diff options
Diffstat (limited to 'lib/zstd/decompress/zstd_decompress.c')
| -rw-r--r-- | lib/zstd/decompress/zstd_decompress.c | 80 |
1 files changed, 63 insertions, 17 deletions
diff --git a/lib/zstd/decompress/zstd_decompress.c b/lib/zstd/decompress/zstd_decompress.c index b4d81d84479a..b9b935a9f5c0 100644 --- a/lib/zstd/decompress/zstd_decompress.c +++ b/lib/zstd/decompress/zstd_decompress.c @@ -53,7 +53,6 @@ * Dependencies *********************************************************/ #include "../common/zstd_deps.h" /* ZSTD_memcpy, ZSTD_memmove, ZSTD_memset */ -#include "../common/cpu.h" /* bmi2 */ #include "../common/mem.h" /* low level memory routines */ #define FSE_STATIC_LINKING_ONLY #include "../common/fse.h" @@ -252,11 +251,11 @@ static void ZSTD_initDCtx_internal(ZSTD_DCtx* dctx) dctx->inBuffSize = 0; dctx->outBuffSize = 0; dctx->streamStage = zdss_init; - dctx->legacyContext = NULL; - dctx->previousLegacyVersion = 0; dctx->noForwardProgress = 0; dctx->oversizedDuration = 0; - dctx->bmi2 = ZSTD_cpuid_bmi2(ZSTD_cpuid()); +#if DYNAMIC_BMI2 + dctx->bmi2 = ZSTD_cpuSupportsBmi2(); +#endif dctx->ddictSet = NULL; ZSTD_DCtx_resetParameters(dctx); #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION @@ -277,8 +276,7 @@ ZSTD_DCtx* ZSTD_initStaticDCtx(void *workspace, size_t workspaceSize) return dctx; } -ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem) -{ +static ZSTD_DCtx* ZSTD_createDCtx_internal(ZSTD_customMem customMem) { if ((!customMem.customAlloc) ^ (!customMem.customFree)) return NULL; { ZSTD_DCtx* const dctx = (ZSTD_DCtx*)ZSTD_customMalloc(sizeof(*dctx), customMem); @@ -289,10 +287,15 @@ ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem) } } +ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem) +{ + return ZSTD_createDCtx_internal(customMem); +} + ZSTD_DCtx* ZSTD_createDCtx(void) { DEBUGLOG(3, "ZSTD_createDCtx"); - return ZSTD_createDCtx_advanced(ZSTD_defaultCMem); + return ZSTD_createDCtx_internal(ZSTD_defaultCMem); } static void ZSTD_clearDict(ZSTD_DCtx* dctx) @@ -370,6 +373,19 @@ unsigned ZSTD_isFrame(const void* buffer, size_t size) return 0; } +/*! ZSTD_isSkippableFrame() : + * Tells if the content of `buffer` starts with a valid Frame Identifier for a skippable frame. + * Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0. + */ +unsigned ZSTD_isSkippableFrame(const void* buffer, size_t size) +{ + if (size < ZSTD_FRAMEIDSIZE) return 0; + { U32 const magic = MEM_readLE32(buffer); + if ((magic & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) return 1; + } + return 0; +} + /* ZSTD_frameHeaderSize_internal() : * srcSize must be large enough to reach header size fields. * note : only works for formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless. @@ -497,7 +513,6 @@ size_t ZSTD_getFrameHeader(ZSTD_frameHeader* zfhPtr, const void* src, size_t src return ZSTD_getFrameHeader_advanced(zfhPtr, src, srcSize, ZSTD_f_zstd1); } - /* ZSTD_getFrameContentSize() : * compatible with legacy mode * @return : decompressed size of the single frame pointed to be `src` if known, otherwise @@ -532,6 +547,37 @@ static size_t readSkippableFrameSize(void const* src, size_t srcSize) } } +/*! ZSTD_readSkippableFrame() : + * Retrieves a zstd skippable frame containing data given by src, and writes it to dst buffer. + * + * The parameter magicVariant will receive the magicVariant that was supplied when the frame was written, + * i.e. magicNumber - ZSTD_MAGIC_SKIPPABLE_START. This can be NULL if the caller is not interested + * in the magicVariant. + * + * Returns an error if destination buffer is not large enough, or if the frame is not skippable. + * + * @return : number of bytes written or a ZSTD error. + */ +ZSTDLIB_API size_t ZSTD_readSkippableFrame(void* dst, size_t dstCapacity, unsigned* magicVariant, + const void* src, size_t srcSize) +{ + U32 const magicNumber = MEM_readLE32(src); + size_t skippableFrameSize = readSkippableFrameSize(src, srcSize); + size_t skippableContentSize = skippableFrameSize - ZSTD_SKIPPABLEHEADERSIZE; + + /* check input validity */ + RETURN_ERROR_IF(!ZSTD_isSkippableFrame(src, srcSize), frameParameter_unsupported, ""); + RETURN_ERROR_IF(skippableFrameSize < ZSTD_SKIPPABLEHEADERSIZE || skippableFrameSize > srcSize, srcSize_wrong, ""); + RETURN_ERROR_IF(skippableContentSize > dstCapacity, dstSize_tooSmall, ""); + + /* deliver payload */ + if (skippableContentSize > 0 && dst != NULL) + ZSTD_memcpy(dst, (const BYTE *)src + ZSTD_SKIPPABLEHEADERSIZE, skippableContentSize); + if (magicVariant != NULL) + *magicVariant = magicNumber - ZSTD_MAGIC_SKIPPABLE_START; + return skippableContentSize; +} + /* ZSTD_findDecompressedSize() : * compatible with legacy mode * `srcSize` must be the exact length of some number of ZSTD compressed and/or @@ -824,7 +870,7 @@ static size_t ZSTD_decompressFrame(ZSTD_DCtx* dctx, switch(blockProperties.blockType) { case bt_compressed: - decodedSize = ZSTD_decompressBlock_internal(dctx, op, (size_t)(oend-op), ip, cBlockSize, /* frame */ 1); + decodedSize = ZSTD_decompressBlock_internal(dctx, op, (size_t)(oend-op), ip, cBlockSize, /* frame */ 1, not_streaming); break; case bt_raw : decodedSize = ZSTD_copyRawBlock(op, (size_t)(oend-op), ip, cBlockSize); @@ -976,7 +1022,7 @@ size_t ZSTD_decompress(void* dst, size_t dstCapacity, const void* src, size_t sr { #if defined(ZSTD_HEAPMODE) && (ZSTD_HEAPMODE>=1) size_t regenSize; - ZSTD_DCtx* const dctx = ZSTD_createDCtx(); + ZSTD_DCtx* const dctx = ZSTD_createDCtx_internal(ZSTD_defaultCMem); RETURN_ERROR_IF(dctx==NULL, memory_allocation, "NULL pointer!"); regenSize = ZSTD_decompressDCtx(dctx, dst, dstCapacity, src, srcSize); ZSTD_freeDCtx(dctx); @@ -996,7 +1042,7 @@ size_t ZSTD_decompress(void* dst, size_t dstCapacity, const void* src, size_t sr size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx) { return dctx->expected; } /* - * Similar to ZSTD_nextSrcSizeToDecompress(), but when when a block input can be streamed, + * Similar to ZSTD_nextSrcSizeToDecompress(), but when a block input can be streamed, * we allow taking a partial block as the input. Currently only raw uncompressed blocks can * be streamed. * @@ -1010,7 +1056,7 @@ static size_t ZSTD_nextSrcSizeToDecompressWithInputSize(ZSTD_DCtx* dctx, size_t return dctx->expected; if (dctx->bType != bt_raw) return dctx->expected; - return MIN(MAX(inputSize, 1), dctx->expected); + return BOUNDED(1, inputSize, dctx->expected); } ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx) { @@ -1116,7 +1162,7 @@ size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, c { case bt_compressed: DEBUGLOG(5, "ZSTD_decompressContinue: case bt_compressed"); - rSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, /* frame */ 1); + rSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, /* frame */ 1, is_streaming); dctx->expected = 0; /* Streaming not supported */ break; case bt_raw : @@ -1438,7 +1484,7 @@ size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx, ZSTD_DStream* ZSTD_createDStream(void) { DEBUGLOG(3, "ZSTD_createDStream"); - return ZSTD_createDStream_advanced(ZSTD_defaultCMem); + return ZSTD_createDCtx_internal(ZSTD_defaultCMem); } ZSTD_DStream* ZSTD_initStaticDStream(void *workspace, size_t workspaceSize) @@ -1448,7 +1494,7 @@ ZSTD_DStream* ZSTD_initStaticDStream(void *workspace, size_t workspaceSize) ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem) { - return ZSTD_createDCtx_advanced(customMem); + return ZSTD_createDCtx_internal(customMem); } size_t ZSTD_freeDStream(ZSTD_DStream* zds) @@ -1708,7 +1754,8 @@ size_t ZSTD_sizeof_DStream(const ZSTD_DStream* dctx) size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long long frameContentSize) { size_t const blockSize = (size_t) MIN(windowSize, ZSTD_BLOCKSIZE_MAX); - unsigned long long const neededRBSize = windowSize + blockSize + (WILDCOPY_OVERLENGTH * 2); + /* space is needed to store the litbuffer after the output of a given block without stomping the extDict of a previous run, as well as to cover both windows against wildcopy*/ + unsigned long long const neededRBSize = windowSize + blockSize + ZSTD_BLOCKSIZE_MAX + (WILDCOPY_OVERLENGTH * 2); unsigned long long const neededSize = MIN(frameContentSize, neededRBSize); size_t const minRBSize = (size_t) neededSize; RETURN_ERROR_IF((unsigned long long)minRBSize != neededSize, @@ -1842,7 +1889,6 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB DEBUGLOG(5, "stage zdss_init => transparent reset "); zds->streamStage = zdss_loadHeader; zds->lhSize = zds->inPos = zds->outStart = zds->outEnd = 0; - zds->legacyVersion = 0; zds->hostageByte = 0; zds->expectedOutBuffer = *output; ZSTD_FALLTHROUGH; |