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/* Quintuple Agent
* Copyright (C) 1999 Robert Bihlmeyer <robbe@orcus.priv.at>
*
* 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, see <https://www.gnu.org/licenses/>.
* SPDX-License-Identifier: GPL-2.0+
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#define _GNU_SOURCE 1
#include <unistd.h>
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "util.h"
#ifndef HAVE_DOSISH_SYSTEM
static int uid_set = 0;
static uid_t real_uid, file_uid;
#endif /*!HAVE_DOSISH_SYSTEM*/
/* Write DATA of size BYTES to FD, until all is written or an error
occurs. */
ssize_t
xwrite(int fd, const void *data, size_t bytes)
{
char *ptr;
size_t todo;
ssize_t written = 0;
for (ptr = (char *)data, todo = bytes; todo; ptr += written, todo -= written)
{
do
written = write (fd, ptr, todo);
while (
written == -1 && errno == EINTR
);
if (written < 0)
break;
}
return written;
}
#if 0
extern int debug;
int
debugmsg(const char *fmt, ...)
{
va_list va;
int ret;
if (debug) {
va_start(va, fmt);
fprintf(stderr, "\e[4m");
ret = vfprintf(stderr, fmt, va);
fprintf(stderr, "\e[24m");
va_end(va);
return ret;
} else
return 0;
}
#endif
/* initialize uid variables */
#ifndef HAVE_DOSISH_SYSTEM
static void
init_uids(void)
{
real_uid = getuid();
file_uid = geteuid();
uid_set = 1;
}
#endif
/* drop all additional privileges */
void
drop_privs(void)
{
#ifndef HAVE_DOSISH_SYSTEM
if (!uid_set)
init_uids();
if (real_uid != file_uid) {
if (setuid(real_uid) < 0) {
perror("dropping privileges failed");
exit(EXIT_FAILURE);
}
file_uid = real_uid;
}
#endif
}
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