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util-linux/disk-utils/fsck.cramfs.c

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/*
* cramfsck - check a cramfs file system
*
* Copyright (C) 2000-2002 Transmeta Corporation
* 2005 Adrian Bunk
*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* 1999/12/03: Linus Torvalds (cramfs tester and unarchive program)
* 2000/06/03: Daniel Quinlan (CRC and length checking program)
* 2000/06/04: Daniel Quinlan (merged programs, added options, support
* for special files, preserve permissions and
* ownership, cramfs superblock v2, bogus mode
* test, pathname length test, etc.)
* 2000/06/06: Daniel Quinlan (support for holes, pretty-printing,
* symlink size test)
* 2000/07/11: Daniel Quinlan (file length tests, start at offset 0 or 512,
* fsck-compatible exit codes)
* 2000/07/15: Daniel Quinlan (initial support for block devices)
* 2002/01/10: Daniel Quinlan (additional checks, test more return codes,
* use read if mmap fails, standardize messages)
*/
/* compile-time options */
//#define INCLUDE_FS_TESTS /* include cramfs checking and extraction */
#include <stdio.h>
#include <stdarg.h>
#include <stdint.h>
#include <unistd.h>
#include <dirent.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <getopt.h>
#include <utime.h>
#include <fcntl.h>
#include <zlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/sysmacros.h> /* for major, minor */
#include "cramfs.h"
#include "nls.h"
#include "blkdev.h"
#include "c.h"
#include "exitcodes.h"
#define XALLOC_EXIT_CODE FSCK_ERROR
#include "xalloc.h"
static const char *progname = "cramfsck";
static int fd; /* ROM image file descriptor */
static char *filename; /* ROM image filename */
struct cramfs_super super; /* just find the cramfs superblock once */
static int cramfs_is_big_endian = 0; /* source is big endian */
static int opt_verbose = 0; /* 1 = verbose (-v), 2+ = very verbose (-vv) */
char *extract_dir = ""; /* extraction directory (-x) */
#define PAD_SIZE 512
#ifdef INCLUDE_FS_TESTS
static int opt_extract = 0; /* extract cramfs (-x) */
static uid_t euid; /* effective UID */
/* (cramfs_super + start) <= start_dir < end_dir <= start_data <= end_data */
static unsigned long start_dir = ~0UL; /* start of first non-root inode */
static unsigned long end_dir = 0; /* end of the directory structure */
static unsigned long start_data = ~0UL; /* start of the data (256 MB = max) */
static unsigned long end_data = 0; /* end of the data */
/* Guarantee access to at least 8kB at a time */
#define ROMBUFFER_BITS 13
#define ROMBUFFERSIZE (1 << ROMBUFFER_BITS)
#define ROMBUFFERMASK (ROMBUFFERSIZE - 1)
static char read_buffer[ROMBUFFERSIZE * 2];
static unsigned long read_buffer_block = ~0UL;
static z_stream stream;
/* Prototypes */
static void expand_fs(char *, struct cramfs_inode *);
#endif /* INCLUDE_FS_TESTS */
static char *outbuffer;
static size_t page_size;
/* Input status of 0 to print help and exit without an error. */
static void __attribute__((__noreturn__)) usage(int status)
{
FILE *stream = status ? stderr : stdout;
fprintf(stream, _("usage: %s [-hv] [-x dir] file\n"
" -h print this help\n"
" -x dir extract into dir\n"
" -v be more verbose\n"
" file file to test\n"), progname);
exit(status);
}
int get_superblock_endianness(uint32_t magic)
{
if (magic == CRAMFS_MAGIC) {
cramfs_is_big_endian = HOST_IS_BIG_ENDIAN;
return 0;
} else if (magic ==
u32_toggle_endianness(!HOST_IS_BIG_ENDIAN, CRAMFS_MAGIC)) {
cramfs_is_big_endian = !HOST_IS_BIG_ENDIAN;
return 0;
} else
return -1;
}
static void test_super(int *start, size_t * length)
{
struct stat st;
/* find the physical size of the file or block device */
if (stat(filename, &st) < 0)
err(FSCK_ERROR, _("stat failed: %s"), filename);
fd = open(filename, O_RDONLY);
if (fd < 0)
err(FSCK_ERROR, _("open failed: %s"), filename);
if (S_ISBLK(st.st_mode)) {
unsigned long long bytes;
if (blkdev_get_size(fd, &bytes))
err(FSCK_ERROR,
_("ioctl failed: unable to determine device size: %s"),
filename);
*length = bytes;
} else if (S_ISREG(st.st_mode))
*length = st.st_size;
else
errx(FSCK_ERROR, _("not a block device or file: %s"), filename);
if (*length < sizeof(struct cramfs_super))
errx(FSCK_UNCORRECTED, _("file length too short"));
/* find superblock */
if (read(fd, &super, sizeof(super)) != sizeof(super))
err(FSCK_ERROR, _("read failed: %s"), filename);
if (get_superblock_endianness(super.magic) != -1)
*start = 0;
else if (*length >= (PAD_SIZE + sizeof(super))) {
lseek(fd, PAD_SIZE, SEEK_SET);
if (read(fd, &super, sizeof(super)) != sizeof(super))
err(FSCK_ERROR, _("read failed: %s"), filename);
if (get_superblock_endianness(super.magic) != -1)
*start = PAD_SIZE;
else
errx(FSCK_UNCORRECTED, _("superblock magic not found"));
} else
errx(FSCK_UNCORRECTED, _("superblock magic not found"));
if (opt_verbose)
printf(_("cramfs endianness is %s\n"),
cramfs_is_big_endian ? _("big") : _("little"));
super_toggle_endianness(cramfs_is_big_endian, &super);
if (super.flags & ~CRAMFS_SUPPORTED_FLAGS)
errx(FSCK_ERROR, _("unsupported filesystem features"));
if (super.size < page_size)
errx(FSCK_UNCORRECTED, _("superblock size (%d) too small"),
super.size);
if (super.flags & CRAMFS_FLAG_FSID_VERSION_2) {
if (super.fsid.files == 0)
errx(FSCK_UNCORRECTED, _("zero file count"));
if (*length < super.size)
errx(FSCK_UNCORRECTED, _("file length too short"));
else if (*length > super.size)
fprintf(stderr,
_("warning: file extends past end of filesystem\n"));
} else
fprintf(stderr, _("warning: old cramfs format\n"));
}
static void test_crc(int start)
{
void *buf;
uint32_t crc;
if (!(super.flags & CRAMFS_FLAG_FSID_VERSION_2)) {
#ifdef INCLUDE_FS_TESTS
return;
#else
errx(FSCK_USAGE, _("unable to test CRC: old cramfs format"));
#endif
}
crc = crc32(0L, Z_NULL, 0);
buf =
mmap(NULL, super.size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
if (buf == MAP_FAILED) {
buf =
mmap(NULL, super.size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (buf != MAP_FAILED) {
lseek(fd, 0, SEEK_SET);
if (read(fd, buf, super.size) < 0)
err(FSCK_ERROR, _("read failed: %s"), filename);
}
}
if (buf != MAP_FAILED) {
((struct cramfs_super *)(buf + start))->fsid.crc =
crc32(0L, Z_NULL, 0);
crc = crc32(crc, buf + start, super.size - start);
munmap(buf, super.size);
} else {
int retval;
size_t length = 0;
buf = xmalloc(4096);
lseek(fd, start, SEEK_SET);
for (;;) {
retval = read(fd, buf, 4096);
if (retval < 0)
err(FSCK_ERROR, _("read failed: %s"), filename);
else if (retval == 0)
break;
if (length == 0)
((struct cramfs_super *)buf)->fsid.crc =
crc32(0L, Z_NULL, 0);
length += retval;
if (length > (super.size - start)) {
crc = crc32(crc, buf,
retval - (length -
(super.size - start)));
break;
}
crc = crc32(crc, buf, retval);
}
free(buf);
}
if (crc != super.fsid.crc)
errx(FSCK_UNCORRECTED, _("crc error"));
}
#ifdef INCLUDE_FS_TESTS
static void print_node(char type, struct cramfs_inode *i, char *name)
{
char info[10];
if (S_ISCHR(i->mode) || (S_ISBLK(i->mode)))
/* major/minor numbers can be as high as 2^12 or 4096 */
snprintf(info, 10, "%4d,%4d", major(i->size), minor(i->size));
else
/* size be as high as 2^24 or 16777216 */
snprintf(info, 10, "%9d", i->size);
printf("%c %04o %s %5d:%-3d %s\n",
type, i->mode & ~S_IFMT, info, i->uid, i->gid,
!*name && type == 'd' ? "/" : name);
}
/*
* Create a fake "blocked" access
*/
static void *romfs_read(unsigned long offset)
{
unsigned int block = offset >> ROMBUFFER_BITS;
if (block != read_buffer_block) {
read_buffer_block = block;
lseek(fd, block << ROMBUFFER_BITS, SEEK_SET);
read(fd, read_buffer, ROMBUFFERSIZE * 2);
}
return read_buffer + (offset & ROMBUFFERMASK);
}
static struct cramfs_inode *cramfs_iget(struct cramfs_inode *i)
{
struct cramfs_inode *inode = xmalloc(sizeof(struct cramfs_inode));
inode_to_host(cramfs_is_big_endian, i, inode);
return inode;
}
static struct cramfs_inode *iget(unsigned int ino)
{
return cramfs_iget(romfs_read(ino));
}
static void iput(struct cramfs_inode *inode)
{
free(inode);
}
/*
* Return the offset of the root directory
*/
static struct cramfs_inode *read_super(void)
{
struct cramfs_inode *root = cramfs_iget(&super.root);
unsigned long offset = root->offset << 2;
if (!S_ISDIR(root->mode))
errx(FSCK_UNCORRECTED, _("root inode is not directory"));
if (!(super.flags & CRAMFS_FLAG_SHIFTED_ROOT_OFFSET) &&
((offset != sizeof(struct cramfs_super)) &&
(offset != PAD_SIZE + sizeof(struct cramfs_super)))) {
errx(FSCK_UNCORRECTED, _("bad root offset (%lu)"), offset);
}
return root;
}
static int uncompress_block(void *src, int len)
{
int err;
stream.next_in = src;
stream.avail_in = len;
stream.next_out = (unsigned char *)outbuffer;
stream.avail_out = page_size * 2;
inflateReset(&stream);
if (len > page_size * 2)
errx(FSCK_UNCORRECTED, _("data block too large"));
err = inflate(&stream, Z_FINISH);
if (err != Z_STREAM_END)
errx(FSCK_UNCORRECTED, _("decompression error %p(%d): %s"),
zError(err), src, len);
return stream.total_out;
}
#if !HAVE_LCHOWN
#define lchown chown
#endif
static void do_uncompress(char *path, int fd, unsigned long offset,
unsigned long size)
{
unsigned long curr = offset + 4 * ((size + page_size - 1) / page_size);
do {
unsigned long out = page_size;
unsigned long next = u32_toggle_endianness(cramfs_is_big_endian,
*(uint32_t *)
romfs_read(offset));
if (next > end_data)
end_data = next;
offset += 4;
if (curr == next) {
if (opt_verbose > 1)
printf(_(" hole at %ld (%zd)\n"), curr,
page_size);
if (size < page_size)
out = size;
memset(outbuffer, 0x00, out);
} else {
if (opt_verbose > 1)
printf(_(" uncompressing block at %ld to %ld (%ld)\n"),
curr, next, next - curr);
out = uncompress_block(romfs_read(curr), next - curr);
}
if (size >= page_size) {
if (out != page_size)
errx(FSCK_UNCORRECTED,
_("non-block (%ld) bytes"), out);
} else {
if (out != size)
errx(FSCK_UNCORRECTED,
_("non-size (%ld vs %ld) bytes"), out,
size);
}
size -= out;
if (opt_extract)
if (write(fd, outbuffer, out) < 0)
err(FSCK_ERROR, _("write failed: %s"),
path);
curr = next;
} while (size);
}
static void change_file_status(char *path, struct cramfs_inode *i)
{
struct utimbuf epoch = { 0, 0 };
if (euid == 0) {
if (lchown(path, i->uid, i->gid) < 0)
err(FSCK_ERROR, _("lchown failed: %s"), path);
if (S_ISLNK(i->mode))
return;
if (((S_ISUID | S_ISGID) & i->mode) && chmod(path, i->mode) < 0)
err(FSCK_ERROR, _("chown failed: %s"), path);
}
if (S_ISLNK(i->mode))
return;
if (utime(path, &epoch) < 0)
err(FSCK_ERROR, _("utime failed: %s"), path);
}
static void do_directory(char *path, struct cramfs_inode *i)
{
int pathlen = strlen(path);
int count = i->size;
unsigned long offset = i->offset << 2;
char *newpath = xmalloc(pathlen + 256);
if (offset == 0 && count != 0)
errx(FSCK_UNCORRECTED,
_("directory inode has zero offset and non-zero size: %s"),
path);
if (offset != 0 && offset < start_dir)
start_dir = offset;
/* TODO: Do we need to check end_dir for empty case? */
memcpy(newpath, path, pathlen);
newpath[pathlen] = '/';
pathlen++;
if (opt_verbose)
print_node('d', i, path);
if (opt_extract) {
if (mkdir(path, i->mode) < 0)
err(FSCK_ERROR, _("mkdir failed: %s"), path);
change_file_status(path, i);
}
while (count > 0) {
struct cramfs_inode *child = iget(offset);
int size;
int newlen = child->namelen << 2;
size = sizeof(struct cramfs_inode) + newlen;
count -= size;
offset += sizeof(struct cramfs_inode);
memcpy(newpath + pathlen, romfs_read(offset), newlen);
newpath[pathlen + newlen] = 0;
if (newlen == 0)
errx(FSCK_UNCORRECTED, _("filename length is zero"));
if ((pathlen + newlen) - strlen(newpath) > 3)
errx(FSCK_UNCORRECTED, _("bad filename length"));
expand_fs(newpath, child);
offset += newlen;
if (offset <= start_dir)
errx(FSCK_UNCORRECTED, _("bad inode offset"));
if (offset > end_dir)
end_dir = offset;
iput(child); /* free(child) */
}
free(newpath);
}
static void do_file(char *path, struct cramfs_inode *i)
{
unsigned long offset = i->offset << 2;
int fd = 0;
if (offset == 0 && i->size != 0)
errx(FSCK_UNCORRECTED,
_("file inode has zero offset and non-zero size"));
if (i->size == 0 && offset != 0)
errx(FSCK_UNCORRECTED,
_("file inode has zero size and non-zero offset"));
if (offset != 0 && offset < start_data)
start_data = offset;
if (opt_verbose)
print_node('f', i, path);
if (opt_extract) {
fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, i->mode);
if (fd < 0)
err(FSCK_ERROR, _("open failed: %s"), path);
}
if (i->size)
do_uncompress(path, fd, offset, i->size);
if (opt_extract) {
close(fd);
change_file_status(path, i);
}
}
static void do_symlink(char *path, struct cramfs_inode *i)
{
unsigned long offset = i->offset << 2;
unsigned long curr = offset + 4;
unsigned long next =
u32_toggle_endianness(cramfs_is_big_endian,
*(uint32_t *) romfs_read(offset));
unsigned long size;
if (offset == 0)
errx(FSCK_UNCORRECTED, _("symbolic link has zero offset"));
if (i->size == 0)
errx(FSCK_UNCORRECTED, _("symbolic link has zero size"));
if (offset < start_data)
start_data = offset;
if (next > end_data)
end_data = next;
size = uncompress_block(romfs_read(curr), next - curr);
if (size != i->size)
errx(FSCK_UNCORRECTED, _("size error in symlink: %s"), path);
outbuffer[size] = 0;
if (opt_verbose) {
char *str;
asprintf(&str, "%s -> %s", path, outbuffer);
print_node('l', i, str);
if (opt_verbose > 1)
printf(_(" uncompressing block at %ld to %ld (%ld)\n"),
curr, next, next - curr);
free(str);
}
if (opt_extract) {
if (symlink(outbuffer, path) < 0)
err(FSCK_ERROR, _("symlink failed: %s"), path);
change_file_status(path, i);
}
}
static void do_special_inode(char *path, struct cramfs_inode *i)
{
dev_t devtype = 0;
char type;
if (i->offset)
/* no need to shift offset */
errx(FSCK_UNCORRECTED,
_("special file has non-zero offset: %s"), path);
if (S_ISCHR(i->mode)) {
devtype = i->size;
type = 'c';
} else if (S_ISBLK(i->mode)) {
devtype = i->size;
type = 'b';
} else if (S_ISFIFO(i->mode)) {
if (i->size != 0)
errx(FSCK_UNCORRECTED, _("fifo has non-zero size: %s"),
path);
type = 'p';
} else if (S_ISSOCK(i->mode)) {
if (i->size != 0)
errx(FSCK_UNCORRECTED,
_("socket has non-zero size: %s"), path);
type = 's';
} else {
errx(FSCK_UNCORRECTED, _("bogus mode: %s (%o)"), path, i->mode);
return; /* not reached */
}
if (opt_verbose)
print_node(type, i, path);
if (opt_extract) {
if (mknod(path, i->mode, devtype) < 0)
err(FSCK_ERROR, _("mknod failed: %s"), path);
change_file_status(path, i);
}
}
static void expand_fs(char *path, struct cramfs_inode *inode)
{
if (S_ISDIR(inode->mode))
do_directory(path, inode);
else if (S_ISREG(inode->mode))
do_file(path, inode);
else if (S_ISLNK(inode->mode))
do_symlink(path, inode);
else
do_special_inode(path, inode);
}
static void test_fs(int start)
{
struct cramfs_inode *root;
root = read_super();
umask(0);
euid = geteuid();
stream.next_in = NULL;
stream.avail_in = 0;
inflateInit(&stream);
expand_fs(extract_dir, root);
inflateEnd(&stream);
if (start_data != ~0UL) {
if (start_data < (sizeof(struct cramfs_super) + start))
errx(FSCK_UNCORRECTED,
_("directory data start (%ld) < sizeof(struct cramfs_super) + start (%ld)"),
start_data, sizeof(struct cramfs_super) + start);
if (end_dir != start_data)
errx(FSCK_UNCORRECTED,
_("directory data end (%ld) != file data start (%ld)"),
end_dir, start_data);
}
if (super.flags & CRAMFS_FLAG_FSID_VERSION_2)
if (end_data > super.size)
errx(FSCK_UNCORRECTED, _("invalid file data offset"));
iput(root); /* free(root) */
}
#endif /* INCLUDE_FS_TESTS */
int main(int argc, char **argv)
{
int c; /* for getopt */
int start = 0;
size_t length = 0;
setlocale(LC_MESSAGES, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
page_size = getpagesize();
if (argc)
progname = argv[0];
outbuffer = xmalloc(page_size * 2);
/* command line options */
while ((c = getopt(argc, argv, "hx:v")) != EOF)
switch (c) {
case 'h':
usage(FSCK_OK);
break;
case 'x':
#ifdef INCLUDE_FS_TESTS
opt_extract = 1;
extract_dir = optarg;
break;
#else
errx(FSCK_USAGE, _("compiled without -x support"));
#endif
case 'v':
opt_verbose++;
break;
}
if ((argc - optind) != 1)
usage(FSCK_USAGE);
filename = argv[optind];
test_super(&start, &length);
test_crc(start);
#ifdef INCLUDE_FS_TESTS
test_fs(start);
#endif
if (opt_verbose)
printf(_("%s: OK\n"), filename);
exit(FSCK_OK);
}
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