cancel approval flow on frontend when request is abandoned by client

doc/todo.md

@@ -1,7 +1,7 @@
 ## Definitely
 
 * ~~Switch to "process" provider for AWS credentials (much less hacky)~~
-* Frontend needs to react when request is cancelled from backend
+* ~~Frontend needs to react when request is cancelled from backend~~
 * Session timeout (plain duration, or activity-based?)
 * ~~Fix rehide behavior when new request comes in while old one is still being resolved~~
 * Additional hotkey configuration (approve/deny at the very least)

package.json

@@ -1,6 +1,6 @@
 {
   "name": "creddy",
-  "version": "0.4.3",
+  "version": "0.4.4",
   "scripts": {
     "dev": "vite",
     "build": "vite build",

src-tauri/Cargo.lock

@@ -1035,7 +1035,7 @@ dependencies = [
 
 [[package]]
 name = "creddy"
-version = "0.4.3"
+version = "0.4.4"
 dependencies = [
  "argon2",
  "auto-launch",

src-tauri/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "creddy"
-version = "0.4.3"
+version = "0.4.4"
 description = "A friendly AWS credentials manager"
 authors = ["Joseph Montanaro"]
 license = ""

src-tauri/src/clientinfo.rs

@@ -14,7 +14,6 @@ pub struct Client {
 
 
 pub fn get_process_parent_info(pid: u32) -> Result<Client, ClientInfoError> {
-    dbg!(pid);
     let sys_pid = Pid::from_u32(pid);
     let mut sys = System::new();   
     sys.refresh_process(sys_pid);

src-tauri/src/errors.rs

@@ -83,15 +83,33 @@ where
 }
 
 
+struct SerializeUpstream<E>(pub E);
+
+impl<E: Error> Serialize for SerializeUpstream<E> {
+    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+        let msg = format!("{}", self.0);
+        let mut map = serializer.serialize_map(None)?;
+        map.serialize_entry("msg", &msg)?;
+        map.serialize_entry("code", &None::<&str>)?;
+        map.serialize_entry("source", &None::<&str>)?;
+        map.end()
+    }
+}
+
 fn serialize_upstream_err<E, M>(err: &E, map: &mut M) -> Result<(), M::Error> 
 where
     E: Error,
     M: serde::ser::SerializeMap,
 {
-    let msg = err.source().map(|s| format!("{s}"));
-    map.serialize_entry("msg", &msg)?;
-    map.serialize_entry("code", &None::<&str>)?;
-    map.serialize_entry("source", &None::<&str>)?;
+    // let msg = err.source().map(|s| format!("{s}"));
+    // map.serialize_entry("msg", &msg)?;
+    // map.serialize_entry("code", &None::<&str>)?;
+    // map.serialize_entry("source", &None::<&str>)?;
+
+    match err.source() {
+        Some(src) => map.serialize_entry("source", &SerializeUpstream(src))?,
+        None => map.serialize_entry("source", &None::<&str>)?,
+    }
 
     Ok(())
 }
@@ -153,7 +171,7 @@ pub enum SendResponseError {
 }
 
 
-// errors encountered while handling an HTTP request
+// errors encountered while handling a client request
 #[derive(Debug, ThisError, AsRefStr)]
 pub enum HandlerError {
     #[error("Error writing to stream: {0}")]
@@ -164,6 +182,8 @@ pub enum HandlerError {
     BadRequest(#[from] serde_json::Error),
     #[error("HTTP request too large")]
     RequestTooLarge,
+    #[error("Connection closed early by client")]
+    Abandoned,
     #[error("Internal server error")]
     Internal(#[from] RecvError),
     #[error("Error accessing credentials: {0}")]
@@ -345,7 +365,6 @@ impl Serialize for SerializeWrapper<&GetSessionTokenError> {
 }
 
 
-
 impl_serialize_basic!(SetupError);
 impl_serialize_basic!(GetCredentialsError);
 impl_serialize_basic!(ClientInfoError);

src-tauri/src/server/mod.rs

@@ -43,6 +43,24 @@ pub enum Response {
 }
 
 
+struct CloseWaiter<'s> {
+    stream: &'s mut Stream,
+}
+
+impl<'s> CloseWaiter<'s> {
+    async fn wait_for_close(&mut self) -> std::io::Result<()> {
+        let mut buf = [0u8; 8];
+        loop {
+            match self.stream.read(&mut buf).await {
+                Ok(0) => break Ok(()),
+                Ok(_) => (),
+                Err(e) => break Err(e),
+            }
+        }
+    }
+}
+
+
 async fn handle(mut stream: Stream, app_handle: AppHandle, client_pid: u32) -> Result<(), HandlerError> 
 {
     // read from stream until delimiter is reached
@@ -59,13 +77,21 @@ async fn handle(mut stream: Stream, app_handle: AppHandle, client_pid: u32) -> R
     }
 
     let client = clientinfo::get_process_parent_info(client_pid)?;
+    let waiter = CloseWaiter { stream: &mut stream };
 
     let req: Request = serde_json::from_slice(&buf)?;
     let res = match req {
-        Request::GetAwsCredentials{ base } => get_aws_credentials(base, client, app_handle).await,
+        Request::GetAwsCredentials{ base } => get_aws_credentials(
+            base, client, app_handle, waiter
+        ).await,
         Request::InvokeShortcut(action) => invoke_shortcut(action).await,
     };
 
+    // doesn't make sense to send the error to the client if the client has already left
+    if let Err(HandlerError::Abandoned) = res {
+        return Err(HandlerError::Abandoned);
+    }
+
     let res = serde_json::to_vec(&res).unwrap();
     stream.write_all(&res).await?;
     Ok(())
@@ -78,7 +104,12 @@ async fn invoke_shortcut(action: ShortcutAction) -> Result<Response, HandlerErro
 }
 
 
-async fn get_aws_credentials(base: bool, client: Client, app_handle: AppHandle) -> Result<Response, HandlerError> {
+async fn get_aws_credentials(
+    base: bool,
+    client: Client,
+    app_handle: AppHandle,
+    mut waiter: CloseWaiter<'_>,
+) -> Result<Response, HandlerError> {
     let state = app_handle.state::<AppState>();
     let rehide_ms = {
         let config = state.config.read().await;
@@ -97,7 +128,14 @@ async fn get_aws_credentials(base: bool, client: Client, app_handle: AppHandle)
         let notification = AwsRequestNotification {id: request_id, client, base};
         app_handle.emit_all("credentials-request", &notification)?;
 
-        let response = chan_recv.await?;
+        let response = tokio::select! {
+            r = chan_recv => r?,
+            _ = waiter.wait_for_close() => {
+                app_handle.emit_all("request-cancelled", request_id)?;
+                return Err(HandlerError::Abandoned);
+            },
+        };
+
         match response.approval {
             Approval::Approved => {
                 if response.base {

src-tauri/tauri.conf.json

@@ -8,7 +8,7 @@
   },
   "package": {
     "productName": "creddy",
-    "version": "0.4.3"
+    "version": "0.4.4"
   },
   "tauri": {
     "allowlist": {

src/App.svelte

@@ -3,7 +3,7 @@ import { onMount } from 'svelte';
 import { listen } from '@tauri-apps/api/event';
 import { invoke } from '@tauri-apps/api/tauri';
 
-import { appState, acceptRequest } from './lib/state.js';
+import { appState, acceptRequest, cleanupRequest } from './lib/state.js';
 import { views, currentView, navigate } from './lib/routing.js';
 
 
@@ -16,6 +16,16 @@ listen('credentials-request', (tauriEvent) => {
     $appState.pendingRequests.put(tauriEvent.payload);
 });
 
+listen('request-cancelled', (tauriEvent) => {
+    const id = tauriEvent.payload;
+    if (id === $appState.currentRequest?.id) {
+        cleanupRequest()
+    }
+    else {
+        const found = $appState.pendingRequests.find_remove(r => r.id === id);
+    }
+});
+
 listen('launch-terminal-request', async (tauriEvent) => {
     if ($appState.currentRequest === null) {
         let status = await invoke('get_session_status');

src/lib/queue.js

@@ -30,5 +30,15 @@ export default function() {
             
             return this.items.shift();
         },
+
+        find_remove(pred) {
+            for (let i=0; i<this.items.length; i++) {
+                if (pred(this.items[i])) {
+                    this.items.splice(i, 1);
+                    return true;
+                }
+            }
+            return false;
+        },
     }
 }

src/lib/state.js

@@ -23,7 +23,7 @@ export async function acceptRequest() {
 }
 
 
-export function completeRequest() {
+export function cleanupRequest() {
     appState.update($appState => {
         $appState.currentRequest = null;
         return $appState;

src/ui/Link.svelte

@@ -30,7 +30,6 @@
             && alt === event.altKey
             && shift === event.shiftKey
         ) {
-            console.log({hotkey, ctrl, alt, shift});
             click();
         }
     }

src/views/Approve.svelte

@@ -3,7 +3,7 @@
     import { invoke } from '@tauri-apps/api/tauri';
 
     import { navigate } from '../lib/routing.js';
-    import { appState, completeRequest } from '../lib/state.js';
+    import { appState, cleanupRequest } from '../lib/state.js';
     import ErrorAlert from '../ui/ErrorAlert.svelte';
     import Link from '../ui/Link.svelte';
     import KeyCombo from '../ui/KeyCombo.svelte';
@@ -71,29 +71,29 @@
         if ($appState.currentRequest.response) {
             await respond();
         }
-    })
+    });
 </script>
 
 
 <!-- Don't render at all if we're just going to immediately proceed to the next screen -->
-{#if error || !$appState.currentRequest.response}
+{#if error || !$appState.currentRequest?.response}
     <div class="flex flex-col space-y-4 p-4 m-auto max-w-xl h-screen items-center justify-center">
         {#if error}
             <ErrorAlert bind:this={alert}>
-                {error}
+                {error.msg}
                 <svelte:fragment slot="buttons">
-                    <button class="btn btn-sm btn-alert-error" on:click={completeRequest}>Cancel</button>
+                    <button class="btn btn-sm btn-alert-error" on:click={cleanupRequest}>Cancel</button>
                     <button class="btn btn-sm btn-alert-error" on:click={respond}>Retry</button>
                 </svelte:fragment>
             </ErrorAlert>
         {/if}
 
-        {#if $appState.currentRequest.base}
+        {#if $appState.currentRequest?.base}
             <div class="alert alert-warning shadow-lg">
                 <div>
                     <svg xmlns="http://www.w3.org/2000/svg" class="stroke-current flex-shrink-0 h-6 w-6" fill="none" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M12 9v2m0 4h.01m-6.938 4h13.856c1.54 0 2.502-1.667 1.732-3L13.732 4c-.77-1.333-2.694-1.333-3.464 0L3.34 16c-.77 1.333.192 3 1.732 3z" /></svg>
                     <span>
-                        WARNING: This application is requesting your long-lived AWS credentials. 
+                        WARNING: This application is requesting your base AWS credentials. 
                         These credentials are less secure than session credentials, since they don't expire automatically.
                     </span>
                 </div>
@@ -113,7 +113,7 @@
 
         <div class="w-full grid grid-cols-[1fr_auto] items-center gap-y-6">
                 <!-- Don't display the option to approve with session credentials if base was specifically requested -->
-                {#if !$appState.currentRequest.base}
+                {#if !$appState.currentRequest?.base}
                     <h3 class="font-semibold">
                         Approve with session credentials
                     </h3>
@@ -126,7 +126,7 @@
 
                 <h3 class="font-semibold">
                     <span class="mr-2">
-                        {#if $appState.currentRequest.base}
+                        {#if $appState.currentRequest?.base}
                             Approve
                         {:else}
                             Approve with base credentials

src/views/ShowResponse.svelte

@@ -2,7 +2,7 @@
     import { onMount } from 'svelte';
     import { draw, fade } from 'svelte/transition';
 
-    import { appState, completeRequest } from '../lib/state.js';
+    import { appState, cleanupRequest } from '../lib/state.js';
     
     let success = false;
     let error = null;
@@ -13,7 +13,7 @@
 
     onMount(() => {
         window.setTimeout(
-            completeRequest,
+            cleanupRequest,
             // Extra 50ms so the window can finish disappearing before the redraw
             Math.min(5000, $appState.config.rehide_ms + 50),
         )