Bug#12873214 WINDOWS AUTHENTICATION PLUGIN PRODUCES EXCESSIVE RECORDS IN SERVER ERROR LOG

Changed semantics of AUTHENTICATION_WIN_LOG environment variable recognized by client library to accept the following values which are levels of logging done during Windows authentication handshake:
      
  0 - no logging
  1 - log only error messages
  2 - additionally log warnings
  3 - additionally log info notes
  4 - also log debug messages
      
Setting it to 'on', 'yes' or 'true' will request log level 2 and setting it to 'debug' or 'dbug' will request log level 4.

libmysql/authentication_win/common.cc

@@ -22,6 +22,24 @@ template <> void error_log_print<error_log_level::INFO>(const char *fmt, ...);
 template <> void error_log_print<error_log_level::WARNING>(const char *fmt, ...);
 template <> void error_log_print<error_log_level::ERROR>(const char *fmt, ...);
 
+/**
+  Option indicating desired level of logging. Values:
+
+  0 - no logging
+  1 - log only error messages
+  2 - additionally log warnings
+  3 - additionally log info notes
+  4 - also log debug messages
+
+  Value of this option should be taken into account in the 
+  implementation of  error_log_vprint() function (see 
+  log_client.cc).
+
+  Note: No error or debug messages are logged in production code
+  (see logging macros in common.h).
+*/
+int opt_auth_win_log_level= 2;
+
 
 /** Connection class **************************************************/
 

libmysql/authentication_win/common.h

@@ -41,13 +41,15 @@ struct error_log_level
   typedef enum {INFO, WARNING, ERROR}  type;
 };
 
+extern "C" int opt_auth_win_log_level;
+unsigned int  get_log_level(void);
+void          set_log_level(unsigned int);
+
 
 /*
   If DEBUG_ERROR_LOG is defined then error logging happens only
   in debug-copiled code. Otherwise ERROR_LOG() expands to 
-  error_log_print() even in production code. Note that in client
-  plugin, error_log_print() will print nothing if opt_auth_win_clinet_log
-  is 0.
+  error_log_print() even in production code.
 
   Note: Macro ERROR_LOG() can use printf-like format string like this:
 
@@ -57,8 +59,6 @@ struct error_log_level
   to fprintf() (see error_log_vprint() function).
 */
 
-extern "C" int opt_auth_win_client_log;
-
 #if defined(DEBUG_ERROR_LOG) && defined(DBUG_OFF)
 #define ERROR_LOG(Level, Msg)     do {} while (0)
 #else
@@ -67,7 +67,7 @@ extern "C" int opt_auth_win_client_log;
 
 
 void error_log_vprint(error_log_level::type level,
-                        const char *fmt, va_list args);
+                      const char *fmt, va_list args);
 
 template <error_log_level::type Level>
 void error_log_print(const char *fmt, ...)
@@ -96,7 +96,7 @@ const char* get_last_error_message(Error_message_buf);
 
 #define DBUG_PRINT_DO(Keyword, Msg) \
   do { \
-    if (2 > opt_auth_win_client_log) break; \
+    if (4 > get_log_level()) break; \
     fprintf(stderr, "winauth: %s: ", Keyword); \
     debug_msg Msg; \
   } while (0)

libmysql/authentication_win/handshake_client.cc

@@ -323,13 +323,13 @@ int win_auth_handshake_client(MYSQL_PLUGIN_VIO *vio, MYSQL *mysql)
     int opt_val= opt ? atoi(opt) : 0;
     if (opt && !opt_val)
     {
-      if (!strncasecmp("on", opt, 2))    opt_val= 1;
-      if (!strncasecmp("yes", opt, 3))   opt_val= 1;
-      if (!strncasecmp("true", opt, 4))  opt_val= 1;
-      if (!strncasecmp("debug", opt, 5)) opt_val= 2;
-      if (!strncasecmp("dbug", opt, 4))  opt_val= 2;
+      if (!strncasecmp("on", opt, 2))    opt_val= 2;
+      if (!strncasecmp("yes", opt, 3))   opt_val= 2;
+      if (!strncasecmp("true", opt, 4))  opt_val= 2;
+      if (!strncasecmp("debug", opt, 5)) opt_val= 4;
+      if (!strncasecmp("dbug", opt, 4))  opt_val= 4;
     }
-    opt_auth_win_client_log= opt_val;
+    set_log_level(opt_val);
   }
 
   ERROR_LOG(INFO, ("Authentication handshake for account %s", mysql->user));

libmysql/authentication_win/log_client.cc

@@ -16,36 +16,32 @@
 #include <my_global.h>
 #include "common.h"
 
-/**
-  This option is set in win_auth_handshake_client() function 
-  in handshake_client.cc.
-
-  Values:
-  0 - no logging
-  1 - log error/warning/info messages
-  2 - also log debug messages
-
-  Note: No error or debug messages are logged in production code
-  (see logging macros in common.h).
-*/
-int opt_auth_win_client_log= 0;
-
 
 // Client-side logging function
 
 void error_log_vprint(error_log_level::type level,
                         const char *fmt, va_list args)
 {
-  if (0 == opt_auth_win_client_log)
-    return;
-
   const char *level_string= "";
+  int   log_level= get_log_level();
 
   switch (level)
   {
-  case error_log_level::INFO:    level_string= "Note"; break;
-  case error_log_level::WARNING: level_string= "Warning"; break;
-  case error_log_level::ERROR:   level_string= "ERROR"; break;
+  case error_log_level::INFO:    
+    if (3 > log_level)
+      return;
+    level_string= "Note"; 
+    break;
+  case error_log_level::WARNING: 
+    if (2 > log_level)
+      return;
+    level_string= "Warning"; 
+    break;
+  case error_log_level::ERROR:   
+    if (1 > log_level)
+      return;
+    level_string= "ERROR";
+    break;
   }
 
   fprintf(stderr, "Windows Authentication Plugin %s: ", level_string);
@@ -53,3 +49,17 @@ void error_log_vprint(error_log_level::type level,
   fputc('\n', stderr);
   fflush(stderr);
 }
+
+
+// Trivial implementation of log-level setting storage.
+
+void set_log_level(unsigned int level)
+{
+  opt_auth_win_log_level= level;
+}
+
+
+unsigned int  get_log_level(void)
+{
+  return opt_auth_win_log_level;
+}