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mirror of https://github.com/cwinfo/yggdrasil-go.git synced 2024-11-09 16:20:26 +00:00
yggdrasil-go/yggdrasil.go

278 lines
9.3 KiB
Go

package main
import (
"bytes"
"encoding/hex"
"encoding/json"
"flag"
"fmt"
"io/ioutil"
"log"
"math/rand"
"os"
"os/signal"
"regexp"
"syscall"
"time"
"golang.org/x/text/encoding/unicode"
"github.com/kardianos/minwinsvc"
"github.com/mitchellh/mapstructure"
"github.com/neilalexander/hjson-go"
"yggdrasil"
"yggdrasil/config"
"yggdrasil/defaults"
)
type nodeConfig = config.NodeConfig
type Core = yggdrasil.Core
type node struct {
core Core
}
// Generates default configuration. This is used when outputting the -genconf
// parameter and also when using -autoconf. The isAutoconf flag is used to
// determine whether the operating system should select a free port by itself
// (which guarantees that there will not be a conflict with any other services)
// or whether to generate a random port number. The only side effect of setting
// isAutoconf is that the TCP and UDP ports will likely end up with different
// port numbers.
func generateConfig(isAutoconf bool) *nodeConfig {
// Create a new core.
core := Core{}
// Generate encryption keys.
bpub, bpriv := core.NewEncryptionKeys()
spub, spriv := core.NewSigningKeys()
// Create a node configuration and populate it.
cfg := nodeConfig{}
if isAutoconf {
cfg.Listen = "[::]:0"
} else {
r1 := rand.New(rand.NewSource(time.Now().UnixNano()))
cfg.Listen = fmt.Sprintf("[::]:%d", r1.Intn(65534-32768)+32768)
}
cfg.AdminListen = defaults.GetDefaults().DefaultAdminListen
cfg.EncryptionPublicKey = hex.EncodeToString(bpub[:])
cfg.EncryptionPrivateKey = hex.EncodeToString(bpriv[:])
cfg.SigningPublicKey = hex.EncodeToString(spub[:])
cfg.SigningPrivateKey = hex.EncodeToString(spriv[:])
cfg.Peers = []string{}
cfg.InterfacePeers = map[string][]string{}
cfg.AllowedEncryptionPublicKeys = []string{}
cfg.MulticastInterfaces = []string{".*"}
cfg.IfName = defaults.GetDefaults().DefaultIfName
cfg.IfMTU = defaults.GetDefaults().DefaultIfMTU
cfg.IfTAPMode = defaults.GetDefaults().DefaultIfTAPMode
cfg.SessionFirewall.Enable = false
cfg.SessionFirewall.AllowFromDirect = true
cfg.SessionFirewall.AllowFromRemote = true
return &cfg
}
// Generates a new configuration and returns it in HJSON format. This is used
// with -genconf.
func doGenconf() string {
cfg := generateConfig(false)
bs, err := hjson.Marshal(cfg)
if err != nil {
panic(err)
}
return string(bs)
}
// The main function is responsible for configuring and starting Yggdrasil.
func main() {
// Configure the command line parameters.
genconf := flag.Bool("genconf", false, "print a new config to stdout")
useconf := flag.Bool("useconf", false, "read config from stdin")
useconffile := flag.String("useconffile", "", "read config from specified file path")
normaliseconf := flag.Bool("normaliseconf", false, "use in combination with either -useconf or -useconffile, outputs your configuration normalised")
autoconf := flag.Bool("autoconf", false, "automatic mode (dynamic IP, peer with IPv6 neighbors)")
flag.Parse()
var cfg *nodeConfig
switch {
case *autoconf:
// Use an autoconf-generated config, this will give us random keys and
// port numbers, and will use an automatically selected TUN/TAP interface.
cfg = generateConfig(true)
case *useconffile != "" || *useconf:
// Use a configuration file. If -useconf, the configuration will be read
// from stdin. If -useconffile, the configuration will be read from the
// filesystem.
var config []byte
var err error
if *useconffile != "" {
// Read the file from the filesystem
config, err = ioutil.ReadFile(*useconffile)
} else {
// Read the file from stdin.
config, err = ioutil.ReadAll(os.Stdin)
}
if err != nil {
panic(err)
}
// If there's a byte order mark - which Windows 10 is now incredibly fond of
// throwing everywhere when it's converting things into UTF-16 for the hell
// of it - remove it and decode back down into UTF-8. This is necessary
// because hjson doesn't know what to do with UTF-16 and will panic
if bytes.Compare(config[0:2], []byte{0xFF, 0xFE}) == 0 ||
bytes.Compare(config[0:2], []byte{0xFE, 0xFF}) == 0 {
utf := unicode.UTF16(unicode.BigEndian, unicode.UseBOM)
decoder := utf.NewDecoder()
config, err = decoder.Bytes(config)
if err != nil {
panic(err)
}
}
// Generate a new configuration - this gives us a set of sane defaults -
// then parse the configuration we loaded above on top of it. The effect
// of this is that any configuration item that is missing from the provided
// configuration will use a sane default.
cfg = generateConfig(false)
var dat map[string]interface{}
if err := hjson.Unmarshal(config, &dat); err != nil {
panic(err)
}
confJson, err := json.Marshal(dat)
if err != nil {
panic(err)
}
json.Unmarshal(confJson, &cfg)
// For now we will do a little bit to help the user adjust their
// configuration to match the new configuration format, as some of the key
// names have changed recently.
changes := map[string]string{
"Multicast": "",
"LinkLocal": "MulticastInterfaces",
"BoxPub": "EncryptionPublicKey",
"BoxPriv": "EncryptionPrivateKey",
"SigPub": "SigningPublicKey",
"SigPriv": "SigningPrivateKey",
"AllowedBoxPubs": "AllowedEncryptionPublicKeys",
}
// Loop over the mappings aove and see if we have anything to fix.
for from, to := range changes {
if _, ok := dat[from]; ok {
if to == "" {
if !*normaliseconf {
log.Println("Warning: Deprecated config option", from, "- please remove")
}
} else {
if !*normaliseconf {
log.Println("Warning: Deprecated config option", from, "- please rename to", to)
}
// If the configuration file doesn't already contain a line with the
// new name then set it to the old value. This makes sure that we
// don't overwrite something that was put there intentionally.
if _, ok := dat[to]; !ok {
dat[to] = dat[from]
}
}
}
}
// Overlay our newly mapped configuration onto the autoconf node config that
// we generated above.
if err = mapstructure.Decode(dat, &cfg); err != nil {
panic(err)
}
// If the -normaliseconf option was specified then remarshal the above
// configuration and print it back to stdout. This lets the user update
// their configuration file with newly mapped names (like above) or to
// convert from plain JSON to commented HJSON.
if *normaliseconf {
bs, err := hjson.Marshal(cfg)
if err != nil {
panic(err)
}
fmt.Println(string(bs))
return
}
case *genconf:
// Generate a new configuration and print it to stdout.
fmt.Println(doGenconf())
default:
// No flags were provided, therefore print the list of flags to stdout.
flag.PrintDefaults()
}
// Have we got a working configuration? If we don't then it probably means
// that neither -autoconf, -useconf or -useconffile were set above. Stop
// if we don't.
if cfg == nil {
return
}
// Create a new logger that logs output to stdout.
logger := log.New(os.Stdout, "", log.Flags())
// Setup the Yggdrasil node itself. The node{} type includes a Core, so we
// don't need to create this manually.
n := node{}
// Check to see if any multicast interface expressions were provided in the
// config. If they were then set them now.
for _, ll := range cfg.MulticastInterfaces {
ifceExpr, err := regexp.Compile(ll)
if err != nil {
panic(err)
}
n.core.AddMulticastInterfaceExpr(ifceExpr)
}
// Now that we have a working configuration, we can now actually start
// Yggdrasil. This will start the router, switch, DHT node, TCP and UDP
// sockets, TUN/TAP adapter and multicast discovery port.
if err := n.core.Start(cfg, logger); err != nil {
logger.Println("An error occurred during startup")
panic(err)
}
// Check to see if any allowed encryption keys were provided in the config.
// If they were then set them now.
for _, pBoxStr := range cfg.AllowedEncryptionPublicKeys {
n.core.AddAllowedEncryptionPublicKey(pBoxStr)
}
// If any static peers were provided in the configuration above then we should
// configure them. The loop ensures that disconnected peers will eventually
// be reconnected with.
go func() {
if len(cfg.Peers) == 0 && len(cfg.InterfacePeers) == 0 {
return
}
for {
for _, peer := range cfg.Peers {
n.core.AddPeer(peer, "")
time.Sleep(time.Second)
}
for intf, intfpeers := range cfg.InterfacePeers {
for _, peer := range intfpeers {
n.core.AddPeer(peer, intf)
time.Sleep(time.Second)
}
}
time.Sleep(time.Minute)
}
}()
// The Stop function ensures that the TUN/TAP adapter is correctly shut down
// before the program exits.
defer func() {
n.core.Stop()
}()
// Make some nice output that tells us what our IPv6 address and subnet are.
// This is just logged to stdout for the user.
address := n.core.GetAddress()
subnet := n.core.GetSubnet()
logger.Printf("Your IPv6 address is %s", address.String())
logger.Printf("Your IPv6 subnet is %s", subnet.String())
// Catch interrupts from the operating system to exit gracefully.
c := make(chan os.Signal, 1)
signal.Notify(c, os.Interrupt, syscall.SIGTERM)
// Create a function to capture the service being stopped on Windows.
winTerminate := func() {
c <- os.Interrupt
}
minwinsvc.SetOnExit(winTerminate)
// Wait for the terminate/interrupt signal. Once a signal is received, the
// deferred Stop function above will run which will shut down TUN/TAP.
<-c
}