func()

in pkg/sshd/ssh.go [263:331]

• 39 lines of code
• 6 McCabe index (conditional complexity)

func (sshGate *Server) HandleServerConn(nConn net.Conn) {
	// Before use, a handshake must be performed on the incoming
	// net.Conn. Handshake results in conn.Permissions.
	conn, chans, globalSrvReqs, err := gossh.NewServerConn(nConn, sshGate.serverConfig)
	if err != nil {
		nConn.Close()
		log.Println("SSHD: handshake error ", err, nConn.RemoteAddr())
		//sshGate.metrics.Errors.Add(1)
		return
	}
	log.Println("SSH connection from ", nConn.RemoteAddr())
	// TODO: track the session, for direct use

	ctx, cancel := context.WithCancel(context.Background())

	defer func() {
		conn.Close()
		cancel()
	}()

	go sshGate.handleServerConnRequests(ctx, globalSrvReqs, nConn, conn)

	// Service the incoming Channel channel.
	// Each channel is a stream - shell, exec, local TCP forward.
	for newChannel := range chans {
		switch newChannel.ChannelType() {
		case "direct-tcpip":
			// When remote starts with a -L PORT:host:port, and connects to port
			var req channelOpenDirectMsg
			//scon.gate.localFwdS.Total.Add(1)
			err := gossh.Unmarshal(newChannel.ExtraData(), &req)
			if err != nil {
				log.Println("malformed-tcpip-request", err)
				newChannel.Reject(gossh.UnknownChannelType, "invalid data")
				continue
			}

			// TODO: allow connections to mesh VIPs
			//if role == ROLE_GUEST &&
			//		req.Rport != SSH_MESH_PORT && req.Rport != H2_MESH_PORT {
			//	newChannel.Reject(ssh.Prohibited,
			//		"only authorized users can proxy " +
			//				scon.VIP6.String())
			//	continue
			//}
			//log.Println("-L: forward request", req.Laddr, req.Lport, req.Raddr, req.Rport, role)

			go DirectTCPIPHandler(ctx, sshGate, conn, newChannel)
			//scon.handleDirectTcpip(newChannel, req.Raddr, req.Rport, req.Laddr, req.Lport)
			//conId++

		case "session":
			// session channel - the main interface for shell, exec
			ch, reqs, _ := newChannel.Accept()
			// Used for messages.
			s := &session{
				Channel: ch,
				conn:    conn,
				srv:     sshGate,
			}
			go s.handleRequests(reqs)

		default:
			fmt.Println("SSHD: unknown channel Rejected", newChannel.ChannelType())
			newChannel.Reject(gossh.UnknownChannelType, "unknown channel type")
		}
	}

}