Added HTTPResponseParser.

src/HTTPServer/CMakeLists.txt

@@ -9,11 +9,13 @@ SET (SRCS
 	HTTPFormParser.cpp
 	HTTPMessage.cpp
 	HTTPRequestParser.cpp
+	HTTPResponseParser.cpp
 	HTTPServer.cpp
 	HTTPServerConnection.cpp
 	MultipartParser.cpp
 	NameValueParser.cpp
 	SslHTTPServerConnection.cpp
+	TransferEncodingParser.cpp
 	UrlParser.cpp
 )
 
@@ -22,11 +24,13 @@ SET (HDRS
 	HTTPFormParser.h
 	HTTPMessage.h
 	HTTPRequestParser.h
+	HTTPResponseParser.h
 	HTTPServer.h
 	HTTPServerConnection.h
 	MultipartParser.h
 	NameValueParser.h
 	SslHTTPServerConnection.h
+	TransferEncodingParser.h
 	UrlParser.h
 )
 

src/HTTPServer/HTTPMessage.h

@@ -49,6 +49,7 @@ protected:
 
 	eKind m_Kind;
 
+	/** Map of headers, with their keys lowercased. */
 	AStringMap m_Headers;
 
 	/** Type of the content; parsed by AddHeader(), set directly by SetContentLength() */

src/HTTPServer/HTTPResponseParser.cpp

@@ -0,0 +1,177 @@
+
+// HTTPResponseParser.cpp
+
+// Implements the cHTTPResponseParser class representing the parser for incoming HTTP responses
+
+#include "Globals.h"
+#include "HTTPResponseParser.h"
+
+
+
+
+
+cHTTPResponseParser::cHTTPResponseParser(cHTTPResponseParser::cCallbacks & a_Callbacks):
+	Super(mkResponse),
+	m_Callbacks(a_Callbacks),
+	m_IsInHeaders(true),
+	m_IsFinished(false),
+	m_EnvelopeParser(*this)
+{
+}
+
+
+
+
+
+size_t cHTTPResponseParser::Parse(const char * a_Data, size_t a_Size)
+{
+	// If parsing already finished or errorred, let the caller keep all the data:
+	if (m_IsFinished || m_HasHadError)
+	{
+		return a_Size;
+	}
+
+	// If still waiting for the status line, add to buffer and try parsing it:
+	if (m_StatusLine.empty())
+	{
+		m_Buffer.append(a_Data, a_Size);
+		if (!ParseStatusLine())
+		{
+			// All data used, but not a complete status line yet.
+			return 0;
+		}
+		if (m_HasHadError)
+		{
+			return AString::npos;
+		}
+		// Status line completed, feed the rest of the buffer into the envelope parser:
+		auto bytesConsumed = m_EnvelopeParser.Parse(m_Buffer.data(), m_Buffer.size());
+		if (bytesConsumed == AString::npos)
+		{
+			m_HasHadError = true;
+			m_Callbacks.OnError("Failed to parse the envelope");
+			return AString::npos;
+		}
+		m_Buffer.erase(0, bytesConsumed);
+		if (!m_Buffer.empty())
+		{
+			// Headers finished and there's still data left in the buffer, process it as message body:
+			m_IsInHeaders = false;
+			return ParseBody(m_Buffer.data(), m_Buffer.size());
+		}
+		return 0;
+	}  // if (m_StatusLine.empty())
+
+	// If still parsing headers, send them to the envelope parser:
+	if (m_IsInHeaders)
+	{
+		auto bytesConsumed = m_EnvelopeParser.Parse(a_Data, a_Size);
+		if (bytesConsumed == AString::npos)
+		{
+			m_HasHadError = true;
+			m_Callbacks.OnError("Failed to parse the envelope");
+			return AString::npos;
+		}
+		if (bytesConsumed < a_Size)
+		{
+			// Headers finished and there's still data left in the buffer, process it as message body:
+			HeadersFinished();
+			return ParseBody(a_Data + bytesConsumed, a_Size - bytesConsumed);
+		}
+		return 0;
+	}
+
+	// Already parsing the body
+	return ParseBody(a_Data, a_Size);
+}
+
+
+
+
+
+bool cHTTPResponseParser::ParseStatusLine(void)
+{
+	auto idxLineEnd = m_Buffer.find("\r\n");
+	if (idxLineEnd == AString::npos)
+	{
+		// Not a complete line yet
+		return false;
+	}
+	m_StatusLine = m_Buffer.substr(0, idxLineEnd);
+	m_Buffer.erase(0, idxLineEnd + 2);
+	m_Callbacks.OnStatusLine(m_StatusLine);
+	return true;
+}
+
+
+
+
+size_t cHTTPResponseParser::ParseBody(const char * a_Data, size_t a_Size)
+{
+	if (m_TransferEncodingParser == nullptr)
+	{
+		// We have no Transfer-encoding parser assigned. This should have happened when finishing the envelope
+		return AString::npos;
+	}
+
+	// Parse the body using the transfer encoding parser:
+	return m_TransferEncodingParser->Parse(a_Data, a_Size);
+}
+
+
+
+
+
+void cHTTPResponseParser::HeadersFinished(void)
+{
+	m_IsInHeaders = false;
+	m_Callbacks.OnHeadersFinished();
+
+	auto transferEncoding = m_Headers.find("transfer-encoding");
+	if (transferEncoding == m_Headers.end())
+	{
+		m_TransferEncodingParser = cTransferEncodingParser::Create(*this, "identity", m_ContentLength);
+	}
+}
+
+
+
+
+
+void cHTTPResponseParser::OnHeaderLine(const AString & a_Key, const AString & a_Value)
+{
+	AddHeader(a_Key, a_Value);
+	m_Callbacks.OnHeaderLine(a_Key, a_Value);
+}
+
+
+
+
+
+void cHTTPResponseParser::OnError(const AString & a_ErrorDescription)
+{
+	m_HasHadError = true;
+	m_Callbacks.OnError(a_ErrorDescription);
+}
+
+
+
+
+
+void cHTTPResponseParser::OnBodyData(const void * a_Data, size_t a_Size)
+{
+	m_Callbacks.OnBodyData(a_Data, a_Size);
+}
+
+
+
+
+
+void cHTTPResponseParser::OnBodyFinished(void)
+{
+	m_Callbacks.OnBodyFinished();
+}
+
+
+
+

src/HTTPServer/HTTPResponseParser.h

@@ -0,0 +1,118 @@
+
+// HTTPResponseParser.h
+
+// Declares the cHTTPResponseParser class representing the parser for incoming HTTP responses
+
+
+
+
+#pragma once
+
+#include "HTTPMessage.h"
+#include "TransferEncodingParser.h"
+
+
+
+
+
+class cHTTPResponseParser:
+	public cHTTPMessage,
+	protected cEnvelopeParser::cCallbacks,
+	protected cTransferEncodingParser::cCallbacks
+{
+	typedef cHTTPMessage Super;
+
+public:
+	class cCallbacks
+	{
+	public:
+		// Force a virtual destructor in descendants:
+		virtual ~cCallbacks() {}
+
+		/** Called when an error has occured while parsing. */
+		virtual void OnError(const AString & a_ErrorDescription) = 0;
+
+		/** Called when the status line is fully parsed. */
+		virtual void OnStatusLine(const AString & a_StatusLine) = 0;
+
+		/** Called when a single header line is parsed. */
+		virtual void OnHeaderLine(const AString & a_Key, const AString & a_Value) = 0;
+
+		/** Called when all the headers have been parsed. */
+		virtual void OnHeadersFinished(void) = 0;
+
+		/** Called for each chunk of the incoming body data. */
+		virtual void OnBodyData(const void * a_Data, size_t a_Size) = 0;
+
+		/** Called when the entire body has been reported by OnBodyData(). */
+		virtual void OnBodyFinished(void) = 0;
+	};
+
+	cHTTPResponseParser(cCallbacks & a_Callbacks);
+
+	/** Parses the incoming data and calls the appropriate callbacks.
+	Returns the number of bytes from the end of a_Data that is already not part of this response.
+	Returns AString::npos on an error. */
+	size_t Parse(const char * a_Data, size_t a_Size);
+
+	/** Called when the server indicates no more data will be sent (HTTP 1.0 socket closed).
+	Finishes all parsing and calls apropriate callbacks (error if incomplete response). */
+	void Finish(void);
+
+	/** Returns true if the entire response has been already parsed. */
+	bool IsFinished(void) const { return m_IsFinished; }
+
+
+protected:
+
+	/** The callbacks used for reporting. */
+	cCallbacks & m_Callbacks;
+
+	/** Set to true if an error has been encountered by the parser. */
+	bool m_HasHadError;
+
+	/** True if the parser is still parsing the status or headers. */
+	bool m_IsInHeaders;
+
+	/** True if the response has been fully parsed. */
+	bool m_IsFinished;
+
+	/** The complete status line of the response. Empty if not parsed yet. */
+	AString m_StatusLine;
+
+	/** Buffer for the incoming data until the status line is parsed. */
+	AString m_Buffer;
+
+	/** Parser for the envelope data (headers) */
+	cEnvelopeParser m_EnvelopeParser;
+
+	/** The specific parser for the transfer encoding used by this response. */
+	cTransferEncodingParserPtr m_TransferEncodingParser;
+
+
+	/** Parses the status line out of the m_Buffer.
+	Removes the status line from m_Buffer, if appropriate.
+	Returns true if the entire status line has been parsed. */
+	bool ParseStatusLine(void);
+
+	/** Parses the message body.
+	Processes transfer encoding and calls the callbacks for body data.
+	Returns the number of bytes from the end of a_Data that is already not part of this response.
+	Returns AString::npos on error. */
+	size_t ParseBody(const char * a_Data, size_t a_Size);
+
+	/** Called internally when the headers-parsing has just finished. */
+	void HeadersFinished(void);
+
+	// cEnvelopeParser::cCallbacks overrides:
+	virtual void OnHeaderLine(const AString & a_Key, const AString & a_Value) override;
+
+	// cTransferEncodingParser::cCallbacks overrides:
+	virtual void OnError(const AString & a_ErrorDescription) override;
+	virtual void OnBodyData(const void * a_Data, size_t a_Size) override;
+	virtual void OnBodyFinished(void) override;
+};
+
+
+
+

src/HTTPServer/TransferEncodingParser.cpp

@@ -0,0 +1,132 @@
+
+// TransferEncodingParser.cpp
+
+// Implements the cTransferEncodingParser class and its descendants representing the parser for the various transfer encodings (chunked etc.)
+
+#include "Globals.h"
+#include "TransferEncodingParser.h"
+
+
+
+
+
+////////////////////////////////////////////////////////////////////////////////
+// cChunkedTEParser:
+
+class cChunkedTEParser:
+	public cTransferEncodingParser
+{
+	typedef cTransferEncodingParser Super;
+
+public:
+	cChunkedTEParser(cCallbacks & a_Callbacks):
+		Super(a_Callbacks),
+		m_IsFinished(false)
+	{
+	}
+
+
+protected:
+
+	/** True if the datastream has finished (zero-length chunk received). */
+	bool m_IsFinished;
+
+
+	// cTransferEncodingParser overrides:
+	virtual size_t Parse(const char * a_Data, size_t a_Size) override
+	{
+		// TODO
+		m_Callbacks.OnError("cChunkedTEParser not implemented yet");
+		return AString::npos;
+	}
+
+	virtual void Finish(void) override
+	{
+		if (!m_IsFinished)
+		{
+			m_Callbacks.OnError("ChunkedTransferEncoding: Finish signal received before the data stream ended");
+		}
+		m_IsFinished = true;
+	}
+};
+
+
+
+
+
+////////////////////////////////////////////////////////////////////////////////
+// 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.empty())
+	{
+		return std::make_shared<cIdentityTEParser>(a_Callbacks, a_ContentLength);
+	}
+	return nullptr;
+}
+
+
+
+

src/HTTPServer/TransferEncodingParser.h

@@ -0,0 +1,76 @@
+
+// TransferEncodingParser.h
+
+// Declares the cTransferEncodingParser class representing the parser for the various transfer encodings (chunked etc.)
+
+#pragma once
+
+
+
+
+
+// fwd:
+class cTransferEncodingParser;
+typedef SharedPtr<cTransferEncodingParser> cTransferEncodingParserPtr;
+
+
+
+
+
+/** Used as both the interface that all the parsers share and the (static) factory creating such parsers. */
+class cTransferEncodingParser
+{
+public:
+	class cCallbacks
+	{
+	public:
+		// Force a virtual destructor in descendants
+		virtual ~cCallbacks() {}
+
+		/** Called when an error has occured while parsing. */
+		virtual void OnError(const AString & a_ErrorDescription) = 0;
+
+		/** Called for each chunk of the incoming body data. */
+		virtual void OnBodyData(const void * a_Data, size_t a_Size) = 0;
+
+		/** Called when the entire body has been reported by OnBodyData(). */
+		virtual void OnBodyFinished(void) = 0;
+	};
+
+
+	// Force a virtual destructor in all descendants
+	virtual ~cTransferEncodingParser() {}
+
+	/** Parses the incoming data and calls the appropriate callbacks.
+	Returns the number of bytes from the end of a_Data that is already not part of this message (if the parser can detect it).
+	Returns AString::npos on an error. */
+	virtual size_t Parse(const char * a_Data, size_t a_Size) = 0;
+
+	/** To be called when the stream is terminated from the source (connection closed).
+	Flushes any buffers and calls appropriate callbacks. */
+	virtual void Finish(void) = 0;
+
+	/** Creates a new parser for the specified encoding.
+	If the encoding is not known, returns a nullptr.
+	a_ContentLength is the length of the content, received in a Content-Length header.
+	It is used for the Identity encoding, it is ignored for the Chunked encoding. */
+	static cTransferEncodingParserPtr Create(
+		cCallbacks & a_Callbacks,
+		const AString & a_TransferEncoding,
+		size_t a_ContentLength
+	);
+
+protected:
+	/** The callbacks used to report progress. */
+	cCallbacks & m_Callbacks;
+
+
+	cTransferEncodingParser(cCallbacks & a_Callbacks):
+		m_Callbacks(a_Callbacks)
+	{
+	}
+};
+
+
+
+