ipv6: Consolidate route lookup sequences.

Route lookups follow a general pattern in the ipv6 code wherein
we first find the non-IPSEC route, potentially override the
flow destination address due to ipv6 options settings, and then
finally make an IPSEC search using either xfrm_lookup() or
__xfrm_lookup().

__xfrm_lookup() is used when we want to generate a blackhole route
if the key manager needs to resolve the IPSEC rules (in this case
-EREMOTE is returned and the original 'dst' is left unchanged).

Otherwise plain xfrm_lookup() is used and when asynchronous IPSEC
resolution is necessary, we simply fail the lookup completely.

All of these cases are encapsulated into two routines,
ip6_dst_lookup_flow and ip6_sk_dst_lookup_flow.  The latter of which
handles unconnected UDP datagram sockets.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 12 deletions

diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index 364e86683388..dc29b07caf42 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -856,20 +856,11 @@ static int rawv6_sendmsg(struct kiocb *iocb, struct sock *sk,
                 fl.oif = np->mcast_oif;
         security_sk_classify_flow(sk, &fl);
 
-        err = ip6_dst_lookup(sk, &dst, &fl);
-        if (err)
+        dst = ip6_dst_lookup_flow(sk, &fl, final_p, true);
+        if (IS_ERR(dst)) {
+                err = PTR_ERR(dst);
                 goto out;
-        if (final_p)
-                ipv6_addr_copy(&fl.fl6_dst, final_p);
-
-        err = __xfrm_lookup(sock_net(sk), &dst, &fl, sk, XFRM_LOOKUP_WAIT);
-        if (err < 0) {
-                if (err == -EREMOTE)
-                        err = ip6_dst_blackhole(sk, &dst, &fl);
-                if (err < 0)
-                        goto out;
         }
-
         if (hlimit < 0) {
                 if (ipv6_addr_is_multicast(&fl.fl6_dst))
                         hlimit = np->mcast_hops;