df: pass lease data back to funder for rbfs

let's let RBFs know about our lease info!

plugins/funder.c

@@ -272,11 +272,17 @@ struct open_info {
 	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;
 };
 
@@ -284,6 +290,8 @@ 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;
@@ -456,6 +464,7 @@ listfunds_success(struct command *cmd,
 	funding_err = calculate_our_funding(current_policy,
 					    info->id,
 					    info->their_funding,
+					    info->our_last_funding,
 					    available_funds,
 					    info->channel_max,
 					    info->requested_lease,
@@ -572,21 +581,15 @@ json_openchannel2_call(struct command *cmd,
 			   err, json_tok_full_len(params),
 			   json_tok_full(buf, params));
 
-	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->node_blockheight),
-			JSON_SCAN(json_to_u32, &info->lease_blockheight));
-
-	/* These aren't necessarily included */
-	if (err) {
-		info->requested_lease = AMOUNT_SAT(0);
-		info->node_blockheight = 0;
-		info->lease_blockheight = 0;
-	}
+	/* 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
@@ -670,11 +673,15 @@ json_rbf_channel_call(struct command *cmd,
 	const char *err;
 	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:%"
@@ -682,7 +689,12 @@ json_rbf_channel_call(struct command *cmd,
 			",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_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),
@@ -695,6 +707,13 @@ json_rbf_channel_call(struct command *cmd,
 			   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) {

plugins/funder_policy.c

@@ -208,6 +208,7 @@ const char *
 calculate_our_funding(struct funder_policy *policy,
 		      struct node_id id,
 		      struct amount_sat their_funding,
+		      struct amount_sat *our_last_funding,
 		      struct amount_sat available_funds,
 		      struct amount_sat channel_max,
 		      struct amount_sat requested_lease,
@@ -309,6 +310,22 @@ calculate_our_funding(struct funder_policy *policy,
 	if (amount_sat_greater(*our_funding, net_available_funds))
 		*our_funding = net_available_funds;
 
+	/* Are we putting in less than last time + it's a lease?
+	 * Return an error as a convenience to the buyer */
+	if (our_last_funding && !amount_sat_zero(requested_lease)) {
+		if (amount_sat_less(*our_funding, *our_last_funding)
+		    && amount_sat_less(*our_funding, requested_lease)) {
+			return tal_fmt(tmpctx, "New amount (%s) is less than"
+				       " last (%s); peer requested a lease (%s)",
+				       type_to_string(tmpctx, struct amount_sat,
+						      our_funding),
+				       type_to_string(tmpctx, struct amount_sat,
+						      our_last_funding),
+				       type_to_string(tmpctx, struct amount_sat,
+						      &requested_lease));
+		}
+	}
+
 	/* Is our_funding less than our per-channel minimum?
 	 * if so, don't fund */
 	if (amount_sat_less(*our_funding, policy->per_channel_min)) {

plugins/funder_policy.h

@@ -79,6 +79,7 @@ const char *
 calculate_our_funding(struct funder_policy *policy,
 		      struct node_id id,
 		      struct amount_sat their_funding,
+		      struct amount_sat *our_last_funding,
 		      struct amount_sat available_funds,
 		      struct amount_sat channel_max,
 		      struct amount_sat lease_request,

plugins/test/run-funder_policy.c

@@ -29,6 +29,7 @@ void towire_node_id(u8 **pptr UNNEEDED, const struct node_id *id UNNEEDED)
 struct test_case {
 	struct amount_sat their_funds;
 	struct amount_sat available_funds;
+	struct amount_sat *our_last_funds;
 	struct amount_sat channel_max;
 	struct amount_sat lease_request;
 
@@ -43,6 +44,7 @@ struct test_case cases[] = {
 	{
 		.their_funds = AMOUNT_SAT(5000),
 		.available_funds = AMOUNT_SAT(100000),
+		.our_last_funds = NULL,
 		.channel_max = AMOUNT_SAT(11000),
 		.lease_request = AMOUNT_SAT(0),
 		.policy = {
@@ -65,6 +67,7 @@ struct test_case cases[] = {
 	{
 		.their_funds = AMOUNT_SAT(5000),
 		.available_funds = AMOUNT_SAT(500),
+		.our_last_funds = NULL,
 		.channel_max = AMOUNT_SAT(11000),
 		.lease_request = AMOUNT_SAT(0),
 		.policy = {
@@ -87,6 +90,7 @@ struct test_case cases[] = {
 	{
 		.their_funds = AMOUNT_SAT(5000),
 		.available_funds = AMOUNT_SAT(6000),
+		.our_last_funds = NULL,
 		.channel_max = AMOUNT_SAT(11000),
 		.lease_request = AMOUNT_SAT(0),
 		.policy = {
@@ -109,6 +113,7 @@ struct test_case cases[] = {
 	{
 		.their_funds = AMOUNT_SAT(2500),
 		.available_funds = AMOUNT_SAT(6000),
+		.our_last_funds = NULL,
 		.channel_max = AMOUNT_SAT(11000),
 		.lease_request = AMOUNT_SAT(0),
 		.policy = {
@@ -131,6 +136,7 @@ struct test_case cases[] = {
 	{
 		.their_funds = AMOUNT_SAT(2500),
 		.available_funds = AMOUNT_SAT(5000),
+		.our_last_funds = NULL,
 		.channel_max = AMOUNT_SAT(11000),
 		.lease_request = AMOUNT_SAT(0),
 		.policy = {
@@ -153,6 +159,7 @@ struct test_case cases[] = {
 	{
 		.their_funds = AMOUNT_SAT(2500),
 		.available_funds = AMOUNT_SAT(3000),
+		.our_last_funds = NULL,
 		.channel_max = AMOUNT_SAT(11000),
 		.lease_request = AMOUNT_SAT(0),
 		.policy = {
@@ -175,6 +182,7 @@ struct test_case cases[] = {
 	{
 		.their_funds = AMOUNT_SAT(2500),
 		.available_funds = AMOUNT_SAT(5000),
+		.our_last_funds = NULL,
 		.channel_max = AMOUNT_SAT(11000),
 		.lease_request = AMOUNT_SAT(0),
 		.policy = {
@@ -197,6 +205,7 @@ struct test_case cases[] = {
 	{
 		.their_funds = AMOUNT_SAT(5000),
 		.available_funds = AMOUNT_SAT(5000),
+		.our_last_funds = NULL,
 		.channel_max = AMOUNT_SAT(11000),
 		.policy = {
 			.opt = FIXED,
@@ -220,6 +229,7 @@ struct test_case cases[] = {
 	{
 		.their_funds = AMOUNT_SAT(5000),
 		.available_funds = AMOUNT_SAT(5000),
+		.our_last_funds = NULL,
 		.channel_max = AMOUNT_SAT(5500),
 		.lease_request = AMOUNT_SAT(0),
 		.policy = {
@@ -242,6 +252,7 @@ struct test_case cases[] = {
 	{
 		.their_funds = AMOUNT_SAT(5000),
 		.available_funds = AMOUNT_SAT(500),
+		.our_last_funds = NULL,
 		.channel_max = AMOUNT_SAT(10000),
 		.lease_request = AMOUNT_SAT(0),
 		.policy = {
@@ -264,6 +275,7 @@ struct test_case cases[] = {
 	{
 		.their_funds = AMOUNT_SAT(5000),
 		.available_funds = AMOUNT_SAT(1000),
+		.our_last_funds = NULL,
 		.channel_max = AMOUNT_SAT(10000),
 		.lease_request = AMOUNT_SAT(0),
 		.policy = {
@@ -286,6 +298,7 @@ struct test_case cases[] = {
 	{
 		.their_funds = AMOUNT_SAT(5001),
 		.available_funds = AMOUNT_SAT(5000),
+		.our_last_funds = NULL,
 		.channel_max = AMOUNT_SAT(10000),
 		.lease_request = AMOUNT_SAT(0),
 		.policy = {
@@ -308,6 +321,7 @@ struct test_case cases[] = {
 	{
 		.their_funds = AMOUNT_SAT(5000),
 		.available_funds = AMOUNT_SAT(1000),
+		.our_last_funds = NULL,
 		.channel_max = AMOUNT_SAT(10000),
 		.lease_request = AMOUNT_SAT(0),
 		.policy = {
@@ -330,6 +344,7 @@ struct test_case cases[] = {
 	{
 		.their_funds = AMOUNT_SAT(5000),
 		.available_funds = AMOUNT_SAT(999),
+		.our_last_funds = NULL,
 		.channel_max = AMOUNT_SAT(10000),
 		.lease_request = AMOUNT_SAT(0),
 		.policy = {
@@ -352,6 +367,7 @@ struct test_case cases[] = {
 	{
 		.their_funds = AMOUNT_SAT(5000),
 		.available_funds = AMOUNT_SAT(5000),
+		.our_last_funds = NULL,
 		.channel_max = AMOUNT_SAT(5000),
 		.lease_request = AMOUNT_SAT(0),
 		.policy = {
@@ -374,6 +390,7 @@ struct test_case cases[] = {
 	{
 		.their_funds = AMOUNT_SAT(5000),
 		.available_funds = AMOUNT_SAT(5000),
+		.our_last_funds = NULL,
 		.channel_max = AMOUNT_SAT(11000),
 		.lease_request = AMOUNT_SAT(0),
 		.policy = {
@@ -396,6 +413,7 @@ struct test_case cases[] = {
 	{
 		.their_funds = AMOUNT_SAT(5000),
 		.available_funds = AMOUNT_SAT(100000),
+		.our_last_funds = NULL,
 		.channel_max = AMOUNT_SAT(11000),
 		.lease_request = AMOUNT_SAT(980),
 		.policy = {
@@ -418,6 +436,7 @@ struct test_case cases[] = {
 	{
 		.their_funds = AMOUNT_SAT(5000),
 		.available_funds = AMOUNT_SAT(100000),
+		.our_last_funds = NULL,
 		.channel_max = AMOUNT_SAT(11000),
 		.lease_request = AMOUNT_SAT(0),
 		.policy = {
@@ -451,6 +470,7 @@ static void check_fuzzing(struct test_case fuzzcase)
 	for (size_t i = 0; i < 100; i++) {
 		calculate_our_funding(&fuzzcase.policy, id,
 				      fuzzcase.their_funds,
+				      fuzzcase.our_last_funds,
 				      fuzzcase.available_funds,
 				      fuzzcase.channel_max,
 				      fuzzcase.lease_request,
@@ -484,6 +504,7 @@ int main(int argc, const char *argv[])
 
 	err = calculate_our_funding(policy, id,
 				    AMOUNT_SAT(50000),
+				    NULL,
 				    AMOUNT_SAT(50000),
 				    AMOUNT_SAT(100000),
 				    AMOUNT_SAT(100000),
@@ -494,6 +515,7 @@ int main(int argc, const char *argv[])
 	for (i = 0; i < ARRAY_SIZE(cases); i++) {
 		err = calculate_our_funding(&cases[i].policy, id,
 					    cases[i].their_funds,
+					    cases[i].our_last_funds,
 					    cases[i].available_funds,
 					    cases[i].channel_max,
 					    cases[i].lease_request,
@@ -528,6 +550,7 @@ int main(int argc, const char *argv[])
 	for (i = 0; i < 100 * flips; i++) {
 		calculate_our_funding(&flipcase.policy, id,
 				      flipcase.their_funds,
+				      flipcase.our_last_funds,
 				      flipcase.available_funds,
 				      flipcase.channel_max,
 				      flipcase.lease_request,