ssh_commander_core/
vnc_client.rs

1use crate::desktop_protocol::{DesktopProtocol, FrameUpdate, VncConfig};
2use anyhow::Result;
3use async_trait::async_trait;
4use tokio::sync::mpsc;
5use tokio_util::sync::CancellationToken;
6
7/// VNC (RFB protocol) remote desktop client.
8///
9/// Implements a lightweight VNC client using raw TCP with `tokio`.  The RFB
10/// protocol is simple enough (handshake → auth → framebuffer updates) that we
11/// avoid heavy C dependencies and implement it directly.
12///
13/// Supported encodings: Raw, CopyRect, Zlib (minimum set).
14/// Supported auth: VNC password challenge-response and no-auth.
15///
16/// The actual protocol implementation will be added in a follow-up.
17pub struct VncClient {
18    config: VncConfig,
19    desktop_width: u16,
20    desktop_height: u16,
21    connected: bool,
22}
23
24impl VncClient {
25    /// Attempt to establish a VNC connection.
26    ///
27    /// Currently returns an error because the RFB protocol implementation is
28    /// pending.  The function validates the config so callers get a meaningful
29    /// message.
30    pub async fn connect(config: &VncConfig) -> Result<Self> {
31        if config.host.is_empty() {
32            return Err(anyhow::anyhow!("VNC host cannot be empty"));
33        }
34
35        // TODO: implement actual VNC/RFB connection:
36        // 1. TCP connect to host:port
37        // 2. RFB version handshake (3.8)
38        // 3. Security type negotiation (VNC auth or no-auth)
39        // 4. VNC auth: DES challenge-response with password
40        // 5. ClientInit (shared flag)
41        // 6. ServerInit (desktop size, pixel format, name)
42        // 7. SetPixelFormat based on requested color depth
43        // 8. SetEncodings (Raw, CopyRect, Zlib)
44        Err(anyhow::anyhow!(
45            "VNC protocol support is not yet implemented. \
46             Connection to {}:{} cannot be established.",
47            config.host,
48            config.port
49        ))
50    }
51
52    /// Create a client instance in disconnected state (for testing).
53    #[allow(dead_code)]
54    fn new_disconnected(config: VncConfig) -> Self {
55        Self {
56            desktop_width: 1024,
57            desktop_height: 768,
58            config,
59            connected: false,
60        }
61    }
62}
63
64#[async_trait]
65impl DesktopProtocol for VncClient {
66    async fn start_frame_loop(
67        &self,
68        _frame_tx: mpsc::UnboundedSender<FrameUpdate>,
69        _cancel: CancellationToken,
70    ) -> Result<()> {
71        if !self.connected {
72            return Err(anyhow::anyhow!("VNC client is not connected"));
73        }
74        // TODO: request incremental framebuffer updates and decode them
75        Ok(())
76    }
77
78    async fn send_key(&self, _key_code: u32, _down: bool) -> Result<()> {
79        if !self.connected {
80            return Err(anyhow::anyhow!("VNC client is not connected"));
81        }
82        // TODO: send RFB KeyEvent message
83        Ok(())
84    }
85
86    async fn send_pointer(&self, _x: u16, _y: u16, _button_mask: u8) -> Result<()> {
87        if !self.connected {
88            return Err(anyhow::anyhow!("VNC client is not connected"));
89        }
90        // TODO: send RFB PointerEvent message
91        Ok(())
92    }
93
94    async fn request_full_frame(&self) -> Result<()> {
95        if !self.connected {
96            return Err(anyhow::anyhow!("VNC client is not connected"));
97        }
98        // TODO: send non-incremental FramebufferUpdateRequest
99        Ok(())
100    }
101
102    async fn set_clipboard(&self, _text: String) -> Result<()> {
103        if !self.connected {
104            return Err(anyhow::anyhow!("VNC client is not connected"));
105        }
106        // TODO: send ClientCutText message
107        Ok(())
108    }
109
110    fn desktop_size(&self) -> (u16, u16) {
111        (self.desktop_width, self.desktop_height)
112    }
113
114    async fn resize(&mut self, _width: u16, _height: u16) -> Result<()> {
115        // VNC does not support server-side resize.
116        // The frontend handles this by scaling the existing framebuffer client-side.
117        Ok(())
118    }
119
120    async fn disconnect(&mut self) -> Result<()> {
121        if self.connected {
122            // TODO: close TCP connection
123            self.connected = false;
124            tracing::info!(
125                "VNC disconnected from {}:{}",
126                self.config.host,
127                self.config.port
128            );
129        }
130        Ok(())
131    }
132}
ssh_commander_core/vnc_client.rs

ssh_commander_core/
vnc_client.rs
