2 * NETLINK Kernel-user communication protocol.
4 * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk>
5 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
6 * Patrick McHardy <kaber@trash.net>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
13 * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith
14 * added netlink_proto_exit
15 * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br>
16 * use nlk_sk, as sk->protinfo is on a diet 8)
17 * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org>
18 * - inc module use count of module that owns
19 * the kernel socket in case userspace opens
20 * socket of same protocol
21 * - remove all module support, since netlink is
22 * mandatory if CONFIG_NET=y these days
25 #include <linux/module.h>
27 #include <linux/capability.h>
28 #include <linux/kernel.h>
29 #include <linux/init.h>
30 #include <linux/signal.h>
31 #include <linux/sched.h>
32 #include <linux/errno.h>
33 #include <linux/string.h>
34 #include <linux/stat.h>
35 #include <linux/socket.h>
37 #include <linux/fcntl.h>
38 #include <linux/termios.h>
39 #include <linux/sockios.h>
40 #include <linux/net.h>
42 #include <linux/slab.h>
43 #include <asm/uaccess.h>
44 #include <linux/skbuff.h>
45 #include <linux/netdevice.h>
46 #include <linux/rtnetlink.h>
47 #include <linux/proc_fs.h>
48 #include <linux/seq_file.h>
49 #include <linux/notifier.h>
50 #include <linux/security.h>
51 #include <linux/jhash.h>
52 #include <linux/jiffies.h>
53 #include <linux/random.h>
54 #include <linux/bitops.h>
56 #include <linux/types.h>
57 #include <linux/audit.h>
58 #include <linux/mutex.h>
59 #include <linux/vmalloc.h>
60 #include <asm/cacheflush.h>
62 #include <net/net_namespace.h>
65 #include <net/netlink.h>
67 #include "af_netlink.h"
71 unsigned long masks[0];
75 #define NETLINK_CONGESTED 0x0
78 #define NETLINK_KERNEL_SOCKET 0x1
79 #define NETLINK_RECV_PKTINFO 0x2
80 #define NETLINK_BROADCAST_SEND_ERROR 0x4
81 #define NETLINK_RECV_NO_ENOBUFS 0x8
83 static inline int netlink_is_kernel(struct sock *sk)
85 return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET;
88 struct netlink_table *nl_table;
89 EXPORT_SYMBOL_GPL(nl_table);
91 static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
93 static int netlink_dump(struct sock *sk);
94 static void netlink_skb_destructor(struct sk_buff *skb);
96 DEFINE_RWLOCK(nl_table_lock);
97 EXPORT_SYMBOL_GPL(nl_table_lock);
98 static atomic_t nl_table_users = ATOMIC_INIT(0);
100 #define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock));
102 static ATOMIC_NOTIFIER_HEAD(netlink_chain);
104 static inline u32 netlink_group_mask(u32 group)
106 return group ? 1 << (group - 1) : 0;
109 static inline struct hlist_head *nl_portid_hashfn(struct nl_portid_hash *hash, u32 portid)
111 return &hash->table[jhash_1word(portid, hash->rnd) & hash->mask];
114 static void netlink_overrun(struct sock *sk)
116 struct netlink_sock *nlk = nlk_sk(sk);
118 if (!(nlk->flags & NETLINK_RECV_NO_ENOBUFS)) {
119 if (!test_and_set_bit(NETLINK_CONGESTED, &nlk_sk(sk)->state)) {
120 sk->sk_err = ENOBUFS;
121 sk->sk_error_report(sk);
124 atomic_inc(&sk->sk_drops);
127 static void netlink_rcv_wake(struct sock *sk)
129 struct netlink_sock *nlk = nlk_sk(sk);
131 if (skb_queue_empty(&sk->sk_receive_queue))
132 clear_bit(NETLINK_CONGESTED, &nlk->state);
133 if (!test_bit(NETLINK_CONGESTED, &nlk->state))
134 wake_up_interruptible(&nlk->wait);
137 #ifdef CONFIG_NETLINK_MMAP
138 static bool netlink_skb_is_mmaped(const struct sk_buff *skb)
140 return NETLINK_CB(skb).flags & NETLINK_SKB_MMAPED;
143 static bool netlink_rx_is_mmaped(struct sock *sk)
145 return nlk_sk(sk)->rx_ring.pg_vec != NULL;
148 static bool netlink_tx_is_mmaped(struct sock *sk)
150 return nlk_sk(sk)->tx_ring.pg_vec != NULL;
153 static __pure struct page *pgvec_to_page(const void *addr)
155 if (is_vmalloc_addr(addr))
156 return vmalloc_to_page(addr);
158 return virt_to_page(addr);
161 static void free_pg_vec(void **pg_vec, unsigned int order, unsigned int len)
165 for (i = 0; i < len; i++) {
166 if (pg_vec[i] != NULL) {
167 if (is_vmalloc_addr(pg_vec[i]))
170 free_pages((unsigned long)pg_vec[i], order);
176 static void *alloc_one_pg_vec_page(unsigned long order)
179 gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | __GFP_ZERO |
180 __GFP_NOWARN | __GFP_NORETRY;
182 buffer = (void *)__get_free_pages(gfp_flags, order);
186 buffer = vzalloc((1 << order) * PAGE_SIZE);
190 gfp_flags &= ~__GFP_NORETRY;
191 return (void *)__get_free_pages(gfp_flags, order);
194 static void **alloc_pg_vec(struct netlink_sock *nlk,
195 struct nl_mmap_req *req, unsigned int order)
197 unsigned int block_nr = req->nm_block_nr;
201 pg_vec = kcalloc(block_nr, sizeof(void *), GFP_KERNEL);
205 for (i = 0; i < block_nr; i++) {
206 pg_vec[i] = ptr = alloc_one_pg_vec_page(order);
207 if (pg_vec[i] == NULL)
213 free_pg_vec(pg_vec, order, block_nr);
219 __netlink_set_ring(struct sock *sk, struct nl_mmap_req *req, bool tx_ring, void **pg_vec,
222 struct netlink_sock *nlk = nlk_sk(sk);
223 struct sk_buff_head *queue;
224 struct netlink_ring *ring;
226 queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
227 ring = tx_ring ? &nlk->tx_ring : &nlk->rx_ring;
229 spin_lock_bh(&queue->lock);
231 ring->frame_max = req->nm_frame_nr - 1;
233 ring->frame_size = req->nm_frame_size;
234 ring->pg_vec_pages = req->nm_block_size / PAGE_SIZE;
236 swap(ring->pg_vec_len, req->nm_block_nr);
237 swap(ring->pg_vec_order, order);
238 swap(ring->pg_vec, pg_vec);
240 __skb_queue_purge(queue);
241 spin_unlock_bh(&queue->lock);
243 WARN_ON(atomic_read(&nlk->mapped));
246 free_pg_vec(pg_vec, order, req->nm_block_nr);
249 static int netlink_set_ring(struct sock *sk, struct nl_mmap_req *req,
252 struct netlink_sock *nlk = nlk_sk(sk);
253 struct netlink_ring *ring;
254 void **pg_vec = NULL;
255 unsigned int order = 0;
257 ring = tx_ring ? &nlk->tx_ring : &nlk->rx_ring;
259 if (atomic_read(&nlk->mapped))
261 if (atomic_read(&ring->pending))
264 if (req->nm_block_nr) {
265 if (ring->pg_vec != NULL)
268 if ((int)req->nm_block_size <= 0)
270 if (!IS_ALIGNED(req->nm_block_size, PAGE_SIZE))
272 if (req->nm_frame_size < NL_MMAP_HDRLEN)
274 if (!IS_ALIGNED(req->nm_frame_size, NL_MMAP_MSG_ALIGNMENT))
277 ring->frames_per_block = req->nm_block_size /
279 if (ring->frames_per_block == 0)
281 if (ring->frames_per_block * req->nm_block_nr !=
285 order = get_order(req->nm_block_size);
286 pg_vec = alloc_pg_vec(nlk, req, order);
290 if (req->nm_frame_nr)
294 mutex_lock(&nlk->pg_vec_lock);
295 if (atomic_read(&nlk->mapped) == 0) {
296 __netlink_set_ring(sk, req, tx_ring, pg_vec, order);
297 mutex_unlock(&nlk->pg_vec_lock);
301 mutex_unlock(&nlk->pg_vec_lock);
304 free_pg_vec(pg_vec, order, req->nm_block_nr);
309 static void netlink_mm_open(struct vm_area_struct *vma)
311 struct file *file = vma->vm_file;
312 struct socket *sock = file->private_data;
313 struct sock *sk = sock->sk;
316 atomic_inc(&nlk_sk(sk)->mapped);
319 static void netlink_mm_close(struct vm_area_struct *vma)
321 struct file *file = vma->vm_file;
322 struct socket *sock = file->private_data;
323 struct sock *sk = sock->sk;
326 atomic_dec(&nlk_sk(sk)->mapped);
329 static const struct vm_operations_struct netlink_mmap_ops = {
330 .open = netlink_mm_open,
331 .close = netlink_mm_close,
334 static int netlink_mmap(struct file *file, struct socket *sock,
335 struct vm_area_struct *vma)
337 struct sock *sk = sock->sk;
338 struct netlink_sock *nlk = nlk_sk(sk);
339 struct netlink_ring *ring;
340 unsigned long start, size, expected;
347 mutex_lock(&nlk->pg_vec_lock);
350 for (ring = &nlk->rx_ring; ring <= &nlk->tx_ring; ring++) {
351 if (ring->pg_vec == NULL)
353 expected += ring->pg_vec_len * ring->pg_vec_pages * PAGE_SIZE;
359 size = vma->vm_end - vma->vm_start;
360 if (size != expected)
363 start = vma->vm_start;
364 for (ring = &nlk->rx_ring; ring <= &nlk->tx_ring; ring++) {
365 if (ring->pg_vec == NULL)
368 for (i = 0; i < ring->pg_vec_len; i++) {
370 void *kaddr = ring->pg_vec[i];
373 for (pg_num = 0; pg_num < ring->pg_vec_pages; pg_num++) {
374 page = pgvec_to_page(kaddr);
375 err = vm_insert_page(vma, start, page);
384 atomic_inc(&nlk->mapped);
385 vma->vm_ops = &netlink_mmap_ops;
388 mutex_unlock(&nlk->pg_vec_lock);
392 static void netlink_frame_flush_dcache(const struct nl_mmap_hdr *hdr, unsigned int nm_len)
394 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
395 struct page *p_start, *p_end;
397 /* First page is flushed through netlink_{get,set}_status */
398 p_start = pgvec_to_page(hdr + PAGE_SIZE);
399 p_end = pgvec_to_page((void *)hdr + NL_MMAP_HDRLEN + nm_len - 1);
400 while (p_start <= p_end) {
401 flush_dcache_page(p_start);
407 static enum nl_mmap_status netlink_get_status(const struct nl_mmap_hdr *hdr)
410 flush_dcache_page(pgvec_to_page(hdr));
411 return hdr->nm_status;
414 static void netlink_set_status(struct nl_mmap_hdr *hdr,
415 enum nl_mmap_status status)
418 hdr->nm_status = status;
419 flush_dcache_page(pgvec_to_page(hdr));
422 static struct nl_mmap_hdr *
423 __netlink_lookup_frame(const struct netlink_ring *ring, unsigned int pos)
425 unsigned int pg_vec_pos, frame_off;
427 pg_vec_pos = pos / ring->frames_per_block;
428 frame_off = pos % ring->frames_per_block;
430 return ring->pg_vec[pg_vec_pos] + (frame_off * ring->frame_size);
433 static struct nl_mmap_hdr *
434 netlink_lookup_frame(const struct netlink_ring *ring, unsigned int pos,
435 enum nl_mmap_status status)
437 struct nl_mmap_hdr *hdr;
439 hdr = __netlink_lookup_frame(ring, pos);
440 if (netlink_get_status(hdr) != status)
446 static struct nl_mmap_hdr *
447 netlink_current_frame(const struct netlink_ring *ring,
448 enum nl_mmap_status status)
450 return netlink_lookup_frame(ring, ring->head, status);
453 static struct nl_mmap_hdr *
454 netlink_previous_frame(const struct netlink_ring *ring,
455 enum nl_mmap_status status)
459 prev = ring->head ? ring->head - 1 : ring->frame_max;
460 return netlink_lookup_frame(ring, prev, status);
463 static void netlink_increment_head(struct netlink_ring *ring)
465 ring->head = ring->head != ring->frame_max ? ring->head + 1 : 0;
468 static void netlink_forward_ring(struct netlink_ring *ring)
470 unsigned int head = ring->head, pos = head;
471 const struct nl_mmap_hdr *hdr;
474 hdr = __netlink_lookup_frame(ring, pos);
475 if (hdr->nm_status == NL_MMAP_STATUS_UNUSED)
477 if (hdr->nm_status != NL_MMAP_STATUS_SKIP)
479 netlink_increment_head(ring);
480 } while (ring->head != head);
483 static bool netlink_dump_space(struct netlink_sock *nlk)
485 struct netlink_ring *ring = &nlk->rx_ring;
486 struct nl_mmap_hdr *hdr;
489 hdr = netlink_current_frame(ring, NL_MMAP_STATUS_UNUSED);
493 n = ring->head + ring->frame_max / 2;
494 if (n > ring->frame_max)
495 n -= ring->frame_max;
497 hdr = __netlink_lookup_frame(ring, n);
499 return hdr->nm_status == NL_MMAP_STATUS_UNUSED;
502 static unsigned int netlink_poll(struct file *file, struct socket *sock,
505 struct sock *sk = sock->sk;
506 struct netlink_sock *nlk = nlk_sk(sk);
510 if (nlk->rx_ring.pg_vec != NULL) {
511 /* Memory mapped sockets don't call recvmsg(), so flow control
512 * for dumps is performed here. A dump is allowed to continue
513 * if at least half the ring is unused.
515 while (nlk->cb != NULL && netlink_dump_space(nlk)) {
516 err = netlink_dump(sk);
519 sk->sk_error_report(sk);
523 netlink_rcv_wake(sk);
526 mask = datagram_poll(file, sock, wait);
528 spin_lock_bh(&sk->sk_receive_queue.lock);
529 if (nlk->rx_ring.pg_vec) {
530 netlink_forward_ring(&nlk->rx_ring);
531 if (!netlink_previous_frame(&nlk->rx_ring, NL_MMAP_STATUS_UNUSED))
532 mask |= POLLIN | POLLRDNORM;
534 spin_unlock_bh(&sk->sk_receive_queue.lock);
536 spin_lock_bh(&sk->sk_write_queue.lock);
537 if (nlk->tx_ring.pg_vec) {
538 if (netlink_current_frame(&nlk->tx_ring, NL_MMAP_STATUS_UNUSED))
539 mask |= POLLOUT | POLLWRNORM;
541 spin_unlock_bh(&sk->sk_write_queue.lock);
546 static struct nl_mmap_hdr *netlink_mmap_hdr(struct sk_buff *skb)
548 return (struct nl_mmap_hdr *)(skb->head - NL_MMAP_HDRLEN);
551 static void netlink_ring_setup_skb(struct sk_buff *skb, struct sock *sk,
552 struct netlink_ring *ring,
553 struct nl_mmap_hdr *hdr)
558 size = ring->frame_size - NL_MMAP_HDRLEN;
559 data = (void *)hdr + NL_MMAP_HDRLEN;
563 skb_reset_tail_pointer(skb);
564 skb->end = skb->tail + size;
567 skb->destructor = netlink_skb_destructor;
568 NETLINK_CB(skb).flags |= NETLINK_SKB_MMAPED;
569 NETLINK_CB(skb).sk = sk;
572 static int netlink_mmap_sendmsg(struct sock *sk, struct msghdr *msg,
573 u32 dst_portid, u32 dst_group,
574 struct sock_iocb *siocb)
576 struct netlink_sock *nlk = nlk_sk(sk);
577 struct netlink_ring *ring;
578 struct nl_mmap_hdr *hdr;
581 int err = 0, len = 0;
583 mutex_lock(&nlk->pg_vec_lock);
585 ring = &nlk->tx_ring;
586 maxlen = ring->frame_size - NL_MMAP_HDRLEN;
591 hdr = netlink_current_frame(ring, NL_MMAP_STATUS_VALID);
593 if (!(msg->msg_flags & MSG_DONTWAIT) &&
594 atomic_read(&nlk->tx_ring.pending))
599 nm_len = ACCESS_ONCE(hdr->nm_len);
600 if (nm_len > maxlen) {
605 netlink_frame_flush_dcache(hdr, nm_len);
607 skb = alloc_skb(nm_len, GFP_KERNEL);
612 __skb_put(skb, nm_len);
613 memcpy(skb->data, (void *)hdr + NL_MMAP_HDRLEN, nm_len);
614 netlink_set_status(hdr, NL_MMAP_STATUS_UNUSED);
616 netlink_increment_head(ring);
618 NETLINK_CB(skb).portid = nlk->portid;
619 NETLINK_CB(skb).dst_group = dst_group;
620 NETLINK_CB(skb).creds = siocb->scm->creds;
622 err = security_netlink_send(sk, skb);
628 if (unlikely(dst_group)) {
629 atomic_inc(&skb->users);
630 netlink_broadcast(sk, skb, dst_portid, dst_group,
633 err = netlink_unicast(sk, skb, dst_portid,
634 msg->msg_flags & MSG_DONTWAIT);
639 } while (hdr != NULL ||
640 (!(msg->msg_flags & MSG_DONTWAIT) &&
641 atomic_read(&nlk->tx_ring.pending)));
646 mutex_unlock(&nlk->pg_vec_lock);
650 static void netlink_queue_mmaped_skb(struct sock *sk, struct sk_buff *skb)
652 struct nl_mmap_hdr *hdr;
654 hdr = netlink_mmap_hdr(skb);
655 hdr->nm_len = skb->len;
656 hdr->nm_group = NETLINK_CB(skb).dst_group;
657 hdr->nm_pid = NETLINK_CB(skb).creds.pid;
658 hdr->nm_uid = from_kuid(sk_user_ns(sk), NETLINK_CB(skb).creds.uid);
659 hdr->nm_gid = from_kgid(sk_user_ns(sk), NETLINK_CB(skb).creds.gid);
660 netlink_frame_flush_dcache(hdr, hdr->nm_len);
661 netlink_set_status(hdr, NL_MMAP_STATUS_VALID);
663 NETLINK_CB(skb).flags |= NETLINK_SKB_DELIVERED;
667 static void netlink_ring_set_copied(struct sock *sk, struct sk_buff *skb)
669 struct netlink_sock *nlk = nlk_sk(sk);
670 struct netlink_ring *ring = &nlk->rx_ring;
671 struct nl_mmap_hdr *hdr;
673 spin_lock_bh(&sk->sk_receive_queue.lock);
674 hdr = netlink_current_frame(ring, NL_MMAP_STATUS_UNUSED);
676 spin_unlock_bh(&sk->sk_receive_queue.lock);
681 netlink_increment_head(ring);
682 __skb_queue_tail(&sk->sk_receive_queue, skb);
683 spin_unlock_bh(&sk->sk_receive_queue.lock);
685 hdr->nm_len = skb->len;
686 hdr->nm_group = NETLINK_CB(skb).dst_group;
687 hdr->nm_pid = NETLINK_CB(skb).creds.pid;
688 hdr->nm_uid = from_kuid(sk_user_ns(sk), NETLINK_CB(skb).creds.uid);
689 hdr->nm_gid = from_kgid(sk_user_ns(sk), NETLINK_CB(skb).creds.gid);
690 netlink_set_status(hdr, NL_MMAP_STATUS_COPY);
693 #else /* CONFIG_NETLINK_MMAP */
694 #define netlink_skb_is_mmaped(skb) false
695 #define netlink_rx_is_mmaped(sk) false
696 #define netlink_tx_is_mmaped(sk) false
697 #define netlink_mmap sock_no_mmap
698 #define netlink_poll datagram_poll
699 #define netlink_mmap_sendmsg(sk, msg, dst_portid, dst_group, siocb) 0
700 #endif /* CONFIG_NETLINK_MMAP */
702 static void netlink_destroy_callback(struct netlink_callback *cb)
708 static void netlink_consume_callback(struct netlink_callback *cb)
710 consume_skb(cb->skb);
714 static void netlink_skb_destructor(struct sk_buff *skb)
716 #ifdef CONFIG_NETLINK_MMAP
717 struct nl_mmap_hdr *hdr;
718 struct netlink_ring *ring;
721 /* If a packet from the kernel to userspace was freed because of an
722 * error without being delivered to userspace, the kernel must reset
723 * the status. In the direction userspace to kernel, the status is
724 * always reset here after the packet was processed and freed.
726 if (netlink_skb_is_mmaped(skb)) {
727 hdr = netlink_mmap_hdr(skb);
728 sk = NETLINK_CB(skb).sk;
730 if (NETLINK_CB(skb).flags & NETLINK_SKB_TX) {
731 netlink_set_status(hdr, NL_MMAP_STATUS_UNUSED);
732 ring = &nlk_sk(sk)->tx_ring;
734 if (!(NETLINK_CB(skb).flags & NETLINK_SKB_DELIVERED)) {
736 netlink_set_status(hdr, NL_MMAP_STATUS_VALID);
738 ring = &nlk_sk(sk)->rx_ring;
741 WARN_ON(atomic_read(&ring->pending) == 0);
742 atomic_dec(&ring->pending);
752 static void netlink_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
754 WARN_ON(skb->sk != NULL);
756 skb->destructor = netlink_skb_destructor;
757 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
758 sk_mem_charge(sk, skb->truesize);
761 static void netlink_sock_destruct(struct sock *sk)
763 struct netlink_sock *nlk = nlk_sk(sk);
767 nlk->cb->done(nlk->cb);
769 module_put(nlk->cb->module);
770 netlink_destroy_callback(nlk->cb);
773 skb_queue_purge(&sk->sk_receive_queue);
774 #ifdef CONFIG_NETLINK_MMAP
776 struct nl_mmap_req req;
778 memset(&req, 0, sizeof(req));
779 if (nlk->rx_ring.pg_vec)
780 __netlink_set_ring(sk, &req, false, NULL, 0);
781 memset(&req, 0, sizeof(req));
782 if (nlk->tx_ring.pg_vec)
783 __netlink_set_ring(sk, &req, true, NULL, 0);
785 #endif /* CONFIG_NETLINK_MMAP */
787 if (!sock_flag(sk, SOCK_DEAD)) {
788 printk(KERN_ERR "Freeing alive netlink socket %p\n", sk);
792 WARN_ON(atomic_read(&sk->sk_rmem_alloc));
793 WARN_ON(atomic_read(&sk->sk_wmem_alloc));
794 WARN_ON(nlk_sk(sk)->groups);
797 /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on
798 * SMP. Look, when several writers sleep and reader wakes them up, all but one
799 * immediately hit write lock and grab all the cpus. Exclusive sleep solves
800 * this, _but_ remember, it adds useless work on UP machines.
803 void netlink_table_grab(void)
804 __acquires(nl_table_lock)
808 write_lock_irq(&nl_table_lock);
810 if (atomic_read(&nl_table_users)) {
811 DECLARE_WAITQUEUE(wait, current);
813 add_wait_queue_exclusive(&nl_table_wait, &wait);
815 set_current_state(TASK_UNINTERRUPTIBLE);
816 if (atomic_read(&nl_table_users) == 0)
818 write_unlock_irq(&nl_table_lock);
820 write_lock_irq(&nl_table_lock);
823 __set_current_state(TASK_RUNNING);
824 remove_wait_queue(&nl_table_wait, &wait);
828 void netlink_table_ungrab(void)
829 __releases(nl_table_lock)
831 write_unlock_irq(&nl_table_lock);
832 wake_up(&nl_table_wait);
836 netlink_lock_table(void)
838 /* read_lock() synchronizes us to netlink_table_grab */
840 read_lock(&nl_table_lock);
841 atomic_inc(&nl_table_users);
842 read_unlock(&nl_table_lock);
846 netlink_unlock_table(void)
848 if (atomic_dec_and_test(&nl_table_users))
849 wake_up(&nl_table_wait);
852 static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid)
854 struct nl_portid_hash *hash = &nl_table[protocol].hash;
855 struct hlist_head *head;
858 read_lock(&nl_table_lock);
859 head = nl_portid_hashfn(hash, portid);
860 sk_for_each(sk, head) {
861 if (net_eq(sock_net(sk), net) && (nlk_sk(sk)->portid == portid)) {
868 read_unlock(&nl_table_lock);
872 static struct hlist_head *nl_portid_hash_zalloc(size_t size)
874 if (size <= PAGE_SIZE)
875 return kzalloc(size, GFP_ATOMIC);
877 return (struct hlist_head *)
878 __get_free_pages(GFP_ATOMIC | __GFP_ZERO,
882 static void nl_portid_hash_free(struct hlist_head *table, size_t size)
884 if (size <= PAGE_SIZE)
887 free_pages((unsigned long)table, get_order(size));
890 static int nl_portid_hash_rehash(struct nl_portid_hash *hash, int grow)
892 unsigned int omask, mask, shift;
894 struct hlist_head *otable, *table;
897 omask = mask = hash->mask;
898 osize = size = (mask + 1) * sizeof(*table);
902 if (++shift > hash->max_shift)
908 table = nl_portid_hash_zalloc(size);
912 otable = hash->table;
916 get_random_bytes(&hash->rnd, sizeof(hash->rnd));
918 for (i = 0; i <= omask; i++) {
920 struct hlist_node *tmp;
922 sk_for_each_safe(sk, tmp, &otable[i])
923 __sk_add_node(sk, nl_portid_hashfn(hash, nlk_sk(sk)->portid));
926 nl_portid_hash_free(otable, osize);
927 hash->rehash_time = jiffies + 10 * 60 * HZ;
931 static inline int nl_portid_hash_dilute(struct nl_portid_hash *hash, int len)
933 int avg = hash->entries >> hash->shift;
935 if (unlikely(avg > 1) && nl_portid_hash_rehash(hash, 1))
938 if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) {
939 nl_portid_hash_rehash(hash, 0);
946 static const struct proto_ops netlink_ops;
949 netlink_update_listeners(struct sock *sk)
951 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
954 struct listeners *listeners;
956 listeners = nl_deref_protected(tbl->listeners);
960 for (i = 0; i < NLGRPLONGS(tbl->groups); i++) {
962 sk_for_each_bound(sk, &tbl->mc_list) {
963 if (i < NLGRPLONGS(nlk_sk(sk)->ngroups))
964 mask |= nlk_sk(sk)->groups[i];
966 listeners->masks[i] = mask;
968 /* this function is only called with the netlink table "grabbed", which
969 * makes sure updates are visible before bind or setsockopt return. */
972 static int netlink_insert(struct sock *sk, struct net *net, u32 portid)
974 struct nl_portid_hash *hash = &nl_table[sk->sk_protocol].hash;
975 struct hlist_head *head;
976 int err = -EADDRINUSE;
980 netlink_table_grab();
981 head = nl_portid_hashfn(hash, portid);
983 sk_for_each(osk, head) {
984 if (net_eq(sock_net(osk), net) && (nlk_sk(osk)->portid == portid))
992 if (nlk_sk(sk)->portid)
996 if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX))
999 if (len && nl_portid_hash_dilute(hash, len))
1000 head = nl_portid_hashfn(hash, portid);
1002 nlk_sk(sk)->portid = portid;
1003 sk_add_node(sk, head);
1007 netlink_table_ungrab();
1011 static void netlink_remove(struct sock *sk)
1013 netlink_table_grab();
1014 if (sk_del_node_init(sk))
1015 nl_table[sk->sk_protocol].hash.entries--;
1016 if (nlk_sk(sk)->subscriptions)
1017 __sk_del_bind_node(sk);
1018 netlink_table_ungrab();
1021 static struct proto netlink_proto = {
1023 .owner = THIS_MODULE,
1024 .obj_size = sizeof(struct netlink_sock),
1027 static int __netlink_create(struct net *net, struct socket *sock,
1028 struct mutex *cb_mutex, int protocol)
1031 struct netlink_sock *nlk;
1033 sock->ops = &netlink_ops;
1035 sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto);
1039 sock_init_data(sock, sk);
1043 nlk->cb_mutex = cb_mutex;
1045 nlk->cb_mutex = &nlk->cb_def_mutex;
1046 mutex_init(nlk->cb_mutex);
1048 init_waitqueue_head(&nlk->wait);
1049 #ifdef CONFIG_NETLINK_MMAP
1050 mutex_init(&nlk->pg_vec_lock);
1053 sk->sk_destruct = netlink_sock_destruct;
1054 sk->sk_protocol = protocol;
1058 static int netlink_create(struct net *net, struct socket *sock, int protocol,
1061 struct module *module = NULL;
1062 struct mutex *cb_mutex;
1063 struct netlink_sock *nlk;
1064 void (*bind)(int group);
1067 sock->state = SS_UNCONNECTED;
1069 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1070 return -ESOCKTNOSUPPORT;
1072 if (protocol < 0 || protocol >= MAX_LINKS)
1073 return -EPROTONOSUPPORT;
1075 netlink_lock_table();
1076 #ifdef CONFIG_MODULES
1077 if (!nl_table[protocol].registered) {
1078 netlink_unlock_table();
1079 request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
1080 netlink_lock_table();
1083 if (nl_table[protocol].registered &&
1084 try_module_get(nl_table[protocol].module))
1085 module = nl_table[protocol].module;
1087 err = -EPROTONOSUPPORT;
1088 cb_mutex = nl_table[protocol].cb_mutex;
1089 bind = nl_table[protocol].bind;
1090 netlink_unlock_table();
1095 err = __netlink_create(net, sock, cb_mutex, protocol);
1100 sock_prot_inuse_add(net, &netlink_proto, 1);
1103 nlk = nlk_sk(sock->sk);
1104 nlk->module = module;
1105 nlk->netlink_bind = bind;
1114 static int netlink_release(struct socket *sock)
1116 struct sock *sk = sock->sk;
1117 struct netlink_sock *nlk;
1127 * OK. Socket is unlinked, any packets that arrive now
1132 wake_up_interruptible_all(&nlk->wait);
1134 skb_queue_purge(&sk->sk_write_queue);
1137 struct netlink_notify n = {
1138 .net = sock_net(sk),
1139 .protocol = sk->sk_protocol,
1140 .portid = nlk->portid,
1142 atomic_notifier_call_chain(&netlink_chain,
1143 NETLINK_URELEASE, &n);
1146 module_put(nlk->module);
1148 netlink_table_grab();
1149 if (netlink_is_kernel(sk)) {
1150 BUG_ON(nl_table[sk->sk_protocol].registered == 0);
1151 if (--nl_table[sk->sk_protocol].registered == 0) {
1152 struct listeners *old;
1154 old = nl_deref_protected(nl_table[sk->sk_protocol].listeners);
1155 RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL);
1156 kfree_rcu(old, rcu);
1157 nl_table[sk->sk_protocol].module = NULL;
1158 nl_table[sk->sk_protocol].bind = NULL;
1159 nl_table[sk->sk_protocol].flags = 0;
1160 nl_table[sk->sk_protocol].registered = 0;
1162 } else if (nlk->subscriptions) {
1163 netlink_update_listeners(sk);
1165 netlink_table_ungrab();
1171 sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1);
1177 static int netlink_autobind(struct socket *sock)
1179 struct sock *sk = sock->sk;
1180 struct net *net = sock_net(sk);
1181 struct nl_portid_hash *hash = &nl_table[sk->sk_protocol].hash;
1182 struct hlist_head *head;
1184 s32 portid = task_tgid_vnr(current);
1186 static s32 rover = -4097;
1190 netlink_table_grab();
1191 head = nl_portid_hashfn(hash, portid);
1192 sk_for_each(osk, head) {
1193 if (!net_eq(sock_net(osk), net))
1195 if (nlk_sk(osk)->portid == portid) {
1196 /* Bind collision, search negative portid values. */
1200 netlink_table_ungrab();
1204 netlink_table_ungrab();
1206 err = netlink_insert(sk, net, portid);
1207 if (err == -EADDRINUSE)
1210 /* If 2 threads race to autobind, that is fine. */
1218 * __netlink_ns_capable - General netlink message capability test
1219 * @nsp: NETLINK_CB of the socket buffer holding a netlink command from userspace.
1220 * @user_ns: The user namespace of the capability to use
1221 * @cap: The capability to use
1223 * Test to see if the opener of the socket we received the message
1224 * from had when the netlink socket was created and the sender of the
1225 * message has has the capability @cap in the user namespace @user_ns.
1227 bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
1228 struct user_namespace *user_ns, int cap)
1230 return ((nsp->flags & NETLINK_SKB_DST) ||
1231 file_ns_capable(nsp->sk->sk_socket->file, user_ns, cap)) &&
1232 ns_capable(user_ns, cap);
1234 EXPORT_SYMBOL(__netlink_ns_capable);
1237 * netlink_ns_capable - General netlink message capability test
1238 * @skb: socket buffer holding a netlink command from userspace
1239 * @user_ns: The user namespace of the capability to use
1240 * @cap: The capability to use
1242 * Test to see if the opener of the socket we received the message
1243 * from had when the netlink socket was created and the sender of the
1244 * message has has the capability @cap in the user namespace @user_ns.
1246 bool netlink_ns_capable(const struct sk_buff *skb,
1247 struct user_namespace *user_ns, int cap)
1249 return __netlink_ns_capable(&NETLINK_CB(skb), user_ns, cap);
1251 EXPORT_SYMBOL(netlink_ns_capable);
1254 * netlink_capable - Netlink global message capability test
1255 * @skb: socket buffer holding a netlink command from userspace
1256 * @cap: The capability to use
1258 * Test to see if the opener of the socket we received the message
1259 * from had when the netlink socket was created and the sender of the
1260 * message has has the capability @cap in all user namespaces.
1262 bool netlink_capable(const struct sk_buff *skb, int cap)
1264 return netlink_ns_capable(skb, &init_user_ns, cap);
1266 EXPORT_SYMBOL(netlink_capable);
1269 * netlink_net_capable - Netlink network namespace message capability test
1270 * @skb: socket buffer holding a netlink command from userspace
1271 * @cap: The capability to use
1273 * Test to see if the opener of the socket we received the message
1274 * from had when the netlink socket was created and the sender of the
1275 * message has has the capability @cap over the network namespace of
1276 * the socket we received the message from.
1278 bool netlink_net_capable(const struct sk_buff *skb, int cap)
1280 return netlink_ns_capable(skb, sock_net(skb->sk)->user_ns, cap);
1282 EXPORT_SYMBOL(netlink_net_capable);
1284 static inline int netlink_allowed(const struct socket *sock, unsigned int flag)
1286 return (nl_table[sock->sk->sk_protocol].flags & flag) ||
1287 ns_capable(sock_net(sock->sk)->user_ns, CAP_NET_ADMIN);
1291 netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions)
1293 struct netlink_sock *nlk = nlk_sk(sk);
1295 if (nlk->subscriptions && !subscriptions)
1296 __sk_del_bind_node(sk);
1297 else if (!nlk->subscriptions && subscriptions)
1298 sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
1299 nlk->subscriptions = subscriptions;
1302 static int netlink_realloc_groups(struct sock *sk)
1304 struct netlink_sock *nlk = nlk_sk(sk);
1305 unsigned int groups;
1306 unsigned long *new_groups;
1309 netlink_table_grab();
1311 groups = nl_table[sk->sk_protocol].groups;
1312 if (!nl_table[sk->sk_protocol].registered) {
1317 if (nlk->ngroups >= groups)
1320 new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC);
1321 if (new_groups == NULL) {
1325 memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0,
1326 NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups));
1328 nlk->groups = new_groups;
1329 nlk->ngroups = groups;
1331 netlink_table_ungrab();
1335 static int netlink_bind(struct socket *sock, struct sockaddr *addr,
1338 struct sock *sk = sock->sk;
1339 struct net *net = sock_net(sk);
1340 struct netlink_sock *nlk = nlk_sk(sk);
1341 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
1344 if (addr_len < sizeof(struct sockaddr_nl))
1347 if (nladdr->nl_family != AF_NETLINK)
1350 /* Only superuser is allowed to listen multicasts */
1351 if (nladdr->nl_groups) {
1352 if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV))
1354 err = netlink_realloc_groups(sk);
1360 if (nladdr->nl_pid != nlk->portid)
1363 err = nladdr->nl_pid ?
1364 netlink_insert(sk, net, nladdr->nl_pid) :
1365 netlink_autobind(sock);
1370 if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
1373 netlink_table_grab();
1374 netlink_update_subscriptions(sk, nlk->subscriptions +
1375 hweight32(nladdr->nl_groups) -
1376 hweight32(nlk->groups[0]));
1377 nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups;
1378 netlink_update_listeners(sk);
1379 netlink_table_ungrab();
1381 if (nlk->netlink_bind && nlk->groups[0]) {
1384 for (i=0; i<nlk->ngroups; i++) {
1385 if (test_bit(i, nlk->groups))
1386 nlk->netlink_bind(i);
1393 static int netlink_connect(struct socket *sock, struct sockaddr *addr,
1394 int alen, int flags)
1397 struct sock *sk = sock->sk;
1398 struct netlink_sock *nlk = nlk_sk(sk);
1399 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
1401 if (alen < sizeof(addr->sa_family))
1404 if (addr->sa_family == AF_UNSPEC) {
1405 sk->sk_state = NETLINK_UNCONNECTED;
1406 nlk->dst_portid = 0;
1410 if (addr->sa_family != AF_NETLINK)
1413 /* Only superuser is allowed to send multicasts */
1414 if (nladdr->nl_groups && !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
1418 err = netlink_autobind(sock);
1421 sk->sk_state = NETLINK_CONNECTED;
1422 nlk->dst_portid = nladdr->nl_pid;
1423 nlk->dst_group = ffs(nladdr->nl_groups);
1429 static int netlink_getname(struct socket *sock, struct sockaddr *addr,
1430 int *addr_len, int peer)
1432 struct sock *sk = sock->sk;
1433 struct netlink_sock *nlk = nlk_sk(sk);
1434 DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr);
1436 nladdr->nl_family = AF_NETLINK;
1438 *addr_len = sizeof(*nladdr);
1441 nladdr->nl_pid = nlk->dst_portid;
1442 nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
1444 nladdr->nl_pid = nlk->portid;
1445 nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
1450 static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid)
1453 struct netlink_sock *nlk;
1455 sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, portid);
1457 return ERR_PTR(-ECONNREFUSED);
1459 /* Don't bother queuing skb if kernel socket has no input function */
1461 if (sock->sk_state == NETLINK_CONNECTED &&
1462 nlk->dst_portid != nlk_sk(ssk)->portid) {
1464 return ERR_PTR(-ECONNREFUSED);
1469 struct sock *netlink_getsockbyfilp(struct file *filp)
1471 struct inode *inode = file_inode(filp);
1474 if (!S_ISSOCK(inode->i_mode))
1475 return ERR_PTR(-ENOTSOCK);
1477 sock = SOCKET_I(inode)->sk;
1478 if (sock->sk_family != AF_NETLINK)
1479 return ERR_PTR(-EINVAL);
1486 * Attach a skb to a netlink socket.
1487 * The caller must hold a reference to the destination socket. On error, the
1488 * reference is dropped. The skb is not send to the destination, just all
1489 * all error checks are performed and memory in the queue is reserved.
1491 * < 0: error. skb freed, reference to sock dropped.
1493 * 1: repeat lookup - reference dropped while waiting for socket memory.
1495 int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
1496 long *timeo, struct sock *ssk)
1498 struct netlink_sock *nlk;
1502 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
1503 test_bit(NETLINK_CONGESTED, &nlk->state)) &&
1504 !netlink_skb_is_mmaped(skb)) {
1505 DECLARE_WAITQUEUE(wait, current);
1507 if (!ssk || netlink_is_kernel(ssk))
1508 netlink_overrun(sk);
1514 __set_current_state(TASK_INTERRUPTIBLE);
1515 add_wait_queue(&nlk->wait, &wait);
1517 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
1518 test_bit(NETLINK_CONGESTED, &nlk->state)) &&
1519 !sock_flag(sk, SOCK_DEAD))
1520 *timeo = schedule_timeout(*timeo);
1522 __set_current_state(TASK_RUNNING);
1523 remove_wait_queue(&nlk->wait, &wait);
1526 if (signal_pending(current)) {
1528 return sock_intr_errno(*timeo);
1532 netlink_skb_set_owner_r(skb, sk);
1536 static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb)
1540 #ifdef CONFIG_NETLINK_MMAP
1541 if (netlink_skb_is_mmaped(skb))
1542 netlink_queue_mmaped_skb(sk, skb);
1543 else if (netlink_rx_is_mmaped(sk))
1544 netlink_ring_set_copied(sk, skb);
1546 #endif /* CONFIG_NETLINK_MMAP */
1547 skb_queue_tail(&sk->sk_receive_queue, skb);
1548 sk->sk_data_ready(sk, len);
1552 int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
1554 int len = __netlink_sendskb(sk, skb);
1560 void netlink_detachskb(struct sock *sk, struct sk_buff *skb)
1566 static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation)
1570 WARN_ON(skb->sk != NULL);
1571 if (netlink_skb_is_mmaped(skb))
1574 delta = skb->end - skb->tail;
1575 if (delta * 2 < skb->truesize)
1578 if (skb_shared(skb)) {
1579 struct sk_buff *nskb = skb_clone(skb, allocation);
1586 if (!pskb_expand_head(skb, 0, -delta, allocation))
1587 skb->truesize -= delta;
1592 static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb,
1596 struct netlink_sock *nlk = nlk_sk(sk);
1598 ret = -ECONNREFUSED;
1599 if (nlk->netlink_rcv != NULL) {
1601 netlink_skb_set_owner_r(skb, sk);
1602 NETLINK_CB(skb).sk = ssk;
1603 nlk->netlink_rcv(skb);
1612 int netlink_unicast(struct sock *ssk, struct sk_buff *skb,
1613 u32 portid, int nonblock)
1619 skb = netlink_trim(skb, gfp_any());
1621 timeo = sock_sndtimeo(ssk, nonblock);
1623 sk = netlink_getsockbyportid(ssk, portid);
1628 if (netlink_is_kernel(sk))
1629 return netlink_unicast_kernel(sk, skb, ssk);
1631 if (sk_filter(sk, skb)) {
1638 err = netlink_attachskb(sk, skb, &timeo, ssk);
1644 return netlink_sendskb(sk, skb);
1646 EXPORT_SYMBOL(netlink_unicast);
1648 struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size,
1649 u32 dst_portid, gfp_t gfp_mask)
1651 #ifdef CONFIG_NETLINK_MMAP
1652 struct sock *sk = NULL;
1653 struct sk_buff *skb;
1654 struct netlink_ring *ring;
1655 struct nl_mmap_hdr *hdr;
1656 unsigned int maxlen;
1658 sk = netlink_getsockbyportid(ssk, dst_portid);
1662 ring = &nlk_sk(sk)->rx_ring;
1663 /* fast-path without atomic ops for common case: non-mmaped receiver */
1664 if (ring->pg_vec == NULL)
1667 skb = alloc_skb_head(gfp_mask);
1671 spin_lock_bh(&sk->sk_receive_queue.lock);
1672 /* check again under lock */
1673 if (ring->pg_vec == NULL)
1676 maxlen = ring->frame_size - NL_MMAP_HDRLEN;
1680 netlink_forward_ring(ring);
1681 hdr = netlink_current_frame(ring, NL_MMAP_STATUS_UNUSED);
1684 netlink_ring_setup_skb(skb, sk, ring, hdr);
1685 netlink_set_status(hdr, NL_MMAP_STATUS_RESERVED);
1686 atomic_inc(&ring->pending);
1687 netlink_increment_head(ring);
1689 spin_unlock_bh(&sk->sk_receive_queue.lock);
1694 spin_unlock_bh(&sk->sk_receive_queue.lock);
1695 netlink_overrun(sk);
1702 spin_unlock_bh(&sk->sk_receive_queue.lock);
1707 return alloc_skb(size, gfp_mask);
1709 EXPORT_SYMBOL_GPL(netlink_alloc_skb);
1711 int netlink_has_listeners(struct sock *sk, unsigned int group)
1714 struct listeners *listeners;
1716 BUG_ON(!netlink_is_kernel(sk));
1719 listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners);
1721 if (listeners && group - 1 < nl_table[sk->sk_protocol].groups)
1722 res = test_bit(group - 1, listeners->masks);
1728 EXPORT_SYMBOL_GPL(netlink_has_listeners);
1730 static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb)
1732 struct netlink_sock *nlk = nlk_sk(sk);
1734 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
1735 !test_bit(NETLINK_CONGESTED, &nlk->state)) {
1736 netlink_skb_set_owner_r(skb, sk);
1737 __netlink_sendskb(sk, skb);
1738 return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1);
1743 struct netlink_broadcast_data {
1744 struct sock *exclude_sk;
1749 int delivery_failure;
1753 struct sk_buff *skb, *skb2;
1754 int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data);
1758 static int do_one_broadcast(struct sock *sk,
1759 struct netlink_broadcast_data *p)
1761 struct netlink_sock *nlk = nlk_sk(sk);
1764 if (p->exclude_sk == sk)
1767 if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups ||
1768 !test_bit(p->group - 1, nlk->groups))
1771 if (!net_eq(sock_net(sk), p->net))
1775 netlink_overrun(sk);
1780 if (p->skb2 == NULL) {
1781 if (skb_shared(p->skb)) {
1782 p->skb2 = skb_clone(p->skb, p->allocation);
1784 p->skb2 = skb_get(p->skb);
1786 * skb ownership may have been set when
1787 * delivered to a previous socket.
1789 skb_orphan(p->skb2);
1792 if (p->skb2 == NULL) {
1793 netlink_overrun(sk);
1794 /* Clone failed. Notify ALL listeners. */
1796 if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR)
1797 p->delivery_failure = 1;
1798 } else if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) {
1801 } else if (sk_filter(sk, p->skb2)) {
1804 } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) {
1805 netlink_overrun(sk);
1806 if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR)
1807 p->delivery_failure = 1;
1809 p->congested |= val;
1819 int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 portid,
1820 u32 group, gfp_t allocation,
1821 int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
1824 struct net *net = sock_net(ssk);
1825 struct netlink_broadcast_data info;
1828 skb = netlink_trim(skb, allocation);
1830 info.exclude_sk = ssk;
1832 info.portid = portid;
1835 info.delivery_failure = 0;
1838 info.allocation = allocation;
1841 info.tx_filter = filter;
1842 info.tx_data = filter_data;
1844 /* While we sleep in clone, do not allow to change socket list */
1846 netlink_lock_table();
1848 sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list)
1849 do_one_broadcast(sk, &info);
1853 netlink_unlock_table();
1855 if (info.delivery_failure) {
1856 kfree_skb(info.skb2);
1859 consume_skb(info.skb2);
1861 if (info.delivered) {
1862 if (info.congested && (allocation & __GFP_WAIT))
1868 EXPORT_SYMBOL(netlink_broadcast_filtered);
1870 int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 portid,
1871 u32 group, gfp_t allocation)
1873 return netlink_broadcast_filtered(ssk, skb, portid, group, allocation,
1876 EXPORT_SYMBOL(netlink_broadcast);
1878 struct netlink_set_err_data {
1879 struct sock *exclude_sk;
1885 static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p)
1887 struct netlink_sock *nlk = nlk_sk(sk);
1890 if (sk == p->exclude_sk)
1893 if (!net_eq(sock_net(sk), sock_net(p->exclude_sk)))
1896 if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups ||
1897 !test_bit(p->group - 1, nlk->groups))
1900 if (p->code == ENOBUFS && nlk->flags & NETLINK_RECV_NO_ENOBUFS) {
1905 sk->sk_err = p->code;
1906 sk->sk_error_report(sk);
1912 * netlink_set_err - report error to broadcast listeners
1913 * @ssk: the kernel netlink socket, as returned by netlink_kernel_create()
1914 * @portid: the PORTID of a process that we want to skip (if any)
1915 * @groups: the broadcast group that will notice the error
1916 * @code: error code, must be negative (as usual in kernelspace)
1918 * This function returns the number of broadcast listeners that have set the
1919 * NETLINK_RECV_NO_ENOBUFS socket option.
1921 int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code)
1923 struct netlink_set_err_data info;
1927 info.exclude_sk = ssk;
1928 info.portid = portid;
1930 /* sk->sk_err wants a positive error value */
1933 read_lock(&nl_table_lock);
1935 sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list)
1936 ret += do_one_set_err(sk, &info);
1938 read_unlock(&nl_table_lock);
1941 EXPORT_SYMBOL(netlink_set_err);
1943 /* must be called with netlink table grabbed */
1944 static void netlink_update_socket_mc(struct netlink_sock *nlk,
1948 int old, new = !!is_new, subscriptions;
1950 old = test_bit(group - 1, nlk->groups);
1951 subscriptions = nlk->subscriptions - old + new;
1953 __set_bit(group - 1, nlk->groups);
1955 __clear_bit(group - 1, nlk->groups);
1956 netlink_update_subscriptions(&nlk->sk, subscriptions);
1957 netlink_update_listeners(&nlk->sk);
1960 static int netlink_setsockopt(struct socket *sock, int level, int optname,
1961 char __user *optval, unsigned int optlen)
1963 struct sock *sk = sock->sk;
1964 struct netlink_sock *nlk = nlk_sk(sk);
1965 unsigned int val = 0;
1968 if (level != SOL_NETLINK)
1969 return -ENOPROTOOPT;
1971 if (optname != NETLINK_RX_RING && optname != NETLINK_TX_RING &&
1972 optlen >= sizeof(int) &&
1973 get_user(val, (unsigned int __user *)optval))
1977 case NETLINK_PKTINFO:
1979 nlk->flags |= NETLINK_RECV_PKTINFO;
1981 nlk->flags &= ~NETLINK_RECV_PKTINFO;
1984 case NETLINK_ADD_MEMBERSHIP:
1985 case NETLINK_DROP_MEMBERSHIP: {
1986 if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV))
1988 err = netlink_realloc_groups(sk);
1991 if (!val || val - 1 >= nlk->ngroups)
1993 netlink_table_grab();
1994 netlink_update_socket_mc(nlk, val,
1995 optname == NETLINK_ADD_MEMBERSHIP);
1996 netlink_table_ungrab();
1998 if (nlk->netlink_bind)
1999 nlk->netlink_bind(val);
2004 case NETLINK_BROADCAST_ERROR:
2006 nlk->flags |= NETLINK_BROADCAST_SEND_ERROR;
2008 nlk->flags &= ~NETLINK_BROADCAST_SEND_ERROR;
2011 case NETLINK_NO_ENOBUFS:
2013 nlk->flags |= NETLINK_RECV_NO_ENOBUFS;
2014 clear_bit(NETLINK_CONGESTED, &nlk->state);
2015 wake_up_interruptible(&nlk->wait);
2017 nlk->flags &= ~NETLINK_RECV_NO_ENOBUFS;
2021 #ifdef CONFIG_NETLINK_MMAP
2022 case NETLINK_RX_RING:
2023 case NETLINK_TX_RING: {
2024 struct nl_mmap_req req;
2026 /* Rings might consume more memory than queue limits, require
2029 if (!capable(CAP_NET_ADMIN))
2031 if (optlen < sizeof(req))
2033 if (copy_from_user(&req, optval, sizeof(req)))
2035 err = netlink_set_ring(sk, &req,
2036 optname == NETLINK_TX_RING);
2039 #endif /* CONFIG_NETLINK_MMAP */
2046 static int netlink_getsockopt(struct socket *sock, int level, int optname,
2047 char __user *optval, int __user *optlen)
2049 struct sock *sk = sock->sk;
2050 struct netlink_sock *nlk = nlk_sk(sk);
2053 if (level != SOL_NETLINK)
2054 return -ENOPROTOOPT;
2056 if (get_user(len, optlen))
2062 case NETLINK_PKTINFO:
2063 if (len < sizeof(int))
2066 val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0;
2067 if (put_user(len, optlen) ||
2068 put_user(val, optval))
2072 case NETLINK_BROADCAST_ERROR:
2073 if (len < sizeof(int))
2076 val = nlk->flags & NETLINK_BROADCAST_SEND_ERROR ? 1 : 0;
2077 if (put_user(len, optlen) ||
2078 put_user(val, optval))
2082 case NETLINK_NO_ENOBUFS:
2083 if (len < sizeof(int))
2086 val = nlk->flags & NETLINK_RECV_NO_ENOBUFS ? 1 : 0;
2087 if (put_user(len, optlen) ||
2088 put_user(val, optval))
2098 static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
2100 struct nl_pktinfo info;
2102 info.group = NETLINK_CB(skb).dst_group;
2103 put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info);
2106 static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
2107 struct msghdr *msg, size_t len)
2109 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
2110 struct sock *sk = sock->sk;
2111 struct netlink_sock *nlk = nlk_sk(sk);
2112 struct sockaddr_nl *addr = msg->msg_name;
2115 struct sk_buff *skb;
2117 struct scm_cookie scm;
2118 u32 netlink_skb_flags = 0;
2120 if (msg->msg_flags&MSG_OOB)
2123 if (NULL == siocb->scm)
2126 err = scm_send(sock, msg, siocb->scm, true);
2130 if (msg->msg_namelen) {
2132 if (addr->nl_family != AF_NETLINK)
2134 dst_portid = addr->nl_pid;
2135 dst_group = ffs(addr->nl_groups);
2137 if ((dst_group || dst_portid) &&
2138 !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
2140 netlink_skb_flags |= NETLINK_SKB_DST;
2142 dst_portid = nlk->dst_portid;
2143 dst_group = nlk->dst_group;
2147 err = netlink_autobind(sock);
2152 if (netlink_tx_is_mmaped(sk) &&
2153 msg->msg_iov->iov_base == NULL) {
2154 err = netlink_mmap_sendmsg(sk, msg, dst_portid, dst_group,
2160 if (len > sk->sk_sndbuf - 32)
2163 skb = alloc_skb(len, GFP_KERNEL);
2167 NETLINK_CB(skb).portid = nlk->portid;
2168 NETLINK_CB(skb).dst_group = dst_group;
2169 NETLINK_CB(skb).creds = siocb->scm->creds;
2170 NETLINK_CB(skb).flags = netlink_skb_flags;
2173 if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
2178 err = security_netlink_send(sk, skb);
2185 atomic_inc(&skb->users);
2186 netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL);
2188 err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags&MSG_DONTWAIT);
2191 scm_destroy(siocb->scm);
2195 static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
2196 struct msghdr *msg, size_t len,
2199 struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
2200 struct scm_cookie scm;
2201 struct sock *sk = sock->sk;
2202 struct netlink_sock *nlk = nlk_sk(sk);
2203 int noblock = flags&MSG_DONTWAIT;
2205 struct sk_buff *skb, *data_skb;
2213 skb = skb_recv_datagram(sk, flags, noblock, &err);
2219 #ifdef CONFIG_COMPAT_NETLINK_MESSAGES
2220 if (unlikely(skb_shinfo(skb)->frag_list)) {
2222 * If this skb has a frag_list, then here that means that we
2223 * will have to use the frag_list skb's data for compat tasks
2224 * and the regular skb's data for normal (non-compat) tasks.
2226 * If we need to send the compat skb, assign it to the
2227 * 'data_skb' variable so that it will be used below for data
2228 * copying. We keep 'skb' for everything else, including
2229 * freeing both later.
2231 if (flags & MSG_CMSG_COMPAT)
2232 data_skb = skb_shinfo(skb)->frag_list;
2236 copied = data_skb->len;
2238 msg->msg_flags |= MSG_TRUNC;
2242 skb_reset_transport_header(data_skb);
2243 err = skb_copy_datagram_iovec(data_skb, 0, msg->msg_iov, copied);
2245 if (msg->msg_name) {
2246 struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name;
2247 addr->nl_family = AF_NETLINK;
2249 addr->nl_pid = NETLINK_CB(skb).portid;
2250 addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group);
2251 msg->msg_namelen = sizeof(*addr);
2254 if (nlk->flags & NETLINK_RECV_PKTINFO)
2255 netlink_cmsg_recv_pktinfo(msg, skb);
2257 if (NULL == siocb->scm) {
2258 memset(&scm, 0, sizeof(scm));
2261 siocb->scm->creds = *NETLINK_CREDS(skb);
2262 if (flags & MSG_TRUNC)
2263 copied = data_skb->len;
2265 skb_free_datagram(sk, skb);
2267 if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) {
2268 ret = netlink_dump(sk);
2271 sk->sk_error_report(sk);
2275 scm_recv(sock, msg, siocb->scm, flags);
2277 netlink_rcv_wake(sk);
2278 return err ? : copied;
2281 static void netlink_data_ready(struct sock *sk, int len)
2287 * We export these functions to other modules. They provide a
2288 * complete set of kernel non-blocking support for message
2293 __netlink_kernel_create(struct net *net, int unit, struct module *module,
2294 struct netlink_kernel_cfg *cfg)
2296 struct socket *sock;
2298 struct netlink_sock *nlk;
2299 struct listeners *listeners = NULL;
2300 struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL;
2301 unsigned int groups;
2305 if (unit < 0 || unit >= MAX_LINKS)
2308 if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
2312 * We have to just have a reference on the net from sk, but don't
2313 * get_net it. Besides, we cannot get and then put the net here.
2314 * So we create one inside init_net and the move it to net.
2317 if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0)
2318 goto out_sock_release_nosk;
2321 sk_change_net(sk, net);
2323 if (!cfg || cfg->groups < 32)
2326 groups = cfg->groups;
2328 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
2330 goto out_sock_release;
2332 sk->sk_data_ready = netlink_data_ready;
2333 if (cfg && cfg->input)
2334 nlk_sk(sk)->netlink_rcv = cfg->input;
2336 if (netlink_insert(sk, net, 0))
2337 goto out_sock_release;
2340 nlk->flags |= NETLINK_KERNEL_SOCKET;
2342 netlink_table_grab();
2343 if (!nl_table[unit].registered) {
2344 nl_table[unit].groups = groups;
2345 rcu_assign_pointer(nl_table[unit].listeners, listeners);
2346 nl_table[unit].cb_mutex = cb_mutex;
2347 nl_table[unit].module = module;
2349 nl_table[unit].bind = cfg->bind;
2350 nl_table[unit].flags = cfg->flags;
2352 nl_table[unit].registered = 1;
2355 nl_table[unit].registered++;
2357 netlink_table_ungrab();
2362 netlink_kernel_release(sk);
2365 out_sock_release_nosk:
2369 EXPORT_SYMBOL(__netlink_kernel_create);
2372 netlink_kernel_release(struct sock *sk)
2374 sk_release_kernel(sk);
2376 EXPORT_SYMBOL(netlink_kernel_release);
2378 int __netlink_change_ngroups(struct sock *sk, unsigned int groups)
2380 struct listeners *new, *old;
2381 struct netlink_table *tbl = &nl_table[sk->sk_protocol];
2386 if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) {
2387 new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC);
2390 old = nl_deref_protected(tbl->listeners);
2391 memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups));
2392 rcu_assign_pointer(tbl->listeners, new);
2394 kfree_rcu(old, rcu);
2396 tbl->groups = groups;
2402 * netlink_change_ngroups - change number of multicast groups
2404 * This changes the number of multicast groups that are available
2405 * on a certain netlink family. Note that it is not possible to
2406 * change the number of groups to below 32. Also note that it does
2407 * not implicitly call netlink_clear_multicast_users() when the
2408 * number of groups is reduced.
2410 * @sk: The kernel netlink socket, as returned by netlink_kernel_create().
2411 * @groups: The new number of groups.
2413 int netlink_change_ngroups(struct sock *sk, unsigned int groups)
2417 netlink_table_grab();
2418 err = __netlink_change_ngroups(sk, groups);
2419 netlink_table_ungrab();
2424 void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
2427 struct netlink_table *tbl = &nl_table[ksk->sk_protocol];
2429 sk_for_each_bound(sk, &tbl->mc_list)
2430 netlink_update_socket_mc(nlk_sk(sk), group, 0);
2434 * netlink_clear_multicast_users - kick off multicast listeners
2436 * This function removes all listeners from the given group.
2437 * @ksk: The kernel netlink socket, as returned by
2438 * netlink_kernel_create().
2439 * @group: The multicast group to clear.
2441 void netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
2443 netlink_table_grab();
2444 __netlink_clear_multicast_users(ksk, group);
2445 netlink_table_ungrab();
2449 __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags)
2451 struct nlmsghdr *nlh;
2452 int size = nlmsg_msg_size(len);
2454 nlh = (struct nlmsghdr*)skb_put(skb, NLMSG_ALIGN(size));
2455 nlh->nlmsg_type = type;
2456 nlh->nlmsg_len = size;
2457 nlh->nlmsg_flags = flags;
2458 nlh->nlmsg_pid = portid;
2459 nlh->nlmsg_seq = seq;
2460 if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0)
2461 memset(nlmsg_data(nlh) + len, 0, NLMSG_ALIGN(size) - size);
2464 EXPORT_SYMBOL(__nlmsg_put);
2467 * It looks a bit ugly.
2468 * It would be better to create kernel thread.
2471 static int netlink_dump(struct sock *sk)
2473 struct netlink_sock *nlk = nlk_sk(sk);
2474 struct netlink_callback *cb;
2475 struct sk_buff *skb = NULL;
2476 struct nlmsghdr *nlh;
2477 int len, err = -ENOBUFS;
2480 mutex_lock(nlk->cb_mutex);
2488 alloc_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE);
2490 if (!netlink_rx_is_mmaped(sk) &&
2491 atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2493 skb = netlink_alloc_skb(sk, alloc_size, nlk->portid, GFP_KERNEL);
2496 netlink_skb_set_owner_r(skb, sk);
2498 len = cb->dump(skb, cb);
2501 mutex_unlock(nlk->cb_mutex);
2503 if (sk_filter(sk, skb))
2506 __netlink_sendskb(sk, skb);
2510 nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI);
2514 nl_dump_check_consistent(cb, nlh);
2516 memcpy(nlmsg_data(nlh), &len, sizeof(len));
2518 if (sk_filter(sk, skb))
2521 __netlink_sendskb(sk, skb);
2526 mutex_unlock(nlk->cb_mutex);
2528 module_put(cb->module);
2529 netlink_consume_callback(cb);
2533 mutex_unlock(nlk->cb_mutex);
2538 int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
2539 const struct nlmsghdr *nlh,
2540 struct netlink_dump_control *control)
2542 struct netlink_callback *cb;
2544 struct netlink_sock *nlk;
2547 cb = kzalloc(sizeof(*cb), GFP_KERNEL);
2551 /* Memory mapped dump requests need to be copied to avoid looping
2552 * on the pending state in netlink_mmap_sendmsg() while the CB hold
2553 * a reference to the skb.
2555 if (netlink_skb_is_mmaped(skb)) {
2556 skb = skb_copy(skb, GFP_KERNEL);
2562 atomic_inc(&skb->users);
2564 cb->dump = control->dump;
2565 cb->done = control->done;
2567 cb->data = control->data;
2568 cb->module = control->module;
2569 cb->min_dump_alloc = control->min_dump_alloc;
2572 sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).portid);
2574 netlink_destroy_callback(cb);
2575 return -ECONNREFUSED;
2579 mutex_lock(nlk->cb_mutex);
2580 /* A dump is in progress... */
2582 mutex_unlock(nlk->cb_mutex);
2583 netlink_destroy_callback(cb);
2587 /* add reference of module which cb->dump belongs to */
2588 if (!try_module_get(cb->module)) {
2589 mutex_unlock(nlk->cb_mutex);
2590 netlink_destroy_callback(cb);
2591 ret = -EPROTONOSUPPORT;
2596 mutex_unlock(nlk->cb_mutex);
2598 ret = netlink_dump(sk);
2605 /* We successfully started a dump, by returning -EINTR we
2606 * signal not to send ACK even if it was requested.
2610 EXPORT_SYMBOL(__netlink_dump_start);
2612 void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
2614 struct sk_buff *skb;
2615 struct nlmsghdr *rep;
2616 struct nlmsgerr *errmsg;
2617 size_t payload = sizeof(*errmsg);
2619 /* error messages get the original request appened */
2621 payload += nlmsg_len(nlh);
2623 skb = netlink_alloc_skb(in_skb->sk, nlmsg_total_size(payload),
2624 NETLINK_CB(in_skb).portid, GFP_KERNEL);
2628 sk = netlink_lookup(sock_net(in_skb->sk),
2629 in_skb->sk->sk_protocol,
2630 NETLINK_CB(in_skb).portid);
2632 sk->sk_err = ENOBUFS;
2633 sk->sk_error_report(sk);
2639 rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
2640 NLMSG_ERROR, payload, 0);
2641 errmsg = nlmsg_data(rep);
2642 errmsg->error = err;
2643 memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh));
2644 netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT);
2646 EXPORT_SYMBOL(netlink_ack);
2648 int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
2651 struct nlmsghdr *nlh;
2654 while (skb->len >= nlmsg_total_size(0)) {
2657 nlh = nlmsg_hdr(skb);
2660 if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
2663 /* Only requests are handled by the kernel */
2664 if (!(nlh->nlmsg_flags & NLM_F_REQUEST))
2667 /* Skip control messages */
2668 if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
2676 if (nlh->nlmsg_flags & NLM_F_ACK || err)
2677 netlink_ack(skb, nlh, err);
2680 msglen = NLMSG_ALIGN(nlh->nlmsg_len);
2681 if (msglen > skb->len)
2683 skb_pull(skb, msglen);
2688 EXPORT_SYMBOL(netlink_rcv_skb);
2691 * nlmsg_notify - send a notification netlink message
2692 * @sk: netlink socket to use
2693 * @skb: notification message
2694 * @portid: destination netlink portid for reports or 0
2695 * @group: destination multicast group or 0
2696 * @report: 1 to report back, 0 to disable
2697 * @flags: allocation flags
2699 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid,
2700 unsigned int group, int report, gfp_t flags)
2705 int exclude_portid = 0;
2708 atomic_inc(&skb->users);
2709 exclude_portid = portid;
2712 /* errors reported via destination sk->sk_err, but propagate
2713 * delivery errors if NETLINK_BROADCAST_ERROR flag is set */
2714 err = nlmsg_multicast(sk, skb, exclude_portid, group, flags);
2720 err2 = nlmsg_unicast(sk, skb, portid);
2721 if (!err || err == -ESRCH)
2727 EXPORT_SYMBOL(nlmsg_notify);
2729 #ifdef CONFIG_PROC_FS
2730 struct nl_seq_iter {
2731 struct seq_net_private p;
2736 static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos)
2738 struct nl_seq_iter *iter = seq->private;
2743 for (i = 0; i < MAX_LINKS; i++) {
2744 struct nl_portid_hash *hash = &nl_table[i].hash;
2746 for (j = 0; j <= hash->mask; j++) {
2747 sk_for_each(s, &hash->table[j]) {
2748 if (sock_net(s) != seq_file_net(seq))
2762 static void *netlink_seq_start(struct seq_file *seq, loff_t *pos)
2763 __acquires(nl_table_lock)
2765 read_lock(&nl_table_lock);
2766 return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN;
2769 static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2772 struct nl_seq_iter *iter;
2777 if (v == SEQ_START_TOKEN)
2778 return netlink_seq_socket_idx(seq, 0);
2780 iter = seq->private;
2784 } while (s && sock_net(s) != seq_file_net(seq));
2789 j = iter->hash_idx + 1;
2792 struct nl_portid_hash *hash = &nl_table[i].hash;
2794 for (; j <= hash->mask; j++) {
2795 s = sk_head(&hash->table[j]);
2796 while (s && sock_net(s) != seq_file_net(seq))
2806 } while (++i < MAX_LINKS);
2811 static void netlink_seq_stop(struct seq_file *seq, void *v)
2812 __releases(nl_table_lock)
2814 read_unlock(&nl_table_lock);
2818 static int netlink_seq_show(struct seq_file *seq, void *v)
2820 if (v == SEQ_START_TOKEN) {
2822 "sk Eth Pid Groups "
2823 "Rmem Wmem Dump Locks Drops Inode\n");
2826 struct netlink_sock *nlk = nlk_sk(s);
2828 seq_printf(seq, "%pK %-3d %-6u %08x %-8d %-8d %pK %-8d %-8d %-8lu\n",
2832 nlk->groups ? (u32)nlk->groups[0] : 0,
2833 sk_rmem_alloc_get(s),
2834 sk_wmem_alloc_get(s),
2836 atomic_read(&s->sk_refcnt),
2837 atomic_read(&s->sk_drops),
2845 static const struct seq_operations netlink_seq_ops = {
2846 .start = netlink_seq_start,
2847 .next = netlink_seq_next,
2848 .stop = netlink_seq_stop,
2849 .show = netlink_seq_show,
2853 static int netlink_seq_open(struct inode *inode, struct file *file)
2855 return seq_open_net(inode, file, &netlink_seq_ops,
2856 sizeof(struct nl_seq_iter));
2859 static const struct file_operations netlink_seq_fops = {
2860 .owner = THIS_MODULE,
2861 .open = netlink_seq_open,
2863 .llseek = seq_lseek,
2864 .release = seq_release_net,
2869 int netlink_register_notifier(struct notifier_block *nb)
2871 return atomic_notifier_chain_register(&netlink_chain, nb);
2873 EXPORT_SYMBOL(netlink_register_notifier);
2875 int netlink_unregister_notifier(struct notifier_block *nb)
2877 return atomic_notifier_chain_unregister(&netlink_chain, nb);
2879 EXPORT_SYMBOL(netlink_unregister_notifier);
2881 static const struct proto_ops netlink_ops = {
2882 .family = PF_NETLINK,
2883 .owner = THIS_MODULE,
2884 .release = netlink_release,
2885 .bind = netlink_bind,
2886 .connect = netlink_connect,
2887 .socketpair = sock_no_socketpair,
2888 .accept = sock_no_accept,
2889 .getname = netlink_getname,
2890 .poll = netlink_poll,
2891 .ioctl = sock_no_ioctl,
2892 .listen = sock_no_listen,
2893 .shutdown = sock_no_shutdown,
2894 .setsockopt = netlink_setsockopt,
2895 .getsockopt = netlink_getsockopt,
2896 .sendmsg = netlink_sendmsg,
2897 .recvmsg = netlink_recvmsg,
2898 .mmap = netlink_mmap,
2899 .sendpage = sock_no_sendpage,
2902 static const struct net_proto_family netlink_family_ops = {
2903 .family = PF_NETLINK,
2904 .create = netlink_create,
2905 .owner = THIS_MODULE, /* for consistency 8) */
2908 static int __net_init netlink_net_init(struct net *net)
2910 #ifdef CONFIG_PROC_FS
2911 if (!proc_create("netlink", 0, net->proc_net, &netlink_seq_fops))
2917 static void __net_exit netlink_net_exit(struct net *net)
2919 #ifdef CONFIG_PROC_FS
2920 remove_proc_entry("netlink", net->proc_net);
2924 static void __init netlink_add_usersock_entry(void)
2926 struct listeners *listeners;
2929 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
2931 panic("netlink_add_usersock_entry: Cannot allocate listeners\n");
2933 netlink_table_grab();
2935 nl_table[NETLINK_USERSOCK].groups = groups;
2936 rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners);
2937 nl_table[NETLINK_USERSOCK].module = THIS_MODULE;
2938 nl_table[NETLINK_USERSOCK].registered = 1;
2939 nl_table[NETLINK_USERSOCK].flags = NL_CFG_F_NONROOT_SEND;
2941 netlink_table_ungrab();
2944 static struct pernet_operations __net_initdata netlink_net_ops = {
2945 .init = netlink_net_init,
2946 .exit = netlink_net_exit,
2949 static int __init netlink_proto_init(void)
2952 unsigned long limit;
2954 int err = proto_register(&netlink_proto, 0);
2959 BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb));
2961 nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);
2965 if (totalram_pages >= (128 * 1024))
2966 limit = totalram_pages >> (21 - PAGE_SHIFT);
2968 limit = totalram_pages >> (23 - PAGE_SHIFT);
2970 order = get_bitmask_order(limit) - 1 + PAGE_SHIFT;
2971 limit = (1UL << order) / sizeof(struct hlist_head);
2972 order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1;
2974 for (i = 0; i < MAX_LINKS; i++) {
2975 struct nl_portid_hash *hash = &nl_table[i].hash;
2977 hash->table = nl_portid_hash_zalloc(1 * sizeof(*hash->table));
2980 nl_portid_hash_free(nl_table[i].hash.table,
2981 1 * sizeof(*hash->table));
2985 hash->max_shift = order;
2988 hash->rehash_time = jiffies;
2991 netlink_add_usersock_entry();
2993 sock_register(&netlink_family_ops);
2994 register_pernet_subsys(&netlink_net_ops);
2995 /* The netlink device handler may be needed early. */
3000 panic("netlink_init: Cannot allocate nl_table\n");
3003 core_initcall(netlink_proto_init);