nebula/main.go

335 lines
10 KiB
Go

package nebula
import (
"context"
"encoding/binary"
"errors"
"fmt"
"net"
"time"
"github.com/sirupsen/logrus"
"github.com/slackhq/nebula/config"
"github.com/slackhq/nebula/overlay"
"github.com/slackhq/nebula/sshd"
"github.com/slackhq/nebula/udp"
"github.com/slackhq/nebula/util"
"gopkg.in/yaml.v2"
)
type m map[string]interface{}
func Main(c *config.C, configTest bool, buildVersion string, logger *logrus.Logger, tunFd *int) (retcon *Control, reterr error) {
ctx, cancel := context.WithCancel(context.Background())
// Automatically cancel the context if Main returns an error, to signal all created goroutines to quit.
defer func() {
if reterr != nil {
cancel()
}
}()
l := logger
l.Formatter = &logrus.TextFormatter{
FullTimestamp: true,
}
// Print the config if in test, the exit comes later
if configTest {
b, err := yaml.Marshal(c.Settings)
if err != nil {
return nil, err
}
// Print the final config
l.Println(string(b))
}
err := configLogger(l, c)
if err != nil {
return nil, util.NewContextualError("Failed to configure the logger", nil, err)
}
c.RegisterReloadCallback(func(c *config.C) {
err := configLogger(l, c)
if err != nil {
l.WithError(err).Error("Failed to configure the logger")
}
})
caPool, err := loadCAFromConfig(l, c)
if err != nil {
//The errors coming out of loadCA are already nicely formatted
return nil, util.NewContextualError("Failed to load ca from config", nil, err)
}
l.WithField("fingerprints", caPool.GetFingerprints()).Debug("Trusted CA fingerprints")
cs, err := NewCertStateFromConfig(c)
if err != nil {
//The errors coming out of NewCertStateFromConfig are already nicely formatted
return nil, util.NewContextualError("Failed to load certificate from config", nil, err)
}
l.WithField("cert", cs.certificate).Debug("Client nebula certificate")
fw, err := NewFirewallFromConfig(l, cs.certificate, c)
if err != nil {
return nil, util.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]
ssh, err := sshd.NewSSHServer(l.WithField("subsystem", "sshd"))
wireSSHReload(l, ssh, c)
var sshStart func()
if c.GetBool("sshd.enabled", false) {
sshStart, err = configSSH(l, ssh, c)
if err != nil {
return nil, util.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 = c.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 := c.GetInt("tun.routines", 1)
udpQueues := c.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 := c.GetDuration("firewall.conntrack.routine_cache_timeout", 0)
if routines > 1 && !c.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 overlay.Device
if !configTest {
c.CatchHUP(ctx)
tun, err = overlay.NewDeviceFromConfig(c, l, tunCidr, tunFd, routines)
if err != nil {
return nil, util.NewContextualError("Failed to get a tun/tap device", nil, err)
}
defer func() {
if reterr != nil {
tun.Close()
}
}()
}
// set up our UDP listener
udpConns := make([]*udp.Conn, routines)
port := c.GetInt("listen.port", 0)
if !configTest {
for i := 0; i < routines; i++ {
udpServer, err := udp.NewListener(l, c.GetString("listen.host", "0.0.0.0"), port, routines > 1, c.GetInt("listen.batch", 64))
if err != nil {
return nil, util.NewContextualError("Failed to open udp listener", m{"queue": i}, err)
}
udpServer.ReloadConfig(c)
udpConns[i] = udpServer
}
}
// Set up my internal host map
var preferredRanges []*net.IPNet
rawPreferredRanges := c.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, util.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 := c.GetString("local_range", "")
if rawLocalRange != "" {
_, localRange, err := net.ParseCIDR(rawLocalRange)
if err != nil {
return nil, util.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(l, "main", tunCidr, preferredRanges)
hostMap.metricsEnabled = c.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(l, c)
if punchy.GetPunch() && !configTest {
l.Info("UDP hole punching enabled")
go hostMap.Punchy(ctx, udpConns[0])
}
lightHouse, err := NewLightHouseFromConfig(l, c, tunCidr, udpConns[0], punchy)
switch {
case errors.As(err, &util.ContextualError{}):
return nil, err
case err != nil:
return nil, util.NewContextualError("Failed to initialize lighthouse handler", nil, err)
}
var messageMetrics *MessageMetrics
if c.GetBool("stats.message_metrics", false) {
messageMetrics = newMessageMetrics()
} else {
messageMetrics = newMessageMetricsOnlyRecvError()
}
handshakeConfig := HandshakeConfig{
tryInterval: c.GetDuration("handshakes.try_interval", DefaultHandshakeTryInterval),
retries: c.GetInt("handshakes.retries", DefaultHandshakeRetries),
triggerBuffer: c.GetInt("handshakes.trigger_buffer", DefaultHandshakeTriggerBuffer),
messageMetrics: messageMetrics,
}
handshakeManager := NewHandshakeManager(l, 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 := false
if c.GetBool("lighthouse.serve_dns", false) {
if c.GetBool("lighthouse.am_lighthouse", false) {
serveDns = true
} else {
l.Warn("DNS server refusing to run because this host is not a lighthouse.")
}
}
checkInterval := c.GetInt("timers.connection_alive_interval", 5)
pendingDeletionInterval := c.GetInt("timers.pending_deletion_interval", 10)
ifConfig := &InterfaceConfig{
HostMap: hostMap,
Inside: tun,
Outside: udpConns[0],
certState: cs,
Cipher: c.GetString("cipher", "aes"),
Firewall: fw,
ServeDns: serveDns,
HandshakeManager: handshakeManager,
lightHouse: lightHouse,
checkInterval: checkInterval,
pendingDeletionInterval: pendingDeletionInterval,
DropLocalBroadcast: c.GetBool("tun.drop_local_broadcast", false),
DropMulticast: c.GetBool("tun.drop_multicast", false),
routines: routines,
MessageMetrics: messageMetrics,
version: buildVersion,
caPool: caPool,
disconnectInvalid: c.GetBool("pki.disconnect_invalid", false),
ConntrackCacheTimeout: conntrackCacheTimeout,
l: l,
}
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(ctx, 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(c)
go handshakeManager.Run(ctx, ifce)
go lightHouse.LhUpdateWorker(ctx, ifce)
}
// TODO - stats third-party modules start uncancellable goroutines. Update those libs to accept
// a context so that they can exit when the context is Done.
statsStart, err := startStats(l, c, buildVersion, configTest)
if err != nil {
return nil, util.NewContextualError("Failed to start stats emitter", nil, err)
}
if configTest {
return nil, nil
}
//TODO: check if we _should_ be emitting stats
go ifce.emitStats(ctx, c.GetDuration("stats.interval", time.Second*10))
attachCommands(l, ssh, hostMap, handshakeManager.pendingHostMap, lightHouse, ifce)
// Start DNS server last to allow using the nebula IP as lighthouse.dns.host
var dnsStart func()
if lightHouse.amLighthouse && serveDns {
l.Debugln("Starting dns server")
dnsStart = dnsMain(l, hostMap, c)
}
return &Control{ifce, l, cancel, sshStart, statsStart, dnsStart}, nil
}