[deliverable/linux.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;
	mtu = dst_mtu(dst);
	if (skb->len > mtu) {
		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;

	return xfrm4_extract_header(skb);
}

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

	err = x->inner_mode->afinfo->extract_output(x, skb);
	if (err)
		return err;

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

	skb->protocol = htons(ETH_P_IP);

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

static inline int xfrm4_output_one(struct sk_buff *skb)
{
	int err;

	err = xfrm_output(skb);
	if (err)
		goto error_nolock;

	IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
	err = 0;

out_exit:
	return err;
error_nolock:
	kfree_skb(skb);
	goto out_exit;
}

static int xfrm4_output_finish2(struct sk_buff *skb)
{
	int err;

	while (likely((err = xfrm4_output_one(skb)) == 0)) {
		nf_reset(skb);

		err = __ip_local_out(skb);
		if (unlikely(err != 1))
			break;

		if (!skb->dst->xfrm)
			return dst_output(skb);

		err = nf_hook(PF_INET, NF_IP_POST_ROUTING, skb, NULL,
			      skb->dst->dev, xfrm4_output_finish2);
		if (unlikely(err != 1))
			break;
	}

	return err;
}

static int xfrm4_output_finish(struct sk_buff *skb)
{
	struct sk_buff *segs;

#ifdef CONFIG_NETFILTER
	if (!skb->dst->xfrm) {
		IPCB(skb)->flags |= IPSKB_REROUTED;
		return dst_output(skb);
	}
#endif

	if (!skb_is_gso(skb))
		return xfrm4_output_finish2(skb);

	skb->protocol = htons(ETH_P_IP);
	segs = skb_gso_segment(skb, 0);
	kfree_skb(skb);
	if (unlikely(IS_ERR(segs)))
		return PTR_ERR(segs);

	do {
		struct sk_buff *nskb = segs->next;
		int err;

		segs->next = NULL;
		err = xfrm4_output_finish2(segs);

		if (unlikely(err)) {
			while ((segs = nskb)) {
				nskb = segs->next;
				segs->next = NULL;
				kfree_skb(segs);
			}
			return err;
		}

		segs = nskb;
	} while (segs);

	return 0;
}

int xfrm4_output(struct sk_buff *skb)
{
	return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, skb->dst->dev,
			    xfrm4_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;
	31
	32	dst = skb->dst;
	33	mtu = dst_mtu(dst);
	34	if (skb->len > mtu) {
	35	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
	36	ret = -EMSGSIZE;
	37	}
	38	out:
	39	return ret;
	40	}
	41
36cf9acf HX	42	int xfrm4_extract_output(struct xfrm_state x, struct sk_buff skb)
	43	{
	44	int err;
	45
	46	err = xfrm4_tunnel_check_size(skb);
	47	if (err)
	48	return err;
	49
	50	return xfrm4_extract_header(skb);
	51	}
	52
	53	int xfrm4_prepare_output(struct xfrm_state x, struct sk_buff skb)
	54	{
	55	int err;
	56
	57	err = x->inner_mode->afinfo->extract_output(x, skb);
	58	if (err)
	59	return err;
	60
	61	memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
	62	IPCB(skb)->flags \|= IPSKB_XFRM_TUNNEL_SIZE;
	63
	64	skb->protocol = htons(ETH_P_IP);
	65
	66	return x->outer_mode->output2(x, skb);
	67	}
	68	EXPORT_SYMBOL(xfrm4_prepare_output);
	69
406ef77c	70	static inline int xfrm4_output_one(struct sk_buff *skb)
1da177e4	71	{
1da177e4	72	int err;
e905a9ed	73
406ef77c HX	74	err = xfrm_output(skb);
	75	if (err)
	76	goto error_nolock;
16a6677f	77
3e3850e9	78	IPCB(skb)->flags \|= IPSKB_XFRM_TRANSFORMED;
16a6677f	79	err = 0;
1da177e4 LT	80
	81	out_exit:
	82	return err;
1da177e4 LT	83	error_nolock:
	84	kfree_skb(skb);
	85	goto out_exit;
	86	}
16a6677f	87
09b8f7a9	88	static int xfrm4_output_finish2(struct sk_buff *skb)
16a6677f PM	89	{
	90	int err;
	91
	92	while (likely((err = xfrm4_output_one(skb)) == 0)) {
	93	nf_reset(skb);
	94
c439cb2e	95	err = __ip_local_out(skb);
16a6677f PM	96	if (unlikely(err != 1))
	97	break;
	98
	99	if (!skb->dst->xfrm)
	100	return dst_output(skb);
	101
3db05fea	102	err = nf_hook(PF_INET, NF_IP_POST_ROUTING, skb, NULL,
09b8f7a9	103	skb->dst->dev, xfrm4_output_finish2);
16a6677f PM	104	if (unlikely(err != 1))
	105	break;
	106	}
	107
	108	return err;
	109	}
	110
09b8f7a9 HX	111	static int xfrm4_output_finish(struct sk_buff *skb)
	112	{
	113	struct sk_buff *segs;
	114
	115	#ifdef CONFIG_NETFILTER
	116	if (!skb->dst->xfrm) {
	117	IPCB(skb)->flags \|= IPSKB_REROUTED;
	118	return dst_output(skb);
	119	}
	120	#endif
	121
89114afd	122	if (!skb_is_gso(skb))
09b8f7a9 HX	123	return xfrm4_output_finish2(skb);
	124
	125	skb->protocol = htons(ETH_P_IP);
	126	segs = skb_gso_segment(skb, 0);
	127	kfree_skb(skb);
	128	if (unlikely(IS_ERR(segs)))
	129	return PTR_ERR(segs);
	130
	131	do {
	132	struct sk_buff *nskb = segs->next;
	133	int err;
	134
	135	segs->next = NULL;
	136	err = xfrm4_output_finish2(segs);
	137
	138	if (unlikely(err)) {
	139	while ((segs = nskb)) {
	140	nskb = segs->next;
	141	segs->next = NULL;
	142	kfree_skb(segs);
	143	}
	144	return err;
	145	}
	146
	147	segs = nskb;
	148	} while (segs);
	149
	150	return 0;
	151	}
	152
16a6677f PM	153	int xfrm4_output(struct sk_buff *skb)
16a6677f PM	154	{
48d5cad8 PM	155	return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, skb->dst->dev,
	156	xfrm4_output_finish,
	157	!(IPCB(skb)->flags & IPSKB_REROUTED));
16a6677f	158	}