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initial commit
This commit is contained in:
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487 changed files with 114253 additions and 0 deletions
632
SQUASHFS/squashfs-tools-4.4/squashfs-tools/unsquash-3.c
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632
SQUASHFS/squashfs-tools-4.4/squashfs-tools/unsquash-3.c
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@ -0,0 +1,632 @@
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/*
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* Unsquash a squashfs filesystem. This is a highly compressed read only
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* filesystem.
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*
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* Copyright (c) 2009, 2010, 2011, 2012, 2013, 2019
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* Phillip Lougher <phillip@squashfs.org.uk>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2,
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* or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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* unsquash-3.c
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*/
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#include "unsquashfs.h"
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#include "squashfs_compat.h"
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static squashfs_fragment_entry_3 *fragment_table;
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static unsigned int *uid_table, *guid_table;
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static char *inode_table, *directory_table;
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static squashfs_operations ops;
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static long long *salloc_index_table(int indexes)
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{
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static long long *alloc_table = NULL;
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static int alloc_size = 0;
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int length = indexes * sizeof(long long);
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if(alloc_size < length || length == 0) {
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long long *table = realloc(alloc_table, length);
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if(table == NULL && length !=0 )
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EXIT_UNSQUASH("alloc_index_table: failed to allocate "
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"index table\n");
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alloc_table = table;
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alloc_size = length;
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}
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return alloc_table;
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}
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static void read_block_list(unsigned int *block_list, char *block_ptr, int blocks)
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{
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TRACE("read_block_list: blocks %d\n", blocks);
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if(swap) {
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SQUASHFS_SWAP_INTS_3(block_list, block_ptr, blocks);
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} else
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memcpy(block_list, block_ptr, blocks * sizeof(unsigned int));
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}
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static int read_fragment_table(long long *table_start)
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{
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/*
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* Note on overflow limits:
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* Size of SBlk.s.fragments is 2^32 (unsigned int)
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* Max size of bytes is 2^32*16 or 2^36
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* Max indexes is (2^32*16)/8K or 2^23
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* Max length is ((2^32*16)/8K)*8 or 2^26 or 64M
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*/
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int res, i;
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long long bytes = SQUASHFS_FRAGMENT_BYTES_3((long long) sBlk.s.fragments);
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int indexes = SQUASHFS_FRAGMENT_INDEXES_3((long long) sBlk.s.fragments);
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int length = SQUASHFS_FRAGMENT_INDEX_BYTES_3((long long) sBlk.s.fragments);
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long long *fragment_table_index;
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/*
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* The size of the index table (length bytes) should match the
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* table start and end points
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*/
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if(length != (*table_start - sBlk.s.fragment_table_start)) {
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ERROR("read_fragment_table: Bad fragment count in super block\n");
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return FALSE;
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}
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TRACE("read_fragment_table: %d fragments, reading %d fragment indexes "
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"from 0x%llx\n", sBlk.s.fragments, indexes,
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sBlk.s.fragment_table_start);
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fragment_table_index = alloc_index_table(indexes);
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fragment_table = malloc(bytes);
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if(fragment_table == NULL)
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EXIT_UNSQUASH("read_fragment_table: failed to allocate "
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"fragment table\n");
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if(swap) {
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long long *sfragment_table_index = salloc_index_table(indexes);
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res = read_fs_bytes(fd, sBlk.s.fragment_table_start,
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length, sfragment_table_index);
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if(res == FALSE) {
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ERROR("read_fragment_table: failed to read fragment "
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"table index\n");
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return FALSE;
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}
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SQUASHFS_SWAP_FRAGMENT_INDEXES_3(fragment_table_index,
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sfragment_table_index, indexes);
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} else {
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res = read_fs_bytes(fd, sBlk.s.fragment_table_start,
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length, fragment_table_index);
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if(res == FALSE) {
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ERROR("read_fragment_table: failed to read fragment "
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"table index\n");
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return FALSE;
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}
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}
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for(i = 0; i < indexes; i++) {
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int expected = (i + 1) != indexes ? SQUASHFS_METADATA_SIZE :
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bytes & (SQUASHFS_METADATA_SIZE - 1);
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int length = read_block(fd, fragment_table_index[i], NULL,
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expected, ((char *) fragment_table) + ((long long) i *
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SQUASHFS_METADATA_SIZE));
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TRACE("Read fragment table block %d, from 0x%llx, length %d\n",
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i, fragment_table_index[i], length);
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if(length == FALSE) {
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ERROR("read_fragment_table: failed to read fragment "
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"table block\n");
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return FALSE;
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}
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}
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if(swap) {
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squashfs_fragment_entry_3 sfragment;
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for(i = 0; i < sBlk.s.fragments; i++) {
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SQUASHFS_SWAP_FRAGMENT_ENTRY_3((&sfragment),
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(&fragment_table[i]));
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memcpy((char *) &fragment_table[i], (char *) &sfragment,
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sizeof(squashfs_fragment_entry_3));
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}
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}
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*table_start = fragment_table_index[0];
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return TRUE;
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}
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static void read_fragment(unsigned int fragment, long long *start_block, int *size)
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{
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TRACE("read_fragment: reading fragment %d\n", fragment);
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squashfs_fragment_entry_3 *fragment_entry = &fragment_table[fragment];
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*start_block = fragment_entry->start_block;
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*size = fragment_entry->size;
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}
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static struct inode *read_inode(unsigned int start_block, unsigned int offset)
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{
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static union squashfs_inode_header_3 header;
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long long start = sBlk.s.inode_table_start + start_block;
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int bytes = lookup_entry(inode_table_hash, start);
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char *block_ptr = inode_table + bytes + offset;
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static struct inode i;
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TRACE("read_inode: reading inode [%d:%d]\n", start_block, offset);
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if(bytes == -1)
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EXIT_UNSQUASH("read_inode: inode table block %lld not found\n",
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start);
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if(swap) {
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squashfs_base_inode_header_3 sinode;
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memcpy(&sinode, block_ptr, sizeof(header.base));
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SQUASHFS_SWAP_BASE_INODE_HEADER_3(&header.base, &sinode,
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sizeof(squashfs_base_inode_header_3));
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} else
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memcpy(&header.base, block_ptr, sizeof(header.base));
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i.xattr = SQUASHFS_INVALID_XATTR;
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i.uid = (uid_t) uid_table[header.base.uid];
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i.gid = header.base.guid == SQUASHFS_GUIDS ? i.uid :
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(uid_t) guid_table[header.base.guid];
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i.mode = lookup_type[header.base.inode_type] | header.base.mode;
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i.type = header.base.inode_type;
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i.time = header.base.mtime;
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i.inode_number = header.base.inode_number;
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switch(header.base.inode_type) {
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case SQUASHFS_DIR_TYPE: {
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squashfs_dir_inode_header_3 *inode = &header.dir;
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if(swap) {
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squashfs_dir_inode_header_3 sinode;
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memcpy(&sinode, block_ptr, sizeof(header.dir));
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SQUASHFS_SWAP_DIR_INODE_HEADER_3(&header.dir,
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&sinode);
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} else
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memcpy(&header.dir, block_ptr,
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sizeof(header.dir));
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i.data = inode->file_size;
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i.offset = inode->offset;
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i.start = inode->start_block;
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break;
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}
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case SQUASHFS_LDIR_TYPE: {
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squashfs_ldir_inode_header_3 *inode = &header.ldir;
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if(swap) {
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squashfs_ldir_inode_header_3 sinode;
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memcpy(&sinode, block_ptr, sizeof(header.ldir));
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SQUASHFS_SWAP_LDIR_INODE_HEADER_3(&header.ldir,
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&sinode);
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} else
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memcpy(&header.ldir, block_ptr,
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sizeof(header.ldir));
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i.data = inode->file_size;
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i.offset = inode->offset;
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i.start = inode->start_block;
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break;
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}
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case SQUASHFS_FILE_TYPE: {
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squashfs_reg_inode_header_3 *inode = &header.reg;
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if(swap) {
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squashfs_reg_inode_header_3 sinode;
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memcpy(&sinode, block_ptr, sizeof(sinode));
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SQUASHFS_SWAP_REG_INODE_HEADER_3(inode,
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&sinode);
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} else
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memcpy(inode, block_ptr, sizeof(*inode));
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i.data = inode->file_size;
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i.frag_bytes = inode->fragment == SQUASHFS_INVALID_FRAG
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? 0 : inode->file_size % sBlk.s.block_size;
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i.fragment = inode->fragment;
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i.offset = inode->offset;
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i.blocks = inode->fragment == SQUASHFS_INVALID_FRAG ?
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(i.data + sBlk.s.block_size - 1) >>
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sBlk.s.block_log :
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i.data >> sBlk.s.block_log;
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i.start = inode->start_block;
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i.sparse = 1;
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i.block_ptr = block_ptr + sizeof(*inode);
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break;
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}
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case SQUASHFS_LREG_TYPE: {
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squashfs_lreg_inode_header_3 *inode = &header.lreg;
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if(swap) {
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squashfs_lreg_inode_header_3 sinode;
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memcpy(&sinode, block_ptr, sizeof(sinode));
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SQUASHFS_SWAP_LREG_INODE_HEADER_3(inode,
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&sinode);
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} else
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memcpy(inode, block_ptr, sizeof(*inode));
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i.data = inode->file_size;
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i.frag_bytes = inode->fragment == SQUASHFS_INVALID_FRAG
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? 0 : inode->file_size % sBlk.s.block_size;
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i.fragment = inode->fragment;
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i.offset = inode->offset;
|
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i.blocks = inode->fragment == SQUASHFS_INVALID_FRAG ?
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(inode->file_size + sBlk.s.block_size - 1) >>
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sBlk.s.block_log :
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inode->file_size >> sBlk.s.block_log;
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i.start = inode->start_block;
|
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i.sparse = 1;
|
||||
i.block_ptr = block_ptr + sizeof(*inode);
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||||
break;
|
||||
}
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case SQUASHFS_SYMLINK_TYPE: {
|
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squashfs_symlink_inode_header_3 *inodep =
|
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&header.symlink;
|
||||
|
||||
if(swap) {
|
||||
squashfs_symlink_inode_header_3 sinodep;
|
||||
memcpy(&sinodep, block_ptr, sizeof(sinodep));
|
||||
SQUASHFS_SWAP_SYMLINK_INODE_HEADER_3(inodep,
|
||||
&sinodep);
|
||||
} else
|
||||
memcpy(inodep, block_ptr, sizeof(*inodep));
|
||||
|
||||
i.symlink = malloc(inodep->symlink_size + 1);
|
||||
if(i.symlink == NULL)
|
||||
EXIT_UNSQUASH("read_inode: failed to malloc "
|
||||
"symlink data\n");
|
||||
strncpy(i.symlink, block_ptr +
|
||||
sizeof(squashfs_symlink_inode_header_3),
|
||||
inodep->symlink_size);
|
||||
i.symlink[inodep->symlink_size] = '\0';
|
||||
i.data = inodep->symlink_size;
|
||||
break;
|
||||
}
|
||||
case SQUASHFS_BLKDEV_TYPE:
|
||||
case SQUASHFS_CHRDEV_TYPE: {
|
||||
squashfs_dev_inode_header_3 *inodep = &header.dev;
|
||||
|
||||
if(swap) {
|
||||
squashfs_dev_inode_header_3 sinodep;
|
||||
memcpy(&sinodep, block_ptr, sizeof(sinodep));
|
||||
SQUASHFS_SWAP_DEV_INODE_HEADER_3(inodep,
|
||||
&sinodep);
|
||||
} else
|
||||
memcpy(inodep, block_ptr, sizeof(*inodep));
|
||||
|
||||
i.data = inodep->rdev;
|
||||
break;
|
||||
}
|
||||
case SQUASHFS_FIFO_TYPE:
|
||||
case SQUASHFS_SOCKET_TYPE:
|
||||
i.data = 0;
|
||||
break;
|
||||
default:
|
||||
EXIT_UNSQUASH("Unknown inode type %d in read_inode!\n",
|
||||
header.base.inode_type);
|
||||
}
|
||||
return &i;
|
||||
}
|
||||
|
||||
|
||||
static struct dir *squashfs_opendir(unsigned int block_start, unsigned int offset,
|
||||
struct inode **i)
|
||||
{
|
||||
squashfs_dir_header_3 dirh;
|
||||
char buffer[sizeof(squashfs_dir_entry_3) + SQUASHFS_NAME_LEN + 1]
|
||||
__attribute__((aligned));
|
||||
squashfs_dir_entry_3 *dire = (squashfs_dir_entry_3 *) buffer;
|
||||
long long start;
|
||||
int bytes;
|
||||
int dir_count, size;
|
||||
struct dir_ent *new_dir;
|
||||
struct dir *dir;
|
||||
|
||||
TRACE("squashfs_opendir: inode start block %d, offset %d\n",
|
||||
block_start, offset);
|
||||
|
||||
*i = read_inode(block_start, offset);
|
||||
|
||||
dir = malloc(sizeof(struct dir));
|
||||
if(dir == NULL)
|
||||
EXIT_UNSQUASH("squashfs_opendir: malloc failed!\n");
|
||||
|
||||
dir->dir_count = 0;
|
||||
dir->cur_entry = 0;
|
||||
dir->mode = (*i)->mode;
|
||||
dir->uid = (*i)->uid;
|
||||
dir->guid = (*i)->gid;
|
||||
dir->mtime = (*i)->time;
|
||||
dir->xattr = (*i)->xattr;
|
||||
dir->dirs = NULL;
|
||||
|
||||
if ((*i)->data == 3)
|
||||
/*
|
||||
* if the directory is empty, skip the unnecessary
|
||||
* lookup_entry, this fixes the corner case with
|
||||
* completely empty filesystems where lookup_entry correctly
|
||||
* returning -1 is incorrectly treated as an error
|
||||
*/
|
||||
return dir;
|
||||
|
||||
start = sBlk.s.directory_table_start + (*i)->start;
|
||||
bytes = lookup_entry(directory_table_hash, start);
|
||||
|
||||
if(bytes == -1)
|
||||
EXIT_UNSQUASH("squashfs_opendir: directory block %d not "
|
||||
"found!\n", block_start);
|
||||
|
||||
bytes += (*i)->offset;
|
||||
size = (*i)->data + bytes - 3;
|
||||
|
||||
while(bytes < size) {
|
||||
if(swap) {
|
||||
squashfs_dir_header_3 sdirh;
|
||||
memcpy(&sdirh, directory_table + bytes, sizeof(sdirh));
|
||||
SQUASHFS_SWAP_DIR_HEADER_3(&dirh, &sdirh);
|
||||
} else
|
||||
memcpy(&dirh, directory_table + bytes, sizeof(dirh));
|
||||
|
||||
dir_count = dirh.count + 1;
|
||||
TRACE("squashfs_opendir: Read directory header @ byte position "
|
||||
"%d, %d directory entries\n", bytes, dir_count);
|
||||
bytes += sizeof(dirh);
|
||||
|
||||
/* dir_count should never be larger than SQUASHFS_DIR_COUNT */
|
||||
if(dir_count > SQUASHFS_DIR_COUNT) {
|
||||
ERROR("File system corrupted: too many entries in directory\n");
|
||||
goto corrupted;
|
||||
}
|
||||
|
||||
while(dir_count--) {
|
||||
if(swap) {
|
||||
squashfs_dir_entry_3 sdire;
|
||||
memcpy(&sdire, directory_table + bytes,
|
||||
sizeof(sdire));
|
||||
SQUASHFS_SWAP_DIR_ENTRY_3(dire, &sdire);
|
||||
} else
|
||||
memcpy(dire, directory_table + bytes,
|
||||
sizeof(*dire));
|
||||
bytes += sizeof(*dire);
|
||||
|
||||
/* size should never be SQUASHFS_NAME_LEN or larger */
|
||||
if(dire->size >= SQUASHFS_NAME_LEN) {
|
||||
ERROR("File system corrupted: filename too long\n");
|
||||
goto corrupted;
|
||||
}
|
||||
|
||||
memcpy(dire->name, directory_table + bytes,
|
||||
dire->size + 1);
|
||||
dire->name[dire->size + 1] = '\0';
|
||||
TRACE("squashfs_opendir: directory entry %s, inode "
|
||||
"%d:%d, type %d\n", dire->name,
|
||||
dirh.start_block, dire->offset, dire->type);
|
||||
if((dir->dir_count % DIR_ENT_SIZE) == 0) {
|
||||
new_dir = realloc(dir->dirs, (dir->dir_count +
|
||||
DIR_ENT_SIZE) * sizeof(struct dir_ent));
|
||||
if(new_dir == NULL)
|
||||
EXIT_UNSQUASH("squashfs_opendir: "
|
||||
"realloc failed!\n");
|
||||
dir->dirs = new_dir;
|
||||
}
|
||||
strcpy(dir->dirs[dir->dir_count].name, dire->name);
|
||||
dir->dirs[dir->dir_count].start_block =
|
||||
dirh.start_block;
|
||||
dir->dirs[dir->dir_count].offset = dire->offset;
|
||||
dir->dirs[dir->dir_count].type = dire->type;
|
||||
dir->dir_count ++;
|
||||
bytes += dire->size + 1;
|
||||
}
|
||||
}
|
||||
|
||||
return dir;
|
||||
|
||||
corrupted:
|
||||
free(dir->dirs);
|
||||
free(dir);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
|
||||
static int parse_exports_table(long long *table_start)
|
||||
{
|
||||
/*
|
||||
* Note on overflow limits:
|
||||
* Size of SBlk.s.inodes is 2^32 (unsigned int)
|
||||
* Max indexes is (2^32*8)/8K or 2^22
|
||||
* Max length is ((2^32*8)/8K)*8 or 2^25
|
||||
*/
|
||||
int res;
|
||||
int indexes = SQUASHFS_LOOKUP_BLOCKS_3((long long) sBlk.s.inodes);
|
||||
int length = SQUASHFS_LOOKUP_BLOCK_BYTES_3((long long) sBlk.s.inodes);
|
||||
long long *export_index_table;
|
||||
|
||||
/*
|
||||
* The size of the index table (length bytes) should match the
|
||||
* table start and end points
|
||||
*/
|
||||
if(length != (*table_start - sBlk.s.lookup_table_start)) {
|
||||
ERROR("parse_exports_table: Bad inode count in super block\n");
|
||||
return FALSE;
|
||||
}
|
||||
|
||||
export_index_table = alloc_index_table(indexes);
|
||||
|
||||
if(swap) {
|
||||
long long *sexport_index_table = salloc_index_table(indexes);
|
||||
|
||||
res = read_fs_bytes(fd, sBlk.s.lookup_table_start,
|
||||
length, sexport_index_table);
|
||||
if(res == FALSE) {
|
||||
ERROR("parse_exorts_table: failed to read export "
|
||||
"index table\n");
|
||||
return FALSE;
|
||||
}
|
||||
SQUASHFS_SWAP_LOOKUP_BLOCKS_3(export_index_table,
|
||||
sexport_index_table, indexes);
|
||||
} else {
|
||||
res = read_fs_bytes(fd, sBlk.s.lookup_table_start, length,
|
||||
export_index_table);
|
||||
if(res == FALSE) {
|
||||
ERROR("parse_exorts_table: failed to read export "
|
||||
"index table\n");
|
||||
return FALSE;
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* export_index_table[0] stores the start of the compressed export blocks.
|
||||
* This by definition is also the end of the previous filesystem
|
||||
* table - the fragment table.
|
||||
*/
|
||||
*table_start = export_index_table[0];
|
||||
|
||||
return TRUE;
|
||||
}
|
||||
|
||||
|
||||
squashfs_operations *read_filesystem_tables_3()
|
||||
{
|
||||
long long table_start;
|
||||
|
||||
/* Read uid and gid lookup tables */
|
||||
|
||||
/* Sanity check super block contents */
|
||||
if(sBlk.no_guids) {
|
||||
if(sBlk.guid_start >= sBlk.s.bytes_used) {
|
||||
ERROR("read_filesystem_tables: gid start too large in super block\n");
|
||||
goto corrupted;
|
||||
}
|
||||
|
||||
if(read_ids(sBlk.no_guids, sBlk.guid_start, sBlk.s.bytes_used, &guid_table) == FALSE)
|
||||
goto corrupted;
|
||||
|
||||
table_start = sBlk.guid_start;
|
||||
} else {
|
||||
/* no guids, guid_start should be 0 */
|
||||
if(sBlk.guid_start != 0) {
|
||||
ERROR("read_filesystem_tables: gid start too large in super block\n");
|
||||
goto corrupted;
|
||||
}
|
||||
|
||||
table_start = sBlk.s.bytes_used;
|
||||
}
|
||||
|
||||
if(sBlk.uid_start >= table_start) {
|
||||
ERROR("read_filesystem_tables: uid start too large in super block\n");
|
||||
goto corrupted;
|
||||
}
|
||||
|
||||
/* There should be at least one uid */
|
||||
if(sBlk.no_uids == 0) {
|
||||
ERROR("read_filesystem_tables: uid count bad in super block\n");
|
||||
goto corrupted;
|
||||
}
|
||||
|
||||
if(read_ids(sBlk.no_uids, sBlk.uid_start, table_start, &uid_table) == FALSE)
|
||||
goto corrupted;
|
||||
|
||||
table_start = sBlk.uid_start;
|
||||
|
||||
/* Read exports table */
|
||||
if(sBlk.s.lookup_table_start != SQUASHFS_INVALID_BLK) {
|
||||
|
||||
/* sanity check super block contents */
|
||||
if(sBlk.s.lookup_table_start >= table_start) {
|
||||
ERROR("read_filesystem_tables: lookup table start too large in super block\n");
|
||||
goto corrupted;
|
||||
}
|
||||
|
||||
if(parse_exports_table(&table_start) == FALSE)
|
||||
goto corrupted;
|
||||
}
|
||||
|
||||
/* Read fragment table */
|
||||
if(sBlk.s.fragments != 0) {
|
||||
|
||||
/* Sanity check super block contents */
|
||||
if(sBlk.s.fragment_table_start >= table_start) {
|
||||
ERROR("read_filesystem_tables: fragment table start too large in super block\n");
|
||||
goto corrupted;
|
||||
}
|
||||
|
||||
/* The number of fragments should not exceed the number of inodes */
|
||||
if(sBlk.s.fragments > sBlk.s.inodes) {
|
||||
ERROR("read_filesystem_tables: Bad fragment count in super block\n");
|
||||
goto corrupted;
|
||||
}
|
||||
|
||||
if(read_fragment_table(&table_start) == FALSE)
|
||||
goto corrupted;
|
||||
} else {
|
||||
/*
|
||||
* Sanity check super block contents - with 0 fragments,
|
||||
* the fragment table should be empty
|
||||
*/
|
||||
if(sBlk.s.fragment_table_start != table_start) {
|
||||
ERROR("read_filesystem_tables: fragment table start invalid in super block\n");
|
||||
goto corrupted;
|
||||
}
|
||||
}
|
||||
|
||||
/* Read directory table */
|
||||
|
||||
/* Sanity check super block contents */
|
||||
if(sBlk.s.directory_table_start > table_start) {
|
||||
ERROR("read_filesystem_tables: directory table start too large in super block\n");
|
||||
goto corrupted;
|
||||
}
|
||||
|
||||
directory_table = read_directory_table(sBlk.s.directory_table_start,
|
||||
table_start);
|
||||
if(directory_table == NULL)
|
||||
goto corrupted;
|
||||
|
||||
/* Read inode table */
|
||||
|
||||
/* Sanity check super block contents */
|
||||
if(sBlk.s.inode_table_start >= sBlk.s.directory_table_start) {
|
||||
ERROR("read_filesystem_tables: inode table start too large in super block\n");
|
||||
goto corrupted;
|
||||
}
|
||||
|
||||
inode_table = read_inode_table(sBlk.s.inode_table_start,
|
||||
sBlk.s.directory_table_start);
|
||||
if(inode_table == NULL)
|
||||
goto corrupted;
|
||||
|
||||
alloc_index_table(0);
|
||||
salloc_index_table(0);
|
||||
|
||||
return &ops;
|
||||
|
||||
corrupted:
|
||||
ERROR("File system corruption detected\n");
|
||||
alloc_index_table(0);
|
||||
salloc_index_table(0);
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
||||
|
||||
static squashfs_operations ops = {
|
||||
.opendir = squashfs_opendir,
|
||||
.read_fragment = read_fragment,
|
||||
.read_block_list = read_block_list,
|
||||
.read_inode = read_inode
|
||||
};
|
Loading…
Add table
Add a link
Reference in a new issue