fwd: Don't explicitly exclude reverse-direction TCP ports for UDP

In auto-forwarding mode, we forward UDP ports for which there isn't (yet)
a listening UDP port on the other side, but where there is a listening
TCP socket for the same port number.  This is useful for certain protocols
such as iperf3.

Correspondinly, when excluding ports from forwarding, we also exclude TCP
ports from the other direction.  That sounds like it makes sense, but is
unnecessary: for the purposes of exclusion, we don't care why we have a
listening UDP socket for that port, just whether we have one.  That is
already incorporated into the UDP bitmap alone.

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

2 files changed, 3 insertions, 4 deletions

diff --git a/fwd.c b/fwd.c
index c7a880e..c417e0f 100644
--- a/fwd.c
+++ b/fwd.c
@@ -410,10 +410,8 @@ static void fwd_scan_ports(struct ctx *c)
 
 	memcpy(excl_tcp_out, c->tcp.fwd_in.map, sizeof(excl_tcp_out));
 	memcpy(excl_tcp_in, c->tcp.fwd_out.map, sizeof(excl_tcp_in));
-	bitmap_or(excl_udp_out, PORT_BITMAP_SIZE,
-		  c->udp.fwd_in.map, c->tcp.fwd_in.map);
-	bitmap_or(excl_udp_in, PORT_BITMAP_SIZE,
-		  c->udp.fwd_out.map, c->tcp.fwd_out.map);
+	memcpy(excl_udp_out, c->udp.fwd_in.map, sizeof(excl_udp_out));
+	memcpy(excl_udp_in, c->udp.fwd_out.map, sizeof(excl_udp_in));
 
 	fwd_scan_ports_tcp(&c->tcp.fwd_out, excl_tcp_out);
 	fwd_scan_ports_tcp(&c->tcp.fwd_in, excl_tcp_in);
diff --git a/util.c b/util.c
index 7944a49..ab23463 100644
--- a/util.c
+++ b/util.c
@@ -338,6 +338,7 @@ bool bitmap_isset(const uint8_t *map, unsigned bit)
  * @a:		First operand
  * @b:		Second operand
  */
+/* cppcheck-suppress unusedFunction */
 void bitmap_or(uint8_t *dst, size_t size, const uint8_t *a, const uint8_t *b)
 {
 	unsigned long *dw = (unsigned long *)dst;