Expose onion_message items directly rather than via re-exports

When we originally added the `onion_message` module, there weren't
a lot of public items in it, and it didn't make a lot of sense to
export the whole sub-module structure publicly. So, instead, we
exported the public items via re-exports directly in the
`onion_message` top-level module. However, as time went on, more
and more things entered the module, which left the top-level module
rather cluttered.

Worse, in 0.0.119, we exposed
`onion_message::messenger::SendSuccess` via the return type of
`send_message`, but forgot to re-export the enum itself, making
it impossible to actually use from external code.

Here we address both issues and simply replace the re-export with
the underlying sub-module structure.

lightning/src/blinded_path/message.rs

@@ -5,7 +5,7 @@ use crate::blinded_path::utils;
 use crate::io;
 use crate::io::Cursor;
 use crate::ln::onion_utils;
-use crate::onion_message::ControlTlvs;
+use crate::onion_message::packet::ControlTlvs;
 use crate::prelude::*;
 use crate::sign::{NodeSigner, Recipient};
 use crate::util::chacha20poly1305rfc::ChaChaPolyReadAdapter;

lightning/src/blinded_path/utils.rs

@@ -18,7 +18,7 @@ use bitcoin::secp256k1::ecdh::SharedSecret;
 use super::{BlindedHop, BlindedPath};
 use crate::ln::msgs::DecodeError;
 use crate::ln::onion_utils;
-use crate::onion_message::Destination;
+use crate::onion_message::messenger::Destination;
 use crate::util::chacha20poly1305rfc::ChaChaPolyWriteAdapter;
 use crate::util::ser::{Readable, Writeable};
 

lightning/src/events/mod.rs

@@ -540,8 +540,8 @@ pub enum Event {
 	/// replies. Handlers should connect to the node otherwise any buffered messages may be lost.
 	///
 	/// [`OnionMessage`]: msgs::OnionMessage
-	/// [`MessageRouter`]: crate::onion_message::MessageRouter
-	/// [`Destination`]: crate::onion_message::Destination
+	/// [`MessageRouter`]: crate::onion_message::messenger::MessageRouter
+	/// [`Destination`]: crate::onion_message::messenger::Destination
 	/// [`OnionMessageHandler`]: crate::ln::msgs::OnionMessageHandler
 	ConnectionNeeded {
 		/// The node id for the node needing a connection.

lightning/src/ln/channelmanager.rs

@@ -63,7 +63,8 @@ use crate::offers::merkle::SignError;
 use crate::offers::offer::{DerivedMetadata, Offer, OfferBuilder};
 use crate::offers::parse::Bolt12SemanticError;
 use crate::offers::refund::{Refund, RefundBuilder};
-use crate::onion_message::{Destination, MessageRouter, OffersMessage, OffersMessageHandler, PendingOnionMessage, new_pending_onion_message};
+use crate::onion_message::messenger::{Destination, MessageRouter, PendingOnionMessage, new_pending_onion_message};
+use crate::onion_message::offers::{OffersMessage, OffersMessageHandler};
 use crate::sign::{EntropySource, NodeSigner, Recipient, SignerProvider};
 use crate::sign::ecdsa::WriteableEcdsaChannelSigner;
 use crate::util::config::{UserConfig, ChannelConfig, ChannelConfigUpdate};

lightning/src/ln/msgs.rs

@@ -695,7 +695,7 @@ pub struct OnionMessage {
 	/// Used in decrypting the onion packet's payload.
 	pub blinding_point: PublicKey,
 	/// The full onion packet including hop data, pubkey, and hmac
-	pub onion_routing_packet: onion_message::Packet,
+	pub onion_routing_packet: onion_message::packet::Packet,
 }
 
 /// An [`update_fulfill_htlc`] message to be sent to or received from a peer.
@@ -2245,7 +2245,8 @@ impl Readable for OnionMessage {
 		let blinding_point: PublicKey = Readable::read(r)?;
 		let len: u16 = Readable::read(r)?;
 		let mut packet_reader = FixedLengthReader::new(r, len as u64);
-		let onion_routing_packet: onion_message::Packet = <onion_message::Packet as LengthReadable>::read(&mut packet_reader)?;
+		let onion_routing_packet: onion_message::packet::Packet =
+			<onion_message::packet::Packet as LengthReadable>::read(&mut packet_reader)?;
 		Ok(Self {
 			blinding_point,
 			onion_routing_packet,

lightning/src/ln/peer_handler.rs

@@ -31,8 +31,10 @@ use crate::ln::peer_channel_encryptor::{PeerChannelEncryptor, NextNoiseStep, Mes
 use crate::ln::wire;
 use crate::ln::wire::{Encode, Type};
 #[cfg(not(c_bindings))]
-use crate::onion_message::{SimpleArcOnionMessenger, SimpleRefOnionMessenger};
-use crate::onion_message::{CustomOnionMessageHandler, OffersMessage, OffersMessageHandler, OnionMessageContents, PendingOnionMessage};
+use crate::onion_message::messenger::{SimpleArcOnionMessenger, SimpleRefOnionMessenger};
+use crate::onion_message::messenger::{CustomOnionMessageHandler, PendingOnionMessage};
+use crate::onion_message::packet::OnionMessageContents;
+use crate::onion_message::offers::{OffersMessage, OffersMessageHandler};
 use crate::routing::gossip::{NodeId, NodeAlias};
 use crate::util::atomic_counter::AtomicCounter;
 use crate::util::logger::{Logger, WithContext};
@@ -384,7 +386,7 @@ pub struct MessageHandler<CM: Deref, RM: Deref, OM: Deref, CustomM: Deref> where
 	/// A message handler which handles onion messages. This should generally be an
 	/// [`OnionMessenger`], but can also be an [`IgnoringMessageHandler`].
 	///
-	/// [`OnionMessenger`]: crate::onion_message::OnionMessenger
+	/// [`OnionMessenger`]: crate::onion_message::messenger::OnionMessenger
 	pub onion_message_handler: OM,
 
 	/// A message handler which handles custom messages. The only LDK-provided implementation is

lightning/src/onion_message/functional_tests.rs

@@ -16,7 +16,9 @@ use crate::ln::msgs::{self, DecodeError, OnionMessageHandler, SocketAddress};
 use crate::sign::{EntropySource, NodeSigner, Recipient};
 use crate::util::ser::{FixedLengthReader, LengthReadable, Writeable, Writer};
 use crate::util::test_utils;
-use super::{CustomOnionMessageHandler, Destination, MessageRouter, OffersMessage, OffersMessageHandler, OnionMessageContents, OnionMessagePath, OnionMessenger, PendingOnionMessage, SendError};
+use super::packet::{OnionMessageContents, Packet};
+use super::messenger::{CustomOnionMessageHandler, Destination, MessageRouter, OnionMessagePath, OnionMessenger, PendingOnionMessage, SendError};
+use super::offers::{OffersMessage, OffersMessageHandler};
 
 use bitcoin::network::constants::Network;
 use bitcoin::hashes::hex::FromHex;
@@ -571,8 +573,8 @@ fn spec_test_vector() {
 	let sender_to_alice_packet_bytes_len = sender_to_alice_packet_bytes.len() as u64;
 	let mut reader = io::Cursor::new(sender_to_alice_packet_bytes);
 	let mut packet_reader = FixedLengthReader::new(&mut reader, sender_to_alice_packet_bytes_len);
-	let sender_to_alice_packet: super::Packet =
-		<super::Packet as LengthReadable>::read(&mut packet_reader).unwrap();
+	let sender_to_alice_packet: Packet =
+		<Packet as LengthReadable>::read(&mut packet_reader).unwrap();
 	let secp_ctx = Secp256k1::new();
 	let sender_to_alice_om = msgs::OnionMessage {
 		blinding_point: PublicKey::from_secret_key(&secp_ctx, &SecretKey::from_slice(&<Vec<u8>>::from_hex("6363636363636363636363636363636363636363636363636363636363636363").unwrap()).unwrap()),

lightning/src/onion_message/messenger.rs

@@ -7,8 +7,8 @@
 // You may not use this file except in accordance with one or both of these
 // licenses.
 
-//! LDK sends, receives, and forwards onion messages via the [`OnionMessenger`]. See its docs for
-//! more information.
+//! LDK sends, receives, and forwards onion messages via this [`OnionMessenger`], which lives here,
+//! as well as various types, traits, and utilities which it uses.
 
 use bitcoin::hashes::{Hash, HashEngine};
 use bitcoin::hashes::hmac::{Hmac, HmacEngine};
@@ -26,7 +26,7 @@ use crate::ln::features::{InitFeatures, NodeFeatures};
 use crate::ln::msgs::{self, OnionMessage, OnionMessageHandler, SocketAddress};
 use crate::ln::onion_utils;
 use crate::routing::gossip::{NetworkGraph, NodeId};
-pub use super::packet::OnionMessageContents;
+use super::packet::OnionMessageContents;
 use super::packet::ParsedOnionMessageContents;
 use super::offers::OffersMessageHandler;
 use super::packet::{BIG_PACKET_HOP_DATA_LEN, ForwardControlTlvs, Packet, Payload, ReceiveControlTlvs, SMALL_PACKET_HOP_DATA_LEN};
@@ -74,7 +74,8 @@ pub(super) const MAX_TIMER_TICKS: usize = 2;
 /// # use lightning::blinded_path::BlindedPath;
 /// # use lightning::sign::{EntropySource, KeysManager};
 /// # use lightning::ln::peer_handler::IgnoringMessageHandler;
-/// # use lightning::onion_message::{OnionMessageContents, Destination, MessageRouter, OnionMessagePath, OnionMessenger};
+/// # use lightning::onion_message::messenger::{Destination, MessageRouter, OnionMessagePath, OnionMessenger};
+/// # use lightning::onion_message::packet::OnionMessageContents;
 /// # use lightning::util::logger::{Logger, Record};
 /// # use lightning::util::ser::{Writeable, Writer};
 /// # use lightning::io;

lightning/src/onion_message/mod.rs

@@ -19,19 +19,10 @@
 //!
 //! [offers]: <https://github.com/lightning/bolts/pull/798>
 //! [blinded paths]: crate::blinded_path::BlindedPath
+//! [`OnionMessenger`]: self::messenger::OnionMessenger
 
-mod messenger;
-mod offers;
-mod packet;
+pub mod messenger;
+pub mod offers;
+pub mod packet;
 #[cfg(test)]
 mod functional_tests;
-
-// Re-export structs so they can be imported with just the `onion_message::` module prefix.
-pub use self::messenger::{CustomOnionMessageHandler, DefaultMessageRouter, Destination, MessageRouter, OnionMessageContents, OnionMessagePath, OnionMessenger, PeeledOnion, PendingOnionMessage, SendError};
-pub use self::messenger::{create_onion_message, peel_onion_message};
-#[cfg(not(c_bindings))]
-pub use self::messenger::{SimpleArcOnionMessenger, SimpleRefOnionMessenger};
-pub use self::offers::{OffersMessage, OffersMessageHandler};
-pub use self::packet::{Packet, ParsedOnionMessageContents};
-pub(crate) use self::packet::ControlTlvs;
-pub(crate) use self::messenger::new_pending_onion_message;

lightning/src/onion_message/offers.rs

@@ -17,7 +17,7 @@ use crate::offers::invoice_error::InvoiceError;
 use crate::offers::invoice_request::InvoiceRequest;
 use crate::offers::invoice::Bolt12Invoice;
 use crate::offers::parse::Bolt12ParseError;
-use crate::onion_message::OnionMessageContents;
+use crate::onion_message::packet::OnionMessageContents;
 use crate::util::logger::Logger;
 use crate::util::ser::{Readable, ReadableArgs, Writeable, Writer};
 #[cfg(not(c_bindings))]
@@ -39,7 +39,7 @@ pub trait OffersMessageHandler {
 	///
 	/// The returned [`OffersMessage`], if any, is enqueued to be sent by [`OnionMessenger`].
 	///
-	/// [`OnionMessenger`]: crate::onion_message::OnionMessenger
+	/// [`OnionMessenger`]: crate::onion_message::messenger::OnionMessenger
 	fn handle_message(&self, message: OffersMessage) -> Option<OffersMessage>;
 
 	/// Releases any [`OffersMessage`]s that need to be sent.
@@ -54,7 +54,7 @@ pub trait OffersMessageHandler {
 	/// Typically, this is used for messages initiating a payment flow rather than in response to
 	/// another message. The latter should use the return value of [`Self::handle_message`].
 	#[cfg(c_bindings)]
-	fn release_pending_messages(&self) -> Vec<(OffersMessage, crate::onion_message::Destination, Option<crate::blinded_path::BlindedPath>)> { vec![] }
+	fn release_pending_messages(&self) -> Vec<(OffersMessage, crate::onion_message::messenger::Destination, Option<crate::blinded_path::BlindedPath>)> { vec![] }
 }
 
 /// Possible BOLT 12 Offers messages sent and received via an [`OnionMessage`].

lightning/src/routing/router.rs

@@ -20,7 +20,7 @@ use crate::ln::channelmanager::{ChannelDetails, PaymentId};
 use crate::ln::features::{BlindedHopFeatures, Bolt11InvoiceFeatures, Bolt12InvoiceFeatures, ChannelFeatures, NodeFeatures};
 use crate::ln::msgs::{DecodeError, ErrorAction, LightningError, MAX_VALUE_MSAT};
 use crate::offers::invoice::{BlindedPayInfo, Bolt12Invoice};
-use crate::onion_message::{DefaultMessageRouter, Destination, MessageRouter, OnionMessagePath};
+use crate::onion_message::messenger::{DefaultMessageRouter, Destination, MessageRouter, OnionMessagePath};
 use crate::routing::gossip::{DirectedChannelInfo, EffectiveCapacity, ReadOnlyNetworkGraph, NetworkGraph, NodeId, RoutingFees};
 use crate::routing::scoring::{ChannelUsage, LockableScore, ScoreLookUp};
 use crate::sign::EntropySource;

lightning/src/util/test_utils.rs

@@ -32,7 +32,7 @@ use crate::ln::msgs::LightningError;
 use crate::ln::script::ShutdownScript;
 use crate::offers::invoice::{BlindedPayInfo, UnsignedBolt12Invoice};
 use crate::offers::invoice_request::UnsignedInvoiceRequest;
-use crate::onion_message::{Destination, MessageRouter, OnionMessagePath};
+use crate::onion_message::messenger::{Destination, MessageRouter, OnionMessagePath};
 use crate::routing::gossip::{EffectiveCapacity, NetworkGraph, NodeId, RoutingFees};
 use crate::routing::utxo::{UtxoLookup, UtxoLookupError, UtxoResult};
 use crate::routing::router::{find_route, InFlightHtlcs, Path, Route, RouteParameters, RouteHintHop, Router, ScorerAccountingForInFlightHtlcs};