use tokio::io::{AsyncRead, AsyncReadExt, AsyncWrite, AsyncWriteExt};
pub const SERVICE_NAME: &str = "com.apple.preboardservice_v2";
const MAX_PLIST_SIZE: usize = 4 * 1024 * 1024;
#[derive(Debug, thiserror::Error)]
pub enum PreboardError {
#[error("IO error: {0}")]
Io(#[from] std::io::Error),
#[error("plist error: {0}")]
Plist(String),
}
pub struct PreboardClient<S> {
stream: S,
}
impl<S: AsyncRead + AsyncWrite + Unpin> PreboardClient<S> {
pub fn new(stream: S) -> Self {
Self { stream }
}
pub async fn create_stashbag(
&mut self,
manifest: plist::Dictionary,
) -> Result<plist::Dictionary, PreboardError> {
self.send_command("CreateStashbag", manifest).await
}
pub async fn commit_stashbag(
&mut self,
manifest: plist::Dictionary,
) -> Result<plist::Dictionary, PreboardError> {
self.send_command("CommitStashbag", manifest).await
}
async fn send_command(
&mut self,
command: &str,
manifest: plist::Dictionary,
) -> Result<plist::Dictionary, PreboardError> {
let request = plist::Dictionary::from_iter([
(
"Command".to_string(),
plist::Value::String(command.to_string()),
),
("Manifest".to_string(), plist::Value::Dictionary(manifest)),
]);
send_plist(&mut self.stream, &plist::Value::Dictionary(request)).await?;
recv_plist(&mut self.stream).await
}
}
async fn send_plist<S: AsyncWrite + Unpin>(
stream: &mut S,
value: &plist::Value,
) -> Result<(), PreboardError> {
let mut buf = Vec::new();
plist::to_writer_xml(&mut buf, value).map_err(|e| PreboardError::Plist(e.to_string()))?;
stream.write_all(&(buf.len() as u32).to_be_bytes()).await?;
stream.write_all(&buf).await?;
stream.flush().await?;
Ok(())
}
async fn recv_plist<S: AsyncRead + Unpin>(
stream: &mut S,
) -> Result<plist::Dictionary, PreboardError> {
let mut len_buf = [0u8; 4];
stream.read_exact(&mut len_buf).await?;
let len = u32::from_be_bytes(len_buf) as usize;
if len > MAX_PLIST_SIZE {
return Err(PreboardError::Plist(format!(
"plist length {len} exceeds max {MAX_PLIST_SIZE}"
)));
}
let mut buf = vec![0u8; len];
stream.read_exact(&mut buf).await?;
plist::from_bytes(&buf).map_err(|e| PreboardError::Plist(e.to_string()))
}
#[cfg(test)]
mod tests {
use crate::test_util::MockStream;
use super::*;
#[tokio::test]
async fn create_stashbag_sends_manifest() {
let response = plist::Value::Dictionary(plist::Dictionary::new());
let mut stream = MockStream::with_response(response);
let mut client = PreboardClient::new(&mut stream);
client
.create_stashbag(plist::Dictionary::from_iter([(
"Example".to_string(),
plist::Value::Boolean(true),
)]))
.await
.unwrap();
let len = u32::from_be_bytes(stream.written[..4].try_into().unwrap()) as usize;
let payload = &stream.written[4..4 + len];
let dict: plist::Dictionary = plist::from_bytes(payload).unwrap();
assert_eq!(dict["Command"].as_string(), Some("CreateStashbag"));
assert_eq!(
dict["Manifest"]
.as_dictionary()
.and_then(|m| m.get("Example"))
.and_then(plist::Value::as_boolean),
Some(true)
);
}
#[tokio::test]
async fn recv_plist_rejects_oversized_frame() {
let mut read_buf = ((MAX_PLIST_SIZE as u32) + 1).to_be_bytes().to_vec();
read_buf.extend_from_slice(b"ignored");
let mut stream = MockStream::new(read_buf);
let err = recv_plist(&mut stream).await.unwrap_err();
assert!(matches!(err, PreboardError::Plist(message) if message.contains("exceeds max")));
}
}