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 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
;
158 EXPORT_SYMBOL_GPL(__netlink_remove_tap
);
160 int netlink_remove_tap(struct netlink_tap
*nt
)
164 ret
= __netlink_remove_tap(nt
);
169 EXPORT_SYMBOL_GPL(netlink_remove_tap
);
171 static bool netlink_filter_tap(const struct sk_buff
*skb
)
173 struct sock
*sk
= skb
->sk
;
176 /* We take the more conservative approach and
177 * whitelist socket protocols that may pass.
179 switch (sk
->sk_protocol
) {
181 case NETLINK_USERSOCK
:
182 case NETLINK_SOCK_DIAG
:
185 case NETLINK_FIB_LOOKUP
:
186 case NETLINK_NETFILTER
:
187 case NETLINK_GENERIC
:
195 static int __netlink_deliver_tap_skb(struct sk_buff
*skb
,
196 struct net_device
*dev
)
198 struct sk_buff
*nskb
;
199 struct sock
*sk
= skb
->sk
;
203 nskb
= skb_clone(skb
, GFP_ATOMIC
);
206 nskb
->protocol
= htons((u16
) sk
->sk_protocol
);
208 ret
= dev_queue_xmit(nskb
);
209 if (unlikely(ret
> 0))
210 ret
= net_xmit_errno(ret
);
217 static void __netlink_deliver_tap(struct sk_buff
*skb
)
220 struct netlink_tap
*tmp
;
222 if (!netlink_filter_tap(skb
))
225 list_for_each_entry_rcu(tmp
, &netlink_tap_all
, list
) {
226 ret
= __netlink_deliver_tap_skb(skb
, tmp
->dev
);
232 static void netlink_deliver_tap(struct sk_buff
*skb
)
236 if (unlikely(!list_empty(&netlink_tap_all
)))
237 __netlink_deliver_tap(skb
);
242 static void netlink_overrun(struct sock
*sk
)
244 struct netlink_sock
*nlk
= nlk_sk(sk
);
246 if (!(nlk
->flags
& NETLINK_RECV_NO_ENOBUFS
)) {
247 if (!test_and_set_bit(NETLINK_CONGESTED
, &nlk_sk(sk
)->state
)) {
248 sk
->sk_err
= ENOBUFS
;
249 sk
->sk_error_report(sk
);
252 atomic_inc(&sk
->sk_drops
);
255 static void netlink_rcv_wake(struct sock
*sk
)
257 struct netlink_sock
*nlk
= nlk_sk(sk
);
259 if (skb_queue_empty(&sk
->sk_receive_queue
))
260 clear_bit(NETLINK_CONGESTED
, &nlk
->state
);
261 if (!test_bit(NETLINK_CONGESTED
, &nlk
->state
))
262 wake_up_interruptible(&nlk
->wait
);
265 #ifdef CONFIG_NETLINK_MMAP
266 static bool netlink_skb_is_mmaped(const struct sk_buff
*skb
)
268 return NETLINK_CB(skb
).flags
& NETLINK_SKB_MMAPED
;
271 static bool netlink_rx_is_mmaped(struct sock
*sk
)
273 return nlk_sk(sk
)->rx_ring
.pg_vec
!= NULL
;
276 static bool netlink_tx_is_mmaped(struct sock
*sk
)
278 return nlk_sk(sk
)->tx_ring
.pg_vec
!= NULL
;
281 static __pure
struct page
*pgvec_to_page(const void *addr
)
283 if (is_vmalloc_addr(addr
))
284 return vmalloc_to_page(addr
);
286 return virt_to_page(addr
);
289 static void free_pg_vec(void **pg_vec
, unsigned int order
, unsigned int len
)
293 for (i
= 0; i
< len
; i
++) {
294 if (pg_vec
[i
] != NULL
) {
295 if (is_vmalloc_addr(pg_vec
[i
]))
298 free_pages((unsigned long)pg_vec
[i
], order
);
304 static void *alloc_one_pg_vec_page(unsigned long order
)
307 gfp_t gfp_flags
= GFP_KERNEL
| __GFP_COMP
| __GFP_ZERO
|
308 __GFP_NOWARN
| __GFP_NORETRY
;
310 buffer
= (void *)__get_free_pages(gfp_flags
, order
);
314 buffer
= vzalloc((1 << order
) * PAGE_SIZE
);
318 gfp_flags
&= ~__GFP_NORETRY
;
319 return (void *)__get_free_pages(gfp_flags
, order
);
322 static void **alloc_pg_vec(struct netlink_sock
*nlk
,
323 struct nl_mmap_req
*req
, unsigned int order
)
325 unsigned int block_nr
= req
->nm_block_nr
;
329 pg_vec
= kcalloc(block_nr
, sizeof(void *), GFP_KERNEL
);
333 for (i
= 0; i
< block_nr
; i
++) {
334 pg_vec
[i
] = alloc_one_pg_vec_page(order
);
335 if (pg_vec
[i
] == NULL
)
341 free_pg_vec(pg_vec
, order
, block_nr
);
345 static int netlink_set_ring(struct sock
*sk
, struct nl_mmap_req
*req
,
346 bool closing
, bool tx_ring
)
348 struct netlink_sock
*nlk
= nlk_sk(sk
);
349 struct netlink_ring
*ring
;
350 struct sk_buff_head
*queue
;
351 void **pg_vec
= NULL
;
352 unsigned int order
= 0;
355 ring
= tx_ring
? &nlk
->tx_ring
: &nlk
->rx_ring
;
356 queue
= tx_ring
? &sk
->sk_write_queue
: &sk
->sk_receive_queue
;
359 if (atomic_read(&nlk
->mapped
))
361 if (atomic_read(&ring
->pending
))
365 if (req
->nm_block_nr
) {
366 if (ring
->pg_vec
!= NULL
)
369 if ((int)req
->nm_block_size
<= 0)
371 if (!IS_ALIGNED(req
->nm_block_size
, PAGE_SIZE
))
373 if (req
->nm_frame_size
< NL_MMAP_HDRLEN
)
375 if (!IS_ALIGNED(req
->nm_frame_size
, NL_MMAP_MSG_ALIGNMENT
))
378 ring
->frames_per_block
= req
->nm_block_size
/
380 if (ring
->frames_per_block
== 0)
382 if (ring
->frames_per_block
* req
->nm_block_nr
!=
386 order
= get_order(req
->nm_block_size
);
387 pg_vec
= alloc_pg_vec(nlk
, req
, order
);
391 if (req
->nm_frame_nr
)
396 mutex_lock(&nlk
->pg_vec_lock
);
397 if (closing
|| atomic_read(&nlk
->mapped
) == 0) {
399 spin_lock_bh(&queue
->lock
);
401 ring
->frame_max
= req
->nm_frame_nr
- 1;
403 ring
->frame_size
= req
->nm_frame_size
;
404 ring
->pg_vec_pages
= req
->nm_block_size
/ PAGE_SIZE
;
406 swap(ring
->pg_vec_len
, req
->nm_block_nr
);
407 swap(ring
->pg_vec_order
, order
);
408 swap(ring
->pg_vec
, pg_vec
);
410 __skb_queue_purge(queue
);
411 spin_unlock_bh(&queue
->lock
);
413 WARN_ON(atomic_read(&nlk
->mapped
));
415 mutex_unlock(&nlk
->pg_vec_lock
);
418 free_pg_vec(pg_vec
, order
, req
->nm_block_nr
);
422 static void netlink_mm_open(struct vm_area_struct
*vma
)
424 struct file
*file
= vma
->vm_file
;
425 struct socket
*sock
= file
->private_data
;
426 struct sock
*sk
= sock
->sk
;
429 atomic_inc(&nlk_sk(sk
)->mapped
);
432 static void netlink_mm_close(struct vm_area_struct
*vma
)
434 struct file
*file
= vma
->vm_file
;
435 struct socket
*sock
= file
->private_data
;
436 struct sock
*sk
= sock
->sk
;
439 atomic_dec(&nlk_sk(sk
)->mapped
);
442 static const struct vm_operations_struct netlink_mmap_ops
= {
443 .open
= netlink_mm_open
,
444 .close
= netlink_mm_close
,
447 static int netlink_mmap(struct file
*file
, struct socket
*sock
,
448 struct vm_area_struct
*vma
)
450 struct sock
*sk
= sock
->sk
;
451 struct netlink_sock
*nlk
= nlk_sk(sk
);
452 struct netlink_ring
*ring
;
453 unsigned long start
, size
, expected
;
460 mutex_lock(&nlk
->pg_vec_lock
);
463 for (ring
= &nlk
->rx_ring
; ring
<= &nlk
->tx_ring
; ring
++) {
464 if (ring
->pg_vec
== NULL
)
466 expected
+= ring
->pg_vec_len
* ring
->pg_vec_pages
* PAGE_SIZE
;
472 size
= vma
->vm_end
- vma
->vm_start
;
473 if (size
!= expected
)
476 start
= vma
->vm_start
;
477 for (ring
= &nlk
->rx_ring
; ring
<= &nlk
->tx_ring
; ring
++) {
478 if (ring
->pg_vec
== NULL
)
481 for (i
= 0; i
< ring
->pg_vec_len
; i
++) {
483 void *kaddr
= ring
->pg_vec
[i
];
486 for (pg_num
= 0; pg_num
< ring
->pg_vec_pages
; pg_num
++) {
487 page
= pgvec_to_page(kaddr
);
488 err
= vm_insert_page(vma
, start
, page
);
497 atomic_inc(&nlk
->mapped
);
498 vma
->vm_ops
= &netlink_mmap_ops
;
501 mutex_unlock(&nlk
->pg_vec_lock
);
505 static void netlink_frame_flush_dcache(const struct nl_mmap_hdr
*hdr
)
507 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
508 struct page
*p_start
, *p_end
;
510 /* First page is flushed through netlink_{get,set}_status */
511 p_start
= pgvec_to_page(hdr
+ PAGE_SIZE
);
512 p_end
= pgvec_to_page((void *)hdr
+ NL_MMAP_HDRLEN
+ hdr
->nm_len
- 1);
513 while (p_start
<= p_end
) {
514 flush_dcache_page(p_start
);
520 static enum nl_mmap_status
netlink_get_status(const struct nl_mmap_hdr
*hdr
)
523 flush_dcache_page(pgvec_to_page(hdr
));
524 return hdr
->nm_status
;
527 static void netlink_set_status(struct nl_mmap_hdr
*hdr
,
528 enum nl_mmap_status status
)
530 hdr
->nm_status
= status
;
531 flush_dcache_page(pgvec_to_page(hdr
));
535 static struct nl_mmap_hdr
*
536 __netlink_lookup_frame(const struct netlink_ring
*ring
, unsigned int pos
)
538 unsigned int pg_vec_pos
, frame_off
;
540 pg_vec_pos
= pos
/ ring
->frames_per_block
;
541 frame_off
= pos
% ring
->frames_per_block
;
543 return ring
->pg_vec
[pg_vec_pos
] + (frame_off
* ring
->frame_size
);
546 static struct nl_mmap_hdr
*
547 netlink_lookup_frame(const struct netlink_ring
*ring
, unsigned int pos
,
548 enum nl_mmap_status status
)
550 struct nl_mmap_hdr
*hdr
;
552 hdr
= __netlink_lookup_frame(ring
, pos
);
553 if (netlink_get_status(hdr
) != status
)
559 static struct nl_mmap_hdr
*
560 netlink_current_frame(const struct netlink_ring
*ring
,
561 enum nl_mmap_status status
)
563 return netlink_lookup_frame(ring
, ring
->head
, status
);
566 static struct nl_mmap_hdr
*
567 netlink_previous_frame(const struct netlink_ring
*ring
,
568 enum nl_mmap_status status
)
572 prev
= ring
->head
? ring
->head
- 1 : ring
->frame_max
;
573 return netlink_lookup_frame(ring
, prev
, status
);
576 static void netlink_increment_head(struct netlink_ring
*ring
)
578 ring
->head
= ring
->head
!= ring
->frame_max
? ring
->head
+ 1 : 0;
581 static void netlink_forward_ring(struct netlink_ring
*ring
)
583 unsigned int head
= ring
->head
, pos
= head
;
584 const struct nl_mmap_hdr
*hdr
;
587 hdr
= __netlink_lookup_frame(ring
, pos
);
588 if (hdr
->nm_status
== NL_MMAP_STATUS_UNUSED
)
590 if (hdr
->nm_status
!= NL_MMAP_STATUS_SKIP
)
592 netlink_increment_head(ring
);
593 } while (ring
->head
!= head
);
596 static bool netlink_dump_space(struct netlink_sock
*nlk
)
598 struct netlink_ring
*ring
= &nlk
->rx_ring
;
599 struct nl_mmap_hdr
*hdr
;
602 hdr
= netlink_current_frame(ring
, NL_MMAP_STATUS_UNUSED
);
606 n
= ring
->head
+ ring
->frame_max
/ 2;
607 if (n
> ring
->frame_max
)
608 n
-= ring
->frame_max
;
610 hdr
= __netlink_lookup_frame(ring
, n
);
612 return hdr
->nm_status
== NL_MMAP_STATUS_UNUSED
;
615 static unsigned int netlink_poll(struct file
*file
, struct socket
*sock
,
618 struct sock
*sk
= sock
->sk
;
619 struct netlink_sock
*nlk
= nlk_sk(sk
);
623 if (nlk
->rx_ring
.pg_vec
!= NULL
) {
624 /* Memory mapped sockets don't call recvmsg(), so flow control
625 * for dumps is performed here. A dump is allowed to continue
626 * if at least half the ring is unused.
628 while (nlk
->cb_running
&& netlink_dump_space(nlk
)) {
629 err
= netlink_dump(sk
);
632 sk
->sk_error_report(sk
);
636 netlink_rcv_wake(sk
);
639 mask
= datagram_poll(file
, sock
, wait
);
641 spin_lock_bh(&sk
->sk_receive_queue
.lock
);
642 if (nlk
->rx_ring
.pg_vec
) {
643 netlink_forward_ring(&nlk
->rx_ring
);
644 if (!netlink_previous_frame(&nlk
->rx_ring
, NL_MMAP_STATUS_UNUSED
))
645 mask
|= POLLIN
| POLLRDNORM
;
647 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
649 spin_lock_bh(&sk
->sk_write_queue
.lock
);
650 if (nlk
->tx_ring
.pg_vec
) {
651 if (netlink_current_frame(&nlk
->tx_ring
, NL_MMAP_STATUS_UNUSED
))
652 mask
|= POLLOUT
| POLLWRNORM
;
654 spin_unlock_bh(&sk
->sk_write_queue
.lock
);
659 static struct nl_mmap_hdr
*netlink_mmap_hdr(struct sk_buff
*skb
)
661 return (struct nl_mmap_hdr
*)(skb
->head
- NL_MMAP_HDRLEN
);
664 static void netlink_ring_setup_skb(struct sk_buff
*skb
, struct sock
*sk
,
665 struct netlink_ring
*ring
,
666 struct nl_mmap_hdr
*hdr
)
671 size
= ring
->frame_size
- NL_MMAP_HDRLEN
;
672 data
= (void *)hdr
+ NL_MMAP_HDRLEN
;
676 skb_reset_tail_pointer(skb
);
677 skb
->end
= skb
->tail
+ size
;
680 skb
->destructor
= netlink_skb_destructor
;
681 NETLINK_CB(skb
).flags
|= NETLINK_SKB_MMAPED
;
682 NETLINK_CB(skb
).sk
= sk
;
685 static int netlink_mmap_sendmsg(struct sock
*sk
, struct msghdr
*msg
,
686 u32 dst_portid
, u32 dst_group
,
687 struct sock_iocb
*siocb
)
689 struct netlink_sock
*nlk
= nlk_sk(sk
);
690 struct netlink_ring
*ring
;
691 struct nl_mmap_hdr
*hdr
;
695 int err
= 0, len
= 0;
697 /* Netlink messages are validated by the receiver before processing.
698 * In order to avoid userspace changing the contents of the message
699 * after validation, the socket and the ring may only be used by a
700 * single process, otherwise we fall back to copying.
702 if (atomic_long_read(&sk
->sk_socket
->file
->f_count
) > 2 ||
703 atomic_read(&nlk
->mapped
) > 1)
706 mutex_lock(&nlk
->pg_vec_lock
);
708 ring
= &nlk
->tx_ring
;
709 maxlen
= ring
->frame_size
- NL_MMAP_HDRLEN
;
712 hdr
= netlink_current_frame(ring
, NL_MMAP_STATUS_VALID
);
714 if (!(msg
->msg_flags
& MSG_DONTWAIT
) &&
715 atomic_read(&nlk
->tx_ring
.pending
))
719 if (hdr
->nm_len
> maxlen
) {
724 netlink_frame_flush_dcache(hdr
);
726 if (likely(dst_portid
== 0 && dst_group
== 0 && excl
)) {
727 skb
= alloc_skb_head(GFP_KERNEL
);
733 netlink_ring_setup_skb(skb
, sk
, ring
, hdr
);
734 NETLINK_CB(skb
).flags
|= NETLINK_SKB_TX
;
735 __skb_put(skb
, hdr
->nm_len
);
736 netlink_set_status(hdr
, NL_MMAP_STATUS_RESERVED
);
737 atomic_inc(&ring
->pending
);
739 skb
= alloc_skb(hdr
->nm_len
, GFP_KERNEL
);
744 __skb_put(skb
, hdr
->nm_len
);
745 memcpy(skb
->data
, (void *)hdr
+ NL_MMAP_HDRLEN
, hdr
->nm_len
);
746 netlink_set_status(hdr
, NL_MMAP_STATUS_UNUSED
);
749 netlink_increment_head(ring
);
751 NETLINK_CB(skb
).portid
= nlk
->portid
;
752 NETLINK_CB(skb
).dst_group
= dst_group
;
753 NETLINK_CB(skb
).creds
= siocb
->scm
->creds
;
755 err
= security_netlink_send(sk
, skb
);
761 if (unlikely(dst_group
)) {
762 atomic_inc(&skb
->users
);
763 netlink_broadcast(sk
, skb
, dst_portid
, dst_group
,
766 err
= netlink_unicast(sk
, skb
, dst_portid
,
767 msg
->msg_flags
& MSG_DONTWAIT
);
772 } while (hdr
!= NULL
||
773 (!(msg
->msg_flags
& MSG_DONTWAIT
) &&
774 atomic_read(&nlk
->tx_ring
.pending
)));
779 mutex_unlock(&nlk
->pg_vec_lock
);
783 static void netlink_queue_mmaped_skb(struct sock
*sk
, struct sk_buff
*skb
)
785 struct nl_mmap_hdr
*hdr
;
787 hdr
= netlink_mmap_hdr(skb
);
788 hdr
->nm_len
= skb
->len
;
789 hdr
->nm_group
= NETLINK_CB(skb
).dst_group
;
790 hdr
->nm_pid
= NETLINK_CB(skb
).creds
.pid
;
791 hdr
->nm_uid
= from_kuid(sk_user_ns(sk
), NETLINK_CB(skb
).creds
.uid
);
792 hdr
->nm_gid
= from_kgid(sk_user_ns(sk
), NETLINK_CB(skb
).creds
.gid
);
793 netlink_frame_flush_dcache(hdr
);
794 netlink_set_status(hdr
, NL_MMAP_STATUS_VALID
);
796 NETLINK_CB(skb
).flags
|= NETLINK_SKB_DELIVERED
;
800 static void netlink_ring_set_copied(struct sock
*sk
, struct sk_buff
*skb
)
802 struct netlink_sock
*nlk
= nlk_sk(sk
);
803 struct netlink_ring
*ring
= &nlk
->rx_ring
;
804 struct nl_mmap_hdr
*hdr
;
806 spin_lock_bh(&sk
->sk_receive_queue
.lock
);
807 hdr
= netlink_current_frame(ring
, NL_MMAP_STATUS_UNUSED
);
809 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
814 netlink_increment_head(ring
);
815 __skb_queue_tail(&sk
->sk_receive_queue
, skb
);
816 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
818 hdr
->nm_len
= skb
->len
;
819 hdr
->nm_group
= NETLINK_CB(skb
).dst_group
;
820 hdr
->nm_pid
= NETLINK_CB(skb
).creds
.pid
;
821 hdr
->nm_uid
= from_kuid(sk_user_ns(sk
), NETLINK_CB(skb
).creds
.uid
);
822 hdr
->nm_gid
= from_kgid(sk_user_ns(sk
), NETLINK_CB(skb
).creds
.gid
);
823 netlink_set_status(hdr
, NL_MMAP_STATUS_COPY
);
826 #else /* CONFIG_NETLINK_MMAP */
827 #define netlink_skb_is_mmaped(skb) false
828 #define netlink_rx_is_mmaped(sk) false
829 #define netlink_tx_is_mmaped(sk) false
830 #define netlink_mmap sock_no_mmap
831 #define netlink_poll datagram_poll
832 #define netlink_mmap_sendmsg(sk, msg, dst_portid, dst_group, siocb) 0
833 #endif /* CONFIG_NETLINK_MMAP */
835 static void netlink_skb_destructor(struct sk_buff
*skb
)
837 #ifdef CONFIG_NETLINK_MMAP
838 struct nl_mmap_hdr
*hdr
;
839 struct netlink_ring
*ring
;
842 /* If a packet from the kernel to userspace was freed because of an
843 * error without being delivered to userspace, the kernel must reset
844 * the status. In the direction userspace to kernel, the status is
845 * always reset here after the packet was processed and freed.
847 if (netlink_skb_is_mmaped(skb
)) {
848 hdr
= netlink_mmap_hdr(skb
);
849 sk
= NETLINK_CB(skb
).sk
;
851 if (NETLINK_CB(skb
).flags
& NETLINK_SKB_TX
) {
852 netlink_set_status(hdr
, NL_MMAP_STATUS_UNUSED
);
853 ring
= &nlk_sk(sk
)->tx_ring
;
855 if (!(NETLINK_CB(skb
).flags
& NETLINK_SKB_DELIVERED
)) {
857 netlink_set_status(hdr
, NL_MMAP_STATUS_VALID
);
859 ring
= &nlk_sk(sk
)->rx_ring
;
862 WARN_ON(atomic_read(&ring
->pending
) == 0);
863 atomic_dec(&ring
->pending
);
869 if (is_vmalloc_addr(skb
->head
)) {
871 !atomic_dec_return(&(skb_shinfo(skb
)->dataref
)))
880 static void netlink_skb_set_owner_r(struct sk_buff
*skb
, struct sock
*sk
)
882 WARN_ON(skb
->sk
!= NULL
);
884 skb
->destructor
= netlink_skb_destructor
;
885 atomic_add(skb
->truesize
, &sk
->sk_rmem_alloc
);
886 sk_mem_charge(sk
, skb
->truesize
);
889 static void netlink_sock_destruct(struct sock
*sk
)
891 struct netlink_sock
*nlk
= nlk_sk(sk
);
893 if (nlk
->cb_running
) {
895 nlk
->cb
.done(&nlk
->cb
);
897 module_put(nlk
->cb
.module
);
898 kfree_skb(nlk
->cb
.skb
);
901 skb_queue_purge(&sk
->sk_receive_queue
);
902 #ifdef CONFIG_NETLINK_MMAP
904 struct nl_mmap_req req
;
906 memset(&req
, 0, sizeof(req
));
907 if (nlk
->rx_ring
.pg_vec
)
908 netlink_set_ring(sk
, &req
, true, false);
909 memset(&req
, 0, sizeof(req
));
910 if (nlk
->tx_ring
.pg_vec
)
911 netlink_set_ring(sk
, &req
, true, true);
913 #endif /* CONFIG_NETLINK_MMAP */
915 if (!sock_flag(sk
, SOCK_DEAD
)) {
916 printk(KERN_ERR
"Freeing alive netlink socket %p\n", sk
);
920 WARN_ON(atomic_read(&sk
->sk_rmem_alloc
));
921 WARN_ON(atomic_read(&sk
->sk_wmem_alloc
));
922 WARN_ON(nlk_sk(sk
)->groups
);
925 /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on
926 * SMP. Look, when several writers sleep and reader wakes them up, all but one
927 * immediately hit write lock and grab all the cpus. Exclusive sleep solves
928 * this, _but_ remember, it adds useless work on UP machines.
931 void netlink_table_grab(void)
932 __acquires(nl_table_lock
)
936 write_lock_irq(&nl_table_lock
);
938 if (atomic_read(&nl_table_users
)) {
939 DECLARE_WAITQUEUE(wait
, current
);
941 add_wait_queue_exclusive(&nl_table_wait
, &wait
);
943 set_current_state(TASK_UNINTERRUPTIBLE
);
944 if (atomic_read(&nl_table_users
) == 0)
946 write_unlock_irq(&nl_table_lock
);
948 write_lock_irq(&nl_table_lock
);
951 __set_current_state(TASK_RUNNING
);
952 remove_wait_queue(&nl_table_wait
, &wait
);
956 void netlink_table_ungrab(void)
957 __releases(nl_table_lock
)
959 write_unlock_irq(&nl_table_lock
);
960 wake_up(&nl_table_wait
);
964 netlink_lock_table(void)
966 /* read_lock() synchronizes us to netlink_table_grab */
968 read_lock(&nl_table_lock
);
969 atomic_inc(&nl_table_users
);
970 read_unlock(&nl_table_lock
);
974 netlink_unlock_table(void)
976 if (atomic_dec_and_test(&nl_table_users
))
977 wake_up(&nl_table_wait
);
980 static bool netlink_compare(struct net
*net
, struct sock
*sk
)
982 return net_eq(sock_net(sk
), net
);
985 static struct sock
*netlink_lookup(struct net
*net
, int protocol
, u32 portid
)
987 struct netlink_table
*table
= &nl_table
[protocol
];
988 struct nl_portid_hash
*hash
= &table
->hash
;
989 struct hlist_head
*head
;
992 read_lock(&nl_table_lock
);
993 head
= nl_portid_hashfn(hash
, portid
);
994 sk_for_each(sk
, head
) {
995 if (table
->compare(net
, sk
) &&
996 (nlk_sk(sk
)->portid
== portid
)) {
1003 read_unlock(&nl_table_lock
);
1007 static struct hlist_head
*nl_portid_hash_zalloc(size_t size
)
1009 if (size
<= PAGE_SIZE
)
1010 return kzalloc(size
, GFP_ATOMIC
);
1012 return (struct hlist_head
*)
1013 __get_free_pages(GFP_ATOMIC
| __GFP_ZERO
,
1017 static void nl_portid_hash_free(struct hlist_head
*table
, size_t size
)
1019 if (size
<= PAGE_SIZE
)
1022 free_pages((unsigned long)table
, get_order(size
));
1025 static int nl_portid_hash_rehash(struct nl_portid_hash
*hash
, int grow
)
1027 unsigned int omask
, mask
, shift
;
1029 struct hlist_head
*otable
, *table
;
1032 omask
= mask
= hash
->mask
;
1033 osize
= size
= (mask
+ 1) * sizeof(*table
);
1034 shift
= hash
->shift
;
1037 if (++shift
> hash
->max_shift
)
1039 mask
= mask
* 2 + 1;
1043 table
= nl_portid_hash_zalloc(size
);
1047 otable
= hash
->table
;
1048 hash
->table
= table
;
1050 hash
->shift
= shift
;
1051 get_random_bytes(&hash
->rnd
, sizeof(hash
->rnd
));
1053 for (i
= 0; i
<= omask
; i
++) {
1055 struct hlist_node
*tmp
;
1057 sk_for_each_safe(sk
, tmp
, &otable
[i
])
1058 __sk_add_node(sk
, nl_portid_hashfn(hash
, nlk_sk(sk
)->portid
));
1061 nl_portid_hash_free(otable
, osize
);
1062 hash
->rehash_time
= jiffies
+ 10 * 60 * HZ
;
1066 static inline int nl_portid_hash_dilute(struct nl_portid_hash
*hash
, int len
)
1068 int avg
= hash
->entries
>> hash
->shift
;
1070 if (unlikely(avg
> 1) && nl_portid_hash_rehash(hash
, 1))
1073 if (unlikely(len
> avg
) && time_after(jiffies
, hash
->rehash_time
)) {
1074 nl_portid_hash_rehash(hash
, 0);
1081 static const struct proto_ops netlink_ops
;
1084 netlink_update_listeners(struct sock
*sk
)
1086 struct netlink_table
*tbl
= &nl_table
[sk
->sk_protocol
];
1089 struct listeners
*listeners
;
1091 listeners
= nl_deref_protected(tbl
->listeners
);
1095 for (i
= 0; i
< NLGRPLONGS(tbl
->groups
); i
++) {
1097 sk_for_each_bound(sk
, &tbl
->mc_list
) {
1098 if (i
< NLGRPLONGS(nlk_sk(sk
)->ngroups
))
1099 mask
|= nlk_sk(sk
)->groups
[i
];
1101 listeners
->masks
[i
] = mask
;
1103 /* this function is only called with the netlink table "grabbed", which
1104 * makes sure updates are visible before bind or setsockopt return. */
1107 static int netlink_insert(struct sock
*sk
, struct net
*net
, u32 portid
)
1109 struct netlink_table
*table
= &nl_table
[sk
->sk_protocol
];
1110 struct nl_portid_hash
*hash
= &table
->hash
;
1111 struct hlist_head
*head
;
1112 int err
= -EADDRINUSE
;
1116 netlink_table_grab();
1117 head
= nl_portid_hashfn(hash
, portid
);
1119 sk_for_each(osk
, head
) {
1120 if (table
->compare(net
, osk
) &&
1121 (nlk_sk(osk
)->portid
== portid
))
1129 if (nlk_sk(sk
)->portid
)
1133 if (BITS_PER_LONG
> 32 && unlikely(hash
->entries
>= UINT_MAX
))
1136 if (len
&& nl_portid_hash_dilute(hash
, len
))
1137 head
= nl_portid_hashfn(hash
, portid
);
1139 nlk_sk(sk
)->portid
= portid
;
1140 sk_add_node(sk
, head
);
1144 netlink_table_ungrab();
1148 static void netlink_remove(struct sock
*sk
)
1150 netlink_table_grab();
1151 if (sk_del_node_init(sk
))
1152 nl_table
[sk
->sk_protocol
].hash
.entries
--;
1153 if (nlk_sk(sk
)->subscriptions
)
1154 __sk_del_bind_node(sk
);
1155 netlink_table_ungrab();
1158 static struct proto netlink_proto
= {
1160 .owner
= THIS_MODULE
,
1161 .obj_size
= sizeof(struct netlink_sock
),
1164 static int __netlink_create(struct net
*net
, struct socket
*sock
,
1165 struct mutex
*cb_mutex
, int protocol
)
1168 struct netlink_sock
*nlk
;
1170 sock
->ops
= &netlink_ops
;
1172 sk
= sk_alloc(net
, PF_NETLINK
, GFP_KERNEL
, &netlink_proto
);
1176 sock_init_data(sock
, sk
);
1180 nlk
->cb_mutex
= cb_mutex
;
1182 nlk
->cb_mutex
= &nlk
->cb_def_mutex
;
1183 mutex_init(nlk
->cb_mutex
);
1185 init_waitqueue_head(&nlk
->wait
);
1186 #ifdef CONFIG_NETLINK_MMAP
1187 mutex_init(&nlk
->pg_vec_lock
);
1190 sk
->sk_destruct
= netlink_sock_destruct
;
1191 sk
->sk_protocol
= protocol
;
1195 static int netlink_create(struct net
*net
, struct socket
*sock
, int protocol
,
1198 struct module
*module
= NULL
;
1199 struct mutex
*cb_mutex
;
1200 struct netlink_sock
*nlk
;
1201 void (*bind
)(int group
);
1204 sock
->state
= SS_UNCONNECTED
;
1206 if (sock
->type
!= SOCK_RAW
&& sock
->type
!= SOCK_DGRAM
)
1207 return -ESOCKTNOSUPPORT
;
1209 if (protocol
< 0 || protocol
>= MAX_LINKS
)
1210 return -EPROTONOSUPPORT
;
1212 netlink_lock_table();
1213 #ifdef CONFIG_MODULES
1214 if (!nl_table
[protocol
].registered
) {
1215 netlink_unlock_table();
1216 request_module("net-pf-%d-proto-%d", PF_NETLINK
, protocol
);
1217 netlink_lock_table();
1220 if (nl_table
[protocol
].registered
&&
1221 try_module_get(nl_table
[protocol
].module
))
1222 module
= nl_table
[protocol
].module
;
1224 err
= -EPROTONOSUPPORT
;
1225 cb_mutex
= nl_table
[protocol
].cb_mutex
;
1226 bind
= nl_table
[protocol
].bind
;
1227 netlink_unlock_table();
1232 err
= __netlink_create(net
, sock
, cb_mutex
, protocol
);
1237 sock_prot_inuse_add(net
, &netlink_proto
, 1);
1240 nlk
= nlk_sk(sock
->sk
);
1241 nlk
->module
= module
;
1242 nlk
->netlink_bind
= bind
;
1251 static int netlink_release(struct socket
*sock
)
1253 struct sock
*sk
= sock
->sk
;
1254 struct netlink_sock
*nlk
;
1264 * OK. Socket is unlinked, any packets that arrive now
1269 wake_up_interruptible_all(&nlk
->wait
);
1271 skb_queue_purge(&sk
->sk_write_queue
);
1274 struct netlink_notify n
= {
1275 .net
= sock_net(sk
),
1276 .protocol
= sk
->sk_protocol
,
1277 .portid
= nlk
->portid
,
1279 atomic_notifier_call_chain(&netlink_chain
,
1280 NETLINK_URELEASE
, &n
);
1283 module_put(nlk
->module
);
1285 netlink_table_grab();
1286 if (netlink_is_kernel(sk
)) {
1287 BUG_ON(nl_table
[sk
->sk_protocol
].registered
== 0);
1288 if (--nl_table
[sk
->sk_protocol
].registered
== 0) {
1289 struct listeners
*old
;
1291 old
= nl_deref_protected(nl_table
[sk
->sk_protocol
].listeners
);
1292 RCU_INIT_POINTER(nl_table
[sk
->sk_protocol
].listeners
, NULL
);
1293 kfree_rcu(old
, rcu
);
1294 nl_table
[sk
->sk_protocol
].module
= NULL
;
1295 nl_table
[sk
->sk_protocol
].bind
= NULL
;
1296 nl_table
[sk
->sk_protocol
].flags
= 0;
1297 nl_table
[sk
->sk_protocol
].registered
= 0;
1299 } else if (nlk
->subscriptions
) {
1300 netlink_update_listeners(sk
);
1302 netlink_table_ungrab();
1308 sock_prot_inuse_add(sock_net(sk
), &netlink_proto
, -1);
1314 static int netlink_autobind(struct socket
*sock
)
1316 struct sock
*sk
= sock
->sk
;
1317 struct net
*net
= sock_net(sk
);
1318 struct netlink_table
*table
= &nl_table
[sk
->sk_protocol
];
1319 struct nl_portid_hash
*hash
= &table
->hash
;
1320 struct hlist_head
*head
;
1322 s32 portid
= task_tgid_vnr(current
);
1324 static s32 rover
= -4097;
1328 netlink_table_grab();
1329 head
= nl_portid_hashfn(hash
, portid
);
1330 sk_for_each(osk
, head
) {
1331 if (!table
->compare(net
, osk
))
1333 if (nlk_sk(osk
)->portid
== portid
) {
1334 /* Bind collision, search negative portid values. */
1338 netlink_table_ungrab();
1342 netlink_table_ungrab();
1344 err
= netlink_insert(sk
, net
, portid
);
1345 if (err
== -EADDRINUSE
)
1348 /* If 2 threads race to autobind, that is fine. */
1356 * __netlink_ns_capable - General netlink message capability test
1357 * @nsp: NETLINK_CB of the socket buffer holding a netlink command from userspace.
1358 * @user_ns: The user namespace of the capability to use
1359 * @cap: The capability to use
1361 * Test to see if the opener of the socket we received the message
1362 * from had when the netlink socket was created and the sender of the
1363 * message has has the capability @cap in the user namespace @user_ns.
1365 bool __netlink_ns_capable(const struct netlink_skb_parms
*nsp
,
1366 struct user_namespace
*user_ns
, int cap
)
1368 return ((nsp
->flags
& NETLINK_SKB_DST
) ||
1369 file_ns_capable(nsp
->sk
->sk_socket
->file
, user_ns
, cap
)) &&
1370 ns_capable(user_ns
, cap
);
1372 EXPORT_SYMBOL(__netlink_ns_capable
);
1375 * netlink_ns_capable - General netlink message capability test
1376 * @skb: socket buffer holding a netlink command from userspace
1377 * @user_ns: The user namespace of the capability to use
1378 * @cap: The capability to use
1380 * Test to see if the opener of the socket we received the message
1381 * from had when the netlink socket was created and the sender of the
1382 * message has has the capability @cap in the user namespace @user_ns.
1384 bool netlink_ns_capable(const struct sk_buff
*skb
,
1385 struct user_namespace
*user_ns
, int cap
)
1387 return __netlink_ns_capable(&NETLINK_CB(skb
), user_ns
, cap
);
1389 EXPORT_SYMBOL(netlink_ns_capable
);
1392 * netlink_capable - Netlink global message capability test
1393 * @skb: socket buffer holding a netlink command from userspace
1394 * @cap: The capability to use
1396 * Test to see if the opener of the socket we received the message
1397 * from had when the netlink socket was created and the sender of the
1398 * message has has the capability @cap in all user namespaces.
1400 bool netlink_capable(const struct sk_buff
*skb
, int cap
)
1402 return netlink_ns_capable(skb
, &init_user_ns
, cap
);
1404 EXPORT_SYMBOL(netlink_capable
);
1407 * netlink_net_capable - Netlink network namespace message capability test
1408 * @skb: socket buffer holding a netlink command from userspace
1409 * @cap: The capability to use
1411 * Test to see if the opener of the socket we received the message
1412 * from had when the netlink socket was created and the sender of the
1413 * message has has the capability @cap over the network namespace of
1414 * the socket we received the message from.
1416 bool netlink_net_capable(const struct sk_buff
*skb
, int cap
)
1418 return netlink_ns_capable(skb
, sock_net(skb
->sk
)->user_ns
, cap
);
1420 EXPORT_SYMBOL(netlink_net_capable
);
1422 static inline int netlink_allowed(const struct socket
*sock
, unsigned int flag
)
1424 return (nl_table
[sock
->sk
->sk_protocol
].flags
& flag
) ||
1425 ns_capable(sock_net(sock
->sk
)->user_ns
, CAP_NET_ADMIN
);
1429 netlink_update_subscriptions(struct sock
*sk
, unsigned int subscriptions
)
1431 struct netlink_sock
*nlk
= nlk_sk(sk
);
1433 if (nlk
->subscriptions
&& !subscriptions
)
1434 __sk_del_bind_node(sk
);
1435 else if (!nlk
->subscriptions
&& subscriptions
)
1436 sk_add_bind_node(sk
, &nl_table
[sk
->sk_protocol
].mc_list
);
1437 nlk
->subscriptions
= subscriptions
;
1440 static int netlink_realloc_groups(struct sock
*sk
)
1442 struct netlink_sock
*nlk
= nlk_sk(sk
);
1443 unsigned int groups
;
1444 unsigned long *new_groups
;
1447 netlink_table_grab();
1449 groups
= nl_table
[sk
->sk_protocol
].groups
;
1450 if (!nl_table
[sk
->sk_protocol
].registered
) {
1455 if (nlk
->ngroups
>= groups
)
1458 new_groups
= krealloc(nlk
->groups
, NLGRPSZ(groups
), GFP_ATOMIC
);
1459 if (new_groups
== NULL
) {
1463 memset((char *)new_groups
+ NLGRPSZ(nlk
->ngroups
), 0,
1464 NLGRPSZ(groups
) - NLGRPSZ(nlk
->ngroups
));
1466 nlk
->groups
= new_groups
;
1467 nlk
->ngroups
= groups
;
1469 netlink_table_ungrab();
1473 static int netlink_bind(struct socket
*sock
, struct sockaddr
*addr
,
1476 struct sock
*sk
= sock
->sk
;
1477 struct net
*net
= sock_net(sk
);
1478 struct netlink_sock
*nlk
= nlk_sk(sk
);
1479 struct sockaddr_nl
*nladdr
= (struct sockaddr_nl
*)addr
;
1482 if (addr_len
< sizeof(struct sockaddr_nl
))
1485 if (nladdr
->nl_family
!= AF_NETLINK
)
1488 /* Only superuser is allowed to listen multicasts */
1489 if (nladdr
->nl_groups
) {
1490 if (!netlink_allowed(sock
, NL_CFG_F_NONROOT_RECV
))
1492 err
= netlink_realloc_groups(sk
);
1498 if (nladdr
->nl_pid
!= nlk
->portid
)
1501 err
= nladdr
->nl_pid
?
1502 netlink_insert(sk
, net
, nladdr
->nl_pid
) :
1503 netlink_autobind(sock
);
1508 if (!nladdr
->nl_groups
&& (nlk
->groups
== NULL
|| !(u32
)nlk
->groups
[0]))
1511 netlink_table_grab();
1512 netlink_update_subscriptions(sk
, nlk
->subscriptions
+
1513 hweight32(nladdr
->nl_groups
) -
1514 hweight32(nlk
->groups
[0]));
1515 nlk
->groups
[0] = (nlk
->groups
[0] & ~0xffffffffUL
) | nladdr
->nl_groups
;
1516 netlink_update_listeners(sk
);
1517 netlink_table_ungrab();
1519 if (nlk
->netlink_bind
&& nlk
->groups
[0]) {
1522 for (i
=0; i
<nlk
->ngroups
; i
++) {
1523 if (test_bit(i
, nlk
->groups
))
1524 nlk
->netlink_bind(i
);
1531 static int netlink_connect(struct socket
*sock
, struct sockaddr
*addr
,
1532 int alen
, int flags
)
1535 struct sock
*sk
= sock
->sk
;
1536 struct netlink_sock
*nlk
= nlk_sk(sk
);
1537 struct sockaddr_nl
*nladdr
= (struct sockaddr_nl
*)addr
;
1539 if (alen
< sizeof(addr
->sa_family
))
1542 if (addr
->sa_family
== AF_UNSPEC
) {
1543 sk
->sk_state
= NETLINK_UNCONNECTED
;
1544 nlk
->dst_portid
= 0;
1548 if (addr
->sa_family
!= AF_NETLINK
)
1551 /* Only superuser is allowed to send multicasts */
1552 if (nladdr
->nl_groups
&& !netlink_allowed(sock
, NL_CFG_F_NONROOT_SEND
))
1556 err
= netlink_autobind(sock
);
1559 sk
->sk_state
= NETLINK_CONNECTED
;
1560 nlk
->dst_portid
= nladdr
->nl_pid
;
1561 nlk
->dst_group
= ffs(nladdr
->nl_groups
);
1567 static int netlink_getname(struct socket
*sock
, struct sockaddr
*addr
,
1568 int *addr_len
, int peer
)
1570 struct sock
*sk
= sock
->sk
;
1571 struct netlink_sock
*nlk
= nlk_sk(sk
);
1572 DECLARE_SOCKADDR(struct sockaddr_nl
*, nladdr
, addr
);
1574 nladdr
->nl_family
= AF_NETLINK
;
1576 *addr_len
= sizeof(*nladdr
);
1579 nladdr
->nl_pid
= nlk
->dst_portid
;
1580 nladdr
->nl_groups
= netlink_group_mask(nlk
->dst_group
);
1582 nladdr
->nl_pid
= nlk
->portid
;
1583 nladdr
->nl_groups
= nlk
->groups
? nlk
->groups
[0] : 0;
1588 static struct sock
*netlink_getsockbyportid(struct sock
*ssk
, u32 portid
)
1591 struct netlink_sock
*nlk
;
1593 sock
= netlink_lookup(sock_net(ssk
), ssk
->sk_protocol
, portid
);
1595 return ERR_PTR(-ECONNREFUSED
);
1597 /* Don't bother queuing skb if kernel socket has no input function */
1599 if (sock
->sk_state
== NETLINK_CONNECTED
&&
1600 nlk
->dst_portid
!= nlk_sk(ssk
)->portid
) {
1602 return ERR_PTR(-ECONNREFUSED
);
1607 struct sock
*netlink_getsockbyfilp(struct file
*filp
)
1609 struct inode
*inode
= file_inode(filp
);
1612 if (!S_ISSOCK(inode
->i_mode
))
1613 return ERR_PTR(-ENOTSOCK
);
1615 sock
= SOCKET_I(inode
)->sk
;
1616 if (sock
->sk_family
!= AF_NETLINK
)
1617 return ERR_PTR(-EINVAL
);
1623 static struct sk_buff
*netlink_alloc_large_skb(unsigned int size
,
1626 struct sk_buff
*skb
;
1629 if (size
<= NLMSG_GOODSIZE
|| broadcast
)
1630 return alloc_skb(size
, GFP_KERNEL
);
1632 size
= SKB_DATA_ALIGN(size
) +
1633 SKB_DATA_ALIGN(sizeof(struct skb_shared_info
));
1635 data
= vmalloc(size
);
1639 skb
= build_skb(data
, size
);
1644 skb
->destructor
= netlink_skb_destructor
;
1651 * Attach a skb to a netlink socket.
1652 * The caller must hold a reference to the destination socket. On error, the
1653 * reference is dropped. The skb is not send to the destination, just all
1654 * all error checks are performed and memory in the queue is reserved.
1656 * < 0: error. skb freed, reference to sock dropped.
1658 * 1: repeat lookup - reference dropped while waiting for socket memory.
1660 int netlink_attachskb(struct sock
*sk
, struct sk_buff
*skb
,
1661 long *timeo
, struct sock
*ssk
)
1663 struct netlink_sock
*nlk
;
1667 if ((atomic_read(&sk
->sk_rmem_alloc
) > sk
->sk_rcvbuf
||
1668 test_bit(NETLINK_CONGESTED
, &nlk
->state
)) &&
1669 !netlink_skb_is_mmaped(skb
)) {
1670 DECLARE_WAITQUEUE(wait
, current
);
1672 if (!ssk
|| netlink_is_kernel(ssk
))
1673 netlink_overrun(sk
);
1679 __set_current_state(TASK_INTERRUPTIBLE
);
1680 add_wait_queue(&nlk
->wait
, &wait
);
1682 if ((atomic_read(&sk
->sk_rmem_alloc
) > sk
->sk_rcvbuf
||
1683 test_bit(NETLINK_CONGESTED
, &nlk
->state
)) &&
1684 !sock_flag(sk
, SOCK_DEAD
))
1685 *timeo
= schedule_timeout(*timeo
);
1687 __set_current_state(TASK_RUNNING
);
1688 remove_wait_queue(&nlk
->wait
, &wait
);
1691 if (signal_pending(current
)) {
1693 return sock_intr_errno(*timeo
);
1697 netlink_skb_set_owner_r(skb
, sk
);
1701 static int __netlink_sendskb(struct sock
*sk
, struct sk_buff
*skb
)
1705 netlink_deliver_tap(skb
);
1707 #ifdef CONFIG_NETLINK_MMAP
1708 if (netlink_skb_is_mmaped(skb
))
1709 netlink_queue_mmaped_skb(sk
, skb
);
1710 else if (netlink_rx_is_mmaped(sk
))
1711 netlink_ring_set_copied(sk
, skb
);
1713 #endif /* CONFIG_NETLINK_MMAP */
1714 skb_queue_tail(&sk
->sk_receive_queue
, skb
);
1715 sk
->sk_data_ready(sk
, len
);
1719 int netlink_sendskb(struct sock
*sk
, struct sk_buff
*skb
)
1721 int len
= __netlink_sendskb(sk
, skb
);
1727 void netlink_detachskb(struct sock
*sk
, struct sk_buff
*skb
)
1733 static struct sk_buff
*netlink_trim(struct sk_buff
*skb
, gfp_t allocation
)
1737 WARN_ON(skb
->sk
!= NULL
);
1738 if (netlink_skb_is_mmaped(skb
))
1741 delta
= skb
->end
- skb
->tail
;
1742 if (is_vmalloc_addr(skb
->head
) || delta
* 2 < skb
->truesize
)
1745 if (skb_shared(skb
)) {
1746 struct sk_buff
*nskb
= skb_clone(skb
, allocation
);
1753 if (!pskb_expand_head(skb
, 0, -delta
, allocation
))
1754 skb
->truesize
-= delta
;
1759 static int netlink_unicast_kernel(struct sock
*sk
, struct sk_buff
*skb
,
1763 struct netlink_sock
*nlk
= nlk_sk(sk
);
1765 ret
= -ECONNREFUSED
;
1766 if (nlk
->netlink_rcv
!= NULL
) {
1767 /* We could do a netlink_deliver_tap(skb) here as well
1768 * but since this is intended for the kernel only, we
1769 * should rather let it stay under the hood.
1773 netlink_skb_set_owner_r(skb
, sk
);
1774 NETLINK_CB(skb
).sk
= ssk
;
1775 nlk
->netlink_rcv(skb
);
1784 int netlink_unicast(struct sock
*ssk
, struct sk_buff
*skb
,
1785 u32 portid
, int nonblock
)
1791 skb
= netlink_trim(skb
, gfp_any());
1793 timeo
= sock_sndtimeo(ssk
, nonblock
);
1795 sk
= netlink_getsockbyportid(ssk
, portid
);
1800 if (netlink_is_kernel(sk
))
1801 return netlink_unicast_kernel(sk
, skb
, ssk
);
1803 if (sk_filter(sk
, skb
)) {
1810 err
= netlink_attachskb(sk
, skb
, &timeo
, ssk
);
1816 return netlink_sendskb(sk
, skb
);
1818 EXPORT_SYMBOL(netlink_unicast
);
1820 struct sk_buff
*netlink_alloc_skb(struct sock
*ssk
, unsigned int size
,
1821 u32 dst_portid
, gfp_t gfp_mask
)
1823 #ifdef CONFIG_NETLINK_MMAP
1824 struct sock
*sk
= NULL
;
1825 struct sk_buff
*skb
;
1826 struct netlink_ring
*ring
;
1827 struct nl_mmap_hdr
*hdr
;
1828 unsigned int maxlen
;
1830 sk
= netlink_getsockbyportid(ssk
, dst_portid
);
1834 ring
= &nlk_sk(sk
)->rx_ring
;
1835 /* fast-path without atomic ops for common case: non-mmaped receiver */
1836 if (ring
->pg_vec
== NULL
)
1839 skb
= alloc_skb_head(gfp_mask
);
1843 spin_lock_bh(&sk
->sk_receive_queue
.lock
);
1844 /* check again under lock */
1845 if (ring
->pg_vec
== NULL
)
1848 maxlen
= ring
->frame_size
- NL_MMAP_HDRLEN
;
1852 netlink_forward_ring(ring
);
1853 hdr
= netlink_current_frame(ring
, NL_MMAP_STATUS_UNUSED
);
1856 netlink_ring_setup_skb(skb
, sk
, ring
, hdr
);
1857 netlink_set_status(hdr
, NL_MMAP_STATUS_RESERVED
);
1858 atomic_inc(&ring
->pending
);
1859 netlink_increment_head(ring
);
1861 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
1866 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
1867 netlink_overrun(sk
);
1874 spin_unlock_bh(&sk
->sk_receive_queue
.lock
);
1879 return alloc_skb(size
, gfp_mask
);
1881 EXPORT_SYMBOL_GPL(netlink_alloc_skb
);
1883 int netlink_has_listeners(struct sock
*sk
, unsigned int group
)
1886 struct listeners
*listeners
;
1888 BUG_ON(!netlink_is_kernel(sk
));
1891 listeners
= rcu_dereference(nl_table
[sk
->sk_protocol
].listeners
);
1893 if (listeners
&& group
- 1 < nl_table
[sk
->sk_protocol
].groups
)
1894 res
= test_bit(group
- 1, listeners
->masks
);
1900 EXPORT_SYMBOL_GPL(netlink_has_listeners
);
1902 static int netlink_broadcast_deliver(struct sock
*sk
, struct sk_buff
*skb
)
1904 struct netlink_sock
*nlk
= nlk_sk(sk
);
1906 if (atomic_read(&sk
->sk_rmem_alloc
) <= sk
->sk_rcvbuf
&&
1907 !test_bit(NETLINK_CONGESTED
, &nlk
->state
)) {
1908 netlink_skb_set_owner_r(skb
, sk
);
1909 __netlink_sendskb(sk
, skb
);
1910 return atomic_read(&sk
->sk_rmem_alloc
) > (sk
->sk_rcvbuf
>> 1);
1915 struct netlink_broadcast_data
{
1916 struct sock
*exclude_sk
;
1921 int delivery_failure
;
1925 struct sk_buff
*skb
, *skb2
;
1926 int (*tx_filter
)(struct sock
*dsk
, struct sk_buff
*skb
, void *data
);
1930 static int do_one_broadcast(struct sock
*sk
,
1931 struct netlink_broadcast_data
*p
)
1933 struct netlink_sock
*nlk
= nlk_sk(sk
);
1936 if (p
->exclude_sk
== sk
)
1939 if (nlk
->portid
== p
->portid
|| p
->group
- 1 >= nlk
->ngroups
||
1940 !test_bit(p
->group
- 1, nlk
->groups
))
1943 if (!net_eq(sock_net(sk
), p
->net
))
1947 netlink_overrun(sk
);
1952 if (p
->skb2
== NULL
) {
1953 if (skb_shared(p
->skb
)) {
1954 p
->skb2
= skb_clone(p
->skb
, p
->allocation
);
1956 p
->skb2
= skb_get(p
->skb
);
1958 * skb ownership may have been set when
1959 * delivered to a previous socket.
1961 skb_orphan(p
->skb2
);
1964 if (p
->skb2
== NULL
) {
1965 netlink_overrun(sk
);
1966 /* Clone failed. Notify ALL listeners. */
1968 if (nlk
->flags
& NETLINK_BROADCAST_SEND_ERROR
)
1969 p
->delivery_failure
= 1;
1970 } else if (p
->tx_filter
&& p
->tx_filter(sk
, p
->skb2
, p
->tx_data
)) {
1973 } else if (sk_filter(sk
, p
->skb2
)) {
1976 } else if ((val
= netlink_broadcast_deliver(sk
, p
->skb2
)) < 0) {
1977 netlink_overrun(sk
);
1978 if (nlk
->flags
& NETLINK_BROADCAST_SEND_ERROR
)
1979 p
->delivery_failure
= 1;
1981 p
->congested
|= val
;
1991 int netlink_broadcast_filtered(struct sock
*ssk
, struct sk_buff
*skb
, u32 portid
,
1992 u32 group
, gfp_t allocation
,
1993 int (*filter
)(struct sock
*dsk
, struct sk_buff
*skb
, void *data
),
1996 struct net
*net
= sock_net(ssk
);
1997 struct netlink_broadcast_data info
;
2000 skb
= netlink_trim(skb
, allocation
);
2002 info
.exclude_sk
= ssk
;
2004 info
.portid
= portid
;
2007 info
.delivery_failure
= 0;
2010 info
.allocation
= allocation
;
2013 info
.tx_filter
= filter
;
2014 info
.tx_data
= filter_data
;
2016 /* While we sleep in clone, do not allow to change socket list */
2018 netlink_lock_table();
2020 sk_for_each_bound(sk
, &nl_table
[ssk
->sk_protocol
].mc_list
)
2021 do_one_broadcast(sk
, &info
);
2025 netlink_unlock_table();
2027 if (info
.delivery_failure
) {
2028 kfree_skb(info
.skb2
);
2031 consume_skb(info
.skb2
);
2033 if (info
.delivered
) {
2034 if (info
.congested
&& (allocation
& __GFP_WAIT
))
2040 EXPORT_SYMBOL(netlink_broadcast_filtered
);
2042 int netlink_broadcast(struct sock
*ssk
, struct sk_buff
*skb
, u32 portid
,
2043 u32 group
, gfp_t allocation
)
2045 return netlink_broadcast_filtered(ssk
, skb
, portid
, group
, allocation
,
2048 EXPORT_SYMBOL(netlink_broadcast
);
2050 struct netlink_set_err_data
{
2051 struct sock
*exclude_sk
;
2057 static int do_one_set_err(struct sock
*sk
, struct netlink_set_err_data
*p
)
2059 struct netlink_sock
*nlk
= nlk_sk(sk
);
2062 if (sk
== p
->exclude_sk
)
2065 if (!net_eq(sock_net(sk
), sock_net(p
->exclude_sk
)))
2068 if (nlk
->portid
== p
->portid
|| p
->group
- 1 >= nlk
->ngroups
||
2069 !test_bit(p
->group
- 1, nlk
->groups
))
2072 if (p
->code
== ENOBUFS
&& nlk
->flags
& NETLINK_RECV_NO_ENOBUFS
) {
2077 sk
->sk_err
= p
->code
;
2078 sk
->sk_error_report(sk
);
2084 * netlink_set_err - report error to broadcast listeners
2085 * @ssk: the kernel netlink socket, as returned by netlink_kernel_create()
2086 * @portid: the PORTID of a process that we want to skip (if any)
2087 * @groups: the broadcast group that will notice the error
2088 * @code: error code, must be negative (as usual in kernelspace)
2090 * This function returns the number of broadcast listeners that have set the
2091 * NETLINK_RECV_NO_ENOBUFS socket option.
2093 int netlink_set_err(struct sock
*ssk
, u32 portid
, u32 group
, int code
)
2095 struct netlink_set_err_data info
;
2099 info
.exclude_sk
= ssk
;
2100 info
.portid
= portid
;
2102 /* sk->sk_err wants a positive error value */
2105 read_lock(&nl_table_lock
);
2107 sk_for_each_bound(sk
, &nl_table
[ssk
->sk_protocol
].mc_list
)
2108 ret
+= do_one_set_err(sk
, &info
);
2110 read_unlock(&nl_table_lock
);
2113 EXPORT_SYMBOL(netlink_set_err
);
2115 /* must be called with netlink table grabbed */
2116 static void netlink_update_socket_mc(struct netlink_sock
*nlk
,
2120 int old
, new = !!is_new
, subscriptions
;
2122 old
= test_bit(group
- 1, nlk
->groups
);
2123 subscriptions
= nlk
->subscriptions
- old
+ new;
2125 __set_bit(group
- 1, nlk
->groups
);
2127 __clear_bit(group
- 1, nlk
->groups
);
2128 netlink_update_subscriptions(&nlk
->sk
, subscriptions
);
2129 netlink_update_listeners(&nlk
->sk
);
2132 static int netlink_setsockopt(struct socket
*sock
, int level
, int optname
,
2133 char __user
*optval
, unsigned int optlen
)
2135 struct sock
*sk
= sock
->sk
;
2136 struct netlink_sock
*nlk
= nlk_sk(sk
);
2137 unsigned int val
= 0;
2140 if (level
!= SOL_NETLINK
)
2141 return -ENOPROTOOPT
;
2143 if (optname
!= NETLINK_RX_RING
&& optname
!= NETLINK_TX_RING
&&
2144 optlen
>= sizeof(int) &&
2145 get_user(val
, (unsigned int __user
*)optval
))
2149 case NETLINK_PKTINFO
:
2151 nlk
->flags
|= NETLINK_RECV_PKTINFO
;
2153 nlk
->flags
&= ~NETLINK_RECV_PKTINFO
;
2156 case NETLINK_ADD_MEMBERSHIP
:
2157 case NETLINK_DROP_MEMBERSHIP
: {
2158 if (!netlink_allowed(sock
, NL_CFG_F_NONROOT_RECV
))
2160 err
= netlink_realloc_groups(sk
);
2163 if (!val
|| val
- 1 >= nlk
->ngroups
)
2165 netlink_table_grab();
2166 netlink_update_socket_mc(nlk
, val
,
2167 optname
== NETLINK_ADD_MEMBERSHIP
);
2168 netlink_table_ungrab();
2170 if (nlk
->netlink_bind
)
2171 nlk
->netlink_bind(val
);
2176 case NETLINK_BROADCAST_ERROR
:
2178 nlk
->flags
|= NETLINK_BROADCAST_SEND_ERROR
;
2180 nlk
->flags
&= ~NETLINK_BROADCAST_SEND_ERROR
;
2183 case NETLINK_NO_ENOBUFS
:
2185 nlk
->flags
|= NETLINK_RECV_NO_ENOBUFS
;
2186 clear_bit(NETLINK_CONGESTED
, &nlk
->state
);
2187 wake_up_interruptible(&nlk
->wait
);
2189 nlk
->flags
&= ~NETLINK_RECV_NO_ENOBUFS
;
2193 #ifdef CONFIG_NETLINK_MMAP
2194 case NETLINK_RX_RING
:
2195 case NETLINK_TX_RING
: {
2196 struct nl_mmap_req req
;
2198 /* Rings might consume more memory than queue limits, require
2201 if (!capable(CAP_NET_ADMIN
))
2203 if (optlen
< sizeof(req
))
2205 if (copy_from_user(&req
, optval
, sizeof(req
)))
2207 err
= netlink_set_ring(sk
, &req
, false,
2208 optname
== NETLINK_TX_RING
);
2211 #endif /* CONFIG_NETLINK_MMAP */
2218 static int netlink_getsockopt(struct socket
*sock
, int level
, int optname
,
2219 char __user
*optval
, int __user
*optlen
)
2221 struct sock
*sk
= sock
->sk
;
2222 struct netlink_sock
*nlk
= nlk_sk(sk
);
2225 if (level
!= SOL_NETLINK
)
2226 return -ENOPROTOOPT
;
2228 if (get_user(len
, optlen
))
2234 case NETLINK_PKTINFO
:
2235 if (len
< sizeof(int))
2238 val
= nlk
->flags
& NETLINK_RECV_PKTINFO
? 1 : 0;
2239 if (put_user(len
, optlen
) ||
2240 put_user(val
, optval
))
2244 case NETLINK_BROADCAST_ERROR
:
2245 if (len
< sizeof(int))
2248 val
= nlk
->flags
& NETLINK_BROADCAST_SEND_ERROR
? 1 : 0;
2249 if (put_user(len
, optlen
) ||
2250 put_user(val
, optval
))
2254 case NETLINK_NO_ENOBUFS
:
2255 if (len
< sizeof(int))
2258 val
= nlk
->flags
& NETLINK_RECV_NO_ENOBUFS
? 1 : 0;
2259 if (put_user(len
, optlen
) ||
2260 put_user(val
, optval
))
2270 static void netlink_cmsg_recv_pktinfo(struct msghdr
*msg
, struct sk_buff
*skb
)
2272 struct nl_pktinfo info
;
2274 info
.group
= NETLINK_CB(skb
).dst_group
;
2275 put_cmsg(msg
, SOL_NETLINK
, NETLINK_PKTINFO
, sizeof(info
), &info
);
2278 static int netlink_sendmsg(struct kiocb
*kiocb
, struct socket
*sock
,
2279 struct msghdr
*msg
, size_t len
)
2281 struct sock_iocb
*siocb
= kiocb_to_siocb(kiocb
);
2282 struct sock
*sk
= sock
->sk
;
2283 struct netlink_sock
*nlk
= nlk_sk(sk
);
2284 struct sockaddr_nl
*addr
= msg
->msg_name
;
2287 struct sk_buff
*skb
;
2289 struct scm_cookie scm
;
2290 u32 netlink_skb_flags
= 0;
2292 if (msg
->msg_flags
&MSG_OOB
)
2295 if (NULL
== siocb
->scm
)
2298 err
= scm_send(sock
, msg
, siocb
->scm
, true);
2302 if (msg
->msg_namelen
) {
2304 if (addr
->nl_family
!= AF_NETLINK
)
2306 dst_portid
= addr
->nl_pid
;
2307 dst_group
= ffs(addr
->nl_groups
);
2309 if ((dst_group
|| dst_portid
) &&
2310 !netlink_allowed(sock
, NL_CFG_F_NONROOT_SEND
))
2312 netlink_skb_flags
|= NETLINK_SKB_DST
;
2314 dst_portid
= nlk
->dst_portid
;
2315 dst_group
= nlk
->dst_group
;
2319 err
= netlink_autobind(sock
);
2324 if (netlink_tx_is_mmaped(sk
) &&
2325 msg
->msg_iov
->iov_base
== NULL
) {
2326 err
= netlink_mmap_sendmsg(sk
, msg
, dst_portid
, dst_group
,
2332 if (len
> sk
->sk_sndbuf
- 32)
2335 skb
= netlink_alloc_large_skb(len
, dst_group
);
2339 NETLINK_CB(skb
).portid
= nlk
->portid
;
2340 NETLINK_CB(skb
).dst_group
= dst_group
;
2341 NETLINK_CB(skb
).creds
= siocb
->scm
->creds
;
2342 NETLINK_CB(skb
).flags
= netlink_skb_flags
;
2345 if (memcpy_fromiovec(skb_put(skb
, len
), msg
->msg_iov
, len
)) {
2350 err
= security_netlink_send(sk
, skb
);
2357 atomic_inc(&skb
->users
);
2358 netlink_broadcast(sk
, skb
, dst_portid
, dst_group
, GFP_KERNEL
);
2360 err
= netlink_unicast(sk
, skb
, dst_portid
, msg
->msg_flags
&MSG_DONTWAIT
);
2363 scm_destroy(siocb
->scm
);
2367 static int netlink_recvmsg(struct kiocb
*kiocb
, struct socket
*sock
,
2368 struct msghdr
*msg
, size_t len
,
2371 struct sock_iocb
*siocb
= kiocb_to_siocb(kiocb
);
2372 struct scm_cookie scm
;
2373 struct sock
*sk
= sock
->sk
;
2374 struct netlink_sock
*nlk
= nlk_sk(sk
);
2375 int noblock
= flags
&MSG_DONTWAIT
;
2377 struct sk_buff
*skb
, *data_skb
;
2385 skb
= skb_recv_datagram(sk
, flags
, noblock
, &err
);
2391 #ifdef CONFIG_COMPAT_NETLINK_MESSAGES
2392 if (unlikely(skb_shinfo(skb
)->frag_list
)) {
2394 * If this skb has a frag_list, then here that means that we
2395 * will have to use the frag_list skb's data for compat tasks
2396 * and the regular skb's data for normal (non-compat) tasks.
2398 * If we need to send the compat skb, assign it to the
2399 * 'data_skb' variable so that it will be used below for data
2400 * copying. We keep 'skb' for everything else, including
2401 * freeing both later.
2403 if (flags
& MSG_CMSG_COMPAT
)
2404 data_skb
= skb_shinfo(skb
)->frag_list
;
2408 copied
= data_skb
->len
;
2410 msg
->msg_flags
|= MSG_TRUNC
;
2414 skb_reset_transport_header(data_skb
);
2415 err
= skb_copy_datagram_iovec(data_skb
, 0, msg
->msg_iov
, copied
);
2417 if (msg
->msg_name
) {
2418 struct sockaddr_nl
*addr
= (struct sockaddr_nl
*)msg
->msg_name
;
2419 addr
->nl_family
= AF_NETLINK
;
2421 addr
->nl_pid
= NETLINK_CB(skb
).portid
;
2422 addr
->nl_groups
= netlink_group_mask(NETLINK_CB(skb
).dst_group
);
2423 msg
->msg_namelen
= sizeof(*addr
);
2426 if (nlk
->flags
& NETLINK_RECV_PKTINFO
)
2427 netlink_cmsg_recv_pktinfo(msg
, skb
);
2429 if (NULL
== siocb
->scm
) {
2430 memset(&scm
, 0, sizeof(scm
));
2433 siocb
->scm
->creds
= *NETLINK_CREDS(skb
);
2434 if (flags
& MSG_TRUNC
)
2435 copied
= data_skb
->len
;
2437 skb_free_datagram(sk
, skb
);
2439 if (nlk
->cb_running
&&
2440 atomic_read(&sk
->sk_rmem_alloc
) <= sk
->sk_rcvbuf
/ 2) {
2441 ret
= netlink_dump(sk
);
2444 sk
->sk_error_report(sk
);
2448 scm_recv(sock
, msg
, siocb
->scm
, flags
);
2450 netlink_rcv_wake(sk
);
2451 return err
? : copied
;
2454 static void netlink_data_ready(struct sock
*sk
, int len
)
2460 * We export these functions to other modules. They provide a
2461 * complete set of kernel non-blocking support for message
2466 __netlink_kernel_create(struct net
*net
, int unit
, struct module
*module
,
2467 struct netlink_kernel_cfg
*cfg
)
2469 struct socket
*sock
;
2471 struct netlink_sock
*nlk
;
2472 struct listeners
*listeners
= NULL
;
2473 struct mutex
*cb_mutex
= cfg
? cfg
->cb_mutex
: NULL
;
2474 unsigned int groups
;
2478 if (unit
< 0 || unit
>= MAX_LINKS
)
2481 if (sock_create_lite(PF_NETLINK
, SOCK_DGRAM
, unit
, &sock
))
2485 * We have to just have a reference on the net from sk, but don't
2486 * get_net it. Besides, we cannot get and then put the net here.
2487 * So we create one inside init_net and the move it to net.
2490 if (__netlink_create(&init_net
, sock
, cb_mutex
, unit
) < 0)
2491 goto out_sock_release_nosk
;
2494 sk_change_net(sk
, net
);
2496 if (!cfg
|| cfg
->groups
< 32)
2499 groups
= cfg
->groups
;
2501 listeners
= kzalloc(sizeof(*listeners
) + NLGRPSZ(groups
), GFP_KERNEL
);
2503 goto out_sock_release
;
2505 sk
->sk_data_ready
= netlink_data_ready
;
2506 if (cfg
&& cfg
->input
)
2507 nlk_sk(sk
)->netlink_rcv
= cfg
->input
;
2509 if (netlink_insert(sk
, net
, 0))
2510 goto out_sock_release
;
2513 nlk
->flags
|= NETLINK_KERNEL_SOCKET
;
2515 netlink_table_grab();
2516 if (!nl_table
[unit
].registered
) {
2517 nl_table
[unit
].groups
= groups
;
2518 rcu_assign_pointer(nl_table
[unit
].listeners
, listeners
);
2519 nl_table
[unit
].cb_mutex
= cb_mutex
;
2520 nl_table
[unit
].module
= module
;
2522 nl_table
[unit
].bind
= cfg
->bind
;
2523 nl_table
[unit
].flags
= cfg
->flags
;
2525 nl_table
[unit
].compare
= cfg
->compare
;
2527 nl_table
[unit
].registered
= 1;
2530 nl_table
[unit
].registered
++;
2532 netlink_table_ungrab();
2537 netlink_kernel_release(sk
);
2540 out_sock_release_nosk
:
2544 EXPORT_SYMBOL(__netlink_kernel_create
);
2547 netlink_kernel_release(struct sock
*sk
)
2549 sk_release_kernel(sk
);
2551 EXPORT_SYMBOL(netlink_kernel_release
);
2553 int __netlink_change_ngroups(struct sock
*sk
, unsigned int groups
)
2555 struct listeners
*new, *old
;
2556 struct netlink_table
*tbl
= &nl_table
[sk
->sk_protocol
];
2561 if (NLGRPSZ(tbl
->groups
) < NLGRPSZ(groups
)) {
2562 new = kzalloc(sizeof(*new) + NLGRPSZ(groups
), GFP_ATOMIC
);
2565 old
= nl_deref_protected(tbl
->listeners
);
2566 memcpy(new->masks
, old
->masks
, NLGRPSZ(tbl
->groups
));
2567 rcu_assign_pointer(tbl
->listeners
, new);
2569 kfree_rcu(old
, rcu
);
2571 tbl
->groups
= groups
;
2577 * netlink_change_ngroups - change number of multicast groups
2579 * This changes the number of multicast groups that are available
2580 * on a certain netlink family. Note that it is not possible to
2581 * change the number of groups to below 32. Also note that it does
2582 * not implicitly call netlink_clear_multicast_users() when the
2583 * number of groups is reduced.
2585 * @sk: The kernel netlink socket, as returned by netlink_kernel_create().
2586 * @groups: The new number of groups.
2588 int netlink_change_ngroups(struct sock
*sk
, unsigned int groups
)
2592 netlink_table_grab();
2593 err
= __netlink_change_ngroups(sk
, groups
);
2594 netlink_table_ungrab();
2599 void __netlink_clear_multicast_users(struct sock
*ksk
, unsigned int group
)
2602 struct netlink_table
*tbl
= &nl_table
[ksk
->sk_protocol
];
2604 sk_for_each_bound(sk
, &tbl
->mc_list
)
2605 netlink_update_socket_mc(nlk_sk(sk
), group
, 0);
2609 * netlink_clear_multicast_users - kick off multicast listeners
2611 * This function removes all listeners from the given group.
2612 * @ksk: The kernel netlink socket, as returned by
2613 * netlink_kernel_create().
2614 * @group: The multicast group to clear.
2616 void netlink_clear_multicast_users(struct sock
*ksk
, unsigned int group
)
2618 netlink_table_grab();
2619 __netlink_clear_multicast_users(ksk
, group
);
2620 netlink_table_ungrab();
2624 __nlmsg_put(struct sk_buff
*skb
, u32 portid
, u32 seq
, int type
, int len
, int flags
)
2626 struct nlmsghdr
*nlh
;
2627 int size
= nlmsg_msg_size(len
);
2629 nlh
= (struct nlmsghdr
*)skb_put(skb
, NLMSG_ALIGN(size
));
2630 nlh
->nlmsg_type
= type
;
2631 nlh
->nlmsg_len
= size
;
2632 nlh
->nlmsg_flags
= flags
;
2633 nlh
->nlmsg_pid
= portid
;
2634 nlh
->nlmsg_seq
= seq
;
2635 if (!__builtin_constant_p(size
) || NLMSG_ALIGN(size
) - size
!= 0)
2636 memset(nlmsg_data(nlh
) + len
, 0, NLMSG_ALIGN(size
) - size
);
2639 EXPORT_SYMBOL(__nlmsg_put
);
2642 * It looks a bit ugly.
2643 * It would be better to create kernel thread.
2646 static int netlink_dump(struct sock
*sk
)
2648 struct netlink_sock
*nlk
= nlk_sk(sk
);
2649 struct netlink_callback
*cb
;
2650 struct sk_buff
*skb
= NULL
;
2651 struct nlmsghdr
*nlh
;
2652 int len
, err
= -ENOBUFS
;
2655 mutex_lock(nlk
->cb_mutex
);
2656 if (!nlk
->cb_running
) {
2662 alloc_size
= max_t(int, cb
->min_dump_alloc
, NLMSG_GOODSIZE
);
2664 if (!netlink_rx_is_mmaped(sk
) &&
2665 atomic_read(&sk
->sk_rmem_alloc
) >= sk
->sk_rcvbuf
)
2667 skb
= netlink_alloc_skb(sk
, alloc_size
, nlk
->portid
, GFP_KERNEL
);
2670 netlink_skb_set_owner_r(skb
, sk
);
2672 len
= cb
->dump(skb
, cb
);
2675 mutex_unlock(nlk
->cb_mutex
);
2677 if (sk_filter(sk
, skb
))
2680 __netlink_sendskb(sk
, skb
);
2684 nlh
= nlmsg_put_answer(skb
, cb
, NLMSG_DONE
, sizeof(len
), NLM_F_MULTI
);
2688 nl_dump_check_consistent(cb
, nlh
);
2690 memcpy(nlmsg_data(nlh
), &len
, sizeof(len
));
2692 if (sk_filter(sk
, skb
))
2695 __netlink_sendskb(sk
, skb
);
2700 nlk
->cb_running
= false;
2701 mutex_unlock(nlk
->cb_mutex
);
2702 module_put(cb
->module
);
2703 consume_skb(cb
->skb
);
2707 mutex_unlock(nlk
->cb_mutex
);
2712 int __netlink_dump_start(struct sock
*ssk
, struct sk_buff
*skb
,
2713 const struct nlmsghdr
*nlh
,
2714 struct netlink_dump_control
*control
)
2716 struct netlink_callback
*cb
;
2718 struct netlink_sock
*nlk
;
2721 /* Memory mapped dump requests need to be copied to avoid looping
2722 * on the pending state in netlink_mmap_sendmsg() while the CB hold
2723 * a reference to the skb.
2725 if (netlink_skb_is_mmaped(skb
)) {
2726 skb
= skb_copy(skb
, GFP_KERNEL
);
2730 atomic_inc(&skb
->users
);
2732 sk
= netlink_lookup(sock_net(ssk
), ssk
->sk_protocol
, NETLINK_CB(skb
).portid
);
2734 ret
= -ECONNREFUSED
;
2739 mutex_lock(nlk
->cb_mutex
);
2740 /* A dump is in progress... */
2741 if (nlk
->cb_running
) {
2745 /* add reference of module which cb->dump belongs to */
2746 if (!try_module_get(control
->module
)) {
2747 ret
= -EPROTONOSUPPORT
;
2752 memset(cb
, 0, sizeof(*cb
));
2753 cb
->dump
= control
->dump
;
2754 cb
->done
= control
->done
;
2756 cb
->data
= control
->data
;
2757 cb
->module
= control
->module
;
2758 cb
->min_dump_alloc
= control
->min_dump_alloc
;
2761 nlk
->cb_running
= true;
2763 mutex_unlock(nlk
->cb_mutex
);
2765 ret
= netlink_dump(sk
);
2771 /* We successfully started a dump, by returning -EINTR we
2772 * signal not to send ACK even if it was requested.
2778 mutex_unlock(nlk
->cb_mutex
);
2783 EXPORT_SYMBOL(__netlink_dump_start
);
2785 void netlink_ack(struct sk_buff
*in_skb
, struct nlmsghdr
*nlh
, int err
)
2787 struct sk_buff
*skb
;
2788 struct nlmsghdr
*rep
;
2789 struct nlmsgerr
*errmsg
;
2790 size_t payload
= sizeof(*errmsg
);
2792 /* error messages get the original request appened */
2794 payload
+= nlmsg_len(nlh
);
2796 skb
= netlink_alloc_skb(in_skb
->sk
, nlmsg_total_size(payload
),
2797 NETLINK_CB(in_skb
).portid
, GFP_KERNEL
);
2801 sk
= netlink_lookup(sock_net(in_skb
->sk
),
2802 in_skb
->sk
->sk_protocol
,
2803 NETLINK_CB(in_skb
).portid
);
2805 sk
->sk_err
= ENOBUFS
;
2806 sk
->sk_error_report(sk
);
2812 rep
= __nlmsg_put(skb
, NETLINK_CB(in_skb
).portid
, nlh
->nlmsg_seq
,
2813 NLMSG_ERROR
, payload
, 0);
2814 errmsg
= nlmsg_data(rep
);
2815 errmsg
->error
= err
;
2816 memcpy(&errmsg
->msg
, nlh
, err
? nlh
->nlmsg_len
: sizeof(*nlh
));
2817 netlink_unicast(in_skb
->sk
, skb
, NETLINK_CB(in_skb
).portid
, MSG_DONTWAIT
);
2819 EXPORT_SYMBOL(netlink_ack
);
2821 int netlink_rcv_skb(struct sk_buff
*skb
, int (*cb
)(struct sk_buff
*,
2824 struct nlmsghdr
*nlh
;
2827 while (skb
->len
>= nlmsg_total_size(0)) {
2830 nlh
= nlmsg_hdr(skb
);
2833 if (nlh
->nlmsg_len
< NLMSG_HDRLEN
|| skb
->len
< nlh
->nlmsg_len
)
2836 /* Only requests are handled by the kernel */
2837 if (!(nlh
->nlmsg_flags
& NLM_F_REQUEST
))
2840 /* Skip control messages */
2841 if (nlh
->nlmsg_type
< NLMSG_MIN_TYPE
)
2849 if (nlh
->nlmsg_flags
& NLM_F_ACK
|| err
)
2850 netlink_ack(skb
, nlh
, err
);
2853 msglen
= NLMSG_ALIGN(nlh
->nlmsg_len
);
2854 if (msglen
> skb
->len
)
2856 skb_pull(skb
, msglen
);
2861 EXPORT_SYMBOL(netlink_rcv_skb
);
2864 * nlmsg_notify - send a notification netlink message
2865 * @sk: netlink socket to use
2866 * @skb: notification message
2867 * @portid: destination netlink portid for reports or 0
2868 * @group: destination multicast group or 0
2869 * @report: 1 to report back, 0 to disable
2870 * @flags: allocation flags
2872 int nlmsg_notify(struct sock
*sk
, struct sk_buff
*skb
, u32 portid
,
2873 unsigned int group
, int report
, gfp_t flags
)
2878 int exclude_portid
= 0;
2881 atomic_inc(&skb
->users
);
2882 exclude_portid
= portid
;
2885 /* errors reported via destination sk->sk_err, but propagate
2886 * delivery errors if NETLINK_BROADCAST_ERROR flag is set */
2887 err
= nlmsg_multicast(sk
, skb
, exclude_portid
, group
, flags
);
2893 err2
= nlmsg_unicast(sk
, skb
, portid
);
2894 if (!err
|| err
== -ESRCH
)
2900 EXPORT_SYMBOL(nlmsg_notify
);
2902 #ifdef CONFIG_PROC_FS
2903 struct nl_seq_iter
{
2904 struct seq_net_private p
;
2909 static struct sock
*netlink_seq_socket_idx(struct seq_file
*seq
, loff_t pos
)
2911 struct nl_seq_iter
*iter
= seq
->private;
2916 for (i
= 0; i
< MAX_LINKS
; i
++) {
2917 struct nl_portid_hash
*hash
= &nl_table
[i
].hash
;
2919 for (j
= 0; j
<= hash
->mask
; j
++) {
2920 sk_for_each(s
, &hash
->table
[j
]) {
2921 if (sock_net(s
) != seq_file_net(seq
))
2935 static void *netlink_seq_start(struct seq_file
*seq
, loff_t
*pos
)
2936 __acquires(nl_table_lock
)
2938 read_lock(&nl_table_lock
);
2939 return *pos
? netlink_seq_socket_idx(seq
, *pos
- 1) : SEQ_START_TOKEN
;
2942 static void *netlink_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
2945 struct nl_seq_iter
*iter
;
2951 if (v
== SEQ_START_TOKEN
)
2952 return netlink_seq_socket_idx(seq
, 0);
2954 net
= seq_file_net(seq
);
2955 iter
= seq
->private;
2959 } while (s
&& !nl_table
[s
->sk_protocol
].compare(net
, s
));
2964 j
= iter
->hash_idx
+ 1;
2967 struct nl_portid_hash
*hash
= &nl_table
[i
].hash
;
2969 for (; j
<= hash
->mask
; j
++) {
2970 s
= sk_head(&hash
->table
[j
]);
2972 while (s
&& !nl_table
[s
->sk_protocol
].compare(net
, s
))
2982 } while (++i
< MAX_LINKS
);
2987 static void netlink_seq_stop(struct seq_file
*seq
, void *v
)
2988 __releases(nl_table_lock
)
2990 read_unlock(&nl_table_lock
);
2994 static int netlink_seq_show(struct seq_file
*seq
, void *v
)
2996 if (v
== SEQ_START_TOKEN
) {
2998 "sk Eth Pid Groups "
2999 "Rmem Wmem Dump Locks Drops Inode\n");
3002 struct netlink_sock
*nlk
= nlk_sk(s
);
3004 seq_printf(seq
, "%pK %-3d %-6u %08x %-8d %-8d %d %-8d %-8d %-8lu\n",
3008 nlk
->groups
? (u32
)nlk
->groups
[0] : 0,
3009 sk_rmem_alloc_get(s
),
3010 sk_wmem_alloc_get(s
),
3012 atomic_read(&s
->sk_refcnt
),
3013 atomic_read(&s
->sk_drops
),
3021 static const struct seq_operations netlink_seq_ops
= {
3022 .start
= netlink_seq_start
,
3023 .next
= netlink_seq_next
,
3024 .stop
= netlink_seq_stop
,
3025 .show
= netlink_seq_show
,
3029 static int netlink_seq_open(struct inode
*inode
, struct file
*file
)
3031 return seq_open_net(inode
, file
, &netlink_seq_ops
,
3032 sizeof(struct nl_seq_iter
));
3035 static const struct file_operations netlink_seq_fops
= {
3036 .owner
= THIS_MODULE
,
3037 .open
= netlink_seq_open
,
3039 .llseek
= seq_lseek
,
3040 .release
= seq_release_net
,
3045 int netlink_register_notifier(struct notifier_block
*nb
)
3047 return atomic_notifier_chain_register(&netlink_chain
, nb
);
3049 EXPORT_SYMBOL(netlink_register_notifier
);
3051 int netlink_unregister_notifier(struct notifier_block
*nb
)
3053 return atomic_notifier_chain_unregister(&netlink_chain
, nb
);
3055 EXPORT_SYMBOL(netlink_unregister_notifier
);
3057 static const struct proto_ops netlink_ops
= {
3058 .family
= PF_NETLINK
,
3059 .owner
= THIS_MODULE
,
3060 .release
= netlink_release
,
3061 .bind
= netlink_bind
,
3062 .connect
= netlink_connect
,
3063 .socketpair
= sock_no_socketpair
,
3064 .accept
= sock_no_accept
,
3065 .getname
= netlink_getname
,
3066 .poll
= netlink_poll
,
3067 .ioctl
= sock_no_ioctl
,
3068 .listen
= sock_no_listen
,
3069 .shutdown
= sock_no_shutdown
,
3070 .setsockopt
= netlink_setsockopt
,
3071 .getsockopt
= netlink_getsockopt
,
3072 .sendmsg
= netlink_sendmsg
,
3073 .recvmsg
= netlink_recvmsg
,
3074 .mmap
= netlink_mmap
,
3075 .sendpage
= sock_no_sendpage
,
3078 static const struct net_proto_family netlink_family_ops
= {
3079 .family
= PF_NETLINK
,
3080 .create
= netlink_create
,
3081 .owner
= THIS_MODULE
, /* for consistency 8) */
3084 static int __net_init
netlink_net_init(struct net
*net
)
3086 #ifdef CONFIG_PROC_FS
3087 if (!proc_create("netlink", 0, net
->proc_net
, &netlink_seq_fops
))
3093 static void __net_exit
netlink_net_exit(struct net
*net
)
3095 #ifdef CONFIG_PROC_FS
3096 remove_proc_entry("netlink", net
->proc_net
);
3100 static void __init
netlink_add_usersock_entry(void)
3102 struct listeners
*listeners
;
3105 listeners
= kzalloc(sizeof(*listeners
) + NLGRPSZ(groups
), GFP_KERNEL
);
3107 panic("netlink_add_usersock_entry: Cannot allocate listeners\n");
3109 netlink_table_grab();
3111 nl_table
[NETLINK_USERSOCK
].groups
= groups
;
3112 rcu_assign_pointer(nl_table
[NETLINK_USERSOCK
].listeners
, listeners
);
3113 nl_table
[NETLINK_USERSOCK
].module
= THIS_MODULE
;
3114 nl_table
[NETLINK_USERSOCK
].registered
= 1;
3115 nl_table
[NETLINK_USERSOCK
].flags
= NL_CFG_F_NONROOT_SEND
;
3117 netlink_table_ungrab();
3120 static struct pernet_operations __net_initdata netlink_net_ops
= {
3121 .init
= netlink_net_init
,
3122 .exit
= netlink_net_exit
,
3125 static int __init
netlink_proto_init(void)
3128 unsigned long limit
;
3130 int err
= proto_register(&netlink_proto
, 0);
3135 BUILD_BUG_ON(sizeof(struct netlink_skb_parms
) > FIELD_SIZEOF(struct sk_buff
, cb
));
3137 nl_table
= kcalloc(MAX_LINKS
, sizeof(*nl_table
), GFP_KERNEL
);
3141 if (totalram_pages
>= (128 * 1024))
3142 limit
= totalram_pages
>> (21 - PAGE_SHIFT
);
3144 limit
= totalram_pages
>> (23 - PAGE_SHIFT
);
3146 order
= get_bitmask_order(limit
) - 1 + PAGE_SHIFT
;
3147 limit
= (1UL << order
) / sizeof(struct hlist_head
);
3148 order
= get_bitmask_order(min(limit
, (unsigned long)UINT_MAX
)) - 1;
3150 for (i
= 0; i
< MAX_LINKS
; i
++) {
3151 struct nl_portid_hash
*hash
= &nl_table
[i
].hash
;
3153 hash
->table
= nl_portid_hash_zalloc(1 * sizeof(*hash
->table
));
3156 nl_portid_hash_free(nl_table
[i
].hash
.table
,
3157 1 * sizeof(*hash
->table
));
3161 hash
->max_shift
= order
;
3164 hash
->rehash_time
= jiffies
;
3166 nl_table
[i
].compare
= netlink_compare
;
3169 INIT_LIST_HEAD(&netlink_tap_all
);
3171 netlink_add_usersock_entry();
3173 sock_register(&netlink_family_ops
);
3174 register_pernet_subsys(&netlink_net_ops
);
3175 /* The netlink device handler may be needed early. */
3180 panic("netlink_init: Cannot allocate nl_table\n");
3183 core_initcall(netlink_proto_init
);