dictserv: opt-in DICT (RFC 2229) lookup service — bots and /msg answer dict/define/thes/acronym/law/etc via dict.org off-reactor

src/engine/dispatch.rs

@@ -101,10 +101,20 @@ impl Engine {
         out.extend(self.reconcile_bots());
         // Announce whatever this command changed to the staff audit channel.
         out.extend(self.audit_feed(audit_mark, &nick, account.as_deref()));
+        self.apply_dict_limit(&mut out);
         self.apply_msg_style(&mut out);
         out
     }
 
+    // Drop DICT lookups that exceed the global rate budget, so a burst of !dict
+    // can't hammer the dictionary server. Non-lookup actions pass untouched, and
+    // the limiter is only consulted when a lookup is actually present.
+    fn apply_dict_limit(&mut self, out: &mut Vec<NetAction>) {
+        if out.iter().any(|a| matches!(a, NetAction::DictLookup { .. })) {
+            out.retain(|a| !matches!(a, NetAction::DictLookup { .. }) || self.dict_limiter.allow());
+        }
+    }
+
     // Rewrite each service→user NOTICE to a server-notice (sourced from our
     // server) for users who opted into SET SNOTICE; everyone else keeps a normal
     // notice from the pseudoclient. A multi-line reply names the service once, on
@@ -157,6 +167,19 @@ impl Engine {
             return;
         }
 
+        // A dictionary command (!dict/!define/…) becomes a deferred DICT lookup the
+        // assigned bot speaks — only when DictServ is loaded. The rate limiter in
+        // dispatch() drops excess lookups so nobody can hammer the DICT server.
+        if let Some(l) = echo_dictserv::lookup_for(cmd) {
+            if self.service_uid("DictServ").is_some() {
+                let query = words.collect::<Vec<_>>().join(" ");
+                if !query.trim().is_empty() {
+                    ctx.dict_lookup(botuid.as_str(), chan, l.database, l.label, query);
+                }
+            }
+            return;
+        }
+
         let Some(csuid) = self.service_uid("ChanServ") else { return };
         // Rewrite `!cmd args…` into `CMD #channel args…` for ChanServ.
         let mark = ctx.actions.len();