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/////////////////////////////////////////////////////////////////////////////// |
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// |
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/// \file block_header.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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|
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#include "common.h" |
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#include "index.h" |
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|
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|
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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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|
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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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|
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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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|
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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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|
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block->compressed_size = compressed_size; |
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|
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return LZMA_OK; |
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} |
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|
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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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|
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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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|
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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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|
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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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|
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return unpadded_size; |
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} |
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|
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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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|
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if (unpadded_size != LZMA_VLI_UNKNOWN) |
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unpadded_size = vli_ceil4(unpadded_size); |
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|
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return unpadded_size; |
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} |
