1 files changed, 33 insertions, 11 deletions
diff --git a/names/server.js b/names/server.js
index f2a9f41..a9ade90 100644
--- a/names/server.js
+++ b/names/server.js
@@ -388,20 +388,42 @@ const HOLD_KEYS = new Set(['a7fc7e2cbc16949c411a982fe6cecec0c1674fb4dabbdce57027
 // delivered once is never delivered again — the record is saved before
 // anything else happens.
 const delivering = new Set();
+// Past this many sats delivered to one key within an hour, the next ones
+// wait in the queue for a person (the monitor pages on a queue older than
+// 30 min): a bug we haven't found yet costs at most this much per key.
+const VELOCITY = { windowMs: 3600_000, maxSat: 1_500_000 };
 async function forward(name, sat, hash, pubkey) {
-  if (hash && state.delivered?.[hash]) { log(`forward: ${hash.slice(0, 12)} was already delivered — not again`); return; }
-  if (hash && delivering.has(hash)) throw new Error('already being delivered');
-  if (hash) delivering.add(hash);
+  if (!hash) throw Object.assign(new Error('no payment hash — refusing to deliver'), { permanent: true });
+  if (state.delivered?.[hash]) { log(`forward: ${hash.slice(0, 12)} was already delivered — not again`); return; }
+  if (delivering.has(hash)) throw new Error('already being delivered');
+  delivering.add(hash);
   try {
-    await forwardOnce(name, sat, hash, pubkey);
-    if (hash) {
-      const all = state.delivered ||= {};
-      all[hash] = Date.now();
-      const cutoff = Date.now() - 60 * 86400_000;
-      for (const [h, t] of Object.entries(all)) if (t < cutoff) delete all[h];
-      persist();
+    // Every delivery is backed by a payment that really arrived: our node's
+    // own invoice for this hash, paid, for at least this much. Whatever
+    // path got here (settle loop, retry, operator), nothing goes out that
+    // didn't come in.
+    const inv = ln && (await ln.call('listinvoices', { payment_hash: hash })).invoices?.[0];
+    const got = Math.floor(Number(inv?.amount_received_msat?.msat ?? inv?.amount_received_msat ?? 0) / 1000);
+    if (!inv || inv.status !== 'paid' || got < sat) {
+      throw Object.assign(new Error(`no paid invoice of ${sat} sat behind ${hash.slice(0, 12)} (${inv ? inv.status + ' ' + got : 'none'}) — refusing`), { permanent: true });
+    }
+    const key = pubkey || state.names[name]?.pubkey || name;
+    const recent = Object.values(state.deliveredTo?.[key] || {}).filter((x) => x.at > Date.now() - VELOCITY.windowMs);
+    const lastHour = recent.reduce((n, x) => n + x.sat, 0);
+    if (lastHour + sat > VELOCITY.maxSat) {
+      log(`ALERT forward velocity: ${key.slice(0, 12)} (${name}) got ${lastHour} sat in the last hour; ${sat} more waits for a person`);
+      throw new Error(`velocity hold: ${lastHour} sat delivered to this key in the last hour`);
     }
-  } finally { if (hash) delivering.delete(hash); }
+    await forwardOnce(name, sat, hash, pubkey);
+    const all = state.delivered ||= {};
+    all[hash] = Date.now();
+    const cutoff = Date.now() - 60 * 86400_000;
+    for (const [h, t] of Object.entries(all)) if (t < cutoff) delete all[h];
+    const mine = (state.deliveredTo ||= {})[key] ||= {};
+    mine[hash] = { sat, at: Date.now() };
+    for (const [h, x] of Object.entries(mine)) if (x.at < Date.now() - VELOCITY.windowMs) delete mine[h];
+    persist();
+  } finally { delivering.delete(hash); }
 }
 
 async function forwardOnce(name, sat, hash, pubkey) {