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 void (*netlink_bind)(int group);
84 struct module *module;
89 unsigned long masks[0];
92 #define NETLINK_KERNEL_SOCKET 0x1
93 #define NETLINK_RECV_PKTINFO 0x2
94 #define NETLINK_BROADCAST_SEND_ERROR 0x4
95 #define NETLINK_RECV_NO_ENOBUFS 0x8
97 static inline struct netlink_sock *nlk_sk(struct sock *sk)
99 return container_of(sk, struct netlink_sock, sk);
102 static inline int netlink_is_kernel(struct sock *sk)
104 return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET;
107 struct nl_portid_hash {
108 struct hlist_head *table;
109 unsigned long rehash_time;
114 unsigned int entries;
115 unsigned int max_shift;
120 struct netlink_table {
121 struct nl_portid_hash hash;
122 struct hlist_head mc_list;
123 struct listeners __rcu *listeners;
126 struct mutex *cb_mutex;
127 struct module *module;
128 void (*bind)(int group);
132 static struct netlink_table *nl_table;
134 static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
136 static int netlink_dump(struct sock *sk);
138 static DEFINE_RWLOCK(nl_table_lock);
139 static atomic_t nl_table_users = ATOMIC_INIT(0);
141 #define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock));
143 static ATOMIC_NOTIFIER_HEAD(netlink_chain);
145 static inline u32 netlink_group_mask(u32 group)
147 return group ? 1 << (group - 1) : 0;
150 static inline struct hlist_head *nl_portid_hashfn(struct nl_portid_hash *hash, u32 portid)
152 return &hash->table[jhash_1word(portid, hash->rnd) & hash->mask];
155 static void netlink_destroy_callback(struct netlink_callback *cb)
161 static void netlink_consume_callback(struct netlink_callback *cb)
163 consume_skb(cb->skb);
167 static void netlink_sock_destruct(struct sock *sk)
169 struct netlink_sock *nlk = nlk_sk(sk);
173 nlk->cb->done(nlk->cb);
175 module_put(nlk->cb->module);
176 netlink_destroy_callback(nlk->cb);
179 skb_queue_purge(&sk->sk_receive_queue);
181 if (!sock_flag(sk, SOCK_DEAD)) {
182 printk(KERN_ERR "Freeing alive netlink socket %p\n", sk);
186 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
187 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
188 WARN_ON(nlk_sk(sk)->groups);
191 /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on
192 * SMP. Look, when several writers sleep and reader wakes them up, all but one
193 * immediately hit write lock and grab all the cpus. Exclusive sleep solves
194 * this, _but_ remember, it adds useless work on UP machines.
197 void netlink_table_grab(void)
198 __acquires(nl_table_lock)
202 write_lock_irq(&nl_table_lock);
204 if (atomic_read(&nl_table_users)) {
205 DECLARE_WAITQUEUE(wait, current);
207 add_wait_queue_exclusive(&nl_table_wait, &wait);
209 set_current_state(TASK_UNINTERRUPTIBLE);
210 if (atomic_read(&nl_table_users) == 0)
212 write_unlock_irq(&nl_table_lock);
214 write_lock_irq(&nl_table_lock);
217 __set_current_state(TASK_RUNNING);
218 remove_wait_queue(&nl_table_wait, &wait);
222 void netlink_table_ungrab(void)
223 __releases(nl_table_lock)
225 write_unlock_irq(&nl_table_lock);
226 wake_up(&nl_table_wait);
230 netlink_lock_table(void)
232 /* read_lock() synchronizes us to netlink_table_grab */
234 read_lock(&nl_table_lock);
235 atomic_inc(&nl_table_users);
236 read_unlock(&nl_table_lock);
240 netlink_unlock_table(void)
242 if (atomic_dec_and_test(&nl_table_users))
243 wake_up(&nl_table_wait);
246 static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid)
248 struct nl_portid_hash *hash = &nl_table[protocol].hash;
249 struct hlist_head *head;
251 struct hlist_node *node;
253 read_lock(&nl_table_lock);
254 head = nl_portid_hashfn(hash, portid);
255 sk_for_each(sk, node, head) {
256 if (net_eq(sock_net(sk), net) && (nlk_sk(sk)->portid == portid)) {
263 read_unlock(&nl_table_lock);
267 static struct hlist_head *nl_portid_hash_zalloc(size_t size)
269 if (size <= PAGE_SIZE)
270 return kzalloc(size, GFP_ATOMIC);
272 return (struct hlist_head *)
273 __get_free_pages(GFP_ATOMIC | __GFP_ZERO,
277 static void nl_portid_hash_free(struct hlist_head *table, size_t size)
279 if (size <= PAGE_SIZE)
282 free_pages((unsigned long)table, get_order(size));
285 static int nl_portid_hash_rehash(struct nl_portid_hash *hash, int grow)
287 unsigned int omask, mask, shift;
289 struct hlist_head *otable, *table;
292 omask = mask = hash->mask;
293 osize = size = (mask + 1) * sizeof(*table);
297 if (++shift > hash->max_shift)
303 table = nl_portid_hash_zalloc(size);
307 otable = hash->table;
311 get_random_bytes(&hash->rnd, sizeof(hash->rnd));
313 for (i = 0; i <= omask; i++) {
315 struct hlist_node *node, *tmp;
317 sk_for_each_safe(sk, node, tmp, &otable[i])
318 __sk_add_node(sk, nl_portid_hashfn(hash, nlk_sk(sk)->portid));
321 nl_portid_hash_free(otable, osize);
322 hash->rehash_time = jiffies + 10 * 60 * HZ;
326 static inline int nl_portid_hash_dilute(struct nl_portid_hash *hash, int len)
328 int avg = hash->entries >> hash->shift;
330 if (unlikely(avg > 1) && nl_portid_hash_rehash(hash, 1))
333 if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) {
334 nl_portid_hash_rehash(hash, 0);
341 static const struct proto_ops netlink_ops;
344 netlink_update_listeners(struct sock *sk)
346 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
347 struct hlist_node *node;
350 struct listeners *listeners;
352 listeners = nl_deref_protected(tbl->listeners);
356 for (i = 0; i < NLGRPLONGS(tbl->groups); i++) {
358 sk_for_each_bound(sk, node, &tbl->mc_list) {
359 if (i < NLGRPLONGS(nlk_sk(sk)->ngroups))
360 mask |= nlk_sk(sk)->groups[i];
362 listeners->masks[i] = mask;
364 /* this function is only called with the netlink table "grabbed", which
365 * makes sure updates are visible before bind or setsockopt return. */
368 static int netlink_insert(struct sock *sk, struct net *net, u32 portid)
370 struct nl_portid_hash *hash = &nl_table[sk->sk_protocol].hash;
371 struct hlist_head *head;
372 int err = -EADDRINUSE;
374 struct hlist_node *node;
377 netlink_table_grab();
378 head = nl_portid_hashfn(hash, portid);
380 sk_for_each(osk, node, head) {
381 if (net_eq(sock_net(osk), net) && (nlk_sk(osk)->portid == portid))
389 if (nlk_sk(sk)->portid)
393 if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX))
396 if (len && nl_portid_hash_dilute(hash, len))
397 head = nl_portid_hashfn(hash, portid);
399 nlk_sk(sk)->portid = portid;
400 sk_add_node(sk, head);
404 netlink_table_ungrab();
408 static void netlink_remove(struct sock *sk)
410 netlink_table_grab();
411 if (sk_del_node_init(sk))
412 nl_table[sk->sk_protocol].hash.entries--;
413 if (nlk_sk(sk)->subscriptions)
414 __sk_del_bind_node(sk);
415 netlink_table_ungrab();
418 static struct proto netlink_proto = {
420 .owner = THIS_MODULE,
421 .obj_size = sizeof(struct netlink_sock),
424 static int __netlink_create(struct net *net, struct socket *sock,
425 struct mutex *cb_mutex, int protocol)
428 struct netlink_sock *nlk;
430 sock->ops = &netlink_ops;
432 sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto);
436 sock_init_data(sock, sk);
440 nlk->cb_mutex = cb_mutex;
442 nlk->cb_mutex = &nlk->cb_def_mutex;
443 mutex_init(nlk->cb_mutex);
445 init_waitqueue_head(&nlk->wait);
447 sk->sk_destruct = netlink_sock_destruct;
448 sk->sk_protocol = protocol;
452 static int netlink_create(struct net *net, struct socket *sock, int protocol,
455 struct module *module = NULL;
456 struct mutex *cb_mutex;
457 struct netlink_sock *nlk;
458 void (*bind)(int group);
461 sock->state = SS_UNCONNECTED;
463 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
464 return -ESOCKTNOSUPPORT;
466 if (protocol < 0 || protocol >= MAX_LINKS)
467 return -EPROTONOSUPPORT;
469 netlink_lock_table();
470 #ifdef CONFIG_MODULES
471 if (!nl_table[protocol].registered) {
472 netlink_unlock_table();
473 request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
474 netlink_lock_table();
477 if (nl_table[protocol].registered &&
478 try_module_get(nl_table[protocol].module))
479 module = nl_table[protocol].module;
481 err = -EPROTONOSUPPORT;
482 cb_mutex = nl_table[protocol].cb_mutex;
483 bind = nl_table[protocol].bind;
484 netlink_unlock_table();
489 err = __netlink_create(net, sock, cb_mutex, protocol);
494 sock_prot_inuse_add(net, &netlink_proto, 1);
497 nlk = nlk_sk(sock->sk);
498 nlk->module = module;
499 nlk->netlink_bind = bind;
508 static int netlink_release(struct socket *sock)
510 struct sock *sk = sock->sk;
511 struct netlink_sock *nlk;
521 * OK. Socket is unlinked, any packets that arrive now
526 wake_up_interruptible_all(&nlk->wait);
528 skb_queue_purge(&sk->sk_write_queue);
531 struct netlink_notify n = {
533 .protocol = sk->sk_protocol,
534 .portid = nlk->portid,
536 atomic_notifier_call_chain(&netlink_chain,
537 NETLINK_URELEASE, &n);
540 module_put(nlk->module);
542 netlink_table_grab();
543 if (netlink_is_kernel(sk)) {
544 BUG_ON(nl_table[sk->sk_protocol].registered == 0);
545 if (--nl_table[sk->sk_protocol].registered == 0) {
546 struct listeners *old;
548 old = nl_deref_protected(nl_table[sk->sk_protocol].listeners);
549 RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL);
551 nl_table[sk->sk_protocol].module = NULL;
552 nl_table[sk->sk_protocol].bind = NULL;
553 nl_table[sk->sk_protocol].flags = 0;
554 nl_table[sk->sk_protocol].registered = 0;
556 } else if (nlk->subscriptions) {
557 netlink_update_listeners(sk);
559 netlink_table_ungrab();
565 sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1);
571 static int netlink_autobind(struct socket *sock)
573 struct sock *sk = sock->sk;
574 struct net *net = sock_net(sk);
575 struct nl_portid_hash *hash = &nl_table[sk->sk_protocol].hash;
576 struct hlist_head *head;
578 struct hlist_node *node;
579 s32 portid = task_tgid_vnr(current);
581 static s32 rover = -4097;
585 netlink_table_grab();
586 head = nl_portid_hashfn(hash, portid);
587 sk_for_each(osk, node, head) {
588 if (!net_eq(sock_net(osk), net))
590 if (nlk_sk(osk)->portid == portid) {
591 /* Bind collision, search negative portid values. */
595 netlink_table_ungrab();
599 netlink_table_ungrab();
601 err = netlink_insert(sk, net, portid);
602 if (err == -EADDRINUSE)
605 /* If 2 threads race to autobind, that is fine. */
612 static inline int netlink_capable(const struct socket *sock, unsigned int flag)
614 return (nl_table[sock->sk->sk_protocol].flags & flag) ||
615 ns_capable(sock_net(sock->sk)->user_ns, CAP_NET_ADMIN);
619 netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions)
621 struct netlink_sock *nlk = nlk_sk(sk);
623 if (nlk->subscriptions && !subscriptions)
624 __sk_del_bind_node(sk);
625 else if (!nlk->subscriptions && subscriptions)
626 sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
627 nlk->subscriptions = subscriptions;
630 static int netlink_realloc_groups(struct sock *sk)
632 struct netlink_sock *nlk = nlk_sk(sk);
634 unsigned long *new_groups;
637 netlink_table_grab();
639 groups = nl_table[sk->sk_protocol].groups;
640 if (!nl_table[sk->sk_protocol].registered) {
645 if (nlk->ngroups >= groups)
648 new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC);
649 if (new_groups == NULL) {
653 memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0,
654 NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups));
656 nlk->groups = new_groups;
657 nlk->ngroups = groups;
659 netlink_table_ungrab();
663 static int netlink_bind(struct socket *sock, struct sockaddr *addr,
666 struct sock *sk = sock->sk;
667 struct net *net = sock_net(sk);
668 struct netlink_sock *nlk = nlk_sk(sk);
669 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
672 if (nladdr->nl_family != AF_NETLINK)
675 /* Only superuser is allowed to listen multicasts */
676 if (nladdr->nl_groups) {
677 if (!netlink_capable(sock, NL_CFG_F_NONROOT_RECV))
679 err = netlink_realloc_groups(sk);
685 if (nladdr->nl_pid != nlk->portid)
688 err = nladdr->nl_pid ?
689 netlink_insert(sk, net, nladdr->nl_pid) :
690 netlink_autobind(sock);
695 if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
698 netlink_table_grab();
699 netlink_update_subscriptions(sk, nlk->subscriptions +
700 hweight32(nladdr->nl_groups) -
701 hweight32(nlk->groups[0]));
702 nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups;
703 netlink_update_listeners(sk);
704 netlink_table_ungrab();
706 if (nlk->netlink_bind && nlk->groups[0]) {
709 for (i=0; i<nlk->ngroups; i++) {
710 if (test_bit(i, nlk->groups))
711 nlk->netlink_bind(i);
718 static int netlink_connect(struct socket *sock, struct sockaddr *addr,
722 struct sock *sk = sock->sk;
723 struct netlink_sock *nlk = nlk_sk(sk);
724 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
726 if (alen < sizeof(addr->sa_family))
729 if (addr->sa_family == AF_UNSPEC) {
730 sk->sk_state = NETLINK_UNCONNECTED;
735 if (addr->sa_family != AF_NETLINK)
738 /* Only superuser is allowed to send multicasts */
739 if (nladdr->nl_groups && !netlink_capable(sock, NL_CFG_F_NONROOT_SEND))
743 err = netlink_autobind(sock);
746 sk->sk_state = NETLINK_CONNECTED;
747 nlk->dst_portid = nladdr->nl_pid;
748 nlk->dst_group = ffs(nladdr->nl_groups);
754 static int netlink_getname(struct socket *sock, struct sockaddr *addr,
755 int *addr_len, int peer)
757 struct sock *sk = sock->sk;
758 struct netlink_sock *nlk = nlk_sk(sk);
759 DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr);
761 nladdr->nl_family = AF_NETLINK;
763 *addr_len = sizeof(*nladdr);
766 nladdr->nl_pid = nlk->dst_portid;
767 nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
769 nladdr->nl_pid = nlk->portid;
770 nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
775 static void netlink_overrun(struct sock *sk)
777 struct netlink_sock *nlk = nlk_sk(sk);
779 if (!(nlk->flags & NETLINK_RECV_NO_ENOBUFS)) {
780 if (!test_and_set_bit(0, &nlk_sk(sk)->state)) {
781 sk->sk_err = ENOBUFS;
782 sk->sk_error_report(sk);
785 atomic_inc(&sk->sk_drops);
788 static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid)
791 struct netlink_sock *nlk;
793 sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, portid);
795 return ERR_PTR(-ECONNREFUSED);
797 /* Don't bother queuing skb if kernel socket has no input function */
799 if (sock->sk_state == NETLINK_CONNECTED &&
800 nlk->dst_portid != nlk_sk(ssk)->portid) {
802 return ERR_PTR(-ECONNREFUSED);
807 struct sock *netlink_getsockbyfilp(struct file *filp)
809 struct inode *inode = filp->f_path.dentry->d_inode;
812 if (!S_ISSOCK(inode->i_mode))
813 return ERR_PTR(-ENOTSOCK);
815 sock = SOCKET_I(inode)->sk;
816 if (sock->sk_family != AF_NETLINK)
817 return ERR_PTR(-EINVAL);
824 * Attach a skb to a netlink socket.
825 * The caller must hold a reference to the destination socket. On error, the
826 * reference is dropped. The skb is not send to the destination, just all
827 * all error checks are performed and memory in the queue is reserved.
829 * < 0: error. skb freed, reference to sock dropped.
831 * 1: repeat lookup - reference dropped while waiting for socket memory.
833 int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
834 long *timeo, struct sock *ssk)
836 struct netlink_sock *nlk;
840 if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
841 test_bit(0, &nlk->state)) {
842 DECLARE_WAITQUEUE(wait, current);
844 if (!ssk || netlink_is_kernel(ssk))
851 __set_current_state(TASK_INTERRUPTIBLE);
852 add_wait_queue(&nlk->wait, &wait);
854 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
855 test_bit(0, &nlk->state)) &&
856 !sock_flag(sk, SOCK_DEAD))
857 *timeo = schedule_timeout(*timeo);
859 __set_current_state(TASK_RUNNING);
860 remove_wait_queue(&nlk->wait, &wait);
863 if (signal_pending(current)) {
865 return sock_intr_errno(*timeo);
869 skb_set_owner_r(skb, sk);
873 static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb)
877 skb_queue_tail(&sk->sk_receive_queue, skb);
878 sk->sk_data_ready(sk, len);
882 int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
884 int len = __netlink_sendskb(sk, skb);
890 void netlink_detachskb(struct sock *sk, struct sk_buff *skb)
896 static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation)
902 delta = skb->end - skb->tail;
903 if (delta * 2 < skb->truesize)
906 if (skb_shared(skb)) {
907 struct sk_buff *nskb = skb_clone(skb, allocation);
914 if (!pskb_expand_head(skb, 0, -delta, allocation))
915 skb->truesize -= delta;
920 static void netlink_rcv_wake(struct sock *sk)
922 struct netlink_sock *nlk = nlk_sk(sk);
924 if (skb_queue_empty(&sk->sk_receive_queue))
925 clear_bit(0, &nlk->state);
926 if (!test_bit(0, &nlk->state))
927 wake_up_interruptible(&nlk->wait);
930 static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb,
934 struct netlink_sock *nlk = nlk_sk(sk);
937 if (nlk->netlink_rcv != NULL) {
939 skb_set_owner_r(skb, sk);
940 NETLINK_CB(skb).ssk = ssk;
941 nlk->netlink_rcv(skb);
950 int netlink_unicast(struct sock *ssk, struct sk_buff *skb,
951 u32 portid, int nonblock)
957 skb = netlink_trim(skb, gfp_any());
959 timeo = sock_sndtimeo(ssk, nonblock);
961 sk = netlink_getsockbyportid(ssk, portid);
966 if (netlink_is_kernel(sk))
967 return netlink_unicast_kernel(sk, skb, ssk);
969 if (sk_filter(sk, skb)) {
976 err = netlink_attachskb(sk, skb, &timeo, ssk);
982 return netlink_sendskb(sk, skb);
984 EXPORT_SYMBOL(netlink_unicast);
986 int netlink_has_listeners(struct sock *sk, unsigned int group)
989 struct listeners *listeners;
991 BUG_ON(!netlink_is_kernel(sk));
994 listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners);
996 if (listeners && group - 1 < nl_table[sk->sk_protocol].groups)
997 res = test_bit(group - 1, listeners->masks);
1003 EXPORT_SYMBOL_GPL(netlink_has_listeners);
1005 static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb)
1007 struct netlink_sock *nlk = nlk_sk(sk);
1009 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
1010 !test_bit(0, &nlk->state)) {
1011 skb_set_owner_r(skb, sk);
1012 __netlink_sendskb(sk, skb);
1013 return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1);
1018 struct netlink_broadcast_data {
1019 struct sock *exclude_sk;
1024 int delivery_failure;
1028 struct sk_buff *skb, *skb2;
1029 int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data);
1033 static int do_one_broadcast(struct sock *sk,
1034 struct netlink_broadcast_data *p)
1036 struct netlink_sock *nlk = nlk_sk(sk);
1039 if (p->exclude_sk == sk)
1042 if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups ||
1043 !test_bit(p->group - 1, nlk->groups))
1046 if (!net_eq(sock_net(sk), p->net))
1050 netlink_overrun(sk);
1055 if (p->skb2 == NULL) {
1056 if (skb_shared(p->skb)) {
1057 p->skb2 = skb_clone(p->skb, p->allocation);
1059 p->skb2 = skb_get(p->skb);
1061 * skb ownership may have been set when
1062 * delivered to a previous socket.
1064 skb_orphan(p->skb2);
1067 if (p->skb2 == NULL) {
1068 netlink_overrun(sk);
1069 /* Clone failed. Notify ALL listeners. */
1071 if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR)
1072 p->delivery_failure = 1;
1073 } else if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) {
1076 } else if (sk_filter(sk, p->skb2)) {
1079 } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) {
1080 netlink_overrun(sk);
1081 if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR)
1082 p->delivery_failure = 1;
1084 p->congested |= val;
1094 int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 portid,
1095 u32 group, gfp_t allocation,
1096 int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
1099 struct net *net = sock_net(ssk);
1100 struct netlink_broadcast_data info;
1101 struct hlist_node *node;
1104 skb = netlink_trim(skb, allocation);
1106 info.exclude_sk = ssk;
1108 info.portid = portid;
1111 info.delivery_failure = 0;
1114 info.allocation = allocation;
1117 info.tx_filter = filter;
1118 info.tx_data = filter_data;
1120 /* While we sleep in clone, do not allow to change socket list */
1122 netlink_lock_table();
1124 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
1125 do_one_broadcast(sk, &info);
1129 netlink_unlock_table();
1131 if (info.delivery_failure) {
1132 kfree_skb(info.skb2);
1135 consume_skb(info.skb2);
1137 if (info.delivered) {
1138 if (info.congested && (allocation & __GFP_WAIT))
1144 EXPORT_SYMBOL(netlink_broadcast_filtered);
1146 int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 portid,
1147 u32 group, gfp_t allocation)
1149 return netlink_broadcast_filtered(ssk, skb, portid, group, allocation,
1152 EXPORT_SYMBOL(netlink_broadcast);
1154 struct netlink_set_err_data {
1155 struct sock *exclude_sk;
1161 static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p)
1163 struct netlink_sock *nlk = nlk_sk(sk);
1166 if (sk == p->exclude_sk)
1169 if (!net_eq(sock_net(sk), sock_net(p->exclude_sk)))
1172 if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups ||
1173 !test_bit(p->group - 1, nlk->groups))
1176 if (p->code == ENOBUFS && nlk->flags & NETLINK_RECV_NO_ENOBUFS) {
1181 sk->sk_err = p->code;
1182 sk->sk_error_report(sk);
1188 * netlink_set_err - report error to broadcast listeners
1189 * @ssk: the kernel netlink socket, as returned by netlink_kernel_create()
1190 * @portid: the PORTID of a process that we want to skip (if any)
1191 * @groups: the broadcast group that will notice the error
1192 * @code: error code, must be negative (as usual in kernelspace)
1194 * This function returns the number of broadcast listeners that have set the
1195 * NETLINK_RECV_NO_ENOBUFS socket option.
1197 int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code)
1199 struct netlink_set_err_data info;
1200 struct hlist_node *node;
1204 info.exclude_sk = ssk;
1205 info.portid = portid;
1207 /* sk->sk_err wants a positive error value */
1210 read_lock(&nl_table_lock);
1212 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
1213 ret += do_one_set_err(sk, &info);
1215 read_unlock(&nl_table_lock);
1218 EXPORT_SYMBOL(netlink_set_err);
1220 /* must be called with netlink table grabbed */
1221 static void netlink_update_socket_mc(struct netlink_sock *nlk,
1225 int old, new = !!is_new, subscriptions;
1227 old = test_bit(group - 1, nlk->groups);
1228 subscriptions = nlk->subscriptions - old + new;
1230 __set_bit(group - 1, nlk->groups);
1232 __clear_bit(group - 1, nlk->groups);
1233 netlink_update_subscriptions(&nlk->sk, subscriptions);
1234 netlink_update_listeners(&nlk->sk);
1237 static int netlink_setsockopt(struct socket *sock, int level, int optname,
1238 char __user *optval, unsigned int optlen)
1240 struct sock *sk = sock->sk;
1241 struct netlink_sock *nlk = nlk_sk(sk);
1242 unsigned int val = 0;
1245 if (level != SOL_NETLINK)
1246 return -ENOPROTOOPT;
1248 if (optlen >= sizeof(int) &&
1249 get_user(val, (unsigned int __user *)optval))
1253 case NETLINK_PKTINFO:
1255 nlk->flags |= NETLINK_RECV_PKTINFO;
1257 nlk->flags &= ~NETLINK_RECV_PKTINFO;
1260 case NETLINK_ADD_MEMBERSHIP:
1261 case NETLINK_DROP_MEMBERSHIP: {
1262 if (!netlink_capable(sock, NL_CFG_F_NONROOT_RECV))
1264 err = netlink_realloc_groups(sk);
1267 if (!val || val - 1 >= nlk->ngroups)
1269 netlink_table_grab();
1270 netlink_update_socket_mc(nlk, val,
1271 optname == NETLINK_ADD_MEMBERSHIP);
1272 netlink_table_ungrab();
1274 if (nlk->netlink_bind)
1275 nlk->netlink_bind(val);
1280 case NETLINK_BROADCAST_ERROR:
1282 nlk->flags |= NETLINK_BROADCAST_SEND_ERROR;
1284 nlk->flags &= ~NETLINK_BROADCAST_SEND_ERROR;
1287 case NETLINK_NO_ENOBUFS:
1289 nlk->flags |= NETLINK_RECV_NO_ENOBUFS;
1290 clear_bit(0, &nlk->state);
1291 wake_up_interruptible(&nlk->wait);
1293 nlk->flags &= ~NETLINK_RECV_NO_ENOBUFS;
1303 static int netlink_getsockopt(struct socket *sock, int level, int optname,
1304 char __user *optval, int __user *optlen)
1306 struct sock *sk = sock->sk;
1307 struct netlink_sock *nlk = nlk_sk(sk);
1310 if (level != SOL_NETLINK)
1311 return -ENOPROTOOPT;
1313 if (get_user(len, optlen))
1319 case NETLINK_PKTINFO:
1320 if (len < sizeof(int))
1323 val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0;
1324 if (put_user(len, optlen) ||
1325 put_user(val, optval))
1329 case NETLINK_BROADCAST_ERROR:
1330 if (len < sizeof(int))
1333 val = nlk->flags & NETLINK_BROADCAST_SEND_ERROR ? 1 : 0;
1334 if (put_user(len, optlen) ||
1335 put_user(val, optval))
1339 case NETLINK_NO_ENOBUFS:
1340 if (len < sizeof(int))
1343 val = nlk->flags & NETLINK_RECV_NO_ENOBUFS ? 1 : 0;
1344 if (put_user(len, optlen) ||
1345 put_user(val, optval))
1355 static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
1357 struct nl_pktinfo info;
1359 info.group = NETLINK_CB(skb).dst_group;
1360 put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info);
1363 static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
1364 struct msghdr *msg, size_t len)
1366 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1367 struct sock *sk = sock->sk;
1368 struct netlink_sock *nlk = nlk_sk(sk);
1369 struct sockaddr_nl *addr = msg->msg_name;
1372 struct sk_buff *skb;
1374 struct scm_cookie scm;
1376 if (msg->msg_flags&MSG_OOB)
1379 if (NULL == siocb->scm)
1382 err = scm_send(sock, msg, siocb->scm, true);
1386 if (msg->msg_namelen) {
1388 if (addr->nl_family != AF_NETLINK)
1390 dst_portid = addr->nl_pid;
1391 dst_group = ffs(addr->nl_groups);
1393 if ((dst_group || dst_portid) &&
1394 !netlink_capable(sock, NL_CFG_F_NONROOT_SEND))
1397 dst_portid = nlk->dst_portid;
1398 dst_group = nlk->dst_group;
1402 err = netlink_autobind(sock);
1408 if (len > sk->sk_sndbuf - 32)
1411 skb = alloc_skb(len, GFP_KERNEL);
1415 NETLINK_CB(skb).portid = nlk->portid;
1416 NETLINK_CB(skb).dst_group = dst_group;
1417 NETLINK_CB(skb).creds = siocb->scm->creds;
1420 if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
1425 err = security_netlink_send(sk, skb);
1432 atomic_inc(&skb->users);
1433 netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL);
1435 err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags&MSG_DONTWAIT);
1438 scm_destroy(siocb->scm);
1442 static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
1443 struct msghdr *msg, size_t len,
1446 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1447 struct scm_cookie scm;
1448 struct sock *sk = sock->sk;
1449 struct netlink_sock *nlk = nlk_sk(sk);
1450 int noblock = flags&MSG_DONTWAIT;
1452 struct sk_buff *skb, *data_skb;
1460 skb = skb_recv_datagram(sk, flags, noblock, &err);
1466 #ifdef CONFIG_COMPAT_NETLINK_MESSAGES
1467 if (unlikely(skb_shinfo(skb)->frag_list)) {
1469 * If this skb has a frag_list, then here that means that we
1470 * will have to use the frag_list skb's data for compat tasks
1471 * and the regular skb's data for normal (non-compat) tasks.
1473 * If we need to send the compat skb, assign it to the
1474 * 'data_skb' variable so that it will be used below for data
1475 * copying. We keep 'skb' for everything else, including
1476 * freeing both later.
1478 if (flags & MSG_CMSG_COMPAT)
1479 data_skb = skb_shinfo(skb)->frag_list;
1483 msg->msg_namelen = 0;
1485 copied = data_skb->len;
1487 msg->msg_flags |= MSG_TRUNC;
1491 skb_reset_transport_header(data_skb);
1492 err = skb_copy_datagram_iovec(data_skb, 0, msg->msg_iov, copied);
1494 if (msg->msg_name) {
1495 struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name;
1496 addr->nl_family = AF_NETLINK;
1498 addr->nl_pid = NETLINK_CB(skb).portid;
1499 addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group);
1500 msg->msg_namelen = sizeof(*addr);
1503 if (nlk->flags & NETLINK_RECV_PKTINFO)
1504 netlink_cmsg_recv_pktinfo(msg, skb);
1506 if (NULL == siocb->scm) {
1507 memset(&scm, 0, sizeof(scm));
1510 siocb->scm->creds = *NETLINK_CREDS(skb);
1511 if (flags & MSG_TRUNC)
1512 copied = data_skb->len;
1514 skb_free_datagram(sk, skb);
1516 if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) {
1517 ret = netlink_dump(sk);
1520 sk->sk_error_report(sk);
1524 scm_recv(sock, msg, siocb->scm, flags);
1526 netlink_rcv_wake(sk);
1527 return err ? : copied;
1530 static void netlink_data_ready(struct sock *sk, int len)
1536 * We export these functions to other modules. They provide a
1537 * complete set of kernel non-blocking support for message
1542 __netlink_kernel_create(struct net *net, int unit, struct module *module,
1543 struct netlink_kernel_cfg *cfg)
1545 struct socket *sock;
1547 struct netlink_sock *nlk;
1548 struct listeners *listeners = NULL;
1549 struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL;
1550 unsigned int groups;
1554 if (unit < 0 || unit >= MAX_LINKS)
1557 if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
1561 * We have to just have a reference on the net from sk, but don't
1562 * get_net it. Besides, we cannot get and then put the net here.
1563 * So we create one inside init_net and the move it to net.
1566 if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0)
1567 goto out_sock_release_nosk;
1570 sk_change_net(sk, net);
1572 if (!cfg || cfg->groups < 32)
1575 groups = cfg->groups;
1577 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
1579 goto out_sock_release;
1581 sk->sk_data_ready = netlink_data_ready;
1582 if (cfg && cfg->input)
1583 nlk_sk(sk)->netlink_rcv = cfg->input;
1585 if (netlink_insert(sk, net, 0))
1586 goto out_sock_release;
1589 nlk->flags |= NETLINK_KERNEL_SOCKET;
1591 netlink_table_grab();
1592 if (!nl_table[unit].registered) {
1593 nl_table[unit].groups = groups;
1594 rcu_assign_pointer(nl_table[unit].listeners, listeners);
1595 nl_table[unit].cb_mutex = cb_mutex;
1596 nl_table[unit].module = module;
1598 nl_table[unit].bind = cfg->bind;
1599 nl_table[unit].flags = cfg->flags;
1601 nl_table[unit].registered = 1;
1604 nl_table[unit].registered++;
1606 netlink_table_ungrab();
1611 netlink_kernel_release(sk);
1614 out_sock_release_nosk:
1618 EXPORT_SYMBOL(__netlink_kernel_create);
1621 netlink_kernel_release(struct sock *sk)
1623 sk_release_kernel(sk);
1625 EXPORT_SYMBOL(netlink_kernel_release);
1627 int __netlink_change_ngroups(struct sock *sk, unsigned int groups)
1629 struct listeners *new, *old;
1630 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
1635 if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) {
1636 new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC);
1639 old = nl_deref_protected(tbl->listeners);
1640 memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups));
1641 rcu_assign_pointer(tbl->listeners, new);
1643 kfree_rcu(old, rcu);
1645 tbl->groups = groups;
1651 * netlink_change_ngroups - change number of multicast groups
1653 * This changes the number of multicast groups that are available
1654 * on a certain netlink family. Note that it is not possible to
1655 * change the number of groups to below 32. Also note that it does
1656 * not implicitly call netlink_clear_multicast_users() when the
1657 * number of groups is reduced.
1659 * @sk: The kernel netlink socket, as returned by netlink_kernel_create().
1660 * @groups: The new number of groups.
1662 int netlink_change_ngroups(struct sock *sk, unsigned int groups)
1666 netlink_table_grab();
1667 err = __netlink_change_ngroups(sk, groups);
1668 netlink_table_ungrab();
1673 void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
1676 struct hlist_node *node;
1677 struct netlink_table *tbl = &nl_table[ksk->sk_protocol];
1679 sk_for_each_bound(sk, node, &tbl->mc_list)
1680 netlink_update_socket_mc(nlk_sk(sk), group, 0);
1684 * netlink_clear_multicast_users - kick off multicast listeners
1686 * This function removes all listeners from the given group.
1687 * @ksk: The kernel netlink socket, as returned by
1688 * netlink_kernel_create().
1689 * @group: The multicast group to clear.
1691 void netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
1693 netlink_table_grab();
1694 __netlink_clear_multicast_users(ksk, group);
1695 netlink_table_ungrab();
1699 __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags)
1701 struct nlmsghdr *nlh;
1702 int size = NLMSG_LENGTH(len);
1704 nlh = (struct nlmsghdr*)skb_put(skb, NLMSG_ALIGN(size));
1705 nlh->nlmsg_type = type;
1706 nlh->nlmsg_len = size;
1707 nlh->nlmsg_flags = flags;
1708 nlh->nlmsg_pid = portid;
1709 nlh->nlmsg_seq = seq;
1710 if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0)
1711 memset(NLMSG_DATA(nlh) + len, 0, NLMSG_ALIGN(size) - size);
1714 EXPORT_SYMBOL(__nlmsg_put);
1717 * It looks a bit ugly.
1718 * It would be better to create kernel thread.
1721 static int netlink_dump(struct sock *sk)
1723 struct netlink_sock *nlk = nlk_sk(sk);
1724 struct netlink_callback *cb;
1725 struct sk_buff *skb = NULL;
1726 struct nlmsghdr *nlh;
1727 int len, err = -ENOBUFS;
1730 mutex_lock(nlk->cb_mutex);
1738 alloc_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE);
1740 skb = sock_rmalloc(sk, alloc_size, 0, GFP_KERNEL);
1744 len = cb->dump(skb, cb);
1747 mutex_unlock(nlk->cb_mutex);
1749 if (sk_filter(sk, skb))
1752 __netlink_sendskb(sk, skb);
1756 nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI);
1760 nl_dump_check_consistent(cb, nlh);
1762 memcpy(nlmsg_data(nlh), &len, sizeof(len));
1764 if (sk_filter(sk, skb))
1767 __netlink_sendskb(sk, skb);
1772 mutex_unlock(nlk->cb_mutex);
1774 module_put(cb->module);
1775 netlink_consume_callback(cb);
1779 mutex_unlock(nlk->cb_mutex);
1784 int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
1785 const struct nlmsghdr *nlh,
1786 struct netlink_dump_control *control)
1788 struct netlink_callback *cb;
1790 struct netlink_sock *nlk;
1793 cb = kzalloc(sizeof(*cb), GFP_KERNEL);
1797 cb->dump = control->dump;
1798 cb->done = control->done;
1800 cb->data = control->data;
1801 cb->module = control->module;
1802 cb->min_dump_alloc = control->min_dump_alloc;
1803 atomic_inc(&skb->users);
1806 sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).portid);
1808 netlink_destroy_callback(cb);
1809 return -ECONNREFUSED;
1813 mutex_lock(nlk->cb_mutex);
1814 /* A dump is in progress... */
1816 mutex_unlock(nlk->cb_mutex);
1817 netlink_destroy_callback(cb);
1821 /* add reference of module which cb->dump belongs to */
1822 if (!try_module_get(cb->module)) {
1823 mutex_unlock(nlk->cb_mutex);
1824 netlink_destroy_callback(cb);
1825 ret = -EPROTONOSUPPORT;
1830 mutex_unlock(nlk->cb_mutex);
1832 ret = netlink_dump(sk);
1839 /* We successfully started a dump, by returning -EINTR we
1840 * signal not to send ACK even if it was requested.
1844 EXPORT_SYMBOL(__netlink_dump_start);
1846 void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
1848 struct sk_buff *skb;
1849 struct nlmsghdr *rep;
1850 struct nlmsgerr *errmsg;
1851 size_t payload = sizeof(*errmsg);
1853 /* error messages get the original request appened */
1855 payload += nlmsg_len(nlh);
1857 skb = nlmsg_new(payload, GFP_KERNEL);
1861 sk = netlink_lookup(sock_net(in_skb->sk),
1862 in_skb->sk->sk_protocol,
1863 NETLINK_CB(in_skb).portid);
1865 sk->sk_err = ENOBUFS;
1866 sk->sk_error_report(sk);
1872 rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
1873 NLMSG_ERROR, payload, 0);
1874 errmsg = nlmsg_data(rep);
1875 errmsg->error = err;
1876 memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh));
1877 netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT);
1879 EXPORT_SYMBOL(netlink_ack);
1881 int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
1884 struct nlmsghdr *nlh;
1887 while (skb->len >= nlmsg_total_size(0)) {
1890 nlh = nlmsg_hdr(skb);
1893 if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
1896 /* Only requests are handled by the kernel */
1897 if (!(nlh->nlmsg_flags & NLM_F_REQUEST))
1900 /* Skip control messages */
1901 if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
1909 if (nlh->nlmsg_flags & NLM_F_ACK || err)
1910 netlink_ack(skb, nlh, err);
1913 msglen = NLMSG_ALIGN(nlh->nlmsg_len);
1914 if (msglen > skb->len)
1916 skb_pull(skb, msglen);
1921 EXPORT_SYMBOL(netlink_rcv_skb);
1924 * nlmsg_notify - send a notification netlink message
1925 * @sk: netlink socket to use
1926 * @skb: notification message
1927 * @portid: destination netlink portid for reports or 0
1928 * @group: destination multicast group or 0
1929 * @report: 1 to report back, 0 to disable
1930 * @flags: allocation flags
1932 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
1933 unsigned int group, int report, gfp_t flags)
1938 int exclude_portid = 0;
1941 atomic_inc(&skb->users);
1942 exclude_portid = portid;
1945 /* errors reported via destination sk->sk_err, but propagate
1946 * delivery errors if NETLINK_BROADCAST_ERROR flag is set */
1947 err = nlmsg_multicast(sk, skb, exclude_portid, group, flags);
1953 err2 = nlmsg_unicast(sk, skb, portid);
1954 if (!err || err == -ESRCH)
1960 EXPORT_SYMBOL(nlmsg_notify);
1962 #ifdef CONFIG_PROC_FS
1963 struct nl_seq_iter {
1964 struct seq_net_private p;
1969 static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos)
1971 struct nl_seq_iter *iter = seq->private;
1974 struct hlist_node *node;
1977 for (i = 0; i < MAX_LINKS; i++) {
1978 struct nl_portid_hash *hash = &nl_table[i].hash;
1980 for (j = 0; j <= hash->mask; j++) {
1981 sk_for_each(s, node, &hash->table[j]) {
1982 if (sock_net(s) != seq_file_net(seq))
1996 static void *netlink_seq_start(struct seq_file *seq, loff_t *pos)
1997 __acquires(nl_table_lock)
1999 read_lock(&nl_table_lock);
2000 return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2003 static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2006 struct nl_seq_iter *iter;
2011 if (v == SEQ_START_TOKEN)
2012 return netlink_seq_socket_idx(seq, 0);
2014 iter = seq->private;
2018 } while (s && sock_net(s) != seq_file_net(seq));
2023 j = iter->hash_idx + 1;
2026 struct nl_portid_hash *hash = &nl_table[i].hash;
2028 for (; j <= hash->mask; j++) {
2029 s = sk_head(&hash->table[j]);
2030 while (s && sock_net(s) != seq_file_net(seq))
2040 } while (++i < MAX_LINKS);
2045 static void netlink_seq_stop(struct seq_file *seq, void *v)
2046 __releases(nl_table_lock)
2048 read_unlock(&nl_table_lock);
2052 static int netlink_seq_show(struct seq_file *seq, void *v)
2054 if (v == SEQ_START_TOKEN) {
2056 "sk Eth Pid Groups "
2057 "Rmem Wmem Dump Locks Drops Inode\n");
2060 struct netlink_sock *nlk = nlk_sk(s);
2062 seq_printf(seq, "%pK %-3d %-6d %08x %-8d %-8d %pK %-8d %-8d %-8lu\n",
2066 nlk->groups ? (u32)nlk->groups[0] : 0,
2067 sk_rmem_alloc_get(s),
2068 sk_wmem_alloc_get(s),
2070 atomic_read(&s->sk_refcnt),
2071 atomic_read(&s->sk_drops),
2079 static const struct seq_operations netlink_seq_ops = {
2080 .start = netlink_seq_start,
2081 .next = netlink_seq_next,
2082 .stop = netlink_seq_stop,
2083 .show = netlink_seq_show,
2087 static int netlink_seq_open(struct inode *inode, struct file *file)
2089 return seq_open_net(inode, file, &netlink_seq_ops,
2090 sizeof(struct nl_seq_iter));
2093 static const struct file_operations netlink_seq_fops = {
2094 .owner = THIS_MODULE,
2095 .open = netlink_seq_open,
2097 .llseek = seq_lseek,
2098 .release = seq_release_net,
2103 int netlink_register_notifier(struct notifier_block *nb)
2105 return atomic_notifier_chain_register(&netlink_chain, nb);
2107 EXPORT_SYMBOL(netlink_register_notifier);
2109 int netlink_unregister_notifier(struct notifier_block *nb)
2111 return atomic_notifier_chain_unregister(&netlink_chain, nb);
2113 EXPORT_SYMBOL(netlink_unregister_notifier);
2115 static const struct proto_ops netlink_ops = {
2116 .family = PF_NETLINK,
2117 .owner = THIS_MODULE,
2118 .release = netlink_release,
2119 .bind = netlink_bind,
2120 .connect = netlink_connect,
2121 .socketpair = sock_no_socketpair,
2122 .accept = sock_no_accept,
2123 .getname = netlink_getname,
2124 .poll = datagram_poll,
2125 .ioctl = sock_no_ioctl,
2126 .listen = sock_no_listen,
2127 .shutdown = sock_no_shutdown,
2128 .setsockopt = netlink_setsockopt,
2129 .getsockopt = netlink_getsockopt,
2130 .sendmsg = netlink_sendmsg,
2131 .recvmsg = netlink_recvmsg,
2132 .mmap = sock_no_mmap,
2133 .sendpage = sock_no_sendpage,
2136 static const struct net_proto_family netlink_family_ops = {
2137 .family = PF_NETLINK,
2138 .create = netlink_create,
2139 .owner = THIS_MODULE, /* for consistency 8) */
2142 static int __net_init netlink_net_init(struct net *net)
2144 #ifdef CONFIG_PROC_FS
2145 if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops))
2151 static void __net_exit netlink_net_exit(struct net *net)
2153 #ifdef CONFIG_PROC_FS
2154 proc_net_remove(net, "netlink");
2158 static void __init netlink_add_usersock_entry(void)
2160 struct listeners *listeners;
2163 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
2165 panic("netlink_add_usersock_entry: Cannot allocate listeners\n");
2167 netlink_table_grab();
2169 nl_table[NETLINK_USERSOCK].groups = groups;
2170 rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners);
2171 nl_table[NETLINK_USERSOCK].module = THIS_MODULE;
2172 nl_table[NETLINK_USERSOCK].registered = 1;
2173 nl_table[NETLINK_USERSOCK].flags = NL_CFG_F_NONROOT_SEND;
2175 netlink_table_ungrab();
2178 static struct pernet_operations __net_initdata netlink_net_ops = {
2179 .init = netlink_net_init,
2180 .exit = netlink_net_exit,
2183 static int __init netlink_proto_init(void)
2185 struct sk_buff *dummy_skb;
2187 unsigned long limit;
2189 int err = proto_register(&netlink_proto, 0);
2194 BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb));
2196 nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);
2200 if (totalram_pages >= (128 * 1024))
2201 limit = totalram_pages >> (21 - PAGE_SHIFT);
2203 limit = totalram_pages >> (23 - PAGE_SHIFT);
2205 order = get_bitmask_order(limit) - 1 + PAGE_SHIFT;
2206 limit = (1UL << order) / sizeof(struct hlist_head);
2207 order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1;
2209 for (i = 0; i < MAX_LINKS; i++) {
2210 struct nl_portid_hash *hash = &nl_table[i].hash;
2212 hash->table = nl_portid_hash_zalloc(1 * sizeof(*hash->table));
2215 nl_portid_hash_free(nl_table[i].hash.table,
2216 1 * sizeof(*hash->table));
2220 hash->max_shift = order;
2223 hash->rehash_time = jiffies;
2226 netlink_add_usersock_entry();
2228 sock_register(&netlink_family_ops);
2229 register_pernet_subsys(&netlink_net_ops);
2230 /* The netlink device handler may be needed early. */
2235 panic("netlink_init: Cannot allocate nl_table\n");
2238 core_initcall(netlink_proto_init);