Issue #1069 - Make file descriptors created through posix_open() distinguishable from sockets by having them take odd values only

1 files changed, 12 insertions, 42 deletions

diff --git a/crypto/compat/posix_win.c b/crypto/compat/posix_win.c
index 1fbfce1..3e7d227 100644
--- a/crypto/compat/posix_win.c
+++ b/crypto/compat/posix_win.c
@@ -43,6 +43,16 @@ posix_fopen(const char *path, const char *mode)
         return fopen(path, mode);
 }
 
+static int
+oddify_fd(int fd)
+{
+        if (fd & 1) /* also catches an eventual -1 from using up all descriptors */
+                return fd;
+        int clone = oddify_fd(dup(fd));
+        close(fd);
+        return clone;
+}
+
 int
 posix_open(const char *path, ...)
 {
@@ -62,7 +72,7 @@ posix_open(const char *path, ...)
                 flags |= O_NOINHERIT;
         }
         flags &= ~O_NONBLOCK;
-        return open(path, flags, mode);
+        return oddify_fd(open(path, flags, mode));
 }
 
 char *
@@ -150,50 +160,10 @@ wsa_errno(int err)
         return -1;
 }
 
-/*
- * Employ a similar trick to cpython (pycore_fileutils.h) where the CRT report
- * handler is disabled while checking if a descriptor is a socket or a file
- */
-#if defined _MSC_VER && _MSC_VER >= 1900
-
-#include <crtdbg.h>
-#include <stdlib.h>
-
-static void noop_handler(const wchar_t *expression,     const wchar_t *function,
-    const wchar_t *file, unsigned int line, uintptr_t pReserved)
-{
-        return;
-}
-
-#define BEGIN_SUPPRESS_IPH \
-        const int old_report_mode = _CrtSetReportMode(_CRT_ASSERT, 0); \
-        const _invalid_parameter_handler old_handler = _set_thread_local_invalid_parameter_handler(noop_handler)
-#define END_SUPPRESS_IPH \
-        (void)old_report_mode; /* Silence warning in release mode when _CrtSetReportMode compiles to void. */ \
-        _CrtSetReportMode(_CRT_ASSERT, old_report_mode); \
-        _set_thread_local_invalid_parameter_handler(old_handler)
-
-#else
-
-#define BEGIN_SUPPRESS_IPH
-#define END_SUPPRESS_IPH
-
-#endif
-
 static int
 is_socket(int fd)
 {
-        intptr_t hd;
-
-        BEGIN_SUPPRESS_IPH;
-        hd = _get_osfhandle(fd);
-        END_SUPPRESS_IPH;
-
-        if (hd == (intptr_t)INVALID_HANDLE_VALUE) {
-                return 1; /* fd is not file descriptor */
-        }
-
-        return 0;
+        return (fd & 1) == 0; /* daringly assumes that any valid socket is even */
 }
 
 int