Cleaned up Block encoder and moved the no longer shared

code from block_private.h to block_decoder.c. Now the Block
encoder doesn't need compressed_size and uncompressed_size
from lzma_block structure to be initialized.

4 files changed, 66 insertions, 97 deletions

diff --git a/src/liblzma/common/Makefile.am b/src/liblzma/common/Makefile.am
index 3ec2e270..ca38afc2 100644
--- a/src/liblzma/common/Makefile.am
+++ b/src/liblzma/common/Makefile.am
@@ -28,7 +28,6 @@ libcommon_la_SOURCES = \
 	common.h \
 	bsr.h \
 	block_util.c \
-	block_private.h \
 	filter_common.c \
 	filter_common.h \
 	index.c \
diff --git a/src/liblzma/common/block_decoder.c b/src/liblzma/common/block_decoder.c
index eab25a88..9eb33651 100644
--- a/src/liblzma/common/block_decoder.c
+++ b/src/liblzma/common/block_decoder.c
@@ -18,7 +18,6 @@
 ///////////////////////////////////////////////////////////////////////////////
 
 #include "block_decoder.h"
-#include "block_private.h"
 #include "filter_decoder.h"
 #include "check.h"
 
@@ -56,6 +55,28 @@ struct lzma_coder_s {
 };
 
 
+static inline bool
+update_size(lzma_vli *size, lzma_vli add, lzma_vli limit)
+{
+	if (limit > LZMA_VLI_VALUE_MAX)
+		limit = LZMA_VLI_VALUE_MAX;
+
+	if (limit < *size || limit - *size < add)
+		return true;
+
+	*size += add;
+
+	return false;
+}
+
+
+static inline bool
+is_size_valid(lzma_vli size, lzma_vli reference)
+{
+	return reference == LZMA_VLI_VALUE_UNKNOWN || reference == size;
+}
+
+
 static lzma_ret
 block_decode(lzma_coder *coder, lzma_allocator *allocator,
 		const uint8_t *restrict in, size_t *restrict in_pos,
diff --git a/src/liblzma/common/block_encoder.c b/src/liblzma/common/block_encoder.c
index 5aa3626b..ee75033a 100644
--- a/src/liblzma/common/block_encoder.c
+++ b/src/liblzma/common/block_encoder.c
@@ -18,11 +18,25 @@
 ///////////////////////////////////////////////////////////////////////////////
 
 #include "block_encoder.h"
-#include "block_private.h"
 #include "filter_encoder.h"
 #include "check.h"
 
 
+/// The maximum size of a single Block is limited by the maximum size of
+/// a Stream, which is 2^63 - 1 bytes (i.e. LZMA_VLI_VALUE_MAX). We could
+/// take into account the headers etc. to determine the exact maximum size
+/// of the Compressed Data field, but the complexity would give us nothing
+/// useful. Instead, limit the size of Compressed Data so that even with
+/// biggest possible Block Header and Check fields the total size of the
+/// Block stays as valid VLI. This way we don't produce incorrect output
+/// if someone will really try creating a Block of 8 EiB.
+///
+/// ~LZMA_VLI_C(3) is to guarantee that if we need padding at the end of
+/// the Compressed Data field, it will still stay in the proper limit.
+#define COMPRESSED_SIZE_MAX ((LZMA_VLI_VALUE_MAX - LZMA_BLOCK_HEADER_SIZE_MAX \
+		- LZMA_CHECK_SIZE_MAX) & ~LZMA_VLI_C(3))
+
+
 struct lzma_coder_s {
 	/// The filters in the chain; initialized with lzma_raw_decoder_init().
 	lzma_next_coder next;
@@ -59,26 +73,9 @@ block_encode(lzma_coder *coder, lzma_allocator *allocator,
 		size_t *restrict out_pos, size_t out_size, lzma_action action)
 {
 	// Check that our amount of input stays in proper limits.
-	if (coder->options->uncompressed_size != LZMA_VLI_VALUE_UNKNOWN) {
-		if (action == LZMA_FINISH) {
-			if (coder->options->uncompressed_size
-					- coder->uncompressed_size
-					!= (lzma_vli)(in_size - *in_pos))
-				return LZMA_PROG_ERROR;
-		} else {
-			if (coder->options->uncompressed_size
-					- coder->uncompressed_size
-					<  (lzma_vli)(in_size - *in_pos))
-				return LZMA_PROG_ERROR;
-		}
-	} else if (LZMA_VLI_VALUE_MAX - coder->uncompressed_size
-			< (lzma_vli)(in_size - *in_pos)) {
+	if (LZMA_VLI_VALUE_MAX - coder->uncompressed_size < in_size - *in_pos)
 		return LZMA_PROG_ERROR;
-	}
 
-	// Main loop
-	while (*out_pos < out_size
-			&& (*in_pos < in_size || action != LZMA_RUN))
 	switch (coder->sequence) {
 	case SEQ_CODE: {
 		const size_t in_start = *in_pos;
@@ -91,12 +88,11 @@ block_encode(lzma_coder *coder, lzma_allocator *allocator,
 		const size_t in_used = *in_pos - in_start;
 		const size_t out_used = *out_pos - out_start;
 
-		// FIXME We must also check that Total Size doesn't get
-		// too big.
-		if (update_size(&coder->compressed_size, out_used,
-				coder->options->compressed_size))
+		if (COMPRESSED_SIZE_MAX - coder->compressed_size < out_used)
 			return LZMA_DATA_ERROR;
 
+		coder->compressed_size += out_used;
+
 		// No need to check for overflow because we have already
 		// checked it at the beginning of this function.
 		coder->uncompressed_size += in_used;
@@ -108,31 +104,28 @@ block_encode(lzma_coder *coder, lzma_allocator *allocator,
 			return ret;
 
 		assert(*in_pos == in_size);
+		assert(action == LZMA_FINISH);
+
 		coder->sequence = SEQ_PADDING;
-		break;
 	}
 
+	// Fall through
+
 	case SEQ_PADDING:
 		// Pad Compressed Data to a multiple of four bytes.
-		if (coder->compressed_size & 3) {
+		while (coder->compressed_size & 3) {
+			if (*out_pos >= out_size)
+				return LZMA_OK;
+
 			out[*out_pos] = 0x00;
 			++*out_pos;
 
-			if (update_size(&coder->compressed_size, 1,
-					coder->options->compressed_size))
-				return LZMA_DATA_ERROR;
-
-			break;
+			// No need to use check for overflow here since we
+			// have already checked in SEQ_CODE that Compressed
+			// Size will stay in proper limits.
+			++coder->compressed_size;
 		}
 
-		// Compressed and Uncompressed Sizes are now at their final
-		// values. Verify that they match the values given to us.
-		if (!is_size_valid(coder->compressed_size,
-					coder->options->compressed_size)
-				|| !is_size_valid(coder->uncompressed_size,
-					coder->options->uncompressed_size))
-			return LZMA_DATA_ERROR;
-
 		// Copy the values into coder->options. The caller
 		// may use this information to construct Index.
 		coder->options->compressed_size = coder->compressed_size;
@@ -146,21 +139,24 @@ block_encode(lzma_coder *coder, lzma_allocator *allocator,
 
 	// Fall through
 
-	case SEQ_CHECK:
-		out[*out_pos] = coder->check.buffer.u8[coder->check_pos];
-		++*out_pos;
+	case SEQ_CHECK: {
+		const uint32_t check_size
+				= lzma_check_size(coder->options->check);
 
-		if (++coder->check_pos
-				== lzma_check_size(coder->options->check))
-			return LZMA_STREAM_END;
+		while (*out_pos < out_size) {
+			out[*out_pos] = coder->check.buffer.u8[
+					coder->check_pos];
+			++*out_pos;
 
-		break;
+			if (++coder->check_pos == check_size)
+				return LZMA_STREAM_END;
+		}
 
-	default:
-		return LZMA_PROG_ERROR;
+		return LZMA_OK;
+	}
 	}
 
-	return LZMA_OK;
+	return LZMA_PROG_ERROR;
 }
 
 
diff --git a/src/liblzma/common/block_private.h b/src/liblzma/common/block_private.h
deleted file mode 100644
index 235e96b8..00000000
--- a/src/liblzma/common/block_private.h
+++ /dev/null
@@ -1,47 +0,0 @@
-///////////////////////////////////////////////////////////////////////////////
-//
-/// \file       block_private.h
-/// \brief      Common stuff for Block encoder and decoder
-//
-//  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.
-//
-///////////////////////////////////////////////////////////////////////////////
-
-#ifndef LZMA_BLOCK_COMMON_H
-#define LZMA_BLOCK_COMMON_H
-
-#include "common.h"
-
-
-static inline bool
-update_size(lzma_vli *size, lzma_vli add, lzma_vli limit)
-{
-	if (limit > LZMA_VLI_VALUE_MAX)
-		limit = LZMA_VLI_VALUE_MAX;
-
-	if (limit < *size || limit - *size < add)
-		return true;
-
-	*size += add;
-
-	return false;
-}
-
-
-static inline bool
-is_size_valid(lzma_vli size, lzma_vli reference)
-{
-	return reference == LZMA_VLI_VALUE_UNKNOWN || reference == size;
-}
-
-#endif