renepay: handle non-MPP invoices

Changelog-Fixed: renepay: Now able to handle invoices that don't support Multi-Path-Payments.

Signed-off-by: Lagrang3 <[email protected]>

Author: Lagrang3

plugins/renepay/mods.c

@@ -587,6 +587,8 @@ static struct command_result *getroutes_cb(struct payment *payment)
 	json_add_string(req->js, NULL, "auto.sourcefree");
 	json_add_string(req->js, NULL, payment->payment_layer);
 	json_add_string(req->js, NULL, RENEPAY_LAYER);
+	if (!payment->payment_info.use_mpp)
+		json_add_string(req->js, NULL, "auto.no_mpp_support");
 	json_array_end(req->js);
 	// FIXME: add further constraints here if necessary when they become
 	// available in getroutes

plugins/renepay/payment.c

@@ -108,7 +108,8 @@ bool payment_set_constraints(
 		u64 min_prob_success_millionths,
 		u64 base_prob_success_millionths,
 		bool use_shadow,
-		const struct route_exclusion **exclusions)
+		const struct route_exclusion **exclusions,
+		bool mpp_enabled)
 {
 	// FIXME: add exclusions to a layer
 	assert(p);
@@ -129,6 +130,7 @@ bool payment_set_constraints(
 	pinfo->min_prob_success = min_prob_success_millionths / 1e6;
 	pinfo->base_prob_success = base_prob_success_millionths / 1e6;
 	pinfo->use_shadow = use_shadow;
+	pinfo->use_mpp = mpp_enabled;
 
 	return true;
 }

plugins/renepay/payment.h

@@ -122,7 +122,8 @@ bool payment_set_constraints(
 		u64 min_prob_success_millionths,
 		u64 base_prob_success_millionths,
 		bool use_shadow,
-		const struct route_exclusion **exclusions);
+		const struct route_exclusion **exclusions,
+		bool mpp_enabled);
 
 bool payment_refresh(struct payment *p);
 

plugins/renepay/payment_info.h

@@ -86,6 +86,9 @@ struct payment_info {
 
 	/* --developer allows disabling shadow route */
 	bool use_shadow;
+
+	/* Use Multi-Path-Payments feature. */
+	bool use_mpp;
 };
 
 #endif /* LIGHTNING_PLUGINS_RENEPAY_PAYMENT_INFO_H */

plugins/renepay/renepay.c

@@ -181,6 +181,7 @@ static struct command_result *json_renepay(struct command *cmd, const char *buf,
 	const char *description;
 	const char *label;
 	struct route_exclusion **exclusions;
+	bool mpp_enabled = true;
 
 	// dev options
 	bool *use_shadow;
@@ -262,6 +263,8 @@ static struct command_result *json_renepay(struct command *cmd, const char *buf,
 			*inv_msat = amount_msat(*b12->invoice_amount);
 		}
 		payment_hash = b12->invoice_payment_hash;
+		mpp_enabled =
+		    feature_offered(b12->invoice_features, OPT_BASIC_MPP);
 	} else {
 		b11 = bolt11_decode(tmpctx, invstr,
 				    plugin_feature_set(cmd->plugin),
@@ -280,6 +283,7 @@ static struct command_result *json_renepay(struct command *cmd, const char *buf,
 		inv_msat = b11->msat;
 		invexpiry = b11->timestamp + b11->expiry;
 		payment_hash = &b11->payment_hash;
+		mpp_enabled = feature_offered(b11->features, OPT_BASIC_MPP);
 	}
 
 	/* === Set default values for non-trivial constraints  === */
@@ -396,7 +400,8 @@ static struct command_result *json_renepay(struct command *cmd, const char *buf,
 			*min_prob_success_millionths,
 			*base_prob_success_millionths, use_shadow,
 			cast_const2(const struct route_exclusion **,
-				    exclusions)) ||
+				    exclusions),
+			mpp_enabled) ||
 		    !payment_refresh(payment))
 			return command_fail(
 			    cmd, PLUGIN_ERROR,
@@ -431,7 +436,8 @@ static struct command_result *json_renepay(struct command *cmd, const char *buf,
 			*min_prob_success_millionths,
 			*base_prob_success_millionths, use_shadow,
 			cast_const2(const struct route_exclusion **,
-				    exclusions)) ||
+				    exclusions),
+			mpp_enabled) ||
 		    !payment_refresh(payment))
 			return command_fail(
 			    cmd, PLUGIN_ERROR,