ostinato/common/pdmlreader.cpp
2011-04-09 17:13:49 +05:30

507 lines
14 KiB
C++

/*
Copyright (C) 2011 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 "pdmlreader.h"
#include "abstractprotocol.h"
#include "hexdump.pb.h"
#include "pcapfileformat.h"
#include "streambase.h"
#include "pdml_p.h" // TODO: Remove
PdmlReader::PdmlReader(OstProto::StreamConfigList *streams)
{
//gPdmlReader = this;
pcap_ = NULL;
streams_ = streams;
currentStream_ = NULL;
prevStream_ = NULL;
stop_ = NULL;
factory_.insert("hexdump", PdmlUnknownProtocol::createInstance);
factory_.insert("geninfo", PdmlGenInfoProtocol::createInstance);
factory_.insert("frame", PdmlFrameProtocol::createInstance);
factory_.insert("arp", PdmlArpProtocol::createInstance);
factory_.insert("eth", PdmlEthProtocol::createInstance);
factory_.insert("http", PdmlTextProtocol::createInstance);
factory_.insert("icmp", PdmlIcmpProtocol::createInstance);
factory_.insert("icmpv6", PdmlIcmp6Protocol::createInstance);
factory_.insert("igmp", PdmlIgmpProtocol::createInstance);
factory_.insert("ieee8021ad", PdmlSvlanProtocol::createInstance);
factory_.insert("imap", PdmlTextProtocol::createInstance);
factory_.insert("ip", PdmlIp4Protocol::createInstance);
factory_.insert("ipv6", PdmlIp6Protocol::createInstance);
factory_.insert("llc", PdmlLlcProtocol::createInstance);
factory_.insert("nntp", PdmlTextProtocol::createInstance);
factory_.insert("pop", PdmlTextProtocol::createInstance);
factory_.insert("rtsp", PdmlTextProtocol::createInstance);
factory_.insert("sdp", PdmlTextProtocol::createInstance);
factory_.insert("sip", PdmlTextProtocol::createInstance);
factory_.insert("smtp", PdmlTextProtocol::createInstance);
factory_.insert("tcp", PdmlTcpProtocol::createInstance);
factory_.insert("udp", PdmlUdpProtocol::createInstance);
factory_.insert("udplite", PdmlUdpProtocol::createInstance);
factory_.insert("vlan", PdmlVlanProtocol::createInstance);
}
PdmlReader::~PdmlReader()
{
}
bool PdmlReader::read(QIODevice *device, PcapFileFormat *pcap, bool *stop)
{
setDevice(device);
pcap_ = pcap;
stop_ = stop;
while (!atEnd())
{
readNext();
if (isStartElement())
{
if (name() == "pdml")
readPdml();
else
raiseError("Not a pdml file!");
}
}
if (error() && (errorString() != "USER-CANCEL"))
{
qDebug("Line %lld", lineNumber());
qDebug("Col %lld", columnNumber());
qDebug("%s", errorString().toAscii().constData());
return false;
}
return true;
}
// TODO: use a temp pool to avoid a lot of new/delete
PdmlProtocol* PdmlReader::allocPdmlProtocol(QString protoName)
{
// If protoName is not known, we use a hexdump
if (!factory_.contains(protoName))
protoName = "hexdump";
return (*(factory_.value(protoName)))();
}
void PdmlReader::freePdmlProtocol(PdmlProtocol *proto)
{
delete proto;
}
bool PdmlReader::isDontCareProto()
{
Q_ASSERT(isStartElement() && name() == "proto");
QStringRef protoName = attributes().value("name");
if (protoName.isEmpty() || (protoName == "expert"))
return true;
return false;
}
void PdmlReader::skipElement()
{
Q_ASSERT(isStartElement());
qDebug("skipping element - <%s>",
name().toString().toAscii().constData());
while (!atEnd())
{
readNext();
if (isEndElement())
break;
if (isStartElement())
skipElement();
}
}
void PdmlReader::readPdml()
{
Q_ASSERT(isStartElement() && name() == "pdml");
packetCount_ = 1;
while (!atEnd())
{
readNext();
if (isEndElement())
break;
if (isStartElement())
{
if (name() == "packet")
readPacket();
else
skipElement();
}
}
}
void PdmlReader::readPacket()
{
PcapFileFormat::PcapPacketHeader pktHdr;
Q_ASSERT(isStartElement() && name() == "packet");
qDebug("%s: packetNum = %d", __FUNCTION__, packetCount_);
skipUntilEnd_ = false;
// XXX: we play dumb and convert each packet to a stream, for now
prevStream_ = currentStream_;
currentStream_ = streams_->add_stream();
currentStream_->mutable_stream_id()->set_id(packetCount_);
currentStream_->mutable_core()->set_is_enabled(true);
// Set to a high number; will get reset to correct value during parse
currentStream_->mutable_core()->set_frame_len(16384); // FIXME: Hard coding!
expPos_ = 0;
if (pcap_)
pcap_->readPacket(pktHdr, pktBuf_);
while (!atEnd())
{
readNext();
if (isEndElement())
break;
if (isStartElement())
{
if (skipUntilEnd_)
skipElement();
else if (name() == "proto")
readProto();
else if (name() == "field")
readField(NULL, NULL); // TODO: top level field!!!!
else
skipElement();
}
}
currentStream_->mutable_core()->set_name(""); // FIXME
// If trailing bytes are missing, add those from the pcap
if ((expPos_ < pktBuf_.size()) && pcap_)
{
OstProto::Protocol *proto = currentStream_->add_protocol();
OstProto::HexDump *hexDump = proto->MutableExtension(
OstProto::hexDump);
proto->mutable_protocol_id()->set_id(
OstProto::Protocol::kHexDumpFieldNumber);
qDebug("adding trailing %d bytes starting from %d",
pktBuf_.size() - expPos_, expPos_);
hexDump->set_content(pktBuf_.constData() + expPos_,
pktBuf_.size() - expPos_);
hexDump->set_pad_until_end(false);
}
packetCount_++;
emit progress(int(characterOffset()*100/device()->size())); // in %
if (prevStream_)
prevStream_->mutable_control()->CopyFrom(currentStream_->control());
if (stop_ && *stop_)
raiseError("USER-CANCEL");
}
void PdmlReader::readProto()
{
PdmlProtocol *pdmlProto = NULL;
OstProto::Protocol *pbProto = NULL;
Q_ASSERT(isStartElement() && name() == "proto");
QString protoName;
int pos = -1;
int size = -1;
if (!attributes().value("name").isEmpty())
protoName = attributes().value("name").toString();
if (!attributes().value("pos").isEmpty())
pos = attributes().value("pos").toString().toInt();
if (!attributes().value("size").isEmpty())
size = attributes().value("size").toString().toInt();
qDebug("proto: %s, pos = %d, expPos_ = %d, size = %d",
protoName.toAscii().constData(), pos, expPos_, size);
// This is a heuristic to skip protocols which are not part of
// this frame, but of a reassembled segment spanning several frames
// 1. Proto starting pos is 0, but we've already seen some protocols
// 2. Protocol Size exceeds frame length
if (((pos == 0) && (currentStream_->protocol_size() > 0))
|| ((pos + size) > int(currentStream_->core().frame_len())))
{
skipElement();
return;
}
if (isDontCareProto())
{
skipElement();
return;
}
// if we detect a gap between subsequent protocols, we "fill-in"
// with a "hexdump" from the pcap
if (pos > expPos_ && pcap_)
{
appendHexDumpProto(expPos_, pos - expPos_);
expPos_ = pos;
}
// for unknown protocol, read a hexdump from the pcap
if (!factory_.contains(protoName) && pcap_)
{
int size = -1;
if (!attributes().value("size").isEmpty())
size = attributes().value("size").toString().toInt();
// Check if this proto is a subset of previous proto - if so, do nothing
if ((pos >= 0) && (size > 0) && ((pos + size) <= expPos_))
{
qDebug("subset proto");
skipElement();
return;
}
if (pos >= 0 && size > 0
&& ((pos + size) <= pktBuf_.size()))
{
appendHexDumpProto(pos, size);
expPos_ += size;
skipElement();
return;
}
}
pdmlProto = appendPdmlProto(protoName, &pbProto);
qDebug("%s: preProtocolHandler(expPos = %d)",
protoName.toAscii().constData(), expPos_);
pdmlProto->preProtocolHandler(protoName, attributes(), expPos_, pbProto,
currentStream_);
while (!atEnd())
{
readNext();
if (isEndElement())
break;
if (isStartElement())
{
if (name() == "proto")
{
// an embedded proto
qDebug("embedded proto: %s\n", attributes().value("name")
.toString().toAscii().constData());
if (isDontCareProto())
{
skipElement();
continue;
}
// if we are in the midst of processing a protocol, we
// end it prematurely before we start processing the
// embedded protocol
//
// XXX: pdmlProto may be NULL for a sequence of embedded protos
if (pdmlProto)
{
int endPos = -1;
if (!attributes().value("pos").isEmpty())
endPos = attributes().value("pos").toString().toInt();
pdmlProto->prematureEndHandler(endPos, pbProto,
currentStream_);
pdmlProto->postProtocolHandler(pbProto, currentStream_);
StreamBase s;
s.protoDataCopyFrom(*currentStream_);
expPos_ = s.frameProtocolLength(0);
}
readProto();
pdmlProto = NULL;
pbProto = NULL;
}
else if (name() == "field")
{
if ((protoName == "fake-field-wrapper") &&
(attributes().value("name") == "tcp.segments"))
{
skipElement();
qDebug("[skipping reassembled tcp segments]");
skipUntilEnd_ = true;
continue;
}
if (pdmlProto == NULL)
{
pdmlProto = appendPdmlProto(protoName, &pbProto);
qDebug("%s: preProtocolHandler(expPos = %d)",
protoName.toAscii().constData(), expPos_);
pdmlProto->preProtocolHandler(protoName, attributes(),
expPos_, pbProto, currentStream_);
}
readField(pdmlProto, pbProto);
}
else
skipElement();
}
}
// Close-off current protocol
if (pdmlProto)
{
pdmlProto->postProtocolHandler(pbProto, currentStream_);
freePdmlProtocol(pdmlProto);
StreamBase s;
s.protoDataCopyFrom(*currentStream_);
expPos_ = s.frameProtocolLength(0);
}
}
void PdmlReader::readField(PdmlProtocol *pdmlProto,
OstProto::Protocol *pbProto)
{
Q_ASSERT(isStartElement() && name() == "field");
// fields with "hide='yes'" are informational and should be skipped
if (attributes().value("hide") == "yes")
{
skipElement();
return;
}
QString fieldName = attributes().value("name").toString();
qDebug(" fieldName:%s", fieldName.toAscii().constData());
pdmlProto->fieldHandler(fieldName, attributes(), pbProto, currentStream_);
while (!atEnd())
{
readNext();
if (isEndElement())
break;
if (isStartElement())
{
if (name() == "proto")
{
// Since we are in the midst of processing a protocol, we
// end it prematurely before we start processing the
// embedded protocol
//
int endPos = -1;
if (!attributes().value("pos").isEmpty())
endPos = attributes().value("pos").toString().toInt();
pdmlProto->prematureEndHandler(endPos, pbProto,
currentStream_);
pdmlProto->postProtocolHandler(pbProto, currentStream_);
StreamBase s;
s.protoDataCopyFrom(*currentStream_);
expPos_ = s.frameProtocolLength(0);
readProto();
}
else if (name() == "field")
readField(pdmlProto, pbProto);
else
skipElement();
}
}
}
void PdmlReader::appendHexDumpProto(int offset, int size)
{
OstProto::Protocol *proto = currentStream_->add_protocol();
OstProto::HexDump *hexDump = proto->MutableExtension(OstProto::hexDump);
proto->mutable_protocol_id()->set_id(
OstProto::Protocol::kHexDumpFieldNumber);
qDebug("filling in gap of %d bytes starting from %d", size, offset);
hexDump->set_content(pktBuf_.constData() + offset, size);
hexDump->set_pad_until_end(false);
}
PdmlProtocol* PdmlReader::appendPdmlProto(const QString &protoName,
OstProto::Protocol **pbProto)
{
PdmlProtocol* pdmlProto = allocPdmlProtocol(protoName);
Q_ASSERT(pdmlProto != NULL);
int protoId = pdmlProto->ostProtoId();
if (protoId > 0) // Non-Base Class
{
OstProto::Protocol *proto = currentStream_->add_protocol();
proto->mutable_protocol_id()->set_id(protoId);
const google::protobuf::Reflection *msgRefl = proto->GetReflection();
const google::protobuf::FieldDescriptor *fieldDesc =
msgRefl->FindKnownExtensionByNumber(protoId);
// TODO: if !fDesc
// init default values of all fields in protocol
msgRefl->MutableMessage(proto, fieldDesc);
*pbProto = proto;
qDebug("%s: name = %s", __FUNCTION__,
protoName.toAscii().constData());
}
else
*pbProto = NULL;
return pdmlProto;
}