/*

 * kmod-remove - remove modules from the kernel.

 *

 * Copyright (C) 2015 Intel Corporation. All rights reserved.

 * Copyright (C) 2011-2013  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 <errno.h>

#include <getopt.h>

#include <stdlib.h>

#include <string.h>

#include <libkmod/libkmod.h>

#include "kmod.h"

static const char cmdopts_s[] = "h";

static const struct option cmdopts[] = {

	{"help", no_argument, 0, 'h'},

	{ }

};

static void help(void)

{

	printf("Usage:\n"

	       "\t%s remove [options] module\n"

	       "Options:\n"

	       "\t-h, --help        show this help\n",

	       program_invocation_short_name);

}

static int check_module_inuse(struct kmod_module *mod) {

	struct kmod_list *holders;

	int state;

	state = kmod_module_get_initstate(mod);

	if (state == KMOD_MODULE_BUILTIN) {

		ERR("Module %s is builtin.\n", kmod_module_get_name(mod));

		return -ENOENT;

	} else if (state < 0) {

		ERR("Module %s is not currently loaded\n",

				kmod_module_get_name(mod));

		return -ENOENT;

	}

	holders = kmod_module_get_holders(mod);

	if (holders != NULL) {

		struct kmod_list *itr;

		ERR("Module %s is in use by:", kmod_module_get_name(mod));

		kmod_list_foreach(itr, holders) {

			struct kmod_module *hm = kmod_module_get_module(itr);

			fprintf(stderr, " %s", kmod_module_get_name(hm));

			kmod_module_unref(hm);

		}

		fputc('\n', stderr);

		kmod_module_unref_list(holders);

		return -EBUSY;

	}

	if (kmod_module_get_refcnt(mod) != 0) {

		ERR("Module %s is in use\n", kmod_module_get_name(mod));

		return -EBUSY;

	}

	return 0;

}

static int do_remove(int argc, char *argv[])

{

	struct kmod_ctx *ctx;

	struct kmod_module *mod;

	const char *name;

	int err, r = EXIT_SUCCESS;

	for (;;) {

		int c, idx =0;

		c = getopt_long(argc, argv, cmdopts_s, cmdopts, &idx);

		if (c == -1)

			break;

		switch (c) {

		case 'h':

			help();

			return EXIT_SUCCESS;

		default:

			ERR("Unexpected getopt_long() value '%c'.\n", c);

			return EXIT_FAILURE;

		}

	}

	if (optind >= argc) {

		ERR("Missing module name\n");

		return EXIT_FAILURE;

	}

	ctx = kmod_new(NULL, NULL);

	if (!ctx) {

		ERR("kmod_new() failed!\n");

		return EXIT_FAILURE;

	}

	name = argv[optind];

	err = kmod_module_new_from_name(ctx, name, &mod);

	if (err < 0) {

		ERR("Could not remove module %s: %s\n", name, strerror(-err));

		goto end;

	}

	err = check_module_inuse(mod);

	if (err < 0)

		goto unref;

	err = kmod_module_remove_module(mod, 0);

	if (err < 0)

		goto unref;

unref:

	kmod_module_unref(mod);

end:

	kmod_unref(ctx);

	if (err < 0) {

		r = EXIT_FAILURE;

		ERR("Could not remove module %s: %s\n", name, strerror(-err));

	}

	return r;

}

const struct kmod_cmd kmod_cmd_remove = {

	.name = "remove",

	.cmd = do_remove,

	.help = "remove module from kernel",

};