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merge develop into master #21

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JakeHillion merged 149 commits from develop into master 2021-05-12 00:22:59 +01:00
Conversation 0 Commits 149 Files Changed 37 +2434 -355
37 changed files with 2434 additions and 355 deletions
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34
.drone.yml
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@ -1,12 +1,18 @@
---
kind: pipeline
type: docker
name: default
steps:
- name: format
image: golang:1.16
commands:
- bash -c "gofmt -l . | wc -l | cmp -s <(echo 0) || (gofmt -l . && exit 1)"
- name: install
image: golang:1.15
image: golang:1.16
environment:
GOPROXY: http://10.20.0.25:3142|direct
GOPROXY: http://containers.internal.hillion.co.uk:3142,direct
volumes:
- name: cache
path: /go
@ -14,7 +20,7 @@ steps:
- go test -i ./...
- name: test
image: golang:1.15
image: golang:1.16
volumes:
- name: cache
path: /go
@ -22,7 +28,7 @@ steps:
- go test ./...
- name: build (debian)
image: golang:1.15-buster
image: golang:1.16-buster
when:
event:
- push
@ -30,7 +36,10 @@ steps:
- name: cache
path: /go
commands:
- go build
- GOOS=linux GOARCH=amd64 go build -o linux_amd64
- GOOS=linux GOARCH=arm GOARM=7 go build -o linux_arm_v7
- GOOS=freebsd GOARCH=amd64 go build -o freebsd_amd64
- GOOS=freebsd GOARCH=arm64 go build -o freebsd_arm64_v8a
- name: upload
image: minio/mc
@ -42,9 +51,18 @@ steps:
SECRET_KEY:
from_secret: s3_secret_key
commands:
- mc alias set s3 http://10.20.0.25:3900 $${ACCESS_KEY} $${SECRET_KEY}
- mc cp mpbl3p s3/dissertation/binaries/debian/${DRONE_BRANCH}
- mc alias set s3 https://s3.us-west-001.backblazeb2.com $${ACCESS_KEY} $${SECRET_KEY}
- mc cp linux_amd64 s3/dissertation/binaries/debian/${DRONE_BRANCH}_linux_amd64
- mc cp linux_arm_v7 s3/dissertation/binaries/debian/${DRONE_BRANCH}_linux_arm_v7
- mc cp freebsd_amd64 s3/dissertation/binaries/debian/${DRONE_BRANCH}_freebsd_amd64
- mc cp freebsd_arm64_v8a s3/dissertation/binaries/debian/${DRONE_BRANCH}_freebsd_arm64_v8a
volumes:
- name: cache
temp: {}
temp: { }
---
kind: signature
hmac: 7960420c7d02f9bce56d6429b612676d24cbe1d1608cf44a77da9afc411eccb8
...

2
.gitignore vendored
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@ -1,4 +1,4 @@
config.ini
*.conf
logs/
# Created by https://www.toptal.com/developers/gitignore/api/intellij+all,go

129
README.md
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@ -4,15 +4,130 @@
### Linux
#### Policy Based Routing
ip route flush 11
ip route add table 11 to 1.1.1.0/24 dev eth1
ip rule add from 1.1.1.4 table 11 priority 11
ip route flush table 10
ip route add table 10 to 1.1.1.0/24 dev eth1
ip rule add from 1.1.1.4 table 10 priority 10
ip route flush 10
ip route add table 10 to 1.1.1.0/24 dev eth2
ip rule add from 1.1.1.5 table 10 priority 10
ip route flush table 11
ip route add table 11 to 1.1.1.0/24 dev eth2
ip rule add from 1.1.1.5 table 11 priority 11
#### ARP Flux
sysctl -w net.ipv4.conf.all.arp_announce=1
sysctl -w net.ipv4.conf.all.arp_ignore=2
sysctl -w net.ipv4.conf.all.arp_ignore=1
See http://kb.linuxvirtualserver.org/wiki/Using_arp_announce/arp_ignore_to_disable_ARP
### Setup Scripts
These are functional setup scripts that make the application run as intended on Linux.
### Remote Portal
#### Pre-Start
#!/bin/bash
set -e
## Set up variables
REMOTE_PORTAL_ADDRESS=A.B.C.D
## IPv4 Forwarding
sysctl -w net.ipv4.ip_forward=1
sysctl -w net.ipv4.conf.eth0.proxy_arp=1
## Transfer the local routing table to a much lower priority
(ip rule show | grep '20:') > /dev/null || ip rule add from all table local priority 20
ip rule del priority 0 2> /dev/null || true
## Ports to route locally
### MPBL3P
ip rule del priority 1 2> /dev/null || true
ip rule add to "$REMOTE_PORTAL_ADDRESS" dport 1234 table local priority 1
### SSH
ip rule del priority 2 2> /dev/null || true
ip rule add to "$REMOTE_PORTAL_ADDRESS" dport 22 table local priority 2
#### Post-Start
#!/bin/bash
set -e
## Set up variables
REMOTE_PORTAL_ADDRESS=A.B.C.D
## Tunnel addr/up
ip addr add 172.19.152.2/31 dev nc0
ip link set up nc0
# Route packets to the interface but not for nc via the tunnel
ip route flush table 19
ip route add table 19 to "$REMOTE_PORTAL_ADDRESS" via 172.19.152.3 dev nc0
ip rule del priority 19 2> /dev/null || true
ip rule add to "$REMOTE_PORTAL_ADDRESS" table 19 priority 19
### Local Portal
#### Pre-Start
#!/bin/bash
set -e
## Set up variables
GATEWAY_INTERFACE=eth0
GATEWAY_ADDRESS=10.36.12.1
## Fix ARP
sysctl -w net.ipv4.conf.all.arp_announce=1
sysctl -w net.ipv4.conf.all.arp_ignore=1
## IPv4 Forwarding
sysctl -w net.ipv4.ip_forward=1
## Gateway Interface Setup
ip addr flush dev "$GATEWAY_INTERFACE"
ip addr add "$GATEWAY_ADDRESS"/32 dev "$GATEWAY_INTERFACE"
ip link set up "$GATEWAY_INTERFACE"
## Per-Interface Routing Tables
### 10.10.0.0/24
ip route flush table 10
ip route add table 10 default via 10.10.0.1
ip rule del priority 10 2> /dev/null || true
ip rule add from 10.10.0.0/24 table 10 priority 10
### 192.168.0.0/24
ip route flush table 11
ip route add table 11 default via 192.168.0.1
ip rule del priority 11 2> /dev/null || true
ip rule add from 192.168.0.0/24 table 11 priority 11
#### Post-Start
#!/bin/bash
set -e
## Set up variables
REMOTE_PORTAL_ADDRESS=A.B.C.D
GATEWAY_INTERFACE=eth0
## Tunnel Address and Enable
ip addr add 172.19.152.3/31 dev nc0
ip link set up nc0
## Route Outbound Packets Correctly
ip route flush table 20
ip route add table 20 default via 172.19.152.2 dev nc0
ip rule del priority 20 2> /dev/null || true
ip rule add from "$REMOTE_PORTAL_ADDRESS" iif "$GATEWAY_INTERFACE" table 20 priority 20
## Route Inbound Packets Correctly
ip route flush table 21
ip route add table 21 to "$REMOTE_PORTAL_ADDRESS" dev "$GATEWAY_INTERFACE"
ip rule del priority 21 2> /dev/null || true
ip rule add to "$REMOTE_PORTAL_ADDRESS" table 21 priority 21
#### Client
Connect to `GATEWAY_INTERFACE` and set the IP to `REMOTE_PORTAL_ADDRESS`/32 with a gateway of `GATEWAY_ADDRESS`.

153
config/builder.go
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@ -1,48 +1,57 @@
package config
import (
"context"
"encoding/base64"
"fmt"
"mpbl3p/crypto"
"mpbl3p/crypto/sharedkey"
"mpbl3p/proxy"
"mpbl3p/tcp"
"mpbl3p/tun"
"mpbl3p/udp"
"mpbl3p/udp/congestion"
"time"
)
// TODO: Delete this code as soon as an alternative is available
type UselessMac struct{}
func (UselessMac) CodeLength() int {
return 0
}
func (UselessMac) Generate([]byte) []byte {
return nil
}
func (u UselessMac) Verify([]byte, []byte) error {
return nil
}
func (c Configuration) Build() (*proxy.Proxy, error) {
func (c Configuration) Build(ctx context.Context, source proxy.Source, sink proxy.Sink) (*proxy.Proxy, error) {
p := proxy.NewProxy(0)
p.Generator = UselessMac{}
if c.Host.InterfaceName == "" {
c.Host.InterfaceName = "nc%d"
var g func() proxy.MacGenerator
var v func() proxy.MacVerifier
switch c.Host.Crypto {
case "None":
g = func() proxy.MacGenerator { return crypto.None{} }
v = func() proxy.MacVerifier { return crypto.None{} }
case "Blake2s":
key, err := base64.StdEncoding.DecodeString(c.Host.SharedKey)
if err != nil {
return nil, err
}
if _, err := sharedkey.NewBlake2s(key); err != nil {
return nil, err
}
g = func() proxy.MacGenerator {
g, _ := sharedkey.NewBlake2s(key)
return g
}
v = func() proxy.MacVerifier {
v, _ := sharedkey.NewBlake2s(key)
return v
}
}
ss, err := tun.NewTun(c.Host.InterfaceName, 1500)
if err != nil {
return nil, err
}
p.Source = ss
p.Sink = ss
p.Source = source
p.Sink = sink
for _, peer := range c.Peers {
switch peer.Method {
case "TCP":
err := buildTcp(p, peer)
if err != nil {
if err := buildTcp(ctx, p, peer, g, v); err != nil {
return nil, err
}
case "UDP":
if err := buildUdp(ctx, p, peer, g, v); err != nil {
return nil, err
}
}
@ -51,20 +60,82 @@ func (c Configuration) Build() (*proxy.Proxy, error) {
return p, nil
}
func buildTcp(p *proxy.Proxy, peer Peer) error {
if peer.RemoteHost != "" {
f, err := tcp.InitiateFlow(
fmt.Sprintf("%s:", peer.LocalHost),
fmt.Sprintf("%s:%d", peer.RemoteHost, peer.RemotePort),
)
p.AddConsumer(f)
p.AddProducer(f, UselessMac{})
return err
func buildTcp(ctx context.Context, p *proxy.Proxy, peer Peer, g func() proxy.MacGenerator, v func() proxy.MacVerifier) error {
var laddr func() string
if peer.LocalPort == 0 {
laddr = func() string { return fmt.Sprintf("%s:", peer.GetLocalHost()) }
} else {
laddr = func() string { return fmt.Sprintf("%s:%d", peer.GetLocalHost(), peer.LocalPort) }
}
err := tcp.NewListener(p, fmt.Sprintf("%s:%d", peer.LocalHost, peer.LocalPort), UselessMac{})
if peer.RemoteHost != "" {
f, err := tcp.InitiateFlow(laddr, fmt.Sprintf("%s:%d", peer.RemoteHost, peer.RemotePort))
if err != nil {
return err
}
if !peer.DisableConsumer {
p.AddConsumer(ctx, f, g())
}
if !peer.DisableProducer {
p.AddProducer(ctx, f, v())
}
return nil
}
err := tcp.NewListener(ctx, p, laddr(), v, g, !peer.DisableConsumer, !peer.DisableProducer)
if err != nil {
return err
}
return nil
}
func buildUdp(ctx context.Context, p *proxy.Proxy, peer Peer, g func() proxy.MacGenerator, v func() proxy.MacVerifier) error {
var laddr func() string
if peer.LocalPort == 0 {
laddr = func() string { return fmt.Sprintf("%s:", peer.GetLocalHost()) }
} else {
laddr = func() string { return fmt.Sprintf("%s:%d", peer.GetLocalHost(), peer.LocalPort) }
}
var c func() udp.Congestion
switch peer.Congestion {
case "None":
c = func() udp.Congestion { return congestion.NewNone() }
default:
fallthrough
case "NewReno":
c = func() udp.Congestion { return congestion.NewNewReno() }
}
if peer.RemoteHost != "" {
f, err := udp.InitiateFlow(
laddr,
fmt.Sprintf("%s:%d", peer.RemoteHost, peer.RemotePort),
v(),
g(),
c(),
time.Duration(peer.KeepAlive)*time.Second,
)
if err != nil {
return err
}
if !peer.DisableConsumer {
p.AddConsumer(ctx, f, g())
}
if !peer.DisableProducer {
p.AddProducer(ctx, f, v())
}
return nil
}
err := udp.NewListener(ctx, p, laddr(), v, g, c, !peer.DisableConsumer, !peer.DisableProducer)
if err != nil {
return err
}

76
config/config.go
View File

@ -1,32 +1,96 @@
package config
import "github.com/go-playground/validator/v10"
import (
"github.com/go-playground/validator/v10"
"log"
"net"
"strings"
)
var v = validator.New()
func init() {
if err := v.RegisterValidation("iface", func(fl validator.FieldLevel) bool {
name, ok := fl.Field().Interface().(string)
if ok && name != "" {
ifaces, err := net.Interfaces()
if err != nil {
log.Printf("error getting interfaces: %v", err)
return false
}
for _, i := range ifaces {
if i.Name == name {
return true
}
}
}
return false
}); err != nil {
panic(err)
}
}
type Configuration struct {
Host Host
Peers []Peer `validate:"dive"`
}
type Host struct {
PrivateKey string `validate:"required"`
InterfaceName string
Crypto string `validate:"required,oneof=None Blake2s"`
SharedKey string `validate:"required_if=Crypto Blake2s"`
MTU uint `validate:"required,min=576"`
}
type Peer struct {
PublicKey string `validate:"required"`
Method string `validate:"oneof=TCP"`
Method string `validate:"oneof=TCP UDP"`
LocalHost string `validate:"omitempty,ip"`
LocalHost string `validate:"omitempty,ip|iface"`
LocalPort uint `validate:"max=65535"`
RemoteHost string `validate:"required_with=RemotePort,omitempty,fqdn|ip"`
RemotePort uint `validate:"required_with=RemoteHost,omitempty,max=65535"`
Congestion string `validate:"required_unless=Method TCP,omitempty,oneof=NewReno None"`
KeepAlive uint
Timeout uint
RetryWait uint
DisableConsumer bool `validate:"omitempty,nefield=DisableProducer"`
DisableProducer bool `validate:"omitempty,nefield=DisableConsumer"`
}
func (p Peer) GetLocalHost() string {
if p.LocalHost == "" {
return ""
}
if err := v.Var(p.LocalHost, "ip"); err == nil {
return p.LocalHost
}
iface, err := net.InterfaceByName(p.LocalHost)
if err != nil {
panic(err)
}
if iface != nil {
addrs, err := iface.Addrs()
if err != nil {
panic(err)
}
if len(addrs) > 0 {
addr := addrs[0].String()
addr = strings.Split(addr, "/")[0]
log.Printf("resolved interface `%s` to `%v`", p.LocalHost, addr)
return addr
}
}
return "invalid"
}
func (c Configuration) Validate() error {

15
crypto/none.go Normal file
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@ -0,0 +1,15 @@
package crypto
type None struct{}
func (None) CodeLength() int {
return 0
}
func (None) Generate([]byte) []byte {
return nil
}
func (None) Verify([]byte, []byte) error {
return nil
}

40
crypto/sharedkey/blake2s.go Normal file
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@ -0,0 +1,40 @@
package sharedkey
import (
"bytes"
"golang.org/x/crypto/blake2s"
"mpbl3p/shared"
)
type Blake2s struct {
key []byte
}
func NewBlake2s(key []byte) (*Blake2s, error) {
_, err := blake2s.New128(key)
if err != nil {
return nil, err
}
return &Blake2s{key: key}, nil
}
func (b Blake2s) CodeLength() int {
return blake2s.Size128
}
func (b Blake2s) Generate(d []byte) []byte {
h, _ := blake2s.New128(b.key)
h.Write(d)
return h.Sum([]byte{})
}
func (b Blake2s) Verify(d []byte, s []byte) error {
h, _ := blake2s.New128(b.key)
h.Write(d)
sum := h.Sum([]byte{})
if !bytes.Equal(sum, s) {
return shared.ErrBadChecksum
}
return nil
}

45
crypto/sharedkey/blake2s_test.go Normal file
View File

@ -0,0 +1,45 @@
package sharedkey
import (
"github.com/stretchr/testify/assert"
"math/rand"
"mpbl3p/shared"
"testing"
)
func TestBlake2s_GenerateVerify(t *testing.T) {
t.Run("GeneratedVerifies", func(t *testing.T) {
// ASSIGN
key := make([]byte, 16)
rand.Read(key)
buf := make([]byte, 500)
rand.Read(buf)
// ACT
b := Blake2s{key}
code := b.Generate(buf)
// ASSERT
err := b.Verify(buf, code)
assert.Nil(t, err)
})
t.Run("FlippedBitFailsVerify", func(t *testing.T) {
// ASSIGN
key := make([]byte, 16)
rand.Read(key)
buf := make([]byte, 500)
rand.Read(buf)
// ACT
b := Blake2s{key}
code := b.Generate(buf)
offset := rand.Intn(len(buf) * 8)
buf[offset/8] ^= 1 << (offset % 8)
// ASSERT
err := b.Verify(buf, code)
assert.Equal(t, shared.ErrBadChecksum, err)
})
}

41
flags/flags.go Normal file
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@ -0,0 +1,41 @@
package flags
import (
"errors"
"fmt"
goflags "github.com/jessevdk/go-flags"
"os"
)
var PrintedHelpErr = goflags.ErrHelp
var NotEnoughArgs = errors.New("not enough arguments")
type Options struct {
Foreground bool `short:"f" long:"foreground" description:"Run in the foreground"`
ConfigFile string `short:"c" long:"config" description:"Configuration file location" value-name:"FILE"`
PidFile string `short:"p" long:"pid" description:"PID file location"`
Positional struct {
InterfaceName string `required:"yes" positional-arg-name:"INTERFACE-NAME" description:"Interface name"`
} `positional-args:"yes"`
}
func ParseFlags() (*Options, error) {
o := new(Options)
parser := goflags.NewParser(o, goflags.Default)
_, err := parser.Parse()
if err != nil {
parser.WriteHelp(os.Stdout)
return nil, err
}
if o.ConfigFile == "" {
o.ConfigFile = fmt.Sprintf(DefaultConfigFile, o.Positional.InterfaceName)
}
if o.PidFile == "" {
o.PidFile = fmt.Sprintf(DefaultPidFile, o.Positional.InterfaceName)
}
return o, nil
}

4
flags/locs_freebsd.go Normal file
View File

@ -0,0 +1,4 @@
package flags
const DefaultConfigFile = "/usr/local/etc/netcombiner/%s"
const DefaultPidFile = "/var/run/netcombiner/%s.pid"

4
flags/locs_linux.go Normal file
View File

@ -0,0 +1,4 @@
package flags
const DefaultConfigFile = "/etc/netcombiner/%s"
const DefaultPidFile = "/var/run/netcombiner/%s.pid"

8
go.mod
View File

@ -3,10 +3,12 @@ module mpbl3p
go 1.15
require (
github.com/go-playground/assert/v2 v2.0.1
github.com/go-playground/validator/v10 v10.4.1
github.com/pkg/taptun v0.0.0-20160424131934-bbbd335672ab
github.com/go-playground/validator/v10 v10.6.0
github.com/jessevdk/go-flags v1.5.0
github.com/smartystreets/goconvey v1.6.4 // indirect
github.com/stretchr/testify v1.4.0
golang.org/x/crypto v0.0.0-20210322153248-0c34fe9e7dc2
golang.org/x/net v0.0.0-20210326060303-6b1517762897 // indirect
golang.zx2c4.com/wireguard v0.0.0-20201118132417-da19db415a58
gopkg.in/ini.v1 v1.62.0
)

28
go.sum
View File

@ -8,14 +8,16 @@ github.com/go-playground/universal-translator v0.17.0 h1:icxd5fm+REJzpZx7ZfpaD87
github.com/go-playground/universal-translator v0.17.0/go.mod h1:UkSxE5sNxxRwHyU+Scu5vgOQjsIJAF8j9muTVoKLVtA=
github.com/go-playground/validator/v10 v10.4.1 h1:pH2c5ADXtd66mxoE0Zm9SUhxE20r7aM3F26W0hOn+GE=
github.com/go-playground/validator/v10 v10.4.1/go.mod h1:nlOn6nFhuKACm19sB/8EGNn9GlaMV7XkbRSipzJ0Ii4=
github.com/go-playground/validator/v10 v10.6.0 h1:UGIt4xR++fD9QrBOoo/ascJfGe3AGHEB9s6COnss4Rk=
github.com/go-playground/validator/v10 v10.6.0/go.mod h1:xm76BBt941f7yWdGnI2DVPFFg1UK3YY04qifoXU3lOk=
github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1 h1:EGx4pi6eqNxGaHF6qqu48+N2wcFQ5qg5FXgOdqsJ5d8=
github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1/go.mod h1:wJfORRmW1u3UXTncJ5qlYoELFm8eSnnEO6hX4iZ3EWY=
github.com/jessevdk/go-flags v1.5.0 h1:1jKYvbxEjfUl0fmqTCOfonvskHHXMjBySTLW4y9LFvc=
github.com/jessevdk/go-flags v1.5.0/go.mod h1:Fw0T6WPc1dYxT4mKEZRfG5kJhaTDP9pj1c2EWnYs/m4=
github.com/jtolds/gls v4.20.0+incompatible h1:xdiiI2gbIgH/gLH7ADydsJ1uDOEzR8yvV7C0MuV77Wo=
github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
github.com/leodido/go-urn v1.2.0 h1:hpXL4XnriNwQ/ABnpepYM/1vCLWNDfUNts8dX3xTG6Y=
github.com/leodido/go-urn v1.2.0/go.mod h1:+8+nEpDfqqsY+g338gtMEUOtuK+4dEMhiQEgxpxOKII=
github.com/pkg/taptun v0.0.0-20160424131934-bbbd335672ab h1:dAXDRtXYxj4sTR5WeRuTFJGH18QMT6AUpUgRwedI6es=
github.com/pkg/taptun v0.0.0-20160424131934-bbbd335672ab/go.mod h1:N5a/Ll2ZNk5wjiLNW9LIiNtO9RNYcaYmcXSYKMYrlDg=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d h1:zE9ykElWQ6/NYmHa3jpm/yHnI4xSofP+UP6SpjHcSeM=
@ -26,17 +28,35 @@ github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+
github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9 h1:psW17arqaxU48Z5kZ0CQnkZWQJsqcURM6tKiBApRjXI=
golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
golang.org/x/crypto v0.0.0-20201117144127-c1f2f97bffc9/go.mod h1:jdWPYTVW3xRLrWPugEBEK3UY2ZEsg3UU495nc5E+M+I=
golang.org/x/crypto v0.0.0-20210322153248-0c34fe9e7dc2 h1:It14KIkyBFYkHkwZ7k45minvA9aorojkyjGk9KJ5B/w=
golang.org/x/crypto v0.0.0-20210322153248-0c34fe9e7dc2/go.mod h1:T9bdIzuCu7OtxOm1hfPfRQxPLYneinmdGuTeoZ9dtd4=
golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
golang.org/x/net v0.0.0-20201110031124-69a78807bb2b/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
golang.org/x/net v0.0.0-20210326060303-6b1517762897 h1:KrsHThm5nFk34YtATK1LsThyGhGbGe1olrte/HInHvs=
golang.org/x/net v0.0.0-20210326060303-6b1517762897/go.mod h1:uSPa2vr4CLtc/ILN5odXGNXS6mhrKVzTaCXzk9m6W3k=
golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
golang.org/x/sys v0.0.0-20190412213103-97732733099d h1:+R4KGOnez64A81RvjARKc4UT5/tI9ujCIVX+P5KiHuI=
golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20201117222635-ba5294a509c7/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20210320140829-1e4c9ba3b0c4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.0.0-20210324051608-47abb6519492 h1:Paq34FxTluEPvVyayQqMPgHm+vTOrIifmcYxFBx9TLg=
golang.org/x/sys v0.0.0-20210324051608-47abb6519492/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
golang.org/x/text v0.3.3 h1:cokOdA+Jmi5PJGXLlLllQSgYigAEfHXJAERHVMaCc2k=
golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
golang.org/x/tools v0.0.0-20190328211700-ab21143f2384/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
golang.zx2c4.com/wireguard v0.0.0-20201118132417-da19db415a58 h1:HiPOx0boQr3qv0HkZ4fGLtTXJ5tmkbv0d8UmkNcxdv0=
golang.zx2c4.com/wireguard v0.0.0-20201118132417-da19db415a58/go.mod h1:Dz+cq5bnrai9EpgYj4GDof/+qaGzbRWbeaAOs1bUYa0=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/ini.v1 v1.62.0 h1:duBzk771uxoUuOlyRLkHsygud9+5lrlGjdFBb4mSKDU=

127
main.go
View File

@ -1,36 +1,155 @@
package main
import (
"context"
"errors"
"fmt"
"log"
"mpbl3p/config"
"mpbl3p/flags"
"mpbl3p/tun"
"os"
"os/signal"
"strconv"
"syscall"
)
const (
ENV_NC_TUN_FD = "NC_TUN_FD"
ENV_NC_CONFIG_PATH = "NC_CONFIG_PATH"
)
func main() {
log.SetFlags(log.Ldate | log.Ltime | log.Llongfile)
if _, exists := os.LookupEnv(ENV_NC_TUN_FD); !exists {
// we are the parent process
// 1) process arguments
// 2) validate config
// 2) create a tun adapter
// 3) spawn a child
// 4) exit
o, err := flags.ParseFlags()
if err != nil {
if errors.Is(err, flags.PrintedHelpErr) {
return
}
panic(err)
}
log.Println("loading config...")
c, err := config.LoadConfig(o.ConfigFile)
if err != nil {
log.Fatalf("error validating config: %s", err.Error())
return
}
log.Println("creating tun adapter...")
t, err := tun.NewTun(o.Positional.InterfaceName, int(c.Host.MTU))
if err != nil {
panic(err)
}
if o.Foreground {
if err := os.Setenv(ENV_NC_TUN_FD, fmt.Sprintf("%d", t.File().Fd())); err != nil {
panic(err)
}
if err := os.Setenv(ENV_NC_CONFIG_PATH, o.ConfigFile); err != nil {
panic(err)
}
log.Println("switching to foreground")
goto FOREGROUND
}
files := make([]*os.File, 4)
files[0], _ = os.Open(os.DevNull) // stdin
files[1], _ = os.Open(os.DevNull) // stderr
files[2], _ = os.Open(os.DevNull) // stdout
files[3] = t.File()
env := os.Environ()
env = append(env, fmt.Sprintf("%s=3", ENV_NC_TUN_FD))
env = append(env, fmt.Sprintf("%s=%s", ENV_NC_CONFIG_PATH, o.ConfigFile))
attr := os.ProcAttr{
Env: env,
Files: files,
}
path, err := os.Executable()
if err != nil {
panic(err)
}
process, err := os.StartProcess(
path,
os.Args,
&attr,
)
if err != nil {
panic(err)
}
pidFile, err := os.Create(o.PidFile)
if err != nil {
panic(err)
}
if _, err := fmt.Fprintf(pidFile, "%d", process.Pid); err != nil {
panic(err)
}
_ = process.Release()
return
}
// we are the child process
// 1) recreate tun adapter from file descriptor
// 2) launch proxy
FOREGROUND:
log.Println("loading config...")
c, err := config.LoadConfig("config.ini")
c, err := config.LoadConfig(os.Getenv(ENV_NC_CONFIG_PATH))
if err != nil {
panic(err)
}
log.Println("connecting tun adapter...")
tunFd, err := strconv.ParseUint(os.Getenv(ENV_NC_TUN_FD), 10, 64)
if err != nil {
panic(err)
}
t, err := tun.NewFromFile(uintptr(tunFd), int(c.Host.MTU))
if err != nil {
panic(err)
}
defer func() {
if err := t.Close(); err != nil {
panic(err)
}
}()
log.Println("building config...")
p, err := c.Build()
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
p, err := c.Build(ctx, t, t)
if err != nil {
panic(err)
}
log.Println("starting...")
log.Println("starting proxy...")
p.Start()
log.Println("running")
log.Println("proxy started")
signals := make(chan os.Signal)
signal.Notify(signals, syscall.SIGTERM, syscall.SIGINT)
<-signals
log.Println("exiting...")
}

67
mocks/conn.go
View File

@ -1,67 +0,0 @@
package mocks
import "time"
type MockPerfectBiConn struct {
directionA chan byte
directionB chan byte
}
func NewMockPerfectBiConn(bufSize int) MockPerfectBiConn {
return MockPerfectBiConn{
directionA: make(chan byte, bufSize),
directionB: make(chan byte, bufSize),
}
}
func (bc MockPerfectBiConn) SideA() MockPerfectConn {
return MockPerfectConn{inbound: bc.directionA, outbound: bc.directionB}
}
func (bc MockPerfectBiConn) SideB() MockPerfectConn {
return MockPerfectConn{inbound: bc.directionB, outbound: bc.directionA}
}
type MockPerfectConn struct {
inbound chan byte
outbound chan byte
}
func (c MockPerfectConn) SetWriteDeadline(time.Time) error {
return nil
}
func (c MockPerfectConn) Read(p []byte) (n int, err error) {
for i := range p {
if i == 0 {
p[i] = <-c.inbound
} else {
select {
case b := <-c.inbound:
p[i] = b
default:
return i, nil
}
}
}
return len(p), nil
}
func (c MockPerfectConn) Write(p []byte) (n int, err error) {
for _, b := range p {
c.outbound <- b
}
return len(p), nil
}
func (c MockPerfectConn) NonBlockingRead(p []byte) (n int, err error) {
for i := range p {
select {
case b := <-c.inbound:
p[i] = b
default:
return i, nil
}
}
return len(p), nil
}

4
mocks/mac.go
View File

@ -1,6 +1,8 @@
package mocks
import "mpbl3p/shared"
import (
"mpbl3p/shared"
)
type AlmostUselessMac struct{}

62
mocks/packetconn.go Normal file
View File

@ -0,0 +1,62 @@
package mocks
import "net"
type MockPerfectBiPacketConn struct {
directionA chan []byte
directionB chan []byte
}
func NewMockPerfectBiPacketConn(bufSize int) MockPerfectBiPacketConn {
return MockPerfectBiPacketConn{
directionA: make(chan []byte, bufSize),
directionB: make(chan []byte, bufSize),
}
}
func (bc MockPerfectBiPacketConn) SideA() MockPerfectPacketConn {
return MockPerfectPacketConn{inbound: bc.directionA, outbound: bc.directionB}
}
func (bc MockPerfectBiPacketConn) SideB() MockPerfectPacketConn {
return MockPerfectPacketConn{inbound: bc.directionB, outbound: bc.directionA}
}
type MockPerfectPacketConn struct {
inbound chan []byte
outbound chan []byte
}
func (c MockPerfectPacketConn) Write(b []byte) (int, error) {
c.outbound <- b
return len(b), nil
}
func (c MockPerfectPacketConn) WriteToUDP(b []byte, addr *net.UDPAddr) (int, error) {
c.outbound <- b
return len(b), nil
}
func (c MockPerfectPacketConn) LocalAddr() net.Addr {
return &net.UDPAddr{
IP: net.IPv4(127, 0, 0, 1),
Port: 1234,
}
}
func (c MockPerfectPacketConn) ReadFromUDP(b []byte) (int, *net.UDPAddr, error) {
p := <-c.inbound
return copy(b, p), &net.UDPAddr{
IP: net.IPv4(127, 0, 0, 1),
Port: 1234,
}, nil
}
func (c MockPerfectPacketConn) NonBlockingRead(p []byte) (n int, err error) {
select {
case b := <-c.inbound:
return copy(p, b), nil
default:
return 0, nil
}
}

95
mocks/streamconn.go Normal file
View File

@ -0,0 +1,95 @@
package mocks
import (
"net"
"time"
)
type MockPerfectBiStreamConn struct {
directionA chan byte
directionB chan byte
}
func NewMockPerfectBiStreamConn(bufSize int) MockPerfectBiStreamConn {
return MockPerfectBiStreamConn{
directionA: make(chan byte, bufSize),
directionB: make(chan byte, bufSize),
}
}
func (bc MockPerfectBiStreamConn) SideA() MockPerfectStreamConn {
return MockPerfectStreamConn{inbound: bc.directionA, outbound: bc.directionB}
}
func (bc MockPerfectBiStreamConn) SideB() MockPerfectStreamConn {
return MockPerfectStreamConn{inbound: bc.directionB, outbound: bc.directionA}
}
type MockPerfectStreamConn struct {
inbound chan byte
outbound chan byte
}
type Conn interface {
Read(b []byte) (n int, err error)
Write(b []byte) (n int, err error)
SetWriteDeadline(time.Time) error
// For printing
LocalAddr() net.Addr
RemoteAddr() net.Addr
}
func (c MockPerfectStreamConn) Read(p []byte) (n int, err error) {
for i := range p {
if i == 0 {
p[i] = <-c.inbound
} else {
select {
case b := <-c.inbound:
p[i] = b
default:
return i, nil
}
}
}
return len(p), nil
}
func (c MockPerfectStreamConn) Write(p []byte) (n int, err error) {
for _, b := range p {
c.outbound <- b
}
return len(p), nil
}
func (c MockPerfectStreamConn) SetWriteDeadline(time.Time) error {
return nil
}
// Only used for printing flow information
func (c MockPerfectStreamConn) LocalAddr() net.Addr {
return &net.TCPAddr{
IP: net.IPv4(127, 0, 0, 1),
Port: 499,
}
}
func (c MockPerfectStreamConn) RemoteAddr() net.Addr {
return &net.TCPAddr{
IP: net.IPv4(127, 0, 0, 1),
Port: 500,
}
}
func (c MockPerfectStreamConn) NonBlockingRead(p []byte) (n int, err error) {
for i := range p {
select {
case b := <-c.inbound:
p[i] = b
default:
return i, nil
}
}
return len(p), nil
}

78
proxy/packet.go
View File

@ -5,56 +5,42 @@ import (
"time"
)
type Packet struct {
Data []byte
timestamp time.Time
type Packet interface {
Marshal() []byte
Contents() []byte
}
// create a packet from the raw data of an IP packet
func NewPacket(data []byte) Packet {
return Packet{
Data: data,
timestamp: time.Now(),
}
}
// rebuild a packet from the wrapped format
func UnmarshalPacket(raw []byte, verifier MacVerifier) (Packet, error) {
// the MAC is the last N bytes
data := raw[:len(raw)-verifier.CodeLength()]
sum := raw[len(raw)-verifier.CodeLength():]
if err := verifier.Verify(data, sum); err != nil {
return Packet{}, err
}
p := Packet{
Data: data[:len(data)-8],
}
unixTime := int64(binary.LittleEndian.Uint64(data[len(data)-8:]))
p.timestamp = time.Unix(unixTime, 0)
return p, nil
}
type SimplePacket []byte
// get the raw data of the IP packet
func (p Packet) Raw() []byte {
return p.Data
func (p SimplePacket) Marshal() []byte {
return p
}
// produce the wrapped format of a packet
func (p Packet) Marshal(generator MacGenerator) []byte {
// length of data + length of timestamp (8 byte) + length of checksum
slice := make([]byte, len(p.Data)+8+generator.CodeLength())
copy(slice, p.Data)
unixTime := uint64(p.timestamp.Unix())
binary.LittleEndian.PutUint64(slice[len(p.Data):], unixTime)
mac := generator.Generate(slice)
copy(slice[len(p.Data)+8:], mac)
return slice
func (p SimplePacket) Contents() []byte {
return p
}
func AppendMac(b []byte, g MacGenerator) []byte {
footer := make([]byte, 8)
unixTime := uint64(time.Now().Unix())
binary.LittleEndian.PutUint64(footer, unixTime)
b = append(b, footer...)
mac := g.Generate(b)
return append(b, mac...)
}
func StripMac(b []byte, v MacVerifier) ([]byte, error) {
data := b[:len(b)-v.CodeLength()]
sum := b[len(b)-v.CodeLength():]
if err := v.Verify(data, sum); err != nil {
return nil, err
}
// TODO: Verify timestamp
return data[:len(data)-8], nil
}

46
proxy/packet_test.go
View File

@ -4,31 +4,59 @@ import (
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
"mpbl3p/mocks"
"mpbl3p/shared"
"testing"
)
func TestPacket_Marshal(t *testing.T) {
func TestAppendMac(t *testing.T) {
testContent := []byte("A test string is the content of this packet.")
testPacket := NewPacket(testContent)
testMac := mocks.AlmostUselessMac{}
testPacket := SimplePacket(testContent)
testMarshalled := testPacket.Marshal()
appended := AppendMac(testMarshalled, testMac)
t.Run("Length", func(t *testing.T) {
marshalled := testPacket.Marshal(testMac)
assert.Len(t, appended, len(testMarshalled)+8+4)
})
assert.Len(t, marshalled, len(testContent)+8+4)
t.Run("Mac", func(t *testing.T) {
assert.Equal(t, []byte{'a', 'b', 'c', 'd'}, appended[len(testMarshalled)+8:])
})
t.Run("Original", func(t *testing.T) {
assert.Equal(t, testMarshalled, appended[:len(testMarshalled)])
})
}
func TestUnmarshalPacket(t *testing.T) {
func TestStripMac(t *testing.T) {
testContent := []byte("A test string is the content of this packet.")
testPacket := NewPacket(testContent)
testMac := mocks.AlmostUselessMac{}
testMarshalled := testPacket.Marshal(testMac)
testPacket := SimplePacket(testContent)
testMarshalled := testPacket.Marshal()
appended := AppendMac(testMarshalled, testMac)
t.Run("Length", func(t *testing.T) {
p, err := UnmarshalPacket(testMarshalled, testMac)
cut, err := StripMac(appended, testMac)
require.Nil(t, err)
assert.Len(t, p.Raw(), len(testContent))
assert.Len(t, cut, len(testMarshalled))
})
t.Run("IncorrectMac", func(t *testing.T) {
badMac := make([]byte, len(testMarshalled)+4)
copy(badMac, testMarshalled)
copy(badMac[:len(testMarshalled)], "dcba")
_, err := StripMac(badMac, testMac)
assert.Error(t, err, shared.ErrBadChecksum)
})
t.Run("Original", func(t *testing.T) {
cut, err := StripMac(appended, testMac)
require.Nil(t, err)
assert.Equal(t, testMarshalled, cut)
})
}

71
proxy/proxy.go
View File

@ -1,22 +1,24 @@
package proxy
import (
"context"
"errors"
"log"
"time"
)
type Producer interface {
IsAlive() bool
Produce(MacVerifier) (Packet, error)
Produce(context.Context, MacVerifier) (Packet, error)
}
type Consumer interface {
IsAlive() bool
Consume(Packet, MacGenerator) error
Consume(context.Context, Packet, MacGenerator) error
}
type Reconnectable interface {
Reconnect() error
Reconnect(context.Context) error
}
type Source interface {
@ -31,8 +33,6 @@ type Proxy struct {
Source Source
Sink Sink
Generator MacGenerator
proxyChan chan Packet
sinkChan chan Packet
}
@ -67,7 +67,7 @@ func (p Proxy) Start() {
}()
}
func (p Proxy) AddConsumer(c Consumer) {
func (p Proxy) AddConsumer(ctx context.Context, c Consumer, g MacGenerator) {
go func() {
_, reconnectable := c.(Reconnectable)
@ -75,28 +75,42 @@ func (p Proxy) AddConsumer(c Consumer) {
if reconnectable {
var err error
for once := true; err != nil || once; once = false {
log.Printf("attempting to connect `%v`\n", c)
err = c.(Reconnectable).Reconnect()
log.Printf("attempting to connect consumer `%v`\n", c)
err = c.(Reconnectable).Reconnect(ctx)
if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
log.Printf("closed consumer `%v` (context)\n", c)
return
}
if !once {
time.Sleep(time.Second)
}
}
log.Printf("connected `%v`\n", c)
log.Printf("connected consumer `%v`\n", c)
}
for c.IsAlive() {
if err := c.Consume(<-p.proxyChan, p.Generator); err != nil {
log.Println(err)
break
select {
case <-ctx.Done():
log.Printf("closed consumer `%v` (context)\n", c)
return
case packet := <-p.proxyChan:
if err := c.Consume(ctx, packet, g); err != nil {
if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
log.Printf("closed consumer `%v` (context)\n", c)
return
}
log.Println(err)
break
}
}
}
}
log.Printf("closed connection `%v`\n", c)
log.Printf("closed consumer `%v`\n", c)
}()
}
func (p Proxy) AddProducer(pr Producer, v MacVerifier) {
func (p Proxy) AddProducer(ctx context.Context, pr Producer, v MacVerifier) {
go func() {
_, reconnectable := pr.(Reconnectable)
@ -104,25 +118,42 @@ func (p Proxy) AddProducer(pr Producer, v MacVerifier) {
if reconnectable {
var err error
for once := true; err != nil || once; once = false {
log.Printf("attempting to connect `%v`\n", pr)
err = pr.(Reconnectable).Reconnect()
log.Printf("attempting to connect producer `%v`\n", pr)
err = pr.(Reconnectable).Reconnect(ctx)
if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
log.Printf("closed producer `%v` (context)\n", pr)
return
}
if !once {
time.Sleep(time.Second)
}
if ctx.Err() != nil {
return
}
}
log.Printf("connected `%v`\n", pr)
log.Printf("connected producer `%v`\n", pr)
}
for pr.IsAlive() {
if packet, err := pr.Produce(v); err != nil {
if packet, err := pr.Produce(ctx, v); err != nil {
if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
log.Printf("closed producer `%v` (context)\n", pr)
return
}
log.Println(err)
break
} else {
p.sinkChan <- packet
select {
case <-ctx.Done():
log.Printf("closed producer `%v` (context)\n", pr)
return
case p.sinkChan <- packet:
}
}
}
}
log.Printf("closed connection `%v`\n", pr)
log.Printf("closed producer `%v`\n", pr)
}()
}

1
shared/errors.go
View File

@ -4,3 +4,4 @@ import "errors"
var ErrBadChecksum = errors.New("the packet had a bad checksum")
var ErrDeadConnection = errors.New("the connection is dead")
var ErrNotEnoughBytes = errors.New("not enough bytes")

198
tcp/flow.go
View File

@ -1,8 +1,10 @@
package tcp
import (
"bufio"
"context"
"encoding/binary"
"errors"
"fmt"
"io"
"mpbl3p/proxy"
"mpbl3p/shared"
@ -11,16 +13,18 @@ import (
"time"
)
var ErrNotEnoughBytes = errors.New("not enough bytes")
type Conn interface {
Read(b []byte) (n int, err error)
Write(b []byte) (n int, err error)
SetWriteDeadline(time.Time) error
// For printing
LocalAddr() net.Addr
RemoteAddr() net.Addr
}
type InitiatedFlow struct {
Local string
Local func() string
Remote string
mu sync.RWMutex
@ -28,21 +32,64 @@ type InitiatedFlow struct {
Flow
}
func (f *InitiatedFlow) String() string {
return fmt.Sprintf("TcpOutbound{%v -> %v}", f.Local(), f.Remote)
}
type Flow struct {
conn Conn
isAlive bool
toConsume, produced chan []byte
consumeErrors, produceErrors chan error
}
func InitiateFlow(local, remote string) (*InitiatedFlow, error) {
func NewFlow() Flow {
return Flow{
toConsume: make(chan []byte),
produced: make(chan []byte),
consumeErrors: make(chan error),
produceErrors: make(chan error),
}
}
func NewFlowConn(ctx context.Context, conn Conn) Flow {
f := Flow{
conn: conn,
isAlive: true,
toConsume: make(chan []byte),
produced: make(chan []byte),
consumeErrors: make(chan error),
produceErrors: make(chan error),
}
go f.produceMarshalled(ctx)
go f.consumeMarshalled(ctx)
return f
}
func (f Flow) String() string {
return fmt.Sprintf("TcpInbound{%v -> %v}", f.conn.RemoteAddr(), f.conn.LocalAddr())
}
func (f *Flow) IsAlive() bool {
return f.isAlive
}
func InitiateFlow(local func() string, remote string) (*InitiatedFlow, error) {
f := InitiatedFlow{
Local: local,
Remote: remote,
Flow: NewFlow(),
}
return &f, nil
}
func (f *InitiatedFlow) Reconnect() error {
func (f *InitiatedFlow) Reconnect(ctx context.Context) error {
f.mu.Lock()
defer f.mu.Unlock()
@ -50,7 +97,7 @@ func (f *InitiatedFlow) Reconnect() error {
return nil
}
localAddr, err := net.ResolveTCPAddr("tcp", f.Local)
localAddr, err := net.ResolveTCPAddr("tcp", f.Local())
if err != nil {
return err
}
@ -65,93 +112,128 @@ func (f *InitiatedFlow) Reconnect() error {
return err
}
err = conn.SetWriteBuffer(0)
if err != nil {
if err := conn.SetWriteBuffer(0); err != nil {
return err
}
f.conn = conn
f.isAlive = true
go f.produceMarshalled(ctx)
go f.consumeMarshalled(ctx)
return nil
}
func (f *Flow) IsAlive() bool {
return f.isAlive
}
func (f *InitiatedFlow) Consume(p proxy.Packet, g proxy.MacGenerator) error {
func (f *InitiatedFlow) Consume(ctx context.Context, p proxy.Packet, g proxy.MacGenerator) error {
f.mu.RLock()
defer f.mu.RUnlock()
return f.Flow.Consume(p, g)
return f.Flow.Consume(ctx, p, g)
}
func (f *Flow) Consume(p proxy.Packet, g proxy.MacGenerator) (err error) {
func (f *InitiatedFlow) Produce(ctx context.Context, v proxy.MacVerifier) (proxy.Packet, error) {
f.mu.RLock()
defer f.mu.RUnlock()
return f.Flow.Produce(ctx, v)
}
func (f *Flow) Consume(ctx context.Context, p proxy.Packet, g proxy.MacGenerator) error {
if !f.isAlive {
return shared.ErrDeadConnection
}
data := p.Marshal(g)
err = f.consumeMarshalled(data)
if err != nil {
select {
case err := <-f.consumeErrors:
f.isAlive = false
return err
default:
}
return
}
func (f *Flow) consumeMarshalled(data []byte) error {
marshalled := p.Marshal()
data := proxy.AppendMac(marshalled, g)
prefixedData := make([]byte, len(data)+4)
binary.LittleEndian.PutUint32(prefixedData, uint32(len(data)))
copy(prefixedData[4:], data)
err := f.conn.SetWriteDeadline(time.Now().Add(5 * time.Second))
if err != nil {
return err
select {
case f.toConsume <- prefixedData:
case <-ctx.Done():
return ctx.Err()
}
_, err = f.conn.Write(prefixedData)
return err
return nil
}
func (f *InitiatedFlow) Produce(v proxy.MacVerifier) (proxy.Packet, error) {
f.mu.RLock()
defer f.mu.RUnlock()
return f.Flow.Produce(v)
}
func (f *Flow) Produce(v proxy.MacVerifier) (proxy.Packet, error) {
func (f *Flow) Produce(ctx context.Context, v proxy.MacVerifier) (proxy.Packet, error) {
if !f.isAlive {
return proxy.Packet{}, shared.ErrDeadConnection
return nil, shared.ErrDeadConnection
}
data, err := f.produceMarshalled()
if err != nil {
var data []byte
select {
case <-ctx.Done():
return nil, ctx.Err()
case data = <-f.produced:
case err := <-f.produceErrors:
f.isAlive = false
return proxy.Packet{}, err
return nil, err
}
return proxy.UnmarshalPacket(data, v)
b, err := proxy.StripMac(data, v)
if err != nil {
return nil, err
}
return proxy.SimplePacket(b), nil
}
func (f *Flow) produceMarshalled() ([]byte, error) {
lengthBytes := make([]byte, 4)
if n, err := io.LimitReader(f.conn, 4).Read(lengthBytes); err != nil {
return nil, err
} else if n != 4 {
return nil, ErrNotEnoughBytes
}
func (f *Flow) consumeMarshalled(ctx context.Context) {
for {
data := <-f.toConsume
length := binary.LittleEndian.Uint32(lengthBytes)
dataBytes := make([]byte, length)
var read uint32
for read < length {
if n, err := io.LimitReader(f.conn, int64(length-read)).Read(dataBytes[read:]); err != nil {
return nil, err
} else {
read += uint32(n)
err := f.conn.SetWriteDeadline(time.Now().Add(5 * time.Second))
if err != nil {
f.consumeErrors <- err
return
}
_, err = f.conn.Write(data)
if err != nil {
f.consumeErrors <- err
return
}
}
return dataBytes, nil
}
func (f *Flow) produceMarshalled(ctx context.Context) {
buf := bufio.NewReader(f.conn)
for {
lengthBytes := make([]byte, 4)
if n, err := io.LimitReader(buf, 4).Read(lengthBytes); err != nil {
f.produceErrors <- err
return
} else if n != 4 {
f.produceErrors <- shared.ErrNotEnoughBytes
return
}
length := binary.LittleEndian.Uint32(lengthBytes)
dataBytes := make([]byte, length)
var read uint32
for read < length {
if n, err := io.LimitReader(buf, int64(length-read)).Read(dataBytes[read:]); err != nil {
f.produceErrors <- err
return
} else {
read += uint32(n)
}
}
f.produced <- dataBytes
}
}

27
tcp/flow_test.go
View File

@ -1,8 +1,9 @@
package tcp
import (
"context"
"encoding/binary"
"github.com/go-playground/assert/v2"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
"mpbl3p/mocks"
"mpbl3p/proxy"
@ -11,15 +12,15 @@ import (
func TestFlow_Consume(t *testing.T) {
testContent := []byte("A test string is the content of this packet.")
testPacket := proxy.NewPacket(testContent)
testPacket := proxy.SimplePacket(testContent)
testMac := mocks.AlmostUselessMac{}
t.Run("Length", func(t *testing.T) {
testConn := mocks.NewMockPerfectBiConn(100)
testConn := mocks.NewMockPerfectBiStreamConn(100)
flowA := Flow{conn: testConn.SideA(), isAlive: true}
flowA := NewFlowConn(context.Background(), testConn.SideA())
err := flowA.Consume(testPacket, testMac)
err := flowA.Consume(context.Background(), testPacket, testMac)
require.Nil(t, err)
buf := make([]byte, 100)
@ -39,28 +40,28 @@ func TestFlow_Produce(t *testing.T) {
testMac := mocks.AlmostUselessMac{}
t.Run("Length", func(t *testing.T) {
testConn := mocks.NewMockPerfectBiConn(100)
testConn := mocks.NewMockPerfectBiStreamConn(100)
flowA := Flow{conn: testConn.SideA(), isAlive: true}
flowA := NewFlowConn(context.Background(), testConn.SideA())
_, err := testConn.SideB().Write(testMarshalled)
require.Nil(t, err)
p, err := flowA.Produce(testMac)
p, err := flowA.Produce(context.Background(), testMac)
require.Nil(t, err)
assert.Equal(t, len(testContent), len(p.Raw()))
assert.Equal(t, len(testContent), len(p.Contents()))
})
t.Run("Value", func(t *testing.T) {
testConn := mocks.NewMockPerfectBiConn(100)
testConn := mocks.NewMockPerfectBiStreamConn(100)
flowA := Flow{conn: testConn.SideA(), isAlive: true}
flowA := NewFlowConn(context.Background(), testConn.SideA())
_, err := testConn.SideB().Write(testMarshalled)
require.Nil(t, err)
p, err := flowA.Produce(testMac)
p, err := flowA.Produce(context.Background(), testMac)
require.Nil(t, err)
assert.Equal(t, testContent, string(p.Raw()))
assert.Equal(t, testContent, string(p.Contents()))
})
}

18
tcp/listener.go
View File

@ -1,12 +1,13 @@
package tcp
import (
"context"
"log"
"mpbl3p/proxy"
"net"
)
func NewListener(p *proxy.Proxy, local string, v proxy.MacVerifier) error {
func NewListener(ctx context.Context, p *proxy.Proxy, local string, v func() proxy.MacVerifier, g func() proxy.MacGenerator, enableConsumers bool, enableProducers bool) error {
laddr, err := net.ResolveTCPAddr("tcp", local)
if err != nil {
return err
@ -24,17 +25,20 @@ func NewListener(p *proxy.Proxy, local string, v proxy.MacVerifier) error {
panic(err)
}
err = conn.SetWriteBuffer(0)
if err != nil {
if err := conn.SetWriteBuffer(0); err != nil {
panic(err)
}
f := Flow{conn: conn, isAlive: true}
f := NewFlowConn(ctx, conn)
log.Printf("received new connection: %v\n", f)
log.Printf("received new tcp connection: %v\n", f)
p.AddConsumer(&f)
p.AddProducer(&f, v)
if enableConsumers {
p.AddConsumer(ctx, &f, g())
}
if enableProducers {
p.AddProducer(ctx, &f, v())
}
}
}()

72
tun/tun.go
View File

@ -1,85 +1,65 @@
package tun
import (
"github.com/pkg/taptun"
wgtun "golang.zx2c4.com/wireguard/tun"
"io"
"log"
"mpbl3p/proxy"
"net"
"os"
"strings"
"sync"
"time"
)
type SourceSink struct {
tun *taptun.Tun
bufferSize int
up bool
upMu sync.Mutex
tun wgtun.Device
}
func NewTun(namingScheme string, bufferSize int) (ss *SourceSink, err error) {
ss = &SourceSink{}
func NewTun(name string, mtu int) (t wgtun.Device, err error) {
return wgtun.CreateTUN(name, mtu)
}
ss.tun, err = taptun.NewTun(namingScheme)
func NewFromFile(fd uintptr, mtu int) (ss *SourceSink, err error) {
ss = new(SourceSink)
file := os.NewFile(fd, "")
ss.tun, err = wgtun.CreateTUNFromFile(file, mtu)
if err != nil {
return
}
ss.bufferSize = bufferSize
ss.upMu.Lock()
go func() {
defer ss.upMu.Unlock()
for {
iface, err := net.InterfaceByName(ss.tun.String())
if err != nil {
panic(err)
}
if strings.Contains(iface.Flags.String(), "up") {
log.Println("tun is up")
ss.up = true
return
}
time.Sleep(100 * time.Millisecond)
}
}()
return
}
func (t *SourceSink) Close() error {
return t.tun.Close()
}
func (t *SourceSink) Source() (proxy.Packet, error) {
if !t.up {
t.upMu.Lock()
t.upMu.Unlock()
mtu, err := t.tun.MTU()
if err != nil {
return nil, err
}
buf := make([]byte, t.bufferSize)
buf := make([]byte, mtu+4)
read, err := t.tun.Read(buf)
read, err := t.tun.Read(buf, 4)
if err != nil {
return proxy.Packet{}, err
return nil, err
}
if read == 0 {
return proxy.Packet{}, io.EOF
return nil, io.EOF
}
return proxy.NewPacket(buf[:read]), nil
return proxy.SimplePacket(buf[4 : read+4]), nil
}
var good, bad float64
func (t *SourceSink) Sink(packet proxy.Packet) error {
if !t.up {
t.upMu.Lock()
t.upMu.Unlock()
}
// make space for tun header
content := make([]byte, len(packet.Contents())+4)
copy(content[4:], packet.Contents())
_, err := t.tun.Write(packet.Raw())
_, err := t.tun.Write(content, 4)
if err != nil {
switch err.(type) {
case *os.PathError:

16
udp/congestion.go Normal file
View File

@ -0,0 +1,16 @@
package udp
import (
"context"
"time"
)
type Congestion interface {
Sequence(ctx context.Context) (uint32, error)
NextAck() uint32
NextNack() uint32
ReceivedPacket(seq, nack, ack uint32)
AwaitEarlyUpdate(ctx context.Context, keepalive time.Duration) (uint32, error)
}

284
udp/congestion/newreno.go Normal file
View File

@ -0,0 +1,284 @@
package congestion
import (
"context"
"fmt"
"math"
"sort"
"sync"
"sync/atomic"
"time"
)
const RttExponentialFactor = 0.1
const RttLossDelay = 1.5
type NewReno struct {
sequence chan uint32
inFlight []flightInfo
lastSent time.Time
inFlightMu sync.Mutex
awaitingAck sortableFlights
ack, nack uint32
lastAck, lastNack uint32
ackNackMu sync.Mutex
rttNanos float64
windowSize, windowCount uint32
slowStart bool
windowNotifier chan struct{}
}
type flightInfo struct {
time time.Time
sequence uint32
}
type sortableFlights []flightInfo
func (f sortableFlights) Len() int {
return len(f)
}
func (f sortableFlights) Swap(i, j int) {
f[i], f[j] = f[j], f[i]
}
func (f sortableFlights) Less(i, j int) bool {
return f[i].sequence < f[j].sequence
}
func (c *NewReno) String() string {
return fmt.Sprintf("{NewReno %t %d %d %d %d}", c.slowStart, c.windowSize, len(c.inFlight), c.lastAck, c.lastNack)
}
func NewNewReno() *NewReno {
c := NewReno{
sequence: make(chan uint32),
windowNotifier: make(chan struct{}),
windowSize: 1,
rttNanos: float64((10 * time.Millisecond).Nanoseconds()),
slowStart: true,
}
go func() {
var s uint32
for {
if s == 0 {
s++
continue
}
c.sequence <- s
s++
}
}()
return &c
}
func (c *NewReno) ReceivedPacket(seq, nack, ack uint32) {
// decide what acks and nacks to send
if seq != 0 {
c.receivedSequence(seq)
}
// decide how window size was affected
if nack != 0 {
c.receivedNack(nack)
}
if ack != 0 {
c.receivedAck(ack)
}
}
func (c *NewReno) Sequence(ctx context.Context) (uint32, error) {
for len(c.inFlight) >= int(c.windowSize) {
<-c.windowNotifier
}
c.inFlightMu.Lock()
defer c.inFlightMu.Unlock()
var s uint32
select {
case s = <-c.sequence:
case <-ctx.Done():
return 0, ctx.Err()
}
t := time.Now()
c.inFlight = append(c.inFlight, flightInfo{
time: t,
sequence: s,
})
c.lastSent = t
return s, nil
}
func (c *NewReno) NextAck() uint32 {
a := c.ack
atomic.StoreUint32(&c.lastAck, a)
return a
}
func (c *NewReno) NextNack() uint32 {
n := c.nack
atomic.StoreUint32(&c.lastNack, n)
return n
}
func (c *NewReno) AwaitEarlyUpdate(ctx context.Context, keepalive time.Duration) (uint32, error) {
for {
rtt := time.Duration(math.Round(c.rttNanos))
time.Sleep(rtt / 2)
c.checkNack()
// CASE 1: waiting ACKs or NACKs and no message sent in the last half-RTT
// this targets arrival in 0.5+0.5 ± 0.5 RTTs (1±0.5 RTTs)
if ((c.lastAck != c.ack) || (c.lastNack != c.nack)) && time.Now().After(c.lastSent.Add(rtt/2)) {
return 0, nil // no ack needed
}
// CASE 2: No message sent within the keepalive time
if keepalive != 0 && time.Now().After(c.lastSent.Add(keepalive)) {
return c.Sequence(ctx) // require an ack
}
}
}
func (c *NewReno) receivedSequence(seq uint32) {
c.ackNackMu.Lock()
defer c.ackNackMu.Unlock()
if seq < c.nack || seq < c.ack {
// packet received out of order has already been cumulatively NACKed
// or duplicate packet received and already ACKed
return
}
if seq != c.ack+1 && seq != c.nack+1 {
c.awaitingAck = append(c.awaitingAck, flightInfo{
time: time.Now(),
sequence: seq,
})
return // if this seq doesn't change the ack field, updateAck will still not do anything useful
}
sort.Sort(c.awaitingAck)
c.updateAck(seq)
}
func (c *NewReno) checkNack() {
c.ackNackMu.Lock()
defer c.ackNackMu.Unlock()
if len(c.awaitingAck) == 0 {
return
}
sort.Sort(c.awaitingAck)
lossThreshold := time.Duration(c.rttNanos * RttLossDelay)
if c.awaitingAck[0].time.Before(time.Now().Add(-lossThreshold)) {
// if the next packet sequence to ack was received more than an rttlossdelay ago
// mark the packet(s) blocking it as missing with a nack
// then update ack from the delayed packet
c.nack = c.awaitingAck[0].sequence - 1
c.updateAck(c.nack)
}
}
func (c *NewReno) updateAck(start uint32) {
a := start
var removed int
for _, e := range c.awaitingAck {
if e.sequence == a+1 {
a = e.sequence
removed++
} else {
break
}
}
c.ack = a
c.awaitingAck = c.awaitingAck[removed:]
}
func (c *NewReno) receivedNack(nack uint32) {
c.ackNackMu.Lock()
defer c.ackNackMu.Unlock()
c.inFlightMu.Lock()
defer c.inFlightMu.Unlock()
// as both ack and nack are cumulative, inflight will always be ordered by seq
var i int
for i < len(c.inFlight) && c.inFlight[i].sequence <= nack {
i++
}
if i == 0 {
return
}
c.slowStart = false
c.inFlight = c.inFlight[i:]
for {
s := c.windowSize
if s == 1 || atomic.CompareAndSwapUint32(&c.windowSize, s, s/2) {
break
}
}
select {
case c.windowNotifier <- struct{}{}:
default:
}
}
func (c *NewReno) receivedAck(ack uint32) {
c.ackNackMu.Lock()
defer c.ackNackMu.Unlock()
c.inFlightMu.Lock()
defer c.inFlightMu.Unlock()
// as both ack and nack are cumulative, inflight will always be ordered by seq
var i int
for i < len(c.inFlight) && c.inFlight[i].sequence <= ack {
rtt := float64(time.Now().Sub(c.inFlight[i].time).Nanoseconds())
c.rttNanos = c.rttNanos*(1-RttExponentialFactor) + rtt*RttExponentialFactor
i++
}
if i == 0 {
return
}
c.inFlight = c.inFlight[i:]
if c.slowStart {
atomic.AddUint32(&c.windowSize, uint32(i))
} else {
c.windowCount += uint32(i)
s := c.windowSize
if c.windowCount > s {
c.windowCount -= s
atomic.AddUint32(&c.windowSize, 1)
}
}
select {
case c.windowNotifier <- struct{}{}:
default:
}
}

369
udp/congestion/newreno_test.go Normal file
View File

@ -0,0 +1,369 @@
package congestion
import (
"context"
"github.com/stretchr/testify/assert"
"sort"
"testing"
"time"
)
type congestionPacket struct {
seq, nack, ack uint32
}
type newRenoTest struct {
sideA, sideB *NewReno
aOutbound, bOutbound chan congestionPacket
aInbound, bInbound chan congestionPacket
halfRtt time.Duration
}
func newNewRenoTest(rtt time.Duration) *newRenoTest {
return &newRenoTest{
sideA: NewNewReno(),
sideB: NewNewReno(),
aOutbound: make(chan congestionPacket),
bOutbound: make(chan congestionPacket),
aInbound: make(chan congestionPacket),
bInbound: make(chan congestionPacket),
halfRtt: rtt / 2,
}
}
func (n *newRenoTest) Start(ctx context.Context) {
type packetWithTime struct {
t time.Time
p congestionPacket
}
go func() {
aOutboundDelayed := make(chan packetWithTime, 128)
bOutboundDelayed := make(chan packetWithTime, 128)
delayer := func(tp chan packetWithTime, cp chan congestionPacket) {
for {
select {
case p := <-tp:
s := p.t.Add(n.halfRtt).Sub(time.Now())
time.Sleep(s)
cp <- p.p
case <-ctx.Done():
return
}
}
}
go delayer(aOutboundDelayed, n.bInbound)
go delayer(bOutboundDelayed, n.aInbound)
for {
select {
case <-ctx.Done():
return
case p := <-n.aOutbound:
aOutboundDelayed <- packetWithTime{t: time.Now(), p: p}
case p := <-n.bOutbound:
bOutboundDelayed <- packetWithTime{t: time.Now(), p: p}
}
}
}()
}
func (n *newRenoTest) RunSideA(ctx context.Context) {
go func() {
for {
select {
case <-ctx.Done():
return
case p := <-n.aInbound:
n.sideA.ReceivedPacket(p.seq, p.nack, p.ack)
}
}
}()
go func() {
for {
seq, err := n.sideA.AwaitEarlyUpdate(ctx, 500*time.Millisecond)
if err != nil {
return
}
if seq != 0 {
// skip keepalive
// required to ensure AwaitEarlyUpdate terminates
continue
}
p := congestionPacket{
seq: seq,
nack: n.sideA.NextNack(),
ack: n.sideA.NextAck(),
}
n.aOutbound <- p
}
}()
}
func (n *newRenoTest) RunSideB(ctx context.Context) {
go func() {
for {
select {
case <-ctx.Done():
return
case p := <-n.bInbound:
n.sideB.ReceivedPacket(p.seq, p.nack, p.ack)
}
}
}()
go func() {
for {
seq, err := n.sideB.AwaitEarlyUpdate(ctx, 500*time.Millisecond)
if err != nil {
return
}
if seq != 0 {
// skip keepalive
// required to ensure AwaitEarlyUpdate terminates
continue
}
p := congestionPacket{
seq: seq,
nack: n.sideB.NextNack(),
ack: n.sideB.NextAck(),
}
n.bOutbound <- p
}
}()
}
func TestNewReno_Congestion(t *testing.T) {
t.Run("OneWay", func(t *testing.T) {
t.Run("Lossless", func(t *testing.T) {
// ASSIGN
rtt := 80 * time.Millisecond
numPackets := 50
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
c := newNewRenoTest(rtt)
c.Start(ctx)
c.RunSideA(ctx)
c.RunSideB(ctx)
// ACT
for i := 0; i < numPackets; i++ {
// sleep to simulate preparing packet
time.Sleep(1 * time.Millisecond)
seq, _ := c.sideA.Sequence(ctx)
c.aOutbound <- congestionPacket{
seq: seq,
nack: c.sideA.NextNack(),
ack: c.sideA.NextAck(),
}
}
// allow the systems to catch up before asserting
time.Sleep(rtt + 30*time.Millisecond)
// ASSERT
assert.Equal(t, uint32(0), c.sideA.nack)
assert.Equal(t, uint32(0), c.sideA.ack)
assert.Equal(t, uint32(0), c.sideB.nack)
assert.Equal(t, uint32(numPackets), c.sideB.ack)
})
t.Run("SequenceLoss", func(t *testing.T) {
// ASSIGN
rtt := 80 * time.Millisecond
numPackets := 50
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
c := newNewRenoTest(rtt)
c.Start(ctx)
c.RunSideA(ctx)
c.RunSideB(ctx)
// ACT
for i := 0; i < numPackets; i++ {
// sleep to simulate preparing packet
time.Sleep(1 * time.Millisecond)
seq, _ := c.sideA.Sequence(ctx)
if seq == 20 {
// Simulate packet loss of sequence 20
continue
}
c.aOutbound <- congestionPacket{
seq: seq,
nack: c.sideA.NextNack(),
ack: c.sideA.NextAck(),
}
}
time.Sleep(rtt + 30*time.Millisecond)
// ASSERT
assert.Equal(t, uint32(0), c.sideA.nack)
assert.Equal(t, uint32(0), c.sideA.ack)
assert.Equal(t, uint32(20), c.sideB.nack)
assert.Equal(t, uint32(numPackets), c.sideB.ack)
})
})
t.Run("TwoWay", func(t *testing.T) {
t.Run("Lossless", func(t *testing.T) {
// ASSIGN
rtt := 80 * time.Millisecond
numPackets := 50
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
c := newNewRenoTest(rtt)
c.Start(ctx)
c.RunSideA(ctx)
c.RunSideB(ctx)
// ACT
done := make(chan struct{})
go func() {
for i := 0; i < numPackets; i++ {
time.Sleep(1 * time.Millisecond)
seq, _ := c.sideA.Sequence(ctx)
c.aOutbound <- congestionPacket{
seq: seq,
nack: c.sideA.NextNack(),
ack: c.sideA.NextAck(),
}
}
done <- struct{}{}
}()
go func() {
for i := 0; i < numPackets; i++ {
time.Sleep(1 * time.Millisecond)
seq, _ := c.sideB.Sequence(ctx)
c.bOutbound <- congestionPacket{
seq: seq,
nack: c.sideB.NextNack(),
ack: c.sideB.NextAck(),
}
}
done <- struct{}{}
}()
<-done
<-done
time.Sleep(rtt + 30*time.Millisecond)
// ASSERT
assert.Equal(t, uint32(0), c.sideA.nack)
assert.Equal(t, uint32(numPackets), c.sideA.ack)
assert.Equal(t, uint32(0), c.sideB.nack)
assert.Equal(t, uint32(numPackets), c.sideB.ack)
})
t.Run("SequenceLoss", func(t *testing.T) {
// ASSIGN
rtt := 80 * time.Millisecond
numPackets := 100
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
c := newNewRenoTest(rtt)
c.Start(ctx)
c.RunSideA(ctx)
c.RunSideB(ctx)
// ACT
done := make(chan struct{})
go func() {
for i := 0; i < numPackets; i++ {
time.Sleep(1 * time.Millisecond)
seq, _ := c.sideA.Sequence(ctx)
if seq == 9 {
// Simulate packet loss of sequence 9
continue
}
c.aOutbound <- congestionPacket{
seq: seq,
nack: c.sideA.NextNack(),
ack: c.sideA.NextAck(),
}
}
done <- struct{}{}
}()
go func() {
for i := 0; i < numPackets; i++ {
time.Sleep(1 * time.Millisecond)
seq, _ := c.sideB.Sequence(ctx)
if seq == 13 {
// Simulate packet loss of sequence 13
continue
}
c.bOutbound <- congestionPacket{
seq: seq,
nack: c.sideB.NextNack(),
ack: c.sideB.NextAck(),
}
}
done <- struct{}{}
}()
<-done
<-done
time.Sleep(rtt + 30*time.Millisecond)
// ASSERT
assert.Equal(t, uint32(13), c.sideA.nack)
assert.Equal(t, uint32(numPackets), c.sideA.ack)
assert.Equal(t, uint32(9), c.sideB.nack)
assert.Equal(t, uint32(numPackets), c.sideB.ack)
})
})
}
func TestSortableFlights_Less(t *testing.T) {
// ASSIGN
a := []flightInfo{{sequence: 0}, {sequence: 6}, {sequence: 3}, {sequence: 2}}
// ACT
sort.Sort(sortableFlights(a))
// ASSERT
assert.Equal(t, []flightInfo{{sequence: 0}, {sequence: 2}, {sequence: 3}, {sequence: 6}}, a)
}

26
udp/congestion/none.go Normal file
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package congestion
import (
"context"
"fmt"
"time"
)
type None struct{}
func NewNone() None {
return None{}
}
func (c None) String() string {
return fmt.Sprintf("{None}")
}
func (c None) ReceivedPacket(uint32, uint32, uint32) {}
func (c None) NextNack() uint32 { return 0 }
func (c None) NextAck() uint32 { return 0 }
func (c None) AwaitEarlyUpdate(ctx context.Context, _ time.Duration) (uint32, error) {
<-ctx.Done()
return 0, ctx.Err()
}
func (c None) Sequence(context.Context) (uint32, error) { return 0, nil }

306
udp/flow.go Normal file
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package udp
import (
"context"
"fmt"
"log"
"mpbl3p/proxy"
"mpbl3p/shared"
"net"
"sync"
"time"
)
type PacketWriter interface {
Write(b []byte) (int, error)
WriteToUDP(b []byte, addr *net.UDPAddr) (int, error)
LocalAddr() net.Addr
}
type PacketConn interface {
PacketWriter
ReadFromUDP(b []byte) (int, *net.UDPAddr, error)
}
type InitiatedFlow struct {
Local func() string
Remote string
g proxy.MacGenerator
keepalive time.Duration
mu sync.RWMutex
Flow
}
func (f *InitiatedFlow) String() string {
return fmt.Sprintf("UdpOutbound{%v -> %v}", f.Local(), f.Remote)
}
type Flow struct {
writer PacketWriter
raddr *net.UDPAddr
isAlive bool
startup bool
congestion Congestion
v proxy.MacVerifier
inboundDatagrams chan []byte
}
func (f Flow) String() string {
return fmt.Sprintf("UdpInbound{%v -> %v}", f.raddr, f.writer.LocalAddr())
}
func InitiateFlow(
local func() string,
remote string,
v proxy.MacVerifier,
g proxy.MacGenerator,
c Congestion,
keepalive time.Duration,
) (*InitiatedFlow, error) {
f := InitiatedFlow{
Local: local,
Remote: remote,
Flow: newFlow(c, v),
g: g,
keepalive: keepalive,
}
return &f, nil
}
func newFlow(c Congestion, v proxy.MacVerifier) Flow {
return Flow{
inboundDatagrams: make(chan []byte),
congestion: c,
v: v,
}
}
func (f *InitiatedFlow) Reconnect(ctx context.Context) error {
f.mu.Lock()
defer f.mu.Unlock()
if f.isAlive {
return nil
}
localAddr, err := net.ResolveUDPAddr("udp", f.Local())
if err != nil {
return err
}
remoteAddr, err := net.ResolveUDPAddr("udp", f.Remote)
if err != nil {
return err
}
conn, err := net.DialUDP("udp", localAddr, remoteAddr)
if err != nil {
return err
}
f.writer = conn
f.startup = true
// prod the connection once a second until we get an ack, then consider it alive
go func() {
seq, err := f.congestion.Sequence(ctx)
if err != nil {
return
}
for !f.isAlive {
if ctx.Err() != nil {
return
}
p := Packet{
ack: 0,
nack: 0,
seq: seq,
data: proxy.SimplePacket(nil),
}
_ = f.sendPacket(p, f.g)
time.Sleep(1 * time.Second)
}
}()
go func() {
_, _ = f.produceInternal(ctx, f.v, false)
}()
go f.earlyUpdateLoop(ctx, f.g, f.keepalive)
if err := f.readQueuePacket(ctx, conn); err != nil {
return err
}
f.isAlive = true
f.startup = false
go func() {
lockedAccept := func() {
f.mu.RLock()
defer f.mu.RUnlock()
if err := f.readQueuePacket(ctx, conn); err != nil {
log.Println(err)
}
}
for f.isAlive {
log.Println("alive and listening for packets")
lockedAccept()
}
log.Println("no longer alive")
}()
return nil
}
func (f *InitiatedFlow) Consume(ctx context.Context, p proxy.Packet, g proxy.MacGenerator) error {
f.mu.RLock()
defer f.mu.RUnlock()
return f.Flow.Consume(ctx, p, g)
}
func (f *InitiatedFlow) Produce(ctx context.Context, v proxy.MacVerifier) (proxy.Packet, error) {
f.mu.RLock()
defer f.mu.RUnlock()
return f.Flow.Produce(ctx, v)
}
func (f *Flow) IsAlive() bool {
return f.isAlive
}
func (f *Flow) Consume(ctx context.Context, pp proxy.Packet, g proxy.MacGenerator) error {
if !f.isAlive {
return shared.ErrDeadConnection
}
log.Println(f.congestion)
// Sequence is the congestion controllers opportunity to block
log.Println("awaiting sequence")
seq, err := f.congestion.Sequence(ctx)
if err != nil {
return err
}
log.Println("received sequence")
// Choose up to date ACK/NACK even after blocking
p := Packet{
seq: seq,
data: pp,
ack: f.congestion.NextAck(),
nack: f.congestion.NextNack(),
}
return f.sendPacket(p, g)
}
func (f *Flow) Produce(ctx context.Context, v proxy.MacVerifier) (proxy.Packet, error) {
if !f.isAlive {
return nil, shared.ErrDeadConnection
}
return f.produceInternal(ctx, v, true)
}
func (f *Flow) produceInternal(ctx context.Context, v proxy.MacVerifier, mustReturn bool) (proxy.Packet, error) {
for once := true; mustReturn || once; once = false {
log.Println(f.congestion)
var received []byte
select {
case received = <-f.inboundDatagrams:
case <-ctx.Done():
return nil, ctx.Err()
}
b, err := proxy.StripMac(received, v)
if err != nil {
return nil, err
}
p, err := UnmarshalPacket(b)
if err != nil {
return nil, err
}
// adjust congestion control based on this packet's congestion header
f.congestion.ReceivedPacket(p.seq, p.nack, p.ack)
// 12 bytes for header + the MAC + a timestamp
if len(b) == 12+f.v.CodeLength()+8 {
log.Println("handled keepalive/ack only packet")
continue
}
return p, nil
}
return nil, nil
}
func (f *Flow) queueDatagram(ctx context.Context, p []byte) error {
select {
case f.inboundDatagrams <- p:
return nil
case <-ctx.Done():
return ctx.Err()
}
}
func (f *Flow) sendPacket(p Packet, g proxy.MacGenerator) error {
b := p.Marshal()
b = proxy.AppendMac(b, g)
if f.raddr == nil {
_, err := f.writer.Write(b)
return err
} else {
_, err := f.writer.WriteToUDP(b, f.raddr)
return err
}
}
func (f *Flow) earlyUpdateLoop(ctx context.Context, g proxy.MacGenerator, keepalive time.Duration) {
for f.isAlive {
seq, err := f.congestion.AwaitEarlyUpdate(ctx, keepalive)
if err != nil {
fmt.Printf("terminating earlyupdateloop for `%v`\n", f)
return
}
p := Packet{
seq: seq,
data: proxy.SimplePacket(nil),
ack: f.congestion.NextAck(),
nack: f.congestion.NextNack(),
}
err = f.sendPacket(p, g)
if err != nil {
fmt.Printf("error sending early update packet: `%v`\n", err)
}
}
}
func (f *Flow) readQueuePacket(ctx context.Context, c PacketConn) error {
// TODO: Replace 6000 with MTU+header size
buf := make([]byte, 6000)
n, _, err := c.ReadFromUDP(buf)
if err != nil {
return err
}
return f.queueDatagram(ctx, buf[:n])
}

86
udp/flow_test.go Normal file
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package udp
import (
"context"
"fmt"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
"mpbl3p/mocks"
"mpbl3p/proxy"
"mpbl3p/udp/congestion"
"testing"
"time"
)
func TestFlow_Consume(t *testing.T) {
testContent := []byte("A test string is the content of this packet.")
testPacket := proxy.SimplePacket(testContent)
testMac := mocks.AlmostUselessMac{}
t.Run("Length", func(t *testing.T) {
testConn := mocks.NewMockPerfectBiPacketConn(10)
flowA := newFlow(congestion.NewNone(), testMac)
flowA.writer = testConn.SideB()
flowA.isAlive = true
err := flowA.Consume(context.Background(), testPacket, testMac)
require.Nil(t, err)
buf := make([]byte, 100)
n, _, err := testConn.SideA().ReadFromUDP(buf)
require.Nil(t, err)
// 12 header, 8 timestamp, 4 MAC
assert.Equal(t, len(testContent)+12+8+4, n)
})
}
func TestFlow_Produce(t *testing.T) {
testContent := []byte("A test string is the content of this packet.")
testPacket := Packet{
ack: 42,
nack: 26,
seq: 128,
data: proxy.SimplePacket(testContent),
}
testMac := mocks.AlmostUselessMac{}
testMarshalled := proxy.AppendMac(testPacket.Marshal(), testMac)
t.Run("Length", func(t *testing.T) {
done := make(chan struct{})
go func() {
testConn := mocks.NewMockPerfectBiPacketConn(10)
_, err := testConn.SideA().Write(testMarshalled)
require.Nil(t, err)
flowA := newFlow(congestion.NewNone(), testMac)
flowA.writer = testConn.SideB()
flowA.isAlive = true
go func() {
err := flowA.readQueuePacket(context.Background(), testConn.SideB())
assert.Nil(t, err)
}()
p, err := flowA.Produce(context.Background(), testMac)
require.Nil(t, err)
assert.Len(t, p.Contents(), len(testContent))
done <- struct{}{}
}()
timer := time.NewTimer(500 * time.Millisecond)
select {
case <-done:
case <-timer.C:
fmt.Println("timed out")
t.FailNow()
}
})
}

104
udp/listener.go Normal file
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package udp
import (
"context"
"log"
"mpbl3p/proxy"
"net"
"time"
)
type ComparableUdpAddress struct {
IP [16]byte
Port int
Zone string
}
func fromUdpAddress(address net.UDPAddr) ComparableUdpAddress {
var ip [16]byte
for i, b := range []byte(address.IP) {
ip[i] = b
}
return ComparableUdpAddress{
IP: ip,
Port: address.Port,
Zone: address.Zone,
}
}
func NewListener(ctx context.Context, p *proxy.Proxy, local string, v func() proxy.MacVerifier, g func() proxy.MacGenerator, c func() Congestion, enableConsumers bool, enableProducers bool) error {
laddr, err := net.ResolveUDPAddr("udp", local)
if err != nil {
return err
}
pconn, err := net.ListenUDP("udp", laddr)
if err != nil {
return err
}
err = pconn.SetWriteBuffer(0)
if err != nil {
panic(err)
}
receivedConnections := make(map[ComparableUdpAddress]*Flow)
go func() {
for ctx.Err() == nil {
buf := make([]byte, 6000)
if err := pconn.SetReadDeadline(time.Now().Add(time.Second)); err != nil {
panic(err)
}
n, addr, err := pconn.ReadFromUDP(buf)
if err != nil {
if e, ok := err.(net.Error); ok && e.Timeout() {
continue
}
panic(err)
}
raddr := fromUdpAddress(*addr)
if f, exists := receivedConnections[raddr]; exists {
log.Println("existing flow. queuing...")
if err := f.queueDatagram(ctx, buf[:n]); err != nil {
}
log.Println("queued")
continue
}
v := v()
g := g()
f := newFlow(c(), v)
f.writer = pconn
f.raddr = addr
f.isAlive = true
log.Printf("received new udp connection: %v\n", f)
go f.earlyUpdateLoop(ctx, g, 0)
receivedConnections[raddr] = &f
if enableConsumers {
p.AddConsumer(ctx, &f, g)
}
if enableProducers {
p.AddProducer(ctx, &f, v)
}
log.Println("handling...")
if err := f.queueDatagram(ctx, buf[:n]); err != nil {
return
}
log.Println("handled")
}
}()
return nil
}

43
udp/packet.go Normal file
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package udp
import (
"encoding/binary"
"mpbl3p/proxy"
"mpbl3p/shared"
)
type Packet struct {
ack uint32
nack uint32
seq uint32
data proxy.Packet
}
func UnmarshalPacket(b []byte) (p Packet, err error) {
if len(b) < 12 {
return Packet{}, shared.ErrNotEnoughBytes
}
p.ack = binary.LittleEndian.Uint32(b[0:4])
p.nack = binary.LittleEndian.Uint32(b[4:8])
p.seq = binary.LittleEndian.Uint32(b[8:12])
p.data = proxy.SimplePacket(b[12:])
return p, nil
}
func (p Packet) Marshal() []byte {
data := p.data.Marshal()
header := make([]byte, 12)
binary.LittleEndian.PutUint32(header[0:4], p.ack)
binary.LittleEndian.PutUint32(header[4:8], p.nack)
binary.LittleEndian.PutUint32(header[8:12], p.seq)
return append(header, data...)
}
func (p Packet) Contents() []byte {
return p.data.Contents()
}

59
udp/packet_test.go Normal file
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@ -0,0 +1,59 @@
package udp
import (
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
"mpbl3p/proxy"
"testing"
)
func TestPacket_Marshal(t *testing.T) {
testContent := []byte("A test string is the content of this packet.")
testPacket := Packet{
ack: 18,
nack: 29,
seq: 431,
data: proxy.SimplePacket(testContent),
}
t.Run("Length", func(t *testing.T) {
marshalled := testPacket.Marshal()
// 12 header + 8 timestamp
assert.Len(t, marshalled, len(testContent)+12)
})
}
func TestUnmarshalPacket(t *testing.T) {
testContent := []byte("A test string is the content of this packet.")
testPacket := Packet{
ack: 18,
nack: 29,
seq: 431,
data: proxy.SimplePacket(testContent),
}
testMarshalled := testPacket.Marshal()
t.Run("Length", func(t *testing.T) {
p, err := UnmarshalPacket(testMarshalled)
require.Nil(t, err)
assert.Len(t, p.Contents(), len(testContent))
})
t.Run("Contents", func(t *testing.T) {
p, err := UnmarshalPacket(testMarshalled)
require.Nil(t, err)
assert.Equal(t, p.Contents(), testContent)
})
t.Run("Header", func(t *testing.T) {
p, err := UnmarshalPacket(testMarshalled)
require.Nil(t, err)
assert.Equal(t, p.ack, uint32(18))
assert.Equal(t, p.nack, uint32(29))
assert.Equal(t, p.seq, uint32(431))
})
}

36
udp/wireshark_dissector.lua Normal file
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@ -0,0 +1,36 @@
mpbl3p_udp = Proto("mpbl3p_udp", "Multi Path Proxy Custom UDP")
ack_F = ProtoField.uint32("mpbl3p_udp.ack", "Acknowledgement")
nack_F = ProtoField.uint32("mpbl3p_udp.nack", "Negative Acknowledgement")
seq_F = ProtoField.uint32("mpbl3p_udp.seq", "Sequence Number")
time_F = ProtoField.absolute_time("mpbl3p_udp.time", "Timestamp")
proxied_F = ProtoField.bytes("mpbl3p_udp.data", "Proxied Data")
mpbl3p_udp.fields = { ack_F, nack_F, seq_F, time_F, proxied_F }
function mpbl3p_udp.dissector(buffer, pinfo, tree)
if buffer:len() < 20 then
return
end
pinfo.cols.protocol = "MPBL3P_UDP"
local ack = buffer(0, 4):le_uint()
local nack = buffer(4, 4):le_uint()
local seq = buffer(8, 4):le_uint()
local unix_time = buffer(buffer:len() - 8, 8):le_uint64()
local subtree = tree:add(mpbl3p_udp, buffer(), "Multi Path Proxy Header, SEQ: " .. seq .. " ACK: " .. ack .. " NACK: " .. nack)
subtree:add(ack_F, ack)
subtree:add(nack_F, nack)
subtree:add(seq_F, seq)
subtree:add(time_F, NSTime.new(unix_time:tonumber()))
if buffer:len() > 20 then
subtree:add(proxied_F, buffer(12, buffer:len() - 12 - 8))
end
end
DissectorTable.get("udp.port"):add(4724, mpbl3p_udp)
DissectorTable.get("udp.port"):add(4725, mpbl3p_udp)

13
utils/utils.go
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@ -1,13 +0,0 @@
package utils
var NextId = make(chan int)
func init() {
go func() {
i := 0
for {
NextId <- i
i += 1
}
}()
}