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author | dkf <donal.k.fellows@manchester.ac.uk> | 2016-10-30 05:04:54 (GMT) |
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committer | dkf <donal.k.fellows@manchester.ac.uk> | 2016-10-30 05:04:54 (GMT) |
commit | 51bce8152fb964591bf095135d365d1586291d1c (patch) | |
tree | 9d27d22acc9a7d60cc5027c06c5ae8eaa4eab310 /generic/tclZlib.c | |
parent | 597d65b1e9b9c0c40782bc5ee8b372bf4bb6b995 (diff) | |
parent | f50fc619a4f614dc4011b6bf50add8f947d6cb35 (diff) | |
download | tcl-51bce8152fb964591bf095135d365d1586291d1c.zip tcl-51bce8152fb964591bf095135d365d1586291d1c.tar.gz tcl-51bce8152fb964591bf095135d365d1586291d1c.tar.bz2 |
[b26e38a3e4] Ensure that compressing streams manage buffers correctly in all cases.
Diffstat (limited to 'generic/tclZlib.c')
-rw-r--r-- | generic/tclZlib.c | 144 |
1 files changed, 86 insertions, 58 deletions
diff --git a/generic/tclZlib.c b/generic/tclZlib.c index c9d7b88..53cd14b 100644 --- a/generic/tclZlib.c +++ b/generic/tclZlib.c @@ -177,6 +177,8 @@ static Tcl_ObjCmdProc ZlibStreamPutCmd; static void ConvertError(Tcl_Interp *interp, int code, uLong adler); static Tcl_Obj * ConvertErrorToList(int code, uLong adler); +static inline int Deflate(z_streamp strm, void *bufferPtr, + int bufferSize, int flush, int *writtenPtr); static void ExtractHeader(gz_header *headerPtr, Tcl_Obj *dictObj); static int GenerateHeader(Tcl_Interp *interp, Tcl_Obj *dictObj, GzipHeader *headerPtr, int *extraSizePtr); @@ -578,6 +580,10 @@ ExtractHeader( } } +/* + * Disentangle the worst of how the zlib API is used. + */ + static int SetInflateDictionary( z_streamp strm, @@ -605,6 +611,38 @@ SetDeflateDictionary( } return Z_OK; } + +static inline int +Deflate( + z_streamp strm, + void *bufferPtr, + int bufferSize, + int flush, + int *writtenPtr) +{ + int e; + + strm->next_out = (Bytef *) bufferPtr; + strm->avail_out = (unsigned) bufferSize; + e = deflate(strm, flush); + if (writtenPtr != NULL) { + *writtenPtr = bufferSize - strm->avail_out; + } + return e; +} + +static inline void +AppendByteArray( + Tcl_Obj *listObj, + void *buffer, + int size) +{ + if (size > 0) { + Tcl_Obj *baObj = Tcl_NewByteArrayObj((unsigned char *) buffer, size); + + Tcl_ListObjAppendElement(NULL, listObj, baObj); + } +} /* *---------------------------------------------------------------------- @@ -1139,6 +1177,8 @@ Tcl_ZlibStreamSetCompressionDictionary( *---------------------------------------------------------------------- */ +#define BUFFER_SIZE_LIMIT 0xFFFF + int Tcl_ZlibStreamPut( Tcl_ZlibStream zshandle, /* As obtained from Tcl_ZlibStreamInit */ @@ -1148,8 +1188,7 @@ Tcl_ZlibStreamPut( { ZlibStreamHandle *zshPtr = (ZlibStreamHandle *) zshandle; char *dataTmp = NULL; - int e, size, outSize; - Tcl_Obj *obj; + int e, size, outSize, toStore; if (zshPtr->streamEnd) { if (zshPtr->interp) { @@ -1175,26 +1214,45 @@ Tcl_ZlibStreamPut( if (HaveDictToSet(zshPtr)) { e = SetDeflateDictionary(&zshPtr->stream, zshPtr->compDictObj); if (e != Z_OK) { - if (zshPtr->interp) { - ConvertError(zshPtr->interp, e, zshPtr->stream.adler); - } + ConvertError(zshPtr->interp, e, zshPtr->stream.adler); return TCL_ERROR; } DictWasSet(zshPtr); } /* - * Deflatebound doesn't seem to take various header sizes into - * account, so we add 100 extra bytes. + * deflateBound() doesn't seem to take various header sizes into + * account, so we add 100 extra bytes. However, we can also loop + * around again so we also set an upper bound on the output buffer + * size. */ - outSize = deflateBound(&zshPtr->stream, zshPtr->stream.avail_in)+100; - zshPtr->stream.avail_out = outSize; - dataTmp = ckalloc(zshPtr->stream.avail_out); - zshPtr->stream.next_out = (Bytef *) dataTmp; + outSize = deflateBound(&zshPtr->stream, size) + 100; + if (outSize > BUFFER_SIZE_LIMIT) { + outSize = BUFFER_SIZE_LIMIT; + } + dataTmp = ckalloc(outSize); + + while (1) { + e = Deflate(&zshPtr->stream, dataTmp, outSize, flush, &toStore); + + /* + * Test if we've filled the buffer up and have to ask deflate() to + * give us some more. Note that the condition for needing to + * repeat a buffer transfer when the result is Z_OK is whether + * there is no more space in the buffer we provided; the zlib + * library does not necessarily return a different code in that + * case. [Bug b26e38a3e4] [Tk Bug 10f2e7872b] + */ + + if ((e != Z_BUF_ERROR) && (e != Z_OK || toStore < outSize)) { + if ((e == Z_OK) || (flush == Z_FINISH && e == Z_STREAM_END)) { + break; + } + ConvertError(zshPtr->interp, e, zshPtr->stream.adler); + return TCL_ERROR; + } - e = deflate(&zshPtr->stream, flush); - while (e == Z_BUF_ERROR || (flush == Z_FINISH && e == Z_OK)) { /* * Output buffer too small to hold the data being generated or we * are doing the end-of-stream flush (which can spit out masses of @@ -1202,45 +1260,21 @@ Tcl_ZlibStreamPut( * saving the old generated data to the outData list. */ - obj = Tcl_NewByteArrayObj((unsigned char *) dataTmp, outSize); - Tcl_ListObjAppendElement(NULL, zshPtr->outData, obj); + AppendByteArray(zshPtr->outData, dataTmp, outSize); - if (outSize < 0xFFFF) { - outSize = 0xFFFF; /* There may be *lots* of data left to - * output... */ + if (outSize < BUFFER_SIZE_LIMIT) { + outSize = BUFFER_SIZE_LIMIT; + /* There may be *lots* of data left to output... */ dataTmp = ckrealloc(dataTmp, outSize); } - zshPtr->stream.avail_out = outSize; - zshPtr->stream.next_out = (Bytef *) dataTmp; - - e = deflate(&zshPtr->stream, flush); - } - - if (e != Z_OK && !(flush==Z_FINISH && e==Z_STREAM_END)) { - if (zshPtr->interp) { - ConvertError(zshPtr->interp, e, zshPtr->stream.adler); - } - return TCL_ERROR; } /* - * And append the final data block. + * And append the final data block to the outData list. */ - if (outSize - zshPtr->stream.avail_out > 0) { - obj = Tcl_NewByteArrayObj((unsigned char *) dataTmp, - outSize - zshPtr->stream.avail_out); - - /* - * Now append the compressed data to the outData list. - */ - - Tcl_ListObjAppendElement(NULL, zshPtr->outData, obj); - } - - if (dataTmp) { - ckfree(dataTmp); - } + AppendByteArray(zshPtr->outData, dataTmp, toStore); + ckfree(dataTmp); } else { /* * This is easy. Just append to the inData list. @@ -1356,9 +1390,7 @@ Tcl_ZlibStreamGet( if (IsRawStream(zshPtr) && HaveDictToSet(zshPtr)) { e = SetInflateDictionary(&zshPtr->stream, zshPtr->compDictObj); if (e != Z_OK) { - if (zshPtr->interp) { - ConvertError(zshPtr->interp, e, zshPtr->stream.adler); - } + ConvertError(zshPtr->interp, e, zshPtr->stream.adler); return TCL_ERROR; } DictWasSet(zshPtr); @@ -2879,10 +2911,8 @@ ZlibTransformClose( if (cd->mode == TCL_ZLIB_STREAM_DEFLATE) { cd->outStream.avail_in = 0; do { - cd->outStream.next_out = (Bytef *) cd->outBuffer; - cd->outStream.avail_out = (unsigned) cd->outAllocated; - e = deflate(&cd->outStream, Z_FINISH); - written = cd->outAllocated - cd->outStream.avail_out; + e = Deflate(&cd->outStream, cd->outBuffer, cd->outAllocated, + Z_FINISH, &written); /* * Can't be sure that deflate() won't declare the buffer to be @@ -3086,17 +3116,15 @@ ZlibTransformOutput( cd->outStream.next_in = (Bytef *) buf; cd->outStream.avail_in = toWrite; do { - cd->outStream.next_out = (Bytef *) cd->outBuffer; - cd->outStream.avail_out = cd->outAllocated; - - e = deflate(&cd->outStream, Z_NO_FLUSH); - produced = cd->outAllocated - cd->outStream.avail_out; + e = Deflate(&cd->outStream, cd->outBuffer, cd->outAllocated, + Z_NO_FLUSH, &produced); if ((e == Z_OK && produced > 0) || e == Z_BUF_ERROR) { /* * deflate() indicates that it is out of space by returning - * Z_BUF_ERROR; in that case, we must write the whole buffer out - * and retry to compress what is left. + * Z_BUF_ERROR *or* by simply returning Z_OK with no remaining + * space; in either case, we must write the whole buffer out and + * retry to compress what is left. */ if (e == Z_BUF_ERROR) { |