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![Eric Paris](/assets/img/avatar_default.png)
Previously I added sessionid output to all audit messages where it was available but we still didn't know the sessionid of the sender of netlink messages. This patch adds that information to netlink messages so we can audit who sent netlink messages. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
1993 lines
44 KiB
C
1993 lines
44 KiB
C
/*
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* NETLINK Kernel-user communication protocol.
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*
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* Authors: Alan Cox <alan@redhat.com>
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* Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith
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* added netlink_proto_exit
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* Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br>
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* use nlk_sk, as sk->protinfo is on a diet 8)
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* Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org>
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* - inc module use count of module that owns
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* the kernel socket in case userspace opens
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* socket of same protocol
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* - remove all module support, since netlink is
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* mandatory if CONFIG_NET=y these days
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*/
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#include <linux/module.h>
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#include <linux/capability.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/stat.h>
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#include <linux/socket.h>
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#include <linux/un.h>
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#include <linux/fcntl.h>
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#include <linux/termios.h>
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#include <linux/sockios.h>
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#include <linux/net.h>
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#include <linux/fs.h>
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#include <linux/slab.h>
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#include <asm/uaccess.h>
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#include <linux/skbuff.h>
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#include <linux/netdevice.h>
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#include <linux/rtnetlink.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/notifier.h>
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#include <linux/security.h>
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#include <linux/jhash.h>
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#include <linux/jiffies.h>
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#include <linux/random.h>
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#include <linux/bitops.h>
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#include <linux/mm.h>
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#include <linux/types.h>
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#include <linux/audit.h>
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#include <linux/mutex.h>
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#include <net/net_namespace.h>
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#include <net/sock.h>
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#include <net/scm.h>
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#include <net/netlink.h>
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#define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8)
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#define NLGRPLONGS(x) (NLGRPSZ(x)/sizeof(unsigned long))
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struct netlink_sock {
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/* struct sock has to be the first member of netlink_sock */
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struct sock sk;
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u32 pid;
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u32 dst_pid;
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u32 dst_group;
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u32 flags;
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u32 subscriptions;
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u32 ngroups;
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unsigned long *groups;
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unsigned long state;
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wait_queue_head_t wait;
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struct netlink_callback *cb;
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struct mutex *cb_mutex;
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struct mutex cb_def_mutex;
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void (*netlink_rcv)(struct sk_buff *skb);
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struct module *module;
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};
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#define NETLINK_KERNEL_SOCKET 0x1
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#define NETLINK_RECV_PKTINFO 0x2
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static inline struct netlink_sock *nlk_sk(struct sock *sk)
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{
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return container_of(sk, struct netlink_sock, sk);
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}
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static inline int netlink_is_kernel(struct sock *sk)
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{
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return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET;
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}
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struct nl_pid_hash {
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struct hlist_head *table;
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unsigned long rehash_time;
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unsigned int mask;
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unsigned int shift;
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unsigned int entries;
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unsigned int max_shift;
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u32 rnd;
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};
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struct netlink_table {
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struct nl_pid_hash hash;
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struct hlist_head mc_list;
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unsigned long *listeners;
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unsigned int nl_nonroot;
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unsigned int groups;
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struct mutex *cb_mutex;
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struct module *module;
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int registered;
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};
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static struct netlink_table *nl_table;
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static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
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static int netlink_dump(struct sock *sk);
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static void netlink_destroy_callback(struct netlink_callback *cb);
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static DEFINE_RWLOCK(nl_table_lock);
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static atomic_t nl_table_users = ATOMIC_INIT(0);
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static ATOMIC_NOTIFIER_HEAD(netlink_chain);
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static u32 netlink_group_mask(u32 group)
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{
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return group ? 1 << (group - 1) : 0;
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}
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static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid)
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{
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return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask];
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}
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static void netlink_sock_destruct(struct sock *sk)
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{
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struct netlink_sock *nlk = nlk_sk(sk);
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if (nlk->cb) {
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if (nlk->cb->done)
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nlk->cb->done(nlk->cb);
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netlink_destroy_callback(nlk->cb);
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}
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skb_queue_purge(&sk->sk_receive_queue);
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if (!sock_flag(sk, SOCK_DEAD)) {
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printk(KERN_ERR "Freeing alive netlink socket %p\n", sk);
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return;
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}
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BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc));
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BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
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BUG_TRAP(!nlk_sk(sk)->groups);
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}
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/* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on
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* SMP. Look, when several writers sleep and reader wakes them up, all but one
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* immediately hit write lock and grab all the cpus. Exclusive sleep solves
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* this, _but_ remember, it adds useless work on UP machines.
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*/
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static void netlink_table_grab(void)
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__acquires(nl_table_lock)
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{
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write_lock_irq(&nl_table_lock);
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if (atomic_read(&nl_table_users)) {
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DECLARE_WAITQUEUE(wait, current);
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add_wait_queue_exclusive(&nl_table_wait, &wait);
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for (;;) {
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set_current_state(TASK_UNINTERRUPTIBLE);
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if (atomic_read(&nl_table_users) == 0)
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break;
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write_unlock_irq(&nl_table_lock);
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schedule();
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write_lock_irq(&nl_table_lock);
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}
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__set_current_state(TASK_RUNNING);
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remove_wait_queue(&nl_table_wait, &wait);
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}
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}
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static void netlink_table_ungrab(void)
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__releases(nl_table_lock)
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{
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write_unlock_irq(&nl_table_lock);
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wake_up(&nl_table_wait);
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}
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static inline void
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netlink_lock_table(void)
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{
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/* read_lock() synchronizes us to netlink_table_grab */
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read_lock(&nl_table_lock);
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atomic_inc(&nl_table_users);
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read_unlock(&nl_table_lock);
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}
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static inline void
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netlink_unlock_table(void)
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{
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if (atomic_dec_and_test(&nl_table_users))
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wake_up(&nl_table_wait);
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}
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static inline struct sock *netlink_lookup(struct net *net, int protocol,
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u32 pid)
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{
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struct nl_pid_hash *hash = &nl_table[protocol].hash;
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struct hlist_head *head;
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struct sock *sk;
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struct hlist_node *node;
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read_lock(&nl_table_lock);
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head = nl_pid_hashfn(hash, pid);
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sk_for_each(sk, node, head) {
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if (net_eq(sock_net(sk), net) && (nlk_sk(sk)->pid == pid)) {
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sock_hold(sk);
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goto found;
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}
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}
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sk = NULL;
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found:
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read_unlock(&nl_table_lock);
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return sk;
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}
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static inline struct hlist_head *nl_pid_hash_zalloc(size_t size)
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{
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if (size <= PAGE_SIZE)
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return kzalloc(size, GFP_ATOMIC);
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else
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return (struct hlist_head *)
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__get_free_pages(GFP_ATOMIC | __GFP_ZERO,
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get_order(size));
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}
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static inline void nl_pid_hash_free(struct hlist_head *table, size_t size)
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{
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if (size <= PAGE_SIZE)
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kfree(table);
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else
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free_pages((unsigned long)table, get_order(size));
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}
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static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow)
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{
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unsigned int omask, mask, shift;
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size_t osize, size;
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struct hlist_head *otable, *table;
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int i;
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omask = mask = hash->mask;
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osize = size = (mask + 1) * sizeof(*table);
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shift = hash->shift;
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if (grow) {
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if (++shift > hash->max_shift)
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return 0;
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mask = mask * 2 + 1;
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size *= 2;
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}
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table = nl_pid_hash_zalloc(size);
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if (!table)
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return 0;
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otable = hash->table;
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hash->table = table;
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hash->mask = mask;
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hash->shift = shift;
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get_random_bytes(&hash->rnd, sizeof(hash->rnd));
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for (i = 0; i <= omask; i++) {
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struct sock *sk;
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struct hlist_node *node, *tmp;
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sk_for_each_safe(sk, node, tmp, &otable[i])
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__sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid));
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}
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nl_pid_hash_free(otable, osize);
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hash->rehash_time = jiffies + 10 * 60 * HZ;
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return 1;
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}
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static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len)
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{
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int avg = hash->entries >> hash->shift;
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if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1))
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return 1;
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if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) {
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nl_pid_hash_rehash(hash, 0);
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return 1;
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}
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return 0;
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}
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static const struct proto_ops netlink_ops;
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static void
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netlink_update_listeners(struct sock *sk)
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{
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struct netlink_table *tbl = &nl_table[sk->sk_protocol];
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struct hlist_node *node;
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unsigned long mask;
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unsigned int i;
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for (i = 0; i < NLGRPLONGS(tbl->groups); i++) {
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mask = 0;
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sk_for_each_bound(sk, node, &tbl->mc_list) {
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if (i < NLGRPLONGS(nlk_sk(sk)->ngroups))
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mask |= nlk_sk(sk)->groups[i];
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}
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tbl->listeners[i] = mask;
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}
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/* this function is only called with the netlink table "grabbed", which
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* makes sure updates are visible before bind or setsockopt return. */
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}
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static int netlink_insert(struct sock *sk, struct net *net, u32 pid)
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{
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struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
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struct hlist_head *head;
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int err = -EADDRINUSE;
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struct sock *osk;
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struct hlist_node *node;
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int len;
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netlink_table_grab();
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head = nl_pid_hashfn(hash, pid);
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len = 0;
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sk_for_each(osk, node, head) {
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if (net_eq(sock_net(osk), net) && (nlk_sk(osk)->pid == pid))
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break;
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len++;
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}
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if (node)
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goto err;
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err = -EBUSY;
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if (nlk_sk(sk)->pid)
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goto err;
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err = -ENOMEM;
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if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX))
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goto err;
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if (len && nl_pid_hash_dilute(hash, len))
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head = nl_pid_hashfn(hash, pid);
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hash->entries++;
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nlk_sk(sk)->pid = pid;
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sk_add_node(sk, head);
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err = 0;
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err:
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netlink_table_ungrab();
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return err;
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}
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static void netlink_remove(struct sock *sk)
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{
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netlink_table_grab();
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if (sk_del_node_init(sk))
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nl_table[sk->sk_protocol].hash.entries--;
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if (nlk_sk(sk)->subscriptions)
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__sk_del_bind_node(sk);
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netlink_table_ungrab();
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}
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static struct proto netlink_proto = {
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.name = "NETLINK",
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.owner = THIS_MODULE,
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.obj_size = sizeof(struct netlink_sock),
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};
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static int __netlink_create(struct net *net, struct socket *sock,
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struct mutex *cb_mutex, int protocol)
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{
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struct sock *sk;
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struct netlink_sock *nlk;
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sock->ops = &netlink_ops;
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sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto);
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if (!sk)
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return -ENOMEM;
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sock_init_data(sock, sk);
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nlk = nlk_sk(sk);
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if (cb_mutex)
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nlk->cb_mutex = cb_mutex;
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else {
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nlk->cb_mutex = &nlk->cb_def_mutex;
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mutex_init(nlk->cb_mutex);
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}
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init_waitqueue_head(&nlk->wait);
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sk->sk_destruct = netlink_sock_destruct;
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sk->sk_protocol = protocol;
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return 0;
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}
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static int netlink_create(struct net *net, struct socket *sock, int protocol)
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{
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struct module *module = NULL;
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struct mutex *cb_mutex;
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struct netlink_sock *nlk;
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int err = 0;
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sock->state = SS_UNCONNECTED;
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if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
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return -ESOCKTNOSUPPORT;
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if (protocol < 0 || protocol >= MAX_LINKS)
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return -EPROTONOSUPPORT;
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netlink_lock_table();
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#ifdef CONFIG_KMOD
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if (!nl_table[protocol].registered) {
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netlink_unlock_table();
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request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
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netlink_lock_table();
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}
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#endif
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if (nl_table[protocol].registered &&
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try_module_get(nl_table[protocol].module))
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module = nl_table[protocol].module;
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cb_mutex = nl_table[protocol].cb_mutex;
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netlink_unlock_table();
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err = __netlink_create(net, sock, cb_mutex, protocol);
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if (err < 0)
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goto out_module;
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nlk = nlk_sk(sock->sk);
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nlk->module = module;
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out:
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return err;
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out_module:
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module_put(module);
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goto out;
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}
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static int netlink_release(struct socket *sock)
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{
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struct sock *sk = sock->sk;
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struct netlink_sock *nlk;
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if (!sk)
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return 0;
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netlink_remove(sk);
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sock_orphan(sk);
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nlk = nlk_sk(sk);
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/*
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* OK. Socket is unlinked, any packets that arrive now
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* will be purged.
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*/
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sock->sk = NULL;
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wake_up_interruptible_all(&nlk->wait);
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skb_queue_purge(&sk->sk_write_queue);
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if (nlk->pid && !nlk->subscriptions) {
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struct netlink_notify n = {
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.net = sock_net(sk),
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.protocol = sk->sk_protocol,
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.pid = nlk->pid,
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};
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atomic_notifier_call_chain(&netlink_chain,
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NETLINK_URELEASE, &n);
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}
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module_put(nlk->module);
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netlink_table_grab();
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if (netlink_is_kernel(sk)) {
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BUG_ON(nl_table[sk->sk_protocol].registered == 0);
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if (--nl_table[sk->sk_protocol].registered == 0) {
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kfree(nl_table[sk->sk_protocol].listeners);
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nl_table[sk->sk_protocol].module = NULL;
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nl_table[sk->sk_protocol].registered = 0;
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}
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} else if (nlk->subscriptions)
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netlink_update_listeners(sk);
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netlink_table_ungrab();
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kfree(nlk->groups);
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nlk->groups = NULL;
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sock_put(sk);
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return 0;
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}
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static int netlink_autobind(struct socket *sock)
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{
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struct sock *sk = sock->sk;
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struct net *net = sock_net(sk);
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struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
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struct hlist_head *head;
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struct sock *osk;
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struct hlist_node *node;
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s32 pid = current->tgid;
|
|
int err;
|
|
static s32 rover = -4097;
|
|
|
|
retry:
|
|
cond_resched();
|
|
netlink_table_grab();
|
|
head = nl_pid_hashfn(hash, pid);
|
|
sk_for_each(osk, node, head) {
|
|
if (!net_eq(sock_net(osk), net))
|
|
continue;
|
|
if (nlk_sk(osk)->pid == pid) {
|
|
/* Bind collision, search negative pid values. */
|
|
pid = rover--;
|
|
if (rover > -4097)
|
|
rover = -4097;
|
|
netlink_table_ungrab();
|
|
goto retry;
|
|
}
|
|
}
|
|
netlink_table_ungrab();
|
|
|
|
err = netlink_insert(sk, net, pid);
|
|
if (err == -EADDRINUSE)
|
|
goto retry;
|
|
|
|
/* If 2 threads race to autobind, that is fine. */
|
|
if (err == -EBUSY)
|
|
err = 0;
|
|
|
|
return err;
|
|
}
|
|
|
|
static inline int netlink_capable(struct socket *sock, unsigned int flag)
|
|
{
|
|
return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) ||
|
|
capable(CAP_NET_ADMIN);
|
|
}
|
|
|
|
static void
|
|
netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions)
|
|
{
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
|
|
if (nlk->subscriptions && !subscriptions)
|
|
__sk_del_bind_node(sk);
|
|
else if (!nlk->subscriptions && subscriptions)
|
|
sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
|
|
nlk->subscriptions = subscriptions;
|
|
}
|
|
|
|
static int netlink_realloc_groups(struct sock *sk)
|
|
{
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
unsigned int groups;
|
|
unsigned long *new_groups;
|
|
int err = 0;
|
|
|
|
netlink_table_grab();
|
|
|
|
groups = nl_table[sk->sk_protocol].groups;
|
|
if (!nl_table[sk->sk_protocol].registered) {
|
|
err = -ENOENT;
|
|
goto out_unlock;
|
|
}
|
|
|
|
if (nlk->ngroups >= groups)
|
|
goto out_unlock;
|
|
|
|
new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC);
|
|
if (new_groups == NULL) {
|
|
err = -ENOMEM;
|
|
goto out_unlock;
|
|
}
|
|
memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0,
|
|
NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups));
|
|
|
|
nlk->groups = new_groups;
|
|
nlk->ngroups = groups;
|
|
out_unlock:
|
|
netlink_table_ungrab();
|
|
return err;
|
|
}
|
|
|
|
static int netlink_bind(struct socket *sock, struct sockaddr *addr,
|
|
int addr_len)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct net *net = sock_net(sk);
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
|
|
int err;
|
|
|
|
if (nladdr->nl_family != AF_NETLINK)
|
|
return -EINVAL;
|
|
|
|
/* Only superuser is allowed to listen multicasts */
|
|
if (nladdr->nl_groups) {
|
|
if (!netlink_capable(sock, NL_NONROOT_RECV))
|
|
return -EPERM;
|
|
err = netlink_realloc_groups(sk);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
if (nlk->pid) {
|
|
if (nladdr->nl_pid != nlk->pid)
|
|
return -EINVAL;
|
|
} else {
|
|
err = nladdr->nl_pid ?
|
|
netlink_insert(sk, net, nladdr->nl_pid) :
|
|
netlink_autobind(sock);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
|
|
return 0;
|
|
|
|
netlink_table_grab();
|
|
netlink_update_subscriptions(sk, nlk->subscriptions +
|
|
hweight32(nladdr->nl_groups) -
|
|
hweight32(nlk->groups[0]));
|
|
nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups;
|
|
netlink_update_listeners(sk);
|
|
netlink_table_ungrab();
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int netlink_connect(struct socket *sock, struct sockaddr *addr,
|
|
int alen, int flags)
|
|
{
|
|
int err = 0;
|
|
struct sock *sk = sock->sk;
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
|
|
|
|
if (addr->sa_family == AF_UNSPEC) {
|
|
sk->sk_state = NETLINK_UNCONNECTED;
|
|
nlk->dst_pid = 0;
|
|
nlk->dst_group = 0;
|
|
return 0;
|
|
}
|
|
if (addr->sa_family != AF_NETLINK)
|
|
return -EINVAL;
|
|
|
|
/* Only superuser is allowed to send multicasts */
|
|
if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND))
|
|
return -EPERM;
|
|
|
|
if (!nlk->pid)
|
|
err = netlink_autobind(sock);
|
|
|
|
if (err == 0) {
|
|
sk->sk_state = NETLINK_CONNECTED;
|
|
nlk->dst_pid = nladdr->nl_pid;
|
|
nlk->dst_group = ffs(nladdr->nl_groups);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int netlink_getname(struct socket *sock, struct sockaddr *addr,
|
|
int *addr_len, int peer)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
|
|
|
|
nladdr->nl_family = AF_NETLINK;
|
|
nladdr->nl_pad = 0;
|
|
*addr_len = sizeof(*nladdr);
|
|
|
|
if (peer) {
|
|
nladdr->nl_pid = nlk->dst_pid;
|
|
nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
|
|
} else {
|
|
nladdr->nl_pid = nlk->pid;
|
|
nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void netlink_overrun(struct sock *sk)
|
|
{
|
|
if (!test_and_set_bit(0, &nlk_sk(sk)->state)) {
|
|
sk->sk_err = ENOBUFS;
|
|
sk->sk_error_report(sk);
|
|
}
|
|
}
|
|
|
|
static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid)
|
|
{
|
|
struct sock *sock;
|
|
struct netlink_sock *nlk;
|
|
|
|
sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, pid);
|
|
if (!sock)
|
|
return ERR_PTR(-ECONNREFUSED);
|
|
|
|
/* Don't bother queuing skb if kernel socket has no input function */
|
|
nlk = nlk_sk(sock);
|
|
if (sock->sk_state == NETLINK_CONNECTED &&
|
|
nlk->dst_pid != nlk_sk(ssk)->pid) {
|
|
sock_put(sock);
|
|
return ERR_PTR(-ECONNREFUSED);
|
|
}
|
|
return sock;
|
|
}
|
|
|
|
struct sock *netlink_getsockbyfilp(struct file *filp)
|
|
{
|
|
struct inode *inode = filp->f_path.dentry->d_inode;
|
|
struct sock *sock;
|
|
|
|
if (!S_ISSOCK(inode->i_mode))
|
|
return ERR_PTR(-ENOTSOCK);
|
|
|
|
sock = SOCKET_I(inode)->sk;
|
|
if (sock->sk_family != AF_NETLINK)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
sock_hold(sock);
|
|
return sock;
|
|
}
|
|
|
|
/*
|
|
* Attach a skb to a netlink socket.
|
|
* The caller must hold a reference to the destination socket. On error, the
|
|
* reference is dropped. The skb is not send to the destination, just all
|
|
* all error checks are performed and memory in the queue is reserved.
|
|
* Return values:
|
|
* < 0: error. skb freed, reference to sock dropped.
|
|
* 0: continue
|
|
* 1: repeat lookup - reference dropped while waiting for socket memory.
|
|
*/
|
|
int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock,
|
|
long *timeo, struct sock *ssk)
|
|
{
|
|
struct netlink_sock *nlk;
|
|
|
|
nlk = nlk_sk(sk);
|
|
|
|
if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
|
|
test_bit(0, &nlk->state)) {
|
|
DECLARE_WAITQUEUE(wait, current);
|
|
if (!*timeo) {
|
|
if (!ssk || netlink_is_kernel(ssk))
|
|
netlink_overrun(sk);
|
|
sock_put(sk);
|
|
kfree_skb(skb);
|
|
return -EAGAIN;
|
|
}
|
|
|
|
__set_current_state(TASK_INTERRUPTIBLE);
|
|
add_wait_queue(&nlk->wait, &wait);
|
|
|
|
if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
|
|
test_bit(0, &nlk->state)) &&
|
|
!sock_flag(sk, SOCK_DEAD))
|
|
*timeo = schedule_timeout(*timeo);
|
|
|
|
__set_current_state(TASK_RUNNING);
|
|
remove_wait_queue(&nlk->wait, &wait);
|
|
sock_put(sk);
|
|
|
|
if (signal_pending(current)) {
|
|
kfree_skb(skb);
|
|
return sock_intr_errno(*timeo);
|
|
}
|
|
return 1;
|
|
}
|
|
skb_set_owner_r(skb, sk);
|
|
return 0;
|
|
}
|
|
|
|
int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
int len = skb->len;
|
|
|
|
skb_queue_tail(&sk->sk_receive_queue, skb);
|
|
sk->sk_data_ready(sk, len);
|
|
sock_put(sk);
|
|
return len;
|
|
}
|
|
|
|
void netlink_detachskb(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
kfree_skb(skb);
|
|
sock_put(sk);
|
|
}
|
|
|
|
static inline struct sk_buff *netlink_trim(struct sk_buff *skb,
|
|
gfp_t allocation)
|
|
{
|
|
int delta;
|
|
|
|
skb_orphan(skb);
|
|
|
|
delta = skb->end - skb->tail;
|
|
if (delta * 2 < skb->truesize)
|
|
return skb;
|
|
|
|
if (skb_shared(skb)) {
|
|
struct sk_buff *nskb = skb_clone(skb, allocation);
|
|
if (!nskb)
|
|
return skb;
|
|
kfree_skb(skb);
|
|
skb = nskb;
|
|
}
|
|
|
|
if (!pskb_expand_head(skb, 0, -delta, allocation))
|
|
skb->truesize -= delta;
|
|
|
|
return skb;
|
|
}
|
|
|
|
static inline void netlink_rcv_wake(struct sock *sk)
|
|
{
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
|
|
if (skb_queue_empty(&sk->sk_receive_queue))
|
|
clear_bit(0, &nlk->state);
|
|
if (!test_bit(0, &nlk->state))
|
|
wake_up_interruptible(&nlk->wait);
|
|
}
|
|
|
|
static inline int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
int ret;
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
|
|
ret = -ECONNREFUSED;
|
|
if (nlk->netlink_rcv != NULL) {
|
|
ret = skb->len;
|
|
skb_set_owner_r(skb, sk);
|
|
nlk->netlink_rcv(skb);
|
|
}
|
|
kfree_skb(skb);
|
|
sock_put(sk);
|
|
return ret;
|
|
}
|
|
|
|
int netlink_unicast(struct sock *ssk, struct sk_buff *skb,
|
|
u32 pid, int nonblock)
|
|
{
|
|
struct sock *sk;
|
|
int err;
|
|
long timeo;
|
|
|
|
skb = netlink_trim(skb, gfp_any());
|
|
|
|
timeo = sock_sndtimeo(ssk, nonblock);
|
|
retry:
|
|
sk = netlink_getsockbypid(ssk, pid);
|
|
if (IS_ERR(sk)) {
|
|
kfree_skb(skb);
|
|
return PTR_ERR(sk);
|
|
}
|
|
if (netlink_is_kernel(sk))
|
|
return netlink_unicast_kernel(sk, skb);
|
|
|
|
if (sk_filter(sk, skb)) {
|
|
int err = skb->len;
|
|
kfree_skb(skb);
|
|
sock_put(sk);
|
|
return err;
|
|
}
|
|
|
|
err = netlink_attachskb(sk, skb, nonblock, &timeo, ssk);
|
|
if (err == 1)
|
|
goto retry;
|
|
if (err)
|
|
return err;
|
|
|
|
return netlink_sendskb(sk, skb);
|
|
}
|
|
EXPORT_SYMBOL(netlink_unicast);
|
|
|
|
int netlink_has_listeners(struct sock *sk, unsigned int group)
|
|
{
|
|
int res = 0;
|
|
unsigned long *listeners;
|
|
|
|
BUG_ON(!netlink_is_kernel(sk));
|
|
|
|
rcu_read_lock();
|
|
listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners);
|
|
|
|
if (group - 1 < nl_table[sk->sk_protocol].groups)
|
|
res = test_bit(group - 1, listeners);
|
|
|
|
rcu_read_unlock();
|
|
|
|
return res;
|
|
}
|
|
EXPORT_SYMBOL_GPL(netlink_has_listeners);
|
|
|
|
static inline int netlink_broadcast_deliver(struct sock *sk,
|
|
struct sk_buff *skb)
|
|
{
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
|
|
if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
|
|
!test_bit(0, &nlk->state)) {
|
|
skb_set_owner_r(skb, sk);
|
|
skb_queue_tail(&sk->sk_receive_queue, skb);
|
|
sk->sk_data_ready(sk, skb->len);
|
|
return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
struct netlink_broadcast_data {
|
|
struct sock *exclude_sk;
|
|
struct net *net;
|
|
u32 pid;
|
|
u32 group;
|
|
int failure;
|
|
int congested;
|
|
int delivered;
|
|
gfp_t allocation;
|
|
struct sk_buff *skb, *skb2;
|
|
};
|
|
|
|
static inline int do_one_broadcast(struct sock *sk,
|
|
struct netlink_broadcast_data *p)
|
|
{
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
int val;
|
|
|
|
if (p->exclude_sk == sk)
|
|
goto out;
|
|
|
|
if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
|
|
!test_bit(p->group - 1, nlk->groups))
|
|
goto out;
|
|
|
|
if (!net_eq(sock_net(sk), p->net))
|
|
goto out;
|
|
|
|
if (p->failure) {
|
|
netlink_overrun(sk);
|
|
goto out;
|
|
}
|
|
|
|
sock_hold(sk);
|
|
if (p->skb2 == NULL) {
|
|
if (skb_shared(p->skb)) {
|
|
p->skb2 = skb_clone(p->skb, p->allocation);
|
|
} else {
|
|
p->skb2 = skb_get(p->skb);
|
|
/*
|
|
* skb ownership may have been set when
|
|
* delivered to a previous socket.
|
|
*/
|
|
skb_orphan(p->skb2);
|
|
}
|
|
}
|
|
if (p->skb2 == NULL) {
|
|
netlink_overrun(sk);
|
|
/* Clone failed. Notify ALL listeners. */
|
|
p->failure = 1;
|
|
} else if (sk_filter(sk, p->skb2)) {
|
|
kfree_skb(p->skb2);
|
|
p->skb2 = NULL;
|
|
} else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) {
|
|
netlink_overrun(sk);
|
|
} else {
|
|
p->congested |= val;
|
|
p->delivered = 1;
|
|
p->skb2 = NULL;
|
|
}
|
|
sock_put(sk);
|
|
|
|
out:
|
|
return 0;
|
|
}
|
|
|
|
int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
|
|
u32 group, gfp_t allocation)
|
|
{
|
|
struct net *net = sock_net(ssk);
|
|
struct netlink_broadcast_data info;
|
|
struct hlist_node *node;
|
|
struct sock *sk;
|
|
|
|
skb = netlink_trim(skb, allocation);
|
|
|
|
info.exclude_sk = ssk;
|
|
info.net = net;
|
|
info.pid = pid;
|
|
info.group = group;
|
|
info.failure = 0;
|
|
info.congested = 0;
|
|
info.delivered = 0;
|
|
info.allocation = allocation;
|
|
info.skb = skb;
|
|
info.skb2 = NULL;
|
|
|
|
/* While we sleep in clone, do not allow to change socket list */
|
|
|
|
netlink_lock_table();
|
|
|
|
sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
|
|
do_one_broadcast(sk, &info);
|
|
|
|
kfree_skb(skb);
|
|
|
|
netlink_unlock_table();
|
|
|
|
if (info.skb2)
|
|
kfree_skb(info.skb2);
|
|
|
|
if (info.delivered) {
|
|
if (info.congested && (allocation & __GFP_WAIT))
|
|
yield();
|
|
return 0;
|
|
}
|
|
if (info.failure)
|
|
return -ENOBUFS;
|
|
return -ESRCH;
|
|
}
|
|
EXPORT_SYMBOL(netlink_broadcast);
|
|
|
|
struct netlink_set_err_data {
|
|
struct sock *exclude_sk;
|
|
u32 pid;
|
|
u32 group;
|
|
int code;
|
|
};
|
|
|
|
static inline int do_one_set_err(struct sock *sk,
|
|
struct netlink_set_err_data *p)
|
|
{
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
|
|
if (sk == p->exclude_sk)
|
|
goto out;
|
|
|
|
if (sock_net(sk) != sock_net(p->exclude_sk))
|
|
goto out;
|
|
|
|
if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
|
|
!test_bit(p->group - 1, nlk->groups))
|
|
goto out;
|
|
|
|
sk->sk_err = p->code;
|
|
sk->sk_error_report(sk);
|
|
out:
|
|
return 0;
|
|
}
|
|
|
|
void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code)
|
|
{
|
|
struct netlink_set_err_data info;
|
|
struct hlist_node *node;
|
|
struct sock *sk;
|
|
|
|
info.exclude_sk = ssk;
|
|
info.pid = pid;
|
|
info.group = group;
|
|
info.code = code;
|
|
|
|
read_lock(&nl_table_lock);
|
|
|
|
sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
|
|
do_one_set_err(sk, &info);
|
|
|
|
read_unlock(&nl_table_lock);
|
|
}
|
|
|
|
/* must be called with netlink table grabbed */
|
|
static void netlink_update_socket_mc(struct netlink_sock *nlk,
|
|
unsigned int group,
|
|
int is_new)
|
|
{
|
|
int old, new = !!is_new, subscriptions;
|
|
|
|
old = test_bit(group - 1, nlk->groups);
|
|
subscriptions = nlk->subscriptions - old + new;
|
|
if (new)
|
|
__set_bit(group - 1, nlk->groups);
|
|
else
|
|
__clear_bit(group - 1, nlk->groups);
|
|
netlink_update_subscriptions(&nlk->sk, subscriptions);
|
|
netlink_update_listeners(&nlk->sk);
|
|
}
|
|
|
|
static int netlink_setsockopt(struct socket *sock, int level, int optname,
|
|
char __user *optval, int optlen)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
unsigned int val = 0;
|
|
int err;
|
|
|
|
if (level != SOL_NETLINK)
|
|
return -ENOPROTOOPT;
|
|
|
|
if (optlen >= sizeof(int) &&
|
|
get_user(val, (unsigned int __user *)optval))
|
|
return -EFAULT;
|
|
|
|
switch (optname) {
|
|
case NETLINK_PKTINFO:
|
|
if (val)
|
|
nlk->flags |= NETLINK_RECV_PKTINFO;
|
|
else
|
|
nlk->flags &= ~NETLINK_RECV_PKTINFO;
|
|
err = 0;
|
|
break;
|
|
case NETLINK_ADD_MEMBERSHIP:
|
|
case NETLINK_DROP_MEMBERSHIP: {
|
|
if (!netlink_capable(sock, NL_NONROOT_RECV))
|
|
return -EPERM;
|
|
err = netlink_realloc_groups(sk);
|
|
if (err)
|
|
return err;
|
|
if (!val || val - 1 >= nlk->ngroups)
|
|
return -EINVAL;
|
|
netlink_table_grab();
|
|
netlink_update_socket_mc(nlk, val,
|
|
optname == NETLINK_ADD_MEMBERSHIP);
|
|
netlink_table_ungrab();
|
|
err = 0;
|
|
break;
|
|
}
|
|
default:
|
|
err = -ENOPROTOOPT;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int netlink_getsockopt(struct socket *sock, int level, int optname,
|
|
char __user *optval, int __user *optlen)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
int len, val, err;
|
|
|
|
if (level != SOL_NETLINK)
|
|
return -ENOPROTOOPT;
|
|
|
|
if (get_user(len, optlen))
|
|
return -EFAULT;
|
|
if (len < 0)
|
|
return -EINVAL;
|
|
|
|
switch (optname) {
|
|
case NETLINK_PKTINFO:
|
|
if (len < sizeof(int))
|
|
return -EINVAL;
|
|
len = sizeof(int);
|
|
val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0;
|
|
if (put_user(len, optlen) ||
|
|
put_user(val, optval))
|
|
return -EFAULT;
|
|
err = 0;
|
|
break;
|
|
default:
|
|
err = -ENOPROTOOPT;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
|
|
{
|
|
struct nl_pktinfo info;
|
|
|
|
info.group = NETLINK_CB(skb).dst_group;
|
|
put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info);
|
|
}
|
|
|
|
static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
|
|
struct msghdr *msg, size_t len)
|
|
{
|
|
struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
|
|
struct sock *sk = sock->sk;
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
struct sockaddr_nl *addr = msg->msg_name;
|
|
u32 dst_pid;
|
|
u32 dst_group;
|
|
struct sk_buff *skb;
|
|
int err;
|
|
struct scm_cookie scm;
|
|
|
|
if (msg->msg_flags&MSG_OOB)
|
|
return -EOPNOTSUPP;
|
|
|
|
if (NULL == siocb->scm)
|
|
siocb->scm = &scm;
|
|
err = scm_send(sock, msg, siocb->scm);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
if (msg->msg_namelen) {
|
|
if (addr->nl_family != AF_NETLINK)
|
|
return -EINVAL;
|
|
dst_pid = addr->nl_pid;
|
|
dst_group = ffs(addr->nl_groups);
|
|
if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND))
|
|
return -EPERM;
|
|
} else {
|
|
dst_pid = nlk->dst_pid;
|
|
dst_group = nlk->dst_group;
|
|
}
|
|
|
|
if (!nlk->pid) {
|
|
err = netlink_autobind(sock);
|
|
if (err)
|
|
goto out;
|
|
}
|
|
|
|
err = -EMSGSIZE;
|
|
if (len > sk->sk_sndbuf - 32)
|
|
goto out;
|
|
err = -ENOBUFS;
|
|
skb = alloc_skb(len, GFP_KERNEL);
|
|
if (skb == NULL)
|
|
goto out;
|
|
|
|
NETLINK_CB(skb).pid = nlk->pid;
|
|
NETLINK_CB(skb).dst_group = dst_group;
|
|
NETLINK_CB(skb).loginuid = audit_get_loginuid(current);
|
|
NETLINK_CB(skb).sessionid = audit_get_sessionid(current);
|
|
security_task_getsecid(current, &(NETLINK_CB(skb).sid));
|
|
memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
|
|
|
|
/* What can I do? Netlink is asynchronous, so that
|
|
we will have to save current capabilities to
|
|
check them, when this message will be delivered
|
|
to corresponding kernel module. --ANK (980802)
|
|
*/
|
|
|
|
err = -EFAULT;
|
|
if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
|
|
kfree_skb(skb);
|
|
goto out;
|
|
}
|
|
|
|
err = security_netlink_send(sk, skb);
|
|
if (err) {
|
|
kfree_skb(skb);
|
|
goto out;
|
|
}
|
|
|
|
if (dst_group) {
|
|
atomic_inc(&skb->users);
|
|
netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL);
|
|
}
|
|
err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT);
|
|
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
|
|
struct msghdr *msg, size_t len,
|
|
int flags)
|
|
{
|
|
struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
|
|
struct scm_cookie scm;
|
|
struct sock *sk = sock->sk;
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
int noblock = flags&MSG_DONTWAIT;
|
|
size_t copied;
|
|
struct sk_buff *skb;
|
|
int err;
|
|
|
|
if (flags&MSG_OOB)
|
|
return -EOPNOTSUPP;
|
|
|
|
copied = 0;
|
|
|
|
skb = skb_recv_datagram(sk, flags, noblock, &err);
|
|
if (skb == NULL)
|
|
goto out;
|
|
|
|
msg->msg_namelen = 0;
|
|
|
|
copied = skb->len;
|
|
if (len < copied) {
|
|
msg->msg_flags |= MSG_TRUNC;
|
|
copied = len;
|
|
}
|
|
|
|
skb_reset_transport_header(skb);
|
|
err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
|
|
|
|
if (msg->msg_name) {
|
|
struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name;
|
|
addr->nl_family = AF_NETLINK;
|
|
addr->nl_pad = 0;
|
|
addr->nl_pid = NETLINK_CB(skb).pid;
|
|
addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group);
|
|
msg->msg_namelen = sizeof(*addr);
|
|
}
|
|
|
|
if (nlk->flags & NETLINK_RECV_PKTINFO)
|
|
netlink_cmsg_recv_pktinfo(msg, skb);
|
|
|
|
if (NULL == siocb->scm) {
|
|
memset(&scm, 0, sizeof(scm));
|
|
siocb->scm = &scm;
|
|
}
|
|
siocb->scm->creds = *NETLINK_CREDS(skb);
|
|
if (flags & MSG_TRUNC)
|
|
copied = skb->len;
|
|
skb_free_datagram(sk, skb);
|
|
|
|
if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2)
|
|
netlink_dump(sk);
|
|
|
|
scm_recv(sock, msg, siocb->scm, flags);
|
|
out:
|
|
netlink_rcv_wake(sk);
|
|
return err ? : copied;
|
|
}
|
|
|
|
static void netlink_data_ready(struct sock *sk, int len)
|
|
{
|
|
BUG();
|
|
}
|
|
|
|
/*
|
|
* We export these functions to other modules. They provide a
|
|
* complete set of kernel non-blocking support for message
|
|
* queueing.
|
|
*/
|
|
|
|
struct sock *
|
|
netlink_kernel_create(struct net *net, int unit, unsigned int groups,
|
|
void (*input)(struct sk_buff *skb),
|
|
struct mutex *cb_mutex, struct module *module)
|
|
{
|
|
struct socket *sock;
|
|
struct sock *sk;
|
|
struct netlink_sock *nlk;
|
|
unsigned long *listeners = NULL;
|
|
|
|
BUG_ON(!nl_table);
|
|
|
|
if (unit < 0 || unit >= MAX_LINKS)
|
|
return NULL;
|
|
|
|
if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
|
|
return NULL;
|
|
|
|
/*
|
|
* We have to just have a reference on the net from sk, but don't
|
|
* get_net it. Besides, we cannot get and then put the net here.
|
|
* So we create one inside init_net and the move it to net.
|
|
*/
|
|
|
|
if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0)
|
|
goto out_sock_release_nosk;
|
|
|
|
sk = sock->sk;
|
|
sk_change_net(sk, net);
|
|
|
|
if (groups < 32)
|
|
groups = 32;
|
|
|
|
listeners = kzalloc(NLGRPSZ(groups), GFP_KERNEL);
|
|
if (!listeners)
|
|
goto out_sock_release;
|
|
|
|
sk->sk_data_ready = netlink_data_ready;
|
|
if (input)
|
|
nlk_sk(sk)->netlink_rcv = input;
|
|
|
|
if (netlink_insert(sk, net, 0))
|
|
goto out_sock_release;
|
|
|
|
nlk = nlk_sk(sk);
|
|
nlk->flags |= NETLINK_KERNEL_SOCKET;
|
|
|
|
netlink_table_grab();
|
|
if (!nl_table[unit].registered) {
|
|
nl_table[unit].groups = groups;
|
|
nl_table[unit].listeners = listeners;
|
|
nl_table[unit].cb_mutex = cb_mutex;
|
|
nl_table[unit].module = module;
|
|
nl_table[unit].registered = 1;
|
|
} else {
|
|
kfree(listeners);
|
|
nl_table[unit].registered++;
|
|
}
|
|
netlink_table_ungrab();
|
|
return sk;
|
|
|
|
out_sock_release:
|
|
kfree(listeners);
|
|
netlink_kernel_release(sk);
|
|
return NULL;
|
|
|
|
out_sock_release_nosk:
|
|
sock_release(sock);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(netlink_kernel_create);
|
|
|
|
|
|
void
|
|
netlink_kernel_release(struct sock *sk)
|
|
{
|
|
sk_release_kernel(sk);
|
|
}
|
|
EXPORT_SYMBOL(netlink_kernel_release);
|
|
|
|
|
|
/**
|
|
* netlink_change_ngroups - change number of multicast groups
|
|
*
|
|
* This changes the number of multicast groups that are available
|
|
* on a certain netlink family. Note that it is not possible to
|
|
* change the number of groups to below 32. Also note that it does
|
|
* not implicitly call netlink_clear_multicast_users() when the
|
|
* number of groups is reduced.
|
|
*
|
|
* @sk: The kernel netlink socket, as returned by netlink_kernel_create().
|
|
* @groups: The new number of groups.
|
|
*/
|
|
int netlink_change_ngroups(struct sock *sk, unsigned int groups)
|
|
{
|
|
unsigned long *listeners, *old = NULL;
|
|
struct netlink_table *tbl = &nl_table[sk->sk_protocol];
|
|
int err = 0;
|
|
|
|
if (groups < 32)
|
|
groups = 32;
|
|
|
|
netlink_table_grab();
|
|
if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) {
|
|
listeners = kzalloc(NLGRPSZ(groups), GFP_ATOMIC);
|
|
if (!listeners) {
|
|
err = -ENOMEM;
|
|
goto out_ungrab;
|
|
}
|
|
old = tbl->listeners;
|
|
memcpy(listeners, old, NLGRPSZ(tbl->groups));
|
|
rcu_assign_pointer(tbl->listeners, listeners);
|
|
}
|
|
tbl->groups = groups;
|
|
|
|
out_ungrab:
|
|
netlink_table_ungrab();
|
|
synchronize_rcu();
|
|
kfree(old);
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(netlink_change_ngroups);
|
|
|
|
/**
|
|
* netlink_clear_multicast_users - kick off multicast listeners
|
|
*
|
|
* This function removes all listeners from the given group.
|
|
* @ksk: The kernel netlink socket, as returned by
|
|
* netlink_kernel_create().
|
|
* @group: The multicast group to clear.
|
|
*/
|
|
void netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
|
|
{
|
|
struct sock *sk;
|
|
struct hlist_node *node;
|
|
struct netlink_table *tbl = &nl_table[ksk->sk_protocol];
|
|
|
|
netlink_table_grab();
|
|
|
|
sk_for_each_bound(sk, node, &tbl->mc_list)
|
|
netlink_update_socket_mc(nlk_sk(sk), group, 0);
|
|
|
|
netlink_table_ungrab();
|
|
}
|
|
EXPORT_SYMBOL(netlink_clear_multicast_users);
|
|
|
|
void netlink_set_nonroot(int protocol, unsigned int flags)
|
|
{
|
|
if ((unsigned int)protocol < MAX_LINKS)
|
|
nl_table[protocol].nl_nonroot = flags;
|
|
}
|
|
EXPORT_SYMBOL(netlink_set_nonroot);
|
|
|
|
static void netlink_destroy_callback(struct netlink_callback *cb)
|
|
{
|
|
if (cb->skb)
|
|
kfree_skb(cb->skb);
|
|
kfree(cb);
|
|
}
|
|
|
|
/*
|
|
* It looks a bit ugly.
|
|
* It would be better to create kernel thread.
|
|
*/
|
|
|
|
static int netlink_dump(struct sock *sk)
|
|
{
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
struct netlink_callback *cb;
|
|
struct sk_buff *skb;
|
|
struct nlmsghdr *nlh;
|
|
int len, err = -ENOBUFS;
|
|
|
|
skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL);
|
|
if (!skb)
|
|
goto errout;
|
|
|
|
mutex_lock(nlk->cb_mutex);
|
|
|
|
cb = nlk->cb;
|
|
if (cb == NULL) {
|
|
err = -EINVAL;
|
|
goto errout_skb;
|
|
}
|
|
|
|
len = cb->dump(skb, cb);
|
|
|
|
if (len > 0) {
|
|
mutex_unlock(nlk->cb_mutex);
|
|
|
|
if (sk_filter(sk, skb))
|
|
kfree_skb(skb);
|
|
else {
|
|
skb_queue_tail(&sk->sk_receive_queue, skb);
|
|
sk->sk_data_ready(sk, skb->len);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI);
|
|
if (!nlh)
|
|
goto errout_skb;
|
|
|
|
memcpy(nlmsg_data(nlh), &len, sizeof(len));
|
|
|
|
if (sk_filter(sk, skb))
|
|
kfree_skb(skb);
|
|
else {
|
|
skb_queue_tail(&sk->sk_receive_queue, skb);
|
|
sk->sk_data_ready(sk, skb->len);
|
|
}
|
|
|
|
if (cb->done)
|
|
cb->done(cb);
|
|
nlk->cb = NULL;
|
|
mutex_unlock(nlk->cb_mutex);
|
|
|
|
netlink_destroy_callback(cb);
|
|
return 0;
|
|
|
|
errout_skb:
|
|
mutex_unlock(nlk->cb_mutex);
|
|
kfree_skb(skb);
|
|
errout:
|
|
return err;
|
|
}
|
|
|
|
int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
|
|
struct nlmsghdr *nlh,
|
|
int (*dump)(struct sk_buff *skb,
|
|
struct netlink_callback *),
|
|
int (*done)(struct netlink_callback *))
|
|
{
|
|
struct netlink_callback *cb;
|
|
struct sock *sk;
|
|
struct netlink_sock *nlk;
|
|
|
|
cb = kzalloc(sizeof(*cb), GFP_KERNEL);
|
|
if (cb == NULL)
|
|
return -ENOBUFS;
|
|
|
|
cb->dump = dump;
|
|
cb->done = done;
|
|
cb->nlh = nlh;
|
|
atomic_inc(&skb->users);
|
|
cb->skb = skb;
|
|
|
|
sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).pid);
|
|
if (sk == NULL) {
|
|
netlink_destroy_callback(cb);
|
|
return -ECONNREFUSED;
|
|
}
|
|
nlk = nlk_sk(sk);
|
|
/* A dump is in progress... */
|
|
mutex_lock(nlk->cb_mutex);
|
|
if (nlk->cb) {
|
|
mutex_unlock(nlk->cb_mutex);
|
|
netlink_destroy_callback(cb);
|
|
sock_put(sk);
|
|
return -EBUSY;
|
|
}
|
|
nlk->cb = cb;
|
|
mutex_unlock(nlk->cb_mutex);
|
|
|
|
netlink_dump(sk);
|
|
sock_put(sk);
|
|
|
|
/* We successfully started a dump, by returning -EINTR we
|
|
* signal not to send ACK even if it was requested.
|
|
*/
|
|
return -EINTR;
|
|
}
|
|
EXPORT_SYMBOL(netlink_dump_start);
|
|
|
|
void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
|
|
{
|
|
struct sk_buff *skb;
|
|
struct nlmsghdr *rep;
|
|
struct nlmsgerr *errmsg;
|
|
size_t payload = sizeof(*errmsg);
|
|
|
|
/* error messages get the original request appened */
|
|
if (err)
|
|
payload += nlmsg_len(nlh);
|
|
|
|
skb = nlmsg_new(payload, GFP_KERNEL);
|
|
if (!skb) {
|
|
struct sock *sk;
|
|
|
|
sk = netlink_lookup(sock_net(in_skb->sk),
|
|
in_skb->sk->sk_protocol,
|
|
NETLINK_CB(in_skb).pid);
|
|
if (sk) {
|
|
sk->sk_err = ENOBUFS;
|
|
sk->sk_error_report(sk);
|
|
sock_put(sk);
|
|
}
|
|
return;
|
|
}
|
|
|
|
rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
|
|
NLMSG_ERROR, sizeof(struct nlmsgerr), 0);
|
|
errmsg = nlmsg_data(rep);
|
|
errmsg->error = err;
|
|
memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh));
|
|
netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
|
|
}
|
|
EXPORT_SYMBOL(netlink_ack);
|
|
|
|
int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
|
|
struct nlmsghdr *))
|
|
{
|
|
struct nlmsghdr *nlh;
|
|
int err;
|
|
|
|
while (skb->len >= nlmsg_total_size(0)) {
|
|
int msglen;
|
|
|
|
nlh = nlmsg_hdr(skb);
|
|
err = 0;
|
|
|
|
if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
|
|
return 0;
|
|
|
|
/* Only requests are handled by the kernel */
|
|
if (!(nlh->nlmsg_flags & NLM_F_REQUEST))
|
|
goto ack;
|
|
|
|
/* Skip control messages */
|
|
if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
|
|
goto ack;
|
|
|
|
err = cb(skb, nlh);
|
|
if (err == -EINTR)
|
|
goto skip;
|
|
|
|
ack:
|
|
if (nlh->nlmsg_flags & NLM_F_ACK || err)
|
|
netlink_ack(skb, nlh, err);
|
|
|
|
skip:
|
|
msglen = NLMSG_ALIGN(nlh->nlmsg_len);
|
|
if (msglen > skb->len)
|
|
msglen = skb->len;
|
|
skb_pull(skb, msglen);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(netlink_rcv_skb);
|
|
|
|
/**
|
|
* nlmsg_notify - send a notification netlink message
|
|
* @sk: netlink socket to use
|
|
* @skb: notification message
|
|
* @pid: destination netlink pid for reports or 0
|
|
* @group: destination multicast group or 0
|
|
* @report: 1 to report back, 0 to disable
|
|
* @flags: allocation flags
|
|
*/
|
|
int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid,
|
|
unsigned int group, int report, gfp_t flags)
|
|
{
|
|
int err = 0;
|
|
|
|
if (group) {
|
|
int exclude_pid = 0;
|
|
|
|
if (report) {
|
|
atomic_inc(&skb->users);
|
|
exclude_pid = pid;
|
|
}
|
|
|
|
/* errors reported via destination sk->sk_err */
|
|
nlmsg_multicast(sk, skb, exclude_pid, group, flags);
|
|
}
|
|
|
|
if (report)
|
|
err = nlmsg_unicast(sk, skb, pid);
|
|
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(nlmsg_notify);
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
struct nl_seq_iter {
|
|
struct seq_net_private p;
|
|
int link;
|
|
int hash_idx;
|
|
};
|
|
|
|
static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos)
|
|
{
|
|
struct nl_seq_iter *iter = seq->private;
|
|
int i, j;
|
|
struct sock *s;
|
|
struct hlist_node *node;
|
|
loff_t off = 0;
|
|
|
|
for (i = 0; i < MAX_LINKS; i++) {
|
|
struct nl_pid_hash *hash = &nl_table[i].hash;
|
|
|
|
for (j = 0; j <= hash->mask; j++) {
|
|
sk_for_each(s, node, &hash->table[j]) {
|
|
if (sock_net(s) != seq_file_net(seq))
|
|
continue;
|
|
if (off == pos) {
|
|
iter->link = i;
|
|
iter->hash_idx = j;
|
|
return s;
|
|
}
|
|
++off;
|
|
}
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static void *netlink_seq_start(struct seq_file *seq, loff_t *pos)
|
|
__acquires(nl_table_lock)
|
|
{
|
|
read_lock(&nl_table_lock);
|
|
return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN;
|
|
}
|
|
|
|
static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
|
|
{
|
|
struct sock *s;
|
|
struct nl_seq_iter *iter;
|
|
int i, j;
|
|
|
|
++*pos;
|
|
|
|
if (v == SEQ_START_TOKEN)
|
|
return netlink_seq_socket_idx(seq, 0);
|
|
|
|
iter = seq->private;
|
|
s = v;
|
|
do {
|
|
s = sk_next(s);
|
|
} while (s && sock_net(s) != seq_file_net(seq));
|
|
if (s)
|
|
return s;
|
|
|
|
i = iter->link;
|
|
j = iter->hash_idx + 1;
|
|
|
|
do {
|
|
struct nl_pid_hash *hash = &nl_table[i].hash;
|
|
|
|
for (; j <= hash->mask; j++) {
|
|
s = sk_head(&hash->table[j]);
|
|
while (s && sock_net(s) != seq_file_net(seq))
|
|
s = sk_next(s);
|
|
if (s) {
|
|
iter->link = i;
|
|
iter->hash_idx = j;
|
|
return s;
|
|
}
|
|
}
|
|
|
|
j = 0;
|
|
} while (++i < MAX_LINKS);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void netlink_seq_stop(struct seq_file *seq, void *v)
|
|
__releases(nl_table_lock)
|
|
{
|
|
read_unlock(&nl_table_lock);
|
|
}
|
|
|
|
|
|
static int netlink_seq_show(struct seq_file *seq, void *v)
|
|
{
|
|
if (v == SEQ_START_TOKEN)
|
|
seq_puts(seq,
|
|
"sk Eth Pid Groups "
|
|
"Rmem Wmem Dump Locks\n");
|
|
else {
|
|
struct sock *s = v;
|
|
struct netlink_sock *nlk = nlk_sk(s);
|
|
|
|
seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %d\n",
|
|
s,
|
|
s->sk_protocol,
|
|
nlk->pid,
|
|
nlk->groups ? (u32)nlk->groups[0] : 0,
|
|
atomic_read(&s->sk_rmem_alloc),
|
|
atomic_read(&s->sk_wmem_alloc),
|
|
nlk->cb,
|
|
atomic_read(&s->sk_refcnt)
|
|
);
|
|
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations netlink_seq_ops = {
|
|
.start = netlink_seq_start,
|
|
.next = netlink_seq_next,
|
|
.stop = netlink_seq_stop,
|
|
.show = netlink_seq_show,
|
|
};
|
|
|
|
|
|
static int netlink_seq_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open_net(inode, file, &netlink_seq_ops,
|
|
sizeof(struct nl_seq_iter));
|
|
}
|
|
|
|
static const struct file_operations netlink_seq_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = netlink_seq_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release_net,
|
|
};
|
|
|
|
#endif
|
|
|
|
int netlink_register_notifier(struct notifier_block *nb)
|
|
{
|
|
return atomic_notifier_chain_register(&netlink_chain, nb);
|
|
}
|
|
EXPORT_SYMBOL(netlink_register_notifier);
|
|
|
|
int netlink_unregister_notifier(struct notifier_block *nb)
|
|
{
|
|
return atomic_notifier_chain_unregister(&netlink_chain, nb);
|
|
}
|
|
EXPORT_SYMBOL(netlink_unregister_notifier);
|
|
|
|
static const struct proto_ops netlink_ops = {
|
|
.family = PF_NETLINK,
|
|
.owner = THIS_MODULE,
|
|
.release = netlink_release,
|
|
.bind = netlink_bind,
|
|
.connect = netlink_connect,
|
|
.socketpair = sock_no_socketpair,
|
|
.accept = sock_no_accept,
|
|
.getname = netlink_getname,
|
|
.poll = datagram_poll,
|
|
.ioctl = sock_no_ioctl,
|
|
.listen = sock_no_listen,
|
|
.shutdown = sock_no_shutdown,
|
|
.setsockopt = netlink_setsockopt,
|
|
.getsockopt = netlink_getsockopt,
|
|
.sendmsg = netlink_sendmsg,
|
|
.recvmsg = netlink_recvmsg,
|
|
.mmap = sock_no_mmap,
|
|
.sendpage = sock_no_sendpage,
|
|
};
|
|
|
|
static struct net_proto_family netlink_family_ops = {
|
|
.family = PF_NETLINK,
|
|
.create = netlink_create,
|
|
.owner = THIS_MODULE, /* for consistency 8) */
|
|
};
|
|
|
|
static int __net_init netlink_net_init(struct net *net)
|
|
{
|
|
#ifdef CONFIG_PROC_FS
|
|
if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops))
|
|
return -ENOMEM;
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
static void __net_exit netlink_net_exit(struct net *net)
|
|
{
|
|
#ifdef CONFIG_PROC_FS
|
|
proc_net_remove(net, "netlink");
|
|
#endif
|
|
}
|
|
|
|
static struct pernet_operations __net_initdata netlink_net_ops = {
|
|
.init = netlink_net_init,
|
|
.exit = netlink_net_exit,
|
|
};
|
|
|
|
static int __init netlink_proto_init(void)
|
|
{
|
|
struct sk_buff *dummy_skb;
|
|
int i;
|
|
unsigned long limit;
|
|
unsigned int order;
|
|
int err = proto_register(&netlink_proto, 0);
|
|
|
|
if (err != 0)
|
|
goto out;
|
|
|
|
BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb));
|
|
|
|
nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);
|
|
if (!nl_table)
|
|
goto panic;
|
|
|
|
if (num_physpages >= (128 * 1024))
|
|
limit = num_physpages >> (21 - PAGE_SHIFT);
|
|
else
|
|
limit = num_physpages >> (23 - PAGE_SHIFT);
|
|
|
|
order = get_bitmask_order(limit) - 1 + PAGE_SHIFT;
|
|
limit = (1UL << order) / sizeof(struct hlist_head);
|
|
order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1;
|
|
|
|
for (i = 0; i < MAX_LINKS; i++) {
|
|
struct nl_pid_hash *hash = &nl_table[i].hash;
|
|
|
|
hash->table = nl_pid_hash_zalloc(1 * sizeof(*hash->table));
|
|
if (!hash->table) {
|
|
while (i-- > 0)
|
|
nl_pid_hash_free(nl_table[i].hash.table,
|
|
1 * sizeof(*hash->table));
|
|
kfree(nl_table);
|
|
goto panic;
|
|
}
|
|
hash->max_shift = order;
|
|
hash->shift = 0;
|
|
hash->mask = 0;
|
|
hash->rehash_time = jiffies;
|
|
}
|
|
|
|
sock_register(&netlink_family_ops);
|
|
register_pernet_subsys(&netlink_net_ops);
|
|
/* The netlink device handler may be needed early. */
|
|
rtnetlink_init();
|
|
out:
|
|
return err;
|
|
panic:
|
|
panic("netlink_init: Cannot allocate nl_table\n");
|
|
}
|
|
|
|
core_initcall(netlink_proto_init);
|