core-lightning/daemon/peer.c

3678 lines
103 KiB
C
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#include "bitcoind.h"
#include "chaintopology.h"
#include "close_tx.h"
#include "commit_tx.h"
#include "controlled_time.h"
#include "cryptopkt.h"
#include "dns.h"
#include "find_p2sh_out.h"
#include "jsonrpc.h"
#include "lightningd.h"
#include "log.h"
#include "names.h"
#include "onion.h"
#include "output_to_htlc.h"
#include "packets.h"
#include "pay.h"
#include "payment.h"
#include "peer.h"
#include "permute_tx.h"
#include "protobuf_convert.h"
#include "pseudorand.h"
#include "routing.h"
#include "secrets.h"
#include "state.h"
#include "timeout.h"
#include "utils.h"
#include "wallet.h"
#include <bitcoin/base58.h>
#include <bitcoin/script.h>
#include <bitcoin/tx.h>
#include <ccan/array_size/array_size.h>
#include <ccan/cast/cast.h>
#include <ccan/io/io.h>
#include <ccan/list/list.h>
#include <ccan/mem/mem.h>
#include <ccan/noerr/noerr.h>
#include <ccan/ptrint/ptrint.h>
#include <ccan/str/hex/hex.h>
#include <ccan/structeq/structeq.h>
#include <ccan/tal/str/str.h>
#include <ccan/tal/tal.h>
#include <errno.h>
#include <inttypes.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <sys/types.h>
struct json_connecting {
/* This owns us, so we're freed after command_fail or command_success */
struct command *cmd;
const char *name, *port;
struct anchor_input *input;
};
static bool command_htlc_fail(struct peer *peer, struct htlc *htlc);
static bool command_htlc_fulfill(struct peer *peer, struct htlc *htlc);
static void try_commit(struct peer *peer);
void peer_add_their_commit(struct peer *peer,
const struct sha256_double *txid, u64 commit_num)
{
struct their_commit *tc = tal(peer, struct their_commit);
tc->txid = *txid;
tc->commit_num = commit_num;
list_add_tail(&peer->their_commits, &tc->list);
}
/* Create a bitcoin close tx, using last signature they sent. */
static const struct bitcoin_tx *bitcoin_close(struct peer *peer)
{
struct bitcoin_tx *close_tx;
struct bitcoin_signature our_close_sig;
close_tx = peer_create_close_tx(peer, peer->closing.their_fee);
our_close_sig.stype = SIGHASH_ALL;
peer_sign_mutual_close(peer, close_tx, &our_close_sig.sig);
close_tx->input[0].witness
= bitcoin_witness_2of2(close_tx->input,
peer->dstate->secpctx,
peer->closing.their_sig,
&our_close_sig,
&peer->remote.commitkey,
&peer->local.commitkey);
return close_tx;
}
/* Create a bitcoin spend tx (to spend our commit's outputs) */
static const struct bitcoin_tx *bitcoin_spend_ours(struct peer *peer)
{
u8 *witnessscript;
const struct bitcoin_tx *commit = peer->local.commit->tx;
struct bitcoin_signature sig;
struct bitcoin_tx *tx;
unsigned int p2wsh_out;
uint64_t fee;
/* The redeemscript for a commit tx is fairly complex. */
witnessscript = bitcoin_redeem_secret_or_delay(peer,
peer->dstate->secpctx,
&peer->local.finalkey,
&peer->remote.locktime,
&peer->remote.finalkey,
&peer->local.commit->revocation_hash);
/* Now, create transaction to spend it. */
tx = bitcoin_tx(peer, 1, 1);
tx->input[0].txid = peer->local.commit->txid;
p2wsh_out = find_p2wsh_out(commit, witnessscript);
tx->input[0].index = p2wsh_out;
tx->input[0].sequence_number = bitcoin_nsequence(&peer->remote.locktime);
tx->input[0].amount = tal_dup(tx->input, u64,
&commit->output[p2wsh_out].amount);
tx->output[0].script = scriptpubkey_p2sh(tx,
bitcoin_redeem_single(tx,
peer->dstate->secpctx,
&peer->local.finalkey));
tx->output[0].script_length = tal_count(tx->output[0].script);
/* Witness length can vary, due to DER encoding of sigs, but we
* use 176 from an example run. */
assert(measure_tx_cost(tx) == 83 * 4);
/* FIXME: Dynamic fees! */
fee = fee_by_feerate(83 + 176 / 4,
peer->dstate->config.closing_fee_rate);
/* FIXME: Fail gracefully in these cases (not worth collecting) */
if (fee > commit->output[p2wsh_out].amount
|| is_dust_amount(commit->output[p2wsh_out].amount - fee))
fatal("Amount of %"PRIu64" won't cover fee %"PRIu64,
commit->output[p2wsh_out].amount, fee);
tx->output[0].amount = commit->output[p2wsh_out].amount - fee;
sig.stype = SIGHASH_ALL;
peer_sign_spend(peer, tx, witnessscript, &sig.sig);
tx->input[0].witness = bitcoin_witness_secret(tx,
peer->dstate->secpctx,
NULL, 0, &sig,
witnessscript);
return tx;
}
/* Sign and return our commit tx */
static const struct bitcoin_tx *bitcoin_commit(struct peer *peer)
{
struct bitcoin_signature sig;
/* Can't be signed already, and can't have scriptsig! */
assert(peer->local.commit->tx->input[0].script_length == 0);
assert(!peer->local.commit->tx->input[0].witness);
sig.stype = SIGHASH_ALL;
peer_sign_ourcommit(peer, peer->local.commit->tx, &sig.sig);
peer->local.commit->tx->input[0].witness
= bitcoin_witness_2of2(peer->local.commit->tx->input,
peer->dstate->secpctx,
peer->local.commit->sig,
&sig,
&peer->remote.commitkey,
&peer->local.commitkey);
return peer->local.commit->tx;
}
static u64 commit_tx_fee(const struct bitcoin_tx *commit, u64 anchor_satoshis)
{
uint64_t i, total = 0;
for (i = 0; i < commit->output_count; i++)
total += commit->output[i].amount;
assert(anchor_satoshis >= total);
return anchor_satoshis - total;
}
struct peer *find_peer(struct lightningd_state *dstate, const struct pubkey *id)
{
struct peer *peer;
list_for_each(&dstate->peers, peer, list) {
if (peer->id && pubkey_eq(peer->id, id))
return peer;
}
return NULL;
}
static struct peer *find_peer_json(struct lightningd_state *dstate,
const char *buffer,
jsmntok_t *peeridtok)
{
struct pubkey peerid;
if (!pubkey_from_hexstr(dstate->secpctx,
buffer + peeridtok->start,
peeridtok->end - peeridtok->start, &peerid))
return NULL;
return find_peer(dstate, &peerid);
}
static bool peer_uncommitted_changes(const struct peer *peer)
{
struct htlc_map_iter it;
struct htlc *h;
for (h = htlc_map_first(&peer->htlcs, &it);
h;
h = htlc_map_next(&peer->htlcs, &it)) {
if (htlc_has(h, HTLC_REMOTE_F_PENDING))
return true;
}
return false;
}
static void remote_changes_pending(struct peer *peer)
{
log_debug(peer->log, "remote_changes_pending: changes=%u",
peer->remote.staging_cstate->changes);
if (!peer->commit_timer) {
log_debug(peer->log, "remote_changes_pending: adding timer");
peer->commit_timer = new_reltimer(peer->dstate, peer,
peer->dstate->config.commit_time,
try_commit, peer);
} else
log_debug(peer->log, "remote_changes_pending: timer already exists");
}
static void peer_update_complete(struct peer *peer)
{
log_debug(peer->log, "peer_update_complete");
if (peer->commit_jsoncmd) {
command_success(peer->commit_jsoncmd,
null_response(peer->commit_jsoncmd));
peer->commit_jsoncmd = NULL;
}
/* Have we got more changes in the meantime? */
if (peer_uncommitted_changes(peer)) {
log_debug(peer->log, "peer_update_complete: more changes!");
remote_changes_pending(peer);
}
}
void peer_open_complete(struct peer *peer, const char *problem)
{
if (problem)
log_unusual(peer->log, "peer open failed: %s", problem);
else {
struct lightningd_state *dstate = peer->dstate;
struct node *n;
log_debug(peer->log, "peer open complete");
assert(!peer->nc);
n = get_node(dstate, peer->id);
if (!n)
n = new_node(dstate, peer->id);
peer->nc = add_connection(dstate,
get_node(dstate, &dstate->id), n,
dstate->config.fee_base,
dstate->config.fee_per_satoshi,
dstate->config.min_htlc_expiry,
dstate->config.min_htlc_expiry);
}
}
static void set_peer_state(struct peer *peer, enum state newstate,
const char *caller)
{
log_debug(peer->log, "%s: %s => %s", caller,
state_name(peer->state), state_name(newstate));
peer->state = newstate;
}
static void peer_breakdown(struct peer *peer)
{
if (peer->commit_jsoncmd) {
command_fail(peer->commit_jsoncmd, "peer breakdown");
peer->commit_jsoncmd = NULL;
}
/* If we have a closing tx, use it. */
if (peer->closing.their_sig) {
log_unusual(peer->log, "Peer breakdown: sending close tx");
broadcast_tx(peer, bitcoin_close(peer));
/* If we have a signed commit tx (maybe not if we just offered
* anchor, or they supplied anchor). */
} else if (peer->local.commit->sig) {
log_unusual(peer->log, "Peer breakdown: sending commit tx");
broadcast_tx(peer, bitcoin_commit(peer));
} else {
log_info(peer->log, "Peer breakdown: nothing to do");
/* We close immediately. */
set_peer_state(peer, STATE_CLOSED, __func__);
io_wake(peer);
}
}
/* All unrevoked commit txs must have no HTLCs in them. */
static bool committed_to_htlcs(const struct peer *peer)
{
struct htlc_map_iter it;
struct htlc *h;
for (h = htlc_map_first(&peer->htlcs, &it);
h;
h = htlc_map_next(&peer->htlcs, &it)) {
/* FIXME: Move these dead ones to a separate hash (or
* just leave in database only). */
if (h->state == RCVD_REMOVE_ACK_REVOCATION)
continue;
if (h->state == SENT_REMOVE_ACK_REVOCATION)
continue;
return true;
}
return false;
}
static struct io_plan *peer_close(struct io_conn *conn, struct peer *peer)
{
/* Tell writer to wrap it up (may have to xmit first) */
io_wake(peer);
/* We do nothing more. */
return io_wait(conn, NULL, io_never, NULL);
}
/* Communication failed: send err (if non-NULL), then dump to chain and close. */
static bool peer_comms_err(struct peer *peer, Pkt *err)
{
if (err)
queue_pkt_err(peer, err);
set_peer_state(peer, STATE_ERR_BREAKDOWN, __func__);
peer_breakdown(peer);
return false;
}
void peer_unexpected_pkt(struct peer *peer, const Pkt *pkt)
{
const char *p;
log_unusual(peer->log, "Received unexpected pkt %u (%s)",
pkt->pkt_case, pkt_name(pkt->pkt_case));
if (pkt->pkt_case != PKT__PKT_ERROR)
return;
/* Check packet for weird chars. */
for (p = pkt->error->problem; *p; p++) {
if (cisprint(*p))
continue;
p = tal_hexstr(peer, pkt->error->problem,
strlen(pkt->error->problem));
log_unusual(peer->log, "Error pkt (hex) %s", p);
tal_free(p);
return;
}
log_unusual(peer->log, "Error pkt '%s'", pkt->error->problem);
}
/* Unexpected packet received: stop listening, start breakdown procedure. */
static bool peer_received_unexpected_pkt(struct peer *peer, const Pkt *pkt)
{
peer_unexpected_pkt(peer, pkt);
return peer_comms_err(peer, pkt_err_unexpected(peer, pkt));
}
static void route_htlc_onwards(struct peer *peer,
struct htlc *htlc,
u64 msatoshis,
const BitcoinPubkey *pb_id,
const u8 *rest_of_route)
{
struct pubkey id;
struct peer *next;
log_debug_struct(peer->log, "Forwarding HTLC %s", struct sha256, &htlc->rhash);
log_add(peer->log, " (id %"PRIu64")", htlc->id);
if (!proto_to_pubkey(peer->dstate->secpctx, pb_id, &id)) {
log_unusual(peer->log,
"Malformed pubkey for HTLC %"PRIu64, htlc->id);
command_htlc_fail(peer, htlc);
return;
}
next = find_peer(peer->dstate, &id);
if (!next || !next->nc) {
log_unusual(peer->log, "Can't route HTLC %"PRIu64": no %speer ",
htlc->id, next ? "ready " : "");
log_add_struct(peer->log, "%s", struct pubkey, &id);
if (!peer->dstate->dev_never_routefail)
command_htlc_fail(peer, htlc);
return;
}
/* Offered fee must be sufficient. */
if (htlc->msatoshis - msatoshis < connection_fee(next->nc, msatoshis)) {
log_unusual(peer->log,
"Insufficient fee for HTLC %"PRIu64
": %"PRIi64" on %"PRIu64,
htlc->id, htlc->msatoshis - msatoshis,
msatoshis);
command_htlc_fail(peer, htlc);
return;
}
log_debug_struct(peer->log, "HTLC forward to %s",
struct pubkey, next->id);
/* This checks the HTLC itself is possible. */
if (!command_htlc_add(next, msatoshis,
abs_locktime_to_blocks(&htlc->expiry)
- next->nc->delay,
&htlc->rhash, htlc, rest_of_route)) {
command_htlc_fail(peer, htlc);
return;
}
}
static void their_htlc_added(struct peer *peer, struct htlc *htlc)
{
RouteStep *step;
const u8 *rest_of_route;
struct payment *payment;
if (abs_locktime_is_seconds(&htlc->expiry)) {
log_unusual(peer->log, "HTLC %"PRIu64" is in seconds", htlc->id);
command_htlc_fail(peer, htlc);
return;
}
if (abs_locktime_to_blocks(&htlc->expiry) <=
get_block_height(peer->dstate) + peer->dstate->config.min_htlc_expiry) {
log_unusual(peer->log, "HTLC %"PRIu64" expires too soon:"
" block %u",
htlc->id, abs_locktime_to_blocks(&htlc->expiry));
command_htlc_fail(peer, htlc);
return;
}
if (abs_locktime_to_blocks(&htlc->expiry) >
get_block_height(peer->dstate) + peer->dstate->config.max_htlc_expiry) {
log_unusual(peer->log, "HTLC %"PRIu64" expires too far:"
" block %u",
htlc->id, abs_locktime_to_blocks(&htlc->expiry));
command_htlc_fail(peer, htlc);
return;
}
step = onion_unwrap(peer, htlc->routing, tal_count(htlc->routing),
&rest_of_route);
if (!step) {
log_unusual(peer->log, "Bad onion, failing HTLC %"PRIu64,
htlc->id);
command_htlc_fail(peer, htlc);
return;
}
switch (step->next_case) {
case ROUTE_STEP__NEXT_END:
payment = find_payment(peer->dstate, &htlc->rhash);
if (!payment) {
log_unusual(peer->log, "No payment for HTLC %"PRIu64,
htlc->id);
log_add_struct(peer->log, " rhash=%s",
struct sha256, &htlc->rhash);
if (unlikely(!peer->dstate->dev_never_routefail))
command_htlc_fail(peer, htlc);
goto free_rest;
}
if (htlc->msatoshis != payment->msatoshis) {
log_unusual(peer->log, "Short payment for HTLC %"PRIu64
": %"PRIu64" not %"PRIu64 " satoshi!",
htlc->id,
htlc->msatoshis,
payment->msatoshis);
command_htlc_fail(peer, htlc);
return;
}
log_info(peer->log, "Immediately resolving HTLC %"PRIu64,
htlc->id);
assert(!htlc->r);
htlc->r = tal_dup(htlc, struct rval, &payment->r);
command_htlc_fulfill(peer, htlc);
goto free_rest;
case ROUTE_STEP__NEXT_BITCOIN:
route_htlc_onwards(peer, htlc, step->amount, step->bitcoin,
rest_of_route);
goto free_rest;
default:
log_info(peer->log, "Unknown step type %u", step->next_case);
command_htlc_fail(peer, htlc);
goto free_rest;
}
free_rest:
tal_free(rest_of_route);
}
static void our_htlc_failed(struct peer *peer, struct htlc *htlc)
{
if (htlc->src)
command_htlc_fail(htlc->src->peer, htlc->src);
else
complete_pay_command(peer, htlc);
}
static void our_htlc_fulfilled(struct peer *peer, struct htlc *htlc,
const struct rval *preimage)
{
if (htlc->src) {
assert(!htlc->src->r);
htlc->src->r = tal_dup(htlc->src, struct rval, htlc->r);
command_htlc_fulfill(htlc->src->peer, htlc->src);
} else {
complete_pay_command(peer, htlc);
}
}
static void adjust_cstate_side(struct channel_state *cstate,
struct htlc *h,
enum htlc_state old, enum htlc_state new,
enum htlc_side side)
{
int oldf = htlc_state_flags(old), newf = htlc_state_flags(new);
bool old_committed, new_committed;
/* We applied changes to staging_cstate when we first received
* add/remove packet, so we could make sure it was valid. Don't
* do that again. */
if (old == SENT_ADD_HTLC || old == RCVD_REMOVE_HTLC
|| old == RCVD_ADD_HTLC || old == SENT_REMOVE_HTLC)
return;
old_committed = (oldf & HTLC_FLAG(side, HTLC_F_COMMITTED));
new_committed = (newf & HTLC_FLAG(side, HTLC_F_COMMITTED));
if (old_committed && !new_committed) {
if (h->r)
cstate_fulfill_htlc(cstate, h, htlc_channel_side(h));
else
cstate_fail_htlc(cstate, h, htlc_channel_side(h));
} else if (!old_committed && new_committed) {
/* FIXME: This can happen; see BOLT */
if (!cstate_add_htlc(cstate, h, htlc_channel_side(h)))
fatal("Could not afford htlc");
}
}
/* We apply changes to staging_cstate when we first PENDING, so we can
* make sure they're valid. So here we change the staging_cstate on
* the revocation receive (ie. when acked). */
static void adjust_cstates(struct peer *peer, struct htlc *h,
enum htlc_state old, enum htlc_state new)
{
adjust_cstate_side(peer->remote.staging_cstate, h, old, new, REMOTE);
adjust_cstate_side(peer->local.staging_cstate, h, old, new, LOCAL);
}
static void check_both_committed(struct peer *peer, struct htlc *h)
{
if (!htlc_has(h, HTLC_ADDING) && !htlc_has(h, HTLC_REMOVING))
log_debug(peer->log,
"Both committed to %s of %s HTLC %"PRIu64 "(%s)",
h->state == SENT_ADD_ACK_REVOCATION
|| h->state == RCVD_ADD_ACK_REVOCATION ? "ADD"
: h->r ? "FULFILL" : "FAIL",
htlc_owner(h) == LOCAL ? "our" : "their",
h->id, htlc_state_name(h->state));
switch (h->state) {
case RCVD_REMOVE_ACK_REVOCATION:
/* If it was fulfilled, we handled it immediately. */
if (!h->r)
our_htlc_failed(peer, h);
break;
case RCVD_ADD_ACK_REVOCATION:
their_htlc_added(peer, h);
break;
default:
break;
}
}
struct state_table {
enum htlc_state from, to;
};
static bool htlcs_changestate(struct peer *peer,
const struct state_table *table, size_t n)
{
struct htlc_map_iter it;
struct htlc *h;
bool changed = false;
for (h = htlc_map_first(&peer->htlcs, &it);
h;
h = htlc_map_next(&peer->htlcs, &it)) {
size_t i;
for (i = 0; i < n; i++) {
if (h->state == table[i].from) {
adjust_cstates(peer, h,
table[i].from, table[i].to);
htlc_changestate(h, table[i].from, table[i].to);
check_both_committed(peer, h);
changed = true;
}
}
}
return changed;
}
/* This is the io loop while we're negotiating closing tx. */
static bool closing_pkt_in(struct peer *peer, const Pkt *pkt)
{
const CloseSignature *c = pkt->close_signature;
struct bitcoin_tx *close_tx;
struct bitcoin_signature theirsig;
assert(peer->state == STATE_MUTUAL_CLOSING);
if (pkt->pkt_case != PKT__PKT_CLOSE_SIGNATURE)
return peer_received_unexpected_pkt(peer, pkt);
log_info(peer->log, "closing_pkt_in: they offered close fee %"PRIu64,
c->close_fee);
/* BOLT #2:
*
* The sender MUST set `close_fee` lower than or equal to the fee of the
* final commitment transaction, and MUST set `close_fee` to an even
* number of satoshis.
*/
if ((c->close_fee & 1)
|| c->close_fee > commit_tx_fee(peer->remote.commit->tx,
peer->anchor.satoshis)) {
return peer_comms_err(peer, pkt_err(peer, "Invalid close fee"));
}
/* FIXME: Don't accept tiny fee at all? */
/* BOLT #2:
... otherwise it SHOULD propose a
value strictly between the received `close_fee` and its
previously-sent `close_fee`.
*/
if (peer->closing.their_sig) {
/* We want more, they should give more. */
if (peer->closing.our_fee > peer->closing.their_fee) {
if (c->close_fee <= peer->closing.their_fee)
return peer_comms_err(peer,
pkt_err(peer, "Didn't increase close fee"));
} else {
if (c->close_fee >= peer->closing.their_fee)
return peer_comms_err(peer,
pkt_err(peer, "Didn't decrease close fee"));
}
}
/* BOLT #2:
*
* The receiver MUST check `sig` is valid for the close
* transaction with the given `close_fee`, and MUST fail the
* connection if it is not. */
theirsig.stype = SIGHASH_ALL;
if (!proto_to_signature(peer->dstate->secpctx, c->sig, &theirsig.sig))
return peer_comms_err(peer,
pkt_err(peer, "Invalid signature format"));
close_tx = peer_create_close_tx(peer, c->close_fee);
if (!check_tx_sig(peer->dstate->secpctx, close_tx, 0,
NULL, 0,
peer->anchor.witnessscript,
&peer->remote.commitkey, &theirsig))
return peer_comms_err(peer,
pkt_err(peer, "Invalid signature"));
tal_free(peer->closing.their_sig);
peer->closing.their_sig = tal_dup(peer,
struct bitcoin_signature, &theirsig);
peer->closing.their_fee = c->close_fee;
if (peer->closing.our_fee != peer->closing.their_fee) {
/* BOLT #2:
*
* If the receiver agrees with the fee, it SHOULD reply with a
* `close_signature` with the same `close_fee` value,
* otherwise it SHOULD propose a value strictly between the
* received `close_fee` and its previously-sent `close_fee`.
*/
/* Adjust our fee to close on their fee. */
u64 sum;
/* Beware overflow! */
sum = (u64)peer->closing.our_fee + peer->closing.their_fee;
peer->closing.our_fee = sum / 2;
if (peer->closing.our_fee & 1)
peer->closing.our_fee++;
log_info(peer->log, "accept_pkt_close_sig: we change to %"PRIu64,
peer->closing.our_fee);
queue_pkt_close_signature(peer);
}
/* Note corner case: we may *now* agree with them! */
if (peer->closing.our_fee == peer->closing.their_fee) {
log_info(peer->log, "accept_pkt_close_sig: we agree");
/* BOLT #2:
*
* Once a node has sent or received a `close_signature` with
* matching `close_fee` it SHOULD close the connection and
* SHOULD sign and broadcast the final closing transaction.
*/
broadcast_tx(peer, bitcoin_close(peer));
return false;
}
/* FIXME: Dynamic fee! */
return true;
}
/* We can get update_commit in both normal and clearing states. */
static Pkt *handle_pkt_commit(struct peer *peer, const Pkt *pkt)
{
Pkt *err;
struct sha256 preimage;
struct commit_info *ci = new_commit_info(peer);
/* FIXME: We can actually merge these two... */
static const struct state_table commit_changes[] = {
{ RCVD_ADD_REVOCATION, RCVD_ADD_ACK_COMMIT },
{ RCVD_REMOVE_HTLC, RCVD_REMOVE_COMMIT },
{ RCVD_ADD_HTLC, RCVD_ADD_COMMIT },
{ RCVD_REMOVE_REVOCATION, RCVD_REMOVE_ACK_COMMIT }
};
static const struct state_table revocation_changes[] = {
{ RCVD_ADD_ACK_COMMIT, SENT_ADD_ACK_REVOCATION },
{ RCVD_REMOVE_COMMIT, SENT_REMOVE_REVOCATION },
{ RCVD_ADD_COMMIT, SENT_ADD_REVOCATION },
{ RCVD_REMOVE_ACK_COMMIT, SENT_REMOVE_ACK_REVOCATION }
};
ci->sig = tal(ci, struct bitcoin_signature);
err = accept_pkt_commit(peer, pkt, ci->sig);
if (err)
return err;
/* BOLT #2:
*
* A node MUST NOT send an `update_commit` message which does
* not include any updates.
*/
if (!htlcs_changestate(peer, commit_changes, ARRAY_SIZE(commit_changes)))
return pkt_err(peer, "Empty commit");
/* Create new commit info for this commit tx. */
ci->prev = peer->local.commit;
ci->commit_num = ci->prev->commit_num + 1;
ci->revocation_hash = peer->local.next_revocation_hash;
/* BOLT #2:
*
* A receiving node MUST apply all local acked and unacked
* changes except unacked fee changes to the local commitment
*/
/* (We already applied them to staging_cstate as we went) */
ci->cstate = copy_cstate(ci, peer->local.staging_cstate);
ci->tx = create_commit_tx(ci, peer, &ci->revocation_hash,
ci->cstate, LOCAL);
bitcoin_txid(ci->tx, &ci->txid);
/* BOLT #2:
*
* A receiving node MUST apply all local acked and unacked changes
* except unacked fee changes to the local commitment, then it MUST
* check `sig` is valid for that transaction.
*/
if (!check_tx_sig(peer->dstate->secpctx,
ci->tx, 0,
NULL, 0,
peer->anchor.witnessscript,
&peer->remote.commitkey,
ci->sig))
return pkt_err(peer, "Bad signature");
/* Switch to the new commitment. */
peer->local.commit = ci;
peer_get_revocation_hash(peer, ci->commit_num + 1,
&peer->local.next_revocation_hash);
peer->their_commitsigs++;
/* Now, send the revocation. */
/* We have their signature on the current one, right? */
assert(peer->local.commit->sig);
assert(peer->local.commit->commit_num > 0);
if (!htlcs_changestate(peer, revocation_changes,
ARRAY_SIZE(revocation_changes)))
fatal("sent revoke with no changes");
peer_get_revocation_preimage(peer, peer->local.commit->commit_num - 1,
&preimage);
/* Fire off timer if this ack caused new changes */
if (peer_uncommitted_changes(peer))
remote_changes_pending(peer);
queue_pkt_revocation(peer, &preimage, &peer->local.next_revocation_hash);
return NULL;
}
static Pkt *handle_pkt_htlc_add(struct peer *peer, const Pkt *pkt)
{
struct htlc *htlc;
Pkt *err;
err = accept_pkt_htlc_add(peer, pkt, &htlc);
if (err)
return err;
assert(htlc->state == RCVD_ADD_HTLC);
/* BOLT #2:
*
* A node MUST NOT offer `amount_msat` it cannot pay for in
* the remote commitment transaction at the current `fee_rate` (see
* "Fee Calculation" ). A node SHOULD fail the connection if
* this occurs.
*/
if (!cstate_add_htlc(peer->local.staging_cstate, htlc, THEIRS)) {
tal_free(htlc);
return pkt_err(peer, "Cannot afford %"PRIu64" milli-satoshis"
" in our commitment tx",
htlc->msatoshis);
}
return NULL;
}
static Pkt *handle_pkt_htlc_fail(struct peer *peer, const Pkt *pkt)
{
struct htlc *htlc;
Pkt *err;
err = accept_pkt_htlc_fail(peer, pkt, &htlc);
if (err)
return err;
cstate_fail_htlc(peer->local.staging_cstate, htlc, OURS);
/* BOLT #2:
*
* ... and the receiving node MUST add the HTLC fulfill/fail
* to the unacked changeset for its local commitment.
*/
htlc_changestate(htlc, SENT_ADD_ACK_REVOCATION, RCVD_REMOVE_HTLC);
return NULL;
}
static Pkt *handle_pkt_htlc_fulfill(struct peer *peer, const Pkt *pkt)
{
struct htlc *htlc;
Pkt *err;
err = accept_pkt_htlc_fulfill(peer, pkt, &htlc);
if (err)
return err;
/* We can relay this upstream immediately. */
our_htlc_fulfilled(peer, htlc, htlc->r);
/* BOLT #2:
*
* ... and the receiving node MUST add the HTLC fulfill/fail
* to the unacked changeset for its local commitment.
*/
cstate_fulfill_htlc(peer->local.staging_cstate, htlc, OURS);
htlc_changestate(htlc, SENT_ADD_ACK_REVOCATION, RCVD_REMOVE_HTLC);
return NULL;
}
static Pkt *handle_pkt_revocation(struct peer *peer, const Pkt *pkt)
{
Pkt *err;
static const struct state_table changes[] = {
{ SENT_ADD_COMMIT, RCVD_ADD_REVOCATION },
{ SENT_REMOVE_ACK_COMMIT, RCVD_REMOVE_ACK_REVOCATION },
{ SENT_ADD_ACK_COMMIT, RCVD_ADD_ACK_REVOCATION },
{ SENT_REMOVE_COMMIT, RCVD_REMOVE_REVOCATION }
};
err = accept_pkt_revocation(peer, pkt);
if (err)
return err;
/* BOLT #2:
*
* The receiver of `update_revocation`... MUST add the remote
* unacked changes to the set of local acked changes.
*/
if (!htlcs_changestate(peer, changes, ARRAY_SIZE(changes)))
fatal("Revocation received but we made empty commitment?");
return NULL;
}
static void peer_calculate_close_fee(struct peer *peer)
{
/* Use actual worst-case length of close tx: based on BOLT#02's
* commitment tx numbers, but only 1 byte for output count */
const uint64_t txsize = 41 + 221 + 10 + 32 + 32;
uint64_t maxfee;
/* FIXME: Dynamic fee */
peer->closing.our_fee
= fee_by_feerate(txsize, peer->dstate->config.closing_fee_rate);
/* BOLT #2:
* The sender MUST set `close_fee` lower than or equal to the
* fee of the final commitment transaction, and MUST set
* `close_fee` to an even number of satoshis.
*/
maxfee = commit_tx_fee(peer->local.commit->tx, peer->anchor.satoshis);
if (peer->closing.our_fee > maxfee) {
/* This shouldn't happen: we never accept a commit fee
* less than the min_rate, which is greater than the
* closing_fee_rate. Also, our txsize estimate for
* the closing tx is 2 bytes smaller than the commitment tx. */
log_unusual(peer->log,
"Closing fee %"PRIu64" exceeded commit fee %"PRIu64", reducing.",
peer->closing.our_fee, maxfee);
peer->closing.our_fee = maxfee;
/* This can happen if actual commit txfee is odd. */
if (peer->closing.our_fee & 1)
peer->closing.our_fee--;
}
assert(!(peer->closing.our_fee & 1));
}
/* This is the io loop while we're clearing. */
static bool clearing_pkt_in(struct peer *peer, const Pkt *pkt)
{
Pkt *err = NULL;
assert(peer->state == STATE_CLEARING
|| peer->state == STATE_CLEARING_COMMITTING);
switch (pkt->pkt_case) {
case PKT__PKT_UPDATE_REVOCATION:
if (peer->state == STATE_CLEARING)
err = pkt_err_unexpected(peer, pkt);
else {
err = handle_pkt_revocation(peer, pkt);
if (!err) {
set_peer_state(peer, STATE_CLEARING, __func__);
peer_update_complete(peer);
}
}
break;
case PKT__PKT_UPDATE_ADD_HTLC:
/* BOLT #2:
*
* A node MUST NOT send a `update_add_htlc` after a
* `close_clearing` */
if (peer->closing.their_script)
err = pkt_err(peer, "Update during clearing");
else
err = handle_pkt_htlc_add(peer, pkt);
break;
case PKT__PKT_CLOSE_CLEARING:
/* BOLT #2:
*
* A node... MUST NOT send more than one `close_clearing`. */
if (peer->closing.their_script)
err = pkt_err_unexpected(peer, pkt);
else
err = accept_pkt_close_clearing(peer, pkt);
break;
case PKT__PKT_UPDATE_FULFILL_HTLC:
err = handle_pkt_htlc_fulfill(peer, pkt);
break;
case PKT__PKT_UPDATE_FAIL_HTLC:
err = handle_pkt_htlc_fail(peer, pkt);
break;
case PKT__PKT_UPDATE_COMMIT:
err = handle_pkt_commit(peer, pkt);
break;
case PKT__PKT_ERROR:
peer_unexpected_pkt(peer, pkt);
return peer_comms_err(peer, NULL);
case PKT__PKT_AUTH:
case PKT__PKT_OPEN:
case PKT__PKT_OPEN_ANCHOR:
case PKT__PKT_OPEN_COMMIT_SIG:
case PKT__PKT_OPEN_COMPLETE:
case PKT__PKT_CLOSE_SIGNATURE:
default:
peer_unexpected_pkt(peer, pkt);
err = pkt_err_unexpected(peer, pkt);
break;
}
if (err)
return peer_comms_err(peer, err);
if (!committed_to_htlcs(peer)) {
set_peer_state(peer, STATE_MUTUAL_CLOSING, __func__);
peer_calculate_close_fee(peer);
queue_pkt_close_signature(peer);
}
return true;
}
static void peer_start_clearing(struct peer *peer)
{
assert(peer->state == STATE_CLEARING
|| peer->state == STATE_CLEARING_COMMITTING);
/* If they started close, we might not have sent ours. */
if (!peer->closing.our_script) {
u8 *redeemscript = bitcoin_redeem_single(peer,
peer->dstate->secpctx,
&peer->local.finalkey);
peer->closing.our_script = scriptpubkey_p2sh(peer, redeemscript);
tal_free(redeemscript);
/* BOLT #2:
*
* A node SHOULD send a `close_clearing` (if it has
* not already) after receiving `close_clearing`.
*/
queue_pkt_close_clearing(peer);
}
/* Catch case where we've exchanged and had no HTLCs anyway. */
if (peer->closing.our_script && peer->closing.their_script
&& !committed_to_htlcs(peer)) {
set_peer_state(peer, STATE_MUTUAL_CLOSING, __func__);
peer_calculate_close_fee(peer);
queue_pkt_close_signature(peer);
}
}
/* This is the io loop while we're in normal mode. */
static bool normal_pkt_in(struct peer *peer, const Pkt *pkt)
{
Pkt *err = NULL;
assert(peer->state == STATE_NORMAL
|| peer->state == STATE_NORMAL_COMMITTING);
switch (pkt->pkt_case) {
case PKT_UPDATE_ADD_HTLC:
err = handle_pkt_htlc_add(peer, pkt);
break;
case PKT_UPDATE_FULFILL_HTLC:
err = handle_pkt_htlc_fulfill(peer, pkt);
break;
case PKT_UPDATE_FAIL_HTLC:
err = handle_pkt_htlc_fail(peer, pkt);
break;
case PKT_UPDATE_COMMIT:
err = handle_pkt_commit(peer, pkt);
break;
case PKT_CLOSE_CLEARING:
err = accept_pkt_close_clearing(peer, pkt);
if (err)
break;
if (peer->state == STATE_NORMAL)
set_peer_state(peer, STATE_CLEARING, __func__);
else {
assert(peer->state == STATE_NORMAL_COMMITTING);
set_peer_state(peer, STATE_CLEARING_COMMITTING,
__func__);
}
peer_start_clearing(peer);
return true;
case PKT_UPDATE_REVOCATION:
if (peer->state == STATE_NORMAL_COMMITTING) {
err = handle_pkt_revocation(peer, pkt);
if (!err) {
peer_update_complete(peer);
set_peer_state(peer, STATE_NORMAL, __func__);
}
break;
}
/* Fall thru. */
default:
return peer_received_unexpected_pkt(peer, pkt);
}
if (err) {
return peer_comms_err(peer, err);
}
return true;
}
static void state_single(struct peer *peer,
const enum state_input input,
const Pkt *pkt)
{
const struct bitcoin_tx *broadcast;
enum state newstate;
size_t old_outpkts = tal_count(peer->outpkt);
newstate = state(peer, input, pkt, &broadcast);
set_peer_state(peer, newstate, input_name(input));
/* If we added uncommitted changes, we should have set them to send. */
if (peer_uncommitted_changes(peer))
assert(peer->commit_timer);
if (tal_count(peer->outpkt) > old_outpkts) {
Pkt *outpkt = peer->outpkt[old_outpkts];
log_add(peer->log, " (out %s)", pkt_name(outpkt->pkt_case));
}
if (broadcast)
broadcast_tx(peer, broadcast);
if (state_is_error(peer->state)) {
/* Breakdown is common, others less so. */
if (peer->state != STATE_ERR_BREAKDOWN)
log_broken(peer->log, "Entered error state %s",
state_name(peer->state));
peer_breakdown(peer);
/* Start output if not running already; it will close conn. */
io_wake(peer);
}
}
static void state_event(struct peer *peer,
const enum state_input input,
const Pkt *pkt)
{
if (!state_is_opening(peer->state)) {
log_unusual(peer->log,
"Unexpected input %s while state %s",
input_name(input), state_name(peer->state));
} else {
state_single(peer, input, pkt);
}
}
/* Create a HTLC fulfill transaction for closing_onchain.tx[out_num]. */
static const struct bitcoin_tx *htlc_fulfill_tx(const struct peer *peer,
unsigned int out_num)
{
struct bitcoin_tx *tx = bitcoin_tx(peer, 1, 1);
const struct htlc *htlc = peer->closing_onchain.htlcs[out_num];
const u8 *wscript = peer->closing_onchain.wscripts[out_num];
struct bitcoin_signature sig;
u64 fee, satoshis;
assert(htlc->r);
tx->input[0].index = out_num;
tx->input[0].txid = peer->closing_onchain.txid;
satoshis = htlc->msatoshis / 1000;
tx->input[0].amount = tal_dup(tx->input, u64, &satoshis);
tx->input[0].sequence_number = bitcoin_nsequence(&peer->remote.locktime);
/* Using a new output address here would be useless: they can tell
* it's their HTLC, and that we collected it via rval. */
tx->output[0].script = scriptpubkey_p2sh(tx,
bitcoin_redeem_single(tx,
peer->dstate->secpctx,
&peer->local.finalkey));
tx->output[0].script_length = tal_count(tx->output[0].script);
log_debug(peer->log, "Pre-witness txlen = %zu\n",
measure_tx_cost(tx) / 4);
assert(measure_tx_cost(tx) == 83 * 4);
/* Witness length can vary, due to DER encoding of sigs, but we
* use 539 from an example run. */
/* FIXME: Dynamic fees! */
fee = fee_by_feerate(83 + 539 / 4,
peer->dstate->config.closing_fee_rate);
/* FIXME: Fail gracefully in these cases (not worth collecting) */
if (fee > satoshis || is_dust_amount(satoshis - fee))
fatal("HTLC fulfill amount of %"PRIu64" won't cover fee %"PRIu64,
satoshis, fee);
tx->output[0].amount = satoshis - fee;
sig.stype = SIGHASH_ALL;
peer_sign_htlc_fulfill(peer, tx, wscript, &sig.sig);
tx->input[0].witness = bitcoin_witness_htlc(tx, peer->dstate->secpctx,
htlc->r, &sig, wscript);
log_debug(peer->log, "tx cost for htlc fulfill tx: %zu",
measure_tx_cost(tx));
return tx;
}
/* FIXME: Reason! */
static bool command_htlc_fail(struct peer *peer, struct htlc *htlc)
{
/* If onchain, nothing we can do. */
if (!state_can_remove_htlc(peer->state))
return false;
/* BOLT #2:
*
* The sending node MUST add the HTLC fulfill/fail to the
* unacked changeset for its remote commitment
*/
assert(cstate_htlc_by_id(peer->remote.staging_cstate, htlc->id, THEIRS)
== htlc);
cstate_fail_htlc(peer->remote.staging_cstate, htlc, THEIRS);
htlc_changestate(htlc, RCVD_ADD_ACK_REVOCATION, SENT_REMOVE_HTLC);
remote_changes_pending(peer);
queue_pkt_htlc_fail(peer, htlc);
return true;
}
/* BOLT #onchain:
*
* If the node receives... a redemption preimage for an unresolved *commitment
* tx* output it was offered, it MUST *resolve* the output by spending it using
* the preimage.
*/
static bool fulfill_onchain(struct peer *peer, struct htlc *htlc)
{
size_t i;
for (i = 0; i < tal_count(peer->closing_onchain.htlcs); i++) {
if (peer->closing_onchain.htlcs[i] == htlc) {
/* Already irrevocably resolved? */
if (peer->closing_onchain.resolved[i])
return false;
peer->closing_onchain.resolved[i]
= htlc_fulfill_tx(peer, i);
broadcast_tx(peer, peer->closing_onchain.resolved[i]);
return true;
}
}
fatal("Unknown HTLC to fulfill onchain");
}
static bool command_htlc_fulfill(struct peer *peer, struct htlc *htlc)
{
if (peer->state == STATE_CLOSE_ONCHAIN_THEIR_UNILATERAL
|| peer->state == STATE_CLOSE_ONCHAIN_OUR_UNILATERAL) {
return fulfill_onchain(peer, htlc);
}
if (!state_can_remove_htlc(peer->state))
return false;
/* BOLT #2:
*
* The sending node MUST add the HTLC fulfill/fail to the
* unacked changeset for its remote commitment
*/
assert(cstate_htlc_by_id(peer->remote.staging_cstate, htlc->id, THEIRS)
== htlc);
cstate_fulfill_htlc(peer->remote.staging_cstate, htlc, THEIRS);
htlc_changestate(htlc, RCVD_ADD_ACK_REVOCATION, SENT_REMOVE_HTLC);
remote_changes_pending(peer);
queue_pkt_htlc_fulfill(peer, htlc);
return true;
}
struct htlc *command_htlc_add(struct peer *peer, u64 msatoshis,
unsigned int expiry,
const struct sha256 *rhash,
struct htlc *src,
const u8 *route)
{
struct channel_state *cstate;
struct abs_locktime locktime;
struct htlc *htlc;
if (!blocks_to_abs_locktime(expiry, &locktime)) {
log_unusual(peer->log, "add_htlc: fail: bad expiry %u", expiry);
return NULL;
}
if (expiry < get_block_height(peer->dstate) + peer->dstate->config.min_htlc_expiry) {
log_unusual(peer->log, "add_htlc: fail: expiry %u is too soon",
expiry);
return NULL;
}
if (expiry > get_block_height(peer->dstate) + peer->dstate->config.max_htlc_expiry) {
log_unusual(peer->log, "add_htlc: fail: expiry %u is too far",
expiry);
return NULL;
}
/* BOLT #2:
*
* A node MUST NOT add a HTLC if it would result in it
* offering more than 300 HTLCs in the remote commitment transaction.
*/
if (tal_count(peer->remote.staging_cstate->side[OURS].htlcs) == 300) {
log_unusual(peer->log, "add_htlc: fail: already at limit");
return NULL;
}
if (!state_can_add_htlc(peer->state)) {
log_unusual(peer->log, "add_htlc: fail: peer state %s",
state_name(peer->state));
return NULL;
}
htlc = peer_new_htlc(peer, peer->htlc_id_counter,
msatoshis, rhash, expiry, route, tal_count(route),
src, SENT_ADD_HTLC);
/* FIXME: BOLT is not correct here: we should say IFF we cannot
* afford it in remote at its own current proposed fee-rate. */
/* BOLT #2:
*
* A node MUST NOT offer `amount_msat` it cannot pay for in
* the remote commitment transaction at the current `fee_rate`
*/
cstate = copy_cstate(peer, peer->remote.staging_cstate);
if (!cstate_add_htlc(cstate, htlc, OURS)) {
log_unusual(peer->log, "add_htlc: fail: Cannot afford %"PRIu64
" milli-satoshis in their commit tx",
msatoshis);
return tal_free(htlc);
}
tal_free(cstate);
cstate = copy_cstate(peer, peer->local.staging_cstate);
if (!cstate_add_htlc(cstate, htlc, OURS)) {
log_unusual(peer->log, "add_htlc: fail: Cannot afford %"PRIu64
" milli-satoshis in our commit tx",
msatoshis);
return tal_free(htlc);
}
tal_free(cstate);
/* BOLT #2:
*
* The sending node MUST add the HTLC addition to the unacked
* changeset for its remote commitment
*/
if (!cstate_add_htlc(peer->remote.staging_cstate, htlc, OURS))
fatal("Could not add HTLC?");
remote_changes_pending(peer);
queue_pkt_htlc_add(peer, htlc);
/* Make sure we never offer the same one twice. */
peer->htlc_id_counter++;
return htlc;
}
static struct io_plan *pkt_out(struct io_conn *conn, struct peer *peer)
{
Pkt *out;
size_t n = tal_count(peer->outpkt);
if (n == 0) {
/* We close the connection once we've sent everything. */
if (!state_can_io(peer->state)) {
log_debug(peer->log, "pkt_out: no IO possible, closing");
return io_close(conn);
}
return io_out_wait(conn, peer, pkt_out, peer);
}
if (peer->fake_close || !peer->output_enabled)
return io_out_wait(conn, peer, pkt_out, peer);
out = peer->outpkt[0];
memmove(peer->outpkt, peer->outpkt + 1, (sizeof(*peer->outpkt)*(n-1)));
tal_resize(&peer->outpkt, n-1);
return peer_write_packet(conn, peer, out, pkt_out);
}
static struct io_plan *pkt_in(struct io_conn *conn, struct peer *peer)
{
bool keep_going;
/* We ignore packets if they tell us to, or we're closing already */
if (peer->fake_close || !state_can_io(peer->state))
keep_going = true;
else if (state_is_normal(peer->state))
keep_going = normal_pkt_in(peer, peer->inpkt);
else if (state_is_clearing(peer->state))
keep_going = clearing_pkt_in(peer, peer->inpkt);
else if (peer->state == STATE_MUTUAL_CLOSING)
keep_going = closing_pkt_in(peer, peer->inpkt);
else {
state_event(peer, peer->inpkt->pkt_case, peer->inpkt);
keep_going = true;
}
peer->inpkt = tal_free(peer->inpkt);
if (keep_going)
return peer_read_packet(conn, peer, pkt_in);
else
return peer_close(conn, peer);
}
/* Crypto is on, we are live. */
static struct io_plan *peer_crypto_on(struct io_conn *conn, struct peer *peer)
{
peer_secrets_init(peer);
peer_get_revocation_hash(peer, 0, &peer->local.next_revocation_hash);
assert(peer->state == STATE_INIT);
state_event(peer, peer->local.offer_anchor, NULL);
return io_duplex(conn,
peer_read_packet(conn, peer, pkt_in),
pkt_out(conn, peer));
}
static void destroy_peer(struct peer *peer)
{
if (peer->conn)
io_close(peer->conn);
list_del_from(&peer->dstate->peers, &peer->list);
}
static void peer_disconnect(struct io_conn *conn, struct peer *peer)
{
log_info(peer->log, "Disconnected");
/* No longer connected. */
peer->conn = NULL;
/* Not even set up yet? Simply free.*/
if (peer->state == STATE_INIT) {
tal_free(peer);
return;
}
/* Completely dead? Free it now. */
if (peer->state == STATE_CLOSED) {
io_break(peer);
return;
}
/* This is an unexpected close. */
if (!state_is_onchain(peer->state) && !state_is_error(peer->state)) {
/* FIXME: Try to reconnect. */
set_peer_state(peer, STATE_ERR_BREAKDOWN, "peer_disconnect");
peer_breakdown(peer);
}
}
static void do_commit(struct peer *peer, struct command *jsoncmd)
{
struct commit_info *ci;
static const struct state_table changes[] = {
{ SENT_ADD_HTLC, SENT_ADD_COMMIT },
{ SENT_REMOVE_REVOCATION, SENT_REMOVE_ACK_COMMIT },
{ SENT_ADD_REVOCATION, SENT_ADD_ACK_COMMIT},
{ SENT_REMOVE_HTLC, SENT_REMOVE_COMMIT}
};
/* We can have changes we suggested, or changes they suggested. */
if (!peer_uncommitted_changes(peer)) {
log_debug(peer->log, "do_commit: no changes to commit");
if (jsoncmd)
command_fail(jsoncmd, "no changes to commit");
return;
}
log_debug(peer->log, "do_commit: sending commit command");
assert(state_can_commit(peer->state));
assert(!peer->commit_jsoncmd);
peer->commit_jsoncmd = jsoncmd;
ci = new_commit_info(peer);
assert(!peer->their_prev_revocation_hash);
peer->their_prev_revocation_hash
= tal_dup(peer, struct sha256,
&peer->remote.commit->revocation_hash);
/* BOLT #2:
*
* A node MUST NOT send an `update_commit` message which does
* not include any updates.
*/
if (!htlcs_changestate(peer, changes, ARRAY_SIZE(changes)))
fatal("sent commit with no changes");
/* Create new commit info for this commit tx. */
ci->prev = peer->remote.commit;
ci->commit_num = ci->prev->commit_num + 1;
ci->revocation_hash = peer->remote.next_revocation_hash;
/* BOLT #2:
*
* A sending node MUST apply all remote acked and unacked
* changes except unacked fee changes to the remote commitment
* before generating `sig`. */
ci->cstate = copy_cstate(ci, peer->remote.staging_cstate);
ci->tx = create_commit_tx(ci, peer, &ci->revocation_hash,
ci->cstate, REMOTE);
bitcoin_txid(ci->tx, &ci->txid);
log_debug(peer->log, "Signing tx for %u/%u msatoshis, %zu/%zu htlcs",
ci->cstate->side[OURS].pay_msat,
ci->cstate->side[THEIRS].pay_msat,
tal_count(ci->cstate->side[OURS].htlcs),
tal_count(ci->cstate->side[THEIRS].htlcs));
log_add_struct(peer->log, " (txid %s)", struct sha256_double, &ci->txid);
ci->sig = tal(ci, struct bitcoin_signature);
ci->sig->stype = SIGHASH_ALL;
peer_sign_theircommit(peer, ci->tx, &ci->sig->sig);
/* Switch to the new commitment. */
peer->remote.commit = ci;
peer_add_their_commit(peer, &ci->txid, ci->commit_num);
queue_pkt_commit(peer);
if (peer->state == STATE_CLEARING) {
set_peer_state(peer, STATE_CLEARING_COMMITTING, __func__);
} else {
assert(peer->state == STATE_NORMAL);
set_peer_state(peer, STATE_NORMAL_COMMITTING, __func__);
}
}
static void try_commit(struct peer *peer)
{
peer->commit_timer = NULL;
if (state_can_commit(peer->state))
do_commit(peer, NULL);
else {
/* FIXME: try again when we receive revocation, rather
* than using timer! */
log_debug(peer->log, "try_commit: state=%s, re-queueing timer",
state_name(peer->state));
remote_changes_pending(peer);
}
}
struct commit_info *new_commit_info(const tal_t *ctx)
{
struct commit_info *ci = talz(ctx, struct commit_info);
return ci;
}
static struct peer *new_peer(struct lightningd_state *dstate,
struct io_conn *conn,
int addr_type, int addr_protocol,
enum state_input offer_anchor,
const char *in_or_out)
{
struct peer *peer = tal(dstate, struct peer);
assert(offer_anchor == CMD_OPEN_WITH_ANCHOR
|| offer_anchor == CMD_OPEN_WITHOUT_ANCHOR);
/* FIXME: Stop listening if too many peers? */
list_add(&dstate->peers, &peer->list);
peer->state = STATE_INIT;
peer->id = NULL;
peer->dstate = dstate;
peer->addr.type = addr_type;
peer->addr.protocol = addr_protocol;
peer->io_data = NULL;
peer->secrets = NULL;
list_head_init(&peer->watches);
peer->outpkt = tal_arr(peer, Pkt *, 0);
peer->commit_jsoncmd = NULL;
list_head_init(&peer->outgoing_txs);
list_head_init(&peer->pay_commands);
list_head_init(&peer->their_commits);
peer->anchor.ok_depth = -1;
peer->their_commitsigs = 0;
peer->cur_commit.watch = NULL;
peer->closing.their_sig = NULL;
peer->closing.our_script = NULL;
peer->closing.their_script = NULL;
peer->closing_onchain.tx = NULL;
peer->closing_onchain.resolved = NULL;
peer->closing_onchain.htlcs = NULL;
peer->closing_onchain.wscripts = NULL;
peer->commit_timer = NULL;
peer->nc = NULL;
peer->their_prev_revocation_hash = NULL;
/* Make it different from other node (to catch bugs!), but a
* round number for simple eyeballing. */
peer->htlc_id_counter = pseudorand(1ULL << 32) * 1000;
/* If we free peer, conn should be closed, but can't be freed
* immediately so don't make peer a parent. */
peer->conn = conn;
peer->fake_close = false;
peer->output_enabled = true;
io_set_finish(conn, peer_disconnect, peer);
peer->local.offer_anchor = offer_anchor;
if (!blocks_to_rel_locktime(dstate->config.locktime_blocks,
&peer->local.locktime))
fatal("Could not convert locktime_blocks");
peer->local.mindepth = dstate->config.anchor_confirms;
peer->local.commit_fee_rate = dstate->config.commitment_fee_rate;
peer->local.commit = peer->remote.commit = NULL;
peer->local.staging_cstate = peer->remote.staging_cstate = NULL;
htlc_map_init(&peer->htlcs);
/* FIXME: Attach IO logging for this peer. */
tal_add_destructor(peer, destroy_peer);
peer->addr.addrlen = sizeof(peer->addr.saddr);
if (getpeername(io_conn_fd(conn), &peer->addr.saddr.s,
&peer->addr.addrlen) != 0) {
log_unusual(dstate->base_log,
"Could not get address for peer: %s",
strerror(errno));
return tal_free(peer);
}
peer->log = new_log(peer, dstate->log_record, "%s%s:%s:",
log_prefix(dstate->base_log), in_or_out,
netaddr_name(peer, &peer->addr));
return peer;
}
/* Unused for the moment. */
#if 0
static u64 peer_commitsigs_received(struct peer *peer)
{
return peer->their_commitsigs;
}
static u64 peer_revocations_received(struct peer *peer)
{
/* How many preimages we've received. */
return -peer->their_preimages.min_index;
}
#endif
static void htlc_destroy(struct htlc *htlc)
{
if (!htlc_map_del(&htlc->peer->htlcs, htlc))
fatal("Could not find htlc to destroy");
}
struct htlc *peer_new_htlc(struct peer *peer,
u64 id,
u64 msatoshis,
const struct sha256 *rhash,
u32 expiry,
const u8 *route,
size_t routelen,
struct htlc *src,
enum htlc_state state)
{
struct htlc *h = tal(peer, struct htlc);
h->peer = peer;
assert(state == SENT_ADD_HTLC || state == RCVD_ADD_HTLC);
h->state = state;
h->id = id;
h->msatoshis = msatoshis;
h->rhash = *rhash;
h->r = NULL;
if (!blocks_to_abs_locktime(expiry, &h->expiry))
fatal("Invalid HTLC expiry %u", expiry);
h->routing = tal_dup_arr(h, u8, route, routelen, 0);
h->src = src;
if (htlc_owner(h) == LOCAL) {
if (src) {
h->deadline = abs_locktime_to_blocks(&src->expiry)
- peer->dstate->config.deadline_blocks;
} else
/* If we're paying, give it a little longer. */
h->deadline = expiry
+ peer->dstate->config.min_htlc_expiry;
} else {
assert(htlc_owner(h) == REMOTE);
}
htlc_map_add(&peer->htlcs, h);
tal_add_destructor(h, htlc_destroy);
return h;
}
static struct io_plan *crypto_on_out(struct io_conn *conn,
struct lightningd_state *dstate,
struct io_data *iod,
const struct pubkey *id,
struct json_connecting *connect)
{
/* Initiator currently funds channel */
struct peer *peer = new_peer(dstate, conn, SOCK_STREAM, IPPROTO_TCP,
CMD_OPEN_WITH_ANCHOR, "out");
if (!peer) {
command_fail(connect->cmd, "Failed to make peer for %s:%s",
connect->name, connect->port);
return io_close(conn);
}
peer->io_data = tal_steal(peer, iod);
peer->id = tal_dup(peer, struct pubkey, id);
peer->anchor.input = tal_steal(peer, connect->input);
command_success(connect->cmd, null_response(connect));
return peer_crypto_on(conn, peer);
}
static struct io_plan *peer_connected_out(struct io_conn *conn,
struct lightningd_state *dstate,
struct json_connecting *connect)
{
log_debug(dstate->base_log, "Connected out to %s:%s",
connect->name, connect->port);
return peer_crypto_setup(conn, dstate, NULL, crypto_on_out, connect);
}
static struct io_plan *crypto_on_in(struct io_conn *conn,
struct lightningd_state *dstate,
struct io_data *iod,
const struct pubkey *id,
void *unused)
{
/* Initiator currently funds channel */
struct peer *peer = new_peer(dstate, conn, SOCK_STREAM, IPPROTO_TCP,
CMD_OPEN_WITHOUT_ANCHOR, "in");
if (!peer)
return io_close(conn);
peer->io_data = tal_steal(peer, iod);
peer->id = tal_dup(peer, struct pubkey, id);
return peer_crypto_on(conn, peer);
}
static struct io_plan *peer_connected_in(struct io_conn *conn,
struct lightningd_state *dstate)
{
/* FIXME: log incoming address. */
log_debug(dstate->base_log, "Connected in");
return peer_crypto_setup(conn, dstate, NULL, crypto_on_in, NULL);
}
static int make_listen_fd(struct lightningd_state *dstate,
int domain, void *addr, socklen_t len)
{
int fd = socket(domain, SOCK_STREAM, 0);
if (fd < 0) {
log_debug(dstate->base_log, "Failed to create %u socket: %s",
domain, strerror(errno));
return -1;
}
if (addr) {
int on = 1;
/* Re-use, please.. */
if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)))
log_unusual(dstate->base_log,
"Failed setting socket reuse: %s",
strerror(errno));
if (bind(fd, addr, len) != 0) {
log_unusual(dstate->base_log,
"Failed to bind on %u socket: %s",
domain, strerror(errno));
goto fail;
}
}
if (listen(fd, 5) != 0) {
log_unusual(dstate->base_log,
"Failed to listen on %u socket: %s",
domain, strerror(errno));
goto fail;
}
return fd;
fail:
close_noerr(fd);
return -1;
}
void setup_listeners(struct lightningd_state *dstate, unsigned int portnum)
{
struct sockaddr_in addr;
struct sockaddr_in6 addr6;
socklen_t len;
int fd1, fd2;
u16 listen_port;
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = INADDR_ANY;
addr.sin_port = htons(portnum);
memset(&addr6, 0, sizeof(addr6));
addr6.sin6_family = AF_INET6;
addr6.sin6_addr = in6addr_any;
addr6.sin6_port = htons(portnum);
/* IPv6, since on Linux that (usually) binds to IPv4 too. */
fd1 = make_listen_fd(dstate, AF_INET6, portnum ? &addr6 : NULL,
sizeof(addr6));
if (fd1 >= 0) {
struct sockaddr_in6 in6;
len = sizeof(in6);
if (getsockname(fd1, (void *)&in6, &len) != 0) {
log_unusual(dstate->base_log,
"Failed get IPv6 sockname: %s",
strerror(errno));
close_noerr(fd1);
} else {
addr.sin_port = in6.sin6_port;
listen_port = ntohs(addr.sin_port);
log_info(dstate->base_log,
"Creating IPv6 listener on port %u",
listen_port);
io_new_listener(dstate, fd1, peer_connected_in, dstate);
}
}
/* Just in case, aim for the same port... */
fd2 = make_listen_fd(dstate, AF_INET,
addr.sin_port ? &addr : NULL, sizeof(addr));
if (fd2 >= 0) {
len = sizeof(addr);
if (getsockname(fd2, (void *)&addr, &len) != 0) {
log_unusual(dstate->base_log,
"Failed get IPv4 sockname: %s",
strerror(errno));
close_noerr(fd2);
} else {
listen_port = ntohs(addr.sin_port);
log_info(dstate->base_log,
"Creating IPv4 listener on port %u",
listen_port);
io_new_listener(dstate, fd2, peer_connected_in, dstate);
}
}
if (fd1 < 0 && fd2 < 0)
fatal("Could not bind to a network address");
}
static void peer_failed(struct lightningd_state *dstate,
struct json_connecting *connect)
{
/* FIXME: Better diagnostics! */
command_fail(connect->cmd, "Failed to connect to peer %s:%s",
connect->name, connect->port);
}
static void json_connect(struct command *cmd,
const char *buffer, const jsmntok_t *params)
{
struct json_connecting *connect;
jsmntok_t *host, *port, *txtok;
struct bitcoin_tx *tx;
int output;
size_t txhexlen;
if (!json_get_params(buffer, params,
"host", &host,
"port", &port,
"tx", &txtok,
NULL)) {
command_fail(cmd, "Need host, port and tx to a wallet address");
return;
}
connect = tal(cmd, struct json_connecting);
connect->cmd = cmd;
connect->name = tal_strndup(connect, buffer + host->start,
host->end - host->start);
connect->port = tal_strndup(connect, buffer + port->start,
port->end - port->start);
connect->input = tal(connect, struct anchor_input);
txhexlen = txtok->end - txtok->start;
tx = bitcoin_tx_from_hex(connect->input, buffer + txtok->start,
txhexlen);
if (!tx) {
command_fail(cmd, "'%.*s' is not a valid transaction",
txtok->end - txtok->start,
buffer + txtok->start);
return;
}
bitcoin_txid(tx, &connect->input->txid);
/* Find an output we know how to spend. */
connect->input->w = NULL;
for (output = 0; output < tx->output_count; output++) {
connect->input->w
= wallet_can_spend(cmd->dstate, &tx->output[output]);
if (connect->input->w)
break;
}
if (!connect->input->w) {
command_fail(cmd, "Tx doesn't send to wallet address");
return;
}
connect->input->index = output;
connect->input->amount = tx->output[output].amount;
if (!dns_resolve_and_connect(cmd->dstate, connect->name, connect->port,
peer_connected_out, peer_failed, connect)) {
command_fail(cmd, "DNS failed");
return;
}
}
const struct json_command connect_command = {
"connect",
json_connect,
"Connect to a {host} at {port} offering anchor of {satoshis}",
"Returns an empty result on success"
};
/* Have any of our HTLCs passed their deadline? */
static bool any_deadline_past(struct peer *peer,
const struct channel_state *cstate)
{
size_t i;
u32 height = get_block_height(peer->dstate);
struct htlc **htlcs = cstate->side[OURS].htlcs;
for (i = 0; i < tal_count(htlcs); i++) {
if (height >= htlcs[i]->deadline) {
log_unusual_struct(peer->log,
"HTLC %s deadline has passed",
struct htlc, htlcs[i]);
return true;
}
}
return false;
}
static void check_htlc_expiry(struct peer *peer)
{
size_t i;
u32 height = get_block_height(peer->dstate);
again:
/* Check their currently still-existing htlcs for expiry:
* We eliminate them from staging as we go. */
for (i = 0; i < tal_count(peer->remote.staging_cstate->side[THEIRS].htlcs); i++) {
struct htlc *htlc = peer->remote.staging_cstate->side[THEIRS].htlcs[i];
assert(!abs_locktime_is_seconds(&htlc->expiry));
/* We give it an extra block, to avoid the worst of the
* inter-node timing issues. */
if (height <= abs_locktime_to_blocks(&htlc->expiry))
continue;
/* This can fail only if we're in an error state. */
if (!command_htlc_fail(peer, htlc))
return;
goto again;
}
/* BOLT #2:
*
* A node MUST NOT offer a HTLC after this deadline, and MUST
* fail the connection if an HTLC which it offered is in
* either node's current commitment transaction past this
* deadline.
*/
/* To save logic elsewhere (ie. to avoid signing a new commit with a
* past-deadline HTLC) we also check staged HTLCs.
*/
if (!state_is_normal(peer->state))
return;
if (any_deadline_past(peer, peer->remote.staging_cstate)
|| any_deadline_past(peer, peer->local.staging_cstate)
|| any_deadline_past(peer, peer->remote.commit->cstate)
|| any_deadline_past(peer, peer->local.commit->cstate)) {
set_peer_state(peer, STATE_ERR_BREAKDOWN, __func__);
peer_breakdown(peer);
}
}
static enum watch_result anchor_depthchange(struct peer *peer,
unsigned int depth,
const struct sha256_double *txid,
void *unused)
{
/* Still waiting for it to reach depth? */
if (state_is_opening(peer->state)) {
if ((int)depth >= peer->anchor.ok_depth) {
state_event(peer, BITCOIN_ANCHOR_DEPTHOK, NULL);
peer->anchor.ok_depth = -1;
}
} else if (depth == 0)
/* FIXME: Report losses! */
fatal("Funding transaction was unspent!");
/* Since this gets called on every new block, check HTLCs here. */
check_htlc_expiry(peer);
return KEEP_WATCHING;
}
static bool outputscript_eq(const struct bitcoin_tx_output *out,
size_t i, const u8 *script)
{
if (out[i].script_length != tal_count(script))
return false;
return memcmp(out[i].script, script, out[i].script_length) == 0;
}
/* This tx is their commitment;
* fill in closing_onchain.htlcs[], wscripts[], to_us_idx and to_them_idx */
static bool map_onchain_outputs(struct peer *peer,
const struct sha256 *rhash,
const struct bitcoin_tx *tx,
enum htlc_side side,
unsigned int commit_num)
{
u8 *to_us, *to_them, *to_them_wscript, *to_us_wscript;
struct htlc_output_map *hmap;
size_t i;
peer->closing_onchain.to_us_idx = peer->closing_onchain.to_them_idx = -1;
peer->closing_onchain.htlcs
= tal_arr(tx, struct htlc *, tx->output_count);
peer->closing_onchain.wscripts
= tal_arr(tx, const u8 *, tx->output_count);
to_us = commit_output_to_us(tx, peer, rhash, side, &to_us_wscript);
to_them = commit_output_to_them(tx, peer, rhash, side,
&to_them_wscript);
/* Now generate the wscript hashes for every possible HTLC. */
hmap = get_htlc_output_map(tx, peer, rhash, side, commit_num);
for (i = 0; i < tx->output_count; i++) {
log_debug(peer->log, "%s: output %zi", __func__, i);
if (peer->closing_onchain.to_us_idx == -1
&& outputscript_eq(tx->output, i, to_us)) {
log_add(peer->log, " -> to us");
peer->closing_onchain.htlcs[i] = NULL;
peer->closing_onchain.wscripts[i] = to_us_wscript;
peer->closing_onchain.to_us_idx = i;
continue;
}
if (peer->closing_onchain.to_them_idx == -1
&& outputscript_eq(tx->output, i, to_them)) {
log_add(peer->log, " -> to them");
peer->closing_onchain.htlcs[i] = NULL;
peer->closing_onchain.wscripts[i] = to_them_wscript;
peer->closing_onchain.to_them_idx = i;
continue;
}
/* Must be an HTLC output */
peer->closing_onchain.htlcs[i] = txout_get_htlc(hmap,
tx->output[i].script,
tx->output[i].script_length,
peer->closing_onchain.wscripts+i);
if (!peer->closing_onchain.htlcs[i]) {
log_add(peer->log, "no HTLC found");
goto fail;
}
tal_steal(peer->closing_onchain.htlcs,
peer->closing_onchain.htlcs[i]);
tal_steal(peer->closing_onchain.wscripts,
peer->closing_onchain.wscripts[i]);
log_add(peer->log, "HTLC %"PRIu64,
peer->closing_onchain.htlcs[i]->id);
}
tal_free(hmap);
return true;
fail:
tal_free(hmap);
return false;
}
static bool is_mutual_close(const struct peer *peer,
const struct bitcoin_tx *tx)
{
const u8 *ours, *theirs;
ours = peer->closing.our_script;
theirs = peer->closing.their_script;
/* If we don't know the closing scripts, can't have signed them. */
if (!ours || !theirs)
return false;
if (tx->output_count != 2)
return false;
/* Without knowing fee amounts, can't determine order. Check both. */
if (scripteq(tx->output[0].script, tx->output[0].script_length,
ours, tal_count(ours))
&& scripteq(tx->output[1].script, tx->output[1].script_length,
theirs, tal_count(theirs)))
return true;
if (scripteq(tx->output[0].script, tx->output[0].script_length,
theirs, tal_count(theirs))
&& scripteq(tx->output[1].script, tx->output[1].script_length,
ours, tal_count(ours)))
return true;
return false;
}
/* Create a HTLC refund collection for closing_onchain.tx output out_num. */
static const struct bitcoin_tx *htlc_timeout_tx(const struct peer *peer,
unsigned int out_num)
{
const struct htlc *htlc = peer->closing_onchain.htlcs[out_num];
const u8 *wscript = peer->closing_onchain.wscripts[out_num];
struct bitcoin_tx *tx = bitcoin_tx(peer, 1, 1);
struct bitcoin_signature sig;
u64 fee, satoshis;
/* We must set locktime so HTLC expiry can OP_CHECKLOCKTIMEVERIFY */
tx->lock_time = htlc->expiry.locktime;
tx->input[0].index = out_num;
tx->input[0].txid = peer->closing_onchain.txid;
satoshis = htlc->msatoshis / 1000;
tx->input[0].amount = tal_dup(tx->input, u64, &satoshis);
tx->input[0].sequence_number = bitcoin_nsequence(&peer->remote.locktime);
/* Using a new output address here would be useless: they can tell
* it's our HTLC, and that we collected it via timeout. */
tx->output[0].script = scriptpubkey_p2sh(tx,
bitcoin_redeem_single(tx,
peer->dstate->secpctx,
&peer->local.finalkey));
tx->output[0].script_length = tal_count(tx->output[0].script);
log_unusual(peer->log, "Pre-witness txlen = %zu\n",
measure_tx_cost(tx) / 4);
assert(measure_tx_cost(tx) == 83 * 4);
/* Witness length can vary, due to DER encoding of sigs, but we
* use 539 from an example run. */
/* FIXME: Dynamic fees! */
fee = fee_by_feerate(83 + 539 / 4,
peer->dstate->config.closing_fee_rate);
/* FIXME: Fail gracefully in these cases (not worth collecting) */
if (fee > satoshis || is_dust_amount(satoshis - fee))
fatal("HTLC refund amount of %"PRIu64" won't cover fee %"PRIu64,
satoshis, fee);
tx->output[0].amount = satoshis - fee;
sig.stype = SIGHASH_ALL;
peer_sign_htlc_refund(peer, tx, wscript, &sig.sig);
tx->input[0].witness = bitcoin_witness_htlc(tx, peer->dstate->secpctx,
NULL, &sig, wscript);
log_unusual(peer->log, "tx cost for htlc timeout tx: %zu",
measure_tx_cost(tx));
return tx;
}
static void reset_onchain_closing(struct peer *peer)
{
if (peer->closing_onchain.tx) {
/* FIXME: Log old txid */
log_unusual(peer->log, "New anchor spend, forgetting old");
peer->closing_onchain.tx = tal_free(peer->closing_onchain.tx);
peer->closing_onchain.resolved = NULL;
peer->closing_onchain.htlcs = NULL;
peer->closing_onchain.wscripts = NULL;
}
}
static const struct bitcoin_tx *irrevocably_resolved(struct peer *peer)
{
/* We can't all be irrevocably resolved until the commit tx is,
* so just mark that as resolving us. */
return peer->closing_onchain.tx;
}
/* We've spent an HTLC output to get our funds back. There's still a
* chance that they could also spend the HTLC output (using the preimage),
* so we need to wait for some confirms.
*
* However, we don't want to wait too long: our upstream will get upset if
* their HTLC has timed out and we don't close it. So we wait one less
* than the HTLC timeout difference.
*/
static enum watch_result our_htlc_timeout_depth(struct peer *peer,
unsigned int depth,
const struct sha256_double *txid,
struct htlc *htlc)
{
if (depth == 0)
return KEEP_WATCHING;
if (depth + 1 < peer->dstate->config.min_htlc_expiry)
return KEEP_WATCHING;
our_htlc_failed(peer, htlc);
return DELETE_WATCH;
}
static enum watch_result our_htlc_depth(struct peer *peer,
unsigned int depth,
const struct sha256_double *txid,
enum htlc_side whose_commit,
unsigned int out_num)
{
struct htlc *h = peer->closing_onchain.htlcs[out_num];
u32 height;
/* Must be in a block. */
if (depth == 0)
return KEEP_WATCHING;
height = get_block_height(peer->dstate);
/* BOLT #onchain:
*
* If the *commitment tx* is the other node's, the output is
* considered *timed out* once the HTLC is expired. If the
* *commitment tx* is this node's, the output is considered *timed
* out* once the HTLC is expired, AND the output's
* `OP_CHECKSEQUENCEVERIFY` delay has passed.
*/
if (height < abs_locktime_to_blocks(&h->expiry))
return KEEP_WATCHING;
if (whose_commit == LOCAL) {
if (depth < rel_locktime_to_blocks(&peer->remote.locktime))
return KEEP_WATCHING;
}
/* BOLT #onchain:
*
* If the output has *timed out* and not been *resolved*, the node
* MUST *resolve* the output by spending it.
*/
/* FIXME: we should simply delete this watch if HTLC is fulfilled. */
if (!peer->closing_onchain.resolved[out_num]) {
peer->closing_onchain.resolved[out_num]
= htlc_timeout_tx(peer, out_num);
watch_tx(peer->closing_onchain.resolved[out_num],
peer,
peer->closing_onchain.resolved[out_num],
our_htlc_timeout_depth, h);
broadcast_tx(peer, peer->closing_onchain.resolved[out_num]);
}
return DELETE_WATCH;
}
static enum watch_result our_htlc_depth_theircommit(struct peer *peer,
unsigned int depth,
const struct sha256_double *txid,
ptrint_t *out_num)
{
return our_htlc_depth(peer, depth, txid, REMOTE, ptr2int(out_num));
}
static enum watch_result our_htlc_depth_ourcommit(struct peer *peer,
unsigned int depth,
const struct sha256_double *txid,
ptrint_t *out_num)
{
return our_htlc_depth(peer, depth, txid, LOCAL, ptr2int(out_num));
}
static enum watch_result their_htlc_depth(struct peer *peer,
unsigned int depth,
const struct sha256_double *txid,
ptrint_t *out_num)
{
u32 height;
const struct htlc *htlc = peer->closing_onchain.htlcs[ptr2int(out_num)];
/* Must be in a block. */
if (depth == 0)
return KEEP_WATCHING;
height = get_block_height(peer->dstate);
/* BOLT #onchain:
*
* Otherwise, if the output HTLC has expired, it is considered
* *irrevocably resolved*.
*/
if (height < abs_locktime_to_blocks(&htlc->expiry))
return KEEP_WATCHING;
peer->closing_onchain.resolved[ptr2int(out_num)]
= irrevocably_resolved(peer);
return DELETE_WATCH;
}
static enum watch_result our_main_output_depth(struct peer *peer,
unsigned int depth,
const struct sha256_double *txid,
void *unused)
{
/* Not past CSV timeout? */
if (depth < rel_locktime_to_blocks(&peer->remote.locktime))
return KEEP_WATCHING;
assert(peer->closing_onchain.to_us_idx != -1);
/* BOLT #onchain:
*
* 1. _A's main output_: A node SHOULD spend this output to a
* convenient address. This avoids having to remember the
* complicated witness script associated with that particular
* channel for later spending. ... If the output is spent (as
* recommended), the output is *resolved* by the spending
* transaction
*/
peer->closing_onchain.resolved[peer->closing_onchain.to_us_idx]
= bitcoin_spend_ours(peer);
broadcast_tx(peer, peer->closing_onchain.resolved[peer->closing_onchain.to_us_idx]);
return DELETE_WATCH;
}
/* Any of our HTLCs we didn't have in our commitment tx, but they did,
* we can't fail until we're sure our commitment tx will win. */
static enum watch_result our_unilateral_depth(struct peer *peer,
unsigned int depth,
const struct sha256_double *txid,
void *unused)
{
struct htlc_map_iter it;
struct htlc *h;
if (depth < peer->dstate->config.min_htlc_expiry)
return KEEP_WATCHING;
for (h = htlc_map_first(&peer->htlcs, &it);
h;
h = htlc_map_next(&peer->htlcs, &it)) {
if (htlc_owner(h) == LOCAL
&& !htlc_has(h, HTLC_LOCAL_F_COMMITTED)
&& htlc_has(h, HTLC_REMOTE_F_COMMITTED)) {
log_debug(peer->log,
"%s:failing uncommitted htlc %"PRIu64,
__func__, h->id);
our_htlc_failed(peer, h);
}
}
return DELETE_WATCH;
}
static enum watch_result our_htlc_spent(struct peer *peer,
const struct bitcoin_tx *tx,
size_t input_num,
struct htlc *h)
{
struct sha256 sha;
struct rval preimage;
/* BOLT #onchain:
*
* If a node sees a redemption transaction...the node MUST extract the
* preimage from the transaction input witness. This is either to
* prove payment (if this node originated the payment), or to redeem
* the corresponding incoming HTLC from another peer.
*/
/* This is the form of all HTLC spends. */
if (!tx->input[input_num].witness
|| tal_count(tx->input[input_num].witness) != 3
|| tal_count(tx->input[input_num].witness[1]) != sizeof(preimage))
fatal("Impossible HTLC spend for %"PRIu64, h->id);
/* Our timeout tx has all-zeroes, so we can distinguish it. */
if (memeqzero(tx->input[input_num].witness[1], sizeof(preimage)))
/* They might try to race us. */
return KEEP_WATCHING;
memcpy(&preimage, tx->input[input_num].witness[1], sizeof(preimage));
sha256(&sha, &preimage, sizeof(preimage));
/* FIXME: This could happen with a ripemd collision, since
* script.c only checks that ripemd matches... */
if (!structeq(&sha, &h->rhash))
fatal("HTLC redeemed with incorrect r value?");
log_unusual(peer->log, "Peer redeemed HTLC %"PRIu64" on-chain",
h->id);
log_add_struct(peer->log, " using rvalue %s", struct rval, &preimage);
our_htlc_fulfilled(peer, h, &preimage);
/* BOLT #onchain:
*
* If a node sees a redemption transaction, the output is considered
* *irrevocably resolved*... Note that we don't care about the fate of
* the redemption transaction itself once we've extracted the
* preimage; the knowledge is not revocable.
*/
peer->closing_onchain.resolved[tx->input[input_num].index]
= irrevocably_resolved(peer);
return DELETE_WATCH;
}
static void resolve_our_htlc(struct peer *peer,
unsigned int out_num,
enum watch_result (*cb)(struct peer *peer,
unsigned int depth,
const struct sha256_double*,
ptrint_t *out_num))
{
/* BOLT #onchain:
*
* A node MUST watch for spends of *commitment tx* outputs for HTLCs
* it offered; each one must be *resolved* by a timeout transaction
* (the node pays back to itself) or redemption transaction (the other
* node provides the redemption preimage).
*/
watch_txo(peer->closing_onchain.tx,
peer, &peer->closing_onchain.txid, out_num,
our_htlc_spent,
peer->closing_onchain.htlcs[out_num]);
watch_txid(peer->closing_onchain.tx, peer,
&peer->closing_onchain.txid, cb, int2ptr(out_num));
}
static void resolve_their_htlc(struct peer *peer, unsigned int out_num)
{
/* BOLT #onchain:
*
* If the node ... already knows... a redemption preimage for an
* unresolved *commitment tx* output it was offered, it MUST *resolve*
* the output by spending it using the preimage.
*/
if (peer->closing_onchain.htlcs[out_num]->r) {
peer->closing_onchain.resolved[out_num]
= htlc_fulfill_tx(peer, out_num);
broadcast_tx(peer, peer->closing_onchain.resolved[out_num]);
} else {
/* BOLT #onchain:
*
* Otherwise, if the output HTLC has expired, it is considered
* *irrevocably resolved*.
*/
watch_tx(peer->closing_onchain.tx, peer,
peer->closing_onchain.tx,
their_htlc_depth, int2ptr(out_num));
}
}
/* BOLT #onchain:
*
* When node A sees its own *commitment tx*:
*/
static void resolve_our_unilateral(struct peer *peer)
{
unsigned int i;
const struct bitcoin_tx *tx = peer->closing_onchain.tx;
/* This only works because we always watch for a long time before
* freeing peer, by which time this has resolved. We could create
* resolved[] entries for these uncommitted HTLCs, too. */
watch_tx(tx, peer, tx, our_unilateral_depth, NULL);
for (i = 0; i < tx->output_count; i++) {
/* BOLT #onchain:
*
* 1. _A's main output_: A node SHOULD spend this output to a
* convenient address. ... A node MUST wait until the
* `OP_CHECKSEQUENCEVERIFY` delay has passed (as specified
* by the other node's `open_channel` `delay` field) before
* spending the output.
*/
if (i == peer->closing_onchain.to_us_idx)
watch_tx(tx, peer, tx, our_main_output_depth, NULL);
/* BOLT #onchain:
*
* 2. _B's main output_: No action required, this output is
* considered *resolved* by the *commitment tx*.
*/
else if (i == peer->closing_onchain.to_them_idx)
peer->closing_onchain.resolved[i] = tx;
/* BOLT #onchain:
*
* 3. _A's offered HTLCs_: See On-chain HTLC Handling: Our
* Offers below.
*/
else if (htlc_owner(peer->closing_onchain.htlcs[i]) == LOCAL)
resolve_our_htlc(peer, i, our_htlc_depth_ourcommit);
/* BOLT #onchain:
*
* 4. _B's offered HTLCs_: See On-chain HTLC Handling: Their
* Offers below.
*/
else
resolve_their_htlc(peer, i);
}
}
/* BOLT #onchain:
*
* Similarly, when node A sees a *commitment tx* from B:
*/
static void resolve_their_unilateral(struct peer *peer)
{
unsigned int i;
const struct bitcoin_tx *tx = peer->closing_onchain.tx;
for (i = 0; i < tx->output_count; i++) {
/* BOLT #onchain:
*
* 1. _A's main output_: No action is required; this is a
* simple P2WPKH output. This output is considered
* *resolved* by the *commitment tx*.
*/
if (i == peer->closing_onchain.to_us_idx)
peer->closing_onchain.resolved[i] = tx;
/* BOLT #onchain:
*
* 2. _B's main output_: No action required, this output is
* considered *resolved* by the *commitment tx*.
*/
else if (i == peer->closing_onchain.to_them_idx)
peer->closing_onchain.resolved[i] = tx;
/* BOLT #onchain:
*
* 3. _A's offered HTLCs_: See On-chain HTLC Handling: Our
* Offers below.
*/
else if (htlc_owner(peer->closing_onchain.htlcs[i]) == LOCAL)
resolve_our_htlc(peer, i, our_htlc_depth_theircommit);
/*
* 4. _B's offered HTLCs_: See On-chain HTLC Handling: Their
* Offers below.
*/
else
resolve_their_htlc(peer, i);
}
}
static void resolve_mutual_close(struct peer *peer)
{
unsigned int i;
/* BOLT #onchain:
*
* A node doesn't need to do anything else as it has already agreed to
* the output, which is sent to its specified scriptpubkey (see BOLT
* #2 "4.1: Closing initiation: close_clearing").
*/
for (i = 0; i < peer->closing_onchain.tx->output_count; i++)
peer->closing_onchain.resolved[i] = irrevocably_resolved(peer);
/* No HTLCs. */
peer->closing_onchain.htlcs = tal_arrz(peer->closing_onchain.tx,
struct htlc *,
peer->closing_onchain.tx->output_count);
}
/* Called every time the tx spending the funding tx changes depth. */
static enum watch_result check_for_resolution(struct peer *peer,
unsigned int depth,
const struct sha256_double *txid,
void *unused)
{
size_t i, n = tal_count(peer->closing_onchain.resolved);
size_t forever = peer->dstate->config.forever_confirms;
/* BOLT #onchain:
*
* A node MUST *resolve* all outputs as specified below, and MUST be
* prepared to resolve them multiple times in case of blockchain
* reorganizations.
*/
for (i = 0; i < n; i++)
if (!peer->closing_onchain.resolved[i])
return KEEP_WATCHING;
/* BOLT #onchain:
*
* Outputs which are *resolved* by a transaction are considered
* *irrevocably resolved* once they are included in a block at least
* 100 deep on the most-work blockchain.
*/
if (depth < forever)
return KEEP_WATCHING;
for (i = 0; i < n; i++) {
struct sha256_double txid;
bitcoin_txid(peer->closing_onchain.resolved[i], &txid);
if (get_tx_depth(peer->dstate, &txid) < forever)
return KEEP_WATCHING;
}
/* BOLT #onchain:
*
* A node MUST monitor the blockchain for transactions which spend any
* output which is not *irrevocably resolved* until all outputs are
* *irrevocably resolved*.
*/
set_peer_state(peer, STATE_CLOSED, "check_for_resolution");
/* It's theoretically possible that peer is still writing output */
if (!peer->conn)
io_break(peer);
else
io_wake(peer);
return DELETE_WATCH;
}
static bool find_their_old_tx(struct peer *peer,
const struct sha256_double *txid,
u64 *idx)
{
/* FIXME: Don't keep these in memory, search db here. */
struct their_commit *tc;
log_debug_struct(peer->log, "Finding txid %s", struct sha256_double,
txid);
list_for_each(&peer->their_commits, tc, list) {
if (structeq(&tc->txid, txid)) {
*idx = tc->commit_num;
return true;
}
}
return false;
}
static void resolve_their_steal(struct peer *peer,
const struct sha256 *revocation_preimage)
{
int i, n;
const struct bitcoin_tx *tx = peer->closing_onchain.tx;
struct bitcoin_tx *steal_tx;
size_t wsize = 0;
u64 input_total = 0, fee;
/* Create steal_tx: don't need to steal to_us output */
if (peer->closing_onchain.to_us_idx == -1)
steal_tx = bitcoin_tx(tx, tx->output_count, 1);
else
steal_tx = bitcoin_tx(tx, tx->output_count - 1, 1);
n = 0;
log_debug(peer->log, "Analyzing tx to steal:");
for (i = 0; i < tx->output_count; i++) {
/* BOLT #onchain:
* 1. _A's main output_: No action is required; this is a
* simple P2WPKH output. This output is considered
* *resolved* by the *commitment tx*.
*/
if (i == peer->closing_onchain.to_us_idx) {
log_debug(peer->log, "%i is to-us, ignoring", i);
peer->closing_onchain.resolved[i] = tx;
continue;
}
/* BOLT #onchain:
*
* 2. _B's main output_: The node MUST *resolve* this by
* spending using the revocation preimage.
*
* 3. _A's offered HTLCs_: The node MUST *resolve* this by
* spending using the revocation preimage.
*
* 4. _B's offered HTLCs_: The node MUST *resolve* this by
* spending using the revocation preimage.
*/
peer->closing_onchain.resolved[i] = steal_tx;
/* Connect it up. */
steal_tx->input[n].txid = peer->closing_onchain.txid;
steal_tx->input[n].index = i;
steal_tx->input[n].amount = tal_dup(steal_tx, u64,
&tx->output[i].amount);
/* Track witness size, for fee. */
wsize += tal_count(peer->closing_onchain.wscripts[n]);
input_total += tx->output[i].amount;
n++;
}
assert(n == steal_tx->input_count);
/* FIXME: Dynamic fees! */
fee = peer->dstate->config.closing_fee_rate
* (measure_tx_cost(steal_tx) + wsize) / 1000;
if (fee > input_total || is_dust_amount(input_total - fee)) {
log_unusual(peer->log, "Not worth stealing tiny amount %"PRIu64,
input_total);
/* Consider them all resolved by steal tx. */
for (i = 0; i < tal_count(peer->closing_onchain.resolved); i++)
peer->closing_onchain.resolved[i] = tx;
tal_free(steal_tx);
return;
}
steal_tx->output[0].amount = input_total - fee;
steal_tx->output[0].script = scriptpubkey_p2sh(steal_tx,
bitcoin_redeem_single(steal_tx,
peer->dstate->secpctx,
&peer->local.finalkey));
steal_tx->output[0].script_length = tal_count(steal_tx->output[0].script);
/* Now, we can sign them all (they're all of same form). */
for (i = 0; i < n; i++) {
struct bitcoin_signature sig;
sig.stype = SIGHASH_ALL;
peer_sign_steal_input(peer, steal_tx, i,
peer->closing_onchain.wscripts[i],
&sig.sig);
steal_tx->input[i].witness
= bitcoin_witness_secret(steal_tx,
peer->dstate->secpctx,
revocation_preimage,
sizeof(*revocation_preimage),
&sig,
peer->closing_onchain.wscripts[i]);
}
broadcast_tx(peer, steal_tx);
}
static struct sha256 *get_rhash(struct peer *peer, u64 commit_num,
struct sha256 *rhash)
{
struct sha256 preimage;
/* Previous revoked tx? */
if (shachain_get_hash(&peer->their_preimages,
0xFFFFFFFFFFFFFFFFL - commit_num,
&preimage)) {
sha256(rhash, &preimage, sizeof(preimage));
return tal_dup(peer, struct sha256, &preimage);
}
/* Current tx? */
if (commit_num == peer->remote.commit->commit_num) {
*rhash = peer->remote.commit->revocation_hash;
return NULL;
}
/* Last tx, but we haven't got revoke for it yet? */
assert(commit_num == peer->remote.commit->commit_num-1);
*rhash = *peer->their_prev_revocation_hash;
return NULL;
}
/* We assume the tx is valid! Don't do a blockchain.info and feed this
* invalid transactions! */
static enum watch_result anchor_spent(struct peer *peer,
const struct bitcoin_tx *tx,
size_t input_num,
void *unused)
{
Pkt *err;
enum state newstate;
struct htlc_map_iter it;
struct htlc *h;
u64 commit_num;
assert(input_num < tx->input_count);
/* We only ever sign single-input txs. */
if (input_num != 0) {
log_broken(peer->log, "Anchor spend by non-single input tx");
goto unknown_spend;
}
/* We may have been following a different spend. Forget it. */
reset_onchain_closing(peer);
peer->closing_onchain.tx = tal_steal(peer, tx);
bitcoin_txid(tx, &peer->closing_onchain.txid);
/* If we have any HTLCs we're not committed to yet, fail them now. */
for (h = htlc_map_first(&peer->htlcs, &it);
h;
h = htlc_map_next(&peer->htlcs, &it)) {
if (h->state == SENT_ADD_HTLC) {
our_htlc_failed(peer, h);
}
}
/* We need to resolve every output. */
peer->closing_onchain.resolved
= tal_arrz(tx, const struct bitcoin_tx *, tx->output_count);
/* A mutual close tx. */
if (is_mutual_close(peer, tx)) {
newstate = STATE_CLOSE_ONCHAIN_MUTUAL;
err = NULL;
resolve_mutual_close(peer);
/* Our unilateral */
} else if (structeq(&peer->local.commit->txid,
&peer->closing_onchain.txid)) {
newstate = STATE_CLOSE_ONCHAIN_OUR_UNILATERAL;
/* We're almost certainly closed to them by now. */
err = pkt_err(peer, "Our own unilateral close tx seen");
if (!map_onchain_outputs(peer,
&peer->local.commit->revocation_hash,
tx, LOCAL,
peer->local.commit->commit_num)) {
log_broken(peer->log,
"Can't resolve own anchor spend %"PRIu64"!",
commit_num);
goto unknown_spend;
}
resolve_our_unilateral(peer);
/* Must be their unilateral */
} else if (find_their_old_tx(peer, &peer->closing_onchain.txid,
&commit_num)) {
struct sha256 *preimage, rhash;
preimage = get_rhash(peer, commit_num, &rhash);
if (!map_onchain_outputs(peer, &rhash, tx, REMOTE, commit_num)) {
/* Should not happen */
log_broken(peer->log,
"Can't resolve known anchor spend %"PRIu64"!",
commit_num);
goto unknown_spend;
}
if (preimage) {
newstate = STATE_CLOSE_ONCHAIN_CHEATED;
err = pkt_err(peer, "Revoked transaction seen");
resolve_their_steal(peer, preimage);
} else {
newstate = STATE_CLOSE_ONCHAIN_THEIR_UNILATERAL;
err = pkt_err(peer, "Unilateral close tx seen");
resolve_their_unilateral(peer);
}
} else {
/* FIXME: Log harder! */
log_broken(peer->log,
"Unknown anchor spend! Funds may be lost!");
goto unknown_spend;
}
/* BOLT #onchain:
*
* A node MAY send a descriptive error packet in this case.
*/
if (err && state_can_io(peer->state))
queue_pkt_err(peer, err);
set_peer_state(peer, newstate, "anchor_spent");
/* If we've just closed connection, make output close it. */
io_wake(peer);
/* BOLT #onchain:
*
* A node SHOULD fail the connection if it is not already
* closed when it sees the funding transaction spent.
*/
assert(!state_can_io(peer->state));
assert(peer->closing_onchain.resolved != NULL);
watch_tx(tx, peer, tx, check_for_resolution, NULL);
return KEEP_WATCHING;
unknown_spend:
/* BOLT #onchain:
*
* A node SHOULD report an error to the operator if it
* sees a transaction spend the funding transaction
* output which does not fall into one of these
* categories (mutual close, unilateral close, or
* cheating attempt). Such a transaction implies its
* private key has leaked, and funds may be lost.
*/
set_peer_state(peer, STATE_ERR_INFORMATION_LEAK, "anchor_spent");
return DELETE_WATCH;
}
static void anchor_timeout(struct peer *peer)
{
/* FIXME: We could just forget timeout once we're not opening. */
if (state_is_opening(peer->state))
state_event(peer, BITCOIN_ANCHOR_TIMEOUT, NULL);
}
void peer_watch_anchor(struct peer *peer,
int depth,
enum state_input depthok,
enum state_input timeout)
{
/* We assume this. */
assert(depthok == BITCOIN_ANCHOR_DEPTHOK);
assert(timeout == BITCOIN_ANCHOR_TIMEOUT || timeout == INPUT_NONE);
peer->anchor.ok_depth = depth;
watch_txid(peer, peer, &peer->anchor.txid, anchor_depthchange, NULL);
watch_txo(peer, peer, &peer->anchor.txid, 0, anchor_spent, NULL);
/* For anchor timeout, expect 20 minutes per block, +2 hours.
*
* Probability(no block in time N) = e^(-N/600).
* Thus for 1 block, P = e^(-(7200+1*1200)/600) = 0.83 in a million.
*
* Glenn Willen says, if we want to know how many 10-minute intervals for
* a 1 in a million chance of spurious failure for N blocks, put
* this into http://www.wolframalpha.com:
*
* e^(-x) * sum x^i / fact(i), i=0 to N < 1/1000000
*
* N=20: 51
* N=10: 35
* N=8: 31
* N=6: 28
* N=4: 24
* N=3: 22
* N=2: 20
*
* So, our formula of 12 + N*2 holds for N <= 20 at least.
*/
if (timeout != INPUT_NONE)
new_reltimer(peer->dstate, peer,
time_from_sec(7200 + 20*peer->anchor.ok_depth),
anchor_timeout, peer);
}
struct bitcoin_tx *peer_create_close_tx(struct peer *peer, u64 fee)
{
struct channel_state cstate;
/* We don't need a deep copy here, just fee levels. */
cstate = *peer->local.staging_cstate;
if (!force_fee(&cstate, fee)) {
log_unusual(peer->log,
"peer_create_close_tx: can't afford fee %"PRIu64,
fee);
return NULL;
}
log_debug(peer->log,
"creating close-tx with fee %"PRIu64" amounts %u/%u to ",
fee,
cstate.side[OURS].pay_msat / 1000,
cstate.side[THEIRS].pay_msat / 1000);
log_add_struct(peer->log, "%s", struct pubkey, &peer->local.finalkey);
log_add_struct(peer->log, "/%s", struct pubkey, &peer->remote.finalkey);
return create_close_tx(peer->dstate->secpctx, peer,
peer->closing.our_script,
peer->closing.their_script,
&peer->anchor.txid,
peer->anchor.index,
peer->anchor.satoshis,
cstate.side[OURS].pay_msat / 1000,
cstate.side[THEIRS].pay_msat / 1000);
}
/* Now we can create anchor tx. */
static void got_feerate(struct lightningd_state *dstate,
u64 rate, struct peer *peer)
{
u64 fee;
struct bitcoin_tx *tx = bitcoin_tx(peer, 1, 1);
size_t i;
tx->output[0].script = scriptpubkey_p2wsh(tx, peer->anchor.witnessscript);
tx->output[0].script_length = tal_count(tx->output[0].script);
/* Add input script length. FIXME: This is normal case, not exact. */
fee = fee_by_feerate(measure_tx_cost(tx)/4 + 1+73 + 1+33 + 1, rate);
if (fee >= peer->anchor.input->amount)
/* FIXME: Report an error here!
* We really should set this when they do command, but
* we need to modify state to allow immediate anchor
* creation: using estimate_fee is a convenient workaround. */
fatal("Amount %"PRIu64" below fee %"PRIu64,
peer->anchor.input->amount, fee);
tx->output[0].amount = peer->anchor.input->amount - fee;
tx->input[0].txid = peer->anchor.input->txid;
tx->input[0].index = peer->anchor.input->index;
tx->input[0].amount = tal_dup(tx->input, u64,
&peer->anchor.input->amount);
wallet_add_signed_input(peer->dstate, peer->anchor.input->w, tx, 0);
bitcoin_txid(tx, &peer->anchor.txid);
peer->anchor.tx = tx;
peer->anchor.index = 0;
/* We'll need this later, when we're told to broadcast it. */
peer->anchor.satoshis = tx->output[0].amount;
/* To avoid malleation, all inputs must be segwit! */
for (i = 0; i < tx->input_count; i++)
assert(tx->input[i].witness);
state_event(peer, BITCOIN_ANCHOR_CREATED, NULL);
}
/* Creation the bitcoin anchor tx, spending output user provided. */
void bitcoin_create_anchor(struct peer *peer, enum state_input done)
{
/* We must be offering anchor for us to try creating it */
assert(peer->local.offer_anchor);
assert(done == BITCOIN_ANCHOR_CREATED);
bitcoind_estimate_fee(peer->dstate, got_feerate, peer);
}
/* We didn't end up broadcasting the anchor: we don't need to do anything
* to "release" TXOs, since we have our own internal wallet now. */
void bitcoin_release_anchor(struct peer *peer, enum state_input done)
{
}
/* Get the bitcoin anchor tx. */
const struct bitcoin_tx *bitcoin_anchor(struct peer *peer)
{
return peer->anchor.tx;
}
/* Sets up the initial cstate and commit tx for both nodes: false if
* insufficient funds. */
bool setup_first_commit(struct peer *peer)
{
assert(!peer->local.commit->tx);
assert(!peer->remote.commit->tx);
/* Revocation hashes already filled in, from pkt_open */
peer->local.commit->cstate = initial_cstate(peer,
peer->anchor.satoshis,
peer->local.commit_fee_rate,
peer->local.offer_anchor
== CMD_OPEN_WITH_ANCHOR ?
OURS : THEIRS);
if (!peer->local.commit->cstate)
return false;
peer->remote.commit->cstate = initial_cstate(peer,
peer->anchor.satoshis,
peer->remote.commit_fee_rate,
peer->local.offer_anchor
== CMD_OPEN_WITH_ANCHOR ?
OURS : THEIRS);
if (!peer->remote.commit->cstate)
return false;
peer->local.commit->tx = create_commit_tx(peer->local.commit,
peer,
&peer->local.commit->revocation_hash,
peer->local.commit->cstate,
LOCAL);
bitcoin_txid(peer->local.commit->tx, &peer->local.commit->txid);
peer->remote.commit->tx = create_commit_tx(peer->remote.commit,
peer,
&peer->remote.commit->revocation_hash,
peer->remote.commit->cstate,
REMOTE);
bitcoin_txid(peer->remote.commit->tx, &peer->remote.commit->txid);
peer->local.staging_cstate = copy_cstate(peer, peer->local.commit->cstate);
peer->remote.staging_cstate = copy_cstate(peer, peer->remote.commit->cstate);
return true;
}
static void json_add_abstime(struct json_result *response,
const char *id,
const struct abs_locktime *t)
{
json_object_start(response, id);
if (abs_locktime_is_seconds(t))
json_add_num(response, "second", abs_locktime_to_seconds(t));
else
json_add_num(response, "block", abs_locktime_to_blocks(t));
json_object_end(response);
}
static void json_add_pubkey(struct json_result *response,
secp256k1_context *secpctx,
const char *id,
const struct pubkey *key)
{
u8 der[PUBKEY_DER_LEN];
pubkey_to_der(secpctx, der, key);
json_add_hex(response, id, der, sizeof(der));
}
static void json_add_htlcs(struct json_result *response,
const char *id,
struct peer *peer,
enum htlc_side owner)
{
struct htlc_map_iter it;
struct htlc *h;
const struct htlc_map *htlcs = &peer->htlcs;
json_array_start(response, id);
for (h = htlc_map_first(htlcs, &it); h; h = htlc_map_next(htlcs, &it)) {
if (htlc_owner(h) != owner)
continue;
/* Ignore completed HTLCs. */
if (h->state == RCVD_REMOVE_ACK_REVOCATION
|| h->state == SENT_REMOVE_ACK_REVOCATION)
continue;
json_object_start(response, NULL);
json_add_u64(response, "msatoshis", h->msatoshis);
json_add_abstime(response, "expiry", &h->expiry);
json_add_hex(response, "rhash", &h->rhash, sizeof(h->rhash));
json_add_string(response, "state", htlc_state_name(h->state));
json_object_end(response);
}
json_array_end(response);
}
/* FIXME: add history command which shows all prior and current commit txs */
/* FIXME: Somehow we should show running DNS lookups! */
static void json_getpeers(struct command *cmd,
const char *buffer, const jsmntok_t *params)
{
struct peer *p;
struct json_result *response = new_json_result(cmd);
json_object_start(response, NULL);
json_array_start(response, "peers");
list_for_each(&cmd->dstate->peers, p, list) {
const struct channel_state *last;
json_object_start(response, NULL);
json_add_string(response, "name", log_prefix(p->log));
json_add_string(response, "state", state_name(p->state));
if (p->id)
json_add_pubkey(response, cmd->dstate->secpctx,
"peerid", p->id);
json_add_bool(response, "connected", p->conn && !p->fake_close);
/* FIXME: Report anchor. */
if (!p->local.commit || !p->local.commit->cstate) {
json_object_end(response);
continue;
}
last = p->local.commit->cstate;
json_add_num(response, "our_amount", last->side[OURS].pay_msat);
json_add_num(response, "our_fee", last->side[OURS].fee_msat);
json_add_num(response, "their_amount", last->side[THEIRS].pay_msat);
json_add_num(response, "their_fee", last->side[THEIRS].fee_msat);
json_add_htlcs(response, "our_htlcs", p, LOCAL);
json_add_htlcs(response, "their_htlcs", p, REMOTE);
json_object_end(response);
}
json_array_end(response);
json_object_end(response);
command_success(cmd, response);
}
const struct json_command getpeers_command = {
"getpeers",
json_getpeers,
"List the current peers",
"Returns a 'peers' array"
};
/* To avoid freeing underneath ourselves, we free outside event loop. */
void cleanup_peers(struct lightningd_state *dstate)
{
struct peer *peer, *next;
list_for_each_safe(&dstate->peers, peer, next, list) {
/* Deletes itself from list. */
if (!peer->conn && peer->state == STATE_CLOSED)
tal_free(peer);
}
}
/* A zero-fee single route to this peer. */
static const u8 *dummy_single_route(const tal_t *ctx,
const struct peer *peer,
u64 msatoshis)
{
struct node_connection **path = tal_arr(ctx, struct node_connection *, 0);
return onion_create(ctx, peer->dstate->secpctx, path, msatoshis, 0);
}
static void json_newhtlc(struct command *cmd,
const char *buffer, const jsmntok_t *params)
{
struct peer *peer;
jsmntok_t *peeridtok, *msatoshistok, *expirytok, *rhashtok;
unsigned int expiry;
u64 msatoshis;
struct sha256 rhash;
struct json_result *response = new_json_result(cmd);
struct htlc *htlc;
if (!json_get_params(buffer, params,
"peerid", &peeridtok,
"msatoshis", &msatoshistok,
"expiry", &expirytok,
"rhash", &rhashtok,
NULL)) {
command_fail(cmd, "Need peerid, msatoshis, expiry and rhash");
return;
}
peer = find_peer_json(cmd->dstate, buffer, peeridtok);
if (!peer) {
command_fail(cmd, "Could not find peer with that peerid");
return;
}
if (!peer->remote.commit || !peer->remote.commit->cstate) {
command_fail(cmd, "peer not fully established");
return;
}
if (!json_tok_u64(buffer, msatoshistok, &msatoshis)) {
command_fail(cmd, "'%.*s' is not a valid number",
(int)(msatoshistok->end - msatoshistok->start),
buffer + msatoshistok->start);
return;
}
if (!json_tok_number(buffer, expirytok, &expiry)) {
command_fail(cmd, "'%.*s' is not a valid number",
(int)(expirytok->end - expirytok->start),
buffer + expirytok->start);
return;
}
if (!hex_decode(buffer + rhashtok->start,
rhashtok->end - rhashtok->start,
&rhash, sizeof(rhash))) {
command_fail(cmd, "'%.*s' is not a valid sha256 hash",
(int)(rhashtok->end - rhashtok->start),
buffer + rhashtok->start);
return;
}
htlc = command_htlc_add(peer, msatoshis, expiry, &rhash, NULL,
dummy_single_route(cmd, peer, msatoshis));
if (!htlc) {
command_fail(cmd, "could not add htlc");
return;
}
json_object_start(response, NULL);
json_add_u64(response, "id", htlc->id);
json_object_end(response);
command_success(cmd, response);
}
/* FIXME: Use HTLC ids, not r values! */
const struct json_command newhtlc_command = {
"newhtlc",
json_newhtlc,
"Offer {peerid} an HTLC worth {msatoshis} in {expiry} (block number) with {rhash}",
"Returns { id: u64 } result on success"
};
static void json_fulfillhtlc(struct command *cmd,
const char *buffer, const jsmntok_t *params)
{
struct peer *peer;
jsmntok_t *peeridtok, *idtok, *rtok;
u64 id;
struct htlc *htlc;
struct sha256 rhash;
struct rval r;
if (!json_get_params(buffer, params,
"peerid", &peeridtok,
"id", &idtok,
"r", &rtok,
NULL)) {
command_fail(cmd, "Need peerid, id and r");
return;
}
peer = find_peer_json(cmd->dstate, buffer, peeridtok);
if (!peer) {
command_fail(cmd, "Could not find peer with that peerid");
return;
}
if (!peer->remote.commit || !peer->remote.commit->cstate) {
command_fail(cmd, "peer not fully established");
return;
}
if (!json_tok_u64(buffer, idtok, &id)) {
command_fail(cmd, "'%.*s' is not a valid id",
(int)(idtok->end - idtok->start),
buffer + idtok->start);
return;
}
if (!hex_decode(buffer + rtok->start,
rtok->end - rtok->start,
&r, sizeof(r))) {
command_fail(cmd, "'%.*s' is not a valid sha256 preimage",
(int)(rtok->end - rtok->start),
buffer + rtok->start);
return;
}
htlc = htlc_get(&peer->htlcs, id, REMOTE);
if (!htlc) {
command_fail(cmd, "preimage htlc not found");
return;
}
if (htlc->state != RCVD_ADD_ACK_REVOCATION) {
command_fail(cmd, "htlc in state %s",
htlc_state_name(htlc->state));
return;
}
sha256(&rhash, &r, sizeof(r));
if (!structeq(&htlc->rhash, &rhash)) {
command_fail(cmd, "preimage incorrect");
return;
}
assert(!htlc->r);
htlc->r = tal_dup(htlc, struct rval, &r);
if (command_htlc_fulfill(peer, htlc))
command_success(cmd, null_response(cmd));
else
command_fail(cmd,
"htlc_fulfill not possible in state %s",
state_name(peer->state));
}
const struct json_command fulfillhtlc_command = {
"fulfillhtlc",
json_fulfillhtlc,
"Redeem htlc proposed by {peerid} of {id} using {r}",
"Returns an empty result on success"
};
static void json_failhtlc(struct command *cmd,
const char *buffer, const jsmntok_t *params)
{
struct peer *peer;
jsmntok_t *peeridtok, *idtok;
u64 id;
struct htlc *htlc;
if (!json_get_params(buffer, params,
"peerid", &peeridtok,
"id", &idtok,
NULL)) {
command_fail(cmd, "Need peerid and id");
return;
}
peer = find_peer_json(cmd->dstate, buffer, peeridtok);
if (!peer) {
command_fail(cmd, "Could not find peer with that peerid");
return;
}
if (!peer->remote.commit || !peer->remote.commit->cstate) {
command_fail(cmd, "peer not fully established");
return;
}
if (!json_tok_u64(buffer, idtok, &id)) {
command_fail(cmd, "'%.*s' is not a valid id",
(int)(idtok->end - idtok->start),
buffer + idtok->start);
return;
}
htlc = htlc_get(&peer->htlcs, id, REMOTE);
if (!htlc) {
command_fail(cmd, "preimage htlc not found");
return;
}
if (htlc->state != RCVD_ADD_ACK_REVOCATION) {
command_fail(cmd, "htlc in state %s",
htlc_state_name(htlc->state));
return;
}
if (command_htlc_fail(peer, htlc))
command_success(cmd, null_response(cmd));
else
command_fail(cmd,
"htlc_fail not possible in state %s",
state_name(peer->state));
}
const struct json_command failhtlc_command = {
"failhtlc",
json_failhtlc,
"Fail htlc proposed by {peerid} which has {id}",
"Returns an empty result on success"
};
static void json_commit(struct command *cmd,
const char *buffer, const jsmntok_t *params)
{
struct peer *peer;
jsmntok_t *peeridtok;
if (!json_get_params(buffer, params,
"peerid", &peeridtok,
NULL)) {
command_fail(cmd, "Need peerid");
return;
}
peer = find_peer_json(cmd->dstate, buffer, peeridtok);
if (!peer) {
command_fail(cmd, "Could not find peer with that peerid");
return;
}
if (!peer->remote.commit || !peer->remote.commit->cstate) {
command_fail(cmd, "peer not fully established");
return;
}
if (!state_can_commit(peer->state)) {
command_fail(cmd, "peer in state %s", state_name(peer->state));
return;
}
do_commit(peer, cmd);
}
const struct json_command commit_command = {
"commit",
json_commit,
"Commit all staged HTLC changes with {peerid}",
"Returns an empty result on success"
};
static void json_close(struct command *cmd,
const char *buffer, const jsmntok_t *params)
{
struct peer *peer;
jsmntok_t *peeridtok;
if (!json_get_params(buffer, params,
"peerid", &peeridtok,
NULL)) {
command_fail(cmd, "Need peerid");
return;
}
peer = find_peer_json(cmd->dstate, buffer, peeridtok);
if (!peer) {
command_fail(cmd, "Could not find peer with that peerid");
return;
}
if (!state_is_normal(peer->state) && !state_is_opening(peer->state)) {
command_fail(cmd, "Peer is already closing: state %s",
state_name(peer->state));
return;
}
if (peer->state == STATE_NORMAL_COMMITTING)
set_peer_state(peer, STATE_CLEARING_COMMITTING, __func__);
else
set_peer_state(peer, STATE_CLEARING, __func__);
peer_start_clearing(peer);
command_success(cmd, null_response(cmd));
}
const struct json_command close_command = {
"close",
json_close,
"Close the channel with peer {peerid}",
"Returns an empty result on success"
};
static void json_disconnect(struct command *cmd,
const char *buffer, const jsmntok_t *params)
{
struct peer *peer;
jsmntok_t *peeridtok;
if (!json_get_params(buffer, params,
"peerid", &peeridtok,
NULL)) {
command_fail(cmd, "Need peerid");
return;
}
peer = find_peer_json(cmd->dstate, buffer, peeridtok);
if (!peer) {
command_fail(cmd, "Could not find peer with that peerid");
return;
}
if (!peer->conn) {
command_fail(cmd, "Peer is already disconnected");
return;
}
/* We don't actually close it, since for testing we want only
* one side to freak out. We just ensure we ignore it. */
log_debug(peer->log, "Pretending connection is closed");
peer->fake_close = true;
set_peer_state(peer, STATE_ERR_BREAKDOWN, "json_disconnect");
peer_breakdown(peer);
command_success(cmd, null_response(cmd));
}
static void json_signcommit(struct command *cmd,
const char *buffer, const jsmntok_t *params)
{
struct peer *peer;
jsmntok_t *peeridtok;
u8 *linear;
const struct bitcoin_tx *tx;
struct json_result *response = new_json_result(cmd);
if (!json_get_params(buffer, params,
"peerid", &peeridtok,
NULL)) {
command_fail(cmd, "Need peerid");
return;
}
peer = find_peer_json(cmd->dstate, buffer, peeridtok);
if (!peer) {
command_fail(cmd, "Could not find peer with that peerid");
return;
}
if (!peer->local.commit->sig) {
command_fail(cmd, "Peer has not given us a signature");
return;
}
tx = bitcoin_commit(peer);
linear = linearize_tx(cmd, tx);
/* Clear witness for potential future uses. */
tx->input[0].witness = tal_free(tx->input[0].witness);
json_object_start(response, NULL);
json_add_string(response, "tx",
tal_hexstr(cmd, linear, tal_count(linear)));
json_object_end(response);
command_success(cmd, response);
}
static void json_output(struct command *cmd,
const char *buffer, const jsmntok_t *params)
{
struct peer *peer;
jsmntok_t *peeridtok, *enabletok;
bool enable;
if (!json_get_params(buffer, params,
"peerid", &peeridtok,
"enable", &enabletok,
NULL)) {
command_fail(cmd, "Need peerid and enable");
return;
}
peer = find_peer_json(cmd->dstate, buffer, peeridtok);
if (!peer) {
command_fail(cmd, "Could not find peer with that peerid");
return;
}
if (!peer->conn) {
command_fail(cmd, "Peer is already disconnected");
return;
}
if (!json_tok_bool(buffer, enabletok, &enable)) {
command_fail(cmd, "enable must be true or false");
return;
}
log_debug(peer->log, "dev-output: output %s",
enable ? "enabled" : "disabled");
peer->output_enabled = enable;
/* Flush any outstanding output */
if (peer->output_enabled)
io_wake(peer);
command_success(cmd, null_response(cmd));
}
const struct json_command output_command = {
"dev-output",
json_output,
"Enable/disable any messages to peer {peerid} depending on {enable}",
"Returns an empty result on success"
};
const struct json_command disconnect_command = {
"dev-disconnect",
json_disconnect,
"Force a disconned with peer {peerid}",
"Returns an empty result on success"
};
const struct json_command signcommit_command = {
"dev-signcommit",
json_signcommit,
"Sign and return the current commit with peer {peerid}",
"Returns a hex string on success"
};