path: root/net/ipv6/ipv6_sockglue.c

/*
 *	IPv6 BSD socket options interface
 *	Linux INET6 implementation 
 *
 *	Authors:
 *	Pedro Roque		<roque@di.fc.ul.pt>	
 *
 *	Based on linux/net/ipv4/ip_sockglue.c
 *
 *	$Id: ipv6_sockglue.c,v 1.41 2002/02/01 22:01:04 davem Exp $
 *
 *	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.
 *
 *	FIXME: Make the setsockopt code POSIX compliant: That is
 *
 *	o	Return -EINVAL for setsockopt of short lengths
 *	o	Truncate getsockopt returns
 *	o	Return an optlen of the truncated length if need be
 *
 *	Changes:
 *	David L Stevens <dlstevens@us.ibm.com>:
 *		- added multicast source filtering API for MLDv2
 */

#include <linux/module.h>
#include <linux/capability.h>
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/sched.h>
#include <linux/net.h>
#include <linux/in6.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/init.h>
#include <linux/sysctl.h>
#include <linux/netfilter.h>

#include <net/sock.h>
#include <net/snmp.h>
#include <net/ipv6.h>
#include <net/ndisc.h>
#include <net/protocol.h>
#include <net/transp_v6.h>
#include <net/ip6_route.h>
#include <net/addrconf.h>
#include <net/inet_common.h>
#include <net/tcp.h>
#include <net/udp.h>
#include <net/xfrm.h>

#include <asm/uaccess.h>

DEFINE_SNMP_STAT(struct ipstats_mib, ipv6_statistics) __read_mostly;

static struct packet_type ipv6_packet_type = {
	.type = __constant_htons(ETH_P_IPV6), 
	.func = ipv6_rcv,
};

struct ip6_ra_chain *ip6_ra_chain;
DEFINE_RWLOCK(ip6_ra_lock);

int ip6_ra_control(struct sock *sk, int sel, void (*destructor)(struct sock *))
{
	struct ip6_ra_chain *ra, *new_ra, **rap;

	/* RA packet may be delivered ONLY to IPPROTO_RAW socket */
	if (sk->sk_type != SOCK_RAW || inet_sk(sk)->num != IPPROTO_RAW)
		return -EINVAL;

	new_ra = (sel>=0) ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;

	write_lock_bh(&ip6_ra_lock);
	for (rap = &ip6_ra_chain; (ra=*rap) != NULL; rap = &ra->next) {
		if (ra->sk == sk) {
			if (sel>=0) {
				write_unlock_bh(&ip6_ra_lock);
				kfree(new_ra);
				return -EADDRINUSE;
			}

			*rap = ra->next;
			write_unlock_bh(&ip6_ra_lock);

			if (ra->destructor)
				ra->destructor(sk);
			sock_put(sk);
			kfree(ra);
			return 0;
		}
	}
	if (new_ra == NULL) {
		write_unlock_bh(&ip6_ra_lock);
		return -ENOBUFS;
	}
	new_ra->sk = sk;
	new_ra->sel = sel;
	new_ra->destructor = destructor;
	new_ra->next = ra;
	*rap = new_ra;
	sock_hold(sk);
	write_unlock_bh(&ip6_ra_lock);
	return 0;
}

static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
		    char __user *optval, int optlen)
{
	struct ipv6_pinfo *np = inet6_sk(sk);
	int val, valbool;
	int retv = -ENOPROTOOPT;

	if (optval == NULL)
		val=0;
	else if (get_user(val, (int __user *) optval))
		return -EFAULT;

	valbool = (val!=0);

	lock_sock(sk);

	switch (optname) {

	case IPV6_ADDRFORM:
		if (val == PF_INET) {
			struct ipv6_txoptions *opt;
			struct sk_buff *pktopt;

			if (sk->sk_protocol != IPPROTO_UDP &&
			    sk->sk_protocol != IPPROTO_TCP)
				break;

			if (sk->sk_state != TCP_ESTABLISHED) {
				retv = -ENOTCONN;
				break;
			}

			if (ipv6_only_sock(sk) ||
			    !(ipv6_addr_type(&np->daddr) & IPV6_ADDR_MAPPED)) {
				retv = -EADDRNOTAVAIL;
				break;
			}

			fl6_free_socklist(sk);
			ipv6_sock_mc_close(sk);

			/*
			 * Sock is moving from IPv6 to IPv4 (sk_prot), so
			 * remove it from the refcnt debug socks count in the
			 * original family...
			 */
			sk_refcnt_debug_dec(sk);

			if (sk->sk_protocol == IPPROTO_TCP) {
				struct inet_connection_sock *icsk = inet_csk(sk);

				local_bh_disable();
				sock_prot_dec_use(sk->sk_prot);
				sock_prot_inc_use(&tcp_prot);
				local_bh_enable();
				sk->sk_prot = &tcp_prot;
				icsk->icsk_af_ops = &ipv4_specific;
				sk->sk_socket->ops = &inet_stream_ops;