engine: apply gossiped network bans to the ircd immediately

A local AKILL/SQLINE/etc. pushes an ADDLINE to the ircd at once, but a ban
arriving by gossip was only held for the next netburst — so a user banned on
one network could keep hopping to peers until their next relink. ingest now
signals BanAdded/BanLifted (all xline kinds), and gossip_ingest pushes the
ADDLINE/DELLINE. Renamed AccountChange to IngestEffect to match its broader
role.

src/engine/db/mod.rs

@@ -883,14 +883,20 @@ impl EventLog {
     }
 }
 
-// What an ingested entry did to a locally-known account, so the engine can log
+// A side-effect an ingested (gossiped) entry needs the engine to carry out on
-// out sessions that were relying on it.
+// the local ircd — the peer only changed shared state, so anything the ircd must
-pub enum AccountChange {
+// be told (log a session out, add/lift a network ban) is signalled back here.
+pub enum IngestEffect {
     TakenOver(String),
     Dropped(String),
     // A gossiped suspension that is now in force: local sessions must be logged
     // out, but the account (and its channels) stay put.
     Suspended(String),
+    // A gossiped network ban (AKILL/SQLINE/…) that must be pushed to the local
+    // ircd now, not just held for the next netburst. `duration` is the remaining
+    // seconds (0 = permanent).
+    BanAdded { kind: String, mask: String, setter: String, duration: u64, reason: String },
+    BanLifted { kind: String, mask: String },
 }
 
 // A fingerprint is hex (hash digest), optionally colon-separated. Bound the
@@ -1022,7 +1028,7 @@ impl Db {
     /// of the gossip seam. Idempotent (re-delivered entries are dropped). Returns
     /// the account name if this ingest changed its owner (a registration conflict
     /// resolved against the local claim), so the caller can log out stale sessions.
-    pub fn ingest(&mut self, entry: LogEntry) -> std::io::Result<Option<AccountChange>> {
+    pub fn ingest(&mut self, entry: LogEntry) -> std::io::Result<Option<IngestEffect>> {
         // Snapshot the incoming account's local owner before applying, to detect a
         // takeover (home changed) or a remote drop (it disappears).
         let watched: Option<(String, Option<String>)> = match &entry.event {
@@ -1036,22 +1042,37 @@ impl Db {
             Event::AccountSuspended { account, .. } => Some(account.clone()),
             _ => None,
         });
+        // A freshly applied network ban must be pushed to the local ircd now.
+        let ban = applied.as_ref().and_then(|e| match e {
+            Event::AkillAdded { kind, mask, setter, reason, expires, .. } => Some(IngestEffect::BanAdded {
+                kind: kind.clone(),
+                mask: mask.clone(),
+                setter: setter.clone(),
+                duration: (*expires).map(|x| x.saturating_sub(now())).unwrap_or(0),
+                reason: reason.clone(),
+            }),
+            Event::AkillRemoved { kind, mask } => Some(IngestEffect::BanLifted { kind: kind.clone(), mask: mask.clone() }),
+            _ => None,
+        });
         if let Some(event) = applied {
             apply(&mut self.accounts, &mut self.channels, &mut self.grouped, &mut self.bots, &mut self.host_cfg, &mut self.net, event);
         }
         if let Some((name, prev_home)) = watched {
             match (prev_home, self.account(&name).map(|c| c.home.clone())) {
-                (Some(prev), Some(cur)) if cur != prev => return Ok(Some(AccountChange::TakenOver(name))),
+                (Some(prev), Some(cur)) if cur != prev => return Ok(Some(IngestEffect::TakenOver(name))),
-                (Some(_), None) => return Ok(Some(AccountChange::Dropped(name))),
+                (Some(_), None) => return Ok(Some(IngestEffect::Dropped(name))),
                 _ => {}
             }
         }
         if let Some(account) = suspended {
             // Only if the suspension is actually in force (not an already-expired one).
             if self.is_suspended(&account) {
-                return Ok(Some(AccountChange::Suspended(account)));
+                return Ok(Some(IngestEffect::Suspended(account)));
             }
         }
+        if let Some(effect) = ban {
+            return Ok(Some(effect));
+        }
         Ok(None)
     }
 

src/engine/mod.rs

@@ -461,20 +461,30 @@ impl Engine {
         // If ingesting a peer's entry removed an account a local session or channel
         // relied on (lost a conflict, or dropped elsewhere), clean up after it.
         let gone = match self.db.ingest(entry)? {
-            Some(db::AccountChange::TakenOver(a)) => {
+            Some(db::IngestEffect::TakenOver(a)) => {
                 self.handle_account_gone(&a, "collided with another network and no longer belongs to you");
                 true
             }
-            Some(db::AccountChange::Dropped(a)) => {
+            Some(db::IngestEffect::Dropped(a)) => {
                 self.handle_account_gone(&a, "was dropped");
                 true
             }
-            Some(db::AccountChange::Suspended(a)) => {
+            Some(db::IngestEffect::Suspended(a)) => {
                 // A gossiped suspension keeps the account and its channels, but its
                 // live sessions here must end (a local SUSPEND logs them out too).
                 self.logout_account_sessions(&a, "was suspended");
                 false
             }
+            Some(db::IngestEffect::BanAdded { kind, mask, setter, duration, reason }) => {
+                // Push the gossiped network ban to our ircd now, rather than only
+                // holding it for the next netburst.
+                self.emit_irc(NetAction::AddLine { kind, mask, setter, duration, reason });
+                false
+            }
+            Some(db::IngestEffect::BanLifted { kind, mask }) => {
+                self.emit_irc(NetAction::DelLine { kind, mask });
+                false
+            }
             None => false,
         };
         // handle_account_gone may have released a channel that had a bot assigned.

src/engine/tests.rs

@@ -469,6 +469,37 @@
         assert!(told, "the user is told they were suspended");
     }
 
+    // A network ban that arrives by gossip is pushed to the local ircd right
+    // away, not just held for the next netburst — otherwise a banned user could
+    // hop to a peer network until its next relink.
+    #[test]
+    fn gossiped_network_ban_is_pushed_to_the_ircd() {
+        use echo_nickserv::NickServ;
+        let path = std::env::temp_dir().join("echo-gossipban.jsonl");
+        let _ = std::fs::remove_file(&path);
+        let db = Db::open(&path, "test");
+        let mut e = Engine::new(vec![Box::new(NickServ { uid: "42SAAAAAA".into(), guest_nick: "Guest".into(), guest_seq: 0 })], db);
+        e.set_sid("42S".into());
+        let (tx, mut rx) = tokio::sync::mpsc::unbounded_channel();
+        e.set_irc_out(tx);
+
+        // A peer sets a permanent G-line; it must be applied to our ircd now.
+        e.gossip_ingest(LogEntry::for_test("peer", 0, 1, db::Event::AkillAdded {
+            kind: "G".into(), mask: "*@evil.example".into(), setter: "peer-oper".into(), reason: "spam".into(), ts: 0, expires: None,
+        })).unwrap();
+        let added = std::iter::from_fn(|| rx.try_recv().ok())
+            .any(|a| matches!(a, NetAction::AddLine { kind, mask, duration, .. } if kind == "G" && mask == "*@evil.example" && duration == 0));
+        assert!(added, "gossiped ban pushed to the ircd immediately");
+
+        // A peer lifts it; the ircd is told to drop the line.
+        e.gossip_ingest(LogEntry::for_test("peer", 1, 2, db::Event::AkillRemoved {
+            kind: "G".into(), mask: "*@evil.example".into(),
+        })).unwrap();
+        let lifted = std::iter::from_fn(|| rx.try_recv().ok())
+            .any(|a| matches!(a, NetAction::DelLine { kind, mask } if kind == "G" && mask == "*@evil.example"));
+        assert!(lifted, "gossiped ban lift removes the line from the ircd");
+    }
+
     // Losing a registration conflict logs out the local session on that name and
     // notifies them over the services-initiated outbound path.
     #[test]