From 9a0d2040d34d20722accaa5daf20e5c907922eb9 Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Wed, 9 Nov 2022 13:02:00 +1030
Subject: [PATCH] common/features: add explicit bolt12 feature sets.

The spec only specifies the mpp bit for invoices, but in
general they are separate spaces.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 common/bolt12.c          | 7 +++++--
 common/features.c        | 3 ++-
 common/features.h        | 5 ++++-
 lightningd/options.c     | 4 ++--
 tests/test_connection.py | 2 +-
 5 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/common/bolt12.c b/common/bolt12.c
index a43fcee83bb6..192ecdaec3bf 100644
--- a/common/bolt12.c
+++ b/common/bolt12.c
@@ -53,6 +53,7 @@ static char *check_features_and_chain(const tal_t *ctx,
 				      const struct feature_set *our_features,
 				      const struct chainparams *must_be_chain,
 				      const u8 *features,
+				      enum feature_place fplace,
 				      const struct bitcoin_blkid *chains,
 				      size_t num_chains)
 {
@@ -62,8 +63,7 @@ static char *check_features_and_chain(const tal_t *ctx,
 	}
 
 	if (our_features) {
-		int badf = features_unsupported(our_features, features,
-						BOLT11_FEATURE);
+		int badf = features_unsupported(our_features, features, fplace);
 		if (badf != -1)
 			return tal_fmt(ctx, "unknown feature bit %i", badf);
 	}
@@ -182,6 +182,7 @@ struct tlv_offer *offer_decode(const tal_t *ctx,
 	*fail = check_features_and_chain(ctx,
 					 our_features, must_be_chain,
 					 offer->features,
+					 BOLT12_OFFER_FEATURE,
 					 offer->chains,
 					 tal_count(offer->chains));
 	if (*fail)
@@ -236,6 +237,7 @@ struct tlv_invoice_request *invrequest_decode(const tal_t *ctx,
 	*fail = check_features_and_chain(ctx,
 					 our_features, must_be_chain,
 					 invrequest->features,
+					 BOLT12_INVREQ_FEATURE,
 					 invrequest->chain, 1);
 	if (*fail)
 		return tal_free(invrequest);
@@ -276,6 +278,7 @@ struct tlv_invoice *invoice_decode_nosig(const tal_t *ctx,
 	*fail = check_features_and_chain(ctx,
 					 our_features, must_be_chain,
 					 invoice->features,
+					 BOLT12_INVOICE_FEATURE,
 					 invoice->chain, 1);
 	if (*fail)
 		return tal_free(invoice);
diff --git a/common/features.c b/common/features.c
index 1295cf3dcaa3..2a090f1e80f9 100644
--- a/common/features.c
+++ b/common/features.c
@@ -59,7 +59,8 @@ static const struct feature_style feature_styles[] = {
 	{ OPT_BASIC_MPP,
 	  .copy_style = { [INIT_FEATURE] = FEATURE_REPRESENT,
 			  [NODE_ANNOUNCE_FEATURE] = FEATURE_REPRESENT,
-			  [BOLT11_FEATURE] = FEATURE_REPRESENT } },
+			  [BOLT11_FEATURE] = FEATURE_REPRESENT,
+			  [BOLT12_INVOICE_FEATURE] = FEATURE_REPRESENT } },
 	/* BOLT #9:
 	 * | 18/19 | `option_support_large_channel` |... IN ...
 	 */
diff --git a/common/features.h b/common/features.h
index 02c58d6f2bad..a862bafe1c53 100644
--- a/common/features.h
+++ b/common/features.h
@@ -10,8 +10,11 @@ enum feature_place {
 	NODE_ANNOUNCE_FEATURE,
 	CHANNEL_FEATURE,
 	BOLT11_FEATURE,
+	BOLT12_OFFER_FEATURE,
+	BOLT12_INVREQ_FEATURE,
+	BOLT12_INVOICE_FEATURE,
 };
-#define NUM_FEATURE_PLACE (BOLT11_FEATURE+1)
+#define NUM_FEATURE_PLACE (BOLT12_INVOICE_FEATURE+1)
 
 extern const char *feature_place_names[NUM_FEATURE_PLACE];
 
diff --git a/lightningd/options.c b/lightningd/options.c
index 07504bda942a..501fef5bed3b 100644
--- a/lightningd/options.c
+++ b/lightningd/options.c
@@ -635,8 +635,8 @@ static char *opt_force_featureset(const char *optarg,
 	char **parts = tal_strsplit(tmpctx, optarg, "/", STR_EMPTY_OK);
 	if (tal_count(parts) != NUM_FEATURE_PLACE + 1) {
 		if (!strstarts(optarg, "-") && !strstarts(optarg, "+"))
-			return "Expected 5 feature sets (init/globalinit/"
-			       " node_announce/channel/bolt11) each terminated by /"
+			return "Expected 8 feature sets (init/globalinit/"
+			       " node_announce/channel/bolt11/b12offer/b12invreq/b12inv) each terminated by /"
 			       " OR +/-<single_bit_num>";
 
 		char *endp;
diff --git a/tests/test_connection.py b/tests/test_connection.py
index a0860386eaaa..3521c9180f40 100644
--- a/tests/test_connection.py
+++ b/tests/test_connection.py
@@ -3510,7 +3510,7 @@ def test_nonstatic_channel(node_factory, bitcoind):
                                      opts=[{},
                                            # needs at least 15 to connect
                                            # (and 9 is a dependent)
-                                           {'dev-force-features': '9,15/////'}])
+                                           {'dev-force-features': '9,15////////'}])
     chan = only_one(only_one(l1.rpc.listpeers()['peers'])['channels'])
     assert 'option_static_remotekey' not in chan['features']
     assert 'option_anchor_outputs' not in chan['features']