channeld: send commit tx and signature to master.

This also means we can simply drop it to chain on error.

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

lightningd/channel/channel.c

@@ -742,7 +742,8 @@ static u8 *got_commitsig_msg(const tal_t *ctx,
 			     u64 local_commit_index,
 			     const secp256k1_ecdsa_signature *commit_sig,
 			     const secp256k1_ecdsa_signature *htlc_sigs,
-			     const struct htlc **changed_htlcs)
+			     const struct htlc **changed_htlcs,
+			     const struct bitcoin_tx *committx)
 {
 	const tal_t *tmpctx = tal_tmpctx(ctx);
 	struct changed_htlc *changed;
@@ -803,7 +804,8 @@ static u8 *got_commitsig_msg(const tal_t *ctx,
 					   shared_secret,
 					   fulfilled,
 					   failed,
-					   changed);
+					   changed,
+					   committx);
 	tal_free(tmpctx);
 	return msg;
 }
@@ -929,7 +931,7 @@ static struct io_plan *handle_peer_commit_sig(struct io_conn *conn,
 
 	/* Tell master daemon, then wait for ack. */
 	msg = got_commitsig_msg(tmpctx, peer->next_index[LOCAL], &commit_sig,
-				htlc_sigs, changed_htlcs);
+				htlc_sigs, changed_htlcs, txs[0]);
 
 	master_sync_reply(peer, take(msg),
 			  WIRE_CHANNEL_GOT_COMMITSIG_REPLY,

lightningd/channel/channel_wire.csv

@@ -155,6 +155,7 @@ channel_got_commitsig,,failed,num_failed*struct failed_htlc
 # RCVD_ADD_ACK_COMMIT, RCVD_REMOVE_ACK_COMMIT
 channel_got_commitsig,,num_changed,u16
 channel_got_commitsig,,changed,num_changed*struct changed_htlc
+channel_got_commitsig,,tx,struct bitcoin_tx
 
 # Wait for reply, to make sure it's on disk before we send revocation.
 channel_got_commitsig_reply,121

lightningd/peer_control.c

@@ -103,12 +103,6 @@ static void drop_to_chain(struct peer *peer)
 	struct secrets secrets;
 	secp256k1_ecdsa_signature sig;
 
-	/* FIXME: Implement. */
-	if (peer->state != CLOSINGD_SIGEXCHANGE) {
-		tal_free(tmpctx);
-		return;
-	}
-
 	derive_basepoints(peer->seed, &local_funding_pubkey, NULL, &secrets,
 			  NULL);
 

lightningd/peer_htlcs.c

@@ -1,3 +1,4 @@
+#include <bitcoin/tx.h>
 #include <ccan/build_assert/build_assert.h>
 #include <ccan/mem/mem.h>
 #include <ccan/tal/str/str.h>
@@ -1003,6 +1004,7 @@ int peer_got_commitsig(struct peer *peer, const u8 *msg)
 	struct fulfilled_htlc *fulfilled;
 	struct failed_htlc *failed;
 	struct changed_htlc *changed;
+	struct bitcoin_tx *tx = tal(msg, struct bitcoin_tx);
 	size_t i;
 
 	if (!fromwire_channel_got_commitsig(msg, msg, NULL,
@@ -1013,7 +1015,8 @@ int peer_got_commitsig(struct peer *peer, const u8 *msg)
 					    &shared_secrets,
 					    &fulfilled,
 					    &failed,
-					    &changed)) {
+					    &changed,
+					    tx)) {
 		peer_internal_error(peer,
 				    "bad fromwire_channel_got_commitsig %s",
 				    tal_hex(peer, msg));
@@ -1059,6 +1062,8 @@ int peer_got_commitsig(struct peer *peer, const u8 *msg)
 	if (!peer_save_commitsig_received(peer, commitnum))
 		return -1;
 
+	peer_last_tx(peer, tx, &commit_sig);
+
 	/* Tell it we've committed, and to go ahead with revoke. */
 	msg = towire_channel_got_commitsig_reply(msg);
 	subd_send_msg(peer->owner, take(msg));