Plugins: Add a notification for invoice payment

Similarly to the 'invoice_payment' hook

lightningd/invoice.c

@@ -1,7 +1,4 @@
 #include "invoice.h"
-#include "json.h"
-#include "jsonrpc.h"
-#include "lightningd.h"
 #include <bitcoin/address.h>
 #include <bitcoin/base58.h>
 #include <bitcoin/script.h>
@@ -25,7 +22,11 @@
 #include <inttypes.h>
 #include <lightningd/channel.h>
 #include <lightningd/hsm_control.h>
+#include <lightningd/json.h>
+#include <lightningd/jsonrpc.h>
+#include <lightningd/lightningd.h>
 #include <lightningd/log.h>
+#include <lightningd/notification.h>
 #include <lightningd/options.h>
 #include <lightningd/peer_control.h>
 #include <lightningd/peer_htlcs.h>
@@ -173,6 +174,10 @@ invoice_payment_hook_cb(struct invoice_payment_hook_payload *payload,
 	struct invoice invoice;
 	enum onion_type failcode;
 
+	/* We notify here to benefit from the payload and because the hook callback is
+	 * called even if the hook is not registered. */
+	notify_invoice_payment(ld, payload->msat, payload->preimage, payload->label);
+
 	tal_del_destructor2(payload->hin, invoice_payload_remove_hin, payload);
 	/* We want to free this, whatever happens. */
 	tal_steal(tmpctx, payload);

lightningd/notification.c

@@ -1,11 +1,12 @@
-#include "lightningd/notification.h"
 #include <ccan/array_size/array_size.h>
 #include <lightningd/json.h>
+#include <lightningd/notification.h>
 
 const char *notification_topics[] = {
 	"connect",
 	"disconnect",
-	"warning"
+	"warning",
+	"invoice_payment"
 };
 
 bool notifications_have_topic(const char *topic)
@@ -59,4 +60,19 @@ void notify_warning(struct lightningd *ld, struct log_entry *l)
 	json_object_end(n->stream); /* .warning */
 	jsonrpc_notification_end(n);
 	plugins_notify(ld->plugins, take(n));
-}
+}
+
+void notify_invoice_payment(struct lightningd *ld, struct amount_msat amount,
+			    struct preimage preimage, const struct json_escape *label)
+{
+	struct jsonrpc_notification *n =
+		jsonrpc_notification_start(NULL, notification_topics[3]);
+	json_object_start(n->stream, notification_topics[3]);
+	json_add_string(n->stream, "msat",
+			type_to_string(tmpctx, struct amount_msat, &amount));
+	json_add_hex(n->stream, "preimage", &preimage, sizeof(preimage));
+	json_add_escaped_string(n->stream, "label", label);
+	json_object_end(n->stream);
+	jsonrpc_notification_end(n);
+	plugins_notify(ld->plugins, take(n));
+}

lightningd/notification.h

@@ -1,6 +1,8 @@
 #ifndef LIGHTNING_LIGHTNINGD_NOTIFICATION_H
 #define LIGHTNING_LIGHTNINGD_NOTIFICATION_H
 #include "config.h"
+#include <ccan/json_escape/json_escape.h>
+#include <common/amount.h>
 #include <lightningd/jsonrpc.h>
 #include <lightningd/lightningd.h>
 #include <lightningd/log.h>
@@ -14,4 +16,7 @@ void notify_disconnect(struct lightningd *ld, struct node_id *nodeid);
 
 void notify_warning(struct lightningd *ld, struct log_entry *l);
 
+void notify_invoice_payment(struct lightningd *ld, struct amount_msat amount,
+			    struct preimage preimage, const struct json_escape *label);
+
 #endif /* LIGHTNING_LIGHTNINGD_NOTIFICATION_H */

lightningd/test/run-invoice-select-inchan.c

@@ -287,6 +287,10 @@ void notify_connect(struct lightningd *ld UNNEEDED, struct node_id *nodeid UNNEE
 /* Generated stub for notify_disconnect */
 void notify_disconnect(struct lightningd *ld UNNEEDED, struct node_id *nodeid UNNEEDED)
 { fprintf(stderr, "notify_disconnect called!\n"); abort(); }
+/* Generated stub for notify_invoice_payment */
+void notify_invoice_payment(struct lightningd *ld UNNEEDED, struct amount_msat amount UNNEEDED,
+			    struct preimage preimage UNNEEDED, const struct json_escape *label UNNEEDED)
+{ fprintf(stderr, "notify_invoice_payment called!\n"); abort(); }
 /* Generated stub for onchaind_funding_spent */
 enum watch_result onchaind_funding_spent(struct channel *channel UNNEEDED,
 					 const struct bitcoin_tx *tx UNNEEDED,