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/*
* ZeroTier One - Global Peer to Peer Ethernet
* Copyright (C) 2011-2014 ZeroTier Networks LLC
*
* This program 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, either version 3 of the License, or
* (at your option) any later version.
*
* 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/>.
*
* --
*
* ZeroTier may be used and distributed under the terms of the GPLv3, which
* are available at: http://www.gnu.org/licenses/gpl-3.0.html
*
* If you would like to embed ZeroTier into a commercial application or
* redistribute it in a modified binary form, please contact ZeroTier Networks
* LLC. Start here: http://www.zerotier.com/
*/
#ifndef ZT_TCPSOCKET_HPP
#define ZT_TCPSOCKET_HPP
#include <stdint.h>
#include "InetAddress.hpp"
#include "Mutex.hpp"
#include "Utils.hpp"
#include "Socket.hpp"
namespace ZeroTier {
class SocketManager;
/**
* A TCP socket encapsulating ZeroTier packets over a TCP stream connection
*
* This implements a simple packet encapsulation that is designed to look like
* a TLS connection. It's not a TLS connection, but it sends TLS format record
* headers. It could be extended in the future to implement a fake TLS
* handshake.
*
* At the moment, each packet is just made to look like TLS application data:
* <[1] TLS content type> - currently 0x17 for "application data"
* <[1] TLS major version> - currently 0x03 for TLS 1.2
* <[1] TLS minor version> - currently 0x03 for TLS 1.2
* <[2] payload length> - 16-bit length of payload in bytes
* <[...] payload> - Message payload
*
* The primary purpose of TCP sockets is to work over ports like HTTPS(443),
* allowing users behind particularly fascist firewalls to at least reach
* ZeroTier's supernodes. UDP is the preferred method of communication as
* encapsulating L2 and L3 protocols over TCP is inherently inefficient
* due to double-ACKs. So TCP is only used as a fallback.
*/
class TcpSocket : public Socket
{
friend class SharedPtr<Socket>;
friend class SocketManager;
public:
virtual ~TcpSocket();
virtual bool send(const InetAddress &to,const void *msg,unsigned int msglen);
protected:
#ifdef __WINDOWS__
TcpSocket(SocketManager *sm,SOCKET s,bool c,const InetAddress &r) :
#else
TcpSocket(SocketManager *sm,int s,bool c,const InetAddress &r) :
#endif
Socket(Socket::ZT_SOCKET_TYPE_TCP,s),
_lastActivity(Utils::now()),
_sm(sm),
_outbuf((unsigned char *)0),
_outptr(0),
_outbufsize(0),
_inptr(0),
_connecting(c),
_remote(r)
{
//printf("!!! TCP SOCKET CREATED @%.16llx to %s\r\n",(unsigned long long)this,_remote.toString().c_str());
}
virtual bool notifyAvailableForRead(const SharedPtr<Socket> &self,SocketManager *sm);
virtual bool notifyAvailableForWrite(const SharedPtr<Socket> &self,SocketManager *sm);
private:
unsigned char _inbuf[ZT_SOCKET_MAX_MESSAGE_LEN];
uint64_t _lastActivity; // updated whenever data is received, checked directly by SocketManager for stale TCP cleanup
SocketManager *_sm;
unsigned char *_outbuf;
unsigned int _outptr;
unsigned int _outbufsize;
unsigned int _inptr;
bool _connecting; // manipulated directly by SocketManager, true if connect() is in progress
InetAddress _remote;
Mutex _writeLock;
};
} // namespace ZeroTier
#endif
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