df: rename 'funder' to 'opener'

Previously we've used the term 'funder' to refer to the peer
paying the fees for a transaction; v2 of openchannel will make
this no longer true. Instead we rename this to 'opener', or the
peer sending the 'open_channel' message, since this will be universally
true in a dual-funding world.

Author: niftynei

channeld/channel_wire.csv

@@ -22,7 +22,7 @@ msgdata,channel_init,remote_fundingkey,pubkey,
 msgdata,channel_init,remote_basepoints,basepoints,
 msgdata,channel_init,remote_per_commit,pubkey,
 msgdata,channel_init,old_remote_per_commit,pubkey,
-msgdata,channel_init,funder,enum side,
+msgdata,channel_init,opener,enum side,
 msgdata,channel_init,fee_base,u32,
 msgdata,channel_init,fee_proportional,u32,
 msgdata,channel_init,local_msatoshi,amount_msat,

channeld/channeld.c

@@ -669,10 +669,10 @@ static void handle_peer_feechange(struct peer *peer, const u8 *msg)
 	 *  - if the sender is not responsible for paying the Bitcoin fee:
 	 *    - MUST fail the channel.
 	 */
-	if (peer->channel->funder != REMOTE)
+	if (peer->channel->opener != REMOTE)
 		peer_failed(peer->pps,
 			    &peer->channel_id,
-			    "update_fee from non-funder?");
+			    "update_fee from non-opener?");
 
 	status_debug("update_fee %u, range %u-%u",
 		     feerate, peer->feerate_min, peer->feerate_max);
@@ -1128,7 +1128,7 @@ static void send_commit(struct peer *peer)
 	}
 
 	/* If we wanted to update fees, do it now. */
-	if (peer->channel->funder == LOCAL) {
+	if (peer->channel->opener == LOCAL) {
 		u32 feerate, max = approx_max_feerate(peer->channel);
 
 		feerate = peer->desired_feerate;
@@ -1386,11 +1386,11 @@ static void handle_peer_commit_sig(struct peer *peer, const u8 *msg)
 	}
 
 	/* We were supposed to check this was affordable as we go. */
-	if (peer->channel->funder == REMOTE) {
+	if (peer->channel->opener == REMOTE) {
 		status_debug("Feerates are %u/%u",
 			     peer->channel->view[LOCAL].feerate_per_kw,
 			     peer->channel->view[REMOTE].feerate_per_kw);
-		assert(can_funder_afford_feerate(peer->channel,
+		assert(can_opener_afford_feerate(peer->channel,
 						 peer->channel->view[LOCAL]
 						 .feerate_per_kw));
 	}
@@ -1584,7 +1584,7 @@ static void handle_peer_revoke_and_ack(struct peer *peer, const u8 *msg)
 	peer->old_remote_per_commit = peer->remote_per_commit;
 	peer->remote_per_commit = next_per_commit;
 	status_debug("revoke_and_ack %s: remote_per_commit = %s, old_remote_per_commit = %s",
-		     side_to_str(peer->channel->funder),
+		     side_to_str(peer->channel->opener),
 		     type_to_string(tmpctx, struct pubkey,
 				    &peer->remote_per_commit),
 		     type_to_string(tmpctx, struct pubkey,
@@ -1992,7 +1992,7 @@ static void resend_commitment(struct peer *peer, const struct changed_htlc *last
 	}
 
 	/* Make sure they have the correct fee. */
-	if (peer->channel->funder == LOCAL) {
+	if (peer->channel->opener == LOCAL) {
 		msg = towire_update_fee(NULL, &peer->channel_id,
 					channel_feerate(peer->channel, REMOTE));
 		sync_crypto_write(peer->pps, take(msg));
@@ -2519,7 +2519,7 @@ static void peer_reconnect(struct peer *peer,
 	 * even tell by seeing if fees are different (short of saving full fee
 	 * state in database) since it could be a tiny feechange, or two
 	 * feechanges which cancelled out. */
-	if (peer->channel->funder == LOCAL)
+	if (peer->channel->opener == LOCAL)
 		peer->channel->changes_pending[LOCAL] = true;
 
 	peer_billboard(true, "Reconnected, and reestablished.");
@@ -2687,7 +2687,7 @@ static void handle_feerates(struct peer *peer, const u8 *inmsg)
 	 *    sufficient (by a significant margin) for timely processing of the
 	 *     commitment transaction.
 	 */
-	if (peer->channel->funder == LOCAL) {
+	if (peer->channel->opener == LOCAL) {
 		peer->desired_feerate = feerate;
 		start_commit_timer(peer);
 	} else {
@@ -2921,7 +2921,7 @@ static void init_channel(struct peer *peer)
 	struct pubkey funding_pubkey[NUM_SIDES];
 	struct channel_config conf[NUM_SIDES];
 	struct bitcoin_txid funding_txid;
-	enum side funder;
+	enum side opener;
 	enum htlc_state *hstates;
 	struct fulfilled_htlc *fulfilled;
 	enum side *fulfilled_sides;
@@ -2957,7 +2957,7 @@ static void init_channel(struct peer *peer)
 				   &points[REMOTE],
 				   &peer->remote_per_commit,
 				   &peer->old_remote_per_commit,
-				   &funder,
+				   &opener,
 				   &peer->fee_base,
 				   &peer->fee_per_satoshi,
 				   &local_msat,
@@ -3007,7 +3007,7 @@ static void init_channel(struct peer *peer)
 		     " next_idx_remote = %"PRIu64
 		     " revocations_received = %"PRIu64
 		     " feerates %u/%u (range %u-%u)",
-		     side_to_str(funder),
+		     side_to_str(opener),
 		     type_to_string(tmpctx, struct pubkey,
 				    &peer->remote_per_commit),
 		     type_to_string(tmpctx, struct pubkey,
@@ -3055,7 +3055,7 @@ static void init_channel(struct peer *peer)
 					 &funding_pubkey[LOCAL],
 					 &funding_pubkey[REMOTE],
 					 option_static_remotekey,
-					 funder);
+					 opener);
 
 	if (!channel_force_htlcs(peer->channel, htlcs, hstates,
 				 fulfilled, fulfilled_sides,
@@ -3083,7 +3083,7 @@ static void init_channel(struct peer *peer)
 					      &peer->node_ids[REMOTE]);
 
 	/* Default desired feerate is the feerate we set for them last. */
-	if (peer->channel->funder == LOCAL)
+	if (peer->channel->opener == LOCAL)
 		peer->desired_feerate = feerate_per_kw[REMOTE];
 
 	/* from now we need keep watch over WIRE_CHANNEL_FUNDING_DEPTH */

channeld/commit_tx.c

@@ -80,7 +80,7 @@ struct bitcoin_tx *commit_tx(const tal_t *ctx,
 			     const struct bitcoin_txid *funding_txid,
 			     unsigned int funding_txout,
 			     struct amount_sat funding,
-			     enum side funder,
+			     enum side opener,
 			     u16 to_self_delay,
 			     const struct keyset *keyset,
 			     u32 feerate_per_kw,
@@ -126,7 +126,7 @@ struct bitcoin_tx *commit_tx(const tal_t *ctx,
 	 * 3. Subtract this base fee from the funder (either `to_local` or
 	 * `to_remote`), with a floor of 0 (see [Fee Payment](#fee-payment)).
 	 */
-	try_subtract_fee(funder, side, base_fee, &self_pay, &other_pay);
+	try_subtract_fee(opener, side, base_fee, &self_pay, &other_pay);
 
 #ifdef PRINT_ACTUAL_FEE
 	{

channeld/commit_tx.h

@@ -28,7 +28,7 @@ size_t commit_tx_num_untrimmed(const struct htlc **htlcs,
  * commit_tx: create (unsigned) commitment tx to spend the funding tx output
  * @ctx: context to allocate transaction and @htlc_map from.
  * @funding_txid, @funding_out, @funding: funding outpoint.
- * @funder: is the LOCAL or REMOTE paying the fee?
+ * @opener: is the LOCAL or REMOTE paying the fee?
  * @keyset: keys derived for this commit tx.
  * @feerate_per_kw: feerate to use
  * @dust_limit: dust limit below which to trim outputs.
@@ -48,7 +48,7 @@ struct bitcoin_tx *commit_tx(const tal_t *ctx,
 			     const struct bitcoin_txid *funding_txid,
 			     unsigned int funding_txout,
 			     struct amount_sat funding,
-			     enum side funder,
+			     enum side opener,
 			     u16 to_self_delay,
 			     const struct keyset *keyset,
 			     u32 feerate_per_kw,

channeld/full_channel.c

@@ -47,7 +47,7 @@ struct channel *new_full_channel(const tal_t *ctx,
 				 const struct pubkey *local_funding_pubkey,
 				 const struct pubkey *remote_funding_pubkey,
 				 bool option_static_remotekey,
-				 enum side funder)
+				 enum side opener)
 {
 	struct channel *channel = new_initial_channel(ctx,
 						      chain_hash,
@@ -63,7 +63,7 @@ struct channel *new_full_channel(const tal_t *ctx,
 						      local_funding_pubkey,
 						      remote_funding_pubkey,
 						      option_static_remotekey,
-						      funder);
+						      opener);
 
 	if (channel) {
 		/* Feerates can be different. */
@@ -283,7 +283,7 @@ struct bitcoin_tx **channel_txs(const tal_t *ctx,
 	txs = tal_arr(ctx, struct bitcoin_tx *, 1);
 	txs[0] = commit_tx(
 	    ctx, chainparams, &channel->funding_txid, channel->funding_txout,
-	    channel->funding, channel->funder,
+	    channel->funding, channel->opener,
 	    channel->config[!side].to_self_delay, &keyset,
 	    channel->view[side].feerate_per_kw,
 	    channel->config[side].dust_limit, channel->view[side].owed[side],
@@ -459,7 +459,7 @@ static enum channel_add_err add_htlc(struct channel *channel,
 	 */
 	/* Also we should not add more htlc's than sender or recipient
 	 * configured.  This mitigates attacks in which a peer can force the
-	 * funder of the channel to pay unnecessary onchain fees during a fee
+	 * opener of the channel to pay unnecessary onchain fees during a fee
 	 * spike with large commitment transactions.
 	 */
 	min_concurrent_htlcs = channel->config[recipient].max_accepted_htlcs;
@@ -533,7 +533,7 @@ static enum channel_add_err add_htlc(struct channel *channel,
 					    &balance))
 			return CHANNEL_ERR_CHANNEL_CAPACITY_EXCEEDED;
 
-		if (channel->funder == sender) {
+		if (channel->opener == sender) {
 			if (amount_msat_less_sat(balance, fee)) {
 				status_debug("Cannot afford fee %s with %s above reserve",
 					     type_to_string(tmpctx, struct amount_sat,
@@ -544,12 +544,12 @@ static enum channel_add_err add_htlc(struct channel *channel,
 			}
 		}
 
-		/* Try not to add a payment which will take funder into fees
+		/* Try not to add a payment which will take opener into fees
 		 * on either our side or theirs. */
 		if (sender == LOCAL) {
 			if (!get_room_above_reserve(channel, view,
 						    adding, removing,
-						    channel->funder,
+						    channel->opener,
 						    &balance))
 				return CHANNEL_ERR_CHANNEL_CAPACITY_EXCEEDED;
 			/* Should be able to afford both their own commit tx
@@ -559,7 +559,7 @@ static enum channel_add_err add_htlc(struct channel *channel,
 					    committed,
 					    adding,
 					    removing,
-					    channel->funder);
+					    channel->opener);
 			/* set fee output pointer if given */
 			if (htlc_fee && amount_sat_greater(fee, *htlc_fee))
 				*htlc_fee = fee;
@@ -577,7 +577,7 @@ static enum channel_add_err add_htlc(struct channel *channel,
 					    committed,
 					    adding,
 					    removing,
-					    !channel->funder);
+					    !channel->opener);
 			/* set fee output pointer if given */
 			if (htlc_fee && amount_sat_greater(fee, *htlc_fee))
 				*htlc_fee = fee;
@@ -873,7 +873,7 @@ u32 approx_max_feerate(const struct channel *channel)
 	struct amount_sat avail;
 	const struct htlc **committed, **adding, **removing;
 
-	gather_htlcs(tmpctx, channel, !channel->funder,
+	gather_htlcs(tmpctx, channel, !channel->opener,
 		     &committed, &removing, &adding);
 
 	/* Assume none are trimmed; this gives lower bound on feerate. */
@@ -883,28 +883,28 @@ u32 approx_max_feerate(const struct channel *channel)
 
 	/* We should never go below reserve. */
 	if (!amount_sat_sub(&avail,
-			    amount_msat_to_sat_round_down(channel->view[!channel->funder].owed[channel->funder]),
-			    channel->config[!channel->funder].channel_reserve))
+			    amount_msat_to_sat_round_down(channel->view[!channel->opener].owed[channel->opener]),
+			    channel->config[!channel->opener].channel_reserve))
 		avail = AMOUNT_SAT(0);
 
 	return avail.satoshis / weight * 1000; /* Raw: once-off reverse feerate*/
 }
 
-bool can_funder_afford_feerate(const struct channel *channel, u32 feerate_per_kw)
+bool can_opener_afford_feerate(const struct channel *channel, u32 feerate_per_kw)
 {
 	struct amount_sat needed, fee;
-	struct amount_sat dust_limit = channel->config[!channel->funder].dust_limit;
+	struct amount_sat dust_limit = channel->config[!channel->opener].dust_limit;
 	size_t untrimmed;
 	const struct htlc **committed, **adding, **removing;
-	gather_htlcs(tmpctx, channel, !channel->funder,
+	gather_htlcs(tmpctx, channel, !channel->opener,
 		     &committed, &removing, &adding);
 
 	untrimmed = commit_tx_num_untrimmed(committed, feerate_per_kw, dust_limit,
-					    !channel->funder)
+					    !channel->opener)
 			+ commit_tx_num_untrimmed(adding, feerate_per_kw, dust_limit,
-						  !channel->funder)
+						  !channel->opener)
 			- commit_tx_num_untrimmed(removing, feerate_per_kw, dust_limit,
-						  !channel->funder);
+						  !channel->opener);
 
 	fee = commit_tx_base_fee(feerate_per_kw, untrimmed);
 
@@ -914,39 +914,39 @@ bool can_funder_afford_feerate(const struct channel *channel, u32 feerate_per_kw
 	 *     node's current commitment transaction:
 	 *     - SHOULD fail the channel
 	 */
-	/* Note: sender == funder */
+	/* Note: sender == opener */
 
 	/* How much does it think it has?  Must be >= reserve + fee */
 	if (!amount_sat_add(&needed, fee,
-			    channel->config[!channel->funder].channel_reserve))
+			    channel->config[!channel->opener].channel_reserve))
 		status_failed(STATUS_FAIL_INTERNAL_ERROR,
 			      "Cannot add fee %s and reserve %s",
 			      type_to_string(tmpctx, struct amount_sat,
 					     &fee),
 			      type_to_string(tmpctx, struct amount_sat,
-					     &channel->config[!channel->funder].channel_reserve));
+					     &channel->config[!channel->opener].channel_reserve));
 
 	status_debug("We need %s at feerate %u for %zu untrimmed htlcs: we have %s/%s",
 		     type_to_string(tmpctx, struct amount_sat, &needed),
 		     feerate_per_kw, untrimmed,
 		     type_to_string(tmpctx, struct amount_msat,
-				    &channel->view[LOCAL].owed[channel->funder]),
+				    &channel->view[LOCAL].owed[channel->opener]),
 		     type_to_string(tmpctx, struct amount_msat,
-				    &channel->view[REMOTE].owed[channel->funder]));
-	return amount_msat_greater_eq_sat(channel->view[!channel->funder].owed[channel->funder],
+				    &channel->view[REMOTE].owed[channel->opener]));
+	return amount_msat_greater_eq_sat(channel->view[!channel->opener].owed[channel->opener],
 					  needed);
 }
 
 bool channel_update_feerate(struct channel *channel, u32 feerate_per_kw)
 {
-	if (!can_funder_afford_feerate(channel, feerate_per_kw))
+	if (!can_opener_afford_feerate(channel, feerate_per_kw))
 		return false;
 
 	status_debug("Setting %s feerate to %u",
-		     side_to_str(!channel->funder), feerate_per_kw);
+		     side_to_str(!channel->opener), feerate_per_kw);
 
-	channel->view[!channel->funder].feerate_per_kw = feerate_per_kw;
-	channel->changes_pending[!channel->funder] = true;
+	channel->view[!channel->opener].feerate_per_kw = feerate_per_kw;
+	channel->changes_pending[!channel->opener] = true;
 	return true;
 }
 
@@ -994,8 +994,8 @@ bool channel_rcvd_revoke_and_ack(struct channel *channel,
 	if (change & HTLC_LOCAL_F_PENDING)
 		channel->changes_pending[LOCAL] = true;
 
-	/* For funder, ack also means time to apply new feerate locally. */
-	if (channel->funder == LOCAL &&
+	/* For opener, ack also means time to apply new feerate locally. */
+	if (channel->opener == LOCAL &&
 	    (channel->view[LOCAL].feerate_per_kw
 	     != channel->view[REMOTE].feerate_per_kw)) {
 		status_debug("Applying feerate %u to LOCAL",
@@ -1045,8 +1045,8 @@ bool channel_sending_revoke_and_ack(struct channel *channel)
 	if (change & HTLC_REMOTE_F_PENDING)
 		channel->changes_pending[REMOTE] = true;
 
-	/* For non-funder, sending ack means we apply any fund changes to them */
-	if (channel->funder == REMOTE
+	/* For non-opener, sending ack means we apply any fund changes to them */
+	if (channel->opener == REMOTE
 	    && (channel->view[LOCAL].feerate_per_kw
 		!= channel->view[REMOTE].feerate_per_kw)) {
 		status_debug("Applying feerate %u to REMOTE",