Patch from solar to fix problems with get_name()

diff --git a/libbb/interface.c b/libbb/interface.c
index f3655b0e08f1e1daa91dc176fb10c31d067fd994..4632e2930b0473e9e83c2c697f4cfba194d395e4 100644 (file)
--- a/libbb/interface.c
+++ b/libbb/interface.c
@@ -15,7 +15,7 @@
  *              that either displays or sets the characteristics of
  *              one or more of the system's networking interfaces.
  *
- * Version:     $Id: interface.c,v 1.23 2004/07/23 01:49:46 bug1 Exp $
+ * Version:     $Id: interface.c,v 1.24 2004/08/12 16:52:00 andersen Exp $
  *
  * Author:      Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
  *              and others.  Copyright 1993 MicroWalt Corporation
@@ -986,31 +986,36 @@ static int if_readconf(void)
        return err;
 }
 
-static char *get_name(char *name, char *p)
+char *get_name(char *name, char *p)
 {
-       while (isspace(*p))
-               p++;
-       while (*p) {
-               if (isspace(*p))
-                       break;
-               if (*p == ':') {        /* could be an alias */
-                       char *dot = p, *dotname = name;
-
-                       *name++ = *p++;
-                       while (isdigit(*p))
-                               *name++ = *p++;
-                       if (*p != ':') {        /* it wasn't, backup */
-                               p = dot;
-                               name = dotname;
-                       }
-                       if (*p == '\0')
-                               return NULL;
-                       p++;
-                       break;
+       /* Extract <name>[:<alias>] from nul-terminated p where p matches
+          <name>[:<alias>]: after leading whitespace.
+          If match is not made, set name empty and return unchanged p */
+       int namestart=0, nameend=0, aliasend;
+       while (isspace(p[namestart]))
+               namestart++;
+       nameend=namestart;
+       while (p[nameend] && p[nameend]!=':' && !isspace(p[nameend]))
+               nameend++;
+       if (p[nameend]==':') {
+               aliasend=nameend+1;
+               while (p[aliasend] && isdigit(p[aliasend]))
+                       aliasend++;
+               if (p[aliasend]==':') {
+                       nameend=aliasend;
                }
-               *name++ = *p++;
+               if ((nameend-namestart)<IFNAMSIZ) {
+                       memcpy(name,&p[namestart],nameend-namestart);
+                       name[nameend-namestart]='\0';
+                       p=&p[nameend];
+               } else {
+                       /* Interface name too large */
+                       name[0]='\0';
+               }
+       } else {
+               /* first ':' not found - return empty */
+               name[0]='\0';
        }
-       *name++ = '\0';
        return p;
 }