jsonrpc: uds support for Windows

I could not find a way to get mio 0.7 running with Windows' uds. So,
until tokio-rs/mio#880 (deprecrated/mio-uds#7)
is implemented in Mio we use a simple blocking event loop for Windows.

That's fine, it's just for the RPC. We could potentially see some load
on a server, but it'd be on UNIX so Everything Is Fine ™️.

Signed-off-by: Antoine Poinsot <darosior@protonmail.com>

Cargo.toml

@@ -36,4 +36,7 @@ rusqlite = { version = "0.24.1", features = ["bundled"] }
 # For the JSONRPC API
 jsonrpc-core = "15.1.0"
 jsonrpc-derive = "15.1.0"
+[target.'cfg(not(windows))'.dependencies]
 mio = { version = "0.7.5", features = ["default", "os-poll", "os-util", "uds"] }
+[target.'cfg(windows)'.dependencies]
+uds_windows = "0.1.5"

src/jsonrpc/mod.rs

@@ -8,10 +8,12 @@ use std::{
  time::Duration,
 };
 
-use mio::{
- net::{UnixListener, UnixStream},
- Events, Interest, Poll, Token,
-};
+use mio::{Events, Interest, Poll, Token};
+
+#[cfg(not(windows))]
+use mio::net::{UnixListener, UnixStream};
+#[cfg(windows)]
+use uds_windows::{UnixListener, UnixStream};
 
 const JSONRPC_SERVER: Token = Token(0);
 
@@ -23,17 +25,6 @@ impl RpcApi for RpcImpl {
  }
 }
 
-/// Set up the poller used to listen on the Unix Domain Socket for JSONRPC messages
-pub fn jsonrpcapi_setup(socket_path: PathBuf) -> Result<(Poll, UnixListener), io::Error> {
- // FIXME: permissions! (umask before binding ?)
- let mut listener = UnixListener::bind(&socket_path)?;
- let poll = Poll::new()?;
- poll.registry()
- .register(&mut listener, JSONRPC_SERVER, Interest::READABLE)?;
-
- Ok((poll, listener))
-}
-
 // Remove trailing newlines from utf-8 byte stream
 fn trimmed(mut vec: Vec<u8>, bytes_read: usize) -> Vec<u8> {
  vec.truncate(bytes_read);
@@ -109,11 +100,18 @@ fn handle_byte_stream(
  Ok(())
 }
 
-/// The main event loop for the JSONRPC interface
-pub fn jsonrpcapi_loop(mut poller: Poll, listener: UnixListener) -> Result<(), io::Error> {
+// For all but Windows, we use Mio.
+#[cfg(not(windows))]
+fn mio_loop(
+ mut listener: UnixListener,
+ jsonrpc_io: jsonrpc_core::IoHandler,
+) -> Result<(), io::Error> {
+ let mut poller = Poll::new()?;
  let mut events = Events::with_capacity(16);
- let mut jsonrpc_io = jsonrpc_core::IoHandler::new();
- jsonrpc_io.extend_with(RpcImpl.to_delegate());
+
+ poller
+ .registry()
+ .register(&mut listener, JSONRPC_SERVER, Interest::READABLE)?;
 
  loop {
  poller.poll(&mut events, Some(Duration::from_millis(10000)))?;
@@ -146,3 +144,29 @@ pub fn jsonrpcapi_loop(mut poller: Poll, listener: UnixListener) -> Result<(), i
  }
  }
 }
+
+// For windows, we don't: Mio UDS support for Windows is not yet implemented.
+#[cfg(windows)]
+fn windows_loop(
+ listener: UnixListener,
+ jsonrpc_io: jsonrpc_core::IoHandler,
+) -> Result<(), io::Error> {
+ for stream in listener.incoming() {
+ handle_byte_stream(&jsonrpc_io, stream?)?;
+ }
+
+ Ok(())
+}
+
+/// The main event loop for the JSONRPC interface, polling the UDS at `socket_path`
+pub fn jsonrpcapi_loop(socket_path: PathBuf) -> Result<(), io::Error> {
+ // FIXME: permissions! (umask before binding ?)
+ let listener = UnixListener::bind(&socket_path)?;
+ let mut jsonrpc_io = jsonrpc_core::IoHandler::new();
+ jsonrpc_io.extend_with(RpcImpl.to_delegate());
+
+ #[cfg(not(windows))]
+ return mio_loop(listener, jsonrpc_io);
+ #[cfg(windows)]
+ return windows_loop(listener, jsonrpc_io);
+}

src/main.rs

@@ -8,7 +8,7 @@ use crate::{
  bitcoind::actions::{bitcoind_main_loop, setup_bitcoind},
  config::parse_config,
  database::actions::setup_db,
- jsonrpc::{jsonrpcapi_loop, jsonrpcapi_setup},
+ jsonrpc::jsonrpcapi_loop,
  revaultd::RevaultD,
 };
 
@@ -46,12 +46,9 @@ fn daemon_main(mut revaultd: RevaultD) {
  revaultd.bitcoind_config.network
  );
 
- let (poller, listener) = jsonrpcapi_setup(revaultd.rpc_socket_file()).unwrap_or_else(|e| {
- log::error!("Error setting up the JSONRPC server: {}", e.to_string());
- process::exit(1)
- });
+ let socket_path = revaultd.rpc_socket_file();
  let _jsonrpc_thread = thread::spawn(move || {
- jsonrpcapi_loop(poller, listener).unwrap_or_else(|e| {
+ jsonrpcapi_loop(socket_path).unwrap_or_else(|e| {
  log::error!("Error in JSONRPC server event loop: {}", e.to_string());
  process::exit(1)
  })