add tunnel feature for relay

handler/relay/tunnel.go

@@ -0,0 +1,149 @@
+package relay
+
+import (
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/go-gost/core/logger"
+	"github.com/go-gost/relay"
+	"github.com/go-gost/x/internal/util/mux"
+)
+
+type Connector struct {
+	id relay.ConnectorID
+	t  time.Time
+	s  *mux.Session
+}
+
+func NewConnector(id relay.ConnectorID, s *mux.Session) *Connector {
+	c := &Connector{
+		id: id,
+		t:  time.Now(),
+		s:  s,
+	}
+	go c.accept()
+	return c
+}
+
+func (c *Connector) accept() {
+	for {
+		conn, err := c.s.Accept()
+		if err != nil {
+			logger.Default().Errorf("connector %s: %v", c.id, err)
+			c.s.Close()
+			return
+		}
+		conn.Close()
+	}
+}
+
+func (c *Connector) ID() relay.ConnectorID {
+	return c.id
+}
+
+func (c *Connector) Session() *mux.Session {
+	return c.s
+}
+
+type Tunnel struct {
+	id         relay.TunnelID
+	connectors []*Connector
+	t          time.Time
+	n          uint64
+	mu         sync.RWMutex
+}
+
+func NewTunnel(id relay.TunnelID) *Tunnel {
+	t := &Tunnel{
+		id: id,
+		t:  time.Now(),
+	}
+	go t.clean()
+	return t
+}
+
+func (t *Tunnel) ID() relay.TunnelID {
+	return t.id
+}
+
+func (t *Tunnel) AddConnector(c *Connector) {
+	if c == nil {
+		return
+	}
+
+	t.mu.Lock()
+	defer t.mu.Unlock()
+
+	t.connectors = append(t.connectors, c)
+}
+
+func (t *Tunnel) GetConnector() *Connector {
+	t.mu.RLock()
+	defer t.mu.RUnlock()
+
+	if len(t.connectors) == 0 {
+		return nil
+	}
+
+	n := atomic.AddUint64(&t.n, 1) - 1
+	return t.connectors[n%uint64(len(t.connectors))]
+}
+
+func (t *Tunnel) clean() {
+	ticker := time.NewTicker(3 * time.Second)
+	for range ticker.C {
+		t.mu.Lock()
+		var connectors []*Connector
+		for _, c := range t.connectors {
+			if c.Session().IsClosed() {
+				logger.Default().Debugf("remove tunnel %s connector %s", t.id, c.id)
+				continue
+			}
+			connectors = append(connectors, c)
+		}
+		if len(connectors) != len(t.connectors) {
+			t.connectors = connectors
+		}
+		t.mu.Unlock()
+	}
+}
+
+type ConnectorPool struct {
+	tunnels map[relay.TunnelID]*Tunnel
+	mu      sync.RWMutex
+}
+
+func NewConnectorPool() *ConnectorPool {
+	return &ConnectorPool{
+		tunnels: make(map[relay.TunnelID]*Tunnel),
+	}
+}
+
+func (p *ConnectorPool) Add(tid relay.TunnelID, c *Connector) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+
+	t := p.tunnels[tid]
+	if t == nil {
+		t = NewTunnel(tid)
+		p.tunnels[tid] = t
+	}
+	t.AddConnector(c)
+}
+
+func (p *ConnectorPool) Get(tid relay.TunnelID) *Connector {
+	if p == nil {
+		return nil
+	}
+
+	p.mu.RLock()
+	defer p.mu.RUnlock()
+
+	t := p.tunnels[tid]
+	if t == nil {
+		return nil
+	}
+
+	return t.GetConnector()
+}