tcp, udp: Don't pre-fill IPv4 destination address in headers

Because packets sent on the tap interface will always be going to the
guest/namespace, we more-or-less know what address they'll be going to.  So
we pre-fill this destination address in our header buffers for IPv4.  We
can't do the same for IPv6 because we could need either the global or
link-local address for the guest.  In future we're going to want more
flexibility for the destination address, so this pre-filling will get in
the way.

Change the flow so we always fill in the IPv4 destination address for each
packet, rather than prefilling it from proto_update_l2_buf().  In fact for
TCP we already redundantly filled the destination for each packet anyway.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/passt.h b/passt.h
index 0500ff0..282bd1a 100644
--- a/passt.h
+++ b/passt.h
@@ -303,7 +303,7 @@ struct ctx {
 	int low_rmem;
 };
 
-void proto_update_l2_buf(const unsigned char *eth_d, const unsigned char *eth_s,
-			 const struct in_addr *ip_da);
+void proto_update_l2_buf(const unsigned char *eth_d,
+			 const unsigned char *eth_s);
 
 #endif /* PASST_H */