core-lightning/common/features.h
Christian Decker a07797c166 features: Add function to unset a featurebit
Needed so we can blank optional bits when comparing channel_types.
2022-07-04 22:14:06 +02:00

163 lines
5.4 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>
enum feature_place {
INIT_FEATURE,
GLOBAL_INIT_FEATURE,
NODE_ANNOUNCE_FEATURE,
CHANNEL_FEATURE,
BOLT11_FEATURE,
};
#define NUM_FEATURE_PLACE (BOLT11_FEATURE+1)
extern const char *feature_place_names[NUM_FEATURE_PLACE];
/* The complete set of features for all contexts */
struct feature_set {
u8 *bits[NUM_FEATURE_PLACE];
};
/* Create feature set for a known feature. */
struct feature_set *feature_set_for_feature(const tal_t *ctx, int feature);
/* Marshalling a feature set */
struct feature_set *fromwire_feature_set(const tal_t *ctx,
const u8 **ptr, size_t *max);
void towire_feature_set(u8 **pptr, const struct feature_set *fset);
/* a |= b, or returns false if features already in a */
bool feature_set_or(struct feature_set *a,
const struct feature_set *b TAKES);
/* a - b, or returns false if features not already in a */
bool feature_set_sub(struct feature_set *a,
const struct feature_set *b TAKES);
/* Returns -1 if we're OK with all these offered features, otherwise first
* unsupported (even) feature. */
int features_unsupported(const struct feature_set *our_features,
const u8 *their_features,
enum feature_place p);
/* For the features in channel_announcement */
u8 *get_agreed_channelfeatures(const tal_t *ctx,
const struct feature_set *our_features,
const u8 *theirfeatures);
/* 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 feature_negotiated(const struct feature_set *our_features,
const u8 *their_features, size_t f);
/* Features can depend on other features: both must be set!
* Sets @depender, @missing_dependency if returns false.
*/
bool feature_check_depends(const u8 *their_features,
size_t *depender, size_t *missing_dependency);
/* Return a list of what (init) features we advertize. */
const char **list_supported_features(const tal_t *ctx,
const struct feature_set *fset);
/* Give a name for this feature */
const char *feature_name(const tal_t *ctx, size_t f);
/* 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);
/* Given two featurebit vectors, combine them by applying a logical OR. */
u8 *featurebits_or(const tal_t *ctx, const u8 *f1 TAKES, const u8 *f2 TAKES);
/* Unset a given bit in a featurebits string */
void featurebits_unset(u8 **ptr, size_t bit);
/* Are these two feature bitsets functionally equal (one may have
* trailing zeroes)? */
bool featurebits_eq(const u8 *f1, const u8 *f2);
/* Good for debugging: returns comma-separated string of bits. */
const char *fmt_featurebits(const tal_t *ctx, const u8 *featurebits);
struct feature_set *feature_set_dup(const tal_t *ctx,
const struct feature_set *other);
/* 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:
*
* | Bits | Name |...
* | 0/1 | `option_data_loss_protect` |...
* | 3 | `initial_routing_sync` |...
* | 4/5 | `option_upfront_shutdown_script` |...
* | 6/7 | `gossip_queries` |...
* | 8/9 | `var_onion_optin` |...
* | 10/11 | `gossip_queries_ex` |...
* | 12/13 | `option_static_remotekey` |...
*/
#define OPT_DATA_LOSS_PROTECT 0
#define OPT_INITIAL_ROUTING_SYNC 2
#define OPT_UPFRONT_SHUTDOWN_SCRIPT 4
#define OPT_GOSSIP_QUERIES 6
#define OPT_VAR_ONION 8
#define OPT_GOSSIP_QUERIES_EX 10
#define OPT_STATIC_REMOTEKEY 12
/* BOLT #9:
*
* | 14/15 | `payment_secret` |... IN9 ...
* | 16/17 | `basic_mpp` |... IN9 ...
* | 18/19 | `option_support_large_channel` |... IN ...
* | 20/21 | `option_anchor_outputs` |... IN ...
* | 22/23 | `option_anchors_zero_fee_htlc_tx` |... IN ...
* | 26/27 | `option_shutdown_anysegwit` |... IN ...
* | 48/49 | `option_payment_metadata` |... 9 ...
*/
#define OPT_PAYMENT_SECRET 14
#define OPT_BASIC_MPP 16
#define OPT_LARGE_CHANNELS 18
#define OPT_ANCHOR_OUTPUTS 20
#define OPT_ANCHORS_ZERO_FEE_HTLC_TX 22
#define OPT_SHUTDOWN_ANYSEGWIT 26
#define OPT_PAYMENT_METADATA 48
/* BOLT-f53ca2301232db780843e894f55d95d512f297f9 #9:
* | 28/29 | `option_dual_fund` | ... IN9 ...
*/
#define OPT_DUAL_FUND 28
/* BOLT-519be05f61e2c35ddf95b731203f89b4ee0946c3 #9:
* | 46/47 | `option_scid_alias` | ... IN ...
* | 50/51 | `option_eroconf` | ... IN ...
*/
#define OPT_SCID_ALIAS 46
#define OPT_ZEROCONF 50
/* BOLT-quiescent #9:
* | 34/35 | `option_quiesce` | ... IN ...
*/
#define OPT_QUIESCE 34
/* BOLT-offers #9:
*
* | 38/39 | `option_onion_messages` |... IN ...
*/
#define OPT_ONION_MESSAGES 38
#define OPT_SHUTDOWN_WRONG_FUNDING 104
#endif /* LIGHTNING_COMMON_FEATURES_H */