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lightning/lightningd/channel/channel.c

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#include <bitcoin/privkey.h>
#include <bitcoin/script.h>
#include <ccan/container_of/container_of.h>
#include <ccan/crypto/hkdf_sha256/hkdf_sha256.h>
#include <ccan/crypto/shachain/shachain.h>
#include <ccan/fdpass/fdpass.h>
#include <ccan/io/io.h>
#include <ccan/structeq/structeq.h>
#include <ccan/take/take.h>
#include <ccan/tal/str/str.h>
#include <ccan/time/time.h>
#include <daemon/routing.h>
#include <daemon/timeout.h>
#include <errno.h>
#include <inttypes.h>
#include <lightningd/channel.h>
#include <lightningd/channel/gen_channel_wire.h>
#include <lightningd/commit_tx.h>
#include <lightningd/crypto_sync.h>
#include <lightningd/cryptomsg.h>
#include <lightningd/daemon_conn.h>
#include <lightningd/debug.h>
#include <lightningd/derive_basepoints.h>
#include <lightningd/htlc_tx.h>
#include <lightningd/key_derive.h>
#include <lightningd/msg_queue.h>
#include <lightningd/peer_failed.h>
#include <lightningd/status.h>
#include <secp256k1.h>
#include <signal.h>
#include <stdio.h>
#include <type_to_string.h>
#include <version.h>
#include <wire/gen_onion_wire.h>
#include <wire/gen_peer_wire.h>
#include <wire/wire.h>
#include <wire/wire_io.h>
#include <wire/wire_sync.h>
/* stdin == requests, 3 == peer, 4 = gossip */
#define REQ_FD STDIN_FILENO
#define PEER_FD 3
#define GOSSIP_FD 4
struct peer {
struct peer_crypto_state pcs;
struct channel_config conf[NUM_SIDES];
struct pubkey old_per_commit[NUM_SIDES];
struct pubkey current_per_commit[NUM_SIDES];
bool funding_locked[NUM_SIDES];
u64 commit_index[NUM_SIDES];
/* Their sig for current commit. */
secp256k1_ecdsa_signature their_commit_sig;
/* Secret keys and basepoint secrets. */
struct secrets our_secrets;
/* Our shaseed for generating per-commitment-secrets. */
struct sha256 shaseed;
/* Their shachain. */
struct shachain their_shachain;
/* BOLT #2:
*
* A sending node MUST set `id` to 0 for the first HTLC it offers, and
* increase the value by 1 for each successive offer.
*/
u64 htlc_id;
struct channel_id channel_id;
struct channel *channel;
struct msg_queue peer_out;
struct io_conn *peer_conn;
struct daemon_conn gossip_client;
struct daemon_conn master;
struct timers timers;
struct oneshot *commit_timer;
u32 commit_msec;
/* Announcement related information */
struct pubkey node_ids[NUM_SIDES];
struct short_channel_id short_channel_ids[NUM_SIDES];
secp256k1_ecdsa_signature announcement_node_sigs[NUM_SIDES];
secp256k1_ecdsa_signature announcement_bitcoin_sigs[NUM_SIDES];
/* Which direction of the channel do we control? */
u16 channel_direction;
};
static struct io_plan *gossip_client_recv(struct io_conn *conn,
struct daemon_conn *dc)
{
u8 *msg = dc->msg_in;
struct peer *peer = container_of(dc, struct peer, gossip_client);
u16 type = fromwire_peektype(msg);
if (type == WIRE_CHANNEL_ANNOUNCEMENT || type == WIRE_CHANNEL_UPDATE ||
type == WIRE_NODE_ANNOUNCEMENT)
msg_enqueue(&peer->peer_out, msg);
return daemon_conn_read_next(conn, dc);
}
static void send_announcement_signatures(struct peer *peer)
{
tal_t *tmpctx = tal_tmpctx(peer);
u8 *msg;
// TODO(cdecker) Use the HSM to generate this signature
secp256k1_ecdsa_signature *sig =
talz(tmpctx, secp256k1_ecdsa_signature);
msg = towire_announcement_signatures(tmpctx, &peer->channel_id,
&peer->short_channel_ids[LOCAL],
sig, sig);
msg_enqueue(&peer->peer_out, take(msg));
tal_free(tmpctx);
}
static void send_channel_update(struct peer *peer, bool disabled)
{
tal_t *tmpctx = tal_tmpctx(peer);
u32 timestamp = time_now().ts.tv_sec;
u16 flags;
u8 *cupdate;
// TODO(cdecker) Create a real signature for this update
secp256k1_ecdsa_signature *sig =
talz(tmpctx, secp256k1_ecdsa_signature);
flags = peer->channel_direction | (disabled << 1);
cupdate = towire_channel_update(
tmpctx, sig, &peer->short_channel_ids[LOCAL], timestamp, flags, 36,
1, 10, peer->channel->view[LOCAL].feerate_per_kw);
daemon_conn_send(&peer->gossip_client, take(cupdate));
msg_enqueue(&peer->peer_out, cupdate);
tal_free(tmpctx);
}
/* Now that we have a working channel, tell the world. */
static void send_channel_announcement(struct peer *peer)
{
tal_t *tmpctx = tal_tmpctx(peer);
int first, second;
u8 *cannounce, *features = tal_arr(peer, u8, 0);
if (peer->channel_direction == 0) {
first = LOCAL;
second = REMOTE;
} else {
first = REMOTE;
second = LOCAL;
}
cannounce = towire_channel_announcement(
tmpctx, &peer->announcement_node_sigs[first],
&peer->announcement_node_sigs[second],
&peer->announcement_bitcoin_sigs[first],
&peer->announcement_bitcoin_sigs[second],
&peer->short_channel_ids[LOCAL], &peer->node_ids[first],
&peer->node_ids[second], &peer->channel->funding_pubkey[first],
&peer->channel->funding_pubkey[second], features);
msg_enqueue(&peer->peer_out, cannounce);
daemon_conn_send(&peer->gossip_client, take(cannounce));
tal_free(tmpctx);
}
static struct io_plan *peer_out(struct io_conn *conn, struct peer *peer)
{
const u8 *out = msg_dequeue(&peer->peer_out);
if (!out)
return msg_queue_wait(conn, &peer->peer_out, peer_out, peer);
return peer_write_message(conn, &peer->pcs, out, peer_out);
}
static void handle_peer_funding_locked(struct peer *peer, const u8 *msg)
{
struct channel_id chanid;
if (!fromwire_funding_locked(msg, NULL, &chanid,
&peer->current_per_commit[REMOTE]))
status_failed(WIRE_CHANNEL_PEER_BAD_MESSAGE,
"Bad funding_locked %s", tal_hex(msg, msg));
if (!structeq(&chanid, &peer->channel_id))
status_failed(WIRE_CHANNEL_PEER_BAD_MESSAGE,
"Wrong channel id in %s", tal_hex(trc, msg));
if (peer->funding_locked[REMOTE])
status_failed(WIRE_CHANNEL_PEER_BAD_MESSAGE,
"Funding locked twice");
peer->funding_locked[REMOTE] = true;
daemon_conn_send(&peer->master,
take(towire_channel_received_funding_locked(peer)));
if (peer->funding_locked[LOCAL]) {
daemon_conn_send(&peer->master,
take(towire_channel_normal_operation(peer)));
}
}
static void handle_peer_announcement_signatures(struct peer *peer, const u8 *msg)
{
struct channel_id chanid;
if (!fromwire_announcement_signatures(msg, NULL,
&chanid,
&peer->short_channel_ids[REMOTE],
&peer->announcement_node_sigs[REMOTE],
&peer->announcement_bitcoin_sigs[REMOTE]))
status_failed(WIRE_CHANNEL_PEER_BAD_MESSAGE,
"Bad announcement_signatures %s",
tal_hex(msg, msg));
/* Make sure we agree on the channel ids */
/* FIXME: Check short_channel_id */
if (!structeq(&chanid, &peer->channel_id)) {
status_failed(WIRE_CHANNEL_PEER_BAD_MESSAGE,
"Wrong channel_id or short_channel_id in %s or %s",
tal_hexstr(trc, &chanid, sizeof(struct channel_id)),
tal_hexstr(trc, &peer->short_channel_ids[REMOTE],
sizeof(struct short_channel_id)));
}
if (peer->funding_locked[LOCAL]) {
send_channel_announcement(peer);
send_channel_update(peer, false);
}
}
static void handle_peer_add_htlc(struct peer *peer, const u8 *msg)
{
struct channel_id channel_id;
u64 id;
u32 amount_msat;
u32 cltv_expiry;
struct sha256 payment_hash;
u8 onion_routing_packet[1254];
enum channel_add_err add_err;
if (!fromwire_update_add_htlc(msg, NULL, &channel_id, &id, &amount_msat,
&cltv_expiry, &payment_hash,
onion_routing_packet))
peer_failed(io_conn_fd(peer->peer_conn),
&peer->pcs.cs,
&peer->channel_id,
WIRE_CHANNEL_PEER_BAD_MESSAGE,
"Bad peer_add_htlc %s", tal_hex(msg, msg));
add_err = channel_add_htlc(peer->channel, REMOTE, id, amount_msat,
cltv_expiry, &payment_hash,
onion_routing_packet);
if (add_err != CHANNEL_ERR_ADD_OK)
peer_failed(io_conn_fd(peer->peer_conn),
&peer->pcs.cs,
&peer->channel_id,
WIRE_CHANNEL_PEER_BAD_MESSAGE,
"Bad peer_add_htlc: %u", add_err);
}
static void send_commit(struct peer *peer)
{
tal_t *tmpctx = tal_tmpctx(peer);
u8 *msg;
secp256k1_ecdsa_signature commit_sig, *htlc_sigs;
size_t i;
struct bitcoin_tx **txs;
const u8 **wscripts;
const struct htlc **htlc_map;
struct pubkey localkey;
struct privkey local_secretkey;
/* Timer has expired. */
peer->commit_timer = NULL;
/* FIXME: Document this requirement in BOLT 2! */
/* We can't send two commits in a row. */
if (channel_awaiting_revoke_and_ack(peer->channel)) {
status_trace("Can't send commit: waiting for revoke_and_ack");
tal_free(tmpctx);
return;
}
/* BOLT #2:
*
* A node MUST NOT send a `commitment_signed` message which does not
* include any updates.
*/
if (!channel_sending_commit(peer->channel)) {
status_trace("Can't send commit: nothing to send");
tal_free(tmpctx);
return;
}
if (!derive_simple_privkey(&peer->our_secrets.payment_basepoint_secret,
&peer->channel->basepoints[LOCAL].payment,
&peer->current_per_commit[REMOTE],
&local_secretkey))
status_failed(WIRE_CHANNEL_CRYPTO_FAILED,
"Deriving local_secretkey");
if (!derive_simple_key(&peer->channel->basepoints[LOCAL].payment,
&peer->current_per_commit[REMOTE],
&localkey))
status_failed(WIRE_CHANNEL_CRYPTO_FAILED,
"Deriving localkey");
txs = channel_txs(tmpctx, &htlc_map, &wscripts, peer->channel,
&peer->current_per_commit[REMOTE], REMOTE);
sign_tx_input(txs[0], 0, NULL,
wscripts[0],
&peer->our_secrets.funding_privkey,
&peer->channel->funding_pubkey[LOCAL],
&commit_sig);
status_trace("Creating commit_sig signature %s for tx %s wscript %s key %s",
type_to_string(trc, secp256k1_ecdsa_signature,
&commit_sig),
type_to_string(trc, struct bitcoin_tx, txs[0]),
tal_hex(trc, wscripts[0]),
type_to_string(trc, struct pubkey,
&peer->channel->funding_pubkey[LOCAL]));
/* BOLT #2:
*
* A node MUST include one `htlc-signature` for every HTLC transaction
* corresponding to BIP69 lexicographic ordering of the commitment
* transaction.
*/
htlc_sigs = tal_arr(tmpctx, secp256k1_ecdsa_signature,
tal_count(txs) - 1);
for (i = 0; i < tal_count(htlc_sigs); i++) {
sign_tx_input(txs[1 + i], 0,
NULL,
wscripts[1 + i],
&local_secretkey, &localkey,
&htlc_sigs[i]);
status_trace("Creating HTLC signature %s for tx %s wscript %s key %s",
type_to_string(trc, secp256k1_ecdsa_signature,
&htlc_sigs[i]),
type_to_string(trc, struct bitcoin_tx, txs[1+i]),
tal_hex(trc, wscripts[1+i]),
type_to_string(trc, struct pubkey, &localkey));
assert(check_tx_sig(txs[1+i], 0, NULL, wscripts[1+i],
&localkey, &htlc_sigs[i]));
}
status_trace("Sending commit_sig with %zu htlc sigs",
tal_count(htlc_sigs));
msg = towire_commitment_signed(tmpctx, &peer->channel_id,
&commit_sig, htlc_sigs);
msg_enqueue(&peer->peer_out, take(msg));
tal_free(tmpctx);
}
static void start_commit_timer(struct peer *peer)
{
/* Already armed? */
if (peer->commit_timer)
return;
peer->commit_timer = new_reltimer(&peer->timers, peer,
time_from_msec(peer->commit_msec),
send_commit, peer);
}
static void handle_peer_commit_sig(struct peer *peer, const u8 *msg)
{
tal_t *tmpctx = tal_tmpctx(peer);
struct sha256 old_commit_secret;
struct channel_id channel_id;
secp256k1_ecdsa_signature commit_sig, *htlc_sigs;
struct pubkey remotekey;
struct bitcoin_tx **txs;
const struct htlc **htlc_map;
const u8 **wscripts;
size_t i;
/* FIXME: Handle theirsfulfilled! */
if (!channel_rcvd_commit(peer->channel, NULL, peer)) {
/* BOLT #2:
*
* A node MUST NOT send a `commitment_signed` message which
* does not include any updates.
*/
peer_failed(io_conn_fd(peer->peer_conn),
&peer->pcs.cs,
&peer->channel_id,
WIRE_CHANNEL_PEER_BAD_MESSAGE,
"commit_sig with no changes");
}
if (!fromwire_commitment_signed(tmpctx, msg, NULL,
&channel_id, &commit_sig, &htlc_sigs))
peer_failed(io_conn_fd(peer->peer_conn),
&peer->pcs.cs,
&peer->channel_id,
WIRE_CHANNEL_PEER_BAD_MESSAGE,
"Bad commit_sig %s", tal_hex(msg, msg));
txs = channel_txs(tmpctx, &htlc_map, &wscripts, peer->channel,
&peer->current_per_commit[LOCAL], LOCAL);
if (!derive_simple_key(&peer->channel->basepoints[REMOTE].payment,
&peer->current_per_commit[LOCAL],
&remotekey))
status_failed(WIRE_CHANNEL_CRYPTO_FAILED,
"Deriving remotekey");
/* BOLT #2:
*
* A receiving node MUST fail the channel if `signature` is not valid
* for its local commitment transaction once all pending updates are
* applied.
*/
if (!check_tx_sig(txs[0], 0, NULL, wscripts[0],
&peer->channel->funding_pubkey[REMOTE], &commit_sig))
peer_failed(io_conn_fd(peer->peer_conn),
&peer->pcs.cs,
&peer->channel_id,
WIRE_CHANNEL_PEER_BAD_MESSAGE,
"Bad commit_sig signature %s for tx %s wscript %s key %s",
type_to_string(msg, secp256k1_ecdsa_signature,
&commit_sig),
type_to_string(msg, struct bitcoin_tx, txs[0]),
tal_hex(msg, wscripts[0]),
type_to_string(msg, struct pubkey,
&peer->channel->funding_pubkey
[REMOTE]));
/* BOLT #2:
*
* A receiving node MUST fail the channel if `num-htlcs` is not equal
* to the number of HTLC outputs in the local commitment transaction
* once all pending updates are applied.
*/
if (tal_count(htlc_sigs) != tal_count(txs) - 1)
peer_failed(io_conn_fd(peer->peer_conn),
&peer->pcs.cs,
&peer->channel_id,
WIRE_CHANNEL_PEER_BAD_MESSAGE,
"Expected %zu htlc sigs, not %zu",
tal_count(txs) - 1, tal_count(htlc_sigs));
/* BOLT #2:
*
* A receiving node MUST fail
* the channel if any `htlc-signature` is not valid for the
* corresponding HTLC transaction.
*/
for (i = 0; i < tal_count(htlc_sigs); i++) {
if (!check_tx_sig(txs[1+i], 0, NULL, wscripts[1+i],
&remotekey, &htlc_sigs[i]))
peer_failed(io_conn_fd(peer->peer_conn),
&peer->pcs.cs,
&peer->channel_id,
WIRE_CHANNEL_PEER_BAD_MESSAGE,
"Bad commit_sig signature %s for htlc %s wscript %s key %s",
type_to_string(msg, secp256k1_ecdsa_signature, &htlc_sigs[i]),
type_to_string(msg, struct bitcoin_tx, txs[1+i]),
tal_hex(msg, wscripts[1+i]),
type_to_string(msg, struct pubkey, &remotekey));
}
status_trace("Received commit_sig with %zu htlc sigs",
tal_count(htlc_sigs));
struct pubkey oldpoint = peer->old_per_commit[LOCAL], test;
status_trace("Sending secret for point %"PRIu64" %s",
peer->commit_index[LOCAL]-1,
type_to_string(trc, struct pubkey,
&peer->old_per_commit[LOCAL]));
peer->old_per_commit[LOCAL] = peer->current_per_commit[LOCAL];
if (!next_per_commit_point(&peer->shaseed, &old_commit_secret,
&peer->current_per_commit[LOCAL],
peer->commit_index[LOCAL]))
status_failed(WIRE_CHANNEL_CRYPTO_FAILED,
"Deriving next commit_point");
pubkey_from_privkey((struct privkey *)&old_commit_secret, &test);
if (!pubkey_eq(&test, &oldpoint))
status_failed(WIRE_CHANNEL_CRYPTO_FAILED,
"Invalid secret %s for commit_point",
tal_hexstr(msg, &old_commit_secret,
sizeof(old_commit_secret)));
peer->commit_index[LOCAL]++;
/* If this queues more changes on the other end, send commit. */
if (channel_sending_revoke_and_ack(peer->channel)) {
status_trace("revoke_and_ack made pending: commit timer");
start_commit_timer(peer);
}
msg = towire_revoke_and_ack(msg, &channel_id, &old_commit_secret,
&peer->current_per_commit[LOCAL]);
msg_enqueue(&peer->peer_out, take(msg));
tal_free(tmpctx);
}
static void our_htlc_failed(const struct htlc *htlc, struct peer *peer)
{
status_trace("FIXME: our htlc %"PRIu64" failed", htlc->id);
}
static void their_htlc_locked(const struct htlc *htlc, struct peer *peer)
{
status_trace("FIXME: their htlc %"PRIu64" locked", htlc->id);
}
static void handle_peer_revoke_and_ack(struct peer *peer, const u8 *msg)
{
struct sha256 old_commit_secret;
struct privkey privkey;
struct channel_id channel_id;
struct pubkey per_commit_point, next_per_commit;
if (!fromwire_revoke_and_ack(msg, NULL, &channel_id, &old_commit_secret,
&next_per_commit)) {
peer_failed(io_conn_fd(peer->peer_conn),
&peer->pcs.cs,
&peer->channel_id,
WIRE_CHANNEL_PEER_BAD_MESSAGE,
"Bad revoke_and_ack %s", tal_hex(msg, msg));
}
/* BOLT #2:
*
* A receiving node MUST check that `per-commitment-secret` generates
* the previous `per-commitment-point`, and MUST fail if it does
* not.
*/
memcpy(&privkey, &old_commit_secret, sizeof(privkey));
if (!pubkey_from_privkey(&privkey, &per_commit_point)) {
peer_failed(io_conn_fd(peer->peer_conn),
&peer->pcs.cs,
&peer->channel_id,
WIRE_CHANNEL_PEER_BAD_MESSAGE,
"Bad privkey %s",
type_to_string(msg, struct privkey, &privkey));
}
if (!pubkey_eq(&per_commit_point, &peer->old_per_commit[REMOTE])) {
peer_failed(io_conn_fd(peer->peer_conn),
&peer->pcs.cs,
&peer->channel_id,
WIRE_CHANNEL_PEER_BAD_MESSAGE,
"Wrong privkey %s for %s",
type_to_string(msg, struct privkey, &privkey),
type_to_string(msg, struct pubkey,
&peer->old_per_commit[REMOTE]));
}
/* BOLT #2:
*
* A receiving node MAY fail if the `per-commitment-secret` was not
* generated by the protocol in [BOLT #3]
*/
if (!shachain_add_hash(&peer->their_shachain,
281474976710655ULL - peer->commit_index[REMOTE],
&old_commit_secret)) {
peer_failed(io_conn_fd(peer->peer_conn),
&peer->pcs.cs,
&peer->channel_id,
WIRE_CHANNEL_PEER_BAD_MESSAGE,
"Bad shachain for privkey %"PRIu64" %s ",
peer->commit_index[REMOTE],
type_to_string(msg, struct privkey, &privkey));
}
peer->commit_index[REMOTE]++;
peer->old_per_commit[REMOTE] = peer->current_per_commit[REMOTE];
peer->current_per_commit[REMOTE] = next_per_commit;
/* We start timer even if this returns false: we might have delayed
* commit because we were waiting for this! */
if (channel_rcvd_revoke_and_ack(peer->channel,
our_htlc_failed, their_htlc_locked,
peer))
status_trace("Commits outstanding after recv revoke_and_ack");
else
status_trace("No commits outstanding after recv revoke_and_ack");
start_commit_timer(peer);
}
static struct io_plan *peer_in(struct io_conn *conn, struct peer *peer, u8 *msg)
{
enum wire_type type = fromwire_peektype(msg);
/* Must get funding_locked before almost anything. */
if (!peer->funding_locked[REMOTE]) {
/* We can get gossup before funging, too */
if (type != WIRE_FUNDING_LOCKED
&& type != WIRE_CHANNEL_ANNOUNCEMENT
&& type != WIRE_CHANNEL_UPDATE
&& type != WIRE_NODE_ANNOUNCEMENT) {
peer_failed(io_conn_fd(peer->peer_conn),
&peer->pcs.cs,
&peer->channel_id,
WIRE_CHANNEL_PEER_BAD_MESSAGE,
"%s (%u) before funding locked",
wire_type_name(type), type);
}
}
switch (type) {
case WIRE_FUNDING_LOCKED:
handle_peer_funding_locked(peer, msg);
goto done;
case WIRE_ANNOUNCEMENT_SIGNATURES:
handle_peer_announcement_signatures(peer, msg);
goto done;
case WIRE_CHANNEL_ANNOUNCEMENT:
case WIRE_CHANNEL_UPDATE:
case WIRE_NODE_ANNOUNCEMENT:
/* Forward to gossip daemon */
daemon_conn_send(&peer->gossip_client, msg);
goto done;
case WIRE_UPDATE_ADD_HTLC:
handle_peer_add_htlc(peer, msg);
goto done;
case WIRE_COMMITMENT_SIGNED:
handle_peer_commit_sig(peer, msg);
goto done;
case WIRE_REVOKE_AND_ACK:
handle_peer_revoke_and_ack(peer, msg);
goto done;
case WIRE_INIT:
case WIRE_ERROR:
case WIRE_OPEN_CHANNEL:
case WIRE_ACCEPT_CHANNEL:
case WIRE_FUNDING_CREATED:
case WIRE_FUNDING_SIGNED:
goto badmessage;
case WIRE_SHUTDOWN:
case WIRE_CLOSING_SIGNED:
case WIRE_UPDATE_FULFILL_HTLC:
case WIRE_UPDATE_FAIL_HTLC:
case WIRE_UPDATE_FAIL_MALFORMED_HTLC:
case WIRE_UPDATE_FEE:
peer_failed(io_conn_fd(peer->peer_conn),
&peer->pcs.cs,
&peer->channel_id,
WIRE_CHANNEL_PEER_BAD_MESSAGE,
"Unimplemented message %u (%s)",
type, wire_type_name(type));
}
badmessage:
peer_failed(io_conn_fd(peer->peer_conn),
&peer->pcs.cs,
&peer->channel_id,
WIRE_CHANNEL_PEER_BAD_MESSAGE,
"Peer sent unknown message %u (%s)",
type, wire_type_name(type));
done:
return peer_read_message(conn, &peer->pcs, peer_in);
}
static struct io_plan *setup_peer_conn(struct io_conn *conn, struct peer *peer)
{
return io_duplex(conn, peer_read_message(conn, &peer->pcs, peer_in),
peer_out(conn, peer));
}
static void peer_conn_broken(struct io_conn *conn, struct peer *peer)
{
send_channel_update(peer, true);
/* Make sure gossipd actually gets this message before dying */
daemon_conn_sync_flush(&peer->gossip_client);
status_failed(WIRE_CHANNEL_PEER_READ_FAILED,
"peer connection broken: %s", strerror(errno));
}
static void init_channel(struct peer *peer, const u8 *msg)
{
struct privkey seed;
struct basepoints points[NUM_SIDES];
u32 feerate;
u64 funding_satoshi, push_msat;
u16 funding_txout;
struct pubkey funding_pubkey[NUM_SIDES];
struct sha256_double funding_txid;
bool am_funder;
if (!fromwire_channel_init(msg, NULL,
&funding_txid, &funding_txout,
&peer->conf[LOCAL], &peer->conf[REMOTE],
&peer->their_commit_sig,
&peer->pcs.cs,
&funding_pubkey[REMOTE],
&points[REMOTE].revocation,
&points[REMOTE].payment,
&points[REMOTE].delayed_payment,
&peer->old_per_commit[REMOTE],
&am_funder,
&feerate, &funding_satoshi, &push_msat,
&seed,
&peer->node_ids[LOCAL],
&peer->node_ids[REMOTE],
&peer->commit_msec))
status_failed(WIRE_CHANNEL_BAD_COMMAND, "%s",
tal_hex(msg, msg));
/* We derive everything from the one secret seed. */
derive_basepoints(&seed, &funding_pubkey[LOCAL], &points[LOCAL],
&peer->our_secrets, &peer->shaseed,
&peer->old_per_commit[LOCAL],
peer->commit_index[LOCAL]);
status_trace("First per_commit_point = %s",
type_to_string(trc, struct pubkey,
&peer->old_per_commit[LOCAL]));
peer->channel = new_channel(peer, &funding_txid, funding_txout,
funding_satoshi, push_msat, feerate,
&peer->conf[LOCAL], &peer->conf[REMOTE],
&points[LOCAL], &points[REMOTE],
&funding_pubkey[LOCAL],
&funding_pubkey[REMOTE],
am_funder ? LOCAL : REMOTE);
peer->channel_direction = get_channel_direction(
&peer->node_ids[LOCAL], &peer->node_ids[REMOTE]);
/* OK, now we can process peer messages. */
peer->peer_conn = io_new_conn(peer, PEER_FD, setup_peer_conn, peer);
io_set_finish(peer->peer_conn, peer_conn_broken, peer);
}
static void handle_funding_locked(struct peer *peer, const u8 *msg)
{
if (!fromwire_channel_funding_locked(msg, NULL,
&peer->short_channel_ids[LOCAL]))
status_failed(WIRE_CHANNEL_BAD_COMMAND, "%s", tal_hex(msg, msg));
next_per_commit_point(&peer->shaseed, NULL,
&peer->current_per_commit[LOCAL],
peer->commit_index[LOCAL]++);
msg = towire_funding_locked(peer,
&peer->channel_id,
&peer->current_per_commit[LOCAL]);
msg_enqueue(&peer->peer_out, take(msg));
peer->funding_locked[LOCAL] = true;
if (peer->funding_locked[REMOTE]) {
send_channel_announcement(peer);
send_channel_update(peer, false);
daemon_conn_send(&peer->master,
take(towire_channel_normal_operation(peer)));
}
}
static void handle_funding_announce_depth(struct peer *peer, const u8 *msg)
{
status_trace("Exchanging announcement signatures.");
send_announcement_signatures(peer);
}
static void handle_offer_htlc(struct peer *peer, const u8 *inmsg)
{
u8 *msg;
u32 amount_msat, cltv_expiry;
struct sha256 payment_hash;
u8 onion_routing_packet[1254];
enum onion_type failcode;
/* Subtle: must be tal_arr since we marshal using tal_len() */
const char *failmsg;
if (!peer->funding_locked[LOCAL] || !peer->funding_locked[REMOTE])
status_failed(WIRE_CHANNEL_BAD_COMMAND, "funding not locked");
if (!fromwire_channel_offer_htlc(inmsg, NULL, &amount_msat,
&cltv_expiry, &payment_hash,
onion_routing_packet))
status_failed(WIRE_CHANNEL_BAD_COMMAND,
"bad offer_htlc message %s",
tal_hex(inmsg, inmsg));
switch (channel_add_htlc(peer->channel, LOCAL, peer->htlc_id,
amount_msat, cltv_expiry, &payment_hash,
onion_routing_packet)) {
case CHANNEL_ERR_ADD_OK:
/* Tell the peer. */
msg = towire_update_add_htlc(peer, &peer->channel_id,
peer->htlc_id, amount_msat,
cltv_expiry, &payment_hash,
onion_routing_packet);
msg_enqueue(&peer->peer_out, take(msg));
peer->funding_locked[LOCAL] = true;
start_commit_timer(peer);
/* Tell the master. */
msg = towire_channel_offer_htlc_reply(inmsg, peer->htlc_id,
0, NULL);
daemon_conn_send(&peer->master, take(msg));
peer->htlc_id++;
return;
case CHANNEL_ERR_INVALID_EXPIRY:
failcode = WIRE_INCORRECT_CLTV_EXPIRY;
failmsg = tal_fmt(inmsg, "Invalid cltv_expiry %u", cltv_expiry);
goto failed;
case CHANNEL_ERR_DUPLICATE:
case CHANNEL_ERR_DUPLICATE_ID_DIFFERENT:
status_failed(WIRE_CHANNEL_BAD_COMMAND,
"Duplicate HTLC %"PRIu64, peer->htlc_id);
/* FIXME: Fuzz the boundaries a bit to avoid probing? */
case CHANNEL_ERR_MAX_HTLC_VALUE_EXCEEDED:
/* FIXME: We should advertise this? */
failcode = WIRE_TEMPORARY_CHANNEL_FAILURE;
failmsg = tal_fmt(inmsg, "Maximum value exceeded");
goto failed;
case CHANNEL_ERR_CHANNEL_CAPACITY_EXCEEDED:
failcode = WIRE_TEMPORARY_CHANNEL_FAILURE;
failmsg = tal_fmt(inmsg, "Capacity exceeded");
goto failed;
case CHANNEL_ERR_HTLC_BELOW_MINIMUM:
failcode = WIRE_AMOUNT_BELOW_MINIMUM;
failmsg = tal_fmt(inmsg, "HTLC too small (%u minimum)",
htlc_minimum_msat(peer->channel, REMOTE));
goto failed;
case CHANNEL_ERR_TOO_MANY_HTLCS:
failcode = WIRE_TEMPORARY_CHANNEL_FAILURE;
failmsg = tal_fmt(inmsg, "Too many HTLCs");
goto failed;
}
/* Shouldn't return anything else! */
abort();
failed:
msg = towire_channel_offer_htlc_reply(inmsg, 0, failcode, (u8*)failmsg);
daemon_conn_send(&peer->master, take(msg));
}
static void handle_preimage(struct peer *peer, const u8 *inmsg)
{
u8 *msg;
u64 id;
struct preimage preimage;
if (!fromwire_channel_fulfill_htlc(inmsg, NULL, &id, &preimage))
status_failed(WIRE_CHANNEL_BAD_COMMAND,
"Invalid channel_fulfill_htlc");
switch (channel_fulfill_htlc(peer->channel, REMOTE, id, &preimage)) {
case CHANNEL_ERR_REMOVE_OK:
msg = towire_update_fulfill_htlc(peer, &peer->channel_id,
id, &preimage);
msg_enqueue(&peer->peer_out, take(msg));
start_commit_timer(peer);
return;
/* These shouldn't happen, because any offered HTLC (which would give
* us the preimage) should have timed out long before. If we
* were to get preimages from other sources, this could happen. */
case CHANNEL_ERR_NO_SUCH_ID:
case CHANNEL_ERR_ALREADY_FULFILLED:
case CHANNEL_ERR_HTLC_UNCOMMITTED:
case CHANNEL_ERR_HTLC_NOT_IRREVOCABLE:
case CHANNEL_ERR_BAD_PREIMAGE:
status_failed(WIRE_CHANNEL_BAD_COMMAND,
"HTLC %"PRIu64" preimage failed", id);
}
abort();
}
static void handle_fail(struct peer *peer, const u8 *inmsg)
{
u8 *msg;
u64 id;
u8 *errpkt;
if (!fromwire_channel_fail_htlc(inmsg, inmsg, NULL, &id, &errpkt))
status_failed(WIRE_CHANNEL_BAD_COMMAND,
"Invalid channel_fail_htlc");
switch (channel_fail_htlc(peer->channel, REMOTE, id)) {
case CHANNEL_ERR_REMOVE_OK:
msg = towire_update_fail_htlc(peer, &peer->channel_id,
id, errpkt);
msg_enqueue(&peer->peer_out, take(msg));
start_commit_timer(peer);
return;
/* These shouldn't happen, because any offered HTLC (which would give
* us the preimage) should have timed out long before. If we
* were to get preimages from other sources, this could happen. */
case CHANNEL_ERR_NO_SUCH_ID:
case CHANNEL_ERR_ALREADY_FULFILLED:
case CHANNEL_ERR_HTLC_UNCOMMITTED:
case CHANNEL_ERR_HTLC_NOT_IRREVOCABLE:
case CHANNEL_ERR_BAD_PREIMAGE:
status_failed(WIRE_CHANNEL_BAD_COMMAND,
"HTLC %"PRIu64" preimage failed", id);
}
abort();
}
static struct io_plan *req_in(struct io_conn *conn, struct daemon_conn *master)
{
struct peer *peer = container_of(master, struct peer, master);
if (!peer->channel)
init_channel(peer, master->msg_in);
else {
enum channel_wire_type t = fromwire_peektype(master->msg_in);
switch (t) {
case WIRE_CHANNEL_FUNDING_LOCKED:
handle_funding_locked(peer, master->msg_in);
goto out;
case WIRE_CHANNEL_FUNDING_ANNOUNCE_DEPTH:
handle_funding_announce_depth(peer, master->msg_in);
goto out;
case WIRE_CHANNEL_OFFER_HTLC:
handle_offer_htlc(peer, master->msg_in);
goto out;
case WIRE_CHANNEL_FULFILL_HTLC:
handle_preimage(peer, master->msg_in);
goto out;
case WIRE_CHANNEL_FAIL_HTLC:
handle_fail(peer, master->msg_in);
goto out;
case WIRE_CHANNEL_BAD_COMMAND:
case WIRE_CHANNEL_HSM_FAILED:
case WIRE_CHANNEL_CRYPTO_FAILED:
case WIRE_CHANNEL_PEER_WRITE_FAILED:
case WIRE_CHANNEL_PEER_READ_FAILED:
case WIRE_CHANNEL_RECEIVED_FUNDING_LOCKED:
case WIRE_CHANNEL_NORMAL_OPERATION:
case WIRE_CHANNEL_INIT:
case WIRE_CHANNEL_OFFER_HTLC_REPLY:
case WIRE_CHANNEL_ACCEPTED_HTLC:
case WIRE_CHANNEL_FULFILLED_HTLC:
case WIRE_CHANNEL_FAILED_HTLC:
case WIRE_CHANNEL_MALFORMED_HTLC:
case WIRE_CHANNEL_PEER_BAD_MESSAGE:
break;
}
status_failed(WIRE_CHANNEL_BAD_COMMAND, "%s", strerror(errno));
}
out:
return daemon_conn_read_next(conn, master);
}
#ifndef TESTING
int main(int argc, char *argv[])
{
struct peer *peer = tal(NULL, struct peer);
if (argc == 2 && streq(argv[1], "--version")) {
printf("%s\n", version());
exit(0);
}
subdaemon_debug(argc, argv);
/* We handle write returning errors! */
signal(SIGCHLD, SIG_IGN);
secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY
| SECP256K1_CONTEXT_SIGN);
daemon_conn_init(peer, &peer->master, REQ_FD, req_in);
peer->channel = NULL;
peer->htlc_id = 0;
timers_init(&peer->timers, time_mono());
peer->commit_timer = NULL;
peer->commit_index[LOCAL] = peer->commit_index[REMOTE] = 0;
shachain_init(&peer->their_shachain);
status_setup_async(&peer->master);
msg_queue_init(&peer->peer_out, peer);
daemon_conn_init(peer, &peer->gossip_client, GOSSIP_FD,
gossip_client_recv);
init_peer_crypto_state(peer, &peer->pcs);
peer->funding_locked[LOCAL] = peer->funding_locked[REMOTE] = false;
for (;;) {
struct timer *expired = NULL;
io_loop(&peer->timers, &expired);
if (!expired)
break;
timer_expired(peer, expired);
}
tal_free(peer);
return 0;
}
#endif /* TESTING */