Add exclude option to pay

common/json_tok.c

@@ -10,6 +10,7 @@
 #include <common/json_command.h>
 #include <common/json_helpers.h>
 #include <common/json_tok.h>
+#include <common/route.h>
 
 struct command_result *param_array(struct command *cmd, const char *name,
 				   const char *buffer, const jsmntok_t *tok,
@@ -649,6 +650,64 @@ param_routehint_array(struct command *cmd, const char *name, const char *buffer,
 	return NULL;
 }
 
+struct command_result *param_route_exclusion(struct command *cmd,
+					const char *name, const char *buffer, const jsmntok_t *tok,
+					struct route_exclusion **re)
+{
+	*re = tal(cmd, struct route_exclusion);
+	struct short_channel_id_dir *chan_id =
+					tal(tmpctx, struct short_channel_id_dir);
+	if (!short_channel_id_dir_from_str(buffer + tok->start,
+						tok->end - tok->start,
+						chan_id)) {
+		struct node_id *node_id = tal(tmpctx, struct node_id);
+
+		if (!json_to_node_id(buffer, tok, node_id))
+			return command_fail_badparam(cmd, "exclude",
+								buffer, tok,
+								"should be short_channel_id_dir or node_id");
+
+		(*re)->type = EXCLUDE_NODE;
+		(*re)->u.node_id = *node_id;
+	} else {
+		(*re)->type = EXCLUDE_CHANNEL;
+		(*re)->u.chan_id = *chan_id;
+	}
+
+	return NULL;
+}
+
+struct command_result *
+param_route_exclusion_array(struct command *cmd, const char *name,
+					const char *buffer, const jsmntok_t *tok,
+					struct route_exclusion ***res)
+{
+	size_t i;
+	const jsmntok_t *curr;
+	char *element_name;
+	struct command_result *err;
+	if (tok->type != JSMN_ARRAY) {
+		return command_fail(
+		    cmd, JSONRPC2_INVALID_PARAMS,
+		    "Exclude array %s (\"%s\") is not an array",
+		    name, json_strdup(tmpctx, buffer, tok));
+	}
+
+	*res = tal_arr(cmd, struct route_exclusion *, 0);
+	json_for_each_arr(i, curr, tok) {
+		struct route_exclusion *element;
+		element_name = tal_fmt(cmd, "%s[%zu]", name, i);
+		err = param_route_exclusion(cmd, element_name, buffer, curr, &element);
+		if (err != NULL) {
+			return err;
+		}
+		tal_arr_expand(res, element);
+
+		tal_free(element_name);
+	}
+	return NULL;
+}
+
 struct command_result *param_lease_hex(struct command *cmd,
 				       const char *name,
 				       const char *buffer,

common/json_tok.h

@@ -18,6 +18,7 @@ struct channel_id;
 struct command;
 struct command_result;
 struct json_escape;
+struct route_exclusion;
 struct sha256;
 struct wally_psbt;
 
@@ -205,6 +206,15 @@ struct command_result *
 param_routehint_array(struct command *cmd, const char *name, const char *buffer,
 		      const jsmntok_t *tok, struct route_info ***ris);
 
+struct command_result *param_route_exclusion(struct command *cmd,
+					const char *name, const char *buffer, const jsmntok_t *tok,
+					struct route_exclusion **re);
+
+struct command_result *
+param_route_exclusion_array(struct command *cmd, const char *name,
+					const char *buffer, const jsmntok_t *tok,
+					struct route_exclusion ***res);
+
 /**
  * Parse a 'compact-lease' (serialized lease_rates) back into lease_rates
  */

common/route.h

@@ -74,4 +74,22 @@ struct route_hop *route_from_dijkstra(const tal_t *ctx,
 				      const struct gossmap_node *src,
 				      struct amount_msat final_amount,
 				      u32 final_cltv);
+
+/*
+ * Manually exlude nodes or channels from a route.
+ * Used with `getroute` and `pay` commands
+ */
+enum route_exclusion_type {
+	EXCLUDE_CHANNEL = 1,
+	EXCLUDE_NODE = 2
+};
+
+struct route_exclusion {
+	enum route_exclusion_type type;
+	union {
+		struct short_channel_id_dir chan_id;
+		struct node_id node_id;
+	} u;
+};
+
 #endif /* LIGHTNING_COMMON_ROUTE_H */

contrib/pyln-client/pyln/client/lightning.py

@@ -616,7 +616,7 @@ def dev_memleak(self):
 
     def dev_pay(self, bolt11, msatoshi=None, label=None, riskfactor=None,
                 maxfeepercent=None, retry_for=None,
-                maxdelay=None, exemptfee=None, use_shadow=True):
+                maxdelay=None, exemptfee=None, use_shadow=True, exclude=[]):
         """
         A developer version of `pay`, with the possibility to deactivate
         shadow routing (used for testing).
@@ -631,6 +631,7 @@ def dev_pay(self, bolt11, msatoshi=None, label=None, riskfactor=None,
             "maxdelay": maxdelay,
             "exemptfee": exemptfee,
             "use_shadow": use_shadow,
+            "exclude": exclude,
         }
         return self.call("pay", payload)
 
@@ -989,7 +990,7 @@ def newaddr(self, addresstype=None):
 
     def pay(self, bolt11, msatoshi=None, label=None, riskfactor=None,
             maxfeepercent=None, retry_for=None,
-            maxdelay=None, exemptfee=None):
+            maxdelay=None, exemptfee=None, exclude=[]):
         """
         Send payment specified by {bolt11} with {msatoshi}
         (ignored if {bolt11} has an amount), optional {label}
@@ -1004,6 +1005,7 @@ def pay(self, bolt11, msatoshi=None, label=None, riskfactor=None,
             "retry_for": retry_for,
             "maxdelay": maxdelay,
             "exemptfee": exemptfee,
+            "exclude": exclude,
         }
         return self.call("pay", payload)
 

doc/lightning-pay.7.md

@@ -6,6 +6,7 @@ SYNOPSIS
 
 **pay** *bolt11* \[*msatoshi*\] \[*label*\] \[*riskfactor*\]
 \[*maxfeepercent*\] \[*retry\_for*\] \[*maxdelay*\] \[*exemptfee*\]
+\[*exclude*\]
 
 DESCRIPTION
 -----------
@@ -40,6 +41,11 @@ finding routes and retrying the payment. However, a payment may be
 delayed for up to `maxdelay` blocks by another node; clients should be
 prepared for this worst case.
 
+*exclude* is a JSON array of short-channel-id/direction (e.g. \[
+"564334x877x1/0", "564195x1292x0/1" \]) or node-id which should be excluded
+from consideration for routing. The default is not to exclude any channels
+or nodes.
+
 When using *lightning-cli*, you may skip optional parameters by using
 *null*. Alternatively, use **-k** option to provide parameters by name.
 

plugins/libplugin-pay.c

@@ -3885,3 +3885,45 @@ static void payee_incoming_limit_step_cb(void *d UNUSED, struct payment *p)
 
 REGISTER_PAYMENT_MODIFIER(payee_incoming_limit, void *, NULL,
 			  payee_incoming_limit_step_cb);
+
+static struct route_exclusions_data *
+route_exclusions_data_init(struct payment *p)
+{
+	struct route_exclusions_data *d;
+	if (p->parent != NULL) {
+		return payment_mod_route_exclusions_get_data(p->parent);
+	} else {
+		d = tal(p, struct route_exclusions_data);
+		d->exclusions = NULL;
+	}
+	return d;
+}
+
+static void route_exclusions_step_cb(struct route_exclusions_data *d,
+		struct payment *p)
+{
+	if (p->parent)
+		return payment_continue(p);
+	struct route_exclusion **exclusions = d->exclusions;
+	for (size_t i = 0; i < tal_count(exclusions); i++) {
+		struct route_exclusion *e = exclusions[i];
+		if (e->type == EXCLUDE_CHANNEL) {
+			channel_hints_update(p, e->u.chan_id.scid, e->u.chan_id.dir,
+				false, false, NULL, NULL);
+		} else {
+			if (node_id_eq(&e->u.node_id, p->destination)) {
+				payment_abort(p, "Payee is manually excluded");
+				return;
+			} else if (node_id_eq(&e->u.node_id, p->local_id)) {
+				payment_abort(p, "Payer is manually excluded");
+				return;
+			}
+
+			tal_arr_expand(&p->excluded_nodes, e->u.node_id);
+		}
+	}
+	payment_continue(p);
+}
+
+REGISTER_PAYMENT_MODIFIER(route_exclusions, struct route_exclusions_data *,
+	route_exclusions_data_init, route_exclusions_step_cb);

plugins/libplugin-pay.h

@@ -406,6 +406,10 @@ struct adaptive_split_mod_data {
 	u32 htlc_budget;
 };
 
+struct route_exclusions_data {
+	struct route_exclusion **exclusions;
+};
+
 /* List of globally available payment modifiers. */
 REGISTER_PAYMENT_MODIFIER_HEADER(retry, struct retry_mod_data);
 REGISTER_PAYMENT_MODIFIER_HEADER(routehints, struct routehints_data);
@@ -426,6 +430,8 @@ REGISTER_PAYMENT_MODIFIER_HEADER(local_channel_hints, void);
  * we detect the payee to have, in order to not exhaust the number of HTLCs
  * each of those channels can bear.  */
 REGISTER_PAYMENT_MODIFIER_HEADER(payee_incoming_limit, void);
+REGISTER_PAYMENT_MODIFIER_HEADER(route_exclusions, struct route_exclusions_data);
+
 
 struct payment *payment_new(tal_t *ctx, struct command *cmd,
 			    struct payment *parent,

plugins/pay.c

@@ -2255,7 +2255,14 @@ payment_listsendpays_previous(struct command *cmd, const char *buf,
 }
 
 struct payment_modifier *paymod_mods[] = {
+	/* NOTE: The order in which these four paymods are executed is
+	 * significant!
+	 * local_channel_hints *must* execute first before route_exclusions
+	 * which *must* execute before directpay.
+	 * exemptfee *must* also execute before directpay.
+	 */
 	&local_channel_hints_pay_mod,
+	&route_exclusions_pay_mod,
 	&exemptfee_pay_mod,
 	&directpay_pay_mod,
 	&shadowroute_pay_mod,
@@ -2305,6 +2312,7 @@ static struct command_result *json_paymod(struct command *cmd,
 	struct sha256 *local_offer_id;
 	const struct tlv_invoice *b12;
 	struct out_req *req;
+	struct route_exclusion **exclusions;
 #if DEVELOPER
 	bool *use_shadow;
 #endif
@@ -2326,6 +2334,7 @@ static struct command_result *json_paymod(struct command *cmd,
 			     maxdelay_default),
 		   p_opt_def("exemptfee", param_msat, &exemptfee, AMOUNT_MSAT(5000)),
 		   p_opt("localofferid", param_sha256, &local_offer_id),
+		   p_opt("exclude", param_route_exclusion_array, &exclusions),
 #if DEVELOPER
 		   p_opt_def("use_shadow", param_bool, &use_shadow, true),
 #endif
@@ -2479,6 +2488,7 @@ static struct command_result *json_paymod(struct command *cmd,
 	shadow_route = payment_mod_shadowroute_get_data(p);
 	payment_mod_presplit_get_data(p)->disable = disablempp;
 	payment_mod_adaptive_splitter_get_data(p)->disable = disablempp;
+	payment_mod_route_exclusions_get_data(p)->exclusions = exclusions;
 
 	/* This is an MPP enabled pay command, disable amount fuzzing. */
 	shadow_route->fuzz_amount = false;

plugins/topology.c

@@ -30,19 +30,6 @@ static struct gossmap *get_gossmap(void)
 /* Convenience global since route_score_fuzz doesn't take args. 0 to 1. */
 static double fuzz;
 
-enum exclude_entry_type {
-	EXCLUDE_CHANNEL = 1,
-	EXCLUDE_NODE = 2
-};
-
-struct exclude_entry {
-	enum exclude_entry_type type;
-	union {
-		struct short_channel_id_dir chan_id;
-		struct node_id node_id;
-	} u;
-};
-
 /* Prioritize costs over distance, but with fuzz.  Cost must be
  * the same when the same channel queried, so we base it on that. */
 static u64 route_score_fuzz(u32 distance,
@@ -68,7 +55,7 @@ static bool can_carry(const struct gossmap *map,
 		      const struct gossmap_chan *c,
 		      int dir,
 		      struct amount_msat amount,
-		      const struct exclude_entry **excludes)
+		      struct route_exclusion **excludes)
 {
 	struct node_id dstid;
 
@@ -143,12 +130,11 @@ static struct command_result *json_getroute(struct command *cmd,
 {
 	struct node_id *destination;
 	struct node_id *source;
-	const jsmntok_t *excludetok;
 	struct amount_msat *msat;
 	u32 *cltv;
 	/* risk factor 12.345% -> riskfactor_millionths = 12345000 */
 	u64 *riskfactor_millionths, *fuzz_millionths;
-	const struct exclude_entry **excluded;
+	struct route_exclusion **excluded;
 	u32 *max_hops;
 	const struct dijkstra *dij;
 	struct route_hop *route;
@@ -164,7 +150,7 @@ static struct command_result *json_getroute(struct command *cmd,
 		   p_opt_def("fromid", param_node_id, &source, local_id),
 		   p_opt_def("fuzzpercent", param_millionths, &fuzz_millionths,
 			     5000000),
-		   p_opt("exclude", param_array, &excludetok),
+		   p_opt("exclude", param_route_exclusion_array, &excluded),
 		   p_opt_def("maxhops", param_number, &max_hops, ROUTING_MAX_HOPS),
 		   NULL))
 		return command_param_failed();
@@ -176,38 +162,6 @@ static struct command_result *json_getroute(struct command *cmd,
 					     buffer, params,
 					     "should be <= 100");
 
-	if (excludetok) {
-		const jsmntok_t *t;
-		size_t i;
-
-		excluded = tal_arr(cmd, const struct exclude_entry *, 0);
-
-		json_for_each_arr(i, t, excludetok) {
-			struct exclude_entry *entry = tal(excluded, struct exclude_entry);
-			struct short_channel_id_dir *chan_id = tal(tmpctx, struct short_channel_id_dir);
-			if (!short_channel_id_dir_from_str(buffer + t->start,
-							   t->end - t->start,
-							   chan_id)) {
-				struct node_id *node_id = tal(tmpctx, struct node_id);
-
-				if (!json_to_node_id(buffer, t, node_id))
-					return command_fail_badparam(cmd, "exclude",
-								     buffer, t,
-								     "should be short_channel_id or node_id");
-
-				entry->type = EXCLUDE_NODE;
-				entry->u.node_id = *node_id;
-			} else {
-				entry->type = EXCLUDE_CHANNEL;
-				entry->u.chan_id = *chan_id;
-			}
-
-			tal_arr_expand(&excluded, entry);
-		}
-	} else {
-		excluded = NULL;
-	}
-
 	gossmap = get_gossmap();
 	src = gossmap_find_node(gossmap, source);
 	if (!src)