[PATCH 1/3] win32: add qemu_close_to_socket()

[marcandre . lureau]

From: Marc-André Lureau <marcandre.lureau@redhat.com>

Close the given file descriptor, but returns the underlying SOCKET.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 include/sysemu/os-win32.h |  1 +
 util/oslib-win32.c        | 68 +++++++++++++++++++++------------------
 2 files changed, 38 insertions(+), 31 deletions(-)

diff --git a/include/sysemu/os-win32.h b/include/sysemu/os-win32.h
index e2849f88ab..95cba6b284 100644
--- a/include/sysemu/os-win32.h
+++ b/include/sysemu/os-win32.h
@@ -174,6 +174,7 @@ bool qemu_socket_unselect(int sockfd, Error **errp);
 /* We wrap all the sockets functions so that we can
  * set errno based on WSAGetLastError()
  */
+SOCKET qemu_close_to_socket(int fd);
 
 #undef close
 #define close qemu_close_wrap
diff --git a/util/oslib-win32.c b/util/oslib-win32.c
index 16f8a67f7e..e37276b414 100644
--- a/util/oslib-win32.c
+++ b/util/oslib-win32.c
@@ -479,52 +479,58 @@ int qemu_bind_wrap(int sockfd, const struct sockaddr 
*addr,
     return ret;
 }
 
-
 #undef close
-int qemu_close_wrap(int fd)
+SOCKET qemu_close_to_socket(int fd)
 {
-    int ret;
+    SOCKET s = _get_osfhandle(fd);
     DWORD flags = 0;
-    SOCKET s = INVALID_SOCKET;
-
-    if (fd_is_socket(fd)) {
-        s = _get_osfhandle(fd);
 
-        /*
-         * If we were to just call _close on the descriptor, it would close the
-         * HANDLE, but it wouldn't free any of the resources associated to the
-         * SOCKET, and we can't call _close after calling closesocket, because
-         * closesocket has already closed the HANDLE, and _close would attempt 
to
-         * close the HANDLE again, resulting in a double free. We can however
-         * protect the HANDLE from actually being closed long enough to close 
the
-         * file descriptor, then close the socket itself.
-         */
-        if (!GetHandleInformation((HANDLE)s, &flags)) {
-            errno = EACCES;
-            return -1;
-        }
-
-        if (!SetHandleInformation((HANDLE)s, HANDLE_FLAG_PROTECT_FROM_CLOSE, 
HANDLE_FLAG_PROTECT_FROM_CLOSE)) {
-            errno = EACCES;
-            return -1;
-        }
+    /*
+     * If we were to just call _close on the descriptor, it would close the
+     * HANDLE, but it wouldn't free any of the resources associated to the
+     * SOCKET, and we can't call _close after calling closesocket, because
+     * closesocket has already closed the HANDLE, and _close would attempt to
+     * close the HANDLE again, resulting in a double free. We can however
+     * protect the HANDLE from actually being closed long enough to close the
+     * file descriptor, then close the socket itself.
+     */
+    if (!GetHandleInformation((HANDLE)s, &flags)) {
+        errno = EACCES;
+        return INVALID_SOCKET;
     }
 
-    ret = close(fd);
-
-    if (s != INVALID_SOCKET && !SetHandleInformation((HANDLE)s, flags, flags)) 
{
+    if (!SetHandleInformation((HANDLE)s, HANDLE_FLAG_PROTECT_FROM_CLOSE, 
HANDLE_FLAG_PROTECT_FROM_CLOSE)) {
         errno = EACCES;
-        return -1;
+        return INVALID_SOCKET;
     }
 
     /*
      * close() returns EBADF since we PROTECT_FROM_CLOSE the underlying handle,
      * but the FD is actually freed
      */
-    if (ret < 0 && (s == INVALID_SOCKET || errno != EBADF)) {
-        return ret;
+    if (close(fd) < 0 && errno != EBADF) {
+        return INVALID_SOCKET;
+    }
+
+    if (!SetHandleInformation((HANDLE)s, flags, flags)) {
+        errno = EACCES;
+        return INVALID_SOCKET;
+    }
+
+    return s;
+}
+
+int qemu_close_wrap(int fd)
+{
+    SOCKET s = INVALID_SOCKET;
+    int ret = -1;
+
+    if (!fd_is_socket(fd)) {
+        return close(fd);
     }
 
+    s = qemu_close_to_socket(fd);
+
     if (s != INVALID_SOCKET) {
         ret = closesocket(s);
         if (ret < 0) {
-- 
2.39.2