From 5472b903858d16a158e502f97c93236b7681ceae Mon Sep 17 00:00:00 2001
From: c0mmit <thisforeda@live.cn>
Date: Thu, 10 Jun 2021 14:52:44 +0800
Subject: [PATCH] fix wrong errno

---
 iptc/ip4tc.py |  5 ++---
 iptc/util.py  | 14 ++++++++------
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/iptc/ip4tc.py b/iptc/ip4tc.py
index 4ddd2dc..00c9c44 100644
--- a/iptc/ip4tc.py
+++ b/iptc/ip4tc.py
@@ -27,8 +27,6 @@
 _IFNAMSIZ = 16
 
 _libc = find_libc()
-_get_errno_loc = _libc.__errno_location
-_get_errno_loc.restype = ct.POINTER(ct.c_int)
 _malloc = _libc.malloc
 _malloc.restype = ct.POINTER(ct.c_ubyte)
 _malloc.argtypes = [ct.c_size_t]
@@ -1655,7 +1653,8 @@ def builtin_chain(self, chain):
 
     def strerror(self):
         """Returns any pending iptables error from the previous operation."""
-        errno = _get_errno_loc()[0]
+        errno = ct.get_errno()
+        ct.set_errno(0)
         if errno == 0:
             return "libiptc version error"
         return self._iptc.iptc_strerror(errno)
diff --git a/iptc/util.py b/iptc/util.py
index 04fe905..a2cbc4b 100644
--- a/iptc/util.py
+++ b/iptc/util.py
@@ -54,25 +54,27 @@ def load_kernel(name, exc_if_failed=False):
 def _do_find_library(name):
     if '/' in name:
         try:
-            return ctypes.CDLL(name, mode=ctypes.RTLD_GLOBAL)
+            return ctypes.CDLL(name, mode=ctypes.RTLD_GLOBAL, use_errno=True)
         except Exception:
             return None
     p = ctypes.util.find_library(name)
     if p:
-        lib = ctypes.CDLL(p, mode=ctypes.RTLD_GLOBAL)
+        lib = ctypes.CDLL(p, mode=ctypes.RTLD_GLOBAL, use_errno=True)
         return lib
 
     # probably we have been installed in a virtualenv
     try:
         lib = ctypes.CDLL(os.path.join(get_python_lib(), name),
-                          mode=ctypes.RTLD_GLOBAL)
+                          mode=ctypes.RTLD_GLOBAL,
+                          use_errno=True)
         return lib
     except:
         pass
 
     for p in sys.path:
         try:
-            lib = ctypes.CDLL(os.path.join(p, name), mode=ctypes.RTLD_GLOBAL)
+            lib = ctypes.CDLL(os.path.join(p, name), mode=ctypes.RTLD_GLOBAL,
+                                use_errno=True)
             return lib
         except:
             pass
@@ -121,12 +123,12 @@ def find_library(*names):
 def find_libc():
     lib = ctypes.util.find_library('c')
     if lib is not None:
-        return ctypes.CDLL(lib, mode=ctypes.RTLD_GLOBAL)
+        return ctypes.CDLL(lib, mode=ctypes.RTLD_GLOBAL, use_errno=True)
 
     libnames = ['libc.so.6', 'libc.so.0', 'libc.so']
     for name in libnames:
         try:
-            lib = ctypes.CDLL(name, mode=ctypes.RTLD_GLOBAL)
+            lib = ctypes.CDLL(name, mode=ctypes.RTLD_GLOBAL, use_errno=True)
             return lib
         except:
             pass