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/********************************************************************
* $Author: lindner $
* $Revision: 3.10 $
* $Date: 1995/09/25 05:02:32 $
* $Source: /home/arcwelder/GopherSrc/CVS/gopher+/gopherd/dedot.c,v $
* $State: Exp $
*
* Paul Lindner, University of Minnesota CIS.
*
* Copyright 1991, 1992 by the Regents of the University of Minnesota
* see the file "Copyright" in the distribution for conditions of use.
*********************************************************************
* MODULE: dedot.c
* See below.
*********************************************************************
* Revision History:
* $Log: dedot.c,v $
* Revision 3.10 1995/09/25 05:02:32 lindner
* Convert to ANSI C
*
* Revision 3.9 1994/04/22 03:35:16 lindner
* Fix for spinning gopherd processes
*
* Revision 3.8 1994/04/14 15:48:52 lindner
* Fix for files with single quotes
*
* Revision 3.7 1994/03/04 23:25:14 lindner
* Fix for dedot weirdness
*
* Revision 3.6 1993/09/18 03:26:38 lindner
* Important Security fix
*
* Revision 3.5 1993/08/23 18:33:57 lindner
* Fix off by one error
*
* Revision 3.4 1993/08/06 14:28:14 lindner
* Further strip out single quotes
*
* Revision 3.3 1993/08/05 22:19:43 lindner
* Fix for single quotes
*
* Revision 3.2 1993/08/05 20:43:07 lindner
* Added fix for dedot to remove quotes for when using system or popen
*
* Revision 3.1.1.1 1993/02/11 18:02:50 lindner
* Gopher+1.2beta release
*
* Revision 1.1 1992/12/10 23:13:27 lindner
* gopher 1.1 release
*
*
*********************************************************************/
#include <stdio.h>
/*
** These routines can be used to remove ../ and ./ entries from
** pathnames. These routines do it radically, without any attempt
** at all at interpretation. This is okay for a gopher server,
** because clients aren't supposed to ask for .. or . in a request.
**
** We want to do this so that we can avoid the chroot(), so that we
** can have symbolic links under the gopher directory to other things
** (like man pages for example) outside our structure, and still be
** safe. Unless of course someone makes a link to / or somewhere silly.
**
** dedot1 will remove dots from one string in place, dedot2 will copy
** one to the other, removing in the process - the src and dst can be
** the same. dedot1 can use this to advantage - it checks first if
** things have to be removed, and calls dedot2 if necessary. This
** is a slight advantage because in most cases we won't do anything,
** and we save the expense of copying data back and forth. This
** seems to save almost half the time (very loose testing though).
**
** John Sellens jmsellens@watdragon.waterloo.edu
*/
void dequote1(char *);
void dedot1(char *);
void dedot2(char *, char *);
void
dequote1(char *src)
{
char *cp2;
/** Strip out the quotes.. **/
while (*src != '\0') {
if (*src == '"' || *src == '\'') {
for (cp2=src; *cp2 != '\0'; cp2++) {
*cp2 = *(cp2+1);
}
}
src++;
}
}
void
dedot1(char *src )
{
dequote1(src);
if ( *src == '.' ) {
if (src[1] == '\0' || src[1] == '/' ||
( src[1] == '.' && ( src[2] == '\0' || src[2] == '/' ) ) ) {
dedot2( src, src );
return;
}
}
while ( *src ) {
if ( *src++ == '/' ) {
if ( *src == '.' ) {
if (src[1] == '\0' || src[1] == '/' ||
( src[1] == '.' && ( src[2] == '\0' || src[2] == '/' ) ) ) {
dedot2( src, src );
return;
}
}
}
}
return;
}
/* copy src to dst, blindly removing (not interpreting) ./ and ../ */
void
dedot2(char *src, char *dst)
{
/*
** We either have /, a filename, ./ or ../
*/
int i;
while ( *src ) {
switch ( *src ) {
case '/':
/* copy it, and skip any extras e.g. /a///b */
*dst++ = *src++;
while ( *src == '/' )
src++;
break;
case '.':
/* don't forget about trailing . and .. */
/* Nuke any quotes */
for (i=1; src[i] == '"' || src[i] == '\''; i++)
;
if ( src[i] == '/' ) { /* ./ */
src += i+1;
break;
}
if ( src[i] == '\0' ) { /* .\0 */
src += i; /* only 1 so we don't fall off the end */
break;
}
if ( src[i] == '.' &&
(src[i+1] == '"' || src[i+1] == '\'')) { /* ..", ..' */
src += i+2;
break;
}
if ( src[i] == '.' && src[i+1] == '/' ) { /* ../ */
src += i+2;
break;
}
if ( src[i] == '.' && src[i+1] == '\0' ) { /* .. */
src += i+1; /* don't fall off the end */
break;
}
/* must be a filename - fall through */
default:
/* must be filename - copy it over */
while ( *src != '\0' && *src != '/')
/** Note quotes are taken care of by Gpopen **/
*dst++ = *src++;
break;
}
}
/* and terminate it */
*dst = '\0';
}
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