+/*
+ * InspIRCd -- Internet Relay Chat Daemon
+ *
+ * Copyright (C) 2020 Matt Schatz <genius3000@g3k.solutions>
+ * Copyright (C) 2019 linuxdaemon <linuxdaemon.irc@gmail.com>
+ * Copyright (C) 2013, 2015-2016 Attila Molnar <attilamolnar@hush.com>
+ * Copyright (C) 2012-2013, 2017-2019 Sadie Powell <sadie@witchery.services>
+ * Copyright (C) 2012 Robby <robby@chatbelgie.be>
+ * Copyright (C) 2009 Uli Schlachter <psychon@inspircd.org>
+ * Copyright (C) 2009 Daniel De Graaf <danieldg@inspircd.org>
+ * Copyright (C) 2007-2009 Robin Burchell <robin+git@viroteck.net>
+ * Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
+ * Copyright (C) 2006, 2010 Craig Edwards <brain@inspircd.org>
+ * Copyright (C) 2006 Oliver Lupton <om@inspircd.org>
+ *
+ * This file is part of InspIRCd. InspIRCd is free software: you can
+ * redistribute it and/or modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#pragma once
+
+#include "timer.h"
+
+class IOHook;
+
+/**
+ * States which a socket may be in
+ */
+enum BufferedSocketState
+{
+ /** Socket disconnected */
+ I_DISCONNECTED,
+ /** Socket connecting */
+ I_CONNECTING,
+ /** Socket fully connected */
+ I_CONNECTED,
+ /** Socket has an error */
+ I_ERROR
+};
+
+/**
+ * Error types which a socket may exhibit
+ */
+enum BufferedSocketError
+{
+ /** No error */
+ I_ERR_NONE,
+ /** Socket was closed by peer */
+ I_ERR_DISCONNECT,
+ /** Socket connect timed out */
+ I_ERR_TIMEOUT,
+ /** Socket could not be created */
+ I_ERR_SOCKET,
+ /** Socket could not connect (refused) */
+ I_ERR_CONNECT,
+ /** Socket could not bind to local port/ip */
+ I_ERR_BIND,
+ /** Socket could not write data */
+ I_ERR_WRITE,
+ /** No more file descriptors left to create socket! */
+ I_ERR_NOMOREFDS,
+ /** Some other error */
+ I_ERR_OTHER
+};
+
+/* Required forward declarations */
+class BufferedSocket;
+
+/** Used to time out socket connections
+ */
+class CoreExport SocketTimeout : public Timer
+{
+ private:
+ /** BufferedSocket the class is attached to
+ */
+ BufferedSocket* sock;
+
+ /** File descriptor of class this is attached to
+ */
+ int sfd;
+
+ public:
+ /** Create a socket timeout class
+ * @param fd File descriptor of BufferedSocket
+ * @param thesock BufferedSocket to attach to
+ * @param secs_from_now Seconds from now to time out
+ */
+ SocketTimeout(int fd, BufferedSocket* thesock, unsigned int secs_from_now)
+ : Timer(secs_from_now)
+ , sock(thesock)
+ , sfd(fd)
+ {
+ }
+
+ /** Handle tick event
+ */
+ bool Tick(time_t now) CXX11_OVERRIDE;
+};
+
+/**
+ * StreamSocket is a class that wraps a TCP socket and handles send
+ * and receive queues, including passing them to IO hooks
+ */
+class CoreExport StreamSocket : public EventHandler
+{
+ public:
+ /** Socket send queue
+ */
+ class SendQueue
+ {
+ public:
+ /** One element of the queue, a continuous buffer
+ */
+ typedef std::string Element;
+
+ /** Sequence container of buffers in the queue
+ */
+ typedef std::deque<Element> Container;
+
+ /** Container iterator
+ */
+ typedef Container::const_iterator const_iterator;
+
+ SendQueue() : nbytes(0) { }
+
+ /** Return whether the queue is empty
+ * @return True if the queue is empty, false otherwise
+ */
+ bool empty() const { return (nbytes == 0); }
+
+ /** Get the number of individual buffers in the queue
+ * @return Number of individual buffers in the queue
+ */
+ Container::size_type size() const { return data.size(); }
+
+ /** Get the number of queued bytes
+ * @return Size in bytes of the data in the queue
+ */
+ size_t bytes() const { return nbytes; }
+
+ /** Get the first buffer of the queue
+ * @return A reference to the first buffer in the queue
+ */
+ const Element& front() const { return data.front(); }
+
+ /** Get an iterator to the first buffer in the queue.
+ * The returned iterator cannot be used to make modifications to the queue,
+ * for that purpose the member functions push_*(), pop_front(), erase_front() and clear() can be used.
+ * @return Iterator referring to the first buffer in the queue, or end() if there are no elements.
+ */
+ const_iterator begin() const { return data.begin(); }
+
+ /** Get an iterator to the (theoretical) buffer one past the end of the queue.
+ * @return Iterator referring to one element past the end of the container
+ */
+ const_iterator end() const { return data.end(); }
+
+ /** Remove the first buffer in the queue
+ */
+ void pop_front()
+ {
+ nbytes -= data.front().length();
+ data.pop_front();
+ }
+
+ /** Remove bytes from the beginning of the first buffer
+ * @param n Number of bytes to remove
+ */
+ void erase_front(Element::size_type n)
+ {
+ nbytes -= n;
+ data.front().erase(0, n);
+ }
+
+ /** Insert a new buffer at the beginning of the queue
+ * @param newdata Data to add
+ */
+ void push_front(const Element& newdata)
+ {
+ data.push_front(newdata);
+ nbytes += newdata.length();
+ }
+
+ /** Insert a new buffer at the end of the queue
+ * @param newdata Data to add
+ */
+ void push_back(const Element& newdata)
+ {
+ data.push_back(newdata);
+ nbytes += newdata.length();
+ }
+
+ /** Clear the queue
+ */
+ void clear()
+ {
+ data.clear();
+ nbytes = 0;
+ }
+
+ void moveall(SendQueue& other)
+ {
+ nbytes += other.bytes();
+ data.insert(data.end(), other.data.begin(), other.data.end());
+ other.clear();
+ }
+
+ private:
+ /** Private send queue. Note that individual strings may be shared.
+ */
+ Container data;
+
+ /** Length, in bytes, of the sendq
+ */
+ size_t nbytes;
+ };
+
+ /** The type of socket this IOHook represents. */
+ enum Type
+ {
+ SS_UNKNOWN,
+ SS_USER
+ };
+
+ private:
+ /** Whether this socket should close once its sendq is empty */
+ bool closeonempty;
+
+ /** Whether the socket is currently closing or not, used to avoid repeatedly closing a closed socket */
+ bool closing;
+
+ /** The IOHook that handles raw I/O for this socket, or NULL */
+ IOHook* iohook;
+
+ /** Send queue of the socket
+ */
+ SendQueue sendq;
+
+ /** Error - if nonempty, the socket is dead, and this is the reason. */
+ std::string error;
+
+ /** Check if the socket has an error set, if yes, call OnError
+ * @param err Error to pass to OnError()
+ */
+ void CheckError(BufferedSocketError err);
+
+ /** Read data from the socket into the recvq, if successful call OnDataReady()
+ */
+ void DoRead();
+
+ /** Send as much data contained in a SendQueue object as possible.
+ * All data which successfully sent will be removed from the SendQueue.
+ * @param sq SendQueue to flush
+ */
+ void FlushSendQ(SendQueue& sq);
+
+ /** Read incoming data into a receive queue.
+ * @param rq Receive queue to put incoming data into
+ * @return < 0 on error or close, 0 if no new data is ready (but the socket is still connected), > 0 if data was read from the socket and put into the recvq
+ */
+ int ReadToRecvQ(std::string& rq);
+
+ /** Read data from a hook chain recursively, starting at 'hook'.
+ * If 'hook' is NULL, the recvq is filled with data from SocketEngine::Recv(), otherwise it is filled with data from the
+ * next hook in the chain.
+ * @param hook Next IOHook in the chain, can be NULL
+ * @param rq Receive queue to put incoming data into
+ * @return < 0 on error or close, 0 if no new data is ready (but the socket is still connected), > 0 if data was read from
+ * the socket and put into the recvq
+ */
+ int HookChainRead(IOHook* hook, std::string& rq);
+
+ protected:
+ /** The data which has been received from the socket. */
+ std::string recvq;
+
+ /** Swaps the internals of this StreamSocket with another one.
+ * @param other A StreamSocket to swap internals with.
+ */
+ void SwapInternals(StreamSocket& other);
+
+ public:
+ const Type type;
+ StreamSocket(Type sstype = SS_UNKNOWN)
+ : closeonempty(false)
+ , closing(false)
+ , iohook(NULL)
+ , type(sstype)
+ {
+ }
+ IOHook* GetIOHook() const;
+ void AddIOHook(IOHook* hook);
+ void DelIOHook();
+
+ /** Flush the send queue
+ */
+ void DoWrite();
+
+ /** Called by the socket engine on a read event
+ */
+ void OnEventHandlerRead() CXX11_OVERRIDE;
+
+ /** Called by the socket engine on a write event
+ */
+ void OnEventHandlerWrite() CXX11_OVERRIDE;
+
+ /** Called by the socket engine on error
+ * @param errcode Error
+ */
+ void OnEventHandlerError(int errcode) CXX11_OVERRIDE;
+
+ /** Sets the error message for this socket. Once set, the socket is dead. */
+ void SetError(const std::string& err) { if (error.empty()) error = err; }
+
+ /** Gets the error message for this socket. */
+ const std::string& getError() const { return error; }
+
+ /** Called when new data is present in recvq */
+ virtual void OnDataReady() = 0;
+ /** Called when the socket gets an error from socket engine or IO hook */
+ virtual void OnError(BufferedSocketError e) = 0;
+
+ /** Called when the endpoint addresses are changed.
+ * @param local The new local endpoint.
+ * @param remote The new remote endpoint.
+ * @return true if the connection is still open, false if it has been closed
+ */
+ virtual bool OnSetEndPoint(const irc::sockets::sockaddrs& local, const irc::sockets::sockaddrs& remote);
+
+ /** Send the given data out the socket, either now or when writes unblock
+ */
+ void WriteData(const std::string& data);
+ /** Convenience function: read a line from the socket
+ * @param line The line read
+ * @param delim The line delimiter
+ * @return true if a line was read
+ */
+ bool GetNextLine(std::string& line, char delim = '\n');
+ /** Useful for implementing sendq exceeded */
+ size_t getSendQSize() const;
+
+ SendQueue& GetSendQ() { return sendq; }
+
+ /**
+ * Close the socket, remove from socket engine, etc
+ */
+ virtual void Close();
+
+ /** If writeblock is true then only close the socket if all data has been sent. Otherwise, close immediately. */
+ void Close(bool writeblock);
+
+ /** This ensures that close is called prior to destructor */
+ CullResult cull() CXX11_OVERRIDE;
+
+ /** Get the IOHook of a module attached to this socket
+ * @param mod Module whose IOHook to return
+ * @return IOHook belonging to the module or NULL if the module haven't attached an IOHook to this socket
+ */
+ IOHook* GetModHook(Module* mod) const;
+
+ /** Get the last IOHook attached to this socket
+ * @return The last IOHook attached to this socket or NULL if no IOHooks are attached
+ */
+ IOHook* GetLastHook() const;
+};
+/**
+ * BufferedSocket is an extendable socket class which modules
+ * can use for TCP socket support. It is fully integrated
+ * into InspIRCds socket loop and attaches its sockets to
+ * the core's instance of the SocketEngine class, meaning
+ * that all use is fully asynchronous.
+ *
+ * To use BufferedSocket, you must inherit a class from it.
+ */
+class CoreExport BufferedSocket : public StreamSocket
+{
+ public:
+ /** Timeout object or NULL
+ */
+ SocketTimeout* Timeout;
+
+ /**
+ * The state for this socket, either
+ * listening, connecting, connected
+ * or error.
+ */
+ BufferedSocketState state;
+
+ BufferedSocket();
+ /**
+ * This constructor is used to associate
+ * an existing connecting with an BufferedSocket
+ * class. The given file descriptor must be
+ * valid, and when initialized, the BufferedSocket
+ * will be placed in CONNECTED state.
+ */
+ BufferedSocket(int newfd);
+
+ /** Begin connection to the given address
+ * This will create a socket, register with socket engine, and start the asynchronous
+ * connection process. If an error is detected at this point (such as out of file descriptors),
+ * OnError will be called; otherwise, the state will become CONNECTING.
+ * @param dest Remote endpoint to connect to.
+ * @param bind Local endpoint to connect from.
+ * @param maxtime Time to wait for connection
+ */
+ void DoConnect(const irc::sockets::sockaddrs& dest, const irc::sockets::sockaddrs& bind, unsigned int maxtime);
+
+ /** This method is called when an outbound connection on your socket is
+ * completed.
+ */
+ virtual void OnConnected();
+
+ /** When there is data waiting to be read on a socket, the OnDataReady()
+ * method is called.
+ */
+ void OnDataReady() CXX11_OVERRIDE = 0;
+
+ /**
+ * When an outbound connection fails, and the attempt times out, you
+ * will receive this event. The method will trigger once maxtime
+ * seconds are reached (as given in the constructor) just before the
+ * socket's descriptor is closed. A failed DNS lookup may cause this
+ * event if the DNS server is not responding, as well as a failed
+ * connect() call, because DNS lookups are nonblocking as implemented by
+ * this class.
+ */
+ virtual void OnTimeout();
+
+ virtual ~BufferedSocket();
+ protected:
+ void OnEventHandlerWrite() CXX11_OVERRIDE;
+ BufferedSocketError BeginConnect(const irc::sockets::sockaddrs& dest, const irc::sockets::sockaddrs& bind, unsigned int timeout);
+};
+
+inline IOHook* StreamSocket::GetIOHook() const { return iohook; }
+inline void StreamSocket::DelIOHook() { iohook = NULL; }