Fix services error handling on AUTHENTICATE commands

sable_ircd/src/command/handlers/services/sasl.rs

@@ -59,7 +59,7 @@ async fn handle_authenticate(
 
     match services
         .require()?
-        .send_remote_request(authenticate_request.into())
+        .send_remote_request(authenticate_request.clone().into())
         .await
     {
         Ok(RemoteServerResponse::Services(RemoteServicesServerResponse::Authenticate(status))) => {
@@ -95,8 +95,9 @@ async fn handle_authenticate(
                 }
             }
         }
-        _ => {
-            response.numeric(make_numeric!(SaslAborted));
+        msg => {
+            tracing::error!("Unexpected services response to {authenticate_request:?}: {msg:?}");
+            response.numeric(make_numeric!(UnknownError, "Unknown SASL error"));
         }
     }
     Ok(())

sable_ircd/src/messages/numeric.rs

@@ -74,6 +74,7 @@ define_messages! {
     374(EndOfInfo)              => { ()                         => ":End of /INFO list" },
 
 
+    400(UnknownError)           => { (reason: &str)             => ":{reason}" },
     401(NoSuchTarget)           => { (unknown: &str)            => "{unknown} :No such nick/channel" },
     402(NoSuchServer)           => { (server_name: &ServerName) => "{server_name} :No such server" },
     403(NoSuchChannel)          => { (chname: &ChannelName)     => "{chname} :No such channel" },

sable_services/src/server/command/sasl_commands.rs

@@ -23,18 +23,27 @@ impl<DB: DatabaseConnection> ServicesServer<DB> {
     }
 
     pub fn authenticate(&self, session_id: SaslSessionId, data: Vec<u8>) -> CommandResult {
-        let Some(session) = self.sasl_sessions.get(&session_id) else {
+        let session_entry = self.sasl_sessions.entry(session_id);
+        let dashmap::mapref::entry::Entry::Occupied(session_entry) = session_entry else {
             return Ok(Authenticate(Fail).into());
         };
+        let session = session_entry.get();
 
         let Some(mechanism) = self.sasl_mechanisms.get(&session.mechanism) else {
-            self.sasl_sessions.remove(&session_id);
+            session_entry.remove();
             return Ok(Authenticate(Fail).into());
         };
 
-        let response = mechanism.step(self, &session, data)?;
-
-        Ok(Authenticate(response).into())
+        match mechanism.step(self, session, data) {
+            Ok(response) => Ok(Authenticate(response).into()),
+            Err(e) => {
+                tracing::debug!(?session_id, "SASL {} step failed: {e}", mechanism.name());
+                // Equivalent to self.fail_authenticate(session_id) but we can't call it here
+                // because we already have the lock.
+                session_entry.remove();
+                Ok(Authenticate(Fail).into())
+            }
+        }
     }
 
     pub fn abort_authenticate(&self, session_id: SaslSessionId) -> CommandResult {

sable_services/src/server/sasl/mod.rs

@@ -7,6 +7,8 @@ use AuthenticateStatus::*;
 pub type SaslResult = Result<AuthenticateStatus, CommandError>;
 
 pub trait SaslMechanism<DB>: Send + Sync + 'static {
+    fn name(&self) -> String;
+
     fn step(&self, server: &ServicesServer<DB>, session: &SaslSession, data: Vec<u8>)
         -> SaslResult;
 }

sable_services/src/server/sasl/plain.rs

@@ -6,6 +6,10 @@ use sable_network::prelude::*;
 pub struct SaslPlain;
 
 impl<DB: DatabaseConnection> SaslMechanism<DB> for SaslPlain {
+    fn name(&self) -> String {
+        "PLAIN".to_string()
+    }
+
     fn step(
         &self,
         server: &ServicesServer<DB>,