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lightning/daemon/peer.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 "peer.h"
#include "permute_tx.h"
#include "protobuf_convert.h"
#include "pseudorand.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>
#define FIXME_STUB(peer) do { log_broken((peer)->dstate->base_log, "%s:%u: Implement %s!", __FILE__, __LINE__, __func__); abort(); } while(0)
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 struct peer *find_peer(struct lightningd_state *dstate,
const char *buffer,
jsmntok_t *peeridtok)
{
struct pubkey peerid;
struct peer *peer;
if (!pubkey_from_hexstr(dstate->secpctx,
buffer + peeridtok->start,
peeridtok->end - peeridtok->start, &peerid))
return NULL;
list_for_each(&dstate->peers, peer, list) {
if (peer->state != STATE_INIT && pubkey_eq(&peer->id, &peerid))
return peer;
}
return NULL;
}
static struct json_result *null_response(const tal_t *ctx)
{
struct json_result *response;
response = new_json_result(ctx);
json_object_start(response, NULL);
json_object_end(response);
return response;
}
/* FIXME: reorder to avoid predecls. */
static bool peer_uncommitted_changes(const struct peer *peer);
static void state_event(struct peer *peer,
const enum state_input input,
const union input *idata);
void peer_update_complete(struct peer *peer, const char *problem)
{
if (!problem) {
log_debug(peer->log, "peer_update_complete");
if (peer->commit_jsoncmd)
command_success(peer->commit_jsoncmd,
null_response(peer->commit_jsoncmd));
} else {
log_unusual(peer->log, "peer_update_complete failed: %s",
problem);
if (peer->commit_jsoncmd)
command_fail(peer->commit_jsoncmd, "%s", problem);
}
/* Simply unset it: it will free itself. */
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
log_debug(peer->log, "peer open complete");
}
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;
}
/* FIXME: Flatten into do_commit. */
static void command_send_commit(struct peer *peer, struct command *jsoncmd)
{
assert(state_can_commit(peer->state));
assert(!peer->commit_jsoncmd);
peer->commit_jsoncmd = jsoncmd;
if (peer->state == STATE_CLEARING) {
queue_pkt_commit(peer);
set_peer_state(peer, STATE_CLEARING_COMMITTING, __func__);
} else {
/* You can send commands if closing; peer->cond == CLOSING */
assert(peer->state == STATE_NORMAL);
state_event(peer, CMD_SEND_COMMIT, NULL);
}
}
static bool command_htlc_fail(struct peer *peer, u64 id, struct command *jsoncmd)
{
if (!state_can_remove_htlc(peer->state)) {
if (jsoncmd)
command_fail(jsoncmd,
"htlc_fail not possible in state %s",
state_name(peer->state));
return false;
}
if (peer->state == STATE_CLEARING) {
queue_pkt_htlc_fail(peer, id);
} else {
union input idata;
struct htlc_progress prog;
prog.stage.fail.fail = HTLC_FAIL;
prog.stage.fail.id = id;
/* FIXME: get rid of htlc_progress, just use htlc_staging. */
idata.htlc_prog = &prog;
state_event(peer, CMD_SEND_HTLC_FAIL, &idata);
}
if (jsoncmd)
command_success(jsoncmd, null_response(jsoncmd));
return true;
}
/* FIXME: Flatten into json_fulfillhtlc. */
static bool command_htlc_fulfill(struct peer *peer,
u64 id,
const struct sha256 *r,
struct command *jsoncmd)
{
if (!state_can_remove_htlc(peer->state)) {
if (jsoncmd)
command_fail(jsoncmd,
"htlc_fulfill not possible in state %s",
state_name(peer->state));
return false;
}
/* Commands should still be blocked during this! */
assert(peer->state != STATE_CLEARING_COMMITTING);
if (peer->state == STATE_CLEARING) {
queue_pkt_htlc_fulfill(peer, id, r);
} else {
union input idata;
struct htlc_progress prog;
prog.stage.fulfill.fulfill = HTLC_FULFILL;
prog.stage.fulfill.r = *r;
prog.stage.fulfill.id = id;
/* FIXME: get rid of htlc_progress, just use htlc_staging. */
idata.htlc_prog = &prog;
state_event(peer, CMD_SEND_HTLC_FULFILL, &idata);
}
if (jsoncmd)
command_success(jsoncmd, null_response(jsoncmd));
return true;
}
static void peer_breakdown(struct peer *peer)
{
/* 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);
}
}
static bool peer_uncommitted_changes(const struct peer *peer)
{
/* Not initialized yet? */
if (!peer->remote.staging_cstate
|| !peer->remote.commit
|| !peer->remote.commit->cstate)
return false;
/* We could have proposed changes to their commit */
return peer->remote.staging_cstate->changes
!= peer->remote.commit->cstate->changes;
}
/* All unrevoked commit txs must have no HTLCs in them. */
static bool committed_to_htlcs(const struct peer *peer)
{
const struct commit_info *i;
/* Before anchor exchange, we don't even have cstate. */
if (!peer->local.commit || !peer->local.commit->cstate)
return false;
i = peer->local.commit;
while (i && !i->revocation_preimage) {
if (tal_count(i->cstate->side[OURS].htlcs))
return true;
if (tal_count(i->cstate->side[THEIRS].htlcs))
return true;
i = i->prev;
}
i = peer->remote.commit;
while (i && !i->revocation_preimage) {
if (tal_count(i->cstate->side[OURS].htlcs))
return true;
if (tal_count(i->cstate->side[THEIRS].htlcs))
return true;
i = i->prev;
}
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 struct io_plan *peer_comms_err(struct io_conn *conn, struct peer *peer,
Pkt *err)
{
if (err)
queue_pkt_err(peer, err);
set_peer_state(peer, STATE_ERR_BREAKDOWN, __func__);
peer_breakdown(peer);
return peer_close(conn, peer);
}
/* Unexpected packet received: stop listening, start breakdown procedure. */
static struct io_plan *peer_received_unexpected_pkt(struct io_conn *conn,
struct peer *peer,
const Pkt *pkt)
{
peer_unexpected_pkt(peer, pkt);
return peer_comms_err(conn, peer, pkt_err_unexpected(peer, pkt));
}
/* This is the io loop while we're negotiating closing tx. */
static struct io_plan *closing_pkt_in(struct io_conn *conn, struct peer *peer)
{
const CloseSignature *c = peer->inpkt->close_signature;
struct bitcoin_tx *close_tx;
struct bitcoin_signature theirsig;
assert(peer->state == STATE_MUTUAL_CLOSING);
if (peer->inpkt->pkt_case != PKT__PKT_CLOSE_SIGNATURE)
return peer_received_unexpected_pkt(conn, peer, peer->inpkt);
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(conn, 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(conn, peer,
pkt_err(peer, "Didn't increase close fee"));
} else {
if (c->close_fee >= peer->closing.their_fee)
return peer_comms_err(conn, 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(c->sig, &theirsig.sig))
return peer_comms_err(conn, 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(conn, 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 peer_close(conn, peer);
}
/* FIXME: Dynamic fee! */
return peer_read_packet(conn, peer, closing_pkt_in);
}
/* This is the io loop while we're clearing. */
static struct io_plan *clearing_pkt_in(struct io_conn *conn, struct peer *peer)
{
Pkt *err = NULL, *pkt = peer->inpkt;
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 = accept_pkt_revocation(peer, pkt);
if (!err) {
set_peer_state(peer, STATE_CLEARING, __func__);
peer_update_complete(peer, NULL);
} else
peer_update_complete(peer, "bad revocation");
}
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 = accept_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 = accept_pkt_htlc_fulfill(peer, pkt);
break;
case PKT__PKT_UPDATE_FAIL_HTLC:
err = accept_pkt_htlc_fail(peer, pkt);
break;
case PKT__PKT_UPDATE_COMMIT:
err = accept_pkt_commit(peer, pkt);
if (!err)
queue_pkt_revocation(peer);
break;
case PKT__PKT_ERROR:
peer_unexpected_pkt(peer, pkt);
return peer_comms_err(conn, 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(conn, 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 peer_read_packet(conn, peer, closing_pkt_in);
}
return peer_read_packet(conn, peer, clearing_pkt_in);
}
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->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);
}
}
static void state_single(struct peer *peer,
const enum state_input input,
const union input *idata)
{
const struct bitcoin_tx *broadcast;
enum state newstate;
size_t old_outpkts = tal_count(peer->outpkt);
newstate = state(peer, input, idata, &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 (peer->state == STATE_CLEARING
|| peer->state == STATE_CLEARING_COMMITTING) {
peer_start_clearing(peer);
} else 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);
}
/* Break out and free this peer if it's completely done. */
if (peer->state == STATE_CLOSED && !peer->conn)
io_break(peer);
}
static void state_event(struct peer *peer,
const enum state_input input,
const union input *idata)
{
if (!state_is_opening(peer->state) && !state_is_normal(peer->state)) {
log_unusual(peer->log,
"Unexpected input %s while state %s",
input_name(input), state_name(peer->state));
} else {
state_single(peer, input, idata);
}
}
static struct io_plan *pkt_out(struct io_conn *conn, struct peer *peer)
{
Pkt *out;
size_t n = tal_count(peer->outpkt);
if (peer->fake_close || !peer->output_enabled)
return io_out_wait(conn, peer, pkt_out, peer);
if (n == 0) {
/* We close the connection once we've sent everything. */
if (!state_can_io(peer->state))
return io_close(conn);
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)
{
union input idata;
const tal_t *ctx;
/* Did something move us into STATE_CLEARING? */
if (peer->state == STATE_CLEARING
|| peer->state == STATE_CLEARING_COMMITTING)
return clearing_pkt_in(conn, peer);
else if (peer->state == STATE_MUTUAL_CLOSING)
return closing_pkt_in(conn, peer);
ctx = tal(peer, char);
idata.pkt = tal_steal(ctx, peer->inpkt);
/* We ignore packets if they tell us to. */
if (!peer->fake_close && state_can_io(peer->state)) {
state_event(peer, peer->inpkt->pkt_case, &idata);
}
/* Free peer->inpkt unless stolen above. */
tal_free(ctx);
return peer_read_packet(conn, peer, pkt_in);
}
/* 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)
{
/* We can have changes we suggested, or changes they suggested. */
if (peer_uncommitted_changes(peer)) {
log_debug(peer->log, "do_commit: sending commit command");
command_send_commit(peer, jsoncmd);
return;
}
log_debug(peer->log, "do_commit: no changes to commit");
if (jsoncmd) {
command_fail(jsoncmd, "no changes to commit");
return;
}
}
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);
}
}
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 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->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);
peer->close_watch_timeout = NULL;
peer->anchor.watches = NULL;
peer->cur_commit.watch = NULL;
peer->closing.their_sig = NULL;
peer->closing.our_script = NULL;
peer->closing.their_script = NULL;
peer->cleared = INPUT_NONE;
peer->closing_onchain.tx = NULL;
peer->closing_onchain.resolved = NULL;
peer->closing_onchain.ci = NULL;
peer->commit_timer = 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 (!seconds_to_rel_locktime(dstate->config.rel_locktime,
&peer->local.locktime))
fatal("Invalid locktime configuration %u",
dstate->config.rel_locktime);
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;
/* 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;
}
static struct io_plan *peer_connected_out(struct io_conn *conn,
struct lightningd_state *dstate,
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);
}
log_info(peer->log, "Connected out to %s:%s",
connect->name, connect->port);
peer->anchor.input = tal_steal(peer, connect->input);
command_success(connect->cmd, null_response(connect));
return peer_crypto_setup(conn, peer, peer_crypto_on);
}
static struct io_plan *peer_connected_in(struct io_conn *conn,
struct lightningd_state *dstate)
{
struct peer *peer = new_peer(dstate, conn, SOCK_STREAM, IPPROTO_TCP,
CMD_OPEN_WITHOUT_ANCHOR, "in");
if (!peer)
return io_close(conn);
log_info(peer->log, "Peer connected in");
return peer_crypto_setup(conn, peer, peer_crypto_on);
}
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 || bind(fd, addr, len) == 0) {
if (listen(fd, 5) == 0)
return fd;
log_unusual(dstate->base_log,
"Failed to listen on %u socket: %s",
domain, strerror(errno));
} else
log_debug(dstate->base_log, "Failed to bind on %u socket: %s",
domain, strerror(errno));
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;
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = INADDR_ANY;
addr.sin_port = htons(portnum);
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"
};
struct anchor_watch {
struct peer *peer;
enum state_input depthok;
enum state_input timeout;
/* If timeout != INPUT_NONE, this is the timer. */
struct oneshot *timer;
};
static void anchor_depthchange(struct peer *peer, unsigned int depth,
const struct sha256_double *txid,
void *unused)
{
struct anchor_watch *w = peer->anchor.watches;
/* Still waiting for it to reach depth? */
if (w->depthok != INPUT_NONE) {
if (depth >= peer->local.mindepth) {
enum state_input in = w->depthok;
w->depthok = INPUT_NONE;
/* We don't need the timeout timer any more. */
w->timer = tal_free(w->timer);
state_event(peer, in, NULL);
}
} else if (depth == 0)
/* FIXME: Report losses! */
fatal("Funding transaction was unspent!");
}
/* Yay, segwit! We can just compare txids, even though we don't have both
* signatures. */
static bool txidmatch(const struct bitcoin_tx *tx,
const struct sha256_double *txid)
{
struct sha256_double tx_txid;
bitcoin_txid(tx, &tx_txid);
return structeq(txid, &tx_txid);
}
static struct commit_info *find_commit(struct commit_info *ci,
const struct sha256_double *txid)
{
while (ci) {
if (txidmatch(ci->tx, txid))
return ci;
ci = ci->prev;
}
return NULL;
}
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;
}
static struct channel_htlc *htlc_by_index(const struct commit_info *ci,
size_t index)
{
if (ci->map[index] == -1)
return NULL;
/* First two are non-HTLC outputs to us, them. */
assert(index >= 2);
index -= 2;
if (index < tal_count(ci->cstate->side[OURS].htlcs))
return cast_const(struct channel_htlc *,
ci->cstate->side[OURS].htlcs)
+ index;
index -= tal_count(ci->cstate->side[OURS].htlcs);
assert(index < tal_count(ci->cstate->side[THEIRS].htlcs));
return cast_const(struct channel_htlc *, ci->cstate->side[THEIRS].htlcs)
+ index;
}
static bool htlc_is_ours(const struct commit_info *ci, size_t index)
{
assert(index >= 2);
index -= 2;
return index < tal_count(ci->cstate->side[OURS].htlcs);
}
/* Create a HTLC refund collection */
static const struct bitcoin_tx *htlc_timeout_tx(const struct peer *peer,
const struct commit_info *ci,
unsigned int i)
{
u8 *wscript;
struct channel_htlc *htlc;
struct bitcoin_tx *tx = bitcoin_tx(peer, 1, 1);
struct bitcoin_signature sig;
u64 fee, satoshis;
htlc = htlc_by_index(ci, i);
wscript = bitcoin_redeem_htlc_send(peer,
&peer->local.finalkey,
&peer->remote.finalkey,
&htlc->expiry,
&peer->remote.locktime,
&ci->revocation_hash,
&htlc->rhash);
/* We must set locktime so HTLC expiry can OP_CHECKLOCKTIMEVERIFY */
tx->lock_time = htlc->expiry.locktime;
tx->input[0].index = 0;
bitcoin_txid(ci->tx, &tx->input[0].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->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, 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.ci = 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;
}
static void connect_input(const struct commit_info *ci,
struct bitcoin_tx_input *input,
u32 index)
{
bitcoin_txid(ci->tx, &input->txid);
input->index = index;
input->amount = tal_dup(ci, u64, &ci->tx->output[index].amount);
}
static void resolve_cheating(struct peer *peer)
{
const struct bitcoin_tx *tx = peer->closing_onchain.tx;
const struct commit_info *ci = peer->closing_onchain.ci;
struct bitcoin_tx *steal_tx;
u8 **wscripts;
size_t i, n, num_to_steal;
int *map;
peer->closing_onchain.resolved
= tal_arrz(tx, const struct bitcoin_tx *, tal_count(ci->map));
/* BOLT #onchain:
*
* If a node sees a *commitment tx* for which it has a revocation
* preimage, it *resolves* the funding transaction output:
*
* 1. _A's main output_: No action is required; this is a
* simple P2WPKH output. This output is considered
* *resolved* by the *commitment tx*.
*/
/* Their commit tx, so our output is [1], theirs in [0]. */
peer->closing_onchain.resolved[1] = tx;
/* 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. */
num_to_steal = 0;
if (ci->map[0] == -1)
peer->closing_onchain.resolved[0] = tx;
else
num_to_steal++;
for (i = 2; i < tal_count(ci->map); i++)
if (ci->map[i] == -1)
peer->closing_onchain.resolved[i] = tx;
else
num_to_steal++;
/* Nothing to steal? */
if (num_to_steal == 0)
return;
/* BOLT #onchain:
*
* The node MAY use a single transaction to *resolve* all the
* outputs; due to the 450 HTLC-per-party limit (See BOLT #2:
* 3.2. Adding an HTLC) this can be done within a standard
* transaction.
*/
steal_tx = bitcoin_tx(peer, num_to_steal, 1);
wscripts = tal_arr(steal_tx, u8 *, num_to_steal);
n = 0;
if (ci->map[0] != -1) {
connect_input(ci, &steal_tx->input[n], ci->map[0]);
peer->closing_onchain.resolved[0] = steal_tx;
wscripts[n++]
= bitcoin_redeem_secret_or_delay(wscripts,
&peer->remote.finalkey,
&peer->local.locktime,
&peer->local.finalkey,
&ci->revocation_hash);
}
for (i = 2; i < tal_count(ci->map); i++) {
struct channel_htlc *h;
if (ci->map[i] == -1)
continue;
peer->closing_onchain.resolved[i] = steal_tx;
connect_input(ci, &steal_tx->input[n], ci->map[i]);
h = htlc_by_index(ci, i);
if (!htlc_is_ours(ci, i)) {
wscripts[n]
= bitcoin_redeem_htlc_send(wscripts,
&peer->remote.finalkey,
&peer->local.finalkey,
&h->expiry,
&peer->local.locktime,
&ci->revocation_hash,
&h->rhash);
} else {
wscripts[n]
= bitcoin_redeem_htlc_recv(wscripts,
&peer->remote.finalkey,
&peer->local.finalkey,
&h->expiry,
&peer->local.locktime,
&ci->revocation_hash,
&h->rhash);
}
n++;
}
assert(n == num_to_steal);
/* This obscures the order in which HTLCs were received, at least. */
map = tal_arr(steal_tx, int, num_to_steal);
permute_inputs(steal_tx->input, steal_tx->input_count, map);
/* Now, we can sign them all (they're all of same form). */
for (n = 0; n < num_to_steal; n++) {
struct bitcoin_signature sig;
sig.stype = SIGHASH_ALL;
peer_sign_steal_input(peer, steal_tx, map[n], wscripts[n], &sig.sig);
steal_tx->input[map[n]].witness
= bitcoin_witness_secret(steal_tx,
ci->revocation_preimage,
sizeof(*ci->revocation_preimage),
&sig,
wscripts[n]);
}
broadcast_tx(peer, steal_tx);
}
static void our_htlc_spent(struct peer *peer,
const struct bitcoin_tx *tx,
size_t input_num,
ptrint_t *pi)
{
struct channel_htlc *h;
struct sha256 preimage, sha;
size_t i = ptr2int(pi);
/* It should be spending the HTLC we expect. */
assert(peer->closing_onchain.ci->map[i] == tx->input[input_num].index);
/* 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 %zu", i);
/* Our timeout tx has all-zeroes, so we can distinguish it. */
if (memeqzero(tx->input[input_num].witness[1], sizeof(preimage)))
return;
memcpy(&preimage, tx->input[input_num].witness[1], sizeof(preimage));
sha256(&sha, &preimage, sizeof(preimage));
h = htlc_by_index(peer->closing_onchain.ci, i);
/* 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 %zu on-chain using r value",
i);
/* 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[i] = irrevocably_resolved(peer);
}
static void our_htlc_depth(struct peer *peer,
unsigned int depth,
const struct sha256_double *txid,
bool our_commit,
size_t i)
{
u32 mediantime;
struct channel_htlc *h;
/* Must be in a block. */
if (depth == 0)
return;
mediantime = get_tip_mediantime(peer->dstate);
h = htlc_by_index(peer->closing_onchain.ci, i);
/* 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.
*/
/* FIXME: Handle expiry in blocks. */
if (mediantime < abs_locktime_to_seconds(&h->expiry))
return;
if (our_commit) {
u32 csv_timeout;
/* FIXME: Handle CSV in blocks. */
csv_timeout = get_tx_mediantime(peer->dstate, txid)
+ rel_locktime_to_seconds(&peer->remote.locktime);
if (mediantime <= csv_timeout)
return;
}
/* BOLT #onchain:
*
* If the output has *timed out* and not been *resolved*, the node
* MUST *resolve* the output by spending it.
*/
if (!peer->closing_onchain.resolved[i]) {
peer->closing_onchain.resolved[i]
= htlc_timeout_tx(peer, peer->closing_onchain.ci, i);
broadcast_tx(peer, peer->closing_onchain.resolved[i]);
}
}
static void our_htlc_depth_ourcommit(struct peer *peer,
unsigned int depth,
const struct sha256_double *txid,
ptrint_t *i)
{
our_htlc_depth(peer, depth, txid, true, ptr2int(i));
}
static void our_htlc_depth_theircommit(struct peer *peer,
unsigned int depth,
const struct sha256_double *txid,
ptrint_t *i)
{
our_htlc_depth(peer, depth, txid, false, ptr2int(i));
}
static void resolve_our_htlcs(struct peer *peer,
const struct commit_info *ci,
const struct bitcoin_tx *tx,
const struct bitcoin_tx **resolved,
bool from_ourcommit,
size_t start, size_t num)
{
size_t i;
struct sha256_double txid;
bitcoin_txid(tx, &txid);
for (i = start; i < start + num; i++) {
/* Doesn't exist? Resolved by tx itself. */
if (ci->map[i] == -1) {
resolved[i] = tx;
continue;
}
/* 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(tx, peer, &txid, ci->map[i], our_htlc_spent,
int2ptr(i));
watch_txid(tx, peer, &txid,
from_ourcommit
? our_htlc_depth_ourcommit
: our_htlc_depth_theircommit,
int2ptr(i));
}
}
/* BOLT #onchain:
*
* If the node receives a redemption preimage for a *commitment tx* output it
* was offered, it MUST *resolve* the output by spending it using the
* preimage. Otherwise, the other node could spend it once it as *timed out*
* as above.
*/
bool resolve_one_htlc(struct peer *peer, u64 id, const struct sha256 *preimage)
{
FIXME_STUB(peer);
}
static void their_htlc_depth(struct peer *peer,
unsigned int depth,
const struct sha256_double *txid,
ptrint_t *pi)
{
u32 mediantime;
struct channel_htlc *h;
size_t i = ptr2int(pi);
/* Must be in a block. */
if (depth == 0)
return;
mediantime = get_tip_mediantime(peer->dstate);
h = htlc_by_index(peer->closing_onchain.ci, i);
/* BOLT #onchain:
*
* Otherwise, if the output HTLC has expired, it is considered
* *irrevocably resolved*.
*/
/* FIXME: Handle expiry in blocks. */
if (mediantime < abs_locktime_to_seconds(&h->expiry))
return;
peer->closing_onchain.resolved[i] = irrevocably_resolved(peer);
}
static void resolve_their_htlcs(struct peer *peer,
const struct commit_info *ci,
const struct bitcoin_tx *tx,
const struct bitcoin_tx **resolved,
size_t start, size_t num)
{
size_t i;
for (i = start; i < start + num; i++) {
/* Doesn't exist? Resolved by tx itself. */
if (ci->map[i] == -1) {
resolved[i] = tx;
continue;
}
watch_tx(tx, peer, tx, their_htlc_depth, int2ptr(i));
}
}
static void our_main_output_depth(struct peer *peer,
unsigned int depth,
const struct sha256_double *txid,
void *unused)
{
u32 mediantime, csv_timeout;
/* Not in block any more? */
if (depth == 0)
return;
mediantime = get_tip_mediantime(peer->dstate);
/* FIXME: Handle CSV in blocks. */
csv_timeout = get_tx_mediantime(peer->dstate, txid)
+ rel_locktime_to_seconds(&peer->remote.locktime);
if (mediantime <= csv_timeout)
return;
/* Already done? (FIXME: Delete after first time) */
if (peer->closing_onchain.resolved[0])
return;
/* 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[0] = bitcoin_spend_ours(peer);
broadcast_tx(peer, peer->closing_onchain.resolved[0]);
}
/* BOLT #onchain:
*
* When node A sees its own *commitment tx*:
*/
static void resolve_our_unilateral(struct peer *peer)
{
const struct bitcoin_tx *tx = peer->closing_onchain.tx;
const struct commit_info *ci = peer->closing_onchain.ci;
size_t num_ours, num_theirs;
peer->closing_onchain.resolved
= tal_arrz(tx, const struct bitcoin_tx *, tal_count(ci->map));
/* 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.
*/
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*.
*/
peer->closing_onchain.resolved[1] = tx;
num_ours = tal_count(ci->cstate->side[OURS].htlcs);
num_theirs = tal_count(ci->cstate->side[THEIRS].htlcs);
/* BOLT #onchain:
*
* 3. _A's offered HTLCs_: See On-chain HTLC Handling: Our Offers below.
*/
resolve_our_htlcs(peer, ci, tx,
peer->closing_onchain.resolved,
true, 2, num_ours);
/* BOLT #onchain:
*
* 4. _B's offered HTLCs_: See On-chain HTLC Handling: Their
* Offers below.
*/
resolve_their_htlcs(peer, ci, tx,
peer->closing_onchain.resolved,
2 + num_ours, num_theirs);
}
/* BOLT #onchain:
*
* Similarly, when node A sees a *commitment tx* from B:
*/
static void resolve_their_unilateral(struct peer *peer)
{
const struct bitcoin_tx *tx = peer->closing_onchain.tx;
const struct commit_info *ci = peer->closing_onchain.ci;
size_t num_ours, num_theirs;
peer->closing_onchain.resolved
= tal_arrz(tx, const struct bitcoin_tx *, tal_count(ci->map));
/* 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*.
*/
peer->closing_onchain.resolved[1] = tx;
/* BOLT #onchain:
*
* 2. _B's main output_: No action required, this output is
* considered *resolved* by the *commitment tx*.
*/
peer->closing_onchain.resolved[0] = tx;
num_ours = tal_count(ci->cstate->side[OURS].htlcs);
num_theirs = tal_count(ci->cstate->side[THEIRS].htlcs);
/* BOLT #onchain:
*
* 3. _A's offered HTLCs_: See On-chain HTLC Handling: Our Offers below.
*/
resolve_our_htlcs(peer, ci, tx,
peer->closing_onchain.resolved,
false, 2 + num_theirs, num_ours);
/* BOLT #onchain:
*
* 4. _B's offered HTLCs_: See On-chain HTLC Handling: Their
* Offers below.
*/
resolve_their_htlcs(peer, ci, tx,
peer->closing_onchain.resolved,
2, num_theirs);
}
static void resolve_mutual_close(struct peer *peer)
{
const struct bitcoin_tx *tx = peer->closing_onchain.tx;
/* 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").
*/
peer->closing_onchain.resolved
= tal_arr(tx, const struct bitcoin_tx *, 0);
}
/* Called every time the tx spending the funding tx changes depth. */
static void 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;
/* 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;
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;
}
/* 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);
}
/* We assume the tx is valid! Don't do a blockchain.info and feed this
* invalid transactions! */
static void anchor_spent(struct peer *peer,
const struct bitcoin_tx *tx,
size_t input_num,
void *unused)
{
struct sha256_double txid;
Pkt *err;
enum state newstate;
assert(input_num < tx->input_count);
/* We only ever sign single-input txs. */
if (input_num != 0)
fatal("Anchor spend by non-single input tx");
/* 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, &txid);
peer->closing_onchain.ci = find_commit(peer->remote.commit, &txid);
if (peer->closing_onchain.ci) {
if (peer->closing_onchain.ci->revocation_preimage) {
newstate = STATE_CLOSE_ONCHAIN_CHEATED;
err = pkt_err(peer, "Revoked transaction seen");
resolve_cheating(peer);
} else {
newstate = STATE_CLOSE_ONCHAIN_THEIR_UNILATERAL;
err = pkt_err(peer, "Unilateral close tx seen");
resolve_their_unilateral(peer);
}
} else if (txidmatch(peer->local.commit->tx, &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");
peer->closing_onchain.ci = peer->local.commit;
resolve_our_unilateral(peer);
} else if (is_mutual_close(peer, tx)) {
newstate = STATE_CLOSE_ONCHAIN_MUTUAL;
err = NULL;
resolve_mutual_close(peer);
} else {
/* 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.
*/
/* FIXME: Log harder! */
log_broken(peer->log, "Unknown tx spend! Funds may be lost!");
set_peer_state(peer,
STATE_ERR_INFORMATION_LEAK,
"anchor_spent");
/* No longer call into the state machine. */
peer->anchor.watches->depthok = INPUT_NONE;
return;
}
/* 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);
/* No longer call into the state machine. */
peer->anchor.watches->depthok = INPUT_NONE;
}
static void anchor_timeout(struct anchor_watch *w)
{
assert(w == w->peer->anchor.watches);
state_event(w->peer, w->timeout, NULL);
/* Freeing this gets rid of the other watches, and timer, too. */
w->peer->anchor.watches = tal_free(w);
}
void peer_watch_anchor(struct peer *peer,
enum state_input depthok,
enum state_input timeout)
{
struct anchor_watch *w;
w = peer->anchor.watches = tal(peer, struct anchor_watch);
w->peer = peer;
w->depthok = depthok;
w->timeout = timeout;
watch_txid(w, peer, &peer->anchor.txid, anchor_depthchange, NULL);
watch_txo(w, 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 (w->timeout != INPUT_NONE) {
w->timer = new_reltimer(peer->dstate, w,
time_from_sec(7200
+ 20*peer->local.mindepth),
anchor_timeout, w);
} else
w->timer = NULL;
}
void peer_unwatch_anchor_depth(struct peer *peer,
enum state_input depthok,
enum state_input timeout)
{
assert(peer->anchor.watches);
assert(peer->anchor.watches->depthok == depthok);
peer->anchor.watches->depthok = INPUT_NONE;
}
uint64_t commit_tx_fee(const struct bitcoin_tx *commit, uint64_t 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 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": to %02x%02x%02x%02x/%02x%02x%02x%02x, amounts %u/%u",
fee,
peer->local.finalkey.der[0], peer->local.finalkey.der[1],
peer->local.finalkey.der[2], peer->local.finalkey.der[3],
peer->remote.finalkey.der[0], peer->remote.finalkey.der[1],
peer->remote.finalkey.der[2], peer->remote.finalkey.der[3],
cstate.side[OURS].pay_msat / 1000,
cstate.side[THEIRS].pay_msat / 1000);
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);
}
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));
}
void peer_unexpected_pkt(struct peer *peer, const Pkt *pkt)
{
const char *p;
/* 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);
}
/* Create a bitcoin close tx, using last signature they sent. */
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->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) */
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->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);
bitcoin_txid(commit, &tx->input[0].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->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, NULL, 0, &sig,
witnessscript);
return tx;
}
/* Sign and return our commit tx */
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->local.commit->sig,
&sig,
&peer->remote.commitkey,
&peer->local.commitkey);
return peer->local.commit->tx;
}
/* 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: release the utxos.
* If done != INPUT_NONE, remove existing create_anchor too. */
void bitcoin_release_anchor(struct peer *peer, enum state_input done)
{
/* FIXME: stop bitcoind command */
log_unusual(peer->log, "Anchor not spent, please -zapwallettxs");
}
/* Get the bitcoin anchor tx. */
const struct bitcoin_tx *bitcoin_anchor(struct peer *peer)
{
return peer->anchor.tx;
}
void add_unacked(struct peer_visible_state *which,
const union htlc_staging *stage)
{
size_t n = tal_count(which->commit->unacked_changes);
tal_resize(&which->commit->unacked_changes, n+1);
which->commit->unacked_changes[n] = *stage;
}
/* 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_funding(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 = copy_funding(peer,
peer->local.commit->cstate);
peer->local.commit->tx = create_commit_tx(peer->local.commit,
&peer->local.finalkey,
&peer->remote.finalkey,
&peer->local.locktime,
&peer->remote.locktime,
&peer->anchor.txid,
peer->anchor.index,
peer->anchor.satoshis,
&peer->local.commit->revocation_hash,
peer->local.commit->cstate,
OURS,
&peer->local.commit->map);
peer->remote.commit->tx = create_commit_tx(peer->remote.commit,
&peer->local.finalkey,
&peer->remote.finalkey,
&peer->local.locktime,
&peer->remote.locktime,
&peer->anchor.txid,
peer->anchor.index,
peer->anchor.satoshis,
&peer->remote.commit->revocation_hash,
peer->remote.commit->cstate,
THEIRS,
&peer->remote.commit->map);
peer->local.staging_cstate = copy_funding(peer, peer->local.commit->cstate);
peer->remote.staging_cstate = copy_funding(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_htlcs(struct json_result *response,
const char *id,
const struct channel_oneside *side)
{
size_t i;
json_array_start(response, id);
for (i = 0; i < tal_count(side->htlcs); i++) {
json_object_start(response, NULL);
json_add_u64(response, "msatoshis", side->htlcs[i].msatoshis);
json_add_abstime(response, "expiry", &side->htlcs[i].expiry);
json_add_hex(response, "rhash",
&side->htlcs[i].rhash,
sizeof(side->htlcs[i].rhash));
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));
/* This is only valid after crypto setup. */
if (p->state != STATE_INIT)
json_add_hex(response, "peerid",
p->id.der, sizeof(p->id.der));
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", &last->side[OURS]);
json_add_htlcs(response, "their_htlcs", &last->side[THEIRS]);
/* Any changes since then? */
if (p->local.staging_cstate->changes != last->changes)
json_add_num(response, "local_staged_changes",
p->local.staging_cstate->changes
- last->changes);
if (p->remote.staging_cstate->changes
!= p->remote.commit->cstate->changes)
json_add_num(response, "remote_staged_changes",
p->remote.staging_cstate->changes
- p->remote.commit->cstate->changes);
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"
};
/* FIXME: Keep a timeout for each peer, in case they're unresponsive. */
/* FIXME: Make sure no HTLCs in any unrevoked commit tx are live. */
static void check_htlc_expiry(struct peer *peer)
{
size_t i;
log_debug(peer->log, "Expiry timedout!");
/* 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 channel_htlc *htlc = &peer->remote.staging_cstate->side[THEIRS].htlcs[i];
/* Not a seconds-based expiry? */
if (!abs_locktime_is_seconds(&htlc->expiry))
continue;
/* Not well-expired? */
if (controlled_time().ts.tv_sec - 30
< abs_locktime_to_seconds(&htlc->expiry))
continue;
/* This can fail only if we're in an error state. */
command_htlc_fail(peer, htlc->id, NULL);
return;
}
}
void peer_add_htlc_expiry(struct peer *peer,
const struct abs_locktime *expiry)
{
struct timeabs absexpiry;
/* Add 30 seconds to be sure peers agree on timeout. */
absexpiry.ts.tv_sec = abs_locktime_to_seconds(expiry) + 30;
absexpiry.ts.tv_nsec = 0;
new_abstimer(peer->dstate, peer, absexpiry, check_htlc_expiry, peer);
}
/* We do final checks just before we start command, as things may have
* changed. */
static void do_newhtlc(struct peer *peer,
const struct channel_htlc *htlc,
struct command *jsoncmd)
{
struct channel_state *cstate;
union input idata;
struct htlc_progress prog;
/* Now we can assign counter and guarantee uniqueness. */
prog.stage.add.add = HTLC_ADD;
prog.stage.add.htlc = *htlc;
prog.stage.add.htlc.id = peer->htlc_id_counter;
/* BOLT #2:
*
* A node MUST NOT add a HTLC if it would result in it
* offering more than 300 HTLCs in either commitment transaction.
*/
if (tal_count(peer->local.staging_cstate->side[OURS].htlcs) == 300
|| tal_count(peer->remote.staging_cstate->side[OURS].htlcs) == 300) {
command_fail(jsoncmd, "Too many HTLCs");
return;
}
if (!state_can_add_htlc(peer->state)) {
command_fail(jsoncmd, "Channel closing, state %s",
state_name(peer->state));
return;
}
/* BOLT #2:
*
* A node MUST NOT offer `amount_msat` it cannot pay for in
* both commitment transactions at the current `fee_rate`
*/
cstate = copy_funding(jsoncmd, peer->remote.staging_cstate);
if (!funding_add_htlc(cstate, htlc->msatoshis,
&htlc->expiry, &htlc->rhash,
htlc->id, OURS)) {
command_fail(jsoncmd,
"Cannot afford %"PRIu64
" milli-satoshis in their commit tx",
htlc->msatoshis);
return;
}
cstate = copy_funding(jsoncmd, peer->local.staging_cstate);
if (!funding_add_htlc(cstate, htlc->msatoshis,
&htlc->expiry, &htlc->rhash,
htlc->id, OURS)) {
command_fail(jsoncmd,
"Cannot afford %"PRIu64
" milli-satoshis in our commit tx",
htlc->msatoshis);
return;
}
/* Make sure we never offer the same one twice. */
peer->htlc_id_counter++;
/* FIXME: Never propose duplicate rvalues? */
idata.htlc_prog = &prog;
state_event(peer, CMD_SEND_HTLC_ADD, &idata);
command_success(jsoncmd, null_response(jsoncmd));
}
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;
struct channel_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(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, &htlc.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 (!seconds_to_abs_locktime(expiry, &htlc.expiry)) {
command_fail(cmd, "'%.*s' is not a valid number",
(int)(expirytok->end - expirytok->start),
buffer + expirytok->start);
return;
}
if (abs_locktime_to_seconds(&htlc.expiry) <
controlled_time().ts.tv_sec + peer->dstate->config.min_expiry) {
command_fail(cmd, "HTLC expiry too soon!");
return;
}
if (abs_locktime_to_seconds(&htlc.expiry) >
controlled_time().ts.tv_sec + peer->dstate->config.max_expiry) {
command_fail(cmd, "HTLC expiry too far!");
return;
}
if (!hex_decode(buffer + rhashtok->start,
rhashtok->end - rhashtok->start,
&htlc.rhash,
sizeof(htlc.rhash))) {
command_fail(cmd, "'%.*s' is not a valid sha256 hash",
(int)(rhashtok->end - rhashtok->start),
buffer + rhashtok->start);
return;
}
do_newhtlc(peer, &htlc, cmd);
}
/* FIXME: Use HTLC ids, not r values! */
const struct json_command newhtlc_command = {
"newhtlc",
json_newhtlc,
"Offer {peerid} an HTLC worth {msatoshis} in {expiry} (in seconds since Jan 1 1970) with {rhash}",
"Returns an empty result on success"
};
/* Looks for their HTLC, but must be committed. */
static size_t find_their_committed_htlc(struct peer *peer,
const struct sha256 *rhash)
{
/* Must be in last committed cstate. */
if (funding_find_htlc(peer->remote.commit->cstate, rhash, THEIRS) == -1)
return -1;
return funding_find_htlc(peer->remote.staging_cstate, rhash, THEIRS);
}
static void do_fullfill(struct peer *peer,
const struct sha256 *r,
struct command *jsoncmd)
{
struct sha256 rhash;
size_t i;
u64 id;
sha256(&rhash, r, sizeof(*r));
i = find_their_committed_htlc(peer, &rhash);
if (i == -1) {
command_fail(jsoncmd, "preimage htlc not found");
return;
}
id = peer->remote.staging_cstate->side[THEIRS].htlcs[i].id;
command_htlc_fulfill(peer, id, r, jsoncmd);
}
static void json_fulfillhtlc(struct command *cmd,
const char *buffer, const jsmntok_t *params)
{
struct peer *peer;
jsmntok_t *peeridtok, *rtok;
struct sha256 r;
if (!json_get_params(buffer, params,
"peerid", &peeridtok,
"r", &rtok,
NULL)) {
command_fail(cmd, "Need peerid and r");
return;
}
peer = find_peer(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 (!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;
}
do_fullfill(peer, &r, cmd);
}
const struct json_command fulfillhtlc_command = {
"fulfillhtlc",
json_fulfillhtlc,
"Redeem htlc proposed by {peerid} using {r}",
"Returns an empty result on success"
};
/* FIXME: Flatten into json_failhtlc. */
static void do_failhtlc(struct peer *peer,
const struct sha256 *rhash,
struct command *jsoncmd)
{
size_t i;
u64 id;
/* Look in peer->remote.staging_cstate->a, as that's where we'll
* immediately remove it from: avoids double-handling. */
i = find_their_committed_htlc(peer, rhash);
if (i == -1) {
command_fail(jsoncmd, "htlc not found");
return;
}
id = peer->remote.staging_cstate->side[THEIRS].htlcs[i].id;
command_htlc_fail(peer, id, jsoncmd);
}
static void json_failhtlc(struct command *cmd,
const char *buffer, const jsmntok_t *params)
{
struct peer *peer;
jsmntok_t *peeridtok, *rhashtok;
struct sha256 rhash;
if (!json_get_params(buffer, params,
"peerid", &peeridtok,
"rhash", &rhashtok,
NULL)) {
command_fail(cmd, "Need peerid and rhash");
return;
}
peer = find_peer(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 (!hex_decode(buffer + rhashtok->start,
rhashtok->end - rhashtok->start,
&rhash, sizeof(rhash))) {
command_fail(cmd, "'%.*s' is not a valid sha256 preimage",
(int)(rhashtok->end - rhashtok->start),
buffer + rhashtok->start);
return;
}
do_failhtlc(peer, &rhash, cmd);
}
const struct json_command failhtlc_command = {
"failhtlc",
json_failhtlc,
"Fail htlc proposed by {peerid} which has redeem hash {rhash}",
"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(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(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(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(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(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"
};