Imported to git.

1 files changed, 454 insertions, 0 deletions

diff --git a/src/liblzma/common/stream_decoder.c b/src/liblzma/common/stream_decoder.c
new file mode 100644
index 00000000..d8000c3d
--- /dev/null
+++ b/src/liblzma/common/stream_decoder.c
@@ -0,0 +1,454 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       stream_decoder.c
+/// \brief      Decodes .lzma Streams
+//
+//  Copyright (C) 2007 Lasse Collin
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2.1 of the License, or (at your option) any later version.
+//
+//  This library is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+//  Lesser General Public License for more details.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "stream_common.h"
+#include "check.h"
+#include "stream_flags_decoder.h"
+#include "block_decoder.h"
+#include "metadata_decoder.h"
+
+
+struct lzma_coder_s {
+	enum {
+		SEQ_STREAM_HEADER_CODE,
+		SEQ_BLOCK_HEADER_INIT,
+		SEQ_BLOCK_HEADER_CODE,
+		SEQ_METADATA_CODE,
+		SEQ_DATA_CODE,
+		SEQ_STREAM_TAIL_INIT,
+		SEQ_STREAM_TAIL_CODE,
+	} sequence;
+
+	/// Position in variable-length integers and in some other things.
+	size_t pos;
+
+	/// 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 Header decoder; this is separate
+	lzma_next_coder block_header_decoder;
+
+	lzma_options_block block_options;
+
+	/// Information about the sizes of the Blocks
+	lzma_info *info;
+
+	/// Current Block in *info
+	lzma_info_iter iter;
+
+	/// Number of bytes not yet processed from Data Blocks in the Stream.
+	/// This can be LZMA_VLI_VALUE_UNKNOWN. If it is known, it is
+	/// decremented while decoding and verified to match the reality.
+	lzma_vli total_left;
+
+	/// Like uncompressed_left above but for uncompressed data from
+	/// Data Blocks.
+	lzma_vli uncompressed_left;
+
+	/// Stream Flags from Stream Header
+	lzma_stream_flags header_flags;
+
+	/// Stream Flags from Stream tail
+	lzma_stream_flags tail_flags;
+
+	/// Decoder for Stream Header and Stream tail. This takes very
+	/// little memory and the same data structure can be used for
+	/// both Header and tail, so it's a good idea to have a separate
+	/// lzma_next_coder structure for it.
+	lzma_next_coder flags_decoder;
+
+	/// Temporary destination for the decoded Metadata.
+	lzma_metadata metadata;
+
+	/// Pointer to application-supplied pointer where to store the list
+	/// of Extra Records from the Header Metadata Block.
+	lzma_extra **header_extra;
+
+	/// Same as above but Footer Metadata Block
+	lzma_extra **footer_extra;
+};
+
+
+static lzma_ret
+metadata_init(lzma_coder *coder, lzma_allocator *allocator)
+{
+	assert(coder->metadata.index == NULL);
+	assert(coder->metadata.extra == NULL);
+
+	// Single-Block Streams don't have Metadata Blocks.
+	if (!coder->header_flags.is_multi)
+		return LZMA_DATA_ERROR;
+
+	coder->block_options.total_limit = LZMA_VLI_VALUE_UNKNOWN;
+
+	// Limit the Uncompressed Size of a Metadata Block. This is to
+	// prevent security issues where input file would have very huge
+	// Metadata.
+	//
+	// FIXME: Hardcoded constant is ugly. Maybe we should provide
+	// some way to specify this from the application.
+	coder->block_options.uncompressed_limit = LZMA_VLI_C(1) << 23;
+
+	lzma_info_size size_type;
+	bool want_extra;
+
+	// If we haven't decoded any Data Blocks yet, this is Header
+	// Metadata Block.
+	if (lzma_info_index_count_get(coder->info) == 0) {
+		coder->block_options.has_backward_size = false;
+		coder->block_options.handle_padding = true;
+		size_type = LZMA_INFO_HEADER_METADATA;
+		want_extra = coder->header_extra != NULL;
+	} else {
+		if (lzma_info_index_finish(coder->info))
+			return LZMA_DATA_ERROR;
+
+		coder->block_options.has_backward_size = true;
+		coder->block_options.handle_padding = false;
+		size_type = LZMA_INFO_FOOTER_METADATA;
+		want_extra = coder->footer_extra != NULL;
+	}
+
+	coder->block_options.has_uncompressed_size_in_footer = false;
+	coder->block_options.total_size = lzma_info_size_get(
+			coder->info, size_type);
+
+	coder->sequence = SEQ_METADATA_CODE;
+
+	return lzma_metadata_decoder_init(&coder->block_decoder, allocator,
+			&coder->block_options, &coder->metadata, want_extra);
+}
+
+
+static lzma_ret
+data_init(lzma_coder *coder, lzma_allocator *allocator)
+{
+	lzma_ret ret = lzma_info_iter_next(&coder->iter, allocator);
+	if (ret != LZMA_OK)
+		return ret;
+
+	ret = lzma_info_iter_set(&coder->iter, LZMA_VLI_VALUE_UNKNOWN,
+			coder->block_options.uncompressed_size);
+	if (ret != LZMA_OK)
+		return ret;
+
+	coder->block_options.total_size = coder->iter.total_size;
+	coder->block_options.uncompressed_size = coder->iter.uncompressed_size;
+	coder->block_options.total_limit = coder->total_left;
+	coder->block_options.uncompressed_limit = coder->uncompressed_left;
+
+	if (coder->header_flags.is_multi) {
+		coder->block_options.has_uncompressed_size_in_footer = false;
+		coder->block_options.has_backward_size = false;
+		coder->block_options.handle_padding = true;
+	} else {
+		coder->block_options.has_uncompressed_size_in_footer
+				= coder->iter.uncompressed_size
+					== LZMA_VLI_VALUE_UNKNOWN;
+		coder->block_options.has_backward_size = true;
+		coder->block_options.handle_padding = false;
+	}
+
+	coder->sequence = SEQ_DATA_CODE;
+
+	return lzma_block_decoder_init(&coder->block_decoder, allocator,
+			&coder->block_options);
+}
+
+
+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)
+{
+	while (*out_pos < out_size && (*in_pos < in_size
+			|| coder->sequence == SEQ_DATA_CODE))
+	switch (coder->sequence) {
+	case SEQ_STREAM_HEADER_CODE: {
+		const lzma_ret ret = coder->flags_decoder.code(
+				coder->flags_decoder.coder,
+				allocator, in, in_pos, in_size,
+				NULL, NULL, 0, LZMA_RUN);
+		if (ret != LZMA_STREAM_END)
+			return ret;
+
+		coder->sequence = SEQ_BLOCK_HEADER_INIT;
+
+		// Detect if the Check type is supported and give appropriate
+		// warning if it isn't. We don't warn every time a new Block
+		// is started.
+		lzma_check tmp;
+		if (lzma_check_init(&tmp, coder->header_flags.check))
+			return LZMA_UNSUPPORTED_CHECK;
+
+		break;
+	}
+
+	case SEQ_BLOCK_HEADER_INIT: {
+		coder->block_options.check = coder->header_flags.check;
+		coder->block_options.has_crc32 = coder->header_flags.has_crc32;
+
+		const lzma_ret ret = lzma_block_header_decoder_init(
+				&coder->block_header_decoder, allocator,
+				&coder->block_options);
+		if (ret != LZMA_OK)
+			return ret;
+
+		coder->sequence = SEQ_BLOCK_HEADER_CODE;
+	}
+
+	// Fall through
+
+	case SEQ_BLOCK_HEADER_CODE: {
+		lzma_ret ret = coder->block_header_decoder.code(
+				coder->block_header_decoder.coder,
+				allocator, in, in_pos, in_size,
+				NULL, NULL, 0, LZMA_RUN);
+
+		if (ret != LZMA_STREAM_END)
+			return ret;
+
+		if (coder->block_options.is_metadata)
+			ret = metadata_init(coder, allocator);
+		else
+			ret = data_init(coder, allocator);
+
+		if (ret != LZMA_OK)
+			return ret;
+
+		break;
+	}
+
+	case SEQ_METADATA_CODE: {
+		lzma_ret ret = coder->block_decoder.code(
+				coder->block_decoder.coder, allocator,
+				in, in_pos, in_size, NULL, NULL, 0, LZMA_RUN);
+		if (ret != LZMA_STREAM_END)
+			return ret;
+
+		const bool is_header_metadata = lzma_info_index_count_get(
+				coder->info) == 0;
+
+		if (is_header_metadata) {
+			if (coder->header_extra != NULL) {
+				*coder->header_extra = coder->metadata.extra;
+				coder->metadata.extra = NULL;
+			}
+
+			if (lzma_info_size_set(coder->info,
+					LZMA_INFO_HEADER_METADATA,
+					coder->block_options.total_size)
+					!= LZMA_OK)
+				return LZMA_PROG_ERROR;
+
+			coder->sequence = SEQ_BLOCK_HEADER_INIT;
+		} else {
+			if (coder->footer_extra != NULL) {
+				*coder->footer_extra = coder->metadata.extra;
+				coder->metadata.extra = NULL;
+			}
+
+			coder->sequence = SEQ_STREAM_TAIL_INIT;
+		}
+
+		assert(coder->metadata.extra == NULL);
+
+		ret = lzma_info_metadata_set(coder->info, allocator,
+				&coder->metadata, is_header_metadata, true);
+		if (ret != LZMA_OK)
+			return ret;
+
+		// Intialize coder->total_size and coder->uncompressed_size
+		// from Header Metadata.
+		if (is_header_metadata) {
+			coder->total_left = lzma_info_size_get(
+					coder->info, LZMA_INFO_TOTAL);
+			coder->uncompressed_left = lzma_info_size_get(
+					coder->info, LZMA_INFO_UNCOMPRESSED);
+		}
+
+		break;
+	}
+
+	case SEQ_DATA_CODE: {
+		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;
+
+		ret = lzma_info_iter_set(&coder->iter,
+				coder->block_options.total_size,
+				coder->block_options.uncompressed_size);
+		if (ret != LZMA_OK)
+			return ret;
+
+		// These won't overflow since lzma_info_iter_set() succeeded.
+		if (coder->total_left != LZMA_VLI_VALUE_UNKNOWN)
+			coder->total_left -= coder->block_options.total_size;
+		if (coder->uncompressed_left != LZMA_VLI_VALUE_UNKNOWN)
+			coder->uncompressed_left -= coder->block_options
+					.uncompressed_size;
+
+		if (!coder->header_flags.is_multi) {
+			ret = lzma_info_index_finish(coder->info);
+			if (ret != LZMA_OK)
+				return ret;
+
+			coder->sequence = SEQ_STREAM_TAIL_INIT;
+			break;
+		}
+
+		coder->sequence = SEQ_BLOCK_HEADER_INIT;
+		break;
+	}
+
+	case SEQ_STREAM_TAIL_INIT: {
+		lzma_ret ret = lzma_info_index_finish(coder->info);
+		if (ret != LZMA_OK)
+			return ret;
+
+		ret = lzma_stream_tail_decoder_init(&coder->flags_decoder,
+				allocator, &coder->tail_flags);
+		if (ret != LZMA_OK)
+			return ret;
+
+		coder->sequence = SEQ_STREAM_TAIL_CODE;
+	}
+
+	// Fall through
+
+	case SEQ_STREAM_TAIL_CODE: {
+		const lzma_ret ret = coder->flags_decoder.code(
+				coder->flags_decoder.coder, allocator,
+				in, in_pos, in_size, NULL, NULL, 0, LZMA_RUN);
+		if (ret != LZMA_STREAM_END)
+			return ret;
+
+		if (!lzma_stream_flags_is_equal(
+				coder->header_flags, coder->tail_flags))
+			return LZMA_DATA_ERROR;
+
+		return LZMA_STREAM_END;
+	}
+
+	default:
+		return LZMA_PROG_ERROR;
+	}
+
+	return LZMA_OK;
+}
+
+
+static void
+stream_decoder_end(lzma_coder *coder, lzma_allocator *allocator)
+{
+	lzma_next_coder_end(&coder->block_decoder, allocator);
+	lzma_next_coder_end(&coder->block_header_decoder, allocator);
+	lzma_next_coder_end(&coder->flags_decoder, allocator);
+	lzma_info_free(coder->info, allocator);
+	lzma_index_free(coder->metadata.index, allocator);
+	lzma_extra_free(coder->metadata.extra, allocator);
+	lzma_free(coder, allocator);
+	return;
+}
+
+
+static lzma_ret
+stream_decoder_init(lzma_next_coder *next, lzma_allocator *allocator,
+		lzma_extra **header, lzma_extra **footer)
+{
+	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->coder->block_decoder = LZMA_NEXT_CODER_INIT;
+		next->coder->block_header_decoder = LZMA_NEXT_CODER_INIT;
+		next->coder->info = NULL;
+		next->coder->flags_decoder = LZMA_NEXT_CODER_INIT;
+		next->coder->metadata.index = NULL;
+		next->coder->metadata.extra = NULL;
+	} else {
+		lzma_index_free(next->coder->metadata.index, allocator);
+		next->coder->metadata.index = NULL;
+
+		lzma_extra_free(next->coder->metadata.extra, allocator);
+		next->coder->metadata.extra = NULL;
+	}
+
+	next->coder->info = lzma_info_init(next->coder->info, allocator);
+	if (next->coder->info == NULL)
+		return LZMA_MEM_ERROR;
+
+	lzma_info_iter_begin(next->coder->info, &next->coder->iter);
+
+	// Initialize Stream Header decoder.
+	return_if_error(lzma_stream_header_decoder_init(
+				&next->coder->flags_decoder, allocator,
+				&next->coder->header_flags));
+
+	// Reset the *foo_extra pointers to NULL. This way the caller knows
+	// if there were no Extra Records. (We don't support appending
+	// Records to Extra list.)
+	if (header != NULL)
+		*header = NULL;
+	if (footer != NULL)
+		*footer = NULL;
+
+	// Reset some variables.
+	next->coder->sequence = SEQ_STREAM_HEADER_CODE;
+	next->coder->pos = 0;
+	next->coder->uncompressed_left = LZMA_VLI_VALUE_UNKNOWN;
+	next->coder->total_left = LZMA_VLI_VALUE_UNKNOWN;
+	next->coder->header_extra = header;
+	next->coder->footer_extra = footer;
+
+	return LZMA_OK;
+}
+
+
+extern lzma_ret
+lzma_stream_decoder_init(lzma_next_coder *next, lzma_allocator *allocator,
+		lzma_extra **header, lzma_extra **footer)
+{
+	lzma_next_coder_init(
+			stream_decoder_init, next, allocator, header, footer);
+}
+
+
+extern LZMA_API lzma_ret
+lzma_stream_decoder(lzma_stream *strm,
+		lzma_extra **header, lzma_extra **footer)
+{
+	lzma_next_strm_init(strm, stream_decoder_init, header, footer);
+
+	strm->internal->supported_actions[LZMA_RUN] = true;
+	strm->internal->supported_actions[LZMA_SYNC_FLUSH] = true;
+
+	return LZMA_OK;
+}