Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 1454 insertions, 0 deletions

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
new file mode 100644
index 000000000000..1d5905c90cd4
--- /dev/null
+++ b/net/netlink/af_netlink.c
@@ -0,0 +1,1454 @@
+/*
+ * NETLINK      Kernel-user communication protocol.
+ *
+ * 		Authors:	Alan Cox <alan@redhat.com>
+ * 				Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ * 
+ * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith
+ *                               added netlink_proto_exit
+ * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br>
+ * 				 use nlk_sk, as sk->protinfo is on a diet 8)
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/major.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/stat.h>
+#include <linux/socket.h>
+#include <linux/un.h>
+#include <linux/fcntl.h>
+#include <linux/termios.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <asm/uaccess.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/rtnetlink.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/smp_lock.h>
+#include <linux/notifier.h>
+#include <linux/security.h>
+#include <linux/jhash.h>
+#include <linux/jiffies.h>
+#include <linux/random.h>
+#include <linux/bitops.h>
+#include <linux/mm.h>
+#include <linux/types.h>
+#include <net/sock.h>
+#include <net/scm.h>
+
+#define Nprintk(a...)
+
+struct netlink_sock {
+	/* struct sock has to be the first member of netlink_sock */
+	struct sock		sk;
+	u32			pid;
+	unsigned int		groups;
+	u32			dst_pid;
+	unsigned int		dst_groups;
+	unsigned long		state;
+	wait_queue_head_t	wait;
+	struct netlink_callback	*cb;
+	spinlock_t		cb_lock;
+	void			(*data_ready)(struct sock *sk, int bytes);
+};
+
+static inline struct netlink_sock *nlk_sk(struct sock *sk)
+{
+	return (struct netlink_sock *)sk;
+}
+
+struct nl_pid_hash {
+	struct hlist_head *table;
+	unsigned long rehash_time;
+
+	unsigned int mask;
+	unsigned int shift;
+
+	unsigned int entries;
+	unsigned int max_shift;
+
+	u32 rnd;
+};
+
+struct netlink_table {
+	struct nl_pid_hash hash;
+	struct hlist_head mc_list;
+	unsigned int nl_nonroot;
+};
+
+static struct netlink_table *nl_table;
+
+static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
+
+static int netlink_dump(struct sock *sk);
+static void netlink_destroy_callback(struct netlink_callback *cb);
+
+static DEFINE_RWLOCK(nl_table_lock);
+static atomic_t nl_table_users = ATOMIC_INIT(0);
+
+static struct notifier_block *netlink_chain;
+
+static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid)
+{
+	return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask];
+}
+
+static void netlink_sock_destruct(struct sock *sk)
+{
+	skb_queue_purge(&sk->sk_receive_queue);
+
+	if (!sock_flag(sk, SOCK_DEAD)) {
+		printk("Freeing alive netlink socket %p\n", sk);
+		return;
+	}
+	BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc));
+	BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
+	BUG_TRAP(!nlk_sk(sk)->cb);
+}
+
+/* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on SMP.
+ * Look, when several writers sleep and reader wakes them up, all but one
+ * immediately hit write lock and grab all the cpus. Exclusive sleep solves
+ * this, _but_ remember, it adds useless work on UP machines.
+ */
+
+static void netlink_table_grab(void)
+{
+	write_lock_bh(&nl_table_lock);
+
+	if (atomic_read(&nl_table_users)) {
+		DECLARE_WAITQUEUE(wait, current);
+
+		add_wait_queue_exclusive(&nl_table_wait, &wait);
+		for(;;) {
+			set_current_state(TASK_UNINTERRUPTIBLE);
+			if (atomic_read(&nl_table_users) == 0)
+				break;
+			write_unlock_bh(&nl_table_lock);
+			schedule();
+			write_lock_bh(&nl_table_lock);
+		}
+
+		__set_current_state(TASK_RUNNING);
+		remove_wait_queue(&nl_table_wait, &wait);
+	}
+}
+
+static __inline__ void netlink_table_ungrab(void)
+{
+	write_unlock_bh(&nl_table_lock);
+	wake_up(&nl_table_wait);
+}
+
+static __inline__ void
+netlink_lock_table(void)
+{
+	/* read_lock() synchronizes us to netlink_table_grab */
+
+	read_lock(&nl_table_lock);
+	atomic_inc(&nl_table_users);
+	read_unlock(&nl_table_lock);
+}
+
+static __inline__ void
+netlink_unlock_table(void)
+{
+	if (atomic_dec_and_test(&nl_table_users))
+		wake_up(&nl_table_wait);
+}
+
+static __inline__ struct sock *netlink_lookup(int protocol, u32 pid)
+{
+	struct nl_pid_hash *hash = &nl_table[protocol].hash;
+	struct hlist_head *head;
+	struct sock *sk;
+	struct hlist_node *node;
+
+	read_lock(&nl_table_lock);
+	head = nl_pid_hashfn(hash, pid);
+	sk_for_each(sk, node, head) {
+		if (nlk_sk(sk)->pid == pid) {
+			sock_hold(sk);
+			goto found;
+		}
+	}
+	sk = NULL;
+found:
+	read_unlock(&nl_table_lock);
+	return sk;
+}
+
+static inline struct hlist_head *nl_pid_hash_alloc(size_t size)
+{
+	if (size <= PAGE_SIZE)
+		return kmalloc(size, GFP_ATOMIC);
+	else
+		return (struct hlist_head *)
+			__get_free_pages(GFP_ATOMIC, get_order(size));
+}
+
+static inline void nl_pid_hash_free(struct hlist_head *table, size_t size)
+{
+	if (size <= PAGE_SIZE)
+		kfree(table);
+	else
+		free_pages((unsigned long)table, get_order(size));
+}
+
+static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow)
+{
+	unsigned int omask, mask, shift;
+	size_t osize, size;
+	struct hlist_head *otable, *table;
+	int i;
+
+	omask = mask = hash->mask;
+	osize = size = (mask + 1) * sizeof(*table);
+	shift = hash->shift;
+
+	if (grow) {
+		if (++shift > hash->max_shift)
+			return 0;
+		mask = mask * 2 + 1;
+		size *= 2;
+	}
+
+	table = nl_pid_hash_alloc(size);
+	if (!table)
+		return 0;
+
+	memset(table, 0, size);
+	otable = hash->table;
+	hash->table = table;
+	hash->mask = mask;
+	hash->shift = shift;
+	get_random_bytes(&hash->rnd, sizeof(hash->rnd));
+
+	for (i = 0; i <= omask; i++) {
+		struct sock *sk;
+		struct hlist_node *node, *tmp;
+
+		sk_for_each_safe(sk, node, tmp, &otable[i])
+			__sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid));
+	}
+
+	nl_pid_hash_free(otable, osize);
+	hash->rehash_time = jiffies + 10 * 60 * HZ;
+	return 1;
+}
+
+static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len)
+{
+	int avg = hash->entries >> hash->shift;
+
+	if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1))
+		return 1;
+
+	if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) {
+		nl_pid_hash_rehash(hash, 0);
+		return 1;
+	}
+
+	return 0;
+}
+
+static struct proto_ops netlink_ops;
+
+static int netlink_insert(struct sock *sk, u32 pid)
+{
+	struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
+	struct hlist_head *head;
+	int err = -EADDRINUSE;
+	struct sock *osk;
+	struct hlist_node *node;
+	int len;
+
+	netlink_table_grab();
+	head = nl_pid_hashfn(hash, pid);
+	len = 0;
+	sk_for_each(osk, node, head) {
+		if (nlk_sk(osk)->pid == pid)
+			break;
+		len++;
+	}
+	if (node)
+		goto err;
+
+	err = -EBUSY;
+	if (nlk_sk(sk)->pid)
+		goto err;
+
+	err = -ENOMEM;
+	if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX))
+		goto err;
+
+	if (len && nl_pid_hash_dilute(hash, len))
+		head = nl_pid_hashfn(hash, pid);
+	hash->entries++;
+	nlk_sk(sk)->pid = pid;
+	sk_add_node(sk, head);
+	err = 0;
+
+err:
+	netlink_table_ungrab();
+	return err;
+}
+
+static void netlink_remove(struct sock *sk)
+{
+	netlink_table_grab();
+	nl_table[sk->sk_protocol].hash.entries--;
+	sk_del_node_init(sk);
+	if (nlk_sk(sk)->groups)
+		__sk_del_bind_node(sk);
+	netlink_table_ungrab();
+}
+
+static struct proto netlink_proto = {
+	.name	  = "NETLINK",
+	.owner	  = THIS_MODULE,
+	.obj_size = sizeof(struct netlink_sock),
+};
+
+static int netlink_create(struct socket *sock, int protocol)
+{
+	struct sock *sk;
+	struct netlink_sock *nlk;
+
+	sock->state = SS_UNCONNECTED;
+
+	if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
+		return -ESOCKTNOSUPPORT;
+
+	if (protocol<0 || protocol >= MAX_LINKS)
+		return -EPROTONOSUPPORT;
+
+	sock->ops = &netlink_ops;
+
+	sk = sk_alloc(PF_NETLINK, GFP_KERNEL, &netlink_proto, 1);
+	if (!sk)
+		return -ENOMEM;
+
+	sock_init_data(sock, sk);
+
+	nlk = nlk_sk(sk);
+
+	spin_lock_init(&nlk->cb_lock);
+	init_waitqueue_head(&nlk->wait);
+	sk->sk_destruct = netlink_sock_destruct;
+
+	sk->sk_protocol = protocol;
+	return 0;
+}
+
+static int netlink_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+	struct netlink_sock *nlk;
+
+	if (!sk)
+		return 0;
+
+	netlink_remove(sk);
+	nlk = nlk_sk(sk);
+
+	spin_lock(&nlk->cb_lock);
+	if (nlk->cb) {
+		nlk->cb->done(nlk->cb);
+		netlink_destroy_callback(nlk->cb);
+		nlk->cb = NULL;
+		__sock_put(sk);
+	}
+	spin_unlock(&nlk->cb_lock);
+
+	/* OK. Socket is unlinked, and, therefore,
+	   no new packets will arrive */
+
+	sock_orphan(sk);
+	sock->sk = NULL;
+	wake_up_interruptible_all(&nlk->wait);
+
+	skb_queue_purge(&sk->sk_write_queue);
+
+	if (nlk->pid && !nlk->groups) {
+		struct netlink_notify n = {
+						.protocol = sk->sk_protocol,
+						.pid = nlk->pid,
+					  };
+		notifier_call_chain(&netlink_chain, NETLINK_URELEASE, &n);
+	}	
+	
+	sock_put(sk);
+	return 0;
+}
+
+static int netlink_autobind(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+	struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
+	struct hlist_head *head;
+	struct sock *osk;
+	struct hlist_node *node;
+	s32 pid = current->pid;
+	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 (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, pid);
+	if (err == -EADDRINUSE)
+		goto retry;
+	return 0;
+}
+
+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 int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
+{
+	struct sock *sk = sock->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 && !netlink_capable(sock, NL_NONROOT_RECV))
+		return -EPERM;
+
+	if (nlk->pid) {
+		if (nladdr->nl_pid != nlk->pid)
+			return -EINVAL;
+	} else {
+		err = nladdr->nl_pid ?
+			netlink_insert(sk, nladdr->nl_pid) :
+			netlink_autobind(sock);
+		if (err)
+			return err;
+	}
+
+	if (!nladdr->nl_groups && !nlk->groups)
+		return 0;
+
+	netlink_table_grab();
+	if (nlk->groups && !nladdr->nl_groups)
+		__sk_del_bind_node(sk);
+	else if (!nlk->groups && nladdr->nl_groups)
+		sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
+	nlk->groups = nladdr->nl_groups;
+	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_groups = 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_groups = 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 = nlk->dst_groups;
+	} else {
+		nladdr->nl_pid = nlk->pid;
+		nladdr->nl_groups = nlk->groups;
+	}
+	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)
+{
+	int protocol = ssk->sk_protocol;
+	struct sock *sock;
+	struct netlink_sock *nlk;
+
+	sock = netlink_lookup(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 ((nlk->pid == 0 && !nlk->data_ready) ||
+	    (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_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 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 (!nlk->pid)
+				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 protocol)
+{
+	struct netlink_sock *nlk;
+	int len = skb->len;
+
+	nlk = nlk_sk(sk);
+
+	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, int 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;
+}
+
+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);
+	}
+	err = netlink_attachskb(sk, skb, nonblock, timeo);
+	if (err == 1)
+		goto retry;
+	if (err)
+		return err;
+
+	return netlink_sendskb(sk, skb, ssk->sk_protocol);
+}
+
+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;
+	u32 pid;
+	u32 group;
+	int failure;
+	int congested;
+	int delivered;
+	int 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 || !(nlk->groups & p->group))
+		goto out;
+
+	if (p->failure) {
+		netlink_overrun(sk);
+		goto out;
+	}
+
+	sock_hold(sk);
+	if (p->skb2 == NULL) {
+		if (atomic_read(&p->skb->users) != 1) {
+			p->skb2 = skb_clone(p->skb, p->allocation);
+		} else {
+			p->skb2 = p->skb;
+			atomic_inc(&p->skb->users);
+		}
+	}
+	if (p->skb2 == NULL) {
+		netlink_overrun(sk);
+		/* Clone failed. Notify ALL listeners. */
+		p->failure = 1;
+	} 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, int allocation)
+{
+	struct netlink_broadcast_data info;
+	struct hlist_node *node;
+	struct sock *sk;
+
+	skb = netlink_trim(skb, allocation);
+
+	info.exclude_sk = ssk;
+	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);
+
+	netlink_unlock_table();
+
+	if (info.skb2)
+		kfree_skb(info.skb2);
+	kfree_skb(skb);
+
+	if (info.delivered) {
+		if (info.congested && (allocation & __GFP_WAIT))
+			yield();
+		return 0;
+	}
+	if (info.failure)
+		return -ENOBUFS;
+	return -ESRCH;
+}
+
+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 (nlk->pid == p->pid || !(nlk->groups & p->group))
+		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);
+}
+
+static inline void netlink_rcv_wake(struct sock *sk)
+{
+	struct netlink_sock *nlk = nlk_sk(sk);
+
+	if (!skb_queue_len(&sk->sk_receive_queue))
+		clear_bit(0, &nlk->state);
+	if (!test_bit(0, &nlk->state))
+		wake_up_interruptible(&nlk->wait);
+}
+
+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_groups;
+	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_groups = addr->nl_groups;
+		if (dst_groups && !netlink_capable(sock, NL_NONROOT_SEND))
+			return -EPERM;
+	} else {
+		dst_pid = nlk->dst_pid;
+		dst_groups = nlk->dst_groups;
+	}
+
+	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).groups	= nlk->groups;
+	NETLINK_CB(skb).dst_pid = dst_pid;
+	NETLINK_CB(skb).dst_groups = dst_groups;
+	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_groups) {
+		atomic_inc(&skb->users);
+		netlink_broadcast(sk, skb, dst_pid, dst_groups, 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->h.raw = skb->data;
+	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_CB(skb).dst_groups;
+		msg->msg_namelen = sizeof(*addr);
+	}
+
+	if (NULL == siocb->scm) {
+		memset(&scm, 0, sizeof(scm));
+		siocb->scm = &scm;
+	}
+	siocb->scm->creds = *NETLINK_CREDS(skb);
+	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)
+{
+	struct netlink_sock *nlk = nlk_sk(sk);
+
+	if (nlk->data_ready)
+		nlk->data_ready(sk, len);
+	netlink_rcv_wake(sk);
+}
+
+/*
+ *	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(int unit, void (*input)(struct sock *sk, int len))
+{
+	struct socket *sock;
+	struct sock *sk;
+
+	if (!nl_table)
+		return NULL;
+
+	if (unit<0 || unit>=MAX_LINKS)
+		return NULL;
+
+	if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
+		return NULL;
+
+	if (netlink_create(sock, unit) < 0) {
+		sock_release(sock);
+		return NULL;
+	}
+	sk = sock->sk;
+	sk->sk_data_ready = netlink_data_ready;
+	if (input)
+		nlk_sk(sk)->data_ready = input;
+
+	if (netlink_insert(sk, 0)) {
+		sock_release(sock);
+		return NULL;
+	}
+	return sk;
+}
+
+void netlink_set_nonroot(int protocol, unsigned int flags)
+{ 
+	if ((unsigned int)protocol < MAX_LINKS) 
+		nl_table[protocol].nl_nonroot = flags;
+} 
+
+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;
+	
+	skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL);
+	if (!skb)
+		return -ENOBUFS;
+
+	spin_lock(&nlk->cb_lock);
+
+	cb = nlk->cb;
+	if (cb == NULL) {
+		spin_unlock(&nlk->cb_lock);
+		kfree_skb(skb);
+		return -EINVAL;
+	}
+
+	len = cb->dump(skb, cb);
+
+	if (len > 0) {
+		spin_unlock(&nlk->cb_lock);
+		skb_queue_tail(&sk->sk_receive_queue, skb);
+		sk->sk_data_ready(sk, len);
+		return 0;
+	}
+
+	nlh = __nlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, NLMSG_DONE, sizeof(int));
+	nlh->nlmsg_flags |= NLM_F_MULTI;
+	memcpy(NLMSG_DATA(nlh), &len, sizeof(len));
+	skb_queue_tail(&sk->sk_receive_queue, skb);
+	sk->sk_data_ready(sk, skb->len);
+
+	cb->done(cb);
+	nlk->cb = NULL;
+	spin_unlock(&nlk->cb_lock);
+
+	netlink_destroy_callback(cb);
+	__sock_put(sk);
+	return 0;
+}
+
+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 = kmalloc(sizeof(*cb), GFP_KERNEL);
+	if (cb == NULL)
+		return -ENOBUFS;
+
+	memset(cb, 0, sizeof(*cb));
+	cb->dump = dump;
+	cb->done = done;
+	cb->nlh = nlh;
+	atomic_inc(&skb->users);
+	cb->skb = skb;
+
+	sk = netlink_lookup(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... */
+	spin_lock(&nlk->cb_lock);
+	if (nlk->cb) {
+		spin_unlock(&nlk->cb_lock);
+		netlink_destroy_callback(cb);
+		sock_put(sk);
+		return -EBUSY;
+	}
+	nlk->cb = cb;
+	sock_hold(sk);
+	spin_unlock(&nlk->cb_lock);
+
+	netlink_dump(sk);
+	sock_put(sk);
+	return 0;
+}
+
+void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
+{
+	struct sk_buff *skb;
+	struct nlmsghdr *rep;
+	struct nlmsgerr *errmsg;
+	int size;
+
+	if (err == 0)
+		size = NLMSG_SPACE(sizeof(struct nlmsgerr));
+	else
+		size = NLMSG_SPACE(4 + NLMSG_ALIGN(nlh->nlmsg_len));
+
+	skb = alloc_skb(size, GFP_KERNEL);
+	if (!skb) {
+		struct sock *sk;
+
+		sk = netlink_lookup(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));
+	errmsg = NLMSG_DATA(rep);
+	errmsg->error = err;
+	memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(struct nlmsghdr));
+	netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
+}
+
+
+#ifdef CONFIG_PROC_FS
+struct nl_seq_iter {
+	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 (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)
+{
+	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);
+		
+	s = sk_next(v);
+	if (s)
+		return s;
+
+	iter = seq->private;
+	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]);
+			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)
+{
+	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,
+			   atomic_read(&s->sk_rmem_alloc),
+			   atomic_read(&s->sk_wmem_alloc),
+			   nlk->cb,
+			   atomic_read(&s->sk_refcnt)
+			);
+
+	}
+	return 0;
+}
+
+static 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)
+{
+	struct seq_file *seq;
+	struct nl_seq_iter *iter;
+	int err;
+
+	iter = kmalloc(sizeof(*iter), GFP_KERNEL);
+	if (!iter)
+		return -ENOMEM;
+
+	err = seq_open(file, &netlink_seq_ops);
+	if (err) {
+		kfree(iter);
+		return err;
+	}
+
+	memset(iter, 0, sizeof(*iter));
+	seq = file->private_data;
+	seq->private = iter;
+	return 0;
+}
+
+static struct file_operations netlink_seq_fops = {
+	.owner		= THIS_MODULE,
+	.open		= netlink_seq_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release_private,
+};
+
+#endif
+
+int netlink_register_notifier(struct notifier_block *nb)
+{
+	return notifier_chain_register(&netlink_chain, nb);
+}
+
+int netlink_unregister_notifier(struct notifier_block *nb)
+{
+	return notifier_chain_unregister(&netlink_chain, nb);
+}
+                
+static 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 =	sock_no_setsockopt,
+	.getsockopt =	sock_no_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) */
+};
+
+extern void netlink_skb_parms_too_large(void);
+
+static int __init netlink_proto_init(void)
+{
+	struct sk_buff *dummy_skb;
+	int i;
+	unsigned long max;
+	unsigned int order;
+	int err = proto_register(&netlink_proto, 0);
+
+	if (err != 0)
+		goto out;
+
+	if (sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb))
+		netlink_skb_parms_too_large();
+
+	nl_table = kmalloc(sizeof(*nl_table) * MAX_LINKS, GFP_KERNEL);
+	if (!nl_table) {
+enomem:
+		printk(KERN_CRIT "netlink_init: Cannot allocate nl_table\n");
+		return -ENOMEM;
+	}
+
+	memset(nl_table, 0, sizeof(*nl_table) * MAX_LINKS);
+
+	if (num_physpages >= (128 * 1024))
+		max = num_physpages >> (21 - PAGE_SHIFT);
+	else
+		max = num_physpages >> (23 - PAGE_SHIFT);
+
+	order = get_bitmask_order(max) - 1 + PAGE_SHIFT;
+	max = (1UL << order) / sizeof(struct hlist_head);
+	order = get_bitmask_order(max > UINT_MAX ? UINT_MAX : max) - 1;
+
+	for (i = 0; i < MAX_LINKS; i++) {
+		struct nl_pid_hash *hash = &nl_table[i].hash;
+
+		hash->table = nl_pid_hash_alloc(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 enomem;
+		}
+		memset(hash->table, 0, 1 * sizeof(*hash->table));
+		hash->max_shift = order;
+		hash->shift = 0;
+		hash->mask = 0;
+		hash->rehash_time = jiffies;
+	}
+
+	sock_register(&netlink_family_ops);
+#ifdef CONFIG_PROC_FS
+	proc_net_fops_create("netlink", 0, &netlink_seq_fops);
+#endif
+	/* The netlink device handler may be needed early. */ 
+	rtnetlink_init();
+out:
+	return err;
+}
+
+static void __exit netlink_proto_exit(void)
+{
+	sock_unregister(PF_NETLINK);
+	proc_net_remove("netlink");
+	kfree(nl_table);
+	nl_table = NULL;
+	proto_unregister(&netlink_proto);
+}
+
+core_initcall(netlink_proto_init);
+module_exit(netlink_proto_exit);
+
+MODULE_LICENSE("GPL");
+
+MODULE_ALIAS_NETPROTO(PF_NETLINK);
+
+EXPORT_SYMBOL(netlink_ack);
+EXPORT_SYMBOL(netlink_broadcast);
+EXPORT_SYMBOL(netlink_dump_start);
+EXPORT_SYMBOL(netlink_kernel_create);
+EXPORT_SYMBOL(netlink_register_notifier);
+EXPORT_SYMBOL(netlink_set_err);
+EXPORT_SYMBOL(netlink_set_nonroot);
+EXPORT_SYMBOL(netlink_unicast);
+EXPORT_SYMBOL(netlink_unregister_notifier);
+