Harden embedded transport under UDP churn

src/bin/dosh-server.rs

@@ -28,6 +28,7 @@ use dosh::protocol::{
     TicketAttachBody, TicketAttachEnvelope, TicketAttachOkEnvelope,
 };
 use dosh::pty::{PtyHandle, PtyOutput, adopt_pty_from_fd, spawn_pty_session};
+use dosh::udp::is_transient_udp_send_error;
 use sha2::{Digest, Sha256};
 use std::collections::{BTreeMap, HashMap, HashSet, VecDeque};
 use std::fs;
@@ -1713,52 +1714,6 @@ async fn send_udp(socket: &UdpSocket, packet: &[u8], peer: SocketAddr) -> Result
     }
 }
 
-fn is_transient_udp_send_error(err: &std::io::Error) -> bool {
-    matches!(
-        err.kind(),
-        std::io::ErrorKind::Interrupted
-            | std::io::ErrorKind::TimedOut
-            | std::io::ErrorKind::WouldBlock
-    ) || err.raw_os_error().is_some_and(is_transient_udp_os_error)
-}
-
-#[cfg(unix)]
-fn is_transient_udp_os_error(code: i32) -> bool {
-    matches!(
-        code,
-        libc::EADDRNOTAVAIL
-            | libc::ECONNREFUSED
-            | libc::ECONNRESET
-            | libc::EHOSTDOWN
-            | libc::EHOSTUNREACH
-            | libc::ENETDOWN
-            | libc::ENETRESET
-            | libc::ENETUNREACH
-            | libc::ETIMEDOUT
-    )
-}
-
-#[cfg(windows)]
-fn is_transient_udp_os_error(code: i32) -> bool {
-    matches!(
-        code,
-        10049  // WSAEADDRNOTAVAIL
-            | 10050 // WSAENETDOWN
-            | 10051 // WSAENETUNREACH
-            | 10052 // WSAENETRESET
-            | 10054 // WSAECONNRESET
-            | 10060 // WSAETIMEDOUT
-            | 10061 // WSAECONNREFUSED
-            | 10064 // WSAEHOSTDOWN
-            | 10065 // WSAEHOSTUNREACH
-    )
-}
-
-#[cfg(not(any(unix, windows)))]
-fn is_transient_udp_os_error(_code: i32) -> bool {
-    false
-}
-
 async fn handle_ack(
     state: &Arc<Mutex<ServerState>>,
     peer: SocketAddr,