tx: Add chainparams to struct bitcoin_tx as context

The way we build transactions, serialize them, and compute fees depends on the
chain we are working on, so let's add some context to the transactions.

Signed-off-by: Christian Decker <[email protected]>

bitcoin/tx.c

@@ -276,17 +276,20 @@ static void bitcoin_tx_destroy(struct bitcoin_tx *tx)
 	wally_tx_free(tx->wtx);
 }
 
-struct bitcoin_tx *bitcoin_tx(const tal_t *ctx, varint_t input_count,
-			      varint_t output_count)
+struct bitcoin_tx *bitcoin_tx(const tal_t *ctx,
+			      const struct chainparams *chainparams,
+			      varint_t input_count, varint_t output_count)
 {
 	struct bitcoin_tx *tx = tal(ctx, struct bitcoin_tx);
+
 	wally_tx_init_alloc(WALLY_TX_VERSION_2, 0, input_count, output_count,
 			    &tx->wtx);
 	tal_add_destructor(tx, bitcoin_tx_destroy);
 
 	tx->input_amounts = tal_arrz(tx, struct amount_sat*, input_count);
 	tx->wtx->locktime = 0;
 	tx->wtx->version = 2;
+	tx->chainparams = chainparams;
 	return tx;
 }
 
@@ -305,6 +308,7 @@ struct bitcoin_tx *pull_bitcoin_tx(const tal_t *ctx, const u8 **cursor,
 	/* We don't know the input amounts yet, so set them all to NULL */
 	tx->input_amounts =
 	    tal_arrz(tx, struct amount_sat *, tx->wtx->inputs_allocation_len);
+	tx->chainparams = NULL;
 
 	*cursor += wsize;
 	*max -= wsize;

bitcoin/tx.h

@@ -23,6 +23,9 @@ struct bitcoin_tx {
 	 * unknown) */
 	struct amount_sat **input_amounts;
 	struct wally_tx *wtx;
+
+	/* Keep a reference to the ruleset we have to abide by */
+	const struct chainparams *chainparams;
 };
 
 struct bitcoin_tx_output {
@@ -52,8 +55,9 @@ size_t measure_tx_weight(const struct bitcoin_tx *tx);
 
 /* Allocate a tx: you just need to fill in inputs and outputs (they're
  * zeroed with inputs' sequence_number set to FFFFFFFF) */
-struct bitcoin_tx *bitcoin_tx(const tal_t *ctx, varint_t input_count,
-			      varint_t output_count);
+struct bitcoin_tx *bitcoin_tx(const tal_t *ctx,
+			      const struct chainparams *chainparams,
+			      varint_t input_count, varint_t output_count);
 
 /* This takes a raw bitcoin tx in hex. */
 struct bitcoin_tx *bitcoin_tx_from_hex(const tal_t *ctx, const char *hex,

channeld/channeld.c

@@ -979,10 +979,9 @@ static secp256k1_ecdsa_signature *calc_commitsigs(const tal_t *ctx,
 	const u8 *msg;
 	secp256k1_ecdsa_signature *htlc_sigs;
 
-	txs = channel_txs(tmpctx, &htlc_map, &wscripts, peer->channel,
-			  &peer->remote_per_commit,
-			  commit_index,
-			  REMOTE);
+	txs = channel_txs(tmpctx, peer->channel->chainparams, &htlc_map,
+			  &wscripts, peer->channel, &peer->remote_per_commit,
+			  commit_index, REMOTE);
 
 	msg = towire_hsm_sign_remote_commitment_tx(NULL, txs[0],
 						   &peer->channel->funding_pubkey[REMOTE],
@@ -1398,9 +1397,10 @@ static void handle_peer_commit_sig(struct peer *peer, const u8 *msg)
 	/* SIGHASH_ALL is implied. */
 	commit_sig.sighash_type = SIGHASH_ALL;
 
-	txs = channel_txs(tmpctx, &htlc_map, &wscripts, peer->channel,
-			  &peer->next_local_per_commit,
-			  peer->next_index[LOCAL], LOCAL);
+	txs =
+	    channel_txs(tmpctx, peer->channel->chainparams, &htlc_map,
+			&wscripts, peer->channel, &peer->next_local_per_commit,
+			peer->next_index[LOCAL], LOCAL);
 
 	if (!derive_simple_key(&peer->channel->basepoints[REMOTE].htlc,
 			       &peer->next_local_per_commit, &remote_htlckey))

channeld/commit_tx.c

@@ -76,6 +76,7 @@ static void add_received_htlc_out(struct bitcoin_tx *tx, size_t n,
 }
 
 struct bitcoin_tx *commit_tx(const tal_t *ctx,
+			     const struct chainparams *chainparams,
 			     const struct bitcoin_txid *funding_txid,
 			     unsigned int funding_txout,
 			     struct amount_sat funding,
@@ -146,7 +147,7 @@ struct bitcoin_tx *commit_tx(const tal_t *ctx,
 #endif
 
 	/* Worst-case sizing: both to-local and to-remote outputs. */
-	tx = bitcoin_tx(ctx, 1, untrimmed + 2);
+	tx = bitcoin_tx(ctx, chainparams, 1, untrimmed + 2);
 
 	/* We keep track of which outputs have which HTLCs */
 	*htlcmap = tal_arr(tx, const struct htlc *, tx->wtx->outputs_allocation_len);

channeld/commit_tx.h

@@ -1,6 +1,7 @@
 #ifndef LIGHTNING_CHANNELD_COMMIT_TX_H
 #define LIGHTNING_CHANNELD_COMMIT_TX_H
 #include "config.h"
+#include <bitcoin/chainparams.h>
 #include <bitcoin/pubkey.h>
 #include <channeld/channeld_htlc.h>
 #include <common/htlc.h>
@@ -43,6 +44,7 @@ size_t commit_tx_num_untrimmed(const struct htlc **htlcs,
  * transaction, so we carefully use the terms "self" and "other" here.
  */
 struct bitcoin_tx *commit_tx(const tal_t *ctx,
+			     const struct chainparams *chainparams,
 			     const struct bitcoin_txid *funding_txid,
 			     unsigned int funding_txout,
 			     struct amount_sat funding,

channeld/full_channel.c

@@ -187,7 +187,8 @@ static bool sum_offered_msatoshis(struct amount_msat *total,
 	return true;
 }
 
-static void add_htlcs(struct bitcoin_tx ***txs,
+static void add_htlcs(const struct chainparams *chainparams,
+		      struct bitcoin_tx ***txs,
 		      const u8 ***wscripts,
 		      const struct htlc **htlcmap,
 		      const struct channel *channel,
@@ -210,7 +211,7 @@ static void add_htlcs(struct bitcoin_tx ***txs,
 			continue;
 
 		if (htlc_owner(htlc) == side) {
-			tx = htlc_timeout_tx(*txs, &txid, i,
+			tx = htlc_timeout_tx(*txs, chainparams, &txid, i,
 					     htlc->amount,
 					     htlc->expiry.locktime,
 					     channel->config[!side].to_self_delay,
@@ -222,7 +223,7 @@ static void add_htlcs(struct bitcoin_tx ***txs,
 						     &htlc->rhash,
 						     &keyset->self_revocation_key);
 		} else {
-			tx = htlc_success_tx(*txs, &txid, i,
+			tx = htlc_success_tx(*txs, chainparams, &txid, i,
 					     htlc->amount,
 					     channel->config[!side].to_self_delay,
 					     feerate_per_kw,
@@ -245,6 +246,7 @@ static void add_htlcs(struct bitcoin_tx ***txs,
 
 /* FIXME: We could cache these. */
 struct bitcoin_tx **channel_txs(const tal_t *ctx,
+				const struct chainparams *chainparams,
 				const struct htlc ***htlcmap,
 				const u8 ***wscripts,
 				const struct channel *channel,
@@ -266,27 +268,21 @@ struct bitcoin_tx **channel_txs(const tal_t *ctx,
 	gather_htlcs(ctx, channel, side, &committed, NULL, NULL);
 
 	txs = tal_arr(ctx, struct bitcoin_tx *, 1);
-	txs[0] = commit_tx(ctx, &channel->funding_txid,
-		       channel->funding_txout,
-		       channel->funding,
-		       channel->funder,
-		       channel->config[!side].to_self_delay,
-		       &keyset,
-		       channel->view[side].feerate_per_kw,
-		       channel->config[side].dust_limit,
-		       channel->view[side].owed[side],
-		       channel->view[side].owed[!side],
-		       committed,
-		       htlcmap,
-		       commitment_number ^ channel->commitment_number_obscurer,
-		       side);
+	txs[0] = commit_tx(
+	    ctx, chainparams, &channel->funding_txid, channel->funding_txout,
+	    channel->funding, channel->funder,
+	    channel->config[!side].to_self_delay, &keyset,
+	    channel->view[side].feerate_per_kw,
+	    channel->config[side].dust_limit, channel->view[side].owed[side],
+	    channel->view[side].owed[!side], committed, htlcmap,
+	    commitment_number ^ channel->commitment_number_obscurer, side);
 
 	*wscripts = tal_arr(ctx, const u8 *, 1);
 	(*wscripts)[0] = bitcoin_redeem_2of2(*wscripts,
 					     &channel->funding_pubkey[side],
 					     &channel->funding_pubkey[!side]);
 
-	add_htlcs(&txs, wscripts, *htlcmap, channel, &keyset, side);
+	add_htlcs(chainparams, &txs, wscripts, *htlcmap, channel, &keyset, side);
 
 	tal_free(committed);
 	return txs;

channeld/full_channel.h

@@ -47,6 +47,7 @@ struct channel *new_full_channel(const tal_t *ctx,
 /**
  * channel_txs: Get the current commitment and htlc txs for the channel.
  * @ctx: tal context to allocate return value from.
+ * @chainparams: Parameters for the generated transactions.
  * @channel: The channel to evaluate
  * @htlc_map: Pointer to htlcs for each tx output (allocated off @ctx).
  * @wscripts: Pointer to array of wscript for each tx returned (alloced off @ctx)
@@ -59,6 +60,7 @@ struct channel *new_full_channel(const tal_t *ctx,
  * fills in @htlc_map, or NULL on key derivation failure.
  */
 struct bitcoin_tx **channel_txs(const tal_t *ctx,
+				const struct chainparams *chainparams,
 				const struct htlc ***htlcmap,
 				const u8 ***wscripts,
 				const struct channel *channel,

channeld/test/run-commit_tx.c

@@ -222,7 +222,8 @@ static void report_htlcs(const struct bitcoin_tx *tx,
 			continue;
 
 		if (htlc_owner(htlc) == LOCAL) {
-			htlc_tx[i] = htlc_timeout_tx(htlc_tx, &txid, i,
+			htlc_tx[i] = htlc_timeout_tx(htlc_tx, tx->chainparams,
+						     &txid, i,
 						     htlc->amount,
 						     htlc->expiry.locktime,
 						     to_self_delay,
@@ -234,7 +235,8 @@ static void report_htlcs(const struct bitcoin_tx *tx,
 								&htlc->rhash,
 								remote_revocation_key);
 		} else {
-			htlc_tx[i] = htlc_success_tx(htlc_tx, &txid, i,
+			htlc_tx[i] = htlc_success_tx(htlc_tx, tx->chainparams,
+						     &txid, i,
 						     htlc->amount,
 						     to_self_delay,
 						     feerate_per_kw,
@@ -457,6 +459,7 @@ int main(void)
 	u64 commitment_number, cn_obscurer;
 	struct amount_msat to_local, to_remote;
 	const struct htlc **htlcs, **htlc_map, **htlc_map2, **inv_htlcs;
+	const struct chainparams *chainparams = chainparams_for_network("bitcoin");
 
 	secp256k1_ctx = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY
 						 | SECP256K1_CONTEXT_SIGN);
@@ -712,7 +715,8 @@ int main(void)
 	keyset.other_htlc_key = remote_htlckey;
 
 	print_superverbose = true;
-	tx = commit_tx(tmpctx, &funding_txid, funding_output_index,
+	tx = commit_tx(tmpctx, chainparams,
+		       &funding_txid, funding_output_index,
 		       funding_amount,
 		       LOCAL, to_self_delay,
 		       &keyset,
@@ -723,7 +727,8 @@ int main(void)
 		       NULL, &htlc_map, commitment_number ^ cn_obscurer,
 		       LOCAL);
 	print_superverbose = false;
-	tx2 = commit_tx(tmpctx, &funding_txid, funding_output_index,
+	tx2 = commit_tx(tmpctx, chainparams,
+			&funding_txid, funding_output_index,
 			funding_amount,
 			REMOTE, to_self_delay,
 			&keyset,
@@ -766,7 +771,8 @@ int main(void)
 	       to_local.millisatoshis, to_remote.millisatoshis, feerate_per_kw);
 
 	print_superverbose = true;
-	tx = commit_tx(tmpctx, &funding_txid, funding_output_index,
+	tx = commit_tx(tmpctx, chainparams,
+		       &funding_txid, funding_output_index,
 		       funding_amount,
 		       LOCAL, to_self_delay,
 		       &keyset,
@@ -777,7 +783,8 @@ int main(void)
 		       htlcs, &htlc_map, commitment_number ^ cn_obscurer,
 		       LOCAL);
 	print_superverbose = false;
-	tx2 = commit_tx(tmpctx, &funding_txid, funding_output_index,
+	tx2 = commit_tx(tmpctx, chainparams,
+			&funding_txid, funding_output_index,
 			funding_amount,
 			REMOTE, to_self_delay,
 			&keyset,
@@ -808,7 +815,8 @@ int main(void)
 
 		feerate_per_kw = increase(feerate_per_kw);
 		print_superverbose = false;
-		newtx = commit_tx(tmpctx, &funding_txid, funding_output_index,
+		newtx = commit_tx(tmpctx, chainparams,
+				  &funding_txid, funding_output_index,
 				  funding_amount,
 				  LOCAL, to_self_delay,
 				  &keyset,
@@ -820,7 +828,8 @@ int main(void)
 				  commitment_number ^ cn_obscurer,
 				  LOCAL);
 		/* This is what it would look like for peer generating it! */
-		tx2 = commit_tx(tmpctx, &funding_txid, funding_output_index,
+		tx2 = commit_tx(tmpctx, chainparams,
+				&funding_txid, funding_output_index,
 				funding_amount,
 				REMOTE, to_self_delay,
 				&keyset,
@@ -851,7 +860,8 @@ int main(void)
 		       to_local.millisatoshis, to_remote.millisatoshis, feerate_per_kw-1);
 		/* Recalc with verbosity on */
 		print_superverbose = true;
-		tx = commit_tx(tmpctx, &funding_txid, funding_output_index,
+		tx = commit_tx(tmpctx, chainparams,
+			       &funding_txid, funding_output_index,
 			       funding_amount,
 			       LOCAL, to_self_delay,
 			       &keyset,
@@ -887,7 +897,8 @@ int main(void)
 		       to_local.millisatoshis, to_remote.millisatoshis, feerate_per_kw);
 		/* Recalc with verbosity on */
 		print_superverbose = true;
-		newtx = commit_tx(tmpctx, &funding_txid, funding_output_index,
+		newtx = commit_tx(tmpctx, chainparams,
+				  &funding_txid, funding_output_index,
 				  funding_amount,
 				  LOCAL, to_self_delay,
 				  &keyset,
@@ -945,7 +956,8 @@ int main(void)
 		       "to_remote_msat: %"PRIu64"\n"
 		       "local_feerate_per_kw: %u\n",
 		       to_local.millisatoshis, to_remote.millisatoshis, feerate_per_kw);
-		tx = commit_tx(tmpctx, &funding_txid, funding_output_index,
+		tx = commit_tx(tmpctx, chainparams,
+			       &funding_txid, funding_output_index,
 			       funding_amount,
 			       LOCAL, to_self_delay,
 			       &keyset,