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
88 static inline int netlink_is_kernel(struct sock
*sk
)
90 return nlk_sk(sk
)->flags
& NETLINK_F_KERNEL_SOCKET
;
93 struct netlink_table
*nl_table __read_mostly
;
94 EXPORT_SYMBOL_GPL(nl_table
);
96 static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait
);
98 static int netlink_dump(struct sock
*sk
);
99 static void netlink_skb_destructor(struct sk_buff
*skb
);
101 /* nl_table locking explained:
102 * Lookup and traversal are protected with an RCU read-side lock. Insertion
103 * and removal are protected with per bucket lock while using RCU list
104 * modification primitives and may run in parallel to RCU protected lookups.
105 * Destruction of the Netlink socket may only occur *after* nl_table_lock has
106 * been acquired * either during or after the socket has been removed from
107 * the list and after an RCU grace period.
109 DEFINE_RWLOCK(nl_table_lock
);
110 EXPORT_SYMBOL_GPL(nl_table_lock
);
111 static atomic_t nl_table_users
= ATOMIC_INIT(0);
113 #define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock));
115 static ATOMIC_NOTIFIER_HEAD(netlink_chain
);
117 static DEFINE_SPINLOCK(netlink_tap_lock
);
118 static struct list_head netlink_tap_all __read_mostly
;
120 static const struct rhashtable_params netlink_rhashtable_params
;
122 static inline u32
netlink_group_mask(u32 group
)
124 return group
? 1 << (group
- 1) : 0;
127 int netlink_add_tap(struct netlink_tap
*nt
)
129 if (unlikely(nt
->dev
->type
!= ARPHRD_NETLINK
))
132 spin_lock(&netlink_tap_lock
);
133 list_add_rcu(&nt
->list
, &netlink_tap_all
);
134 spin_unlock(&netlink_tap_lock
);
136 __module_get(nt
->module
);
140 EXPORT_SYMBOL_GPL(netlink_add_tap
);
142 static int __netlink_remove_tap(struct netlink_tap
*nt
)
145 struct netlink_tap
*tmp
;
147 spin_lock(&netlink_tap_lock
);
149 list_for_each_entry(tmp
, &netlink_tap_all
, list
) {
151 list_del_rcu(&nt
->list
);
157 pr_warn("__netlink_remove_tap: %p not found\n", nt
);
159 spin_unlock(&netlink_tap_lock
);
162 module_put(nt
->module
);
164 return found
? 0 : -ENODEV
;
167 int netlink_remove_tap(struct netlink_tap
*nt
)
171 ret
= __netlink_remove_tap(nt
);
176 EXPORT_SYMBOL_GPL(netlink_remove_tap
);
178 static bool netlink_filter_tap(const struct sk_buff
*skb
)
180 struct sock
*sk
= skb
->sk
;
182 /* We take the more conservative approach and
183 * whitelist socket protocols that may pass.
185 switch (sk
->sk_protocol
) {
187 case NETLINK_USERSOCK
:
188 case NETLINK_SOCK_DIAG
:
191 case NETLINK_FIB_LOOKUP
:
192 case NETLINK_NETFILTER
:
193 case NETLINK_GENERIC
:
200 static int __netlink_deliver_tap_skb(struct sk_buff
*skb
,
201 struct net_device
*dev
)
203 struct sk_buff
*nskb
;
204 struct sock
*sk
= skb
->sk
;
208 nskb
= skb_clone(skb
, GFP_ATOMIC
);
211 nskb
->protocol
= htons((u16
) sk
->sk_protocol
);
212 nskb
->pkt_type
= netlink_is_kernel(sk
) ?
213 PACKET_KERNEL
: PACKET_USER
;
214 skb_reset_network_header(nskb
);
215 ret
= dev_queue_xmit(nskb
);
216 if (unlikely(ret
> 0))
217 ret
= net_xmit_errno(ret
);
224 static void __netlink_deliver_tap(struct sk_buff
*skb
)
227 struct netlink_tap
*tmp
;
229 if (!netlink_filter_tap(skb
))
232 list_for_each_entry_rcu(tmp
, &netlink_tap_all
, list
) {
233 ret
= __netlink_deliver_tap_skb(skb
, tmp
->dev
);
239 static void netlink_deliver_tap(struct sk_buff
*skb
)
243 if (unlikely(!list_empty(&netlink_tap_all
)))
244 __netlink_deliver_tap(skb
);
249 static void netlink_deliver_tap_kernel(struct sock
*dst
, struct sock
*src
,
252 if (!(netlink_is_kernel(dst
) && netlink_is_kernel(src
)))
253 netlink_deliver_tap(skb
);
256 static void netlink_overrun(struct sock
*sk
)
258 struct netlink_sock
*nlk
= nlk_sk(sk
);
260 if (!(nlk
->flags
& NETLINK_F_RECV_NO_ENOBUFS
)) {
261 if (!test_and_set_bit(NETLINK_S_CONGESTED
,
262 &nlk_sk(sk
)->state
)) {
263 sk
->sk_err
= ENOBUFS
;
264 sk
->sk_error_report(sk
);
267 atomic_inc(&sk
->sk_drops
);
270 static void netlink_rcv_wake(struct sock
*sk
)
272 struct netlink_sock
*nlk
= nlk_sk(sk
);
274 if (skb_queue_empty(&sk
->sk_receive_queue
))
275 clear_bit(NETLINK_S_CONGESTED
, &nlk
->state
);
276 if (!test_bit(NETLINK_S_CONGESTED
, &nlk
->state
))
277 wake_up_interruptible(&nlk
->wait
);
280 #ifdef CONFIG_NETLINK_MMAP
281 static bool netlink_skb_is_mmaped(const struct sk_buff
*skb
)
283 return NETLINK_CB(skb
).flags
& NETLINK_SKB_MMAPED
;
286 static bool netlink_rx_is_mmaped(struct sock
*sk
)
288 return nlk_sk(sk
)->rx_ring
.pg_vec
!= NULL
;
291 static bool netlink_tx_is_mmaped(struct sock
*sk
)
293 return nlk_sk(sk
)->tx_ring
.pg_vec
!= NULL
;
296 static __pure
struct page
*pgvec_to_page(const void *addr
)
298 if (is_vmalloc_addr(addr
))
299 return vmalloc_to_page(addr
);
301 return virt_to_page(addr
);
304 static void free_pg_vec(void **pg_vec
, unsigned int order
, unsigned int len
)
308 for (i
= 0; i
< len
; i
++) {
309 if (pg_vec
[i
] != NULL
) {
310 if (is_vmalloc_addr(pg_vec
[i
]))
313 free_pages((unsigned long)pg_vec
[i
], order
);
319 static void *alloc_one_pg_vec_page(unsigned long order
)
322 gfp_t gfp_flags
= GFP_KERNEL
| __GFP_COMP
| __GFP_ZERO
|
323 __GFP_NOWARN
| __GFP_NORETRY
;
325 buffer
= (void *)__get_free_pages(gfp_flags
, order
);
329 buffer
= vzalloc((1 << order
) * PAGE_SIZE
);
333 gfp_flags
&= ~__GFP_NORETRY
;
334 return (void *)__get_free_pages(gfp_flags
, order
);
337 static void **alloc_pg_vec(struct netlink_sock
*nlk
,
338 struct nl_mmap_req
*req
, unsigned int order
)
340 unsigned int block_nr
= req
->nm_block_nr
;
344 pg_vec
= kcalloc(block_nr
, sizeof(void *), GFP_KERNEL
);
348 for (i
= 0; i
< block_nr
; i
++) {
349 pg_vec
[i
] = alloc_one_pg_vec_page(order
);
350 if (pg_vec
[i
] == NULL
)
356 free_pg_vec(pg_vec
, order
, block_nr
);
362 __netlink_set_ring(struct sock
*sk
, struct nl_mmap_req
*req
, bool tx_ring
, void **pg_vec
,
365 struct netlink_sock
*nlk
= nlk_sk(sk
);
366 struct sk_buff_head
*queue
;
367 struct netlink_ring
*ring
;
369 queue
= tx_ring
? &sk
->sk_write_queue
: &sk
->sk_receive_queue
;
370 ring
= tx_ring
? &nlk
->tx_ring
: &nlk
->rx_ring
;
372 spin_lock_bh(&queue
->lock
);
374 ring
->frame_max
= req
->nm_frame_nr
- 1;
376 ring
->frame_size
= req
->nm_frame_size
;
377 ring
->pg_vec_pages
= req
->nm_block_size
/ PAGE_SIZE
;
379 swap(ring
->pg_vec_len
, req
->nm_block_nr
);
380 swap(ring
->pg_vec_order
, order
);
381 swap(ring
->pg_vec
, pg_vec
);
383 __skb_queue_purge(queue
);
384 spin_unlock_bh(&queue
->lock
);
386 WARN_ON(atomic_read(&nlk
->mapped
));
389 free_pg_vec(pg_vec
, order
, req
->nm_block_nr
);
392 static int netlink_set_ring(struct sock
*sk
, struct nl_mmap_req
*req
,
395 struct netlink_sock
*nlk
= nlk_sk(sk
);
396 struct netlink_ring
*ring
;
397 void **pg_vec
= NULL
;
398 unsigned int order
= 0;
400 ring
= tx_ring
? &nlk
->tx_ring
: &nlk
->rx_ring
;
402 if (atomic_read(&nlk
->mapped
))
404 if (atomic_read(&ring
->pending
))
407 if (req
->nm_block_nr
) {
408 if (ring
->pg_vec
!= NULL
)
411 if ((int)req
->nm_block_size
<= 0)
413 if (!PAGE_ALIGNED(req
->nm_block_size
))
415 if (req
->nm_frame_size
< NL_MMAP_HDRLEN
)
417 if (!IS_ALIGNED(req
->nm_frame_size
, NL_MMAP_MSG_ALIGNMENT
))
420 ring
->frames_per_block
= req
->nm_block_size
/
422 if (ring
->frames_per_block
== 0)
424 if (ring
->frames_per_block
* req
->nm_block_nr
!=
428 order
= get_order(req
->nm_block_size
);
429 pg_vec
= alloc_pg_vec(nlk
, req
, order
);
433 if (req
->nm_frame_nr
)
437 mutex_lock(&nlk
->pg_vec_lock
);
438 if (atomic_read(&nlk
->mapped
) == 0) {
439 __netlink_set_ring(sk
, req
, tx_ring
, pg_vec
, order
);
440 mutex_unlock(&nlk
->pg_vec_lock
);
444 mutex_unlock(&nlk
->pg_vec_lock
);
447 free_pg_vec(pg_vec
, order
, req
->nm_block_nr
);
452 static void netlink_mm_open(struct vm_area_struct
*vma
)
454 struct file
*file
= vma
->vm_file
;
455 struct socket
*sock
= file
->private_data
;
456 struct sock
*sk
= sock
->sk
;
459 atomic_inc(&nlk_sk(sk
)->mapped
);
462 static void netlink_mm_close(struct vm_area_struct
*vma
)
464 struct file
*file
= vma
->vm_file
;
465 struct socket
*sock
= file
->private_data
;
466 struct sock
*sk
= sock
->sk
;
469 atomic_dec(&nlk_sk(sk
)->mapped
);
472 static const struct vm_operations_struct netlink_mmap_ops
= {
473 .open
= netlink_mm_open
,
474 .close
= netlink_mm_close
,
477 static int netlink_mmap(struct file
*file
, struct socket
*sock
,
478 struct vm_area_struct
*vma
)
480 struct sock
*sk
= sock
->sk
;
481 struct netlink_sock
*nlk
= nlk_sk(sk
);
482 struct netlink_ring
*ring
;
483 unsigned long start
, size
, expected
;
490 mutex_lock(&nlk
->pg_vec_lock
);
493 for (ring
= &nlk
->rx_ring
; ring
<= &nlk
->tx_ring
; ring
++) {
494 if (ring
->pg_vec
== NULL
)
496 expected
+= ring
->pg_vec_len
* ring
->pg_vec_pages
* PAGE_SIZE
;
502 size
= vma
->vm_end
- vma
->vm_start
;
503 if (size
!= expected
)
506 start
= vma
->vm_start
;
507 for (ring
= &nlk
->rx_ring
; ring
<= &nlk
->tx_ring
; ring
++) {
508 if (ring
->pg_vec
== NULL
)
511 for (i
= 0; i
< ring
->pg_vec_len
; i
++) {
513 void *kaddr
= ring
->pg_vec
[i
];
516 for (pg_num
= 0; pg_num
< ring
->pg_vec_pages
; pg_num
++) {
517 page
= pgvec_to_page(kaddr
);
518 err
= vm_insert_page(vma
, start
, page
);
527 atomic_inc(&nlk
->mapped
);
528 vma
->vm_ops
= &netlink_mmap_ops
;
531 mutex_unlock(&nlk
->pg_vec_lock
);
535 static void netlink_frame_flush_dcache(const struct nl_mmap_hdr
*hdr
, unsigned int nm_len
)
537 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
538 struct page
*p_start
, *p_end
;
540 /* First page is flushed through netlink_{get,set}_status */
541 p_start
= pgvec_to_page(hdr
+ PAGE_SIZE
);
542 p_end
= pgvec_to_page((void *)hdr
+ NL_MMAP_HDRLEN
+ nm_len
- 1);
543 while (p_start
<= p_end
) {
544 flush_dcache_page(p_start
);
550 static enum nl_mmap_status
netlink_get_status(const struct nl_mmap_hdr
*hdr
)
553 flush_dcache_page(pgvec_to_page(hdr
));
554 return hdr
->nm_status
;
557 static void netlink_set_status(struct nl_mmap_hdr
*hdr
,
558 enum nl_mmap_status status
)
561 hdr
->nm_status
= status
;
562 flush_dcache_page(pgvec_to_page(hdr
));
565 static struct nl_mmap_hdr
*
566 __netlink_lookup_frame(const struct netlink_ring
*ring
, unsigned int pos
)
568 unsigned int pg_vec_pos
, frame_off
;
570 pg_vec_pos
= pos
/ ring
->frames_per_block
;
571 frame_off
= pos
% ring
->frames_per_block
;
573 return ring
->pg_vec
[pg_vec_pos
] + (frame_off
* ring
->frame_size
);
576 static struct nl_mmap_hdr
*
577 netlink_lookup_frame(const struct netlink_ring
*ring
, unsigned int pos
,
578 enum nl_mmap_status status
)
580 struct nl_mmap_hdr
*hdr
;
582 hdr
= __netlink_lookup_frame(ring
, pos
);
583 if (netlink_get_status(hdr
) != status
)
589 static struct nl_mmap_hdr
*
590 netlink_current_frame(const struct netlink_ring
*ring
,
591 enum nl_mmap_status status
)
593 return netlink_lookup_frame(ring
, ring
->head
, status
);
596 static struct nl_mmap_hdr
*
597 netlink_previous_frame(const struct netlink_ring
*ring
,
598 enum nl_mmap_status status
)
602 prev
= ring
->head
? ring
->head
- 1 : ring
->frame_max
;
603 return netlink_lookup_frame(ring
, prev
, status
);
606 static void netlink_increment_head(struct netlink_ring
*ring
)
608 ring
->head
= ring
->head
!= ring
->frame_max
? ring
->head
+ 1 : 0;
611 static void netlink_forward_ring(struct netlink_ring
*ring
)
613 unsigned int head
= ring
->head
, pos
= head
;
614 const struct nl_mmap_hdr
*hdr
;
617 hdr
= __netlink_lookup_frame(ring
, pos
);
618 if (hdr
->nm_status
== NL_MMAP_STATUS_UNUSED
)
620 if (hdr
->nm_status
!= NL_MMAP_STATUS_SKIP
)
622 netlink_increment_head(ring
);
623 } while (ring
->head
!= head
);
626 static bool netlink_dump_space(struct netlink_sock
*nlk
)
628 struct netlink_ring
*ring
= &nlk
->rx_ring
;
629 struct nl_mmap_hdr
*hdr
;
632 hdr
= netlink_current_frame(ring
, NL_MMAP_STATUS_UNUSED
);
636 n
= ring
->head
+ ring
->frame_max
/ 2;
637 if (n
> ring
->frame_max
)
638 n
-= ring
->frame_max
;
640 hdr
= __netlink_lookup_frame(ring
, n
);
642 return hdr
->nm_status
== NL_MMAP_STATUS_UNUSED
;
645 static unsigned int netlink_poll(struct file
*file
, struct socket
*sock
,
648 struct sock
*sk
= sock
->sk
;
649 struct netlink_sock
*nlk
= nlk_sk(sk
);
653 if (nlk
->rx_ring
.pg_vec
!= NULL
) {
654 /* Memory mapped sockets don't call recvmsg(), so flow control
655 * for dumps is performed here. A dump is allowed to continue
656 * if at least half the ring is unused.
658 while (nlk
->cb_running
&& netlink_dump_space(nlk
)) {
659 err
= netlink_dump(sk
);
662 sk
->sk_error_report(sk
);
666 netlink_rcv_wake(sk
);
669 mask
= datagram_poll(file
, sock
, wait
);
671 spin_lock_bh(&sk
->sk_receive_queue
.lock
);
672 if (nlk
->rx_ring
.pg_vec
) {
673 netlink_forward_ring(&nlk
->rx_ring
);
674 if (!netlink_previous_frame(&nlk
->rx_ring
, NL_MMAP_STATUS_UNUSED
))
675 mask
|= POLLIN
| POLLRDNORM
;
677 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
679 spin_lock_bh(&sk
->sk_write_queue
.lock
);
680 if (nlk
->tx_ring
.pg_vec
) {
681 if (netlink_current_frame(&nlk
->tx_ring
, NL_MMAP_STATUS_UNUSED
))
682 mask
|= POLLOUT
| POLLWRNORM
;
684 spin_unlock_bh(&sk
->sk_write_queue
.lock
);
689 static struct nl_mmap_hdr
*netlink_mmap_hdr(struct sk_buff
*skb
)
691 return (struct nl_mmap_hdr
*)(skb
->head
- NL_MMAP_HDRLEN
);
694 static void netlink_ring_setup_skb(struct sk_buff
*skb
, struct sock
*sk
,
695 struct netlink_ring
*ring
,
696 struct nl_mmap_hdr
*hdr
)
701 size
= ring
->frame_size
- NL_MMAP_HDRLEN
;
702 data
= (void *)hdr
+ NL_MMAP_HDRLEN
;
706 skb_reset_tail_pointer(skb
);
707 skb
->end
= skb
->tail
+ size
;
710 skb
->destructor
= netlink_skb_destructor
;
711 NETLINK_CB(skb
).flags
|= NETLINK_SKB_MMAPED
;
712 NETLINK_CB(skb
).sk
= sk
;
715 static int netlink_mmap_sendmsg(struct sock
*sk
, struct msghdr
*msg
,
716 u32 dst_portid
, u32 dst_group
,
717 struct scm_cookie
*scm
)
719 struct netlink_sock
*nlk
= nlk_sk(sk
);
720 struct netlink_ring
*ring
;
721 struct nl_mmap_hdr
*hdr
;
724 int err
= 0, len
= 0;
726 mutex_lock(&nlk
->pg_vec_lock
);
728 ring
= &nlk
->tx_ring
;
729 maxlen
= ring
->frame_size
- NL_MMAP_HDRLEN
;
734 hdr
= netlink_current_frame(ring
, NL_MMAP_STATUS_VALID
);
736 if (!(msg
->msg_flags
& MSG_DONTWAIT
) &&
737 atomic_read(&nlk
->tx_ring
.pending
))
742 nm_len
= ACCESS_ONCE(hdr
->nm_len
);
743 if (nm_len
> maxlen
) {
748 netlink_frame_flush_dcache(hdr
, nm_len
);
750 skb
= alloc_skb(nm_len
, GFP_KERNEL
);
755 __skb_put(skb
, nm_len
);
756 memcpy(skb
->data
, (void *)hdr
+ NL_MMAP_HDRLEN
, nm_len
);
757 netlink_set_status(hdr
, NL_MMAP_STATUS_UNUSED
);
759 netlink_increment_head(ring
);
761 NETLINK_CB(skb
).portid
= nlk
->portid
;
762 NETLINK_CB(skb
).dst_group
= dst_group
;
763 NETLINK_CB(skb
).creds
= scm
->creds
;
765 err
= security_netlink_send(sk
, skb
);
771 if (unlikely(dst_group
)) {
772 atomic_inc(&skb
->users
);
773 netlink_broadcast(sk
, skb
, dst_portid
, dst_group
,
776 err
= netlink_unicast(sk
, skb
, dst_portid
,
777 msg
->msg_flags
& MSG_DONTWAIT
);
782 } while (hdr
!= NULL
||
783 (!(msg
->msg_flags
& MSG_DONTWAIT
) &&
784 atomic_read(&nlk
->tx_ring
.pending
)));
789 mutex_unlock(&nlk
->pg_vec_lock
);
793 static void netlink_queue_mmaped_skb(struct sock
*sk
, struct sk_buff
*skb
)
795 struct nl_mmap_hdr
*hdr
;
797 hdr
= netlink_mmap_hdr(skb
);
798 hdr
->nm_len
= skb
->len
;
799 hdr
->nm_group
= NETLINK_CB(skb
).dst_group
;
800 hdr
->nm_pid
= NETLINK_CB(skb
).creds
.pid
;
801 hdr
->nm_uid
= from_kuid(sk_user_ns(sk
), NETLINK_CB(skb
).creds
.uid
);
802 hdr
->nm_gid
= from_kgid(sk_user_ns(sk
), NETLINK_CB(skb
).creds
.gid
);
803 netlink_frame_flush_dcache(hdr
, hdr
->nm_len
);
804 netlink_set_status(hdr
, NL_MMAP_STATUS_VALID
);
806 NETLINK_CB(skb
).flags
|= NETLINK_SKB_DELIVERED
;
810 static void netlink_ring_set_copied(struct sock
*sk
, struct sk_buff
*skb
)
812 struct netlink_sock
*nlk
= nlk_sk(sk
);
813 struct netlink_ring
*ring
= &nlk
->rx_ring
;
814 struct nl_mmap_hdr
*hdr
;
816 spin_lock_bh(&sk
->sk_receive_queue
.lock
);
817 hdr
= netlink_current_frame(ring
, NL_MMAP_STATUS_UNUSED
);
819 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
824 netlink_increment_head(ring
);
825 __skb_queue_tail(&sk
->sk_receive_queue
, skb
);
826 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
828 hdr
->nm_len
= skb
->len
;
829 hdr
->nm_group
= NETLINK_CB(skb
).dst_group
;
830 hdr
->nm_pid
= NETLINK_CB(skb
).creds
.pid
;
831 hdr
->nm_uid
= from_kuid(sk_user_ns(sk
), NETLINK_CB(skb
).creds
.uid
);
832 hdr
->nm_gid
= from_kgid(sk_user_ns(sk
), NETLINK_CB(skb
).creds
.gid
);
833 netlink_set_status(hdr
, NL_MMAP_STATUS_COPY
);
836 #else /* CONFIG_NETLINK_MMAP */
837 #define netlink_skb_is_mmaped(skb) false
838 #define netlink_rx_is_mmaped(sk) false
839 #define netlink_tx_is_mmaped(sk) false
840 #define netlink_mmap sock_no_mmap
841 #define netlink_poll datagram_poll
842 #define netlink_mmap_sendmsg(sk, msg, dst_portid, dst_group, scm) 0
843 #endif /* CONFIG_NETLINK_MMAP */
845 static void netlink_skb_destructor(struct sk_buff
*skb
)
847 #ifdef CONFIG_NETLINK_MMAP
848 struct nl_mmap_hdr
*hdr
;
849 struct netlink_ring
*ring
;
852 /* If a packet from the kernel to userspace was freed because of an
853 * error without being delivered to userspace, the kernel must reset
854 * the status. In the direction userspace to kernel, the status is
855 * always reset here after the packet was processed and freed.
857 if (netlink_skb_is_mmaped(skb
)) {
858 hdr
= netlink_mmap_hdr(skb
);
859 sk
= NETLINK_CB(skb
).sk
;
861 if (NETLINK_CB(skb
).flags
& NETLINK_SKB_TX
) {
862 netlink_set_status(hdr
, NL_MMAP_STATUS_UNUSED
);
863 ring
= &nlk_sk(sk
)->tx_ring
;
865 if (!(NETLINK_CB(skb
).flags
& NETLINK_SKB_DELIVERED
)) {
867 netlink_set_status(hdr
, NL_MMAP_STATUS_VALID
);
869 ring
= &nlk_sk(sk
)->rx_ring
;
872 WARN_ON(atomic_read(&ring
->pending
) == 0);
873 atomic_dec(&ring
->pending
);
879 if (is_vmalloc_addr(skb
->head
)) {
881 !atomic_dec_return(&(skb_shinfo(skb
)->dataref
)))
890 static void netlink_skb_set_owner_r(struct sk_buff
*skb
, struct sock
*sk
)
892 WARN_ON(skb
->sk
!= NULL
);
894 skb
->destructor
= netlink_skb_destructor
;
895 atomic_add(skb
->truesize
, &sk
->sk_rmem_alloc
);
896 sk_mem_charge(sk
, skb
->truesize
);
899 static void netlink_sock_destruct(struct sock
*sk
)
901 struct netlink_sock
*nlk
= nlk_sk(sk
);
903 if (nlk
->cb_running
) {
905 nlk
->cb
.done(&nlk
->cb
);
907 module_put(nlk
->cb
.module
);
908 kfree_skb(nlk
->cb
.skb
);
911 skb_queue_purge(&sk
->sk_receive_queue
);
912 #ifdef CONFIG_NETLINK_MMAP
914 struct nl_mmap_req req
;
916 memset(&req
, 0, sizeof(req
));
917 if (nlk
->rx_ring
.pg_vec
)
918 __netlink_set_ring(sk
, &req
, false, NULL
, 0);
919 memset(&req
, 0, sizeof(req
));
920 if (nlk
->tx_ring
.pg_vec
)
921 __netlink_set_ring(sk
, &req
, true, NULL
, 0);
923 #endif /* CONFIG_NETLINK_MMAP */
925 if (!sock_flag(sk
, SOCK_DEAD
)) {
926 printk(KERN_ERR
"Freeing alive netlink socket %p\n", sk
);
930 WARN_ON(atomic_read(&sk
->sk_rmem_alloc
));
931 WARN_ON(atomic_read(&sk
->sk_wmem_alloc
));
932 WARN_ON(nlk_sk(sk
)->groups
);
935 /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on
936 * SMP. Look, when several writers sleep and reader wakes them up, all but one
937 * immediately hit write lock and grab all the cpus. Exclusive sleep solves
938 * this, _but_ remember, it adds useless work on UP machines.
941 void netlink_table_grab(void)
942 __acquires(nl_table_lock
)
946 write_lock_irq(&nl_table_lock
);
948 if (atomic_read(&nl_table_users
)) {
949 DECLARE_WAITQUEUE(wait
, current
);
951 add_wait_queue_exclusive(&nl_table_wait
, &wait
);
953 set_current_state(TASK_UNINTERRUPTIBLE
);
954 if (atomic_read(&nl_table_users
) == 0)
956 write_unlock_irq(&nl_table_lock
);
958 write_lock_irq(&nl_table_lock
);
961 __set_current_state(TASK_RUNNING
);
962 remove_wait_queue(&nl_table_wait
, &wait
);
966 void netlink_table_ungrab(void)
967 __releases(nl_table_lock
)
969 write_unlock_irq(&nl_table_lock
);
970 wake_up(&nl_table_wait
);
974 netlink_lock_table(void)
976 /* read_lock() synchronizes us to netlink_table_grab */
978 read_lock(&nl_table_lock
);
979 atomic_inc(&nl_table_users
);
980 read_unlock(&nl_table_lock
);
984 netlink_unlock_table(void)
986 if (atomic_dec_and_test(&nl_table_users
))
987 wake_up(&nl_table_wait
);
990 struct netlink_compare_arg
996 /* Doing sizeof directly may yield 4 extra bytes on 64-bit. */
997 #define netlink_compare_arg_len \
998 (offsetof(struct netlink_compare_arg, portid) + sizeof(u32))
1000 static inline int netlink_compare(struct rhashtable_compare_arg
*arg
,
1003 const struct netlink_compare_arg
*x
= arg
->key
;
1004 const struct netlink_sock
*nlk
= ptr
;
1006 return nlk
->portid
!= x
->portid
||
1007 !net_eq(sock_net(&nlk
->sk
), read_pnet(&x
->pnet
));
1010 static void netlink_compare_arg_init(struct netlink_compare_arg
*arg
,
1011 struct net
*net
, u32 portid
)
1013 memset(arg
, 0, sizeof(*arg
));
1014 write_pnet(&arg
->pnet
, net
);
1015 arg
->portid
= portid
;
1018 static struct sock
*__netlink_lookup(struct netlink_table
*table
, u32 portid
,
1021 struct netlink_compare_arg arg
;
1023 netlink_compare_arg_init(&arg
, net
, portid
);
1024 return rhashtable_lookup_fast(&table
->hash
, &arg
,
1025 netlink_rhashtable_params
);
1028 static int __netlink_insert(struct netlink_table
*table
, struct sock
*sk
)
1030 struct netlink_compare_arg arg
;
1032 netlink_compare_arg_init(&arg
, sock_net(sk
), nlk_sk(sk
)->portid
);
1033 return rhashtable_lookup_insert_key(&table
->hash
, &arg
,
1035 netlink_rhashtable_params
);
1038 static struct sock
*netlink_lookup(struct net
*net
, int protocol
, u32 portid
)
1040 struct netlink_table
*table
= &nl_table
[protocol
];
1044 sk
= __netlink_lookup(table
, portid
, net
);
1052 static const struct proto_ops netlink_ops
;
1055 netlink_update_listeners(struct sock
*sk
)
1057 struct netlink_table
*tbl
= &nl_table
[sk
->sk_protocol
];
1060 struct listeners
*listeners
;
1062 listeners
= nl_deref_protected(tbl
->listeners
);
1066 for (i
= 0; i
< NLGRPLONGS(tbl
->groups
); i
++) {
1068 sk_for_each_bound(sk
, &tbl
->mc_list
) {
1069 if (i
< NLGRPLONGS(nlk_sk(sk
)->ngroups
))
1070 mask
|= nlk_sk(sk
)->groups
[i
];
1072 listeners
->masks
[i
] = mask
;
1074 /* this function is only called with the netlink table "grabbed", which
1075 * makes sure updates are visible before bind or setsockopt return. */
1078 static int netlink_insert(struct sock
*sk
, u32 portid
)
1080 struct netlink_table
*table
= &nl_table
[sk
->sk_protocol
];
1086 if (nlk_sk(sk
)->portid
)
1090 if (BITS_PER_LONG
> 32 &&
1091 unlikely(atomic_read(&table
->hash
.nelems
) >= UINT_MAX
))
1094 nlk_sk(sk
)->portid
= portid
;
1097 err
= __netlink_insert(table
, sk
);
1101 nlk_sk(sk
)->portid
= 0;
1110 static void netlink_remove(struct sock
*sk
)
1112 struct netlink_table
*table
;
1114 table
= &nl_table
[sk
->sk_protocol
];
1115 if (!rhashtable_remove_fast(&table
->hash
, &nlk_sk(sk
)->node
,
1116 netlink_rhashtable_params
)) {
1117 WARN_ON(atomic_read(&sk
->sk_refcnt
) == 1);
1121 netlink_table_grab();
1122 if (nlk_sk(sk
)->subscriptions
) {
1123 __sk_del_bind_node(sk
);
1124 netlink_update_listeners(sk
);
1126 if (sk
->sk_protocol
== NETLINK_GENERIC
)
1127 atomic_inc(&genl_sk_destructing_cnt
);
1128 netlink_table_ungrab();
1131 static struct proto netlink_proto
= {
1133 .owner
= THIS_MODULE
,
1134 .obj_size
= sizeof(struct netlink_sock
),
1137 static int __netlink_create(struct net
*net
, struct socket
*sock
,
1138 struct mutex
*cb_mutex
, int protocol
,
1142 struct netlink_sock
*nlk
;
1144 sock
->ops
= &netlink_ops
;
1146 sk
= sk_alloc(net
, PF_NETLINK
, GFP_KERNEL
, &netlink_proto
, kern
);
1150 sock_init_data(sock
, sk
);
1154 nlk
->cb_mutex
= cb_mutex
;
1156 nlk
->cb_mutex
= &nlk
->cb_def_mutex
;
1157 mutex_init(nlk
->cb_mutex
);
1159 init_waitqueue_head(&nlk
->wait
);
1160 #ifdef CONFIG_NETLINK_MMAP
1161 mutex_init(&nlk
->pg_vec_lock
);
1164 sk
->sk_destruct
= netlink_sock_destruct
;
1165 sk
->sk_protocol
= protocol
;
1169 static int netlink_create(struct net
*net
, struct socket
*sock
, int protocol
,
1172 struct module
*module
= NULL
;
1173 struct mutex
*cb_mutex
;
1174 struct netlink_sock
*nlk
;
1175 int (*bind
)(struct net
*net
, int group
);
1176 void (*unbind
)(struct net
*net
, int group
);
1179 sock
->state
= SS_UNCONNECTED
;
1181 if (sock
->type
!= SOCK_RAW
&& sock
->type
!= SOCK_DGRAM
)
1182 return -ESOCKTNOSUPPORT
;
1184 if (protocol
< 0 || protocol
>= MAX_LINKS
)
1185 return -EPROTONOSUPPORT
;
1187 netlink_lock_table();
1188 #ifdef CONFIG_MODULES
1189 if (!nl_table
[protocol
].registered
) {
1190 netlink_unlock_table();
1191 request_module("net-pf-%d-proto-%d", PF_NETLINK
, protocol
);
1192 netlink_lock_table();
1195 if (nl_table
[protocol
].registered
&&
1196 try_module_get(nl_table
[protocol
].module
))
1197 module
= nl_table
[protocol
].module
;
1199 err
= -EPROTONOSUPPORT
;
1200 cb_mutex
= nl_table
[protocol
].cb_mutex
;
1201 bind
= nl_table
[protocol
].bind
;
1202 unbind
= nl_table
[protocol
].unbind
;
1203 netlink_unlock_table();
1208 err
= __netlink_create(net
, sock
, cb_mutex
, protocol
, kern
);
1213 sock_prot_inuse_add(net
, &netlink_proto
, 1);
1216 nlk
= nlk_sk(sock
->sk
);
1217 nlk
->module
= module
;
1218 nlk
->netlink_bind
= bind
;
1219 nlk
->netlink_unbind
= unbind
;
1228 static void deferred_put_nlk_sk(struct rcu_head
*head
)
1230 struct netlink_sock
*nlk
= container_of(head
, struct netlink_sock
, rcu
);
1235 static int netlink_release(struct socket
*sock
)
1237 struct sock
*sk
= sock
->sk
;
1238 struct netlink_sock
*nlk
;
1248 * OK. Socket is unlinked, any packets that arrive now
1252 /* must not acquire netlink_table_lock in any way again before unbind
1253 * and notifying genetlink is done as otherwise it might deadlock
1255 if (nlk
->netlink_unbind
) {
1258 for (i
= 0; i
< nlk
->ngroups
; i
++)
1259 if (test_bit(i
, nlk
->groups
))
1260 nlk
->netlink_unbind(sock_net(sk
), i
+ 1);
1262 if (sk
->sk_protocol
== NETLINK_GENERIC
&&
1263 atomic_dec_return(&genl_sk_destructing_cnt
) == 0)
1264 wake_up(&genl_sk_destructing_waitq
);
1267 wake_up_interruptible_all(&nlk
->wait
);
1269 skb_queue_purge(&sk
->sk_write_queue
);
1272 struct netlink_notify n
= {
1273 .net
= sock_net(sk
),
1274 .protocol
= sk
->sk_protocol
,
1275 .portid
= nlk
->portid
,
1277 atomic_notifier_call_chain(&netlink_chain
,
1278 NETLINK_URELEASE
, &n
);
1281 module_put(nlk
->module
);
1283 if (netlink_is_kernel(sk
)) {
1284 netlink_table_grab();
1285 BUG_ON(nl_table
[sk
->sk_protocol
].registered
== 0);
1286 if (--nl_table
[sk
->sk_protocol
].registered
== 0) {
1287 struct listeners
*old
;
1289 old
= nl_deref_protected(nl_table
[sk
->sk_protocol
].listeners
);
1290 RCU_INIT_POINTER(nl_table
[sk
->sk_protocol
].listeners
, NULL
);
1291 kfree_rcu(old
, rcu
);
1292 nl_table
[sk
->sk_protocol
].module
= NULL
;
1293 nl_table
[sk
->sk_protocol
].bind
= NULL
;
1294 nl_table
[sk
->sk_protocol
].unbind
= NULL
;
1295 nl_table
[sk
->sk_protocol
].flags
= 0;
1296 nl_table
[sk
->sk_protocol
].registered
= 0;
1298 netlink_table_ungrab();
1305 sock_prot_inuse_add(sock_net(sk
), &netlink_proto
, -1);
1307 call_rcu(&nlk
->rcu
, deferred_put_nlk_sk
);
1311 static int netlink_autobind(struct socket
*sock
)
1313 struct sock
*sk
= sock
->sk
;
1314 struct net
*net
= sock_net(sk
);
1315 struct netlink_table
*table
= &nl_table
[sk
->sk_protocol
];
1316 s32 portid
= task_tgid_vnr(current
);
1324 ok
= !__netlink_lookup(table
, portid
, net
);
1327 /* Bind collision, search negative portid values. */
1329 /* rover will be in range [S32_MIN, -4097] */
1330 rover
= S32_MIN
+ prandom_u32_max(-4096 - S32_MIN
);
1331 else if (rover
>= -4096)
1337 err
= netlink_insert(sk
, portid
);
1338 if (err
== -EADDRINUSE
)
1341 /* If 2 threads race to autobind, that is fine. */
1349 * __netlink_ns_capable - General netlink message capability test
1350 * @nsp: NETLINK_CB of the socket buffer holding a netlink command from userspace.
1351 * @user_ns: The user namespace of the capability to use
1352 * @cap: The capability to use
1354 * Test to see if the opener of the socket we received the message
1355 * from had when the netlink socket was created and the sender of the
1356 * message has has the capability @cap in the user namespace @user_ns.
1358 bool __netlink_ns_capable(const struct netlink_skb_parms
*nsp
,
1359 struct user_namespace
*user_ns
, int cap
)
1361 return ((nsp
->flags
& NETLINK_SKB_DST
) ||
1362 file_ns_capable(nsp
->sk
->sk_socket
->file
, user_ns
, cap
)) &&
1363 ns_capable(user_ns
, cap
);
1365 EXPORT_SYMBOL(__netlink_ns_capable
);
1368 * netlink_ns_capable - General netlink message capability test
1369 * @skb: socket buffer holding a netlink command from userspace
1370 * @user_ns: The user namespace of the capability to use
1371 * @cap: The capability to use
1373 * Test to see if the opener of the socket we received the message
1374 * from had when the netlink socket was created and the sender of the
1375 * message has has the capability @cap in the user namespace @user_ns.
1377 bool netlink_ns_capable(const struct sk_buff
*skb
,
1378 struct user_namespace
*user_ns
, int cap
)
1380 return __netlink_ns_capable(&NETLINK_CB(skb
), user_ns
, cap
);
1382 EXPORT_SYMBOL(netlink_ns_capable
);
1385 * netlink_capable - Netlink global message capability test
1386 * @skb: socket buffer holding a netlink command from userspace
1387 * @cap: The capability to use
1389 * Test to see if the opener of the socket we received the message
1390 * from had when the netlink socket was created and the sender of the
1391 * message has has the capability @cap in all user namespaces.
1393 bool netlink_capable(const struct sk_buff
*skb
, int cap
)
1395 return netlink_ns_capable(skb
, &init_user_ns
, cap
);
1397 EXPORT_SYMBOL(netlink_capable
);
1400 * netlink_net_capable - Netlink network namespace message capability test
1401 * @skb: socket buffer holding a netlink command from userspace
1402 * @cap: The capability to use
1404 * Test to see if the opener of the socket we received the message
1405 * from had when the netlink socket was created and the sender of the
1406 * message has has the capability @cap over the network namespace of
1407 * the socket we received the message from.
1409 bool netlink_net_capable(const struct sk_buff
*skb
, int cap
)
1411 return netlink_ns_capable(skb
, sock_net(skb
->sk
)->user_ns
, cap
);
1413 EXPORT_SYMBOL(netlink_net_capable
);
1415 static inline int netlink_allowed(const struct socket
*sock
, unsigned int flag
)
1417 return (nl_table
[sock
->sk
->sk_protocol
].flags
& flag
) ||
1418 ns_capable(sock_net(sock
->sk
)->user_ns
, CAP_NET_ADMIN
);
1422 netlink_update_subscriptions(struct sock
*sk
, unsigned int subscriptions
)
1424 struct netlink_sock
*nlk
= nlk_sk(sk
);
1426 if (nlk
->subscriptions
&& !subscriptions
)
1427 __sk_del_bind_node(sk
);
1428 else if (!nlk
->subscriptions
&& subscriptions
)
1429 sk_add_bind_node(sk
, &nl_table
[sk
->sk_protocol
].mc_list
);
1430 nlk
->subscriptions
= subscriptions
;
1433 static int netlink_realloc_groups(struct sock
*sk
)
1435 struct netlink_sock
*nlk
= nlk_sk(sk
);
1436 unsigned int groups
;
1437 unsigned long *new_groups
;
1440 netlink_table_grab();
1442 groups
= nl_table
[sk
->sk_protocol
].groups
;
1443 if (!nl_table
[sk
->sk_protocol
].registered
) {
1448 if (nlk
->ngroups
>= groups
)
1451 new_groups
= krealloc(nlk
->groups
, NLGRPSZ(groups
), GFP_ATOMIC
);
1452 if (new_groups
== NULL
) {
1456 memset((char *)new_groups
+ NLGRPSZ(nlk
->ngroups
), 0,
1457 NLGRPSZ(groups
) - NLGRPSZ(nlk
->ngroups
));
1459 nlk
->groups
= new_groups
;
1460 nlk
->ngroups
= groups
;
1462 netlink_table_ungrab();
1466 static void netlink_undo_bind(int group
, long unsigned int groups
,
1469 struct netlink_sock
*nlk
= nlk_sk(sk
);
1472 if (!nlk
->netlink_unbind
)
1475 for (undo
= 0; undo
< group
; undo
++)
1476 if (test_bit(undo
, &groups
))
1477 nlk
->netlink_unbind(sock_net(sk
), undo
+ 1);
1480 static int netlink_bind(struct socket
*sock
, struct sockaddr
*addr
,
1483 struct sock
*sk
= sock
->sk
;
1484 struct net
*net
= sock_net(sk
);
1485 struct netlink_sock
*nlk
= nlk_sk(sk
);
1486 struct sockaddr_nl
*nladdr
= (struct sockaddr_nl
*)addr
;
1488 long unsigned int groups
= nladdr
->nl_groups
;
1490 if (addr_len
< sizeof(struct sockaddr_nl
))
1493 if (nladdr
->nl_family
!= AF_NETLINK
)
1496 /* Only superuser is allowed to listen multicasts */
1498 if (!netlink_allowed(sock
, NL_CFG_F_NONROOT_RECV
))
1500 err
= netlink_realloc_groups(sk
);
1506 if (nladdr
->nl_pid
!= nlk
->portid
)
1509 if (nlk
->netlink_bind
&& groups
) {
1512 for (group
= 0; group
< nlk
->ngroups
; group
++) {
1513 if (!test_bit(group
, &groups
))
1515 err
= nlk
->netlink_bind(net
, group
+ 1);
1518 netlink_undo_bind(group
, groups
, sk
);
1524 err
= nladdr
->nl_pid
?
1525 netlink_insert(sk
, nladdr
->nl_pid
) :
1526 netlink_autobind(sock
);
1528 netlink_undo_bind(nlk
->ngroups
, groups
, sk
);
1533 if (!groups
&& (nlk
->groups
== NULL
|| !(u32
)nlk
->groups
[0]))
1536 netlink_table_grab();
1537 netlink_update_subscriptions(sk
, nlk
->subscriptions
+
1539 hweight32(nlk
->groups
[0]));
1540 nlk
->groups
[0] = (nlk
->groups
[0] & ~0xffffffffUL
) | groups
;
1541 netlink_update_listeners(sk
);
1542 netlink_table_ungrab();
1547 static int netlink_connect(struct socket
*sock
, struct sockaddr
*addr
,
1548 int alen
, int flags
)
1551 struct sock
*sk
= sock
->sk
;
1552 struct netlink_sock
*nlk
= nlk_sk(sk
);
1553 struct sockaddr_nl
*nladdr
= (struct sockaddr_nl
*)addr
;
1555 if (alen
< sizeof(addr
->sa_family
))
1558 if (addr
->sa_family
== AF_UNSPEC
) {
1559 sk
->sk_state
= NETLINK_UNCONNECTED
;
1560 nlk
->dst_portid
= 0;
1564 if (addr
->sa_family
!= AF_NETLINK
)
1567 if ((nladdr
->nl_groups
|| nladdr
->nl_pid
) &&
1568 !netlink_allowed(sock
, NL_CFG_F_NONROOT_SEND
))
1572 err
= netlink_autobind(sock
);
1575 sk
->sk_state
= NETLINK_CONNECTED
;
1576 nlk
->dst_portid
= nladdr
->nl_pid
;
1577 nlk
->dst_group
= ffs(nladdr
->nl_groups
);
1583 static int netlink_getname(struct socket
*sock
, struct sockaddr
*addr
,
1584 int *addr_len
, int peer
)
1586 struct sock
*sk
= sock
->sk
;
1587 struct netlink_sock
*nlk
= nlk_sk(sk
);
1588 DECLARE_SOCKADDR(struct sockaddr_nl
*, nladdr
, addr
);
1590 nladdr
->nl_family
= AF_NETLINK
;
1592 *addr_len
= sizeof(*nladdr
);
1595 nladdr
->nl_pid
= nlk
->dst_portid
;
1596 nladdr
->nl_groups
= netlink_group_mask(nlk
->dst_group
);
1598 nladdr
->nl_pid
= nlk
->portid
;
1599 nladdr
->nl_groups
= nlk
->groups
? nlk
->groups
[0] : 0;
1604 static struct sock
*netlink_getsockbyportid(struct sock
*ssk
, u32 portid
)
1607 struct netlink_sock
*nlk
;
1609 sock
= netlink_lookup(sock_net(ssk
), ssk
->sk_protocol
, portid
);
1611 return ERR_PTR(-ECONNREFUSED
);
1613 /* Don't bother queuing skb if kernel socket has no input function */
1615 if (sock
->sk_state
== NETLINK_CONNECTED
&&
1616 nlk
->dst_portid
!= nlk_sk(ssk
)->portid
) {
1618 return ERR_PTR(-ECONNREFUSED
);
1623 struct sock
*netlink_getsockbyfilp(struct file
*filp
)
1625 struct inode
*inode
= file_inode(filp
);
1628 if (!S_ISSOCK(inode
->i_mode
))
1629 return ERR_PTR(-ENOTSOCK
);
1631 sock
= SOCKET_I(inode
)->sk
;
1632 if (sock
->sk_family
!= AF_NETLINK
)
1633 return ERR_PTR(-EINVAL
);
1639 static struct sk_buff
*netlink_alloc_large_skb(unsigned int size
,
1642 struct sk_buff
*skb
;
1645 if (size
<= NLMSG_GOODSIZE
|| broadcast
)
1646 return alloc_skb(size
, GFP_KERNEL
);
1648 size
= SKB_DATA_ALIGN(size
) +
1649 SKB_DATA_ALIGN(sizeof(struct skb_shared_info
));
1651 data
= vmalloc(size
);
1655 skb
= __build_skb(data
, size
);
1659 skb
->destructor
= netlink_skb_destructor
;
1665 * Attach a skb to a netlink socket.
1666 * The caller must hold a reference to the destination socket. On error, the
1667 * reference is dropped. The skb is not send to the destination, just all
1668 * all error checks are performed and memory in the queue is reserved.
1670 * < 0: error. skb freed, reference to sock dropped.
1672 * 1: repeat lookup - reference dropped while waiting for socket memory.
1674 int netlink_attachskb(struct sock
*sk
, struct sk_buff
*skb
,
1675 long *timeo
, struct sock
*ssk
)
1677 struct netlink_sock
*nlk
;
1681 if ((atomic_read(&sk
->sk_rmem_alloc
) > sk
->sk_rcvbuf
||
1682 test_bit(NETLINK_S_CONGESTED
, &nlk
->state
)) &&
1683 !netlink_skb_is_mmaped(skb
)) {
1684 DECLARE_WAITQUEUE(wait
, current
);
1686 if (!ssk
|| netlink_is_kernel(ssk
))
1687 netlink_overrun(sk
);
1693 __set_current_state(TASK_INTERRUPTIBLE
);
1694 add_wait_queue(&nlk
->wait
, &wait
);
1696 if ((atomic_read(&sk
->sk_rmem_alloc
) > sk
->sk_rcvbuf
||
1697 test_bit(NETLINK_S_CONGESTED
, &nlk
->state
)) &&
1698 !sock_flag(sk
, SOCK_DEAD
))
1699 *timeo
= schedule_timeout(*timeo
);
1701 __set_current_state(TASK_RUNNING
);
1702 remove_wait_queue(&nlk
->wait
, &wait
);
1705 if (signal_pending(current
)) {
1707 return sock_intr_errno(*timeo
);
1711 netlink_skb_set_owner_r(skb
, sk
);
1715 static int __netlink_sendskb(struct sock
*sk
, struct sk_buff
*skb
)
1719 netlink_deliver_tap(skb
);
1721 #ifdef CONFIG_NETLINK_MMAP
1722 if (netlink_skb_is_mmaped(skb
))
1723 netlink_queue_mmaped_skb(sk
, skb
);
1724 else if (netlink_rx_is_mmaped(sk
))
1725 netlink_ring_set_copied(sk
, skb
);
1727 #endif /* CONFIG_NETLINK_MMAP */
1728 skb_queue_tail(&sk
->sk_receive_queue
, skb
);
1729 sk
->sk_data_ready(sk
);
1733 int netlink_sendskb(struct sock
*sk
, struct sk_buff
*skb
)
1735 int len
= __netlink_sendskb(sk
, skb
);
1741 void netlink_detachskb(struct sock
*sk
, struct sk_buff
*skb
)
1747 static struct sk_buff
*netlink_trim(struct sk_buff
*skb
, gfp_t allocation
)
1751 WARN_ON(skb
->sk
!= NULL
);
1752 if (netlink_skb_is_mmaped(skb
))
1755 delta
= skb
->end
- skb
->tail
;
1756 if (is_vmalloc_addr(skb
->head
) || delta
* 2 < skb
->truesize
)
1759 if (skb_shared(skb
)) {
1760 struct sk_buff
*nskb
= skb_clone(skb
, allocation
);
1767 if (!pskb_expand_head(skb
, 0, -delta
, allocation
))
1768 skb
->truesize
-= delta
;
1773 static int netlink_unicast_kernel(struct sock
*sk
, struct sk_buff
*skb
,
1777 struct netlink_sock
*nlk
= nlk_sk(sk
);
1779 ret
= -ECONNREFUSED
;
1780 if (nlk
->netlink_rcv
!= NULL
) {
1782 netlink_skb_set_owner_r(skb
, sk
);
1783 NETLINK_CB(skb
).sk
= ssk
;
1784 netlink_deliver_tap_kernel(sk
, ssk
, skb
);
1785 nlk
->netlink_rcv(skb
);
1794 int netlink_unicast(struct sock
*ssk
, struct sk_buff
*skb
,
1795 u32 portid
, int nonblock
)
1801 skb
= netlink_trim(skb
, gfp_any());
1803 timeo
= sock_sndtimeo(ssk
, nonblock
);
1805 sk
= netlink_getsockbyportid(ssk
, portid
);
1810 if (netlink_is_kernel(sk
))
1811 return netlink_unicast_kernel(sk
, skb
, ssk
);
1813 if (sk_filter(sk
, skb
)) {
1820 err
= netlink_attachskb(sk
, skb
, &timeo
, ssk
);
1826 return netlink_sendskb(sk
, skb
);
1828 EXPORT_SYMBOL(netlink_unicast
);
1830 struct sk_buff
*netlink_alloc_skb(struct sock
*ssk
, unsigned int size
,
1831 u32 dst_portid
, gfp_t gfp_mask
)
1833 #ifdef CONFIG_NETLINK_MMAP
1834 struct sock
*sk
= NULL
;
1835 struct sk_buff
*skb
;
1836 struct netlink_ring
*ring
;
1837 struct nl_mmap_hdr
*hdr
;
1838 unsigned int maxlen
;
1840 sk
= netlink_getsockbyportid(ssk
, dst_portid
);
1844 ring
= &nlk_sk(sk
)->rx_ring
;
1845 /* fast-path without atomic ops for common case: non-mmaped receiver */
1846 if (ring
->pg_vec
== NULL
)
1849 if (ring
->frame_size
- NL_MMAP_HDRLEN
< size
)
1852 skb
= alloc_skb_head(gfp_mask
);
1856 spin_lock_bh(&sk
->sk_receive_queue
.lock
);
1857 /* check again under lock */
1858 if (ring
->pg_vec
== NULL
)
1861 /* check again under lock */
1862 maxlen
= ring
->frame_size
- NL_MMAP_HDRLEN
;
1866 netlink_forward_ring(ring
);
1867 hdr
= netlink_current_frame(ring
, NL_MMAP_STATUS_UNUSED
);
1870 netlink_ring_setup_skb(skb
, sk
, ring
, hdr
);
1871 netlink_set_status(hdr
, NL_MMAP_STATUS_RESERVED
);
1872 atomic_inc(&ring
->pending
);
1873 netlink_increment_head(ring
);
1875 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
1880 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
1881 netlink_overrun(sk
);
1888 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
1893 return alloc_skb(size
, gfp_mask
);
1895 EXPORT_SYMBOL_GPL(netlink_alloc_skb
);
1897 int netlink_has_listeners(struct sock
*sk
, unsigned int group
)
1900 struct listeners
*listeners
;
1902 BUG_ON(!netlink_is_kernel(sk
));
1905 listeners
= rcu_dereference(nl_table
[sk
->sk_protocol
].listeners
);
1907 if (listeners
&& group
- 1 < nl_table
[sk
->sk_protocol
].groups
)
1908 res
= test_bit(group
- 1, listeners
->masks
);
1914 EXPORT_SYMBOL_GPL(netlink_has_listeners
);
1916 static int netlink_broadcast_deliver(struct sock
*sk
, struct sk_buff
*skb
)
1918 struct netlink_sock
*nlk
= nlk_sk(sk
);
1920 if (atomic_read(&sk
->sk_rmem_alloc
) <= sk
->sk_rcvbuf
&&
1921 !test_bit(NETLINK_S_CONGESTED
, &nlk
->state
)) {
1922 netlink_skb_set_owner_r(skb
, sk
);
1923 __netlink_sendskb(sk
, skb
);
1924 return atomic_read(&sk
->sk_rmem_alloc
) > (sk
->sk_rcvbuf
>> 1);
1929 struct netlink_broadcast_data
{
1930 struct sock
*exclude_sk
;
1935 int delivery_failure
;
1939 struct sk_buff
*skb
, *skb2
;
1940 int (*tx_filter
)(struct sock
*dsk
, struct sk_buff
*skb
, void *data
);
1944 static void do_one_broadcast(struct sock
*sk
,
1945 struct netlink_broadcast_data
*p
)
1947 struct netlink_sock
*nlk
= nlk_sk(sk
);
1950 if (p
->exclude_sk
== sk
)
1953 if (nlk
->portid
== p
->portid
|| p
->group
- 1 >= nlk
->ngroups
||
1954 !test_bit(p
->group
- 1, nlk
->groups
))
1957 if (!net_eq(sock_net(sk
), p
->net
)) {
1958 if (!(nlk
->flags
& NETLINK_F_LISTEN_ALL_NSID
))
1961 if (!peernet_has_id(sock_net(sk
), p
->net
))
1964 if (!file_ns_capable(sk
->sk_socket
->file
, p
->net
->user_ns
,
1970 netlink_overrun(sk
);
1975 if (p
->skb2
== NULL
) {
1976 if (skb_shared(p
->skb
)) {
1977 p
->skb2
= skb_clone(p
->skb
, p
->allocation
);
1979 p
->skb2
= skb_get(p
->skb
);
1981 * skb ownership may have been set when
1982 * delivered to a previous socket.
1984 skb_orphan(p
->skb2
);
1987 if (p
->skb2
== NULL
) {
1988 netlink_overrun(sk
);
1989 /* Clone failed. Notify ALL listeners. */
1991 if (nlk
->flags
& NETLINK_F_BROADCAST_SEND_ERROR
)
1992 p
->delivery_failure
= 1;
1995 if (p
->tx_filter
&& p
->tx_filter(sk
, p
->skb2
, p
->tx_data
)) {
2000 if (sk_filter(sk
, p
->skb2
)) {
2005 NETLINK_CB(p
->skb2
).nsid
= peernet2id(sock_net(sk
), p
->net
);
2006 NETLINK_CB(p
->skb2
).nsid_is_set
= true;
2007 val
= netlink_broadcast_deliver(sk
, p
->skb2
);
2009 netlink_overrun(sk
);
2010 if (nlk
->flags
& NETLINK_F_BROADCAST_SEND_ERROR
)
2011 p
->delivery_failure
= 1;
2013 p
->congested
|= val
;
2021 int netlink_broadcast_filtered(struct sock
*ssk
, struct sk_buff
*skb
, u32 portid
,
2022 u32 group
, gfp_t allocation
,
2023 int (*filter
)(struct sock
*dsk
, struct sk_buff
*skb
, void *data
),
2026 struct net
*net
= sock_net(ssk
);
2027 struct netlink_broadcast_data info
;
2030 skb
= netlink_trim(skb
, allocation
);
2032 info
.exclude_sk
= ssk
;
2034 info
.portid
= portid
;
2037 info
.delivery_failure
= 0;
2040 info
.allocation
= allocation
;
2043 info
.tx_filter
= filter
;
2044 info
.tx_data
= filter_data
;
2046 /* While we sleep in clone, do not allow to change socket list */
2048 netlink_lock_table();
2050 sk_for_each_bound(sk
, &nl_table
[ssk
->sk_protocol
].mc_list
)
2051 do_one_broadcast(sk
, &info
);
2055 netlink_unlock_table();
2057 if (info
.delivery_failure
) {
2058 kfree_skb(info
.skb2
);
2061 consume_skb(info
.skb2
);
2063 if (info
.delivered
) {
2064 if (info
.congested
&& (allocation
& __GFP_WAIT
))
2070 EXPORT_SYMBOL(netlink_broadcast_filtered
);
2072 int netlink_broadcast(struct sock
*ssk
, struct sk_buff
*skb
, u32 portid
,
2073 u32 group
, gfp_t allocation
)
2075 return netlink_broadcast_filtered(ssk
, skb
, portid
, group
, allocation
,
2078 EXPORT_SYMBOL(netlink_broadcast
);
2080 struct netlink_set_err_data
{
2081 struct sock
*exclude_sk
;
2087 static int do_one_set_err(struct sock
*sk
, struct netlink_set_err_data
*p
)
2089 struct netlink_sock
*nlk
= nlk_sk(sk
);
2092 if (sk
== p
->exclude_sk
)
2095 if (!net_eq(sock_net(sk
), sock_net(p
->exclude_sk
)))
2098 if (nlk
->portid
== p
->portid
|| p
->group
- 1 >= nlk
->ngroups
||
2099 !test_bit(p
->group
- 1, nlk
->groups
))
2102 if (p
->code
== ENOBUFS
&& nlk
->flags
& NETLINK_F_RECV_NO_ENOBUFS
) {
2107 sk
->sk_err
= p
->code
;
2108 sk
->sk_error_report(sk
);
2114 * netlink_set_err - report error to broadcast listeners
2115 * @ssk: the kernel netlink socket, as returned by netlink_kernel_create()
2116 * @portid: the PORTID of a process that we want to skip (if any)
2117 * @group: the broadcast group that will notice the error
2118 * @code: error code, must be negative (as usual in kernelspace)
2120 * This function returns the number of broadcast listeners that have set the
2121 * NETLINK_NO_ENOBUFS socket option.
2123 int netlink_set_err(struct sock
*ssk
, u32 portid
, u32 group
, int code
)
2125 struct netlink_set_err_data info
;
2129 info
.exclude_sk
= ssk
;
2130 info
.portid
= portid
;
2132 /* sk->sk_err wants a positive error value */
2135 read_lock(&nl_table_lock
);
2137 sk_for_each_bound(sk
, &nl_table
[ssk
->sk_protocol
].mc_list
)
2138 ret
+= do_one_set_err(sk
, &info
);
2140 read_unlock(&nl_table_lock
);
2143 EXPORT_SYMBOL(netlink_set_err
);
2145 /* must be called with netlink table grabbed */
2146 static void netlink_update_socket_mc(struct netlink_sock
*nlk
,
2150 int old
, new = !!is_new
, subscriptions
;
2152 old
= test_bit(group
- 1, nlk
->groups
);
2153 subscriptions
= nlk
->subscriptions
- old
+ new;
2155 __set_bit(group
- 1, nlk
->groups
);
2157 __clear_bit(group
- 1, nlk
->groups
);
2158 netlink_update_subscriptions(&nlk
->sk
, subscriptions
);
2159 netlink_update_listeners(&nlk
->sk
);
2162 static int netlink_setsockopt(struct socket
*sock
, int level
, int optname
,
2163 char __user
*optval
, unsigned int optlen
)
2165 struct sock
*sk
= sock
->sk
;
2166 struct netlink_sock
*nlk
= nlk_sk(sk
);
2167 unsigned int val
= 0;
2170 if (level
!= SOL_NETLINK
)
2171 return -ENOPROTOOPT
;
2173 if (optname
!= NETLINK_RX_RING
&& optname
!= NETLINK_TX_RING
&&
2174 optlen
>= sizeof(int) &&
2175 get_user(val
, (unsigned int __user
*)optval
))
2179 case NETLINK_PKTINFO
:
2181 nlk
->flags
|= NETLINK_F_RECV_PKTINFO
;
2183 nlk
->flags
&= ~NETLINK_F_RECV_PKTINFO
;
2186 case NETLINK_ADD_MEMBERSHIP
:
2187 case NETLINK_DROP_MEMBERSHIP
: {
2188 if (!netlink_allowed(sock
, NL_CFG_F_NONROOT_RECV
))
2190 err
= netlink_realloc_groups(sk
);
2193 if (!val
|| val
- 1 >= nlk
->ngroups
)
2195 if (optname
== NETLINK_ADD_MEMBERSHIP
&& nlk
->netlink_bind
) {
2196 err
= nlk
->netlink_bind(sock_net(sk
), val
);
2200 netlink_table_grab();
2201 netlink_update_socket_mc(nlk
, val
,
2202 optname
== NETLINK_ADD_MEMBERSHIP
);
2203 netlink_table_ungrab();
2204 if (optname
== NETLINK_DROP_MEMBERSHIP
&& nlk
->netlink_unbind
)
2205 nlk
->netlink_unbind(sock_net(sk
), val
);
2210 case NETLINK_BROADCAST_ERROR
:
2212 nlk
->flags
|= NETLINK_F_BROADCAST_SEND_ERROR
;
2214 nlk
->flags
&= ~NETLINK_F_BROADCAST_SEND_ERROR
;
2217 case NETLINK_NO_ENOBUFS
:
2219 nlk
->flags
|= NETLINK_F_RECV_NO_ENOBUFS
;
2220 clear_bit(NETLINK_S_CONGESTED
, &nlk
->state
);
2221 wake_up_interruptible(&nlk
->wait
);
2223 nlk
->flags
&= ~NETLINK_F_RECV_NO_ENOBUFS
;
2227 #ifdef CONFIG_NETLINK_MMAP
2228 case NETLINK_RX_RING
:
2229 case NETLINK_TX_RING
: {
2230 struct nl_mmap_req req
;
2232 /* Rings might consume more memory than queue limits, require
2235 if (!capable(CAP_NET_ADMIN
))
2237 if (optlen
< sizeof(req
))
2239 if (copy_from_user(&req
, optval
, sizeof(req
)))
2241 err
= netlink_set_ring(sk
, &req
,
2242 optname
== NETLINK_TX_RING
);
2245 #endif /* CONFIG_NETLINK_MMAP */
2246 case NETLINK_LISTEN_ALL_NSID
:
2247 if (!ns_capable(sock_net(sk
)->user_ns
, CAP_NET_BROADCAST
))
2251 nlk
->flags
|= NETLINK_F_LISTEN_ALL_NSID
;
2253 nlk
->flags
&= ~NETLINK_F_LISTEN_ALL_NSID
;
2262 static int netlink_getsockopt(struct socket
*sock
, int level
, int optname
,
2263 char __user
*optval
, int __user
*optlen
)
2265 struct sock
*sk
= sock
->sk
;
2266 struct netlink_sock
*nlk
= nlk_sk(sk
);
2269 if (level
!= SOL_NETLINK
)
2270 return -ENOPROTOOPT
;
2272 if (get_user(len
, optlen
))
2278 case NETLINK_PKTINFO
:
2279 if (len
< sizeof(int))
2282 val
= nlk
->flags
& NETLINK_F_RECV_PKTINFO
? 1 : 0;
2283 if (put_user(len
, optlen
) ||
2284 put_user(val
, optval
))
2288 case NETLINK_BROADCAST_ERROR
:
2289 if (len
< sizeof(int))
2292 val
= nlk
->flags
& NETLINK_F_BROADCAST_SEND_ERROR
? 1 : 0;
2293 if (put_user(len
, optlen
) ||
2294 put_user(val
, optval
))
2298 case NETLINK_NO_ENOBUFS
:
2299 if (len
< sizeof(int))
2302 val
= nlk
->flags
& NETLINK_F_RECV_NO_ENOBUFS
? 1 : 0;
2303 if (put_user(len
, optlen
) ||
2304 put_user(val
, optval
))
2308 case NETLINK_LIST_MEMBERSHIPS
: {
2309 int pos
, idx
, shift
;
2312 netlink_table_grab();
2313 for (pos
= 0; pos
* 8 < nlk
->ngroups
; pos
+= sizeof(u32
)) {
2314 if (len
- pos
< sizeof(u32
))
2317 idx
= pos
/ sizeof(unsigned long);
2318 shift
= (pos
% sizeof(unsigned long)) * 8;
2319 if (put_user((u32
)(nlk
->groups
[idx
] >> shift
),
2320 (u32 __user
*)(optval
+ pos
))) {
2325 if (put_user(ALIGN(nlk
->ngroups
/ 8, sizeof(u32
)), optlen
))
2327 netlink_table_ungrab();
2336 static void netlink_cmsg_recv_pktinfo(struct msghdr
*msg
, struct sk_buff
*skb
)
2338 struct nl_pktinfo info
;
2340 info
.group
= NETLINK_CB(skb
).dst_group
;
2341 put_cmsg(msg
, SOL_NETLINK
, NETLINK_PKTINFO
, sizeof(info
), &info
);
2344 static void netlink_cmsg_listen_all_nsid(struct sock
*sk
, struct msghdr
*msg
,
2345 struct sk_buff
*skb
)
2347 if (!NETLINK_CB(skb
).nsid_is_set
)
2350 put_cmsg(msg
, SOL_NETLINK
, NETLINK_LISTEN_ALL_NSID
, sizeof(int),
2351 &NETLINK_CB(skb
).nsid
);
2354 static int netlink_sendmsg(struct socket
*sock
, struct msghdr
*msg
, size_t len
)
2356 struct sock
*sk
= sock
->sk
;
2357 struct netlink_sock
*nlk
= nlk_sk(sk
);
2358 DECLARE_SOCKADDR(struct sockaddr_nl
*, addr
, msg
->msg_name
);
2361 struct sk_buff
*skb
;
2363 struct scm_cookie scm
;
2364 u32 netlink_skb_flags
= 0;
2366 if (msg
->msg_flags
&MSG_OOB
)
2369 err
= scm_send(sock
, msg
, &scm
, true);
2373 if (msg
->msg_namelen
) {
2375 if (addr
->nl_family
!= AF_NETLINK
)
2377 dst_portid
= addr
->nl_pid
;
2378 dst_group
= ffs(addr
->nl_groups
);
2380 if ((dst_group
|| dst_portid
) &&
2381 !netlink_allowed(sock
, NL_CFG_F_NONROOT_SEND
))
2383 netlink_skb_flags
|= NETLINK_SKB_DST
;
2385 dst_portid
= nlk
->dst_portid
;
2386 dst_group
= nlk
->dst_group
;
2390 err
= netlink_autobind(sock
);
2395 /* It's a really convoluted way for userland to ask for mmaped
2396 * sendmsg(), but that's what we've got...
2398 if (netlink_tx_is_mmaped(sk
) &&
2399 msg
->msg_iter
.type
== ITER_IOVEC
&&
2400 msg
->msg_iter
.nr_segs
== 1 &&
2401 msg
->msg_iter
.iov
->iov_base
== NULL
) {
2402 err
= netlink_mmap_sendmsg(sk
, msg
, dst_portid
, dst_group
,
2408 if (len
> sk
->sk_sndbuf
- 32)
2411 skb
= netlink_alloc_large_skb(len
, dst_group
);
2415 NETLINK_CB(skb
).portid
= nlk
->portid
;
2416 NETLINK_CB(skb
).dst_group
= dst_group
;
2417 NETLINK_CB(skb
).creds
= scm
.creds
;
2418 NETLINK_CB(skb
).flags
= netlink_skb_flags
;
2421 if (memcpy_from_msg(skb_put(skb
, len
), msg
, len
)) {
2426 err
= security_netlink_send(sk
, skb
);
2433 atomic_inc(&skb
->users
);
2434 netlink_broadcast(sk
, skb
, dst_portid
, dst_group
, GFP_KERNEL
);
2436 err
= netlink_unicast(sk
, skb
, dst_portid
, msg
->msg_flags
&MSG_DONTWAIT
);
2443 static int netlink_recvmsg(struct socket
*sock
, struct msghdr
*msg
, size_t len
,
2446 struct scm_cookie scm
;
2447 struct sock
*sk
= sock
->sk
;
2448 struct netlink_sock
*nlk
= nlk_sk(sk
);
2449 int noblock
= flags
&MSG_DONTWAIT
;
2451 struct sk_buff
*skb
, *data_skb
;
2459 skb
= skb_recv_datagram(sk
, flags
, noblock
, &err
);
2465 #ifdef CONFIG_COMPAT_NETLINK_MESSAGES
2466 if (unlikely(skb_shinfo(skb
)->frag_list
)) {
2468 * If this skb has a frag_list, then here that means that we
2469 * will have to use the frag_list skb's data for compat tasks
2470 * and the regular skb's data for normal (non-compat) tasks.
2472 * If we need to send the compat skb, assign it to the
2473 * 'data_skb' variable so that it will be used below for data
2474 * copying. We keep 'skb' for everything else, including
2475 * freeing both later.
2477 if (flags
& MSG_CMSG_COMPAT
)
2478 data_skb
= skb_shinfo(skb
)->frag_list
;
2482 /* Record the max length of recvmsg() calls for future allocations */
2483 nlk
->max_recvmsg_len
= max(nlk
->max_recvmsg_len
, len
);
2484 nlk
->max_recvmsg_len
= min_t(size_t, nlk
->max_recvmsg_len
,
2487 copied
= data_skb
->len
;
2489 msg
->msg_flags
|= MSG_TRUNC
;
2493 skb_reset_transport_header(data_skb
);
2494 err
= skb_copy_datagram_msg(data_skb
, 0, msg
, copied
);
2496 if (msg
->msg_name
) {
2497 DECLARE_SOCKADDR(struct sockaddr_nl
*, addr
, msg
->msg_name
);
2498 addr
->nl_family
= AF_NETLINK
;
2500 addr
->nl_pid
= NETLINK_CB(skb
).portid
;
2501 addr
->nl_groups
= netlink_group_mask(NETLINK_CB(skb
).dst_group
);
2502 msg
->msg_namelen
= sizeof(*addr
);
2505 if (nlk
->flags
& NETLINK_F_RECV_PKTINFO
)
2506 netlink_cmsg_recv_pktinfo(msg
, skb
);
2507 if (nlk
->flags
& NETLINK_F_LISTEN_ALL_NSID
)
2508 netlink_cmsg_listen_all_nsid(sk
, msg
, skb
);
2510 memset(&scm
, 0, sizeof(scm
));
2511 scm
.creds
= *NETLINK_CREDS(skb
);
2512 if (flags
& MSG_TRUNC
)
2513 copied
= data_skb
->len
;
2515 skb_free_datagram(sk
, skb
);
2517 if (nlk
->cb_running
&&
2518 atomic_read(&sk
->sk_rmem_alloc
) <= sk
->sk_rcvbuf
/ 2) {
2519 ret
= netlink_dump(sk
);
2522 sk
->sk_error_report(sk
);
2526 scm_recv(sock
, msg
, &scm
, flags
);
2528 netlink_rcv_wake(sk
);
2529 return err
? : copied
;
2532 static void netlink_data_ready(struct sock
*sk
)
2538 * We export these functions to other modules. They provide a
2539 * complete set of kernel non-blocking support for message
2544 __netlink_kernel_create(struct net
*net
, int unit
, struct module
*module
,
2545 struct netlink_kernel_cfg
*cfg
)
2547 struct socket
*sock
;
2549 struct netlink_sock
*nlk
;
2550 struct listeners
*listeners
= NULL
;
2551 struct mutex
*cb_mutex
= cfg
? cfg
->cb_mutex
: NULL
;
2552 unsigned int groups
;
2556 if (unit
< 0 || unit
>= MAX_LINKS
)
2559 if (sock_create_lite(PF_NETLINK
, SOCK_DGRAM
, unit
, &sock
))
2562 if (__netlink_create(net
, sock
, cb_mutex
, unit
, 1) < 0)
2563 goto out_sock_release_nosk
;
2567 if (!cfg
|| cfg
->groups
< 32)
2570 groups
= cfg
->groups
;
2572 listeners
= kzalloc(sizeof(*listeners
) + NLGRPSZ(groups
), GFP_KERNEL
);
2574 goto out_sock_release
;
2576 sk
->sk_data_ready
= netlink_data_ready
;
2577 if (cfg
&& cfg
->input
)
2578 nlk_sk(sk
)->netlink_rcv
= cfg
->input
;
2580 if (netlink_insert(sk
, 0))
2581 goto out_sock_release
;
2584 nlk
->flags
|= NETLINK_F_KERNEL_SOCKET
;
2586 netlink_table_grab();
2587 if (!nl_table
[unit
].registered
) {
2588 nl_table
[unit
].groups
= groups
;
2589 rcu_assign_pointer(nl_table
[unit
].listeners
, listeners
);
2590 nl_table
[unit
].cb_mutex
= cb_mutex
;
2591 nl_table
[unit
].module
= module
;
2593 nl_table
[unit
].bind
= cfg
->bind
;
2594 nl_table
[unit
].unbind
= cfg
->unbind
;
2595 nl_table
[unit
].flags
= cfg
->flags
;
2597 nl_table
[unit
].compare
= cfg
->compare
;
2599 nl_table
[unit
].registered
= 1;
2602 nl_table
[unit
].registered
++;
2604 netlink_table_ungrab();
2609 netlink_kernel_release(sk
);
2612 out_sock_release_nosk
:
2616 EXPORT_SYMBOL(__netlink_kernel_create
);
2619 netlink_kernel_release(struct sock
*sk
)
2621 if (sk
== NULL
|| sk
->sk_socket
== NULL
)
2624 sock_release(sk
->sk_socket
);
2626 EXPORT_SYMBOL(netlink_kernel_release
);
2628 int __netlink_change_ngroups(struct sock
*sk
, unsigned int groups
)
2630 struct listeners
*new, *old
;
2631 struct netlink_table
*tbl
= &nl_table
[sk
->sk_protocol
];
2636 if (NLGRPSZ(tbl
->groups
) < NLGRPSZ(groups
)) {
2637 new = kzalloc(sizeof(*new) + NLGRPSZ(groups
), GFP_ATOMIC
);
2640 old
= nl_deref_protected(tbl
->listeners
);
2641 memcpy(new->masks
, old
->masks
, NLGRPSZ(tbl
->groups
));
2642 rcu_assign_pointer(tbl
->listeners
, new);
2644 kfree_rcu(old
, rcu
);
2646 tbl
->groups
= groups
;
2652 * netlink_change_ngroups - change number of multicast groups
2654 * This changes the number of multicast groups that are available
2655 * on a certain netlink family. Note that it is not possible to
2656 * change the number of groups to below 32. Also note that it does
2657 * not implicitly call netlink_clear_multicast_users() when the
2658 * number of groups is reduced.
2660 * @sk: The kernel netlink socket, as returned by netlink_kernel_create().
2661 * @groups: The new number of groups.
2663 int netlink_change_ngroups(struct sock
*sk
, unsigned int groups
)
2667 netlink_table_grab();
2668 err
= __netlink_change_ngroups(sk
, groups
);
2669 netlink_table_ungrab();
2674 void __netlink_clear_multicast_users(struct sock
*ksk
, unsigned int group
)
2677 struct netlink_table
*tbl
= &nl_table
[ksk
->sk_protocol
];
2679 sk_for_each_bound(sk
, &tbl
->mc_list
)
2680 netlink_update_socket_mc(nlk_sk(sk
), group
, 0);
2684 __nlmsg_put(struct sk_buff
*skb
, u32 portid
, u32 seq
, int type
, int len
, int flags
)
2686 struct nlmsghdr
*nlh
;
2687 int size
= nlmsg_msg_size(len
);
2689 nlh
= (struct nlmsghdr
*)skb_put(skb
, NLMSG_ALIGN(size
));
2690 nlh
->nlmsg_type
= type
;
2691 nlh
->nlmsg_len
= size
;
2692 nlh
->nlmsg_flags
= flags
;
2693 nlh
->nlmsg_pid
= portid
;
2694 nlh
->nlmsg_seq
= seq
;
2695 if (!__builtin_constant_p(size
) || NLMSG_ALIGN(size
) - size
!= 0)
2696 memset(nlmsg_data(nlh
) + len
, 0, NLMSG_ALIGN(size
) - size
);
2699 EXPORT_SYMBOL(__nlmsg_put
);
2702 * It looks a bit ugly.
2703 * It would be better to create kernel thread.
2706 static int netlink_dump(struct sock
*sk
)
2708 struct netlink_sock
*nlk
= nlk_sk(sk
);
2709 struct netlink_callback
*cb
;
2710 struct sk_buff
*skb
= NULL
;
2711 struct nlmsghdr
*nlh
;
2712 int len
, err
= -ENOBUFS
;
2715 mutex_lock(nlk
->cb_mutex
);
2716 if (!nlk
->cb_running
) {
2722 alloc_size
= max_t(int, cb
->min_dump_alloc
, NLMSG_GOODSIZE
);
2724 if (!netlink_rx_is_mmaped(sk
) &&
2725 atomic_read(&sk
->sk_rmem_alloc
) >= sk
->sk_rcvbuf
)
2728 /* NLMSG_GOODSIZE is small to avoid high order allocations being
2729 * required, but it makes sense to _attempt_ a 16K bytes allocation
2730 * to reduce number of system calls on dump operations, if user
2731 * ever provided a big enough buffer.
2733 if (alloc_size
< nlk
->max_recvmsg_len
) {
2734 skb
= netlink_alloc_skb(sk
,
2735 nlk
->max_recvmsg_len
,
2740 /* available room should be exact amount to avoid MSG_TRUNC */
2742 skb_reserve(skb
, skb_tailroom(skb
) -
2743 nlk
->max_recvmsg_len
);
2746 skb
= netlink_alloc_skb(sk
, alloc_size
, nlk
->portid
,
2750 netlink_skb_set_owner_r(skb
, sk
);
2752 len
= cb
->dump(skb
, cb
);
2755 mutex_unlock(nlk
->cb_mutex
);
2757 if (sk_filter(sk
, skb
))
2760 __netlink_sendskb(sk
, skb
);
2764 nlh
= nlmsg_put_answer(skb
, cb
, NLMSG_DONE
, sizeof(len
), NLM_F_MULTI
);
2768 nl_dump_check_consistent(cb
, nlh
);
2770 memcpy(nlmsg_data(nlh
), &len
, sizeof(len
));
2772 if (sk_filter(sk
, skb
))
2775 __netlink_sendskb(sk
, skb
);
2780 nlk
->cb_running
= false;
2781 mutex_unlock(nlk
->cb_mutex
);
2782 module_put(cb
->module
);
2783 consume_skb(cb
->skb
);
2787 mutex_unlock(nlk
->cb_mutex
);
2792 int __netlink_dump_start(struct sock
*ssk
, struct sk_buff
*skb
,
2793 const struct nlmsghdr
*nlh
,
2794 struct netlink_dump_control
*control
)
2796 struct netlink_callback
*cb
;
2798 struct netlink_sock
*nlk
;
2801 /* Memory mapped dump requests need to be copied to avoid looping
2802 * on the pending state in netlink_mmap_sendmsg() while the CB hold
2803 * a reference to the skb.
2805 if (netlink_skb_is_mmaped(skb
)) {
2806 skb
= skb_copy(skb
, GFP_KERNEL
);
2810 atomic_inc(&skb
->users
);
2812 sk
= netlink_lookup(sock_net(ssk
), ssk
->sk_protocol
, NETLINK_CB(skb
).portid
);
2814 ret
= -ECONNREFUSED
;
2819 mutex_lock(nlk
->cb_mutex
);
2820 /* A dump is in progress... */
2821 if (nlk
->cb_running
) {
2825 /* add reference of module which cb->dump belongs to */
2826 if (!try_module_get(control
->module
)) {
2827 ret
= -EPROTONOSUPPORT
;
2832 memset(cb
, 0, sizeof(*cb
));
2833 cb
->dump
= control
->dump
;
2834 cb
->done
= control
->done
;
2836 cb
->data
= control
->data
;
2837 cb
->module
= control
->module
;
2838 cb
->min_dump_alloc
= control
->min_dump_alloc
;
2841 nlk
->cb_running
= true;
2843 mutex_unlock(nlk
->cb_mutex
);
2845 ret
= netlink_dump(sk
);
2851 /* We successfully started a dump, by returning -EINTR we
2852 * signal not to send ACK even if it was requested.
2858 mutex_unlock(nlk
->cb_mutex
);
2863 EXPORT_SYMBOL(__netlink_dump_start
);
2865 void netlink_ack(struct sk_buff
*in_skb
, struct nlmsghdr
*nlh
, int err
)
2867 struct sk_buff
*skb
;
2868 struct nlmsghdr
*rep
;
2869 struct nlmsgerr
*errmsg
;
2870 size_t payload
= sizeof(*errmsg
);
2872 /* error messages get the original request appened */
2874 payload
+= nlmsg_len(nlh
);
2876 skb
= netlink_alloc_skb(in_skb
->sk
, nlmsg_total_size(payload
),
2877 NETLINK_CB(in_skb
).portid
, GFP_KERNEL
);
2881 sk
= netlink_lookup(sock_net(in_skb
->sk
),
2882 in_skb
->sk
->sk_protocol
,
2883 NETLINK_CB(in_skb
).portid
);
2885 sk
->sk_err
= ENOBUFS
;
2886 sk
->sk_error_report(sk
);
2892 rep
= __nlmsg_put(skb
, NETLINK_CB(in_skb
).portid
, nlh
->nlmsg_seq
,
2893 NLMSG_ERROR
, payload
, 0);
2894 errmsg
= nlmsg_data(rep
);
2895 errmsg
->error
= err
;
2896 memcpy(&errmsg
->msg
, nlh
, err
? nlh
->nlmsg_len
: sizeof(*nlh
));
2897 netlink_unicast(in_skb
->sk
, skb
, NETLINK_CB(in_skb
).portid
, MSG_DONTWAIT
);
2899 EXPORT_SYMBOL(netlink_ack
);
2901 int netlink_rcv_skb(struct sk_buff
*skb
, int (*cb
)(struct sk_buff
*,
2904 struct nlmsghdr
*nlh
;
2907 while (skb
->len
>= nlmsg_total_size(0)) {
2910 nlh
= nlmsg_hdr(skb
);
2913 if (nlh
->nlmsg_len
< NLMSG_HDRLEN
|| skb
->len
< nlh
->nlmsg_len
)
2916 /* Only requests are handled by the kernel */
2917 if (!(nlh
->nlmsg_flags
& NLM_F_REQUEST
))
2920 /* Skip control messages */
2921 if (nlh
->nlmsg_type
< NLMSG_MIN_TYPE
)
2929 if (nlh
->nlmsg_flags
& NLM_F_ACK
|| err
)
2930 netlink_ack(skb
, nlh
, err
);
2933 msglen
= NLMSG_ALIGN(nlh
->nlmsg_len
);
2934 if (msglen
> skb
->len
)
2936 skb_pull(skb
, msglen
);
2941 EXPORT_SYMBOL(netlink_rcv_skb
);
2944 * nlmsg_notify - send a notification netlink message
2945 * @sk: netlink socket to use
2946 * @skb: notification message
2947 * @portid: destination netlink portid for reports or 0
2948 * @group: destination multicast group or 0
2949 * @report: 1 to report back, 0 to disable
2950 * @flags: allocation flags
2952 int nlmsg_notify(struct sock
*sk
, struct sk_buff
*skb
, u32 portid
,
2953 unsigned int group
, int report
, gfp_t flags
)
2958 int exclude_portid
= 0;
2961 atomic_inc(&skb
->users
);
2962 exclude_portid
= portid
;
2965 /* errors reported via destination sk->sk_err, but propagate
2966 * delivery errors if NETLINK_BROADCAST_ERROR flag is set */
2967 err
= nlmsg_multicast(sk
, skb
, exclude_portid
, group
, flags
);
2973 err2
= nlmsg_unicast(sk
, skb
, portid
);
2974 if (!err
|| err
== -ESRCH
)
2980 EXPORT_SYMBOL(nlmsg_notify
);
2982 #ifdef CONFIG_PROC_FS
2983 struct nl_seq_iter
{
2984 struct seq_net_private p
;
2985 struct rhashtable_iter hti
;
2989 static int netlink_walk_start(struct nl_seq_iter
*iter
)
2993 err
= rhashtable_walk_init(&nl_table
[iter
->link
].hash
, &iter
->hti
);
2995 iter
->link
= MAX_LINKS
;
2999 err
= rhashtable_walk_start(&iter
->hti
);
3000 return err
== -EAGAIN
? 0 : err
;
3003 static void netlink_walk_stop(struct nl_seq_iter
*iter
)
3005 rhashtable_walk_stop(&iter
->hti
);
3006 rhashtable_walk_exit(&iter
->hti
);
3009 static void *__netlink_seq_next(struct seq_file
*seq
)
3011 struct nl_seq_iter
*iter
= seq
->private;
3012 struct netlink_sock
*nlk
;
3018 nlk
= rhashtable_walk_next(&iter
->hti
);
3021 if (PTR_ERR(nlk
) == -EAGAIN
)
3030 netlink_walk_stop(iter
);
3031 if (++iter
->link
>= MAX_LINKS
)
3034 err
= netlink_walk_start(iter
);
3036 return ERR_PTR(err
);
3038 } while (sock_net(&nlk
->sk
) != seq_file_net(seq
));
3043 static void *netlink_seq_start(struct seq_file
*seq
, loff_t
*posp
)
3045 struct nl_seq_iter
*iter
= seq
->private;
3046 void *obj
= SEQ_START_TOKEN
;
3052 err
= netlink_walk_start(iter
);
3054 return ERR_PTR(err
);
3056 for (pos
= *posp
; pos
&& obj
&& !IS_ERR(obj
); pos
--)
3057 obj
= __netlink_seq_next(seq
);
3062 static void *netlink_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
3065 return __netlink_seq_next(seq
);
3068 static void netlink_seq_stop(struct seq_file
*seq
, void *v
)
3070 struct nl_seq_iter
*iter
= seq
->private;
3072 if (iter
->link
>= MAX_LINKS
)
3075 netlink_walk_stop(iter
);
3079 static int netlink_seq_show(struct seq_file
*seq
, void *v
)
3081 if (v
== SEQ_START_TOKEN
) {
3083 "sk Eth Pid Groups "
3084 "Rmem Wmem Dump Locks Drops Inode\n");
3087 struct netlink_sock
*nlk
= nlk_sk(s
);
3089 seq_printf(seq
, "%pK %-3d %-6u %08x %-8d %-8d %d %-8d %-8d %-8lu\n",
3093 nlk
->groups
? (u32
)nlk
->groups
[0] : 0,
3094 sk_rmem_alloc_get(s
),
3095 sk_wmem_alloc_get(s
),
3097 atomic_read(&s
->sk_refcnt
),
3098 atomic_read(&s
->sk_drops
),
3106 static const struct seq_operations netlink_seq_ops
= {
3107 .start
= netlink_seq_start
,
3108 .next
= netlink_seq_next
,
3109 .stop
= netlink_seq_stop
,
3110 .show
= netlink_seq_show
,
3114 static int netlink_seq_open(struct inode
*inode
, struct file
*file
)
3116 return seq_open_net(inode
, file
, &netlink_seq_ops
,
3117 sizeof(struct nl_seq_iter
));
3120 static const struct file_operations netlink_seq_fops
= {
3121 .owner
= THIS_MODULE
,
3122 .open
= netlink_seq_open
,
3124 .llseek
= seq_lseek
,
3125 .release
= seq_release_net
,
3130 int netlink_register_notifier(struct notifier_block
*nb
)
3132 return atomic_notifier_chain_register(&netlink_chain
, nb
);
3134 EXPORT_SYMBOL(netlink_register_notifier
);
3136 int netlink_unregister_notifier(struct notifier_block
*nb
)
3138 return atomic_notifier_chain_unregister(&netlink_chain
, nb
);
3140 EXPORT_SYMBOL(netlink_unregister_notifier
);
3142 static const struct proto_ops netlink_ops
= {
3143 .family
= PF_NETLINK
,
3144 .owner
= THIS_MODULE
,
3145 .release
= netlink_release
,
3146 .bind
= netlink_bind
,
3147 .connect
= netlink_connect
,
3148 .socketpair
= sock_no_socketpair
,
3149 .accept
= sock_no_accept
,
3150 .getname
= netlink_getname
,
3151 .poll
= netlink_poll
,
3152 .ioctl
= sock_no_ioctl
,
3153 .listen
= sock_no_listen
,
3154 .shutdown
= sock_no_shutdown
,
3155 .setsockopt
= netlink_setsockopt
,
3156 .getsockopt
= netlink_getsockopt
,
3157 .sendmsg
= netlink_sendmsg
,
3158 .recvmsg
= netlink_recvmsg
,
3159 .mmap
= netlink_mmap
,
3160 .sendpage
= sock_no_sendpage
,
3163 static const struct net_proto_family netlink_family_ops
= {
3164 .family
= PF_NETLINK
,
3165 .create
= netlink_create
,
3166 .owner
= THIS_MODULE
, /* for consistency 8) */
3169 static int __net_init
netlink_net_init(struct net
*net
)
3171 #ifdef CONFIG_PROC_FS
3172 if (!proc_create("netlink", 0, net
->proc_net
, &netlink_seq_fops
))
3178 static void __net_exit
netlink_net_exit(struct net
*net
)
3180 #ifdef CONFIG_PROC_FS
3181 remove_proc_entry("netlink", net
->proc_net
);
3185 static void __init
netlink_add_usersock_entry(void)
3187 struct listeners
*listeners
;
3190 listeners
= kzalloc(sizeof(*listeners
) + NLGRPSZ(groups
), GFP_KERNEL
);
3192 panic("netlink_add_usersock_entry: Cannot allocate listeners\n");
3194 netlink_table_grab();
3196 nl_table
[NETLINK_USERSOCK
].groups
= groups
;
3197 rcu_assign_pointer(nl_table
[NETLINK_USERSOCK
].listeners
, listeners
);
3198 nl_table
[NETLINK_USERSOCK
].module
= THIS_MODULE
;
3199 nl_table
[NETLINK_USERSOCK
].registered
= 1;
3200 nl_table
[NETLINK_USERSOCK
].flags
= NL_CFG_F_NONROOT_SEND
;
3202 netlink_table_ungrab();
3205 static struct pernet_operations __net_initdata netlink_net_ops
= {
3206 .init
= netlink_net_init
,
3207 .exit
= netlink_net_exit
,
3210 static inline u32
netlink_hash(const void *data
, u32 len
, u32 seed
)
3212 const struct netlink_sock
*nlk
= data
;
3213 struct netlink_compare_arg arg
;
3215 netlink_compare_arg_init(&arg
, sock_net(&nlk
->sk
), nlk
->portid
);
3216 return jhash2((u32
*)&arg
, netlink_compare_arg_len
/ sizeof(u32
), seed
);
3219 static const struct rhashtable_params netlink_rhashtable_params
= {
3220 .head_offset
= offsetof(struct netlink_sock
, node
),
3221 .key_len
= netlink_compare_arg_len
,
3222 .obj_hashfn
= netlink_hash
,
3223 .obj_cmpfn
= netlink_compare
,
3224 .automatic_shrinking
= true,
3227 static int __init
netlink_proto_init(void)
3230 int err
= proto_register(&netlink_proto
, 0);
3235 BUILD_BUG_ON(sizeof(struct netlink_skb_parms
) > FIELD_SIZEOF(struct sk_buff
, cb
));
3237 nl_table
= kcalloc(MAX_LINKS
, sizeof(*nl_table
), GFP_KERNEL
);
3241 for (i
= 0; i
< MAX_LINKS
; i
++) {
3242 if (rhashtable_init(&nl_table
[i
].hash
,
3243 &netlink_rhashtable_params
) < 0) {
3245 rhashtable_destroy(&nl_table
[i
].hash
);
3251 INIT_LIST_HEAD(&netlink_tap_all
);
3253 netlink_add_usersock_entry();
3255 sock_register(&netlink_family_ops
);
3256 register_pernet_subsys(&netlink_net_ops
);
3257 /* The netlink device handler may be needed early. */
3262 panic("netlink_init: Cannot allocate nl_table\n");
3265 core_initcall(netlink_proto_init
);