NetBSD/sbin/mount_tmpfs/mount_tmpfs.c

289 lines
7.2 KiB
C

/* $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