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39 KiB

#include <bitcoin/tx.h>
#include <ccan/build_assert/build_assert.h>
#include <ccan/crypto/ripemd160/ripemd160.h>
#include <ccan/mem/mem.h>
#include <ccan/tal/str/str.h>
#include <channeld/gen_channel_wire.h>
#include <common/derive_basepoints.h>
#include <common/htlc_wire.h>
#include <common/overflows.h>
#include <common/sphinx.h>
#include <gossipd/gen_gossip_wire.h>
#include <lightningd/chaintopology.h>
#include <lightningd/htlc_end.h>
#include <lightningd/invoice.h>
#include <lightningd/lightningd.h>
#include <lightningd/log.h>
#include <lightningd/pay.h>
#include <lightningd/peer_control.h>
#include <lightningd/peer_htlcs.h>
#include <lightningd/subd.h>
#include <onchaind/gen_onchain_wire.h>
#include <onchaind/onchain_wire.h>
#include <wire/gen_onion_wire.h>
static bool state_update_ok(struct peer *peer,
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) {
peer_internal_error(peer,
"HTLC %s %"PRIu64" invalid update %s->%s",
dir, htlc_id,
htlc_state_name(oldstate),
htlc_state_name(newstate));
return false;
}
log_debug(peer->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 peer *peer,
struct htlc_in *hin,
enum htlc_state newstate)
{
if (!state_update_ok(peer, hin->hstate, newstate, hin->key.id, "in"))
return false;
if (!wallet_htlc_update(peer->ld->wallet, hin->dbid, newstate, hin->preimage))
return false;
hin->hstate = newstate;
htlc_in_check(hin, __func__);
return true;
}
static bool htlc_out_update_state(struct peer *peer,
struct htlc_out *hout,
enum htlc_state newstate)
{
if (!state_update_ok(peer, hout->hstate, newstate, hout->key.id, "out"))
return false;
if (!wallet_htlc_update(peer->ld->wallet, hout->dbid, newstate, NULL))
return false;
hout->hstate = newstate;
htlc_out_check(hout, __func__);
return true;
}
static void fail_in_htlc(struct htlc_in *hin,
enum onion_type malformed,
const u8 *failuremsg)
{
assert(!hin->preimage);
if (malformed)
assert(!failuremsg);
else
assert(failuremsg);
hin->malformed = malformed;
if (failuremsg)
hin->failuremsg = tal_dup_arr(hin, u8, failuremsg, tal_len(failuremsg), 0);
/* We update state now to signal it's in progress, for persistence. */
htlc_in_update_state(hin->key.peer, hin, SENT_REMOVE_HTLC);
/* Tell peer, if we can. */
if (!hin->key.peer->owner)
return;
if (hin->malformed) {
subd_send_msg(hin->key.peer->owner,
take(towire_channel_fail_htlc(hin,
hin->key.id,
hin->malformed,
NULL)));
} else {
u8 *reply;
/* This obfuscates the message, whether local or forwarded. */
reply = wrap_onionreply(hin, &hin->shared_secret,
hin->failuremsg);
subd_send_msg(hin->key.peer->owner,
take(towire_channel_fail_htlc(hin, hin->key.id,
0, reply)));
tal_free(reply);
}
}
static u8 *make_failmsg(const tal_t *ctx, u64 msatoshi,
enum onion_type failcode,
const u8 *channel_update)
{
switch (failcode) {
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_TEMPORARY_CHANNEL_FAILURE:
return towire_temporary_channel_failure(ctx, channel_update);
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);
case WIRE_AMOUNT_BELOW_MINIMUM:
return towire_amount_below_minimum(ctx, msatoshi, channel_update);
case WIRE_FEE_INSUFFICIENT:
return towire_fee_insufficient(ctx, msatoshi, channel_update);
case WIRE_INCORRECT_CLTV_EXPIRY:
/* FIXME: cltv! */
return towire_incorrect_cltv_expiry(ctx, 0, channel_update);
case WIRE_EXPIRY_TOO_SOON:
return towire_expiry_too_soon(ctx, channel_update);
case WIRE_UNKNOWN_PAYMENT_HASH:
return towire_unknown_payment_hash(ctx);
case WIRE_INCORRECT_PAYMENT_AMOUNT:
return towire_incorrect_payment_amount(ctx);
case WIRE_FINAL_EXPIRY_TOO_SOON:
return towire_final_expiry_too_soon(ctx);
case WIRE_FINAL_INCORRECT_CLTV_EXPIRY:
/* FIXME: cltv! */
return towire_final_incorrect_cltv_expiry(ctx, 0);
case WIRE_FINAL_INCORRECT_HTLC_AMOUNT:
return towire_final_incorrect_htlc_amount(ctx, msatoshi);
case WIRE_INVALID_ONION_VERSION:
case WIRE_INVALID_ONION_HMAC:
case WIRE_INVALID_ONION_KEY:
fatal("Bad failmsg for %s", onion_type_name(failcode));
}
abort();
}
/* This is used for cases where we can immediately fail the HTLC. */
static void local_fail_htlc(struct htlc_in *hin, enum onion_type failcode)
{
log_info(hin->key.peer->log, "failed htlc %"PRIu64" code 0x%04x (%s)",
hin->key.id, failcode, onion_type_name(failcode));
if (failcode & BADONION)
fail_in_htlc(hin, failcode, NULL);
else {
u8 *msg;
if (failcode & UPDATE) {
/* FIXME: Ask gossip daemon for channel_update. */
}
msg = make_failmsg(hin, hin->msatoshi, failcode, NULL);
fail_in_htlc(hin, 0, take(create_onionreply(hin, &hin->shared_secret, msg)));
tal_free(msg);
}
}
/* localfail are for handing to the local payer if it's local. */
static void fail_out_htlc(struct htlc_out *hout, const char *localfail)
{
htlc_out_check(hout, __func__);
assert(hout->malformed || hout->failuremsg);
assert(!hout->malformed || !hout->failuremsg);
if (hout->in) {
fail_in_htlc(hout->in, hout->malformed, hout->failuremsg);
} else {
payment_failed(hout->key.peer->ld, hout, localfail);
}
}
/* BOLT #4:
*
* * `amt_to_forward` - The amount in milli-satoshi to forward to the next
* (outgoing) hop specified within the routing information.
*
* This value MUST factor in the computed fee for this particular hop. When
* processing an incoming Sphinx packet along with the HTLC message it's
* encapsulated within, if the following inequality doesn't hold, then the
* HTLC should be rejected as it indicates a prior node in the path has
* deviated from the specified parameters:
*
* incoming_htlc_amt - fee >= amt_to_forward
*
* Where `fee` is calculated according to the receiving node's advertised fee
* schema as described in [BOLT 7](https://github.com/lightningnetwork/lightning-rfc/blob/master/07-routing-gossip.md#htlc-fees), or 0 if this node is the
* final hop.
*/
static bool check_amount(struct htlc_in *hin,
u64 amt_to_forward, u64 amt_in_htlc, u64 fee)
{
if (amt_in_htlc - fee >= amt_to_forward)
return true;
log_debug(hin->key.peer->ld->log, "HTLC %"PRIu64" incorrect amount:"
" %"PRIu64" in, %"PRIu64" out, fee reqd %"PRIu64,
hin->key.id, amt_in_htlc, amt_to_forward, 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 node to both authenticate the information
* specified by the original sender and the parameters of the HTLC forwarded,
* and ensure the original sender is using the current `cltv_expiry_delta` value.
* If there is no next hop, `cltv_expiry_delta` is zero.
* If the values don't correspond, then the HTLC should be failed+rejected as
* this indicates the incoming node has tampered with the intended HTLC
* values, or the origin has an obsolete `cltv_expiry_delta` value.
* The node MUST be consistent in responding to an unexpected
* `outgoing_cltv_value` whether it is the final hop or not, to avoid
* leaking that information.
*/
static bool check_cltv(struct htlc_in *hin,
u32 cltv_expiry, u32 outgoing_cltv_value, u32 delta)
{
if (cltv_expiry - delta == outgoing_cltv_value)
return true;
log_debug(hin->key.peer->ld->log, "HTLC %"PRIu64" incorrect CLTV:"
" %u in, %u out, delta reqd %u",
hin->key.id, cltv_expiry, outgoing_cltv_value, delta);
return false;
}
static void fulfill_htlc(struct htlc_in *hin, const struct preimage *preimage)
{
u8 *msg;
hin->preimage = tal_dup(hin, struct preimage, preimage);
htlc_in_check(hin, __func__);
/* We update state now to signal it's in progress, for persistence. */
htlc_in_update_state(hin->key.peer, hin, SENT_REMOVE_HTLC);
/* No owner? We'll either send to channeld in peer_htlcs, or
* onchaind in onchaind_tell_fulfill. */
if (!hin->key.peer->owner) {
log_debug(hin->key.peer->log, "HTLC fulfilled, but no owner.");
return;
}
if (peer_state_on_chain(hin->key.peer->state)) {
msg = towire_onchain_known_preimage(hin, preimage);
} else {
/* FIXME: fail the peer if it doesn't tell us that htlc
* fulfill is committed before deadline.
*/
msg = towire_channel_fulfill_htlc(hin, hin->key.id, preimage);
}
subd_send_msg(hin->key.peer->owner, take(msg));
}
static void handle_localpay(struct htlc_in *hin,
u32 cltv_expiry,
const struct sha256 *payment_hash,
u64 amt_to_forward,
u32 outgoing_cltv_value)
{
enum onion_type failcode;
struct invoice *invoice;
struct lightningd *ld = hin->key.peer->ld;
/* BOLT #4:
*
* If the `amt_to_forward` is higher than `incoming_htlc_amt` of
* the HTLC at the final hop:
*
* 1. type: 19 (`final_incorrect_htlc_amount`)
* 2. data:
* * [`4`:`incoming_htlc_amt`]
*/
if (!check_amount(hin, amt_to_forward, hin->msatoshi, 0)) {
failcode = WIRE_FINAL_INCORRECT_HTLC_AMOUNT;
goto fail;
}
/* BOLT #4:
*
* If the `outgoing_cltv_value` does not match the `cltv_expiry` of
* the HTLC at the final hop:
*
* 1. type: 18 (`final_incorrect_cltv_expiry`)
* 2. data:
* * [`4`:`cltv_expiry`]
*/
if (!check_cltv(hin, cltv_expiry, outgoing_cltv_value, 0)) {
failcode = WIRE_FINAL_INCORRECT_CLTV_EXPIRY;
goto fail;
}
invoice = find_unpaid(ld->invoices, payment_hash);
if (!invoice) {
failcode = WIRE_UNKNOWN_PAYMENT_HASH;
goto fail;
}
/* BOLT #4:
*
* If the amount paid is less than the amount expected, the final node
* MUST fail the HTLC. If the amount paid is more than twice the
* amount expected, the final node SHOULD fail the HTLC. This allows
* the sender to reduce information leakage by altering the amount,
* without allowing accidental gross overpayment:
*
* 1. type: PERM|16 (`incorrect_payment_amount`)
*/
if (hin->msatoshi < invoice->msatoshi) {
failcode = WIRE_INCORRECT_PAYMENT_AMOUNT;
goto fail;
} else if (hin->msatoshi > invoice->msatoshi * 2) {
failcode = WIRE_INCORRECT_PAYMENT_AMOUNT;
goto fail;
}
/* BOLT #4:
*
* If the `cltv_expiry` is too low, the final node MUST fail the HTLC:
*/
if (get_block_height(ld->topology) + ld->config.deadline_blocks
>= cltv_expiry) {
log_debug(hin->key.peer->log,
"Expiry cltv %u too close to current %u + deadline %u",
cltv_expiry,
get_block_height(ld->topology),
ld->config.deadline_blocks);
failcode = WIRE_FINAL_EXPIRY_TOO_SOON;
goto fail;
}
log_info(ld->log, "Resolving invoice '%s' with HTLC %"PRIu64,
invoice->label, hin->key.id);
fulfill_htlc(hin, &invoice->r);
resolve_invoice(ld, invoice);
return;
fail:
local_fail_htlc(hin, failcode);
}
/*
* 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 hout_subd_died(struct htlc_out *hout)
{
log_debug(hout->key.peer->log,
"Failing HTLC %"PRIu64" due to peer death",
hout->key.id);
hout->failuremsg = make_failmsg(hout, hout->msatoshi,
WIRE_TEMPORARY_CHANNEL_FAILURE,
NULL);
fail_out_htlc(hout, "Outgoing subdaemon died");
}
/* This is where channeld gives us the HTLC id, and also reports if it
* failed immediately. */
static bool rcvd_htlc_reply(struct subd *subd, const u8 *msg, const int *fds,
struct htlc_out *hout)
{
u16 failure_code;
u8 *failurestr;
if (!fromwire_channel_offer_htlc_reply(msg, msg, NULL,
&hout->key.id,
&failure_code,
&failurestr)) {
peer_internal_error(subd->peer, "Bad channel_offer_htlc_reply");
tal_free(hout);
return false;
}
if (failure_code) {
if (!hout->in) {
char *localfail = tal_fmt(msg, "%s: %.*s",
onion_type_name(failure_code),
(int)tal_len(failurestr),
(const char *)failurestr);
payment_failed(hout->key.peer->ld, hout, localfail);
} else
local_fail_htlc(hout->in, failure_code);
return true;
}
if (find_htlc_out(&subd->ld->htlcs_out, hout->key.peer, hout->key.id)) {
peer_internal_error(subd->peer,
"Bad offer_htlc_reply HTLC id %"PRIu64
" is a duplicate",
hout->key.id);
tal_free(hout);
return false;
}
/* 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. */
return true;
}
enum onion_type send_htlc_out(struct peer *out, u64 amount, u32 cltv,
const struct sha256 *payment_hash,
const u8 *onion_routing_packet,
struct htlc_in *in,
struct pay_command *pc,
struct htlc_out **houtp)
{
struct htlc_out *hout;
u8 *msg;
if (!peer_can_add_htlc(out)) {
log_info(out->log, "Attempt to send HTLC but not ready (%s)",
peer_state_name(out->state));
return WIRE_UNKNOWN_NEXT_PEER;
}
if (!out->owner) {
log_info(out->log, "Attempt to send HTLC but unowned (%s)",
peer_state_name(out->state));
return WIRE_TEMPORARY_CHANNEL_FAILURE;
}
/* Make peer's daemon own it, catch if it dies. */
hout = new_htlc_out(out->owner, out, amount, cltv,
payment_hash, onion_routing_packet, in, pc);
tal_add_destructor(hout, hout_subd_died);
msg = towire_channel_offer_htlc(out, amount, cltv, payment_hash,
onion_routing_packet);
subd_req(out->ld, out->owner, take(msg), -1, 0, rcvd_htlc_reply, hout);
if (houtp)
*houtp = hout;
return 0;
}
static void forward_htlc(struct htlc_in *hin,
u32 cltv_expiry,
const struct sha256 *payment_hash,
u64 amt_to_forward,
u32 outgoing_cltv_value,
const struct pubkey *next_hop,
const u8 next_onion[TOTAL_PACKET_SIZE])
{
enum onion_type failcode;
u64 fee;
struct lightningd *ld = hin->key.peer->ld;
struct peer *next = peer_by_id(ld, next_hop);
if (!next) {
failcode = WIRE_UNKNOWN_NEXT_PEER;
goto fail;
}
/* BOLT #7:
*
* The node creating `channel_update` SHOULD accept HTLCs which pay a
* fee equal or greater than:
*
* fee_base_msat + amount_msat * fee_proportional_millionths / 1000000
*/
if (mul_overflows_u64(amt_to_forward,
ld->config.fee_per_satoshi)) {
failcode = WIRE_FEE_INSUFFICIENT;
goto fail;
}
fee = ld->config.fee_base
+ amt_to_forward * ld->config.fee_per_satoshi / 1000000;
if (!check_amount(hin, amt_to_forward, hin->msatoshi, fee)) {
failcode = WIRE_FEE_INSUFFICIENT;
goto fail;
}
if (!check_cltv(hin, cltv_expiry, outgoing_cltv_value,
ld->config.min_htlc_expiry)) {
failcode = WIRE_INCORRECT_CLTV_EXPIRY;
goto fail;
}
/* BOLT #4:
*
* If the cltv-expiry is too near, we tell them the the current channel
* setting for the outgoing channel:
* 1. type: UPDATE|14 (`expiry_too_soon`)
* 2. data:
* * [`2`:`len`]
* * [`len`:`channel_update`]
*/
if (get_block_height(next->ld->topology)
+ next->ld->config.deadline_blocks >= outgoing_cltv_value) {
log_debug(hin->key.peer->log,
"Expiry cltv %u too close to current %u + deadline %u",
outgoing_cltv_value,
get_block_height(next->ld->topology),
next->ld->config.deadline_blocks);
failcode = WIRE_EXPIRY_TOO_SOON;
goto fail;
}
failcode = send_htlc_out(next, amt_to_forward,
outgoing_cltv_value, &hin->payment_hash,
next_onion, hin, NULL, NULL);
if (!failcode)
return;
fail:
local_fail_htlc(hin, failcode);
}
/* Temporary information, while we resolve the next hop */
struct gossip_resolve {
struct short_channel_id next_channel;
u64 amt_to_forward;
u32 outgoing_cltv_value;
u8 *next_onion;
struct htlc_in *hin;
};
/* We received a resolver reply, which gives us the node_ids of the
* channel we want to forward over */
static bool channel_resolve_reply(struct subd *gossip, const u8 *msg,
const int *fds, struct gossip_resolve *gr)
{
struct pubkey *nodes, *peer_id;
if (!fromwire_gossip_resolve_channel_reply(msg, msg, NULL, &nodes)) {
log_broken(gossip->log,
"bad fromwire_gossip_resolve_channel_reply %s",
tal_hex(msg, msg));
return false;
}
if (tal_count(nodes) == 0) {
local_fail_htlc(gr->hin, WIRE_UNKNOWN_NEXT_PEER);
return true;
} else if (tal_count(nodes) != 2) {
log_broken(gossip->log,
"fromwire_gossip_resolve_channel_reply has %zu nodes",
tal_count(nodes));
return false;
}
/* Get the other peer matching the id that is not us */
if (pubkey_cmp(&nodes[0], &gossip->ld->id) == 0) {
peer_id = &nodes[1];
} else {
peer_id = &nodes[0];
}
forward_htlc(gr->hin, gr->hin->cltv_expiry, &gr->hin->payment_hash,
gr->amt_to_forward, gr->outgoing_cltv_value, peer_id,
gr->next_onion);
tal_free(gr);
return true;
}
/* Everyone is committed to this htlc of theirs */
static bool peer_accepted_htlc(struct peer *peer,
u64 id,
enum onion_type *failcode)
{
struct htlc_in *hin;
u8 *req;
struct route_step *rs;
struct onionpacket *op;
const tal_t *tmpctx = tal_tmpctx(peer);
hin = find_htlc_in(&peer->ld->htlcs_in, peer, id);
if (!hin) {
peer_internal_error(peer,
"peer_got_revoke unknown htlc %"PRIu64, id);
return false;
}
if (!htlc_in_update_state(peer, hin, RCVD_ADD_ACK_REVOCATION))
return false;
/* BOLT #2:
*
* A sending node SHOULD fail to route any HTLC added after it
* sent `shutdown`. */
if (peer->state == CHANNELD_SHUTTING_DOWN) {
*failcode = WIRE_PERMANENT_CHANNEL_FAILURE;
goto out;
}
/* channeld tests this, so it should have set ss to zeroes. */
op = parse_onionpacket(tmpctx, hin->onion_routing_packet,
sizeof(hin->onion_routing_packet));
if (!op) {
if (!memeqzero(&hin->shared_secret, sizeof(hin->shared_secret))){
peer_internal_error(peer,
"bad onion in got_revoke: %s",
tal_hexstr(peer, hin->onion_routing_packet,
sizeof(hin->onion_routing_packet)));
tal_free(tmpctx);
return false;
}
/* FIXME: could be bad version, bad key. */
*failcode = WIRE_INVALID_ONION_VERSION;
goto out;
}
/* Channeld sets this to zero if HSM won't ecdh it */
if (memeqzero(&hin->shared_secret, sizeof(hin->shared_secret))) {
*failcode = WIRE_INVALID_ONION_KEY;
goto out;
}
/* If it's crap, not channeld's fault, just fail it */
rs = process_onionpacket(tmpctx, op, hin->shared_secret.data,
hin->payment_hash.u.u8,
sizeof(hin->payment_hash));
if (!rs) {
*failcode = WIRE_INVALID_ONION_HMAC;
goto out;
}
/* Unknown realm isn't a bad onion, it's a normal failure. */
if (rs->hop_data.realm != 0) {
*failcode = WIRE_INVALID_REALM;
goto out;
}
if (rs->nextcase == ONION_FORWARD) {
struct gossip_resolve *gr = tal(peer->ld, struct gossip_resolve);
gr->next_onion = serialize_onionpacket(gr, rs->next);
gr->next_channel = rs->hop_data.channel_id;
gr->amt_to_forward = rs->hop_data.amt_forward;
gr->outgoing_cltv_value = rs->hop_data.outgoing_cltv;
gr->hin = hin;
req = towire_gossip_resolve_channel_request(tmpctx,
&gr->next_channel);
log_debug(peer->log, "Asking gossip to resolve channel %s",
type_to_string(tmpctx, struct short_channel_id,
&gr->next_channel));
subd_req(hin, peer->ld->gossip, req, -1, 0,
channel_resolve_reply, gr);
} else
handle_localpay(hin, hin->cltv_expiry, &hin->payment_hash,
rs->hop_data.amt_forward,
rs->hop_data.outgoing_cltv);
*failcode = 0;
out:
log_debug(peer->log, "their htlc %"PRIu64" %s",
id, *failcode ? onion_type_name(*failcode) : "locked");
tal_free(tmpctx);
return true;
}
static void fulfill_our_htlc_out(struct peer *peer, struct htlc_out *hout,
const struct preimage *preimage)
{
hout->preimage = tal_dup(hout, struct preimage, preimage);
htlc_out_check(hout, __func__);
wallet_htlc_update(peer->ld->wallet, hout->dbid, hout->hstate, preimage);
if (hout->in)
fulfill_htlc(hout->in, preimage);
else
payment_succeeded(peer->ld, hout, preimage);
}
static bool peer_fulfilled_our_htlc(struct peer *peer,
const struct fulfilled_htlc *fulfilled)
{
struct htlc_out *hout;
hout = find_htlc_out(&peer->ld->htlcs_out, peer, fulfilled->id);
if (!hout) {
peer_internal_error(peer,
"fulfilled_our_htlc unknown htlc %"PRIu64,
fulfilled->id);
return false;
}
if (!htlc_out_update_state(peer, hout, RCVD_REMOVE_COMMIT))
return false;
fulfill_our_htlc_out(peer, hout, &fulfilled->payment_preimage);
return true;
}
void onchain_fulfilled_htlc(struct peer *peer, const struct preimage *preimage)
{
struct htlc_out_map_iter outi;
struct htlc_out *hout;
struct sha256 payment_hash;
sha256(&payment_hash, preimage, sizeof(*preimage));
/* FIXME: use db to look this up! */
for (hout = htlc_out_map_first(&peer->ld->htlcs_out, &outi);
hout;
hout = htlc_out_map_next(&peer->ld->htlcs_out, &outi)) {
if (hout->key.peer != peer)
continue;
if (!structeq(&hout->payment_hash, &payment_hash))
continue;
fulfill_our_htlc_out(peer, 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 peer *peer,
const struct failed_htlc *failed)
{
struct htlc_out *hout;
hout = find_htlc_out(&peer->ld->htlcs_out, peer, failed->id);
if (!hout) {
peer_internal_error(peer,
"failed_our_htlc unknown htlc %"PRIu64,
failed->id);
return false;
}
if (!htlc_out_update_state(peer, hout, RCVD_REMOVE_COMMIT))
return false;
log_debug(peer->log, "Our HTLC %"PRIu64" failed (%u)", failed->id,
failed->malformed);
if (failed->malformed)
hout->malformed = failed->malformed;
else
hout->failuremsg = tal_dup_arr(hout, u8, failed->failreason,
tal_len(failed->failreason), 0);
htlc_out_check(hout, __func__);
return true;
}
/* FIXME: Crazy slow! */
struct htlc_out *find_htlc_out_by_ripemd(const struct peer *peer,
const struct ripemd160 *ripemd)
{
struct htlc_out_map_iter outi;
struct htlc_out *hout;
for (hout = htlc_out_map_first(&peer->ld->htlcs_out, &outi);
hout;
hout = htlc_out_map_next(&peer->ld->htlcs_out, &outi)) {
struct ripemd160 hash;
if (hout->key.peer != peer)
continue;
ripemd160(&hash,
&hout->payment_hash, sizeof(hout->payment_hash));
if (structeq(&hash, ripemd))
return hout;
}
return NULL;
}
void onchain_failed_our_htlc(const struct peer *peer,
const struct htlc_stub *htlc,
const char *why)
{
struct htlc_out *hout = find_htlc_out_by_ripemd(peer, &htlc->ripemd);
/* Don't fail twice! */
if (hout->failuremsg)
return;
hout->failuremsg = make_failmsg(hout, hout->msatoshi,
WIRE_PERMANENT_CHANNEL_FAILURE,
NULL);
if (!hout->in) {
char *localfail = tal_fmt(peer, "%s: %s",
onion_type_name(WIRE_PERMANENT_CHANNEL_FAILURE),
why);
payment_failed(hout->key.peer->ld, hout, localfail);
tal_free(localfail);
} else
local_fail_htlc(hout->in, WIRE_PERMANENT_CHANNEL_FAILURE);
}
static void remove_htlc_in(struct peer *peer, struct htlc_in *hin)
{
htlc_in_check(hin, __func__);
assert(hin->failuremsg || hin->preimage || hin->malformed);
log_debug(peer->log, "Removing in HTLC %"PRIu64" state %s %s",
hin->key.id, htlc_state_name(hin->hstate),
hin->failuremsg ? "FAILED"
: hin->malformed ? "MALFORMED"
: "FULFILLED");
/* If we fulfilled their HTLC, credit us. */
if (hin->preimage) {
log_debug(peer->log, "Balance %"PRIu64" -> %"PRIu64,
*peer->our_msatoshi,
*peer->our_msatoshi + hin->msatoshi);
*peer->our_msatoshi += hin->msatoshi;
}
tal_free(hin);
}
static void remove_htlc_out(struct peer *peer, struct htlc_out *hout)
{
htlc_out_check(hout, __func__);
assert(hout->failuremsg || hout->preimage || hout->malformed);
log_debug(peer->log, "Removing out HTLC %"PRIu64" state %s %s",
hout->key.id, htlc_state_name(hout->hstate),
hout->failuremsg ? "FAILED"
: hout->malformed ? "MALFORMED"
: "FULFILLED");
/* If it's failed, now we can forward since it's completely locked-in */
if (!hout->preimage) {
fail_out_htlc(hout, NULL);
} else {
/* We paid for this HTLC, so deduct balance. */
log_debug(peer->log, "Balance %"PRIu64" -> %"PRIu64,
*peer->our_msatoshi,
*peer->our_msatoshi - hout->msatoshi);
*peer->our_msatoshi -= hout->msatoshi;
}
tal_free(hout);
}
static bool update_in_htlc(struct peer *peer, u64 id, enum htlc_state newstate)
{
struct htlc_in *hin;
hin = find_htlc_in(&peer->ld->htlcs_in, peer, id);
if (!hin) {
peer_internal_error(peer, "Can't find in HTLC %"PRIu64, id);
return false;
}
if (!htlc_in_update_state(peer, hin, newstate))
return false;
if (newstate == SENT_REMOVE_ACK_REVOCATION)
remove_htlc_in(peer, hin);
return true;
}
static bool update_out_htlc(struct peer *peer, u64 id, enum htlc_state newstate)
{
struct htlc_out *hout;
hout = find_htlc_out(&peer->ld->htlcs_out, peer, id);
if (!hout) {
peer_internal_error(peer, "Can't find out HTLC %"PRIu64, id);
return false;
}
if (!hout->dbid && !wallet_htlc_save_out(peer->ld->wallet, peer->channel, hout)) {
peer_internal_error(
peer, "Unable to save the htlc_out to the database: %s",
peer->ld->wallet->db->err);
return false;
}
if (!htlc_out_update_state(peer, hout, newstate))
return false;
/* First transition into commitment; now it outlives peer. */
if (newstate == SENT_ADD_COMMIT) {
tal_del_destructor(hout, hout_subd_died);
tal_steal(peer->ld, hout);
} else if (newstate == RCVD_REMOVE_ACK_REVOCATION) {
remove_htlc_out(peer, hout);
}
return true;
}
static bool changed_htlc(struct peer *peer,
const struct changed_htlc *changed)
{
if (htlc_state_owner(changed->newstate) == LOCAL)
return update_out_htlc(peer, changed->id, changed->newstate);
else
return update_in_htlc(peer, changed->id, changed->newstate);
}
static bool peer_save_commitsig_received(struct peer *peer, u64 commitnum)
{
if (commitnum != peer->next_index[LOCAL]) {
peer_internal_error(peer,
"channel_got_commitsig: expected commitnum %"PRIu64
" got %"PRIu64,
peer->next_index[LOCAL], commitnum);
return false;
}
peer->next_index[LOCAL]++;
/* FIXME: Save to database, with sig and HTLCs. */
if (!wallet_channel_save(peer->ld->wallet, peer->channel)) {
fatal("Could not save channel to database: %s",
peer->ld->wallet->db->err);
}
return true;
}
static bool peer_save_commitsig_sent(struct peer *peer, u64 commitnum)
{
if (commitnum != peer->next_index[REMOTE]) {
peer_internal_error(peer,
"channel_sent_commitsig: expected commitnum %"PRIu64
" got %"PRIu64,
peer->next_index[REMOTE], commitnum);
return false;
}
peer->next_index[REMOTE]++;
/* FIXME: Save to database, with sig and HTLCs. */
if (!wallet_channel_save(peer->ld->wallet, peer->channel)) {
fatal("Could not save channel to database: %s",
peer->ld->wallet->db->err);
}
return true;
}
int peer_sending_commitsig(struct peer *peer, const u8 *msg)
{
u64 commitnum;
struct changed_htlc *changed_htlcs;
size_t i, maxid = 0, num_local_added = 0;
secp256k1_ecdsa_signature commit_sig;
secp256k1_ecdsa_signature *htlc_sigs;
if (!fromwire_channel_sending_commitsig(msg, msg, NULL,
&commitnum,
&changed_htlcs,
&commit_sig, &htlc_sigs)) {
peer_internal_error(peer, "bad channel_sending_commitsig %s",
tal_hex(peer, msg));
return -1;
}
for (i = 0; i < tal_count(changed_htlcs); i++) {
if (!changed_htlc(peer, changed_htlcs + i)) {
peer_internal_error(peer,
"channel_sending_commitsig: update failed");
return -1;
}
/* 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 != peer->next_htlc_id + num_local_added - 1) {
peer_internal_error(peer,
"channel_sending_commitsig:"
" Added %"PRIu64", maxid now %"PRIu64
" from %"PRIu64,
num_local_added, maxid, peer->next_htlc_id);
return -1;
}
/* FIXME: Save to db */
peer->next_htlc_id += num_local_added;
}
if (!peer_save_commitsig_sent(peer, commitnum))
return -1;
/* Last was commit. */
peer->last_was_revoke = false;
tal_free(peer->last_sent_commit);
peer->last_sent_commit = tal_steal(peer, changed_htlcs);
/* Tell it we've got it, and to go ahead with commitment_signed. */
subd_send_msg(peer->owner,
take(towire_channel_sending_commitsig_reply(msg)));
return 0;
}
static void added_their_htlc(struct peer *peer,
const struct added_htlc *added,
const struct secret *shared_secret)
{
struct htlc_in *hin;
/* This stays around even if we fail it immediately: it *is*
* part of the current commitment. */
hin = new_htlc_in(peer, peer, added->id, added->amount_msat,
added->cltv_expiry, &added->payment_hash,
shared_secret, added->onion_routing_packet);
/* Save an incoming htlc to the wallet */
wallet_htlc_save_in(peer->ld->wallet, peer->channel, hin);
log_debug(peer->log, "Adding their HTLC %"PRIu64, added->id);
connect_htlc_in(&peer->ld->htlcs_in, hin);
}
/* The peer doesn't tell us this separately, but logically it's a separate
* step to receiving commitsig */
static bool peer_sending_revocation(struct peer *peer,
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(peer, added[i].id, SENT_ADD_REVOCATION))
return false;
}
for (i = 0; i < tal_count(fulfilled); i++) {
if (!update_out_htlc(peer, fulfilled[i].id,
SENT_REMOVE_REVOCATION))
return false;
}
for (i = 0; i < tal_count(failed); i++) {
if (!update_out_htlc(peer, 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(peer, changed[i].id,
SENT_ADD_ACK_REVOCATION))
return false;
} else {
if (!update_in_htlc(peer, changed[i].id,
SENT_REMOVE_ACK_REVOCATION))
return false;
}
}
peer->last_was_revoke = true;
return true;
}
/* This also implies we're sending revocation */
int peer_got_commitsig(struct peer *peer, const u8 *msg)
{
u64 commitnum;
secp256k1_ecdsa_signature commit_sig;
secp256k1_ecdsa_signature *htlc_sigs;
struct added_htlc *added;
struct secret *shared_secrets;
struct fulfilled_htlc *fulfilled;
struct failed_htlc *failed;
struct changed_htlc *changed;
struct bitcoin_tx *tx = tal(msg, struct bitcoin_tx);
size_t i;
if (!fromwire_channel_got_commitsig(msg, msg, NULL,
&commitnum,
&commit_sig,
&htlc_sigs,
&added,
&shared_secrets,
&fulfilled,
&failed,
&changed,
tx)) {
peer_internal_error(peer,
"bad fromwire_channel_got_commitsig %s",
tal_hex(peer, msg));
return -1;
}
log_debug(peer->log,
"got commitsig %"PRIu64
": %zu added, %zu fulfilled, %zu failed, %zu changed",
commitnum, tal_count(added), tal_count(fulfilled),
tal_count(failed), tal_count(changed));
/* FIXME: store commit & htlc signature information. */
/* New HTLCs */
for (i = 0; i < tal_count(added); i++)
added_their_htlc(peer, &added[i], &shared_secrets[i]);
/* Save information now for fulfilled & failed HTLCs */
for (i = 0; i < tal_count(fulfilled); i++) {
if (!peer_fulfilled_our_htlc(peer, &fulfilled[i]))
return -1;
}
for (i = 0; i < tal_count(failed); i++) {
if (!peer_failed_our_htlc(peer, &failed[i]))
return -1;
}
for (i = 0; i < tal_count(changed); i++) {
if (!changed_htlc(peer, &changed[i])) {
peer_internal_error(peer,
"got_commitsig: update failed");
return -1;
}
}
/* Since we're about to send revoke, bump state again. */
if (!peer_sending_revocation(peer, added, fulfilled, failed, changed))
return -1;
if (!peer_save_commitsig_received(peer, commitnum))
return -1;
peer_last_tx(peer, tx, &commit_sig);
/* FIXME: Put these straight in the db! */
tal_free(peer->last_htlc_sigs);
peer->last_htlc_sigs = tal_steal(peer, htlc_sigs);
/* Tell it we've committed, and to go ahead with revoke. */
msg = towire_channel_got_commitsig_reply(msg);
subd_send_msg(peer->owner, take(msg));
return 0;
}
/* Shuffle them over, forgetting the ancient one. */
void update_per_commit_point(struct peer *peer,
const struct pubkey *per_commitment_point)
{
struct channel_info *ci = peer->channel_info;
ci->old_remote_per_commit = ci->remote_per_commit;
ci->remote_per_commit = *per_commitment_point;
}
int peer_got_revoke(struct peer *peer, const u8 *msg)
{
u64 revokenum;
struct sha256 per_commitment_secret;
struct pubkey next_per_commitment_point;
struct changed_htlc *changed;
enum onion_type *failcodes;
size_t i;
if (!fromwire_channel_got_revoke(msg, msg, NULL,
&revokenum, &per_commitment_secret,
&next_per_commitment_point,
&changed)) {
peer_internal_error(peer, "bad fromwire_channel_got_revoke %s",
tal_hex(peer, msg));
return -1;
}
log_debug(peer->log,
"got revoke %"PRIu64": %zu changed",
revokenum, tal_count(changed));
/* Save any immediate failures for after we reply. */
failcodes = tal_arrz(msg, enum onion_type, 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) {
if (!peer_accepted_htlc(peer, changed[i].id,
&failcodes[i]))
return -1;
} else {
if (!changed_htlc(peer, &changed[i])) {
peer_internal_error(peer,
"got_revoke: update failed");
return -1;
}
}
}
if (revokenum >= (1ULL << 48)) {
peer_internal_error(peer, "got_revoke: too many txs %"PRIu64,
revokenum);
return -1;
}
if (revokenum != revocations_received(&peer->their_shachain.chain)) {
peer_internal_error(peer, "got_revoke: expected %"PRIu64
" got %"PRIu64,
revocations_received(&peer->their_shachain.chain), revokenum);
return -1;
}
/* BOLT #2:
*
* A receiving node MAY fail if the `per_commitment_secret` was not
* generated by the protocol in [BOLT #3]
*/
if (!wallet_shachain_add_hash(peer->ld->wallet, &peer->their_shachain,
shachain_index(revokenum),
&per_commitment_secret)) {
char *err = tal_fmt(peer,
"Bad per_commitment_secret %s for %"PRIu64,
type_to_string(msg, struct sha256,
&per_commitment_secret),
revokenum);
peer_fail_permanent(peer, take((u8 *)err));
return -1;
}
/* FIXME: Check per_commitment_secret -> per_commit_point */
update_per_commit_point(peer, &next_per_commitment_point);
/* FIXME: Commit shachain and next_per_commit_point to db */
/* Tell it we've committed, and to go ahead with revoke. */
msg = towire_channel_got_revoke_reply(msg);
subd_send_msg(peer->owner, take(msg));
/* Now, any HTLCs we need to immediately fail? */
for (i = 0; i < tal_count(changed); i++) {
struct htlc_in *hin;
if (!failcodes[i])
continue;
hin = find_htlc_in(&peer->ld->htlcs_in, peer, changed[i].id);
local_fail_htlc(hin, failcodes[i]);
}
if (!wallet_channel_save(peer->ld->wallet, peer->channel)) {
fatal("Could not save channel to database: %s",
peer->ld->wallet->db->err);
}
return 0;
}
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 add_htlc(struct added_htlc **htlcs,
enum htlc_state **htlc_states,
u64 id,
u64 amount_msat,
const struct sha256 *payment_hash,
u32 cltv_expiry,
const u8 onion_routing_packet[TOTAL_PACKET_SIZE],
enum htlc_state state)
{
struct added_htlc *a;
enum htlc_state *h;
a = tal_arr_append(htlcs);
h = tal_arr_append(htlc_states);
a->id = id;
a->amount_msat = amount_msat;
a->payment_hash = *payment_hash;
a->cltv_expiry = cltv_expiry;
memcpy(a->onion_routing_packet, onion_routing_packet,
sizeof(a->onion_routing_packet));
*h = state;
}
static void add_fulfill(u64 id, enum side side,
const struct preimage *payment_preimage,
struct fulfilled_htlc **fulfilled_htlcs,
enum side **fulfilled_sides)
{
struct fulfilled_htlc *f;
enum side *s;
f = tal_arr_append(fulfilled_htlcs);
s = tal_arr_append(fulfilled_sides);
f->id = id;
f->payment_preimage = *payment_preimage;
*s = side;
}
static void add_fail(u64 id, enum side side,
const u8 *failuremsg,
struct failed_htlc **failed_htlcs,
enum side **failed_sides)
{
struct failed_htlc *f;
enum side *s;
f = tal_arr_append(failed_htlcs);
s = tal_arr_append(failed_sides);
f->id = id;
f->failreason = tal_dup_arr(*failed_htlcs, u8,
failuremsg, tal_len(failuremsg), 0);
*s = side;
}
/* FIXME: Load direct from db. */
void peer_htlcs(const tal_t *ctx,
const struct peer *peer,
struct added_htlc **htlcs,
enum htlc_state **htlc_states,
struct fulfilled_htlc **fulfilled_htlcs,
enum side **fulfilled_sides,
struct failed_htlc **failed_htlcs,
enum side **failed_sides)
{
struct htlc_in_map_iter ini;
struct htlc_out_map_iter outi;
struct htlc_in *hin;
struct htlc_out *hout;
*htlcs = tal_arr(ctx, struct added_htlc, 0);
*htlc_states = tal_arr(ctx, enum htlc_state, 0);
*fulfilled_htlcs = tal_arr(ctx, struct fulfilled_htlc, 0);
*fulfilled_sides = tal_arr(ctx, enum side, 0);
*failed_htlcs = tal_arr(ctx, struct failed_htlc, 0);
*failed_sides = tal_arr(ctx, enum side, 0);
for (hin = htlc_in_map_first(&peer->ld->htlcs_in, &ini);
hin;
hin = htlc_in_map_next(&peer->ld->htlcs_in, &ini)) {
if (hin->key.peer != peer)
continue;
add_htlc(htlcs, htlc_states,
hin->key.id, hin->msatoshi, &hin->payment_hash,
hin->cltv_expiry, hin->onion_routing_packet,
hin->hstate);
if (hin->failuremsg)
add_fail(hin->key.id, REMOTE, hin->failuremsg,
failed_htlcs, failed_sides);
if (hin->preimage)
add_fulfill(hin->key.id, REMOTE, hin->preimage,
fulfilled_htlcs, fulfilled_sides);
}
for (hout = htlc_out_map_first(&peer->ld->htlcs_out, &outi);
hout;
hout = htlc_out_map_next(&peer->ld->htlcs_out, &outi)) {
if (hout->key.peer != peer)
continue;
add_htlc(htlcs, htlc_states,
hout->key.id, hout->msatoshi, &hout->payment_hash,
hout->cltv_expiry, hout->onion_routing_packet,
hout->hstate);
if (hout->failuremsg)
add_fail(hout->key.id, LOCAL, hout->failuremsg,
failed_htlcs, failed_sides);
if (hout->preimage)
add_fulfill(hout->key.id, LOCAL, hout->preimage,
fulfilled_htlcs, fulfilled_sides);
}
}