close-channel / create-close-tx: take into account updates.

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

close-channel.c

@@ -34,6 +34,8 @@ int main(int argc, char *argv[])
 	bool testnet, complete = false;
 	struct pubkey pubkey1, pubkey2;
 	u8 *redeemscript;
+	int64_t delta;
+	size_t i;
 
 	err_set_progname(argv[0]);
 
@@ -41,14 +43,14 @@ int main(int argc, char *argv[])
 	opt_register_noarg("--complete", opt_set_bool, &complete,
 			   "Create a close_transaction_complete msg instead");
 	opt_register_noarg("--help|-h", opt_usage_and_exit,
-			   "<anchor-tx> <open-channel-file1> <open-channel-file2> <commit-privkey>\n"
+			   "<anchor-tx> <open-channel-file1> <open-channel-file2> <commit-privkey> [update-protobuf]...\n"
 			   "Create the signature needed for the close transaction",
 			   "Print this message.");
 
  	opt_parse(&argc, argv, opt_log_stderr_exit);
 
-	if (argc != 5)
-		opt_usage_exit_fail("Expected 4 arguments");
+	if (argc < 5)
+		opt_usage_exit_fail("Expected 4+ arguments");
 
 	anchor = bitcoin_tx_from_file(ctx, argv[1]);
 	o1 = pkt_from_file(argv[2], PKT__PKT_OPEN)->open;
@@ -62,6 +64,13 @@ int main(int argc, char *argv[])
 
 	bitcoin_txid(anchor, &anchor_txid);
 
+	/* Get delta by accumulting all the updates. */
+	delta = 0;
+	for (i = 5; i < argc; i++) {
+		Update *u = pkt_from_file(argv[i], PKT__PKT_UPDATE)->update;
+		delta += u->delta;
+	}
+
 	/* Get pubkeys */
 	if (!proto_to_pubkey(o1->anchor->pubkey, &pubkey2))
 		errx(1, "Invalid o1 commit pubkey");
@@ -75,7 +84,9 @@ int main(int argc, char *argv[])
 	redeemscript = bitcoin_redeem_2of2(ctx, &pubkey1, &pubkey2);
 
 	/* Now create the close tx to spend 2/2 output of anchor. */
-	close_tx = create_close_tx(ctx, o1, o2, &anchor_txid,
+	/* Assumes that updates are all from closer -> closee */
+	close_tx = create_close_tx(ctx, o1, o2, complete ? -delta : delta,
+				   &anchor_txid,
 				   find_p2sh_out(anchor, redeemscript));
 
 	/* Sign it for them. */

close_tx.c

@@ -9,6 +9,7 @@
 struct bitcoin_tx *create_close_tx(const tal_t *ctx,
 				   OpenChannel *ours,
 				   OpenChannel *theirs,
+				   int64_t delta,
 				   const struct sha256_double *anchor_txid,
 				   unsigned int anchor_output)
 {
@@ -30,16 +31,22 @@ struct bitcoin_tx *create_close_tx(const tal_t *ctx,
 	if (!proto_to_pubkey(theirs->final, &theirkey))
 		return tal_free(tx);
 
+	/* delta must make sense. */
+	if (delta < 0 && ours->anchor->total - ours->commitment_fee < -delta)
+			return tal_free(tx);
+	if (delta > 0 && theirs->anchor->total - theirs->commitment_fee < delta)
+			return tal_free(tx);
+
 	proto_to_sha256(ours->revocation_hash, &redeem);
 
 	/* One output is to us. */
-	tx->output[0].amount = ours->anchor->total - ours->commitment_fee;
+	tx->output[0].amount = ours->anchor->total - ours->commitment_fee + delta;
 	redeemscript = bitcoin_redeem_single(tx, &ourkey);
 	tx->output[0].script = scriptpubkey_p2sh(tx, redeemscript);
 	tx->output[0].script_length = tal_count(tx->output[0].script);
 
 	/* Other output is to them. */
-	tx->output[1].amount = theirs->anchor->total - theirs->commitment_fee;
+	tx->output[1].amount = theirs->anchor->total - theirs->commitment_fee - delta;
 	redeemscript = bitcoin_redeem_single(tx, &theirkey);
 	tx->output[1].script = scriptpubkey_p2sh(tx, redeemscript);
 	tx->output[1].script_length = tal_count(tx->output[1].script);

close_tx.h

@@ -10,6 +10,7 @@ struct sha256_double;
 struct bitcoin_tx *create_close_tx(const tal_t *ctx,
 				   OpenChannel *ours,
 				   OpenChannel *theirs,
+				   int64_t delta,
 				   const struct sha256_double *anchor_txid,
 				   unsigned int anchor_output);
 #endif

create-close-tx.c

@@ -33,19 +33,21 @@ int main(int argc, char *argv[])
 	char *tx_hex;
 	CloseChannel *close;
 	CloseChannelComplete *closecomplete;
+	size_t i;
+	int64_t delta;
 
 	err_set_progname(argv[0]);
 
 	/* FIXME: Take update.pbs to adjust channel */
 	opt_register_noarg("--help|-h", opt_usage_and_exit,
-			   "<anchor-tx> <open-channel-file1> <open-channel-file2> <close-protobuf> <close-complete-protobuf>\n"
+			   "<anchor-tx> <open-channel-file1> <open-channel-file2> <close-protobuf> <close-complete-protobuf> [update-protobuf]...\n"
 			   "Create the close transaction from the signatures",
 			   "Print this message.");
 
  	opt_parse(&argc, argv, opt_log_stderr_exit);
 
-	if (argc != 6)
-		opt_usage_exit_fail("Expected 5 arguments");
+	if (argc < 6)
+		opt_usage_exit_fail("Expected 5+ arguments");
 
 	anchor = bitcoin_tx_from_file(ctx, argv[1]);
 	o1 = pkt_from_file(argv[2], PKT__PKT_OPEN)->open;
@@ -61,11 +63,18 @@ int main(int argc, char *argv[])
 	if (!proto_to_pubkey(o2->anchor->pubkey, &pubkey2))
 		errx(1, "Invalid anchor-2 key");
 	
+	/* Get delta by accumulting all the updates. */
+	delta = 0;
+	for (i = 6; i < argc; i++) {
+		Update *u = pkt_from_file(argv[i], PKT__PKT_UPDATE)->update;
+		delta += u->delta;
+	}	
+
 	/* This is what the anchor pays to; figure out which output. */
 	redeemscript = bitcoin_redeem_2of2(ctx, &pubkey1, &pubkey2);
 
 	/* Now create the close tx to spend 2/2 output of anchor. */
-	close_tx = create_close_tx(ctx, o1, o2, &anchor_txid,
+	close_tx = create_close_tx(ctx, o1, o2, delta, &anchor_txid,
 				   find_p2sh_out(anchor, redeemscript));
 
 	/* Signatures well-formed? */