opening: update to new open_channel with channel_flags.

While we're there, make the announcement conditional on it.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

lightningd/opening/opening.c

@@ -202,6 +202,7 @@ static u8 *funder_channel(struct state *state,
 			  const struct basepoints *ours,
 			  u32 max_minimum_depth,
 			  u64 change_satoshis, u32 change_keyindex,
+			  u8 channel_flags,
 			  const struct utxo *utxos,
 			  const u8 *bip32_seed)
 {
@@ -258,7 +259,8 @@ static u8 *funder_channel(struct state *state,
 				  &ours->revocation,
 				  &ours->payment,
 				  &ours->delayed_payment,
-				  &state->next_per_commit[LOCAL]);
+				  &state->next_per_commit[LOCAL],
+				  channel_flags);
 	if (!sync_crypto_write(&state->cs, PEER_FD, msg))
 		peer_failed(PEER_FD, &state->cs, NULL, WIRE_OPENING_PEER_WRITE_FAILED,
 			      "Writing open_channel");
@@ -468,6 +470,7 @@ static u8 *fundee_channel(struct state *state,
 	struct sha256_double chain_hash;
 	u8 *msg;
 	const u8 **wscripts;
+	u8 channel_flags;
 
 	state->remoteconf = tal(state, struct channel_config);
 
@@ -491,7 +494,8 @@ static u8 *fundee_channel(struct state *state,
 				   &theirs.revocation,
 				   &theirs.payment,
 				   &theirs.delayed_payment,
-				   &state->next_per_commit[REMOTE]))
+				   &state->next_per_commit[REMOTE],
+				   &channel_flags))
 		peer_failed(PEER_FD, &state->cs, NULL, WIRE_OPENING_PEER_BAD_INITIAL_MESSAGE,
 			      "Parsing open_channel %s",
 			      tal_hex(peer_msg, peer_msg));
@@ -666,6 +670,7 @@ static u8 *fundee_channel(struct state *state,
 					   state->funding_txout,
 					   state->funding_satoshis,
 					   state->push_msat,
+					   channel_flags,
 					   msg);
 }
 
@@ -681,6 +686,7 @@ int main(int argc, char *argv[])
 	u32 min_feerate, max_feerate;
 	u64 change_satoshis;
 	u32 change_keyindex;
+	u8 channel_flags;
 	struct utxo *utxos;
 	u8 *bip32_seed;
 
@@ -734,10 +740,11 @@ int main(int argc, char *argv[])
 				    &state->push_msat,
 				    &state->feerate_per_kw, &max_minimum_depth,
 				    &change_satoshis, &change_keyindex,
-				    &utxos, &bip32_seed))
+				    &channel_flags, &utxos, &bip32_seed))
 		msg = funder_channel(state, &our_funding_pubkey, &our_points,
 				     max_minimum_depth, change_satoshis,
-				     change_keyindex, utxos, bip32_seed);
+				     change_keyindex, channel_flags,
+				     utxos, bip32_seed);
 	else if (fromwire_opening_fundee(state, msg, NULL, &minimum_depth,
 					 &min_feerate, &max_feerate, &peer_msg))
 		msg = fundee_channel(state, &our_funding_pubkey, &our_points,

lightningd/opening/opening_wire.csv

@@ -31,6 +31,7 @@ opening_funder,,feerate_per_kw,4
 opening_funder,,max_minimum_depth,4
 opening_funder,,change_satoshis,u64
 opening_funder,,change_keyindex,u32
+opening_funder,,channel_flags,u8
 #include <lightningd/utxo.h>
 opening_funder,,num_inputs,u16
 opening_funder,,inputs,num_inputs*struct utxo
@@ -72,6 +73,7 @@ opening_fundee_reply,,funding_txid,struct sha256_double
 opening_fundee_reply,,funding_txout,u16
 opening_fundee_reply,,funding_satoshis,8
 opening_fundee_reply,,push_msat,8
+opening_fundee_reply,,channel_flags,u8
 # The (encrypted) funding signed message: send this and we're committed.
 opening_fundee_reply,,msglen,u16
 opening_fundee_reply,,funding_signed_msg,msglen*u8

lightningd/peer_control.c

@@ -37,7 +37,7 @@
 #include <unistd.h>
 #include <wally_bip32.h>
 #include <wire/gen_onion_wire.h>
-#include <wire/gen_peer_wire.h>
+#include <wire/peer_wire.h>
 #include <wire/wire_sync.h>
 
 static void destroy_peer(struct peer *peer)
@@ -793,6 +793,15 @@ static enum watch_result funding_lockin_cb(struct peer *peer,
 								 peer->scid)));
 	}
 
+	/* BOLT #7:
+	 *
+	 * If the `open_channel` message had the `announce_channel` bit set,
+	 * then both nodes must send the `announcement_signatures` message,
+	 * otherwise they MUST NOT.
+	 */
+	if (!(peer->channel_flags & CHANNEL_FLAGS_ANNOUNCE_CHANNEL))
+		return DELETE_WATCH;
+
 	/* BOLT #7:
 	 *
 	 * If sent, `announcement_signatures` messages MUST NOT be sent until
@@ -1338,6 +1347,7 @@ static bool opening_fundee_finished(struct subd *opening,
 					   &peer->funding_outnum,
 					   &peer->funding_satoshi,
 					   &peer->push_msat,
+					   &peer->channel_flags,
 					   &funding_signed)) {
 		log_broken(peer->log, "bad OPENING_FUNDEE_REPLY %s",
 			   tal_hex(reply, reply));
@@ -1524,6 +1534,8 @@ static bool gossip_peer_released(struct subd *gossip,
 		       &max_to_self_delay, &max_minimum_depth,
 		       &min_effective_htlc_capacity_msat);
 
+	fc->peer->channel_flags = OUR_CHANNEL_FLAGS;
+
 	fc->peer->seed = tal(fc->peer, struct privkey);
 	derive_peer_seed(ld, fc->peer->seed, &fc->peer->id);
 	msg = towire_opening_init(fc, &fc->peer->our_config,
@@ -1545,6 +1557,7 @@ static bool gossip_peer_released(struct subd *gossip,
 				    fc->peer->push_msat,
 				    15000, max_minimum_depth,
 				    fc->change, fc->change_keyindex,
+				    fc->peer->channel_flags,
 				    utxos, bip32_base);
 	subd_req(fc, opening, take(msg), -1, 2, opening_funder_finished, fc);
 	return true;

lightningd/peer_control.h

@@ -10,6 +10,7 @@
 #include <lightningd/channel_config.h>
 #include <lightningd/peer_state.h>
 #include <stdbool.h>
+#include <wire/peer_wire.h>
 
 #define ANNOUNCE_MIN_DEPTH 6
 
@@ -46,6 +47,9 @@ struct peer {
 	struct log_book *log_book;
 	struct log *log;
 
+	/* Channel flags from opening message. */
+	u8 channel_flags;
+
 	/* If we've disconnected, this is set. */
 	bool reconnected;
 
@@ -140,6 +144,9 @@ void add_peer(struct lightningd *ld, u64 unique_id,
 	      int fd, const struct pubkey *id,
 	      const struct crypto_state *cs);
 
+/* Could be configurable. */
+#define OUR_CHANNEL_FLAGS CHANNEL_FLAGS_ANNOUNCE_CHANNEL
+
 /* Peer has failed, but try reconnected. */
 PRINTF_FMT(2,3) void peer_fail_transient(struct peer *peer, const char *fmt,...);
 /* Peer has failed, give up on it. */

wire/gen_peer_wire_csv

@@ -31,6 +31,7 @@ open_channel,153,revocation_basepoint,33
 open_channel,186,payment_basepoint,33
 open_channel,219,delayed_payment_basepoint,33
 open_channel,252,first_per_commitment_point,33
+open_channel,285,channel_flags,1
 accept_channel,33
 accept_channel,0,temporary_channel_id,32
 accept_channel,32,dust_limit_satoshis,8

wire/peer_wire.h

@@ -19,6 +19,15 @@ bool is_unknown_msg_discardable(const u8 *cursor);
 /* Return true if it's a gossip message. */
 bool is_gossip_msg(const u8 *cursor);
 
+/* BOLT #2:
+ *
+ * Only the least-significant bit of `channel_flags` is currently
+ * defined: `announce_channel`.  This indicates whether the initiator
+ * of the funding flow wishes to advertise this channel publicly to
+ * the network as detailed within [BOLT #7]
+ */
+#define CHANNEL_FLAGS_ANNOUNCE_CHANNEL	1
+
 /* Compare two short_channel_ids and return true if they are the equal */
 bool short_channel_id_eq(const struct short_channel_id *a,
 			 const struct short_channel_id *b);

wire/test/run-peer-wire.c

@@ -180,6 +180,7 @@ struct msg_open_channel {
 	struct pubkey payment_basepoint;
 	struct pubkey delayed_payment_basepoint;
 	struct pubkey first_per_commitment_point;
+	u8 channel_flags;
 };
 struct msg_update_fail_htlc {
 	struct channel_id channel_id;
@@ -268,7 +269,8 @@ static void *towire_struct_open_channel(const tal_t *ctx,
 				   &s->revocation_basepoint,
 				   &s->payment_basepoint,
 				   &s->delayed_payment_basepoint,
-				   &s->first_per_commitment_point);
+				   &s->first_per_commitment_point,
+				   s->channel_flags);
 }
 
 static struct msg_open_channel *fromwire_struct_open_channel(const tal_t *ctx, const void *p, size_t *plen)
@@ -291,7 +293,8 @@ static struct msg_open_channel *fromwire_struct_open_channel(const tal_t *ctx, c
 				  &s->revocation_basepoint,
 				  &s->payment_basepoint,
 				  &s->delayed_payment_basepoint,
-				  &s->first_per_commitment_point))
+				  &s->first_per_commitment_point,
+				  &s->channel_flags))
 		return s;
 	return tal_free(s);
 }
@@ -788,7 +791,7 @@ static bool open_channel_eq(const struct msg_open_channel *a,
 			    const struct msg_open_channel *b)
 {
 	return eq_with(a, b, max_accepted_htlcs)
-		&& eq_between(a, b, funding_pubkey, first_per_commitment_point);
+		&& eq_between(a, b, funding_pubkey, channel_flags);
 }
 
 static bool channel_update_eq(const struct msg_channel_update *a,