netbird/client/internal/peer/worker_ice.go
2024-10-29 16:01:57 +01:00

385 lines
11 KiB
Go

package peer
import (
"context"
"fmt"
"net"
"net/netip"
"sync"
"time"
"github.com/pion/ice/v3"
"github.com/pion/stun/v2"
log "github.com/sirupsen/logrus"
"github.com/netbirdio/netbird/client/iface"
"github.com/netbirdio/netbird/client/iface/bind"
icemaker "github.com/netbirdio/netbird/client/internal/peer/ice"
"github.com/netbirdio/netbird/client/internal/stdnet"
"github.com/netbirdio/netbird/route"
)
type ICEConnInfo struct {
RemoteConn net.Conn
RosenpassPubKey []byte
RosenpassAddr string
LocalIceCandidateType string
RemoteIceCandidateType string
RemoteIceCandidateEndpoint string
LocalIceCandidateEndpoint string
Relayed bool
RelayedOnLocal bool
}
type WorkerICECallbacks struct {
OnConnReady func(ConnPriority, ICEConnInfo)
OnStatusChanged func(ConnStatus)
}
type WorkerICE struct {
ctx context.Context
log *log.Entry
config ConnConfig
signaler *Signaler
iFaceDiscover stdnet.ExternalIFaceDiscover
statusRecorder *Status
hasRelayOnLocally bool
conn WorkerICECallbacks
agent *ice.Agent
muxAgent sync.Mutex
StunTurn []*stun.URI
sentExtraSrflx bool
localUfrag string
localPwd string
}
func NewWorkerICE(ctx context.Context, log *log.Entry, config ConnConfig, signaler *Signaler, ifaceDiscover stdnet.ExternalIFaceDiscover, statusRecorder *Status, hasRelayOnLocally bool, callBacks WorkerICECallbacks) (*WorkerICE, error) {
w := &WorkerICE{
ctx: ctx,
log: log,
config: config,
signaler: signaler,
iFaceDiscover: ifaceDiscover,
statusRecorder: statusRecorder,
hasRelayOnLocally: hasRelayOnLocally,
conn: callBacks,
}
localUfrag, localPwd, err := icemaker.GenerateICECredentials()
if err != nil {
return nil, err
}
w.localUfrag = localUfrag
w.localPwd = localPwd
return w, nil
}
func (w *WorkerICE) OnNewOffer(remoteOfferAnswer *OfferAnswer) {
w.log.Debugf("OnNewOffer for ICE")
w.muxAgent.Lock()
if w.agent != nil {
w.log.Debugf("agent already exists, skipping the offer")
w.muxAgent.Unlock()
return
}
var preferredCandidateTypes []ice.CandidateType
if w.hasRelayOnLocally && remoteOfferAnswer.RelaySrvAddress != "" {
preferredCandidateTypes = icemaker.CandidateTypesP2P()
} else {
preferredCandidateTypes = icemaker.CandidateTypes()
}
w.log.Debugf("recreate ICE agent")
agentCtx, agentCancel := context.WithCancel(w.ctx)
agent, err := w.reCreateAgent(agentCancel, preferredCandidateTypes)
if err != nil {
w.log.Errorf("failed to recreate ICE Agent: %s", err)
w.muxAgent.Unlock()
return
}
w.agent = agent
w.muxAgent.Unlock()
w.log.Debugf("gather candidates")
err = w.agent.GatherCandidates()
if err != nil {
w.log.Debugf("failed to gather candidates: %s", err)
return
}
// will block until connection succeeded
// but it won't release if ICE Agent went into Disconnected or Failed state,
// so we have to cancel it with the provided context once agent detected a broken connection
w.log.Debugf("turn agent dial")
remoteConn, err := w.turnAgentDial(agentCtx, remoteOfferAnswer)
if err != nil {
w.log.Debugf("failed to dial the remote peer: %s", err)
return
}
w.log.Debugf("agent dial succeeded")
pair, err := w.agent.GetSelectedCandidatePair()
if err != nil {
return
}
if !isRelayCandidate(pair.Local) {
// dynamically set remote WireGuard port if other side specified a different one from the default one
remoteWgPort := iface.DefaultWgPort
if remoteOfferAnswer.WgListenPort != 0 {
remoteWgPort = remoteOfferAnswer.WgListenPort
}
// To support old version's with direct mode we attempt to punch an additional role with the remote WireGuard port
go w.punchRemoteWGPort(pair, remoteWgPort)
}
ci := ICEConnInfo{
RemoteConn: remoteConn,
RosenpassPubKey: remoteOfferAnswer.RosenpassPubKey,
RosenpassAddr: remoteOfferAnswer.RosenpassAddr,
LocalIceCandidateType: pair.Local.Type().String(),
RemoteIceCandidateType: pair.Remote.Type().String(),
LocalIceCandidateEndpoint: fmt.Sprintf("%s:%d", pair.Local.Address(), pair.Local.Port()),
RemoteIceCandidateEndpoint: fmt.Sprintf("%s:%d", pair.Remote.Address(), pair.Remote.Port()),
Relayed: isRelayed(pair),
RelayedOnLocal: isRelayCandidate(pair.Local),
}
w.log.Debugf("on ICE conn read to use ready")
go w.conn.OnConnReady(selectedPriority(pair), ci)
}
// OnRemoteCandidate Handles ICE connection Candidate provided by the remote peer.
func (w *WorkerICE) OnRemoteCandidate(candidate ice.Candidate, haRoutes route.HAMap) {
w.muxAgent.Lock()
defer w.muxAgent.Unlock()
w.log.Debugf("OnRemoteCandidate from peer %s -> %s", w.config.Key, candidate.String())
if w.agent == nil {
w.log.Warnf("ICE Agent is not initialized yet")
return
}
if candidateViaRoutes(candidate, haRoutes) {
return
}
err := w.agent.AddRemoteCandidate(candidate)
if err != nil {
w.log.Errorf("error while handling remote candidate")
return
}
}
func (w *WorkerICE) GetLocalUserCredentials() (frag string, pwd string) {
w.muxAgent.Lock()
defer w.muxAgent.Unlock()
return w.localUfrag, w.localPwd
}
func (w *WorkerICE) Close() {
w.muxAgent.Lock()
defer w.muxAgent.Unlock()
if w.agent == nil {
return
}
err := w.agent.Close()
if err != nil {
w.log.Warnf("failed to close ICE agent: %s", err)
}
}
func (w *WorkerICE) reCreateAgent(agentCancel context.CancelFunc, candidates []ice.CandidateType) (*ice.Agent, error) {
w.sentExtraSrflx = false
agent, err := icemaker.NewAgent(w.iFaceDiscover, w.config.ICEConfig, candidates, w.localUfrag, w.localPwd)
if err != nil {
return nil, fmt.Errorf("create agent: %w", err)
}
err = agent.OnCandidate(w.onICECandidate)
if err != nil {
return nil, err
}
err = agent.OnConnectionStateChange(func(state ice.ConnectionState) {
w.log.Debugf("ICE ConnectionState has changed to %s", state.String())
if state == ice.ConnectionStateFailed || state == ice.ConnectionStateDisconnected {
w.conn.OnStatusChanged(StatusDisconnected)
w.muxAgent.Lock()
agentCancel()
_ = agent.Close()
w.agent = nil
w.muxAgent.Unlock()
}
})
if err != nil {
return nil, err
}
err = agent.OnSelectedCandidatePairChange(w.onICESelectedCandidatePair)
if err != nil {
return nil, err
}
err = agent.OnSuccessfulSelectedPairBindingResponse(func(p *ice.CandidatePair) {
err := w.statusRecorder.UpdateLatency(w.config.Key, p.Latency())
if err != nil {
w.log.Debugf("failed to update latency for peer: %s", err)
return
}
})
if err != nil {
return nil, fmt.Errorf("failed setting binding response callback: %w", err)
}
return agent, nil
}
func (w *WorkerICE) punchRemoteWGPort(pair *ice.CandidatePair, remoteWgPort int) {
// wait local endpoint configuration
time.Sleep(time.Second)
addr, err := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", pair.Remote.Address(), remoteWgPort))
if err != nil {
w.log.Warnf("got an error while resolving the udp address, err: %s", err)
return
}
mux, ok := w.config.ICEConfig.UDPMuxSrflx.(*bind.UniversalUDPMuxDefault)
if !ok {
w.log.Warn("invalid udp mux conversion")
return
}
_, err = mux.GetSharedConn().WriteTo([]byte{0x6e, 0x62}, addr)
if err != nil {
w.log.Warnf("got an error while sending the punch packet, err: %s", err)
}
}
// onICECandidate is a callback attached to an ICE Agent to receive new local connection candidates
// and then signals them to the remote peer
func (w *WorkerICE) onICECandidate(candidate ice.Candidate) {
// nil means candidate gathering has been ended
if candidate == nil {
return
}
// TODO: reported port is incorrect for CandidateTypeHost, makes understanding ICE use via logs confusing as port is ignored
w.log.Debugf("discovered local candidate %s", candidate.String())
go func() {
err := w.signaler.SignalICECandidate(candidate, w.config.Key)
if err != nil {
w.log.Errorf("failed signaling candidate to the remote peer %s %s", w.config.Key, err)
}
}()
if !w.shouldSendExtraSrflxCandidate(candidate) {
return
}
// sends an extra server reflexive candidate to the remote peer with our related port (usually the wireguard port)
// this is useful when network has an existing port forwarding rule for the wireguard port and this peer
extraSrflx, err := extraSrflxCandidate(candidate)
if err != nil {
w.log.Errorf("failed creating extra server reflexive candidate %s", err)
return
}
w.sentExtraSrflx = true
go func() {
err = w.signaler.SignalICECandidate(extraSrflx, w.config.Key)
if err != nil {
w.log.Errorf("failed signaling the extra server reflexive candidate: %s", err)
}
}()
}
func (w *WorkerICE) onICESelectedCandidatePair(c1 ice.Candidate, c2 ice.Candidate) {
w.log.Debugf("selected candidate pair [local <-> remote] -> [%s <-> %s], peer %s", c1.String(), c2.String(),
w.config.Key)
}
func (w *WorkerICE) shouldSendExtraSrflxCandidate(candidate ice.Candidate) bool {
if !w.sentExtraSrflx && candidate.Type() == ice.CandidateTypeServerReflexive && candidate.Port() != candidate.RelatedAddress().Port {
return true
}
return false
}
func (w *WorkerICE) turnAgentDial(ctx context.Context, remoteOfferAnswer *OfferAnswer) (*ice.Conn, error) {
isControlling := w.config.LocalKey > w.config.Key
if isControlling {
return w.agent.Dial(ctx, remoteOfferAnswer.IceCredentials.UFrag, remoteOfferAnswer.IceCredentials.Pwd)
} else {
return w.agent.Accept(ctx, remoteOfferAnswer.IceCredentials.UFrag, remoteOfferAnswer.IceCredentials.Pwd)
}
}
func extraSrflxCandidate(candidate ice.Candidate) (*ice.CandidateServerReflexive, error) {
relatedAdd := candidate.RelatedAddress()
return ice.NewCandidateServerReflexive(&ice.CandidateServerReflexiveConfig{
Network: candidate.NetworkType().String(),
Address: candidate.Address(),
Port: relatedAdd.Port,
Component: candidate.Component(),
RelAddr: relatedAdd.Address,
RelPort: relatedAdd.Port,
})
}
func candidateViaRoutes(candidate ice.Candidate, clientRoutes route.HAMap) bool {
var routePrefixes []netip.Prefix
for _, routes := range clientRoutes {
if len(routes) > 0 && routes[0] != nil {
routePrefixes = append(routePrefixes, routes[0].Network)
}
}
addr, err := netip.ParseAddr(candidate.Address())
if err != nil {
log.Errorf("Failed to parse IP address %s: %v", candidate.Address(), err)
return false
}
for _, prefix := range routePrefixes {
// default route is
if prefix.Bits() == 0 {
continue
}
if prefix.Contains(addr) {
log.Debugf("Ignoring candidate [%s], its address is part of routed network %s", candidate.String(), prefix)
return true
}
}
return false
}
func isRelayCandidate(candidate ice.Candidate) bool {
return candidate.Type() == ice.CandidateTypeRelay
}
func isRelayed(pair *ice.CandidatePair) bool {
if pair.Local.Type() == ice.CandidateTypeRelay || pair.Remote.Type() == ice.CandidateTypeRelay {
return true
}
return false
}
func selectedPriority(pair *ice.CandidatePair) ConnPriority {
if isRelayed(pair) {
return connPriorityICETurn
} else {
return connPriorityICEP2P
}
}