lightning/wire/tlvstream.h

#ifndef LIGHTNING_WIRE_TLVSTREAM_H
#define LIGHTNING_WIRE_TLVSTREAM_H
#include "config.h"
#include <bitcoin/short_channel_id.h>
#include <ccan/short_types/short_types.h>
#include <ccan/tal/tal.h>

struct tlv_record_type {
	u64 type;
	/* If this type is present return marshalled value.  Otherwise
	 * returns NULL. */
	u8 *(*towire)(const tal_t *ctx, const void *record);
	/* Must call fromwire_fail() if it can't parse. */
	void (*fromwire)(const u8 **cursor, size_t *max, void *record);
};

/* A single TLV field, consisting of the data and its associated metadata. */
struct tlv_field {
	/* If this is a type that is known to c-lightning we have a pointer to
	 * the metadata. */
	const struct tlv_record_type *meta;

	/* In any case we'll have the numeric type, even if we don't have a
	 * name that we can call it. */
	u64 numtype;
	size_t length;
	u8 *value;
};

/* Given any tlvstream serialize the raw fields (untyped ones). */
void towire_tlvstream_raw(u8 **pptr, const struct tlv_field *fields);

/* Given a tlv record with manually-set fields, populate ->fields */
#define tlv_make_fields(tlv, type)					\
	tlv_make_fields_(tlvs_##type, TLVS_ARRAY_SIZE_##type, (tlv))

struct tlv_field *tlv_make_fields_(const struct tlv_record_type *types,
				   size_t num_types,
				   const void *record);

/* Generic TLV decode/encode */
bool fromwire_tlv(const u8 **cursor, size_t *max,
		  const struct tlv_record_type *types, size_t num_types,
		  void *record, struct tlv_field **fields);
void towire_tlv(u8 **pptr,
		const struct tlv_record_type *types, size_t num_types,
		const void *record);
bool tlv_fields_valid(const struct tlv_field *fields, size_t *err_index);



/* Generic primitive setters for tlvstreams. */
void tlvstream_set_raw(struct tlv_field **stream, u64 type, void *value, size_t valuelen);
void tlvstream_set_short_channel_id(struct tlv_field **stream, u64 type,
				    struct short_channel_id *value);
void tlvstream_set_tu64(struct tlv_field **stream, u64 type, u64 value);
void tlvstream_set_tu32(struct tlv_field **stream, u64 type, u32 value);

/* Generic primitive gettes for tlvstreams. */
bool tlvstream_get_short_channel_id(struct tlv_field *stream, u64 type,
				    struct short_channel_id *value);
bool tlvstream_get_tu64(struct tlv_field *stream, u64 type, u64 *value);
bool tlvstream_get_tu32(struct tlv_field *stream, u64 type, u32 *value);

#endif /* LIGHTNING_WIRE_TLVSTREAM_H */