protocol: rename locktime fields to "delay" and "expiry"

For open transactions, locktime is a delay we require on the other
side's to-self commit transaction outputs to ensure we can cut them
off if necessary.

For HTLCs, it's an absolute expiry time.

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->locktime, &locktime))
+	if (!proto_to_locktime(theirs->delay, &locktime))
 		return tal_free(tx);
 
 	/* First output is a P2SH to a complex redeem script (usu. for me) */

lightning.pb-c.c

@@ -1206,12 +1206,12 @@ static const ProtobufCFieldDescriptor open_channel__field_descriptors[7] =
     0,NULL,NULL    /* reserved1,reserved2, etc */
   },
   {
-    "locktime",
+    "delay",
     2,
     PROTOBUF_C_LABEL_REQUIRED,
     PROTOBUF_C_TYPE_MESSAGE,
     0,   /* quantifier_offset */
-    offsetof(OpenChannel, locktime),
+    offsetof(OpenChannel, delay),
     &locktime__descriptor,
     NULL,
     0,             /* flags */
@@ -1282,8 +1282,8 @@ static const unsigned open_channel__field_indices_by_name[] = {
   4,   /* field[4] = anch */
   3,   /* field[3] = commit_key */
   6,   /* field[6] = commitment_fee */
+  1,   /* field[1] = delay */
   0,   /* field[0] = final_key */
-  1,   /* field[1] = locktime */
   5,   /* field[5] = min_depth */
   2,   /* field[2] = revocation_hash */
 };
@@ -1551,12 +1551,12 @@ static const ProtobufCFieldDescriptor update_add_htlc__field_descriptors[4] =
     0,NULL,NULL    /* reserved1,reserved2, etc */
   },
   {
-    "locktime",
+    "expiry",
     4,
     PROTOBUF_C_LABEL_REQUIRED,
     PROTOBUF_C_TYPE_MESSAGE,
     0,   /* quantifier_offset */
-    offsetof(UpdateAddHtlc, locktime),
+    offsetof(UpdateAddHtlc, expiry),
     &locktime__descriptor,
     NULL,
     0,             /* flags */
@@ -1565,7 +1565,7 @@ static const ProtobufCFieldDescriptor update_add_htlc__field_descriptors[4] =
 };
 static const unsigned update_add_htlc__field_indices_by_name[] = {
   1,   /* field[1] = amount */
-  3,   /* field[3] = locktime */
+  3,   /* field[3] = expiry */
   2,   /* field[2] = r_hash */
   0,   /* field[0] = revocation_hash */
 };

lightning.pb-c.h

@@ -131,7 +131,7 @@ struct  _OpenChannel
   /*
    * Relative locktime for outputs going to us.
    */
-  Locktime *locktime;
+  Locktime *delay;
   /*
    * Hash for revoking first commitment transaction.
    */
@@ -264,7 +264,7 @@ struct  _UpdateAddHtlc
   /*
    * FIXME: Routing information.
    */
-  Locktime *locktime;
+  Locktime *expiry;
 };
 #define UPDATE_ADD_HTLC__INIT \
  { PROTOBUF_C_MESSAGE_INIT (&update_add_htlc__descriptor) \

lightning.proto

@@ -44,7 +44,7 @@ message bitcoin_pubkey {
 // Set channel params.
 message open_channel {
   // Relative locktime for outputs going to us.
-  required locktime locktime = 2;
+  required locktime delay = 2;
   // Hash for revoking first commitment transaction.
   required sha256_hash revocation_hash = 4;
   // Pubkey for anchor to pay into commitment tx.
@@ -109,7 +109,7 @@ message update_add_htlc {
   // Hash for HTLC R value.
   required sha256_hash r_hash = 3;
   // Time at which HTLC expires (absolute)
-  required locktime locktime = 4;
+  required locktime expiry = 4;
   // FIXME: Routing information.
 }
 

pkt.c

@@ -48,7 +48,7 @@ struct pkt *open_channel_pkt(const tal_t *ctx,
 	o.final_key = pubkey_to_proto(ctx, final);
 	lt.locktime_case = LOCKTIME__LOCKTIME_SECONDS;
 	lt.seconds = rel_locktime_seconds;
-	o.locktime = <
+	o.delay = <
 	o.commitment_fee = commitment_fee;
 	if (offer_anchor)
 		o.anch = OPEN_CHANNEL__ANCHOR_OFFER__WILL_CREATE_ANCHOR;

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->locktime, &locktime))
+	if (!proto_to_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->locktime, &locktime_seconds))
+	if (!proto_to_locktime(o1->delay, &locktime_seconds))
 		errx(1, "Invalid locktime in o2");
 
 	if (!pubkey_from_hexstr(argv[6], &outpubkey))