Merge ~ines-almeida/txpkgupload:allow-setting-passive-port-range into txpkgupload:master

[Ines Almeida]

Update twisted and txpkgupload to allow a passive port range config

The port range is used to get a DTP port within the range. This would allow one to restrict which ports it can connect to.

See:
 - https://docs.twisted.org/en/stable/api/twisted.protocols.ftp.FTPFactory.html
 - https://docs.twisted.org/en/stable/api/twisted.protocols.ftp.FTP.html#getDTPPort

[Colin Watson (cjwatson)]

review: Approve

diff --git a/src/txpkgupload/plugin.py b/src/txpkgupload/plugin.py
index b78923c..32ede15 100644
--- a/src/txpkgupload/plugin.py
+++ b/src/txpkgupload/plugin.py
@@ -244,7 +244,10 @@ class PkgUploadServiceMaker:
             port=ftp_config["port"],
             root=root,
             temp_dir=temp_dir,
-            idle_timeout=config["idle_timeout"])
+            idle_timeout=config["idle_timeout"],
+            min_passive_port=config.get("min_passive_port"),
+            max_passive_port=config.get("max_passive_port"),
+        )
         ftp_service.name = "ftp"
         ftp_service.setServiceParent(services)
 
diff --git a/src/txpkgupload/twistedftp.py b/src/txpkgupload/twistedftp.py
index 995fa08..4c019b6 100644
--- a/src/txpkgupload/twistedftp.py
+++ b/src/txpkgupload/twistedftp.py
@@ -360,7 +360,15 @@ class FTPWithEPSV(ftp.FTP):
 class FTPServiceFactory(service.Service):
     """A factory that makes an `FTPService`"""
 
-    def __init__(self, port, root, temp_dir, idle_timeout):
+    def __init__(
+        self,
+        port,
+        root,
+        temp_dir,
+        idle_timeout,
+        min_passive_port,
+        max_passive_port,
+    ):
         realm = FTPRealm(root, temp_dir)
         portal = Portal(realm)
         portal.registerChecker(AccessCheck())
@@ -371,14 +379,28 @@ class FTPServiceFactory(service.Service):
         factory.welcomeMessage = "Launchpad upload server"
         factory.timeOut = idle_timeout
 
+        if min_passive_port and max_passive_port:
+            factory.passivePortRange = range(
+                min_passive_port, max_passive_port
+            )
+
         self.ftpfactory = factory
         self.portno = port
 
     @staticmethod
-    def makeFTPService(port, root, temp_dir, idle_timeout):
+    def makeFTPService(
+        port, root, temp_dir, idle_timeout, min_passive_port, max_passive_port
+    ):
         if port.isdigit():
             strport = "tcp6:%s" % port
         else:
             strport = port
-        factory = FTPServiceFactory(port, root, temp_dir, idle_timeout)
+        factory = FTPServiceFactory(
+            port,
+            root,
+            temp_dir,
+            idle_timeout,
+            min_passive_port,
+            max_passive_port,
+        )
         return strports.service(strport, factory.ftpfactory)