path: root/net/dccp/ipv6.c

/*
 *	DCCP over IPv6
 *	Linux INET6 implementation
 *
 *	Based on net/dccp6/ipv6.c
 *
 *	Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
 *
 *	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/random.h>
#include <linux/xfrm.h>

#include <net/addrconf.h>
#include <net/inet_common.h>
#include <net/inet_hashtables.h>
#include <net/inet_sock.h>
#include <net/inet6_connection_sock.h>
#include <net/inet6_hashtables.h>
#include <net/ip6_route.h>
#include <net/ipv6.h>
#include <net/protocol.h>
#include <net/transp_v6.h>
#include <net/ip6_checksum.h>
#include <net/xfrm.h>

#include "dccp.h"
#include "ipv6.h"

/* Socket used for sending RSTs and ACKs */
static struct socket *dccp_v6_ctl_socket;

static void dccp_v6_ctl_send_reset(struct sk_buff *skb);
static void dccp_v6_reqsk_send_ack(struct sk_buff *skb,
				   struct request_sock *req);
static void dccp_v6_send_check(struct sock *sk, int len, struct sk_buff *skb);

static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);

static struct inet_connection_sock_af_ops dccp_ipv6_mapped;
static struct inet_connection_sock_af_ops dccp_ipv6_af_ops;

static int dccp_v6_get_port(struct sock *sk, unsigned short snum)
{
	return inet_csk_get_port(&dccp_hashinfo, sk, snum,
				 inet6_csk_bind_conflict);
}

static void dccp_v6_hash(struct sock *sk)
{
	if (sk->sk_state != DCCP_CLOSED) {
		if (inet_csk(sk)->icsk_af_ops == &dccp_ipv6_mapped) {
			dccp_hash(sk);
			return;
		}
		local_bh_disable();
		__inet6_hash(&dccp_hashinfo, sk);
		local_bh_enable();
	}
}

static inline u16 dccp_v6_check(struct dccp_hdr *dh, int len,
				struct in6_addr *saddr,
				struct in6_addr *daddr,
				unsigned long base)
{
	return csum_ipv6_magic(saddr, daddr, len, IPPROTO_DCCP, base);
}

static __u32 dccp_v6_init_sequence(struct sock *sk, struct sk_buff *skb)
{
	const struct dccp_hdr *dh = dccp_hdr(skb);

	if (skb->protocol == htons(ETH_P_IPV6))
		return secure_tcpv6_sequence_number(skb->nh.ipv6h->daddr.s6_addr32,
						    skb->nh.ipv6h->saddr.s6_addr32,
						    dh->dccph_dport,
						    dh->dccph_sport);

	return secure_dccp_sequence_number(skb->nh.iph->daddr,
					   skb->nh.iph->saddr,
					   dh->dccph_dport,
					   dh->dccph_sport);
}

static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
			   int addr_len)
{
	struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr;
	struct inet_connection_sock *icsk = inet_csk(sk);
	struct inet_sock *inet = inet_sk(sk);
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct dccp_sock *dp = dccp_sk(sk);
	struct in6_addr *saddr = NULL, *final_p = NULL, final;
	struct flowi fl;
	struct dst_entry *dst;
	int addr_type;
	int err;

	dp->dccps_role = DCCP_ROLE_CLIENT;

	if (addr_len < SIN6_LEN_RFC2133)
		return -EINVAL;

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

	memset(&fl, 0, sizeof(fl));

	if (np->sndflow) {
		fl.fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
		IP6_ECN_flow_init(fl.fl6_flowlabel);
		if (fl.fl6_flowlabel & IPV6_FLOWLABEL_MASK) {
			struct ip6_flowlabel *flowlabel;
			flowlabel = fl6_sock_lookup(sk, fl.fl6_flowlabel);
			if (flowlabel == NULL)
				return -EINVAL;
			ipv6_addr_copy(&usin->sin6_addr, &flowlabel->dst);
			fl6_sock_release(flowlabel);
		}
	}
	/*
	 * connect() to INADDR_ANY means loopback (BSD'ism).
	 */
	if (ipv6_addr_any(&usin->sin6_addr))
		usin->sin6_addr.s6_addr[15] = 1;

	addr_type = ipv6_addr_type(&usin->sin6_addr);

	if (addr_type & IPV6_ADDR_MULTICAST)
		return -ENETUNREACH;

	if (addr_type & IPV6_ADDR_LINKLOCAL) {
		if (addr_len >= sizeof(struct sockaddr_in6) &&
		    usin->sin6_scope_id) {
			/* If interface is set while binding, indices
			 * must coincide.
			 */
			if (sk->sk_bound_dev_if &&
			    sk->sk_bound_dev_if != usin->sin6_scope_id)
				return -EINVAL;

			sk->sk_bound_dev_if = usin->sin6_scope_id;
		}

		/* Connect to link-local address requires an interface */
		if (!sk->sk_bound_dev_if)
			return -EINVAL;
	}

	ipv6_addr_copy(&np->daddr, &usin->sin6_addr);
	np->flow_label = fl.fl6_flowlabel;

	/*
	 * DCCP over IPv4
	 */
	if (addr_type == IPV6_ADDR_MAPPED) {
		u32 exthdrlen = icsk->icsk_ext_hdr_len;
		struct sockaddr_in sin;

		SOCK_DEBUG(sk, "connect: ipv4 mapped\n");

		if (__ipv6_only_sock(sk))
			return -ENETUNREACH;<