2 * NETLINK Kernel-user communication protocol.
4 * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk>
5 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
6 * Patrick McHardy <kaber@trash.net>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
13 * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith
14 * added netlink_proto_exit
15 * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br>
16 * use nlk_sk, as sk->protinfo is on a diet 8)
17 * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org>
18 * - inc module use count of module that owns
19 * the kernel socket in case userspace opens
20 * socket of same protocol
21 * - remove all module support, since netlink is
22 * mandatory if CONFIG_NET=y these days
25 #include <linux/module.h>
27 #include <linux/capability.h>
28 #include <linux/kernel.h>
29 #include <linux/init.h>
30 #include <linux/signal.h>
31 #include <linux/sched.h>
32 #include <linux/errno.h>
33 #include <linux/string.h>
34 #include <linux/stat.h>
35 #include <linux/socket.h>
37 #include <linux/fcntl.h>
38 #include <linux/termios.h>
39 #include <linux/sockios.h>
40 #include <linux/net.h>
42 #include <linux/slab.h>
43 #include <asm/uaccess.h>
44 #include <linux/skbuff.h>
45 #include <linux/netdevice.h>
46 #include <linux/rtnetlink.h>
47 #include <linux/proc_fs.h>
48 #include <linux/seq_file.h>
49 #include <linux/notifier.h>
50 #include <linux/security.h>
51 #include <linux/jhash.h>
52 #include <linux/jiffies.h>
53 #include <linux/random.h>
54 #include <linux/bitops.h>
56 #include <linux/types.h>
57 #include <linux/audit.h>
58 #include <linux/mutex.h>
59 #include <linux/vmalloc.h>
60 #include <linux/if_arp.h>
61 #include <linux/rhashtable.h>
62 #include <asm/cacheflush.h>
63 #include <linux/hash.h>
64 #include <linux/genetlink.h>
66 #include <net/net_namespace.h>
69 #include <net/netlink.h>
71 #include "af_netlink.h"
75 unsigned long masks
[0];
79 #define NETLINK_S_CONGESTED 0x0
82 #define NETLINK_F_KERNEL_SOCKET 0x1
83 #define NETLINK_F_RECV_PKTINFO 0x2
84 #define NETLINK_F_BROADCAST_SEND_ERROR 0x4
85 #define NETLINK_F_RECV_NO_ENOBUFS 0x8
86 #define NETLINK_F_LISTEN_ALL_NSID 0x10
87 #define NETLINK_F_CAP_ACK 0x20
89 static inline int netlink_is_kernel(struct sock
*sk
)
91 return nlk_sk(sk
)->flags
& NETLINK_F_KERNEL_SOCKET
;
94 struct netlink_table
*nl_table __read_mostly
;
95 EXPORT_SYMBOL_GPL(nl_table
);
97 static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait
);
99 static int netlink_dump(struct sock
*sk
);
100 static void netlink_skb_destructor(struct sk_buff
*skb
);
102 /* nl_table locking explained:
103 * Lookup and traversal are protected with an RCU read-side lock. Insertion
104 * and removal are protected with per bucket lock while using RCU list
105 * modification primitives and may run in parallel to RCU protected lookups.
106 * Destruction of the Netlink socket may only occur *after* nl_table_lock has
107 * been acquired * either during or after the socket has been removed from
108 * the list and after an RCU grace period.
110 DEFINE_RWLOCK(nl_table_lock
);
111 EXPORT_SYMBOL_GPL(nl_table_lock
);
112 static atomic_t nl_table_users
= ATOMIC_INIT(0);
114 #define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock));
116 static ATOMIC_NOTIFIER_HEAD(netlink_chain
);
118 static DEFINE_SPINLOCK(netlink_tap_lock
);
119 static struct list_head netlink_tap_all __read_mostly
;
121 static const struct rhashtable_params netlink_rhashtable_params
;
123 static inline u32
netlink_group_mask(u32 group
)
125 return group
? 1 << (group
- 1) : 0;
128 int netlink_add_tap(struct netlink_tap
*nt
)
130 if (unlikely(nt
->dev
->type
!= ARPHRD_NETLINK
))
133 spin_lock(&netlink_tap_lock
);
134 list_add_rcu(&nt
->list
, &netlink_tap_all
);
135 spin_unlock(&netlink_tap_lock
);
137 __module_get(nt
->module
);
141 EXPORT_SYMBOL_GPL(netlink_add_tap
);
143 static int __netlink_remove_tap(struct netlink_tap
*nt
)
146 struct netlink_tap
*tmp
;
148 spin_lock(&netlink_tap_lock
);
150 list_for_each_entry(tmp
, &netlink_tap_all
, list
) {
152 list_del_rcu(&nt
->list
);
158 pr_warn("__netlink_remove_tap: %p not found\n", nt
);
160 spin_unlock(&netlink_tap_lock
);
163 module_put(nt
->module
);
165 return found
? 0 : -ENODEV
;
168 int netlink_remove_tap(struct netlink_tap
*nt
)
172 ret
= __netlink_remove_tap(nt
);
177 EXPORT_SYMBOL_GPL(netlink_remove_tap
);
179 static bool netlink_filter_tap(const struct sk_buff
*skb
)
181 struct sock
*sk
= skb
->sk
;
183 /* We take the more conservative approach and
184 * whitelist socket protocols that may pass.
186 switch (sk
->sk_protocol
) {
188 case NETLINK_USERSOCK
:
189 case NETLINK_SOCK_DIAG
:
192 case NETLINK_FIB_LOOKUP
:
193 case NETLINK_NETFILTER
:
194 case NETLINK_GENERIC
:
201 static int __netlink_deliver_tap_skb(struct sk_buff
*skb
,
202 struct net_device
*dev
)
204 struct sk_buff
*nskb
;
205 struct sock
*sk
= skb
->sk
;
209 nskb
= skb_clone(skb
, GFP_ATOMIC
);
212 nskb
->protocol
= htons((u16
) sk
->sk_protocol
);
213 nskb
->pkt_type
= netlink_is_kernel(sk
) ?
214 PACKET_KERNEL
: PACKET_USER
;
215 skb_reset_network_header(nskb
);
216 ret
= dev_queue_xmit(nskb
);
217 if (unlikely(ret
> 0))
218 ret
= net_xmit_errno(ret
);
225 static void __netlink_deliver_tap(struct sk_buff
*skb
)
228 struct netlink_tap
*tmp
;
230 if (!netlink_filter_tap(skb
))
233 list_for_each_entry_rcu(tmp
, &netlink_tap_all
, list
) {
234 ret
= __netlink_deliver_tap_skb(skb
, tmp
->dev
);
240 static void netlink_deliver_tap(struct sk_buff
*skb
)
244 if (unlikely(!list_empty(&netlink_tap_all
)))
245 __netlink_deliver_tap(skb
);
250 static void netlink_deliver_tap_kernel(struct sock
*dst
, struct sock
*src
,
253 if (!(netlink_is_kernel(dst
) && netlink_is_kernel(src
)))
254 netlink_deliver_tap(skb
);
257 static void netlink_overrun(struct sock
*sk
)
259 struct netlink_sock
*nlk
= nlk_sk(sk
);
261 if (!(nlk
->flags
& NETLINK_F_RECV_NO_ENOBUFS
)) {
262 if (!test_and_set_bit(NETLINK_S_CONGESTED
,
263 &nlk_sk(sk
)->state
)) {
264 sk
->sk_err
= ENOBUFS
;
265 sk
->sk_error_report(sk
);
268 atomic_inc(&sk
->sk_drops
);
271 static void netlink_rcv_wake(struct sock
*sk
)
273 struct netlink_sock
*nlk
= nlk_sk(sk
);
275 if (skb_queue_empty(&sk
->sk_receive_queue
))
276 clear_bit(NETLINK_S_CONGESTED
, &nlk
->state
);
277 if (!test_bit(NETLINK_S_CONGESTED
, &nlk
->state
))
278 wake_up_interruptible(&nlk
->wait
);
281 #ifdef CONFIG_NETLINK_MMAP
282 static bool netlink_skb_is_mmaped(const struct sk_buff
*skb
)
284 return NETLINK_CB(skb
).flags
& NETLINK_SKB_MMAPED
;
287 static bool netlink_rx_is_mmaped(struct sock
*sk
)
289 return nlk_sk(sk
)->rx_ring
.pg_vec
!= NULL
;
292 static bool netlink_tx_is_mmaped(struct sock
*sk
)
294 return nlk_sk(sk
)->tx_ring
.pg_vec
!= NULL
;
297 static __pure
struct page
*pgvec_to_page(const void *addr
)
299 if (is_vmalloc_addr(addr
))
300 return vmalloc_to_page(addr
);
302 return virt_to_page(addr
);
305 static void free_pg_vec(void **pg_vec
, unsigned int order
, unsigned int len
)
309 for (i
= 0; i
< len
; i
++) {
310 if (pg_vec
[i
] != NULL
) {
311 if (is_vmalloc_addr(pg_vec
[i
]))
314 free_pages((unsigned long)pg_vec
[i
], order
);
320 static void *alloc_one_pg_vec_page(unsigned long order
)
323 gfp_t gfp_flags
= GFP_KERNEL
| __GFP_COMP
| __GFP_ZERO
|
324 __GFP_NOWARN
| __GFP_NORETRY
;
326 buffer
= (void *)__get_free_pages(gfp_flags
, order
);
330 buffer
= vzalloc((1 << order
) * PAGE_SIZE
);
334 gfp_flags
&= ~__GFP_NORETRY
;
335 return (void *)__get_free_pages(gfp_flags
, order
);
338 static void **alloc_pg_vec(struct netlink_sock
*nlk
,
339 struct nl_mmap_req
*req
, unsigned int order
)
341 unsigned int block_nr
= req
->nm_block_nr
;
345 pg_vec
= kcalloc(block_nr
, sizeof(void *), GFP_KERNEL
);
349 for (i
= 0; i
< block_nr
; i
++) {
350 pg_vec
[i
] = alloc_one_pg_vec_page(order
);
351 if (pg_vec
[i
] == NULL
)
357 free_pg_vec(pg_vec
, order
, block_nr
);
363 __netlink_set_ring(struct sock
*sk
, struct nl_mmap_req
*req
, bool tx_ring
, void **pg_vec
,
366 struct netlink_sock
*nlk
= nlk_sk(sk
);
367 struct sk_buff_head
*queue
;
368 struct netlink_ring
*ring
;
370 queue
= tx_ring
? &sk
->sk_write_queue
: &sk
->sk_receive_queue
;
371 ring
= tx_ring
? &nlk
->tx_ring
: &nlk
->rx_ring
;
373 spin_lock_bh(&queue
->lock
);
375 ring
->frame_max
= req
->nm_frame_nr
- 1;
377 ring
->frame_size
= req
->nm_frame_size
;
378 ring
->pg_vec_pages
= req
->nm_block_size
/ PAGE_SIZE
;
380 swap(ring
->pg_vec_len
, req
->nm_block_nr
);
381 swap(ring
->pg_vec_order
, order
);
382 swap(ring
->pg_vec
, pg_vec
);
384 __skb_queue_purge(queue
);
385 spin_unlock_bh(&queue
->lock
);
387 WARN_ON(atomic_read(&nlk
->mapped
));
390 free_pg_vec(pg_vec
, order
, req
->nm_block_nr
);
393 static int netlink_set_ring(struct sock
*sk
, struct nl_mmap_req
*req
,
396 struct netlink_sock
*nlk
= nlk_sk(sk
);
397 struct netlink_ring
*ring
;
398 void **pg_vec
= NULL
;
399 unsigned int order
= 0;
401 ring
= tx_ring
? &nlk
->tx_ring
: &nlk
->rx_ring
;
403 if (atomic_read(&nlk
->mapped
))
405 if (atomic_read(&ring
->pending
))
408 if (req
->nm_block_nr
) {
409 if (ring
->pg_vec
!= NULL
)
412 if ((int)req
->nm_block_size
<= 0)
414 if (!PAGE_ALIGNED(req
->nm_block_size
))
416 if (req
->nm_frame_size
< NL_MMAP_HDRLEN
)
418 if (!IS_ALIGNED(req
->nm_frame_size
, NL_MMAP_MSG_ALIGNMENT
))
421 ring
->frames_per_block
= req
->nm_block_size
/
423 if (ring
->frames_per_block
== 0)
425 if (ring
->frames_per_block
* req
->nm_block_nr
!=
429 order
= get_order(req
->nm_block_size
);
430 pg_vec
= alloc_pg_vec(nlk
, req
, order
);
434 if (req
->nm_frame_nr
)
438 mutex_lock(&nlk
->pg_vec_lock
);
439 if (atomic_read(&nlk
->mapped
) == 0) {
440 __netlink_set_ring(sk
, req
, tx_ring
, pg_vec
, order
);
441 mutex_unlock(&nlk
->pg_vec_lock
);
445 mutex_unlock(&nlk
->pg_vec_lock
);
448 free_pg_vec(pg_vec
, order
, req
->nm_block_nr
);
453 static void netlink_mm_open(struct vm_area_struct
*vma
)
455 struct file
*file
= vma
->vm_file
;
456 struct socket
*sock
= file
->private_data
;
457 struct sock
*sk
= sock
->sk
;
460 atomic_inc(&nlk_sk(sk
)->mapped
);
463 static void netlink_mm_close(struct vm_area_struct
*vma
)
465 struct file
*file
= vma
->vm_file
;
466 struct socket
*sock
= file
->private_data
;
467 struct sock
*sk
= sock
->sk
;
470 atomic_dec(&nlk_sk(sk
)->mapped
);
473 static const struct vm_operations_struct netlink_mmap_ops
= {
474 .open
= netlink_mm_open
,
475 .close
= netlink_mm_close
,
478 static int netlink_mmap(struct file
*file
, struct socket
*sock
,
479 struct vm_area_struct
*vma
)
481 struct sock
*sk
= sock
->sk
;
482 struct netlink_sock
*nlk
= nlk_sk(sk
);
483 struct netlink_ring
*ring
;
484 unsigned long start
, size
, expected
;
491 mutex_lock(&nlk
->pg_vec_lock
);
494 for (ring
= &nlk
->rx_ring
; ring
<= &nlk
->tx_ring
; ring
++) {
495 if (ring
->pg_vec
== NULL
)
497 expected
+= ring
->pg_vec_len
* ring
->pg_vec_pages
* PAGE_SIZE
;
503 size
= vma
->vm_end
- vma
->vm_start
;
504 if (size
!= expected
)
507 start
= vma
->vm_start
;
508 for (ring
= &nlk
->rx_ring
; ring
<= &nlk
->tx_ring
; ring
++) {
509 if (ring
->pg_vec
== NULL
)
512 for (i
= 0; i
< ring
->pg_vec_len
; i
++) {
514 void *kaddr
= ring
->pg_vec
[i
];
517 for (pg_num
= 0; pg_num
< ring
->pg_vec_pages
; pg_num
++) {
518 page
= pgvec_to_page(kaddr
);
519 err
= vm_insert_page(vma
, start
, page
);
528 atomic_inc(&nlk
->mapped
);
529 vma
->vm_ops
= &netlink_mmap_ops
;
532 mutex_unlock(&nlk
->pg_vec_lock
);
536 static void netlink_frame_flush_dcache(const struct nl_mmap_hdr
*hdr
, unsigned int nm_len
)
538 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
539 struct page
*p_start
, *p_end
;
541 /* First page is flushed through netlink_{get,set}_status */
542 p_start
= pgvec_to_page(hdr
+ PAGE_SIZE
);
543 p_end
= pgvec_to_page((void *)hdr
+ NL_MMAP_HDRLEN
+ nm_len
- 1);
544 while (p_start
<= p_end
) {
545 flush_dcache_page(p_start
);
551 static enum nl_mmap_status
netlink_get_status(const struct nl_mmap_hdr
*hdr
)
554 flush_dcache_page(pgvec_to_page(hdr
));
555 return hdr
->nm_status
;
558 static void netlink_set_status(struct nl_mmap_hdr
*hdr
,
559 enum nl_mmap_status status
)
562 hdr
->nm_status
= status
;
563 flush_dcache_page(pgvec_to_page(hdr
));
566 static struct nl_mmap_hdr
*
567 __netlink_lookup_frame(const struct netlink_ring
*ring
, unsigned int pos
)
569 unsigned int pg_vec_pos
, frame_off
;
571 pg_vec_pos
= pos
/ ring
->frames_per_block
;
572 frame_off
= pos
% ring
->frames_per_block
;
574 return ring
->pg_vec
[pg_vec_pos
] + (frame_off
* ring
->frame_size
);
577 static struct nl_mmap_hdr
*
578 netlink_lookup_frame(const struct netlink_ring
*ring
, unsigned int pos
,
579 enum nl_mmap_status status
)
581 struct nl_mmap_hdr
*hdr
;
583 hdr
= __netlink_lookup_frame(ring
, pos
);
584 if (netlink_get_status(hdr
) != status
)
590 static struct nl_mmap_hdr
*
591 netlink_current_frame(const struct netlink_ring
*ring
,
592 enum nl_mmap_status status
)
594 return netlink_lookup_frame(ring
, ring
->head
, status
);
597 static void netlink_increment_head(struct netlink_ring
*ring
)
599 ring
->head
= ring
->head
!= ring
->frame_max
? ring
->head
+ 1 : 0;
602 static void netlink_forward_ring(struct netlink_ring
*ring
)
604 unsigned int head
= ring
->head
;
605 const struct nl_mmap_hdr
*hdr
;
608 hdr
= __netlink_lookup_frame(ring
, ring
->head
);
609 if (hdr
->nm_status
== NL_MMAP_STATUS_UNUSED
)
611 if (hdr
->nm_status
!= NL_MMAP_STATUS_SKIP
)
613 netlink_increment_head(ring
);
614 } while (ring
->head
!= head
);
617 static bool netlink_has_valid_frame(struct netlink_ring
*ring
)
619 unsigned int head
= ring
->head
, pos
= head
;
620 const struct nl_mmap_hdr
*hdr
;
623 hdr
= __netlink_lookup_frame(ring
, pos
);
624 if (hdr
->nm_status
== NL_MMAP_STATUS_VALID
)
626 pos
= pos
!= 0 ? pos
- 1 : ring
->frame_max
;
627 } while (pos
!= head
);
632 static bool netlink_dump_space(struct netlink_sock
*nlk
)
634 struct netlink_ring
*ring
= &nlk
->rx_ring
;
635 struct nl_mmap_hdr
*hdr
;
638 hdr
= netlink_current_frame(ring
, NL_MMAP_STATUS_UNUSED
);
642 n
= ring
->head
+ ring
->frame_max
/ 2;
643 if (n
> ring
->frame_max
)
644 n
-= ring
->frame_max
;
646 hdr
= __netlink_lookup_frame(ring
, n
);
648 return hdr
->nm_status
== NL_MMAP_STATUS_UNUSED
;
651 static unsigned int netlink_poll(struct file
*file
, struct socket
*sock
,
654 struct sock
*sk
= sock
->sk
;
655 struct netlink_sock
*nlk
= nlk_sk(sk
);
659 if (nlk
->rx_ring
.pg_vec
!= NULL
) {
660 /* Memory mapped sockets don't call recvmsg(), so flow control
661 * for dumps is performed here. A dump is allowed to continue
662 * if at least half the ring is unused.
664 while (nlk
->cb_running
&& netlink_dump_space(nlk
)) {
665 err
= netlink_dump(sk
);
668 sk
->sk_error_report(sk
);
672 netlink_rcv_wake(sk
);
675 mask
= datagram_poll(file
, sock
, wait
);
677 spin_lock_bh(&sk
->sk_receive_queue
.lock
);
678 if (nlk
->rx_ring
.pg_vec
) {
679 if (netlink_has_valid_frame(&nlk
->rx_ring
))
680 mask
|= POLLIN
| POLLRDNORM
;
682 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
684 spin_lock_bh(&sk
->sk_write_queue
.lock
);
685 if (nlk
->tx_ring
.pg_vec
) {
686 if (netlink_current_frame(&nlk
->tx_ring
, NL_MMAP_STATUS_UNUSED
))
687 mask
|= POLLOUT
| POLLWRNORM
;
689 spin_unlock_bh(&sk
->sk_write_queue
.lock
);
694 static struct nl_mmap_hdr
*netlink_mmap_hdr(struct sk_buff
*skb
)
696 return (struct nl_mmap_hdr
*)(skb
->head
- NL_MMAP_HDRLEN
);
699 static void netlink_ring_setup_skb(struct sk_buff
*skb
, struct sock
*sk
,
700 struct netlink_ring
*ring
,
701 struct nl_mmap_hdr
*hdr
)
706 size
= ring
->frame_size
- NL_MMAP_HDRLEN
;
707 data
= (void *)hdr
+ NL_MMAP_HDRLEN
;
711 skb_reset_tail_pointer(skb
);
712 skb
->end
= skb
->tail
+ size
;
715 skb
->destructor
= netlink_skb_destructor
;
716 NETLINK_CB(skb
).flags
|= NETLINK_SKB_MMAPED
;
717 NETLINK_CB(skb
).sk
= sk
;
720 static int netlink_mmap_sendmsg(struct sock
*sk
, struct msghdr
*msg
,
721 u32 dst_portid
, u32 dst_group
,
722 struct scm_cookie
*scm
)
724 struct netlink_sock
*nlk
= nlk_sk(sk
);
725 struct netlink_ring
*ring
;
726 struct nl_mmap_hdr
*hdr
;
729 int err
= 0, len
= 0;
731 mutex_lock(&nlk
->pg_vec_lock
);
733 ring
= &nlk
->tx_ring
;
734 maxlen
= ring
->frame_size
- NL_MMAP_HDRLEN
;
739 hdr
= netlink_current_frame(ring
, NL_MMAP_STATUS_VALID
);
741 if (!(msg
->msg_flags
& MSG_DONTWAIT
) &&
742 atomic_read(&nlk
->tx_ring
.pending
))
747 nm_len
= ACCESS_ONCE(hdr
->nm_len
);
748 if (nm_len
> maxlen
) {
753 netlink_frame_flush_dcache(hdr
, nm_len
);
755 skb
= alloc_skb(nm_len
, GFP_KERNEL
);
760 __skb_put(skb
, nm_len
);
761 memcpy(skb
->data
, (void *)hdr
+ NL_MMAP_HDRLEN
, nm_len
);
762 netlink_set_status(hdr
, NL_MMAP_STATUS_UNUSED
);
764 netlink_increment_head(ring
);
766 NETLINK_CB(skb
).portid
= nlk
->portid
;
767 NETLINK_CB(skb
).dst_group
= dst_group
;
768 NETLINK_CB(skb
).creds
= scm
->creds
;
770 err
= security_netlink_send(sk
, skb
);
776 if (unlikely(dst_group
)) {
777 atomic_inc(&skb
->users
);
778 netlink_broadcast(sk
, skb
, dst_portid
, dst_group
,
781 err
= netlink_unicast(sk
, skb
, dst_portid
,
782 msg
->msg_flags
& MSG_DONTWAIT
);
787 } while (hdr
!= NULL
||
788 (!(msg
->msg_flags
& MSG_DONTWAIT
) &&
789 atomic_read(&nlk
->tx_ring
.pending
)));
794 mutex_unlock(&nlk
->pg_vec_lock
);
798 static void netlink_queue_mmaped_skb(struct sock
*sk
, struct sk_buff
*skb
)
800 struct nl_mmap_hdr
*hdr
;
802 hdr
= netlink_mmap_hdr(skb
);
803 hdr
->nm_len
= skb
->len
;
804 hdr
->nm_group
= NETLINK_CB(skb
).dst_group
;
805 hdr
->nm_pid
= NETLINK_CB(skb
).creds
.pid
;
806 hdr
->nm_uid
= from_kuid(sk_user_ns(sk
), NETLINK_CB(skb
).creds
.uid
);
807 hdr
->nm_gid
= from_kgid(sk_user_ns(sk
), NETLINK_CB(skb
).creds
.gid
);
808 netlink_frame_flush_dcache(hdr
, hdr
->nm_len
);
809 netlink_set_status(hdr
, NL_MMAP_STATUS_VALID
);
811 NETLINK_CB(skb
).flags
|= NETLINK_SKB_DELIVERED
;
815 static void netlink_ring_set_copied(struct sock
*sk
, struct sk_buff
*skb
)
817 struct netlink_sock
*nlk
= nlk_sk(sk
);
818 struct netlink_ring
*ring
= &nlk
->rx_ring
;
819 struct nl_mmap_hdr
*hdr
;
821 spin_lock_bh(&sk
->sk_receive_queue
.lock
);
822 hdr
= netlink_current_frame(ring
, NL_MMAP_STATUS_UNUSED
);
824 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
829 netlink_increment_head(ring
);
830 __skb_queue_tail(&sk
->sk_receive_queue
, skb
);
831 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
833 hdr
->nm_len
= skb
->len
;
834 hdr
->nm_group
= NETLINK_CB(skb
).dst_group
;
835 hdr
->nm_pid
= NETLINK_CB(skb
).creds
.pid
;
836 hdr
->nm_uid
= from_kuid(sk_user_ns(sk
), NETLINK_CB(skb
).creds
.uid
);
837 hdr
->nm_gid
= from_kgid(sk_user_ns(sk
), NETLINK_CB(skb
).creds
.gid
);
838 netlink_set_status(hdr
, NL_MMAP_STATUS_COPY
);
841 #else /* CONFIG_NETLINK_MMAP */
842 #define netlink_skb_is_mmaped(skb) false
843 #define netlink_rx_is_mmaped(sk) false
844 #define netlink_tx_is_mmaped(sk) false
845 #define netlink_mmap sock_no_mmap
846 #define netlink_poll datagram_poll
847 #define netlink_mmap_sendmsg(sk, msg, dst_portid, dst_group, scm) 0
848 #endif /* CONFIG_NETLINK_MMAP */
850 static void netlink_skb_destructor(struct sk_buff
*skb
)
852 #ifdef CONFIG_NETLINK_MMAP
853 struct nl_mmap_hdr
*hdr
;
854 struct netlink_ring
*ring
;
857 /* If a packet from the kernel to userspace was freed because of an
858 * error without being delivered to userspace, the kernel must reset
859 * the status. In the direction userspace to kernel, the status is
860 * always reset here after the packet was processed and freed.
862 if (netlink_skb_is_mmaped(skb
)) {
863 hdr
= netlink_mmap_hdr(skb
);
864 sk
= NETLINK_CB(skb
).sk
;
866 if (NETLINK_CB(skb
).flags
& NETLINK_SKB_TX
) {
867 netlink_set_status(hdr
, NL_MMAP_STATUS_UNUSED
);
868 ring
= &nlk_sk(sk
)->tx_ring
;
870 if (!(NETLINK_CB(skb
).flags
& NETLINK_SKB_DELIVERED
)) {
872 netlink_set_status(hdr
, NL_MMAP_STATUS_VALID
);
874 ring
= &nlk_sk(sk
)->rx_ring
;
877 WARN_ON(atomic_read(&ring
->pending
) == 0);
878 atomic_dec(&ring
->pending
);
884 if (is_vmalloc_addr(skb
->head
)) {
886 !atomic_dec_return(&(skb_shinfo(skb
)->dataref
)))
895 static void netlink_skb_set_owner_r(struct sk_buff
*skb
, struct sock
*sk
)
897 WARN_ON(skb
->sk
!= NULL
);
899 skb
->destructor
= netlink_skb_destructor
;
900 atomic_add(skb
->truesize
, &sk
->sk_rmem_alloc
);
901 sk_mem_charge(sk
, skb
->truesize
);
904 static void netlink_sock_destruct(struct sock
*sk
)
906 struct netlink_sock
*nlk
= nlk_sk(sk
);
908 if (nlk
->cb_running
) {
910 nlk
->cb
.done(&nlk
->cb
);
912 module_put(nlk
->cb
.module
);
913 kfree_skb(nlk
->cb
.skb
);
916 skb_queue_purge(&sk
->sk_receive_queue
);
917 #ifdef CONFIG_NETLINK_MMAP
919 struct nl_mmap_req req
;
921 memset(&req
, 0, sizeof(req
));
922 if (nlk
->rx_ring
.pg_vec
)
923 __netlink_set_ring(sk
, &req
, false, NULL
, 0);
924 memset(&req
, 0, sizeof(req
));
925 if (nlk
->tx_ring
.pg_vec
)
926 __netlink_set_ring(sk
, &req
, true, NULL
, 0);
928 #endif /* CONFIG_NETLINK_MMAP */
930 if (!sock_flag(sk
, SOCK_DEAD
)) {
931 printk(KERN_ERR
"Freeing alive netlink socket %p\n", sk
);
935 WARN_ON(atomic_read(&sk
->sk_rmem_alloc
));
936 WARN_ON(atomic_read(&sk
->sk_wmem_alloc
));
937 WARN_ON(nlk_sk(sk
)->groups
);
940 /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on
941 * SMP. Look, when several writers sleep and reader wakes them up, all but one
942 * immediately hit write lock and grab all the cpus. Exclusive sleep solves
943 * this, _but_ remember, it adds useless work on UP machines.
946 void netlink_table_grab(void)
947 __acquires(nl_table_lock
)
951 write_lock_irq(&nl_table_lock
);
953 if (atomic_read(&nl_table_users
)) {
954 DECLARE_WAITQUEUE(wait
, current
);
956 add_wait_queue_exclusive(&nl_table_wait
, &wait
);
958 set_current_state(TASK_UNINTERRUPTIBLE
);
959 if (atomic_read(&nl_table_users
) == 0)
961 write_unlock_irq(&nl_table_lock
);
963 write_lock_irq(&nl_table_lock
);
966 __set_current_state(TASK_RUNNING
);
967 remove_wait_queue(&nl_table_wait
, &wait
);
971 void netlink_table_ungrab(void)
972 __releases(nl_table_lock
)
974 write_unlock_irq(&nl_table_lock
);
975 wake_up(&nl_table_wait
);
979 netlink_lock_table(void)
981 /* read_lock() synchronizes us to netlink_table_grab */
983 read_lock(&nl_table_lock
);
984 atomic_inc(&nl_table_users
);
985 read_unlock(&nl_table_lock
);
989 netlink_unlock_table(void)
991 if (atomic_dec_and_test(&nl_table_users
))
992 wake_up(&nl_table_wait
);
995 struct netlink_compare_arg
1001 /* Doing sizeof directly may yield 4 extra bytes on 64-bit. */
1002 #define netlink_compare_arg_len \
1003 (offsetof(struct netlink_compare_arg, portid) + sizeof(u32))
1005 static inline int netlink_compare(struct rhashtable_compare_arg
*arg
,
1008 const struct netlink_compare_arg
*x
= arg
->key
;
1009 const struct netlink_sock
*nlk
= ptr
;
1011 return nlk
->portid
!= x
->portid
||
1012 !net_eq(sock_net(&nlk
->sk
), read_pnet(&x
->pnet
));
1015 static void netlink_compare_arg_init(struct netlink_compare_arg
*arg
,
1016 struct net
*net
, u32 portid
)
1018 memset(arg
, 0, sizeof(*arg
));
1019 write_pnet(&arg
->pnet
, net
);
1020 arg
->portid
= portid
;
1023 static struct sock
*__netlink_lookup(struct netlink_table
*table
, u32 portid
,
1026 struct netlink_compare_arg arg
;
1028 netlink_compare_arg_init(&arg
, net
, portid
);
1029 return rhashtable_lookup_fast(&table
->hash
, &arg
,
1030 netlink_rhashtable_params
);
1033 static int __netlink_insert(struct netlink_table
*table
, struct sock
*sk
)
1035 struct netlink_compare_arg arg
;
1037 netlink_compare_arg_init(&arg
, sock_net(sk
), nlk_sk(sk
)->portid
);
1038 return rhashtable_lookup_insert_key(&table
->hash
, &arg
,
1040 netlink_rhashtable_params
);
1043 static struct sock
*netlink_lookup(struct net
*net
, int protocol
, u32 portid
)
1045 struct netlink_table
*table
= &nl_table
[protocol
];
1049 sk
= __netlink_lookup(table
, portid
, net
);
1057 static const struct proto_ops netlink_ops
;
1060 netlink_update_listeners(struct sock
*sk
)
1062 struct netlink_table
*tbl
= &nl_table
[sk
->sk_protocol
];
1065 struct listeners
*listeners
;
1067 listeners
= nl_deref_protected(tbl
->listeners
);
1071 for (i
= 0; i
< NLGRPLONGS(tbl
->groups
); i
++) {
1073 sk_for_each_bound(sk
, &tbl
->mc_list
) {
1074 if (i
< NLGRPLONGS(nlk_sk(sk
)->ngroups
))
1075 mask
|= nlk_sk(sk
)->groups
[i
];
1077 listeners
->masks
[i
] = mask
;
1079 /* this function is only called with the netlink table "grabbed", which
1080 * makes sure updates are visible before bind or setsockopt return. */
1083 static int netlink_insert(struct sock
*sk
, u32 portid
)
1085 struct netlink_table
*table
= &nl_table
[sk
->sk_protocol
];
1091 if (nlk_sk(sk
)->portid
)
1095 if (BITS_PER_LONG
> 32 &&
1096 unlikely(atomic_read(&table
->hash
.nelems
) >= UINT_MAX
))
1099 nlk_sk(sk
)->portid
= portid
;
1102 err
= __netlink_insert(table
, sk
);
1104 /* In case the hashtable backend returns with -EBUSY
1105 * from here, it must not escape to the caller.
1107 if (unlikely(err
== -EBUSY
))
1111 nlk_sk(sk
)->portid
= 0;
1120 static void netlink_remove(struct sock
*sk
)
1122 struct netlink_table
*table
;
1124 table
= &nl_table
[sk
->sk_protocol
];
1125 if (!rhashtable_remove_fast(&table
->hash
, &nlk_sk(sk
)->node
,
1126 netlink_rhashtable_params
)) {
1127 WARN_ON(atomic_read(&sk
->sk_refcnt
) == 1);
1131 netlink_table_grab();
1132 if (nlk_sk(sk
)->subscriptions
) {
1133 __sk_del_bind_node(sk
);
1134 netlink_update_listeners(sk
);
1136 if (sk
->sk_protocol
== NETLINK_GENERIC
)
1137 atomic_inc(&genl_sk_destructing_cnt
);
1138 netlink_table_ungrab();
1141 static struct proto netlink_proto
= {
1143 .owner
= THIS_MODULE
,
1144 .obj_size
= sizeof(struct netlink_sock
),
1147 static int __netlink_create(struct net
*net
, struct socket
*sock
,
1148 struct mutex
*cb_mutex
, int protocol
,
1152 struct netlink_sock
*nlk
;
1154 sock
->ops
= &netlink_ops
;
1156 sk
= sk_alloc(net
, PF_NETLINK
, GFP_KERNEL
, &netlink_proto
, kern
);
1160 sock_init_data(sock
, sk
);
1164 nlk
->cb_mutex
= cb_mutex
;
1166 nlk
->cb_mutex
= &nlk
->cb_def_mutex
;
1167 mutex_init(nlk
->cb_mutex
);
1169 init_waitqueue_head(&nlk
->wait
);
1170 #ifdef CONFIG_NETLINK_MMAP
1171 mutex_init(&nlk
->pg_vec_lock
);
1174 sk
->sk_destruct
= netlink_sock_destruct
;
1175 sk
->sk_protocol
= protocol
;
1179 static int netlink_create(struct net
*net
, struct socket
*sock
, int protocol
,
1182 struct module
*module
= NULL
;
1183 struct mutex
*cb_mutex
;
1184 struct netlink_sock
*nlk
;
1185 int (*bind
)(struct net
*net
, int group
);
1186 void (*unbind
)(struct net
*net
, int group
);
1189 sock
->state
= SS_UNCONNECTED
;
1191 if (sock
->type
!= SOCK_RAW
&& sock
->type
!= SOCK_DGRAM
)
1192 return -ESOCKTNOSUPPORT
;
1194 if (protocol
< 0 || protocol
>= MAX_LINKS
)
1195 return -EPROTONOSUPPORT
;
1197 netlink_lock_table();
1198 #ifdef CONFIG_MODULES
1199 if (!nl_table
[protocol
].registered
) {
1200 netlink_unlock_table();
1201 request_module("net-pf-%d-proto-%d", PF_NETLINK
, protocol
);
1202 netlink_lock_table();
1205 if (nl_table
[protocol
].registered
&&
1206 try_module_get(nl_table
[protocol
].module
))
1207 module
= nl_table
[protocol
].module
;
1209 err
= -EPROTONOSUPPORT
;
1210 cb_mutex
= nl_table
[protocol
].cb_mutex
;
1211 bind
= nl_table
[protocol
].bind
;
1212 unbind
= nl_table
[protocol
].unbind
;
1213 netlink_unlock_table();
1218 err
= __netlink_create(net
, sock
, cb_mutex
, protocol
, kern
);
1223 sock_prot_inuse_add(net
, &netlink_proto
, 1);
1226 nlk
= nlk_sk(sock
->sk
);
1227 nlk
->module
= module
;
1228 nlk
->netlink_bind
= bind
;
1229 nlk
->netlink_unbind
= unbind
;
1238 static void deferred_put_nlk_sk(struct rcu_head
*head
)
1240 struct netlink_sock
*nlk
= container_of(head
, struct netlink_sock
, rcu
);
1245 static int netlink_release(struct socket
*sock
)
1247 struct sock
*sk
= sock
->sk
;
1248 struct netlink_sock
*nlk
;
1258 * OK. Socket is unlinked, any packets that arrive now
1262 /* must not acquire netlink_table_lock in any way again before unbind
1263 * and notifying genetlink is done as otherwise it might deadlock
1265 if (nlk
->netlink_unbind
) {
1268 for (i
= 0; i
< nlk
->ngroups
; i
++)
1269 if (test_bit(i
, nlk
->groups
))
1270 nlk
->netlink_unbind(sock_net(sk
), i
+ 1);
1272 if (sk
->sk_protocol
== NETLINK_GENERIC
&&
1273 atomic_dec_return(&genl_sk_destructing_cnt
) == 0)
1274 wake_up(&genl_sk_destructing_waitq
);
1277 wake_up_interruptible_all(&nlk
->wait
);
1279 skb_queue_purge(&sk
->sk_write_queue
);
1282 struct netlink_notify n
= {
1283 .net
= sock_net(sk
),
1284 .protocol
= sk
->sk_protocol
,
1285 .portid
= nlk
->portid
,
1287 atomic_notifier_call_chain(&netlink_chain
,
1288 NETLINK_URELEASE
, &n
);
1291 module_put(nlk
->module
);
1293 if (netlink_is_kernel(sk
)) {
1294 netlink_table_grab();
1295 BUG_ON(nl_table
[sk
->sk_protocol
].registered
== 0);
1296 if (--nl_table
[sk
->sk_protocol
].registered
== 0) {
1297 struct listeners
*old
;
1299 old
= nl_deref_protected(nl_table
[sk
->sk_protocol
].listeners
);
1300 RCU_INIT_POINTER(nl_table
[sk
->sk_protocol
].listeners
, NULL
);
1301 kfree_rcu(old
, rcu
);
1302 nl_table
[sk
->sk_protocol
].module
= NULL
;
1303 nl_table
[sk
->sk_protocol
].bind
= NULL
;
1304 nl_table
[sk
->sk_protocol
].unbind
= NULL
;
1305 nl_table
[sk
->sk_protocol
].flags
= 0;
1306 nl_table
[sk
->sk_protocol
].registered
= 0;
1308 netlink_table_ungrab();
1315 sock_prot_inuse_add(sock_net(sk
), &netlink_proto
, -1);
1317 call_rcu(&nlk
->rcu
, deferred_put_nlk_sk
);
1321 static int netlink_autobind(struct socket
*sock
)
1323 struct sock
*sk
= sock
->sk
;
1324 struct net
*net
= sock_net(sk
);
1325 struct netlink_table
*table
= &nl_table
[sk
->sk_protocol
];
1326 s32 portid
= task_tgid_vnr(current
);
1334 ok
= !__netlink_lookup(table
, portid
, net
);
1337 /* Bind collision, search negative portid values. */
1339 /* rover will be in range [S32_MIN, -4097] */
1340 rover
= S32_MIN
+ prandom_u32_max(-4096 - S32_MIN
);
1341 else if (rover
>= -4096)
1347 err
= netlink_insert(sk
, portid
);
1348 if (err
== -EADDRINUSE
)
1351 /* If 2 threads race to autobind, that is fine. */
1359 * __netlink_ns_capable - General netlink message capability test
1360 * @nsp: NETLINK_CB of the socket buffer holding a netlink command from userspace.
1361 * @user_ns: The user namespace of the capability to use
1362 * @cap: The capability to use
1364 * Test to see if the opener of the socket we received the message
1365 * from had when the netlink socket was created and the sender of the
1366 * message has has the capability @cap in the user namespace @user_ns.
1368 bool __netlink_ns_capable(const struct netlink_skb_parms
*nsp
,
1369 struct user_namespace
*user_ns
, int cap
)
1371 return ((nsp
->flags
& NETLINK_SKB_DST
) ||
1372 file_ns_capable(nsp
->sk
->sk_socket
->file
, user_ns
, cap
)) &&
1373 ns_capable(user_ns
, cap
);
1375 EXPORT_SYMBOL(__netlink_ns_capable
);
1378 * netlink_ns_capable - General netlink message capability test
1379 * @skb: socket buffer holding a netlink command from userspace
1380 * @user_ns: The user namespace of the capability to use
1381 * @cap: The capability to use
1383 * Test to see if the opener of the socket we received the message
1384 * from had when the netlink socket was created and the sender of the
1385 * message has has the capability @cap in the user namespace @user_ns.
1387 bool netlink_ns_capable(const struct sk_buff
*skb
,
1388 struct user_namespace
*user_ns
, int cap
)
1390 return __netlink_ns_capable(&NETLINK_CB(skb
), user_ns
, cap
);
1392 EXPORT_SYMBOL(netlink_ns_capable
);
1395 * netlink_capable - Netlink global message capability test
1396 * @skb: socket buffer holding a netlink command from userspace
1397 * @cap: The capability to use
1399 * Test to see if the opener of the socket we received the message
1400 * from had when the netlink socket was created and the sender of the
1401 * message has has the capability @cap in all user namespaces.
1403 bool netlink_capable(const struct sk_buff
*skb
, int cap
)
1405 return netlink_ns_capable(skb
, &init_user_ns
, cap
);
1407 EXPORT_SYMBOL(netlink_capable
);
1410 * netlink_net_capable - Netlink network namespace message capability test
1411 * @skb: socket buffer holding a netlink command from userspace
1412 * @cap: The capability to use
1414 * Test to see if the opener of the socket we received the message
1415 * from had when the netlink socket was created and the sender of the
1416 * message has has the capability @cap over the network namespace of
1417 * the socket we received the message from.
1419 bool netlink_net_capable(const struct sk_buff
*skb
, int cap
)
1421 return netlink_ns_capable(skb
, sock_net(skb
->sk
)->user_ns
, cap
);
1423 EXPORT_SYMBOL(netlink_net_capable
);
1425 static inline int netlink_allowed(const struct socket
*sock
, unsigned int flag
)
1427 return (nl_table
[sock
->sk
->sk_protocol
].flags
& flag
) ||
1428 ns_capable(sock_net(sock
->sk
)->user_ns
, CAP_NET_ADMIN
);
1432 netlink_update_subscriptions(struct sock
*sk
, unsigned int subscriptions
)
1434 struct netlink_sock
*nlk
= nlk_sk(sk
);
1436 if (nlk
->subscriptions
&& !subscriptions
)
1437 __sk_del_bind_node(sk
);
1438 else if (!nlk
->subscriptions
&& subscriptions
)
1439 sk_add_bind_node(sk
, &nl_table
[sk
->sk_protocol
].mc_list
);
1440 nlk
->subscriptions
= subscriptions
;
1443 static int netlink_realloc_groups(struct sock
*sk
)
1445 struct netlink_sock
*nlk
= nlk_sk(sk
);
1446 unsigned int groups
;
1447 unsigned long *new_groups
;
1450 netlink_table_grab();
1452 groups
= nl_table
[sk
->sk_protocol
].groups
;
1453 if (!nl_table
[sk
->sk_protocol
].registered
) {
1458 if (nlk
->ngroups
>= groups
)
1461 new_groups
= krealloc(nlk
->groups
, NLGRPSZ(groups
), GFP_ATOMIC
);
1462 if (new_groups
== NULL
) {
1466 memset((char *)new_groups
+ NLGRPSZ(nlk
->ngroups
), 0,
1467 NLGRPSZ(groups
) - NLGRPSZ(nlk
->ngroups
));
1469 nlk
->groups
= new_groups
;
1470 nlk
->ngroups
= groups
;
1472 netlink_table_ungrab();
1476 static void netlink_undo_bind(int group
, long unsigned int groups
,
1479 struct netlink_sock
*nlk
= nlk_sk(sk
);
1482 if (!nlk
->netlink_unbind
)
1485 for (undo
= 0; undo
< group
; undo
++)
1486 if (test_bit(undo
, &groups
))
1487 nlk
->netlink_unbind(sock_net(sk
), undo
+ 1);
1490 static int netlink_bind(struct socket
*sock
, struct sockaddr
*addr
,
1493 struct sock
*sk
= sock
->sk
;
1494 struct net
*net
= sock_net(sk
);
1495 struct netlink_sock
*nlk
= nlk_sk(sk
);
1496 struct sockaddr_nl
*nladdr
= (struct sockaddr_nl
*)addr
;
1498 long unsigned int groups
= nladdr
->nl_groups
;
1500 if (addr_len
< sizeof(struct sockaddr_nl
))
1503 if (nladdr
->nl_family
!= AF_NETLINK
)
1506 /* Only superuser is allowed to listen multicasts */
1508 if (!netlink_allowed(sock
, NL_CFG_F_NONROOT_RECV
))
1510 err
= netlink_realloc_groups(sk
);
1516 if (nladdr
->nl_pid
!= nlk
->portid
)
1519 if (nlk
->netlink_bind
&& groups
) {
1522 for (group
= 0; group
< nlk
->ngroups
; group
++) {
1523 if (!test_bit(group
, &groups
))
1525 err
= nlk
->netlink_bind(net
, group
+ 1);
1528 netlink_undo_bind(group
, groups
, sk
);
1534 err
= nladdr
->nl_pid
?
1535 netlink_insert(sk
, nladdr
->nl_pid
) :
1536 netlink_autobind(sock
);
1538 netlink_undo_bind(nlk
->ngroups
, groups
, sk
);
1543 if (!groups
&& (nlk
->groups
== NULL
|| !(u32
)nlk
->groups
[0]))
1546 netlink_table_grab();
1547 netlink_update_subscriptions(sk
, nlk
->subscriptions
+
1549 hweight32(nlk
->groups
[0]));
1550 nlk
->groups
[0] = (nlk
->groups
[0] & ~0xffffffffUL
) | groups
;
1551 netlink_update_listeners(sk
);
1552 netlink_table_ungrab();
1557 static int netlink_connect(struct socket
*sock
, struct sockaddr
*addr
,
1558 int alen
, int flags
)
1561 struct sock
*sk
= sock
->sk
;
1562 struct netlink_sock
*nlk
= nlk_sk(sk
);
1563 struct sockaddr_nl
*nladdr
= (struct sockaddr_nl
*)addr
;
1565 if (alen
< sizeof(addr
->sa_family
))
1568 if (addr
->sa_family
== AF_UNSPEC
) {
1569 sk
->sk_state
= NETLINK_UNCONNECTED
;
1570 nlk
->dst_portid
= 0;
1574 if (addr
->sa_family
!= AF_NETLINK
)
1577 if ((nladdr
->nl_groups
|| nladdr
->nl_pid
) &&
1578 !netlink_allowed(sock
, NL_CFG_F_NONROOT_SEND
))
1582 err
= netlink_autobind(sock
);
1585 sk
->sk_state
= NETLINK_CONNECTED
;
1586 nlk
->dst_portid
= nladdr
->nl_pid
;
1587 nlk
->dst_group
= ffs(nladdr
->nl_groups
);
1593 static int netlink_getname(struct socket
*sock
, struct sockaddr
*addr
,
1594 int *addr_len
, int peer
)
1596 struct sock
*sk
= sock
->sk
;
1597 struct netlink_sock
*nlk
= nlk_sk(sk
);
1598 DECLARE_SOCKADDR(struct sockaddr_nl
*, nladdr
, addr
);
1600 nladdr
->nl_family
= AF_NETLINK
;
1602 *addr_len
= sizeof(*nladdr
);
1605 nladdr
->nl_pid
= nlk
->dst_portid
;
1606 nladdr
->nl_groups
= netlink_group_mask(nlk
->dst_group
);
1608 nladdr
->nl_pid
= nlk
->portid
;
1609 nladdr
->nl_groups
= nlk
->groups
? nlk
->groups
[0] : 0;
1614 static struct sock
*netlink_getsockbyportid(struct sock
*ssk
, u32 portid
)
1617 struct netlink_sock
*nlk
;
1619 sock
= netlink_lookup(sock_net(ssk
), ssk
->sk_protocol
, portid
);
1621 return ERR_PTR(-ECONNREFUSED
);
1623 /* Don't bother queuing skb if kernel socket has no input function */
1625 if (sock
->sk_state
== NETLINK_CONNECTED
&&
1626 nlk
->dst_portid
!= nlk_sk(ssk
)->portid
) {
1628 return ERR_PTR(-ECONNREFUSED
);
1633 struct sock
*netlink_getsockbyfilp(struct file
*filp
)
1635 struct inode
*inode
= file_inode(filp
);
1638 if (!S_ISSOCK(inode
->i_mode
))
1639 return ERR_PTR(-ENOTSOCK
);
1641 sock
= SOCKET_I(inode
)->sk
;
1642 if (sock
->sk_family
!= AF_NETLINK
)
1643 return ERR_PTR(-EINVAL
);
1649 static struct sk_buff
*netlink_alloc_large_skb(unsigned int size
,
1652 struct sk_buff
*skb
;
1655 if (size
<= NLMSG_GOODSIZE
|| broadcast
)
1656 return alloc_skb(size
, GFP_KERNEL
);
1658 size
= SKB_DATA_ALIGN(size
) +
1659 SKB_DATA_ALIGN(sizeof(struct skb_shared_info
));
1661 data
= vmalloc(size
);
1665 skb
= __build_skb(data
, size
);
1669 skb
->destructor
= netlink_skb_destructor
;
1675 * Attach a skb to a netlink socket.
1676 * The caller must hold a reference to the destination socket. On error, the
1677 * reference is dropped. The skb is not send to the destination, just all
1678 * all error checks are performed and memory in the queue is reserved.
1680 * < 0: error. skb freed, reference to sock dropped.
1682 * 1: repeat lookup - reference dropped while waiting for socket memory.
1684 int netlink_attachskb(struct sock
*sk
, struct sk_buff
*skb
,
1685 long *timeo
, struct sock
*ssk
)
1687 struct netlink_sock
*nlk
;
1691 if ((atomic_read(&sk
->sk_rmem_alloc
) > sk
->sk_rcvbuf
||
1692 test_bit(NETLINK_S_CONGESTED
, &nlk
->state
)) &&
1693 !netlink_skb_is_mmaped(skb
)) {
1694 DECLARE_WAITQUEUE(wait
, current
);
1696 if (!ssk
|| netlink_is_kernel(ssk
))
1697 netlink_overrun(sk
);
1703 __set_current_state(TASK_INTERRUPTIBLE
);
1704 add_wait_queue(&nlk
->wait
, &wait
);
1706 if ((atomic_read(&sk
->sk_rmem_alloc
) > sk
->sk_rcvbuf
||
1707 test_bit(NETLINK_S_CONGESTED
, &nlk
->state
)) &&
1708 !sock_flag(sk
, SOCK_DEAD
))
1709 *timeo
= schedule_timeout(*timeo
);
1711 __set_current_state(TASK_RUNNING
);
1712 remove_wait_queue(&nlk
->wait
, &wait
);
1715 if (signal_pending(current
)) {
1717 return sock_intr_errno(*timeo
);
1721 netlink_skb_set_owner_r(skb
, sk
);
1725 static int __netlink_sendskb(struct sock
*sk
, struct sk_buff
*skb
)
1729 netlink_deliver_tap(skb
);
1731 #ifdef CONFIG_NETLINK_MMAP
1732 if (netlink_skb_is_mmaped(skb
))
1733 netlink_queue_mmaped_skb(sk
, skb
);
1734 else if (netlink_rx_is_mmaped(sk
))
1735 netlink_ring_set_copied(sk
, skb
);
1737 #endif /* CONFIG_NETLINK_MMAP */
1738 skb_queue_tail(&sk
->sk_receive_queue
, skb
);
1739 sk
->sk_data_ready(sk
);
1743 int netlink_sendskb(struct sock
*sk
, struct sk_buff
*skb
)
1745 int len
= __netlink_sendskb(sk
, skb
);
1751 void netlink_detachskb(struct sock
*sk
, struct sk_buff
*skb
)
1757 static struct sk_buff
*netlink_trim(struct sk_buff
*skb
, gfp_t allocation
)
1761 WARN_ON(skb
->sk
!= NULL
);
1762 if (netlink_skb_is_mmaped(skb
))
1765 delta
= skb
->end
- skb
->tail
;
1766 if (is_vmalloc_addr(skb
->head
) || delta
* 2 < skb
->truesize
)
1769 if (skb_shared(skb
)) {
1770 struct sk_buff
*nskb
= skb_clone(skb
, allocation
);
1777 if (!pskb_expand_head(skb
, 0, -delta
, allocation
))
1778 skb
->truesize
-= delta
;
1783 static int netlink_unicast_kernel(struct sock
*sk
, struct sk_buff
*skb
,
1787 struct netlink_sock
*nlk
= nlk_sk(sk
);
1789 ret
= -ECONNREFUSED
;
1790 if (nlk
->netlink_rcv
!= NULL
) {
1792 netlink_skb_set_owner_r(skb
, sk
);
1793 NETLINK_CB(skb
).sk
= ssk
;
1794 netlink_deliver_tap_kernel(sk
, ssk
, skb
);
1795 nlk
->netlink_rcv(skb
);
1804 int netlink_unicast(struct sock
*ssk
, struct sk_buff
*skb
,
1805 u32 portid
, int nonblock
)
1811 skb
= netlink_trim(skb
, gfp_any());
1813 timeo
= sock_sndtimeo(ssk
, nonblock
);
1815 sk
= netlink_getsockbyportid(ssk
, portid
);
1820 if (netlink_is_kernel(sk
))
1821 return netlink_unicast_kernel(sk
, skb
, ssk
);
1823 if (sk_filter(sk
, skb
)) {
1830 err
= netlink_attachskb(sk
, skb
, &timeo
, ssk
);
1836 return netlink_sendskb(sk
, skb
);
1838 EXPORT_SYMBOL(netlink_unicast
);
1840 struct sk_buff
*netlink_alloc_skb(struct sock
*ssk
, unsigned int size
,
1841 u32 dst_portid
, gfp_t gfp_mask
)
1843 #ifdef CONFIG_NETLINK_MMAP
1844 struct sock
*sk
= NULL
;
1845 struct sk_buff
*skb
;
1846 struct netlink_ring
*ring
;
1847 struct nl_mmap_hdr
*hdr
;
1848 unsigned int maxlen
;
1850 sk
= netlink_getsockbyportid(ssk
, dst_portid
);
1854 ring
= &nlk_sk(sk
)->rx_ring
;
1855 /* fast-path without atomic ops for common case: non-mmaped receiver */
1856 if (ring
->pg_vec
== NULL
)
1859 if (ring
->frame_size
- NL_MMAP_HDRLEN
< size
)
1862 skb
= alloc_skb_head(gfp_mask
);
1866 spin_lock_bh(&sk
->sk_receive_queue
.lock
);
1867 /* check again under lock */
1868 if (ring
->pg_vec
== NULL
)
1871 /* check again under lock */
1872 maxlen
= ring
->frame_size
- NL_MMAP_HDRLEN
;
1876 netlink_forward_ring(ring
);
1877 hdr
= netlink_current_frame(ring
, NL_MMAP_STATUS_UNUSED
);
1880 netlink_ring_setup_skb(skb
, sk
, ring
, hdr
);
1881 netlink_set_status(hdr
, NL_MMAP_STATUS_RESERVED
);
1882 atomic_inc(&ring
->pending
);
1883 netlink_increment_head(ring
);
1885 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
1890 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
1891 netlink_overrun(sk
);
1898 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
1903 return alloc_skb(size
, gfp_mask
);
1905 EXPORT_SYMBOL_GPL(netlink_alloc_skb
);
1907 int netlink_has_listeners(struct sock
*sk
, unsigned int group
)
1910 struct listeners
*listeners
;
1912 BUG_ON(!netlink_is_kernel(sk
));
1915 listeners
= rcu_dereference(nl_table
[sk
->sk_protocol
].listeners
);
1917 if (listeners
&& group
- 1 < nl_table
[sk
->sk_protocol
].groups
)
1918 res
= test_bit(group
- 1, listeners
->masks
);
1924 EXPORT_SYMBOL_GPL(netlink_has_listeners
);
1926 static int netlink_broadcast_deliver(struct sock
*sk
, struct sk_buff
*skb
)
1928 struct netlink_sock
*nlk
= nlk_sk(sk
);
1930 if (atomic_read(&sk
->sk_rmem_alloc
) <= sk
->sk_rcvbuf
&&
1931 !test_bit(NETLINK_S_CONGESTED
, &nlk
->state
)) {
1932 netlink_skb_set_owner_r(skb
, sk
);
1933 __netlink_sendskb(sk
, skb
);
1934 return atomic_read(&sk
->sk_rmem_alloc
) > (sk
->sk_rcvbuf
>> 1);
1939 struct netlink_broadcast_data
{
1940 struct sock
*exclude_sk
;
1945 int delivery_failure
;
1949 struct sk_buff
*skb
, *skb2
;
1950 int (*tx_filter
)(struct sock
*dsk
, struct sk_buff
*skb
, void *data
);
1954 static void do_one_broadcast(struct sock
*sk
,
1955 struct netlink_broadcast_data
*p
)
1957 struct netlink_sock
*nlk
= nlk_sk(sk
);
1960 if (p
->exclude_sk
== sk
)
1963 if (nlk
->portid
== p
->portid
|| p
->group
- 1 >= nlk
->ngroups
||
1964 !test_bit(p
->group
- 1, nlk
->groups
))
1967 if (!net_eq(sock_net(sk
), p
->net
)) {
1968 if (!(nlk
->flags
& NETLINK_F_LISTEN_ALL_NSID
))
1971 if (!peernet_has_id(sock_net(sk
), p
->net
))
1974 if (!file_ns_capable(sk
->sk_socket
->file
, p
->net
->user_ns
,
1980 netlink_overrun(sk
);
1985 if (p
->skb2
== NULL
) {
1986 if (skb_shared(p
->skb
)) {
1987 p
->skb2
= skb_clone(p
->skb
, p
->allocation
);
1989 p
->skb2
= skb_get(p
->skb
);
1991 * skb ownership may have been set when
1992 * delivered to a previous socket.
1994 skb_orphan(p
->skb2
);
1997 if (p
->skb2
== NULL
) {
1998 netlink_overrun(sk
);
1999 /* Clone failed. Notify ALL listeners. */
2001 if (nlk
->flags
& NETLINK_F_BROADCAST_SEND_ERROR
)
2002 p
->delivery_failure
= 1;
2005 if (p
->tx_filter
&& p
->tx_filter(sk
, p
->skb2
, p
->tx_data
)) {
2010 if (sk_filter(sk
, p
->skb2
)) {
2015 NETLINK_CB(p
->skb2
).nsid
= peernet2id(sock_net(sk
), p
->net
);
2016 NETLINK_CB(p
->skb2
).nsid_is_set
= true;
2017 val
= netlink_broadcast_deliver(sk
, p
->skb2
);
2019 netlink_overrun(sk
);
2020 if (nlk
->flags
& NETLINK_F_BROADCAST_SEND_ERROR
)
2021 p
->delivery_failure
= 1;
2023 p
->congested
|= val
;
2031 int netlink_broadcast_filtered(struct sock
*ssk
, struct sk_buff
*skb
, u32 portid
,
2032 u32 group
, gfp_t allocation
,
2033 int (*filter
)(struct sock
*dsk
, struct sk_buff
*skb
, void *data
),
2036 struct net
*net
= sock_net(ssk
);
2037 struct netlink_broadcast_data info
;
2040 skb
= netlink_trim(skb
, allocation
);
2042 info
.exclude_sk
= ssk
;
2044 info
.portid
= portid
;
2047 info
.delivery_failure
= 0;
2050 info
.allocation
= allocation
;
2053 info
.tx_filter
= filter
;
2054 info
.tx_data
= filter_data
;
2056 /* While we sleep in clone, do not allow to change socket list */
2058 netlink_lock_table();
2060 sk_for_each_bound(sk
, &nl_table
[ssk
->sk_protocol
].mc_list
)
2061 do_one_broadcast(sk
, &info
);
2065 netlink_unlock_table();
2067 if (info
.delivery_failure
) {
2068 kfree_skb(info
.skb2
);
2071 consume_skb(info
.skb2
);
2073 if (info
.delivered
) {
2074 if (info
.congested
&& (allocation
& __GFP_WAIT
))
2080 EXPORT_SYMBOL(netlink_broadcast_filtered
);
2082 int netlink_broadcast(struct sock
*ssk
, struct sk_buff
*skb
, u32 portid
,
2083 u32 group
, gfp_t allocation
)
2085 return netlink_broadcast_filtered(ssk
, skb
, portid
, group
, allocation
,
2088 EXPORT_SYMBOL(netlink_broadcast
);
2090 struct netlink_set_err_data
{
2091 struct sock
*exclude_sk
;
2097 static int do_one_set_err(struct sock
*sk
, struct netlink_set_err_data
*p
)
2099 struct netlink_sock
*nlk
= nlk_sk(sk
);
2102 if (sk
== p
->exclude_sk
)
2105 if (!net_eq(sock_net(sk
), sock_net(p
->exclude_sk
)))
2108 if (nlk
->portid
== p
->portid
|| p
->group
- 1 >= nlk
->ngroups
||
2109 !test_bit(p
->group
- 1, nlk
->groups
))
2112 if (p
->code
== ENOBUFS
&& nlk
->flags
& NETLINK_F_RECV_NO_ENOBUFS
) {
2117 sk
->sk_err
= p
->code
;
2118 sk
->sk_error_report(sk
);
2124 * netlink_set_err - report error to broadcast listeners
2125 * @ssk: the kernel netlink socket, as returned by netlink_kernel_create()
2126 * @portid: the PORTID of a process that we want to skip (if any)
2127 * @group: the broadcast group that will notice the error
2128 * @code: error code, must be negative (as usual in kernelspace)
2130 * This function returns the number of broadcast listeners that have set the
2131 * NETLINK_NO_ENOBUFS socket option.
2133 int netlink_set_err(struct sock
*ssk
, u32 portid
, u32 group
, int code
)
2135 struct netlink_set_err_data info
;
2139 info
.exclude_sk
= ssk
;
2140 info
.portid
= portid
;
2142 /* sk->sk_err wants a positive error value */
2145 read_lock(&nl_table_lock
);
2147 sk_for_each_bound(sk
, &nl_table
[ssk
->sk_protocol
].mc_list
)
2148 ret
+= do_one_set_err(sk
, &info
);
2150 read_unlock(&nl_table_lock
);
2153 EXPORT_SYMBOL(netlink_set_err
);
2155 /* must be called with netlink table grabbed */
2156 static void netlink_update_socket_mc(struct netlink_sock
*nlk
,
2160 int old
, new = !!is_new
, subscriptions
;
2162 old
= test_bit(group
- 1, nlk
->groups
);
2163 subscriptions
= nlk
->subscriptions
- old
+ new;
2165 __set_bit(group
- 1, nlk
->groups
);
2167 __clear_bit(group
- 1, nlk
->groups
);
2168 netlink_update_subscriptions(&nlk
->sk
, subscriptions
);
2169 netlink_update_listeners(&nlk
->sk
);
2172 static int netlink_setsockopt(struct socket
*sock
, int level
, int optname
,
2173 char __user
*optval
, unsigned int optlen
)
2175 struct sock
*sk
= sock
->sk
;
2176 struct netlink_sock
*nlk
= nlk_sk(sk
);
2177 unsigned int val
= 0;
2180 if (level
!= SOL_NETLINK
)
2181 return -ENOPROTOOPT
;
2183 if (optname
!= NETLINK_RX_RING
&& optname
!= NETLINK_TX_RING
&&
2184 optlen
>= sizeof(int) &&
2185 get_user(val
, (unsigned int __user
*)optval
))
2189 case NETLINK_PKTINFO
:
2191 nlk
->flags
|= NETLINK_F_RECV_PKTINFO
;
2193 nlk
->flags
&= ~NETLINK_F_RECV_PKTINFO
;
2196 case NETLINK_ADD_MEMBERSHIP
:
2197 case NETLINK_DROP_MEMBERSHIP
: {
2198 if (!netlink_allowed(sock
, NL_CFG_F_NONROOT_RECV
))
2200 err
= netlink_realloc_groups(sk
);
2203 if (!val
|| val
- 1 >= nlk
->ngroups
)
2205 if (optname
== NETLINK_ADD_MEMBERSHIP
&& nlk
->netlink_bind
) {
2206 err
= nlk
->netlink_bind(sock_net(sk
), val
);
2210 netlink_table_grab();
2211 netlink_update_socket_mc(nlk
, val
,
2212 optname
== NETLINK_ADD_MEMBERSHIP
);
2213 netlink_table_ungrab();
2214 if (optname
== NETLINK_DROP_MEMBERSHIP
&& nlk
->netlink_unbind
)
2215 nlk
->netlink_unbind(sock_net(sk
), val
);
2220 case NETLINK_BROADCAST_ERROR
:
2222 nlk
->flags
|= NETLINK_F_BROADCAST_SEND_ERROR
;
2224 nlk
->flags
&= ~NETLINK_F_BROADCAST_SEND_ERROR
;
2227 case NETLINK_NO_ENOBUFS
:
2229 nlk
->flags
|= NETLINK_F_RECV_NO_ENOBUFS
;
2230 clear_bit(NETLINK_S_CONGESTED
, &nlk
->state
);
2231 wake_up_interruptible(&nlk
->wait
);
2233 nlk
->flags
&= ~NETLINK_F_RECV_NO_ENOBUFS
;
2237 #ifdef CONFIG_NETLINK_MMAP
2238 case NETLINK_RX_RING
:
2239 case NETLINK_TX_RING
: {
2240 struct nl_mmap_req req
;
2242 /* Rings might consume more memory than queue limits, require
2245 if (!capable(CAP_NET_ADMIN
))
2247 if (optlen
< sizeof(req
))
2249 if (copy_from_user(&req
, optval
, sizeof(req
)))
2251 err
= netlink_set_ring(sk
, &req
,
2252 optname
== NETLINK_TX_RING
);
2255 #endif /* CONFIG_NETLINK_MMAP */
2256 case NETLINK_LISTEN_ALL_NSID
:
2257 if (!ns_capable(sock_net(sk
)->user_ns
, CAP_NET_BROADCAST
))
2261 nlk
->flags
|= NETLINK_F_LISTEN_ALL_NSID
;
2263 nlk
->flags
&= ~NETLINK_F_LISTEN_ALL_NSID
;
2266 case NETLINK_CAP_ACK
:
2268 nlk
->flags
|= NETLINK_F_CAP_ACK
;
2270 nlk
->flags
&= ~NETLINK_F_CAP_ACK
;
2279 static int netlink_getsockopt(struct socket
*sock
, int level
, int optname
,
2280 char __user
*optval
, int __user
*optlen
)
2282 struct sock
*sk
= sock
->sk
;
2283 struct netlink_sock
*nlk
= nlk_sk(sk
);
2286 if (level
!= SOL_NETLINK
)
2287 return -ENOPROTOOPT
;
2289 if (get_user(len
, optlen
))
2295 case NETLINK_PKTINFO
:
2296 if (len
< sizeof(int))
2299 val
= nlk
->flags
& NETLINK_F_RECV_PKTINFO
? 1 : 0;
2300 if (put_user(len
, optlen
) ||
2301 put_user(val
, optval
))
2305 case NETLINK_BROADCAST_ERROR
:
2306 if (len
< sizeof(int))
2309 val
= nlk
->flags
& NETLINK_F_BROADCAST_SEND_ERROR
? 1 : 0;
2310 if (put_user(len
, optlen
) ||
2311 put_user(val
, optval
))
2315 case NETLINK_NO_ENOBUFS
:
2316 if (len
< sizeof(int))
2319 val
= nlk
->flags
& NETLINK_F_RECV_NO_ENOBUFS
? 1 : 0;
2320 if (put_user(len
, optlen
) ||
2321 put_user(val
, optval
))
2325 case NETLINK_LIST_MEMBERSHIPS
: {
2326 int pos
, idx
, shift
;
2329 netlink_table_grab();
2330 for (pos
= 0; pos
* 8 < nlk
->ngroups
; pos
+= sizeof(u32
)) {
2331 if (len
- pos
< sizeof(u32
))
2334 idx
= pos
/ sizeof(unsigned long);
2335 shift
= (pos
% sizeof(unsigned long)) * 8;
2336 if (put_user((u32
)(nlk
->groups
[idx
] >> shift
),
2337 (u32 __user
*)(optval
+ pos
))) {
2342 if (put_user(ALIGN(nlk
->ngroups
/ 8, sizeof(u32
)), optlen
))
2344 netlink_table_ungrab();
2347 case NETLINK_CAP_ACK
:
2348 if (len
< sizeof(int))
2351 val
= nlk
->flags
& NETLINK_F_CAP_ACK
? 1 : 0;
2352 if (put_user(len
, optlen
) ||
2353 put_user(val
, optval
))
2363 static void netlink_cmsg_recv_pktinfo(struct msghdr
*msg
, struct sk_buff
*skb
)
2365 struct nl_pktinfo info
;
2367 info
.group
= NETLINK_CB(skb
).dst_group
;
2368 put_cmsg(msg
, SOL_NETLINK
, NETLINK_PKTINFO
, sizeof(info
), &info
);
2371 static void netlink_cmsg_listen_all_nsid(struct sock
*sk
, struct msghdr
*msg
,
2372 struct sk_buff
*skb
)
2374 if (!NETLINK_CB(skb
).nsid_is_set
)
2377 put_cmsg(msg
, SOL_NETLINK
, NETLINK_LISTEN_ALL_NSID
, sizeof(int),
2378 &NETLINK_CB(skb
).nsid
);
2381 static int netlink_sendmsg(struct socket
*sock
, struct msghdr
*msg
, size_t len
)
2383 struct sock
*sk
= sock
->sk
;
2384 struct netlink_sock
*nlk
= nlk_sk(sk
);
2385 DECLARE_SOCKADDR(struct sockaddr_nl
*, addr
, msg
->msg_name
);
2388 struct sk_buff
*skb
;
2390 struct scm_cookie scm
;
2391 u32 netlink_skb_flags
= 0;
2393 if (msg
->msg_flags
&MSG_OOB
)
2396 err
= scm_send(sock
, msg
, &scm
, true);
2400 if (msg
->msg_namelen
) {
2402 if (addr
->nl_family
!= AF_NETLINK
)
2404 dst_portid
= addr
->nl_pid
;
2405 dst_group
= ffs(addr
->nl_groups
);
2407 if ((dst_group
|| dst_portid
) &&
2408 !netlink_allowed(sock
, NL_CFG_F_NONROOT_SEND
))
2410 netlink_skb_flags
|= NETLINK_SKB_DST
;
2412 dst_portid
= nlk
->dst_portid
;
2413 dst_group
= nlk
->dst_group
;
2417 err
= netlink_autobind(sock
);
2422 /* It's a really convoluted way for userland to ask for mmaped
2423 * sendmsg(), but that's what we've got...
2425 if (netlink_tx_is_mmaped(sk
) &&
2426 iter_is_iovec(&msg
->msg_iter
) &&
2427 msg
->msg_iter
.nr_segs
== 1 &&
2428 msg
->msg_iter
.iov
->iov_base
== NULL
) {
2429 err
= netlink_mmap_sendmsg(sk
, msg
, dst_portid
, dst_group
,
2435 if (len
> sk
->sk_sndbuf
- 32)
2438 skb
= netlink_alloc_large_skb(len
, dst_group
);
2442 NETLINK_CB(skb
).portid
= nlk
->portid
;
2443 NETLINK_CB(skb
).dst_group
= dst_group
;
2444 NETLINK_CB(skb
).creds
= scm
.creds
;
2445 NETLINK_CB(skb
).flags
= netlink_skb_flags
;
2448 if (memcpy_from_msg(skb_put(skb
, len
), msg
, len
)) {
2453 err
= security_netlink_send(sk
, skb
);
2460 atomic_inc(&skb
->users
);
2461 netlink_broadcast(sk
, skb
, dst_portid
, dst_group
, GFP_KERNEL
);
2463 err
= netlink_unicast(sk
, skb
, dst_portid
, msg
->msg_flags
&MSG_DONTWAIT
);
2470 static int netlink_recvmsg(struct socket
*sock
, struct msghdr
*msg
, size_t len
,
2473 struct scm_cookie scm
;
2474 struct sock
*sk
= sock
->sk
;
2475 struct netlink_sock
*nlk
= nlk_sk(sk
);
2476 int noblock
= flags
&MSG_DONTWAIT
;
2478 struct sk_buff
*skb
, *data_skb
;
2486 skb
= skb_recv_datagram(sk
, flags
, noblock
, &err
);
2492 #ifdef CONFIG_COMPAT_NETLINK_MESSAGES
2493 if (unlikely(skb_shinfo(skb
)->frag_list
)) {
2495 * If this skb has a frag_list, then here that means that we
2496 * will have to use the frag_list skb's data for compat tasks
2497 * and the regular skb's data for normal (non-compat) tasks.
2499 * If we need to send the compat skb, assign it to the
2500 * 'data_skb' variable so that it will be used below for data
2501 * copying. We keep 'skb' for everything else, including
2502 * freeing both later.
2504 if (flags
& MSG_CMSG_COMPAT
)
2505 data_skb
= skb_shinfo(skb
)->frag_list
;
2509 /* Record the max length of recvmsg() calls for future allocations */
2510 nlk
->max_recvmsg_len
= max(nlk
->max_recvmsg_len
, len
);
2511 nlk
->max_recvmsg_len
= min_t(size_t, nlk
->max_recvmsg_len
,
2514 copied
= data_skb
->len
;
2516 msg
->msg_flags
|= MSG_TRUNC
;
2520 skb_reset_transport_header(data_skb
);
2521 err
= skb_copy_datagram_msg(data_skb
, 0, msg
, copied
);
2523 if (msg
->msg_name
) {
2524 DECLARE_SOCKADDR(struct sockaddr_nl
*, addr
, msg
->msg_name
);
2525 addr
->nl_family
= AF_NETLINK
;
2527 addr
->nl_pid
= NETLINK_CB(skb
).portid
;
2528 addr
->nl_groups
= netlink_group_mask(NETLINK_CB(skb
).dst_group
);
2529 msg
->msg_namelen
= sizeof(*addr
);
2532 if (nlk
->flags
& NETLINK_F_RECV_PKTINFO
)
2533 netlink_cmsg_recv_pktinfo(msg
, skb
);
2534 if (nlk
->flags
& NETLINK_F_LISTEN_ALL_NSID
)
2535 netlink_cmsg_listen_all_nsid(sk
, msg
, skb
);
2537 memset(&scm
, 0, sizeof(scm
));
2538 scm
.creds
= *NETLINK_CREDS(skb
);
2539 if (flags
& MSG_TRUNC
)
2540 copied
= data_skb
->len
;
2542 skb_free_datagram(sk
, skb
);
2544 if (nlk
->cb_running
&&
2545 atomic_read(&sk
->sk_rmem_alloc
) <= sk
->sk_rcvbuf
/ 2) {
2546 ret
= netlink_dump(sk
);
2549 sk
->sk_error_report(sk
);
2553 scm_recv(sock
, msg
, &scm
, flags
);
2555 netlink_rcv_wake(sk
);
2556 return err
? : copied
;
2559 static void netlink_data_ready(struct sock
*sk
)
2565 * We export these functions to other modules. They provide a
2566 * complete set of kernel non-blocking support for message
2571 __netlink_kernel_create(struct net
*net
, int unit
, struct module
*module
,
2572 struct netlink_kernel_cfg
*cfg
)
2574 struct socket
*sock
;
2576 struct netlink_sock
*nlk
;
2577 struct listeners
*listeners
= NULL
;
2578 struct mutex
*cb_mutex
= cfg
? cfg
->cb_mutex
: NULL
;
2579 unsigned int groups
;
2583 if (unit
< 0 || unit
>= MAX_LINKS
)
2586 if (sock_create_lite(PF_NETLINK
, SOCK_DGRAM
, unit
, &sock
))
2589 if (__netlink_create(net
, sock
, cb_mutex
, unit
, 1) < 0)
2590 goto out_sock_release_nosk
;
2594 if (!cfg
|| cfg
->groups
< 32)
2597 groups
= cfg
->groups
;
2599 listeners
= kzalloc(sizeof(*listeners
) + NLGRPSZ(groups
), GFP_KERNEL
);
2601 goto out_sock_release
;
2603 sk
->sk_data_ready
= netlink_data_ready
;
2604 if (cfg
&& cfg
->input
)
2605 nlk_sk(sk
)->netlink_rcv
= cfg
->input
;
2607 if (netlink_insert(sk
, 0))
2608 goto out_sock_release
;
2611 nlk
->flags
|= NETLINK_F_KERNEL_SOCKET
;
2613 netlink_table_grab();
2614 if (!nl_table
[unit
].registered
) {
2615 nl_table
[unit
].groups
= groups
;
2616 rcu_assign_pointer(nl_table
[unit
].listeners
, listeners
);
2617 nl_table
[unit
].cb_mutex
= cb_mutex
;
2618 nl_table
[unit
].module
= module
;
2620 nl_table
[unit
].bind
= cfg
->bind
;
2621 nl_table
[unit
].unbind
= cfg
->unbind
;
2622 nl_table
[unit
].flags
= cfg
->flags
;
2624 nl_table
[unit
].compare
= cfg
->compare
;
2626 nl_table
[unit
].registered
= 1;
2629 nl_table
[unit
].registered
++;
2631 netlink_table_ungrab();
2636 netlink_kernel_release(sk
);
2639 out_sock_release_nosk
:
2643 EXPORT_SYMBOL(__netlink_kernel_create
);
2646 netlink_kernel_release(struct sock
*sk
)
2648 if (sk
== NULL
|| sk
->sk_socket
== NULL
)
2651 sock_release(sk
->sk_socket
);
2653 EXPORT_SYMBOL(netlink_kernel_release
);
2655 int __netlink_change_ngroups(struct sock
*sk
, unsigned int groups
)
2657 struct listeners
*new, *old
;
2658 struct netlink_table
*tbl
= &nl_table
[sk
->sk_protocol
];
2663 if (NLGRPSZ(tbl
->groups
) < NLGRPSZ(groups
)) {
2664 new = kzalloc(sizeof(*new) + NLGRPSZ(groups
), GFP_ATOMIC
);
2667 old
= nl_deref_protected(tbl
->listeners
);
2668 memcpy(new->masks
, old
->masks
, NLGRPSZ(tbl
->groups
));
2669 rcu_assign_pointer(tbl
->listeners
, new);
2671 kfree_rcu(old
, rcu
);
2673 tbl
->groups
= groups
;
2679 * netlink_change_ngroups - change number of multicast groups
2681 * This changes the number of multicast groups that are available
2682 * on a certain netlink family. Note that it is not possible to
2683 * change the number of groups to below 32. Also note that it does
2684 * not implicitly call netlink_clear_multicast_users() when the
2685 * number of groups is reduced.
2687 * @sk: The kernel netlink socket, as returned by netlink_kernel_create().
2688 * @groups: The new number of groups.
2690 int netlink_change_ngroups(struct sock
*sk
, unsigned int groups
)
2694 netlink_table_grab();
2695 err
= __netlink_change_ngroups(sk
, groups
);
2696 netlink_table_ungrab();
2701 void __netlink_clear_multicast_users(struct sock
*ksk
, unsigned int group
)
2704 struct netlink_table
*tbl
= &nl_table
[ksk
->sk_protocol
];
2706 sk_for_each_bound(sk
, &tbl
->mc_list
)
2707 netlink_update_socket_mc(nlk_sk(sk
), group
, 0);
2711 __nlmsg_put(struct sk_buff
*skb
, u32 portid
, u32 seq
, int type
, int len
, int flags
)
2713 struct nlmsghdr
*nlh
;
2714 int size
= nlmsg_msg_size(len
);
2716 nlh
= (struct nlmsghdr
*)skb_put(skb
, NLMSG_ALIGN(size
));
2717 nlh
->nlmsg_type
= type
;
2718 nlh
->nlmsg_len
= size
;
2719 nlh
->nlmsg_flags
= flags
;
2720 nlh
->nlmsg_pid
= portid
;
2721 nlh
->nlmsg_seq
= seq
;
2722 if (!__builtin_constant_p(size
) || NLMSG_ALIGN(size
) - size
!= 0)
2723 memset(nlmsg_data(nlh
) + len
, 0, NLMSG_ALIGN(size
) - size
);
2726 EXPORT_SYMBOL(__nlmsg_put
);
2729 * It looks a bit ugly.
2730 * It would be better to create kernel thread.
2733 static int netlink_dump(struct sock
*sk
)
2735 struct netlink_sock
*nlk
= nlk_sk(sk
);
2736 struct netlink_callback
*cb
;
2737 struct sk_buff
*skb
= NULL
;
2738 struct nlmsghdr
*nlh
;
2739 int len
, err
= -ENOBUFS
;
2742 mutex_lock(nlk
->cb_mutex
);
2743 if (!nlk
->cb_running
) {
2749 alloc_size
= max_t(int, cb
->min_dump_alloc
, NLMSG_GOODSIZE
);
2751 if (!netlink_rx_is_mmaped(sk
) &&
2752 atomic_read(&sk
->sk_rmem_alloc
) >= sk
->sk_rcvbuf
)
2755 /* NLMSG_GOODSIZE is small to avoid high order allocations being
2756 * required, but it makes sense to _attempt_ a 16K bytes allocation
2757 * to reduce number of system calls on dump operations, if user
2758 * ever provided a big enough buffer.
2760 if (alloc_size
< nlk
->max_recvmsg_len
) {
2761 skb
= netlink_alloc_skb(sk
,
2762 nlk
->max_recvmsg_len
,
2767 /* available room should be exact amount to avoid MSG_TRUNC */
2769 skb_reserve(skb
, skb_tailroom(skb
) -
2770 nlk
->max_recvmsg_len
);
2773 skb
= netlink_alloc_skb(sk
, alloc_size
, nlk
->portid
,
2777 netlink_skb_set_owner_r(skb
, sk
);
2779 len
= cb
->dump(skb
, cb
);
2782 mutex_unlock(nlk
->cb_mutex
);
2784 if (sk_filter(sk
, skb
))
2787 __netlink_sendskb(sk
, skb
);
2791 nlh
= nlmsg_put_answer(skb
, cb
, NLMSG_DONE
, sizeof(len
), NLM_F_MULTI
);
2795 nl_dump_check_consistent(cb
, nlh
);
2797 memcpy(nlmsg_data(nlh
), &len
, sizeof(len
));
2799 if (sk_filter(sk
, skb
))
2802 __netlink_sendskb(sk
, skb
);
2807 nlk
->cb_running
= false;
2808 mutex_unlock(nlk
->cb_mutex
);
2809 module_put(cb
->module
);
2810 consume_skb(cb
->skb
);
2814 mutex_unlock(nlk
->cb_mutex
);
2819 int __netlink_dump_start(struct sock
*ssk
, struct sk_buff
*skb
,
2820 const struct nlmsghdr
*nlh
,
2821 struct netlink_dump_control
*control
)
2823 struct netlink_callback
*cb
;
2825 struct netlink_sock
*nlk
;
2828 /* Memory mapped dump requests need to be copied to avoid looping
2829 * on the pending state in netlink_mmap_sendmsg() while the CB hold
2830 * a reference to the skb.
2832 if (netlink_skb_is_mmaped(skb
)) {
2833 skb
= skb_copy(skb
, GFP_KERNEL
);
2837 atomic_inc(&skb
->users
);
2839 sk
= netlink_lookup(sock_net(ssk
), ssk
->sk_protocol
, NETLINK_CB(skb
).portid
);
2841 ret
= -ECONNREFUSED
;
2846 mutex_lock(nlk
->cb_mutex
);
2847 /* A dump is in progress... */
2848 if (nlk
->cb_running
) {
2852 /* add reference of module which cb->dump belongs to */
2853 if (!try_module_get(control
->module
)) {
2854 ret
= -EPROTONOSUPPORT
;
2859 memset(cb
, 0, sizeof(*cb
));
2860 cb
->dump
= control
->dump
;
2861 cb
->done
= control
->done
;
2863 cb
->data
= control
->data
;
2864 cb
->module
= control
->module
;
2865 cb
->min_dump_alloc
= control
->min_dump_alloc
;
2868 nlk
->cb_running
= true;
2870 mutex_unlock(nlk
->cb_mutex
);
2872 ret
= netlink_dump(sk
);
2878 /* We successfully started a dump, by returning -EINTR we
2879 * signal not to send ACK even if it was requested.
2885 mutex_unlock(nlk
->cb_mutex
);
2890 EXPORT_SYMBOL(__netlink_dump_start
);
2892 void netlink_ack(struct sk_buff
*in_skb
, struct nlmsghdr
*nlh
, int err
)
2894 struct sk_buff
*skb
;
2895 struct nlmsghdr
*rep
;
2896 struct nlmsgerr
*errmsg
;
2897 size_t payload
= sizeof(*errmsg
);
2898 struct netlink_sock
*nlk
= nlk_sk(NETLINK_CB(in_skb
).sk
);
2900 /* Error messages get the original request appened, unless the user
2901 * requests to cap the error message.
2903 if (!(nlk
->flags
& NETLINK_F_CAP_ACK
) && err
)
2904 payload
+= nlmsg_len(nlh
);
2906 skb
= netlink_alloc_skb(in_skb
->sk
, nlmsg_total_size(payload
),
2907 NETLINK_CB(in_skb
).portid
, GFP_KERNEL
);
2911 sk
= netlink_lookup(sock_net(in_skb
->sk
),
2912 in_skb
->sk
->sk_protocol
,
2913 NETLINK_CB(in_skb
).portid
);
2915 sk
->sk_err
= ENOBUFS
;
2916 sk
->sk_error_report(sk
);
2922 rep
= __nlmsg_put(skb
, NETLINK_CB(in_skb
).portid
, nlh
->nlmsg_seq
,
2923 NLMSG_ERROR
, payload
, 0);
2924 errmsg
= nlmsg_data(rep
);
2925 errmsg
->error
= err
;
2926 memcpy(&errmsg
->msg
, nlh
, payload
> sizeof(*errmsg
) ? nlh
->nlmsg_len
: sizeof(*nlh
));
2927 netlink_unicast(in_skb
->sk
, skb
, NETLINK_CB(in_skb
).portid
, MSG_DONTWAIT
);
2929 EXPORT_SYMBOL(netlink_ack
);
2931 int netlink_rcv_skb(struct sk_buff
*skb
, int (*cb
)(struct sk_buff
*,
2934 struct nlmsghdr
*nlh
;
2937 while (skb
->len
>= nlmsg_total_size(0)) {
2940 nlh
= nlmsg_hdr(skb
);
2943 if (nlh
->nlmsg_len
< NLMSG_HDRLEN
|| skb
->len
< nlh
->nlmsg_len
)
2946 /* Only requests are handled by the kernel */
2947 if (!(nlh
->nlmsg_flags
& NLM_F_REQUEST
))
2950 /* Skip control messages */
2951 if (nlh
->nlmsg_type
< NLMSG_MIN_TYPE
)
2959 if (nlh
->nlmsg_flags
& NLM_F_ACK
|| err
)
2960 netlink_ack(skb
, nlh
, err
);
2963 msglen
= NLMSG_ALIGN(nlh
->nlmsg_len
);
2964 if (msglen
> skb
->len
)
2966 skb_pull(skb
, msglen
);
2971 EXPORT_SYMBOL(netlink_rcv_skb
);
2974 * nlmsg_notify - send a notification netlink message
2975 * @sk: netlink socket to use
2976 * @skb: notification message
2977 * @portid: destination netlink portid for reports or 0
2978 * @group: destination multicast group or 0
2979 * @report: 1 to report back, 0 to disable
2980 * @flags: allocation flags
2982 int nlmsg_notify(struct sock
*sk
, struct sk_buff
*skb
, u32 portid
,
2983 unsigned int group
, int report
, gfp_t flags
)
2988 int exclude_portid
= 0;
2991 atomic_inc(&skb
->users
);
2992 exclude_portid
= portid
;
2995 /* errors reported via destination sk->sk_err, but propagate
2996 * delivery errors if NETLINK_BROADCAST_ERROR flag is set */
2997 err
= nlmsg_multicast(sk
, skb
, exclude_portid
, group
, flags
);
3003 err2
= nlmsg_unicast(sk
, skb
, portid
);
3004 if (!err
|| err
== -ESRCH
)
3010 EXPORT_SYMBOL(nlmsg_notify
);
3012 #ifdef CONFIG_PROC_FS
3013 struct nl_seq_iter
{
3014 struct seq_net_private p
;
3015 struct rhashtable_iter hti
;
3019 static int netlink_walk_start(struct nl_seq_iter
*iter
)
3023 err
= rhashtable_walk_init(&nl_table
[iter
->link
].hash
, &iter
->hti
);
3025 iter
->link
= MAX_LINKS
;
3029 err
= rhashtable_walk_start(&iter
->hti
);
3030 return err
== -EAGAIN
? 0 : err
;
3033 static void netlink_walk_stop(struct nl_seq_iter
*iter
)
3035 rhashtable_walk_stop(&iter
->hti
);
3036 rhashtable_walk_exit(&iter
->hti
);
3039 static void *__netlink_seq_next(struct seq_file
*seq
)
3041 struct nl_seq_iter
*iter
= seq
->private;
3042 struct netlink_sock
*nlk
;
3048 nlk
= rhashtable_walk_next(&iter
->hti
);
3051 if (PTR_ERR(nlk
) == -EAGAIN
)
3060 netlink_walk_stop(iter
);
3061 if (++iter
->link
>= MAX_LINKS
)
3064 err
= netlink_walk_start(iter
);
3066 return ERR_PTR(err
);
3068 } while (sock_net(&nlk
->sk
) != seq_file_net(seq
));
3073 static void *netlink_seq_start(struct seq_file
*seq
, loff_t
*posp
)
3075 struct nl_seq_iter
*iter
= seq
->private;
3076 void *obj
= SEQ_START_TOKEN
;
3082 err
= netlink_walk_start(iter
);
3084 return ERR_PTR(err
);
3086 for (pos
= *posp
; pos
&& obj
&& !IS_ERR(obj
); pos
--)
3087 obj
= __netlink_seq_next(seq
);
3092 static void *netlink_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
3095 return __netlink_seq_next(seq
);
3098 static void netlink_seq_stop(struct seq_file
*seq
, void *v
)
3100 struct nl_seq_iter
*iter
= seq
->private;
3102 if (iter
->link
>= MAX_LINKS
)
3105 netlink_walk_stop(iter
);
3109 static int netlink_seq_show(struct seq_file
*seq
, void *v
)
3111 if (v
== SEQ_START_TOKEN
) {
3113 "sk Eth Pid Groups "
3114 "Rmem Wmem Dump Locks Drops Inode\n");
3117 struct netlink_sock
*nlk
= nlk_sk(s
);
3119 seq_printf(seq
, "%pK %-3d %-6u %08x %-8d %-8d %d %-8d %-8d %-8lu\n",
3123 nlk
->groups
? (u32
)nlk
->groups
[0] : 0,
3124 sk_rmem_alloc_get(s
),
3125 sk_wmem_alloc_get(s
),
3127 atomic_read(&s
->sk_refcnt
),
3128 atomic_read(&s
->sk_drops
),
3136 static const struct seq_operations netlink_seq_ops
= {
3137 .start
= netlink_seq_start
,
3138 .next
= netlink_seq_next
,
3139 .stop
= netlink_seq_stop
,
3140 .show
= netlink_seq_show
,
3144 static int netlink_seq_open(struct inode
*inode
, struct file
*file
)
3146 return seq_open_net(inode
, file
, &netlink_seq_ops
,
3147 sizeof(struct nl_seq_iter
));
3150 static const struct file_operations netlink_seq_fops
= {
3151 .owner
= THIS_MODULE
,
3152 .open
= netlink_seq_open
,
3154 .llseek
= seq_lseek
,
3155 .release
= seq_release_net
,
3160 int netlink_register_notifier(struct notifier_block
*nb
)
3162 return atomic_notifier_chain_register(&netlink_chain
, nb
);
3164 EXPORT_SYMBOL(netlink_register_notifier
);
3166 int netlink_unregister_notifier(struct notifier_block
*nb
)
3168 return atomic_notifier_chain_unregister(&netlink_chain
, nb
);
3170 EXPORT_SYMBOL(netlink_unregister_notifier
);
3172 static const struct proto_ops netlink_ops
= {
3173 .family
= PF_NETLINK
,
3174 .owner
= THIS_MODULE
,
3175 .release
= netlink_release
,
3176 .bind
= netlink_bind
,
3177 .connect
= netlink_connect
,
3178 .socketpair
= sock_no_socketpair
,
3179 .accept
= sock_no_accept
,
3180 .getname
= netlink_getname
,
3181 .poll
= netlink_poll
,
3182 .ioctl
= sock_no_ioctl
,
3183 .listen
= sock_no_listen
,
3184 .shutdown
= sock_no_shutdown
,
3185 .setsockopt
= netlink_setsockopt
,
3186 .getsockopt
= netlink_getsockopt
,
3187 .sendmsg
= netlink_sendmsg
,
3188 .recvmsg
= netlink_recvmsg
,
3189 .mmap
= netlink_mmap
,
3190 .sendpage
= sock_no_sendpage
,
3193 static const struct net_proto_family netlink_family_ops
= {
3194 .family
= PF_NETLINK
,
3195 .create
= netlink_create
,
3196 .owner
= THIS_MODULE
, /* for consistency 8) */
3199 static int __net_init
netlink_net_init(struct net
*net
)
3201 #ifdef CONFIG_PROC_FS
3202 if (!proc_create("netlink", 0, net
->proc_net
, &netlink_seq_fops
))
3208 static void __net_exit
netlink_net_exit(struct net
*net
)
3210 #ifdef CONFIG_PROC_FS
3211 remove_proc_entry("netlink", net
->proc_net
);
3215 static void __init
netlink_add_usersock_entry(void)
3217 struct listeners
*listeners
;
3220 listeners
= kzalloc(sizeof(*listeners
) + NLGRPSZ(groups
), GFP_KERNEL
);
3222 panic("netlink_add_usersock_entry: Cannot allocate listeners\n");
3224 netlink_table_grab();
3226 nl_table
[NETLINK_USERSOCK
].groups
= groups
;
3227 rcu_assign_pointer(nl_table
[NETLINK_USERSOCK
].listeners
, listeners
);
3228 nl_table
[NETLINK_USERSOCK
].module
= THIS_MODULE
;
3229 nl_table
[NETLINK_USERSOCK
].registered
= 1;
3230 nl_table
[NETLINK_USERSOCK
].flags
= NL_CFG_F_NONROOT_SEND
;
3232 netlink_table_ungrab();
3235 static struct pernet_operations __net_initdata netlink_net_ops
= {
3236 .init
= netlink_net_init
,
3237 .exit
= netlink_net_exit
,
3240 static inline u32
netlink_hash(const void *data
, u32 len
, u32 seed
)
3242 const struct netlink_sock
*nlk
= data
;
3243 struct netlink_compare_arg arg
;
3245 netlink_compare_arg_init(&arg
, sock_net(&nlk
->sk
), nlk
->portid
);
3246 return jhash2((u32
*)&arg
, netlink_compare_arg_len
/ sizeof(u32
), seed
);
3249 static const struct rhashtable_params netlink_rhashtable_params
= {
3250 .head_offset
= offsetof(struct netlink_sock
, node
),
3251 .key_len
= netlink_compare_arg_len
,
3252 .obj_hashfn
= netlink_hash
,
3253 .obj_cmpfn
= netlink_compare
,
3254 .automatic_shrinking
= true,
3257 static int __init
netlink_proto_init(void)
3260 int err
= proto_register(&netlink_proto
, 0);
3265 BUILD_BUG_ON(sizeof(struct netlink_skb_parms
) > FIELD_SIZEOF(struct sk_buff
, cb
));
3267 nl_table
= kcalloc(MAX_LINKS
, sizeof(*nl_table
), GFP_KERNEL
);
3271 for (i
= 0; i
< MAX_LINKS
; i
++) {
3272 if (rhashtable_init(&nl_table
[i
].hash
,
3273 &netlink_rhashtable_params
) < 0) {
3275 rhashtable_destroy(&nl_table
[i
].hash
);
3281 INIT_LIST_HEAD(&netlink_tap_all
);
3283 netlink_add_usersock_entry();
3285 sock_register(&netlink_family_ops
);
3286 register_pernet_subsys(&netlink_net_ops
);
3287 /* The netlink device handler may be needed early. */
3292 panic("netlink_init: Cannot allocate nl_table\n");
3295 core_initcall(netlink_proto_init
);