/*      $NetBSD: refuse_lowlevel.c,v 1.4 2022/01/22 08:09:39 pho Exp $  */

/*
 * Copyright (c) 2016 The NetBSD Foundation, Inc.
 * 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. The name of the author 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.
 */

#include <sys/cdefs.h>
#if !defined(lint)
__RCSID("$NetBSD: refuse_lowlevel.c,v 1.4 2022/01/22 08:09:39 pho Exp $");
#endif /* !lint */

#include <fuse_internal.h>
#include <fuse_opt.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define REFUSE_LOWLEVEL_OPT(t, p, v) \
        { t, offsetof(struct fuse_cmdline_opts, p), v }

static struct fuse_opt fuse_lowlevel_opts[] = {
        REFUSE_LOWLEVEL_OPT("-h"       , show_help       , REFUSE_SHOW_HELP_FULL),
        REFUSE_LOWLEVEL_OPT("--help"   , show_help       , REFUSE_SHOW_HELP_FULL),
        REFUSE_LOWLEVEL_OPT("-ho"      , show_help       , REFUSE_SHOW_HELP_NO_HEADER),
        REFUSE_LOWLEVEL_OPT("-V"       , show_version    , 1),
        REFUSE_LOWLEVEL_OPT("--version", show_version    , 1),
        REFUSE_LOWLEVEL_OPT("-d"       , debug           , 1),
        REFUSE_LOWLEVEL_OPT("debug"    , debug           , 1),
        REFUSE_LOWLEVEL_OPT("-d"       , foreground      , 1),
        REFUSE_LOWLEVEL_OPT("debug"    , foreground      , 1),
        REFUSE_LOWLEVEL_OPT("-f"       , foreground      , 1),
        REFUSE_LOWLEVEL_OPT("-s"       , singlethread    , 1),
        REFUSE_LOWLEVEL_OPT("fsname="  , nodefault_fsname, 1),
        FUSE_OPT_KEY       ("fsname="  , FUSE_OPT_KEY_KEEP  ),
        FUSE_OPT_END
};

void fuse_lowlevel_version(void)
{
        /* XXX: Print something */
}

void fuse_cmdline_help(void)
{
        printf("refuse options:\n"
                   "    -d, -o debug    enable debug output, implies -f\n"
                   "    -f              foreground mode\n"
                   "    -s              single threaded mode (always enabled for now)\n"
                   "    -o fsname=NAME  explicitly set the name of the file system\n");
}

static int refuse_lowlevel_opt_proc(void* data, const char *arg, int key,
                                                                        struct fuse_args *outargs)
{
        struct fuse_cmdline_opts *opts = data;

        switch (key) {
        case FUSE_OPT_KEY_NONOPT:
                if (opts->mountpoint == NULL) {
                        return fuse_opt_add_opt(&opts->mountpoint, arg);
                }
                else {
                        (void)fprintf(stderr, "fuse: invalid argument: %s\n", arg);
                        return -1;
                }

        default:
                return 1; /* keep the argument */
        }
}

static int add_default_fsname(struct fuse_args *args)
{
        const char *arg0 = args->argv[0];
        const char *slash;

        if (arg0 == NULL || arg0[0] == '\0') {
                return fuse_opt_add_arg(args, "-ofsname=refuse");
        } else {
                char *arg;
                int rv;

                if ((slash = strrchr(arg0, '/')) == NULL) {
                        slash = arg0;
                } else {
                        slash += 1;
                }

                if (asprintf(&arg, "-ofsname=refuse:%s", slash) == -1)
                        return -1;

                rv = fuse_opt_add_arg(args, arg);
                free(arg);
                return rv;
        }
}

int
__fuse_parse_cmdline(struct fuse_args *args, struct fuse_cmdline_opts *opts)
{
        memset(opts, 0, sizeof(*opts));

        /*
         * XXX: The single threaded mode is always enabled and cannot be
         * disabled. This is because puffs currently does not support
         * multithreaded operation.
         */
        opts->singlethread = 1;

        if (fuse_opt_parse(args, opts, fuse_lowlevel_opts,
                                           refuse_lowlevel_opt_proc) == -1)
                return -1;

        if (!opts->nodefault_fsname) {
                /* -o fsname=%s is not specified so add a default fsname
                 * generated from the program basename.
                 */
                if (add_default_fsname(args) == -1)
                        return -1;
        }

        return 0;
}