path: root/net/ipv6/datagram.c

/*
 *	common UDP/RAW code
 *	Linux INET6 implementation
 *
 *	Authors:
 *	Pedro Roque		<roque@di.fc.ul.pt>
 *
 *	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/capability.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/in6.h>
#include <linux/ipv6.h>
#include <linux/route.h>
#include <linux/slab.h>
#include <linux/export.h>

#include <net/ipv6.h>
#include <net/ndisc.h>
#include <net/addrconf.h>
#include <net/transp_v6.h>
#include <net/ip6_route.h>
#include <net/tcp_states.h>
#include <net/dsfield.h>

#include <linux/errqueue.h>
#include <asm/uaccess.h>

static bool ipv6_mapped_addr_any(const struct in6_addr *a)
{
	return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0);
}

int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
{
	struct sockaddr_in6	*usin = (struct sockaddr_in6 *) uaddr;
	struct inet_sock      	*inet = inet_sk(sk);
	struct ipv6_pinfo      	*np = inet6_sk(sk);
	struct in6_addr		*daddr, *final_p, final;
	struct dst_entry	*dst;
	struct flowi6		fl6;
	struct ip6_flowlabel	*flowlabel = NULL;
	struct ipv6_txoptions   *opt;
	int			addr_type;
	int			err;

	if (usin->sin6_family == AF_INET) {
		if (__ipv6_only_sock(sk))
			return -EAFNOSUPPORT;
		err = ip4_datagram_connect(sk, uaddr, addr_len);
		goto ipv4_connected;
	}

	if (addr_len < SIN6_LEN_RFC2133)
		return -EINVAL;

	if (usin->sin6_family != AF_INET6)
		return -EAFNOSUPPORT;

	memset(&fl6, 0, sizeof(fl6));
	if (np->sndflow) {
		fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
		if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
			flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
			if (flowlabel == NULL)
				return -EINVAL;
			usin->sin6_addr = flowlabel->dst;
		}
	}

	addr_type = ipv6_addr_type(&usin->sin6_addr);

	if (addr_type == IPV6_ADDR_ANY) {
		/*
		 *	connect to self
		 */
		usin->sin6_addr.s6_addr[15] = 0x01;
	}

	daddr = &usin->sin6_addr;

	if (addr_type == IPV6_ADDR_MAPPED) {
		struct sockaddr_in sin;

		if (__ipv6_only_sock(sk)) {
			err = -ENETUNREACH;
			goto out;
		}
		sin.sin_family = AF_INET;
		sin.sin_addr.s_addr = daddr->s6_addr32[3];
		sin.sin_port = usin->sin6_port;

		err = ip4_datagram_connect(sk,
					   (struct sockaddr *) &sin,
					   sizeof(sin));

ipv4_connected:
		if (err)
			goto out;

		ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);

		if (ipv6_addr_any(&np->saddr) ||
		    ipv6_mapped_addr_any(&np->saddr))
			ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);

		if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
		    ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
			ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
					       &sk->sk_v6_rcv_saddr);
			if (sk->sk_prot->rehash)
				sk->sk_prot->rehash(sk);
		}

		goto out;
	}

	if (__ipv6_addr_needs_scope_id(addr_type)) {
		if (addr_len >= sizeof(struct sockaddr_in6) &&
		    usin->sin6_scope_id) {
			if (sk->sk_bound_dev_if &&
			    sk->sk_bound_dev_if != usin->sin6_scope_id) {
				err = -EINVAL;
				goto out;
			}
			sk->sk_bound_dev_if = usin->sin6_scope_id;
		}

		if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
			sk->sk_bound_dev_if = np->mcast_oif;

		/* Connect to link-local address requires an interface */
		if (!sk->sk_bound_dev_if) {
			err = -EINVAL;
			goto out;
		}
	}

	sk->sk_v6_daddr = *daddr;
	np->flow_label = fl6.flowlabel;

	inet->inet_dport = usin->sin6_port;

	/*
	 *	Check for a route to destination an obtain the
	 *	destination cache for it.
	 */

	fl6.flowi6_proto = sk->sk_protocol;
	fl6.daddr = sk->sk_v6_daddr;
	fl6.saddr = np->saddr;
	fl6.flowi6_oif = sk->sk_bound_dev_if;
	fl6.flowi6_mark = sk->sk_mark;
	fl6.fl6_dport = inet->inet_dport;
	fl6.fl6_sport