/*
 * (C) 2000-2006 by the netfilter coreteam <coreteam@netfilter.org>:
 *
 *	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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <dlfcn.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>

#include <iptables_common.h>
#include <xtables.h>

#ifndef PROC_SYS_MODPROBE
#define PROC_SYS_MODPROBE "/proc/sys/kernel/modprobe"
#endif

/* the path to command to load kernel module */
const char *modprobe = NULL;

void *fw_calloc(size_t count, size_t size)
{
	void *p;

	if ((p = calloc(count, size)) == NULL) {
		perror("ip[6]tables: calloc failed");
		exit(1);
	}

	return p;
}

void *fw_malloc(size_t size)
{
	void *p;

	if ((p = malloc(size)) == NULL) {
		perror("ip[6]tables: malloc failed");
		exit(1);
	}

	return p;
}

static char *get_modprobe(void)
{
	int procfile;
	char *ret;

#define PROCFILE_BUFSIZ	1024
	procfile = open(PROC_SYS_MODPROBE, O_RDONLY);
	if (procfile < 0)
		return NULL;

	ret = (char *) malloc(PROCFILE_BUFSIZ);
	if (ret) {
		memset(ret, 0, PROCFILE_BUFSIZ);
		switch (read(procfile, ret, PROCFILE_BUFSIZ)) {
		case -1: goto fail;
		case PROCFILE_BUFSIZ: goto fail; /* Partial read.  Wierd */
		}
		if (ret[strlen(ret)-1]=='\n') 
			ret[strlen(ret)-1]=0;
		close(procfile);
		return ret;
	}
 fail:
	free(ret);
	close(procfile);
	return NULL;
}

int xtables_insmod(const char *modname, const char *modprobe, int quiet)
{
	char *buf = NULL;
	char *argv[4];
	int status;

	/* If they don't explicitly set it, read out of kernel */
	if (!modprobe) {
		buf = get_modprobe();
		if (!buf)
			return -1;
		modprobe = buf;
	}

	switch (fork()) {
	case 0:
		argv[0] = (char *)modprobe;
		argv[1] = (char *)modname;
		if (quiet) {
			argv[2] = "-q";
			argv[3] = NULL;
		} else {
			argv[2] = NULL;
			argv[3] = NULL;
		}
		execv(argv[0], argv);

		/* not usually reached */
		exit(1);
	case -1:
		return -1;

	default: /* parent */
		wait(&status);
	}

	free(buf);
	if (WIFEXITED(status) && WEXITSTATUS(status) == 0)
		return 0;
	return -1;
}