Add GDM implementation from netdisco

Author: jjlawren

plexapi/gdm.py

@@ -0,0 +1,114 @@
+"""
+Support for discovery using GDM (Good Day Mate), multicast protocol by Plex.
+
+# Licensed Apache 2.0
+# From https://github.com/home-assistant/netdisco/netdisco/gdm.py
+
+Inspired by
+  hippojay's plexGDM:
+  https://github.com/hippojay/script.plexbmc.helper/resources/lib/plexgdm.py
+  iBaa's PlexConnect: https://github.com/iBaa/PlexConnect/PlexAPI.py
+"""
+import socket
+import struct
+from typing import Any, Dict, List  # noqa: F401
+
+
+class GDM:
+    """Base class to discover GDM services."""
+
+    def __init__(self):
+        self.entries = []  # type: List[Dict[str, Any]]
+        self.last_scan = None
+
+    def scan(self):
+        """Scan the network."""
+        self.update()
+
+    def all(self):
+        """Return all found entries.
+
+        Will scan for entries if not scanned recently.
+        """
+        self.scan()
+        return list(self.entries)
+
+    def find_by_content_type(self, value):
+        """Return a list of entries that match the content_type."""
+        self.scan()
+        return [entry for entry in self.entries
+                if value in entry['data']['Content_Type']]
+
+    def find_by_data(self, values):
+        """Return a list of entries that match the search parameters."""
+        self.scan()
+        return [entry for entry in self.entries
+                if all(item in entry['data'].items()
+                       for item in values.items())]
+
+    def update(self):
+        """Scan for new GDM services.
+
+        Example of the dict list assigned to self.entries by this function:
+        [{'data': {
+             'Content-Type': 'plex/media-server',
+             'Host': '53f4b5b6023d41182fe88a99b0e714ba.plex.direct',
+             'Name': 'myfirstplexserver',
+             'Port': '32400',
+             'Resource-Identifier': '646ab0aa8a01c543e94ba975f6fd6efadc36b7',
+             'Updated-At': '1444852697',
+             'Version': '0.9.12.13.1464-4ccd2ca',
+          },
+          'from': ('10.10.10.100', 32414)}]
+        """
+
+        gdm_ip = '239.0.0.250'  # multicast to PMS
+        gdm_port = 32414
+        gdm_msg = 'M-SEARCH * HTTP/1.0'.encode('ascii')
+        gdm_timeout = 1
+
+        self.entries = []
+
+        # setup socket for discovery -> multicast message
+        sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        sock.settimeout(gdm_timeout)
+
+        # Set the time-to-live for messages for local network
+        sock.setsockopt(socket.IPPROTO_IP,
+                        socket.IP_MULTICAST_TTL,
+                        struct.pack("B", gdm_timeout))
+
+        try:
+            # Send data to the multicast group
+            sock.sendto(gdm_msg, (gdm_ip, gdm_port))
+
+            # Look for responses from all recipients
+            while True:
+                try:
+                    bdata, server = sock.recvfrom(1024)
+                    data = bdata.decode('utf-8')
+                    if '200 OK' in data.splitlines()[0]:
+                        ddata = {k: v.strip() for (k, v) in (
+                            line.split(':') for line in
+                            data.splitlines() if ':' in line)}
+                        self.entries.append({'data': ddata,
+                                             'from': server})
+                except socket.timeout:
+                    break
+        finally:
+            sock.close()
+
+
+def main():
+    """Test GDM discovery."""
+    from pprint import pprint
+
+    gdm = GDM()
+
+    pprint("Scanning GDM...")
+    gdm.update()
+    pprint(gdm.entries)
+
+
+if __name__ == "__main__":
+    main()