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author | Lasse Collin <lasse.collin@tukaani.org> | 2008-08-28 22:53:15 +0300 |
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committer | Lasse Collin <lasse.collin@tukaani.org> | 2008-08-28 22:53:15 +0300 |
commit | 3b34851de1eaf358cf9268922fa0eeed8278d680 (patch) | |
tree | 7bab212af647541df64227a8d350d17a2e789f6b /src/liblzma/common/stream_decoder.c | |
parent | Fix test_filter_flags to match the new restriction of lc+lp. (diff) | |
download | xz-3b34851de1eaf358cf9268922fa0eeed8278d680.tar.xz |
Sort of garbage collection commit. :-| Many things are still
broken. API has changed a lot and it will still change a
little more here and there. The command line tool doesn't
have all the required changes to reflect the API changes, so
it's easy to get "internal error" or trigger assertions.
Diffstat (limited to 'src/liblzma/common/stream_decoder.c')
-rw-r--r-- | src/liblzma/common/stream_decoder.c | 238 |
1 files changed, 181 insertions, 57 deletions
diff --git a/src/liblzma/common/stream_decoder.c b/src/liblzma/common/stream_decoder.c index 1bf7f1f8..5b46819d 100644 --- a/src/liblzma/common/stream_decoder.c +++ b/src/liblzma/common/stream_decoder.c @@ -17,8 +17,8 @@ // /////////////////////////////////////////////////////////////////////////////// -#include "stream_common.h" #include "stream_decoder.h" +#include "stream_flags_common.h" #include "check.h" #include "stream_flags_decoder.h" #include "block_decoder.h" @@ -31,6 +31,7 @@ struct lzma_coder_s { SEQ_BLOCK, SEQ_INDEX, SEQ_STREAM_FOOTER, + SEQ_STREAM_PADDING, } sequence; /// Block or Metadata decoder. This takes little memory and the same @@ -40,7 +41,7 @@ struct lzma_coder_s { /// Block options decoded by the Block Header decoder and used by /// the Block decoder. - lzma_options_block block_options; + lzma_block block_options; /// Stream Flags from Stream Header lzma_stream_flags stream_flags; @@ -49,8 +50,35 @@ struct lzma_coder_s { /// with O(1) memory usage. lzma_index_hash *index_hash; - /// Write position in buffer[] - size_t buffer_pos; + /// Memory usage limit + uint64_t memlimit; + + /// If true, LZMA_NO_CHECK is returned if the Stream has + /// no integrity check. + bool warn_no_check; + + /// If true, LZMA_UNSUPPORTED_CHECK is returned if the Stream has + /// an integrity check that isn't supported by this liblzma build. + bool warn_unsupported_check; + + /// If true, LZMA_SEE_CHECK is returned after decoding Stream Header. + bool tell_check; + + /// 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 + bool concatenated; + + /// When decoding concatenated Streams, this is true as long as we + /// are decoding the first Stream. This is needed to avoid misleading + /// LZMA_FORMAT_ERROR in case the later Streams don't have valid magic + /// bytes. + bool first_stream; + + /// Write position in buffer[] and position in Stream Padding + size_t pos; /// Buffer to hold Stream Header, Block Header, and Stream Footer. /// Block Header has biggest maximum size. @@ -59,6 +87,23 @@ struct lzma_coder_s { static lzma_ret +stream_decoder_reset(lzma_coder *coder, lzma_allocator *allocator) +{ + // Initialize the Index hash used to verify the Index. + coder->index_hash = lzma_index_hash_init(coder->index_hash, allocator); + if (coder->index_hash == NULL) + return LZMA_MEM_ERROR; + + // Reset the rest of the variables. + coder->sequence = SEQ_STREAM_HEADER; + coder->block_options.filters = NULL; + coder->pos = 0; + + return LZMA_OK; +} + + +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, @@ -66,43 +111,56 @@ stream_decode(lzma_coder *coder, lzma_allocator *allocator, { // When decoding the actual Block, it may be able to produce more // output even if we don't give it any new input. - while (*out_pos < out_size && (*in_pos < in_size - || coder->sequence == SEQ_BLOCK)) + while (true) switch (coder->sequence) { case SEQ_STREAM_HEADER: { // Copy the Stream Header to the internal buffer. - bufcpy(in, in_pos, in_size, coder->buffer, &coder->buffer_pos, + lzma_bufcpy(in, in_pos, in_size, coder->buffer, &coder->pos, LZMA_STREAM_HEADER_SIZE); // Return if we didn't get the whole Stream Header yet. - if (coder->buffer_pos < LZMA_STREAM_HEADER_SIZE) + if (coder->pos < LZMA_STREAM_HEADER_SIZE) return LZMA_OK; - coder->buffer_pos = 0; + coder->pos = 0; // Decode the Stream Header. - return_if_error(lzma_stream_header_decode( - &coder->stream_flags, coder->buffer)); + const lzma_ret ret = lzma_stream_header_decode( + &coder->stream_flags, coder->buffer); + if (ret != LZMA_OK) + return ret == LZMA_FORMAT_ERROR && !coder->first_stream + ? LZMA_DATA_ERROR : ret; // Copy the type of the Check so that Block Header and Block // decoders see it. coder->block_options.check = coder->stream_flags.check; - // Even if we return LZMA_UNSUPPORTED_CHECK below, we want + // Even if we return LZMA_*_CHECK below, we want // to continue from Block Header decoding. coder->sequence = SEQ_BLOCK_HEADER; - // 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. - if (!lzma_available_checks[coder->block_options.check]) + // Detect if there's no integrity check or if it is + // unsupported if those were requested by the application. + if (coder->warn_no_check && coder->stream_flags.check + == LZMA_CHECK_NONE) + return LZMA_NO_CHECK; + + if (coder->warn_unsupported_check + && !lzma_check_is_supported( + coder->stream_flags.check)) return LZMA_UNSUPPORTED_CHECK; + if (coder->tell_check) + return LZMA_SEE_CHECK; + break; } case SEQ_BLOCK_HEADER: { - if (coder->buffer_pos == 0) { + if (*in_pos >= in_size) + return LZMA_OK; + + if (coder->pos == 0) { // Detect if it's Index. if (in[*in_pos] == 0x00) { coder->sequence = SEQ_INDEX; @@ -118,29 +176,41 @@ stream_decode(lzma_coder *coder, lzma_allocator *allocator, } // Copy the Block Header to the internal buffer. - bufcpy(in, in_pos, in_size, coder->buffer, &coder->buffer_pos, + lzma_bufcpy(in, in_pos, in_size, coder->buffer, &coder->pos, coder->block_options.header_size); // Return if we didn't get the whole Block Header yet. - if (coder->buffer_pos < coder->block_options.header_size) + if (coder->pos < coder->block_options.header_size) return LZMA_OK; - coder->buffer_pos = 0; + coder->pos = 0; // Set up a buffer to hold the filter chain. Block Header // decoder will initialize all members of this array so // we don't need to do it here. - lzma_options_filter filters[LZMA_BLOCK_FILTERS_MAX + 1]; + lzma_filter filters[LZMA_BLOCK_FILTERS_MAX + 1]; coder->block_options.filters = filters; // Decode the Block Header. return_if_error(lzma_block_header_decode(&coder->block_options, allocator, coder->buffer)); - // Initialize the Block decoder. - const lzma_ret ret = lzma_block_decoder_init( - &coder->block_decoder, - allocator, &coder->block_options); + // Check the memory usage limit. + const uint64_t memusage = lzma_memusage_decoder(filters); + lzma_ret ret; + + if (memusage == UINT64_MAX) { + // One or more unknown Filter IDs. + ret = LZMA_HEADER_ERROR; + } else if (memusage > coder->memlimit) { + // The chain would need too much memory. + ret = LZMA_MEMLIMIT_ERROR; + } else { + // Memory usage is OK. Initialize the Block decoder. + ret = lzma_block_decoder_init( + &coder->block_decoder, + allocator, &coder->block_options); + } // Free the allocated filter options since they are needed // only to initialize the Block decoder. @@ -149,10 +219,9 @@ stream_decode(lzma_coder *coder, lzma_allocator *allocator, coder->block_options.filters = NULL; - // Check if Block enocoder initialization succeeded. Don't - // warn about unsupported check anymore since we did it - // earlier if it was needed. - if (ret != LZMA_OK && ret != LZMA_UNSUPPORTED_CHECK) + // Check if memory usage calculation and Block enocoder + // initialization succeeded. + if (ret != LZMA_OK) return ret; coder->sequence = SEQ_BLOCK; @@ -160,7 +229,7 @@ stream_decode(lzma_coder *coder, lzma_allocator *allocator, } case SEQ_BLOCK: { - lzma_ret ret = coder->block_decoder.code( + const lzma_ret ret = coder->block_decoder.code( coder->block_decoder.coder, allocator, in, in_pos, in_size, out, out_pos, out_size, action); @@ -180,6 +249,12 @@ stream_decode(lzma_coder *coder, lzma_allocator *allocator, } case SEQ_INDEX: { + // If we don't have any input, don't call + // lzma_index_hash_decode() since it would return + // LZMA_BUF_ERROR, which we must not do here. + if (*in_pos >= in_size) + return LZMA_OK; + // Decode the Index and compare it to the hash calculated // from the sizes of the Blocks (if any). const lzma_ret ret = lzma_index_hash_decode(coder->index_hash, @@ -193,14 +268,17 @@ stream_decode(lzma_coder *coder, lzma_allocator *allocator, case SEQ_STREAM_FOOTER: // Copy the Stream Footer to the internal buffer. - bufcpy(in, in_pos, in_size, coder->buffer, &coder->buffer_pos, + lzma_bufcpy(in, in_pos, in_size, coder->buffer, &coder->pos, LZMA_STREAM_HEADER_SIZE); // Return if we didn't get the whole Stream Footer yet. - if (coder->buffer_pos < LZMA_STREAM_HEADER_SIZE) + if (coder->pos < LZMA_STREAM_HEADER_SIZE) return LZMA_OK; + coder->pos = 0; + // Decode the Stream Footer. + // FIXME LZMA_FORMAT_ERROR doesn't make sense here. lzma_stream_flags footer_flags; return_if_error(lzma_stream_footer_decode( &footer_flags, coder->buffer)); @@ -217,7 +295,48 @@ stream_decode(lzma_coder *coder, lzma_allocator *allocator, &footer_flags)) return LZMA_DATA_ERROR; - return LZMA_STREAM_END; + if (!coder->concatenated) + return LZMA_STREAM_END; + + coder->sequence = SEQ_STREAM_PADDING; + break; + + case SEQ_STREAM_PADDING: + assert(coder->concatenated); + + while (true) { + if (*in_pos >= in_size) { + // Unless LZMA_FINISH was used, we cannot + // know if there's more input coming later. + if (action != LZMA_FINISH) + return LZMA_OK; + + // Stream Padding must be a multiple of + // four bytes. + return coder->pos == 0 + ? LZMA_STREAM_END + : 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)); + break; + } + + ++*in_pos; + coder->pos = (coder->pos + 1) & 3; + } + + break; default: assert(0); @@ -231,16 +350,29 @@ stream_decode(lzma_coder *coder, lzma_allocator *allocator, static void stream_decoder_end(lzma_coder *coder, lzma_allocator *allocator) { - lzma_next_coder_end(&coder->block_decoder, allocator); + lzma_next_end(&coder->block_decoder, allocator); lzma_index_hash_end(coder->index_hash, allocator); lzma_free(coder, allocator); return; } -static lzma_ret -stream_decoder_init(lzma_next_coder *next, lzma_allocator *allocator) +static lzma_check +stream_decoder_see_check(const lzma_coder *coder) { + return coder->stream_flags.check; +} + + +extern lzma_ret +lzma_stream_decoder_init(lzma_next_coder *next, lzma_allocator *allocator, + uint64_t memlimit, uint32_t flags) +{ + lzma_next_coder_init(lzma_stream_decoder_init, next, allocator); + + if (flags & ~LZMA_SUPPORTED_FLAGS) + return LZMA_HEADER_ERROR; + if (next->coder == NULL) { next->coder = lzma_alloc(sizeof(lzma_coder), allocator); if (next->coder == NULL) @@ -248,40 +380,32 @@ stream_decoder_init(lzma_next_coder *next, lzma_allocator *allocator) next->code = &stream_decode; next->end = &stream_decoder_end; + next->see_check = &stream_decoder_see_check; next->coder->block_decoder = LZMA_NEXT_CODER_INIT; next->coder->index_hash = NULL; } - // Initialize the Index hash used to verify the Index. - next->coder->index_hash = lzma_index_hash_init( - next->coder->index_hash, allocator); - if (next->coder->index_hash == NULL) - return LZMA_MEM_ERROR; - - // Reset the rest of the variables. - next->coder->sequence = SEQ_STREAM_HEADER; - next->coder->block_options.filters = NULL; - next->coder->buffer_pos = 0; + next->coder->memlimit = memlimit; + next->coder->warn_no_check = (flags & LZMA_WARN_NO_CHECK) != 0; + next->coder->warn_unsupported_check + = (flags & LZMA_WARN_UNSUPPORTED_CHECK) != 0; + next->coder->tell_check = (flags & LZMA_TELL_CHECK) != 0; + next->coder->concatenated + = (flags & LZMA_CONCATENATED) != 0; - return LZMA_OK; -} - - -extern lzma_ret -lzma_stream_decoder_init(lzma_next_coder *next, lzma_allocator *allocator) -{ - lzma_next_coder_init0(stream_decoder_init, next, allocator); + return stream_decoder_reset(next->coder, allocator); } extern LZMA_API lzma_ret -lzma_stream_decoder(lzma_stream *strm) +lzma_stream_decoder(lzma_stream *strm, uint64_t memlimit, uint32_t flags) { - lzma_next_strm_init0(strm, stream_decoder_init); + 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; +// strm->internal->supported_actions[LZMA_SYNC_FLUSH] = true; // FIXME + strm->internal->supported_actions[LZMA_FINISH] = true; return LZMA_OK; } |