/* This is a plugin which allows you to specify * your policy for accepting/dual-funding incoming * v2 channel-open requests. * */ #include "config.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* In-progress channel opens */ static struct list_head pending_opens; /* Current set policy */ static struct funder_policy *current_policy; struct pending_open { struct list_node list; struct plugin *p; struct node_id peer_id; struct channel_id channel_id; const struct wally_psbt *psbt; }; static struct pending_open * find_channel_pending_open(const struct channel_id *cid) { struct pending_open *open; list_for_each(&pending_opens, open, list) { if (channel_id_eq(&open->channel_id, cid)) return open; } return NULL; } static struct pending_open * new_channel_open(const tal_t *ctx, struct plugin *p, const struct node_id id, const struct channel_id cid, const struct wally_psbt *psbt STEALS) { struct pending_open *open; /* Make sure we haven't gotten this yet */ assert(!find_channel_pending_open(&cid)); open = tal(ctx, struct pending_open); open->p = p; open->peer_id = id; open->channel_id = cid; open->psbt = tal_steal(open, psbt); list_add_tail(&pending_opens, &open->list); return open; } static struct command_result * unreserve_done(struct command *cmd UNUSED, const char *buf, const jsmntok_t *result, struct pending_open *open) { plugin_log(open->p, LOG_DBG, "`unreserveinputs` for channel %s completed. %*.s", type_to_string(tmpctx, struct channel_id, &open->channel_id), json_tok_full_len(result), json_tok_full(buf, result)); tal_free(open); return command_done(); } /* Frees open (eventually, in unreserve_done callback) */ static void unreserve_psbt(struct pending_open *open) { struct out_req *req; plugin_log(open->p, LOG_DBG, "Calling `unreserveinputs` for channel %s", type_to_string(tmpctx, struct channel_id, &open->channel_id)); req = jsonrpc_request_start(open->p, NULL, "unreserveinputs", unreserve_done, unreserve_done, open); json_add_psbt(req->js, "psbt", open->psbt); send_outreq(open->p, req); /* We will free this in callback, but remove from list *now* * to avoid calling twice! */ list_del_from(&pending_opens, &open->list); notleak(open); } static void cleanup_peer_pending_opens(const struct node_id *id) { struct pending_open *i, *next; list_for_each_safe(&pending_opens, i, next, list) { if (node_id_eq(&i->peer_id, id)) { unreserve_psbt(i); } } } static struct command_result * command_hook_cont_psbt(struct command *cmd, struct wally_psbt *psbt) { struct json_stream *response; response = jsonrpc_stream_success(cmd); json_add_string(response, "result", "continue"); json_add_psbt(response, "psbt", psbt); return command_finished(cmd, response); } static struct command_result * datastore_del_fail(struct command *cmd, const char *buf, const jsmntok_t *error, void *data UNUSED) { /* Eh, ok fine */ return notification_handled(cmd); } static struct command_result * datastore_del_success(struct command *cmd, const char *buf, const jsmntok_t *result, void *data UNUSED) { /* Cool we deleted some stuff */ plugin_log(cmd->plugin, LOG_DBG, "`datastore` del succeeded: %*.s", json_tok_full_len(result), json_tok_full(buf, result)); return notification_handled(cmd); } static struct command_result * datastore_add_fail(struct command *cmd, const char *buf, const jsmntok_t *error, struct wally_psbt *signed_psbt) { /* Oops, something's broken */ plugin_log(cmd->plugin, LOG_BROKEN, "`datastore` add failed: %*.s", json_tok_full_len(error), json_tok_full(buf, error)); return command_hook_cont_psbt(cmd, signed_psbt); } static struct command_result * datastore_add_success(struct command *cmd, const char *buf, const jsmntok_t *result, struct wally_psbt *signed_psbt) { const char *key, *err; err = json_scan(tmpctx, buf, result, "{key:%}", JSON_SCAN_TAL(cmd, json_strdup, &key)); if (err) plugin_err(cmd->plugin, "`datastore` payload did not scan. %s: %*.s", err, json_tok_full_len(result), json_tok_full(buf, result)); /* We saved the infos! */ plugin_log(cmd->plugin, LOG_DBG, "Saved utxos for channel (%s) to datastore", key); return command_hook_cont_psbt(cmd, signed_psbt); } static struct command_result * remember_channel_utxos(struct command *cmd, struct pending_open *open, struct wally_psbt *signed_psbt) { struct out_req *req; u8 *utxos_bin; char *chan_key = tal_fmt(cmd, "funder/%s", type_to_string(cmd, struct channel_id, &open->channel_id)); req = jsonrpc_request_start(cmd->plugin, cmd, "datastore", &datastore_add_success, &datastore_add_fail, signed_psbt); utxos_bin = tal_arr(cmd, u8, 0); for (size_t i = 0; i < signed_psbt->num_inputs; i++) { struct bitcoin_outpoint outpoint; /* Don't save peer's UTXOS */ if (!psbt_input_is_ours(&signed_psbt->inputs[i])) continue; wally_psbt_input_get_outpoint(&signed_psbt->inputs[i], &outpoint); towire_bitcoin_outpoint(&utxos_bin, &outpoint); } json_add_string(req->js, "key", chan_key); /* We either update the existing or add a new one, nbd */ json_add_string(req->js, "mode", "create-or-replace"); json_add_hex(req->js, "hex", utxos_bin, tal_bytelen(utxos_bin)); return send_outreq(cmd->plugin, req); } static struct command_result * signpsbt_done(struct command *cmd, const char *buf, const jsmntok_t *result, struct pending_open *open) { struct wally_psbt *signed_psbt; struct command_result *res; const char *err; plugin_log(cmd->plugin, LOG_DBG, "`signpsbt` done for channel %s", type_to_string(tmpctx, struct channel_id, &open->channel_id)); err = json_scan(tmpctx, buf, result, "{signed_psbt:%}", JSON_SCAN_TAL(cmd, json_to_psbt, &signed_psbt)); if (err) plugin_err(cmd->plugin, "`signpsbt` payload did not scan %s: %*.s", err, json_tok_full_len(result), json_tok_full(buf, result)); /* Save the list of utxos to the datastore! We'll need * them again if we rbf */ res = remember_channel_utxos(cmd, open, signed_psbt); /* The in-flight open is done, let's clean it up! */ list_del_from(&pending_opens, &open->list); tal_free(open); return res; } static struct command_result * json_openchannel2_sign_call(struct command *cmd, const char *buf, const jsmntok_t *params) { struct channel_id cid; struct wally_psbt *psbt; const char *err; struct out_req *req; struct pending_open *open; size_t count; err = json_scan(tmpctx, buf, params, "{openchannel2_sign:" "{channel_id:%,psbt:%}}", JSON_SCAN(json_to_channel_id, &cid), JSON_SCAN_TAL(cmd, json_to_psbt, &psbt)); if (err) plugin_err(cmd->plugin, "`openchannel2_sign` payload did not scan %s: %.*s", err, json_tok_full_len(params), json_tok_full(buf, params)); /* If we're not tracking this open, just pass through */ open = find_channel_pending_open(&cid); if (!open) { plugin_log(cmd->plugin, LOG_DBG, "nothing to sign for channel %s", type_to_string(tmpctx, struct channel_id, &cid)); return command_hook_cont_psbt(cmd, psbt); } if (!psbt_has_our_input(psbt)) { plugin_log(cmd->plugin, LOG_DBG, "no inputs to sign for channel %s", type_to_string(tmpctx, struct channel_id, &cid)); return command_hook_cont_psbt(cmd, psbt); } plugin_log(cmd->plugin, LOG_DBG, "openchannel_sign PSBT is %s", type_to_string(tmpctx, struct wally_psbt, psbt)); req = jsonrpc_request_start(cmd->plugin, cmd, "signpsbt", &signpsbt_done, &forward_error, open); json_add_psbt(req->js, "psbt", psbt); /* Use input markers to identify which inputs * are ours, only sign those */ json_array_start(req->js, "signonly"); count = 0; for (size_t i = 0; i < psbt->num_inputs; i++) { if (psbt_input_is_ours(&psbt->inputs[i])) { json_add_num(req->js, NULL, i); count++; } } json_array_end(req->js); plugin_log(cmd->plugin, LOG_DBG, "calling `signpsbt` for channel %s for %zu input%s", type_to_string(tmpctx, struct channel_id, &open->channel_id), count, count == 1 ? "" : "s"); return send_outreq(cmd->plugin, req); } static struct command_result * json_openchannel2_changed_call(struct command *cmd, const char *buf, const jsmntok_t *params) { struct channel_id cid; struct wally_psbt *psbt; const char *err; err = json_scan(tmpctx, buf, params, "{openchannel2_changed:" "{channel_id:%,psbt:%}}", JSON_SCAN(json_to_channel_id, &cid), JSON_SCAN_TAL(cmd, json_to_psbt, &psbt)); if (err) plugin_err(cmd->plugin, "`openchannel2_changed` payload did not" " scan %s: %.*s", err, json_tok_full_len(params), json_tok_full(buf, params)); plugin_log(cmd->plugin, LOG_DBG, "openchannel_changed PSBT is %s", type_to_string(tmpctx, struct wally_psbt, psbt)); /* FIXME: do we have any additions or updates to make based * on their changes? */ /* For now, we assume we're the same as before and continue * on as planned */ return command_hook_cont_psbt(cmd, psbt); } /* Tiny struct to pass info to callback for fundpsbt */ struct open_info { struct channel_id cid; struct node_id id; struct amount_sat our_funding; struct amount_sat their_funding; /* If this is an RBF, we'll have this */ struct amount_sat *their_last_funding; struct amount_sat *our_last_funding; struct amount_sat channel_max; u64 funding_feerate_perkw; u32 locktime; u32 lease_blockheight; u32 node_blockheight; struct amount_sat requested_lease; /* List of previously-used utxos */ struct bitcoin_outpoint **prev_outs; }; static struct open_info *new_open_info(const tal_t *ctx) { struct open_info *info = tal(ctx, struct open_info); info->their_last_funding = NULL; info->our_last_funding = NULL; info->requested_lease = AMOUNT_SAT(0); info->lease_blockheight = 0; info->node_blockheight = 0; info->prev_outs = NULL; return info; } static struct command_result * psbt_funded(struct command *cmd, const char *buf, const jsmntok_t *result, struct open_info *info) { struct wally_psbt *psbt; struct json_stream *response; struct amount_msat our_funding_msat; const char *err; err = json_scan(tmpctx, buf, result, "{psbt:%}", JSON_SCAN_TAL(tmpctx, json_to_psbt, &psbt)); if (err) plugin_err(cmd->plugin, "`fundpsbt` response did not scan %s: %.*s", err, json_tok_full_len(result), json_tok_full(buf, result)); /* We also mark all of our inputs as *ours*, so we * can easily identify them for `signpsbt` later */ for (size_t i = 0; i < psbt->num_inputs; i++) psbt_input_mark_ours(psbt, &psbt->inputs[i]); new_channel_open(cmd->plugin, cmd->plugin, info->id, info->cid, psbt); if (!amount_sat_to_msat(&our_funding_msat, info->our_funding)) abort(); response = jsonrpc_stream_success(cmd); json_add_string(response, "result", "continue"); json_add_psbt(response, "psbt", psbt); json_add_amount_msat(response, "our_funding_msat", our_funding_msat); /* If we're accepting an lease request, *and* they've * requested one, fill in our most recent infos */ if (current_policy->rates && !amount_sat_zero(info->requested_lease)) json_add_lease_rates(response, current_policy->rates); return command_finished(cmd, response); } static struct command_result * psbt_fund_failed(struct command *cmd, const char *buf, const jsmntok_t *error, struct open_info *info) { /* Attempt to fund a psbt for this open failed. * We probably ran out of funds (race?) */ plugin_log(cmd->plugin, LOG_INFORM, "Unable to secure %s from wallet," " continuing channel open to %s" " without our participation. err %.*s", type_to_string(tmpctx, struct amount_sat, &info->our_funding), type_to_string(tmpctx, struct node_id, &info->id), json_tok_full_len(error), json_tok_full(buf, error)); return command_hook_success(cmd); } /* They give msats, we want sats */ static bool json_to_msat_as_sats(const char *buffer, const jsmntok_t *tok, struct amount_sat *sat) { struct amount_msat msat; if (!json_to_msat(buffer, tok, &msat)) return false; return amount_msat_to_sat(sat, msat); } static struct command_result *param_msat_as_sat(struct command *cmd, const char *name, const char *buffer, const jsmntok_t *tok, struct amount_sat **sat) { struct amount_msat msat; *sat = tal(cmd, struct amount_sat); if (parse_amount_msat(&msat, buffer + tok->start, tok->end - tok->start) && amount_msat_to_sat(*sat, msat)) return NULL; return command_fail_badparam(cmd, name, buffer, tok, "should be a millisatoshi amount"); } static struct bitcoin_outpoint * previously_reserved(struct bitcoin_outpoint **prev_outs, struct bitcoin_outpoint *out) { for (size_t i = 0; i < tal_count(prev_outs); i++) { if (bitcoin_outpoint_eq(prev_outs[i], out)) return prev_outs[i]; } return NULL; } struct funder_utxo { struct bitcoin_outpoint out; struct amount_sat val; }; static struct out_req * build_utxopsbt_request(struct command *cmd, struct open_info *info, struct bitcoin_outpoint **prev_outs, struct amount_sat requested_funds, struct amount_sat committed_funds, struct funder_utxo **avail_utxos) { struct out_req *req; req = jsonrpc_request_start(cmd->plugin, cmd, "utxopsbt", &psbt_funded, &psbt_fund_failed, info); /* Add every prev_out */ json_array_start(req->js, "utxos"); for (size_t i = 0; i < tal_count(prev_outs); i++) json_add_outpoint(req->js, NULL, prev_outs[i]); /* Next add available utxos until we surpass the * requested funds goal */ /* FIXME: Update `utxopsbt` to automatically add more inputs? */ for (size_t i = 0; i < tal_count(avail_utxos); i++) { /* If we've already hit our goal, break */ if (amount_sat_greater_eq(committed_funds, requested_funds)) break; /* Add this output to the UTXO */ json_add_outpoint(req->js, NULL, &avail_utxos[i]->out); /* Account for it */ if (!amount_sat_add(&committed_funds, committed_funds, avail_utxos[i]->val)) /* This should really never happen */ plugin_err(cmd->plugin, "overflow adding committed"); } json_array_end(req->js); return req; } static struct command_result * listfunds_success(struct command *cmd, const char *buf, const jsmntok_t *result, struct open_info *info) { struct amount_sat available_funds, committed_funds, est_fee; const jsmntok_t *outputs_tok, *tok; struct out_req *req; struct bitcoin_outpoint **avail_prev_outs; size_t i; const char *funding_err; /* We only use this for RBFs, when there's a prev_outs list */ struct funder_utxo **avail_utxos = tal_arr(cmd, struct funder_utxo *, 0); outputs_tok = json_get_member(buf, result, "outputs"); if (!outputs_tok) plugin_err(cmd->plugin, "`listfunds` payload has no outputs token: %*.s", json_tok_full_len(result), json_tok_full(buf, result)); available_funds = AMOUNT_SAT(0); committed_funds = AMOUNT_SAT(0); avail_prev_outs = tal_arr(info, struct bitcoin_outpoint *, 0); json_for_each_arr(i, tok, outputs_tok) { struct funder_utxo *utxo; bool is_reserved; struct bitcoin_outpoint *prev_out; char *status; const char *err; utxo = tal(cmd, struct funder_utxo); err = json_scan(tmpctx, buf, tok, "{amount_msat:%" ",status:%" ",reserved:%" ",txid:%" ",output:%}", JSON_SCAN(json_to_msat_as_sats, &utxo->val), JSON_SCAN_TAL(cmd, json_strdup, &status), JSON_SCAN(json_to_bool, &is_reserved), JSON_SCAN(json_to_txid, &utxo->out.txid), JSON_SCAN(json_to_number, &utxo->out.n)); if (err) plugin_err(cmd->plugin, "`listfunds` payload did not scan. %s: %*.s", err, json_tok_full_len(result), json_tok_full(buf, result)); /* v2 opens don't support p2sh-wrapped inputs */ if (json_get_member(buf, tok, "redeemscript")) continue; /* The estimated fee per utxo. */ est_fee = amount_tx_fee(info->funding_feerate_perkw, bitcoin_tx_input_weight(false, 110)); /* Did we use this utxo on a previous attempt? */ prev_out = previously_reserved(info->prev_outs, &utxo->out); /* we skip reserved funds that aren't in our previous * inputs list! */ if (is_reserved && !prev_out) continue; /* we skip unconfirmed+spent funds */ if (!streq(status, "confirmed")) continue; /* Don't include outputs that can't cover their weight; * subtract the fee for this utxo out of the utxo */ if (!amount_sat_sub(&utxo->val, utxo->val, est_fee)) continue; if (!amount_sat_add(&available_funds, available_funds, utxo->val)) plugin_err(cmd->plugin, "`listfunds` overflowed output values"); /* If this is an RBF, we keep track of available utxos */ if (info->prev_outs) { /* if not previously reserved, it's committed */ if (!prev_out) { tal_arr_expand(&avail_utxos, utxo); continue; } if (!amount_sat_add(&committed_funds, committed_funds, utxo->val)) plugin_err(cmd->plugin, "`listfunds` overflowed" " committed output values"); /* We also keep a second list of utxos, * as it's possible some utxos got spent * between last attempt + this one! */ tal_arr_expand(&avail_prev_outs, prev_out); } } funding_err = calculate_our_funding(current_policy, info->id, info->their_funding, info->our_last_funding, available_funds, info->channel_max, info->requested_lease, &info->our_funding); plugin_log(cmd->plugin, LOG_DBG, "Policy %s returned funding amount of %s. %s", funder_policy_desc(tmpctx, current_policy), type_to_string(tmpctx, struct amount_sat, &info->our_funding), funding_err ? funding_err : ""); if (amount_sat_zero(info->our_funding)) return command_hook_success(cmd); plugin_log(cmd->plugin, LOG_DBG, "Funding channel %s with %s (their input %s)", type_to_string(tmpctx, struct channel_id, &info->cid), type_to_string(tmpctx, struct amount_sat, &info->our_funding), type_to_string(tmpctx, struct amount_sat, &info->their_funding)); /* If there's prevouts, we compose a psbt with those first, * then add more funds for anything missing */ if (info->prev_outs) { req = build_utxopsbt_request(cmd, info, avail_prev_outs, info->our_funding, committed_funds, avail_utxos); json_add_bool(req->js, "reservedok", true); /* We don't re-reserve any UTXOS :) */ json_add_num(req->js, "reserve", 0); } else { req = jsonrpc_request_start(cmd->plugin, cmd, "fundpsbt", &psbt_funded, &psbt_fund_failed, info); json_add_bool(req->js, "nonwrapped", true); } json_add_string(req->js, "satoshi", type_to_string(tmpctx, struct amount_sat, &info->our_funding)); json_add_string(req->js, "feerate", tal_fmt(tmpctx, "%"PRIu64"%s", info->funding_feerate_perkw, feerate_style_name(FEERATE_PER_KSIPA))); /* Our startweight is zero because we're freeriding on their open * transaction ! */ json_add_num(req->js, "startweight", 0); json_add_num(req->js, "min_witness_weight", 110); json_add_bool(req->js, "excess_as_change", true); json_add_num(req->js, "locktime", info->locktime); return send_outreq(cmd->plugin, req); } static struct command_result * listfunds_failed(struct command *cmd, const char *buf, const jsmntok_t *error, struct open_info *info) { /* Something went wrong fetching the funds info * for our wallet. Just keep going */ plugin_log(cmd->plugin, LOG_INFORM, "Unable to fetch wallet funds info." " Continuing channel open to %s" " without our participation. err %.*s", type_to_string(tmpctx, struct node_id, &info->id), json_tok_full_len(error), json_tok_full(buf, error)); return command_hook_success(cmd); } static struct command_result * json_openchannel2_call(struct command *cmd, const char *buf, const jsmntok_t *params) { struct open_info *info = new_open_info(cmd); struct amount_msat max_htlc_inflight, htlc_minimum; u64 commitment_feerate_perkw, feerate_our_max, feerate_our_min; u32 to_self_delay, max_accepted_htlcs; u16 channel_flags; const char *err; struct out_req *req; err = json_scan(tmpctx, buf, params, "{openchannel2:" "{id:%" ",channel_id:%" ",their_funding_msat:%" ",max_htlc_value_in_flight_msat:%" ",htlc_minimum_msat:%" ",funding_feerate_per_kw:%" ",commitment_feerate_per_kw:%" ",feerate_our_max:%" ",feerate_our_min:%" ",to_self_delay:%" ",max_accepted_htlcs:%" ",channel_flags:%" ",locktime:%" ",channel_max_msat:%}}", JSON_SCAN(json_to_node_id, &info->id), JSON_SCAN(json_to_channel_id, &info->cid), JSON_SCAN(json_to_msat_as_sats, &info->their_funding), JSON_SCAN(json_to_msat, &max_htlc_inflight), JSON_SCAN(json_to_msat, &htlc_minimum), JSON_SCAN(json_to_u64, &info->funding_feerate_perkw), JSON_SCAN(json_to_u64, &commitment_feerate_perkw), JSON_SCAN(json_to_u64, &feerate_our_max), JSON_SCAN(json_to_u64, &feerate_our_min), JSON_SCAN(json_to_u32, &to_self_delay), JSON_SCAN(json_to_u32, &max_accepted_htlcs), JSON_SCAN(json_to_u16, &channel_flags), JSON_SCAN(json_to_u32, &info->locktime), JSON_SCAN(json_to_msat_as_sats, &info->channel_max)); if (err) plugin_err(cmd->plugin, "`openchannel2` payload did not scan %s: %.*s", err, json_tok_full_len(params), json_tok_full(buf, params)); /* Channel lease info isn't necessarily included, ignore any err */ json_scan(tmpctx, buf, params, "{openchannel2:{" "requested_lease_msat:%" ",lease_blockheight_start:%" ",node_blockheight:%}}", JSON_SCAN(json_to_msat_as_sats, &info->requested_lease), JSON_SCAN(json_to_u32, &info->lease_blockheight), JSON_SCAN(json_to_u32, &info->node_blockheight)); /* We don't fund anything that's above or below our feerate */ if (info->funding_feerate_perkw < feerate_our_min || info->funding_feerate_perkw > feerate_our_max) { plugin_log(cmd->plugin, LOG_DBG, "their feerate %"PRIu64" is out of" " our bounds (%"PRIu64"-%"PRIu64")", info->funding_feerate_perkw, feerate_our_min, feerate_our_max); return command_hook_success(cmd); } /* If they've requested funds, but we're not actually * supporting requested funds...*/ if (!current_policy->rates && !amount_sat_zero(info->requested_lease)) { struct json_stream *res = jsonrpc_stream_success(cmd); json_add_string(res, "result", "reject"); json_add_string(res, "error_message", "Peer requested funds but we're not advertising" " liquidity right now"); return command_finished(cmd, res); } /* Check that their block height isn't too far behind */ if (!amount_sat_zero(info->requested_lease)) { u32 upper_bound, lower_bound; /* BOLT- #2: * The receiving node: * - MAY fail the negotiation if: ... * - if the `option_will_fund` tlv is present and: * - the `blockheight` is considered too far in the * past or future */ /* We consider 24 hrs too far out */ upper_bound = info->node_blockheight + 24 * 6; lower_bound = info->node_blockheight - 24 * 6; /* Check overflow */ if (upper_bound < info->node_blockheight) upper_bound = -1; if (lower_bound > info->node_blockheight) lower_bound = 0; if (upper_bound < info->lease_blockheight || lower_bound > info->lease_blockheight) { plugin_log(cmd->plugin, LOG_DBG, "their blockheight %d is out of" " our bounds (ours is %d)", info->lease_blockheight, info->node_blockheight); return command_hook_success(cmd); } } /* Figure out what our funds are */ req = jsonrpc_request_start(cmd->plugin, cmd, "listfunds", &listfunds_success, &listfunds_failed, info); return send_outreq(cmd->plugin, req); } static struct command_result * datastore_list_fail(struct command *cmd, const char *buf, const jsmntok_t *error, struct open_info *info) { struct out_req *req; /* Oops, something's broken */ plugin_log(cmd->plugin, LOG_BROKEN, "`datastore` list failed: %*.s", json_tok_full_len(error), json_tok_full(buf, error)); /* Figure out what our funds are... same flow * as with openchannel2 callback. */ req = jsonrpc_request_start(cmd->plugin, cmd, "listfunds", &listfunds_success, &listfunds_failed, info); return send_outreq(cmd->plugin, req); } static struct command_result * datastore_list_success(struct command *cmd, const char *buf, const jsmntok_t *result, struct open_info *info) { struct out_req *req; const char *key, *err; const u8 *utxos_bin; size_t len, i; const jsmntok_t *ds_arr_tok, *ds_result; ds_arr_tok = json_get_member(buf, result, "datastore"); assert(ds_arr_tok->type == JSMN_ARRAY); /* There should only be one result */ utxos_bin = NULL; json_for_each_arr(i, ds_result, ds_arr_tok) { err = json_scan(tmpctx, buf, ds_result, "{key:%,hex:%}", JSON_SCAN_TAL(cmd, json_strdup, &key), JSON_SCAN_TAL(cmd, json_tok_bin_from_hex, &utxos_bin)); if (err) plugin_err(cmd->plugin, "`listdatastore` payload did" " not scan. %s: %*.s", err, json_tok_full_len(result), json_tok_full(buf, result)); /* We found the prev utxo list */ plugin_log(cmd->plugin, LOG_DBG, "Saved utxos for channel (%s)" " pulled from datastore", key); /* There should only be one result */ break; } /* Resurrect outpoints from stashed binary */ len = tal_bytelen(utxos_bin); while (len > 0) { struct bitcoin_outpoint *outpoint = tal(info, struct bitcoin_outpoint); fromwire_bitcoin_outpoint(&utxos_bin, &len, outpoint); /* Cursor gets set to null if above fails */ if (!utxos_bin) plugin_err(cmd->plugin, "Unable to parse saved utxos: %.*s", json_tok_full_len(result), json_tok_full(buf, result)); if (!info->prev_outs) info->prev_outs = tal_arr(info, struct bitcoin_outpoint *, 0); tal_arr_expand(&info->prev_outs, outpoint); } req = jsonrpc_request_start(cmd->plugin, cmd, "listfunds", &listfunds_success, &listfunds_failed, info); return send_outreq(cmd->plugin, req); } /* Peer has asked us to RBF */ static struct command_result * json_rbf_channel_call(struct command *cmd, const char *buf, const jsmntok_t *params) { struct open_info *info = new_open_info(cmd); u64 feerate_our_max, feerate_our_min; const char *err, *chan_key; struct out_req *req; info->their_last_funding = tal(info, struct amount_sat); info->our_last_funding = tal(info, struct amount_sat); err = json_scan(tmpctx, buf, params, "{rbf_channel:" "{id:%" ",channel_id:%" ",their_last_funding_msat:%" ",their_funding_msat:%" ",our_last_funding_msat:%" ",funding_feerate_per_kw:%" ",feerate_our_max:%" ",feerate_our_min:%" ",locktime:%" ",channel_max_msat:%}}", JSON_SCAN(json_to_node_id, &info->id), JSON_SCAN(json_to_channel_id, &info->cid), JSON_SCAN(json_to_msat_as_sats, info->their_last_funding), JSON_SCAN(json_to_msat_as_sats, &info->their_funding), JSON_SCAN(json_to_msat_as_sats, info->our_last_funding), JSON_SCAN(json_to_u64, &info->funding_feerate_perkw), JSON_SCAN(json_to_u64, &feerate_our_max), JSON_SCAN(json_to_u64, &feerate_our_min), JSON_SCAN(json_to_u32, &info->locktime), JSON_SCAN(json_to_msat_as_sats, &info->channel_max)); if (err) plugin_err(cmd->plugin, "`rbf_channel` payload did not scan %s: %.*s", err, json_tok_full_len(params), json_tok_full(buf, params)); /* Lease info isn't necessarily included, ignore any err */ /* FIXME: blockheights?? */ json_scan(tmpctx, buf, params, "{rbf_channel:{" "requested_lease_msat:%}}", JSON_SCAN(json_to_msat_as_sats, &info->requested_lease)); /* We don't fund anything that's above or below our feerate */ if (info->funding_feerate_perkw < feerate_our_min || info->funding_feerate_perkw > feerate_our_max) { plugin_log(cmd->plugin, LOG_DBG, "their feerate %"PRIu64" is out of" " our bounds (%"PRIu64"-%"PRIu64")", info->funding_feerate_perkw, feerate_our_min, feerate_our_max); return command_hook_success(cmd); } /* Fetch out previous utxos from the datastore */ req = jsonrpc_request_start(cmd->plugin, cmd, "listdatastore", &datastore_list_success, &datastore_list_fail, info); chan_key = tal_fmt(cmd, "funder/%s", type_to_string(cmd, struct channel_id, &info->cid)); json_add_string(req->js, "key", chan_key); return send_outreq(cmd->plugin, req); } static struct command_result *json_disconnect(struct command *cmd, const char *buf, const jsmntok_t *params) { struct node_id id; const char *err; err = json_scan(tmpctx, buf, params, "{disconnect:{id:%}}", JSON_SCAN(json_to_node_id, &id)); if (err) plugin_err(cmd->plugin, "`disconnect` notification payload did not" " scan %s: %.*s", err, json_tok_full_len(params), json_tok_full(buf, params)); plugin_log(cmd->plugin, LOG_DBG, "Cleaning up inflights for peer id %s", type_to_string(tmpctx, struct node_id, &id)); cleanup_peer_pending_opens(&id); return notification_handled(cmd); } static struct command_result * delete_channel_from_datastore(struct command *cmd, struct channel_id *cid) { const struct out_req *req; /* Fetch out previous utxos from the datastore. * If we were clever, we'd have some way of tracking * channels that we actually might have data for * but this is much easier */ req = jsonrpc_request_start(cmd->plugin, cmd, "deldatastore", &datastore_del_success, &datastore_del_fail, NULL); json_add_string(req->js, "key", tal_fmt(cmd, "funder/%s", type_to_string(cmd, struct channel_id, cid))); return send_outreq(cmd->plugin, req); } static struct command_result *json_channel_state_changed(struct command *cmd, const char *buf, const jsmntok_t *params) { struct channel_id cid; const char *err, *old_state, *new_state; err = json_scan(tmpctx, buf, params, "{channel_state_changed:" "{channel_id:%" ",old_state:%" ",new_state:%}}", JSON_SCAN(json_to_channel_id, &cid), JSON_SCAN_TAL(cmd, json_strdup, &old_state), JSON_SCAN_TAL(cmd, json_strdup, &new_state)); if (err) plugin_err(cmd->plugin, "`channel_state_changed` notification payload did" " not scan %s: %.*s", err, json_tok_full_len(params), json_tok_full(buf, params)); /* Moving out of "awaiting lockin", * means we clean up the datastore */ /* FIXME: splicing state? */ if (!streq(old_state, "DUALOPEND_AWAITING_LOCKIN") && !streq(old_state, "CHANNELD_AWAITING_LOCKIN")) return notification_handled(cmd); plugin_log(cmd->plugin, LOG_DBG, "Cleaning up datastore for channel_id %s", type_to_string(tmpctx, struct channel_id, &cid)); return delete_channel_from_datastore(cmd, &cid); } static struct command_result *json_channel_open_failed(struct command *cmd, const char *buf, const jsmntok_t *params) { struct channel_id cid; struct pending_open *open; const char *err; err = json_scan(tmpctx, buf, params, "{channel_open_failed:" "{channel_id:%}}", JSON_SCAN(json_to_channel_id, &cid)); if (err) plugin_err(cmd->plugin, "`channel_open_failed` notification payload did" " not scan %s: %.*s", err, json_tok_full_len(params), json_tok_full(buf, params)); plugin_log(cmd->plugin, LOG_DBG, "Cleaning up inflight for channel_id %s", type_to_string(tmpctx, struct channel_id, &cid)); open = find_channel_pending_open(&cid); if (open) unreserve_psbt(open); /* Also clean up datastore for this channel */ return delete_channel_from_datastore(cmd, &cid); } static void json_add_policy(struct json_stream *stream, struct funder_policy *policy) { json_add_string(stream, "summary", funder_policy_desc(stream, current_policy)); json_add_string(stream, "policy", funder_opt_name(policy->opt)); json_add_num(stream, "policy_mod", policy->mod); json_add_bool(stream, "leases_only", policy->leases_only); json_add_amount_sat_msat(stream, "min_their_funding_msat", policy->min_their_funding); json_add_amount_sat_msat(stream, "max_their_funding_msat", policy->max_their_funding); json_add_amount_sat_msat(stream, "per_channel_min_msat", policy->per_channel_min); json_add_amount_sat_msat(stream, "per_channel_max_msat", policy->per_channel_max); json_add_amount_sat_msat(stream, "reserve_tank_msat", policy->reserve_tank); json_add_num(stream, "fuzz_percent", policy->fuzz_factor); json_add_num(stream, "fund_probability", policy->fund_probability); if (policy->rates) { json_add_lease_rates(stream, policy->rates); json_add_string(stream, "compact_lease", lease_rates_tohex(tmpctx, policy->rates)); } } static struct command_result * param_funder_opt(struct command *cmd, const char *name, const char *buffer, const jsmntok_t *tok, enum funder_opt **opt) { char *opt_str, *err; *opt = tal(cmd, enum funder_opt); opt_str = tal_strndup(cmd, buffer + tok->start, tok->end - tok->start); err = funding_option(cmd->plugin, opt_str, *opt); if (err) return command_fail_badparam(cmd, name, buffer, tok, err); return NULL; } static struct command_result * param_policy_mod(struct command *cmd, const char *name, const char *buffer, const jsmntok_t *tok, u64 **mod) { struct amount_sat sats; char *arg_str, *err; *mod = tal(cmd, u64); arg_str = tal_strndup(cmd, buffer + tok->start, tok->end - tok->start); err = u64_option(cmd->plugin, arg_str, *mod); if (err) { tal_free(err); if (!parse_amount_sat(&sats, arg_str, strlen(arg_str))) return command_fail_badparam(cmd, name, buffer, tok, err); **mod = sats.satoshis; /* Raw: convert to u64 */ } return NULL; } static struct command_result * parse_lease_rates(struct command *cmd, const char *buffer, const jsmntok_t *tok, struct funder_policy *policy, struct funder_policy *current_policy, u32 *lease_fee_basis, struct amount_sat *lease_fee_sats, u32 *funding_weight, u32 *channel_fee_max_proportional_thousandths, struct amount_msat *chan_fee_msats) { /* If there's already rates set, we start with those */ if (!lease_rates_empty(current_policy->rates)) policy->rates = tal_dup(policy, struct lease_rates, current_policy->rates); else if (lease_fee_basis || lease_fee_sats || funding_weight || channel_fee_max_proportional_thousandths || chan_fee_msats) policy->rates = default_lease_rates(policy); else policy->rates = NULL; /* Sometimes a local macro is neater than the alternative */ #define ASSIGN_OR_RETURN_FAIL(type, member) \ do { \ if (member && \ !assign_overflow_##type(&policy->rates->member, *member)) \ return command_fail_badparam(cmd, #member, \ buffer, tok, "overflow"); \ } while(0) ASSIGN_OR_RETURN_FAIL(u16, lease_fee_basis); ASSIGN_OR_RETURN_FAIL(u16, funding_weight); ASSIGN_OR_RETURN_FAIL(u16, channel_fee_max_proportional_thousandths); #undef ASSIGN_OR_RETURN_FAIL if (chan_fee_msats && !assign_overflow_u32(&policy->rates->channel_fee_max_base_msat, chan_fee_msats->millisatoshis /* Raw: conversion */)) { return command_fail_badparam(cmd, "channel_fee_max_base_msat", buffer, tok, "overflow"); } if (lease_fee_sats && !assign_overflow_u32(&policy->rates->lease_fee_base_sat, lease_fee_sats->satoshis /* Raw: conversion */)) { return command_fail_badparam(cmd, "lease_fee_base_sat", buffer, tok, "overflow"); } return NULL; } static struct command_result * leaserates_set(struct command *cmd, const char *buf, const jsmntok_t *result, struct funder_policy *policy) { struct json_stream *res; /* Ok, we updated lightningd with latest info */ res = jsonrpc_stream_success(cmd); json_add_policy(res, policy); return command_finished(cmd, res); } static struct command_result * json_funderupdate(struct command *cmd, const char *buf, const jsmntok_t *params) { struct amount_sat *min_their_funding, *max_their_funding, *per_channel_min, *per_channel_max, *reserve_tank, *lease_fee_sats; struct amount_msat *channel_fee_msats; u32 *fuzz_factor, *fund_probability, *chan_fee_ppt, *lease_fee_basis, *funding_weight; u64 *mod; bool *leases_only; enum funder_opt *opt; const struct out_req *req; const char *err; struct command_result *res; struct funder_policy *policy = tal(cmd, struct funder_policy); if (!param(cmd, buf, params, p_opt_def("policy", param_funder_opt, &opt, current_policy->opt), p_opt_def("policy_mod", param_policy_mod, &mod, current_policy->mod), p_opt_def("leases_only", param_bool, &leases_only, current_policy->leases_only), p_opt_def("min_their_funding_msat", param_msat_as_sat, &min_their_funding, current_policy->min_their_funding), p_opt_def("max_their_funding_msat", param_msat_as_sat, &max_their_funding, current_policy->max_their_funding), p_opt_def("per_channel_min_msat", param_msat_as_sat, &per_channel_min, current_policy->per_channel_min), p_opt_def("per_channel_max_msat", param_msat_as_sat, &per_channel_max, current_policy->per_channel_max), p_opt_def("reserve_tank_msat", param_msat_as_sat, &reserve_tank, current_policy->reserve_tank), p_opt_def("fuzz_percent", param_number, &fuzz_factor, current_policy->fuzz_factor), p_opt_def("fund_probability", param_number, &fund_probability, current_policy->fund_probability), p_opt("lease_fee_base_msat", param_msat_as_sat, &lease_fee_sats), p_opt("lease_fee_basis", param_number, &lease_fee_basis), p_opt("funding_weight", param_number, &funding_weight), p_opt("channel_fee_max_base_msat", param_msat, &channel_fee_msats), p_opt("channel_fee_max_proportional_thousandths", param_number, &chan_fee_ppt), NULL)) return command_param_failed(); policy->opt = *opt; policy->mod = *mod; policy->min_their_funding = *min_their_funding; policy->max_their_funding = *max_their_funding; policy->per_channel_min = *per_channel_min; policy->per_channel_max = *per_channel_max; policy->reserve_tank = *reserve_tank; policy->fuzz_factor = *fuzz_factor; policy->fund_probability = *fund_probability; policy->leases_only = *leases_only; res = parse_lease_rates(cmd, buf, params, policy, current_policy, lease_fee_basis, lease_fee_sats, funding_weight, chan_fee_ppt, channel_fee_msats); if (res) return res; err = funder_check_policy(policy); if (err) { tal_free(policy); return command_done_err(cmd, JSONRPC2_INVALID_PARAMS, err, NULL); } tal_free(current_policy); current_policy = tal_steal(NULL, policy); /* Update lightningd, also */ req = jsonrpc_request_start(cmd->plugin, cmd, "setleaserates", &leaserates_set, &forward_error, current_policy); if (current_policy->rates) json_add_lease_rates(req->js, current_policy->rates); else { /* Add empty rates to turn off */ struct lease_rates rates; memset(&rates, 0, sizeof(rates)); json_add_lease_rates(req->js, &rates); } return send_outreq(cmd->plugin, req); } static const struct plugin_command commands[] = { { "funderupdate", "liquidity", "Configuration for dual-funding settings.", "Update current settings. Modifies how node reacts to" " incoming channel open requests. Responds with list" " of current configs.", json_funderupdate }, }; static void tell_lightningd_lease_rates(struct plugin *p, struct lease_rates *rates) { struct json_out *jout; struct amount_msat mval; /* Tell lightningd with our lease rates*/ jout = json_out_new(NULL); json_out_start(jout, NULL, '{'); mval = amount_msat(rates->lease_fee_base_sat * 1000); json_out_addstr(jout, "lease_fee_base_msat", type_to_string(tmpctx, struct amount_msat, &mval)); json_out_add(jout, "lease_fee_basis", false, "%d", rates->lease_fee_basis); json_out_add(jout, "funding_weight", false, "%d", rates->funding_weight); mval = amount_msat(rates->channel_fee_max_base_msat); json_out_addstr(jout, "channel_fee_max_base_msat", type_to_string(tmpctx, struct amount_msat, &mval)); json_out_add(jout, "channel_fee_max_proportional_thousandths", false, "%d", rates->channel_fee_max_proportional_thousandths); json_out_end(jout, '}'); json_out_finished(jout); rpc_scan(p, "setleaserates", take(jout), /* Unused */ "{lease_fee_base_msat:%}", JSON_SCAN(json_to_msat, &mval)); } static void memleak_mark(struct plugin *p, struct htable *memtable) { memleak_scan_list_head(memtable, &pending_opens); memleak_scan_obj(memtable, current_policy); } static const char *init(struct plugin *p, const char *b, const jsmntok_t *t) { const char *err; list_head_init(&pending_opens); err = funder_check_policy(current_policy); if (err) plugin_err(p, "Invalid parameter combination: %s", err); if (current_policy->rates) tell_lightningd_lease_rates(p, current_policy->rates); plugin_set_memleak_handler(p, memleak_mark); return NULL; } const struct plugin_hook hooks[] = { { "openchannel2", json_openchannel2_call, }, { "openchannel2_changed", json_openchannel2_changed_call, }, { "openchannel2_sign", json_openchannel2_sign_call, }, { "rbf_channel", json_rbf_channel_call, }, }; const struct plugin_notification notifs[] = { { "channel_open_failed", json_channel_open_failed, }, { "disconnect", json_disconnect, }, { "channel_state_changed", json_channel_state_changed, }, }; static char *option_channel_base(struct plugin *plugin, const char *arg, struct funder_policy *policy) { struct amount_msat amt; if (!parse_amount_msat(&amt, arg, strlen(arg))) return tal_fmt(tmpctx, "Unable to parse amount '%s'", arg); if (!policy->rates) policy->rates = default_lease_rates(policy); if (!assign_overflow_u32(&policy->rates->channel_fee_max_base_msat, amt.millisatoshis)) /* Raw: conversion */ return tal_fmt(tmpctx, "channel_fee_max_base_msat overflowed"); return NULL; } static char * option_channel_fee_proportional_thousandths_max(struct plugin *plugin, const char *arg, struct funder_policy *policy) { if (!policy->rates) policy->rates = default_lease_rates(policy); return u16_option(plugin, arg, &policy->rates->channel_fee_max_proportional_thousandths); } static char *amount_option(struct plugin *plugin, const char *arg, struct amount_sat *amt) { if (!parse_amount_sat(amt, arg, strlen(arg))) return tal_fmt(tmpctx, "Unable to parse amount '%s'", arg); return NULL; } static char *option_lease_fee_base(struct plugin *plugin, const char *arg, struct funder_policy *policy) { struct amount_sat amt; char *err; if (!policy->rates) policy->rates = default_lease_rates(policy); err = amount_option(plugin, arg, &amt); if (err) return err; if (!assign_overflow_u32(&policy->rates->lease_fee_base_sat, amt.satoshis)) /* Raw: conversion */ return tal_fmt(tmpctx, "lease_fee_base_sat overflowed"); return NULL; } static char *option_lease_fee_basis(struct plugin *plugin, const char *arg, struct funder_policy *policy) { if (!policy->rates) policy->rates = default_lease_rates(policy); return u16_option(plugin, arg, &policy->rates->lease_fee_basis); } static char *option_lease_weight_max(struct plugin *plugin, const char *arg, struct funder_policy *policy) { if (!policy->rates) policy->rates = default_lease_rates(policy); return u16_option(plugin, arg, &policy->rates->funding_weight); } static char *amount_sat_or_u64_option(struct plugin *plugin, const char *arg, u64 *amt) { struct amount_sat sats; char *err; err = u64_option(plugin, arg, amt); if (err) { tal_free(err); if (!parse_amount_sat(&sats, arg, strlen(arg))) return tal_fmt(tmpctx, "Unable to parse option '%s'", arg); *amt = sats.satoshis; /* Raw: convert to u64 */ } return NULL; } int main(int argc, char **argv) { setup_locale(); /* Our default funding policy is fixed (0msat) */ current_policy = default_funder_policy(NULL, FIXED, 0); plugin_main(argv, init, PLUGIN_RESTARTABLE, true, NULL, commands, ARRAY_SIZE(commands), notifs, ARRAY_SIZE(notifs), hooks, ARRAY_SIZE(hooks), NULL, 0, plugin_option("funder-policy", "string", "Policy to use for dual-funding requests." " [match, available, fixed]", funding_option, ¤t_policy->opt), plugin_option("funder-policy-mod", "string", "Percent to apply policy at" " (match/available); or amount to fund" " (fixed)", amount_sat_or_u64_option, ¤t_policy->mod), plugin_option("funder-min-their-funding", "string", "Minimum funding peer must open with" " to activate our policy", amount_option, ¤t_policy->min_their_funding), plugin_option("funder-max-their-funding", "string", "Maximum funding peer may open with" " to activate our policy", amount_option, ¤t_policy->max_their_funding), plugin_option("funder-per-channel-min", "string", "Minimum funding we'll add to a channel." " If we can't meet this, we don't fund", amount_option, ¤t_policy->per_channel_min), plugin_option("funder-per-channel-max", "string", "Maximum funding we'll add to a channel." " We cap all contributions to this", amount_option, ¤t_policy->per_channel_max), plugin_option("funder-reserve-tank", "string", "Amount of funds we'll always leave" " available.", amount_option, ¤t_policy->reserve_tank), plugin_option("funder-fuzz-percent", "int", "Percent to fuzz the policy contribution by." " Defaults to 0%. Max is 100%", u32_option, ¤t_policy->fuzz_factor), plugin_option("funder-fund-probability", "int", "Percent of requests to consider." " Defaults to 100%. Setting to 0% will" " disable dual-funding", u32_option, ¤t_policy->fund_probability), plugin_option("funder-lease-requests-only", "bool", "Only fund lease requests. Defaults to" " true if channel lease rates are" " being advertised", bool_option, ¤t_policy->leases_only), plugin_option("lease-fee-base-sat", "string", "Channel lease rates, base fee for leased" " funds, in satoshi.", option_lease_fee_base, current_policy), plugin_option_deprecated("lease-fee-base-msat", "string", "Channel lease rates, base fee for leased" " funds, in satoshi.", option_lease_fee_base, current_policy), plugin_option("lease-fee-basis", "int", "Channel lease rates, basis charged" " for leased funds (per 10,000 satoshi.)", option_lease_fee_basis, current_policy), plugin_option("lease-funding-weight", "int", "Channel lease rates, weight" " we'll ask opening peer to pay for in" " funding transaction", option_lease_weight_max, current_policy), plugin_option("channel-fee-max-base-msat", "string", "Channel lease rates, maximum channel" " fee base we'll charge for funds" " routed through a leased channel.", option_channel_base, current_policy), plugin_option("channel-fee-max-proportional-thousandths", "int", "Channel lease rates, maximum" " proportional fee (in thousandths, or ppt)" " we'll charge for funds routed through a" " leased channel. Note: 1ppt = 1,000ppm", option_channel_fee_proportional_thousandths_max, current_policy), NULL); tal_free(current_policy); return 0; }