mirror of
https://git.hardenedbsd.org/hardenedbsd/HardenedBSD.git
synced 2024-11-22 03:04:34 +01:00
110 lines
3.1 KiB
C
110 lines
3.1 KiB
C
/*
|
|
* Copyright (c) 1997 Shigio Yamaguchi. All rights reserved.
|
|
* Copyright (c) 1999 Tama Communications Corporation. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
#include <errno.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include "pathconv.h" /* prototypes */
|
|
/*
|
|
* abs2rel: convert an absolute path name into relative.
|
|
*
|
|
* i) path absolute path
|
|
* i) base base directory (must be absolute path)
|
|
* o) result result buffer
|
|
* i) size size of result buffer
|
|
* r) != NULL: relative path
|
|
* == NULL: error
|
|
*/
|
|
char *
|
|
abs2rel(const char *path, const char *base, char *result, const size_t size)
|
|
{
|
|
const char *pp, *bp, *branch;
|
|
/*
|
|
* endp points the last position which is safe in the result buffer.
|
|
*/
|
|
const char *endp = result + size - 1;
|
|
char *rp;
|
|
|
|
if (*path != '/') {
|
|
if (strlen(path) >= size)
|
|
goto erange;
|
|
strcpy(result, path);
|
|
goto finish;
|
|
} else if (*base != '/' || !size) {
|
|
errno = EINVAL;
|
|
return (NULL);
|
|
} else if (size == 1)
|
|
goto erange;
|
|
/*
|
|
* seek to branched point.
|
|
*/
|
|
branch = path;
|
|
for (pp = path, bp = base; *pp && *bp && *pp == *bp; pp++, bp++)
|
|
if (*pp == '/')
|
|
branch = pp;
|
|
if ((*pp == 0 || (*pp == '/' && *(pp + 1) == 0)) &&
|
|
(*bp == 0 || (*bp == '/' && *(bp + 1) == 0))) {
|
|
rp = result;
|
|
*rp++ = '.';
|
|
if (*pp == '/' || *(pp - 1) == '/')
|
|
*rp++ = '/';
|
|
if (rp > endp)
|
|
goto erange;
|
|
*rp = 0;
|
|
goto finish;
|
|
}
|
|
if ((*pp == 0 && *bp == '/') || (*pp == '/' && *bp == 0))
|
|
branch = pp;
|
|
/*
|
|
* up to root.
|
|
*/
|
|
rp = result;
|
|
for (bp = base + (branch - path); *bp; bp++)
|
|
if (*bp == '/' && *(bp + 1) != 0) {
|
|
if (rp + 3 > endp)
|
|
goto erange;
|
|
*rp++ = '.';
|
|
*rp++ = '.';
|
|
*rp++ = '/';
|
|
}
|
|
if (rp > endp)
|
|
goto erange;
|
|
*rp = 0;
|
|
/*
|
|
* down to leaf.
|
|
*/
|
|
if (*branch) {
|
|
if (rp + strlen(branch + 1) > endp)
|
|
goto erange;
|
|
strcpy(rp, branch + 1);
|
|
} else
|
|
*--rp = 0;
|
|
finish:
|
|
return result;
|
|
erange:
|
|
errno = ERANGE;
|
|
return (NULL);
|
|
}
|