MDEV-13921 Audit log writes invalid SQL if single-line comments are

present.

        Escape special characters (like \r \n \t) instead of
        replacing them with spaces.

1 files changed, 21 insertions, 18 deletions

diff --git a/plugin/server_audit/server_audit.c b/plugin/server_audit/server_audit.c
index ad2a4618514..dc8475cf280 100644
--- a/plugin/server_audit/server_audit.c
+++ b/plugin/server_audit/server_audit.c
@@ -1122,6 +1122,21 @@ do { \
 } while(0)
 
 
+#define ESC_MAP_SIZE 0x60
+static const char esc_map[ESC_MAP_SIZE]=
+{
+  0, 0, 0, 0, 0, 0, 0, 0, 'b', 't', 'n', 0, 'f', 'r', 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, '\'', 0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, '\\', 0, 0, 0
+};
+
+static char escaped_char(char c)
+{
+  return ((unsigned char ) c) >= ESC_MAP_SIZE ? 0 : esc_map[(unsigned char) c];
+}
 
 
 static void setup_connection_initdb(struct connection_info *cn,
@@ -1328,21 +1343,16 @@ static size_t escape_string(const char *str, unsigned int len,
   const char *res_end= result + result_len - 2;
   while (len)
   {
+    char esc_c;
+
     if (result >= res_end)
       break;
-    if (*str == '\'')
+    if ((esc_c= escaped_char(*str)))
     {
       if (result+1 >= res_end)
         break;
       *(result++)= '\\';
-      *(result++)= '\'';
-    }
-    else if (*str == '\\')
-    {
-      if (result+1 >= res_end)
-        break;
-      *(result++)= '\\';
-      *(result++)= '\\';
+      *(result++)= esc_c;
     }
     else if (is_space(*str))
       *(result++)= ' ';
@@ -1431,19 +1441,12 @@ static size_t escape_string_hide_passwords(const char *str, unsigned int len,
 no_password:
     if (result >= res_end)
       break;
-    if (*str == '\'')
-    {
-      if (result+1 >= res_end)
-        break;
-      *(result++)= '\\';
-      *(result++)= '\'';
-    }
-    else if (*str == '\\')
+    if ((b_char= escaped_char(*str)))
     {
       if (result+1 >= res_end)
         break;
       *(result++)= '\\';
-      *(result++)= '\\';
+      *(result++)= b_char;
     }
     else if (is_space(*str))
       *(result++)= ' ';