main/busybox: add support for nologin applet

This will never be upstreamed, I have tried. It is fairly simple
to maintain separately so I think we will try that.

1 files changed, 38 insertions, 0 deletions

diff --git a/main/busybox/nologin.c b/main/busybox/nologin.c
new file mode 100644
index 0000000000..e0a4c56c77
--- /dev/null
+++ b/main/busybox/nologin.c
@@ -0,0 +1,38 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * nologin implementation for busybox
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+
+//config:config NOLOGIN
+//config:	bool "nologin"
+//config:	default n
+//config:	help
+//config:	  nologin is a tool that is supposed to be the shell for user accounts
+//config:	  that are not supposed to login.
+
+//applet:IF_NOLOGIN(APPLET(nologin, BB_DIR_SBIN, BB_SUID_DROP))
+//kbuild:lib-$(CONFIG_NOLOGIN) += nologin.o
+
+//usage:#define nologin_trivial_usage
+//usage:       ""
+//usage:#define nologin_full_usage "\n\n"
+//usage:       "politely refuse a login\n"
+
+#include "libbb.h"
+#include <syslog.h>
+
+#define _NOLOGIN_TXT "/etc/nologin.txt"
+
+int nologin_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int nologin_main(int argc UNUSED_PARAM, char **argv)
+{
+	int fd;
+	fd = open(_NOLOGIN_TXT, O_RDONLY);
+	if (bb_copyfd_eof(fd, STDOUT_FILENO) == -1)
+		bb_error_msg_and_die("this account is not available");
+	close(fd);
+	return 1;
+}
+