Config: revive --commit-fee

doc/lightningd-config.5

@@ -332,8 +332,8 @@ opens a channel before the channel is usable\.
 
 
  \fBcommit-fee\fR=\fIPERCENT\fR
-The percentage of \fIestimatesmartfee 2\fR to use for the bitcoin
-transaction which funds a channel: can be greater than 100\.
+The percentage of \fIestimatesmartfee 2/CONSERVATIVE\fR to use for the commitment
+transactions: default is 100\.
 
 
  \fBcommit-fee-min\fR=\fIPERCENT\fR

doc/lightningd-config.5.md

@@ -270,8 +270,8 @@ Confirmations required for the funding transaction when the other side
 opens a channel before the channel is usable.
 
  **commit-fee**=*PERCENT*
-The percentage of *estimatesmartfee 2* to use for the bitcoin
-transaction which funds a channel: can be greater than 100.
+The percentage of *estimatesmartfee 2/CONSERVATIVE* to use for the commitment
+transactions: default is 100.
 
  **commit-fee-min**=*PERCENT*
  **commit-fee-max**=*PERCENT*

lightningd/lightningd.h

@@ -32,9 +32,6 @@ struct config {
 	/* Minimum percent of fee rate we'll accept. */
 	u32 commitment_fee_min_percent;
 
-	/* Percent of fee rate we'll use. */
-	u32 commitment_fee_percent;
-
 	/* Minimum CLTV to subtract from incoming HTLCs to outgoing */
 	u32 cltv_expiry_delta;
 

lightningd/options.c

@@ -571,9 +571,6 @@ static const struct config testnet_config = {
 	.commitment_fee_min_percent = 0,
 	.commitment_fee_max_percent = 0,
 
-	/* We offer to pay 5 times 2-block fee */
-	.commitment_fee_percent = 500,
-
 	/* Testnet blockspace is free. */
 	.max_concurrent_htlcs = 483,
 
@@ -619,9 +616,6 @@ static const struct config mainnet_config = {
 	.commitment_fee_min_percent = 200,
 	.commitment_fee_max_percent = 2000,
 
-	/* We offer to pay 5 times 2-block fee */
-	.commitment_fee_percent = 500,
-
 	/* While up to 483 htlcs are possible we do 30 by default (as eclair does) to save blockspace */
 	.max_concurrent_htlcs = 30,
 
@@ -820,9 +814,6 @@ static void register_opts(struct lightningd *ld)
 	opt_register_arg("--commit-fee-max=<percent>", opt_set_u32, opt_show_u32,
 			 &ld->config.commitment_fee_max_percent,
 			 "Maximum percentage of fee to accept for commitment (0 for unlimited)");
-	opt_register_arg("--commit-fee=<percent>", opt_set_u32, opt_show_u32,
-			 &ld->config.commitment_fee_percent,
-			 "Percentage of fee to request for their commitment");
 	opt_register_arg("--cltv-delta", opt_set_u32, opt_show_u32,
 			 &ld->config.cltv_expiry_delta,
 			 "Number of blocks for cltv_expiry_delta");

plugins/bcli.c

@@ -63,6 +63,9 @@ struct bitcoind {
 	/* The factor to time the urgent feerate by to get the maximum
 	 * acceptable feerate. */
 	u32 max_fee_multiplier;
+
+	/* Percent of CONSERVATIVE/2 feerate we'll use for commitment txs. */
+	u64 commit_fee_percent;
 };
 
 static struct bitcoind *bitcoind;
@@ -531,7 +534,8 @@ static struct command_result *estimatefees_final_step(struct bitcoin_cli *bcli)
 	response = jsonrpc_stream_success(bcli->cmd);
 	json_add_u64(response, "opening", stash->normal);
 	json_add_u64(response, "mutual_close", stash->normal);
-	json_add_u64(response, "unilateral_close", stash->very_urgent);
+	json_add_u64(response, "unilateral_close",
+		     stash->very_urgent * bitcoind->commit_fee_percent / 100);
 	json_add_u64(response, "delayed_to_us", stash->normal);
 	json_add_u64(response, "htlc_resolution", stash->urgent);
 	json_add_u64(response, "penalty", stash->urgent);
@@ -580,7 +584,7 @@ static struct command_result *estimatefees_third_step(struct bitcoin_cli *bcli)
 	struct estimatefees_stash *stash = bcli->stash;
 	const char **params = tal_arr(bcli->cmd, const char *, 2);
 
-	/* If we cannot estimatefees, no need to continue bothering bitcoind. */
+	/* If we cannot estimate fees, no need to continue bothering bitcoind. */
 	if (*bcli->exitstatus != 0)
 		return estimatefees_null_response(bcli);
 
@@ -603,7 +607,7 @@ static struct command_result *estimatefees_second_step(struct bitcoin_cli *bcli)
 	struct estimatefees_stash *stash = bcli->stash;
 	const char **params = tal_arr(bcli->cmd, const char *, 2);
 
-	/* If we cannot estimatefees, no need to continue bothering bitcoind. */
+	/* If we cannot estimate fees, no need to continue bothering bitcoind. */
 	if (*bcli->exitstatus != 0)
 		return estimatefees_null_response(bcli);
 
@@ -750,13 +754,13 @@ static struct command_result *getchaininfo(struct command *cmd,
 	return command_still_pending(cmd);
 }
 
-/* Get the current feerates. We us an urgent feerate for unilateral_close and max,
+/* Get the current feerates. We use an urgent feerate for unilateral_close and max,
  * a slightly less urgent feerate for htlc_resolution and penalty transactions,
  * a slow feerate for min, and a normal one for all others.
  *
- * Calls `estimatesmartfee` with targets 2/CONSERVATIVE (urgent),
- * 4/ECONOMICAL (normal), and 100/ECONOMICAL (slow) then returns the
- * feerates as sat/kVB.
+ * Calls `estimatesmartfee` with targets 2/CONSERVATIVE (very urgent),
+ * 3/CONSERVATIVE (urgent), 4/ECONOMICAL (normal), and 100/ECONOMICAL (slow)
+ * then returns the feerates as sat/kVB.
  */
 static struct command_result *estimatefees(struct command *cmd,
 					   const char *buf UNUSED,
@@ -768,7 +772,8 @@ static struct command_result *estimatefees(struct command *cmd,
 	if (!param(cmd, buf, toks, NULL))
 	    return command_param_failed();
 
-	/* First call to estimatesmartfee, for urgent estimation. */
+	/* First call to estimatesmartfee, for very urgent estimation (unilateral
+	 * and max_acceptable feerates). */
 	params[0] = "2";
 	params[1] = "CONSERVATIVE";
 	start_bitcoin_cli(NULL, cmd, estimatefees_second_step, true,
@@ -927,12 +932,9 @@ static const struct plugin_command commands[] = {
 	},
 };
 
-int main(int argc, char *argv[])
+static struct bitcoind *new_bitcoind(const tal_t *ctx)
 {
-	setup_locale();
-
-	/* Initialize our global context object here to handle startup options. */
-	bitcoind = tal(NULL, struct bitcoind);
+	bitcoind = tal(ctx, struct bitcoind);
 
 	bitcoind->cli = NULL;
 	bitcoind->datadir = NULL;
@@ -947,6 +949,17 @@ int main(int argc, char *argv[])
 	bitcoind->rpcconnect = NULL;
 	bitcoind->rpcport = NULL;
 	bitcoind->max_fee_multiplier = 10;
+	bitcoind->commit_fee_percent = 100;
+
+	return bitcoind;
+}
+
+int main(int argc, char *argv[])
+{
+	setup_locale();
+
+	/* Initialize our global context object here to handle startup options. */
+	bitcoind = new_bitcoind(NULL);
 
 	plugin_main(argv, init, PLUGIN_STATIC, NULL, commands, ARRAY_SIZE(commands),
 		    NULL, 0, NULL, 0,
@@ -979,6 +992,10 @@ int main(int argc, char *argv[])
 				  "how long to keep retrying to contact bitcoind"
 				  " before fatally exiting",
 				  u64_option, &bitcoind->retry_timeout),
+		    plugin_option("commit-fee",
+				  "string",
+				  "Percentage of fee to request for their commitment",
+				  u64_option, &bitcoind->commit_fee_percent),
 #if DEVELOPER
 		    plugin_option("dev-max-fee-multiplier",
 				  "string",

tests/test_misc.py

@@ -2375,3 +2375,16 @@ def test_getsharedsecret(node_factory):
     # knowing only the public key of the other.
     assert (l1.rpc.getsharedsecret(l2.info["id"])["shared_secret"]
             == l2.rpc.getsharedsecret(l1.info["id"])["shared_secret"])
+
+
+def test_commitfee_option(node_factory):
+    """Sanity check for the --commit-fee startup option."""
+    l1, l2 = node_factory.get_nodes(2, opts=[{"commit-fee": "200"}, {}])
+
+    mock_wu = 5000
+    for l in [l1, l2]:
+        l.set_feerates((mock_wu, 0, 0, 0), True)
+    l1_commit_fees = l1.rpc.call("estimatefees")["unilateral_close"]
+    l2_commit_fees = l2.rpc.call("estimatefees")["unilateral_close"]
+
+    assert l1_commit_fees == 2 * l2_commit_fees == 2 * 4 * mock_wu  # WU->VB

wallet/test/test_utils.c

@@ -10,7 +10,6 @@ const struct config test_config = {
 	.anchor_confirms = 1,
 	.commitment_fee_min_percent = 0,
 	.commitment_fee_max_percent = 0,
-	.commitment_fee_percent = 500,
 	.cltv_expiry_delta = 6,
 	.cltv_final = 10,
 	.commit_time_ms = 10,