stdsock: Fix a bug in windows close

We must call shutdown before closing the socket. If we do not, it leaves the socket open on the remote if there is another connection to the same system. The socket will only close when all connections to that system close. Windows is broken in so many ways. Signed-off-by: Corey Minyard <[email protected]>
cminyard · Dec 18, 2024 · faf855e · faf855e
1 parent 1c74c72
commit faf855e
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Showing 2 changed files with 12 additions and 2 deletions.
diff --git a/lib/gensio_stdsock.c b/lib/gensio_stdsock.c
@@ -177,7 +177,15 @@ close_socket(struct gensio_os_funcs *o, int fd)
 
     assert(fd != -1);
 #ifdef _WIN32
-    err = closesocket(fd);
+    /*
+     * We must call shutdown before closing the socket.  If we do not, it
+     * leaves the socket open on the remote if there is another connection
+     * to the same system.  The socket will only close when all connections
+     * to that system close.  Windows is broken in so many ways.
+     */
+    err = shutdown(fd, SD_BOTH);
+    if (!err)
+	err = closesocket(fd);
 #else
     err = close(fd);
 #endif

diff --git a/lib/gensio_win.c b/lib/gensio_win.c
@@ -1284,8 +1284,10 @@ win_iod_socket_clean(struct gensio_iod_win *wiod)
 	WSACloseEvent(swiod->sockev);
     if (swiod->wakeev != WSA_INVALID_EVENT)
 	WSACloseEvent(swiod->wakeev);
-    if (wiod->fd != -1)
+    if (wiod->fd != -1) {
+	shutdown(wiod->fd, SD_BOTH);
 	closesocket(wiod->fd);
+    }
 }
 
 static int