bpo-32394: Remove some TCP options on old version Windows. (GH-5523)
(cherry picked from commit 19e7d48ce89422091f9af93038b9fee075d46e9e)
Co-authored-by: animalize <animalize@users.noreply.github.com>
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index c1b24c1..c264d33 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -305,6 +305,70 @@
/* Provides the IsWindows7SP1OrGreater() function */
#include <VersionHelpers.h>
+/* remove some flags on older version Windows during run-time.
+ https://msdn.microsoft.com/en-us/library/windows/desktop/ms738596.aspx */
+typedef struct {
+ DWORD build_number; /* available starting with this Win10 BuildNumber */
+ const char flag_name[20];
+} FlagRuntimeInfo;
+
+/* IMPORTANT: make sure the list ordered by descending build_number */
+static FlagRuntimeInfo win_runtime_flags[] = {
+ /* available starting with Windows 10 1709 */
+ {16299, "TCP_KEEPIDLE"},
+ {16299, "TCP_KEEPINTVL"},
+ /* available starting with Windows 10 1703 */
+ {15063, "TCP_KEEPCNT"},
+ /* available starting with Windows 10 1607 */
+ {14393, "TCP_FASTOPEN"}
+};
+
+static void
+remove_unusable_flags(PyObject *m)
+{
+ PyObject *dict;
+ OSVERSIONINFOEX info;
+ DWORDLONG dwlConditionMask;
+
+ dict = PyModule_GetDict(m);
+ if (dict == NULL) {
+ return;
+ }
+
+ /* set to Windows 10, except BuildNumber. */
+ memset(&info, 0, sizeof(info));
+ info.dwOSVersionInfoSize = sizeof(info);
+ info.dwMajorVersion = 10;
+ info.dwMinorVersion = 0;
+
+ /* set Condition Mask */
+ dwlConditionMask = 0;
+ VER_SET_CONDITION(dwlConditionMask, VER_MAJORVERSION, VER_GREATER_EQUAL);
+ VER_SET_CONDITION(dwlConditionMask, VER_MINORVERSION, VER_GREATER_EQUAL);
+ VER_SET_CONDITION(dwlConditionMask, VER_BUILDNUMBER, VER_GREATER_EQUAL);
+
+ for (int i=0; i<sizeof(win_runtime_flags)/sizeof(FlagRuntimeInfo); i++) {
+ info.dwBuildNumber = win_runtime_flags[i].build_number;
+ /* greater than or equal to the specified version?
+ Compatibility Mode will not cheat VerifyVersionInfo(...) */
+ if (VerifyVersionInfo(
+ &info,
+ VER_MAJORVERSION|VER_MINORVERSION|VER_BUILDNUMBER,
+ dwlConditionMask)) {
+ break;
+ }
+ else {
+ if (PyDict_GetItemString(
+ dict,
+ win_runtime_flags[i].flag_name) != NULL) {
+ PyDict_DelItemString(
+ dict,
+ win_runtime_flags[i].flag_name);
+ }
+ }
+ }
+}
+
#endif
#include <stddef.h>
@@ -7890,5 +7954,11 @@
#if defined(USE_GETHOSTBYNAME_LOCK) || defined(USE_GETADDRINFO_LOCK)
netdb_lock = PyThread_allocate_lock();
#endif
+
+#ifdef MS_WINDOWS
+ /* remove some flags on older version Windows during run-time */
+ remove_unusable_flags(m);
+#endif
+
return m;
}