qmp: cleanup pass + executing commands works

Some more helpers (like, `execute_hmp("info block".into())` might be nice to add, for now this works.
This commit is contained in:
Lily Tsuru 2024-05-09 00:48:42 -04:00
parent 4cda248591
commit a37d2468c2
6 changed files with 155 additions and 57 deletions

View file

@ -11,8 +11,8 @@ async fn main() {
tracing::subscriber::set_global_default(subscriber).expect("You Banned");
// This is test code..
// Create a stream to connect
let stream = UnixStream::connect("/home/lily/vms/xpiss/qmp.sock")
.await
.expect("Could not connect");
@ -20,15 +20,24 @@ async fn main() {
let client = qmp::QmpClient::new(stream);
// Handshake QMP
client.handshake().await.expect("Could not handshake QMP");
println!("handshook QMP");
// let's try to get all RESET events
let mut rx = client.subscribe_to_event("RESET".into()).await.unwrap();
// let's try to get all STOP events from QMP now.
let mut rx = client.subscribe_to_event("STOP".into()).await.unwrap();
// If this worked, then now we can recieve all the events.
// This code here allows running a VM with the -no-shutdown option,
// automatially resetting it on shutdown.
while let Some(message) = rx.recv().await {
println!("Got event! {:?}", message);
println!("Got stop event! {:?}", message);
let res1 = client.execute("system_reset".into(), None).await.expect("FUCK");
let res2 = client.execute("cont".into(), None).await.expect("FUCK");
println!("Result of running: {:?}, {:?}", res1, res2);
}

View file

@ -3,29 +3,24 @@
use std::collections::HashMap;
use std::time::Duration;
use serde_json::json;
// TODO
use tokio::{
io::{AsyncBufReadExt, AsyncReadExt, AsyncWriteExt, BufStream},
sync::{mpsc, mpsc::error::TryRecvError, oneshot},
io::{AsyncReadExt, AsyncWriteExt, BufStream},
sync::{mpsc, oneshot},
};
use super::{
result,
io,
types::{self, QmpHandshake},
io, result,
types::{self, QmpExecute, QmpHandshake},
};
enum QmpClientState {
enum QmpActorState {
/// Disconnected.
Disconnected,
ConnectedToServer,
/// The server
HandshakingServer,
/// Handshake passed successfully and we're ready.
Ready,
}
@ -42,6 +37,10 @@ pub enum QmpActorMessage {
/// Used to send a QMP message.
QmpDoSend {
/// The message to send
command: String,
arguments: Option<serde_json::Value>,
/// The oneshot response.
tx: oneshot::Sender<serde_json::Value>,
},
@ -53,14 +52,12 @@ pub enum QmpActorMessage {
},
}
struct QmpClientActor<S>
where
S: AsyncReadExt + AsyncWriteExt + Unpin + Send,
{
stream: BufStream<S>,
state: QmpClientState,
state: QmpActorState,
rx: mpsc::Receiver<QmpActorMessage>,
@ -72,7 +69,7 @@ where
last_response_id: u32,
/// All in flight responses.
response_tx: HashMap<u32, oneshot::Sender<serde_json::Value>>,
response_tx: HashMap<u32, Option<oneshot::Sender<serde_json::Value>>>,
}
impl<S> QmpClientActor<S>
@ -82,7 +79,7 @@ where
fn new(stream: S, rx: mpsc::Receiver<QmpActorMessage>) -> Self {
Self {
stream: BufStream::new(stream),
state: QmpClientState::ConnectedToServer,
state: QmpActorState::ConnectedToServer,
rx: rx,
event_tx: HashMap::new(),
last_response_id: 0,
@ -91,7 +88,6 @@ where
}
async fn handshake(&mut self) -> result::Result<types::QmpHandshake> {
self.state = QmpClientState::HandshakingServer;
let handshake_as_string = io::read_qmp_line(&mut self.stream).await?;
let handshake_json =
serde_json::from_str::<types::QmpHandshake>(handshake_as_string.as_str())?;
@ -101,24 +97,24 @@ where
"execute": "qmp_capabilities"
});
let serialized = serde_json::ser::to_string(&handshake_response)?;
io::write_qmp_line(&mut self.stream, &serialized).await?;
// Read what the server responded back
// FIXME: Make sure it's not an error.
let _handshake_server_response_as_string = io::read_qmp_line(&mut self.stream).await?;
// let handshake_server_response_json =
// serde_json::from_str::<serde_json::Value>(handshake_server_response_as_string.as_str())?;
// let handshake_server_response_json =
// serde_json::from_str::<serde_json::Value>(handshake_server_response_as_string.as_str())?;
self.state = QmpClientState::Ready;
self.state = QmpActorState::Ready;
Ok(handshake_json)
}
async fn handle_message(&mut self, msg: QmpActorMessage) {
async fn handle_message(&mut self, msg: QmpActorMessage) -> result::Result<()> {
match msg {
QmpActorMessage::DoClose => {
println!("Byes byes!!!")
// FIXME: Actually close things.
}
QmpActorMessage::QmpDoHandshake { tx } => {
@ -129,37 +125,81 @@ where
// this can only really fail in a way where it panics i'm pretty sure
QmpActorMessage::QmpSubscribeToEvent { event_name, tx } => {
self.event_tx.insert(event_name.to_uppercase(), tx);
},
QmpActorMessage::QmpDoSend { command, arguments, tx } => {
self.response_tx.insert(self.last_response_id, Some(tx));
self.send_execute(command, &arguments).await?;
self.last_response_id += 1;
}
_ => tracing::error!("Unknown message"),
}
Ok(())
}
async fn run(mut self) {
async fn handle_qmp_read(&mut self, line: &String) -> result::Result<()> {
let res = serde_json::from_str::<serde_json::Value>(line.as_str())?;
// Check if this is an event
if let Some(event) = res.get("event") {
let str = String::from(event.as_str().unwrap());
// Send the event to the subscriber
if let Some(tx) = self.event_tx.get(&str) {
let _ = tx.send(res.clone()).await;
}
}
// Check for a execute resposne
if let Some(id) = res.get("id") {
let id = id.as_u64().unwrap() as u32;
// Send the response
if let Some(txopt) = self.response_tx.get_mut(&id) {
let tx = txopt.take().unwrap();
let _ = tx.send(res.clone());
self.response_tx.remove(&id);
}
}
Ok(())
}
async fn send_execute(&mut self, command: String, arguments: &Option<serde_json::Value>) -> result::Result<()> {
// Send
let execute = QmpExecute {
execute: command,
id: self.last_response_id,
arguments: arguments.clone()
};
let serialized = serde_json::ser::to_string(&execute)?;
io::write_qmp_line(&mut self.stream, &serialized).await?;
Ok(())
}
/// Actor runloop.
async fn run(mut self) -> result::Result<()> {
loop {
tokio::select! {
str = io::read_qmp_line(&mut self.stream) => {
match str {
Ok(val) => {
let res = serde_json::from_str::<serde_json::Value>(val.as_str()).expect("why it not json fucker bing");
// Check if this is an event
if let Some(event) = res.get("event") {
let str = String::from(event.as_str().unwrap());
// Send the event to the subscriber
if let Some(tx) = self.event_tx.get(&str) {
let _ = tx.send(res).await;
}
}
self.handle_qmp_read(&val).await?;
}
Err(err) => { println!("stream error {err}"); break }
Err(err) => { tracing::error!("stream error {err}"); break }
}
},
msg_opt = self.rx.recv() => {
if let Some(msg) = msg_opt {
self.handle_message(msg).await;
self.handle_message(msg).await?;
} else {
break
}
@ -168,13 +208,31 @@ where
else => break
}
}
Ok(())
}
/// Helper function to spawn the actor.
fn spawn_actor(socket: S) -> mpsc::Sender<QmpActorMessage>
where
S: AsyncReadExt + AsyncWriteExt + Unpin + Send + 'static,
{
let (tx, rx) = mpsc::channel(8);
let inner = QmpClientActor::new(socket, rx);
tokio::spawn(async move {
let res = inner.run().await;
res.inspect_err(|err| {
tracing::error!("error in actor runloop: {err}");
});
});
tx
}
}
/// A client for the Qemu Machine Protocol (also known as QMP).
/// Generic so it works with any Tokio stream type (which fits QEMU's ability to run
/// QMP across many protocols).
///
/// QMP across many protocols). Currently isn't very typesafe but whatever.
///
/// This struct is essentially a handle to an actor.
/// I might maybe refactor this or make some generic "actor" thingmabob but for now
/// it's all in here.
@ -192,12 +250,9 @@ impl QmpClient {
where
S: AsyncReadExt + AsyncWriteExt + Unpin + Send + 'static,
{
let (tx, rx) = mpsc::channel(8);
let inner = QmpClientActor::new(socket, rx);
tokio::spawn(async move { inner.run().await });
Self { tx }
Self {
tx: QmpClientActor::spawn_actor(socket),
}
}
// TODO handle errors properly
@ -205,19 +260,31 @@ impl QmpClient {
pub async fn handshake(&self) -> result::Result<types::QmpHandshake> {
let (tx, rx) = oneshot::channel();
let _ = self.tx
let _ = self
.tx
.send(QmpActorMessage::QmpDoHandshake { tx: tx })
.await;
match rx.await {
Ok(res) => res,
Err(err) => {
println!("???? {err}");
Err(result::QmpError::GeneralFail)
}
Err(err) => Err(result::QmpError::GeneralFail),
}
}
/// Subscribes to a QMP event.
pub async fn execute(&self, command: String, arguments: Option<serde_json::Value>) -> result::Result<serde_json::Value> {
let (tx, rx) = oneshot::channel();
let _ = self
.tx
.send(QmpActorMessage::QmpDoSend { command: command, arguments: arguments.clone(), tx: tx })
.await;
match rx.await {
Ok(res) => Ok(res),
Err(err) => Err(result::QmpError::GeneralFail),
}
}
/// Subscribes to a QMP event.
/// Returns the recvieving arm of a [mpsc::channel] which will recieve
/// the JSON event payloads when an event is sent by the server.
pub async fn subscribe_to_event(
@ -226,7 +293,8 @@ impl QmpClient {
) -> result::Result<mpsc::Receiver<serde_json::Value>> {
let (tx, rx) = mpsc::channel(8);
let _ = self.tx
let _ = self
.tx
.send(QmpActorMessage::QmpSubscribeToEvent {
event_name: event_name,
tx: tx,

View file

@ -1,3 +1,5 @@
//! Low-level IO routines
use tokio::io::{AsyncBufReadExt, AsyncReadExt, AsyncWriteExt, BufStream};
use super::result;
@ -27,9 +29,13 @@ pub async fn write_qmp_line<S>(
where
S: AsyncReadExt + AsyncWriteExt + Unpin + Send,
{
let delimited = format!("{}\n", string);
// rough but whatever
let delimited = format!("{}\r\n", string);
stream.write_all(delimited.as_bytes()).await?;
// FIXME: We probably shouldn't do this all the time but I mean
// QMP isn't that high bandwidth so it's probably fine.
stream.flush().await?;
Ok(())

View file

@ -1,3 +1,5 @@
//! QMP client lib
pub(crate) mod types;
pub mod result;
pub(crate) mod io;

View file

@ -1,6 +1,7 @@
use thiserror::Error;
/// QMP library error.
/// FIXME: more arms
#[derive(Error, Debug)]
pub enum QmpError {
#[error(transparent)]

View file

@ -25,4 +25,16 @@ pub struct QmpHandshakeQMP {
pub struct QmpHandshake {
#[serde(rename = "QMP")]
pub qmp: QmpHandshakeQMP,
}
#[derive(Serialize, Debug)]
pub struct QmpExecute {
pub execute: String,
/// Really, this is defined in the QMP as *any* JSON value,
/// but we only use a u32 here.
pub id: u32,
#[serde(skip_serializing_if = "Option::is_none")]
pub arguments: Option<serde_json::Value>
}