diff options
Diffstat (limited to 'lib/sqfshelper/data_reader.c')
| -rw-r--r-- | lib/sqfshelper/data_reader.c | 374 |
1 files changed, 0 insertions, 374 deletions
diff --git a/lib/sqfshelper/data_reader.c b/lib/sqfshelper/data_reader.c deleted file mode 100644 index bf808ba..0000000 --- a/lib/sqfshelper/data_reader.c +++ /dev/null @@ -1,374 +0,0 @@ -/* SPDX-License-Identifier: GPL-3.0-or-later */ -/* - * data_reader.c - * - * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at> - */ -#include "config.h" - -#include "sqfs/block_processor.h" -#include "sqfs/error.h" - -#include "data_reader.h" -#include "highlevel.h" -#include "util.h" - -#include <stdlib.h> -#include <unistd.h> -#include <string.h> -#include <stdio.h> - -struct sqfs_data_reader_t { - sqfs_fragment_t *frag; - sqfs_compressor_t *cmp; - sqfs_block_t *data_block; - sqfs_block_t *frag_block; - - uint64_t current_block; - - sqfs_file_t *file; - - uint32_t num_fragments; - uint32_t current_frag_index; - uint32_t block_size; - - uint8_t scratch[]; -}; - -static int get_block(sqfs_data_reader_t *data, uint64_t off, uint32_t size, - size_t unpacked_size, sqfs_block_t **out) -{ - sqfs_block_t *blk = alloc_flex(sizeof(*blk), 1, unpacked_size); - size_t on_disk_size; - ssize_t ret; - int err; - - if (blk == NULL) - return SQFS_ERROR_ALLOC; - - blk->size = unpacked_size; - - if (SQFS_IS_SPARSE_BLOCK(size)) { - *out = blk; - return 0; - } - - on_disk_size = SQFS_ON_DISK_BLOCK_SIZE(size); - - if (on_disk_size > unpacked_size) - return SQFS_ERROR_OVERFLOW; - - if (SQFS_IS_BLOCK_COMPRESSED(size)) { - err = data->file->read_at(data->file, off, - data->scratch, on_disk_size); - if (err) { - free(blk); - return err; - } - - ret = data->cmp->do_block(data->cmp, data->scratch, - on_disk_size, blk->data, blk->size); - if (ret <= 0) - err = ret < 0 ? ret : SQFS_ERROR_OVERFLOW; - } else { - err = data->file->read_at(data->file, off, - blk->data, on_disk_size); - } - - if (err) { - free(blk); - return err; - } - - *out = blk; - return 0; -} - -static int precache_data_block(sqfs_data_reader_t *data, uint64_t location, - uint32_t size) -{ - int ret; - - if (data->data_block != NULL && data->current_block == location) - return 0; - - free(data->data_block); - - ret = get_block(data, location, size, data->block_size, - &data->data_block); - - if (ret < 0) { - data->data_block = NULL; - return -1; - } - - data->current_block = location; - return 0; -} - -static int precache_fragment_block(sqfs_data_reader_t *data, size_t idx) -{ - int ret; - - if (data->frag_block != NULL && idx == data->current_frag_index) - return 0; - - if (idx >= data->num_fragments) { - fputs("fragment index out of bounds\n", stderr); - return -1; - } - - free(data->frag_block); - - ret = get_block(data, data->frag[idx].start_offset, - data->frag[idx].size, data->block_size, - &data->frag_block); - if (ret < 0) - return -1; - - data->current_frag_index = idx; - return 0; -} - -sqfs_data_reader_t *sqfs_data_reader_create(sqfs_file_t *file, - size_t block_size, - sqfs_compressor_t *cmp) -{ - sqfs_data_reader_t *data = alloc_flex(sizeof(*data), 1, block_size); - - if (data != NULL) { - data->file = file; - data->block_size = block_size; - data->cmp = cmp; - } - - return data; -} - -int sqfs_data_reader_load_fragment_table(sqfs_data_reader_t *data, - const sqfs_super_t *super) -{ - void *raw_frag; - size_t size; - uint32_t i; - int ret; - - free(data->frag_block); - free(data->frag); - - data->frag = NULL; - data->frag_block = NULL; - data->num_fragments = 0; - data->current_frag_index = 0; - - if (super->fragment_entry_count == 0 || - (super->flags & SQFS_FLAG_NO_FRAGMENTS) != 0) { - return 0; - } - - if (super->fragment_table_start >= super->bytes_used) - return SQFS_ERROR_OUT_OF_BOUNDS; - - if (SZ_MUL_OV(sizeof(data->frag[0]), super->fragment_entry_count, - &size)) { - return SQFS_ERROR_OVERFLOW; - } - - ret = sqfs_read_table(data->file, data->cmp, size, - super->fragment_table_start, - super->directory_table_start, - super->fragment_table_start, &raw_frag); - if (ret) - return ret; - - data->num_fragments = super->fragment_entry_count; - data->current_frag_index = super->fragment_entry_count; - data->frag = raw_frag; - - for (i = 0; i < data->num_fragments; ++i) { - data->frag[i].size = le32toh(data->frag[i].size); - data->frag[i].start_offset = - le64toh(data->frag[i].start_offset); - } - - return 0; -} - -void sqfs_data_reader_destroy(sqfs_data_reader_t *data) -{ - free(data->data_block); - free(data->frag_block); - free(data->frag); - free(data); -} - -int sqfs_data_reader_get_block(sqfs_data_reader_t *data, - const sqfs_inode_generic_t *inode, - size_t index, sqfs_block_t **out) -{ - size_t i, unpacked_size; - uint64_t off, filesz; - - if (inode->base.type == SQFS_INODE_FILE) { - off = inode->data.file.blocks_start; - filesz = inode->data.file.file_size; - } else if (inode->base.type == SQFS_INODE_EXT_FILE) { - off = inode->data.file_ext.blocks_start; - filesz = inode->data.file_ext.file_size; - } else { - return SQFS_ERROR_NOT_FILE; - } - - if (index >= inode->num_file_blocks) - return SQFS_ERROR_OUT_OF_BOUNDS; - - for (i = 0; i < index; ++i) { - off += SQFS_ON_DISK_BLOCK_SIZE(inode->block_sizes[i]); - filesz -= data->block_size; - } - - unpacked_size = filesz < data->block_size ? filesz : data->block_size; - - return get_block(data, off, inode->block_sizes[index], - unpacked_size, out); -} - -int sqfs_data_reader_get_fragment(sqfs_data_reader_t *data, - const sqfs_inode_generic_t *inode, - sqfs_block_t **out) -{ - uint32_t frag_idx, frag_off, frag_sz; - sqfs_block_t *blk; - uint64_t filesz; - - if (inode->base.type == SQFS_INODE_EXT_FILE) { - filesz = inode->data.file_ext.file_size; - frag_idx = inode->data.file_ext.fragment_idx; - frag_off = inode->data.file_ext.fragment_offset; - } else if (inode->base.type == SQFS_INODE_FILE) { - filesz = inode->data.file.file_size; - frag_idx = inode->data.file.fragment_index; - frag_off = inode->data.file.fragment_offset; - } else { - return -1; - } - - if (inode->num_file_blocks * data->block_size >= filesz) { - *out = NULL; - return 0; - } - - frag_sz = filesz % data->block_size; - - if (precache_fragment_block(data, frag_idx)) - return -1; - - if (frag_off + frag_sz > data->block_size) - return -1; - - blk = alloc_flex(sizeof(*blk), 1, frag_sz); - if (blk == NULL) - return -1; - - blk->size = frag_sz; - memcpy(blk->data, (char *)data->frag_block->data + frag_off, frag_sz); - - *out = blk; - return 0; -} - -ssize_t sqfs_data_reader_read(sqfs_data_reader_t *data, - const sqfs_inode_generic_t *inode, - uint64_t offset, void *buffer, size_t size) -{ - uint32_t frag_idx, frag_off; - size_t i, diff, total = 0; - uint64_t off, filesz; - char *ptr; - - /* work out file location and size */ - if (inode->base.type == SQFS_INODE_EXT_FILE) { - off = inode->data.file_ext.blocks_start; - filesz = inode->data.file_ext.file_size; - frag_idx = inode->data.file_ext.fragment_idx; - frag_off = inode->data.file_ext.fragment_offset; - } else { - off = inode->data.file.blocks_start; - filesz = inode->data.file.file_size; - frag_idx = inode->data.file.fragment_index; - frag_off = inode->data.file.fragment_offset; - } - - /* find location of the first block */ - i = 0; - - while (offset > data->block_size && i < inode->num_file_blocks) { - off += SQFS_ON_DISK_BLOCK_SIZE(inode->block_sizes[i++]); - offset -= data->block_size; - - if (filesz >= data->block_size) { - filesz -= data->block_size; - } else { - filesz = 0; - } - } - - /* copy data from blocks */ - while (i < inode->num_file_blocks && size > 0 && filesz > 0) { - diff = data->block_size - offset; - if (size < diff) - diff = size; - - if (SQFS_IS_SPARSE_BLOCK(inode->block_sizes[i])) { - memset(buffer, 0, diff); - } else { - if (precache_data_block(data, off, - inode->block_sizes[i])) { - return -1; - } - - memcpy(buffer, (char *)data->data_block->data + offset, - diff); - off += SQFS_ON_DISK_BLOCK_SIZE(inode->block_sizes[i]); - } - - if (filesz >= data->block_size) { - filesz -= data->block_size; - } else { - filesz = 0; - } - - ++i; - offset = 0; - size -= diff; - total += diff; - buffer = (char *)buffer + diff; - } - - /* copy from fragment */ - if (i == inode->num_file_blocks && size > 0 && filesz > 0) { - if (precache_fragment_block(data, frag_idx)) - return -1; - - if (frag_off + filesz > data->block_size) - goto fail_range; - - if (offset >= filesz) - return total; - - if (offset + size > filesz) - size = filesz - offset; - - if (size == 0) - return total; - - ptr = (char *)data->frag_block->data + frag_off + offset; - memcpy(buffer, ptr, size); - total += size; - } - - return total; -fail_range: - fputs("attempted to read past fragment block limits\n", stderr); - return -1; -} |