#include "bitcoin/feerate.h" #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 #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 initially owns us until openingd request */ struct wallet_tx *wtx; struct amount_msat push; struct amount_sat funding; u8 channel_flags; /* Variables we need to compose fields in cmd's response */ const char *hextx; struct channel_id cid; /* Peer we're trying to reach. */ struct pubkey peerid; /* Channel, subsequent owner of us */ struct uncommitted_channel *uc; /* Whether or not this is in the middle of getting funded */ bool inflight; /* Any commands trying to cancel us. */ struct command **cancels; }; 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 && uc->fc->cmd) was_pending(command_fail(uc->fc->cmd, LIGHTNINGD, "%s", desc)); notify_disconnect(uc->peer->ld, &uc->peer->id); } 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_stream *response, const struct uncommitted_channel *uc) { struct amount_msat total, ours; 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); } /* These should never fail. */ if (amount_sat_to_msat(&total, uc->fc->funding) && amount_msat_sub(&ours, total, uc->fc->push)) { json_add_amount_msat_compat(response, ours, "msatoshi_to_us", "to_us_msat"); json_add_amount_msat_compat(response, total, "msatoshi_total", "total_msat"); } 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, struct bitcoin_signature *remote_commit_sig, const struct bitcoin_txid *funding_txid, u16 funding_outnum, struct amount_sat funding, struct amount_msat push, u8 channel_flags, struct channel_info *channel_info, u32 feerate, const u8 *remote_upfront_shutdown_script) { struct channel *channel; struct amount_msat our_msat; 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) { if (!amount_sat_sub_msat(&our_msat, funding, push)) { log_broken(uc->log, "push %s exceeds funding %s", type_to_string(tmpctx, struct amount_msat, &push), type_to_string(tmpctx, struct amount_sat, &funding)); return NULL; } } else our_msat = push; /* 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, push, 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_msat, our_msat, /* msat_to_us_min */ our_msat, /* msat_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, ld->config.fee_base, ld->config.fee_per_satoshi, remote_upfront_shutdown_script); /* 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 *msg) { struct funding_channel *fc = channel->peer->uncommitted_channel->fc; struct command *cmd = fc->cmd; /* Massage output into shape so it doesn't kill the JSON serialization */ char *output = tal_strjoin(cmd, tal_strsplit(cmd, msg, "\n", STR_NO_EMPTY), " ", STR_NO_TRAIL); was_pending(command_fail(cmd, FUNDING_BROADCAST_FAIL, "Error broadcasting funding transaction: %s", output)); /* Frees fc too */ tal_free(fc->uc); /* Keep in state CHANNELD_AWAITING_LOCKIN until (manual) broadcast */ } static void funding_success(struct channel *channel) { struct json_stream *response; struct funding_channel *fc = channel->peer->uncommitted_channel->fc; struct command *cmd = fc->cmd; /* Well, those cancels didn't work! */ for (size_t i = 0; i < tal_count(fc->cancels); i++) was_pending(command_fail(fc->cancels[i], LIGHTNINGD, "Funding succeeded before cancel")); response = json_stream_success(cmd); json_add_string(response, "channel_id", type_to_string(tmpctx, struct channel_id, &fc->cid)); json_add_bool(response, "commitments_secured", true); was_pending(command_success(cmd, response)); } static void funding_broadcast_success(struct channel *channel) { struct json_stream *response; struct funding_channel *fc = channel->peer->uncommitted_channel->fc; struct command *cmd = fc->cmd; response = json_stream_success(cmd); json_add_string(response, "tx", fc->hextx); json_add_txid(response, "txid", &channel->funding_txid); json_add_string(response, "channel_id", type_to_string(tmpctx, struct channel_id, &fc->cid)); was_pending(command_success(cmd, response)); /* Frees fc too */ tal_free(fc->uc); } static void funding_broadcast_failed_or_success(struct channel *channel, int exitstatus, const char *msg) { if (exitstatus == 0) { funding_broadcast_success(channel); } else { funding_broadcast_failed(channel, exitstatus, msg); } } static void funding_started_success(struct funding_channel *fc, u8 *scriptPubkey) { struct json_stream *response; struct command *cmd = fc->cmd; char *out; response = json_stream_success(cmd); out = encode_scriptpubkey_to_addr(cmd, get_chainparams(cmd->ld)->bip173_name, scriptPubkey); if (out) json_add_string(response, "funding_address", out); /* Clear this so cancel doesn't think it's still in progress */ fc->cmd = NULL; was_pending(command_success(cmd, response)); } static void opening_funder_start_replied(struct subd *openingd, const u8 *resp, const int *fds, struct funding_channel *fc) { u8 *funding_scriptPubkey; if (!fromwire_opening_funder_start_reply(resp, resp, &funding_scriptPubkey)) { log_broken(fc->uc->log, "bad OPENING_FUNDER_REPLY %s", tal_hex(resp, resp)); was_pending(command_fail(fc->cmd, LIGHTNINGD, "bad OPENING_FUNDER_REPLY %s", tal_hex(fc->cmd, resp))); goto failed; } funding_started_success(fc, funding_scriptPubkey); /* Mark that we're in-flight */ fc->inflight = true; return; failed: subd_release_channel(openingd, fc->uc); fc->uc->openingd = NULL; /* Frees fc too, and tmpctx */ tal_free(fc->uc); } static bool compose_and_broadcast_tx(struct lightningd *ld, const u8 *resp, struct funding_channel *fc, struct channel_info *channel_info, struct channel *channel, struct bitcoin_txid *expected_txid, u32 feerate) { u8 *msg; struct pubkey changekey; u16 funding_outnum; struct bitcoin_tx *fundingtx; struct amount_sat change; struct bitcoin_txid funding_txid; const struct chainparams *chainparams = get_chainparams(ld); /* Generate the funding tx. */ if (!amount_sat_eq(fc->wtx->change, AMOUNT_SAT(0)) && !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, chainparams, &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:", fundingtx->wtx->num_inputs, fundingtx->wtx->num_outputs); for (size_t i = 0; i < fundingtx->wtx->num_inputs; i++) { struct bitcoin_txid tmptxid; bitcoin_tx_input_get_txid(fundingtx, i, &tmptxid); log_debug(fc->uc->log, "%zi: %s (%s) %s\n", i, type_to_string(tmpctx, struct amount_sat, &fc->wtx->utxos[i]->amount), fc->wtx->utxos[i]->is_p2sh ? "P2SH" : "SEGWIT", type_to_string(tmpctx, struct bitcoin_txid, &tmptxid)); } bitcoin_txid(fundingtx, &funding_txid); if (!bitcoin_txid_eq(&funding_txid, expected_txid)) { log_broken(fc->uc->log, "Funding txid mismatch:" " amount %s change %s" " changeidx %u" " localkey %s remotekey %s", type_to_string(tmpctx, struct amount_sat, &fc->wtx->amount), type_to_string(tmpctx, struct amount_sat, &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)); was_pending(command_fail(fc->cmd, JSONRPC2_INVALID_PARAMS, "Funding txid mismatch:" " amount %s change %s" " changeidx %u" " localkey %s remotekey %s", type_to_string(tmpctx, struct amount_sat, &fc->wtx->amount), type_to_string(tmpctx, struct amount_sat, &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))); return false; } /* 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, 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)); fundingtx->chainparams = chainparams; /* Extract the change output and add it to the DB */ wallet_extract_owned_outputs(ld->wallet, fundingtx, NULL, &change); /* 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 (fundingtx->wtx->num_outputs == 2) txfilter_add_scriptpubkey(ld->owned_txfilter, bitcoin_tx_output_get_script(tmpctx, fundingtx, !funding_outnum)); /* Send it out and watch for confirms. */ broadcast_tx(ld->topology, channel, fundingtx, funding_broadcast_failed_or_success); /* Mark consumed outputs as spent */ wallet_confirm_utxos(ld->wallet, fc->wtx->utxos); wallet_transaction_annotate(ld->wallet, &funding_txid, TX_CHANNEL_FUNDING, channel->dbid); /* We need these to compose cmd's response in funding_broadcast_success */ fc->hextx = tal_hex(fc, linearize_tx(fc->cmd, fundingtx)); return true; } static void opening_funder_finished(struct subd *openingd, const u8 *resp, const int *fds, struct funding_channel *fc) { struct channel_info channel_info; struct bitcoin_txid funding_txid; u16 funding_txout; struct bitcoin_signature remote_commit_sig; struct bitcoin_tx *remote_commit; u32 feerate; struct channel *channel; struct lightningd *ld = openingd->ld; u8 *remote_upfront_shutdown_script; struct per_peer_state *pps; /* 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, &pps, &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, &funding_txid, &funding_txout, &feerate, &fc->uc->our_config.channel_reserve, &remote_upfront_shutdown_script)) { log_broken(fc->uc->log, "bad OPENING_FUNDER_REPLY %s", tal_hex(resp, resp)); was_pending(command_fail(fc->cmd, LIGHTNINGD, "bad OPENING_FUNDER_REPLY %s", tal_hex(fc->cmd, resp))); goto cleanup; } remote_commit->chainparams = get_chainparams(openingd->ld); per_peer_state_set_fds_arr(pps, fds); log_debug(ld->log, "%s", type_to_string(tmpctx, struct pubkey, &channel_info.remote_per_commit)); /* Steals fields from uc */ channel = wallet_commit_channel(ld, fc->uc, remote_commit, &remote_commit_sig, &funding_txid, funding_txout, fc->funding, fc->push, fc->channel_flags, &channel_info, feerate, remote_upfront_shutdown_script); if (!channel) { was_pending(command_fail(fc->cmd, LIGHTNINGD, "Key generation failure")); goto cleanup; } /* Watch for funding confirms */ channel_watch_funding(ld, channel); /* Needed for the success statement */ derive_channel_id(&fc->cid, &channel->funding_txid, funding_txout); /* Was this an external wallet initiation ? */ if (fc->inflight) { funding_success(channel); peer_start_channeld(channel, pps, NULL, false); goto cleanup; } if (!compose_and_broadcast_tx(ld, resp, fc, &channel_info, channel, &funding_txid, feerate)) goto cleanup; /* Start normal channel daemon. */ peer_start_channeld(channel, pps, NULL, false); subd_release_channel(openingd, fc->uc); fc->uc->openingd = NULL; return; cleanup: 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 bitcoin_signature remote_commit_sig; struct bitcoin_tx *remote_commit; struct lightningd *ld = openingd->ld; struct bitcoin_txid funding_txid; u16 funding_outnum; struct amount_sat funding; struct amount_msat push; u32 feerate; u8 channel_flags; struct channel *channel; u8 *remote_upfront_shutdown_script; struct per_peer_state *pps; log_debug(uc->log, "Got opening_fundee_finish_response"); /* 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, &pps, &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, &push, &channel_flags, &feerate, &funding_signed, &uc->our_config.channel_reserve, &remote_upfront_shutdown_script)) { log_broken(uc->log, "bad OPENING_FUNDEE_REPLY %s", tal_hex(reply, reply)); uncommitted_channel_disconnect(uc, "bad OPENING_FUNDEE_REPLY"); goto failed; } remote_commit->chainparams = get_chainparams(openingd->ld); per_peer_state_set_fds_arr(pps, fds); /* 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, push, channel_flags, &channel_info, feerate, remote_upfront_shutdown_script); 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); /* Tell plugins about the success */ notify_channel_opened(ld, &channel->peer->id, &channel->funding, &channel->funding_txid, &channel->remote_funding_locked); /* On to normal operation! */ peer_start_channeld(channel, pps, funding_signed, false); subd_release_channel(openingd, uc); uc->openingd = NULL; tal_free(uc); return; failed: close(fds[0]); close(fds[1]); close(fds[3]); 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)); was_pending(command_fail(uc->fc->cmd, LIGHTNINGD, "bad OPENING_FUNDER_FAILED %s", tal_hex(uc->fc->cmd, msg))); tal_free(uc); return; } /* Tell anyone who was trying to cancel */ for (size_t i = 0; i < tal_count(uc->fc->cancels); i++) { struct json_stream *response; response = json_stream_success(uc->fc->cancels[i]); json_add_string(response, "cancelled", desc); was_pending(command_success(uc->fc->cancels[i], response)); } /* Tell any fundchannel_complete or fundchannel command */ if (uc->fc->cmd) was_pending(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, struct per_peer_state *pps, const struct channel_id *channel_id UNUSED, const char *desc, bool soft_error UNUSED, const u8 *err_for_them UNUSED) { /* Close fds, if any. */ tal_free(pps); 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); const 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 node_id, &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, struct amount_msat *min_effective_htlc_capacity) { struct amount_msat dust_limit; /* FIXME: depend on feerate. */ *max_to_self_delay = ld->config.locktime_max; /* Take minimal effective capacity from config min_capacity_sat */ if (!amount_msat_from_sat_u64(min_effective_htlc_capacity, ld->config.min_capacity_sat)) fatal("amount_msat overflow for config.min_capacity_sat"); /* Substract 2 * dust_limit, so fundchannel with min value is possible */ if (!amount_sat_to_msat(&dust_limit, get_chainparams(ld)->dust_limit)) fatal("amount_msat overflow for dustlimit"); if (!amount_msat_sub(min_effective_htlc_capacity, *min_effective_htlc_capacity, dust_limit)) *min_effective_htlc_capacity = AMOUNT_MSAT(0); if (!amount_msat_sub(min_effective_htlc_capacity, *min_effective_htlc_capacity, dust_limit)) *min_effective_htlc_capacity = AMOUNT_MSAT(0); /* 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 = get_chainparams(ld)->dust_limit; ours->max_htlc_value_in_flight = AMOUNT_MSAT(UINT64_MAX); /* Don't care */ ours->htlc_minimum = AMOUNT_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; ours->max_accepted_htlcs = ld->config.max_concurrent_htlcs; /* This is filled in by lightning_openingd, for consistency. */ ours->channel_reserve = AMOUNT_SAT(UINT64_MAX); } struct openchannel_hook_payload { struct subd *openingd; struct amount_sat funding_satoshis; struct amount_msat push_msat; struct amount_sat dust_limit_satoshis; struct amount_msat max_htlc_value_in_flight_msat; struct amount_sat channel_reserve_satoshis; struct amount_msat htlc_minimum_msat; u32 feerate_per_kw; u16 to_self_delay; u16 max_accepted_htlcs; u8 channel_flags; u8 *shutdown_scriptpubkey; }; static void openchannel_hook_serialize(struct openchannel_hook_payload *payload, struct json_stream *stream) { struct uncommitted_channel *uc = payload->openingd->channel; json_object_start(stream, "openchannel"); json_add_node_id(stream, "id", &uc->peer->id); json_add_amount_sat_only(stream, "funding_satoshis", payload->funding_satoshis); json_add_amount_msat_only(stream, "push_msat", payload->push_msat); json_add_amount_sat_only(stream, "dust_limit_satoshis", payload->dust_limit_satoshis); json_add_amount_msat_only(stream, "max_htlc_value_in_flight_msat", payload->max_htlc_value_in_flight_msat); json_add_amount_sat_only(stream, "channel_reserve_satoshis", payload->channel_reserve_satoshis); json_add_amount_msat_only(stream, "htlc_minimum_msat", payload->htlc_minimum_msat); json_add_num(stream, "feerate_per_kw", payload->feerate_per_kw); json_add_num(stream, "to_self_delay", payload->to_self_delay); json_add_num(stream, "max_accepted_htlcs", payload->max_accepted_htlcs); json_add_num(stream, "channel_flags", payload->channel_flags); if (tal_count(payload->shutdown_scriptpubkey) != 0) json_add_hex_talarr(stream, "shutdown_scriptpubkey", payload->shutdown_scriptpubkey); json_object_end(stream); /* .openchannel */ } /* openingd dies? Remove openingd ptr from payload */ static void openchannel_payload_remove_openingd(struct subd *openingd, struct openchannel_hook_payload *payload) { assert(payload->openingd == openingd); payload->openingd = NULL; } static void openchannel_hook_cb(struct openchannel_hook_payload *payload, const char *buffer, const jsmntok_t *toks) { struct subd *openingd = payload->openingd; const char *errmsg = NULL; /* We want to free this, whatever happens. */ tal_steal(tmpctx, payload); /* If openingd went away, don't send it anything! */ if (!openingd) return; tal_del_destructor2(openingd, openchannel_payload_remove_openingd, payload); /* If we had a hook, check what it says */ if (buffer) { const jsmntok_t *t = json_get_member(buffer, toks, "result"); if (!t) fatal("Plugin returned an invalid response to the" " openchannel hook: %.*s", toks[0].end - toks[0].start, buffer + toks[0].start); if (json_tok_streq(buffer, t, "reject")) { t = json_get_member(buffer, toks, "error_message"); if (t) errmsg = json_strdup(tmpctx, buffer, t); else errmsg = ""; log_debug(openingd->ld->log, "openchannel_hook_cb says '%s'", errmsg); } else if (!json_tok_streq(buffer, t, "continue")) fatal("Plugin returned an invalid result for the " "openchannel hook: %.*s", t->end - t->start, buffer + t->start); } subd_send_msg(openingd, take(towire_opening_got_offer_reply(NULL, errmsg))); } REGISTER_PLUGIN_HOOK(openchannel, openchannel_hook_cb, struct openchannel_hook_payload *, openchannel_hook_serialize, struct openchannel_hook_payload *); static void opening_got_offer(struct subd *openingd, const u8 *msg, struct uncommitted_channel *uc) { struct openchannel_hook_payload *payload; /* Tell them they can't open, if we already have open channel. */ if (peer_active_channel(uc->peer)) { subd_send_msg(openingd, take(towire_opening_got_offer_reply(NULL, "Already have active channel"))); return; } payload = tal(openingd->ld, struct openchannel_hook_payload); payload->openingd = openingd; if (!fromwire_opening_got_offer(payload, msg, &payload->funding_satoshis, &payload->push_msat, &payload->dust_limit_satoshis, &payload->max_htlc_value_in_flight_msat, &payload->channel_reserve_satoshis, &payload->htlc_minimum_msat, &payload->feerate_per_kw, &payload->to_self_delay, &payload->max_accepted_htlcs, &payload->channel_flags, &payload->shutdown_scriptpubkey)) { log_broken(openingd->log, "Malformed opening_got_offer %s", tal_hex(tmpctx, msg)); tal_free(openingd); return; } tal_add_destructor2(openingd, openchannel_payload_remove_openingd, payload); plugin_hook_call_openchannel(openingd->ld, payload, payload); } 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) != 3) return 3; opening_funder_finished(openingd, msg, fds, uc->fc); return 0; case WIRE_OPENING_FUNDER_START_REPLY: if (!uc->fc) { log_broken(openingd->log, "Unexpected FUNDER_START_REPLY %s", tal_hex(tmpctx, msg)); tal_free(openingd); return 0; } opening_funder_start_replied(openingd, msg, fds, uc->fc); return 0; case WIRE_OPENING_FUNDER_FAILED: if (!uc->fc) { log_unusual(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) != 3) return 3; opening_fundee_finished(openingd, msg, fds, uc); return 0; case WIRE_OPENING_GOT_OFFER: opening_got_offer(openingd, msg, uc); return 0; /* We send these! */ case WIRE_OPENING_INIT: case WIRE_OPENING_FUNDER: case WIRE_OPENING_FUNDER_START: case WIRE_OPENING_FUNDER_COMPLETE: case WIRE_OPENING_FUNDER_CANCEL: case WIRE_OPENING_GOT_OFFER_REPLY: case WIRE_OPENING_DEV_MEMLEAK: /* Replies never get here */ case WIRE_OPENING_DEV_MEMLEAK_REPLY: 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, struct per_peer_state *pps, const u8 *send_msg) { int hsmfd; u32 max_to_self_delay; struct amount_msat min_effective_htlc_capacity; 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(&pps->peer_fd), take(&pps->gossip_fd), take(&pps->gossip_store_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); /* 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)->genesis_blockhash, &uc->our_config, max_to_self_delay, min_effective_htlc_capacity, pps, &uc->local_basepoints, &uc->local_funding_pubkey, uc->minimum_depth, feerate_min(peer->ld, NULL), feerate_max(peer->ld, NULL), peer->localfeatures, send_msg); subd_send_msg(uc->openingd, take(msg)); } static struct command_result *json_fund_channel_complete(struct command *cmd, const char *buffer, const jsmntok_t *obj UNNEEDED, const jsmntok_t *params) { u8 *msg; struct node_id *id; struct bitcoin_txid *funding_txid; struct peer *peer; struct channel *channel; u32 *funding_txout_num; u16 funding_txout; if (!param(cmd, buffer, params, p_req("id", param_node_id, &id), p_req("txid", param_txid, &funding_txid), p_req("txout", param_number, &funding_txout_num), NULL)) return command_param_failed(); if (*funding_txout_num > UINT16_MAX) return command_fail(cmd, LIGHTNINGD, "Invalid parameter: funding tx vout too large %u", *funding_txout_num); funding_txout = *funding_txout_num; peer = peer_by_id(cmd->ld, id); if (!peer) { return command_fail(cmd, LIGHTNINGD, "Unknown peer"); } channel = peer_active_channel(peer); if (channel) return command_fail(cmd, LIGHTNINGD, "Peer already %s", channel_state_name(channel)); if (!peer->uncommitted_channel) return command_fail(cmd, LIGHTNINGD, "Peer not connected"); if (!peer->uncommitted_channel->fc || !peer->uncommitted_channel->fc->inflight) return command_fail(cmd, LIGHTNINGD, "No channel funding in progress."); if (peer->uncommitted_channel->fc->cmd) return command_fail(cmd, LIGHTNINGD, "Channel funding in progress."); /* Set the cmd to this new cmd */ peer->uncommitted_channel->fc->cmd = cmd; msg = towire_opening_funder_complete(NULL, funding_txid, funding_txout); subd_send_msg(peer->uncommitted_channel->openingd, take(msg)); return command_still_pending(cmd); } /** * json_fund_channel_cancel - Entrypoint for cancelling an in flight channel-funding */ static struct command_result *json_fund_channel_cancel(struct command *cmd, const char *buffer, const jsmntok_t *obj UNNEEDED, const jsmntok_t *params) { struct node_id *id; struct peer *peer; u8 *msg; if (!param(cmd, buffer, params, p_req("id", param_node_id, &id), NULL)) return command_param_failed(); peer = peer_by_id(cmd->ld, id); if (!peer) { return command_fail(cmd, LIGHTNINGD, "Unknown peer"); } if (!peer->uncommitted_channel) { return command_fail(cmd, LIGHTNINGD, "Peer not connected"); } if (!peer->uncommitted_channel->fc || !peer->uncommitted_channel->fc->inflight) return command_fail(cmd, LIGHTNINGD, "No channel funding in progress."); /** * there's a question of 'state machinery' here. as is, we're not checking * to see if you've already called `complete` -- we expect you * the caller to EITHER pick 'complete' or 'cancel'. * but if for some reason you've decided to test your luck, how much * 'handling' can we do for that case? the easiest thing to do is to * say "sorry you've already called complete", we can't cancel this. * * there's also the state you might end up in where you've called * complete (and it's completed and been passed off to channeld) but * you've decided (for whatever reason) not to broadcast the transaction * so your channels have ended up in this 'waiting' state. neither of us * are actually out any amount of cash, but it'd be nice if there's a way * to signal to c-lightning (+ your peer) that this channel is dead on arrival. * ... but also if you then broadcast this tx you'd be in trouble cuz we're * both going to forget about it. the meta question here is how 'undoable' * should we make any of this. how much tools do we give you, reader? * * for now, let's settle for the EITHER / OR case and disregard the larger * question about 'how long cancelable'. */ /* Make sure this gets notified if we succeed or cancel */ tal_arr_expand(&peer->uncommitted_channel->fc->cancels, cmd); msg = towire_opening_funder_cancel(NULL); subd_send_msg(peer->uncommitted_channel->openingd, take(msg)); return command_still_pending(cmd); } /** * json_fund_channel_start - Entrypoint for funding an externally funded channel */ static struct command_result *json_fund_channel_start(struct command *cmd, const char *buffer, const jsmntok_t *obj UNNEEDED, const jsmntok_t *params) { struct funding_channel * fc = tal(cmd, struct funding_channel); struct node_id *id; struct peer *peer; struct channel *channel; bool *announce_channel; u32 *feerate_per_kw; u8 *msg = NULL; struct amount_sat max_funding_satoshi, *amount; max_funding_satoshi = get_chainparams(cmd->ld)->max_funding; fc->cmd = cmd; fc->cancels = tal_arr(fc, struct command *, 0); fc->uc = NULL; fc->inflight = false; if (!param(fc->cmd, buffer, params, p_req("id", param_node_id, &id), p_req("satoshi", param_sat, &amount), p_opt("feerate", param_feerate, &feerate_per_kw), p_opt_def("announce", param_bool, &announce_channel, true), NULL)) return command_param_failed(); if (amount_sat_greater(*amount, max_funding_satoshi)) return command_fail(cmd, FUND_MAX_EXCEEDED, "Amount exceeded %s", type_to_string(tmpctx, struct amount_sat, &max_funding_satoshi)); fc->funding = *amount; if (!feerate_per_kw) { feerate_per_kw = tal(cmd, u32); *feerate_per_kw = opening_feerate(cmd->ld->topology); if (!*feerate_per_kw) { return command_fail(cmd, LIGHTNINGD, "Cannot estimate fees"); } } if (*feerate_per_kw < feerate_floor()) { return command_fail(cmd, LIGHTNINGD, "Feerate below feerate floor"); } if (!topology_synced(cmd->ld->topology)) { return command_fail(cmd, FUNDING_STILL_SYNCING_BITCOIN, "Still syncing with bitcoin network"); } peer = peer_by_id(cmd->ld, id); if (!peer) { return command_fail(cmd, LIGHTNINGD, "Unknown peer"); } channel = peer_active_channel(peer); if (channel) { return command_fail(cmd, LIGHTNINGD, "Peer already %s", channel_state_name(channel)); } if (!peer->uncommitted_channel) { return command_fail(cmd, LIGHTNINGD, "Peer not connected"); } if (peer->uncommitted_channel->fc) { return command_fail(cmd, LIGHTNINGD, "Already funding channel"); } fc->push = AMOUNT_MSAT(0); fc->channel_flags = OUR_CHANNEL_FLAGS; if (!*announce_channel) { fc->channel_flags &= ~CHANNEL_FLAGS_ANNOUNCE_CHANNEL; log_info(peer->ld->log, "Will open private channel with node %s", type_to_string(fc, struct node_id, id)); } assert(!amount_sat_greater(*amount, max_funding_satoshi)); peer->uncommitted_channel->fc = tal_steal(peer->uncommitted_channel, fc); fc->uc = peer->uncommitted_channel; msg = towire_opening_funder_start(NULL, *amount, fc->push, *feerate_per_kw, fc->channel_flags); subd_send_msg(peer->uncommitted_channel->openingd, take(msg)); return command_still_pending(cmd); } /** * json_fund_channel - Entrypoint for funding a channel */ static struct command_result *json_fund_channel(struct command *cmd, const char *buffer, const jsmntok_t *obj UNNEEDED, const jsmntok_t *params) { struct command_result *res; struct funding_channel * fc = tal(cmd, struct funding_channel); struct node_id *id; struct peer *peer; struct channel *channel; u32 *feerate_per_kw, *minconf, maxheight; bool *announce_channel; u8 *msg; struct amount_sat max_funding_satoshi; const struct utxo **chosen_utxos; max_funding_satoshi = get_chainparams(cmd->ld)->max_funding; fc->cmd = cmd; fc->cancels = tal_arr(fc, struct command *, 0); fc->uc = NULL; fc->inflight = false; fc->wtx = tal(fc, struct wallet_tx); wtx_init(cmd, fc->wtx, max_funding_satoshi); if (!param(fc->cmd, buffer, params, p_req("id", param_node_id, &id), p_req("satoshi", param_wtx, fc->wtx), p_opt("feerate", param_feerate, &feerate_per_kw), p_opt_def("announce", param_bool, &announce_channel, true), p_opt_def("minconf", param_number, &minconf, 1), p_opt("utxos", param_utxos, &chosen_utxos), NULL)) return command_param_failed(); if (!feerate_per_kw) { feerate_per_kw = tal(cmd, u32); *feerate_per_kw = opening_feerate(cmd->ld->topology); if (!*feerate_per_kw) { return command_fail(cmd, LIGHTNINGD, "Cannot estimate fees"); } } if (*feerate_per_kw < feerate_floor()) { return command_fail(cmd, LIGHTNINGD, "Feerate below feerate floor"); } if (!topology_synced(cmd->ld->topology)) { return command_fail(cmd, FUNDING_STILL_SYNCING_BITCOIN, "Still syncing with bitcoin network"); } peer = peer_by_id(cmd->ld, id); if (!peer) { return command_fail(cmd, LIGHTNINGD, "Unknown peer"); } channel = peer_active_channel(peer); if (channel) { return command_fail(cmd, LIGHTNINGD, "Peer already %s", channel_state_name(channel)); } if (!peer->uncommitted_channel) { return command_fail(cmd, LIGHTNINGD, "Peer not connected"); } if (peer->uncommitted_channel->fc) { return command_fail(cmd, LIGHTNINGD, "Already funding channel"); } /* FIXME: Support push_msat? */ fc->push = AMOUNT_MSAT(0); fc->channel_flags = OUR_CHANNEL_FLAGS; if (!*announce_channel) { fc->channel_flags &= ~CHANNEL_FLAGS_ANNOUNCE_CHANNEL; log_info(peer->ld->log, "Will open private channel with node %s", type_to_string(fc, struct node_id, id)); } maxheight = minconf_to_maxheight(*minconf, cmd->ld); if (chosen_utxos) res = wtx_from_utxos(fc->wtx, *feerate_per_kw, BITCOIN_SCRIPTPUBKEY_P2WSH_LEN, maxheight, chosen_utxos); else res = wtx_select_utxos(fc->wtx, *feerate_per_kw, BITCOIN_SCRIPTPUBKEY_P2WSH_LEN, maxheight); if (res) return res; assert(!amount_sat_greater(fc->wtx->amount, max_funding_satoshi)); /* Stash total amount in fc as well, as externally funded * channels don't have a wtx */ fc->funding = fc->wtx->amount; 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, *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)); return command_still_pending(cmd); } static const struct json_command fund_channel_command = { "fundchannel", "channels", json_fund_channel, "Fund channel with {id} using {satoshi} (or 'all') satoshis, at optional " "{feerate}. Only use outputs that have {minconf} confirmations." }; AUTODATA(json_command, &fund_channel_command); static const struct json_command fund_channel_start_command = { "fundchannel_start", "channels", json_fund_channel_start, "Start fund channel with {id} using {amount} satoshis. " "Returns a bech32 address to use as an output for a funding transaction." }; AUTODATA(json_command, &fund_channel_start_command); static const struct json_command fund_channel_cancel_command = { "fundchannel_cancel", "channels", json_fund_channel_cancel, "Cancel inflight channel establishment with peer {id}." }; AUTODATA(json_command, &fund_channel_cancel_command); static const struct json_command fund_channel_complete_command = { "fundchannel_complete", "channels", json_fund_channel_complete, "Complete channel establishment with peer {id} for funding transaction" "with {txid}. Returns true on success, false otherwise." }; AUTODATA(json_command, &fund_channel_complete_command); #if DEVELOPER /* Indented to avoid include ordering check */ #include static void opening_died_forget_memleak(struct subd *openingd, struct command *cmd) { /* FIXME: We ignore the remaining openingds in this case. */ opening_memleak_done(cmd, NULL); } /* Mutual recursion */ static void opening_memleak_req_next(struct command *cmd, struct peer *prev); static void opening_memleak_req_done(struct subd *openingd, const u8 *msg, const int *fds UNUSED, struct command *cmd) { bool found_leak; struct uncommitted_channel *uc = openingd->channel; tal_del_destructor2(openingd, opening_died_forget_memleak, cmd); if (!fromwire_opening_dev_memleak_reply(msg, &found_leak)) { was_pending(command_fail(cmd, LIGHTNINGD, "Bad opening_dev_memleak")); return; } if (found_leak) { opening_memleak_done(cmd, openingd); return; } opening_memleak_req_next(cmd, uc->peer); } static void opening_memleak_req_next(struct command *cmd, struct peer *prev) { struct peer *p; list_for_each(&cmd->ld->peers, p, list) { if (!p->uncommitted_channel) continue; if (p == prev) { prev = NULL; continue; } if (prev != NULL) continue; subd_req(p, p->uncommitted_channel->openingd, take(towire_opening_dev_memleak(NULL)), -1, 0, opening_memleak_req_done, cmd); /* Just in case it dies before replying! */ tal_add_destructor2(p->uncommitted_channel->openingd, opening_died_forget_memleak, cmd); return; } opening_memleak_done(cmd, NULL); } void opening_dev_memleak(struct command *cmd) { opening_memleak_req_next(cmd, NULL); } #endif /* DEVELOPER */