busybox/mount.c
2000-04-28 00:18:56 +00:00

495 lines
13 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Mini mount implementation for busybox
*
* Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
*
* 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* 3/21/1999 Charles P. Wright <cpwright@cpwright.com>
* searches through fstab when -a is passed
* will try mounting stuff with all fses when passed -t auto
*
* 1999-04-17 Dave Cinege...Rewrote -t auto. Fixed ro mtab.
*
* 1999-10-07 Erik Andersen <andersen@lineo.com>, <andersee@debian.org>.
* Rewrite of a lot of code. Removed mtab usage (I plan on
* putting it back as a compile-time option some time),
* major adjustments to option parsing, and some serious
* dieting all around.
*
* 1999-11-06 mtab suppport is back - andersee
*
* 2000-01-12 Ben Collins <bcollins@debian.org>, Borrowed utils-linux's
* mount to add loop support.
*/
#include "internal.h"
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <mntent.h>
#include <sys/mount.h>
#include <ctype.h>
#if defined BB_FEATURE_USE_DEVPS_PATCH
#include <linux/devmtab.h>
#endif
#ifndef MS_RDONLY
#include <linux/fs.h>
#endif
#if defined BB_FEATURE_MOUNT_LOOP
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/loop.h>
static int use_loop = FALSE;
#endif
extern const char mtab_file[]; /* Defined in utility.c */
static const char mount_usage[] = "\tmount [flags]\n"
"\tmount [flags] device directory [-o options,more-options]\n"
"\n" "Flags:\n" "\t-a:\tMount all file systems in fstab.\n"
#ifdef BB_MTAB
"\t-f:\t\"Fake\" mount. Add entry to mount table but don't mount it.\n"
"\t-n:\tDon't write a mount table entry.\n"
#endif
"\t-o option:\tOne of many filesystem options, listed below.\n"
"\t-r:\tMount the filesystem read-only.\n"
"\t-t filesystem-type:\tSpecify the filesystem type.\n"
"\t-w:\tMount for reading and writing (default).\n"
"\n"
"Options for use with the \"-o\" flag:\n"
"\tasync / sync:\tWrites are asynchronous / synchronous.\n"
"\tdev / nodev:\tAllow use of special device files / disallow them.\n"
"\texec / noexec:\tAllow use of executable files / disallow them.\n"
#if defined BB_FEATURE_MOUNT_LOOP
"\tloop: Mounts a file via loop device.\n"
#endif
"\tsuid / nosuid:\tAllow set-user-id-root programs / disallow them.\n"
"\tremount: Re-mount a currently-mounted filesystem, changing its flags.\n"
"\tro / rw: Mount for read-only / read-write.\n"
"There are EVEN MORE flags that are specific to each filesystem.\n"
"You'll have to see the written documentation for those.\n";
struct mount_options {
const char *name;
unsigned long and;
unsigned long or;
};
static const struct mount_options mount_options[] = {
{"async", ~MS_SYNCHRONOUS, 0},
{"defaults", ~0, 0},
{"dev", ~MS_NODEV, 0},
{"exec", ~MS_NOEXEC, 0},
{"nodev", ~0, MS_NODEV},
{"noexec", ~0, MS_NOEXEC},
{"nosuid", ~0, MS_NOSUID},
{"remount", ~0, MS_REMOUNT},
{"ro", ~0, MS_RDONLY},
{"rw", ~MS_RDONLY, 0},
{"suid", ~MS_NOSUID, 0},
{"sync", ~0, MS_SYNCHRONOUS},
{0, 0, 0}
};
static int
do_mount(char *specialfile, char *dir, char *filesystemtype,
long flags, void *string_flags, int useMtab, int fakeIt,
char *mtab_opts)
{
int status = 0;
char *lofile = NULL;
#if defined BB_MTAB
if (fakeIt == FALSE)
#endif
{
#if defined BB_FEATURE_MOUNT_LOOP
if (use_loop==TRUE) {
int loro = flags & MS_RDONLY;
char *lofile = specialfile;
specialfile = find_unused_loop_device();
if (specialfile == NULL) {
fprintf(stderr, "Could not find a spare loop device\n");
return (FALSE);
}
if (set_loop(specialfile, lofile, 0, &loro)) {
fprintf(stderr, "Could not setup loop device\n");
return (FALSE);
}
if (!(flags & MS_RDONLY) && loro) { /* loop is ro, but wanted rw */
fprintf(stderr, "WARNING: loop device is read-only\n");
flags &= ~MS_RDONLY;
}
}
#endif
status =
mount(specialfile, dir, filesystemtype, flags, string_flags);
}
/* If the mount was sucessful, do anything needed, then return TRUE */
if (status == 0) {
#if defined BB_MTAB
if (useMtab == TRUE) {
write_mtab(specialfile, dir, filesystemtype, flags, mtab_opts);
}
#endif
return (TRUE);
}
/* Bummer. mount failed. Clean up */
#if defined BB_FEATURE_MOUNT_LOOP
if (lofile != NULL) {
del_loop(specialfile);
}
#endif
return (FALSE);
}
/* Seperate standard mount options from the nonstandard string options */
static void
parse_mount_options(char *options, unsigned long *flags, char *strflags)
{
while (options) {
int gotone = FALSE;
char *comma = strchr(options, ',');
const struct mount_options *f = mount_options;
if (comma)
*comma = '\0';
while (f->name != 0) {
if (strcasecmp(f->name, options) == 0) {
*flags &= f->and;
*flags |= f->or;
gotone = TRUE;
break;
}
f++;
}
#if defined BB_FEATURE_MOUNT_LOOP
if (gotone == FALSE && !strcasecmp("loop", options)) { /* loop device support */
use_loop = TRUE;
gotone = TRUE;
}
#endif
if (*strflags && strflags != '\0' && gotone == FALSE) {
char *temp = strflags;
temp += strlen(strflags);
*temp++ = ',';
*temp++ = '\0';
}
if (gotone == FALSE)
strcat(strflags, options);
if (comma) {
*comma = ',';
options = ++comma;
} else {
break;
}
}
}
int
mount_one(char *blockDevice, char *directory, char *filesystemType,
unsigned long flags, char *string_flags, int useMtab, int fakeIt,
char *mtab_opts, int whineOnErrors)
{
int status = 0;
#if defined BB_FEATURE_USE_PROCFS
char buf[255];
if (strcmp(filesystemType, "auto") == 0) {
FILE *f = fopen("/proc/filesystems", "r");
if (f == NULL)
return (FALSE);
while (fgets(buf, sizeof(buf), f) != NULL) {
filesystemType = buf;
if (*filesystemType == '\t') { // Not a nodev filesystem
// Add NULL termination to each line
while (*filesystemType && *filesystemType != '\n')
filesystemType++;
*filesystemType = '\0';
filesystemType = buf;
filesystemType++; // hop past tab
status = do_mount(blockDevice, directory, filesystemType,
flags | MS_MGC_VAL, string_flags,
useMtab, fakeIt, mtab_opts);
if (status == TRUE)
break;
}
}
fclose(f);
} else
#endif
#if defined BB_FEATURE_USE_DEVPS_PATCH
if (strcmp(filesystemType, "auto") == 0) {
int fd, i, numfilesystems;
char device[] = "/dev/mtab";
struct k_fstype *fslist;
/* open device */
fd = open(device, O_RDONLY);
if (fd < 0)
fatalError("open failed for `%s': %s\n", device, strerror (errno));
/* How many filesystems? We need to know to allocate enough space */
numfilesystems = ioctl (fd, DEVMTAB_COUNT_FILESYSTEMS);
if (numfilesystems<0)
fatalError("\nDEVMTAB_COUNT_FILESYSTEMS: %s\n", strerror (errno));
fslist = (struct k_fstype *) calloc ( numfilesystems, sizeof(struct k_fstype));
/* Grab the list of available filesystems */
status = ioctl (fd, DEVMTAB_GET_FILESYSTEMS, fslist);
if (status<0)
fatalError("\nDEVMTAB_GET_FILESYSTEMS: %s\n", strerror (errno));
/* Walk the list trying to mount filesystems
* that do not claim to be nodev filesystems */
for( i = 0 ; i < numfilesystems ; i++) {
if (fslist[i].mnt_nodev)
continue;
status = do_mount(blockDevice, directory, fslist[i].mnt_type,
flags | MS_MGC_VAL, string_flags,
useMtab, fakeIt, mtab_opts);
if (status == TRUE)
break;
}
free( fslist);
close(fd);
} else
#endif
{
status = do_mount(blockDevice, directory, filesystemType,
flags | MS_MGC_VAL, string_flags, useMtab,
fakeIt, mtab_opts);
}
if (status == FALSE && whineOnErrors == TRUE) {
if (whineOnErrors == TRUE) {
fprintf(stderr, "Mounting %s on %s failed: %s\n",
blockDevice, directory, strerror(errno));
}
return (FALSE);
}
return (TRUE);
}
extern int mount_main(int argc, char **argv)
{
char string_flags_buf[1024] = "";
char *string_flags = string_flags_buf;
char *extra_opts = string_flags_buf;
unsigned long flags = 0;
char *filesystemType = "auto";
char *device = NULL;
char *directory = NULL;
int all = FALSE;
int fakeIt = FALSE;
int useMtab = TRUE;
int i;
#if defined BB_FEATURE_USE_DEVPS_PATCH
if (argc == 1) {
int fd, i, numfilesystems;
char device[] = "/dev/mtab";
struct k_mntent *mntentlist;
/* open device */
fd = open(device, O_RDONLY);
if (fd < 0)
fatalError("open failed for `%s': %s\n", device, strerror (errno));
/* How many mounted filesystems? We need to know to
* allocate enough space for later... */
numfilesystems = ioctl (fd, DEVMTAB_COUNT_MOUNTS);
if (numfilesystems<0)
fatalError( "\nDEVMTAB_COUNT_MOUNTS: %s\n", strerror (errno));
mntentlist = (struct k_mntent *) calloc ( numfilesystems, sizeof(struct k_mntent));
/* Grab the list of mounted filesystems */
if (ioctl (fd, DEVMTAB_GET_MOUNTS, mntentlist)<0)
fatalError( "\nDEVMTAB_GET_MOUNTS: %s\n", strerror (errno));
for( i = 0 ; i < numfilesystems ; i++) {
fprintf( stdout, "%s %s %s %s %d %d\n", mntentlist[i].mnt_fsname,
mntentlist[i].mnt_dir, mntentlist[i].mnt_type,
mntentlist[i].mnt_opts, mntentlist[i].mnt_freq,
mntentlist[i].mnt_passno);
}
/* Don't bother to close files or free memory. Exit
* does that automagically, so we can save a few bytes */
#if 0
free( mntentlist);
close(fd);
#endif
exit(TRUE);
}
#else
if (argc == 1) {
FILE *mountTable = setmntent(mtab_file, "r");
if (mountTable) {
struct mntent *m;
while ((m = getmntent(mountTable)) != 0) {
char *blockDevice = m->mnt_fsname;
if (strcmp(blockDevice, "/dev/root") == 0) {
find_real_root_device_name( blockDevice);
}
printf("%s on %s type %s (%s)\n", blockDevice, m->mnt_dir,
m->mnt_type, m->mnt_opts);
}
endmntent(mountTable);
} else {
perror(mtab_file);
}
exit(TRUE);
}
#endif
/* Parse options */
i = --argc;
argv++;
while (i > 0 && **argv) {
if (**argv == '-') {
char *opt = *argv;
while (i > 0 && *++opt)
switch (*opt) {
case 'o':
if (--i == 0) {
goto goodbye;
}
parse_mount_options(*(++argv), &flags, string_flags);
break;
case 'r':
flags |= MS_RDONLY;
break;
case 't':
if (--i == 0) {
goto goodbye;
}
filesystemType = *(++argv);
break;
case 'w':
flags &= ~MS_RDONLY;
break;
case 'a':
all = TRUE;
break;
case 'f':
fakeIt = TRUE;
break;
#ifdef BB_MTAB
case 'n':
useMtab = FALSE;
break;
#endif
case 'v':
break; /* ignore -v */
case 'h':
case '-':
goto goodbye;
}
} else {
if (device == NULL)
device = *argv;
else if (directory == NULL)
directory = *argv;
else {
goto goodbye;
}
}
i--;
argv++;
}
if (all == TRUE) {
struct mntent *m;
FILE *f = setmntent("/etc/fstab", "r");
if (f == NULL)
fatalError( "\nCannot read /etc/fstab: %s\n", strerror (errno));
while ((m = getmntent(f)) != NULL) {
// If the file system isn't noauto,
// and isn't swap or nfs, then mount it
if ((!strstr(m->mnt_opts, "noauto")) &&
(!strstr(m->mnt_type, "swap")) &&
(!strstr(m->mnt_type, "nfs"))) {
flags = 0;
*string_flags = '\0';
parse_mount_options(m->mnt_opts, &flags, string_flags);
/* If the directory is /, try to remount
* with the options specified in fstab */
if (m->mnt_dir[0] == '/' && m->mnt_dir[1] == '\0') {
flags |= MS_REMOUNT;
}
if (mount_one(m->mnt_fsname, m->mnt_dir, m->mnt_type,
flags, string_flags, useMtab, fakeIt,
extra_opts, FALSE))
{
/* Try again, but this time try a remount */
mount_one(m->mnt_fsname, m->mnt_dir, m->mnt_type,
flags|MS_REMOUNT, string_flags, useMtab, fakeIt,
extra_opts, TRUE);
}
}
}
endmntent(f);
} else {
if (device && directory) {
#ifdef BB_NFSMOUNT
if (strcmp(filesystemType, "nfs") == 0) {
if (nfsmount
(device, directory, &flags, &extra_opts, &string_flags,
1) != 0)
exit(FALSE);
}
#endif
exit(mount_one(device, directory, filesystemType,
flags, string_flags, useMtab, fakeIt,
extra_opts, TRUE));
} else {
goto goodbye;
}
}
exit(TRUE);
goodbye:
usage(mount_usage);
}