sendpay: optional argument to link local offer.

This is for offers which have `send_invoice`: we need to associate the
payment with the original offer, in (the usual) case where it is a single
use offer.  We mark it used when it's paid, to avoid a race.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

common/jsonrpc_errors.h

@@ -41,6 +41,7 @@ static const errcode_t PAY_NO_SUCH_PAYMENT = 208;
 static const errcode_t PAY_UNSPECIFIED_ERROR = 209;
 static const errcode_t PAY_STOPPED_RETRYING = 210;
 static const errcode_t PAY_STATUS_UNEXPECTED = 211;
+static const errcode_t PAY_OFFER_INVALID = 212;
 
 /* `fundchannel` or `withdraw` errors */
 static const errcode_t FUND_MAX_EXCEEDED = 300;

lightningd/pay.c

@@ -334,6 +334,10 @@ void payment_succeeded(struct lightningd *ld, struct htlc_out *hout,
 					 hout->partid);
 	assert(payment);
 
+#if EXPERIMENTAL_FEATURES
+	if (payment->local_offer_id)
+		wallet_offer_mark_used(ld->wallet->db, payment->local_offer_id);
+#endif
 	tell_waiters_success(ld, &hout->payment_hash, payment);
 }
 
@@ -789,6 +793,60 @@ static const u8 *send_onion(const tal_t *ctx, struct lightningd *ld,
 			     &dont_care_about_channel_update);
 }
 
+#if EXPERIMENTAL_FEATURES
+static struct command_result *check_offer_usage(struct command *cmd,
+						const struct sha256 *local_offer_id)
+{
+	enum offer_status status;
+	const struct wallet_payment **payments;
+
+	if (!local_offer_id)
+		return NULL;
+
+	if (!wallet_offer_find(tmpctx, cmd->ld->wallet, local_offer_id,
+			       NULL, &status))
+		return command_fail(cmd, PAY_OFFER_INVALID,
+				    "Unknown offer %s",
+				    type_to_string(tmpctx, struct sha256,
+						   local_offer_id));
+
+	if (!offer_status_active(status))
+		return command_fail(cmd, PAY_OFFER_INVALID,
+				    "Inactive offer %s",
+				    type_to_string(tmpctx, struct sha256,
+						   local_offer_id));
+
+	if (!offer_status_single(status))
+		return NULL;
+
+	/* OK, we must not attempt more than one payment at once for
+	 * single_use offer */
+	payments = wallet_payments_by_offer(tmpctx, cmd->ld->wallet, local_offer_id);
+	for (size_t i = 0; i < tal_count(payments); i++) {
+		switch (payments[i]->status) {
+		case PAYMENT_COMPLETE:
+			return command_fail(cmd, PAY_OFFER_INVALID,
+					    "Single-use offer already paid"
+					    " with %s",
+					    type_to_string(tmpctx, struct sha256,
+							   &payments[i]
+							   ->payment_hash));
+		case PAYMENT_PENDING:
+			return command_fail(cmd, PAY_OFFER_INVALID,
+					    "Single-use offer already"
+					    " in progress with %s",
+					    type_to_string(tmpctx, struct sha256,
+							   &payments[i]
+							   ->payment_hash));
+		case PAYMENT_FAILED:
+			break;
+		}
+	}
+
+	return NULL;
+}
+#endif /* EXPERIMENTAL_FEATURES */
+
 /* destination/route_channels/route_nodes are NULL (and path_secrets may be NULL)
  * if we're sending a raw onion. */
 static struct command_result *
@@ -805,7 +863,8 @@ send_payment_core(struct lightningd *ld,
 		  const struct node_id *destination,
 		  struct node_id *route_nodes TAKES,
 		  struct short_channel_id *route_channels TAKES,
-		  struct secret *path_secrets)
+		  struct secret *path_secrets,
+		  const struct sha256 *local_offer_id)
 {
 	const struct wallet_payment **payments, *old_payment = NULL;
 	struct channel *channel;
@@ -942,6 +1001,13 @@ send_payment_core(struct lightningd *ld,
 						   &total_msat));
 	}
 
+#if EXPERIMENTAL_FEATURES
+	struct command_result *offer_err;
+	offer_err = check_offer_usage(cmd, local_offer_id);
+	if (offer_err)
+		return offer_err;
+#endif
+
 	channel = active_channel_by_id(ld, &first_hop->nodeid, NULL);
 	if (!channel) {
 		struct json_stream *data
@@ -1016,6 +1082,10 @@ send_payment_core(struct lightningd *ld,
 		payment->bolt11 = tal_strdup(payment, b11str);
 	else
 		payment->bolt11 = NULL;
+	if (local_offer_id)
+		payment->local_offer_id = tal_dup(payment, struct sha256, local_offer_id);
+	else
+		payment->local_offer_id = NULL;
 
 	/* We write this into db when HTLC is actually sent. */
 	wallet_payment_setup(ld->wallet, payment);
@@ -1034,6 +1104,7 @@ send_payment(struct lightningd *ld,
 	     struct amount_msat total_msat,
 	     const char *label TAKES,
 	     const char *b11str TAKES,
+	     const struct sha256 *local_offer_id,
 	     const struct secret *payment_secret)
 {
 	unsigned int base_expiry;
@@ -1117,7 +1188,7 @@ send_payment(struct lightningd *ld,
 	return send_payment_core(ld, cmd, rhash, partid, &route[0],
 				 msat, total_msat, label, b11str,
 				 packet, &ids[n_hops - 1], ids,
-				 channels, path_secrets);
+				 channels, path_secrets, local_offer_id);
 }
 
 static struct command_result *
@@ -1202,6 +1273,7 @@ static struct command_result *json_sendonion(struct command *cmd,
 	struct secret *path_secrets;
 	struct amount_msat *msat;
 	u64 *partid;
+	struct sha256 *local_offer_id = NULL;
 
 	if (!param(cmd, buffer, params,
 		   p_req("onion", param_bin_from_hex, &onion),
@@ -1213,6 +1285,9 @@ static struct command_result *json_sendonion(struct command *cmd,
 		   p_opt("bolt11", param_string, &b11str),
 		   p_opt_def("msatoshi", param_msat, &msat, AMOUNT_MSAT(0)),
 		   p_opt("destination", param_node_id, &destination),
+#if EXPERIMENTAL_FEATURES
+		   p_opt("local_offer_id", param_sha256, &local_offer_id),
+#endif
 		   NULL))
 		return command_param_failed();
 
@@ -1227,7 +1302,7 @@ static struct command_result *json_sendonion(struct command *cmd,
 	return send_payment_core(ld, cmd, payment_hash, *partid,
 				 first_hop, *msat, AMOUNT_MSAT(0),
 				 label, b11str, packet, destination, NULL, NULL,
-				 path_secrets);
+				 path_secrets, local_offer_id);
 }
 
 static const struct json_command sendonion_command = {
@@ -1353,6 +1428,7 @@ static struct command_result *json_sendpay(struct command *cmd,
 	const char *b11str, *label;
 	u64 *partid;
 	struct secret *payment_secret;
+	struct sha256 *local_offer_id = NULL;
 
 	/* For generating help, give new-style. */
 	if (!param(cmd, buffer, params,
@@ -1363,6 +1439,9 @@ static struct command_result *json_sendpay(struct command *cmd,
 		   p_opt("bolt11", param_string, &b11str),
 		   p_opt("payment_secret", param_secret, &payment_secret),
 		   p_opt_def("partid", param_u64, &partid, 0),
+#if EXPERIMENTAL_FEATURES
+		   p_opt("local_offer_id", param_sha256, &local_offer_id),
+#endif
 		   NULL))
 		return command_param_failed();
 
@@ -1406,7 +1485,7 @@ static struct command_result *json_sendpay(struct command *cmd,
 			    route,
 			    final_amount,
 			    msat ? *msat : final_amount,
-			    label, b11str, payment_secret);
+			    label, b11str, local_offer_id, payment_secret);
 }
 
 static const struct json_command sendpay_command = {

wallet/db.c

@@ -666,6 +666,8 @@ static struct migration dbmigrations[] = {
 	 ");"), NULL},
     /* A reference into our own offers table, if it was made from one */
     {SQL("ALTER TABLE invoices ADD COLUMN local_offer_id BLOB DEFAULT NULL;"), NULL},
+    /* A reference into our own offers table, if it was made from one */
+    {SQL("ALTER TABLE payments ADD COLUMN local_offer_id BLOB DEFAULT NULL;"), NULL},
 };
 
 /* Leak tracking. */

wallet/wallet.c

@@ -2494,8 +2494,9 @@ void wallet_payment_store(struct wallet *wallet,
 		    "  description,"
 		    "  bolt11,"
 		    "  total_msat,"
-		    "  partid"
-		    ") VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);"));
+		    "  partid,"
+		    "  local_offer_id"
+		    ") VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);"));
 
 	db_bind_int(stmt, 0, payment->status);
 	db_bind_sha256(stmt, 1, &payment->payment_hash);
@@ -2537,6 +2538,11 @@ void wallet_payment_store(struct wallet *wallet,
 	db_bind_amount_msat(stmt, 11, &payment->total_msat);
 	db_bind_u64(stmt, 12, payment->partid);
 
+	if (payment->local_offer_id != NULL)
+		db_bind_sha256(stmt, 13, payment->local_offer_id);
+	else
+		db_bind_null(stmt, 13);
+
 	db_exec_prepared_v2(stmt);
 	payment->id = db_last_insert_id_v2(stmt);
 	assert(payment->id > 0);
@@ -2657,6 +2663,12 @@ static struct wallet_payment *wallet_stmt2payment(const tal_t *ctx,
 	else
 		payment->partid = 0;
 
+	if (!db_column_is_null(stmt, 16)) {
+		payment->local_offer_id = tal(payment, struct sha256);
+		db_column_sha256(stmt, 16, payment->local_offer_id);
+	} else
+		payment->local_offer_id = NULL;
+
 	return payment;
 }
 
@@ -2690,6 +2702,7 @@ wallet_payment_by_hash(const tal_t *ctx, struct wallet *wallet,
 					     ", failonionreply"
 					     ", total_msat"
 					     ", partid"
+					     ", local_offer_id"
 					     " FROM payments"
 					     " WHERE payment_hash = ?"
 					     " AND partid = ?"));
@@ -2917,6 +2930,7 @@ wallet_payment_list(const tal_t *ctx,
 						  ", failonionreply"
 						  ", total_msat"
 						  ", partid"
+						  ", local_offer_id"
 						  " FROM payments"
 						  " WHERE payment_hash = ?;"));
 		db_bind_sha256(stmt, 0, payment_hash);
@@ -2938,6 +2952,7 @@ wallet_payment_list(const tal_t *ctx,
 						     ", failonionreply"
 						     ", total_msat"
 						     ", partid"
+						     ", local_offer_id"
 						     " FROM payments"
 						     " ORDER BY id;"));
 	}
@@ -2960,6 +2975,57 @@ wallet_payment_list(const tal_t *ctx,
 	return payments;
 }
 
+const struct wallet_payment **
+wallet_payments_by_offer(const tal_t *ctx,
+			 struct wallet *wallet,
+			 const struct sha256 *local_offer_id)
+{
+	const struct wallet_payment **payments;
+	struct db_stmt *stmt;
+	struct wallet_payment *p;
+	size_t i;
+
+	payments = tal_arr(ctx, const struct wallet_payment *, 0);
+	stmt = db_prepare_v2(wallet->db, SQL("SELECT"
+					     "  id"
+					     ", status"
+					     ", destination"
+					     ", msatoshi"
+					     ", payment_hash"
+					     ", timestamp"
+					     ", payment_preimage"
+					     ", path_secrets"
+					     ", route_nodes"
+					     ", route_channels"
+					     ", msatoshi_sent"
+					     ", description"
+					     ", bolt11"
+					     ", failonionreply"
+					     ", total_msat"
+					     ", partid"
+					     ", local_offer_id"
+					     " FROM payments"
+					     " WHERE local_offer_id = ?;"));
+	db_bind_sha256(stmt, 0, local_offer_id);
+	db_query_prepared(stmt);
+
+	for (i = 0; db_step(stmt); i++) {
+		tal_resize(&payments, i+1);
+		payments[i] = wallet_stmt2payment(payments, stmt);
+	}
+	tal_free(stmt);
+
+	/* Now attach payments not yet in db. */
+	list_for_each(&wallet->unstored_payments, p, list) {
+		if (!p->local_offer_id || !sha256_eq(p->local_offer_id, local_offer_id))
+			continue;
+		tal_resize(&payments, i+1);
+		payments[i++] = p;
+	}
+
+	return payments;
+}
+
 void wallet_htlc_sigs_save(struct wallet *w, u64 channel_id,
 			   const struct bitcoin_signature *htlc_sigs)
 {
@@ -4083,8 +4149,8 @@ static void offer_status_update(struct db *db,
 	stmt = db_prepare_v2(db, SQL("UPDATE invoices"
 				     " SET state=?"
 				     " WHERE state=? AND local_offer_id = ?;"));
-	db_bind_int(stmt, 0, invoice_status_in_db(UNPAID));
-	db_bind_int(stmt, 1, invoice_status_in_db(EXPIRED));
+	db_bind_int(stmt, 0, invoice_status_in_db(EXPIRED));
+	db_bind_int(stmt, 1, invoice_status_in_db(UNPAID));
 	db_bind_sha256(stmt, 2, offer_id);
 	db_exec_prepared_v2(take(stmt));
 }

wallet/wallet.h

@@ -244,6 +244,9 @@ struct wallet_payment {
 
 	/* If we could not decode the fail onion, just add it here. */
 	const u8 *failonion;
+
+	/* If we are associated with an internal offer */
+	struct sha256 *local_offer_id;
 };
 
 struct outpoint {
@@ -1078,6 +1081,13 @@ const struct wallet_payment **wallet_payment_list(const tal_t *ctx,
 						  struct wallet *wallet,
 						  const struct sha256 *payment_hash);
 
+/**
+ * wallet_payments_by_offer - Retrieve a list of payments for this local_offer_id
+ */
+const struct wallet_payment **wallet_payments_by_offer(const tal_t *ctx,
+						       struct wallet *wallet,
+						       const struct sha256 *local_offer_id);
+
 /**
  * wallet_htlc_sigs_save - Store the latest HTLC sigs for the channel
  */