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channel_gossip.c
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#include "config.h"
#include <ccan/cast/cast.h>
#include <ccan/mem/mem.h>
#include <common/memleak.h>
#include <common/timeout.h>
#include <common/wire_error.h>
#include <connectd/connectd_wiregen.h>
#include <hsmd/hsmd_wiregen.h>
#include <lightningd/chaintopology.h>
#include <lightningd/channel.h>
#include <lightningd/channel_gossip.h>
#include <lightningd/gossip_generation.h>
#include <lightningd/hsm_control.h>
#include <lightningd/lightningd.h>
#include <lightningd/peer_control.h>
#include <lightningd/subd.h>
enum channel_gossip_state {
/* Not a public channel */
CGOSSIP_PRIVATE,
/* We can't yet send (non-forwardable) channel_update. */
CGOSSIP_NOT_USABLE,
/* Not yet in at announcable depth. */
CGOSSIP_NOT_DEEP_ENOUGH,
/* We want the peer's announcement_signatures. */
CGOSSIP_NEED_PEER_SIGS,
/* We have received sigs, and announced. */
CGOSSIP_ANNOUNCED,
};
static const char *channel_gossip_state_str(enum channel_gossip_state s)
{
switch (s) {
case CGOSSIP_PRIVATE:
return "CGOSSIP_PRIVATE";
case CGOSSIP_NOT_USABLE:
return "CGOSSIP_NOT_USABLE";
case CGOSSIP_NOT_DEEP_ENOUGH:
return "CGOSSIP_NOT_DEEP_ENOUGH";
case CGOSSIP_NEED_PEER_SIGS:
return "CGOSSIP_NEED_PEER_SIGS";
case CGOSSIP_ANNOUNCED:
return "CGOSSIP_ANNOUNCED";
}
return "***INVALID***";
}
struct remote_announce_sigs {
struct short_channel_id scid;
secp256k1_ecdsa_signature node_sig;
secp256k1_ecdsa_signature bitcoin_sig;
};
struct channel_gossip {
enum channel_gossip_state state;
/* Cached update info */
const u8 *cupdate;
/* Remote channel_announcement sigs we've received (but not
* necessarily committed!) */
struct remote_announce_sigs *remote_sigs;
/* Timer to refresh public channels every 13 days */
struct oneshot *refresh_timer;
/* Details of latest channel_update sent by peer */
const struct peer_update *peer_update;
};
static bool starting_up = true, gossipd_init_done = false;
/* We send non-forwardable channel updates if we can. */
static bool can_send_channel_update(const struct channel *channel)
{
/* Can't send if we can't talk about it. */
if (!channel->scid && !channel->alias[REMOTE])
return false;
if (channel_state_pre_open(channel->state))
return false;
return true;
}
/* We send start the channel announcement signatures if we can.
* Caller must check it's not CGOSSIP_PRIVATE, but this is used
* to set up state so we cannot assert here!
*/
static bool channel_announceable(const struct channel *channel,
u32 block_height)
{
if (!channel->scid)
return false;
return is_scid_depth_announceable(*channel->scid, block_height);
}
static void check_channel_gossip(const struct channel *channel)
{
struct channel_gossip *cg = channel->channel_gossip;
/* Note: we can't assert is_scid_depth_announceable, for two reasons:
* 1. on restart and rescan, block numbers can go backwards.'
* 2. We don't get notified via channel_gossip_notify_new_block until
* there are no new blocks to add, not on every block.
*/
switch (cg->state) {
case CGOSSIP_PRIVATE:
assert(!(channel->channel_flags & CHANNEL_FLAGS_ANNOUNCE_CHANNEL));
assert(!cg->remote_sigs);
assert(!cg->refresh_timer);
return;
case CGOSSIP_NOT_USABLE:
assert(channel->channel_flags & CHANNEL_FLAGS_ANNOUNCE_CHANNEL);
assert(!can_send_channel_update(channel));
assert(!cg->refresh_timer);
return;
case CGOSSIP_NOT_DEEP_ENOUGH:
assert(channel->channel_flags & CHANNEL_FLAGS_ANNOUNCE_CHANNEL);
assert(can_send_channel_update(channel));
assert(!cg->refresh_timer);
return;
case CGOSSIP_NEED_PEER_SIGS:
assert(can_send_channel_update(channel));
assert(channel->scid);
/* If we have sigs, they don't match */
if (cg->remote_sigs)
assert(!channel->scid || !short_channel_id_eq(cg->remote_sigs->scid, *channel->scid));
assert(!cg->refresh_timer);
return;
case CGOSSIP_ANNOUNCED:
assert(can_send_channel_update(channel));
assert(channel->scid);
assert(cg->remote_sigs);
return;
}
fatal("Bad channel_gossip_state %u", cg->state);
}
static void msg_to_peer(const struct peer *peer, const u8 *msg TAKES)
{
struct lightningd *ld = peer->ld;
/* Shutting down, or peer not connected? */
if (ld->connectd && peer->connected == PEER_CONNECTED) {
subd_send_msg(ld->connectd,
take(towire_connectd_peer_send_msg(NULL,
&peer->id,
peer->connectd_counter,
msg)));
}
if (taken(msg))
tal_free(msg);
}
static void addgossip_reply(struct subd *gossipd,
const u8 *reply,
const int *fds UNUSED,
char *desc)
{
char *err;
if (!fromwire_gossipd_addgossip_reply(reply, reply, &err))
fatal("Reading gossipd_addgossip_reply for %s: %s",
desc, tal_hex(tmpctx, reply));
if (strlen(err))
log_broken(gossipd->log, "gossipd rejected our %s: %s", desc, err);
}
static void broadcast_new_gossip(struct lightningd *ld,
const u8 *msg TAKES,
struct amount_sat *known_channel,
const char *desc)
{
struct peer *peer;
struct peer_node_id_map_iter it;
if (taken(msg))
tal_steal(tmpctx, msg);
/* Tell gossipd about it */
subd_req(ld->gossip, ld->gossip,
take(towire_gossipd_addgossip(NULL, msg, known_channel)),
-1, 0, addgossip_reply, cast_const(char *, desc));
/* Don't tell them if we're supposed to be suppressing gossip for tests */
if (ld->dev_suppress_gossip)
return;
/* Tell all our peers about it, too! */
for (peer = peer_node_id_map_first(ld->peers, &it);
peer;
peer = peer_node_id_map_next(ld->peers, &it)) {
msg_to_peer(peer, msg);
}
}
/* Recursion */
static void cupdate_timer_refresh(struct channel *channel);
static void set_public_cupdate(struct channel *channel,
const u8 *cupdate TAKES,
bool refresh_later)
{
struct lightningd *ld = channel->peer->ld;
struct channel_gossip *cg = channel->channel_gossip;
u32 timestamp;
bool enabled;
struct timeabs now, due;
if (!channel_update_details(cupdate, ×tamp, &enabled)) {
log_broken(channel->log, "Invalid channel_update %s: ignoring",
tal_hex(tmpctx, cupdate));
if (taken(cupdate))
tal_free(cupdate);
return;
}
tal_free(cg->cupdate);
cg->cupdate = tal_dup_talarr(cg, u8, cupdate);
cg->refresh_timer = tal_free(cg->refresh_timer);
/* If enabled, we refresh, based on old timestamp */
if (!enabled || !refresh_later)
return;
due.ts.tv_sec = timestamp;
due.ts.tv_nsec = 0;
due = timeabs_add(due,
time_from_sec(GOSSIP_PRUNE_INTERVAL(ld->dev_fast_gossip_prune)
- GOSSIP_BEFORE_DEADLINE(ld->dev_fast_gossip_prune)));
/* In case it's passed, timer should be zero */
now = time_now();
if (time_after(now, due))
due = now;
cg->refresh_timer = new_reltimer(ld->timers, cg,
time_between(due, now),
cupdate_timer_refresh,
channel);
}
static enum channel_gossip_state init_public_state(struct channel *channel,
const struct remote_announce_sigs *remote_sigs)
{
struct lightningd *ld = channel->peer->ld;
if (!can_send_channel_update(channel))
return CGOSSIP_NOT_USABLE;
/* Note: depth when we startup is not actually reliable, since
* we step one block back. We'll fix this up when gossipd
* tells us it's announced, or, when we add the block. */
if (!channel_announceable(channel, get_block_height(ld->topology)))
return CGOSSIP_NOT_DEEP_ENOUGH;
if (!remote_sigs) {
return CGOSSIP_NEED_PEER_SIGS;
}
return CGOSSIP_ANNOUNCED;
}
static u8 *sign_update(const tal_t *ctx,
struct lightningd *ld,
const u8 *unsigned_cupdate)
{
const u8 *msg;
u8 *signed_update;
/* Sign it please! */
msg = hsm_sync_req(tmpctx, ld,
take(towire_hsmd_cupdate_sig_req(NULL, unsigned_cupdate)));
if (!fromwire_hsmd_cupdate_sig_reply(ctx, msg, &signed_update))
fatal("Reading cupdate_sig_reply: %s", tal_hex(tmpctx, msg));
return signed_update;
}
/* Try to send a channel_update direct to peer, unless redundant */
static void send_private_cupdate(struct channel *channel, bool even_if_redundant)
{
struct channel_gossip *cg = channel->channel_gossip;
const u8 *cupdate;
struct short_channel_id scid;
/* Only useful channels: not if closing */
if (!channel_state_can_add_htlc(channel->state))
return;
/* BOLT #7:
*
* - MAY create a `channel_update` to communicate the channel
* parameters to the channel peer, even though the channel has not
* yet been announced (i.e. the `announce_channel` bit was not set).
* - MUST set the `short_channel_id` to either an `alias` it has
* received from the peer, or the real channel `short_channel_id`.
* - MUST set `dont_forward` to 1 in `message_flags`
*/
/* We prefer their alias, if possible: they might not have seen the block which
* mined the funding tx yet, so the scid would be meaningless to them. */
if (channel->alias[REMOTE])
scid = *channel->alias[REMOTE];
else
scid = *channel->scid;
/* We always set "enabled" on unannounced channels, since if peer
* receives it, that's what it means */
cupdate = unsigned_channel_update(tmpctx, channel, scid,
NULL, false, true);
/* Suppress redundant ones (except on reconnect, in case it's
* lost) */
if (cg->cupdate) {
if (!even_if_redundant
&& channel_update_same(cg->cupdate, cupdate)) {
return;
}
tal_free(cg->cupdate);
}
cg->cupdate = sign_update(cg, channel->peer->ld, cupdate);
msg_to_peer(channel->peer, cg->cupdate);
}
/* Send gossipd a channel_update, if not redundant. */
static void broadcast_public_cupdate(struct channel *channel,
bool ok_if_disconnected)
{
struct lightningd *ld = channel->peer->ld;
struct channel_gossip *cg = channel->channel_gossip;
const u8 *cupdate;
u32 old_timestamp;
bool enable, have_old;
/* If we have no previous channel_update, this fails */
have_old = channel_update_details(cg->cupdate,
&old_timestamp, &enable);
if (!channel_state_can_add_htlc(channel->state)) {
/* If it's (no longer) usable, it's a simply courtesy
* to disable */
enable = false;
} else if (channel->owner) {
/* If it's live, it's enabled */
enable = true;
} else if (starting_up) {
/* If we are starting up, don't change it! */
if (!have_old)
/* Assume the best if we don't have an updated */
enable = true;
} else {
enable = ok_if_disconnected;
}
cupdate = unsigned_channel_update(tmpctx, channel, *channel->scid,
have_old ? &old_timestamp : NULL,
true,
enable);
/* Suppress redundant ones */
if (cg->cupdate && channel_update_same(cg->cupdate, cupdate))
return;
set_public_cupdate(channel,
take(sign_update(NULL, channel->peer->ld, cupdate)),
true);
broadcast_new_gossip(ld, cg->cupdate, NULL, "channel update");
}
static void cupdate_timer_refresh(struct channel *channel)
{
struct channel_gossip *cg = channel->channel_gossip;
/* Don't try to free this again if set_public_cupdate called later */
cg->refresh_timer = NULL;
log_debug(channel->log, "Sending keepalive channel_update for %s",
fmt_short_channel_id(tmpctx, *channel->scid));
/* Free old cupdate to force a new one to be generated */
cg->cupdate = tal_free(cg->cupdate);
broadcast_public_cupdate(channel, true);
}
static void stash_remote_announce_sigs(struct channel *channel,
struct short_channel_id scid,
const secp256k1_ecdsa_signature *node_sig,
const secp256k1_ecdsa_signature *bitcoin_sig)
{
struct channel_gossip *cg = channel->channel_gossip;
const char *err;
/* BOLT #7:
* - if the `node_signature` OR the `bitcoin_signature` is NOT correct:
* - MAY send a `warning` and close the connection, or send an
* `error` and fail the channel.
*/
err = check_announce_sigs(channel, scid, node_sig, bitcoin_sig);
if (err) {
channel_fail_transient(channel, true,
"Bad gossip announcement_signatures for scid %s: %s",
fmt_short_channel_id(tmpctx, scid),
err);
return;
}
tal_free(cg->remote_sigs);
cg->remote_sigs = tal(cg, struct remote_announce_sigs);
cg->remote_sigs->scid = scid;
cg->remote_sigs->node_sig = *node_sig;
cg->remote_sigs->bitcoin_sig = *bitcoin_sig;
log_debug(channel->log,
"channel_gossip: received announcement sigs for %s (we have %s)",
fmt_short_channel_id(tmpctx, scid),
channel->scid ? fmt_short_channel_id(tmpctx, *channel->scid) : "none");
}
static bool apply_remote_sigs(struct channel *channel)
{
struct channel_gossip *cg = channel->channel_gossip;
if (!cg->remote_sigs)
return false;
if (!short_channel_id_eq(cg->remote_sigs->scid, *channel->scid)) {
log_debug(channel->log, "We have remote sigs, but wrong scid!");
return false;
}
wallet_announcement_save(channel->peer->ld->wallet,
channel->dbid,
&cg->remote_sigs->node_sig,
&cg->remote_sigs->bitcoin_sig);
return true;
}
static void send_channel_announce_sigs(struct channel *channel)
{
/* First 2 + 256 byte are the signatures and msg type, skip them */
const size_t offset = 258;
struct lightningd *ld = channel->peer->ld;
struct sha256_double hash;
secp256k1_ecdsa_signature local_node_sig, local_bitcoin_sig;
const u8 *ca, *msg;
/* If it's already closing, don't bother. */
if (!channel_state_can_add_htlc(channel->state))
return;
/* Wait until we've exchanged reestablish messages */
if (!channel->reestablished) {
log_debug(channel->log, "channel_gossip: not sending channel_announcement_sigs until reestablished");
return;
}
ca = create_channel_announcement(tmpctx, channel, *channel->scid,
NULL, NULL, NULL, NULL);
msg = hsm_sync_req(tmpctx, ld,
take(towire_hsmd_sign_any_cannouncement_req(NULL,
ca,
&channel->peer->id,
channel->dbid)));
if (!fromwire_hsmd_sign_any_cannouncement_reply(msg, &local_node_sig, &local_bitcoin_sig))
fatal("Reading hsmd_sign_any_cannouncement_reply: %s", tal_hex(tmpctx, msg));
/* Double-check that HSM gave valid signatures. */
sha256_double(&hash, ca + offset, tal_count(ca) - offset);
if (!check_signed_hash(&hash, &local_node_sig, &ld->our_pubkey)) {
channel_internal_error(channel,
"HSM returned an invalid node signature");
return;
}
if (!check_signed_hash(&hash, &local_bitcoin_sig, &channel->local_funding_pubkey)) {
channel_internal_error(channel,
"HSM returned an invalid bitcoin signature");
return;
}
msg = towire_announcement_signatures(NULL,
&channel->cid, *channel->scid,
&local_node_sig, &local_bitcoin_sig);
msg_to_peer(channel->peer, take(msg));
}
static void send_channel_announcement(struct channel *channel)
{
secp256k1_ecdsa_signature local_node_sig, local_bitcoin_sig;
struct lightningd *ld = channel->peer->ld;
const u8 *ca, *msg;
struct channel_gossip *cg = channel->channel_gossip;
ca = create_channel_announcement(tmpctx, channel, *channel->scid,
NULL, NULL,
&cg->remote_sigs->node_sig,
&cg->remote_sigs->bitcoin_sig);
msg = hsm_sync_req(tmpctx, ld,
take(towire_hsmd_sign_any_cannouncement_req(NULL, ca,
&channel->peer->id,
channel->dbid)));
if (!fromwire_hsmd_sign_any_cannouncement_reply(msg,
&local_node_sig,
&local_bitcoin_sig))
fatal("Reading hsmd_sign_any_cannouncement_reply: %s", tal_hex(tmpctx, msg));
/* Don't crash if shutting down */
if (!ld->gossip)
return;
ca = create_channel_announcement(tmpctx, channel, *channel->scid,
&local_node_sig,
&local_bitcoin_sig,
&cg->remote_sigs->node_sig,
&cg->remote_sigs->bitcoin_sig);
/* Send everyone our new channel announcement */
broadcast_new_gossip(ld, ca, &channel->funding_sats, "channel announcement");
/* We can also send our first public channel_update now */
broadcast_public_cupdate(channel, true);
/* And maybe our first node_announcement */
channel_gossip_node_announce(ld);
}
static void set_gossip_state(struct channel *channel,
enum channel_gossip_state state)
{
struct channel_gossip *cg = channel->channel_gossip;
cg->state = state;
switch (cg->state) {
case CGOSSIP_PRIVATE:
abort();
case CGOSSIP_NOT_USABLE:
return;
case CGOSSIP_NOT_DEEP_ENOUGH:
/* But it exists, so try sending private channel_update */
send_private_cupdate(channel, false);
return;
case CGOSSIP_NEED_PEER_SIGS:
send_channel_announce_sigs(channel);
/* We may already have remote signatures */
if (!apply_remote_sigs(channel))
return;
cg->state = CGOSSIP_ANNOUNCED;
/* fall thru */
case CGOSSIP_ANNOUNCED:
/* Any previous update was private, so clear. */
cg->cupdate = tal_free(cg->cupdate);
send_channel_announcement(channel);
return;
}
fatal("Bad channel_gossip_state %u", cg->state);
}
/* Initialize channel->channel_gossip state */
void channel_gossip_init(struct channel *channel,
const struct peer_update *remote_update)
{
struct lightningd *ld = channel->peer->ld;
struct channel_gossip *cg;
bool public = (channel->channel_flags & CHANNEL_FLAGS_ANNOUNCE_CHANNEL);
cg = channel->channel_gossip = tal(channel, struct channel_gossip);
cg->cupdate = NULL;
cg->refresh_timer = NULL;
cg->peer_update = tal_dup_or_null(channel, struct peer_update, remote_update);
cg->remote_sigs = NULL;
/* If we have an scid, we might have announcement signatures
* saved in the db already. */
if (channel->scid && public) {
cg->remote_sigs = tal(cg, struct remote_announce_sigs);
cg->remote_sigs->scid = *channel->scid;
if (!wallet_remote_ann_sigs_load(ld->wallet,
channel,
&cg->remote_sigs->node_sig,
&cg->remote_sigs->bitcoin_sig)) {
cg->remote_sigs = tal_free(cg->remote_sigs);
}
}
if (public)
cg->state = init_public_state(channel, cg->remote_sigs);
else
cg->state = CGOSSIP_PRIVATE;
check_channel_gossip(channel);
}
/* Something about channel changed: update if required */
void channel_gossip_update(struct channel *channel)
{
struct lightningd *ld = channel->peer->ld;
struct channel_gossip *cg = channel->channel_gossip;
/* Ignore unsaved channels */
if (!cg)
return;
switch (cg->state) {
case CGOSSIP_NOT_USABLE:
/* Change might make it usable */
if (!can_send_channel_update(channel)) {
check_channel_gossip(channel);
return;
}
set_gossip_state(channel, CGOSSIP_NOT_DEEP_ENOUGH);
/* fall thru */
case CGOSSIP_NOT_DEEP_ENOUGH:
/* Now we can send at non-forwardable update */
send_private_cupdate(channel, false);
/* Might have gotten straight from not-usable to announceable
* if we have a flurry of blocks, or minconf >= 6. */
if (!channel_announceable(channel, get_block_height(ld->topology))) {
check_channel_gossip(channel);
return;
}
set_gossip_state(channel, CGOSSIP_NEED_PEER_SIGS);
/* Could have actually already had sigs! */
if (cg->state == CGOSSIP_ANNOUNCED)
goto announced;
/* fall thru */
case CGOSSIP_PRIVATE:
case CGOSSIP_NEED_PEER_SIGS:
send_private_cupdate(channel, false);
check_channel_gossip(channel);
return;
case CGOSSIP_ANNOUNCED:
announced:
/* We don't penalize disconnected clients normally: we only
* do that if we actually try to send an htlc through */
broadcast_public_cupdate(channel, true);
check_channel_gossip(channel);
return;
}
fatal("Bad channel_gossip_state %u", channel->channel_gossip->state);
}
void channel_gossip_got_announcement_sigs(struct channel *channel,
struct short_channel_id scid,
const secp256k1_ecdsa_signature *node_sig,
const secp256k1_ecdsa_signature *bitcoin_sig)
{
/* Ignore unsaved channels */
if (!channel->channel_gossip) {
log_broken(channel->log, "They sent an announcement_signatures message for a unsaved channel? Ignoring.");
return;
}
switch (channel->channel_gossip->state) {
case CGOSSIP_PRIVATE:
log_unusual(channel->log, "They sent an announcement_signatures message for a private channel? Ignoring.");
u8 *warning = towire_warningfmt(NULL,
&channel->cid,
"You sent announcement_signatures for private channel");
msg_to_peer(channel->peer, take(warning));
return;
case CGOSSIP_NOT_USABLE:
case CGOSSIP_NOT_DEEP_ENOUGH:
/* They're early? */
stash_remote_announce_sigs(channel,
scid, node_sig, bitcoin_sig);
check_channel_gossip(channel);
return;
case CGOSSIP_NEED_PEER_SIGS:
stash_remote_announce_sigs(channel,
scid, node_sig, bitcoin_sig);
if (apply_remote_sigs(channel))
set_gossip_state(channel, CGOSSIP_ANNOUNCED);
check_channel_gossip(channel);
return;
case CGOSSIP_ANNOUNCED:
/* BOLT #7:
* - upon reconnection (once the above timing requirements
* have been met):
* - MUST respond to the first `announcement_signatures`
* message with its own `announcement_signatures` message.
*/
send_channel_announce_sigs(channel);
check_channel_gossip(channel);
return;
}
fatal("Bad channel_gossip_state %u", channel->channel_gossip->state);
}
/* Short channel id changed (splice, or reorg). */
void channel_gossip_scid_changed(struct channel *channel)
{
struct lightningd *ld = channel->peer->ld;
struct channel_gossip *cg = channel->channel_gossip;
/* Ignore unsaved channels */
if (!cg)
return;
/* Clear any cached update, we'll need a new one! */
cg->cupdate = tal_free(cg->cupdate);
/* Any announcement signatures we received for old scid are no longer
* valid. */
wallet_remote_ann_sigs_clear(ld->wallet, channel);
switch (cg->state) {
case CGOSSIP_PRIVATE:
/* Still private, just send new channel_update */
send_private_cupdate(channel, false);
check_channel_gossip(channel);
return;
case CGOSSIP_NOT_USABLE:
/* Shouldn't happen. */
return;
case CGOSSIP_NOT_DEEP_ENOUGH:
case CGOSSIP_NEED_PEER_SIGS:
case CGOSSIP_ANNOUNCED:
log_debug(channel->log, "channel_gossip: scid now %s",
fmt_short_channel_id(tmpctx, *channel->scid));
/* Start again. */
/* Maybe remote announcement signatures now apply? If not,
* free them */
if (cg->remote_sigs
&& !short_channel_id_eq(cg->remote_sigs->scid,
*channel->scid)) {
cg->remote_sigs = tal_free(cg->remote_sigs);
}
/* Stop refresh timer, we're not announcing the old one. */
cg->refresh_timer = tal_free(cg->refresh_timer);
set_gossip_state(channel,
init_public_state(channel, cg->remote_sigs));
send_channel_announce_sigs(channel);
check_channel_gossip(channel);
return;
}
fatal("Bad channel_gossip_state %u", cg->state);
}
/* Block height changed */
static void new_blockheight(struct lightningd *ld,
struct channel *channel,
u32 block_height)
{
switch (channel->channel_gossip->state) {
case CGOSSIP_PRIVATE:
case CGOSSIP_NEED_PEER_SIGS:
case CGOSSIP_ANNOUNCED:
case CGOSSIP_NOT_USABLE:
return;
case CGOSSIP_NOT_DEEP_ENOUGH:
if (!channel_announceable(channel, block_height)) {
check_channel_gossip(channel);
return;
}
set_gossip_state(channel, CGOSSIP_NEED_PEER_SIGS);
check_channel_gossip(channel);
return;
}
fatal("Bad channel_gossip_state %u", channel->channel_gossip->state);
}
void channel_gossip_notify_new_block(struct lightningd *ld,
u32 block_height)
{
struct peer *peer;
struct channel *channel;
struct peer_node_id_map_iter it;
for (peer = peer_node_id_map_first(ld->peers, &it);
peer;
peer = peer_node_id_map_next(ld->peers, &it)) {
list_for_each(&peer->channels, channel, list) {
/* Ignore unsaved channels */
if (!channel->channel_gossip)
continue;
new_blockheight(ld, channel, block_height);
check_channel_gossip(channel);
}
}
}
/* Gossipd told us about a channel update on one of our channels (on loading) */
void channel_gossip_update_from_gossipd(struct channel *channel,
const u8 *channel_update TAKES)
{
if (!channel->channel_gossip) {
log_broken(channel->log,
"gossipd gave channel_update for unsaved channel? update=%s",
tal_hex(tmpctx, channel_update));
return;
}
/* We might still want signatures from peer (we lost state?) */
switch (channel->channel_gossip->state) {
case CGOSSIP_PRIVATE:
log_broken(channel->log,
"gossipd gave channel_update for private channel? update=%s",
tal_hex(tmpctx, channel_update));
return;
/* This happens: we step back a block when restarting. We can
* fast-forward in this case. */
case CGOSSIP_NOT_DEEP_ENOUGH:
set_gossip_state(channel, CGOSSIP_NEED_PEER_SIGS);
check_channel_gossip(channel);
break;
case CGOSSIP_NOT_USABLE:
case CGOSSIP_NEED_PEER_SIGS:
if (taken(channel_update))
tal_free(channel_update);
log_broken(channel->log,
"gossipd gave us channel_update for channel in gossip_state %s",
channel_gossip_state_str(channel->channel_gossip->state));
return;
case CGOSSIP_ANNOUNCED:
break;
}
/* We don't set refresh timer if we're not ANNOUNCED, we're just saving updates
* for later! */
set_public_cupdate(channel, channel_update,
channel->channel_gossip->state == CGOSSIP_ANNOUNCED);
check_channel_gossip(channel);
}
static void set_not_starting_up(struct lightningd *ld)
{
starting_up = false;
log_debug(ld->log, "channel_gossip: no longer in startup mode");
/* Now we can create/update a node_announcement */
channel_gossip_node_announce(ld);
}
/* We also wait ten seconds *after* connection, for lease registration */
void channel_gossip_startup_done(struct lightningd *ld)
{
notleak(new_reltimer(ld->timers, ld,
time_from_sec(10),
set_not_starting_up, ld));
}
/* Gossipd init is done: if you expected a channel_update, be
* disappointed. */
void channel_gossip_init_done(struct lightningd *ld)
{
struct peer *peer;
struct channel *channel;
struct peer_node_id_map_iter it;
gossipd_init_done = true;
for (peer = peer_node_id_map_first(ld->peers, &it);
peer;
peer = peer_node_id_map_next(ld->peers, &it)) {
list_for_each(&peer->channels, channel, list) {
/* Ignore unsaved channels */
if (!channel->channel_gossip)
continue;
check_channel_gossip(channel);
if (channel->channel_gossip->cupdate)
continue;
if (channel->channel_gossip->state != CGOSSIP_ANNOUNCED)
continue;
/* gossipd lost announcement: re-create */
log_unusual(channel->log,
"gossipd lost track of announced channel: re-announcing!");
check_channel_gossip(channel);
send_channel_announcement(channel);
}
}
}
static void channel_reestablished_stable(struct channel *channel)
{
channel->stable_conn_timer = NULL;
channel->last_stable_connection = time_now().ts.tv_sec;
wallet_channel_save(channel->peer->ld->wallet, channel);
}
/* Peer has connected and successfully reestablished channel. */
void channel_gossip_channel_reestablished(struct channel *channel)
{
channel->reestablished = true;
tal_free(channel->stable_conn_timer);
channel->stable_conn_timer = new_reltimer(channel->peer->ld->timers,
channel, time_from_sec(60),
channel_reestablished_stable,
channel);
log_debug(channel->log, "channel_gossip: reestablished");
/* Ignore unsaved channels */
if (!channel->channel_gossip)
return;
switch (channel->channel_gossip->state) {
case CGOSSIP_NOT_USABLE:
return;
case CGOSSIP_PRIVATE:
case CGOSSIP_NOT_DEEP_ENOUGH:
send_private_cupdate(channel, true);
check_channel_gossip(channel);
return;
case CGOSSIP_NEED_PEER_SIGS:
/* BOLT #7:
* - upon reconnection (once the above timing
* requirements have been met):
* ...
* - if it has NOT received an
* `announcement_signatures` message:
* - SHOULD retransmit the
* `announcement_signatures` message.
*/
send_private_cupdate(channel, true);
send_channel_announce_sigs(channel);
check_channel_gossip(channel);
return;
case CGOSSIP_ANNOUNCED:
check_channel_gossip(channel);
return;
}
fatal("Bad channel_gossip_state %u", channel->channel_gossip->state);
}
void channel_gossip_channel_disconnect(struct channel *channel)
{
channel->stable_conn_timer = tal_free(channel->stable_conn_timer);
channel->reestablished = false;
}
/* We *could* send channel_updates for private channels, or
* unannounced. We do not */
const u8 *channel_gossip_update_for_error(const tal_t *ctx,
struct channel *channel)
{
/* We cannot ask this about unsaved channels. */
struct channel_gossip *cg = channel->channel_gossip;
switch (cg->state) {
case CGOSSIP_PRIVATE:
case CGOSSIP_NOT_USABLE:
case CGOSSIP_NOT_DEEP_ENOUGH:
case CGOSSIP_NEED_PEER_SIGS:
return NULL;
case CGOSSIP_ANNOUNCED:
broadcast_public_cupdate(channel, false);
check_channel_gossip(channel);
return cg->cupdate;
}
fatal("Bad channel_gossip_state %u", cg->state);
}
/* BOLT #7:
* - MUST set the `short_channel_id` to either an `alias` it has
* received from the peer, or the real channel `short_channel_id`.
*/
/* But we used to get this wrong! So this is the only place where we
* look up by *remote* id. It's not unique, but it is unique for a
* specific peer. */
static struct channel *lookup_by_peer_remote_alias(struct lightningd *ld,
const struct node_id *source,
struct short_channel_id scid)
{
const struct peer *p;
struct channel *chan;
if (!source)
return NULL;
p = peer_by_id(ld, source);
if (!p)
return NULL;
list_for_each(&p->channels, chan, list) {
if (chan->alias[REMOTE]
&& short_channel_id_eq(scid, *chan->alias[REMOTE])) {
return chan;
}
}
return NULL;
}
/* A peer sent gossipd an update_channel message for one of our channels.
* Gossipd checked the signature.
*/
void channel_gossip_set_remote_update(struct lightningd *ld,
const struct peer_update *update TAKES,
const struct node_id *source)
{
struct channel *channel;
struct channel_gossip *cg;
channel = any_channel_by_scid(ld, update->scid, true);