struct channel: remove most helpers.

They were not universally used, and most are trivial accessors anyway.

The exception is getting the channel reserve: we have to multiply by 1000
as well as flip direction, so keep that one.

The BOLT quotes move to `struct channel_config`.

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

channeld/channeld.c

@@ -2340,7 +2340,7 @@ static void handle_offer_htlc(struct peer *peer, const u8 *inmsg)
 	case CHANNEL_ERR_HTLC_BELOW_MINIMUM:
 		failcode = WIRE_AMOUNT_BELOW_MINIMUM;
 		failmsg = tal_fmt(inmsg, "HTLC too small (%"PRIu64" minimum)",
-				  htlc_minimum_msat(peer->channel, REMOTE));
+				  peer->channel->config[REMOTE]->htlc_minimum_msat);
 		goto failed;
 	case CHANNEL_ERR_TOO_MANY_HTLCS:
 		failcode = WIRE_TEMPORARY_CHANNEL_FAILURE;

channeld/full_channel.c

@@ -202,7 +202,7 @@ static void add_htlcs(struct bitcoin_tx ***txs,
 			tx = htlc_timeout_tx(*txs, &txid, i,
 					     htlc->msatoshi,
 					     htlc->expiry.locktime,
-					     to_self_delay(channel, side),
+					     channel->config[!side]->to_self_delay,
 					     feerate_per_kw,
 					     keyset);
 			wscript	= bitcoin_wscript_htlc_offer(*wscripts,
@@ -213,7 +213,7 @@ static void add_htlcs(struct bitcoin_tx ***txs,
 		} else {
 			tx = htlc_success_tx(*txs, &txid, i,
 					     htlc->msatoshi,
-					     to_self_delay(channel, side),
+					     channel->config[!side]->to_self_delay,
 					     feerate_per_kw,
 					     keyset);
 			wscript	= bitcoin_wscript_htlc_receive(*wscripts,
@@ -259,10 +259,10 @@ struct bitcoin_tx **channel_txs(const tal_t *ctx,
 		       channel->funding_txout,
 		       channel->funding_msat / 1000,
 		       channel->funder,
-		       to_self_delay(channel, side),
+		       channel->config[!side]->to_self_delay,
 		       &keyset,
 		       channel->view[side].feerate_per_kw,
-		       dust_limit_satoshis(channel, side),
+		       channel->config[side]->dust_limit_satoshis,
 		       channel->view[side].owed_msat[side],
 		       channel->view[side].owed_msat[!side],
 		       committed,
@@ -348,7 +348,7 @@ static enum channel_add_err add_htlc(struct channel *channel,
 	if (htlc->msatoshi == 0) {
 		return CHANNEL_ERR_HTLC_BELOW_MINIMUM;
 	}
-	if (htlc->msatoshi < htlc_minimum_msat(channel, recipient)) {
+	if (htlc->msatoshi < channel->config[recipient]->htlc_minimum_msat) {
 		return CHANNEL_ERR_HTLC_BELOW_MINIMUM;
 	}
 
@@ -373,7 +373,7 @@ static enum channel_add_err add_htlc(struct channel *channel,
 	 */
 	if (enforce_aggregate_limits
 	    && tal_count(committed) - tal_count(removing) + tal_count(adding)
-	    > max_accepted_htlcs(channel, recipient)) {
+	    > channel->config[recipient]->max_accepted_htlcs) {
 		return CHANNEL_ERR_TOO_MANY_HTLCS;
 	}
 
@@ -389,7 +389,7 @@ static enum channel_add_err add_htlc(struct channel *channel,
 	 *     - SHOULD fail the channel.
 	 */
 	if (enforce_aggregate_limits
-	    && msat_in_htlcs > max_htlc_value_in_flight_msat(channel, recipient)) {
+	    && msat_in_htlcs > channel->config[recipient]->max_htlc_value_in_flight_msat) {
 		return CHANNEL_ERR_MAX_HTLC_VALUE_EXCEEDED;
 	}
 
@@ -404,7 +404,7 @@ static enum channel_add_err add_htlc(struct channel *channel,
 	 */
 	if (channel->funder == htlc_owner(htlc)) {
 		u32 feerate = view->feerate_per_kw;
-		u64 dust = dust_limit_satoshis(channel, recipient);
+		u64 dust = channel->config[recipient]->dust_limit_satoshis;
 		size_t untrimmed;
 
 		untrimmed = commit_tx_num_untrimmed(committed, feerate, dust,
@@ -701,7 +701,7 @@ u32 approx_max_feerate(const struct channel *channel)
 
 bool can_funder_afford_feerate(const struct channel *channel, u32 feerate_per_kw)
 {
-	u64 fee_msat, dust = dust_limit_satoshis(channel, !channel->funder);
+	u64 fee_msat, dust = channel->config[!channel->funder]->dust_limit_satoshis;
 	size_t untrimmed;
 	const struct htlc **committed, **adding, **removing;
 	gather_htlcs(tmpctx, channel, !channel->funder,

common/channel_config.h

@@ -34,11 +34,43 @@
 struct channel_config {
 	/* Database ID */
 	u64 id;
+	/* BOLT #2:
+	 *
+	 * `dust_limit_satoshis` is the threshold below which outputs should
+	 * not be generated for this node's commitment or HTLC transaction */
 	u64 dust_limit_satoshis;
+
+	/* BOLT #2:
+	 *
+	 * `max_htlc_value_in_flight_msat` is a cap on total value of
+	 * outstanding HTLCs, which allows a node to limit its exposure to
+	 * HTLCs */
 	u64 max_htlc_value_in_flight_msat;
+
+	/* BOLT #2:
+	 *
+	 * `channel_reserve_satoshis` is the minimum amount that the other
+	 * node is to keep as a direct payment. */
 	u64 channel_reserve_satoshis;
+
+	/* BOLT #2:
+	 *
+	 * `htlc_minimum_msat` indicates the smallest value HTLC this node
+	 * will accept.
+	 */
 	u64 htlc_minimum_msat;
+
+	/* BOLT #2:
+	 *
+	 * `to_self_delay` is the number of blocks that the other node's
+	 * to-self outputs must be delayed, using `OP_CHECKSEQUENCEVERIFY`
+	 * delays */
 	u16 to_self_delay;
+
+	/* BOLT #2:
+	 *
+	 * similarly, `max_accepted_htlcs` limits the number of outstanding
+	 * HTLCs the other node can offer. */
 	u16 max_accepted_htlcs;
 };
 

common/initial_channel.c

@@ -93,10 +93,11 @@ struct bitcoin_tx *initial_channel_tx(const tal_t *ctx,
 				 channel->funding_txout,
 				 channel->funding_msat / 1000,
 				 channel->funder,
-				 to_self_delay(channel, side),
+				 /* They specify our to_self_delay and v.v. */
+				 channel->config[!side]->to_self_delay,
 				 &keyset,
 				 channel->view[side].feerate_per_kw,
-				 dust_limit_satoshis(channel, side),
+				 channel->config[side]->dust_limit_satoshis,
 				 channel->view[side].owed_msat[side],
 				 channel->view[side].owed_msat[!side],
 				 channel_reserve_msat(channel, side),

common/initial_channel.h

@@ -62,68 +62,13 @@ struct channel {
 	const struct chainparams *chainparams;
 };
 
-/* Some requirements are self-specified (eg. my dust limit), others
+/* This side's reserve is specified by the *other* side, and in satoshis:
- * are force upon the other side (eg. minimum htlc you can add).
+ * this is a convenience function to convert it. */
- *
- * These values are also universally in msatsoshi.  These avoid
- * confusion: use them! */
-
-/* BOLT #2:
- *
- * `dust_limit_satoshis` is the threshold below which outputs should not be
- * generated for this node's commitment or HTLC transaction */
-static inline u64 dust_limit_satoshis(const struct channel *channel,
-				      enum side side)
-{
-	return channel->config[side]->dust_limit_satoshis;
-}
-/* BOLT #2:
- *
- * `max_htlc_value_in_flight_msat` is a cap on total value of
- * outstanding HTLCs, which allows a node to limit its exposure to
- * HTLCs */
-static inline u64 max_htlc_value_in_flight_msat(const struct channel *channel,
-						enum side recipient)
-{
-	return channel->config[recipient]->max_htlc_value_in_flight_msat;
-}
-/* BOLT #2:
- *
- * similarly, `max_accepted_htlcs` limits the number of outstanding
- * HTLCs the other node can offer. */
-static inline u16 max_accepted_htlcs(const struct channel *channel,
-				     enum side recipient)
-{
-	return channel->config[recipient]->max_accepted_htlcs;
-}
-/* BOLT #2:
- *
- * `channel_reserve_satoshis` is the minimum amount that the other
- * node is to keep as a direct payment. */
 static inline u64 channel_reserve_msat(const struct channel *channel,
 				       enum side side)
 {
 	return channel->config[!side]->channel_reserve_satoshis * 1000;
 }
-/* BOLT #2:
- *
- * `htlc_minimum_msat` indicates the smallest value HTLC this node will accept.
- */
-static inline u64 htlc_minimum_msat(const struct channel *channel,
-				    enum side recipient)
-{
-	return channel->config[recipient]->htlc_minimum_msat;
-}
-/* BOLT #2:
- *
- * `to_self_delay` is the number of blocks that the other node's
- * to-self outputs must be delayed, using `OP_CHECKSEQUENCEVERIFY`
- * delays */
-static inline u16 to_self_delay(const struct channel *channel, enum side side)
-{
-	return channel->config[!side]->to_self_delay;
-}
-
 
 /**
  * new_initial_channel: Given initial fees and funding, what is initial state?