1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * NETLINK Kernel-user communication protocol. |
4 | * |
5 | * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk> |
6 | * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> |
7 | * Patrick McHardy <kaber@trash.net> |
8 | * |
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) |
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 |
19 | */ |
20 | |
21 | #include <linux/module.h> |
22 | |
23 | #include <linux/bpf.h> |
24 | #include <linux/capability.h> |
25 | #include <linux/kernel.h> |
26 | #include <linux/filter.h> |
27 | #include <linux/init.h> |
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> |
41 | #include <linux/uaccess.h> |
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> |
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> |
55 | #include <linux/audit.h> |
56 | #include <linux/mutex.h> |
57 | #include <linux/vmalloc.h> |
58 | #include <linux/if_arp.h> |
59 | #include <linux/rhashtable.h> |
60 | #include <asm/cacheflush.h> |
61 | #include <linux/hash.h> |
62 | #include <linux/genetlink.h> |
63 | #include <linux/net_namespace.h> |
64 | #include <linux/nospec.h> |
65 | #include <linux/btf_ids.h> |
66 | |
67 | #include <net/net_namespace.h> |
68 | #include <net/netns/generic.h> |
69 | #include <net/sock.h> |
70 | #include <net/scm.h> |
71 | #include <net/netlink.h> |
72 | #define CREATE_TRACE_POINTS |
73 | #include <trace/events/netlink.h> |
74 | |
75 | #include "af_netlink.h" |
76 | |
77 | struct listeners { |
78 | struct rcu_head rcu; |
79 | unsigned long masks[]; |
80 | }; |
81 | |
82 | /* state bits */ |
83 | #define NETLINK_S_CONGESTED 0x0 |
84 | |
85 | static inline int netlink_is_kernel(struct sock *sk) |
86 | { |
87 | return nlk_test_bit(KERNEL_SOCKET, sk); |
88 | } |
89 | |
90 | struct netlink_table *nl_table __read_mostly; |
91 | EXPORT_SYMBOL_GPL(nl_table); |
92 | |
93 | static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); |
94 | |
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 | |
133 | static int netlink_dump(struct sock *sk, bool lock_taken); |
134 | |
135 | /* nl_table locking explained: |
136 | * Lookup and traversal are protected with an RCU read-side lock. Insertion |
137 | * and removal are protected with per bucket lock while using RCU list |
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. |
142 | */ |
143 | DEFINE_RWLOCK(nl_table_lock); |
144 | EXPORT_SYMBOL_GPL(nl_table_lock); |
145 | static atomic_t nl_table_users = ATOMIC_INIT(0); |
146 | |
147 | #define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock)); |
148 | |
149 | static BLOCKING_NOTIFIER_HEAD(netlink_chain); |
150 | |
151 | |
152 | static const struct rhashtable_params netlink_rhashtable_params; |
153 | |
154 | void do_trace_netlink_extack(const char *msg) |
155 | { |
156 | trace_netlink_extack(msg); |
157 | } |
158 | EXPORT_SYMBOL(do_trace_netlink_extack); |
159 | |
160 | static inline u32 netlink_group_mask(u32 group) |
161 | { |
162 | if (group > 32) |
163 | return 0; |
164 | return group ? 1 << (group - 1) : 0; |
165 | } |
166 | |
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->len; |
171 | struct sk_buff *new; |
172 | |
173 | new = alloc_skb(size: len, priority: 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 | |
181 | skb_put_data(skb: new, data: skb->data, len); |
182 | return new; |
183 | } |
184 | |
185 | static unsigned int netlink_tap_net_id; |
186 | |
187 | struct netlink_tap_net { |
188 | struct list_head netlink_tap_all; |
189 | struct mutex netlink_tap_lock; |
190 | }; |
191 | |
192 | int netlink_add_tap(struct netlink_tap *nt) |
193 | { |
194 | struct net *net = dev_net(dev: nt->dev); |
195 | struct netlink_tap_net *nn = net_generic(net, id: netlink_tap_net_id); |
196 | |
197 | if (unlikely(nt->dev->type != ARPHRD_NETLINK)) |
198 | return -EINVAL; |
199 | |
200 | mutex_lock(&nn->netlink_tap_lock); |
201 | list_add_rcu(new: &nt->list, head: &nn->netlink_tap_all); |
202 | mutex_unlock(lock: &nn->netlink_tap_lock); |
203 | |
204 | __module_get(module: nt->module); |
205 | |
206 | return 0; |
207 | } |
208 | EXPORT_SYMBOL_GPL(netlink_add_tap); |
209 | |
210 | static int __netlink_remove_tap(struct netlink_tap *nt) |
211 | { |
212 | struct net *net = dev_net(dev: nt->dev); |
213 | struct netlink_tap_net *nn = net_generic(net, id: netlink_tap_net_id); |
214 | bool found = false; |
215 | struct netlink_tap *tmp; |
216 | |
217 | mutex_lock(&nn->netlink_tap_lock); |
218 | |
219 | list_for_each_entry(tmp, &nn->netlink_tap_all, list) { |
220 | if (nt == tmp) { |
221 | list_del_rcu(entry: &nt->list); |
222 | found = true; |
223 | goto out; |
224 | } |
225 | } |
226 | |
227 | pr_warn("__netlink_remove_tap: %p not found\n" , nt); |
228 | out: |
229 | mutex_unlock(lock: &nn->netlink_tap_lock); |
230 | |
231 | if (found) |
232 | module_put(module: nt->module); |
233 | |
234 | return found ? 0 : -ENODEV; |
235 | } |
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 | |
248 | static __net_init int netlink_tap_init_net(struct net *net) |
249 | { |
250 | struct netlink_tap_net *nn = net_generic(net, id: netlink_tap_net_id); |
251 | |
252 | INIT_LIST_HEAD(list: &nn->netlink_tap_all); |
253 | mutex_init(&nn->netlink_tap_lock); |
254 | return 0; |
255 | } |
256 | |
257 | static struct pernet_operations netlink_tap_net_ops = { |
258 | .init = netlink_tap_init_net, |
259 | .id = &netlink_tap_net_id, |
260 | .size = sizeof(struct netlink_tap_net), |
261 | }; |
262 | |
263 | static bool netlink_filter_tap(const struct sk_buff *skb) |
264 | { |
265 | struct sock *sk = skb->sk; |
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: |
279 | return true; |
280 | } |
281 | |
282 | return false; |
283 | } |
284 | |
285 | static int __netlink_deliver_tap_skb(struct sk_buff *skb, |
286 | struct net_device *dev) |
287 | { |
288 | struct sk_buff *nskb; |
289 | struct sock *sk = skb->sk; |
290 | int ret = -ENOMEM; |
291 | |
292 | if (!net_eq(net1: dev_net(dev), net2: sock_net(sk))) |
293 | return 0; |
294 | |
295 | dev_hold(dev); |
296 | |
297 | if (is_vmalloc_addr(x: skb->head)) |
298 | nskb = netlink_to_full_skb(skb, GFP_ATOMIC); |
299 | else |
300 | nskb = skb_clone(skb, GFP_ATOMIC); |
301 | if (nskb) { |
302 | nskb->dev = dev; |
303 | nskb->protocol = htons((u16) sk->sk_protocol); |
304 | nskb->pkt_type = netlink_is_kernel(sk) ? |
305 | PACKET_KERNEL : PACKET_USER; |
306 | skb_reset_network_header(skb: nskb); |
307 | ret = dev_queue_xmit(skb: nskb); |
308 | if (unlikely(ret > 0)) |
309 | ret = net_xmit_errno(ret); |
310 | } |
311 | |
312 | dev_put(dev); |
313 | return ret; |
314 | } |
315 | |
316 | static void __netlink_deliver_tap(struct sk_buff *skb, struct netlink_tap_net *nn) |
317 | { |
318 | int ret; |
319 | struct netlink_tap *tmp; |
320 | |
321 | if (!netlink_filter_tap(skb)) |
322 | return; |
323 | |
324 | list_for_each_entry_rcu(tmp, &nn->netlink_tap_all, list) { |
325 | ret = __netlink_deliver_tap_skb(skb, dev: tmp->dev); |
326 | if (unlikely(ret)) |
327 | break; |
328 | } |
329 | } |
330 | |
331 | static void netlink_deliver_tap(struct net *net, struct sk_buff *skb) |
332 | { |
333 | struct netlink_tap_net *nn = net_generic(net, id: netlink_tap_net_id); |
334 | |
335 | rcu_read_lock(); |
336 | |
337 | if (unlikely(!list_empty(&nn->netlink_tap_all))) |
338 | __netlink_deliver_tap(skb, nn); |
339 | |
340 | rcu_read_unlock(); |
341 | } |
342 | |
343 | static void netlink_deliver_tap_kernel(struct sock *dst, struct sock *src, |
344 | struct sk_buff *skb) |
345 | { |
346 | if (!(netlink_is_kernel(sk: dst) && netlink_is_kernel(sk: src))) |
347 | netlink_deliver_tap(net: sock_net(sk: dst), skb); |
348 | } |
349 | |
350 | static void netlink_overrun(struct sock *sk) |
351 | { |
352 | if (!nlk_test_bit(RECV_NO_ENOBUFS, sk)) { |
353 | if (!test_and_set_bit(NETLINK_S_CONGESTED, |
354 | addr: &nlk_sk(sk)->state)) { |
355 | WRITE_ONCE(sk->sk_err, ENOBUFS); |
356 | sk_error_report(sk); |
357 | } |
358 | } |
359 | atomic_inc(v: &sk->sk_drops); |
360 | } |
361 | |
362 | static void netlink_rcv_wake(struct sock *sk) |
363 | { |
364 | struct netlink_sock *nlk = nlk_sk(sk); |
365 | |
366 | if (skb_queue_empty_lockless(list: &sk->sk_receive_queue)) |
367 | clear_bit(NETLINK_S_CONGESTED, addr: &nlk->state); |
368 | if (!test_bit(NETLINK_S_CONGESTED, &nlk->state)) |
369 | wake_up_interruptible(&nlk->wait); |
370 | } |
371 | |
372 | static void netlink_skb_destructor(struct sk_buff *skb) |
373 | { |
374 | if (is_vmalloc_addr(x: skb->head)) { |
375 | if (!skb->cloned || |
376 | !atomic_dec_return(v: &(skb_shinfo(skb)->dataref))) |
377 | vfree_atomic(addr: skb->head); |
378 | |
379 | skb->head = NULL; |
380 | } |
381 | if (skb->sk != NULL) |
382 | sock_rfree(skb); |
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(i: skb->truesize, v: &sk->sk_rmem_alloc); |
391 | sk_mem_charge(sk, size: skb->truesize); |
392 | } |
393 | |
394 | static void netlink_sock_destruct(struct sock *sk) |
395 | { |
396 | struct netlink_sock *nlk = nlk_sk(sk); |
397 | |
398 | if (nlk->cb_running) { |
399 | if (nlk->cb.done) |
400 | nlk->cb.done(&nlk->cb); |
401 | module_put(module: nlk->cb.module); |
402 | kfree_skb(skb: nlk->cb.skb); |
403 | } |
404 | |
405 | skb_queue_purge(list: &sk->sk_receive_queue); |
406 | |
407 | if (!sock_flag(sk, flag: SOCK_DEAD)) { |
408 | printk(KERN_ERR "Freeing alive netlink socket %p\n" , sk); |
409 | return; |
410 | } |
411 | |
412 | WARN_ON(atomic_read(&sk->sk_rmem_alloc)); |
413 | WARN_ON(refcount_read(&sk->sk_wmem_alloc)); |
414 | WARN_ON(nlk_sk(sk)->groups); |
415 | } |
416 | |
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 | |
422 | sk_free(sk: &nlk->sk); |
423 | } |
424 | |
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 |
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 | |
431 | void netlink_table_grab(void) |
432 | __acquires(nl_table_lock) |
433 | { |
434 | might_sleep(); |
435 | |
436 | write_lock_irq(&nl_table_lock); |
437 | |
438 | if (atomic_read(v: &nl_table_users)) { |
439 | DECLARE_WAITQUEUE(wait, current); |
440 | |
441 | add_wait_queue_exclusive(wq_head: &nl_table_wait, wq_entry: &wait); |
442 | for (;;) { |
443 | set_current_state(TASK_UNINTERRUPTIBLE); |
444 | if (atomic_read(v: &nl_table_users) == 0) |
445 | break; |
446 | write_unlock_irq(&nl_table_lock); |
447 | schedule(); |
448 | write_lock_irq(&nl_table_lock); |
449 | } |
450 | |
451 | __set_current_state(TASK_RUNNING); |
452 | remove_wait_queue(wq_head: &nl_table_wait, wq_entry: &wait); |
453 | } |
454 | } |
455 | |
456 | void netlink_table_ungrab(void) |
457 | __releases(nl_table_lock) |
458 | { |
459 | write_unlock_irq(&nl_table_lock); |
460 | wake_up(&nl_table_wait); |
461 | } |
462 | |
463 | static inline void |
464 | netlink_lock_table(void) |
465 | { |
466 | unsigned long flags; |
467 | |
468 | /* read_lock() synchronizes us to netlink_table_grab */ |
469 | |
470 | read_lock_irqsave(&nl_table_lock, flags); |
471 | atomic_inc(v: &nl_table_users); |
472 | read_unlock_irqrestore(&nl_table_lock, flags); |
473 | } |
474 | |
475 | static inline void |
476 | netlink_unlock_table(void) |
477 | { |
478 | if (atomic_dec_and_test(v: &nl_table_users)) |
479 | wake_up(&nl_table_wait); |
480 | } |
481 | |
482 | struct netlink_compare_arg |
483 | { |
484 | possible_net_t pnet; |
485 | u32 portid; |
486 | }; |
487 | |
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)) |
491 | |
492 | static inline int netlink_compare(struct rhashtable_compare_arg *arg, |
493 | const void *ptr) |
494 | { |
495 | const struct netlink_compare_arg *x = arg->key; |
496 | const struct netlink_sock *nlk = ptr; |
497 | |
498 | return nlk->portid != x->portid || |
499 | !net_eq(net1: sock_net(sk: &nlk->sk), net2: read_pnet(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(pnet: &arg->pnet, net); |
507 | arg->portid = portid; |
508 | } |
509 | |
510 | static struct sock *__netlink_lookup(struct netlink_table *table, u32 portid, |
511 | struct net *net) |
512 | { |
513 | struct netlink_compare_arg arg; |
514 | |
515 | netlink_compare_arg_init(arg: &arg, net, portid); |
516 | return rhashtable_lookup_fast(ht: &table->hash, key: &arg, |
517 | params: netlink_rhashtable_params); |
518 | } |
519 | |
520 | static int __netlink_insert(struct netlink_table *table, struct sock *sk) |
521 | { |
522 | struct netlink_compare_arg arg; |
523 | |
524 | netlink_compare_arg_init(arg: &arg, net: sock_net(sk), portid: nlk_sk(sk)->portid); |
525 | return rhashtable_lookup_insert_key(ht: &table->hash, key: &arg, |
526 | obj: &nlk_sk(sk)->node, |
527 | params: netlink_rhashtable_params); |
528 | } |
529 | |
530 | static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid) |
531 | { |
532 | struct netlink_table *table = &nl_table[protocol]; |
533 | struct sock *sk; |
534 | |
535 | rcu_read_lock(); |
536 | sk = __netlink_lookup(table, portid, net); |
537 | if (sk) |
538 | sock_hold(sk); |
539 | rcu_read_unlock(); |
540 | |
541 | return sk; |
542 | } |
543 | |
544 | static const struct proto_ops netlink_ops; |
545 | |
546 | static void |
547 | netlink_update_listeners(struct sock *sk) |
548 | { |
549 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; |
550 | unsigned long mask; |
551 | unsigned int i; |
552 | struct listeners *listeners; |
553 | |
554 | listeners = nl_deref_protected(tbl->listeners); |
555 | if (!listeners) |
556 | return; |
557 | |
558 | for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
559 | mask = 0; |
560 | sk_for_each_bound(sk, &tbl->mc_list) { |
561 | if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) |
562 | mask |= nlk_sk(sk)->groups[i]; |
563 | } |
564 | listeners->masks[i] = mask; |
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 | |
570 | static int netlink_insert(struct sock *sk, u32 portid) |
571 | { |
572 | struct netlink_table *table = &nl_table[sk->sk_protocol]; |
573 | int err; |
574 | |
575 | lock_sock(sk); |
576 | |
577 | err = nlk_sk(sk)->portid == portid ? 0 : -EBUSY; |
578 | if (nlk_sk(sk)->bound) |
579 | goto err; |
580 | |
581 | /* portid can be read locklessly from netlink_getname(). */ |
582 | WRITE_ONCE(nlk_sk(sk)->portid, portid); |
583 | |
584 | sock_hold(sk); |
585 | |
586 | err = __netlink_insert(table, sk); |
587 | if (err) { |
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; |
593 | if (err == -EEXIST) |
594 | err = -EADDRINUSE; |
595 | sock_put(sk); |
596 | goto err; |
597 | } |
598 | |
599 | /* We need to ensure that the socket is hashed and visible. */ |
600 | smp_wmb(); |
601 | /* Paired with lockless reads from netlink_bind(), |
602 | * netlink_connect() and netlink_sendmsg(). |
603 | */ |
604 | WRITE_ONCE(nlk_sk(sk)->bound, portid); |
605 | |
606 | err: |
607 | release_sock(sk); |
608 | return err; |
609 | } |
610 | |
611 | static void netlink_remove(struct sock *sk) |
612 | { |
613 | struct netlink_table *table; |
614 | |
615 | table = &nl_table[sk->sk_protocol]; |
616 | if (!rhashtable_remove_fast(ht: &table->hash, obj: &nlk_sk(sk)->node, |
617 | params: netlink_rhashtable_params)) { |
618 | WARN_ON(refcount_read(&sk->sk_refcnt) == 1); |
619 | __sock_put(sk); |
620 | } |
621 | |
622 | netlink_table_grab(); |
623 | if (nlk_sk(sk)->subscriptions) { |
624 | __sk_del_bind_node(sk); |
625 | netlink_update_listeners(sk); |
626 | } |
627 | if (sk->sk_protocol == NETLINK_GENERIC) |
628 | atomic_inc(v: &genl_sk_destructing_cnt); |
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 | |
638 | static int __netlink_create(struct net *net, struct socket *sock, |
639 | struct mutex *dump_cb_mutex, int protocol, |
640 | int kern) |
641 | { |
642 | struct sock *sk; |
643 | struct netlink_sock *nlk; |
644 | |
645 | sock->ops = &netlink_ops; |
646 | |
647 | sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, prot: &netlink_proto, kern); |
648 | if (!sk) |
649 | return -ENOMEM; |
650 | |
651 | sock_init_data(sock, sk); |
652 | |
653 | nlk = nlk_sk(sk); |
654 | mutex_init(&nlk->nl_cb_mutex); |
655 | lockdep_set_class_and_name(&nlk->nl_cb_mutex, |
656 | nlk_cb_mutex_keys + protocol, |
657 | nlk_cb_mutex_key_strings[protocol]); |
658 | nlk->dump_cb_mutex = dump_cb_mutex; |
659 | init_waitqueue_head(&nlk->wait); |
660 | |
661 | sk->sk_destruct = netlink_sock_destruct; |
662 | sk->sk_protocol = protocol; |
663 | return 0; |
664 | } |
665 | |
666 | static int netlink_create(struct net *net, struct socket *sock, int protocol, |
667 | int kern) |
668 | { |
669 | struct module *module = NULL; |
670 | struct mutex *cb_mutex; |
671 | struct netlink_sock *nlk; |
672 | int (*bind)(struct net *net, int group); |
673 | void (*unbind)(struct net *net, int group); |
674 | void (*release)(struct sock *sock, unsigned long *groups); |
675 | int err = 0; |
676 | |
677 | sock->state = SS_UNCONNECTED; |
678 | |
679 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) |
680 | return -ESOCKTNOSUPPORT; |
681 | |
682 | if (protocol < 0 || protocol >= MAX_LINKS) |
683 | return -EPROTONOSUPPORT; |
684 | protocol = array_index_nospec(protocol, MAX_LINKS); |
685 | |
686 | netlink_lock_table(); |
687 | #ifdef CONFIG_MODULES |
688 | if (!nl_table[protocol].registered) { |
689 | netlink_unlock_table(); |
690 | request_module("net-pf-%d-proto-%d" , PF_NETLINK, protocol); |
691 | netlink_lock_table(); |
692 | } |
693 | #endif |
694 | if (nl_table[protocol].registered && |
695 | try_module_get(module: nl_table[protocol].module)) |
696 | module = nl_table[protocol].module; |
697 | else |
698 | err = -EPROTONOSUPPORT; |
699 | cb_mutex = nl_table[protocol].cb_mutex; |
700 | bind = nl_table[protocol].bind; |
701 | unbind = nl_table[protocol].unbind; |
702 | release = nl_table[protocol].release; |
703 | netlink_unlock_table(); |
704 | |
705 | if (err < 0) |
706 | goto out; |
707 | |
708 | err = __netlink_create(net, sock, dump_cb_mutex: cb_mutex, protocol, kern); |
709 | if (err < 0) |
710 | goto out_module; |
711 | |
712 | sock_prot_inuse_add(net, prot: &netlink_proto, val: 1); |
713 | |
714 | nlk = nlk_sk(sk: sock->sk); |
715 | nlk->module = module; |
716 | nlk->netlink_bind = bind; |
717 | nlk->netlink_unbind = unbind; |
718 | nlk->netlink_release = release; |
719 | out: |
720 | return err; |
721 | |
722 | out_module: |
723 | module_put(module); |
724 | goto out; |
725 | } |
726 | |
727 | static void deferred_put_nlk_sk(struct rcu_head *head) |
728 | { |
729 | struct netlink_sock *nlk = container_of(head, struct netlink_sock, rcu); |
730 | struct sock *sk = &nlk->sk; |
731 | |
732 | kfree(objp: nlk->groups); |
733 | nlk->groups = NULL; |
734 | |
735 | if (!refcount_dec_and_test(r: &sk->sk_refcnt)) |
736 | return; |
737 | |
738 | if (nlk->cb_running && nlk->cb.done) { |
739 | INIT_WORK(&nlk->work, netlink_sock_destruct_work); |
740 | schedule_work(work: &nlk->work); |
741 | return; |
742 | } |
743 | |
744 | sk_free(sk); |
745 | } |
746 | |
747 | static int netlink_release(struct socket *sock) |
748 | { |
749 | struct sock *sk = sock->sk; |
750 | struct netlink_sock *nlk; |
751 | |
752 | if (!sk) |
753 | return 0; |
754 | |
755 | netlink_remove(sk); |
756 | sock_orphan(sk); |
757 | nlk = nlk_sk(sk); |
758 | |
759 | /* |
760 | * OK. Socket is unlinked, any packets that arrive now |
761 | * will be purged. |
762 | */ |
763 | if (nlk->netlink_release) |
764 | nlk->netlink_release(sk, nlk->groups); |
765 | |
766 | /* must not acquire netlink_table_lock in any way again before unbind |
767 | * and notifying genetlink is done as otherwise it might deadlock |
768 | */ |
769 | if (nlk->netlink_unbind) { |
770 | int i; |
771 | |
772 | for (i = 0; i < nlk->ngroups; i++) |
773 | if (test_bit(i, nlk->groups)) |
774 | nlk->netlink_unbind(sock_net(sk), i + 1); |
775 | } |
776 | if (sk->sk_protocol == NETLINK_GENERIC && |
777 | atomic_dec_return(v: &genl_sk_destructing_cnt) == 0) |
778 | wake_up(&genl_sk_destructing_waitq); |
779 | |
780 | sock->sk = NULL; |
781 | wake_up_interruptible_all(&nlk->wait); |
782 | |
783 | skb_queue_purge(list: &sk->sk_write_queue); |
784 | |
785 | if (nlk->portid && nlk->bound) { |
786 | struct netlink_notify n = { |
787 | .net = sock_net(sk), |
788 | .protocol = sk->sk_protocol, |
789 | .portid = nlk->portid, |
790 | }; |
791 | blocking_notifier_call_chain(nh: &netlink_chain, |
792 | NETLINK_URELEASE, v: &n); |
793 | } |
794 | |
795 | module_put(module: nlk->module); |
796 | |
797 | if (netlink_is_kernel(sk)) { |
798 | netlink_table_grab(); |
799 | BUG_ON(nl_table[sk->sk_protocol].registered == 0); |
800 | if (--nl_table[sk->sk_protocol].registered == 0) { |
801 | struct listeners *old; |
802 | |
803 | old = nl_deref_protected(nl_table[sk->sk_protocol].listeners); |
804 | RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL); |
805 | kfree_rcu(old, rcu); |
806 | nl_table[sk->sk_protocol].module = NULL; |
807 | nl_table[sk->sk_protocol].bind = NULL; |
808 | nl_table[sk->sk_protocol].unbind = NULL; |
809 | nl_table[sk->sk_protocol].flags = 0; |
810 | nl_table[sk->sk_protocol].registered = 0; |
811 | } |
812 | netlink_table_ungrab(); |
813 | } |
814 | |
815 | sock_prot_inuse_add(net: sock_net(sk), prot: &netlink_proto, val: -1); |
816 | |
817 | /* Because struct net might disappear soon, do not keep a pointer. */ |
818 | if (!sk->sk_net_refcnt && sock_net(sk) != &init_net) { |
819 | __netns_tracker_free(net: sock_net(sk), tracker: &sk->ns_tracker, refcounted: false); |
820 | /* Because of deferred_put_nlk_sk and use of work queue, |
821 | * it is possible netns will be freed before this socket. |
822 | */ |
823 | sock_net_set(sk, net: &init_net); |
824 | __netns_tracker_alloc(net: &init_net, tracker: &sk->ns_tracker, |
825 | refcounted: false, GFP_KERNEL); |
826 | } |
827 | call_rcu(head: &nlk->rcu, func: deferred_put_nlk_sk); |
828 | return 0; |
829 | } |
830 | |
831 | static int netlink_autobind(struct socket *sock) |
832 | { |
833 | struct sock *sk = sock->sk; |
834 | struct net *net = sock_net(sk); |
835 | struct netlink_table *table = &nl_table[sk->sk_protocol]; |
836 | s32 portid = task_tgid_vnr(current); |
837 | int err; |
838 | s32 rover = -4096; |
839 | bool ok; |
840 | |
841 | retry: |
842 | cond_resched(); |
843 | rcu_read_lock(); |
844 | ok = !__netlink_lookup(table, portid, net); |
845 | rcu_read_unlock(); |
846 | if (!ok) { |
847 | /* Bind collision, search negative portid values. */ |
848 | if (rover == -4096) |
849 | /* rover will be in range [S32_MIN, -4097] */ |
850 | rover = S32_MIN + get_random_u32_below(ceil: -4096 - S32_MIN); |
851 | else if (rover >= -4096) |
852 | rover = -4097; |
853 | portid = rover--; |
854 | goto retry; |
855 | } |
856 | |
857 | err = netlink_insert(sk, portid); |
858 | if (err == -EADDRINUSE) |
859 | goto retry; |
860 | |
861 | /* If 2 threads race to autobind, that is fine. */ |
862 | if (err == -EBUSY) |
863 | err = 0; |
864 | |
865 | return err; |
866 | } |
867 | |
868 | /** |
869 | * __netlink_ns_capable - General netlink message capability test |
870 | * @nsp: NETLINK_CB of the socket buffer holding a netlink command from userspace. |
871 | * @user_ns: The user namespace of the capability to use |
872 | * @cap: The capability to use |
873 | * |
874 | * Test to see if the opener of the socket we received the message |
875 | * from had when the netlink socket was created and the sender of the |
876 | * message has the capability @cap in the user namespace @user_ns. |
877 | */ |
878 | bool __netlink_ns_capable(const struct netlink_skb_parms *nsp, |
879 | struct user_namespace *user_ns, int cap) |
880 | { |
881 | return ((nsp->flags & NETLINK_SKB_DST) || |
882 | file_ns_capable(file: nsp->sk->sk_socket->file, ns: user_ns, cap)) && |
883 | ns_capable(ns: user_ns, cap); |
884 | } |
885 | EXPORT_SYMBOL(__netlink_ns_capable); |
886 | |
887 | /** |
888 | * netlink_ns_capable - General netlink message capability test |
889 | * @skb: socket buffer holding a netlink command from userspace |
890 | * @user_ns: The user namespace of the capability to use |
891 | * @cap: The capability to use |
892 | * |
893 | * Test to see if the opener of the socket we received the message |
894 | * from had when the netlink socket was created and the sender of the |
895 | * message has the capability @cap in the user namespace @user_ns. |
896 | */ |
897 | bool netlink_ns_capable(const struct sk_buff *skb, |
898 | struct user_namespace *user_ns, int cap) |
899 | { |
900 | return __netlink_ns_capable(&NETLINK_CB(skb), user_ns, cap); |
901 | } |
902 | EXPORT_SYMBOL(netlink_ns_capable); |
903 | |
904 | /** |
905 | * netlink_capable - Netlink global message capability test |
906 | * @skb: socket buffer holding a netlink command from userspace |
907 | * @cap: The capability to use |
908 | * |
909 | * Test to see if the opener of the socket we received the message |
910 | * from had when the netlink socket was created and the sender of the |
911 | * message has the capability @cap in all user namespaces. |
912 | */ |
913 | bool netlink_capable(const struct sk_buff *skb, int cap) |
914 | { |
915 | return netlink_ns_capable(skb, &init_user_ns, cap); |
916 | } |
917 | EXPORT_SYMBOL(netlink_capable); |
918 | |
919 | /** |
920 | * netlink_net_capable - Netlink network namespace message capability test |
921 | * @skb: socket buffer holding a netlink command from userspace |
922 | * @cap: The capability to use |
923 | * |
924 | * Test to see if the opener of the socket we received the message |
925 | * from had when the netlink socket was created and the sender of the |
926 | * message has the capability @cap over the network namespace of |
927 | * the socket we received the message from. |
928 | */ |
929 | bool netlink_net_capable(const struct sk_buff *skb, int cap) |
930 | { |
931 | return netlink_ns_capable(skb, sock_net(sk: skb->sk)->user_ns, cap); |
932 | } |
933 | EXPORT_SYMBOL(netlink_net_capable); |
934 | |
935 | static inline int netlink_allowed(const struct socket *sock, unsigned int flag) |
936 | { |
937 | return (nl_table[sock->sk->sk_protocol].flags & flag) || |
938 | ns_capable(ns: sock_net(sk: sock->sk)->user_ns, CAP_NET_ADMIN); |
939 | } |
940 | |
941 | static void |
942 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) |
943 | { |
944 | struct netlink_sock *nlk = nlk_sk(sk); |
945 | |
946 | if (nlk->subscriptions && !subscriptions) |
947 | __sk_del_bind_node(sk); |
948 | else if (!nlk->subscriptions && subscriptions) |
949 | sk_add_bind_node(sk, list: &nl_table[sk->sk_protocol].mc_list); |
950 | nlk->subscriptions = subscriptions; |
951 | } |
952 | |
953 | static int netlink_realloc_groups(struct sock *sk) |
954 | { |
955 | struct netlink_sock *nlk = nlk_sk(sk); |
956 | unsigned int groups; |
957 | unsigned long *new_groups; |
958 | int err = 0; |
959 | |
960 | netlink_table_grab(); |
961 | |
962 | groups = nl_table[sk->sk_protocol].groups; |
963 | if (!nl_table[sk->sk_protocol].registered) { |
964 | err = -ENOENT; |
965 | goto out_unlock; |
966 | } |
967 | |
968 | if (nlk->ngroups >= groups) |
969 | goto out_unlock; |
970 | |
971 | new_groups = krealloc(objp: nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
972 | if (new_groups == NULL) { |
973 | err = -ENOMEM; |
974 | goto out_unlock; |
975 | } |
976 | memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, |
977 | NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); |
978 | |
979 | nlk->groups = new_groups; |
980 | nlk->ngroups = groups; |
981 | out_unlock: |
982 | netlink_table_ungrab(); |
983 | return err; |
984 | } |
985 | |
986 | static void netlink_undo_bind(int group, long unsigned int groups, |
987 | struct sock *sk) |
988 | { |
989 | struct netlink_sock *nlk = nlk_sk(sk); |
990 | int undo; |
991 | |
992 | if (!nlk->netlink_unbind) |
993 | return; |
994 | |
995 | for (undo = 0; undo < group; undo++) |
996 | if (test_bit(undo, &groups)) |
997 | nlk->netlink_unbind(sock_net(sk), undo + 1); |
998 | } |
999 | |
1000 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, |
1001 | int addr_len) |
1002 | { |
1003 | struct sock *sk = sock->sk; |
1004 | struct net *net = sock_net(sk); |
1005 | struct netlink_sock *nlk = nlk_sk(sk); |
1006 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
1007 | int err = 0; |
1008 | unsigned long groups; |
1009 | bool bound; |
1010 | |
1011 | if (addr_len < sizeof(struct sockaddr_nl)) |
1012 | return -EINVAL; |
1013 | |
1014 | if (nladdr->nl_family != AF_NETLINK) |
1015 | return -EINVAL; |
1016 | groups = nladdr->nl_groups; |
1017 | |
1018 | /* Only superuser is allowed to listen multicasts */ |
1019 | if (groups) { |
1020 | if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV)) |
1021 | return -EPERM; |
1022 | err = netlink_realloc_groups(sk); |
1023 | if (err) |
1024 | return err; |
1025 | } |
1026 | |
1027 | if (nlk->ngroups < BITS_PER_LONG) |
1028 | groups &= (1UL << nlk->ngroups) - 1; |
1029 | |
1030 | /* Paired with WRITE_ONCE() in netlink_insert() */ |
1031 | bound = READ_ONCE(nlk->bound); |
1032 | if (bound) { |
1033 | /* Ensure nlk->portid is up-to-date. */ |
1034 | smp_rmb(); |
1035 | |
1036 | if (nladdr->nl_pid != nlk->portid) |
1037 | return -EINVAL; |
1038 | } |
1039 | |
1040 | if (nlk->netlink_bind && groups) { |
1041 | int group; |
1042 | |
1043 | /* nl_groups is a u32, so cap the maximum groups we can bind */ |
1044 | for (group = 0; group < BITS_PER_TYPE(u32); group++) { |
1045 | if (!test_bit(group, &groups)) |
1046 | continue; |
1047 | err = nlk->netlink_bind(net, group + 1); |
1048 | if (!err) |
1049 | continue; |
1050 | netlink_undo_bind(group, groups, sk); |
1051 | return err; |
1052 | } |
1053 | } |
1054 | |
1055 | /* No need for barriers here as we return to user-space without |
1056 | * using any of the bound attributes. |
1057 | */ |
1058 | netlink_lock_table(); |
1059 | if (!bound) { |
1060 | err = nladdr->nl_pid ? |
1061 | netlink_insert(sk, portid: nladdr->nl_pid) : |
1062 | netlink_autobind(sock); |
1063 | if (err) { |
1064 | netlink_undo_bind(BITS_PER_TYPE(u32), groups, sk); |
1065 | goto unlock; |
1066 | } |
1067 | } |
1068 | |
1069 | if (!groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
1070 | goto unlock; |
1071 | netlink_unlock_table(); |
1072 | |
1073 | netlink_table_grab(); |
1074 | netlink_update_subscriptions(sk, subscriptions: nlk->subscriptions + |
1075 | hweight32(groups) - |
1076 | hweight32(nlk->groups[0])); |
1077 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | groups; |
1078 | netlink_update_listeners(sk); |
1079 | netlink_table_ungrab(); |
1080 | |
1081 | return 0; |
1082 | |
1083 | unlock: |
1084 | netlink_unlock_table(); |
1085 | return err; |
1086 | } |
1087 | |
1088 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, |
1089 | int alen, int flags) |
1090 | { |
1091 | int err = 0; |
1092 | struct sock *sk = sock->sk; |
1093 | struct netlink_sock *nlk = nlk_sk(sk); |
1094 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
1095 | |
1096 | if (alen < sizeof(addr->sa_family)) |
1097 | return -EINVAL; |
1098 | |
1099 | if (addr->sa_family == AF_UNSPEC) { |
1100 | /* paired with READ_ONCE() in netlink_getsockbyportid() */ |
1101 | WRITE_ONCE(sk->sk_state, NETLINK_UNCONNECTED); |
1102 | /* dst_portid and dst_group can be read locklessly */ |
1103 | WRITE_ONCE(nlk->dst_portid, 0); |
1104 | WRITE_ONCE(nlk->dst_group, 0); |
1105 | return 0; |
1106 | } |
1107 | if (addr->sa_family != AF_NETLINK) |
1108 | return -EINVAL; |
1109 | |
1110 | if (alen < sizeof(struct sockaddr_nl)) |
1111 | return -EINVAL; |
1112 | |
1113 | if ((nladdr->nl_groups || nladdr->nl_pid) && |
1114 | !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND)) |
1115 | return -EPERM; |
1116 | |
1117 | /* No need for barriers here as we return to user-space without |
1118 | * using any of the bound attributes. |
1119 | * Paired with WRITE_ONCE() in netlink_insert(). |
1120 | */ |
1121 | if (!READ_ONCE(nlk->bound)) |
1122 | err = netlink_autobind(sock); |
1123 | |
1124 | if (err == 0) { |
1125 | /* paired with READ_ONCE() in netlink_getsockbyportid() */ |
1126 | WRITE_ONCE(sk->sk_state, NETLINK_CONNECTED); |
1127 | /* dst_portid and dst_group can be read locklessly */ |
1128 | WRITE_ONCE(nlk->dst_portid, nladdr->nl_pid); |
1129 | WRITE_ONCE(nlk->dst_group, ffs(nladdr->nl_groups)); |
1130 | } |
1131 | |
1132 | return err; |
1133 | } |
1134 | |
1135 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, |
1136 | int peer) |
1137 | { |
1138 | struct sock *sk = sock->sk; |
1139 | struct netlink_sock *nlk = nlk_sk(sk); |
1140 | DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr); |
1141 | |
1142 | nladdr->nl_family = AF_NETLINK; |
1143 | nladdr->nl_pad = 0; |
1144 | |
1145 | if (peer) { |
1146 | /* Paired with WRITE_ONCE() in netlink_connect() */ |
1147 | nladdr->nl_pid = READ_ONCE(nlk->dst_portid); |
1148 | nladdr->nl_groups = netlink_group_mask(READ_ONCE(nlk->dst_group)); |
1149 | } else { |
1150 | /* Paired with WRITE_ONCE() in netlink_insert() */ |
1151 | nladdr->nl_pid = READ_ONCE(nlk->portid); |
1152 | netlink_lock_table(); |
1153 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
1154 | netlink_unlock_table(); |
1155 | } |
1156 | return sizeof(*nladdr); |
1157 | } |
1158 | |
1159 | static int netlink_ioctl(struct socket *sock, unsigned int cmd, |
1160 | unsigned long arg) |
1161 | { |
1162 | /* try to hand this ioctl down to the NIC drivers. |
1163 | */ |
1164 | return -ENOIOCTLCMD; |
1165 | } |
1166 | |
1167 | static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid) |
1168 | { |
1169 | struct sock *sock; |
1170 | struct netlink_sock *nlk; |
1171 | |
1172 | sock = netlink_lookup(net: sock_net(sk: ssk), protocol: ssk->sk_protocol, portid); |
1173 | if (!sock) |
1174 | return ERR_PTR(error: -ECONNREFUSED); |
1175 | |
1176 | /* Don't bother queuing skb if kernel socket has no input function */ |
1177 | nlk = nlk_sk(sk: sock); |
1178 | /* dst_portid and sk_state can be changed in netlink_connect() */ |
1179 | if (READ_ONCE(sock->sk_state) == NETLINK_CONNECTED && |
1180 | READ_ONCE(nlk->dst_portid) != nlk_sk(sk: ssk)->portid) { |
1181 | sock_put(sk: sock); |
1182 | return ERR_PTR(error: -ECONNREFUSED); |
1183 | } |
1184 | return sock; |
1185 | } |
1186 | |
1187 | struct sock *netlink_getsockbyfilp(struct file *filp) |
1188 | { |
1189 | struct inode *inode = file_inode(f: filp); |
1190 | struct sock *sock; |
1191 | |
1192 | if (!S_ISSOCK(inode->i_mode)) |
1193 | return ERR_PTR(error: -ENOTSOCK); |
1194 | |
1195 | sock = SOCKET_I(inode)->sk; |
1196 | if (sock->sk_family != AF_NETLINK) |
1197 | return ERR_PTR(error: -EINVAL); |
1198 | |
1199 | sock_hold(sk: sock); |
1200 | return sock; |
1201 | } |
1202 | |
1203 | struct sk_buff *netlink_alloc_large_skb(unsigned int size, int broadcast) |
1204 | { |
1205 | size_t head_size = SKB_HEAD_ALIGN(size); |
1206 | struct sk_buff *skb; |
1207 | void *data; |
1208 | |
1209 | if (head_size <= PAGE_SIZE || broadcast) |
1210 | return alloc_skb(size, GFP_KERNEL); |
1211 | |
1212 | data = kvmalloc(size: head_size, GFP_KERNEL); |
1213 | if (!data) |
1214 | return NULL; |
1215 | |
1216 | skb = __build_skb(data, frag_size: head_size); |
1217 | if (!skb) |
1218 | kvfree(addr: data); |
1219 | else if (is_vmalloc_addr(x: data)) |
1220 | skb->destructor = netlink_skb_destructor; |
1221 | |
1222 | return skb; |
1223 | } |
1224 | |
1225 | /* |
1226 | * Attach a skb to a netlink socket. |
1227 | * The caller must hold a reference to the destination socket. On error, the |
1228 | * reference is dropped. The skb is not send to the destination, just all |
1229 | * all error checks are performed and memory in the queue is reserved. |
1230 | * Return values: |
1231 | * < 0: error. skb freed, reference to sock dropped. |
1232 | * 0: continue |
1233 | * 1: repeat lookup - reference dropped while waiting for socket memory. |
1234 | */ |
1235 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
1236 | long *timeo, struct sock *ssk) |
1237 | { |
1238 | struct netlink_sock *nlk; |
1239 | |
1240 | nlk = nlk_sk(sk); |
1241 | |
1242 | if ((atomic_read(v: &sk->sk_rmem_alloc) > sk->sk_rcvbuf || |
1243 | test_bit(NETLINK_S_CONGESTED, &nlk->state))) { |
1244 | DECLARE_WAITQUEUE(wait, current); |
1245 | if (!*timeo) { |
1246 | if (!ssk || netlink_is_kernel(sk: ssk)) |
1247 | netlink_overrun(sk); |
1248 | sock_put(sk); |
1249 | kfree_skb(skb); |
1250 | return -EAGAIN; |
1251 | } |
1252 | |
1253 | __set_current_state(TASK_INTERRUPTIBLE); |
1254 | add_wait_queue(wq_head: &nlk->wait, wq_entry: &wait); |
1255 | |
1256 | if ((atomic_read(v: &sk->sk_rmem_alloc) > sk->sk_rcvbuf || |
1257 | test_bit(NETLINK_S_CONGESTED, &nlk->state)) && |
1258 | !sock_flag(sk, flag: SOCK_DEAD)) |
1259 | *timeo = schedule_timeout(timeout: *timeo); |
1260 | |
1261 | __set_current_state(TASK_RUNNING); |
1262 | remove_wait_queue(wq_head: &nlk->wait, wq_entry: &wait); |
1263 | sock_put(sk); |
1264 | |
1265 | if (signal_pending(current)) { |
1266 | kfree_skb(skb); |
1267 | return sock_intr_errno(timeo: *timeo); |
1268 | } |
1269 | return 1; |
1270 | } |
1271 | netlink_skb_set_owner_r(skb, sk); |
1272 | return 0; |
1273 | } |
1274 | |
1275 | static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
1276 | { |
1277 | int len = skb->len; |
1278 | |
1279 | netlink_deliver_tap(net: sock_net(sk), skb); |
1280 | |
1281 | skb_queue_tail(list: &sk->sk_receive_queue, newsk: skb); |
1282 | sk->sk_data_ready(sk); |
1283 | return len; |
1284 | } |
1285 | |
1286 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
1287 | { |
1288 | int len = __netlink_sendskb(sk, skb); |
1289 | |
1290 | sock_put(sk); |
1291 | return len; |
1292 | } |
1293 | |
1294 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) |
1295 | { |
1296 | kfree_skb(skb); |
1297 | sock_put(sk); |
1298 | } |
1299 | |
1300 | static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation) |
1301 | { |
1302 | int delta; |
1303 | |
1304 | WARN_ON(skb->sk != NULL); |
1305 | delta = skb->end - skb->tail; |
1306 | if (is_vmalloc_addr(x: skb->head) || delta * 2 < skb->truesize) |
1307 | return skb; |
1308 | |
1309 | if (skb_shared(skb)) { |
1310 | struct sk_buff *nskb = skb_clone(skb, priority: allocation); |
1311 | if (!nskb) |
1312 | return skb; |
1313 | consume_skb(skb); |
1314 | skb = nskb; |
1315 | } |
1316 | |
1317 | pskb_expand_head(skb, nhead: 0, ntail: -delta, |
1318 | gfp_mask: (allocation & ~__GFP_DIRECT_RECLAIM) | |
1319 | __GFP_NOWARN | __GFP_NORETRY); |
1320 | return skb; |
1321 | } |
1322 | |
1323 | static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb, |
1324 | struct sock *ssk) |
1325 | { |
1326 | int ret; |
1327 | struct netlink_sock *nlk = nlk_sk(sk); |
1328 | |
1329 | ret = -ECONNREFUSED; |
1330 | if (nlk->netlink_rcv != NULL) { |
1331 | ret = skb->len; |
1332 | netlink_skb_set_owner_r(skb, sk); |
1333 | NETLINK_CB(skb).sk = ssk; |
1334 | netlink_deliver_tap_kernel(dst: sk, src: ssk, skb); |
1335 | nlk->netlink_rcv(skb); |
1336 | consume_skb(skb); |
1337 | } else { |
1338 | kfree_skb(skb); |
1339 | } |
1340 | sock_put(sk); |
1341 | return ret; |
1342 | } |
1343 | |
1344 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, |
1345 | u32 portid, int nonblock) |
1346 | { |
1347 | struct sock *sk; |
1348 | int err; |
1349 | long timeo; |
1350 | |
1351 | skb = netlink_trim(skb, allocation: gfp_any()); |
1352 | |
1353 | timeo = sock_sndtimeo(sk: ssk, noblock: nonblock); |
1354 | retry: |
1355 | sk = netlink_getsockbyportid(ssk, portid); |
1356 | if (IS_ERR(ptr: sk)) { |
1357 | kfree_skb(skb); |
1358 | return PTR_ERR(ptr: sk); |
1359 | } |
1360 | if (netlink_is_kernel(sk)) |
1361 | return netlink_unicast_kernel(sk, skb, ssk); |
1362 | |
1363 | if (sk_filter(sk, skb)) { |
1364 | err = skb->len; |
1365 | kfree_skb(skb); |
1366 | sock_put(sk); |
1367 | return err; |
1368 | } |
1369 | |
1370 | err = netlink_attachskb(sk, skb, timeo: &timeo, ssk); |
1371 | if (err == 1) |
1372 | goto retry; |
1373 | if (err) |
1374 | return err; |
1375 | |
1376 | return netlink_sendskb(sk, skb); |
1377 | } |
1378 | EXPORT_SYMBOL(netlink_unicast); |
1379 | |
1380 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
1381 | { |
1382 | int res = 0; |
1383 | struct listeners *listeners; |
1384 | |
1385 | BUG_ON(!netlink_is_kernel(sk)); |
1386 | |
1387 | rcu_read_lock(); |
1388 | listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); |
1389 | |
1390 | if (listeners && group - 1 < nl_table[sk->sk_protocol].groups) |
1391 | res = test_bit(group - 1, listeners->masks); |
1392 | |
1393 | rcu_read_unlock(); |
1394 | |
1395 | return res; |
1396 | } |
1397 | EXPORT_SYMBOL_GPL(netlink_has_listeners); |
1398 | |
1399 | bool netlink_strict_get_check(struct sk_buff *skb) |
1400 | { |
1401 | return nlk_test_bit(STRICT_CHK, NETLINK_CB(skb).sk); |
1402 | } |
1403 | EXPORT_SYMBOL_GPL(netlink_strict_get_check); |
1404 | |
1405 | static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) |
1406 | { |
1407 | struct netlink_sock *nlk = nlk_sk(sk); |
1408 | |
1409 | if (atomic_read(v: &sk->sk_rmem_alloc) <= sk->sk_rcvbuf && |
1410 | !test_bit(NETLINK_S_CONGESTED, &nlk->state)) { |
1411 | netlink_skb_set_owner_r(skb, sk); |
1412 | __netlink_sendskb(sk, skb); |
1413 | return atomic_read(v: &sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1); |
1414 | } |
1415 | return -1; |
1416 | } |
1417 | |
1418 | struct netlink_broadcast_data { |
1419 | struct sock *exclude_sk; |
1420 | struct net *net; |
1421 | u32 portid; |
1422 | u32 group; |
1423 | int failure; |
1424 | int delivery_failure; |
1425 | int congested; |
1426 | int delivered; |
1427 | gfp_t allocation; |
1428 | struct sk_buff *skb, *skb2; |
1429 | int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data); |
1430 | void *tx_data; |
1431 | }; |
1432 | |
1433 | static void do_one_broadcast(struct sock *sk, |
1434 | struct netlink_broadcast_data *p) |
1435 | { |
1436 | struct netlink_sock *nlk = nlk_sk(sk); |
1437 | int val; |
1438 | |
1439 | if (p->exclude_sk == sk) |
1440 | return; |
1441 | |
1442 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
1443 | !test_bit(p->group - 1, nlk->groups)) |
1444 | return; |
1445 | |
1446 | if (!net_eq(net1: sock_net(sk), net2: p->net)) { |
1447 | if (!nlk_test_bit(LISTEN_ALL_NSID, sk)) |
1448 | return; |
1449 | |
1450 | if (!peernet_has_id(net: sock_net(sk), peer: p->net)) |
1451 | return; |
1452 | |
1453 | if (!file_ns_capable(file: sk->sk_socket->file, ns: p->net->user_ns, |
1454 | CAP_NET_BROADCAST)) |
1455 | return; |
1456 | } |
1457 | |
1458 | if (p->failure) { |
1459 | netlink_overrun(sk); |
1460 | return; |
1461 | } |
1462 | |
1463 | sock_hold(sk); |
1464 | if (p->skb2 == NULL) { |
1465 | if (skb_shared(skb: p->skb)) { |
1466 | p->skb2 = skb_clone(skb: p->skb, priority: p->allocation); |
1467 | } else { |
1468 | p->skb2 = skb_get(skb: p->skb); |
1469 | /* |
1470 | * skb ownership may have been set when |
1471 | * delivered to a previous socket. |
1472 | */ |
1473 | skb_orphan(skb: p->skb2); |
1474 | } |
1475 | } |
1476 | if (p->skb2 == NULL) { |
1477 | netlink_overrun(sk); |
1478 | /* Clone failed. Notify ALL listeners. */ |
1479 | p->failure = 1; |
1480 | if (nlk_test_bit(BROADCAST_SEND_ERROR, sk)) |
1481 | p->delivery_failure = 1; |
1482 | goto out; |
1483 | } |
1484 | |
1485 | if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) { |
1486 | kfree_skb(skb: p->skb2); |
1487 | p->skb2 = NULL; |
1488 | goto out; |
1489 | } |
1490 | |
1491 | if (sk_filter(sk, skb: p->skb2)) { |
1492 | kfree_skb(skb: p->skb2); |
1493 | p->skb2 = NULL; |
1494 | goto out; |
1495 | } |
1496 | NETLINK_CB(p->skb2).nsid = peernet2id(net: sock_net(sk), peer: p->net); |
1497 | if (NETLINK_CB(p->skb2).nsid != NETNSA_NSID_NOT_ASSIGNED) |
1498 | NETLINK_CB(p->skb2).nsid_is_set = true; |
1499 | val = netlink_broadcast_deliver(sk, skb: p->skb2); |
1500 | if (val < 0) { |
1501 | netlink_overrun(sk); |
1502 | if (nlk_test_bit(BROADCAST_SEND_ERROR, sk)) |
1503 | p->delivery_failure = 1; |
1504 | } else { |
1505 | p->congested |= val; |
1506 | p->delivered = 1; |
1507 | p->skb2 = NULL; |
1508 | } |
1509 | out: |
1510 | sock_put(sk); |
1511 | } |
1512 | |
1513 | int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, |
1514 | u32 portid, |
1515 | u32 group, gfp_t allocation, |
1516 | netlink_filter_fn filter, |
1517 | void *filter_data) |
1518 | { |
1519 | struct net *net = sock_net(sk: ssk); |
1520 | struct netlink_broadcast_data info; |
1521 | struct sock *sk; |
1522 | |
1523 | skb = netlink_trim(skb, allocation); |
1524 | |
1525 | info.exclude_sk = ssk; |
1526 | info.net = net; |
1527 | info.portid = portid; |
1528 | info.group = group; |
1529 | info.failure = 0; |
1530 | info.delivery_failure = 0; |
1531 | info.congested = 0; |
1532 | info.delivered = 0; |
1533 | info.allocation = allocation; |
1534 | info.skb = skb; |
1535 | info.skb2 = NULL; |
1536 | info.tx_filter = filter; |
1537 | info.tx_data = filter_data; |
1538 | |
1539 | /* While we sleep in clone, do not allow to change socket list */ |
1540 | |
1541 | netlink_lock_table(); |
1542 | |
1543 | sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
1544 | do_one_broadcast(sk, p: &info); |
1545 | |
1546 | consume_skb(skb); |
1547 | |
1548 | netlink_unlock_table(); |
1549 | |
1550 | if (info.delivery_failure) { |
1551 | kfree_skb(skb: info.skb2); |
1552 | return -ENOBUFS; |
1553 | } |
1554 | consume_skb(skb: info.skb2); |
1555 | |
1556 | if (info.delivered) { |
1557 | if (info.congested && gfpflags_allow_blocking(gfp_flags: allocation)) |
1558 | yield(); |
1559 | return 0; |
1560 | } |
1561 | return -ESRCH; |
1562 | } |
1563 | EXPORT_SYMBOL(netlink_broadcast_filtered); |
1564 | |
1565 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 portid, |
1566 | u32 group, gfp_t allocation) |
1567 | { |
1568 | return netlink_broadcast_filtered(ssk, skb, portid, group, allocation, |
1569 | NULL, NULL); |
1570 | } |
1571 | EXPORT_SYMBOL(netlink_broadcast); |
1572 | |
1573 | struct netlink_set_err_data { |
1574 | struct sock *exclude_sk; |
1575 | u32 portid; |
1576 | u32 group; |
1577 | int code; |
1578 | }; |
1579 | |
1580 | static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p) |
1581 | { |
1582 | struct netlink_sock *nlk = nlk_sk(sk); |
1583 | int ret = 0; |
1584 | |
1585 | if (sk == p->exclude_sk) |
1586 | goto out; |
1587 | |
1588 | if (!net_eq(net1: sock_net(sk), net2: sock_net(sk: p->exclude_sk))) |
1589 | goto out; |
1590 | |
1591 | if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || |
1592 | !test_bit(p->group - 1, nlk->groups)) |
1593 | goto out; |
1594 | |
1595 | if (p->code == ENOBUFS && nlk_test_bit(RECV_NO_ENOBUFS, sk)) { |
1596 | ret = 1; |
1597 | goto out; |
1598 | } |
1599 | |
1600 | WRITE_ONCE(sk->sk_err, p->code); |
1601 | sk_error_report(sk); |
1602 | out: |
1603 | return ret; |
1604 | } |
1605 | |
1606 | /** |
1607 | * netlink_set_err - report error to broadcast listeners |
1608 | * @ssk: the kernel netlink socket, as returned by netlink_kernel_create() |
1609 | * @portid: the PORTID of a process that we want to skip (if any) |
1610 | * @group: the broadcast group that will notice the error |
1611 | * @code: error code, must be negative (as usual in kernelspace) |
1612 | * |
1613 | * This function returns the number of broadcast listeners that have set the |
1614 | * NETLINK_NO_ENOBUFS socket option. |
1615 | */ |
1616 | int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code) |
1617 | { |
1618 | struct netlink_set_err_data info; |
1619 | unsigned long flags; |
1620 | struct sock *sk; |
1621 | int ret = 0; |
1622 | |
1623 | info.exclude_sk = ssk; |
1624 | info.portid = portid; |
1625 | info.group = group; |
1626 | /* sk->sk_err wants a positive error value */ |
1627 | info.code = -code; |
1628 | |
1629 | read_lock_irqsave(&nl_table_lock, flags); |
1630 | |
1631 | sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) |
1632 | ret += do_one_set_err(sk, p: &info); |
1633 | |
1634 | read_unlock_irqrestore(&nl_table_lock, flags); |
1635 | return ret; |
1636 | } |
1637 | EXPORT_SYMBOL(netlink_set_err); |
1638 | |
1639 | /* must be called with netlink table grabbed */ |
1640 | static void netlink_update_socket_mc(struct netlink_sock *nlk, |
1641 | unsigned int group, |
1642 | int is_new) |
1643 | { |
1644 | int old, new = !!is_new, subscriptions; |
1645 | |
1646 | old = test_bit(group - 1, nlk->groups); |
1647 | subscriptions = nlk->subscriptions - old + new; |
1648 | __assign_bit(nr: group - 1, addr: nlk->groups, value: new); |
1649 | netlink_update_subscriptions(sk: &nlk->sk, subscriptions); |
1650 | netlink_update_listeners(sk: &nlk->sk); |
1651 | } |
1652 | |
1653 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
1654 | sockptr_t optval, unsigned int optlen) |
1655 | { |
1656 | struct sock *sk = sock->sk; |
1657 | struct netlink_sock *nlk = nlk_sk(sk); |
1658 | unsigned int val = 0; |
1659 | int nr = -1; |
1660 | |
1661 | if (level != SOL_NETLINK) |
1662 | return -ENOPROTOOPT; |
1663 | |
1664 | if (optlen >= sizeof(int) && |
1665 | copy_from_sockptr(dst: &val, src: optval, size: sizeof(val))) |
1666 | return -EFAULT; |
1667 | |
1668 | switch (optname) { |
1669 | case NETLINK_PKTINFO: |
1670 | nr = NETLINK_F_RECV_PKTINFO; |
1671 | break; |
1672 | case NETLINK_ADD_MEMBERSHIP: |
1673 | case NETLINK_DROP_MEMBERSHIP: { |
1674 | int err; |
1675 | |
1676 | if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV)) |
1677 | return -EPERM; |
1678 | err = netlink_realloc_groups(sk); |
1679 | if (err) |
1680 | return err; |
1681 | if (!val || val - 1 >= nlk->ngroups) |
1682 | return -EINVAL; |
1683 | if (optname == NETLINK_ADD_MEMBERSHIP && nlk->netlink_bind) { |
1684 | err = nlk->netlink_bind(sock_net(sk), val); |
1685 | if (err) |
1686 | return err; |
1687 | } |
1688 | netlink_table_grab(); |
1689 | netlink_update_socket_mc(nlk, group: val, |
1690 | is_new: optname == NETLINK_ADD_MEMBERSHIP); |
1691 | netlink_table_ungrab(); |
1692 | if (optname == NETLINK_DROP_MEMBERSHIP && nlk->netlink_unbind) |
1693 | nlk->netlink_unbind(sock_net(sk), val); |
1694 | |
1695 | break; |
1696 | } |
1697 | case NETLINK_BROADCAST_ERROR: |
1698 | nr = NETLINK_F_BROADCAST_SEND_ERROR; |
1699 | break; |
1700 | case NETLINK_NO_ENOBUFS: |
1701 | assign_bit(nr: NETLINK_F_RECV_NO_ENOBUFS, addr: &nlk->flags, value: val); |
1702 | if (val) { |
1703 | clear_bit(NETLINK_S_CONGESTED, addr: &nlk->state); |
1704 | wake_up_interruptible(&nlk->wait); |
1705 | } |
1706 | break; |
1707 | case NETLINK_LISTEN_ALL_NSID: |
1708 | if (!ns_capable(ns: sock_net(sk)->user_ns, CAP_NET_BROADCAST)) |
1709 | return -EPERM; |
1710 | nr = NETLINK_F_LISTEN_ALL_NSID; |
1711 | break; |
1712 | case NETLINK_CAP_ACK: |
1713 | nr = NETLINK_F_CAP_ACK; |
1714 | break; |
1715 | case NETLINK_EXT_ACK: |
1716 | nr = NETLINK_F_EXT_ACK; |
1717 | break; |
1718 | case NETLINK_GET_STRICT_CHK: |
1719 | nr = NETLINK_F_STRICT_CHK; |
1720 | break; |
1721 | default: |
1722 | return -ENOPROTOOPT; |
1723 | } |
1724 | if (nr >= 0) |
1725 | assign_bit(nr, addr: &nlk->flags, value: val); |
1726 | return 0; |
1727 | } |
1728 | |
1729 | static int netlink_getsockopt(struct socket *sock, int level, int optname, |
1730 | char __user *optval, int __user *optlen) |
1731 | { |
1732 | struct sock *sk = sock->sk; |
1733 | struct netlink_sock *nlk = nlk_sk(sk); |
1734 | unsigned int flag; |
1735 | int len, val; |
1736 | |
1737 | if (level != SOL_NETLINK) |
1738 | return -ENOPROTOOPT; |
1739 | |
1740 | if (get_user(len, optlen)) |
1741 | return -EFAULT; |
1742 | if (len < 0) |
1743 | return -EINVAL; |
1744 | |
1745 | switch (optname) { |
1746 | case NETLINK_PKTINFO: |
1747 | flag = NETLINK_F_RECV_PKTINFO; |
1748 | break; |
1749 | case NETLINK_BROADCAST_ERROR: |
1750 | flag = NETLINK_F_BROADCAST_SEND_ERROR; |
1751 | break; |
1752 | case NETLINK_NO_ENOBUFS: |
1753 | flag = NETLINK_F_RECV_NO_ENOBUFS; |
1754 | break; |
1755 | case NETLINK_LIST_MEMBERSHIPS: { |
1756 | int pos, idx, shift, err = 0; |
1757 | |
1758 | netlink_lock_table(); |
1759 | for (pos = 0; pos * 8 < nlk->ngroups; pos += sizeof(u32)) { |
1760 | if (len - pos < sizeof(u32)) |
1761 | break; |
1762 | |
1763 | idx = pos / sizeof(unsigned long); |
1764 | shift = (pos % sizeof(unsigned long)) * 8; |
1765 | if (put_user((u32)(nlk->groups[idx] >> shift), |
1766 | (u32 __user *)(optval + pos))) { |
1767 | err = -EFAULT; |
1768 | break; |
1769 | } |
1770 | } |
1771 | if (put_user(ALIGN(BITS_TO_BYTES(nlk->ngroups), sizeof(u32)), optlen)) |
1772 | err = -EFAULT; |
1773 | netlink_unlock_table(); |
1774 | return err; |
1775 | } |
1776 | case NETLINK_LISTEN_ALL_NSID: |
1777 | flag = NETLINK_F_LISTEN_ALL_NSID; |
1778 | break; |
1779 | case NETLINK_CAP_ACK: |
1780 | flag = NETLINK_F_CAP_ACK; |
1781 | break; |
1782 | case NETLINK_EXT_ACK: |
1783 | flag = NETLINK_F_EXT_ACK; |
1784 | break; |
1785 | case NETLINK_GET_STRICT_CHK: |
1786 | flag = NETLINK_F_STRICT_CHK; |
1787 | break; |
1788 | default: |
1789 | return -ENOPROTOOPT; |
1790 | } |
1791 | |
1792 | if (len < sizeof(int)) |
1793 | return -EINVAL; |
1794 | |
1795 | len = sizeof(int); |
1796 | val = test_bit(flag, &nlk->flags); |
1797 | |
1798 | if (put_user(len, optlen) || |
1799 | copy_to_user(to: optval, from: &val, n: len)) |
1800 | return -EFAULT; |
1801 | |
1802 | return 0; |
1803 | } |
1804 | |
1805 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) |
1806 | { |
1807 | struct nl_pktinfo info; |
1808 | |
1809 | info.group = NETLINK_CB(skb).dst_group; |
1810 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, len: sizeof(info), data: &info); |
1811 | } |
1812 | |
1813 | static void netlink_cmsg_listen_all_nsid(struct sock *sk, struct msghdr *msg, |
1814 | struct sk_buff *skb) |
1815 | { |
1816 | if (!NETLINK_CB(skb).nsid_is_set) |
1817 | return; |
1818 | |
1819 | put_cmsg(msg, SOL_NETLINK, NETLINK_LISTEN_ALL_NSID, len: sizeof(int), |
1820 | data: &NETLINK_CB(skb).nsid); |
1821 | } |
1822 | |
1823 | static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) |
1824 | { |
1825 | struct sock *sk = sock->sk; |
1826 | struct netlink_sock *nlk = nlk_sk(sk); |
1827 | DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name); |
1828 | u32 dst_portid; |
1829 | u32 dst_group; |
1830 | struct sk_buff *skb; |
1831 | int err; |
1832 | struct scm_cookie scm; |
1833 | u32 netlink_skb_flags = 0; |
1834 | |
1835 | if (msg->msg_flags & MSG_OOB) |
1836 | return -EOPNOTSUPP; |
1837 | |
1838 | if (len == 0) { |
1839 | pr_warn_once("Zero length message leads to an empty skb\n" ); |
1840 | return -ENODATA; |
1841 | } |
1842 | |
1843 | err = scm_send(sock, msg, scm: &scm, forcecreds: true); |
1844 | if (err < 0) |
1845 | return err; |
1846 | |
1847 | if (msg->msg_namelen) { |
1848 | err = -EINVAL; |
1849 | if (msg->msg_namelen < sizeof(struct sockaddr_nl)) |
1850 | goto out; |
1851 | if (addr->nl_family != AF_NETLINK) |
1852 | goto out; |
1853 | dst_portid = addr->nl_pid; |
1854 | dst_group = ffs(addr->nl_groups); |
1855 | err = -EPERM; |
1856 | if ((dst_group || dst_portid) && |
1857 | !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND)) |
1858 | goto out; |
1859 | netlink_skb_flags |= NETLINK_SKB_DST; |
1860 | } else { |
1861 | /* Paired with WRITE_ONCE() in netlink_connect() */ |
1862 | dst_portid = READ_ONCE(nlk->dst_portid); |
1863 | dst_group = READ_ONCE(nlk->dst_group); |
1864 | } |
1865 | |
1866 | /* Paired with WRITE_ONCE() in netlink_insert() */ |
1867 | if (!READ_ONCE(nlk->bound)) { |
1868 | err = netlink_autobind(sock); |
1869 | if (err) |
1870 | goto out; |
1871 | } else { |
1872 | /* Ensure nlk is hashed and visible. */ |
1873 | smp_rmb(); |
1874 | } |
1875 | |
1876 | err = -EMSGSIZE; |
1877 | if (len > sk->sk_sndbuf - 32) |
1878 | goto out; |
1879 | err = -ENOBUFS; |
1880 | skb = netlink_alloc_large_skb(size: len, broadcast: dst_group); |
1881 | if (skb == NULL) |
1882 | goto out; |
1883 | |
1884 | NETLINK_CB(skb).portid = nlk->portid; |
1885 | NETLINK_CB(skb).dst_group = dst_group; |
1886 | NETLINK_CB(skb).creds = scm.creds; |
1887 | NETLINK_CB(skb).flags = netlink_skb_flags; |
1888 | |
1889 | err = -EFAULT; |
1890 | if (memcpy_from_msg(data: skb_put(skb, len), msg, len)) { |
1891 | kfree_skb(skb); |
1892 | goto out; |
1893 | } |
1894 | |
1895 | err = security_netlink_send(sk, skb); |
1896 | if (err) { |
1897 | kfree_skb(skb); |
1898 | goto out; |
1899 | } |
1900 | |
1901 | if (dst_group) { |
1902 | refcount_inc(r: &skb->users); |
1903 | netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL); |
1904 | } |
1905 | err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags & MSG_DONTWAIT); |
1906 | |
1907 | out: |
1908 | scm_destroy(scm: &scm); |
1909 | return err; |
1910 | } |
1911 | |
1912 | static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, |
1913 | int flags) |
1914 | { |
1915 | struct scm_cookie scm; |
1916 | struct sock *sk = sock->sk; |
1917 | struct netlink_sock *nlk = nlk_sk(sk); |
1918 | size_t copied, max_recvmsg_len; |
1919 | struct sk_buff *skb, *data_skb; |
1920 | int err, ret; |
1921 | |
1922 | if (flags & MSG_OOB) |
1923 | return -EOPNOTSUPP; |
1924 | |
1925 | copied = 0; |
1926 | |
1927 | skb = skb_recv_datagram(sk, flags, err: &err); |
1928 | if (skb == NULL) |
1929 | goto out; |
1930 | |
1931 | data_skb = skb; |
1932 | |
1933 | #ifdef CONFIG_COMPAT_NETLINK_MESSAGES |
1934 | if (unlikely(skb_shinfo(skb)->frag_list)) { |
1935 | /* |
1936 | * If this skb has a frag_list, then here that means that we |
1937 | * will have to use the frag_list skb's data for compat tasks |
1938 | * and the regular skb's data for normal (non-compat) tasks. |
1939 | * |
1940 | * If we need to send the compat skb, assign it to the |
1941 | * 'data_skb' variable so that it will be used below for data |
1942 | * copying. We keep 'skb' for everything else, including |
1943 | * freeing both later. |
1944 | */ |
1945 | if (flags & MSG_CMSG_COMPAT) |
1946 | data_skb = skb_shinfo(skb)->frag_list; |
1947 | } |
1948 | #endif |
1949 | |
1950 | /* Record the max length of recvmsg() calls for future allocations */ |
1951 | max_recvmsg_len = max(READ_ONCE(nlk->max_recvmsg_len), len); |
1952 | max_recvmsg_len = min_t(size_t, max_recvmsg_len, |
1953 | SKB_WITH_OVERHEAD(32768)); |
1954 | WRITE_ONCE(nlk->max_recvmsg_len, max_recvmsg_len); |
1955 | |
1956 | copied = data_skb->len; |
1957 | if (len < copied) { |
1958 | msg->msg_flags |= MSG_TRUNC; |
1959 | copied = len; |
1960 | } |
1961 | |
1962 | err = skb_copy_datagram_msg(from: data_skb, offset: 0, msg, size: copied); |
1963 | |
1964 | if (msg->msg_name) { |
1965 | DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name); |
1966 | addr->nl_family = AF_NETLINK; |
1967 | addr->nl_pad = 0; |
1968 | addr->nl_pid = NETLINK_CB(skb).portid; |
1969 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1970 | msg->msg_namelen = sizeof(*addr); |
1971 | } |
1972 | |
1973 | if (nlk_test_bit(RECV_PKTINFO, sk)) |
1974 | netlink_cmsg_recv_pktinfo(msg, skb); |
1975 | if (nlk_test_bit(LISTEN_ALL_NSID, sk)) |
1976 | netlink_cmsg_listen_all_nsid(sk, msg, skb); |
1977 | |
1978 | memset(&scm, 0, sizeof(scm)); |
1979 | scm.creds = *NETLINK_CREDS(skb); |
1980 | if (flags & MSG_TRUNC) |
1981 | copied = data_skb->len; |
1982 | |
1983 | skb_free_datagram(sk, skb); |
1984 | |
1985 | if (READ_ONCE(nlk->cb_running) && |
1986 | atomic_read(v: &sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) { |
1987 | ret = netlink_dump(sk, lock_taken: false); |
1988 | if (ret) { |
1989 | WRITE_ONCE(sk->sk_err, -ret); |
1990 | sk_error_report(sk); |
1991 | } |
1992 | } |
1993 | |
1994 | scm_recv(sock, msg, scm: &scm, flags); |
1995 | out: |
1996 | netlink_rcv_wake(sk); |
1997 | return err ? : copied; |
1998 | } |
1999 | |
2000 | static void netlink_data_ready(struct sock *sk) |
2001 | { |
2002 | BUG(); |
2003 | } |
2004 | |
2005 | /* |
2006 | * We export these functions to other modules. They provide a |
2007 | * complete set of kernel non-blocking support for message |
2008 | * queueing. |
2009 | */ |
2010 | |
2011 | struct sock * |
2012 | __netlink_kernel_create(struct net *net, int unit, struct module *module, |
2013 | struct netlink_kernel_cfg *cfg) |
2014 | { |
2015 | struct socket *sock; |
2016 | struct sock *sk; |
2017 | struct netlink_sock *nlk; |
2018 | struct listeners *listeners = NULL; |
2019 | struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL; |
2020 | unsigned int groups; |
2021 | |
2022 | BUG_ON(!nl_table); |
2023 | |
2024 | if (unit < 0 || unit >= MAX_LINKS) |
2025 | return NULL; |
2026 | |
2027 | if (sock_create_lite(PF_NETLINK, type: SOCK_DGRAM, proto: unit, res: &sock)) |
2028 | return NULL; |
2029 | |
2030 | if (__netlink_create(net, sock, dump_cb_mutex: cb_mutex, protocol: unit, kern: 1) < 0) |
2031 | goto out_sock_release_nosk; |
2032 | |
2033 | sk = sock->sk; |
2034 | |
2035 | if (!cfg || cfg->groups < 32) |
2036 | groups = 32; |
2037 | else |
2038 | groups = cfg->groups; |
2039 | |
2040 | listeners = kzalloc(size: sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
2041 | if (!listeners) |
2042 | goto out_sock_release; |
2043 | |
2044 | sk->sk_data_ready = netlink_data_ready; |
2045 | if (cfg && cfg->input) |
2046 | nlk_sk(sk)->netlink_rcv = cfg->input; |
2047 | |
2048 | if (netlink_insert(sk, portid: 0)) |
2049 | goto out_sock_release; |
2050 | |
2051 | nlk = nlk_sk(sk); |
2052 | set_bit(nr: NETLINK_F_KERNEL_SOCKET, addr: &nlk->flags); |
2053 | |
2054 | netlink_table_grab(); |
2055 | if (!nl_table[unit].registered) { |
2056 | nl_table[unit].groups = groups; |
2057 | rcu_assign_pointer(nl_table[unit].listeners, listeners); |
2058 | nl_table[unit].cb_mutex = cb_mutex; |
2059 | nl_table[unit].module = module; |
2060 | if (cfg) { |
2061 | nl_table[unit].bind = cfg->bind; |
2062 | nl_table[unit].unbind = cfg->unbind; |
2063 | nl_table[unit].release = cfg->release; |
2064 | nl_table[unit].flags = cfg->flags; |
2065 | } |
2066 | nl_table[unit].registered = 1; |
2067 | } else { |
2068 | kfree(objp: listeners); |
2069 | nl_table[unit].registered++; |
2070 | } |
2071 | netlink_table_ungrab(); |
2072 | return sk; |
2073 | |
2074 | out_sock_release: |
2075 | kfree(objp: listeners); |
2076 | netlink_kernel_release(sk); |
2077 | return NULL; |
2078 | |
2079 | out_sock_release_nosk: |
2080 | sock_release(sock); |
2081 | return NULL; |
2082 | } |
2083 | EXPORT_SYMBOL(__netlink_kernel_create); |
2084 | |
2085 | void |
2086 | netlink_kernel_release(struct sock *sk) |
2087 | { |
2088 | if (sk == NULL || sk->sk_socket == NULL) |
2089 | return; |
2090 | |
2091 | sock_release(sock: sk->sk_socket); |
2092 | } |
2093 | EXPORT_SYMBOL(netlink_kernel_release); |
2094 | |
2095 | int __netlink_change_ngroups(struct sock *sk, unsigned int groups) |
2096 | { |
2097 | struct listeners *new, *old; |
2098 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; |
2099 | |
2100 | if (groups < 32) |
2101 | groups = 32; |
2102 | |
2103 | if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { |
2104 | new = kzalloc(size: sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC); |
2105 | if (!new) |
2106 | return -ENOMEM; |
2107 | old = nl_deref_protected(tbl->listeners); |
2108 | memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups)); |
2109 | rcu_assign_pointer(tbl->listeners, new); |
2110 | |
2111 | kfree_rcu(old, rcu); |
2112 | } |
2113 | tbl->groups = groups; |
2114 | |
2115 | return 0; |
2116 | } |
2117 | |
2118 | /** |
2119 | * netlink_change_ngroups - change number of multicast groups |
2120 | * |
2121 | * This changes the number of multicast groups that are available |
2122 | * on a certain netlink family. Note that it is not possible to |
2123 | * change the number of groups to below 32. Also note that it does |
2124 | * not implicitly call netlink_clear_multicast_users() when the |
2125 | * number of groups is reduced. |
2126 | * |
2127 | * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). |
2128 | * @groups: The new number of groups. |
2129 | */ |
2130 | int netlink_change_ngroups(struct sock *sk, unsigned int groups) |
2131 | { |
2132 | int err; |
2133 | |
2134 | netlink_table_grab(); |
2135 | err = __netlink_change_ngroups(sk, groups); |
2136 | netlink_table_ungrab(); |
2137 | |
2138 | return err; |
2139 | } |
2140 | |
2141 | void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group) |
2142 | { |
2143 | struct sock *sk; |
2144 | struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; |
2145 | |
2146 | sk_for_each_bound(sk, &tbl->mc_list) |
2147 | netlink_update_socket_mc(nlk: nlk_sk(sk), group, is_new: 0); |
2148 | } |
2149 | |
2150 | struct nlmsghdr * |
2151 | __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags) |
2152 | { |
2153 | struct nlmsghdr *nlh; |
2154 | int size = nlmsg_msg_size(payload: len); |
2155 | |
2156 | nlh = skb_put(skb, NLMSG_ALIGN(size)); |
2157 | nlh->nlmsg_type = type; |
2158 | nlh->nlmsg_len = size; |
2159 | nlh->nlmsg_flags = flags; |
2160 | nlh->nlmsg_pid = portid; |
2161 | nlh->nlmsg_seq = seq; |
2162 | if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0) |
2163 | memset(nlmsg_data(nlh) + len, 0, NLMSG_ALIGN(size) - size); |
2164 | return nlh; |
2165 | } |
2166 | EXPORT_SYMBOL(__nlmsg_put); |
2167 | |
2168 | /* |
2169 | * It looks a bit ugly. |
2170 | * It would be better to create kernel thread. |
2171 | */ |
2172 | |
2173 | static int netlink_dump_done(struct netlink_sock *nlk, struct sk_buff *skb, |
2174 | struct netlink_callback *cb, |
2175 | struct netlink_ext_ack *extack) |
2176 | { |
2177 | struct nlmsghdr *nlh; |
2178 | |
2179 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, payload: sizeof(nlk->dump_done_errno), |
2180 | NLM_F_MULTI | cb->answer_flags); |
2181 | if (WARN_ON(!nlh)) |
2182 | return -ENOBUFS; |
2183 | |
2184 | nl_dump_check_consistent(cb, nlh); |
2185 | memcpy(nlmsg_data(nlh), &nlk->dump_done_errno, sizeof(nlk->dump_done_errno)); |
2186 | |
2187 | if (extack->_msg && test_bit(NETLINK_F_EXT_ACK, &nlk->flags)) { |
2188 | nlh->nlmsg_flags |= NLM_F_ACK_TLVS; |
2189 | if (!nla_put_string(skb, attrtype: NLMSGERR_ATTR_MSG, str: extack->_msg)) |
2190 | nlmsg_end(skb, nlh); |
2191 | } |
2192 | |
2193 | return 0; |
2194 | } |
2195 | |
2196 | static int netlink_dump(struct sock *sk, bool lock_taken) |
2197 | { |
2198 | struct netlink_sock *nlk = nlk_sk(sk); |
2199 | struct netlink_ext_ack extack = {}; |
2200 | struct netlink_callback *cb; |
2201 | struct sk_buff *skb = NULL; |
2202 | size_t max_recvmsg_len; |
2203 | struct module *module; |
2204 | int err = -ENOBUFS; |
2205 | int alloc_min_size; |
2206 | int alloc_size; |
2207 | |
2208 | if (!lock_taken) |
2209 | mutex_lock(&nlk->nl_cb_mutex); |
2210 | if (!nlk->cb_running) { |
2211 | err = -EINVAL; |
2212 | goto errout_skb; |
2213 | } |
2214 | |
2215 | if (atomic_read(v: &sk->sk_rmem_alloc) >= sk->sk_rcvbuf) |
2216 | goto errout_skb; |
2217 | |
2218 | /* NLMSG_GOODSIZE is small to avoid high order allocations being |
2219 | * required, but it makes sense to _attempt_ a 16K bytes allocation |
2220 | * to reduce number of system calls on dump operations, if user |
2221 | * ever provided a big enough buffer. |
2222 | */ |
2223 | cb = &nlk->cb; |
2224 | alloc_min_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE); |
2225 | |
2226 | max_recvmsg_len = READ_ONCE(nlk->max_recvmsg_len); |
2227 | if (alloc_min_size < max_recvmsg_len) { |
2228 | alloc_size = max_recvmsg_len; |
2229 | skb = alloc_skb(size: alloc_size, |
2230 | priority: (GFP_KERNEL & ~__GFP_DIRECT_RECLAIM) | |
2231 | __GFP_NOWARN | __GFP_NORETRY); |
2232 | } |
2233 | if (!skb) { |
2234 | alloc_size = alloc_min_size; |
2235 | skb = alloc_skb(size: alloc_size, GFP_KERNEL); |
2236 | } |
2237 | if (!skb) |
2238 | goto errout_skb; |
2239 | |
2240 | /* Trim skb to allocated size. User is expected to provide buffer as |
2241 | * large as max(min_dump_alloc, 16KiB (mac_recvmsg_len capped at |
2242 | * netlink_recvmsg())). dump will pack as many smaller messages as |
2243 | * could fit within the allocated skb. skb is typically allocated |
2244 | * with larger space than required (could be as much as near 2x the |
2245 | * requested size with align to next power of 2 approach). Allowing |
2246 | * dump to use the excess space makes it difficult for a user to have a |
2247 | * reasonable static buffer based on the expected largest dump of a |
2248 | * single netdev. The outcome is MSG_TRUNC error. |
2249 | */ |
2250 | skb_reserve(skb, len: skb_tailroom(skb) - alloc_size); |
2251 | |
2252 | /* Make sure malicious BPF programs can not read unitialized memory |
2253 | * from skb->head -> skb->data |
2254 | */ |
2255 | skb_reset_network_header(skb); |
2256 | skb_reset_mac_header(skb); |
2257 | |
2258 | netlink_skb_set_owner_r(skb, sk); |
2259 | |
2260 | if (nlk->dump_done_errno > 0) { |
2261 | struct mutex * = nlk->dump_cb_mutex; |
2262 | |
2263 | cb->extack = &extack; |
2264 | |
2265 | if (cb->flags & RTNL_FLAG_DUMP_UNLOCKED) |
2266 | extra_mutex = NULL; |
2267 | if (extra_mutex) |
2268 | mutex_lock(extra_mutex); |
2269 | nlk->dump_done_errno = cb->dump(skb, cb); |
2270 | if (extra_mutex) |
2271 | mutex_unlock(lock: extra_mutex); |
2272 | |
2273 | /* EMSGSIZE plus something already in the skb means |
2274 | * that there's more to dump but current skb has filled up. |
2275 | * If the callback really wants to return EMSGSIZE to user space |
2276 | * it needs to do so again, on the next cb->dump() call, |
2277 | * without putting data in the skb. |
2278 | */ |
2279 | if (nlk->dump_done_errno == -EMSGSIZE && skb->len) |
2280 | nlk->dump_done_errno = skb->len; |
2281 | |
2282 | cb->extack = NULL; |
2283 | } |
2284 | |
2285 | if (nlk->dump_done_errno > 0 || |
2286 | skb_tailroom(skb) < nlmsg_total_size(payload: sizeof(nlk->dump_done_errno))) { |
2287 | mutex_unlock(lock: &nlk->nl_cb_mutex); |
2288 | |
2289 | if (sk_filter(sk, skb)) |
2290 | kfree_skb(skb); |
2291 | else |
2292 | __netlink_sendskb(sk, skb); |
2293 | return 0; |
2294 | } |
2295 | |
2296 | if (netlink_dump_done(nlk, skb, cb, extack: &extack)) |
2297 | goto errout_skb; |
2298 | |
2299 | #ifdef CONFIG_COMPAT_NETLINK_MESSAGES |
2300 | /* frag_list skb's data is used for compat tasks |
2301 | * and the regular skb's data for normal (non-compat) tasks. |
2302 | * See netlink_recvmsg(). |
2303 | */ |
2304 | if (unlikely(skb_shinfo(skb)->frag_list)) { |
2305 | if (netlink_dump_done(nlk, skb_shinfo(skb)->frag_list, cb, extack: &extack)) |
2306 | goto errout_skb; |
2307 | } |
2308 | #endif |
2309 | |
2310 | if (sk_filter(sk, skb)) |
2311 | kfree_skb(skb); |
2312 | else |
2313 | __netlink_sendskb(sk, skb); |
2314 | |
2315 | if (cb->done) |
2316 | cb->done(cb); |
2317 | |
2318 | WRITE_ONCE(nlk->cb_running, false); |
2319 | module = cb->module; |
2320 | skb = cb->skb; |
2321 | mutex_unlock(lock: &nlk->nl_cb_mutex); |
2322 | module_put(module); |
2323 | consume_skb(skb); |
2324 | return 0; |
2325 | |
2326 | errout_skb: |
2327 | mutex_unlock(lock: &nlk->nl_cb_mutex); |
2328 | kfree_skb(skb); |
2329 | return err; |
2330 | } |
2331 | |
2332 | int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, |
2333 | const struct nlmsghdr *nlh, |
2334 | struct netlink_dump_control *control) |
2335 | { |
2336 | struct netlink_callback *cb; |
2337 | struct netlink_sock *nlk; |
2338 | struct sock *sk; |
2339 | int ret; |
2340 | |
2341 | refcount_inc(r: &skb->users); |
2342 | |
2343 | sk = netlink_lookup(net: sock_net(sk: ssk), protocol: ssk->sk_protocol, NETLINK_CB(skb).portid); |
2344 | if (sk == NULL) { |
2345 | ret = -ECONNREFUSED; |
2346 | goto error_free; |
2347 | } |
2348 | |
2349 | nlk = nlk_sk(sk); |
2350 | mutex_lock(&nlk->nl_cb_mutex); |
2351 | /* A dump is in progress... */ |
2352 | if (nlk->cb_running) { |
2353 | ret = -EBUSY; |
2354 | goto error_unlock; |
2355 | } |
2356 | /* add reference of module which cb->dump belongs to */ |
2357 | if (!try_module_get(module: control->module)) { |
2358 | ret = -EPROTONOSUPPORT; |
2359 | goto error_unlock; |
2360 | } |
2361 | |
2362 | cb = &nlk->cb; |
2363 | memset(cb, 0, sizeof(*cb)); |
2364 | cb->dump = control->dump; |
2365 | cb->done = control->done; |
2366 | cb->nlh = nlh; |
2367 | cb->data = control->data; |
2368 | cb->module = control->module; |
2369 | cb->min_dump_alloc = control->min_dump_alloc; |
2370 | cb->flags = control->flags; |
2371 | cb->skb = skb; |
2372 | |
2373 | cb->strict_check = nlk_test_bit(STRICT_CHK, NETLINK_CB(skb).sk); |
2374 | |
2375 | if (control->start) { |
2376 | cb->extack = control->extack; |
2377 | ret = control->start(cb); |
2378 | cb->extack = NULL; |
2379 | if (ret) |
2380 | goto error_put; |
2381 | } |
2382 | |
2383 | WRITE_ONCE(nlk->cb_running, true); |
2384 | nlk->dump_done_errno = INT_MAX; |
2385 | |
2386 | ret = netlink_dump(sk, lock_taken: true); |
2387 | |
2388 | sock_put(sk); |
2389 | |
2390 | if (ret) |
2391 | return ret; |
2392 | |
2393 | /* We successfully started a dump, by returning -EINTR we |
2394 | * signal not to send ACK even if it was requested. |
2395 | */ |
2396 | return -EINTR; |
2397 | |
2398 | error_put: |
2399 | module_put(module: control->module); |
2400 | error_unlock: |
2401 | sock_put(sk); |
2402 | mutex_unlock(lock: &nlk->nl_cb_mutex); |
2403 | error_free: |
2404 | kfree_skb(skb); |
2405 | return ret; |
2406 | } |
2407 | EXPORT_SYMBOL(__netlink_dump_start); |
2408 | |
2409 | static size_t |
2410 | netlink_ack_tlv_len(struct netlink_sock *nlk, int err, |
2411 | const struct netlink_ext_ack *extack) |
2412 | { |
2413 | size_t tlvlen; |
2414 | |
2415 | if (!extack || !test_bit(NETLINK_F_EXT_ACK, &nlk->flags)) |
2416 | return 0; |
2417 | |
2418 | tlvlen = 0; |
2419 | if (extack->_msg) |
2420 | tlvlen += nla_total_size(strlen(extack->_msg) + 1); |
2421 | if (extack->cookie_len) |
2422 | tlvlen += nla_total_size(payload: extack->cookie_len); |
2423 | |
2424 | /* Following attributes are only reported as error (not warning) */ |
2425 | if (!err) |
2426 | return tlvlen; |
2427 | |
2428 | if (extack->bad_attr) |
2429 | tlvlen += nla_total_size(payload: sizeof(u32)); |
2430 | if (extack->policy) |
2431 | tlvlen += netlink_policy_dump_attr_size_estimate(pt: extack->policy); |
2432 | if (extack->miss_type) |
2433 | tlvlen += nla_total_size(payload: sizeof(u32)); |
2434 | if (extack->miss_nest) |
2435 | tlvlen += nla_total_size(payload: sizeof(u32)); |
2436 | |
2437 | return tlvlen; |
2438 | } |
2439 | |
2440 | static void |
2441 | netlink_ack_tlv_fill(struct sk_buff *in_skb, struct sk_buff *skb, |
2442 | struct nlmsghdr *nlh, int err, |
2443 | const struct netlink_ext_ack *extack) |
2444 | { |
2445 | if (extack->_msg) |
2446 | WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG, extack->_msg)); |
2447 | if (extack->cookie_len) |
2448 | WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE, |
2449 | extack->cookie_len, extack->cookie)); |
2450 | |
2451 | if (!err) |
2452 | return; |
2453 | |
2454 | if (extack->bad_attr && |
2455 | !WARN_ON((u8 *)extack->bad_attr < in_skb->data || |
2456 | (u8 *)extack->bad_attr >= in_skb->data + in_skb->len)) |
2457 | WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS, |
2458 | (u8 *)extack->bad_attr - (u8 *)nlh)); |
2459 | if (extack->policy) |
2460 | netlink_policy_dump_write_attr(skb, pt: extack->policy, |
2461 | nestattr: NLMSGERR_ATTR_POLICY); |
2462 | if (extack->miss_type) |
2463 | WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_MISS_TYPE, |
2464 | extack->miss_type)); |
2465 | if (extack->miss_nest && |
2466 | !WARN_ON((u8 *)extack->miss_nest < in_skb->data || |
2467 | (u8 *)extack->miss_nest > in_skb->data + in_skb->len)) |
2468 | WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_MISS_NEST, |
2469 | (u8 *)extack->miss_nest - (u8 *)nlh)); |
2470 | } |
2471 | |
2472 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, |
2473 | const struct netlink_ext_ack *extack) |
2474 | { |
2475 | struct sk_buff *skb; |
2476 | struct nlmsghdr *rep; |
2477 | struct nlmsgerr *errmsg; |
2478 | size_t payload = sizeof(*errmsg); |
2479 | struct netlink_sock *nlk = nlk_sk(NETLINK_CB(in_skb).sk); |
2480 | unsigned int flags = 0; |
2481 | size_t tlvlen; |
2482 | |
2483 | /* Error messages get the original request appened, unless the user |
2484 | * requests to cap the error message, and get extra error data if |
2485 | * requested. |
2486 | */ |
2487 | if (err && !test_bit(NETLINK_F_CAP_ACK, &nlk->flags)) |
2488 | payload += nlmsg_len(nlh); |
2489 | else |
2490 | flags |= NLM_F_CAPPED; |
2491 | |
2492 | tlvlen = netlink_ack_tlv_len(nlk, err, extack); |
2493 | if (tlvlen) |
2494 | flags |= NLM_F_ACK_TLVS; |
2495 | |
2496 | skb = nlmsg_new(payload: payload + tlvlen, GFP_KERNEL); |
2497 | if (!skb) |
2498 | goto err_skb; |
2499 | |
2500 | rep = nlmsg_put(skb, NETLINK_CB(in_skb).portid, seq: nlh->nlmsg_seq, |
2501 | NLMSG_ERROR, payload: sizeof(*errmsg), flags); |
2502 | if (!rep) |
2503 | goto err_bad_put; |
2504 | errmsg = nlmsg_data(nlh: rep); |
2505 | errmsg->error = err; |
2506 | errmsg->msg = *nlh; |
2507 | |
2508 | if (!(flags & NLM_F_CAPPED)) { |
2509 | if (!nlmsg_append(skb, size: nlmsg_len(nlh))) |
2510 | goto err_bad_put; |
2511 | |
2512 | memcpy(nlmsg_data(&errmsg->msg), nlmsg_data(nlh), |
2513 | nlmsg_len(nlh)); |
2514 | } |
2515 | |
2516 | if (tlvlen) |
2517 | netlink_ack_tlv_fill(in_skb, skb, nlh, err, extack); |
2518 | |
2519 | nlmsg_end(skb, nlh: rep); |
2520 | |
2521 | nlmsg_unicast(sk: in_skb->sk, skb, NETLINK_CB(in_skb).portid); |
2522 | |
2523 | return; |
2524 | |
2525 | err_bad_put: |
2526 | nlmsg_free(skb); |
2527 | err_skb: |
2528 | WRITE_ONCE(NETLINK_CB(in_skb).sk->sk_err, ENOBUFS); |
2529 | sk_error_report(NETLINK_CB(in_skb).sk); |
2530 | } |
2531 | EXPORT_SYMBOL(netlink_ack); |
2532 | |
2533 | int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
2534 | struct nlmsghdr *, |
2535 | struct netlink_ext_ack *)) |
2536 | { |
2537 | struct netlink_ext_ack extack; |
2538 | struct nlmsghdr *nlh; |
2539 | int err; |
2540 | |
2541 | while (skb->len >= nlmsg_total_size(payload: 0)) { |
2542 | int msglen; |
2543 | |
2544 | memset(&extack, 0, sizeof(extack)); |
2545 | nlh = nlmsg_hdr(skb); |
2546 | err = 0; |
2547 | |
2548 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
2549 | return 0; |
2550 | |
2551 | /* Only requests are handled by the kernel */ |
2552 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) |
2553 | goto ack; |
2554 | |
2555 | /* Skip control messages */ |
2556 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) |
2557 | goto ack; |
2558 | |
2559 | err = cb(skb, nlh, &extack); |
2560 | if (err == -EINTR) |
2561 | goto skip; |
2562 | |
2563 | ack: |
2564 | if (nlh->nlmsg_flags & NLM_F_ACK || err) |
2565 | netlink_ack(skb, nlh, err, &extack); |
2566 | |
2567 | skip: |
2568 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
2569 | if (msglen > skb->len) |
2570 | msglen = skb->len; |
2571 | skb_pull(skb, len: msglen); |
2572 | } |
2573 | |
2574 | return 0; |
2575 | } |
2576 | EXPORT_SYMBOL(netlink_rcv_skb); |
2577 | |
2578 | /** |
2579 | * nlmsg_notify - send a notification netlink message |
2580 | * @sk: netlink socket to use |
2581 | * @skb: notification message |
2582 | * @portid: destination netlink portid for reports or 0 |
2583 | * @group: destination multicast group or 0 |
2584 | * @report: 1 to report back, 0 to disable |
2585 | * @flags: allocation flags |
2586 | */ |
2587 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, |
2588 | unsigned int group, int report, gfp_t flags) |
2589 | { |
2590 | int err = 0; |
2591 | |
2592 | if (group) { |
2593 | int exclude_portid = 0; |
2594 | |
2595 | if (report) { |
2596 | refcount_inc(r: &skb->users); |
2597 | exclude_portid = portid; |
2598 | } |
2599 | |
2600 | /* errors reported via destination sk->sk_err, but propagate |
2601 | * delivery errors if NETLINK_BROADCAST_ERROR flag is set */ |
2602 | err = nlmsg_multicast(sk, skb, portid: exclude_portid, group, flags); |
2603 | if (err == -ESRCH) |
2604 | err = 0; |
2605 | } |
2606 | |
2607 | if (report) { |
2608 | int err2; |
2609 | |
2610 | err2 = nlmsg_unicast(sk, skb, portid); |
2611 | if (!err) |
2612 | err = err2; |
2613 | } |
2614 | |
2615 | return err; |
2616 | } |
2617 | EXPORT_SYMBOL(nlmsg_notify); |
2618 | |
2619 | #ifdef CONFIG_PROC_FS |
2620 | struct nl_seq_iter { |
2621 | struct seq_net_private p; |
2622 | struct rhashtable_iter hti; |
2623 | int link; |
2624 | }; |
2625 | |
2626 | static void netlink_walk_start(struct nl_seq_iter *iter) |
2627 | { |
2628 | rhashtable_walk_enter(ht: &nl_table[iter->link].hash, iter: &iter->hti); |
2629 | rhashtable_walk_start(iter: &iter->hti); |
2630 | } |
2631 | |
2632 | static void netlink_walk_stop(struct nl_seq_iter *iter) |
2633 | { |
2634 | rhashtable_walk_stop(iter: &iter->hti); |
2635 | rhashtable_walk_exit(iter: &iter->hti); |
2636 | } |
2637 | |
2638 | static void *__netlink_seq_next(struct seq_file *seq) |
2639 | { |
2640 | struct nl_seq_iter *iter = seq->private; |
2641 | struct netlink_sock *nlk; |
2642 | |
2643 | do { |
2644 | for (;;) { |
2645 | nlk = rhashtable_walk_next(iter: &iter->hti); |
2646 | |
2647 | if (IS_ERR(ptr: nlk)) { |
2648 | if (PTR_ERR(ptr: nlk) == -EAGAIN) |
2649 | continue; |
2650 | |
2651 | return nlk; |
2652 | } |
2653 | |
2654 | if (nlk) |
2655 | break; |
2656 | |
2657 | netlink_walk_stop(iter); |
2658 | if (++iter->link >= MAX_LINKS) |
2659 | return NULL; |
2660 | |
2661 | netlink_walk_start(iter); |
2662 | } |
2663 | } while (sock_net(sk: &nlk->sk) != seq_file_net(seq)); |
2664 | |
2665 | return nlk; |
2666 | } |
2667 | |
2668 | static void *netlink_seq_start(struct seq_file *seq, loff_t *posp) |
2669 | __acquires(RCU) |
2670 | { |
2671 | struct nl_seq_iter *iter = seq->private; |
2672 | void *obj = SEQ_START_TOKEN; |
2673 | loff_t pos; |
2674 | |
2675 | iter->link = 0; |
2676 | |
2677 | netlink_walk_start(iter); |
2678 | |
2679 | for (pos = *posp; pos && obj && !IS_ERR(ptr: obj); pos--) |
2680 | obj = __netlink_seq_next(seq); |
2681 | |
2682 | return obj; |
2683 | } |
2684 | |
2685 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
2686 | { |
2687 | ++*pos; |
2688 | return __netlink_seq_next(seq); |
2689 | } |
2690 | |
2691 | static void netlink_native_seq_stop(struct seq_file *seq, void *v) |
2692 | { |
2693 | struct nl_seq_iter *iter = seq->private; |
2694 | |
2695 | if (iter->link >= MAX_LINKS) |
2696 | return; |
2697 | |
2698 | netlink_walk_stop(iter); |
2699 | } |
2700 | |
2701 | |
2702 | static int netlink_native_seq_show(struct seq_file *seq, void *v) |
2703 | { |
2704 | if (v == SEQ_START_TOKEN) { |
2705 | seq_puts(m: seq, |
2706 | s: "sk Eth Pid Groups " |
2707 | "Rmem Wmem Dump Locks Drops Inode\n" ); |
2708 | } else { |
2709 | struct sock *s = v; |
2710 | struct netlink_sock *nlk = nlk_sk(sk: s); |
2711 | |
2712 | seq_printf(m: seq, fmt: "%pK %-3d %-10u %08x %-8d %-8d %-5d %-8d %-8u %-8lu\n" , |
2713 | s, |
2714 | s->sk_protocol, |
2715 | nlk->portid, |
2716 | nlk->groups ? (u32)nlk->groups[0] : 0, |
2717 | sk_rmem_alloc_get(sk: s), |
2718 | sk_wmem_alloc_get(sk: s), |
2719 | READ_ONCE(nlk->cb_running), |
2720 | refcount_read(r: &s->sk_refcnt), |
2721 | atomic_read(v: &s->sk_drops), |
2722 | sock_i_ino(sk: s) |
2723 | ); |
2724 | |
2725 | } |
2726 | return 0; |
2727 | } |
2728 | |
2729 | #ifdef CONFIG_BPF_SYSCALL |
2730 | struct bpf_iter__netlink { |
2731 | __bpf_md_ptr(struct bpf_iter_meta *, meta); |
2732 | __bpf_md_ptr(struct netlink_sock *, sk); |
2733 | }; |
2734 | |
2735 | DEFINE_BPF_ITER_FUNC(netlink, struct bpf_iter_meta *meta, struct netlink_sock *sk) |
2736 | |
2737 | static int netlink_prog_seq_show(struct bpf_prog *prog, |
2738 | struct bpf_iter_meta *meta, |
2739 | void *v) |
2740 | { |
2741 | struct bpf_iter__netlink ctx; |
2742 | |
2743 | meta->seq_num--; /* skip SEQ_START_TOKEN */ |
2744 | ctx.meta = meta; |
2745 | ctx.sk = nlk_sk(sk: (struct sock *)v); |
2746 | return bpf_iter_run_prog(prog, ctx: &ctx); |
2747 | } |
2748 | |
2749 | static int netlink_seq_show(struct seq_file *seq, void *v) |
2750 | { |
2751 | struct bpf_iter_meta meta; |
2752 | struct bpf_prog *prog; |
2753 | |
2754 | meta.seq = seq; |
2755 | prog = bpf_iter_get_info(meta: &meta, in_stop: false); |
2756 | if (!prog) |
2757 | return netlink_native_seq_show(seq, v); |
2758 | |
2759 | if (v != SEQ_START_TOKEN) |
2760 | return netlink_prog_seq_show(prog, meta: &meta, v); |
2761 | |
2762 | return 0; |
2763 | } |
2764 | |
2765 | static void netlink_seq_stop(struct seq_file *seq, void *v) |
2766 | { |
2767 | struct bpf_iter_meta meta; |
2768 | struct bpf_prog *prog; |
2769 | |
2770 | if (!v) { |
2771 | meta.seq = seq; |
2772 | prog = bpf_iter_get_info(meta: &meta, in_stop: true); |
2773 | if (prog) |
2774 | (void)netlink_prog_seq_show(prog, meta: &meta, v); |
2775 | } |
2776 | |
2777 | netlink_native_seq_stop(seq, v); |
2778 | } |
2779 | #else |
2780 | static int netlink_seq_show(struct seq_file *seq, void *v) |
2781 | { |
2782 | return netlink_native_seq_show(seq, v); |
2783 | } |
2784 | |
2785 | static void netlink_seq_stop(struct seq_file *seq, void *v) |
2786 | { |
2787 | netlink_native_seq_stop(seq, v); |
2788 | } |
2789 | #endif |
2790 | |
2791 | static const struct seq_operations netlink_seq_ops = { |
2792 | .start = netlink_seq_start, |
2793 | .next = netlink_seq_next, |
2794 | .stop = netlink_seq_stop, |
2795 | .show = netlink_seq_show, |
2796 | }; |
2797 | #endif |
2798 | |
2799 | int netlink_register_notifier(struct notifier_block *nb) |
2800 | { |
2801 | return blocking_notifier_chain_register(nh: &netlink_chain, nb); |
2802 | } |
2803 | EXPORT_SYMBOL(netlink_register_notifier); |
2804 | |
2805 | int netlink_unregister_notifier(struct notifier_block *nb) |
2806 | { |
2807 | return blocking_notifier_chain_unregister(nh: &netlink_chain, nb); |
2808 | } |
2809 | EXPORT_SYMBOL(netlink_unregister_notifier); |
2810 | |
2811 | static const struct proto_ops netlink_ops = { |
2812 | .family = PF_NETLINK, |
2813 | .owner = THIS_MODULE, |
2814 | .release = netlink_release, |
2815 | .bind = netlink_bind, |
2816 | .connect = netlink_connect, |
2817 | .socketpair = sock_no_socketpair, |
2818 | .accept = sock_no_accept, |
2819 | .getname = netlink_getname, |
2820 | .poll = datagram_poll, |
2821 | .ioctl = netlink_ioctl, |
2822 | .listen = sock_no_listen, |
2823 | .shutdown = sock_no_shutdown, |
2824 | .setsockopt = netlink_setsockopt, |
2825 | .getsockopt = netlink_getsockopt, |
2826 | .sendmsg = netlink_sendmsg, |
2827 | .recvmsg = netlink_recvmsg, |
2828 | .mmap = sock_no_mmap, |
2829 | }; |
2830 | |
2831 | static const struct net_proto_family netlink_family_ops = { |
2832 | .family = PF_NETLINK, |
2833 | .create = netlink_create, |
2834 | .owner = THIS_MODULE, /* for consistency 8) */ |
2835 | }; |
2836 | |
2837 | static int __net_init netlink_net_init(struct net *net) |
2838 | { |
2839 | #ifdef CONFIG_PROC_FS |
2840 | if (!proc_create_net("netlink" , 0, net->proc_net, &netlink_seq_ops, |
2841 | sizeof(struct nl_seq_iter))) |
2842 | return -ENOMEM; |
2843 | #endif |
2844 | return 0; |
2845 | } |
2846 | |
2847 | static void __net_exit netlink_net_exit(struct net *net) |
2848 | { |
2849 | #ifdef CONFIG_PROC_FS |
2850 | remove_proc_entry("netlink" , net->proc_net); |
2851 | #endif |
2852 | } |
2853 | |
2854 | static void __init netlink_add_usersock_entry(void) |
2855 | { |
2856 | struct listeners *listeners; |
2857 | int groups = 32; |
2858 | |
2859 | listeners = kzalloc(size: sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
2860 | if (!listeners) |
2861 | panic(fmt: "netlink_add_usersock_entry: Cannot allocate listeners\n" ); |
2862 | |
2863 | netlink_table_grab(); |
2864 | |
2865 | nl_table[NETLINK_USERSOCK].groups = groups; |
2866 | rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners); |
2867 | nl_table[NETLINK_USERSOCK].module = THIS_MODULE; |
2868 | nl_table[NETLINK_USERSOCK].registered = 1; |
2869 | nl_table[NETLINK_USERSOCK].flags = NL_CFG_F_NONROOT_SEND; |
2870 | |
2871 | netlink_table_ungrab(); |
2872 | } |
2873 | |
2874 | static struct pernet_operations __net_initdata netlink_net_ops = { |
2875 | .init = netlink_net_init, |
2876 | .exit = netlink_net_exit, |
2877 | }; |
2878 | |
2879 | static inline u32 netlink_hash(const void *data, u32 len, u32 seed) |
2880 | { |
2881 | const struct netlink_sock *nlk = data; |
2882 | struct netlink_compare_arg arg; |
2883 | |
2884 | netlink_compare_arg_init(arg: &arg, net: sock_net(sk: &nlk->sk), portid: nlk->portid); |
2885 | return jhash2(k: (u32 *)&arg, netlink_compare_arg_len / sizeof(u32), initval: seed); |
2886 | } |
2887 | |
2888 | static const struct rhashtable_params netlink_rhashtable_params = { |
2889 | .head_offset = offsetof(struct netlink_sock, node), |
2890 | .key_len = netlink_compare_arg_len, |
2891 | .obj_hashfn = netlink_hash, |
2892 | .obj_cmpfn = netlink_compare, |
2893 | .automatic_shrinking = true, |
2894 | }; |
2895 | |
2896 | #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) |
2897 | BTF_ID_LIST(btf_netlink_sock_id) |
2898 | BTF_ID(struct, netlink_sock) |
2899 | |
2900 | static const struct bpf_iter_seq_info netlink_seq_info = { |
2901 | .seq_ops = &netlink_seq_ops, |
2902 | .init_seq_private = bpf_iter_init_seq_net, |
2903 | .fini_seq_private = bpf_iter_fini_seq_net, |
2904 | .seq_priv_size = sizeof(struct nl_seq_iter), |
2905 | }; |
2906 | |
2907 | static struct bpf_iter_reg netlink_reg_info = { |
2908 | .target = "netlink" , |
2909 | .ctx_arg_info_size = 1, |
2910 | .ctx_arg_info = { |
2911 | { offsetof(struct bpf_iter__netlink, sk), |
2912 | PTR_TO_BTF_ID_OR_NULL }, |
2913 | }, |
2914 | .seq_info = &netlink_seq_info, |
2915 | }; |
2916 | |
2917 | static int __init bpf_iter_register(void) |
2918 | { |
2919 | netlink_reg_info.ctx_arg_info[0].btf_id = *btf_netlink_sock_id; |
2920 | return bpf_iter_reg_target(reg_info: &netlink_reg_info); |
2921 | } |
2922 | #endif |
2923 | |
2924 | static int __init netlink_proto_init(void) |
2925 | { |
2926 | int i; |
2927 | int err = proto_register(prot: &netlink_proto, alloc_slab: 0); |
2928 | |
2929 | if (err != 0) |
2930 | goto out; |
2931 | |
2932 | #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) |
2933 | err = bpf_iter_register(); |
2934 | if (err) |
2935 | goto out; |
2936 | #endif |
2937 | |
2938 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof_field(struct sk_buff, cb)); |
2939 | |
2940 | nl_table = kcalloc(MAX_LINKS, size: sizeof(*nl_table), GFP_KERNEL); |
2941 | if (!nl_table) |
2942 | goto panic; |
2943 | |
2944 | for (i = 0; i < MAX_LINKS; i++) { |
2945 | if (rhashtable_init(ht: &nl_table[i].hash, |
2946 | params: &netlink_rhashtable_params) < 0) { |
2947 | while (--i > 0) |
2948 | rhashtable_destroy(ht: &nl_table[i].hash); |
2949 | kfree(objp: nl_table); |
2950 | goto panic; |
2951 | } |
2952 | } |
2953 | |
2954 | netlink_add_usersock_entry(); |
2955 | |
2956 | sock_register(fam: &netlink_family_ops); |
2957 | register_pernet_subsys(&netlink_net_ops); |
2958 | register_pernet_subsys(&netlink_tap_net_ops); |
2959 | /* The netlink device handler may be needed early. */ |
2960 | rtnetlink_init(); |
2961 | out: |
2962 | return err; |
2963 | panic: |
2964 | panic(fmt: "netlink_init: Cannot allocate nl_table\n" ); |
2965 | } |
2966 | |
2967 | core_initcall(netlink_proto_init); |
2968 | |