/*      $NetBSD: mount_tmpfs.c,v 1.29 2016/02/21 22:51:30 christos Exp $        */

/*
 * Copyright (c) 2005, 2006 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Julio M. Merino Vidal, developed as part of Google's Summer of Code
 * 2005 program.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``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 FOUNDATION OR CONTRIBUTORS
 * 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>
#ifndef lint
__RCSID("$NetBSD: mount_tmpfs.c,v 1.29 2016/02/21 22:51:30 christos Exp $");
#endif /* not lint */

#include <sys/param.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/sysctl.h>

#include <fs/tmpfs/tmpfs_args.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <grp.h>
#include <mntopts.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "mountprog.h"
#include "mount_tmpfs.h"

/* --------------------------------------------------------------------- */

static const struct mntopt mopts[] = {
        MOPT_UPDATE,
        MOPT_STDOPTS,
        MOPT_GETARGS,
        MOPT_NOATIME,
        MOPT_RELATIME,
        MOPT_NULL,
};

/* --------------------------------------------------------------------- */

static void     usage(void) __dead;
static int64_t  ram_fract(const char *arg);
static int64_t  ram_percent(const char *arg);
static int64_t  ram_factor(float f);

/* --------------------------------------------------------------------- */

/* return f * available system ram */
static int64_t
ram_factor(float f)
{
        uint64_t ram;
        size_t len;

        len = sizeof(ram);
        if (sysctlbyname("hw.physmem64", &ram, &len, NULL, 0))
                err(EXIT_FAILURE, "can't get \"hw.physmem64\"");

        return (int64_t)((float)ram * f);
}

/* return fraction of available ram given by arg */
static int64_t
ram_fract(const char *arg)
{
        char *endp;
        float f;

        f = strtof(arg, &endp);
        if (endp && *endp != 0)
                errx(EXIT_FAILURE, "syntax error in ram fraction: ram/%s"
                    " at %s", arg, endp);
        if (f <= 0.0f)
                errx(EXIT_FAILURE, "ram fraction must be a positive number:"
                     " ram/%s", arg);

        return ram_factor(1.0f/f);
}

/* --------------------------------------------------------------------- */

/* return percentage of available ram given by arg */
static int64_t
ram_percent(const char *arg)
{
        char *endp;
        float f;

        f = strtof(arg, &endp);
        if (endp && *endp != 0)
                errx(EXIT_FAILURE, "syntax error in ram percentage: ram%%%s"
                    " at %s", arg, endp);
        if (f <= 0.0f || f >= 100.0f)
                errx(EXIT_FAILURE, "ram percentage must be a between 0 and 100"
                     " ram%%%s", arg);

        return ram_factor(f/100.0f);
}

/* --------------------------------------------------------------------- */

void
mount_tmpfs_parseargs(int argc, char *argv[],
        struct tmpfs_args *args, int *mntflags,
        char *canon_dev, char *canon_dir)
{
        int gidset, modeset, uidset; /* Ought to be 'bool'. */
        int ch;
        gid_t gid;
        uid_t uid;
        mode_t mode;
        int64_t tmpnumber;
        mntoptparse_t mp;
        struct stat sb;

        /* Set default values for mount point arguments. */
        memset(args, 0, sizeof(*args));
        args->ta_version = TMPFS_ARGS_VERSION;
        args->ta_size_max = 0;
        args->ta_nodes_max = 0;
        *mntflags = 0;

        gidset = 0; gid = 0;
        uidset = 0; uid = 0;
        modeset = 0; mode = 0;

        optind = optreset = 1;
        while ((ch = getopt(argc, argv, "g:m:n:o:s:u:")) != -1 ) {
                switch (ch) {
                case 'g':
                        gid = a_gid(optarg);
                        gidset = 1;
                        break;

                case 'm':
                        mode = a_mask(optarg);
                        modeset = 1;
                        break;

                case 'n':
                        if (dehumanize_number(optarg, &tmpnumber) == -1)
                                err(EXIT_FAILURE, "failed to parse nodes `%s'",
                                    optarg);
                        args->ta_nodes_max = tmpnumber;
                        break;

                case 'o':
                        mp = getmntopts(optarg, mopts, mntflags, 0);
                        if (mp == NULL)
                                err(EXIT_FAILURE, "getmntopts");
                        freemntopts(mp);
                        break;

                case 's':
                        if (strncmp(optarg, "ram/", 4) == 0)
                                tmpnumber = ram_fract(optarg+4);
                        else if (strncmp(optarg, "ram%", 4) == 0)
                                tmpnumber = ram_percent(optarg+4);
                        else if (dehumanize_number(optarg, &tmpnumber) == -1)
                                err(EXIT_FAILURE, "failed to parse size `%s'",
                                    optarg);
                        args->ta_size_max = tmpnumber;
                        break;

                case 'u':
                        uid = a_uid(optarg);
                        uidset = 1;
                        break;

                case '?':
                default:
                        usage();
                }
        }
        argc -= optind;
        argv += optind;

        if (argc != 2)
                usage();

        strlcpy(canon_dev, argv[0], MAXPATHLEN);
        pathadj(argv[1], canon_dir);

        if (stat(canon_dir, &sb) == -1)
                err(EXIT_FAILURE, "cannot stat `%s'", canon_dir);

        args->ta_root_uid = uidset ? uid : sb.st_uid;
        args->ta_root_gid = gidset ? gid : sb.st_gid;
        args->ta_root_mode = modeset ? mode : sb.st_mode;
}

/* --------------------------------------------------------------------- */

static void
usage(void)
{
        (void)fprintf(stderr,
            "usage: %s [-g group] [-m mode] [-n nodes] [-o options] [-s size]\n"
            "           [-u user] tmpfs mount_point\n", getprogname());
        exit(1);
}

/* --------------------------------------------------------------------- */

int
mount_tmpfs(int argc, char *argv[])
{
        struct tmpfs_args args;
        char canon_dev[MAXPATHLEN], canon_dir[MAXPATHLEN];
        int mntflags;

        mount_tmpfs_parseargs(argc, argv, &args, &mntflags,
            canon_dev, canon_dir);

        if (mount(MOUNT_TMPFS, canon_dir, mntflags, &args, sizeof args) == -1)
                err(EXIT_FAILURE, "tmpfs on %s", canon_dir);

        if (mntflags & MNT_GETARGS) {
                struct passwd *pw;
                struct group *gr;

                (void)printf("version=%d, ", args.ta_version);
                (void)printf("size_max=%" PRIuMAX ", ",
                    (uintmax_t)args.ta_size_max);
                (void)printf("nodes_max=%" PRIuMAX ", ",
                    (uintmax_t)args.ta_nodes_max);

                pw = getpwuid(args.ta_root_uid);
                if (pw == NULL)
                        (void)printf("root_uid=%" PRIuMAX ", ",
                            (uintmax_t)args.ta_root_uid);
                else
                        (void)printf("root_uid=%s, ", pw->pw_name);

                gr = getgrgid(args.ta_root_gid);
                if (gr == NULL)
                        (void)printf("root_gid=%" PRIuMAX ", ",
                            (uintmax_t)args.ta_root_gid);
                else
                        (void)printf("root_gid=%s, ", gr->gr_name);

                (void)printf("root_mode=%o\n", args.ta_root_mode);
        }

        return EXIT_SUCCESS;
}

#ifndef MOUNT_NOMAIN
int
main(int argc, char *argv[])
{

        setprogname(argv[0]);
        return mount_tmpfs(argc, argv);
}
#endif