linux/net/ipv6/xfrm6_output.c
Herbert Xu ceb1eec829 [IPSEC]: Move IP length/checksum setting out of transforms
This patch moves the setting of the IP length and checksum fields out of
the transforms and into the xfrmX_output functions.  This would help future
efforts in merging the transforms themselves.

It also adds an optimisation to ipcomp due to the fact that the transport
offset is guaranteed to be zero.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:55:56 -07:00

139 lines
2.8 KiB
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/compiler.h>
#include <linux/skbuff.h>
#include <linux/icmpv6.h>
#include <linux/netfilter_ipv6.h>
#include <net/ipv6.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_tunnel_check_size(struct sk_buff *skb)
{
int mtu, ret = 0;
struct dst_entry *dst = skb->dst;
mtu = dst_mtu(dst);
if (mtu < IPV6_MIN_MTU)
mtu = IPV6_MIN_MTU;
if (skb->len > mtu) {
skb->dev = dst->dev;
icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, skb->dev);
ret = -EMSGSIZE;
}
return ret;
}
static inline int xfrm6_output_one(struct sk_buff *skb)
{
struct dst_entry *dst = skb->dst;
struct xfrm_state *x = dst->xfrm;
struct ipv6hdr *iph;
int err;
if (x->props.mode == XFRM_MODE_TUNNEL) {
err = xfrm6_tunnel_check_size(skb);
if (err)
goto error_nolock;
}
err = xfrm_output(skb);
if (err)
goto error_nolock;
iph = ipv6_hdr(skb);
iph->payload_len = htons(skb->len - sizeof(*iph));
IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
err = 0;
out_exit:
return err;
error_nolock:
kfree_skb(skb);
goto out_exit;
}
static int xfrm6_output_finish2(struct sk_buff *skb)
{
int err;
while (likely((err = xfrm6_output_one(skb)) == 0)) {
nf_reset(skb);
err = nf_hook(PF_INET6, NF_IP6_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_INET6, NF_IP6_POST_ROUTING, &skb, NULL,
skb->dst->dev, xfrm6_output_finish2);
if (unlikely(err != 1))
break;
}
return err;
}
static int xfrm6_output_finish(struct sk_buff *skb)
{
struct sk_buff *segs;
if (!skb_is_gso(skb))
return xfrm6_output_finish2(skb);
skb->protocol = htons(ETH_P_IPV6);
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 = xfrm6_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 xfrm6_output(struct sk_buff *skb)
{
return NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, skb, NULL, skb->dst->dev,
xfrm6_output_finish);
}