core-lightning/common/features.h
Rusty Russell 2e3eadbe91 common/features: expose feature bitmap low-level functions.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2019-09-05 23:39:05 -05:00

70 lines
2.3 KiB
C

#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 #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* (_even_ bits), which will be refused by outdated nodes: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 #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` |...
*/
#define LOCAL_DATA_LOSS_PROTECT 0
#define LOCAL_INITIAL_ROUTING_SYNC 2
#define LOCAL_UPFRONT_SHUTDOWN_SCRIPT 4
#define LOCAL_GOSSIP_QUERIES 6
/* 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 */