plugin: Add a data backend for the new payment state-machine

plugins/Makefile

@@ -13,8 +13,8 @@ PLUGIN_BCLI_OBJS := $(PLUGIN_BCLI_SRC:.c=.o)
 PLUGIN_KEYSEND_SRC := plugins/keysend.c
 PLUGIN_KEYSEND_OBJS := $(PLUGIN_KEYSEND_SRC:.c=.o)
 
-PLUGIN_LIB_SRC := plugins/libplugin.c
-PLUGIN_LIB_HEADER := plugins/libplugin.h
+PLUGIN_LIB_SRC := plugins/libplugin.c plugins/libplugin-pay.c
+PLUGIN_LIB_HEADER := plugins/libplugin.h plugins/libplugin-pay.h
 PLUGIN_LIB_OBJS := $(PLUGIN_LIB_SRC:.c=.o)
 
 PLUGIN_COMMON_OBJS :=				\

plugins/libplugin-pay.h

@@ -0,0 +1,68 @@
+#ifndef LIGHTNING_PLUGINS_LIBPLUGIN_PAY_H
+#define LIGHTNING_PLUGINS_LIBPLUGIN_PAY_H
+#include "config.h"
+
+#include <plugins/libplugin.h>
+
+enum route_hop_style {
+	ROUTE_HOP_LEGACY = 1,
+	ROUTE_HOP_TLV = 2,
+};
+
+struct route_hop {
+	struct short_channel_id channel_id;
+	int direction;
+	struct node_id nodeid;
+	struct amount_msat amount;
+	u32 delay;
+	struct pubkey *blinding;
+	enum route_hop_style style;
+};
+
+/* A parsed version of the possible outcomes that a sendpay / payment may
+ * result in. */
+struct payment_result {
+};
+
+/* Relevant information about a local channel so we can  exclude them early. */
+struct channel_status {
+};
+
+struct payment {
+
+	/* Real destination we want to route to */
+	struct node_id *destination;
+
+	/* Payment hash extracted from the invoice if any. */
+	struct sha256 *payment_hash;
+
+	u32 partid;
+
+	/* Destination we should ask `getroute` for. This might differ from
+	 * the above destination if we use rendez-vous routing of blinded
+	 * paths to amend the route later in a mixin. */
+	struct node_id  *getroute_destination;
+
+	/* Target amount to be delivered at the destination */
+	struct amount_msat amount;
+
+	/* tal_arr of route_hops we decoded from the `getroute` call. Exposed
+	 * here so it can be amended by mixins. */
+	struct route_hop *route;
+
+	struct channel_status *peer_channels;
+
+	/* The blockheight at which the payment attempt was
+	 * started.  */
+	u32 start_block;
+
+	struct timeabs start_time, end_time;
+	struct timeabs deadline;
+
+	struct amount_msat extra_budget;
+
+	struct short_channel_id *exclusions;
+
+};
+
+#endif /* LIGHTNING_PLUGINS_LIBPLUGIN_PAY_H */