71d6ccd801
if we don't zero it after closing it we re-close a filehandle that isn't open, and since this is a file _pointer_ it segfaults on a double free. Yeah, subtle bug. I need to break this out into separate functions if I can figure out how to avoid making the code larger while doing so. Part of the general -a and -o remount work I need to do, but that's after 1.1.0...
387 lines
10 KiB
C
387 lines
10 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
* Mini mount implementation for busybox
|
|
*
|
|
* Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
|
|
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
|
|
* Copyright (C) 2005 by Rob Landley <rob@landley.net>
|
|
*
|
|
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
|
|
*/
|
|
|
|
#include <limits.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#include <errno.h>
|
|
#include <string.h>
|
|
#include <stdio.h>
|
|
#include <mntent.h>
|
|
#include <ctype.h>
|
|
#include <sys/mount.h>
|
|
#include <fcntl.h> // for CONFIG_FEATURE_MOUNT_LOOP
|
|
#include <sys/ioctl.h> // for CONFIG_FEATURE_MOUNT_LOOP
|
|
#include "busybox.h"
|
|
|
|
// These two aren't always defined in old headers
|
|
#ifndef MS_BIND
|
|
#define MS_BIND 4096
|
|
#endif
|
|
#ifndef MS_MOVE
|
|
#define MS_MOVE 8192
|
|
#endif
|
|
|
|
/* Consume standard mount options (from -o options or --options).
|
|
* Set appropriate flags and collect unrecognized ones as a comma separated
|
|
* string to pass to kernel */
|
|
|
|
struct {
|
|
const char *name;
|
|
long flags;
|
|
} static const mount_options[] = {
|
|
{"loop", 0},
|
|
{"defaults", 0},
|
|
{"noauto", 0},
|
|
{"ro", MS_RDONLY},
|
|
{"rw", ~MS_RDONLY},
|
|
{"nosuid", MS_NOSUID},
|
|
{"suid", ~MS_NOSUID},
|
|
{"dev", ~MS_NODEV},
|
|
{"nodev", MS_NODEV},
|
|
{"exec", ~MS_NOEXEC},
|
|
{"noexec", MS_NOEXEC},
|
|
{"sync", MS_SYNCHRONOUS},
|
|
{"async", ~MS_SYNCHRONOUS},
|
|
{"remount", MS_REMOUNT},
|
|
{"atime", ~MS_NOATIME},
|
|
{"noatime", MS_NOATIME},
|
|
{"diratime", ~MS_NODIRATIME},
|
|
{"nodiratime", MS_NODIRATIME},
|
|
{"bind", MS_BIND},
|
|
{"move", MS_MOVE}
|
|
};
|
|
|
|
/* Uses the mount_options list above */
|
|
static void parse_mount_options(char *options, int *flags, char **strflags)
|
|
{
|
|
// Loop through options
|
|
for(;;) {
|
|
int i;
|
|
char *comma = strchr(options, ',');
|
|
|
|
if(comma) *comma = 0;
|
|
|
|
// Find this option in mount_options
|
|
for(i = 0; i < (sizeof(mount_options) / sizeof(*mount_options)); i++) {
|
|
if(!strcasecmp(mount_options[i].name, options)) {
|
|
long fl = mount_options[i].flags;
|
|
if(fl < 0) *flags &= fl;
|
|
else *flags |= fl;
|
|
break;
|
|
}
|
|
}
|
|
// Unrecognized mount option?
|
|
if(i == (sizeof(mount_options) / sizeof(*mount_options))) {
|
|
// Add it to strflags, to pass on to kernel
|
|
i = *strflags ? strlen(*strflags) : 0;
|
|
*strflags = xrealloc(*strflags, i+strlen(options)+2);
|
|
// Comma separated if it's not the first one
|
|
if(i) (*strflags)[i++] = ',';
|
|
strcpy((*strflags)+i, options);
|
|
}
|
|
// Advance to next option, or finish
|
|
if(comma) {
|
|
*comma = ',';
|
|
options = ++comma;
|
|
} else break;
|
|
}
|
|
}
|
|
|
|
/* This does the work */
|
|
|
|
extern int mount_main(int argc, char **argv)
|
|
{
|
|
char *string_flags = 0, *fsType = 0, *blockDevice = 0, *directory = 0,
|
|
*loopFile = 0, *buf = 0,
|
|
*files[] = {"/etc/filesystems", "/proc/filesystems", 0};
|
|
int i, opt, all = FALSE, fakeIt = FALSE, allowWrite = FALSE,
|
|
rc = 1, useMtab = ENABLE_FEATURE_MTAB_SUPPORT;
|
|
int flags=0xc0ed0000; // Needed for linux 2.2, ignored by 2.4 and 2.6.
|
|
FILE *file = 0,*f = 0;
|
|
char path[PATH_MAX*2];
|
|
struct mntent m;
|
|
struct stat statbuf;
|
|
|
|
/* parse long options, like --bind and --move. Note that -o option
|
|
* and --option are synonymous. Yes, this means --remount,rw works. */
|
|
|
|
for(i = opt = 0; i < argc; i++) {
|
|
if(argv[i][0] == '-' && argv[i][1] == '-')
|
|
parse_mount_options(argv[i]+2, &flags, &string_flags);
|
|
else argv[opt++] = argv[i];
|
|
}
|
|
argc = opt;
|
|
|
|
// Parse remaining options
|
|
|
|
while((opt = getopt(argc, argv, "o:t:rwafnv")) > 0) {
|
|
switch (opt) {
|
|
case 'o':
|
|
parse_mount_options(optarg, &flags, &string_flags);
|
|
break;
|
|
case 't':
|
|
fsType = optarg;
|
|
break;
|
|
case 'r':
|
|
flags |= MS_RDONLY;
|
|
break;
|
|
case 'w':
|
|
allowWrite=TRUE;
|
|
break;
|
|
case 'a':
|
|
all = TRUE;
|
|
break;
|
|
case 'f':
|
|
fakeIt = TRUE;
|
|
break;
|
|
case 'n':
|
|
useMtab = FALSE;
|
|
break;
|
|
case 'v':
|
|
break; // ignore -v
|
|
default:
|
|
bb_show_usage();
|
|
}
|
|
}
|
|
|
|
// If we have no arguments, show currently mounted filesystems
|
|
|
|
if(!all && (optind == argc)) {
|
|
FILE *mountTable = setmntent(bb_path_mtab_file, "r");
|
|
|
|
if(!mountTable) bb_perror_msg_and_die(bb_path_mtab_file);
|
|
|
|
while (getmntent_r(mountTable,&m,path,sizeof(path))) {
|
|
blockDevice = m.mnt_fsname;
|
|
|
|
// Clean up display a little bit regarding root device
|
|
if(!strcmp(blockDevice, "rootfs")) continue;
|
|
if(!strcmp(blockDevice, "/dev/root"))
|
|
blockDevice = find_block_device("/");
|
|
|
|
if(!fsType || !strcmp(m.mnt_type, fsType))
|
|
printf("%s on %s type %s (%s)\n", blockDevice, m.mnt_dir,
|
|
m.mnt_type, m.mnt_opts);
|
|
if(ENABLE_FEATURE_CLEAN_UP && blockDevice != m.mnt_fsname)
|
|
free(blockDevice);
|
|
}
|
|
endmntent(mountTable);
|
|
return EXIT_SUCCESS;
|
|
}
|
|
|
|
/* The next argument is what to mount. if there's an argument after that
|
|
* it's where to mount it. If we're not mounting all, and we have both
|
|
* of these arguments, jump straight to the actual mount. */
|
|
|
|
statbuf.st_mode=0;
|
|
if(optind < argc)
|
|
blockDevice = !stat(argv[optind], &statbuf) ?
|
|
bb_simplify_path(argv[optind]) :
|
|
(ENABLE_FEATURE_CLEAN_UP ? strdup(argv[optind]) : argv[optind]);
|
|
if(optind+1 < argc) directory = bb_simplify_path(argv[optind+1]);
|
|
|
|
// If we don't have to loop through fstab, skip ahead a bit.
|
|
|
|
if(!all && optind+1!=argc) goto singlemount;
|
|
|
|
// Loop through /etc/fstab entries to look up this entry.
|
|
|
|
if(!(file=setmntent("/etc/fstab","r")))
|
|
bb_perror_msg_and_die("\nCannot read /etc/fstab");
|
|
for(;;) {
|
|
|
|
// Get next fstab entry
|
|
|
|
if(!getmntent_r(file,&m,path,sizeof(path))) {
|
|
if(!all)
|
|
bb_perror_msg("Can't find %s in /etc/fstab\n", blockDevice);
|
|
break;
|
|
}
|
|
|
|
// If we're mounting all and all doesn't mount this one, skip it.
|
|
|
|
if(all) {
|
|
if(strstr(m.mnt_opts,"noauto") || strstr(m.mnt_type,"swap"))
|
|
continue;
|
|
flags=0;
|
|
|
|
/* If we're mounting something specific and this isn't it, skip it.
|
|
* Note we must match both the exact text in fstab (ala "proc") or
|
|
* a full path from root */
|
|
|
|
} else if(strcmp(blockDevice,m.mnt_fsname) &&
|
|
strcmp(argv[optind],m.mnt_fsname) &&
|
|
strcmp(blockDevice,m.mnt_dir) &&
|
|
strcmp(argv[optind],m.mnt_dir)) continue;
|
|
|
|
/* Parse flags from /etc/fstab (unless this is a single mount
|
|
* overriding fstab -- note the "all" test above zeroed the flags,
|
|
* to prevent flags from previous entries affecting this one, so
|
|
* the only way we could get here with nonzero flags is a single
|
|
* mount). */
|
|
|
|
if(!flags) {
|
|
if(ENABLE_FEATURE_CLEAN_UP) free(string_flags);
|
|
string_flags=NULL;
|
|
parse_mount_options(m.mnt_opts, &flags, &string_flags);
|
|
}
|
|
|
|
/* Fill out remaining fields with info from mtab */
|
|
|
|
if(ENABLE_FEATURE_CLEAN_UP) {
|
|
free(blockDevice);
|
|
blockDevice=strdup(m.mnt_fsname);
|
|
free(directory);
|
|
directory=strdup(m.mnt_dir);
|
|
} else {
|
|
blockDevice=m.mnt_fsname;
|
|
directory=m.mnt_dir;
|
|
}
|
|
fsType=m.mnt_type;
|
|
|
|
/* Ok, we're ready to actually mount a specific source on a specific
|
|
* directory now. */
|
|
|
|
singlemount:
|
|
|
|
// If they said -w, override fstab
|
|
|
|
if(allowWrite) flags&=~MS_RDONLY;
|
|
|
|
// Might this be an NFS filesystem?
|
|
|
|
if(ENABLE_FEATURE_MOUNT_NFS && (!fsType || !strcmp(fsType,"nfs")) &&
|
|
strchr(blockDevice, ':') != NULL)
|
|
{
|
|
if(nfsmount(blockDevice, directory, &flags, &string_flags, 1))
|
|
bb_perror_msg("nfsmount failed");
|
|
else {
|
|
rc = 0;
|
|
fsType="nfs";
|
|
// Strangely enough, nfsmount() doesn't actually mount()
|
|
goto mount_it_now;
|
|
}
|
|
} else {
|
|
|
|
// Do we need to allocate a loopback device?
|
|
|
|
if(ENABLE_FEATURE_MOUNT_LOOP && !fakeIt && S_ISREG(statbuf.st_mode))
|
|
{
|
|
loopFile = blockDevice;
|
|
blockDevice = 0;
|
|
switch(set_loop(&blockDevice, loopFile, 0)) {
|
|
case 0:
|
|
case 1:
|
|
break;
|
|
default:
|
|
bb_error_msg_and_die(
|
|
errno == EPERM || errno == EACCES ?
|
|
bb_msg_perm_denied_are_you_root :
|
|
"Couldn't setup loop device");
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* If we know the fstype (or don't need to), jump straight
|
|
* to the actual mount. */
|
|
|
|
if(fsType || (flags & (MS_REMOUNT | MS_BIND | MS_MOVE)))
|
|
goto mount_it_now;
|
|
}
|
|
|
|
// Loop through filesystem types until mount succeeds or we run out
|
|
|
|
for(i = 0; files[i] && rc; i++) {
|
|
f = fopen(files[i], "r");
|
|
if(!f) continue;
|
|
// Get next block device backed filesystem
|
|
for(buf = 0; (buf = fsType = bb_get_chomped_line_from_file(f));
|
|
free(buf))
|
|
{
|
|
// Skip funky entries in /proc
|
|
if(!strncmp(buf,"nodev",5) && isspace(buf[5])) continue;
|
|
|
|
while(isspace(*fsType)) fsType++;
|
|
if(*buf=='#' || *buf=='*') continue;
|
|
if(!*fsType) continue;
|
|
mount_it_now:
|
|
// Okay, try to mount
|
|
|
|
if (!fakeIt) {
|
|
for(;;) {
|
|
rc = mount(blockDevice, directory, fsType, flags, string_flags);
|
|
if(!rc || (flags&MS_RDONLY) || (errno!=EACCES && errno!=EROFS))
|
|
break;
|
|
bb_error_msg("%s is write-protected, mounting read-only", blockDevice);
|
|
flags|=MS_RDONLY;
|
|
}
|
|
}
|
|
if(!rc || !f) break;
|
|
}
|
|
if(!f) break;
|
|
fclose(f);
|
|
// goto mount_it_now with -a can jump past the initialization
|
|
f=0;
|
|
if(!rc) break;
|
|
}
|
|
|
|
/* If the mount was successful, and we're maintaining an old-style
|
|
* mtab file by hand, add new entry to it now. */
|
|
if((!rc || fakeIt) && useMtab) {
|
|
FILE *mountTable = setmntent(bb_path_mtab_file, "a+");
|
|
|
|
if(!mountTable) bb_perror_msg(bb_path_mtab_file);
|
|
else {
|
|
// Remove trailing / (if any) from directory we mounted on
|
|
int length=strlen(directory);
|
|
if(length>1 && directory[length-1] == '/')
|
|
directory[length-1]=0;
|
|
|
|
// Fill out structure (should be ok to re-use existing one).
|
|
m.mnt_fsname=blockDevice;
|
|
m.mnt_dir=directory;
|
|
m.mnt_type=fsType ? : "--bind";
|
|
m.mnt_opts=string_flags ? :
|
|
((flags & MS_RDONLY) ? "ro" : "rw");
|
|
m.mnt_freq = 0;
|
|
m.mnt_passno = 0;
|
|
|
|
// Write and close
|
|
addmntent(mountTable, &m);
|
|
endmntent(mountTable);
|
|
}
|
|
} else {
|
|
// Mount failed. Clean up
|
|
if(loopFile) {
|
|
del_loop(blockDevice);
|
|
if(ENABLE_FEATURE_CLEAN_UP) free(loopFile);
|
|
}
|
|
// Don't whine about already mounted fs when mounting all.
|
|
if(rc<0 && errno == EBUSY && all) rc = 0;
|
|
else if (errno == EPERM)
|
|
bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
|
|
}
|
|
// We couldn't free this earlier becase fsType could be in buf.
|
|
if(ENABLE_FEATURE_CLEAN_UP) free(buf);
|
|
if(!all) break;
|
|
}
|
|
|
|
if(file) endmntent(file);
|
|
if(rc) bb_perror_msg("Mounting %s on %s failed", blockDevice, directory);
|
|
if(ENABLE_FEATURE_CLEAN_UP) {
|
|
free(blockDevice);
|
|
free(directory);
|
|
}
|
|
|
|
return rc;
|
|
}
|