ostinato/server/device.cpp
2020-03-23 20:37:47 +05:30

438 lines
12 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 quint16 kEthTypeIp4 = 0x0800;
const quint16 kEthTypeIp6 = 0x86dd;
const int kIp6HdrLen = 40;
/*
* NOTE:
* 1. Device Key is (VLANS [without prio/cfi] + 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;
hasIp4_ = false;
hasIp6_ = false;
clearKey();
}
void Device::setVlan(int index, quint16 vlan, quint16 tpid)
{
int ofs;
if ((index < 0) || (index >= kMaxVlan)) {
qWarning("%s: vlan index %d out of range (0 - %d)", __FUNCTION__,
index, kMaxVlan - 1);
return;
}
vlan_[index] = (tpid << 16) | vlan;
ofs = index * sizeof(quint16);
key_[ofs] = (vlan >> 8) & 0x0f; // Vlan prio/cfi should not be part of key
key_[ofs+1] = vlan & 0xff;
if (index >= numVlanTags_)
numVlanTags_ = index + 1;
}
quint64 Device::mac()
{
return mac_;
}
void Device::setMac(quint64 mac)
{
int ofs = kMaxVlan * sizeof(quint16);
mac_ = mac & ~(0xffffULL << 48);
qToBigEndian(mac_, (uchar*)key_.data()+ofs);
}
void Device::setIp4(quint32 address, int prefixLength, quint32 gateway)
{
ip4_ = address;
ip4PrefixLength_ = prefixLength;
ip4Gateway_ = gateway;
hasIp4_ = true;
// Precalculate our mask 'n subnet to avoid doing so at pkt rx/tx time
ip4Mask_ = ~0 << (32 - ip4PrefixLength_);
ip4Subnet_ = ip4_ & ip4Mask_;
}
void Device::setIp6(UInt128 address, int prefixLength, UInt128 gateway)
{
ip6_ = address;
ip6PrefixLength_ = prefixLength;
ip6Gateway_ = gateway;
hasIp6_ = true;
// Precalculate our mask 'n subnet to avoid doing so at pkt rx/tx time
ip6Mask_ = ~UInt128(0, 0) << (128 - ip6PrefixLength_);
ip6Subnet_ = ip6_ & ip6Mask_;
}
void Device::getConfig(OstEmul::Device *deviceConfig)
{
for (int i = 0; i < numVlanTags_; i++)
deviceConfig->add_vlan(vlan_[i]);
deviceConfig->set_mac(mac_);
if (hasIp4_) {
deviceConfig->set_ip4(ip4_);
deviceConfig->set_ip4_prefix_length(ip4PrefixLength_);
deviceConfig->set_ip4_default_gateway(ip4Gateway_);
}
if (hasIp6_) {
deviceConfig->mutable_ip6()->set_hi(ip6_.hi64());
deviceConfig->mutable_ip6()->set_lo(ip6_.lo64());
deviceConfig->set_ip6_prefix_length(ip6PrefixLength_);
deviceConfig->mutable_ip6_default_gateway()->set_hi(ip6Gateway_.hi64());
deviceConfig->mutable_ip6_default_gateway()->set_lo(ip6Gateway_.lo64());
}
}
QString Device::config()
{
QString config;
for (int i = 0; i < numVlanTags_; i++) {
config.append(i == 0 ? "vlans=" : "|");
config.append(
(vlan_[i] >> 16) != kVlanTpid ?
QString("0x%1-%2")
.arg(vlan_[i] >> 16, 4, kBaseHex, QChar('0'))
.arg(vlan_[i] & 0xFFFF) :
QString("%1")
.arg(vlan_[i] & 0xFFFF));
}
config.append(QString(" mac=%1")
.arg(mac_, 12, kBaseHex, QChar('0')));
if (hasIp4_)
config.append(QString(" ip4=%1/%2")
.arg(QHostAddress(ip4_).toString())
.arg(ip4PrefixLength_));
if (hasIp6_)
config.append(QString(" ip6=%1/%2")
.arg(QHostAddress(ip6_.toArray()).toString())
.arg(ip6PrefixLength_));
return config;
}
DeviceKey Device::key()
{
return key_;
}
void Device::clearKey()
{
key_.fill(0, kMaxVlan * sizeof(quint16) + sizeof(quint64));
}
/*
void Device::receivePacket(PacketBuffer *pktBuf)
{
// XXX: Pure Virtual: Subclass should implement
// We expect pktBuf to point to EthType on entry
}
*/
void Device::transmitPacket(PacketBuffer *pktBuf)
{
deviceManager_->transmitPacket(pktBuf);
}
void Device::resolveGateway()
{
if (hasIp4_ && !isResolved(ip4Gateway_))
sendArpRequest(ip4Gateway_);
if (hasIp6_ && !isResolved(ip6Gateway_))
sendNeighborSolicit(ip6Gateway_);
}
// Resolve the Neighbor IP address for this to-be-transmitted pktBuf
// We expect pktBuf to point to EthType on entry
void Device::resolveNeighbor(PacketBuffer *pktBuf)
{
quint16 ethType = qFromBigEndian<quint16>(pktBuf->data());
pktBuf->pull(2);
qDebug("%s: ethType 0x%x", __PRETTY_FUNCTION__, ethType);
switch(ethType)
{
case kEthTypeIp4: // IPv4
if (hasIp4_)
sendArpRequest(pktBuf);
break;
case kEthTypeIp6: // IPv6
if (hasIp6_)
sendNeighborSolicit(pktBuf);
break;
default:
break;
}
// FIXME: temporary hack till DeviceManager clones pbufs
pktBuf->push(2);
}
/*
void Device::clearNeighbors(Device::NeighborSet set)
{
// XXX: Pure virtual: Subclass should implement
}
// Append this device's neighbors to the list
void Device::getNeighbors(OstEmul::DeviceNeighborList* neighbors)
{
// XXX: Subclass should implement
}
*/
// Are we the source of the given packet?
// We expect pktBuf to point to EthType on entry
bool Device::isOrigin(const PacketBuffer *pktBuf)
{
const uchar *pktData = pktBuf->data();
quint16 ethType = qFromBigEndian<quint16>(pktData);
qDebug("%s: ethType 0x%x", __PRETTY_FUNCTION__, ethType);
pktData += 2;
// We know only about IP packets - adjust for ethType length (2 bytes)
// when checking that we have a complete IP header
if ((ethType == kEthTypeIp4) && hasIp4_) { // IPv4
int ipHdrLen = (pktData[0] & 0x0F) << 2;
quint32 srcIp;
if (pktBuf->length() < (ipHdrLen+2)) {
qDebug("incomplete IPv4 header: expected %d, actual %d",
ipHdrLen, pktBuf->length());
return false;
}
srcIp = qFromBigEndian<quint32>(pktData + ipHdrLen - 8);
qDebug("%s: pktSrcIp/selfIp = 0x%x/0x%x", __FUNCTION__, srcIp, ip4_);
return (srcIp == ip4_);
}
else if ((ethType == kEthTypeIp6) && hasIp6_) { // IPv6
UInt128 srcIp;
if (pktBuf->length() < (kIp6HdrLen+2)) {
qDebug("incomplete IPv6 header: expected %d, actual %d",
kIp6HdrLen, pktBuf->length()-2);
return false;
}
srcIp = qFromBigEndian<UInt128>(pktData + 8);
qDebug("%s: pktSrcIp6/selfIp6 = %llx-%llx/%llx-%llx", __FUNCTION__,
srcIp.hi64(), srcIp.lo64(), ip6_.hi64(), ip6_.lo64());
return (srcIp == ip6_);
}
return false;
}
// Return the mac address corresponding to the dstIp of the given packet
// We expect pktBuf to point to EthType on entry
quint64 Device::neighborMac(const PacketBuffer *pktBuf)
{
quint64 mac = 0;
const uchar *pktData = pktBuf->data();
quint16 ethType = qFromBigEndian<quint16>(pktData);
qDebug("%s: ethType 0x%x", __PRETTY_FUNCTION__, ethType);
pktData += 2;
// We know only about IP packets
if ((ethType == kEthTypeIp4) && hasIp4_) { // IPv4
int ipHdrLen = (pktData[0] & 0x0F) << 2;
quint32 dstIp, tgtIp;
if (pktBuf->length() < ipHdrLen) {
qDebug("incomplete IPv4 header: expected %d, actual %d",
ipHdrLen, pktBuf->length());
return mac;
}
dstIp = qFromBigEndian<quint32>(pktData + ipHdrLen - 4);
if ((dstIp & 0xF0000000) == 0xE0000000) { // Mcast IP?
mac = (quint64(0x01005e) << 24) | (dstIp & 0x7FFFFF);
qDebug("mcast dst %08x, mac: %012llx", dstIp, mac);
}
else {
tgtIp = ((dstIp & ip4Mask_) == ip4Subnet_) ? dstIp : ip4Gateway_;
mac = arpLookup(tgtIp);
qDebug("tgtIp: %08x, mac: %012llx", tgtIp, mac);
}
}
else if ((ethType == kEthTypeIp6) && hasIp6_) { // IPv6
UInt128 dstIp, tgtIp;
if (pktBuf->length() < (kIp6HdrLen+2)) {
qDebug("incomplete IPv6 header: expected %d, actual %d",
kIp6HdrLen, pktBuf->length()-2);
return mac;
}
dstIp = qFromBigEndian<UInt128>(pktData + 24);
if (dstIp.toArray()[0] == 0xFF) { // Mcast IP?
mac = (quint64(0x3333) << 32) | (dstIp.lo64() & 0xFFFFFFFF);
qDebug("mcast dst %s, mac: %012llx",
qPrintable(QHostAddress(dstIp.toArray()).toString()),
mac);
}
else {
tgtIp = ((dstIp & ip6Mask_) == ip6Subnet_) ? dstIp : ip6Gateway_;
mac = ndpLookup(tgtIp);
qDebug("tgtIp %s, mac: %012llx",
qPrintable(QHostAddress(dstIp.toArray()).toString()),
mac);
}
}
return mac;
}
/*
quint64 Device::arpLookup(quint32 ip)
{
// XXX: Pure virtual: Subclass should implement
}
quint64 Device::ndpLookup(UInt128 ip)
{
// XXX: Pure virtual: Subclass should implement
}
*/
// Send ARP request for the IPv4 packet in pktBuf
// pktBuf points to start of IP header
void Device::sendArpRequest(PacketBuffer *pktBuf)
{
uchar *pktData = pktBuf->data();
int ipHdrLen = (pktData[0] & 0x0F) << 2;
quint32 dstIp, tgtIp;
if (pktBuf->length() < ipHdrLen) {
qDebug("incomplete IPv4 header: expected %d, actual %d",
ipHdrLen, pktBuf->length());
return;
}
dstIp = qFromBigEndian<quint32>(pktData + ipHdrLen - 4);
tgtIp = ((dstIp & ip4Mask_) == ip4Subnet_) ? dstIp : ip4Gateway_;
if (!isResolved(tgtIp))
sendArpRequest(tgtIp);
}
// Send NS for the IPv6 packet in pktBuf
// caller is responsible to check that pktBuf originates from this device
// pktBuf should point to start of IP header
void Device::sendNeighborSolicit(PacketBuffer *pktBuf)
{
uchar *pktData = pktBuf->data();
UInt128 dstIp, tgtIp;
if (pktBuf->length() < kIp6HdrLen) {
qDebug("incomplete IPv6 header: expected %d, actual %d",
kIp6HdrLen, pktBuf->length());
return;
}
dstIp = qFromBigEndian<UInt128>(pktData + 24);
tgtIp = ((dstIp & ip6Mask_) == ip6Subnet_) ? dstIp : ip6Gateway_;
if (!isResolved(tgtIp))
sendNeighborSolicit(tgtIp);
}
bool Device::isResolved(quint32 ip)
{
return arpLookup(ip) > 0;
}
bool Device::isResolved(UInt128 ip)
{
return ndpLookup(ip) > 0;
}
//
// Protected Methods
//
/*
void Device::sendArpRequest(quint32 tgtIp)
{
// XXX: Pure virtual: Subclass should implement
}
void Device::sendNeighborSolicit(UInt128 tgtIp)
{
// XXX: Pure virtual: Subclass should implement
}
*/
bool operator<(const DeviceKey &a1, const DeviceKey &a2)
{
int i = 0;
while (i < a1.size()) {
if (uchar(a1.at(i)) < uchar(a2.at(i)))
return true;
if (uchar(a1.at(i)) > uchar(a2.at(i)))
return false;
i++;
}
return false;
}