fixup! channeld: wip: be able to handle the update htlc by handling the endorsed field

Author: vincenzopalazzo

channeld/channeld.c

@@ -971,9 +971,29 @@ static void handle_peer_add_htlc(struct peer *peer, const u8 *msg)
 		peer_failed_warn(peer->pps, &peer->channel_id,
 				 "Bad peer_add_htlc %s", tal_hex(msg, msg));
 	}
+	/* FIXME(vincenzopalazzo): We should check if the endorse value is zero or missing:
+	 *
+	 * BOLT 2 (0539ad868a263040087d2790684f69fb28d3fa97):
+	 * - if `endorsed` is not provided OR `endorsed` is zero:
+	 *    - MAY choose to limit the liquidity and slots available to forward the
+	 *    corresponding outgoing HTLC in `onion_routing_packet`, if any.*/
+
+	// FIXME(vincenzopalazzo): we should implement the hook to communicate to the
+	// HTLC tlvs to plugins and give a possibility to change it (Wait but this is always safe? mh).
 	add_err = channel_add_htlc(peer->channel, REMOTE, id, amount,
 				   cltv_expiry, &payment_hash,
 				   onion_routing_packet, tlvs->blinding_point, &htlc, NULL,
+				   /* BOLT 2 (0539ad868a263040087d2790684f69fb28d3fa97):
+				    * - otherwise:
+				    *    - if `endorsed` is present and non-zero for the corresponding incoming HTLC
+				    *      AND the incoming peer is considered to have sufficient local reputation
+				    *      (see [Local Reputation](recommendations/local-resource-conservation.md#local-reputation)):
+				    *         - SHOULD set `endorsed` to `1`
+				    *    - otherwise:
+				    *      - SHOULD set `endorsed` to `0`.
+				    *
+				    * FIXME(vincenzopalazzo): We should implement and consult the local reputation
+				    * but currently we just forward it because we should implement the local reputation before.*/
 				   tlvs->endorsed,
 				   /* We don't immediately fail incoming htlcs,
 				    * instead we wait and fail them after
@@ -5231,9 +5251,11 @@ static const u8 *get_cupdate(const struct peer *peer)
 	return peer->channel_update;
 }
 
+/* Offer an HTLC to the remote side. */
 static void handle_offer_htlc(struct peer *peer, const u8 *inmsg)
 {
 	u8 *msg;
+	bool endorsed;
 	u32 cltv_expiry;
 	struct amount_msat amount;
 	struct sha256 payment_hash;
@@ -5253,22 +5275,36 @@ static void handle_offer_htlc(struct peer *peer, const u8 *inmsg)
 					 &cltv_expiry, &payment_hash,
 					 onion_routing_packet, &blinding))
 		master_badmsg(WIRE_CHANNELD_OFFER_HTLC, inmsg);
-
 	if (blinding) {
 		tlvs = tlv_update_add_htlc_tlvs_new(tmpctx);
 		tlvs->blinding_point = tal_dup(tlvs, struct pubkey, blinding);
 	} else
 		tlvs = NULL;
 
+	/* BOLT 2 (0539ad868a263040087d2790684f69fb28d3fa97):
+	 * A sending node:
+	 * - if it is the original source of the HTLC:
+	 *    - if it does not expect immediate fulfillment upon receipt by the
+	 *    final destination:
+	 *       - SHOULD set `endorsed` to `0`.
+	 * - otherwise:
+	 *    - SHOULD set `endorsed` to `1`.
+	 *
+	 * FIXME(vincenzopalazzo): In this case we should consult the metrics, but
+	 * we are not there yet. Also this make me unsure if this is the correct
+	 * place where calculate the endorsed or the endorsed should came from the
+	 * channeld_offer_htlc, maybe in lightnind/pay.c would be better. */
+	endorsed = false;
 	e = channel_add_htlc(peer->channel, LOCAL, peer->htlc_id,
 			     amount, cltv_expiry, &payment_hash,
 			     onion_routing_packet, take(blinding), NULL,
-			     &htlc_fee, false, true);
-	status_debug("Adding HTLC %"PRIu64" amount=%s cltv=%u gave %s",
+			     &htlc_fee, endorsed, true);
+	status_debug("Adding HTLC %"PRIu64" amount=%s cltv=%u gave %s endorsed=%d",
 		     peer->htlc_id,
 		     type_to_string(tmpctx, struct amount_msat, &amount),
 		     cltv_expiry,
-		     channel_add_err_name(e));
+		     channel_add_err_name(e),
+		     endorsed);
 
 	switch (e) {
 	case CHANNEL_ERR_ADD_OK: