Imported to git.

1 files changed, 681 insertions, 0 deletions

diff --git a/src/liblzma/subblock/subblock_decoder.c b/src/liblzma/subblock/subblock_decoder.c
new file mode 100644
index 00000000..ef3c289f
--- /dev/null
+++ b/src/liblzma/subblock/subblock_decoder.c
@@ -0,0 +1,681 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       subblock_decoder.c
+/// \brief      Decoder of the Subblock filter
+//
+//  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 "subblock_decoder.h"
+#include "subblock_decoder_helper.h"
+#include "raw_decoder.h"
+
+
+/// Maximum number of consecutive Subblocks with Subblock Type Padding
+#define PADDING_MAX 31
+
+
+struct lzma_coder_s {
+	lzma_next_coder next;
+
+	enum {
+		SEQ_FLAGS,
+		SEQ_SIZE_1,
+		SEQ_SIZE_2,
+		SEQ_SIZE_3,
+		SEQ_DATA,
+		SEQ_REPEAT_COUNT_1,
+		SEQ_REPEAT_COUNT_2,
+		SEQ_REPEAT_COUNT_3,
+		SEQ_REPEAT_SIZE,
+		SEQ_REPEAT_READ_DATA,
+		SEQ_REPEAT_FAST,
+		SEQ_REPEAT_NORMAL,
+		SEQ_FILTER_FLAGS,
+		SEQ_FILTER_END,
+	} sequence;
+
+	/// Number of bytes left in the current Subblock Data field.
+	size_t size;
+
+	/// Uncompressed Size, or LZMA_VLI_VALUE_UNKNOWN if unknown.
+	lzma_vli uncompressed_size;
+
+	/// Number of consecutive Subblocks with Subblock Type Padding
+	uint32_t padding;
+
+	/// True when .next.code() has returned LZMA_STREAM_END.
+	bool next_finished;
+
+	/// True when the Subblock decoder has detected End of Payload Marker.
+	/// This may become true before next_finished becomes true.
+	bool this_finished;
+
+	/// True if Subfilters are allowed.
+	bool allow_subfilters;
+
+	/// Indicates if at least one byte of decoded output has been
+	/// produced after enabling Subfilter.
+	bool got_output_with_subfilter;
+
+	/// Possible subfilter
+	lzma_next_coder subfilter;
+
+	/// Filter Flags decoder is needed to parse the ID and Properties
+	/// of the subfilter.
+	lzma_next_coder filter_flags_decoder;
+
+	/// The filter_flags_decoder stores its results here.
+	lzma_options_filter filter_flags;
+
+	/// Options for the Subblock decoder helper. This is used to tell
+	/// the helper when it should return LZMA_STREAM_END to the subfilter.
+	lzma_options_subblock_helper helper;
+
+	struct {
+		/// How many times buffer should be repeated
+		size_t count;
+
+		/// Size of the buffer
+		size_t size;
+
+		/// Position in the buffer
+		size_t pos;
+
+		/// Buffer to hold the data to be repeated
+		uint8_t buffer[LZMA_SUBBLOCK_RLE_MAX];
+	} repeat;
+
+	/// Temporary buffer needed when the Subblock filter is not the last
+	/// filter in the chain. The output of the next filter is first
+	/// decoded into buffer[], which is then used as input for the actual
+	/// Subblock decoder.
+	struct {
+		size_t pos;
+		size_t size;
+		uint8_t buffer[LZMA_BUFFER_SIZE];
+	} temp;
+};
+
+
+/// Values of valid Subblock Flags
+enum {
+	FLAG_PADDING,
+	FLAG_EOPM,
+	FLAG_DATA,
+	FLAG_REPEAT,
+	FLAG_SET_SUBFILTER,
+	FLAG_END_SUBFILTER,
+};
+
+
+/// Substracts size from coder->uncompressed_size uncompressed size is known
+/// and size isn't bigger than coder->uncompressed_size.
+static inline bool
+update_uncompressed_size(lzma_coder *coder, size_t size)
+{
+	if (coder->uncompressed_size != LZMA_VLI_VALUE_UNKNOWN) {
+		if ((lzma_vli)(size) > coder->uncompressed_size)
+			return true;
+
+		coder->uncompressed_size -= size;
+	}
+
+	return false;
+}
+
+
+/// Calls the subfilter and updates coder->uncompressed_size.
+static lzma_ret
+subfilter_decode(lzma_coder *coder, lzma_allocator *allocator,
+		const uint8_t *in, size_t *in_pos,
+		size_t in_size, uint8_t *restrict out,
+		size_t *restrict out_pos, size_t out_size, lzma_action action)
+{
+	assert(coder->subfilter.code != NULL);
+
+	const size_t out_start = *out_pos;
+
+	// Call the subfilter.
+	const lzma_ret ret = coder->subfilter.code(
+			coder->subfilter.coder, allocator,
+			in, in_pos, in_size, out, out_pos, out_size, action);
+
+	// Update uncompressed_size.
+	if (update_uncompressed_size(coder, *out_pos - out_start))
+		return LZMA_DATA_ERROR;
+
+	return ret;
+}
+
+
+static lzma_ret
+decode_buffer(lzma_coder *coder, lzma_allocator *allocator,
+		const uint8_t *in, size_t *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))
+	switch (coder->sequence) {
+	case SEQ_FLAGS: {
+		if ((in[*in_pos] >> 4) != FLAG_PADDING)
+			coder->padding = 0;
+
+		// Do the correct action depending on the Subblock Type.
+		switch (in[*in_pos] >> 4) {
+		case FLAG_PADDING:
+			// Only check that reserved bits are zero.
+// 			if (++coder->padding > PADDING_MAX
+// 					|| in[*in_pos] & 0x0F)
+// 				return LZMA_DATA_ERROR;
+			++*in_pos;
+			break;
+
+		case FLAG_EOPM:
+			// Check that reserved bits are zero.
+			if (in[*in_pos] & 0x0F)
+				return LZMA_DATA_ERROR;
+
+			// There must be no Subfilter enabled.
+			if (coder->subfilter.code != NULL)
+				return LZMA_DATA_ERROR;
+
+			// End of Payload Marker must not be used if
+			// uncompressed size is known.
+			if (coder->uncompressed_size != LZMA_VLI_VALUE_UNKNOWN)
+				return LZMA_DATA_ERROR;
+
+			++*in_pos;
+			return LZMA_STREAM_END;
+
+		case FLAG_DATA:
+			// First four bits of the Subblock Data size.
+			coder->size = in[*in_pos] & 0x0F;
+			++*in_pos;
+			coder->got_output_with_subfilter = true;
+			coder->sequence = SEQ_SIZE_1;
+			break;
+
+		case FLAG_REPEAT:
+			// First four bits of the Repeat Count. We use
+			// coder->size as a temporary place for it.
+			coder->size = in[*in_pos] & 0x0F;
+			++*in_pos;
+			coder->got_output_with_subfilter = true;
+			coder->sequence = SEQ_REPEAT_COUNT_1;
+			break;
+
+		case FLAG_SET_SUBFILTER: {
+			if ((in[*in_pos] & 0x0F)
+					|| coder->subfilter.code != NULL
+					|| !coder->allow_subfilters)
+				return LZMA_DATA_ERROR;
+
+			assert(coder->filter_flags.options == NULL);
+			const lzma_ret ret = lzma_filter_flags_decoder_init(
+					&coder->filter_flags_decoder,
+					allocator, &coder->filter_flags);
+			if (ret != LZMA_OK)
+				return ret;
+
+			coder->got_output_with_subfilter = false;
+
+			++*in_pos;
+			coder->sequence = SEQ_FILTER_FLAGS;
+			break;
+		}
+
+		case FLAG_END_SUBFILTER:
+			if (coder->subfilter.code == NULL
+					|| !coder->got_output_with_subfilter)
+				return LZMA_DATA_ERROR;
+
+			// Tell the helper filter to indicate End of Input
+			// to our subfilter.
+			coder->helper.end_was_reached = true;
+
+			size_t dummy = 0;
+			const lzma_ret ret = subfilter_decode(coder, allocator,
+					NULL, &dummy, 0, out, out_pos,out_size,
+					action);
+
+			// If we didn't reach the end of the subfilter's output
+			// yet, return to the application. On the next call we
+			// will get to this same switch-case again, because we
+			// haven't updated *in_pos yet.
+			if (ret != LZMA_STREAM_END)
+				return ret;
+
+			// Free Subfilter's memory. This is a bit debatable,
+			// since we could avoid some malloc()/free() calls
+			// if the same Subfilter gets used soon again. But
+			// if Subfilter isn't used again, we could leave
+			// a memory-hogging filter dangling until someone
+			// frees Subblock filter itself.
+			lzma_next_coder_end(&coder->subfilter, allocator);
+
+			// Free memory used for subfilter options. This is
+			// safe, because we don't support any Subfilter that
+			// would allow pointers in the options structure.
+			lzma_free(coder->filter_flags.options, allocator);
+			coder->filter_flags.options = NULL;
+
+			++*in_pos;
+
+			if (coder->uncompressed_size == 0)
+				return LZMA_STREAM_END;
+
+			break;
+
+		default:
+			return LZMA_DATA_ERROR;
+		}
+
+		break;
+	}
+
+	case SEQ_SIZE_1:
+	case SEQ_REPEAT_COUNT_1:
+		// We use the same code to parse
+		//  - the Size (28 bits) in Subblocks of type Data; and
+		//  - the Repeat count (28 bits) in Subblocks of type
+		//    Repeating Data.
+		coder->size |= (size_t)(in[*in_pos]) << 4;
+		++*in_pos;
+		++coder->sequence;
+		break;
+
+	case SEQ_SIZE_2:
+	case SEQ_REPEAT_COUNT_2:
+		coder->size |= (size_t)(in[*in_pos]) << 12;
+		++*in_pos;
+		++coder->sequence;
+		break;
+
+	case SEQ_SIZE_3:
+	case SEQ_REPEAT_COUNT_3:
+		coder->size |= (size_t)(in[*in_pos]) << 20;
+
+		// The real value is the stored value plus one.
+		++coder->size;
+
+		++*in_pos;
+		++coder->sequence;
+		break;
+
+	case SEQ_REPEAT_SIZE:
+		// Move the Repeat Count to the correct variable and parse
+		// the Size of the Data to be repeated.
+		coder->repeat.count = coder->size;
+		coder->repeat.size = (size_t)(in[*in_pos]) + 1;
+		coder->repeat.pos = 0;
+		++*in_pos;
+		coder->sequence = SEQ_REPEAT_READ_DATA;
+		break;
+
+	case SEQ_REPEAT_READ_DATA: {
+		// Fill coder->repeat.buffer[].
+		const size_t in_avail = in_size - *in_pos;
+		const size_t out_avail
+				= coder->repeat.size - coder->repeat.pos;
+		const size_t copy_size = MIN(in_avail, out_avail);
+
+		memcpy(coder->repeat.buffer + coder->repeat.pos,
+				in + *in_pos, copy_size);
+		*in_pos += copy_size;
+		coder->repeat.pos += copy_size;
+
+		if (coder->repeat.pos == coder->repeat.size) {
+			coder->repeat.pos = 0;
+
+			if (coder->repeat.size == 1
+					&& coder->subfilter.code == NULL)
+				coder->sequence = SEQ_REPEAT_FAST;
+			else
+				coder->sequence = SEQ_REPEAT_NORMAL;
+		}
+
+		break;
+	}
+
+	case SEQ_REPEAT_FAST: {
+		// Optimization for cases when there is only one byte to
+		// repeat and no Subfilter.
+		const size_t out_avail = out_size - *out_pos;
+		const size_t copy_size = MIN(coder->repeat.count, out_avail);
+
+		memset(out + *out_pos, coder->repeat.buffer[0], copy_size);
+
+		*out_pos += copy_size;
+		coder->repeat.count -= copy_size;
+
+		if (update_uncompressed_size(coder, copy_size))
+			return LZMA_DATA_ERROR;
+
+		if (coder->repeat.count == 0) {
+			if (coder->uncompressed_size == 0)
+				return LZMA_STREAM_END;
+		} else {
+			return LZMA_OK;
+		}
+
+		coder->sequence = SEQ_FLAGS;
+		break;
+	}
+
+	case SEQ_REPEAT_NORMAL:
+		do {
+			// Cycle the repeat buffer if needed.
+			if (coder->repeat.pos == coder->repeat.size) {
+				if (--coder->repeat.count == 0) {
+					coder->sequence = SEQ_FLAGS;
+					break;
+				}
+
+				coder->repeat.pos = 0;
+			}
+
+			if (coder->subfilter.code == NULL) {
+				const size_t copy_size = bufcpy(
+						coder->repeat.buffer,
+						&coder->repeat.pos,
+						coder->repeat.size,
+						out, out_pos, out_size);
+
+				if (update_uncompressed_size(coder, copy_size))
+					return LZMA_DATA_ERROR;
+
+			} else {
+				const lzma_ret ret = subfilter_decode(
+						coder, allocator,
+						coder->repeat.buffer,
+						&coder->repeat.pos,
+						coder->repeat.size,
+						out, out_pos, out_size,
+						action);
+
+				if (ret == LZMA_STREAM_END) {
+					// End of Subfilter can occur only at
+					// a Subblock boundary.
+					if (coder->repeat.pos
+							!= coder->repeat.size
+							|| --coder->repeat
+								.count != 0)
+						return LZMA_DATA_ERROR;
+
+					// We need a Subblock with Unset
+					// Subfilter before more data.
+					coder->sequence = SEQ_FILTER_END;
+					break;
+
+				} else if (ret != LZMA_OK) {
+					return ret;
+				}
+			}
+		} while (*out_pos < out_size);
+
+		break;
+
+	case SEQ_DATA: {
+		// Limit the amount of input to match the available
+		// Subblock Data size.
+		size_t in_limit;
+		if (in_size - *in_pos > coder->size)
+			in_limit = *in_pos + coder->size;
+		else
+			in_limit = in_size;
+
+		if (coder->subfilter.code == NULL) {
+			const size_t copy_size = bufcpy(
+					in, in_pos, in_limit,
+					out, out_pos, out_size);
+
+			coder->size -= copy_size;
+
+			if (update_uncompressed_size(coder, copy_size))
+				return LZMA_DATA_ERROR;
+
+		} else {
+			const size_t in_start = *in_pos;
+			const lzma_ret ret = subfilter_decode(
+					coder, allocator,
+					in, in_pos, in_limit,
+					out, out_pos, out_size,
+					action);
+
+			// Update the number of unprocessed bytes left in
+			// this Subblock. This assert() is true because
+			// in_limit prevents *in_pos getting too big.
+			assert(*in_pos - in_start <= coder->size);
+			coder->size -= *in_pos - in_start;
+
+			if (ret == LZMA_STREAM_END) {
+				// End of Subfilter can occur only at
+				// a Subblock boundary.
+				if (coder->size != 0)
+					return LZMA_DATA_ERROR;
+
+				// We need a Subblock with Unset
+				// Subfilter before more data.
+				coder->sequence = SEQ_FILTER_END;
+				break;
+			}
+
+			if (ret != LZMA_OK)
+				return ret;
+		}
+
+		// If we couldn't process the whole Subblock Data yet, return.
+		if (coder->size > 0)
+			return LZMA_OK;
+
+		// Check if we have decoded all the data.
+		if (coder->uncompressed_size == 0
+				&& coder->subfilter.code == NULL)
+			return LZMA_STREAM_END;
+
+		coder->sequence = SEQ_FLAGS;
+		break;
+	}
+
+	case SEQ_FILTER_FLAGS: {
+		lzma_ret ret = coder->filter_flags_decoder.code(
+				coder->filter_flags_decoder.coder, allocator,
+				in, in_pos, in_size, NULL, NULL, 0, LZMA_RUN);
+		if (ret != LZMA_STREAM_END)
+			return ret == LZMA_HEADER_ERROR
+					? LZMA_DATA_ERROR : ret;
+
+		// Don't free the filter_flags_decoder. It doesn't take much
+		// memory and we may need it again.
+
+		// Initialize the Subfilter. Subblock and Copy filters are
+		// not allowed.
+		if (coder->filter_flags.id == LZMA_FILTER_COPY
+				|| coder->filter_flags.id
+					== LZMA_FILTER_SUBBLOCK)
+			return LZMA_DATA_ERROR;
+
+		coder->helper.end_was_reached = false;
+
+		lzma_options_filter filters[3] = {
+			{
+				.id = coder->filter_flags.id,
+				.options = coder->filter_flags.options,
+			}, {
+				.id = LZMA_FILTER_SUBBLOCK_HELPER,
+				.options = &coder->helper,
+			}, {
+				.id = LZMA_VLI_VALUE_UNKNOWN,
+				.options = NULL,
+			}
+		};
+
+		// Optimization: We know that LZMA uses End of Payload Marker
+		// (not End of Input), so we can omit the helper filter.
+		if (filters[0].id == LZMA_FILTER_LZMA)
+			filters[1].id = LZMA_VLI_VALUE_UNKNOWN;
+
+		ret = lzma_raw_decoder_init(&coder->subfilter, allocator,
+				filters, LZMA_VLI_VALUE_UNKNOWN, false);
+		if (ret != LZMA_OK)
+			return ret;
+
+		coder->sequence = SEQ_FLAGS;
+		break;
+	}
+
+	case SEQ_FILTER_END:
+		// We are in the beginning of a Subblock. The next Subblock
+		// whose type is not Padding, must indicate end of Subfilter.
+		if (in[*in_pos] == (FLAG_PADDING << 4)) {
+			++*in_pos;
+			break;
+		}
+
+		if (in[*in_pos] != (FLAG_END_SUBFILTER << 4))
+			return LZMA_DATA_ERROR;
+
+		coder->sequence = SEQ_FLAGS;
+		break;
+
+	default:
+		return LZMA_PROG_ERROR;
+	}
+
+	return LZMA_OK;
+}
+
+
+static lzma_ret
+subblock_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)
+{
+	if (coder->next.code == NULL)
+		return decode_buffer(coder, allocator, in, in_pos, in_size,
+				out, out_pos, out_size, action);
+
+	while (*out_pos < out_size) {
+		if (!coder->next_finished
+				&& coder->temp.pos == coder->temp.size) {
+			coder->temp.pos = 0;
+			coder->temp.size = 0;
+
+			const lzma_ret ret = coder->next.code(
+					coder->next.coder,
+					allocator, in, in_pos, in_size,
+					coder->temp.buffer, &coder->temp.size,
+					LZMA_BUFFER_SIZE, action);
+
+			if (ret == LZMA_STREAM_END)
+				coder->next_finished = true;
+			else if (coder->temp.size == 0 || ret != LZMA_OK)
+				return ret;
+		}
+
+		if (coder->this_finished) {
+			if (coder->temp.pos != coder->temp.size)
+				return LZMA_DATA_ERROR;
+
+			if (coder->next_finished)
+				return LZMA_STREAM_END;
+
+			return LZMA_OK;
+		}
+
+		const lzma_ret ret = decode_buffer(coder, allocator,
+				coder->temp.buffer, &coder->temp.pos,
+				coder->temp.size,
+				out, out_pos, out_size, action);
+
+		if (ret == LZMA_STREAM_END)
+			// The next coder in the chain hasn't finished
+			// yet. If the input data is valid, there
+			// must be no more output coming, but the
+			// next coder may still need a litle more
+			// input to detect End of Payload Marker.
+			coder->this_finished = true;
+		else if (ret != LZMA_OK)
+			return ret;
+		else if (coder->next_finished && *out_pos < out_size)
+			return LZMA_DATA_ERROR;
+	}
+
+	return LZMA_OK;
+}
+
+
+static void
+subblock_decoder_end(lzma_coder *coder, lzma_allocator *allocator)
+{
+	lzma_next_coder_end(&coder->next, allocator);
+	lzma_next_coder_end(&coder->subfilter, allocator);
+	lzma_next_coder_end(&coder->filter_flags_decoder, allocator);
+	lzma_free(coder->filter_flags.options, allocator);
+	lzma_free(coder, allocator);
+	return;
+}
+
+
+extern lzma_ret
+lzma_subblock_decoder_init(lzma_next_coder *next, lzma_allocator *allocator,
+		const lzma_filter_info *filters)
+{
+	if (next->coder == NULL) {
+		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
+		if (next->coder == NULL)
+			return LZMA_MEM_ERROR;
+
+		next->coder->next = LZMA_NEXT_CODER_INIT;
+		next->coder->subfilter = LZMA_NEXT_CODER_INIT;
+		next->coder->filter_flags_decoder = LZMA_NEXT_CODER_INIT;
+
+	} else {
+		lzma_next_coder_end(&next->coder->subfilter, allocator);
+		lzma_free(next->coder->filter_flags.options, allocator);
+	}
+
+	next->coder->filter_flags.options = NULL;
+
+	next->coder->sequence = SEQ_FLAGS;
+	next->coder->uncompressed_size = filters[0].uncompressed_size;
+	next->coder->padding = 0;
+	next->coder->next_finished = false;
+	next->coder->this_finished = false;
+	next->coder->temp.pos = 0;
+	next->coder->temp.size = 0;
+
+	if (filters[0].options != NULL)
+		next->coder->allow_subfilters = ((lzma_options_subblock *)(
+				filters[0].options))->allow_subfilters;
+	else
+		next->coder->allow_subfilters = false;
+
+	{
+		const lzma_ret ret = lzma_next_filter_init(&next->coder->next,
+				allocator, filters + 1);
+		if (ret != LZMA_OK) {
+			subblock_decoder_end(next->coder, allocator);
+			return ret;
+		}
+	}
+
+	next->code = &subblock_decode;
+	next->end = &subblock_decoder_end;
+
+	return LZMA_OK;
+}