1 files changed, 78 insertions, 0 deletions
diff --git a/netdisco/lms.py b/netdisco/lms.py
new file mode 100644
index 0000000..6026a86
--- /dev/null
+++ b/netdisco/lms.py
@@ -0,0 +1,78 @@
+"""Squeezebox/Logitech Media server discovery."""
+import socket
+
+from .const import ATTR_HOST, ATTR_PORT
+
+DISCOVERY_PORT = 3483
+DEFAULT_DISCOVERY_TIMEOUT = 2
+
+
+class LMS:
+    """Base class to discover Logitech Media servers."""
+
+    def __init__(self):
+        """Initialize the Logitech discovery."""
+        self.entries = []
+        self.last_scan = None
+
+    def scan(self):
+        """Scan the network."""
+        self.update()
+
+    def all(self):
+        """Scan and return all found entries."""
+        self.scan()
+        return list(self.entries)
+
+    def update(self):
+        """Scan network for Logitech Media Servers."""
+        lms_ip = '<broadcast>'
+        lms_port = DISCOVERY_PORT
+        lms_msg = b"eJSON\0"
+        lms_timeout = DEFAULT_DISCOVERY_TIMEOUT
+
+        entries = []
+
+        sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        sock.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
+        sock.settimeout(lms_timeout)
+        sock.bind(('', 0))
+
+        try:
+            sock.sendto(lms_msg, (lms_ip, lms_port))
+
+            while True:
+                try:
+                    data, server = sock.recvfrom(1024)
+                    if data.startswith(b'E'):
+                        # Full response is EJSON\xYYXXXX
+                        # Where YY is length of port string (ie 4)
+                        # And XXXX is the web interface port (ie 9000)
+                        port = None
+                        if data.startswith(b'JSON', 1):
+                            length = data[5:6][0]
+                            port = int(data[0-length:])
+                        entries.append({
+                            ATTR_HOST: server[0],
+                            ATTR_PORT: port,
+                        })
+                except socket.timeout:
+                    break
+        finally:
+            sock.close()
+        self.entries = entries
+
+
+def main():
+    """Test LMS discovery."""
+    from pprint import pprint
+
+    lms = LMS()
+
+    pprint("Scanning for Logitech Media Servers...")
+    lms.update()
+    pprint(lms.entries)
+
+
+if __name__ == "__main__":
+    main()