fwd: Consolidate scans (not rebinds) in fwd.c

fwd_scan_ports_timer(), via the things it calls, goes through all the auto
forwarding cases (tcp, udp, inbound, outbound) and for each one first scans
for listening ports, then rebinds - that is, closes or opens our own
listening ports to match.

Rearrange to do all the scans first, then all the rebinds after.  This lets
us consolidate all the scans into fwd.c, and will enable further cleanups.

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

6 files changed, 31 insertions, 30 deletions

diff --git a/fwd.c b/fwd.c
index 6e248fe..523097b 100644
--- a/fwd.c
+++ b/fwd.c
@@ -365,7 +365,8 @@ static void procfs_scan_listen(int fd, unsigned int lstate,
  * @fwd:	Forwarding information to update
  * @rev:	Forwarding information for the reverse direction
  */
-void fwd_scan_ports_tcp(struct fwd_ports *fwd, const struct fwd_ports *rev)
+static void fwd_scan_ports_tcp(struct fwd_ports *fwd,
+			       const struct fwd_ports *rev)
 {
 	memset(fwd->map, 0, PORT_BITMAP_SIZE);
 	procfs_scan_listen(fwd->scan4, TCP_LISTEN, fwd->map, rev->map);
@@ -379,9 +380,10 @@ void fwd_scan_ports_tcp(struct fwd_ports *fwd, const struct fwd_ports *rev)
  * @tcp_fwd:	Corresponding TCP forwarding information
  * @tcp_rev:	TCP forwarding information for the reverse direction
  */
-void fwd_scan_ports_udp(struct fwd_ports *fwd, const struct fwd_ports *rev,
-			const struct fwd_ports *tcp_fwd,
-			const struct fwd_ports *tcp_rev)
+static void fwd_scan_ports_udp(struct fwd_ports *fwd,
+			       const struct fwd_ports *rev,
+			       const struct fwd_ports *tcp_fwd,
+			       const struct fwd_ports *tcp_rev)
 {
 	uint8_t exclude[PORT_BITMAP_SIZE];
 
@@ -460,10 +462,23 @@ void fwd_scan_ports_timer(struct ctx *c, const struct timespec *now)
 
 	scan_ports_run = *now;
 
+	if (c->tcp.fwd_out.mode == FWD_AUTO)
+		fwd_scan_ports_tcp(&c->tcp.fwd_out, &c->tcp.fwd_in);
+	if (c->tcp.fwd_in.mode == FWD_AUTO)
+		fwd_scan_ports_tcp(&c->tcp.fwd_in, &c->tcp.fwd_out);
+	if (c->udp.fwd_out.mode == FWD_AUTO) {
+		fwd_scan_ports_udp(&c->udp.fwd_out, &c->udp.fwd_in,
+				   &c->tcp.fwd_out, &c->tcp.fwd_in);
+	}
+	if (c->udp.fwd_in.mode == FWD_AUTO) {
+		fwd_scan_ports_udp(&c->udp.fwd_in, &c->udp.fwd_out,
+				   &c->tcp.fwd_in, &c->tcp.fwd_out);
+	}
+
 	if (!c->no_tcp)
-		tcp_scan_ports(c);
+		tcp_port_rebind_all(c);
 	if (!c->no_udp)
-		udp_scan_ports(c);
+		udp_port_rebind_all(c);
 }
 
 /**
diff --git a/fwd.h b/fwd.h
index ec7bb3b..7792582 100644
--- a/fwd.h
+++ b/fwd.h
@@ -44,10 +44,6 @@ struct fwd_ports {
 
 #define FWD_PORT_SCAN_INTERVAL		1000	/* ms */
 
-void fwd_scan_ports_tcp(struct fwd_ports *fwd, const struct fwd_ports *rev);
-void fwd_scan_ports_udp(struct fwd_ports *fwd, const struct fwd_ports *rev,
-			const struct fwd_ports *tcp_fwd,
-			const struct fwd_ports *tcp_rev);
 void fwd_scan_ports_init(struct ctx *c);
 void fwd_scan_ports_timer(struct ctx *c, const struct timespec *now);
 
diff --git a/tcp.c b/tcp.c
index fc1a261..c35c1c3 100644
--- a/tcp.c
+++ b/tcp.c
@@ -2884,22 +2884,18 @@ static int tcp_port_rebind_outbound(void *arg)
 }
 
 /**
- * tcp_scan_ports() - Update forwarding maps based on scan of listening ports
+ * tcp_port_rebind_all() - Rebind ports to match forward maps (in host & ns)
  * @c:		Execution context
  */
-void tcp_scan_ports(struct ctx *c)
+void tcp_port_rebind_all(struct ctx *c)
 {
 	ASSERT(c->mode == MODE_PASTA && !c->no_tcp);
 
-	if (c->tcp.fwd_out.mode == FWD_AUTO) {
-		fwd_scan_ports_tcp(&c->tcp.fwd_out, &c->tcp.fwd_in);
+	if (c->tcp.fwd_out.mode == FWD_AUTO)
 		NS_CALL(tcp_port_rebind_outbound, c);
-	}
 
-	if (c->tcp.fwd_in.mode == FWD_AUTO) {
-		fwd_scan_ports_tcp(&c->tcp.fwd_in, &c->tcp.fwd_out);
+	if (c->tcp.fwd_in.mode == FWD_AUTO)
 		tcp_port_rebind(c, false);
-	}
 }
 
 /**
diff --git a/tcp.h b/tcp.h
index 9cd736d..0082386 100644
--- a/tcp.h
+++ b/tcp.h
@@ -21,7 +21,7 @@ int tcp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af,
 int tcp_sock_init(const struct ctx *c, const union inany_addr *addr,
 		  const char *ifname, in_port_t port);
 int tcp_init(struct ctx *c);
-void tcp_scan_ports(struct ctx *c);
+void tcp_port_rebind_all(struct ctx *c);
 void tcp_timer(const struct ctx *c, const struct timespec *now);
 void tcp_defer_handler(struct ctx *c);
 
diff --git a/udp.c b/udp.c
index d95ef2f..8cff880 100644
--- a/udp.c
+++ b/udp.c
@@ -1252,24 +1252,18 @@ static int udp_port_rebind_outbound(void *arg)
 }
 
 /**
- * udp_scan_ports() - Update forwarding maps based on scan of listening ports
+ * udp_port_rebind_all() - Rebind ports to match forward maps (in host & ns)
  * @c:		Execution context
  */
-void udp_scan_ports(struct ctx *c)
+void udp_port_rebind_all(struct ctx *c)
 {
 	ASSERT(c->mode == MODE_PASTA && !c->no_udp);
 
-	if (c->udp.fwd_out.mode == FWD_AUTO) {
-		fwd_scan_ports_udp(&c->udp.fwd_out, &c->udp.fwd_in,
-				   &c->tcp.fwd_out, &c->tcp.fwd_in);
+	if (c->udp.fwd_out.mode == FWD_AUTO)
 		NS_CALL(udp_port_rebind_outbound, c);
-	}
 
-	if (c->udp.fwd_in.mode == FWD_AUTO) {
-		fwd_scan_ports_udp(&c->udp.fwd_in, &c->udp.fwd_out,
-				   &c->tcp.fwd_in, &c->tcp.fwd_out);
+	if (c->udp.fwd_in.mode == FWD_AUTO)
 		udp_port_rebind(c, false);
-	}
 }
 
 /**
diff --git a/udp.h b/udp.h
index e3fb78b..f1d83f3 100644
--- a/udp.h
+++ b/udp.h
@@ -18,7 +18,7 @@ int udp_tap_handler(const struct ctx *c, uint8_t pif,
 int udp_sock_init(const struct ctx *c, int ns, const union inany_addr *addr,
 		  const char *ifname, in_port_t port);
 int udp_init(struct ctx *c);
-void udp_scan_ports(struct ctx *c);
+void udp_port_rebind_all(struct ctx *c);
 void udp_update_l2_buf(const unsigned char *eth_d);
 
 /**