s3:smbd: let smbd/nmbd/winbindd child processes terminate if the parent process died.

This applies to all child processes making use of reinit_after_fork().
It is implemented by establishing a pipe between parent and child.
The child watches for EOF on the read end of the pipe, indidcating
an exited parent.

Pair-Programmed-With: Stefan Metzmacher <metze@samba.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/source3/winbindd/winbindd.c b/source3/winbindd/winbindd.c
index d1d36fd007..66e53d9cae 100644
--- a/source3/winbindd/winbindd.c
+++ b/source3/winbindd/winbindd.c
@@ -1461,6 +1461,17 @@ int main(int argc, char **argv, char **envp)
 		exit(1);
 	}
 
+	/*
+	 * Do not initialize the parent-child-pipe before becoming
+	 * a daemon: this is used to detect a died parent in the child
+	 * process.
+	 */
+	status = init_before_fork();
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0, ("init_before_fork failed: %s\n", nt_errstr(status)));
+		exit(1);
+	}
+
 	winbindd_register_handlers(!Fork);
 
 	status = init_system_info();