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#include <fcntl.h>
#include <iostream.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include "Multiplexer.H"
#include "Channel.H"
#include "util.H"
extern int silent;
Multiplexer::Multiplexer(int proxyFD):
proxyFD_(proxyFD), proxyReadBuffer_(proxyFD), proxyInputChannel_(-1),
proxyOutputChannel_(-1)
{
for (unsigned int i = 0; i < MAX_CONNECTIONS; i++)
channels_[i] = 0;
}
Multiplexer::~Multiplexer()
{
for (unsigned int i = 0; i < MAX_CONNECTIONS; i++)
delete channels_[i];
}
// Add the file descriptors for this multiplexer's X connections
// to the supplied select set
void
Multiplexer::setSelectFDs(fd_set * fdSet, unsigned int &max)
{
int numFDsToSelect = max;
for (unsigned int i = 0; i < MAX_CONNECTIONS; i++)
if (channels_[i] != 0)
{
int nextFD = channelIDToFD(i);
FD_SET(nextFD, fdSet);
if (nextFD >= numFDsToSelect)
numFDsToSelect = nextFD + 1;
}
max = numFDsToSelect;
}
int
Multiplexer::handleSelect(int fd)
{
unsigned char controlMessages[9];
unsigned int controlMessagesLength = 0;
encodeBuffer_.reset();
if (fd == proxyFD_)
{
// Data arrived from peer proxy
if (!proxyReadBuffer_.doRead())
{
if (!silent)
{
cerr << "lost connection to peer proxy" << endl;
}
return 0;
}
const unsigned char *message;
unsigned int messageLength;
while ((message = proxyReadBuffer_.getMessage(messageLength)) != 0)
{
if ((messageLength == 3) && (message[0] == 0))
{
if (message[1] == (unsigned char) CTRL_NEW_CONNECTION)
{
int channelNum = (int) message[2];
if (!createNewConnectionFromProxy(channelNum))
{
controlMessages[controlMessagesLength++] = 0;
controlMessages[controlMessagesLength++] =
(unsigned char) CTRL_DROP_CONNECTION;
controlMessages[controlMessagesLength++] =
(unsigned char) channelNum;
}
}
else if (message[1] == (unsigned char) CTRL_DROP_CONNECTION)
{
int channelNum = (int) message[2];
if (((unsigned int) channelNum < MAX_CONNECTIONS) &&
(channels_[channelNum] != 0))
{
close(channelIDToFD(channelNum));
delete channels_[channelNum];
channels_[channelNum] = 0;
cleanupChannelFDMapping(channelNum);
}
}
else if (message[1] == (unsigned char) CTRL_SWITCH_CONNECTION)
{
proxyInputChannel_ = (int) message[2];
}
else
{
cerr << "invalid message from peer proxy!" << endl;
return 0;
}
}
else
{
int channelNum = proxyInputChannel_;
if ((channelNum >= 0) &&
((unsigned int) channelNum < MAX_CONNECTIONS) &&
(channels_[channelNum] != 0))
{
if (!channels_[channelNum]->doWrite(message, messageLength))
{
close(channelIDToFD(channelNum));
delete channels_[channelNum];
channels_[channelNum] = 0;
cleanupChannelFDMapping(channelNum);
controlMessages[controlMessagesLength++] = 0;
controlMessages[controlMessagesLength++] =
(unsigned char) CTRL_DROP_CONNECTION;
controlMessages[controlMessagesLength++] =
(unsigned char) channelNum;
}
}
}
}
}
else
{
// Data arrived from some X connection
int channelNum = fdToChannelID(fd);
if ((channelNum < 0) || (channels_[channelNum] == 0))
{
close(fd);
return 1;
}
// Let the channel object read all the new data from its
// file descriptor, isolate messages, compress those messages,
// and append the compressed form to the encodeBuffer_
if (!channels_[channelNum]->doRead(encodeBuffer_))
{
close(fd);
delete channels_[channelNum];
channels_[channelNum] = 0;
cleanupChannelFDMapping(channelNum);
// Send channel shutdown message to the peer proxy
controlMessages[controlMessagesLength++] = 0;
controlMessages[controlMessagesLength++] =
(unsigned char) CTRL_DROP_CONNECTION;
controlMessages[controlMessagesLength++] = (unsigned char) channelNum;
}
// Generate a control message to the peer proxy to tell it that
// we're now sending data for a different channel
else if (channelNum != proxyOutputChannel_)
{
proxyOutputChannel_ = channelNum;
controlMessages[controlMessagesLength++] = 0;
controlMessages[controlMessagesLength++] =
(unsigned char) CTRL_SWITCH_CONNECTION;
controlMessages[controlMessagesLength++] = (unsigned char) channelNum;
}
}
// write any outstanding control messages, followed by any outstanding
// compressed X messages, to proxyFD...
// This code assumes that "encodeBuffer_.getData()" actually references
// a location offset several bytes from the start of the buffer, so that
// the length header and any necessary control messages can be inserted
// in front of the data already in the buffer. (See EncodeBuffer.C.)
// This is an ugly hack, but it's the easiest way to encapsulate the
// header and message data together in a single write(2) call.
// (Experimentation has shown that doing separate writes for the
// header and the data causes the responsiveness of applications
// run over dxpc to deteriorate enormously.)
unsigned int dataLength = encodeBuffer_.getDataLength();
if (dataLength + controlMessagesLength != 0)
{
unsigned char temp[5];
unsigned int lengthLength = 0;
unsigned int length = dataLength;
while (length)
{
temp[lengthLength++] = (unsigned char) (length & 0x7f);
length >>= 7;
}
unsigned char *data = encodeBuffer_.getData();
unsigned char *outputMessage = data -
(controlMessagesLength + lengthLength);
unsigned int outputLength = dataLength + controlMessagesLength +
lengthLength;
unsigned char *nextDest = outputMessage;
for (unsigned int i = 0; i < controlMessagesLength; i++)
*nextDest++ = controlMessages[i];
for (int j = lengthLength - 1; j > 0; j--)
*nextDest++ = (temp[j] | 0x80);
if (lengthLength)
*nextDest++ = temp[0];
if ((dataLength != 0) &&
(proxyOutputChannel_ >= 0) &&
((unsigned int) proxyOutputChannel_ < MAX_CONNECTIONS) &&
(channels_[proxyOutputChannel_] != NULL))
channels_[proxyOutputChannel_]->recordFramingBits(
(controlMessagesLength + lengthLength) << 3);
if (WriteAll(proxyFD_, outputMessage, outputLength) <= 0)
return 0;
}
return 1;
}
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