path: root/net/ipv6/udp.c

/*
 *	UDP over IPv6
 *	Linux INET6 implementation
 *
 *	Authors:
 *	Pedro Roque		<roque@di.fc.ul.pt>
 *
 *	Based on linux/ipv4/udp.c
 *
 *	$Id: udp.c,v 1.65 2002/02/01 22:01:04 davem Exp $
 *
 *	Fixes:
 *	Hideaki YOSHIFUJI	:	sin6_scope_id support
 *	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.
 *      Kazunori MIYAZAWA @USAGI:       change process style to use ip6_append_data
 *      YOSHIFUJI Hideaki @USAGI:	convert /proc/net/udp6 to seq_file.
 *
 *	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/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/in6.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/ipv6.h>
#include <linux/icmpv6.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <asm/uaccess.h>

#include <net/ndisc.h>
#include <net/protocol.h>
#include <net/transp_v6.h>
#include <net/ip6_route.h>
#include <net/raw.h>
#include <net/tcp_states.h>
#include <net/ip6_checksum.h>
#include <net/xfrm.h>

#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include "udp_impl.h"

DEFINE_SNMP_STAT(struct udp_mib, udp_stats_in6) __read_mostly;

static inline int udp_v6_get_port(struct sock *sk, unsigned short snum)
{
	return udp_get_port(sk, snum, ipv6_rcv_saddr_equal);
}

static struct sock *__udp6_lib_lookup(struct in6_addr *saddr, __be16 sport,
				      struct in6_addr *daddr, __be16 dport,
				      int dif, struct hlist_head udptable[])
{
	struct sock *sk, *result = NULL;
	struct hlist_node *node;
	unsigned short hnum = ntohs(dport);
	int badness = -1;

	read_lock(&udp_hash_lock);
	sk_for_each(sk, node, &udptable[hnum & (UDP_HTABLE_SIZE - 1)]) {
		struct inet_sock *inet = inet_sk(sk);

		if (sk->sk_hash == hnum && sk->sk_family == PF_INET6) {
			struct ipv6_pinfo *np = inet6_sk(sk);
			int score = 0;
			if (inet->dport) {
				if (inet->dport != sport)
					continue;
				score++;
			}
			if (!ipv6_addr_any(&np->rcv_saddr)) {
				if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
					continue;
				score++;
			}
			if (!ipv6_addr_any(&np->daddr)) {
				if (!ipv6_addr_equal(&np->daddr, saddr))
					continue;
				score++;
			}
			if (sk->sk_bound_dev_if) {
				if (sk->sk_bound_dev_if != dif)
					continue;
				score++;
			}
			if (score == 4) {
				result = sk;
				break;
			} else if (score > badness) {
				result = sk;
				badness = score;
			}
		}
	}
	if (result)
		sock_hold(result);
	read_unlock(&udp_hash_lock);
	return result;
}

/*
 * 	This should be easy, if there is something there we
 * 	return it, otherwise we block.
 */

int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,
		  struct msghdr *msg, size_t len,
		  int noblock, int flags, int *addr_len)
{
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct inet_sock *inet = inet_sk(sk);
	struct sk_buff *skb;
	unsigned int ulen, copied;
	int err;
	int is_udplite = IS_UDPLITE(sk);

	if (addr_len)
		*addr_len=sizeof(struct sockaddr_in6);

	if (flags & MSG_ERRQUEUE)
		return ipv6_recv_error(sk, msg, len);

try_again:
	skb = skb_recv_datagram(sk, flags, noblock, &err);
	if (!skb)
		goto out;

	ulen = skb->len - sizeof(struct udphdr);
	copied = len;
	if (copied > ulen)
		copied = ulen;
	else if (copied < ulen)
		msg->msg_flags |= MSG_TRUNC;

	/*
	 * If checksum is needed at all, try to do it while copying the
	 * data.  If the data is truncated, or if we only want a partial
	 * coverage checksum (UDP-Lite), do it before the copy.
	 */

	if (copied