diff options
Diffstat (limited to '')
| -rw-r--r-- | src/liblzma/common/stream_decoder.c | 57 |
1 files changed, 32 insertions, 25 deletions
diff --git a/src/liblzma/common/stream_decoder.c b/src/liblzma/common/stream_decoder.c index 5b46819d..cf7af7ac 100644 --- a/src/liblzma/common/stream_decoder.c +++ b/src/liblzma/common/stream_decoder.c @@ -66,9 +66,9 @@ struct lzma_coder_s { /// 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. FIXME + /// 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 @@ -152,10 +152,10 @@ stream_decode(lzma_coder *coder, lzma_allocator *allocator, if (coder->tell_check) return LZMA_SEE_CHECK; - - break; } + // Fall through + case SEQ_BLOCK_HEADER: { if (*in_pos >= in_size) return LZMA_OK; @@ -225,9 +225,10 @@ stream_decode(lzma_coder *coder, lzma_allocator *allocator, return ret; coder->sequence = SEQ_BLOCK; - break; } + // Fall through + case SEQ_BLOCK: { const lzma_ret ret = coder->block_decoder.code( coder->block_decoder.coder, allocator, @@ -263,9 +264,10 @@ stream_decode(lzma_coder *coder, lzma_allocator *allocator, return ret; coder->sequence = SEQ_STREAM_FOOTER; - break; } + // 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, @@ -277,11 +279,15 @@ stream_decode(lzma_coder *coder, lzma_allocator *allocator, coder->pos = 0; - // Decode the Stream Footer. - // FIXME LZMA_FORMAT_ERROR doesn't make sense here. + // 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; - return_if_error(lzma_stream_footer_decode( - &footer_flags, coder->buffer)); + 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. @@ -299,11 +305,13 @@ stream_decode(lzma_coder *coder, lzma_allocator *allocator, return LZMA_STREAM_END; coder->sequence = SEQ_STREAM_PADDING; - break; + + // 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 @@ -318,24 +326,24 @@ stream_decode(lzma_coder *coder, lzma_allocator *allocator, : LZMA_DATA_ERROR; } - if (in[*in_pos] != 0x00) { - if (coder->pos != 0) { - // Stream Padding is not a multiple of - // four bytes. - ++*in_pos; - return LZMA_DATA_ERROR; - } - - // Prepare to decode the next Stream. - return_if_error(stream_decoder_reset( - coder, allocator)); + // 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: @@ -404,7 +412,6 @@ 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_SYNC_FLUSH] = true; // FIXME strm->internal->supported_actions[LZMA_FINISH] = true; return LZMA_OK; |