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/**************************************************************************/
/* */
/* Copyright (c) 2001, 2009 NoMachine, http://www.nomachine.com/. */
/* */
/* NXCOMP, NX protocol compression and NX extensions to this software */
/* are copyright of NoMachine. Redistribution and use of the present */
/* software is allowed according to terms specified in the file LICENSE */
/* which comes in the source distribution. */
/* */
/* Check http://www.nomachine.com/licensing.html for applicability. */
/* */
/* NX and NoMachine are trademarks of Medialogic S.p.A. */
/* */
/* All rights reserved. */
/* */
/**************************************************************************/
#include "ServerReadBuffer.h"
#include "ServerChannel.h"
//
// Set the verbosity level.
//
#define PANIC
#define WARNING
#undef TEST
#undef DEBUG
unsigned int ServerReadBuffer::suggestedLength(unsigned int pendingLength)
{
//
// Always read all the data that
// is available.
//
int readable = transport_ -> readable();
unsigned int readLength = (readable == -1 ? 0 : (unsigned int) readable);
if (readLength < pendingLength)
{
readLength = pendingLength;
}
//
// Even if the readable data is not
// enough to make a complete message,
// resize the buffer to accomodate
// it all.
//
if (pendingLength < remaining_)
{
readLength = remaining_;
}
return readLength;
}
int ServerReadBuffer::locateMessage(const unsigned char *start,
const unsigned char *end,
unsigned int &controlLength,
unsigned int &dataLength,
unsigned int &trailerLength)
{
unsigned int size = end - start;
#ifdef TEST
*logofs << "ServerReadBuffer: Locating message for FD#"
<< transport_ -> fd() << " with " << size
<< " bytes.\n" << logofs_flush;
#endif
if (firstMessage_)
{
if (size < 8)
{
remaining_ = 8 - size;
#ifdef TEST
*logofs << "ServerReadBuffer: No message was located "
<< "with remaining " << remaining_ << ".\n"
<< logofs_flush;
#endif
return 0;
}
dataLength = 8 + (GetUINT(start + 6, bigEndian_) << 2);
}
else
{
if (size < 32)
{
remaining_ = 32 - size;
#ifdef TEST
*logofs << "ServerReadBuffer: No message was located "
<< "with remaining " << remaining_ << ".\n"
<< logofs_flush;
#endif
return 0;
}
if (*start == 1)
{
dataLength = 32 + (GetULONG(start + 4, bigEndian_) << 2);
}
else
{
dataLength = 32;
}
if (dataLength < 32)
{
#ifdef TEST
*logofs << "ServerReadBuffer: WARNING! Assuming length 32 "
<< "for suspicious message of length " << dataLength
<< ".\n" << logofs_flush;
#endif
dataLength = 32;
}
}
#ifdef TEST
*logofs << "ServerReadBuffer: Length of the next message is "
<< dataLength << ".\n" << logofs_flush;
#endif
if (size < dataLength)
{
remaining_ = dataLength - size;
#ifdef TEST
*logofs << "ServerReadBuffer: No message was located "
<< "with remaining " << remaining_ << ".\n"
<< logofs_flush;
#endif
return 0;
}
firstMessage_ = 0;
controlLength = 0;
trailerLength = 0;
remaining_ = 0;
#ifdef TEST
*logofs << "ServerReadBuffer: Located message with "
<< "remaining " << remaining_ << ".\n"
<< logofs_flush;
#endif
return 1;
}
//
// Check if the data already read contains a
// message matching the opcode and sequence,
// starting at the given offset.
//
unsigned char *ServerReadBuffer::peekMessage(unsigned int &offset, unsigned char opcode,
unsigned short sequence)
{
#ifdef TEST
*logofs << "ServerReadBuffer: Peeking message "
<< "for FD#" << transport_ -> fd() << " with size "
<< length_ << " offset " << offset << " opcode "
<< (unsigned int) opcode << " and sequence "
<< sequence << ".\n" << logofs_flush;
#endif
if (firstMessage_)
{
return NULL;
}
unsigned char *next = buffer_ + start_ + offset;
unsigned char *end = buffer_ + start_ + length_;
int found = 0;
while (end - next >= 32)
{
#ifdef DEBUG
*logofs << "ServerReadBuffer: Checking opcode "
<< (unsigned int) *next << " sequence "
<< GetUINT(next + 2, bigEndian_)
<< " at " << next - buffer_ + start_
<< ".\n" << logofs_flush;
#endif
if (*next == opcode && GetUINT(next + 2, bigEndian_) == sequence)
{
found = 1;
break;
}
else if (*next == 1)
{
next += (32 + (GetULONG(next + 4, bigEndian_) << 2));
}
else
{
next += 32;
}
}
offset = next - buffer_ + start_;
if (found == 1)
{
#ifdef TEST
*logofs << "ServerReadBuffer: Found message at "
<< "offset " << next - buffer_ + start_
<< ".\n" << logofs_flush;
#endif
return next;
}
#ifdef TEST
*logofs << "ServerReadBuffer: Quitting loop at "
<< "offset " << next - buffer_ + start_
<< ".\n" << logofs_flush;
#endif
return NULL;
}
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