diff options
Diffstat (limited to 'websocketpp/processors/processor.hpp')
| -rw-r--r-- | websocketpp/processors/processor.hpp | 407 |
1 files changed, 407 insertions, 0 deletions
diff --git a/websocketpp/processors/processor.hpp b/websocketpp/processors/processor.hpp new file mode 100644 index 00000000..5131cc45 --- /dev/null +++ b/websocketpp/processors/processor.hpp @@ -0,0 +1,407 @@ +/* + * Copyright (c) 2015, Peter Thorson. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * * Neither the name of the WebSocket++ Project nor the + * names of its contributors may be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL PETER THORSON BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +#ifndef WEBSOCKETPP_PROCESSOR_HPP +#define WEBSOCKETPP_PROCESSOR_HPP + +#include <websocketpp/processors/base.hpp> +#include <websocketpp/common/system_error.hpp> + +#include <websocketpp/close.hpp> +#include <websocketpp/utilities.hpp> +#include <websocketpp/uri.hpp> + +#include <sstream> +#include <string> +#include <utility> +#include <vector> + +namespace websocketpp { +/// Processors encapsulate the protocol rules specific to each WebSocket version +/** + * The processors namespace includes a number of free functions that operate on + * various WebSocket related data structures and perform processing that is not + * related to specific versions of the protocol. + * + * It also includes the abstract interface for the protocol specific processing + * engines. These engines wrap all of the logic necessary for parsing and + * validating WebSocket handshakes and messages of specific protocol version + * and set of allowed extensions. + * + * An instance of a processor represents the state of a single WebSocket + * connection of the associated version. One processor instance is needed per + * logical WebSocket connection. + */ +namespace processor { + +/// Determine whether or not a generic HTTP request is a WebSocket handshake +/** + * @param r The HTTP request to read. + * + * @return True if the request is a WebSocket handshake, false otherwise + */ +template <typename request_type> +bool is_websocket_handshake(request_type& r) { + using utility::ci_find_substr; + + std::string const & upgrade_header = r.get_header("Upgrade"); + + if (ci_find_substr(upgrade_header, constants::upgrade_token, + sizeof(constants::upgrade_token)-1) == upgrade_header.end()) + { + return false; + } + + std::string const & con_header = r.get_header("Connection"); + + if (ci_find_substr(con_header, constants::connection_token, + sizeof(constants::connection_token)-1) == con_header.end()) + { + return false; + } + + return true; +} + +/// Extract the version from a WebSocket handshake request +/** + * A blank version header indicates a spec before versions were introduced. + * The only such versions in shipping products are Hixie Draft 75 and Hixie + * Draft 76. Draft 75 is present in Chrome 4-5 and Safari 5.0.0, Draft 76 (also + * known as hybi 00 is present in Chrome 6-13 and Safari 5.0.1+. As + * differentiating between these two sets of browsers is very difficult and + * Safari 5.0.1+ accounts for the vast majority of cases in the wild this + * function assumes that all handshakes without a valid version header are + * Hybi 00. + * + * @param r The WebSocket handshake request to read. + * + * @return The WebSocket handshake version or -1 if there was an extraction + * error. + */ +template <typename request_type> +int get_websocket_version(request_type& r) { + if (!r.ready()) { + return -2; + } + + if (r.get_header("Sec-WebSocket-Version").empty()) { + return 0; + } + + int version; + std::istringstream ss(r.get_header("Sec-WebSocket-Version")); + + if ((ss >> version).fail()) { + return -1; + } + + return version; +} + +/// Extract a URI ptr from the host header of the request +/** + * @param request The request to extract the Host header from. + * + * @param scheme The scheme under which this request was received (ws, wss, + * http, https, etc) + * + * @return A uri_pointer that encodes the value of the host header. + */ +template <typename request_type> +uri_ptr get_uri_from_host(request_type & request, std::string scheme) { + std::string h = request.get_header("Host"); + + size_t last_colon = h.rfind(":"); + size_t last_sbrace = h.rfind("]"); + + // no : = hostname with no port + // last : before ] = ipv6 literal with no port + // : with no ] = hostname with port + // : after ] = ipv6 literal with port + if (last_colon == std::string::npos || + (last_sbrace != std::string::npos && last_sbrace > last_colon)) + { + return lib::make_shared<uri>(scheme, h, request.get_uri()); + } else { + return lib::make_shared<uri>(scheme, + h.substr(0,last_colon), + h.substr(last_colon+1), + request.get_uri()); + } +} + +/// WebSocket protocol processor abstract base class +template <typename config> +class processor { +public: + typedef processor<config> type; + typedef typename config::request_type request_type; + typedef typename config::response_type response_type; + typedef typename config::message_type::ptr message_ptr; + typedef std::pair<lib::error_code,std::string> err_str_pair; + + explicit processor(bool secure, bool p_is_server) + : m_secure(secure) + , m_server(p_is_server) + , m_max_message_size(config::max_message_size) + {} + + virtual ~processor() {} + + /// Get the protocol version of this processor + virtual int get_version() const = 0; + + /// Get maximum message size + /** + * Get maximum message size. Maximum message size determines the point at which the + * processor will fail a connection with the message_too_big protocol error. + * + * The default is retrieved from the max_message_size value from the template config + * + * @since 0.3.0 + */ + size_t get_max_message_size() const { + return m_max_message_size; + } + + /// Set maximum message size + /** + * Set maximum message size. Maximum message size determines the point at which the + * processor will fail a connection with the message_too_big protocol error. + * + * The default is retrieved from the max_message_size value from the template config + * + * @since 0.3.0 + * + * @param new_value The value to set as the maximum message size. + */ + void set_max_message_size(size_t new_value) { + m_max_message_size = new_value; + } + + /// Returns whether or not the permessage_compress extension is implemented + /** + * Compile time flag that indicates whether this processor has implemented + * the permessage_compress extension. By default this is false. + */ + virtual bool has_permessage_compress() const { + return false; + } + + /// Initializes extensions based on the Sec-WebSocket-Extensions header + /** + * Reads the Sec-WebSocket-Extensions header and determines if any of the + * requested extensions are supported by this processor. If they are their + * settings data is initialized and an extension string to send to the + * is returned. + * + * @param request The request or response headers to look at. + */ + virtual err_str_pair negotiate_extensions(request_type const &) { + return err_str_pair(); + } + + /// Initializes extensions based on the Sec-WebSocket-Extensions header + /** + * Reads the Sec-WebSocket-Extensions header and determines if any of the + * requested extensions were accepted by the server. If they are their + * settings data is initialized. If they are not a list of required + * extensions (if any) is returned. This list may be sent back to the server + * as a part of the 1010/Extension required close code. + * + * @param response The request or response headers to look at. + */ + virtual err_str_pair negotiate_extensions(response_type const &) { + return err_str_pair(); + } + + /// validate a WebSocket handshake request for this version + /** + * @param request The WebSocket handshake request to validate. + * is_websocket_handshake(request) must be true and + * get_websocket_version(request) must equal this->get_version(). + * + * @return A status code, 0 on success, non-zero for specific sorts of + * failure + */ + virtual lib::error_code validate_handshake(request_type const & request) const = 0; + + /// Calculate the appropriate response for this websocket request + /** + * @param req The request to process + * + * @param subprotocol The subprotocol in use + * + * @param res The response to store the processed response in + * + * @return An error code, 0 on success, non-zero for other errors + */ + virtual lib::error_code process_handshake(request_type const & req, + std::string const & subprotocol, response_type& res) const = 0; + + /// Fill in an HTTP request for an outgoing connection handshake + /** + * @param req The request to process. + * + * @return An error code, 0 on success, non-zero for other errors + */ + virtual lib::error_code client_handshake_request(request_type & req, + uri_ptr uri, std::vector<std::string> const & subprotocols) const = 0; + + /// Validate the server's response to an outgoing handshake request + /** + * @param req The original request sent + * @param res The reponse to generate + * @return An error code, 0 on success, non-zero for other errors + */ + virtual lib::error_code validate_server_handshake_response(request_type + const & req, response_type & res) const = 0; + + /// Given a completed response, get the raw bytes to put on the wire + virtual std::string get_raw(response_type const & request) const = 0; + + /// Return the value of the header containing the CORS origin. + virtual std::string const & get_origin(request_type const & request) const = 0; + + /// Extracts requested subprotocols from a handshake request + /** + * Extracts a list of all subprotocols that the client has requested in the + * given opening handshake request. + * + * @param [in] req The request to extract from + * @param [out] subprotocol_list A reference to a vector of strings to store + * the results in. + */ + virtual lib::error_code extract_subprotocols(const request_type & req, + std::vector<std::string> & subprotocol_list) = 0; + + /// Extracts client uri from a handshake request + virtual uri_ptr get_uri(request_type const & request) const = 0; + + /// process new websocket connection bytes + /** + * WebSocket connections are a continous stream of bytes that must be + * interpreted by a protocol processor into discrete frames. + * + * @param buf Buffer from which bytes should be read. + * @param len Length of buffer + * @param ec Reference to an error code to return any errors in + * @return Number of bytes processed + */ + virtual size_t consume(uint8_t *buf, size_t len, lib::error_code & ec) = 0; + + /// Checks if there is a message ready + /** + * Checks if the most recent consume operation processed enough bytes to + * complete a new WebSocket message. The message can be retrieved by calling + * get_message() which will reset the internal state to not-ready and allow + * consume to read more bytes. + * + * @return Whether or not a message is ready. + */ + virtual bool ready() const = 0; + + /// Retrieves the most recently processed message + /** + * Retrieves a shared pointer to the recently completed message if there is + * one. If ready() returns true then there is a message available. + * Retrieving the message with get_message will reset the state of ready. + * As such, each new message may be retrieved only once. Calling get_message + * when there is no message available will result in a null pointer being + * returned. + * + * @return A pointer to the most recently processed message or a null shared + * pointer. + */ + virtual message_ptr get_message() = 0; + + /// Tests whether the processor is in a fatal error state + virtual bool get_error() const = 0; + + /// Retrieves the number of bytes presently needed by the processor + /// This value may be used as a hint to the transport layer as to how many + /// bytes to wait for before running consume again. + virtual size_t get_bytes_needed() const { + return 1; + } + + /// Prepare a data message for writing + /** + * Performs validation, masking, compression, etc. will return an error if + * there was an error, otherwise msg will be ready to be written + */ + virtual lib::error_code prepare_data_frame(message_ptr in, message_ptr out) = 0; + + /// Prepare a ping frame + /** + * Ping preparation is entirely state free. There is no payload validation + * other than length. Payload need not be UTF-8. + * + * @param in The string to use for the ping payload + * @param out The message buffer to prepare the ping in. + * @return Status code, zero on success, non-zero on failure + */ + virtual lib::error_code prepare_ping(std::string const & in, message_ptr out) const + = 0; + + /// Prepare a pong frame + /** + * Pong preparation is entirely state free. There is no payload validation + * other than length. Payload need not be UTF-8. + * + * @param in The string to use for the pong payload + * @param out The message buffer to prepare the pong in. + * @return Status code, zero on success, non-zero on failure + */ + virtual lib::error_code prepare_pong(std::string const & in, message_ptr out) const + = 0; + + /// Prepare a close frame + /** + * Close preparation is entirely state free. The code and reason are both + * subject to validation. Reason must be valid UTF-8. Code must be a valid + * un-reserved WebSocket close code. Use close::status::no_status to + * indicate no code. If no code is supplied a reason may not be specified. + * + * @param code The close code to send + * @param reason The reason string to send + * @param out The message buffer to prepare the fame in + * @return Status code, zero on success, non-zero on failure + */ + virtual lib::error_code prepare_close(close::status::value code, + std::string const & reason, message_ptr out) const = 0; +protected: + bool const m_secure; + bool const m_server; + size_t m_max_message_size; +}; + +} // namespace processor +} // namespace websocketpp + +#endif //WEBSOCKETPP_PROCESSOR_HPP |