daemon: When running external commands, open stdin as /dev/null

Previously when we ran external commands from the daemon, stdin
(ie. fd 0) was closed.  This caused a problem when running the
external hexdump command which seems to break if stdin is closed.

This patch opens stdin on /dev/null.

diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c
index 8c39c39..649a630 100644 (file)
--- a/daemon/guestfsd.c
+++ b/daemon/guestfsd.c
@@ -654,6 +654,7 @@ commandrv (char **stdoutput, char **stderror, char const* const *argv)
 
   if (pid == 0) {              /* Child process. */
     close (0);
+    open ("/dev/null", O_RDONLY); /* Set stdin to /dev/null (ignore failure) */
     close (so_fd[0]);
     close (se_fd[0]);
     dup2 (so_fd[1], 1);