proto_to_locktime: abs and relative locktime handlers.

Our current proto_to_locktime actually handles relative locktimes,
and HTLCs use absolute.  Fix that.

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

commit_tx.c

@@ -35,7 +35,7 @@ struct bitcoin_tx *create_commit_tx(const tal_t *ctx,
 	if (!proto_to_pubkey(theirs->final_key, &theirkey))
 		return tal_free(tx);
 
-	if (!proto_to_locktime(theirs->delay, &locktime))
+	if (!proto_to_rel_locktime(theirs->delay, &locktime))
 		return tal_free(tx);
 
 	/* First output is a P2SH to a complex redeem script (usu. for me) */

protobuf_convert.c

@@ -81,13 +81,19 @@ void proto_to_sha256(const Sha256Hash *pb, struct sha256 *hash)
 	memcpy(hash->u.u8 + 24, &pb->d, 8);
 }
 
-bool proto_to_locktime(const Locktime *l, uint32_t *locktime)
+static bool proto_to_locktime(const Locktime *l, uint32_t off,
+			      uint32_t *locktime)
 {
 	switch (l->locktime_case) {
 	case LOCKTIME__LOCKTIME_SECONDS:
-		*locktime = 500000000 + l->seconds;
+		*locktime = off + l->seconds;
+		/* Check for wrap, or too low value */
+		if (*locktime < 500000000)
+			return false;
 		break;
 	case LOCKTIME__LOCKTIME_BLOCKS:
+		if (l->blocks >= 500000000)
+			return false;
 		*locktime = l->blocks;
 		break;
 	default:
@@ -95,3 +101,13 @@ bool proto_to_locktime(const Locktime *l, uint32_t *locktime)
 	}
 	return true;
 }
+
+bool proto_to_rel_locktime(const Locktime *l, uint32_t *locktime)
+{
+	return proto_to_locktime(l, 500000000, locktime);
+}
+
+bool proto_to_abs_locktime(const Locktime *l, uint32_t *locktime)
+{
+	return proto_to_locktime(l, 0, locktime);
+}

protobuf_convert.h

@@ -19,5 +19,6 @@ struct sha256;
 Sha256Hash *sha256_to_proto(const tal_t *ctx, const struct sha256 *hash);
 void proto_to_sha256(const Sha256Hash *pb, struct sha256 *hash);
 
-bool proto_to_locktime(const Locktime *l, uint32_t *locktime);
+bool proto_to_rel_locktime(const Locktime *l, uint32_t *locktime);
+bool proto_to_abs_locktime(const Locktime *l, uint32_t *locktime);
 #endif /* LIGHTNING_PROTOBUF_CONVERT_H */

test-cli/create-commit-spend-tx.c

@@ -60,7 +60,7 @@ int main(int argc, char *argv[])
 	o1 = pkt_from_file(argv[2], PKT__PKT_OPEN)->open;
 	o2 = pkt_from_file(argv[3], PKT__PKT_OPEN)->open;
 	a = pkt_from_file(argv[4], PKT__PKT_OPEN_ANCHOR)->open_anchor;
-	if (!proto_to_locktime(o2->delay, &locktime))
+	if (!proto_to_rel_locktime(o2->delay, &locktime))
 		errx(1, "Invalid locktime in o2");
 
  	/* We need our private key to spend commit output. */

test-cli/create-steal-tx.c

@@ -66,7 +66,7 @@ int main(int argc, char *argv[])
 
 	o1 = pkt_from_file(argv[4], PKT__PKT_OPEN)->open;
 	o2 = pkt_from_file(argv[5], PKT__PKT_OPEN)->open;
-	if (!proto_to_locktime(o1->delay, &locktime_seconds))
+	if (!proto_to_rel_locktime(o1->delay, &locktime_seconds))
 		errx(1, "Invalid locktime in o2");
 
 	if (!pubkey_from_hexstr(argv[6], &outpubkey))