/*

 * kmod-rmmod - remove modules from linux kernel using libkmod.

 *

 * 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 <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <shared/macro.h>

#include <libkmod/libkmod.h>

#include "kmod.h"

#define DEFAULT_VERBOSE LOG_ERR

static int verbose = DEFAULT_VERBOSE;

static int use_syslog;

static const char cmdopts_s[] = "fsvVwh";

static const struct option cmdopts[] = {

	{"force", no_argument, 0, 'f'},

	{"syslog", no_argument, 0, 's'},

	{"verbose", no_argument, 0, 'v'},

	{"version", no_argument, 0, 'V'},

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

	{NULL, 0, 0, 0}

};

static void help(void)

{

	printf("Usage:\n"

		"\t%s [options] modulename ...\n"

		"Options:\n"

		"\t-f, --force       forces a module unload and may crash your\n"

		"\t                  machine. This requires Forced Module Removal\n"

		"\t                  option in your kernel. DANGEROUS\n"

		"\t-s, --syslog      print to syslog, not stderr\n"

		"\t-v, --verbose     enables more messages\n"

		"\t-V, --version     show version\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_rmmod(int argc, char *argv[])

{

	struct kmod_ctx *ctx;

	const char *null_config = NULL;

	int flags = 0;

	int i, err, r = 0;

	for (;;) {

		int c, idx = 0;

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

		if (c == -1)

			break;

		switch (c) {

		case 'f':

			flags |= KMOD_REMOVE_FORCE;

			break;

		case 's':

			use_syslog = 1;

			break;

		case 'v':

			verbose++;

			break;

		case 'h':

			help();

			return EXIT_SUCCESS;

		case 'V':

			puts(PACKAGE " version " VERSION);

			puts(KMOD_FEATURES);

			return EXIT_SUCCESS;

		case '?':

			return EXIT_FAILURE;

		default:

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

			return EXIT_FAILURE;

		}

	}

	log_open(use_syslog);

	if (optind >= argc) {

		ERR("missing module name.\n");

		r = EXIT_FAILURE;

		goto done;

	}

	ctx = kmod_new(NULL, &null_config);

	if (!ctx) {

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

		r = EXIT_FAILURE;

		goto done;

	}

	log_setup_kmod_log(ctx, verbose);

	for (i = optind; i < argc; i++) {

		struct kmod_module *mod;

		const char *arg = argv[i];

		struct stat st;

		if (stat(arg, &st) == 0)

			err = kmod_module_new_from_path(ctx, arg, &mod);

		else

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

		if (err < 0) {

			ERR("could not use module %s: %s\n", arg,

			    strerror(-err));

			break;

		}

		if (!(flags & KMOD_REMOVE_FORCE) && check_module_inuse(mod) < 0) {

			r++;

			goto next;

		}

		err = kmod_module_remove_module(mod, flags);

		if (err < 0) {

			ERR("could not remove module %s: %s\n", arg,

			    strerror(-err));

			r++;

		}

next:

		kmod_module_unref(mod);

	}

	kmod_unref(ctx);

done:

	log_close();

	return r == 0 ? EXIT_SUCCESS : EXIT_FAILURE;

}

const struct kmod_cmd kmod_cmd_compat_rmmod = {

	.name = "rmmod",

	.cmd = do_rmmod,

	.help = "compat rmmod command",

};