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lightning/channeld/channeld.c

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/* Main channel operation daemon: runs from funding_locked to shutdown_complete.
*
* We're fairly synchronous: our main loop looks for gossip, master or
* peer requests and services them synchronously.
*
* The exceptions are:
* 1. When we've asked the master something: in that case, we queue
* non-response packets for later processing while we await the reply.
* 2. We queue and send non-blocking responses to peers: if both peers were
* reading and writing synchronously we could deadlock if we hit buffer
* limits, unlikely as that is.
*/
#include <bitcoin/chainparams.h>
#include <bitcoin/privkey.h>
#include <bitcoin/script.h>
#include <ccan/cast/cast.h>
#include <ccan/container_of/container_of.h>
#include <ccan/crypto/hkdf_sha256/hkdf_sha256.h>
#include <ccan/crypto/shachain/shachain.h>
#include <ccan/err/err.h>
#include <ccan/fdpass/fdpass.h>
#include <ccan/mem/mem.h>
#include <ccan/take/take.h>
#include <ccan/tal/str/str.h>
#include <ccan/time/time.h>
#include <channeld/commit_tx.h>
#include <channeld/full_channel.h>
#include <channeld/gen_channel_wire.h>
#include <common/crypto_sync.h>
#include <common/dev_disconnect.h>
#include <common/features.h>
#include <common/gossip_constants.h>
#include <common/gossip_store.h>
#include <common/htlc_tx.h>
#include <common/key_derive.h>
#include <common/memleak.h>
#include <common/msg_queue.h>
#include <common/node_id.h>
#include <common/peer_billboard.h>
#include <common/peer_failed.h>
#include <common/ping.h>
#include <common/read_peer_msg.h>
#include <common/sphinx.h>
#include <common/status.h>
#include <common/subdaemon.h>
#include <common/timeout.h>
#include <common/type_to_string.h>
#include <common/version.h>
#include <common/wire_error.h>
#include <errno.h>
#include <fcntl.h>
#include <gossipd/gen_gossip_peerd_wire.h>
#include <hsmd/gen_hsm_wire.h>
#include <inttypes.h>
#include <secp256k1.h>
#include <stdio.h>
#include <wire/gen_onion_wire.h>
#include <wire/peer_wire.h>
#include <wire/wire.h>
#include <wire/wire_io.h>
#include <wire/wire_sync.h>
/* stdin == requests, 3 == peer, 4 = gossip, 5 = gossip_store, 6 = HSM */
#define MASTER_FD STDIN_FILENO
#define HSM_FD 6
struct peer {
struct per_peer_state *pps;
bool funding_locked[NUM_SIDES];
u64 next_index[NUM_SIDES];
/* Features peer supports. */
u8 *localfeatures;
/* Tolerable amounts for feerate (only relevant for fundee). */
u32 feerate_min, feerate_max;
/* Local next per-commit point. */
struct pubkey next_local_per_commit;
/* Remote's current per-commit point. */
struct pubkey remote_per_commit;
/* Remotes's last per-commitment point: we keep this to check
* revoke_and_ack's `per_commitment_secret` is correct. */
struct pubkey old_remote_per_commit;
/* Their sig for current commit. */
struct bitcoin_signature their_commit_sig;
/* BOLT #2:
*
* A sending node:
*...
* - for the first HTLC it offers:
* - MUST set `id` to 0.
*/
u64 htlc_id;
struct bitcoin_blkid chain_hash;
struct channel_id channel_id;
struct channel *channel;
/* Messages from master: we queue them since we might be
* waiting for a specific reply. */
struct msg_queue *from_master;
struct timers timers;
struct oneshot *commit_timer;
u64 commit_timer_attempts;
u32 commit_msec;
/* Are we expecting a pong? */
bool expecting_pong;
/* The feerate we want. */
u32 desired_feerate;
/* Announcement related information */
struct node_id node_ids[NUM_SIDES];
struct short_channel_id short_channel_ids[NUM_SIDES];
secp256k1_ecdsa_signature announcement_node_sigs[NUM_SIDES];
secp256k1_ecdsa_signature announcement_bitcoin_sigs[NUM_SIDES];
bool have_sigs[NUM_SIDES];
/* Which direction of the channel do we control? */
u16 channel_direction;
/* CLTV delta to announce to peers */
u16 cltv_delta;
u32 fee_base;
u32 fee_per_satoshi;
/* The scriptpubkey to use for shutting down. */
u8 *final_scriptpubkey;
/* If master told us to shut down */
bool send_shutdown;
/* Has shutdown been sent by each side? */
bool shutdown_sent[NUM_SIDES];
/* Information used for reestablishment. */
bool last_was_revoke;
struct changed_htlc *last_sent_commit;
u64 revocations_received;
u8 channel_flags;
bool announce_depth_reached;
bool channel_local_active;
/* Make sure timestamps move forward. */
u32 last_update_timestamp;
/* Make sure peer is live. */
struct timeabs last_recv;
/* Additional confirmations need for local lockin. */
u32 depth_togo;
/* Non-empty if they specified a fixed shutdown script */
u8 *remote_upfront_shutdown_script;
/* Empty commitments. Spec violation, but a minor one. */
u64 last_empty_commitment;
};
static u8 *create_channel_announcement(const tal_t *ctx, struct peer *peer);
static void start_commit_timer(struct peer *peer);
static void billboard_update(const struct peer *peer)
{
const char *funding_status, *announce_status, *shutdown_status;
if (peer->funding_locked[LOCAL] && peer->funding_locked[REMOTE])
funding_status = "Funding transaction locked.";
else if (!peer->funding_locked[LOCAL] && !peer->funding_locked[REMOTE])
funding_status = tal_fmt(tmpctx,
"Funding needs %d more confirmations for lockin.",
peer->depth_togo);
else if (peer->funding_locked[LOCAL] && !peer->funding_locked[REMOTE])
funding_status = "We've confirmed funding, they haven't yet.";
else if (!peer->funding_locked[LOCAL] && peer->funding_locked[REMOTE])
funding_status = "They've confirmed funding, we haven't yet.";
if (peer->have_sigs[LOCAL] && peer->have_sigs[REMOTE])
announce_status = " Channel announced.";
else if (peer->have_sigs[LOCAL] && !peer->have_sigs[REMOTE])
announce_status = " Waiting for their announcement signatures.";
else if (!peer->have_sigs[LOCAL] && peer->have_sigs[REMOTE])
announce_status = " They need our announcement signatures.";
else if (!peer->have_sigs[LOCAL] && !peer->have_sigs[REMOTE])
announce_status = "";
if (!peer->shutdown_sent[LOCAL] && !peer->shutdown_sent[REMOTE])
shutdown_status = "";
else if (!peer->shutdown_sent[LOCAL] && peer->shutdown_sent[REMOTE])
shutdown_status = " We've send shutdown, waiting for theirs";
else if (peer->shutdown_sent[LOCAL] && !peer->shutdown_sent[REMOTE])
shutdown_status = " They've sent shutdown, waiting for ours";
else if (peer->shutdown_sent[LOCAL] && peer->shutdown_sent[REMOTE]) {
size_t num_htlcs = num_channel_htlcs(peer->channel);
if (num_htlcs)
shutdown_status = tal_fmt(tmpctx,
" Shutdown messages exchanged,"
" waiting for %zu HTLCs to complete.",
num_htlcs);
else
shutdown_status = tal_fmt(tmpctx,
" Shutdown messages exchanged.");
}
peer_billboard(false, "%s%s%s", funding_status,
announce_status, shutdown_status);
}
static const u8 *hsm_req(const tal_t *ctx, const u8 *req TAKES)
{
u8 *msg;
int type = fromwire_peektype(req);
if (!wire_sync_write(HSM_FD, req))
status_failed(STATUS_FAIL_HSM_IO,
"Writing %s to HSM: %s",
hsm_wire_type_name(type),
strerror(errno));
msg = wire_sync_read(ctx, HSM_FD);
if (!msg)
status_failed(STATUS_FAIL_HSM_IO,
"Reading resp to %s: %s",
hsm_wire_type_name(type),
strerror(errno));
return msg;
}
/*
* The maximum msat that this node will accept for an htlc.
* It's flagged as an optional field in `channel_update`.
*
* We advertize the maximum value possible, defined as the smaller
* of the remote's maximum in-flight HTLC or the total channel
* capacity the reserve we have to keep.
* FIXME: does this need fuzz?
*/
static struct amount_msat advertized_htlc_max(const struct channel *channel)
{
struct amount_sat lower_bound;
struct amount_msat lower_bound_msat;
/* This shouldn't fail */
if (!amount_sat_sub(&lower_bound, channel->funding,
channel->config[REMOTE].channel_reserve)) {
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"funding %s - remote reserve %s?",
type_to_string(tmpctx, struct amount_sat,
&channel->funding),
type_to_string(tmpctx, struct amount_sat,
&channel->config[REMOTE]
.channel_reserve));
}
if (!amount_sat_to_msat(&lower_bound_msat, lower_bound)) {
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"lower_bound %s invalid?",
type_to_string(tmpctx, struct amount_sat,
&lower_bound));
}
if (amount_msat_greater(lower_bound_msat,
channel->chainparams->max_payment))
/* BOLT #7:
*
* The origin node:
* ...
* - if the `htlc_maximum_msat` field is present:
* ...
* - for channels with `chain_hash` identifying the Bitcoin blockchain:
* - MUST set this to less than 2^32.
*/
lower_bound_msat = channel->chainparams->max_payment;
return lower_bound_msat;
}
/* Create and send channel_update to gossipd (and maybe peer) */
static void send_channel_update(struct peer *peer, int disable_flag)
{
u8 *msg;
assert(disable_flag == 0 || disable_flag == ROUTING_FLAGS_DISABLED);
/* Only send an update if we told gossipd */
if (!peer->channel_local_active)
return;
assert(peer->short_channel_ids[LOCAL].u64);
msg = towire_gossipd_local_channel_update(NULL,
&peer->short_channel_ids[LOCAL],
disable_flag
== ROUTING_FLAGS_DISABLED,
peer->cltv_delta,
peer->channel->config[REMOTE].htlc_minimum,
peer->fee_base,
peer->fee_per_satoshi,
advertized_htlc_max(peer->channel));
wire_sync_write(peer->pps->gossip_fd, take(msg));
}
/**
* Add a channel locally and send a channel update to the peer
*
* Send a local_add_channel message to gossipd in order to make the channel
* usable locally, and also tell our peer about our parameters via a
* channel_update message. The peer may accept the update and use the contained
* information to route incoming payments through the channel. The
* channel_update is not preceeded by a channel_announcement and won't make much
* sense to other nodes, so we don't tell gossipd about it.
*/
static void make_channel_local_active(struct peer *peer)
{
u8 *msg;
/* Tell gossipd about local channel. */
msg = towire_gossipd_local_add_channel(NULL,
&peer->short_channel_ids[LOCAL],
&peer->node_ids[REMOTE],
peer->channel->funding);
wire_sync_write(peer->pps->gossip_fd, take(msg));
/* Tell gossipd and the other side what parameters we expect should
* they route through us */
send_channel_update(peer, 0);
}
static void send_announcement_signatures(struct peer *peer)
{
/* First 2 + 256 byte are the signatures and msg type, skip them */
size_t offset = 258;
struct sha256_double hash;
const u8 *msg, *ca, *req;
struct pubkey mykey;
status_debug("Exchanging announcement signatures.");
ca = create_channel_announcement(tmpctx, peer);
req = towire_hsm_cannouncement_sig_req(tmpctx, ca);
msg = hsm_req(tmpctx, req);
if (!fromwire_hsm_cannouncement_sig_reply(msg,
&peer->announcement_node_sigs[LOCAL],
&peer->announcement_bitcoin_sigs[LOCAL]))
status_failed(STATUS_FAIL_HSM_IO,
"Reading cannouncement_sig_resp: %s",
strerror(errno));
/* Double-check that HSM gave valid signatures. */
sha256_double(&hash, ca + offset, tal_count(ca) - offset);
if (!pubkey_from_node_id(&mykey, &peer->node_ids[LOCAL]))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Could not convert my id '%s' to pubkey",
type_to_string(tmpctx, struct node_id,
&peer->node_ids[LOCAL]));
if (!check_signed_hash(&hash, &peer->announcement_node_sigs[LOCAL],
&mykey)) {
/* It's ok to fail here, the channel announcement is
* unique, unlike the channel update which may have
* been replaced in the meantime. */
status_failed(STATUS_FAIL_HSM_IO,
"HSM returned an invalid node signature");
}
if (!check_signed_hash(&hash, &peer->announcement_bitcoin_sigs[LOCAL],
&peer->channel->funding_pubkey[LOCAL])) {
/* It's ok to fail here, the channel announcement is
* unique, unlike the channel update which may have
* been replaced in the meantime. */
status_failed(STATUS_FAIL_HSM_IO,
"HSM returned an invalid bitcoin signature");
}
msg = towire_announcement_signatures(
NULL, &peer->channel_id, &peer->short_channel_ids[LOCAL],
&peer->announcement_node_sigs[LOCAL],
&peer->announcement_bitcoin_sigs[LOCAL]);
sync_crypto_write(peer->pps, take(msg));
}
/* Tentatively create a channel_announcement, possibly with invalid
* signatures. The signatures need to be collected first, by asking
* the HSM and by exchanging announcement_signature messages. */
static u8 *create_channel_announcement(const tal_t *ctx, struct peer *peer)
{
int first, second;
u8 *cannounce, *features = tal_arr(ctx, u8, 0);
if (peer->channel_direction == 0) {
first = LOCAL;
second = REMOTE;
} else {
first = REMOTE;
second = LOCAL;
}
cannounce = towire_channel_announcement(
ctx, &peer->announcement_node_sigs[first],
&peer->announcement_node_sigs[second],
&peer->announcement_bitcoin_sigs[first],
&peer->announcement_bitcoin_sigs[second],
features,
&peer->chain_hash,
&peer->short_channel_ids[LOCAL],
&peer->node_ids[first],
&peer->node_ids[second],
&peer->channel->funding_pubkey[first],
&peer->channel->funding_pubkey[second]);
tal_free(features);
return cannounce;
}
/* Once we have both, we'd better make sure we agree what they are! */
static void check_short_ids_match(struct peer *peer)
{
assert(peer->have_sigs[LOCAL]);
assert(peer->have_sigs[REMOTE]);
if (!short_channel_id_eq(&peer->short_channel_ids[LOCAL],
&peer->short_channel_ids[REMOTE]))
peer_failed(peer->pps,
&peer->channel_id,
"We disagree on short_channel_ids:"
" I have %s, you say %s",
type_to_string(peer, struct short_channel_id,
&peer->short_channel_ids[LOCAL]),
type_to_string(peer, struct short_channel_id,
&peer->short_channel_ids[REMOTE]));
}
static void announce_channel(struct peer *peer)
{
u8 *cannounce;
cannounce = create_channel_announcement(tmpctx, peer);
wire_sync_write(peer->pps->gossip_fd, cannounce);
send_channel_update(peer, 0);
}
static void channel_announcement_negotiate(struct peer *peer)
{
/* Don't do any announcement work if we're shutting down */
if (peer->shutdown_sent[LOCAL])
return;
/* Can't do anything until funding is locked. */
if (!peer->funding_locked[LOCAL] || !peer->funding_locked[REMOTE])
return;
if (!peer->channel_local_active) {
peer->channel_local_active = true;
make_channel_local_active(peer);
}
/* BOLT #7:
*
* A node:
* - if the `open_channel` message has the `announce_channel` bit set AND a `shutdown` message has not been sent:
* - MUST send the `announcement_signatures` message.
* - MUST NOT send `announcement_signatures` messages until `funding_locked`
* has been sent and received AND the funding transaction has at least six confirmations.
* - otherwise:
* - MUST NOT send the `announcement_signatures` message.
*/
if (!(peer->channel_flags & CHANNEL_FLAGS_ANNOUNCE_CHANNEL))
return;
/* BOLT #7:
*
* - MUST NOT send `announcement_signatures` messages until `funding_locked`
* has been sent and received AND the funding transaction has at least six confirmations.
*/
if (peer->announce_depth_reached && !peer->have_sigs[LOCAL]) {
/* When we reenable the channel, we will also send the announcement to remote peer, and
* receive the remote announcement reply. But we will rebuild the channel with announcement
* from the DB directly, other than waiting for the remote announcement reply.
*/
send_announcement_signatures(peer);
peer->have_sigs[LOCAL] = true;
billboard_update(peer);
}
/* If we've completed the signature exchange, we can send a real
* announcement, otherwise we send a temporary one */
if (peer->have_sigs[LOCAL] && peer->have_sigs[REMOTE]) {
check_short_ids_match(peer);
/* After making sure short_channel_ids match, we can send remote
* announcement to MASTER. */
wire_sync_write(MASTER_FD,
take(towire_channel_got_announcement(NULL,
&peer->announcement_node_sigs[REMOTE],
&peer->announcement_bitcoin_sigs[REMOTE])));
/* Give other nodes time to notice new block. */
notleak(new_reltimer(&peer->timers, peer,
time_from_sec(GOSSIP_ANNOUNCE_DELAY(dev_fast_gossip)),
announce_channel, peer));
}
}
static void handle_peer_funding_locked(struct peer *peer, const u8 *msg)
{
struct channel_id chanid;
/* BOLT #2:
*
* A node:
*...
* - upon reconnection:
* - MUST ignore any redundant `funding_locked` it receives.
*/
if (peer->funding_locked[REMOTE])
return;
/* Too late, we're shutting down! */
if (peer->shutdown_sent[LOCAL])
return;
peer->old_remote_per_commit = peer->remote_per_commit;
if (!fromwire_funding_locked(msg, &chanid,
&peer->remote_per_commit))
peer_failed(peer->pps,
&peer->channel_id,
"Bad funding_locked %s", tal_hex(msg, msg));
if (!channel_id_eq(&chanid, &peer->channel_id))
peer_failed(peer->pps,
&peer->channel_id,
"Wrong channel id in %s (expected %s)",
tal_hex(tmpctx, msg),
type_to_string(msg, struct channel_id,
&peer->channel_id));
peer->funding_locked[REMOTE] = true;
wire_sync_write(MASTER_FD,
take(towire_channel_got_funding_locked(NULL,
&peer->remote_per_commit)));
channel_announcement_negotiate(peer);
billboard_update(peer);
}
static void handle_peer_announcement_signatures(struct peer *peer, const u8 *msg)
{
struct channel_id chanid;
if (!fromwire_announcement_signatures(msg,
&chanid,
&peer->short_channel_ids[REMOTE],
&peer->announcement_node_sigs[REMOTE],
&peer->announcement_bitcoin_sigs[REMOTE]))
peer_failed(peer->pps,
&peer->channel_id,
"Bad announcement_signatures %s",
tal_hex(msg, msg));
/* Make sure we agree on the channel ids */
if (!channel_id_eq(&chanid, &peer->channel_id)) {
peer_failed(peer->pps,
&peer->channel_id,
"Wrong channel_id: expected %s, got %s",
type_to_string(tmpctx, struct channel_id,
&peer->channel_id),
type_to_string(tmpctx, struct channel_id, &chanid));
}
peer->have_sigs[REMOTE] = true;
billboard_update(peer);
channel_announcement_negotiate(peer);
}
static struct secret *get_shared_secret(const tal_t *ctx,
const struct htlc *htlc,
enum onion_type *why_bad,
struct sha256 *next_onion_sha)
{
struct onionpacket *op;
struct secret *secret = tal(ctx, struct secret);
const u8 *msg;
struct route_step *rs;
/* We unwrap the onion now. */
op = parse_onionpacket(tmpctx, htlc->routing, TOTAL_PACKET_SIZE,
why_bad);
if (!op)
return tal_free(secret);
/* Because wire takes struct pubkey. */
msg = hsm_req(tmpctx, towire_hsm_ecdh_req(tmpctx, &op->ephemeralkey));
if (!fromwire_hsm_ecdh_resp(msg, secret))
status_failed(STATUS_FAIL_HSM_IO, "Reading ecdh response");
/* We make sure we can parse onion packet, so we know if shared secret
* is actually valid (this checks hmac). */
rs = process_onionpacket(tmpctx, op, secret->data,
htlc->rhash.u.u8,
sizeof(htlc->rhash));
if (!rs) {
*why_bad = WIRE_INVALID_ONION_HMAC;
return tal_free(secret);
}
/* Calculate sha256 we'll hand to next peer, in case they complain. */
msg = serialize_onionpacket(tmpctx, rs->next);
sha256(next_onion_sha, msg, tal_bytelen(msg));
return secret;
}
static void handle_peer_add_htlc(struct peer *peer, const u8 *msg)
{
struct channel_id channel_id;
u64 id;
struct amount_msat amount;
u32 cltv_expiry;
struct sha256 payment_hash;
u8 onion_routing_packet[TOTAL_PACKET_SIZE];
enum channel_add_err add_err;
struct htlc *htlc;
if (!fromwire_update_add_htlc(msg, &channel_id, &id, &amount,
&payment_hash, &cltv_expiry,
onion_routing_packet))
peer_failed(peer->pps,
&peer->channel_id,
"Bad peer_add_htlc %s", tal_hex(msg, msg));
add_err = channel_add_htlc(peer->channel, REMOTE, id, amount,
cltv_expiry, &payment_hash,
onion_routing_packet, &htlc, NULL);
if (add_err != CHANNEL_ERR_ADD_OK)
peer_failed(peer->pps,
&peer->channel_id,
"Bad peer_add_htlc: %s",
channel_add_err_name(add_err));
/* If this is wrong, we don't complain yet; when it's confirmed we'll
* send it to the master which handles all HTLC failures. */
htlc->shared_secret = get_shared_secret(htlc, htlc,
&htlc->why_bad_onion,
&htlc->next_onion_sha);
}
static void handle_peer_feechange(struct peer *peer, const u8 *msg)
{
struct channel_id channel_id;
u32 feerate;
if (!fromwire_update_fee(msg, &channel_id, &feerate)) {
peer_failed(peer->pps,
&peer->channel_id,
"Bad update_fee %s", tal_hex(msg, msg));
}
/* BOLT #2:
*
* A receiving node:
*...
* - if the sender is not responsible for paying the Bitcoin fee:
* - MUST fail the channel.
*/
if (peer->channel->funder != REMOTE)
peer_failed(peer->pps,
&peer->channel_id,
"update_fee from non-funder?");
status_debug("update_fee %u, range %u-%u",
feerate, peer->feerate_min, peer->feerate_max);
/* BOLT #2:
*
* A receiving node:
* - if the `update_fee` is too low for timely processing, OR is
* unreasonably large:
* - SHOULD fail the channel.
*/
if (feerate < peer->feerate_min || feerate > peer->feerate_max)
peer_failed(peer->pps,
&peer->channel_id,
"update_fee %u outside range %u-%u",
feerate, peer->feerate_min, peer->feerate_max);
/* BOLT #2:
*
* - if the sender cannot afford the new fee rate on the receiving
* node's current commitment transaction:
* - SHOULD fail the channel,
* - but MAY delay this check until the `update_fee` is committed.
*/
if (!channel_update_feerate(peer->channel, feerate))
peer_failed(peer->pps,
&peer->channel_id,
"update_fee %u unaffordable",
feerate);
status_debug("peer updated fee to %u", feerate);
}
static struct changed_htlc *changed_htlc_arr(const tal_t *ctx,
const struct htlc **changed_htlcs)
{
struct changed_htlc *changed;
size_t i;
changed = tal_arr(ctx, struct changed_htlc, tal_count(changed_htlcs));
for (i = 0; i < tal_count(changed_htlcs); i++) {
changed[i].id = changed_htlcs[i]->id;
changed[i].newstate = changed_htlcs[i]->state;
}
return changed;
}
static u8 *sending_commitsig_msg(const tal_t *ctx,
u64 remote_commit_index,
u32 remote_feerate,
const struct htlc **changed_htlcs,
const struct bitcoin_signature *commit_sig,
const secp256k1_ecdsa_signature *htlc_sigs)
{
struct changed_htlc *changed;
u8 *msg;
/* We tell master what (of our) HTLCs peer will now be
* committed to. */
changed = changed_htlc_arr(tmpctx, changed_htlcs);
msg = towire_channel_sending_commitsig(ctx, remote_commit_index,
remote_feerate,
changed, commit_sig, htlc_sigs);
return msg;
}
static bool shutdown_complete(const struct peer *peer)
{
return peer->shutdown_sent[LOCAL]
&& peer->shutdown_sent[REMOTE]
&& num_channel_htlcs(peer->channel) == 0
/* We could be awaiting revoke-and-ack for a feechange */
&& peer->revocations_received == peer->next_index[REMOTE] - 1;
}
/* BOLT #2:
*
* A sending node:
*...
* - if there are updates pending on the receiving node's commitment
* transaction:
* - MUST NOT send a `shutdown`.
*/
/* So we only call this after reestablish or immediately after sending commit */
static void maybe_send_shutdown(struct peer *peer)
{
u8 *msg;
if (!peer->send_shutdown)
return;
/* Send a disable channel_update so others don't try to route
* over us */
send_channel_update(peer, ROUTING_FLAGS_DISABLED);
msg = towire_shutdown(NULL, &peer->channel_id, peer->final_scriptpubkey);
sync_crypto_write(peer->pps, take(msg));
peer->send_shutdown = false;
peer->shutdown_sent[LOCAL] = true;
billboard_update(peer);
}
/* This queues other traffic from the fd until we get reply. */
static u8 *master_wait_sync_reply(const tal_t *ctx,
struct peer *peer,
const u8 *msg,
int replytype)
{
u8 *reply;
status_debug("Sending master %u", fromwire_peektype(msg));
if (!wire_sync_write(MASTER_FD, msg))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Could not set sync write to master: %s",
strerror(errno));
status_debug("... , awaiting %u", replytype);
for (;;) {
int type;
reply = wire_sync_read(ctx, MASTER_FD);
if (!reply)
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Could not set sync read from master: %s",
strerror(errno));
type = fromwire_peektype(reply);
if (type == replytype) {
status_debug("Got it!");
break;
}
status_debug("Nope, got %u instead", type);
msg_enqueue(peer->from_master, take(reply));
}
return reply;
}
static u8 *gossipd_wait_sync_reply(const tal_t *ctx,
struct peer *peer, const u8 *msg,
enum gossip_peerd_wire_type replytype)
{
/* We can forward gossip packets while waiting for our reply. */
u8 *reply;
status_debug("Sending gossipd %u", fromwire_peektype(msg));
wire_sync_write(peer->pps->gossip_fd, msg);
status_debug("... , awaiting %u", replytype);
for (;;) {
int type;
reply = wire_sync_read(tmpctx, peer->pps->gossip_fd);
/* Gossipd hangs up on us to kill us when a new
* connection comes in. */
if (!reply)
peer_failed_connection_lost();
type = fromwire_peektype(reply);
if (type == replytype) {
status_debug("Got it!");
break;
}
handle_gossip_msg(peer->pps, take(reply));
}
return reply;
}
static u8 *foreign_channel_update(const tal_t *ctx,
struct peer *peer,
const struct short_channel_id *scid)
{
u8 *msg, *update, *channel_update;
msg = towire_gossipd_get_update(NULL, scid);
msg = gossipd_wait_sync_reply(tmpctx, peer, take(msg),
WIRE_GOSSIPD_GET_UPDATE_REPLY);
if (!fromwire_gossipd_get_update_reply(ctx, msg, &update))
status_failed(STATUS_FAIL_GOSSIP_IO,
"Invalid update reply");
/* Strip the type from the channel_update. Due to the specification
* being underspecified, some implementations skipped the type
* prefix. Since we are in the minority we adapt (See #1730 and
* lightningnetwork/lnd#1599 for details). */
if (update && fromwire_peektype(update) == WIRE_CHANNEL_UPDATE) {
assert(tal_bytelen(update) > 2);
channel_update = tal_arr(ctx, u8, 0);
towire(&channel_update, update + 2, tal_bytelen(update) - 2);
tal_free(update);
return channel_update;
} else {
return update;
}
}
static u8 *make_failmsg(const tal_t *ctx,
struct peer *peer,
const struct htlc *htlc,
enum onion_type failcode,
const struct short_channel_id *scid,
const struct sha256 *sha256,
u32 failheight)
{
u8 *msg, *channel_update = NULL;
u32 cltv_expiry = abs_locktime_to_blocks(&htlc->expiry);
switch (failcode) {
case WIRE_INVALID_REALM:
msg = towire_invalid_realm(ctx);
goto done;
case WIRE_TEMPORARY_NODE_FAILURE:
msg = towire_temporary_node_failure(ctx);
goto done;
case WIRE_PERMANENT_NODE_FAILURE:
msg = towire_permanent_node_failure(ctx);
goto done;
case WIRE_REQUIRED_NODE_FEATURE_MISSING:
msg = towire_required_node_feature_missing(ctx);
goto done;
case WIRE_TEMPORARY_CHANNEL_FAILURE:
channel_update = foreign_channel_update(ctx, peer, scid);
msg = towire_temporary_channel_failure(ctx, channel_update);
goto done;
case WIRE_CHANNEL_DISABLED:
msg = towire_channel_disabled(ctx);
goto done;
case WIRE_PERMANENT_CHANNEL_FAILURE:
msg = towire_permanent_channel_failure(ctx);
goto done;
case WIRE_REQUIRED_CHANNEL_FEATURE_MISSING:
msg = towire_required_channel_feature_missing(ctx);
goto done;
case WIRE_UNKNOWN_NEXT_PEER:
msg = towire_unknown_next_peer(ctx);
goto done;
case WIRE_AMOUNT_BELOW_MINIMUM:
channel_update = foreign_channel_update(ctx, peer, scid);
msg = towire_amount_below_minimum(ctx, htlc->amount,
channel_update);
goto done;
case WIRE_FEE_INSUFFICIENT:
channel_update = foreign_channel_update(ctx, peer, scid);
msg = towire_fee_insufficient(ctx, htlc->amount,
channel_update);
goto done;
case WIRE_INCORRECT_CLTV_EXPIRY:
channel_update = foreign_channel_update(ctx, peer, scid);
msg = towire_incorrect_cltv_expiry(ctx, cltv_expiry,
channel_update);
goto done;
case WIRE_EXPIRY_TOO_SOON:
channel_update = foreign_channel_update(ctx, peer, scid);
msg = towire_expiry_too_soon(ctx, channel_update);
goto done;
case WIRE_EXPIRY_TOO_FAR:
msg = towire_expiry_too_far(ctx);
goto done;
case WIRE_INCORRECT_OR_UNKNOWN_PAYMENT_DETAILS:
assert(failheight);
msg = towire_incorrect_or_unknown_payment_details(
ctx, htlc->amount, failheight);
goto done;
case WIRE_FINAL_INCORRECT_CLTV_EXPIRY:
msg = towire_final_incorrect_cltv_expiry(ctx, cltv_expiry);
goto done;
case WIRE_FINAL_INCORRECT_HTLC_AMOUNT:
msg = towire_final_incorrect_htlc_amount(ctx, htlc->amount);
goto done;
case WIRE_INVALID_ONION_VERSION:
msg = towire_invalid_onion_version(ctx, sha256);
goto done;
case WIRE_INVALID_ONION_HMAC:
msg = towire_invalid_onion_hmac(ctx, sha256);
goto done;
case WIRE_INVALID_ONION_KEY:
msg = towire_invalid_onion_key(ctx, sha256);
goto done;
case WIRE_INVALID_ONION_PAYLOAD:
/* FIXME: wire this into tlv parser somehow. */
msg = towire_invalid_onion_payload(ctx, 0, 0);
goto done;
}
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Asked to create failmsg %u (%s)",
failcode, onion_type_name(failcode));
done:
tal_free(channel_update);
return msg;
}
/* Returns HTLC sigs, sets commit_sig */
static secp256k1_ecdsa_signature *calc_commitsigs(const tal_t *ctx,
const struct peer *peer,
u64 commit_index,
struct bitcoin_signature *commit_sig)
{
size_t i;
struct bitcoin_tx **txs;
const u8 **wscripts;
const struct htlc **htlc_map;
struct pubkey local_htlckey;
const u8 *msg;
secp256k1_ecdsa_signature *htlc_sigs;
txs = channel_txs(tmpctx, peer->channel->chainparams, &htlc_map,
&wscripts, peer->channel, &peer->remote_per_commit,
commit_index, REMOTE);
msg = towire_hsm_sign_remote_commitment_tx(NULL, txs[0],
&peer->channel->funding_pubkey[REMOTE],
*txs[0]->input_amounts[0]);
msg = hsm_req(tmpctx, take(msg));
if (!fromwire_hsm_sign_tx_reply(msg, commit_sig))
status_failed(STATUS_FAIL_HSM_IO,
"Reading sign_remote_commitment_tx reply: %s",
tal_hex(tmpctx, msg));
status_debug("Creating commit_sig signature %"PRIu64" %s for tx %s wscript %s key %s",
commit_index,
type_to_string(tmpctx, struct bitcoin_signature,
commit_sig),
type_to_string(tmpctx, struct bitcoin_tx, txs[0]),
tal_hex(tmpctx, wscripts[0]),
type_to_string(tmpctx, struct pubkey,
&peer->channel->funding_pubkey[LOCAL]));
dump_htlcs(peer->channel, "Sending commit_sig");
if (!derive_simple_key(&peer->channel->basepoints[LOCAL].htlc,
&peer->remote_per_commit,
&local_htlckey))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Deriving local_htlckey");
/* BOLT #2:
*
* A sending node:
*...
* - MUST include one `htlc_signature` for every HTLC transaction
* corresponding to the ordering of the commitment transaction
*/
htlc_sigs = tal_arr(ctx, secp256k1_ecdsa_signature, tal_count(txs) - 1);
for (i = 0; i < tal_count(htlc_sigs); i++) {
struct bitcoin_signature sig;
msg = towire_hsm_sign_remote_htlc_tx(NULL, txs[i + 1],
wscripts[i + 1],
*txs[i+1]->input_amounts[0],
&peer->remote_per_commit);
msg = hsm_req(tmpctx, take(msg));
if (!fromwire_hsm_sign_tx_reply(msg, &sig))
status_failed(STATUS_FAIL_HSM_IO,
"Bad sign_remote_htlc_tx reply: %s",
tal_hex(tmpctx, msg));
htlc_sigs[i] = sig.s;
status_debug("Creating HTLC signature %s for tx %s wscript %s key %s",
type_to_string(tmpctx, struct bitcoin_signature,
&sig),
type_to_string(tmpctx, struct bitcoin_tx, txs[1+i]),
tal_hex(tmpctx, wscripts[1+i]),
type_to_string(tmpctx, struct pubkey,
&local_htlckey));
assert(check_tx_sig(txs[1+i], 0, NULL, wscripts[1+i],
&local_htlckey,
&sig));
}
return htlc_sigs;
}
/* Have we received something from peer recently? */
static bool peer_recently_active(struct peer *peer)
{
return time_less(time_between(time_now(), peer->last_recv),
time_from_sec(30));
}
static void maybe_send_ping(struct peer *peer)
{
/* Already have a ping in flight? */
if (peer->expecting_pong)
return;
if (peer_recently_active(peer))
return;
/* Send a ping to try to elicit a receive. */
sync_crypto_write_no_delay(peer->pps, take(make_ping(NULL, 1, 0)));
peer->expecting_pong = true;
}
static void send_commit(struct peer *peer)
{
u8 *msg;
const struct htlc **changed_htlcs;
struct bitcoin_signature commit_sig;
secp256k1_ecdsa_signature *htlc_sigs;
#if DEVELOPER
/* Hack to suppress all commit sends if dev_disconnect says to */
if (dev_suppress_commit) {
peer->commit_timer = NULL;
return;
}
#endif
/* FIXME: Document this requirement in BOLT 2! */
/* We can't send two commits in a row. */
if (peer->revocations_received != peer->next_index[REMOTE] - 1) {
assert(peer->revocations_received
== peer->next_index[REMOTE] - 2);
peer->commit_timer_attempts++;
/* Only report this in extreme cases */
if (peer->commit_timer_attempts % 100 == 0)
status_debug("Can't send commit:"
" waiting for revoke_and_ack with %"
PRIu64" attempts",
peer->commit_timer_attempts);
/* Mark this as done and try again. */
peer->commit_timer = NULL;
start_commit_timer(peer);
return;
}
/* BOLT #2:
*
* - if no HTLCs remain in either commitment transaction:
* - MUST NOT send any `update` message after a `shutdown`.
*/
if (peer->shutdown_sent[LOCAL] && !num_channel_htlcs(peer->channel)) {
status_debug("Can't send commit: final shutdown phase");
peer->commit_timer = NULL;
return;
}
/* If we haven't received a packet for > 30 seconds, delay. */
if (!peer_recently_active(peer)) {
/* Mark this as done and try again. */
peer->commit_timer = NULL;
start_commit_timer(peer);
return;
}
/* If we wanted to update fees, do it now. */
if (peer->channel->funder == LOCAL) {
u32 feerate, max = approx_max_feerate(peer->channel);
feerate = peer->desired_feerate;
/* FIXME: We should avoid adding HTLCs until we can meet this
* feerate! */
if (feerate > max)
feerate = max;
if (feerate != channel_feerate(peer->channel, REMOTE)) {
u8 *msg;
if (!channel_update_feerate(peer->channel, feerate))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Could not afford feerate %u"
" (vs max %u)",
feerate, max);
msg = towire_update_fee(NULL, &peer->channel_id,
feerate);
sync_crypto_write(peer->pps, take(msg));
}
}
/* BOLT #2:
*
* A sending node:
* - MUST NOT send a `commitment_signed` message that does not include
* any updates.
*/
changed_htlcs = tal_arr(tmpctx, const struct htlc *, 0);
if (!channel_sending_commit(peer->channel, &changed_htlcs)) {
status_debug("Can't send commit: nothing to send");
/* Covers the case where we've just been told to shutdown. */
maybe_send_shutdown(peer);
peer->commit_timer = NULL;
return;
}
htlc_sigs = calc_commitsigs(tmpctx, peer, peer->next_index[REMOTE],
&commit_sig);
status_debug("Telling master we're about to commit...");
/* Tell master to save this next commit to database, then wait. */
msg = sending_commitsig_msg(NULL, peer->next_index[REMOTE],
channel_feerate(peer->channel, REMOTE),
changed_htlcs,
&commit_sig,
htlc_sigs);
/* Message is empty; receiving it is the point. */
master_wait_sync_reply(tmpctx, peer, take(msg),
WIRE_CHANNEL_SENDING_COMMITSIG_REPLY);
status_debug("Sending commit_sig with %zu htlc sigs",
tal_count(htlc_sigs));
peer->next_index[REMOTE]++;
msg = towire_commitment_signed(NULL, &peer->channel_id,
&commit_sig.s,
htlc_sigs);
sync_crypto_write_no_delay(peer->pps, take(msg));
maybe_send_shutdown(peer);
/* Timer now considered expired, you can add a new one. */
peer->commit_timer = NULL;
start_commit_timer(peer);
}
static void start_commit_timer(struct peer *peer)
{
/* We should send a ping now if we need a liveness check. */
maybe_send_ping(peer);
/* Already armed? */
if (peer->commit_timer)
return;
peer->commit_timer_attempts = 0;
peer->commit_timer = new_reltimer(&peer->timers, peer,
time_from_msec(peer->commit_msec),
send_commit, peer);
}
/* If old_secret is NULL, we don't care, otherwise it is filled in. */
static void get_per_commitment_point(u64 index, struct pubkey *point,
struct secret *old_secret)
{
struct secret *s;
const u8 *msg;
msg = hsm_req(tmpctx,
take(towire_hsm_get_per_commitment_point(NULL, index)));
if (!fromwire_hsm_get_per_commitment_point_reply(tmpctx, msg,
point,
&s))
status_failed(STATUS_FAIL_HSM_IO,
"Bad per_commitment_point reply %s",
tal_hex(tmpctx, msg));
if (old_secret) {
if (!s)
status_failed(STATUS_FAIL_HSM_IO,
"No secret in per_commitment_point_reply %"
PRIu64,
index);
*old_secret = *s;
}
}
/* revoke_index == current index - 1 (usually; not for retransmission) */
static u8 *make_revocation_msg(const struct peer *peer, u64 revoke_index,
struct pubkey *point)
{
struct secret old_commit_secret;
get_per_commitment_point(revoke_index+2, point, &old_commit_secret);
return towire_revoke_and_ack(peer, &peer->channel_id, &old_commit_secret,
point);
}
static void send_revocation(struct peer *peer)
{
/* Revoke previous commit, get new point. */
u8 *msg = make_revocation_msg(peer, peer->next_index[LOCAL]-1,
&peer->next_local_per_commit);
/* From now on we apply changes to the next commitment */
peer->next_index[LOCAL]++;
/* If this queues more changes on the other end, send commit. */
if (channel_sending_revoke_and_ack(peer->channel)) {
status_debug("revoke_and_ack made pending: commit timer");
start_commit_timer(peer);
}
sync_crypto_write_no_delay(peer->pps, take(msg));
}
static u8 *got_commitsig_msg(const tal_t *ctx,
u64 local_commit_index,
u32 local_feerate,
const struct bitcoin_signature *commit_sig,
const secp256k1_ecdsa_signature *htlc_sigs,
const struct htlc **changed_htlcs,
const struct bitcoin_tx *committx)
{
struct changed_htlc *changed;
struct fulfilled_htlc *fulfilled;
const struct failed_htlc **failed;
struct added_htlc *added;
struct secret *shared_secret;
u8 *msg;
changed = tal_arr(tmpctx, struct changed_htlc, 0);
added = tal_arr(tmpctx, struct added_htlc, 0);
shared_secret = tal_arr(tmpctx, struct secret, 0);
failed = tal_arr(tmpctx, const struct failed_htlc *, 0);
fulfilled = tal_arr(tmpctx, struct fulfilled_htlc, 0);
for (size_t i = 0; i < tal_count(changed_htlcs); i++) {
const struct htlc *htlc = changed_htlcs[i];
if (htlc->state == RCVD_ADD_COMMIT) {
struct added_htlc a;
struct secret s;
a.id = htlc->id;
a.amount = htlc->amount;
a.payment_hash = htlc->rhash;
a.cltv_expiry = abs_locktime_to_blocks(&htlc->expiry);
memcpy(a.onion_routing_packet,
htlc->routing,
sizeof(a.onion_routing_packet));
/* Invalid shared secret gets set to all-zero: our
* code generator can't make arrays of optional values */
if (!htlc->shared_secret)
memset(&s, 0, sizeof(s));
else
s = *htlc->shared_secret;
tal_arr_expand(&added, a);
tal_arr_expand(&shared_secret, s);
} else if (htlc->state == RCVD_REMOVE_COMMIT) {
if (htlc->r) {
struct fulfilled_htlc f;
assert(!htlc->fail && !htlc->failcode);
f.id = htlc->id;
f.payment_preimage = *htlc->r;
tal_arr_expand(&fulfilled, f);
} else {
struct failed_htlc *f;
assert(htlc->fail || htlc->failcode);
f = tal(failed, struct failed_htlc);
f->id = htlc->id;
f->failcode = htlc->failcode;
f->failreason = cast_const(u8 *, htlc->fail);
f->scid = cast_const(struct short_channel_id *,
htlc->failed_scid);
tal_arr_expand(&failed, f);
}
} else {
struct changed_htlc c;
assert(htlc->state == RCVD_REMOVE_ACK_COMMIT
|| htlc->state == RCVD_ADD_ACK_COMMIT);
c.id = htlc->id;
c.newstate = htlc->state;
tal_arr_expand(&changed, c);
}
}
msg = towire_channel_got_commitsig(ctx, local_commit_index,
local_feerate,
commit_sig,
htlc_sigs,
added,
shared_secret,
fulfilled,
failed,
changed,
committx);
return msg;
}
static void handle_peer_commit_sig(struct peer *peer, const u8 *msg)
{
struct channel_id channel_id;
struct bitcoin_signature commit_sig;
secp256k1_ecdsa_signature *htlc_sigs;
struct pubkey remote_htlckey;
struct bitcoin_tx **txs;
const struct htlc **htlc_map, **changed_htlcs;
const u8 **wscripts;
size_t i;
changed_htlcs = tal_arr(msg, const struct htlc *, 0);
if (!channel_rcvd_commit(peer->channel, &changed_htlcs)) {
/* BOLT #2:
*
* A sending node:
* - MUST NOT send a `commitment_signed` message that does not
* include any updates.
*/
status_debug("Oh hi LND! Empty commitment at #%"PRIu64,
peer->next_index[LOCAL]);
if (peer->last_empty_commitment == peer->next_index[LOCAL] - 1)
peer_failed(peer->pps,
&peer->channel_id,
"commit_sig with no changes (again!)");
peer->last_empty_commitment = peer->next_index[LOCAL];
}
/* We were supposed to check this was affordable as we go. */
if (peer->channel->funder == REMOTE) {
status_debug("Feerates are %u/%u",
peer->channel->view[LOCAL].feerate_per_kw,
peer->channel->view[REMOTE].feerate_per_kw);
assert(can_funder_afford_feerate(peer->channel,
peer->channel->view[LOCAL]
.feerate_per_kw));
}
if (!fromwire_commitment_signed(tmpctx, msg,
&channel_id, &commit_sig.s, &htlc_sigs))
peer_failed(peer->pps,
&peer->channel_id,
"Bad commit_sig %s", tal_hex(msg, msg));
/* SIGHASH_ALL is implied. */
commit_sig.sighash_type = SIGHASH_ALL;
txs =
channel_txs(tmpctx, peer->channel->chainparams, &htlc_map,
&wscripts, peer->channel, &peer->next_local_per_commit,
peer->next_index[LOCAL], LOCAL);
if (!derive_simple_key(&peer->channel->basepoints[REMOTE].htlc,
&peer->next_local_per_commit, &remote_htlckey))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Deriving remote_htlckey");
status_debug("Derived key %s from basepoint %s, point %s",
type_to_string(tmpctx, struct pubkey, &remote_htlckey),
type_to_string(tmpctx, struct pubkey,
&peer->channel->basepoints[REMOTE].htlc),
type_to_string(tmpctx, struct pubkey,
&peer->next_local_per_commit));
/* BOLT #2:
*
* A receiving node:
* - once all pending updates are applied:
* - if `signature` is not valid for its local commitment transaction:
* - MUST fail the channel.
*/
if (!check_tx_sig(txs[0], 0, NULL, wscripts[0],
&peer->channel->funding_pubkey[REMOTE], &commit_sig)) {
dump_htlcs(peer->channel, "receiving commit_sig");
peer_failed(peer->pps,
&peer->channel_id,
"Bad commit_sig signature %"PRIu64" %s for tx %s wscript %s key %s feerate %u",
peer->next_index[LOCAL],
type_to_string(msg, struct bitcoin_signature,
&commit_sig),
type_to_string(msg, struct bitcoin_tx, txs[0]),
tal_hex(msg, wscripts[0]),
type_to_string(msg, struct pubkey,
&peer->channel->funding_pubkey
[REMOTE]),
peer->channel->view[LOCAL].feerate_per_kw);
}
/* BOLT #2:
*
* A receiving node:
*...
* - if `num_htlcs` is not equal to the number of HTLC outputs in the
* local commitment transaction:
* - MUST fail the channel.
*/
if (tal_count(htlc_sigs) != tal_count(txs) - 1)
peer_failed(peer->pps,
&peer->channel_id,
"Expected %zu htlc sigs, not %zu",
tal_count(txs) - 1, tal_count(htlc_sigs));
/* BOLT #2:
*
* - if any `htlc_signature` is not valid for the corresponding HTLC
* transaction:
* - MUST fail the channel.
*/
for (i = 0; i < tal_count(htlc_sigs); i++) {
struct bitcoin_signature sig;
/* SIGHASH_ALL is implied. */
sig.s = htlc_sigs[i];
sig.sighash_type = SIGHASH_ALL;
if (!check_tx_sig(txs[1+i], 0, NULL, wscripts[1+i],
&remote_htlckey, &sig))
peer_failed(peer->pps,
&peer->channel_id,
"Bad commit_sig signature %s for htlc %s wscript %s key %s",
type_to_string(msg, struct bitcoin_signature, &sig),
type_to_string(msg, struct bitcoin_tx, txs[1+i]),
tal_hex(msg, wscripts[1+i]),
type_to_string(msg, struct pubkey,
&remote_htlckey));
}
status_debug("Received commit_sig with %zu htlc sigs",
tal_count(htlc_sigs));
/* Tell master daemon, then wait for ack. */
msg = got_commitsig_msg(NULL, peer->next_index[LOCAL],
channel_feerate(peer->channel, LOCAL),
&commit_sig, htlc_sigs, changed_htlcs, txs[0]);
master_wait_sync_reply(tmpctx, peer, take(msg),
WIRE_CHANNEL_GOT_COMMITSIG_REPLY);
return send_revocation(peer);
}
static u8 *got_revoke_msg(const tal_t *ctx, u64 revoke_num,
const struct secret *per_commitment_secret,
const struct pubkey *next_per_commit_point,
const struct htlc **changed_htlcs,
u32 feerate)
{
u8 *msg;
struct changed_htlc *changed = tal_arr(tmpctx, struct changed_htlc, 0);
for (size_t i = 0; i < tal_count(changed_htlcs); i++) {
struct changed_htlc c;
const struct htlc *htlc = changed_htlcs[i];
status_debug("HTLC %"PRIu64"[%s] => %s",
htlc->id, side_to_str(htlc_owner(htlc)),
htlc_state_name(htlc->state));
c.id = changed_htlcs[i]->id;
c.newstate = changed_htlcs[i]->state;
tal_arr_expand(&changed, c);
}
msg = towire_channel_got_revoke(ctx, revoke_num, per_commitment_secret,
next_per_commit_point, feerate, changed);
return msg;
}
static void handle_peer_revoke_and_ack(struct peer *peer, const u8 *msg)
{
struct secret old_commit_secret;
struct privkey privkey;
struct channel_id channel_id;
struct pubkey per_commit_point, next_per_commit;
const struct htlc **changed_htlcs = tal_arr(msg, const struct htlc *, 0);
if (!fromwire_revoke_and_ack(msg, &channel_id, &old_commit_secret,
&next_per_commit)) {
peer_failed(peer->pps,
&peer->channel_id,
"Bad revoke_and_ack %s", tal_hex(msg, msg));
}
if (peer->revocations_received != peer->next_index[REMOTE] - 2) {
peer_failed(peer->pps,
&peer->channel_id,
"Unexpected revoke_and_ack");
}
/* BOLT #2:
*
* A receiving node:
* - if `per_commitment_secret` does not generate the previous
* `per_commitment_point`:
* - MUST fail the channel.
*/
memcpy(&privkey, &old_commit_secret, sizeof(privkey));
if (!pubkey_from_privkey(&privkey, &per_commit_point)) {
peer_failed(peer->pps,
&peer->channel_id,
"Bad privkey %s",
type_to_string(msg, struct privkey, &privkey));
}
if (!pubkey_eq(&per_commit_point, &peer->old_remote_per_commit)) {
peer_failed(peer->pps,
&peer->channel_id,
"Wrong privkey %s for %"PRIu64" %s",
type_to_string(msg, struct privkey, &privkey),
peer->next_index[LOCAL]-2,
type_to_string(msg, struct pubkey,
&peer->old_remote_per_commit));
}
/* We start timer even if this returns false: we might have delayed
* commit because we were waiting for this! */
if (channel_rcvd_revoke_and_ack(peer->channel, &changed_htlcs))
status_debug("Commits outstanding after recv revoke_and_ack");
else
status_debug("No commits outstanding after recv revoke_and_ack");
/* Tell master about things this locks in, wait for response */
msg = got_revoke_msg(NULL, peer->revocations_received++,
&old_commit_secret, &next_per_commit,
changed_htlcs,
channel_feerate(peer->channel, LOCAL));
master_wait_sync_reply(tmpctx, peer, take(msg),
WIRE_CHANNEL_GOT_REVOKE_REPLY);
peer->old_remote_per_commit = peer->remote_per_commit;
peer->remote_per_commit = next_per_commit;
status_debug("revoke_and_ack %s: remote_per_commit = %s, old_remote_per_commit = %s",
side_to_str(peer->channel->funder),
type_to_string(tmpctx, struct pubkey,
&peer->remote_per_commit),
type_to_string(tmpctx, struct pubkey,
&peer->old_remote_per_commit));
start_commit_timer(peer);
}
static void handle_peer_fulfill_htlc(struct peer *peer, const u8 *msg)
{
struct channel_id channel_id;
u64 id;
struct preimage preimage;
enum channel_remove_err e;
struct htlc *h;
if (!fromwire_update_fulfill_htlc(msg, &channel_id,
&id, &preimage)) {
peer_failed(peer->pps,
&peer->channel_id,
"Bad update_fulfill_htlc %s", tal_hex(msg, msg));
}
e = channel_fulfill_htlc(peer->channel, LOCAL, id, &preimage, &h);
switch (e) {
case CHANNEL_ERR_REMOVE_OK:
/* FIXME: We could send preimages to master immediately. */
start_commit_timer(peer);
return;
/* These shouldn't happen, because any offered HTLC (which would give
* us the preimage) should have timed out long before. If we
* were to get preimages from other sources, this could happen. */
case CHANNEL_ERR_NO_SUCH_ID:
case CHANNEL_ERR_ALREADY_FULFILLED:
case CHANNEL_ERR_HTLC_UNCOMMITTED:
case CHANNEL_ERR_HTLC_NOT_IRREVOCABLE:
case CHANNEL_ERR_BAD_PREIMAGE:
peer_failed(peer->pps,
&peer->channel_id,
"Bad update_fulfill_htlc: failed to fulfill %"
PRIu64 " error %s", id, channel_remove_err_name(e));
}
abort();
}
static void handle_peer_fail_htlc(struct peer *peer, const u8 *msg)
{
struct channel_id channel_id;
u64 id;
enum channel_remove_err e;
u8 *reason;
struct htlc *htlc;
if (!fromwire_update_fail_htlc(msg, msg,
&channel_id, &id, &reason)) {
peer_failed(peer->pps,
&peer->channel_id,
"Bad update_fail_htlc %s", tal_hex(msg, msg));
}
e = channel_fail_htlc(peer->channel, LOCAL, id, &htlc);
switch (e) {
case CHANNEL_ERR_REMOVE_OK:
/* Save reason for when we tell master. */
htlc->fail = tal_steal(htlc, reason);
start_commit_timer(peer);
return;
case CHANNEL_ERR_NO_SUCH_ID:
case CHANNEL_ERR_ALREADY_FULFILLED:
case CHANNEL_ERR_HTLC_UNCOMMITTED:
case CHANNEL_ERR_HTLC_NOT_IRREVOCABLE:
case CHANNEL_ERR_BAD_PREIMAGE:
peer_failed(peer->pps,
&peer->channel_id,
"Bad update_fail_htlc: failed to remove %"
PRIu64 " error %s", id,
channel_remove_err_name(e));
}
abort();
}
static void handle_peer_fail_malformed_htlc(struct peer *peer, const u8 *msg)
{
struct channel_id channel_id;
u64 id;
enum channel_remove_err e;
struct sha256 sha256_of_onion, our_sha256_of_onion;
u16 failure_code;
struct htlc *htlc;
if (!fromwire_update_fail_malformed_htlc(msg, &channel_id, &id,
&sha256_of_onion,
&failure_code)) {
peer_failed(peer->pps,
&peer->channel_id,
"Bad update_fail_malformed_htlc %s",
tal_hex(msg, msg));
}
/* BOLT #2:
*
* - if the `BADONION` bit in `failure_code` is not set for
* `update_fail_malformed_htlc`:
* - MUST fail the channel.
*/
if (!(failure_code & BADONION)) {
peer_failed(peer->pps,
&peer->channel_id,
"Bad update_fail_malformed_htlc failure code %u",
failure_code);
}
/* BOLT #2:
*
* - if the `sha256_of_onion` in `update_fail_malformed_htlc`
* doesn't match the onion it sent:
* - MAY retry or choose an alternate error response.
*/
htlc = channel_get_htlc(peer->channel, LOCAL, id);
sha256(&our_sha256_of_onion, htlc->routing, tal_count(htlc->routing));
if (!sha256_eq(&sha256_of_onion, &our_sha256_of_onion))
status_unusual("update_fail_malformed_htlc for bad onion"
" for htlc with id %"PRIu64".", id);
/* We only handle these cases in make_failmsg, so convert any
* (future?) unknown one. */
if (failure_code != WIRE_INVALID_ONION_VERSION
&& failure_code != WIRE_INVALID_ONION_HMAC
&& failure_code != WIRE_INVALID_ONION_KEY) {
status_unusual("Unknown update_fail_malformed_htlc code %u:"
" sending temporary_channel_failure",
failure_code);
failure_code = WIRE_TEMPORARY_CHANNEL_FAILURE;
}
e = channel_fail_htlc(peer->channel, LOCAL, id, &htlc);
switch (e) {
case CHANNEL_ERR_REMOVE_OK:
/* This is the only case where we set failcode for a non-local
* failure; in a way, it is, since we have to report it. */
htlc->failcode = failure_code;
start_commit_timer(peer);
return;
case CHANNEL_ERR_NO_SUCH_ID:
case CHANNEL_ERR_ALREADY_FULFILLED:
case CHANNEL_ERR_HTLC_UNCOMMITTED:
case CHANNEL_ERR_HTLC_NOT_IRREVOCABLE:
case CHANNEL_ERR_BAD_PREIMAGE:
peer_failed(peer->pps,
&peer->channel_id,
"Bad update_fail_malformed_htlc: failed to remove %"
PRIu64 " error %s", id, channel_remove_err_name(e));
}
abort();
}
static void handle_peer_shutdown(struct peer *peer, const u8 *shutdown)
{
struct channel_id channel_id;
u8 *scriptpubkey;
/* Disable the channel. */
send_channel_update(peer, ROUTING_FLAGS_DISABLED);
if (!fromwire_shutdown(tmpctx, shutdown, &channel_id, &scriptpubkey))
peer_failed(peer->pps,
&peer->channel_id,
"Bad shutdown %s", tal_hex(peer, shutdown));
/* BOLT #2:
*
* - if both nodes advertised the `option_upfront_shutdown_script`
* feature, and the receiving node received a non-zero-length
* `shutdown_scriptpubkey` in `open_channel` or `accept_channel`, and
* that `shutdown_scriptpubkey` is not equal to `scriptpubkey`:
* - MUST fail the connection.
*/
/* openingd only sets this if feature was negotiated at opening. */
if (tal_count(peer->remote_upfront_shutdown_script)
&& !memeq(scriptpubkey, tal_count(scriptpubkey),
peer->remote_upfront_shutdown_script,
tal_count(peer->remote_upfront_shutdown_script)))
peer_failed(peer->pps,
&peer->channel_id,
"scriptpubkey %s is not as agreed upfront (%s)",
tal_hex(peer, scriptpubkey),
tal_hex(peer, peer->remote_upfront_shutdown_script));
/* Tell master: we don't have to wait because on reconnect other end
* will re-send anyway. */
wire_sync_write(MASTER_FD,
take(towire_channel_got_shutdown(NULL, scriptpubkey)));
peer->shutdown_sent[REMOTE] = true;
/* BOLT #2:
*
* A receiving node:
* ...
* - once there are no outstanding updates on the peer, UNLESS
* it has already sent a `shutdown`:
* - MUST reply to a `shutdown` message with a `shutdown`
*/
if (!peer->shutdown_sent[LOCAL]) {
peer->send_shutdown = true;
start_commit_timer(peer);
}
billboard_update(peer);
}
static void peer_in(struct peer *peer, const u8 *msg)
{
enum wire_type type = fromwire_peektype(msg);
peer->last_recv = time_now();
/* Catch our own ping replies. */
if (type == WIRE_PONG && peer->expecting_pong) {
peer->expecting_pong = false;
return;
}
if (handle_peer_gossip_or_error(peer->pps, &peer->channel_id, msg))
return;
/* Must get funding_locked before almost anything. */
if (!peer->funding_locked[REMOTE]) {
if (type != WIRE_FUNDING_LOCKED
&& type != WIRE_PONG
&& type != WIRE_SHUTDOWN
/* lnd sends these early; it's harmless. */
&& type != WIRE_UPDATE_FEE
&& type != WIRE_ANNOUNCEMENT_SIGNATURES) {
peer_failed(peer->pps,
&peer->channel_id,
"%s (%u) before funding locked",
wire_type_name(type), type);
}
}
switch (type) {
case WIRE_FUNDING_LOCKED:
handle_peer_funding_locked(peer, msg);
return;
case WIRE_ANNOUNCEMENT_SIGNATURES:
handle_peer_announcement_signatures(peer, msg);
return;
case WIRE_UPDATE_ADD_HTLC:
handle_peer_add_htlc(peer, msg);
return;
case WIRE_COMMITMENT_SIGNED:
handle_peer_commit_sig(peer, msg);
return;
case WIRE_UPDATE_FEE:
handle_peer_feechange(peer, msg);
return;
case WIRE_REVOKE_AND_ACK:
handle_peer_revoke_and_ack(peer, msg);
return;
case WIRE_UPDATE_FULFILL_HTLC:
handle_peer_fulfill_htlc(peer, msg);
return;
case WIRE_UPDATE_FAIL_HTLC:
handle_peer_fail_htlc(peer, msg);
return;
case WIRE_UPDATE_FAIL_MALFORMED_HTLC:
handle_peer_fail_malformed_htlc(peer, msg);
return;
case WIRE_SHUTDOWN:
handle_peer_shutdown(peer, msg);
return;
case WIRE_INIT:
case WIRE_OPEN_CHANNEL:
case WIRE_ACCEPT_CHANNEL:
case WIRE_FUNDING_CREATED:
case WIRE_FUNDING_SIGNED:
case WIRE_CHANNEL_REESTABLISH:
case WIRE_CLOSING_SIGNED:
break;
/* These are all swallowed by handle_peer_gossip_or_error */
case WIRE_CHANNEL_ANNOUNCEMENT:
case WIRE_CHANNEL_UPDATE:
case WIRE_NODE_ANNOUNCEMENT:
case WIRE_QUERY_SHORT_CHANNEL_IDS:
case WIRE_QUERY_CHANNEL_RANGE:
case WIRE_REPLY_CHANNEL_RANGE:
case WIRE_GOSSIP_TIMESTAMP_FILTER:
case WIRE_REPLY_SHORT_CHANNEL_IDS_END:
case WIRE_PING:
case WIRE_PONG:
case WIRE_ERROR:
abort();
}
peer_failed(peer->pps,
&peer->channel_id,
"Peer sent unknown message %u (%s)",
type, wire_type_name(type));
}
static void resend_revoke(struct peer *peer)
{
struct pubkey point;
/* Current commit is peer->next_index[LOCAL]-1, revoke prior */
u8 *msg = make_revocation_msg(peer, peer->next_index[LOCAL]-2, &point);
sync_crypto_write(peer->pps, take(msg));
}
static void send_fail_or_fulfill(struct peer *peer, const struct htlc *h)
{
u8 *msg;
/* Note that if h->shared_secret is NULL, it means that we knew
* this HTLC was invalid, but we still needed to hand it to lightningd
* for the db, etc. So in that case, we use our own saved failcode.
*
* This also lets us distinguish between "we can't decode onion" and
* "next hop said it can't decode onion". That second case is the
* only case where we use a failcode for a non-local error. */
/* Malformed: use special reply since we can't onion. */
if (!h->shared_secret) {
struct sha256 sha256_of_onion;
sha256(&sha256_of_onion, h->routing, tal_count(h->routing));
msg = towire_update_fail_malformed_htlc(NULL, &peer->channel_id,
h->id, &sha256_of_onion,
h->why_bad_onion);
} else if (h->failcode || h->fail) {
const u8 *onion;
if (h->failcode) {
/* Local failure, make a message. */
u8 *failmsg = make_failmsg(tmpctx, peer, h, h->failcode,
h->failed_scid,
&h->next_onion_sha,
h->failblock);
onion = create_onionreply(tmpctx, h->shared_secret,
failmsg);
} else /* Remote failure, just forward. */
onion = h->fail;
/* Now we wrap, just before sending out. */
msg = towire_update_fail_htlc(peer, &peer->channel_id, h->id,
wrap_onionreply(tmpctx,
h->shared_secret,
onion));
} else if (h->r) {
msg = towire_update_fulfill_htlc(NULL, &peer->channel_id, h->id,
h->r);
} else
peer_failed(peer->pps,
&peer->channel_id,
"HTLC %"PRIu64" state %s not failed/fulfilled",
h->id, htlc_state_name(h->state));
sync_crypto_write(peer->pps, take(msg));
}
static void resend_commitment(struct peer *peer, const struct changed_htlc *last)
{
size_t i;
struct bitcoin_signature commit_sig;
secp256k1_ecdsa_signature *htlc_sigs;
u8 *msg;
status_debug("Retransmitting commitment, feerate LOCAL=%u REMOTE=%u",
channel_feerate(peer->channel, LOCAL),
channel_feerate(peer->channel, REMOTE));
/* BOLT #2:
*
* - if `next_commitment_number` is equal to the commitment
* number of the last `commitment_signed` message the receiving node
* has sent:
* - MUST reuse the same commitment number for its next
* `commitment_signed`.
*/
/* In our case, we consider ourselves already committed to this, so
* retransmission is simplest. */
for (i = 0; i < tal_count(last); i++) {
const struct htlc *h;
h = channel_get_htlc(peer->channel,
htlc_state_owner(last[i].newstate),
last[i].id);
/* I think this can happen if we actually received revoke_and_ack
* then they asked for a retransmit */
if (!h)
peer_failed(peer->pps,
&peer->channel_id,
"Can't find HTLC %"PRIu64" to resend",
last[i].id);
if (h->state == SENT_ADD_COMMIT) {
u8 *msg = towire_update_add_htlc(NULL, &peer->channel_id,
h->id, h->amount,
&h->rhash,
abs_locktime_to_blocks(
&h->expiry),
h->routing);
sync_crypto_write(peer->pps, take(msg));
} else if (h->state == SENT_REMOVE_COMMIT) {
send_fail_or_fulfill(peer, h);
}
}
/* Make sure they have the correct fee. */
if (peer->channel->funder == LOCAL) {
msg = towire_update_fee(NULL, &peer->channel_id,
channel_feerate(peer->channel, REMOTE));
sync_crypto_write(peer->pps, take(msg));
}
/* Re-send the commitment_signed itself. */
htlc_sigs = calc_commitsigs(tmpctx, peer, peer->next_index[REMOTE]-1,
&commit_sig);
msg = towire_commitment_signed(NULL, &peer->channel_id,
&commit_sig.s, htlc_sigs);
sync_crypto_write(peer->pps, take(msg));
/* If we have already received the revocation for the previous, the
* other side shouldn't be asking for a retransmit! */
if (peer->revocations_received != peer->next_index[REMOTE] - 2)
status_unusual("Retransmitted commitment_signed %"PRIu64
" but they already send revocation %"PRIu64"?",
peer->next_index[REMOTE]-1,
peer->revocations_received);
}
/* BOLT #2:
*
* A receiving node:
* - if `option_static_remotekey` applies to the commitment transaction:
* - if `next_revocation_number` is greater than expected above, AND
* `your_last_per_commitment_secret` is correct for that
* `next_revocation_number` minus 1:
*...
* - otherwise, if it supports `option_data_loss_protect`, AND the
* `option_data_loss_protect` fields are present:
* - if `next_revocation_number` is greater than expected above,
* AND `your_last_per_commitment_secret` is correct for that
* `next_revocation_number` minus 1:
*/
static void check_future_dataloss_fields(struct peer *peer,
u64 next_revocation_number,
const struct secret *last_local_per_commit_secret,
/* This is NULL if option_static_remotekey */
const struct pubkey *remote_current_per_commitment_point)
{
const u8 *msg;
bool correct;
assert(next_revocation_number > peer->next_index[LOCAL] - 1);
msg = towire_hsm_check_future_secret(NULL,
next_revocation_number - 1,
last_local_per_commit_secret);
msg = hsm_req(tmpctx, take(msg));
if (!fromwire_hsm_check_future_secret_reply(msg, &correct))
status_failed(STATUS_FAIL_HSM_IO,
"Bad hsm_check_future_secret_reply: %s",
tal_hex(tmpctx, msg));
if (!correct)
peer_failed(peer->pps,
&peer->channel_id,
"bad future last_local_per_commit_secret: %"PRIu64
" vs %"PRIu64,
next_revocation_number,
peer->next_index[LOCAL] - 1);
/* Oh shit, they really are from the future! */
peer_billboard(true, "They have future commitment number %"PRIu64
" vs our %"PRIu64". We must wait for them to close!",
next_revocation_number,
peer->next_index[LOCAL] - 1);
/* BOLT #2:
* - MUST NOT broadcast its commitment transaction.
* - SHOULD fail the channel.
* - SHOULD store `my_current_per_commitment_point` to
* retrieve funds should the sending node broadcast its
* commitment transaction on-chain.
*/
wire_sync_write(MASTER_FD,
take(towire_channel_fail_fallen_behind(NULL,
remote_current_per_commitment_point)));
/* We have to send them an error to trigger dropping to chain. */
peer_failed(peer->pps, &peer->channel_id, "Awaiting unilateral close");
}
/* BOLT #2:
*
* A receiving node:
* - if `option_static_remotekey` applies to the commitment transaction:
* ...
* - if `your_last_per_commitment_secret` does not match the expected values:
* - SHOULD fail the channel.
* - otherwise, if it supports `option_data_loss_protect`, AND the
* `option_data_loss_protect` fields are present:
*...
* - otherwise (`your_last_per_commitment_secret` or
* `my_current_per_commitment_point` do not match the expected values):
* - SHOULD fail the channel.
*/
static void check_current_dataloss_fields(struct peer *peer,
u64 next_revocation_number,
u64 next_commitment_number,
const struct secret *last_local_per_commit_secret,
/* NULL if option_static_remotekey */
const struct pubkey *remote_current_per_commitment_point)
{
struct secret old_commit_secret;
/* By the time we're called, we've ensured this is a valid revocation
* number. */
assert(next_revocation_number == peer->next_index[LOCAL] - 2
|| next_revocation_number == peer->next_index[LOCAL] - 1);
/* By the time we're called, we've ensured we're within 1 of
* their commitment chain */
assert(next_commitment_number == peer->next_index[REMOTE] ||
next_commitment_number == peer->next_index[REMOTE] - 1);
if (!last_local_per_commit_secret)
return;
/* BOLT #2:
* - if `next_revocation_number` equals 0:
* - MUST set `your_last_per_commitment_secret` to all zeroes
*/
status_debug("next_revocation_number = %"PRIu64,
next_revocation_number);
if (next_revocation_number == 0)
memset(&old_commit_secret, 0, sizeof(old_commit_secret));
else {
struct pubkey unused;
/* This gets previous revocation number, since asking for
* commitment point N gives secret for N-2 */
get_per_commitment_point(next_revocation_number+1,
&unused, &old_commit_secret);
}
if (!secret_eq_consttime(&old_commit_secret,
last_local_per_commit_secret))
peer_failed(peer->pps,
&peer->channel_id,
"bad reestablish: your_last_per_commitment_secret %"PRIu64
": %s should be %s",
next_revocation_number,
type_to_string(tmpctx, struct secret,
last_local_per_commit_secret),
type_to_string(tmpctx, struct secret,
&old_commit_secret));
if (!remote_current_per_commitment_point) {
status_debug("option_static_remotekey: fields are correct");
return;
}
status_debug("Reestablish, comparing commitments. Remote's next local commitment number"
" is %"PRIu64". Our next remote is %"PRIu64" with %"PRIu64
" revocations received",
next_commitment_number,
peer->next_index[REMOTE],
peer->revocations_received);
/* Either they haven't received our commitment yet, or we're up to date */
if (next_commitment_number == peer->revocations_received + 1) {
if (!pubkey_eq(remote_current_per_commitment_point,
&peer->old_remote_per_commit)) {
peer_failed(peer->pps,
&peer->channel_id,
"bad reestablish: remote's "
"my_current_per_commitment_point %"PRIu64
"is %s; expected %s (new is %s).",
next_commitment_number - 1,
type_to_string(tmpctx, struct pubkey,
remote_current_per_commitment_point),
type_to_string(tmpctx, struct pubkey,
&peer->old_remote_per_commit),
type_to_string(tmpctx, struct pubkey,
&peer->remote_per_commit));
}
} else {
/* We've sent a commit sig but haven't gotten a revoke+ack back */
if (!pubkey_eq(remote_current_per_commitment_point,
&peer->remote_per_commit)) {
peer_failed(peer->pps,
&peer->channel_id,
"bad reestablish: remote's "
"my_current_per_commitment_point %"PRIu64
"is %s; expected %s (old is %s).",
next_commitment_number - 1,
type_to_string(tmpctx, struct pubkey,
remote_current_per_commitment_point),
type_to_string(tmpctx, struct pubkey,
&peer->remote_per_commit),
type_to_string(tmpctx, struct pubkey,
&peer->old_remote_per_commit));
}
}
status_debug("option_data_loss_protect: fields are correct");
}
/* Older LND sometimes sends funding_locked before reestablish! */
/* ... or announcement_signatures. Sigh, let's handle whatever they send. */
static bool capture_premature_msg(const u8 ***shit_lnd_says, const u8 *msg)
{
if (fromwire_peektype(msg) == WIRE_CHANNEL_REESTABLISH)
return false;
/* Don't allow infinite memory consumption. */
if (tal_count(*shit_lnd_says) > 10)
return false;
status_debug("Stashing early %s msg!",
wire_type_name(fromwire_peektype(msg)));
tal_arr_expand(shit_lnd_says, tal_steal(*shit_lnd_says, msg));
return true;
}
static void peer_reconnect(struct peer *peer,
const struct secret *last_remote_per_commit_secret)
{
struct channel_id channel_id;
/* Note: BOLT #2 uses these names! */
u64 next_commitment_number, next_revocation_number;
bool retransmit_revoke_and_ack, retransmit_commitment_signed;
struct htlc_map_iter it;
const struct htlc *htlc;
u8 *msg;
struct pubkey my_current_per_commitment_point,
remote_current_per_commitment_point;
struct secret last_local_per_commitment_secret;
bool dataloss_protect, check_extra_fields;
const u8 **premature_msgs = tal_arr(peer, const u8 *, 0);
dataloss_protect = local_feature_negotiated(peer->localfeatures,
LOCAL_DATA_LOSS_PROTECT);
/* Both these options give us extra fields to check. */
check_extra_fields
= dataloss_protect || peer->channel->option_static_remotekey;
/* Our current per-commitment point is the commitment point in the last
* received signed commitment */
get_per_commitment_point(peer->next_index[LOCAL] - 1,
&my_current_per_commitment_point, NULL);
/* BOLT #2:
*
* - upon reconnection:
* - if a channel is in an error state:
* - SHOULD retransmit the error packet and ignore any other packets for
* that channel.
* - otherwise:
* - MUST transmit `channel_reestablish` for each channel.
* - MUST wait to receive the other node's `channel_reestablish`
* message before sending any other messages for that channel.
*
* The sending node:
* - MUST set `next_commitment_number` to the commitment number
* of the next `commitment_signed` it expects to receive.
* - MUST set `next_revocation_number` to the commitment number
* of the next `revoke_and_ack` message it expects to receive.
* - if `option_static_remotekey` applies to the commitment transaction:
* - MUST set `my_current_per_commitment_point` to a valid point.
* - otherwise, if it supports `option_data_loss_protect`:
* - MUST set `my_current_per_commitment_point` to its commitment
* point for the last signed commitment it received from its
* channel peer (i.e. the commitment_point corresponding to the
* commitment transaction the sender would use to unilaterally
* close).
* - if `option_static_remotekey` applies to the commitment
* transaction, or the sending node supports
* `option_data_loss_protect`:
* - if `next_revocation_number` equals 0:
* - MUST set `your_last_per_commitment_secret` to all zeroes
* - otherwise:
* - MUST set `your_last_per_commitment_secret` to the last
* `per_commitment_secret` it received
*/
if (peer->channel->option_static_remotekey) {
msg = towire_channel_reestablish_option_static_remotekey
(NULL, &peer->channel_id,
peer->next_index[LOCAL],
peer->revocations_received,
last_remote_per_commit_secret,
/* Can send any (valid) point here */
&peer->remote_per_commit);
} else if (dataloss_protect) {
msg = towire_channel_reestablish_option_data_loss_protect
(NULL, &peer->channel_id,
peer->next_index[LOCAL],
peer->revocations_received,
last_remote_per_commit_secret,
&my_current_per_commitment_point);
} else {
msg = towire_channel_reestablish
(NULL, &peer->channel_id,
peer->next_index[LOCAL],
peer->revocations_received);
}
sync_crypto_write(peer->pps, take(msg));
peer_billboard(false, "Sent reestablish, waiting for theirs");
/* Read until they say something interesting (don't forward
* gossip *to* them yet: we might try sending channel_update
* before we've reestablished channel). */
do {
clean_tmpctx();
msg = sync_crypto_read(tmpctx, peer->pps);
} while (handle_peer_gossip_or_error(peer->pps, &peer->channel_id, msg)
|| capture_premature_msg(&premature_msgs, msg));
if (peer->channel->option_static_remotekey) {
struct pubkey ignore;
if (!fromwire_channel_reestablish_option_static_remotekey(msg,
&channel_id,
&next_commitment_number,
&next_revocation_number,
&last_local_per_commitment_secret,
&ignore)) {
peer_failed(peer->pps,
&peer->channel_id,
"bad reestablish static_remotekey msg: %s %s",
wire_type_name(fromwire_peektype(msg)),
tal_hex(msg, msg));
}
} else if (dataloss_protect) {
if (!fromwire_channel_reestablish_option_data_loss_protect(msg,
&channel_id,
&next_commitment_number,
&next_revocation_number,
&last_local_per_commitment_secret,
&remote_current_per_commitment_point)) {
peer_failed(peer->pps,
&peer->channel_id,
"bad reestablish dataloss msg: %s %s",
wire_type_name(fromwire_peektype(msg)),
tal_hex(msg, msg));
}
} else {
if (!fromwire_channel_reestablish(msg, &channel_id,
&next_commitment_number,
&next_revocation_number)) {
peer_failed(peer->pps,
&peer->channel_id,
"bad reestablish msg: %s %s",
wire_type_name(fromwire_peektype(msg)),
tal_hex(msg, msg));
}
}
status_debug("Got reestablish commit=%"PRIu64" revoke=%"PRIu64,
next_commitment_number,
next_revocation_number);
/* BOLT #2:
*
* - if `next_commitment_number` is 1 in both the
* `channel_reestablish` it sent and received:
* - MUST retransmit `funding_locked`.
* - otherwise:
* - MUST NOT retransmit `funding_locked`.
*/
if (peer->funding_locked[LOCAL]
&& peer->next_index[LOCAL] == 1
&& next_commitment_number == 1) {
u8 *msg;
status_debug("Retransmitting funding_locked for channel %s",
type_to_string(tmpctx, struct channel_id, &peer->channel_id));
/* Contains per commit point #1, for first post-opening commit */
msg = towire_funding_locked(NULL,
&peer->channel_id,
&peer->next_local_per_commit);
sync_crypto_write(peer->pps, take(msg));
}
/* Note: next_index is the index of the current commit we're working
* on, but BOLT #2 refers to the *last* commit index, so we -1 where
* required. */
/* BOLT #2:
*
* - if `next_revocation_number` is equal to the commitment
* number of the last `revoke_and_ack` the receiving node sent, AND
* the receiving node hasn't already received a `closing_signed`:
* - MUST re-send the `revoke_and_ack`.
* - otherwise:
* - if `next_revocation_number` is not equal to 1 greater
* than the commitment number of the last `revoke_and_ack` the
* receiving node has sent:
* - SHOULD fail the channel.
* - if it has not sent `revoke_and_ack`, AND
* `next_revocation_number` is not equal to 0:
* - SHOULD fail the channel.
*/
if (next_revocation_number == peer->next_index[LOCAL] - 2) {
/* Don't try to retransmit revocation index -1! */
if (peer->next_index[LOCAL] < 2) {
peer_failed(peer->pps,
&peer->channel_id,
"bad reestablish revocation_number: %"
PRIu64,
next_revocation_number);
}
retransmit_revoke_and_ack = true;
} else if (next_revocation_number < peer->next_index[LOCAL] - 1) {
peer_failed(peer->pps,
&peer->channel_id,
"bad reestablish revocation_number: %"PRIu64
" vs %"PRIu64,
next_revocation_number,
peer->next_index[LOCAL]);
} else if (next_revocation_number > peer->next_index[LOCAL] - 1) {
if (!check_extra_fields)
/* They don't support option_data_loss_protect or
* option_static_remotekey, we fail it due to
* unexpected number */
peer_failed(peer->pps,
&peer->channel_id,
"bad reestablish revocation_number: %"PRIu64
" vs %"PRIu64,
next_revocation_number,
peer->next_index[LOCAL] - 1);
/* Remote claims it's ahead of us: can it prove it?
* Does not return. */
check_future_dataloss_fields(peer,
next_revocation_number,
&last_local_per_commitment_secret,
peer->channel->option_static_remotekey ? NULL :
&remote_current_per_commitment_point);
} else
retransmit_revoke_and_ack = false;
/* BOLT #2:
*
* - if `next_commitment_number` is equal to the commitment
* number of the last `commitment_signed` message the receiving node
* has sent:
* - MUST reuse the same commitment number for its next
* `commitment_signed`.
*/
if (next_commitment_number == peer->next_index[REMOTE] - 1) {
/* We completed opening, we don't re-transmit that one! */
if (next_commitment_number == 0)
peer_failed(peer->pps,
&peer->channel_id,
"bad reestablish commitment_number: %"
PRIu64,
next_commitment_number);
retransmit_commitment_signed = true;
/* BOLT #2:
*
* - otherwise:
* - if `next_commitment_number` is not 1 greater than the
* commitment number of the last `commitment_signed` message the
* receiving node has sent:
* - SHOULD fail the channel.
*/
} else if (next_commitment_number != peer->next_index[REMOTE])
peer_failed(peer->pps,
&peer->channel_id,
"bad reestablish commitment_number: %"PRIu64
" vs %"PRIu64,
next_commitment_number,
peer->next_index[REMOTE]);
else
retransmit_commitment_signed = false;
/* After we checked basic sanity, we check dataloss fields if any */
if (check_extra_fields)
check_current_dataloss_fields(peer,
next_revocation_number,
next_commitment_number,
&last_local_per_commitment_secret,
peer->channel->option_static_remotekey
? NULL
: &remote_current_per_commitment_point);
/* We have to re-send in the same order we sent originally:
* revoke_and_ack (usually) alters our next commitment. */
if (retransmit_revoke_and_ack && !peer->last_was_revoke)
resend_revoke(peer);
if (retransmit_commitment_signed)
resend_commitment(peer, peer->last_sent_commit);
/* This covers the case where we sent revoke after commit. */
if (retransmit_revoke_and_ack && peer->last_was_revoke)
resend_revoke(peer);
/* BOLT #2:
*
* - upon reconnection:
* - if it has sent a previous `shutdown`:
* - MUST retransmit `shutdown`.
*/
/* (If we had sent `closing_signed`, we'd be in closingd). */
maybe_send_shutdown(peer);
/* Corner case: we didn't send shutdown before because update_add_htlc
* pending, but now they're cleared by restart, and we're actually
* complete. In that case, their `shutdown` will trigger us. */
/* Start commit timer: if we sent revoke we might need it. */
start_commit_timer(peer);
/* Now, re-send any that we're supposed to be failing. */
for (htlc = htlc_map_first(peer->channel->htlcs, &it);
htlc;
htlc = htlc_map_next(peer->channel->htlcs, &it)) {
if (htlc->state == SENT_REMOVE_HTLC)
send_fail_or_fulfill(peer, htlc);
}
/* Corner case: we will get upset with them if they send
* commitment_signed with no changes. But it could be that we sent a
* feechange, they acked, and now they want to commit it; we can't
* even tell by seeing if fees are different (short of saving full fee
* state in database) since it could be a tiny feechange, or two
* feechanges which cancelled out. */
if (peer->channel->funder == LOCAL)
peer->channel->changes_pending[LOCAL] = true;
peer_billboard(true, "Reconnected, and reestablished.");
/* BOLT #2:
* - upon reconnection:
*...
* - MUST transmit `channel_reestablish` for each channel.
* - MUST wait to receive the other node's `channel_reestablish`
* message before sending any other messages for that channel.
*/
/* LND doesn't wait. */
for (size_t i = 0; i < tal_count(premature_msgs); i++)
peer_in(peer, premature_msgs[i]);
tal_free(premature_msgs);
}
/* ignores the funding_depth unless depth >= minimum_depth
* (except to update billboard, and set peer->depth_togo). */
static void handle_funding_depth(struct peer *peer, const u8 *msg)
{
u32 depth;
struct short_channel_id *scid;
if (!fromwire_channel_funding_depth(tmpctx,
msg,
&scid,
&depth))
master_badmsg(WIRE_CHANNEL_FUNDING_DEPTH, msg);
/* Too late, we're shutting down! */
if (peer->shutdown_sent[LOCAL])
return;
if (depth < peer->channel->minimum_depth) {
peer->depth_togo = peer->channel->minimum_depth - depth;
} else {
peer->depth_togo = 0;
assert(scid);
peer->short_channel_ids[LOCAL] = *scid;
if (!peer->funding_locked[LOCAL]) {
status_debug("funding_locked: sending commit index %"PRIu64": %s",
peer->next_index[LOCAL],
type_to_string(tmpctx, struct pubkey,
&peer->next_local_per_commit));
msg = towire_funding_locked(NULL,
&peer->channel_id,
&peer->next_local_per_commit);
sync_crypto_write(peer->pps, take(msg));
peer->funding_locked[LOCAL] = true;
}
peer->announce_depth_reached = (depth >= ANNOUNCE_MIN_DEPTH);
/* Send temporary or final announcements */
channel_announcement_negotiate(peer);
}
billboard_update(peer);
}
static void handle_offer_htlc(struct peer *peer, const u8 *inmsg)
{
u8 *msg;
u32 cltv_expiry;
struct amount_msat amount;
struct sha256 payment_hash;
u8 onion_routing_packet[TOTAL_PACKET_SIZE];
enum channel_add_err e;
enum onion_type failcode;
/* Subtle: must be tal object since we marshal using tal_bytelen() */
const char *failmsg;
struct amount_sat htlc_fee;
if (!peer->funding_locked[LOCAL] || !peer->funding_locked[REMOTE])
status_failed(STATUS_FAIL_MASTER_IO,
"funding not locked for offer_htlc");
if (!fromwire_channel_offer_htlc(inmsg, &amount,
&cltv_expiry, &payment_hash,
onion_routing_packet))
master_badmsg(WIRE_CHANNEL_OFFER_HTLC, inmsg);
e = channel_add_htlc(peer->channel, LOCAL, peer->htlc_id,
amount, cltv_expiry, &payment_hash,
onion_routing_packet, NULL, &htlc_fee);
status_debug("Adding HTLC %"PRIu64" amount=%s cltv=%u gave %s",
peer->htlc_id,
type_to_string(tmpctx, struct amount_msat, &amount),
cltv_expiry,
channel_add_err_name(e));
switch (e) {
case CHANNEL_ERR_ADD_OK:
/* Tell the peer. */
msg = towire_update_add_htlc(NULL, &peer->channel_id,
peer->htlc_id, amount,
&payment_hash, cltv_expiry,
onion_routing_packet);
sync_crypto_write(peer->pps, take(msg));
start_commit_timer(peer);
/* Tell the master. */
msg = towire_channel_offer_htlc_reply(NULL, peer->htlc_id,
0, NULL);
wire_sync_write(MASTER_FD, take(msg));
peer->htlc_id++;
return;
case CHANNEL_ERR_INVALID_EXPIRY:
failcode = WIRE_INCORRECT_CLTV_EXPIRY;
failmsg = tal_fmt(inmsg, "Invalid cltv_expiry %u", cltv_expiry);
goto failed;
case CHANNEL_ERR_DUPLICATE:
case CHANNEL_ERR_DUPLICATE_ID_DIFFERENT:
status_failed(STATUS_FAIL_MASTER_IO,
"Duplicate HTLC %"PRIu64, peer->htlc_id);
/* FIXME: Fuzz the boundaries a bit to avoid probing? */
case CHANNEL_ERR_MAX_HTLC_VALUE_EXCEEDED:
failcode = WIRE_TEMPORARY_CHANNEL_FAILURE;
failmsg = tal_fmt(inmsg, "Maximum value exceeded");
goto failed;
case CHANNEL_ERR_CHANNEL_CAPACITY_EXCEEDED:
failcode = WIRE_TEMPORARY_CHANNEL_FAILURE;
failmsg = tal_fmt(inmsg, "Capacity exceeded - HTLC fee: %s", fmt_amount_sat(inmsg, &htlc_fee));
goto failed;
case CHANNEL_ERR_HTLC_BELOW_MINIMUM:
failcode = WIRE_AMOUNT_BELOW_MINIMUM;
failmsg = tal_fmt(inmsg, "HTLC too small (%s minimum)",
type_to_string(tmpctx,
struct amount_msat,
&peer->channel->config[REMOTE].htlc_minimum));
goto failed;
case CHANNEL_ERR_TOO_MANY_HTLCS:
failcode = WIRE_TEMPORARY_CHANNEL_FAILURE;
failmsg = tal_fmt(inmsg, "Too many HTLCs");
goto failed;
}
/* Shouldn't return anything else! */
abort();
failed:
msg = towire_channel_offer_htlc_reply(NULL, 0, failcode, (u8*)failmsg);
wire_sync_write(MASTER_FD, take(msg));
}
static void handle_feerates(struct peer *peer, const u8 *inmsg)
{
u32 feerate;
if (!fromwire_channel_feerates(inmsg, &feerate,
&peer->feerate_min,
&peer->feerate_max))
master_badmsg(WIRE_CHANNEL_FEERATES, inmsg);
/* BOLT #2:
*
* The node _responsible_ for paying the Bitcoin fee:
* - SHOULD send `update_fee` to ensure the current fee rate is
* sufficient (by a significant margin) for timely processing of the
* commitment transaction.
*/
if (peer->channel->funder == LOCAL) {
peer->desired_feerate = feerate;
start_commit_timer(peer);
} else {
/* BOLT #2:
*
* The node _not responsible_ for paying the Bitcoin fee:
* - MUST NOT send `update_fee`.
*/
/* FIXME: We could drop to chain if fees are too low, but
* that's fraught too. */
}
}
static void handle_specific_feerates(struct peer *peer, const u8 *inmsg)
{
u32 base_old = peer->fee_base;
u32 per_satoshi_old = peer->fee_per_satoshi;
if (!fromwire_channel_specific_feerates(inmsg,
&peer->fee_base,
&peer->fee_per_satoshi))
master_badmsg(WIRE_CHANNEL_SPECIFIC_FEERATES, inmsg);
/* only send channel updates if values actually changed */
if (peer->fee_base != base_old || peer->fee_per_satoshi != per_satoshi_old)
send_channel_update(peer, 0);
}
static void handle_preimage(struct peer *peer, const u8 *inmsg)
{
struct fulfilled_htlc fulfilled_htlc;
struct htlc *h;
if (!fromwire_channel_fulfill_htlc(inmsg, &fulfilled_htlc))
master_badmsg(WIRE_CHANNEL_FULFILL_HTLC, inmsg);
switch (channel_fulfill_htlc(peer->channel, REMOTE,
fulfilled_htlc.id,
&fulfilled_htlc.payment_preimage,
&h)) {
case CHANNEL_ERR_REMOVE_OK:
send_fail_or_fulfill(peer, h);
start_commit_timer(peer);
return;
/* These shouldn't happen, because any offered HTLC (which would give
* us the preimage) should have timed out long before. If we
* were to get preimages from other sources, this could happen. */
case CHANNEL_ERR_NO_SUCH_ID:
case CHANNEL_ERR_ALREADY_FULFILLED:
case CHANNEL_ERR_HTLC_UNCOMMITTED:
case CHANNEL_ERR_HTLC_NOT_IRREVOCABLE:
case CHANNEL_ERR_BAD_PREIMAGE:
status_failed(STATUS_FAIL_MASTER_IO,
"HTLC %"PRIu64" preimage failed",
fulfilled_htlc.id);
}
abort();
}
static void handle_fail(struct peer *peer, const u8 *inmsg)
{
struct failed_htlc *failed_htlc;
enum channel_remove_err e;
struct htlc *h;
u32 failheight;
if (!fromwire_channel_fail_htlc(inmsg, inmsg, &failed_htlc, &failheight))
master_badmsg(WIRE_CHANNEL_FAIL_HTLC, inmsg);
e = channel_fail_htlc(peer->channel, REMOTE, failed_htlc->id, &h);
switch (e) {
case CHANNEL_ERR_REMOVE_OK:
h->failcode = failed_htlc->failcode;
h->fail = tal_steal(h, failed_htlc->failreason);
h->failed_scid = tal_steal(h, failed_htlc->scid);
h->failblock = failheight;
send_fail_or_fulfill(peer, h);
start_commit_timer(peer);
return;
case CHANNEL_ERR_NO_SUCH_ID:
case CHANNEL_ERR_ALREADY_FULFILLED:
case CHANNEL_ERR_HTLC_UNCOMMITTED:
case CHANNEL_ERR_HTLC_NOT_IRREVOCABLE:
case CHANNEL_ERR_BAD_PREIMAGE:
status_failed(STATUS_FAIL_MASTER_IO,
"HTLC %"PRIu64" removal failed: %s",
failed_htlc->id,
channel_remove_err_name(e));
}
abort();
}
static void handle_shutdown_cmd(struct peer *peer, const u8 *inmsg)
{
if (!fromwire_channel_send_shutdown(inmsg))
master_badmsg(WIRE_CHANNEL_SEND_SHUTDOWN, inmsg);
/* We can't send this until commit (if any) is done, so start timer. */
peer->send_shutdown = true;
start_commit_timer(peer);
}
static void handle_send_error(struct peer *peer, const u8 *msg)
{
char *reason;
if (!fromwire_channel_send_error(msg, msg, &reason))
master_badmsg(WIRE_CHANNEL_SEND_ERROR, msg);
status_debug("Send error reason: %s", reason);
sync_crypto_write(peer->pps,
take(towire_errorfmt(NULL, &peer->channel_id,
"%s", reason)));
wire_sync_write(MASTER_FD,
take(towire_channel_send_error_reply(NULL)));
}
#if DEVELOPER
static void handle_dev_reenable_commit(struct peer *peer)
{
dev_suppress_commit = false;
start_commit_timer(peer);
status_debug("dev_reenable_commit");
wire_sync_write(MASTER_FD,
take(towire_channel_dev_reenable_commit_reply(NULL)));
}
static void handle_dev_memleak(struct peer *peer, const u8 *msg)
{
struct htable *memtable;
bool found_leak;
memtable = memleak_enter_allocations(tmpctx, msg, msg);
/* Now delete peer and things it has pointers to. */
memleak_remove_referenced(memtable, peer);
found_leak = dump_memleak(memtable);
wire_sync_write(MASTER_FD,
take(towire_channel_dev_memleak_reply(NULL,
found_leak)));
}
#endif /* DEVELOPER */
static void req_in(struct peer *peer, const u8 *msg)
{
enum channel_wire_type t = fromwire_peektype(msg);
switch (t) {
case WIRE_CHANNEL_FUNDING_DEPTH:
handle_funding_depth(peer, msg);
return;
case WIRE_CHANNEL_OFFER_HTLC:
handle_offer_htlc(peer, msg);
return;
case WIRE_CHANNEL_FEERATES:
handle_feerates(peer, msg);
return;
case WIRE_CHANNEL_FULFILL_HTLC:
handle_preimage(peer, msg);
return;
case WIRE_CHANNEL_FAIL_HTLC:
handle_fail(peer, msg);
return;
case WIRE_CHANNEL_SPECIFIC_FEERATES:
handle_specific_feerates(peer, msg);
return;
case WIRE_CHANNEL_SEND_SHUTDOWN:
handle_shutdown_cmd(peer, msg);
return;
case WIRE_CHANNEL_SEND_ERROR:
handle_send_error(peer, msg);
return;
#if DEVELOPER
case WIRE_CHANNEL_DEV_REENABLE_COMMIT:
handle_dev_reenable_commit(peer);
return;
case WIRE_CHANNEL_DEV_MEMLEAK:
handle_dev_memleak(peer, msg);
return;
#else
case WIRE_CHANNEL_DEV_REENABLE_COMMIT:
case WIRE_CHANNEL_DEV_MEMLEAK:
#endif /* DEVELOPER */
case WIRE_CHANNEL_INIT:
case WIRE_CHANNEL_OFFER_HTLC_REPLY:
case WIRE_CHANNEL_SENDING_COMMITSIG:
case WIRE_CHANNEL_GOT_COMMITSIG:
case WIRE_CHANNEL_GOT_REVOKE:
case WIRE_CHANNEL_SENDING_COMMITSIG_REPLY:
case WIRE_CHANNEL_GOT_COMMITSIG_REPLY:
case WIRE_CHANNEL_GOT_REVOKE_REPLY:
case WIRE_CHANNEL_GOT_FUNDING_LOCKED:
case WIRE_CHANNEL_GOT_ANNOUNCEMENT:
case WIRE_CHANNEL_GOT_SHUTDOWN:
case WIRE_CHANNEL_SHUTDOWN_COMPLETE:
case WIRE_CHANNEL_DEV_REENABLE_COMMIT_REPLY:
case WIRE_CHANNEL_FAIL_FALLEN_BEHIND:
case WIRE_CHANNEL_DEV_MEMLEAK_REPLY:
case WIRE_CHANNEL_SEND_ERROR_REPLY:
break;
}
master_badmsg(-1, msg);
}
static void init_shared_secrets(struct channel *channel,
const struct added_htlc *htlcs,
const enum htlc_state *hstates)
{
for (size_t i = 0; i < tal_count(htlcs); i++) {
struct htlc *htlc;
/* We only derive this for HTLCs *they* added. */
if (htlc_state_owner(hstates[i]) != REMOTE)
continue;
htlc = channel_get_htlc(channel, REMOTE, htlcs[i].id);
htlc->shared_secret = get_shared_secret(htlc, htlc,
&htlc->why_bad_onion,
&htlc->next_onion_sha);
}
}
/* We do this synchronously. */
static void init_channel(struct peer *peer)
{
struct basepoints points[NUM_SIDES];
struct amount_sat funding;
u16 funding_txout;
struct amount_msat local_msat;
struct pubkey funding_pubkey[NUM_SIDES];
struct channel_config conf[NUM_SIDES];
struct bitcoin_txid funding_txid;
enum side funder;
enum htlc_state *hstates;
struct fulfilled_htlc *fulfilled;
enum side *fulfilled_sides;
struct failed_htlc **failed;
enum side *failed_sides;
struct added_htlc *htlcs;
bool reconnected;
u8 *funding_signed;
const u8 *msg;
u32 feerate_per_kw[NUM_SIDES];
u32 minimum_depth, failheight;
struct secret last_remote_per_commit_secret;
secp256k1_ecdsa_signature *remote_ann_node_sig;
secp256k1_ecdsa_signature *remote_ann_bitcoin_sig;
bool option_static_remotekey;
assert(!(fcntl(MASTER_FD, F_GETFL) & O_NONBLOCK));
status_setup_sync(MASTER_FD);
msg = wire_sync_read(tmpctx, MASTER_FD);
if (!fromwire_channel_init(peer, msg,
&peer->chain_hash,
&funding_txid, &funding_txout,
&funding,
&minimum_depth,
&conf[LOCAL], &conf[REMOTE],
feerate_per_kw,
&peer->feerate_min, &peer->feerate_max,
&peer->their_commit_sig,
&peer->pps,
&funding_pubkey[REMOTE],
&points[REMOTE],
&peer->remote_per_commit,
&peer->old_remote_per_commit,
&funder,
&peer->fee_base,
&peer->fee_per_satoshi,
&local_msat,
&points[LOCAL],
&funding_pubkey[LOCAL],
&peer->node_ids[LOCAL],
&peer->node_ids[REMOTE],
&peer->commit_msec,
&peer->cltv_delta,
&peer->last_was_revoke,
&peer->last_sent_commit,
&peer->next_index[LOCAL],
&peer->next_index[REMOTE],
&peer->revocations_received,
&peer->htlc_id,
&htlcs,
&hstates,
&fulfilled,
&fulfilled_sides,
&failed,
&failed_sides,
&failheight,
&peer->funding_locked[LOCAL],
&peer->funding_locked[REMOTE],
&peer->short_channel_ids[LOCAL],
&reconnected,
&peer->send_shutdown,
&peer->shutdown_sent[REMOTE],
&peer->final_scriptpubkey,
&peer->channel_flags,
&funding_signed,
&peer->announce_depth_reached,
&last_remote_per_commit_secret,
&peer->localfeatures,
&peer->remote_upfront_shutdown_script,
&remote_ann_node_sig,
&remote_ann_bitcoin_sig,
&option_static_remotekey,
&dev_fast_gossip)) {
master_badmsg(WIRE_CHANNEL_INIT, msg);
}
/* stdin == requests, 3 == peer, 4 = gossip, 5 = gossip_store, 6 = HSM */
per_peer_state_set_fds(peer->pps, 3, 4, 5);
status_debug("init %s: remote_per_commit = %s, old_remote_per_commit = %s"
" next_idx_local = %"PRIu64
" next_idx_remote = %"PRIu64
" revocations_received = %"PRIu64
" feerates %u/%u (range %u-%u)",
side_to_str(funder),
type_to_string(tmpctx, struct pubkey,
&peer->remote_per_commit),
type_to_string(tmpctx, struct pubkey,
&peer->old_remote_per_commit),
peer->next_index[LOCAL], peer->next_index[REMOTE],
peer->revocations_received,
feerate_per_kw[LOCAL], feerate_per_kw[REMOTE],
peer->feerate_min, peer->feerate_max);
status_debug("option_static_remotekey = %u", option_static_remotekey);
if(remote_ann_node_sig && remote_ann_bitcoin_sig) {
peer->announcement_node_sigs[REMOTE] = *remote_ann_node_sig;
peer->announcement_bitcoin_sigs[REMOTE] = *remote_ann_bitcoin_sig;
peer->have_sigs[REMOTE] = true;
/* Before we store announcement into DB, we have made sure
* remote short_channel_id matched the local. Now we initial
* it directly!
*/
peer->short_channel_ids[REMOTE] = peer->short_channel_ids[LOCAL];
}
/* First commit is used for opening: if we've sent 0, we're on
* index 1. */
assert(peer->next_index[LOCAL] > 0);
assert(peer->next_index[REMOTE] > 0);
get_per_commitment_point(peer->next_index[LOCAL],
&peer->next_local_per_commit, NULL);
/* channel_id is set from funding txout */
derive_channel_id(&peer->channel_id, &funding_txid, funding_txout);
peer->channel = new_full_channel(peer,
&peer->chain_hash,
&funding_txid,
funding_txout,
minimum_depth,
funding,
local_msat,
feerate_per_kw,
&conf[LOCAL], &conf[REMOTE],
&points[LOCAL], &points[REMOTE],
&funding_pubkey[LOCAL],
&funding_pubkey[REMOTE],
option_static_remotekey,
funder);
if (!channel_force_htlcs(peer->channel, htlcs, hstates,
fulfilled, fulfilled_sides,
cast_const2(const struct failed_htlc **,
failed),
failed_sides, failheight))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Could not restore HTLCs");
/* We derive shared secrets for each remote HTLC, so we can
* create error packet if necessary. */
init_shared_secrets(peer->channel, htlcs, hstates);
/* We don't need these any more, so free them. */
tal_free(htlcs);
tal_free(hstates);
tal_free(fulfilled);
tal_free(fulfilled_sides);
tal_free(failed);
tal_free(failed_sides);
tal_free(remote_ann_node_sig);
tal_free(remote_ann_bitcoin_sig);
peer->channel_direction = node_id_idx(&peer->node_ids[LOCAL],
&peer->node_ids[REMOTE]);
/* Default desired feerate is the feerate we set for them last. */
if (peer->channel->funder == LOCAL)
peer->desired_feerate = feerate_per_kw[REMOTE];
/* from now we need keep watch over WIRE_CHANNEL_FUNDING_DEPTH */
peer->depth_togo = minimum_depth;
/* OK, now we can process peer messages. */
if (reconnected)
peer_reconnect(peer, &last_remote_per_commit_secret);
/* If we have a funding_signed message, send that immediately */
if (funding_signed)
sync_crypto_write(peer->pps, take(funding_signed));
/* Reenable channel */
channel_announcement_negotiate(peer);
billboard_update(peer);
}
static void send_shutdown_complete(struct peer *peer)
{
/* Now we can tell master shutdown is complete. */
wire_sync_write(MASTER_FD,
take(towire_channel_shutdown_complete(NULL, peer->pps)));
per_peer_state_fdpass_send(MASTER_FD, peer->pps);
close(MASTER_FD);
}
static void try_read_gossip_store(struct peer *peer)
{
u8 *msg = gossip_store_next(tmpctx, peer->pps);
if (msg)
sync_crypto_write(peer->pps, take(msg));
}
int main(int argc, char *argv[])
{
setup_locale();
int i, nfds;
fd_set fds_in, fds_out;
struct peer *peer;
subdaemon_setup(argc, argv);
peer = tal(NULL, struct peer);
peer->expecting_pong = false;
timers_init(&peer->timers, time_mono());
peer->commit_timer = NULL;
peer->have_sigs[LOCAL] = peer->have_sigs[REMOTE] = false;
peer->announce_depth_reached = false;
peer->channel_local_active = false;
peer->from_master = msg_queue_new(peer);
peer->shutdown_sent[LOCAL] = false;
peer->last_update_timestamp = 0;
/* We actually received it in the previous daemon, but near enough */
peer->last_recv = time_now();
peer->last_empty_commitment = 0;
/* We send these to HSM to get real signatures; don't have valgrind
* complain. */
for (i = 0; i < NUM_SIDES; i++) {
memset(&peer->announcement_node_sigs[i], 0,
sizeof(peer->announcement_node_sigs[i]));
memset(&peer->announcement_bitcoin_sigs[i], 0,
sizeof(peer->announcement_bitcoin_sigs[i]));
}
/* Read init_channel message sync. */
init_channel(peer);
FD_ZERO(&fds_in);
FD_SET(MASTER_FD, &fds_in);
FD_SET(peer->pps->peer_fd, &fds_in);
FD_SET(peer->pps->gossip_fd, &fds_in);
FD_ZERO(&fds_out);
FD_SET(peer->pps->peer_fd, &fds_out);
nfds = peer->pps->gossip_fd+1;
while (!shutdown_complete(peer)) {
struct timemono first;
fd_set rfds = fds_in;
struct timeval timeout, *tptr;
struct timer *expired;
const u8 *msg;
struct timerel trel;
struct timemono now = time_mono();
/* Free any temporary allocations */
clean_tmpctx();
/* For simplicity, we process one event at a time. */
msg = msg_dequeue(peer->from_master);
if (msg) {
status_debug("Now dealing with deferred %s",
channel_wire_type_name(
fromwire_peektype(msg)));
req_in(peer, msg);
tal_free(msg);
continue;
}
expired = timers_expire(&peer->timers, now);
if (expired) {
timer_expired(peer, expired);
continue;
}
if (timer_earliest(&peer->timers, &first)) {
timeout = timespec_to_timeval(
timemono_between(first, now).ts);
tptr = &timeout;
} else if (time_to_next_gossip(peer->pps, &trel)) {
timeout = timerel_to_timeval(trel);
tptr = &timeout;
} else
tptr = NULL;
if (select(nfds, &rfds, NULL, NULL, tptr) < 0) {
/* Signals OK, eg. SIGUSR1 */
if (errno == EINTR)
continue;
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"select failed: %s", strerror(errno));
}
if (FD_ISSET(MASTER_FD, &rfds)) {
msg = wire_sync_read(tmpctx, MASTER_FD);
if (!msg)
status_failed(STATUS_FAIL_MASTER_IO,
"Can't read command: %s",
strerror(errno));
req_in(peer, msg);
} else if (FD_ISSET(peer->pps->peer_fd, &rfds)) {
/* This could take forever, but who cares? */
msg = sync_crypto_read(tmpctx, peer->pps);
peer_in(peer, msg);
} else if (FD_ISSET(peer->pps->gossip_fd, &rfds)) {
msg = wire_sync_read(tmpctx, peer->pps->gossip_fd);
/* Gossipd hangs up on us to kill us when a new
* connection comes in. */
if (!msg)
peer_failed_connection_lost();
handle_gossip_msg(peer->pps, take(msg));
} else /* Lowest priority: stream from store. */
try_read_gossip_store(peer);
}
/* We only exit when shutdown is complete. */
assert(shutdown_complete(peer));
send_shutdown_complete(peer);
daemon_shutdown();
return 0;
}