Fix VNC connection issue

README.md

@@ -16,6 +16,7 @@ sudo apt install qemu-kvm libvirt-daemon-system
 3. Allow the current user to manage VMs:
 ```
 sudo adduser $USER libvirt
+sudo adduser $USER kvm 
 ```
 
 > Note: You will need to login again for this change to take effect.

virtweb_backend/src/actors/vnc_tokens_actor.rs

@@ -6,14 +6,14 @@ use std::time::Duration;
 
 const TOKENS_CLEAN_INTERVAL: Duration = Duration::from_secs(60);
 const VNC_TOKEN_LEN: usize = 15;
-const VNC_TOKEN_LIFETIME: u64 = 120;
+pub const VNC_TOKEN_LIFETIME: u64 = 30;
 
 #[derive(thiserror::Error, Debug)]
 enum VNCTokenError {
-    #[error("Could not consume token, because it does not exist!")]
-    ConsumeErrorTokenNotFound,
-    #[error("Could not consume token, because it has expired!")]
-    ConsumeErrorTokenExpired,
+    #[error("Could not use token, because it does not exist!")]
+    UseErrorTokenNotFound,
+    #[error("Could not use token, because it has expired!")]
+    UseErrorTokenExpired,
 }
 
 #[derive(Debug, Clone)]
@@ -64,24 +64,22 @@ impl Handler<IssueTokenReq> for VNCTokensActor {
 
 #[derive(Message)]
 #[rtype(result = "anyhow::Result<XMLUuid>")]
-pub struct ConsumeTokenReq(String);
+pub struct UseTokenReq(String);
 
-impl Handler<ConsumeTokenReq> for VNCTokensActor {
+impl Handler<UseTokenReq> for VNCTokensActor {
     type Result = anyhow::Result<XMLUuid>;
 
-    fn handle(&mut self, msg: ConsumeTokenReq, _ctx: &mut Self::Context) -> Self::Result {
-        log::debug!("Attempt to consume a token {:?}", msg.0);
+    fn handle(&mut self, msg: UseTokenReq, _ctx: &mut Self::Context) -> Self::Result {
+        log::debug!("Attempt to use a token {:?}", msg.0);
 
-        let token_index = self
+        let token = self
             .0
             .iter()
-            .position(|i| i.token == msg.0)
-            .ok_or(VNCTokenError::ConsumeErrorTokenNotFound)?;
-
-        let token = self.0.remove(token_index);
+            .find(|i| i.token == msg.0)
+            .ok_or(VNCTokenError::UseErrorTokenNotFound)?;
 
         if token.is_expired() {
-            return Err(VNCTokenError::ConsumeErrorTokenExpired.into());
+            return Err(VNCTokenError::UseErrorTokenExpired.into());
         }
 
         Ok(token.vm)
@@ -101,8 +99,8 @@ impl VNCTokensManager {
         self.0.send(IssueTokenReq(id)).await?
     }
 
-    /// Consume a VNC access token
-    pub async fn consume_token(&self, token: String) -> anyhow::Result<XMLUuid> {
-        self.0.send(ConsumeTokenReq(token)).await?
+    /// Use a VNC access token
+    pub async fn use_token(&self, token: String) -> anyhow::Result<XMLUuid> {
+        self.0.send(UseTokenReq(token)).await?
     }
 }

virtweb_backend/src/controllers/server_controller.rs

@@ -1,3 +1,4 @@
+use crate::actors::vnc_tokens_actor::VNC_TOKEN_LIFETIME;
 use crate::app_config::AppConfig;
 use crate::constants;
 use crate::constants::{DISK_NAME_MAX_LEN, DISK_NAME_MIN_LEN, DISK_SIZE_MAX, DISK_SIZE_MIN};
@@ -29,6 +30,7 @@ struct LenConstraints {
 #[derive(serde::Serialize)]
 struct ServerConstraints {
     iso_max_size: usize,
+    vnc_token_duration: u64,
     vm_name_size: LenConstraints,
     vm_title_size: LenConstraints,
     memory_size: LenConstraints,
@@ -47,6 +49,8 @@ pub async fn static_config(local_auth: LocalAuthEnabled) -> impl Responder {
         constraints: ServerConstraints {
             iso_max_size: constants::ISO_MAX_SIZE,
 
+            vnc_token_duration: VNC_TOKEN_LIFETIME,
+
             vm_name_size: LenConstraints { min: 2, max: 50 },
             vm_title_size: LenConstraints { min: 0, max: 50 },
             memory_size: LenConstraints {

virtweb_backend/src/controllers/vm_controller.rs

@@ -269,7 +269,7 @@ pub async fn vnc(
     req: HttpRequest,
     stream: web::Payload,
 ) -> HttpResult {
-    let domain_id = manager.consume_token(token.0.token).await?;
+    let domain_id = manager.use_token(token.0.token).await?;
     let domain = client.get_single_domain(domain_id).await?;
 
     let socket_path = match domain.devices.graphics {

virtweb_frontend/src/api/ServerApi.ts

@@ -10,6 +10,7 @@ export interface ServerConfig {
 
 export interface ServerConstraints {
   iso_max_size: number;
+  vnc_token_duration: number;
   vm_name_size: LenConstraint;
   vm_title_size: LenConstraint;
   memory_size: LenConstraint;

virtweb_frontend/src/routes/VNCRoute.tsx

@@ -1,10 +1,17 @@
-import React from "react";
+import React, { useEffect } from "react";
 import { useParams } from "react-router-dom";
 import { VncScreen } from "react-vnc";
+import { ServerApi } from "../api/ServerApi";
 import { VMApi, VMInfo } from "../api/VMApi";
 import { useSnackbar } from "../hooks/providers/SnackbarProvider";
+import { time } from "../utils/DateUtils";
 import { AsyncWidget } from "../widgets/AsyncWidget";
 
+interface VNCTokenInfo {
+  url: string;
+  expire: number;
+}
+
 export function VNCRoute(): React.ReactElement {
   const { uuid } = useParams();
 
@@ -27,52 +34,58 @@ export function VNCRoute(): React.ReactElement {
 function VNCInner(p: { vm: VMInfo }): React.ReactElement {
   const snackbar = useSnackbar();
 
-  const counter = React.useRef(false);
-  const [url, setURL] = React.useState<string | undefined>();
+  const [token, setToken] = React.useState<VNCTokenInfo | undefined>();
+  const [counter, setCounter] = React.useState(1);
 
-  const load = async () => {
+  const connect = async (force: boolean) => {
     try {
+      if (force) setCounter(counter + 1);
+
+      // Check if getting new time is useless
+      if ((token?.expire ?? 0) > time()) return;
+
+      setToken(undefined);
+
       const u = await VMApi.OneShotVNCURL(p.vm);
-      console.info(u);
-      if (counter.current === false) {
-        counter.current = true;
-        setURL(u);
-      }
+
+      if (!token)
+        setToken({
+          expire: time() + ServerApi.Config.constraints.vnc_token_duration,
+          url: u,
+        });
     } catch (e) {
       console.error(e);
       snackbar("Failed to initialize VNC connection!");
     }
   };
 
-  const reconnect = () => {
-    counter.current = false;
-    setURL(undefined);
+  const disconnected = () => {
+    connect(true);
   };
 
+  useEffect(() => {
+    connect(false);
+  });
+
+  if (token === undefined)
+    return <p>Please wait, connecting to the machine...</p>;
+
   return (
-    <AsyncWidget
-      loadKey={counter.current}
-      load={load}
-      ready={url !== undefined && counter.current}
-      errMsg="Failed to get a token to initialize VNC connection!"
-      build={() => (
-        <div
-          style={{
-            display: "flex",
-            alignItems: "center",
-            justifyContent: "center",
-            height: "100%",
-          }}
-        >
-          <VncScreen
-            url={url!}
-            onDisconnect={() => {
-              console.info("VNC disconnected " + url);
-              reconnect();
-            }}
-          />
-        </div>
-      )}
-    />
+    <div
+      style={{
+        display: "flex",
+        alignItems: "center",
+        justifyContent: "center",
+        height: "100%",
+      }}
+    >
+      <VncScreen
+        url={token!.url}
+        onDisconnect={() => {
+          console.info("VNC disconnected " + token?.url);
+          disconnected();
+        }}
+      />
+    </div>
   );
 }

virtweb_frontend/src/utils/DateUtils.ts

@@ -0,0 +1,6 @@
+/**
+ * Get current UNIX time, in seconds
+ */
+export function time(): number {
+  return Math.floor(new Date().getTime() / 1000);
+}