watchtower: Call the commitment_revoked hook every time we update

Changelog-Added: plugin: Added a new `commitment_revocation` hook that provides the plugin with penalty transactions for all revoked transactions.

channeld/channel_wire.csv

@@ -154,6 +154,7 @@ msgdata,channel_got_revoke,fee_states,fee_states,
 msgdata,channel_got_revoke,num_changed,u16,
 msgdata,channel_got_revoke,changed,changed_htlc,num_changed
 msgdata,channel_got_revoke,pbase,?penalty_base,
+msgdata,channel_got_revoke,penalty_tx,?bitcoin_tx,
 # Wait for reply, to make sure it's on disk before we continue
 # (eg. if we sent another commitment_signed, that would implicitly ack).
 msgtype,channel_got_revoke_reply,1122

channeld/channeld.c

@@ -27,6 +27,7 @@
 #include <channeld/commit_tx.h>
 #include <channeld/full_channel.h>
 #include <channeld/gen_channel_wire.h>
+#include <channeld/watchtower.h>
 #include <common/blinding.h>
 #include <common/crypto_sync.h>
 #include <common/dev_disconnect.h>
@@ -1394,6 +1395,7 @@ static u8 *got_revoke_msg(struct peer *peer, u64 revoke_num,
 	u8 *msg;
 	struct penalty_base *pbase;
 	struct changed_htlc *changed = tal_arr(tmpctx, struct changed_htlc, 0);
+	const struct bitcoin_tx *ptx = NULL;
 
 	for (size_t i = 0; i < tal_count(changed_htlcs); i++) {
 		struct changed_htlc c;
@@ -1409,9 +1411,18 @@ static u8 *got_revoke_msg(struct peer *peer, u64 revoke_num,
 	}
 
 	pbase = penalty_base_by_commitnum(tmpctx, peer, revoke_num);
+
+	if (pbase) {
+		ptx = penalty_tx_create(
+		    NULL, peer->channel, peer->feerate_penalty,
+		    peer->final_scriptpubkey, per_commitment_secret,
+		    &pbase->txid, pbase->outnum, pbase->amount);
+	}
+
 	msg = towire_channel_got_revoke(peer, revoke_num, per_commitment_secret,
 					next_per_commit_point, fee_states,
-					changed, pbase);
+					changed, pbase, ptx);
+	tal_free(ptx);
 	return msg;
 }
 

lightningd/peer_htlcs.c

@@ -1971,6 +1971,41 @@ void update_per_commit_point(struct channel *channel,
 	ci->remote_per_commit = *per_commitment_point;
 }
 
+struct commitment_revocation_payload {
+	struct bitcoin_txid commitment_txid;
+	const struct bitcoin_tx *penalty_tx;
+	struct wallet *wallet;
+	u64 channel_id;
+	u64 commitnum;
+};
+
+static void commitment_revocation_hook_serialize(
+    struct commitment_revocation_payload *payload, struct json_stream *stream)
+{
+	json_add_txid(stream, "commitment_txid", &payload->commitment_txid);
+	json_add_tx(stream, "penalty_tx", payload->penalty_tx);
+}
+
+static void
+commitment_revocation_hook_cb(struct commitment_revocation_payload *p STEALS){
+	wallet_penalty_base_delete(p->wallet, p->channel_id, p->commitnum);
+}
+
+static bool
+commitment_revocation_hook_deserialize(struct commitment_revocation_payload *p,
+				       const char *buffer,
+				       const jsmntok_t *toks)
+{
+	return true;
+}
+
+
+REGISTER_PLUGIN_HOOK(commitment_revocation,
+		     commitment_revocation_hook_deserialize,
+		     commitment_revocation_hook_cb,
+		     commitment_revocation_hook_serialize,
+		     struct commitment_revocation_payload *);
+
 void peer_got_revoke(struct channel *channel, const u8 *msg)
 {
 	u64 revokenum;
@@ -1983,13 +2018,16 @@ void peer_got_revoke(struct channel *channel, const u8 *msg)
 	struct lightningd *ld = channel->peer->ld;
 	struct fee_states *fee_states;
 	struct penalty_base *pbase;
+	struct commitment_revocation_payload *payload;
+	struct bitcoin_tx *penalty_tx;
 
 	if (!fromwire_channel_got_revoke(msg, msg,
 					 &revokenum, &per_commitment_secret,
 					 &next_per_commitment_point,
 					 &fee_states,
 					 &changed,
-					 &pbase)
+					 &pbase,
+					 &penalty_tx)
 	    || !fee_states_valid(fee_states, channel->opener)) {
 		channel_internal_error(channel, "bad fromwire_channel_got_revoke %s",
 				    tal_hex(channel, msg));
@@ -2082,6 +2120,17 @@ void peer_got_revoke(struct channel *channel, const u8 *msg)
 					     : fromwire_peektype(failmsgs[i]));
 	}
 	wallet_channel_save(ld->wallet, channel);
+
+	if (penalty_tx == NULL)
+		return;
+
+	payload = tal(tmpctx, struct commitment_revocation_payload);
+	payload->commitment_txid = pbase->txid;
+	payload->penalty_tx = tal_steal(payload, penalty_tx);
+	payload->wallet = ld->wallet;
+	payload->channel_id = channel->dbid;
+	payload->commitnum = pbase->commitment_num;
+	plugin_hook_call_commitment_revocation(ld, payload);
 }
 
 

wallet/test/run-wallet.c

@@ -116,7 +116,7 @@ bool fromwire_channel_dev_memleak_reply(const void *p UNNEEDED, bool *leak UNNEE
 bool fromwire_channel_got_commitsig(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, u64 *commitnum UNNEEDED, struct fee_states **fee_states UNNEEDED, struct bitcoin_signature *signature UNNEEDED, secp256k1_ecdsa_signature **htlc_signature UNNEEDED, struct added_htlc **added UNNEEDED, struct fulfilled_htlc **fulfilled UNNEEDED, struct failed_htlc ***failed UNNEEDED, struct changed_htlc **changed UNNEEDED, struct bitcoin_tx **tx UNNEEDED)
 { fprintf(stderr, "fromwire_channel_got_commitsig called!\n"); abort(); }
 /* Generated stub for fromwire_channel_got_revoke */
-bool fromwire_channel_got_revoke(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, u64 *revokenum UNNEEDED, struct secret *per_commitment_secret UNNEEDED, struct pubkey *next_per_commit_point UNNEEDED, struct fee_states **fee_states UNNEEDED, struct changed_htlc **changed UNNEEDED, struct penalty_base **pbase UNNEEDED)
+bool fromwire_channel_got_revoke(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, u64 *revokenum UNNEEDED, struct secret *per_commitment_secret UNNEEDED, struct pubkey *next_per_commit_point UNNEEDED, struct fee_states **fee_states UNNEEDED, struct changed_htlc **changed UNNEEDED, struct penalty_base **pbase UNNEEDED, struct bitcoin_tx **penalty_tx UNNEEDED)
 { fprintf(stderr, "fromwire_channel_got_revoke called!\n"); abort(); }
 /* Generated stub for fromwire_channel_offer_htlc_reply */
 bool fromwire_channel_offer_htlc_reply(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, u64 *id UNNEEDED, u8 **failuremsg UNNEEDED, wirestring **failurestr UNNEEDED)