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, 1575 insertions, 0 deletions

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
new file mode 100644
index 00000000000..6baddfbedca
--- /dev/null
+++ b/net/ipv4/udp.c
@@ -0,0 +1,1575 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		The User Datagram Protocol (UDP).
+ *
+ * Version:	$Id: udp.c,v 1.102 2002/02/01 22:01:04 davem Exp $
+ *
+ * Authors:	Ross Biro, <bir7@leland.Stanford.Edu>
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ *		Alan Cox, <Alan.Cox@linux.org>
+ *		Hirokazu Takahashi, <taka@valinux.co.jp>
+ *
+ * Fixes:
+ *		Alan Cox	:	verify_area() calls
+ *		Alan Cox	: 	stopped close while in use off icmp
+ *					messages. Not a fix but a botch that
+ *					for udp at least is 'valid'.
+ *		Alan Cox	:	Fixed icmp handling properly
+ *		Alan Cox	: 	Correct error for oversized datagrams
+ *		Alan Cox	:	Tidied select() semantics. 
+ *		Alan Cox	:	udp_err() fixed properly, also now 
+ *					select and read wake correctly on errors
+ *		Alan Cox	:	udp_send verify_area moved to avoid mem leak
+ *		Alan Cox	:	UDP can count its memory
+ *		Alan Cox	:	send to an unknown connection causes
+ *					an ECONNREFUSED off the icmp, but
+ *					does NOT close.
+ *		Alan Cox	:	Switched to new sk_buff handlers. No more backlog!
+ *		Alan Cox	:	Using generic datagram code. Even smaller and the PEEK
+ *					bug no longer crashes it.
+ *		Fred Van Kempen	: 	Net2e support for sk->broadcast.
+ *		Alan Cox	:	Uses skb_free_datagram
+ *		Alan Cox	:	Added get/set sockopt support.
+ *		Alan Cox	:	Broadcasting without option set returns EACCES.
+ *		Alan Cox	:	No wakeup calls. Instead we now use the callbacks.
+ *		Alan Cox	:	Use ip_tos and ip_ttl
+ *		Alan Cox	:	SNMP Mibs
+ *		Alan Cox	:	MSG_DONTROUTE, and 0.0.0.0 support.
+ *		Matt Dillon	:	UDP length checks.
+ *		Alan Cox	:	Smarter af_inet used properly.
+ *		Alan Cox	:	Use new kernel side addressing.
+ *		Alan Cox	:	Incorrect return on truncated datagram receive.
+ *	Arnt Gulbrandsen 	:	New udp_send and stuff
+ *		Alan Cox	:	Cache last socket
+ *		Alan Cox	:	Route cache
+ *		Jon Peatfield	:	Minor efficiency fix to sendto().
+ *		Mike Shaver	:	RFC1122 checks.
+ *		Alan Cox	:	Nonblocking error fix.
+ *	Willy Konynenberg	:	Transparent proxying support.
+ *		Mike McLagan	:	Routing by source
+ *		David S. Miller	:	New socket lookup architecture.
+ *					Last socket cache retained as it
+ *					does have a high hit rate.
+ *		Olaf Kirch	:	Don't linearise iovec on sendmsg.
+ *		Andi Kleen	:	Some cleanups, cache destination entry
+ *					for connect. 
+ *	Vitaly E. Lavrov	:	Transparent proxy revived after year coma.
+ *		Melvin Smith	:	Check msg_name not msg_namelen in sendto(),
+ *					return ENOTCONN for unconnected sockets (POSIX)
+ *		Janos Farkas	:	don't deliver multi/broadcasts to a different
+ *					bound-to-device socket
+ *	Hirokazu Takahashi	:	HW checksumming for outgoing UDP
+ *					datagrams.
+ *	Hirokazu Takahashi	:	sendfile() on UDP works now.
+ *		Arnaldo C. Melo :	convert /proc/net/udp to seq_file
+ *	YOSHIFUJI Hideaki @USAGI and:	Support IPV6_V6ONLY socket option, which
+ *	Alexey Kuznetsov:		allow both IPv4 and IPv6 sockets to bind
+ *					a single port at the same time.
+ *	Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
+ *
+ *
+ *		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 <asm/system.h>
+#include <asm/uaccess.h>
+#include <asm/ioctls.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/module.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/in.h>
+#include <linux/errno.h>
+#include <linux/timer.h>
+#include <linux/mm.h>
+#include <linux/config.h>
+#include <linux/inet.h>
+#include <linux/ipv6.h>
+#include <linux/netdevice.h>
+#include <net/snmp.h>
+#include <net/tcp.h>
+#include <net/protocol.h>
+#include <linux/skbuff.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <net/sock.h>
+#include <net/udp.h>
+#include <net/icmp.h>
+#include <net/route.h>
+#include <net/inet_common.h>
+#include <net/checksum.h>
+#include <net/xfrm.h>
+
+/*
+ *	Snmp MIB for the UDP layer
+ */
+
+DEFINE_SNMP_STAT(struct udp_mib, udp_statistics);
+
+struct hlist_head udp_hash[UDP_HTABLE_SIZE];
+DEFINE_RWLOCK(udp_hash_lock);
+
+/* Shared by v4/v6 udp. */
+int udp_port_rover;
+
+static int udp_v4_get_port(struct sock *sk, unsigned short snum)
+{
+	struct hlist_node *node;
+	struct sock *sk2;
+	struct inet_sock *inet = inet_sk(sk);
+
+	write_lock_bh(&udp_hash_lock);
+	if (snum == 0) {
+		int best_size_so_far, best, result, i;
+
+		if (udp_port_rover > sysctl_local_port_range[1] ||
+		    udp_port_rover < sysctl_local_port_range[0])
+			udp_port_rover = sysctl_local_port_range[0];
+		best_size_so_far = 32767;
+		best = result = udp_port_rover;
+		for (i = 0; i < UDP_HTABLE_SIZE; i++, result++) {
+			struct hlist_head *list;
+			int size;
+
+			list = &udp_hash[result & (UDP_HTABLE_SIZE - 1)];
+			if (hlist_empty(list)) {
+				if (result > sysctl_local_port_range[1])
+					result = sysctl_local_port_range[0] +
+						((result - sysctl_local_port_range[0]) &
+						 (UDP_HTABLE_SIZE - 1));
+				goto gotit;
+			}
+			size = 0;
+			sk_for_each(sk2, node, list)
+				if (++size >= best_size_so_far)
+					goto next;
+			best_size_so_far = size;
+			best = result;
+		next:;
+		}
+		result = best;
+		for(i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++, result += UDP_HTABLE_SIZE) {
+			if (result > sysctl_local_port_range[1])
+				result = sysctl_local_port_range[0]
+					+ ((result - sysctl_local_port_range[0]) &
+					   (UDP_HTABLE_SIZE - 1));
+			if (!udp_lport_inuse(result))
+				break;
+		}
+		if (i >= (1 << 16) / UDP_HTABLE_SIZE)
+			goto fail;
+gotit:
+		udp_port_rover = snum = result;
+	} else {
+		sk_for_each(sk2, node,
+			    &udp_hash[snum & (UDP_HTABLE_SIZE - 1)]) {
+			struct inet_sock *inet2 = inet_sk(sk2);
+
+			if (inet2->num == snum &&
+			    sk2 != sk &&
+			    !ipv6_only_sock(sk2) &&
+			    (!sk2->sk_bound_dev_if ||
+			     !sk->sk_bound_dev_if ||
+			     sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
+			    (!inet2->rcv_saddr ||
+			     !inet->rcv_saddr ||
+			     inet2->rcv_saddr == inet->rcv_saddr) &&
+			    (!sk2->sk_reuse || !sk->sk_reuse))
+				goto fail;
+		}
+	}
+	inet->num = snum;
+	if (sk_unhashed(sk)) {
+		struct hlist_head *h = &udp_hash[snum & (UDP_HTABLE_SIZE - 1)];
+
+		sk_add_node(sk, h);
+		sock_prot_inc_use(sk->sk_prot);
+	}
+	write_unlock_bh(&udp_hash_lock);
+	return 0;
+
+fail:
+	write_unlock_bh(&udp_hash_lock);
+	return 1;
+}
+
+static void udp_v4_hash(struct sock *sk)
+{
+	BUG();
+}
+
+static void udp_v4_unhash(struct sock *sk)
+{
+	write_lock_bh(&udp_hash_lock);
+	if (sk_del_node_init(sk)) {
+		inet_sk(sk)->num = 0;
+		sock_prot_dec_use(sk->sk_prot);
+	}
+	write_unlock_bh(&udp_hash_lock);
+}
+
+/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
+ * harder than this. -DaveM
+ */
+static struct sock *udp_v4_lookup_longway(u32 saddr, u16 sport,
+					  u32 daddr, u16 dport, int dif)
+{
+	struct sock *sk, *result = NULL;
+	struct hlist_node *node;
+	unsigned short hnum = ntohs(dport);
+	int badness = -1;
+
+	sk_for_each(sk, node, &udp_hash[hnum & (UDP_HTABLE_SIZE - 1)]) {
+		struct inet_sock *inet = inet_sk(sk);
+
+		if (inet->num == hnum && !ipv6_only_sock(sk)) {
+			int score = (sk->sk_family == PF_INET ? 1 : 0);
+			if (inet->rcv_saddr) {
+				if (inet->rcv_saddr != daddr)
+					continue;
+				score+=2;
+			}
+			if (inet->daddr) {
+				if (inet->daddr != saddr)
+					continue;
+				score+=2;
+			}
+			if (inet->dport) {
+				if (inet->dport != sport)
+					continue;
+				score+=2;
+			}
+			if (sk->sk_bound_dev_if) {
+				if (sk->sk_bound_dev_if != dif)
+					continue;
+				score+=2;
+			}
+			if(score == 9) {
+				result = sk;
+				break;
+			} else if(score > badness) {
+				result = sk;
+				badness = score;
+			}
+		}
+	}
+	return result;
+}
+
+static __inline__ struct sock *udp_v4_lookup(u32 saddr, u16 sport,
+					     u32 daddr, u16 dport, int dif)
+{
+	struct sock *sk;
+
+	read_lock(&udp_hash_lock);
+	sk = udp_v4_lookup_longway(saddr, sport, daddr, dport, dif);
+	if (sk)
+		sock_hold(sk);
+	read_unlock(&udp_hash_lock);
+	return sk;
+}
+
+static inline struct sock *udp_v4_mcast_next(struct sock *sk,
+					     u16 loc_port, u32 loc_addr,
+					     u16 rmt_port, u32 rmt_addr,
+					     int dif)
+{
+	struct hlist_node *node;
+	struct sock *s = sk;
+	unsigned short hnum = ntohs(loc_port);
+
+	sk_for_each_from(s, node) {
+		struct inet_sock *inet = inet_sk(s);
+
+		if (inet->num != hnum					||
+		    (inet->daddr && inet->daddr != rmt_addr)		||
+		    (inet->dport != rmt_port && inet->dport)		||
+		    (inet->rcv_saddr && inet->rcv_saddr != loc_addr)	||
+		    ipv6_only_sock(s)					||
+		    (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
+			continue;
+		if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
+			continue;
+		goto found;
+  	}
+	s = NULL;
+found:
+  	return s;
+}
+
+/*
+ * This routine is called by the ICMP module when it gets some
+ * sort of error condition.  If err < 0 then the socket should
+ * be closed and the error returned to the user.  If err > 0
+ * it's just the icmp type << 8 | icmp code.  
+ * Header points to the ip header of the error packet. We move
+ * on past this. Then (as it used to claim before adjustment)
+ * header points to the first 8 bytes of the udp header.  We need
+ * to find the appropriate port.
+ */
+
+void udp_err(struct sk_buff *skb, u32 info)
+{
+	struct inet_sock *inet;
+	struct iphdr *iph = (struct iphdr*)skb->data;
+	struct udphdr *uh = (struct udphdr*)(skb->data+(iph->ihl<<2));
+	int type = skb->h.icmph->type;
+	int code = skb->h.icmph->code;
+	struct sock *sk;
+	int harderr;
+	int err;
+
+	sk = udp_v4_lookup(iph->daddr, uh->dest, iph->saddr, uh->source, skb->dev->ifindex);
+	if (sk == NULL) {
+		ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
+    	  	return;	/* No socket for error */
+	}
+
+	err = 0;
+	harderr = 0;
+	inet = inet_sk(sk);
+
+	switch (type) {
+	default:
+	case ICMP_TIME_EXCEEDED:
+		err = EHOSTUNREACH;
+		break;
+	case ICMP_SOURCE_QUENCH:
+		goto out;
+	case ICMP_PARAMETERPROB:
+		err = EPROTO;
+		harderr = 1;
+		break;
+	case ICMP_DEST_UNREACH:
+		if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
+			if (inet->pmtudisc != IP_PMTUDISC_DONT) {
+				err = EMSGSIZE;
+				harderr = 1;
+				break;
+			}
+			goto out;
+		}
+		err = EHOSTUNREACH;
+		if (code <= NR_ICMP_UNREACH) {
+			harderr = icmp_err_convert[code].fatal;
+			err = icmp_err_convert[code].errno;
+		}
+		break;
+	}
+
+	/*
+	 *      RFC1122: OK.  Passes ICMP errors back to application, as per 
+	 *	4.1.3.3.
+	 */
+	if (!inet->recverr) {
+		if (!harderr || sk->sk_state != TCP_ESTABLISHED)
+			goto out;
+	} else {
+		ip_icmp_error(sk, skb, err, uh->dest, info, (u8*)(uh+1));
+	}
+	sk->sk_err = err;
+	sk->sk_error_report(sk);
+out:
+	sock_put(sk);
+}
+
+/*
+ * Throw away all pending data and cancel the corking. Socket is locked.
+ */
+static void udp_flush_pending_frames(struct sock *sk)
+{
+	struct udp_sock *up = udp_sk(sk);
+
+	if (up->pending) {
+		up->len = 0;
+		up->pending = 0;
+		ip_flush_pending_frames(sk);
+	}
+}
+
+/*
+ * Push out all pending data as one UDP datagram. Socket is locked.
+ */
+static int udp_push_pending_frames(struct sock *sk, struct udp_sock *up)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct flowi *fl = &inet->cork.fl;
+	struct sk_buff *skb;
+	struct udphdr *uh;
+	int err = 0;
+
+	/* Grab the skbuff where UDP header space exists. */
+	if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
+		goto out;
+
+	/*
+	 * Create a UDP header
+	 */
+	uh = skb->h.uh;
+	uh->source = fl->fl_ip_sport;
+	uh->dest = fl->fl_ip_dport;
+	uh->len = htons(up->len);
+	uh->check = 0;
+
+	if (sk->sk_no_check == UDP_CSUM_NOXMIT) {
+		skb->ip_summed = CHECKSUM_NONE;
+		goto send;
+	}
+
+	if (skb_queue_len(&sk->sk_write_queue) == 1) {
+		/*
+		 * Only one fragment on the socket.
+		 */
+		if (skb->ip_summed == CHECKSUM_HW) {
+			skb->csum = offsetof(struct udphdr, check);
+			uh->check = ~csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst,
+					up->len, IPPROTO_UDP, 0);
+		} else {
+			skb->csum = csum_partial((char *)uh,
+					sizeof(struct udphdr), skb->csum);
+			uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst,
+					up->len, IPPROTO_UDP, skb->csum);
+			if (uh->check == 0)
+				uh->check = -1;
+		}
+	} else {
+		unsigned int csum = 0;
+		/*
+		 * HW-checksum won't work as there are two or more 
+		 * fragments on the socket so that all csums of sk_buffs
+		 * should be together.
+		 */
+		if (skb->ip_summed == CHECKSUM_HW) {
+			int offset = (unsigned char *)uh - skb->data;
+			skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
+
+			skb->ip_summed = CHECKSUM_NONE;
+		} else {
+			skb->csum = csum_partial((char *)uh,
+					sizeof(struct udphdr), skb->csum);
+		}
+
+		skb_queue_walk(&sk->sk_write_queue, skb) {
+			csum = csum_add(csum, skb->csum);
+		}
+		uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst,
+				up->len, IPPROTO_UDP, csum);
+		if (uh->check == 0)
+			uh->check = -1;
+	}
+send:
+	err = ip_push_pending_frames(sk);
+out:
+	up->len = 0;
+	up->pending = 0;
+	return err;
+}
+
+
+static unsigned short udp_check(struct udphdr *uh, int len, unsigned long saddr, unsigned long daddr, unsigned long base)
+{
+	return(csum_tcpudp_magic(saddr, daddr, len, IPPROTO_UDP, base));
+}
+
+int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
+		size_t len)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct udp_sock *up = udp_sk(sk);
+	int ulen = len;
+	struct ipcm_cookie ipc;
+	struct rtable *rt = NULL;
+	int free = 0;
+	int connected = 0;
+	u32 daddr, faddr, saddr;
+	u16 dport;
+	u8  tos;
+	int err;
+	int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
+
+	if (len > 0xFFFF)
+		return -EMSGSIZE;
+
+	/* 
+	 *	Check the flags.
+	 */
+
+	if (msg->msg_flags&MSG_OOB)	/* Mirror BSD error message compatibility */
+		return -EOPNOTSUPP;
+
+	ipc.opt = NULL;
+
+	if (up->pending) {
+		/*
+		 * There are pending frames.
+	 	 * The socket lock must be held while it's corked.
+		 */
+		lock_sock(sk);
+		if (likely(up->pending)) {
+			if (unlikely(up->pending != AF_INET)) {
+				release_sock(sk);
+				return -EINVAL;
+			}
+ 			goto do_append_data;
+		}
+		release_sock(sk);
+	}
+	ulen += sizeof(struct udphdr);
+
+	/*
+	 *	Get and verify the address. 
+	 */
+	if (msg->msg_name) {
+		struct sockaddr_in * usin = (struct sockaddr_in*)msg->msg_name;
+		if (msg->msg_namelen < sizeof(*usin))
+			return -EINVAL;
+		if (usin->sin_family != AF_INET) {
+			if (usin->sin_family != AF_UNSPEC)
+				return -EAFNOSUPPORT;
+		}
+
+		daddr = usin->sin_addr.s_addr;
+		dport = usin->sin_port;
+		if (dport == 0)
+			return -EINVAL;
+	} else {
+		if (sk->sk_state != TCP_ESTABLISHED)
+			return -EDESTADDRREQ;
+		daddr = inet->daddr;
+		dport = inet->dport;
+		/* Open fast path for connected socket.
+		   Route will not be used, if at least one option is set.
+		 */
+		connected = 1;
+  	}
+	ipc.addr = inet->saddr;
+
+	ipc.oif = sk->sk_bound_dev_if;
+	if (msg->msg_controllen) {
+		err = ip_cmsg_send(msg, &ipc);
+		if (err)
+			return err;
+		if (ipc.opt)
+			free = 1;
+		connected = 0;
+	}
+	if (!ipc.opt)
+		ipc.opt = inet->opt;
+
+	saddr = ipc.addr;
+	ipc.addr = faddr = daddr;
+
+	if (ipc.opt && ipc.opt->srr) {
+		if (!daddr)
+			return -EINVAL;
+		faddr = ipc.opt->faddr;
+		connected = 0;
+	}
+	tos = RT_TOS(inet->tos);
+	if (sock_flag(sk, SOCK_LOCALROUTE) ||
+	    (msg->msg_flags & MSG_DONTROUTE) || 
+	    (ipc.opt && ipc.opt->is_strictroute)) {
+		tos |= RTO_ONLINK;
+		connected = 0;
+	}
+
+	if (MULTICAST(daddr)) {
+		if (!ipc.oif)
+			ipc.oif = inet->mc_index;
+		if (!saddr)
+			saddr = inet->mc_addr;
+		connected = 0;
+	}
+
+	if (connected)
+		rt = (struct rtable*)sk_dst_check(sk, 0);
+
+	if (rt == NULL) {
+		struct flowi fl = { .oif = ipc.oif,
+				    .nl_u = { .ip4_u =
+					      { .daddr = faddr,
+						.saddr = saddr,
+						.tos = tos } },
+				    .proto = IPPROTO_UDP,
+				    .uli_u = { .ports =
+					       { .sport = inet->sport,
+						 .dport = dport } } };
+		err = ip_route_output_flow(&rt, &fl, sk, !(msg->msg_flags&MSG_DONTWAIT));
+		if (err)
+			goto out;
+
+		err = -EACCES;
+		if ((rt->rt_flags & RTCF_BROADCAST) &&
+		    !sock_flag(sk, SOCK_BROADCAST))
+			goto out;
+		if (connected)
+			sk_dst_set(sk, dst_clone(&rt->u.dst));
+	}
+
+	if (msg->msg_flags&MSG_CONFIRM)
+		goto do_confirm;
+back_from_confirm:
+
+	saddr = rt->rt_src;
+	if (!ipc.addr)
+		daddr = ipc.addr = rt->rt_dst;
+
+	lock_sock(sk);
+	if (unlikely(up->pending)) {
+		/* The socket is already corked while preparing it. */
+		/* ... which is an evident application bug. --ANK */
+		release_sock(sk);
+
+		NETDEBUG(if (net_ratelimit()) printk(KERN_DEBUG "udp cork app bug 2\n"));
+		err = -EINVAL;
+		goto out;
+	}
+	/*
+	 *	Now cork the socket to pend data.
+	 */
+	inet->cork.fl.fl4_dst = daddr;
+	inet->cork.fl.fl_ip_dport = dport;
+	inet->cork.fl.fl4_src = saddr;
+	inet->cork.fl.fl_ip_sport = inet->sport;
+	up->pending = AF_INET;
+
+do_append_data:
+	up->len += ulen;
+	err = ip_append_data(sk, ip_generic_getfrag, msg->msg_iov, ulen, 
+			sizeof(struct udphdr), &ipc, rt, 
+			corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
+	if (err)
+		udp_flush_pending_frames(sk);
+	else if (!corkreq)
+		err = udp_push_pending_frames(sk, up);
+	release_sock(sk);
+
+out:
+	ip_rt_put(rt);
+	if (free)
+		kfree(ipc.opt);
+	if (!err) {
+		UDP_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS);
+		return len;
+	}
+	return err;
+
+do_confirm:
+	dst_confirm(&rt->u.dst);
+	if (!(msg->msg_flags&MSG_PROBE) || len)
+		goto back_from_confirm;
+	err = 0;
+	goto out;
+}
+
+static int udp_sendpage(struct sock *sk, struct page *page, int offset,
+			size_t size, int flags)
+{
+	struct udp_sock *up = udp_sk(sk);
+	int ret;
+
+	if (!up->pending) {
+		struct msghdr msg = {	.msg_flags = flags|MSG_MORE };
+
+		/* Call udp_sendmsg to specify destination address which
+		 * sendpage interface can't pass.
+		 * This will succeed only when the socket is connected.
+		 */
+		ret = udp_sendmsg(NULL, sk, &msg, 0);
+		if (ret < 0)
+			return ret;
+	}
+
+	lock_sock(sk);
+
+	if (unlikely(!up->pending)) {
+		release_sock(sk);
+
+		NETDEBUG(if (net_ratelimit()) printk(KERN_DEBUG "udp cork app bug 3\n"));
+		return -EINVAL;
+	}
+
+	ret = ip_append_page(sk, page, offset, size, flags);
+	if (ret == -EOPNOTSUPP) {
+		release_sock(sk);
+		return sock_no_sendpage(sk->sk_socket, page, offset,
+					size, flags);
+	}
+	if (ret < 0) {
+		udp_flush_pending_frames(sk);
+		goto out;
+	}
+
+	up->len += size;
+	if (!(up->corkflag || (flags&MSG_MORE)))
+		ret = udp_push_pending_frames(sk, up);
+	if (!ret)
+		ret = size;
+out:
+	release_sock(sk);
+	return ret;
+}
+
+/*
+ *	IOCTL requests applicable to the UDP protocol
+ */
+ 
+int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
+{
+	switch(cmd) 
+	{
+		case SIOCOUTQ:
+		{
+			int amount = atomic_read(&sk->sk_wmem_alloc);
+			return put_user(amount, (int __user *)arg);
+		}
+
+		case SIOCINQ:
+		{
+			struct sk_buff *skb;
+			unsigned long amount;
+
+			amount = 0;
+			spin_lock_irq(&sk->sk_receive_queue.lock);
+			skb = skb_peek(&sk->sk_receive_queue);
+			if (skb != NULL) {
+				/*
+				 * We will only return the amount
+				 * of this packet since that is all
+				 * that will be read.
+				 */
+				amount = skb->len - sizeof(struct udphdr);
+			}
+			spin_unlock_irq(&sk->sk_receive_queue.lock);
+			return put_user(amount, (int __user *)arg);
+		}
+
+		default:
+			return -ENOIOCTLCMD;
+	}
+	return(0);
+}
+
+static __inline__ int __udp_checksum_complete(struct sk_buff *skb)
+{
+	return (unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum));
+}
+
+static __inline__ int udp_checksum_complete(struct sk_buff *skb)
+{
+	return skb->ip_summed != CHECKSUM_UNNECESSARY &&
+		__udp_checksum_complete(skb);
+}
+
+/*
+ * 	This should be easy, if there is something there we
+ * 	return it, otherwise we block.
+ */
+
+static int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
+		       size_t len, int noblock, int flags, int *addr_len)
+{
+	struct inet_sock *inet = inet_sk(sk);
+  	struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
+  	struct sk_buff *skb;
+  	int copied, err;
+
+	/*
+	 *	Check any passed addresses
+	 */
+	if (addr_len)
+		*addr_len=sizeof(*sin);
+
+	if (flags & MSG_ERRQUEUE)
+		return ip_recv_error(sk, msg, len);
+
+try_again:
+	skb = skb_recv_datagram(sk, flags, noblock, &err);
+	if (!skb)
+		goto out;
+  
+  	copied = skb->len - sizeof(struct udphdr);
+	if (copied > len) {
+		copied = len;
+		msg->msg_flags |= MSG_TRUNC;
+	}
+
+	if (skb->ip_summed==CHECKSUM_UNNECESSARY) {
+		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
+					      copied);
+	} else if (msg->msg_flags&MSG_TRUNC) {
+		if (__udp_checksum_complete(skb))
+			goto csum_copy_err;
+		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
+					      copied);
+	} else {
+		err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
+
+		if (err == -EINVAL)
+			goto csum_copy_err;
+	}
+
+	if (err)
+		goto out_free;
+
+	sock_recv_timestamp(msg, sk, skb);
+
+	/* Copy the address. */
+	if (sin)
+	{
+		sin->sin_family = AF_INET;
+		sin->sin_port = skb->h.uh->source;
+		sin->sin_addr.s_addr = skb->nh.iph->saddr;
+		memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
+  	}
+	if (inet->cmsg_flags)
+		ip_cmsg_recv(msg, skb);
+
+	err = copied;
+	if (flags & MSG_TRUNC)
+		err = skb->len - sizeof(struct udphdr);
+  
+out_free:
+  	skb_free_datagram(sk, skb);
+out:
+  	return err;
+
+csum_copy_err:
+	UDP_INC_STATS_BH(UDP_MIB_INERRORS);
+
+	/* Clear queue. */
+	if (flags&MSG_PEEK) {
+		int clear = 0;
+		spin_lock_irq(&sk->sk_receive_queue.lock);
+		if (skb == skb_peek(&sk->sk_receive_queue)) {
+			__skb_unlink(skb, &sk->sk_receive_queue);
+			clear = 1;
+		}
+		spin_unlock_irq(&sk->sk_receive_queue.lock);
+		if (clear)
+			kfree_skb(skb);
+	}
+
+	skb_free_datagram(sk, skb);
+
+	if (noblock)
+		return -EAGAIN;	
+	goto try_again;
+}
+
+
+int udp_disconnect(struct sock *sk, int flags)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	/*
+	 *	1003.1g - break association.
+	 */
+	 
+	sk->sk_state = TCP_CLOSE;
+	inet->daddr = 0;
+	inet->dport = 0;
+	sk->sk_bound_dev_if = 0;
+	if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
+		inet_reset_saddr(sk);
+
+	if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
+		sk->sk_prot->unhash(sk);
+		inet->sport = 0;
+	}
+	sk_dst_reset(sk);
+	return 0;
+}
+
+static void udp_close(struct sock *sk, long timeout)
+{
+	sk_common_release(sk);
+}
+
+/* return:
+ * 	1  if the the UDP system should process it
+ *	0  if we should drop this packet
+ * 	-1 if it should get processed by xfrm4_rcv_encap
+ */
+static int udp_encap_rcv(struct sock * sk, struct sk_buff *skb)
+{
+#ifndef CONFIG_XFRM
+	return 1; 
+#else
+	struct udp_sock *up = udp_sk(sk);
+  	struct udphdr *uh = skb->h.uh;
+	struct iphdr *iph;
+	int iphlen, len;
+  
+	__u8 *udpdata = (__u8 *)uh + sizeof(struct udphdr);
+	__u32 *udpdata32 = (__u32 *)udpdata;
+	__u16 encap_type = up->encap_type;
+
+	/* if we're overly short, let UDP handle it */
+	if (udpdata > skb->tail)
+		return 1;
+
+	/* if this is not encapsulated socket, then just return now */
+	if (!encap_type)
+		return 1;
+
+	len = skb->tail - udpdata;
+
+	switch (encap_type) {
+	default:
+	case UDP_ENCAP_ESPINUDP:
+		/* Check if this is a keepalive packet.  If so, eat it. */
+		if (len == 1 && udpdata[0] == 0xff) {
+			return 0;
+		} else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0 ) {
+			/* ESP Packet without Non-ESP header */
+			len = sizeof(struct udphdr);
+		} else
+			/* Must be an IKE packet.. pass it through */
+			return 1;
+		break;
+	case UDP_ENCAP_ESPINUDP_NON_IKE:
+		/* Check if this is a keepalive packet.  If so, eat it. */
+		if (len == 1 && udpdata[0] == 0xff) {
+			return 0;
+		} else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) &&
+			   udpdata32[0] == 0 && udpdata32[1] == 0) {
+			
+			/* ESP Packet with Non-IKE marker */
+			len = sizeof(struct udphdr) + 2 * sizeof(u32);
+		} else
+			/* Must be an IKE packet.. pass it through */
+			return 1;
+		break;
+	}
+
+	/* At this point we are sure that this is an ESPinUDP packet,
+	 * so we need to remove 'len' bytes from the packet (the UDP
+	 * header and optional ESP marker bytes) and then modify the
+	 * protocol to ESP, and then call into the transform receiver.
+	 */
+
+	/* Now we can update and verify the packet length... */
+	iph = skb->nh.iph;
+	iphlen = iph->ihl << 2;
+	iph->tot_len = htons(ntohs(iph->tot_len) - len);
+	if (skb->len < iphlen + len) {
+		/* packet is too small!?! */
+		return 0;
+	}
+
+	/* pull the data buffer up to the ESP header and set the
+	 * transport header to point to ESP.  Keep UDP on the stack
+	 * for later.
+	 */
+	skb->h.raw = skb_pull(skb, len);
+
+	/* modify the protocol (it's ESP!) */
+	iph->protocol = IPPROTO_ESP;
+
+	/* and let the caller know to send this into the ESP processor... */
+	return -1;
+#endif
+}
+
+/* returns:
+ *  -1: error
+ *   0: success
+ *  >0: "udp encap" protocol resubmission
+ *
+ * Note that in the success and error cases, the skb is assumed to
+ * have either been requeued or freed.
+ */
+static int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
+{
+	struct udp_sock *up = udp_sk(sk);
+
+	/*
+	 *	Charge it to the socket, dropping if the queue is full.
+	 */
+	if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) {
+		kfree_skb(skb);
+		return -1;
+	}
+
+	if (up->encap_type) {
+		/*
+		 * This is an encapsulation socket, so let's see if this is
+		 * an encapsulated packet.
+		 * If it's a keepalive packet, then just eat it.
+		 * If it's an encapsulateed packet, then pass it to the
+		 * IPsec xfrm input and return the response
+		 * appropriately.  Otherwise, just fall through and
+		 * pass this up the UDP socket.
+		 */
+		int ret;
+
+		ret = udp_encap_rcv(sk, skb);
+		if (ret == 0) {
+			/* Eat the packet .. */
+			kfree_skb(skb);
+			return 0;
+		}
+		if (ret < 0) {
+			/* process the ESP packet */
+			ret = xfrm4_rcv_encap(skb, up->encap_type);
+			UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS);
+			return -ret;
+		}
+		/* FALLTHROUGH -- it's a UDP Packet */
+	}
+
+	if (sk->sk_filter && skb->ip_summed != CHECKSUM_UNNECESSARY) {
+		if (__udp_checksum_complete(skb)) {
+			UDP_INC_STATS_BH(UDP_MIB_INERRORS);
+			kfree_skb(skb);
+			return -1;
+		}
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+	}
+
+	if (sock_queue_rcv_skb(sk,skb)<0) {
+		UDP_INC_STATS_BH(UDP_MIB_INERRORS);
+		kfree_skb(skb);
+		return -1;
+	}
+	UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS);
+	return 0;
+}
+
+/*
+ *	Multicasts and broadcasts go to each listener.
+ *
+ *	Note: called only from the BH handler context,
+ *	so we don't need to lock the hashes.
+ */
+static int udp_v4_mcast_deliver(struct sk_buff *skb, struct udphdr *uh,
+				 u32 saddr, u32 daddr)
+{
+	struct sock *sk;
+	int dif;
+
+	read_lock(&udp_hash_lock);
+	sk = sk_head(&udp_hash[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]);
+	dif = skb->dev->ifindex;
+	sk = udp_v4_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif);
+	if (sk) {
+		struct sock *sknext = NULL;
+
+		do {
+			struct sk_buff *skb1 = skb;
+
+			sknext = udp_v4_mcast_next(sk_next(sk), uh->dest, daddr,
+						   uh->source, saddr, dif);
+			if(sknext)
+				skb1 = skb_clone(skb, GFP_ATOMIC);
+
+			if(skb1) {
+				int ret = udp_queue_rcv_skb(sk, skb1);
+				if (ret > 0)
+					/* we should probably re-process instead
+					 * of dropping packets here. */
+					kfree_skb(skb1);
+			}
+			sk = sknext;
+		} while(sknext);
+	} else
+		kfree_skb(skb);
+	read_unlock(&udp_hash_lock);
+	return 0;
+}
+
+/* Initialize UDP checksum. If exited with zero value (success),
+ * CHECKSUM_UNNECESSARY means, that no more checks are required.
+ * Otherwise, csum completion requires chacksumming packet body,
+ * including udp header and folding it to skb->csum.
+ */
+static int udp_checksum_init(struct sk_buff *skb, struct udphdr *uh,
+			     unsigned short ulen, u32 saddr, u32 daddr)
+{
+	if (uh->check == 0) {
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+	} else if (skb->ip_summed == CHECKSUM_HW) {
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+		if (!udp_check(uh, ulen, saddr, daddr, skb->csum))
+			return 0;
+		NETDEBUG(if (net_ratelimit()) printk(KERN_DEBUG "udp v4 hw csum failure.\n"));
+		skb->ip_summed = CHECKSUM_NONE;
+	}
+	if (skb->ip_summed != CHECKSUM_UNNECESSARY)
+		skb->csum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
+	/* Probably, we should checksum udp header (it should be in cache
+	 * in any case) and data in tiny packets (< rx copybreak).
+	 */
+	return 0;
+}
+
+/*
+ *	All we need to do is get the socket, and then do a checksum. 
+ */
+ 
+int udp_rcv(struct sk_buff *skb)
+{
+  	struct sock *sk;
+  	struct udphdr *uh;
+	unsigned short ulen;
+	struct rtable *rt = (struct rtable*)skb->dst;
+	u32 saddr = skb->nh.iph->saddr;
+	u32 daddr = skb->nh.iph->daddr;
+	int len = skb->len;
+
+	/*
+	 *	Validate the packet and the UDP length.
+	 */
+	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
+		goto no_header;
+
+	uh = skb->h.uh;
+
+	ulen = ntohs(uh->len);
+
+	if (ulen > len || ulen < sizeof(*uh))
+		goto short_packet;
+
+	if (pskb_trim(skb, ulen))
+		goto short_packet;
+
+	if (udp_checksum_init(skb, uh, ulen, saddr, daddr) < 0)
+		goto csum_error;
+
+	if(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
+		return udp_v4_mcast_deliver(skb, uh, saddr, daddr);
+
+	sk = udp_v4_lookup(saddr, uh->source, daddr, uh->dest, skb->dev->ifindex);
+
+	if (sk != NULL) {
+		int ret = udp_queue_rcv_skb(sk, skb);
+		sock_put(sk);
+
+		/* a return value > 0 means to resubmit the input, but
+		 * it it wants the return to be -protocol, or 0
+		 */
+		if (ret > 0)
+			return -ret;
+		return 0;
+	}
+
+	if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
+		goto drop;
+
+	/* No socket. Drop packet silently, if checksum is wrong */
+	if (udp_checksum_complete(skb))
+		goto csum_error;
+
+	UDP_INC_STATS_BH(UDP_MIB_NOPORTS);
+	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
+
+	/*
+	 * Hmm.  We got an UDP packet to a port to which we
+	 * don't wanna listen.  Ignore it.
+	 */
+	kfree_skb(skb);
+	return(0);
+
+short_packet:
+	NETDEBUG(if (net_ratelimit())
+		printk(KERN_DEBUG "UDP: short packet: From %u.%u.%u.%u:%u %d/%d to %u.%u.%u.%u:%u\n",
+			NIPQUAD(saddr),
+			ntohs(uh->source),
+			ulen,
+			len,
+			NIPQUAD(daddr),
+			ntohs(uh->dest)));
+no_header:
+	UDP_INC_STATS_BH(UDP_MIB_INERRORS);
+	kfree_skb(skb);
+	return(0);
+
+csum_error:
+	/* 
+	 * RFC1122: OK.  Discards the bad packet silently (as far as 
+	 * the network is concerned, anyway) as per 4.1.3.4 (MUST). 
+	 */
+	NETDEBUG(if (net_ratelimit())
+		 printk(KERN_DEBUG "UDP: bad checksum. From %d.%d.%d.%d:%d to %d.%d.%d.%d:%d ulen %d\n",
+			NIPQUAD(saddr),
+			ntohs(uh->source),
+			NIPQUAD(daddr),
+			ntohs(uh->dest),
+			ulen));
+drop:
+	UDP_INC_STATS_BH(UDP_MIB_INERRORS);
+	kfree_skb(skb);
+	return(0);
+}
+
+static int udp_destroy_sock(struct sock *sk)
+{
+	lock_sock(sk);
+	udp_flush_pending_frames(sk);
+	release_sock(sk);
+	return 0;
+}
+
+/*
+ *	Socket option code for UDP
+ */
+static int udp_setsockopt(struct sock *sk, int level, int optname, 
+			  char __user *optval, int optlen)
+{
+	struct udp_sock *up = udp_sk(sk);
+	int val;
+	int err = 0;
+
+	if (level != SOL_UDP)
+		return ip_setsockopt(sk, level, optname, optval, optlen);
+
+	if(optlen<sizeof(int))
+		return -EINVAL;
+
+	if (get_user(val, (int __user *)optval))
+		return -EFAULT;
+
+	switch(optname) {
+	case UDP_CORK:
+		if (val != 0) {
+			up->corkflag = 1;
+		} else {
+			up->corkflag = 0;
+			lock_sock(sk);
+			udp_push_pending_frames(sk, up);
+			release_sock(sk);
+		}
+		break;
+		
+	case UDP_ENCAP:
+		switch (val) {
+		case 0:
+		case UDP_ENCAP_ESPINUDP:
+		case UDP_ENCAP_ESPINUDP_NON_IKE:
+			up->encap_type = val;
+			break;
+		default:
+			err = -ENOPROTOOPT;
+			break;
+		}
+		break;
+
+	default:
+		err = -ENOPROTOOPT;
+		break;
+	};
+
+	return err;
+}
+
+static int udp_getsockopt(struct sock *sk, int level, int optname, 
+			  char __user *optval, int __user *optlen)
+{
+	struct udp_sock *up = udp_sk(sk);
+	int val, len;
+
+	if (level != SOL_UDP)
+		return ip_getsockopt(sk, level, optname, optval, optlen);
+
+	if(get_user(len,optlen))
+		return -EFAULT;
+
+	len = min_t(unsigned int, len, sizeof(int));
+	
+	if(len < 0)
+		return -EINVAL;
+
+	switch(optname) {
+	case UDP_CORK:
+		val = up->corkflag;
+		break;
+
+	case UDP_ENCAP:
+		val = up->encap_type;
+		break;
+
+	default:
+		return -ENOPROTOOPT;
+	};
+
+  	if(put_user(len, optlen))
+  		return -EFAULT;
+	if(copy_to_user(optval, &val,len))
+		return -EFAULT;
+  	return 0;
+}
+
+/**
+ * 	udp_poll - wait for a UDP event.
+ *	@file - file struct
+ *	@sock - socket
+ *	@wait - poll table
+ *
+ *	This is same as datagram poll, except for the special case of 
+ *	blocking sockets. If application is using a blocking fd
+ *	and a packet with checksum error is in the queue;
+ *	then it could get return from select indicating data available
+ *	but then block when reading it. Add special case code
+ *	to work around these arguably broken applications.
+ */
+unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
+{
+	unsigned int mask = datagram_poll(file, sock, wait);
+	struct sock *sk = sock->sk;
+	
+	/* Check for false positives due to checksum errors */
+	if ( (mask & POLLRDNORM) &&
+	     !(file->f_flags & O_NONBLOCK) &&
+	     !(sk->sk_shutdown & RCV_SHUTDOWN)){
+		struct sk_buff_head *rcvq = &sk->sk_receive_queue;
+		struct sk_buff *skb;
+
+		spin_lock_irq(&rcvq->lock);
+		while ((skb = skb_peek(rcvq)) != NULL) {
+			if (udp_checksum_complete(skb)) {
+				UDP_INC_STATS_BH(UDP_MIB_INERRORS);
+				__skb_unlink(skb, rcvq);
+				kfree_skb(skb);
+			} else {
+				skb->ip_summed = CHECKSUM_UNNECESSARY;
+				break;
+			}
+		}
+		spin_unlock_irq(&rcvq->lock);
+
+		/* nothing to see, move along */
+		if (skb == NULL)
+			mask &= ~(POLLIN | POLLRDNORM);
+	}
+
+	return mask;
+	
+}
+
+struct proto udp_prot = {
+ 	.name =		"UDP",
+	.owner =	THIS_MODULE,
+	.close =	udp_close,
+	.connect =	ip4_datagram_connect,
+	.disconnect =	udp_disconnect,
+	.ioctl =	udp_ioctl,
+	.destroy =	udp_destroy_sock,
+	.setsockopt =	udp_setsockopt,
+	.getsockopt =	udp_getsockopt,
+	.sendmsg =	udp_sendmsg,
+	.recvmsg =	udp_recvmsg,
+	.sendpage =	udp_sendpage,
+	.backlog_rcv =	udp_queue_rcv_skb,
+	.hash =		udp_v4_hash,
+	.unhash =	udp_v4_unhash,
+	.get_port =	udp_v4_get_port,
+	.obj_size =	sizeof(struct udp_sock),
+};
+
+/* ------------------------------------------------------------------------ */
+#ifdef CONFIG_PROC_FS
+
+static struct sock *udp_get_first(struct seq_file *seq)
+{
+	struct sock *sk;
+	struct udp_iter_state *state = seq->private;
+
+	for (state->bucket = 0; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) {
+		struct hlist_node *node;
+		sk_for_each(sk, node, &udp_hash[state->bucket]) {
+			if (sk->sk_family == state->family)
+				goto found;
+		}
+	}
+	sk = NULL;
+found:
+	return sk;
+}
+
+static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
+{
+	struct udp_iter_state *state = seq->private;
+
+	do {
+		sk = sk_next(sk);
+try_again:
+		;
+	} while (sk && sk->sk_family != state->family);
+
+	if (!sk && ++state->bucket < UDP_HTABLE_SIZE) {
+		sk = sk_head(&udp_hash[state->bucket]);
+		goto try_again;
+	}
+	return sk;
+}
+
+static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
+{
+	struct sock *sk = udp_get_first(seq);
+
+	if (sk)
+		while(pos && (sk = udp_get_next(seq, sk)) != NULL)
+			--pos;
+	return pos ? NULL : sk;
+}
+
+static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	read_lock(&udp_hash_lock);
+	return *pos ? udp_get_idx(seq, *pos-1) : (void *)1;
+}
+
+static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct sock *sk;
+
+	if (v == (void *)1)
+		sk = udp_get_idx(seq, 0);
+	else
+		sk = udp_get_next(seq, v);
+
+	++*pos;
+	return sk;
+}
+
+static void udp_seq_stop(struct seq_file *seq, void *v)
+{
+	read_unlock(&udp_hash_lock);
+}
+
+static int udp_seq_open(struct inode *inode, struct file *file)
+{
+	struct udp_seq_afinfo *afinfo = PDE(inode)->data;
+	struct seq_file *seq;
+	int rc = -ENOMEM;
+	struct udp_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
+
+	if (!s)
+		goto out;
+	memset(s, 0, sizeof(*s));
+	s->family		= afinfo->family;
+	s->seq_ops.start	= udp_seq_start;
+	s->seq_ops.next		= udp_seq_next;
+	s->seq_ops.show		= afinfo->seq_show;
+	s->seq_ops.stop		= udp_seq_stop;
+
+	rc = seq_open(file, &s->seq_ops);
+	if (rc)
+		goto out_kfree;
+
+	seq	     = file->private_data;
+	seq->private = s;
+out:
+	return rc;
+out_kfree:
+	kfree(s);
+	goto out;
+}
+
+/* ------------------------------------------------------------------------ */
+int udp_proc_register(struct udp_seq_afinfo *afinfo)
+{
+	struct proc_dir_entry *p;
+	int rc = 0;
+
+	if (!afinfo)
+		return -EINVAL;
+	afinfo->seq_fops->owner		= afinfo->owner;
+	afinfo->seq_fops->open		= udp_seq_open;
+	afinfo->seq_fops->read		= seq_read;
+	afinfo->seq_fops->llseek	= seq_lseek;
+	afinfo->seq_fops->release	= seq_release_private;
+
+	p = proc_net_fops_create(afinfo->name, S_IRUGO, afinfo->seq_fops);
+	if (p)
+		p->data = afinfo;
+	else
+		rc = -ENOMEM;
+	return rc;
+}
+
+void udp_proc_unregister(struct udp_seq_afinfo *afinfo)
+{
+	if (!afinfo)
+		return;
+	proc_net_remove(afinfo->name);
+	memset(afinfo->seq_fops, 0, sizeof(*afinfo->seq_fops));
+}
+
+/* ------------------------------------------------------------------------ */
+static void udp4_format_sock(struct sock *sp, char *tmpbuf, int bucket)
+{
+	struct inet_sock *inet = inet_sk(sp);
+	unsigned int dest = inet->daddr;
+	unsigned int src  = inet->rcv_saddr;
+	__u16 destp	  = ntohs(inet->dport);
+	__u16 srcp	  = ntohs(inet->sport);
+
+	sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"
+		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p",
+		bucket, src, srcp, dest, destp, sp->sk_state, 
+		atomic_read(&sp->sk_wmem_alloc),
+		atomic_read(&sp->sk_rmem_alloc),
+		0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
+		atomic_read(&sp->sk_refcnt), sp);
+}
+
+static int udp4_seq_show(struct seq_file *seq, void *v)
+{
+	if (v == SEQ_START_TOKEN)
+		seq_printf(seq, "%-127s\n",
+			   "  sl  local_address rem_address   st tx_queue "
+			   "rx_queue tr tm->when retrnsmt   uid  timeout "
+			   "inode");
+	else {
+		char tmpbuf[129];
+		struct udp_iter_state *state = seq->private;
+
+		udp4_format_sock(v, tmpbuf, state->bucket);
+		seq_printf(seq, "%-127s\n", tmpbuf);
+	}
+	return 0;
+}
+
+/* ------------------------------------------------------------------------ */
+static struct file_operations udp4_seq_fops;
+static struct udp_seq_afinfo udp4_seq_afinfo = {
+	.owner		= THIS_MODULE,
+	.name		= "udp",
+	.family		= AF_INET,
+	.seq_show	= udp4_seq_show,
+	.seq_fops	= &udp4_seq_fops,
+};
+
+int __init udp4_proc_init(void)
+{
+	return udp_proc_register(&udp4_seq_afinfo);
+}
+
+void udp4_proc_exit(void)
+{
+	udp_proc_unregister(&udp4_seq_afinfo);
+}
+#endif /* CONFIG_PROC_FS */
+
+EXPORT_SYMBOL(udp_disconnect);
+EXPORT_SYMBOL(udp_hash);
+EXPORT_SYMBOL(udp_hash_lock);
+EXPORT_SYMBOL(udp_ioctl);
+EXPORT_SYMBOL(udp_port_rover);
+EXPORT_SYMBOL(udp_prot);
+EXPORT_SYMBOL(udp_sendmsg);
+EXPORT_SYMBOL(udp_poll);
+
+#ifdef CONFIG_PROC_FS
+EXPORT_SYMBOL(udp_proc_register);
+EXPORT_SYMBOL(udp_proc_unregister);
+#endif