[src/trunk]: src/sys/net avoid modifying the buffers, by checking for matchin...

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

details:   https://anonhg.NetBSD.org/src/rev/423062b6807b
branches:  trunk
changeset: 534501:423062b6807b
user:      christos <christos%NetBSD.org@localhost>
date:      Sun Jul 28 15:12:29 2002 +0000

description:
avoid modifying the buffers, by checking for matching lengths first. From
Frank Kardel.

diffstat:

 sys/net/if_spppsubr.c |  20 +++++++-------------
 1 files changed, 7 insertions(+), 13 deletions(-)

diffs (55 lines):

diff -r 9b1aefa1ab46 -r 423062b6807b sys/net/if_spppsubr.c
--- a/sys/net/if_spppsubr.c     Sun Jul 28 08:58:59 2002 +0000
+++ b/sys/net/if_spppsubr.c     Sun Jul 28 15:12:29 2002 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_spppsubr.c,v 1.52 2002/07/27 19:09:07 christos Exp $         */
+/*     $NetBSD: if_spppsubr.c,v 1.53 2002/07/28 15:12:29 christos Exp $         */
 
 /*
  * Synchronous PPP/Cisco link level subroutines.
@@ -28,7 +28,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_spppsubr.c,v 1.52 2002/07/27 19:09:07 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_spppsubr.c,v 1.53 2002/07/28 15:12:29 christos Exp $");
 
 #include "opt_inet.h"
 #include "opt_ipx.h"
@@ -4195,7 +4195,7 @@
        struct lcp_header *h;
        int len, x;
        u_char mlen;
-       char *name, *secret, sname, ssecret;
+       char *name, *secret;
        int name_len, secret_len;
 
        len = m->m_pkthdr.len;
@@ -4247,14 +4247,10 @@
                        sppp_print_string((char*)secret, secret_len);
                        addlog(">\n");
                }
-               sname = name[name_len];
-               ssecret = secret[secret_len];
-               name[name_len] = '\0';
-               secret[secret_len] = '\0';
-               if (strcmp(name, sp->hisauth.name) != 0 ||
-                   strcmp(secret, sp->hisauth.secret) != 0) {
-                       name[name_len] = sname;
-                       secret[secret_len] = ssecret;
+               if (name_len != strlen(sp->hisauth.name) ||
+                   memcmp(name, sp->hisauth.name, name_len) != 0 ||
+                   secret_len != strlen(sp->hisauth.secret) ||
+                   memcmp(secret, sp->hisauth.secret, secret_len) != 0) {
                        /* action scn, tld */
                        sp->pp_auth_failures++;
                        mlen = sizeof(FAILMSG) - 1;
@@ -4265,8 +4261,6 @@
                        pap.tld(sp);
                        break;
                }
-               name[name_len] = sname;
-               secret[secret_len] = ssecret;
                /* action sca, perhaps tlu */
                if (sp->state[IDX_PAP] == STATE_REQ_SENT ||
                    sp->state[IDX_PAP] == STATE_OPENED) {