status-go/vendor/github.com/pion/turn/v2/client.go

570 lines
15 KiB
Go

package turn
import (
b64 "encoding/base64"
"fmt"
"math"
"net"
"sync"
"time"
"github.com/pion/logging"
"github.com/pion/stun"
"github.com/pion/transport/vnet"
"github.com/pion/turn/v2/internal/client"
"github.com/pion/turn/v2/internal/proto"
)
const (
defaultRTO = 200 * time.Millisecond
maxRtxCount = 7 // total 7 requests (Rc)
maxDataBufferSize = math.MaxUint16 // message size limit for Chromium
)
// interval [msec]
// 0: 0 ms +500
// 1: 500 ms +1000
// 2: 1500 ms +2000
// 3: 3500 ms +4000
// 4: 7500 ms +8000
// 5: 15500 ms +16000
// 6: 31500 ms +32000
// -: 63500 ms failed
// ClientConfig is a bag of config parameters for Client.
type ClientConfig struct {
STUNServerAddr string // STUN server address (e.g. "stun.abc.com:3478")
TURNServerAddr string // TURN server addrees (e.g. "turn.abc.com:3478")
Username string
Password string
Realm string
Software string
RTO time.Duration
Conn net.PacketConn // Listening socket (net.PacketConn)
LoggerFactory logging.LoggerFactory
Net *vnet.Net
}
// Client is a STUN server client
type Client struct {
conn net.PacketConn // read-only
stunServ net.Addr // read-only
turnServ net.Addr // read-only
stunServStr string // read-only, used for dmuxing
turnServStr string // read-only, used for dmuxing
username stun.Username // read-only
password string // read-only
realm stun.Realm // read-only
integrity stun.MessageIntegrity // read-only
software stun.Software // read-only
trMap *client.TransactionMap // thread-safe
rto time.Duration // read-only
relayedConn *client.UDPConn // protected by mutex ***
allocTryLock client.TryLock // thread-safe
listenTryLock client.TryLock // thread-safe
net *vnet.Net // read-only
mutex sync.RWMutex // thread-safe
mutexTrMap sync.Mutex // thread-safe
log logging.LeveledLogger // read-only
}
// NewClient returns a new Client instance. listeningAddress is the address and port to listen on, default "0.0.0.0:0"
func NewClient(config *ClientConfig) (*Client, error) {
loggerFactory := config.LoggerFactory
if loggerFactory == nil {
loggerFactory = logging.NewDefaultLoggerFactory()
}
log := loggerFactory.NewLogger("turnc")
if config.Conn == nil {
return nil, errNilConn
}
if config.Net == nil {
config.Net = vnet.NewNet(nil) // defaults to native operation
} else if config.Net.IsVirtual() {
log.Warn("vnet is enabled")
}
var stunServ, turnServ net.Addr
var stunServStr, turnServStr string
var err error
if len(config.STUNServerAddr) > 0 {
log.Debugf("resolving %s", config.STUNServerAddr)
stunServ, err = config.Net.ResolveUDPAddr("udp4", config.STUNServerAddr)
if err != nil {
return nil, err
}
stunServStr = stunServ.String()
log.Debugf("stunServ: %s", stunServStr)
}
if len(config.TURNServerAddr) > 0 {
log.Debugf("resolving %s", config.TURNServerAddr)
turnServ, err = config.Net.ResolveUDPAddr("udp4", config.TURNServerAddr)
if err != nil {
return nil, err
}
turnServStr = turnServ.String()
log.Debugf("turnServ: %s", turnServStr)
}
rto := defaultRTO
if config.RTO > 0 {
rto = config.RTO
}
c := &Client{
conn: config.Conn,
stunServ: stunServ,
turnServ: turnServ,
stunServStr: stunServStr,
turnServStr: turnServStr,
username: stun.NewUsername(config.Username),
password: config.Password,
realm: stun.NewRealm(config.Realm),
software: stun.NewSoftware(config.Software),
net: config.Net,
trMap: client.NewTransactionMap(),
rto: rto,
log: log,
}
return c, nil
}
// TURNServerAddr return the TURN server address
func (c *Client) TURNServerAddr() net.Addr {
return c.turnServ
}
// STUNServerAddr return the STUN server address
func (c *Client) STUNServerAddr() net.Addr {
return c.stunServ
}
// Username returns username
func (c *Client) Username() stun.Username {
return c.username
}
// Realm return realm
func (c *Client) Realm() stun.Realm {
return c.realm
}
// WriteTo sends data to the specified destination using the base socket.
func (c *Client) WriteTo(data []byte, to net.Addr) (int, error) {
return c.conn.WriteTo(data, to)
}
// Listen will have this client start listening on the conn provided via the config.
// This is optional. If not used, you will need to call HandleInbound method
// to supply incoming data, instead.
func (c *Client) Listen() error {
if err := c.listenTryLock.Lock(); err != nil {
return fmt.Errorf("%w: %s", errAlreadyListening, err.Error())
}
go func() {
buf := make([]byte, maxDataBufferSize)
for {
n, from, err := c.conn.ReadFrom(buf)
if err != nil {
c.log.Debugf("exiting read loop: %s", err.Error())
break
}
_, err = c.HandleInbound(buf[:n], from)
if err != nil {
c.log.Debugf("exiting read loop: %s", err.Error())
break
}
}
c.listenTryLock.Unlock()
}()
return nil
}
// Close closes this client
func (c *Client) Close() {
c.mutexTrMap.Lock()
defer c.mutexTrMap.Unlock()
c.trMap.CloseAndDeleteAll()
}
// TransactionID & Base64: https://play.golang.org/p/EEgmJDI971P
// SendBindingRequestTo sends a new STUN request to the given transport address
func (c *Client) SendBindingRequestTo(to net.Addr) (net.Addr, error) {
attrs := []stun.Setter{stun.TransactionID, stun.BindingRequest}
if len(c.software) > 0 {
attrs = append(attrs, c.software)
}
msg, err := stun.Build(attrs...)
if err != nil {
return nil, err
}
trRes, err := c.PerformTransaction(msg, to, false)
if err != nil {
return nil, err
}
var reflAddr stun.XORMappedAddress
if err := reflAddr.GetFrom(trRes.Msg); err != nil {
return nil, err
}
return &net.UDPAddr{
IP: reflAddr.IP,
Port: reflAddr.Port,
}, nil
}
// SendBindingRequest sends a new STUN request to the STUN server
func (c *Client) SendBindingRequest() (net.Addr, error) {
if c.stunServ == nil {
return nil, errSTUNServerAddressNotSet
}
return c.SendBindingRequestTo(c.stunServ)
}
// Allocate sends a TURN allocation request to the given transport address
func (c *Client) Allocate() (net.PacketConn, error) {
if err := c.allocTryLock.Lock(); err != nil {
return nil, fmt.Errorf("%w: %s", errOneAllocateOnly, err.Error())
}
defer c.allocTryLock.Unlock()
relayedConn := c.relayedUDPConn()
if relayedConn != nil {
return nil, fmt.Errorf("%w: %s", errAlreadyAllocated, relayedConn.LocalAddr().String())
}
msg, err := stun.Build(
stun.TransactionID,
stun.NewType(stun.MethodAllocate, stun.ClassRequest),
proto.RequestedTransport{Protocol: proto.ProtoUDP},
stun.Fingerprint,
)
if err != nil {
return nil, err
}
trRes, err := c.PerformTransaction(msg, c.turnServ, false)
if err != nil {
return nil, err
}
res := trRes.Msg
// Anonymous allocate failed, trying to authenticate.
var nonce stun.Nonce
if err = nonce.GetFrom(res); err != nil {
return nil, err
}
if err = c.realm.GetFrom(res); err != nil {
return nil, err
}
c.realm = append([]byte(nil), c.realm...)
c.integrity = stun.NewLongTermIntegrity(
c.username.String(), c.realm.String(), c.password,
)
// Trying to authorize.
msg, err = stun.Build(
stun.TransactionID,
stun.NewType(stun.MethodAllocate, stun.ClassRequest),
proto.RequestedTransport{Protocol: proto.ProtoUDP},
&c.username,
&c.realm,
&nonce,
&c.integrity,
stun.Fingerprint,
)
if err != nil {
return nil, err
}
trRes, err = c.PerformTransaction(msg, c.turnServ, false)
if err != nil {
return nil, err
}
res = trRes.Msg
if res.Type.Class == stun.ClassErrorResponse {
var code stun.ErrorCodeAttribute
if err = code.GetFrom(res); err == nil {
return nil, fmt.Errorf("%s (error %s)", res.Type, code) //nolint:goerr113
}
return nil, fmt.Errorf("%s", res.Type) //nolint:goerr113
}
// Getting relayed addresses from response.
var relayed proto.RelayedAddress
if err := relayed.GetFrom(res); err != nil {
return nil, err
}
relayedAddr := &net.UDPAddr{
IP: relayed.IP,
Port: relayed.Port,
}
// Getting lifetime from response
var lifetime proto.Lifetime
if err := lifetime.GetFrom(res); err != nil {
return nil, err
}
relayedConn = client.NewUDPConn(&client.UDPConnConfig{
Observer: c,
RelayedAddr: relayedAddr,
Integrity: c.integrity,
Nonce: nonce,
Lifetime: lifetime.Duration,
Log: c.log,
})
c.setRelayedUDPConn(relayedConn)
return relayedConn, nil
}
// PerformTransaction performs STUN transaction
func (c *Client) PerformTransaction(msg *stun.Message, to net.Addr, ignoreResult bool) (client.TransactionResult,
error) {
trKey := b64.StdEncoding.EncodeToString(msg.TransactionID[:])
raw := make([]byte, len(msg.Raw))
copy(raw, msg.Raw)
tr := client.NewTransaction(&client.TransactionConfig{
Key: trKey,
Raw: raw,
To: to,
Interval: c.rto,
IgnoreResult: ignoreResult,
})
c.trMap.Insert(trKey, tr)
c.log.Tracef("start %s transaction %s to %s", msg.Type, trKey, tr.To.String())
_, err := c.conn.WriteTo(tr.Raw, to)
if err != nil {
return client.TransactionResult{}, err
}
tr.StartRtxTimer(c.onRtxTimeout)
// If dontWait is true, get the transaction going and return immediately
if ignoreResult {
return client.TransactionResult{}, nil
}
res := tr.WaitForResult()
if res.Err != nil {
return res, res.Err
}
return res, nil
}
// OnDeallocated is called when deallocation of relay address has been complete.
// (Called by UDPConn)
func (c *Client) OnDeallocated(relayedAddr net.Addr) {
c.setRelayedUDPConn(nil)
}
// HandleInbound handles data received.
// This method handles incoming packet demultiplex it by the source address
// and the types of the message.
// This return a booleen (handled or not) and if there was an error.
// Caller should check if the packet was handled by this client or not.
// If not handled, it is assumed that the packet is application data.
// If an error is returned, the caller should discard the packet regardless.
func (c *Client) HandleInbound(data []byte, from net.Addr) (bool, error) {
// +-------------------+-------------------------------+
// | Return Values | |
// +-------------------+ Meaning / Action |
// | handled | error | |
// |=========+=========+===============================+
// | false | nil | Handle the packet as app data |
// |---------+---------+-------------------------------+
// | true | nil | Nothing to do |
// |---------+---------+-------------------------------+
// | false | error | (shouldn't happen) |
// |---------+---------+-------------------------------+
// | true | error | Error occurred while handling |
// +---------+---------+-------------------------------+
// Possible causes of the error:
// - Malformed packet (parse error)
// - STUN message was a request
// - Non-STUN message from the STUN server
switch {
case stun.IsMessage(data):
return true, c.handleSTUNMessage(data, from)
case proto.IsChannelData(data):
return true, c.handleChannelData(data)
case len(c.stunServStr) != 0 && from.String() == c.stunServStr:
// received from STUN server but it is not a STUN message
return true, errNonSTUNMessage
default:
// assume, this is an application data
c.log.Tracef("non-STUN/TURN packect, unhandled")
}
return false, nil
}
func (c *Client) handleSTUNMessage(data []byte, from net.Addr) error {
raw := make([]byte, len(data))
copy(raw, data)
msg := &stun.Message{Raw: raw}
if err := msg.Decode(); err != nil {
return fmt.Errorf("%w: %s", errFailedToDecodeSTUN, err.Error())
}
if msg.Type.Class == stun.ClassRequest {
return fmt.Errorf("%w : %s", errUnexpectedSTUNRequestMessage, msg.String())
}
if msg.Type.Class == stun.ClassIndication {
if msg.Type.Method == stun.MethodData {
var peerAddr proto.PeerAddress
if err := peerAddr.GetFrom(msg); err != nil {
return err
}
from = &net.UDPAddr{
IP: peerAddr.IP,
Port: peerAddr.Port,
}
var data proto.Data
if err := data.GetFrom(msg); err != nil {
return err
}
c.log.Debugf("data indication received from %s", from.String())
relayedConn := c.relayedUDPConn()
if relayedConn == nil {
c.log.Debug("no relayed conn allocated")
return nil // silently discard
}
relayedConn.HandleInbound(data, from)
}
return nil
}
// This is a STUN response message (transactional)
// The type is either:
// - stun.ClassSuccessResponse
// - stun.ClassErrorResponse
trKey := b64.StdEncoding.EncodeToString(msg.TransactionID[:])
c.mutexTrMap.Lock()
tr, ok := c.trMap.Find(trKey)
if !ok {
c.mutexTrMap.Unlock()
// silently discard
c.log.Debugf("no transaction for %s", msg.String())
return nil
}
// End the transaction
tr.StopRtxTimer()
c.trMap.Delete(trKey)
c.mutexTrMap.Unlock()
if !tr.WriteResult(client.TransactionResult{
Msg: msg,
From: from,
Retries: tr.Retries(),
}) {
c.log.Debugf("no listener for %s", msg.String())
}
return nil
}
func (c *Client) handleChannelData(data []byte) error {
chData := &proto.ChannelData{
Raw: make([]byte, len(data)),
}
copy(chData.Raw, data)
if err := chData.Decode(); err != nil {
return err
}
relayedConn := c.relayedUDPConn()
if relayedConn == nil {
c.log.Debug("no relayed conn allocated")
return nil // silently discard
}
addr, ok := relayedConn.FindAddrByChannelNumber(uint16(chData.Number))
if !ok {
return fmt.Errorf("%w: %d", errChannelBindNotFound, int(chData.Number))
}
c.log.Tracef("channel data received from %s (ch=%d)", addr.String(), int(chData.Number))
relayedConn.HandleInbound(chData.Data, addr)
return nil
}
func (c *Client) onRtxTimeout(trKey string, nRtx int) {
c.mutexTrMap.Lock()
defer c.mutexTrMap.Unlock()
tr, ok := c.trMap.Find(trKey)
if !ok {
return // already gone
}
if nRtx == maxRtxCount {
// all retransmisstions failed
c.trMap.Delete(trKey)
if !tr.WriteResult(client.TransactionResult{
Err: fmt.Errorf("%w %s", errAllRetransmissionsFailed, trKey),
}) {
c.log.Debug("no listener for transaction")
}
return
}
c.log.Tracef("retransmitting transaction %s to %s (nRtx=%d)",
trKey, tr.To.String(), nRtx)
_, err := c.conn.WriteTo(tr.Raw, tr.To)
if err != nil {
c.trMap.Delete(trKey)
if !tr.WriteResult(client.TransactionResult{
Err: fmt.Errorf("%w %s", errFailedToRetransmitTransaction, trKey),
}) {
c.log.Debug("no listener for transaction")
}
return
}
tr.StartRtxTimer(c.onRtxTimeout)
}
func (c *Client) setRelayedUDPConn(conn *client.UDPConn) {
c.mutex.Lock()
defer c.mutex.Unlock()
c.relayedConn = conn
}
func (c *Client) relayedUDPConn() *client.UDPConn {
c.mutex.RLock()
defer c.mutex.RUnlock()
return c.relayedConn
}