Merge pull request #1553 from shakeelrao/legacy-bound

Add legacy support to decompressBound

lib/common/zstd_internal.h

@@ -242,6 +242,17 @@ typedef struct {
     U32   longLengthPos;
 } seqStore_t;
 
+/**
+ * Contains the compressed frame size and an upper-bound for the decompressed frame size.
+ * Note: before using `compressedSize`, check for errors using ZSTD_isError().
+ *       similarly, before using `decompressedBound`, check for errors using:
+ *          `decompressedBound != ZSTD_CONTENTSIZE_ERROR`
+ */
+typedef struct {
+    size_t compressedSize;
+    unsigned long long decompressedBound;
+} ZSTD_frameSizeInfo;   /* decompress & legacy */
+
 const seqStore_t* ZSTD_getSeqStore(const ZSTD_CCtx* ctx);   /* compress & dictBuilder */
 void ZSTD_seqToCodes(const seqStore_t* seqStorePtr);   /* compress, dictBuilder, decodeCorpus (shouldn't get its definition from here) */
 

lib/decompress/zstd_decompress.c

@@ -433,17 +433,6 @@ static size_t ZSTD_decodeFrameHeader(ZSTD_DCtx* dctx, const void* src, size_t he
     return 0;
 }
 
-/**
- * Contains the compressed frame size and an upper-bound for the decompressed frame size.
- * Note: before using `compressedSize` you must check for errors using ZSTD_isError().
- *       similarly, before using `decompressedBound`, you must check for errors using:
- *          `decompressedBound` != ZSTD_CONTENTSIZE_ERROR
- */
-typedef struct {
-    size_t compressedSize;
-    unsigned long long decompressedBound;
-} ZSTD_frameSizeInfo;
-
 static ZSTD_frameSizeInfo ZSTD_errorFrameSizeInfo(size_t ret)
 {
     ZSTD_frameSizeInfo frameSizeInfo;
@@ -459,7 +448,7 @@ static ZSTD_frameSizeInfo ZSTD_findFrameSizeInfo(const void* src, size_t srcSize
 
 #if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
     if (ZSTD_isLegacy(src, srcSize))
-        return ZSTD_errorFrameSizeInfo(ZSTD_findFrameCompressedSizeLegacy(src, srcSize));
+        return ZSTD_findFrameSizeInfoLegacy(src, srcSize);
 #endif
 
     if ((srcSize >= ZSTD_SKIPPABLEHEADERSIZE)
@@ -529,7 +518,7 @@ size_t ZSTD_findFrameCompressedSize(const void *src, size_t srcSize)
 
 
 /** ZSTD_decompressBound() :
- *  currently incompatible with legacy mode
+ *  compatible with legacy mode
  *  `src` must point to the start of a ZSTD frame or a skippeable frame
  *  `srcSize` must be at least as large as the frame contained
  *  @return : the maximum decompressed size of the compressed source

lib/legacy/zstd_legacy.h

@@ -20,7 +20,7 @@ extern "C" {
 ***************************************/
 #include "mem.h"            /* MEM_STATIC */
 #include "error_private.h"  /* ERROR */
-#include "zstd.h"           /* ZSTD_inBuffer, ZSTD_outBuffer */
+#include "zstd_internal.h"  /* ZSTD_inBuffer, ZSTD_outBuffer, ZSTD_frameSizeInfo */
 
 #if !defined (ZSTD_LEGACY_SUPPORT) || (ZSTD_LEGACY_SUPPORT == 0)
 #  undef ZSTD_LEGACY_SUPPORT
@@ -178,43 +178,73 @@ MEM_STATIC size_t ZSTD_decompressLegacy(
     }
 }
 
-MEM_STATIC size_t ZSTD_findFrameCompressedSizeLegacy(const void *src,
+MEM_STATIC ZSTD_frameSizeInfo ZSTD_findFrameSizeInfoLegacy(const void *src, size_t srcSize)
-                                             size_t compressedSize)
 {
-    U32 const version = ZSTD_isLegacy(src, compressedSize);
+    ZSTD_frameSizeInfo frameSizeInfo;
+    U32 const version = ZSTD_isLegacy(src, srcSize);
     switch(version)
     {
 #if (ZSTD_LEGACY_SUPPORT <= 1)
         case 1 :
-            return ZSTDv01_findFrameCompressedSize(src, compressedSize);
+            ZSTDv01_findFrameSizeInfoLegacy(src, srcSize,
+                &frameSizeInfo.compressedSize,
+                &frameSizeInfo.decompressedBound);
+            break;
 #endif
 #if (ZSTD_LEGACY_SUPPORT <= 2)
         case 2 :
-            return ZSTDv02_findFrameCompressedSize(src, compressedSize);
+            ZSTDv02_findFrameSizeInfoLegacy(src, srcSize,
+                &frameSizeInfo.compressedSize,
+                &frameSizeInfo.decompressedBound);
+            break;
 #endif
 #if (ZSTD_LEGACY_SUPPORT <= 3)
         case 3 :
-            return ZSTDv03_findFrameCompressedSize(src, compressedSize);
+            ZSTDv03_findFrameSizeInfoLegacy(src, srcSize,
+                &frameSizeInfo.compressedSize,
+                &frameSizeInfo.decompressedBound);
+            break;
 #endif
 #if (ZSTD_LEGACY_SUPPORT <= 4)
         case 4 :
-            return ZSTDv04_findFrameCompressedSize(src, compressedSize);
+            ZSTDv04_findFrameSizeInfoLegacy(src, srcSize,
+                &frameSizeInfo.compressedSize,
+                &frameSizeInfo.decompressedBound);
+            break;
 #endif
 #if (ZSTD_LEGACY_SUPPORT <= 5)
         case 5 :
-            return ZSTDv05_findFrameCompressedSize(src, compressedSize);
+            ZSTDv05_findFrameSizeInfoLegacy(src, srcSize,
+                &frameSizeInfo.compressedSize,
+                &frameSizeInfo.decompressedBound);
+            break;
 #endif
 #if (ZSTD_LEGACY_SUPPORT <= 6)
         case 6 :
-            return ZSTDv06_findFrameCompressedSize(src, compressedSize);
+            ZSTDv06_findFrameSizeInfoLegacy(src, srcSize,
+                &frameSizeInfo.compressedSize,
+                &frameSizeInfo.decompressedBound);
+            break;
 #endif
 #if (ZSTD_LEGACY_SUPPORT <= 7)
         case 7 :
-            return ZSTDv07_findFrameCompressedSize(src, compressedSize);
+            ZSTDv07_findFrameSizeInfoLegacy(src, srcSize,
+                &frameSizeInfo.compressedSize,
+                &frameSizeInfo.decompressedBound);
+            break;
 #endif
         default :
-            return ERROR(prefix_unknown);
+            frameSizeInfo.compressedSize = ERROR(prefix_unknown);
+            frameSizeInfo.decompressedBound = ZSTD_CONTENTSIZE_ERROR;
+            break;
     }
+    return frameSizeInfo;
+}
+
+MEM_STATIC size_t ZSTD_findFrameCompressedSizeLegacy(const void *src, size_t srcSize)
+{
+    ZSTD_frameSizeInfo frameSizeInfo = ZSTD_findFrameSizeInfoLegacy(src, srcSize);
+    return frameSizeInfo.compressedSize;
 }
 
 MEM_STATIC size_t ZSTD_freeLegacyStreamContext(void* legacyContext, U32 version)

lib/legacy/zstd_v01.c

@@ -1336,6 +1336,8 @@ static const U32 ZSTD_magicNumber = 0xFD2FB51E;   /* 3rd version : seqNb header
 #define LITERAL_NOENTROPY 63
 #define COMMAND_NOENTROPY 7   /* to remove */
 
+#define ZSTD_CONTENTSIZE_ERROR   (0ULL - 2)
+
 static const size_t ZSTD_blockHeaderSize = 3;
 static const size_t ZSTD_frameHeaderSize = 4;
 
@@ -1999,36 +2001,59 @@ size_t ZSTDv01_decompress(void* dst, size_t maxDstSize, const void* src, size_t
     return ZSTDv01_decompressDCtx(&ctx, dst, maxDstSize, src, srcSize);
 }
 
-size_t ZSTDv01_findFrameCompressedSize(const void* src, size_t srcSize)
+/* ZSTD_errorFrameSizeInfoLegacy() :
+   assumes `cSize` and `dBound` are _not_ NULL */
+static void ZSTD_errorFrameSizeInfoLegacy(size_t* cSize, unsigned long long* dBound, size_t ret)
+{
+    *cSize = ret;
+    *dBound = ZSTD_CONTENTSIZE_ERROR;
+}
+
+void ZSTDv01_findFrameSizeInfoLegacy(const void *src, size_t srcSize, size_t* cSize, unsigned long long* dBound)
 {
     const BYTE* ip = (const BYTE*)src;
     size_t remainingSize = srcSize;
+    size_t nbBlocks = 0;
     U32 magicNumber;
     blockProperties_t blockProperties;
 
     /* Frame Header */
-    if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
+    if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) {
+        ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
+        return;
+    }
     magicNumber = ZSTD_readBE32(src);
-    if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
+    if (magicNumber != ZSTD_magicNumber) {
+        ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(prefix_unknown));
+        return;
+    }
     ip += ZSTD_frameHeaderSize; remainingSize -= ZSTD_frameHeaderSize;
 
     /* Loop on each block */
     while (1)
     {
         size_t blockSize = ZSTDv01_getcBlockSize(ip, remainingSize, &blockProperties);
-        if (ZSTDv01_isError(blockSize)) return blockSize;
+        if (ZSTDv01_isError(blockSize)) {
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, blockSize);
+            return;
+        }
 
         ip += ZSTD_blockHeaderSize;
         remainingSize -= ZSTD_blockHeaderSize;
-        if (blockSize > remainingSize) return ERROR(srcSize_wrong);
+        if (blockSize > remainingSize) {
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
+            return;
+        }
 
         if (blockSize == 0) break;   /* bt_end */
 
         ip += blockSize;
         remainingSize -= blockSize;
+        nbBlocks++;
     }
 
-    return ip - (const BYTE*)src;
+    *cSize = ip - (const BYTE*)src;
+    *dBound = nbBlocks * BLOCKSIZE;
 }
 
 /*******************************

lib/legacy/zstd_v01.h

@@ -35,13 +35,18 @@ ZSTDv01_decompress() : decompress ZSTD frames compliant with v0.1.x format
 size_t ZSTDv01_decompress( void* dst, size_t maxOriginalSize,
                      const void* src, size_t compressedSize);
 
-/**
+ /**
-ZSTDv01_getFrameSrcSize() : get the source length of a ZSTD frame compliant with v0.1.x format
+ ZSTDv01_findFrameSizeInfoLegacy() : get the source length and decompressed bound of a ZSTD frame compliant with v0.1.x format
-    compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
+     srcSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
-    return : the number of bytes that would be read to decompress this frame
+     cSize (output parameter)  : the number of bytes that would be read to decompress this frame
-             or an errorCode if it fails (which can be tested using ZSTDv01_isError())
+                                 or an error code if it fails (which can be tested using ZSTDv01_isError())
-*/
+     dBound (output parameter) : an upper-bound for the decompressed size of the data in the frame
-size_t ZSTDv01_findFrameCompressedSize(const void* src, size_t compressedSize);
+                                 or ZSTD_CONTENTSIZE_ERROR if an error occurs
+
+     note : assumes `cSize` and `dBound` are _not_ NULL.
+ */
+void ZSTDv01_findFrameSizeInfoLegacy(const void *src, size_t srcSize,
+                                     size_t* cSize, unsigned long long* dBound);
 
 /**
 ZSTDv01_isError() : tells if the result of ZSTDv01_decompress() is an error

lib/legacy/zstd_v02.c

@@ -2728,6 +2728,8 @@ static size_t HUF_decompress (void* dst, size_t dstSize, const void* cSrc, size_
 #define LITERAL_NOENTROPY 63
 #define COMMAND_NOENTROPY 7   /* to remove */
 
+#define ZSTD_CONTENTSIZE_ERROR   (0ULL - 2)
+
 static const size_t ZSTD_blockHeaderSize = 3;
 static const size_t ZSTD_frameHeaderSize = 4;
 
@@ -3312,37 +3314,59 @@ static size_t ZSTD_decompress(void* dst, size_t maxDstSize, const void* src, siz
     return ZSTD_decompressDCtx(&ctx, dst, maxDstSize, src, srcSize);
 }
 
-static size_t ZSTD_findFrameCompressedSize(const void *src, size_t srcSize)
+/* ZSTD_errorFrameSizeInfoLegacy() :
+   assumes `cSize` and `dBound` are _not_ NULL */
+static void ZSTD_errorFrameSizeInfoLegacy(size_t* cSize, unsigned long long* dBound, size_t ret)
 {
+    *cSize = ret;
+    *dBound = ZSTD_CONTENTSIZE_ERROR;
+}
 
+void ZSTDv02_findFrameSizeInfoLegacy(const void *src, size_t srcSize, size_t* cSize, unsigned long long* dBound)
+{
     const BYTE* ip = (const BYTE*)src;
     size_t remainingSize = srcSize;
+    size_t nbBlocks = 0;
     U32 magicNumber;
     blockProperties_t blockProperties;
 
     /* Frame Header */
-    if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
+    if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) {
+        ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
+        return;
+    }
     magicNumber = MEM_readLE32(src);
-    if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
+    if (magicNumber != ZSTD_magicNumber) {
+        ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(prefix_unknown));
+        return;
+    }
     ip += ZSTD_frameHeaderSize; remainingSize -= ZSTD_frameHeaderSize;
 
     /* Loop on each block */
     while (1)
     {
         size_t cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties);
-        if (ZSTD_isError(cBlockSize)) return cBlockSize;
+        if (ZSTD_isError(cBlockSize)) {
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, cBlockSize);
+            return;
+        }
 
         ip += ZSTD_blockHeaderSize;
         remainingSize -= ZSTD_blockHeaderSize;
-        if (cBlockSize > remainingSize) return ERROR(srcSize_wrong);
+        if (cBlockSize > remainingSize) {
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
+            return;
+        }
 
         if (cBlockSize == 0) break;   /* bt_end */
 
         ip += cBlockSize;
         remainingSize -= cBlockSize;
+        nbBlocks++;
     }
 
-    return ip - (const BYTE*)src;
+    *cSize = ip - (const BYTE*)src;
+    *dBound = nbBlocks * BLOCKSIZE;
 }
 
 /*******************************
@@ -3458,11 +3482,6 @@ size_t ZSTDv02_decompress( void* dst, size_t maxOriginalSize,
     return ZSTD_decompress(dst, maxOriginalSize, src, compressedSize);
 }
 
-size_t ZSTDv02_findFrameCompressedSize(const void *src, size_t compressedSize)
-{
-    return ZSTD_findFrameCompressedSize(src, compressedSize);
-}
-
 ZSTDv02_Dctx* ZSTDv02_createDCtx(void)
 {
     return (ZSTDv02_Dctx*)ZSTD_createDCtx();

lib/legacy/zstd_v02.h

@@ -35,13 +35,18 @@ ZSTDv02_decompress() : decompress ZSTD frames compliant with v0.2.x format
 size_t ZSTDv02_decompress( void* dst, size_t maxOriginalSize,
                      const void* src, size_t compressedSize);
 
-/**
+ /**
-ZSTDv02_getFrameSrcSize() : get the source length of a ZSTD frame compliant with v0.2.x format
+ ZSTDv02_findFrameSizeInfoLegacy() : get the source length and decompressed bound of a ZSTD frame compliant with v0.2.x format
-    compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
+     srcSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
-    return : the number of bytes that would be read to decompress this frame
+     cSize (output parameter)  : the number of bytes that would be read to decompress this frame
-             or an errorCode if it fails (which can be tested using ZSTDv02_isError())
+                                 or an error code if it fails (which can be tested using ZSTDv01_isError())
-*/
+     dBound (output parameter) : an upper-bound for the decompressed size of the data in the frame
-size_t ZSTDv02_findFrameCompressedSize(const void* src, size_t compressedSize);
+                                 or ZSTD_CONTENTSIZE_ERROR if an error occurs
+
+    note : assumes `cSize` and `dBound` are _not_ NULL.
+ */
+void ZSTDv02_findFrameSizeInfoLegacy(const void *src, size_t srcSize,
+                                     size_t* cSize, unsigned long long* dBound);
 
 /**
 ZSTDv02_isError() : tells if the result of ZSTDv02_decompress() is an error

lib/legacy/zstd_v03.c

@@ -2369,6 +2369,8 @@ static size_t HUF_decompress (void* dst, size_t dstSize, const void* cSrc, size_
 #define LITERAL_NOENTROPY 63
 #define COMMAND_NOENTROPY 7   /* to remove */
 
+#define ZSTD_CONTENTSIZE_ERROR   (0ULL - 2)
+
 static const size_t ZSTD_blockHeaderSize = 3;
 static const size_t ZSTD_frameHeaderSize = 4;
 
@@ -2953,36 +2955,59 @@ static size_t ZSTD_decompress(void* dst, size_t maxDstSize, const void* src, siz
     return ZSTD_decompressDCtx(&ctx, dst, maxDstSize, src, srcSize);
 }
 
-static size_t ZSTD_findFrameCompressedSize(const void* src, size_t srcSize)
+/* ZSTD_errorFrameSizeInfoLegacy() :
+   assumes `cSize` and `dBound` are _not_ NULL */
+MEM_STATIC void ZSTD_errorFrameSizeInfoLegacy(size_t* cSize, unsigned long long* dBound, size_t ret)
+{
+    *cSize = ret;
+    *dBound = ZSTD_CONTENTSIZE_ERROR;
+}
+
+void ZSTDv03_findFrameSizeInfoLegacy(const void *src, size_t srcSize, size_t* cSize, unsigned long long* dBound)
 {
     const BYTE* ip = (const BYTE*)src;
     size_t remainingSize = srcSize;
+    size_t nbBlocks = 0;
     U32 magicNumber;
     blockProperties_t blockProperties;
 
     /* Frame Header */
-    if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) return ERROR(srcSize_wrong);
+    if (srcSize < ZSTD_frameHeaderSize+ZSTD_blockHeaderSize) {
+        ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
+        return;
+    }
     magicNumber = MEM_readLE32(src);
-    if (magicNumber != ZSTD_magicNumber) return ERROR(prefix_unknown);
+    if (magicNumber != ZSTD_magicNumber) {
+        ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(prefix_unknown));
+        return;
+    }
     ip += ZSTD_frameHeaderSize; remainingSize -= ZSTD_frameHeaderSize;
 
     /* Loop on each block */
     while (1)
     {
         size_t cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties);
-        if (ZSTD_isError(cBlockSize)) return cBlockSize;
+        if (ZSTD_isError(cBlockSize)) {
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, cBlockSize);
+            return;
+        }
 
         ip += ZSTD_blockHeaderSize;
         remainingSize -= ZSTD_blockHeaderSize;
-        if (cBlockSize > remainingSize) return ERROR(srcSize_wrong);
+        if (cBlockSize > remainingSize) {
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
+            return;
+        }
 
         if (cBlockSize == 0) break;   /* bt_end */
 
         ip += cBlockSize;
         remainingSize -= cBlockSize;
+        nbBlocks++;
     }
 
-    return ip - (const BYTE*)src;
+    *cSize = ip - (const BYTE*)src;
+    *dBound = nbBlocks * BLOCKSIZE;
 }
 
 
@@ -3099,11 +3124,6 @@ size_t ZSTDv03_decompress( void* dst, size_t maxOriginalSize,
     return ZSTD_decompress(dst, maxOriginalSize, src, compressedSize);
 }
 
-size_t ZSTDv03_findFrameCompressedSize(const void* src, size_t srcSize)
-{
-    return ZSTD_findFrameCompressedSize(src, srcSize);
-}
-
 ZSTDv03_Dctx* ZSTDv03_createDCtx(void)
 {
     return (ZSTDv03_Dctx*)ZSTD_createDCtx();

lib/legacy/zstd_v03.h

@@ -35,13 +35,18 @@ ZSTDv03_decompress() : decompress ZSTD frames compliant with v0.3.x format
 size_t ZSTDv03_decompress( void* dst, size_t maxOriginalSize,
                      const void* src, size_t compressedSize);
 
-/**
+ /**
-ZSTDv03_getFrameSrcSize() : get the source length of a ZSTD frame compliant with v0.3.x format
+ ZSTDv03_findFrameSizeInfoLegacy() : get the source length and decompressed bound of a ZSTD frame compliant with v0.3.x format
-    compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
+     srcSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
-    return : the number of bytes that would be read to decompress this frame
+     cSize (output parameter)  : the number of bytes that would be read to decompress this frame
-             or an errorCode if it fails (which can be tested using ZSTDv03_isError())
+                                 or an error code if it fails (which can be tested using ZSTDv01_isError())
-*/
+     dBound (output parameter) : an upper-bound for the decompressed size of the data in the frame
-size_t ZSTDv03_findFrameCompressedSize(const void* src, size_t compressedSize);
+                                 or ZSTD_CONTENTSIZE_ERROR if an error occurs
+
+    note : assumes `cSize` and `dBound` are _not_ NULL.
+ */
+ void ZSTDv03_findFrameSizeInfoLegacy(const void *src, size_t srcSize,
+                                      size_t* cSize, unsigned long long* dBound);
 
     /**
 ZSTDv03_isError() : tells if the result of ZSTDv03_decompress() is an error

lib/legacy/zstd_v04.c

@@ -373,6 +373,8 @@ static const size_t ZSTD_frameHeaderSize_min = 5;
 #define MIN_SEQUENCES_SIZE (2 /*seqNb*/ + 2 /*dumps*/ + 3 /*seqTables*/ + 1 /*bitStream*/)
 #define MIN_CBLOCK_SIZE (3 /*litCSize*/ + MIN_SEQUENCES_SIZE)
 
+#define ZSTD_CONTENTSIZE_ERROR   (0ULL - 2)
+
 typedef enum { bt_compressed, bt_raw, bt_rle, bt_end } blockType_t;
 
 
@@ -3119,34 +3121,57 @@ static size_t ZSTD_decompress_usingDict(ZSTD_DCtx* ctx,
     return op-ostart;
 }
 
-static size_t ZSTD_findFrameCompressedSize(const void* src, size_t srcSize)
+/* ZSTD_errorFrameSizeInfoLegacy() :
+   assumes `cSize` and `dBound` are _not_ NULL */
+static void ZSTD_errorFrameSizeInfoLegacy(size_t* cSize, unsigned long long* dBound, size_t ret)
+{
+    *cSize = ret;
+    *dBound = ZSTD_CONTENTSIZE_ERROR;
+}
+
+void ZSTDv04_findFrameSizeInfoLegacy(const void *src, size_t srcSize, size_t* cSize, unsigned long long* dBound)
 {
     const BYTE* ip = (const BYTE*)src;
     size_t remainingSize = srcSize;
+    size_t nbBlocks = 0;
     blockProperties_t blockProperties;
 
     /* Frame Header */
-    if (srcSize < ZSTD_frameHeaderSize_min) return ERROR(srcSize_wrong);
+    if (srcSize < ZSTD_frameHeaderSize_min) {
-    if (MEM_readLE32(src) != ZSTD_MAGICNUMBER) return ERROR(prefix_unknown);
+        ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
+        return;
+    }
+    if (MEM_readLE32(src) != ZSTD_MAGICNUMBER) {
+        ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(prefix_unknown));
+        return;
+    }
     ip += ZSTD_frameHeaderSize_min; remainingSize -= ZSTD_frameHeaderSize_min;
 
     /* Loop on each block */
     while (1)
     {
         size_t cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties);
-        if (ZSTD_isError(cBlockSize)) return cBlockSize;
+        if (ZSTD_isError(cBlockSize)) {
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, cBlockSize);
+            return;
+        }
 
         ip += ZSTD_blockHeaderSize;
         remainingSize -= ZSTD_blockHeaderSize;
-        if (cBlockSize > remainingSize) return ERROR(srcSize_wrong);
+        if (cBlockSize > remainingSize) {
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
+            return;
+        }
 
         if (cBlockSize == 0) break;   /* bt_end */
 
         ip += cBlockSize;
         remainingSize -= cBlockSize;
+        nbBlocks++;
     }
 
-    return ip - (const BYTE*)src;
+    *cSize = ip - (const BYTE*)src;
+    *dBound = nbBlocks * BLOCKSIZE;
 }
 
 /* ******************************
@@ -3578,11 +3603,6 @@ size_t ZSTDv04_decompress(void* dst, size_t maxDstSize, const void* src, size_t
 #endif
 }
 
-size_t ZSTDv04_findFrameCompressedSize(const void* src, size_t srcSize)
-{
-    return ZSTD_findFrameCompressedSize(src, srcSize);
-}
-
 size_t ZSTDv04_resetDCtx(ZSTDv04_Dctx* dctx) { return ZSTD_resetDCtx(dctx); }
 
 size_t ZSTDv04_nextSrcSizeToDecompress(ZSTDv04_Dctx* dctx)

lib/legacy/zstd_v04.h

@@ -35,13 +35,18 @@ ZSTDv04_decompress() : decompress ZSTD frames compliant with v0.4.x format
 size_t ZSTDv04_decompress( void* dst, size_t maxOriginalSize,
                      const void* src, size_t compressedSize);
 
-/**
+ /**
-ZSTDv04_getFrameSrcSize() : get the source length of a ZSTD frame compliant with v0.4.x format
+ ZSTDv04_findFrameSizeInfoLegacy() : get the source length and decompressed bound of a ZSTD frame compliant with v0.4.x format
-    compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
+     srcSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
-    return : the number of bytes that would be read to decompress this frame
+     cSize (output parameter)  : the number of bytes that would be read to decompress this frame
-             or an errorCode if it fails (which can be tested using ZSTDv04_isError())
+                                 or an error code if it fails (which can be tested using ZSTDv01_isError())
-*/
+     dBound (output parameter) : an upper-bound for the decompressed size of the data in the frame
-size_t ZSTDv04_findFrameCompressedSize(const void* src, size_t compressedSize);
+                                 or ZSTD_CONTENTSIZE_ERROR if an error occurs
+
+    note : assumes `cSize` and `dBound` are _not_ NULL.
+ */
+ void ZSTDv04_findFrameSizeInfoLegacy(const void *src, size_t srcSize,
+                                      size_t* cSize, unsigned long long* dBound);
 
 /**
 ZSTDv04_isError() : tells if the result of ZSTDv04_decompress() is an error

lib/legacy/zstd_v05.c

@@ -491,6 +491,8 @@ static const size_t ZSTDv05_frameHeaderSize_min = 5;
 
 #define WILDCOPY_OVERLENGTH 8
 
+#define ZSTD_CONTENTSIZE_ERROR   (0ULL - 2)
+
 typedef enum { bt_compressed, bt_raw, bt_rle, bt_end } blockType_t;
 
 
@@ -3508,34 +3510,57 @@ size_t ZSTDv05_decompress(void* dst, size_t maxDstSize, const void* src, size_t
 #endif
 }
 
-size_t ZSTDv05_findFrameCompressedSize(const void *src, size_t srcSize)
+/* ZSTD_errorFrameSizeInfoLegacy() :
+   assumes `cSize` and `dBound` are _not_ NULL */
+static void ZSTD_errorFrameSizeInfoLegacy(size_t* cSize, unsigned long long* dBound, size_t ret)
+{
+    *cSize = ret;
+    *dBound = ZSTD_CONTENTSIZE_ERROR;
+}
+
+void ZSTDv05_findFrameSizeInfoLegacy(const void *src, size_t srcSize, size_t* cSize, unsigned long long* dBound)
 {
     const BYTE* ip = (const BYTE*)src;
     size_t remainingSize = srcSize;
+    size_t nbBlocks = 0;
     blockProperties_t blockProperties;
 
     /* Frame Header */
-    if (srcSize < ZSTDv05_frameHeaderSize_min) return ERROR(srcSize_wrong);
+    if (srcSize < ZSTDv05_frameHeaderSize_min) {
-    if (MEM_readLE32(src) != ZSTDv05_MAGICNUMBER) return ERROR(prefix_unknown);
+        ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
+        return;
+    }
+    if (MEM_readLE32(src) != ZSTDv05_MAGICNUMBER) {
+        ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(prefix_unknown));
+        return;
+    }
     ip += ZSTDv05_frameHeaderSize_min; remainingSize -= ZSTDv05_frameHeaderSize_min;
 
     /* Loop on each block */
     while (1)
     {
         size_t cBlockSize = ZSTDv05_getcBlockSize(ip, remainingSize, &blockProperties);
-        if (ZSTDv05_isError(cBlockSize)) return cBlockSize;
+        if (ZSTDv05_isError(cBlockSize)) {
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, cBlockSize);
+            return;
+        }
 
         ip += ZSTDv05_blockHeaderSize;
         remainingSize -= ZSTDv05_blockHeaderSize;
-        if (cBlockSize > remainingSize) return ERROR(srcSize_wrong);
+        if (cBlockSize > remainingSize) {
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
+            return;
+        }
 
         if (cBlockSize == 0) break;   /* bt_end */
 
         ip += cBlockSize;
         remainingSize -= cBlockSize;
+        nbBlocks++;
     }
 
-    return ip - (const BYTE*)src;
+    *cSize = ip - (const BYTE*)src;
+    *dBound = nbBlocks * BLOCKSIZE;
 }
 
 /* ******************************

lib/legacy/zstd_v05.h

@@ -33,13 +33,18 @@ extern "C" {
 size_t ZSTDv05_decompress( void* dst, size_t dstCapacity,
                      const void* src, size_t compressedSize);
 
-/**
+ /**
-ZSTDv05_getFrameSrcSize() : get the source length of a ZSTD frame
+ ZSTDv05_findFrameSizeInfoLegacy() : get the source length and decompressed bound of a ZSTD frame compliant with v0.5.x format
-    compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
+     srcSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
-    return : the number of bytes that would be read to decompress this frame
+     cSize (output parameter)  : the number of bytes that would be read to decompress this frame
-             or an errorCode if it fails (which can be tested using ZSTDv05_isError())
+                                 or an error code if it fails (which can be tested using ZSTDv01_isError())
-*/
+     dBound (output parameter) : an upper-bound for the decompressed size of the data in the frame
-size_t ZSTDv05_findFrameCompressedSize(const void* src, size_t compressedSize);
+                                 or ZSTD_CONTENTSIZE_ERROR if an error occurs
+
+    note : assumes `cSize` and `dBound` are _not_ NULL.
+ */
+void ZSTDv05_findFrameSizeInfoLegacy(const void *src, size_t srcSize,
+                                     size_t* cSize, unsigned long long* dBound);
 
 /* *************************************
 *  Helper functions

lib/legacy/zstd_v06.c

@@ -506,6 +506,8 @@ typedef enum { bt_compressed, bt_raw, bt_rle, bt_end } blockType_t;
 #define FSEv06_ENCODING_STATIC  2
 #define FSEv06_ENCODING_DYNAMIC 3
 
+#define ZSTD_CONTENTSIZE_ERROR   (0ULL - 2)
+
 static const U32 LL_bits[MaxLL+1] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                                       1, 1, 1, 1, 2, 2, 3, 3, 4, 6, 7, 8, 9,10,11,12,
                                      13,14,15,16 };
@@ -3654,36 +3656,62 @@ size_t ZSTDv06_decompress(void* dst, size_t dstCapacity, const void* src, size_t
 #endif
 }
 
-size_t ZSTDv06_findFrameCompressedSize(const void* src, size_t srcSize)
+/* ZSTD_errorFrameSizeInfoLegacy() :
+   assumes `cSize` and `dBound` are _not_ NULL */
+static void ZSTD_errorFrameSizeInfoLegacy(size_t* cSize, unsigned long long* dBound, size_t ret)
+{
+    *cSize = ret;
+    *dBound = ZSTD_CONTENTSIZE_ERROR;
+}
+
+void ZSTDv06_findFrameSizeInfoLegacy(const void *src, size_t srcSize, size_t* cSize, unsigned long long* dBound)
 {
     const BYTE* ip = (const BYTE*)src;
     size_t remainingSize = srcSize;
+    size_t nbBlocks = 0;
     blockProperties_t blockProperties = { bt_compressed, 0 };
 
     /* Frame Header */
     {   size_t const frameHeaderSize = ZSTDv06_frameHeaderSize(src, ZSTDv06_frameHeaderSize_min);
-        if (ZSTDv06_isError(frameHeaderSize)) return frameHeaderSize;
+        if (ZSTDv06_isError(frameHeaderSize)) {
-        if (MEM_readLE32(src) != ZSTDv06_MAGICNUMBER) return ERROR(prefix_unknown);
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, frameHeaderSize);
-        if (srcSize < frameHeaderSize+ZSTDv06_blockHeaderSize) return ERROR(srcSize_wrong);
+            return;
+        }
+        if (MEM_readLE32(src) != ZSTDv06_MAGICNUMBER) {
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(prefix_unknown));
+            return;
+        }
+        if (srcSize < frameHeaderSize+ZSTDv06_blockHeaderSize) {
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
+            return;
+        }
         ip += frameHeaderSize; remainingSize -= frameHeaderSize;
     }
 
     /* Loop on each block */
     while (1) {
         size_t const cBlockSize = ZSTDv06_getcBlockSize(ip, remainingSize, &blockProperties);
-        if (ZSTDv06_isError(cBlockSize)) return cBlockSize;
+        if (ZSTDv06_isError(cBlockSize)) {
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, cBlockSize);
+            return;
+        }
 
         ip += ZSTDv06_blockHeaderSize;
         remainingSize -= ZSTDv06_blockHeaderSize;
-        if (cBlockSize > remainingSize) return ERROR(srcSize_wrong);
+        if (cBlockSize > remainingSize) {
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
+            return;
+        }
 
         if (cBlockSize == 0) break;   /* bt_end */
 
         ip += cBlockSize;
         remainingSize -= cBlockSize;
+        nbBlocks++;
     }
 
-    return ip - (const BYTE*)src;
+    *cSize = ip - (const BYTE*)src;
+    *dBound = nbBlocks * ZSTDv06_BLOCKSIZE_MAX;
 }
 
 /*_******************************

lib/legacy/zstd_v06.h

@@ -43,12 +43,17 @@ ZSTDLIBv06_API size_t ZSTDv06_decompress( void* dst, size_t dstCapacity,
                                     const void* src, size_t compressedSize);
 
 /**
-ZSTDv06_getFrameSrcSize() : get the source length of a ZSTD frame
+ZSTDv06_findFrameSizeInfoLegacy() : get the source length and decompressed bound of a ZSTD frame compliant with v0.6.x format
-    compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
+    srcSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
-    return : the number of bytes that would be read to decompress this frame
+    cSize (output parameter)  : the number of bytes that would be read to decompress this frame
-             or an errorCode if it fails (which can be tested using ZSTDv06_isError())
+                                or an error code if it fails (which can be tested using ZSTDv01_isError())
+    dBound (output parameter) : an upper-bound for the decompressed size of the data in the frame
+                                or ZSTD_CONTENTSIZE_ERROR if an error occurs
+
+    note : assumes `cSize` and `dBound` are _not_ NULL.
 */
-size_t ZSTDv06_findFrameCompressedSize(const void* src, size_t compressedSize);
+void ZSTDv06_findFrameSizeInfoLegacy(const void *src, size_t srcSize,
+                                     size_t* cSize, unsigned long long* dBound);
 
 /* *************************************
 *  Helper functions

lib/legacy/zstd_v07.c

@@ -2740,6 +2740,8 @@ typedef enum { lbt_huffman, lbt_repeat, lbt_raw, lbt_rle } litBlockType_t;
 #define FSEv07_ENCODING_STATIC  2
 #define FSEv07_ENCODING_DYNAMIC 3
 
+#define ZSTD_CONTENTSIZE_ERROR   (0ULL - 2)
+
 static const U32 LL_bits[MaxLL+1] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
                                       1, 1, 1, 1, 2, 2, 3, 3, 4, 6, 7, 8, 9,10,11,12,
                                      13,14,15,16 };
@@ -3895,19 +3897,40 @@ size_t ZSTDv07_decompress(void* dst, size_t dstCapacity, const void* src, size_t
 #endif
 }
 
-size_t ZSTDv07_findFrameCompressedSize(const void* src, size_t srcSize)
+/* ZSTD_errorFrameSizeInfoLegacy() :
+   assumes `cSize` and `dBound` are _not_ NULL */
+static void ZSTD_errorFrameSizeInfoLegacy(size_t* cSize, unsigned long long* dBound, size_t ret)
+{
+    *cSize = ret;
+    *dBound = ZSTD_CONTENTSIZE_ERROR;
+}
+
+void ZSTDv07_findFrameSizeInfoLegacy(const void *src, size_t srcSize, size_t* cSize, unsigned long long* dBound)
 {
     const BYTE* ip = (const BYTE*)src;
     size_t remainingSize = srcSize;
+    size_t nbBlocks = 0;
 
     /* check */
-    if (srcSize < ZSTDv07_frameHeaderSize_min+ZSTDv07_blockHeaderSize) return ERROR(srcSize_wrong);
+    if (srcSize < ZSTDv07_frameHeaderSize_min+ZSTDv07_blockHeaderSize) {
+        ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
+        return;
+    }
 
     /* Frame Header */
     {   size_t const frameHeaderSize = ZSTDv07_frameHeaderSize(src, ZSTDv07_frameHeaderSize_min);
-        if (ZSTDv07_isError(frameHeaderSize)) return frameHeaderSize;
+        if (ZSTDv07_isError(frameHeaderSize)) {
-        if (MEM_readLE32(src) != ZSTDv07_MAGICNUMBER) return ERROR(prefix_unknown);
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, frameHeaderSize);
-        if (srcSize < frameHeaderSize+ZSTDv07_blockHeaderSize) return ERROR(srcSize_wrong);
+            return;
+        }
+        if (MEM_readLE32(src) != ZSTDv07_MAGICNUMBER) {
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(prefix_unknown));
+            return;
+        }
+        if (srcSize < frameHeaderSize+ZSTDv07_blockHeaderSize) {
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
+            return;
+        }
         ip += frameHeaderSize; remainingSize -= frameHeaderSize;
     }
 
@@ -3915,20 +3938,28 @@ size_t ZSTDv07_findFrameCompressedSize(const void* src, size_t srcSize)
     while (1) {
         blockProperties_t blockProperties;
         size_t const cBlockSize = ZSTDv07_getcBlockSize(ip, remainingSize, &blockProperties);
-        if (ZSTDv07_isError(cBlockSize)) return cBlockSize;
+        if (ZSTDv07_isError(cBlockSize)) {
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, cBlockSize);
+            return;
+        }
 
         ip += ZSTDv07_blockHeaderSize;
         remainingSize -= ZSTDv07_blockHeaderSize;
 
         if (blockProperties.blockType == bt_end) break;
 
-        if (cBlockSize > remainingSize) return ERROR(srcSize_wrong);
+        if (cBlockSize > remainingSize) {
+            ZSTD_errorFrameSizeInfoLegacy(cSize, dBound, ERROR(srcSize_wrong));
+            return;
+        }
 
         ip += cBlockSize;
         remainingSize -= cBlockSize;
+        nbBlocks++;
     }
 
-    return ip - (const BYTE*)src;
+    *cSize = ip - (const BYTE*)src;
+    *dBound = nbBlocks * ZSTDv07_BLOCKSIZE_ABSOLUTEMAX;
 }
 
 /*_******************************

lib/legacy/zstd_v07.h

@@ -50,12 +50,17 @@ ZSTDLIBv07_API size_t ZSTDv07_decompress( void* dst, size_t dstCapacity,
                                     const void* src, size_t compressedSize);
 
 /**
-ZSTDv07_getFrameSrcSize() : get the source length of a ZSTD frame
+ZSTDv07_findFrameSizeInfoLegacy() : get the source length and decompressed bound of a ZSTD frame compliant with v0.7.x format
-    compressedSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
+    srcSize : The size of the 'src' buffer, at least as large as the frame pointed to by 'src'
-    return : the number of bytes that would be read to decompress this frame
+    cSize (output parameter)  : the number of bytes that would be read to decompress this frame
-             or an errorCode if it fails (which can be tested using ZSTDv07_isError())
+                                or an error code if it fails (which can be tested using ZSTDv01_isError())
+    dBound (output parameter) : an upper-bound for the decompressed size of the data in the frame
+                                or ZSTD_CONTENTSIZE_ERROR if an error occurs
+
+    note : assumes `cSize` and `dBound` are _not_ NULL.
 */
-size_t ZSTDv07_findFrameCompressedSize(const void* src, size_t compressedSize);
+void ZSTDv07_findFrameSizeInfoLegacy(const void *src, size_t srcSize,
+                                     size_t* cSize, unsigned long long* dBound);
 
 /*======  Helper functions  ======*/
 ZSTDLIBv07_API unsigned    ZSTDv07_isError(size_t code);          /*!< tells if a `size_t` function result is an error code */

lib/zstd.h

@@ -1115,7 +1115,7 @@ ZSTDLIB_API unsigned long long ZSTD_findDecompressedSize(const void* src, size_t
  *  @return : - upper-bound for the decompressed size of all data in all successive frames
  *            - if an error occured: ZSTD_CONTENTSIZE_ERROR
  *
- *  note 1  : an error can occur if `src` contains a legacy frame or an invalid/incorrectly formatted frame.
+ *  note 1  : an error can occur if `src` contains an invalid or incorrectly formatted frame.
  *  note 2  : the upper-bound is exact when the decompressed size field is available in every ZSTD encoded frame of `src`.
  *            in this case, `ZSTD_findDecompressedSize` and `ZSTD_decompressBound` return the same value.
  *  note 3  : when the decompressed size field isn't available, the upper-bound for that frame is calculated by:

tests/legacy.c

@@ -133,10 +133,27 @@ static int testStreamingAPI(void)
 
 static int testFrameDecoding(void)
 {
-    if (ZSTD_decompressBound(COMPRESSED, COMPRESSED_SIZE) != ZSTD_CONTENTSIZE_ERROR) {
+    if (strlen(EXPECTED) > ZSTD_decompressBound(COMPRESSED, COMPRESSED_SIZE)) {
-        DISPLAY("ERROR: ZSTD_decompressBound: Expected to receive ZSTD_CONTENTSIZE_ERROR\n");
+        DISPLAY("ERROR: ZSTD_decompressBound: decompressed bound too small\n");
         return 1;
     }
+    {   const char* ip = COMPRESSED;
+        size_t remainingSize = COMPRESSED_SIZE;
+        while (1) {
+            size_t frameSize = ZSTD_findFrameCompressedSize(ip, remainingSize);
+            if (ZSTD_isError(frameSize)) {
+                DISPLAY("ERROR: ZSTD_findFrameCompressedSize: %s\n", ZSTD_getErrorName(frameSize));
+                return 1;
+            }
+            if (frameSize > remainingSize) {
+                DISPLAY("ERROR: ZSTD_findFrameCompressedSize: expected frameSize to align with src buffer");
+                return 1;
+            }
+            ip += frameSize;
+            remainingSize -= frameSize;
+            if (remainingSize == 0) break;
+        }
+    }
     DISPLAY("Frame Decoding OK\n");
     return 0;
 }