patch-2.1.68 linux/net/netlink/af_netlink.c

• Lines: 1026
• Date: Sun Nov 30 14:00:40 1997
• Orig file: v2.1.67/linux/net/netlink/af_netlink.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.67/linux/net/netlink/af_netlink.c linux/net/netlink/af_netlink.c
@@ -0,0 +1,1025 @@
+/*
+ * NETLINK      Kernel-user communication protocol.
+ *
+ * 		Authors:	Alan Cox <alan@cymru.net>
+ * 				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.
+ * 
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+
+#include <linux/kernel.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/socket.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/fs.h>
+#include <linux/malloc.h>
+#include <asm/uaccess.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/netlink.h>
+#include <linux/proc_fs.h>
+#include <net/sock.h>
+#include <net/scm.h>
+
+#define Nprintk(a...)
+
+#if defined(CONFIG_NETLINK_DEV) || defined(CONFIG_NETLINK_DEV_MODULE)
+#define NL_EMULATE_DEV
+#endif
+
+static struct sock *nl_table[MAX_LINKS];
+static atomic_t nl_table_lock[MAX_LINKS];
+static struct wait_queue *nl_table_wait;
+
+#ifdef NL_EMULATE_DEV
+static struct socket *netlink_kernel[MAX_LINKS];
+#endif
+
+static int netlink_dump(struct sock *sk);
+static void netlink_destroy_callback(struct netlink_callback *cb);
+
+extern __inline__ void
+netlink_wait_on_table(int protocol)
+{
+	while (atomic_read(&nl_table_lock[protocol]))
+		sleep_on(&nl_table_wait);
+}
+
+extern __inline__ void
+netlink_lock_table(int protocol)
+{
+	atomic_inc(&nl_table_lock[protocol]);
+}
+
+extern __inline__ void
+netlink_unlock_table(int protocol, int wakeup)
+{
+#if 0
+	/* F...g gcc does not eat it! */
+
+	if (atomic_dec_and_test(&nl_table_lock[protocol]) && wakeup)
+		wake_up(&nl_table_wait);
+#else
+	atomic_dec(&nl_table_lock[protocol]);
+	if (atomic_read(&nl_table_lock[protocol]) && wakeup)
+		wake_up(&nl_table_wait);
+#endif
+}
+
+static __inline__ void netlink_lock(struct sock *sk)
+{
+	atomic_inc(&sk->protinfo.af_netlink.locks);
+}
+
+static __inline__ void netlink_unlock(struct sock *sk)
+{
+	atomic_dec(&sk->protinfo.af_netlink.locks);
+}
+
+static __inline__ int netlink_locked(struct sock *sk)
+{
+	return atomic_read(&sk->protinfo.af_netlink.locks);
+}
+
+static __inline__ struct sock *netlink_lookup(int protocol, pid_t pid)
+{
+	struct sock *sk;
+
+	for (sk=nl_table[protocol]; sk; sk=sk->next) {
+		if (sk->protinfo.af_netlink.pid == pid) {
+			netlink_lock(sk);
+			return sk;
+		}
+	}
+
+	return NULL;
+}
+
+extern struct proto_ops netlink_ops;
+
+static void netlink_insert(struct sock *sk)
+{
+	cli();
+	sk->next = nl_table[sk->protocol];
+	nl_table[sk->protocol] = sk;
+	sti();
+}
+
+static void netlink_remove(struct sock *sk)
+{
+	struct sock **skp;
+	for (skp = &nl_table[sk->protocol]; *skp; skp = &((*skp)->next)) {
+		if (*skp == sk) {
+			*skp = sk->next;
+			return;
+		}
+	}
+}
+
+static int netlink_create(struct socket *sock, int protocol)
+{
+	struct sock *sk;
+
+	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(AF_NETLINK, GFP_KERNEL);
+	if (!sk)
+		return -ENOMEM;
+
+	sock_init_data(sock,sk);
+	sk->destruct = NULL;
+	
+	sk->mtu=4096;
+	sk->protocol=protocol;
+	return 0;
+}
+
+static void netlink_destroy_timer(unsigned long data)
+{
+	struct sock *sk=(struct sock *)data;
+
+	if (!netlink_locked(sk) && !atomic_read(&sk->wmem_alloc)
+	    && !atomic_read(&sk->rmem_alloc)) {
+		sk_free(sk);
+		return;
+	}
+	
+	sk->timer.expires=jiffies+10*HZ;
+	add_timer(&sk->timer);
+	printk(KERN_DEBUG "netlink sk destroy delayed\n");
+}
+
+static int netlink_release(struct socket *sock, struct socket *peer)
+{
+	struct sock *sk = sock->sk;
+
+	if (!sk)
+		return 0;
+
+	/* Wait on table before removing socket */
+	netlink_wait_on_table(sk->protocol);
+	netlink_remove(sk);
+
+	if (sk->protinfo.af_netlink.cb) {
+		netlink_unlock(sk);
+		sk->protinfo.af_netlink.cb->done(sk->protinfo.af_netlink.cb);
+		netlink_destroy_callback(sk->protinfo.af_netlink.cb);
+		sk->protinfo.af_netlink.cb = NULL;
+	}
+
+	/* OK. Socket is unlinked, and, therefore,
+	   no new packets will arrive */
+	sk->state_change(sk);
+	sk->dead = 1;
+
+	skb_queue_purge(&sk->receive_queue);
+	skb_queue_purge(&sk->write_queue);
+
+	/* IMPORTANT! It is the major unpleasant feature of this
+	   transport (and AF_UNIX datagram, when it will be repaired).
+	   
+	   Someone could wait on our sock->wait now.
+	   We cannot release socket until waiter will remove yourself
+	   from wait queue. I choose the most conservetive way of solving
+	   the problem.
+
+	   We waked up this queue above, so that we need only to wait
+	   when the readers release us.
+	 */
+
+	while (netlink_locked(sk)) {
+		current->counter = 0;
+		schedule();
+	}
+
+	if (sk->socket)	{
+		sk->socket = NULL;
+		sock->sk = NULL;
+	}
+
+	if (atomic_read(&sk->rmem_alloc) || atomic_read(&sk->wmem_alloc)) {
+		sk->timer.data=(unsigned long)sk;
+		sk->timer.expires=jiffies+HZ;
+		sk->timer.function=netlink_destroy_timer;
+		add_timer(&sk->timer);
+		printk(KERN_DEBUG "impossible 333\n");
+		return 0;
+	}
+
+	sk_free(sk);
+	return 0;
+}
+
+static int netlink_autobind(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+	struct sock *osk;
+
+	netlink_wait_on_table(sk->protocol);
+
+	sk->protinfo.af_netlink.groups = 0;
+	sk->protinfo.af_netlink.pid = current->pid;
+
+retry:
+	for (osk=nl_table[sk->protocol]; osk; osk=osk->next) {
+		if (osk->protinfo.af_netlink.pid == sk->protinfo.af_netlink.pid) {
+			/* Bind collision, search negative pid values. */
+			if (sk->protinfo.af_netlink.pid > 0)
+				sk->protinfo.af_netlink.pid = -4096;
+			sk->protinfo.af_netlink.pid--;
+			goto retry;
+		}
+	}
+
+	netlink_insert(sk);
+	return 0;
+}
+
+static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
+{
+	struct sock *sk = sock->sk;
+	struct sock *osk;
+	struct sockaddr_nl *nladdr=(struct sockaddr_nl *)addr;
+	
+	if (nladdr->nl_family != AF_NETLINK)
+		return -EINVAL;
+
+	/* Only superuser is allowed to listen multicasts */
+	if (nladdr->nl_groups && !suser())
+		return -EPERM;
+
+	if (sk->protinfo.af_netlink.pid) {
+		if (nladdr->nl_pid != sk->protinfo.af_netlink.pid)
+			return -EINVAL;
+		sk->protinfo.af_netlink.groups = nladdr->nl_groups;
+		return 0;
+	}
+
+	if (nladdr->nl_pid == 0) {
+		netlink_autobind(sock);
+		sk->protinfo.af_netlink.groups = nladdr->nl_groups;
+		return 0;
+	}
+
+	netlink_wait_on_table(sk->protocol);
+
+	for (osk=nl_table[sk->protocol]; osk; osk=osk->next) {
+		if (osk->protinfo.af_netlink.pid == nladdr->nl_pid)
+			return -EADDRINUSE;
+	}
+
+	sk->protinfo.af_netlink.pid = nladdr->nl_pid;
+	sk->protinfo.af_netlink.groups = nladdr->nl_groups;
+	netlink_insert(sk);
+	return 0;
+}
+
+static int netlink_connect(struct socket *sock, struct sockaddr *addr,
+			   int alen, int flags)
+{
+	struct sock *sk = sock->sk;
+	struct sockaddr_nl *nladdr=(struct sockaddr_nl*)addr;
+
+	if (addr->sa_family == AF_UNSPEC)
+	{
+		sk->protinfo.af_netlink.dst_pid = 0;
+		sk->protinfo.af_netlink.dst_groups = 0;
+		return 0;
+	}
+	if (addr->sa_family != AF_NETLINK)
+		return -EINVAL;
+
+	/* Only superuser is allowed to send multicasts */
+	if (!suser() && nladdr->nl_groups)
+		return -EPERM;
+
+	sk->protinfo.af_netlink.dst_pid = nladdr->nl_pid;
+	sk->protinfo.af_netlink.dst_groups = nladdr->nl_groups;
+
+	if (!sk->protinfo.af_netlink.pid)
+		netlink_autobind(sock);
+	return 0;
+}
+
+static int netlink_getname(struct socket *sock, struct sockaddr *addr, int *addr_len, int peer)
+{
+	struct sock *sk = sock->sk;
+	struct sockaddr_nl *nladdr=(struct sockaddr_nl *)addr;
+	
+	nladdr->nl_family = AF_NETLINK;
+	*addr_len = sizeof(*nladdr);
+
+	if (peer) {
+		nladdr->nl_pid = sk->protinfo.af_netlink.dst_pid;
+		nladdr->nl_groups = sk->protinfo.af_netlink.dst_groups;
+	} else {
+		nladdr->nl_pid = sk->protinfo.af_netlink.pid;
+		nladdr->nl_groups = sk->protinfo.af_netlink.groups;
+	}
+	return 0;
+}
+
+int netlink_unicast(struct sock *ssk, struct sk_buff *skb, pid_t pid, int nonblock)
+{
+	struct sock *sk;
+	int len = skb->len;
+	int protocol = ssk->protocol;
+
+retry:
+	for (sk = nl_table[protocol]; sk; sk = sk->next) {
+		if (sk->protinfo.af_netlink.pid != pid)
+				continue;
+
+		netlink_lock(sk);
+
+#ifdef NL_EMULATE_DEV
+		if (sk->protinfo.af_netlink.handler) {
+			len = sk->protinfo.af_netlink.handler(protocol, skb);
+			netlink_unlock(sk);
+			return len;
+		}
+#endif
+
+		cli();
+		if (atomic_read(&sk->rmem_alloc) > sk->rcvbuf) {
+			if (nonblock) {
+				sti();
+				netlink_unlock(sk);
+				kfree_skb(skb, 0);
+				return -EAGAIN;
+			}
+			interruptible_sleep_on(sk->sleep);
+			netlink_unlock(sk);
+			sti();
+
+			if (current->signal & ~current->blocked) {
+				kfree_skb(skb, 0);
+				return -ERESTARTSYS;
+			}
+			goto retry;
+		}
+		sti();
+Nprintk("unicast_deliver %d\n", skb->len);
+		skb_orphan(skb);
+		skb_set_owner_r(skb, sk);
+		skb_queue_tail(&sk->receive_queue, skb);
+		sk->data_ready(sk, len);
+		netlink_unlock(sk);
+		return len;
+	}
+	kfree_skb(skb, 0);
+	return -ECONNREFUSED;
+}
+
+static __inline__ int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb)
+{
+#ifdef NL_EMULATE_DEV
+	if (sk->protinfo.af_netlink.handler) {
+		sk->protinfo.af_netlink.handler(sk->protocol, skb);
+		return 0;
+	} else
+#endif
+	if (atomic_read(&sk->rmem_alloc) <= sk->rcvbuf) {
+Nprintk("broadcast_deliver %d\n", skb->len);
+                skb_orphan(skb);
+		skb_set_owner_r(skb, sk);
+		skb_queue_tail(&sk->receive_queue, skb);
+		sk->data_ready(sk, skb->len);
+		return 0;
+	}
+	return -1;
+}
+
+void netlink_broadcast(struct sock *ssk, struct sk_buff *skb, pid_t pid,
+		       unsigned group, int allocation)
+{
+	struct sock *sk;
+	struct sk_buff *skb2 = NULL;
+	int protocol = ssk->protocol;
+	int failure = 0;
+
+	/* While we sleep in clone, do not allow to change socket list */
+
+	netlink_lock_table(protocol);
+
+	for (sk = nl_table[protocol]; sk; sk = sk->next) {
+		if (ssk == sk)
+			continue;
+
+		if (sk->protinfo.af_netlink.pid == pid ||
+		    !(sk->protinfo.af_netlink.groups&group))
+			continue;
+
+		if (failure) {
+			sk->err = -ENOBUFS;
+			sk->state_change(sk);
+			continue;
+		}
+
+		netlink_lock(sk);
+		if (skb2 == NULL) {
+			if (atomic_read(&skb->users) != 1) {
+				skb2 = skb_clone(skb, allocation);
+			} else {
+				skb2 = skb;
+				atomic_inc(&skb->users);
+			}
+		}
+		if (skb2 == NULL) {
+			sk->err = -ENOBUFS;
+			sk->state_change(sk);
+			/* Clone failed. Notify ALL listeners. */
+			failure = 1;
+		} else if (netlink_broadcast_deliver(sk, skb2)) {
+			sk->err = -ENOBUFS;
+			sk->state_change(sk);
+		} else
+			skb2 = NULL;
+		netlink_unlock(sk);
+	}
+
+	netlink_unlock_table(protocol, allocation == GFP_KERNEL);
+
+	if (skb2)
+		kfree_skb(skb2, 0);
+	kfree_skb(skb, 0);
+}
+
+void netlink_set_err(struct sock *ssk, pid_t pid, unsigned group, int code)
+{
+	struct sock *sk;
+	int protocol = ssk->protocol;
+
+Nprintk("seterr");
+	for (sk = nl_table[protocol]; sk; sk = sk->next) {
+		if (ssk == sk)
+			continue;
+
+		if (sk->protinfo.af_netlink.pid == pid ||
+		    !(sk->protinfo.af_netlink.groups&group))
+			continue;
+
+		sk->err = -code;
+		sk->state_change(sk);
+	}
+}
+
+static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, int len,
+			   struct scm_cookie *scm)
+{
+	struct sock *sk = sock->sk;
+	struct sockaddr_nl *addr=msg->msg_name;
+	pid_t dst_pid;
+	unsigned dst_groups;
+	struct sk_buff *skb;
+	int err;
+
+	if (msg->msg_flags&MSG_OOB)
+		return -EOPNOTSUPP;
+
+	if (msg->msg_flags&~MSG_DONTWAIT) {
+		printk("1 %08x\n", msg->msg_flags);
+		return -EINVAL;
+	}
+
+	if (msg->msg_namelen) {
+		if (addr->nl_family != AF_NETLINK) {
+			printk("2 %08x\n", addr->nl_family);
+			return -EINVAL;
+		}
+		dst_pid = addr->nl_pid;
+		dst_groups = addr->nl_groups;
+		if (dst_groups && !suser())
+			return -EPERM;
+	} else {
+		dst_pid = sk->protinfo.af_netlink.dst_pid;
+		dst_groups = sk->protinfo.af_netlink.dst_groups;
+	}
+
+
+	if (!sk->protinfo.af_netlink.pid)
+		netlink_autobind(sock);
+
+	skb = sock_wmalloc(sk, len, 0, GFP_KERNEL);
+	if (skb==NULL)
+		return -ENOBUFS;
+
+	NETLINK_CB(skb).pid = sk->protinfo.af_netlink.pid;
+	NETLINK_CB(skb).groups = sk->protinfo.af_netlink.groups;
+	NETLINK_CB(skb).dst_pid = dst_pid;
+	NETLINK_CB(skb).dst_groups = dst_groups;
+	memcpy(NETLINK_CREDS(skb), &scm->creds, sizeof(struct ucred));
+	memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len);
+
+	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);
+	if (err < 0) {
+		printk("3\n");
+	}
+	return err;
+}
+
+static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, int len,
+			   int flags, struct scm_cookie *scm)
+{
+	struct sock *sk = sock->sk;
+	int noblock = flags&MSG_DONTWAIT;
+	int copied;
+	struct sk_buff *skb;
+	int err;
+
+	if (flags&(MSG_OOB|MSG_PEEK))
+		return -EOPNOTSUPP;
+
+	err = -sock_error(sk);
+	if (err)
+		return err;
+
+	skb = skb_recv_datagram(sk,flags,noblock,&err);
+	if (skb==NULL)
+ 		return err;
+
+	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_pid	= NETLINK_CB(skb).pid;
+		addr->nl_groups	= NETLINK_CB(skb).dst_groups;
+		msg->msg_namelen = sizeof(*addr);
+	}
+
+	scm->creds = *NETLINK_CREDS(skb);
+	skb_free_datagram(sk, skb);
+
+	if (sk->protinfo.af_netlink.cb
+	    && atomic_read(&sk->rmem_alloc) <= sk->rcvbuf/2)
+		netlink_dump(sk);
+	return err ? err : copied;
+}
+
+/*
+ *	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 (unit<0 || unit>=MAX_LINKS)
+		return NULL;
+
+	if (!(sock = sock_alloc())) 
+		return NULL;
+
+	sock->type = SOCK_RAW;
+
+	if (netlink_create(sock, unit) < 0) {
+		sock_release(sock);
+		return NULL;
+	}
+	sk = sock->sk;
+	if (input)
+		sk->data_ready = input;
+
+	netlink_insert(sk);
+	return sk;
+}
+
+static void netlink_destroy_callback(struct netlink_callback *cb)
+{
+	if (cb->skb)
+		kfree_skb(cb->skb, 0);
+	kfree(cb);
+}
+
+/*
+ * It looks a bit ugly.
+ * It would be better to create kernel thread.
+ */
+
+static int netlink_dump(struct sock *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;
+	
+	cb = sk->protinfo.af_netlink.cb;
+
+	len = cb->dump(skb, cb);
+	
+	if (len > 0) {
+		skb_queue_tail(&sk->receive_queue, skb);
+		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->receive_queue, skb);
+	sk->data_ready(sk, skb->len);
+	
+	cb->done(cb);
+	sk->protinfo.af_netlink.cb = NULL;
+	netlink_destroy_callback(cb);
+	netlink_unlock(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;
+
+	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->protocol, NETLINK_CB(skb).pid);
+	if (sk == NULL) {
+		netlink_destroy_callback(cb);
+		return -ECONNREFUSED;
+	}
+	/* A dump is in progress... */
+	if (sk->protinfo.af_netlink.cb) {
+		netlink_destroy_callback(cb);
+		netlink_unlock(sk);
+		return -EBUSY;
+	}
+	sk->protinfo.af_netlink.cb = cb;
+	netlink_dump(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 + nlh->nlmsg_len);
+
+	skb = alloc_skb(size, GFP_KERNEL);
+	if (!skb)
+		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 NL_EMULATE_DEV
+/*
+ *	Backward compatibility.
+ */	
+ 
+int netlink_attach(int unit, int (*function)(int, struct sk_buff *skb))
+{
+	struct sock *sk = netlink_kernel_create(unit, NULL);
+	if (sk == NULL)
+		return -ENOBUFS;
+	sk->protinfo.af_netlink.handler = function;
+	netlink_kernel[unit] = sk->socket;
+	return 0;
+}
+
+void netlink_detach(int unit)
+{
+	struct socket *sock = netlink_kernel[unit];
+	netlink_kernel[unit] = NULL;
+	sock_release(sock);
+}
+
+int netlink_post(int unit, struct sk_buff *skb)
+{
+	if (netlink_kernel[unit]) {
+		netlink_broadcast(netlink_kernel[unit]->sk, skb, 0, ~0, GFP_ATOMIC);
+		return 0;
+	}
+	return -EUNATCH;;
+}
+
+EXPORT_SYMBOL(netlink_attach);
+EXPORT_SYMBOL(netlink_detach);
+EXPORT_SYMBOL(netlink_post);
+
+#endif
+
+#if 0
+
+/* What a pity... It was good code, but at the moment it
+   results in unnecessary complications.
+ */
+
+/*
+ *	"High" level netlink interface. (ANK)
+ *	
+ *	Features:
+ *		- standard message format.
+ *		- pseudo-reliable delivery. Messages can be still lost, but
+ *		  user level will know that they were lost and can
+ *		  recover (f.e. gated could reread FIB and device list)
+ *		- messages are batched.
+ */
+
+/*
+ *	Try to deliver queued messages.
+ */
+
+static void nlmsg_delayed_flush(struct sock *sk)
+{
+	nlmsg_flush(sk, GFP_ATOMIC);
+}
+
+static void nlmsg_flush(struct sock *sk, int allocation)
+{
+	struct sk_buff *skb;
+	unsigned long flags;
+
+	save_flags(flags);
+	cli();
+	while ((skb=skb_dequeue(&sk->write_queue)) != NULL) {
+		if (skb->users != 1) {
+			skb_queue_head(&sk->write_queue, skb);
+			break;
+		}
+		restore_flags(flags);
+		netlink_broadcast(sk, skb, 0, NETLINK_CB(skb).dst_groups, allocation);
+		cli();
+	}
+	start_bh_atomic();
+	restore_flags(flags);
+	if (skb) {
+		if (sk->timer.function)
+			del_timer(&sk->timer)
+		sk->timer.expires = jiffies + (sk->protinfo.af_netlink.delay ? : HZ/2);
+		sk->timer.function = (void (*)(unsigned long))nlmsg_delayed_flush;
+		sk->timer.data = (unsigned long)sk;
+		add_timer(&sk->timer);
+	}
+	end_bh_atomic();
+}
+
+/*
+ *	Allocate room for new message. If it is impossible, return NULL.
+ */
+
+void *nlmsg_broadcast(struct sock *sk, struct sk_buff **skbp,
+		      unsigned long type, int len,
+		      unsigned groups, int allocation)
+{
+	struct nlmsghdr *nlh;
+	struct sk_buff *skb;
+	int	rlen;
+	unsigned long flags;
+
+	rlen = NLMSG_SPACE(len);
+
+	save_flags(flags);
+	cli();
+	skb = sk->write_queue.tail;
+	if (skb == sk->write_queue.head)
+		skb = NULL;
+	if (skb == NULL || skb_tailroom(skb) < rlen || NETLINK_CB(skb).dst_groups != groups) {
+		restore_flags(flags);
+
+		if (skb)
+			nlmsg_flush(sk, allocation);
+
+		skb = sock_wmalloc(rlen > NLMSG_GOODSIZE ? rlen : NLMSG_GOODSIZE,
+				   sk, 0, allocation);
+
+		if (skb==NULL) {
+			printk (KERN_WARNING "nlmsg at unit %d overrunned\n", sk->protocol);
+			return NULL;
+		}
+
+		NETLINK_CB(skb).dst_groups = groups;
+		cli();
+		skb_queue_tail(&sk->write_queue, skb);
+	}
+	atomic_inc(&skb->users);
+	restore_flags(flags);
+
+	nlh = (struct nlmsghdr*)skb_put(skb, rlen);
+	nlh->nlmsg_type = type;
+	nlh->nlmsg_len = NLMSG_LENGTH(len);
+	nlh->nlmsg_seq = 0;
+	nlh->nlmsg_pid = 0;
+	*skbp = skb;
+	return nlh->nlmsg_data;
+}
+
+struct sk_buff* nlmsg_alloc(unsigned long type, int len,
+			    unsigned long seq, unsigned long pid, int allocation)
+{
+	struct nlmsghdr	*nlh;
+	struct sk_buff *skb;
+	int		rlen;
+
+	rlen = NLMSG_SPACE(len);
+
+	skb = alloc_skb(rlen, allocation);
+	if (skb==NULL)
+		return NULL;
+
+	nlh = (struct nlmsghdr*)skb_put(skb, rlen);
+	nlh->nlmsg_type = type;
+	nlh->nlmsg_len = NLMSG_LENGTH(len);
+	nlh->nlmsg_seq = seq;
+	nlh->nlmsg_pid = pid;
+	return skb;
+}
+
+void nlmsg_release(struct sk_buff *skb)
+{
+	atomic_dec(skb->users);
+}
+
+
+/*
+ *	Kick message queue.
+ *	Two modes:
+ *		- synchronous (delay==0). Messages are delivered immediately.
+ *		- delayed. Do not deliver, but start delivery timer.
+ */
+
+void __nlmsg_transmit(struct sock *sk, int allocation)
+{
+	start_bh_atomic();
+	if (!sk->protinfo.af_netlink.delay) {
+		if (sk->timer.function) {
+			del_timer(&sk->timer);
+			sk->timer.function = NULL;
+		}
+		end_bh_atomic();
+		nlmsg_flush(sk, allocation);
+		return;
+	}
+	if (!sk->timer.function) {
+		sk->timer.expires = jiffies + sk->protinfo.af_netlink.delay;
+		sk->timer.function = (void (*)(unsigned long))nlmsg_delayed_flush;
+		sk->timer.data = (unsigned long)sk;
+		add_timer(&sk->timer);
+	}
+	end_bh_atomic();
+}
+
+#endif
+
+#ifdef CONFIG_PROC_FS
+static int netlink_read_proc(char *buffer, char **start, off_t offset,
+			     int length, int *eof, void *data)
+{
+	off_t pos=0;
+	off_t begin=0;
+	int len=0;
+	int i;
+	struct sock *s;
+	
+	len+= sprintf(buffer,"sk       Eth Pid    Groups   "
+		      "Rmem     Wmem     Dump     Locks\n");
+	
+	for (i=0; i<MAX_LINKS; i++) {
+		for (s = nl_table[i]; s; s = s->next) {
+			len+=sprintf(buffer+len,"%p %-3d %-6d %08x %-8d %-8d %p %d",
+				     s,
+				     s->protocol,
+				     s->protinfo.af_netlink.pid,
+				     s->protinfo.af_netlink.groups,
+				     atomic_read(&s->rmem_alloc),
+				     atomic_read(&s->wmem_alloc),
+				     s->protinfo.af_netlink.cb,
+				     atomic_read(&s->protinfo.af_netlink.locks)
+				     );
+
+			buffer[len++]='\n';
+		
+			pos=begin+len;
+			if(pos<offset) {
+				len=0;
+				begin=pos;
+			}
+			if(pos>offset+length)
+				goto done;
+		}
+	}
+	*eof = 1;
+
+done:
+	*start=buffer+(offset-begin);
+	len-=(offset-begin);
+	if(len>length)
+		len=length;
+	return len;
+}
+#endif
+
+struct proto_ops netlink_ops = {
+	AF_NETLINK,
+
+	sock_no_dup,
+	netlink_release,
+	netlink_bind,
+	netlink_connect,
+	NULL,
+	NULL,
+	netlink_getname,
+	datagram_poll,
+	sock_no_ioctl,
+	sock_no_listen,
+	sock_no_shutdown,
+	NULL,
+	NULL,
+	sock_no_fcntl,
+	netlink_sendmsg,
+	netlink_recvmsg
+};
+
+struct net_proto_family netlink_family_ops = {
+	AF_NETLINK,
+	netlink_create
+};
+
+void netlink_proto_init(struct net_proto *pro)
+{
+#ifdef CONFIG_PROC_FS
+	struct proc_dir_entry *ent;
+#endif
+	struct sk_buff *dummy_skb;
+
+	if (sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb)) {
+		printk(KERN_CRIT "netlink_proto_init: panic\n");
+		return;
+	}
+	sock_register(&netlink_family_ops);
+#ifdef CONFIG_PROC_FS
+	ent = create_proc_entry("net/netlink", 0, 0);
+	ent->read_proc = netlink_read_proc;
+#endif
+}