#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static void update_feerates(struct lightningd *ld, struct channel *channel) { u8 *msg; u32 feerate = unilateral_feerate(ld->topology); /* Nothing to do if we don't know feerate. */ if (!feerate) return; msg = towire_channel_feerates(NULL, feerate, feerate_min(ld, NULL), feerate_max(ld, NULL)); subd_send_msg(channel->owner, take(msg)); } static void try_update_feerates(struct lightningd *ld, struct channel *channel) { /* No point until funding locked in */ if (!channel_fees_can_change(channel)) return; /* Can't if no daemon listening. */ if (!channel->owner) return; update_feerates(ld, channel); } void notify_feerate_change(struct lightningd *ld) { struct peer *peer; /* FIXME: We should notify onchaind about NORMAL fee change in case * it's going to generate more txs. */ list_for_each(&ld->peers, peer, list) { struct channel *channel = peer_active_channel(peer); if (!channel) continue; /* FIXME: We choose not to drop to chain if we can't contact * peer. We *could* do so, however. */ try_update_feerates(ld, channel); } } static void lockin_complete(struct channel *channel) { /* We set this once we're locked in. */ assert(channel->scid); /* We set this once they're locked in. */ assert(channel->remote_funding_locked); /* We might have already started shutting down */ if (channel->state != CHANNELD_AWAITING_LOCKIN) { log_debug(channel->log, "Lockin complete, but state %s", channel_state_name(channel)); return; } channel_set_state(channel, CHANNELD_AWAITING_LOCKIN, CHANNELD_NORMAL); /* Fees might have changed (and we use IMMEDIATE once we're funded), * so update now. */ try_update_feerates(channel->peer->ld, channel); } /* We were informed by channeld that it announced the channel and sent * an update, so we can now start sending a node_announcement. The * first step is to build the provisional announcement and ask the HSM * to sign it. */ static void peer_got_funding_locked(struct channel *channel, const u8 *msg) { struct pubkey next_per_commitment_point; if (!fromwire_channel_got_funding_locked(msg, &next_per_commitment_point)) { channel_internal_error(channel, "bad channel_got_funding_locked %s", tal_hex(channel, msg)); return; } if (channel->remote_funding_locked) { channel_internal_error(channel, "channel_got_funding_locked twice"); return; } update_per_commit_point(channel, &next_per_commitment_point); log_debug(channel->log, "Got funding_locked"); channel->remote_funding_locked = true; if (channel->scid) lockin_complete(channel); } static void peer_got_announcement(struct channel *channel, const u8 *msg) { secp256k1_ecdsa_signature remote_ann_node_sig; secp256k1_ecdsa_signature remote_ann_bitcoin_sig; if (!fromwire_channel_got_announcement(msg, &remote_ann_node_sig, &remote_ann_bitcoin_sig)) { channel_internal_error(channel, "bad channel_got_announcement %s", tal_hex(tmpctx, msg)); return; } wallet_announcement_save(channel->peer->ld->wallet, channel->dbid, &remote_ann_node_sig, &remote_ann_bitcoin_sig); } static void peer_got_shutdown(struct channel *channel, const u8 *msg) { u8 *scriptpubkey; struct lightningd *ld = channel->peer->ld; if (!fromwire_channel_got_shutdown(channel, msg, &scriptpubkey)) { channel_internal_error(channel, "bad channel_got_shutdown %s", tal_hex(msg, msg)); return; } /* FIXME: Add to spec that we must allow repeated shutdown! */ tal_free(channel->shutdown_scriptpubkey[REMOTE]); channel->shutdown_scriptpubkey[REMOTE] = scriptpubkey; /* BOLT #2: * * 1. `OP_DUP` `OP_HASH160` `20` 20-bytes `OP_EQUALVERIFY` `OP_CHECKSIG` * (pay to pubkey hash), OR * 2. `OP_HASH160` `20` 20-bytes `OP_EQUAL` (pay to script hash), OR * 3. `OP_0` `20` 20-bytes (version 0 pay to witness pubkey), OR * 4. `OP_0` `32` 32-bytes (version 0 pay to witness script hash) * * A receiving node: *... * - if the `scriptpubkey` is not in one of the above forms: * - SHOULD fail the connection. */ if (!is_p2pkh(scriptpubkey, NULL) && !is_p2sh(scriptpubkey, NULL) && !is_p2wpkh(scriptpubkey, NULL) && !is_p2wsh(scriptpubkey, NULL)) { channel_fail_permanent(channel, "Bad shutdown scriptpubkey %s", tal_hex(channel, scriptpubkey)); return; } /* If we weren't already shutting down, we are now */ if (channel->state != CHANNELD_SHUTTING_DOWN) channel_set_state(channel, channel->state, CHANNELD_SHUTTING_DOWN); /* TODO(cdecker) Selectively save updated fields to DB */ wallet_channel_save(ld->wallet, channel); } static void channel_fail_fallen_behind(struct channel *channel, const u8 *msg) { if (!fromwire_channel_fail_fallen_behind(channel, msg, cast_const2(struct pubkey **, &channel->future_per_commitment_point))) { channel_internal_error(channel, "bad channel_fail_fallen_behind %s", tal_hex(tmpctx, msg)); return; } /* per_commitment_point is NULL if option_static_remotekey, but we * use its presence as a flag so set it any valid key in that case. */ if (!channel->future_per_commitment_point) { struct pubkey *any = tal(channel, struct pubkey); if (!channel->option_static_remotekey) { channel_internal_error(channel, "bad channel_fail_fallen_behind %s", tal_hex(tmpctx, msg)); return; } if (!pubkey_from_node_id(any, &channel->peer->ld->id)) fatal("Our own id invalid?"); channel->future_per_commitment_point = any; } /* Peer sees this, so send a generic msg about unilateral close. */ channel_fail_permanent(channel, "Awaiting unilateral close"); } static void peer_start_closingd_after_shutdown(struct channel *channel, const u8 *msg, const int *fds) { struct per_peer_state *pps; if (!fromwire_channel_shutdown_complete(tmpctx, msg, &pps)) { channel_internal_error(channel, "bad shutdown_complete: %s", tal_hex(msg, msg)); return; } per_peer_state_set_fds_arr(pps, fds); /* This sets channel->owner, closes down channeld. */ peer_start_closingd(channel, pps, false, NULL); channel_set_state(channel, CHANNELD_SHUTTING_DOWN, CLOSINGD_SIGEXCHANGE); } static void forget(struct channel *channel) { struct command **forgets = tal_steal(tmpctx, channel->forgets); channel->forgets = tal_arr(channel, struct command *, 0); /* Forget the channel. */ delete_channel(channel); for (size_t i = 0; i < tal_count(forgets); i++) { assert(!forgets[i]->json_stream); struct json_stream *response; response = json_stream_success(forgets[i]); json_add_string(response, "cancelled", "Channel open canceled by RPC(after fundchannel_complete)"); was_pending(command_success(forgets[i], response)); } tal_free(forgets); } static void handle_error_channel(struct channel *channel, const u8 *msg) { if (!fromwire_channel_send_error_reply(msg)) { channel_internal_error(channel, "bad send_error_reply: %s", tal_hex(tmpctx, msg)); return; } forget(channel); } void forget_channel(struct channel *channel, const char *why) { struct channel_id cid; derive_channel_id(&cid, &channel->funding_txid, channel->funding_outnum); channel->error = towire_errorfmt(channel, &cid, "%s", why); /* If the peer is connected, we let them know. Otherwise * we just directly remove the channel */ if (channel->owner) subd_send_msg(channel->owner, take(towire_channel_send_error(NULL, why))); else forget(channel); } static unsigned channel_msg(struct subd *sd, const u8 *msg, const int *fds) { enum channel_wire_type t = fromwire_peektype(msg); switch (t) { case WIRE_CHANNEL_SENDING_COMMITSIG: peer_sending_commitsig(sd->channel, msg); break; case WIRE_CHANNEL_GOT_COMMITSIG: peer_got_commitsig(sd->channel, msg); break; case WIRE_CHANNEL_GOT_REVOKE: peer_got_revoke(sd->channel, msg); break; case WIRE_CHANNEL_GOT_FUNDING_LOCKED: peer_got_funding_locked(sd->channel, msg); break; case WIRE_CHANNEL_GOT_ANNOUNCEMENT: peer_got_announcement(sd->channel, msg); break; case WIRE_CHANNEL_GOT_SHUTDOWN: peer_got_shutdown(sd->channel, msg); break; case WIRE_CHANNEL_SHUTDOWN_COMPLETE: /* We expect 3 fds. */ if (!fds) return 3; peer_start_closingd_after_shutdown(sd->channel, msg, fds); break; case WIRE_CHANNEL_FAIL_FALLEN_BEHIND: channel_fail_fallen_behind(sd->channel, msg); break; case WIRE_CHANNEL_SEND_ERROR_REPLY: handle_error_channel(sd->channel, msg); break; #if EXPERIMENTAL_FEATURES case WIRE_GOT_ONIONMSG_TO_US: handle_onionmsg_to_us(sd->channel, msg); break; case WIRE_GOT_ONIONMSG_FORWARD: handle_onionmsg_forward(sd->channel, msg); break; #else case WIRE_GOT_ONIONMSG_TO_US: case WIRE_GOT_ONIONMSG_FORWARD: #endif /* And we never get these from channeld. */ case WIRE_CHANNEL_INIT: case WIRE_CHANNEL_FUNDING_DEPTH: case WIRE_CHANNEL_OFFER_HTLC: case WIRE_CHANNEL_FULFILL_HTLC: case WIRE_CHANNEL_FAIL_HTLC: case WIRE_CHANNEL_GOT_COMMITSIG_REPLY: case WIRE_CHANNEL_GOT_REVOKE_REPLY: case WIRE_CHANNEL_SENDING_COMMITSIG_REPLY: case WIRE_CHANNEL_SEND_SHUTDOWN: case WIRE_CHANNEL_DEV_REENABLE_COMMIT: case WIRE_CHANNEL_FEERATES: case WIRE_CHANNEL_SPECIFIC_FEERATES: case WIRE_CHANNEL_DEV_MEMLEAK: case WIRE_SEND_ONIONMSG: /* Replies go to requests. */ case WIRE_CHANNEL_OFFER_HTLC_REPLY: case WIRE_CHANNEL_DEV_REENABLE_COMMIT_REPLY: case WIRE_CHANNEL_DEV_MEMLEAK_REPLY: case WIRE_CHANNEL_SEND_ERROR: break; } switch ((enum common_wire_type)t) { #if DEVELOPER case WIRE_CUSTOMMSG_IN: handle_custommsg_in(sd->ld, sd->node_id, msg); break; #else case WIRE_CUSTOMMSG_IN: #endif /* We send these. */ case WIRE_CUSTOMMSG_OUT: break; } return 0; } void peer_start_channeld(struct channel *channel, struct per_peer_state *pps, const u8 *funding_signed, bool reconnected) { u8 *initmsg; int hsmfd; const struct existing_htlc **htlcs; struct short_channel_id scid; u64 num_revocations; struct lightningd *ld = channel->peer->ld; const struct config *cfg = &ld->config; bool reached_announce_depth; struct secret last_remote_per_commit_secret; secp256k1_ecdsa_signature *remote_ann_node_sig, *remote_ann_bitcoin_sig; hsmfd = hsm_get_client_fd(ld, &channel->peer->id, channel->dbid, HSM_CAP_SIGN_GOSSIP | HSM_CAP_ECDH | HSM_CAP_COMMITMENT_POINT | HSM_CAP_SIGN_REMOTE_TX); channel_set_owner(channel, new_channel_subd(ld, "lightning_channeld", channel, &channel->peer->id, channel->log, true, channel_wire_type_name, channel_msg, channel_errmsg, channel_set_billboard, take(&pps->peer_fd), take(&pps->gossip_fd), take(&pps->gossip_store_fd), take(&hsmfd), NULL)); if (!channel->owner) { log_broken(channel->log, "Could not subdaemon channel: %s", strerror(errno)); channel_fail_reconnect_later(channel, "Failed to subdaemon channel"); return; } htlcs = peer_htlcs(tmpctx, channel); if (channel->scid) { scid = *channel->scid; reached_announce_depth = is_scid_depth_announceable(&scid, get_block_height(ld->topology)); log_debug(channel->log, "Already have funding locked in%s", reached_announce_depth ? " (and ready to announce)" : ""); } else { log_debug(channel->log, "Waiting for funding confirmations"); memset(&scid, 0, sizeof(scid)); reached_announce_depth = false; } num_revocations = revocations_received(&channel->their_shachain.chain); /* BOLT #2: * - if `next_revocation_number` equals 0: * - MUST set `your_last_per_commitment_secret` to all zeroes * - otherwise: * - MUST set `your_last_per_commitment_secret` to the last * `per_commitment_secret` it received */ if (num_revocations == 0) memset(&last_remote_per_commit_secret, 0, sizeof(last_remote_per_commit_secret)); else if (!shachain_get_secret(&channel->their_shachain.chain, num_revocations-1, &last_remote_per_commit_secret)) { channel_fail_permanent(channel, "Could not get revocation secret %"PRIu64, num_revocations-1); return; } /* Warn once. */ if (ld->config.ignore_fee_limits) log_debug(channel->log, "Ignoring fee limits!"); if (!wallet_remote_ann_sigs_load(tmpctx, channel->peer->ld->wallet, channel->dbid, &remote_ann_node_sig, &remote_ann_bitcoin_sig)) { channel_internal_error(channel, "Could not load remote announcement signatures"); return; } initmsg = towire_channel_init(tmpctx, chainparams, ld->our_features, &channel->funding_txid, channel->funding_outnum, channel->funding, channel->minimum_depth, &channel->our_config, &channel->channel_info.their_config, channel->channel_info.fee_states, feerate_min(ld, NULL), feerate_max(ld, NULL), &channel->last_sig, pps, &channel->channel_info.remote_fundingkey, &channel->channel_info.theirbase, &channel->channel_info.remote_per_commit, &channel->channel_info.old_remote_per_commit, channel->funder, channel->feerate_base, channel->feerate_ppm, channel->our_msat, &channel->local_basepoints, &channel->local_funding_pubkey, &ld->id, &channel->peer->id, cfg->commit_time_ms, cfg->cltv_expiry_delta, channel->last_was_revoke, channel->last_sent_commit, channel->next_index[LOCAL], channel->next_index[REMOTE], num_revocations, channel->next_htlc_id, htlcs, channel->scid != NULL, channel->remote_funding_locked, &scid, reconnected, channel->state == CHANNELD_SHUTTING_DOWN, channel->shutdown_scriptpubkey[REMOTE] != NULL, channel->shutdown_scriptpubkey[LOCAL], channel->channel_flags, funding_signed, reached_announce_depth, &last_remote_per_commit_secret, channel->peer->their_features, channel->remote_upfront_shutdown_script, remote_ann_node_sig, remote_ann_bitcoin_sig, /* Set at channel open, even if not * negotiated now! */ channel->option_static_remotekey, IFDEV(ld->dev_fast_gossip, false), IFDEV(dev_fail_process_onionpacket, false)); /* We don't expect a response: we are triggered by funding_depth_cb. */ subd_send_msg(channel->owner, take(initmsg)); /* On restart, feerate might not be what we expect: adjust now. */ if (channel->funder == LOCAL) try_update_feerates(ld, channel); } bool channel_tell_depth(struct lightningd *ld, struct channel *channel, const struct bitcoin_txid *txid, u32 depth) { const char *txidstr; txidstr = type_to_string(tmpctx, struct bitcoin_txid, txid); /* If not awaiting lockin/announce, it doesn't care any more */ if (channel->state != CHANNELD_AWAITING_LOCKIN && channel->state != CHANNELD_NORMAL) { log_debug(channel->log, "Funding tx %s confirmed, but peer in state %s", txidstr, channel_state_name(channel)); return true; } if (!channel->owner) { log_debug(channel->log, "Funding tx %s confirmed, but peer disconnected", txidstr); return false; } subd_send_msg(channel->owner, take(towire_channel_funding_depth(NULL, channel->scid, depth))); if (channel->remote_funding_locked && channel->state == CHANNELD_AWAITING_LOCKIN && depth >= channel->minimum_depth) lockin_complete(channel); return true; } /* Check if we are the fundee of this channel, the channel * funding transaction is still not yet seen onchain, and * it has been too long since the channel was first opened. * If so, we should forget the channel. */ static bool is_fundee_should_forget(struct lightningd *ld, struct channel *channel, u32 block_height) { u32 max_funding_unconfirmed = ld->max_funding_unconfirmed; /* BOLT #2: * * A non-funding node (fundee): * - SHOULD forget the channel if it does not see the * correct funding transaction after a reasonable timeout. */ /* Only applies if we are fundee. */ if (channel->funder == LOCAL) return false; /* Does not apply if we already saw the funding tx. */ if (channel->scid) return false; /* Not even reached previous starting blocknum. * (e.g. if --rescan option is used) */ if (block_height < channel->first_blocknum) return false; /* Timeout in blocks not yet reached. */ if (block_height - channel->first_blocknum < max_funding_unconfirmed) return false; /* Ah forget it! */ return true; } /* Notify all channels of new blocks. */ void channel_notify_new_block(struct lightningd *ld, u32 block_height) { struct peer *peer; struct channel *channel; struct channel **to_forget = tal_arr(NULL, struct channel *, 0); size_t i; list_for_each (&ld->peers, peer, list) { list_for_each (&peer->channels, channel, list) if (is_fundee_should_forget(ld, channel, block_height)) { tal_arr_expand(&to_forget, channel); } } /* Need to forget in a separate loop, else the above * nested loops may crash due to the last channel of * a peer also deleting the peer, making the inner * loop crash. * list_for_each_safe does not work because it is not * just the freeing of the channel that occurs, but the * potential destruction of the peer that invalidates * memory the inner loop is accessing. */ for (i = 0; i < tal_count(to_forget); ++i) { channel = to_forget[i]; /* Report it first. */ log_unusual(channel->log, "Forgetting channel: " "It has been %"PRIu32" blocks without the " "funding transaction %s getting deeply " "confirmed. " "We are fundee and can forget channel without " "loss of funds.", block_height - channel->first_blocknum, type_to_string(tmpctx, struct bitcoin_txid, &channel->funding_txid)); /* FIXME: Send an error packet for this case! */ /* And forget it. */ delete_channel(channel); } tal_free(to_forget); } static struct channel *find_channel_by_id(const struct peer *peer, const struct channel_id *cid) { struct channel *c; list_for_each(&peer->channels, c, list) { struct channel_id this_cid; derive_channel_id(&this_cid, &c->funding_txid, c->funding_outnum); if (channel_id_eq(&this_cid, cid)) return c; } return NULL; } /* Since this could vanish while we're checking with bitcoind, we need to save * the details and re-lookup. * * channel_id *should* be unique, but it can be set by the counterparty, so * we cannot rely on that! */ struct channel_to_cancel { struct node_id peer; struct channel_id cid; }; static void process_check_funding_broadcast(struct bitcoind *bitcoind, const struct bitcoin_tx_output *txout, void *arg) { struct channel_to_cancel *cc = arg; struct peer *peer; struct channel *cancel; /* Peer could have errored out while we were waiting */ peer = peer_by_id(bitcoind->ld, &cc->peer); if (!peer) return; cancel = find_channel_by_id(peer, &cc->cid); if (!cancel) return; if (txout != NULL) { for (size_t i = 0; i < tal_count(cancel->forgets); i++) was_pending(command_fail(cancel->forgets[i], LIGHTNINGD, "The funding transaction has been broadcast, " "please consider `close` or `dev-fail`! ")); tal_free(cancel->forgets); cancel->forgets = tal_arr(cancel, struct command *, 0); return; } char *error_reason = "Cancel channel by our RPC " "command before funding " "transaction broadcast."; forget_channel(cancel, error_reason); } struct command_result *cancel_channel_before_broadcast(struct command *cmd, const char *buffer, struct peer *peer, const jsmntok_t *cidtok) { struct channel *cancel_channel; struct channel_to_cancel *cc = tal(cmd, struct channel_to_cancel); cc->peer = peer->id; if (!cidtok) { struct channel *channel; cancel_channel = NULL; list_for_each(&peer->channels, channel, list) { if (cancel_channel) { return command_fail(cmd, LIGHTNINGD, "Multiple channels:" " please specify channel_id"); } cancel_channel = channel; } if (!cancel_channel) return command_fail(cmd, LIGHTNINGD, "No channels matching that peer_id"); derive_channel_id(&cc->cid, &cancel_channel->funding_txid, cancel_channel->funding_outnum); } else { if (!json_tok_channel_id(buffer, cidtok, &cc->cid)) return command_fail(cmd, JSONRPC2_INVALID_PARAMS, "Invalid channel_id parameter."); cancel_channel = find_channel_by_id(peer, &cc->cid); if (!cancel_channel) return command_fail(cmd, LIGHTNINGD, "Channel ID not found: '%.*s'", cidtok->end - cidtok->start, buffer + cidtok->start); } if (cancel_channel->funder == REMOTE) return command_fail(cmd, LIGHTNINGD, "Cannot cancel channel that was " "initiated by peer"); /* Check if we broadcast the transaction. (We store the transaction type into DB * before broadcast). */ enum wallet_tx_type type; if (wallet_transaction_type(cmd->ld->wallet, &cancel_channel->funding_txid, &type)) return command_fail(cmd, LIGHTNINGD, "Has the funding transaction been broadcast? " "Please use `close` or `dev-fail` instead."); if (channel_has_htlc_out(cancel_channel) || channel_has_htlc_in(cancel_channel)) { return command_fail(cmd, LIGHTNINGD, "This channel has HTLCs attached and it is " "not safe to cancel. Has the funding transaction " "been broadcast? Please use `close` or `dev-fail` " "instead."); } tal_arr_expand(&cancel_channel->forgets, cmd); /* Check if the transaction is onchain. */ /* Note: The above check and this check can't completely ensure that * the funding transaction isn't broadcast. We can't know if the funding * is broadcast by external wallet and the transaction hasn't been onchain. */ bitcoind_getutxout(cmd->ld->topology->bitcoind, &cancel_channel->funding_txid, cancel_channel->funding_outnum, process_check_funding_broadcast, notleak(cc)); return command_still_pending(cmd); } #if DEVELOPER static struct command_result *json_dev_feerate(struct command *cmd, const char *buffer, const jsmntok_t *obj UNNEEDED, const jsmntok_t *params) { u32 *feerate; struct node_id *id; struct peer *peer; struct json_stream *response; struct channel *channel; const u8 *msg; if (!param(cmd, buffer, params, p_req("id", param_node_id, &id), p_req("feerate", param_number, &feerate), NULL)) return command_param_failed(); peer = peer_by_id(cmd->ld, id); if (!peer) return command_fail(cmd, LIGHTNINGD, "Peer not connected"); channel = peer_active_channel(peer); if (!channel || !channel->owner || channel->state != CHANNELD_NORMAL) return command_fail(cmd, LIGHTNINGD, "Peer bad state"); msg = towire_channel_feerates(NULL, *feerate, feerate_min(cmd->ld, NULL), feerate_max(cmd->ld, NULL)); subd_send_msg(channel->owner, take(msg)); response = json_stream_success(cmd); json_add_node_id(response, "id", id); json_add_u32(response, "feerate", *feerate); return command_success(cmd, response); } static const struct json_command dev_feerate_command = { "dev-feerate", "developer", json_dev_feerate, "Set feerate for {id} to {feerate}" }; AUTODATA(json_command, &dev_feerate_command); #endif /* DEVELOPER */