cos2000v2/lib/cramfs.c

326 lines
8.9 KiB
C

/*******************************************************************************/
/* COS2000 - Compatible Operating System - LGPL v3 - Hordé Nicolas */
/* */
/* Quelques portions modifiée proviennent de cramfsck - check a cramfs file system
*
* Copyright (C) 2000-2002 Transmeta Corporation
*
* 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
*
* 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)
* 2015/06/09: Yves-Noel Weweler (support for ignoring errors, when
* extracting obscure cramfs files) */
#include "types.h"
#include "cramfs.h"
#include "boot.h"
#include "memory.h"
u8* initrambloc;
u8 start;
cramfs_super* super;
extern bootparams* allparams;
/*******************************************************************************/
/* Copie l'initram CRAMFS vers un malloc */
void remap_initram()
{
virtual_range_use_kernel(allparams->ramdiskaddr, allparams->ramdiskaddr, allparams->ramdisksize, PAGE_NOFLAG);
initrambloc=vmalloc(allparams->ramdisksize);
memcpy(allparams->ramdiskaddr,initrambloc,allparams->ramdisksize,0);
virtual_range_free_kernel(allparams->ramdiskaddr,allparams->ramdisksize);
}
/*******************************************************************************/
/* Lit l'inode et renvoie un pointeur grâce à vmalloc */
cramfs_inode *cramfs_iget(cramfs_inode * i)
{
cramfs_inode *inode = vmalloc(sizeof(cramfs_inode));
if (!inode)
return NULL;
*inode = *i;
return inode;
}
/*******************************************************************************/
/* Lit l'inode principal */
cramfs_inode *read_super(void)
{
u32 offset = super.root.offset << 2;
if (!S_ISDIR(super.root.mode))
return NULL; /* fichier */
if (!(super.flags & CRAMFS_FLAG_SHIFTED_ROOT_OFFSET) && ((offset != sizeof(cramfs_super)) &&
(offset != PAD_SIZE + sizeof(cramfs_super))))
return NULL ; /*offset erronée */
return cramfs_iget(&super.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_CACHE_SIZE*2;
inflateReset(&stream);
if (len > PAGE_CACHE_SIZE*2) {
die(FSCK_UNCORRECTED, 0, "data block too large");
}
err = inflate(&stream, Z_FINISH);
if (err != Z_STREAM_END) {
die(FSCK_UNCORRECTED, 0, "decompression error %p(%d): %s",
zError(err), src, len);
}
return stream.total_out;
}
static void do_uncompress(char *path, int fd, unsigned long offset, unsigned long size)
{
unsigned long curr = offset + 4 * ((size + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE);
do {
unsigned long out = PAGE_CACHE_SIZE;
unsigned long next = *(u32 *) romfs_read(offset);
if (next > end_data) {
end_data = next;
}
offset += 4;
if (curr == next) {
if (opt_verbose > 1) {
printf(" hole at %ld (%d)\n", curr, PAGE_CACHE_SIZE);
}
if (size < PAGE_CACHE_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_CACHE_SIZE) {
if (out != PAGE_CACHE_SIZE) {
die(FSCK_UNCORRECTED, 0, "non-block (%ld) bytes", out);
}
} else {
if (out != size) {
die(FSCK_UNCORRECTED, 0, "non-size (%ld vs %ld) bytes", out, size);
}
}
size -= out;
if (opt_extract) {
if (write(fd, outbuffer, out) < 0) {
die(FSCK_ERROR, 1, "write failed: %s", path);
}
}
curr = next;
} while (size);
}
tatic 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) {
die(FSCK_ERROR, 1, "lchown failed: %s", path);
}
if (S_ISLNK(i->mode))
return;
if ((S_ISUID | S_ISGID) & i->mode) {
if (chmod(path, i->mode) < 0) {
die(FSCK_ERROR, 1, "chown failed: %s", path);
}
}
}
if (S_ISLNK(i->mode))
return;
if (utime(path, &epoch) < 0) {
die(FSCK_ERROR, 1, "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 = malloc(pathlen + 256);
if (!newpath) {
die(FSCK_ERROR, 1, "malloc failed");
}
if (offset == 0 && count != 0) {
die(FSCK_UNCORRECTED, 0, "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) {
die(FSCK_ERROR, 1, "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) {
die(FSCK_UNCORRECTED, 0, "filename length is zero");
}
if ((pathlen + newlen) - strlen(newpath) > 3) {
die(FSCK_UNCORRECTED, 0, "bad filename length");
}
expand_fs(newpath, child);
offset += newlen;
if (offset <= start_dir) {
die(FSCK_UNCORRECTED, 0, "bad inode offset");
}
if (offset > end_dir) {
end_dir = offset;
}
iput(child); /* free(child) */
}
free(newpath);
}
void do_file(u8 *path, cramfs_inode *i)
{
u32 offset = i->offset << 2;
if (offset == 0 && i->size != 0)
return /*null de taille non nulle */
if (i->size == 0 && offset != 0)
return /*non null de taille nulle */
if (offset != 0 && offset < start_data)
start_data = offset;
fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, i->mode);
if (i->size)
do_uncompress(path, fd, offset, i->size);
close(fd);
change_file_status(path, i);
}
void expand_fs(u8 *path, 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);*/
}
}
/*******************************************************************************/
/* Vérification d'une image cramfs */
/* ERREURS :
/* 1=taille du super bloc trop petite */
/* 2=pas de magic */
/* 3=pas géré */
/* 4=superbloc trop petit */
/* 5=aucune fichier */
/* 6=taille entrée des fichiers trop petite */
/* 7=taille entrée des fichiers trop grande */
/* 8=version de cramfs non supportée */
/* 9=crc erroné */
u32 test_super(u8 *src, u32 length) {
super=(cramfs_super*)src;
start = 0xFF;
if (length < sizeof(cramfs_super)) {
return 1;
}
if (super->magic == CRAMFS_MAGIC) {
start = 0;
}
else if (length >= (PAD_SIZE + sizeof(super))) {
if (super->magic == CRAMFS_MAGIC) {
start = PAD_SIZE;
}
}
else
return 2;
if (super->flags & ~CRAMFS_SUPPORTED_FLAGS)
return 3;
if (super->size < PAGE_CACHE_SIZE)
return 4;
if (super->flags & CRAMFS_FLAG_FSID_VERSION_2) {
if (super->fsid.files == 0)
return 5;
if (length < super->size)
return 6;
else if (length > super->size)
return 7;
}
else
return 8;
u32 oldcrc=super->fsid.crc;
super->fsid.crc = crc32(0, 0, 0);
u32 newcrc=crc32(0,src+*start,super->size-*start);
super->fsid.crc = oldcrc;
if (newcrc!=oldcrc)
return 9;
return NULL;
}