mirror of
https://github.com/torvalds/linux.git
synced 2024-12-27 13:22:23 +00:00
fe833fca2e
When generating the ip header for the transformed packet we just copy
the frag_off field of the ip header from the original packet to the ip
header of the new generated packet. If we receive a packet as a chain
of fragments, all but the last of the new generated packets have the
IP_MF flag set. We have to mask the frag_off field to only keep the
IP_DF flag from the original packet. This got lost with git commit
36cf9acf93 ("[IPSEC]: Separate
inner/outer mode processing on output")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
123 lines
2.9 KiB
C
123 lines
2.9 KiB
C
/*
|
|
* xfrm4_mode_tunnel.c - Tunnel mode encapsulation for IPv4.
|
|
*
|
|
* Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/stringify.h>
|
|
#include <net/dst.h>
|
|
#include <net/inet_ecn.h>
|
|
#include <net/ip.h>
|
|
#include <net/xfrm.h>
|
|
|
|
static inline void ipip_ecn_decapsulate(struct sk_buff *skb)
|
|
{
|
|
struct iphdr *inner_iph = ipip_hdr(skb);
|
|
|
|
if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
|
|
IP_ECN_set_ce(inner_iph);
|
|
}
|
|
|
|
/* Add encapsulation header.
|
|
*
|
|
* The top IP header will be constructed per RFC 2401.
|
|
*/
|
|
static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
|
|
{
|
|
struct dst_entry *dst = skb->dst;
|
|
struct iphdr *top_iph;
|
|
int flags;
|
|
|
|
skb_set_network_header(skb, -x->props.header_len);
|
|
skb->mac_header = skb->network_header +
|
|
offsetof(struct iphdr, protocol);
|
|
skb->transport_header = skb->network_header + sizeof(*top_iph);
|
|
top_iph = ip_hdr(skb);
|
|
|
|
top_iph->ihl = 5;
|
|
top_iph->version = 4;
|
|
|
|
top_iph->protocol = xfrm_af2proto(skb->dst->ops->family);
|
|
|
|
/* DS disclosed */
|
|
top_iph->tos = INET_ECN_encapsulate(XFRM_MODE_SKB_CB(skb)->tos,
|
|
XFRM_MODE_SKB_CB(skb)->tos);
|
|
|
|
flags = x->props.flags;
|
|
if (flags & XFRM_STATE_NOECN)
|
|
IP_ECN_clear(top_iph);
|
|
|
|
top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
|
|
0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF));
|
|
ip_select_ident(top_iph, dst->child, NULL);
|
|
|
|
top_iph->ttl = dst_metric(dst->child, RTAX_HOPLIMIT);
|
|
|
|
top_iph->saddr = x->props.saddr.a4;
|
|
top_iph->daddr = x->id.daddr.a4;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int xfrm4_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
|
|
{
|
|
const unsigned char *old_mac;
|
|
int err = -EINVAL;
|
|
|
|
if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPIP)
|
|
goto out;
|
|
|
|
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
|
|
goto out;
|
|
|
|
if (skb_cloned(skb) &&
|
|
(err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
|
|
goto out;
|
|
|
|
if (x->props.flags & XFRM_STATE_DECAP_DSCP)
|
|
ipv4_copy_dscp(XFRM_MODE_SKB_CB(skb)->tos, ipip_hdr(skb));
|
|
if (!(x->props.flags & XFRM_STATE_NOECN))
|
|
ipip_ecn_decapsulate(skb);
|
|
|
|
old_mac = skb_mac_header(skb);
|
|
skb_set_mac_header(skb, -skb->mac_len);
|
|
memmove(skb_mac_header(skb), old_mac, skb->mac_len);
|
|
skb_reset_network_header(skb);
|
|
err = 0;
|
|
|
|
out:
|
|
return err;
|
|
}
|
|
|
|
static struct xfrm_mode xfrm4_tunnel_mode = {
|
|
.input2 = xfrm4_mode_tunnel_input,
|
|
.input = xfrm_prepare_input,
|
|
.output2 = xfrm4_mode_tunnel_output,
|
|
.output = xfrm4_prepare_output,
|
|
.owner = THIS_MODULE,
|
|
.encap = XFRM_MODE_TUNNEL,
|
|
.flags = XFRM_MODE_FLAG_TUNNEL,
|
|
};
|
|
|
|
static int __init xfrm4_mode_tunnel_init(void)
|
|
{
|
|
return xfrm_register_mode(&xfrm4_tunnel_mode, AF_INET);
|
|
}
|
|
|
|
static void __exit xfrm4_mode_tunnel_exit(void)
|
|
{
|
|
int err;
|
|
|
|
err = xfrm_unregister_mode(&xfrm4_tunnel_mode, AF_INET);
|
|
BUG_ON(err);
|
|
}
|
|
|
|
module_init(xfrm4_mode_tunnel_init);
|
|
module_exit(xfrm4_mode_tunnel_exit);
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_TUNNEL);
|