1 files changed, 88 insertions, 0 deletions
diff --git a/src/liblzma/common/filter_buffer_decoder.c b/src/liblzma/common/filter_buffer_decoder.c
new file mode 100644
index 0000000..6620986
--- /dev/null
+++ b/src/liblzma/common/filter_buffer_decoder.c
@@ -0,0 +1,88 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       filter_buffer_decoder.c
+/// \brief      Single-call raw decoding
+//
+//  Author:     Lasse Collin
+//
+//  This file has been put into the public domain.
+//  You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "filter_decoder.h"
+
+
+extern LZMA_API(lzma_ret)
+lzma_raw_buffer_decode(
+		const lzma_filter *filters, const lzma_allocator *allocator,
+		const uint8_t *in, size_t *in_pos, size_t in_size,
+		uint8_t *out, size_t *out_pos, size_t out_size)
+{
+	// Validate what isn't validated later in filter_common.c.
+	if (in == NULL || in_pos == NULL || *in_pos > in_size || out == NULL
+			|| out_pos == NULL || *out_pos > out_size)
+		return LZMA_PROG_ERROR;
+
+	// Initialize the decoer.
+	lzma_next_coder next = LZMA_NEXT_CODER_INIT;
+	return_if_error(lzma_raw_decoder_init(&next, allocator, filters));
+
+	// Store the positions so that we can restore them if something
+	// goes wrong.
+	const size_t in_start = *in_pos;
+	const size_t out_start = *out_pos;
+
+	// Do the actual decoding and free decoder's memory.
+	lzma_ret ret = next.code(next.coder, allocator, in, in_pos, in_size,
+			out, out_pos, out_size, LZMA_FINISH);
+
+	if (ret == LZMA_STREAM_END) {
+		ret = LZMA_OK;
+	} else {
+		if (ret == LZMA_OK) {
+			// Either the input was truncated or the
+			// output buffer was too small.
+			assert(*in_pos == in_size || *out_pos == out_size);
+
+			if (*in_pos != in_size) {
+				// Since input wasn't consumed completely,
+				// the output buffer became full and is
+				// too small.
+				ret = LZMA_BUF_ERROR;
+
+			} else if (*out_pos != out_size) {
+				// Since output didn't became full, the input
+				// has to be truncated.
+				ret = LZMA_DATA_ERROR;
+
+			} else {
+				// All the input was consumed and output
+				// buffer is full. Now we don't immediately
+				// know the reason for the error. Try
+				// decoding one more byte. If it succeeds,
+				// then the output buffer was too small. If
+				// we cannot get a new output byte, the input
+				// is truncated.
+				uint8_t tmp[1];
+				size_t tmp_pos = 0;
+				(void)next.code(next.coder, allocator,
+						in, in_pos, in_size,
+						tmp, &tmp_pos, 1, LZMA_FINISH);
+
+				if (tmp_pos == 1)
+					ret = LZMA_BUF_ERROR;
+				else
+					ret = LZMA_DATA_ERROR;
+			}
+		}
+
+		// Restore the positions.
+		*in_pos = in_start;
+		*out_pos = out_start;
+	}
+
+	lzma_next_end(&next, allocator);
+
+	return ret;
+}