splice: Script for complex splices

New compiler for splice scripts that parses splice scripts, validates them, converts them to json and back again.

Changelog-Added: Splice script parser — takes a custom splice query language to bundle multiple complex splices into a single task in a simple way.

common/Makefile

@@ -92,6 +92,7 @@ COMMON_SRC_NOGEN :=				\
 	common/setup.c				\
 	common/shutdown_scriptpubkey.c		\
 	common/sphinx.c				\
+	common/splice_script.c			\
 	common/status.c				\
 	common/status_levels.c			\
 	common/status_wire.c			\

common/splice_script.h

@@ -0,0 +1,114 @@
+#ifndef LIGHTNING_COMMON_SPLICE_SCRIPT_H
+#define LIGHTNING_COMMON_SPLICE_SCRIPT_H
+
+#include "config.h"
+#include <ccan/tal/tal.h>
+#include <common/channel_id.h>
+#include <common/json_stream.h>
+#include <common/node_id.h>
+
+enum splice_script_error_type {
+	INTERNAL_ERROR,
+	INVALID_TOKEN,
+	DEBUG_DUMP,
+	TOO_MANY_PIPES,
+	TOO_MANY_ATS,
+	TOO_MANY_COLONS,
+	TOO_MANY_PLUS,
+	TOO_MANY_MINUS,
+	INVALID_NODEID,
+	INVALID_CHANID,
+	WRONG_NUM_SEGMENT_CHUNKS,
+	MISSING_ARROW,
+	NO_MATCHING_NODES,
+	INVALID_INDEX,
+	CHAN_INDEX_ON_WILDCARD_NODE,
+	CHAN_INDEX_NOT_FOUND,
+	CHANQUERY_TYPEERROR,
+	NODE_ID_MULTIMATCH,
+	NODE_ID_CHAN_OVERMATCH,
+	CHAN_ID_MULTIMATCH,
+	CHAN_ID_NODE_OVERMATCH,
+	NODE_ID_NO_UNUSED,
+	DOUBLE_MIDDLE_OP,
+	MISSING_MIDDLE_OP,
+	MISSING_AMOUNT_OP,
+	MISSING_AMOUNT_OR_WILD_OP,
+	CANNOT_PARSE_SAT_AMNT,
+	ZERO_AMOUNTS,
+	IN_AND_OUT_AMOUNTS,
+	MISSING_PERCENT,
+	LEASE_AMOUNT_ZERO,
+	CHANNEL_ID_UNRECOGNIZED,
+	DUPLICATE_CHANID,
+	INVALID_MIDDLE_OP,
+	INSUFFICENT_FUNDS,
+	PERCENT_IS_ZERO,
+	WILDCARD_IS_ZERO,
+	INVALID_PERCENT,
+	LEFT_PERCENT_OVER_100,
+	LEFT_FEE_NOT_NEGATIVE,
+	RIGHT_FEE_NOT_POSITIVE,
+	MISSING_FEESTR,
+	DUPLICATE_FEESTR,
+	TOO_MUCH_DECIMAL,
+	INVALID_FEERATE,
+};
+
+struct splice_script_error {
+	enum splice_script_error_type type;
+	size_t script_index; /* where in `script` was error found */
+	char *message;
+	const char *phase;
+};
+
+/* Outputs a multiline helpful compiler error for the user. */
+char *fmt_splice_script_compiler_error(const tal_t *ctx,
+				       const char *script,
+				       struct splice_script_error *error);
+
+struct splice_script_chan {
+	struct node_id node_id;
+	struct channel_id chan_id;
+};
+
+struct splice_script_result {
+	/* Lease request info */
+	struct amount_sat lease_sat;
+	u32 lease_max_ppm;
+
+	/* Funds going in to destination (just one) */
+	struct amount_sat in_sat;
+	u32 in_ppm;
+
+	/* Destination (just one) */
+	struct channel_id *channel_id;
+	char *bitcoin_address;
+	bool onchain_wallet;
+
+	/* Funds coming out of destination (just one) */
+	struct amount_sat out_sat;
+	u32 out_ppm; /* UINT32_MAX means "max available from channel" */
+
+	/* If true, this 'destination' pays the fee. Only one destination may
+	 * do so. If feerate_per_kw is non-zero, it will be used for feerate. */
+	bool pays_fee;
+	u32 feerate_per_kw;
+};
+
+struct splice_script_error *parse_splice_script(const tal_t *ctx,
+						const char *script,
+						struct splice_script_chan **channels,
+						struct splice_script_result ***result);
+
+void splice_to_json(const tal_t *ctx,
+		    struct splice_script_result **splice,
+		    struct json_stream *js);
+
+bool json_to_splice(const tal_t *ctx, const char *buffer, const jsmntok_t *tok,
+		    struct splice_script_result ***result);
+
+char *splice_to_string(const tal_t *ctx, struct splice_script_result *splice);
+char *splicearr_to_string(const tal_t *ctx, struct splice_script_result **splice);
+
+#endif /* LIGHTNING_COMMON_SPLICE_SCRIPT_H */