845 | retry: | |
846 | cond_resched(); | |
e341694e | 847 | rcu_read_lock(); |
b9fbe709 HX |
848 | ok = !__netlink_lookup(table, portid, net); |
849 | rcu_read_unlock(); | |
850 | if (!ok) { | |
e341694e | 851 | /* Bind collision, search negative portid values. */ |
b9fbe709 HX |
852 | if (rover == -4096) |
853 | /* rover will be in range [S32_MIN, -4097] */ | |
8032bf12 | 854 | rover = S32_MIN + get_random_u32_below(-4096 - S32_MIN); |
b9fbe709 | 855 | else if (rover >= -4096) |
e341694e | 856 | rover = -4097; |
b9fbe709 | 857 | portid = rover--; |
e341694e | 858 | goto retry; |
1da177e4 | 859 | } |
1da177e4 | 860 | |
8ea65f4a | 861 | err = netlink_insert(sk, portid); |
1da177e4 LT |
862 | if (err == -EADDRINUSE) |
863 | goto retry; | |
d470e3b4 DM |
864 | |
865 | /* If 2 threads race to autobind, that is fine. */ | |
866 | if (err == -EBUSY) | |
867 | err = 0; | |
868 | ||
869 | return err; | |
1da177e4 LT |
870 | } |
871 | ||
aa4cf945 EB |
872 | /** |
873 | * __netlink_ns_capable - General netlink message capability test | |
874 | * @nsp: NETLINK_CB of the socket buffer holding a netlink command from userspace. | |
875 | * @user_ns: The user namespace of the capability to use | |
876 | * @cap: The capability to use | |
877 | * | |
878 | * Test to see if the opener of the socket we received the message | |
879 | * from had when the netlink socket was created and the sender of the | |
85405918 | 880 | * message has the capability @cap in the user namespace @user_ns. |
aa4cf945 EB |
881 | */ |
882 | bool __netlink_ns_capable(const struct netlink_skb_parms *nsp, | |
883 | struct user_namespace *user_ns, int cap) | |
884 | { | |
2d7a85f4 EB |
885 | return ((nsp->flags & NETLINK_SKB_DST) || |
886 | file_ns_capable(nsp->sk->sk_socket->file, user_ns, cap)) && | |
887 | ns_capable(user_ns, cap); | |
aa4cf945 EB |
888 | } |
889 | EXPORT_SYMBOL(__netlink_ns_capable); | |
890 | ||
891 | /** | |
892 | * netlink_ns_capable - General netlink message capability test | |
893 | * @skb: socket buffer holding a netlink command from userspace | |
894 | * @user_ns: The user namespace of the capability to use | |
895 | * @cap: The capability to use | |
896 | * | |
897 | * Test to see if the opener of the socket we received the message | |
898 | * from had when the netlink socket was created and the sender of the | |
85405918 | 899 | * message has the capability @cap in the user namespace @user_ns. |
aa4cf945 EB |
900 | */ |
901 | bool netlink_ns_capable(const struct sk_buff *skb, | |
902 | struct user_namespace *user_ns, int cap) | |
903 | { | |
904 | return __netlink_ns_capable(&NETLINK_CB(skb), user_ns, cap); | |
905 | } | |
906 | EXPORT_SYMBOL(netlink_ns_capable); | |
907 | ||
908 | /** | |
909 | * netlink_capable - Netlink global message capability test | |
910 | * @skb: socket buffer holding a netlink command from userspace | |
911 | * @cap: The capability to use | |
912 | * | |
913 | * Test to see if the opener of the socket we received the message | |
914 | * from had when the netlink socket was created and the sender of the | |
85405918 | 915 | * message has the capability @cap in all user namespaces. |
aa4cf945 EB |
916 | */ |
917 | bool netlink_capable(const struct sk_buff *skb, int cap) | |
918 | { | |
919 | return netlink_ns_capable(skb, &init_user_ns, cap); | |
920 | } | |
921 | EXPORT_SYMBOL(netlink_capable); | |
922 | ||
923 | /** | |
924 | * netlink_net_capable - Netlink network namespace message capability test | |
925 | * @skb: socket buffer holding a netlink command from userspace | |
926 | * @cap: The capability to use | |
927 | * | |
928 | * Test to see if the opener of the socket we received the message | |
929 | * from had when the netlink socket was created and the sender of the | |
85405918 | 930 | * message has the capability @cap over the network namespace of |
aa4cf945 EB |
931 | * the socket we received the message from. |
932 | */ | |
933 | bool netlink_net_capable(const struct sk_buff *skb, int cap) | |
934 | { | |
935 | return netlink_ns_capable(skb, sock_net(skb->sk)->user_ns, cap); | |
936 | } | |
937 | EXPORT_SYMBOL(netlink_net_capable); | |
938 | ||
5187cd05 | 939 | static inline int netlink_allowed(const struct socket *sock, unsigned int flag) |
746fac4d | 940 | { |
9785e10a | 941 | return (nl_table[sock->sk->sk_protocol].flags & flag) || |
df008c91 | 942 | ns_capable(sock_net(sock->sk)->user_ns, CAP_NET_ADMIN); |
746fac4d | 943 | } |
1da177e4 | 944 | |
f7fa9b10 PM |
945 | static void |
946 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
947 | { | |
948 | struct netlink_sock *nlk = nlk_sk(sk); | |
949 | ||
950 | if (nlk->subscriptions && !subscriptions) | |
951 | __sk_del_bind_node(sk); | |
952 | else if (!nlk->subscriptions && subscriptions) | |
953 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
954 | nlk->subscriptions = subscriptions; | |
955 | } | |
956 | ||
b4ff4f04 | 957 | static int netlink_realloc_groups(struct sock *sk) |
513c2500 PM |
958 | { |
959 | struct netlink_sock *nlk = nlk_sk(sk); | |
960 | unsigned int groups; | |
b4ff4f04 | 961 | unsigned long *new_groups; |
513c2500 PM |
962 | int err = 0; |
963 | ||
b4ff4f04 JB |
964 | netlink_table_grab(); |
965 | ||
513c2500 | 966 | groups = nl_table[sk->sk_protocol].groups; |
b4ff4f04 | 967 | if (!nl_table[sk->sk_protocol].registered) { |
513c2500 | 968 | err = -ENOENT; |
b4ff4f04 JB |
969 | goto out_unlock; |
970 | } | |
513c2500 | 971 | |
b4ff4f04 JB |
972 | if (nlk->ngroups >= groups) |
973 | goto out_unlock; | |
513c2500 | 974 | |
b4ff4f04 JB |
975 | new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
976 | if (new_groups == NULL) { | |
977 | err = -ENOMEM; | |
978 | goto out_unlock; | |
979 | } | |
6ac552fd | 980 | memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, |
b4ff4f04 JB |
981 | NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); |
982 | ||
983 | nlk->groups = new_groups; | |
513c2500 | 984 | nlk->ngroups = groups; |
b4ff4f04 JB |
985 | out_unlock: |
986 | netlink_table_ungrab(); | |
987 | return err; | |
513c2500 PM |
988 | } |
989 | ||
02c81ab9 | 990 | static void netlink_undo_bind(int group, long unsigned int groups, |
023e2cfa | 991 | struct sock *sk) |
4f520900 | 992 | { |
023e2cfa | 993 | struct netlink_sock *nlk = nlk_sk(sk); |
4f520900 RGB |
994 | int undo; |
995 | ||
996 | if (!nlk->netlink_unbind) | |
997 | return; | |
998 | ||
999 | for (undo = 0; undo < group; undo++) | |
6251edd9 | 1000 | if (test_bit(undo, &groups)) |
8b7c36d8 | 1001 | nlk->netlink_unbind(sock_net(sk), undo + 1); |
4f520900 RGB |
1002 | } |
1003 | ||
6ac552fd PM |
1004 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, |
1005 | int addr_len) | |
1da177e4 LT |
1006 | { |
1007 | struct sock *sk = sock->sk; | |
3b1e0a65 | 1008 | struct net *net = sock_net(sk); |
1da177e4 LT |
1009 | struct netlink_sock *nlk = nlk_sk(sk); |
1010 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
f7736080 | 1011 | int err = 0; |
d852be84 | 1012 | unsigned long groups; |
da314c99 | 1013 | bool bound; |
746fac4d | 1014 | |
4e4b5376 HFS |
1015 | if (addr_len < sizeof(struct sockaddr_nl)) |
1016 | return -EINVAL; | |
1017 | ||
1da177e4 LT |
1018 | if (nladdr->nl_family != AF_NETLINK) |
1019 | return -EINVAL; | |
d852be84 | 1020 | groups = nladdr->nl_groups; |
1da177e4 LT |
1021 | |
1022 | /* Only superuser is allowed to listen multicasts */ | |
4f520900 | 1023 | if (groups) { |
5187cd05 | 1024 | if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV)) |
513c2500 | 1025 | return -EPERM; |
b4ff4f04 JB |
1026 | err = netlink_realloc_groups(sk); |
1027 | if (err) | |
1028 | return err; | |
513c2500 | 1029 | } |
1da177e4 | 1030 | |
428f944b | 1031 | if (nlk->ngroups < BITS_PER_LONG) |
91874ecf | 1032 | groups &= (1UL << nlk->ngroups) - 1; |
1da177e4 | 1033 | |
7707a4d0 ED |
1034 | /* Paired with WRITE_ONCE() in netlink_insert() */ |
1035 | bound = READ_ONCE(nlk->bound); | |
da314c99 HX |
1036 | if (bound) { |
1037 | /* Ensure nlk->portid is up-to-date. */ | |
1038 | smp_rmb(); | |
1039 | ||
15e47304 | 1040 | if (nladdr->nl_pid != nlk->portid) |
1da177e4 | 1041 | return -EINVAL; |
da314c99 | 1042 | } |
4f520900 RGB |
1043 | |
1044 | if (nlk->netlink_bind && groups) { | |
1045 | int group; | |
1046 | ||
3a20773b NA |
1047 | /* nl_groups is a u32, so cap the maximum groups we can bind */ |
1048 | for (group = 0; group < BITS_PER_TYPE(u32); group++) { | |
4f520900 RGB |
1049 | if (!test_bit(group, &groups)) |
1050 | continue; | |
8b7c36d8 | 1051 | err = nlk->netlink_bind(net, group + 1); |
4f520900 RGB |
1052 | if (!err) |
1053 | continue; | |
023e2cfa | 1054 | netlink_undo_bind(group, groups, sk); |
f2764bd4 | 1055 | return err; |
4f520900 RGB |
1056 | } |
1057 | } | |
1058 | ||
da314c99 HX |
1059 | /* No need for barriers here as we return to user-space without |
1060 | * using any of the bound attributes. | |
1061 | */ | |
f2764bd4 | 1062 | netlink_lock_table(); |
da314c99 | 1063 | if (!bound) { |
1da177e4 | 1064 | err = nladdr->nl_pid ? |
8ea65f4a | 1065 | netlink_insert(sk, nladdr->nl_pid) : |
1da177e4 | 1066 | netlink_autobind(sock); |
4f520900 | 1067 | if (err) { |
3a20773b | 1068 | netlink_undo_bind(BITS_PER_TYPE(u32), groups, sk); |
f7736080 | 1069 | goto unlock; |
4f520900 | 1070 | } |
1da177e4 LT |
1071 | } |
1072 | ||
4f520900 | 1073 | if (!groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
f7736080 XL |
1074 | goto unlock; |
1075 | netlink_unlock_table(); | |
1da177e4 LT |
1076 | |
1077 | netlink_table_grab(); | |
f7fa9b10 | 1078 | netlink_update_subscriptions(sk, nlk->subscriptions + |
4f520900 | 1079 | hweight32(groups) - |
746fac4d | 1080 | hweight32(nlk->groups[0])); |
4f520900 | 1081 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | groups; |
4277a083 | 1082 | netlink_update_listeners(sk); |
1da177e4 LT |
1083 | netlink_table_ungrab(); |
1084 | ||
1085 | return 0; | |
f7736080 XL |
1086 | |
1087 | unlock: | |
1088 | netlink_unlock_table(); | |
1089 | return err; | |
1da177e4 LT |
1090 | } |
1091 | ||
1092 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
1093 | int alen, int flags) | |
1094 | { | |
1095 | int err = 0; | |
1096 | struct sock *sk = sock->sk; | |
1097 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 1098 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
1da177e4 | 1099 | |
6503d961 CG |
1100 | if (alen < sizeof(addr->sa_family)) |
1101 | return -EINVAL; | |
1102 | ||
1da177e4 | 1103 | if (addr->sa_family == AF_UNSPEC) { |
9b663b5c ED |
1104 | /* paired with READ_ONCE() in netlink_getsockbyportid() */ |
1105 | WRITE_ONCE(sk->sk_state, NETLINK_UNCONNECTED); | |
004db64d ED |
1106 | /* dst_portid and dst_group can be read locklessly */ |
1107 | WRITE_ONCE(nlk->dst_portid, 0); | |
1108 | WRITE_ONCE(nlk->dst_group, 0); | |
1da177e4 LT |
1109 | return 0; |
1110 | } | |
1111 | if (addr->sa_family != AF_NETLINK) | |
1112 | return -EINVAL; | |
1113 | ||
78802879 AP |
1114 | if (alen < sizeof(struct sockaddr_nl)) |
1115 | return -EINVAL; | |
1116 | ||
46833a86 | 1117 | if ((nladdr->nl_groups || nladdr->nl_pid) && |
5187cd05 | 1118 | !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND)) |
1da177e4 LT |
1119 | return -EPERM; |
1120 | ||
da314c99 HX |
1121 | /* No need for barriers here as we return to user-space without |
1122 | * using any of the bound attributes. | |
7707a4d0 | 1123 | * Paired with WRITE_ONCE() in netlink_insert(). |
da314c99 | 1124 | */ |
7707a4d0 | 1125 | if (!READ_ONCE(nlk->bound)) |
1da177e4 LT |
1126 | err = netlink_autobind(sock); |
1127 | ||
1128 | if (err == 0) { | |
9b663b5c ED |
1129 | /* paired with READ_ONCE() in netlink_getsockbyportid() */ |
1130 | WRITE_ONCE(sk->sk_state, NETLINK_CONNECTED); | |
004db64d ED |
1131 | /* dst_portid and dst_group can be read locklessly */ |
1132 | WRITE_ONCE(nlk->dst_portid, nladdr->nl_pid); | |
1133 | WRITE_ONCE(nlk->dst_group, ffs(nladdr->nl_groups)); | |
1da177e4 LT |
1134 | } |
1135 | ||
1136 | return err; | |
1137 | } | |
1138 | ||
6ac552fd | 1139 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, |
9b2c45d4 | 1140 | int peer) |
1da177e4 LT |
1141 | { |
1142 | struct sock *sk = sock->sk; | |
1143 | struct netlink_sock *nlk = nlk_sk(sk); | |
13cfa97b | 1144 | DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr); |
746fac4d | 1145 | |
1da177e4 LT |
1146 | nladdr->nl_family = AF_NETLINK; |
1147 | nladdr->nl_pad = 0; | |
1da177e4 LT |
1148 | |
1149 | if (peer) { | |
004db64d ED |
1150 | /* Paired with WRITE_ONCE() in netlink_connect() */ |
1151 | nladdr->nl_pid = READ_ONCE(nlk->dst_portid); | |
1152 | nladdr->nl_groups = netlink_group_mask(READ_ONCE(nlk->dst_group)); | |
1da177e4 | 1153 | } else { |
c1bb9484 ED |
1154 | /* Paired with WRITE_ONCE() in netlink_insert() */ |
1155 | nladdr->nl_pid = READ_ONCE(nlk->portid); | |
f7736080 | 1156 | netlink_lock_table(); |
513c2500 | 1157 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
f7736080 | 1158 | netlink_unlock_table(); |
1da177e4 | 1159 | } |
9b2c45d4 | 1160 | return sizeof(*nladdr); |
1da177e4 LT |
1161 | } |
1162 | ||
025c6818 DD |
1163 | static int netlink_ioctl(struct socket *sock, unsigned int cmd, |
1164 | unsigned long arg) | |
1165 | { | |
1166 | /* try to hand this ioctl down to the NIC drivers. | |
1167 | */ | |
1168 | return -ENOIOCTLCMD; | |
1169 | } | |
1170 | ||
15e47304 | 1171 | static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid) |
1da177e4 | 1172 | { |
1da177e4 LT |
1173 | struct sock *sock; |
1174 | struct netlink_sock *nlk; | |
1175 | ||
15e47304 | 1176 | sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, portid); |
1da177e4 LT |
1177 | if (!sock) |
1178 | return ERR_PTR(-ECONNREFUSED); | |
1179 | ||
1180 | /* Don't bother queuing skb if kernel socket has no input function */ | |
1181 | nlk = nlk_sk(sock); | |
9b663b5c ED |
1182 | /* dst_portid and sk_state can be changed in netlink_connect() */ |
1183 | if (READ_ONCE(sock->sk_state) == NETLINK_CONNECTED && | |
004db64d | 1184 | READ_ONCE(nlk->dst_portid) != nlk_sk(ssk)->portid) { |
1da177e4 LT |
1185 | sock_put(sock); |
1186 | return ERR_PTR(-ECONNREFUSED); | |
1187 | } | |
1188 | return sock; | |
1189 | } | |
1190 | ||
1191 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
1192 | { | |
496ad9aa | 1193 | struct inode *inode = file_inode(filp); |
1da177e4 LT |
1194 | struct sock *sock; |
1195 | ||
1196 | if (!S_ISSOCK(inode->i_mode)) | |
1197 | return ERR_PTR(-ENOTSOCK); | |
1198 | ||
1199 | sock = SOCKET_I(inode)->sk; | |
1200 | if (sock->sk_family != AF_NETLINK) | |
1201 | return ERR_PTR(-EINVAL); | |
1202 | ||
1203 | sock_hold(sock); | |
1204 | return sock; | |
1205 | } | |
1206 | ||
3a36515f PN |
1207 | static struct sk_buff *netlink_alloc_large_skb(unsigned int size, |
1208 | int broadcast) | |
c05cdb1b PNA |
1209 | { |
1210 | struct sk_buff *skb; | |
1211 | void *data; | |
1212 | ||
3a36515f | 1213 | if (size <= NLMSG_GOODSIZE || broadcast) |
c05cdb1b PNA |
1214 | return alloc_skb(size, GFP_KERNEL); |
1215 | ||
3a36515f PN |
1216 | size = SKB_DATA_ALIGN(size) + |
1217 | SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); | |
c05cdb1b PNA |
1218 | |
1219 | data = vmalloc(size); | |
1220 | if (data == NULL) | |
3a36515f | 1221 | return NULL; |
c05cdb1b | 1222 | |
2ea2f62c | 1223 | skb = __build_skb(data, size); |
3a36515f PN |
1224 | if (skb == NULL) |
1225 | vfree(data); | |
2ea2f62c | 1226 | else |
3a36515f | 1227 | skb->destructor = netlink_skb_destructor; |
c05cdb1b PNA |
1228 | |
1229 | return skb; | |
c05cdb1b PNA |
1230 | } |
1231 | ||
1da177e4 LT |
1232 | /* |
1233 | * Attach a skb to a netlink socket. | |
1234 | * The caller must hold a reference to the destination socket. On error, the | |
1235 | * reference is dropped. The skb is not send to the destination, just all | |
1236 | * all error checks are performed and memory in the queue is reserved. | |
1237 | * Return values: | |
1238 | * < 0: error. skb freed, reference to sock dropped. | |
1239 | * 0: continue | |
1240 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
1241 | */ | |
9457afee | 1242 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
c3d8d1e3 | 1243 | long *timeo, struct sock *ssk) |
1da177e4 LT |
1244 | { |
1245 | struct netlink_sock *nlk; | |
1246 | ||
1247 | nlk = nlk_sk(sk); | |
1248 | ||
5fd96123 | 1249 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || |
d1b4c689 | 1250 | test_bit(NETLINK_S_CONGESTED, &nlk->state))) { |
1da177e4 | 1251 | DECLARE_WAITQUEUE(wait, current); |
c3d8d1e3 | 1252 | if (!*timeo) { |
aed81560 | 1253 | if (!ssk || netlink_is_kernel(ssk)) |
1da177e4 LT |
1254 | netlink_overrun(sk); |
1255 | sock_put(sk); | |
1256 | kfree_skb(skb); | |
1257 | return -EAGAIN; | |
1258 | } | |
1259 | ||
1260 | __set_current_state(TASK_INTERRUPTIBLE); | |
1261 | add_wait_queue(&nlk->wait, &wait); | |
1262 | ||
1263 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
cc3a572f | 1264 | test_bit(NETLINK_S_CONGESTED, &nlk->state)) && |
1da177e4 | 1265 | !sock_flag(sk, SOCK_DEAD)) |
c3d8d1e3 | 1266 | *timeo = schedule_timeout(*timeo); |
1da177e4 LT |
1267 | |
1268 | __set_current_state(TASK_RUNNING); | |
1269 | remove_wait_queue(&nlk->wait, &wait); | |
1270 | sock_put(sk); | |
1271 | ||
1272 | if (signal_pending(current)) { | |
1273 | kfree_skb(skb); | |
c3d8d1e3 | 1274 | return sock_intr_errno(*timeo); |
1da177e4 LT |
1275 | } |
1276 | return 1; | |
1277 | } | |
cf0a018a | 1278 | netlink_skb_set_owner_r(skb, sk); |
1da177e4 LT |
1279 | return 0; |
1280 | } | |
1281 | ||
4a7e7c2a | 1282 | static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 1283 | { |
1da177e4 LT |
1284 | int len = skb->len; |
1285 | ||
25e3f70f | 1286 | netlink_deliver_tap(sock_net(sk), skb); |
bcbde0d4 | 1287 | |
d1b4c689 | 1288 | skb_queue_tail(&sk->sk_receive_queue, skb); |
676d2369 | 1289 | sk->sk_data_ready(sk); |
4a7e7c2a ED |
1290 | return len; |
1291 | } | |
1292 | ||
1293 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb) | |
1294 | { | |
1295 | int len = __netlink_sendskb(sk, skb); | |
1296 | ||
1da177e4 LT |
1297 | sock_put(sk); |
1298 | return len; | |
1299 | } | |
1300 | ||
1301 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
1302 | { | |
1303 | kfree_skb(skb); | |
1304 | sock_put(sk); | |
1305 | } | |
1306 | ||
b57ef81f | 1307 | static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation) |
1da177e4 LT |
1308 | { |
1309 | int delta; | |
1310 | ||
1298ca46 | 1311 | WARN_ON(skb->sk != NULL); |
4305b541 | 1312 | delta = skb->end - skb->tail; |
c05cdb1b | 1313 | if (is_vmalloc_addr(skb->head) || delta * 2 < skb->truesize) |
1da177e4 LT |
1314 | return skb; |
1315 | ||
1316 | if (skb_shared(skb)) { | |
1317 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
1318 | if (!nskb) | |
1319 | return skb; | |
8460c00f | 1320 | consume_skb(skb); |
1da177e4 LT |
1321 | skb = nskb; |
1322 | } | |
1323 | ||
158f323b ED |
1324 | pskb_expand_head(skb, 0, -delta, |
1325 | (allocation & ~__GFP_DIRECT_RECLAIM) | | |
1326 | __GFP_NOWARN | __GFP_NORETRY); | |
1da177e4 LT |
1327 | return skb; |
1328 | } | |
1329 | ||
3fbc2905 EB |
1330 | static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb, |
1331 | struct sock *ssk) | |
cd40b7d3 DL |
1332 | { |
1333 | int ret; | |
1334 | struct netlink_sock *nlk = nlk_sk(sk); | |
1335 | ||
1336 | ret = -ECONNREFUSED; | |
1337 | if (nlk->netlink_rcv != NULL) { | |
1338 | ret = skb->len; | |
cf0a018a | 1339 | netlink_skb_set_owner_r(skb, sk); |
e32123e5 | 1340 | NETLINK_CB(skb).sk = ssk; |
73bfd370 | 1341 | netlink_deliver_tap_kernel(sk, ssk, skb); |
cd40b7d3 | 1342 | nlk->netlink_rcv(skb); |
bfb253c9 ED |
1343 | consume_skb(skb); |
1344 | } else { | |
1345 | kfree_skb(skb); | |
cd40b7d3 | 1346 | } |
cd40b7d3 DL |
1347 | sock_put(sk); |
1348 | return ret; | |
1349 | } | |
1350 | ||
1351 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, | |
15e47304 | 1352 | u32 portid, int nonblock) |
1da177e4 LT |
1353 | { |
1354 | struct sock *sk; | |
1355 | int err; | |
1356 | long timeo; | |
1357 | ||
1358 | skb = netlink_trim(skb, gfp_any()); | |
1359 | ||
1360 | timeo = sock_sndtimeo(ssk, nonblock); | |
1361 | retry: | |
15e47304 | 1362 | sk = netlink_getsockbyportid(ssk, portid); |
1da177e4 LT |
1363 | if (IS_ERR(sk)) { |
1364 | kfree_skb(skb); | |
1365 | return PTR_ERR(sk); | |
1366 | } | |
cd40b7d3 | 1367 | if (netlink_is_kernel(sk)) |
3fbc2905 | 1368 | return netlink_unicast_kernel(sk, skb, ssk); |
cd40b7d3 | 1369 | |
b1153f29 | 1370 | if (sk_filter(sk, skb)) { |
84874607 | 1371 | err = skb->len; |
b1153f29 SH |
1372 | kfree_skb(skb); |
1373 | sock_put(sk); | |
1374 | return err; | |
1375 | } | |
1376 | ||
9457afee | 1377 | err = netlink_attachskb(sk, skb, &timeo, ssk); |
1da177e4 LT |
1378 | if (err == 1) |
1379 | goto retry; | |
1380 | if (err) | |
1381 | return err; | |
1382 | ||
7ee015e0 | 1383 | return netlink_sendskb(sk, skb); |
1da177e4 | 1384 | } |
6ac552fd | 1385 | EXPORT_SYMBOL(netlink_unicast); |
1da177e4 | 1386 | |
4277a083 PM |
1387 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
1388 | { | |
1389 | int res = 0; | |
5c398dc8 | 1390 | struct listeners *listeners; |
4277a083 | 1391 | |
aed81560 | 1392 | BUG_ON(!netlink_is_kernel(sk)); |
b4ff4f04 JB |
1393 | |
1394 | rcu_read_lock(); | |
1395 | listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); | |
1396 | ||
6d772ac5 | 1397 | if (listeners && group - 1 < nl_table[sk->sk_protocol].groups) |
5c398dc8 | 1398 | res = test_bit(group - 1, listeners->masks); |
b4ff4f04 JB |
1399 | |
1400 | rcu_read_unlock(); | |
1401 | ||
4277a083 PM |
1402 | return res; |
1403 | } | |
1404 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
1405 | ||
59c28058 JK |
1406 | bool netlink_strict_get_check(struct sk_buff *skb) |
1407 | { | |
8fe08d70 | 1408 | return nlk_test_bit(STRICT_CHK, NETLINK_CB(skb).sk); |
59c28058 JK |
1409 | } |
1410 | EXPORT_SYMBOL_GPL(netlink_strict_get_check); | |
1411 | ||
b57ef81f | 1412 | static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) |
1da177e4 LT |
1413 | { |
1414 | struct netlink_sock *nlk = nlk_sk(sk); | |
1415 | ||
1416 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
cc3a572f | 1417 | !test_bit(NETLINK_S_CONGESTED, &nlk->state)) { |
cf0a018a | 1418 | netlink_skb_set_owner_r(skb, sk); |
4a7e7c2a | 1419 | __netlink_sendskb(sk, skb); |
2c645800 | 1420 | return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1); |
1da177e4 LT |
1421 | } |
1422 | return -1; | |
1423 | } | |
1424 | ||
1425 | struct netlink_broadcast_data { | |
1426 | struct sock *exclude_sk; | |
b4b51029 | 1427 | struct net *net; |
15e47304 | 1428 | u32 portid; |
1da177e4 LT |
1429 | u32 group; |
1430 | int failure; | |
ff491a73 | 1431 | int delivery_failure; |
1da177e4 LT |
1432 | int congested; |
1433 | int delivered; | |
7d877f3b | 1434 | gfp_t allocation; |
1da177e4 | 1435 | struct sk_buff *skb, *skb2; |
a3377386 AK |
1436 | int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data); |
1437 | void *tx_data; | |
1da177e4 LT |
1438 | }; |
1439 | ||
46c9521f RR |
1440 | static void do_one_broadcast(struct sock *sk, |
1441 | struct netlink_broadcast_data *p) | |
1da177e4 LT |
1442 | { |
1443 | struct netlink_sock *nlk = nlk_sk(sk); | |
1444 | int val; | |
1445 | ||
1446 | if (p->exclude_sk == sk) | |
46c9521f | 1447 | return; |
1da177e4 | 1448 | |
15e47304 | 1449 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
f7fa9b10 | 1450 | !test_bit(p->group - 1, nlk->groups)) |
46c9521f | 1451 | return; |
1da177e4 | 1452 | |
59324cf3 | 1453 | if (!net_eq(sock_net(sk), p->net)) { |
8fe08d70 | 1454 | if (!nlk_test_bit(LISTEN_ALL_NSID, sk)) |
59324cf3 ND |
1455 | return; |
1456 | ||
1457 | if (!peernet_has_id(sock_net(sk), p->net)) | |
1458 | return; | |
1459 | ||
1460 | if (!file_ns_capable(sk->sk_socket->file, p->net->user_ns, | |
1461 | CAP_NET_BROADCAST)) | |
1462 | return; | |
1463 | } | |
b4b51029 | 1464 | |
1da177e4 LT |
1465 | if (p->failure) { |
1466 | netlink_overrun(sk); | |
46c9521f | 1467 | return; |
1da177e4 LT |
1468 | } |
1469 | ||
1470 | sock_hold(sk); | |
1471 | if (p->skb2 == NULL) { | |
68acc024 | 1472 | if (skb_shared(p->skb)) { |
1da177e4 LT |
1473 | p->skb2 = skb_clone(p->skb, p->allocation); |
1474 | } else { | |
68acc024 TC |
1475 | p->skb2 = skb_get(p->skb); |
1476 | /* | |
1477 | * skb ownership may have been set when | |
1478 | * delivered to a previous socket. | |
1479 | */ | |
1480 | skb_orphan(p->skb2); | |
1da177e4 LT |
1481 | } |
1482 | } | |
1483 | if (p->skb2 == NULL) { | |
1484 | netlink_overrun(sk); | |
1485 | /* Clone failed. Notify ALL listeners. */ | |
1486 | p->failure = 1; | |
8fe08d70 | 1487 | if (nlk_test_bit(BROADCAST_SEND_ERROR, sk)) |
be0c22a4 | 1488 | p->delivery_failure = 1; |
59324cf3 ND |
1489 | goto out; |
1490 | } | |
a3377386 AK |
1491 | |
1492 | if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) { | |
1493 | kfree_skb(p->skb2); | |
1494 | p->skb2 = NULL; | |
1495 | goto out; | |
1496 | } | |
1497 | ||
59324cf3 | 1498 | if (sk_filter(sk, p->skb2)) { |
b1153f29 SH |
1499 | kfree_skb(p->skb2); |
1500 | p->skb2 = NULL; | |
59324cf3 ND |
1501 | goto out; |
1502 | } | |
1503 | NETLINK_CB(p->skb2).nsid = peernet2id(sock_net(sk), p->net); | |
7212462f ND |
1504 | if (NETLINK_CB(p->skb2).nsid != NETNSA_NSID_NOT_ASSIGNED) |
1505 | NETLINK_CB(p->skb2).nsid_is_set = true; | |
59324cf3 ND |
1506 | val = netlink_broadcast_deliver(sk, p->skb2); |
1507 | if (val < 0) { | |
1da177e4 | 1508 | netlink_overrun(sk); |
8fe08d70 | 1509 | if (nlk_test_bit(BROADCAST_SEND_ERROR, sk)) |
be0c22a4 | 1510 | p->delivery_failure = 1; |
1da177e4 LT |
1511 | } else { |
1512 | p->congested |= val; | |
1513 | p->delivered = 1; | |
1514 | p->skb2 = NULL; | |
1515 | } | |
59324cf3 | 1516 | out: |
1da177e4 | 1517 | sock_put(sk); |
1da177e4 LT |
1518 | } |
1519 | ||
a3377386 AK |
1520 | int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, |
1521 | u32 portid, | |
1522 | u32 group, gfp_t allocation, | |
1523 | int (*filter)(struct sock *dsk, | |
1524 | struct sk_buff *skb, void *data), | |
1525 | void *filter_data) | |
1da177e4 | 1526 | { |
3b1e0a65 | 1527 | struct net *net = sock_net(ssk); |
1da177e4 | 1528 | struct netlink_broadcast_data info; |
1da177e4 LT |
1529 | struct sock *sk; |
1530 | ||
1531 | skb = netlink_trim(skb, allocation); | |
1532 | ||
1533 | info.exclude_sk = ssk; | |
b4b51029 | 1534 | info.net = net; |
15e47304 | 1535 | info.portid = portid; |
1da177e4 LT |
1536 | info.group = group; |
1537 | info.failure = 0; | |
ff491a73 | 1538 | info.delivery_failure = 0; |
1da177e4 LT |
1539 | info.congested = 0; |
1540 | info.delivered = 0; | |
1541 | info.allocation = allocation; | |
1542 | info.skb = skb; | |
1543 | info.skb2 = NULL; | |
a3377386 AK |
1544 | info.tx_filter = filter; |
1545 | info.tx_data = filter_data; | |
1da177e4 LT |
1546 | |
1547 | /* While we sleep in clone, do not allow to change socket list */ | |
1548 | ||
1549 | netlink_lock_table(); | |
1550 | ||
b67bfe0d | 1551 | sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
1da177e4 LT |
1552 | do_one_broadcast(sk, &info); |
1553 | ||
70d4bf6d | 1554 | consume_skb(skb); |
aa1c6a6f | 1555 | |
1da177e4 LT |
1556 | netlink_unlock_table(); |
1557 | ||
70d4bf6d NH |
1558 | if (info.delivery_failure) { |
1559 | kfree_skb(info.skb2); | |
ff491a73 | 1560 | return -ENOBUFS; |
658cb354 ED |
1561 | } |
1562 | consume_skb(info.skb2); | |
ff491a73 | 1563 | |
1da177e4 | 1564 | if (info.delivered) { |
d0164adc | 1565 | if (info.congested && gfpflags_allow_blocking(allocation)) |
1da177e4 LT |
1566 | yield(); |
1567 | return 0; | |
1568 | } | |
1da177e4 LT |
1569 | return -ESRCH; |
1570 | } | |
a3377386 AK |
1571 | EXPORT_SYMBOL(netlink_broadcast_filtered); |
1572 | ||
1573 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 portid, | |
1574 | u32 group, gfp_t allocation) | |
1575 | { | |
1576 | return netlink_broadcast_filtered(ssk, skb, portid, group, allocation, | |
1577 | NULL, NULL); | |
1578 | } | |
6ac552fd | 1579 | EXPORT_SYMBOL(netlink_broadcast); |
1da177e4 LT |
1580 | |
1581 | struct netlink_set_err_data { | |
1582 | struct sock *exclude_sk; | |
15e47304 | 1583 | u32 portid; |
1da177e4 LT |
1584 | u32 group; |
1585 | int code; | |
1586 | }; | |
1587 | ||
b57ef81f | 1588 | static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p) |
1da177e4 LT |
1589 | { |
1590 | struct netlink_sock *nlk = nlk_sk(sk); | |
1a50307b | 1591 | int ret = 0; |
1da177e4 LT |
1592 | |
1593 | if (sk == p->exclude_sk) | |
1594 | goto out; | |
1595 | ||
09ad9bc7 | 1596 | if (!net_eq(sock_net(sk), sock_net(p->exclude_sk))) |
b4b51029 EB |
1597 | goto out; |
1598 | ||
15e47304 | 1599 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
f7fa9b10 | 1600 | !test_bit(p->group - 1, nlk->groups)) |
1da177e4 LT |
1601 | goto out; |
1602 | ||
8fe08d70 | 1603 | if (p->code == ENOBUFS && nlk_test_bit(RECV_NO_ENOBUFS, sk)) { |
1a50307b PNA |
1604 | ret = 1; |
1605 | goto out; | |
1606 | } | |
1607 | ||
d0f95894 | 1608 | WRITE_ONCE(sk->sk_err, p->code); |
e3ae2365 | 1609 | sk_error_report(sk); |
1da177e4 | 1610 | out: |
1a50307b | 1611 | return ret; |
1da177e4 LT |
1612 | } |
1613 | ||
4843b93c PNA |
1614 | /** |
1615 | * netlink_set_err - report error to broadcast listeners | |
1616 | * @ssk: the kernel netlink socket, as returned by netlink_kernel_create() | |
15e47304 | 1617 | * @portid: the PORTID of a process that we want to skip (if any) |
840e93f2 | 1618 | * @group: the broadcast group that will notice the error |
4843b93c | 1619 | * @code: error code, must be negative (as usual in kernelspace) |
1a50307b PNA |
1620 | * |
1621 | * This function returns the number of broadcast listeners that have set the | |
cc3a572f | 1622 | * NETLINK_NO_ENOBUFS socket option. |
4843b93c | 1623 | */ |
15e47304 | 1624 | int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code) |
1da177e4 LT |
1625 | { |
1626 | struct netlink_set_err_data info; | |
8d61f926 | 1627 | unsigned long flags; |
1da177e4 | 1628 | struct sock *sk; |
1a50307b | 1629 | int ret = 0; |
1da177e4 LT |
1630 | |
1631 | info.exclude_sk = ssk; | |
15e47304 | 1632 | info.portid = portid; |
1da177e4 | 1633 | info.group = group; |
4843b93c PNA |
1634 | /* sk->sk_err wants a positive error value */ |
1635 | info.code = -code; | |
1da177e4 | 1636 | |
8d61f926 | 1637 | read_lock_irqsave(&nl_table_lock, flags); |
1da177e4 | 1638 | |
b67bfe0d | 1639 | sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
1a50307b | 1640 | ret += do_one_set_err(sk, &info); |
1da177e4 | 1641 | |
8d61f926 | 1642 | read_unlock_irqrestore(&nl_table_lock, flags); |
1a50307b | 1643 | return ret; |
1da177e4 | 1644 | } |
dd5b6ce6 | 1645 | EXPORT_SYMBOL(netlink_set_err); |
1da177e4 | 1646 | |
84659eb5 JB |
1647 | /* must be called with netlink table grabbed */ |
1648 | static void netlink_update_socket_mc(struct netlink_sock *nlk, | |
1649 | unsigned int group, | |
1650 | int is_new) | |
1651 | { | |
1652 | int old, new = !!is_new, subscriptions; | |
1653 | ||
1654 | old = test_bit(group - 1, nlk->groups); | |
1655 | subscriptions = nlk->subscriptions - old + new; | |
b8e39b38 | 1656 | __assign_bit(group - 1, nlk->groups, new); |
84659eb5 JB |
1657 | netlink_update_subscriptions(&nlk->sk, subscriptions); |
1658 | netlink_update_listeners(&nlk->sk); | |
1659 | } | |
1660 | ||
9a4595bc | 1661 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
a7b75c5a | 1662 | sockptr_t optval, unsigned int optlen) |
9a4595bc PM |
1663 | { |
1664 | struct sock *sk = sock->sk; | |
1665 | struct netlink_sock *nlk = nlk_sk(sk); | |
eb496534 | 1666 | unsigned int val = 0; |
8fe08d70 | 1667 | int nr = -1; |
9a4595bc PM |
1668 | |
1669 | if (level != SOL_NETLINK) | |
1670 | return -ENOPROTOOPT; | |
1671 | ||
d1b4c689 | 1672 | if (optlen >= sizeof(int) && |
a7b75c5a | 1673 | copy_from_sockptr(&val, optval, sizeof(val))) |
9a4595bc PM |
1674 | return -EFAULT; |
1675 | ||
1676 | switch (optname) { | |
1677 | case NETLINK_PKTINFO: | |
8fe08d70 | 1678 | nr = NETLINK_F_RECV_PKTINFO; |
9a4595bc PM |
1679 | break; |
1680 | case NETLINK_ADD_MEMBERSHIP: | |
1681 | case NETLINK_DROP_MEMBERSHIP: { | |
8fe08d70 ED |
1682 | int err; |
1683 | ||
5187cd05 | 1684 | if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV)) |
9a4595bc | 1685 | return -EPERM; |
b4ff4f04 JB |
1686 | err = netlink_realloc_groups(sk); |
1687 | if (err) | |
1688 | return err; | |
9a4595bc PM |
1689 | if (!val || val - 1 >= nlk->ngroups) |
1690 | return -EINVAL; | |
7774d5e0 | 1691 | if (optname == NETLINK_ADD_MEMBERSHIP && nlk->netlink_bind) { |
023e2cfa | 1692 | err = nlk->netlink_bind(sock_net(sk), val); |
4f520900 RGB |
1693 | if (err) |
1694 | return err; | |
1695 | } | |
9a4595bc | 1696 | netlink_table_grab(); |
84659eb5 JB |
1697 | netlink_update_socket_mc(nlk, val, |
1698 | optname == NETLINK_ADD_MEMBERSHIP); | |
9a4595bc | 1699 | netlink_table_ungrab(); |
7774d5e0 | 1700 | if (optname == NETLINK_DROP_MEMBERSHIP && nlk->netlink_unbind) |
023e2cfa | 1701 | nlk->netlink_unbind(sock_net(sk), val); |
03292745 | 1702 | |
9a4595bc PM |
1703 | break; |
1704 | } | |
be0c22a4 | 1705 | case NETLINK_BROADCAST_ERROR: |
8fe08d70 | 1706 | nr = NETLINK_F_BROADCAST_SEND_ERROR; |
be0c22a4 | 1707 | break; |
38938bfe | 1708 | case NETLINK_NO_ENOBUFS: |
8fe08d70 | 1709 | assign_bit(NETLINK_F_RECV_NO_ENOBUFS, &nlk->flags, val); |
38938bfe | 1710 | if (val) { |
cc3a572f | 1711 | clear_bit(NETLINK_S_CONGESTED, &nlk->state); |
38938bfe | 1712 | wake_up_interruptible(&nlk->wait); |
658cb354 | 1713 | } |
38938bfe | 1714 | break; |
59324cf3 ND |
1715 | case NETLINK_LISTEN_ALL_NSID: |
1716 | if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_BROADCAST)) | |
1717 | return -EPERM; | |
8fe08d70 | 1718 | nr = NETLINK_F_LISTEN_ALL_NSID; |
59324cf3 | 1719 | break; |
0a6a3a23 | 1720 | case NETLINK_CAP_ACK: |
8fe08d70 | 1721 | nr = NETLINK_F_CAP_ACK; |
0a6a3a23 | 1722 | break; |
2d4bc933 | 1723 | case NETLINK_EXT_ACK: |
8fe08d70 | 1724 | nr = NETLINK_F_EXT_ACK; |
2d4bc933 | 1725 | break; |
d3e8869e | 1726 | case NETLINK_GET_STRICT_CHK: |
8fe08d70 | 1727 | nr = NETLINK_F_STRICT_CHK; |
89d35528 | 1728 | break; |
9a4595bc | 1729 | default: |
8fe08d70 | 1730 | return -ENOPROTOOPT; |
9a4595bc | 1731 | } |
8fe08d70 ED |
1732 | if (nr >= 0) |
1733 | assign_bit(nr, &nlk->flags, val); | |
1734 | return 0; | |
9a4595bc PM |
1735 | } |
1736 | ||
1737 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
746fac4d | 1738 | char __user *optval, int __user *optlen) |
9a4595bc PM |
1739 | { |
1740 | struct sock *sk = sock->sk; | |
1741 | struct netlink_sock *nlk = nlk_sk(sk); | |
d913d32c KI |
1742 | unsigned int flag; |
1743 | int len, val; | |
9a4595bc PM |
1744 | |
1745 | if (level != SOL_NETLINK) | |
1746 | return -ENOPROTOOPT; | |
1747 | ||
1748 | if (get_user(len, optlen)) | |
1749 | return -EFAULT; | |
1750 | if (len < 0) | |
1751 | return -EINVAL; | |
1752 | ||
1753 | switch (optname) { | |
1754 | case NETLINK_PKTINFO: | |
d913d32c | 1755 | flag = NETLINK_F_RECV_PKTINFO; |
9a4595bc | 1756 | break; |
be0c22a4 | 1757 | case NETLINK_BROADCAST_ERROR: |
d913d32c | 1758 | flag = NETLINK_F_BROADCAST_SEND_ERROR; |
be0c22a4 | 1759 | break; |
38938bfe | 1760 | case NETLINK_NO_ENOBUFS: |
d913d32c | 1761 | flag = NETLINK_F_RECV_NO_ENOBUFS; |
38938bfe | 1762 | break; |
b42be38b | 1763 | case NETLINK_LIST_MEMBERSHIPS: { |
d913d32c | 1764 | int pos, idx, shift, err = 0; |
b42be38b | 1765 | |
47191d65 | 1766 | netlink_lock_table(); |
b42be38b DR |
1767 | for (pos = 0; pos * 8 < nlk->ngroups; pos += sizeof(u32)) { |
1768 | if (len - pos < sizeof(u32)) | |
1769 | break; | |
1770 | ||
1771 | idx = pos / sizeof(unsigned long); | |
1772 | shift = (pos % sizeof(unsigned long)) * 8; | |
1773 | if (put_user((u32)(nlk->groups[idx] >> shift), | |
1774 | (u32 __user *)(optval + pos))) { | |
1775 | err = -EFAULT; | |
1776 | break; | |
1777 | } | |
1778 | } | |
f4e45348 | 1779 | if (put_user(ALIGN(BITS_TO_BYTES(nlk->ngroups), sizeof(u32)), optlen)) |
b42be38b | 1780 | err = -EFAULT; |
47191d65 | 1781 | netlink_unlock_table(); |
d913d32c | 1782 | return err; |
b42be38b | 1783 | } |
0a6a3a23 | 1784 | case NETLINK_CAP_ACK: |
d913d32c | 1785 | flag = NETLINK_F_CAP_ACK; |
0a6a3a23 | 1786 | break; |
2d4bc933 | 1787 | case NETLINK_EXT_ACK: |
d913d32c | 1788 | flag = NETLINK_F_EXT_ACK; |
2d4bc933 | 1789 | break; |
d3e8869e | 1790 | case NETLINK_GET_STRICT_CHK: |
d913d32c | 1791 | flag = NETLINK_F_STRICT_CHK; |
89d35528 | 1792 | break; |
9a4595bc | 1793 | default: |
d913d32c | 1794 | return -ENOPROTOOPT; |
9a4595bc | 1795 | } |
d913d32c KI |
1796 | |
1797 | if (len < sizeof(int)) | |
1798 | return -EINVAL; | |
1799 | ||
1800 | len = sizeof(int); | |
8fe08d70 | 1801 | val = test_bit(flag, &nlk->flags); |
d913d32c KI |
1802 | |
1803 | if (put_user(len, optlen) || | |
1804 | copy_to_user(optval, &val, len)) | |
1805 | return -EFAULT; | |
1806 | ||
1807 | return 0; | |
9a4595bc PM |
1808 | } |
1809 | ||
1810 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
1811 | { | |
1812 | struct nl_pktinfo info; | |
1813 | ||
1814 | info.group = NETLINK_CB(skb).dst_group; | |
1815 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
1816 | } | |
1817 | ||
59324cf3 ND |
1818 | static void netlink_cmsg_listen_all_nsid(struct sock *sk, struct msghdr *msg, |
1819 | struct sk_buff *skb) | |
1820 | { | |
1821 | if (!NETLINK_CB(skb).nsid_is_set) | |
1822 | return; | |
1823 | ||
1824 | put_cmsg(msg, SOL_NETLINK, NETLINK_LISTEN_ALL_NSID, sizeof(int), | |
1825 | &NETLINK_CB(skb).nsid); | |
1826 | } | |
1827 | ||
1b784140 | 1828 | static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) |
1da177e4 | 1829 | { |
1da177e4 LT |
1830 | struct sock *sk = sock->sk; |
1831 | struct netlink_sock *nlk = nlk_sk(sk); | |
342dfc30 | 1832 | DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name); |
15e47304 | 1833 | u32 dst_portid; |
d629b836 | 1834 | u32 dst_group; |
1da177e4 LT |
1835 | struct sk_buff *skb; |
1836 | int err; | |
1837 | struct scm_cookie scm; | |
2d7a85f4 | 1838 | u32 netlink_skb_flags = 0; |
1da177e4 | 1839 | |
4d11af5d | 1840 | if (msg->msg_flags & MSG_OOB) |
1da177e4 LT |
1841 | return -EOPNOTSUPP; |
1842 | ||
f123cffd HM |
1843 | if (len == 0) { |
1844 | pr_warn_once("Zero length message leads to an empty skb\n"); | |
1845 | return -ENODATA; | |
1846 | } | |
1847 | ||
7cc05662 | 1848 | err = scm_send(sock, msg, &scm, true); |
1da177e4 LT |
1849 | if (err < 0) |
1850 | return err; | |
1851 | ||
1852 | if (msg->msg_namelen) { | |
b47030c7 | 1853 | err = -EINVAL; |
6091f09c ED |
1854 | if (msg->msg_namelen < sizeof(struct sockaddr_nl)) |
1855 | goto out; | |
1da177e4 | 1856 | if (addr->nl_family != AF_NETLINK) |
b47030c7 | 1857 | goto out; |
15e47304 | 1858 | dst_portid = addr->nl_pid; |
d629b836 | 1859 | dst_group = ffs(addr->nl_groups); |
b47030c7 | 1860 | err = -EPERM; |
15e47304 | 1861 | if ((dst_group || dst_portid) && |
5187cd05 | 1862 | !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND)) |
b47030c7 | 1863 | goto out; |
2d7a85f4 | 1864 | netlink_skb_flags |= NETLINK_SKB_DST; |
1da177e4 | 1865 | } else { |
004db64d ED |
1866 | /* Paired with WRITE_ONCE() in netlink_connect() */ |
1867 | dst_portid = READ_ONCE(nlk->dst_portid); | |
1868 | dst_group = READ_ONCE(nlk->dst_group); | |
1da177e4 LT |
1869 | } |
1870 | ||
7707a4d0 ED |
1871 | /* Paired with WRITE_ONCE() in netlink_insert() */ |
1872 | if (!READ_ONCE(nlk->bound)) { | |
1da177e4 LT |
1873 | err = netlink_autobind(sock); |
1874 | if (err) | |
1875 | goto out; | |
da314c99 HX |
1876 | } else { |
1877 | /* Ensure nlk is hashed and visible. */ | |
1878 | smp_rmb(); | |
1da177e4 LT |
1879 | } |
1880 | ||
1881 | err = -EMSGSIZE; | |
1882 | if (len > sk->sk_sndbuf - 32) | |
1883 | goto out; | |
1884 | err = -ENOBUFS; | |
3a36515f | 1885 | skb = netlink_alloc_large_skb(len, dst_group); |
6ac552fd | 1886 | if (skb == NULL) |
1da177e4 LT |
1887 | goto out; |
1888 | ||
15e47304 | 1889 | NETLINK_CB(skb).portid = nlk->portid; |
d629b836 | 1890 | NETLINK_CB(skb).dst_group = dst_group; |
7cc05662 | 1891 | NETLINK_CB(skb).creds = scm.creds; |
2d7a85f4 | 1892 | NETLINK_CB(skb).flags = netlink_skb_flags; |
1da177e4 | 1893 | |
1da177e4 | 1894 | err = -EFAULT; |
6ce8e9ce | 1895 | if (memcpy_from_msg(skb_put(skb, len), msg, len)) { |
1da177e4 LT |
1896 | kfree_skb(skb); |
1897 | goto out; | |
1898 | } | |
1899 | ||
1900 | err = security_netlink_send(sk, skb); | |
1901 | if (err) { | |
1902 | kfree_skb(skb); | |
1903 | goto out; | |
1904 | } | |
1905 | ||
d629b836 | 1906 | if (dst_group) { |
63354797 | 1907 | refcount_inc(&skb->users); |
15e47304 | 1908 | netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL); |
1da177e4 | 1909 | } |
4d11af5d | 1910 | err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags & MSG_DONTWAIT); |
1da177e4 LT |
1911 | |
1912 | out: | |
7cc05662 | 1913 | scm_destroy(&scm); |
1da177e4 LT |
1914 | return err; |
1915 | } | |
1916 | ||
1b784140 | 1917 | static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, |
1da177e4 LT |
1918 | int flags) |
1919 | { | |
1da177e4 LT |
1920 | struct scm_cookie scm; |
1921 | struct sock *sk = sock->sk; | |
1922 | struct netlink_sock *nlk = nlk_sk(sk); | |
a1865f2e | 1923 | size_t copied, max_recvmsg_len; |
68d6ac6d | 1924 | struct sk_buff *skb, *data_skb; |
b44d211e | 1925 | int err, ret; |
1da177e4 | 1926 | |
4d11af5d | 1927 | if (flags & MSG_OOB) |
1da177e4 LT |
1928 | return -EOPNOTSUPP; |
1929 | ||
1930 | copied = 0; | |
1931 | ||
f4b41f06 | 1932 | skb = skb_recv_datagram(sk, flags, &err); |
6ac552fd | 1933 | if (skb == NULL) |
1da177e4 LT |
1934 | goto out; |
1935 | ||
68d6ac6d JB |
1936 | data_skb = skb; |
1937 | ||
1dacc76d JB |
1938 | #ifdef CONFIG_COMPAT_NETLINK_MESSAGES |
1939 | if (unlikely(skb_shinfo(skb)->frag_list)) { | |
1dacc76d | 1940 | /* |
68d6ac6d JB |
1941 | * If this skb has a frag_list, then here that means that we |
1942 | * will have to use the frag_list skb's data for compat tasks | |
1943 | * and the regular skb's data for normal (non-compat) tasks. | |
1dacc76d | 1944 | * |
68d6ac6d JB |
1945 | * If we need to send the compat skb, assign it to the |
1946 | * 'data_skb' variable so that it will be used below for data | |
1947 | * copying. We keep 'skb' for everything else, including | |
1948 | * freeing both later. | |
1dacc76d | 1949 | */ |
68d6ac6d JB |
1950 | if (flags & MSG_CMSG_COMPAT) |
1951 | data_skb = skb_shinfo(skb)->frag_list; | |
1dacc76d JB |
1952 | } |
1953 | #endif | |
1954 | ||
9063e21f | 1955 | /* Record the max length of recvmsg() calls for future allocations */ |
a1865f2e ED |
1956 | max_recvmsg_len = max(READ_ONCE(nlk->max_recvmsg_len), len); |
1957 | max_recvmsg_len = min_t(size_t, max_recvmsg_len, | |
1958 | SKB_WITH_OVERHEAD(32768)); | |
1959 | WRITE_ONCE(nlk->max_recvmsg_len, max_recvmsg_len); | |
9063e21f | 1960 | |
68d6ac6d | 1961 | copied = data_skb->len; |
1da177e4 LT |
1962 | if (len < copied) { |
1963 | msg->msg_flags |= MSG_TRUNC; | |
1964 | copied = len; | |
1965 | } | |
1966 | ||
51f3d02b | 1967 | err = skb_copy_datagram_msg(data_skb, 0, msg, copied); |
1da177e4 LT |
1968 | |
1969 | if (msg->msg_name) { | |
342dfc30 | 1970 | DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name); |
1da177e4 LT |
1971 | addr->nl_family = AF_NETLINK; |
1972 | addr->nl_pad = 0; | |
15e47304 | 1973 | addr->nl_pid = NETLINK_CB(skb).portid; |
d629b836 | 1974 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
1975 | msg->msg_namelen = sizeof(*addr); |
1976 | } | |
1977 | ||
8fe08d70 | 1978 | if (nlk_test_bit(RECV_PKTINFO, sk)) |
cc9a06cd | 1979 | netlink_cmsg_recv_pktinfo(msg, skb); |
8fe08d70 | 1980 | if (nlk_test_bit(LISTEN_ALL_NSID, sk)) |
59324cf3 | 1981 | netlink_cmsg_listen_all_nsid(sk, msg, skb); |
cc9a06cd | 1982 | |
7cc05662 CH |
1983 | memset(&scm, 0, sizeof(scm)); |
1984 | scm.creds = *NETLINK_CREDS(skb); | |
188ccb55 | 1985 | if (flags & MSG_TRUNC) |
68d6ac6d | 1986 | copied = data_skb->len; |
daa3766e | 1987 | |
1da177e4 LT |
1988 | skb_free_datagram(sk, skb); |
1989 | ||
a939d149 | 1990 | if (READ_ONCE(nlk->cb_running) && |
16b304f3 | 1991 | atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) { |
b44d211e AV |
1992 | ret = netlink_dump(sk); |
1993 | if (ret) { | |
d0f95894 | 1994 | WRITE_ONCE(sk->sk_err, -ret); |
e3ae2365 | 1995 | sk_error_report(sk); |
b44d211e AV |
1996 | } |
1997 | } | |
1da177e4 | 1998 | |
7cc05662 | 1999 | scm_recv(sock, msg, &scm, flags); |
1da177e4 LT |
2000 | out: |
2001 | netlink_rcv_wake(sk); | |
2002 | return err ? : copied; | |
2003 | } | |
2004 | ||
676d2369 | 2005 | static void netlink_data_ready(struct sock *sk) |
1da177e4 | 2006 | { |
cd40b7d3 | 2007 | BUG(); |
1da177e4 LT |
2008 | } |
2009 | ||
2010 | /* | |
746fac4d | 2011 | * We export these functions to other modules. They provide a |
1da177e4 LT |
2012 | * complete set of kernel non-blocking support for message |
2013 | * queueing. | |
2014 | */ | |
2015 | ||
2016 | struct sock * | |
9f00d977 PNA |
2017 | __netlink_kernel_create(struct net *net, int unit, struct module *module, |
2018 | struct netlink_kernel_cfg *cfg) | |
1da177e4 LT |
2019 | { |
2020 | struct socket *sock; | |
2021 | struct sock *sk; | |
77247bbb | 2022 | struct netlink_sock *nlk; |
5c398dc8 | 2023 | struct listeners *listeners = NULL; |
a31f2d17 PNA |
2024 | struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL; |
2025 | unsigned int groups; | |
1da177e4 | 2026 | |
fab2caf6 | 2027 | BUG_ON(!nl_table); |
1da177e4 | 2028 | |
6ac552fd | 2029 | if (unit < 0 || unit >= MAX_LINKS) |
1da177e4 LT |
2030 | return NULL; |
2031 | ||
2032 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
2033 | return NULL; | |
13d3078e EB |
2034 | |
2035 | if (__netlink_create(net, sock, cb_mutex, unit, 1) < 0) | |
23fe1866 PE |
2036 | goto out_sock_release_nosk; |
2037 | ||
2038 | sk = sock->sk; | |
4fdb3bb7 | 2039 | |
a31f2d17 | 2040 | if (!cfg || cfg->groups < 32) |
4277a083 | 2041 | groups = 32; |
a31f2d17 PNA |
2042 | else |
2043 | groups = cfg->groups; | |
4277a083 | 2044 | |
5c398dc8 | 2045 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
4277a083 PM |
2046 | if (!listeners) |
2047 | goto out_sock_release; | |
2048 | ||
1da177e4 | 2049 | sk->sk_data_ready = netlink_data_ready; |
a31f2d17 PNA |
2050 | if (cfg && cfg->input) |
2051 | nlk_sk(sk)->netlink_rcv = cfg->input; | |
1da177e4 | 2052 | |
8ea65f4a | 2053 | if (netlink_insert(sk, 0)) |
77247bbb | 2054 | goto out_sock_release; |
4fdb3bb7 | 2055 | |
77247bbb | 2056 | nlk = nlk_sk(sk); |
8fe08d70 | 2057 | set_bit(NETLINK_F_KERNEL_SOCKET, &nlk->flags); |
4fdb3bb7 | 2058 | |
4fdb3bb7 | 2059 | netlink_table_grab(); |
b4b51029 EB |
2060 | if (!nl_table[unit].registered) { |
2061 | nl_table[unit].groups = groups; | |
5c398dc8 | 2062 | rcu_assign_pointer(nl_table[unit].listeners, listeners); |
b4b51029 EB |
2063 | nl_table[unit].cb_mutex = cb_mutex; |
2064 | nl_table[unit].module = module; | |
9785e10a PNA |
2065 | if (cfg) { |
2066 | nl_table[unit].bind = cfg->bind; | |
6251edd9 | 2067 | nl_table[unit].unbind = cfg->unbind; |
a4c9a56e | 2068 | nl_table[unit].release = cfg->release; |
9785e10a PNA |
2069 | nl_table[unit].flags = cfg->flags; |
2070 | } | |
b4b51029 | 2071 | nl_table[unit].registered = 1; |
f937f1f4 JJ |
2072 | } else { |
2073 | kfree(listeners); | |
869e58f8 | 2074 | nl_table[unit].registered++; |
b4b51029 | 2075 | } |
4fdb3bb7 | 2076 | netlink_table_ungrab(); |
77247bbb PM |
2077 | return sk; |
2078 | ||
4fdb3bb7 | 2079 | out_sock_release: |
4277a083 | 2080 | kfree(listeners); |
9dfbec1f | 2081 | netlink_kernel_release(sk); |
23fe1866 PE |
2082 | return NULL; |
2083 | ||
2084 | out_sock_release_nosk: | |
4fdb3bb7 | 2085 | sock_release(sock); |
77247bbb | 2086 | return NULL; |
1da177e4 | 2087 | } |
9f00d977 | 2088 | EXPORT_SYMBOL(__netlink_kernel_create); |
b7c6ba6e DL |
2089 | |
2090 | void | |
2091 | netlink_kernel_release(struct sock *sk) | |
2092 | { | |
13d3078e EB |
2093 | if (sk == NULL || sk->sk_socket == NULL) |
2094 | return; | |
2095 | ||
2096 | sock_release(sk->sk_socket); | |
b7c6ba6e DL |
2097 | } |
2098 | EXPORT_SYMBOL(netlink_kernel_release); | |
2099 | ||
d136f1bd | 2100 | int __netlink_change_ngroups(struct sock *sk, unsigned int groups) |
b4ff4f04 | 2101 | { |
5c398dc8 | 2102 | struct listeners *new, *old; |
b4ff4f04 | 2103 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; |
b4ff4f04 JB |
2104 | |
2105 | if (groups < 32) | |
2106 | groups = 32; | |
2107 | ||
b4ff4f04 | 2108 | if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { |
5c398dc8 ED |
2109 | new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC); |
2110 | if (!new) | |
d136f1bd | 2111 | return -ENOMEM; |
6d772ac5 | 2112 | old = nl_deref_protected(tbl->listeners); |
5c398dc8 ED |
2113 | memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups)); |
2114 | rcu_assign_pointer(tbl->listeners, new); | |
2115 | ||
37b6b935 | 2116 | kfree_rcu(old, rcu); |
b4ff4f04 JB |
2117 | } |
2118 | tbl->groups = groups; | |
2119 | ||
d136f1bd JB |
2120 | return 0; |
2121 | } | |
2122 | ||
2123 | /** | |
2124 | * netlink_change_ngroups - change number of multicast groups | |
2125 | * | |
2126 | * This changes the number of multicast groups that are available | |
2127 | * on a certain netlink family. Note that it is not possible to | |
2128 | * change the number of groups to below 32. Also note that it does | |
2129 | * not implicitly call netlink_clear_multicast_users() when the | |
2130 | * number of groups is reduced. | |
2131 | * | |
2132 | * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). | |
2133 | * @groups: The new number of groups. | |
2134 | */ | |
2135 | int netlink_change_ngroups(struct sock *sk, unsigned int groups) | |
2136 | { | |
2137 | int err; | |
2138 | ||
2139 | netlink_table_grab(); | |
2140 | err = __netlink_change_ngroups(sk, groups); | |
b4ff4f04 | 2141 | netlink_table_ungrab(); |
d136f1bd | 2142 | |
b4ff4f04 JB |
2143 | return err; |
2144 | } | |
b4ff4f04 | 2145 | |
b8273570 JB |
2146 | void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group) |
2147 | { | |
2148 | struct sock *sk; | |
b8273570 JB |
2149 | struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; |
2150 | ||
b67bfe0d | 2151 | sk_for_each_bound(sk, &tbl->mc_list) |
b8273570 JB |
2152 | netlink_update_socket_mc(nlk_sk(sk), group, 0); |
2153 | } | |
2154 | ||
a46621a3 | 2155 | struct nlmsghdr * |
15e47304 | 2156 | __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags) |
a46621a3 DV |
2157 | { |
2158 | struct nlmsghdr *nlh; | |
573ce260 | 2159 | int size = nlmsg_msg_size(len); |
a46621a3 | 2160 | |
4df864c1 | 2161 | nlh = skb_put(skb, NLMSG_ALIGN(size)); |
a46621a3 DV |
2162 | nlh->nlmsg_type = type; |
2163 | nlh->nlmsg_len = size; | |
2164 | nlh->nlmsg_flags = flags; | |
15e47304 | 2165 | nlh->nlmsg_pid = portid; |
a46621a3 DV |
2166 | nlh->nlmsg_seq = seq; |
2167 | if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0) | |
573ce260 | 2168 | memset(nlmsg_data(nlh) + len, 0, NLMSG_ALIGN(size) - size); |
a46621a3 DV |
2169 | return nlh; |
2170 | } | |
2171 | EXPORT_SYMBOL(__nlmsg_put); | |
2172 | ||
1da177e4 LT |
2173 | /* |
2174 | * It looks a bit ugly. | |
2175 | * It would be better to create kernel thread. | |
2176 | */ | |
2177 | ||
e11eb32d DS |
2178 | static int netlink_dump_done(struct netlink_sock *nlk, struct sk_buff *skb, |
2179 | struct netlink_callback *cb, | |
2180 | struct netlink_ext_ack *extack) | |
2181 | { | |
2182 | struct nlmsghdr *nlh; | |
2183 | ||
2184 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(nlk->dump_done_errno), | |
2185 | NLM_F_MULTI | cb->answer_flags); | |
2186 | if (WARN_ON(!nlh)) | |
2187 | return -ENOBUFS; | |
2188 | ||
2189 | nl_dump_check_consistent(cb, nlh); | |
2190 | memcpy(nlmsg_data(nlh), &nlk->dump_done_errno, sizeof(nlk->dump_done_errno)); | |
2191 | ||
8fe08d70 | 2192 | if (extack->_msg && test_bit(NETLINK_F_EXT_ACK, &nlk->flags)) { |
e11eb32d DS |
2193 | nlh->nlmsg_flags |= NLM_F_ACK_TLVS; |
2194 | if (!nla_put_string(skb, NLMSGERR_ATTR_MSG, extack->_msg)) | |
2195 | nlmsg_end(skb, nlh); | |
2196 | } | |
2197 | ||
2198 | return 0; | |
2199 | } | |
2200 | ||
1da177e4 LT |
2201 | static int netlink_dump(struct sock *sk) |
2202 | { | |
2203 | struct netlink_sock *nlk = nlk_sk(sk); | |
4a19edb6 | 2204 | struct netlink_ext_ack extack = {}; |
1da177e4 | 2205 | struct netlink_callback *cb; |
c7ac8679 | 2206 | struct sk_buff *skb = NULL; |
a1865f2e | 2207 | size_t max_recvmsg_len; |
92964c79 | 2208 | struct module *module; |
0642840b | 2209 | int err = -ENOBUFS; |
db65a3aa | 2210 | int alloc_min_size; |
c7ac8679 | 2211 | int alloc_size; |
1da177e4 | 2212 | |
af65bdfc | 2213 | mutex_lock(nlk->cb_mutex); |
16b304f3 | 2214 | if (!nlk->cb_running) { |
bf8b79e4 TG |
2215 | err = -EINVAL; |
2216 | goto errout_skb; | |
1da177e4 LT |
2217 | } |
2218 | ||
d1b4c689 | 2219 | if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) |
f9c22888 | 2220 | goto errout_skb; |
9063e21f ED |
2221 | |
2222 | /* NLMSG_GOODSIZE is small to avoid high order allocations being | |
2223 | * required, but it makes sense to _attempt_ a 16K bytes allocation | |
2224 | * to reduce number of system calls on dump operations, if user | |
2225 | * ever provided a big enough buffer. | |
2226 | */ | |
db65a3aa AR |
2227 | cb = &nlk->cb; |
2228 | alloc_min_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE); | |
2229 | ||
a1865f2e ED |
2230 | max_recvmsg_len = READ_ONCE(nlk->max_recvmsg_len); |
2231 | if (alloc_min_size < max_recvmsg_len) { | |
2232 | alloc_size = max_recvmsg_len; | |
d35c99ff ED |
2233 | skb = alloc_skb(alloc_size, |
2234 | (GFP_KERNEL & ~__GFP_DIRECT_RECLAIM) | | |
2235 | __GFP_NOWARN | __GFP_NORETRY); | |
9063e21f | 2236 | } |
db65a3aa AR |
2237 | if (!skb) { |
2238 | alloc_size = alloc_min_size; | |
c5b0db32 | 2239 | skb = alloc_skb(alloc_size, GFP_KERNEL); |
db65a3aa | 2240 | } |
c7ac8679 | 2241 | if (!skb) |
c63d6ea3 | 2242 | goto errout_skb; |
db65a3aa AR |
2243 | |
2244 | /* Trim skb to allocated size. User is expected to provide buffer as | |
2245 | * large as max(min_dump_alloc, 16KiB (mac_recvmsg_len capped at | |
2246 | * netlink_recvmsg())). dump will pack as many smaller messages as | |
2247 | * could fit within the allocated skb. skb is typically allocated | |
2248 | * with larger space than required (could be as much as near 2x the | |
2249 | * requested size with align to next power of 2 approach). Allowing | |
2250 | * dump to use the excess space makes it difficult for a user to have a | |
2251 | * reasonable static buffer based on the expected largest dump of a | |
2252 | * single netdev. The outcome is MSG_TRUNC error. | |
2253 | */ | |
d1b4c689 | 2254 | skb_reserve(skb, skb_tailroom(skb) - alloc_size); |
99c07327 ED |
2255 | |
2256 | /* Make sure malicious BPF programs can not read unitialized memory | |
2257 | * from skb->head -> skb->data | |
2258 | */ | |
2259 | skb_reset_network_header(skb); | |
2260 | skb_reset_mac_header(skb); | |
2261 | ||
f9c22888 | 2262 | netlink_skb_set_owner_r(skb, sk); |
c7ac8679 | 2263 | |
4a19edb6 DA |
2264 | if (nlk->dump_done_errno > 0) { |
2265 | cb->extack = &extack; | |
0642840b | 2266 | nlk->dump_done_errno = cb->dump(skb, cb); |
4a19edb6 DA |
2267 | cb->extack = NULL; |
2268 | } | |
1da177e4 | 2269 | |
0642840b JD |
2270 | if (nlk->dump_done_errno > 0 || |
2271 | skb_tailroom(skb) < nlmsg_total_size(sizeof(nlk->dump_done_errno))) { | |
af65bdfc | 2272 | mutex_unlock(nlk->cb_mutex); |
b1153f29 SH |
2273 | |
2274 | if (sk_filter(sk, skb)) | |
2275 | kfree_skb(skb); | |
4a7e7c2a ED |
2276 | else |
2277 | __netlink_sendskb(sk, skb); | |
1da177e4 LT |
2278 | return 0; |
2279 | } | |
2280 | ||
e11eb32d | 2281 | if (netlink_dump_done(nlk, skb, cb, &extack)) |
bf8b79e4 TG |
2282 | goto errout_skb; |
2283 | ||
e11eb32d DS |
2284 | #ifdef CONFIG_COMPAT_NETLINK_MESSAGES |
2285 | /* frag_list skb's data is used for compat tasks | |
2286 | * and the regular skb's data for normal (non-compat) tasks. | |
2287 | * See netlink_recvmsg(). | |
2288 | */ | |
2289 | if (unlikely(skb_shinfo(skb)->frag_list)) { | |
2290 | if (netlink_dump_done(nlk, skb_shinfo(skb)->frag_list, cb, &extack)) | |
2291 | goto errout_skb; | |
4a19edb6 | 2292 | } |
e11eb32d | 2293 | #endif |
4a19edb6 | 2294 | |
b1153f29 SH |
2295 | if (sk_filter(sk, skb)) |
2296 | kfree_skb(skb); | |
4a7e7c2a ED |
2297 | else |
2298 | __netlink_sendskb(sk, skb); | |
1da177e4 | 2299 | |
a8f74b22 TG |
2300 | if (cb->done) |
2301 | cb->done(cb); | |
1da177e4 | 2302 | |
a939d149 | 2303 | WRITE_ONCE(nlk->cb_running, false); |
92964c79 HX |
2304 | module = cb->module; |
2305 | skb = cb->skb; | |
16b304f3 | 2306 | mutex_unlock(nlk->cb_mutex); |
92964c79 HX |
2307 | module_put(module); |
2308 | consume_skb(skb); | |
1da177e4 | 2309 | return 0; |
1797754e | 2310 | |
bf8b79e4 | 2311 | errout_skb: |
af65bdfc | 2312 | mutex_unlock(nlk->cb_mutex); |
bf8b79e4 | 2313 | kfree_skb(skb); |
bf8b79e4 | 2314 | return err; |
1da177e4 LT |
2315 | } |
2316 | ||
6dc878a8 G |
2317 | int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, |
2318 | const struct nlmsghdr *nlh, | |
2319 | struct netlink_dump_control *control) | |
1da177e4 LT |
2320 | { |
2321 | struct netlink_callback *cb; | |
8fe08d70 | 2322 | struct netlink_sock *nlk; |
1da177e4 | 2323 | struct sock *sk; |
b44d211e | 2324 | int ret; |
1da177e4 | 2325 | |
63354797 | 2326 | refcount_inc(&skb->users); |
f9c22888 | 2327 | |
15e47304 | 2328 | sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).portid); |
1da177e4 | 2329 | if (sk == NULL) { |
16b304f3 PS |
2330 | ret = -ECONNREFUSED; |
2331 | goto error_free; | |
1da177e4 | 2332 | } |
6dc878a8 | 2333 | |
16b304f3 | 2334 | nlk = nlk_sk(sk); |
af65bdfc | 2335 | mutex_lock(nlk->cb_mutex); |
6dc878a8 | 2336 | /* A dump is in progress... */ |
16b304f3 | 2337 | if (nlk->cb_running) { |
6dc878a8 | 2338 | ret = -EBUSY; |
16b304f3 | 2339 | goto error_unlock; |
1da177e4 | 2340 | } |
6dc878a8 | 2341 | /* add reference of module which cb->dump belongs to */ |
16b304f3 | 2342 | if (!try_module_get(control->module)) { |
6dc878a8 | 2343 | ret = -EPROTONOSUPPORT; |
16b304f3 | 2344 | goto error_unlock; |
6dc878a8 G |
2345 | } |
2346 | ||
16b304f3 PS |
2347 | cb = &nlk->cb; |
2348 | memset(cb, 0, sizeof(*cb)); | |
2349 | cb->dump = control->dump; | |
2350 | cb->done = control->done; | |
2351 | cb->nlh = nlh; | |
2352 | cb->data = control->data; | |
2353 | cb->module = control->module; | |
2354 | cb->min_dump_alloc = control->min_dump_alloc; | |
2355 | cb->skb = skb; | |
2356 | ||
8fe08d70 | 2357 | cb->strict_check = nlk_test_bit(STRICT_CHK, NETLINK_CB(skb).sk); |
89d35528 | 2358 | |
3730cf4d | 2359 | if (control->start) { |
5ab8c41c | 2360 | cb->extack = control->extack; |
3730cf4d | 2361 | ret = control->start(cb); |
5ab8c41c | 2362 | cb->extack = NULL; |
41c87425 | 2363 | if (ret) |
b87b6194 | 2364 | goto error_put; |
41c87425 JD |
2365 | } |
2366 | ||
a939d149 | 2367 | WRITE_ONCE(nlk->cb_running, true); |
0642840b | 2368 | nlk->dump_done_errno = INT_MAX; |
16b304f3 | 2369 | |
af65bdfc | 2370 | mutex_unlock(nlk->cb_mutex); |
1da177e4 | 2371 | |
41c87425 | 2372 | ret = netlink_dump(sk); |
fc9e50f5 | 2373 | |
1da177e4 | 2374 | sock_put(sk); |
5c58298c | 2375 | |
b44d211e AV |
2376 | if (ret) |
2377 | return ret; | |
2378 | ||
5c58298c DL |
2379 | /* We successfully started a dump, by returning -EINTR we |
2380 | * signal not to send ACK even if it was requested. | |
2381 | */ | |
2382 | return -EINTR; | |
16b304f3 | 2383 | |
b87b6194 JD |
2384 | error_put: |
2385 | module_put(control->module); | |
16b304f3 PS |
2386 | error_unlock: |
2387 | sock_put(sk); | |
2388 | mutex_unlock(nlk->cb_mutex); | |
2389 | error_free: | |
2390 | kfree_skb(skb); | |
2391 | return ret; | |
1da177e4 | 2392 | } |
6dc878a8 | 2393 | EXPORT_SYMBOL(__netlink_dump_start); |
1da177e4 | 2394 | |
0c95cea2 JK |
2395 | static size_t |
2396 | netlink_ack_tlv_len(struct netlink_sock *nlk, int err, | |
2397 | const struct netlink_ext_ack *extack) | |
2398 | { | |
2399 | size_t tlvlen; | |
2400 | ||
8fe08d70 | 2401 | if (!extack || !test_bit(NETLINK_F_EXT_ACK, &nlk->flags)) |
0c95cea2 JK |
2402 | return 0; |
2403 | ||
2404 | tlvlen = 0; | |
2405 | if (extack->_msg) | |
2406 | tlvlen += nla_total_size(strlen(extack->_msg) + 1); | |
2407 | if (extack->cookie_len) | |
2408 | tlvlen += nla_total_size(extack->cookie_len); | |
2409 | ||
2410 | /* Following attributes are only reported as error (not warning) */ | |
2411 | if (!err) | |
2412 | return tlvlen; | |
2413 | ||
2414 | if (extack->bad_attr) | |
2415 | tlvlen += nla_total_size(sizeof(u32)); | |
2416 | if (extack->policy) | |
2417 | tlvlen += netlink_policy_dump_attr_size_estimate(extack->policy); | |
690252f1 JK |
2418 | if (extack->miss_type) |
2419 | tlvlen += nla_total_size(sizeof(u32)); | |
2420 | if (extack->miss_nest) | |
2421 | tlvlen += nla_total_size(sizeof(u32)); | |
0c95cea2 JK |
2422 | |
2423 | return tlvlen; | |
2424 | } | |
2425 | ||
2426 | static void | |
2427 | netlink_ack_tlv_fill(struct sk_buff *in_skb, struct sk_buff *skb, | |
2428 | struct nlmsghdr *nlh, int err, | |
2429 | const struct netlink_ext_ack *extack) | |
2430 | { | |
2431 | if (extack->_msg) | |
2432 | WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG, extack->_msg)); | |
2433 | if (extack->cookie_len) | |
2434 | WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE, | |
2435 | extack->cookie_len, extack->cookie)); | |
2436 | ||
2437 | if (!err) | |
2438 | return; | |
2439 | ||
2440 | if (extack->bad_attr && | |
2441 | !WARN_ON((u8 *)extack->bad_attr < in_skb->data || | |
2442 | (u8 *)extack->bad_attr >= in_skb->data + in_skb->len)) | |
2443 | WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS, | |
2444 | (u8 *)extack->bad_attr - (u8 *)nlh)); | |
2445 | if (extack->policy) | |
2446 | netlink_policy_dump_write_attr(skb, extack->policy, | |
2447 | NLMSGERR_ATTR_POLICY); | |
690252f1 JK |
2448 | if (extack->miss_type) |
2449 | WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_MISS_TYPE, | |
2450 | extack->miss_type)); | |
2451 | if (extack->miss_nest && | |
2452 | !WARN_ON((u8 *)extack->miss_nest < in_skb->data || | |
2453 | (u8 *)extack->miss_nest > in_skb->data + in_skb->len)) | |
2454 | WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_MISS_NEST, | |
2455 | (u8 *)extack->miss_nest - (u8 *)nlh)); | |
0c95cea2 JK |
2456 | } |
2457 | ||
2d4bc933 JB |
2458 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, |
2459 | const struct netlink_ext_ack *extack) | |
1da177e4 LT |
2460 | { |
2461 | struct sk_buff *skb; | |
2462 | struct nlmsghdr *rep; | |
2463 | struct nlmsgerr *errmsg; | |
339bf98f | 2464 | size_t payload = sizeof(*errmsg); |
0a6a3a23 | 2465 | struct netlink_sock *nlk = nlk_sk(NETLINK_CB(in_skb).sk); |
2d4bc933 | 2466 | unsigned int flags = 0; |
0c95cea2 | 2467 | size_t tlvlen; |
1da177e4 | 2468 | |
0a6a3a23 | 2469 | /* Error messages get the original request appened, unless the user |
2d4bc933 JB |
2470 | * requests to cap the error message, and get extra error data if |
2471 | * requested. | |
0a6a3a23 | 2472 | */ |
8fe08d70 | 2473 | if (err && !test_bit(NETLINK_F_CAP_ACK, &nlk->flags)) |
fe2a31d7 MK |
2474 | payload += nlmsg_len(nlh); |
2475 | else | |
2d4bc933 | 2476 | flags |= NLM_F_CAPPED; |
1da177e4 | 2477 | |
0c95cea2 | 2478 | tlvlen = netlink_ack_tlv_len(nlk, err, extack); |
2d4bc933 JB |
2479 | if (tlvlen) |
2480 | flags |= NLM_F_ACK_TLVS; | |
2481 | ||
2482 | skb = nlmsg_new(payload + tlvlen, GFP_KERNEL); | |
738136a0 | 2483 | if (!skb) |
e6976148 | 2484 | goto err_skb; |
1da177e4 | 2485 | |
710d21fd | 2486 | rep = nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, |
738136a0 JK |
2487 | NLMSG_ERROR, sizeof(*errmsg), flags); |
2488 | if (!rep) | |
2489 | goto err_bad_put; | |
bf8b79e4 | 2490 | errmsg = nlmsg_data(rep); |
1da177e4 | 2491 | errmsg->error = err; |
738136a0 JK |
2492 | errmsg->msg = *nlh; |
2493 | ||
2494 | if (!(flags & NLM_F_CAPPED)) { | |
2495 | if (!nlmsg_append(skb, nlmsg_len(nlh))) | |
2496 | goto err_bad_put; | |
2497 | ||
c73a72f4 | 2498 | memcpy(nlmsg_data(&errmsg->msg), nlmsg_data(nlh), |
738136a0 JK |
2499 | nlmsg_len(nlh)); |
2500 | } | |
2d4bc933 | 2501 | |
0c95cea2 JK |
2502 | if (tlvlen) |
2503 | netlink_ack_tlv_fill(in_skb, skb, nlh, err, extack); | |
2d4bc933 JB |
2504 | |
2505 | nlmsg_end(skb, rep); | |
2506 | ||
01757f53 | 2507 | nlmsg_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid); |
738136a0 JK |
2508 | |
2509 | return; | |
2510 | ||
2511 | err_bad_put: | |
e6976148 TC |
2512 | nlmsg_free(skb); |
2513 | err_skb: | |
d0f95894 | 2514 | WRITE_ONCE(NETLINK_CB(in_skb).sk->sk_err, ENOBUFS); |
738136a0 | 2515 | sk_error_report(NETLINK_CB(in_skb).sk); |
1da177e4 | 2516 | } |
6ac552fd | 2517 | EXPORT_SYMBOL(netlink_ack); |
1da177e4 | 2518 | |
cd40b7d3 | 2519 | int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
2d4bc933 JB |
2520 | struct nlmsghdr *, |
2521 | struct netlink_ext_ack *)) | |
82ace47a | 2522 | { |
cbbdf843 | 2523 | struct netlink_ext_ack extack; |
82ace47a TG |
2524 | struct nlmsghdr *nlh; |
2525 | int err; | |
2526 | ||
2527 | while (skb->len >= nlmsg_total_size(0)) { | |
cd40b7d3 DL |
2528 | int msglen; |
2529 | ||
cd443f1e | 2530 | memset(&extack, 0, sizeof(extack)); |
b529ccf2 | 2531 | nlh = nlmsg_hdr(skb); |
d35b6856 | 2532 | err = 0; |
82ace47a | 2533 | |
ad8e4b75 | 2534 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
2535 | return 0; |
2536 | ||
d35b6856 TG |
2537 | /* Only requests are handled by the kernel */ |
2538 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | |
5c58298c | 2539 | goto ack; |
45e7ae7f TG |
2540 | |
2541 | /* Skip control messages */ | |
2542 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | |
5c58298c | 2543 | goto ack; |
d35b6856 | 2544 | |
2d4bc933 | 2545 | err = cb(skb, nlh, &extack); |
5c58298c DL |
2546 | if (err == -EINTR) |
2547 | goto skip; | |
2548 | ||
2549 | ack: | |
d35b6856 | 2550 | if (nlh->nlmsg_flags & NLM_F_ACK || err) |
2d4bc933 | 2551 | netlink_ack(skb, nlh, err, &extack); |
82ace47a | 2552 | |
5c58298c | 2553 | skip: |
6ac552fd | 2554 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
cd40b7d3 DL |
2555 | if (msglen > skb->len) |
2556 | msglen = skb->len; | |
2557 | skb_pull(skb, msglen); | |
82ace47a TG |
2558 | } |
2559 | ||
2560 | return 0; | |
2561 | } | |
6ac552fd | 2562 | EXPORT_SYMBOL(netlink_rcv_skb); |
82ace47a | 2563 | |
d387f6ad TG |
2564 | /** |
2565 | * nlmsg_notify - send a notification netlink message | |
2566 | * @sk: netlink socket to use | |
2567 | * @skb: notification message | |
15e47304 | 2568 | * @portid: destination netlink portid for reports or 0 |
d387f6ad TG |
2569 | * @group: destination multicast group or 0 |
2570 | * @report: 1 to report back, 0 to disable | |
2571 | * @flags: allocation flags | |
2572 | */ | |
15e47304 | 2573 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, |
d387f6ad TG |
2574 | unsigned int group, int report, gfp_t flags) |
2575 | { | |
2576 | int err = 0; | |
2577 | ||
2578 | if (group) { | |
15e47304 | 2579 | int exclude_portid = 0; |
d387f6ad TG |
2580 | |
2581 | if (report) { | |
63354797 | 2582 | refcount_inc(&skb->users); |
15e47304 | 2583 | exclude_portid = portid; |
d387f6ad TG |
2584 | } |
2585 | ||
1ce85fe4 PNA |
2586 | /* errors reported via destination sk->sk_err, but propagate |
2587 | * delivery errors if NETLINK_BROADCAST_ERROR flag is set */ | |
15e47304 | 2588 | err = nlmsg_multicast(sk, skb, exclude_portid, group, flags); |
fef773fc YD |
2589 | if (err == -ESRCH) |
2590 | err = 0; | |
d387f6ad TG |
2591 | } |
2592 | ||
1ce85fe4 PNA |
2593 | if (report) { |
2594 | int err2; | |
2595 | ||
15e47304 | 2596 | err2 = nlmsg_unicast(sk, skb, portid); |
fef773fc | 2597 | if (!err) |
1ce85fe4 PNA |
2598 | err = err2; |
2599 | } | |
d387f6ad TG |
2600 | |
2601 | return err; | |
2602 | } | |
6ac552fd | 2603 | EXPORT_SYMBOL(nlmsg_notify); |
d387f6ad | 2604 | |
1da177e4 LT |
2605 | #ifdef CONFIG_PROC_FS |
2606 | struct nl_seq_iter { | |
e372c414 | 2607 | struct seq_net_private p; |
56d28b1e | 2608 | struct rhashtable_iter hti; |
1da177e4 | 2609 | int link; |
1da177e4 LT |
2610 | }; |
2611 | ||
abf9979f | 2612 | static void netlink_walk_start(struct nl_seq_iter *iter) |
1da177e4 | 2613 | { |
6c4128f6 | 2614 | rhashtable_walk_enter(&nl_table[iter->link].hash, &iter->hti); |
97a6ec4a | 2615 | rhashtable_walk_start(&iter->hti); |
1da177e4 LT |
2616 | } |
2617 | ||
56d28b1e | 2618 | static void netlink_walk_stop(struct nl_seq_iter *iter) |
1da177e4 | 2619 | { |
56d28b1e HX |
2620 | rhashtable_walk_stop(&iter->hti); |
2621 | rhashtable_walk_exit(&iter->hti); | |
1da177e4 LT |
2622 | } |
2623 | ||
56d28b1e | 2624 | static void *__netlink_seq_next(struct seq_file *seq) |
1da177e4 | 2625 | { |
56d28b1e | 2626 | struct nl_seq_iter *iter = seq->private; |
e341694e | 2627 | struct netlink_sock *nlk; |
1da177e4 | 2628 | |
56d28b1e HX |
2629 | do { |
2630 | for (;;) { | |
56d28b1e | 2631 | nlk = rhashtable_walk_next(&iter->hti); |
746fac4d | 2632 | |
56d28b1e HX |
2633 | if (IS_ERR(nlk)) { |
2634 | if (PTR_ERR(nlk) == -EAGAIN) | |
2635 | continue; | |
e341694e | 2636 | |
56d28b1e HX |
2637 | return nlk; |
2638 | } | |
1da177e4 | 2639 | |
56d28b1e HX |
2640 | if (nlk) |
2641 | break; | |
1da177e4 | 2642 | |
56d28b1e HX |
2643 | netlink_walk_stop(iter); |
2644 | if (++iter->link >= MAX_LINKS) | |
2645 | return NULL; | |
da12c90e | 2646 | |
abf9979f | 2647 | netlink_walk_start(iter); |
1da177e4 | 2648 | } |
56d28b1e | 2649 | } while (sock_net(&nlk->sk) != seq_file_net(seq)); |
1da177e4 | 2650 | |
56d28b1e HX |
2651 | return nlk; |
2652 | } | |
1da177e4 | 2653 | |
56d28b1e | 2654 | static void *netlink_seq_start(struct seq_file *seq, loff_t *posp) |
64fbca01 | 2655 | __acquires(RCU) |
56d28b1e HX |
2656 | { |
2657 | struct nl_seq_iter *iter = seq->private; | |
2658 | void *obj = SEQ_START_TOKEN; | |
2659 | loff_t pos; | |
56d28b1e HX |
2660 | |
2661 | iter->link = 0; | |
2662 | ||
abf9979f | 2663 | netlink_walk_start(iter); |
56d28b1e HX |
2664 | |
2665 | for (pos = *posp; pos && obj && !IS_ERR(obj); pos--) | |
2666 | obj = __netlink_seq_next(seq); | |
2667 | ||
2668 | return obj; | |
2669 | } | |
2670 | ||
2671 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
2672 | { | |
2673 | ++*pos; | |
2674 | return __netlink_seq_next(seq); | |
1da177e4 LT |
2675 | } |
2676 | ||
138d0be3 | 2677 | static void netlink_native_seq_stop(struct seq_file *seq, void *v) |
1da177e4 | 2678 | { |
56d28b1e HX |
2679 | struct nl_seq_iter *iter = seq->private; |
2680 | ||
2681 | if (iter->link >= MAX_LINKS) | |
2682 | return; | |
2683 | ||
2684 | netlink_walk_stop(iter); | |
1da177e4 LT |
2685 | } |
2686 | ||
2687 | ||
138d0be3 | 2688 | static int netlink_native_seq_show(struct seq_file *seq, void *v) |
1da177e4 | 2689 | { |
658cb354 | 2690 | if (v == SEQ_START_TOKEN) { |
1da177e4 | 2691 | seq_puts(seq, |
ae552ac2 YB |
2692 | "sk Eth Pid Groups " |
2693 | "Rmem Wmem Dump Locks Drops Inode\n"); | |
658cb354 | 2694 | } else { |
1da177e4 LT |
2695 | struct sock *s = v; |
2696 | struct netlink_sock *nlk = nlk_sk(s); | |
2697 | ||
ea9a0379 | 2698 | seq_printf(seq, "%pK %-3d %-10u %08x %-8d %-8d %-5d %-8d %-8u %-8lu\n", |
1da177e4 LT |
2699 | s, |
2700 | s->sk_protocol, | |
15e47304 | 2701 | nlk->portid, |
513c2500 | 2702 | nlk->groups ? (u32)nlk->groups[0] : 0, |
31e6d363 ED |
2703 | sk_rmem_alloc_get(s), |
2704 | sk_wmem_alloc_get(s), | |
a939d149 | 2705 | READ_ONCE(nlk->cb_running), |
41c6d650 | 2706 | refcount_read(&s->sk_refcnt), |
cf0aa4e0 MY |
2707 | atomic_read(&s->sk_drops), |
2708 | sock_i_ino(s) | |
1da177e4 LT |
2709 | ); |
2710 | ||
2711 | } | |
2712 | return 0; | |
2713 | } | |
2714 | ||
138d0be3 YS |
2715 | #ifdef CONFIG_BPF_SYSCALL |
2716 | struct bpf_iter__netlink { | |
2717 | __bpf_md_ptr(struct bpf_iter_meta *, meta); | |
2718 | __bpf_md_ptr(struct netlink_sock *, sk); | |
2719 | }; | |
2720 | ||
2721 | DEFINE_BPF_ITER_FUNC(netlink, struct bpf_iter_meta *meta, struct netlink_sock *sk) | |
2722 | ||
2723 | static int netlink_prog_seq_show(struct bpf_prog *prog, | |
2724 | struct bpf_iter_meta *meta, | |
2725 | void *v) | |
2726 | { | |
2727 | struct bpf_iter__netlink ctx; | |
2728 | ||
2729 | meta->seq_num--; /* skip SEQ_START_TOKEN */ | |
2730 | ctx.meta = meta; | |
2731 | ctx.sk = nlk_sk((struct sock *)v); | |
2732 | return bpf_iter_run_prog(prog, &ctx); | |
2733 | } | |
2734 | ||
2735 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
2736 | { | |
2737 | struct bpf_iter_meta meta; | |
2738 | struct bpf_prog *prog; | |
2739 | ||
2740 | meta.seq = seq; | |
2741 | prog = bpf_iter_get_info(&meta, false); | |
2742 | if (!prog) | |
2743 | return netlink_native_seq_show(seq, v); | |
2744 | ||
2745 | if (v != SEQ_START_TOKEN) | |
2746 | return netlink_prog_seq_show(prog, &meta, v); | |
2747 | ||
2748 | return 0; | |
2749 | } | |
2750 | ||
2751 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
2752 | { | |
2753 | struct bpf_iter_meta meta; | |
2754 | struct bpf_prog *prog; | |
2755 | ||
2756 | if (!v) { | |
2757 | meta.seq = seq; | |
2758 | prog = bpf_iter_get_info(&meta, true); | |
2759 | if (prog) | |
2760 | (void)netlink_prog_seq_show(prog, &meta, v); | |
2761 | } | |
2762 | ||
2763 | netlink_native_seq_stop(seq, v); | |
2764 | } | |
2765 | #else | |
2766 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
2767 | { | |
2768 | return netlink_native_seq_show(seq, v); | |
2769 | } | |
2770 | ||
2771 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
2772 | { | |
2773 | netlink_native_seq_stop(seq, v); | |
2774 | } | |
2775 | #endif | |
2776 | ||
56b3d975 | 2777 | static const struct seq_operations netlink_seq_ops = { |
1da177e4 LT |
2778 | .start = netlink_seq_start, |
2779 | .next = netlink_seq_next, | |
2780 | .stop = netlink_seq_stop, | |
2781 | .show = netlink_seq_show, | |
2782 | }; | |
1da177e4 LT |
2783 | #endif |
2784 | ||
2785 | int netlink_register_notifier(struct notifier_block *nb) | |
2786 | { | |
efa172f4 | 2787 | return blocking_notifier_chain_register(&netlink_chain, nb); |
1da177e4 | 2788 | } |
6ac552fd | 2789 | EXPORT_SYMBOL(netlink_register_notifier); |
1da177e4 LT |
2790 | |
2791 | int netlink_unregister_notifier(struct notifier_block *nb) | |
2792 | { | |
efa172f4 | 2793 | return blocking_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 | 2794 | } |
6ac552fd | 2795 | EXPORT_SYMBOL(netlink_unregister_notifier); |
746fac4d | 2796 | |
90ddc4f0 | 2797 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
2798 | .family = PF_NETLINK, |
2799 | .owner = THIS_MODULE, | |
2800 | .release = netlink_release, | |
2801 | .bind = netlink_bind, | |
2802 | .connect = netlink_connect, | |
2803 | .socketpair = sock_no_socketpair, | |
2804 | .accept = sock_no_accept, | |
2805 | .getname = netlink_getname, | |
a11e1d43 | 2806 | .poll = datagram_poll, |
025c6818 | 2807 | .ioctl = netlink_ioctl, |
1da177e4 LT |
2808 | .listen = sock_no_listen, |
2809 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
2810 | .setsockopt = netlink_setsockopt, |
2811 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
2812 | .sendmsg = netlink_sendmsg, |
2813 | .recvmsg = netlink_recvmsg, | |
d1b4c689 | 2814 | .mmap = sock_no_mmap, |
1da177e4 LT |
2815 | }; |
2816 | ||
ec1b4cf7 | 2817 | static const struct net_proto_family netlink_family_ops = { |
1da177e4 LT |
2818 | .family = PF_NETLINK, |
2819 | .create = netlink_create, | |
2820 | .owner = THIS_MODULE, /* for consistency 8) */ | |
2821 | }; | |
2822 | ||
4665079c | 2823 | static int __net_init netlink_net_init(struct net *net) |
b4b51029 EB |
2824 | { |
2825 | #ifdef CONFIG_PROC_FS | |
c3506372 CH |
2826 | if (!proc_create_net("netlink", 0, net->proc_net, &netlink_seq_ops, |
2827 | sizeof(struct nl_seq_iter))) | |
b4b51029 EB |
2828 | return -ENOMEM; |
2829 | #endif | |
2830 | return 0; | |
2831 | } | |
2832 | ||
4665079c | 2833 | static void __net_exit netlink_net_exit(struct net *net) |
b4b51029 EB |
2834 | { |
2835 | #ifdef CONFIG_PROC_FS | |
ece31ffd | 2836 | remove_proc_entry("netlink", net->proc_net); |
b4b51029 EB |
2837 | #endif |
2838 | } | |
2839 | ||
b963ea89 DM |
2840 | static void __init netlink_add_usersock_entry(void) |
2841 | { | |
5c398dc8 | 2842 | struct listeners *listeners; |
b963ea89 DM |
2843 | int groups = 32; |
2844 | ||
5c398dc8 | 2845 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
b963ea89 | 2846 | if (!listeners) |
5c398dc8 | 2847 | panic("netlink_add_usersock_entry: Cannot allocate listeners\n"); |
b963ea89 DM |
2848 | |
2849 | netlink_table_grab(); | |
2850 | ||
2851 | nl_table[NETLINK_USERSOCK].groups = groups; | |
5c398dc8 | 2852 | rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners); |
b963ea89 DM |
2853 | nl_table[NETLINK_USERSOCK].module = THIS_MODULE; |
2854 | nl_table[NETLINK_USERSOCK].registered = 1; | |
9785e10a | 2855 | nl_table[NETLINK_USERSOCK].flags = NL_CFG_F_NONROOT_SEND; |
b963ea89 DM |
2856 | |
2857 | netlink_table_ungrab(); | |
2858 | } | |
2859 | ||
022cbae6 | 2860 | static struct pernet_operations __net_initdata netlink_net_ops = { |
b4b51029 EB |
2861 | .init = netlink_net_init, |
2862 | .exit = netlink_net_exit, | |
2863 | }; | |
2864 | ||
49f7b33e | 2865 | static inline u32 netlink_hash(const void *data, u32 len, u32 seed) |
c428ecd1 HX |
2866 | { |
2867 | const struct netlink_sock *nlk = data; | |
2868 | struct netlink_compare_arg arg; | |
2869 | ||
da314c99 | 2870 | netlink_compare_arg_init(&arg, sock_net(&nlk->sk), nlk->portid); |
11b58ba1 | 2871 | return jhash2((u32 *)&arg, netlink_compare_arg_len / sizeof(u32), seed); |
c428ecd1 HX |
2872 | } |
2873 | ||
2874 | static const struct rhashtable_params netlink_rhashtable_params = { | |
2875 | .head_offset = offsetof(struct netlink_sock, node), | |
2876 | .key_len = netlink_compare_arg_len, | |
c428ecd1 HX |
2877 | .obj_hashfn = netlink_hash, |
2878 | .obj_cmpfn = netlink_compare, | |
b5e2c150 | 2879 | .automatic_shrinking = true, |
c428ecd1 HX |
2880 | }; |
2881 | ||
138d0be3 | 2882 | #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) |
951cf368 YS |
2883 | BTF_ID_LIST(btf_netlink_sock_id) |
2884 | BTF_ID(struct, netlink_sock) | |
2885 | ||
14fc6bd6 | 2886 | static const struct bpf_iter_seq_info netlink_seq_info = { |
15172a46 YS |
2887 | .seq_ops = &netlink_seq_ops, |
2888 | .init_seq_private = bpf_iter_init_seq_net, | |
2889 | .fini_seq_private = bpf_iter_fini_seq_net, | |
2890 | .seq_priv_size = sizeof(struct nl_seq_iter), | |
14fc6bd6 YS |
2891 | }; |
2892 | ||
2893 | static struct bpf_iter_reg netlink_reg_info = { | |
2894 | .target = "netlink", | |
3c32cc1b YS |
2895 | .ctx_arg_info_size = 1, |
2896 | .ctx_arg_info = { | |
2897 | { offsetof(struct bpf_iter__netlink, sk), | |
2898 | PTR_TO_BTF_ID_OR_NULL }, | |
2899 | }, | |
14fc6bd6 | 2900 | .seq_info = &netlink_seq_info, |
15172a46 YS |
2901 | }; |
2902 | ||
138d0be3 YS |
2903 | static int __init bpf_iter_register(void) |
2904 | { | |
951cf368 | 2905 | netlink_reg_info.ctx_arg_info[0].btf_id = *btf_netlink_sock_id; |
15172a46 | 2906 | return bpf_iter_reg_target(&netlink_reg_info); |
138d0be3 YS |
2907 | } |
2908 | #endif | |
2909 | ||
1da177e4 LT |
2910 | static int __init netlink_proto_init(void) |
2911 | { | |
1da177e4 | 2912 | int i; |
1da177e4 LT |
2913 | int err = proto_register(&netlink_proto, 0); |
2914 | ||
2915 | if (err != 0) | |
2916 | goto out; | |
2917 | ||
138d0be3 YS |
2918 | #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) |
2919 | err = bpf_iter_register(); | |
2920 | if (err) | |
2921 | goto out; | |
2922 | #endif | |
2923 | ||
c593642c | 2924 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof_field(struct sk_buff, cb)); |
1da177e4 | 2925 | |
0da974f4 | 2926 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
2927 | if (!nl_table) |
2928 | goto panic; | |
1da177e4 | 2929 | |
1da177e4 | 2930 | for (i = 0; i < MAX_LINKS; i++) { |
c428ecd1 HX |
2931 | if (rhashtable_init(&nl_table[i].hash, |
2932 | &netlink_rhashtable_params) < 0) { | |
e341694e TG |
2933 | while (--i > 0) |
2934 | rhashtable_destroy(&nl_table[i].hash); | |
1da177e4 | 2935 | kfree(nl_table); |
fab2caf6 | 2936 | goto panic; |
1da177e4 | 2937 | } |
1da177e4 LT |
2938 | } |
2939 | ||
b963ea89 DM |
2940 | netlink_add_usersock_entry(); |
2941 | ||
1da177e4 | 2942 | sock_register(&netlink_family_ops); |
b4b51029 | 2943 | register_pernet_subsys(&netlink_net_ops); |
25e3f70f | 2944 | register_pernet_subsys(&netlink_tap_net_ops); |
746fac4d | 2945 | /* The netlink device handler may be needed early. */ |
1da177e4 LT |
2946 | rtnetlink_init(); |
2947 | out: | |
2948 | return err; | |
fab2caf6 AM |
2949 | panic: |
2950 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
2951 | } |
2952 | ||
1da177e4 | 2953 | core_initcall(netlink_proto_init); |