protocol: include next revocation hash in open packet.

This means we send the first two revocation hashes; this is important
once we move to a commit model as we need to send (unsolicited) the
signature for the *next* commit tx so we need its commit hash.

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

daemon/packets.c

@@ -74,6 +74,7 @@ Pkt *pkt_open(const tal_t *ctx, const struct peer *peer,
 
 	open_channel__init(o);
 	o->revocation_hash = sha256_to_proto(ctx, &peer->us.revocation_hash);
+	o->next_revocation_hash = sha256_to_proto(ctx, &peer->us.next_revocation_hash);
 	o->commit_key = pubkey_to_proto(o, &peer->us.commitkey);
 	o->final_key = pubkey_to_proto(o, &peer->us.finalkey);
 	o->delay = tal(o, Locktime);
@@ -317,6 +318,7 @@ Pkt *accept_pkt_open(const tal_t *ctx,
 			     o->final_key, &peer->them.finalkey))
 		return pkt_err(ctx, "Bad finalkey");
 	proto_to_sha256(o->revocation_hash, &peer->them.revocation_hash);
+	proto_to_sha256(o->next_revocation_hash, &peer->them.next_revocation_hash);
 
 	/* Redeemscript for anchor. */
 	peer->anchor.redeemscript

daemon/peer.c

@@ -270,6 +270,7 @@ static struct io_plan *peer_crypto_on(struct io_conn *conn, struct peer *peer)
 {
 	peer_secrets_init(peer);
 	peer_get_revocation_hash(peer, 0, &peer->us.revocation_hash);
+	peer_get_revocation_hash(peer, 1, &peer->us.next_revocation_hash);
 
 	assert(peer->state == STATE_INIT);
 

daemon/peer.h

@@ -55,6 +55,8 @@ struct peer_visible_state {
 	u64 commit_fee;
 	/* Revocation hash for latest commit tx. */
 	struct sha256 revocation_hash;
+	/* Revocation hash for next commit tx. */
+	struct sha256 next_revocation_hash;
 	/* Current commit tx. */
 	struct bitcoin_tx *commit;
 };

lightning.pb-c.c

@@ -1381,7 +1381,7 @@ const ProtobufCEnumDescriptor open_channel__anchor_offer__descriptor =
   NULL,NULL,NULL,NULL   /* reserved[1234] */
 };
 static const uint32_t open_channel__min_depth__default_value = 0u;
-static const ProtobufCFieldDescriptor open_channel__field_descriptors[7] =
+static const ProtobufCFieldDescriptor open_channel__field_descriptors[8] =
 {
   {
     "delay",
@@ -1467,6 +1467,18 @@ static const ProtobufCFieldDescriptor open_channel__field_descriptors[7] =
     0,             /* flags */
     0,NULL,NULL    /* reserved1,reserved2, etc */
   },
+  {
+    "next_revocation_hash",
+    8,
+    PROTOBUF_C_LABEL_REQUIRED,
+    PROTOBUF_C_TYPE_MESSAGE,
+    0,   /* quantifier_offset */
+    offsetof(OpenChannel, next_revocation_hash),
+    &sha256_hash__descriptor,
+    NULL,
+    0,             /* flags */
+    0,NULL,NULL    /* reserved1,reserved2, etc */
+  },
 };
 static const unsigned open_channel__field_indices_by_name[] = {
   4,   /* field[4] = anch */
@@ -1475,12 +1487,13 @@ static const unsigned open_channel__field_indices_by_name[] = {
   0,   /* field[0] = delay */
   3,   /* field[3] = final_key */
   5,   /* field[5] = min_depth */
+  7,   /* field[7] = next_revocation_hash */
   1,   /* field[1] = revocation_hash */
 };
 static const ProtobufCIntRange open_channel__number_ranges[1 + 1] =
 {
   { 1, 0 },
-  { 0, 7 }
+  { 0, 8 }
 };
 const ProtobufCMessageDescriptor open_channel__descriptor =
 {
@@ -1490,7 +1503,7 @@ const ProtobufCMessageDescriptor open_channel__descriptor =
   "OpenChannel",
   "",
   sizeof(OpenChannel),
-  7,
+  8,
   open_channel__field_descriptors,
   open_channel__field_indices_by_name,
   1,  open_channel__number_ranges,

lightning.pb-c.h

@@ -180,6 +180,10 @@ struct  _OpenChannel
    * Hash for revoking first commitment transaction.
    */
   Sha256Hash *revocation_hash;
+  /*
+   * Hash for revoking second commitment transaction.
+   */
+  Sha256Hash *next_revocation_hash;
   /*
    * Pubkey for anchor to pay into commitment tx.
    */
@@ -201,7 +205,7 @@ struct  _OpenChannel
 };
 #define OPEN_CHANNEL__INIT \
  { PROTOBUF_C_MESSAGE_INIT (&open_channel__descriptor) \
-    , NULL, NULL, NULL, NULL, 0, 0,0u, 0 }
+    , NULL, NULL, NULL, NULL, NULL, 0, 0,0u, 0 }
 
 
 /*

lightning.proto

@@ -65,6 +65,8 @@ message open_channel {
   required locktime delay = 1;
   // Hash for revoking first commitment transaction.
   required sha256_hash revocation_hash = 2;
+  // Hash for revoking second commitment transaction.
+  required sha256_hash next_revocation_hash = 8;
   // Pubkey for anchor to pay into commitment tx.
   required bitcoin_pubkey commit_key = 3;
   // How to pay money to us from commit_tx.