From d171bc3e0d534f97b6f58603dbe27c29d397d894 Mon Sep 17 00:00:00 2001
From: Neil Horman <nhorman@openssl.org>
Date: Tue, 3 Jun 2025 16:02:15 -0400
Subject: [PATCH] Test randomly selected client port for availabilty in
 sslrecords test
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Encountered this error in a pr today:
https://github.com/openssl/openssl/actions/runs/15418713146/job/43387767612

===
Proxy started on port [::1]:56662
Engine "ossltest" set.
Using default temp DH parameters
ACCEPT [::1]:59189
Server responds on [::1]:59189
Engine "ossltest" set.
C0774F02907F0000:error:80000062:system library:BIO_bind:Address already in use:crypto/bio/bio_sock2.c:240:calling bind()
C0774F02907F0000:error:10000075:BIO routines:BIO_bind:unable to bind socket:crypto/bio/bio_sock2.c:242:
connect:errno=98
===

Its occuring because we randomly select a port to use for our client
connection in the sslrecords test.  Thats usually fine, but sometimes,
we get unlucky and pick a port thats already in use.  This presents as
random failures in our CI on this test.

So lets try harden ourselves against it.  When creating the client
connection, test the randomly selected port by trying to bind to it via
a call to IO::Socket::IP->new(). If that fails, try a different port
number, until we get one that works.  If it works, use that port in the
assignment for the clients local port value.

Reviewed-by: Saša Nedvědický <sashan@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/27752)

(cherry picked from commit f78f824c8e4064148af1186490e9b445871765fd)
---
 util/perl/TLSProxy/Proxy.pm | 41 ++++++++++++++++++++++++++++++++++---
 1 file changed, 38 insertions(+), 3 deletions(-)

diff --git a/util/perl/TLSProxy/Proxy.pm b/util/perl/TLSProxy/Proxy.pm
index 0cc5cefe7de..aaba45b029e 100644
--- a/util/perl/TLSProxy/Proxy.pm
+++ b/util/perl/TLSProxy/Proxy.pm
@@ -93,6 +93,7 @@ sub new_dtls {
 
 sub init
 {
+    require IO::Socket::IP;
     my $class = shift;
     my ($filter,
         $execute,
@@ -100,10 +101,44 @@ sub init
         $debug,
         $isdtls) = @_;
 
+    my $test_client_port;
+
+    # Sometimes, our random selection of client ports gets unlucky
+    # And we randomly select a port thats already in use.  This causes
+    # this test to fail, so lets harden ourselves against that by doing
+    # a test bind to the randomly selected port, and only continue once we
+    # find a port thats available.
+    my $test_client_addr = $have_IPv6 ? "[::1]" : "127.0.0.1";
+    my $found_port = 0;
+    for (my $i = 0; $i <= 10; $i++) {
+        $test_client_port = 49152 + int(rand(65535 - 49152));
+        my $test_sock;
+        if ($have_IPv6) {
+            $test_sock = IO::Socket::IP->new(Family => AF_INET6,
+                                             LocalPort => $test_client_port,
+                                             LocalAddr => $test_client_addr);
+        } else {
+            $test_sock = IO::Socket::IP->new(Family => AF_INET,
+                                             LocalPort => $test_client_port,
+                                             LocalAddr => $test_client_addr);
+        }
+        if ($test_sock) {
+            $found_port = 1;
+            $test_sock->close();
+            print "Found available client port ${test_client_port}\n";
+            last;
+        }
+        print "Port ${test_client_port} in use.  Trying again\n";
+    }
+  
+    if ($found_port == 0) {
+        die "Unable to find usable port for TLSProxy";
+    }
+
     my $self = {
         #Public read/write
-        proxy_addr => $have_IPv6 ? "[::1]" : "127.0.0.1",
-        client_addr => $have_IPv6 ? "[::1]" : "127.0.0.1",
+        proxy_addr => $test_client_addr,
+        client_addr => $test_client_addr,
         filter => $filter,
         serverflags => "",
         clientflags => "",
@@ -114,7 +149,7 @@ sub init
         #Public read
         isdtls => $isdtls,
         proxy_port => 0,
-        client_port => 49152 + int(rand(65535 - 49152)),
+        client_port => $test_client_port,
         server_port => 0,
         serverpid => 0,
         clientpid => 0,
-- 
2.47.2