/* This is the lightningd handler for messages to/from various * dualopend subdaemons. It manages the callbacks and database * saves and funding tx watching for a channel open */ #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 struct commit_rcvd { struct channel *channel; struct channel_id cid; struct per_peer_state *pps; u8 *commitment_msg; struct uncommitted_channel *uc; }; static void handle_signed_psbt(struct lightningd *ld, const struct wally_psbt *psbt, struct commit_rcvd *rcvd) { /* Now that we've got the signed PSBT, save it */ rcvd->channel->psbt = tal_steal(rcvd->channel, cast_const(struct wally_psbt *, psbt)); wallet_channel_save(ld->wallet, rcvd->channel); channel_watch_funding(ld, rcvd->channel); peer_start_channeld(rcvd->channel, rcvd->pps, rcvd->commitment_msg, psbt, false); } /* ~Map of the Territory~ * * openchannel hook - reserveinputs feerate [{"amt": amt, "script": ""}] excludecommon=true -> psbt -> psbt_set * * openchannel_changed hook - psbt --> most recent -> psbt_set (if same as orig) | complete flag * * openchannel_sign hook - signpsbt psbt -> partially_signed_psbt -> partially_signed_psbt */ struct openchannel2_payload { struct subd *dualopend; struct node_id peer_id; struct amount_sat their_funding; struct amount_sat dust_limit_satoshis; struct amount_msat max_htlc_value_in_flight_msat; struct amount_msat htlc_minimum_msat; u32 funding_feerate_max; u32 funding_feerate_min; u32 funding_feerate_best; u32 feerate_our_max; u32 feerate_our_min; u32 commitment_feerate_per_kw; u16 to_self_delay; u16 max_accepted_htlcs; u8 channel_flags; u32 locktime; u8 *shutdown_scriptpubkey; /* FIXME: include the podle? */ struct amount_sat accepter_funding; u32 funding_feerate_per_kw; struct wally_psbt *psbt; const u8 *our_shutdown_scriptpubkey; }; static void openchannel2_hook_serialize(struct openchannel2_payload *payload, struct json_stream *stream) { json_object_start(stream, "openchannel2"); json_add_node_id(stream, "id", &payload->peer_id); json_add_amount_sat_only(stream, "their_funding", payload->their_funding); 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_msat_only(stream, "htlc_minimum_msat", payload->htlc_minimum_msat); json_add_num(stream, "funding_feerate_max", payload->funding_feerate_max); json_add_num(stream, "funding_feerate_min", payload->funding_feerate_min); json_add_num(stream, "funding_feerate_best", payload->funding_feerate_best); json_add_num(stream, "feerate_our_max", payload->feerate_our_max); json_add_num(stream, "feerate_our_min", payload->feerate_our_min); json_add_num(stream, "commitment_feerate_per_kw", payload->commitment_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); json_add_num(stream, "locktime", payload->locktime); if (tal_bytelen(payload->shutdown_scriptpubkey) != 0) json_add_hex_talarr(stream, "shutdown_scriptpubkey", payload->shutdown_scriptpubkey); /* FIXME: include the podle? */ json_object_end(stream); } struct openchannel2_psbt_payload { struct subd *dualopend; struct wally_psbt *psbt; struct commit_rcvd *rcvd; struct lightningd *ld; }; static void openchannel2_changed_hook_serialize(struct openchannel2_psbt_payload *payload, struct json_stream *stream) { json_object_start(stream, "openchannel2_changed"); json_add_psbt(stream, "psbt", payload->psbt); json_add_string(stream, "channel_id", type_to_string(tmpctx, struct channel_id, &payload->rcvd->cid)); json_object_end(stream); } static void openchannel2_sign_hook_serialize(struct openchannel2_psbt_payload *payload, struct json_stream *stream) { json_object_start(stream, "openchannel2_sign"); json_add_psbt(stream, "psbt", payload->psbt); json_add_string(stream, "channel_id", type_to_string(tmpctx, struct channel_id, &payload->rcvd->channel->cid)); json_object_end(stream); } static const u8 *hook_extract_shutdown_script(struct subd* dualopend, const char *buffer, const jsmntok_t *toks) { const u8 *close_to_script; enum address_parse_result parse_res; if (!buffer) return NULL; const jsmntok_t *t = json_get_member(buffer, toks, "result"); if (!t) fatal("Plugin must return a 'result'" "%.*s", toks[0].end - toks[0].start, buffer + toks[0].start); if (!json_tok_streq(buffer, t, "continue")) { char *errmsg = "Client error. Unable to continue"; subd_send_msg(dualopend, take(towire_dualopend_fail(NULL, errmsg))); return NULL; } const jsmntok_t *close_to_tok = json_get_member(buffer, toks, "close_to"); if (!close_to_tok) return NULL; parse_res = json_to_address_scriptpubkey(tmpctx, chainparams, buffer, close_to_tok, &close_to_script); switch (parse_res) { case ADDRESS_PARSE_UNRECOGNIZED: fatal("Plugin returned an invalid response to the" " openchannel2.close_to hook: %.*s", t->end - t->start, buffer + t->start); case ADDRESS_PARSE_WRONG_NETWORK: fatal("Plugin returned invalid response to the" " openchannel2.close_to hook: address %s is" " not on network %s", tal_hex(NULL, close_to_script), chainparams->network_name); case ADDRESS_PARSE_SUCCESS: return close_to_script; } return NULL; } static bool hook_extract_psbt(const tal_t *ctx, struct subd *dualopend, const char *buffer, const jsmntok_t *toks, char *hook_name, bool allow_empty, struct wally_psbt **out) { struct wally_psbt *returned_psbt; if (!buffer) fatal("Plugin must return a valid response to %s", hook_name); const jsmntok_t *t = json_get_member(buffer, toks, "result"); if (!t) fatal("Plugin must return a 'result' to %s" "%.*s", hook_name, toks[0].end - toks[0].start, buffer + toks[0].start); if (!json_tok_streq(buffer, t, "continue")) { /* dualopend might have closed if we're on the signed round */ if (dualopend) { char *errmsg = "Client error. Unable to continue"; subd_send_msg(dualopend, take(towire_dualopend_fail(NULL, errmsg))); } return false; } const jsmntok_t *psbt_tok = json_get_member(buffer, toks, "psbt"); if (!psbt_tok) { if (!allow_empty) fatal("Plugin must return a 'psbt' to a 'continue'd" "%s %.*s", hook_name, toks[0].end - toks[0].start, buffer + toks[0].start); *out = NULL; return true; } if (!json_to_psbt(ctx, buffer, psbt_tok, &returned_psbt)) fatal("Plugin must return a valid 'psbt' to a 'continue'd" "%s %.*s", hook_name, toks[0].end - toks[0].start, buffer + toks[0].start); *out = returned_psbt; return true; } /* The field is *always* assumed msats, as that's the unit * amount we're transitioning our API over to. A 'xxxsat' * unit will be interpreted correctly, but a value given * without a unit will always be interpreted as msats */ static bool hook_extract_amount(struct subd *dualopend, const char *buffer, const jsmntok_t *toks, char *field_name, struct amount_sat *amount) { struct amount_msat msats; if (!buffer) return false; const jsmntok_t *t = json_get_member(buffer, toks, "result"); if (!t) fatal("Plugin must return a 'result' " " %.*s", toks[0].end - toks[0].start, buffer + toks[0].start); if (!json_tok_streq(buffer, t, "continue")) { char *errmsg = "Client error. Unable to continue"; subd_send_msg(dualopend, take(towire_dualopend_fail(NULL, errmsg))); return false; } /* If there's no amount_sat field, that's ok */ const jsmntok_t *amt_tok = json_get_member(buffer, toks, field_name); if (!amt_tok) { *amount = AMOUNT_SAT(0); return true; } if (!json_to_msat(buffer, amt_tok, &msats)) fatal("Plugin must return a valid '%s' to a 'continue'd" " %.*s", field_name, toks[0].end - toks[0].start, buffer + toks[0].start); *amount = amount_msat_to_sat_round_down(msats); return true; } #define CHECK_CHANGES(set, dir) \ do { \ for (size_t i = 0; i < tal_count(set); i++) { \ ok = psbt_get_serial_id(&set[i].dir.unknowns, &serial_id); \ assert(ok); \ if (serial_id % 2 != opener_side) \ return true; \ } \ } while (false) \ static bool psbt_side_contribs_changed(struct wally_psbt *orig, struct wally_psbt *new, enum side opener_side) { struct psbt_changeset *cs; u64 serial_id; bool ok; cs = psbt_get_changeset(tmpctx, orig, new); if (tal_count(cs->added_ins) == 0 && tal_count(cs->rm_ins) == 0 && tal_count(cs->added_outs) == 0 && tal_count(cs->rm_outs) == 0) return false; /* If there were *any* changes, then the answer to the 'both sides' * question is "yes, there were changes" */ if (opener_side == NUM_SIDES) return true; /* Check that none of the included updates have a serial * id that's the peer's parity */ CHECK_CHANGES(cs->added_ins, input); CHECK_CHANGES(cs->rm_ins, input); CHECK_CHANGES(cs->added_outs, output); CHECK_CHANGES(cs->rm_outs, output); return false; } /* dualopend dies? Remove dualopend ptr from payload */ static void openchannel2_remove_dualopend(struct subd *dualopend, struct openchannel2_payload *payload) { assert(payload->dualopend == dualopend); payload->dualopend = NULL; } static bool openchannel2_hook_deserialize(struct openchannel2_payload *payload, const char *buffer, const jsmntok_t *toks) { struct subd *dualopend = payload->dualopend; /* If our daemon died, we're done */ if (!dualopend) { tal_free(payload); return false; } if (!hook_extract_psbt(payload, dualopend, buffer, toks, "openchannel2", true, &payload->psbt)) return false; payload->our_shutdown_scriptpubkey = hook_extract_shutdown_script(dualopend, buffer, toks); /* Add a serial_id to everything that doesn't have one yet */ if (payload->psbt) psbt_add_serials(payload->psbt, TX_ACCEPTER); if (payload->psbt && !psbt_has_required_fields(payload->psbt)) fatal("Plugin supplied PSBT that's missing required fields. %s", type_to_string(tmpctx, struct wally_psbt, payload->psbt)); if (!hook_extract_amount(dualopend, buffer, toks, "accepter_funding_msat", &payload->accepter_funding)) fatal("Plugin failed to supply accepter_funding_msat field"); const jsmntok_t *t = json_get_member(buffer, toks, "funding_feerate"); /* If they don't return a feerate, we use the best */ if (!t) payload->funding_feerate_per_kw = payload->funding_feerate_best; else { if (!json_to_number(buffer, t, &payload->funding_feerate_per_kw)) fatal("Unable to parse 'funding-feerate'"); if (payload->funding_feerate_per_kw < payload->funding_feerate_min || payload->funding_feerate_per_kw > payload->funding_feerate_max) /* FIXME: return an error instead of failing? */ fatal("Plugin supplied invalid funding feerate %d." " Outside valid range %d - %d", payload->funding_feerate_per_kw, payload->funding_feerate_min, payload->funding_feerate_max); } if (!payload->psbt && !amount_sat_eq(payload->accepter_funding, AMOUNT_SAT(0))) { /* Gotta give a PSBT if you set the accepter_funding amount */ return false; } return true; } static void openchannel2_hook_cb(struct openchannel2_payload *payload STEALS) { struct subd *dualopend = payload->dualopend; u8 *msg; /* Free payload regardless of what happens next */ tal_steal(tmpctx, payload); /* If our daemon died, we're done */ if (!dualopend) return; tal_del_destructor2(dualopend, openchannel2_remove_dualopend, payload); /* If there's no plugin, the funding_feerate_per_kw will be zero. * In this case, we set the funding_feerate_per_kw to the default, * the 'best' */ if (payload->funding_feerate_per_kw == 0) payload->funding_feerate_per_kw = payload->funding_feerate_best; /* If there's no plugin, the psbt will be NULL. We should pass an empty * PSBT over, in this case */ msg = towire_dualopend_got_offer_reply(NULL, payload->accepter_funding, payload->funding_feerate_per_kw, payload->psbt, payload->our_shutdown_scriptpubkey); subd_send_msg(dualopend, take(msg)); } /* dualopend dies? Remove dualopend ptr from payload */ static void openchannel2_psbt_remove_dualopend(struct subd *dualopend, struct openchannel2_psbt_payload *payload) { assert(payload->dualopend == dualopend); payload->dualopend = NULL; } static bool openchannel2_changed_deserialize(struct openchannel2_psbt_payload *payload, const char *buffer, const jsmntok_t *toks) { struct subd *dualopend = payload->dualopend; struct wally_psbt *psbt; if (!hook_extract_psbt(NULL, dualopend, buffer, toks, "openchannel2_sign", false, &psbt)) return false; /* Add serials to PSBT, before checking for required fields */ psbt_add_serials(psbt, TX_ACCEPTER); if (!psbt_has_required_fields(psbt)) fatal("Plugin supplied PSBT that's missing required fields. %s", type_to_string(tmpctx, struct wally_psbt, psbt)); if (payload->psbt) tal_free(payload->psbt); payload->psbt = tal_steal(payload, psbt); return true; } static void openchannel2_changed_hook_cb(struct openchannel2_psbt_payload *payload STEALS) { struct subd *dualopend = payload->dualopend; /* Free payload regardless of what happens next */ tal_steal(tmpctx, payload); /* If our daemon died, we're done */ if (!dualopend) return; tal_del_destructor2(dualopend, openchannel2_psbt_remove_dualopend, payload); subd_send_msg(dualopend, take(towire_dualopend_psbt_updated(NULL, payload->psbt))); } static bool openchannel2_signed_deserialize(struct openchannel2_psbt_payload *payload, const char *buffer, const jsmntok_t *toks) { struct subd *dualopend = payload->dualopend; struct wally_psbt *psbt; if (!hook_extract_psbt(NULL, dualopend, buffer, toks, "openchannel2_sign", false, &psbt)) return false; if (!psbt_has_required_fields(psbt)) fatal("Plugin supplied PSBT that's missing required fields. %s", type_to_string(tmpctx, struct wally_psbt, psbt)); /* Verify that inputs/outputs are the same. Note that this is a * 'de minimus' check -- we just look at serial_ids. If you've * totally managled the data here but left the serial_ids intact, * you'll get a failure back from the peer when you send * commitment sigs */ if (psbt_side_contribs_changed(payload->psbt, psbt, NUM_SIDES)) fatal("Plugin must not change psbt input/output set. " "orig: %s. updated: %s", type_to_string(tmpctx, struct wally_psbt, payload->psbt), type_to_string(tmpctx, struct wally_psbt, psbt)); if (payload->psbt) tal_free(payload->psbt); payload->psbt = tal_steal(payload, psbt); return true; } static void openchannel2_sign_hook_cb(struct openchannel2_psbt_payload *payload STEALS) { /* Free payload regardless of what happens next */ tal_steal(tmpctx, payload); /* Finalize it, if not already. It shouldn't work entirely */ psbt_finalize(payload->psbt); if (!psbt_side_finalized(payload->psbt, TX_ACCEPTER)) fatal("Plugin must return a 'psbt' with signatures " "for their inputs %s", type_to_string(tmpctx, struct wally_psbt, payload->psbt)); handle_signed_psbt(payload->ld, payload->psbt, payload->rcvd); } REGISTER_PLUGIN_HOOK(openchannel2, openchannel2_hook_deserialize, openchannel2_hook_cb, openchannel2_hook_serialize, struct openchannel2_payload *); REGISTER_PLUGIN_HOOK(openchannel2_changed, openchannel2_changed_deserialize, openchannel2_changed_hook_cb, openchannel2_changed_hook_serialize, struct openchannel2_psbt_payload *); REGISTER_PLUGIN_HOOK(openchannel2_sign, openchannel2_signed_deserialize, openchannel2_sign_hook_cb, openchannel2_sign_hook_serialize, struct openchannel2_psbt_payload *); /* 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 channel_id *cid, struct bitcoin_tx *remote_commit, struct bitcoin_signature *remote_commit_sig, const struct bitcoin_txid *funding_txid, u16 funding_outnum, struct amount_sat total_funding, struct amount_sat our_funding, u8 channel_flags, const struct channel_info *channel_info, u32 feerate, enum side opener, const u8 *our_upfront_shutdown_script, const u8 *remote_upfront_shutdown_script) { struct channel *channel; s64 final_key_idx; bool option_static_remotekey; bool option_anchor_outputs; struct amount_msat our_msat; /* 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 (!amount_sat_to_msat(&our_msat, our_funding)) { log_broken(uc->log, "Unable to convert funds"); return NULL; } /* BOLT-7b04b1461739c5036add61782d58ac490842d98b #9 * | 222/223 | `option_dual_fund` * | Use v2 of channel open, enables dual funding * | IN9 * | `option_anchor_outputs` */ option_static_remotekey = true; option_anchor_outputs = true; channel = new_channel(uc->peer, uc->dbid, NULL, /* No shachain yet */ CHANNELD_AWAITING_LOCKIN, opener, uc->log, take(uc->transient_billboard), channel_flags, &uc->our_config, uc->minimum_depth, 1, 1, 0, funding_txid, funding_outnum, total_funding, AMOUNT_MSAT(0), our_funding, false, /* !remote_funding_locked */ NULL, /* no scid yet */ cid, /* 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, take(new_fee_states(NULL, opener, &feerate)), NULL, /* No shutdown_scriptpubkey[REMOTE] yet */ our_upfront_shutdown_script, 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, option_static_remotekey, option_anchor_outputs, NULL, NUM_SIDES, /* closer not yet known */ opener == LOCAL ? REASON_USER : REASON_REMOTE); /* Now we finally put it in the database. */ wallet_channel_insert(ld->wallet, channel); return channel; } static void opener_psbt_changed(struct subd *dualopend, struct uncommitted_channel *uc, const u8 *msg) { struct channel_id cid; u64 funding_serial; struct wally_psbt *psbt; struct json_stream *response; struct command *cmd = uc->fc->cmd; if (!fromwire_dualopend_psbt_changed(cmd, msg, &cid, &funding_serial, &psbt)) { log_broken(dualopend->log, "Malformed dual_open_psbt_changed %s", tal_hex(tmpctx, msg)); tal_free(dualopend); return; } response = json_stream_success(cmd); json_add_string(response, "channel_id", type_to_string(tmpctx, struct channel_id, &cid)); json_add_psbt(response, "psbt", psbt); json_add_bool(response, "commitments_secured", false); json_add_u64(response, "funding_serial", funding_serial); uc->cid = cid; uc->fc->inflight = true; uc->fc->cmd = NULL; was_pending(command_success(cmd, response)); } static void accepter_commit_received(struct subd *dualopend, struct uncommitted_channel *uc, const int *fds, const u8 *msg) { struct openchannel2_psbt_payload *payload; struct lightningd *ld = dualopend->ld; struct channel_info channel_info; struct bitcoin_tx *remote_commit; struct bitcoin_signature remote_commit_sig; struct channel_id cid; struct bitcoin_txid funding_txid; struct per_peer_state *pps; u16 funding_outnum; u32 feerate; struct amount_sat total_funding, funding_ours; u8 channel_flags, *remote_upfront_shutdown_script, *local_upfront_shutdown_script, *commitment_msg; struct penalty_base *pbase; struct wally_psbt *psbt; payload = tal(uc, struct openchannel2_psbt_payload); payload->rcvd = tal(payload, struct commit_rcvd); /* This is a new channel_info.their_config so set its ID to 0 */ channel_info.their_config.id = 0; if (!fromwire_dualopend_commit_rcvd(tmpctx, msg, &channel_info.their_config, &remote_commit, &pbase, &remote_commit_sig, &psbt, &cid, &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, &total_funding, &funding_ours, &channel_flags, &feerate, &commitment_msg, &uc->our_config.channel_reserve, &local_upfront_shutdown_script, &remote_upfront_shutdown_script)) { log_broken(uc->log, "bad WIRE_DUALOPEND_COMMIT_RCVD %s", tal_hex(msg, msg)); uncommitted_channel_disconnect(uc, LOG_BROKEN, "bad WIRE_DUALOPEND_COMMIT_RCVD"); close(fds[0]); close(fds[1]); close(fds[3]); goto failed; } per_peer_state_set_fds_arr(pps, fds); payload->psbt = tal_steal(payload, psbt); payload->rcvd->pps = tal_steal(payload, pps); payload->rcvd->commitment_msg = tal_steal(payload, commitment_msg); payload->ld = ld; if (peer_active_channel(uc->peer)) { uncommitted_channel_disconnect(uc, LOG_BROKEN, "already have active channel"); goto failed; } /* old_remote_per_commit not valid yet, copy valid one. */ channel_info.old_remote_per_commit = channel_info.remote_per_commit; payload->rcvd->channel = wallet_commit_channel(ld, uc, &cid, remote_commit, &remote_commit_sig, &funding_txid, funding_outnum, total_funding, funding_ours, channel_flags, &channel_info, feerate, REMOTE, local_upfront_shutdown_script, remote_upfront_shutdown_script); if (!payload->rcvd->channel) { uncommitted_channel_disconnect(uc, LOG_BROKEN, "commit channel failed"); goto failed; } if (pbase) wallet_penalty_base_add(ld->wallet, payload->rcvd->channel->dbid, pbase); /* dualopend is going away! */ /* We steal onto `NULL` because `payload` is tal'd off of `uc`; * we free `uc` at the end though */ payload->rcvd->uc = tal_steal(NULL, uc); /* We call out to our hook friend who will provide signatures for us! */ plugin_hook_call_openchannel2_sign(ld, payload); /* We release the things here; dualopend is going away ?? */ subd_release_channel(dualopend, uc); uc->open_daemon = NULL; return; failed: subd_release_channel(dualopend, uc); uc->open_daemon = NULL; tal_free(uc); } static void opener_commit_received(struct subd *dualopend, struct uncommitted_channel *uc, const int *fds, const u8 *msg) { struct lightningd *ld = dualopend->ld; struct channel_info channel_info; struct bitcoin_tx *remote_commit; struct bitcoin_signature remote_commit_sig; struct channel_id cid; struct bitcoin_txid funding_txid; struct per_peer_state *pps; struct json_stream *response; u16 funding_outnum; u32 feerate; struct amount_sat total_funding, funding_ours; u8 channel_flags, *remote_upfront_shutdown_script, *local_upfront_shutdown_script, *commitment_msg; struct penalty_base *pbase; struct wally_psbt *psbt; struct channel *channel; char *err_reason; /* This is a new channel_info.their_config so set its ID to 0 */ channel_info.their_config.id = 0; if (!fromwire_dualopend_commit_rcvd(tmpctx, msg, &channel_info.their_config, &remote_commit, &pbase, &remote_commit_sig, &psbt, &cid, &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, &total_funding, &funding_ours, &channel_flags, &feerate, &commitment_msg, &uc->our_config.channel_reserve, &local_upfront_shutdown_script, &remote_upfront_shutdown_script)) { log_broken(uc->log, "bad WIRE_DUALOPEND_COMMIT_RCVD %s", tal_hex(msg, msg)); err_reason = "bad WIRE_DUALOPEND_COMMIT_RCVD"; uncommitted_channel_disconnect(uc, LOG_BROKEN, err_reason); close(fds[0]); close(fds[1]); close(fds[3]); goto failed; } /* We shouldn't have a commitment message, this is an * accepter flow item */ assert(!commitment_msg); /* old_remote_per_commit not valid yet, copy valid one. */ channel_info.old_remote_per_commit = channel_info.remote_per_commit; per_peer_state_set_fds_arr(pps, fds); if (peer_active_channel(uc->peer)) { err_reason = "already have active channel"; uncommitted_channel_disconnect(uc, LOG_BROKEN, err_reason); goto failed; } /* Our end game is to save the channel to the database, and return the * command with 'commitments_secured' set to true */ channel = wallet_commit_channel(ld, uc, &cid, remote_commit, &remote_commit_sig, &funding_txid, funding_outnum, total_funding, funding_ours, channel_flags, &channel_info, feerate, LOCAL, local_upfront_shutdown_script, remote_upfront_shutdown_script); if (!channel) { err_reason = "commit channel failed"; uncommitted_channel_disconnect(uc, LOG_BROKEN, err_reason); goto failed; } if (pbase) wallet_penalty_base_add(ld->wallet, channel->dbid, pbase); response = json_stream_success(uc->fc->cmd); json_add_string(response, "channel_id", type_to_string(tmpctx, struct channel_id, &cid)); json_add_psbt(response, "psbt", psbt); json_add_bool(response, "commitments_secured", true); /* For convenience sake, we include the funding outnum */ json_add_num(response, "funding_outnum", funding_outnum); if (local_upfront_shutdown_script) json_add_hex_talarr(response, "close_to", local_upfront_shutdown_script); /* Now that we've got the final PSBT, save it */ channel->psbt = tal_steal(channel, psbt); wallet_channel_save(uc->fc->cmd->ld->wallet, channel); peer_start_channeld(channel, pps, NULL, psbt, false); was_pending(command_success(uc->fc->cmd, response)); goto cleanup; failed: was_pending(command_fail(uc->fc->cmd, LIGHTNINGD, "%s", err_reason)); cleanup: subd_release_channel(dualopend, uc); uc->open_daemon = NULL; tal_free(uc); } static void accepter_psbt_changed(struct subd *dualopend, const u8 *msg) { u64 unused; struct openchannel2_psbt_payload *payload = tal(dualopend, struct openchannel2_psbt_payload); payload->dualopend = dualopend; payload->psbt = NULL; payload->rcvd = tal(payload, struct commit_rcvd); if (!fromwire_dualopend_psbt_changed(payload, msg, &payload->rcvd->cid, &unused, &payload->psbt)) { log_broken(dualopend->log, "Malformed dual_open_psbt_changed %s", tal_hex(tmpctx, msg)); tal_free(dualopend); return; } tal_add_destructor2(dualopend, openchannel2_psbt_remove_dualopend, payload); plugin_hook_call_openchannel2_changed(dualopend->ld, payload); } static void accepter_got_offer(struct subd *dualopend, struct uncommitted_channel *uc, const u8 *msg) { struct openchannel2_payload *payload; if (peer_active_channel(uc->peer)) { subd_send_msg(dualopend, take(towire_dualopend_fail(NULL, "Already have active channel"))); return; } payload = tal(dualopend, struct openchannel2_payload); payload->dualopend = dualopend; payload->psbt = NULL; payload->accepter_funding = AMOUNT_SAT(0); payload->our_shutdown_scriptpubkey = NULL; payload->peer_id = uc->peer->id; if (!fromwire_dualopend_got_offer(payload, msg, &payload->their_funding, &payload->dust_limit_satoshis, &payload->max_htlc_value_in_flight_msat, &payload->htlc_minimum_msat, &payload->funding_feerate_max, &payload->funding_feerate_min, &payload->funding_feerate_best, &payload->commitment_feerate_per_kw, &payload->to_self_delay, &payload->max_accepted_htlcs, &payload->channel_flags, &payload->locktime, &payload->shutdown_scriptpubkey)) { log_broken(uc->log, "Malformed dual_open_got_offer %s", tal_hex(tmpctx, msg)); tal_free(dualopend); return; } /* As a convenience to the plugin, we provide our current known * min + max feerates. Ideally, the plugin will fail to * contribute funds if the peer's feerate range is outside of * this acceptable range, but we delegate that decision to * the plugin's logic */ payload->feerate_our_min = feerate_min(dualopend->ld, NULL); payload->feerate_our_max = feerate_max(dualopend->ld, NULL); /* Set the inital to feerate to zero, in case there is no plugin */ payload->funding_feerate_per_kw = 0; tal_add_destructor2(dualopend, openchannel2_remove_dualopend, payload); plugin_hook_call_openchannel2(dualopend->ld, payload); } static struct command_result *json_open_channel_update(struct command *cmd, const char *buffer, const jsmntok_t *obj UNNEEDED, const jsmntok_t *params) { struct wally_psbt *psbt; struct channel_id *cid; struct channel *channel; struct uncommitted_channel *uc; u8 *msg; if (!param(cmd, buffer, params, p_req("channel_id", param_channel_id, &cid), p_req("psbt", param_psbt, &psbt), NULL)) return command_param_failed(); /* We expect this to return NULL, as the channel hasn't been * created yet. Instead, the uncommitted channel is populated */ channel = channel_by_cid(cmd->ld, cid, &uc); if (channel) return command_fail(cmd, LIGHTNINGD, "Channel already %s", channel_state_name(channel)); if (!uc) return command_fail(cmd, FUNDING_UNKNOWN_CHANNEL, "Unknown channel %s", type_to_string(tmpctx, struct channel_id, cid)); if (!uc->fc || !uc->fc->inflight) return command_fail(cmd, LIGHTNINGD, "No channel funding in progress"); if (uc->fc->cmd) return command_fail(cmd, LIGHTNINGD, "Channel funding in progress"); /* Add serials to PSBT */ psbt_add_serials(psbt, TX_INITIATOR); if (!psbt_has_required_fields(psbt)) return command_fail(cmd, FUNDING_PSBT_INVALID, "PSBT is missing required fields %s", type_to_string(tmpctx, struct wally_psbt, psbt)); uc->fc->cmd = cmd; msg = towire_dualopend_psbt_updated(NULL, psbt); subd_send_msg(uc->open_daemon, take(msg)); return command_still_pending(cmd); } static struct command_result *json_open_channel_init(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_funding; u32 *feerate_per_kw; struct amount_sat *amount, psbt_val; struct wally_psbt *psbt; u8 *msg = NULL; 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("amount", param_sat, &amount), p_req("initialpsbt", param_psbt, &psbt), p_opt("commitment_feerate", param_feerate, &feerate_per_kw), p_opt("funding_feerate", param_feerate, &feerate_per_kw_funding), p_opt_def("announce", param_bool, &announce_channel, true), p_opt("close_to", param_bitcoin_address, &fc->our_upfront_shutdown_script), NULL)) return command_param_failed(); psbt_val = AMOUNT_SAT(0); for (size_t i = 0; i < psbt->num_inputs; i++) { struct amount_sat in_amt = psbt_input_get_amount(psbt, i); if (!amount_sat_add(&psbt_val, psbt_val, in_amt)) return command_fail(cmd, JSONRPC2_INVALID_PARAMS, "Overflow in adding PSBT input values. %s", type_to_string(tmpctx, struct wally_psbt, psbt)); } /* If they don't pass in at least enough in the PSBT to cover * their amount, nope */ if (!amount_sat_greater(psbt_val, *amount)) return command_fail(cmd, FUND_CANNOT_AFFORD, "Provided PSBT cannot afford funding of " "amount %s. %s", type_to_string(tmpctx, struct amount_sat, amount), type_to_string(tmpctx, struct wally_psbt, psbt)); fc->funding = *amount; if (!feerate_per_kw) { feerate_per_kw = tal(cmd, u32); /* Anchors exist, set the commitment feerate to min */ *feerate_per_kw = feerate_min(cmd->ld, NULL); } if (!feerate_per_kw_funding) { feerate_per_kw_funding = tal(cmd, u32); *feerate_per_kw_funding = opening_feerate(cmd->ld->topology); if (!*feerate_per_kw_funding) return command_fail(cmd, LIGHTNINGD, "`funding_feerate` not specified and fee " "estimation failed"); } 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, FUNDING_UNKNOWN_PEER, "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, FUNDING_PEER_NOT_CONNECTED, "Peer not connected"); } if (peer->uncommitted_channel->fc) { return command_fail(cmd, LIGHTNINGD, "Already funding channel"); } #if EXPERIMENTAL_FEATURES if (!feature_negotiated(cmd->ld->our_features, peer->their_features, OPT_DUAL_FUND)) { return command_fail(cmd, FUNDING_V2_NOT_SUPPORTED, "v2 openchannel not supported " "by peer"); } #endif /* EXPERIMENTAL_FEATURES */ /* BOLT #2: * - if both nodes advertised `option_support_large_channel`: * - MAY set `funding_satoshis` greater than or equal to 2^24 satoshi. * - otherwise: * - MUST set `funding_satoshis` to less than 2^24 satoshi. */ if (!feature_negotiated(cmd->ld->our_features, peer->their_features, OPT_LARGE_CHANNELS) && amount_sat_greater(*amount, chainparams->max_funding)) return command_fail(cmd, FUND_MAX_EXCEEDED, "Amount exceeded %s", type_to_string(tmpctx, struct amount_sat, &chainparams->max_funding)); 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)); } /* Add serials to any input that's missing them */ psbt_add_serials(psbt, TX_INITIATOR); if (!psbt_has_required_fields(psbt)) return command_fail(cmd, FUNDING_PSBT_INVALID, "PSBT is missing required fields %s", type_to_string(tmpctx, struct wally_psbt, psbt)); peer->uncommitted_channel->fc = tal_steal(peer->uncommitted_channel, fc); fc->uc = peer->uncommitted_channel; /* Needs to be stolen away from cmd */ if (fc->our_upfront_shutdown_script) fc->our_upfront_shutdown_script = tal_steal(fc, fc->our_upfront_shutdown_script); msg = towire_dualopend_opener_init(NULL, psbt, *amount, fc->our_upfront_shutdown_script, *feerate_per_kw, *feerate_per_kw_funding, fc->channel_flags); subd_send_msg(peer->uncommitted_channel->open_daemon, take(msg)); return command_still_pending(cmd); } static unsigned int dual_opend_msg(struct subd *dualopend, const u8 *msg, const int *fds) { enum dualopend_wire t = fromwire_peektype(msg); struct uncommitted_channel *uc = dualopend->channel; switch (t) { case WIRE_DUALOPEND_GOT_OFFER: accepter_got_offer(dualopend, uc, msg); return 0; case WIRE_DUALOPEND_PSBT_CHANGED: if (uc->fc) { if (!uc->fc->cmd) { log_unusual(dualopend->log, "Unexpected PSBT_CHANGED %s", tal_hex(tmpctx, msg)); tal_free(dualopend); return 0; } opener_psbt_changed(dualopend, uc, msg); } else accepter_psbt_changed(dualopend, msg); return 0; case WIRE_DUALOPEND_COMMIT_RCVD: if (tal_count(fds) != 3) return 3; if (uc->fc) { if (!uc->fc->cmd) { log_unusual(dualopend->log, "Unexpected COMMIT_RCVD %s", tal_hex(tmpctx, msg)); tal_free(dualopend); return 0; } opener_commit_received(dualopend, uc, fds, msg); } else accepter_commit_received(dualopend, uc, fds, msg); return 0; case WIRE_DUALOPEND_FAILED: case WIRE_DUALOPEND_DEV_MEMLEAK_REPLY: /* Messages we send */ case WIRE_DUALOPEND_INIT: case WIRE_DUALOPEND_OPENER_INIT: case WIRE_DUALOPEND_GOT_OFFER_REPLY: case WIRE_DUALOPEND_FAIL: case WIRE_DUALOPEND_PSBT_UPDATED: case WIRE_DUALOPEND_DEV_MEMLEAK: break; } switch ((enum common_wire)t) { #if DEVELOPER case WIRE_CUSTOMMSG_IN: handle_custommsg_in(dualopend->ld, dualopend->node_id, msg); return 0; #else case WIRE_CUSTOMMSG_IN: #endif /* We send these. */ case WIRE_CUSTOMMSG_OUT: break; } log_broken(dualopend->log, "Unexpected msg %s: %s", dualopend_wire_name(t), tal_hex(tmpctx, msg)); tal_free(dualopend); return 0; } static const struct json_command open_channel_init_command = { "openchannel_init", "channels", json_open_channel_init, "Init an open channel to {id} with {initialpsbt} for {amount} satoshis. " "Returns updated {psbt} with (partial) contributions from peer" }; static const struct json_command open_channel_update_command = { "openchannel_update", "channels", json_open_channel_update, "Update {channel_id} with {psbt}. " "Returns updated {psbt} with (partial) contributions from peer. " "If {commitments_secured} is true, next call should be to openchannel_signed" }; #if EXPERIMENTAL_FEATURES AUTODATA(json_command, &open_channel_init_command); AUTODATA(json_command, &open_channel_update_command); #endif /* EXPERIMENTAL_FEATURES */ void peer_start_dualopend(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->open_daemon = new_channel_subd(peer->ld, "lightning_dualopend", uc, &peer->id, uc->log, true, dualopend_wire_name, dual_opend_msg, opend_channel_errmsg, opend_channel_set_billboard, take(&pps->peer_fd), take(&pps->gossip_fd), take(&pps->gossip_store_fd), take(&hsmfd), NULL); if (!uc->open_daemon) { uncommitted_channel_disconnect(uc, LOG_BROKEN, tal_fmt(tmpctx, "Running lightning_dualopend: %s", strerror(errno))); tal_free(uc); 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_dualopend_init(NULL, chainparams, peer->ld->our_features, peer->their_features, &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), send_msg); subd_send_msg(uc->open_daemon, take(msg)); }