ostinato/common/gre.cpp
2021-01-09 13:15:26 +05:30

464 lines
12 KiB
C++

/*
Copyright (C) 2021 Srivats P.
This file is part of "Ostinato"
This 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/>
*/
#include "gre.h"
GreProtocol::GreProtocol(StreamBase *stream, AbstractProtocol *parent)
: AbstractProtocol(stream, parent)
{
}
GreProtocol::~GreProtocol()
{
}
AbstractProtocol* GreProtocol::createInstance(StreamBase *stream,
AbstractProtocol *parent)
{
return new GreProtocol(stream, parent);
}
quint32 GreProtocol::protocolNumber() const
{
return OstProto::Protocol::kGreFieldNumber;
}
void GreProtocol::protoDataCopyInto(OstProto::Protocol &protocol) const
{
protocol.MutableExtension(OstProto::gre)->CopyFrom(data);
protocol.mutable_protocol_id()->set_id(protocolNumber());
}
void GreProtocol::protoDataCopyFrom(const OstProto::Protocol &protocol)
{
if (protocol.protocol_id().id() == protocolNumber() &&
protocol.HasExtension(OstProto::gre))
data.MergeFrom(protocol.GetExtension(OstProto::gre));
}
QString GreProtocol::name() const
{
return QString("General Routing Encapsulation Protocol");
}
QString GreProtocol::shortName() const
{
return QString("GRE");
}
AbstractProtocol::ProtocolIdType GreProtocol::protocolIdType() const
{
return ProtocolIdEth;
}
quint32 GreProtocol::protocolId(ProtocolIdType type) const
{
switch(type)
{
case ProtocolIdIp: return 47;
default:break;
}
return AbstractProtocol::protocolId(type);
}
int GreProtocol::fieldCount() const
{
return gre_fieldCount;
}
/*!
TODO Return the number of frame fields for your protocol. A frame field
is a field which has the FrameField flag set \n
If your protocol has different sets of fields based on a OpCode/Type field
(e.g. icmp), you MUST re-implement this function; however, if your protocol
has a fixed set of frame fields always, you don't need to reimplement this
method - the base class implementation will do the right thing
*/
int GreProtocol::frameFieldCount() const
{
int count = 4; // mandatory fields - flags, rsvd0, version, protocol
if (data.flags() & GRE_FLAG_CKSUM)
count += 2; // checksum, rsvd1
if (data.flags() & GRE_FLAG_KEY)
count++;
if (data.flags() & GRE_FLAG_SEQ)
count++;
return count;
}
AbstractProtocol::FieldFlags GreProtocol::fieldFlags(int index) const
{
AbstractProtocol::FieldFlags flags;
flags = AbstractProtocol::fieldFlags(index);
if (index == gre_checksum)
flags |= CksumField;
return flags;
}
/*!
TODO: Edit this function to return the data for each field
See AbstractProtocol::fieldData() for more info
*/
QVariant GreProtocol::fieldData(int index, FieldAttrib attrib,
int streamIndex) const
{
switch (index)
{
case gre_flags:
{
switch(attrib)
{
case FieldName:
return QString("Flags");
case FieldValue:
return data.flags();
case FieldTextValue:
{
QString fstr;
fstr.append("Cksum:");
fstr.append(data.flags() & GRE_FLAG_CKSUM ? "Y" : "N");
fstr.append(" Key:");
fstr.append(data.flags() & GRE_FLAG_KEY ? "Y" : "N");
fstr.append(" Seq:");
fstr.append(data.flags() & GRE_FLAG_SEQ ? "Y" : "N");
return fstr;
}
case FieldFrameValue:
return QByteArray(1, char(data.flags()));
case FieldBitSize:
return 4;
default:
break;
}
break;
}
case gre_rsvd0:
{
switch(attrib)
{
case FieldName:
return QString("Reserved0");
case FieldValue:
return data.rsvd0();
case FieldTextValue:
return QString("%1").arg(data.rsvd0());
case FieldFrameValue:
{
QByteArray fv;
fv.resize(2);
qToBigEndian(quint16(data.rsvd0()), (uchar*)fv.data());
return fv;
}
case FieldBitSize:
return 9;
default:
break;
}
break;
}
case gre_version:
{
switch(attrib)
{
case FieldName:
return QString("Version");
case FieldValue:
return data.version();
case FieldFrameValue:
return QByteArray(1, char(data.version()));
case FieldTextValue:
return QString("%1").arg(data.version());
case FieldBitSize:
return 3;
default:
break;
}
break;
}
case gre_protocol:
{
quint16 protocol = payloadProtocolId(ProtocolIdEth);
switch(attrib)
{
case FieldName:
return QString("Protocol");
case FieldValue:
return protocol;
case FieldFrameValue:
{
QByteArray fv;
fv.resize(2);
qToBigEndian(protocol, (uchar*) fv.data());
return fv;
}
case FieldTextValue:
return QString("0x%1").arg(
protocol, 4, BASE_HEX, QChar('0'));;
default:
break;
}
break;
}
case gre_checksum:
{
if ((data.flags() & GRE_FLAG_CKSUM) == 0)
return QVariant();
switch(attrib)
{
case FieldName:
return QString("Checksum");
case FieldBitSize:
return 16;
default:
break;
}
quint16 cksum = 0;
if (data.flags() & GRE_FLAG_CKSUM) {
quint32 sum = 0;
cksum = protocolFrameCksum(streamIndex, CksumIp);
sum += (quint16) ~cksum;
cksum = protocolFramePayloadCksum(streamIndex, CksumIp);
sum += (quint16) ~cksum;
while (sum >> 16)
sum = (sum & 0xFFFF) + (sum >> 16);
cksum = (~sum) & 0xFFFF;
}
switch(attrib)
{
case FieldValue:
return cksum;
case FieldFrameValue:
{
QByteArray fv;
fv.resize(2);
qToBigEndian(cksum, (uchar*) fv.data());
return fv;
}
case FieldTextValue:
return QString("0x%1").arg(
cksum, 4, BASE_HEX, QChar('0'));;
default:
break;
}
break;
}
case gre_rsvd1:
{
if ((data.flags() & GRE_FLAG_CKSUM) == 0)
return QVariant();
switch(attrib)
{
case FieldName:
return QString("Reserved1");
case FieldValue:
return data.rsvd1();
case FieldTextValue:
return QString("%1").arg(data.rsvd1());
case FieldFrameValue:
{
QByteArray fv;
fv.resize(2);
qToBigEndian((quint16) data.rsvd1(), (uchar*) fv.data());
return fv;
}
default:
break;
}
break;
}
case gre_key:
{
if ((data.flags() & GRE_FLAG_KEY) == 0)
return QVariant();
switch(attrib)
{
case FieldName:
return QString("Key");
case FieldValue:
return data.key();
case FieldTextValue:
return QString("0x%1").arg(data.key(), 8, BASE_HEX, QChar('0'));
case FieldFrameValue:
{
QByteArray fv;
fv.resize(4);
qToBigEndian((quint32) data.key(), (uchar*) fv.data());
return fv;
}
default:
break;
}
break;
}
case gre_sequence:
{
if ((data.flags() & GRE_FLAG_SEQ) == 0)
return QVariant();
switch(attrib)
{
case FieldName:
return QString("Sequence Number");
case FieldValue:
return data.sequence_num();
case FieldTextValue:
return QString("%1").arg(data.sequence_num());
case FieldFrameValue:
{
QByteArray fv;
fv.resize(4);
qToBigEndian((quint32) data.sequence_num(), (uchar*) fv.data());
return fv;
}
default:
break;
}
break;
}
default:
qFatal("%s: unimplemented case %d in switch", __PRETTY_FUNCTION__,
index);
break;
}
return AbstractProtocol::fieldData(index, attrib, streamIndex);
}
/*!
TODO: Edit this function to set the data for each field
See AbstractProtocol::setFieldData() for more info
*/
bool GreProtocol::setFieldData(int index, const QVariant &value,
FieldAttrib attrib)
{
bool isOk = false;
if (attrib != FieldValue)
goto _exit;
switch (index)
{
case gre_flags:
{
uint flags = value.toUInt(&isOk);
if (isOk)
data.set_flags(flags);
break;
}
case gre_rsvd0:
{
uint rsvd0 = value.toUInt(&isOk);
if (isOk)
data.set_rsvd0(rsvd0);
break;
}
case gre_version:
{
uint ver = value.toUInt(&isOk);
if (isOk)
data.set_version(ver);
break;
}
case gre_protocol:
{
uint proto = value.toUInt(&isOk);
if (isOk)
data.set_protocol_type(proto);
break;
}
case gre_checksum:
{
uint csum = value.toUInt(&isOk);
if (isOk)
data.set_checksum(csum);
break;
}
case gre_rsvd1:
{
uint rsvd1 = value.toUInt(&isOk);
if (isOk)
data.set_rsvd1(rsvd1);
break;
}
case gre_key:
{
uint key = value.toUInt(&isOk);
if (isOk)
data.set_key(key);
break;
}
case gre_sequence:
{
uint seq = value.toUInt(&isOk);
if (isOk)
data.set_sequence_num(seq);
break;
}
default:
qFatal("%s: unimplemented case %d in switch", __PRETTY_FUNCTION__,
index);
break;
}
_exit:
return isOk;
}
/*!
TODO: Return the protocol frame size in bytes\n
If your protocol has a fixed size - you don't need to reimplement this; the
base class implementation is good enough
*/
int GreProtocol::protocolFrameSize(int /*streamIndex*/) const
{
int size = 4; // mandatory fields - flags, rsvd0, version, protocol
if (data.flags() & GRE_FLAG_CKSUM)
size += 4;
if (data.flags() & GRE_FLAG_KEY)
size += 4;
if (data.flags() & GRE_FLAG_SEQ)
size += 4;
return size;
}