nebula/main.go

426 lines
14 KiB
Go

package nebula
import (
"encoding/binary"
"fmt"
"net"
"strconv"
"strings"
"time"
"github.com/sirupsen/logrus"
"github.com/slackhq/nebula/sshd"
"gopkg.in/yaml.v2"
)
// The caller should provide a real logger, we have one just in case
var l = logrus.New()
type m map[string]interface{}
func Main(config *Config, configTest bool, buildVersion string, logger *logrus.Logger, tunFd *int) (*Control, error) {
l = logger
l.Formatter = &logrus.TextFormatter{
FullTimestamp: true,
}
// Print the config if in test, the exit comes later
if configTest {
b, err := yaml.Marshal(config.Settings)
if err != nil {
return nil, err
}
// Print the final config
l.Println(string(b))
}
err := configLogger(config)
if err != nil {
return nil, NewContextualError("Failed to configure the logger", nil, err)
}
config.RegisterReloadCallback(func(c *Config) {
err := configLogger(c)
if err != nil {
l.WithError(err).Error("Failed to configure the logger")
}
})
// trustedCAs is currently a global, so loadCA operates on that global directly
trustedCAs, err = loadCAFromConfig(config)
if err != nil {
//The errors coming out of loadCA are already nicely formatted
return nil, NewContextualError("Failed to load ca from config", nil, err)
}
l.WithField("fingerprints", trustedCAs.GetFingerprints()).Debug("Trusted CA fingerprints")
cs, err := NewCertStateFromConfig(config)
if err != nil {
//The errors coming out of NewCertStateFromConfig are already nicely formatted
return nil, NewContextualError("Failed to load certificate from config", nil, err)
}
l.WithField("cert", cs.certificate).Debug("Client nebula certificate")
fw, err := NewFirewallFromConfig(cs.certificate, config)
if err != nil {
return nil, NewContextualError("Error while loading firewall rules", nil, err)
}
l.WithField("firewallHash", fw.GetRuleHash()).Info("Firewall started")
// TODO: make sure mask is 4 bytes
tunCidr := cs.certificate.Details.Ips[0]
routes, err := parseRoutes(config, tunCidr)
if err != nil {
return nil, NewContextualError("Could not parse tun.routes", nil, err)
}
unsafeRoutes, err := parseUnsafeRoutes(config, tunCidr)
if err != nil {
return nil, NewContextualError("Could not parse tun.unsafe_routes", nil, err)
}
ssh, err := sshd.NewSSHServer(l.WithField("subsystem", "sshd"))
wireSSHReload(ssh, config)
if config.GetBool("sshd.enabled", false) {
err = configSSH(ssh, config)
if err != nil {
return nil, NewContextualError("Error while configuring the sshd", nil, err)
}
}
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// All non system modifying configuration consumption should live above this line
// tun config, listeners, anything modifying the computer should be below
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
var routines int
// If `routines` is set, use that and ignore the specific values
if routines = config.GetInt("routines", 0); routines != 0 {
if routines < 1 {
routines = 1
}
if routines > 1 {
l.WithField("routines", routines).Info("Using multiple routines")
}
} else {
// deprecated and undocumented
tunQueues := config.GetInt("tun.routines", 1)
udpQueues := config.GetInt("listen.routines", 1)
if tunQueues > udpQueues {
routines = tunQueues
} else {
routines = udpQueues
}
if routines != 1 {
l.WithField("routines", routines).Warn("Setting tun.routines and listen.routines is deprecated. Use `routines` instead")
}
}
// EXPERIMENTAL
// Intentionally not documented yet while we do more testing and determine
// a good default value.
conntrackCacheTimeout := config.GetDuration("firewall.conntrack.routine_cache_timeout", 0)
if routines > 1 && !config.IsSet("firewall.conntrack.routine_cache_timeout") {
// Use a different default if we are running with multiple routines
conntrackCacheTimeout = 1 * time.Second
}
if conntrackCacheTimeout > 0 {
l.WithField("duration", conntrackCacheTimeout).Info("Using routine-local conntrack cache")
}
var tun Inside
if !configTest {
config.CatchHUP()
switch {
case config.GetBool("tun.disabled", false):
tun = newDisabledTun(tunCidr, config.GetInt("tun.tx_queue", 500), config.GetBool("stats.message_metrics", false), l)
case tunFd != nil:
tun, err = newTunFromFd(
*tunFd,
tunCidr,
config.GetInt("tun.mtu", DEFAULT_MTU),
routes,
unsafeRoutes,
config.GetInt("tun.tx_queue", 500),
)
default:
tun, err = newTun(
config.GetString("tun.dev", ""),
tunCidr,
config.GetInt("tun.mtu", DEFAULT_MTU),
routes,
unsafeRoutes,
config.GetInt("tun.tx_queue", 500),
routines > 1,
)
}
if err != nil {
return nil, NewContextualError("Failed to get a tun/tap device", nil, err)
}
}
// set up our UDP listener
udpConns := make([]*udpConn, routines)
port := config.GetInt("listen.port", 0)
if !configTest {
for i := 0; i < routines; i++ {
udpServer, err := NewListener(config.GetString("listen.host", "0.0.0.0"), port, routines > 1)
if err != nil {
return nil, NewContextualError("Failed to open udp listener", m{"queue": i}, err)
}
udpServer.reloadConfig(config)
udpConns[i] = udpServer
// If port is dynamic, discover it
if port == 0 {
uPort, err := udpServer.LocalAddr()
if err != nil {
return nil, NewContextualError("Failed to get listening port", nil, err)
}
port = int(uPort.Port)
}
}
}
// Set up my internal host map
var preferredRanges []*net.IPNet
rawPreferredRanges := config.GetStringSlice("preferred_ranges", []string{})
// First, check if 'preferred_ranges' is set and fallback to 'local_range'
if len(rawPreferredRanges) > 0 {
for _, rawPreferredRange := range rawPreferredRanges {
_, preferredRange, err := net.ParseCIDR(rawPreferredRange)
if err != nil {
return nil, NewContextualError("Failed to parse preferred ranges", nil, err)
}
preferredRanges = append(preferredRanges, preferredRange)
}
}
// local_range was superseded by preferred_ranges. If it is still present,
// merge the local_range setting into preferred_ranges. We will probably
// deprecate local_range and remove in the future.
rawLocalRange := config.GetString("local_range", "")
if rawLocalRange != "" {
_, localRange, err := net.ParseCIDR(rawLocalRange)
if err != nil {
return nil, NewContextualError("Failed to parse local_range", nil, err)
}
// Check if the entry for local_range was already specified in
// preferred_ranges. Don't put it into the slice twice if so.
var found bool
for _, r := range preferredRanges {
if r.String() == localRange.String() {
found = true
break
}
}
if !found {
preferredRanges = append(preferredRanges, localRange)
}
}
hostMap := NewHostMap("main", tunCidr, preferredRanges)
hostMap.SetDefaultRoute(ip2int(net.ParseIP(config.GetString("default_route", "0.0.0.0"))))
hostMap.addUnsafeRoutes(&unsafeRoutes)
hostMap.metricsEnabled = config.GetBool("stats.message_metrics", false)
l.WithField("network", hostMap.vpnCIDR).WithField("preferredRanges", hostMap.preferredRanges).Info("Main HostMap created")
/*
config.SetDefault("promoter.interval", 10)
go hostMap.Promoter(config.GetInt("promoter.interval"))
*/
punchy := NewPunchyFromConfig(config)
if punchy.Punch && !configTest {
l.Info("UDP hole punching enabled")
go hostMap.Punchy(udpConns[0])
}
amLighthouse := config.GetBool("lighthouse.am_lighthouse", false)
// warn if am_lighthouse is enabled but upstream lighthouses exists
rawLighthouseHosts := config.GetStringSlice("lighthouse.hosts", []string{})
if amLighthouse && len(rawLighthouseHosts) != 0 {
l.Warn("lighthouse.am_lighthouse enabled on node but upstream lighthouses exist in config")
}
lighthouseHosts := make([]uint32, len(rawLighthouseHosts))
for i, host := range rawLighthouseHosts {
ip := net.ParseIP(host)
if ip == nil {
return nil, NewContextualError("Unable to parse lighthouse host entry", m{"host": host, "entry": i + 1}, nil)
}
if !tunCidr.Contains(ip) {
return nil, NewContextualError("lighthouse host is not in our subnet, invalid", m{"vpnIp": ip, "network": tunCidr.String()}, nil)
}
lighthouseHosts[i] = ip2int(ip)
}
lightHouse := NewLightHouse(
amLighthouse,
ip2int(tunCidr.IP),
lighthouseHosts,
//TODO: change to a duration
config.GetInt("lighthouse.interval", 10),
uint32(port),
udpConns[0],
punchy.Respond,
punchy.Delay,
config.GetBool("stats.lighthouse_metrics", false),
)
remoteAllowList, err := config.GetAllowList("lighthouse.remote_allow_list", false)
if err != nil {
return nil, NewContextualError("Invalid lighthouse.remote_allow_list", nil, err)
}
lightHouse.SetRemoteAllowList(remoteAllowList)
localAllowList, err := config.GetAllowList("lighthouse.local_allow_list", true)
if err != nil {
return nil, NewContextualError("Invalid lighthouse.local_allow_list", nil, err)
}
lightHouse.SetLocalAllowList(localAllowList)
//TODO: Move all of this inside functions in lighthouse.go
for k, v := range config.GetMap("static_host_map", map[interface{}]interface{}{}) {
vpnIp := net.ParseIP(fmt.Sprintf("%v", k))
if !tunCidr.Contains(vpnIp) {
return nil, NewContextualError("static_host_map key is not in our subnet, invalid", m{"vpnIp": vpnIp, "network": tunCidr.String()}, nil)
}
vals, ok := v.([]interface{})
if ok {
for _, v := range vals {
parts := strings.Split(fmt.Sprintf("%v", v), ":")
addr, err := net.ResolveIPAddr("ip", parts[0])
if err == nil {
ip := addr.IP
port, err := strconv.Atoi(parts[1])
if err != nil {
return nil, NewContextualError("Static host address could not be parsed", m{"vpnIp": vpnIp}, err)
}
lightHouse.AddRemote(ip2int(vpnIp), NewUDPAddr(ip2int(ip), uint16(port)), true)
}
}
} else {
//TODO: make this all a helper
parts := strings.Split(fmt.Sprintf("%v", v), ":")
addr, err := net.ResolveIPAddr("ip", parts[0])
if err == nil {
ip := addr.IP
port, err := strconv.Atoi(parts[1])
if err != nil {
return nil, NewContextualError("Static host address could not be parsed", m{"vpnIp": vpnIp}, err)
}
lightHouse.AddRemote(ip2int(vpnIp), NewUDPAddr(ip2int(ip), uint16(port)), true)
}
}
}
err = lightHouse.ValidateLHStaticEntries()
if err != nil {
l.WithError(err).Error("Lighthouse unreachable")
}
var messageMetrics *MessageMetrics
if config.GetBool("stats.message_metrics", false) {
messageMetrics = newMessageMetrics()
} else {
messageMetrics = newMessageMetricsOnlyRecvError()
}
handshakeConfig := HandshakeConfig{
tryInterval: config.GetDuration("handshakes.try_interval", DefaultHandshakeTryInterval),
retries: config.GetInt("handshakes.retries", DefaultHandshakeRetries),
waitRotation: config.GetInt("handshakes.wait_rotation", DefaultHandshakeWaitRotation),
triggerBuffer: config.GetInt("handshakes.trigger_buffer", DefaultHandshakeTriggerBuffer),
messageMetrics: messageMetrics,
}
handshakeManager := NewHandshakeManager(tunCidr, preferredRanges, hostMap, lightHouse, udpConns[0], handshakeConfig)
lightHouse.handshakeTrigger = handshakeManager.trigger
//TODO: These will be reused for psk
//handshakeMACKey := config.GetString("handshake_mac.key", "")
//handshakeAcceptedMACKeys := config.GetStringSlice("handshake_mac.accepted_keys", []string{})
serveDns := config.GetBool("lighthouse.serve_dns", false)
checkInterval := config.GetInt("timers.connection_alive_interval", 5)
pendingDeletionInterval := config.GetInt("timers.pending_deletion_interval", 10)
ifConfig := &InterfaceConfig{
HostMap: hostMap,
Inside: tun,
Outside: udpConns[0],
certState: cs,
Cipher: config.GetString("cipher", "aes"),
Firewall: fw,
ServeDns: serveDns,
HandshakeManager: handshakeManager,
lightHouse: lightHouse,
checkInterval: checkInterval,
pendingDeletionInterval: pendingDeletionInterval,
DropLocalBroadcast: config.GetBool("tun.drop_local_broadcast", false),
DropMulticast: config.GetBool("tun.drop_multicast", false),
UDPBatchSize: config.GetInt("listen.batch", 64),
routines: routines,
MessageMetrics: messageMetrics,
version: buildVersion,
ConntrackCacheTimeout: conntrackCacheTimeout,
}
switch ifConfig.Cipher {
case "aes":
noiseEndianness = binary.BigEndian
case "chachapoly":
noiseEndianness = binary.LittleEndian
default:
return nil, fmt.Errorf("unknown cipher: %v", ifConfig.Cipher)
}
var ifce *Interface
if !configTest {
ifce, err = NewInterface(ifConfig)
if err != nil {
return nil, fmt.Errorf("failed to initialize interface: %s", err)
}
// TODO: Better way to attach these, probably want a new interface in InterfaceConfig
// I don't want to make this initial commit too far-reaching though
ifce.writers = udpConns
ifce.RegisterConfigChangeCallbacks(config)
go handshakeManager.Run(ifce)
go lightHouse.LhUpdateWorker(ifce)
}
err = startStats(config, configTest)
if err != nil {
return nil, NewContextualError("Failed to start stats emitter", nil, err)
}
if configTest {
return nil, nil
}
//TODO: check if we _should_ be emitting stats
go ifce.emitStats(config.GetDuration("stats.interval", time.Second*10))
attachCommands(ssh, hostMap, handshakeManager.pendingHostMap, lightHouse, ifce)
// Start DNS server last to allow using the nebula IP as lighthouse.dns.host
if amLighthouse && serveDns {
l.Debugln("Starting dns server")
go dnsMain(hostMap, config)
}
return &Control{ifce, l}, nil
}