From: Mark Mielke <mark.mielke@gmail.com>
Date: Wed, 29 Jul 2020 04:11:28 +0000 (-0400)
Subject: vncserver: Display check should avoid duplicate code
X-Git-Tag: v1.10.90~5^2~3
X-Git-Url: https://source.dussan.org/?a=commitdiff_plain;h=cc362f77987bb32ebeffcb4aa2c7e90b7a8f6914;p=tigervnc.git

vncserver: Display check should avoid duplicate code

The display check had duplicate code to first check if the X11 port is
not in use, and then check that the RFB port is not in use. Eliminate
the duplicate code by using a for-loop.
---

diff --git a/unix/vncserver/vncserver.in b/unix/vncserver/vncserver.in
index 670bcf1b..1b5717e8 100755
--- a/unix/vncserver/vncserver.in
+++ b/unix/vncserver/vncserver.in
@@ -374,21 +374,17 @@ sub CheckDisplayNumber
     my $rfb_port = 5900 + $n;
     my $x11_port = 6000 + $n;
 
-    socket(S, $AF_INET, $SOCK_STREAM, 0) || die "$prog: socket failed: $!\n";
-    eval 'setsockopt(S, &SOL_SOCKET, &SO_REUSEADDR, pack("l", 1))';
-    if (!bind(S, pack('S n x12', $AF_INET, $x11_port))) {
-	close(S);
-	return 0;
-    }
-    close(S);
-
-    socket(S, $AF_INET, $SOCK_STREAM, 0) || die "$prog: socket failed: $!\n";
-    eval 'setsockopt(S, &SOL_SOCKET, &SO_REUSEADDR, pack("l", 1))';
-    if (!bind(S, pack('S n x12', $AF_INET, $rfb_port))) {
-	close(S);
-	return 0;
+    for my $port ($rfb_port, $x11_port) {
+        # Bind to port to confirm it is not in use.
+        socket(S, $AF_INET, $SOCK_STREAM, 0) || die "$prog: socket failed: $!\n";
+        eval 'setsockopt(S, &SOL_SOCKET, &SO_REUSEADDR, pack("l", 1))';
+        if (!bind(S, pack('S n x12', $AF_INET, $port))) {
+            # Port is in use.
+            close(S);
+            return 0;
+        }
+        close(S);
     }
-    close(S);
 
     my $x11_unix_domain = "/tmp/.X11-unix/X$n";