common: remove onionreply type from sphinx.c

It's only mildly used, and I really to use onionreply in a more
generic sense in the next patch.

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

common/sphinx.c

@@ -604,12 +604,12 @@ u8 *wrap_onionreply(const tal_t *ctx,
 	return result;
 }
 
-struct onionreply *unwrap_onionreply(const tal_t *ctx,
-				     const struct secret *shared_secrets,
-				     const int numhops, const u8 *reply)
+u8 *unwrap_onionreply(const tal_t *ctx,
+		      const struct secret *shared_secrets,
+		      const int numhops, const u8 *reply,
+		      int *origin_index)
 {
-	struct onionreply *oreply = tal(tmpctx, struct onionreply);
-	u8 *msg = tal_arr(oreply, u8, tal_count(reply));
+	u8 *msg = tal_arr(tmpctx, u8, tal_count(reply)), *final;
 	u8 key[KEY_LEN], hmac[HMAC_SIZE];
 	const u8 *cursor;
 	size_t max;
@@ -620,7 +620,7 @@ struct onionreply *unwrap_onionreply(const tal_t *ctx,
 	}
 
 	memcpy(msg, reply, tal_count(reply));
-	oreply->origin_index = -1;
+	*origin_index = -1;
 
 	for (int i = 0; i < numhops; i++) {
 		/* Since the encryption is just XORing with the cipher
@@ -633,11 +633,11 @@ struct onionreply *unwrap_onionreply(const tal_t *ctx,
 		compute_hmac(hmac, msg + sizeof(hmac),
 			     tal_count(msg) - sizeof(hmac), key, KEY_LEN);
 		if (memcmp(hmac, msg, sizeof(hmac)) == 0) {
-			oreply->origin_index = i;
+			*origin_index = i;
 			break;
 		}
 	}
-	if (oreply->origin_index == -1) {
+	if (*origin_index == -1) {
 		return NULL;
 	}
 
@@ -649,10 +649,8 @@ struct onionreply *unwrap_onionreply(const tal_t *ctx,
 		return NULL;
 	}
 
-	oreply->msg = tal_arr(oreply, u8, msglen);
-	fromwire(&cursor, &max, oreply->msg, msglen);
-
-	tal_steal(ctx, oreply);
-	return oreply;
+	final = tal_arr(ctx, u8, msglen);
+	fromwire(&cursor, &max, final, msglen);
 
+	return final;
 }

common/sphinx.h

@@ -156,12 +156,6 @@ enum onion_type parse_onionpacket(const u8 *src,
 				  const size_t srclen,
 				  struct onionpacket *dest);
 
-struct onionreply {
-	/* Node index in the path that is replying */
-	int origin_index;
-	u8 *msg;
-};
-
 /**
  * create_onionreply - Format a failure message so we can return it
  *
@@ -191,10 +185,12 @@ u8 *wrap_onionreply(const tal_t *ctx, const struct secret *shared_secret,
  * @shared_secrets: shared secrets from the forward path
  * @numhops: path length and number of shared_secrets provided
  * @reply: the incoming reply
+ * @origin_index: the index in the path where the reply came from (-1 if unknown)
  */
-struct onionreply *unwrap_onionreply(const tal_t *ctx,
-				     const struct secret *shared_secrets,
-				     const int numhops, const u8 *reply);
+u8 *unwrap_onionreply(const tal_t *ctx,
+		      const struct secret *shared_secrets,
+		      const int numhops, const u8 *reply,
+		      int *origin_index);
 
 /**
  * Create a new empty sphinx_path.

common/test/run-sphinx.c

@@ -60,7 +60,8 @@ static struct secret secret_from_hex(const char *hex)
  * we match the test vectors and that we can also unwrap it. */
 static void run_unit_tests(void)
 {
-	struct onionreply *oreply;
+	u8 *oreply;
+	int origin_index;
 	u8 *reply;
 	u8 *raw = tal_hexdata(tmpctx, "2002", 4);
 
@@ -163,9 +164,10 @@ static void run_unit_tests(void)
 		assert(memcmp(reply, intermediates[i], tal_count(reply)) == 0);
 	}
 
-	oreply = unwrap_onionreply(tmpctx, ss, 5, reply);
-	printf("unwrapped %s\n", tal_hex(tmpctx, oreply->msg));
-	assert(memcmp(raw, oreply->msg, tal_bytelen(raw)) == 0);
+	oreply = unwrap_onionreply(tmpctx, ss, 5, reply, &origin_index);
+	printf("unwrapped %s\n", tal_hex(tmpctx, oreply));
+	assert(memeq(raw, tal_bytelen(raw), oreply, tal_bytelen(oreply)));
+	assert(origin_index == 4);
 }
 
 int main(int argc, char **argv)

lightningd/pay.c

@@ -373,23 +373,22 @@ static struct routing_failure*
 remote_routing_failure(const tal_t *ctx,
 		       struct lightningd *ld,
 		       const struct wallet_payment *payment,
-		       const struct onionreply *failure,
+		       const u8 *failuremsg,
+		       int origin_index,
 		       struct log *log,
 		       int *pay_errcode)
 {
-	enum onion_type failcode = fromwire_peektype(failure->msg);
+	enum onion_type failcode = fromwire_peektype(failuremsg);
 	struct routing_failure *routing_failure;
 	const struct node_id *route_nodes;
 	const struct node_id *erring_node;
 	const struct short_channel_id *route_channels;
 	const struct short_channel_id *erring_channel;
-	int origin_index;
 	int dir;
 
 	routing_failure = tal(ctx, struct routing_failure);
 	route_nodes = payment->route_nodes;
 	route_channels = payment->route_channels;
-	origin_index = failure->origin_index;
 
 	assert(route_nodes == NULL || origin_index < tal_count(route_nodes));
 
@@ -448,7 +447,7 @@ remote_routing_failure(const tal_t *ctx,
 		 * following node. */
 		if (failcode & BADONION) {
 			log_debug(log, "failcode %u from onionreply %s",
-				  failcode, tal_hex(tmpctx, failure->msg));
+				  failcode, tal_hex(tmpctx, failuremsg));
 			erring_node = &route_nodes[origin_index + 1];
 		} else
 			erring_node = &route_nodes[origin_index];
@@ -460,14 +459,14 @@ remote_routing_failure(const tal_t *ctx,
 							   erring_node,
 							   erring_channel,
 							   dir,
-							   failure->msg);
+							   failuremsg);
 		subd_send_msg(ld->gossip, take(gossip_msg));
 	}
 
 	routing_failure->erring_index = (unsigned int) (origin_index + 1);
 	routing_failure->failcode = failcode;
-	routing_failure->msg = tal_dup_arr(routing_failure, u8, failure->msg,
-					   tal_count(failure->msg), 0);
+	routing_failure->msg = tal_dup_arr(routing_failure, u8, failuremsg,
+					   tal_count(failuremsg), 0);
 
 	if (erring_node != NULL)
 		routing_failure->erring_node =
@@ -557,11 +556,12 @@ void payment_failed(struct lightningd *ld, const struct htlc_out *hout,
 		failmsg = "reply from remote";
 		/* Try to parse reply. */
 		struct secret *path_secrets = payment->path_secrets;
-		struct onionreply *reply;
+		u8 *reply;
+		int origin_index;
 
 		reply = unwrap_onionreply(tmpctx, path_secrets,
 					  tal_count(path_secrets),
-					  hout->failuremsg);
+					  hout->failuremsg, &origin_index);
 		if (!reply) {
 			log_info(hout->key.channel->log,
 				 "htlc %"PRIu64" failed with bad reply (%s)",
@@ -571,18 +571,19 @@ void payment_failed(struct lightningd *ld, const struct htlc_out *hout,
 			fail = NULL;
 			pay_errcode = PAY_UNPARSEABLE_ONION;
 		} else {
-			enum onion_type failcode = fromwire_peektype(reply->msg);
+			enum onion_type failcode = fromwire_peektype(reply);
 			log_info(hout->key.channel->log,
 				 "htlc %"PRIu64" "
 				 "failed from %ith node "
 				 "with code 0x%04x (%s)",
 				 hout->key.id,
-				 reply->origin_index,
+				 origin_index,
 				 failcode, onion_type_name(failcode));
 			log_debug(hout->key.channel->log, "failmsg: %s",
-				  tal_hex(tmpctx, reply->msg));
+				  tal_hex(tmpctx, reply));
 			fail = remote_routing_failure(tmpctx, ld,
 						      payment, reply,
+						      origin_index,
 						      hout->key.channel->log,
 						      &pay_errcode);
 		}