feat: 新增 MJPEG/H.264 VNC 初步支持

src/vnc/rfb.rs

@@ -0,0 +1,529 @@
+use std::net::SocketAddr;
+
+use bytes::Bytes;
+use des::cipher::{BlockEncrypt, KeyInit};
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::net::TcpStream;
+use tokio::sync::broadcast;
+
+use crate::config::{VncConfig, VncEncoding};
+use crate::error::{AppError, Result};
+use crate::hid::{
+    CanonicalKey, KeyEventType, KeyboardEvent, KeyboardModifiers, MouseButton, MouseEvent,
+    MouseEventType,
+};
+
+const ENCODING_TIGHT: i32 = 7;
+const ENCODING_H264: i32 = 50;
+const ENCODING_DESKTOP_SIZE: i32 = -223;
+
+pub enum RfbFrame {
+    Jpeg {
+        data: Bytes,
+        width: u16,
+        height: u16,
+    },
+    H264 {
+        data: Bytes,
+        width: u16,
+        height: u16,
+        key: bool,
+    },
+}
+
+pub enum RfbInputEvent {
+    Key(RfbKeyEvent),
+    Pointer(RfbPointerEvent),
+    Clipboard(String),
+    Ignored,
+    Disconnected,
+}
+
+pub struct RfbKeyEvent {
+    pub down: bool,
+    pub keysym: u32,
+}
+
+pub struct RfbPointerEvent {
+    pub x: u16,
+    pub y: u16,
+    pub button_mask: u8,
+    pub previous_button_mask: u8,
+}
+
+#[derive(Default)]
+struct ClientEncodings {
+    has_tight: bool,
+    tight_jpeg_quality: u8,
+    has_h264: bool,
+    has_resize: bool,
+}
+
+pub struct RfbClient {
+    stream: TcpStream,
+    peer: SocketAddr,
+    config: VncConfig,
+    encodings: ClientEncodings,
+    width: u16,
+    height: u16,
+    last_buttons: u8,
+    h264_waiting_keyframe: bool,
+    shutdown_tx: broadcast::Sender<()>,
+}
+
+impl RfbClient {
+    pub fn new(stream: TcpStream, peer: SocketAddr, config: VncConfig) -> Self {
+        let (shutdown_tx, _) = broadcast::channel(1);
+        Self {
+            stream,
+            peer,
+            config,
+            encodings: ClientEncodings::default(),
+            width: 800,
+            height: 600,
+            last_buttons: 0,
+            h264_waiting_keyframe: true,
+            shutdown_tx,
+        }
+    }
+
+    pub fn set_size(&mut self, width: u16, height: u16) {
+        self.width = width.max(1);
+        self.height = height.max(1);
+    }
+
+    pub fn shutdown_receiver(&self) -> broadcast::Receiver<()> {
+        self.shutdown_tx.subscribe()
+    }
+
+    pub async fn handshake(&mut self) -> Result<()> {
+        self.stream.write_all(b"RFB 003.008\n").await?;
+        let mut version = [0u8; 12];
+        self.stream.read_exact(&mut version).await?;
+        if !version.starts_with(b"RFB 003.00") {
+            return Err(AppError::BadRequest("Invalid RFB version".to_string()));
+        }
+
+        self.stream.write_all(&[1, 2]).await?;
+        let sec_type = read_u8(&mut self.stream).await?;
+        if sec_type != 2 {
+            return Err(AppError::BadRequest("VNCAuth is required".to_string()));
+        }
+        self.handle_vnc_auth().await?;
+
+        let _shared = read_u8(&mut self.stream).await?;
+        self.write_server_init().await?;
+        self.read_until_set_encodings().await?;
+        self.validate_encoding_policy()?;
+        tracing::info!(
+            "VNC client {} negotiated encoding {:?}",
+            self.peer,
+            self.config.encoding
+        );
+        Ok(())
+    }
+
+    async fn handle_vnc_auth(&mut self) -> Result<()> {
+        let challenge: [u8; 16] = rand::random();
+        self.stream.write_all(&challenge).await?;
+        let mut response = [0u8; 16];
+        self.stream.read_exact(&mut response).await?;
+        let password = self.config.password.as_deref().unwrap_or("");
+        let expected = encrypt_vnc_challenge(&challenge, password)?;
+        let ok = response == expected;
+        self.stream
+            .write_all(&(if ok { 0u32 } else { 1u32 }).to_be_bytes())
+            .await?;
+        if !ok {
+            return Err(AppError::BadRequest("Invalid VNC password".to_string()));
+        }
+        Ok(())
+    }
+
+    async fn write_server_init(&mut self) -> Result<()> {
+        self.stream.write_all(&self.width.to_be_bytes()).await?;
+        self.stream.write_all(&self.height.to_be_bytes()).await?;
+        self.stream
+            .write_all(&[32, 24, 0, 1, 0, 255, 0, 255, 0, 255, 16, 8, 0, 0, 0, 0])
+            .await?;
+        let name = b"One-KVM VNC";
+        self.stream
+            .write_all(&(name.len() as u32).to_be_bytes())
+            .await?;
+        self.stream.write_all(name).await?;
+        self.stream.flush().await?;
+        Ok(())
+    }
+
+    async fn read_until_set_encodings(&mut self) -> Result<()> {
+        loop {
+            let msg_type = read_u8(&mut self.stream).await?;
+            match msg_type {
+                0 => {
+                    let mut buf = [0u8; 19];
+                    self.stream.read_exact(&mut buf).await?;
+                }
+                2 => {
+                    let _pad = read_u8(&mut self.stream).await?;
+                    let count = read_u16(&mut self.stream).await?;
+                    if count == 0 || count > 1024 {
+                        return Err(AppError::BadRequest(
+                            "Invalid VNC encoding list".to_string(),
+                        ));
+                    }
+                    let mut encodings = ClientEncodings::default();
+                    for _ in 0..count {
+                        let enc = read_i32(&mut self.stream).await?;
+                        match enc {
+                            ENCODING_TIGHT => encodings.has_tight = true,
+                            ENCODING_H264 => encodings.has_h264 = true,
+                            ENCODING_DESKTOP_SIZE => encodings.has_resize = true,
+                            -32..=-23 => {
+                                let q = ((enc + 33) * 10).clamp(10, 100) as u8;
+                                encodings.tight_jpeg_quality = encodings.tight_jpeg_quality.max(q);
+                            }
+                            _ => {}
+                        }
+                    }
+                    self.encodings = encodings;
+                    return Ok(());
+                }
+                3 => {
+                    let mut buf = [0u8; 9];
+                    self.stream.read_exact(&mut buf).await?;
+                }
+                4 => {
+                    let mut buf = [0u8; 7];
+                    self.stream.read_exact(&mut buf).await?;
+                }
+                5 => {
+                    let mut buf = [0u8; 5];
+                    self.stream.read_exact(&mut buf).await?;
+                }
+                6 => {
+                    let mut hdr = [0u8; 7];
+                    self.stream.read_exact(&mut hdr).await?;
+                    let len = u32::from_be_bytes([hdr[3], hdr[4], hdr[5], hdr[6]]) as usize;
+                    let mut data = vec![0u8; len.min(1024 * 1024)];
+                    self.stream.read_exact(&mut data).await?;
+                }
+                _ => {
+                    return Err(AppError::BadRequest(format!(
+                        "Unsupported RFB message {}",
+                        msg_type
+                    )))
+                }
+            }
+        }
+    }
+
+    fn validate_encoding_policy(&self) -> Result<()> {
+        match self.config.encoding {
+            VncEncoding::TightJpeg => {
+                if !self.encodings.has_tight || self.encodings.tight_jpeg_quality == 0 {
+                    return Err(AppError::BadRequest(
+                        "VNC client must support Tight JPEG encoding".to_string(),
+                    ));
+                }
+            }
+            VncEncoding::H264 => {
+                if !self.encodings.has_h264 {
+                    return Err(AppError::BadRequest(
+                        "VNC client must support Open H.264 encoding".to_string(),
+                    ));
+                }
+            }
+        }
+        Ok(())
+    }
+
+    pub async fn read_input_event(&mut self) -> Result<RfbInputEvent> {
+        let msg_type = match read_u8(&mut self.stream).await {
+            Ok(v) => v,
+            Err(AppError::Io(err)) if err.kind() == std::io::ErrorKind::UnexpectedEof => {
+                return Ok(RfbInputEvent::Disconnected);
+            }
+            Err(err) => return Err(err),
+        };
+        match msg_type {
+            0 => {
+                let mut buf = [0u8; 19];
+                self.stream.read_exact(&mut buf).await?;
+                Ok(RfbInputEvent::Ignored)
+            }
+            2 => {
+                let _pad = read_u8(&mut self.stream).await?;
+                let count = read_u16(&mut self.stream).await?;
+                for _ in 0..count {
+                    let _ = read_i32(&mut self.stream).await?;
+                }
+                Ok(RfbInputEvent::Ignored)
+            }
+            3 => {
+                let mut buf = [0u8; 9];
+                self.stream.read_exact(&mut buf).await?;
+                Ok(RfbInputEvent::Ignored)
+            }
+            4 => {
+                let down = read_u8(&mut self.stream).await? != 0;
+                let mut pad = [0u8; 2];
+                self.stream.read_exact(&mut pad).await?;
+                let keysym = read_u32(&mut self.stream).await?;
+                Ok(RfbInputEvent::Key(RfbKeyEvent { down, keysym }))
+            }
+            5 => {
+                let button_mask = read_u8(&mut self.stream).await?;
+                let x = read_u16(&mut self.stream).await?;
+                let y = read_u16(&mut self.stream).await?;
+                let previous_button_mask = self.last_buttons;
+                self.last_buttons = button_mask;
+                Ok(RfbInputEvent::Pointer(RfbPointerEvent {
+                    x,
+                    y,
+                    button_mask,
+                    previous_button_mask,
+                }))
+            }
+            6 => {
+                let mut hdr = [0u8; 7];
+                self.stream.read_exact(&mut hdr).await?;
+                let len = u32::from_be_bytes([hdr[3], hdr[4], hdr[5], hdr[6]]) as usize;
+                let mut data = vec![0u8; len.min(1024 * 1024)];
+                self.stream.read_exact(&mut data).await?;
+                Ok(RfbInputEvent::Clipboard(
+                    String::from_utf8_lossy(&data).to_string(),
+                ))
+            }
+            _ => Err(AppError::BadRequest(format!(
+                "Unsupported RFB message {}",
+                msg_type
+            ))),
+        }
+    }
+
+    pub async fn send_frame(&mut self, frame: RfbFrame) -> Result<()> {
+        match frame {
+            RfbFrame::Jpeg {
+                data,
+                width,
+                height,
+            } => {
+                self.maybe_resize(width, height).await?;
+                self.write_frame_header(width, height, ENCODING_TIGHT)
+                    .await?;
+                write_tight_jpeg_payload(&mut self.stream, &data).await?;
+            }
+            RfbFrame::H264 {
+                data,
+                width,
+                height,
+                key,
+            } => {
+                self.maybe_resize(width, height).await?;
+                if self.h264_waiting_keyframe && !key {
+                    return Ok(());
+                }
+                self.write_frame_header(width, height, ENCODING_H264)
+                    .await?;
+                self.stream
+                    .write_all(&(data.len() as u32).to_be_bytes())
+                    .await?;
+                self.stream
+                    .write_all(&(self.h264_waiting_keyframe as u32).to_be_bytes())
+                    .await?;
+                self.stream.write_all(&data).await?;
+                self.h264_waiting_keyframe = false;
+            }
+        }
+        self.stream.flush().await?;
+        Ok(())
+    }
+
+    async fn maybe_resize(&mut self, width: u16, height: u16) -> Result<()> {
+        if width == self.width && height == self.height {
+            return Ok(());
+        }
+        if !self.encodings.has_resize {
+            return Err(AppError::BadRequest(
+                "VNC client does not support DesktopSize resize; reconnect required".to_string(),
+            ));
+        }
+        self.write_frame_header(width, height, ENCODING_DESKTOP_SIZE)
+            .await?;
+        self.width = width;
+        self.height = height;
+        self.h264_waiting_keyframe = true;
+        Ok(())
+    }
+
+    async fn write_frame_header(&mut self, width: u16, height: u16, encoding: i32) -> Result<()> {
+        self.stream.write_all(&[0, 0]).await?;
+        self.stream.write_all(&1u16.to_be_bytes()).await?;
+        self.stream.write_all(&0u16.to_be_bytes()).await?;
+        self.stream.write_all(&0u16.to_be_bytes()).await?;
+        self.stream.write_all(&width.to_be_bytes()).await?;
+        self.stream.write_all(&height.to_be_bytes()).await?;
+        self.stream.write_all(&encoding.to_be_bytes()).await?;
+        Ok(())
+    }
+}
+
+async fn write_tight_jpeg_payload(stream: &mut TcpStream, data: &[u8]) -> Result<()> {
+    if data.len() > 0x3f_ffff {
+        return Err(AppError::BadRequest(
+            "JPEG frame too large for Tight encoding".to_string(),
+        ));
+    }
+    stream.write_all(&[0b1001_1111]).await?;
+    write_compact_len(stream, data.len()).await?;
+    stream.write_all(data).await?;
+    Ok(())
+}
+
+async fn write_compact_len(stream: &mut TcpStream, len: usize) -> Result<()> {
+    if len <= 127 {
+        stream.write_all(&[(len & 0x7f) as u8]).await?;
+    } else if len <= 16_383 {
+        stream
+            .write_all(&[((len & 0x7f) as u8) | 0x80, ((len >> 7) & 0x7f) as u8])
+            .await?;
+    } else {
+        stream
+            .write_all(&[
+                ((len & 0x7f) as u8) | 0x80,
+                (((len >> 7) & 0x7f) as u8) | 0x80,
+                ((len >> 14) & 0xff) as u8,
+            ])
+            .await?;
+    }
+    Ok(())
+}
+
+fn encrypt_vnc_challenge(challenge: &[u8; 16], password: &str) -> Result<[u8; 16]> {
+    let mut key = [0u8; 8];
+    for (dst, src) in key.iter_mut().zip(password.as_bytes().iter().take(8)) {
+        *dst = reverse_bits(*src);
+    }
+    let cipher = des::Des::new_from_slice(&key)
+        .map_err(|_| AppError::BadRequest("Invalid VNC DES key".to_string()))?;
+    let mut out = *challenge;
+    for chunk in out.chunks_exact_mut(8) {
+        cipher.encrypt_block(chunk.into());
+    }
+    Ok(out)
+}
+
+fn reverse_bits(byte: u8) -> u8 {
+    byte.reverse_bits()
+}
+
+async fn read_u8(stream: &mut TcpStream) -> Result<u8> {
+    let mut buf = [0u8; 1];
+    stream.read_exact(&mut buf).await?;
+    Ok(buf[0])
+}
+
+async fn read_u16(stream: &mut TcpStream) -> Result<u16> {
+    let mut buf = [0u8; 2];
+    stream.read_exact(&mut buf).await?;
+    Ok(u16::from_be_bytes(buf))
+}
+
+async fn read_u32(stream: &mut TcpStream) -> Result<u32> {
+    let mut buf = [0u8; 4];
+    stream.read_exact(&mut buf).await?;
+    Ok(u32::from_be_bytes(buf))
+}
+
+async fn read_i32(stream: &mut TcpStream) -> Result<i32> {
+    let mut buf = [0u8; 4];
+    stream.read_exact(&mut buf).await?;
+    Ok(i32::from_be_bytes(buf))
+}
+
+pub fn key_event_to_hid(event: RfbKeyEvent) -> Option<KeyboardEvent> {
+    let key = keysym_to_key(event.keysym)?;
+    Some(KeyboardEvent {
+        event_type: if event.down {
+            KeyEventType::Down
+        } else {
+            KeyEventType::Up
+        },
+        key,
+        modifiers: KeyboardModifiers::default(),
+    })
+}
+
+fn keysym_to_key(keysym: u32) -> Option<CanonicalKey> {
+    match keysym {
+        0xff08 => Some(CanonicalKey::Backspace),
+        0xff09 => Some(CanonicalKey::Tab),
+        0xff0d => Some(CanonicalKey::Enter),
+        0xff1b => Some(CanonicalKey::Escape),
+        0xffff => Some(CanonicalKey::Delete),
+        0xff50 => Some(CanonicalKey::Home),
+        0xff51 => Some(CanonicalKey::ArrowLeft),
+        0xff52 => Some(CanonicalKey::ArrowUp),
+        0xff53 => Some(CanonicalKey::ArrowRight),
+        0xff54 => Some(CanonicalKey::ArrowDown),
+        0xff55 => Some(CanonicalKey::PageUp),
+        0xff56 => Some(CanonicalKey::PageDown),
+        0xff57 => Some(CanonicalKey::End),
+        0xff63 => Some(CanonicalKey::Insert),
+        0xffbe..=0xffc9 => CanonicalKey::from_hid_usage((keysym - 0xffbe + 0x3a) as u8),
+        0x20 => Some(CanonicalKey::Space),
+        0x61..=0x7a => CanonicalKey::from_hid_usage((keysym - 0x61 + 0x04) as u8),
+        0x41..=0x5a => CanonicalKey::from_hid_usage((keysym - 0x41 + 0x04) as u8),
+        0x31..=0x39 => CanonicalKey::from_hid_usage((keysym - 0x31 + 0x1e) as u8),
+        0x30 => Some(CanonicalKey::Digit0),
+        0x2d => Some(CanonicalKey::Minus),
+        0x3d => Some(CanonicalKey::Equal),
+        0x5b => Some(CanonicalKey::BracketLeft),
+        0x5d => Some(CanonicalKey::BracketRight),
+        0x5c => Some(CanonicalKey::Backslash),
+        0x3b => Some(CanonicalKey::Semicolon),
+        0x27 => Some(CanonicalKey::Quote),
+        0x60 => Some(CanonicalKey::Backquote),
+        0x2c => Some(CanonicalKey::Comma),
+        0x2e => Some(CanonicalKey::Period),
+        0x2f => Some(CanonicalKey::Slash),
+        _ => None,
+    }
+}
+
+pub fn pointer_event_to_hid(event: RfbPointerEvent, width: u16, height: u16) -> Vec<MouseEvent> {
+    let mut out = Vec::new();
+    let abs_x = ((event.x as u64 * 32767) / width.max(1) as u64) as i32;
+    let abs_y = ((event.y as u64 * 32767) / height.max(1) as u64) as i32;
+    out.push(MouseEvent {
+        event_type: MouseEventType::MoveAbs,
+        x: abs_x,
+        y: abs_y,
+        button: None,
+        scroll: 0,
+    });
+
+    if event.button_mask & 0x08 != 0 {
+        out.push(MouseEvent::scroll(1));
+    }
+    if event.button_mask & 0x10 != 0 {
+        out.push(MouseEvent::scroll(-1));
+    }
+
+    for (bit, button) in [
+        (0x01, MouseButton::Left),
+        (0x02, MouseButton::Middle),
+        (0x04, MouseButton::Right),
+    ] {
+        if (event.button_mask ^ event.previous_button_mask) & bit == 0 {
+            continue;
+        }
+        if event.button_mask & bit != 0 {
+            out.push(MouseEvent::button_down(button));
+        } else {
+            out.push(MouseEvent::button_up(button));
+        }
+    }
+
+    out
+}