postgres.git / summary / log / commit / refs

commit    4b4b931bcdf23f5facd49809278a3048c4fdba1f
Author:   Andrew Dunstan <andrew@dunslane.net>
Date:     Mon Jul 08 15:18:06 2024 +0000
First released in: 18.0, 12.20, 13.16, 14.13, 15.8, 16.4, 17.0

    Choose ports for test servers less likely to result in conflicts
    
    If we choose ports in the range typically used for ephemeral ports there
    is a danger of encountering a port conflict due to a race condition
    between the time we choose the port in a range below that typically used
    to allocate ephemeral ports, but higher than the range typically used by
    well known services.
    
    Author: Jelte Fenema-Nio, with some editing by me.
    
    Discussion: https://postgr.es/m/d6ee8761-39d1-0033-1afb-d5a57ee056f2@gmail.com
    
    Backpatch to all live branches (12 and up)


 src/test/perl/PostgreSQL/Test/Cluster.pm | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/test/perl/PostgreSQL/Test/Cluster.pm b/src/test/perl/PostgreSQL/Test/Cluster.pm
index 0135c5a795c..32ee98aebcc 100644
--- a/src/test/perl/PostgreSQL/Test/Cluster.pm
+++ b/src/test/perl/PostgreSQL/Test/Cluster.pm
@@ -125,6 +125,14 @@ our $min_compat = 12;
 # list of file reservations made by get_free_port
 my @port_reservation_files;
 
+# We want to choose a server port above the range that servers typically use
+# on Unix systems and below the range those systems typically use for ephemeral
+# client ports.
+# That way we minimize the risk of getting a port collision. These two values
+# are chosen to reflect that. We will always choose a port in this range.
+my $port_lower_bound = 10200;
+my $port_upper_bound = 32767;
+
 INIT
 {
 
@@ -149,7 +157,8 @@ INIT
 	$ENV{PGDATABASE} = 'postgres';
 
 	# Tracking of last port value assigned to accelerate free port lookup.
-	$last_port_assigned = int(rand() * 16384) + 49152;
+	my $num_ports = $port_upper_bound - $port_lower_bound;
+	$last_port_assigned = int(rand() * $num_ports) + $port_lower_bound;
 
 	# Set the port lock directory
 
@@ -1692,7 +1701,7 @@ sub get_free_port
 	{
 
 		# advance $port, wrapping correctly around range end
-		$port = 49152 if ++$port >= 65536;
+		$port = $port_lower_bound if ++$port > $port_upper_bound;
 		print "# Checking port $port\n";
 
 		# Check first that candidate port number is not included in


[parent: e4f4c5424cf9]