openingd: supply initial tx as well as signature.

And store in peer->last_tx/peer->last_sig like all other places,
that way we broadcast it if we need to.

Note: the removal of tmpctx in funder_channel() is needed because we
use txs[0], which was allocated off tmpctx.

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

lightningd/opening/opening.c

@@ -209,7 +209,6 @@ static u8 *funder_channel(struct state *state,
 			  const struct utxo *utxos,
 			  const struct ext_key *bip32_base)
 {
-	const tal_t *tmpctx = tal_tmpctx(state);
 	struct channel_id channel_id, id_in;
 	u8 *msg;
 	struct bitcoin_tx **txs;
@@ -243,7 +242,7 @@ static u8 *funder_channel(struct state *state,
 			      "push-msat must be < %"PRIu64,
 			      1000 * state->funding_satoshis);
 
-	msg = towire_open_channel(tmpctx,
+	msg = towire_open_channel(state,
 				  &state->chainparams->genesis_blockhash.sha,
 				  &channel_id,
 				  state->funding_satoshis, state->push_msat,
@@ -266,7 +265,7 @@ static u8 *funder_channel(struct state *state,
 
 	state->remoteconf = tal(state, struct channel_config);
 
-	msg = read_next_peer_msg(state, tmpctx);
+	msg = read_next_peer_msg(state, state);
 	if (!msg)
 		peer_failed(PEER_FD, &state->cs, NULL, WIRE_OPENING_PEER_READ_FAILED,
 			      "Reading accept_channel");
@@ -361,7 +360,7 @@ static u8 *funder_channel(struct state *state,
 	 * for the initial commitment transactions.  After receiving the
 	 * peer's signature, it will broadcast the funding transaction.
 	 */
-	txs = channel_txs(tmpctx, NULL, &wscripts, state->channel,
+	txs = channel_txs(state, NULL, &wscripts, state->channel,
 			  &state->next_per_commit[REMOTE], 0, REMOTE);
 
 	sign_tx_input(txs[0], 0, NULL, wscripts[0],
@@ -372,7 +371,7 @@ static u8 *funder_channel(struct state *state,
 		     type_to_string(trc, struct bitcoin_tx, txs[0]),
 		     type_to_string(trc, struct pubkey, our_funding_pubkey));
 
-	msg = towire_funding_created(tmpctx, &channel_id,
+	msg = towire_funding_created(state, &channel_id,
 				     &state->funding_txid.sha,
 				     state->funding_txout,
 				     &sig);
@@ -388,7 +387,7 @@ static u8 *funder_channel(struct state *state,
 	 * commitment transaction, so they can broadcast it knowing they can
 	 * redeem their funds if they need to.
 	 */
-	msg = read_next_peer_msg(state, tmpctx);
+	msg = read_next_peer_msg(state, state);
 	if (!msg)
 		peer_failed(PEER_FD, &state->cs, NULL, WIRE_OPENING_PEER_READ_FAILED,
 			      "Reading funding_signed");
@@ -419,7 +418,7 @@ static u8 *funder_channel(struct state *state,
 	 *
 	 * The recipient MUST fail the channel if `signature` is incorrect.
 	 */
-	txs = channel_txs(tmpctx, NULL, &wscripts, state->channel,
+	txs = channel_txs(state, NULL, &wscripts, state->channel,
 			  &state->next_per_commit[LOCAL], 0, LOCAL);
 
 	if (!check_tx_sig(txs[0], 0, NULL, wscripts[0], &their_funding_pubkey,
@@ -433,8 +432,6 @@ static u8 *funder_channel(struct state *state,
 					     &their_funding_pubkey));
 	}
 
-	tal_free(tmpctx);
-
 	/* BOLT #2:
 	 *
 	 * Once the channel funder receives the `funding_signed` message, they
@@ -442,6 +439,7 @@ static u8 *funder_channel(struct state *state,
 	 */
 	return towire_opening_funder_reply(state,
 					   state->remoteconf,
+					   txs[0],
 					   &sig,
 					   &state->cs,
 					   &theirs.revocation,
@@ -659,6 +657,7 @@ static u8 *fundee_channel(struct state *state,
 
 	return towire_opening_fundee_reply(state,
 					   state->remoteconf,
+					   txs[0],
 					   &theirsig,
 					   &state->cs,
 					   &theirs.revocation,

lightningd/opening/opening_wire.csv

@@ -26,6 +26,7 @@ opening_init,,crypto_state,struct crypto_state
 opening_init,,seed,struct privkey
 
 #include <lightningd/bip32.h>
+#include <lightningd/htlc_wire.h>
 # This means we offer the open.
 opening_funder,1
 opening_funder,,funding_satoshis,8
@@ -43,6 +44,7 @@ opening_funder,,bip32,struct ext_key
 # This gives their sig, means we can broadcast tx: we're done.
 opening_funder_reply,101
 opening_funder_reply,,their_config,struct channel_config
+opening_funder_reply,,first_commit,struct bitcoin_tx
 opening_funder_reply,,first_commit_sig,secp256k1_ecdsa_signature
 opening_funder_reply,,crypto_state,struct crypto_state
 opening_funder_reply,,revocation_basepoint,33
@@ -65,6 +67,7 @@ opening_fundee,,msg,len*u8
 # This gives their txid and info, means we can send funding_signed: we're done.
 opening_fundee_reply,103
 opening_fundee_reply,,their_config,struct channel_config
+opening_fundee_reply,,first_commit,struct bitcoin_tx
 opening_fundee_reply,,first_commit_sig,secp256k1_ecdsa_signature
 opening_fundee_reply,,crypto_state,struct crypto_state
 opening_fundee_reply,,revocation_basepoint,33

lightningd/peer_control.c

@@ -1633,7 +1633,7 @@ static bool peer_start_channeld(struct peer *peer,
 				      &peer->our_config,
 				      &peer->channel_info->their_config,
 				      peer->channel_info->feerate_per_kw,
-				      &peer->channel_info->commit_sig,
+				      peer->last_sig,
 				      cs,
 				      &peer->channel_info->remote_fundingkey,
 				      &peer->channel_info->theirbase.revocation,
@@ -1694,16 +1694,20 @@ static bool opening_funder_finished(struct subd *opening, const u8 *resp,
 	struct pubkey changekey;
 	struct pubkey local_fundingkey;
 	struct crypto_state cs;
+	secp256k1_ecdsa_signature remote_commit_sig;
+	struct bitcoin_tx *remote_commit;
 
 	assert(tal_count(fds) == 2);
 
 	/* At this point, we care about peer */
 	fc->peer->channel_info = channel_info
 		= tal(fc->peer, struct channel_info);
+	remote_commit = tal(resp, struct bitcoin_tx);
 
 	if (!fromwire_opening_funder_reply(resp, NULL,
 					   &channel_info->their_config,
-					   &channel_info->commit_sig,
+					   remote_commit,
+					   &remote_commit_sig,
 					   &cs,
 					   &channel_info->theirbase.revocation,
 					   &channel_info->theirbase.payment,
@@ -1721,6 +1725,9 @@ static bool opening_funder_finished(struct subd *opening, const u8 *resp,
 	/* old_remote_per_commit not valid yet, copy valid one. */
 	channel_info->old_remote_per_commit = channel_info->remote_per_commit;
 
+	/* Now, keep the initial commit as our last-tx-to-broadast. */
+	peer_last_tx(fc->peer, remote_commit, &remote_commit_sig);
+
 	/* Generate the funding tx. */
 	if (fc->change
 	    && !bip32_pubkey(fc->peer->ld->bip32_base,
@@ -1789,16 +1796,21 @@ static bool opening_fundee_finished(struct subd *opening,
 	u8 *funding_signed;
 	struct channel_info *channel_info;
 	struct crypto_state cs;
+	secp256k1_ecdsa_signature remote_commit_sig;
+	struct bitcoin_tx *remote_commit;
 
 	log_debug(peer->log, "Got opening_fundee_finish_response");
 	assert(tal_count(fds) == 2);
 
+	remote_commit = tal(reply, struct bitcoin_tx);
+
 	/* At this point, we care about peer */
 	peer->channel_info = channel_info = tal(peer, struct channel_info);
 	peer->funding_txid = tal(peer, struct sha256_double);
 	if (!fromwire_opening_fundee_reply(peer, reply, NULL,
 					   &channel_info->their_config,
-					   &channel_info->commit_sig,
+					   remote_commit,
+					   &remote_commit_sig,
 					   &cs,
 					   &channel_info->theirbase.revocation,
 					   &channel_info->theirbase.payment,
@@ -1819,6 +1831,9 @@ static bool opening_fundee_finished(struct subd *opening,
 	/* old_remote_per_commit not valid yet, copy valid one. */
 	channel_info->old_remote_per_commit = channel_info->remote_per_commit;
 
+	/* Now, keep the initial commit as our last-tx-to-broadast. */
+	peer_last_tx(peer, remote_commit, &remote_commit_sig);
+
 	if (!peer_commit_initial(peer))
 		return false;
 

lightningd/peer_htlcs.c

@@ -1058,7 +1058,6 @@ int peer_got_commitsig(struct peer *peer, const u8 *msg)
 	if (!peer_sending_revocation(peer, added, fulfilled, failed, changed))
 		return -1;
 
-	peer->channel_info->commit_sig = commit_sig;
 	if (!peer_save_commitsig_received(peer, commitnum))
 		return -1;
 

lightningd/peer_htlcs.h

@@ -8,7 +8,6 @@
 
 /* FIXME: Define serialization primitive for this? */
 struct channel_info {
-	secp256k1_ecdsa_signature commit_sig;
 	struct channel_config their_config;
 	struct pubkey remote_fundingkey;
 	struct basepoints theirbase;

wallet/db.c

@@ -58,7 +58,6 @@ char *dbmigrations[] = {
     "  push_msatoshi INTEGER,"
     "  msatoshi_local INTEGER," /* our_msatoshi */
     /* START channel_info */
-    "  commit_sig_remote BLOB,"
     "  fundingkey_remote BLOB,"
     "  revocation_basepoint_remote BLOB,"
     "  payment_basepoint_remote BLOB,"

wallet/wallet.c

@@ -474,7 +474,6 @@ static bool wallet_stmt2channel(struct wallet *w, sqlite3_stmt *stmt,
 		channel_info = chan->peer->channel_info;
 
 		/* Populate channel_info */
-		ok &= sqlite3_column_sig(stmt, col++, &chan->peer->channel_info->commit_sig);
 		ok &= sqlite3_column_pubkey(stmt, col++, &chan->peer->channel_info->remote_fundingkey);
 		ok &= sqlite3_column_pubkey(stmt, col++, &channel_info->theirbase.revocation);
 		ok &= sqlite3_column_pubkey(stmt, col++, &channel_info->theirbase.payment);
@@ -485,7 +484,7 @@ static bool wallet_stmt2channel(struct wallet *w, sqlite3_stmt *stmt,
 		wallet_channel_config_load(w, remote_config_id, &chan->peer->channel_info->their_config);
 	} else {
 		/* No channel_info, skip positions in the result */
-		col += 8;
+		col += 7;
 	}
 
 	/* Load shachain */
@@ -525,7 +524,7 @@ static bool wallet_stmt2channel(struct wallet *w, sqlite3_stmt *stmt,
 		col += 2;
 	}
 
-	assert(col == 34);
+	assert(col == 33);
 
 	return ok;
 }
@@ -543,7 +542,6 @@ bool wallet_channel_load(struct wallet *w, const u64 id,
 	    "next_index_local, next_index_remote, num_revocations_received, "
 	    "next_htlc_id, funding_tx_id, funding_tx_outnum, funding_satoshi, "
 	    "funding_locked_remote, push_msatoshi, msatoshi_local, "
-	    "commit_sig_remote, "
 	    "fundingkey_remote, revocation_basepoint_remote, "
 	    "payment_basepoint_remote, "
 	    "delayed_payment_basepoint_remote, per_commit_remote, "
@@ -722,7 +720,6 @@ bool wallet_channel_save(struct wallet *w, struct wallet_channel *chan){
 		ok &= wallet_channel_config_save(w, &p->channel_info->their_config);
 		ok &= db_exec(__func__, w->db,
 			      "UPDATE channels SET"
-			      "  commit_sig_remote=%s,"
 			      "  fundingkey_remote='%s',"
 			      "  revocation_basepoint_remote='%s',"
 			      "  payment_basepoint_remote='%s',"
@@ -732,7 +729,6 @@ bool wallet_channel_save(struct wallet *w, struct wallet_channel *chan){
 			      "  feerate_per_kw=%d,"
 			      "  channel_config_remote=%"PRIu64
 			      " WHERE id=%"PRIu64,
-			      db_serialize_signature(tmpctx, &p->channel_info->commit_sig),
 			      db_serialize_pubkey(tmpctx, &p->channel_info->remote_fundingkey),
 			      db_serialize_pubkey(tmpctx, &p->channel_info->theirbase.revocation),
 			      db_serialize_pubkey(tmpctx, &p->channel_info->theirbase.payment),

wallet/wallet_tests.c

@@ -148,8 +148,6 @@ static bool channelseq(struct wallet_channel *c1, struct wallet_channel *c2)
 		      sizeof(struct sha256_double)));
 	CHECK((ci1 != NULL) ==  (ci2 != NULL));
 	if(ci1) {
-		CHECK(memeq(&ci1->commit_sig, sizeof(secp256k1_ecdsa_signature),
-			    &ci2->commit_sig, sizeof(secp256k1_ecdsa_signature)));
 		CHECK(pubkey_eq(&ci1->remote_fundingkey, &ci2->remote_fundingkey));
 		CHECK(pubkey_eq(&ci1->theirbase.revocation, &ci2->theirbase.revocation));
 		CHECK(pubkey_eq(&ci1->theirbase.payment, &ci2->theirbase.payment));