From 7ef7fa8a8db0774a2f75b76d0bda96022b0e10e9 Mon Sep 17 00:00:00 2001
From: "Nicholas J. Kain" <nicholas@kain.us>
Date: Wed, 27 Jul 2011 00:37:11 -0400
Subject: [PATCH] Fix the return value of ifchd_cmd_str() and correct its
 length check.

---
 ndhc/ifchange.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/ndhc/ifchange.c b/ndhc/ifchange.c
index fc004d0..e1d7a6b 100644
--- a/ndhc/ifchange.c
+++ b/ndhc/ifchange.c
@@ -121,12 +121,12 @@ static int ifchd_cmd_str(char *buf, size_t buflen, char *optname,
 {
     char *obuf = buf;
     buf += snprintf(buf, buflen, "%s:", optname);
-    if (buflen < optlen + 1)
+    if (buflen < (buf - obuf) + optlen + 2)
         return -1;
     memcpy(buf, optdata, optlen);
     buf[optlen] = ':';
     buf[optlen+1] = '\0';
-    return (buf - obuf) + optlen;
+    return (buf - obuf) + optlen + 1;
 }
 
 #define IFCHD_SW_CMD(x, y) case DCODE_##x: \