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author | Mattes D <github@xoft.cz> | 2016-03-01 16:58:43 +0100 |
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committer | Mattes D <github@xoft.cz> | 2016-03-01 16:58:43 +0100 |
commit | 7cc8f8dd2213cade66633d196f579895385a869a (patch) | |
tree | 83219a6eaf87a2050c10662fb8caa5d1514a6af4 /src/HTTP/TransferEncodingParser.cpp | |
parent | Merge pull request #3057 from tonibm19/master (diff) | |
parent | HTTP: Fixed typos and bad leftovers. (diff) | |
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Diffstat (limited to 'src/HTTP/TransferEncodingParser.cpp')
-rw-r--r-- | src/HTTP/TransferEncodingParser.cpp | 394 |
1 files changed, 394 insertions, 0 deletions
diff --git a/src/HTTP/TransferEncodingParser.cpp b/src/HTTP/TransferEncodingParser.cpp new file mode 100644 index 000000000..a14900e9c --- /dev/null +++ b/src/HTTP/TransferEncodingParser.cpp @@ -0,0 +1,394 @@ + +// TransferEncodingParser.cpp + +// Implements the cTransferEncodingParser class and its descendants representing the parsers for the various transfer encodings (chunked etc.) + +#include "Globals.h" +#include "TransferEncodingParser.h" +#include "EnvelopeParser.h" + + + + + +//////////////////////////////////////////////////////////////////////////////// +// cChunkedTEParser: + +class cChunkedTEParser: + public cTransferEncodingParser, + public cEnvelopeParser::cCallbacks +{ + typedef cTransferEncodingParser Super; + +public: + cChunkedTEParser(Super::cCallbacks & a_Callbacks): + Super(a_Callbacks), + m_State(psChunkLength), + m_ChunkDataLengthLeft(0), + m_TrailerParser(*this) + { + } + + +protected: + enum eState + { + psChunkLength, ///< Parsing the chunk length hex number + psChunkLengthTrailer, ///< Any trailer (chunk extension) specified after the chunk length + psChunkLengthLF, ///< The LF character after the CR character terminating the chunk length + psChunkData, ///< Relaying chunk data + psChunkDataCR, ///< Skipping the extra CR character after chunk data + psChunkDataLF, ///< Skipping the extra LF character after chunk data + psTrailer, ///< Received an empty chunk, parsing the trailer (through the envelope parser) + psFinished, ///< The parser has finished parsing, either successfully or with an error + }; + + /** The current state of the parser (parsing chunk length / chunk data). */ + eState m_State; + + /** Number of bytes that still belong to the chunk currently being parsed. + When in psChunkLength, the value is the currently parsed length digits. */ + size_t m_ChunkDataLengthLeft; + + /** The parser used for the last (empty) chunk's trailer data */ + cEnvelopeParser m_TrailerParser; + + + /** Calls the OnError callback and sets parser state to finished. */ + void Error(const AString & a_ErrorMsg) + { + m_State = psFinished; + m_Callbacks.OnError(a_ErrorMsg); + } + + + /** Parses the incoming data, the current state is psChunkLength. + Stops parsing when either the chunk length has been read, or there is no more data in the input. + Returns the number of bytes consumed from the input, or AString::npos on error (calls the Error handler). */ + size_t ParseChunkLength(const char * a_Data, size_t a_Size) + { + // Expected input: <hexnumber>[;<trailer>]<CR><LF> + // Only the hexnumber is parsed into m_ChunkDataLengthLeft, the rest is postponed into psChunkLengthTrailer or psChunkLengthLF + for (size_t i = 0; i < a_Size; i++) + { + switch (a_Data[i]) + { + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + { + m_ChunkDataLengthLeft = m_ChunkDataLengthLeft * 16 + static_cast<decltype(m_ChunkDataLengthLeft)>(a_Data[i] - '0'); + break; + } + case 'a': + case 'b': + case 'c': + case 'd': + case 'e': + case 'f': + { + m_ChunkDataLengthLeft = m_ChunkDataLengthLeft * 16 + static_cast<decltype(m_ChunkDataLengthLeft)>(a_Data[i] - 'a' + 10); + break; + } + case 'A': + case 'B': + case 'C': + case 'D': + case 'E': + case 'F': + { + m_ChunkDataLengthLeft = m_ChunkDataLengthLeft * 16 + static_cast<decltype(m_ChunkDataLengthLeft)>(a_Data[i] - 'A' + 10); + break; + } + case '\r': + { + m_State = psChunkLengthLF; + return i + 1; + } + case ';': + { + m_State = psChunkLengthTrailer; + return i + 1; + } + default: + { + Error(Printf("Invalid character in chunk length line: 0x%x", a_Data[i])); + return AString::npos; + } + } // switch (a_Data[i]) + } // for i - a_Data[] + return a_Size; + } + + + /** Parses the incoming data, the current state is psChunkLengthTrailer. + Stops parsing when either the chunk length trailer has been read, or there is no more data in the input. + Returns the number of bytes consumed from the input, or AString::npos on error (calls the Error handler). */ + size_t ParseChunkLengthTrailer(const char * a_Data, size_t a_Size) + { + // Expected input: <trailer><CR><LF> + // The LF itself is not parsed, it is instead postponed into psChunkLengthLF + for (size_t i = 0; i < a_Size; i++) + { + switch (a_Data[i]) + { + case '\r': + { + m_State = psChunkLengthLF; + return i; + } + default: + { + if (a_Data[i] < 32) + { + // Only printable characters are allowed in the trailer + Error(Printf("Invalid character in chunk length line: 0x%x", a_Data[i])); + return AString::npos; + } + } + } // switch (a_Data[i]) + } // for i - a_Data[] + return a_Size; + } + + + /** Parses the incoming data, the current state is psChunkLengthLF. + Only the LF character is expected, if found, moves to psChunkData, otherwise issues an error. + If the chunk length that just finished reading is equal to 0, signals the end of stream (via psTrailer). + Returns the number of bytes consumed from the input, or AString::npos on error (calls the Error handler). */ + size_t ParseChunkLengthLF(const char * a_Data, size_t a_Size) + { + // Expected input: <LF> + if (a_Size == 0) + { + return 0; + } + if (a_Data[0] == '\n') + { + if (m_ChunkDataLengthLeft == 0) + { + m_State = psTrailer; + } + else + { + m_State = psChunkData; + } + return 1; + } + Error(Printf("Invalid character past chunk length's CR: 0x%x", a_Data[0])); + return AString::npos; + } + + + /** Consumes as much chunk data from the input as possible. + Returns the number of bytes consumed from the input, or AString::npos on error (calls the Error() handler). */ + size_t ParseChunkData(const char * a_Data, size_t a_Size) + { + ASSERT(m_ChunkDataLengthLeft > 0); + auto bytes = std::min(a_Size, m_ChunkDataLengthLeft); + m_ChunkDataLengthLeft -= bytes; + m_Callbacks.OnBodyData(a_Data, bytes); + if (m_ChunkDataLengthLeft == 0) + { + m_State = psChunkDataCR; + } + return bytes; + } + + + /** Parses the incoming data, the current state is psChunkDataCR. + Only the CR character is expected, if found, moves to psChunkDataLF, otherwise issues an error. + Returns the number of bytes consumed from the input, or AString::npos on error (calls the Error handler). */ + size_t ParseChunkDataCR(const char * a_Data, size_t a_Size) + { + // Expected input: <CR> + if (a_Size == 0) + { + return 0; + } + if (a_Data[0] == '\r') + { + m_State = psChunkDataLF; + return 1; + } + Error(Printf("Invalid character past chunk data: 0x%x", a_Data[0])); + return AString::npos; + } + + + + + /** Parses the incoming data, the current state is psChunkDataCR. + Only the CR character is expected, if found, moves to psChunkDataLF, otherwise issues an error. + Returns the number of bytes consumed from the input, or AString::npos on error (calls the Error handler). */ + size_t ParseChunkDataLF(const char * a_Data, size_t a_Size) + { + // Expected input: <LF> + if (a_Size == 0) + { + return 0; + } + if (a_Data[0] == '\n') + { + m_State = psChunkLength; + return 1; + } + Error(Printf("Invalid character past chunk data's CR: 0x%x", a_Data[0])); + return AString::npos; + } + + + /** Parses the incoming data, the current state is psChunkDataCR. + The trailer is normally a set of "Header: Value" lines, terminated by an empty line. Use the m_TrailerParser for that. + Returns the number of bytes consumed from the input, or AString::npos on error (calls the Error handler). */ + size_t ParseTrailer(const char * a_Data, size_t a_Size) + { + auto res = m_TrailerParser.Parse(a_Data, a_Size); + if (res == AString::npos) + { + Error("Error while parsing the trailer"); + } + if ((res < a_Size) || !m_TrailerParser.IsInHeaders()) + { + m_Callbacks.OnBodyFinished(); + m_State = psFinished; + } + return res; + } + + + // cTransferEncodingParser overrides: + virtual size_t Parse(const char * a_Data, size_t a_Size) override + { + while ((a_Size > 0) && (m_State != psFinished)) + { + size_t consumed = 0; + switch (m_State) + { + case psChunkLength: consumed = ParseChunkLength (a_Data, a_Size); break; + case psChunkLengthTrailer: consumed = ParseChunkLengthTrailer(a_Data, a_Size); break; + case psChunkLengthLF: consumed = ParseChunkLengthLF (a_Data, a_Size); break; + case psChunkData: consumed = ParseChunkData (a_Data, a_Size); break; + case psChunkDataCR: consumed = ParseChunkDataCR (a_Data, a_Size); break; + case psChunkDataLF: consumed = ParseChunkDataLF (a_Data, a_Size); break; + case psTrailer: consumed = ParseTrailer (a_Data, a_Size); break; + case psFinished: consumed = 0; break; // Not supposed to happen, but Clang complains without it + } + if (consumed == AString::npos) + { + return AString::npos; + } + a_Data += consumed; + a_Size -= consumed; + } + return a_Size; + } + + virtual void Finish(void) override + { + if (m_State != psFinished) + { + Error(Printf("ChunkedTransferEncoding: Finish signal received before the data stream ended (state: %d)", m_State)); + } + m_State = psFinished; + } + + + // cEnvelopeParser::cCallbacks overrides: + virtual void OnHeaderLine(const AString & a_Key, const AString & a_Value) override + { + // Ignored + } +}; + + + + + +//////////////////////////////////////////////////////////////////////////////// +// cIdentityTEParser: + +class cIdentityTEParser: + public cTransferEncodingParser +{ + typedef cTransferEncodingParser Super; + +public: + cIdentityTEParser(cCallbacks & a_Callbacks, size_t a_ContentLength): + Super(a_Callbacks), + m_BytesLeft(a_ContentLength) + { + } + + +protected: + /** How many bytes of content are left before the message ends. */ + size_t m_BytesLeft; + + // cTransferEncodingParser overrides: + virtual size_t Parse(const char * a_Data, size_t a_Size) override + { + auto size = std::min(a_Size, m_BytesLeft); + if (size > 0) + { + m_Callbacks.OnBodyData(a_Data, size); + } + m_BytesLeft -= size; + if (m_BytesLeft == 0) + { + m_Callbacks.OnBodyFinished(); + } + return a_Size - size; + } + + virtual void Finish(void) override + { + if (m_BytesLeft > 0) + { + m_Callbacks.OnError("IdentityTransferEncoding: body was truncated"); + } + else + { + // BodyFinished has already been called, just bail out + } + } +}; + + + + + +//////////////////////////////////////////////////////////////////////////////// +// cTransferEncodingParser: + +cTransferEncodingParserPtr cTransferEncodingParser::Create( + cCallbacks & a_Callbacks, + const AString & a_TransferEncoding, + size_t a_ContentLength +) +{ + if (a_TransferEncoding == "chunked") + { + return std::make_shared<cChunkedTEParser>(a_Callbacks); + } + if (a_TransferEncoding == "identity") + { + return std::make_shared<cIdentityTEParser>(a_Callbacks, a_ContentLength); + } + if (a_TransferEncoding.empty()) + { + return std::make_shared<cIdentityTEParser>(a_Callbacks, a_ContentLength); + } + return nullptr; +} + + + + |