180e425033
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
145 lines
3.5 KiB
C
145 lines
3.5 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/skbuff.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/icmpv6.h>
|
|
#include <net/dsfield.h>
|
|
#include <net/inet_ecn.h>
|
|
#include <net/ipv6.h>
|
|
#include <net/xfrm.h>
|
|
|
|
/* Add encapsulation header.
|
|
*
|
|
* In transport mode, the IP header and mutable extension headers will be moved
|
|
* forward to make space for the encapsulation header.
|
|
*
|
|
* In tunnel mode, the top IP header will be constructed per RFC 2401.
|
|
* The following fields in it shall be filled in by x->type->output:
|
|
* payload_len
|
|
*
|
|
* On exit, skb->h will be set to the start of the encapsulation header to be
|
|
* filled in by x->type->output and skb->nh will be set to the nextheader field
|
|
* of the extension header directly preceding the encapsulation header, or in
|
|
* its absence, that of the top IP header. The value of skb->data will always
|
|
* point to the top IP header.
|
|
*/
|
|
static void xfrm6_encap(struct sk_buff *skb)
|
|
{
|
|
struct dst_entry *dst = skb->dst;
|
|
struct xfrm_state *x = dst->xfrm;
|
|
struct ipv6hdr *iph, *top_iph;
|
|
int dsfield;
|
|
|
|
skb_push(skb, x->props.header_len);
|
|
iph = skb->nh.ipv6h;
|
|
|
|
if (!x->props.mode) {
|
|
u8 *prevhdr;
|
|
int hdr_len;
|
|
|
|
hdr_len = ip6_find_1stfragopt(skb, &prevhdr);
|
|
skb->nh.raw = prevhdr - x->props.header_len;
|
|
skb->h.raw = skb->data + hdr_len;
|
|
memmove(skb->data, iph, hdr_len);
|
|
return;
|
|
}
|
|
|
|
skb->nh.raw = skb->data;
|
|
top_iph = skb->nh.ipv6h;
|
|
skb->nh.raw = &top_iph->nexthdr;
|
|
skb->h.ipv6h = top_iph + 1;
|
|
|
|
top_iph->version = 6;
|
|
top_iph->priority = iph->priority;
|
|
top_iph->flow_lbl[0] = iph->flow_lbl[0];
|
|
top_iph->flow_lbl[1] = iph->flow_lbl[1];
|
|
top_iph->flow_lbl[2] = iph->flow_lbl[2];
|
|
dsfield = ipv6_get_dsfield(top_iph);
|
|
dsfield = INET_ECN_encapsulate(dsfield, dsfield);
|
|
if (x->props.flags & XFRM_STATE_NOECN)
|
|
dsfield &= ~INET_ECN_MASK;
|
|
ipv6_change_dsfield(top_iph, 0, dsfield);
|
|
top_iph->nexthdr = IPPROTO_IPV6;
|
|
top_iph->hop_limit = dst_metric(dst->child, RTAX_HOPLIMIT);
|
|
ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
|
|
ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
int xfrm6_output(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 = xfrm6_tunnel_check_size(skb);
|
|
if (err)
|
|
goto error_nolock;
|
|
}
|
|
|
|
spin_lock_bh(&x->lock);
|
|
err = xfrm_state_check(x, skb);
|
|
if (err)
|
|
goto error;
|
|
|
|
xfrm6_encap(skb);
|
|
|
|
err = x->type->output(x, skb);
|
|
if (err)
|
|
goto error;
|
|
|
|
x->curlft.bytes += skb->len;
|
|
x->curlft.packets++;
|
|
|
|
spin_unlock_bh(&x->lock);
|
|
|
|
skb->nh.raw = skb->data;
|
|
|
|
if (!(skb->dst = dst_pop(dst))) {
|
|
err = -EHOSTUNREACH;
|
|
goto error_nolock;
|
|
}
|
|
err = NET_XMIT_BYPASS;
|
|
|
|
out_exit:
|
|
return err;
|
|
error:
|
|
spin_unlock_bh(&x->lock);
|
|
error_nolock:
|
|
kfree_skb(skb);
|
|
goto out_exit;
|
|
}
|