[net-next-2.6.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/compiler.h>
#include <linux/if_ether.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/netfilter_ipv4.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;
	struct iphdr *iph = skb->nh.iph;

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

	IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
	
	if (!(iph->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;
}

static int xfrm4_output_one(struct sk_buff *skb)
{
	struct dst_entry *dst = skb->dst;
	struct xfrm_state *x = dst->xfrm;
	int err;
	
	if (skb->ip_summed == CHECKSUM_HW) {
		err = skb_checksum_help(skb, 0);
		if (err)
			goto error_nolock;
	}

	if (x->props.mode) {
		err = xfrm4_tunnel_check_size(skb);
		if (err)
			goto error_nolock;
	}

	do {
		spin_lock_bh(&x->lock);
		err = xfrm_state_check(x, skb);
		if (err)
			goto error;

		err = x->mode->output(skb);
		if (err)
			goto error;

		err = x->type->output(x, skb);
		if (err)
			goto error;

		x->curlft.bytes += skb->len;
		x->curlft.packets++;

		spin_unlock_bh(&x->lock);
	
		if (!(skb->dst = dst_pop(dst))) {
			err = -EHOSTUNREACH;
			goto error_nolock;
		}
		dst = skb->dst;
		x = dst->xfrm;
	} while (x && !x->props.mode);

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

out_exit:
	return err;
error:
	spin_unlock_bh(&x->lock);
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 = nf_hook(PF_INET, NF_IP_LOCAL_OUT, &skb, NULL,
			      skb->dst->dev, dst_output);
		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>
	4	*
	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
16a6677f	11	#include <linux/compiler.h>
09b8f7a9 HX	12	#include <linux/if_ether.h>
09b8f7a9 HX	13	#include <linux/kernel.h>
1da177e4 LT	14	#include <linux/skbuff.h>
1da177e4 LT	15	#include <linux/spinlock.h>
16a6677f	16	#include <linux/netfilter_ipv4.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;
	25	struct iphdr *iph = skb->nh.iph;
	26
	27	if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE)
	28	goto out;
	29
	30	IPCB(skb)->flags \|= IPSKB_XFRM_TUNNEL_SIZE;
	31
	32	if (!(iph->frag_off & htons(IP_DF)) \|\| skb->local_df)
	33	goto out;
	34
	35	dst = skb->dst;
	36	mtu = dst_mtu(dst);
	37	if (skb->len > mtu) {
	38	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
	39	ret = -EMSGSIZE;
	40	}
	41	out:
	42	return ret;
	43	}
	44
16a6677f	45	static int xfrm4_output_one(struct sk_buff *skb)
1da177e4 LT	46	{
	47	struct dst_entry *dst = skb->dst;
	48	struct xfrm_state *x = dst->xfrm;
	49	int err;
	50
	51	if (skb->ip_summed == CHECKSUM_HW) {
	52	err = skb_checksum_help(skb, 0);
	53	if (err)
	54	goto error_nolock;
	55	}
	56
	57	if (x->props.mode) {
	58	err = xfrm4_tunnel_check_size(skb);
	59	if (err)
	60	goto error_nolock;
	61	}
	62
16a6677f PM	63	do {
	64	spin_lock_bh(&x->lock);
	65	err = xfrm_state_check(x, skb);
	66	if (err)
	67	goto error;
1da177e4	68
b59f45d0 HX	69	err = x->mode->output(skb);
	70	if (err)
	71	goto error;
1da177e4	72
16a6677f PM	73	err = x->type->output(x, skb);
	74	if (err)
	75	goto error;
1da177e4	76
16a6677f PM	77	x->curlft.bytes += skb->len;
16a6677f PM	78	x->curlft.packets++;
1da177e4	79
16a6677f	80	spin_unlock_bh(&x->lock);
1da177e4	81
16a6677f PM	82	if (!(skb->dst = dst_pop(dst))) {
	83	err = -EHOSTUNREACH;
	84	goto error_nolock;
	85	}
	86	dst = skb->dst;
	87	x = dst->xfrm;
	88	} while (x && !x->props.mode);
	89
3e3850e9	90	IPCB(skb)->flags \|= IPSKB_XFRM_TRANSFORMED;
16a6677f	91	err = 0;
1da177e4 LT	92
	93	out_exit:
	94	return err;
	95	error:
	96	spin_unlock_bh(&x->lock);
	97	error_nolock:
	98	kfree_skb(skb);
	99	goto out_exit;
	100	}
16a6677f	101
09b8f7a9	102	static int xfrm4_output_finish2(struct sk_buff *skb)
16a6677f PM	103	{
	104	int err;
	105
	106	while (likely((err = xfrm4_output_one(skb)) == 0)) {
	107	nf_reset(skb);
	108
	109	err = nf_hook(PF_INET, NF_IP_LOCAL_OUT, &skb, NULL,
	110	skb->dst->dev, dst_output);
	111	if (unlikely(err != 1))
	112	break;
	113
	114	if (!skb->dst->xfrm)
	115	return dst_output(skb);
	116
	117	err = nf_hook(PF_INET, NF_IP_POST_ROUTING, &skb, NULL,
09b8f7a9	118	skb->dst->dev, xfrm4_output_finish2);
16a6677f PM	119	if (unlikely(err != 1))
	120	break;
	121	}
	122
	123	return err;
	124	}
	125
09b8f7a9 HX	126	static int xfrm4_output_finish(struct sk_buff *skb)
	127	{
	128	struct sk_buff *segs;
	129
	130	#ifdef CONFIG_NETFILTER
	131	if (!skb->dst->xfrm) {
	132	IPCB(skb)->flags \|= IPSKB_REROUTED;
	133	return dst_output(skb);
	134	}
	135	#endif
	136
89114afd	137	if (!skb_is_gso(skb))
09b8f7a9 HX	138	return xfrm4_output_finish2(skb);
	139
	140	skb->protocol = htons(ETH_P_IP);
	141	segs = skb_gso_segment(skb, 0);
	142	kfree_skb(skb);
	143	if (unlikely(IS_ERR(segs)))
	144	return PTR_ERR(segs);
	145
	146	do {
	147	struct sk_buff *nskb = segs->next;
	148	int err;
	149
	150	segs->next = NULL;
	151	err = xfrm4_output_finish2(segs);
	152
	153	if (unlikely(err)) {
	154	while ((segs = nskb)) {
	155	nskb = segs->next;
	156	segs->next = NULL;
	157	kfree_skb(segs);
	158	}
	159	return err;
	160	}
	161
	162	segs = nskb;
	163	} while (segs);
	164
	165	return 0;
	166	}
	167
16a6677f PM	168	int xfrm4_output(struct sk_buff *skb)
16a6677f PM	169	{
48d5cad8 PM	170	return NF_HOOK_COND(PF_INET, NF_IP_POST_ROUTING, skb, NULL, skb->dst->dev,
	171	xfrm4_output_finish,
	172	!(IPCB(skb)->flags & IPSKB_REROUTED));
16a6677f	173	}