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 <asm/cacheflush.h>
63 #include <net/net_namespace.h>
66 #include <net/netlink.h>
68 #include "af_netlink.h"
72 unsigned long masks
[0];
76 #define NETLINK_CONGESTED 0x0
79 #define NETLINK_KERNEL_SOCKET 0x1
80 #define NETLINK_RECV_PKTINFO 0x2
81 #define NETLINK_BROADCAST_SEND_ERROR 0x4
82 #define NETLINK_RECV_NO_ENOBUFS 0x8
84 static inline int netlink_is_kernel(struct sock
*sk
)
86 return nlk_sk(sk
)->flags
& NETLINK_KERNEL_SOCKET
;
89 struct netlink_table
*nl_table
;
90 EXPORT_SYMBOL_GPL(nl_table
);
92 static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait
);
94 static int netlink_dump(struct sock
*sk
);
95 static void netlink_skb_destructor(struct sk_buff
*skb
);
97 DEFINE_RWLOCK(nl_table_lock
);
98 EXPORT_SYMBOL_GPL(nl_table_lock
);
99 static atomic_t nl_table_users
= ATOMIC_INIT(0);
101 #define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock));
103 static ATOMIC_NOTIFIER_HEAD(netlink_chain
);
105 static DEFINE_SPINLOCK(netlink_tap_lock
);
106 static struct list_head netlink_tap_all __read_mostly
;
108 static inline u32
netlink_group_mask(u32 group
)
110 return group
? 1 << (group
- 1) : 0;
113 static inline struct hlist_head
*nl_portid_hashfn(struct nl_portid_hash
*hash
, u32 portid
)
115 return &hash
->table
[jhash_1word(portid
, hash
->rnd
) & hash
->mask
];
118 int netlink_add_tap(struct netlink_tap
*nt
)
120 if (unlikely(nt
->dev
->type
!= ARPHRD_NETLINK
))
123 spin_lock(&netlink_tap_lock
);
124 list_add_rcu(&nt
->list
, &netlink_tap_all
);
125 spin_unlock(&netlink_tap_lock
);
128 __module_get(nt
->module
);
132 EXPORT_SYMBOL_GPL(netlink_add_tap
);
134 static int __netlink_remove_tap(struct netlink_tap
*nt
)
137 struct netlink_tap
*tmp
;
139 spin_lock(&netlink_tap_lock
);
141 list_for_each_entry(tmp
, &netlink_tap_all
, list
) {
143 list_del_rcu(&nt
->list
);
149 pr_warn("__netlink_remove_tap: %p not found\n", nt
);
151 spin_unlock(&netlink_tap_lock
);
153 if (found
&& nt
->module
)
154 module_put(nt
->module
);
156 return found
? 0 : -ENODEV
;
159 int netlink_remove_tap(struct netlink_tap
*nt
)
163 ret
= __netlink_remove_tap(nt
);
168 EXPORT_SYMBOL_GPL(netlink_remove_tap
);
170 static bool netlink_filter_tap(const struct sk_buff
*skb
)
172 struct sock
*sk
= skb
->sk
;
175 /* We take the more conservative approach and
176 * whitelist socket protocols that may pass.
178 switch (sk
->sk_protocol
) {
180 case NETLINK_USERSOCK
:
181 case NETLINK_SOCK_DIAG
:
184 case NETLINK_FIB_LOOKUP
:
185 case NETLINK_NETFILTER
:
186 case NETLINK_GENERIC
:
194 static int __netlink_deliver_tap_skb(struct sk_buff
*skb
,
195 struct net_device
*dev
)
197 struct sk_buff
*nskb
;
198 struct sock
*sk
= skb
->sk
;
202 nskb
= skb_clone(skb
, GFP_ATOMIC
);
205 nskb
->protocol
= htons((u16
) sk
->sk_protocol
);
206 nskb
->pkt_type
= netlink_is_kernel(sk
) ?
207 PACKET_KERNEL
: PACKET_USER
;
209 ret
= dev_queue_xmit(nskb
);
210 if (unlikely(ret
> 0))
211 ret
= net_xmit_errno(ret
);
218 static void __netlink_deliver_tap(struct sk_buff
*skb
)
221 struct netlink_tap
*tmp
;
223 if (!netlink_filter_tap(skb
))
226 list_for_each_entry_rcu(tmp
, &netlink_tap_all
, list
) {
227 ret
= __netlink_deliver_tap_skb(skb
, tmp
->dev
);
233 static void netlink_deliver_tap(struct sk_buff
*skb
)
237 if (unlikely(!list_empty(&netlink_tap_all
)))
238 __netlink_deliver_tap(skb
);
243 static void netlink_deliver_tap_kernel(struct sock
*dst
, struct sock
*src
,
246 if (!(netlink_is_kernel(dst
) && netlink_is_kernel(src
)))
247 netlink_deliver_tap(skb
);
250 static void netlink_overrun(struct sock
*sk
)
252 struct netlink_sock
*nlk
= nlk_sk(sk
);
254 if (!(nlk
->flags
& NETLINK_RECV_NO_ENOBUFS
)) {
255 if (!test_and_set_bit(NETLINK_CONGESTED
, &nlk_sk(sk
)->state
)) {
256 sk
->sk_err
= ENOBUFS
;
257 sk
->sk_error_report(sk
);
260 atomic_inc(&sk
->sk_drops
);
263 static void netlink_rcv_wake(struct sock
*sk
)
265 struct netlink_sock
*nlk
= nlk_sk(sk
);
267 if (skb_queue_empty(&sk
->sk_receive_queue
))
268 clear_bit(NETLINK_CONGESTED
, &nlk
->state
);
269 if (!test_bit(NETLINK_CONGESTED
, &nlk
->state
))
270 wake_up_interruptible(&nlk
->wait
);
273 #ifdef CONFIG_NETLINK_MMAP
274 static bool netlink_skb_is_mmaped(const struct sk_buff
*skb
)
276 return NETLINK_CB(skb
).flags
& NETLINK_SKB_MMAPED
;
279 static bool netlink_rx_is_mmaped(struct sock
*sk
)
281 return nlk_sk(sk
)->rx_ring
.pg_vec
!= NULL
;
284 static bool netlink_tx_is_mmaped(struct sock
*sk
)
286 return nlk_sk(sk
)->tx_ring
.pg_vec
!= NULL
;
289 static __pure
struct page
*pgvec_to_page(const void *addr
)
291 if (is_vmalloc_addr(addr
))
292 return vmalloc_to_page(addr
);
294 return virt_to_page(addr
);
297 static void free_pg_vec(void **pg_vec
, unsigned int order
, unsigned int len
)
301 for (i
= 0; i
< len
; i
++) {
302 if (pg_vec
[i
] != NULL
) {
303 if (is_vmalloc_addr(pg_vec
[i
]))
306 free_pages((unsigned long)pg_vec
[i
], order
);
312 static void *alloc_one_pg_vec_page(unsigned long order
)
315 gfp_t gfp_flags
= GFP_KERNEL
| __GFP_COMP
| __GFP_ZERO
|
316 __GFP_NOWARN
| __GFP_NORETRY
;
318 buffer
= (void *)__get_free_pages(gfp_flags
, order
);
322 buffer
= vzalloc((1 << order
) * PAGE_SIZE
);
326 gfp_flags
&= ~__GFP_NORETRY
;
327 return (void *)__get_free_pages(gfp_flags
, order
);
330 static void **alloc_pg_vec(struct netlink_sock
*nlk
,
331 struct nl_mmap_req
*req
, unsigned int order
)
333 unsigned int block_nr
= req
->nm_block_nr
;
337 pg_vec
= kcalloc(block_nr
, sizeof(void *), GFP_KERNEL
);
341 for (i
= 0; i
< block_nr
; i
++) {
342 pg_vec
[i
] = alloc_one_pg_vec_page(order
);
343 if (pg_vec
[i
] == NULL
)
349 free_pg_vec(pg_vec
, order
, block_nr
);
353 static int netlink_set_ring(struct sock
*sk
, struct nl_mmap_req
*req
,
354 bool closing
, bool tx_ring
)
356 struct netlink_sock
*nlk
= nlk_sk(sk
);
357 struct netlink_ring
*ring
;
358 struct sk_buff_head
*queue
;
359 void **pg_vec
= NULL
;
360 unsigned int order
= 0;
363 ring
= tx_ring
? &nlk
->tx_ring
: &nlk
->rx_ring
;
364 queue
= tx_ring
? &sk
->sk_write_queue
: &sk
->sk_receive_queue
;
367 if (atomic_read(&nlk
->mapped
))
369 if (atomic_read(&ring
->pending
))
373 if (req
->nm_block_nr
) {
374 if (ring
->pg_vec
!= NULL
)
377 if ((int)req
->nm_block_size
<= 0)
379 if (!IS_ALIGNED(req
->nm_block_size
, PAGE_SIZE
))
381 if (req
->nm_frame_size
< NL_MMAP_HDRLEN
)
383 if (!IS_ALIGNED(req
->nm_frame_size
, NL_MMAP_MSG_ALIGNMENT
))
386 ring
->frames_per_block
= req
->nm_block_size
/
388 if (ring
->frames_per_block
== 0)
390 if (ring
->frames_per_block
* req
->nm_block_nr
!=
394 order
= get_order(req
->nm_block_size
);
395 pg_vec
= alloc_pg_vec(nlk
, req
, order
);
399 if (req
->nm_frame_nr
)
404 mutex_lock(&nlk
->pg_vec_lock
);
405 if (closing
|| atomic_read(&nlk
->mapped
) == 0) {
407 spin_lock_bh(&queue
->lock
);
409 ring
->frame_max
= req
->nm_frame_nr
- 1;
411 ring
->frame_size
= req
->nm_frame_size
;
412 ring
->pg_vec_pages
= req
->nm_block_size
/ PAGE_SIZE
;
414 swap(ring
->pg_vec_len
, req
->nm_block_nr
);
415 swap(ring
->pg_vec_order
, order
);
416 swap(ring
->pg_vec
, pg_vec
);
418 __skb_queue_purge(queue
);
419 spin_unlock_bh(&queue
->lock
);
421 WARN_ON(atomic_read(&nlk
->mapped
));
423 mutex_unlock(&nlk
->pg_vec_lock
);
426 free_pg_vec(pg_vec
, order
, req
->nm_block_nr
);
430 static void netlink_mm_open(struct vm_area_struct
*vma
)
432 struct file
*file
= vma
->vm_file
;
433 struct socket
*sock
= file
->private_data
;
434 struct sock
*sk
= sock
->sk
;
437 atomic_inc(&nlk_sk(sk
)->mapped
);
440 static void netlink_mm_close(struct vm_area_struct
*vma
)
442 struct file
*file
= vma
->vm_file
;
443 struct socket
*sock
= file
->private_data
;
444 struct sock
*sk
= sock
->sk
;
447 atomic_dec(&nlk_sk(sk
)->mapped
);
450 static const struct vm_operations_struct netlink_mmap_ops
= {
451 .open
= netlink_mm_open
,
452 .close
= netlink_mm_close
,
455 static int netlink_mmap(struct file
*file
, struct socket
*sock
,
456 struct vm_area_struct
*vma
)
458 struct sock
*sk
= sock
->sk
;
459 struct netlink_sock
*nlk
= nlk_sk(sk
);
460 struct netlink_ring
*ring
;
461 unsigned long start
, size
, expected
;
468 mutex_lock(&nlk
->pg_vec_lock
);
471 for (ring
= &nlk
->rx_ring
; ring
<= &nlk
->tx_ring
; ring
++) {
472 if (ring
->pg_vec
== NULL
)
474 expected
+= ring
->pg_vec_len
* ring
->pg_vec_pages
* PAGE_SIZE
;
480 size
= vma
->vm_end
- vma
->vm_start
;
481 if (size
!= expected
)
484 start
= vma
->vm_start
;
485 for (ring
= &nlk
->rx_ring
; ring
<= &nlk
->tx_ring
; ring
++) {
486 if (ring
->pg_vec
== NULL
)
489 for (i
= 0; i
< ring
->pg_vec_len
; i
++) {
491 void *kaddr
= ring
->pg_vec
[i
];
494 for (pg_num
= 0; pg_num
< ring
->pg_vec_pages
; pg_num
++) {
495 page
= pgvec_to_page(kaddr
);
496 err
= vm_insert_page(vma
, start
, page
);
505 atomic_inc(&nlk
->mapped
);
506 vma
->vm_ops
= &netlink_mmap_ops
;
509 mutex_unlock(&nlk
->pg_vec_lock
);
513 static void netlink_frame_flush_dcache(const struct nl_mmap_hdr
*hdr
)
515 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
516 struct page
*p_start
, *p_end
;
518 /* First page is flushed through netlink_{get,set}_status */
519 p_start
= pgvec_to_page(hdr
+ PAGE_SIZE
);
520 p_end
= pgvec_to_page((void *)hdr
+ NL_MMAP_HDRLEN
+ hdr
->nm_len
- 1);
521 while (p_start
<= p_end
) {
522 flush_dcache_page(p_start
);
528 static enum nl_mmap_status
netlink_get_status(const struct nl_mmap_hdr
*hdr
)
531 flush_dcache_page(pgvec_to_page(hdr
));
532 return hdr
->nm_status
;
535 static void netlink_set_status(struct nl_mmap_hdr
*hdr
,
536 enum nl_mmap_status status
)
538 hdr
->nm_status
= status
;
539 flush_dcache_page(pgvec_to_page(hdr
));
543 static struct nl_mmap_hdr
*
544 __netlink_lookup_frame(const struct netlink_ring
*ring
, unsigned int pos
)
546 unsigned int pg_vec_pos
, frame_off
;
548 pg_vec_pos
= pos
/ ring
->frames_per_block
;
549 frame_off
= pos
% ring
->frames_per_block
;
551 return ring
->pg_vec
[pg_vec_pos
] + (frame_off
* ring
->frame_size
);
554 static struct nl_mmap_hdr
*
555 netlink_lookup_frame(const struct netlink_ring
*ring
, unsigned int pos
,
556 enum nl_mmap_status status
)
558 struct nl_mmap_hdr
*hdr
;
560 hdr
= __netlink_lookup_frame(ring
, pos
);
561 if (netlink_get_status(hdr
) != status
)
567 static struct nl_mmap_hdr
*
568 netlink_current_frame(const struct netlink_ring
*ring
,
569 enum nl_mmap_status status
)
571 return netlink_lookup_frame(ring
, ring
->head
, status
);
574 static struct nl_mmap_hdr
*
575 netlink_previous_frame(const struct netlink_ring
*ring
,
576 enum nl_mmap_status status
)
580 prev
= ring
->head
? ring
->head
- 1 : ring
->frame_max
;
581 return netlink_lookup_frame(ring
, prev
, status
);
584 static void netlink_increment_head(struct netlink_ring
*ring
)
586 ring
->head
= ring
->head
!= ring
->frame_max
? ring
->head
+ 1 : 0;
589 static void netlink_forward_ring(struct netlink_ring
*ring
)
591 unsigned int head
= ring
->head
, pos
= head
;
592 const struct nl_mmap_hdr
*hdr
;
595 hdr
= __netlink_lookup_frame(ring
, pos
);
596 if (hdr
->nm_status
== NL_MMAP_STATUS_UNUSED
)
598 if (hdr
->nm_status
!= NL_MMAP_STATUS_SKIP
)
600 netlink_increment_head(ring
);
601 } while (ring
->head
!= head
);
604 static bool netlink_dump_space(struct netlink_sock
*nlk
)
606 struct netlink_ring
*ring
= &nlk
->rx_ring
;
607 struct nl_mmap_hdr
*hdr
;
610 hdr
= netlink_current_frame(ring
, NL_MMAP_STATUS_UNUSED
);
614 n
= ring
->head
+ ring
->frame_max
/ 2;
615 if (n
> ring
->frame_max
)
616 n
-= ring
->frame_max
;
618 hdr
= __netlink_lookup_frame(ring
, n
);
620 return hdr
->nm_status
== NL_MMAP_STATUS_UNUSED
;
623 static unsigned int netlink_poll(struct file
*file
, struct socket
*sock
,
626 struct sock
*sk
= sock
->sk
;
627 struct netlink_sock
*nlk
= nlk_sk(sk
);
631 if (nlk
->rx_ring
.pg_vec
!= NULL
) {
632 /* Memory mapped sockets don't call recvmsg(), so flow control
633 * for dumps is performed here. A dump is allowed to continue
634 * if at least half the ring is unused.
636 while (nlk
->cb_running
&& netlink_dump_space(nlk
)) {
637 err
= netlink_dump(sk
);
640 sk
->sk_error_report(sk
);
644 netlink_rcv_wake(sk
);
647 mask
= datagram_poll(file
, sock
, wait
);
649 spin_lock_bh(&sk
->sk_receive_queue
.lock
);
650 if (nlk
->rx_ring
.pg_vec
) {
651 netlink_forward_ring(&nlk
->rx_ring
);
652 if (!netlink_previous_frame(&nlk
->rx_ring
, NL_MMAP_STATUS_UNUSED
))
653 mask
|= POLLIN
| POLLRDNORM
;
655 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
657 spin_lock_bh(&sk
->sk_write_queue
.lock
);
658 if (nlk
->tx_ring
.pg_vec
) {
659 if (netlink_current_frame(&nlk
->tx_ring
, NL_MMAP_STATUS_UNUSED
))
660 mask
|= POLLOUT
| POLLWRNORM
;
662 spin_unlock_bh(&sk
->sk_write_queue
.lock
);
667 static struct nl_mmap_hdr
*netlink_mmap_hdr(struct sk_buff
*skb
)
669 return (struct nl_mmap_hdr
*)(skb
->head
- NL_MMAP_HDRLEN
);
672 static void netlink_ring_setup_skb(struct sk_buff
*skb
, struct sock
*sk
,
673 struct netlink_ring
*ring
,
674 struct nl_mmap_hdr
*hdr
)
679 size
= ring
->frame_size
- NL_MMAP_HDRLEN
;
680 data
= (void *)hdr
+ NL_MMAP_HDRLEN
;
684 skb_reset_tail_pointer(skb
);
685 skb
->end
= skb
->tail
+ size
;
688 skb
->destructor
= netlink_skb_destructor
;
689 NETLINK_CB(skb
).flags
|= NETLINK_SKB_MMAPED
;
690 NETLINK_CB(skb
).sk
= sk
;
693 static int netlink_mmap_sendmsg(struct sock
*sk
, struct msghdr
*msg
,
694 u32 dst_portid
, u32 dst_group
,
695 struct sock_iocb
*siocb
)
697 struct netlink_sock
*nlk
= nlk_sk(sk
);
698 struct netlink_ring
*ring
;
699 struct nl_mmap_hdr
*hdr
;
703 int err
= 0, len
= 0;
705 /* Netlink messages are validated by the receiver before processing.
706 * In order to avoid userspace changing the contents of the message
707 * after validation, the socket and the ring may only be used by a
708 * single process, otherwise we fall back to copying.
710 if (atomic_long_read(&sk
->sk_socket
->file
->f_count
) > 2 ||
711 atomic_read(&nlk
->mapped
) > 1)
714 mutex_lock(&nlk
->pg_vec_lock
);
716 ring
= &nlk
->tx_ring
;
717 maxlen
= ring
->frame_size
- NL_MMAP_HDRLEN
;
720 hdr
= netlink_current_frame(ring
, NL_MMAP_STATUS_VALID
);
722 if (!(msg
->msg_flags
& MSG_DONTWAIT
) &&
723 atomic_read(&nlk
->tx_ring
.pending
))
727 if (hdr
->nm_len
> maxlen
) {
732 netlink_frame_flush_dcache(hdr
);
734 if (likely(dst_portid
== 0 && dst_group
== 0 && excl
)) {
735 skb
= alloc_skb_head(GFP_KERNEL
);
741 netlink_ring_setup_skb(skb
, sk
, ring
, hdr
);
742 NETLINK_CB(skb
).flags
|= NETLINK_SKB_TX
;
743 __skb_put(skb
, hdr
->nm_len
);
744 netlink_set_status(hdr
, NL_MMAP_STATUS_RESERVED
);
745 atomic_inc(&ring
->pending
);
747 skb
= alloc_skb(hdr
->nm_len
, GFP_KERNEL
);
752 __skb_put(skb
, hdr
->nm_len
);
753 memcpy(skb
->data
, (void *)hdr
+ NL_MMAP_HDRLEN
, hdr
->nm_len
);
754 netlink_set_status(hdr
, NL_MMAP_STATUS_UNUSED
);
757 netlink_increment_head(ring
);
759 NETLINK_CB(skb
).portid
= nlk
->portid
;
760 NETLINK_CB(skb
).dst_group
= dst_group
;
761 NETLINK_CB(skb
).creds
= siocb
->scm
->creds
;
763 err
= security_netlink_send(sk
, skb
);
769 if (unlikely(dst_group
)) {
770 atomic_inc(&skb
->users
);
771 netlink_broadcast(sk
, skb
, dst_portid
, dst_group
,
774 err
= netlink_unicast(sk
, skb
, dst_portid
,
775 msg
->msg_flags
& MSG_DONTWAIT
);
780 } while (hdr
!= NULL
||
781 (!(msg
->msg_flags
& MSG_DONTWAIT
) &&
782 atomic_read(&nlk
->tx_ring
.pending
)));
787 mutex_unlock(&nlk
->pg_vec_lock
);
791 static void netlink_queue_mmaped_skb(struct sock
*sk
, struct sk_buff
*skb
)
793 struct nl_mmap_hdr
*hdr
;
795 hdr
= netlink_mmap_hdr(skb
);
796 hdr
->nm_len
= skb
->len
;
797 hdr
->nm_group
= NETLINK_CB(skb
).dst_group
;
798 hdr
->nm_pid
= NETLINK_CB(skb
).creds
.pid
;
799 hdr
->nm_uid
= from_kuid(sk_user_ns(sk
), NETLINK_CB(skb
).creds
.uid
);
800 hdr
->nm_gid
= from_kgid(sk_user_ns(sk
), NETLINK_CB(skb
).creds
.gid
);
801 netlink_frame_flush_dcache(hdr
);
802 netlink_set_status(hdr
, NL_MMAP_STATUS_VALID
);
804 NETLINK_CB(skb
).flags
|= NETLINK_SKB_DELIVERED
;
808 static void netlink_ring_set_copied(struct sock
*sk
, struct sk_buff
*skb
)
810 struct netlink_sock
*nlk
= nlk_sk(sk
);
811 struct netlink_ring
*ring
= &nlk
->rx_ring
;
812 struct nl_mmap_hdr
*hdr
;
814 spin_lock_bh(&sk
->sk_receive_queue
.lock
);
815 hdr
= netlink_current_frame(ring
, NL_MMAP_STATUS_UNUSED
);
817 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
822 netlink_increment_head(ring
);
823 __skb_queue_tail(&sk
->sk_receive_queue
, skb
);
824 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
826 hdr
->nm_len
= skb
->len
;
827 hdr
->nm_group
= NETLINK_CB(skb
).dst_group
;
828 hdr
->nm_pid
= NETLINK_CB(skb
).creds
.pid
;
829 hdr
->nm_uid
= from_kuid(sk_user_ns(sk
), NETLINK_CB(skb
).creds
.uid
);
830 hdr
->nm_gid
= from_kgid(sk_user_ns(sk
), NETLINK_CB(skb
).creds
.gid
);
831 netlink_set_status(hdr
, NL_MMAP_STATUS_COPY
);
834 #else /* CONFIG_NETLINK_MMAP */
835 #define netlink_skb_is_mmaped(skb) false
836 #define netlink_rx_is_mmaped(sk) false
837 #define netlink_tx_is_mmaped(sk) false
838 #define netlink_mmap sock_no_mmap
839 #define netlink_poll datagram_poll
840 #define netlink_mmap_sendmsg(sk, msg, dst_portid, dst_group, siocb) 0
841 #endif /* CONFIG_NETLINK_MMAP */
843 static void netlink_skb_destructor(struct sk_buff
*skb
)
845 #ifdef CONFIG_NETLINK_MMAP
846 struct nl_mmap_hdr
*hdr
;
847 struct netlink_ring
*ring
;
850 /* If a packet from the kernel to userspace was freed because of an
851 * error without being delivered to userspace, the kernel must reset
852 * the status. In the direction userspace to kernel, the status is
853 * always reset here after the packet was processed and freed.
855 if (netlink_skb_is_mmaped(skb
)) {
856 hdr
= netlink_mmap_hdr(skb
);
857 sk
= NETLINK_CB(skb
).sk
;
859 if (NETLINK_CB(skb
).flags
& NETLINK_SKB_TX
) {
860 netlink_set_status(hdr
, NL_MMAP_STATUS_UNUSED
);
861 ring
= &nlk_sk(sk
)->tx_ring
;
863 if (!(NETLINK_CB(skb
).flags
& NETLINK_SKB_DELIVERED
)) {
865 netlink_set_status(hdr
, NL_MMAP_STATUS_VALID
);
867 ring
= &nlk_sk(sk
)->rx_ring
;
870 WARN_ON(atomic_read(&ring
->pending
) == 0);
871 atomic_dec(&ring
->pending
);
877 if (is_vmalloc_addr(skb
->head
)) {
879 !atomic_dec_return(&(skb_shinfo(skb
)->dataref
)))
888 static void netlink_skb_set_owner_r(struct sk_buff
*skb
, struct sock
*sk
)
890 WARN_ON(skb
->sk
!= NULL
);
892 skb
->destructor
= netlink_skb_destructor
;
893 atomic_add(skb
->truesize
, &sk
->sk_rmem_alloc
);
894 sk_mem_charge(sk
, skb
->truesize
);
897 static void netlink_sock_destruct(struct sock
*sk
)
899 struct netlink_sock
*nlk
= nlk_sk(sk
);
901 if (nlk
->cb_running
) {
903 nlk
->cb
.done(&nlk
->cb
);
905 module_put(nlk
->cb
.module
);
906 kfree_skb(nlk
->cb
.skb
);
909 skb_queue_purge(&sk
->sk_receive_queue
);
910 #ifdef CONFIG_NETLINK_MMAP
912 struct nl_mmap_req req
;
914 memset(&req
, 0, sizeof(req
));
915 if (nlk
->rx_ring
.pg_vec
)
916 netlink_set_ring(sk
, &req
, true, false);
917 memset(&req
, 0, sizeof(req
));
918 if (nlk
->tx_ring
.pg_vec
)
919 netlink_set_ring(sk
, &req
, true, true);
921 #endif /* CONFIG_NETLINK_MMAP */
923 if (!sock_flag(sk
, SOCK_DEAD
)) {
924 printk(KERN_ERR
"Freeing alive netlink socket %p\n", sk
);
928 WARN_ON(atomic_read(&sk
->sk_rmem_alloc
));
929 WARN_ON(atomic_read(&sk
->sk_wmem_alloc
));
930 WARN_ON(nlk_sk(sk
)->groups
);
933 /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on
934 * SMP. Look, when several writers sleep and reader wakes them up, all but one
935 * immediately hit write lock and grab all the cpus. Exclusive sleep solves
936 * this, _but_ remember, it adds useless work on UP machines.
939 void netlink_table_grab(void)
940 __acquires(nl_table_lock
)
944 write_lock_irq(&nl_table_lock
);
946 if (atomic_read(&nl_table_users
)) {
947 DECLARE_WAITQUEUE(wait
, current
);
949 add_wait_queue_exclusive(&nl_table_wait
, &wait
);
951 set_current_state(TASK_UNINTERRUPTIBLE
);
952 if (atomic_read(&nl_table_users
) == 0)
954 write_unlock_irq(&nl_table_lock
);
956 write_lock_irq(&nl_table_lock
);
959 __set_current_state(TASK_RUNNING
);
960 remove_wait_queue(&nl_table_wait
, &wait
);
964 void netlink_table_ungrab(void)
965 __releases(nl_table_lock
)
967 write_unlock_irq(&nl_table_lock
);
968 wake_up(&nl_table_wait
);
972 netlink_lock_table(void)
974 /* read_lock() synchronizes us to netlink_table_grab */
976 read_lock(&nl_table_lock
);
977 atomic_inc(&nl_table_users
);
978 read_unlock(&nl_table_lock
);
982 netlink_unlock_table(void)
984 if (atomic_dec_and_test(&nl_table_users
))
985 wake_up(&nl_table_wait
);
988 static bool netlink_compare(struct net
*net
, struct sock
*sk
)
990 return net_eq(sock_net(sk
), net
);
993 static struct sock
*netlink_lookup(struct net
*net
, int protocol
, u32 portid
)
995 struct netlink_table
*table
= &nl_table
[protocol
];
996 struct nl_portid_hash
*hash
= &table
->hash
;
997 struct hlist_head
*head
;
1000 read_lock(&nl_table_lock
);
1001 head
= nl_portid_hashfn(hash
, portid
);
1002 sk_for_each(sk
, head
) {
1003 if (table
->compare(net
, sk
) &&
1004 (nlk_sk(sk
)->portid
== portid
)) {
1011 read_unlock(&nl_table_lock
);
1015 static struct hlist_head
*nl_portid_hash_zalloc(size_t size
)
1017 if (size
<= PAGE_SIZE
)
1018 return kzalloc(size
, GFP_ATOMIC
);
1020 return (struct hlist_head
*)
1021 __get_free_pages(GFP_ATOMIC
| __GFP_ZERO
,
1025 static void nl_portid_hash_free(struct hlist_head
*table
, size_t size
)
1027 if (size
<= PAGE_SIZE
)
1030 free_pages((unsigned long)table
, get_order(size
));
1033 static int nl_portid_hash_rehash(struct nl_portid_hash
*hash
, int grow
)
1035 unsigned int omask
, mask
, shift
;
1037 struct hlist_head
*otable
, *table
;
1040 omask
= mask
= hash
->mask
;
1041 osize
= size
= (mask
+ 1) * sizeof(*table
);
1042 shift
= hash
->shift
;
1045 if (++shift
> hash
->max_shift
)
1047 mask
= mask
* 2 + 1;
1051 table
= nl_portid_hash_zalloc(size
);
1055 otable
= hash
->table
;
1056 hash
->table
= table
;
1058 hash
->shift
= shift
;
1059 get_random_bytes(&hash
->rnd
, sizeof(hash
->rnd
));
1061 for (i
= 0; i
<= omask
; i
++) {
1063 struct hlist_node
*tmp
;
1065 sk_for_each_safe(sk
, tmp
, &otable
[i
])
1066 __sk_add_node(sk
, nl_portid_hashfn(hash
, nlk_sk(sk
)->portid
));
1069 nl_portid_hash_free(otable
, osize
);
1070 hash
->rehash_time
= jiffies
+ 10 * 60 * HZ
;
1074 static inline int nl_portid_hash_dilute(struct nl_portid_hash
*hash
, int len
)
1076 int avg
= hash
->entries
>> hash
->shift
;
1078 if (unlikely(avg
> 1) && nl_portid_hash_rehash(hash
, 1))
1081 if (unlikely(len
> avg
) && time_after(jiffies
, hash
->rehash_time
)) {
1082 nl_portid_hash_rehash(hash
, 0);
1089 static const struct proto_ops netlink_ops
;
1092 netlink_update_listeners(struct sock
*sk
)
1094 struct netlink_table
*tbl
= &nl_table
[sk
->sk_protocol
];
1097 struct listeners
*listeners
;
1099 listeners
= nl_deref_protected(tbl
->listeners
);
1103 for (i
= 0; i
< NLGRPLONGS(tbl
->groups
); i
++) {
1105 sk_for_each_bound(sk
, &tbl
->mc_list
) {
1106 if (i
< NLGRPLONGS(nlk_sk(sk
)->ngroups
))
1107 mask
|= nlk_sk(sk
)->groups
[i
];
1109 listeners
->masks
[i
] = mask
;
1111 /* this function is only called with the netlink table "grabbed", which
1112 * makes sure updates are visible before bind or setsockopt return. */
1115 static int netlink_insert(struct sock
*sk
, struct net
*net
, u32 portid
)
1117 struct netlink_table
*table
= &nl_table
[sk
->sk_protocol
];
1118 struct nl_portid_hash
*hash
= &table
->hash
;
1119 struct hlist_head
*head
;
1120 int err
= -EADDRINUSE
;
1124 netlink_table_grab();
1125 head
= nl_portid_hashfn(hash
, portid
);
1127 sk_for_each(osk
, head
) {
1128 if (table
->compare(net
, osk
) &&
1129 (nlk_sk(osk
)->portid
== portid
))
1137 if (nlk_sk(sk
)->portid
)
1141 if (BITS_PER_LONG
> 32 && unlikely(hash
->entries
>= UINT_MAX
))
1144 if (len
&& nl_portid_hash_dilute(hash
, len
))
1145 head
= nl_portid_hashfn(hash
, portid
);
1147 nlk_sk(sk
)->portid
= portid
;
1148 sk_add_node(sk
, head
);
1152 netlink_table_ungrab();
1156 static void netlink_remove(struct sock
*sk
)
1158 netlink_table_grab();
1159 if (sk_del_node_init(sk
))
1160 nl_table
[sk
->sk_protocol
].hash
.entries
--;
1161 if (nlk_sk(sk
)->subscriptions
)
1162 __sk_del_bind_node(sk
);
1163 netlink_table_ungrab();
1166 static struct proto netlink_proto
= {
1168 .owner
= THIS_MODULE
,
1169 .obj_size
= sizeof(struct netlink_sock
),
1172 static int __netlink_create(struct net
*net
, struct socket
*sock
,
1173 struct mutex
*cb_mutex
, int protocol
)
1176 struct netlink_sock
*nlk
;
1178 sock
->ops
= &netlink_ops
;
1180 sk
= sk_alloc(net
, PF_NETLINK
, GFP_KERNEL
, &netlink_proto
);
1184 sock_init_data(sock
, sk
);
1188 nlk
->cb_mutex
= cb_mutex
;
1190 nlk
->cb_mutex
= &nlk
->cb_def_mutex
;
1191 mutex_init(nlk
->cb_mutex
);
1193 init_waitqueue_head(&nlk
->wait
);
1194 #ifdef CONFIG_NETLINK_MMAP
1195 mutex_init(&nlk
->pg_vec_lock
);
1198 sk
->sk_destruct
= netlink_sock_destruct
;
1199 sk
->sk_protocol
= protocol
;
1203 static int netlink_create(struct net
*net
, struct socket
*sock
, int protocol
,
1206 struct module
*module
= NULL
;
1207 struct mutex
*cb_mutex
;
1208 struct netlink_sock
*nlk
;
1209 int (*bind
)(int group
);
1210 void (*unbind
)(int group
);
1213 sock
->state
= SS_UNCONNECTED
;
1215 if (sock
->type
!= SOCK_RAW
&& sock
->type
!= SOCK_DGRAM
)
1216 return -ESOCKTNOSUPPORT
;
1218 if (protocol
< 0 || protocol
>= MAX_LINKS
)
1219 return -EPROTONOSUPPORT
;
1221 netlink_lock_table();
1222 #ifdef CONFIG_MODULES
1223 if (!nl_table
[protocol
].registered
) {
1224 netlink_unlock_table();
1225 request_module("net-pf-%d-proto-%d", PF_NETLINK
, protocol
);
1226 netlink_lock_table();
1229 if (nl_table
[protocol
].registered
&&
1230 try_module_get(nl_table
[protocol
].module
))
1231 module
= nl_table
[protocol
].module
;
1233 err
= -EPROTONOSUPPORT
;
1234 cb_mutex
= nl_table
[protocol
].cb_mutex
;
1235 bind
= nl_table
[protocol
].bind
;
1236 unbind
= nl_table
[protocol
].unbind
;
1237 netlink_unlock_table();
1242 err
= __netlink_create(net
, sock
, cb_mutex
, protocol
);
1247 sock_prot_inuse_add(net
, &netlink_proto
, 1);
1250 nlk
= nlk_sk(sock
->sk
);
1251 nlk
->module
= module
;
1252 nlk
->netlink_bind
= bind
;
1253 nlk
->netlink_unbind
= unbind
;
1262 static int netlink_release(struct socket
*sock
)
1264 struct sock
*sk
= sock
->sk
;
1265 struct netlink_sock
*nlk
;
1275 * OK. Socket is unlinked, any packets that arrive now
1280 wake_up_interruptible_all(&nlk
->wait
);
1282 skb_queue_purge(&sk
->sk_write_queue
);
1285 struct netlink_notify n
= {
1286 .net
= sock_net(sk
),
1287 .protocol
= sk
->sk_protocol
,
1288 .portid
= nlk
->portid
,
1290 atomic_notifier_call_chain(&netlink_chain
,
1291 NETLINK_URELEASE
, &n
);
1294 module_put(nlk
->module
);
1296 netlink_table_grab();
1297 if (netlink_is_kernel(sk
)) {
1298 BUG_ON(nl_table
[sk
->sk_protocol
].registered
== 0);
1299 if (--nl_table
[sk
->sk_protocol
].registered
== 0) {
1300 struct listeners
*old
;
1302 old
= nl_deref_protected(nl_table
[sk
->sk_protocol
].listeners
);
1303 RCU_INIT_POINTER(nl_table
[sk
->sk_protocol
].listeners
, NULL
);
1304 kfree_rcu(old
, rcu
);
1305 nl_table
[sk
->sk_protocol
].module
= NULL
;
1306 nl_table
[sk
->sk_protocol
].bind
= NULL
;
1307 nl_table
[sk
->sk_protocol
].unbind
= NULL
;
1308 nl_table
[sk
->sk_protocol
].flags
= 0;
1309 nl_table
[sk
->sk_protocol
].registered
= 0;
1311 } else if (nlk
->subscriptions
) {
1312 netlink_update_listeners(sk
);
1314 netlink_table_ungrab();
1320 sock_prot_inuse_add(sock_net(sk
), &netlink_proto
, -1);
1326 static int netlink_autobind(struct socket
*sock
)
1328 struct sock
*sk
= sock
->sk
;
1329 struct net
*net
= sock_net(sk
);
1330 struct netlink_table
*table
= &nl_table
[sk
->sk_protocol
];
1331 struct nl_portid_hash
*hash
= &table
->hash
;
1332 struct hlist_head
*head
;
1334 s32 portid
= task_tgid_vnr(current
);
1336 static s32 rover
= -4097;
1340 netlink_table_grab();
1341 head
= nl_portid_hashfn(hash
, portid
);
1342 sk_for_each(osk
, head
) {
1343 if (!table
->compare(net
, osk
))
1345 if (nlk_sk(osk
)->portid
== portid
) {
1346 /* Bind collision, search negative portid values. */
1350 netlink_table_ungrab();
1354 netlink_table_ungrab();
1356 err
= netlink_insert(sk
, net
, portid
);
1357 if (err
== -EADDRINUSE
)
1360 /* If 2 threads race to autobind, that is fine. */
1368 * __netlink_ns_capable - General netlink message capability test
1369 * @nsp: NETLINK_CB of the 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 netlink_skb_parms
*nsp
,
1378 struct user_namespace
*user_ns
, int cap
)
1380 return sk_ns_capable(nsp
->sk
, user_ns
, cap
);
1382 EXPORT_SYMBOL(__netlink_ns_capable
);
1385 * netlink_ns_capable - General netlink message capability test
1386 * @skb: socket buffer holding a netlink command from userspace
1387 * @user_ns: The user namespace of the capability to use
1388 * @cap: The capability to use
1390 * Test to see if the opener of the socket we received the message
1391 * from had when the netlink socket was created and the sender of the
1392 * message has has the capability @cap in the user namespace @user_ns.
1394 bool netlink_ns_capable(const struct sk_buff
*skb
,
1395 struct user_namespace
*user_ns
, int cap
)
1397 return __netlink_ns_capable(&NETLINK_CB(skb
), user_ns
, cap
);
1399 EXPORT_SYMBOL(netlink_ns_capable
);
1402 * netlink_capable - Netlink global message capability test
1403 * @skb: socket buffer holding a netlink command from userspace
1404 * @cap: The capability to use
1406 * Test to see if the opener of the socket we received the message
1407 * from had when the netlink socket was created and the sender of the
1408 * message has has the capability @cap in all user namespaces.
1410 bool netlink_capable(const struct sk_buff
*skb
, int cap
)
1412 return netlink_ns_capable(skb
, &init_user_ns
, cap
);
1414 EXPORT_SYMBOL(netlink_capable
);
1417 * netlink_net_capable - Netlink network namespace message capability test
1418 * @skb: socket buffer holding a netlink command from userspace
1419 * @cap: The capability to use
1421 * Test to see if the opener of the socket we received the message
1422 * from had when the netlink socket was created and the sender of the
1423 * message has has the capability @cap over the network namespace of
1424 * the socket we received the message from.
1426 bool netlink_net_capable(const struct sk_buff
*skb
, int cap
)
1428 return netlink_ns_capable(skb
, sock_net(skb
->sk
)->user_ns
, cap
);
1430 EXPORT_SYMBOL(netlink_net_capable
);
1432 static inline int netlink_allowed(const struct socket
*sock
, unsigned int flag
)
1434 return (nl_table
[sock
->sk
->sk_protocol
].flags
& flag
) ||
1435 ns_capable(sock_net(sock
->sk
)->user_ns
, CAP_NET_ADMIN
);
1439 netlink_update_subscriptions(struct sock
*sk
, unsigned int subscriptions
)
1441 struct netlink_sock
*nlk
= nlk_sk(sk
);
1443 if (nlk
->subscriptions
&& !subscriptions
)
1444 __sk_del_bind_node(sk
);
1445 else if (!nlk
->subscriptions
&& subscriptions
)
1446 sk_add_bind_node(sk
, &nl_table
[sk
->sk_protocol
].mc_list
);
1447 nlk
->subscriptions
= subscriptions
;
1450 static int netlink_realloc_groups(struct sock
*sk
)
1452 struct netlink_sock
*nlk
= nlk_sk(sk
);
1453 unsigned int groups
;
1454 unsigned long *new_groups
;
1457 netlink_table_grab();
1459 groups
= nl_table
[sk
->sk_protocol
].groups
;
1460 if (!nl_table
[sk
->sk_protocol
].registered
) {
1465 if (nlk
->ngroups
>= groups
)
1468 new_groups
= krealloc(nlk
->groups
, NLGRPSZ(groups
), GFP_ATOMIC
);
1469 if (new_groups
== NULL
) {
1473 memset((char *)new_groups
+ NLGRPSZ(nlk
->ngroups
), 0,
1474 NLGRPSZ(groups
) - NLGRPSZ(nlk
->ngroups
));
1476 nlk
->groups
= new_groups
;
1477 nlk
->ngroups
= groups
;
1479 netlink_table_ungrab();
1483 static void netlink_unbind(int group
, long unsigned int groups
,
1484 struct netlink_sock
*nlk
)
1488 if (!nlk
->netlink_unbind
)
1491 for (undo
= 0; undo
< group
; undo
++)
1492 if (test_bit(group
, &groups
))
1493 nlk
->netlink_unbind(undo
);
1496 static int netlink_bind(struct socket
*sock
, struct sockaddr
*addr
,
1499 struct sock
*sk
= sock
->sk
;
1500 struct net
*net
= sock_net(sk
);
1501 struct netlink_sock
*nlk
= nlk_sk(sk
);
1502 struct sockaddr_nl
*nladdr
= (struct sockaddr_nl
*)addr
;
1504 long unsigned int groups
= nladdr
->nl_groups
;
1506 if (addr_len
< sizeof(struct sockaddr_nl
))
1509 if (nladdr
->nl_family
!= AF_NETLINK
)
1512 /* Only superuser is allowed to listen multicasts */
1514 if (!netlink_allowed(sock
, NL_CFG_F_NONROOT_RECV
))
1516 err
= netlink_realloc_groups(sk
);
1522 if (nladdr
->nl_pid
!= nlk
->portid
)
1525 if (nlk
->netlink_bind
&& groups
) {
1528 for (group
= 0; group
< nlk
->ngroups
; group
++) {
1529 if (!test_bit(group
, &groups
))
1531 err
= nlk
->netlink_bind(group
);
1534 netlink_unbind(group
, groups
, nlk
);
1540 err
= nladdr
->nl_pid
?
1541 netlink_insert(sk
, net
, nladdr
->nl_pid
) :
1542 netlink_autobind(sock
);
1544 netlink_unbind(nlk
->ngroups
- 1, groups
, nlk
);
1549 if (!groups
&& (nlk
->groups
== NULL
|| !(u32
)nlk
->groups
[0]))
1552 netlink_table_grab();
1553 netlink_update_subscriptions(sk
, nlk
->subscriptions
+
1555 hweight32(nlk
->groups
[0]));
1556 nlk
->groups
[0] = (nlk
->groups
[0] & ~0xffffffffUL
) | groups
;
1557 netlink_update_listeners(sk
);
1558 netlink_table_ungrab();
1563 static int netlink_connect(struct socket
*sock
, struct sockaddr
*addr
,
1564 int alen
, int flags
)
1567 struct sock
*sk
= sock
->sk
;
1568 struct netlink_sock
*nlk
= nlk_sk(sk
);
1569 struct sockaddr_nl
*nladdr
= (struct sockaddr_nl
*)addr
;
1571 if (alen
< sizeof(addr
->sa_family
))
1574 if (addr
->sa_family
== AF_UNSPEC
) {
1575 sk
->sk_state
= NETLINK_UNCONNECTED
;
1576 nlk
->dst_portid
= 0;
1580 if (addr
->sa_family
!= AF_NETLINK
)
1583 if ((nladdr
->nl_groups
|| nladdr
->nl_pid
) &&
1584 !netlink_allowed(sock
, NL_CFG_F_NONROOT_SEND
))
1588 err
= netlink_autobind(sock
);
1591 sk
->sk_state
= NETLINK_CONNECTED
;
1592 nlk
->dst_portid
= nladdr
->nl_pid
;
1593 nlk
->dst_group
= ffs(nladdr
->nl_groups
);
1599 static int netlink_getname(struct socket
*sock
, struct sockaddr
*addr
,
1600 int *addr_len
, int peer
)
1602 struct sock
*sk
= sock
->sk
;
1603 struct netlink_sock
*nlk
= nlk_sk(sk
);
1604 DECLARE_SOCKADDR(struct sockaddr_nl
*, nladdr
, addr
);
1606 nladdr
->nl_family
= AF_NETLINK
;
1608 *addr_len
= sizeof(*nladdr
);
1611 nladdr
->nl_pid
= nlk
->dst_portid
;
1612 nladdr
->nl_groups
= netlink_group_mask(nlk
->dst_group
);
1614 nladdr
->nl_pid
= nlk
->portid
;
1615 nladdr
->nl_groups
= nlk
->groups
? nlk
->groups
[0] : 0;
1620 static struct sock
*netlink_getsockbyportid(struct sock
*ssk
, u32 portid
)
1623 struct netlink_sock
*nlk
;
1625 sock
= netlink_lookup(sock_net(ssk
), ssk
->sk_protocol
, portid
);
1627 return ERR_PTR(-ECONNREFUSED
);
1629 /* Don't bother queuing skb if kernel socket has no input function */
1631 if (sock
->sk_state
== NETLINK_CONNECTED
&&
1632 nlk
->dst_portid
!= nlk_sk(ssk
)->portid
) {
1634 return ERR_PTR(-ECONNREFUSED
);
1639 struct sock
*netlink_getsockbyfilp(struct file
*filp
)
1641 struct inode
*inode
= file_inode(filp
);
1644 if (!S_ISSOCK(inode
->i_mode
))
1645 return ERR_PTR(-ENOTSOCK
);
1647 sock
= SOCKET_I(inode
)->sk
;
1648 if (sock
->sk_family
!= AF_NETLINK
)
1649 return ERR_PTR(-EINVAL
);
1655 static struct sk_buff
*netlink_alloc_large_skb(unsigned int size
,
1658 struct sk_buff
*skb
;
1661 if (size
<= NLMSG_GOODSIZE
|| broadcast
)
1662 return alloc_skb(size
, GFP_KERNEL
);
1664 size
= SKB_DATA_ALIGN(size
) +
1665 SKB_DATA_ALIGN(sizeof(struct skb_shared_info
));
1667 data
= vmalloc(size
);
1671 skb
= build_skb(data
, size
);
1676 skb
->destructor
= netlink_skb_destructor
;
1683 * Attach a skb to a netlink socket.
1684 * The caller must hold a reference to the destination socket. On error, the
1685 * reference is dropped. The skb is not send to the destination, just all
1686 * all error checks are performed and memory in the queue is reserved.
1688 * < 0: error. skb freed, reference to sock dropped.
1690 * 1: repeat lookup - reference dropped while waiting for socket memory.
1692 int netlink_attachskb(struct sock
*sk
, struct sk_buff
*skb
,
1693 long *timeo
, struct sock
*ssk
)
1695 struct netlink_sock
*nlk
;
1699 if ((atomic_read(&sk
->sk_rmem_alloc
) > sk
->sk_rcvbuf
||
1700 test_bit(NETLINK_CONGESTED
, &nlk
->state
)) &&
1701 !netlink_skb_is_mmaped(skb
)) {
1702 DECLARE_WAITQUEUE(wait
, current
);
1704 if (!ssk
|| netlink_is_kernel(ssk
))
1705 netlink_overrun(sk
);
1711 __set_current_state(TASK_INTERRUPTIBLE
);
1712 add_wait_queue(&nlk
->wait
, &wait
);
1714 if ((atomic_read(&sk
->sk_rmem_alloc
) > sk
->sk_rcvbuf
||
1715 test_bit(NETLINK_CONGESTED
, &nlk
->state
)) &&
1716 !sock_flag(sk
, SOCK_DEAD
))
1717 *timeo
= schedule_timeout(*timeo
);
1719 __set_current_state(TASK_RUNNING
);
1720 remove_wait_queue(&nlk
->wait
, &wait
);
1723 if (signal_pending(current
)) {
1725 return sock_intr_errno(*timeo
);
1729 netlink_skb_set_owner_r(skb
, sk
);
1733 static int __netlink_sendskb(struct sock
*sk
, struct sk_buff
*skb
)
1737 netlink_deliver_tap(skb
);
1739 #ifdef CONFIG_NETLINK_MMAP
1740 if (netlink_skb_is_mmaped(skb
))
1741 netlink_queue_mmaped_skb(sk
, skb
);
1742 else if (netlink_rx_is_mmaped(sk
))
1743 netlink_ring_set_copied(sk
, skb
);
1745 #endif /* CONFIG_NETLINK_MMAP */
1746 skb_queue_tail(&sk
->sk_receive_queue
, skb
);
1747 sk
->sk_data_ready(sk
);
1751 int netlink_sendskb(struct sock
*sk
, struct sk_buff
*skb
)
1753 int len
= __netlink_sendskb(sk
, skb
);
1759 void netlink_detachskb(struct sock
*sk
, struct sk_buff
*skb
)
1765 static struct sk_buff
*netlink_trim(struct sk_buff
*skb
, gfp_t allocation
)
1769 WARN_ON(skb
->sk
!= NULL
);
1770 if (netlink_skb_is_mmaped(skb
))
1773 delta
= skb
->end
- skb
->tail
;
1774 if (is_vmalloc_addr(skb
->head
) || delta
* 2 < skb
->truesize
)
1777 if (skb_shared(skb
)) {
1778 struct sk_buff
*nskb
= skb_clone(skb
, allocation
);
1785 if (!pskb_expand_head(skb
, 0, -delta
, allocation
))
1786 skb
->truesize
-= delta
;
1791 static int netlink_unicast_kernel(struct sock
*sk
, struct sk_buff
*skb
,
1795 struct netlink_sock
*nlk
= nlk_sk(sk
);
1797 ret
= -ECONNREFUSED
;
1798 if (nlk
->netlink_rcv
!= NULL
) {
1800 netlink_skb_set_owner_r(skb
, sk
);
1801 NETLINK_CB(skb
).sk
= ssk
;
1802 netlink_deliver_tap_kernel(sk
, ssk
, skb
);
1803 nlk
->netlink_rcv(skb
);
1812 int netlink_unicast(struct sock
*ssk
, struct sk_buff
*skb
,
1813 u32 portid
, int nonblock
)
1819 skb
= netlink_trim(skb
, gfp_any());
1821 timeo
= sock_sndtimeo(ssk
, nonblock
);
1823 sk
= netlink_getsockbyportid(ssk
, portid
);
1828 if (netlink_is_kernel(sk
))
1829 return netlink_unicast_kernel(sk
, skb
, ssk
);
1831 if (sk_filter(sk
, skb
)) {
1838 err
= netlink_attachskb(sk
, skb
, &timeo
, ssk
);
1844 return netlink_sendskb(sk
, skb
);
1846 EXPORT_SYMBOL(netlink_unicast
);
1848 struct sk_buff
*netlink_alloc_skb(struct sock
*ssk
, unsigned int size
,
1849 u32 dst_portid
, gfp_t gfp_mask
)
1851 #ifdef CONFIG_NETLINK_MMAP
1852 struct sock
*sk
= NULL
;
1853 struct sk_buff
*skb
;
1854 struct netlink_ring
*ring
;
1855 struct nl_mmap_hdr
*hdr
;
1856 unsigned int maxlen
;
1858 sk
= netlink_getsockbyportid(ssk
, dst_portid
);
1862 ring
= &nlk_sk(sk
)->rx_ring
;
1863 /* fast-path without atomic ops for common case: non-mmaped receiver */
1864 if (ring
->pg_vec
== NULL
)
1867 if (ring
->frame_size
- NL_MMAP_HDRLEN
< size
)
1870 skb
= alloc_skb_head(gfp_mask
);
1874 spin_lock_bh(&sk
->sk_receive_queue
.lock
);
1875 /* check again under lock */
1876 if (ring
->pg_vec
== NULL
)
1879 /* check again under lock */
1880 maxlen
= ring
->frame_size
- NL_MMAP_HDRLEN
;
1884 netlink_forward_ring(ring
);
1885 hdr
= netlink_current_frame(ring
, NL_MMAP_STATUS_UNUSED
);
1888 netlink_ring_setup_skb(skb
, sk
, ring
, hdr
);
1889 netlink_set_status(hdr
, NL_MMAP_STATUS_RESERVED
);
1890 atomic_inc(&ring
->pending
);
1891 netlink_increment_head(ring
);
1893 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
1898 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
1899 netlink_overrun(sk
);
1906 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
1911 return alloc_skb(size
, gfp_mask
);
1913 EXPORT_SYMBOL_GPL(netlink_alloc_skb
);
1915 int netlink_has_listeners(struct sock
*sk
, unsigned int group
)
1918 struct listeners
*listeners
;
1920 BUG_ON(!netlink_is_kernel(sk
));
1923 listeners
= rcu_dereference(nl_table
[sk
->sk_protocol
].listeners
);
1925 if (listeners
&& group
- 1 < nl_table
[sk
->sk_protocol
].groups
)
1926 res
= test_bit(group
- 1, listeners
->masks
);
1932 EXPORT_SYMBOL_GPL(netlink_has_listeners
);
1934 static int netlink_broadcast_deliver(struct sock
*sk
, struct sk_buff
*skb
)
1936 struct netlink_sock
*nlk
= nlk_sk(sk
);
1938 if (atomic_read(&sk
->sk_rmem_alloc
) <= sk
->sk_rcvbuf
&&
1939 !test_bit(NETLINK_CONGESTED
, &nlk
->state
)) {
1940 netlink_skb_set_owner_r(skb
, sk
);
1941 __netlink_sendskb(sk
, skb
);
1942 return atomic_read(&sk
->sk_rmem_alloc
) > (sk
->sk_rcvbuf
>> 1);
1947 struct netlink_broadcast_data
{
1948 struct sock
*exclude_sk
;
1953 int delivery_failure
;
1957 struct sk_buff
*skb
, *skb2
;
1958 int (*tx_filter
)(struct sock
*dsk
, struct sk_buff
*skb
, void *data
);
1962 static int do_one_broadcast(struct sock
*sk
,
1963 struct netlink_broadcast_data
*p
)
1965 struct netlink_sock
*nlk
= nlk_sk(sk
);
1968 if (p
->exclude_sk
== sk
)
1971 if (nlk
->portid
== p
->portid
|| p
->group
- 1 >= nlk
->ngroups
||
1972 !test_bit(p
->group
- 1, nlk
->groups
))
1975 if (!net_eq(sock_net(sk
), p
->net
))
1979 netlink_overrun(sk
);
1984 if (p
->skb2
== NULL
) {
1985 if (skb_shared(p
->skb
)) {
1986 p
->skb2
= skb_clone(p
->skb
, p
->allocation
);
1988 p
->skb2
= skb_get(p
->skb
);
1990 * skb ownership may have been set when
1991 * delivered to a previous socket.
1993 skb_orphan(p
->skb2
);
1996 if (p
->skb2
== NULL
) {
1997 netlink_overrun(sk
);
1998 /* Clone failed. Notify ALL listeners. */
2000 if (nlk
->flags
& NETLINK_BROADCAST_SEND_ERROR
)
2001 p
->delivery_failure
= 1;
2002 } else if (p
->tx_filter
&& p
->tx_filter(sk
, p
->skb2
, p
->tx_data
)) {
2005 } else if (sk_filter(sk
, p
->skb2
)) {
2008 } else if ((val
= netlink_broadcast_deliver(sk
, p
->skb2
)) < 0) {
2009 netlink_overrun(sk
);
2010 if (nlk
->flags
& NETLINK_BROADCAST_SEND_ERROR
)
2011 p
->delivery_failure
= 1;
2013 p
->congested
|= val
;
2023 int netlink_broadcast_filtered(struct sock
*ssk
, struct sk_buff
*skb
, u32 portid
,
2024 u32 group
, gfp_t allocation
,
2025 int (*filter
)(struct sock
*dsk
, struct sk_buff
*skb
, void *data
),
2028 struct net
*net
= sock_net(ssk
);
2029 struct netlink_broadcast_data info
;
2032 skb
= netlink_trim(skb
, allocation
);
2034 info
.exclude_sk
= ssk
;
2036 info
.portid
= portid
;
2039 info
.delivery_failure
= 0;
2042 info
.allocation
= allocation
;
2045 info
.tx_filter
= filter
;
2046 info
.tx_data
= filter_data
;
2048 /* While we sleep in clone, do not allow to change socket list */
2050 netlink_lock_table();
2052 sk_for_each_bound(sk
, &nl_table
[ssk
->sk_protocol
].mc_list
)
2053 do_one_broadcast(sk
, &info
);
2057 netlink_unlock_table();
2059 if (info
.delivery_failure
) {
2060 kfree_skb(info
.skb2
);
2063 consume_skb(info
.skb2
);
2065 if (info
.delivered
) {
2066 if (info
.congested
&& (allocation
& __GFP_WAIT
))
2072 EXPORT_SYMBOL(netlink_broadcast_filtered
);
2074 int netlink_broadcast(struct sock
*ssk
, struct sk_buff
*skb
, u32 portid
,
2075 u32 group
, gfp_t allocation
)
2077 return netlink_broadcast_filtered(ssk
, skb
, portid
, group
, allocation
,
2080 EXPORT_SYMBOL(netlink_broadcast
);
2082 struct netlink_set_err_data
{
2083 struct sock
*exclude_sk
;
2089 static int do_one_set_err(struct sock
*sk
, struct netlink_set_err_data
*p
)
2091 struct netlink_sock
*nlk
= nlk_sk(sk
);
2094 if (sk
== p
->exclude_sk
)
2097 if (!net_eq(sock_net(sk
), sock_net(p
->exclude_sk
)))
2100 if (nlk
->portid
== p
->portid
|| p
->group
- 1 >= nlk
->ngroups
||
2101 !test_bit(p
->group
- 1, nlk
->groups
))
2104 if (p
->code
== ENOBUFS
&& nlk
->flags
& NETLINK_RECV_NO_ENOBUFS
) {
2109 sk
->sk_err
= p
->code
;
2110 sk
->sk_error_report(sk
);
2116 * netlink_set_err - report error to broadcast listeners
2117 * @ssk: the kernel netlink socket, as returned by netlink_kernel_create()
2118 * @portid: the PORTID of a process that we want to skip (if any)
2119 * @group: the broadcast group that will notice the error
2120 * @code: error code, must be negative (as usual in kernelspace)
2122 * This function returns the number of broadcast listeners that have set the
2123 * NETLINK_RECV_NO_ENOBUFS socket option.
2125 int netlink_set_err(struct sock
*ssk
, u32 portid
, u32 group
, int code
)
2127 struct netlink_set_err_data info
;
2131 info
.exclude_sk
= ssk
;
2132 info
.portid
= portid
;
2134 /* sk->sk_err wants a positive error value */
2137 read_lock(&nl_table_lock
);
2139 sk_for_each_bound(sk
, &nl_table
[ssk
->sk_protocol
].mc_list
)
2140 ret
+= do_one_set_err(sk
, &info
);
2142 read_unlock(&nl_table_lock
);
2145 EXPORT_SYMBOL(netlink_set_err
);
2147 /* must be called with netlink table grabbed */
2148 static void netlink_update_socket_mc(struct netlink_sock
*nlk
,
2152 int old
, new = !!is_new
, subscriptions
;
2154 old
= test_bit(group
- 1, nlk
->groups
);
2155 subscriptions
= nlk
->subscriptions
- old
+ new;
2157 __set_bit(group
- 1, nlk
->groups
);
2159 __clear_bit(group
- 1, nlk
->groups
);
2160 netlink_update_subscriptions(&nlk
->sk
, subscriptions
);
2161 netlink_update_listeners(&nlk
->sk
);
2164 static int netlink_setsockopt(struct socket
*sock
, int level
, int optname
,
2165 char __user
*optval
, unsigned int optlen
)
2167 struct sock
*sk
= sock
->sk
;
2168 struct netlink_sock
*nlk
= nlk_sk(sk
);
2169 unsigned int val
= 0;
2172 if (level
!= SOL_NETLINK
)
2173 return -ENOPROTOOPT
;
2175 if (optname
!= NETLINK_RX_RING
&& optname
!= NETLINK_TX_RING
&&
2176 optlen
>= sizeof(int) &&
2177 get_user(val
, (unsigned int __user
*)optval
))
2181 case NETLINK_PKTINFO
:
2183 nlk
->flags
|= NETLINK_RECV_PKTINFO
;
2185 nlk
->flags
&= ~NETLINK_RECV_PKTINFO
;
2188 case NETLINK_ADD_MEMBERSHIP
:
2189 case NETLINK_DROP_MEMBERSHIP
: {
2190 if (!netlink_allowed(sock
, NL_CFG_F_NONROOT_RECV
))
2192 err
= netlink_realloc_groups(sk
);
2195 if (!val
|| val
- 1 >= nlk
->ngroups
)
2197 if (optname
== NETLINK_ADD_MEMBERSHIP
&& nlk
->netlink_bind
) {
2198 err
= nlk
->netlink_bind(val
);
2202 netlink_table_grab();
2203 netlink_update_socket_mc(nlk
, val
,
2204 optname
== NETLINK_ADD_MEMBERSHIP
);
2205 netlink_table_ungrab();
2206 if (optname
== NETLINK_DROP_MEMBERSHIP
&& nlk
->netlink_unbind
)
2207 nlk
->netlink_unbind(val
);
2212 case NETLINK_BROADCAST_ERROR
:
2214 nlk
->flags
|= NETLINK_BROADCAST_SEND_ERROR
;
2216 nlk
->flags
&= ~NETLINK_BROADCAST_SEND_ERROR
;
2219 case NETLINK_NO_ENOBUFS
:
2221 nlk
->flags
|= NETLINK_RECV_NO_ENOBUFS
;
2222 clear_bit(NETLINK_CONGESTED
, &nlk
->state
);
2223 wake_up_interruptible(&nlk
->wait
);
2225 nlk
->flags
&= ~NETLINK_RECV_NO_ENOBUFS
;
2229 #ifdef CONFIG_NETLINK_MMAP
2230 case NETLINK_RX_RING
:
2231 case NETLINK_TX_RING
: {
2232 struct nl_mmap_req req
;
2234 /* Rings might consume more memory than queue limits, require
2237 if (!capable(CAP_NET_ADMIN
))
2239 if (optlen
< sizeof(req
))
2241 if (copy_from_user(&req
, optval
, sizeof(req
)))
2243 err
= netlink_set_ring(sk
, &req
, false,
2244 optname
== NETLINK_TX_RING
);
2247 #endif /* CONFIG_NETLINK_MMAP */
2254 static int netlink_getsockopt(struct socket
*sock
, int level
, int optname
,
2255 char __user
*optval
, int __user
*optlen
)
2257 struct sock
*sk
= sock
->sk
;
2258 struct netlink_sock
*nlk
= nlk_sk(sk
);
2261 if (level
!= SOL_NETLINK
)
2262 return -ENOPROTOOPT
;
2264 if (get_user(len
, optlen
))
2270 case NETLINK_PKTINFO
:
2271 if (len
< sizeof(int))
2274 val
= nlk
->flags
& NETLINK_RECV_PKTINFO
? 1 : 0;
2275 if (put_user(len
, optlen
) ||
2276 put_user(val
, optval
))
2280 case NETLINK_BROADCAST_ERROR
:
2281 if (len
< sizeof(int))
2284 val
= nlk
->flags
& NETLINK_BROADCAST_SEND_ERROR
? 1 : 0;
2285 if (put_user(len
, optlen
) ||
2286 put_user(val
, optval
))
2290 case NETLINK_NO_ENOBUFS
:
2291 if (len
< sizeof(int))
2294 val
= nlk
->flags
& NETLINK_RECV_NO_ENOBUFS
? 1 : 0;
2295 if (put_user(len
, optlen
) ||
2296 put_user(val
, optval
))
2306 static void netlink_cmsg_recv_pktinfo(struct msghdr
*msg
, struct sk_buff
*skb
)
2308 struct nl_pktinfo info
;
2310 info
.group
= NETLINK_CB(skb
).dst_group
;
2311 put_cmsg(msg
, SOL_NETLINK
, NETLINK_PKTINFO
, sizeof(info
), &info
);
2314 static int netlink_sendmsg(struct kiocb
*kiocb
, struct socket
*sock
,
2315 struct msghdr
*msg
, size_t len
)
2317 struct sock_iocb
*siocb
= kiocb_to_siocb(kiocb
);
2318 struct sock
*sk
= sock
->sk
;
2319 struct netlink_sock
*nlk
= nlk_sk(sk
);
2320 DECLARE_SOCKADDR(struct sockaddr_nl
*, addr
, msg
->msg_name
);
2323 struct sk_buff
*skb
;
2325 struct scm_cookie scm
;
2327 if (msg
->msg_flags
&MSG_OOB
)
2330 if (NULL
== siocb
->scm
)
2333 err
= scm_send(sock
, msg
, siocb
->scm
, true);
2337 if (msg
->msg_namelen
) {
2339 if (addr
->nl_family
!= AF_NETLINK
)
2341 dst_portid
= addr
->nl_pid
;
2342 dst_group
= ffs(addr
->nl_groups
);
2344 if ((dst_group
|| dst_portid
) &&
2345 !netlink_allowed(sock
, NL_CFG_F_NONROOT_SEND
))
2348 dst_portid
= nlk
->dst_portid
;
2349 dst_group
= nlk
->dst_group
;
2353 err
= netlink_autobind(sock
);
2358 if (netlink_tx_is_mmaped(sk
) &&
2359 msg
->msg_iov
->iov_base
== NULL
) {
2360 err
= netlink_mmap_sendmsg(sk
, msg
, dst_portid
, dst_group
,
2366 if (len
> sk
->sk_sndbuf
- 32)
2369 skb
= netlink_alloc_large_skb(len
, dst_group
);
2373 NETLINK_CB(skb
).portid
= nlk
->portid
;
2374 NETLINK_CB(skb
).dst_group
= dst_group
;
2375 NETLINK_CB(skb
).creds
= siocb
->scm
->creds
;
2378 if (memcpy_fromiovec(skb_put(skb
, len
), msg
->msg_iov
, len
)) {
2383 err
= security_netlink_send(sk
, skb
);
2390 atomic_inc(&skb
->users
);
2391 netlink_broadcast(sk
, skb
, dst_portid
, dst_group
, GFP_KERNEL
);
2393 err
= netlink_unicast(sk
, skb
, dst_portid
, msg
->msg_flags
&MSG_DONTWAIT
);
2396 scm_destroy(siocb
->scm
);
2400 static int netlink_recvmsg(struct kiocb
*kiocb
, struct socket
*sock
,
2401 struct msghdr
*msg
, size_t len
,
2404 struct sock_iocb
*siocb
= kiocb_to_siocb(kiocb
);
2405 struct scm_cookie scm
;
2406 struct sock
*sk
= sock
->sk
;
2407 struct netlink_sock
*nlk
= nlk_sk(sk
);
2408 int noblock
= flags
&MSG_DONTWAIT
;
2410 struct sk_buff
*skb
, *data_skb
;
2418 skb
= skb_recv_datagram(sk
, flags
, noblock
, &err
);
2424 #ifdef CONFIG_COMPAT_NETLINK_MESSAGES
2425 if (unlikely(skb_shinfo(skb
)->frag_list
)) {
2427 * If this skb has a frag_list, then here that means that we
2428 * will have to use the frag_list skb's data for compat tasks
2429 * and the regular skb's data for normal (non-compat) tasks.
2431 * If we need to send the compat skb, assign it to the
2432 * 'data_skb' variable so that it will be used below for data
2433 * copying. We keep 'skb' for everything else, including
2434 * freeing both later.
2436 if (flags
& MSG_CMSG_COMPAT
)
2437 data_skb
= skb_shinfo(skb
)->frag_list
;
2441 /* Record the max length of recvmsg() calls for future allocations */
2442 nlk
->max_recvmsg_len
= max(nlk
->max_recvmsg_len
, len
);
2443 nlk
->max_recvmsg_len
= min_t(size_t, nlk
->max_recvmsg_len
,
2446 copied
= data_skb
->len
;
2448 msg
->msg_flags
|= MSG_TRUNC
;
2452 skb_reset_transport_header(data_skb
);
2453 err
= skb_copy_datagram_iovec(data_skb
, 0, msg
->msg_iov
, copied
);
2455 if (msg
->msg_name
) {
2456 DECLARE_SOCKADDR(struct sockaddr_nl
*, addr
, msg
->msg_name
);
2457 addr
->nl_family
= AF_NETLINK
;
2459 addr
->nl_pid
= NETLINK_CB(skb
).portid
;
2460 addr
->nl_groups
= netlink_group_mask(NETLINK_CB(skb
).dst_group
);
2461 msg
->msg_namelen
= sizeof(*addr
);
2464 if (nlk
->flags
& NETLINK_RECV_PKTINFO
)
2465 netlink_cmsg_recv_pktinfo(msg
, skb
);
2467 if (NULL
== siocb
->scm
) {
2468 memset(&scm
, 0, sizeof(scm
));
2471 siocb
->scm
->creds
= *NETLINK_CREDS(skb
);
2472 if (flags
& MSG_TRUNC
)
2473 copied
= data_skb
->len
;
2475 skb_free_datagram(sk
, skb
);
2477 if (nlk
->cb_running
&&
2478 atomic_read(&sk
->sk_rmem_alloc
) <= sk
->sk_rcvbuf
/ 2) {
2479 ret
= netlink_dump(sk
);
2482 sk
->sk_error_report(sk
);
2486 scm_recv(sock
, msg
, siocb
->scm
, flags
);
2488 netlink_rcv_wake(sk
);
2489 return err
? : copied
;
2492 static void netlink_data_ready(struct sock
*sk
)
2498 * We export these functions to other modules. They provide a
2499 * complete set of kernel non-blocking support for message
2504 __netlink_kernel_create(struct net
*net
, int unit
, struct module
*module
,
2505 struct netlink_kernel_cfg
*cfg
)
2507 struct socket
*sock
;
2509 struct netlink_sock
*nlk
;
2510 struct listeners
*listeners
= NULL
;
2511 struct mutex
*cb_mutex
= cfg
? cfg
->cb_mutex
: NULL
;
2512 unsigned int groups
;
2516 if (unit
< 0 || unit
>= MAX_LINKS
)
2519 if (sock_create_lite(PF_NETLINK
, SOCK_DGRAM
, unit
, &sock
))
2523 * We have to just have a reference on the net from sk, but don't
2524 * get_net it. Besides, we cannot get and then put the net here.
2525 * So we create one inside init_net and the move it to net.
2528 if (__netlink_create(&init_net
, sock
, cb_mutex
, unit
) < 0)
2529 goto out_sock_release_nosk
;
2532 sk_change_net(sk
, net
);
2534 if (!cfg
|| cfg
->groups
< 32)
2537 groups
= cfg
->groups
;
2539 listeners
= kzalloc(sizeof(*listeners
) + NLGRPSZ(groups
), GFP_KERNEL
);
2541 goto out_sock_release
;
2543 sk
->sk_data_ready
= netlink_data_ready
;
2544 if (cfg
&& cfg
->input
)
2545 nlk_sk(sk
)->netlink_rcv
= cfg
->input
;
2547 if (netlink_insert(sk
, net
, 0))
2548 goto out_sock_release
;
2551 nlk
->flags
|= NETLINK_KERNEL_SOCKET
;
2553 netlink_table_grab();
2554 if (!nl_table
[unit
].registered
) {
2555 nl_table
[unit
].groups
= groups
;
2556 rcu_assign_pointer(nl_table
[unit
].listeners
, listeners
);
2557 nl_table
[unit
].cb_mutex
= cb_mutex
;
2558 nl_table
[unit
].module
= module
;
2560 nl_table
[unit
].bind
= cfg
->bind
;
2561 nl_table
[unit
].flags
= cfg
->flags
;
2563 nl_table
[unit
].compare
= cfg
->compare
;
2565 nl_table
[unit
].registered
= 1;
2568 nl_table
[unit
].registered
++;
2570 netlink_table_ungrab();
2575 netlink_kernel_release(sk
);
2578 out_sock_release_nosk
:
2582 EXPORT_SYMBOL(__netlink_kernel_create
);
2585 netlink_kernel_release(struct sock
*sk
)
2587 sk_release_kernel(sk
);
2589 EXPORT_SYMBOL(netlink_kernel_release
);
2591 int __netlink_change_ngroups(struct sock
*sk
, unsigned int groups
)
2593 struct listeners
*new, *old
;
2594 struct netlink_table
*tbl
= &nl_table
[sk
->sk_protocol
];
2599 if (NLGRPSZ(tbl
->groups
) < NLGRPSZ(groups
)) {
2600 new = kzalloc(sizeof(*new) + NLGRPSZ(groups
), GFP_ATOMIC
);
2603 old
= nl_deref_protected(tbl
->listeners
);
2604 memcpy(new->masks
, old
->masks
, NLGRPSZ(tbl
->groups
));
2605 rcu_assign_pointer(tbl
->listeners
, new);
2607 kfree_rcu(old
, rcu
);
2609 tbl
->groups
= groups
;
2615 * netlink_change_ngroups - change number of multicast groups
2617 * This changes the number of multicast groups that are available
2618 * on a certain netlink family. Note that it is not possible to
2619 * change the number of groups to below 32. Also note that it does
2620 * not implicitly call netlink_clear_multicast_users() when the
2621 * number of groups is reduced.
2623 * @sk: The kernel netlink socket, as returned by netlink_kernel_create().
2624 * @groups: The new number of groups.
2626 int netlink_change_ngroups(struct sock
*sk
, unsigned int groups
)
2630 netlink_table_grab();
2631 err
= __netlink_change_ngroups(sk
, groups
);
2632 netlink_table_ungrab();
2637 void __netlink_clear_multicast_users(struct sock
*ksk
, unsigned int group
)
2640 struct netlink_table
*tbl
= &nl_table
[ksk
->sk_protocol
];
2642 sk_for_each_bound(sk
, &tbl
->mc_list
)
2643 netlink_update_socket_mc(nlk_sk(sk
), group
, 0);
2647 __nlmsg_put(struct sk_buff
*skb
, u32 portid
, u32 seq
, int type
, int len
, int flags
)
2649 struct nlmsghdr
*nlh
;
2650 int size
= nlmsg_msg_size(len
);
2652 nlh
= (struct nlmsghdr
*)skb_put(skb
, NLMSG_ALIGN(size
));
2653 nlh
->nlmsg_type
= type
;
2654 nlh
->nlmsg_len
= size
;
2655 nlh
->nlmsg_flags
= flags
;
2656 nlh
->nlmsg_pid
= portid
;
2657 nlh
->nlmsg_seq
= seq
;
2658 if (!__builtin_constant_p(size
) || NLMSG_ALIGN(size
) - size
!= 0)
2659 memset(nlmsg_data(nlh
) + len
, 0, NLMSG_ALIGN(size
) - size
);
2662 EXPORT_SYMBOL(__nlmsg_put
);
2665 * It looks a bit ugly.
2666 * It would be better to create kernel thread.
2669 static int netlink_dump(struct sock
*sk
)
2671 struct netlink_sock
*nlk
= nlk_sk(sk
);
2672 struct netlink_callback
*cb
;
2673 struct sk_buff
*skb
= NULL
;
2674 struct nlmsghdr
*nlh
;
2675 int len
, err
= -ENOBUFS
;
2678 mutex_lock(nlk
->cb_mutex
);
2679 if (!nlk
->cb_running
) {
2685 alloc_size
= max_t(int, cb
->min_dump_alloc
, NLMSG_GOODSIZE
);
2687 if (!netlink_rx_is_mmaped(sk
) &&
2688 atomic_read(&sk
->sk_rmem_alloc
) >= sk
->sk_rcvbuf
)
2691 /* NLMSG_GOODSIZE is small to avoid high order allocations being
2692 * required, but it makes sense to _attempt_ a 16K bytes allocation
2693 * to reduce number of system calls on dump operations, if user
2694 * ever provided a big enough buffer.
2696 if (alloc_size
< nlk
->max_recvmsg_len
) {
2697 skb
= netlink_alloc_skb(sk
,
2698 nlk
->max_recvmsg_len
,
2703 /* available room should be exact amount to avoid MSG_TRUNC */
2705 skb_reserve(skb
, skb_tailroom(skb
) -
2706 nlk
->max_recvmsg_len
);
2709 skb
= netlink_alloc_skb(sk
, alloc_size
, nlk
->portid
,
2713 netlink_skb_set_owner_r(skb
, sk
);
2715 len
= cb
->dump(skb
, cb
);
2718 mutex_unlock(nlk
->cb_mutex
);
2720 if (sk_filter(sk
, skb
))
2723 __netlink_sendskb(sk
, skb
);
2727 nlh
= nlmsg_put_answer(skb
, cb
, NLMSG_DONE
, sizeof(len
), NLM_F_MULTI
);
2731 nl_dump_check_consistent(cb
, nlh
);
2733 memcpy(nlmsg_data(nlh
), &len
, sizeof(len
));
2735 if (sk_filter(sk
, skb
))
2738 __netlink_sendskb(sk
, skb
);
2743 nlk
->cb_running
= false;
2744 mutex_unlock(nlk
->cb_mutex
);
2745 module_put(cb
->module
);
2746 consume_skb(cb
->skb
);
2750 mutex_unlock(nlk
->cb_mutex
);
2755 int __netlink_dump_start(struct sock
*ssk
, struct sk_buff
*skb
,
2756 const struct nlmsghdr
*nlh
,
2757 struct netlink_dump_control
*control
)
2759 struct netlink_callback
*cb
;
2761 struct netlink_sock
*nlk
;
2764 /* Memory mapped dump requests need to be copied to avoid looping
2765 * on the pending state in netlink_mmap_sendmsg() while the CB hold
2766 * a reference to the skb.
2768 if (netlink_skb_is_mmaped(skb
)) {
2769 skb
= skb_copy(skb
, GFP_KERNEL
);
2773 atomic_inc(&skb
->users
);
2775 sk
= netlink_lookup(sock_net(ssk
), ssk
->sk_protocol
, NETLINK_CB(skb
).portid
);
2777 ret
= -ECONNREFUSED
;
2782 mutex_lock(nlk
->cb_mutex
);
2783 /* A dump is in progress... */
2784 if (nlk
->cb_running
) {
2788 /* add reference of module which cb->dump belongs to */
2789 if (!try_module_get(control
->module
)) {
2790 ret
= -EPROTONOSUPPORT
;
2795 memset(cb
, 0, sizeof(*cb
));
2796 cb
->dump
= control
->dump
;
2797 cb
->done
= control
->done
;
2799 cb
->data
= control
->data
;
2800 cb
->module
= control
->module
;
2801 cb
->min_dump_alloc
= control
->min_dump_alloc
;
2804 nlk
->cb_running
= true;
2806 mutex_unlock(nlk
->cb_mutex
);
2808 ret
= netlink_dump(sk
);
2814 /* We successfully started a dump, by returning -EINTR we
2815 * signal not to send ACK even if it was requested.
2821 mutex_unlock(nlk
->cb_mutex
);
2826 EXPORT_SYMBOL(__netlink_dump_start
);
2828 void netlink_ack(struct sk_buff
*in_skb
, struct nlmsghdr
*nlh
, int err
)
2830 struct sk_buff
*skb
;
2831 struct nlmsghdr
*rep
;
2832 struct nlmsgerr
*errmsg
;
2833 size_t payload
= sizeof(*errmsg
);
2835 /* error messages get the original request appened */
2837 payload
+= nlmsg_len(nlh
);
2839 skb
= netlink_alloc_skb(in_skb
->sk
, nlmsg_total_size(payload
),
2840 NETLINK_CB(in_skb
).portid
, GFP_KERNEL
);
2844 sk
= netlink_lookup(sock_net(in_skb
->sk
),
2845 in_skb
->sk
->sk_protocol
,
2846 NETLINK_CB(in_skb
).portid
);
2848 sk
->sk_err
= ENOBUFS
;
2849 sk
->sk_error_report(sk
);
2855 rep
= __nlmsg_put(skb
, NETLINK_CB(in_skb
).portid
, nlh
->nlmsg_seq
,
2856 NLMSG_ERROR
, payload
, 0);
2857 errmsg
= nlmsg_data(rep
);
2858 errmsg
->error
= err
;
2859 memcpy(&errmsg
->msg
, nlh
, err
? nlh
->nlmsg_len
: sizeof(*nlh
));
2860 netlink_unicast(in_skb
->sk
, skb
, NETLINK_CB(in_skb
).portid
, MSG_DONTWAIT
);
2862 EXPORT_SYMBOL(netlink_ack
);
2864 int netlink_rcv_skb(struct sk_buff
*skb
, int (*cb
)(struct sk_buff
*,
2867 struct nlmsghdr
*nlh
;
2870 while (skb
->len
>= nlmsg_total_size(0)) {
2873 nlh
= nlmsg_hdr(skb
);
2876 if (nlh
->nlmsg_len
< NLMSG_HDRLEN
|| skb
->len
< nlh
->nlmsg_len
)
2879 /* Only requests are handled by the kernel */
2880 if (!(nlh
->nlmsg_flags
& NLM_F_REQUEST
))
2883 /* Skip control messages */
2884 if (nlh
->nlmsg_type
< NLMSG_MIN_TYPE
)
2892 if (nlh
->nlmsg_flags
& NLM_F_ACK
|| err
)
2893 netlink_ack(skb
, nlh
, err
);
2896 msglen
= NLMSG_ALIGN(nlh
->nlmsg_len
);
2897 if (msglen
> skb
->len
)
2899 skb_pull(skb
, msglen
);
2904 EXPORT_SYMBOL(netlink_rcv_skb
);
2907 * nlmsg_notify - send a notification netlink message
2908 * @sk: netlink socket to use
2909 * @skb: notification message
2910 * @portid: destination netlink portid for reports or 0
2911 * @group: destination multicast group or 0
2912 * @report: 1 to report back, 0 to disable
2913 * @flags: allocation flags
2915 int nlmsg_notify(struct sock
*sk
, struct sk_buff
*skb
, u32 portid
,
2916 unsigned int group
, int report
, gfp_t flags
)
2921 int exclude_portid
= 0;
2924 atomic_inc(&skb
->users
);
2925 exclude_portid
= portid
;
2928 /* errors reported via destination sk->sk_err, but propagate
2929 * delivery errors if NETLINK_BROADCAST_ERROR flag is set */
2930 err
= nlmsg_multicast(sk
, skb
, exclude_portid
, group
, flags
);
2936 err2
= nlmsg_unicast(sk
, skb
, portid
);
2937 if (!err
|| err
== -ESRCH
)
2943 EXPORT_SYMBOL(nlmsg_notify
);
2945 #ifdef CONFIG_PROC_FS
2946 struct nl_seq_iter
{
2947 struct seq_net_private p
;
2952 static struct sock
*netlink_seq_socket_idx(struct seq_file
*seq
, loff_t pos
)
2954 struct nl_seq_iter
*iter
= seq
->private;
2959 for (i
= 0; i
< MAX_LINKS
; i
++) {
2960 struct nl_portid_hash
*hash
= &nl_table
[i
].hash
;
2962 for (j
= 0; j
<= hash
->mask
; j
++) {
2963 sk_for_each(s
, &hash
->table
[j
]) {
2964 if (sock_net(s
) != seq_file_net(seq
))
2978 static void *netlink_seq_start(struct seq_file
*seq
, loff_t
*pos
)
2979 __acquires(nl_table_lock
)
2981 read_lock(&nl_table_lock
);
2982 return *pos
? netlink_seq_socket_idx(seq
, *pos
- 1) : SEQ_START_TOKEN
;
2985 static void *netlink_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
2988 struct nl_seq_iter
*iter
;
2994 if (v
== SEQ_START_TOKEN
)
2995 return netlink_seq_socket_idx(seq
, 0);
2997 net
= seq_file_net(seq
);
2998 iter
= seq
->private;
3002 } while (s
&& !nl_table
[s
->sk_protocol
].compare(net
, s
));
3007 j
= iter
->hash_idx
+ 1;
3010 struct nl_portid_hash
*hash
= &nl_table
[i
].hash
;
3012 for (; j
<= hash
->mask
; j
++) {
3013 s
= sk_head(&hash
->table
[j
]);
3015 while (s
&& !nl_table
[s
->sk_protocol
].compare(net
, s
))
3025 } while (++i
< MAX_LINKS
);
3030 static void netlink_seq_stop(struct seq_file
*seq
, void *v
)
3031 __releases(nl_table_lock
)
3033 read_unlock(&nl_table_lock
);
3037 static int netlink_seq_show(struct seq_file
*seq
, void *v
)
3039 if (v
== SEQ_START_TOKEN
) {
3041 "sk Eth Pid Groups "
3042 "Rmem Wmem Dump Locks Drops Inode\n");
3045 struct netlink_sock
*nlk
= nlk_sk(s
);
3047 seq_printf(seq
, "%pK %-3d %-6u %08x %-8d %-8d %d %-8d %-8d %-8lu\n",
3051 nlk
->groups
? (u32
)nlk
->groups
[0] : 0,
3052 sk_rmem_alloc_get(s
),
3053 sk_wmem_alloc_get(s
),
3055 atomic_read(&s
->sk_refcnt
),
3056 atomic_read(&s
->sk_drops
),
3064 static const struct seq_operations netlink_seq_ops
= {
3065 .start
= netlink_seq_start
,
3066 .next
= netlink_seq_next
,
3067 .stop
= netlink_seq_stop
,
3068 .show
= netlink_seq_show
,
3072 static int netlink_seq_open(struct inode
*inode
, struct file
*file
)
3074 return seq_open_net(inode
, file
, &netlink_seq_ops
,
3075 sizeof(struct nl_seq_iter
));
3078 static const struct file_operations netlink_seq_fops
= {
3079 .owner
= THIS_MODULE
,
3080 .open
= netlink_seq_open
,
3082 .llseek
= seq_lseek
,
3083 .release
= seq_release_net
,
3088 int netlink_register_notifier(struct notifier_block
*nb
)
3090 return atomic_notifier_chain_register(&netlink_chain
, nb
);
3092 EXPORT_SYMBOL(netlink_register_notifier
);
3094 int netlink_unregister_notifier(struct notifier_block
*nb
)
3096 return atomic_notifier_chain_unregister(&netlink_chain
, nb
);
3098 EXPORT_SYMBOL(netlink_unregister_notifier
);
3100 static const struct proto_ops netlink_ops
= {
3101 .family
= PF_NETLINK
,
3102 .owner
= THIS_MODULE
,
3103 .release
= netlink_release
,
3104 .bind
= netlink_bind
,
3105 .connect
= netlink_connect
,
3106 .socketpair
= sock_no_socketpair
,
3107 .accept
= sock_no_accept
,
3108 .getname
= netlink_getname
,
3109 .poll
= netlink_poll
,
3110 .ioctl
= sock_no_ioctl
,
3111 .listen
= sock_no_listen
,
3112 .shutdown
= sock_no_shutdown
,
3113 .setsockopt
= netlink_setsockopt
,
3114 .getsockopt
= netlink_getsockopt
,
3115 .sendmsg
= netlink_sendmsg
,
3116 .recvmsg
= netlink_recvmsg
,
3117 .mmap
= netlink_mmap
,
3118 .sendpage
= sock_no_sendpage
,
3121 static const struct net_proto_family netlink_family_ops
= {
3122 .family
= PF_NETLINK
,
3123 .create
= netlink_create
,
3124 .owner
= THIS_MODULE
, /* for consistency 8) */
3127 static int __net_init
netlink_net_init(struct net
*net
)
3129 #ifdef CONFIG_PROC_FS
3130 if (!proc_create("netlink", 0, net
->proc_net
, &netlink_seq_fops
))
3136 static void __net_exit
netlink_net_exit(struct net
*net
)
3138 #ifdef CONFIG_PROC_FS
3139 remove_proc_entry("netlink", net
->proc_net
);
3143 static void __init
netlink_add_usersock_entry(void)
3145 struct listeners
*listeners
;
3148 listeners
= kzalloc(sizeof(*listeners
) + NLGRPSZ(groups
), GFP_KERNEL
);
3150 panic("netlink_add_usersock_entry: Cannot allocate listeners\n");
3152 netlink_table_grab();
3154 nl_table
[NETLINK_USERSOCK
].groups
= groups
;
3155 rcu_assign_pointer(nl_table
[NETLINK_USERSOCK
].listeners
, listeners
);
3156 nl_table
[NETLINK_USERSOCK
].module
= THIS_MODULE
;
3157 nl_table
[NETLINK_USERSOCK
].registered
= 1;
3158 nl_table
[NETLINK_USERSOCK
].flags
= NL_CFG_F_NONROOT_SEND
;
3160 netlink_table_ungrab();
3163 static struct pernet_operations __net_initdata netlink_net_ops
= {
3164 .init
= netlink_net_init
,
3165 .exit
= netlink_net_exit
,
3168 static int __init
netlink_proto_init(void)
3171 unsigned long limit
;
3173 int err
= proto_register(&netlink_proto
, 0);
3178 BUILD_BUG_ON(sizeof(struct netlink_skb_parms
) > FIELD_SIZEOF(struct sk_buff
, cb
));
3180 nl_table
= kcalloc(MAX_LINKS
, sizeof(*nl_table
), GFP_KERNEL
);
3184 if (totalram_pages
>= (128 * 1024))
3185 limit
= totalram_pages
>> (21 - PAGE_SHIFT
);
3187 limit
= totalram_pages
>> (23 - PAGE_SHIFT
);
3189 order
= get_bitmask_order(limit
) - 1 + PAGE_SHIFT
;
3190 limit
= (1UL << order
) / sizeof(struct hlist_head
);
3191 order
= get_bitmask_order(min(limit
, (unsigned long)UINT_MAX
)) - 1;
3193 for (i
= 0; i
< MAX_LINKS
; i
++) {
3194 struct nl_portid_hash
*hash
= &nl_table
[i
].hash
;
3196 hash
->table
= nl_portid_hash_zalloc(1 * sizeof(*hash
->table
));
3199 nl_portid_hash_free(nl_table
[i
].hash
.table
,
3200 1 * sizeof(*hash
->table
));
3204 hash
->max_shift
= order
;
3207 hash
->rehash_time
= jiffies
;
3209 nl_table
[i
].compare
= netlink_compare
;
3212 INIT_LIST_HEAD(&netlink_tap_all
);
3214 netlink_add_usersock_entry();
3216 sock_register(&netlink_family_ops
);
3217 register_pernet_subsys(&netlink_net_ops
);
3218 /* The netlink device handler may be needed early. */
3223 panic("netlink_init: Cannot allocate nl_table\n");
3226 core_initcall(netlink_proto_init
);