fix #627: PermissionError may occur on Windows when binding ports fro…

…m a pre-configured PASV range.

HISTORY.rst

@@ -9,6 +9,11 @@ Version: 1.5.10 - (UNRELEASED)
 * #626: use argparse instead of deprecated optparse.
 * #628: use pytest instead of unittest.
 
+**Bug fixes**
+
+* #627: PermissionError may occur on Windows when binding ports from a
+  pre-configured PASV range.
+
 Version: 1.5.9 - 2023-10-25
 ===========================
 

pyftpdlib/_compat.py

@@ -58,6 +58,7 @@ def callable(obj):
     FileNotFoundError = FileNotFoundError  # NOQA
     FileExistsError = FileExistsError  # NOQA
     InterruptedError = InterruptedError  # NOQA
+    PermissionError = PermissionError  # NOQA
 else:
     # https://github.com/PythonCharmers/python-future/blob/exceptions/
     #     src/future/types/exceptions/pep3151.py
@@ -96,14 +97,18 @@ def __subclasscheck__(cls, classinfo):
     def FileNotFoundError(inst):
         return getattr(inst, 'errno', _SENTINEL) == errno.ENOENT
 
-    @_instance_checking_exception(EnvironmentError)
-    def FileExistsError(inst):
-        return getattr(inst, 'errno', _SENTINEL) == errno.EEXIST
-
     @_instance_checking_exception(EnvironmentError)
     def InterruptedError(inst):
         return getattr(inst, 'errno', _SENTINEL) == errno.EINTR
 
+    @_instance_checking_exception(EnvironmentError)
+    def PermissionError(inst):
+        return getattr(inst, 'errno', _SENTINEL) in (errno.EACCES, errno.EPERM)
+
+    @_instance_checking_exception(EnvironmentError)
+    def FileExistsError(inst):
+        return getattr(inst, 'errno', _SENTINEL) == errno.EEXIST
+
     if platform.python_implementation() != "CPython":
         try:
             raise OSError(errno.EEXIST, "perm")

pyftpdlib/handlers.py

@@ -34,6 +34,7 @@
 
 from . import __ver__
 from ._compat import PY3
+from ._compat import PermissionError
 from ._compat import b
 from ._compat import getcwdu
 from ._compat import super
@@ -477,6 +478,11 @@ def __init__(self, cmd_channel, extmode=False):
                 self.set_reuse_addr()
                 try:
                     self.bind((local_ip, port))
+                except PermissionError:
+                    self.cmd_channel.log(
+                        "ignoring EPERM when bind()ing port %s" % port,
+                        logfun=logger.debug,
+                    )
                 except socket.error as err:
                     if err.errno == errno.EADDRINUSE:  # port already in use
                         if ports: