2 * NETLINK Kernel-user communication protocol.
4 * Authors: Alan Cox <alan@redhat.com>
5 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
12 * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith
13 * added netlink_proto_exit
14 * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br>
15 * use nlk_sk, as sk->protinfo is on a diet 8)
16 * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org>
17 * - inc module use count of module that owns
18 * the kernel socket in case userspace opens
19 * socket of same protocol
20 * - remove all module support, since netlink is
21 * mandatory if CONFIG_NET=y these days
24 #include <linux/module.h>
26 #include <linux/capability.h>
27 #include <linux/kernel.h>
28 #include <linux/init.h>
29 #include <linux/signal.h>
30 #include <linux/sched.h>
31 #include <linux/errno.h>
32 #include <linux/string.h>
33 #include <linux/stat.h>
34 #include <linux/socket.h>
36 #include <linux/fcntl.h>
37 #include <linux/termios.h>
38 #include <linux/sockios.h>
39 #include <linux/net.h>
41 #include <linux/slab.h>
42 #include <asm/uaccess.h>
43 #include <linux/skbuff.h>
44 #include <linux/netdevice.h>
45 #include <linux/rtnetlink.h>
46 #include <linux/proc_fs.h>
47 #include <linux/seq_file.h>
48 #include <linux/notifier.h>
49 #include <linux/security.h>
50 #include <linux/jhash.h>
51 #include <linux/jiffies.h>
52 #include <linux/random.h>
53 #include <linux/bitops.h>
55 #include <linux/types.h>
56 #include <linux/audit.h>
57 #include <linux/selinux.h>
58 #include <linux/mutex.h>
60 #include <net/net_namespace.h>
63 #include <net/netlink.h>
65 #define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8)
66 #define NLGRPLONGS(x) (NLGRPSZ(x)/sizeof(unsigned long))
69 /* struct sock has to be the first member of netlink_sock */
77 unsigned long *groups;
79 wait_queue_head_t wait;
80 struct netlink_callback *cb;
81 struct mutex *cb_mutex;
82 struct mutex cb_def_mutex;
83 void (*data_ready)(struct sock *sk, int bytes);
84 struct module *module;
87 #define NETLINK_KERNEL_SOCKET 0x1
88 #define NETLINK_RECV_PKTINFO 0x2
90 static inline struct netlink_sock *nlk_sk(struct sock *sk)
92 return container_of(sk, struct netlink_sock, sk);
95 static inline int netlink_is_kernel(struct sock *sk)
97 return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET;
101 struct hlist_head *table;
102 unsigned long rehash_time;
107 unsigned int entries;
108 unsigned int max_shift;
113 struct netlink_table {
114 struct nl_pid_hash hash;
115 struct hlist_head mc_list;
116 unsigned long *listeners;
117 unsigned int nl_nonroot;
119 struct mutex *cb_mutex;
120 struct module *module;
124 static struct netlink_table *nl_table;
126 static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
128 static int netlink_dump(struct sock *sk);
129 static void netlink_destroy_callback(struct netlink_callback *cb);
130 static void netlink_queue_skip(struct nlmsghdr *nlh, struct sk_buff *skb);
132 static DEFINE_RWLOCK(nl_table_lock);
133 static atomic_t nl_table_users = ATOMIC_INIT(0);
135 static ATOMIC_NOTIFIER_HEAD(netlink_chain);
137 static u32 netlink_group_mask(u32 group)
139 return group ? 1 << (group - 1) : 0;
142 static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid)
144 return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask];
147 static void netlink_sock_destruct(struct sock *sk)
149 struct netlink_sock *nlk = nlk_sk(sk);
153 nlk->cb->done(nlk->cb);
154 netlink_destroy_callback(nlk->cb);
157 skb_queue_purge(&sk->sk_receive_queue);
159 if (!sock_flag(sk, SOCK_DEAD)) {
160 printk("Freeing alive netlink socket %p\n", sk);
163 BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc));
164 BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
165 BUG_TRAP(!nlk_sk(sk)->groups);
168 /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on SMP.
169 * Look, when several writers sleep and reader wakes them up, all but one
170 * immediately hit write lock and grab all the cpus. Exclusive sleep solves
171 * this, _but_ remember, it adds useless work on UP machines.
174 static void netlink_table_grab(void)
176 write_lock_irq(&nl_table_lock);
178 if (atomic_read(&nl_table_users)) {
179 DECLARE_WAITQUEUE(wait, current);
181 add_wait_queue_exclusive(&nl_table_wait, &wait);
183 set_current_state(TASK_UNINTERRUPTIBLE);
184 if (atomic_read(&nl_table_users) == 0)
186 write_unlock_irq(&nl_table_lock);
188 write_lock_irq(&nl_table_lock);
191 __set_current_state(TASK_RUNNING);
192 remove_wait_queue(&nl_table_wait, &wait);
196 static __inline__ void netlink_table_ungrab(void)
198 write_unlock_irq(&nl_table_lock);
199 wake_up(&nl_table_wait);
202 static __inline__ void
203 netlink_lock_table(void)
205 /* read_lock() synchronizes us to netlink_table_grab */
207 read_lock(&nl_table_lock);
208 atomic_inc(&nl_table_users);
209 read_unlock(&nl_table_lock);
212 static __inline__ void
213 netlink_unlock_table(void)
215 if (atomic_dec_and_test(&nl_table_users))
216 wake_up(&nl_table_wait);
219 static __inline__ struct sock *netlink_lookup(struct net *net, int protocol, u32 pid)
221 struct nl_pid_hash *hash = &nl_table[protocol].hash;
222 struct hlist_head *head;
224 struct hlist_node *node;
226 read_lock(&nl_table_lock);
227 head = nl_pid_hashfn(hash, pid);
228 sk_for_each(sk, node, head) {
229 if ((sk->sk_net == net) && (nlk_sk(sk)->pid == pid)) {
236 read_unlock(&nl_table_lock);
240 static inline struct hlist_head *nl_pid_hash_alloc(size_t size)
242 if (size <= PAGE_SIZE)
243 return kmalloc(size, GFP_ATOMIC);
245 return (struct hlist_head *)
246 __get_free_pages(GFP_ATOMIC, get_order(size));
249 static inline void nl_pid_hash_free(struct hlist_head *table, size_t size)
251 if (size <= PAGE_SIZE)
254 free_pages((unsigned long)table, get_order(size));
257 static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow)
259 unsigned int omask, mask, shift;
261 struct hlist_head *otable, *table;
264 omask = mask = hash->mask;
265 osize = size = (mask + 1) * sizeof(*table);
269 if (++shift > hash->max_shift)
275 table = nl_pid_hash_alloc(size);
279 memset(table, 0, size);
280 otable = hash->table;
284 get_random_bytes(&hash->rnd, sizeof(hash->rnd));
286 for (i = 0; i <= omask; i++) {
288 struct hlist_node *node, *tmp;
290 sk_for_each_safe(sk, node, tmp, &otable[i])
291 __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid));
294 nl_pid_hash_free(otable, osize);
295 hash->rehash_time = jiffies + 10 * 60 * HZ;
299 static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len)
301 int avg = hash->entries >> hash->shift;
303 if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1))
306 if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) {
307 nl_pid_hash_rehash(hash, 0);
314 static const struct proto_ops netlink_ops;
317 netlink_update_listeners(struct sock *sk)
319 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
320 struct hlist_node *node;
324 for (i = 0; i < NLGRPLONGS(tbl->groups); i++) {
326 sk_for_each_bound(sk, node, &tbl->mc_list) {
327 if (i < NLGRPLONGS(nlk_sk(sk)->ngroups))
328 mask |= nlk_sk(sk)->groups[i];
330 tbl->listeners[i] = mask;
332 /* this function is only called with the netlink table "grabbed", which
333 * makes sure updates are visible before bind or setsockopt return. */
336 static int netlink_insert(struct sock *sk, struct net *net, u32 pid)
338 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
339 struct hlist_head *head;
340 int err = -EADDRINUSE;
342 struct hlist_node *node;
345 netlink_table_grab();
346 head = nl_pid_hashfn(hash, pid);
348 sk_for_each(osk, node, head) {
349 if ((osk->sk_net == net) && (nlk_sk(osk)->pid == pid))
361 if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX))
364 if (len && nl_pid_hash_dilute(hash, len))
365 head = nl_pid_hashfn(hash, pid);
367 nlk_sk(sk)->pid = pid;
368 sk_add_node(sk, head);
372 netlink_table_ungrab();
376 static void netlink_remove(struct sock *sk)
378 netlink_table_grab();
379 if (sk_del_node_init(sk))
380 nl_table[sk->sk_protocol].hash.entries--;
381 if (nlk_sk(sk)->subscriptions)
382 __sk_del_bind_node(sk);
383 netlink_table_ungrab();
386 static struct proto netlink_proto = {
388 .owner = THIS_MODULE,
389 .obj_size = sizeof(struct netlink_sock),
392 static int __netlink_create(struct net *net, struct socket *sock,
393 struct mutex *cb_mutex, int protocol)
396 struct netlink_sock *nlk;
398 sock->ops = &netlink_ops;
400 sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto, 1);
404 sock_init_data(sock, sk);
408 nlk->cb_mutex = cb_mutex;
410 nlk->cb_mutex = &nlk->cb_def_mutex;
411 mutex_init(nlk->cb_mutex);
413 init_waitqueue_head(&nlk->wait);
415 sk->sk_destruct = netlink_sock_destruct;
416 sk->sk_protocol = protocol;
420 static int netlink_create(struct net *net, struct socket *sock, int protocol)
422 struct module *module = NULL;
423 struct mutex *cb_mutex;
424 struct netlink_sock *nlk;
427 sock->state = SS_UNCONNECTED;
429 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
430 return -ESOCKTNOSUPPORT;
432 if (protocol<0 || protocol >= MAX_LINKS)
433 return -EPROTONOSUPPORT;
435 netlink_lock_table();
437 if (!nl_table[protocol].registered) {
438 netlink_unlock_table();
439 request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
440 netlink_lock_table();
443 if (nl_table[protocol].registered &&
444 try_module_get(nl_table[protocol].module))
445 module = nl_table[protocol].module;
446 cb_mutex = nl_table[protocol].cb_mutex;
447 netlink_unlock_table();
449 if ((err = __netlink_create(net, sock, cb_mutex, protocol)) < 0)
452 nlk = nlk_sk(sock->sk);
453 nlk->module = module;
462 static int netlink_release(struct socket *sock)
464 struct sock *sk = sock->sk;
465 struct netlink_sock *nlk;
475 * OK. Socket is unlinked, any packets that arrive now
480 wake_up_interruptible_all(&nlk->wait);
482 skb_queue_purge(&sk->sk_write_queue);
484 if (nlk->pid && !nlk->subscriptions) {
485 struct netlink_notify n = {
487 .protocol = sk->sk_protocol,
490 atomic_notifier_call_chain(&netlink_chain,
491 NETLINK_URELEASE, &n);
494 module_put(nlk->module);
496 netlink_table_grab();
497 if (netlink_is_kernel(sk)) {
498 kfree(nl_table[sk->sk_protocol].listeners);
499 nl_table[sk->sk_protocol].module = NULL;
500 nl_table[sk->sk_protocol].registered = 0;
501 } else if (nlk->subscriptions)
502 netlink_update_listeners(sk);
503 netlink_table_ungrab();
512 static int netlink_autobind(struct socket *sock)
514 struct sock *sk = sock->sk;
515 struct net *net = sk->sk_net;
516 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
517 struct hlist_head *head;
519 struct hlist_node *node;
520 s32 pid = current->tgid;
522 static s32 rover = -4097;
526 netlink_table_grab();
527 head = nl_pid_hashfn(hash, pid);
528 sk_for_each(osk, node, head) {
529 if ((osk->sk_net != net))
531 if (nlk_sk(osk)->pid == pid) {
532 /* Bind collision, search negative pid values. */
536 netlink_table_ungrab();
540 netlink_table_ungrab();
542 err = netlink_insert(sk, net, pid);
543 if (err == -EADDRINUSE)
546 /* If 2 threads race to autobind, that is fine. */
553 static inline int netlink_capable(struct socket *sock, unsigned int flag)
555 return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) ||
556 capable(CAP_NET_ADMIN);
560 netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions)
562 struct netlink_sock *nlk = nlk_sk(sk);
564 if (nlk->subscriptions && !subscriptions)
565 __sk_del_bind_node(sk);
566 else if (!nlk->subscriptions && subscriptions)
567 sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
568 nlk->subscriptions = subscriptions;
571 static int netlink_realloc_groups(struct sock *sk)
573 struct netlink_sock *nlk = nlk_sk(sk);
575 unsigned long *new_groups;
578 netlink_table_grab();
580 groups = nl_table[sk->sk_protocol].groups;
581 if (!nl_table[sk->sk_protocol].registered) {
586 if (nlk->ngroups >= groups)
589 new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC);
590 if (new_groups == NULL) {
594 memset((char*)new_groups + NLGRPSZ(nlk->ngroups), 0,
595 NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups));
597 nlk->groups = new_groups;
598 nlk->ngroups = groups;
600 netlink_table_ungrab();
604 static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
606 struct sock *sk = sock->sk;
607 struct net *net = sk->sk_net;
608 struct netlink_sock *nlk = nlk_sk(sk);
609 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
612 if (nladdr->nl_family != AF_NETLINK)
615 /* Only superuser is allowed to listen multicasts */
616 if (nladdr->nl_groups) {
617 if (!netlink_capable(sock, NL_NONROOT_RECV))
619 err = netlink_realloc_groups(sk);
625 if (nladdr->nl_pid != nlk->pid)
628 err = nladdr->nl_pid ?
629 netlink_insert(sk, net, nladdr->nl_pid) :
630 netlink_autobind(sock);
635 if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
638 netlink_table_grab();
639 netlink_update_subscriptions(sk, nlk->subscriptions +
640 hweight32(nladdr->nl_groups) -
641 hweight32(nlk->groups[0]));
642 nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups;
643 netlink_update_listeners(sk);
644 netlink_table_ungrab();
649 static int netlink_connect(struct socket *sock, struct sockaddr *addr,
653 struct sock *sk = sock->sk;
654 struct netlink_sock *nlk = nlk_sk(sk);
655 struct sockaddr_nl *nladdr=(struct sockaddr_nl*)addr;
657 if (addr->sa_family == AF_UNSPEC) {
658 sk->sk_state = NETLINK_UNCONNECTED;
663 if (addr->sa_family != AF_NETLINK)
666 /* Only superuser is allowed to send multicasts */
667 if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND))
671 err = netlink_autobind(sock);
674 sk->sk_state = NETLINK_CONNECTED;
675 nlk->dst_pid = nladdr->nl_pid;
676 nlk->dst_group = ffs(nladdr->nl_groups);
682 static int netlink_getname(struct socket *sock, struct sockaddr *addr, int *addr_len, int peer)
684 struct sock *sk = sock->sk;
685 struct netlink_sock *nlk = nlk_sk(sk);
686 struct sockaddr_nl *nladdr=(struct sockaddr_nl *)addr;
688 nladdr->nl_family = AF_NETLINK;
690 *addr_len = sizeof(*nladdr);
693 nladdr->nl_pid = nlk->dst_pid;
694 nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
696 nladdr->nl_pid = nlk->pid;
697 nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
702 static void netlink_overrun(struct sock *sk)
704 if (!test_and_set_bit(0, &nlk_sk(sk)->state)) {
705 sk->sk_err = ENOBUFS;
706 sk->sk_error_report(sk);
710 static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid)
712 int protocol = ssk->sk_protocol;
715 struct netlink_sock *nlk;
718 sock = netlink_lookup(net, protocol, pid);
720 return ERR_PTR(-ECONNREFUSED);
722 /* Don't bother queuing skb if kernel socket has no input function */
724 if ((netlink_is_kernel(sock) && !nlk->data_ready) ||
725 (sock->sk_state == NETLINK_CONNECTED &&
726 nlk->dst_pid != nlk_sk(ssk)->pid)) {
728 return ERR_PTR(-ECONNREFUSED);
733 struct sock *netlink_getsockbyfilp(struct file *filp)
735 struct inode *inode = filp->f_path.dentry->d_inode;
738 if (!S_ISSOCK(inode->i_mode))
739 return ERR_PTR(-ENOTSOCK);
741 sock = SOCKET_I(inode)->sk;
742 if (sock->sk_family != AF_NETLINK)
743 return ERR_PTR(-EINVAL);
750 * Attach a skb to a netlink socket.
751 * The caller must hold a reference to the destination socket. On error, the
752 * reference is dropped. The skb is not send to the destination, just all
753 * all error checks are performed and memory in the queue is reserved.
755 * < 0: error. skb freed, reference to sock dropped.
757 * 1: repeat lookup - reference dropped while waiting for socket memory.
759 int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock,
760 long timeo, struct sock *ssk)
762 struct netlink_sock *nlk;
766 if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
767 test_bit(0, &nlk->state)) {
768 DECLARE_WAITQUEUE(wait, current);
770 if (!ssk || netlink_is_kernel(ssk))
777 __set_current_state(TASK_INTERRUPTIBLE);
778 add_wait_queue(&nlk->wait, &wait);
780 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
781 test_bit(0, &nlk->state)) &&
782 !sock_flag(sk, SOCK_DEAD))
783 timeo = schedule_timeout(timeo);
785 __set_current_state(TASK_RUNNING);
786 remove_wait_queue(&nlk->wait, &wait);
789 if (signal_pending(current)) {
791 return sock_intr_errno(timeo);
795 skb_set_owner_r(skb, sk);
799 int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
803 skb_queue_tail(&sk->sk_receive_queue, skb);
804 sk->sk_data_ready(sk, len);
809 void netlink_detachskb(struct sock *sk, struct sk_buff *skb)
815 static inline struct sk_buff *netlink_trim(struct sk_buff *skb,
822 delta = skb->end - skb->tail;
823 if (delta * 2 < skb->truesize)
826 if (skb_shared(skb)) {
827 struct sk_buff *nskb = skb_clone(skb, allocation);
834 if (!pskb_expand_head(skb, 0, -delta, allocation))
835 skb->truesize -= delta;
840 int netlink_unicast(struct sock *ssk, struct sk_buff *skb, u32 pid, int nonblock)
846 skb = netlink_trim(skb, gfp_any());
848 timeo = sock_sndtimeo(ssk, nonblock);
850 sk = netlink_getsockbypid(ssk, pid);
855 err = netlink_attachskb(sk, skb, nonblock, timeo, ssk);
861 return netlink_sendskb(sk, skb);
864 int netlink_has_listeners(struct sock *sk, unsigned int group)
867 unsigned long *listeners;
869 BUG_ON(!netlink_is_kernel(sk));
872 listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners);
874 if (group - 1 < nl_table[sk->sk_protocol].groups)
875 res = test_bit(group - 1, listeners);
881 EXPORT_SYMBOL_GPL(netlink_has_listeners);
883 static __inline__ int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb)
885 struct netlink_sock *nlk = nlk_sk(sk);
887 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
888 !test_bit(0, &nlk->state)) {
889 skb_set_owner_r(skb, sk);
890 skb_queue_tail(&sk->sk_receive_queue, skb);
891 sk->sk_data_ready(sk, skb->len);
892 return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf;
897 struct netlink_broadcast_data {
898 struct sock *exclude_sk;
906 struct sk_buff *skb, *skb2;
909 static inline int do_one_broadcast(struct sock *sk,
910 struct netlink_broadcast_data *p)
912 struct netlink_sock *nlk = nlk_sk(sk);
915 if (p->exclude_sk == sk)
918 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
919 !test_bit(p->group - 1, nlk->groups))
922 if ((sk->sk_net != p->net))
931 if (p->skb2 == NULL) {
932 if (skb_shared(p->skb)) {
933 p->skb2 = skb_clone(p->skb, p->allocation);
935 p->skb2 = skb_get(p->skb);
937 * skb ownership may have been set when
938 * delivered to a previous socket.
943 if (p->skb2 == NULL) {
945 /* Clone failed. Notify ALL listeners. */
947 } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) {
960 int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
961 u32 group, gfp_t allocation)
963 struct net *net = ssk->sk_net;
964 struct netlink_broadcast_data info;
965 struct hlist_node *node;
968 skb = netlink_trim(skb, allocation);
970 info.exclude_sk = ssk;
977 info.allocation = allocation;
981 /* While we sleep in clone, do not allow to change socket list */
983 netlink_lock_table();
985 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
986 do_one_broadcast(sk, &info);
990 netlink_unlock_table();
993 kfree_skb(info.skb2);
995 if (info.delivered) {
996 if (info.congested && (allocation & __GFP_WAIT))
1005 struct netlink_set_err_data {
1006 struct sock *exclude_sk;
1012 static inline int do_one_set_err(struct sock *sk,
1013 struct netlink_set_err_data *p)
1015 struct netlink_sock *nlk = nlk_sk(sk);
1017 if (sk == p->exclude_sk)
1020 if (sk->sk_net != p->exclude_sk->sk_net)
1023 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
1024 !test_bit(p->group - 1, nlk->groups))
1027 sk->sk_err = p->code;
1028 sk->sk_error_report(sk);
1033 void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code)
1035 struct netlink_set_err_data info;
1036 struct hlist_node *node;
1039 info.exclude_sk = ssk;
1044 read_lock(&nl_table_lock);
1046 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
1047 do_one_set_err(sk, &info);
1049 read_unlock(&nl_table_lock);
1052 /* must be called with netlink table grabbed */
1053 static void netlink_update_socket_mc(struct netlink_sock *nlk,
1057 int old, new = !!is_new, subscriptions;
1059 old = test_bit(group - 1, nlk->groups);
1060 subscriptions = nlk->subscriptions - old + new;
1062 __set_bit(group - 1, nlk->groups);
1064 __clear_bit(group - 1, nlk->groups);
1065 netlink_update_subscriptions(&nlk->sk, subscriptions);
1066 netlink_update_listeners(&nlk->sk);
1069 static int netlink_setsockopt(struct socket *sock, int level, int optname,
1070 char __user *optval, int optlen)
1072 struct sock *sk = sock->sk;
1073 struct netlink_sock *nlk = nlk_sk(sk);
1074 unsigned int val = 0;
1077 if (level != SOL_NETLINK)
1078 return -ENOPROTOOPT;
1080 if (optlen >= sizeof(int) &&
1081 get_user(val, (unsigned int __user *)optval))
1085 case NETLINK_PKTINFO:
1087 nlk->flags |= NETLINK_RECV_PKTINFO;
1089 nlk->flags &= ~NETLINK_RECV_PKTINFO;
1092 case NETLINK_ADD_MEMBERSHIP:
1093 case NETLINK_DROP_MEMBERSHIP: {
1094 if (!netlink_capable(sock, NL_NONROOT_RECV))
1096 err = netlink_realloc_groups(sk);
1099 if (!val || val - 1 >= nlk->ngroups)
1101 netlink_table_grab();
1102 netlink_update_socket_mc(nlk, val,
1103 optname == NETLINK_ADD_MEMBERSHIP);
1104 netlink_table_ungrab();
1114 static int netlink_getsockopt(struct socket *sock, int level, int optname,
1115 char __user *optval, int __user *optlen)
1117 struct sock *sk = sock->sk;
1118 struct netlink_sock *nlk = nlk_sk(sk);
1121 if (level != SOL_NETLINK)
1122 return -ENOPROTOOPT;
1124 if (get_user(len, optlen))
1130 case NETLINK_PKTINFO:
1131 if (len < sizeof(int))
1134 val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0;
1135 if (put_user(len, optlen) ||
1136 put_user(val, optval))
1146 static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
1148 struct nl_pktinfo info;
1150 info.group = NETLINK_CB(skb).dst_group;
1151 put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info);
1154 static inline void netlink_rcv_wake(struct sock *sk)
1156 struct netlink_sock *nlk = nlk_sk(sk);
1158 if (skb_queue_empty(&sk->sk_receive_queue))
1159 clear_bit(0, &nlk->state);
1160 if (!test_bit(0, &nlk->state))
1161 wake_up_interruptible(&nlk->wait);
1164 static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
1165 struct msghdr *msg, size_t len)
1167 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1168 struct sock *sk = sock->sk;
1169 struct netlink_sock *nlk = nlk_sk(sk);
1170 struct sockaddr_nl *addr=msg->msg_name;
1173 struct sk_buff *skb;
1175 struct scm_cookie scm;
1177 if (msg->msg_flags&MSG_OOB)
1180 if (NULL == siocb->scm)
1182 err = scm_send(sock, msg, siocb->scm);
1186 if (msg->msg_namelen) {
1187 if (addr->nl_family != AF_NETLINK)
1189 dst_pid = addr->nl_pid;
1190 dst_group = ffs(addr->nl_groups);
1191 if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND))
1194 dst_pid = nlk->dst_pid;
1195 dst_group = nlk->dst_group;
1199 err = netlink_autobind(sock);
1205 if (len > sk->sk_sndbuf - 32)
1208 skb = alloc_skb(len, GFP_KERNEL);
1212 NETLINK_CB(skb).pid = nlk->pid;
1213 NETLINK_CB(skb).dst_group = dst_group;
1214 NETLINK_CB(skb).loginuid = audit_get_loginuid(current->audit_context);
1215 selinux_get_task_sid(current, &(NETLINK_CB(skb).sid));
1216 memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1218 /* What can I do? Netlink is asynchronous, so that
1219 we will have to save current capabilities to
1220 check them, when this message will be delivered
1221 to corresponding kernel module. --ANK (980802)
1225 if (memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len)) {
1230 err = security_netlink_send(sk, skb);
1237 atomic_inc(&skb->users);
1238 netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL);
1240 err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT);
1246 static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
1247 struct msghdr *msg, size_t len,
1250 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1251 struct scm_cookie scm;
1252 struct sock *sk = sock->sk;
1253 struct netlink_sock *nlk = nlk_sk(sk);
1254 int noblock = flags&MSG_DONTWAIT;
1256 struct sk_buff *skb;
1264 skb = skb_recv_datagram(sk,flags,noblock,&err);
1268 msg->msg_namelen = 0;
1272 msg->msg_flags |= MSG_TRUNC;
1276 skb_reset_transport_header(skb);
1277 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
1279 if (msg->msg_name) {
1280 struct sockaddr_nl *addr = (struct sockaddr_nl*)msg->msg_name;
1281 addr->nl_family = AF_NETLINK;
1283 addr->nl_pid = NETLINK_CB(skb).pid;
1284 addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group);
1285 msg->msg_namelen = sizeof(*addr);
1288 if (nlk->flags & NETLINK_RECV_PKTINFO)
1289 netlink_cmsg_recv_pktinfo(msg, skb);
1291 if (NULL == siocb->scm) {
1292 memset(&scm, 0, sizeof(scm));
1295 siocb->scm->creds = *NETLINK_CREDS(skb);
1296 if (flags & MSG_TRUNC)
1298 skb_free_datagram(sk, skb);
1300 if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2)
1303 scm_recv(sock, msg, siocb->scm, flags);
1305 netlink_rcv_wake(sk);
1306 return err ? : copied;
1309 static void netlink_data_ready(struct sock *sk, int len)
1311 struct netlink_sock *nlk = nlk_sk(sk);
1313 if (nlk->data_ready)
1314 nlk->data_ready(sk, len);
1315 netlink_rcv_wake(sk);
1319 * We export these functions to other modules. They provide a
1320 * complete set of kernel non-blocking support for message
1325 netlink_kernel_create(struct net *net, int unit, unsigned int groups,
1326 void (*input)(struct sock *sk, int len),
1327 struct mutex *cb_mutex, struct module *module)
1329 struct socket *sock;
1331 struct netlink_sock *nlk;
1332 unsigned long *listeners = NULL;
1336 if (unit<0 || unit>=MAX_LINKS)
1339 if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
1342 if (__netlink_create(net, sock, cb_mutex, unit) < 0)
1343 goto out_sock_release;
1348 listeners = kzalloc(NLGRPSZ(groups), GFP_KERNEL);
1350 goto out_sock_release;
1353 sk->sk_data_ready = netlink_data_ready;
1355 nlk_sk(sk)->data_ready = input;
1357 if (netlink_insert(sk, net, 0))
1358 goto out_sock_release;
1361 nlk->flags |= NETLINK_KERNEL_SOCKET;
1363 netlink_table_grab();
1364 if (!nl_table[unit].registered) {
1365 nl_table[unit].groups = groups;
1366 nl_table[unit].listeners = listeners;
1367 nl_table[unit].cb_mutex = cb_mutex;
1368 nl_table[unit].module = module;
1369 nl_table[unit].registered = 1;
1371 netlink_table_ungrab();
1382 * netlink_change_ngroups - change number of multicast groups
1384 * This changes the number of multicast groups that are available
1385 * on a certain netlink family. Note that it is not possible to
1386 * change the number of groups to below 32. Also note that it does
1387 * not implicitly call netlink_clear_multicast_users() when the
1388 * number of groups is reduced.
1390 * @sk: The kernel netlink socket, as returned by netlink_kernel_create().
1391 * @groups: The new number of groups.
1393 int netlink_change_ngroups(struct sock *sk, unsigned int groups)
1395 unsigned long *listeners, *old = NULL;
1396 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
1402 netlink_table_grab();
1403 if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) {
1404 listeners = kzalloc(NLGRPSZ(groups), GFP_ATOMIC);
1409 old = tbl->listeners;
1410 memcpy(listeners, old, NLGRPSZ(tbl->groups));
1411 rcu_assign_pointer(tbl->listeners, listeners);
1413 tbl->groups = groups;
1416 netlink_table_ungrab();
1421 EXPORT_SYMBOL(netlink_change_ngroups);
1424 * netlink_clear_multicast_users - kick off multicast listeners
1426 * This function removes all listeners from the given group.
1427 * @ksk: The kernel netlink socket, as returned by
1428 * netlink_kernel_create().
1429 * @group: The multicast group to clear.
1431 void netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
1434 struct hlist_node *node;
1435 struct netlink_table *tbl = &nl_table[ksk->sk_protocol];
1437 netlink_table_grab();
1439 sk_for_each_bound(sk, node, &tbl->mc_list)
1440 netlink_update_socket_mc(nlk_sk(sk), group, 0);
1442 netlink_table_ungrab();
1444 EXPORT_SYMBOL(netlink_clear_multicast_users);
1446 void netlink_set_nonroot(int protocol, unsigned int flags)
1448 if ((unsigned int)protocol < MAX_LINKS)
1449 nl_table[protocol].nl_nonroot = flags;
1452 static void netlink_destroy_callback(struct netlink_callback *cb)
1460 * It looks a bit ugly.
1461 * It would be better to create kernel thread.
1464 static int netlink_dump(struct sock *sk)
1466 struct netlink_sock *nlk = nlk_sk(sk);
1467 struct netlink_callback *cb;
1468 struct sk_buff *skb;
1469 struct nlmsghdr *nlh;
1470 int len, err = -ENOBUFS;
1472 skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL);
1476 mutex_lock(nlk->cb_mutex);
1484 len = cb->dump(skb, cb);
1487 mutex_unlock(nlk->cb_mutex);
1488 skb_queue_tail(&sk->sk_receive_queue, skb);
1489 sk->sk_data_ready(sk, len);
1493 nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI);
1497 memcpy(nlmsg_data(nlh), &len, sizeof(len));
1499 skb_queue_tail(&sk->sk_receive_queue, skb);
1500 sk->sk_data_ready(sk, skb->len);
1505 mutex_unlock(nlk->cb_mutex);
1507 netlink_destroy_callback(cb);
1511 mutex_unlock(nlk->cb_mutex);
1517 int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
1518 struct nlmsghdr *nlh,
1519 int (*dump)(struct sk_buff *skb, struct netlink_callback*),
1520 int (*done)(struct netlink_callback*))
1522 struct netlink_callback *cb;
1524 struct netlink_sock *nlk;
1526 cb = kzalloc(sizeof(*cb), GFP_KERNEL);
1533 atomic_inc(&skb->users);
1536 sk = netlink_lookup(ssk->sk_net, ssk->sk_protocol, NETLINK_CB(skb).pid);
1538 netlink_destroy_callback(cb);
1539 return -ECONNREFUSED;
1542 /* A dump is in progress... */
1543 mutex_lock(nlk->cb_mutex);
1545 mutex_unlock(nlk->cb_mutex);
1546 netlink_destroy_callback(cb);
1551 mutex_unlock(nlk->cb_mutex);
1556 /* We successfully started a dump, by returning -EINTR we
1557 * signal the queue mangement to interrupt processing of
1558 * any netlink messages so userspace gets a chance to read
1563 void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
1565 struct sk_buff *skb;
1566 struct nlmsghdr *rep;
1567 struct nlmsgerr *errmsg;
1568 size_t payload = sizeof(*errmsg);
1570 /* error messages get the original request appened */
1572 payload += nlmsg_len(nlh);
1574 skb = nlmsg_new(payload, GFP_KERNEL);
1578 sk = netlink_lookup(in_skb->sk->sk_net,
1579 in_skb->sk->sk_protocol,
1580 NETLINK_CB(in_skb).pid);
1582 sk->sk_err = ENOBUFS;
1583 sk->sk_error_report(sk);
1589 rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
1590 NLMSG_ERROR, sizeof(struct nlmsgerr), 0);
1591 errmsg = nlmsg_data(rep);
1592 errmsg->error = err;
1593 memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh));
1594 netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
1597 static int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
1600 struct nlmsghdr *nlh;
1603 while (skb->len >= nlmsg_total_size(0)) {
1604 nlh = nlmsg_hdr(skb);
1607 if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
1610 /* Only requests are handled by the kernel */
1611 if (!(nlh->nlmsg_flags & NLM_F_REQUEST))
1614 /* Skip control messages */
1615 if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
1619 if (err == -EINTR) {
1620 /* Not an error, but we interrupt processing */
1621 netlink_queue_skip(nlh, skb);
1625 if (nlh->nlmsg_flags & NLM_F_ACK || err)
1626 netlink_ack(skb, nlh, err);
1628 netlink_queue_skip(nlh, skb);
1635 * nelink_run_queue - Process netlink receive queue.
1636 * @sk: Netlink socket containing the queue
1637 * @qlen: Initial queue length
1638 * @cb: Callback function invoked for each netlink message found
1640 * Processes as much as there was in the queue upon entry and invokes
1641 * a callback function for each netlink message found. The callback
1642 * function may refuse a message by returning a negative error code
1643 * but setting the error pointer to 0 in which case this function
1644 * returns with a qlen != 0.
1646 * qlen must be initialized to 0 before the initial entry, afterwards
1647 * the function may be called repeatedly until the returned qlen is 0.
1649 * The callback function may return -EINTR to signal that processing
1650 * of netlink messages shall be interrupted. In this case the message
1651 * currently being processed will NOT be requeued onto the receive
1654 unsigned int netlink_run_queue(struct sock *sk, unsigned int qlen,
1655 int (*cb)(struct sk_buff *, struct nlmsghdr *))
1657 struct sk_buff *skb;
1659 if (!qlen || qlen > skb_queue_len(&sk->sk_receive_queue))
1660 qlen = skb_queue_len(&sk->sk_receive_queue);
1662 for (; qlen; qlen--) {
1663 skb = skb_dequeue(&sk->sk_receive_queue);
1664 if (netlink_rcv_skb(skb, cb)) {
1666 skb_queue_head(&sk->sk_receive_queue, skb);
1681 * netlink_queue_skip - Skip netlink message while processing queue.
1682 * @nlh: Netlink message to be skipped
1683 * @skb: Socket buffer containing the netlink messages.
1685 * Pulls the given netlink message off the socket buffer so the next
1686 * call to netlink_queue_run() will not reconsider the message.
1688 static void netlink_queue_skip(struct nlmsghdr *nlh, struct sk_buff *skb)
1690 int msglen = NLMSG_ALIGN(nlh->nlmsg_len);
1692 if (msglen > skb->len)
1695 skb_pull(skb, msglen);
1699 * nlmsg_notify - send a notification netlink message
1700 * @sk: netlink socket to use
1701 * @skb: notification message
1702 * @pid: destination netlink pid for reports or 0
1703 * @group: destination multicast group or 0
1704 * @report: 1 to report back, 0 to disable
1705 * @flags: allocation flags
1707 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid,
1708 unsigned int group, int report, gfp_t flags)
1713 int exclude_pid = 0;
1716 atomic_inc(&skb->users);
1720 /* errors reported via destination sk->sk_err */
1721 nlmsg_multicast(sk, skb, exclude_pid, group, flags);
1725 err = nlmsg_unicast(sk, skb, pid);
1730 #ifdef CONFIG_PROC_FS
1731 struct nl_seq_iter {
1737 static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos)
1739 struct nl_seq_iter *iter = seq->private;
1742 struct hlist_node *node;
1745 for (i=0; i<MAX_LINKS; i++) {
1746 struct nl_pid_hash *hash = &nl_table[i].hash;
1748 for (j = 0; j <= hash->mask; j++) {
1749 sk_for_each(s, node, &hash->table[j]) {
1750 if (iter->net != s->sk_net)
1764 static void *netlink_seq_start(struct seq_file *seq, loff_t *pos)
1766 read_lock(&nl_table_lock);
1767 return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN;
1770 static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1773 struct nl_seq_iter *iter;
1778 if (v == SEQ_START_TOKEN)
1779 return netlink_seq_socket_idx(seq, 0);
1781 iter = seq->private;
1785 } while (s && (iter->net != s->sk_net));
1790 j = iter->hash_idx + 1;
1793 struct nl_pid_hash *hash = &nl_table[i].hash;
1795 for (; j <= hash->mask; j++) {
1796 s = sk_head(&hash->table[j]);
1797 while (s && (iter->net != s->sk_net))
1807 } while (++i < MAX_LINKS);
1812 static void netlink_seq_stop(struct seq_file *seq, void *v)
1814 read_unlock(&nl_table_lock);
1818 static int netlink_seq_show(struct seq_file *seq, void *v)
1820 if (v == SEQ_START_TOKEN)
1822 "sk Eth Pid Groups "
1823 "Rmem Wmem Dump Locks\n");
1826 struct netlink_sock *nlk = nlk_sk(s);
1828 seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %d\n",
1832 nlk->groups ? (u32)nlk->groups[0] : 0,
1833 atomic_read(&s->sk_rmem_alloc),
1834 atomic_read(&s->sk_wmem_alloc),
1836 atomic_read(&s->sk_refcnt)
1843 static const struct seq_operations netlink_seq_ops = {
1844 .start = netlink_seq_start,
1845 .next = netlink_seq_next,
1846 .stop = netlink_seq_stop,
1847 .show = netlink_seq_show,
1851 static int netlink_seq_open(struct inode *inode, struct file *file)
1853 struct nl_seq_iter *iter;
1855 iter = __seq_open_private(file, &netlink_seq_ops, sizeof(*iter));
1859 iter->net = get_proc_net(inode);
1861 seq_release_private(inode, file);
1868 static int netlink_seq_release(struct inode *inode, struct file *file)
1870 struct seq_file *seq = file->private_data;
1871 struct nl_seq_iter *iter = seq->private;
1873 return seq_release_private(inode, file);
1876 static const struct file_operations netlink_seq_fops = {
1877 .owner = THIS_MODULE,
1878 .open = netlink_seq_open,
1880 .llseek = seq_lseek,
1881 .release = netlink_seq_release,
1886 int netlink_register_notifier(struct notifier_block *nb)
1888 return atomic_notifier_chain_register(&netlink_chain, nb);
1891 int netlink_unregister_notifier(struct notifier_block *nb)
1893 return atomic_notifier_chain_unregister(&netlink_chain, nb);
1896 static const struct proto_ops netlink_ops = {
1897 .family = PF_NETLINK,
1898 .owner = THIS_MODULE,
1899 .release = netlink_release,
1900 .bind = netlink_bind,
1901 .connect = netlink_connect,
1902 .socketpair = sock_no_socketpair,
1903 .accept = sock_no_accept,
1904 .getname = netlink_getname,
1905 .poll = datagram_poll,
1906 .ioctl = sock_no_ioctl,
1907 .listen = sock_no_listen,
1908 .shutdown = sock_no_shutdown,
1909 .setsockopt = netlink_setsockopt,
1910 .getsockopt = netlink_getsockopt,
1911 .sendmsg = netlink_sendmsg,
1912 .recvmsg = netlink_recvmsg,
1913 .mmap = sock_no_mmap,
1914 .sendpage = sock_no_sendpage,
1917 static struct net_proto_family netlink_family_ops = {
1918 .family = PF_NETLINK,
1919 .create = netlink_create,
1920 .owner = THIS_MODULE, /* for consistency 8) */
1923 static int __net_init netlink_net_init(struct net *net)
1925 #ifdef CONFIG_PROC_FS
1926 if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops))
1932 static void __net_exit netlink_net_exit(struct net *net)
1934 #ifdef CONFIG_PROC_FS
1935 proc_net_remove(net, "netlink");
1939 static struct pernet_operations __net_initdata netlink_net_ops = {
1940 .init = netlink_net_init,
1941 .exit = netlink_net_exit,
1944 static int __init netlink_proto_init(void)
1946 struct sk_buff *dummy_skb;
1948 unsigned long limit;
1950 int err = proto_register(&netlink_proto, 0);
1955 BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb));
1957 nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);
1961 if (num_physpages >= (128 * 1024))
1962 limit = num_physpages >> (21 - PAGE_SHIFT);
1964 limit = num_physpages >> (23 - PAGE_SHIFT);
1966 order = get_bitmask_order(limit) - 1 + PAGE_SHIFT;
1967 limit = (1UL << order) / sizeof(struct hlist_head);
1968 order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1;
1970 for (i = 0; i < MAX_LINKS; i++) {
1971 struct nl_pid_hash *hash = &nl_table[i].hash;
1973 hash->table = nl_pid_hash_alloc(1 * sizeof(*hash->table));
1976 nl_pid_hash_free(nl_table[i].hash.table,
1977 1 * sizeof(*hash->table));
1981 memset(hash->table, 0, 1 * sizeof(*hash->table));
1982 hash->max_shift = order;
1985 hash->rehash_time = jiffies;
1988 sock_register(&netlink_family_ops);
1989 register_pernet_subsys(&netlink_net_ops);
1990 /* The netlink device handler may be needed early. */
1995 panic("netlink_init: Cannot allocate nl_table\n");
1998 core_initcall(netlink_proto_init);
2000 EXPORT_SYMBOL(netlink_ack);
2001 EXPORT_SYMBOL(netlink_run_queue);
2002 EXPORT_SYMBOL(netlink_broadcast);
2003 EXPORT_SYMBOL(netlink_dump_start);
2004 EXPORT_SYMBOL(netlink_kernel_create);
2005 EXPORT_SYMBOL(netlink_register_notifier);
2006 EXPORT_SYMBOL(netlink_set_nonroot);
2007 EXPORT_SYMBOL(netlink_unicast);
2008 EXPORT_SYMBOL(netlink_unregister_notifier);
2009 EXPORT_SYMBOL(nlmsg_notify);