fwd, conf: Expose ephemeral ports as bitmap rather than function

It turns out the only callers of fwd_port_is_ephemeral() use it to build a
bitmap of ephemeral ports.  So, replace it with fwd_port_map_ephemeral(),
which directly builds that bitmap.  As a bonus this allows a slightly
cheaper implementation of building the map, since inside fwd.c we know that
the ephemeral ports form a single range.

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

3 files changed, 10 insertions, 15 deletions

diff --git a/conf.c b/conf.c
index 6ca61b7..7a3085b 100644
--- a/conf.c
+++ b/conf.c
@@ -282,9 +282,7 @@ static void conf_ports(const struct ctx *c, char optname, const char *optarg,
 		*mode = FWD_MODE_ALL;
 
 		/* Exclude ephemeral ports */
-		for (i = 0; i < NUM_PORTS; i++)
-			if (fwd_port_is_ephemeral(i))
-				bitmap_set(exclude, i);
+		fwd_port_map_ephemeral(exclude);
 
 		conf_ports_range_except(c, optname, optarg, fwd,
 					NULL, NULL,
@@ -376,9 +374,7 @@ static void conf_ports(const struct ctx *c, char optname, const char *optarg,
 
 	if (exclude_only) {
 		/* Exclude ephemeral ports */
-		for (i = 0; i < NUM_PORTS; i++)
-			if (fwd_port_is_ephemeral(i))
-				bitmap_set(exclude, i);
+		fwd_port_map_ephemeral(exclude);
 
 		conf_ports_range_except(c, optname, optarg, fwd,
 					addr, ifname,
diff --git a/fwd.c b/fwd.c
index 03652b2..62d344c 100644
--- a/fwd.c
+++ b/fwd.c
@@ -319,16 +319,15 @@ static const union inany_addr *fwd_rule_addr(const struct fwd_rule *rule)
 }
 
 /**
- * fwd_port_is_ephemeral() - Is port number ephemeral?
- * @port:	Port number
- *
- * Return: true if @port is ephemeral, that is may be allocated by the kernel as
- *         a local port for outgoing connections or datagrams, but should not be
- *         used for binding services to.
+ * fwd_port_map_ephemeral() - Mark ephemeral ports in a bitmap
+ * @map:	Bitmap to update
  */
-bool fwd_port_is_ephemeral(in_port_t port)
+void fwd_port_map_ephemeral(uint8_t *map)
 {
-	return (port >= fwd_ephemeral_min) && (port <= fwd_ephemeral_max);
+	unsigned port;
+
+	for (port = fwd_ephemeral_min; port <= fwd_ephemeral_max; port++)
+		bitmap_set(map, port);
 }
 
 /* Forwarding table storage, generally accessed via pointers in struct ctx */
diff --git a/fwd.h b/fwd.h
index b387d92..f111e13 100644
--- a/fwd.h
+++ b/fwd.h
@@ -22,7 +22,7 @@ struct flowside;
 #define	NUM_PORTS	(1U << 16)
 
 void fwd_probe_ephemeral(void);
-bool fwd_port_is_ephemeral(in_port_t port);
+void fwd_port_map_ephemeral(uint8_t *map);
 
 /**
  * struct fwd_rule - Forwarding rule governing a range of ports