Make HTLCDescriptor writeable
[rust-lightning] / lightning / src / onion_message / packet.rs
index 41b8a1634f6bcf68147e15e301c72515a543004f..a76371b39eb9fa12769e2144fb6cdd02067b70f7 100644 (file)
 use bitcoin::secp256k1::PublicKey;
 use bitcoin::secp256k1::ecdh::SharedSecret;
 
-use ln::msgs::DecodeError;
-use ln::onion_utils;
-use super::blinded_route::{BlindedRoute, ForwardTlvs, ReceiveTlvs};
-use util::chacha20poly1305rfc::{ChaChaPolyReadAdapter, ChaChaPolyWriteAdapter};
-use util::ser::{BigSize, FixedLengthReader, LengthRead, LengthReadable, LengthReadableArgs, MaybeReadableArgs, Readable, ReadableArgs, Writeable, Writer};
+use crate::blinded_path::BlindedPath;
+use crate::blinded_path::message::{ForwardTlvs, ReceiveTlvs};
+use crate::blinded_path::utils::Padding;
+use crate::ln::msgs::DecodeError;
+use crate::ln::onion_utils;
+use super::messenger::CustomOnionMessageHandler;
+use super::offers::OffersMessage;
+use crate::util::chacha20poly1305rfc::{ChaChaPolyReadAdapter, ChaChaPolyWriteAdapter};
+use crate::util::logger::Logger;
+use crate::util::ser::{BigSize, FixedLengthReader, LengthRead, LengthReadable, LengthReadableArgs, Readable, ReadableArgs, Writeable, Writer};
 
 use core::cmp;
-use io::{self, Read};
-use prelude::*;
+use crate::io::{self, Read};
+use crate::prelude::*;
 
 // Per the spec, an onion message packet's `hop_data` field length should be
 // SMALL_PACKET_HOP_DATA_LEN if it fits, else BIG_PACKET_HOP_DATA_LEN if it fits.
@@ -98,7 +103,7 @@ pub(super) enum Payload<T: CustomOnionMessageContents> {
        /// This payload is for the final hop.
        Receive {
                control_tlvs: ReceiveControlTlvs,
-               reply_path: Option<BlindedRoute>,
+               reply_path: Option<BlindedPath>,
                message: OnionMessageContents<T>,
        }
 }
@@ -106,47 +111,50 @@ pub(super) enum Payload<T: CustomOnionMessageContents> {
 #[derive(Debug)]
 /// The contents of an onion message. In the context of offers, this would be the invoice, invoice
 /// request, or invoice error.
-pub enum OnionMessageContents<T> where T: CustomOnionMessageContents {
-       // Coming soon:
-       // Invoice,
-       // InvoiceRequest,
-       // InvoiceError,
+pub enum OnionMessageContents<T: CustomOnionMessageContents> {
+       /// A message related to BOLT 12 Offers.
+       Offers(OffersMessage),
        /// A custom onion message specified by the user.
        Custom(T),
 }
 
-impl<T> OnionMessageContents<T> where T: CustomOnionMessageContents {
+impl<T: CustomOnionMessageContents> OnionMessageContents<T> {
        /// Returns the type that was used to decode the message payload.
+       ///
+       /// This is not exported to bindings users as methods on non-cloneable enums are not currently exportable
        pub fn tlv_type(&self) -> u64 {
                match self {
+                       &OnionMessageContents::Offers(ref msg) => msg.tlv_type(),
                        &OnionMessageContents::Custom(ref msg) => msg.tlv_type(),
                }
        }
 }
 
+/// This is not exported to bindings users as methods on non-cloneable enums are not currently exportable
 impl<T: CustomOnionMessageContents> Writeable for OnionMessageContents<T> {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                match self {
+                       OnionMessageContents::Offers(msg) => Ok(msg.write(w)?),
                        OnionMessageContents::Custom(msg) => Ok(msg.write(w)?),
                }
        }
 }
 
-/// The contents of a custom onion message. Must implement `MaybeReadableArgs<u64>` where the `u64`
-/// is the custom TLV type attempting to be read, and return `Ok(None)` if the TLV type is unknown.
-pub trait CustomOnionMessageContents: Writeable + MaybeReadableArgs<u64> {
+/// The contents of a custom onion message.
+pub trait CustomOnionMessageContents: Writeable {
        /// Returns the TLV type identifying the message contents. MUST be >= 64.
        fn tlv_type(&self) -> u64;
 }
 
 /// Forward control TLVs in their blinded and unblinded form.
 pub(super) enum ForwardControlTlvs {
-       /// If we're sending to a blinded route, the node that constructed the blinded route has provided
+       /// If we're sending to a blinded path, the node that constructed the blinded path has provided
        /// this hop's control TLVs, already encrypted into bytes.
        Blinded(Vec<u8>),
        /// If we're constructing an onion message hop through an intermediate unblinded node, we'll need
        /// to construct the intermediate hop's control TLVs in their unblinded state to avoid encoding
-       /// them into an intermediate Vec. See [`super::blinded_route::ForwardTlvs`] for more info.
+       /// them into an intermediate Vec. See [`crate::blinded_path::message::ForwardTlvs`] for more
+       /// info.
        Unblinded(ForwardTlvs),
 }
 
@@ -154,7 +162,7 @@ pub(super) enum ForwardControlTlvs {
 pub(super) enum ReceiveControlTlvs {
        /// See [`ForwardControlTlvs::Blinded`].
        Blinded(Vec<u8>),
-       /// See [`ForwardControlTlvs::Unblinded`] and [`super::blinded_route::ReceiveTlvs`].
+       /// See [`ForwardControlTlvs::Unblinded`] and [`crate::blinded_path::message::ReceiveTlvs`].
        Unblinded(ReceiveTlvs),
 }
 
@@ -163,22 +171,22 @@ impl<T: CustomOnionMessageContents> Writeable for (Payload<T>, [u8; 32]) {
        fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
                match &self.0 {
                        Payload::Forward(ForwardControlTlvs::Blinded(encrypted_bytes)) => {
-                               encode_varint_length_prefixed_tlv!(w, {
-                                       (4, encrypted_bytes, vec_type)
+                               _encode_varint_length_prefixed_tlv!(w, {
+                                       (4, *encrypted_bytes, required_vec)
                                })
                        },
                        Payload::Receive {
                                control_tlvs: ReceiveControlTlvs::Blinded(encrypted_bytes), reply_path, message,
                        } => {
-                               encode_varint_length_prefixed_tlv!(w, {
+                               _encode_varint_length_prefixed_tlv!(w, {
                                        (2, reply_path, option),
-                                       (4, encrypted_bytes, vec_type),
+                                       (4, *encrypted_bytes, required_vec),
                                        (message.tlv_type(), message, required)
                                })
                        },
                        Payload::Forward(ForwardControlTlvs::Unblinded(control_tlvs)) => {
                                let write_adapter = ChaChaPolyWriteAdapter::new(self.1, &control_tlvs);
-                               encode_varint_length_prefixed_tlv!(w, {
+                               _encode_varint_length_prefixed_tlv!(w, {
                                        (4, write_adapter, required)
                                })
                        },
@@ -186,7 +194,7 @@ impl<T: CustomOnionMessageContents> Writeable for (Payload<T>, [u8; 32]) {
                                control_tlvs: ReceiveControlTlvs::Unblinded(control_tlvs), reply_path, message,
                        } => {
                                let write_adapter = ChaChaPolyWriteAdapter::new(self.1, &control_tlvs);
-                               encode_varint_length_prefixed_tlv!(w, {
+                               _encode_varint_length_prefixed_tlv!(w, {
                                        (2, reply_path, option),
                                        (4, write_adapter, required),
                                        (message.tlv_type(), message, required)
@@ -198,16 +206,19 @@ impl<T: CustomOnionMessageContents> Writeable for (Payload<T>, [u8; 32]) {
 }
 
 // Uses the provided secret to simultaneously decode and decrypt the control TLVs and data TLV.
-impl<T: CustomOnionMessageContents> ReadableArgs<SharedSecret> for Payload<T> {
-       fn read<R: Read>(r: &mut R, encrypted_tlvs_ss: SharedSecret) -> Result<Self, DecodeError> {
+impl<H: CustomOnionMessageHandler + ?Sized, L: Logger + ?Sized>
+ReadableArgs<(SharedSecret, &H, &L)> for Payload<<H as CustomOnionMessageHandler>::CustomMessage> {
+       fn read<R: Read>(r: &mut R, args: (SharedSecret, &H, &L)) -> Result<Self, DecodeError> {
+               let (encrypted_tlvs_ss, handler, logger) = args;
+
                let v: BigSize = Readable::read(r)?;
                let mut rd = FixedLengthReader::new(r, v.0);
-               let mut reply_path: Option<BlindedRoute> = None;
+               let mut reply_path: Option<BlindedPath> = None;
                let mut read_adapter: Option<ChaChaPolyReadAdapter<ControlTlvs>> = None;
                let rho = onion_utils::gen_rho_from_shared_secret(&encrypted_tlvs_ss.secret_bytes());
                let mut message_type: Option<u64> = None;
                let mut message = None;
-               decode_tlv_stream!(&mut rd, {
+               decode_tlv_stream_with_custom_tlv_decode!(&mut rd, {
                        (2, reply_path, option),
                        (4, read_adapter, (option: LengthReadableArgs, rho)),
                }, |msg_type, msg_reader| {
@@ -216,13 +227,19 @@ impl<T: CustomOnionMessageContents> ReadableArgs<SharedSecret> for Payload<T> {
                        if message_type.is_some() { return Err(DecodeError::InvalidValue) }
 
                        message_type = Some(msg_type);
-                       match T::read(msg_reader, msg_type) {
-                               Ok(Some(msg)) => {
-                                       message = Some(msg);
+                       match msg_type {
+                               tlv_type if OffersMessage::is_known_type(tlv_type) => {
+                                       let msg = OffersMessage::read(msg_reader, (tlv_type, logger))?;
+                                       message = Some(OnionMessageContents::Offers(msg));
                                        Ok(true)
                                },
-                               Ok(None) => Ok(false),
-                               Err(e) => Err(e),
+                               _ => match handler.read_custom_message(msg_type, msg_reader)? {
+                                       Some(msg) => {
+                                               message = Some(OnionMessageContents::Custom(msg));
+                                               Ok(true)
+                                       },
+                                       None => Ok(false),
+                               },
                        }
                });
                rd.eat_remaining().map_err(|_| DecodeError::ShortRead)?;
@@ -236,21 +253,21 @@ impl<T: CustomOnionMessageContents> ReadableArgs<SharedSecret> for Payload<T> {
                                Ok(Payload::Forward(ForwardControlTlvs::Unblinded(tlvs)))
                        },
                        Some(ChaChaPolyReadAdapter { readable: ControlTlvs::Receive(tlvs)}) => {
-                               if message.is_none() { return Err(DecodeError::InvalidValue) }
                                Ok(Payload::Receive {
                                        control_tlvs: ReceiveControlTlvs::Unblinded(tlvs),
                                        reply_path,
-                                       message: OnionMessageContents::Custom(message.unwrap()),
+                                       message: message.ok_or(DecodeError::InvalidValue)?,
                                })
-                       }
+                       },
                }
        }
 }
 
 /// When reading a packet off the wire, we don't know a priori whether the packet is to be forwarded
-/// or received. Thus we read a ControlTlvs rather than reading a ForwardControlTlvs or
-/// ReceiveControlTlvs directly.
-pub(super) enum ControlTlvs {
+/// or received. Thus we read a `ControlTlvs` rather than reading a [`ForwardTlvs`] or
+/// [`ReceiveTlvs`] directly. Also useful on the encoding side to keep forward and receive TLVs in
+/// the same iterator.
+pub(crate) enum ControlTlvs {
        /// This onion message is intended to be forwarded.
        Forward(ForwardTlvs),
        /// This onion message is intended to be received.
@@ -258,19 +275,16 @@ pub(super) enum ControlTlvs {
 }
 
 impl Readable for ControlTlvs {
-       fn read<R: Read>(mut r: &mut R) -> Result<Self, DecodeError> {
-               let mut _padding: Option<Padding> = None;
-               let mut _short_channel_id: Option<u64> = None;
-               let mut next_node_id: Option<PublicKey> = None;
-               let mut path_id: Option<[u8; 32]> = None;
-               let mut next_blinding_override: Option<PublicKey> = None;
-               decode_tlv_stream!(&mut r, {
+       fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
+               _init_and_read_tlv_stream!(r, {
                        (1, _padding, option),
                        (2, _short_channel_id, option),
                        (4, next_node_id, option),
                        (6, path_id, option),
                        (8, next_blinding_override, option),
                });
+               let _padding: Option<Padding> = _padding;
+               let _short_channel_id: Option<u64> = _short_channel_id;
 
                let valid_fwd_fmt  = next_node_id.is_some() && path_id.is_none();
                let valid_recv_fmt = next_node_id.is_none() && next_blinding_override.is_none();
@@ -292,15 +306,11 @@ impl Readable for ControlTlvs {
        }
 }
 
-/// Reads padding to the end, ignoring what's read.
-pub(crate) struct Padding {}
-impl Readable for Padding {
-       #[inline]
-       fn read<R: Read>(reader: &mut R) -> Result<Self, DecodeError> {
-               loop {
-                       let mut buf = [0; 8192];
-                       if reader.read(&mut buf[..])? == 0 { break; }
+impl Writeable for ControlTlvs {
+       fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
+               match self {
+                       Self::Forward(tlvs) => tlvs.write(w),
+                       Self::Receive(tlvs) => tlvs.write(w),
                }
-               Ok(Self {})
        }
 }