From 4b4b931bcdf23f5facd49809278a3048c4fdba1f Mon Sep 17 00:00:00 2001 From: Andrew Dunstan Date: Mon, 8 Jul 2024 11:18:06 -0400 Subject: [PATCH] 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 0135c5a795..32ee98aebc 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