rgb-cln/common/features.h

#ifndef LIGHTNING_COMMON_FEATURES_H
#define LIGHTNING_COMMON_FEATURES_H
#include "config.h"
#include <ccan/short_types/short_types.h>
#include <ccan/tal/tal.h>

/* Returns true if we're OK with all these offered features. */
bool features_supported(const u8 *globalfeatures, const u8 *localfeatures);

/* For sending our features: tal_count() returns length. */
u8 *get_offered_globalfeatures(const tal_t *ctx);
u8 *get_offered_localfeatures(const tal_t *ctx);

/* Is this feature bit requested? (Either compulsory or optional) */
bool feature_offered(const u8 *features, size_t f);

/* Was this feature bit offered by them and us? */
bool local_feature_negotiated(const u8 *lfeatures, size_t f);
bool global_feature_negotiated(const u8 *gfeatures, size_t f);

/* Return a list of what features we advertize. */
const char **list_supported_features(const tal_t *ctx);

/* Low-level helpers to deal with big-endian bitfields. */
bool feature_is_set(const u8 *features, size_t bit);
void set_feature_bit(u8 **ptr, u32 bit);

/* BOLT-531c8d7d9b01ab610b8a73a0deba1b9e9c83e1ed #9:
 *
 * Flags are numbered from the least-significant bit, at bit 0 (i.e. 0x1,
 * an _even_ bit). They are generally assigned in pairs so that features
 * can be introduced as optional (_odd_ bits) and later upgraded to be compulsory
 * (_even_ bits), which will be refused by outdated nodes:
 * see [BOLT #1: The `init` Message](01-messaging.md#the-init-message).
 */
#define COMPULSORY_FEATURE(x)	((x) & 0xFFFFFFFE)
#define OPTIONAL_FEATURE(x)	((x) | 1)

/* BOLT-531c8d7d9b01ab610b8a73a0deba1b9e9c83e1ed #9:
 *
 * ## Assigned `localfeatures` flags
 *...
 * | Bits | Name                             |...
 * | 0/1  | `option_data_loss_protect`       |...
 * | 3    | `initial_routing_sync`           |...
 * | 4/5  | `option_upfront_shutdown_script` |...
 * | 6/7  | `gossip_queries`                 |...
 * | 12/13| `option_static_remotekey`        |...
 */
#define LOCAL_DATA_LOSS_PROTECT			0
#define LOCAL_INITIAL_ROUTING_SYNC		2
#define LOCAL_UPFRONT_SHUTDOWN_SCRIPT		4
#define LOCAL_GOSSIP_QUERIES			6
#define LOCAL_STATIC_REMOTEKEY			12

/* BOLT-927c96daab2338b716708a57cd75c84a2d169e0e #9:
 * | Bits  | Name                            |...
 * | 10/11 | `gossip_queries_ex`             |...
 */
#define LOCAL_GOSSIP_QUERIES_EX			10

/* BOLT #9:
 *
 * ## Assigned `globalfeatures` flags
 *...
 * | Bits | Name              | ...
 * | 8/9  | `var_onion_optin` | ...
 */
#define GLOBAL_VAR_ONION			8

#endif /* LIGHTNING_COMMON_FEATURES_H */