Randomize fileserver port

src/Config.py

@@ -212,7 +212,8 @@ class Config(object):
         self.parser.add_argument('--workers', help='Download workers per site', default=5, type=int, metavar='workers')
 
         self.parser.add_argument('--fileserver_ip', help='FileServer bind address', default="*", metavar='ip')
-        self.parser.add_argument('--fileserver_port', help='FileServer bind port', default=15441, type=int, metavar='port')
+        self.parser.add_argument('--fileserver_port', help='FileServer bind port (0: randomize)', default=0, type=int, metavar='port')
+        self.parser.add_argument('--fileserver_port_range', help='FileServer randomization range', default="10000-40000", metavar='port')
         self.parser.add_argument('--ip_local', help='My local ips', default=ip_local, type=int, metavar='ip', nargs='*')
 
         self.parser.add_argument('--disable_udp', help='Disable UDP connections', action='store_true')

src/Connection/ConnectionServer.py

@@ -61,22 +61,25 @@ class ConnectionServer(object):
             )
             sys.exit(0)
 
-        if port:  # Listen server on a port
-            self.pool = Pool(500)  # do not accept more than 500 connections
-            self.stream_server = StreamServer(
-                (ip.replace("*", "0.0.0.0"), port), self.handleIncomingConnection, spawn=self.pool, backlog=100
-            )
-            if request_handler:
-                self.handleRequest = request_handler
+        if request_handler:
+            self.handleRequest = request_handler
 
     def start(self):
         self.running = True
         CryptConnection.manager.loadCerts()
+        if not self.port:
+            self.log.info("No port found, not binding")
+            return False
+
         self.log.debug("Binding to: %s:%s, (msgpack: %s), supported crypt: %s" % (
             self.ip, self.port,
             ".".join(map(str, msgpack.version)), CryptConnection.manager.crypt_supported)
         )
         try:
+            self.pool = Pool(500)  # do not accept more than 500 connections
+            self.stream_server = StreamServer(
+                (self.ip, self.port), self.handleIncomingConnection, spawn=self.pool, backlog=100
+            )
             self.stream_server.serve_forever()  # Start normal connection server
         except Exception, err:
             self.log.info("StreamServer bind error, must be running already: %s" % err)

src/File/FileServer.py

@@ -3,6 +3,7 @@ import urllib2
 import re
 import time
 import random
+import socket
 
 import gevent
 
@@ -20,10 +21,21 @@ from Plugin import PluginManager
 class FileServer(ConnectionServer):
 
     def __init__(self, ip=config.fileserver_ip, port=config.fileserver_port):
-        ConnectionServer.__init__(self, ip, port, self.handleRequest)
-
         self.site_manager = SiteManager.site_manager
         self.log = logging.getLogger("FileServer")
+        ip = ip.replace("*", "0.0.0.0")
+
+        should_use_random_port = port == 0 or config.tor == "always"
+        if should_use_random_port:
+            port_range_from, port_range_to = map(int, config.fileserver_port_range.split("-"))
+            port = self.getRandomPort(ip, port_range_from, port_range_to)
+            config.fileserver_port = port
+            if not port:
+                raise Exception("Can't find bindable port")
+            if not config.tor == "always":
+                config.saveValue("fileserver_port", port)  # Save random port value for next restart
+
+        ConnectionServer.__init__(self, ip, port, self.handleRequest)
 
         if config.ip_external:  # Ip external defined in arguments
             self.port_opened = True
@@ -36,6 +48,28 @@ class FileServer(ConnectionServer):
         self.files_parsing = {}
         self.ui_server = None
 
+    def getRandomPort(self, ip, port_range_from, port_range_to):
+        self.log.info("Getting random port in range %s-%s..." % (port_range_from, port_range_to))
+        tried = []
+        for bind_retry in range(100):
+            port = random.randint(port_range_from, port_range_to)
+            if port in tried:
+                continue
+            tried.append(port)
+            sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            try:
+                sock.bind((ip, port))
+                success = True
+            except Exception as err:
+                self.log.warning("Error binding to port %s: %s" % (port, err))
+                success = False
+            sock.close()
+            if success:
+                return port
+            else:
+                time.sleep(0.1)
+        return False
+
     # Handle request to fileserver
     def handleRequest(self, connection, message):
         if config.verbose: