#include "bitcoin/script.h" #include "bitcoin/tx.h" #include "close_tx.h" #include "commit_tx.h" #include "controlled_time.h" #include "cryptopkt.h" #include "lightningd.h" #include "log.h" #include "names.h" #include "peer.h" #include "protobuf_convert.h" #include "secrets.h" #include "state.h" #include "utils.h" #include #include #include #include #include #include #include #include #define FIXME_STUB(peer) do { log_broken((peer)->dstate->base_log, "%s:%u: Implement %s!", __FILE__, __LINE__, __func__); abort(); } while(0) static void dump_tx(const char *str, const struct bitcoin_tx *tx) { u8 *linear = linearize_tx(NULL, tx); printf("%s:%s\n", str, tal_hexstr(linear, linear, tal_count(linear))); tal_free(linear); } static void dump_key(const char *str, const struct pubkey *key) { printf("%s:%s\n", str, tal_hexstr(NULL, key->der, sizeof(key->der))); } /* Wrap (and own!) member inside Pkt */ static Pkt *make_pkt(const tal_t *ctx, Pkt__PktCase type, const void *msg) { Pkt *pkt = tal(ctx, Pkt); pkt__init(pkt); pkt->pkt_case = type; /* This is a union, so doesn't matter which we assign. */ pkt->error = (Error *)tal_steal(pkt, msg); /* This makes sure all packets are valid. */ #ifndef NDEBUG { size_t len; u8 *packed; Pkt *cpy; len = pkt__get_packed_size(pkt); packed = tal_arr(pkt, u8, len); pkt__pack(pkt, packed); cpy = pkt__unpack(NULL, len, memcheck(packed, len)); assert(cpy); pkt__free_unpacked(cpy, NULL); tal_free(packed); } #endif return pkt; } static void queue_raw_pkt(struct peer *peer, Pkt *pkt, void (*ack_cb)(struct peer *peer, void *arg), void *ack_arg) { size_t n = tal_count(peer->outpkt); tal_resize(&peer->outpkt, n+1); peer->outpkt[n].pkt = pkt; peer->outpkt[n].ack_cb = ack_cb; peer->outpkt[n].ack_arg = ack_arg; /* In case it was waiting for output. */ io_wake(peer); } static void queue_pkt(struct peer *peer, Pkt__PktCase type, const void *msg) { queue_raw_pkt(peer, make_pkt(peer, type, msg), NULL, NULL); } static void queue_pkt_with_ack(struct peer *peer, Pkt__PktCase type, const void *msg, void (*ack_cb)(struct peer *peer, void *arg), void *ack_arg) { queue_raw_pkt(peer, make_pkt(peer, type, msg), ack_cb, ack_arg); } void queue_pkt_open(struct peer *peer, OpenChannel__AnchorOffer anchor) { OpenChannel *o = tal(peer, OpenChannel); /* Set up out commit info now: rest gets done in setup_first_commit * once anchor is established. */ peer->us.commit = talz(peer, struct commit_info); peer->us.commit->revocation_hash = peer->us.next_revocation_hash; peer_get_revocation_hash(peer, 1, &peer->us.next_revocation_hash); open_channel__init(o); o->revocation_hash = sha256_to_proto(o, &peer->us.commit->revocation_hash); o->next_revocation_hash = sha256_to_proto(o, &peer->us.next_revocation_hash); o->commit_key = pubkey_to_proto(o, &peer->us.commitkey); o->final_key = pubkey_to_proto(o, &peer->us.finalkey); o->delay = tal(o, Locktime); locktime__init(o->delay); o->delay->locktime_case = LOCKTIME__LOCKTIME_SECONDS; o->delay->seconds = rel_locktime_to_seconds(&peer->us.locktime); o->initial_fee_rate = peer->us.commit_fee_rate; if (anchor == OPEN_CHANNEL__ANCHOR_OFFER__WILL_CREATE_ANCHOR) assert(peer->us.offer_anchor == CMD_OPEN_WITH_ANCHOR); else { assert(anchor == OPEN_CHANNEL__ANCHOR_OFFER__WONT_CREATE_ANCHOR); assert(peer->us.offer_anchor == CMD_OPEN_WITHOUT_ANCHOR); } o->anch = anchor; o->min_depth = peer->us.mindepth; queue_pkt(peer, PKT__PKT_OPEN, o); } void queue_pkt_anchor(struct peer *peer) { OpenAnchor *a = tal(peer, OpenAnchor); open_anchor__init(a); a->txid = sha256_to_proto(a, &peer->anchor.txid.sha); a->output_index = peer->anchor.index; a->amount = peer->anchor.satoshis; /* This shouldn't happen! */ if (!setup_first_commit(peer)) { queue_pkt_err(peer, pkt_err(peer, "Own anchor has insufficient funds")); return; } /* Sign their commit sig */ peer->them.commit->sig = tal(peer->them.commit, struct bitcoin_signature); peer->them.commit->sig->stype = SIGHASH_ALL; peer_sign_theircommit(peer, peer->them.commit->tx, &peer->them.commit->sig->sig); a->commit_sig = signature_to_proto(a, &peer->them.commit->sig->sig); queue_pkt(peer, PKT__PKT_OPEN_ANCHOR, a); } void queue_pkt_open_commit_sig(struct peer *peer) { OpenCommitSig *s = tal(peer, OpenCommitSig); open_commit_sig__init(s); dump_tx("Creating sig for:", peer->them.commit->tx); dump_key("Using key:", &peer->us.commitkey); peer->them.commit->sig = tal(peer->them.commit, struct bitcoin_signature); peer->them.commit->sig->stype = SIGHASH_ALL; peer_sign_theircommit(peer, peer->them.commit->tx, &peer->them.commit->sig->sig); s->sig = signature_to_proto(s, &peer->them.commit->sig->sig); queue_pkt(peer, PKT__PKT_OPEN_COMMIT_SIG, s); } void queue_pkt_open_complete(struct peer *peer) { OpenComplete *o = tal(peer, OpenComplete); open_complete__init(o); queue_pkt(peer, PKT__PKT_OPEN_COMPLETE, o); } /* Once they ack, we can add it on our side. */ static void add_our_htlc_ourside(struct peer *peer, void *arg) { struct channel_htlc *htlc = arg; /* FIXME: must add even if can't pay fee any more! */ if (!funding_a_add_htlc(peer->us.staging_cstate, htlc->msatoshis, &htlc->expiry, &htlc->rhash, htlc->id)) fatal("FIXME: Failed to add htlc %"PRIu64" to self on ack", htlc->id); tal_free(htlc); } void queue_pkt_htlc_add(struct peer *peer, const struct htlc_progress *htlc_prog) { UpdateAddHtlc *u = tal(peer, UpdateAddHtlc); update_add_htlc__init(u); assert(htlc_prog->stage.type == HTLC_ADD); u->id = htlc_prog->stage.add.htlc.id; u->amount_msat = htlc_prog->stage.add.htlc.msatoshis; u->r_hash = sha256_to_proto(u, &htlc_prog->stage.add.htlc.rhash); u->expiry = abs_locktime_to_proto(u, &htlc_prog->stage.add.htlc.expiry); /* FIXME: routing! */ u->route = tal(u, Routing); routing__init(u->route); /* We're about to send this, so their side will have it from now on. */ if (!funding_b_add_htlc(peer->them.staging_cstate, htlc_prog->stage.add.htlc.msatoshis, &htlc_prog->stage.add.htlc.expiry, &htlc_prog->stage.add.htlc.rhash, htlc_prog->stage.add.htlc.id)) fatal("Could not add HTLC?"); peer_add_htlc_expiry(peer, &htlc_prog->stage.add.htlc.expiry); their_commit_changed(peer); queue_pkt_with_ack(peer, PKT__PKT_UPDATE_ADD_HTLC, u, add_our_htlc_ourside, tal_dup(peer, struct channel_htlc, &htlc_prog->stage.add.htlc)); } /* Once they ack, we can fulfill it on our side. */ static void fulfill_their_htlc_ourside(struct peer *peer, void *arg) { size_t n; n = funding_htlc_by_id(&peer->us.staging_cstate->b, ptr2int(arg)); funding_b_fulfill_htlc(peer->us.staging_cstate, n); } void queue_pkt_htlc_fulfill(struct peer *peer, const struct htlc_progress *htlc_prog) { UpdateFulfillHtlc *f = tal(peer, UpdateFulfillHtlc); size_t n; update_fulfill_htlc__init(f); assert(htlc_prog->stage.type == HTLC_FULFILL); f->id = htlc_prog->stage.fulfill.id; f->r = sha256_to_proto(f, &htlc_prog->stage.fulfill.r); /* We're about to send this, so their side will have it from now on. */ n = funding_htlc_by_id(&peer->them.staging_cstate->a, f->id); funding_a_fulfill_htlc(peer->them.staging_cstate, n); their_commit_changed(peer); queue_pkt_with_ack(peer, PKT__PKT_UPDATE_FULFILL_HTLC, f, fulfill_their_htlc_ourside, int2ptr(f->id)); } /* Once they ack, we can fail it on our side. */ static void fail_their_htlc_ourside(struct peer *peer, void *arg) { size_t n; n = funding_htlc_by_id(&peer->us.staging_cstate->b, ptr2int(arg)); funding_b_fail_htlc(peer->us.staging_cstate, n); } void queue_pkt_htlc_fail(struct peer *peer, const struct htlc_progress *htlc_prog) { UpdateFailHtlc *f = tal(peer, UpdateFailHtlc); size_t n; update_fail_htlc__init(f); assert(htlc_prog->stage.type == HTLC_FAIL); f->id = htlc_prog->stage.fail.id; /* FIXME: reason! */ f->reason = tal(f, FailReason); fail_reason__init(f->reason); /* We're about to send this, so their side will have it from now on. */ n = funding_htlc_by_id(&peer->them.staging_cstate->a, f->id); funding_a_fail_htlc(peer->them.staging_cstate, n); their_commit_changed(peer); queue_pkt_with_ack(peer, PKT__PKT_UPDATE_FAIL_HTLC, f, fail_their_htlc_ourside, int2ptr(f->id)); } /* OK, we're sending a signature for their pending changes. */ void queue_pkt_commit(struct peer *peer) { UpdateCommit *u = tal(peer, UpdateCommit); struct commit_info *ci = talz(peer, struct commit_info); /* Create new commit info for this commit tx. */ ci->prev = peer->them.commit; ci->revocation_hash = peer->them.next_revocation_hash; ci->cstate = copy_funding(ci, peer->them.staging_cstate); ci->tx = create_commit_tx(ci, &peer->them.finalkey, &peer->us.finalkey, &peer->us.locktime, &peer->anchor.txid, peer->anchor.index, peer->anchor.satoshis, &ci->revocation_hash, ci->cstate, &ci->map); log_debug(peer->log, "Signing tx for %u/%u msatoshis, %zu/%zu htlcs", ci->cstate->a.pay_msat, ci->cstate->b.pay_msat, tal_count(ci->cstate->a.htlcs), tal_count(ci->cstate->b.htlcs)); /* BOLT #2: * * A node MUST NOT send an `update_commit` message which does * not include any updates. */ assert(ci->prev->cstate->changes != ci->cstate->changes); ci->sig = tal(ci, struct bitcoin_signature); ci->sig->stype = SIGHASH_ALL; peer_sign_theircommit(peer, ci->tx, &ci->sig->sig); /* Switch to the new commitment. */ peer->them.commit = ci; peer_check_if_cleared(peer); /* Now send message */ update_commit__init(u); u->sig = signature_to_proto(u, &ci->sig->sig); u->ack = peer_outgoing_ack(peer); queue_pkt(peer, PKT__PKT_UPDATE_COMMIT, u); } /* Send a preimage for the old commit tx. The one we've just committed to is * in peer->us.commit. */ void queue_pkt_revocation(struct peer *peer) { UpdateRevocation *u = tal(peer, UpdateRevocation); update_revocation__init(u); assert(peer->commit_tx_counter > 0); assert(peer->us.commit); assert(peer->us.commit->prev); assert(!peer->us.commit->prev->revocation_preimage); /* We have their signature on the current one, right? */ assert(peer->us.commit->sig); peer->us.commit->prev->revocation_preimage = tal(peer->us.commit->prev, struct sha256); peer_get_revocation_preimage(peer, peer->commit_tx_counter-1, peer->us.commit->prev->revocation_preimage); peer_check_if_cleared(peer); u->revocation_preimage = sha256_to_proto(u, peer->us.commit->prev->revocation_preimage); u->next_revocation_hash = sha256_to_proto(u, &peer->us.next_revocation_hash); u->ack = peer_outgoing_ack(peer); queue_pkt(peer, PKT__PKT_UPDATE_REVOCATION, u); } Pkt *pkt_err(struct peer *peer, const char *msg, ...) { Error *e = tal(peer, Error); va_list ap; error__init(e); va_start(ap, msg); e->problem = tal_vfmt(e, msg, ap); va_end(ap); return make_pkt(peer, PKT__PKT_ERROR, e); } void queue_pkt_err(struct peer *peer, Pkt *err) { queue_raw_pkt(peer, err, NULL, NULL); } void queue_pkt_close_clearing(struct peer *peer) { u8 *redeemscript; CloseClearing *c = tal(peer, CloseClearing); close_clearing__init(c); redeemscript = bitcoin_redeem_single(c, &peer->us.finalkey); peer->closing.our_script = scriptpubkey_p2sh(peer, redeemscript); c->scriptpubkey.data = tal_dup_arr(c, u8, peer->closing.our_script, tal_count(peer->closing.our_script), 0); c->scriptpubkey.len = tal_count(c->scriptpubkey.data); queue_pkt(peer, PKT__PKT_CLOSE_CLEARING, c); } void queue_pkt_close_signature(struct peer *peer) { CloseSignature *c = tal(peer, CloseSignature); struct bitcoin_tx *close_tx; struct signature our_close_sig; close_signature__init(c); close_tx = peer_create_close_tx(peer, peer->closing.our_fee); peer_sign_mutual_close(peer, close_tx, &our_close_sig); c->sig = signature_to_proto(c, &our_close_sig); c->close_fee = peer->closing.our_fee; log_info(peer->log, "queue_pkt_close_signature: offered close fee %" PRIu64, c->close_fee); queue_pkt(peer, PKT__PKT_CLOSE_SIGNATURE, c); } Pkt *pkt_err_unexpected(struct peer *peer, const Pkt *pkt) { return pkt_err(peer, "Unexpected packet %s", state_name(pkt->pkt_case)); } /* Process various packets: return an error packet on failure. */ Pkt *accept_pkt_open(struct peer *peer, const Pkt *pkt) { struct rel_locktime locktime; const OpenChannel *o = pkt->open; if (!proto_to_rel_locktime(o->delay, &locktime)) return pkt_err(peer, "Invalid delay"); /* FIXME: handle blocks in locktime */ if (o->delay->locktime_case != LOCKTIME__LOCKTIME_SECONDS) return pkt_err(peer, "Delay in blocks not accepted"); if (o->delay->seconds > peer->dstate->config.rel_locktime_max) return pkt_err(peer, "Delay too great"); if (o->min_depth > peer->dstate->config.anchor_confirms_max) return pkt_err(peer, "min_depth too great"); if (o->initial_fee_rate < peer->dstate->config.commitment_fee_rate_min) return pkt_err(peer, "Commitment fee rate too low"); if (o->anch == OPEN_CHANNEL__ANCHOR_OFFER__WILL_CREATE_ANCHOR) peer->them.offer_anchor = CMD_OPEN_WITH_ANCHOR; else if (o->anch == OPEN_CHANNEL__ANCHOR_OFFER__WONT_CREATE_ANCHOR) peer->them.offer_anchor = CMD_OPEN_WITHOUT_ANCHOR; else return pkt_err(peer, "Unknown offer anchor value"); if (peer->them.offer_anchor == peer->us.offer_anchor) return pkt_err(peer, "Only one side can offer anchor"); if (!proto_to_rel_locktime(o->delay, &peer->them.locktime)) return pkt_err(peer, "Malformed locktime"); peer->them.mindepth = o->min_depth; peer->them.commit_fee_rate = o->initial_fee_rate; if (!proto_to_pubkey(peer->dstate->secpctx, o->commit_key, &peer->them.commitkey)) return pkt_err(peer, "Bad commitkey"); if (!proto_to_pubkey(peer->dstate->secpctx, o->final_key, &peer->them.finalkey)) return pkt_err(peer, "Bad finalkey"); /* Set up their commit info now: rest gets done in setup_first_commit * once anchor is established. */ peer->them.commit = talz(peer, struct commit_info); proto_to_sha256(o->revocation_hash, &peer->them.commit->revocation_hash); proto_to_sha256(o->next_revocation_hash, &peer->them.next_revocation_hash); /* Witness script for anchor. */ peer->anchor.witnessscript = bitcoin_redeem_2of2(peer, &peer->us.commitkey, &peer->them.commitkey); return NULL; } /* Save and check signature. */ static Pkt *check_and_save_commit_sig(struct peer *peer, struct commit_info *ci, const Signature *pb) { assert(!ci->sig); ci->sig = tal(ci, struct bitcoin_signature); ci->sig->stype = SIGHASH_ALL; if (!proto_to_signature(pb, &ci->sig->sig)) return pkt_err(peer, "Malformed signature"); /* Their sig should sign our commit tx. */ if (!check_tx_sig(peer->dstate->secpctx, ci->tx, 0, NULL, 0, peer->anchor.witnessscript, &peer->them.commitkey, ci->sig)) return pkt_err(peer, "Bad signature"); return NULL; } Pkt *accept_pkt_anchor(struct peer *peer, const Pkt *pkt) { const OpenAnchor *a = pkt->open_anchor; /* They must be offering anchor for us to try accepting */ assert(peer->us.offer_anchor == CMD_OPEN_WITHOUT_ANCHOR); assert(peer->them.offer_anchor == CMD_OPEN_WITH_ANCHOR); proto_to_sha256(a->txid, &peer->anchor.txid.sha); peer->anchor.index = a->output_index; peer->anchor.satoshis = a->amount; if (!setup_first_commit(peer)) return pkt_err(peer, "Insufficient funds for fee"); return check_and_save_commit_sig(peer, peer->us.commit, a->commit_sig); } Pkt *accept_pkt_open_commit_sig(struct peer *peer, const Pkt *pkt) { const OpenCommitSig *s = pkt->open_commit_sig; return check_and_save_commit_sig(peer, peer->us.commit, s->sig); } Pkt *accept_pkt_open_complete(struct peer *peer, const Pkt *pkt) { return NULL; } /* * We add changes to both our staging cstate (as they did when they sent * it) and theirs (as they will when we ack it). */ Pkt *accept_pkt_htlc_add(struct peer *peer, const Pkt *pkt) { const UpdateAddHtlc *u = pkt->update_add_htlc; struct sha256 rhash; struct abs_locktime expiry; /* BOLT #2: * * `amount_msat` MUST BE greater than 0. */ if (u->amount_msat == 0) return pkt_err(peer, "Invalid amount_msat"); proto_to_sha256(u->r_hash, &rhash); if (!proto_to_abs_locktime(u->expiry, &expiry)) return pkt_err(peer, "Invalid HTLC expiry"); /* FIXME: Handle block-based expiry! */ if (!abs_locktime_is_seconds(&expiry)) return pkt_err(peer, "HTLC expiry in blocks not supported!"); /* BOLT #2: * * A node MUST NOT add a HTLC if it would result in it * offering more than 300 HTLCs in either commitment transaction. */ if (tal_count(peer->them.staging_cstate->a.htlcs) == 300 || tal_count(peer->us.staging_cstate->b.htlcs) == 300) return pkt_err(peer, "Too many HTLCs"); /* BOLT #2: * * A node MUST NOT set `id` equal to another HTLC which is in * the current staged commitment transaction. */ if (funding_htlc_by_id(&peer->them.staging_cstate->a, u->id) < tal_count(peer->them.staging_cstate->a.htlcs)) return pkt_err(peer, "HTLC id %"PRIu64" clashes for you", u->id); /* FIXME: Assert this... */ /* Note: these should be in sync, so this should be redundant! */ if (funding_htlc_by_id(&peer->us.staging_cstate->b, u->id) < tal_count(peer->us.staging_cstate->b.htlcs)) return pkt_err(peer, "HTLC id %"PRIu64" clashes for us", u->id); /* BOLT #2: * * A node MUST NOT offer `amount_msat` it cannot pay for in * both commitment transactions at the current `fee_rate` (see * "Fee Calculation" ). A node SHOULD fail the connection if * this occurs. */ /* FIXME: This is wrong! We may have already added more txs to * them.staging_cstate, driving that fee up. * We should check against the last version they acknowledged. */ if (!funding_a_add_htlc(peer->them.staging_cstate, u->amount_msat, &expiry, &rhash, u->id)) return pkt_err(peer, "Cannot afford %"PRIu64" milli-satoshis" " in your commitment tx", u->amount_msat); /* If we fail here, we've already changed them.staging_cstate, so * MUST terminate. */ if (!funding_b_add_htlc(peer->us.staging_cstate, u->amount_msat, &expiry, &rhash, u->id)) return pkt_err(peer, "Cannot afford %"PRIu64" milli-satoshis" " in our commitment tx", u->amount_msat); peer_add_htlc_expiry(peer, &expiry); their_commit_changed(peer); /* FIXME: Fees must be sufficient. */ return NULL; } static Pkt *find_commited_htlc(struct peer *peer, uint64_t id, size_t *n_us, size_t *n_them) { /* BOLT #2: * * A node MUST check that `id` corresponds to an HTLC in its * current commitment transaction, and MUST fail the * connection if it does not. */ *n_us = funding_htlc_by_id(&peer->us.commit->cstate->a, id); if (*n_us == tal_count(peer->us.commit->cstate->a.htlcs)) return pkt_err(peer, "Did not find HTLC %"PRIu64, id); /* They must not fail/fulfill twice, so it should be in staging, too. */ *n_us = funding_htlc_by_id(&peer->us.staging_cstate->a, id); if (*n_us == tal_count(peer->us.staging_cstate->a.htlcs)) return pkt_err(peer, "Already removed HTLC %"PRIu64, id); /* FIXME: Assert this... */ /* Note: these should match. */ *n_them = funding_htlc_by_id(&peer->them.staging_cstate->b, id); if (*n_them == tal_count(peer->them.staging_cstate->b.htlcs)) return pkt_err(peer, "Did not find your HTLC %"PRIu64, id); return NULL; } Pkt *accept_pkt_htlc_fail(struct peer *peer, const Pkt *pkt) { const UpdateFailHtlc *f = pkt->update_fail_htlc; size_t n_us, n_them; Pkt *err; err = find_commited_htlc(peer, f->id, &n_us, &n_them); if (err) return err; /* FIXME: Save reason. */ funding_a_fail_htlc(peer->us.staging_cstate, n_us); funding_b_fail_htlc(peer->them.staging_cstate, n_them); their_commit_changed(peer); return NULL; } Pkt *accept_pkt_htlc_fulfill(struct peer *peer, const Pkt *pkt) { const UpdateFulfillHtlc *f = pkt->update_fulfill_htlc; size_t n_us, n_them; struct sha256 r, rhash; Pkt *err; err = find_commited_htlc(peer, f->id, &n_us, &n_them); if (err) return err; /* Now, it must solve the HTLC rhash puzzle. */ proto_to_sha256(f->r, &r); sha256(&rhash, &r, sizeof(r)); if (!structeq(&rhash, &peer->us.staging_cstate->a.htlcs[n_us].rhash)) return pkt_err(peer, "Invalid r for %"PRIu64, f->id); /* Same ID must have same rhash */ assert(structeq(&rhash, &peer->them.staging_cstate->b.htlcs[n_them].rhash)); funding_a_fulfill_htlc(peer->us.staging_cstate, n_us); funding_b_fulfill_htlc(peer->them.staging_cstate, n_them); their_commit_changed(peer); return NULL; } Pkt *accept_pkt_commit(struct peer *peer, const Pkt *pkt) { const UpdateCommit *c = pkt->update_commit; Pkt *err; struct commit_info *ci = talz(peer, struct commit_info); /* Create new commit info for this commit tx. */ ci->prev = peer->us.commit; ci->revocation_hash = peer->us.next_revocation_hash; ci->cstate = copy_funding(ci, peer->us.staging_cstate); ci->tx = create_commit_tx(ci, &peer->us.finalkey, &peer->them.finalkey, &peer->them.locktime, &peer->anchor.txid, peer->anchor.index, peer->anchor.satoshis, &ci->revocation_hash, ci->cstate, &ci->map); /* BOLT #2: * * A node MUST NOT send an `update_commit` message which does * not include any updates. */ if (ci->prev->cstate->changes == ci->cstate->changes) return pkt_err(peer, "Empty commit"); err = check_and_save_commit_sig(peer, ci, c->sig); if (err) return err; /* Switch to the new commitment. */ peer->us.commit = ci; peer->commit_tx_counter++; peer_get_revocation_hash(peer, peer->commit_tx_counter + 1, &peer->us.next_revocation_hash); peer_check_if_cleared(peer); return NULL; } static bool check_preimage(const Sha256Hash *preimage, const struct sha256 *hash) { struct sha256 h; proto_to_sha256(preimage, &h); sha256(&h, &h, sizeof(h)); return structeq(&h, hash); } Pkt *accept_pkt_revocation(struct peer *peer, const Pkt *pkt) { const UpdateRevocation *r = pkt->update_revocation; /* FIXME: Save preimage in shachain too. */ if (!check_preimage(r->revocation_preimage, &peer->them.commit->prev->revocation_hash)) return pkt_err(peer, "complete preimage incorrect"); /* They're revoking the previous one. */ assert(!peer->them.commit->prev->revocation_preimage); peer->them.commit->prev->revocation_preimage = tal(peer->them.commit->prev, struct sha256); proto_to_sha256(r->revocation_preimage, peer->them.commit->prev->revocation_preimage); peer_check_if_cleared(peer); /* Save next revocation hash. */ proto_to_sha256(r->next_revocation_hash, &peer->them.next_revocation_hash); return NULL; } Pkt *accept_pkt_close_clearing(struct peer *peer, const Pkt *pkt) { const CloseClearing *c = pkt->close_clearing; /* FIXME: Filter for non-standardness? */ peer->closing.their_script = tal_dup_arr(peer, u8, c->scriptpubkey.data, c->scriptpubkey.len, 0); return NULL; } Pkt *accept_pkt_close_sig(struct peer *peer, const Pkt *pkt, bool *acked, bool *we_agree) { const CloseSignature *c = pkt->close_signature; struct bitcoin_tx *close_tx; struct bitcoin_signature theirsig; log_info(peer->log, "accept_pkt_close_sig: they offered close fee %" PRIu64, c->close_fee); *acked = *we_agree = false; /* BOLT #2: * * The sender MUST set `close_fee` lower than or equal to the fee of the * final commitment transaction, and MUST set `close_fee` to an even * number of satoshis. */ if ((c->close_fee & 1) || c->close_fee > commit_tx_fee(peer->them.commit->tx, peer->anchor.satoshis)) { return pkt_err(peer, "Invalid close fee"); } /* FIXME: Don't accept tiny fee at all? */ /* BOLT #2: ... otherwise it SHOULD propose a value strictly between the received `close_fee` and its previously-sent `close_fee`. */ if (peer->closing.their_sig) { /* We want more, they should give more. */ if (peer->closing.our_fee > peer->closing.their_fee) { if (c->close_fee <= peer->closing.their_fee) return pkt_err(peer, "Didn't increase close fee"); } else { if (c->close_fee >= peer->closing.their_fee) return pkt_err(peer, "Didn't decrease close fee"); } } /* BOLT #2: * * The receiver MUST check `sig` is valid for the close * transaction with the given `close_fee`, and MUST fail the * connection if it is not. */ theirsig.stype = SIGHASH_ALL; if (!proto_to_signature(c->sig, &theirsig.sig)) return pkt_err(peer, "Invalid signature format"); close_tx = peer_create_close_tx(peer, c->close_fee); if (!check_tx_sig(peer->dstate->secpctx, close_tx, 0, NULL, 0, peer->anchor.witnessscript, &peer->them.commitkey, &theirsig)) return pkt_err(peer, "Invalid signature"); tal_free(peer->closing.their_sig); peer->closing.their_sig = tal_dup(peer, struct bitcoin_signature, &theirsig); peer->closing.their_fee = c->close_fee; if (peer->closing.our_fee == peer->closing.their_fee) { log_info(peer->log, "accept_pkt_close_sig: That's an ack"); *acked = true; } else { /* Adjust our fee to close on their fee. */ u64 sum; /* Beware overflow! */ sum = (u64)peer->closing.our_fee + peer->closing.their_fee; peer->closing.our_fee = sum / 2; if (peer->closing.our_fee & 1) peer->closing.our_fee++; log_info(peer->log, "accept_pkt_close_sig: we change to %"PRIu64, peer->closing.our_fee); /* Corner case: we may now agree with them. */ if (peer->closing.our_fee == peer->closing.their_fee) *we_agree = true; } /* FIXME: Dynamic fee! */ return NULL; }