From 78682c15df5f808ee906010e0107500412b174f0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20Grubbstr=C3=B6m=20=28Grubba=29?=
<grubba@grubba.org>
Date: Wed, 27 Feb 2013 15:12:21 +0100
Subject: [PATCH] Mysql: Potential workaround for race-condition in create().
It seems mysql_real_connect() and/or mysql_close() aren't
fully thread-safe. When there's a high reconnect contention,
create() sometimes failed with ECONNREFUSED. A network scan
of the client could observe that a new connection was closed
by the client before the server had sent its greeting.
The bug has been observed as recently as in MySQL 5.5.30.
---
src/modules/Mysql/mysql.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/src/modules/Mysql/mysql.c b/src/modules/Mysql/mysql.c
index 0e7166fafb..9c12f88636 100644
--- a/src/modules/Mysql/mysql.c
+++ b/src/modules/Mysql/mysql.c
@@ -482,13 +482,13 @@ static void pike_mysql_reconnect (int reconnect)
MYSQL_ALLOW();
+#if defined(HAVE_MYSQL_PORT) || defined(HAVE_MYSQL_UNIX_PORT)
+ STUPID_PORT_LOCK();
+#endif /* HAVE_MYSQL_PORT || HAVE_MYSQL_UNIX_PORT */
#ifdef HAVE_MYSQL_REAL_CONNECT
socket = mysql_real_connect(mysql, host, user, password,
NULL, port, portptr, options);
#else
-#if defined(HAVE_MYSQL_PORT) || defined(HAVE_MYSQL_UNIX_PORT)
- STUPID_PORT_LOCK();
-#endif /* HAVE_MYSQL_PORT || HAVE_MYSQL_UNIX_PORT */
#ifdef HAVE_MYSQL_PORT
if (port) {
@@ -516,10 +516,10 @@ static void pike_mysql_reconnect (int reconnect)
}
#endif /* HAVE_MYSQL_UNIX_PORT */
+#endif /* HAVE_MYSQL_REAL_CONNECT */
#if defined(HAVE_MYSQL_PORT) || defined(HAVE_MYSQL_UNIX_PORT)
STUPID_PORT_UNLOCK();
#endif /* HAVE_MYSQL_PORT || MAVE_MYSQL_UNIX_PORT*/
-#endif /* HAVE_MYSQL_REAL_CONNECT */
MYSQL_DISALLOW();
--
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