/*
* InspIRCd -- Internet Relay Chat Daemon
*
* Copyright (C) 2021 Dominic Hamon
* Copyright (C) 2020-2023 Sadie Powell <sadie@sadiepowell.dev>
* Copyright (C) 2019 Robby <robby@chatbelgie.be>
* Copyright (C) 2013, 2016 Attila Molnar <attilamolnar@hush.com>
*
* 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
class StreamSocket;
class IOHookProvider
: public std::enable_shared_from_this<IOHookProvider>
, public ServiceProvider
{
const bool middlehook;
public:
enum Type
{
IOH_UNKNOWN,
IOH_SSL
};
const Type type;
/** Constructor
* @param mod Module that owns the IOHookProvider
* @param Name Name of the provider
* @param hooktype One of IOHookProvider::Type
* @param middle True if the IOHook instances created by this hook are subclasses of IOHookMiddle, false otherwise
*/
IOHookProvider(Module* mod, const std::string& Name, Type hooktype = IOH_UNKNOWN, bool middle = false)
: ServiceProvider(mod, Name, SERVICE_IOHOOK)
, middlehook(middle)
, type(hooktype)
{
}
/** Check if the IOHook provided can appear in the non-last position of a hook chain.
* That is the case if and only if the IOHook instances created are subclasses of IOHookMiddle.
* @return True if the IOHooks provided are subclasses of IOHookMiddle
*/
bool IsMiddle() const { return middlehook; }
/** Called when the provider should hook an incoming connection and act as being on the server-side of the connection.
* This occurs when a bind block has a hook configured and the listener accepts a connection.
* @param sock Socket to hook
* @param client Client IP address and port
* @param server Server IP address and port
*/
virtual void OnAccept(StreamSocket* sock, const irc::sockets::sockaddrs& client, const irc::sockets::sockaddrs& server) = 0;
/** Called when the provider should hook an outgoing connection and act as being on the client side of the connection.
* @param sock Socket to hook
*/
virtual void OnConnect(StreamSocket* sock) = 0;
};
class IOHook
: public Cullable
{
public:
/** The IOHookProvider for this hook, contains information about the hook,
* such as the module providing it and the hook type.
*/
std::shared_ptr<IOHookProvider> prov;
/** Constructor
* @param provider IOHookProvider that creates this object
*/
IOHook(const std::shared_ptr<IOHookProvider>& provider)
: prov(provider)
{
}
/** Determines whether this I/O hook is ready to send and receive data. */
virtual bool IsHookReady() const { return true; }
/**
* Called when the hooked socket has data to write, or when the socket engine returns it as writable
* @param sock Hooked socket
* @param sendq Send queue to send data from
* @return 1 if the sendq has been completely emptied, 0 if there is
* still data to send, and -1 if there was an error
*/
virtual ssize_t OnStreamSocketWrite(StreamSocket* sock, StreamSocket::SendQueue& sendq) = 0;
/** Called immediately before the hooked socket is closed. When this event is called, shutdown()
* has not yet been called on the socket.
* @param sock Hooked socket
*/
virtual void OnStreamSocketClose(StreamSocket* sock) = 0;
/**
* Called when the hooked socket has data to read
* @param sock Hooked socket
* @param recvq The receive queue that new data should be appended to
* @return 1 if new data has been read, 0 if no new data is ready (but the
* socket is still connected), -1 if there was an error or close
*/
virtual ssize_t OnStreamSocketRead(StreamSocket* sock, std::string& recvq) = 0;
/** Sends a ping to the remote client to check whether it is still connected.
* @param sock Hooked socket
* @return True if the client was pinged; otherwise, false.
*/
virtual bool Ping(StreamSocket* sock) { return false; }
};
class IOHookMiddle
: public IOHook
{
/** Data already processed by the IOHook waiting to go down the chain
*/
StreamSocket::SendQueue sendq;
/** Data waiting to go up the chain
*/
std::string precvq;
/** Next IOHook in the chain
*/
IOHook* nexthook = nullptr;
protected:
/** Get all queued up data which has not yet been passed up the hook chain
* @return RecvQ containing the data
*/
std::string& GetRecvQ() { return precvq; }
/** Get all queued up data which is ready to go down the hook chain
* @return SendQueue containing all data waiting to go down the hook chain
*/
StreamSocket::SendQueue& GetSendQ() { return sendq; }
public:
/** Constructor
* @param provider IOHookProvider that creates this object
*/
IOHookMiddle(const std::shared_ptr<IOHookProvider>& provider)
: IOHook(provider)
{
}
/** @copydoc IOHook::OnStreamSocketClose */
void OnStreamSocketClose(StreamSocket* sock) override { }
/** Get all queued up data which is ready to go down the hook chain
* @return SendQueue containing all data waiting to go down the hook chain
*/
const StreamSocket::SendQueue& GetSendQ() const { return sendq; }
/** Get the next IOHook in the chain
* @return Next hook in the chain or NULL if this is the last hook
*/
IOHook* GetNextHook() const { return nexthook; }
/** Set the next hook in the chain
* @param hook Hook to set as the next hook in the chain
*/
void SetNextHook(IOHook* hook) { nexthook = hook; }
/** Check if a hook is capable of being the non-last hook in a hook chain and if so, cast it to an IOHookMiddle object.
* @param hook IOHook to check
* @return IOHookMiddle referring to the same hook or NULL
*/
static IOHookMiddle* ToMiddleHook(IOHook* hook)
{
if (hook->prov->IsMiddle())
return static_cast<IOHookMiddle*>(hook);
return nullptr;
}
friend class StreamSocket;
};
