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84 lines
2.2 KiB
C
84 lines
2.2 KiB
C
/*
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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) 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-123.c
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*
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* Helper functions used by unsquash-1, unsquash-2 and unsquash-3.
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*/
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#include "unsquashfs.h"
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#include "squashfs_compat.h"
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int read_ids(int ids, long long start, long long end, unsigned int **id_table)
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{
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/* Note on overflow limits:
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* Size of ids is 2^8
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* Max length is 2^8*4 or 1024
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*/
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int res;
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int length = ids * sizeof(unsigned int);
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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 != (end - start)) {
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ERROR("read_ids: Bad inode count in super block\n");
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return FALSE;
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}
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TRACE("read_ids: no_ids %d\n", ids);
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*id_table = malloc(length);
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if(*id_table == NULL) {
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ERROR("read_ids: failed to allocate uid/gid table\n");
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return FALSE;
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}
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if(swap) {
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unsigned int *sid_table = malloc(length);
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if(sid_table == NULL) {
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ERROR("read_ids: failed to allocate uid/gid table\n");
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return FALSE;
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}
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res = read_fs_bytes(fd, start, length, sid_table);
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if(res == FALSE) {
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ERROR("read_ids: failed to read uid/gid table"
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"\n");
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free(sid_table);
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return FALSE;
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}
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SQUASHFS_SWAP_INTS_3((*id_table), sid_table, ids);
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free(sid_table);
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} else {
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res = read_fs_bytes(fd, start, length, *id_table);
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if(res == FALSE) {
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ERROR("read_ids: failed to read uid/gid table"
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"\n");
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return FALSE;
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}
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}
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return TRUE;
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}
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