[IPSEC]: Added xfrm_decode_session_reverse and xfrmX_policy_check_reverse
RFC 4301 requires us to relookup ICMP traffic that does not match any
policies using the reverse of its payload. This patch adds the functions
xfrm_decode_session_reverse and xfrmX_policy_check_reverse so we can get
the reverse flow to perform such a lookup.
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_policy.c b/net/ipv6/xfrm6_policy.c
index 181cf91..d26b7dc 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -123,7 +123,7 @@
}
static inline void
-_decode_session6(struct sk_buff *skb, struct flowi *fl)
+_decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse)
{
u16 offset = skb_network_header_len(skb);
struct ipv6hdr *hdr = ipv6_hdr(skb);
@@ -132,8 +132,8 @@
u8 nexthdr = nh[IP6CB(skb)->nhoff];
memset(fl, 0, sizeof(struct flowi));
- ipv6_addr_copy(&fl->fl6_dst, &hdr->daddr);
- ipv6_addr_copy(&fl->fl6_src, &hdr->saddr);
+ ipv6_addr_copy(&fl->fl6_dst, reverse ? &hdr->saddr : &hdr->daddr);
+ ipv6_addr_copy(&fl->fl6_src, reverse ? &hdr->daddr : &hdr->saddr);
while (pskb_may_pull(skb, nh + offset + 1 - skb->data)) {
nh = skb_network_header(skb);
@@ -156,8 +156,8 @@
if (pskb_may_pull(skb, nh + offset + 4 - skb->data)) {
__be16 *ports = (__be16 *)exthdr;
- fl->fl_ip_sport = ports[0];
- fl->fl_ip_dport = ports[1];
+ fl->fl_ip_sport = ports[!!reverse];
+ fl->fl_ip_dport = ports[!reverse];
}
fl->proto = nexthdr;
return;