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lightning/lightningd/peer_htlcs.c

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#include <bitcoin/preimage.h>
#include <bitcoin/tx.h>
#include <ccan/build_assert/build_assert.h>
#include <ccan/cast/cast.h>
#include <ccan/crypto/ripemd160/ripemd160.h>
#include <ccan/mem/mem.h>
#include <ccan/tal/str/str.h>
#include <channeld/channeld_wiregen.h>
#include <common/blinding.h>
#include <common/coin_mvt.h>
#include <common/ecdh.h>
#include <common/json_command.h>
#include <common/json_helpers.h>
#include <common/jsonrpc_errors.h>
#include <common/onion.h>
#include <common/onionreply.h>
#include <common/overflows.h>
#include <common/param.h>
#include <common/sphinx.h>
#include <common/timeout.h>
#include <common/utils.h>
#include <gossipd/gossipd_wiregen.h>
#include <lightningd/chaintopology.h>
#include <lightningd/coin_mvts.h>
#include <lightningd/htlc_end.h>
#include <lightningd/htlc_set.h>
#include <lightningd/json.h>
#include <lightningd/jsonrpc.h>
#include <lightningd/lightningd.h>
#include <lightningd/log.h>
#include <lightningd/options.h>
#include <lightningd/pay.h>
#include <lightningd/peer_control.h>
#include <lightningd/peer_htlcs.h>
#include <lightningd/plugin_hook.h>
#include <lightningd/subd.h>
#include <onchaind/onchaind_wiregen.h>
#include <wallet/wallet.h>
#include <wire/onion_wire.h>
#include <wire/wire_sync.h>
#ifndef SUPERVERBOSE
#define SUPERVERBOSE(...)
#endif
static bool state_update_ok(struct channel *channel,
enum htlc_state oldstate, enum htlc_state newstate,
u64 htlc_id, const char *dir)
{
enum htlc_state expected = oldstate + 1;
/* We never get told about RCVD_REMOVE_HTLC, so skip over that
* (we initialize in SENT_ADD_HTLC / RCVD_ADD_COMMIT, so those
* work). */
if (expected == RCVD_REMOVE_HTLC)
expected = RCVD_REMOVE_COMMIT;
if (newstate != expected) {
channel_internal_error(channel,
"HTLC %s %"PRIu64" invalid update %s->%s",
dir, htlc_id,
htlc_state_name(oldstate),
htlc_state_name(newstate));
return false;
}
log_debug(channel->log, "HTLC %s %"PRIu64" %s->%s",
dir, htlc_id,
htlc_state_name(oldstate), htlc_state_name(newstate));
return true;
}
static bool htlc_in_update_state(struct channel *channel,
struct htlc_in *hin,
enum htlc_state newstate)
{
if (!state_update_ok(channel, hin->hstate, newstate, hin->key.id, "in"))
return false;
wallet_htlc_update(channel->peer->ld->wallet,
hin->dbid, newstate, hin->preimage,
hin->badonion, hin->failonion, NULL,
hin->we_filled);
hin->hstate = newstate;
return true;
}
static bool htlc_out_update_state(struct channel *channel,
struct htlc_out *hout,
enum htlc_state newstate)
{
if (!state_update_ok(channel, hout->hstate, newstate, hout->key.id,
"out"))
return false;
bool we_filled = false;
wallet_htlc_update(channel->peer->ld->wallet, hout->dbid, newstate,
hout->preimage, 0, hout->failonion,
hout->failmsg, &we_filled);
hout->hstate = newstate;
return true;
}
static struct failed_htlc *mk_failed_htlc_badonion(const tal_t *ctx,
const struct htlc_in *hin,
enum onion_wire badonion)
{
struct failed_htlc *f = tal(ctx, struct failed_htlc);
f->id = hin->key.id;
f->onion = NULL;
f->badonion = badonion;
f->sha256_of_onion = tal(f, struct sha256);
sha256(f->sha256_of_onion, hin->onion_routing_packet,
sizeof(hin->onion_routing_packet));
return f;
}
static struct failed_htlc *mk_failed_htlc(const tal_t *ctx,
const struct htlc_in *hin,
const struct onionreply *failonion)
{
struct failed_htlc *f = tal(ctx, struct failed_htlc);
f->id = hin->key.id;
f->sha256_of_onion = NULL;
f->badonion = 0;
/* Wrap onion error */
f->onion = wrap_onionreply(f, hin->shared_secret, failonion);
return f;
}
static void tell_channeld_htlc_failed(const struct htlc_in *hin,
const struct failed_htlc *failed_htlc)
{
/* Tell peer, if we can. */
if (!hin->key.channel->owner)
return;
/* onchaind doesn't care, it can't do anything but wait */
if (!channel_active(hin->key.channel))
return;
subd_send_msg(hin->key.channel->owner,
take(towire_channeld_fail_htlc(NULL, failed_htlc)));
}
struct failmsg_update_cbdata {
struct htlc_in *hin;
const u8 *failmsg_needs_update;
};
static void failmsg_update_reply(struct subd *gossipd,
const u8 *msg,
const int *unused,
struct failmsg_update_cbdata *cbdata)
{
u8 *failmsg;
u8 *stripped_update;
struct failed_htlc *failed_htlc;
/* This can happen because channel never got properly announced.*/
if (!fromwire_gossipd_get_stripped_cupdate_reply(msg, msg,
&stripped_update)
|| !tal_count(stripped_update)) {
failmsg = towire_temporary_node_failure(NULL);
} else {
/* End of failmsg is two zero bytes (empty update). */
assert(tal_count(cbdata->failmsg_needs_update) >= 2);
failmsg = tal_dup_arr(msg, u8,
cbdata->failmsg_needs_update,
tal_count(cbdata->failmsg_needs_update)-2,
0);
towire_u16(&failmsg, tal_count(stripped_update));
towire_u8_array(&failmsg,
stripped_update, tal_count(stripped_update));
}
/* Now we replace dummy failonion with this real one */
tal_free(cbdata->hin->failonion);
cbdata->hin->failonion
= create_onionreply(cbdata->hin,
cbdata->hin->shared_secret,
failmsg);
bool we_filled = false;
wallet_htlc_update(gossipd->ld->wallet,
cbdata->hin->dbid, cbdata->hin->hstate,
cbdata->hin->preimage,
cbdata->hin->badonion,
cbdata->hin->failonion, NULL, &we_filled);
failed_htlc = mk_failed_htlc(tmpctx,
cbdata->hin, cbdata->hin->failonion);
tell_channeld_htlc_failed(cbdata->hin, failed_htlc);
}
static void fail_in_htlc(struct htlc_in *hin,
const struct onionreply *failonion TAKES)
{
struct failed_htlc *failed_htlc;
assert(!hin->preimage);
hin->failonion = dup_onionreply(hin, failonion);
/* We update state now to signal it's in progress, for persistence. */
htlc_in_update_state(hin->key.channel, hin, SENT_REMOVE_HTLC);
htlc_in_check(hin, __func__);
#if EXPERIMENTAL_FEATURES
/* In a blinded path, all failures become invalid_onion_blinding */
if (hin->blinding) {
failed_htlc = mk_failed_htlc_badonion(tmpctx, hin,
WIRE_INVALID_ONION_BLINDING);
} else
#endif
failed_htlc = mk_failed_htlc(tmpctx, hin, hin->failonion);
tell_channeld_htlc_failed(hin, failed_htlc);
}
/* Immediately fail HTLC with a BADONION code */
static void local_fail_in_htlc_badonion(struct htlc_in *hin,
enum onion_wire badonion)
{
struct failed_htlc *failed_htlc;
assert(!hin->preimage);
assert(badonion & BADONION);
hin->badonion = badonion;
/* We update state now to signal it's in progress, for persistence. */
htlc_in_update_state(hin->key.channel, hin, SENT_REMOVE_HTLC);
htlc_in_check(hin, __func__);
failed_htlc = mk_failed_htlc_badonion(tmpctx, hin, badonion);
tell_channeld_htlc_failed(hin, failed_htlc);
}
/* This is used for cases where we can immediately fail the HTLC. */
void local_fail_in_htlc(struct htlc_in *hin, const u8 *failmsg TAKES)
{
struct onionreply *failonion = create_onionreply(NULL,
hin->shared_secret,
failmsg);
if (taken(failmsg))
tal_free(failmsg);
fail_in_htlc(hin, take(failonion));
}
/* This is used for cases where we can immediately fail the HTLC, but
* need to append a channel_update. */
void local_fail_in_htlc_needs_update(struct htlc_in *hin,
const u8 *failmsg_needs_update TAKES,
const struct short_channel_id *failmsg_scid)
{
struct failmsg_update_cbdata *cbdata;
/* To avoid the state where we have no failonion, we use a temporary
* one, and update once we get the reply from gossipd. */
assert(!hin->preimage);
hin->failonion = create_onionreply(hin,
hin->shared_secret,
towire_temporary_node_failure(tmpctx));
/* We update state now to signal it's in progress, for persistence. */
htlc_in_update_state(hin->key.channel, hin, SENT_REMOVE_HTLC);
htlc_in_check(hin, __func__);
cbdata = tal(hin, struct failmsg_update_cbdata);
cbdata->hin = hin;
cbdata->failmsg_needs_update
= tal_dup_talarr(cbdata, u8, failmsg_needs_update);
subd_req(cbdata, hin->key.channel->peer->ld->gossip,
take(towire_gossipd_get_stripped_cupdate(NULL, failmsg_scid)),
-1, 0, failmsg_update_reply, cbdata);
}
/* Helper to create (common) WIRE_INCORRECT_OR_UNKNOWN_PAYMENT_DETAILS */
const u8 *failmsg_incorrect_or_unknown_(const tal_t *ctx,
struct lightningd *ld,
const struct htlc_in *hin,
const char *file, int line)
{
log_debug(ld->log, "WIRE_INCORRECT_OR_UNKNOWN_PAYMENT_DETAILS: %s:%u",
file, line);
return towire_incorrect_or_unknown_payment_details(
ctx, hin->msat,
get_block_height(ld->topology));
}
/* localfail are for handing to the local payer if it's local. */
static void fail_out_htlc(struct htlc_out *hout,
const char *localfail,
const u8 *failmsg_needs_update TAKES)
{
htlc_out_check(hout, __func__);
assert(hout->failmsg || hout->failonion);
if (hout->am_origin) {
payment_failed(hout->key.channel->peer->ld, hout, localfail,
failmsg_needs_update);
if (taken(failmsg_needs_update))
tal_free(failmsg_needs_update);
} else if (hout->in) {
if (failmsg_needs_update) {
local_fail_in_htlc_needs_update(hout->in,
failmsg_needs_update,
hout->key.channel->scid);
} else {
const struct onionreply *failonion;
/* If we have an onion, simply copy it. */
if (hout->failonion)
failonion = hout->failonion;
/* Otherwise, we need to onionize this local error. */
else
failonion = create_onionreply(hout,
hout->in->shared_secret,
hout->failmsg);
fail_in_htlc(hout->in, failonion);
}
} else {
if (taken(failmsg_needs_update))
tal_free(failmsg_needs_update);
}
}
/* BOLT #4:
*
* * `amt_to_forward`: The amount, in millisatoshis, to forward to the next
* receiving peer specified within the routing information.
*
* For non-final nodes, this value amount MUST include the origin node's computed _fee_ for the
* receiving peer. When processing an incoming Sphinx packet and the HTLC
* message that it is encapsulated within, if the following inequality
* doesn't hold, then the HTLC should be rejected as it would indicate that
* a prior hop has deviated from the specified parameters:
*
* incoming_htlc_amt - fee >= amt_to_forward
*
* Where `fee` is calculated according to the receiving peer's
* advertised fee schema (as described in [BOLT
* #7](07-routing-gossip.md#htlc-fees)).
*/
static bool check_fwd_amount(struct htlc_in *hin,
struct amount_msat amt_to_forward,
struct amount_msat amt_in_htlc,
struct amount_msat fee)
{
struct amount_msat fwd;
if (amount_msat_sub(&fwd, amt_in_htlc, fee)
&& amount_msat_greater_eq(fwd, amt_to_forward))
return true;
log_debug(hin->key.channel->log, "HTLC %"PRIu64" incorrect amount:"
" %s in, %s out, fee reqd %s",
hin->key.id,
type_to_string(tmpctx, struct amount_msat, &amt_in_htlc),
type_to_string(tmpctx, struct amount_msat, &amt_to_forward),
type_to_string(tmpctx, struct amount_msat, &fee));
return false;
}
/* BOLT #4:
*
* * `outgoing_cltv_value`: The CLTV value that the _outgoing_ HTLC carrying
* the packet should have.
*
* cltv_expiry - cltv_expiry_delta >= outgoing_cltv_value
*
* Inclusion of this field allows a hop to both authenticate the
* information specified by the origin node, and the parameters of the
* HTLC forwarded, and ensure the origin node is using the current
* `cltv_expiry_delta` value. If there is no next hop,
* `cltv_expiry_delta` is 0. If the values don't correspond, then the
* HTLC should be failed and rejected, as this indicates that either a
* forwarding node has tampered with the intended HTLC values or that the
* origin node has an obsolete `cltv_expiry_delta` value. The hop MUST be
* consistent in responding to an unexpected `outgoing_cltv_value`,
* whether it is the final node or not, to avoid leaking its position in
* the route.
*/
static bool check_cltv(struct htlc_in *hin,
u32 cltv_expiry, u32 outgoing_cltv_value, u32 delta)
{
if (delta < cltv_expiry && cltv_expiry - delta >= outgoing_cltv_value)
return true;
log_debug(hin->key.channel->log, "HTLC %"PRIu64" incorrect CLTV:"
" %u in, %u out, delta reqd %u",
hin->key.id, cltv_expiry, outgoing_cltv_value, delta);
return false;
}
void fulfill_htlc(struct htlc_in *hin, const struct preimage *preimage)
{
u8 *msg;
struct channel *channel = hin->key.channel;
struct wallet *wallet = channel->peer->ld->wallet;
if (hin->hstate != RCVD_ADD_ACK_REVOCATION) {
log_debug(channel->log,
"HTLC fulfilled, but not ready any more (%s).",
htlc_state_name(hin->hstate));
return;
}
hin->preimage = tal_dup(hin, struct preimage, preimage);
/* We update state now to signal it's in progress, for persistence. */
htlc_in_update_state(channel, hin, SENT_REMOVE_HTLC);
htlc_in_check(hin, __func__);
/* Update channel stats */
wallet_channel_stats_incr_in_fulfilled(wallet,
channel->dbid,
hin->msat);
/* No owner? We'll either send to channeld in peer_htlcs, or
* onchaind in onchaind_tell_fulfill. */
if (!channel->owner) {
log_debug(channel->log, "HTLC fulfilled, but no owner.");
return;
}
if (channel_on_chain(channel)) {
msg = towire_onchaind_known_preimage(hin, preimage, false);
} else {
struct fulfilled_htlc fulfilled_htlc;
fulfilled_htlc.id = hin->key.id;
fulfilled_htlc.payment_preimage = *preimage;
msg = towire_channeld_fulfill_htlc(hin, &fulfilled_htlc);
}
subd_send_msg(channel->owner, take(msg));
}
static void handle_localpay(struct htlc_in *hin,
struct amount_msat amt_to_forward,
u32 outgoing_cltv_value,
struct amount_msat total_msat,
const struct secret *payment_secret)
{
const u8 *failmsg;
struct lightningd *ld = hin->key.channel->peer->ld;
/* BOLT #4:
*
* For the final node, this value MUST be exactly equal to the
* incoming htlc amount, otherwise the HTLC should be rejected.
*/
if (!amount_msat_eq(amt_to_forward, hin->msat)) {
log_debug(hin->key.channel->log,
"HTLC %"PRIu64" final incorrect amount:"
" %s in, %s expected",
hin->key.id,
type_to_string(tmpctx, struct amount_msat, &hin->msat),
type_to_string(tmpctx, struct amount_msat,
&amt_to_forward));
/* BOLT #4:
*
* 1. type: 19 (`final_incorrect_htlc_amount`)
* 2. data:
* * [`u64`:`incoming_htlc_amt`]
*
* The amount in the HTLC doesn't match the value in the onion.
*/
failmsg = towire_final_incorrect_htlc_amount(NULL, hin->msat);
goto fail;
}
/* BOLT #4:
*
* 1. type: 18 (`final_incorrect_cltv_expiry`)
* 2. data:
* * [`u32`:`cltv_expiry`]
*
* The CLTV expiry in the HTLC doesn't match the value in the onion.
*/
if (!check_cltv(hin, hin->cltv_expiry, outgoing_cltv_value, 0)) {
failmsg = towire_final_incorrect_cltv_expiry(NULL,
hin->cltv_expiry);
goto fail;
}
/* BOLT #4:
*
* - if the `cltv_expiry` value is unreasonably near the present:
* - MUST fail the HTLC.
* - MUST return an `incorrect_or_unknown_payment_details` error.
*/
if (get_block_height(ld->topology) + ld->config.cltv_final
> hin->cltv_expiry) {
log_debug(hin->key.channel->log,
"Expiry cltv too soon %u < %u + %u",
hin->cltv_expiry,
get_block_height(ld->topology),
ld->config.cltv_final);
failmsg = failmsg_incorrect_or_unknown(NULL, ld, hin);
goto fail;
}
htlc_set_add(ld, hin, total_msat, payment_secret);
return;
fail:
local_fail_in_htlc(hin, take(failmsg));
}
/*
* A catchall in case outgoing peer disconnects before getting fwd.
*
* We could queue this and wait for it to come back, but this is simple.
*/
static void destroy_hout_subd_died(struct htlc_out *hout)
{
log_debug(hout->key.channel->log,
"Failing HTLC %"PRIu64" due to peer death",
hout->key.id);
/* This isn't really used, except as sanity check */
hout->failmsg = towire_temporary_node_failure(hout);
/* Assign a temporary state (we're about to free it!) so checks
* are happy that it has a failure message */
assert(hout->hstate == SENT_ADD_HTLC);
hout->hstate = RCVD_REMOVE_HTLC;
fail_out_htlc(hout, "Outgoing subdaemon died",
take(towire_temporary_channel_failure(NULL, NULL)));
}
/* This is where channeld gives us the HTLC id, and also reports if it
* failed immediately. */
static void rcvd_htlc_reply(struct subd *subd, const u8 *msg, const int *fds UNUSED,
struct htlc_out *hout)
{
u8 *failmsg;
char *failurestr;
struct lightningd *ld = subd->ld;
if (!fromwire_channeld_offer_htlc_reply(msg, msg,
&hout->key.id,
&failmsg,
&failurestr)) {
channel_internal_error(subd->channel,
"Bad channel_offer_htlc_reply");
tal_free(hout);
return;
}
if (tal_count(failmsg)) {
hout->failmsg = tal_steal(hout, failmsg);
if (hout->am_origin) {
char *localfail = tal_fmt(msg, "%s: %s",
onion_wire_name(fromwire_peektype(failmsg)),
failurestr);
payment_failed(ld, hout, localfail, NULL);
} else if (hout->in) {
struct onionreply *failonion;
failonion = create_onionreply(hout,
hout->in->shared_secret,
hout->failmsg);
fail_in_htlc(hout->in, failonion);
/* here we haven't called connect_htlc_out(),
* so set htlc field with NULL */
wallet_forwarded_payment_add(ld->wallet,
hout->in, NULL, NULL,
FORWARD_LOCAL_FAILED,
fromwire_peektype(hout->failmsg));
}
/* Prevent hout from being failed twice. */
tal_del_destructor(hout, destroy_hout_subd_died);
tal_free(hout);
return;
}
if (find_htlc_out(&subd->ld->htlcs_out, hout->key.channel, hout->key.id)
|| hout->key.id == HTLC_INVALID_ID) {
channel_internal_error(subd->channel,
"Bad offer_htlc_reply HTLC id %"PRIu64
" is a duplicate",
hout->key.id);
tal_free(hout);
return;
}
/* Add it to lookup table now we know id. */
connect_htlc_out(&subd->ld->htlcs_out, hout);
/* When channeld includes it in commitment, we'll make it persistent. */
}
static void htlc_offer_timeout(struct channel *channel)
{
/* Unset this in case we reconnect and start again. */
channel->htlc_timeout = NULL;
/* If owner died, we should already be taken care of. */
if (!channel->owner || channel->state != CHANNELD_NORMAL)
return;
log_unusual(channel->owner->log,
"Adding HTLC too slow: killing connection");
tal_free(channel->owner);
channel_set_billboard(channel, false,
"Adding HTLC timed out: killed connection");
}
/* Returns failmsg, or NULL on success. */
const u8 *send_htlc_out(const tal_t *ctx,
struct channel *out,
struct amount_msat amount, u32 cltv,
const struct sha256 *payment_hash,
const struct pubkey *blinding,
u64 partid,
const u8 *onion_routing_packet,
struct htlc_in *in,
struct htlc_out **houtp,
bool *needs_update_appended)
{
u8 *msg;
*houtp = NULL;
*needs_update_appended = false;
if (!channel_can_add_htlc(out)) {
log_info(out->log, "Attempt to send HTLC but not ready (%s)",
channel_state_name(out));
return towire_unknown_next_peer(ctx);
}
if (!out->owner) {
log_info(out->log, "Attempt to send HTLC but unowned (%s)",
channel_state_name(out));
*needs_update_appended = true;
return towire_temporary_channel_failure(ctx, NULL);
}
if (!topology_synced(out->peer->ld->topology)) {
log_info(out->log, "Attempt to send HTLC but still syncing"
" with bitcoin network");
return towire_temporary_node_failure(ctx);
}
/* Make peer's daemon own it, catch if it dies. */
*houtp = new_htlc_out(out->owner, out, amount, cltv,
payment_hash, onion_routing_packet,
blinding, in == NULL,
partid, in);
tal_add_destructor(*houtp, destroy_hout_subd_died);
/* Give channel 30 seconds to commit (first) htlc. */
if (!out->htlc_timeout && !IFDEV(out->peer->ld->dev_no_htlc_timeout, 0))
out->htlc_timeout = new_reltimer(out->peer->ld->timers,
out, time_from_sec(30),
htlc_offer_timeout,
out);
msg = towire_channeld_offer_htlc(out, amount, cltv, payment_hash,
onion_routing_packet, blinding);
subd_req(out->peer->ld, out->owner, take(msg), -1, 0, rcvd_htlc_reply,
*houtp);
return NULL;
}
static void forward_htlc(struct htlc_in *hin,
u32 cltv_expiry,
struct amount_msat amt_to_forward,
u32 outgoing_cltv_value,
const struct short_channel_id *scid,
const u8 next_onion[TOTAL_PACKET_SIZE(ROUTING_INFO_SIZE)],
const struct pubkey *next_blinding)
{
const u8 *failmsg;
struct amount_msat fee;
struct lightningd *ld = hin->key.channel->peer->ld;
struct channel *next = active_channel_by_scid(ld, scid);
struct htlc_out *hout = NULL;
bool needs_update_appended;
/* Unknown peer, or peer not ready. */
if (!next || !next->scid) {
local_fail_in_htlc(hin, take(towire_unknown_next_peer(NULL)));
wallet_forwarded_payment_add(hin->key.channel->peer->ld->wallet,
hin, next ? next->scid : NULL, NULL,
FORWARD_LOCAL_FAILED,
WIRE_UNKNOWN_NEXT_PEER);
return;
}
/* BOLT #7:
*
* The origin node:
* - SHOULD accept HTLCs that pay a fee equal to or greater than:
* - fee_base_msat + ( amount_to_forward * fee_proportional_millionths / 1000000 )
*/
if (!amount_msat_fee(&fee, amt_to_forward,
next->feerate_base,
next->feerate_ppm)) {
log_broken(ld->log, "Fee overflow forwarding %s!",
type_to_string(tmpctx, struct amount_msat,
&amt_to_forward));
needs_update_appended = true;
failmsg = towire_fee_insufficient(tmpctx, hin->msat, NULL);
goto fail;
}
if (!check_fwd_amount(hin, amt_to_forward, hin->msat, fee)) {
needs_update_appended = true;
failmsg = towire_fee_insufficient(tmpctx, hin->msat, NULL);
goto fail;
}
if (!check_cltv(hin, cltv_expiry, outgoing_cltv_value,
ld->config.cltv_expiry_delta)) {
needs_update_appended = true;
failmsg = towire_incorrect_cltv_expiry(tmpctx, cltv_expiry,
NULL);
goto fail;
}
if (amount_msat_greater(amt_to_forward,
chainparams->max_payment)) {
/* ENOWUMBO! */
needs_update_appended = false;
failmsg = towire_required_channel_feature_missing(tmpctx);
goto fail;
}
/* BOLT #2:
*
* An offering node:
* - MUST estimate a timeout deadline for each HTLC it offers.
* - MUST NOT offer an HTLC with a timeout deadline before its
* `cltv_expiry`.
*/
/* In our case, G = 1, so we need to expire it one after it's expiration.
* But never offer an expired HTLC; that's dumb. */
if (get_block_height(ld->topology) >= outgoing_cltv_value) {
log_debug(hin->key.channel->log,
"Expiry cltv %u too close to current %u",
outgoing_cltv_value,
get_block_height(ld->topology));
needs_update_appended = true;
failmsg = towire_expiry_too_soon(tmpctx, NULL);
goto fail;
}
/* BOLT #4:
*
* - if the `cltv_expiry` is unreasonably far in the future:
* - return an `expiry_too_far` error.
*/
if (get_block_height(ld->topology)
+ ld->config.locktime_max < outgoing_cltv_value) {
log_debug(hin->key.channel->log,
"Expiry cltv %u too far from current %u + max %u",
outgoing_cltv_value,
get_block_height(ld->topology),
ld->config.locktime_max);
needs_update_appended = false;
failmsg = towire_expiry_too_far(tmpctx);
goto fail;
}
failmsg = send_htlc_out(tmpctx, next, amt_to_forward,
outgoing_cltv_value, &hin->payment_hash,
next_blinding, 0, next_onion, hin,
&hout, &needs_update_appended);
if (!failmsg)
return;
fail:
if (needs_update_appended)
local_fail_in_htlc_needs_update(hin, failmsg, next->scid);
else
local_fail_in_htlc(hin, failmsg);
wallet_forwarded_payment_add(ld->wallet,
hin, next->scid, hout,
FORWARD_LOCAL_FAILED,
fromwire_peektype(failmsg));
}
/**
* Data passed to the plugin, and as the context for the hook callback
*/
struct htlc_accepted_hook_payload {
struct route_step *route_step;
/* NULL if it couldn't be parsed! */
struct onion_payload *payload;
struct htlc_in *hin;
struct channel *channel;
struct lightningd *ld;
struct pubkey *next_blinding;
u8 *next_onion;
u64 failtlvtype;
size_t failtlvpos;
};
/* We only handle the simplest cases here */
static u8 *convert_failcode(const tal_t *ctx,
struct lightningd *ld,
unsigned int failure_code)
{
switch (failure_code) {
case WIRE_INVALID_REALM:
return towire_invalid_realm(ctx);
case WIRE_TEMPORARY_NODE_FAILURE:
return towire_temporary_node_failure(ctx);
case WIRE_PERMANENT_NODE_FAILURE:
return towire_permanent_node_failure(ctx);
case WIRE_REQUIRED_NODE_FEATURE_MISSING:
return towire_required_node_feature_missing(ctx);
case WIRE_CHANNEL_DISABLED:
return towire_channel_disabled(ctx);
case WIRE_PERMANENT_CHANNEL_FAILURE:
return towire_permanent_channel_failure(ctx);
case WIRE_REQUIRED_CHANNEL_FEATURE_MISSING:
return towire_required_channel_feature_missing(ctx);
case WIRE_UNKNOWN_NEXT_PEER:
return towire_unknown_next_peer(ctx);
default:
log_broken(ld->log,
"htlc_accepted_hook plugin returned failure_code %u,"
" turning to WIRE_TEMPORARY_NODE_FAILURE",
failure_code);
return towire_temporary_node_failure(ctx);
}
}
static void
htlc_accepted_hook_try_resolve(struct htlc_accepted_hook_payload *request,
struct preimage *payment_preimage)
{
struct sha256 payment_hash;
struct htlc_in *hin = request->hin;
u8 *unknown_details;
/* Verify that the provided secret hashes to what we need. */
sha256(&payment_hash, payment_preimage, sizeof(struct preimage));
if (!sha256_eq(&payment_hash, &hin->payment_hash)) {
log_broken(
request->channel->log,
"Plugin returned a preimage (sha256(%s) = %s) that doesn't "
"match the HTLC hash (%s) it tries to resolve.",
type_to_string(tmpctx, struct preimage, payment_preimage),
type_to_string(tmpctx, struct sha256, &payment_hash),
type_to_string(tmpctx, struct sha256, &hin->payment_hash));
unknown_details = tal_arr(NULL, u8, 0);
towire_u16(&unknown_details, 0x400f);
local_fail_in_htlc(hin, take(unknown_details));
} else {
hin->we_filled = tal(hin, bool);
*hin->we_filled = true;
fulfill_htlc(hin, payment_preimage);
}
}
static u8 *prepend_length(const tal_t *ctx, const u8 *payload TAKES)
{
u8 buf[BIGSIZE_MAX_LEN], *ret;
size_t len;
len = bigsize_put(buf, tal_bytelen(payload));
ret = tal_arr(ctx, u8, len + tal_bytelen(payload));
memcpy(ret, buf, len);
memcpy(ret + len, payload, tal_bytelen(payload));
if (taken(payload))
tal_free(payload);
return ret;
}
/**
* Callback when a plugin answers to the htlc_accepted hook
*/
static bool htlc_accepted_hook_deserialize(struct htlc_accepted_hook_payload *request,
const char *buffer,
const jsmntok_t *toks)
{
struct route_step *rs = request->route_step;
struct htlc_in *hin = request->hin;
struct lightningd *ld = request->ld;
struct preimage payment_preimage;
const jsmntok_t *resulttok, *paykeytok, *payloadtok;
u8 *payload, *failonion;
if (!toks || !buffer)
return true;
resulttok = json_get_member(buffer, toks, "result");
/* If the result is "continue" we can just return NULL since
* this is the default behavior for this hook anyway */
if (!resulttok) {
fatal("Plugin return value does not contain 'result' key %s",
json_strdup(tmpctx, buffer, toks));
}
payloadtok = json_get_member(buffer, toks, "payload");
if (payloadtok) {
payload = json_tok_bin_from_hex(rs, buffer, payloadtok);
if (!payload)
fatal("Bad payload for htlc_accepted"
" hook: %.*s",
payloadtok->end - payloadtok->start,
buffer + payloadtok->start);
tal_free(request->payload);
tal_free(rs->raw_payload);
rs->raw_payload = prepend_length(rs, take(payload));
request->payload = onion_decode(request, rs,
hin->blinding, &hin->blinding_ss,
&request->failtlvtype,
&request->failtlvpos);
} else
payload = NULL;
if (json_tok_streq(buffer, resulttok, "continue")) {
return true;
}
if (json_tok_streq(buffer, resulttok, "fail")) {
u8 *failmsg;
const jsmntok_t *failoniontok, *failmsgtok, *failcodetok;
failoniontok = json_get_member(buffer, toks, "failure_onion");
failmsgtok = json_get_member(buffer, toks, "failure_message");
if (failoniontok) {
failonion = json_tok_bin_from_hex(tmpctx, buffer,
failoniontok);
if (!failonion)
fatal("Bad failure_onion for htlc_accepted"
" hook: %.*s",
failoniontok->end - failoniontok->start,
buffer + failoniontok->start);
if (failmsgtok)
log_broken(ld->log, "Both 'failure_onion' and"
"'failure_message' provided."
" Ignoring 'failure_message'.");
fail_in_htlc(hin, take(new_onionreply(NULL,
failonion)));
return false;
}
if (failmsgtok) {
failmsg = json_tok_bin_from_hex(NULL, buffer,
failmsgtok);
if (!failmsg)
fatal("Bad failure_message for htlc_accepted"
" hook: %.*s",
failmsgtok->end - failmsgtok->start,
buffer + failmsgtok->start);
local_fail_in_htlc(hin, take(failmsg));
return false;
} else if (deprecated_apis
&& (failcodetok = json_get_member(buffer, toks,
"failure_code"))) {
unsigned int failcode;
if (!json_to_number(buffer, failcodetok, &failcode))
fatal("Bad failure_code for htlc_accepted"
" hook: %.*s",
failcodetok->end
- failcodetok->start,
buffer + failcodetok->start);
failmsg = convert_failcode(NULL, ld, failcode);
local_fail_in_htlc(hin, take(failmsg));
return false;
} else {
failmsg = towire_temporary_node_failure(NULL);
local_fail_in_htlc(hin, take(failmsg));
return false;
}
} else if (json_tok_streq(buffer, resulttok, "resolve")) {
paykeytok = json_get_member(buffer, toks, "payment_key");
if (!paykeytok)
fatal(
"Plugin did not specify a 'payment_key' in return "
"value to the htlc_accepted hook: %s",
json_strdup(tmpctx, buffer, resulttok));
if (!json_to_preimage(buffer, paykeytok, &payment_preimage))
fatal("Plugin specified an invalid 'payment_key': %s",
json_tok_full(buffer, resulttok));
htlc_accepted_hook_try_resolve(request, &payment_preimage);
return false;
} else {
fatal("Plugin responded with an unknown result to the "
"htlc_accepted hook: %s",
json_strdup(tmpctx, buffer, resulttok));
}
}
static void htlc_accepted_hook_serialize(struct htlc_accepted_hook_payload *p,
struct json_stream *s)
{
const struct route_step *rs = p->route_step;
const struct htlc_in *hin = p->hin;
s32 expiry = hin->cltv_expiry, blockheight = p->ld->topology->tip->height;
json_object_start(s, "onion");
json_add_hex_talarr(s, "payload", rs->raw_payload);
if (p->payload) {
switch (p->payload->type) {
case ONION_V0_PAYLOAD:
json_add_string(s, "type", "legacy");
break;
case ONION_TLV_PAYLOAD:
json_add_string(s, "type", "tlv");
break;
}
if (p->payload->forward_channel)
json_add_short_channel_id(s, "short_channel_id",
p->payload->forward_channel);
json_add_amount_msat_only(s, "forward_amount",
p->payload->amt_to_forward);
json_add_u32(s, "outgoing_cltv_value", p->payload->outgoing_cltv);
/* These are specified together in TLV, so only print total_msat
* if payment_secret set (ie. modern, and final hop) */
if (p->payload->payment_secret) {
json_add_amount_msat_only(s, "total_msat",
*p->payload->total_msat);
json_add_secret(s, "payment_secret",
p->payload->payment_secret);
}
}
json_add_hex_talarr(s, "next_onion", p->next_onion);
json_add_secret(s, "shared_secret", hin->shared_secret);
json_object_end(s);
json_object_start(s, "htlc");
json_add_amount_msat_only(s, "amount", hin->msat);
json_add_u32(s, "cltv_expiry", expiry);
json_add_s32(s, "cltv_expiry_relative", expiry - blockheight);
json_add_sha256(s, "payment_hash", &hin->payment_hash);
json_object_end(s);
}
/**
* Callback when a plugin answers to the htlc_accepted hook
*/
static void
htlc_accepted_hook_final(struct htlc_accepted_hook_payload *request STEALS)
{
struct route_step *rs = request->route_step;
struct htlc_in *hin = request->hin;
struct channel *channel = request->channel;
/* *Now* we barf if it failed to decode */
if (!request->payload) {
log_debug(channel->log,
"Failing HTLC because of an invalid payload");
local_fail_in_htlc(hin,
take(towire_invalid_onion_payload(
NULL, request->failtlvtype,
request->failtlvpos)));
} else if (rs->nextcase == ONION_FORWARD) {
forward_htlc(hin, hin->cltv_expiry,
request->payload->amt_to_forward,
request->payload->outgoing_cltv,
request->payload->forward_channel,
serialize_onionpacket(tmpctx, rs->next),
request->next_blinding);
} else
handle_localpay(hin,
request->payload->amt_to_forward,
request->payload->outgoing_cltv,
*request->payload->total_msat,
request->payload->payment_secret);
tal_free(request);
}
REGISTER_PLUGIN_HOOK(htlc_accepted,
htlc_accepted_hook_deserialize,
htlc_accepted_hook_final,
htlc_accepted_hook_serialize,
struct htlc_accepted_hook_payload *);
/* Apply tweak to ephemeral key if blinding is non-NULL, then do ECDH */
static bool ecdh_maybe_blinding(const struct pubkey *ephemeral_key,
const struct pubkey *blinding,
const struct secret *blinding_ss,
struct secret *ss)
{
struct pubkey point = *ephemeral_key;
#if EXPERIMENTAL_FEATURES
if (blinding) {
struct secret hmac;
/* b(i) = HMAC256("blinded_node_id", ss(i)) * k(i) */
subkey_from_hmac("blinded_node_id", blinding_ss, &hmac);
/* We instead tweak the *ephemeral* key from the onion and use
* our normal privkey: since hsmd knows only how to ECDH with
* our real key */
if (secp256k1_ec_pubkey_tweak_mul(secp256k1_ctx,
&point.pubkey,
hmac.data) != 1) {
return false;
}
}
#endif /* EXPERIMENTAL_FEATURES */
ecdh(&point, ss);
return true;
}
/**
* Everyone is committed to this htlc of theirs
*
* @param ctx: context for failmsg, if any.
* @param channel: The channel this HTLC was accepted from.
* @param id: the ID of the HTLC we accepted
* @param replay: Are we loading from the database and therefore should not
* perform the transition to RCVD_ADD_ACK_REVOCATION?
* @param[out] badonion: Set non-zero if the onion was bad.
* @param[out] failmsg: If there was some other error.
*
* If this returns false, exactly one of @badonion or @failmsg is set.
*/
static bool peer_accepted_htlc(const tal_t *ctx,
struct channel *channel, u64 id,
bool replay,
enum onion_wire *badonion,
u8 **failmsg)
{
struct htlc_in *hin;
struct route_step *rs;
struct onionpacket *op;
struct lightningd *ld = channel->peer->ld;
struct htlc_accepted_hook_payload *hook_payload;
*failmsg = NULL;
*badonion = 0;
hin = find_htlc_in(&ld->htlcs_in, channel, id);
if (!hin) {
channel_internal_error(channel,
"peer_got_revoke unknown htlc %"PRIu64, id);
*failmsg = towire_temporary_node_failure(ctx);
goto fail;
}
if (!replay && !htlc_in_update_state(channel, hin, RCVD_ADD_ACK_REVOCATION)) {
*failmsg = towire_temporary_node_failure(ctx);
goto fail;
}
htlc_in_check(hin, __func__);
#if DEVELOPER
if (channel->peer->ignore_htlcs) {
log_debug(channel->log, "their htlc %"PRIu64" dev_ignore_htlcs",
id);
return true;
}
#endif
/* BOLT #2:
*
* - SHOULD fail to route any HTLC added after it has sent `shutdown`.
*/
if (channel->state == CHANNELD_SHUTTING_DOWN) {
*failmsg = towire_permanent_channel_failure(ctx);
log_debug(channel->log,
"Rejecting their htlc %"PRIu64
" since we're shutting down",
id);
goto fail;
}
/* BOLT #2:
*
* A fulfilling node:
* - for each HTLC it is attempting to fulfill:
* - MUST estimate a fulfillment deadline.
* - MUST fail (and not forward) an HTLC whose fulfillment deadline is
* already past.
*/
/* Our deadline is half the cltv_delta we insist on, so this check is
* a subset of the cltv check done in handle_localpay and
* forward_htlc. */
op = parse_onionpacket(tmpctx, hin->onion_routing_packet,
sizeof(hin->onion_routing_packet),
badonion);
if (!op) {
log_debug(channel->log,
"Rejecting their htlc %"PRIu64
" since onion is unparsable %s",
id, onion_wire_name(*badonion));
/* Now we can fail it. */
goto fail;
}
rs = process_onionpacket(tmpctx, op, hin->shared_secret,
hin->payment_hash.u.u8,
sizeof(hin->payment_hash), true);
if (!rs) {
*badonion = WIRE_INVALID_ONION_HMAC;
log_debug(channel->log,
"Rejecting their htlc %"PRIu64
" since onion is unprocessable %s ss=%s",
id, onion_wire_name(*badonion),
type_to_string(tmpctx, struct secret, hin->shared_secret));
goto fail;
}
hook_payload = tal(NULL, struct htlc_accepted_hook_payload);
hook_payload->route_step = tal_steal(hook_payload, rs);
hook_payload->payload = onion_decode(hook_payload, rs,
hin->blinding, &hin->blinding_ss,
&hook_payload->failtlvtype,
&hook_payload->failtlvpos);
hook_payload->ld = ld;
hook_payload->hin = hin;
hook_payload->channel = channel;
hook_payload->next_onion = serialize_onionpacket(hook_payload, rs->next);
#if EXPERIMENTAL_FEATURES
/* We could have blinding from hin or from inside onion. */
if (hook_payload->payload && hook_payload->payload->blinding) {
struct sha256 sha;
blinding_hash_e_and_ss(hook_payload->payload->blinding,
&hook_payload->payload->blinding_ss,
&sha);
hook_payload->next_blinding = tal(hook_payload, struct pubkey);
blinding_next_pubkey(hook_payload->payload->blinding, &sha,
hook_payload->next_blinding);
} else
#endif
hook_payload->next_blinding = NULL;
plugin_hook_call_htlc_accepted(ld, hook_payload);
/* Falling through here is ok, after all the HTLC locked */
return true;
fail:
#if EXPERIMENTAL_FEATURES
/* In a blinded path, *all* failures are "invalid_onion_blinding" */
if (hin->blinding) {
*failmsg = tal_free(*failmsg);
*badonion = WIRE_INVALID_ONION_BLINDING;
}
#endif
return false;
}
static void fulfill_our_htlc_out(struct channel *channel, struct htlc_out *hout,
const struct preimage *preimage)
{
struct lightningd *ld = channel->peer->ld;
bool we_filled = false;
assert(!hout->preimage);
hout->preimage = tal_dup(hout, struct preimage, preimage);
htlc_out_check(hout, __func__);
wallet_htlc_update(ld->wallet, hout->dbid, hout->hstate,
hout->preimage, 0, hout->failonion,
hout->failmsg, &we_filled);
/* Update channel stats */
wallet_channel_stats_incr_out_fulfilled(ld->wallet,
channel->dbid,
hout->msat);
if (hout->am_origin)
payment_succeeded(ld, hout, preimage);
else if (hout->in) {
fulfill_htlc(hout->in, preimage);
wallet_forwarded_payment_add(ld->wallet, hout->in,
hout->key.channel->scid, hout,
FORWARD_SETTLED, 0);
}
}
static bool peer_fulfilled_our_htlc(struct channel *channel,
const struct fulfilled_htlc *fulfilled)
{
struct lightningd *ld = channel->peer->ld;
struct htlc_out *hout;
hout = find_htlc_out(&ld->htlcs_out, channel, fulfilled->id);
if (!hout) {
channel_internal_error(channel,
"fulfilled_our_htlc unknown htlc %"PRIu64,
fulfilled->id);
return false;
}
if (!htlc_out_update_state(channel, hout, RCVD_REMOVE_COMMIT))
return false;
fulfill_our_htlc_out(channel, hout, &fulfilled->payment_preimage);
return true;
}
void onchain_fulfilled_htlc(struct channel *channel,
const struct preimage *preimage)
{
struct htlc_out_map_iter outi;
struct htlc_out *hout;
struct sha256 payment_hash;
struct lightningd *ld = channel->peer->ld;
sha256(&payment_hash, preimage, sizeof(*preimage));
/* FIXME: use db to look this up! */
for (hout = htlc_out_map_first(&ld->htlcs_out, &outi);
hout;
hout = htlc_out_map_next(&ld->htlcs_out, &outi)) {
if (hout->key.channel != channel)
continue;
/* It's possible that we failed some and succeeded one,
* if we got multiple errors. */
if (hout->failmsg || hout->failonion)
continue;
if (!sha256_eq(&hout->payment_hash, &payment_hash))
continue;
/* We may have already fulfilled before going onchain, or
* we can fulfill onchain multiple times. */
if (!hout->preimage) {
/* Force state to something which allows a preimage */
hout->hstate = RCVD_REMOVE_HTLC;
fulfill_our_htlc_out(channel, hout, preimage);
}
/* We keep going: this is something of a leak, but onchain
* we have no real way of distinguishing HTLCs anyway */
}
}
static bool peer_failed_our_htlc(struct channel *channel,
const struct failed_htlc *failed)
{
struct htlc_out *hout;
struct lightningd *ld = channel->peer->ld;
hout = find_htlc_out(&ld->htlcs_out, channel, failed->id);
if (!hout) {
channel_internal_error(channel,
"failed_our_htlc unknown htlc %"PRIu64,
failed->id);
return false;
}
if (!htlc_out_update_state(channel, hout, RCVD_REMOVE_COMMIT))
return false;
if (failed->sha256_of_onion) {
struct sha256 our_sha256_of_onion;
u8 *failmsg;
/* 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.
*/
sha256(&our_sha256_of_onion, hout->onion_routing_packet,
sizeof(hout->onion_routing_packet));
if (!sha256_eq(failed->sha256_of_onion, &our_sha256_of_onion))
log_unusual(channel->log,
"update_fail_malformed_htlc for bad onion"
" for htlc with id %"PRIu64".",
hout->key.id);
/* 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`.
*/
/* All badonion codes are the same form, so we make them
* manually, which covers any unknown cases too. Grep fodder:
* towire_invalid_onion_version, towire_invalid_onion_hmac,
* towire_invalid_onion_key. */
failmsg = tal_arr(hout, u8, 0);
towire_u16(&failmsg, failed->badonion);
towire_sha256(&failmsg, failed->sha256_of_onion);
hout->failmsg = failmsg;
} else {
hout->failonion = dup_onionreply(hout, failed->onion);
}
log_debug(channel->log, "Our HTLC %"PRIu64" failed (%u)", failed->id,
fromwire_peektype(hout->failmsg));
htlc_out_check(hout, __func__);
if (hout->in)
wallet_forwarded_payment_add(ld->wallet, hout->in,
channel->scid,
hout, FORWARD_FAILED,
hout->failmsg
? fromwire_peektype(hout->failmsg)
: 0);
return true;
}
void onchain_failed_our_htlc(const struct channel *channel,
const struct htlc_stub *htlc,
const char *why)
{
struct lightningd *ld = channel->peer->ld;
struct htlc_out *hout;
hout = find_htlc_out(&ld->htlcs_out, channel, htlc->id);
if (!hout)
return;
/* Don't fail twice (or if already succeeded)! */
if (hout->failonion || hout->failmsg || hout->preimage)
return;
hout->failmsg = towire_permanent_channel_failure(hout);
/* Force state to something which expects a failure, and save to db */
hout->hstate = RCVD_REMOVE_HTLC;
htlc_out_check(hout, __func__);
bool we_filled = false;
wallet_htlc_update(ld->wallet, hout->dbid, hout->hstate,
hout->preimage, 0, hout->failonion,
hout->failmsg, &we_filled);
if (hout->am_origin) {
assert(why != NULL);
char *localfail = tal_fmt(channel, "%s: %s",
onion_wire_name(WIRE_PERMANENT_CHANNEL_FAILURE),
why);
payment_failed(ld, hout, localfail, NULL);
tal_free(localfail);
} else if (hout->in) {
local_fail_in_htlc(hout->in,
take(towire_permanent_channel_failure(NULL)));
wallet_forwarded_payment_add(hout->key.channel->peer->ld->wallet,
hout->in, channel->scid, hout,
FORWARD_LOCAL_FAILED,
hout->failmsg
? fromwire_peektype(hout->failmsg)
: 0);
}
}
static void remove_htlc_in(struct channel *channel, struct htlc_in *hin)
{
htlc_in_check(hin, __func__);
assert(hin->failonion || hin->preimage || hin->badonion);
log_debug(channel->log, "Removing in HTLC %"PRIu64" state %s %s",
hin->key.id, htlc_state_name(hin->hstate),
hin->preimage ? "FULFILLED"
: hin->badonion ? onion_wire_name(hin->badonion)
: "REMOTEFAIL");
/* If we fulfilled their HTLC, credit us. */
if (hin->preimage) {
struct amount_msat oldamt = channel->our_msat;
const struct channel_coin_mvt *mvt;
if (!amount_msat_add(&channel->our_msat, channel->our_msat,
hin->msat)) {
channel_internal_error(channel,
"Overflow our_msat %s + HTLC %s",
type_to_string(tmpctx,
struct amount_msat,
&channel->our_msat),
type_to_string(tmpctx,
struct amount_msat,
&hin->msat));
}
log_debug(channel->log, "Balance %s -> %s",
type_to_string(tmpctx, struct amount_msat, &oldamt),
type_to_string(tmpctx, struct amount_msat,
&channel->our_msat));
if (amount_msat_greater(channel->our_msat,
channel->msat_to_us_max))
channel->msat_to_us_max = channel->our_msat;
/* Coins have definitively moved, log a movement */
if (hin->we_filled)
mvt = new_channel_mvt_invoice_hin(hin, hin, channel);
else
mvt = new_channel_mvt_routed_hin(hin, hin, channel);
notify_channel_mvt(channel->peer->ld, mvt);
}
tal_free(hin);
}
static void remove_htlc_out(struct channel *channel, struct htlc_out *hout)
{
htlc_out_check(hout, __func__);
assert(hout->failonion || hout->preimage || hout->failmsg);
log_debug(channel->log, "Removing out HTLC %"PRIu64" state %s %s",
hout->key.id, htlc_state_name(hout->hstate),
hout->preimage ? "FULFILLED"
: hout->failmsg ? onion_wire_name(fromwire_peektype(hout->failmsg))
: "REMOTEFAIL");
/* If it's failed, now we can forward since it's completely locked-in */
if (!hout->preimage) {
fail_out_htlc(hout, NULL, NULL);
} else {
const struct channel_coin_mvt *mvt;
struct amount_msat oldamt = channel->our_msat;
/* We paid for this HTLC, so deduct balance. */
if (!amount_msat_sub(&channel->our_msat, channel->our_msat,
hout->msat)) {
channel_internal_error(channel,
"Underflow our_msat %s - HTLC %s",
type_to_string(tmpctx,
struct amount_msat,
&channel->our_msat),
type_to_string(tmpctx,
struct amount_msat,
&hout->msat));
}
log_debug(channel->log, "Balance %s -> %s",
type_to_string(tmpctx, struct amount_msat, &oldamt),
type_to_string(tmpctx, struct amount_msat,
&channel->our_msat));
if (amount_msat_less(channel->our_msat, channel->msat_to_us_min))
channel->msat_to_us_min = channel->our_msat;
/* Coins have definitively moved, log a movement */
if (hout->am_origin)
mvt = new_channel_mvt_invoice_hout(hout, hout, channel);
else
mvt = new_channel_mvt_routed_hout(hout, hout, channel);
notify_channel_mvt(channel->peer->ld, mvt);
}
tal_free(hout);
}
static bool update_in_htlc(struct channel *channel,
u64 id, enum htlc_state newstate)
{
struct htlc_in *hin;
struct lightningd *ld = channel->peer->ld;
hin = find_htlc_in(&ld->htlcs_in, channel, id);
if (!hin) {
channel_internal_error(channel, "Can't find in HTLC %"PRIu64, id);
return false;
}
if (!htlc_in_update_state(channel, hin, newstate))
return false;
htlc_in_check(hin, __func__);
if (newstate == SENT_REMOVE_ACK_REVOCATION)
remove_htlc_in(channel, hin);
return true;
}
static bool update_out_htlc(struct channel *channel,
u64 id, enum htlc_state newstate)
{
struct lightningd *ld = channel->peer->ld;
struct htlc_out *hout;
struct wallet_payment *payment;
hout = find_htlc_out(&ld->htlcs_out, channel, id);
if (!hout) {
channel_internal_error(channel, "Can't find out HTLC %"PRIu64, id);
return false;
}
if (!hout->dbid) {
wallet_htlc_save_out(ld->wallet, channel, hout);
/* Update channel stats */
wallet_channel_stats_incr_out_offered(ld->wallet,
channel->dbid,
hout->msat);
if (hout->in) {
wallet_forwarded_payment_add(ld->wallet, hout->in,
channel->scid, hout,
FORWARD_OFFERED, 0);
}
/* For our own HTLCs, we commit payment to db lazily */
if (hout->am_origin) {
payment = wallet_payment_by_hash(tmpctx, ld->wallet,
&hout->payment_hash,
hout->partid);
assert(payment);
payment_store(ld, take(payment));
}
}
if (!htlc_out_update_state(channel, hout, newstate))
return false;
/* First transition into commitment; now it outlives peer. */
if (newstate == SENT_ADD_COMMIT) {
tal_del_destructor(hout, destroy_hout_subd_died);
tal_steal(ld, hout);
} else if (newstate == RCVD_REMOVE_ACK_REVOCATION) {
remove_htlc_out(channel, hout);
}
return true;
}
static bool changed_htlc(struct channel *channel,
const struct changed_htlc *changed)
{
if (htlc_state_owner(changed->newstate) == LOCAL)
return update_out_htlc(channel, changed->id, changed->newstate);
else
return update_in_htlc(channel, changed->id, changed->newstate);
}
/* FIXME: This should be a complete check, not just a sanity check.
* Perhaps that means we need a cookie from the HSM? */
static bool valid_commitment_tx(struct channel *channel,
const struct bitcoin_tx *tx)
{
/* We've had past issues where all outputs are trimmed. */
if (tx->wtx->num_outputs == 0) {
channel_internal_error(channel,
"channel_got_commitsig: zero output tx! %s",
type_to_string(tmpctx, struct bitcoin_tx, tx));
return false;
}
return true;
}
static bool peer_save_commitsig_received(struct channel *channel, u64 commitnum,
struct bitcoin_tx *tx,
const struct bitcoin_signature *commit_sig)
{
if (commitnum != channel->next_index[LOCAL]) {
channel_internal_error(channel,
"channel_got_commitsig: expected commitnum %"PRIu64
" got %"PRIu64,
channel->next_index[LOCAL], commitnum);
return false;
}
/* Basic sanity check */
if (!valid_commitment_tx(channel, tx))
return false;
channel->next_index[LOCAL]++;
/* Update channel->last_sig and channel->last_tx before saving to db */
channel_set_last_tx(channel, tx, commit_sig, TX_CHANNEL_UNILATERAL);
return true;
}
static bool peer_save_commitsig_sent(struct channel *channel, u64 commitnum)
{
struct lightningd *ld = channel->peer->ld;
if (commitnum != channel->next_index[REMOTE]) {
channel_internal_error(channel,
"channel_sent_commitsig: expected commitnum %"PRIu64
" got %"PRIu64,
channel->next_index[REMOTE], commitnum);
return false;
}
channel->next_index[REMOTE]++;
/* FIXME: Save to database, with sig and HTLCs. */
wallet_channel_save(ld->wallet, channel);
return true;
}
static void adjust_channel_feerate_bounds(struct channel *channel, u32 feerate)
{
if (feerate > channel->max_possible_feerate)
channel->max_possible_feerate = feerate;
if (feerate < channel->min_possible_feerate)
channel->min_possible_feerate = feerate;
}
void peer_sending_commitsig(struct channel *channel, const u8 *msg)
{
u64 commitnum;
struct fee_states *fee_states;
struct changed_htlc *changed_htlcs;
size_t i, maxid = 0, num_local_added = 0;
struct bitcoin_signature commit_sig;
struct bitcoin_signature *htlc_sigs;
struct lightningd *ld = channel->peer->ld;
struct penalty_base *pbase;
channel->htlc_timeout = tal_free(channel->htlc_timeout);
if (!fromwire_channeld_sending_commitsig(msg, msg,
&commitnum,
&pbase,
&fee_states,
&changed_htlcs,
&commit_sig, &htlc_sigs)
|| !fee_states_valid(fee_states, channel->opener)) {
channel_internal_error(channel, "bad channel_sending_commitsig %s",
tal_hex(channel, msg));
return;
}
for (i = 0; i < tal_count(changed_htlcs); i++) {
if (!changed_htlc(channel, changed_htlcs + i)) {
channel_internal_error(channel,
"channel_sending_commitsig: update failed");
return;
}
/* While we're here, sanity check added ones are in
* ascending order. */
if (changed_htlcs[i].newstate == SENT_ADD_COMMIT) {
num_local_added++;
if (changed_htlcs[i].id > maxid)
maxid = changed_htlcs[i].id;
}
}
if (num_local_added != 0) {
if (maxid != channel->next_htlc_id + num_local_added - 1) {
channel_internal_error(channel,
"channel_sending_commitsig:"
" Added %"PRIu64", maxid now %"PRIu64
" from %"PRIu64,
num_local_added, maxid, channel->next_htlc_id);
return;
}
channel->next_htlc_id += num_local_added;
}
/* FIXME: We could detect if this changed, and adjust bounds and write
* it to db iff it has. */
tal_free(channel->fee_states);
channel->fee_states = tal_steal(channel, fee_states);
adjust_channel_feerate_bounds(channel,
get_feerate(fee_states,
channel->opener,
REMOTE));
if (!peer_save_commitsig_sent(channel, commitnum))
return;
/* Last was commit. */
channel->last_was_revoke = false;
tal_free(channel->last_sent_commit);
channel->last_sent_commit = tal_steal(channel, changed_htlcs);
wallet_channel_save(ld->wallet, channel);
if (pbase)
wallet_penalty_base_add(ld->wallet, channel->dbid, pbase);
/* Tell it we've got it, and to go ahead with commitment_signed. */
subd_send_msg(channel->owner,
take(towire_channeld_sending_commitsig_reply(msg)));
}
static bool channel_added_their_htlc(struct channel *channel,
const struct added_htlc *added)
{
struct lightningd *ld = channel->peer->ld;
struct htlc_in *hin;
struct secret shared_secret;
struct onionpacket *op;
enum onion_wire failcode;
/* BOLT #2:
*
* - receiving an `amount_msat` equal to 0, OR less than its own `htlc_minimum_msat`:
* - SHOULD fail the channel.
*/
if (amount_msat_eq(added->amount, AMOUNT_MSAT(0))
|| amount_msat_less(added->amount, channel->our_config.htlc_minimum)) {
channel_internal_error(channel,
"trying to add HTLC amount %s"
" but minimum is %s",
type_to_string(tmpctx,
struct amount_msat,
&added->amount),
type_to_string(tmpctx,
struct amount_msat,
&channel->our_config.htlc_minimum));
return false;
}
/* Do the work of extracting shared secret now if possible. */
/* FIXME: We do this *again* in peer_accepted_htlc! */
op = parse_onionpacket(tmpctx, added->onion_routing_packet,
sizeof(added->onion_routing_packet),
&failcode);
if (op) {
if (!ecdh_maybe_blinding(&op->ephemeralkey,
added->blinding, &added->blinding_ss,
&shared_secret)) {
log_debug(channel->log, "htlc %"PRIu64
": can't tweak pubkey", added->id);
return false;
}
}
/* This stays around even if we fail it immediately: it *is*
* part of the current commitment. */
hin = new_htlc_in(channel, channel, added->id, added->amount,
added->cltv_expiry, &added->payment_hash,
op ? &shared_secret : NULL,
added->blinding, &added->blinding_ss,
added->onion_routing_packet);
/* Save an incoming htlc to the wallet */
wallet_htlc_save_in(ld->wallet, channel, hin);
/* Update channel stats */
wallet_channel_stats_incr_in_offered(ld->wallet, channel->dbid,
added->amount);
log_debug(channel->log, "Adding their HTLC %"PRIu64, added->id);
connect_htlc_in(&channel->peer->ld->htlcs_in, hin);
return true;
}
/* The peer doesn't tell us this separately, but logically it's a separate
* step to receiving commitsig */
static bool peer_sending_revocation(struct channel *channel,
struct added_htlc *added,
struct fulfilled_htlc *fulfilled,
struct failed_htlc **failed,
struct changed_htlc *changed)
{
size_t i;
for (i = 0; i < tal_count(added); i++) {
if (!update_in_htlc(channel, added[i].id, SENT_ADD_REVOCATION))
return false;
}
for (i = 0; i < tal_count(fulfilled); i++) {
if (!update_out_htlc(channel, fulfilled[i].id,
SENT_REMOVE_REVOCATION))
return false;
}
for (i = 0; i < tal_count(failed); i++) {
if (!update_out_htlc(channel, failed[i]->id, SENT_REMOVE_REVOCATION))
return false;
}
for (i = 0; i < tal_count(changed); i++) {
if (changed[i].newstate == RCVD_ADD_ACK_COMMIT) {
if (!update_out_htlc(channel, changed[i].id,
SENT_ADD_ACK_REVOCATION))
return false;
} else {
if (!update_in_htlc(channel, changed[i].id,
SENT_REMOVE_ACK_REVOCATION))
return false;
}
}
channel->last_was_revoke = true;
return true;
}
struct deferred_commitsig {
struct channel *channel;
const u8 *msg;
};
static void retry_deferred_commitsig(struct chain_topology *topo,
struct deferred_commitsig *d)
{
peer_got_commitsig(d->channel, d->msg);
tal_free(d);
}
/* This also implies we're sending revocation */
void peer_got_commitsig(struct channel *channel, const u8 *msg)
{
u64 commitnum;
struct fee_states *fee_states;
struct bitcoin_signature commit_sig, *htlc_sigs;
struct added_htlc *added;
struct fulfilled_htlc *fulfilled;
struct failed_htlc **failed;
struct changed_htlc *changed;
struct bitcoin_tx *tx;
size_t i;
struct lightningd *ld = channel->peer->ld;
if (!fromwire_channeld_got_commitsig(msg, msg,
&commitnum,
&fee_states,
&commit_sig,
&htlc_sigs,
&added,
&fulfilled,
&failed,
&changed,
&tx)
|| !fee_states_valid(fee_states, channel->opener)) {
channel_internal_error(channel,
"bad fromwire_channeld_got_commitsig %s",
tal_hex(channel, msg));
return;
}
/* If we're not synced with bitcoin network, we can't accept
* any new HTLCs. We stall at this point, in the hope that it
* won't take long! */
if (added && !topology_synced(ld->topology)) {
struct deferred_commitsig *d;
log_unusual(channel->log,
"Deferring incoming commit until we sync");
/* If subdaemon dies, we want to forget this. */
d = tal(channel->owner, struct deferred_commitsig);
d->channel = channel;
d->msg = tal_dup_talarr(d, u8, msg);
topology_add_sync_waiter(d, ld->topology,
retry_deferred_commitsig, d);
return;
}
tx->chainparams = chainparams;
log_debug(channel->log,
"got commitsig %"PRIu64
": feerate %u, %zu added, %zu fulfilled, %zu failed, %zu changed",
commitnum, get_feerate(fee_states, channel->opener, LOCAL),
tal_count(added), tal_count(fulfilled),
tal_count(failed), tal_count(changed));
/* New HTLCs */
for (i = 0; i < tal_count(added); i++) {
if (!channel_added_their_htlc(channel, &added[i]))
return;
}
/* Save information now for fulfilled & failed HTLCs */
for (i = 0; i < tal_count(fulfilled); i++) {
if (!peer_fulfilled_our_htlc(channel, &fulfilled[i]))
return;
}
for (i = 0; i < tal_count(failed); i++) {
if (!peer_failed_our_htlc(channel, failed[i]))
return;
}
for (i = 0; i < tal_count(changed); i++) {
if (!changed_htlc(channel, &changed[i])) {
channel_internal_error(channel,
"got_commitsig: update failed");
return;
}
}
tal_free(channel->fee_states);
channel->fee_states = tal_steal(channel, fee_states);
adjust_channel_feerate_bounds(channel,
get_feerate(fee_states,
channel->opener,
LOCAL));
/* Since we're about to send revoke, bump state again. */
if (!peer_sending_revocation(channel, added, fulfilled, failed, changed))
return;
if (!peer_save_commitsig_received(channel, commitnum, tx, &commit_sig))
return;
wallet_channel_save(ld->wallet, channel);
tal_free(channel->last_htlc_sigs);
channel->last_htlc_sigs = tal_steal(channel, htlc_sigs);
wallet_htlc_sigs_save(ld->wallet, channel->dbid,
channel->last_htlc_sigs);
/* Tell it we've committed, and to go ahead with revoke. */
msg = towire_channeld_got_commitsig_reply(msg);
subd_send_msg(channel->owner, take(msg));
}
/* Shuffle them over, forgetting the ancient one. */
void update_per_commit_point(struct channel *channel,
const struct pubkey *per_commitment_point)
{
struct channel_info *ci = &channel->channel_info;
ci->old_remote_per_commit = ci->remote_per_commit;
ci->remote_per_commit = *per_commitment_point;
}
struct commitment_revocation_payload {
struct bitcoin_txid commitment_txid;
const struct bitcoin_tx *penalty_tx;
struct wallet *wallet;
u64 channel_id;
u64 commitnum;
};
static void commitment_revocation_hook_serialize(
struct commitment_revocation_payload *payload, struct json_stream *stream)
{
json_add_txid(stream, "commitment_txid", &payload->commitment_txid);
json_add_tx(stream, "penalty_tx", payload->penalty_tx);
}
static void
commitment_revocation_hook_cb(struct commitment_revocation_payload *p STEALS){
wallet_penalty_base_delete(p->wallet, p->channel_id, p->commitnum);
}
static bool
commitment_revocation_hook_deserialize(struct commitment_revocation_payload *p,
const char *buffer,
const jsmntok_t *toks)
{
return true;
}
REGISTER_PLUGIN_HOOK(commitment_revocation,
commitment_revocation_hook_deserialize,
commitment_revocation_hook_cb,
commitment_revocation_hook_serialize,
struct commitment_revocation_payload *);
void peer_got_revoke(struct channel *channel, const u8 *msg)
{
u64 revokenum;
struct secret per_commitment_secret;
struct pubkey next_per_commitment_point;
struct changed_htlc *changed;
enum onion_wire *badonions;
u8 **failmsgs;
size_t i;
struct lightningd *ld = channel->peer->ld;
struct fee_states *fee_states;
struct penalty_base *pbase;
struct commitment_revocation_payload *payload;
struct bitcoin_tx *penalty_tx;
if (!fromwire_channeld_got_revoke(msg, msg,
&revokenum, &per_commitment_secret,
&next_per_commitment_point,
&fee_states,
&changed,
&pbase,
&penalty_tx)
|| !fee_states_valid(fee_states, channel->opener)) {
channel_internal_error(channel, "bad fromwire_channeld_got_revoke %s",
tal_hex(channel, msg));
return;
}
log_debug(channel->log,
"got revoke %"PRIu64": %zu changed",
revokenum, tal_count(changed));
/* Save any immediate failures for after we reply. */
badonions = tal_arrz(msg, enum onion_wire, tal_count(changed));
failmsgs = tal_arrz(msg, u8 *, tal_count(changed));
for (i = 0; i < tal_count(changed); i++) {
/* If we're doing final accept, we need to forward */
if (changed[i].newstate == RCVD_ADD_ACK_REVOCATION) {
peer_accepted_htlc(failmsgs,
channel, changed[i].id, false,
&badonions[i], &failmsgs[i]);
} else {
if (!changed_htlc(channel, &changed[i])) {
channel_internal_error(channel,
"got_revoke: update failed");
return;
}
}
}
if (revokenum >= (1ULL << 48)) {
channel_internal_error(channel, "got_revoke: too many txs %"PRIu64,
revokenum);
return;
}
if (revokenum != revocations_received(&channel->their_shachain.chain)) {
channel_internal_error(channel, "got_revoke: expected %"PRIu64
" got %"PRIu64,
revocations_received(&channel->their_shachain.chain), revokenum);
return;
}
/* BOLT #2:
*
* - if the `per_commitment_secret` was not generated by the protocol
* in [BOLT #3](03-transactions.md#per-commitment-secret-requirements):
* - MAY fail the channel.
*/
if (!wallet_shachain_add_hash(ld->wallet,
&channel->their_shachain,
shachain_index(revokenum),
&per_commitment_secret)) {
channel_fail_permanent(channel,
REASON_PROTOCOL,
"Bad per_commitment_secret %s for %"PRIu64,
type_to_string(msg, struct secret,
&per_commitment_secret),
revokenum);
return;
}
tal_free(channel->fee_states);
channel->fee_states = tal_steal(channel, fee_states);
/* FIXME: Check per_commitment_secret -> per_commit_point */
update_per_commit_point(channel, &next_per_commitment_point);
/* Tell it we've committed, and to go ahead with revoke. */
msg = towire_channeld_got_revoke_reply(msg);
subd_send_msg(channel->owner, take(msg));
/* Now, any HTLCs we need to immediately fail? */
for (i = 0; i < tal_count(changed); i++) {
struct htlc_in *hin;
if (badonions[i]) {
hin = find_htlc_in(&ld->htlcs_in, channel,
changed[i].id);
local_fail_in_htlc_badonion(hin, badonions[i]);
} else if (failmsgs[i]) {
hin = find_htlc_in(&ld->htlcs_in, channel,
changed[i].id);
local_fail_in_htlc(hin, failmsgs[i]);
} else
continue;
// in fact, now we don't know if this htlc is a forward or localpay!
wallet_forwarded_payment_add(ld->wallet,
hin, NULL, NULL,
FORWARD_LOCAL_FAILED,
badonions[i] ? badonions[i]
: fromwire_peektype(failmsgs[i]));
}
wallet_channel_save(ld->wallet, channel);
if (penalty_tx == NULL)
return;
payload = tal(tmpctx, struct commitment_revocation_payload);
payload->commitment_txid = pbase->txid;
payload->penalty_tx = tal_steal(payload, penalty_tx);
payload->wallet = ld->wallet;
payload->channel_id = channel->dbid;
payload->commitnum = pbase->commitment_num;
plugin_hook_call_commitment_revocation(ld, payload);
}
/* FIXME: Load direct from db. */
const struct existing_htlc **peer_htlcs(const tal_t *ctx,
const struct channel *channel)
{
struct existing_htlc **htlcs;
struct htlc_in_map_iter ini;
struct htlc_out_map_iter outi;
struct htlc_in *hin;
struct htlc_out *hout;
struct lightningd *ld = channel->peer->ld;
htlcs = tal_arr(ctx, struct existing_htlc *, 0);
for (hin = htlc_in_map_first(&ld->htlcs_in, &ini);
hin;
hin = htlc_in_map_next(&ld->htlcs_in, &ini)) {
struct failed_htlc *f;
struct existing_htlc *existing;
if (hin->key.channel != channel)
continue;
if (hin->badonion)
f = take(mk_failed_htlc_badonion(NULL, hin, hin->badonion));
else if (hin->failonion)
f = take(mk_failed_htlc(NULL, hin, hin->failonion));
else
f = NULL;
existing = new_existing_htlc(htlcs, hin->key.id, hin->hstate,
hin->msat, &hin->payment_hash,
hin->cltv_expiry,
hin->onion_routing_packet,
hin->blinding,
hin->preimage,
f);
tal_arr_expand(&htlcs, existing);
}
for (hout = htlc_out_map_first(&ld->htlcs_out, &outi);
hout;
hout = htlc_out_map_next(&ld->htlcs_out, &outi)) {
struct failed_htlc *f;
struct existing_htlc *existing;
if (hout->key.channel != channel)
continue;
/* Note that channeld doesn't actually care *why* outgoing
* HTLCs failed, so just use a dummy here. */
if (hout->failonion || hout->failmsg) {
f = take(tal(NULL, struct failed_htlc));
f->id = hout->key.id;
f->sha256_of_onion = tal(f, struct sha256);
memset(f->sha256_of_onion, 0,
sizeof(*f->sha256_of_onion));
f->badonion = BADONION;
f->onion = NULL;
} else
f = NULL;
existing = new_existing_htlc(htlcs, hout->key.id, hout->hstate,
hout->msat, &hout->payment_hash,
hout->cltv_expiry,
hout->onion_routing_packet,
hout->blinding,
hout->preimage,
f);
tal_arr_expand(&htlcs, existing);
}
return cast_const2(const struct existing_htlc **, htlcs);
}
/* If channel is NULL, free them all (for shutdown) */
void free_htlcs(struct lightningd *ld, const struct channel *channel)
{
struct htlc_out_map_iter outi;
struct htlc_out *hout;
struct htlc_in_map_iter ini;
struct htlc_in *hin;
bool deleted;
/* FIXME: Implement check_htlcs to ensure no dangling hout->in ptrs! */
do {
deleted = false;
for (hout = htlc_out_map_first(&ld->htlcs_out, &outi);
hout;
hout = htlc_out_map_next(&ld->htlcs_out, &outi)) {
if (channel && hout->key.channel != channel)
continue;
tal_free(hout);
deleted = true;
}
for (hin = htlc_in_map_first(&ld->htlcs_in, &ini);
hin;
hin = htlc_in_map_next(&ld->htlcs_in, &ini)) {
if (channel && hin->key.channel != channel)
continue;
tal_free(hin);
deleted = true;
}
/* Can skip over elements due to iterating while deleting. */
} while (deleted);
}
/* BOLT #2:
*
* 2. the deadline for offered HTLCs: the deadline after which the channel has
* to be failed and timed out on-chain. This is `G` blocks after the HTLC's
* `cltv_expiry`: 1 or 2 blocks is reasonable.
*/
static u32 htlc_out_deadline(const struct htlc_out *hout)
{
return hout->cltv_expiry + 1;
}
/* BOLT #2:
*
* 3. the deadline for received HTLCs this node has fulfilled: the deadline
* after which the channel has to be failed and the HTLC fulfilled on-chain
* before its `cltv_expiry`. See steps 4-7 above, which imply a deadline of
* `2R+G+S` blocks before `cltv_expiry`: 18 blocks is reasonable.
*/
/* We approximate this, by using half the cltv_expiry_delta (3R+2G+2S),
* rounded up. */
static u32 htlc_in_deadline(const struct lightningd *ld,
const struct htlc_in *hin)
{
return hin->cltv_expiry - (ld->config.cltv_expiry_delta + 1)/2;
}
void htlcs_notify_new_block(struct lightningd *ld, u32 height)
{
bool removed;
/* BOLT #2:
*
* - if an HTLC which it offered is in either node's current
* commitment transaction, AND is past this timeout deadline:
* - MUST fail the channel.
*/
/* FIXME: use db to look this up in one go (earliest deadline per-peer) */
do {
struct htlc_out *hout;
struct htlc_out_map_iter outi;
removed = false;
for (hout = htlc_out_map_first(&ld->htlcs_out, &outi);
hout;
hout = htlc_out_map_next(&ld->htlcs_out, &outi)) {
/* Not timed out yet? */
if (height < htlc_out_deadline(hout))
continue;
/* Peer on chain already? */
if (channel_on_chain(hout->key.channel))
continue;
/* Peer already failed, or we hit it? */
if (hout->key.channel->error)
continue;
channel_fail_permanent(hout->key.channel,
REASON_PROTOCOL,
"Offered HTLC %"PRIu64
" %s cltv %u hit deadline",
hout->key.id,
htlc_state_name(hout->hstate),
hout->cltv_expiry);
removed = true;
}
/* Iteration while removing is safe, but can skip entries! */
} while (removed);
/* BOLT #2:
*
* - for each HTLC it is attempting to fulfill:
* - MUST estimate a fulfillment deadline.
*...
* - if an HTLC it has fulfilled is in either node's current commitment
* transaction, AND is past this fulfillment deadline:
* - MUST fail the channel.
*/
do {
struct htlc_in *hin;
struct htlc_in_map_iter ini;
removed = false;
for (hin = htlc_in_map_first(&ld->htlcs_in, &ini);
hin;
hin = htlc_in_map_next(&ld->htlcs_in, &ini)) {
struct channel *channel = hin->key.channel;
/* Not fulfilled? If overdue, that's their problem... */
if (!hin->preimage)
continue;
/* Not timed out yet? */
if (height < htlc_in_deadline(ld, hin))
continue;
/* Peer on chain already? */
if (channel_on_chain(channel))
continue;
/* Peer already failed, or we hit it? */
if (channel->error)
continue;
channel_fail_permanent(channel,
REASON_PROTOCOL,
"Fulfilled HTLC %"PRIu64
" %s cltv %u hit deadline",
hin->key.id,
htlc_state_name(hin->hstate),
hin->cltv_expiry);
removed = true;
}
/* Iteration while removing is safe, but can skip entries! */
} while (removed);
}
#ifdef COMPAT_V061
static void fixup_hout(struct lightningd *ld, struct htlc_out *hout)
{
const char *fix;
/* We didn't save HTLC failure information to the database. So when
* busy nodes restarted (y'know, our most important users!) they would
* find themselves with missing fields.
*
* Fortunately, most of the network is honest: re-sending an old HTLC
* just causes failure (though we assert() when we try to push the
* failure to the incoming HTLC which has already succeeded!).
*/
/* We care about HTLCs being removed only, not those being added. */
if (hout->hstate < RCVD_REMOVE_HTLC)
return;
/* Successful ones are fine. */
if (hout->preimage)
return;
/* Failed ones (only happens after db fixed!) OK. */
if (hout->failmsg || hout->failonion)
return;
/* payment_preimage for HTLC in *was* stored, so look for that. */
if (hout->in && hout->in->preimage) {
hout->preimage = tal_dup(hout, struct preimage,
hout->in->preimage);
fix = "restoring preimage from incoming HTLC";
} else {
hout->failmsg = towire_temporary_node_failure(hout);
fix = "subsituting temporary node failure";
}
log_broken(ld->log, "HTLC #%"PRIu64" (%s) "
" for amount %s"
" to %s"
" is missing a resolution: %s.",
hout->key.id, htlc_state_name(hout->hstate),
type_to_string(tmpctx, struct amount_msat, &hout->msat),
type_to_string(tmpctx, struct node_id,
&hout->key.channel->peer->id),
fix);
}
void fixup_htlcs_out(struct lightningd *ld)
{
struct htlc_out_map_iter outi;
struct htlc_out *hout;
for (hout = htlc_out_map_first(&ld->htlcs_out, &outi);
hout;
hout = htlc_out_map_next(&ld->htlcs_out, &outi)) {
if (!hout->am_origin)
fixup_hout(ld, hout);
}
}
#endif /* COMPAT_V061 */
void htlcs_resubmit(struct lightningd *ld,
struct htlc_in_map *unconnected_htlcs_in)
{
struct htlc_in *hin;
struct htlc_in_map_iter ini;
enum onion_wire badonion COMPILER_WANTS_INIT("gcc7.4.0 bad, 8.3 OK");
u8 *failmsg;
/* Now retry any which were stuck. */
for (hin = htlc_in_map_first(unconnected_htlcs_in, &ini);
hin;
hin = htlc_in_map_next(unconnected_htlcs_in, &ini)) {
if (hin->hstate != RCVD_ADD_ACK_REVOCATION)
continue;
log_unusual(hin->key.channel->log,
"Replaying old unprocessed HTLC #%"PRIu64,
hin->key.id);
if (!peer_accepted_htlc(tmpctx, hin->key.channel, hin->key.id,
true, &badonion, &failmsg)) {
if (failmsg)
local_fail_in_htlc(hin, failmsg);
else
local_fail_in_htlc_badonion(hin, badonion);
}
}
/* Don't leak memory! */
htlc_in_map_clear(unconnected_htlcs_in);
tal_free(unconnected_htlcs_in);
}
#if DEVELOPER
static struct command_result *json_dev_ignore_htlcs(struct command *cmd,
const char *buffer,
const jsmntok_t *obj UNNEEDED,
const jsmntok_t *params)
{
struct node_id *peerid;
struct peer *peer;
bool *ignore;
if (!param(cmd, buffer, params,
p_req("id", param_node_id, &peerid),
p_req("ignore", param_bool, &ignore),
NULL))
return command_param_failed();
peer = peer_by_id(cmd->ld, peerid);
if (!peer) {
return command_fail(cmd, LIGHTNINGD,
"Could not find channel with that peer");
}
peer->ignore_htlcs = *ignore;
return command_success(cmd, json_stream_success(cmd));
}
static const struct json_command dev_ignore_htlcs = {
"dev-ignore-htlcs",
"developer",
json_dev_ignore_htlcs,
"Set ignoring incoming HTLCs for peer {id} to {ignore}", false,
"Set/unset ignoring of all incoming HTLCs. For testing only."
};
AUTODATA(json_command, &dev_ignore_htlcs);
#endif /* DEVELOPER */
/* Warp this process to ensure the consistent json object structure
* between 'listforwards' API and 'forward_event' notification. */
void json_format_forwarding_object(struct json_stream *response,
const char *fieldname,
const struct forwarding *cur)
{
json_object_start(response, fieldname);
/* See 6d333f16cc0f3aac7097269bf0985b5fa06d59b4: we may have deleted HTLC. */
if (cur->payment_hash)
json_add_sha256(response, "payment_hash", cur->payment_hash);
json_add_short_channel_id(response, "in_channel", &cur->channel_in);
/* This can be unknown if we failed before channel lookup */
if (cur->channel_out.u64 != 0)
json_add_short_channel_id(response, "out_channel",
&cur->channel_out);
json_add_amount_msat_compat(response,
cur->msat_in,
"in_msatoshi", "in_msat");
/* These can be unset (aka zero) if we failed before channel lookup */
if (cur->channel_out.u64 != 0) {
json_add_amount_msat_compat(response,
cur->msat_out,
"out_msatoshi", "out_msat");
json_add_amount_msat_compat(response,
cur->fee,
"fee", "fee_msat");
}
json_add_string(response, "status", forward_status_name(cur->status));
if (cur->failcode != 0) {
json_add_num(response, "failcode", cur->failcode);
json_add_string(response, "failreason",
onion_wire_name(cur->failcode));
}
#ifdef COMPAT_V070
/* If a forwarding doesn't have received_time it was created
* before we added the tracking, do not include it here. */
if (cur->received_time.ts.tv_sec) {
json_add_timeabs(response, "received_time", cur->received_time);
if (cur->resolved_time)
json_add_timeabs(response, "resolved_time", *cur->resolved_time);
}
#else
json_add_timeabs(response, "received_time", cur->received_time);
if (cur->resolved_time)
json_add_timeabs(response, "resolved_time", *cur->resolved_time);
#endif
json_object_end(response);
}
static void listforwardings_add_forwardings(struct json_stream *response, struct wallet *wallet)
{
const struct forwarding *forwardings;
forwardings = wallet_forwarded_payments_get(wallet, tmpctx);
json_array_start(response, "forwards");
for (size_t i=0; i<tal_count(forwardings); i++) {
const struct forwarding *cur = &forwardings[i];
json_format_forwarding_object(response, NULL, cur);
}
json_array_end(response);
tal_free(forwardings);
}
static struct command_result *json_listforwards(struct command *cmd,
const char *buffer,
const jsmntok_t *obj UNNEEDED,
const jsmntok_t *params)
{
struct json_stream *response;
if (!param(cmd, buffer, params, NULL))
return command_param_failed();
response = json_stream_success(cmd);
listforwardings_add_forwardings(response, cmd->ld->wallet);
return command_success(cmd, response);
}
static const struct json_command listforwards_command = {
"listforwards",
"channels",
json_listforwards,
"List all forwarded payments and their information", false,
"List all forwarded payments and their information"
};
AUTODATA(json_command, &listforwards_command);