tftpd: show help if stdin is not a socket

1 files 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;