ostinato/server/device.cpp

272 lines
6.9 KiB
C++

/*
Copyright (C) 2015 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 "device.h"
#include "../common/emulproto.pb.h"
#include "devicemanager.h"
#include "packetbuffer.h"
#include <QHostAddress>
#include <qendian.h>
const int kBaseHex = 16;
const int kMaxVlan = 4;
/*
* NOTE:
* 1. Device Key is (VLANS + MAC) - is assumed to be unique for a device
* 2. Device clients/users (viz. DeviceManager) should take care when
* setting params that change the key, if the key is used elsewhere
* (e.g. in a hash)
*/
Device::Device(DeviceManager *deviceManager)
{
deviceManager_ = deviceManager;
for (int i = 0; i < kMaxVlan; i++)
vlan_[i] = 0;
numVlanTags_ = 0;
mac_ = 0;
ip4_ = 0;
ip4PrefixLength_ = 0;
clearKey();
}
void Device::setVlan(int index, quint16 vlan)
{
int ofs;
if ((index < 0) || (index >= kMaxVlan)) {
qWarning("%s: vlan index %d out of range (0 - %d)", __FUNCTION__,
index, kMaxVlan - 1);
return;
}
vlan_[index] = vlan;
ofs = index * sizeof(quint16);
key_[ofs] = vlan >> 8;
key_[ofs+1] = vlan & 0xff;
if (index >= numVlanTags_)
numVlanTags_ = index + 1;
}
void Device::setMac(quint64 mac)
{
int ofs = kMaxVlan * sizeof(quint16);
mac_ = mac;
memcpy(key_.data() + ofs, (char*)&mac, sizeof(mac));
}
void Device::setIp4(quint32 address, int prefixLength)
{
ip4_ = address;
ip4PrefixLength_ = prefixLength;
}
QString Device::config()
{
return QString("<vlans=%1/%2/%3/%4 mac=%5 ip4=%6/%7>")
.arg(vlan_[0]).arg(vlan_[1]).arg(vlan_[2]).arg(vlan_[3])
.arg(mac_, 12, kBaseHex, QChar('0'))
.arg(QHostAddress(ip4_).toString())
.arg(ip4PrefixLength_);
}
DeviceKey Device::key()
{
return key_;
}
void Device::clearKey()
{
key_.fill(0, kMaxVlan * sizeof(quint16) + sizeof(quint64));
}
int Device::encapSize()
{
// ethernet header + vlans
int size = 14 + 4*numVlanTags_;
return size;
}
void Device::encap(PacketBuffer *pktBuf, quint64 dstMac, quint16 type)
{
int ofs;
quint64 srcMac = mac_;
uchar *p = pktBuf->push(encapSize());
if (!p) {
qWarning("%s: failed to push %d bytes [0x%p, 0x%p]", __FUNCTION__,
encapSize(), pktBuf->head(), pktBuf->data());
goto _exit;
}
*(quint32*)(p ) = qToBigEndian(quint32(dstMac >> 16));
*(quint16*)(p + 4) = qToBigEndian(quint16(dstMac & 0xffff));
*(quint32*)(p + 6) = qToBigEndian(quint32(srcMac >> 16));
*(quint16*)(p + 10) = qToBigEndian(quint16(srcMac & 0xffff));
ofs = 12;
for (int i = 0; i < numVlanTags_; i++) {
*(quint32*)(p + ofs) = qToBigEndian(quint32((0x8100 << 16)|vlan_[i]));
ofs += 4;
}
*(quint16*)(p + ofs) = qToBigEndian(type);
ofs += 2;
Q_ASSERT(ofs == encapSize());
_exit:
return;
}
void Device::transmitPacket(PacketBuffer *pktBuf)
{
deviceManager_->transmitPacket(pktBuf);
}
// We expect pktBuf to point to EthType on entry
void Device::receivePacket(PacketBuffer *pktBuf)
{
quint16 ethType = qFromBigEndian<quint16>(pktBuf->data());
pktBuf->pull(2);
qDebug("%s: ethType 0x%x", __PRETTY_FUNCTION__, ethType);
switch(ethType)
{
case 0x0806: // ARP
receiveArp(pktBuf);
break;
case 0x0800: // IPv4
case 0x86dd: // IPv6
default:
break;
}
// FIXME: temporary hack till DeviceManager clones pbufs
pktBuf->push(2);
}
//
// Private Methods
//
void Device::receiveArp(PacketBuffer *pktBuf)
{
PacketBuffer *rspPkt;
uchar *pktData = pktBuf->data();
int offset = 0;
quint16 hwType, protoType;
quint8 hwAddrLen, protoAddrLen;
quint16 opCode;
quint64 srcMac, tgtMac;
quint32 srcIp, tgtIp;
// Extract tgtIp first to check quickly if this packet is for us or not
tgtIp = qFromBigEndian<quint32>(pktData + 24);
if (tgtIp != ip4_) {
qDebug("tgtIp %s is not me %s",
qPrintable(QHostAddress(tgtIp).toString()),
qPrintable(QHostAddress(ip4_).toString()));
return;
}
// Extract annd verify ARP packet contents
hwType = qFromBigEndian<quint16>(pktData + offset);
offset += 2;
if (hwType != 1) // Mac
goto _invalid_exit;
protoType = qFromBigEndian<quint16>(pktData + offset);
offset += 2;
if (protoType != 0x0800) // IPv4
goto _invalid_exit;
hwAddrLen = pktData[offset];
offset += 1;
if (hwAddrLen != 6)
goto _invalid_exit;
protoAddrLen = pktData[offset];
offset += 1;
if (protoAddrLen != 4)
goto _invalid_exit;
opCode = qFromBigEndian<quint16>(pktData + offset);
offset += 2;
srcMac = qFromBigEndian<quint32>(pktData + offset);
offset += 4;
srcMac = (srcMac << 16) | qFromBigEndian<quint16>(pktData + offset);
offset += 2;
srcIp = qFromBigEndian<quint32>(pktData + offset);
offset += 4;
tgtMac = qFromBigEndian<quint32>(pktData + offset);
offset += 4;
tgtMac = (tgtMac << 16) | qFromBigEndian<quint16>(pktData + offset);
offset += 2;
switch (opCode)
{
case 1: // ARP Request
rspPkt = new PacketBuffer;
rspPkt->reserve(encapSize());
pktData = rspPkt->put(28);
if (pktData) {
// HTYP, PTYP
*(quint32*)(pktData ) = qToBigEndian(quint32(0x00010800));
// HLEN, PLEN, OPER
*(quint32*)(pktData+ 4) = qToBigEndian(quint32(0x06040002));
// Source H/W Addr, Proto Addr
*(quint32*)(pktData+ 8) = qToBigEndian(quint32(mac_ >> 16));
*(quint16*)(pktData+12) = qToBigEndian(quint16(mac_ & 0xffff));
*(quint32*)(pktData+14) = qToBigEndian(ip4_);
// Target H/W Addr, Proto Addr
*(quint32*)(pktData+18) = qToBigEndian(quint32(srcMac >> 16));
*(quint16*)(pktData+22) = qToBigEndian(quint16(srcMac & 0xffff));
*(quint32*)(pktData+24) = qToBigEndian(srcIp);
}
encap(rspPkt, srcMac, 0x0806);
transmitPacket(rspPkt);
qDebug("Sent ARP Reply for srcIp/tgtIp=%s/%s",
qPrintable(QHostAddress(srcIp).toString()),
qPrintable(QHostAddress(tgtIp).toString()));
break;
case 2: // ARP Response
default:
break;
}
return;
_invalid_exit:
qWarning("Invalid ARP content");
return;
}