libpion-net-dev 4.0.7+dfsg-3.1ubuntu4 / usr / include / pion / net / HTTPParser.hpp

// ------------------------------------------------------------------
// pion-net: a C++ framework for building lightweight HTTP interfaces
// ------------------------------------------------------------------
// Copyright (C) 2007-2008 Atomic Labs, Inc.  (http://www.atomiclabs.com)
//
// Distributed under the Boost Software License, Version 1.0.
// See http://www.boost.org/LICENSE_1_0.txt
//

#ifndef __PION_HTTPPARSER_HEADER__
#define __PION_HTTPPARSER_HEADER__

#include <string>
#include <boost/noncopyable.hpp>
#include <boost/logic/tribool.hpp>
#include <boost/system/error_code.hpp>
#include <boost/thread/once.hpp>
#include <pion/PionConfig.hpp>
#include <pion/PionLogger.hpp>
#include <pion/net/HTTPMessage.hpp>


namespace pion {	// begin namespace pion
namespace net {		// begin namespace net (Pion Network Library)

// forward declarations used for finishing HTTP messages
class HTTPRequest;
class HTTPResponse;

///
/// HTTPParser: parses HTTP messages
///
class PION_NET_API HTTPParser :
	private boost::noncopyable
{

public:

	/// maximum length for HTTP payload content
	static const std::size_t		DEFAULT_CONTENT_MAX;

	/// class-specific error code values
	enum ErrorValue {
		ERROR_METHOD_CHAR = 1,
		ERROR_METHOD_SIZE,
		ERROR_URI_CHAR,
		ERROR_URI_SIZE,
		ERROR_QUERY_CHAR,
		ERROR_QUERY_SIZE,
		ERROR_VERSION_EMPTY,
		ERROR_VERSION_CHAR,
		ERROR_STATUS_EMPTY,
		ERROR_STATUS_CHAR,
		ERROR_HEADER_CHAR,
		ERROR_HEADER_NAME_SIZE,
		ERROR_HEADER_VALUE_SIZE,
		ERROR_INVALID_CONTENT_LENGTH,
		ERROR_CHUNK_CHAR,
		ERROR_MISSING_CHUNK_DATA,
		ERROR_MISSING_HEADER_DATA,
		ERROR_MISSING_TOO_MUCH_CONTENT,
	};
	
	/// class-specific error category
	class ErrorCategory
		: public boost::system::error_category
	{
	public:
		const char *name() const { return "HTTPParser"; }
		std::string message(int ev) const {
			switch (ev) {
			case ERROR_METHOD_CHAR:
				return "invalid method character";
			case ERROR_METHOD_SIZE:
				return "method exceeds maximum size";
			case ERROR_URI_CHAR:
				return "invalid URI character";
			case ERROR_URI_SIZE:
				return "method exceeds maximum size";
			case ERROR_QUERY_CHAR:
				return "invalid query string character";
			case ERROR_QUERY_SIZE:
				return "query string exceeds maximum size";
			case ERROR_VERSION_EMPTY:
				return "HTTP version undefined";
			case ERROR_VERSION_CHAR:
				return "invalid version character";
			case ERROR_STATUS_EMPTY:
				return "HTTP status undefined";
			case ERROR_STATUS_CHAR:
				return "invalid status character";
			case ERROR_HEADER_CHAR:
				return "invalid header character";
			case ERROR_HEADER_NAME_SIZE:
				return "header name exceeds maximum size";
			case ERROR_HEADER_VALUE_SIZE:
				return "header value exceeds maximum size";
			case ERROR_INVALID_CONTENT_LENGTH:
				return "invalid Content-Length header";
			case ERROR_CHUNK_CHAR:
				return "invalid chunk character";
			case ERROR_MISSING_HEADER_DATA:
				return "missing header data";
			case ERROR_MISSING_CHUNK_DATA:
				return "missing chunk data";
			case ERROR_MISSING_TOO_MUCH_CONTENT:
				return "missing too much content";
			}
			return "HTTPParser error";
		}
	};

	/**
	 * creates new HTTPParser objects
	 *
	 * @param is_request if true, the message is parsed as an HTTP request;
	 *                   if false, the message is parsed as an HTTP response
	 * @param max_content_length maximum length for HTTP payload content
	 */
	HTTPParser(const bool is_request, std::size_t max_content_length = DEFAULT_CONTENT_MAX)
		: m_logger(PION_GET_LOGGER("pion.net.HTTPParser")), m_is_request(is_request),
		m_read_ptr(NULL), m_read_end_ptr(NULL), m_message_parse_state(PARSE_START),
		m_headers_parse_state(is_request ? PARSE_METHOD_START : PARSE_HTTP_VERSION_H),
		m_chunked_content_parse_state(PARSE_CHUNK_SIZE_START), m_status_code(0),
		m_bytes_content_remaining(0), m_bytes_content_read(0),
		m_bytes_last_read(0), m_bytes_total_read(0),
		m_max_content_length(max_content_length),
		m_parse_headers_only(false), m_save_raw_headers(false)
	{}

	/// default destructor
	virtual ~HTTPParser() {}

	/**
	 * parses an HTTP message including all payload content it might contain
	 *
	 * @param http_msg the HTTP message object to populate from parsing
	 * @param ec error_code contains additional information for parsing errors
	 *
	 * @return boost::tribool result of parsing:
	 *                        false = message has an error,
	 *                        true = finished parsing HTTP message,
	 *                        indeterminate = not yet finished parsing HTTP message
	 */
	boost::tribool parse(HTTPMessage& http_msg, boost::system::error_code& ec);

	/**
	 * attempts to continue parsing despite having missed data (length is known but content is not)
	 *
	 * @param http_msg the HTTP message object to populate from parsing
	 * @param len the length in bytes of the missing data
	 * @param ec error_code contains additional information for parsing errors
	 *
	 * @return boost::tribool result of parsing:
	 *                        false = message has an error,
	 *                        true = finished parsing HTTP message,
	 *                        indeterminate = not yet finished parsing HTTP message
	 */
	boost::tribool parseMissingData(HTTPMessage& http_msg, std::size_t len,
		boost::system::error_code& ec);

	/**
	 * finishes parsing an HTTP response message
	 *
	 * @param http_msg the HTTP message object to finish
	 */
	void finish(HTTPMessage& http_msg) const;

	/**
	 * resets the location and size of the read buffer
	 *
	 * @param ptr pointer to the first bytes available to be read
	 * @param len number of bytes available to be read
	 */
	inline void setReadBuffer(const char *ptr, size_t len) {
		m_read_ptr = ptr;
		m_read_end_ptr = ptr + len;
	}

	/**
	 * loads a read position bookmark
	 *
	 * @param read_ptr points to the next character to be consumed in the read_buffer
	 * @param read_end_ptr points to the end of the read_buffer (last byte + 1)
	 */
	inline void loadReadPosition(const char *&read_ptr, const char *&read_end_ptr) const {
		read_ptr = m_read_ptr;
		read_end_ptr = m_read_end_ptr;
	}

	/**
	 * checks to see if a premature EOF was encountered while parsing.  This
	 * should be called if there is no more data to parse, and if the last
	 * call to the parse() function returned boost::indeterminate
	 *
	 * @param http_msg the HTTP message object being parsed
	 * @return true if premature EOF, false if message is OK & finished parsing
	 */
	inline bool checkPrematureEOF(HTTPMessage& http_msg) {
		if (m_message_parse_state != PARSE_CONTENT_NO_LENGTH)
			return true;
		m_message_parse_state = PARSE_END;
		http_msg.concatenateChunks();
		finish(http_msg);
		return false;
	}

	/**
	 * controls headers-only parsing (default is disabled; content parsed also)
	 *
	 * @param b if true, then the parse() function returns true after headers
	 */
	inline void parseHeadersOnly(bool b = true) { m_parse_headers_only = b; }

	/**
	 * skip parsing all headers and parse payload content only
	 *
	 * @param http_msg the HTTP message object being parsed
	 */
	inline void skipHeaderParsing(HTTPMessage& http_msg) {
		boost::system::error_code ec;
		finishHeaderParsing(http_msg, ec);
	}
	
	/// resets the parser to its initial state
	inline void reset(void) {
		m_message_parse_state = PARSE_START;
		m_headers_parse_state = (m_is_request ? PARSE_METHOD_START : PARSE_HTTP_VERSION_H);
		m_chunked_content_parse_state = PARSE_CHUNK_SIZE_START;
		m_status_code = 0;
		m_status_message.erase();
		m_method.erase();
		m_resource.erase();
		m_query_string.erase();
		m_raw_headers.erase();
		m_bytes_content_read = m_bytes_last_read = m_bytes_total_read = 0;
	}

	/// returns true if there are no more bytes available in the read buffer
	inline bool eof(void) const { return m_read_ptr == NULL || m_read_ptr >= m_read_end_ptr; }

	/// returns the number of bytes available in the read buffer
	inline std::size_t bytes_available(void) const { return (eof() ? 0 : (std::size_t)(m_read_end_ptr - m_read_ptr)); } 

	/// returns the number of bytes read during the last parse operation
	inline std::size_t gcount(void) const { return m_bytes_last_read; }

	/// returns the total number of bytes read while parsing the HTTP message
	inline std::size_t getTotalBytesRead(void) const { return m_bytes_total_read; }

	/// returns the total number of bytes read while parsing the payload content
	inline std::size_t getContentBytesRead(void) const { return m_bytes_content_read; }

	/// returns the maximum length for HTTP payload content
	inline std::size_t getMaxContentLength(void) const { return m_max_content_length; }

	/// returns the raw HTTP headers saved by the parser
	inline const std::string& getRawHeaders(void) const { return m_raw_headers; }

	/// returns true if the parser is saving raw HTTP header contents
	inline bool getSaveRawHeaders(void) const { return m_save_raw_headers; }

	/// returns true if the parser is being used to parse an HTTP request
	inline bool isParsingRequest(void) const { return m_is_request; }

	/// returns true if the parser is being used to parse an HTTP response
	inline bool isParsingResponse(void) const { return ! m_is_request; }

	/// sets the maximum length for HTTP payload content
	inline void setMaxContentLength(std::size_t n) { m_max_content_length = n; }

	/// resets the maximum length for HTTP payload content to the default value
	inline void resetMaxContentLength(void) { m_max_content_length = DEFAULT_CONTENT_MAX; }

	/// sets parameter for saving raw HTTP header content
	inline void setSaveRawHeaders(bool b) { m_save_raw_headers = b; }

	/// sets the logger to be used
	inline void setLogger(PionLogger log_ptr) { m_logger = log_ptr; }

	/// returns the logger currently in use
	inline PionLogger getLogger(void) { return m_logger; }


	/**
	 * parse key-value pairs out of a url-encoded string
	 * (i.e. this=that&a=value)
	 * 
	 * @param dict dictionary for key-values pairs
	 * @param ptr points to the start of the encoded string
	 * @param len length of the encoded string, in bytes
	 * 
	 * @return bool true if successful
	 */
	static bool parseURLEncoded(HTTPTypes::QueryParams& dict,
								const char *ptr, const std::size_t len);

	/**
	 * parse key-value pairs out of a "Cookie" request header
	 * (i.e. this=that; a=value)
	 * 
	 * @param dict dictionary for key-values pairs
	 * @param ptr points to the start of the header string to be parsed
	 * @param len length of the encoded string, in bytes
	 * @param set_cookie_header set true if parsing Set-Cookie response header
	 * 
	 * @return bool true if successful
	 */
	static bool parseCookieHeader(HTTPTypes::CookieParams& dict,
								  const char *ptr, const std::size_t len,
								  bool set_cookie_header);

	/**
	 * parse key-value pairs out of a "Cookie" request header
	 * (i.e. this=that; a=value)
	 * 
	 * @param dict dictionary for key-values pairs
	 * @param cookie_header header string to be parsed
	 * @param set_cookie_header set true if parsing Set-Cookie response header
	 * 
	 * @return bool true if successful
	 */
	static inline bool parseCookieHeader(HTTPTypes::CookieParams& dict,
		const std::string& cookie_header, bool set_cookie_header)
	{
		return parseCookieHeader(dict, cookie_header.c_str(), cookie_header.size(), set_cookie_header);
	}

	/**
	 * parse key-value pairs out of a url-encoded string
	 * (i.e. this=that&a=value)
	 * 
	 * @param dict dictionary for key-values pairs
	 * @param query the encoded query string to be parsed
	 * 
	 * @return bool true if successful
	 */
	static inline bool parseURLEncoded(HTTPTypes::QueryParams& dict,
		const std::string& query)
	{
		return parseURLEncoded(dict, query.c_str(), query.size());
	}

	/**
	 * parses an X-Forwarded-For HTTP header, and extracts from it an IP
	 * address that best matches the client's public IP address (if any are found)
	 *
	 * @param header the X-Forwarded-For HTTP header to parse
	 * @param public_ip the extract IP address, if found
	 *
	 * @return bool true if a public IP address was found and extracted
	 */
	static bool parseForwardedFor(const std::string& header, std::string& public_ip);
	
	/// returns an instance of HTTPParser::ErrorCategory
	static inline ErrorCategory& getErrorCategory(void) {
		boost::call_once(HTTPParser::createErrorCategory, m_instance_flag);
		return *m_error_category_ptr;
	}


protected:

	/**
	 * parses an HTTP message up to the end of the headers using bytes 
	 * available in the read buffer
	 *
	 * @param http_msg the HTTP message object to populate from parsing
	 * @param ec error_code contains additional information for parsing errors
	 *
	 * @return boost::tribool result of parsing:
	 *                        false = message has an error,
	 *                        true = finished parsing HTTP headers,
	 *                        indeterminate = not yet finished parsing HTTP headers
	 */
	boost::tribool parseHeaders(HTTPMessage& http_msg, boost::system::error_code& ec);

	/**
	 * updates an HTTPMessage object with data obtained from parsing headers
	 *
	 * @param http_msg the HTTP message object to populate from parsing
	 */
	void updateMessageWithHeaderData(HTTPMessage& http_msg) const;

	/**
	 * should be called after parsing HTTP headers, to prepare for payload content parsing
	 * available in the read buffer
	 *
	 * @param http_msg the HTTP message object to populate from parsing
	 * @param ec error_code contains additional information for parsing errors
	 *
	 * @return boost::tribool result of parsing:
	 *                        false = message has an error,
	 *                        true = finished parsing HTTP message (no content),
	 *                        indeterminate = payload content is available to be parsed
	 */
	boost::tribool finishHeaderParsing(HTTPMessage& http_msg,
		boost::system::error_code& ec);

	/**
	 * parses a chunked HTTP message-body using bytes available in the read buffer
	 *
	 * @param chunk_buffers buffers to be populated from parsing chunked content
	 * @param ec error_code contains additional information for parsing errors
	 *
	 * @return boost::tribool result of parsing:
	 *                        false = message has an error,
	 *                        true = finished parsing message,
	 *                        indeterminate = message is not yet finished
	 */
	boost::tribool parseChunks(HTTPMessage::ChunkCache& chunk_buffers,
		boost::system::error_code& ec);

	/**
	 * consumes payload content in the parser's read buffer 
	 *
	 * @param http_msg the HTTP message object to consume content for
	 * @param ec error_code contains additional information for parsing errors
	 *  
	 * @return boost::tribool result of parsing:
	 *                        false = message has an error,
	 *                        true = finished parsing message,
	 *                        indeterminate = message is not yet finished
	 */
	boost::tribool consumeContent(HTTPMessage& http_msg,
		boost::system::error_code& ec);

	/**
	 * consume the bytes available in the read buffer, converting them into
	 * the next chunk for the HTTP message
	 *
	 * @param chunk_buffers buffers to be populated from parsing chunked content
	 * @return std::size_t number of content bytes consumed, if any
	 */
	std::size_t consumeContentAsNextChunk(HTTPMessage::ChunkCache& chunk_buffers);

	/**
	 * compute and sets a HTTP Message data integrity status
	 * @param http_msg target HTTP message 
	 * @param msg_parsed_ok message parsing result
	 */
	static void computeMsgStatus(HTTPMessage& http_msg, bool msg_parsed_ok);

	/**
	 * sets an error code
	 *
	 * @param ec error code variable to define
	 * @param ev error value to raise
	 */
	static inline void setError(boost::system::error_code& ec, ErrorValue ev) {
		ec = boost::system::error_code(static_cast<int>(ev), getErrorCategory());
	}

	/// creates the unique HTTPParser ErrorCategory
	static void createErrorCategory(void);


	// misc functions used by the parsing functions
	inline static bool isChar(int c);
	inline static bool isControl(int c);
	inline static bool isSpecial(int c);
	inline static bool isDigit(int c);
	inline static bool isHexDigit(int c);
	inline static bool isCookieAttribute(const std::string& name, bool set_cookie_header);


	/// maximum length for response status message
	static const boost::uint32_t		STATUS_MESSAGE_MAX;

	/// maximum length for the request method
	static const boost::uint32_t		METHOD_MAX;

	/// maximum length for the resource requested
	static const boost::uint32_t		RESOURCE_MAX;

	/// maximum length for the query string
	static const boost::uint32_t		QUERY_STRING_MAX;

	/// maximum length for an HTTP header name
	static const boost::uint32_t		HEADER_NAME_MAX;

	/// maximum length for an HTTP header value
	static const boost::uint32_t		HEADER_VALUE_MAX;

	/// maximum length for the name of a query string variable
	static const boost::uint32_t		QUERY_NAME_MAX;

	/// maximum length for the value of a query string variable
	static const boost::uint32_t		QUERY_VALUE_MAX;

	/// maximum length for the name of a cookie name
	static const boost::uint32_t		COOKIE_NAME_MAX;

	/// maximum length for the value of a cookie; also used for path and domain
	static const boost::uint32_t		COOKIE_VALUE_MAX;


	/// primary logging interface used by this class
	mutable PionLogger					m_logger;

	/// true if the message is an HTTP request; false if it is an HTTP response
	const bool							m_is_request;

	/// points to the next character to be consumed in the read_buffer
	const char *						m_read_ptr;

	/// points to the end of the read_buffer (last byte + 1)
	const char *						m_read_end_ptr;


private:

	/// state used to keep track of where we are in parsing the HTTP message
	enum MessageParseState {
		PARSE_START, PARSE_HEADERS, PARSE_CONTENT,
		PARSE_CONTENT_NO_LENGTH, PARSE_CHUNKS, PARSE_END
	};

	/// state used to keep track of where we are in parsing the HTTP headers
	/// (only used if MessageParseState == PARSE_HEADERS)
	enum HeadersParseState {
		PARSE_METHOD_START, PARSE_METHOD, PARSE_URI_STEM, PARSE_URI_QUERY,
		PARSE_HTTP_VERSION_H, PARSE_HTTP_VERSION_T_1, PARSE_HTTP_VERSION_T_2,
		PARSE_HTTP_VERSION_P, PARSE_HTTP_VERSION_SLASH,
		PARSE_HTTP_VERSION_MAJOR_START, PARSE_HTTP_VERSION_MAJOR,
		PARSE_HTTP_VERSION_MINOR_START, PARSE_HTTP_VERSION_MINOR,
		PARSE_STATUS_CODE_START, PARSE_STATUS_CODE, PARSE_STATUS_MESSAGE,
		PARSE_EXPECTING_NEWLINE, PARSE_EXPECTING_CR,
		PARSE_HEADER_WHITESPACE, PARSE_HEADER_START, PARSE_HEADER_NAME,
		PARSE_SPACE_BEFORE_HEADER_VALUE, PARSE_HEADER_VALUE,
		PARSE_EXPECTING_FINAL_NEWLINE, PARSE_EXPECTING_FINAL_CR
	};

	/// state used to keep track of where we are in parsing chunked content
	/// (only used if MessageParseState == PARSE_CHUNKS)
	enum ChunkedContentParseState {
		PARSE_CHUNK_SIZE_START, PARSE_CHUNK_SIZE, 
		PARSE_EXPECTING_CR_AFTER_CHUNK_SIZE,
		PARSE_EXPECTING_LF_AFTER_CHUNK_SIZE, PARSE_CHUNK, 
		PARSE_EXPECTING_CR_AFTER_CHUNK, PARSE_EXPECTING_LF_AFTER_CHUNK,
		PARSE_EXPECTING_FINAL_CR_AFTER_LAST_CHUNK, 
		PARSE_EXPECTING_FINAL_LF_AFTER_LAST_CHUNK
	};


	/// the current state of parsing HTTP headers
	MessageParseState					m_message_parse_state;

	/// the current state of parsing HTTP headers
	HeadersParseState					m_headers_parse_state;

	/// the current state of parsing chunked content
	ChunkedContentParseState			m_chunked_content_parse_state;

	/// Used for parsing the HTTP response status code
	boost::uint16_t						m_status_code;

	/// Used for parsing the HTTP response status message
	std::string							m_status_message;

	/// Used for parsing the request method
	std::string							m_method;

	/// Used for parsing the name of resource requested
	std::string							m_resource;

	/// Used for parsing the query string portion of a URI
	std::string							m_query_string;

	/// Used to store the raw contents of HTTP headers when m_save_raw_headers is true
	std::string							m_raw_headers;

	/// Used for parsing the name of HTTP headers
	std::string							m_header_name;

	/// Used for parsing the value of HTTP headers
	std::string							m_header_value;

	/// Used for parsing the chunk size
	std::string							m_chunk_size_str;

	/// number of bytes in the chunk currently being parsed
	std::size_t 						m_size_of_current_chunk;

	/// number of bytes read so far in the chunk currently being parsed
	std::size_t 						m_bytes_read_in_current_chunk;

	/// number of payload content bytes that have not yet been read
	std::size_t							m_bytes_content_remaining;

	/// number of bytes read so far into the message's payload content
	std::size_t							m_bytes_content_read;

	/// number of bytes read during last parse operation
	std::size_t							m_bytes_last_read;

	/// total number of bytes read while parsing the HTTP message
	std::size_t							m_bytes_total_read;

	/// maximum length for HTTP payload content
	std::size_t							m_max_content_length;
	
	/// if true, then only HTTP headers will be parsed (no content parsing)
	bool								m_parse_headers_only;

	/// if true, the raw contents of HTTP headers are stored into m_raw_headers
	bool								m_save_raw_headers;

	/// points to a single and unique instance of the HTTPParser ErrorCategory
	static ErrorCategory *				m_error_category_ptr;
		
	/// used to ensure thread safety of the HTTPParser ErrorCategory
	static boost::once_flag				m_instance_flag;
};


// inline functions for HTTPParser

inline bool HTTPParser::isChar(int c)
{
	return(c >= 0 && c <= 127);
}

inline bool HTTPParser::isControl(int c)
{
	return( (c >= 0 && c <= 31) || c == 127);
}

inline bool HTTPParser::isSpecial(int c)
{
	switch (c) {
	case '(': case ')': case '<': case '>': case '@':
	case ',': case ';': case ':': case '\\': case '"':
	case '/': case '[': case ']': case '?': case '=':
	case '{': case '}': case ' ': case '\t':
		return true;
	default:
		return false;
	}
}

inline bool HTTPParser::isDigit(int c)
{
	return(c >= '0' && c <= '9');
}

inline bool HTTPParser::isHexDigit(int c)
{
	return((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F'));
}

inline bool HTTPParser::isCookieAttribute(const std::string& name, bool set_cookie_header)
{
	return (name.empty() || name[0] == '$' || (set_cookie_header &&
		(name=="Comment" || name=="Domain" || name=="Max-Age" || name=="Path" || name=="Secure" || name=="Version" || name=="Expires")
		) );
}

}	// end namespace net
}	// end namespace pion

#endif