[IPSEC] xfrm: Abstract out encapsulation modes
This patch adds the structure xfrm_mode. It is meant to represent
the operations carried out by transport/tunnel modes.
By doing this we allow additional encapsulation modes to be added
without clogging up the xfrm_input/xfrm_output paths.
Candidate modes include 4-to-6 tunnel mode, 6-to-4 tunnel mode, and
BEET modes.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
index 8024217..16e8425 100644
--- a/net/ipv6/xfrm6_output.c
+++ b/net/ipv6/xfrm6_output.c
@@ -14,68 +14,9 @@
#include <linux/spinlock.h>
#include <linux/icmpv6.h>
#include <linux/netfilter_ipv6.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;
@@ -118,7 +59,9 @@
if (err)
goto error;
- xfrm6_encap(skb);
+ err = x->mode->output(skb);
+ if (err)
+ goto error;
err = x->type->output(x, skb);
if (err)