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21#include <linux/module.h>
22
23#include <linux/capability.h>
24#include <linux/kernel.h>
25#include <linux/init.h>
26#include <linux/signal.h>
27#include <linux/sched.h>
28#include <linux/errno.h>
29#include <linux/string.h>
30#include <linux/stat.h>
31#include <linux/socket.h>
32#include <linux/un.h>
33#include <linux/fcntl.h>
34#include <linux/termios.h>
35#include <linux/sockios.h>
36#include <linux/net.h>
37#include <linux/fs.h>
38#include <linux/slab.h>
39#include <linux/uaccess.h>
40#include <linux/skbuff.h>
41#include <linux/netdevice.h>
42#include <linux/rtnetlink.h>
43#include <linux/proc_fs.h>
44#include <linux/seq_file.h>
45#include <linux/notifier.h>
46#include <linux/security.h>
47#include <linux/jhash.h>
48#include <linux/jiffies.h>
49#include <linux/random.h>
50#include <linux/bitops.h>
51#include <linux/mm.h>
52#include <linux/types.h>
53#include <linux/audit.h>
54#include <linux/mutex.h>
55#include <linux/vmalloc.h>
56#include <linux/if_arp.h>
57#include <linux/rhashtable.h>
58#include <asm/cacheflush.h>
59#include <linux/hash.h>
60#include <linux/genetlink.h>
61#include <linux/net_namespace.h>
62#include <linux/nospec.h>
63#include <linux/btf_ids.h>
64
65#include <net/net_namespace.h>
66#include <net/netns/generic.h>
67#include <net/sock.h>
68#include <net/scm.h>
69#include <net/netlink.h>
70#define CREATE_TRACE_POINTS
71#include <trace/events/netlink.h>
72
73#include "af_netlink.h"
74
75struct listeners {
76 struct rcu_head rcu;
77 unsigned long masks[];
78};
79
80
81#define NETLINK_S_CONGESTED 0x0
82
83static inline int netlink_is_kernel(struct sock *sk)
84{
85 return nlk_sk(sk)->flags & NETLINK_F_KERNEL_SOCKET;
86}
87
88struct netlink_table *nl_table __read_mostly;
89EXPORT_SYMBOL_GPL(nl_table);
90
91static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
92
93static struct lock_class_key nlk_cb_mutex_keys[MAX_LINKS];
94
95static const char *const nlk_cb_mutex_key_strings[MAX_LINKS + 1] = {
96 "nlk_cb_mutex-ROUTE",
97 "nlk_cb_mutex-1",
98 "nlk_cb_mutex-USERSOCK",
99 "nlk_cb_mutex-FIREWALL",
100 "nlk_cb_mutex-SOCK_DIAG",
101 "nlk_cb_mutex-NFLOG",
102 "nlk_cb_mutex-XFRM",
103 "nlk_cb_mutex-SELINUX",
104 "nlk_cb_mutex-ISCSI",
105 "nlk_cb_mutex-AUDIT",
106 "nlk_cb_mutex-FIB_LOOKUP",
107 "nlk_cb_mutex-CONNECTOR",
108 "nlk_cb_mutex-NETFILTER",
109 "nlk_cb_mutex-IP6_FW",
110 "nlk_cb_mutex-DNRTMSG",
111 "nlk_cb_mutex-KOBJECT_UEVENT",
112 "nlk_cb_mutex-GENERIC",
113 "nlk_cb_mutex-17",
114 "nlk_cb_mutex-SCSITRANSPORT",
115 "nlk_cb_mutex-ECRYPTFS",
116 "nlk_cb_mutex-RDMA",
117 "nlk_cb_mutex-CRYPTO",
118 "nlk_cb_mutex-SMC",
119 "nlk_cb_mutex-23",
120 "nlk_cb_mutex-24",
121 "nlk_cb_mutex-25",
122 "nlk_cb_mutex-26",
123 "nlk_cb_mutex-27",
124 "nlk_cb_mutex-28",
125 "nlk_cb_mutex-29",
126 "nlk_cb_mutex-30",
127 "nlk_cb_mutex-31",
128 "nlk_cb_mutex-MAX_LINKS"
129};
130
131static int netlink_dump(struct sock *sk);
132
133
134
135
136
137
138
139
140
141DEFINE_RWLOCK(nl_table_lock);
142EXPORT_SYMBOL_GPL(nl_table_lock);
143static atomic_t nl_table_users = ATOMIC_INIT(0);
144
145#define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock));
146
147static BLOCKING_NOTIFIER_HEAD(netlink_chain);
148
149
150static const struct rhashtable_params netlink_rhashtable_params;
151
152void do_trace_netlink_extack(const char *msg)
153{
154 trace_netlink_extack(msg);
155}
156EXPORT_SYMBOL(do_trace_netlink_extack);
157
158static inline u32 netlink_group_mask(u32 group)
159{
160 return group ? 1 << (group - 1) : 0;
161}
162
163static struct sk_buff *netlink_to_full_skb(const struct sk_buff *skb,
164 gfp_t gfp_mask)
165{
166 unsigned int len = skb_end_offset(skb);
167 struct sk_buff *new;
168
169 new = alloc_skb(len, gfp_mask);
170 if (new == NULL)
171 return NULL;
172
173 NETLINK_CB(new).portid = NETLINK_CB(skb).portid;
174 NETLINK_CB(new).dst_group = NETLINK_CB(skb).dst_group;
175 NETLINK_CB(new).creds = NETLINK_CB(skb).creds;
176
177 skb_put_data(new, skb->data, len);
178 return new;
179}
180
181static unsigned int netlink_tap_net_id;
182
183struct netlink_tap_net {
184 struct list_head netlink_tap_all;
185 struct mutex netlink_tap_lock;
186};
187
188int netlink_add_tap(struct netlink_tap *nt)
189{
190 struct net *net = dev_net(nt->dev);
191 struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
192
193 if (unlikely(nt->dev->type != ARPHRD_NETLINK))
194 return -EINVAL;
195
196 mutex_lock(&nn->netlink_tap_lock);
197 list_add_rcu(&nt->list, &nn->netlink_tap_all);
198 mutex_unlock(&nn->netlink_tap_lock);
199
200 __module_get(nt->module);
201
202 return 0;
203}
204EXPORT_SYMBOL_GPL(netlink_add_tap);
205
206static int __netlink_remove_tap(struct netlink_tap *nt)
207{
208 struct net *net = dev_net(nt->dev);
209 struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
210 bool found = false;
211 struct netlink_tap *tmp;
212
213 mutex_lock(&nn->netlink_tap_lock);
214
215 list_for_each_entry(tmp, &nn->netlink_tap_all, list) {
216 if (nt == tmp) {
217 list_del_rcu(&nt->list);
218 found = true;
219 goto out;
220 }
221 }
222
223 pr_warn("__netlink_remove_tap: %p not found\n", nt);
224out:
225 mutex_unlock(&nn->netlink_tap_lock);
226
227 if (found)
228 module_put(nt->module);
229
230 return found ? 0 : -ENODEV;
231}
232
233int netlink_remove_tap(struct netlink_tap *nt)
234{
235 int ret;
236
237 ret = __netlink_remove_tap(nt);
238 synchronize_net();
239
240 return ret;
241}
242EXPORT_SYMBOL_GPL(netlink_remove_tap);
243
244static __net_init int netlink_tap_init_net(struct net *net)
245{
246 struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
247
248 INIT_LIST_HEAD(&nn->netlink_tap_all);
249 mutex_init(&nn->netlink_tap_lock);
250 return 0;
251}
252
253static struct pernet_operations netlink_tap_net_ops = {
254 .init = netlink_tap_init_net,
255 .id = &netlink_tap_net_id,
256 .size = sizeof(struct netlink_tap_net),
257};
258
259static bool netlink_filter_tap(const struct sk_buff *skb)
260{
261 struct sock *sk = skb->sk;
262
263
264
265
266 switch (sk->sk_protocol) {
267 case NETLINK_ROUTE:
268 case NETLINK_USERSOCK:
269 case NETLINK_SOCK_DIAG:
270 case NETLINK_NFLOG:
271 case NETLINK_XFRM:
272 case NETLINK_FIB_LOOKUP:
273 case NETLINK_NETFILTER:
274 case NETLINK_GENERIC:
275 return true;
276 }
277
278 return false;
279}
280
281static int __netlink_deliver_tap_skb(struct sk_buff *skb,
282 struct net_device *dev)
283{
284 struct sk_buff *nskb;
285 struct sock *sk = skb->sk;
286 int ret = -ENOMEM;
287
288 if (!net_eq(dev_net(dev), sock_net(sk)))
289 return 0;
290
291 dev_hold(dev);
292
293 if (is_vmalloc_addr(skb->head))
294 nskb = netlink_to_full_skb(skb, GFP_ATOMIC);
295 else
296 nskb = skb_clone(skb, GFP_ATOMIC);
297 if (nskb) {
298 nskb->dev = dev;
299 nskb->protocol = htons((u16) sk->sk_protocol);
300 nskb->pkt_type = netlink_is_kernel(sk) ?
301 PACKET_KERNEL : PACKET_USER;
302 skb_reset_network_header(nskb);
303 ret = dev_queue_xmit(nskb);
304 if (unlikely(ret > 0))
305 ret = net_xmit_errno(ret);
306 }
307
308 dev_put(dev);
309 return ret;
310}
311
312static void __netlink_deliver_tap(struct sk_buff *skb, struct netlink_tap_net *nn)
313{
314 int ret;
315 struct netlink_tap *tmp;
316
317 if (!netlink_filter_tap(skb))
318 return;
319
320 list_for_each_entry_rcu(tmp, &nn->netlink_tap_all, list) {
321 ret = __netlink_deliver_tap_skb(skb, tmp->dev);
322 if (unlikely(ret))
323 break;
324 }
325}
326
327static void netlink_deliver_tap(struct net *net, struct sk_buff *skb)
328{
329 struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
330
331 rcu_read_lock();
332
333 if (unlikely(!list_empty(&nn->netlink_tap_all)))
334 __netlink_deliver_tap(skb, nn);
335
336 rcu_read_unlock();
337}
338
339static void netlink_deliver_tap_kernel(struct sock *dst, struct sock *src,
340 struct sk_buff *skb)
341{
342 if (!(netlink_is_kernel(dst) && netlink_is_kernel(src)))
343 netlink_deliver_tap(sock_net(dst), skb);
344}
345
346static void netlink_overrun(struct sock *sk)
347{
348 struct netlink_sock *nlk = nlk_sk(sk);
349
350 if (!(nlk->flags & NETLINK_F_RECV_NO_ENOBUFS)) {
351 if (!test_and_set_bit(NETLINK_S_CONGESTED,
352 &nlk_sk(sk)->state)) {
353 sk->sk_err = ENOBUFS;
354 sk_error_report(sk);
355 }
356 }
357 atomic_inc(&sk->sk_drops);
358}
359
360static void netlink_rcv_wake(struct sock *sk)
361{
362 struct netlink_sock *nlk = nlk_sk(sk);
363
364 if (skb_queue_empty_lockless(&sk->sk_receive_queue))
365 clear_bit(NETLINK_S_CONGESTED, &nlk->state);
366 if (!test_bit(NETLINK_S_CONGESTED, &nlk->state))
367 wake_up_interruptible(&nlk->wait);
368}
369
370static void netlink_skb_destructor(struct sk_buff *skb)
371{
372 if (is_vmalloc_addr(skb->head)) {
373 if (!skb->cloned ||
374 !atomic_dec_return(&(skb_shinfo(skb)->dataref)))
375 vfree(skb->head);
376
377 skb->head = NULL;
378 }
379 if (skb->sk != NULL)
380 sock_rfree(skb);
381}
382
383static void netlink_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
384{
385 WARN_ON(skb->sk != NULL);
386 skb->sk = sk;
387 skb->destructor = netlink_skb_destructor;
388 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
389 sk_mem_charge(sk, skb->truesize);
390}
391
392static void netlink_sock_destruct(struct sock *sk)
393{
394 struct netlink_sock *nlk = nlk_sk(sk);
395
396 if (nlk->cb_running) {
397 if (nlk->cb.done)
398 nlk->cb.done(&nlk->cb);
399 module_put(nlk->cb.module);
400 kfree_skb(nlk->cb.skb);
401 }
402
403 skb_queue_purge(&sk->sk_receive_queue);
404
405 if (!sock_flag(sk, SOCK_DEAD)) {
406 printk(KERN_ERR "Freeing alive netlink socket %p\n", sk);
407 return;
408 }
409
410 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
411 WARN_ON(refcount_read(&sk->sk_wmem_alloc));
412 WARN_ON(nlk_sk(sk)->groups);
413}
414
415static void netlink_sock_destruct_work(struct work_struct *work)
416{
417 struct netlink_sock *nlk = container_of(work, struct netlink_sock,
418 work);
419
420 sk_free(&nlk->sk);
421}
422
423
424
425
426
427
428
429void netlink_table_grab(void)
430 __acquires(nl_table_lock)
431{
432 might_sleep();
433
434 write_lock_irq(&nl_table_lock);
435
436 if (atomic_read(&nl_table_users)) {
437 DECLARE_WAITQUEUE(wait, current);
438
439 add_wait_queue_exclusive(&nl_table_wait, &wait);
440 for (;;) {
441 set_current_state(TASK_UNINTERRUPTIBLE);
442 if (atomic_read(&nl_table_users) == 0)
443 break;
444 write_unlock_irq(&nl_table_lock);
445 schedule();
446 write_lock_irq(&nl_table_lock);
447 }
448
449 __set_current_state(TASK_RUNNING);
450 remove_wait_queue(&nl_table_wait, &wait);
451 }
452}
453
454void netlink_table_ungrab(void)
455 __releases(nl_table_lock)
456{
457 write_unlock_irq(&nl_table_lock);
458 wake_up(&nl_table_wait);
459}
460
461static inline void
462netlink_lock_table(void)
463{
464 unsigned long flags;
465
466
467
468 read_lock_irqsave(&nl_table_lock, flags);
469 atomic_inc(&nl_table_users);
470 read_unlock_irqrestore(&nl_table_lock, flags);
471}
472
473static inline void
474netlink_unlock_table(void)
475{
476 if (atomic_dec_and_test(&nl_table_users))
477 wake_up(&nl_table_wait);
478}
479
480struct netlink_compare_arg
481{
482 possible_net_t pnet;
483 u32 portid;
484};
485
486
487#define netlink_compare_arg_len \
488 (offsetof(struct netlink_compare_arg, portid) + sizeof(u32))
489
490static inline int netlink_compare(struct rhashtable_compare_arg *arg,
491 const void *ptr)
492{
493 const struct netlink_compare_arg *x = arg->key;
494 const struct netlink_sock *nlk = ptr;
495
496 return nlk->portid != x->portid ||
497 !net_eq(sock_net(&nlk->sk), read_pnet(&x->pnet));
498}
499
500static void netlink_compare_arg_init(struct netlink_compare_arg *arg,
501 struct net *net, u32 portid)
502{
503 memset(arg, 0, sizeof(*arg));
504 write_pnet(&arg->pnet, net);
505 arg->portid = portid;
506}
507
508static struct sock *__netlink_lookup(struct netlink_table *table, u32 portid,
509 struct net *net)
510{
511 struct netlink_compare_arg arg;
512
513 netlink_compare_arg_init(&arg, net, portid);
514 return rhashtable_lookup_fast(&table->hash, &arg,
515 netlink_rhashtable_params);
516}
517
518static int __netlink_insert(struct netlink_table *table, struct sock *sk)
519{
520 struct netlink_compare_arg arg;
521
522 netlink_compare_arg_init(&arg, sock_net(sk), nlk_sk(sk)->portid);
523 return rhashtable_lookup_insert_key(&table->hash, &arg,
524 &nlk_sk(sk)->node,
525 netlink_rhashtable_params);
526}
527
528static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid)
529{
530 struct netlink_table *table = &nl_table[protocol];
531 struct sock *sk;
532
533 rcu_read_lock();
534 sk = __netlink_lookup(table, portid, net);
535 if (sk)
536 sock_hold(sk);
537 rcu_read_unlock();
538
539 return sk;
540}
541
542static const struct proto_ops netlink_ops;
543
544static void
545netlink_update_listeners(struct sock *sk)
546{
547 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
548 unsigned long mask;
549 unsigned int i;
550 struct listeners *listeners;
551
552 listeners = nl_deref_protected(tbl->listeners);
553 if (!listeners)
554 return;
555
556 for (i = 0; i < NLGRPLONGS(tbl->groups); i++) {
557 mask = 0;
558 sk_for_each_bound(sk, &tbl->mc_list) {
559 if (i < NLGRPLONGS(nlk_sk(sk)->ngroups))
560 mask |= nlk_sk(sk)->groups[i];
561 }
562 listeners->masks[i] = mask;
563 }
564
565
566}
567
568static int netlink_insert(struct sock *sk, u32 portid)
569{
570 struct netlink_table *table = &nl_table[sk->sk_protocol];
571 int err;
572
573 lock_sock(sk);
574
575 err = nlk_sk(sk)->portid == portid ? 0 : -EBUSY;
576 if (nlk_sk(sk)->bound)
577 goto err;
578
579 nlk_sk(sk)->portid = portid;
580 sock_hold(sk);
581
582 err = __netlink_insert(table, sk);
583 if (err) {
584
585
586
587 if (unlikely(err == -EBUSY))
588 err = -EOVERFLOW;
589 if (err == -EEXIST)
590 err = -EADDRINUSE;
591 sock_put(sk);
592 goto err;
593 }
594
595
596 smp_wmb();
597 nlk_sk(sk)->bound = portid;
598
599err:
600 release_sock(sk);
601 return err;
602}
603
604static void netlink_remove(struct sock *sk)
605{
606 struct netlink_table *table;
607
608 table = &nl_table[sk->sk_protocol];
609 if (!rhashtable_remove_fast(&table->hash, &nlk_sk(sk)->node,
610 netlink_rhashtable_params)) {
611 WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
612 __sock_put(sk);
613 }
614
615 netlink_table_grab();
616 if (nlk_sk(sk)->subscriptions) {
617 __sk_del_bind_node(sk);
618 netlink_update_listeners(sk);
619 }
620 if (sk->sk_protocol == NETLINK_GENERIC)
621 atomic_inc(&genl_sk_destructing_cnt);
622 netlink_table_ungrab();
623}
624
625static struct proto netlink_proto = {
626 .name = "NETLINK",
627 .owner = THIS_MODULE,
628 .obj_size = sizeof(struct netlink_sock),
629};
630
631static int __netlink_create(struct net *net, struct socket *sock,
632 struct mutex *cb_mutex, int protocol,
633 int kern)
634{
635 struct sock *sk;
636 struct netlink_sock *nlk;
637
638 sock->ops = &netlink_ops;
639
640 sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto, kern);
641 if (!sk)
642 return -ENOMEM;
643
644 sock_init_data(sock, sk);
645
646 nlk = nlk_sk(sk);
647 if (cb_mutex) {
648 nlk->cb_mutex = cb_mutex;
649 } else {
650 nlk->cb_mutex = &nlk->cb_def_mutex;
651 mutex_init(nlk->cb_mutex);
652 lockdep_set_class_and_name(nlk->cb_mutex,
653 nlk_cb_mutex_keys + protocol,
654 nlk_cb_mutex_key_strings[protocol]);
655 }
656 init_waitqueue_head(&nlk->wait);
657
658 sk->sk_destruct = netlink_sock_destruct;
659 sk->sk_protocol = protocol;
660 return 0;
661}
662
663static int netlink_create(struct net *net, struct socket *sock, int protocol,
664 int kern)
665{
666 struct module *module = NULL;
667 struct mutex *cb_mutex;
668 struct netlink_sock *nlk;
669 int (*bind)(struct net *net, int group);
670 void (*unbind)(struct net *net, int group);
671 int err = 0;
672
673 sock->state = SS_UNCONNECTED;
674
675 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
676 return -ESOCKTNOSUPPORT;
677
678 if (protocol < 0 || protocol >= MAX_LINKS)
679 return -EPROTONOSUPPORT;
680 protocol = array_index_nospec(protocol, MAX_LINKS);
681
682 netlink_lock_table();
683#ifdef CONFIG_MODULES
684 if (!nl_table[protocol].registered) {
685 netlink_unlock_table();
686 request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
687 netlink_lock_table();
688 }
689#endif
690 if (nl_table[protocol].registered &&
691 try_module_get(nl_table[protocol].module))
692 module = nl_table[protocol].module;
693 else
694 err = -EPROTONOSUPPORT;
695 cb_mutex = nl_table[protocol].cb_mutex;
696 bind = nl_table[protocol].bind;
697 unbind = nl_table[protocol].unbind;
698 netlink_unlock_table();
699
700 if (err < 0)
701 goto out;
702
703 err = __netlink_create(net, sock, cb_mutex, protocol, kern);
704 if (err < 0)
705 goto out_module;
706
707 local_bh_disable();
708 sock_prot_inuse_add(net, &netlink_proto, 1);
709 local_bh_enable();
710
711 nlk = nlk_sk(sock->sk);
712 nlk->module = module;
713 nlk->netlink_bind = bind;
714 nlk->netlink_unbind = unbind;
715out:
716 return err;
717
718out_module:
719 module_put(module);
720 goto out;
721}
722
723static void deferred_put_nlk_sk(struct rcu_head *head)
724{
725 struct netlink_sock *nlk = container_of(head, struct netlink_sock, rcu);
726 struct sock *sk = &nlk->sk;
727
728 kfree(nlk->groups);
729 nlk->groups = NULL;
730
731 if (!refcount_dec_and_test(&sk->sk_refcnt))
732 return;
733
734 if (nlk->cb_running && nlk->cb.done) {
735 INIT_WORK(&nlk->work, netlink_sock_destruct_work);
736 schedule_work(&nlk->work);
737 return;
738 }
739
740 sk_free(sk);
741}
742
743static int netlink_release(struct socket *sock)
744{
745 struct sock *sk = sock->sk;
746 struct netlink_sock *nlk;
747
748 if (!sk)
749 return 0;
750
751 netlink_remove(sk);
752 sock_orphan(sk);
753 nlk = nlk_sk(sk);
754
755
756
757
758
759
760
761
762
763 if (nlk->netlink_unbind) {
764 int i;
765
766 for (i = 0; i < nlk->ngroups; i++)
767 if (test_bit(i, nlk->groups))
768 nlk->netlink_unbind(sock_net(sk), i + 1);
769 }
770 if (sk->sk_protocol == NETLINK_GENERIC &&
771 atomic_dec_return(&genl_sk_destructing_cnt) == 0)
772 wake_up(&genl_sk_destructing_waitq);
773
774 sock->sk = NULL;
775 wake_up_interruptible_all(&nlk->wait);
776
777 skb_queue_purge(&sk->sk_write_queue);
778
779 if (nlk->portid && nlk->bound) {
780 struct netlink_notify n = {
781 .net = sock_net(sk),
782 .protocol = sk->sk_protocol,
783 .portid = nlk->portid,
784 };
785 blocking_notifier_call_chain(&netlink_chain,
786 NETLINK_URELEASE, &n);
787 }
788
789 module_put(nlk->module);
790
791 if (netlink_is_kernel(sk)) {
792 netlink_table_grab();
793 BUG_ON(nl_table[sk->sk_protocol].registered == 0);
794 if (--nl_table[sk->sk_protocol].registered == 0) {
795 struct listeners *old;
796
797 old = nl_deref_protected(nl_table[sk->sk_protocol].listeners);
798 RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL);
799 kfree_rcu(old, rcu);
800 nl_table[sk->sk_protocol].module = NULL;
801 nl_table[sk->sk_protocol].bind = NULL;
802 nl_table[sk->sk_protocol].unbind = NULL;
803 nl_table[sk->sk_protocol].flags = 0;
804 nl_table[sk->sk_protocol].registered = 0;
805 }
806 netlink_table_ungrab();
807 }
808
809 local_bh_disable();
810 sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1);
811 local_bh_enable();
812 call_rcu(&nlk->rcu, deferred_put_nlk_sk);
813 return 0;
814}
815
816static int netlink_autobind(struct socket *sock)
817{
818 struct sock *sk = sock->sk;
819 struct net *net = sock_net(sk);
820 struct netlink_table *table = &nl_table[sk->sk_protocol];
821 s32 portid = task_tgid_vnr(current);
822 int err;
823 s32 rover = -4096;
824 bool ok;
825
826retry:
827 cond_resched();
828 rcu_read_lock();
829 ok = !__netlink_lookup(table, portid, net);
830 rcu_read_unlock();
831 if (!ok) {
832
833 if (rover == -4096)
834
835 rover = S32_MIN + prandom_u32_max(-4096 - S32_MIN);
836 else if (rover >= -4096)
837 rover = -4097;
838 portid = rover--;
839 goto retry;
840 }
841
842 err = netlink_insert(sk, portid);
843 if (err == -EADDRINUSE)
844 goto retry;
845
846
847 if (err == -EBUSY)
848 err = 0;
849
850 return err;
851}
852
853
854
855
856
857
858
859
860
861
862
863bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
864 struct user_namespace *user_ns, int cap)
865{
866 return ((nsp->flags & NETLINK_SKB_DST) ||
867 file_ns_capable(nsp->sk->sk_socket->file, user_ns, cap)) &&
868 ns_capable(user_ns, cap);
869}
870EXPORT_SYMBOL(__netlink_ns_capable);
871
872
873
874
875
876
877
878
879
880
881
882bool netlink_ns_capable(const struct sk_buff *skb,
883 struct user_namespace *user_ns, int cap)
884{
885 return __netlink_ns_capable(&NETLINK_CB(skb), user_ns, cap);
886}
887EXPORT_SYMBOL(netlink_ns_capable);
888
889
890
891
892
893
894
895
896
897
898bool netlink_capable(const struct sk_buff *skb, int cap)
899{
900 return netlink_ns_capable(skb, &init_user_ns, cap);
901}
902EXPORT_SYMBOL(netlink_capable);
903
904
905
906
907
908
909
910
911
912
913
914bool netlink_net_capable(const struct sk_buff *skb, int cap)
915{
916 return netlink_ns_capable(skb, sock_net(skb->sk)->user_ns, cap);
917}
918EXPORT_SYMBOL(netlink_net_capable);
919
920static inline int netlink_allowed(const struct socket *sock, unsigned int flag)
921{
922 return (nl_table[sock->sk->sk_protocol].flags & flag) ||
923 ns_capable(sock_net(sock->sk)->user_ns, CAP_NET_ADMIN);
924}
925
926static void
927netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions)
928{
929 struct netlink_sock *nlk = nlk_sk(sk);
930
931 if (nlk->subscriptions && !subscriptions)
932 __sk_del_bind_node(sk);
933 else if (!nlk->subscriptions && subscriptions)
934 sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
935 nlk->subscriptions = subscriptions;
936}
937
938static int netlink_realloc_groups(struct sock *sk)
939{
940 struct netlink_sock *nlk = nlk_sk(sk);
941 unsigned int groups;
942 unsigned long *new_groups;
943 int err = 0;
944
945 netlink_table_grab();
946
947 groups = nl_table[sk->sk_protocol].groups;
948 if (!nl_table[sk->sk_protocol].registered) {
949 err = -ENOENT;
950 goto out_unlock;
951 }
952
953 if (nlk->ngroups >= groups)
954 goto out_unlock;
955
956 new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC);
957 if (new_groups == NULL) {
958 err = -ENOMEM;
959 goto out_unlock;
960 }
961 memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0,
962 NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups));
963
964 nlk->groups = new_groups;
965 nlk->ngroups = groups;
966 out_unlock:
967 netlink_table_ungrab();
968 return err;
969}
970
971static void netlink_undo_bind(int group, long unsigned int groups,
972 struct sock *sk)
973{
974 struct netlink_sock *nlk = nlk_sk(sk);
975 int undo;
976
977 if (!nlk->netlink_unbind)
978 return;
979
980 for (undo = 0; undo < group; undo++)
981 if (test_bit(undo, &groups))
982 nlk->netlink_unbind(sock_net(sk), undo + 1);
983}
984
985static int netlink_bind(struct socket *sock, struct sockaddr *addr,
986 int addr_len)
987{
988 struct sock *sk = sock->sk;
989 struct net *net = sock_net(sk);
990 struct netlink_sock *nlk = nlk_sk(sk);
991 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
992 int err = 0;
993 unsigned long groups;
994 bool bound;
995
996 if (addr_len < sizeof(struct sockaddr_nl))
997 return -EINVAL;
998
999 if (nladdr->nl_family != AF_NETLINK)
1000 return -EINVAL;
1001 groups = nladdr->nl_groups;
1002
1003
1004 if (groups) {
1005 if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV))
1006 return -EPERM;
1007 err = netlink_realloc_groups(sk);
1008 if (err)
1009 return err;
1010 }
1011
1012 if (nlk->ngroups < BITS_PER_LONG)
1013 groups &= (1UL << nlk->ngroups) - 1;
1014
1015 bound = nlk->bound;
1016 if (bound) {
1017
1018 smp_rmb();
1019
1020 if (nladdr->nl_pid != nlk->portid)
1021 return -EINVAL;
1022 }
1023
1024 if (nlk->netlink_bind && groups) {
1025 int group;
1026
1027
1028 for (group = 0; group < BITS_PER_TYPE(u32); group++) {
1029 if (!test_bit(group, &groups))
1030 continue;
1031 err = nlk->netlink_bind(net, group + 1);
1032 if (!err)
1033 continue;
1034 netlink_undo_bind(group, groups, sk);
1035 return err;
1036 }
1037 }
1038
1039
1040
1041
1042 netlink_lock_table();
1043 if (!bound) {
1044 err = nladdr->nl_pid ?
1045 netlink_insert(sk, nladdr->nl_pid) :
1046 netlink_autobind(sock);
1047 if (err) {
1048 netlink_undo_bind(BITS_PER_TYPE(u32), groups, sk);
1049 goto unlock;
1050 }
1051 }
1052
1053 if (!groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
1054 goto unlock;
1055 netlink_unlock_table();
1056
1057 netlink_table_grab();
1058 netlink_update_subscriptions(sk, nlk->subscriptions +
1059 hweight32(groups) -
1060 hweight32(nlk->groups[0]));
1061 nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | groups;
1062 netlink_update_listeners(sk);
1063 netlink_table_ungrab();
1064
1065 return 0;
1066
1067unlock:
1068 netlink_unlock_table();
1069 return err;
1070}
1071
1072static int netlink_connect(struct socket *sock, struct sockaddr *addr,
1073 int alen, int flags)
1074{
1075 int err = 0;
1076 struct sock *sk = sock->sk;
1077 struct netlink_sock *nlk = nlk_sk(sk);
1078 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
1079
1080 if (alen < sizeof(addr->sa_family))
1081 return -EINVAL;
1082
1083 if (addr->sa_family == AF_UNSPEC) {
1084 sk->sk_state = NETLINK_UNCONNECTED;
1085 nlk->dst_portid = 0;
1086 nlk->dst_group = 0;
1087 return 0;
1088 }
1089 if (addr->sa_family != AF_NETLINK)
1090 return -EINVAL;
1091
1092 if (alen < sizeof(struct sockaddr_nl))
1093 return -EINVAL;
1094
1095 if ((nladdr->nl_groups || nladdr->nl_pid) &&
1096 !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
1097 return -EPERM;
1098
1099
1100
1101
1102 if (!nlk->bound)
1103 err = netlink_autobind(sock);
1104
1105 if (err == 0) {
1106 sk->sk_state = NETLINK_CONNECTED;
1107 nlk->dst_portid = nladdr->nl_pid;
1108 nlk->dst_group = ffs(nladdr->nl_groups);
1109 }
1110
1111 return err;
1112}
1113
1114static int netlink_getname(struct socket *sock, struct sockaddr *addr,
1115 int peer)
1116{
1117 struct sock *sk = sock->sk;
1118 struct netlink_sock *nlk = nlk_sk(sk);
1119 DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr);
1120
1121 nladdr->nl_family = AF_NETLINK;
1122 nladdr->nl_pad = 0;
1123
1124 if (peer) {
1125 nladdr->nl_pid = nlk->dst_portid;
1126 nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
1127 } else {
1128 nladdr->nl_pid = nlk->portid;
1129 netlink_lock_table();
1130 nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
1131 netlink_unlock_table();
1132 }
1133 return sizeof(*nladdr);
1134}
1135
1136static int netlink_ioctl(struct socket *sock, unsigned int cmd,
1137 unsigned long arg)
1138{
1139
1140
1141 return -ENOIOCTLCMD;
1142}
1143
1144static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid)
1145{
1146 struct sock *sock;
1147 struct netlink_sock *nlk;
1148
1149 sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, portid);
1150 if (!sock)
1151 return ERR_PTR(-ECONNREFUSED);
1152
1153
1154 nlk = nlk_sk(sock);
1155 if (sock->sk_state == NETLINK_CONNECTED &&
1156 nlk->dst_portid != nlk_sk(ssk)->portid) {
1157 sock_put(sock);
1158 return ERR_PTR(-ECONNREFUSED);
1159 }
1160 return sock;
1161}
1162
1163struct sock *netlink_getsockbyfilp(struct file *filp)
1164{
1165 struct inode *inode = file_inode(filp);
1166 struct sock *sock;
1167
1168 if (!S_ISSOCK(inode->i_mode))
1169 return ERR_PTR(-ENOTSOCK);
1170
1171 sock = SOCKET_I(inode)->sk;
1172 if (sock->sk_family != AF_NETLINK)
1173 return ERR_PTR(-EINVAL);
1174
1175 sock_hold(sock);
1176 return sock;
1177}
1178
1179static struct sk_buff *netlink_alloc_large_skb(unsigned int size,
1180 int broadcast)
1181{
1182 struct sk_buff *skb;
1183 void *data;
1184
1185 if (size <= NLMSG_GOODSIZE || broadcast)
1186 return alloc_skb(size, GFP_KERNEL);
1187
1188 size = SKB_DATA_ALIGN(size) +
1189 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1190
1191 data = vmalloc(size);
1192 if (data == NULL)
1193 return NULL;
1194
1195 skb = __build_skb(data, size);
1196 if (skb == NULL)
1197 vfree(data);
1198 else
1199 skb->destructor = netlink_skb_destructor;
1200
1201 return skb;
1202}
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
1215 long *timeo, struct sock *ssk)
1216{
1217 struct netlink_sock *nlk;
1218
1219 nlk = nlk_sk(sk);
1220
1221 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
1222 test_bit(NETLINK_S_CONGESTED, &nlk->state))) {
1223 DECLARE_WAITQUEUE(wait, current);
1224 if (!*timeo) {
1225 if (!ssk || netlink_is_kernel(ssk))
1226 netlink_overrun(sk);
1227 sock_put(sk);
1228 kfree_skb(skb);
1229 return -EAGAIN;
1230 }
1231
1232 __set_current_state(TASK_INTERRUPTIBLE);
1233 add_wait_queue(&nlk->wait, &wait);
1234
1235 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
1236 test_bit(NETLINK_S_CONGESTED, &nlk->state)) &&
1237 !sock_flag(sk, SOCK_DEAD))
1238 *timeo = schedule_timeout(*timeo);
1239
1240 __set_current_state(TASK_RUNNING);
1241 remove_wait_queue(&nlk->wait, &wait);
1242 sock_put(sk);
1243
1244 if (signal_pending(current)) {
1245 kfree_skb(skb);
1246 return sock_intr_errno(*timeo);
1247 }
1248 return 1;
1249 }
1250 netlink_skb_set_owner_r(skb, sk);
1251 return 0;
1252}
1253
1254static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb)
1255{
1256 int len = skb->len;
1257
1258 netlink_deliver_tap(sock_net(sk), skb);
1259
1260 skb_queue_tail(&sk->sk_receive_queue, skb);
1261 sk->sk_data_ready(sk);
1262 return len;
1263}
1264
1265int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
1266{
1267 int len = __netlink_sendskb(sk, skb);
1268
1269 sock_put(sk);
1270 return len;
1271}
1272
1273void netlink_detachskb(struct sock *sk, struct sk_buff *skb)
1274{
1275 kfree_skb(skb);
1276 sock_put(sk);
1277}
1278
1279static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation)
1280{
1281 int delta;
1282
1283 WARN_ON(skb->sk != NULL);
1284 delta = skb->end - skb->tail;
1285 if (is_vmalloc_addr(skb->head) || delta * 2 < skb->truesize)
1286 return skb;
1287
1288 if (skb_shared(skb)) {
1289 struct sk_buff *nskb = skb_clone(skb, allocation);
1290 if (!nskb)
1291 return skb;
1292 consume_skb(skb);
1293 skb = nskb;
1294 }
1295
1296 pskb_expand_head(skb, 0, -delta,
1297 (allocation & ~__GFP_DIRECT_RECLAIM) |
1298 __GFP_NOWARN | __GFP_NORETRY);
1299 return skb;
1300}
1301
1302static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb,
1303 struct sock *ssk)
1304{
1305 int ret;
1306 struct netlink_sock *nlk = nlk_sk(sk);
1307
1308 ret = -ECONNREFUSED;
1309 if (nlk->netlink_rcv != NULL) {
1310 ret = skb->len;
1311 netlink_skb_set_owner_r(skb, sk);
1312 NETLINK_CB(skb).sk = ssk;
1313 netlink_deliver_tap_kernel(sk, ssk, skb);
1314 nlk->netlink_rcv(skb);
1315 consume_skb(skb);
1316 } else {
1317 kfree_skb(skb);
1318 }
1319 sock_put(sk);
1320 return ret;
1321}
1322
1323int netlink_unicast(struct sock *ssk, struct sk_buff *skb,
1324 u32 portid, int nonblock)
1325{
1326 struct sock *sk;
1327 int err;
1328 long timeo;
1329
1330 skb = netlink_trim(skb, gfp_any());
1331
1332 timeo = sock_sndtimeo(ssk, nonblock);
1333retry:
1334 sk = netlink_getsockbyportid(ssk, portid);
1335 if (IS_ERR(sk)) {
1336 kfree_skb(skb);
1337 return PTR_ERR(sk);
1338 }
1339 if (netlink_is_kernel(sk))
1340 return netlink_unicast_kernel(sk, skb, ssk);
1341
1342 if (sk_filter(sk, skb)) {
1343 err = skb->len;
1344 kfree_skb(skb);
1345 sock_put(sk);
1346 return err;
1347 }
1348
1349 err = netlink_attachskb(sk, skb, &timeo, ssk);
1350 if (err == 1)
1351 goto retry;
1352 if (err)
1353 return err;
1354
1355 return netlink_sendskb(sk, skb);
1356}
1357EXPORT_SYMBOL(netlink_unicast);
1358
1359int netlink_has_listeners(struct sock *sk, unsigned int group)
1360{
1361 int res = 0;
1362 struct listeners *listeners;
1363
1364 BUG_ON(!netlink_is_kernel(sk));
1365
1366 rcu_read_lock();
1367 listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners);
1368
1369 if (listeners && group - 1 < nl_table[sk->sk_protocol].groups)
1370 res = test_bit(group - 1, listeners->masks);
1371
1372 rcu_read_unlock();
1373
1374 return res;
1375}
1376EXPORT_SYMBOL_GPL(netlink_has_listeners);
1377
1378bool netlink_strict_get_check(struct sk_buff *skb)
1379{
1380 const struct netlink_sock *nlk = nlk_sk(NETLINK_CB(skb).sk);
1381
1382 return nlk->flags & NETLINK_F_STRICT_CHK;
1383}
1384EXPORT_SYMBOL_GPL(netlink_strict_get_check);
1385
1386static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb)
1387{
1388 struct netlink_sock *nlk = nlk_sk(sk);
1389
1390 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
1391 !test_bit(NETLINK_S_CONGESTED, &nlk->state)) {
1392 netlink_skb_set_owner_r(skb, sk);
1393 __netlink_sendskb(sk, skb);
1394 return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1);
1395 }
1396 return -1;
1397}
1398
1399struct netlink_broadcast_data {
1400 struct sock *exclude_sk;
1401 struct net *net;
1402 u32 portid;
1403 u32 group;
1404 int failure;
1405 int delivery_failure;
1406 int congested;
1407 int delivered;
1408 gfp_t allocation;
1409 struct sk_buff *skb, *skb2;
1410 int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data);
1411 void *tx_data;
1412};
1413
1414static void do_one_broadcast(struct sock *sk,
1415 struct netlink_broadcast_data *p)
1416{
1417 struct netlink_sock *nlk = nlk_sk(sk);
1418 int val;
1419
1420 if (p->exclude_sk == sk)
1421 return;
1422
1423 if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups ||
1424 !test_bit(p->group - 1, nlk->groups))
1425 return;
1426
1427 if (!net_eq(sock_net(sk), p->net)) {
1428 if (!(nlk->flags & NETLINK_F_LISTEN_ALL_NSID))
1429 return;
1430
1431 if (!peernet_has_id(sock_net(sk), p->net))
1432 return;
1433
1434 if (!file_ns_capable(sk->sk_socket->file, p->net->user_ns,
1435 CAP_NET_BROADCAST))
1436 return;
1437 }
1438
1439 if (p->failure) {
1440 netlink_overrun(sk);
1441 return;
1442 }
1443
1444 sock_hold(sk);
1445 if (p->skb2 == NULL) {
1446 if (skb_shared(p->skb)) {
1447 p->skb2 = skb_clone(p->skb, p->allocation);
1448 } else {
1449 p->skb2 = skb_get(p->skb);
1450
1451
1452
1453
1454 skb_orphan(p->skb2);
1455 }
1456 }
1457 if (p->skb2 == NULL) {
1458 netlink_overrun(sk);
1459
1460 p->failure = 1;
1461 if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR)
1462 p->delivery_failure = 1;
1463 goto out;
1464 }
1465 if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) {
1466 kfree_skb(p->skb2);
1467 p->skb2 = NULL;
1468 goto out;
1469 }
1470 if (sk_filter(sk, p->skb2)) {
1471 kfree_skb(p->skb2);
1472 p->skb2 = NULL;
1473 goto out;
1474 }
1475 NETLINK_CB(p->skb2).nsid = peernet2id(sock_net(sk), p->net);
1476 if (NETLINK_CB(p->skb2).nsid != NETNSA_NSID_NOT_ASSIGNED)
1477 NETLINK_CB(p->skb2).nsid_is_set = true;
1478 val = netlink_broadcast_deliver(sk, p->skb2);
1479 if (val < 0) {
1480 netlink_overrun(sk);
1481 if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR)
1482 p->delivery_failure = 1;
1483 } else {
1484 p->congested |= val;
1485 p->delivered = 1;
1486 p->skb2 = NULL;
1487 }
1488out:
1489 sock_put(sk);
1490}
1491
1492int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 portid,
1493 u32 group, gfp_t allocation,
1494 int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
1495 void *filter_data)
1496{
1497 struct net *net = sock_net(ssk);
1498 struct netlink_broadcast_data info;
1499 struct sock *sk;
1500
1501 skb = netlink_trim(skb, allocation);
1502
1503 info.exclude_sk = ssk;
1504 info.net = net;
1505 info.portid = portid;
1506 info.group = group;
1507 info.failure = 0;
1508 info.delivery_failure = 0;
1509 info.congested = 0;
1510 info.delivered = 0;
1511 info.allocation = allocation;
1512 info.skb = skb;
1513 info.skb2 = NULL;
1514 info.tx_filter = filter;
1515 info.tx_data = filter_data;
1516
1517
1518
1519 netlink_lock_table();
1520
1521 sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list)
1522 do_one_broadcast(sk, &info);
1523
1524 consume_skb(skb);
1525
1526 netlink_unlock_table();
1527
1528 if (info.delivery_failure) {
1529 kfree_skb(info.skb2);
1530 return -ENOBUFS;
1531 }
1532 consume_skb(info.skb2);
1533
1534 if (info.delivered) {
1535 if (info.congested && gfpflags_allow_blocking(allocation))
1536 yield();
1537 return 0;
1538 }
1539 return -ESRCH;
1540}
1541EXPORT_SYMBOL(netlink_broadcast_filtered);
1542
1543int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 portid,
1544 u32 group, gfp_t allocation)
1545{
1546 return netlink_broadcast_filtered(ssk, skb, portid, group, allocation,
1547 NULL, NULL);
1548}
1549EXPORT_SYMBOL(netlink_broadcast);
1550
1551struct netlink_set_err_data {
1552 struct sock *exclude_sk;
1553 u32 portid;
1554 u32 group;
1555 int code;
1556};
1557
1558static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p)
1559{
1560 struct netlink_sock *nlk = nlk_sk(sk);
1561 int ret = 0;
1562
1563 if (sk == p->exclude_sk)
1564 goto out;
1565
1566 if (!net_eq(sock_net(sk), sock_net(p->exclude_sk)))
1567 goto out;
1568
1569 if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups ||
1570 !test_bit(p->group - 1, nlk->groups))
1571 goto out;
1572
1573 if (p->code == ENOBUFS && nlk->flags & NETLINK_F_RECV_NO_ENOBUFS) {
1574 ret = 1;
1575 goto out;
1576 }
1577
1578 sk->sk_err = p->code;
1579 sk_error_report(sk);
1580out:
1581 return ret;
1582}
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code)
1595{
1596 struct netlink_set_err_data info;
1597 struct sock *sk;
1598 int ret = 0;
1599
1600 info.exclude_sk = ssk;
1601 info.portid = portid;
1602 info.group = group;
1603
1604 info.code = -code;
1605
1606 read_lock(&nl_table_lock);
1607
1608 sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list)
1609 ret += do_one_set_err(sk, &info);
1610
1611 read_unlock(&nl_table_lock);
1612 return ret;
1613}
1614EXPORT_SYMBOL(netlink_set_err);
1615
1616
1617static void netlink_update_socket_mc(struct netlink_sock *nlk,
1618 unsigned int group,
1619 int is_new)
1620{
1621 int old, new = !!is_new, subscriptions;
1622
1623 old = test_bit(group - 1, nlk->groups);
1624 subscriptions = nlk->subscriptions - old + new;
1625 if (new)
1626 __set_bit(group - 1, nlk->groups);
1627 else
1628 __clear_bit(group - 1, nlk->groups);
1629 netlink_update_subscriptions(&nlk->sk, subscriptions);
1630 netlink_update_listeners(&nlk->sk);
1631}
1632
1633static int netlink_setsockopt(struct socket *sock, int level, int optname,
1634 sockptr_t optval, unsigned int optlen)
1635{
1636 struct sock *sk = sock->sk;
1637 struct netlink_sock *nlk = nlk_sk(sk);
1638 unsigned int val = 0;
1639 int err;
1640
1641 if (level != SOL_NETLINK)
1642 return -ENOPROTOOPT;
1643
1644 if (optlen >= sizeof(int) &&
1645 copy_from_sockptr(&val, optval, sizeof(val)))
1646 return -EFAULT;
1647
1648 switch (optname) {
1649 case NETLINK_PKTINFO:
1650 if (val)
1651 nlk->flags |= NETLINK_F_RECV_PKTINFO;
1652 else
1653 nlk->flags &= ~NETLINK_F_RECV_PKTINFO;
1654 err = 0;
1655 break;
1656 case NETLINK_ADD_MEMBERSHIP:
1657 case NETLINK_DROP_MEMBERSHIP: {
1658 if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV))
1659 return -EPERM;
1660 err = netlink_realloc_groups(sk);
1661 if (err)
1662 return err;
1663 if (!val || val - 1 >= nlk->ngroups)
1664 return -EINVAL;
1665 if (optname == NETLINK_ADD_MEMBERSHIP && nlk->netlink_bind) {
1666 err = nlk->netlink_bind(sock_net(sk), val);
1667 if (err)
1668 return err;
1669 }
1670 netlink_table_grab();
1671 netlink_update_socket_mc(nlk, val,
1672 optname == NETLINK_ADD_MEMBERSHIP);
1673 netlink_table_ungrab();
1674 if (optname == NETLINK_DROP_MEMBERSHIP && nlk->netlink_unbind)
1675 nlk->netlink_unbind(sock_net(sk), val);
1676
1677 err = 0;
1678 break;
1679 }
1680 case NETLINK_BROADCAST_ERROR:
1681 if (val)
1682 nlk->flags |= NETLINK_F_BROADCAST_SEND_ERROR;
1683 else
1684 nlk->flags &= ~NETLINK_F_BROADCAST_SEND_ERROR;
1685 err = 0;
1686 break;
1687 case NETLINK_NO_ENOBUFS:
1688 if (val) {
1689 nlk->flags |= NETLINK_F_RECV_NO_ENOBUFS;
1690 clear_bit(NETLINK_S_CONGESTED, &nlk->state);
1691 wake_up_interruptible(&nlk->wait);
1692 } else {
1693 nlk->flags &= ~NETLINK_F_RECV_NO_ENOBUFS;
1694 }
1695 err = 0;
1696 break;
1697 case NETLINK_LISTEN_ALL_NSID:
1698 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_BROADCAST))
1699 return -EPERM;
1700
1701 if (val)
1702 nlk->flags |= NETLINK_F_LISTEN_ALL_NSID;
1703 else
1704 nlk->flags &= ~NETLINK_F_LISTEN_ALL_NSID;
1705 err = 0;
1706 break;
1707 case NETLINK_CAP_ACK:
1708 if (val)
1709 nlk->flags |= NETLINK_F_CAP_ACK;
1710 else
1711 nlk->flags &= ~NETLINK_F_CAP_ACK;
1712 err = 0;
1713 break;
1714 case NETLINK_EXT_ACK:
1715 if (val)
1716 nlk->flags |= NETLINK_F_EXT_ACK;
1717 else
1718 nlk->flags &= ~NETLINK_F_EXT_ACK;
1719 err = 0;
1720 break;
1721 case NETLINK_GET_STRICT_CHK:
1722 if (val)
1723 nlk->flags |= NETLINK_F_STRICT_CHK;
1724 else
1725 nlk->flags &= ~NETLINK_F_STRICT_CHK;
1726 err = 0;
1727 break;
1728 default:
1729 err = -ENOPROTOOPT;
1730 }
1731 return err;
1732}
1733
1734static int netlink_getsockopt(struct socket *sock, int level, int optname,
1735 char __user *optval, int __user *optlen)
1736{
1737 struct sock *sk = sock->sk;
1738 struct netlink_sock *nlk = nlk_sk(sk);
1739 int len, val, err;
1740
1741 if (level != SOL_NETLINK)
1742 return -ENOPROTOOPT;
1743
1744 if (get_user(len, optlen))
1745 return -EFAULT;
1746 if (len < 0)
1747 return -EINVAL;
1748
1749 switch (optname) {
1750 case NETLINK_PKTINFO:
1751 if (len < sizeof(int))
1752 return -EINVAL;
1753 len = sizeof(int);
1754 val = nlk->flags & NETLINK_F_RECV_PKTINFO ? 1 : 0;
1755 if (put_user(len, optlen) ||
1756 put_user(val, optval))
1757 return -EFAULT;
1758 err = 0;
1759 break;
1760 case NETLINK_BROADCAST_ERROR:
1761 if (len < sizeof(int))
1762 return -EINVAL;
1763 len = sizeof(int);
1764 val = nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR ? 1 : 0;
1765 if (put_user(len, optlen) ||
1766 put_user(val, optval))
1767 return -EFAULT;
1768 err = 0;
1769 break;
1770 case NETLINK_NO_ENOBUFS:
1771 if (len < sizeof(int))
1772 return -EINVAL;
1773 len = sizeof(int);
1774 val = nlk->flags & NETLINK_F_RECV_NO_ENOBUFS ? 1 : 0;
1775 if (put_user(len, optlen) ||
1776 put_user(val, optval))
1777 return -EFAULT;
1778 err = 0;
1779 break;
1780 case NETLINK_LIST_MEMBERSHIPS: {
1781 int pos, idx, shift;
1782
1783 err = 0;
1784 netlink_lock_table();
1785 for (pos = 0; pos * 8 < nlk->ngroups; pos += sizeof(u32)) {
1786 if (len - pos < sizeof(u32))
1787 break;
1788
1789 idx = pos / sizeof(unsigned long);
1790 shift = (pos % sizeof(unsigned long)) * 8;
1791 if (put_user((u32)(nlk->groups[idx] >> shift),
1792 (u32 __user *)(optval + pos))) {
1793 err = -EFAULT;
1794 break;
1795 }
1796 }
1797 if (put_user(ALIGN(nlk->ngroups / 8, sizeof(u32)), optlen))
1798 err = -EFAULT;
1799 netlink_unlock_table();
1800 break;
1801 }
1802 case NETLINK_CAP_ACK:
1803 if (len < sizeof(int))
1804 return -EINVAL;
1805 len = sizeof(int);
1806 val = nlk->flags & NETLINK_F_CAP_ACK ? 1 : 0;
1807 if (put_user(len, optlen) ||
1808 put_user(val, optval))
1809 return -EFAULT;
1810 err = 0;
1811 break;
1812 case NETLINK_EXT_ACK:
1813 if (len < sizeof(int))
1814 return -EINVAL;
1815 len = sizeof(int);
1816 val = nlk->flags & NETLINK_F_EXT_ACK ? 1 : 0;
1817 if (put_user(len, optlen) || put_user(val, optval))
1818 return -EFAULT;
1819 err = 0;
1820 break;
1821 case NETLINK_GET_STRICT_CHK:
1822 if (len < sizeof(int))
1823 return -EINVAL;
1824 len = sizeof(int);
1825 val = nlk->flags & NETLINK_F_STRICT_CHK ? 1 : 0;
1826 if (put_user(len, optlen) || put_user(val, optval))
1827 return -EFAULT;
1828 err = 0;
1829 break;
1830 default:
1831 err = -ENOPROTOOPT;
1832 }
1833 return err;
1834}
1835
1836static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
1837{
1838 struct nl_pktinfo info;
1839
1840 info.group = NETLINK_CB(skb).dst_group;
1841 put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info);
1842}
1843
1844static void netlink_cmsg_listen_all_nsid(struct sock *sk, struct msghdr *msg,
1845 struct sk_buff *skb)
1846{
1847 if (!NETLINK_CB(skb).nsid_is_set)
1848 return;
1849
1850 put_cmsg(msg, SOL_NETLINK, NETLINK_LISTEN_ALL_NSID, sizeof(int),
1851 &NETLINK_CB(skb).nsid);
1852}
1853
1854static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1855{
1856 struct sock *sk = sock->sk;
1857 struct netlink_sock *nlk = nlk_sk(sk);
1858 DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name);
1859 u32 dst_portid;
1860 u32 dst_group;
1861 struct sk_buff *skb;
1862 int err;
1863 struct scm_cookie scm;
1864 u32 netlink_skb_flags = 0;
1865
1866 if (msg->msg_flags & MSG_OOB)
1867 return -EOPNOTSUPP;
1868
1869 err = scm_send(sock, msg, &scm, true);
1870 if (err < 0)
1871 return err;
1872
1873 if (msg->msg_namelen) {
1874 err = -EINVAL;
1875 if (msg->msg_namelen < sizeof(struct sockaddr_nl))
1876 goto out;
1877 if (addr->nl_family != AF_NETLINK)
1878 goto out;
1879 dst_portid = addr->nl_pid;
1880 dst_group = ffs(addr->nl_groups);
1881 err = -EPERM;
1882 if ((dst_group || dst_portid) &&
1883 !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
1884 goto out;
1885 netlink_skb_flags |= NETLINK_SKB_DST;
1886 } else {
1887 dst_portid = nlk->dst_portid;
1888 dst_group = nlk->dst_group;
1889 }
1890
1891 if (!nlk->bound) {
1892 err = netlink_autobind(sock);
1893 if (err)
1894 goto out;
1895 } else {
1896
1897 smp_rmb();
1898 }
1899
1900 err = -EMSGSIZE;
1901 if (len > sk->sk_sndbuf - 32)
1902 goto out;
1903 err = -ENOBUFS;
1904 skb = netlink_alloc_large_skb(len, dst_group);
1905 if (skb == NULL)
1906 goto out;
1907
1908 NETLINK_CB(skb).portid = nlk->portid;
1909 NETLINK_CB(skb).dst_group = dst_group;
1910 NETLINK_CB(skb).creds = scm.creds;
1911 NETLINK_CB(skb).flags = netlink_skb_flags;
1912
1913 err = -EFAULT;
1914 if (memcpy_from_msg(skb_put(skb, len), msg, len)) {
1915 kfree_skb(skb);
1916 goto out;
1917 }
1918
1919 err = security_netlink_send(sk, skb);
1920 if (err) {
1921 kfree_skb(skb);
1922 goto out;
1923 }
1924
1925 if (dst_group) {
1926 refcount_inc(&skb->users);
1927 netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL);
1928 }
1929 err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags & MSG_DONTWAIT);
1930
1931out:
1932 scm_destroy(&scm);
1933 return err;
1934}
1935
1936static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
1937 int flags)
1938{
1939 struct scm_cookie scm;
1940 struct sock *sk = sock->sk;
1941 struct netlink_sock *nlk = nlk_sk(sk);
1942 int noblock = flags & MSG_DONTWAIT;
1943 size_t copied;
1944 struct sk_buff *skb, *data_skb;
1945 int err, ret;
1946
1947 if (flags & MSG_OOB)
1948 return -EOPNOTSUPP;
1949
1950 copied = 0;
1951
1952 skb = skb_recv_datagram(sk, flags, noblock, &err);
1953 if (skb == NULL)
1954 goto out;
1955
1956 data_skb = skb;
1957
1958#ifdef CONFIG_COMPAT_NETLINK_MESSAGES
1959 if (unlikely(skb_shinfo(skb)->frag_list)) {
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970 if (flags & MSG_CMSG_COMPAT)
1971 data_skb = skb_shinfo(skb)->frag_list;
1972 }
1973#endif
1974
1975
1976 nlk->max_recvmsg_len = max(nlk->max_recvmsg_len, len);
1977 nlk->max_recvmsg_len = min_t(size_t, nlk->max_recvmsg_len,
1978 SKB_WITH_OVERHEAD(32768));
1979
1980 copied = data_skb->len;
1981 if (len < copied) {
1982 msg->msg_flags |= MSG_TRUNC;
1983 copied = len;
1984 }
1985
1986 skb_reset_transport_header(data_skb);
1987 err = skb_copy_datagram_msg(data_skb, 0, msg, copied);
1988
1989 if (msg->msg_name) {
1990 DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name);
1991 addr->nl_family = AF_NETLINK;
1992 addr->nl_pad = 0;
1993 addr->nl_pid = NETLINK_CB(skb).portid;
1994 addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group);
1995 msg->msg_namelen = sizeof(*addr);
1996 }
1997
1998 if (nlk->flags & NETLINK_F_RECV_PKTINFO)
1999 netlink_cmsg_recv_pktinfo(msg, skb);
2000 if (nlk->flags & NETLINK_F_LISTEN_ALL_NSID)
2001 netlink_cmsg_listen_all_nsid(sk, msg, skb);
2002
2003 memset(&scm, 0, sizeof(scm));
2004 scm.creds = *NETLINK_CREDS(skb);
2005 if (flags & MSG_TRUNC)
2006 copied = data_skb->len;
2007
2008 skb_free_datagram(sk, skb);
2009
2010 if (nlk->cb_running &&
2011 atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) {
2012 ret = netlink_dump(sk);
2013 if (ret) {
2014 sk->sk_err = -ret;
2015 sk_error_report(sk);
2016 }
2017 }
2018
2019 scm_recv(sock, msg, &scm, flags);
2020out:
2021 netlink_rcv_wake(sk);
2022 return err ? : copied;
2023}
2024
2025static void netlink_data_ready(struct sock *sk)
2026{
2027 BUG();
2028}
2029
2030
2031
2032
2033
2034
2035
2036struct sock *
2037__netlink_kernel_create(struct net *net, int unit, struct module *module,
2038 struct netlink_kernel_cfg *cfg)
2039{
2040 struct socket *sock;
2041 struct sock *sk;
2042 struct netlink_sock *nlk;
2043 struct listeners *listeners = NULL;
2044 struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL;
2045 unsigned int groups;
2046
2047 BUG_ON(!nl_table);
2048
2049 if (unit < 0 || unit >= MAX_LINKS)
2050 return NULL;
2051
2052 if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
2053 return NULL;
2054
2055 if (__netlink_create(net, sock, cb_mutex, unit, 1) < 0)
2056 goto out_sock_release_nosk;
2057
2058 sk = sock->sk;
2059
2060 if (!cfg || cfg->groups < 32)
2061 groups = 32;
2062 else
2063 groups = cfg->groups;
2064
2065 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
2066 if (!listeners)
2067 goto out_sock_release;
2068
2069 sk->sk_data_ready = netlink_data_ready;
2070 if (cfg && cfg->input)
2071 nlk_sk(sk)->netlink_rcv = cfg->input;
2072
2073 if (netlink_insert(sk, 0))
2074 goto out_sock_release;
2075
2076 nlk = nlk_sk(sk);
2077 nlk->flags |= NETLINK_F_KERNEL_SOCKET;
2078
2079 netlink_table_grab();
2080 if (!nl_table[unit].registered) {
2081 nl_table[unit].groups = groups;
2082 rcu_assign_pointer(nl_table[unit].listeners, listeners);
2083 nl_table[unit].cb_mutex = cb_mutex;
2084 nl_table[unit].module = module;
2085 if (cfg) {
2086 nl_table[unit].bind = cfg->bind;
2087 nl_table[unit].unbind = cfg->unbind;
2088 nl_table[unit].flags = cfg->flags;
2089 if (cfg->compare)
2090 nl_table[unit].compare = cfg->compare;
2091 }
2092 nl_table[unit].registered = 1;
2093 } else {
2094 kfree(listeners);
2095 nl_table[unit].registered++;
2096 }
2097 netlink_table_ungrab();
2098 return sk;
2099
2100out_sock_release:
2101 kfree(listeners);
2102 netlink_kernel_release(sk);
2103 return NULL;
2104
2105out_sock_release_nosk:
2106 sock_release(sock);
2107 return NULL;
2108}
2109EXPORT_SYMBOL(__netlink_kernel_create);
2110
2111void
2112netlink_kernel_release(struct sock *sk)
2113{
2114 if (sk == NULL || sk->sk_socket == NULL)
2115 return;
2116
2117 sock_release(sk->sk_socket);
2118}
2119EXPORT_SYMBOL(netlink_kernel_release);
2120
2121int __netlink_change_ngroups(struct sock *sk, unsigned int groups)
2122{
2123 struct listeners *new, *old;
2124 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
2125
2126 if (groups < 32)
2127 groups = 32;
2128
2129 if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) {
2130 new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC);
2131 if (!new)
2132 return -ENOMEM;
2133 old = nl_deref_protected(tbl->listeners);
2134 memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups));
2135 rcu_assign_pointer(tbl->listeners, new);
2136
2137 kfree_rcu(old, rcu);
2138 }
2139 tbl->groups = groups;
2140
2141 return 0;
2142}
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156int netlink_change_ngroups(struct sock *sk, unsigned int groups)
2157{
2158 int err;
2159
2160 netlink_table_grab();
2161 err = __netlink_change_ngroups(sk, groups);
2162 netlink_table_ungrab();
2163
2164 return err;
2165}
2166
2167void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
2168{
2169 struct sock *sk;
2170 struct netlink_table *tbl = &nl_table[ksk->sk_protocol];
2171
2172 sk_for_each_bound(sk, &tbl->mc_list)
2173 netlink_update_socket_mc(nlk_sk(sk), group, 0);
2174}
2175
2176struct nlmsghdr *
2177__nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags)
2178{
2179 struct nlmsghdr *nlh;
2180 int size = nlmsg_msg_size(len);
2181
2182 nlh = skb_put(skb, NLMSG_ALIGN(size));
2183 nlh->nlmsg_type = type;
2184 nlh->nlmsg_len = size;
2185 nlh->nlmsg_flags = flags;
2186 nlh->nlmsg_pid = portid;
2187 nlh->nlmsg_seq = seq;
2188 if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0)
2189 memset(nlmsg_data(nlh) + len, 0, NLMSG_ALIGN(size) - size);
2190 return nlh;
2191}
2192EXPORT_SYMBOL(__nlmsg_put);
2193
2194
2195
2196
2197
2198
2199static int netlink_dump_done(struct netlink_sock *nlk, struct sk_buff *skb,
2200 struct netlink_callback *cb,
2201 struct netlink_ext_ack *extack)
2202{
2203 struct nlmsghdr *nlh;
2204
2205 nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(nlk->dump_done_errno),
2206 NLM_F_MULTI | cb->answer_flags);
2207 if (WARN_ON(!nlh))
2208 return -ENOBUFS;
2209
2210 nl_dump_check_consistent(cb, nlh);
2211 memcpy(nlmsg_data(nlh), &nlk->dump_done_errno, sizeof(nlk->dump_done_errno));
2212
2213 if (extack->_msg && nlk->flags & NETLINK_F_EXT_ACK) {
2214 nlh->nlmsg_flags |= NLM_F_ACK_TLVS;
2215 if (!nla_put_string(skb, NLMSGERR_ATTR_MSG, extack->_msg))
2216 nlmsg_end(skb, nlh);
2217 }
2218
2219 return 0;
2220}
2221
2222static int netlink_dump(struct sock *sk)
2223{
2224 struct netlink_sock *nlk = nlk_sk(sk);
2225 struct netlink_ext_ack extack = {};
2226 struct netlink_callback *cb;
2227 struct sk_buff *skb = NULL;
2228 struct module *module;
2229 int err = -ENOBUFS;
2230 int alloc_min_size;
2231 int alloc_size;
2232
2233 mutex_lock(nlk->cb_mutex);
2234 if (!nlk->cb_running) {
2235 err = -EINVAL;
2236 goto errout_skb;
2237 }
2238
2239 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2240 goto errout_skb;
2241
2242
2243
2244
2245
2246
2247 cb = &nlk->cb;
2248 alloc_min_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE);
2249
2250 if (alloc_min_size < nlk->max_recvmsg_len) {
2251 alloc_size = nlk->max_recvmsg_len;
2252 skb = alloc_skb(alloc_size,
2253 (GFP_KERNEL & ~__GFP_DIRECT_RECLAIM) |
2254 __GFP_NOWARN | __GFP_NORETRY);
2255 }
2256 if (!skb) {
2257 alloc_size = alloc_min_size;
2258 skb = alloc_skb(alloc_size, GFP_KERNEL);
2259 }
2260 if (!skb)
2261 goto errout_skb;
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273 skb_reserve(skb, skb_tailroom(skb) - alloc_size);
2274 netlink_skb_set_owner_r(skb, sk);
2275
2276 if (nlk->dump_done_errno > 0) {
2277 cb->extack = &extack;
2278 nlk->dump_done_errno = cb->dump(skb, cb);
2279 cb->extack = NULL;
2280 }
2281
2282 if (nlk->dump_done_errno > 0 ||
2283 skb_tailroom(skb) < nlmsg_total_size(sizeof(nlk->dump_done_errno))) {
2284 mutex_unlock(nlk->cb_mutex);
2285
2286 if (sk_filter(sk, skb))
2287 kfree_skb(skb);
2288 else
2289 __netlink_sendskb(sk, skb);
2290 return 0;
2291 }
2292
2293 if (netlink_dump_done(nlk, skb, cb, &extack))
2294 goto errout_skb;
2295
2296#ifdef CONFIG_COMPAT_NETLINK_MESSAGES
2297
2298
2299
2300
2301 if (unlikely(skb_shinfo(skb)->frag_list)) {
2302 if (netlink_dump_done(nlk, skb_shinfo(skb)->frag_list, cb, &extack))
2303 goto errout_skb;
2304 }
2305#endif
2306
2307 if (sk_filter(sk, skb))
2308 kfree_skb(skb);
2309 else
2310 __netlink_sendskb(sk, skb);
2311
2312 if (cb->done)
2313 cb->done(cb);
2314
2315 nlk->cb_running = false;
2316 module = cb->module;
2317 skb = cb->skb;
2318 mutex_unlock(nlk->cb_mutex);
2319 module_put(module);
2320 consume_skb(skb);
2321 return 0;
2322
2323errout_skb:
2324 mutex_unlock(nlk->cb_mutex);
2325 kfree_skb(skb);
2326 return err;
2327}
2328
2329int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
2330 const struct nlmsghdr *nlh,
2331 struct netlink_dump_control *control)
2332{
2333 struct netlink_sock *nlk, *nlk2;
2334 struct netlink_callback *cb;
2335 struct sock *sk;
2336 int ret;
2337
2338 refcount_inc(&skb->users);
2339
2340 sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).portid);
2341 if (sk == NULL) {
2342 ret = -ECONNREFUSED;
2343 goto error_free;
2344 }
2345
2346 nlk = nlk_sk(sk);
2347 mutex_lock(nlk->cb_mutex);
2348
2349 if (nlk->cb_running) {
2350 ret = -EBUSY;
2351 goto error_unlock;
2352 }
2353
2354 if (!try_module_get(control->module)) {
2355 ret = -EPROTONOSUPPORT;
2356 goto error_unlock;
2357 }
2358
2359 cb = &nlk->cb;
2360 memset(cb, 0, sizeof(*cb));
2361 cb->dump = control->dump;
2362 cb->done = control->done;
2363 cb->nlh = nlh;
2364 cb->data = control->data;
2365 cb->module = control->module;
2366 cb->min_dump_alloc = control->min_dump_alloc;
2367 cb->skb = skb;
2368
2369 nlk2 = nlk_sk(NETLINK_CB(skb).sk);
2370 cb->strict_check = !!(nlk2->flags & NETLINK_F_STRICT_CHK);
2371
2372 if (control->start) {
2373 ret = control->start(cb);
2374 if (ret)
2375 goto error_put;
2376 }
2377
2378 nlk->cb_running = true;
2379 nlk->dump_done_errno = INT_MAX;
2380
2381 mutex_unlock(nlk->cb_mutex);
2382
2383 ret = netlink_dump(sk);
2384
2385 sock_put(sk);
2386
2387 if (ret)
2388 return ret;
2389
2390
2391
2392
2393 return -EINTR;
2394
2395error_put:
2396 module_put(control->module);
2397error_unlock:
2398 sock_put(sk);
2399 mutex_unlock(nlk->cb_mutex);
2400error_free:
2401 kfree_skb(skb);
2402 return ret;
2403}
2404EXPORT_SYMBOL(__netlink_dump_start);
2405
2406void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
2407 const struct netlink_ext_ack *extack)
2408{
2409 struct sk_buff *skb;
2410 struct nlmsghdr *rep;
2411 struct nlmsgerr *errmsg;
2412 size_t payload = sizeof(*errmsg);
2413 size_t tlvlen = 0;
2414 struct netlink_sock *nlk = nlk_sk(NETLINK_CB(in_skb).sk);
2415 unsigned int flags = 0;
2416 bool nlk_has_extack = nlk->flags & NETLINK_F_EXT_ACK;
2417
2418
2419
2420
2421
2422 if (nlk_has_extack && extack && extack->_msg)
2423 tlvlen += nla_total_size(strlen(extack->_msg) + 1);
2424
2425 if (err && !(nlk->flags & NETLINK_F_CAP_ACK))
2426 payload += nlmsg_len(nlh);
2427 else
2428 flags |= NLM_F_CAPPED;
2429 if (err && nlk_has_extack && extack && extack->bad_attr)
2430 tlvlen += nla_total_size(sizeof(u32));
2431 if (nlk_has_extack && extack && extack->cookie_len)
2432 tlvlen += nla_total_size(extack->cookie_len);
2433 if (err && nlk_has_extack && extack && extack->policy)
2434 tlvlen += netlink_policy_dump_attr_size_estimate(extack->policy);
2435
2436 if (tlvlen)
2437 flags |= NLM_F_ACK_TLVS;
2438
2439 skb = nlmsg_new(payload + tlvlen, GFP_KERNEL);
2440 if (!skb) {
2441 NETLINK_CB(in_skb).sk->sk_err = ENOBUFS;
2442 sk_error_report(NETLINK_CB(in_skb).sk);
2443 return;
2444 }
2445
2446 rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2447 NLMSG_ERROR, payload, flags);
2448 errmsg = nlmsg_data(rep);
2449 errmsg->error = err;
2450 memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh));
2451
2452 if (nlk_has_extack && extack) {
2453 if (extack->_msg) {
2454 WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG,
2455 extack->_msg));
2456 }
2457 if (err && extack->bad_attr &&
2458 !WARN_ON((u8 *)extack->bad_attr < in_skb->data ||
2459 (u8 *)extack->bad_attr >= in_skb->data +
2460 in_skb->len))
2461 WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS,
2462 (u8 *)extack->bad_attr -
2463 (u8 *)nlh));
2464 if (extack->cookie_len)
2465 WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE,
2466 extack->cookie_len, extack->cookie));
2467 if (extack->policy)
2468 netlink_policy_dump_write_attr(skb, extack->policy,
2469 NLMSGERR_ATTR_POLICY);
2470 }
2471
2472 nlmsg_end(skb, rep);
2473
2474 nlmsg_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid);
2475}
2476EXPORT_SYMBOL(netlink_ack);
2477
2478int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
2479 struct nlmsghdr *,
2480 struct netlink_ext_ack *))
2481{
2482 struct netlink_ext_ack extack;
2483 struct nlmsghdr *nlh;
2484 int err;
2485
2486 while (skb->len >= nlmsg_total_size(0)) {
2487 int msglen;
2488
2489 memset(&extack, 0, sizeof(extack));
2490 nlh = nlmsg_hdr(skb);
2491 err = 0;
2492
2493 if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
2494 return 0;
2495
2496
2497 if (!(nlh->nlmsg_flags & NLM_F_REQUEST))
2498 goto ack;
2499
2500
2501 if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
2502 goto ack;
2503
2504 err = cb(skb, nlh, &extack);
2505 if (err == -EINTR)
2506 goto skip;
2507
2508ack:
2509 if (nlh->nlmsg_flags & NLM_F_ACK || err)
2510 netlink_ack(skb, nlh, err, &extack);
2511
2512skip:
2513 msglen = NLMSG_ALIGN(nlh->nlmsg_len);
2514 if (msglen > skb->len)
2515 msglen = skb->len;
2516 skb_pull(skb, msglen);
2517 }
2518
2519 return 0;
2520}
2521EXPORT_SYMBOL(netlink_rcv_skb);
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
2533 unsigned int group, int report, gfp_t flags)
2534{
2535 int err = 0;
2536
2537 if (group) {
2538 int exclude_portid = 0;
2539
2540 if (report) {
2541 refcount_inc(&skb->users);
2542 exclude_portid = portid;
2543 }
2544
2545
2546
2547 err = nlmsg_multicast(sk, skb, exclude_portid, group, flags);
2548 }
2549
2550 if (report) {
2551 int err2;
2552
2553 err2 = nlmsg_unicast(sk, skb, portid);
2554 if (!err || err == -ESRCH)
2555 err = err2;
2556 }
2557
2558 return err;
2559}
2560EXPORT_SYMBOL(nlmsg_notify);
2561
2562#ifdef CONFIG_PROC_FS
2563struct nl_seq_iter {
2564 struct seq_net_private p;
2565 struct rhashtable_iter hti;
2566 int link;
2567};
2568
2569static void netlink_walk_start(struct nl_seq_iter *iter)
2570{
2571 rhashtable_walk_enter(&nl_table[iter->link].hash, &iter->hti);
2572 rhashtable_walk_start(&iter->hti);
2573}
2574
2575static void netlink_walk_stop(struct nl_seq_iter *iter)
2576{
2577 rhashtable_walk_stop(&iter->hti);
2578 rhashtable_walk_exit(&iter->hti);
2579}
2580
2581static void *__netlink_seq_next(struct seq_file *seq)
2582{
2583 struct nl_seq_iter *iter = seq->private;
2584 struct netlink_sock *nlk;
2585
2586 do {
2587 for (;;) {
2588 nlk = rhashtable_walk_next(&iter->hti);
2589
2590 if (IS_ERR(nlk)) {
2591 if (PTR_ERR(nlk) == -EAGAIN)
2592 continue;
2593
2594 return nlk;
2595 }
2596
2597 if (nlk)
2598 break;
2599
2600 netlink_walk_stop(iter);
2601 if (++iter->link >= MAX_LINKS)
2602 return NULL;
2603
2604 netlink_walk_start(iter);
2605 }
2606 } while (sock_net(&nlk->sk) != seq_file_net(seq));
2607
2608 return nlk;
2609}
2610
2611static void *netlink_seq_start(struct seq_file *seq, loff_t *posp)
2612 __acquires(RCU)
2613{
2614 struct nl_seq_iter *iter = seq->private;
2615 void *obj = SEQ_START_TOKEN;
2616 loff_t pos;
2617
2618 iter->link = 0;
2619
2620 netlink_walk_start(iter);
2621
2622 for (pos = *posp; pos && obj && !IS_ERR(obj); pos--)
2623 obj = __netlink_seq_next(seq);
2624
2625 return obj;
2626}
2627
2628static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2629{
2630 ++*pos;
2631 return __netlink_seq_next(seq);
2632}
2633
2634static void netlink_native_seq_stop(struct seq_file *seq, void *v)
2635{
2636 struct nl_seq_iter *iter = seq->private;
2637
2638 if (iter->link >= MAX_LINKS)
2639 return;
2640
2641 netlink_walk_stop(iter);
2642}
2643
2644
2645static int netlink_native_seq_show(struct seq_file *seq, void *v)
2646{
2647 if (v == SEQ_START_TOKEN) {
2648 seq_puts(seq,
2649 "sk Eth Pid Groups "
2650 "Rmem Wmem Dump Locks Drops Inode\n");
2651 } else {
2652 struct sock *s = v;
2653 struct netlink_sock *nlk = nlk_sk(s);
2654
2655 seq_printf(seq, "%pK %-3d %-10u %08x %-8d %-8d %-5d %-8d %-8u %-8lu\n",
2656 s,
2657 s->sk_protocol,
2658 nlk->portid,
2659 nlk->groups ? (u32)nlk->groups[0] : 0,
2660 sk_rmem_alloc_get(s),
2661 sk_wmem_alloc_get(s),
2662 nlk->cb_running,
2663 refcount_read(&s->sk_refcnt),
2664 atomic_read(&s->sk_drops),
2665 sock_i_ino(s)
2666 );
2667
2668 }
2669 return 0;
2670}
2671
2672#ifdef CONFIG_BPF_SYSCALL
2673struct bpf_iter__netlink {
2674 __bpf_md_ptr(struct bpf_iter_meta *, meta);
2675 __bpf_md_ptr(struct netlink_sock *, sk);
2676};
2677
2678DEFINE_BPF_ITER_FUNC(netlink, struct bpf_iter_meta *meta, struct netlink_sock *sk)
2679
2680static int netlink_prog_seq_show(struct bpf_prog *prog,
2681 struct bpf_iter_meta *meta,
2682 void *v)
2683{
2684 struct bpf_iter__netlink ctx;
2685
2686 meta->seq_num--;
2687 ctx.meta = meta;
2688 ctx.sk = nlk_sk((struct sock *)v);
2689 return bpf_iter_run_prog(prog, &ctx);
2690}
2691
2692static int netlink_seq_show(struct seq_file *seq, void *v)
2693{
2694 struct bpf_iter_meta meta;
2695 struct bpf_prog *prog;
2696
2697 meta.seq = seq;
2698 prog = bpf_iter_get_info(&meta, false);
2699 if (!prog)
2700 return netlink_native_seq_show(seq, v);
2701
2702 if (v != SEQ_START_TOKEN)
2703 return netlink_prog_seq_show(prog, &meta, v);
2704
2705 return 0;
2706}
2707
2708static void netlink_seq_stop(struct seq_file *seq, void *v)
2709{
2710 struct bpf_iter_meta meta;
2711 struct bpf_prog *prog;
2712
2713 if (!v) {
2714 meta.seq = seq;
2715 prog = bpf_iter_get_info(&meta, true);
2716 if (prog)
2717 (void)netlink_prog_seq_show(prog, &meta, v);
2718 }
2719
2720 netlink_native_seq_stop(seq, v);
2721}
2722#else
2723static int netlink_seq_show(struct seq_file *seq, void *v)
2724{
2725 return netlink_native_seq_show(seq, v);
2726}
2727
2728static void netlink_seq_stop(struct seq_file *seq, void *v)
2729{
2730 netlink_native_seq_stop(seq, v);
2731}
2732#endif
2733
2734static const struct seq_operations netlink_seq_ops = {
2735 .start = netlink_seq_start,
2736 .next = netlink_seq_next,
2737 .stop = netlink_seq_stop,
2738 .show = netlink_seq_show,
2739};
2740#endif
2741
2742int netlink_register_notifier(struct notifier_block *nb)
2743{
2744 return blocking_notifier_chain_register(&netlink_chain, nb);
2745}
2746EXPORT_SYMBOL(netlink_register_notifier);
2747
2748int netlink_unregister_notifier(struct notifier_block *nb)
2749{
2750 return blocking_notifier_chain_unregister(&netlink_chain, nb);
2751}
2752EXPORT_SYMBOL(netlink_unregister_notifier);
2753
2754static const struct proto_ops netlink_ops = {
2755 .family = PF_NETLINK,
2756 .owner = THIS_MODULE,
2757 .release = netlink_release,
2758 .bind = netlink_bind,
2759 .connect = netlink_connect,
2760 .socketpair = sock_no_socketpair,
2761 .accept = sock_no_accept,
2762 .getname = netlink_getname,
2763 .poll = datagram_poll,
2764 .ioctl = netlink_ioctl,
2765 .listen = sock_no_listen,
2766 .shutdown = sock_no_shutdown,
2767 .setsockopt = netlink_setsockopt,
2768 .getsockopt = netlink_getsockopt,
2769 .sendmsg = netlink_sendmsg,
2770 .recvmsg = netlink_recvmsg,
2771 .mmap = sock_no_mmap,
2772 .sendpage = sock_no_sendpage,
2773};
2774
2775static const struct net_proto_family netlink_family_ops = {
2776 .family = PF_NETLINK,
2777 .create = netlink_create,
2778 .owner = THIS_MODULE,
2779};
2780
2781static int __net_init netlink_net_init(struct net *net)
2782{
2783#ifdef CONFIG_PROC_FS
2784 if (!proc_create_net("netlink", 0, net->proc_net, &netlink_seq_ops,
2785 sizeof(struct nl_seq_iter)))
2786 return -ENOMEM;
2787#endif
2788 return 0;
2789}
2790
2791static void __net_exit netlink_net_exit(struct net *net)
2792{
2793#ifdef CONFIG_PROC_FS
2794 remove_proc_entry("netlink", net->proc_net);
2795#endif
2796}
2797
2798static void __init netlink_add_usersock_entry(void)
2799{
2800 struct listeners *listeners;
2801 int groups = 32;
2802
2803 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
2804 if (!listeners)
2805 panic("netlink_add_usersock_entry: Cannot allocate listeners\n");
2806
2807 netlink_table_grab();
2808
2809 nl_table[NETLINK_USERSOCK].groups = groups;
2810 rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners);
2811 nl_table[NETLINK_USERSOCK].module = THIS_MODULE;
2812 nl_table[NETLINK_USERSOCK].registered = 1;
2813 nl_table[NETLINK_USERSOCK].flags = NL_CFG_F_NONROOT_SEND;
2814
2815 netlink_table_ungrab();
2816}
2817
2818static struct pernet_operations __net_initdata netlink_net_ops = {
2819 .init = netlink_net_init,
2820 .exit = netlink_net_exit,
2821};
2822
2823static inline u32 netlink_hash(const void *data, u32 len, u32 seed)
2824{
2825 const struct netlink_sock *nlk = data;
2826 struct netlink_compare_arg arg;
2827
2828 netlink_compare_arg_init(&arg, sock_net(&nlk->sk), nlk->portid);
2829 return jhash2((u32 *)&arg, netlink_compare_arg_len / sizeof(u32), seed);
2830}
2831
2832static const struct rhashtable_params netlink_rhashtable_params = {
2833 .head_offset = offsetof(struct netlink_sock, node),
2834 .key_len = netlink_compare_arg_len,
2835 .obj_hashfn = netlink_hash,
2836 .obj_cmpfn = netlink_compare,
2837 .automatic_shrinking = true,
2838};
2839
2840#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
2841BTF_ID_LIST(btf_netlink_sock_id)
2842BTF_ID(struct, netlink_sock)
2843
2844static const struct bpf_iter_seq_info netlink_seq_info = {
2845 .seq_ops = &netlink_seq_ops,
2846 .init_seq_private = bpf_iter_init_seq_net,
2847 .fini_seq_private = bpf_iter_fini_seq_net,
2848 .seq_priv_size = sizeof(struct nl_seq_iter),
2849};
2850
2851static struct bpf_iter_reg netlink_reg_info = {
2852 .target = "netlink",
2853 .ctx_arg_info_size = 1,
2854 .ctx_arg_info = {
2855 { offsetof(struct bpf_iter__netlink, sk),
2856 PTR_TO_BTF_ID_OR_NULL },
2857 },
2858 .seq_info = &netlink_seq_info,
2859};
2860
2861static int __init bpf_iter_register(void)
2862{
2863 netlink_reg_info.ctx_arg_info[0].btf_id = *btf_netlink_sock_id;
2864 return bpf_iter_reg_target(&netlink_reg_info);
2865}
2866#endif
2867
2868static int __init netlink_proto_init(void)
2869{
2870 int i;
2871 int err = proto_register(&netlink_proto, 0);
2872
2873 if (err != 0)
2874 goto out;
2875
2876#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
2877 err = bpf_iter_register();
2878 if (err)
2879 goto out;
2880#endif
2881
2882 BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof_field(struct sk_buff, cb));
2883
2884 nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);
2885 if (!nl_table)
2886 goto panic;
2887
2888 for (i = 0; i < MAX_LINKS; i++) {
2889 if (rhashtable_init(&nl_table[i].hash,
2890 &netlink_rhashtable_params) < 0) {
2891 while (--i > 0)
2892 rhashtable_destroy(&nl_table[i].hash);
2893 kfree(nl_table);
2894 goto panic;
2895 }
2896 }
2897
2898 netlink_add_usersock_entry();
2899
2900 sock_register(&netlink_family_ops);
2901 register_pernet_subsys(&netlink_net_ops);
2902 register_pernet_subsys(&netlink_tap_net_ops);
2903
2904 rtnetlink_init();
2905out:
2906 return err;
2907panic:
2908 panic("netlink_init: Cannot allocate nl_table\n");
2909}
2910
2911core_initcall(netlink_proto_init);
2912