P4 Switch + Deep Packet Inspection (DPI) example

[Topology]

H1-s1-H2

In this lab, I will run a DPI application on H3 (go-dpi example). H2 will run a HTTP server (but not at 80 port). H1 will use curl to get the webpage from H2. When the packet go through the S1, the packet will clone a copy and send it to H3 for Deep Packet Inspection. When H3 detects that this is a HTTP protocol packet, H3 will send a rule to s1 to block any packet to H2 HTTP server port.

Before that, please refer to https://github.com/mushorg/go-dpi to install go-dpi in your environment.

Also, remember to use 2 network cards in your environment. If you are using VirtualBox or VMware, please set these two NICs to NAT mode.

[basic.p4]

#include <core.p4>

#include <v1model.p4>

const bit<16> TYPE_IPV4 = 0x800;

typedef bit<9> egressSpec_t;

typedef bit<48> macAddr_t;

typedef bit<32> ip4Addr_t;

struct intrinsic_metadata_t {

bit<4> mcast_grp;

bit<4> egress_rid;

bit<16> mcast_hash;

bit<32> lf_field_list;

}

header ethernet_t {

bit<48> dstAddr;

bit<48> srcAddr;

bit<16> etherType;

}

header ipv4_t {

bit<4> version;

bit<4> ihl;

bit<8> diffserv;

bit<16> totalLen;

bit<16> identification;

bit<3> flags;

bit<13> fragOffset;

bit<8> ttl;

bit<8> protocol;

bit<16> hdrChecksum;

ip4Addr_t srcAddr;

ip4Addr_t dstAddr;

}

header tcp_t {

bit<16> srcPort;

bit<16> dstPort;

bit<32> seqNo;

bit<32> ackNo;

bit<4> dataOffset;

bit<3> res;

bit<3> ecn;

bit<6> ctrl;

bit<16> window;

bit<16> checksum;

bit<16> urgentPtr;

}

struct metadata {

@name(".intrinsic_metadata")

intrinsic_metadata_t intrinsic_metadata;

}

struct headers {

@name(".ethernet")

ethernet_t ethernet;

@name(".ipv4")

ipv4_t ipv4;

@name(".tcp")

tcp_t tcp;

}

parser ParserImpl(packet_in packet, out headers hdr, inout metadata meta, inout standard_metadata_t standard_metadata) {

@name(".start") state start {

transition parse_ethernet;

}

@name(".parse_ethernet") state parse_ethernet {

packet.extract(hdr.ethernet);

transition select(hdr.ethernet.etherType) {

TYPE_IPV4: parse_ipv4;

default: accept;

}

@name(".parse_ipv4")state parse_ipv4 {

packet.extract(hdr.ipv4);

transition select(hdr.ipv4.protocol) {

6: parse_tcp;

default: accept;

}

@name(".parse_tcp")state parse_tcp {

packet.extract(hdr.tcp);

transition accept;

}

control ingress(inout headers hdr, inout metadata meta, inout standard_metadata_t standard_metadata) {

action drop() {

mark_to_drop();

}

action forward(egressSpec_t port) {

standard_metadata.egress_spec = port;

}

table phy_forward {

key = {

standard_metadata.ingress_port: exact;

}

actions = {

forward;

drop;

}

size = 1024;

default_action = drop();

}

@name(".do_copy") action do_copy() {

clone3(CloneType.I2E, (bit<32>)32w250, { standard_metadata });

}

@name(".mycopy") table mycopy {

actions = {

do_copy;

}

size = 1;

default_action = do_copy();

}

apply {

mycopy.apply();

phy_forward.apply();

}

control egress(inout headers hdr, inout metadata meta, inout standard_metadata_t standard_metadata) {

action mydrop() {

mark_to_drop();

}

table filter {

key = {

hdr.ipv4.dstAddr: exact;

hdr.tcp.dstPort: exact;

}

actions = {

mydrop;

NoAction;

}

size = 1024;

default_action = NoAction();

}

apply {

filter.apply();

}

control DeparserImpl(packet_out packet, in headers hdr) {

apply {

packet.emit(hdr.ethernet);

packet.emit(hdr.ipv4);

packet.emit(hdr.tcp);

}

control verifyChecksum(inout headers hdr, inout metadata meta) {

apply {

}

control computeChecksum(inout headers hdr, inout metadata meta) {

apply {

}

V1Switch(ParserImpl(), verifyChecksum(), ingress(), egress(), computeChecksum(), DeparserImpl()) main;

[cmd.txt]

table_add phy_forward forward 1 => 2

table_add phy_forward forward 2 => 1

mirroring_add 250 3

[test_topo.py]

import os

from mininet.net import Mininet

from mininet.topo import Topo

from mininet.log import setLogLevel, info

from mininet.cli import CLI

from mininet.node import RemoteController

from mininet.link import Intf

from p4_mininet import P4Switch, P4Host

import argparse

from time import sleep

parser = argparse.ArgumentParser(description='Mininet demo')

parser.add_argument('--behavioral-exe', help='Path to behavioral executable',

type=str, action="store", required=False, default='simple_switch' )

parser.add_argument('--thrift-port', help='Thrift server port for table updates',

type=int, action="store", default=9090)

parser.add_argument('--num-hosts', help='Number of hosts to connect to switch',

type=int, action="store", default=2)

parser.add_argument('--mode', choices=['l2', 'l3'], type=str, default='l3')

parser.add_argument('--json', help='Path to JSON config file',

type=str, action="store", required=True)

parser.add_argument('--pcap-dump', help='Dump packets on interfaces to pcap files',

type=str, action="store", required=False, default=False)

args = parser.parse_args()

class SingleSwitchTopo(Topo):

def __init__(self, sw_path, json_path, thrift_port, pcap_dump, **opts):

Topo.__init__(self, **opts)

switch1 = self.addSwitch('s1', sw_path = sw_path, json_path = json_path, thrift_port = thrift_port,cls = P4Switch ,pcap_dump = pcap_dump)

host1 = self.addHost('h1', mac = '00:00:00:00:00:01')

host2 = self.addHost('h2', mac = '00:00:00:00:00:02')

host3 = self.addHost('h3', mac = '00:00:00:00:00:03')

self.addLink(host1, switch1, port1 = 0, port2 = 1)

self.addLink(host2, switch1, port1 = 0, port2 = 2)

self.addLink(host3, switch1, port1 = 0, port2 = 3)

def main():

topo = SingleSwitchTopo(args.behavioral_exe, args.json, args.thrift_port, args.pcap_dump)

#controller1 = RemoteController('controller1', ip = '10.108.148.148')

net = Mininet(topo = topo, host = P4Host, controller = None)

net.start()

h3=net.get('h3')

Intf('eth10', node=h3)

sleep(1)

print('\033[0;32m'),

print "Gotcha!"

print('\033[0m')

CLI(net)

try:

net.stop()

except:

print('\033[0;31m'),

print('Stop error! Trying sudo mn -c')

print('\033[0m')

os.system('sudo mn -c')

print('\033[0;32m'),

print ('Stop successfully!')

print('\033[0m')

if __name__ == '__main__':

setLogLevel('info')

main()

[start_test_topo.py]

import os

os.system("sudo python test_topo.py --behavioral-exe /home/vagrant/behavioral-model/targets/simple_switch/simple_switch --json basic.json")

[cmd_add.py]

import os

os.system('sudo /home/vagrant/behavioral-model/targets/simple_switch/simple_switch_CLI --thrift-port=9090 < cmd.txt')

[p4_mininet.py]

# 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.

from mininet.net import Mininet

from mininet.node import Switch, Host

from mininet.log import setLogLevel, info, error, debug

from mininet.moduledeps import pathCheck

from sys import exit

import os

import tempfile

import socket

class P4Host(Host):

def config(self, **params):

r = super(Host, self).config(**params)

self.defaultIntf().rename("eth0")

for off in ["rx", "tx", "sg"]:

cmd = "/sbin/ethtool --offload eth0 %s off" % off

self.cmd(cmd)

# disable IPv6

self.cmd("sysctl -w net.ipv6.conf.all.disable_ipv6=1")

self.cmd("sysctl -w net.ipv6.conf.default.disable_ipv6=1")

self.cmd("sysctl -w net.ipv6.conf.lo.disable_ipv6=1")

return r

def describe(self):

print "**********"

print self.name

print "default interface: %s\t%s\t%s" %(

self.defaultIntf().name,

self.defaultIntf().IP(),

self.defaultIntf().MAC()

)

print "**********"

class P4Switch(Switch):

"""P4 virtual switch"""

device_id = 0

def __init__(self, name, sw_path = None, json_path = None,

thrift_port = None,

pcap_dump = False,

log_console = False,

verbose = False,

device_id = None,

enable_debugger = False,

**kwargs):

Switch.__init__(self, name, **kwargs)

assert(sw_path)

assert(json_path)

# make sure that the provided sw_path is valid

pathCheck(sw_path)

# make sure that the provided JSON file exists

if not os.path.isfile(json_path):

error("Invalid JSON file.\n")

exit(1)

self.sw_path = sw_path

self.json_path = json_path

self.verbose = verbose

logfile = "/tmp/p4s.{}.log".format(self.name)

self.output = open(logfile, 'w')

self.thrift_port = thrift_port

self.pcap_dump = pcap_dump

self.enable_debugger = enable_debugger

self.log_console = log_console

if device_id is not None:

self.device_id = device_id

P4Switch.device_id = max(P4Switch.device_id, device_id)

else:

self.device_id = P4Switch.device_id

P4Switch.device_id += 1

self.nanomsg = "ipc:///tmp/bm-{}-log.ipc".format(self.device_id)

@classmethod

def setup(cls):

pass

def check_switch_started(self, pid):

"""While the process is running (pid exists), we check if the Thrift

server has been started. If the Thrift server is ready, we assume that

the switch was started successfully. This is only reliable if the Thrift

server is started at the end of the init process"""

while True:

if not os.path.exists(os.path.join("/proc", str(pid))):

return False

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

sock.settimeout(0.5)

result = sock.connect_ex(("localhost", self.thrift_port))

if result == 0:

return True

def start(self, controllers):

"Start up a new P4 switch"

info("Starting P4 switch {}.\n".format(self.name))

args = [self.sw_path]

for port, intf in self.intfs.items():

if not intf.IP():

args.extend(['-i', str(port) + "@" + intf.name])

#wuwzhs edit in 2017/11/10

#args.extend(['-i 3@veth1'])

if self.pcap_dump:

args.append("--pcap")

# args.append("--useFiles")

if self.thrift_port:

args.extend(['--thrift-port', str(self.thrift_port)])

if self.nanomsg:

args.extend(['--nanolog', self.nanomsg])

args.extend(['--device-id', str(self.device_id)])

P4Switch.device_id += 1

args.append(self.json_path)

if self.enable_debugger:

args.append("--debugger")

if self.log_console:

args.append("--log-console")

logfile = "/tmp/p4s.{}.log".format(self.name)

info(' '.join(args) + "\n")

pid = None

with tempfile.NamedTemporaryFile() as f:

# self.cmd(' '.join(args) + ' > /dev/null 2>&1 &')

self.cmd(' '.join(args) + ' >' + logfile + ' 2>&1 & echo $! >> ' + f.name)

pid = int(f.read())

debug("P4 switch {} PID is {}.\n".format(self.name, pid))

if not self.check_switch_started(pid):

error("P4 switch {} did not start correctly.\n".format(self.name))

exit(1)

info("P4 switch {} has been started.\n".format(self.name))

def stop(self):

"Terminate P4 switch."

self.output.flush()

self.cmd('kill %' + self.sw_path)

self.cmd('wait')

self.deleteIntfs()

def attach(self, intf):

"Connect a data port"

assert(0)

def detach(self, intf):

"Disconnect a data port"

assert(0)

[example_app.go] Note: 192.168.25.180 is the IP address of eth0 in my VM.

package main

import (

"flag"

"fmt"

"os"

"os/exec"

"os/signal"

"time"

"github.com/google/gopacket"

"github.com/google/gopacket/layers"

"github.com/google/gopacket/pcap"

"github.com/mushorg/go-dpi"

"github.com/mushorg/go-dpi/types"

"github.com/mushorg/go-dpi/utils"

)

func main() {

var (

count, idCount int

protoCounts map[types.Protocol]int

packetChannel <-chan gopacket.Packet

err error

)

protoCounts = make(map[types.Protocol]int)

filename := flag.String("filename", "godpi_example/dumps/http.cap", "File to read packets from")

device := flag.String("device", "", "Device to watch for packets")

flag.Parse()

if *device != "" {

// check if interface was given

handle, deverr := pcap.OpenLive(*device, 1024, false, time.Duration(-1))

if deverr != nil {

fmt.Println("Error opening device:", deverr)

return

}

packetChannel = gopacket.NewPacketSource(handle, handle.LinkType()).Packets()

} else if _, ferr := os.Stat(*filename); !os.IsNotExist(ferr) {

// check if file exists

packetChannel, err = utils.ReadDumpFile(*filename)

} else {

fmt.Println("File does not exist:", *filename)

return

}

initErrs := godpi.Initialize()

if len(initErrs) != 0 {

for _, err := range initErrs {

fmt.Println(err)

}

return

}

defer func() {

godpi.Destroy()

fmt.Println()

fmt.Println("Number of packets:", count)

fmt.Println("Number of packets identified:", idCount)

fmt.Println("Protocols identified:\n", protoCounts)

}()

signalChannel := make(chan os.Signal, 1)

signal.Notify(signalChannel, os.Interrupt)

intSignal := false

if err != nil {

fmt.Println("Error:", err)

return

}

count = 0

for packet := range packetChannel {

fmt.Printf("Packet #%d: ", count+1)

flow, isNew := godpi.GetPacketFlow(packet)

result := godpi.ClassifyFlow(flow)

if result.Protocol != types.Unknown {

fmt.Print(result)

idCount++

protoCounts[result.Protocol]++

} else {

fmt.Print("Could not identify")

}

if isNew {

fmt.Println(" (new flow)")

} else {

fmt.Println()

}

select {

case <-signalChannel:

fmt.Println("Received interrupt signal")

intSignal = true

default:

}

if intSignal {

break

}

count++

ipLayer := packet.Layer(layers.LayerTypeIPv4)

if ipLayer != nil {

fmt.Println("IPv4 layer detected.")

ip, _ := ipLayer.(*layers.IPv4)

fmt.Printf("From %s to %s\n", ip.SrcIP, ip.DstIP)

fmt.Println("Protocol: ", ip.Protocol)

fmt.Println()

}

tcpLayer := packet.Layer(layers.LayerTypeTCP)

if tcpLayer != nil {

fmt.Println("TCP layer detected.")

tcp, _ := tcpLayer.(*layers.TCP)

fmt.Printf("From port %d to %d\n", tcp.SrcPort, tcp.DstPort)

fmt.Println()

}

if result.Protocol=="HTTP" {

ip, _ := ipLayer.(*layers.IPv4)

tcp, _ := tcpLayer.(*layers.TCP)

a := fmt.Sprintf("echo \"table_add filter mydrop %s %d =>\" | sudo /home/vagrant/behavioral-model/targets/simple_switch/simple_switch_CLI --thrift-ip=192.168.25.180 --thrift-port=9090", ip.DstIP, tcp.DstPort)

fmt.Println(a)

out,err := exec.Command("bash","-c", a).Output()

if err != nil {

fmt.Printf("%s", err)

}

output := string(out[:])

fmt.Println(output)

}

[Execution]

Check whether there are two NICs in your VM. The IP in my VM is 192.168.25.180.