linux/net/xfrm/xfrm_output.c
Herbert Xu 13996378e6 [IPSEC]: Rename mode to outer_mode and add inner_mode
This patch adds a new field to xfrm states called inner_mode.  The existing
mode object is renamed to outer_mode.

This is the first part of an attempt to fix inter-family transforms.  As it
is we always use the outer family when determining which mode to use.  As a
result we may end up shoving IPv4 packets into netfilter6 and vice versa.

What we really want is to use the inner family for the first part of outbound
processing and the outer family for the second part.  For inbound processing
we'd use the opposite pairing.

I've also added a check to prevent silly combinations such as transport mode
with inter-family transforms.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-17 21:35:51 -07:00

96 lines
2 KiB
C

/*
* xfrm_output.c - Common IPsec encapsulation code.
*
* Copyright (c) 2007 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/errno.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <net/dst.h>
#include <net/xfrm.h>
static int xfrm_state_check_space(struct xfrm_state *x, struct sk_buff *skb)
{
int nhead = x->props.header_len + LL_RESERVED_SPACE(skb->dst->dev)
- skb_headroom(skb);
if (nhead > 0)
return pskb_expand_head(skb, nhead, 0, GFP_ATOMIC);
/* Check tail too... */
return 0;
}
static int xfrm_state_check(struct xfrm_state *x, struct sk_buff *skb)
{
int err = xfrm_state_check_expire(x);
if (err < 0)
goto err;
err = xfrm_state_check_space(x, skb);
err:
return err;
}
int xfrm_output(struct sk_buff *skb)
{
struct dst_entry *dst = skb->dst;
struct xfrm_state *x = dst->xfrm;
int err;
if (skb->ip_summed == CHECKSUM_PARTIAL) {
err = skb_checksum_help(skb);
if (err)
goto error_nolock;
}
do {
spin_lock_bh(&x->lock);
err = xfrm_state_check(x, skb);
if (err)
goto error;
if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
XFRM_SKB_CB(skb)->seq = ++x->replay.oseq;
if (xfrm_aevent_is_on())
xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
}
err = x->outer_mode->output(x, skb);
if (err)
goto error;
x->curlft.bytes += skb->len;
x->curlft.packets++;
spin_unlock_bh(&x->lock);
err = x->type->output(x, skb);
if (err)
goto error_nolock;
if (!(skb->dst = dst_pop(dst))) {
err = -EHOSTUNREACH;
goto error_nolock;
}
dst = skb->dst;
x = dst->xfrm;
} while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL));
err = 0;
error_nolock:
return err;
error:
spin_unlock_bh(&x->lock);
goto error_nolock;
}
EXPORT_SYMBOL_GPL(xfrm_output);