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;
86 struct listeners_rcu_head {
87 struct rcu_head rcu_head;
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 unsigned long *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 static ATOMIC_NOTIFIER_HEAD(netlink_chain);
142 static u32 netlink_group_mask(u32 group)
144 return group ? 1 << (group - 1) : 0;
147 static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid)
149 return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask];
152 static void netlink_sock_destruct(struct sock *sk)
154 struct netlink_sock *nlk = nlk_sk(sk);
158 nlk->cb->done(nlk->cb);
159 netlink_destroy_callback(nlk->cb);
162 skb_queue_purge(&sk->sk_receive_queue);
164 if (!sock_flag(sk, SOCK_DEAD)) {
165 printk(KERN_ERR "Freeing alive netlink socket %p\n", sk);
169 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
170 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
171 WARN_ON(nlk_sk(sk)->groups);
174 /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on
175 * SMP. Look, when several writers sleep and reader wakes them up, all but one
176 * immediately hit write lock and grab all the cpus. Exclusive sleep solves
177 * this, _but_ remember, it adds useless work on UP machines.
180 void netlink_table_grab(void)
181 __acquires(nl_table_lock)
185 write_lock_irq(&nl_table_lock);
187 if (atomic_read(&nl_table_users)) {
188 DECLARE_WAITQUEUE(wait, current);
190 add_wait_queue_exclusive(&nl_table_wait, &wait);
192 set_current_state(TASK_UNINTERRUPTIBLE);
193 if (atomic_read(&nl_table_users) == 0)
195 write_unlock_irq(&nl_table_lock);
197 write_lock_irq(&nl_table_lock);
200 __set_current_state(TASK_RUNNING);
201 remove_wait_queue(&nl_table_wait, &wait);
205 void netlink_table_ungrab(void)
206 __releases(nl_table_lock)
208 write_unlock_irq(&nl_table_lock);
209 wake_up(&nl_table_wait);
213 netlink_lock_table(void)
215 /* read_lock() synchronizes us to netlink_table_grab */
217 read_lock(&nl_table_lock);
218 atomic_inc(&nl_table_users);
219 read_unlock(&nl_table_lock);
223 netlink_unlock_table(void)
225 if (atomic_dec_and_test(&nl_table_users))
226 wake_up(&nl_table_wait);
229 static inline struct sock *netlink_lookup(struct net *net, int protocol,
232 struct nl_pid_hash *hash = &nl_table[protocol].hash;
233 struct hlist_head *head;
235 struct hlist_node *node;
237 read_lock(&nl_table_lock);
238 head = nl_pid_hashfn(hash, pid);
239 sk_for_each(sk, node, head) {
240 if (net_eq(sock_net(sk), net) && (nlk_sk(sk)->pid == pid)) {
247 read_unlock(&nl_table_lock);
251 static inline struct hlist_head *nl_pid_hash_zalloc(size_t size)
253 if (size <= PAGE_SIZE)
254 return kzalloc(size, GFP_ATOMIC);
256 return (struct hlist_head *)
257 __get_free_pages(GFP_ATOMIC | __GFP_ZERO,
261 static inline void nl_pid_hash_free(struct hlist_head *table, size_t size)
263 if (size <= PAGE_SIZE)
266 free_pages((unsigned long)table, get_order(size));
269 static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow)
271 unsigned int omask, mask, shift;
273 struct hlist_head *otable, *table;
276 omask = mask = hash->mask;
277 osize = size = (mask + 1) * sizeof(*table);
281 if (++shift > hash->max_shift)
287 table = nl_pid_hash_zalloc(size);
291 otable = hash->table;
295 get_random_bytes(&hash->rnd, sizeof(hash->rnd));
297 for (i = 0; i <= omask; i++) {
299 struct hlist_node *node, *tmp;
301 sk_for_each_safe(sk, node, tmp, &otable[i])
302 __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid));
305 nl_pid_hash_free(otable, osize);
306 hash->rehash_time = jiffies + 10 * 60 * HZ;
310 static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len)
312 int avg = hash->entries >> hash->shift;
314 if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1))
317 if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) {
318 nl_pid_hash_rehash(hash, 0);
325 static const struct proto_ops netlink_ops;
328 netlink_update_listeners(struct sock *sk)
330 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
331 struct hlist_node *node;
335 for (i = 0; i < NLGRPLONGS(tbl->groups); i++) {
337 sk_for_each_bound(sk, node, &tbl->mc_list) {
338 if (i < NLGRPLONGS(nlk_sk(sk)->ngroups))
339 mask |= nlk_sk(sk)->groups[i];
341 tbl->listeners[i] = mask;
343 /* this function is only called with the netlink table "grabbed", which
344 * makes sure updates are visible before bind or setsockopt return. */
347 static int netlink_insert(struct sock *sk, struct net *net, u32 pid)
349 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
350 struct hlist_head *head;
351 int err = -EADDRINUSE;
353 struct hlist_node *node;
356 netlink_table_grab();
357 head = nl_pid_hashfn(hash, pid);
359 sk_for_each(osk, node, head) {
360 if (net_eq(sock_net(osk), net) && (nlk_sk(osk)->pid == pid))
372 if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX))
375 if (len && nl_pid_hash_dilute(hash, len))
376 head = nl_pid_hashfn(hash, pid);
378 nlk_sk(sk)->pid = pid;
379 sk_add_node(sk, head);
383 netlink_table_ungrab();
387 static void netlink_remove(struct sock *sk)
389 netlink_table_grab();
390 if (sk_del_node_init(sk))
391 nl_table[sk->sk_protocol].hash.entries--;
392 if (nlk_sk(sk)->subscriptions)
393 __sk_del_bind_node(sk);
394 netlink_table_ungrab();
397 static struct proto netlink_proto = {
399 .owner = THIS_MODULE,
400 .obj_size = sizeof(struct netlink_sock),
403 static int __netlink_create(struct net *net, struct socket *sock,
404 struct mutex *cb_mutex, int protocol)
407 struct netlink_sock *nlk;
409 sock->ops = &netlink_ops;
411 sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto);
415 sock_init_data(sock, sk);
419 nlk->cb_mutex = cb_mutex;
421 nlk->cb_mutex = &nlk->cb_def_mutex;
422 mutex_init(nlk->cb_mutex);
424 init_waitqueue_head(&nlk->wait);
426 sk->sk_destruct = netlink_sock_destruct;
427 sk->sk_protocol = protocol;
431 static int netlink_create(struct net *net, struct socket *sock, int protocol,
434 struct module *module = NULL;
435 struct mutex *cb_mutex;
436 struct netlink_sock *nlk;
439 sock->state = SS_UNCONNECTED;
441 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
442 return -ESOCKTNOSUPPORT;
444 if (protocol < 0 || protocol >= MAX_LINKS)
445 return -EPROTONOSUPPORT;
447 netlink_lock_table();
448 #ifdef CONFIG_MODULES
449 if (!nl_table[protocol].registered) {
450 netlink_unlock_table();
451 request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
452 netlink_lock_table();
455 if (nl_table[protocol].registered &&
456 try_module_get(nl_table[protocol].module))
457 module = nl_table[protocol].module;
459 err = -EPROTONOSUPPORT;
460 cb_mutex = nl_table[protocol].cb_mutex;
461 netlink_unlock_table();
466 err = __netlink_create(net, sock, cb_mutex, protocol);
471 sock_prot_inuse_add(net, &netlink_proto, 1);
474 nlk = nlk_sk(sock->sk);
475 nlk->module = module;
484 static int netlink_release(struct socket *sock)
486 struct sock *sk = sock->sk;
487 struct netlink_sock *nlk;
497 * OK. Socket is unlinked, any packets that arrive now
502 wake_up_interruptible_all(&nlk->wait);
504 skb_queue_purge(&sk->sk_write_queue);
507 struct netlink_notify n = {
509 .protocol = sk->sk_protocol,
512 atomic_notifier_call_chain(&netlink_chain,
513 NETLINK_URELEASE, &n);
516 module_put(nlk->module);
518 netlink_table_grab();
519 if (netlink_is_kernel(sk)) {
520 BUG_ON(nl_table[sk->sk_protocol].registered == 0);
521 if (--nl_table[sk->sk_protocol].registered == 0) {
522 kfree(nl_table[sk->sk_protocol].listeners);
523 nl_table[sk->sk_protocol].module = NULL;
524 nl_table[sk->sk_protocol].registered = 0;
526 } else if (nlk->subscriptions)
527 netlink_update_listeners(sk);
528 netlink_table_ungrab();
534 sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1);
540 static int netlink_autobind(struct socket *sock)
542 struct sock *sk = sock->sk;
543 struct net *net = sock_net(sk);
544 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
545 struct hlist_head *head;
547 struct hlist_node *node;
548 s32 pid = task_tgid_vnr(current);
550 static s32 rover = -4097;
554 netlink_table_grab();
555 head = nl_pid_hashfn(hash, pid);
556 sk_for_each(osk, node, head) {
557 if (!net_eq(sock_net(osk), net))
559 if (nlk_sk(osk)->pid == pid) {
560 /* Bind collision, search negative pid values. */
564 netlink_table_ungrab();
568 netlink_table_ungrab();
570 err = netlink_insert(sk, net, pid);
571 if (err == -EADDRINUSE)
574 /* If 2 threads race to autobind, that is fine. */
581 static inline int netlink_capable(struct socket *sock, unsigned int flag)
583 return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) ||
584 capable(CAP_NET_ADMIN);
588 netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions)
590 struct netlink_sock *nlk = nlk_sk(sk);
592 if (nlk->subscriptions && !subscriptions)
593 __sk_del_bind_node(sk);
594 else if (!nlk->subscriptions && subscriptions)
595 sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
596 nlk->subscriptions = subscriptions;
599 static int netlink_realloc_groups(struct sock *sk)
601 struct netlink_sock *nlk = nlk_sk(sk);
603 unsigned long *new_groups;
606 netlink_table_grab();
608 groups = nl_table[sk->sk_protocol].groups;
609 if (!nl_table[sk->sk_protocol].registered) {
614 if (nlk->ngroups >= groups)
617 new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC);
618 if (new_groups == NULL) {
622 memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0,
623 NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups));
625 nlk->groups = new_groups;
626 nlk->ngroups = groups;
628 netlink_table_ungrab();
632 static int netlink_bind(struct socket *sock, struct sockaddr *addr,
635 struct sock *sk = sock->sk;
636 struct net *net = sock_net(sk);
637 struct netlink_sock *nlk = nlk_sk(sk);
638 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
641 if (nladdr->nl_family != AF_NETLINK)
644 /* Only superuser is allowed to listen multicasts */
645 if (nladdr->nl_groups) {
646 if (!netlink_capable(sock, NL_NONROOT_RECV))
648 err = netlink_realloc_groups(sk);
654 if (nladdr->nl_pid != nlk->pid)
657 err = nladdr->nl_pid ?
658 netlink_insert(sk, net, nladdr->nl_pid) :
659 netlink_autobind(sock);
664 if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
667 netlink_table_grab();
668 netlink_update_subscriptions(sk, nlk->subscriptions +
669 hweight32(nladdr->nl_groups) -
670 hweight32(nlk->groups[0]));
671 nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups;
672 netlink_update_listeners(sk);
673 netlink_table_ungrab();
678 static int netlink_connect(struct socket *sock, struct sockaddr *addr,
682 struct sock *sk = sock->sk;
683 struct netlink_sock *nlk = nlk_sk(sk);
684 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
686 if (alen < sizeof(addr->sa_family))
689 if (addr->sa_family == AF_UNSPEC) {
690 sk->sk_state = NETLINK_UNCONNECTED;
695 if (addr->sa_family != AF_NETLINK)
698 /* Only superuser is allowed to send multicasts */
699 if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND))
703 err = netlink_autobind(sock);
706 sk->sk_state = NETLINK_CONNECTED;
707 nlk->dst_pid = nladdr->nl_pid;
708 nlk->dst_group = ffs(nladdr->nl_groups);
714 static int netlink_getname(struct socket *sock, struct sockaddr *addr,
715 int *addr_len, int peer)
717 struct sock *sk = sock->sk;
718 struct netlink_sock *nlk = nlk_sk(sk);
719 DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr);
721 nladdr->nl_family = AF_NETLINK;
723 *addr_len = sizeof(*nladdr);
726 nladdr->nl_pid = nlk->dst_pid;
727 nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
729 nladdr->nl_pid = nlk->pid;
730 nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
735 static void netlink_overrun(struct sock *sk)
737 struct netlink_sock *nlk = nlk_sk(sk);
739 if (!(nlk->flags & NETLINK_RECV_NO_ENOBUFS)) {
740 if (!test_and_set_bit(0, &nlk_sk(sk)->state)) {
741 sk->sk_err = ENOBUFS;
742 sk->sk_error_report(sk);
745 atomic_inc(&sk->sk_drops);
748 static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid)
751 struct netlink_sock *nlk;
753 sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, pid);
755 return ERR_PTR(-ECONNREFUSED);
757 /* Don't bother queuing skb if kernel socket has no input function */
759 if (sock->sk_state == NETLINK_CONNECTED &&
760 nlk->dst_pid != nlk_sk(ssk)->pid) {
762 return ERR_PTR(-ECONNREFUSED);
767 struct sock *netlink_getsockbyfilp(struct file *filp)
769 struct inode *inode = filp->f_path.dentry->d_inode;
772 if (!S_ISSOCK(inode->i_mode))
773 return ERR_PTR(-ENOTSOCK);
775 sock = SOCKET_I(inode)->sk;
776 if (sock->sk_family != AF_NETLINK)
777 return ERR_PTR(-EINVAL);
784 * Attach a skb to a netlink socket.
785 * The caller must hold a reference to the destination socket. On error, the
786 * reference is dropped. The skb is not send to the destination, just all
787 * all error checks are performed and memory in the queue is reserved.
789 * < 0: error. skb freed, reference to sock dropped.
791 * 1: repeat lookup - reference dropped while waiting for socket memory.
793 int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
794 long *timeo, struct sock *ssk)
796 struct netlink_sock *nlk;
800 if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
801 test_bit(0, &nlk->state)) {
802 DECLARE_WAITQUEUE(wait, current);
804 if (!ssk || netlink_is_kernel(ssk))
811 __set_current_state(TASK_INTERRUPTIBLE);
812 add_wait_queue(&nlk->wait, &wait);
814 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
815 test_bit(0, &nlk->state)) &&
816 !sock_flag(sk, SOCK_DEAD))
817 *timeo = schedule_timeout(*timeo);
819 __set_current_state(TASK_RUNNING);
820 remove_wait_queue(&nlk->wait, &wait);
823 if (signal_pending(current)) {
825 return sock_intr_errno(*timeo);
829 skb_set_owner_r(skb, sk);
833 int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
837 skb_queue_tail(&sk->sk_receive_queue, skb);
838 sk->sk_data_ready(sk, len);
843 void netlink_detachskb(struct sock *sk, struct sk_buff *skb)
849 static inline struct sk_buff *netlink_trim(struct sk_buff *skb,
856 delta = skb->end - skb->tail;
857 if (delta * 2 < skb->truesize)
860 if (skb_shared(skb)) {
861 struct sk_buff *nskb = skb_clone(skb, allocation);
868 if (!pskb_expand_head(skb, 0, -delta, allocation))
869 skb->truesize -= delta;
874 static inline void netlink_rcv_wake(struct sock *sk)
876 struct netlink_sock *nlk = nlk_sk(sk);
878 if (skb_queue_empty(&sk->sk_receive_queue))
879 clear_bit(0, &nlk->state);
880 if (!test_bit(0, &nlk->state))
881 wake_up_interruptible(&nlk->wait);
884 static inline int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb)
887 struct netlink_sock *nlk = nlk_sk(sk);
890 if (nlk->netlink_rcv != NULL) {
892 skb_set_owner_r(skb, sk);
893 nlk->netlink_rcv(skb);
900 int netlink_unicast(struct sock *ssk, struct sk_buff *skb,
901 u32 pid, int nonblock)
907 skb = netlink_trim(skb, gfp_any());
909 timeo = sock_sndtimeo(ssk, nonblock);
911 sk = netlink_getsockbypid(ssk, pid);
916 if (netlink_is_kernel(sk))
917 return netlink_unicast_kernel(sk, skb);
919 if (sk_filter(sk, skb)) {
926 err = netlink_attachskb(sk, skb, &timeo, ssk);
932 return netlink_sendskb(sk, skb);
934 EXPORT_SYMBOL(netlink_unicast);
936 int netlink_has_listeners(struct sock *sk, unsigned int group)
939 unsigned long *listeners;
941 BUG_ON(!netlink_is_kernel(sk));
944 listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners);
946 if (group - 1 < nl_table[sk->sk_protocol].groups)
947 res = test_bit(group - 1, listeners);
953 EXPORT_SYMBOL_GPL(netlink_has_listeners);
955 static inline int netlink_broadcast_deliver(struct sock *sk,
958 struct netlink_sock *nlk = nlk_sk(sk);
960 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
961 !test_bit(0, &nlk->state)) {
962 skb_set_owner_r(skb, sk);
963 skb_queue_tail(&sk->sk_receive_queue, skb);
964 sk->sk_data_ready(sk, skb->len);
965 return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf;
970 struct netlink_broadcast_data {
971 struct sock *exclude_sk;
976 int delivery_failure;
980 struct sk_buff *skb, *skb2;
981 int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data);
985 static inline int do_one_broadcast(struct sock *sk,
986 struct netlink_broadcast_data *p)
988 struct netlink_sock *nlk = nlk_sk(sk);
991 if (p->exclude_sk == sk)
994 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
995 !test_bit(p->group - 1, nlk->groups))
998 if (!net_eq(sock_net(sk), p->net))
1002 netlink_overrun(sk);
1007 if (p->skb2 == NULL) {
1008 if (skb_shared(p->skb)) {
1009 p->skb2 = skb_clone(p->skb, p->allocation);
1011 p->skb2 = skb_get(p->skb);
1013 * skb ownership may have been set when
1014 * delivered to a previous socket.
1016 skb_orphan(p->skb2);
1019 if (p->skb2 == NULL) {
1020 netlink_overrun(sk);
1021 /* Clone failed. Notify ALL listeners. */
1023 if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR)
1024 p->delivery_failure = 1;
1025 } else if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) {
1028 } else if (sk_filter(sk, p->skb2)) {
1031 } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) {
1032 netlink_overrun(sk);
1033 if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR)
1034 p->delivery_failure = 1;
1036 p->congested |= val;
1046 int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 pid,
1047 u32 group, gfp_t allocation,
1048 int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
1051 struct net *net = sock_net(ssk);
1052 struct netlink_broadcast_data info;
1053 struct hlist_node *node;
1056 skb = netlink_trim(skb, allocation);
1058 info.exclude_sk = ssk;
1063 info.delivery_failure = 0;
1066 info.allocation = allocation;
1069 info.tx_filter = filter;
1070 info.tx_data = filter_data;
1072 /* While we sleep in clone, do not allow to change socket list */
1074 netlink_lock_table();
1076 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
1077 do_one_broadcast(sk, &info);
1081 netlink_unlock_table();
1083 kfree_skb(info.skb2);
1085 if (info.delivery_failure)
1088 if (info.delivered) {
1089 if (info.congested && (allocation & __GFP_WAIT))
1095 EXPORT_SYMBOL(netlink_broadcast_filtered);
1097 int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
1098 u32 group, gfp_t allocation)
1100 return netlink_broadcast_filtered(ssk, skb, pid, group, allocation,
1103 EXPORT_SYMBOL(netlink_broadcast);
1105 struct netlink_set_err_data {
1106 struct sock *exclude_sk;
1112 static inline int do_one_set_err(struct sock *sk,
1113 struct netlink_set_err_data *p)
1115 struct netlink_sock *nlk = nlk_sk(sk);
1118 if (sk == p->exclude_sk)
1121 if (!net_eq(sock_net(sk), sock_net(p->exclude_sk)))
1124 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
1125 !test_bit(p->group - 1, nlk->groups))
1128 if (p->code == ENOBUFS && nlk->flags & NETLINK_RECV_NO_ENOBUFS) {
1133 sk->sk_err = p->code;
1134 sk->sk_error_report(sk);
1140 * netlink_set_err - report error to broadcast listeners
1141 * @ssk: the kernel netlink socket, as returned by netlink_kernel_create()
1142 * @pid: the PID of a process that we want to skip (if any)
1143 * @groups: the broadcast group that will notice the error
1144 * @code: error code, must be negative (as usual in kernelspace)
1146 * This function returns the number of broadcast listeners that have set the
1147 * NETLINK_RECV_NO_ENOBUFS socket option.
1149 int netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code)
1151 struct netlink_set_err_data info;
1152 struct hlist_node *node;
1156 info.exclude_sk = ssk;
1159 /* sk->sk_err wants a positive error value */
1162 read_lock(&nl_table_lock);
1164 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
1165 ret += do_one_set_err(sk, &info);
1167 read_unlock(&nl_table_lock);
1170 EXPORT_SYMBOL(netlink_set_err);
1172 /* must be called with netlink table grabbed */
1173 static void netlink_update_socket_mc(struct netlink_sock *nlk,
1177 int old, new = !!is_new, subscriptions;
1179 old = test_bit(group - 1, nlk->groups);
1180 subscriptions = nlk->subscriptions - old + new;
1182 __set_bit(group - 1, nlk->groups);
1184 __clear_bit(group - 1, nlk->groups);
1185 netlink_update_subscriptions(&nlk->sk, subscriptions);
1186 netlink_update_listeners(&nlk->sk);
1189 static int netlink_setsockopt(struct socket *sock, int level, int optname,
1190 char __user *optval, unsigned int optlen)
1192 struct sock *sk = sock->sk;
1193 struct netlink_sock *nlk = nlk_sk(sk);
1194 unsigned int val = 0;
1197 if (level != SOL_NETLINK)
1198 return -ENOPROTOOPT;
1200 if (optlen >= sizeof(int) &&
1201 get_user(val, (unsigned int __user *)optval))
1205 case NETLINK_PKTINFO:
1207 nlk->flags |= NETLINK_RECV_PKTINFO;
1209 nlk->flags &= ~NETLINK_RECV_PKTINFO;
1212 case NETLINK_ADD_MEMBERSHIP:
1213 case NETLINK_DROP_MEMBERSHIP: {
1214 if (!netlink_capable(sock, NL_NONROOT_RECV))
1216 err = netlink_realloc_groups(sk);
1219 if (!val || val - 1 >= nlk->ngroups)
1221 netlink_table_grab();
1222 netlink_update_socket_mc(nlk, val,
1223 optname == NETLINK_ADD_MEMBERSHIP);
1224 netlink_table_ungrab();
1228 case NETLINK_BROADCAST_ERROR:
1230 nlk->flags |= NETLINK_BROADCAST_SEND_ERROR;
1232 nlk->flags &= ~NETLINK_BROADCAST_SEND_ERROR;
1235 case NETLINK_NO_ENOBUFS:
1237 nlk->flags |= NETLINK_RECV_NO_ENOBUFS;
1238 clear_bit(0, &nlk->state);
1239 wake_up_interruptible(&nlk->wait);
1241 nlk->flags &= ~NETLINK_RECV_NO_ENOBUFS;
1250 static int netlink_getsockopt(struct socket *sock, int level, int optname,
1251 char __user *optval, int __user *optlen)
1253 struct sock *sk = sock->sk;
1254 struct netlink_sock *nlk = nlk_sk(sk);
1257 if (level != SOL_NETLINK)
1258 return -ENOPROTOOPT;
1260 if (get_user(len, optlen))
1266 case NETLINK_PKTINFO:
1267 if (len < sizeof(int))
1270 val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0;
1271 if (put_user(len, optlen) ||
1272 put_user(val, optval))
1276 case NETLINK_BROADCAST_ERROR:
1277 if (len < sizeof(int))
1280 val = nlk->flags & NETLINK_BROADCAST_SEND_ERROR ? 1 : 0;
1281 if (put_user(len, optlen) ||
1282 put_user(val, optval))
1286 case NETLINK_NO_ENOBUFS:
1287 if (len < sizeof(int))
1290 val = nlk->flags & NETLINK_RECV_NO_ENOBUFS ? 1 : 0;
1291 if (put_user(len, optlen) ||
1292 put_user(val, optval))
1302 static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
1304 struct nl_pktinfo info;
1306 info.group = NETLINK_CB(skb).dst_group;
1307 put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info);
1310 static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
1311 struct msghdr *msg, size_t len)
1313 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1314 struct sock *sk = sock->sk;
1315 struct netlink_sock *nlk = nlk_sk(sk);
1316 struct sockaddr_nl *addr = msg->msg_name;
1319 struct sk_buff *skb;
1321 struct scm_cookie scm;
1323 if (msg->msg_flags&MSG_OOB)
1326 if (NULL == siocb->scm)
1328 err = scm_send(sock, msg, siocb->scm);
1332 if (msg->msg_namelen) {
1333 if (addr->nl_family != AF_NETLINK)
1335 dst_pid = addr->nl_pid;
1336 dst_group = ffs(addr->nl_groups);
1337 if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND))
1340 dst_pid = nlk->dst_pid;
1341 dst_group = nlk->dst_group;
1345 err = netlink_autobind(sock);
1351 if (len > sk->sk_sndbuf - 32)
1354 skb = alloc_skb(len, GFP_KERNEL);
1358 NETLINK_CB(skb).pid = nlk->pid;
1359 NETLINK_CB(skb).dst_group = dst_group;
1360 NETLINK_CB(skb).loginuid = audit_get_loginuid(current);
1361 NETLINK_CB(skb).sessionid = audit_get_sessionid(current);
1362 security_task_getsecid(current, &(NETLINK_CB(skb).sid));
1363 memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
1365 /* What can I do? Netlink is asynchronous, so that
1366 we will have to save current capabilities to
1367 check them, when this message will be delivered
1368 to corresponding kernel module. --ANK (980802)
1372 if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
1377 err = security_netlink_send(sk, skb);
1384 atomic_inc(&skb->users);
1385 netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL);
1387 err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT);
1393 static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
1394 struct msghdr *msg, size_t len,
1397 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
1398 struct scm_cookie scm;
1399 struct sock *sk = sock->sk;
1400 struct netlink_sock *nlk = nlk_sk(sk);
1401 int noblock = flags&MSG_DONTWAIT;
1403 struct sk_buff *skb, *frag __maybe_unused = NULL;
1411 skb = skb_recv_datagram(sk, flags, noblock, &err);
1415 #ifdef CONFIG_COMPAT_NETLINK_MESSAGES
1416 if (unlikely(skb_shinfo(skb)->frag_list)) {
1417 bool need_compat = !!(flags & MSG_CMSG_COMPAT);
1420 * If this skb has a frag_list, then here that means that
1421 * we will have to use the frag_list skb for compat tasks
1422 * and the regular skb for non-compat tasks.
1424 * The skb might (and likely will) be cloned, so we can't
1425 * just reset frag_list and go on with things -- we need to
1426 * keep that. For the compat case that's easy -- simply get
1427 * a reference to the compat skb and free the regular one
1428 * including the frag. For the non-compat case, we need to
1429 * avoid sending the frag to the user -- so assign NULL but
1430 * restore it below before freeing the skb.
1433 struct sk_buff *compskb = skb_shinfo(skb)->frag_list;
1438 frag = skb_shinfo(skb)->frag_list;
1439 skb_shinfo(skb)->frag_list = NULL;
1444 msg->msg_namelen = 0;
1448 msg->msg_flags |= MSG_TRUNC;
1452 skb_reset_transport_header(skb);
1453 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
1455 if (msg->msg_name) {
1456 struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name;
1457 addr->nl_family = AF_NETLINK;
1459 addr->nl_pid = NETLINK_CB(skb).pid;
1460 addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group);
1461 msg->msg_namelen = sizeof(*addr);
1464 if (nlk->flags & NETLINK_RECV_PKTINFO)
1465 netlink_cmsg_recv_pktinfo(msg, skb);
1467 if (NULL == siocb->scm) {
1468 memset(&scm, 0, sizeof(scm));
1471 siocb->scm->creds = *NETLINK_CREDS(skb);
1472 if (flags & MSG_TRUNC)
1475 #ifdef CONFIG_COMPAT_NETLINK_MESSAGES
1476 skb_shinfo(skb)->frag_list = frag;
1479 skb_free_datagram(sk, skb);
1481 if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2)
1484 scm_recv(sock, msg, siocb->scm, flags);
1486 netlink_rcv_wake(sk);
1487 return err ? : copied;
1490 static void netlink_data_ready(struct sock *sk, int len)
1496 * We export these functions to other modules. They provide a
1497 * complete set of kernel non-blocking support for message
1502 netlink_kernel_create(struct net *net, int unit, unsigned int groups,
1503 void (*input)(struct sk_buff *skb),
1504 struct mutex *cb_mutex, struct module *module)
1506 struct socket *sock;
1508 struct netlink_sock *nlk;
1509 unsigned long *listeners = NULL;
1513 if (unit < 0 || unit >= MAX_LINKS)
1516 if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
1520 * We have to just have a reference on the net from sk, but don't
1521 * get_net it. Besides, we cannot get and then put the net here.
1522 * So we create one inside init_net and the move it to net.
1525 if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0)
1526 goto out_sock_release_nosk;
1529 sk_change_net(sk, net);
1534 listeners = kzalloc(NLGRPSZ(groups) + sizeof(struct listeners_rcu_head),
1537 goto out_sock_release;
1539 sk->sk_data_ready = netlink_data_ready;
1541 nlk_sk(sk)->netlink_rcv = input;
1543 if (netlink_insert(sk, net, 0))
1544 goto out_sock_release;
1547 nlk->flags |= NETLINK_KERNEL_SOCKET;
1549 netlink_table_grab();
1550 if (!nl_table[unit].registered) {
1551 nl_table[unit].groups = groups;
1552 nl_table[unit].listeners = listeners;
1553 nl_table[unit].cb_mutex = cb_mutex;
1554 nl_table[unit].module = module;
1555 nl_table[unit].registered = 1;
1558 nl_table[unit].registered++;
1560 netlink_table_ungrab();
1565 netlink_kernel_release(sk);
1568 out_sock_release_nosk:
1572 EXPORT_SYMBOL(netlink_kernel_create);
1576 netlink_kernel_release(struct sock *sk)
1578 sk_release_kernel(sk);
1580 EXPORT_SYMBOL(netlink_kernel_release);
1583 static void netlink_free_old_listeners(struct rcu_head *rcu_head)
1585 struct listeners_rcu_head *lrh;
1587 lrh = container_of(rcu_head, struct listeners_rcu_head, rcu_head);
1591 int __netlink_change_ngroups(struct sock *sk, unsigned int groups)
1593 unsigned long *listeners, *old = NULL;
1594 struct listeners_rcu_head *old_rcu_head;
1595 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
1600 if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) {
1601 listeners = kzalloc(NLGRPSZ(groups) +
1602 sizeof(struct listeners_rcu_head),
1606 old = tbl->listeners;
1607 memcpy(listeners, old, NLGRPSZ(tbl->groups));
1608 rcu_assign_pointer(tbl->listeners, listeners);
1610 * Free the old memory after an RCU grace period so we
1611 * don't leak it. We use call_rcu() here in order to be
1612 * able to call this function from atomic contexts. The
1613 * allocation of this memory will have reserved enough
1614 * space for struct listeners_rcu_head at the end.
1616 old_rcu_head = (void *)(tbl->listeners +
1617 NLGRPLONGS(tbl->groups));
1618 old_rcu_head->ptr = old;
1619 call_rcu(&old_rcu_head->rcu_head, netlink_free_old_listeners);
1621 tbl->groups = groups;
1627 * netlink_change_ngroups - change number of multicast groups
1629 * This changes the number of multicast groups that are available
1630 * on a certain netlink family. Note that it is not possible to
1631 * change the number of groups to below 32. Also note that it does
1632 * not implicitly call netlink_clear_multicast_users() when the
1633 * number of groups is reduced.
1635 * @sk: The kernel netlink socket, as returned by netlink_kernel_create().
1636 * @groups: The new number of groups.
1638 int netlink_change_ngroups(struct sock *sk, unsigned int groups)
1642 netlink_table_grab();
1643 err = __netlink_change_ngroups(sk, groups);
1644 netlink_table_ungrab();
1649 void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
1652 struct hlist_node *node;
1653 struct netlink_table *tbl = &nl_table[ksk->sk_protocol];
1655 sk_for_each_bound(sk, node, &tbl->mc_list)
1656 netlink_update_socket_mc(nlk_sk(sk), group, 0);
1660 * netlink_clear_multicast_users - kick off multicast listeners
1662 * This function removes all listeners from the given group.
1663 * @ksk: The kernel netlink socket, as returned by
1664 * netlink_kernel_create().
1665 * @group: The multicast group to clear.
1667 void netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
1669 netlink_table_grab();
1670 __netlink_clear_multicast_users(ksk, group);
1671 netlink_table_ungrab();
1674 void netlink_set_nonroot(int protocol, unsigned int flags)
1676 if ((unsigned int)protocol < MAX_LINKS)
1677 nl_table[protocol].nl_nonroot = flags;
1679 EXPORT_SYMBOL(netlink_set_nonroot);
1681 static void netlink_destroy_callback(struct netlink_callback *cb)
1688 * It looks a bit ugly.
1689 * It would be better to create kernel thread.
1692 static int netlink_dump(struct sock *sk)
1694 struct netlink_sock *nlk = nlk_sk(sk);
1695 struct netlink_callback *cb;
1696 struct sk_buff *skb;
1697 struct nlmsghdr *nlh;
1698 int len, err = -ENOBUFS;
1700 skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL);
1704 mutex_lock(nlk->cb_mutex);
1712 len = cb->dump(skb, cb);
1715 mutex_unlock(nlk->cb_mutex);
1717 if (sk_filter(sk, skb))
1720 skb_queue_tail(&sk->sk_receive_queue, skb);
1721 sk->sk_data_ready(sk, skb->len);
1726 nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI);
1730 memcpy(nlmsg_data(nlh), &len, sizeof(len));
1732 if (sk_filter(sk, skb))
1735 skb_queue_tail(&sk->sk_receive_queue, skb);
1736 sk->sk_data_ready(sk, skb->len);
1742 mutex_unlock(nlk->cb_mutex);
1744 netlink_destroy_callback(cb);
1748 mutex_unlock(nlk->cb_mutex);
1754 int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
1755 const struct nlmsghdr *nlh,
1756 int (*dump)(struct sk_buff *skb,
1757 struct netlink_callback *),
1758 int (*done)(struct netlink_callback *))
1760 struct netlink_callback *cb;
1762 struct netlink_sock *nlk;
1764 cb = kzalloc(sizeof(*cb), GFP_KERNEL);
1771 atomic_inc(&skb->users);
1774 sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).pid);
1776 netlink_destroy_callback(cb);
1777 return -ECONNREFUSED;
1780 /* A dump is in progress... */
1781 mutex_lock(nlk->cb_mutex);
1783 mutex_unlock(nlk->cb_mutex);
1784 netlink_destroy_callback(cb);
1789 mutex_unlock(nlk->cb_mutex);
1794 /* We successfully started a dump, by returning -EINTR we
1795 * signal not to send ACK even if it was requested.
1799 EXPORT_SYMBOL(netlink_dump_start);
1801 void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
1803 struct sk_buff *skb;
1804 struct nlmsghdr *rep;
1805 struct nlmsgerr *errmsg;
1806 size_t payload = sizeof(*errmsg);
1808 /* error messages get the original request appened */
1810 payload += nlmsg_len(nlh);
1812 skb = nlmsg_new(payload, GFP_KERNEL);
1816 sk = netlink_lookup(sock_net(in_skb->sk),
1817 in_skb->sk->sk_protocol,
1818 NETLINK_CB(in_skb).pid);
1820 sk->sk_err = ENOBUFS;
1821 sk->sk_error_report(sk);
1827 rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
1828 NLMSG_ERROR, payload, 0);
1829 errmsg = nlmsg_data(rep);
1830 errmsg->error = err;
1831 memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh));
1832 netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
1834 EXPORT_SYMBOL(netlink_ack);
1836 int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
1839 struct nlmsghdr *nlh;
1842 while (skb->len >= nlmsg_total_size(0)) {
1845 nlh = nlmsg_hdr(skb);
1848 if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
1851 /* Only requests are handled by the kernel */
1852 if (!(nlh->nlmsg_flags & NLM_F_REQUEST))
1855 /* Skip control messages */
1856 if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
1864 if (nlh->nlmsg_flags & NLM_F_ACK || err)
1865 netlink_ack(skb, nlh, err);
1868 msglen = NLMSG_ALIGN(nlh->nlmsg_len);
1869 if (msglen > skb->len)
1871 skb_pull(skb, msglen);
1876 EXPORT_SYMBOL(netlink_rcv_skb);
1879 * nlmsg_notify - send a notification netlink message
1880 * @sk: netlink socket to use
1881 * @skb: notification message
1882 * @pid: destination netlink pid for reports or 0
1883 * @group: destination multicast group or 0
1884 * @report: 1 to report back, 0 to disable
1885 * @flags: allocation flags
1887 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid,
1888 unsigned int group, int report, gfp_t flags)
1893 int exclude_pid = 0;
1896 atomic_inc(&skb->users);
1900 /* errors reported via destination sk->sk_err, but propagate
1901 * delivery errors if NETLINK_BROADCAST_ERROR flag is set */
1902 err = nlmsg_multicast(sk, skb, exclude_pid, group, flags);
1908 err2 = nlmsg_unicast(sk, skb, pid);
1909 if (!err || err == -ESRCH)
1915 EXPORT_SYMBOL(nlmsg_notify);
1917 #ifdef CONFIG_PROC_FS
1918 struct nl_seq_iter {
1919 struct seq_net_private p;
1924 static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos)
1926 struct nl_seq_iter *iter = seq->private;
1929 struct hlist_node *node;
1932 for (i = 0; i < MAX_LINKS; i++) {
1933 struct nl_pid_hash *hash = &nl_table[i].hash;
1935 for (j = 0; j <= hash->mask; j++) {
1936 sk_for_each(s, node, &hash->table[j]) {
1937 if (sock_net(s) != seq_file_net(seq))
1951 static void *netlink_seq_start(struct seq_file *seq, loff_t *pos)
1952 __acquires(nl_table_lock)
1954 read_lock(&nl_table_lock);
1955 return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN;
1958 static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1961 struct nl_seq_iter *iter;
1966 if (v == SEQ_START_TOKEN)
1967 return netlink_seq_socket_idx(seq, 0);
1969 iter = seq->private;
1973 } while (s && sock_net(s) != seq_file_net(seq));
1978 j = iter->hash_idx + 1;
1981 struct nl_pid_hash *hash = &nl_table[i].hash;
1983 for (; j <= hash->mask; j++) {
1984 s = sk_head(&hash->table[j]);
1985 while (s && sock_net(s) != seq_file_net(seq))
1995 } while (++i < MAX_LINKS);
2000 static void netlink_seq_stop(struct seq_file *seq, void *v)
2001 __releases(nl_table_lock)
2003 read_unlock(&nl_table_lock);
2007 static int netlink_seq_show(struct seq_file *seq, void *v)
2009 if (v == SEQ_START_TOKEN)
2011 "sk Eth Pid Groups "
2012 "Rmem Wmem Dump Locks Drops Inode\n");
2015 struct netlink_sock *nlk = nlk_sk(s);
2017 seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %-8d %-8d %-8lu\n",
2021 nlk->groups ? (u32)nlk->groups[0] : 0,
2022 sk_rmem_alloc_get(s),
2023 sk_wmem_alloc_get(s),
2025 atomic_read(&s->sk_refcnt),
2026 atomic_read(&s->sk_drops),
2034 static const struct seq_operations netlink_seq_ops = {
2035 .start = netlink_seq_start,
2036 .next = netlink_seq_next,
2037 .stop = netlink_seq_stop,
2038 .show = netlink_seq_show,
2042 static int netlink_seq_open(struct inode *inode, struct file *file)
2044 return seq_open_net(inode, file, &netlink_seq_ops,
2045 sizeof(struct nl_seq_iter));
2048 static const struct file_operations netlink_seq_fops = {
2049 .owner = THIS_MODULE,
2050 .open = netlink_seq_open,
2052 .llseek = seq_lseek,
2053 .release = seq_release_net,
2058 int netlink_register_notifier(struct notifier_block *nb)
2060 return atomic_notifier_chain_register(&netlink_chain, nb);
2062 EXPORT_SYMBOL(netlink_register_notifier);
2064 int netlink_unregister_notifier(struct notifier_block *nb)
2066 return atomic_notifier_chain_unregister(&netlink_chain, nb);
2068 EXPORT_SYMBOL(netlink_unregister_notifier);
2070 static const struct proto_ops netlink_ops = {
2071 .family = PF_NETLINK,
2072 .owner = THIS_MODULE,
2073 .release = netlink_release,
2074 .bind = netlink_bind,
2075 .connect = netlink_connect,
2076 .socketpair = sock_no_socketpair,
2077 .accept = sock_no_accept,
2078 .getname = netlink_getname,
2079 .poll = datagram_poll,
2080 .ioctl = sock_no_ioctl,
2081 .listen = sock_no_listen,
2082 .shutdown = sock_no_shutdown,
2083 .setsockopt = netlink_setsockopt,
2084 .getsockopt = netlink_getsockopt,
2085 .sendmsg = netlink_sendmsg,
2086 .recvmsg = netlink_recvmsg,
2087 .mmap = sock_no_mmap,
2088 .sendpage = sock_no_sendpage,
2091 static const struct net_proto_family netlink_family_ops = {
2092 .family = PF_NETLINK,
2093 .create = netlink_create,
2094 .owner = THIS_MODULE, /* for consistency 8) */
2097 static int __net_init netlink_net_init(struct net *net)
2099 #ifdef CONFIG_PROC_FS
2100 if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops))
2106 static void __net_exit netlink_net_exit(struct net *net)
2108 #ifdef CONFIG_PROC_FS
2109 proc_net_remove(net, "netlink");
2113 static struct pernet_operations __net_initdata netlink_net_ops = {
2114 .init = netlink_net_init,
2115 .exit = netlink_net_exit,
2118 static int __init netlink_proto_init(void)
2120 struct sk_buff *dummy_skb;
2122 unsigned long limit;
2124 int err = proto_register(&netlink_proto, 0);
2129 BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb));
2131 nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);
2135 if (totalram_pages >= (128 * 1024))
2136 limit = totalram_pages >> (21 - PAGE_SHIFT);
2138 limit = totalram_pages >> (23 - PAGE_SHIFT);
2140 order = get_bitmask_order(limit) - 1 + PAGE_SHIFT;
2141 limit = (1UL << order) / sizeof(struct hlist_head);
2142 order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1;
2144 for (i = 0; i < MAX_LINKS; i++) {
2145 struct nl_pid_hash *hash = &nl_table[i].hash;
2147 hash->table = nl_pid_hash_zalloc(1 * sizeof(*hash->table));
2150 nl_pid_hash_free(nl_table[i].hash.table,
2151 1 * sizeof(*hash->table));
2155 hash->max_shift = order;
2158 hash->rehash_time = jiffies;
2161 sock_register(&netlink_family_ops);
2162 register_pernet_subsys(&netlink_net_ops);
2163 /* The netlink device handler may be needed early. */
2168 panic("netlink_init: Cannot allocate nl_table\n");
2171 core_initcall(netlink_proto_init);