2 * NETLINK Kernel-user communication protocol.
4 * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk>
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/mutex.h>
59 #include <net/net_namespace.h>
62 #include <net/netlink.h>
64 #define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8)
65 #define NLGRPLONGS(x) (NLGRPSZ(x)/sizeof(unsigned long))
68 /* struct sock has to be the first member of netlink_sock */
76 unsigned long *groups;
78 wait_queue_head_t wait;
79 struct netlink_callback *cb;
80 struct mutex *cb_mutex;
81 struct mutex cb_def_mutex;
82 void (*netlink_rcv)(struct sk_buff *skb);
83 struct module *module;
88 unsigned long masks[0];
91 #define NETLINK_KERNEL_SOCKET 0x1
92 #define NETLINK_RECV_PKTINFO 0x2
93 #define NETLINK_BROADCAST_SEND_ERROR 0x4
94 #define NETLINK_RECV_NO_ENOBUFS 0x8
96 static inline struct netlink_sock *nlk_sk(struct sock *sk)
98 return container_of(sk, struct netlink_sock, sk);
101 static inline int netlink_is_kernel(struct sock *sk)
103 return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET;
107 struct hlist_head *table;
108 unsigned long rehash_time;
113 unsigned int entries;
114 unsigned int max_shift;
119 struct netlink_table {
120 struct nl_pid_hash hash;
121 struct hlist_head mc_list;
122 struct listeners __rcu *listeners;
123 unsigned int nl_nonroot;
125 struct mutex *cb_mutex;
126 struct module *module;
130 static struct netlink_table *nl_table;
132 static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
134 static int netlink_dump(struct sock *sk);
135 static void netlink_destroy_callback(struct netlink_callback *cb);
137 static DEFINE_RWLOCK(nl_table_lock);
138 static atomic_t nl_table_users = ATOMIC_INIT(0);
140 #define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock));
142 static ATOMIC_NOTIFIER_HEAD(netlink_chain);
144 static u32 netlink_group_mask(u32 group)
146 return group ? 1 << (group - 1) : 0;
149 static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid)
151 return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask];
154 static void netlink_sock_destruct(struct sock *sk)
156 struct netlink_sock *nlk = nlk_sk(sk);
160 nlk->cb->done(nlk->cb);
161 netlink_destroy_callback(nlk->cb);
164 skb_queue_purge(&sk->sk_receive_queue);
166 if (!sock_flag(sk, SOCK_DEAD)) {
167 printk(KERN_ERR "Freeing alive netlink socket %p\n", sk);
171 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
172 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
173 WARN_ON(nlk_sk(sk)->groups);
176 /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on
177 * SMP. Look, when several writers sleep and reader wakes them up, all but one
178 * immediately hit write lock and grab all the cpus. Exclusive sleep solves
179 * this, _but_ remember, it adds useless work on UP machines.
182 void netlink_table_grab(void)
183 __acquires(nl_table_lock)
187 write_lock_irq(&nl_table_lock);
189 if (atomic_read(&nl_table_users)) {
190 DECLARE_WAITQUEUE(wait, current);
192 add_wait_queue_exclusive(&nl_table_wait, &wait);
194 set_current_state(TASK_UNINTERRUPTIBLE);
195 if (atomic_read(&nl_table_users) == 0)
197 write_unlock_irq(&nl_table_lock);
199 write_lock_irq(&nl_table_lock);
202 __set_current_state(TASK_RUNNING);
203 remove_wait_queue(&nl_table_wait, &wait);
207 void netlink_table_ungrab(void)
208 __releases(nl_table_lock)
210 write_unlock_irq(&nl_table_lock);
211 wake_up(&nl_table_wait);
215 netlink_lock_table(void)
217 /* read_lock() synchronizes us to netlink_table_grab */
219 read_lock(&nl_table_lock);
220 atomic_inc(&nl_table_users);
221 read_unlock(&nl_table_lock);
225 netlink_unlock_table(void)
227 if (atomic_dec_and_test(&nl_table_users))
228 wake_up(&nl_table_wait);
231 static inline struct sock *netlink_lookup(struct net *net, int protocol,
234 struct nl_pid_hash *hash = &nl_table[protocol].hash;
235 struct hlist_head *head;
237 struct hlist_node *node;
239 read_lock(&nl_table_lock);
240 head = nl_pid_hashfn(hash, pid);
241 sk_for_each(sk, node, head) {
242 if (net_eq(sock_net(sk), net) && (nlk_sk(sk)->pid == pid)) {
249 read_unlock(&nl_table_lock);
253 static inline struct hlist_head *nl_pid_hash_zalloc(size_t size)
255 if (size <= PAGE_SIZE)
256 return kzalloc(size, GFP_ATOMIC);
258 return (struct hlist_head *)
259 __get_free_pages(GFP_ATOMIC | __GFP_ZERO,
263 static inline void nl_pid_hash_free(struct hlist_head *table, size_t size)
265 if (size <= PAGE_SIZE)
268 free_pages((unsigned long)table, get_order(size));
271 static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow)
273 unsigned int omask, mask, shift;
275 struct hlist_head *otable, *table;
278 omask = mask = hash->mask;
279 osize = size = (mask + 1) * sizeof(*table);
283 if (++shift > hash->max_shift)
289 table = nl_pid_hash_zalloc(size);
293 otable = hash->table;
297 get_random_bytes(&hash->rnd, sizeof(hash->rnd));
299 for (i = 0; i <= omask; i++) {
301 struct hlist_node *node, *tmp;
303 sk_for_each_safe(sk, node, tmp, &otable[i])
304 __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid));
307 nl_pid_hash_free(otable, osize);
308 hash->rehash_time = jiffies + 10 * 60 * HZ;
312 static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len)
314 int avg = hash->entries >> hash->shift;
316 if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1))
319 if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) {
320 nl_pid_hash_rehash(hash, 0);
327 static const struct proto_ops netlink_ops;
330 netlink_update_listeners(struct sock *sk)
332 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
333 struct hlist_node *node;
336 struct listeners *listeners;
338 listeners = nl_deref_protected(tbl->listeners);
342 for (i = 0; i < NLGRPLONGS(tbl->groups); i++) {
344 sk_for_each_bound(sk, node, &tbl->mc_list) {
345 if (i < NLGRPLONGS(nlk_sk(sk)->ngroups))
346 mask |= nlk_sk(sk)->groups[i];
348 listeners->masks[i] = mask;
350 /* this function is only called with the netlink table "grabbed", which
351 * makes sure updates are visible before bind or setsockopt return. */
354 static int netlink_insert(struct sock *sk, struct net *net, u32 pid)
356 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
357 struct hlist_head *head;
358 int err = -EADDRINUSE;
360 struct hlist_node *node;
363 netlink_table_grab();
364 head = nl_pid_hashfn(hash, pid);
366 sk_for_each(osk, node, head) {
367 if (net_eq(sock_net(osk), net) && (nlk_sk(osk)->pid == pid))
379 if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX))
382 if (len && nl_pid_hash_dilute(hash, len))
383 head = nl_pid_hashfn(hash, pid);
385 nlk_sk(sk)->pid = pid;
386 sk_add_node(sk, head);
390 netlink_table_ungrab();
394 static void netlink_remove(struct sock *sk)
396 netlink_table_grab();
397 if (sk_del_node_init(sk))
398 nl_table[sk->sk_protocol].hash.entries--;
399 if (nlk_sk(sk)->subscriptions)
400 __sk_del_bind_node(sk);
401 netlink_table_ungrab();
404 static struct proto netlink_proto = {
406 .owner = THIS_MODULE,
407 .obj_size = sizeof(struct netlink_sock),
410 static int __netlink_create(struct net *net, struct socket *sock,
411 struct mutex *cb_mutex, int protocol)
414 struct netlink_sock *nlk;
416 sock->ops = &netlink_ops;
418 sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto);
422 sock_init_data(sock, sk);
426 nlk->cb_mutex = cb_mutex;
428 nlk->cb_mutex = &nlk->cb_def_mutex;
429 mutex_init(nlk->cb_mutex);
431 init_waitqueue_head(&nlk->wait);
433 sk->sk_destruct = netlink_sock_destruct;
434 sk->sk_protocol = protocol;
438 static int netlink_create(struct net *net, struct socket *sock, int protocol,
441 struct module *module = NULL;
442 struct mutex *cb_mutex;
443 struct netlink_sock *nlk;
446 sock->state = SS_UNCONNECTED;
448 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
449 return -ESOCKTNOSUPPORT;
451 if (protocol < 0 || protocol >= MAX_LINKS)
452 return -EPROTONOSUPPORT;
454 netlink_lock_table();
455 #ifdef CONFIG_MODULES
456 if (!nl_table[protocol].registered) {
457 netlink_unlock_table();
458 request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
459 netlink_lock_table();
462 if (nl_table[protocol].registered &&
463 try_module_get(nl_table[protocol].module))
464 module = nl_table[protocol].module;
466 err = -EPROTONOSUPPORT;
467 cb_mutex = nl_table[protocol].cb_mutex;
468 netlink_unlock_table();
473 err = __netlink_create(net, sock, cb_mutex, protocol);
478 sock_prot_inuse_add(net, &netlink_proto, 1);
481 nlk = nlk_sk(sock->sk);
482 nlk->module = module;
491 static int netlink_release(struct socket *sock)
493 struct sock *sk = sock->sk;
494 struct netlink_sock *nlk;
504 * OK. Socket is unlinked, any packets that arrive now
509 wake_up_interruptible_all(&nlk->wait);
511 skb_queue_purge(&sk->sk_write_queue);
514 struct netlink_notify n = {
516 .protocol = sk->sk_protocol,
519 atomic_notifier_call_chain(&netlink_chain,
520 NETLINK_URELEASE, &n);
523 module_put(nlk->module);
525 netlink_table_grab();
526 if (netlink_is_kernel(sk)) {
527 BUG_ON(nl_table[sk->sk_protocol].registered == 0);
528 if (--nl_table[sk->sk_protocol].registered == 0) {
529 struct listeners *old;
531 old = nl_deref_protected(nl_table[sk->sk_protocol].listeners);
532 RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL);
534 nl_table[sk->sk_protocol].module = NULL;
535 nl_table[sk->sk_protocol].registered = 0;
537 } else if (nlk->subscriptions)
538 netlink_update_listeners(sk);
539 netlink_table_ungrab();
545 sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1);
551 static int netlink_autobind(struct socket *sock)
553 struct sock *sk = sock->sk;
554 struct net *net = sock_net(sk);
555 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
556 struct hlist_head *head;
558 struct hlist_node *node;
559 s32 pid = task_tgid_vnr(current);
561 static s32 rover = -4097;
565 netlink_table_grab();
566 head = nl_pid_hashfn(hash, pid);
567 sk_for_each(osk, node, head) {
568 if (!net_eq(sock_net(osk), net))
570 if (nlk_sk(osk)->pid == pid) {
571 /* Bind collision, search negative pid values. */
575 netlink_table_ungrab();
579 netlink_table_ungrab();
581 err = netlink_insert(sk, net, pid);
582 if (err == -EADDRINUSE)
585 /* If 2 threads race to autobind, that is fine. */
592 static inline int netlink_capable(struct socket *sock, unsigned int flag)
594 return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) ||
595 capable(CAP_NET_ADMIN);
599 netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions)
601 struct netlink_sock *nlk = nlk_sk(sk);
603 if (nlk->subscriptions && !subscriptions)
604 __sk_del_bind_node(sk);
605 else if (!nlk->subscriptions && subscriptions)
606 sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
607 nlk->subscriptions = subscriptions;
610 static int netlink_realloc_groups(struct sock *sk)
612 struct netlink_sock *nlk = nlk_sk(sk);
614 unsigned long *new_groups;
617 netlink_table_grab();
619 groups = nl_table[sk->sk_protocol].groups;
620 if (!nl_table[sk->sk_protocol].registered) {
625 if (nlk->ngroups >= groups)
628 new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC);
629 if (new_groups == NULL) {
633 memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0,
634 NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups));
636 nlk->groups = new_groups;
637 nlk->ngroups = groups;
639 netlink_table_ungrab();
643 static int netlink_bind(struct socket *sock, struct sockaddr *addr,
646 struct sock *sk = sock->sk;
647 struct net *net = sock_net(sk);
648 struct netlink_sock *nlk = nlk_sk(sk);
649 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
652 if (nladdr->nl_family != AF_NETLINK)
655 /* Only superuser is allowed to listen multicasts */
656 if (nladdr->nl_groups) {
657 if (!netlink_capable(sock, NL_NONROOT_RECV))
659 err = netlink_realloc_groups(sk);
665 if (nladdr->nl_pid != nlk->pid)
668 err = nladdr->nl_pid ?
669 netlink_insert(sk, net, nladdr->nl_pid) :
670 netlink_autobind(sock);
675 if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
678 netlink_table_grab();
679 netlink_update_subscriptions(sk, nlk->subscriptions +
680 hweight32(nladdr->nl_groups) -
681 hweight32(nlk->groups[0]));
682 nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups;
683 netlink_update_listeners(sk);
684 netlink_table_ungrab();
689 static int netlink_connect(struct socket *sock, struct sockaddr *addr,
693 struct sock *sk = sock->sk;
694 struct netlink_sock *nlk = nlk_sk(sk);
695 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
697 if (alen < sizeof(addr->sa_family))
700 if (addr->sa_family == AF_UNSPEC) {
701 sk->sk_state = NETLINK_UNCONNECTED;
706 if (addr->sa_family != AF_NETLINK)
709 /* Only superuser is allowed to send multicasts */
710 if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND))
714 err = netlink_autobind(sock);
717 sk->sk_state = NETLINK_CONNECTED;
718 nlk->dst_pid = nladdr->nl_pid;
719 nlk->dst_group = ffs(nladdr->nl_groups);
725 static int netlink_getname(struct socket *sock, struct sockaddr *addr,
726 int *addr_len, int peer)
728 struct sock *sk = sock->sk;
729 struct netlink_sock *nlk = nlk_sk(sk);
730 DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr);
732 nladdr->nl_family = AF_NETLINK;
734 *addr_len = sizeof(*nladdr);
737 nladdr->nl_pid = nlk->dst_pid;
738 nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
740 nladdr->nl_pid = nlk->pid;
741 nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
746 static void netlink_overrun(struct sock *sk)
748 struct netlink_sock *nlk = nlk_sk(sk);
750 if (!(nlk->flags & NETLINK_RECV_NO_ENOBUFS)) {
751 if (!test_and_set_bit(0, &nlk_sk(sk)->state)) {
752 sk->sk_err = ENOBUFS;
753 sk->sk_error_report(sk);
756 atomic_inc(&sk->sk_drops);
759 static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid)
762 struct netlink_sock *nlk;
764 sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, pid);
766 return ERR_PTR(-ECONNREFUSED);
768 /* Don't bother queuing skb if kernel socket has no input function */
770 if (sock->sk_state == NETLINK_CONNECTED &&
771 nlk->dst_pid != nlk_sk(ssk)->pid) {
773 return ERR_PTR(-ECONNREFUSED);
778 struct sock *netlink_getsockbyfilp(struct file *filp)
780 struct inode *inode = filp->f_path.dentry->d_inode;
783 if (!S_ISSOCK(inode->i_mode))
784 return ERR_PTR(-ENOTSOCK);
786 sock = SOCKET_I(inode)->sk;
787 if (sock->sk_family != AF_NETLINK)
788 return ERR_PTR(-EINVAL);
795 * Attach a skb to a netlink socket.
796 * The caller must hold a reference to the destination socket. On error, the
797 * reference is dropped. The skb is not send to the destination, just all
798 * all error checks are performed and memory in the queue is reserved.
800 * < 0: error. skb freed, reference to sock dropped.
802 * 1: repeat lookup - reference dropped while waiting for socket memory.
804 int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
805 long *timeo, struct sock *ssk)
807 struct netlink_sock *nlk;
811 if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
812 test_bit(0, &nlk->state)) {
813 DECLARE_WAITQUEUE(wait, current);
815 if (!ssk || netlink_is_kernel(ssk))
822 __set_current_state(TASK_INTERRUPTIBLE);
823 add_wait_queue(&nlk->wait, &wait);
825 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
826 test_bit(0, &nlk->state)) &&
827 !sock_flag(sk, SOCK_DEAD))
828 *timeo = schedule_timeout(*timeo);
830 __set_current_state(TASK_RUNNING);
831 remove_wait_queue(&nlk->wait, &wait);
834 if (signal_pending(current)) {
836 return sock_intr_errno(*timeo);
840 skb_set_owner_r(skb, sk);
844 static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb)
848 skb_queue_tail(&sk->sk_receive_queue, skb);
849 sk->sk_data_ready(sk, len);
853 int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
855 int len = __netlink_sendskb(sk, skb);
861 void netlink_detachskb(struct sock *sk, struct sk_buff *skb)
867 static inline struct sk_buff *netlink_trim(struct sk_buff *skb,
874 delta = skb->end - skb->tail;
875 if (delta * 2 < skb->truesize)
878 if (skb_shared(skb)) {
879 struct sk_buff *nskb = skb_clone(skb, allocation);
886 if (!pskb_expand_head(skb, 0, -delta, allocation))
887 skb->truesize -= delta;
892 static inline void netlink_rcv_wake(struct sock *sk)
894 struct netlink_sock *nlk = nlk_sk(sk);
896 if (skb_queue_empty(&sk->sk_receive_queue))
897 clear_bit(0, &nlk->state);
898 if (!test_bit(0, &nlk->state))
899 wake_up_interruptible(&nlk->wait);
902 static inline int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb)
905 struct netlink_sock *nlk = nlk_sk(sk);
908 if (nlk->netlink_rcv != NULL) {
910 skb_set_owner_r(skb, sk);
911 nlk->netlink_rcv(skb);
918 int netlink_unicast(struct sock *ssk, struct sk_buff *skb,
919 u32 pid, int nonblock)
925 skb = netlink_trim(skb, gfp_any());
927 timeo = sock_sndtimeo(ssk, nonblock);
929 sk = netlink_getsockbypid(ssk, pid);
934 if (netlink_is_kernel(sk))
935 return netlink_unicast_kernel(sk, skb);
937 if (sk_filter(sk, skb)) {
944 err = netlink_attachskb(sk, skb, &timeo, ssk);
950 return netlink_sendskb(sk, skb);
952 EXPORT_SYMBOL(netlink_unicast);
954 int netlink_has_listeners(struct sock *sk, unsigned int group)
957 struct listeners *listeners;
959 BUG_ON(!netlink_is_kernel(sk));
962 listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners);
964 if (listeners && group - 1 < nl_table[sk->sk_protocol].groups)
965 res = test_bit(group - 1, listeners->masks);
971 EXPORT_SYMBOL_GPL(netlink_has_listeners);
973 static inline int netlink_broadcast_deliver(struct sock *sk,
976 struct netlink_sock *nlk = nlk_sk(sk);
978 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
979 !test_bit(0, &nlk->state)) {
980 skb_set_owner_r(skb, sk);
981 __netlink_sendskb(sk, skb);
982 return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf;
987 struct netlink_broadcast_data {
988 struct sock *exclude_sk;
993 int delivery_failure;
997 struct sk_buff *skb, *skb2;
998 int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data);
1002 static inline int do_one_broadcast(struct sock *sk,
1003 struct netlink_broadcast_data *p)
1005 struct netlink_sock *nlk = nlk_sk(sk);
1008 if (p->exclude_sk == sk)
1011 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
1012 !test_bit(p->group - 1, nlk->groups))
1015 if (!net_eq(sock_net(sk), p->net))
1019 netlink_overrun(sk);
1024 if (p->skb2 == NULL) {
1025 if (skb_shared(p->skb)) {
1026 p->skb2 = skb_clone(p->skb, p->allocation);
1028 p->skb2 = skb_get(p->skb);
1030 * skb ownership may have been set when
1031 * delivered to a previous socket.
1033 skb_orphan(p->skb2);
1036 if (p->skb2 == NULL) {
1037 netlink_overrun(sk);
1038 /* Clone failed. Notify ALL listeners. */
1040 if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR)
1041 p->delivery_failure = 1;
1042 } else if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) {
1045 } else if (sk_filter(sk, p->skb2)) {
1048 } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) {
1049 netlink_overrun(sk);
1050 if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR)
1051 p->delivery_failure = 1;
1053 p->congested |= val;
1063 int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 pid,
1064 u32 group, gfp_t allocation,
1065 int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
1068 struct net *net = sock_net(ssk);
1069 struct netlink_broadcast_data info;
1070 struct hlist_node *node;
1073 skb = netlink_trim(skb, allocation);
1075 info.exclude_sk = ssk;
1080 info.delivery_failure = 0;
1083 info.allocation = allocation;
1086 info.tx_filter = filter;
1087 info.tx_data = filter_data;
1089 /* While we sleep in clone, do not allow to change socket list */
1091 netlink_lock_table();
1093 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
1094 do_one_broadcast(sk, &info);
1098 netlink_unlock_table();
1100 if (info.delivery_failure) {
1101 kfree_skb(info.skb2);
1104 consume_skb(info.skb2);
1106 if (info.delivered) {
1107 if (info.congested && (allocation & __GFP_WAIT))
1113 EXPORT_SYMBOL(netlink_broadcast_filtered);
1115 int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
1116 u32 group, gfp_t allocation)
1118 return netlink_broadcast_filtered(ssk, skb, pid, group, allocation,
1121 EXPORT_SYMBOL(netlink_broadcast);
1123 struct netlink_set_err_data {
1124 struct sock *exclude_sk;
1130 static inline int do_one_set_err(struct sock *sk,
1131 struct netlink_set_err_data *p)
1133 struct netlink_sock *nlk = nlk_sk(sk);
1136 if (sk == p->exclude_sk)
1139 if (!net_eq(sock_net(sk), sock_net(p->exclude_sk)))
1142 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
1143 !test_bit(p->group - 1, nlk->groups))
1146 if (p->code == ENOBUFS && nlk->flags & NETLINK_RECV_NO_ENOBUFS) {
1151 sk->sk_err = p->code;
1152 sk->sk_error_report(sk);
1158 * netlink_set_err - report error to broadcast listeners
1159 * @ssk: the kernel netlink socket, as returned by netlink_kernel_create()
1160 * @pid: the PID of a process that we want to skip (if any)
1161 * @groups: the broadcast group that will notice the error
1162 * @code: error code, must be negative (as usual in kernelspace)
1164 * This function returns the number of broadcast listeners that have set the
1165 * NETLINK_RECV_NO_ENOBUFS socket option.
1167 int netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code)
1169 struct netlink_set_err_data info;
1170 struct hlist_node *node;
1174 info.exclude_sk = ssk;
1177 /* sk->sk_err wants a positive error value */
1180 read_lock(&nl_table_lock);
1182 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
1183 ret += do_one_set_err(sk, &info);
1185 read_unlock(&nl_table_lock);
1188 EXPORT_SYMBOL(netlink_set_err);
1190 /* must be called with netlink table grabbed */
1191 static void netlink_update_socket_mc(struct netlink_sock *nlk,
1195 int old, new = !!is_new, subscriptions;
1197 old = test_bit(group - 1, nlk->groups);
1198 subscriptions = nlk->subscriptions - old + new;
1200 __set_bit(group - 1, nlk->groups);
1202 __clear_bit(group - 1, nlk->groups);
1203 netlink_update_subscriptions(&nlk->sk, subscriptions);
1204 netlink_update_listeners(&nlk->sk);
1207 static int netlink_setsockopt(struct socket *sock, int level, int optname,
1208 char __user *optval, unsigned int optlen)
1210 struct sock *sk = sock->sk;
1211 struct netlink_sock *nlk = nlk_sk(sk);
1212 unsigned int val = 0;
1215 if (level != SOL_NETLINK)
1216 return -ENOPROTOOPT;
1218 if (optlen >= sizeof(int) &&
1219 get_user(val, (unsigned int __user *)optval))
1223 case NETLINK_PKTINFO:
1225 nlk->flags |= NETLINK_RECV_PKTINFO;
1227 nlk->flags &= ~NETLINK_RECV_PKTINFO;
1230 case NETLINK_ADD_MEMBERSHIP:
1231 case NETLINK_DROP_MEMBERSHIP: {
1232 if (!netlink_capable(sock, NL_NONROOT_RECV))
1234 err = netlink_realloc_groups(sk);
1237 if (!val || val - 1 >= nlk->ngroups)
1239 netlink_table_grab();
1240 netlink_update_socket_mc(nlk, val,
1241 optname == NETLINK_ADD_MEMBERSHIP);
1242 netlink_table_ungrab();
1246 case NETLINK_BROADCAST_ERROR:
1248 nlk->flags |= NETLINK_BROADCAST_SEND_ERROR;
1250 nlk->flags &= ~NETLINK_BROADCAST_SEND_ERROR;
1253 case NETLINK_NO_ENOBUFS:
1255 nlk->flags |= NETLINK_RECV_NO_ENOBUFS;
1256 clear_bit(0, &nlk->state);
1257 wake_up_interruptible(&nlk->wait);
1259 nlk->flags &= ~NETLINK_RECV_NO_ENOBUFS;
1268 static int netlink_getsockopt(struct socket *sock, int level, int optname,
1269 char __user *optval, int __user *optlen)
1271 struct sock *sk = sock->sk;
1272 struct netlink_sock *nlk = nlk_sk(sk);
1275 if (level != SOL_NETLINK)
1276 return -ENOPROTOOPT;
1278 if (get_user(len, optlen))
1284 case NETLINK_PKTINFO:
1285 if (len < sizeof(int))
1288 val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0;
1289 if (put_user(len, optlen) ||
1290 put_user(val, optval))
1294 case NETLINK_BROADCAST_ERROR:
1295 if (len < sizeof(int))
1298 val = nlk->flags & NETLINK_BROADCAST_SEND_ERROR ? 1 : 0;
1299 if (put_user(len, optlen) ||
1300 put_user(val, optval))
1304 case NETLINK_NO_ENOBUFS:
1305 if (len < sizeof(int))
1308 val = nlk->flags & NETLINK_RECV_NO_ENOBUFS ? 1 : 0;
1309 if (put_user(len, optlen) ||
1310 put_user(val, optval))
1320 static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
1322 struct nl_pktinfo info;
1324 info.group = NETLINK_CB(skb).dst_group;
1325 put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info);
1328 static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
1329 struct msghdr *msg, size_t len)
1331 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1332 struct sock *sk = sock->sk;
1333 struct netlink_sock *nlk = nlk_sk(sk);
1334 struct sockaddr_nl *addr = msg->msg_name;
1337 struct sk_buff *skb;
1339 struct scm_cookie scm;
1341 if (msg->msg_flags&MSG_OOB)
1344 if (NULL == siocb->scm)
1347 err = scm_send(sock, msg, siocb->scm, true);
1351 if (msg->msg_namelen) {
1353 if (addr->nl_family != AF_NETLINK)
1355 dst_pid = addr->nl_pid;
1356 dst_group = ffs(addr->nl_groups);
1358 if ((dst_group || dst_pid) &&
1359 !netlink_capable(sock, NL_NONROOT_SEND))
1362 dst_pid = nlk->dst_pid;
1363 dst_group = nlk->dst_group;
1367 err = netlink_autobind(sock);
1373 if (len > sk->sk_sndbuf - 32)
1376 skb = alloc_skb(len, GFP_KERNEL);
1380 NETLINK_CB(skb).pid = nlk->pid;
1381 NETLINK_CB(skb).dst_group = dst_group;
1382 memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1385 if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
1390 err = security_netlink_send(sk, skb);
1397 atomic_inc(&skb->users);
1398 netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL);
1400 err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT);
1403 scm_destroy(siocb->scm);
1407 static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
1408 struct msghdr *msg, size_t len,
1411 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1412 struct scm_cookie scm;
1413 struct sock *sk = sock->sk;
1414 struct netlink_sock *nlk = nlk_sk(sk);
1415 int noblock = flags&MSG_DONTWAIT;
1417 struct sk_buff *skb, *data_skb;
1425 skb = skb_recv_datagram(sk, flags, noblock, &err);
1431 #ifdef CONFIG_COMPAT_NETLINK_MESSAGES
1432 if (unlikely(skb_shinfo(skb)->frag_list)) {
1434 * If this skb has a frag_list, then here that means that we
1435 * will have to use the frag_list skb's data for compat tasks
1436 * and the regular skb's data for normal (non-compat) tasks.
1438 * If we need to send the compat skb, assign it to the
1439 * 'data_skb' variable so that it will be used below for data
1440 * copying. We keep 'skb' for everything else, including
1441 * freeing both later.
1443 if (flags & MSG_CMSG_COMPAT)
1444 data_skb = skb_shinfo(skb)->frag_list;
1448 msg->msg_namelen = 0;
1450 copied = data_skb->len;
1452 msg->msg_flags |= MSG_TRUNC;
1456 skb_reset_transport_header(data_skb);
1457 err = skb_copy_datagram_iovec(data_skb, 0, msg->msg_iov, copied);
1459 if (msg->msg_name) {
1460 struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name;
1461 addr->nl_family = AF_NETLINK;
1463 addr->nl_pid = NETLINK_CB(skb).pid;
1464 addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group);
1465 msg->msg_namelen = sizeof(*addr);
1468 if (nlk->flags & NETLINK_RECV_PKTINFO)
1469 netlink_cmsg_recv_pktinfo(msg, skb);
1471 if (NULL == siocb->scm) {
1472 memset(&scm, 0, sizeof(scm));
1475 siocb->scm->creds = *NETLINK_CREDS(skb);
1476 if (flags & MSG_TRUNC)
1477 copied = data_skb->len;
1479 skb_free_datagram(sk, skb);
1481 if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) {
1482 ret = netlink_dump(sk);
1485 sk->sk_error_report(sk);
1489 scm_recv(sock, msg, siocb->scm, flags);
1491 netlink_rcv_wake(sk);
1492 return err ? : copied;
1495 static void netlink_data_ready(struct sock *sk, int len)
1501 * We export these functions to other modules. They provide a
1502 * complete set of kernel non-blocking support for message
1507 netlink_kernel_create(struct net *net, int unit, unsigned int groups,
1508 void (*input)(struct sk_buff *skb),
1509 struct mutex *cb_mutex, struct module *module)
1511 struct socket *sock;
1513 struct netlink_sock *nlk;
1514 struct listeners *listeners = NULL;
1518 if (unit < 0 || unit >= MAX_LINKS)
1521 if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
1525 * We have to just have a reference on the net from sk, but don't
1526 * get_net it. Besides, we cannot get and then put the net here.
1527 * So we create one inside init_net and the move it to net.
1530 if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0)
1531 goto out_sock_release_nosk;
1534 sk_change_net(sk, net);
1539 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
1541 goto out_sock_release;
1543 sk->sk_data_ready = netlink_data_ready;
1545 nlk_sk(sk)->netlink_rcv = input;
1547 if (netlink_insert(sk, net, 0))
1548 goto out_sock_release;
1551 nlk->flags |= NETLINK_KERNEL_SOCKET;
1553 netlink_table_grab();
1554 if (!nl_table[unit].registered) {
1555 nl_table[unit].groups = groups;
1556 rcu_assign_pointer(nl_table[unit].listeners, listeners);
1557 nl_table[unit].cb_mutex = cb_mutex;
1558 nl_table[unit].module = module;
1559 nl_table[unit].registered = 1;
1562 nl_table[unit].registered++;
1564 netlink_table_ungrab();
1569 netlink_kernel_release(sk);
1572 out_sock_release_nosk:
1576 EXPORT_SYMBOL(netlink_kernel_create);
1580 netlink_kernel_release(struct sock *sk)
1582 sk_release_kernel(sk);
1584 EXPORT_SYMBOL(netlink_kernel_release);
1586 int __netlink_change_ngroups(struct sock *sk, unsigned int groups)
1588 struct listeners *new, *old;
1589 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
1594 if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) {
1595 new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC);
1598 old = nl_deref_protected(tbl->listeners);
1599 memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups));
1600 rcu_assign_pointer(tbl->listeners, new);
1602 kfree_rcu(old, rcu);
1604 tbl->groups = groups;
1610 * netlink_change_ngroups - change number of multicast groups
1612 * This changes the number of multicast groups that are available
1613 * on a certain netlink family. Note that it is not possible to
1614 * change the number of groups to below 32. Also note that it does
1615 * not implicitly call netlink_clear_multicast_users() when the
1616 * number of groups is reduced.
1618 * @sk: The kernel netlink socket, as returned by netlink_kernel_create().
1619 * @groups: The new number of groups.
1621 int netlink_change_ngroups(struct sock *sk, unsigned int groups)
1625 netlink_table_grab();
1626 err = __netlink_change_ngroups(sk, groups);
1627 netlink_table_ungrab();
1632 void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
1635 struct hlist_node *node;
1636 struct netlink_table *tbl = &nl_table[ksk->sk_protocol];
1638 sk_for_each_bound(sk, node, &tbl->mc_list)
1639 netlink_update_socket_mc(nlk_sk(sk), group, 0);
1643 * netlink_clear_multicast_users - kick off multicast listeners
1645 * This function removes all listeners from the given group.
1646 * @ksk: The kernel netlink socket, as returned by
1647 * netlink_kernel_create().
1648 * @group: The multicast group to clear.
1650 void netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
1652 netlink_table_grab();
1653 __netlink_clear_multicast_users(ksk, group);
1654 netlink_table_ungrab();
1657 void netlink_set_nonroot(int protocol, unsigned int flags)
1659 if ((unsigned int)protocol < MAX_LINKS)
1660 nl_table[protocol].nl_nonroot = flags;
1662 EXPORT_SYMBOL(netlink_set_nonroot);
1664 static void netlink_destroy_callback(struct netlink_callback *cb)
1671 * It looks a bit ugly.
1672 * It would be better to create kernel thread.
1675 static int netlink_dump(struct sock *sk)
1677 struct netlink_sock *nlk = nlk_sk(sk);
1678 struct netlink_callback *cb;
1679 struct sk_buff *skb = NULL;
1680 struct nlmsghdr *nlh;
1681 int len, err = -ENOBUFS;
1684 mutex_lock(nlk->cb_mutex);
1692 alloc_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE);
1694 skb = sock_rmalloc(sk, alloc_size, 0, GFP_KERNEL);
1698 len = cb->dump(skb, cb);
1701 mutex_unlock(nlk->cb_mutex);
1703 if (sk_filter(sk, skb))
1706 __netlink_sendskb(sk, skb);
1710 nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI);
1714 nl_dump_check_consistent(cb, nlh);
1716 memcpy(nlmsg_data(nlh), &len, sizeof(len));
1718 if (sk_filter(sk, skb))
1721 __netlink_sendskb(sk, skb);
1726 mutex_unlock(nlk->cb_mutex);
1728 netlink_destroy_callback(cb);
1732 mutex_unlock(nlk->cb_mutex);
1737 int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
1738 const struct nlmsghdr *nlh,
1739 int (*dump)(struct sk_buff *skb,
1740 struct netlink_callback *),
1741 int (*done)(struct netlink_callback *),
1744 struct netlink_callback *cb;
1746 struct netlink_sock *nlk;
1749 cb = kzalloc(sizeof(*cb), GFP_KERNEL);
1756 cb->min_dump_alloc = min_dump_alloc;
1757 atomic_inc(&skb->users);
1760 sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).pid);
1762 netlink_destroy_callback(cb);
1763 return -ECONNREFUSED;
1766 /* A dump is in progress... */
1767 mutex_lock(nlk->cb_mutex);
1769 mutex_unlock(nlk->cb_mutex);
1770 netlink_destroy_callback(cb);
1775 mutex_unlock(nlk->cb_mutex);
1777 ret = netlink_dump(sk);
1784 /* We successfully started a dump, by returning -EINTR we
1785 * signal not to send ACK even if it was requested.
1789 EXPORT_SYMBOL(netlink_dump_start);
1791 void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
1793 struct sk_buff *skb;
1794 struct nlmsghdr *rep;
1795 struct nlmsgerr *errmsg;
1796 size_t payload = sizeof(*errmsg);
1798 /* error messages get the original request appened */
1800 payload += nlmsg_len(nlh);
1802 skb = nlmsg_new(payload, GFP_KERNEL);
1806 sk = netlink_lookup(sock_net(in_skb->sk),
1807 in_skb->sk->sk_protocol,
1808 NETLINK_CB(in_skb).pid);
1810 sk->sk_err = ENOBUFS;
1811 sk->sk_error_report(sk);
1817 rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
1818 NLMSG_ERROR, payload, 0);
1819 errmsg = nlmsg_data(rep);
1820 errmsg->error = err;
1821 memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh));
1822 netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
1824 EXPORT_SYMBOL(netlink_ack);
1826 int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
1829 struct nlmsghdr *nlh;
1832 while (skb->len >= nlmsg_total_size(0)) {
1835 nlh = nlmsg_hdr(skb);
1838 if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
1841 /* Only requests are handled by the kernel */
1842 if (!(nlh->nlmsg_flags & NLM_F_REQUEST))
1845 /* Skip control messages */
1846 if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
1854 if (nlh->nlmsg_flags & NLM_F_ACK || err)
1855 netlink_ack(skb, nlh, err);
1858 msglen = NLMSG_ALIGN(nlh->nlmsg_len);
1859 if (msglen > skb->len)
1861 skb_pull(skb, msglen);
1866 EXPORT_SYMBOL(netlink_rcv_skb);
1869 * nlmsg_notify - send a notification netlink message
1870 * @sk: netlink socket to use
1871 * @skb: notification message
1872 * @pid: destination netlink pid for reports or 0
1873 * @group: destination multicast group or 0
1874 * @report: 1 to report back, 0 to disable
1875 * @flags: allocation flags
1877 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid,
1878 unsigned int group, int report, gfp_t flags)
1883 int exclude_pid = 0;
1886 atomic_inc(&skb->users);
1890 /* errors reported via destination sk->sk_err, but propagate
1891 * delivery errors if NETLINK_BROADCAST_ERROR flag is set */
1892 err = nlmsg_multicast(sk, skb, exclude_pid, group, flags);
1898 err2 = nlmsg_unicast(sk, skb, pid);
1899 if (!err || err == -ESRCH)
1905 EXPORT_SYMBOL(nlmsg_notify);
1907 #ifdef CONFIG_PROC_FS
1908 struct nl_seq_iter {
1909 struct seq_net_private p;
1914 static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos)
1916 struct nl_seq_iter *iter = seq->private;
1919 struct hlist_node *node;
1922 for (i = 0; i < MAX_LINKS; i++) {
1923 struct nl_pid_hash *hash = &nl_table[i].hash;
1925 for (j = 0; j <= hash->mask; j++) {
1926 sk_for_each(s, node, &hash->table[j]) {
1927 if (sock_net(s) != seq_file_net(seq))
1941 static void *netlink_seq_start(struct seq_file *seq, loff_t *pos)
1942 __acquires(nl_table_lock)
1944 read_lock(&nl_table_lock);
1945 return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN;
1948 static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1951 struct nl_seq_iter *iter;
1956 if (v == SEQ_START_TOKEN)
1957 return netlink_seq_socket_idx(seq, 0);
1959 iter = seq->private;
1963 } while (s && sock_net(s) != seq_file_net(seq));
1968 j = iter->hash_idx + 1;
1971 struct nl_pid_hash *hash = &nl_table[i].hash;
1973 for (; j <= hash->mask; j++) {
1974 s = sk_head(&hash->table[j]);
1975 while (s && sock_net(s) != seq_file_net(seq))
1985 } while (++i < MAX_LINKS);
1990 static void netlink_seq_stop(struct seq_file *seq, void *v)
1991 __releases(nl_table_lock)
1993 read_unlock(&nl_table_lock);
1997 static int netlink_seq_show(struct seq_file *seq, void *v)
1999 if (v == SEQ_START_TOKEN)
2001 "sk Eth Pid Groups "
2002 "Rmem Wmem Dump Locks Drops Inode\n");
2005 struct netlink_sock *nlk = nlk_sk(s);
2007 seq_printf(seq, "%pK %-3d %-6d %08x %-8d %-8d %pK %-8d %-8d %-8lu\n",
2011 nlk->groups ? (u32)nlk->groups[0] : 0,
2012 sk_rmem_alloc_get(s),
2013 sk_wmem_alloc_get(s),
2015 atomic_read(&s->sk_refcnt),
2016 atomic_read(&s->sk_drops),
2024 static const struct seq_operations netlink_seq_ops = {
2025 .start = netlink_seq_start,
2026 .next = netlink_seq_next,
2027 .stop = netlink_seq_stop,
2028 .show = netlink_seq_show,
2032 static int netlink_seq_open(struct inode *inode, struct file *file)
2034 return seq_open_net(inode, file, &netlink_seq_ops,
2035 sizeof(struct nl_seq_iter));
2038 static const struct file_operations netlink_seq_fops = {
2039 .owner = THIS_MODULE,
2040 .open = netlink_seq_open,
2042 .llseek = seq_lseek,
2043 .release = seq_release_net,
2048 int netlink_register_notifier(struct notifier_block *nb)
2050 return atomic_notifier_chain_register(&netlink_chain, nb);
2052 EXPORT_SYMBOL(netlink_register_notifier);
2054 int netlink_unregister_notifier(struct notifier_block *nb)
2056 return atomic_notifier_chain_unregister(&netlink_chain, nb);
2058 EXPORT_SYMBOL(netlink_unregister_notifier);
2060 static const struct proto_ops netlink_ops = {
2061 .family = PF_NETLINK,
2062 .owner = THIS_MODULE,
2063 .release = netlink_release,
2064 .bind = netlink_bind,
2065 .connect = netlink_connect,
2066 .socketpair = sock_no_socketpair,
2067 .accept = sock_no_accept,
2068 .getname = netlink_getname,
2069 .poll = datagram_poll,
2070 .ioctl = sock_no_ioctl,
2071 .listen = sock_no_listen,
2072 .shutdown = sock_no_shutdown,
2073 .setsockopt = netlink_setsockopt,
2074 .getsockopt = netlink_getsockopt,
2075 .sendmsg = netlink_sendmsg,
2076 .recvmsg = netlink_recvmsg,
2077 .mmap = sock_no_mmap,
2078 .sendpage = sock_no_sendpage,
2081 static const struct net_proto_family netlink_family_ops = {
2082 .family = PF_NETLINK,
2083 .create = netlink_create,
2084 .owner = THIS_MODULE, /* for consistency 8) */
2087 static int __net_init netlink_net_init(struct net *net)
2089 #ifdef CONFIG_PROC_FS
2090 if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops))
2096 static void __net_exit netlink_net_exit(struct net *net)
2098 #ifdef CONFIG_PROC_FS
2099 proc_net_remove(net, "netlink");
2103 static void __init netlink_add_usersock_entry(void)
2105 struct listeners *listeners;
2108 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
2110 panic("netlink_add_usersock_entry: Cannot allocate listeners\n");
2112 netlink_table_grab();
2114 nl_table[NETLINK_USERSOCK].groups = groups;
2115 rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners);
2116 nl_table[NETLINK_USERSOCK].module = THIS_MODULE;
2117 nl_table[NETLINK_USERSOCK].registered = 1;
2118 nl_table[NETLINK_USERSOCK].nl_nonroot = NL_NONROOT_SEND;
2120 netlink_table_ungrab();
2123 static struct pernet_operations __net_initdata netlink_net_ops = {
2124 .init = netlink_net_init,
2125 .exit = netlink_net_exit,
2128 static int __init netlink_proto_init(void)
2130 struct sk_buff *dummy_skb;
2132 unsigned long limit;
2134 int err = proto_register(&netlink_proto, 0);
2139 BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb));
2141 nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);
2145 if (totalram_pages >= (128 * 1024))
2146 limit = totalram_pages >> (21 - PAGE_SHIFT);
2148 limit = totalram_pages >> (23 - PAGE_SHIFT);
2150 order = get_bitmask_order(limit) - 1 + PAGE_SHIFT;
2151 limit = (1UL << order) / sizeof(struct hlist_head);
2152 order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1;
2154 for (i = 0; i < MAX_LINKS; i++) {
2155 struct nl_pid_hash *hash = &nl_table[i].hash;
2157 hash->table = nl_pid_hash_zalloc(1 * sizeof(*hash->table));
2160 nl_pid_hash_free(nl_table[i].hash.table,
2161 1 * sizeof(*hash->table));
2165 hash->max_shift = order;
2168 hash->rehash_time = jiffies;
2171 netlink_add_usersock_entry();
2173 sock_register(&netlink_family_ops);
2174 register_pernet_subsys(&netlink_net_ops);
2175 /* The netlink device handler may be needed early. */
2180 panic("netlink_init: Cannot allocate nl_table\n");
2183 core_initcall(netlink_proto_init);