docs: http-lp forwarding goes over the agent's WebSocket, by long polls only without one - said so in the panel, the code and the README

internal/agent/session.go

@@ -33,7 +33,8 @@ func (a *Agent) runTerminal(parent context.Context, sid, user, dir string) {
 }
 
 // runForward dials 127.0.0.1:port on the client and bridges it to the session,
-// giving the host a reverse TCP tunnel over the same long-poll transport.
+// giving the host a reverse TCP tunnel over the agent's link to the server:
+// the WebSocket, or the long polls without one.
 func (a *Agent) runForward(parent context.Context, sid string, port int) {
 	d := net.Dialer{Timeout: 10 * time.Second}
 	conn, err := d.DialContext(parent, "tcp", net.JoinHostPort("127.0.0.1", strconv.Itoa(port)))
@@ -92,7 +93,8 @@ func (a *Agent) bridgeStream(parent context.Context, sid string, rw io.ReadWrite
 	}
 }
 
-// pollIn performs one downstream long-poll and applies the frames.
+// pollIn takes the next input - pushed on the WebSocket, else by a long
+// poll - and applies the frames.
 // Returns false when the session is gone and the loop should stop.
 func (a *Agent) pollIn(ctx context.Context, sid string, w io.Writer, onResize func(cols, rows uint16)) bool {
 	// On the WebSocket the input comes pushed; if it drops, by a long poll.

internal/proto/proto.go

@@ -1,8 +1,8 @@
 // Package proto describes the wire messages shared by the server and the agent.
 //
-// All agent<->server traffic is plain JSON over HTTP(S) long-polling so it
-// survives NAT and restrictive egress firewalls: the agent only ever makes
-// outbound requests.
+// All agent<->server traffic is plain JSON, on a WebSocket the agent opens or,
+// where that does not get through, over HTTP(S) long polls, so it survives
+// NAT and restrictive egress firewalls: the agent only ever connects out.
 package proto
 
 import "strings"
@@ -11,7 +11,7 @@ import "encoding/json"
 
 // Control poll message types (server -> agent, returned from /api/agent/poll).
 const (
-	// CtrlIdle is returned when the long-poll times out with nothing to do.
+	// CtrlIdle is returned when the control poll times out with nothing to do.
 	CtrlIdle = "idle"
 	// CtrlOpenTerminal tells the agent to spawn a PTY for the session id.
 	CtrlOpenTerminal = "open_terminal"
@@ -56,7 +56,8 @@ type EnrollResponse struct {
 	Token   string `json:"token"`
 }
 
-// ControlMessage is the body returned by the control long-poll.
+// ControlMessage is a command for the agent: on the WebSocket, or the body of
+// the control long poll.
 type ControlMessage struct {
 	Type      string     `json:"type"`
 	SessionID string     `json:"session_id,omitempty"`

internal/server/forward.go

@@ -12,8 +12,9 @@ import (
 
 // forwardManager owns the host-side listeners for port-forward rules. It
 // supports three transports:
-//   - "http": tunneled over the HTTP long-poll channel (works anywhere nginx
-//     reaches, highest latency);
+//   - "http": over the agent's own link to the panel - its WebSocket, or the
+//     HTTP long polls while there is none (works anywhere nginx reaches,
+//     highest latency);
 //   - "tcp":  direct TCP multiplexed over the tunnel port (low latency);
 //   - "udp":  direct UDP over the tunnel port.
 type forwardManager struct {
@@ -103,7 +104,8 @@ func (m *forwardManager) bridgeDirect(rule ForwardRule, conn net.Conn) {
 	at.openStream(rule.ClientPort, conn)
 }
 
-// bridgeHTTP wires a connection through the HTTP long-poll hub session.
+// bridgeHTTP wires a connection through a hub session: the agent carries it
+// over its WebSocket, or by long polls while it has none.
 func (m *forwardManager) bridgeHTTP(rule ForwardRule, conn net.Conn) {
 	sess := m.hub.CreateForward(rule.AgentID, rule.ClientPort)
 	defer m.hub.CloseSession(sess.ID)

internal/server/hub.go

@@ -7,8 +7,9 @@ import (
 	"github.com/x-grk/longpolling-remote-access/internal/proto"
 )
 
-// Hub is the in-memory broker between agents (HTTP long-polling) and the panel.
-// It carries three kinds of work to an agent through its single control poll:
+// Hub is the in-memory broker between agents (on a WebSocket, or by HTTP
+// long polls) and the panel. It carries three kinds of work to an agent
+// through its single control channel:
 // terminal sessions, port-forward streams, and one-shot tasks (file manager).
 // Nothing here is persisted.
 type Hub struct {

internal/server/web/static/pages.js

@@ -75,7 +75,7 @@
   App.register('forwards', {
     mount(root) {
       var notes = {
-        http: 'Трафик идёт через порт панели ' + root.dataset.panelPort + ' (long-poll). Порт ' + root.dataset.tunnelPort + ' не требуется.',
+        http: 'Трафик идёт через соединение агента с панелью (порт ' + root.dataset.panelPort + '): по WebSocket, без него - long-poll. Порт ' + root.dataset.tunnelPort + ' не требуется.',
         tcp:  'Требуется открытый порт ' + root.dataset.tunnelPort + '/tcp на хосте. Самая низкая задержка.',
         udp:  'Требуется открытый порт ' + root.dataset.tunnelPort + '/udp на хосте.'
       };

internal/server/web/templates/forwards.html

@@ -108,7 +108,7 @@
   <div class="card">
     <h2>Режимы</h2>
     <ul class="muted" style="font-size:14px; line-height:1.7">
-      <li><b>http-lp</b> - туннель поверх HTTP long-poll (через адрес панели, порт {{.PanelPort}}). Работает везде, где доступна панель, но задержка выше.</li>
+      <li><b>http-lp</b> - через соединение агента с панелью (порт {{.PanelPort}}): по WebSocket, а если он недоступен - по HTTP long-poll. Работает везде, где доступна панель, но задержка выше, чем у tcp.</li>
       <li><b>tcp</b> - прямой TCP-мультиплексор через порт <b>{{.TunnelPort}}</b> хоста. Минимальная задержка, keep-alive, TCP_NODELAY. Нужно открыть {{.TunnelPort}}/tcp на хосте.</li>
       <li><b>udp</b> - прямой UDP через порт <b>{{.TunnelPort}}</b> хоста. Нужно открыть {{.TunnelPort}}/udp.</li>
     </ul>