[deliverable/linux.git] / net / ipv6 / xfrm6_output.c

/*
 * xfrm6_output.c - Common IPsec encapsulation code for IPv6.
 * Copyright (C) 2002 USAGI/WIDE Project
 * Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * 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/if_ether.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/icmpv6.h>
#include <linux/netfilter_ipv6.h>
#include <net/dst.h>
#include <net/ipv6.h>
#include <net/ip6_route.h>
#include <net/xfrm.h>

int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
			  u8 **prevhdr)
{
	return ip6_find_1stfragopt(skb, prevhdr);
}

EXPORT_SYMBOL(xfrm6_find_1stfragopt);

static int xfrm6_local_dontfrag(struct sk_buff *skb)
{
	int proto;
	struct sock *sk = skb->sk;

	if (sk) {
		if (sk->sk_family != AF_INET6)
			return 0;

		proto = sk->sk_protocol;
		if (proto == IPPROTO_UDP || proto == IPPROTO_RAW)
			return inet6_sk(sk)->dontfrag;
	}

	return 0;
}

static void xfrm6_local_rxpmtu(struct sk_buff *skb, u32 mtu)
{
	struct flowi6 fl6;
	struct sock *sk = skb->sk;

	fl6.flowi6_oif = sk->sk_bound_dev_if;
	fl6.daddr = ipv6_hdr(skb)->daddr;

	ipv6_local_rxpmtu(sk, &fl6, mtu);
}

void xfrm6_local_error(struct sk_buff *skb, u32 mtu)
{
	struct flowi6 fl6;
	const struct ipv6hdr *hdr;
	struct sock *sk = skb->sk;

	hdr = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(skb);
	fl6.fl6_dport = inet_sk(sk)->inet_dport;
	fl6.daddr = hdr->daddr;

	ipv6_local_error(sk, EMSGSIZE, &fl6, mtu);
}

static int xfrm6_tunnel_check_size(struct sk_buff *skb)
{
	int mtu, ret = 0;
	struct dst_entry *dst = skb_dst(skb);

	mtu = dst_mtu(dst);
	if (mtu < IPV6_MIN_MTU)
		mtu = IPV6_MIN_MTU;

	if (!skb->local_df && skb->len > mtu) {
		skb->dev = dst->dev;

		if (xfrm6_local_dontfrag(skb))
			xfrm6_local_rxpmtu(skb, mtu);
		else if (skb->sk)
			xfrm_local_error(skb, mtu);
		else
			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
		ret = -EMSGSIZE;
	}

	return ret;
}

int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb)
{
	int err;

	err = xfrm6_tunnel_check_size(skb);
	if (err)
		return err;

	XFRM_MODE_SKB_CB(skb)->protocol = ipv6_hdr(skb)->nexthdr;

	return xfrm6_extract_header(skb);
}

int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
{
	int err;

	err = xfrm_inner_extract_output(x, skb);
	if (err)
		return err;

	memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
#ifdef CONFIG_NETFILTER
	IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
#endif

	skb->protocol = htons(ETH_P_IPV6);
	skb->local_df = 1;

	return x->outer_mode->output2(x, skb);
}
EXPORT_SYMBOL(xfrm6_prepare_output);

int xfrm6_output_finish(struct sk_buff *skb)
{
#ifdef CONFIG_NETFILTER
	IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
#endif

	skb->protocol = htons(ETH_P_IPV6);
	return xfrm_output(skb);
}

static int __xfrm6_output(struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	struct xfrm_state *x = dst->xfrm;
	int mtu;

	if (skb->protocol == htons(ETH_P_IPV6))
		mtu = ip6_skb_dst_mtu(skb);
	else
		mtu = dst_mtu(skb_dst(skb));

	if (skb->len > mtu && xfrm6_local_dontfrag(skb)) {
		xfrm6_local_rxpmtu(skb, mtu);
		return -EMSGSIZE;
	} else if (!skb->local_df && skb->len > mtu && skb->sk) {
		xfrm_local_error(skb, mtu);
		return -EMSGSIZE;
	}

	if (x->props.mode == XFRM_MODE_TUNNEL &&
	    ((skb->len > mtu && !skb_is_gso(skb)) ||
		dst_allfrag(skb_dst(skb)))) {
			return ip6_fragment(skb, x->outer_mode->afinfo->output_finish);
	}
	return x->outer_mode->afinfo->output_finish(skb);
}

int xfrm6_output(struct sk_buff *skb)
{
	return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL,
		       skb_dst(skb)->dev, __xfrm6_output);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* xfrm6_output.c - Common IPsec encapsulation code for IPv6.
	3	* Copyright (C) 2002 USAGI/WIDE Project
	4	* Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
1ab1457c	5	*
1da177e4 LT	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the License, or (at your option) any later version.
	10	*/
	11
406ef77c	12	#include <linux/if_ether.h>
36cf9acf HX	13	#include <linux/kernel.h>
36cf9acf HX	14	#include <linux/module.h>
1da177e4	15	#include <linux/skbuff.h>
1da177e4	16	#include <linux/icmpv6.h>
16a6677f	17	#include <linux/netfilter_ipv6.h>
36cf9acf	18	#include <net/dst.h>
1da177e4	19	#include <net/ipv6.h>
ad0081e4	20	#include <net/ip6_route.h>
1da177e4 LT	21	#include <net/xfrm.h>
1da177e4 LT	22
aee5adb4 MN	23	int xfrm6_find_1stfragopt(struct xfrm_state x, struct sk_buff skb,
	24	u8 **prevhdr)
	25	{
	26	return ip6_find_1stfragopt(skb, prevhdr);
	27	}
	28
7159039a YH	29	EXPORT_SYMBOL(xfrm6_find_1stfragopt);
7159039a YH	30
dd767856 SK	31	static int xfrm6_local_dontfrag(struct sk_buff *skb)
	32	{
	33	int proto;
	34	struct sock *sk = skb->sk;
	35
	36	if (sk) {
628e341f HFS	37	if (sk->sk_family != AF_INET6)
628e341f HFS	38	return 0;
dd767856	39
628e341f	40	proto = sk->sk_protocol;
dd767856 SK	41	if (proto == IPPROTO_UDP \|\| proto == IPPROTO_RAW)
	42	return inet6_sk(sk)->dontfrag;
	43	}
	44
	45	return 0;
	46	}
	47
	48	static void xfrm6_local_rxpmtu(struct sk_buff *skb, u32 mtu)
	49	{
	50	struct flowi6 fl6;
	51	struct sock *sk = skb->sk;
	52
	53	fl6.flowi6_oif = sk->sk_bound_dev_if;
4e3fd7a0	54	fl6.daddr = ipv6_hdr(skb)->daddr;
dd767856 SK	55
	56	ipv6_local_rxpmtu(sk, &fl6, mtu);
	57	}
	58
628e341f	59	void xfrm6_local_error(struct sk_buff *skb, u32 mtu)
dd767856 SK	60	{
dd767856 SK	61	struct flowi6 fl6;
5d0ff542	62	const struct ipv6hdr *hdr;
dd767856 SK	63	struct sock *sk = skb->sk;
dd767856 SK	64
5d0ff542	65	hdr = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(skb);
dd767856	66	fl6.fl6_dport = inet_sk(sk)->inet_dport;
5d0ff542	67	fl6.daddr = hdr->daddr;
dd767856 SK	68
	69	ipv6_local_error(sk, EMSGSIZE, &fl6, mtu);
	70	}
	71
1da177e4 LT	72	static int xfrm6_tunnel_check_size(struct sk_buff *skb)
	73	{
	74	int mtu, ret = 0;
adf30907	75	struct dst_entry *dst = skb_dst(skb);
1da177e4 LT	76
	77	mtu = dst_mtu(dst);
	78	if (mtu < IPV6_MIN_MTU)
	79	mtu = IPV6_MIN_MTU;
	80
28a89453	81	if (!skb->local_df && skb->len > mtu) {
180e4250	82	skb->dev = dst->dev;
dd767856 SK	83
	84	if (xfrm6_local_dontfrag(skb))
	85	xfrm6_local_rxpmtu(skb, mtu);
	86	else if (skb->sk)
628e341f	87	xfrm_local_error(skb, mtu);
dd767856 SK	88	else
dd767856 SK	89	icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1da177e4 LT	90	ret = -EMSGSIZE;
	91	}
	92
	93	return ret;
	94	}
	95
36cf9acf HX	96	int xfrm6_extract_output(struct xfrm_state x, struct sk_buff skb)
	97	{
	98	int err;
	99
	100	err = xfrm6_tunnel_check_size(skb);
	101	if (err)
	102	return err;
	103
60d5fcfb HX	104	XFRM_MODE_SKB_CB(skb)->protocol = ipv6_hdr(skb)->nexthdr;
60d5fcfb HX	105
36cf9acf HX	106	return xfrm6_extract_header(skb);
	107	}
	108
	109	int xfrm6_prepare_output(struct xfrm_state x, struct sk_buff skb)
	110	{
	111	int err;
	112
df9dcb45	113	err = xfrm_inner_extract_output(x, skb);
36cf9acf HX	114	if (err)
	115	return err;
	116
	117	memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
862b82c6 HX	118	#ifdef CONFIG_NETFILTER
	119	IP6CB(skb)->flags \|= IP6SKB_XFRM_TRANSFORMED;
	120	#endif
36cf9acf HX	121
36cf9acf HX	122	skb->protocol = htons(ETH_P_IPV6);
d1d88e5d	123	skb->local_df = 1;
36cf9acf HX	124
	125	return x->outer_mode->output2(x, skb);
	126	}
	127	EXPORT_SYMBOL(xfrm6_prepare_output);
	128
43a4dea4	129	int xfrm6_output_finish(struct sk_buff *skb)
09b8f7a9	130	{
862b82c6 HX	131	#ifdef CONFIG_NETFILTER
	132	IP6CB(skb)->flags \|= IP6SKB_XFRM_TRANSFORMED;
	133	#endif
09b8f7a9	134
679e898a	135	skb->protocol = htons(ETH_P_IPV6);
862b82c6	136	return xfrm_output(skb);
09b8f7a9 HX	137	}
09b8f7a9 HX	138
ad0081e4 DS	139	static int __xfrm6_output(struct sk_buff *skb)
	140	{
	141	struct dst_entry *dst = skb_dst(skb);
	142	struct xfrm_state *x = dst->xfrm;
5a25cf1e	143	int mtu;
0ea9d5e3	144
5a25cf1e HFS	145	if (skb->protocol == htons(ETH_P_IPV6))
	146	mtu = ip6_skb_dst_mtu(skb);
	147	else
	148	mtu = dst_mtu(skb_dst(skb));
dd767856 SK	149
	150	if (skb->len > mtu && xfrm6_local_dontfrag(skb)) {
	151	xfrm6_local_rxpmtu(skb, mtu);
	152	return -EMSGSIZE;
	153	} else if (!skb->local_df && skb->len > mtu && skb->sk) {
628e341f	154	xfrm_local_error(skb, mtu);
dd767856 SK	155	return -EMSGSIZE;
dd767856 SK	156	}
ad0081e4	157
5b11b2e4	158	if (x->props.mode == XFRM_MODE_TUNNEL &&
dd767856	159	((skb->len > mtu && !skb_is_gso(skb)) \|\|
ad0081e4	160	dst_allfrag(skb_dst(skb)))) {
43a4dea4	161	return ip6_fragment(skb, x->outer_mode->afinfo->output_finish);
ad0081e4	162	}
43a4dea4	163	return x->outer_mode->afinfo->output_finish(skb);
ad0081e4 DS	164	}
ad0081e4 DS	165
16a6677f PM	166	int xfrm6_output(struct sk_buff *skb)
16a6677f PM	167	{
b2e0b385	168	return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL,
ad0081e4	169	skb_dst(skb)->dev, __xfrm6_output);
16a6677f	170	}