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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/
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <time.h>
#include <errno.h>
#include <sys/types.h>
#include "Constants.hpp"
#include "TcpSocket.hpp"
#include "SocketManager.hpp"
#ifdef __WINDOWS__
#include <WinSock2.h>
#include <WS2tcpip.h>
#include <Windows.h>
#else
#include <unistd.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <signal.h>
#endif
#define ZT_TCP_MAX_SENDQ_LENGTH (ZT_SOCKET_MAX_MESSAGE_LEN * 8)
namespace ZeroTier {
TcpSocket::~TcpSocket()
{
#ifdef __WINDOWS__
::closesocket(_sock);
#else
::close(_sock);
#endif
if (_outbuf)
::free(_outbuf);
}
bool TcpSocket::send(const InetAddress &to,const void *msg,unsigned int msglen)
{
if (msglen > ZT_SOCKET_MAX_MESSAGE_LEN)
return false; // message too big
if (!msglen)
return true; // sanity check
Mutex::Lock _l(_writeLock);
bool outputWasEnqueued = (_outptr != 0);
// Ensure that _outbuf is large enough
unsigned int newptr = _outptr + 5 + msglen;
if (newptr > _outbufsize) {
unsigned int newbufsize = _outbufsize;
while (newbufsize < newptr)
newbufsize += ZT_SOCKET_MAX_MESSAGE_LEN;
if (newbufsize > ZT_TCP_MAX_SENDQ_LENGTH)
return false; // cannot send, outbuf full
unsigned char *newbuf = (unsigned char *)::malloc(newbufsize);
if (!newbuf)
return false; // cannot send, no memory
_outbufsize = newbufsize;
if (_outbuf) {
memcpy(newbuf,_outbuf,_outptr);
::free(_outbuf);
}
_outbuf = newbuf;
}
_outbuf[_outptr++] = 0x17; // look like TLS data
_outbuf[_outptr++] = 0x03;
_outbuf[_outptr++] = 0x03; // look like TLS 1.2
_outbuf[_outptr++] = (unsigned char)((msglen >> 8) & 0xff);
_outbuf[_outptr++] = (unsigned char)(msglen & 0xff);
for(unsigned int i=0;i<msglen;++i)
_outbuf[_outptr++] = ((const unsigned char *)msg)[i];
if (!outputWasEnqueued) {
// If no output was enqueued before this, try to send() it and then
// start a queued write if any remains after that.
int n = (int)::send(_sock,_outbuf,_outptr,0);
if (n > 0)
memmove(_outbuf,_outbuf + (unsigned int)n,_outptr -= (unsigned int)n);
if (_outptr) {
_sm->startNotifyWrite(this);
_sm->whack();
}
} // else just leave in _outbuf[] to get written when stream is available for write
return true;
}
bool TcpSocket::notifyAvailableForRead(const SharedPtr<Socket> &self,SocketManager *sm)
{
unsigned char buf[65536];
// will not be called concurrently since only SocketManager::poll() calls this
int n = (int)::recv(_sock,buf,sizeof(buf),0);
if (n <= 0)
return false; // read error, stream probably closed
unsigned int p = _inptr,pl = 0;
for(int k=0;k<n;++k) {
_inbuf[p++] = buf[k];
if (p >= (int)sizeof(_inbuf))
return false; // read overrun, packet too large or invalid
if ((!pl)&&(p >= 5)) {
if (_inbuf[0] == 0x17) {
// fake TLS data frame, next two bytes are TLS version and are ignored
pl = (((unsigned int)_inbuf[3] << 8) | (unsigned int)_inbuf[4]) + 5;
} else return false; // in the future we may support fake TLS handshakes
}
if ((pl)&&(p >= pl)) {
Buffer<ZT_SOCKET_MAX_MESSAGE_LEN> data(_inbuf + 5,pl - 5);
sm->handleReceivedPacket(self,_remote,data);
memmove(_inbuf,_inbuf + pl,p - pl);
p -= pl;
pl = 0;
}
}
_inptr = p;
return true;
}
bool TcpSocket::notifyAvailableForWrite(const SharedPtr<Socket> &self,SocketManager *sm)
{
Mutex::Lock _l(_writeLock);
if (_connecting)
_connecting = false;
if (_outptr) {
int n = (int)::send(_sock,_outbuf,_outptr,0);
if (n < 0) {
switch(errno) {
#ifdef EBADF
case EBADF:
#endif
#ifdef EINVAL
case EINVAL:
#endif
#ifdef ENOTSOCK
case ENOTSOCK:
#endif
#ifdef ECONNRESET
case ECONNRESET:
#endif
#ifdef EPIPE
case EPIPE:
#endif
#ifdef ENETDOWN
case ENETDOWN:
#endif
return false;
default:
break;
}
} else if (n > 0)
memmove(_outbuf,_outbuf + (unsigned int)n,_outptr -= (unsigned int)n);
}
if (!_outptr)
sm->stopNotifyWrite(this);
return true;
}
} // namespace ZeroTier
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