nebula/hostmap.go

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2019-11-19 10:00:20 -07:00
package nebula
import (
"encoding/json"
"errors"
"fmt"
"net"
"sync"
"time"
"github.com/rcrowley/go-metrics"
"github.com/sirupsen/logrus"
"github.com/slackhq/nebula/cert"
)
//const ProbeLen = 100
const PromoteEvery = 1000
const MaxRemotes = 10
// How long we should prevent roaming back to the previous IP.
// This helps prevent flapping due to packets already in flight
const RoamingSupressSeconds = 2
type HostMap struct {
sync.RWMutex //Because we concurrently read and write to our maps
name string
Indexes map[uint32]*HostInfo
Hosts map[uint32]*HostInfo
preferredRanges []*net.IPNet
vpnCIDR *net.IPNet
defaultRoute uint32
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unsafeRoutes *CIDRTree
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}
type HostInfo struct {
remote *udpAddr
Remotes []*HostInfoDest
promoteCounter uint32
ConnectionState *ConnectionState
handshakeStart time.Time
HandshakeReady bool
HandshakeCounter int
HandshakeComplete bool
HandshakePacket map[uint8][]byte
packetStore []*cachedPacket
remoteIndexId uint32
localIndexId uint32
hostId uint32
recvError int
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remoteCidr *CIDRTree
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lastRoam time.Time
lastRoamRemote *udpAddr
}
type cachedPacket struct {
messageType NebulaMessageType
messageSubType NebulaMessageSubType
callback packetCallback
packet []byte
}
type packetCallback func(t NebulaMessageType, st NebulaMessageSubType, h *HostInfo, p, nb, out []byte)
type HostInfoDest struct {
active bool
addr *udpAddr
//probes [ProbeLen]bool
probeCounter int
}
type Probe struct {
Addr *net.UDPAddr
Counter int
}
func NewHostMap(name string, vpnCIDR *net.IPNet, preferredRanges []*net.IPNet) *HostMap {
h := map[uint32]*HostInfo{}
i := map[uint32]*HostInfo{}
m := HostMap{
name: name,
Indexes: i,
Hosts: h,
preferredRanges: preferredRanges,
vpnCIDR: vpnCIDR,
defaultRoute: 0,
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unsafeRoutes: NewCIDRTree(),
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}
return &m
}
// UpdateStats takes a name and reports host and index counts to the stats collection system
func (hm *HostMap) EmitStats(name string) {
hm.RLock()
hostLen := len(hm.Hosts)
indexLen := len(hm.Indexes)
hm.RUnlock()
metrics.GetOrRegisterGauge("hostmap."+name+".hosts", nil).Update(int64(hostLen))
metrics.GetOrRegisterGauge("hostmap."+name+".indexes", nil).Update(int64(indexLen))
}
func (hm *HostMap) GetIndexByVpnIP(vpnIP uint32) (uint32, error) {
hm.RLock()
if i, ok := hm.Hosts[vpnIP]; ok {
index := i.localIndexId
hm.RUnlock()
return index, nil
}
hm.RUnlock()
return 0, errors.New("vpn IP not found")
}
func (hm *HostMap) GetVpnIPByIndex(index uint32) (uint32, error) {
hm.RLock()
if i, ok := hm.Indexes[index]; ok {
vpnIP := i.hostId
hm.RUnlock()
return vpnIP, nil
}
hm.RUnlock()
return 0, errors.New("vpn IP not found")
}
func (hm *HostMap) Add(ip uint32, hostinfo *HostInfo) {
hm.Lock()
hm.Hosts[ip] = hostinfo
hm.Unlock()
}
func (hm *HostMap) AddVpnIP(vpnIP uint32) *HostInfo {
h := &HostInfo{}
hm.RLock()
if _, ok := hm.Hosts[vpnIP]; !ok {
hm.RUnlock()
h = &HostInfo{
Remotes: []*HostInfoDest{},
promoteCounter: 0,
hostId: vpnIP,
HandshakePacket: make(map[uint8][]byte, 0),
}
hm.Lock()
hm.Hosts[vpnIP] = h
hm.Unlock()
return h
} else {
h = hm.Hosts[vpnIP]
hm.RUnlock()
return h
}
}
func (hm *HostMap) DeleteVpnIP(vpnIP uint32) {
hm.Lock()
delete(hm.Hosts, vpnIP)
if len(hm.Hosts) == 0 {
hm.Hosts = map[uint32]*HostInfo{}
}
hm.Unlock()
if l.Level >= logrus.DebugLevel {
l.WithField("hostMap", m{"mapName": hm.name, "vpnIp": IntIp(vpnIP), "mapTotalSize": len(hm.Hosts)}).
Debug("Hostmap vpnIp deleted")
}
}
func (hm *HostMap) AddIndex(index uint32, ci *ConnectionState) (*HostInfo, error) {
hm.Lock()
if _, ok := hm.Indexes[index]; !ok {
h := &HostInfo{
ConnectionState: ci,
Remotes: []*HostInfoDest{},
localIndexId: index,
HandshakePacket: make(map[uint8][]byte, 0),
}
hm.Indexes[index] = h
l.WithField("hostMap", m{"mapName": hm.name, "indexNumber": index, "mapTotalSize": len(hm.Indexes),
"hostinfo": m{"existing": false, "localIndexId": h.localIndexId, "hostId": IntIp(h.hostId)}}).
Debug("Hostmap index added")
hm.Unlock()
return h, nil
}
hm.Unlock()
return nil, fmt.Errorf("refusing to overwrite existing index: %d", index)
}
func (hm *HostMap) AddIndexHostInfo(index uint32, h *HostInfo) {
hm.Lock()
h.localIndexId = index
hm.Indexes[index] = h
hm.Unlock()
if l.Level > logrus.DebugLevel {
l.WithField("hostMap", m{"mapName": hm.name, "indexNumber": index, "mapTotalSize": len(hm.Indexes),
"hostinfo": m{"existing": true, "localIndexId": h.localIndexId, "hostId": IntIp(h.hostId)}}).
Debug("Hostmap index added")
}
}
func (hm *HostMap) AddVpnIPHostInfo(vpnIP uint32, h *HostInfo) {
hm.Lock()
h.hostId = vpnIP
hm.Hosts[vpnIP] = h
hm.Unlock()
if l.Level > logrus.DebugLevel {
l.WithField("hostMap", m{"mapName": hm.name, "vpnIp": IntIp(vpnIP), "mapTotalSize": len(hm.Hosts),
"hostinfo": m{"existing": true, "localIndexId": h.localIndexId, "hostId": IntIp(h.hostId)}}).
Debug("Hostmap vpnIp added")
}
}
func (hm *HostMap) DeleteIndex(index uint32) {
hm.Lock()
delete(hm.Indexes, index)
if len(hm.Indexes) == 0 {
hm.Indexes = map[uint32]*HostInfo{}
}
hm.Unlock()
if l.Level >= logrus.DebugLevel {
l.WithField("hostMap", m{"mapName": hm.name, "indexNumber": index, "mapTotalSize": len(hm.Indexes)}).
Debug("Hostmap index deleted")
}
}
func (hm *HostMap) QueryIndex(index uint32) (*HostInfo, error) {
//TODO: we probably just want ot return bool instead of error, or at least a static error
hm.RLock()
if h, ok := hm.Indexes[index]; ok {
hm.RUnlock()
return h, nil
} else {
hm.RUnlock()
return nil, errors.New("unable to find index")
}
}
// This function needs to range because we don't keep a map of remote indexes.
func (hm *HostMap) QueryReverseIndex(index uint32) (*HostInfo, error) {
hm.RLock()
for _, h := range hm.Indexes {
if h.ConnectionState != nil && h.remoteIndexId == index {
hm.RUnlock()
return h, nil
}
}
for _, h := range hm.Hosts {
if h.ConnectionState != nil && h.remoteIndexId == index {
hm.RUnlock()
return h, nil
}
}
hm.RUnlock()
return nil, fmt.Errorf("unable to find reverse index or connectionstate nil in %s hostmap", hm.name)
}
func (hm *HostMap) AddRemote(vpnIp uint32, remote *udpAddr) *HostInfo {
hm.Lock()
i, v := hm.Hosts[vpnIp]
if v {
i.AddRemote(*remote)
} else {
i = &HostInfo{
Remotes: []*HostInfoDest{NewHostInfoDest(remote)},
promoteCounter: 0,
hostId: vpnIp,
HandshakePacket: make(map[uint8][]byte, 0),
}
i.remote = i.Remotes[0].addr
hm.Hosts[vpnIp] = i
l.WithField("hostMap", m{"mapName": hm.name, "vpnIp": IntIp(vpnIp), "udpAddr": remote, "mapTotalSize": len(hm.Hosts)}).
Debug("Hostmap remote ip added")
}
i.ForcePromoteBest(hm.preferredRanges)
hm.Unlock()
return i
}
func (hm *HostMap) QueryVpnIP(vpnIp uint32) (*HostInfo, error) {
return hm.queryVpnIP(vpnIp, nil)
}
// PromoteBestQueryVpnIP will attempt to lazily switch to the best remote every
// `PromoteEvery` calls to this function for a given host.
func (hm *HostMap) PromoteBestQueryVpnIP(vpnIp uint32, ifce *Interface) (*HostInfo, error) {
return hm.queryVpnIP(vpnIp, ifce)
}
func (hm *HostMap) queryVpnIP(vpnIp uint32, promoteIfce *Interface) (*HostInfo, error) {
hm.RLock()
if h, ok := hm.Hosts[vpnIp]; ok {
if promoteIfce != nil {
h.TryPromoteBest(hm.preferredRanges, promoteIfce)
}
//fmt.Println(h.remote)
hm.RUnlock()
return h, nil
} else {
//return &net.UDPAddr{}, nil, errors.New("Unable to find host")
hm.RUnlock()
/*
if lightHouse != nil {
lightHouse.Query(vpnIp)
return nil, errors.New("Unable to find host")
}
*/
return nil, errors.New("unable to find host")
}
}
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func (hm *HostMap) queryUnsafeRoute(ip uint32) uint32 {
r := hm.unsafeRoutes.MostSpecificContains(ip)
if r != nil {
return r.(uint32)
} else {
return 0
}
}
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func (hm *HostMap) CheckHandshakeCompleteIP(vpnIP uint32) bool {
hm.RLock()
if i, ok := hm.Hosts[vpnIP]; ok {
if i == nil {
hm.RUnlock()
return false
}
complete := i.HandshakeComplete
hm.RUnlock()
return complete
}
hm.RUnlock()
return false
}
func (hm *HostMap) CheckHandshakeCompleteIndex(index uint32) bool {
hm.RLock()
if i, ok := hm.Indexes[index]; ok {
if i == nil {
hm.RUnlock()
return false
}
complete := i.HandshakeComplete
hm.RUnlock()
return complete
}
hm.RUnlock()
return false
}
func (hm *HostMap) ClearRemotes(vpnIP uint32) {
hm.Lock()
i := hm.Hosts[vpnIP]
if i == nil {
hm.Unlock()
return
}
i.remote = nil
i.Remotes = nil
hm.Unlock()
}
func (hm *HostMap) SetDefaultRoute(ip uint32) {
hm.defaultRoute = ip
}
func (hm *HostMap) PunchList() []*udpAddr {
var list []*udpAddr
hm.RLock()
for _, v := range hm.Hosts {
for _, r := range v.Remotes {
list = append(list, r.addr)
}
// if h, ok := hm.Hosts[vpnIp]; ok {
// hm.Hosts[vpnIp].PromoteBest(hm.preferredRanges, false)
//fmt.Println(h.remote)
// }
}
hm.RUnlock()
return list
}
func (hm *HostMap) Punchy(conn *udpConn) {
for {
for _, addr := range hm.PunchList() {
conn.WriteTo([]byte{1}, addr)
}
time.Sleep(time.Second * 30)
}
}
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func (hm *HostMap) addUnsafeRoutes(routes *[]route) {
for _, r := range *routes {
l.WithField("route", r.route).WithField("via", r.via).Error("Adding UNSAFE Route")
hm.unsafeRoutes.AddCIDR(r.route, ip2int(*r.via))
}
}
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func (i *HostInfo) MarshalJSON() ([]byte, error) {
return json.Marshal(m{
"remote": i.remote,
"remotes": i.Remotes,
"promote_counter": i.promoteCounter,
"connection_state": i.ConnectionState,
"handshake_start": i.handshakeStart,
"handshake_ready": i.HandshakeReady,
"handshake_counter": i.HandshakeCounter,
"handshake_complete": i.HandshakeComplete,
"handshake_packet": i.HandshakePacket,
"packet_store": i.packetStore,
"remote_index": i.remoteIndexId,
"local_index": i.localIndexId,
"host_id": int2ip(i.hostId),
"receive_errors": i.recvError,
"last_roam": i.lastRoam,
"last_roam_remote": i.lastRoamRemote,
})
}
func (i *HostInfo) BindConnectionState(cs *ConnectionState) {
i.ConnectionState = cs
}
func (i *HostInfo) TryPromoteBest(preferredRanges []*net.IPNet, ifce *Interface) {
if i.remote == nil {
i.ForcePromoteBest(preferredRanges)
return
}
i.promoteCounter++
if i.promoteCounter%PromoteEvery == 0 {
// return early if we are already on a preferred remote
rIP := udp2ip(i.remote)
for _, l := range preferredRanges {
if l.Contains(rIP) {
return
}
}
// We re-query the lighthouse periodically while sending packets, so
// check for new remotes in our local lighthouse cache
ips := ifce.lightHouse.QueryCache(i.hostId)
for _, ip := range ips {
i.AddRemote(ip)
}
best, preferred := i.getBestRemote(preferredRanges)
if preferred && !best.Equals(i.remote) {
// Try to send a test packet to that host, this should
// cause it to detect a roaming event and switch remotes
ifce.send(test, testRequest, i.ConnectionState, i, best, []byte(""), make([]byte, 12, 12), make([]byte, mtu))
}
}
}
func (i *HostInfo) ForcePromoteBest(preferredRanges []*net.IPNet) {
best, _ := i.getBestRemote(preferredRanges)
if best != nil {
i.remote = best
}
}
func (i *HostInfo) getBestRemote(preferredRanges []*net.IPNet) (best *udpAddr, preferred bool) {
if len(i.Remotes) > 0 {
for _, r := range i.Remotes {
rIP := udp2ip(r.addr)
for _, l := range preferredRanges {
if l.Contains(rIP) {
return r.addr, true
}
}
if best == nil || !PrivateIP(rIP) {
best = r.addr
}
/*
for _, r := range i.Remotes {
// Must have > 80% probe success to be considered.
//fmt.Println("GRADE:", r.addr.IP, r.Grade())
if r.Grade() > float64(.8) {
if localToMe.Contains(r.addr.IP) == true {
best = r.addr
break
//i.remote = i.Remotes[c].addr
} else {
//}
}
*/
}
return best, false
}
return nil, false
}
// rotateRemote will move remote to the next ip in the list of remote ips for this host
// This is different than PromoteBest in that what is algorithmically best may not actually work.
// Only known use case is when sending a stage 0 handshake.
// It may be better to just send stage 0 handshakes to all known ips and sort it out in the receiver.
func (i *HostInfo) rotateRemote() {
// We have 0, can't rotate
if len(i.Remotes) < 1 {
return
}
if i.remote == nil {
i.remote = i.Remotes[0].addr
return
}
// We want to look at all but the very last entry since that is handled at the end
for x := 0; x < len(i.Remotes)-1; x++ {
// Find our current position and move to the next one in the list
if i.Remotes[x].addr.Equals(i.remote) {
i.remote = i.Remotes[x+1].addr
return
}
}
// Our current position was likely the last in the list, start over at 0
i.remote = i.Remotes[0].addr
}
func (i *HostInfo) cachePacket(t NebulaMessageType, st NebulaMessageSubType, packet []byte, f packetCallback) {
//TODO: return the error so we can log with more context
if len(i.packetStore) < 100 {
tempPacket := make([]byte, len(packet))
copy(tempPacket, packet)
//l.WithField("trace", string(debug.Stack())).Error("Caching packet", tempPacket)
i.packetStore = append(i.packetStore, &cachedPacket{t, st, f, tempPacket})
l.WithField("vpnIp", IntIp(i.hostId)).
WithField("length", len(i.packetStore)).
WithField("stored", true).
Debugf("Packet store")
} else if l.Level >= logrus.DebugLevel {
l.WithField("vpnIp", IntIp(i.hostId)).
WithField("length", len(i.packetStore)).
WithField("stored", false).
Debugf("Packet store")
}
}
// handshakeComplete will set the connection as ready to communicate, as well as flush any stored packets
func (i *HostInfo) handshakeComplete() {
//TODO: I'm not certain the distinction between handshake complete and ConnectionState being ready matters because:
//TODO: HandshakeComplete means send stored packets and ConnectionState.ready means we are ready to send
//TODO: if the transition from HandhsakeComplete to ConnectionState.ready happens all within this function they are identical
i.ConnectionState.queueLock.Lock()
i.HandshakeComplete = true
//TODO: this should be managed by the handshake state machine to set it based on how many handshake were seen.
// Clamping it to 2 gets us out of the woods for now
*i.ConnectionState.messageCounter = 2
l.WithField("vpnIp", IntIp(i.hostId)).Debugf("Sending %d stored packets", len(i.packetStore))
nb := make([]byte, 12, 12)
out := make([]byte, mtu)
for _, cp := range i.packetStore {
cp.callback(cp.messageType, cp.messageSubType, i, cp.packet, nb, out)
}
i.packetStore = make([]*cachedPacket, 0)
i.ConnectionState.ready = true
i.ConnectionState.queueLock.Unlock()
i.ConnectionState.certState = nil
}
func (i *HostInfo) RemoteUDPAddrs() []*udpAddr {
var addrs []*udpAddr
for _, r := range i.Remotes {
addrs = append(addrs, r.addr)
}
return addrs
}
func (i *HostInfo) GetCert() *cert.NebulaCertificate {
if i.ConnectionState != nil {
return i.ConnectionState.peerCert
}
return nil
}
func (i *HostInfo) AddRemote(r udpAddr) *udpAddr {
remote := &r
//add := true
for _, r := range i.Remotes {
if r.addr.Equals(remote) {
return r.addr
//add = false
}
}
// Trim this down if necessary
if len(i.Remotes) > MaxRemotes {
i.Remotes = i.Remotes[len(i.Remotes)-MaxRemotes:]
}
i.Remotes = append(i.Remotes, NewHostInfoDest(remote))
return remote
//l.Debugf("Added remote %s for vpn ip", remote)
}
func (i *HostInfo) SetRemote(remote udpAddr) {
i.remote = i.AddRemote(remote)
}
func (i *HostInfo) ClearRemotes() {
i.remote = nil
i.Remotes = []*HostInfoDest{}
}
func (i *HostInfo) ClearConnectionState() {
i.ConnectionState = nil
}
func (i *HostInfo) RecvErrorExceeded() bool {
if i.recvError < 3 {
i.recvError += 1
return false
}
return true
}
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func (i *HostInfo) CreateRemoteCIDR(c *cert.NebulaCertificate) {
remoteCidr := NewCIDRTree()
for _, ip := range c.Details.Ips {
remoteCidr.AddCIDR(&net.IPNet{IP: ip.IP, Mask: net.IPMask{255, 255, 255, 255}}, struct{}{})
}
for _, n := range c.Details.Subnets {
remoteCidr.AddCIDR(n, struct{}{})
}
i.remoteCidr = remoteCidr
}
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//########################
func NewHostInfoDest(addr *udpAddr) *HostInfoDest {
i := &HostInfoDest{
addr: addr,
}
return i
}
func (hid *HostInfoDest) MarshalJSON() ([]byte, error) {
return json.Marshal(m{
"active": hid.active,
"address": hid.addr,
"probe_count": hid.probeCounter,
})
}
/*
func (hm *HostMap) DebugRemotes(vpnIp uint32) string {
s := "\n"
for _, h := range hm.Hosts {
for _, r := range h.Remotes {
s += fmt.Sprintf("%s : %d ## %v\n", r.addr.IP.String(), r.addr.Port, r.probes)
}
}
return s
}
func (d *HostInfoDest) Grade() float64 {
c1 := ProbeLen
for n := len(d.probes) - 1; n >= 0; n-- {
if d.probes[n] == true {
c1 -= 1
}
}
return float64(c1) / float64(ProbeLen)
}
func (d *HostInfoDest) Grade() (float64, float64, float64) {
c1 := ProbeLen
c2 := ProbeLen / 2
c2c := ProbeLen - ProbeLen/2
c3 := ProbeLen / 5
c3c := ProbeLen - ProbeLen/5
for n := len(d.probes) - 1; n >= 0; n-- {
if d.probes[n] == true {
c1 -= 1
if n >= c2c {
c2 -= 1
if n >= c3c {
c3 -= 1
}
}
}
//if n >= d {
}
return float64(c3) / float64(ProbeLen/5), float64(c2) / float64(ProbeLen/2), float64(c1) / float64(ProbeLen)
//return float64(c1) / float64(ProbeLen), float64(c2) / float64(ProbeLen/2), float64(c3) / float64(ProbeLen/5)
}
func (i *HostInfo) HandleReply(addr *net.UDPAddr, counter int) {
for _, r := range i.Remotes {
if r.addr.IP.Equal(addr.IP) && r.addr.Port == addr.Port {
r.ProbeReceived(counter)
}
}
}
func (i *HostInfo) Probes() []*Probe {
p := []*Probe{}
for _, d := range i.Remotes {
p = append(p, &Probe{Addr: d.addr, Counter: d.Probe()})
}
return p
}
func (d *HostInfoDest) Probe() int {
//d.probes = append(d.probes, true)
d.probeCounter++
d.probes[d.probeCounter%ProbeLen] = true
return d.probeCounter
//return d.probeCounter
}
func (d *HostInfoDest) ProbeReceived(probeCount int) {
if probeCount >= (d.probeCounter - ProbeLen) {
//fmt.Println("PROBE WORKED", probeCount)
//fmt.Println(d.addr, d.Grade())
d.probes[probeCount%ProbeLen] = false
}
}
*/
// Utility functions
func localIps() *[]net.IP {
//FIXME: This function is pretty garbage
var ips []net.IP
ifaces, _ := net.Interfaces()
for _, i := range ifaces {
addrs, _ := i.Addrs()
for _, addr := range addrs {
var ip net.IP
switch v := addr.(type) {
case *net.IPNet:
//continue
ip = v.IP
case *net.IPAddr:
ip = v.IP
}
if ip.To4() != nil && ip.IsLoopback() == false {
ips = append(ips, ip)
}
}
}
return &ips
}
func PrivateIP(ip net.IP) bool {
private := false
_, private24BitBlock, _ := net.ParseCIDR("10.0.0.0/8")
_, private20BitBlock, _ := net.ParseCIDR("172.16.0.0/12")
_, private16BitBlock, _ := net.ParseCIDR("192.168.0.0/16")
private = private24BitBlock.Contains(ip) || private20BitBlock.Contains(ip) || private16BitBlock.Contains(ip)
return private
}