Merge branch '2.2' into 2.2-mrm

Documentation/Changelog.md

@@ -23,6 +23,7 @@
 * Binlog router supports MariaDB 10 GTID at both ends.
 * KILL CONNECTION can now be used through MaxScale.
 * Environment variables can now be used in the MaxScale configuration file.
+* By default, MaxScale can no longer be run as root.
 
 For more details, please refer to:
 * [MariaDB MaxScale 2.2.0 Release Notes](Release-Notes/MaxScale-2.2.0-Release-Notes.md)

Documentation/Release-Notes/MaxScale-2.2.1-Release-Notes.md

@@ -10,6 +10,21 @@ report at [Jira](https://jira.mariadb.org).
 
 ## Changed Features
 
+### Process identity
+
+By default, MaxScale can no longer be run as `root`, but must be run as some
+other user. However, it is possible to start MaxScale as `root`, as long as
+the user to run MaxScale as is provided as a command line argument:
+```
+root@host:~# maxscale --user=maxuser ...
+```
+If it is imperative to run MaxScale as root, e.g. in a Docker container, it
+can be achieved by invoking MaxScale as root and by explicitly specifying
+the user to also be root:
+```
+root@host:~# maxscale --user=root ...
+```
+
 ### Binlog server
 
 * The `mariadb10_slave_gtid` parameter was removed and slave connections can now

server/core/gateway.cc

@@ -107,6 +107,7 @@ const char *progname = NULL;
 static struct option long_options[] =
 {
     {"config-check",     no_argument,       0, 'c'},
+    {"daemon",           no_argument,       0, 'n'},
     {"nodaemon",         no_argument,       0, 'd'},
     {"config",           required_argument, 0, 'f'},
     {"log",              required_argument, 0, 'l'},
@@ -186,6 +187,7 @@ static void modules_process_finish();
 static void disable_module_unloading(const char* arg);
 static void enable_module_unloading(const char* arg);
 static void redirect_output_to_file(const char* arg);
+static bool user_is_acceptable(const char* specified_user);
 
 struct DEBUG_ARGUMENT
 {
@@ -1367,6 +1369,7 @@ int main(int argc, char **argv)
     int numlocks = 0;
     bool pid_file_created = false;
     Worker* worker;
+    const char* specified_user = NULL;
 
     config_set_global_defaults();
     MXS_CONFIG* cnf = config_get_global_options();
@@ -1382,7 +1385,7 @@ int main(int argc, char **argv)
     file_write_header(stderr);
 
     // Option string for getopt
-    const char accepted_opts[] = "dcf:g:l:vVs:S:?L:D:C:B:U:A:P:G:N:E:F:M:H:p";
+    const char accepted_opts[] = "dncf:g:l:vVs:S:?L:D:C:B:U:A:P:G:N:E:F:M:H:p";
 
     /*<
      * Register functions which are called at exit.
@@ -1411,8 +1414,13 @@ int main(int argc, char **argv)
 
         switch (opt)
         {
+        case 'n':
+            /*< Daemon mode, MaxScale forks and parent exits. */
+            daemon_mode = true;
+            break;
+
         case 'd':
-            /*< Debug mode, maxscale runs in this same process */
+            /*< Non-daemon mode, MaxScale does not fork. */
             daemon_mode = false;
             break;
 
@@ -1653,7 +1661,8 @@ int main(int argc, char **argv)
             }
             break;
         case 'U':
-            if (set_user(optarg) != 0)
+            specified_user = optarg;
+            if (set_user(specified_user) != 0)
             {
                 succp = false;
             }
@@ -1694,6 +1703,13 @@ int main(int argc, char **argv)
         }
     }
 
+    if (!user_is_acceptable(specified_user))
+    {
+        // Error was logged in user_is_acceptable().
+        rc = MAXSCALE_INTERNALERROR;
+        goto return_main;
+    }
+
     if (config_check)
     {
         daemon_mode = false;
@@ -3204,3 +3220,41 @@ static bool handle_debug_args(char* args)
     }
     return !arg_error;
 }
+
+static bool user_is_acceptable(const char* specified_user)
+{
+    bool acceptable = false;
+
+    // This is very early, so we do not have logging available, but write to stderr.
+    // As this is security related, we want to do as little as possible.
+
+    uid_t uid = getuid(); // Always succeeds
+    errno = 0;
+    struct passwd *pw = getpwuid(uid);
+    if (pw)
+    {
+        if (strcmp(pw->pw_name, "root") == 0)
+        {
+            if (specified_user && (strcmp(specified_user, "root") == 0))
+            {
+                // MaxScale was invoked as root and with --user=root.
+                acceptable = true;
+            }
+            else
+            {
+                fprintf(stderr, "Error: MaxScale cannot be run as root.\n");
+            }
+        }
+        else
+        {
+            acceptable = true;
+        }
+    }
+    else
+    {
+        fprintf(stderr, "Error: Could not obtain user information, MaxScale will not run: %s",
+                strerror(errno));
+    }
+
+    return acceptable;
+}

server/modules/routing/binlogrouter/blr.c

@@ -784,7 +784,7 @@ createInstance(SERVICE *service, char **options)
                "'tree' mode using GTID domain_id and server_id");
 
     /* Enable MariaDB the GTID maps store */
-    if (inst->mariadb10_compat && inst->mariadb10_master_gtid)
+    if (inst->mariadb10_compat)
     {
         /* Create/Open R/W GTID sqlite3 storage */
         if (!blr_open_gtid_maps_storage(inst))