Patch from solar to fix problems with get_name()

1 files changed, 28 insertions, 23 deletions

diff --git a/libbb/interface.c b/libbb/interface.c
index f3655b0e0..4632e2930 100644
--- 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;
 }