[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / ipv4 / xfrm4_output.c

/*
 * xfrm4_output.c - Common IPsec encapsulation code for IPv4.
 * 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/netfilter_ipv4.h>
#include <net/dst.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/icmp.h>

static int xfrm4_tunnel_check_size(struct sk_buff *skb)
{
	int mtu, ret = 0;
	struct dst_entry *dst;

	if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE)
		goto out;

	if (!(ip_hdr(skb)->frag_off & htons(IP_DF)) || skb->local_df)
		goto out;

	dst = skb_dst(skb);
	mtu = dst_mtu(dst);
	if (skb->len > mtu) {
		if (skb->sk)
			ip_local_error(skb->sk, EMSGSIZE, ip_hdr(skb)->daddr,
				       inet_sk(skb->sk)->inet_dport, mtu);
		else
			icmp_send(skb, ICMP_DEST_UNREACH,
				  ICMP_FRAG_NEEDED, htonl(mtu));
		ret = -EMSGSIZE;
	}
out:
	return ret;
}

int xfrm4_extract_output(struct xfrm_state *x, struct sk_buff *skb)
{
	int err;

	err = xfrm4_tunnel_check_size(skb);
	if (err)
		return err;

	XFRM_MODE_SKB_CB(skb)->protocol = ip_hdr(skb)->protocol;

	return xfrm4_extract_header(skb);
}

int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
{
	int err;

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

	memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
	IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED;

	skb->protocol = htons(ETH_P_IP);

	return x->outer_mode->output2(x, skb);
}
EXPORT_SYMBOL(xfrm4_prepare_output);

int xfrm4_output_finish(struct sk_buff *skb)
{
#ifdef CONFIG_NETFILTER
	if (!skb_dst(skb)->xfrm) {
		IPCB(skb)->flags |= IPSKB_REROUTED;
		return dst_output(skb);
	}

	IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
#endif

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

int xfrm4_output(struct sk_buff *skb)
{
	struct dst_entry *dst = skb_dst(skb);
	struct xfrm_state *x = dst->xfrm;

	return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, skb,
			    NULL, dst->dev,
			    x->outer_mode->afinfo->output_finish,
			    !(IPCB(skb)->flags & IPSKB_REROUTED));
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* xfrm4_output.c - Common IPsec encapsulation code for IPv4.
	3	* Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
e905a9ed	4	*
1da177e4 LT	5	* This program is free software; you can redistribute it and/or
	6	* modify it under the terms of the GNU General Public License
	7	* as published by the Free Software Foundation; either version
	8	* 2 of the License, or (at your option) any later version.
	9	*/
	10
09b8f7a9 HX	11	#include <linux/if_ether.h>
09b8f7a9 HX	12	#include <linux/kernel.h>
36cf9acf	13	#include <linux/module.h>
1da177e4	14	#include <linux/skbuff.h>
16a6677f	15	#include <linux/netfilter_ipv4.h>
36cf9acf	16	#include <net/dst.h>
1da177e4 LT	17	#include <net/ip.h>
	18	#include <net/xfrm.h>
	19	#include <net/icmp.h>
	20
1da177e4 LT	21	static int xfrm4_tunnel_check_size(struct sk_buff *skb)
	22	{
	23	int mtu, ret = 0;
	24	struct dst_entry *dst;
1da177e4 LT	25
	26	if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE)
	27	goto out;
	28
eddc9ec5	29	if (!(ip_hdr(skb)->frag_off & htons(IP_DF)) \|\| skb->local_df)
1da177e4 LT	30	goto out;
1da177e4 LT	31
adf30907	32	dst = skb_dst(skb);
1da177e4 LT	33	mtu = dst_mtu(dst);
1da177e4 LT	34	if (skb->len > mtu) {
b00897b8 SK	35	if (skb->sk)
	36	ip_local_error(skb->sk, EMSGSIZE, ip_hdr(skb)->daddr,
	37	inet_sk(skb->sk)->inet_dport, mtu);
	38	else
	39	icmp_send(skb, ICMP_DEST_UNREACH,
	40	ICMP_FRAG_NEEDED, htonl(mtu));
1da177e4 LT	41	ret = -EMSGSIZE;
	42	}
	43	out:
	44	return ret;
	45	}
	46
36cf9acf HX	47	int xfrm4_extract_output(struct xfrm_state x, struct sk_buff skb)
	48	{
	49	int err;
	50
	51	err = xfrm4_tunnel_check_size(skb);
	52	if (err)
	53	return err;
	54
60d5fcfb HX	55	XFRM_MODE_SKB_CB(skb)->protocol = ip_hdr(skb)->protocol;
60d5fcfb HX	56
36cf9acf HX	57	return xfrm4_extract_header(skb);
	58	}
	59
	60	int xfrm4_prepare_output(struct xfrm_state x, struct sk_buff skb)
	61	{
	62	int err;
	63
df9dcb45	64	err = xfrm_inner_extract_output(x, skb);
36cf9acf HX	65	if (err)
	66	return err;
	67
	68	memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
862b82c6	69	IPCB(skb)->flags \|= IPSKB_XFRM_TUNNEL_SIZE \| IPSKB_XFRM_TRANSFORMED;
36cf9acf HX	70
	71	skb->protocol = htons(ETH_P_IP);
	72
	73	return x->outer_mode->output2(x, skb);
	74	}
	75	EXPORT_SYMBOL(xfrm4_prepare_output);
	76
43a4dea4	77	int xfrm4_output_finish(struct sk_buff *skb)
09b8f7a9	78	{
09b8f7a9	79	#ifdef CONFIG_NETFILTER
adf30907	80	if (!skb_dst(skb)->xfrm) {
09b8f7a9 HX	81	IPCB(skb)->flags \|= IPSKB_REROUTED;
	82	return dst_output(skb);
	83	}
09b8f7a9	84
862b82c6 HX	85	IPCB(skb)->flags \|= IPSKB_XFRM_TRANSFORMED;
862b82c6 HX	86	#endif
09b8f7a9 HX	87
09b8f7a9 HX	88	skb->protocol = htons(ETH_P_IP);
862b82c6	89	return xfrm_output(skb);
09b8f7a9 HX	90	}
09b8f7a9 HX	91
16a6677f PM	92	int xfrm4_output(struct sk_buff *skb)
16a6677f PM	93	{
43a4dea4 SK	94	struct dst_entry *dst = skb_dst(skb);
	95	struct xfrm_state *x = dst->xfrm;
	96
9bbc768a	97	return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, skb,
43a4dea4 SK	98	NULL, dst->dev,
43a4dea4 SK	99	x->outer_mode->afinfo->output_finish,
48d5cad8	100	!(IPCB(skb)->flags & IPSKB_REROUTED));
16a6677f	101	}