[src/trunk]: src/usr.bin/telnet use memmove() instead of strncpy() for overla...

[mrg <mrg%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/977d38e859d3
branches:  trunk
changeset: 1003900:977d38e859d3
user:      mrg <mrg%NetBSD.org@localhost>
date:      Fri Oct 04 11:39:44 2019 +0000

description:
use memmove() instead of strncpy() for overlapping strings.
ensure nul termination.

diffstat:

 usr.bin/telnet/commands.c |  11 ++++++-----
 1 files changed, 6 insertions(+), 5 deletions(-)

diffs (36 lines):

diff -r 2ad701a76353 -r 977d38e859d3 usr.bin/telnet/commands.c
--- a/usr.bin/telnet/commands.c Fri Oct 04 11:12:16 2019 +0000
+++ b/usr.bin/telnet/commands.c Fri Oct 04 11:39:44 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: commands.c,v 1.76 2019/01/05 08:55:58 maya Exp $       */
+/*     $NetBSD: commands.c,v 1.77 2019/10/04 11:39:44 mrg Exp $        */
 
 /*
  * Copyright (C) 1997 and 1998 WIDE Project.
@@ -63,7 +63,7 @@
 #if 0
 static char sccsid[] = "@(#)commands.c 8.4 (Berkeley) 5/30/95";
 #else
-__RCSID("$NetBSD: commands.c,v 1.76 2019/01/05 08:55:58 maya Exp $");
+__RCSID("$NetBSD: commands.c,v 1.77 2019/10/04 11:39:44 mrg Exp $");
 #endif
 #endif /* not lint */
 
@@ -2503,13 +2503,14 @@
            if (isspace((unsigned char)line[0]))
                continue;
            if (strncasecmp(line, m1, l1) == 0)
-               strncpy(line, &line[l1], sizeof(line) - l1);
+               memmove(line, &line[l1], sizeof(line) - l1 - 1);
            else if (strncasecmp(line, m2, l2) == 0)
-               strncpy(line, &line[l2], sizeof(line) - l2);
+               memmove(line, &line[l2], sizeof(line) - l2 - 1);
            else if (strncasecmp(line, "DEFAULT", 7) == 0)
-               strncpy(line, &line[7], sizeof(line) - 7);
+               memmove(line, &line[7], sizeof(line) - 7 - 1);
            else
                continue;
+           line[sizeof(line) - 1] = '\0';
            if (line[0] != ' ' && line[0] != '\t' && line[0] != '\n')
                continue;
            gotmachine = 1;