runtests: spread out the port numbers used by servers

The server ports are chosen randomly for each server, but the random
ranges chosen were inconsistently-sized and overlapping. Now, they are
spread out more so at least the first random port chosen for each server
is guaranteed to not also be chosen by another server. The starting port
numbers are also raised to put them in the Ephemeral Port range—not the
range defined by RFC 6335 but the one used by Linux, which starts lower
and gives us more room to work with.

Reported-by: Daniel Stenberg

1 files changed, 29 insertions, 21 deletions

diff --git a/tests/servers.pm b/tests/servers.pm
index ae0e1cd2c..fce537efb 100644
--- a/tests/servers.pm
+++ b/tests/servers.pm
@@ -118,11 +118,16 @@ my $server_response_maxtime=13;
 my $httptlssrv = find_httptlssrv();
 my %run;          # running server
 my %runcert;      # cert file currently in use by an ssl running server
-my $serverstartretries=10; # number of times to attempt to start server
 my $CLIENTIP="127.0.0.1";  # address which curl uses for incoming connections
 my $CLIENT6IP="[::1]";     # address which curl uses for incoming connections
 my $posix_pwd=$pwd;        # current working directory
 my $h2cver = "h2c"; # this version is decided by the nghttp2 lib being used
+my $serverstartretries=10; # number of times to attempt to start server;
+                           # don't increase without making sure generated port
+                           # numbers will always be valid (<=65535)
+my $portrange = 999;       # space from which to choose a random port
+                           # don't increase without making sure generated port
+                           # numbers will always be valid (<=65535)
 
 # Variables shared with runtests.pl
 our $HOSTIP="127.0.0.1";   # address on which the test server listens
@@ -1200,12 +1205,12 @@ sub runhttp2server {
     $flags .= $verbose_flag if($debugprotocol);
 
     my ($http2pid, $pid2);
-    my $port = 23113;
-    my $port2 = 23114;
+    my $port = 32813;
+    my $port2 = 32814;
     my %usedports = reverse %PORT;
     for(1 .. $serverstartretries) {
-        $port += 1 + int(rand(900));
-        $port2 += 1 + int(rand(900));
+        $port += 1 + int(rand($portrange));
+        $port2 += 1 + int(rand($portrange));
         next if exists $usedports{$port} || $usedports{$port2};
         my $aflags = "--port $port --port2 $port2 $flags";
 
@@ -1272,10 +1277,10 @@ sub runhttp3server {
     $flags .= $verbose_flag if($debugprotocol);
 
     my ($http3pid, $pid3);
-    my $port = 24113;
+    my $port = 33813;
     my %usedports = reverse %PORT;
     for(1 .. $serverstartretries) {
-        $port += 1 + int(rand(900));
+        $port += 1 + int(rand($portrange));
         next if exists $usedports{$port};
         my $aflags = "--port $port $flags";
 
@@ -1360,10 +1365,10 @@ sub runhttpsserver {
 
     my $pid2;
     my $httpspid;
-    my $port = 24512; # start attempt
+    my $port = 34813;
     my %usedports = reverse %PORT;
     for (1 .. $serverstartretries) {
-        $port += 1 + int(rand(600));
+        $port += 1 + int(rand($portrange));
         next if exists $usedports{$port};
         my $options = "$flags --accept $port";
 
@@ -1431,11 +1436,11 @@ sub runhttptlsserver {
     $flags .= "--srppasswd $srcdir/certs/srp-verifier-db ";
     $flags .= "--srppasswdconf $srcdir/certs/srp-verifier-conf";
 
-    my $port = 24367;
+    my $port = 35813;
     my %usedports = reverse %PORT;
     my ($httptlspid, $pid2);
     for (1 .. $serverstartretries) {
-        $port += 1 + int(rand(800));
+        $port += 1 + int(rand($portrange));
         next if exists $usedports{$port};
         my $allflags = "--port $port $flags";
 
@@ -1583,10 +1588,13 @@ sub runsecureserver {
 
     my $protospid;
     my $pid2;
-    my $port = 26713 + ord $proto;
+    # this calculation happens to be a perfect hash function for spreading
+    # out the port ranges for the 4 possible protocols (at the time of this
+    # writing) that will be used here
+    my $port = 36813 + 1000 * ((ord $proto) % 4);
     my %usedports = reverse %PORT;
     for (1 .. $serverstartretries) {
-        $port += 1 + int(rand(700));
+        $port += 1 + int(rand($portrange));
         next if exists $usedports{$port};
         my $options = "$flags --accept $port";
 
@@ -1777,7 +1785,6 @@ sub runsshserver {
     my $proto = 'ssh';
     my $ipvnum = 4;
     my $idnum = ($id && ($id =~ /^(\d+)$/) && ($id > 1)) ? $id : 1;
-    my $port = 20000; # no lower port
 
     if(!$USER) {
         logmsg "Can't start ssh server due to lack of USER name";
@@ -1821,12 +1828,13 @@ sub runsshserver {
 
     my $wport = 0,
     my @tports;
+    my $port = 40813;
     my %usedports = reverse %PORT;
     for(1 .. $serverstartretries) {
         # sshd doesn't have a way to pick an unused random port number, so
         # instead we iterate over possible port numbers to use until we find
         # one that works
-        $port += 1 + int(rand(500));
+        $port += 1 + int(rand($portrange));
         next if exists $usedports{$port};
         push @tports, $port;
 
@@ -2071,11 +2079,11 @@ sub rundictserver {
     $flags .= "--srcdir \"$srcdir\" ";
     $flags .= "--host $HOSTIP";
 
-    my $port = 29000;
+    my $port = 41813;
     my %usedports = reverse %PORT;
     my ($dictpid, $pid2);
     for(1 .. $serverstartretries) {
-        $port += 1 + int(rand(900));
+        $port += 1 + int(rand($portrange));
         next if exists $usedports{$port};
         my $aflags = "--port $port $flags";
         my $cmd = "$srcdir/dictserver.py $aflags";
@@ -2140,10 +2148,10 @@ sub runsmbserver {
     $flags .= "--host $HOSTIP";
 
     my ($smbpid, $pid2);
-    my $port = 31923;
+    my $port = 42813;
     my %usedports = reverse %PORT;
     for(1 .. $serverstartretries) {
-        $port += 1 + int(rand(760));
+        $port += 1 + int(rand($portrange));
         next if exists $usedports{$port};
         my $aflags = "--port $port $flags";
         my $cmd = "$srcdir/smbserver.py $aflags";
@@ -2207,10 +2215,10 @@ sub runnegtelnetserver {
     $flags .= "--srcdir \"$srcdir\"";
 
     my ($ntelpid, $pid2);
-    my $port = 32000;
+    my $port = 43813;
     my %usedports = reverse %PORT;
     for(1 .. $serverstartretries) {
-        $port += 1 + int(rand(800));
+        $port += 1 + int(rand($portrange));
         next if exists $usedports{$port};
         my $aflags = "--port $port $flags";
         my $cmd = "$srcdir/negtelnetserver.py $aflags";