try not use socket share

sshuttle/client.py

@@ -223,13 +223,13 @@ class FirewallClient:
             argv_tries.append(argvbase)
         else:
             if sys.platform == 'win32':
-                argv_tries.append(argvbase)
                 # runas_path = which("runas")
                 # if runas_path:
                 #   argv_tries.append([runas_path , '/noprofile', '/user:Administrator',  'python'])
-                # XXX:attempt to elevate privilege using 'runas' in windows seems not working.
+                # XXX: Attempt to elevate privilege using 'runas' in windows seems not working.
-                # This is due to underlying ShellExecute() Windows api does not allow child process to inherit stdio.
+                # Because underlying ShellExecute() Windows api does not allow child process to inherit stdio.
-                # TODO(nom3ad): try to implement another way to achieve this.
+                # TODO(nom3ad): Try to implement another way to achieve this.
+                raise Fatal("Privilege elevation for Windows is not yet implemented. Please run from an administrator shell")
             else:
                 # Linux typically uses sudo; OpenBSD uses doas. However, some
                 # Linux distributions are starting to use doas.
@@ -294,22 +294,32 @@ class FirewallClient:
                     return s2.makefile('rwb')
 
             else:
-                (s1, s2) = socket.socketpair()
+                # In windows, if client/firewall processes is running as admin user, stdio can be used for communication.
-                pstdout = None
+                # But if firewall process is run with elevated mode, access to stdio is lost. 
+                # So we have to use a socketpair (as in unix).
+                # But socket need to be "shared" to child process as it can't be directly set as stdio in Windows 
+                can_use_stdio = is_admin_user() 
+                pstdout = ssubprocess.PIPE if can_use_stdio else None
                 pstdin = ssubprocess.PIPE
                 preexec_fn = None
                 penv = os.environ.copy()
                 penv['PYTHONPATH'] = os.path.dirname(os.path.dirname(__file__))
 
                 def get_pfile():
-                    import base64
+                    if can_use_stdio:  
-                    socket_share_data = s1.share(self.p.pid)
+                        import io
-                    s1.close()
+                        self.p.stdin.write(b'STDIO:\n')
-                    socket_share_data_b64 = base64.b64encode(socket_share_data)
+                        self.p.stdin.flush()
-                    self.p.stdin.write(socket_share_data_b64 + b'\n')
+                        return io.BufferedRWPair(self.p.stdout, self.p.stdin, 1)
-                    self.p.stdin.flush()
+                    else:
-                    return s2.makefile('rwb')
+                        import base64
-
+                        (s1, s2) = socket.socketpair()
+                        socket_share_data = s1.share(self.p.pid)
+                        s1.close()
+                        socket_share_data_b64 = base64.b64encode(socket_share_data)
+                        self.p.stdin.write(b'SOCKETSHARE:' + socket_share_data_b64 + b'\n')
+                        self.p.stdin.flush()
+                        return s2.makefile('rwb')
             try:
                 debug1("Starting firewall manager with command: %r" % argv)
                 self.p = ssubprocess.Popen(argv, stdout=pstdout, stdin=pstdin, env=penv,

sshuttle/firewall.py

@@ -121,13 +121,22 @@ def _setup_daemon_windows():
 
     signal.signal(signal.SIGTERM, firewall_exit)
     signal.signal(signal.SIGINT, firewall_exit)
-    socket_share_data_b64 = sys.stdin.readline()
+
-    # debug3(f'FROM_SHARE ${socket_share_data_b64=}')
+    socket_share_data_prefix = 'SOCKETSHARE:'
-    socket_share_data = base64.b64decode(socket_share_data_b64)
+    line = sys.stdin.readline().strip()
-    sock = socket.fromshare(socket_share_data)
+    if line.startswith('SOCKETSHARE:'):
-    sys.stdin = io.TextIOWrapper(sock.makefile('rb', buffering=0))
+        debug3('Using shared socket for communicating with sshuttle client process')
-    sys.stdout = io.TextIOWrapper(sock.makefile('wb', buffering=0), write_through=True)
+        socket_share_data_b64 = line[len(socket_share_data_prefix):]
-    sock.close()
+        socket_share_data = base64.b64decode(socket_share_data_b64)
+        sock = socket.fromshare(socket_share_data)
+        sys.stdin = io.TextIOWrapper(sock.makefile('rb', buffering=0))
+        sys.stdout = io.TextIOWrapper(sock.makefile('wb', buffering=0), write_through=True)
+        sock.close()
+    elif line.startswith("STDIO:"):
+        debug3('Using inherited stdio for communicating with sshuttle client process')
+    else:
+        raise Fatal("Unexpected stdin: " + line)
+
     return sys.stdin, sys.stdout