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lightning/channeld/channel.c

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/* Main channel operation daemon: runs from funding_locked to shutdown_complete.
*
* We're fairly synchronous: our main loop looks for gossip, master or
* peer requests and services them synchronously.
*
* The exceptions are:
* 1. When we've asked the master something: in that case, we queue
* non-response packets for later processing while we await the reply.
* 2. We queue and send non-blocking responses to peers: if both peers were
* reading and writing synchronously we could deadlock if we hit buffer
* limits, unlikely as that is.
*/
#include <bitcoin/privkey.h>
#include <bitcoin/script.h>
#include <ccan/cast/cast.h>
#include <ccan/container_of/container_of.h>
#include <ccan/crypto/hkdf_sha256/hkdf_sha256.h>
#include <ccan/crypto/shachain/shachain.h>
#include <ccan/err/err.h>
#include <ccan/fdpass/fdpass.h>
#include <ccan/mem/mem.h>
#include <ccan/structeq/structeq.h>
#include <ccan/take/take.h>
#include <ccan/tal/str/str.h>
#include <ccan/time/time.h>
#include <channeld/commit_tx.h>
#include <channeld/full_channel.h>
#include <channeld/gen_channel_wire.h>
#include <common/crypto_sync.h>
#include <common/derive_basepoints.h>
#include <common/dev_disconnect.h>
#include <common/htlc_tx.h>
#include <common/key_derive.h>
#include <common/msg_queue.h>
#include <common/peer_billboard.h>
#include <common/peer_failed.h>
#include <common/ping.h>
#include <common/read_peer_msg.h>
#include <common/sphinx.h>
#include <common/status.h>
#include <common/subdaemon.h>
#include <common/timeout.h>
#include <common/type_to_string.h>
#include <common/version.h>
#include <common/wire_error.h>
#include <errno.h>
#include <fcntl.h>
#include <gossipd/gen_gossip_wire.h>
#include <gossipd/gossip_constants.h>
#include <hsmd/gen_hsm_client_wire.h>
#include <inttypes.h>
#include <secp256k1.h>
#include <stdio.h>
#include <wire/gen_onion_wire.h>
#include <wire/peer_wire.h>
#include <wire/wire.h>
#include <wire/wire_io.h>
#include <wire/wire_sync.h>
/* stdin == requests, 3 == peer, 4 = gossip, 5 = HSM */
#define MASTER_FD STDIN_FILENO
#define PEER_FD 3
#define GOSSIP_FD 4
#define HSM_FD 5
struct commit_sigs {
struct peer *peer;
secp256k1_ecdsa_signature commit_sig;
secp256k1_ecdsa_signature *htlc_sigs;
};
struct peer {
struct crypto_state cs;
struct channel_config conf[NUM_SIDES];
bool funding_locked[NUM_SIDES];
u64 next_index[NUM_SIDES];
/* Tolerable amounts for feerate (only relevant for fundee). */
u32 feerate_min, feerate_max;
/* Remote's current per-commit point. */
struct pubkey remote_per_commit;
/* Remotes's last per-commitment point: we keep this to check
* revoke_and_ack's `per_commitment_secret` is correct. */
struct pubkey old_remote_per_commit;
/* Their sig for current commit. */
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;
/* BOLT #2:
*
* A sending node:
*...
* - for the first HTLC it offers:
* - MUST set `id` to 0.
*/
u64 htlc_id;
struct bitcoin_blkid chain_hash;
struct channel_id channel_id;
struct channel *channel;
/* Pending msgs to send (not encrypted) */
struct msg_queue peer_out;
/* Current msg to send, and offset (encrypted) */
const u8 *peer_outmsg;
size_t peer_outoff;
/* Messages from master / gossipd: we queue them since we
* might be waiting for a specific reply. */
struct msg_queue from_master, from_gossipd;
struct timers timers;
struct oneshot *commit_timer;
u64 commit_timer_attempts;
u32 commit_msec;
/* Don't accept a pong we didn't ping for. */
size_t num_pings_outstanding;
/* The feerate we want. */
u32 desired_feerate;
/* 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];
bool have_sigs[NUM_SIDES];
/* Which direction of the channel do we control? */
u16 channel_direction;
/* CLTV delta to announce to peers */
u16 cltv_delta;
u32 fee_base;
u32 fee_per_satoshi;
/* We save calculated commit sigs while waiting for master approval */
struct commit_sigs *next_commit_sigs;
/* The scriptpubkey to use for shutting down. */
u8 *final_scriptpubkey;
/* If master told us to shut down */
bool send_shutdown;
/* Has shutdown been sent by each side? */
bool shutdown_sent[NUM_SIDES];
/* Information used for reestablishment. */
bool last_was_revoke;
struct changed_htlc *last_sent_commit;
u64 revocations_received;
u8 channel_flags;
bool announce_depth_reached;
bool channel_local_active;
/* Make sure timestamps move forward. */
u32 last_update_timestamp;
};
static u8 *create_channel_announcement(const tal_t *ctx, struct peer *peer);
static void start_commit_timer(struct peer *peer);
static void billboard_update(const struct peer *peer)
{
const char *funding_status, *announce_status, *shutdown_status;
if (peer->funding_locked[LOCAL] && peer->funding_locked[REMOTE])
funding_status = "Funding transaction locked.";
else if (!peer->funding_locked[LOCAL] && !peer->funding_locked[REMOTE])
/* FIXME: Say how many blocks to go! */
funding_status = "Funding needs more confirmations.";
else if (peer->funding_locked[LOCAL] && !peer->funding_locked[REMOTE])
funding_status = "We've confirmed funding, they haven't yet.";
else if (!peer->funding_locked[LOCAL] && peer->funding_locked[REMOTE])
funding_status = "They've confirmed funding, we haven't yet.";
if (peer->have_sigs[LOCAL] && peer->have_sigs[REMOTE])
announce_status = " Channel announced.";
else if (peer->have_sigs[LOCAL] && !peer->have_sigs[REMOTE])
announce_status = " Waiting for their announcement signatures.";
else if (!peer->have_sigs[LOCAL] && peer->have_sigs[REMOTE])
announce_status = " They need our announcement signatures.";
else if (!peer->have_sigs[LOCAL] && !peer->have_sigs[REMOTE])
announce_status = "";
if (!peer->shutdown_sent[LOCAL] && !peer->shutdown_sent[REMOTE])
shutdown_status = "";
else if (!peer->shutdown_sent[LOCAL] && peer->shutdown_sent[REMOTE])
shutdown_status = " We've send shutdown, waiting for theirs";
else if (peer->shutdown_sent[LOCAL] && !peer->shutdown_sent[REMOTE])
shutdown_status = " They've sent shutdown, waiting for ours";
else if (peer->shutdown_sent[LOCAL] && peer->shutdown_sent[REMOTE]) {
size_t num_htlcs = num_channel_htlcs(peer->channel);
if (num_htlcs)
shutdown_status = tal_fmt(tmpctx,
" Shutdown messages exchanged,"
" waiting for %zu HTLCs to complete.",
num_htlcs);
else
shutdown_status = tal_fmt(tmpctx,
" Shutdown messages exchanged.");
}
peer_billboard(false, "%s%s%s", funding_status,
announce_status, shutdown_status);
}
/* Returns a pointer to the new end */
static void *tal_arr_append_(void **p, size_t size)
{
size_t n = tal_len(*p) / size;
tal_resize_(p, size, n+1, false);
return (char *)(*p) + n * size;
}
#define tal_arr_append(p) tal_arr_append_((void **)(p), sizeof(**(p)))
static void do_peer_write(struct peer *peer)
{
int r;
size_t len = tal_len(peer->peer_outmsg);
r = write(PEER_FD, peer->peer_outmsg + peer->peer_outoff,
len - peer->peer_outoff);
if (r < 0)
peer_failed_connection_lost();
peer->peer_outoff += r;
if (peer->peer_outoff == len)
peer->peer_outmsg = tal_free(peer->peer_outmsg);
}
static bool peer_write_pending(struct peer *peer)
{
const u8 *msg;
if (peer->peer_outmsg)
return true;
msg = msg_dequeue(&peer->peer_out);
if (!msg)
return false;
status_peer_io(LOG_IO_OUT, msg);
peer->peer_outmsg = cryptomsg_encrypt_msg(peer, &peer->cs, take(msg));
peer->peer_outoff = 0;
return true;
}
/* Synchronous flush of all pending packets. */
static void flush_peer_out(struct peer *peer)
{
while (peer_write_pending(peer))
do_peer_write(peer);
}
static void enqueue_peer_msg(struct peer *peer, const u8 *msg TAKES)
{
#if DEVELOPER
enum dev_disconnect d = dev_disconnect(fromwire_peektype(msg));
/* We want to effect this exact packet, so flush any pending. */
if (d != DEV_DISCONNECT_NORMAL)
flush_peer_out(peer);
switch (d) {
case DEV_DISCONNECT_BEFORE:
/* Fail immediately. */
dev_sabotage_fd(PEER_FD);
msg_enqueue(&peer->peer_out, msg);
flush_peer_out(peer);
/* Should not return */
abort();
case DEV_DISCONNECT_DROPPKT:
tal_free(msg);
/* Fail next time we try to do something. */
dev_sabotage_fd(PEER_FD);
return;
case DEV_DISCONNECT_AFTER:
msg_enqueue(&peer->peer_out, msg);
flush_peer_out(peer);
dev_sabotage_fd(PEER_FD);
return;
case DEV_DISCONNECT_BLACKHOLE:
msg_enqueue(&peer->peer_out, msg);
dev_blackhole_fd(PEER_FD);
return;
case DEV_DISCONNECT_NORMAL:
break;
}
#endif
msg_enqueue(&peer->peer_out, msg);
}
/* Create and send channel_update to gossipd (and maybe peer) */
static void send_channel_update(struct peer *peer, int disable_flag)
{
u8 *msg;
assert(disable_flag == 0 || disable_flag == ROUTING_FLAGS_DISABLED);
/* Only send an update if we told gossipd */
if (!peer->channel_local_active)
return;
assert(peer->short_channel_ids[LOCAL].u64);
msg = towire_gossip_local_channel_update(NULL,
&peer->short_channel_ids[LOCAL],
disable_flag
== ROUTING_FLAGS_DISABLED,
peer->cltv_delta,
peer->conf[REMOTE].htlc_minimum_msat,
peer->fee_base,
peer->fee_per_satoshi);
wire_sync_write(GOSSIP_FD, take(msg));
}
/**
* Add a channel locally and send a channel update to the peer
*
* Send a local_add_channel message to gossipd in order to make the channel
* usable locally, and also tell our peer about our parameters via a
* channel_update message. The peer may accept the update and use the contained
* information to route incoming payments through the channel. The
* channel_update is not preceeded by a channel_announcement and won't make much
* sense to other nodes, so we don't tell gossipd about it.
*/
static void make_channel_local_active(struct peer *peer)
{
u8 *msg;
/* Tell gossipd about local channel. */
msg = towire_gossip_local_add_channel(NULL,
&peer->short_channel_ids[LOCAL],
&peer->node_ids[REMOTE]);
wire_sync_write(GOSSIP_FD, take(msg));
/* Tell gossipd and the other side what parameters we expect should
* they route through us */
send_channel_update(peer, 0);
}
static void send_announcement_signatures(struct peer *peer)
{
/* First 2 + 256 byte are the signatures and msg type, skip them */
size_t offset = 258;
struct sha256_double hash;
u8 *msg, *ca, *req;
status_trace("Exchanging announcement signatures.");
ca = create_channel_announcement(tmpctx, peer);
req = towire_hsm_cannouncement_sig_req(
tmpctx, &peer->channel->funding_pubkey[LOCAL], ca);
if (!wire_sync_write(HSM_FD, req))
status_failed(STATUS_FAIL_HSM_IO,
"Writing cannouncement_sig_req: %s",
strerror(errno));
msg = wire_sync_read(tmpctx, HSM_FD);
if (!msg || !fromwire_hsm_cannouncement_sig_reply(msg,
&peer->announcement_node_sigs[LOCAL]))
status_failed(STATUS_FAIL_HSM_IO,
"Reading cannouncement_sig_resp: %s",
strerror(errno));
/* Double-check that HSM gave a valid signature. */
sha256_double(&hash, ca + offset, tal_len(ca) - offset);
if (!check_signed_hash(&hash, &peer->announcement_node_sigs[LOCAL],
&peer->node_ids[LOCAL])) {
/* It's ok to fail here, the channel announcement is
* unique, unlike the channel update which may have
* been replaced in the meantime. */
status_failed(STATUS_FAIL_HSM_IO,
"HSM returned an invalid signature");
}
/* TODO(cdecker) Move this to the HSM once we store the
* funding_privkey there */
sign_hash(&peer->our_secrets.funding_privkey, &hash,
&peer->announcement_bitcoin_sigs[LOCAL]);
msg = towire_announcement_signatures(
NULL, &peer->channel_id, &peer->short_channel_ids[LOCAL],
&peer->announcement_node_sigs[LOCAL],
&peer->announcement_bitcoin_sigs[LOCAL]);
enqueue_peer_msg(peer, take(msg));
}
/* Tentatively create a channel_announcement, possibly with invalid
* signatures. The signatures need to be collected first, by asking
* the HSM and by exchanging announcement_signature messages. */
static u8 *create_channel_announcement(const tal_t *ctx, struct peer *peer)
{
int first, second;
u8 *cannounce, *features = tal_arr(ctx, u8, 0);
if (peer->channel_direction == 0) {
first = LOCAL;
second = REMOTE;
} else {
first = REMOTE;
second = LOCAL;
}
cannounce = towire_channel_announcement(
ctx, &peer->announcement_node_sigs[first],
&peer->announcement_node_sigs[second],
&peer->announcement_bitcoin_sigs[first],
&peer->announcement_bitcoin_sigs[second],
features,
&peer->chain_hash,
&peer->short_channel_ids[LOCAL], &peer->node_ids[first],
&peer->node_ids[second], &peer->channel->funding_pubkey[first],
&peer->channel->funding_pubkey[second]);
tal_free(features);
return cannounce;
}
/* Once we have both, we'd better make sure we agree what they are! */
static void check_short_ids_match(struct peer *peer)
{
assert(peer->have_sigs[LOCAL]);
assert(peer->have_sigs[REMOTE]);
if (!structeq(&peer->short_channel_ids[LOCAL],
&peer->short_channel_ids[REMOTE]))
peer_failed(&peer->cs,
&peer->channel_id,
"We disagree on short_channel_ids:"
" I have %s, you say %s",
type_to_string(peer, struct short_channel_id,
&peer->short_channel_ids[LOCAL]),
type_to_string(peer, struct short_channel_id,
&peer->short_channel_ids[REMOTE]));
}
static void announce_channel(struct peer *peer)
{
u8 *cannounce;
check_short_ids_match(peer);
cannounce = create_channel_announcement(tmpctx, peer);
wire_sync_write(GOSSIP_FD, cannounce);
send_channel_update(peer, 0);
}
static void channel_announcement_negotiate(struct peer *peer)
{
/* Don't do any announcement work if we're shutting down */
if (peer->shutdown_sent[LOCAL])
return;
/* Can't do anything until funding is locked. */
if (!peer->funding_locked[LOCAL] || !peer->funding_locked[REMOTE])
return;
if (!peer->channel_local_active) {
peer->channel_local_active = true;
make_channel_local_active(peer);
}
/* BOLT #7:
*
* - MUST NOT send `announcement_signatures` messages until
* `funding_locked` has been sent AND the funding transaction has
* at least six confirmations.
*/
if (peer->announce_depth_reached && !peer->have_sigs[LOCAL]) {
send_announcement_signatures(peer);
peer->have_sigs[LOCAL] = true;
billboard_update(peer);
}
/* If we've completed the signature exchange, we can send a real
* announcement, otherwise we send a temporary one */
if (peer->have_sigs[LOCAL] && peer->have_sigs[REMOTE])
announce_channel(peer);
}
static void handle_peer_funding_locked(struct peer *peer, const u8 *msg)
{
struct channel_id chanid;
/* BOLT #2:
*
* A node:
*...
* - upon reconnection:
* - MUST ignore any redundant `funding_locked` it receives.
*/
if (peer->funding_locked[REMOTE])
return;
/* Too late, we're shutting down! */
if (peer->shutdown_sent[LOCAL])
return;
peer->old_remote_per_commit = peer->remote_per_commit;
if (!fromwire_funding_locked(msg, &chanid,
&peer->remote_per_commit))
peer_failed(&peer->cs,
&peer->channel_id,
"Bad funding_locked %s", tal_hex(msg, msg));
if (!structeq(&chanid, &peer->channel_id))
peer_failed(&peer->cs,
&peer->channel_id,
"Wrong channel id in %s (expected %s)",
tal_hex(tmpctx, msg),
type_to_string(msg, struct channel_id,
&peer->channel_id));
peer->funding_locked[REMOTE] = true;
wire_sync_write(MASTER_FD,
take(towire_channel_got_funding_locked(NULL,
&peer->remote_per_commit)));
channel_announcement_negotiate(peer);
billboard_update(peer);
}
static void handle_peer_announcement_signatures(struct peer *peer, const u8 *msg)
{
struct channel_id chanid;
if (!fromwire_announcement_signatures(msg,
&chanid,
&peer->short_channel_ids[REMOTE],
&peer->announcement_node_sigs[REMOTE],
&peer->announcement_bitcoin_sigs[REMOTE]))
peer_failed(&peer->cs,
&peer->channel_id,
"Bad announcement_signatures %s",
tal_hex(msg, msg));
/* Make sure we agree on the channel ids */
if (!structeq(&chanid, &peer->channel_id)) {
peer_failed(&peer->cs,
&peer->channel_id,
"Wrong channel_id: expected %s, got %s",
type_to_string(tmpctx, struct channel_id,
&peer->channel_id),
type_to_string(tmpctx, struct channel_id, &chanid));
}
peer->have_sigs[REMOTE] = true;
billboard_update(peer);
channel_announcement_negotiate(peer);
}
static bool get_shared_secret(const struct htlc *htlc,
struct secret *shared_secret)
{
struct pubkey ephemeral;
struct onionpacket *op;
u8 *msg;
/* We unwrap the onion now. */
op = parse_onionpacket(tmpctx, htlc->routing, TOTAL_PACKET_SIZE);
if (!op) {
/* Return an invalid shared secret. */
memset(shared_secret, 0, sizeof(*shared_secret));
return false;
}
/* Because wire takes struct pubkey. */
ephemeral.pubkey = op->ephemeralkey;
msg = towire_hsm_ecdh_req(tmpctx, &ephemeral);
if (!wire_sync_write(HSM_FD, msg))
status_failed(STATUS_FAIL_HSM_IO, "Writing ecdh req");
msg = wire_sync_read(tmpctx, HSM_FD);
/* Gives all-zero shares_secret if it was invalid. */
if (!msg || !fromwire_hsm_ecdh_resp(msg, shared_secret))
status_failed(STATUS_FAIL_HSM_IO, "Reading ecdh response");
return !memeqzero(shared_secret, sizeof(*shared_secret));
}
static void handle_peer_add_htlc(struct peer *peer, const u8 *msg)
{
struct channel_id channel_id;
u64 id;
u64 amount_msat;
u32 cltv_expiry;
struct sha256 payment_hash;
u8 onion_routing_packet[TOTAL_PACKET_SIZE];
enum channel_add_err add_err;
struct htlc *htlc;
if (!fromwire_update_add_htlc(msg, &channel_id, &id, &amount_msat,
&payment_hash, &cltv_expiry,
onion_routing_packet))
peer_failed(&peer->cs,
&peer->channel_id,
"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, &htlc);
if (add_err != CHANNEL_ERR_ADD_OK)
peer_failed(&peer->cs,
&peer->channel_id,
"Bad peer_add_htlc: %s",
channel_add_err_name(add_err));
/* If this is wrong, we don't complain yet; when it's confirmed we'll
* send it to the master which handles all HTLC failures. */
htlc->shared_secret = tal(htlc, struct secret);
get_shared_secret(htlc, htlc->shared_secret);
}
static void handle_peer_feechange(struct peer *peer, const u8 *msg)
{
struct channel_id channel_id;
u32 feerate;
if (!fromwire_update_fee(msg, &channel_id, &feerate)) {
peer_failed(&peer->cs,
&peer->channel_id,
"Bad update_fee %s", tal_hex(msg, msg));
}
/* BOLT #2:
*
* A receiving node:
*...
* - if the sender is not responsible for paying the Bitcoin fee:
* - MUST fail the channel.
*/
if (peer->channel->funder != REMOTE)
peer_failed(&peer->cs,
&peer->channel_id,
"update_fee from non-funder?");
status_trace("update_fee %u, range %u-%u",
feerate, peer->feerate_min, peer->feerate_max);
/* BOLT #2:
*
* A receiving node:
* - if the `update_fee` is too low for timely processing, OR is
* unreasonably large:
* - SHOULD fail the channel.
*/
if (feerate < peer->feerate_min || feerate > peer->feerate_max)
peer_failed(&peer->cs,
&peer->channel_id,
"update_fee %u outside range %u-%u",
feerate, peer->feerate_min, peer->feerate_max);
/* BOLT #2:
*
* - if the sender cannot afford the new fee rate on the receiving
* node's current commitment transaction:
* - SHOULD fail the channel,
* - but MAY delay this check until the `update_fee` is committed.
*/
if (!channel_update_feerate(peer->channel, feerate))
peer_failed(&peer->cs,
&peer->channel_id,
"update_fee %u unaffordable",
feerate);
status_trace("peer updated fee to %u", feerate);
}
static struct changed_htlc *changed_htlc_arr(const tal_t *ctx,
const struct htlc **changed_htlcs)
{
struct changed_htlc *changed;
size_t i;
changed = tal_arr(ctx, struct changed_htlc, tal_count(changed_htlcs));
for (i = 0; i < tal_count(changed_htlcs); i++) {
changed[i].id = changed_htlcs[i]->id;
changed[i].newstate = changed_htlcs[i]->state;
}
return changed;
}
static u8 *sending_commitsig_msg(const tal_t *ctx,
u64 remote_commit_index,
u32 remote_feerate,
const struct htlc **changed_htlcs,
const secp256k1_ecdsa_signature *commit_sig,
const secp256k1_ecdsa_signature *htlc_sigs)
{
struct changed_htlc *changed;
u8 *msg;
/* We tell master what (of our) HTLCs peer will now be
* committed to. */
changed = changed_htlc_arr(tmpctx, changed_htlcs);
msg = towire_channel_sending_commitsig(ctx, remote_commit_index,
remote_feerate,
changed, commit_sig, htlc_sigs);
return msg;
}
static bool shutdown_complete(const struct peer *peer)
{
return peer->shutdown_sent[LOCAL]
&& peer->shutdown_sent[REMOTE]
&& num_channel_htlcs(peer->channel) == 0
/* We could be awaiting revoke-and-ack for a feechange */
&& peer->revocations_received == peer->next_index[REMOTE] - 1;
}
/* BOLT #2:
*
* A sending node:
*...
* - if there are updates pending on the receiving node's commitment
* transaction:
* - MUST NOT send a `shutdown`.
*/
/* So we only call this after reestablish or immediately after sending commit */
static void maybe_send_shutdown(struct peer *peer)
{
u8 *msg;
if (!peer->send_shutdown)
return;
/* Send a disable channel_update so others don't try to route
* over us */
send_channel_update(peer, ROUTING_FLAGS_DISABLED);
msg = towire_shutdown(NULL, &peer->channel_id, peer->final_scriptpubkey);
enqueue_peer_msg(peer, take(msg));
peer->send_shutdown = false;
peer->shutdown_sent[LOCAL] = true;
billboard_update(peer);
}
/* This queues other traffic from the fd until we get reply. */
static u8 *wait_sync_reply(const tal_t *ctx,
const u8 *msg,
int replytype,
int fd,
struct msg_queue *queue,
const char *who)
{
u8 *reply;
status_trace("Sending %s %u", who, fromwire_peektype(msg));
if (!wire_sync_write(fd, msg))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Could not set sync write to %s: %s",
who, strerror(errno));
status_trace("... , awaiting %u", replytype);
for (;;) {
reply = wire_sync_read(ctx, fd);
if (!reply)
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Could not set sync read from %s: %s",
who, strerror(errno));
if (fromwire_peektype(reply) == replytype) {
status_trace("Got it!");
break;
}
status_trace("Nope, got %u instead", fromwire_peektype(reply));
msg_enqueue(queue, take(reply));
}
return reply;
}
static u8 *master_wait_sync_reply(const tal_t *ctx,
struct peer *peer, const u8 *msg,
enum channel_wire_type replytype)
{
return wait_sync_reply(ctx, msg, replytype,
MASTER_FD, &peer->from_master, "master");
}
static u8 *gossipd_wait_sync_reply(const tal_t *ctx,
struct peer *peer, const u8 *msg,
enum gossip_wire_type replytype)
{
return wait_sync_reply(ctx, msg, replytype,
GOSSIP_FD, &peer->from_gossipd, "gossipd");
}
static struct commit_sigs *calc_commitsigs(const tal_t *ctx,
const struct peer *peer,
u64 commit_index)
{
size_t i;
struct bitcoin_tx **txs;
const u8 **wscripts;
const struct htlc **htlc_map;
struct pubkey local_htlckey;
struct privkey local_htlcsecretkey;
struct commit_sigs *commit_sigs = tal(ctx, struct commit_sigs);
if (!derive_simple_privkey(&peer->our_secrets.htlc_basepoint_secret,
&peer->channel->basepoints[LOCAL].htlc,
&peer->remote_per_commit,
&local_htlcsecretkey))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Deriving local_htlcsecretkey");
if (!derive_simple_key(&peer->channel->basepoints[LOCAL].htlc,
&peer->remote_per_commit,
&local_htlckey))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Deriving local_htlckey");
status_trace("Derived key %s from basepoint %s, point %s",
type_to_string(tmpctx, struct pubkey, &local_htlckey),
type_to_string(tmpctx, struct pubkey,
&peer->channel->basepoints[LOCAL].htlc),
type_to_string(tmpctx, struct pubkey,
&peer->remote_per_commit));
txs = channel_txs(tmpctx, &htlc_map, &wscripts, peer->channel,
&peer->remote_per_commit,
commit_index,
REMOTE);
sign_tx_input(txs[0], 0, NULL,
wscripts[0],
&peer->our_secrets.funding_privkey,
&peer->channel->funding_pubkey[LOCAL],
&commit_sigs->commit_sig);
status_trace("Creating commit_sig signature %"PRIu64" %s for tx %s wscript %s key %s",
commit_index,
type_to_string(tmpctx, secp256k1_ecdsa_signature,
&commit_sigs->commit_sig),
type_to_string(tmpctx, struct bitcoin_tx, txs[0]),
tal_hex(tmpctx, wscripts[0]),
type_to_string(tmpctx, struct pubkey,
&peer->channel->funding_pubkey[LOCAL]));
dump_htlcs(peer->channel, "Sending commit_sig");
/* BOLT #2:
*
* A sending node:
*...
* - MUST include one `htlc_signature` for every HTLC transaction
* corresponding to BIP69 lexicographic ordering of the commitment
* transaction.
*/
commit_sigs->htlc_sigs = tal_arr(commit_sigs, secp256k1_ecdsa_signature,
tal_count(txs) - 1);
for (i = 0; i < tal_count(commit_sigs->htlc_sigs); i++) {
sign_tx_input(txs[1 + i], 0,
NULL,
wscripts[1 + i],
&local_htlcsecretkey, &local_htlckey,
&commit_sigs->htlc_sigs[i]);
status_trace("Creating HTLC signature %s for tx %s wscript %s key %s",
type_to_string(tmpctx, secp256k1_ecdsa_signature,
&commit_sigs->htlc_sigs[i]),
type_to_string(tmpctx, struct bitcoin_tx, txs[1+i]),
tal_hex(tmpctx, wscripts[1+i]),
type_to_string(tmpctx, struct pubkey,
&local_htlckey));
assert(check_tx_sig(txs[1+i], 0, NULL, wscripts[1+i],
&local_htlckey,
&commit_sigs->htlc_sigs[i]));
}
return commit_sigs;
}
static void send_commit(struct peer *peer)
{
u8 *msg;
const struct htlc **changed_htlcs;
#if DEVELOPER
/* Hack to suppress all commit sends if dev_disconnect says to */
if (dev_suppress_commit) {
peer->commit_timer = NULL;
return;
}
#endif
/* FIXME: Document this requirement in BOLT 2! */
/* We can't send two commits in a row. */
if (peer->revocations_received != peer->next_index[REMOTE] - 1) {
assert(peer->revocations_received
== peer->next_index[REMOTE] - 2);
peer->commit_timer_attempts++;
/* Only report this in extreme cases */
if (peer->commit_timer_attempts % 100 == 0)
status_trace("Can't send commit:"
" waiting for revoke_and_ack with %"
PRIu64" attempts",
peer->commit_timer_attempts);
/* Mark this as done and try again. */
peer->commit_timer = NULL;
start_commit_timer(peer);
return;
}
/* BOLT #2:
*
* - if no HTLCs remain in either commitment transaction:
* - MUST NOT send any `update` message after a `shutdown`.
*/
if (peer->shutdown_sent[LOCAL] && !num_channel_htlcs(peer->channel)) {
status_trace("Can't send commit: final shutdown phase");
peer->commit_timer = NULL;
return;
}
/* If we wanted to update fees, do it now. */
if (peer->channel->funder == LOCAL
&& peer->desired_feerate != channel_feerate(peer->channel, REMOTE)) {
u8 *msg;
u32 feerate, max = approx_max_feerate(peer->channel);
feerate = peer->desired_feerate;
/* FIXME: We should avoid adding HTLCs until we can meet this
* feerate! */
if (feerate > max)
feerate = max;
if (!channel_update_feerate(peer->channel, feerate))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Could not afford feerate %u"
" (vs max %u)",
feerate, max);
msg = towire_update_fee(NULL, &peer->channel_id, feerate);
enqueue_peer_msg(peer, take(msg));
}
/* BOLT #2:
*
* A sending node:
* - MUST NOT send a `commitment_signed` message that does not include
* any updates.
*/
changed_htlcs = tal_arr(tmpctx, const struct htlc *, 0);
if (!channel_sending_commit(peer->channel, &changed_htlcs)) {
status_trace("Can't send commit: nothing to send");
/* Covers the case where we've just been told to shutdown. */
maybe_send_shutdown(peer);
peer->commit_timer = NULL;
return;
}
peer->next_commit_sigs = calc_commitsigs(peer, peer,
peer->next_index[REMOTE]);
status_trace("Telling master we're about to commit...");
/* Tell master to save this next commit to database, then wait. */
msg = sending_commitsig_msg(NULL, peer->next_index[REMOTE],
channel_feerate(peer->channel, REMOTE),
changed_htlcs,
&peer->next_commit_sigs->commit_sig,
peer->next_commit_sigs->htlc_sigs);
/* Message is empty; receiving it is the point. */
master_wait_sync_reply(tmpctx, peer, take(msg),
WIRE_CHANNEL_SENDING_COMMITSIG_REPLY);
status_trace("Sending commit_sig with %zu htlc sigs",
tal_count(peer->next_commit_sigs->htlc_sigs));
peer->next_index[REMOTE]++;
msg = towire_commitment_signed(NULL, &peer->channel_id,
&peer->next_commit_sigs->commit_sig,
peer->next_commit_sigs->htlc_sigs);
enqueue_peer_msg(peer, take(msg));
peer->next_commit_sigs = tal_free(peer->next_commit_sigs);
maybe_send_shutdown(peer);
/* Timer now considered expired, you can add a new one. */
peer->commit_timer = NULL;
start_commit_timer(peer);
}
static void start_commit_timer(struct peer *peer)
{
/* Already armed? */
if (peer->commit_timer)
return;
peer->commit_timer_attempts = 0;
peer->commit_timer = new_reltimer(&peer->timers, peer,
time_from_msec(peer->commit_msec),
send_commit, peer);
}
static u8 *make_revocation_msg(const struct peer *peer, u64 revoke_index)
{
struct pubkey oldpoint, point;
struct sha256 old_commit_secret;
/* Get secret. */
per_commit_secret(&peer->shaseed, &old_commit_secret, revoke_index);
/* Sanity check that it corresponds to the point we sent. */
pubkey_from_privkey((struct privkey *)&old_commit_secret, &point);
if (!per_commit_point(&peer->shaseed, &oldpoint, revoke_index))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Invalid point %"PRIu64" for commit_point",
revoke_index);
status_trace("Sending revocation #%"PRIu64" for %s",
revoke_index,
type_to_string(tmpctx, struct pubkey, &oldpoint));
if (!pubkey_eq(&point, &oldpoint))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Invalid secret %s for commit_point",
tal_hexstr(tmpctx, &old_commit_secret,
sizeof(old_commit_secret)));
/* We're revoking N-1th commit, sending N+1th point. */
if (!per_commit_point(&peer->shaseed, &point, revoke_index+2))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Deriving next commit_point");
return towire_revoke_and_ack(peer, &peer->channel_id, &old_commit_secret,
&point);
}
static void send_revocation(struct peer *peer)
{
/* Revoke previous commit. */
u8 *msg = make_revocation_msg(peer, peer->next_index[LOCAL]-1);
/* From now on we apply changes to the next commitment */
peer->next_index[LOCAL]++;
/* If this queues more changes on the other end, send commit. */
if (channel_sending_revoke_and_ack(peer->channel)) {
status_trace("revoke_and_ack made pending: commit timer");
start_commit_timer(peer);
}
enqueue_peer_msg(peer, take(msg));
}
static u8 *got_commitsig_msg(const tal_t *ctx,
u64 local_commit_index,
u32 local_feerate,
const secp256k1_ecdsa_signature *commit_sig,
const secp256k1_ecdsa_signature *htlc_sigs,
const struct htlc **changed_htlcs,
const struct bitcoin_tx *committx)
{
struct changed_htlc *changed;
struct fulfilled_htlc *fulfilled;
const struct failed_htlc **failed;
struct added_htlc *added;
struct secret *shared_secret;
u8 *msg;
changed = tal_arr(tmpctx, struct changed_htlc, 0);
added = tal_arr(tmpctx, struct added_htlc, 0);
shared_secret = tal_arr(tmpctx, struct secret, 0);
failed = tal_arr(tmpctx, const struct failed_htlc *, 0);
fulfilled = tal_arr(tmpctx, struct fulfilled_htlc, 0);
for (size_t i = 0; i < tal_count(changed_htlcs); i++) {
const struct htlc *htlc = changed_htlcs[i];
if (htlc->state == RCVD_ADD_COMMIT) {
struct added_htlc *a = tal_arr_append(&added);
struct secret *s = tal_arr_append(&shared_secret);
a->id = htlc->id;
a->amount_msat = htlc->msatoshi;
a->payment_hash = htlc->rhash;
a->cltv_expiry = abs_locktime_to_blocks(&htlc->expiry);
memcpy(a->onion_routing_packet,
htlc->routing,
sizeof(a->onion_routing_packet));
*s = *htlc->shared_secret;
} else if (htlc->state == RCVD_REMOVE_COMMIT) {
if (htlc->r) {
struct fulfilled_htlc *f;
assert(!htlc->fail);
f = tal_arr_append(&fulfilled);
f->id = htlc->id;
f->payment_preimage = *htlc->r;
} else {
struct failed_htlc **f;
assert(htlc->fail);
f = tal_arr_append(&failed);
*f = tal(failed, struct failed_htlc);
(*f)->id = htlc->id;
(*f)->malformed = htlc->malformed;
(*f)->failreason = cast_const(u8 *, htlc->fail);
}
} else {
struct changed_htlc *c = tal_arr_append(&changed);
assert(htlc->state == RCVD_REMOVE_ACK_COMMIT
|| htlc->state == RCVD_ADD_ACK_COMMIT);
c->id = htlc->id;
c->newstate = htlc->state;
}
}
msg = towire_channel_got_commitsig(ctx, local_commit_index,
local_feerate,
commit_sig,
htlc_sigs,
added,
shared_secret,
fulfilled,
failed,
changed,
committx);
return msg;
}
static void handle_peer_commit_sig(struct peer *peer, const u8 *msg)
{
struct channel_id channel_id;
secp256k1_ecdsa_signature commit_sig, *htlc_sigs;
struct pubkey remote_htlckey, point;
struct bitcoin_tx **txs;
const struct htlc **htlc_map, **changed_htlcs;
const u8 **wscripts;
size_t i;
changed_htlcs = tal_arr(msg, const struct htlc *, 0);
if (!channel_rcvd_commit(peer->channel, &changed_htlcs)) {
/* BOLT #2:
*
* A sending node:
* - MUST NOT send a `commitment_signed` message that does not
* include any updates.
*/
peer_failed(&peer->cs,
&peer->channel_id,
"commit_sig with no changes");
}
/* We were supposed to check this was affordable as we go. */
if (peer->channel->funder == REMOTE)
assert(can_funder_afford_feerate(peer->channel,
peer->channel->view[LOCAL]
.feerate_per_kw));
if (!fromwire_commitment_signed(tmpctx, msg,
&channel_id, &commit_sig, &htlc_sigs))
peer_failed(&peer->cs,
&peer->channel_id,
"Bad commit_sig %s", tal_hex(msg, msg));
if (!per_commit_point(&peer->shaseed, &point,
peer->next_index[LOCAL]))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Deriving per_commit_point for %"PRIu64,
peer->next_index[LOCAL]);
txs = channel_txs(tmpctx, &htlc_map, &wscripts, peer->channel,
&point, peer->next_index[LOCAL], LOCAL);
if (!derive_simple_key(&peer->channel->basepoints[REMOTE].htlc,
&point, &remote_htlckey))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Deriving remote_htlckey");
status_trace("Derived key %s from basepoint %s, point %s",
type_to_string(tmpctx, struct pubkey, &remote_htlckey),
type_to_string(tmpctx, struct pubkey,
&peer->channel->basepoints[REMOTE].htlc),
type_to_string(tmpctx, struct pubkey, &point));
/* BOLT #2:
*
* A receiving node:
* - once all pending updates are applied:
* - if `signature` is not valid for its local commitment transaction:
* - MUST fail the channel.
*/
if (!check_tx_sig(txs[0], 0, NULL, wscripts[0],
&peer->channel->funding_pubkey[REMOTE], &commit_sig)) {
dump_htlcs(peer->channel, "receiving commit_sig");
peer_failed(&peer->cs,
&peer->channel_id,
"Bad commit_sig signature %"PRIu64" %s for tx %s wscript %s key %s",
peer->next_index[LOCAL],
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:
*...
* - if `num_htlcs` is not equal to the number of HTLC outputs in the
* local commitment transaction:
* - MUST fail the channel.
*/
if (tal_count(htlc_sigs) != tal_count(txs) - 1)
peer_failed(&peer->cs,
&peer->channel_id,
"Expected %zu htlc sigs, not %zu",
tal_count(txs) - 1, tal_count(htlc_sigs));
/* BOLT #2:
*
* - if any `htlc_signature` is not valid for the corresponding HTLC
* transaction:
* - MUST fail the channel.
*/
for (i = 0; i < tal_count(htlc_sigs); i++) {
if (!check_tx_sig(txs[1+i], 0, NULL, wscripts[1+i],
&remote_htlckey, &htlc_sigs[i]))
peer_failed(&peer->cs,
&peer->channel_id,
"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,
&remote_htlckey));
}
status_trace("Received commit_sig with %zu htlc sigs",
tal_count(htlc_sigs));
/* Tell master daemon, then wait for ack. */
msg = got_commitsig_msg(NULL, peer->next_index[LOCAL],
channel_feerate(peer->channel, LOCAL),
&commit_sig, htlc_sigs, changed_htlcs, txs[0]);
master_wait_sync_reply(tmpctx, peer, take(msg),
WIRE_CHANNEL_GOT_COMMITSIG_REPLY);
return send_revocation(peer);
}
static u8 *got_revoke_msg(const tal_t *ctx, u64 revoke_num,
const struct sha256 *per_commitment_secret,
const struct pubkey *next_per_commit_point,
const struct htlc **changed_htlcs)
{
u8 *msg;
struct changed_htlc *changed = tal_arr(tmpctx, struct changed_htlc, 0);
for (size_t i = 0; i < tal_count(changed_htlcs); i++) {
struct changed_htlc *c = tal_arr_append(&changed);
const struct htlc *htlc = changed_htlcs[i];
status_trace("HTLC %"PRIu64"[%s] => %s",
htlc->id, side_to_str(htlc_owner(htlc)),
htlc_state_name(htlc->state));
c->id = changed_htlcs[i]->id;
c->newstate = changed_htlcs[i]->state;
}
msg = towire_channel_got_revoke(ctx, revoke_num, per_commitment_secret,
next_per_commit_point, changed);
return msg;
}
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;
const struct htlc **changed_htlcs = tal_arr(msg, const struct htlc *, 0);
if (!fromwire_revoke_and_ack(msg, &channel_id, &old_commit_secret,
&next_per_commit)) {
peer_failed(&peer->cs,
&peer->channel_id,
"Bad revoke_and_ack %s", tal_hex(msg, msg));
}
if (peer->revocations_received != peer->next_index[REMOTE] - 2) {
peer_failed(&peer->cs,
&peer->channel_id,
"Unexpected revoke_and_ack");
}
/* BOLT #2:
*
* A receiving node:
* - if `per_commitment_secret` does not generate the previous
* `per_commitment_point`:
* - MUST fail the channel.
*/
memcpy(&privkey, &old_commit_secret, sizeof(privkey));
if (!pubkey_from_privkey(&privkey, &per_commit_point)) {
peer_failed(&peer->cs,
&peer->channel_id,
"Bad privkey %s",
type_to_string(msg, struct privkey, &privkey));
}
if (!pubkey_eq(&per_commit_point, &peer->old_remote_per_commit)) {
peer_failed(&peer->cs,
&peer->channel_id,
"Wrong privkey %s for %"PRIu64" %s",
type_to_string(msg, struct privkey, &privkey),
peer->next_index[LOCAL]-2,
type_to_string(msg, struct pubkey,
&peer->old_remote_per_commit));
}
/* We start timer even if this returns false: we might have delayed
* commit because we were waiting for this! */
if (channel_rcvd_revoke_and_ack(peer->channel, &changed_htlcs))
status_trace("Commits outstanding after recv revoke_and_ack");
else
status_trace("No commits outstanding after recv revoke_and_ack");
/* Tell master about things this locks in, wait for response */
msg = got_revoke_msg(NULL, peer->revocations_received++,
&old_commit_secret, &next_per_commit,
changed_htlcs);
master_wait_sync_reply(tmpctx, peer, take(msg),
WIRE_CHANNEL_GOT_REVOKE_REPLY);
peer->old_remote_per_commit = peer->remote_per_commit;
peer->remote_per_commit = next_per_commit;
status_trace("revoke_and_ack %s: remote_per_commit = %s, old_remote_per_commit = %s",
side_to_str(peer->channel->funder),
type_to_string(tmpctx, struct pubkey,
&peer->remote_per_commit),
type_to_string(tmpctx, struct pubkey,
&peer->old_remote_per_commit));
start_commit_timer(peer);
}
static void handle_peer_fulfill_htlc(struct peer *peer, const u8 *msg)
{
struct channel_id channel_id;
u64 id;
struct preimage preimage;
enum channel_remove_err e;
if (!fromwire_update_fulfill_htlc(msg, &channel_id,
&id, &preimage)) {
peer_failed(&peer->cs,
&peer->channel_id,
"Bad update_fulfill_htlc %s", tal_hex(msg, msg));
}
e = channel_fulfill_htlc(peer->channel, LOCAL, id, &preimage);
switch (e) {
case CHANNEL_ERR_REMOVE_OK:
/* FIXME: We could send preimages to master immediately. */
start_commit_timer(peer);
return;
/* These shouldn't happen, because any offered HTLC (which would give
* us the preimage) should have timed out long before. If we
* were to get preimages from other sources, this could happen. */
case CHANNEL_ERR_NO_SUCH_ID:
case CHANNEL_ERR_ALREADY_FULFILLED:
case CHANNEL_ERR_HTLC_UNCOMMITTED:
case CHANNEL_ERR_HTLC_NOT_IRREVOCABLE:
case CHANNEL_ERR_BAD_PREIMAGE:
peer_failed(&peer->cs,
&peer->channel_id,
"Bad update_fulfill_htlc: failed to fulfill %"
PRIu64 " error %s", id, channel_remove_err_name(e));
}
abort();
}
static void handle_peer_fail_htlc(struct peer *peer, const u8 *msg)
{
struct channel_id channel_id;
u64 id;
enum channel_remove_err e;
u8 *reason;
struct htlc *htlc;
if (!fromwire_update_fail_htlc(msg, msg,
&channel_id, &id, &reason)) {
peer_failed(&peer->cs,
&peer->channel_id,
"Bad update_fulfill_htlc %s", tal_hex(msg, msg));
}
e = channel_fail_htlc(peer->channel, LOCAL, id, NULL);
switch (e) {
case CHANNEL_ERR_REMOVE_OK:
/* Save reason for when we tell master. */
htlc = channel_get_htlc(peer->channel, LOCAL, id);
htlc->fail = tal_steal(htlc, reason);
start_commit_timer(peer);
return;
case CHANNEL_ERR_NO_SUCH_ID:
case CHANNEL_ERR_ALREADY_FULFILLED:
case CHANNEL_ERR_HTLC_UNCOMMITTED:
case CHANNEL_ERR_HTLC_NOT_IRREVOCABLE:
case CHANNEL_ERR_BAD_PREIMAGE:
peer_failed(&peer->cs,
&peer->channel_id,
"Bad update_fail_htlc: failed to remove %"
PRIu64 " error %s", id,
channel_remove_err_name(e));
}
abort();
}
static void handle_peer_fail_malformed_htlc(struct peer *peer, const u8 *msg)
{
struct channel_id channel_id;
u64 id;
enum channel_remove_err e;
struct sha256 sha256_of_onion;
u16 failure_code;
struct htlc *htlc;
u8 *fail;
if (!fromwire_update_fail_malformed_htlc(msg, &channel_id, &id,
&sha256_of_onion,
&failure_code)) {
peer_failed(&peer->cs,
&peer->channel_id,
"Bad update_fail_malformed_htlc %s",
tal_hex(msg, msg));
}
/* BOLT #2:
*
* - if the `BADONION` bit in `failure_code` is not set for
* `update_fail_malformed_htlc`:
* - MUST fail the channel.
*/
if (!(failure_code & BADONION)) {
peer_failed(&peer->cs,
&peer->channel_id,
"Bad update_fail_malformed_htlc failure code %u",
failure_code);
}
e = channel_fail_htlc(peer->channel, LOCAL, id, &htlc);
switch (e) {
case CHANNEL_ERR_REMOVE_OK:
/* FIXME: Do this! */
/* BOLT #2:
*
* - if the `sha256_of_onion` in `update_fail_malformed_htlc`
* doesn't match the onion it sent:
* - MAY retry or choose an alternate error response.
*/
/* BOLT #2:
*
* - otherwise, a receiving node which has an outgoing HTLC
* canceled by `update_fail_malformed_htlc`:
*
* - MUST return an error in the `update_fail_htlc` sent to
* the link which originally sent the HTLC, using the
* `failure_code` given and setting the data to
* `sha256_of_onion`.
*/
fail = tal_arr(htlc, u8, 0);
towire_u16(&fail, failure_code);
towire_sha256(&fail, &sha256_of_onion);
htlc->fail = fail;
start_commit_timer(peer);
return;
case CHANNEL_ERR_NO_SUCH_ID:
case CHANNEL_ERR_ALREADY_FULFILLED:
case CHANNEL_ERR_HTLC_UNCOMMITTED:
case CHANNEL_ERR_HTLC_NOT_IRREVOCABLE:
case CHANNEL_ERR_BAD_PREIMAGE:
peer_failed(&peer->cs,
&peer->channel_id,
"Bad update_fail_malformed_htlc: failed to remove %"
PRIu64 " error %s", id, channel_remove_err_name(e));
}
abort();
}
static void handle_pong(struct peer *peer, const u8 *pong)
{
const char *err = got_pong(pong, &peer->num_pings_outstanding);
if (err)
peer_failed(&peer->cs,
&peer->channel_id,
"%s", err);
wire_sync_write(MASTER_FD,
take(towire_channel_ping_reply(NULL, tal_len(pong))));
}
static void handle_peer_shutdown(struct peer *peer, const u8 *shutdown)
{
struct channel_id channel_id;
u8 *scriptpubkey;
/* Disable the channel. */
send_channel_update(peer, ROUTING_FLAGS_DISABLED);
if (!fromwire_shutdown(peer, shutdown, &channel_id, &scriptpubkey))
peer_failed(&peer->cs,
&peer->channel_id,
"Bad shutdown %s", tal_hex(peer, shutdown));
/* Tell master: we don't have to wait because on reconnect other end
* will re-send anyway. */
wire_sync_write(MASTER_FD,
take(towire_channel_got_shutdown(NULL, scriptpubkey)));
peer->shutdown_sent[REMOTE] = true;
/* BOLT #2:
*
* A receiving node:
* ...
* - once there are no outstanding updates on the peer, UNLESS
* it has already sent a `shutdown`:
* - MUST reply to a `shutdown` message with a `shutdown`
*/
if (!peer->shutdown_sent[LOCAL]) {
peer->send_shutdown = true;
start_commit_timer(peer);
}
billboard_update(peer);
}
/* Note: msg came from read_peer_msg() which handles pings, gossip,
* wrong channel, errors */
static void peer_in(struct peer *peer, const u8 *msg)
{
enum wire_type type = fromwire_peektype(msg);
/* Must get funding_locked before almost anything. */
if (!peer->funding_locked[REMOTE]) {
if (type != WIRE_FUNDING_LOCKED
&& type != WIRE_PONG
&& type != WIRE_SHUTDOWN) {
peer_failed(&peer->cs,
&peer->channel_id,
"%s (%u) before funding locked",
wire_type_name(type), type);
}
}
switch (type) {
case WIRE_FUNDING_LOCKED:
handle_peer_funding_locked(peer, msg);
return;
case WIRE_ANNOUNCEMENT_SIGNATURES:
handle_peer_announcement_signatures(peer, msg);
return;
case WIRE_UPDATE_ADD_HTLC:
handle_peer_add_htlc(peer, msg);
return;
case WIRE_COMMITMENT_SIGNED:
handle_peer_commit_sig(peer, msg);
return;
case WIRE_UPDATE_FEE:
handle_peer_feechange(peer, msg);
return;
case WIRE_REVOKE_AND_ACK:
handle_peer_revoke_and_ack(peer, msg);
return;
case WIRE_UPDATE_FULFILL_HTLC:
handle_peer_fulfill_htlc(peer, msg);
return;
case WIRE_UPDATE_FAIL_HTLC:
handle_peer_fail_htlc(peer, msg);
return;
case WIRE_UPDATE_FAIL_MALFORMED_HTLC:
handle_peer_fail_malformed_htlc(peer, msg);
return;
case WIRE_PONG:
handle_pong(peer, msg);
return;
case WIRE_SHUTDOWN:
handle_peer_shutdown(peer, msg);
return;
case WIRE_INIT:
case WIRE_OPEN_CHANNEL:
case WIRE_ACCEPT_CHANNEL:
case WIRE_FUNDING_CREATED:
case WIRE_FUNDING_SIGNED:
case WIRE_CHANNEL_REESTABLISH:
case WIRE_CLOSING_SIGNED:
break;
/* These are all swallowed by read_peer_msg */
case WIRE_CHANNEL_ANNOUNCEMENT:
case WIRE_CHANNEL_UPDATE:
case WIRE_NODE_ANNOUNCEMENT:
case WIRE_QUERY_SHORT_CHANNEL_IDS:
case WIRE_QUERY_CHANNEL_RANGE:
case WIRE_REPLY_CHANNEL_RANGE:
case WIRE_GOSSIP_TIMESTAMP_FILTER:
case WIRE_REPLY_SHORT_CHANNEL_IDS_END:
case WIRE_PING:
case WIRE_ERROR:
abort();
}
peer_failed(&peer->cs,
&peer->channel_id,
"Peer sent unknown message %u (%s)",
type, wire_type_name(type));
}
static void peer_conn_broken(struct peer *peer)
{
/* If we have signatures, send an update to say we're disabled. */
send_channel_update(peer, ROUTING_FLAGS_DISABLED);
peer_failed_connection_lost();
}
static void resend_revoke(struct peer *peer)
{
/* Current commit is peer->next_index[LOCAL]-1, revoke prior */
u8 *msg = make_revocation_msg(peer, peer->next_index[LOCAL]-2);
enqueue_peer_msg(peer, take(msg));
}
static void send_fail_or_fulfill(struct peer *peer, const struct htlc *h)
{
u8 *msg;
if (h->malformed) {
struct sha256 sha256_of_onion;
sha256(&sha256_of_onion, h->routing, tal_len(h->routing));
msg = towire_update_fail_malformed_htlc(NULL, &peer->channel_id,
h->id, &sha256_of_onion,
h->malformed);
} else if (h->fail) {
msg = towire_update_fail_htlc(NULL, &peer->channel_id, h->id,
h->fail);
} else if (h->r) {
msg = towire_update_fulfill_htlc(NULL, &peer->channel_id, h->id,
h->r);
} else
peer_failed(&peer->cs,
&peer->channel_id,
"HTLC %"PRIu64" state %s not failed/fulfilled",
h->id, htlc_state_name(h->state));
enqueue_peer_msg(peer, take(msg));
}
static void resend_commitment(struct peer *peer, const struct changed_htlc *last)
{
size_t i;
struct commit_sigs *commit_sigs;
u8 *msg;
/* BOLT #2:
*
* - if `next_local_commitment_number` is equal to the commitment
* number of the last `commitment_signed` message the receiving node
* has sent:
* - MUST reuse the same commitment number for its next
* `commitment_signed`.
*/
/* In our case, we consider ourselves already committed to this, so
* retransmission is simplest. */
for (i = 0; i < tal_count(last); i++) {
const struct htlc *h;
h = channel_get_htlc(peer->channel,
htlc_state_owner(last[i].newstate),
last[i].id);
/* I think this can happen if we actually received revoke_and_ack
* then they asked for a retransmit */
if (!h)
peer_failed(&peer->cs,
&peer->channel_id,
"Can't find HTLC %"PRIu64" to resend",
last[i].id);
if (h->state == SENT_ADD_COMMIT) {
u8 *msg = towire_update_add_htlc(peer, &peer->channel_id,
h->id, h->msatoshi,
&h->rhash,
abs_locktime_to_blocks(
&h->expiry),
h->routing);
enqueue_peer_msg(peer, take(msg));
} else if (h->state == SENT_REMOVE_COMMIT) {
send_fail_or_fulfill(peer, h);
}
}
/* Make sure they have the correct fee. */
if (peer->channel->funder == LOCAL) {
msg = towire_update_fee(NULL, &peer->channel_id,
channel_feerate(peer->channel, REMOTE));
enqueue_peer_msg(peer, take(msg));
}
/* Re-send the commitment_signed itself. */
commit_sigs = calc_commitsigs(peer, peer, peer->next_index[REMOTE]-1);
msg = towire_commitment_signed(NULL, &peer->channel_id,
&commit_sigs->commit_sig,
commit_sigs->htlc_sigs);
enqueue_peer_msg(peer, take(msg));
tal_free(commit_sigs);
/* If we have already received the revocation for the previous, the
* other side shouldn't be asking for a retransmit! */
if (peer->revocations_received != peer->next_index[REMOTE] - 2)
status_unusual("Retransmitted commitment_signed %"PRIu64
" but they already send revocation %"PRIu64"?",
peer->next_index[REMOTE]-1,
peer->revocations_received);
}
/* Our local wrapper around read_peer_msg */
static void channeld_io_error(struct peer *peer)
{
peer_conn_broken(peer);
}
static bool channeld_send_reply(struct crypto_state *cs UNUSED,
int peer_fd UNUSED,
const u8 *msg UNUSED,
struct peer *peer)
{
enqueue_peer_msg(peer, msg);
return true;
}
static u8 *channeld_read_peer_msg(struct peer *peer)
{
return read_peer_msg(peer, &peer->cs,
&peer->channel_id,
channeld_send_reply,
channeld_io_error,
peer);
}
static void peer_reconnect(struct peer *peer)
{
struct channel_id channel_id;
/* Note: BOLT #2 uses these names, which are sender-relative! */
u64 next_local_commitment_number, next_remote_revocation_number;
bool retransmit_revoke_and_ack;
struct htlc_map_iter it;
const struct htlc *htlc;
u8 *msg;
/* BOLT #2:
*
* - upon reconnection:
* - if a channel is in an error state:
* - SHOULD retransmit the error packet and ignore any other packets for
* that channel.
* - otherwise:
* - MUST transmit `channel_reestablish` for each channel.
* - MUST wait to receive the other node's `channel_reestablish`
* message before sending any other messages for that channel.
*
* The sending node:
* - MUST set `next_local_commitment_number` to the commitment number
* of the next `commitment_signed` it expects to receive.
* - MUST set `next_remote_revocation_number` to the commitment number
* of the next `revoke_and_ack` message it expects to receive.
*/
msg = towire_channel_reestablish(NULL, &peer->channel_id,
peer->next_index[LOCAL],
peer->revocations_received);
if (!sync_crypto_write(&peer->cs, PEER_FD, take(msg)))
peer_failed_connection_lost();
peer_billboard(false, "Sent reestablish, waiting for theirs");
/* Read until they say something interesting */
while ((msg = channeld_read_peer_msg(peer)) == NULL)
clean_tmpctx();
if (!fromwire_channel_reestablish(msg, &channel_id,
&next_local_commitment_number,
&next_remote_revocation_number)) {
peer_failed(&peer->cs,
&peer->channel_id,
"bad reestablish msg: %s %s",
wire_type_name(fromwire_peektype(msg)),
tal_hex(msg, msg));
}
status_trace("Got reestablish commit=%"PRIu64" revoke=%"PRIu64,
next_local_commitment_number,
next_remote_revocation_number);
/* BOLT #2:
*
* - if `next_local_commitment_number` is 1 in both the
* `channel_reestablish` it sent and received:
* - MUST retransmit `funding_locked`.
* - otherwise:
* - MUST NOT retransmit `funding_locked`.
*/
if (peer->funding_locked[LOCAL]
&& peer->next_index[LOCAL] == 1
&& next_local_commitment_number == 1) {
u8 *msg;
struct pubkey next_per_commit_point;
/* Contains per commit point #1, for first post-opening commit */
per_commit_point(&peer->shaseed, &next_per_commit_point, 1);
msg = towire_funding_locked(NULL,
&peer->channel_id,
&next_per_commit_point);
enqueue_peer_msg(peer, take(msg));
}
/* Note: next_index is the index of the current commit we're working
* on, but BOLT #2 refers to the *last* commit index, so we -1 where
* required. */
/* BOLT #2:
*
* - if `next_local_commitment_number` is equal to the commitment
* number of the last `commitment_signed` message the receiving node
* has sent:
* - MUST reuse the same commitment number for its next
* `commitment_signed`.
* - otherwise:
* - if `next_local_commitment_number` is not 1 greater than the
* commitment number of the last `commitment_signed` message the
* receiving node has sent:
* - SHOULD fail the channel.
*/
if (next_remote_revocation_number == peer->next_index[LOCAL] - 2) {
/* Don't try to retransmit revocation index -1! */
if (peer->next_index[LOCAL] < 2) {
peer_failed(&peer->cs,
&peer->channel_id,
"bad reestablish revocation_number: %"
PRIu64,
next_remote_revocation_number);
}
retransmit_revoke_and_ack = true;
} else if (next_remote_revocation_number != peer->next_index[LOCAL] - 1) {
peer_failed(&peer->cs,
&peer->channel_id,
"bad reestablish revocation_number: %"PRIu64
" vs %"PRIu64,
next_remote_revocation_number,
peer->next_index[LOCAL]);
} else
retransmit_revoke_and_ack = false;
/* We have to re-send in the same order we sent originally:
* revoke_and_ack (usually) alters our next commitment. */
if (retransmit_revoke_and_ack && !peer->last_was_revoke)
resend_revoke(peer);
/* BOLT #2:
*
* - if `next_local_commitment_number` is equal to the commitment
* number of the last `commitment_signed` message the receiving node
* has sent:
* - MUST reuse the same commitment number for its next
* `commitment_signed`.
*/
if (next_local_commitment_number == peer->next_index[REMOTE] - 1) {
/* We completed opening, we don't re-transmit that one! */
if (next_local_commitment_number == 0)
peer_failed(&peer->cs,
&peer->channel_id,
"bad reestablish commitment_number: %"
PRIu64,
next_local_commitment_number);
resend_commitment(peer, peer->last_sent_commit);
/* BOLT #2:
*
* - otherwise:
* - if `next_local_commitment_number` is not 1 greater than the
* commitment number of the last `commitment_signed` message the
* receiving node has sent:
* - SHOULD fail the channel.
*/
} else if (next_local_commitment_number != peer->next_index[REMOTE])
peer_failed(&peer->cs,
&peer->channel_id,
"bad reestablish commitment_number: %"PRIu64
" vs %"PRIu64,
next_local_commitment_number,
peer->next_index[REMOTE]);
/* This covers the case where we sent revoke after commit. */
if (retransmit_revoke_and_ack && peer->last_was_revoke)
resend_revoke(peer);
/* BOLT #2:
*
* - upon reconnection:
* - if it has sent a previous `shutdown`:
* - MUST retransmit `shutdown`.
*/
/* (If we had sent `closing_signed`, we'd be in closingd). */
maybe_send_shutdown(peer);
/* Corner case: we didn't send shutdown before because update_add_htlc
* pending, but now they're cleared by restart, and we're actually
* complete. In that case, their `shutdown` will trigger us. */
/* Start commit timer: if we sent revoke we might need it. */
start_commit_timer(peer);
/* Now, re-send any that we're supposed to be failing. */
for (htlc = htlc_map_first(peer->channel->htlcs, &it);
htlc;
htlc = htlc_map_next(peer->channel->htlcs, &it)) {
if (htlc->state == SENT_REMOVE_HTLC)
send_fail_or_fulfill(peer, htlc);
}
/* Reenable channel by sending a channel_update without the
* disable flag */
channel_announcement_negotiate(peer);
/* Corner case: we will get upset with them if they send
* commitment_signed with no changes. But it could be that we sent a
* feechange, they acked, and now they want to commit it; we can't
* even tell by seeing if fees are different (short of saving full fee
* state in database) since it could be a tiny feechange, or two
* feechanges which cancelled out. */
if (peer->channel->funder == LOCAL)
peer->channel->changes_pending[LOCAL] = true;
peer_billboard(true, "Reconnected, and reestablished.");
}
/* Funding has locked in, and reached depth. */
static void handle_funding_locked(struct peer *peer, const u8 *msg)
{
unsigned int depth;
if (!fromwire_channel_funding_locked(msg,
&peer->short_channel_ids[LOCAL],
&depth))
master_badmsg(WIRE_CHANNEL_FUNDING_LOCKED, msg);
/* Too late, we're shutting down! */
if (peer->shutdown_sent[LOCAL])
return;
if (!peer->funding_locked[LOCAL]) {
struct pubkey next_per_commit_point;
per_commit_point(&peer->shaseed,
&next_per_commit_point,
peer->next_index[LOCAL]);
status_trace("funding_locked: sending commit index %"PRIu64": %s",
peer->next_index[LOCAL],
type_to_string(tmpctx, struct pubkey, &next_per_commit_point));
msg = towire_funding_locked(NULL,
&peer->channel_id, &next_per_commit_point);
enqueue_peer_msg(peer, take(msg));
peer->funding_locked[LOCAL] = true;
}
peer->announce_depth_reached = (depth >= ANNOUNCE_MIN_DEPTH);
/* Send temporary or final announcements */
channel_announcement_negotiate(peer);
billboard_update(peer);
}
static void handle_offer_htlc(struct peer *peer, const u8 *inmsg)
{
u8 *msg;
u32 cltv_expiry;
u64 amount_msat;
struct sha256 payment_hash;
u8 onion_routing_packet[TOTAL_PACKET_SIZE];
enum channel_add_err e;
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(STATUS_FAIL_MASTER_IO,
"funding not locked for offer_htlc");
if (!fromwire_channel_offer_htlc(inmsg, &amount_msat,
&cltv_expiry, &payment_hash,
onion_routing_packet))
master_badmsg(WIRE_CHANNEL_OFFER_HTLC, inmsg);
e = channel_add_htlc(peer->channel, LOCAL, peer->htlc_id,
amount_msat, cltv_expiry, &payment_hash,
onion_routing_packet, NULL);
status_trace("Adding HTLC %"PRIu64" msat=%"PRIu64" cltv=%u gave %s",
peer->htlc_id, amount_msat, cltv_expiry,
channel_add_err_name(e));
switch (e) {
case CHANNEL_ERR_ADD_OK:
/* Tell the peer. */
msg = towire_update_add_htlc(NULL, &peer->channel_id,
peer->htlc_id, amount_msat,
&payment_hash, cltv_expiry,
onion_routing_packet);
enqueue_peer_msg(peer, take(msg));
start_commit_timer(peer);
/* Tell the master. */
msg = towire_channel_offer_htlc_reply(NULL, peer->htlc_id,
0, NULL);
wire_sync_write(MASTER_FD, take(msg));
peer->htlc_id++;
return;
case CHANNEL_ERR_INVALID_EXPIRY:
failcode = WIRE_INCORRECT_CLTV_EXPIRY;
failmsg = tal_fmt(inmsg, "Invalid cltv_expiry %u", cltv_expiry);
goto failed;
case CHANNEL_ERR_DUPLICATE:
case CHANNEL_ERR_DUPLICATE_ID_DIFFERENT:
status_failed(STATUS_FAIL_MASTER_IO,
"Duplicate HTLC %"PRIu64, peer->htlc_id);
/* FIXME: Fuzz the boundaries a bit to avoid probing? */
case CHANNEL_ERR_MAX_HTLC_VALUE_EXCEEDED:
/* 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:
/* Note: tal_fmt doesn't set tal_len() to exact length, so fix here. */
tal_resize(&failmsg, strlen(failmsg)+1);
msg = towire_channel_offer_htlc_reply(NULL, 0, failcode, (u8*)failmsg);
wire_sync_write(MASTER_FD, take(msg));
}
static void handle_feerates(struct peer *peer, const u8 *inmsg)
{
u32 feerate;
if (!fromwire_channel_feerates(inmsg, &feerate,
&peer->feerate_min,
&peer->feerate_max))
master_badmsg(WIRE_CHANNEL_FEERATES, inmsg);
/* BOLT #2:
*
* The node _responsible_ for paying the Bitcoin fee:
* - SHOULD send `update_fee` to ensure the current fee rate is
* sufficient (by a significant margin) for timely processing of the
* commitment transaction.
*/
if (peer->channel->funder == LOCAL) {
peer->desired_feerate = feerate;
start_commit_timer(peer);
} else {
/* BOLT #2:
*
* The node _not responsible_ for paying the Bitcoin fee:
* - MUST NOT send `update_fee`.
*/
/* FIXME: We could drop to chain if fees are too low, but
* that's fraught too. */
}
}
static void handle_preimage(struct peer *peer, const u8 *inmsg)
{
u8 *msg;
u64 id;
struct preimage preimage;
if (!fromwire_channel_fulfill_htlc(inmsg, &id, &preimage))
master_badmsg(WIRE_CHANNEL_FULFILL_HTLC, inmsg);
switch (channel_fulfill_htlc(peer->channel, REMOTE, id, &preimage)) {
case CHANNEL_ERR_REMOVE_OK:
msg = towire_update_fulfill_htlc(NULL, &peer->channel_id,
id, &preimage);
enqueue_peer_msg(peer, 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(STATUS_FAIL_MASTER_IO,
"HTLC %"PRIu64" preimage failed", id);
}
abort();
}
static u8 *foreign_channel_update(const tal_t *ctx,
struct peer *peer,
const struct short_channel_id *scid)
{
u8 *msg, *update;
msg = towire_gossip_get_update(NULL, scid);
msg = gossipd_wait_sync_reply(tmpctx, peer, take(msg),
WIRE_GOSSIP_GET_UPDATE_REPLY);
if (!fromwire_gossip_get_update_reply(ctx, msg, &update))
status_failed(STATUS_FAIL_GOSSIP_IO,
"Invalid update reply");
return update;
}
static u8 *make_failmsg(const tal_t *ctx,
struct peer *peer,
const struct htlc *htlc,
enum onion_type failcode,
const struct short_channel_id *scid)
{
u8 *msg, *channel_update = NULL;
u32 cltv_expiry = abs_locktime_to_blocks(&htlc->expiry);
switch (failcode) {
case WIRE_INVALID_REALM:
msg = towire_invalid_realm(ctx);
goto done;
case WIRE_TEMPORARY_NODE_FAILURE:
msg = towire_temporary_node_failure(ctx);
goto done;
case WIRE_PERMANENT_NODE_FAILURE:
msg = towire_permanent_node_failure(ctx);
goto done;
case WIRE_REQUIRED_NODE_FEATURE_MISSING:
msg = towire_required_node_feature_missing(ctx);
goto done;
case WIRE_TEMPORARY_CHANNEL_FAILURE:
channel_update = foreign_channel_update(ctx, peer, scid);
msg = towire_temporary_channel_failure(ctx, channel_update);
goto done;
case WIRE_CHANNEL_DISABLED:
msg = towire_channel_disabled(ctx);
goto done;
case WIRE_PERMANENT_CHANNEL_FAILURE:
msg = towire_permanent_channel_failure(ctx);
goto done;
case WIRE_REQUIRED_CHANNEL_FEATURE_MISSING:
msg = towire_required_channel_feature_missing(ctx);
goto done;
case WIRE_UNKNOWN_NEXT_PEER:
msg = towire_unknown_next_peer(ctx);
goto done;
case WIRE_AMOUNT_BELOW_MINIMUM:
channel_update = foreign_channel_update(ctx, peer, scid);
msg = towire_amount_below_minimum(ctx, htlc->msatoshi,
channel_update);
goto done;
case WIRE_FEE_INSUFFICIENT:
channel_update = foreign_channel_update(ctx, peer, scid);
msg = towire_fee_insufficient(ctx, htlc->msatoshi,
channel_update);
goto done;
case WIRE_INCORRECT_CLTV_EXPIRY:
channel_update = foreign_channel_update(ctx, peer, scid);
msg = towire_incorrect_cltv_expiry(ctx, cltv_expiry,
channel_update);
goto done;
case WIRE_EXPIRY_TOO_SOON:
channel_update = foreign_channel_update(ctx, peer, scid);
msg = towire_expiry_too_soon(ctx, channel_update);
goto done;
case WIRE_EXPIRY_TOO_FAR:
msg = towire_expiry_too_far(ctx);
goto done;
case WIRE_UNKNOWN_PAYMENT_HASH:
msg = towire_unknown_payment_hash(ctx);
goto done;
case WIRE_INCORRECT_PAYMENT_AMOUNT:
msg = towire_incorrect_payment_amount(ctx);
goto done;
case WIRE_FINAL_EXPIRY_TOO_SOON:
msg = towire_final_expiry_too_soon(ctx);
goto done;
case WIRE_FINAL_INCORRECT_CLTV_EXPIRY:
msg = towire_final_incorrect_cltv_expiry(ctx, cltv_expiry);
goto done;
case WIRE_FINAL_INCORRECT_HTLC_AMOUNT:
msg = towire_final_incorrect_htlc_amount(ctx, htlc->msatoshi);
goto done;
case WIRE_INVALID_ONION_VERSION:
case WIRE_INVALID_ONION_HMAC:
case WIRE_INVALID_ONION_KEY:
break;
}
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Asked to create failmsg %u (%s)",
failcode, onion_type_name(failcode));
done:
tal_free(channel_update);
return msg;
}
static void handle_fail(struct peer *peer, const u8 *inmsg)
{
u8 *msg;
u64 id;
u8 *errpkt;
u16 failcode;
struct short_channel_id scid;
enum channel_remove_err e;
struct htlc *h;
if (!fromwire_channel_fail_htlc(inmsg, inmsg, &id, &errpkt,
&failcode, &scid))
master_badmsg(WIRE_CHANNEL_FAIL_HTLC, inmsg);
if (failcode && tal_len(errpkt))
status_failed(STATUS_FAIL_MASTER_IO,
"Invalid channel_fail_htlc: %s with errpkt?",
onion_type_name(failcode));
e = channel_fail_htlc(peer->channel, REMOTE, id, &h);
switch (e) {
case CHANNEL_ERR_REMOVE_OK:
if (failcode & BADONION) {
struct sha256 sha256_of_onion;
status_trace("Failing %"PRIu64" with code %u",
id, failcode);
sha256(&sha256_of_onion, h->routing,
tal_len(h->routing));
msg = towire_update_fail_malformed_htlc(peer,
&peer->channel_id,
id, &sha256_of_onion,
failcode);
} else {
u8 *reply;
if (failcode) {
u8 *failmsg = make_failmsg(inmsg, peer, h,
failcode, &scid);
errpkt = create_onionreply(inmsg,
h->shared_secret,
failmsg);
}
reply = wrap_onionreply(inmsg, h->shared_secret,
errpkt);
msg = towire_update_fail_htlc(peer, &peer->channel_id,
id, reply);
}
enqueue_peer_msg(peer, take(msg));
start_commit_timer(peer);
return;
case CHANNEL_ERR_NO_SUCH_ID:
case CHANNEL_ERR_ALREADY_FULFILLED:
case CHANNEL_ERR_HTLC_UNCOMMITTED:
case CHANNEL_ERR_HTLC_NOT_IRREVOCABLE:
case CHANNEL_ERR_BAD_PREIMAGE:
status_failed(STATUS_FAIL_MASTER_IO,
"HTLC %"PRIu64" removal failed: %s", id,
channel_remove_err_name(e));
}
abort();
}
static void handle_ping_cmd(struct peer *peer, const u8 *inmsg)
{
u16 num_pong_bytes, ping_len;
u8 *ping;
if (!fromwire_channel_ping(inmsg, &num_pong_bytes, &ping_len))
master_badmsg(WIRE_CHANNEL_PING, inmsg);
ping = make_ping(NULL, num_pong_bytes, ping_len);
if (tal_len(ping) > 65535)
status_failed(STATUS_FAIL_MASTER_IO, "Oversize channel_ping");
enqueue_peer_msg(peer, take(ping));
status_trace("sending ping expecting %sresponse",
num_pong_bytes >= 65532 ? "no " : "");
/* BOLT #1:
*
* - if `num_pong_bytes` is less than 65532:
* - MUST respond by sending a `pong` message, with `byteslen` equal
* to `num_pong_bytes`.
* - otherwise (`num_pong_bytes` is **not** less than 65532):
* - MUST ignore the `ping`.
*/
if (num_pong_bytes >= 65532)
wire_sync_write(MASTER_FD,
take(towire_channel_ping_reply(NULL, 0)));
else
peer->num_pings_outstanding++;
}
static void handle_shutdown_cmd(struct peer *peer, const u8 *inmsg)
{
if (!fromwire_channel_send_shutdown(inmsg))
master_badmsg(WIRE_CHANNEL_SEND_SHUTDOWN, inmsg);
/* We can't send this until commit (if any) is done, so start timer. */
peer->send_shutdown = true;
start_commit_timer(peer);
}
#if DEVELOPER
static void handle_dev_reenable_commit(struct peer *peer)
{
dev_suppress_commit = false;
start_commit_timer(peer);
status_trace("dev_reenable_commit");
wire_sync_write(MASTER_FD,
take(towire_channel_dev_reenable_commit_reply(NULL)));
}
#endif
static void req_in(struct peer *peer, const u8 *msg)
{
enum channel_wire_type t = fromwire_peektype(msg);
switch (t) {
case WIRE_CHANNEL_FUNDING_LOCKED:
handle_funding_locked(peer, msg);
return;
case WIRE_CHANNEL_OFFER_HTLC:
handle_offer_htlc(peer, msg);
return;
case WIRE_CHANNEL_FEERATES:
handle_feerates(peer, msg);
return;
case WIRE_CHANNEL_FULFILL_HTLC:
handle_preimage(peer, msg);
return;
case WIRE_CHANNEL_FAIL_HTLC:
handle_fail(peer, msg);
return;
case WIRE_CHANNEL_PING:
handle_ping_cmd(peer, msg);
return;
case WIRE_CHANNEL_SEND_SHUTDOWN:
handle_shutdown_cmd(peer, msg);
return;
case WIRE_CHANNEL_DEV_REENABLE_COMMIT:
#if DEVELOPER
handle_dev_reenable_commit(peer);
return;
#endif /* DEVELOPER */
case WIRE_CHANNEL_INIT:
case WIRE_CHANNEL_OFFER_HTLC_REPLY:
case WIRE_CHANNEL_PING_REPLY:
case WIRE_CHANNEL_SENDING_COMMITSIG:
case WIRE_CHANNEL_GOT_COMMITSIG:
case WIRE_CHANNEL_GOT_REVOKE:
case WIRE_CHANNEL_SENDING_COMMITSIG_REPLY:
case WIRE_CHANNEL_GOT_COMMITSIG_REPLY:
case WIRE_CHANNEL_GOT_REVOKE_REPLY:
case WIRE_CHANNEL_GOT_FUNDING_LOCKED:
case WIRE_CHANNEL_GOT_SHUTDOWN:
case WIRE_CHANNEL_SHUTDOWN_COMPLETE:
case WIRE_CHANNEL_DEV_REENABLE_COMMIT_REPLY:
break;
}
master_badmsg(-1, msg);
}
static void init_shared_secrets(struct channel *channel,
const struct added_htlc *htlcs,
const enum htlc_state *hstates)
{
for (size_t i = 0; i < tal_count(htlcs); i++) {
struct htlc *htlc;
/* We only derive this for HTLCs *they* added. */
if (htlc_state_owner(hstates[i]) != REMOTE)
continue;
htlc = channel_get_htlc(channel, REMOTE, htlcs[i].id);
htlc->shared_secret = tal(htlc, struct secret);
get_shared_secret(htlc, htlc->shared_secret);
}
}
/* We do this synchronously. */
static void init_channel(struct peer *peer)
{
struct privkey seed;
struct basepoints points[NUM_SIDES];
u64 funding_satoshi;
u16 funding_txout;
u64 local_msatoshi;
struct pubkey funding_pubkey[NUM_SIDES];
struct bitcoin_txid funding_txid;
enum side funder;
enum htlc_state *hstates;
struct fulfilled_htlc *fulfilled;
enum side *fulfilled_sides;
struct failed_htlc **failed;
enum side *failed_sides;
struct added_htlc *htlcs;
bool reconnected;
u8 *funding_signed;
u8 *msg;
u32 feerate_per_kw[NUM_SIDES];
assert(!(fcntl(MASTER_FD, F_GETFL) & O_NONBLOCK));
status_setup_sync(MASTER_FD);
msg = wire_sync_read(peer, MASTER_FD);
if (!fromwire_channel_init(peer, msg,
&peer->chain_hash,
&funding_txid, &funding_txout,
&funding_satoshi,
&peer->conf[LOCAL], &peer->conf[REMOTE],
feerate_per_kw,
&peer->feerate_min, &peer->feerate_max,
&peer->their_commit_sig,
&peer->cs,
&funding_pubkey[REMOTE],
&points[REMOTE].revocation,
&points[REMOTE].payment,
&points[REMOTE].htlc,
&points[REMOTE].delayed_payment,
&peer->remote_per_commit,
&peer->old_remote_per_commit,
&funder,
&peer->fee_base,
&peer->fee_per_satoshi,
&local_msatoshi,
&seed,
&peer->node_ids[LOCAL],
&peer->node_ids[REMOTE],
&peer->commit_msec,
&peer->cltv_delta,
&peer->last_was_revoke,
&peer->last_sent_commit,
&peer->next_index[LOCAL],
&peer->next_index[REMOTE],
&peer->revocations_received,
&peer->htlc_id,
&htlcs,
&hstates,
&fulfilled,
&fulfilled_sides,
&failed,
&failed_sides,
&peer->funding_locked[LOCAL],
&peer->funding_locked[REMOTE],
&peer->short_channel_ids[LOCAL],
&reconnected,
&peer->send_shutdown,
&peer->shutdown_sent[REMOTE],
&peer->final_scriptpubkey,
&peer->channel_flags,
&funding_signed,
&peer->announce_depth_reached))
master_badmsg(WIRE_CHANNEL_INIT, msg);
status_trace("init %s: remote_per_commit = %s, old_remote_per_commit = %s"
" next_idx_local = %"PRIu64
" next_idx_remote = %"PRIu64
" revocations_received = %"PRIu64
" feerates %u/%u (range %u-%u)",
side_to_str(funder),
type_to_string(tmpctx, struct pubkey,
&peer->remote_per_commit),
type_to_string(tmpctx, struct pubkey,
&peer->old_remote_per_commit),
peer->next_index[LOCAL], peer->next_index[REMOTE],
peer->revocations_received,
feerate_per_kw[LOCAL], feerate_per_kw[REMOTE],
peer->feerate_min, peer->feerate_max);
/* First commit is used for opening: if we've sent 0, we're on
* index 1. */
assert(peer->next_index[LOCAL] > 0);
assert(peer->next_index[REMOTE] > 0);
/* channel_id is set from funding txout */
derive_channel_id(&peer->channel_id, &funding_txid, funding_txout);
/* We derive everything from the one secret seed. */
derive_basepoints(&seed, &funding_pubkey[LOCAL], &points[LOCAL],
&peer->our_secrets, &peer->shaseed);
peer->channel = new_full_channel(peer, &funding_txid, funding_txout,
funding_satoshi,
local_msatoshi,
feerate_per_kw,
&peer->conf[LOCAL], &peer->conf[REMOTE],
&points[LOCAL], &points[REMOTE],
&funding_pubkey[LOCAL],
&funding_pubkey[REMOTE],
funder);
if (!channel_force_htlcs(peer->channel, htlcs, hstates,
fulfilled, fulfilled_sides,
cast_const2(const struct failed_htlc **,
failed),
failed_sides))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Could not restore HTLCs");
/* We derive shared secrets for each remote HTLC, so we can
* create error packet if necessary. */
init_shared_secrets(peer->channel, htlcs, hstates);
peer->channel_direction = get_channel_direction(
&peer->node_ids[LOCAL], &peer->node_ids[REMOTE]);
/* Default desired feerate is the feerate we set for them last. */
if (peer->channel->funder == LOCAL)
peer->desired_feerate = feerate_per_kw[REMOTE];
/* OK, now we can process peer messages. */
if (reconnected)
peer_reconnect(peer);
/* If we have a funding_signed message, send that immediately */
if (funding_signed)
enqueue_peer_msg(peer, take(funding_signed));
channel_announcement_negotiate(peer);
billboard_update(peer);
tal_free(msg);
}
static void send_shutdown_complete(struct peer *peer)
{
/* Push out any incomplete messages to peer. */
flush_peer_out(peer);
/* Now we can tell master shutdown is complete. */
wire_sync_write(MASTER_FD,
take(towire_channel_shutdown_complete(NULL, &peer->cs)));
fdpass_send(MASTER_FD, PEER_FD);
fdpass_send(MASTER_FD, GOSSIP_FD);
close(MASTER_FD);
}
int main(int argc, char *argv[])
{
setup_locale();
int i, nfds;
fd_set fds_in, fds_out;
struct peer *peer;
subdaemon_setup(argc, argv);
peer = tal(NULL, struct peer);
peer->num_pings_outstanding = 0;
timers_init(&peer->timers, time_mono());
peer->commit_timer = NULL;
peer->have_sigs[LOCAL] = peer->have_sigs[REMOTE] = false;
peer->announce_depth_reached = false;
peer->channel_local_active = false;
msg_queue_init(&peer->from_master, peer);
msg_queue_init(&peer->from_gossipd, peer);
msg_queue_init(&peer->peer_out, peer);
peer->peer_outmsg = NULL;
peer->peer_outoff = 0;
peer->next_commit_sigs = NULL;
peer->shutdown_sent[LOCAL] = false;
peer->last_update_timestamp = 0;
/* We send these to HSM to get real signatures; don't have valgrind
* complain. */
for (i = 0; i < NUM_SIDES; i++) {
memset(&peer->announcement_node_sigs[i], 0,
sizeof(peer->announcement_node_sigs[i]));
memset(&peer->announcement_bitcoin_sigs[i], 0,
sizeof(peer->announcement_bitcoin_sigs[i]));
}
/* Read init_channel message sync. */
init_channel(peer);
FD_ZERO(&fds_in);
FD_SET(MASTER_FD, &fds_in);
FD_SET(PEER_FD, &fds_in);
FD_SET(GOSSIP_FD, &fds_in);
FD_ZERO(&fds_out);
FD_SET(PEER_FD, &fds_out);
nfds = GOSSIP_FD+1;
while (!shutdown_complete(peer)) {
struct timemono first;
fd_set rfds = fds_in, wfds, *wptr;
struct timeval timeout, *tptr;
struct timer *expired;
const u8 *msg;
struct timemono now = time_mono();
/* Free any temporary allocations */
clean_tmpctx();
/* For simplicity, we process one event at a time. */
msg = msg_dequeue(&peer->from_master);
if (msg) {
status_trace("Now dealing with deferred %s",
channel_wire_type_name(
fromwire_peektype(msg)));
req_in(peer, msg);
tal_free(msg);
continue;
}
expired = timers_expire(&peer->timers, now);
if (expired) {
timer_expired(peer, expired);
continue;
}
msg = msg_dequeue(&peer->from_gossipd);
if (msg) {
status_trace("Now dealing with deferred gossip %u",
fromwire_peektype(msg));
handle_gossip_msg(take(msg), &peer->cs,
channeld_send_reply,
channeld_io_error,
peer);
continue;
}
if (timer_earliest(&peer->timers, &first)) {
timeout = timespec_to_timeval(
timemono_between(first, now).ts);
tptr = &timeout;
} else
tptr = NULL;
if (peer_write_pending(peer)) {
wfds = fds_out;
wptr = &wfds;
} else
wptr = NULL;
if (select(nfds, &rfds, wptr, NULL, tptr) < 0) {
/* Signals OK, eg. SIGUSR1 */
if (errno == EINTR)
continue;
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"select failed: %s", strerror(errno));
}
/* Try writing out encrypted packet if any (don't block!) */
if (wptr && FD_ISSET(PEER_FD, wptr)) {
if (!io_fd_block(PEER_FD, false))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"NONBLOCK failed: %s",
strerror(errno));
do_peer_write(peer);
if (!io_fd_block(PEER_FD, true))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"NONBLOCK unset failed: %s",
strerror(errno));
continue;
}
if (FD_ISSET(MASTER_FD, &rfds)) {
msg = wire_sync_read(peer, MASTER_FD);
if (!msg)
status_failed(STATUS_FAIL_MASTER_IO,
"Can't read command: %s",
strerror(errno));
req_in(peer, msg);
} else if (FD_ISSET(GOSSIP_FD, &rfds)) {
msg = wire_sync_read(peer, GOSSIP_FD);
/* Gossipd hangs up on us to kill us when a new
* connection comes in. */
if (!msg)
peer_conn_broken(peer);
handle_gossip_msg(msg, &peer->cs,
channeld_send_reply,
channeld_io_error,
peer);
} else if (FD_ISSET(PEER_FD, &rfds)) {
/* This could take forever, but who cares? */
msg = channeld_read_peer_msg(peer);
if (msg)
peer_in(peer, msg);
} else
msg = NULL;
tal_free(msg);
}
/* We only exit when shutdown is complete. */
assert(shutdown_complete(peer));
send_shutdown_complete(peer);
daemon_shutdown();
return 0;
}