mirror of https://git.tukaani.org/xz.git
91 lines
2.6 KiB
C
91 lines
2.6 KiB
C
///////////////////////////////////////////////////////////////////////////////
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//
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/// \file block_util.c
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/// \brief Utility functions to handle lzma_block
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//
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// Author: Lasse Collin
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//
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// This file has been put into the public domain.
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// You can do whatever you want with this file.
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//
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///////////////////////////////////////////////////////////////////////////////
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#include "common.h"
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#include "index.h"
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extern LZMA_API(lzma_ret)
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lzma_block_compressed_size(lzma_block *block, lzma_vli unpadded_size)
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{
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// Validate everything but Uncompressed Size and filters.
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if (lzma_block_unpadded_size(block) == 0)
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return LZMA_PROG_ERROR;
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const uint32_t container_size = block->header_size
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+ lzma_check_size(block->check);
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// Validate that Compressed Size will be greater than zero.
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if (unpadded_size <= container_size)
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return LZMA_DATA_ERROR;
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// Calculate what Compressed Size is supposed to be.
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// If Compressed Size was present in Block Header,
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// compare that the new value matches it.
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const lzma_vli compressed_size = unpadded_size - container_size;
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if (block->compressed_size != LZMA_VLI_UNKNOWN
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&& block->compressed_size != compressed_size)
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return LZMA_DATA_ERROR;
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block->compressed_size = compressed_size;
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return LZMA_OK;
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}
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extern LZMA_API(lzma_vli)
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lzma_block_unpadded_size(const lzma_block *block)
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{
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// Validate the values that we are interested in i.e. all but
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// Uncompressed Size and the filters.
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//
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// NOTE: This function is used for validation too, so it is
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// essential that these checks are always done even if
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// Compressed Size is unknown.
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if (block == NULL || block->version > 1
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|| block->header_size < LZMA_BLOCK_HEADER_SIZE_MIN
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|| block->header_size > LZMA_BLOCK_HEADER_SIZE_MAX
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|| (block->header_size & 3)
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|| !lzma_vli_is_valid(block->compressed_size)
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|| block->compressed_size == 0
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|| (unsigned int)(block->check) > LZMA_CHECK_ID_MAX)
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return 0;
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// If Compressed Size is unknown, return that we cannot know
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// size of the Block either.
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if (block->compressed_size == LZMA_VLI_UNKNOWN)
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return LZMA_VLI_UNKNOWN;
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// Calculate Unpadded Size and validate it.
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const lzma_vli unpadded_size = block->compressed_size
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+ block->header_size
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+ lzma_check_size(block->check);
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assert(unpadded_size >= UNPADDED_SIZE_MIN);
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if (unpadded_size > UNPADDED_SIZE_MAX)
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return 0;
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return unpadded_size;
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}
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extern LZMA_API(lzma_vli)
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lzma_block_total_size(const lzma_block *block)
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{
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lzma_vli unpadded_size = lzma_block_unpadded_size(block);
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if (unpadded_size != LZMA_VLI_UNKNOWN)
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unpadded_size = vli_ceil4(unpadded_size);
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return unpadded_size;
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}
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