From 5a89763fb7e57d4fc3d393eafa35c58f8285a083 Mon Sep 17 00:00:00 2001
From: Denis Vlasenko <vda.linux@googlemail.com>
Date: Sat, 1 Nov 2008 00:22:24 +0000
Subject: [PATCH] tftpd: show help if stdin is not a socket

---
 networking/tftp.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/networking/tftp.c b/networking/tftp.c
index 07d672dcb..eb39e9c54 100644
--- a/networking/tftp.c
+++ b/networking/tftp.c
@@ -653,8 +653,15 @@ int tftpd_main(int argc UNUSED_PARAM, char **argv)
 	INIT_G();
 
 	our_lsa = get_sock_lsa(STDIN_FILENO);
-	if (!our_lsa)
-		bb_perror_msg_and_die("stdin is not a socket");
+	if (!our_lsa) {
+		/* This is confusing:
+		 *bb_error_msg_and_die("stdin is not a socket");
+		 * Better: */
+		bb_show_usage();
+		/* Help text says that tftpd must be used as inetd service,
+		 * which is by far the most usual cause of get_sock_lsa
+		 * failure */
+	}
 	peer_lsa = xzalloc(LSA_LEN_SIZE + our_lsa->len);
 	peer_lsa->len = our_lsa->len;