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/* path.c - Routines for manipulating path strings
* Copyright (C) 2001 Bruce Guenter <bruceg@em.ca>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include "twoftpd.h"
#include "backend.h"
#include <path/path.h>
str fullpath;
static int validate_fullpath(void)
{
errno = EPERM;
if (lockhome) {
unsigned long homelen = strlen(home);
if (memcmp(fullpath.s, home, homelen) != 0 ||
(fullpath.s[homelen] != 0 && fullpath.s[homelen] != '/'))
return 0;
}
if (nodotfiles) {
long i;
if (fullpath.s[0] == '.') return 0;
if (fullpath.s[0] == '/' && fullpath.s[1] == '.') return 0;
for (i = str_findlast(&fullpath, '/'); i > 0;
i = str_findprev(&fullpath, '/', i-1))
if (fullpath.s[i+1] == '.') return 0;
}
errno = 0;
return 1;
}
static int qualify(const char* path)
{
if (!str_copy(&fullpath, &cwd)) return 0;
if (!path_merge(&fullpath, path)) return 0;
return 1;
}
int qualify_validate(const char* path)
{
if (!qualify(path)) {
respond_internal_error();
return 0;
}
if (!validate_fullpath()) {
respond_permission_denied();
return 0;
}
return 1;
}
static int open_fd(const char* filename, int flags, int mode)
{
int fd;
struct stat st;
if (!qualify(filename)) return -1;
if (!validate_fullpath()) return -1;
if ((fd = open(fullpath.s+1, flags, mode)) == -1) return -1;
if (fstat(fd, &st) == 0) {
if (S_ISREG(st.st_mode))
return fd;
else
errno = EPERM;
}
close(fd);
return -1;
}
int open_in(ibuf* in, const char* filename)
{
int fd;
if ((fd = open_fd(filename, O_RDONLY, 0)) == -1) return 0;
if (ibuf_init(in, fd, 0, IOBUF_NEEDSCLOSE, 0)) return 1;
close(fd);
return 0;
}
int open_out(obuf* out, const char* filename, int flags)
{
int fd;
if ((fd = open_fd(filename, O_WRONLY | flags, 0666)) == -1) return 0;
if (obuf_init(out, fd, 0, IOBUF_NEEDSCLOSE, 0)) return 1;
close(fd);
return 0;
}
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