1// Package transport provides transport layer abstractions for VNC connections.
 2package transport
 3
 4import (
 5	"context"
 6	"crypto/tls"
 7	"net/http"
 8	"time"
 9)
10
11// Transport represents a connection transport for RFB protocol messages.
12// Unlike TCP streams, this interface is message-oriented to support WebSocket
13// framing where each RFB message is a discrete WebSocket message.
14type Transport interface {
15	// Read reads a single RFB message from the transport.
16	// Returns the message data or an error.
17	Read(ctx context.Context) ([]byte, error)
18
19	// Write writes a single RFB message to the transport.
20	Write(ctx context.Context, data []byte) error
21
22	// Close closes the transport connection.
23	Close() error
24
25	// SetReadLimit sets the maximum message size for reads.
26	SetReadLimit(limit int64)
27}
28
29// DialOptions configures transport connection establishment.
30type DialOptions struct {
31	// Headers to send with the connection request (for WebSocket).
32	Headers http.Header
33
34	// Cookies to send with the connection request.
35	Cookies []*http.Cookie
36
37	// Proxy URL for upstream proxy (http, https, socks5).
38	Proxy string
39
40	// Timeout for connection establishment.
41	Timeout time.Duration
42
43	// TLSConfig for TLS connections.
44	TLSConfig *tls.Config
45
46	// UserAgent to send with the connection request.
47	UserAgent string
48
49	// Subprotocols for WebSocket negotiation.
50	Subprotocols []string
51}
52
53// Dialer creates new transport connections.
54type Dialer interface {
55	// Dial establishes a new transport connection.
56	Dial(ctx context.Context, target string, opts *DialOptions) (Transport, error)
57}
58
59// NewDialOptions creates DialOptions with sensible defaults.
60func NewDialOptions() *DialOptions {
61	return &DialOptions{
62		Headers: make(http.Header),
63		Timeout: 30 * time.Second,
64	}
65}
66
67// AddHeader adds a header to the dial options.
68func (o *DialOptions) AddHeader(key, value string) {
69	if o.Headers == nil {
70		o.Headers = make(http.Header)
71	}
72	o.Headers.Add(key, value)
73}
74
75// SetCookie sets a cookie string (parsed as Cookie header).
76func (o *DialOptions) SetCookie(cookie string) {
77	o.AddHeader("Cookie", cookie)
78}