#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 /* Channel we're still opening. */ struct uncommitted_channel { /* peer->uncommitted_channel == this */ struct peer *peer; /* openingd which is running now */ struct subd *openingd; /* Reserved dbid for if we become a real struct channel */ u64 dbid; /* For logging */ struct log *log; /* Openingd can tell us stuff. */ const char *transient_billboard; /* If we offered channel, this contains information, otherwise NULL */ struct funding_channel *fc; /* Our basepoints for the channel. */ struct basepoints local_basepoints; /* Public key for funding tx. */ struct pubkey local_funding_pubkey; /* These are *not* filled in by new_uncommitted_channel: */ /* Minimum funding depth (if funder == REMOTE). */ u32 minimum_depth; /* Our channel config. */ struct channel_config our_config; }; struct funding_channel { struct command *cmd; /* Which also owns us. */ struct wallet_tx wtx; u64 push_msat; u8 channel_flags; /* Peer we're trying to reach. */ struct pubkey peerid; /* Channel. */ struct uncommitted_channel *uc; }; static void uncommitted_channel_disconnect(struct uncommitted_channel *uc, const char *desc) { u8 *msg = towire_connectctl_peer_disconnected(tmpctx, &uc->peer->id); log_info(uc->log, "%s", desc); subd_send_msg(uc->peer->ld->connectd, msg); if (uc->fc) command_fail(uc->fc->cmd, LIGHTNINGD, "%s", desc); } void kill_uncommitted_channel(struct uncommitted_channel *uc, const char *why) { log_info(uc->log, "Killing openingd: %s", why); /* Close openingd. */ subd_release_channel(uc->openingd, uc); uc->openingd = NULL; uncommitted_channel_disconnect(uc, why); tal_free(uc); } void json_add_uncommitted_channel(struct json_result *response, const struct uncommitted_channel *uc) { u64 msatoshi_total, our_msatoshi; if (!uc) return; /* If we're chatting but no channel, that's shown by connected: True */ if (!uc->fc) return; json_object_start(response, NULL); json_add_string(response, "state", "OPENINGD"); json_add_string(response, "owner", "lightning_openingd"); json_add_string(response, "funding", "LOCAL"); if (uc->transient_billboard) { json_array_start(response, "status"); json_add_string(response, NULL, uc->transient_billboard); json_array_end(response); } msatoshi_total = uc->fc->wtx.amount * 1000; our_msatoshi = msatoshi_total - uc->fc->push_msat; json_add_u64(response, "msatoshi_to_us", our_msatoshi); json_add_u64(response, "msatoshi_total", msatoshi_total); json_object_end(response); } /* Steals fields from uncommitted_channel: returns NULL if can't generate a * key for this channel (shouldn't happen!). */ static struct channel * wallet_commit_channel(struct lightningd *ld, struct uncommitted_channel *uc, struct bitcoin_tx *remote_commit, secp256k1_ecdsa_signature *remote_commit_sig, const struct bitcoin_txid *funding_txid, u16 funding_outnum, u64 funding_satoshi, u64 push_msat, u8 channel_flags, struct channel_info *channel_info, u32 feerate) { struct channel *channel; u64 our_msatoshi; s64 final_key_idx; /* Get a key to use for closing outputs from this tx */ final_key_idx = wallet_get_newindex(ld); if (final_key_idx == -1) { log_broken(uc->log, "Can't get final key index"); return NULL; } if (uc->fc) our_msatoshi = funding_satoshi * 1000 - push_msat; else our_msatoshi = push_msat; /* Feerates begin identical. */ channel_info->feerate_per_kw[LOCAL] = channel_info->feerate_per_kw[REMOTE] = feerate; /* old_remote_per_commit not valid yet, copy valid one. */ channel_info->old_remote_per_commit = channel_info->remote_per_commit; channel = new_channel(uc->peer, uc->dbid, NULL, /* No shachain yet */ CHANNELD_AWAITING_LOCKIN, uc->fc ? LOCAL : REMOTE, uc->log, take(uc->transient_billboard), channel_flags, &uc->our_config, uc->minimum_depth, 1, 1, 0, funding_txid, funding_outnum, funding_satoshi, push_msat, false, /* !remote_funding_locked */ NULL, /* no scid yet */ /* The three arguments below are msatoshi_to_us, * msatoshi_to_us_min, and msatoshi_to_us_max. * Because, this is a newly-funded channel, * all three are same value. */ our_msatoshi, our_msatoshi, /* msatoshi_to_us_min */ our_msatoshi, /* msatoshi_to_us_max */ remote_commit, remote_commit_sig, NULL, /* No HTLC sigs yet */ channel_info, NULL, /* No remote_shutdown_scriptpubkey yet */ final_key_idx, false, NULL, /* No commit sent yet */ /* If we're fundee, could be a little before this * in theory, but it's only used for timing out. */ get_block_height(ld->topology), feerate, feerate, /* We are connected */ true, &uc->local_basepoints, &uc->local_funding_pubkey, NULL); /* Now we finally put it in the database. */ wallet_channel_insert(ld->wallet, channel); return channel; } static void funding_broadcast_failed(struct channel *channel, int exitstatus, const char *err) { channel_internal_error(channel, "Funding broadcast exited with %i: %s", exitstatus, err); } static void opening_funder_finished(struct subd *openingd, const u8 *resp, const int *fds, struct funding_channel *fc) { u8 *msg, *linear; struct channel_info channel_info; struct bitcoin_tx *fundingtx; struct bitcoin_txid funding_txid, expected_txid; struct pubkey changekey; struct crypto_state cs; secp256k1_ecdsa_signature remote_commit_sig; struct bitcoin_tx *remote_commit; u16 funding_outnum; u32 feerate; u64 change_satoshi; struct channel *channel; struct json_result *response; struct lightningd *ld = openingd->ld; struct channel_id cid; assert(tal_count(fds) == 2); /* This is a new channel_info.their_config so set its ID to 0 */ channel_info.their_config.id = 0; if (!fromwire_opening_funder_reply(resp, resp, &channel_info.their_config, &remote_commit, &remote_commit_sig, &cs, &channel_info.theirbase.revocation, &channel_info.theirbase.payment, &channel_info.theirbase.htlc, &channel_info.theirbase.delayed_payment, &channel_info.remote_per_commit, &fc->uc->minimum_depth, &channel_info.remote_fundingkey, &expected_txid, &feerate, &fc->uc->our_config.channel_reserve_satoshis)) { log_broken(fc->uc->log, "bad OPENING_FUNDER_REPLY %s", tal_hex(resp, resp)); command_fail(fc->cmd, LIGHTNINGD, "bad OPENING_FUNDER_REPLY %s", tal_hex(fc->cmd, resp)); goto failed; } log_debug(ld->log, "%s", type_to_string(tmpctx, struct pubkey, &channel_info.remote_per_commit)); /* Generate the funding tx. */ if (fc->wtx.change && !bip32_pubkey(ld->wallet->bip32_base, &changekey, fc->wtx.change_key_index)) fatal("Error deriving change key %u", fc->wtx.change_key_index); fundingtx = funding_tx(tmpctx, &funding_outnum, fc->wtx.utxos, fc->wtx.amount, &fc->uc->local_funding_pubkey, &channel_info.remote_fundingkey, fc->wtx.change, &changekey, ld->wallet->bip32_base); log_debug(fc->uc->log, "Funding tx has %zi inputs, %zu outputs:", tal_count(fundingtx->input), tal_count(fundingtx->output)); for (size_t i = 0; i < tal_count(fundingtx->input); i++) { log_debug(fc->uc->log, "%zi: %"PRIu64" satoshi (%s) %s\n", i, fc->wtx.utxos[i]->amount, fc->wtx.utxos[i]->is_p2sh ? "P2SH" : "SEGWIT", type_to_string(tmpctx, struct bitcoin_txid, &fundingtx->input[i].txid)); } bitcoin_txid(fundingtx, &funding_txid); if (!bitcoin_txid_eq(&funding_txid, &expected_txid)) { log_broken(fc->uc->log, "Funding txid mismatch:" " satoshi %"PRIu64" change %"PRIu64 " changeidx %u" " localkey %s remotekey %s", fc->wtx.amount, fc->wtx.change, fc->wtx.change_key_index, type_to_string(fc, struct pubkey, &fc->uc->local_funding_pubkey), type_to_string(fc, struct pubkey, &channel_info.remote_fundingkey)); command_fail(fc->cmd, JSONRPC2_INVALID_PARAMS, "Funding txid mismatch:" " satoshi %"PRIu64" change %"PRIu64 " changeidx %u" " localkey %s remotekey %s", fc->wtx.amount, fc->wtx.change, fc->wtx.change_key_index, type_to_string(fc, struct pubkey, &fc->uc->local_funding_pubkey), type_to_string(fc, struct pubkey, &channel_info.remote_fundingkey)); goto failed; } /* Steals fields from uc */ channel = wallet_commit_channel(ld, fc->uc, remote_commit, &remote_commit_sig, &funding_txid, funding_outnum, fc->wtx.amount, fc->push_msat, fc->channel_flags, &channel_info, feerate); if (!channel) { command_fail(fc->cmd, LIGHTNINGD, "Key generation failure"); goto failed; } /* Get HSM to sign the funding tx. */ log_debug(channel->log, "Getting HSM to sign funding tx"); msg = towire_hsm_sign_funding(tmpctx, channel->funding_satoshi, fc->wtx.change, fc->wtx.change_key_index, &fc->uc->local_funding_pubkey, &channel_info.remote_fundingkey, fc->wtx.utxos); if (!wire_sync_write(ld->hsm_fd, take(msg))) fatal("Could not write to HSM: %s", strerror(errno)); msg = wire_sync_read(fc, ld->hsm_fd); if (!fromwire_hsm_sign_funding_reply(tmpctx, msg, &fundingtx)) fatal("HSM gave bad sign_funding_reply %s", tal_hex(msg, resp)); /* Extract the change output and add it to the DB */ wallet_extract_owned_outputs(ld->wallet, fundingtx, NULL, &change_satoshi); /* Make sure we recognize our change output by its scriptpubkey in * future. This assumes that we have only two outputs, may not be true * if we add support for multifundchannel */ if (tal_count(fundingtx->output) == 2) txfilter_add_scriptpubkey(ld->owned_txfilter, fundingtx->output[!funding_outnum].script); /* Send it out and watch for confirms. */ broadcast_tx(ld->topology, channel, fundingtx, funding_broadcast_failed); channel_watch_funding(ld, channel); /* Start normal channel daemon. */ peer_start_channeld(channel, &cs, fds[0], fds[1], NULL, false); wallet_confirm_utxos(ld->wallet, fc->wtx.utxos); response = new_json_result(fc->cmd); json_object_start(response, NULL); linear = linearize_tx(response, fundingtx); json_add_hex_talarr(response, "tx", linear); json_add_txid(response, "txid", &channel->funding_txid); derive_channel_id(&cid, &channel->funding_txid, funding_outnum); json_add_string(response, "channel_id", type_to_string(tmpctx, struct channel_id, &cid)); json_object_end(response); command_success(fc->cmd, response); subd_release_channel(openingd, fc->uc); fc->uc->openingd = NULL; /* Frees fc too, and tmpctx */ tal_free(fc->uc); return; failed: close(fds[0]); close(fds[1]); subd_release_channel(openingd, fc->uc); fc->uc->openingd = NULL; /* Frees fc too, and tmpctx */ tal_free(fc->uc); } static void opening_fundee_finished(struct subd *openingd, const u8 *reply, const int *fds, struct uncommitted_channel *uc) { u8 *funding_signed; struct channel_info channel_info; struct crypto_state cs; secp256k1_ecdsa_signature remote_commit_sig; struct bitcoin_tx *remote_commit; struct lightningd *ld = openingd->ld; struct bitcoin_txid funding_txid; u16 funding_outnum; u64 funding_satoshi, push_msat; u32 feerate; u8 channel_flags; struct channel *channel; log_debug(uc->log, "Got opening_fundee_finish_response"); assert(tal_count(fds) == 2); /* This is a new channel_info.their_config, set its ID to 0 */ channel_info.their_config.id = 0; if (!fromwire_opening_fundee(tmpctx, reply, &channel_info.their_config, &remote_commit, &remote_commit_sig, &cs, &channel_info.theirbase.revocation, &channel_info.theirbase.payment, &channel_info.theirbase.htlc, &channel_info.theirbase.delayed_payment, &channel_info.remote_per_commit, &channel_info.remote_fundingkey, &funding_txid, &funding_outnum, &funding_satoshi, &push_msat, &channel_flags, &feerate, &funding_signed, &uc->our_config.channel_reserve_satoshis)) { log_broken(uc->log, "bad OPENING_FUNDEE_REPLY %s", tal_hex(reply, reply)); uncommitted_channel_disconnect(uc, "bad OPENING_FUNDEE_REPLY"); goto failed; } /* openingd should never accept them funding channel in this case. */ if (peer_active_channel(uc->peer)) { log_broken(uc->log, "openingd accepted peer funding channel"); uncommitted_channel_disconnect(uc, "already have active channel"); goto failed; } /* Consumes uc */ channel = wallet_commit_channel(ld, uc, remote_commit, &remote_commit_sig, &funding_txid, funding_outnum, funding_satoshi, push_msat, channel_flags, &channel_info, feerate); if (!channel) { uncommitted_channel_disconnect(uc, "Commit channel failed"); goto failed; } log_debug(channel->log, "Watching funding tx %s", type_to_string(reply, struct bitcoin_txid, &channel->funding_txid)); channel_watch_funding(ld, channel); /* On to normal operation! */ peer_start_channeld(channel, &cs, fds[0], fds[1], funding_signed, false); subd_release_channel(openingd, uc); uc->openingd = NULL; tal_free(uc); return; failed: close(fds[0]); close(fds[1]); tal_free(uc); } static void opening_funder_failed(struct subd *openingd, const u8 *msg, struct uncommitted_channel *uc) { char *desc; if (!fromwire_opening_funder_failed(msg, msg, &desc)) { log_broken(uc->log, "bad OPENING_FUNDER_FAILED %s", tal_hex(tmpctx, msg)); command_fail(uc->fc->cmd, LIGHTNINGD, "bad OPENING_FUNDER_FAILED %s", tal_hex(uc->fc->cmd, msg)); tal_free(uc); return; } command_fail(uc->fc->cmd, LIGHTNINGD, "%s", desc); /* Clear uc->fc, so we can try again, and so we don't fail twice * if they close. */ uc->fc = tal_free(uc->fc); } static void opening_channel_errmsg(struct uncommitted_channel *uc, int peer_fd, int gossip_fd, const struct crypto_state *cs, const struct channel_id *channel_id UNUSED, const char *desc, const u8 *err_for_them UNUSED) { if (peer_fd != -1) { close(peer_fd); close(gossip_fd); } uncommitted_channel_disconnect(uc, desc); tal_free(uc); } /* There's nothing permanent in an unconfirmed transaction */ static void opening_channel_set_billboard(struct uncommitted_channel *uc, bool perm UNUSED, const char *happenings TAKES) { uc->transient_billboard = tal_free(uc->transient_billboard); if (happenings) uc->transient_billboard = tal_strdup(uc, happenings); } static void destroy_uncommitted_channel(struct uncommitted_channel *uc) { if (uc->openingd) { struct subd *openingd = uc->openingd; uc->openingd = NULL; subd_release_channel(openingd, uc); } /* This is how shutdown_subdaemons tells us not to delete from db! */ if (!uc->peer->uncommitted_channel) return; uc->peer->uncommitted_channel = NULL; maybe_delete_peer(uc->peer); } static struct uncommitted_channel * new_uncommitted_channel(struct peer *peer) { struct lightningd *ld = peer->ld; struct uncommitted_channel *uc = tal(ld, struct uncommitted_channel); char *idname; uc->peer = peer; assert(!peer->uncommitted_channel); uc->transient_billboard = NULL; uc->dbid = wallet_get_channel_dbid(ld->wallet); idname = type_to_string(uc, struct pubkey, &uc->peer->id); uc->log = new_log(uc, uc->peer->log_book, "%s chan #%"PRIu64":", idname, uc->dbid); tal_free(idname); uc->fc = NULL; uc->our_config.id = 0; get_channel_basepoints(ld, &uc->peer->id, uc->dbid, &uc->local_basepoints, &uc->local_funding_pubkey); uc->peer->uncommitted_channel = uc; tal_add_destructor(uc, destroy_uncommitted_channel); return uc; } static void channel_config(struct lightningd *ld, struct channel_config *ours, u32 *max_to_self_delay, u64 *min_effective_htlc_capacity_msat) { /* FIXME: depend on feerate. */ *max_to_self_delay = ld->config.locktime_max; /* This is 1c at $1000/BTC */ *min_effective_htlc_capacity_msat = 1000000; /* BOLT #2: * * The sending node SHOULD: *... * - set `dust_limit_satoshis` to a sufficient value to allow * commitment transactions to propagate through the Bitcoin network. */ ours->dust_limit_satoshis = 546; ours->max_htlc_value_in_flight_msat = UINT64_MAX; /* Don't care */ ours->htlc_minimum_msat = 0; /* BOLT #2: * * The sending node SHOULD: * - set `to_self_delay` sufficient to ensure the sender can * irreversibly spend a commitment transaction output, in case of * misbehavior by the receiver. */ ours->to_self_delay = ld->config.locktime_blocks; /* BOLT #2: * * The receiving node MUST fail the channel if: *... * - `max_accepted_htlcs` is greater than 483. */ ours->max_accepted_htlcs = 483; /* This is filled in by lightning_openingd, for consistency. */ ours->channel_reserve_satoshis = -1; } static unsigned int openingd_msg(struct subd *openingd, const u8 *msg, const int *fds) { enum opening_wire_type t = fromwire_peektype(msg); struct uncommitted_channel *uc = openingd->channel; switch (t) { case WIRE_OPENING_FUNDER_REPLY: if (!uc->fc) { log_broken(openingd->log, "Unexpected FUNDER_REPLY %s", tal_hex(tmpctx, msg)); tal_free(openingd); return 0; } if (tal_count(fds) != 2) return 2; opening_funder_finished(openingd, msg, fds, uc->fc); return 0; case WIRE_OPENING_FUNDER_FAILED: if (!uc->fc) { log_broken(openingd->log, "Unexpected FUNDER_FAILED %s", tal_hex(tmpctx, msg)); tal_free(openingd); return 0; } opening_funder_failed(openingd, msg, uc); return 0; case WIRE_OPENING_FUNDEE: if (tal_count(fds) != 2) return 2; opening_fundee_finished(openingd, msg, fds, uc); return 0; /* We send these! */ case WIRE_OPENING_INIT: case WIRE_OPENING_FUNDER: case WIRE_OPENING_CAN_ACCEPT_CHANNEL: break; } log_broken(openingd->log, "Unexpected msg %s: %s", opening_wire_type_name(t), tal_hex(tmpctx, msg)); tal_free(openingd); return 0; } void peer_start_openingd(struct peer *peer, const struct crypto_state *cs, int peer_fd, int gossip_fd, const u8 *send_msg) { int hsmfd; u32 max_to_self_delay; u64 min_effective_htlc_capacity_msat; struct uncommitted_channel *uc; const u8 *msg; assert(!peer->uncommitted_channel); uc = peer->uncommitted_channel = new_uncommitted_channel(peer); hsmfd = hsm_get_client_fd(peer->ld, &uc->peer->id, uc->dbid, HSM_CAP_COMMITMENT_POINT | HSM_CAP_SIGN_REMOTE_TX); uc->openingd = new_channel_subd(peer->ld, "lightning_openingd", uc, uc->log, true, opening_wire_type_name, openingd_msg, opening_channel_errmsg, opening_channel_set_billboard, take(&peer_fd), take(&gossip_fd), take(&hsmfd), NULL); if (!uc->openingd) { uncommitted_channel_disconnect(uc, tal_fmt(tmpctx, "Running lightning_openingd: %s", strerror(errno))); return; } channel_config(peer->ld, &uc->our_config, &max_to_self_delay, &min_effective_htlc_capacity_msat); /* BOLT #2: * * The sender: * - SHOULD set `minimum_depth` to a number of blocks it considers * reasonable to avoid double-spending of the funding transaction. */ uc->minimum_depth = peer->ld->config.anchor_confirms; msg = towire_opening_init(NULL, get_chainparams(peer->ld)->index, &uc->our_config, max_to_self_delay, min_effective_htlc_capacity_msat, cs, &uc->local_basepoints, &uc->local_funding_pubkey, uc->minimum_depth, feerate_min(peer->ld, NULL), feerate_max(peer->ld, NULL), !peer_active_channel(peer), send_msg); subd_send_msg(uc->openingd, take(msg)); } void opening_peer_no_active_channels(struct peer *peer) { assert(!peer_active_channel(peer)); if (peer->uncommitted_channel) { subd_send_msg(peer->uncommitted_channel->openingd, take(towire_opening_can_accept_channel(NULL))); } } /** * json_fund_channel - Entrypoint for funding a channel */ static void json_fund_channel(struct command *cmd, const char *buffer, const jsmntok_t *params) { const jsmntok_t *sattok; struct funding_channel * fc = tal(cmd, struct funding_channel); struct pubkey *id; struct peer *peer; struct channel *channel; u32 feerate_per_kw = try_get_feerate(cmd->ld->topology, FEERATE_NORMAL); u8 *msg; fc->cmd = cmd; fc->uc = NULL; wtx_init(cmd, &fc->wtx); if (!param(fc->cmd, buffer, params, p_req("id", json_tok_pubkey, &id), p_req("satoshi", json_tok_tok, &sattok), NULL)) return; if (!json_tok_wtx(&fc->wtx, buffer, sattok, MAX_FUNDING_SATOSHI)) return; if (!feerate_per_kw) { command_fail(cmd, LIGHTNINGD, "Cannot estimate fees"); return; } peer = peer_by_id(cmd->ld, id); if (!peer) { command_fail(cmd, LIGHTNINGD, "Unknown peer"); return; } channel = peer_active_channel(peer); if (channel) { command_fail(cmd, LIGHTNINGD, "Peer already %s", channel_state_name(channel)); return; } if (!peer->uncommitted_channel) { command_fail(cmd, LIGHTNINGD, "Peer not connected"); return; } if (peer->uncommitted_channel->fc) { command_fail(cmd, LIGHTNINGD, "Already funding channel"); return; } /* FIXME: Support push_msat? */ fc->push_msat = 0; fc->channel_flags = OUR_CHANNEL_FLAGS; if (!wtx_select_utxos(&fc->wtx, feerate_per_kw, BITCOIN_SCRIPTPUBKEY_P2WSH_LEN)) return; assert(fc->wtx.amount <= MAX_FUNDING_SATOSHI); peer->uncommitted_channel->fc = tal_steal(peer->uncommitted_channel, fc); fc->uc = peer->uncommitted_channel; msg = towire_opening_funder(NULL, fc->wtx.amount, fc->push_msat, feerate_per_kw, fc->wtx.change, fc->wtx.change_key_index, fc->channel_flags, fc->wtx.utxos, cmd->ld->wallet->bip32_base); /* Openingd will either succeed, or fail, or tell us the other side * funded first. */ subd_send_msg(peer->uncommitted_channel->openingd, take(msg)); command_still_pending(cmd); } static const struct json_command fund_channel_command = { "fundchannel", json_fund_channel, "Fund channel with {id} using {satoshi} (or 'all') satoshis" }; AUTODATA(json_command, &fund_channel_command);