初步支持 DTLS 通道

server/handler/link_dtls.go

@@ -0,0 +1,103 @@
+package handler
+
+import (
+	"net"
+	"time"
+
+	"github.com/bjdgyc/anylink/base"
+	"github.com/bjdgyc/anylink/sessdata"
+)
+
+func LinkDtls(conn net.Conn, cSess *sessdata.ConnSession) {
+	defer func() {
+		base.Debug("LinkDtls return", cSess.IpAddr)
+		_ = conn.Close()
+		cSess.Close()
+	}()
+
+	var (
+		dead = time.Duration(cSess.CstpDpd+5) * time.Second
+	)
+
+	go dtlsWrite(conn, cSess)
+
+	for {
+		err := conn.SetReadDeadline(time.Now().Add(dead))
+		if err != nil {
+			base.Error("SetDeadline: ", err)
+			return
+		}
+		hdata := make([]byte, BufferSize)
+		n, err := conn.Read(hdata)
+		if err != nil {
+			base.Error("read hdata: ", err)
+			return
+		}
+
+		// 限流设置
+		err = cSess.RateLimit(n, true)
+		if err != nil {
+			base.Error(err)
+		}
+
+		switch hdata[0] {
+		case 0x07: // KEEPALIVE
+			// do nothing
+			base.Debug("recv keepalive", cSess.IpAddr)
+		case 0x05: // DISCONNECT
+			base.Debug("DISCONNECT", cSess.IpAddr)
+			return
+		case 0x03: // DPD-REQ
+			base.Debug("recv DPD-REQ", cSess.IpAddr)
+			if payloadOut(cSess, sessdata.LTypeIPData, 0x04, nil) {
+				return
+			}
+		case 0x04:
+			base.Debug("recv DPD-RESP", cSess.IpAddr)
+		case 0x00: // DATA
+			if payloadIn(cSess, sessdata.LTypeIPData, 0x00, hdata[1:]) {
+				return
+			}
+
+		}
+	}
+}
+
+func dtlsWrite(conn net.Conn, cSess *sessdata.ConnSession) {
+	defer func() {
+		base.Debug("dtlsWrite return", cSess.IpAddr)
+		_ = conn.Close()
+		cSess.Close()
+	}()
+
+	var (
+		header  []byte
+		payload *sessdata.Payload
+	)
+
+	for {
+		select {
+		case payload = <-cSess.PayloadOut:
+		case <-cSess.CloseChan:
+			return
+		}
+
+		if payload.LType != sessdata.LTypeIPData {
+			continue
+		}
+
+		header = []byte{payload.PType}
+		header = append(header, payload.Data...)
+		n, err := conn.Write(header)
+		if err != nil {
+			base.Error("write err", err)
+			return
+		}
+
+		// 限流设置
+		err = cSess.RateLimit(n, false)
+		if err != nil {
+			base.Error(err)
+		}
+	}
+}