closingd: add notifications for feerate ranges.

This allows cmdline users to have more idea what's going on.

Inspired-by: https://github.com/ElementsProject/lightning/issues/4777
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-Added: `close` now notifies about the feeranges each side uses.

closingd/closingd.c

@@ -32,6 +32,20 @@
 #define REQ_FD STDIN_FILENO
 #define HSM_FD 6
 
+static void notify(enum log_level level, const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	wire_sync_write(REQ_FD,
+			take(towire_closingd_notification(NULL,
+							  level,
+							  tal_vfmt(tmpctx, fmt,
+								   ap))));
+
+	va_end(ap);
+}
+
 static struct bitcoin_tx *close_tx(const tal_t *ctx,
 				   const struct chainparams *chainparams,
 				   struct per_peer_state *pps,
@@ -192,6 +206,10 @@ static void send_offer(struct per_peer_state *pps,
 		close_tlvs->fee_range
 			= cast_const(struct tlv_closing_signed_tlvs_fee_range *,
 				     tlv_fees);
+		notify(LOG_INFORM, "Sending closing fee offer %s, with range %s-%s",
+		       type_to_string(tmpctx, struct amount_sat, &fee_to_offer),
+		       type_to_string(tmpctx, struct amount_sat, &tlv_fees->min_fee_satoshis),
+		       type_to_string(tmpctx, struct amount_sat, &tlv_fees->max_fee_satoshis));
 	} else
 		close_tlvs = NULL;
 
@@ -345,10 +363,23 @@ receive_offer(struct per_peer_state *pps,
 		     type_to_string(tmpctx, struct amount_sat, &received_fee));
 
 	if (tlv_fees) {
-		if (close_tlvs)
+		if (close_tlvs) {
 			*tlv_fees = tal_steal(tlv_fees, close_tlvs->fee_range);
-		else
+		} else {
 			*tlv_fees = NULL;
+		}
+	}
+
+	if (close_tlvs && close_tlvs->fee_range) {
+		notify(LOG_INFORM, "Received closing fee offer %s, with range %s-%s",
+		       type_to_string(tmpctx, struct amount_sat, &received_fee),
+		       type_to_string(tmpctx, struct amount_sat,
+				      &close_tlvs->fee_range->min_fee_satoshis),
+		       type_to_string(tmpctx, struct amount_sat,
+				      &close_tlvs->fee_range->max_fee_satoshis));
+	} else {
+		notify(LOG_INFORM, "Received closing fee offer %s, without range",
+		       type_to_string(tmpctx, struct amount_sat, &received_fee));
 	}
 
 	/* Master sorts out what is best offer, we just tell it any above min */
@@ -1080,4 +1111,5 @@ exit_thru_the_giftshop:
 	daemon_shutdown();
 
 	return 0;
+
 }

closingd/closingd_wire.csv

@@ -3,6 +3,7 @@
 #include <common/cryptomsg.h>
 #include <common/htlc_wire.h>
 #include <common/per_peer_state.h>
+#include <common/status_wire.h>
 # Begin!  (passes peer fd, gossipd-client fd)
 msgtype,closingd_init,2001
 msgdata,closingd_init,chainparams,chainparams,
@@ -31,6 +32,11 @@ msgdata,closingd_init,use_quickclose,bool,
 msgdata,closingd_init,dev_fast_gossip,bool,
 msgdata,closingd_init,shutdown_wrong_funding,?bitcoin_outpoint,
 
+# Message for any commands waiting.
+msgtype,closingd_notification,2003
+msgdata,closingd_notification,level,enum log_level,
+msgdata,closingd_notification,message,wirestring,
+
 # We received an offer, save signature.
 msgtype,closingd_received_signature,2002
 msgdata,closingd_received_signature,signature,bitcoin_signature,

closingd/closingd_wiregen.c

@@ -21,6 +21,7 @@ const char *closingd_wire_name(int e)
 
 	switch ((enum closingd_wire)e) {
 	case WIRE_CLOSINGD_INIT: return "WIRE_CLOSINGD_INIT";
+	case WIRE_CLOSINGD_NOTIFICATION: return "WIRE_CLOSINGD_NOTIFICATION";
 	case WIRE_CLOSINGD_RECEIVED_SIGNATURE: return "WIRE_CLOSINGD_RECEIVED_SIGNATURE";
 	case WIRE_CLOSINGD_RECEIVED_SIGNATURE_REPLY: return "WIRE_CLOSINGD_RECEIVED_SIGNATURE_REPLY";
 	case WIRE_CLOSINGD_COMPLETE: return "WIRE_CLOSINGD_COMPLETE";
@@ -34,6 +35,7 @@ bool closingd_wire_is_defined(u16 type)
 {
 	switch ((enum closingd_wire)type) {
 	case WIRE_CLOSINGD_INIT:;
+	case WIRE_CLOSINGD_NOTIFICATION:;
 	case WIRE_CLOSINGD_RECEIVED_SIGNATURE:;
 	case WIRE_CLOSINGD_RECEIVED_SIGNATURE_REPLY:;
 	case WIRE_CLOSINGD_COMPLETE:;
@@ -145,6 +147,30 @@ bool fromwire_closingd_init(const tal_t *ctx, const void *p, const struct chainp
 	return cursor != NULL;
 }
 
+/* WIRE: CLOSINGD_NOTIFICATION */
+/* Message for any commands waiting. */
+u8 *towire_closingd_notification(const tal_t *ctx, enum log_level level, const wirestring *message)
+{
+	u8 *p = tal_arr(ctx, u8, 0);
+
+	towire_u16(&p, WIRE_CLOSINGD_NOTIFICATION);
+	towire_log_level(&p, level);
+	towire_wirestring(&p, message);
+
+	return memcheck(p, tal_count(p));
+}
+bool fromwire_closingd_notification(const tal_t *ctx, const void *p, enum log_level *level, wirestring **message)
+{
+	const u8 *cursor = p;
+	size_t plen = tal_count(p);
+
+	if (fromwire_u16(&cursor, &plen) != WIRE_CLOSINGD_NOTIFICATION)
+		return false;
+ 	*level = fromwire_log_level(&cursor, &plen);
+ 	*message = fromwire_wirestring(ctx, &cursor, &plen);
+	return cursor != NULL;
+}
+
 /* WIRE: CLOSINGD_RECEIVED_SIGNATURE */
 /* We received an offer */
 u8 *towire_closingd_received_signature(const tal_t *ctx, const struct bitcoin_signature *signature, const struct bitcoin_tx *tx)
@@ -209,4 +235,4 @@ bool fromwire_closingd_complete(const void *p)
 		return false;
 	return cursor != NULL;
 }
-// SHA256STAMP:0d0d56c4ec5230461ead5cfac728e57e75db7bff1b53b1b0aaef20b82ce76362
+// SHA256STAMP:0602a002b81e43b45a8c40a15cb4af6c5e7ea66d6f95b7ba89f386b2fe73bd0e

closingd/closingd_wiregen.h

@@ -12,10 +12,13 @@
 #include <common/cryptomsg.h>
 #include <common/htlc_wire.h>
 #include <common/per_peer_state.h>
+#include <common/status_wire.h>
 
 enum closingd_wire {
         /*  Begin!  (passes peer fd */
         WIRE_CLOSINGD_INIT = 2001,
+        /*  Message for any commands waiting. */
+        WIRE_CLOSINGD_NOTIFICATION = 2003,
         /*  We received an offer */
         WIRE_CLOSINGD_RECEIVED_SIGNATURE = 2002,
         WIRE_CLOSINGD_RECEIVED_SIGNATURE_REPLY = 2102,
@@ -40,6 +43,11 @@ bool closingd_wire_is_defined(u16 type);
 u8 *towire_closingd_init(const tal_t *ctx, const struct chainparams *chainparams, const struct per_peer_state *pps, const struct channel_id *channel_id, const struct bitcoin_txid *funding_txid, u16 funding_txout, struct amount_sat funding_satoshi, const struct pubkey *local_fundingkey, const struct pubkey *remote_fundingkey, enum side opener, struct amount_sat local_sat, struct amount_sat remote_sat, struct amount_sat our_dust_limit, u32 min_feerate_perksipa, u32 preferred_feerate_perksipa, u32 *max_feerate_perksipa, struct amount_sat fee_limit_satoshi, const u8 *local_scriptpubkey, const u8 *remote_scriptpubkey, u64 fee_negotiation_step, u8 fee_negotiation_step_unit, bool use_quickclose, bool dev_fast_gossip, const struct bitcoin_outpoint *shutdown_wrong_funding);
 bool fromwire_closingd_init(const tal_t *ctx, const void *p, const struct chainparams **chainparams, struct per_peer_state **pps, struct channel_id *channel_id, struct bitcoin_txid *funding_txid, u16 *funding_txout, struct amount_sat *funding_satoshi, struct pubkey *local_fundingkey, struct pubkey *remote_fundingkey, enum side *opener, struct amount_sat *local_sat, struct amount_sat *remote_sat, struct amount_sat *our_dust_limit, u32 *min_feerate_perksipa, u32 *preferred_feerate_perksipa, u32 **max_feerate_perksipa, struct amount_sat *fee_limit_satoshi, u8 **local_scriptpubkey, u8 **remote_scriptpubkey, u64 *fee_negotiation_step, u8 *fee_negotiation_step_unit, bool *use_quickclose, bool *dev_fast_gossip, struct bitcoin_outpoint **shutdown_wrong_funding);
 
+/* WIRE: CLOSINGD_NOTIFICATION */
+/*  Message for any commands waiting. */
+u8 *towire_closingd_notification(const tal_t *ctx, enum log_level level, const wirestring *message);
+bool fromwire_closingd_notification(const tal_t *ctx, const void *p, enum log_level *level, wirestring **message);
+
 /* WIRE: CLOSINGD_RECEIVED_SIGNATURE */
 /*  We received an offer */
 u8 *towire_closingd_received_signature(const tal_t *ctx, const struct bitcoin_signature *signature, const struct bitcoin_tx *tx);
@@ -56,4 +64,4 @@ bool fromwire_closingd_complete(const void *p);
 
 
 #endif /* LIGHTNING_CLOSINGD_CLOSINGD_WIREGEN_H */
-// SHA256STAMP:0d0d56c4ec5230461ead5cfac728e57e75db7bff1b53b1b0aaef20b82ce76362
+// SHA256STAMP:0602a002b81e43b45a8c40a15cb4af6c5e7ea66d6f95b7ba89f386b2fe73bd0e

lightningd/closing_control.c

@@ -283,6 +283,25 @@ static void peer_closing_complete(struct channel *channel, const u8 *msg)
 			  "Closing complete");
 }
 
+static void peer_closing_notify(struct channel *channel, const u8 *msg)
+{
+	char *message;
+	struct close_command *i;
+	enum log_level level;
+
+	if (!fromwire_closingd_notification(msg, msg, &level, &message)) {
+		channel_internal_error(channel, "Bad closing_notify %s",
+				       tal_hex(msg, msg));
+		return;
+	}
+
+	list_for_each(&channel->peer->ld->close_commands, i, list) {
+		if (i->channel != channel)
+			continue;
+		json_notify_fmt(i->cmd, level, "%s", message);
+	}
+}
+
 static unsigned closing_msg(struct subd *sd, const u8 *msg, const int *fds UNUSED)
 {
 	enum closingd_wire t = fromwire_peektype(msg);
@@ -296,6 +315,10 @@ static unsigned closing_msg(struct subd *sd, const u8 *msg, const int *fds UNUSE
 		peer_closing_complete(sd->channel, msg);
 		break;
 
+	case WIRE_CLOSINGD_NOTIFICATION:
+		peer_closing_notify(sd->channel, msg);
+		break;
+
 	/* We send these, not receive them */
 	case WIRE_CLOSINGD_INIT:
 	case WIRE_CLOSINGD_RECEIVED_SIGNATURE_REPLY:

tests/test_closing.py

@@ -3318,8 +3318,14 @@ def test_close_feerate_range(node_factory, bitcoind, chainparams):
     """Test the quick-close fee range negotiation"""
     l1, l2 = node_factory.line_graph(2)
 
+    notifications = []
+
+    def save_notifications(message, progress, request, **kwargs):
+        notifications.append(message)
+
     # Lowball the range here.
-    l1.rpc.close(l2.info['id'], feerange=['253perkw', 'normal'])
+    with l1.rpc.notify(save_notifications):
+        l1.rpc.close(l2.info['id'], feerange=['253perkw', 'normal'])
 
     if not chainparams['elements']:
         l1_range = [138, 4110]
@@ -3335,6 +3341,16 @@ def test_close_feerate_range(node_factory, bitcoind, chainparams):
     overlap = [max(l1_range[0], l2_range[0]), min(l1_range[1], l2_range[1])]
     l1.daemon.wait_for_log('performing quickclose in range {}sat-{}sat'.format(overlap[0], overlap[1]))
 
+    log = l1.daemon.is_in_log('Their actual closing tx fee is .*sat')
+    rate = re.match('.*Their actual closing tx fee is ([0-9]*sat).*', log).group(1)
+
+    assert notifications == ['Sending closing fee offer {}, with range {}sat-{}sat'.format(rate,
+                                                                                           l1_range[0],
+                                                                                           l1_range[1]),
+                             'Received closing fee offer {}, with range {}sat-{}sat'.format(rate,
+                                                                                            l2_range[0],
+                                                                                            l2_range[1])]
+
 
 def test_close_twice(node_factory, executor):
     # First feerate is too low, second fixes it.