RAHHH

backend/lib/python3.12/site-packages/twisted/runner/inetd.py

@@ -0,0 +1,80 @@
+# Copyright (c) Twisted Matrix Laboratories.
+# See LICENSE for details.
+
+#
+
+"""
+Twisted inetd.
+
+Maintainer: Andrew Bennetts
+
+Future Plans: Bugfixes.  Specifically for UDP and Sun-RPC, which don't work
+correctly yet.
+"""
+
+import os
+
+from twisted.internet import fdesc, process, reactor
+from twisted.internet.protocol import Protocol, ServerFactory
+from twisted.protocols import wire
+
+# A dict of known 'internal' services (i.e. those that don't involve spawning
+# another process.
+internalProtocols = {
+    "echo": wire.Echo,
+    "chargen": wire.Chargen,
+    "discard": wire.Discard,
+    "daytime": wire.Daytime,
+    "time": wire.Time,
+}
+
+
+class InetdProtocol(Protocol):
+    """Forks a child process on connectionMade, passing the socket as fd 0."""
+
+    def connectionMade(self):
+        sockFD = self.transport.fileno()
+        childFDs = {0: sockFD, 1: sockFD}
+        if self.factory.stderrFile:
+            childFDs[2] = self.factory.stderrFile.fileno()
+
+        # processes run by inetd expect blocking sockets
+        # FIXME: maybe this should be done in process.py?  are other uses of
+        #        Process possibly affected by this?
+        fdesc.setBlocking(sockFD)
+        if 2 in childFDs:
+            fdesc.setBlocking(childFDs[2])
+
+        service = self.factory.service
+        uid = service.user
+        gid = service.group
+
+        # don't tell Process to change our UID/GID if it's what we
+        # already are
+        if uid == os.getuid():
+            uid = None
+        if gid == os.getgid():
+            gid = None
+
+        process.Process(
+            None,
+            service.program,
+            service.programArgs,
+            os.environ,
+            None,
+            None,
+            uid,
+            gid,
+            childFDs,
+        )
+
+        reactor.removeReader(self.transport)
+        reactor.removeWriter(self.transport)
+
+
+class InetdFactory(ServerFactory):
+    protocol = InetdProtocol
+    stderrFile = None
+
+    def __init__(self, service):
+        self.service = service