blob: f5503cd4156eea3c2c02d208c7375fd21e514a67 [file] [log] [blame]
/*
* Copyright 2018-present Open Networking Foundation
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package devices
import (
"bytes"
"github.com/google/gopacket"
"github.com/google/gopacket/pcap"
"github.com/looplab/fsm"
"github.com/opencord/bbsim/internal/bbsim/packetHandlers"
"github.com/opencord/bbsim/internal/bbsim/types"
log "github.com/sirupsen/logrus"
"os/exec"
)
var (
nniLogger = log.WithFields(log.Fields{"module": "NNI"})
nniVeth = "nni"
upstreamVeth = "upstream"
dhcpServerIp = "192.168.254.1"
)
type Executor interface {
Command(name string, arg ...string) Runnable
}
type DefaultExecutor struct{}
func (d DefaultExecutor) Command(name string, arg ...string) Runnable {
return exec.Command(name, arg...)
}
type Runnable interface {
Run() error
}
var executor = DefaultExecutor{}
type NniPort struct {
// BBSIM Internals
ID uint32
// PON Attributes
OperState *fsm.FSM
Type string
}
func CreateNNI(olt *OltDevice) (NniPort, error) {
nniPort := NniPort{
ID: uint32(0),
OperState: getOperStateFSM(func(e *fsm.Event) {
oltLogger.Debugf("Changing NNI OperState from %s to %s", e.Src, e.Dst)
}),
Type: "nni",
}
createNNIPair(executor, olt)
return nniPort, nil
}
// sendNniPacket will send a packet out of the NNI interface.
// We will send upstream only DHCP packets and drop anything else
func sendNniPacket(packet gopacket.Packet) error {
if isDhcp := packetHandlers.IsDhcpPacket(packet); !isDhcp {
nniLogger.WithFields(log.Fields{
"packet": packet,
}).Trace("Dropping NNI packet as it's not DHCP")
}
packet, err := packetHandlers.PopDoubleTag(packet)
if err != nil {
nniLogger.WithFields(log.Fields{
"packet": packet,
}).Errorf("Can't remove double tags from packet: %v", err)
return err
}
handle, err := getVethHandler(nniVeth)
if err != nil {
return err
}
err = handle.WritePacketData(packet.Data())
if err != nil {
nniLogger.WithFields(log.Fields{
"packet": packet,
}).Errorf("Failed to send packet out of the NNI: %s", err)
return err
}
nniLogger.Infof("Sent packet out of NNI")
return nil
}
//createNNIBridge will create a veth bridge to fake the connection between the NNI port
//and something upstream, in this case a DHCP server.
//It is also responsible to start the DHCP server itself
func createNNIPair(executor Executor, olt *OltDevice) error {
if err := executor.Command("ip", "link", "add", nniVeth, "type", "veth", "peer", "name", upstreamVeth).Run(); err != nil {
nniLogger.Errorf("Couldn't create veth pair between %s and %s", nniVeth, upstreamVeth)
return err
}
if err := setVethUp(executor, nniVeth); err != nil {
return err
}
if err := setVethUp(executor, upstreamVeth); err != nil {
return err
}
if err := startDHCPServer(); err != nil {
return err
}
ch, err := listenOnVeth(nniVeth)
if err != nil {
return err
}
olt.nniPktInChannel = ch
return nil
}
// setVethUp is responsible to activate a virtual interface
func setVethUp(executor Executor, vethName string) error {
if err := executor.Command("ip", "link", "set", vethName, "up").Run(); err != nil {
nniLogger.Errorf("Couldn't change interface %s state to up: %v", vethName, err)
return err
}
return nil
}
var startDHCPServer = func() error {
if err := exec.Command("ip", "addr", "add", dhcpServerIp, "dev", upstreamVeth).Run(); err != nil {
nniLogger.Errorf("Couldn't assing ip %s to interface %s: %v", dhcpServerIp, upstreamVeth, err)
return err
}
if err := setVethUp(executor, upstreamVeth); err != nil {
return err
}
dhcp := "/usr/local/bin/dhcpd"
conf := "/etc/dhcp/dhcpd.conf" // copied in the container from configs/dhcpd.conf
logfile := "/tmp/dhcplog"
var stderr bytes.Buffer
cmd := exec.Command(dhcp, "-cf", conf, upstreamVeth, "-tf", logfile)
cmd.Stderr = &stderr
err := cmd.Run()
if err != nil {
nniLogger.Errorf("Fail to start DHCP Server: %s, %s", err, stderr.String())
return err
}
nniLogger.Info("Successfully activated DHCP Server")
return nil
}
func getVethHandler(vethName string) (*pcap.Handle, error) {
var (
device = vethName
snapshotLen int32 = 1518
promiscuous = false
timeout = pcap.BlockForever
)
handle, err := pcap.OpenLive(device, snapshotLen, promiscuous, timeout)
if err != nil {
nniLogger.Errorf("Can't retrieve handler for interface %s", vethName)
return nil, err
}
return handle, nil
}
var listenOnVeth = func(vethName string) (chan *types.PacketMsg, error) {
handle, err := getVethHandler(vethName)
if err != nil {
return nil, err
}
channel := make(chan *types.PacketMsg, 32)
go func() {
packetSource := gopacket.NewPacketSource(handle, handle.LinkType())
for packet := range packetSource.Packets() {
if !packetHandlers.IsIncomingPacket(packet) {
nniLogger.Tracef("Ignoring packet as it's going out")
continue
}
nniLogger.WithFields(log.Fields{
"packet": packet.Dump(),
}).Tracef("Received packet on NNI Port")
pkt := types.PacketMsg{
Pkt: packet,
}
channel <- &pkt
}
}()
return channel, nil
}