Add an unpatched version of xz, XZ Utils, to /trunk/deps/third_party

xz/src/liblzma/common/stream_decoder.c

Index: xz/src/liblzma/common/stream_decoder.c
===================================================================
--- xz/src/liblzma/common/stream_decoder.c	(revision 0)
+++ xz/src/liblzma/common/stream_decoder.c	(revision 0)
@@ -0,0 +1,451 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       stream_decoder.c
+/// \brief      Decodes .xz Streams
+//
+//  Author:     Lasse Collin
+//
+//  This file has been put into the public domain.
+//  You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "stream_decoder.h"
+#include "block_decoder.h"
+
+
+struct lzma_coder_s {
+	enum {
+		SEQ_STREAM_HEADER,
+		SEQ_BLOCK_HEADER,
+		SEQ_BLOCK,
+		SEQ_INDEX,
+		SEQ_STREAM_FOOTER,
+		SEQ_STREAM_PADDING,
+	} sequence;
+
+	/// Block or Metadata decoder. This takes little memory and the same
+	/// data structure can be used to decode every Block Header, so it's
+	/// a good idea to have a separate lzma_next_coder structure for it.
+	lzma_next_coder block_decoder;
+
+	/// Block options decoded by the Block Header decoder and used by
+	/// the Block decoder.
+	lzma_block block_options;
+
+	/// Stream Flags from Stream Header
+	lzma_stream_flags stream_flags;
+
+	/// Index is hashed so that it can be compared to the sizes of Blocks
+	/// with O(1) memory usage.
+	lzma_index_hash *index_hash;
+
+	/// Memory usage limit
+	uint64_t memlimit;
+
+	/// Amount of memory actually needed (only an estimate)
+	uint64_t memusage;
+
+	/// If true, LZMA_NO_CHECK is returned if the Stream has
+	/// no integrity check.
+	bool tell_no_check;
+
+	/// If true, LZMA_UNSUPPORTED_CHECK is returned if the Stream has
+	/// an integrity check that isn't supported by this liblzma build.
+	bool tell_unsupported_check;
+
+	/// If true, LZMA_GET_CHECK is returned after decoding Stream Header.
+	bool tell_any_check;
+
+	/// If true, we will decode concatenated Streams that possibly have
+	/// Stream Padding between or after them. LZMA_STREAM_END is returned
+	/// once the application isn't giving us any new input, and we aren't
+	/// in the middle of a Stream, and possible Stream Padding is a
+	/// multiple of four bytes.
+	bool concatenated;
+
+	/// When decoding concatenated Streams, this is true as long as we
+	/// are decoding the first Stream. This is needed to avoid misleading
+	/// LZMA_FORMAT_ERROR in case the later Streams don't have valid magic
+	/// bytes.
+	bool first_stream;
+
+	/// Write position in buffer[] and position in Stream Padding
+	size_t pos;
+
+	/// Buffer to hold Stream Header, Block Header, and Stream Footer.
+	/// Block Header has biggest maximum size.
+	uint8_t buffer[LZMA_BLOCK_HEADER_SIZE_MAX];
+};
+
+
+static lzma_ret
+stream_decoder_reset(lzma_coder *coder, lzma_allocator *allocator)
+{
+	// Initialize the Index hash used to verify the Index.
+	coder->index_hash = lzma_index_hash_init(coder->index_hash, allocator);
+	if (coder->index_hash == NULL)
+		return LZMA_MEM_ERROR;
+
+	// Reset the rest of the variables.
+	coder->sequence = SEQ_STREAM_HEADER;
+	coder->pos = 0;
+
+	return LZMA_OK;
+}
+
+
+static lzma_ret
+stream_decode(lzma_coder *coder, lzma_allocator *allocator,
+		const uint8_t *restrict in, size_t *restrict in_pos,
+		size_t in_size, uint8_t *restrict out,
+		size_t *restrict out_pos, size_t out_size, lzma_action action)
+{
+	// When decoding the actual Block, it may be able to produce more
+	// output even if we don't give it any new input.
+	while (true)
+	switch (coder->sequence) {
+	case SEQ_STREAM_HEADER: {
+		// Copy the Stream Header to the internal buffer.
+		lzma_bufcpy(in, in_pos, in_size, coder->buffer, &coder->pos,
+				LZMA_STREAM_HEADER_SIZE);
+
+		// Return if we didn't get the whole Stream Header yet.
+		if (coder->pos < LZMA_STREAM_HEADER_SIZE)
+			return LZMA_OK;
+
+		coder->pos = 0;
+
+		// Decode the Stream Header.
+		const lzma_ret ret = lzma_stream_header_decode(
+				&coder->stream_flags, coder->buffer);
+		if (ret != LZMA_OK)
+			return ret == LZMA_FORMAT_ERROR && !coder->first_stream
+					? LZMA_DATA_ERROR : ret;
+
+		// If we are decoding concatenated Streams, and the later
+		// Streams have invalid Header Magic Bytes, we give
+		// LZMA_DATA_ERROR instead of LZMA_FORMAT_ERROR.
+		coder->first_stream = false;
+
+		// Copy the type of the Check so that Block Header and Block
+		// decoders see it.
+		coder->block_options.check = coder->stream_flags.check;
+
+		// Even if we return LZMA_*_CHECK below, we want
+		// to continue from Block Header decoding.
+		coder->sequence = SEQ_BLOCK_HEADER;
+
+		// Detect if there's no integrity check or if it is
+		// unsupported if those were requested by the application.
+		if (coder->tell_no_check && coder->stream_flags.check
+				== LZMA_CHECK_NONE)
+			return LZMA_NO_CHECK;
+
+		if (coder->tell_unsupported_check
+				&& !lzma_check_is_supported(
+					coder->stream_flags.check))
+			return LZMA_UNSUPPORTED_CHECK;
+
+		if (coder->tell_any_check)
+			return LZMA_GET_CHECK;
+	}
+
+	// Fall through
+
+	case SEQ_BLOCK_HEADER: {
+		if (*in_pos >= in_size)
+			return LZMA_OK;
+
+		if (coder->pos == 0) {
+			// Detect if it's Index.
+			if (in[*in_pos] == 0x00) {
+				coder->sequence = SEQ_INDEX;
+				break;
+			}
+
+			// Calculate the size of the Block Header. Note that
+			// Block Header decoder wants to see this byte too
+			// so don't advance *in_pos.
+			coder->block_options.header_size
+					= lzma_block_header_size_decode(
+						in[*in_pos]);
+		}
+
+		// Copy the Block Header to the internal buffer.
+		lzma_bufcpy(in, in_pos, in_size, coder->buffer, &coder->pos,
+				coder->block_options.header_size);
+
+		// Return if we didn't get the whole Block Header yet.
+		if (coder->pos < coder->block_options.header_size)
+			return LZMA_OK;
+
+		coder->pos = 0;
+
+		// Version 0 is currently the only possible version.
+		coder->block_options.version = 0;
+
+		// Set up a buffer to hold the filter chain. Block Header
+		// decoder will initialize all members of this array so
+		// we don't need to do it here.
+		lzma_filter filters[LZMA_FILTERS_MAX + 1];
+		coder->block_options.filters = filters;
+
+		// Decode the Block Header.
+		return_if_error(lzma_block_header_decode(&coder->block_options,
+				allocator, coder->buffer));
+
+		// Check the memory usage limit.
+		const uint64_t memusage = lzma_raw_decoder_memusage(filters);
+		lzma_ret ret;
+
+		if (memusage == UINT64_MAX) {
+			// One or more unknown Filter IDs.
+			ret = LZMA_OPTIONS_ERROR;
+		} else {
+			// Now we can set coder->memusage since we know that
+			// the filter chain is valid. We don't want
+			// lzma_memusage() to return UINT64_MAX in case of
+			// invalid filter chain.
+			coder->memusage = memusage;
+
+			if (memusage > coder->memlimit) {
+				// The chain would need too much memory.
+				ret = LZMA_MEMLIMIT_ERROR;
+			} else {
+				// Memory usage is OK.
+				// Initialize the Block decoder.
+				ret = lzma_block_decoder_init(
+						&coder->block_decoder,
+						allocator,
+						&coder->block_options);
+			}
+		}
+
+		// Free the allocated filter options since they are needed
+		// only to initialize the Block decoder.
+		for (size_t i = 0; i < LZMA_FILTERS_MAX; ++i)
+			lzma_free(filters[i].options, allocator);
+
+		coder->block_options.filters = NULL;
+
+		// Check if memory usage calculation and Block enocoder
+		// initialization succeeded.
+		if (ret != LZMA_OK)
+			return ret;
+
+		coder->sequence = SEQ_BLOCK;
+	}
+
+	// Fall through
+
+	case SEQ_BLOCK: {
+		const lzma_ret ret = coder->block_decoder.code(
+				coder->block_decoder.coder, allocator,
+				in, in_pos, in_size, out, out_pos, out_size,
+				action);
+
+		if (ret != LZMA_STREAM_END)
+			return ret;
+
+		// Block decoded successfully. Add the new size pair to
+		// the Index hash.
+		return_if_error(lzma_index_hash_append(coder->index_hash,
+				lzma_block_unpadded_size(
+					&coder->block_options),
+				coder->block_options.uncompressed_size));
+
+		coder->sequence = SEQ_BLOCK_HEADER;
+		break;
+	}
+
+	case SEQ_INDEX: {
+		// If we don't have any input, don't call
+		// lzma_index_hash_decode() since it would return
+		// LZMA_BUF_ERROR, which we must not do here.
+		if (*in_pos >= in_size)
+			return LZMA_OK;
+
+		// Decode the Index and compare it to the hash calculated
+		// from the sizes of the Blocks (if any).
+		const lzma_ret ret = lzma_index_hash_decode(coder->index_hash,
+				in, in_pos, in_size);
+		if (ret != LZMA_STREAM_END)
+			return ret;
+
+		coder->sequence = SEQ_STREAM_FOOTER;
+	}
+
+	// Fall through
+
+	case SEQ_STREAM_FOOTER: {
+		// Copy the Stream Footer to the internal buffer.
+		lzma_bufcpy(in, in_pos, in_size, coder->buffer, &coder->pos,
+				LZMA_STREAM_HEADER_SIZE);
+
+		// Return if we didn't get the whole Stream Footer yet.
+		if (coder->pos < LZMA_STREAM_HEADER_SIZE)
+			return LZMA_OK;
+
+		coder->pos = 0;
+
+		// Decode the Stream Footer. The decoder gives
+		// LZMA_FORMAT_ERROR if the magic bytes don't match,
+		// so convert that return code to LZMA_DATA_ERROR.
+		lzma_stream_flags footer_flags;
+		const lzma_ret ret = lzma_stream_footer_decode(
+				&footer_flags, coder->buffer);
+		if (ret != LZMA_OK)
+			return ret == LZMA_FORMAT_ERROR
+					? LZMA_DATA_ERROR : ret;
+
+		// Check that Index Size stored in the Stream Footer matches
+		// the real size of the Index field.
+		if (lzma_index_hash_size(coder->index_hash)
+				!= footer_flags.backward_size)
+			return LZMA_DATA_ERROR;
+
+		// Compare that the Stream Flags fields are identical in
+		// both Stream Header and Stream Footer.
+		return_if_error(lzma_stream_flags_compare(
+				&coder->stream_flags, &footer_flags));
+
+		if (!coder->concatenated)
+			return LZMA_STREAM_END;
+
+		coder->sequence = SEQ_STREAM_PADDING;
+	}
+
+	// Fall through
+
+	case SEQ_STREAM_PADDING:
+		assert(coder->concatenated);
+
+		// Skip over possible Stream Padding.
+		while (true) {
+			if (*in_pos >= in_size) {
+				// Unless LZMA_FINISH was used, we cannot
+				// know if there's more input coming later.
+				if (action != LZMA_FINISH)
+					return LZMA_OK;
+
+				// Stream Padding must be a multiple of
+				// four bytes.
+				return coder->pos == 0
+						? LZMA_STREAM_END
+						: LZMA_DATA_ERROR;
+			}
+
+			// If the byte is not zero, it probably indicates
+			// beginning of a new Stream (or the file is corrupt).
+			if (in[*in_pos] != 0x00)
+				break;
+
+			++*in_pos;
+			coder->pos = (coder->pos + 1) & 3;
+		}
+
+		// Stream Padding must be a multiple of four bytes (empty
+		// Stream Padding is OK).
+		if (coder->pos != 0) {
+			++*in_pos;
+			return LZMA_DATA_ERROR;
+		}
+
+		// Prepare to decode the next Stream.
+		return_if_error(stream_decoder_reset(coder, allocator));
+		break;
+
+	default:
+		assert(0);
+		return LZMA_PROG_ERROR;
+	}
+
+	// Never reached
+}
+
+
+static void
+stream_decoder_end(lzma_coder *coder, lzma_allocator *allocator)
+{
+	lzma_next_end(&coder->block_decoder, allocator);
+	lzma_index_hash_end(coder->index_hash, allocator);
+	lzma_free(coder, allocator);
+	return;
+}
+
+
+static lzma_check
+stream_decoder_get_check(const lzma_coder *coder)
+{
+	return coder->stream_flags.check;
+}
+
+
+static lzma_ret
+stream_decoder_memconfig(lzma_coder *coder, uint64_t *memusage,
+		uint64_t *old_memlimit, uint64_t new_memlimit)
+{
+	*memusage = coder->memusage;
+	*old_memlimit = coder->memlimit;
+
+	if (new_memlimit != 0) {
+		if (new_memlimit < coder->memusage)
+			return LZMA_MEMLIMIT_ERROR;
+
+		coder->memlimit = new_memlimit;
+	}
+
+	return LZMA_OK;
+}
+
+
+extern lzma_ret
+lzma_stream_decoder_init(lzma_next_coder *next, lzma_allocator *allocator,
+		uint64_t memlimit, uint32_t flags)
+{
+	lzma_next_coder_init(&lzma_stream_decoder_init, next, allocator);
+
+	if (memlimit == 0)
+		return LZMA_PROG_ERROR;
+
+	if (flags & ~LZMA_SUPPORTED_FLAGS)
+		return LZMA_OPTIONS_ERROR;
+
+	if (next->coder == NULL) {
+		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
+		if (next->coder == NULL)
+			return LZMA_MEM_ERROR;
+
+		next->code = &stream_decode;
+		next->end = &stream_decoder_end;
+		next->get_check = &stream_decoder_get_check;
+		next->memconfig = &stream_decoder_memconfig;
+
+		next->coder->block_decoder = LZMA_NEXT_CODER_INIT;
+		next->coder->index_hash = NULL;
+	}
+
+	next->coder->memlimit = memlimit;
+	next->coder->memusage = LZMA_MEMUSAGE_BASE;
+	next->coder->tell_no_check = (flags & LZMA_TELL_NO_CHECK) != 0;
+	next->coder->tell_unsupported_check
+			= (flags & LZMA_TELL_UNSUPPORTED_CHECK) != 0;
+	next->coder->tell_any_check = (flags & LZMA_TELL_ANY_CHECK) != 0;
+	next->coder->concatenated = (flags & LZMA_CONCATENATED) != 0;
+	next->coder->first_stream = true;
+
+	return stream_decoder_reset(next->coder, allocator);
+}
+
+
+extern LZMA_API(lzma_ret)
+lzma_stream_decoder(lzma_stream *strm, uint64_t memlimit, uint32_t flags)
+{
+	lzma_next_strm_init(lzma_stream_decoder_init, strm, memlimit, flags);
+
+	strm->internal->supported_actions[LZMA_RUN] = true;
+	strm->internal->supported_actions[LZMA_FINISH] = true;
+
+	return LZMA_OK;
+}
Property changes on: xz/src/liblzma/common/stream_decoder.c
___________________________________________________________________
Added: svn:eol-style
   + LF