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 <linux/uaccess.h>
44 #include <linux/skbuff.h>
45 #include <linux/netdevice.h>
46 #include <linux/rtnetlink.h>
47 #include <linux/proc_fs.h>
48 #include <linux/seq_file.h>
49 #include <linux/notifier.h>
50 #include <linux/security.h>
51 #include <linux/jhash.h>
52 #include <linux/jiffies.h>
53 #include <linux/random.h>
54 #include <linux/bitops.h>
56 #include <linux/types.h>
57 #include <linux/audit.h>
58 #include <linux/mutex.h>
59 #include <linux/vmalloc.h>
60 #include <linux/if_arp.h>
61 #include <linux/rhashtable.h>
62 #include <asm/cacheflush.h>
63 #include <linux/hash.h>
64 #include <linux/genetlink.h>
65 #include <linux/net_namespace.h>
67 #include <net/net_namespace.h>
70 #include <net/netlink.h>
72 #include "af_netlink.h"
76 unsigned long masks
[0];
80 #define NETLINK_S_CONGESTED 0x0
82 static inline int netlink_is_kernel(struct sock
*sk
)
84 return nlk_sk(sk
)->flags
& NETLINK_F_KERNEL_SOCKET
;
87 struct netlink_table
*nl_table __read_mostly
;
88 EXPORT_SYMBOL_GPL(nl_table
);
90 static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait
);
92 static struct lock_class_key nlk_cb_mutex_keys
[MAX_LINKS
];
94 static const char *const nlk_cb_mutex_key_strings
[MAX_LINKS
+ 1] = {
97 "nlk_cb_mutex-USERSOCK",
98 "nlk_cb_mutex-FIREWALL",
99 "nlk_cb_mutex-SOCK_DIAG",
100 "nlk_cb_mutex-NFLOG",
102 "nlk_cb_mutex-SELINUX",
103 "nlk_cb_mutex-ISCSI",
104 "nlk_cb_mutex-AUDIT",
105 "nlk_cb_mutex-FIB_LOOKUP",
106 "nlk_cb_mutex-CONNECTOR",
107 "nlk_cb_mutex-NETFILTER",
108 "nlk_cb_mutex-IP6_FW",
109 "nlk_cb_mutex-DNRTMSG",
110 "nlk_cb_mutex-KOBJECT_UEVENT",
111 "nlk_cb_mutex-GENERIC",
113 "nlk_cb_mutex-SCSITRANSPORT",
114 "nlk_cb_mutex-ECRYPTFS",
116 "nlk_cb_mutex-CRYPTO",
127 "nlk_cb_mutex-MAX_LINKS"
130 static int netlink_dump(struct sock
*sk
);
131 static void netlink_skb_destructor(struct sk_buff
*skb
);
133 /* nl_table locking explained:
134 * Lookup and traversal are protected with an RCU read-side lock. Insertion
135 * and removal are protected with per bucket lock while using RCU list
136 * modification primitives and may run in parallel to RCU protected lookups.
137 * Destruction of the Netlink socket may only occur *after* nl_table_lock has
138 * been acquired * either during or after the socket has been removed from
139 * the list and after an RCU grace period.
141 DEFINE_RWLOCK(nl_table_lock
);
142 EXPORT_SYMBOL_GPL(nl_table_lock
);
143 static atomic_t nl_table_users
= ATOMIC_INIT(0);
145 #define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock));
147 static BLOCKING_NOTIFIER_HEAD(netlink_chain
);
149 static DEFINE_SPINLOCK(netlink_tap_lock
);
150 static struct list_head netlink_tap_all __read_mostly
;
152 static const struct rhashtable_params netlink_rhashtable_params
;
154 static inline u32
netlink_group_mask(u32 group
)
156 return group
? 1 << (group
- 1) : 0;
159 static struct sk_buff
*netlink_to_full_skb(const struct sk_buff
*skb
,
162 unsigned int len
= skb_end_offset(skb
);
165 new = alloc_skb(len
, gfp_mask
);
169 NETLINK_CB(new).portid
= NETLINK_CB(skb
).portid
;
170 NETLINK_CB(new).dst_group
= NETLINK_CB(skb
).dst_group
;
171 NETLINK_CB(new).creds
= NETLINK_CB(skb
).creds
;
173 skb_put_data(new, skb
->data
, len
);
177 int netlink_add_tap(struct netlink_tap
*nt
)
179 if (unlikely(nt
->dev
->type
!= ARPHRD_NETLINK
))
182 spin_lock(&netlink_tap_lock
);
183 list_add_rcu(&nt
->list
, &netlink_tap_all
);
184 spin_unlock(&netlink_tap_lock
);
186 __module_get(nt
->module
);
190 EXPORT_SYMBOL_GPL(netlink_add_tap
);
192 static int __netlink_remove_tap(struct netlink_tap
*nt
)
195 struct netlink_tap
*tmp
;
197 spin_lock(&netlink_tap_lock
);
199 list_for_each_entry(tmp
, &netlink_tap_all
, list
) {
201 list_del_rcu(&nt
->list
);
207 pr_warn("__netlink_remove_tap: %p not found\n", nt
);
209 spin_unlock(&netlink_tap_lock
);
212 module_put(nt
->module
);
214 return found
? 0 : -ENODEV
;
217 int netlink_remove_tap(struct netlink_tap
*nt
)
221 ret
= __netlink_remove_tap(nt
);
226 EXPORT_SYMBOL_GPL(netlink_remove_tap
);
228 static bool netlink_filter_tap(const struct sk_buff
*skb
)
230 struct sock
*sk
= skb
->sk
;
232 /* We take the more conservative approach and
233 * whitelist socket protocols that may pass.
235 switch (sk
->sk_protocol
) {
237 case NETLINK_USERSOCK
:
238 case NETLINK_SOCK_DIAG
:
241 case NETLINK_FIB_LOOKUP
:
242 case NETLINK_NETFILTER
:
243 case NETLINK_GENERIC
:
250 static int __netlink_deliver_tap_skb(struct sk_buff
*skb
,
251 struct net_device
*dev
)
253 struct sk_buff
*nskb
;
254 struct sock
*sk
= skb
->sk
;
259 if (is_vmalloc_addr(skb
->head
))
260 nskb
= netlink_to_full_skb(skb
, GFP_ATOMIC
);
262 nskb
= skb_clone(skb
, GFP_ATOMIC
);
265 nskb
->protocol
= htons((u16
) sk
->sk_protocol
);
266 nskb
->pkt_type
= netlink_is_kernel(sk
) ?
267 PACKET_KERNEL
: PACKET_USER
;
268 skb_reset_network_header(nskb
);
269 ret
= dev_queue_xmit(nskb
);
270 if (unlikely(ret
> 0))
271 ret
= net_xmit_errno(ret
);
278 static void __netlink_deliver_tap(struct sk_buff
*skb
)
281 struct netlink_tap
*tmp
;
283 if (!netlink_filter_tap(skb
))
286 list_for_each_entry_rcu(tmp
, &netlink_tap_all
, list
) {
287 ret
= __netlink_deliver_tap_skb(skb
, tmp
->dev
);
293 static void netlink_deliver_tap(struct sk_buff
*skb
)
297 if (unlikely(!list_empty(&netlink_tap_all
)))
298 __netlink_deliver_tap(skb
);
303 static void netlink_deliver_tap_kernel(struct sock
*dst
, struct sock
*src
,
306 if (!(netlink_is_kernel(dst
) && netlink_is_kernel(src
)))
307 netlink_deliver_tap(skb
);
310 static void netlink_overrun(struct sock
*sk
)
312 struct netlink_sock
*nlk
= nlk_sk(sk
);
314 if (!(nlk
->flags
& NETLINK_F_RECV_NO_ENOBUFS
)) {
315 if (!test_and_set_bit(NETLINK_S_CONGESTED
,
316 &nlk_sk(sk
)->state
)) {
317 sk
->sk_err
= ENOBUFS
;
318 sk
->sk_error_report(sk
);
321 atomic_inc(&sk
->sk_drops
);
324 static void netlink_rcv_wake(struct sock
*sk
)
326 struct netlink_sock
*nlk
= nlk_sk(sk
);
328 if (skb_queue_empty(&sk
->sk_receive_queue
))
329 clear_bit(NETLINK_S_CONGESTED
, &nlk
->state
);
330 if (!test_bit(NETLINK_S_CONGESTED
, &nlk
->state
))
331 wake_up_interruptible(&nlk
->wait
);
334 static void netlink_skb_destructor(struct sk_buff
*skb
)
336 if (is_vmalloc_addr(skb
->head
)) {
338 !atomic_dec_return(&(skb_shinfo(skb
)->dataref
)))
347 static void netlink_skb_set_owner_r(struct sk_buff
*skb
, struct sock
*sk
)
349 WARN_ON(skb
->sk
!= NULL
);
351 skb
->destructor
= netlink_skb_destructor
;
352 atomic_add(skb
->truesize
, &sk
->sk_rmem_alloc
);
353 sk_mem_charge(sk
, skb
->truesize
);
356 static void netlink_sock_destruct(struct sock
*sk
)
358 struct netlink_sock
*nlk
= nlk_sk(sk
);
360 if (nlk
->cb_running
) {
362 nlk
->cb
.done(&nlk
->cb
);
363 module_put(nlk
->cb
.module
);
364 kfree_skb(nlk
->cb
.skb
);
367 skb_queue_purge(&sk
->sk_receive_queue
);
369 if (!sock_flag(sk
, SOCK_DEAD
)) {
370 printk(KERN_ERR
"Freeing alive netlink socket %p\n", sk
);
374 WARN_ON(atomic_read(&sk
->sk_rmem_alloc
));
375 WARN_ON(refcount_read(&sk
->sk_wmem_alloc
));
376 WARN_ON(nlk_sk(sk
)->groups
);
379 static void netlink_sock_destruct_work(struct work_struct
*work
)
381 struct netlink_sock
*nlk
= container_of(work
, struct netlink_sock
,
387 /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on
388 * SMP. Look, when several writers sleep and reader wakes them up, all but one
389 * immediately hit write lock and grab all the cpus. Exclusive sleep solves
390 * this, _but_ remember, it adds useless work on UP machines.
393 void netlink_table_grab(void)
394 __acquires(nl_table_lock
)
398 write_lock_irq(&nl_table_lock
);
400 if (atomic_read(&nl_table_users
)) {
401 DECLARE_WAITQUEUE(wait
, current
);
403 add_wait_queue_exclusive(&nl_table_wait
, &wait
);
405 set_current_state(TASK_UNINTERRUPTIBLE
);
406 if (atomic_read(&nl_table_users
) == 0)
408 write_unlock_irq(&nl_table_lock
);
410 write_lock_irq(&nl_table_lock
);
413 __set_current_state(TASK_RUNNING
);
414 remove_wait_queue(&nl_table_wait
, &wait
);
418 void netlink_table_ungrab(void)
419 __releases(nl_table_lock
)
421 write_unlock_irq(&nl_table_lock
);
422 wake_up(&nl_table_wait
);
426 netlink_lock_table(void)
428 /* read_lock() synchronizes us to netlink_table_grab */
430 read_lock(&nl_table_lock
);
431 atomic_inc(&nl_table_users
);
432 read_unlock(&nl_table_lock
);
436 netlink_unlock_table(void)
438 if (atomic_dec_and_test(&nl_table_users
))
439 wake_up(&nl_table_wait
);
442 struct netlink_compare_arg
448 /* Doing sizeof directly may yield 4 extra bytes on 64-bit. */
449 #define netlink_compare_arg_len \
450 (offsetof(struct netlink_compare_arg, portid) + sizeof(u32))
452 static inline int netlink_compare(struct rhashtable_compare_arg
*arg
,
455 const struct netlink_compare_arg
*x
= arg
->key
;
456 const struct netlink_sock
*nlk
= ptr
;
458 return nlk
->portid
!= x
->portid
||
459 !net_eq(sock_net(&nlk
->sk
), read_pnet(&x
->pnet
));
462 static void netlink_compare_arg_init(struct netlink_compare_arg
*arg
,
463 struct net
*net
, u32 portid
)
465 memset(arg
, 0, sizeof(*arg
));
466 write_pnet(&arg
->pnet
, net
);
467 arg
->portid
= portid
;
470 static struct sock
*__netlink_lookup(struct netlink_table
*table
, u32 portid
,
473 struct netlink_compare_arg arg
;
475 netlink_compare_arg_init(&arg
, net
, portid
);
476 return rhashtable_lookup_fast(&table
->hash
, &arg
,
477 netlink_rhashtable_params
);
480 static int __netlink_insert(struct netlink_table
*table
, struct sock
*sk
)
482 struct netlink_compare_arg arg
;
484 netlink_compare_arg_init(&arg
, sock_net(sk
), nlk_sk(sk
)->portid
);
485 return rhashtable_lookup_insert_key(&table
->hash
, &arg
,
487 netlink_rhashtable_params
);
490 static struct sock
*netlink_lookup(struct net
*net
, int protocol
, u32 portid
)
492 struct netlink_table
*table
= &nl_table
[protocol
];
496 sk
= __netlink_lookup(table
, portid
, net
);
504 static const struct proto_ops netlink_ops
;
507 netlink_update_listeners(struct sock
*sk
)
509 struct netlink_table
*tbl
= &nl_table
[sk
->sk_protocol
];
512 struct listeners
*listeners
;
514 listeners
= nl_deref_protected(tbl
->listeners
);
518 for (i
= 0; i
< NLGRPLONGS(tbl
->groups
); i
++) {
520 sk_for_each_bound(sk
, &tbl
->mc_list
) {
521 if (i
< NLGRPLONGS(nlk_sk(sk
)->ngroups
))
522 mask
|= nlk_sk(sk
)->groups
[i
];
524 listeners
->masks
[i
] = mask
;
526 /* this function is only called with the netlink table "grabbed", which
527 * makes sure updates are visible before bind or setsockopt return. */
530 static int netlink_insert(struct sock
*sk
, u32 portid
)
532 struct netlink_table
*table
= &nl_table
[sk
->sk_protocol
];
537 err
= nlk_sk(sk
)->portid
== portid
? 0 : -EBUSY
;
538 if (nlk_sk(sk
)->bound
)
542 if (BITS_PER_LONG
> 32 &&
543 unlikely(atomic_read(&table
->hash
.nelems
) >= UINT_MAX
))
546 nlk_sk(sk
)->portid
= portid
;
549 err
= __netlink_insert(table
, sk
);
551 /* In case the hashtable backend returns with -EBUSY
552 * from here, it must not escape to the caller.
554 if (unlikely(err
== -EBUSY
))
562 /* We need to ensure that the socket is hashed and visible. */
564 nlk_sk(sk
)->bound
= portid
;
571 static void netlink_remove(struct sock
*sk
)
573 struct netlink_table
*table
;
575 table
= &nl_table
[sk
->sk_protocol
];
576 if (!rhashtable_remove_fast(&table
->hash
, &nlk_sk(sk
)->node
,
577 netlink_rhashtable_params
)) {
578 WARN_ON(refcount_read(&sk
->sk_refcnt
) == 1);
582 netlink_table_grab();
583 if (nlk_sk(sk
)->subscriptions
) {
584 __sk_del_bind_node(sk
);
585 netlink_update_listeners(sk
);
587 if (sk
->sk_protocol
== NETLINK_GENERIC
)
588 atomic_inc(&genl_sk_destructing_cnt
);
589 netlink_table_ungrab();
592 static struct proto netlink_proto
= {
594 .owner
= THIS_MODULE
,
595 .obj_size
= sizeof(struct netlink_sock
),
598 static int __netlink_create(struct net
*net
, struct socket
*sock
,
599 struct mutex
*cb_mutex
, int protocol
,
603 struct netlink_sock
*nlk
;
605 sock
->ops
= &netlink_ops
;
607 sk
= sk_alloc(net
, PF_NETLINK
, GFP_KERNEL
, &netlink_proto
, kern
);
611 sock_init_data(sock
, sk
);
615 nlk
->cb_mutex
= cb_mutex
;
617 nlk
->cb_mutex
= &nlk
->cb_def_mutex
;
618 mutex_init(nlk
->cb_mutex
);
619 lockdep_set_class_and_name(nlk
->cb_mutex
,
620 nlk_cb_mutex_keys
+ protocol
,
621 nlk_cb_mutex_key_strings
[protocol
]);
623 init_waitqueue_head(&nlk
->wait
);
625 sk
->sk_destruct
= netlink_sock_destruct
;
626 sk
->sk_protocol
= protocol
;
630 static int netlink_create(struct net
*net
, struct socket
*sock
, int protocol
,
633 struct module
*module
= NULL
;
634 struct mutex
*cb_mutex
;
635 struct netlink_sock
*nlk
;
636 int (*bind
)(struct net
*net
, int group
);
637 void (*unbind
)(struct net
*net
, int group
);
640 sock
->state
= SS_UNCONNECTED
;
642 if (sock
->type
!= SOCK_RAW
&& sock
->type
!= SOCK_DGRAM
)
643 return -ESOCKTNOSUPPORT
;
645 if (protocol
< 0 || protocol
>= MAX_LINKS
)
646 return -EPROTONOSUPPORT
;
648 netlink_lock_table();
649 #ifdef CONFIG_MODULES
650 if (!nl_table
[protocol
].registered
) {
651 netlink_unlock_table();
652 request_module("net-pf-%d-proto-%d", PF_NETLINK
, protocol
);
653 netlink_lock_table();
656 if (nl_table
[protocol
].registered
&&
657 try_module_get(nl_table
[protocol
].module
))
658 module
= nl_table
[protocol
].module
;
660 err
= -EPROTONOSUPPORT
;
661 cb_mutex
= nl_table
[protocol
].cb_mutex
;
662 bind
= nl_table
[protocol
].bind
;
663 unbind
= nl_table
[protocol
].unbind
;
664 netlink_unlock_table();
669 err
= __netlink_create(net
, sock
, cb_mutex
, protocol
, kern
);
674 sock_prot_inuse_add(net
, &netlink_proto
, 1);
677 nlk
= nlk_sk(sock
->sk
);
678 nlk
->module
= module
;
679 nlk
->netlink_bind
= bind
;
680 nlk
->netlink_unbind
= unbind
;
689 static void deferred_put_nlk_sk(struct rcu_head
*head
)
691 struct netlink_sock
*nlk
= container_of(head
, struct netlink_sock
, rcu
);
692 struct sock
*sk
= &nlk
->sk
;
697 if (!refcount_dec_and_test(&sk
->sk_refcnt
))
700 if (nlk
->cb_running
&& nlk
->cb
.done
) {
701 INIT_WORK(&nlk
->work
, netlink_sock_destruct_work
);
702 schedule_work(&nlk
->work
);
709 static int netlink_release(struct socket
*sock
)
711 struct sock
*sk
= sock
->sk
;
712 struct netlink_sock
*nlk
;
722 * OK. Socket is unlinked, any packets that arrive now
726 /* must not acquire netlink_table_lock in any way again before unbind
727 * and notifying genetlink is done as otherwise it might deadlock
729 if (nlk
->netlink_unbind
) {
732 for (i
= 0; i
< nlk
->ngroups
; i
++)
733 if (test_bit(i
, nlk
->groups
))
734 nlk
->netlink_unbind(sock_net(sk
), i
+ 1);
736 if (sk
->sk_protocol
== NETLINK_GENERIC
&&
737 atomic_dec_return(&genl_sk_destructing_cnt
) == 0)
738 wake_up(&genl_sk_destructing_waitq
);
741 wake_up_interruptible_all(&nlk
->wait
);
743 skb_queue_purge(&sk
->sk_write_queue
);
745 if (nlk
->portid
&& nlk
->bound
) {
746 struct netlink_notify n
= {
748 .protocol
= sk
->sk_protocol
,
749 .portid
= nlk
->portid
,
751 blocking_notifier_call_chain(&netlink_chain
,
752 NETLINK_URELEASE
, &n
);
755 module_put(nlk
->module
);
757 if (netlink_is_kernel(sk
)) {
758 netlink_table_grab();
759 BUG_ON(nl_table
[sk
->sk_protocol
].registered
== 0);
760 if (--nl_table
[sk
->sk_protocol
].registered
== 0) {
761 struct listeners
*old
;
763 old
= nl_deref_protected(nl_table
[sk
->sk_protocol
].listeners
);
764 RCU_INIT_POINTER(nl_table
[sk
->sk_protocol
].listeners
, NULL
);
766 nl_table
[sk
->sk_protocol
].module
= NULL
;
767 nl_table
[sk
->sk_protocol
].bind
= NULL
;
768 nl_table
[sk
->sk_protocol
].unbind
= NULL
;
769 nl_table
[sk
->sk_protocol
].flags
= 0;
770 nl_table
[sk
->sk_protocol
].registered
= 0;
772 netlink_table_ungrab();
776 sock_prot_inuse_add(sock_net(sk
), &netlink_proto
, -1);
778 call_rcu(&nlk
->rcu
, deferred_put_nlk_sk
);
782 static int netlink_autobind(struct socket
*sock
)
784 struct sock
*sk
= sock
->sk
;
785 struct net
*net
= sock_net(sk
);
786 struct netlink_table
*table
= &nl_table
[sk
->sk_protocol
];
787 s32 portid
= task_tgid_vnr(current
);
795 ok
= !__netlink_lookup(table
, portid
, net
);
798 /* Bind collision, search negative portid values. */
800 /* rover will be in range [S32_MIN, -4097] */
801 rover
= S32_MIN
+ prandom_u32_max(-4096 - S32_MIN
);
802 else if (rover
>= -4096)
808 err
= netlink_insert(sk
, portid
);
809 if (err
== -EADDRINUSE
)
812 /* If 2 threads race to autobind, that is fine. */
820 * __netlink_ns_capable - General netlink message capability test
821 * @nsp: NETLINK_CB of the socket buffer holding a netlink command from userspace.
822 * @user_ns: The user namespace of the capability to use
823 * @cap: The capability to use
825 * Test to see if the opener of the socket we received the message
826 * from had when the netlink socket was created and the sender of the
827 * message has has the capability @cap in the user namespace @user_ns.
829 bool __netlink_ns_capable(const struct netlink_skb_parms
*nsp
,
830 struct user_namespace
*user_ns
, int cap
)
832 return ((nsp
->flags
& NETLINK_SKB_DST
) ||
833 file_ns_capable(nsp
->sk
->sk_socket
->file
, user_ns
, cap
)) &&
834 ns_capable(user_ns
, cap
);
836 EXPORT_SYMBOL(__netlink_ns_capable
);
839 * netlink_ns_capable - General netlink message capability test
840 * @skb: socket buffer holding a netlink command from userspace
841 * @user_ns: The user namespace of the capability to use
842 * @cap: The capability to use
844 * Test to see if the opener of the socket we received the message
845 * from had when the netlink socket was created and the sender of the
846 * message has has the capability @cap in the user namespace @user_ns.
848 bool netlink_ns_capable(const struct sk_buff
*skb
,
849 struct user_namespace
*user_ns
, int cap
)
851 return __netlink_ns_capable(&NETLINK_CB(skb
), user_ns
, cap
);
853 EXPORT_SYMBOL(netlink_ns_capable
);
856 * netlink_capable - Netlink global message capability test
857 * @skb: socket buffer holding a netlink command from userspace
858 * @cap: The capability to use
860 * Test to see if the opener of the socket we received the message
861 * from had when the netlink socket was created and the sender of the
862 * message has has the capability @cap in all user namespaces.
864 bool netlink_capable(const struct sk_buff
*skb
, int cap
)
866 return netlink_ns_capable(skb
, &init_user_ns
, cap
);
868 EXPORT_SYMBOL(netlink_capable
);
871 * netlink_net_capable - Netlink network namespace message capability test
872 * @skb: socket buffer holding a netlink command from userspace
873 * @cap: The capability to use
875 * Test to see if the opener of the socket we received the message
876 * from had when the netlink socket was created and the sender of the
877 * message has has the capability @cap over the network namespace of
878 * the socket we received the message from.
880 bool netlink_net_capable(const struct sk_buff
*skb
, int cap
)
882 return netlink_ns_capable(skb
, sock_net(skb
->sk
)->user_ns
, cap
);
884 EXPORT_SYMBOL(netlink_net_capable
);
886 static inline int netlink_allowed(const struct socket
*sock
, unsigned int flag
)
888 return (nl_table
[sock
->sk
->sk_protocol
].flags
& flag
) ||
889 ns_capable(sock_net(sock
->sk
)->user_ns
, CAP_NET_ADMIN
);
893 netlink_update_subscriptions(struct sock
*sk
, unsigned int subscriptions
)
895 struct netlink_sock
*nlk
= nlk_sk(sk
);
897 if (nlk
->subscriptions
&& !subscriptions
)
898 __sk_del_bind_node(sk
);
899 else if (!nlk
->subscriptions
&& subscriptions
)
900 sk_add_bind_node(sk
, &nl_table
[sk
->sk_protocol
].mc_list
);
901 nlk
->subscriptions
= subscriptions
;
904 static int netlink_realloc_groups(struct sock
*sk
)
906 struct netlink_sock
*nlk
= nlk_sk(sk
);
908 unsigned long *new_groups
;
911 netlink_table_grab();
913 groups
= nl_table
[sk
->sk_protocol
].groups
;
914 if (!nl_table
[sk
->sk_protocol
].registered
) {
919 if (nlk
->ngroups
>= groups
)
922 new_groups
= krealloc(nlk
->groups
, NLGRPSZ(groups
), GFP_ATOMIC
);
923 if (new_groups
== NULL
) {
927 memset((char *)new_groups
+ NLGRPSZ(nlk
->ngroups
), 0,
928 NLGRPSZ(groups
) - NLGRPSZ(nlk
->ngroups
));
930 nlk
->groups
= new_groups
;
931 nlk
->ngroups
= groups
;
933 netlink_table_ungrab();
937 static void netlink_undo_bind(int group
, long unsigned int groups
,
940 struct netlink_sock
*nlk
= nlk_sk(sk
);
943 if (!nlk
->netlink_unbind
)
946 for (undo
= 0; undo
< group
; undo
++)
947 if (test_bit(undo
, &groups
))
948 nlk
->netlink_unbind(sock_net(sk
), undo
+ 1);
951 static int netlink_bind(struct socket
*sock
, struct sockaddr
*addr
,
954 struct sock
*sk
= sock
->sk
;
955 struct net
*net
= sock_net(sk
);
956 struct netlink_sock
*nlk
= nlk_sk(sk
);
957 struct sockaddr_nl
*nladdr
= (struct sockaddr_nl
*)addr
;
959 long unsigned int groups
= nladdr
->nl_groups
;
962 if (addr_len
< sizeof(struct sockaddr_nl
))
965 if (nladdr
->nl_family
!= AF_NETLINK
)
968 /* Only superuser is allowed to listen multicasts */
970 if (!netlink_allowed(sock
, NL_CFG_F_NONROOT_RECV
))
972 err
= netlink_realloc_groups(sk
);
979 /* Ensure nlk->portid is up-to-date. */
982 if (nladdr
->nl_pid
!= nlk
->portid
)
986 netlink_lock_table();
987 if (nlk
->netlink_bind
&& groups
) {
990 for (group
= 0; group
< nlk
->ngroups
; group
++) {
991 if (!test_bit(group
, &groups
))
993 err
= nlk
->netlink_bind(net
, group
+ 1);
996 netlink_undo_bind(group
, groups
, sk
);
1001 /* No need for barriers here as we return to user-space without
1002 * using any of the bound attributes.
1005 err
= nladdr
->nl_pid
?
1006 netlink_insert(sk
, nladdr
->nl_pid
) :
1007 netlink_autobind(sock
);
1009 netlink_undo_bind(nlk
->ngroups
, groups
, sk
);
1014 if (!groups
&& (nlk
->groups
== NULL
|| !(u32
)nlk
->groups
[0]))
1016 netlink_unlock_table();
1018 netlink_table_grab();
1019 netlink_update_subscriptions(sk
, nlk
->subscriptions
+
1021 hweight32(nlk
->groups
[0]));
1022 nlk
->groups
[0] = (nlk
->groups
[0] & ~0xffffffffUL
) | groups
;
1023 netlink_update_listeners(sk
);
1024 netlink_table_ungrab();
1029 netlink_unlock_table();
1033 static int netlink_connect(struct socket
*sock
, struct sockaddr
*addr
,
1034 int alen
, int flags
)
1037 struct sock
*sk
= sock
->sk
;
1038 struct netlink_sock
*nlk
= nlk_sk(sk
);
1039 struct sockaddr_nl
*nladdr
= (struct sockaddr_nl
*)addr
;
1041 if (alen
< sizeof(addr
->sa_family
))
1044 if (addr
->sa_family
== AF_UNSPEC
) {
1045 sk
->sk_state
= NETLINK_UNCONNECTED
;
1046 nlk
->dst_portid
= 0;
1050 if (addr
->sa_family
!= AF_NETLINK
)
1053 if ((nladdr
->nl_groups
|| nladdr
->nl_pid
) &&
1054 !netlink_allowed(sock
, NL_CFG_F_NONROOT_SEND
))
1057 /* No need for barriers here as we return to user-space without
1058 * using any of the bound attributes.
1061 err
= netlink_autobind(sock
);
1064 sk
->sk_state
= NETLINK_CONNECTED
;
1065 nlk
->dst_portid
= nladdr
->nl_pid
;
1066 nlk
->dst_group
= ffs(nladdr
->nl_groups
);
1072 static int netlink_getname(struct socket
*sock
, struct sockaddr
*addr
,
1073 int *addr_len
, int peer
)
1075 struct sock
*sk
= sock
->sk
;
1076 struct netlink_sock
*nlk
= nlk_sk(sk
);
1077 DECLARE_SOCKADDR(struct sockaddr_nl
*, nladdr
, addr
);
1079 nladdr
->nl_family
= AF_NETLINK
;
1081 *addr_len
= sizeof(*nladdr
);
1084 nladdr
->nl_pid
= nlk
->dst_portid
;
1085 nladdr
->nl_groups
= netlink_group_mask(nlk
->dst_group
);
1087 nladdr
->nl_pid
= nlk
->portid
;
1088 netlink_lock_table();
1089 nladdr
->nl_groups
= nlk
->groups
? nlk
->groups
[0] : 0;
1090 netlink_unlock_table();
1095 static int netlink_ioctl(struct socket
*sock
, unsigned int cmd
,
1098 /* try to hand this ioctl down to the NIC drivers.
1100 return -ENOIOCTLCMD
;
1103 static struct sock
*netlink_getsockbyportid(struct sock
*ssk
, u32 portid
)
1106 struct netlink_sock
*nlk
;
1108 sock
= netlink_lookup(sock_net(ssk
), ssk
->sk_protocol
, portid
);
1110 return ERR_PTR(-ECONNREFUSED
);
1112 /* Don't bother queuing skb if kernel socket has no input function */
1114 if (sock
->sk_state
== NETLINK_CONNECTED
&&
1115 nlk
->dst_portid
!= nlk_sk(ssk
)->portid
) {
1117 return ERR_PTR(-ECONNREFUSED
);
1122 struct sock
*netlink_getsockbyfilp(struct file
*filp
)
1124 struct inode
*inode
= file_inode(filp
);
1127 if (!S_ISSOCK(inode
->i_mode
))
1128 return ERR_PTR(-ENOTSOCK
);
1130 sock
= SOCKET_I(inode
)->sk
;
1131 if (sock
->sk_family
!= AF_NETLINK
)
1132 return ERR_PTR(-EINVAL
);
1138 static struct sk_buff
*netlink_alloc_large_skb(unsigned int size
,
1141 struct sk_buff
*skb
;
1144 if (size
<= NLMSG_GOODSIZE
|| broadcast
)
1145 return alloc_skb(size
, GFP_KERNEL
);
1147 size
= SKB_DATA_ALIGN(size
) +
1148 SKB_DATA_ALIGN(sizeof(struct skb_shared_info
));
1150 data
= vmalloc(size
);
1154 skb
= __build_skb(data
, size
);
1158 skb
->destructor
= netlink_skb_destructor
;
1164 * Attach a skb to a netlink socket.
1165 * The caller must hold a reference to the destination socket. On error, the
1166 * reference is dropped. The skb is not send to the destination, just all
1167 * all error checks are performed and memory in the queue is reserved.
1169 * < 0: error. skb freed, reference to sock dropped.
1171 * 1: repeat lookup - reference dropped while waiting for socket memory.
1173 int netlink_attachskb(struct sock
*sk
, struct sk_buff
*skb
,
1174 long *timeo
, struct sock
*ssk
)
1176 struct netlink_sock
*nlk
;
1180 if ((atomic_read(&sk
->sk_rmem_alloc
) > sk
->sk_rcvbuf
||
1181 test_bit(NETLINK_S_CONGESTED
, &nlk
->state
))) {
1182 DECLARE_WAITQUEUE(wait
, current
);
1184 if (!ssk
|| netlink_is_kernel(ssk
))
1185 netlink_overrun(sk
);
1191 __set_current_state(TASK_INTERRUPTIBLE
);
1192 add_wait_queue(&nlk
->wait
, &wait
);
1194 if ((atomic_read(&sk
->sk_rmem_alloc
) > sk
->sk_rcvbuf
||
1195 test_bit(NETLINK_S_CONGESTED
, &nlk
->state
)) &&
1196 !sock_flag(sk
, SOCK_DEAD
))
1197 *timeo
= schedule_timeout(*timeo
);
1199 __set_current_state(TASK_RUNNING
);
1200 remove_wait_queue(&nlk
->wait
, &wait
);
1203 if (signal_pending(current
)) {
1205 return sock_intr_errno(*timeo
);
1209 netlink_skb_set_owner_r(skb
, sk
);
1213 static int __netlink_sendskb(struct sock
*sk
, struct sk_buff
*skb
)
1217 netlink_deliver_tap(skb
);
1219 skb_queue_tail(&sk
->sk_receive_queue
, skb
);
1220 sk
->sk_data_ready(sk
);
1224 int netlink_sendskb(struct sock
*sk
, struct sk_buff
*skb
)
1226 int len
= __netlink_sendskb(sk
, skb
);
1232 void netlink_detachskb(struct sock
*sk
, struct sk_buff
*skb
)
1238 static struct sk_buff
*netlink_trim(struct sk_buff
*skb
, gfp_t allocation
)
1242 WARN_ON(skb
->sk
!= NULL
);
1243 delta
= skb
->end
- skb
->tail
;
1244 if (is_vmalloc_addr(skb
->head
) || delta
* 2 < skb
->truesize
)
1247 if (skb_shared(skb
)) {
1248 struct sk_buff
*nskb
= skb_clone(skb
, allocation
);
1255 pskb_expand_head(skb
, 0, -delta
,
1256 (allocation
& ~__GFP_DIRECT_RECLAIM
) |
1257 __GFP_NOWARN
| __GFP_NORETRY
);
1261 static int netlink_unicast_kernel(struct sock
*sk
, struct sk_buff
*skb
,
1265 struct netlink_sock
*nlk
= nlk_sk(sk
);
1267 ret
= -ECONNREFUSED
;
1268 if (nlk
->netlink_rcv
!= NULL
) {
1270 netlink_skb_set_owner_r(skb
, sk
);
1271 NETLINK_CB(skb
).sk
= ssk
;
1272 netlink_deliver_tap_kernel(sk
, ssk
, skb
);
1273 nlk
->netlink_rcv(skb
);
1282 int netlink_unicast(struct sock
*ssk
, struct sk_buff
*skb
,
1283 u32 portid
, int nonblock
)
1289 skb
= netlink_trim(skb
, gfp_any());
1291 timeo
= sock_sndtimeo(ssk
, nonblock
);
1293 sk
= netlink_getsockbyportid(ssk
, portid
);
1298 if (netlink_is_kernel(sk
))
1299 return netlink_unicast_kernel(sk
, skb
, ssk
);
1301 if (sk_filter(sk
, skb
)) {
1308 err
= netlink_attachskb(sk
, skb
, &timeo
, ssk
);
1314 return netlink_sendskb(sk
, skb
);
1316 EXPORT_SYMBOL(netlink_unicast
);
1318 int netlink_has_listeners(struct sock
*sk
, unsigned int group
)
1321 struct listeners
*listeners
;
1323 BUG_ON(!netlink_is_kernel(sk
));
1326 listeners
= rcu_dereference(nl_table
[sk
->sk_protocol
].listeners
);
1328 if (listeners
&& group
- 1 < nl_table
[sk
->sk_protocol
].groups
)
1329 res
= test_bit(group
- 1, listeners
->masks
);
1335 EXPORT_SYMBOL_GPL(netlink_has_listeners
);
1337 static int netlink_broadcast_deliver(struct sock
*sk
, struct sk_buff
*skb
)
1339 struct netlink_sock
*nlk
= nlk_sk(sk
);
1341 if (atomic_read(&sk
->sk_rmem_alloc
) <= sk
->sk_rcvbuf
&&
1342 !test_bit(NETLINK_S_CONGESTED
, &nlk
->state
)) {
1343 netlink_skb_set_owner_r(skb
, sk
);
1344 __netlink_sendskb(sk
, skb
);
1345 return atomic_read(&sk
->sk_rmem_alloc
) > (sk
->sk_rcvbuf
>> 1);
1350 struct netlink_broadcast_data
{
1351 struct sock
*exclude_sk
;
1356 int delivery_failure
;
1360 struct sk_buff
*skb
, *skb2
;
1361 int (*tx_filter
)(struct sock
*dsk
, struct sk_buff
*skb
, void *data
);
1365 static void do_one_broadcast(struct sock
*sk
,
1366 struct netlink_broadcast_data
*p
)
1368 struct netlink_sock
*nlk
= nlk_sk(sk
);
1371 if (p
->exclude_sk
== sk
)
1374 if (nlk
->portid
== p
->portid
|| p
->group
- 1 >= nlk
->ngroups
||
1375 !test_bit(p
->group
- 1, nlk
->groups
))
1378 if (!net_eq(sock_net(sk
), p
->net
)) {
1379 if (!(nlk
->flags
& NETLINK_F_LISTEN_ALL_NSID
))
1382 if (!peernet_has_id(sock_net(sk
), p
->net
))
1385 if (!file_ns_capable(sk
->sk_socket
->file
, p
->net
->user_ns
,
1391 netlink_overrun(sk
);
1396 if (p
->skb2
== NULL
) {
1397 if (skb_shared(p
->skb
)) {
1398 p
->skb2
= skb_clone(p
->skb
, p
->allocation
);
1400 p
->skb2
= skb_get(p
->skb
);
1402 * skb ownership may have been set when
1403 * delivered to a previous socket.
1405 skb_orphan(p
->skb2
);
1408 if (p
->skb2
== NULL
) {
1409 netlink_overrun(sk
);
1410 /* Clone failed. Notify ALL listeners. */
1412 if (nlk
->flags
& NETLINK_F_BROADCAST_SEND_ERROR
)
1413 p
->delivery_failure
= 1;
1416 if (p
->tx_filter
&& p
->tx_filter(sk
, p
->skb2
, p
->tx_data
)) {
1421 if (sk_filter(sk
, p
->skb2
)) {
1426 NETLINK_CB(p
->skb2
).nsid
= peernet2id(sock_net(sk
), p
->net
);
1427 if (NETLINK_CB(p
->skb2
).nsid
!= NETNSA_NSID_NOT_ASSIGNED
)
1428 NETLINK_CB(p
->skb2
).nsid_is_set
= true;
1429 val
= netlink_broadcast_deliver(sk
, p
->skb2
);
1431 netlink_overrun(sk
);
1432 if (nlk
->flags
& NETLINK_F_BROADCAST_SEND_ERROR
)
1433 p
->delivery_failure
= 1;
1435 p
->congested
|= val
;
1443 int netlink_broadcast_filtered(struct sock
*ssk
, struct sk_buff
*skb
, u32 portid
,
1444 u32 group
, gfp_t allocation
,
1445 int (*filter
)(struct sock
*dsk
, struct sk_buff
*skb
, void *data
),
1448 struct net
*net
= sock_net(ssk
);
1449 struct netlink_broadcast_data info
;
1452 skb
= netlink_trim(skb
, allocation
);
1454 info
.exclude_sk
= ssk
;
1456 info
.portid
= portid
;
1459 info
.delivery_failure
= 0;
1462 info
.allocation
= allocation
;
1465 info
.tx_filter
= filter
;
1466 info
.tx_data
= filter_data
;
1468 /* While we sleep in clone, do not allow to change socket list */
1470 netlink_lock_table();
1472 sk_for_each_bound(sk
, &nl_table
[ssk
->sk_protocol
].mc_list
)
1473 do_one_broadcast(sk
, &info
);
1477 netlink_unlock_table();
1479 if (info
.delivery_failure
) {
1480 kfree_skb(info
.skb2
);
1483 consume_skb(info
.skb2
);
1485 if (info
.delivered
) {
1486 if (info
.congested
&& gfpflags_allow_blocking(allocation
))
1492 EXPORT_SYMBOL(netlink_broadcast_filtered
);
1494 int netlink_broadcast(struct sock
*ssk
, struct sk_buff
*skb
, u32 portid
,
1495 u32 group
, gfp_t allocation
)
1497 return netlink_broadcast_filtered(ssk
, skb
, portid
, group
, allocation
,
1500 EXPORT_SYMBOL(netlink_broadcast
);
1502 struct netlink_set_err_data
{
1503 struct sock
*exclude_sk
;
1509 static int do_one_set_err(struct sock
*sk
, struct netlink_set_err_data
*p
)
1511 struct netlink_sock
*nlk
= nlk_sk(sk
);
1514 if (sk
== p
->exclude_sk
)
1517 if (!net_eq(sock_net(sk
), sock_net(p
->exclude_sk
)))
1520 if (nlk
->portid
== p
->portid
|| p
->group
- 1 >= nlk
->ngroups
||
1521 !test_bit(p
->group
- 1, nlk
->groups
))
1524 if (p
->code
== ENOBUFS
&& nlk
->flags
& NETLINK_F_RECV_NO_ENOBUFS
) {
1529 sk
->sk_err
= p
->code
;
1530 sk
->sk_error_report(sk
);
1536 * netlink_set_err - report error to broadcast listeners
1537 * @ssk: the kernel netlink socket, as returned by netlink_kernel_create()
1538 * @portid: the PORTID of a process that we want to skip (if any)
1539 * @group: the broadcast group that will notice the error
1540 * @code: error code, must be negative (as usual in kernelspace)
1542 * This function returns the number of broadcast listeners that have set the
1543 * NETLINK_NO_ENOBUFS socket option.
1545 int netlink_set_err(struct sock
*ssk
, u32 portid
, u32 group
, int code
)
1547 struct netlink_set_err_data info
;
1551 info
.exclude_sk
= ssk
;
1552 info
.portid
= portid
;
1554 /* sk->sk_err wants a positive error value */
1557 read_lock(&nl_table_lock
);
1559 sk_for_each_bound(sk
, &nl_table
[ssk
->sk_protocol
].mc_list
)
1560 ret
+= do_one_set_err(sk
, &info
);
1562 read_unlock(&nl_table_lock
);
1565 EXPORT_SYMBOL(netlink_set_err
);
1567 /* must be called with netlink table grabbed */
1568 static void netlink_update_socket_mc(struct netlink_sock
*nlk
,
1572 int old
, new = !!is_new
, subscriptions
;
1574 old
= test_bit(group
- 1, nlk
->groups
);
1575 subscriptions
= nlk
->subscriptions
- old
+ new;
1577 __set_bit(group
- 1, nlk
->groups
);
1579 __clear_bit(group
- 1, nlk
->groups
);
1580 netlink_update_subscriptions(&nlk
->sk
, subscriptions
);
1581 netlink_update_listeners(&nlk
->sk
);
1584 static int netlink_setsockopt(struct socket
*sock
, int level
, int optname
,
1585 char __user
*optval
, unsigned int optlen
)
1587 struct sock
*sk
= sock
->sk
;
1588 struct netlink_sock
*nlk
= nlk_sk(sk
);
1589 unsigned int val
= 0;
1592 if (level
!= SOL_NETLINK
)
1593 return -ENOPROTOOPT
;
1595 if (optlen
>= sizeof(int) &&
1596 get_user(val
, (unsigned int __user
*)optval
))
1600 case NETLINK_PKTINFO
:
1602 nlk
->flags
|= NETLINK_F_RECV_PKTINFO
;
1604 nlk
->flags
&= ~NETLINK_F_RECV_PKTINFO
;
1607 case NETLINK_ADD_MEMBERSHIP
:
1608 case NETLINK_DROP_MEMBERSHIP
: {
1609 if (!netlink_allowed(sock
, NL_CFG_F_NONROOT_RECV
))
1611 err
= netlink_realloc_groups(sk
);
1614 if (!val
|| val
- 1 >= nlk
->ngroups
)
1616 if (optname
== NETLINK_ADD_MEMBERSHIP
&& nlk
->netlink_bind
) {
1617 err
= nlk
->netlink_bind(sock_net(sk
), val
);
1621 netlink_table_grab();
1622 netlink_update_socket_mc(nlk
, val
,
1623 optname
== NETLINK_ADD_MEMBERSHIP
);
1624 netlink_table_ungrab();
1625 if (optname
== NETLINK_DROP_MEMBERSHIP
&& nlk
->netlink_unbind
)
1626 nlk
->netlink_unbind(sock_net(sk
), val
);
1631 case NETLINK_BROADCAST_ERROR
:
1633 nlk
->flags
|= NETLINK_F_BROADCAST_SEND_ERROR
;
1635 nlk
->flags
&= ~NETLINK_F_BROADCAST_SEND_ERROR
;
1638 case NETLINK_NO_ENOBUFS
:
1640 nlk
->flags
|= NETLINK_F_RECV_NO_ENOBUFS
;
1641 clear_bit(NETLINK_S_CONGESTED
, &nlk
->state
);
1642 wake_up_interruptible(&nlk
->wait
);
1644 nlk
->flags
&= ~NETLINK_F_RECV_NO_ENOBUFS
;
1648 case NETLINK_LISTEN_ALL_NSID
:
1649 if (!ns_capable(sock_net(sk
)->user_ns
, CAP_NET_BROADCAST
))
1653 nlk
->flags
|= NETLINK_F_LISTEN_ALL_NSID
;
1655 nlk
->flags
&= ~NETLINK_F_LISTEN_ALL_NSID
;
1658 case NETLINK_CAP_ACK
:
1660 nlk
->flags
|= NETLINK_F_CAP_ACK
;
1662 nlk
->flags
&= ~NETLINK_F_CAP_ACK
;
1665 case NETLINK_EXT_ACK
:
1667 nlk
->flags
|= NETLINK_F_EXT_ACK
;
1669 nlk
->flags
&= ~NETLINK_F_EXT_ACK
;
1678 static int netlink_getsockopt(struct socket
*sock
, int level
, int optname
,
1679 char __user
*optval
, int __user
*optlen
)
1681 struct sock
*sk
= sock
->sk
;
1682 struct netlink_sock
*nlk
= nlk_sk(sk
);
1685 if (level
!= SOL_NETLINK
)
1686 return -ENOPROTOOPT
;
1688 if (get_user(len
, optlen
))
1694 case NETLINK_PKTINFO
:
1695 if (len
< sizeof(int))
1698 val
= nlk
->flags
& NETLINK_F_RECV_PKTINFO
? 1 : 0;
1699 if (put_user(len
, optlen
) ||
1700 put_user(val
, optval
))
1704 case NETLINK_BROADCAST_ERROR
:
1705 if (len
< sizeof(int))
1708 val
= nlk
->flags
& NETLINK_F_BROADCAST_SEND_ERROR
? 1 : 0;
1709 if (put_user(len
, optlen
) ||
1710 put_user(val
, optval
))
1714 case NETLINK_NO_ENOBUFS
:
1715 if (len
< sizeof(int))
1718 val
= nlk
->flags
& NETLINK_F_RECV_NO_ENOBUFS
? 1 : 0;
1719 if (put_user(len
, optlen
) ||
1720 put_user(val
, optval
))
1724 case NETLINK_LIST_MEMBERSHIPS
: {
1725 int pos
, idx
, shift
;
1728 netlink_lock_table();
1729 for (pos
= 0; pos
* 8 < nlk
->ngroups
; pos
+= sizeof(u32
)) {
1730 if (len
- pos
< sizeof(u32
))
1733 idx
= pos
/ sizeof(unsigned long);
1734 shift
= (pos
% sizeof(unsigned long)) * 8;
1735 if (put_user((u32
)(nlk
->groups
[idx
] >> shift
),
1736 (u32 __user
*)(optval
+ pos
))) {
1741 if (put_user(ALIGN(nlk
->ngroups
/ 8, sizeof(u32
)), optlen
))
1743 netlink_unlock_table();
1746 case NETLINK_CAP_ACK
:
1747 if (len
< sizeof(int))
1750 val
= nlk
->flags
& NETLINK_F_CAP_ACK
? 1 : 0;
1751 if (put_user(len
, optlen
) ||
1752 put_user(val
, optval
))
1756 case NETLINK_EXT_ACK
:
1757 if (len
< sizeof(int))
1760 val
= nlk
->flags
& NETLINK_F_EXT_ACK
? 1 : 0;
1761 if (put_user(len
, optlen
) || put_user(val
, optval
))
1771 static void netlink_cmsg_recv_pktinfo(struct msghdr
*msg
, struct sk_buff
*skb
)
1773 struct nl_pktinfo info
;
1775 info
.group
= NETLINK_CB(skb
).dst_group
;
1776 put_cmsg(msg
, SOL_NETLINK
, NETLINK_PKTINFO
, sizeof(info
), &info
);
1779 static void netlink_cmsg_listen_all_nsid(struct sock
*sk
, struct msghdr
*msg
,
1780 struct sk_buff
*skb
)
1782 if (!NETLINK_CB(skb
).nsid_is_set
)
1785 put_cmsg(msg
, SOL_NETLINK
, NETLINK_LISTEN_ALL_NSID
, sizeof(int),
1786 &NETLINK_CB(skb
).nsid
);
1789 static int netlink_sendmsg(struct socket
*sock
, struct msghdr
*msg
, size_t len
)
1791 struct sock
*sk
= sock
->sk
;
1792 struct netlink_sock
*nlk
= nlk_sk(sk
);
1793 DECLARE_SOCKADDR(struct sockaddr_nl
*, addr
, msg
->msg_name
);
1796 struct sk_buff
*skb
;
1798 struct scm_cookie scm
;
1799 u32 netlink_skb_flags
= 0;
1801 if (msg
->msg_flags
&MSG_OOB
)
1804 err
= scm_send(sock
, msg
, &scm
, true);
1808 if (msg
->msg_namelen
) {
1810 if (addr
->nl_family
!= AF_NETLINK
)
1812 dst_portid
= addr
->nl_pid
;
1813 dst_group
= ffs(addr
->nl_groups
);
1815 if ((dst_group
|| dst_portid
) &&
1816 !netlink_allowed(sock
, NL_CFG_F_NONROOT_SEND
))
1818 netlink_skb_flags
|= NETLINK_SKB_DST
;
1820 dst_portid
= nlk
->dst_portid
;
1821 dst_group
= nlk
->dst_group
;
1825 err
= netlink_autobind(sock
);
1829 /* Ensure nlk is hashed and visible. */
1834 if (len
> sk
->sk_sndbuf
- 32)
1837 skb
= netlink_alloc_large_skb(len
, dst_group
);
1841 NETLINK_CB(skb
).portid
= nlk
->portid
;
1842 NETLINK_CB(skb
).dst_group
= dst_group
;
1843 NETLINK_CB(skb
).creds
= scm
.creds
;
1844 NETLINK_CB(skb
).flags
= netlink_skb_flags
;
1847 if (memcpy_from_msg(skb_put(skb
, len
), msg
, len
)) {
1852 err
= security_netlink_send(sk
, skb
);
1859 refcount_inc(&skb
->users
);
1860 netlink_broadcast(sk
, skb
, dst_portid
, dst_group
, GFP_KERNEL
);
1862 err
= netlink_unicast(sk
, skb
, dst_portid
, msg
->msg_flags
&MSG_DONTWAIT
);
1869 static int netlink_recvmsg(struct socket
*sock
, struct msghdr
*msg
, size_t len
,
1872 struct scm_cookie scm
;
1873 struct sock
*sk
= sock
->sk
;
1874 struct netlink_sock
*nlk
= nlk_sk(sk
);
1875 int noblock
= flags
&MSG_DONTWAIT
;
1877 struct sk_buff
*skb
, *data_skb
;
1885 skb
= skb_recv_datagram(sk
, flags
, noblock
, &err
);
1891 #ifdef CONFIG_COMPAT_NETLINK_MESSAGES
1892 if (unlikely(skb_shinfo(skb
)->frag_list
)) {
1894 * If this skb has a frag_list, then here that means that we
1895 * will have to use the frag_list skb's data for compat tasks
1896 * and the regular skb's data for normal (non-compat) tasks.
1898 * If we need to send the compat skb, assign it to the
1899 * 'data_skb' variable so that it will be used below for data
1900 * copying. We keep 'skb' for everything else, including
1901 * freeing both later.
1903 if (flags
& MSG_CMSG_COMPAT
)
1904 data_skb
= skb_shinfo(skb
)->frag_list
;
1908 /* Record the max length of recvmsg() calls for future allocations */
1909 nlk
->max_recvmsg_len
= max(nlk
->max_recvmsg_len
, len
);
1910 nlk
->max_recvmsg_len
= min_t(size_t, nlk
->max_recvmsg_len
,
1911 SKB_WITH_OVERHEAD(32768));
1913 copied
= data_skb
->len
;
1915 msg
->msg_flags
|= MSG_TRUNC
;
1919 skb_reset_transport_header(data_skb
);
1920 err
= skb_copy_datagram_msg(data_skb
, 0, msg
, copied
);
1922 if (msg
->msg_name
) {
1923 DECLARE_SOCKADDR(struct sockaddr_nl
*, addr
, msg
->msg_name
);
1924 addr
->nl_family
= AF_NETLINK
;
1926 addr
->nl_pid
= NETLINK_CB(skb
).portid
;
1927 addr
->nl_groups
= netlink_group_mask(NETLINK_CB(skb
).dst_group
);
1928 msg
->msg_namelen
= sizeof(*addr
);
1931 if (nlk
->flags
& NETLINK_F_RECV_PKTINFO
)
1932 netlink_cmsg_recv_pktinfo(msg
, skb
);
1933 if (nlk
->flags
& NETLINK_F_LISTEN_ALL_NSID
)
1934 netlink_cmsg_listen_all_nsid(sk
, msg
, skb
);
1936 memset(&scm
, 0, sizeof(scm
));
1937 scm
.creds
= *NETLINK_CREDS(skb
);
1938 if (flags
& MSG_TRUNC
)
1939 copied
= data_skb
->len
;
1941 skb_free_datagram(sk
, skb
);
1943 if (nlk
->cb_running
&&
1944 atomic_read(&sk
->sk_rmem_alloc
) <= sk
->sk_rcvbuf
/ 2) {
1945 ret
= netlink_dump(sk
);
1948 sk
->sk_error_report(sk
);
1952 scm_recv(sock
, msg
, &scm
, flags
);
1954 netlink_rcv_wake(sk
);
1955 return err
? : copied
;
1958 static void netlink_data_ready(struct sock
*sk
)
1964 * We export these functions to other modules. They provide a
1965 * complete set of kernel non-blocking support for message
1970 __netlink_kernel_create(struct net
*net
, int unit
, struct module
*module
,
1971 struct netlink_kernel_cfg
*cfg
)
1973 struct socket
*sock
;
1975 struct netlink_sock
*nlk
;
1976 struct listeners
*listeners
= NULL
;
1977 struct mutex
*cb_mutex
= cfg
? cfg
->cb_mutex
: NULL
;
1978 unsigned int groups
;
1982 if (unit
< 0 || unit
>= MAX_LINKS
)
1985 if (sock_create_lite(PF_NETLINK
, SOCK_DGRAM
, unit
, &sock
))
1988 if (__netlink_create(net
, sock
, cb_mutex
, unit
, 1) < 0)
1989 goto out_sock_release_nosk
;
1993 if (!cfg
|| cfg
->groups
< 32)
1996 groups
= cfg
->groups
;
1998 listeners
= kzalloc(sizeof(*listeners
) + NLGRPSZ(groups
), GFP_KERNEL
);
2000 goto out_sock_release
;
2002 sk
->sk_data_ready
= netlink_data_ready
;
2003 if (cfg
&& cfg
->input
)
2004 nlk_sk(sk
)->netlink_rcv
= cfg
->input
;
2006 if (netlink_insert(sk
, 0))
2007 goto out_sock_release
;
2010 nlk
->flags
|= NETLINK_F_KERNEL_SOCKET
;
2012 netlink_table_grab();
2013 if (!nl_table
[unit
].registered
) {
2014 nl_table
[unit
].groups
= groups
;
2015 rcu_assign_pointer(nl_table
[unit
].listeners
, listeners
);
2016 nl_table
[unit
].cb_mutex
= cb_mutex
;
2017 nl_table
[unit
].module
= module
;
2019 nl_table
[unit
].bind
= cfg
->bind
;
2020 nl_table
[unit
].unbind
= cfg
->unbind
;
2021 nl_table
[unit
].flags
= cfg
->flags
;
2023 nl_table
[unit
].compare
= cfg
->compare
;
2025 nl_table
[unit
].registered
= 1;
2028 nl_table
[unit
].registered
++;
2030 netlink_table_ungrab();
2035 netlink_kernel_release(sk
);
2038 out_sock_release_nosk
:
2042 EXPORT_SYMBOL(__netlink_kernel_create
);
2045 netlink_kernel_release(struct sock
*sk
)
2047 if (sk
== NULL
|| sk
->sk_socket
== NULL
)
2050 sock_release(sk
->sk_socket
);
2052 EXPORT_SYMBOL(netlink_kernel_release
);
2054 int __netlink_change_ngroups(struct sock
*sk
, unsigned int groups
)
2056 struct listeners
*new, *old
;
2057 struct netlink_table
*tbl
= &nl_table
[sk
->sk_protocol
];
2062 if (NLGRPSZ(tbl
->groups
) < NLGRPSZ(groups
)) {
2063 new = kzalloc(sizeof(*new) + NLGRPSZ(groups
), GFP_ATOMIC
);
2066 old
= nl_deref_protected(tbl
->listeners
);
2067 memcpy(new->masks
, old
->masks
, NLGRPSZ(tbl
->groups
));
2068 rcu_assign_pointer(tbl
->listeners
, new);
2070 kfree_rcu(old
, rcu
);
2072 tbl
->groups
= groups
;
2078 * netlink_change_ngroups - change number of multicast groups
2080 * This changes the number of multicast groups that are available
2081 * on a certain netlink family. Note that it is not possible to
2082 * change the number of groups to below 32. Also note that it does
2083 * not implicitly call netlink_clear_multicast_users() when the
2084 * number of groups is reduced.
2086 * @sk: The kernel netlink socket, as returned by netlink_kernel_create().
2087 * @groups: The new number of groups.
2089 int netlink_change_ngroups(struct sock
*sk
, unsigned int groups
)
2093 netlink_table_grab();
2094 err
= __netlink_change_ngroups(sk
, groups
);
2095 netlink_table_ungrab();
2100 void __netlink_clear_multicast_users(struct sock
*ksk
, unsigned int group
)
2103 struct netlink_table
*tbl
= &nl_table
[ksk
->sk_protocol
];
2105 sk_for_each_bound(sk
, &tbl
->mc_list
)
2106 netlink_update_socket_mc(nlk_sk(sk
), group
, 0);
2110 __nlmsg_put(struct sk_buff
*skb
, u32 portid
, u32 seq
, int type
, int len
, int flags
)
2112 struct nlmsghdr
*nlh
;
2113 int size
= nlmsg_msg_size(len
);
2115 nlh
= skb_put(skb
, NLMSG_ALIGN(size
));
2116 nlh
->nlmsg_type
= type
;
2117 nlh
->nlmsg_len
= size
;
2118 nlh
->nlmsg_flags
= flags
;
2119 nlh
->nlmsg_pid
= portid
;
2120 nlh
->nlmsg_seq
= seq
;
2121 if (!__builtin_constant_p(size
) || NLMSG_ALIGN(size
) - size
!= 0)
2122 memset(nlmsg_data(nlh
) + len
, 0, NLMSG_ALIGN(size
) - size
);
2125 EXPORT_SYMBOL(__nlmsg_put
);
2128 * It looks a bit ugly.
2129 * It would be better to create kernel thread.
2132 static int netlink_dump(struct sock
*sk
)
2134 struct netlink_sock
*nlk
= nlk_sk(sk
);
2135 struct netlink_callback
*cb
;
2136 struct sk_buff
*skb
= NULL
;
2137 struct nlmsghdr
*nlh
;
2138 struct module
*module
;
2139 int len
, err
= -ENOBUFS
;
2143 mutex_lock(nlk
->cb_mutex
);
2144 if (!nlk
->cb_running
) {
2149 if (atomic_read(&sk
->sk_rmem_alloc
) >= sk
->sk_rcvbuf
)
2152 /* NLMSG_GOODSIZE is small to avoid high order allocations being
2153 * required, but it makes sense to _attempt_ a 16K bytes allocation
2154 * to reduce number of system calls on dump operations, if user
2155 * ever provided a big enough buffer.
2158 alloc_min_size
= max_t(int, cb
->min_dump_alloc
, NLMSG_GOODSIZE
);
2160 if (alloc_min_size
< nlk
->max_recvmsg_len
) {
2161 alloc_size
= nlk
->max_recvmsg_len
;
2162 skb
= alloc_skb(alloc_size
,
2163 (GFP_KERNEL
& ~__GFP_DIRECT_RECLAIM
) |
2164 __GFP_NOWARN
| __GFP_NORETRY
);
2167 alloc_size
= alloc_min_size
;
2168 skb
= alloc_skb(alloc_size
, GFP_KERNEL
);
2173 /* Trim skb to allocated size. User is expected to provide buffer as
2174 * large as max(min_dump_alloc, 16KiB (mac_recvmsg_len capped at
2175 * netlink_recvmsg())). dump will pack as many smaller messages as
2176 * could fit within the allocated skb. skb is typically allocated
2177 * with larger space than required (could be as much as near 2x the
2178 * requested size with align to next power of 2 approach). Allowing
2179 * dump to use the excess space makes it difficult for a user to have a
2180 * reasonable static buffer based on the expected largest dump of a
2181 * single netdev. The outcome is MSG_TRUNC error.
2183 skb_reserve(skb
, skb_tailroom(skb
) - alloc_size
);
2184 netlink_skb_set_owner_r(skb
, sk
);
2186 len
= cb
->dump(skb
, cb
);
2189 mutex_unlock(nlk
->cb_mutex
);
2191 if (sk_filter(sk
, skb
))
2194 __netlink_sendskb(sk
, skb
);
2198 nlh
= nlmsg_put_answer(skb
, cb
, NLMSG_DONE
, sizeof(len
), NLM_F_MULTI
);
2202 nl_dump_check_consistent(cb
, nlh
);
2204 memcpy(nlmsg_data(nlh
), &len
, sizeof(len
));
2206 if (sk_filter(sk
, skb
))
2209 __netlink_sendskb(sk
, skb
);
2214 nlk
->cb_running
= false;
2215 module
= cb
->module
;
2217 mutex_unlock(nlk
->cb_mutex
);
2223 mutex_unlock(nlk
->cb_mutex
);
2228 int __netlink_dump_start(struct sock
*ssk
, struct sk_buff
*skb
,
2229 const struct nlmsghdr
*nlh
,
2230 struct netlink_dump_control
*control
)
2232 struct netlink_callback
*cb
;
2234 struct netlink_sock
*nlk
;
2237 refcount_inc(&skb
->users
);
2239 sk
= netlink_lookup(sock_net(ssk
), ssk
->sk_protocol
, NETLINK_CB(skb
).portid
);
2241 ret
= -ECONNREFUSED
;
2246 mutex_lock(nlk
->cb_mutex
);
2247 /* A dump is in progress... */
2248 if (nlk
->cb_running
) {
2252 /* add reference of module which cb->dump belongs to */
2253 if (!try_module_get(control
->module
)) {
2254 ret
= -EPROTONOSUPPORT
;
2259 memset(cb
, 0, sizeof(*cb
));
2260 cb
->start
= control
->start
;
2261 cb
->dump
= control
->dump
;
2262 cb
->done
= control
->done
;
2264 cb
->data
= control
->data
;
2265 cb
->module
= control
->module
;
2266 cb
->min_dump_alloc
= control
->min_dump_alloc
;
2270 ret
= cb
->start(cb
);
2275 nlk
->cb_running
= true;
2277 mutex_unlock(nlk
->cb_mutex
);
2279 ret
= netlink_dump(sk
);
2286 /* We successfully started a dump, by returning -EINTR we
2287 * signal not to send ACK even if it was requested.
2293 mutex_unlock(nlk
->cb_mutex
);
2298 EXPORT_SYMBOL(__netlink_dump_start
);
2300 void netlink_ack(struct sk_buff
*in_skb
, struct nlmsghdr
*nlh
, int err
,
2301 const struct netlink_ext_ack
*extack
)
2303 struct sk_buff
*skb
;
2304 struct nlmsghdr
*rep
;
2305 struct nlmsgerr
*errmsg
;
2306 size_t payload
= sizeof(*errmsg
);
2308 struct netlink_sock
*nlk
= nlk_sk(NETLINK_CB(in_skb
).sk
);
2309 unsigned int flags
= 0;
2310 bool nlk_has_extack
= nlk
->flags
& NETLINK_F_EXT_ACK
;
2312 /* Error messages get the original request appened, unless the user
2313 * requests to cap the error message, and get extra error data if
2317 if (!(nlk
->flags
& NETLINK_F_CAP_ACK
))
2318 payload
+= nlmsg_len(nlh
);
2320 flags
|= NLM_F_CAPPED
;
2321 if (nlk_has_extack
&& extack
) {
2323 tlvlen
+= nla_total_size(strlen(extack
->_msg
) + 1);
2324 if (extack
->bad_attr
)
2325 tlvlen
+= nla_total_size(sizeof(u32
));
2328 flags
|= NLM_F_CAPPED
;
2330 if (nlk_has_extack
&& extack
&& extack
->cookie_len
)
2331 tlvlen
+= nla_total_size(extack
->cookie_len
);
2335 flags
|= NLM_F_ACK_TLVS
;
2337 skb
= nlmsg_new(payload
+ tlvlen
, GFP_KERNEL
);
2341 sk
= netlink_lookup(sock_net(in_skb
->sk
),
2342 in_skb
->sk
->sk_protocol
,
2343 NETLINK_CB(in_skb
).portid
);
2345 sk
->sk_err
= ENOBUFS
;
2346 sk
->sk_error_report(sk
);
2352 rep
= __nlmsg_put(skb
, NETLINK_CB(in_skb
).portid
, nlh
->nlmsg_seq
,
2353 NLMSG_ERROR
, payload
, flags
);
2354 errmsg
= nlmsg_data(rep
);
2355 errmsg
->error
= err
;
2356 memcpy(&errmsg
->msg
, nlh
, payload
> sizeof(*errmsg
) ? nlh
->nlmsg_len
: sizeof(*nlh
));
2358 if (nlk_has_extack
&& extack
) {
2361 WARN_ON(nla_put_string(skb
, NLMSGERR_ATTR_MSG
,
2363 if (extack
->bad_attr
&&
2364 !WARN_ON((u8
*)extack
->bad_attr
< in_skb
->data
||
2365 (u8
*)extack
->bad_attr
>= in_skb
->data
+
2367 WARN_ON(nla_put_u32(skb
, NLMSGERR_ATTR_OFFS
,
2368 (u8
*)extack
->bad_attr
-
2371 if (extack
->cookie_len
)
2372 WARN_ON(nla_put(skb
, NLMSGERR_ATTR_COOKIE
,
2378 nlmsg_end(skb
, rep
);
2380 netlink_unicast(in_skb
->sk
, skb
, NETLINK_CB(in_skb
).portid
, MSG_DONTWAIT
);
2382 EXPORT_SYMBOL(netlink_ack
);
2384 int netlink_rcv_skb(struct sk_buff
*skb
, int (*cb
)(struct sk_buff
*,
2386 struct netlink_ext_ack
*))
2388 struct netlink_ext_ack extack
= {};
2389 struct nlmsghdr
*nlh
;
2392 while (skb
->len
>= nlmsg_total_size(0)) {
2395 nlh
= nlmsg_hdr(skb
);
2398 if (nlh
->nlmsg_len
< NLMSG_HDRLEN
|| skb
->len
< nlh
->nlmsg_len
)
2401 /* Only requests are handled by the kernel */
2402 if (!(nlh
->nlmsg_flags
& NLM_F_REQUEST
))
2405 /* Skip control messages */
2406 if (nlh
->nlmsg_type
< NLMSG_MIN_TYPE
)
2409 err
= cb(skb
, nlh
, &extack
);
2414 if (nlh
->nlmsg_flags
& NLM_F_ACK
|| err
)
2415 netlink_ack(skb
, nlh
, err
, &extack
);
2418 msglen
= NLMSG_ALIGN(nlh
->nlmsg_len
);
2419 if (msglen
> skb
->len
)
2421 skb_pull(skb
, msglen
);
2426 EXPORT_SYMBOL(netlink_rcv_skb
);
2429 * nlmsg_notify - send a notification netlink message
2430 * @sk: netlink socket to use
2431 * @skb: notification message
2432 * @portid: destination netlink portid for reports or 0
2433 * @group: destination multicast group or 0
2434 * @report: 1 to report back, 0 to disable
2435 * @flags: allocation flags
2437 int nlmsg_notify(struct sock
*sk
, struct sk_buff
*skb
, u32 portid
,
2438 unsigned int group
, int report
, gfp_t flags
)
2443 int exclude_portid
= 0;
2446 refcount_inc(&skb
->users
);
2447 exclude_portid
= portid
;
2450 /* errors reported via destination sk->sk_err, but propagate
2451 * delivery errors if NETLINK_BROADCAST_ERROR flag is set */
2452 err
= nlmsg_multicast(sk
, skb
, exclude_portid
, group
, flags
);
2458 err2
= nlmsg_unicast(sk
, skb
, portid
);
2459 if (!err
|| err
== -ESRCH
)
2465 EXPORT_SYMBOL(nlmsg_notify
);
2467 #ifdef CONFIG_PROC_FS
2468 struct nl_seq_iter
{
2469 struct seq_net_private p
;
2470 struct rhashtable_iter hti
;
2474 static int netlink_walk_start(struct nl_seq_iter
*iter
)
2478 err
= rhashtable_walk_init(&nl_table
[iter
->link
].hash
, &iter
->hti
,
2481 iter
->link
= MAX_LINKS
;
2485 err
= rhashtable_walk_start(&iter
->hti
);
2486 return err
== -EAGAIN
? 0 : err
;
2489 static void netlink_walk_stop(struct nl_seq_iter
*iter
)
2491 rhashtable_walk_stop(&iter
->hti
);
2492 rhashtable_walk_exit(&iter
->hti
);
2495 static void *__netlink_seq_next(struct seq_file
*seq
)
2497 struct nl_seq_iter
*iter
= seq
->private;
2498 struct netlink_sock
*nlk
;
2504 nlk
= rhashtable_walk_next(&iter
->hti
);
2507 if (PTR_ERR(nlk
) == -EAGAIN
)
2516 netlink_walk_stop(iter
);
2517 if (++iter
->link
>= MAX_LINKS
)
2520 err
= netlink_walk_start(iter
);
2522 return ERR_PTR(err
);
2524 } while (sock_net(&nlk
->sk
) != seq_file_net(seq
));
2529 static void *netlink_seq_start(struct seq_file
*seq
, loff_t
*posp
)
2531 struct nl_seq_iter
*iter
= seq
->private;
2532 void *obj
= SEQ_START_TOKEN
;
2538 err
= netlink_walk_start(iter
);
2540 return ERR_PTR(err
);
2542 for (pos
= *posp
; pos
&& obj
&& !IS_ERR(obj
); pos
--)
2543 obj
= __netlink_seq_next(seq
);
2548 static void *netlink_seq_next(struct seq_file
*seq
, void *v
, loff_t
*pos
)
2551 return __netlink_seq_next(seq
);
2554 static void netlink_seq_stop(struct seq_file
*seq
, void *v
)
2556 struct nl_seq_iter
*iter
= seq
->private;
2558 if (iter
->link
>= MAX_LINKS
)
2561 netlink_walk_stop(iter
);
2565 static int netlink_seq_show(struct seq_file
*seq
, void *v
)
2567 if (v
== SEQ_START_TOKEN
) {
2569 "sk Eth Pid Groups "
2570 "Rmem Wmem Dump Locks Drops Inode\n");
2573 struct netlink_sock
*nlk
= nlk_sk(s
);
2575 seq_printf(seq
, "%pK %-3d %-6u %08x %-8d %-8d %d %-8d %-8d %-8lu\n",
2579 nlk
->groups
? (u32
)nlk
->groups
[0] : 0,
2580 sk_rmem_alloc_get(s
),
2581 sk_wmem_alloc_get(s
),
2583 refcount_read(&s
->sk_refcnt
),
2584 atomic_read(&s
->sk_drops
),
2592 static const struct seq_operations netlink_seq_ops
= {
2593 .start
= netlink_seq_start
,
2594 .next
= netlink_seq_next
,
2595 .stop
= netlink_seq_stop
,
2596 .show
= netlink_seq_show
,
2600 static int netlink_seq_open(struct inode
*inode
, struct file
*file
)
2602 return seq_open_net(inode
, file
, &netlink_seq_ops
,
2603 sizeof(struct nl_seq_iter
));
2606 static const struct file_operations netlink_seq_fops
= {
2607 .owner
= THIS_MODULE
,
2608 .open
= netlink_seq_open
,
2610 .llseek
= seq_lseek
,
2611 .release
= seq_release_net
,
2616 int netlink_register_notifier(struct notifier_block
*nb
)
2618 return blocking_notifier_chain_register(&netlink_chain
, nb
);
2620 EXPORT_SYMBOL(netlink_register_notifier
);
2622 int netlink_unregister_notifier(struct notifier_block
*nb
)
2624 return blocking_notifier_chain_unregister(&netlink_chain
, nb
);
2626 EXPORT_SYMBOL(netlink_unregister_notifier
);
2628 static const struct proto_ops netlink_ops
= {
2629 .family
= PF_NETLINK
,
2630 .owner
= THIS_MODULE
,
2631 .release
= netlink_release
,
2632 .bind
= netlink_bind
,
2633 .connect
= netlink_connect
,
2634 .socketpair
= sock_no_socketpair
,
2635 .accept
= sock_no_accept
,
2636 .getname
= netlink_getname
,
2637 .poll
= datagram_poll
,
2638 .ioctl
= netlink_ioctl
,
2639 .listen
= sock_no_listen
,
2640 .shutdown
= sock_no_shutdown
,
2641 .setsockopt
= netlink_setsockopt
,
2642 .getsockopt
= netlink_getsockopt
,
2643 .sendmsg
= netlink_sendmsg
,
2644 .recvmsg
= netlink_recvmsg
,
2645 .mmap
= sock_no_mmap
,
2646 .sendpage
= sock_no_sendpage
,
2649 static const struct net_proto_family netlink_family_ops
= {
2650 .family
= PF_NETLINK
,
2651 .create
= netlink_create
,
2652 .owner
= THIS_MODULE
, /* for consistency 8) */
2655 static int __net_init
netlink_net_init(struct net
*net
)
2657 #ifdef CONFIG_PROC_FS
2658 if (!proc_create("netlink", 0, net
->proc_net
, &netlink_seq_fops
))
2664 static void __net_exit
netlink_net_exit(struct net
*net
)
2666 #ifdef CONFIG_PROC_FS
2667 remove_proc_entry("netlink", net
->proc_net
);
2671 static void __init
netlink_add_usersock_entry(void)
2673 struct listeners
*listeners
;
2676 listeners
= kzalloc(sizeof(*listeners
) + NLGRPSZ(groups
), GFP_KERNEL
);
2678 panic("netlink_add_usersock_entry: Cannot allocate listeners\n");
2680 netlink_table_grab();
2682 nl_table
[NETLINK_USERSOCK
].groups
= groups
;
2683 rcu_assign_pointer(nl_table
[NETLINK_USERSOCK
].listeners
, listeners
);
2684 nl_table
[NETLINK_USERSOCK
].module
= THIS_MODULE
;
2685 nl_table
[NETLINK_USERSOCK
].registered
= 1;
2686 nl_table
[NETLINK_USERSOCK
].flags
= NL_CFG_F_NONROOT_SEND
;
2688 netlink_table_ungrab();
2691 static struct pernet_operations __net_initdata netlink_net_ops
= {
2692 .init
= netlink_net_init
,
2693 .exit
= netlink_net_exit
,
2696 static inline u32
netlink_hash(const void *data
, u32 len
, u32 seed
)
2698 const struct netlink_sock
*nlk
= data
;
2699 struct netlink_compare_arg arg
;
2701 netlink_compare_arg_init(&arg
, sock_net(&nlk
->sk
), nlk
->portid
);
2702 return jhash2((u32
*)&arg
, netlink_compare_arg_len
/ sizeof(u32
), seed
);
2705 static const struct rhashtable_params netlink_rhashtable_params
= {
2706 .head_offset
= offsetof(struct netlink_sock
, node
),
2707 .key_len
= netlink_compare_arg_len
,
2708 .obj_hashfn
= netlink_hash
,
2709 .obj_cmpfn
= netlink_compare
,
2710 .automatic_shrinking
= true,
2713 static int __init
netlink_proto_init(void)
2716 int err
= proto_register(&netlink_proto
, 0);
2721 BUILD_BUG_ON(sizeof(struct netlink_skb_parms
) > FIELD_SIZEOF(struct sk_buff
, cb
));
2723 nl_table
= kcalloc(MAX_LINKS
, sizeof(*nl_table
), GFP_KERNEL
);
2727 for (i
= 0; i
< MAX_LINKS
; i
++) {
2728 if (rhashtable_init(&nl_table
[i
].hash
,
2729 &netlink_rhashtable_params
) < 0) {
2731 rhashtable_destroy(&nl_table
[i
].hash
);
2737 INIT_LIST_HEAD(&netlink_tap_all
);
2739 netlink_add_usersock_entry();
2741 sock_register(&netlink_family_ops
);
2742 register_pernet_subsys(&netlink_net_ops
);
2743 /* The netlink device handler may be needed early. */
2748 panic("netlink_init: Cannot allocate nl_table\n");
2751 core_initcall(netlink_proto_init
);