/*
 * load kernel modules
 *
 * Copyright (C) 2011 Kay Sievers <kay.sievers@vrfy.org>
 * Copyright (C) 2011 ProFUSION embedded systems
 *
 * 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 <http://www.gnu.org/licenses/>.
 */

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

#include "udev.h"

static struct kmod_ctx *ctx;

static int load_module(struct udev *udev, const char *alias)
{
	struct kmod_list *list = NULL;
	struct kmod_list *listb = NULL;
	struct kmod_list *l;
	int err;

	err = kmod_module_new_from_lookup(ctx, alias, &list);
	if (err < 0)
		return err;

	err = kmod_module_get_filtered_blacklist(ctx, list, &listb);
	if (err < 0)
		return err;

	if (list == NULL)
		info(udev, "no module matches '%s'\n", alias);

	kmod_list_foreach(l, listb) {
		struct kmod_module *mod = kmod_module_get_module(l);

		err = kmod_module_probe_insert_module(mod, 0, NULL, NULL, NULL);
		if (err >=0 )
			info(udev, "inserted '%s'\n", kmod_module_get_name(mod));
		else
			info(udev, "failed to insert '%s'\n", kmod_module_get_name(mod));

		kmod_module_unref(mod);
	}

	kmod_module_unref_list(list);
	kmod_module_unref_list(listb);
	return err;
}

static void udev_kmod_log(void *data, int priority, const char *file, int line,
			  const char *fn, const char *format, va_list args)
{
	udev_main_log(data, priority, file, line, fn, format, args);
}

/* needs to re-instantiate the context after a reload */
static int builtin_kmod(struct udev_device *dev, int argc, char *argv[], bool test)
{
	struct udev *udev = udev_device_get_udev(dev);
	int i;

	if (!ctx) {
		ctx = kmod_new(NULL, NULL);
		if (!ctx)
			return -ENOMEM;

		info(udev, "load module index\n");
		kmod_set_log_fn(ctx, udev_kmod_log, udev);
		kmod_load_resources(ctx);
	}

	if (argc < 3 || strcmp(argv[1], "load")) {
		err(udev, "expect: %s load <module>\n", argv[0]);
		return EXIT_FAILURE;
	}

	for (i = 2; argv[i]; i++) {
		info(udev, "execute '%s' '%s'\n", argv[1], argv[i]);
		load_module(udev, argv[i]);
	}

	return EXIT_SUCCESS;
}

/* called at udev startup */
static int builtin_kmod_init(struct udev *udev)
{
	if (ctx)
		return 0;

	ctx = kmod_new(NULL, NULL);
	if (!ctx)
		return -ENOMEM;

	info(udev, "load module index\n");
	kmod_set_log_fn(ctx, udev_kmod_log, udev);
	kmod_load_resources(ctx);
	return 0;
}

/* called on udev shutdown and reload request */
static void builtin_kmod_exit(struct udev *udev)
{
	ctx = kmod_unref(ctx);
	info(udev, "unload module index\n");
}

/* called every couple of seconds during event activity; 'true' if config has changed */
static bool builtin_kmod_validate(struct udev *udev)
{
	info(udev, "validate module index\n");
	return false;
}

const struct udev_builtin udev_builtin_kmod = {
	.name = "kmod",
	.cmd = builtin_kmod,
	.init = builtin_kmod_init,
	.exit = builtin_kmod_exit,
	.validate = builtin_kmod_validate,
	.help = "kernel module loader",
	.run_once = false,
};