Correct handling of IP addresses in Python bindings.

This adds support for proper forward and reverse host resolution using
the new BackendServerIP6 setting.

Author: wagnerrp

mythtv/bindings/python/MythTV/database.py

@@ -1085,19 +1085,41 @@ def _check_schema(self, value, local, name='Database', update=None):
             else:
                 update(self).run()
 
-    def gethostname(self):
-        return self.dbconn['LocalHostName']
+    def _gethostfromaddr(self, addr, value=None):
+        if value is None:
+            for value in ['BackendServerIP','BackendServerIP6']:
+                try:
+                    return self._gethostfromaddr(addr, value)
+                except MythDBError:
+                    pass
+            else:
+                raise MythDBError(MythError.DB_SETTING,
+                                    'BackendServerIP[6]', addr)
 
-    def getMasterBackend(self):
-        ip = self.settings.NULL.MasterServerIP
         with self as cursor:
             if cursor.execute("""SELECT hostname FROM settings
-                                     WHERE value='BackendServerIP'
-                                     AND data=?""", [ip]) == 0:
-                # no match found
-                raise MythDBError(MythError.DB_SETTING, 'BackendServerIP', ip)
+                                  WHERE value=? AND data=?""", [value, addr]) == 0:
+                raise MythDBError(MythError.DB_SETTING, value, addr)
             return cursor.fetchone()[0]
 
+    def _getpreferredaddr(self, host):
+        ip6 = self.settings[host].BackendServerIP6
+        ip4 = self.settings[host].BackendServerIP
+        if ip6 is None:
+            if ip4 is None:
+                raise MythDBError(MythError.DB_SETTING,
+                                    'BackendServerIP[6]', host)
+            return ip4
+        elif (ip6 in ['::1', '0:0:0;0:0:0:0:1']) and (ip4 != '127.0.0.1'):
+            return ip4
+        return ip6
+
+    def gethostname(self):
+        return self.dbconn['LocalHostName']
+
+    def getMasterBackend(self):
+        return self._gethostfromaddr(self.settings.NULL.MasterServerIP)
+
     def getStorageGroup(self, groupname=None, hostname=None):
         """
         obj.getStorageGroup(groupname=None, hostname=None)

mythtv/bindings/python/MythTV/methodheap.py

@@ -1100,13 +1100,7 @@ def __init__(self, backend=None, port=None, db=None):
         if re.match('(?:\d{1,3}\.){3}\d{1,3}',backend) or \
                     check_ipv6(backend):
             # process ip address
-            with self.db.cursor(self.log) as cursor:
-                if cursor.execute("""SELECT hostname FROM settings
-                                     WHERE value='BackendServerIP'
-                                     AND data=%s""", backend) == 0:
-                    raise MythDBError(MythError.DB_SETTING, 
-                                        backend+': BackendServerIP')
-                host = cursor.fetchone()[0]
+            host = self.db._gethostfromaddr(backend)
             self.host = backend
             self.port = int(self.db.settings[host].BackendStatusPort)
         else:

mythtv/bindings/python/MythTV/mythproto.py

@@ -69,33 +69,25 @@ def __init__(self, backend=None, blockshutdown=False, events=False, db=None):
         if backend is None:
             # no backend given, use master
             self.host = self.db.settings.NULL.MasterServerIP
+            self.hostname = self.db._gethostfromaddr(self.host)
 
         else:
             backend = backend.strip('[]')
+            query = "SELECT hostname FROM settings WHERE value=? AND data=?"
             if self._reip.match(backend):
                 # given backend is IP address
                 self.host = backend
+                self.hostname = self.db._gethostfromaddr(
+                                            backend, 'BackendServerIP')
             elif check_ipv6(backend):
                 # given backend is IPv6 address
                 self.host = backend
+                self.hostname = self.db._gethostfromaddr(
+                                            backend, 'BackendServerIP6')
             else:
                 # given backend is hostname, pull address from database
                 self.hostname = backend
-                self.host = self.db.settings[backend].BackendServerIP
-                if not self.host:
-                    raise MythDBError(MythError.DB_SETTING,
-                                            'BackendServerIP', backend)
-
-        if self.hostname is None:
-            # reverse lookup hostname from address
-            with self.db.cursor(self.log) as cursor:
-                if cursor.execute("""SELECT hostname FROM settings
-                                     WHERE value='BackendServerIP'
-                                     AND data=?""", [self.host]) == 0:
-                    # no match found
-                    raise MythDBError(MythError.DB_SETTING, 'BackendServerIP',
-                                            self.host)
-                self.hostname = cursor.fetchone()[0]
+                self.host = self.db._getpreferredaddr(backend)
 
         # lookup port from database
         self.port = int(self.db.settings[self.hostname].BackendServerPort)
@@ -248,13 +240,7 @@ def ftopen(file, mode, forceremote=False, nooverwrite=False, db=None, \
     # get full system name
     host = host.strip('[]')
     if reip.match(host) or check_ipv6(host):
-        with db.cursor(log) as cursor:
-            if cursor.execute("""SELECT hostname FROM settings
-                                 WHERE value='BackendServerIP'
-                                 AND data=%s""", host) == 0:
-                raise MythDBError(MythError.DB_SETTING, \
-                                  'BackendServerIP', backend)
-            host = cursor.fetchone()[0]
+        host = db._gethostfromaddr(host)
 
     # user forced to remote access
     if forceremote: