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

Signed-off-by: Vincenzo Palazzo <[email protected]>

Author: vincenzopalazzo

channeld/channeld.c

@@ -971,9 +971,32 @@ 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 a 2 phase communication between
+	 * channeld <-> (metrics/jamming plugin). Because we neeed a way to
+	 * estimate communicate the val in some way and the get the value back
+	 * in order to forward it.
+	 *
+	 * 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`.
+	 **/
 	add_err = channel_add_htlc(peer->channel, REMOTE, id, amount,
 				   cltv_expiry, &payment_hash,
 				   onion_routing_packet, tlvs->blinding_point, &htlc, NULL,
+				   /* We just forward it :) smart ah? */
+				   tlvs->endorsed,
 				   /* We don't immediately fail incoming htlcs,
 				    * instead we wait and fail them after
 				    * they've been committed */
@@ -5230,9 +5253,11 @@ 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;
@@ -5252,22 +5277,23 @@ 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;
 
+	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, 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:

channeld/full_channel.c

@@ -928,6 +928,7 @@ enum channel_add_err channel_add_htlc(struct channel *channel,
 				      const struct pubkey *blinding TAKES,
 				      struct htlc **htlcp,
 				      struct amount_sat *htlc_fee,
+				      const bool endorsed,
 				      bool err_immediate_failures)
 {
 	enum htlc_state state;

channeld/full_channel.h

@@ -138,6 +138,7 @@ enum channel_add_err channel_add_htlc(struct channel *channel,
 				      const struct pubkey *blinding TAKES,
 				      struct htlc **htlcp,
 				      struct amount_sat *htlc_fee,
+				      const bool endorsed,
 				      bool err_immediate_failures);
 
 /**

channeld/test/run-full_channel.c

@@ -168,7 +168,7 @@ static const struct htlc **include_htlcs(struct channel *channel, enum side side
 		memset(&preimage, i, sizeof(preimage));
 		sha256(&hash, &preimage, sizeof(preimage));
 		e = channel_add_htlc(channel, sender, i, msatoshi, 500+i, &hash,
-				     dummy_routing, NULL, NULL, NULL, true);
+				     dummy_routing, NULL, NULL, NULL, false, true);
 		assert(e == CHANNEL_ERR_ADD_OK);
 		htlcs[i] = channel_get_htlc(channel, sender, i);
 	}
@@ -260,7 +260,7 @@ static void send_and_fulfill_htlc(struct channel *channel,
 	sha256(&rhash, &r, sizeof(r));
 
 	assert(channel_add_htlc(channel, sender, 1337, msatoshi, 900, &rhash,
-				dummy_routing, NULL, NULL, NULL, true)
+				dummy_routing, NULL, NULL, NULL, false, true)
 	       == CHANNEL_ERR_ADD_OK);
 	htlc = channel_get_htlc(channel, sender, 1337);
 	assert(htlc);

lightningd/pay.c

@@ -1084,6 +1084,7 @@ send_payment_core(struct lightningd *ld,
 	const struct wallet_payment *old_payment;
 	struct channel *channel;
 	const u8 *failmsg;
+	bool endorsed;
 	struct htlc_out *hout;
 	struct routing_failure *fail;
 	struct command_result *ret;
@@ -1116,9 +1117,22 @@ send_payment_core(struct lightningd *ld,
 		return command_failed(cmd, data);
 	}
 
+
+	/* 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`.
+	 *
+	 * We wait that someone else smarted than me will provide the way to
+	 * calculate it for now it is just a placesolder. */
+	endorsed = false;
 	failmsg = send_onion(tmpctx, ld, packet, first_hop, msat,
 			     rhash, NULL, partid,
-			     group, channel, &hout);
+			     group, channel, &hout, endorsed);
 
 	if (failmsg) {
 		fail = immediate_routing_failure(