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wgengine/magicsock,all: allocate peer relay over disco instead of PeerAPI (#16603)

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Updates tailscale/corp#30583
Updates tailscale/corp#30534
Updates tailscale/corp#30557

Signed-off-by: Dylan Bargatze <dylan@tailscale.com>
Signed-off-by: Jordan Whited <jordan@tailscale.com>
Co-authored-by: Dylan Bargatze <dylan@tailscale.com>
This commit is contained in:
Jordan Whited 2025-07-21 10:02:37 -07:00 committed by GitHub
parent 5d4e67fd93
commit 1677fb1905
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
16 changed files with 1290 additions and 743 deletions
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261
disco/disco.go
View File

@ -42,13 +42,15 @@ const NonceLen = 24
type MessageType byte
const (
TypePing = MessageType(0x01)
TypePong = MessageType(0x02)
TypeCallMeMaybe = MessageType(0x03)
TypeBindUDPRelayEndpoint = MessageType(0x04)
TypeBindUDPRelayEndpointChallenge = MessageType(0x05)
TypeBindUDPRelayEndpointAnswer = MessageType(0x06)
TypeCallMeMaybeVia = MessageType(0x07)
TypePing = MessageType(0x01)
TypePong = MessageType(0x02)
TypeCallMeMaybe = MessageType(0x03)
TypeBindUDPRelayEndpoint = MessageType(0x04)
TypeBindUDPRelayEndpointChallenge = MessageType(0x05)
TypeBindUDPRelayEndpointAnswer = MessageType(0x06)
TypeCallMeMaybeVia = MessageType(0x07)
TypeAllocateUDPRelayEndpointRequest = MessageType(0x08)
TypeAllocateUDPRelayEndpointResponse = MessageType(0x09)
)
const v0 = byte(0)
@ -97,6 +99,10 @@ func Parse(p []byte) (Message, error) {
return parseBindUDPRelayEndpointAnswer(ver, p)
case TypeCallMeMaybeVia:
return parseCallMeMaybeVia(ver, p)
case TypeAllocateUDPRelayEndpointRequest:
return parseAllocateUDPRelayEndpointRequest(ver, p)
case TypeAllocateUDPRelayEndpointResponse:
return parseAllocateUDPRelayEndpointResponse(ver, p)
default:
return nil, fmt.Errorf("unknown message type 0x%02x", byte(t))
}
@ -381,9 +387,7 @@ func (m *BindUDPRelayEndpointCommon) decode(b []byte) error {
}
// BindUDPRelayEndpoint is the first messaged transmitted from UDP relay client
// towards UDP relay server as part of the 3-way bind handshake. This message
// type is currently considered experimental and is not yet tied to a
// tailcfg.CapabilityVersion.
// towards UDP relay server as part of the 3-way bind handshake.
type BindUDPRelayEndpoint struct {
BindUDPRelayEndpointCommon
}
@ -405,8 +409,7 @@ func parseBindUDPRelayEndpoint(ver uint8, p []byte) (m *BindUDPRelayEndpoint, er
// BindUDPRelayEndpointChallenge is transmitted from UDP relay server towards
// UDP relay client in response to a BindUDPRelayEndpoint message as part of the
// 3-way bind handshake. This message type is currently considered experimental
// and is not yet tied to a tailcfg.CapabilityVersion.
// 3-way bind handshake.
type BindUDPRelayEndpointChallenge struct {
BindUDPRelayEndpointCommon
}
@ -427,9 +430,7 @@ func parseBindUDPRelayEndpointChallenge(ver uint8, p []byte) (m *BindUDPRelayEnd
}
// BindUDPRelayEndpointAnswer is transmitted from UDP relay client to UDP relay
// server in response to a BindUDPRelayEndpointChallenge message. This message
// type is currently considered experimental and is not yet tied to a
// tailcfg.CapabilityVersion.
// server in response to a BindUDPRelayEndpointChallenge message.
type BindUDPRelayEndpointAnswer struct {
BindUDPRelayEndpointCommon
}
@ -449,6 +450,168 @@ func parseBindUDPRelayEndpointAnswer(ver uint8, p []byte) (m *BindUDPRelayEndpoi
return m, nil
}
// AllocateUDPRelayEndpointRequest is a message sent only over DERP to request
// allocation of a relay endpoint on a [tailscale.com/net/udprelay.Server]
type AllocateUDPRelayEndpointRequest struct {
// ClientDisco are the Disco public keys of the clients that should be
// permitted to handshake with the endpoint.
ClientDisco [2]key.DiscoPublic
// Generation represents the allocation request generation. The server must
// echo it back in the [AllocateUDPRelayEndpointResponse] to enable request
// and response alignment client-side.
Generation uint32
}
// allocateUDPRelayEndpointRequestLen is the length of a marshaled
// [AllocateUDPRelayEndpointRequest] message without the message header.
const allocateUDPRelayEndpointRequestLen = key.DiscoPublicRawLen*2 + // ClientDisco
4 // Generation
func (m *AllocateUDPRelayEndpointRequest) AppendMarshal(b []byte) []byte {
ret, p := appendMsgHeader(b, TypeAllocateUDPRelayEndpointRequest, v0, allocateUDPRelayEndpointRequestLen)
for i := 0; i < len(m.ClientDisco); i++ {
disco := m.ClientDisco[i].AppendTo(nil)
copy(p, disco)
p = p[key.DiscoPublicRawLen:]
}
binary.BigEndian.PutUint32(p, m.Generation)
return ret
}
func parseAllocateUDPRelayEndpointRequest(ver uint8, p []byte) (m *AllocateUDPRelayEndpointRequest, err error) {
m = new(AllocateUDPRelayEndpointRequest)
if ver != 0 {
return
}
if len(p) < allocateUDPRelayEndpointRequestLen {
return m, errShort
}
for i := 0; i < len(m.ClientDisco); i++ {
m.ClientDisco[i] = key.DiscoPublicFromRaw32(mem.B(p[:key.DiscoPublicRawLen]))
p = p[key.DiscoPublicRawLen:]
}
m.Generation = binary.BigEndian.Uint32(p)
return m, nil
}
// AllocateUDPRelayEndpointResponse is a message sent only over DERP in response
// to a [AllocateUDPRelayEndpointRequest].
type AllocateUDPRelayEndpointResponse struct {
// Generation represents the allocation request generation. The server must
// echo back the [AllocateUDPRelayEndpointRequest.Generation] here to enable
// request and response alignment client-side.
Generation uint32
UDPRelayEndpoint
}
func (m *AllocateUDPRelayEndpointResponse) AppendMarshal(b []byte) []byte {
endpointsLen := epLength * len(m.AddrPorts)
generationLen := 4
ret, d := appendMsgHeader(b, TypeAllocateUDPRelayEndpointResponse, v0, generationLen+udpRelayEndpointLenMinusAddrPorts+endpointsLen)
binary.BigEndian.PutUint32(d, m.Generation)
m.encode(d[4:])
return ret
}
func parseAllocateUDPRelayEndpointResponse(ver uint8, p []byte) (m *AllocateUDPRelayEndpointResponse, err error) {
m = new(AllocateUDPRelayEndpointResponse)
if ver != 0 {
return m, nil
}
if len(p) < 4 {
return m, errShort
}
m.Generation = binary.BigEndian.Uint32(p)
err = m.decode(p[4:])
return m, err
}
const udpRelayEndpointLenMinusAddrPorts = key.DiscoPublicRawLen + // ServerDisco
(key.DiscoPublicRawLen * 2) + // ClientDisco
8 + // LamportID
4 + // VNI
8 + // BindLifetime
8 // SteadyStateLifetime
// UDPRelayEndpoint is a mirror of [tailscale.com/net/udprelay/endpoint.ServerEndpoint],
// refer to it for field documentation. [UDPRelayEndpoint] is carried in both
// [CallMeMaybeVia] and [AllocateUDPRelayEndpointResponse] messages.
type UDPRelayEndpoint struct {
// ServerDisco is [tailscale.com/net/udprelay/endpoint.ServerEndpoint.ServerDisco]
ServerDisco key.DiscoPublic
// ClientDisco is [tailscale.com/net/udprelay/endpoint.ServerEndpoint.ClientDisco]
ClientDisco [2]key.DiscoPublic
// LamportID is [tailscale.com/net/udprelay/endpoint.ServerEndpoint.LamportID]
LamportID uint64
// VNI is [tailscale.com/net/udprelay/endpoint.ServerEndpoint.VNI]
VNI uint32
// BindLifetime is [tailscale.com/net/udprelay/endpoint.ServerEndpoint.BindLifetime]
BindLifetime time.Duration
// SteadyStateLifetime is [tailscale.com/net/udprelay/endpoint.ServerEndpoint.SteadyStateLifetime]
SteadyStateLifetime time.Duration
// AddrPorts is [tailscale.com/net/udprelay/endpoint.ServerEndpoint.AddrPorts]
AddrPorts []netip.AddrPort
}
// encode encodes m in b. b must be at least [udpRelayEndpointLenMinusAddrPorts]
// + [epLength] * len(m.AddrPorts) bytes long.
func (m *UDPRelayEndpoint) encode(b []byte) {
disco := m.ServerDisco.AppendTo(nil)
copy(b, disco)
b = b[key.DiscoPublicRawLen:]
for i := 0; i < len(m.ClientDisco); i++ {
disco = m.ClientDisco[i].AppendTo(nil)
copy(b, disco)
b = b[key.DiscoPublicRawLen:]
}
binary.BigEndian.PutUint64(b[:8], m.LamportID)
b = b[8:]
binary.BigEndian.PutUint32(b[:4], m.VNI)
b = b[4:]
binary.BigEndian.PutUint64(b[:8], uint64(m.BindLifetime))
b = b[8:]
binary.BigEndian.PutUint64(b[:8], uint64(m.SteadyStateLifetime))
b = b[8:]
for _, ipp := range m.AddrPorts {
a := ipp.Addr().As16()
copy(b, a[:])
binary.BigEndian.PutUint16(b[16:18], ipp.Port())
b = b[epLength:]
}
}
// decode decodes m from b.
func (m *UDPRelayEndpoint) decode(b []byte) error {
if len(b) < udpRelayEndpointLenMinusAddrPorts+epLength ||
(len(b)-udpRelayEndpointLenMinusAddrPorts)%epLength != 0 {
return errShort
}
m.ServerDisco = key.DiscoPublicFromRaw32(mem.B(b[:key.DiscoPublicRawLen]))
b = b[key.DiscoPublicRawLen:]
for i := 0; i < len(m.ClientDisco); i++ {
m.ClientDisco[i] = key.DiscoPublicFromRaw32(mem.B(b[:key.DiscoPublicRawLen]))
b = b[key.DiscoPublicRawLen:]
}
m.LamportID = binary.BigEndian.Uint64(b[:8])
b = b[8:]
m.VNI = binary.BigEndian.Uint32(b[:4])
b = b[4:]
m.BindLifetime = time.Duration(binary.BigEndian.Uint64(b[:8]))
b = b[8:]
m.SteadyStateLifetime = time.Duration(binary.BigEndian.Uint64(b[:8]))
b = b[8:]
m.AddrPorts = make([]netip.AddrPort, 0, len(b)-udpRelayEndpointLenMinusAddrPorts/epLength)
for len(b) > 0 {
var a [16]byte
copy(a[:], b)
m.AddrPorts = append(m.AddrPorts, netip.AddrPortFrom(
netip.AddrFrom16(a).Unmap(),
binary.BigEndian.Uint16(b[16:18])))
b = b[epLength:]
}
return nil
}
// CallMeMaybeVia is a message sent only over DERP to request that the recipient
// try to open up a magicsock path back to the sender. The 'Via' in
// CallMeMaybeVia highlights that candidate paths are served through an
@ -464,78 +627,22 @@ func parseBindUDPRelayEndpointAnswer(ver uint8, p []byte) (m *BindUDPRelayEndpoi
// The recipient may choose to not open a path back if it's already happy with
// its path. Direct connections, e.g. [CallMeMaybe]-signaled, take priority over
// CallMeMaybeVia paths.
//
// This message type is currently considered experimental and is not yet tied to
// a [tailscale.com/tailcfg.CapabilityVersion].
type CallMeMaybeVia struct {
// ServerDisco is [tailscale.com/net/udprelay/endpoint.ServerEndpoint.ServerDisco]
ServerDisco key.DiscoPublic
// LamportID is [tailscale.com/net/udprelay/endpoint.ServerEndpoint.LamportID]
LamportID uint64
// VNI is [tailscale.com/net/udprelay/endpoint.ServerEndpoint.VNI]
VNI uint32
// BindLifetime is [tailscale.com/net/udprelay/endpoint.ServerEndpoint.BindLifetime]
BindLifetime time.Duration
// SteadyStateLifetime is [tailscale.com/net/udprelay/endpoint.ServerEndpoint.SteadyStateLifetime]
SteadyStateLifetime time.Duration
// AddrPorts is [tailscale.com/net/udprelay/endpoint.ServerEndpoint.AddrPorts]
AddrPorts []netip.AddrPort
UDPRelayEndpoint
}
const cmmvDataLenMinusEndpoints = key.DiscoPublicRawLen + // ServerDisco
8 + // LamportID
4 + // VNI
8 + // BindLifetime
8 // SteadyStateLifetime
func (m *CallMeMaybeVia) AppendMarshal(b []byte) []byte {
endpointsLen := epLength * len(m.AddrPorts)
ret, p := appendMsgHeader(b, TypeCallMeMaybeVia, v0, cmmvDataLenMinusEndpoints+endpointsLen)
disco := m.ServerDisco.AppendTo(nil)
copy(p, disco)
p = p[key.DiscoPublicRawLen:]
binary.BigEndian.PutUint64(p[:8], m.LamportID)
p = p[8:]
binary.BigEndian.PutUint32(p[:4], m.VNI)
p = p[4:]
binary.BigEndian.PutUint64(p[:8], uint64(m.BindLifetime))
p = p[8:]
binary.BigEndian.PutUint64(p[:8], uint64(m.SteadyStateLifetime))
p = p[8:]
for _, ipp := range m.AddrPorts {
a := ipp.Addr().As16()
copy(p, a[:])
binary.BigEndian.PutUint16(p[16:18], ipp.Port())
p = p[epLength:]
}
ret, p := appendMsgHeader(b, TypeCallMeMaybeVia, v0, udpRelayEndpointLenMinusAddrPorts+endpointsLen)
m.encode(p)
return ret
}
func parseCallMeMaybeVia(ver uint8, p []byte) (m *CallMeMaybeVia, err error) {
m = new(CallMeMaybeVia)
if len(p) < cmmvDataLenMinusEndpoints+epLength ||
(len(p)-cmmvDataLenMinusEndpoints)%epLength != 0 ||
ver != 0 {
if ver != 0 {
return m, nil
}
m.ServerDisco = key.DiscoPublicFromRaw32(mem.B(p[:key.DiscoPublicRawLen]))
p = p[key.DiscoPublicRawLen:]
m.LamportID = binary.BigEndian.Uint64(p[:8])
p = p[8:]
m.VNI = binary.BigEndian.Uint32(p[:4])
p = p[4:]
m.BindLifetime = time.Duration(binary.BigEndian.Uint64(p[:8]))
p = p[8:]
m.SteadyStateLifetime = time.Duration(binary.BigEndian.Uint64(p[:8]))
p = p[8:]
m.AddrPorts = make([]netip.AddrPort, 0, len(p)-cmmvDataLenMinusEndpoints/epLength)
for len(p) > 0 {
var a [16]byte
copy(a[:], p)
m.AddrPorts = append(m.AddrPorts, netip.AddrPortFrom(
netip.AddrFrom16(a).Unmap(),
binary.BigEndian.Uint16(p[16:18])))
p = p[epLength:]
}
return m, nil
err = m.decode(p)
return m, err
}

41
disco/disco_test.go
View File

@ -25,6 +25,19 @@ func TestMarshalAndParse(t *testing.T) {
},
}
udpRelayEndpoint := UDPRelayEndpoint{
ServerDisco: key.DiscoPublicFromRaw32(mem.B([]byte{1: 1, 2: 2, 30: 30, 31: 31})),
ClientDisco: [2]key.DiscoPublic{key.DiscoPublicFromRaw32(mem.B([]byte{1: 1, 2: 2, 3: 3, 30: 30, 31: 31})), key.DiscoPublicFromRaw32(mem.B([]byte{1: 1, 2: 2, 4: 4, 30: 30, 31: 31}))},
LamportID: 123,
VNI: 456,
BindLifetime: time.Second,
SteadyStateLifetime: time.Minute,
AddrPorts: []netip.AddrPort{
netip.MustParseAddrPort("1.2.3.4:567"),
netip.MustParseAddrPort("[2001::3456]:789"),
},
}
tests := []struct {
name string
want string
@ -117,17 +130,25 @@ func TestMarshalAndParse(t *testing.T) {
{
name: "call_me_maybe_via",
m: &CallMeMaybeVia{
ServerDisco: key.DiscoPublicFromRaw32(mem.B([]byte{1: 1, 2: 2, 30: 30, 31: 31})),
LamportID: 123,
VNI: 456,
BindLifetime: time.Second,
SteadyStateLifetime: time.Minute,
AddrPorts: []netip.AddrPort{
netip.MustParseAddrPort("1.2.3.4:567"),
netip.MustParseAddrPort("[2001::3456]:789"),
},
UDPRelayEndpoint: udpRelayEndpoint,
},
want: "07 00 00 01 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 1e 1f 00 00 00 00 00 00 00 7b 00 00 01 c8 00 00 00 00 3b 9a ca 00 00 00 00 0d f8 47 58 00 00 00 00 00 00 00 00 00 00 00 ff ff 01 02 03 04 02 37 20 01 00 00 00 00 00 00 00 00 00 00 00 00 34 56 03 15",
want: "07 00 00 01 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 1e 1f 00 01 02 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 1e 1f 00 01 02 00 04 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 1e 1f 00 00 00 00 00 00 00 7b 00 00 01 c8 00 00 00 00 3b 9a ca 00 00 00 00 0d f8 47 58 00 00 00 00 00 00 00 00 00 00 00 ff ff 01 02 03 04 02 37 20 01 00 00 00 00 00 00 00 00 00 00 00 00 34 56 03 15",
},
{
name: "allocate_udp_relay_endpoint_request",
m: &AllocateUDPRelayEndpointRequest{
ClientDisco: [2]key.DiscoPublic{key.DiscoPublicFromRaw32(mem.B([]byte{1: 1, 2: 2, 3: 3, 30: 30, 31: 31})), key.DiscoPublicFromRaw32(mem.B([]byte{1: 1, 2: 2, 4: 4, 30: 30, 31: 31}))},
Generation: 1,
},
want: "08 00 00 01 02 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 1e 1f 00 01 02 00 04 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 1e 1f 00 00 00 01",
},
{
name: "allocate_udp_relay_endpoint_response",
m: &AllocateUDPRelayEndpointResponse{
Generation: 1,
UDPRelayEndpoint: udpRelayEndpoint,
},
want: "09 00 00 00 00 01 00 01 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 1e 1f 00 01 02 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 1e 1f 00 01 02 00 04 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 1e 1f 00 00 00 00 00 00 00 7b 00 00 01 c8 00 00 00 00 3b 9a ca 00 00 00 00 0d f8 47 58 00 00 00 00 00 00 00 00 00 00 00 ff ff 01 02 03 04 02 37 20 01 00 00 00 00 00 00 00 00 00 00 00 00 34 56 03 15",
},
}
for _, tt := range tests {

151
feature/relayserver/relayserver.go
View File

@ -6,25 +6,21 @@
package relayserver
import (
"encoding/json"
"errors"
"fmt"
"io"
"net/http"
"sync"
"time"
"tailscale.com/disco"
"tailscale.com/feature"
"tailscale.com/ipn"
"tailscale.com/ipn/ipnext"
"tailscale.com/ipn/ipnlocal"
"tailscale.com/net/udprelay"
"tailscale.com/net/udprelay/endpoint"
"tailscale.com/tailcfg"
"tailscale.com/types/key"
"tailscale.com/types/logger"
"tailscale.com/types/ptr"
"tailscale.com/util/httpm"
"tailscale.com/util/eventbus"
"tailscale.com/wgengine/magicsock"
)
// featureName is the name of the feature implemented by this package.
@ -34,26 +30,34 @@ const featureName = "relayserver"
func init() {
feature.Register(featureName)
ipnext.RegisterExtension(featureName, newExtension)
ipnlocal.RegisterPeerAPIHandler("/v0/relay/endpoint", handlePeerAPIRelayAllocateEndpoint)
}
// newExtension is an [ipnext.NewExtensionFn] that creates a new relay server
// extension. It is registered with [ipnext.RegisterExtension] if the package is
// imported.
func newExtension(logf logger.Logf, _ ipnext.SafeBackend) (ipnext.Extension, error) {
return &extension{logf: logger.WithPrefix(logf, featureName+": ")}, nil
func newExtension(logf logger.Logf, sb ipnext.SafeBackend) (ipnext.Extension, error) {
return &extension{
logf: logger.WithPrefix(logf, featureName+": "),
bus: sb.Sys().Bus.Get(),
}, nil
}
// extension is an [ipnext.Extension] managing the relay server on platforms
// that import this package.
type extension struct {
logf logger.Logf
bus *eventbus.Bus
mu sync.Mutex // guards the following fields
mu sync.Mutex // guards the following fields
eventClient *eventbus.Client // closed to stop consumeEventbusTopics
reqSub *eventbus.Subscriber[magicsock.UDPRelayAllocReq] // receives endpoint alloc requests from magicsock
respPub *eventbus.Publisher[magicsock.UDPRelayAllocResp] // publishes endpoint alloc responses to magicsock
shutdown bool
port *int // ipn.Prefs.RelayServerPort, nil if disabled
hasNodeAttrDisableRelayServer bool // tailcfg.NodeAttrDisableRelayServer
server relayServer // lazily initialized
port *int // ipn.Prefs.RelayServerPort, nil if disabled
busDoneCh chan struct{} // non-nil if port is non-nil, closed when consumeEventbusTopics returns
hasNodeAttrDisableRelayServer bool // tailcfg.NodeAttrDisableRelayServer
server relayServer // lazily initialized
}
// relayServer is the interface of [udprelay.Server].
@ -77,6 +81,18 @@ func (e *extension) Init(host ipnext.Host) error {
return nil
}
// initBusConnection initializes the [*eventbus.Client], [*eventbus.Subscriber],
// [*eventbus.Publisher], and [chan struct{}] used to publish/receive endpoint
// allocation messages to/from the [*eventbus.Bus]. It also starts
// consumeEventbusTopics in a separate goroutine.
func (e *extension) initBusConnection() {
e.eventClient = e.bus.Client("relayserver.extension")
e.reqSub = eventbus.Subscribe[magicsock.UDPRelayAllocReq](e.eventClient)
e.respPub = eventbus.Publish[magicsock.UDPRelayAllocResp](e.eventClient)
e.busDoneCh = make(chan struct{})
go e.consumeEventbusTopics()
}
func (e *extension) selfNodeViewChanged(nodeView tailcfg.NodeView) {
e.mu.Lock()
defer e.mu.Unlock()
@ -98,13 +114,59 @@ func (e *extension) profileStateChanged(_ ipn.LoginProfileView, prefs ipn.PrefsV
e.server.Close()
e.server = nil
}
if e.port != nil {
e.eventClient.Close()
<-e.busDoneCh
}
e.port = nil
if ok {
e.port = ptr.To(newPort)
e.initBusConnection()
}
}
}
func (e *extension) consumeEventbusTopics() {
defer close(e.busDoneCh)
for {
select {
case <-e.reqSub.Done():
// If reqSub is done, the eventClient has been closed, which is a
// signal to return.
return
case req := <-e.reqSub.Events():
rs, err := e.relayServerOrInit()
if err != nil {
e.logf("error initializing server: %v", err)
continue
}
se, err := rs.AllocateEndpoint(req.Message.ClientDisco[0], req.Message.ClientDisco[1])
if err != nil {
e.logf("error allocating endpoint: %v", err)
continue
}
e.respPub.Publish(magicsock.UDPRelayAllocResp{
ReqRxFromNodeKey: req.RxFromNodeKey,
ReqRxFromDiscoKey: req.RxFromDiscoKey,
Message: &disco.AllocateUDPRelayEndpointResponse{
Generation: req.Message.Generation,
UDPRelayEndpoint: disco.UDPRelayEndpoint{
ServerDisco: se.ServerDisco,
ClientDisco: se.ClientDisco,
LamportID: se.LamportID,
VNI: se.VNI,
BindLifetime: se.BindLifetime.Duration,
SteadyStateLifetime: se.SteadyStateLifetime.Duration,
AddrPorts: se.AddrPorts,
},
},
})
}
}
}
// Shutdown implements [ipnlocal.Extension].
func (e *extension) Shutdown() error {
e.mu.Lock()
@ -114,6 +176,10 @@ func (e *extension) Shutdown() error {
e.server.Close()
e.server = nil
}
if e.port != nil {
e.eventClient.Close()
<-e.busDoneCh
}
return nil
}
@ -139,60 +205,3 @@ func (e *extension) relayServerOrInit() (relayServer, error) {
}
return e.server, nil
}
func handlePeerAPIRelayAllocateEndpoint(h ipnlocal.PeerAPIHandler, w http.ResponseWriter, r *http.Request) {
e, ok := ipnlocal.GetExt[*extension](h.LocalBackend())
if !ok {
http.Error(w, "relay failed to initialize", http.StatusServiceUnavailable)
return
}
httpErrAndLog := func(message string, code int) {
http.Error(w, message, code)
h.Logf("relayserver: request from %v returned code %d: %s", h.RemoteAddr(), code, message)
}
if !h.PeerCaps().HasCapability(tailcfg.PeerCapabilityRelay) {
httpErrAndLog("relay not permitted", http.StatusForbidden)
return
}
if r.Method != httpm.POST {
httpErrAndLog("only POST method is allowed", http.StatusMethodNotAllowed)
return
}
var allocateEndpointReq struct {
DiscoKeys []key.DiscoPublic
}
err := json.NewDecoder(io.LimitReader(r.Body, 512)).Decode(&allocateEndpointReq)
if err != nil {
httpErrAndLog(err.Error(), http.StatusBadRequest)
return
}
if len(allocateEndpointReq.DiscoKeys) != 2 {
httpErrAndLog("2 disco public keys must be supplied", http.StatusBadRequest)
return
}
rs, err := e.relayServerOrInit()
if err != nil {
httpErrAndLog(err.Error(), http.StatusServiceUnavailable)
return
}
ep, err := rs.AllocateEndpoint(allocateEndpointReq.DiscoKeys[0], allocateEndpointReq.DiscoKeys[1])
if err != nil {
var notReady udprelay.ErrServerNotReady
if errors.As(err, &notReady) {
w.Header().Set("Retry-After", fmt.Sprintf("%d", notReady.RetryAfter.Round(time.Second)/time.Second))
httpErrAndLog(err.Error(), http.StatusServiceUnavailable)
return
}
httpErrAndLog(err.Error(), http.StatusInternalServerError)
return
}
err = json.NewEncoder(w).Encode(&ep)
if err != nil {
httpErrAndLog(err.Error(), http.StatusInternalServerError)
}
}

10
feature/relayserver/relayserver_test.go
View File

@ -9,6 +9,7 @@ import (
"tailscale.com/ipn"
"tailscale.com/net/udprelay/endpoint"
"tailscale.com/tsd"
"tailscale.com/types/key"
"tailscale.com/types/ptr"
)
@ -108,9 +109,18 @@ func Test_extension_profileStateChanged(t *testing.T) {
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
sys := tsd.NewSystem()
bus := sys.Bus.Get()
e := &extension{
port: tt.fields.port,
server: tt.fields.server,
bus: bus,
}
if e.port != nil {
// Entering profileStateChanged with a non-nil port requires
// bus init, which is called in profileStateChanged when
// transitioning port from nil to non-nil.
e.initBusConnection()
}
e.profileStateChanged(ipn.LoginProfileView{}, tt.args.prefs, tt.args.sameNode)
if tt.wantNilServer != (e.server == nil) {

2
ipn/ipnlocal/local.go
View File

@ -6957,7 +6957,7 @@ func (b *LocalBackend) DebugReSTUN() error {
return nil
}
func (b *LocalBackend) DebugPeerRelayServers() set.Set[netip.AddrPort] {
func (b *LocalBackend) DebugPeerRelayServers() set.Set[netip.Addr] {
return b.MagicConn().PeerRelays()
}

2
ipn/localapi/localapi.go
View File

@ -699,7 +699,7 @@ func (h *Handler) serveDebug(w http.ResponseWriter, r *http.Request) {
h.b.DebugForcePreferDERP(n)
case "peer-relay-servers":
servers := h.b.DebugPeerRelayServers().Slice()
slices.SortFunc(servers, func(a, b netip.AddrPort) int {
slices.SortFunc(servers, func(a, b netip.Addr) int {
return a.Compare(b)
})
err = json.NewEncoder(w).Encode(servers)

9
net/udprelay/endpoint/endpoint.go
View File

@ -7,11 +7,16 @@ package endpoint
import (
"net/netip"
"time"
"tailscale.com/tstime"
"tailscale.com/types/key"
)
// ServerRetryAfter is the default
// [tailscale.com/net/udprelay.ErrServerNotReady.RetryAfter] value.
const ServerRetryAfter = time.Second * 3
// ServerEndpoint contains details for an endpoint served by a
// [tailscale.com/net/udprelay.Server].
type ServerEndpoint struct {
@ -21,6 +26,10 @@ type ServerEndpoint struct {
// unique ServerEndpoint allocation.
ServerDisco key.DiscoPublic
// ClientDisco are the Disco public keys of the relay participants permitted
// to handshake with this endpoint.
ClientDisco [2]key.DiscoPublic
// LamportID is unique and monotonically non-decreasing across
// ServerEndpoint allocations for the lifetime of Server. It enables clients
// to dedup and resolve allocation event order. Clients may race to allocate

45
net/udprelay/server.go
View File

@ -73,23 +73,7 @@ type Server struct {
lamportID uint64
vniPool []uint32 // the pool of available VNIs
byVNI map[uint32]*serverEndpoint
byDisco map[pairOfDiscoPubKeys]*serverEndpoint
}
// pairOfDiscoPubKeys is a pair of key.DiscoPublic. It must be constructed via
// newPairOfDiscoPubKeys to ensure lexicographical ordering.
type pairOfDiscoPubKeys [2]key.DiscoPublic
func (p pairOfDiscoPubKeys) String() string {
return fmt.Sprintf("%s <=> %s", p[0].ShortString(), p[1].ShortString())
}
func newPairOfDiscoPubKeys(discoA, discoB key.DiscoPublic) pairOfDiscoPubKeys {
pair := pairOfDiscoPubKeys([2]key.DiscoPublic{discoA, discoB})
slices.SortFunc(pair[:], func(a, b key.DiscoPublic) int {
return a.Compare(b)
})
return pair
byDisco map[key.SortedPairOfDiscoPublic]*serverEndpoint
}
// serverEndpoint contains Server-internal [endpoint.ServerEndpoint] state.
@ -99,7 +83,7 @@ type serverEndpoint struct {
// indexing of this array aligns with the following fields, e.g.
// discoSharedSecrets[0] is the shared secret to use when sealing
// Disco protocol messages for transmission towards discoPubKeys[0].
discoPubKeys pairOfDiscoPubKeys
discoPubKeys key.SortedPairOfDiscoPublic
discoSharedSecrets [2]key.DiscoShared
handshakeGeneration [2]uint32 // or zero if a handshake has never started for that relay leg
handshakeAddrPorts [2]netip.AddrPort // or zero value if a handshake has never started for that relay leg
@ -126,7 +110,7 @@ func (e *serverEndpoint) handleDiscoControlMsg(from netip.AddrPort, senderIndex
if common.VNI != e.vni {
return errors.New("mismatching VNI")
}
if common.RemoteKey.Compare(e.discoPubKeys[otherSender]) != 0 {
if common.RemoteKey.Compare(e.discoPubKeys.Get()[otherSender]) != 0 {
return errors.New("mismatching RemoteKey")
}
return nil
@ -152,7 +136,7 @@ func (e *serverEndpoint) handleDiscoControlMsg(from netip.AddrPort, senderIndex
m := new(disco.BindUDPRelayEndpointChallenge)
m.VNI = e.vni
m.Generation = discoMsg.Generation
m.RemoteKey = e.discoPubKeys[otherSender]
m.RemoteKey = e.discoPubKeys.Get()[otherSender]
rand.Read(e.challenge[senderIndex][:])
copy(m.Challenge[:], e.challenge[senderIndex][:])
reply := make([]byte, packet.GeneveFixedHeaderLength, 512)
@ -200,9 +184,9 @@ func (e *serverEndpoint) handleSealedDiscoControlMsg(from netip.AddrPort, b []by
sender := key.DiscoPublicFromRaw32(mem.B(senderRaw))
senderIndex := -1
switch {
case sender.Compare(e.discoPubKeys[0]) == 0:
case sender.Compare(e.discoPubKeys.Get()[0]) == 0:
senderIndex = 0
case sender.Compare(e.discoPubKeys[1]) == 0:
case sender.Compare(e.discoPubKeys.Get()[1]) == 0:
senderIndex = 1
default:
// unknown Disco public key
@ -291,12 +275,12 @@ func (e *serverEndpoint) isBound() bool {
// which is useful to override in tests.
func NewServer(logf logger.Logf, port int, overrideAddrs []netip.Addr) (s *Server, err error) {
s = &Server{
logf: logger.WithPrefix(logf, "relayserver"),
logf: logf,
disco: key.NewDisco(),
bindLifetime: defaultBindLifetime,
steadyStateLifetime: defaultSteadyStateLifetime,
closeCh: make(chan struct{}),
byDisco: make(map[pairOfDiscoPubKeys]*serverEndpoint),
byDisco: make(map[key.SortedPairOfDiscoPublic]*serverEndpoint),
byVNI: make(map[uint32]*serverEndpoint),
}
s.discoPublic = s.disco.Public()
@ -315,7 +299,7 @@ func NewServer(logf logger.Logf, port int, overrideAddrs []netip.Addr) (s *Serve
}
s.netChecker = &netcheck.Client{
NetMon: netMon,
Logf: logger.WithPrefix(logf, "relayserver: netcheck:"),
Logf: logger.WithPrefix(logf, "netcheck: "),
SendPacket: func(b []byte, addrPort netip.AddrPort) (int, error) {
if addrPort.Addr().Is4() {
return s.uc4.WriteToUDPAddrPort(b, addrPort)
@ -615,7 +599,7 @@ func (s *Server) AllocateEndpoint(discoA, discoB key.DiscoPublic) (endpoint.Serv
if len(s.addrPorts) == 0 {
if !s.addrDiscoveryOnce {
return endpoint.ServerEndpoint{}, ErrServerNotReady{RetryAfter: 3 * time.Second}
return endpoint.ServerEndpoint{}, ErrServerNotReady{RetryAfter: endpoint.ServerRetryAfter}
}
return endpoint.ServerEndpoint{}, errors.New("server addrPorts are not yet known")
}
@ -624,7 +608,7 @@ func (s *Server) AllocateEndpoint(discoA, discoB key.DiscoPublic) (endpoint.Serv
return endpoint.ServerEndpoint{}, fmt.Errorf("client disco equals server disco: %s", s.discoPublic.ShortString())
}
pair := newPairOfDiscoPubKeys(discoA, discoB)
pair := key.NewSortedPairOfDiscoPublic(discoA, discoB)
e, ok := s.byDisco[pair]
if ok {
// Return the existing allocation. Clients can resolve duplicate
@ -639,6 +623,7 @@ func (s *Server) AllocateEndpoint(discoA, discoB key.DiscoPublic) (endpoint.Serv
// behaviors and endpoint state (bound or not). We might want to
// consider storing them (maybe interning) in the [*serverEndpoint]
// at allocation time.
ClientDisco: pair.Get(),
AddrPorts: slices.Clone(s.addrPorts),
VNI: e.vni,
LamportID: e.lamportID,
@ -657,15 +642,17 @@ func (s *Server) AllocateEndpoint(discoA, discoB key.DiscoPublic) (endpoint.Serv
lamportID: s.lamportID,
allocatedAt: time.Now(),
}
e.discoSharedSecrets[0] = s.disco.Shared(e.discoPubKeys[0])
e.discoSharedSecrets[1] = s.disco.Shared(e.discoPubKeys[1])
e.discoSharedSecrets[0] = s.disco.Shared(e.discoPubKeys.Get()[0])
e.discoSharedSecrets[1] = s.disco.Shared(e.discoPubKeys.Get()[1])
e.vni, s.vniPool = s.vniPool[0], s.vniPool[1:]
s.byDisco[pair] = e
s.byVNI[e.vni] = e
s.logf("allocated endpoint vni=%d lamportID=%d disco[0]=%v disco[1]=%v", e.vni, e.lamportID, pair.Get()[0].ShortString(), pair.Get()[1].ShortString())
return endpoint.ServerEndpoint{
ServerDisco: s.discoPublic,
ClientDisco: pair.Get(),
AddrPorts: slices.Clone(s.addrPorts),
VNI: e.vni,
LamportID: e.lamportID,

3
tailcfg/tailcfg.go
View File

@ -165,7 +165,8 @@ type CapabilityVersion int
// - 118: 2025-07-01: Client sends Hostinfo.StateEncrypted to report whether the state file is encrypted at rest (#15830)
// - 119: 2025-07-10: Client uses Hostinfo.Location.Priority to prioritize one route over another.
// - 120: 2025-07-15: Client understands peer relay disco messages, and implements peer client and relay server functions
const CurrentCapabilityVersion CapabilityVersion = 120
// - 121: 2025-07-19: Client understands peer relay endpoint alloc with [disco.AllocateUDPRelayEndpointRequest] & [disco.AllocateUDPRelayEndpointResponse]
const CurrentCapabilityVersion CapabilityVersion = 121
// ID is an integer ID for a user, node, or login allocated by the
// control plane.

38
types/key/disco.go
View File

@ -73,6 +73,44 @@ func (k DiscoPrivate) Shared(p DiscoPublic) DiscoShared {
return ret
}
// SortedPairOfDiscoPublic is a lexicographically sorted container of two
// [DiscoPublic] keys.
type SortedPairOfDiscoPublic struct {
k [2]DiscoPublic
}
// Get returns the underlying keys.
func (s SortedPairOfDiscoPublic) Get() [2]DiscoPublic {
return s.k
}
// NewSortedPairOfDiscoPublic returns a SortedPairOfDiscoPublic from a and b.
func NewSortedPairOfDiscoPublic(a, b DiscoPublic) SortedPairOfDiscoPublic {
s := SortedPairOfDiscoPublic{}
if a.Compare(b) < 0 {
s.k[0] = a
s.k[1] = b
} else {
s.k[0] = b
s.k[1] = a
}
return s
}
func (s SortedPairOfDiscoPublic) String() string {
return fmt.Sprintf("%s <=> %s", s.k[0].ShortString(), s.k[1].ShortString())
}
// Equal returns true if s and b are equal, otherwise it returns false.
func (s SortedPairOfDiscoPublic) Equal(b SortedPairOfDiscoPublic) bool {
for i := range s.k {
if s.k[i].Compare(b.k[i]) != 0 {
return false
}
}
return true
}
// DiscoPublic is the public portion of a DiscoPrivate.
type DiscoPublic struct {
k [32]byte

18
types/key/disco_test.go
View File

@ -81,3 +81,21 @@ func TestDiscoShared(t *testing.T) {
t.Error("k1.Shared(k2) != k2.Shared(k1)")
}
}
func TestSortedPairOfDiscoPublic(t *testing.T) {
pubA := DiscoPublic{}
pubA.k[0] = 0x01
pubB := DiscoPublic{}
pubB.k[0] = 0x02
sortedInput := NewSortedPairOfDiscoPublic(pubA, pubB)
unsortedInput := NewSortedPairOfDiscoPublic(pubB, pubA)
if sortedInput.Get() != unsortedInput.Get() {
t.Fatal("sortedInput.Get() != unsortedInput.Get()")
}
if unsortedInput.Get()[0] != pubA {
t.Fatal("unsortedInput.Get()[0] != pubA")
}
if unsortedInput.Get()[1] != pubB {
t.Fatal("unsortedInput.Get()[1] != pubB")
}
}

17
wgengine/magicsock/endpoint.go
View File

@ -879,8 +879,14 @@ func (de *endpoint) setHeartbeatDisabled(v bool) {
// discoverUDPRelayPathsLocked starts UDP relay path discovery.
func (de *endpoint) discoverUDPRelayPathsLocked(now mono.Time) {
// TODO(jwhited): return early if there are no relay servers set, otherwise
// we spin up and down relayManager.runLoop unnecessarily.
if !de.c.hasPeerRelayServers.Load() {
// Changes in this value between its access and the logic following
// are fine, we will eventually do the "right" thing during future path
// discovery. The worst case is we suppress path discovery for the
// current cycle, or we unnecessarily call into [relayManager] and do
// some wasted work.
return
}
de.lastUDPRelayPathDiscovery = now
lastBest := de.bestAddr
lastBestIsTrusted := mono.Now().Before(de.trustBestAddrUntil)
@ -2035,8 +2041,15 @@ func (de *endpoint) numStopAndReset() int64 {
return atomic.LoadInt64(&de.numStopAndResetAtomic)
}
// setDERPHome sets the provided regionID as home for de. Calls to setDERPHome
// must never run concurrent to [Conn.updateRelayServersSet], otherwise
// [candidatePeerRelay] DERP home changes may be missed from the perspective of
// [relayManager].
func (de *endpoint) setDERPHome(regionID uint16) {
de.mu.Lock()
defer de.mu.Unlock()
de.derpAddr = netip.AddrPortFrom(tailcfg.DerpMagicIPAddr, uint16(regionID))
if de.c.hasPeerRelayServers.Load() {
de.c.relayManager.handleDERPHomeChange(de.publicKey, regionID)
}
}

367
wgengine/magicsock/magicsock.go
View File

@ -175,13 +175,15 @@ type Conn struct {
// These [eventbus.Subscriber] fields are solely accessed by
// consumeEventbusTopics once initialized.
pmSub *eventbus.Subscriber[portmapper.Mapping]
filterSub *eventbus.Subscriber[FilterUpdate]
nodeViewsSub *eventbus.Subscriber[NodeViewsUpdate]
nodeMutsSub *eventbus.Subscriber[NodeMutationsUpdate]
syncSub *eventbus.Subscriber[syncPoint]
syncPub *eventbus.Publisher[syncPoint]
subsDoneCh chan struct{} // closed when consumeEventbusTopics returns
pmSub *eventbus.Subscriber[portmapper.Mapping]
filterSub *eventbus.Subscriber[FilterUpdate]
nodeViewsSub *eventbus.Subscriber[NodeViewsUpdate]
nodeMutsSub *eventbus.Subscriber[NodeMutationsUpdate]
syncSub *eventbus.Subscriber[syncPoint]
syncPub *eventbus.Publisher[syncPoint]
allocRelayEndpointPub *eventbus.Publisher[UDPRelayAllocReq]
allocRelayEndpointSub *eventbus.Subscriber[UDPRelayAllocResp]
subsDoneCh chan struct{} // closed when consumeEventbusTopics returns
// pconn4 and pconn6 are the underlying UDP sockets used to
// send/receive packets for wireguard and other magicsock
@ -271,6 +273,14 @@ type Conn struct {
// captureHook, if non-nil, is the pcap logging callback when capturing.
captureHook syncs.AtomicValue[packet.CaptureCallback]
// hasPeerRelayServers is whether [relayManager] is configured with at least
// one peer relay server via [relayManager.handleRelayServersSet]. It is
// only accessed by [Conn.updateRelayServersSet], [endpoint.setDERPHome],
// and [endpoint.discoverUDPRelayPathsLocked]. It exists to suppress
// calls into [relayManager] leading to wasted work involving channel
// operations and goroutine creation.
hasPeerRelayServers atomic.Bool
// discoPrivate is the private naclbox key used for active
// discovery traffic. It is always present, and immutable.
discoPrivate key.DiscoPrivate
@ -567,6 +577,36 @@ func (s syncPoint) Signal() {
close(s)
}
// UDPRelayAllocReq represents a [*disco.AllocateUDPRelayEndpointRequest]
// reception event. This is signaled over an [eventbus.Bus] from
// [magicsock.Conn] towards [relayserver.extension].
type UDPRelayAllocReq struct {
// RxFromNodeKey is the unauthenticated (DERP server claimed src) node key
// of the transmitting party, noted at disco message reception time over
// DERP. This node key is unambiguously-aligned with RxFromDiscoKey being
// that the disco message is received over DERP.
RxFromNodeKey key.NodePublic
// RxFromDiscoKey is the disco key of the transmitting party, noted and
// authenticated at reception time.
RxFromDiscoKey key.DiscoPublic
// Message is the disco message.
Message *disco.AllocateUDPRelayEndpointRequest
}
// UDPRelayAllocResp represents a [*disco.AllocateUDPRelayEndpointResponse]
// that is yet to be transmitted over DERP (or delivered locally if
// ReqRxFromNodeKey is self). This is signaled over an [eventbus.Bus] from
// [relayserver.extension] towards [magicsock.Conn].
type UDPRelayAllocResp struct {
// ReqRxFromNodeKey is copied from [UDPRelayAllocReq.RxFromNodeKey]. It
// enables peer lookup leading up to transmission over DERP.
ReqRxFromNodeKey key.NodePublic
// ReqRxFromDiscoKey is copied from [UDPRelayAllocReq.RxFromDiscoKey].
ReqRxFromDiscoKey key.DiscoPublic
// Message is the disco message.
Message *disco.AllocateUDPRelayEndpointResponse
}
// newConn is the error-free, network-listening-side-effect-free based
// of NewConn. Mostly for tests.
func newConn(logf logger.Logf) *Conn {
@ -625,10 +665,40 @@ func (c *Conn) consumeEventbusTopics() {
case syncPoint := <-c.syncSub.Events():
c.dlogf("magicsock: received sync point after reconfig")
syncPoint.Signal()
case allocResp := <-c.allocRelayEndpointSub.Events():
c.onUDPRelayAllocResp(allocResp)
}
}
}
func (c *Conn) onUDPRelayAllocResp(allocResp UDPRelayAllocResp) {
c.mu.Lock()
defer c.mu.Unlock()
ep, ok := c.peerMap.endpointForNodeKey(allocResp.ReqRxFromNodeKey)
if !ok {
// If it's not a peer, it might be for self (we can peer relay through
// ourselves), in which case we want to hand it down to [relayManager]
// now versus taking a network round-trip through DERP.
selfNodeKey := c.publicKeyAtomic.Load()
if selfNodeKey.Compare(allocResp.ReqRxFromNodeKey) == 0 &&
allocResp.ReqRxFromDiscoKey.Compare(c.discoPublic) == 0 {
c.relayManager.handleRxDiscoMsg(c, allocResp.Message, selfNodeKey, allocResp.ReqRxFromDiscoKey, epAddr{})
}
return
}
disco := ep.disco.Load()
if disco == nil {
return
}
if disco.key.Compare(allocResp.ReqRxFromDiscoKey) != 0 {
return
}
ep.mu.Lock()
defer ep.mu.Unlock()
derpAddr := ep.derpAddr
go c.sendDiscoMessage(epAddr{ap: derpAddr}, ep.publicKey, disco.key, allocResp.Message, discoVerboseLog)
}
// Synchronize waits for all [eventbus] events published
// prior to this call to be processed by the receiver.
func (c *Conn) Synchronize() {
@ -670,6 +740,8 @@ func NewConn(opts Options) (*Conn, error) {
c.nodeMutsSub = eventbus.Subscribe[NodeMutationsUpdate](c.eventClient)
c.syncSub = eventbus.Subscribe[syncPoint](c.eventClient)
c.syncPub = eventbus.Publish[syncPoint](c.eventClient)
c.allocRelayEndpointPub = eventbus.Publish[UDPRelayAllocReq](c.eventClient)
c.allocRelayEndpointSub = eventbus.Subscribe[UDPRelayAllocResp](c.eventClient)
c.subsDoneCh = make(chan struct{})
go c.consumeEventbusTopics()
}
@ -1847,6 +1919,24 @@ func (v *virtualNetworkID) get() uint32 {
return v._vni & vniGetMask
}
// sendDiscoAllocateUDPRelayEndpointRequest is primarily an alias for
// sendDiscoMessage, but it will alternatively send m over the eventbus if dst
// is a DERP IP:port, and dstKey is self. This saves a round-trip through DERP
// when we are attempting to allocate on a self (in-process) peer relay server.
func (c *Conn) sendDiscoAllocateUDPRelayEndpointRequest(dst epAddr, dstKey key.NodePublic, dstDisco key.DiscoPublic, allocReq *disco.AllocateUDPRelayEndpointRequest, logLevel discoLogLevel) (sent bool, err error) {
isDERP := dst.ap.Addr() == tailcfg.DerpMagicIPAddr
selfNodeKey := c.publicKeyAtomic.Load()
if isDERP && dstKey.Compare(selfNodeKey) == 0 {
c.allocRelayEndpointPub.Publish(UDPRelayAllocReq{
RxFromNodeKey: selfNodeKey,
RxFromDiscoKey: c.discoPublic,
Message: allocReq,
})
return true, nil
}
return c.sendDiscoMessage(dst, dstKey, dstDisco, allocReq, logLevel)
}
// sendDiscoMessage sends discovery message m to dstDisco at dst.
//
// If dst.ap is a DERP IP:port, then dstKey must be non-zero.
@ -2176,7 +2266,7 @@ func (c *Conn) handleDiscoMessage(msg []byte, src epAddr, shouldBeRelayHandshake
c.logf("[unexpected] %T packets should not come from a relay server with Geneve control bit set", dm)
return
}
c.relayManager.handleGeneveEncapDiscoMsg(c, challenge, di, src)
c.relayManager.handleRxDiscoMsg(c, challenge, key.NodePublic{}, di.discoKey, src)
return
}
@ -2201,7 +2291,7 @@ func (c *Conn) handleDiscoMessage(msg []byte, src epAddr, shouldBeRelayHandshake
// If it's an unknown TxID, and it's Geneve-encapsulated, then
// make [relayManager] aware. It might be in the middle of probing
// src.
c.relayManager.handleGeneveEncapDiscoMsg(c, dm, di, src)
c.relayManager.handleRxDiscoMsg(c, dm, key.NodePublic{}, di.discoKey, src)
}
case *disco.CallMeMaybe, *disco.CallMeMaybeVia:
var via *disco.CallMeMaybeVia
@ -2276,7 +2366,95 @@ func (c *Conn) handleDiscoMessage(msg []byte, src epAddr, shouldBeRelayHandshake
len(cmm.MyNumber))
go ep.handleCallMeMaybe(cmm)
}
case *disco.AllocateUDPRelayEndpointRequest, *disco.AllocateUDPRelayEndpointResponse:
var resp *disco.AllocateUDPRelayEndpointResponse
isResp := false
msgType := "AllocateUDPRelayEndpointRequest"
req, ok := dm.(*disco.AllocateUDPRelayEndpointRequest)
if ok {
metricRecvDiscoAllocUDPRelayEndpointRequest.Add(1)
} else {
metricRecvDiscoAllocUDPRelayEndpointResponse.Add(1)
resp = dm.(*disco.AllocateUDPRelayEndpointResponse)
msgType = "AllocateUDPRelayEndpointResponse"
isResp = true
}
if !isDERP {
// These messages should only come via DERP.
c.logf("[unexpected] %s packets should only come via DERP", msgType)
return
}
nodeKey := derpNodeSrc
ep, ok := c.peerMap.endpointForNodeKey(nodeKey)
if !ok {
c.logf("magicsock: disco: ignoring %s from %v; %v is unknown", msgType, sender.ShortString(), derpNodeSrc.ShortString())
return
}
epDisco := ep.disco.Load()
if epDisco == nil {
return
}
if epDisco.key != di.discoKey {
if isResp {
metricRecvDiscoAllocUDPRelayEndpointResponseBadDisco.Add(1)
} else {
metricRecvDiscoAllocUDPRelayEndpointRequestBadDisco.Add(1)
}
c.logf("[unexpected] %s from peer via DERP whose netmap discokey != disco source", msgType)
return
}
if isResp {
c.dlogf("[v1] magicsock: disco: %v<-%v (%v, %v) got %s, %d endpoints",
c.discoShort, epDisco.short,
ep.publicKey.ShortString(), derpStr(src.String()),
msgType,
len(resp.AddrPorts))
c.relayManager.handleRxDiscoMsg(c, resp, nodeKey, di.discoKey, src)
return
} else if sender.Compare(req.ClientDisco[0]) != 0 && sender.Compare(req.ClientDisco[1]) != 0 {
// An allocation request must contain the sender's disco key in
// ClientDisco. One of the relay participants must be the sender.
c.logf("magicsock: disco: %s from %v; %v does not contain sender's disco key",
msgType, sender.ShortString(), derpNodeSrc.ShortString())
return
} else {
c.dlogf("[v1] magicsock: disco: %v<-%v (%v, %v) got %s, for %d<->%d",
c.discoShort, epDisco.short,
ep.publicKey.ShortString(), derpStr(src.String()),
msgType,
req.ClientDisco[0], req.ClientDisco[1])
}
if c.filt == nil {
return
}
// Binary search of peers is O(log n) while c.mu is held.
// TODO: We might be able to use ep.nodeAddr instead of all addresses,
// or we might be able to release c.mu before doing this work. Keep it
// simple and slow for now. c.peers.AsSlice is a copy. We may need to
// write our own binary search for a [views.Slice].
peerI, ok := slices.BinarySearchFunc(c.peers.AsSlice(), ep.nodeID, func(peer tailcfg.NodeView, target tailcfg.NodeID) int {
if peer.ID() < target {
return -1
} else if peer.ID() > target {
return 1
}
return 0
})
if !ok {
// unexpected
return
}
if !nodeHasCap(c.filt, c.peers.At(peerI), c.self, tailcfg.PeerCapabilityRelay) {
return
}
c.allocRelayEndpointPub.Publish(UDPRelayAllocReq{
RxFromDiscoKey: sender,
RxFromNodeKey: nodeKey,
Message: req,
})
}
return
}
@ -2337,7 +2515,7 @@ func (c *Conn) handlePingLocked(dm *disco.Ping, src epAddr, di *discoInfo, derpN
// Geneve-encapsulated [disco.Ping] messages in the interest of
// simplicity. It might be in the middle of probing src, so it must be
// made aware.
c.relayManager.handleGeneveEncapDiscoMsg(c, dm, di, src)
c.relayManager.handleRxDiscoMsg(c, dm, key.NodePublic{}, di.discoKey, src)
return
}
@ -2687,7 +2865,7 @@ func (c *Conn) SetProbeUDPLifetime(v bool) {
// capVerIsRelayCapable returns true if version is relay client and server
// capable, otherwise it returns false.
func capVerIsRelayCapable(version tailcfg.CapabilityVersion) bool {
return version >= 120
return version >= 121
}
// onFilterUpdate is called when a [FilterUpdate] is received over the
@ -2715,6 +2893,11 @@ func (c *Conn) onFilterUpdate(f FilterUpdate) {
// peers are passed as args (vs c.mu-guarded fields) to enable callers to
// release c.mu before calling as this is O(m * n) (we iterate all cap rules 'm'
// in filt for every peer 'n').
//
// Calls to updateRelayServersSet must never run concurrent to
// [endpoint.setDERPHome], otherwise [candidatePeerRelay] DERP home changes may
// be missed from the perspective of [relayManager].
//
// TODO: Optimize this so that it's not O(m * n). This might involve:
// 1. Changes to [filter.Filter], e.g. adding a CapsWithValues() to check for
// a given capability instead of building and returning a map of all of
@ -2722,69 +2905,75 @@ func (c *Conn) onFilterUpdate(f FilterUpdate) {
// 2. Moving this work upstream into [nodeBackend] or similar, and publishing
// the computed result over the eventbus instead.
func (c *Conn) updateRelayServersSet(filt *filter.Filter, self tailcfg.NodeView, peers views.Slice[tailcfg.NodeView]) {
relayServers := make(set.Set[netip.AddrPort])
relayServers := make(set.Set[candidatePeerRelay])
nodes := append(peers.AsSlice(), self)
for _, maybeCandidate := range nodes {
peerAPI := peerAPIIfCandidateRelayServer(filt, self, maybeCandidate)
if peerAPI.IsValid() {
relayServers.Add(peerAPI)
}
}
c.relayManager.handleRelayServersSet(relayServers)
}
// peerAPIIfCandidateRelayServer returns the peer API address of maybeCandidate
// if it is considered to be a candidate relay server upon evaluation against
// filt and self, otherwise it returns a zero value. self and maybeCandidate
// may be equal.
func peerAPIIfCandidateRelayServer(filt *filter.Filter, self, maybeCandidate tailcfg.NodeView) netip.AddrPort {
if filt == nil ||
!self.Valid() ||
!maybeCandidate.Valid() ||
!maybeCandidate.Hostinfo().Valid() {
return netip.AddrPort{}
}
if maybeCandidate.ID() != self.ID() && !capVerIsRelayCapable(maybeCandidate.Cap()) {
// If maybeCandidate's [tailcfg.CapabilityVersion] is not relay-capable,
// we skip it. If maybeCandidate happens to be self, then this check is
// unnecessary as self is always capable from this point (the statically
// compiled [tailcfg.CurrentCapabilityVersion]) forward.
return netip.AddrPort{}
}
for _, maybeCandidatePrefix := range maybeCandidate.Addresses().All() {
if !maybeCandidatePrefix.IsSingleIP() {
if maybeCandidate.ID() != self.ID() && !capVerIsRelayCapable(maybeCandidate.Cap()) {
// If maybeCandidate's [tailcfg.CapabilityVersion] is not relay-capable,
// we skip it. If maybeCandidate happens to be self, then this check is
// unnecessary as self is always capable from this point (the statically
// compiled [tailcfg.CurrentCapabilityVersion]) forward.
continue
}
maybeCandidateAddr := maybeCandidatePrefix.Addr()
for _, selfPrefix := range self.Addresses().All() {
if !selfPrefix.IsSingleIP() {
if !nodeHasCap(filt, maybeCandidate, self, tailcfg.PeerCapabilityRelayTarget) {
continue
}
relayServers.Add(candidatePeerRelay{
nodeKey: maybeCandidate.Key(),
discoKey: maybeCandidate.DiscoKey(),
derpHomeRegionID: uint16(maybeCandidate.HomeDERP()),
})
}
c.relayManager.handleRelayServersSet(relayServers)
if len(relayServers) > 0 {
c.hasPeerRelayServers.Store(true)
} else {
c.hasPeerRelayServers.Store(false)
}
}
// nodeHasCap returns true if src has cap on dst, otherwise it returns false.
func nodeHasCap(filt *filter.Filter, src, dst tailcfg.NodeView, cap tailcfg.PeerCapability) bool {
if filt == nil ||
!src.Valid() ||
!dst.Valid() {
return false
}
for _, srcPrefix := range src.Addresses().All() {
if !srcPrefix.IsSingleIP() {
continue
}
srcAddr := srcPrefix.Addr()
for _, dstPrefix := range dst.Addresses().All() {
if !dstPrefix.IsSingleIP() {
continue
}
selfAddr := selfPrefix.Addr()
if selfAddr.BitLen() == maybeCandidateAddr.BitLen() { // same address family
if filt.CapsWithValues(maybeCandidateAddr, selfAddr).HasCapability(tailcfg.PeerCapabilityRelayTarget) {
for _, s := range maybeCandidate.Hostinfo().Services().All() {
if maybeCandidateAddr.Is4() && s.Proto == tailcfg.PeerAPI4 ||
maybeCandidateAddr.Is6() && s.Proto == tailcfg.PeerAPI6 {
return netip.AddrPortFrom(maybeCandidateAddr, s.Port)
}
}
return netip.AddrPort{} // no peerAPI
} else {
// [nodeBackend.peerCapsLocked] only returns/considers the
// [tailcfg.PeerCapMap] between the passed src and the
// _first_ host (/32 or /128) address for self. We are
// consistent with that behavior here. If self and
// maybeCandidate host addresses are of the same address
// family they either have the capability or not. We do not
// check against additional host addresses of the same
// address family.
return netip.AddrPort{}
}
dstAddr := dstPrefix.Addr()
if dstAddr.BitLen() == srcAddr.BitLen() { // same address family
// [nodeBackend.peerCapsLocked] only returns/considers the
// [tailcfg.PeerCapMap] between the passed src and the _first_
// host (/32 or /128) address for self. We are consistent with
// that behavior here. If src and dst host addresses are of the
// same address family they either have the capability or not.
// We do not check against additional host addresses of the same
// address family.
return filt.CapsWithValues(srcAddr, dstAddr).HasCapability(cap)
}
}
}
return netip.AddrPort{}
return false
}
// candidatePeerRelay represents the identifiers and DERP home region ID for a
// peer relay server.
type candidatePeerRelay struct {
nodeKey key.NodePublic
discoKey key.DiscoPublic
derpHomeRegionID uint16
}
func (c *candidatePeerRelay) isValid() bool {
return !c.nodeKey.IsZero() && !c.discoKey.IsZero()
}
// onNodeViewsUpdate is called when a [NodeViewsUpdate] is received over the
@ -3792,18 +3981,22 @@ var (
metricRecvDiscoBadKey = clientmetric.NewCounter("magicsock_disco_recv_bad_key")
metricRecvDiscoBadParse = clientmetric.NewCounter("magicsock_disco_recv_bad_parse")
metricRecvDiscoUDP = clientmetric.NewCounter("magicsock_disco_recv_udp")
metricRecvDiscoDERP = clientmetric.NewCounter("magicsock_disco_recv_derp")
metricRecvDiscoPing = clientmetric.NewCounter("magicsock_disco_recv_ping")
metricRecvDiscoPong = clientmetric.NewCounter("magicsock_disco_recv_pong")
metricRecvDiscoCallMeMaybe = clientmetric.NewCounter("magicsock_disco_recv_callmemaybe")
metricRecvDiscoCallMeMaybeVia = clientmetric.NewCounter("magicsock_disco_recv_callmemaybevia")
metricRecvDiscoCallMeMaybeBadNode = clientmetric.NewCounter("magicsock_disco_recv_callmemaybe_bad_node")
metricRecvDiscoCallMeMaybeViaBadNode = clientmetric.NewCounter("magicsock_disco_recv_callmemaybevia_bad_node")
metricRecvDiscoCallMeMaybeBadDisco = clientmetric.NewCounter("magicsock_disco_recv_callmemaybe_bad_disco")
metricRecvDiscoCallMeMaybeViaBadDisco = clientmetric.NewCounter("magicsock_disco_recv_callmemaybevia_bad_disco")
metricRecvDiscoDERPPeerNotHere = clientmetric.NewCounter("magicsock_disco_recv_derp_peer_not_here")
metricRecvDiscoDERPPeerGoneUnknown = clientmetric.NewCounter("magicsock_disco_recv_derp_peer_gone_unknown")
metricRecvDiscoUDP = clientmetric.NewCounter("magicsock_disco_recv_udp")
metricRecvDiscoDERP = clientmetric.NewCounter("magicsock_disco_recv_derp")
metricRecvDiscoPing = clientmetric.NewCounter("magicsock_disco_recv_ping")
metricRecvDiscoPong = clientmetric.NewCounter("magicsock_disco_recv_pong")
metricRecvDiscoCallMeMaybe = clientmetric.NewCounter("magicsock_disco_recv_callmemaybe")
metricRecvDiscoCallMeMaybeVia = clientmetric.NewCounter("magicsock_disco_recv_callmemaybevia")
metricRecvDiscoCallMeMaybeBadNode = clientmetric.NewCounter("magicsock_disco_recv_callmemaybe_bad_node")
metricRecvDiscoCallMeMaybeViaBadNode = clientmetric.NewCounter("magicsock_disco_recv_callmemaybevia_bad_node")
metricRecvDiscoCallMeMaybeBadDisco = clientmetric.NewCounter("magicsock_disco_recv_callmemaybe_bad_disco")
metricRecvDiscoCallMeMaybeViaBadDisco = clientmetric.NewCounter("magicsock_disco_recv_callmemaybevia_bad_disco")
metricRecvDiscoAllocUDPRelayEndpointRequest = clientmetric.NewCounter("magicsock_disco_recv_alloc_udp_relay_endpoint_request")
metricRecvDiscoAllocUDPRelayEndpointRequestBadDisco = clientmetric.NewCounter("magicsock_disco_recv_alloc_udp_relay_endpoint_request_bad_disco")
metricRecvDiscoAllocUDPRelayEndpointResponseBadDisco = clientmetric.NewCounter("magicsock_disco_recv_alloc_udp_relay_endpoint_response_bad_disco")
metricRecvDiscoAllocUDPRelayEndpointResponse = clientmetric.NewCounter("magicsock_disco_recv_alloc_udp_relay_endpoint_response")
metricRecvDiscoDERPPeerNotHere = clientmetric.NewCounter("magicsock_disco_recv_derp_peer_not_here")
metricRecvDiscoDERPPeerGoneUnknown = clientmetric.NewCounter("magicsock_disco_recv_derp_peer_gone_unknown")
// metricDERPHomeChange is how many times our DERP home region DI has
// changed from non-zero to a different non-zero.
metricDERPHomeChange = clientmetric.NewCounter("derp_home_change")
@ -3985,6 +4178,22 @@ func (le *lazyEndpoint) FromPeer(peerPublicKey [32]byte) {
}
// PeerRelays returns the current set of candidate peer relays.
func (c *Conn) PeerRelays() set.Set[netip.AddrPort] {
return c.relayManager.getServers()
func (c *Conn) PeerRelays() set.Set[netip.Addr] {
candidatePeerRelays := c.relayManager.getServers()
servers := make(set.Set[netip.Addr], len(candidatePeerRelays))
c.mu.Lock()
defer c.mu.Unlock()
for relay := range candidatePeerRelays {
pi, ok := c.peerMap.byNodeKey[relay.nodeKey]
if !ok {
if c.self.Key().Compare(relay.nodeKey) == 0 {
if c.self.Addresses().Len() > 0 {
servers.Add(c.self.Addresses().At(0).Addr())
}
}
continue
}
servers.Add(pi.ep.nodeAddr)
}
return servers
}

519
wgengine/magicsock/magicsock_test.go
View File

@ -19,7 +19,6 @@ import (
"net/http/httptest"
"net/netip"
"os"
"reflect"
"runtime"
"strconv"
"strings"
@ -64,6 +63,7 @@ import (
"tailscale.com/types/netmap"
"tailscale.com/types/nettype"
"tailscale.com/types/ptr"
"tailscale.com/types/views"
"tailscale.com/util/cibuild"
"tailscale.com/util/eventbus"
"tailscale.com/util/must"
@ -3384,258 +3384,6 @@ func Test_virtualNetworkID(t *testing.T) {
}
}
func Test_peerAPIIfCandidateRelayServer(t *testing.T) {
hostInfo := &tailcfg.Hostinfo{
Services: []tailcfg.Service{
{
Proto: tailcfg.PeerAPI4,
Port: 4,
},
{
Proto: tailcfg.PeerAPI6,
Port: 6,
},
},
}
selfOnlyIPv4 := &tailcfg.Node{
ID: 1,
// Intentionally set a value < 120 to verify the statically compiled
// [tailcfg.CurrentCapabilityVersion] is used when self is
// maybeCandidate.
Cap: 119,
Addresses: []netip.Prefix{
netip.MustParsePrefix("1.1.1.1/32"),
},
Hostinfo: hostInfo.View(),
}
selfOnlyIPv6 := selfOnlyIPv4.Clone()
selfOnlyIPv6.Addresses[0] = netip.MustParsePrefix("::1/128")
peerOnlyIPv4 := &tailcfg.Node{
ID: 2,
Cap: 120,
Addresses: []netip.Prefix{
netip.MustParsePrefix("2.2.2.2/32"),
},
Hostinfo: hostInfo.View(),
}
peerOnlyIPv4NotCapable := peerOnlyIPv4.Clone()
peerOnlyIPv4NotCapable.Cap = 119
peerOnlyIPv6 := peerOnlyIPv4.Clone()
peerOnlyIPv6.Addresses[0] = netip.MustParsePrefix("::2/128")
peerOnlyIPv4ZeroCapVer := peerOnlyIPv4.Clone()
peerOnlyIPv4ZeroCapVer.Cap = 0
peerOnlyIPv4NilHostinfo := peerOnlyIPv4.Clone()
peerOnlyIPv4NilHostinfo.Hostinfo = tailcfg.HostinfoView{}
tests := []struct {
name string
filt *filter.Filter
self tailcfg.NodeView
maybeCandidate tailcfg.NodeView
want netip.AddrPort
}{
{
name: "match v4",
filt: filter.New([]filtertype.Match{
{
Srcs: []netip.Prefix{netip.MustParsePrefix("2.2.2.2/32")},
Caps: []filtertype.CapMatch{
{
Dst: netip.MustParsePrefix("1.1.1.1/32"),
Cap: tailcfg.PeerCapabilityRelayTarget,
},
},
},
}, nil, nil, nil, nil, nil),
self: selfOnlyIPv4.View(),
maybeCandidate: peerOnlyIPv4.View(),
want: netip.MustParseAddrPort("2.2.2.2:4"),
},
{
name: "match v4 self",
filt: filter.New([]filtertype.Match{
{
Srcs: []netip.Prefix{selfOnlyIPv4.Addresses[0]},
Caps: []filtertype.CapMatch{
{
Dst: selfOnlyIPv4.Addresses[0],
Cap: tailcfg.PeerCapabilityRelayTarget,
},
},
},
}, nil, nil, nil, nil, nil),
self: selfOnlyIPv4.View(),
maybeCandidate: selfOnlyIPv4.View(),
want: netip.AddrPortFrom(selfOnlyIPv4.Addresses[0].Addr(), 4),
},
{
name: "match v6",
filt: filter.New([]filtertype.Match{
{
Srcs: []netip.Prefix{netip.MustParsePrefix("::2/128")},
Caps: []filtertype.CapMatch{
{
Dst: netip.MustParsePrefix("::1/128"),
Cap: tailcfg.PeerCapabilityRelayTarget,
},
},
},
}, nil, nil, nil, nil, nil),
self: selfOnlyIPv6.View(),
maybeCandidate: peerOnlyIPv6.View(),
want: netip.MustParseAddrPort("[::2]:6"),
},
{
name: "match v6 self",
filt: filter.New([]filtertype.Match{
{
Srcs: []netip.Prefix{selfOnlyIPv6.Addresses[0]},
Caps: []filtertype.CapMatch{
{
Dst: selfOnlyIPv6.Addresses[0],
Cap: tailcfg.PeerCapabilityRelayTarget,
},
},
},
}, nil, nil, nil, nil, nil),
self: selfOnlyIPv6.View(),
maybeCandidate: selfOnlyIPv6.View(),
want: netip.AddrPortFrom(selfOnlyIPv6.Addresses[0].Addr(), 6),
},
{
name: "peer incapable",
filt: filter.New([]filtertype.Match{
{
Srcs: []netip.Prefix{netip.MustParsePrefix("2.2.2.2/32")},
Caps: []filtertype.CapMatch{
{
Dst: netip.MustParsePrefix("1.1.1.1/32"),
Cap: tailcfg.PeerCapabilityRelayTarget,
},
},
},
}, nil, nil, nil, nil, nil),
self: selfOnlyIPv4.View(),
maybeCandidate: peerOnlyIPv4NotCapable.View(),
},
{
name: "no match dst",
filt: filter.New([]filtertype.Match{
{
Srcs: []netip.Prefix{netip.MustParsePrefix("::2/128")},
Caps: []filtertype.CapMatch{
{
Dst: netip.MustParsePrefix("::3/128"),
Cap: tailcfg.PeerCapabilityRelayTarget,
},
},
},
}, nil, nil, nil, nil, nil),
self: selfOnlyIPv6.View(),
maybeCandidate: peerOnlyIPv6.View(),
},
{
name: "no match peer cap",
filt: filter.New([]filtertype.Match{
{
Srcs: []netip.Prefix{netip.MustParsePrefix("::2/128")},
Caps: []filtertype.CapMatch{
{
Dst: netip.MustParsePrefix("::1/128"),
Cap: tailcfg.PeerCapabilityIngress,
},
},
},
}, nil, nil, nil, nil, nil),
self: selfOnlyIPv6.View(),
maybeCandidate: peerOnlyIPv6.View(),
},
{
name: "cap ver not relay capable",
filt: filter.New([]filtertype.Match{
{
Srcs: []netip.Prefix{netip.MustParsePrefix("2.2.2.2/32")},
Caps: []filtertype.CapMatch{
{
Dst: netip.MustParsePrefix("1.1.1.1/32"),
Cap: tailcfg.PeerCapabilityRelayTarget,
},
},
},
}, nil, nil, nil, nil, nil),
self: peerOnlyIPv4.View(),
maybeCandidate: peerOnlyIPv4ZeroCapVer.View(),
},
{
name: "nil filt",
filt: nil,
self: selfOnlyIPv4.View(),
maybeCandidate: peerOnlyIPv4.View(),
},
{
name: "nil self",
filt: filter.New([]filtertype.Match{
{
Srcs: []netip.Prefix{netip.MustParsePrefix("2.2.2.2/32")},
Caps: []filtertype.CapMatch{
{
Dst: netip.MustParsePrefix("1.1.1.1/32"),
Cap: tailcfg.PeerCapabilityRelayTarget,
},
},
},
}, nil, nil, nil, nil, nil),
self: tailcfg.NodeView{},
maybeCandidate: peerOnlyIPv4.View(),
},
{
name: "nil peer",
filt: filter.New([]filtertype.Match{
{
Srcs: []netip.Prefix{netip.MustParsePrefix("2.2.2.2/32")},
Caps: []filtertype.CapMatch{
{
Dst: netip.MustParsePrefix("1.1.1.1/32"),
Cap: tailcfg.PeerCapabilityRelayTarget,
},
},
},
}, nil, nil, nil, nil, nil),
self: selfOnlyIPv4.View(),
maybeCandidate: tailcfg.NodeView{},
},
{
name: "nil peer hostinfo",
filt: filter.New([]filtertype.Match{
{
Srcs: []netip.Prefix{netip.MustParsePrefix("2.2.2.2/32")},
Caps: []filtertype.CapMatch{
{
Dst: netip.MustParsePrefix("1.1.1.1/32"),
Cap: tailcfg.PeerCapabilityRelayTarget,
},
},
},
}, nil, nil, nil, nil, nil),
self: selfOnlyIPv4.View(),
maybeCandidate: peerOnlyIPv4NilHostinfo.View(),
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
if got := peerAPIIfCandidateRelayServer(tt.filt, tt.self, tt.maybeCandidate); !reflect.DeepEqual(got, tt.want) {
t.Errorf("peerAPIIfCandidateRelayServer() = %v, want %v", got, tt.want)
}
})
}
}
func Test_looksLikeInitiationMsg(t *testing.T) {
initMsg := make([]byte, device.MessageInitiationSize)
binary.BigEndian.PutUint32(initMsg, device.MessageInitiationType)
@ -3675,3 +3423,268 @@ func Test_looksLikeInitiationMsg(t *testing.T) {
})
}
}
func Test_nodeHasCap(t *testing.T) {
nodeAOnlyIPv4 := &tailcfg.Node{
ID: 1,
Addresses: []netip.Prefix{
netip.MustParsePrefix("1.1.1.1/32"),
},
}
nodeBOnlyIPv6 := nodeAOnlyIPv4.Clone()
nodeBOnlyIPv6.Addresses[0] = netip.MustParsePrefix("::1/128")
nodeCOnlyIPv4 := &tailcfg.Node{
ID: 2,
Addresses: []netip.Prefix{
netip.MustParsePrefix("2.2.2.2/32"),
},
}
nodeDOnlyIPv6 := nodeCOnlyIPv4.Clone()
nodeDOnlyIPv6.Addresses[0] = netip.MustParsePrefix("::2/128")
tests := []struct {
name string
filt *filter.Filter
src tailcfg.NodeView
dst tailcfg.NodeView
cap tailcfg.PeerCapability
want bool
}{
{
name: "match v4",
filt: filter.New([]filtertype.Match{
{
Srcs: []netip.Prefix{netip.MustParsePrefix("2.2.2.2/32")},
Caps: []filtertype.CapMatch{
{
Dst: netip.MustParsePrefix("1.1.1.1/32"),
Cap: tailcfg.PeerCapabilityRelayTarget,
},
},
},
}, nil, nil, nil, nil, nil),
src: nodeCOnlyIPv4.View(),
dst: nodeAOnlyIPv4.View(),
cap: tailcfg.PeerCapabilityRelayTarget,
want: true,
},
{
name: "match v6",
filt: filter.New([]filtertype.Match{
{
Srcs: []netip.Prefix{netip.MustParsePrefix("::2/128")},
Caps: []filtertype.CapMatch{
{
Dst: netip.MustParsePrefix("::1/128"),
Cap: tailcfg.PeerCapabilityRelayTarget,
},
},
},
}, nil, nil, nil, nil, nil),
src: nodeDOnlyIPv6.View(),
dst: nodeBOnlyIPv6.View(),
cap: tailcfg.PeerCapabilityRelayTarget,
want: true,
},
{
name: "no match CapMatch Dst",
filt: filter.New([]filtertype.Match{
{
Srcs: []netip.Prefix{netip.MustParsePrefix("::2/128")},
Caps: []filtertype.CapMatch{
{
Dst: netip.MustParsePrefix("::3/128"),
Cap: tailcfg.PeerCapabilityRelayTarget,
},
},
},
}, nil, nil, nil, nil, nil),
src: nodeDOnlyIPv6.View(),
dst: nodeBOnlyIPv6.View(),
cap: tailcfg.PeerCapabilityRelayTarget,
want: false,
},
{
name: "no match peer cap",
filt: filter.New([]filtertype.Match{
{
Srcs: []netip.Prefix{netip.MustParsePrefix("::2/128")},
Caps: []filtertype.CapMatch{
{
Dst: netip.MustParsePrefix("::1/128"),
Cap: tailcfg.PeerCapabilityIngress,
},
},
},
}, nil, nil, nil, nil, nil),
src: nodeDOnlyIPv6.View(),
dst: nodeBOnlyIPv6.View(),
cap: tailcfg.PeerCapabilityRelayTarget,
want: false,
},
{
name: "nil src",
filt: filter.New([]filtertype.Match{
{
Srcs: []netip.Prefix{netip.MustParsePrefix("2.2.2.2/32")},
Caps: []filtertype.CapMatch{
{
Dst: netip.MustParsePrefix("1.1.1.1/32"),
Cap: tailcfg.PeerCapabilityRelayTarget,
},
},
},
}, nil, nil, nil, nil, nil),
src: tailcfg.NodeView{},
dst: nodeAOnlyIPv4.View(),
cap: tailcfg.PeerCapabilityRelayTarget,
want: false,
},
{
name: "nil dst",
filt: filter.New([]filtertype.Match{
{
Srcs: []netip.Prefix{netip.MustParsePrefix("2.2.2.2/32")},
Caps: []filtertype.CapMatch{
{
Dst: netip.MustParsePrefix("1.1.1.1/32"),
Cap: tailcfg.PeerCapabilityRelayTarget,
},
},
},
}, nil, nil, nil, nil, nil),
src: nodeCOnlyIPv4.View(),
dst: tailcfg.NodeView{},
cap: tailcfg.PeerCapabilityRelayTarget,
want: false,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
if got := nodeHasCap(tt.filt, tt.src, tt.dst, tt.cap); got != tt.want {
t.Errorf("nodeHasCap() = %v, want %v", got, tt.want)
}
})
}
}
func TestConn_updateRelayServersSet(t *testing.T) {
peerNodeCandidateRelay := &tailcfg.Node{
Cap: 121,
ID: 1,
Addresses: []netip.Prefix{
netip.MustParsePrefix("1.1.1.1/32"),
},
HomeDERP: 1,
Key: key.NewNode().Public(),
DiscoKey: key.NewDisco().Public(),
}
peerNodeNotCandidateRelayCapVer := &tailcfg.Node{
Cap: 120, // intentionally lower to fail capVer check
ID: 1,
Addresses: []netip.Prefix{
netip.MustParsePrefix("1.1.1.1/32"),
},
HomeDERP: 1,
Key: key.NewNode().Public(),
DiscoKey: key.NewDisco().Public(),
}
selfNode := &tailcfg.Node{
Cap: 120, // intentionally lower than capVerIsRelayCapable to verify self check
ID: 2,
Addresses: []netip.Prefix{
netip.MustParsePrefix("2.2.2.2/32"),
},
HomeDERP: 2,
Key: key.NewNode().Public(),
DiscoKey: key.NewDisco().Public(),
}
tests := []struct {
name string
filt *filter.Filter
self tailcfg.NodeView
peers views.Slice[tailcfg.NodeView]
wantRelayServers set.Set[candidatePeerRelay]
}{
{
name: "candidate relay server",
filt: filter.New([]filtertype.Match{
{
Srcs: peerNodeCandidateRelay.Addresses,
Caps: []filtertype.CapMatch{
{
Dst: selfNode.Addresses[0],
Cap: tailcfg.PeerCapabilityRelayTarget,
},
},
},
}, nil, nil, nil, nil, nil),
self: selfNode.View(),
peers: views.SliceOf([]tailcfg.NodeView{peerNodeCandidateRelay.View()}),
wantRelayServers: set.SetOf([]candidatePeerRelay{
{
nodeKey: peerNodeCandidateRelay.Key,
discoKey: peerNodeCandidateRelay.DiscoKey,
derpHomeRegionID: 1,
},
}),
},
{
name: "self candidate relay server",
filt: filter.New([]filtertype.Match{
{
Srcs: selfNode.Addresses,
Caps: []filtertype.CapMatch{
{
Dst: selfNode.Addresses[0],
Cap: tailcfg.PeerCapabilityRelayTarget,
},
},
},
}, nil, nil, nil, nil, nil),
self: selfNode.View(),
peers: views.SliceOf([]tailcfg.NodeView{selfNode.View()}),
wantRelayServers: set.SetOf([]candidatePeerRelay{
{
nodeKey: selfNode.Key,
discoKey: selfNode.DiscoKey,
derpHomeRegionID: 2,
},
}),
},
{
name: "no candidate relay server",
filt: filter.New([]filtertype.Match{
{
Srcs: peerNodeNotCandidateRelayCapVer.Addresses,
Caps: []filtertype.CapMatch{
{
Dst: selfNode.Addresses[0],
Cap: tailcfg.PeerCapabilityRelayTarget,
},
},
},
}, nil, nil, nil, nil, nil),
self: selfNode.View(),
peers: views.SliceOf([]tailcfg.NodeView{peerNodeNotCandidateRelayCapVer.View()}),
wantRelayServers: make(set.Set[candidatePeerRelay]),
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
c := &Conn{}
c.updateRelayServersSet(tt.filt, tt.self, tt.peers)
got := c.relayManager.getServers()
if !got.Equal(tt.wantRelayServers) {
t.Fatalf("got: %v != want: %v", got, tt.wantRelayServers)
}
if len(tt.wantRelayServers) > 0 != c.hasPeerRelayServers.Load() {
t.Fatalf("c.hasPeerRelayServers: %v != wantRelayServers: %v", c.hasPeerRelayServers.Load(), tt.wantRelayServers)
}
})
}
}

508
wgengine/magicsock/relaymanager.go
View File

@ -4,23 +4,18 @@
package magicsock
import (
"bytes"
"context"
"encoding/json"
"errors"
"fmt"
"io"
"net/http"
"net/netip"
"strconv"
"sync"
"time"
"tailscale.com/disco"
"tailscale.com/net/stun"
udprelay "tailscale.com/net/udprelay/endpoint"
"tailscale.com/tailcfg"
"tailscale.com/tstime"
"tailscale.com/types/key"
"tailscale.com/util/httpm"
"tailscale.com/util/set"
)
@ -38,26 +33,28 @@ type relayManager struct {
// ===================================================================
// The following fields are owned by a single goroutine, runLoop().
serversByAddrPort map[netip.AddrPort]key.DiscoPublic
serversByDisco map[key.DiscoPublic]netip.AddrPort
allocWorkByEndpoint map[*endpoint]*relayEndpointAllocWork
handshakeWorkByEndpointByServerDisco map[*endpoint]map[key.DiscoPublic]*relayHandshakeWork
handshakeWorkByServerDiscoVNI map[serverDiscoVNI]*relayHandshakeWork
handshakeWorkAwaitingPong map[*relayHandshakeWork]addrPortVNI
addrPortVNIToHandshakeWork map[addrPortVNI]*relayHandshakeWork
handshakeGeneration uint32
serversByNodeKey map[key.NodePublic]candidatePeerRelay
allocWorkByCandidatePeerRelayByEndpoint map[*endpoint]map[candidatePeerRelay]*relayEndpointAllocWork
allocWorkByDiscoKeysByServerNodeKey map[key.NodePublic]map[key.SortedPairOfDiscoPublic]*relayEndpointAllocWork
handshakeWorkByServerDiscoByEndpoint map[*endpoint]map[key.DiscoPublic]*relayHandshakeWork
handshakeWorkByServerDiscoVNI map[serverDiscoVNI]*relayHandshakeWork
handshakeWorkAwaitingPong map[*relayHandshakeWork]addrPortVNI
addrPortVNIToHandshakeWork map[addrPortVNI]*relayHandshakeWork
handshakeGeneration uint32
allocGeneration uint32
// ===================================================================
// The following chan fields serve event inputs to a single goroutine,
// runLoop().
startDiscoveryCh chan endpointWithLastBest
allocateWorkDoneCh chan relayEndpointAllocWorkDoneEvent
handshakeWorkDoneCh chan relayEndpointHandshakeWorkDoneEvent
cancelWorkCh chan *endpoint
newServerEndpointCh chan newRelayServerEndpointEvent
rxHandshakeDiscoMsgCh chan relayHandshakeDiscoMsgEvent
serversCh chan set.Set[netip.AddrPort]
getServersCh chan chan set.Set[netip.AddrPort]
startDiscoveryCh chan endpointWithLastBest
allocateWorkDoneCh chan relayEndpointAllocWorkDoneEvent
handshakeWorkDoneCh chan relayEndpointHandshakeWorkDoneEvent
cancelWorkCh chan *endpoint
newServerEndpointCh chan newRelayServerEndpointEvent
rxDiscoMsgCh chan relayDiscoMsgEvent
serversCh chan set.Set[candidatePeerRelay]
getServersCh chan chan set.Set[candidatePeerRelay]
derpHomeChangeCh chan derpHomeChangeEvent
discoInfoMu sync.Mutex // guards the following field
discoInfoByServerDisco map[key.DiscoPublic]*relayHandshakeDiscoInfo
@ -86,7 +83,7 @@ type relayHandshakeWork struct {
// relayManager.handshakeWorkDoneCh if runLoop() can receive it. runLoop()
// must select{} read on doneCh to prevent deadlock when attempting to write
// to rxDiscoMsgCh.
rxDiscoMsgCh chan relayHandshakeDiscoMsgEvent
rxDiscoMsgCh chan relayDiscoMsgEvent
doneCh chan relayEndpointHandshakeWorkDoneEvent
ctx context.Context
@ -100,14 +97,15 @@ type relayHandshakeWork struct {
type newRelayServerEndpointEvent struct {
wlb endpointWithLastBest
se udprelay.ServerEndpoint
server netip.AddrPort // zero value if learned via [disco.CallMeMaybeVia]
server candidatePeerRelay // zero value if learned via [disco.CallMeMaybeVia]
}
// relayEndpointAllocWorkDoneEvent indicates relay server endpoint allocation
// work for an [*endpoint] has completed. This structure is immutable once
// initialized.
type relayEndpointAllocWorkDoneEvent struct {
work *relayEndpointAllocWork
work *relayEndpointAllocWork
allocated udprelay.ServerEndpoint // !allocated.ServerDisco.IsZero() if allocation succeeded
}
// relayEndpointHandshakeWorkDoneEvent indicates relay server endpoint handshake
@ -122,18 +120,42 @@ type relayEndpointHandshakeWorkDoneEvent struct {
// hasActiveWorkRunLoop returns true if there is outstanding allocation or
// handshaking work for any endpoint, otherwise it returns false.
func (r *relayManager) hasActiveWorkRunLoop() bool {
return len(r.allocWorkByEndpoint) > 0 || len(r.handshakeWorkByEndpointByServerDisco) > 0
return len(r.allocWorkByCandidatePeerRelayByEndpoint) > 0 || len(r.handshakeWorkByServerDiscoByEndpoint) > 0
}
// hasActiveWorkForEndpointRunLoop returns true if there is outstanding
// allocation or handshaking work for the provided endpoint, otherwise it
// returns false.
func (r *relayManager) hasActiveWorkForEndpointRunLoop(ep *endpoint) bool {
_, handshakeWork := r.handshakeWorkByEndpointByServerDisco[ep]
_, allocWork := r.allocWorkByEndpoint[ep]
_, handshakeWork := r.handshakeWorkByServerDiscoByEndpoint[ep]
_, allocWork := r.allocWorkByCandidatePeerRelayByEndpoint[ep]
return handshakeWork || allocWork
}
// derpHomeChangeEvent represents a change in the DERP home region for the
// node identified by nodeKey. This structure is immutable once initialized.
type derpHomeChangeEvent struct {
nodeKey key.NodePublic
regionID uint16
}
// handleDERPHomeChange handles a DERP home change event for nodeKey and
// regionID.
func (r *relayManager) handleDERPHomeChange(nodeKey key.NodePublic, regionID uint16) {
relayManagerInputEvent(r, nil, &r.derpHomeChangeCh, derpHomeChangeEvent{
nodeKey: nodeKey,
regionID: regionID,
})
}
func (r *relayManager) handleDERPHomeChangeRunLoop(event derpHomeChangeEvent) {
c, ok := r.serversByNodeKey[event.nodeKey]
if ok {
c.derpHomeRegionID = event.regionID
r.serversByNodeKey[event.nodeKey] = c
}
}
// runLoop is a form of event loop. It ensures exclusive access to most of
// [relayManager] state.
func (r *relayManager) runLoop() {
@ -151,13 +173,7 @@ func (r *relayManager) runLoop() {
return
}
case done := <-r.allocateWorkDoneCh:
work, ok := r.allocWorkByEndpoint[done.work.ep]
if ok && work == done.work {
// Verify the work in the map is the same as the one that we're
// cleaning up. New events on r.startDiscoveryCh can
// overwrite pre-existing keys.
delete(r.allocWorkByEndpoint, done.work.ep)
}
r.handleAllocWorkDoneRunLoop(done)
if !r.hasActiveWorkRunLoop() {
return
}
@ -176,8 +192,8 @@ func (r *relayManager) runLoop() {
if !r.hasActiveWorkRunLoop() {
return
}
case discoMsgEvent := <-r.rxHandshakeDiscoMsgCh:
r.handleRxHandshakeDiscoMsgRunLoop(discoMsgEvent)
case discoMsgEvent := <-r.rxDiscoMsgCh:
r.handleRxDiscoMsgRunLoop(discoMsgEvent)
if !r.hasActiveWorkRunLoop() {
return
}
@ -191,69 +207,77 @@ func (r *relayManager) runLoop() {
if !r.hasActiveWorkRunLoop() {
return
}
case derpHomeChange := <-r.derpHomeChangeCh:
r.handleDERPHomeChangeRunLoop(derpHomeChange)
if !r.hasActiveWorkRunLoop() {
return
}
}
}
}
func (r *relayManager) handleGetServersRunLoop(getServersCh chan set.Set[netip.AddrPort]) {
servers := make(set.Set[netip.AddrPort], len(r.serversByAddrPort))
for server := range r.serversByAddrPort {
servers.Add(server)
func (r *relayManager) handleGetServersRunLoop(getServersCh chan set.Set[candidatePeerRelay]) {
servers := make(set.Set[candidatePeerRelay], len(r.serversByNodeKey))
for _, v := range r.serversByNodeKey {
servers.Add(v)
}
getServersCh <- servers
}
func (r *relayManager) getServers() set.Set[netip.AddrPort] {
ch := make(chan set.Set[netip.AddrPort])
func (r *relayManager) getServers() set.Set[candidatePeerRelay] {
ch := make(chan set.Set[candidatePeerRelay])
relayManagerInputEvent(r, nil, &r.getServersCh, ch)
return <-ch
}
func (r *relayManager) handleServersUpdateRunLoop(update set.Set[netip.AddrPort]) {
for k, v := range r.serversByAddrPort {
if !update.Contains(k) {
delete(r.serversByAddrPort, k)
delete(r.serversByDisco, v)
func (r *relayManager) handleServersUpdateRunLoop(update set.Set[candidatePeerRelay]) {
for _, v := range r.serversByNodeKey {
if !update.Contains(v) {
delete(r.serversByNodeKey, v.nodeKey)
}
}
for _, v := range update.Slice() {
_, ok := r.serversByAddrPort[v]
if ok {
// don't zero known disco keys
continue
}
r.serversByAddrPort[v] = key.DiscoPublic{}
r.serversByNodeKey[v.nodeKey] = v
}
}
type relayHandshakeDiscoMsgEvent struct {
conn *Conn // for access to [Conn] if there is no associated [relayHandshakeWork]
msg disco.Message
disco key.DiscoPublic
from netip.AddrPort
vni uint32
at time.Time
type relayDiscoMsgEvent struct {
conn *Conn // for access to [Conn] if there is no associated [relayHandshakeWork]
msg disco.Message
relayServerNodeKey key.NodePublic // nonzero if msg is a [*disco.AllocateUDPRelayEndpointResponse]
disco key.DiscoPublic
from netip.AddrPort
vni uint32
at time.Time
}
// relayEndpointAllocWork serves to track in-progress relay endpoint allocation
// for an [*endpoint]. This structure is immutable once initialized.
type relayEndpointAllocWork struct {
// ep is the [*endpoint] associated with the work
ep *endpoint
// cancel() will signal all associated goroutines to return
wlb endpointWithLastBest
discoKeys key.SortedPairOfDiscoPublic
candidatePeerRelay candidatePeerRelay
// allocateServerEndpoint() always writes to doneCh (len 1) when it
// returns. It may end up writing the same event afterward to
// [relayManager.allocateWorkDoneCh] if runLoop() can receive it. runLoop()
// must select{} read on doneCh to prevent deadlock when attempting to write
// to rxDiscoMsgCh.
rxDiscoMsgCh chan *disco.AllocateUDPRelayEndpointResponse
doneCh chan relayEndpointAllocWorkDoneEvent
ctx context.Context
cancel context.CancelFunc
// wg.Wait() will return once all associated goroutines have returned
wg *sync.WaitGroup
}
// init initializes [relayManager] if it is not already initialized.
func (r *relayManager) init() {
r.initOnce.Do(func() {
r.discoInfoByServerDisco = make(map[key.DiscoPublic]*relayHandshakeDiscoInfo)
r.serversByDisco = make(map[key.DiscoPublic]netip.AddrPort)
r.serversByAddrPort = make(map[netip.AddrPort]key.DiscoPublic)
r.allocWorkByEndpoint = make(map[*endpoint]*relayEndpointAllocWork)
r.handshakeWorkByEndpointByServerDisco = make(map[*endpoint]map[key.DiscoPublic]*relayHandshakeWork)
r.serversByNodeKey = make(map[key.NodePublic]candidatePeerRelay)
r.allocWorkByCandidatePeerRelayByEndpoint = make(map[*endpoint]map[candidatePeerRelay]*relayEndpointAllocWork)
r.allocWorkByDiscoKeysByServerNodeKey = make(map[key.NodePublic]map[key.SortedPairOfDiscoPublic]*relayEndpointAllocWork)
r.handshakeWorkByServerDiscoByEndpoint = make(map[*endpoint]map[key.DiscoPublic]*relayHandshakeWork)
r.handshakeWorkByServerDiscoVNI = make(map[serverDiscoVNI]*relayHandshakeWork)
r.handshakeWorkAwaitingPong = make(map[*relayHandshakeWork]addrPortVNI)
r.addrPortVNIToHandshakeWork = make(map[addrPortVNI]*relayHandshakeWork)
@ -262,9 +286,10 @@ func (r *relayManager) init() {
r.handshakeWorkDoneCh = make(chan relayEndpointHandshakeWorkDoneEvent)
r.cancelWorkCh = make(chan *endpoint)
r.newServerEndpointCh = make(chan newRelayServerEndpointEvent)
r.rxHandshakeDiscoMsgCh = make(chan relayHandshakeDiscoMsgEvent)
r.serversCh = make(chan set.Set[netip.AddrPort])
r.getServersCh = make(chan chan set.Set[netip.AddrPort])
r.rxDiscoMsgCh = make(chan relayDiscoMsgEvent)
r.serversCh = make(chan set.Set[candidatePeerRelay])
r.getServersCh = make(chan chan set.Set[candidatePeerRelay])
r.derpHomeChangeCh = make(chan derpHomeChangeEvent)
r.runLoopStoppedCh = make(chan struct{}, 1)
r.runLoopStoppedCh <- struct{}{}
})
@ -330,6 +355,7 @@ func (r *relayManager) discoInfo(serverDisco key.DiscoPublic) (_ *discoInfo, ok
func (r *relayManager) handleCallMeMaybeVia(ep *endpoint, lastBest addrQuality, lastBestIsTrusted bool, dm *disco.CallMeMaybeVia) {
se := udprelay.ServerEndpoint{
ServerDisco: dm.ServerDisco,
ClientDisco: dm.ClientDisco,
LamportID: dm.LamportID,
AddrPorts: dm.AddrPorts,
VNI: dm.VNI,
@ -346,14 +372,25 @@ func (r *relayManager) handleCallMeMaybeVia(ep *endpoint, lastBest addrQuality,
})
}
// handleGeneveEncapDiscoMsg handles reception of Geneve-encapsulated disco
// messages.
func (r *relayManager) handleGeneveEncapDiscoMsg(conn *Conn, dm disco.Message, di *discoInfo, src epAddr) {
relayManagerInputEvent(r, nil, &r.rxHandshakeDiscoMsgCh, relayHandshakeDiscoMsgEvent{conn: conn, msg: dm, disco: di.discoKey, from: src.ap, vni: src.vni.get(), at: time.Now()})
// handleRxDiscoMsg handles reception of disco messages that [relayManager]
// may be interested in. This includes all Geneve-encapsulated disco messages
// and [*disco.AllocateUDPRelayEndpointResponse]. If dm is a
// [*disco.AllocateUDPRelayEndpointResponse] then relayServerNodeKey must be
// nonzero.
func (r *relayManager) handleRxDiscoMsg(conn *Conn, dm disco.Message, relayServerNodeKey key.NodePublic, discoKey key.DiscoPublic, src epAddr) {
relayManagerInputEvent(r, nil, &r.rxDiscoMsgCh, relayDiscoMsgEvent{
conn: conn,
msg: dm,
relayServerNodeKey: relayServerNodeKey,
disco: discoKey,
from: src.ap,
vni: src.vni.get(),
at: time.Now(),
})
}
// handleRelayServersSet handles an update of the complete relay server set.
func (r *relayManager) handleRelayServersSet(servers set.Set[netip.AddrPort]) {
func (r *relayManager) handleRelayServersSet(servers set.Set[candidatePeerRelay]) {
relayManagerInputEvent(r, nil, &r.serversCh, servers)
}
@ -396,7 +433,11 @@ type endpointWithLastBest struct {
// startUDPRelayPathDiscoveryFor starts UDP relay path discovery for ep on all
// known relay servers if ep has no in-progress work.
func (r *relayManager) startUDPRelayPathDiscoveryFor(ep *endpoint, lastBest addrQuality, lastBestIsTrusted bool) {
relayManagerInputEvent(r, nil, &r.startDiscoveryCh, endpointWithLastBest{ep, lastBest, lastBestIsTrusted})
relayManagerInputEvent(r, nil, &r.startDiscoveryCh, endpointWithLastBest{
ep: ep,
lastBest: lastBest,
lastBestIsTrusted: lastBestIsTrusted,
})
}
// stopWork stops all outstanding allocation & handshaking work for 'ep'.
@ -407,13 +448,15 @@ func (r *relayManager) stopWork(ep *endpoint) {
// stopWorkRunLoop cancels & clears outstanding allocation and handshaking
// work for 'ep'.
func (r *relayManager) stopWorkRunLoop(ep *endpoint) {
allocWork, ok := r.allocWorkByEndpoint[ep]
byDiscoKeys, ok := r.allocWorkByCandidatePeerRelayByEndpoint[ep]
if ok {
allocWork.cancel()
allocWork.wg.Wait()
delete(r.allocWorkByEndpoint, ep)
for _, work := range byDiscoKeys {
work.cancel()
done := <-work.doneCh
r.handleAllocWorkDoneRunLoop(done)
}
}
byServerDisco, ok := r.handshakeWorkByEndpointByServerDisco[ep]
byServerDisco, ok := r.handshakeWorkByServerDiscoByEndpoint[ep]
if ok {
for _, handshakeWork := range byServerDisco {
handshakeWork.cancel()
@ -430,13 +473,33 @@ type addrPortVNI struct {
vni uint32
}
func (r *relayManager) handleRxHandshakeDiscoMsgRunLoop(event relayHandshakeDiscoMsgEvent) {
func (r *relayManager) handleRxDiscoMsgRunLoop(event relayDiscoMsgEvent) {
var (
work *relayHandshakeWork
ok bool
)
apv := addrPortVNI{event.from, event.vni}
switch msg := event.msg.(type) {
case *disco.AllocateUDPRelayEndpointResponse:
sorted := key.NewSortedPairOfDiscoPublic(msg.ClientDisco[0], msg.ClientDisco[1])
byDiscoKeys, ok := r.allocWorkByDiscoKeysByServerNodeKey[event.relayServerNodeKey]
if !ok {
// No outstanding work tied to this relay sever, discard.
return
}
allocWork, ok := byDiscoKeys[sorted]
if !ok {
// No outstanding work tied to these disco keys, discard.
return
}
select {
case done := <-allocWork.doneCh:
// allocateServerEndpoint returned, clean up its state
r.handleAllocWorkDoneRunLoop(done)
return
case allocWork.rxDiscoMsgCh <- msg:
return
}
case *disco.BindUDPRelayEndpointChallenge:
work, ok = r.handshakeWorkByServerDiscoVNI[serverDiscoVNI{event.disco, event.vni}]
if !ok {
@ -504,8 +567,39 @@ func (r *relayManager) handleRxHandshakeDiscoMsgRunLoop(event relayHandshakeDisc
}
}
func (r *relayManager) handleAllocWorkDoneRunLoop(done relayEndpointAllocWorkDoneEvent) {
byCandidatePeerRelay, ok := r.allocWorkByCandidatePeerRelayByEndpoint[done.work.wlb.ep]
if !ok {
return
}
work, ok := byCandidatePeerRelay[done.work.candidatePeerRelay]
if !ok || work != done.work {
return
}
delete(byCandidatePeerRelay, done.work.candidatePeerRelay)
if len(byCandidatePeerRelay) == 0 {
delete(r.allocWorkByCandidatePeerRelayByEndpoint, done.work.wlb.ep)
}
byDiscoKeys, ok := r.allocWorkByDiscoKeysByServerNodeKey[done.work.candidatePeerRelay.nodeKey]
if !ok {
// unexpected
return
}
delete(byDiscoKeys, done.work.discoKeys)
if len(byDiscoKeys) == 0 {
delete(r.allocWorkByDiscoKeysByServerNodeKey, done.work.candidatePeerRelay.nodeKey)
}
if !done.allocated.ServerDisco.IsZero() {
r.handleNewServerEndpointRunLoop(newRelayServerEndpointEvent{
wlb: done.work.wlb,
se: done.allocated,
server: done.work.candidatePeerRelay,
})
}
}
func (r *relayManager) handleHandshakeWorkDoneRunLoop(done relayEndpointHandshakeWorkDoneEvent) {
byServerDisco, ok := r.handshakeWorkByEndpointByServerDisco[done.work.wlb.ep]
byServerDisco, ok := r.handshakeWorkByServerDiscoByEndpoint[done.work.wlb.ep]
if !ok {
return
}
@ -515,7 +609,7 @@ func (r *relayManager) handleHandshakeWorkDoneRunLoop(done relayEndpointHandshak
}
delete(byServerDisco, done.work.se.ServerDisco)
if len(byServerDisco) == 0 {
delete(r.handshakeWorkByEndpointByServerDisco, done.work.wlb.ep)
delete(r.handshakeWorkByServerDiscoByEndpoint, done.work.wlb.ep)
}
delete(r.handshakeWorkByServerDiscoVNI, serverDiscoVNI{done.work.se.ServerDisco, done.work.se.VNI})
apv, ok := r.handshakeWorkAwaitingPong[work]
@ -562,7 +656,7 @@ func (r *relayManager) handleNewServerEndpointRunLoop(newServerEndpoint newRelay
}
// Check for duplicate work by [*endpoint] + server disco.
byServerDisco, ok := r.handshakeWorkByEndpointByServerDisco[newServerEndpoint.wlb.ep]
byServerDisco, ok := r.handshakeWorkByServerDiscoByEndpoint[newServerEndpoint.wlb.ep]
if ok {
existingWork, ok := byServerDisco[newServerEndpoint.se.ServerDisco]
if ok {
@ -580,33 +674,9 @@ func (r *relayManager) handleNewServerEndpointRunLoop(newServerEndpoint newRelay
// We're now reasonably sure we're dealing with the latest
// [udprelay.ServerEndpoint] from a server event order perspective
// (LamportID). Update server disco key tracking if appropriate.
if newServerEndpoint.server.IsValid() {
serverDisco, ok := r.serversByAddrPort[newServerEndpoint.server]
if !ok {
// Allocation raced with an update to our known servers set. This
// server is no longer known. Return early.
return
}
if serverDisco.Compare(newServerEndpoint.se.ServerDisco) != 0 {
// The server's disco key has either changed, or simply become
// known for the first time. In the former case we end up detaching
// any in-progress handshake work from a "known" relay server.
// Practically speaking we expect the detached work to fail
// if the server key did in fact change (server restart) while we
// were attempting to handshake with it. It is possible, though
// unlikely, for a server addr:port to effectively move between
// nodes. Either way, there is no harm in detaching existing work,
// and we explicitly let that happen for the rare case the detached
// handshake would complete and remain functional.
delete(r.serversByDisco, serverDisco)
delete(r.serversByAddrPort, newServerEndpoint.server)
r.serversByDisco[serverDisco] = newServerEndpoint.server
r.serversByAddrPort[newServerEndpoint.server] = serverDisco
}
}
// (LamportID).
if newServerEndpoint.server.IsValid() {
if newServerEndpoint.server.isValid() {
// Send a [disco.CallMeMaybeVia] to the remote peer if we allocated this
// endpoint, regardless of if we start a handshake below.
go r.sendCallMeMaybeVia(newServerEndpoint.wlb.ep, newServerEndpoint.se)
@ -641,14 +711,14 @@ func (r *relayManager) handleNewServerEndpointRunLoop(newServerEndpoint newRelay
work := &relayHandshakeWork{
wlb: newServerEndpoint.wlb,
se: newServerEndpoint.se,
rxDiscoMsgCh: make(chan relayHandshakeDiscoMsgEvent),
rxDiscoMsgCh: make(chan relayDiscoMsgEvent),
doneCh: make(chan relayEndpointHandshakeWorkDoneEvent, 1),
ctx: ctx,
cancel: cancel,
}
if byServerDisco == nil {
byServerDisco = make(map[key.DiscoPublic]*relayHandshakeWork)
r.handshakeWorkByEndpointByServerDisco[newServerEndpoint.wlb.ep] = byServerDisco
r.handshakeWorkByServerDiscoByEndpoint[newServerEndpoint.wlb.ep] = byServerDisco
}
byServerDisco[newServerEndpoint.se.ServerDisco] = work
r.handshakeWorkByServerDiscoVNI[sdv] = work
@ -674,12 +744,15 @@ func (r *relayManager) sendCallMeMaybeVia(ep *endpoint, se udprelay.ServerEndpoi
return
}
callMeMaybeVia := &disco.CallMeMaybeVia{
ServerDisco: se.ServerDisco,
LamportID: se.LamportID,
VNI: se.VNI,
BindLifetime: se.BindLifetime.Duration,
SteadyStateLifetime: se.SteadyStateLifetime.Duration,
AddrPorts: se.AddrPorts,
UDPRelayEndpoint: disco.UDPRelayEndpoint{
ServerDisco: se.ServerDisco,
ClientDisco: se.ClientDisco,
LamportID: se.LamportID,
VNI: se.VNI,
BindLifetime: se.BindLifetime.Duration,
SteadyStateLifetime: se.SteadyStateLifetime.Duration,
AddrPorts: se.AddrPorts,
},
}
ep.c.sendDiscoMessage(epAddr{ap: derpAddr}, ep.publicKey, epDisco.key, callMeMaybeVia, discoVerboseLog)
}
@ -800,7 +873,7 @@ func (r *relayManager) handshakeServerEndpoint(work *relayHandshakeWork, generat
// one.
//
// We don't need to TX a pong, that was already handled for us
// in handleRxHandshakeDiscoMsgRunLoop().
// in handleRxDiscoMsgRunLoop().
txPing(msgEvent.from, nil)
case *disco.Pong:
at, ok := sentPingAt[msg.TxID]
@ -823,104 +896,113 @@ func (r *relayManager) handshakeServerEndpoint(work *relayHandshakeWork, generat
}
}
const allocateUDPRelayEndpointRequestTimeout = time.Second * 10
func (r *relayManager) allocateServerEndpoint(work *relayEndpointAllocWork, generation uint32) {
done := relayEndpointAllocWorkDoneEvent{work: work}
defer func() {
work.doneCh <- done
relayManagerInputEvent(r, work.ctx, &r.allocateWorkDoneCh, done)
work.cancel()
}()
dm := &disco.AllocateUDPRelayEndpointRequest{
ClientDisco: work.discoKeys.Get(),
Generation: generation,
}
sendAllocReq := func() {
work.wlb.ep.c.sendDiscoAllocateUDPRelayEndpointRequest(
epAddr{
ap: netip.AddrPortFrom(tailcfg.DerpMagicIPAddr, work.candidatePeerRelay.derpHomeRegionID),
},
work.candidatePeerRelay.nodeKey,
work.candidatePeerRelay.discoKey,
dm,
discoVerboseLog,
)
}
go sendAllocReq()
returnAfterTimer := time.NewTimer(allocateUDPRelayEndpointRequestTimeout)
defer returnAfterTimer.Stop()
// While connections to DERP are over TCP, they can be lossy on the DERP
// server when data moves between the two independent streams. Also, the
// peer relay server may not be "ready" (see [tailscale.com/net/udprelay.ErrServerNotReady]).
// So, start a timer to retry once if needed.
retryAfterTimer := time.NewTimer(udprelay.ServerRetryAfter)
defer retryAfterTimer.Stop()
for {
select {
case <-work.ctx.Done():
return
case <-returnAfterTimer.C:
return
case <-retryAfterTimer.C:
go sendAllocReq()
case resp := <-work.rxDiscoMsgCh:
if resp.Generation != generation ||
!work.discoKeys.Equal(key.NewSortedPairOfDiscoPublic(resp.ClientDisco[0], resp.ClientDisco[1])) {
continue
}
done.allocated = udprelay.ServerEndpoint{
ServerDisco: resp.ServerDisco,
ClientDisco: resp.ClientDisco,
LamportID: resp.LamportID,
AddrPorts: resp.AddrPorts,
VNI: resp.VNI,
BindLifetime: tstime.GoDuration{Duration: resp.BindLifetime},
SteadyStateLifetime: tstime.GoDuration{Duration: resp.SteadyStateLifetime},
}
return
}
}
}
func (r *relayManager) allocateAllServersRunLoop(wlb endpointWithLastBest) {
if len(r.serversByAddrPort) == 0 {
if len(r.serversByNodeKey) == 0 {
return
}
ctx, cancel := context.WithCancel(context.Background())
started := &relayEndpointAllocWork{ep: wlb.ep, cancel: cancel, wg: &sync.WaitGroup{}}
for k := range r.serversByAddrPort {
started.wg.Add(1)
go r.allocateSingleServer(ctx, started.wg, k, wlb)
}
r.allocWorkByEndpoint[wlb.ep] = started
go func() {
started.wg.Wait()
relayManagerInputEvent(r, ctx, &r.allocateWorkDoneCh, relayEndpointAllocWorkDoneEvent{work: started})
// cleanup context cancellation must come after the
// relayManagerInputEvent call, otherwise it returns early without
// writing the event to runLoop().
started.cancel()
}()
}
type errNotReady struct{ retryAfter time.Duration }
func (e errNotReady) Error() string {
return fmt.Sprintf("server not ready, retry after %v", e.retryAfter)
}
const reqTimeout = time.Second * 10
func doAllocate(ctx context.Context, server netip.AddrPort, discoKeys [2]key.DiscoPublic) (udprelay.ServerEndpoint, error) {
var reqBody bytes.Buffer
type allocateRelayEndpointReq struct {
DiscoKeys []key.DiscoPublic
}
a := &allocateRelayEndpointReq{
DiscoKeys: []key.DiscoPublic{discoKeys[0], discoKeys[1]},
}
err := json.NewEncoder(&reqBody).Encode(a)
if err != nil {
return udprelay.ServerEndpoint{}, err
}
reqCtx, cancel := context.WithTimeout(ctx, reqTimeout)
defer cancel()
req, err := http.NewRequestWithContext(reqCtx, httpm.POST, "http://"+server.String()+"/v0/relay/endpoint", &reqBody)
if err != nil {
return udprelay.ServerEndpoint{}, err
}
resp, err := http.DefaultClient.Do(req)
if err != nil {
return udprelay.ServerEndpoint{}, err
}
defer resp.Body.Close()
switch resp.StatusCode {
case http.StatusOK:
var se udprelay.ServerEndpoint
err = json.NewDecoder(io.LimitReader(resp.Body, 4096)).Decode(&se)
return se, err
case http.StatusServiceUnavailable:
raHeader := resp.Header.Get("Retry-After")
raSeconds, err := strconv.ParseUint(raHeader, 10, 32)
if err == nil {
return udprelay.ServerEndpoint{}, errNotReady{retryAfter: time.Second * time.Duration(raSeconds)}
}
fallthrough
default:
return udprelay.ServerEndpoint{}, fmt.Errorf("non-200 status: %d", resp.StatusCode)
}
}
func (r *relayManager) allocateSingleServer(ctx context.Context, wg *sync.WaitGroup, server netip.AddrPort, wlb endpointWithLastBest) {
// TODO(jwhited): introduce client metrics counters for notable failures
defer wg.Done()
remoteDisco := wlb.ep.disco.Load()
if remoteDisco == nil {
return
}
firstTry := true
for {
se, err := doAllocate(ctx, server, [2]key.DiscoPublic{wlb.ep.c.discoPublic, remoteDisco.key})
if err == nil {
relayManagerInputEvent(r, ctx, &r.newServerEndpointCh, newRelayServerEndpointEvent{
wlb: wlb,
se: se,
server: server, // we allocated this endpoint (vs CallMeMaybeVia reception), mark it as such
})
return
}
wlb.ep.c.logf("[v1] magicsock: relayManager: error allocating endpoint on %v for %v: %v", server, wlb.ep.discoShort(), err)
var notReady errNotReady
if firstTry && errors.As(err, &notReady) {
select {
case <-ctx.Done():
return
case <-time.After(min(notReady.retryAfter, reqTimeout)):
firstTry = false
discoKeys := key.NewSortedPairOfDiscoPublic(wlb.ep.c.discoPublic, remoteDisco.key)
for _, v := range r.serversByNodeKey {
byDiscoKeys, ok := r.allocWorkByDiscoKeysByServerNodeKey[v.nodeKey]
if !ok {
byDiscoKeys = make(map[key.SortedPairOfDiscoPublic]*relayEndpointAllocWork)
r.allocWorkByDiscoKeysByServerNodeKey[v.nodeKey] = byDiscoKeys
} else {
_, ok = byDiscoKeys[discoKeys]
if ok {
// If there is an existing key, a disco key collision may have
// occurred across peers ([*endpoint]). Do not overwrite the
// existing work, let it finish.
wlb.ep.c.logf("[unexpected] magicsock: relayManager: suspected disco key collision on server %v for keys: %v", v.nodeKey.ShortString(), discoKeys)
continue
}
}
return
ctx, cancel := context.WithCancel(context.Background())
started := &relayEndpointAllocWork{
wlb: wlb,
discoKeys: discoKeys,
candidatePeerRelay: v,
rxDiscoMsgCh: make(chan *disco.AllocateUDPRelayEndpointResponse),
doneCh: make(chan relayEndpointAllocWorkDoneEvent, 1),
ctx: ctx,
cancel: cancel,
}
byDiscoKeys[discoKeys] = started
byCandidatePeerRelay, ok := r.allocWorkByCandidatePeerRelayByEndpoint[wlb.ep]
if !ok {
byCandidatePeerRelay = make(map[candidatePeerRelay]*relayEndpointAllocWork)
r.allocWorkByCandidatePeerRelayByEndpoint[wlb.ep] = byCandidatePeerRelay
}
byCandidatePeerRelay[v] = started
r.allocGeneration++
go r.allocateServerEndpoint(started, r.allocGeneration)
}
}

42
wgengine/magicsock/relaymanager_test.go
View File

@ -4,7 +4,6 @@
package magicsock
import (
"net/netip"
"testing"
"tailscale.com/disco"
@ -22,26 +21,57 @@ func TestRelayManagerInitAndIdle(t *testing.T) {
<-rm.runLoopStoppedCh
rm = relayManager{}
rm.handleCallMeMaybeVia(&endpoint{c: &Conn{discoPrivate: key.NewDisco()}}, addrQuality{}, false, &disco.CallMeMaybeVia{ServerDisco: key.NewDisco().Public()})
rm.handleCallMeMaybeVia(&endpoint{c: &Conn{discoPrivate: key.NewDisco()}}, addrQuality{}, false, &disco.CallMeMaybeVia{UDPRelayEndpoint: disco.UDPRelayEndpoint{ServerDisco: key.NewDisco().Public()}})
<-rm.runLoopStoppedCh
rm = relayManager{}
rm.handleGeneveEncapDiscoMsg(&Conn{discoPrivate: key.NewDisco()}, &disco.BindUDPRelayEndpointChallenge{}, &discoInfo{}, epAddr{})
rm.handleRxDiscoMsg(&Conn{discoPrivate: key.NewDisco()}, &disco.BindUDPRelayEndpointChallenge{}, key.NodePublic{}, key.DiscoPublic{}, epAddr{})
<-rm.runLoopStoppedCh
rm = relayManager{}
rm.handleRelayServersSet(make(set.Set[netip.AddrPort]))
rm.handleRelayServersSet(make(set.Set[candidatePeerRelay]))
<-rm.runLoopStoppedCh
rm = relayManager{}
rm.getServers()
<-rm.runLoopStoppedCh
rm = relayManager{}
rm.handleDERPHomeChange(key.NodePublic{}, 1)
<-rm.runLoopStoppedCh
}
func TestRelayManagerHandleDERPHomeChange(t *testing.T) {
rm := relayManager{}
servers := make(set.Set[candidatePeerRelay], 1)
c := candidatePeerRelay{
nodeKey: key.NewNode().Public(),
discoKey: key.NewDisco().Public(),
derpHomeRegionID: 1,
}
servers.Add(c)
rm.handleRelayServersSet(servers)
want := c
want.derpHomeRegionID = 2
rm.handleDERPHomeChange(c.nodeKey, 2)
got := rm.getServers()
if len(got) != 1 {
t.Fatalf("got %d servers, want 1", len(got))
}
_, ok := got[want]
if !ok {
t.Fatal("DERP home change failed to propagate")
}
}
func TestRelayManagerGetServers(t *testing.T) {
rm := relayManager{}
servers := make(set.Set[netip.AddrPort], 1)
servers.Add(netip.MustParseAddrPort("192.0.2.1:7"))
servers := make(set.Set[candidatePeerRelay], 1)
c := candidatePeerRelay{
nodeKey: key.NewNode().Public(),
discoKey: key.NewDisco().Public(),
}
servers.Add(c)
rm.handleRelayServersSet(servers)
got := rm.getServers()
if !servers.Equal(got) {