Bunch of work in progress on new socket multiplexer and plumbing for TCP jailbreaking... Don't try to build, won't yet.

node/TcpSocket.hpp

@@ -0,0 +1,113 @@
+/*
+ * 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 "Socket.hpp"
+#include "Mutex.hpp"
+#include "Utils.hpp"
+
+namespace ZeroTier {
+
+class SocketManager;
+
+#define ZT_TCP_SENDQ_LENGTH 16384
+#define ZT_TCP_MAX_MESSAGE_LENGTH 2048
+
+/**
+ * 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 isOpen() const;
+	virtual bool send(const InetAddress &to,const void *msg,unsigned int msglen);
+
+	/**
+	 * @return Remote TCP endpoint address
+	 */
+	inline const InetAddress &remote() const { return _remote; }
+
+protected:
+	virtual bool notifyAvailableForRead(const SharedPtr<Socket> &self,SocketManager *sm);
+	virtual bool notifyAvailableForWrite(const SharedPtr<Socket> &self,SocketManager *sm);
+
+private:
+#ifdef __WINDOWS__
+	TcpSocket(SOCKET sock,bool connecting,const InetAddress &remote) :
+#endif
+	TcpSocket(int sock,bool connecting,const InetAddress &remote) :
+#else
+		Socket(ZT_SOCKET_TYPE_TCP,sock),
+		_lastReceivedData(Utils::now()),
+		_inptr(0),
+		_outptr(0),
+		_connecting(connecting),
+		_remote(remote),
+		_lock()
+	{
+	}
+
+	unsigned char _outbuf[ZT_TCP_SENDQ_LENGTH];
+	unsigned char _inbuf[ZT_TCP_MAX_MESSAGE_LENGTH];
+	uint64_t _lastReceivedData; // updated whenever data is received, checked directly by SocketManager for stale TCP cleanup
+	unsigned int _inptr;
+	unsigned int _outptr;
+	bool _connecting; // manipulated directly by SocketManager, true if connect() is in progress
+	InetAddress _remote;
+	Mutex _lock;
+};
+
+}; // namespace ZeroTier
+
+#endif