From 3a33693b1e279221f517b33af6bbdf38cc1330a9 Mon Sep 17 00:00:00 2001 From: Omer Yacine Date: Fri, 6 Jan 2023 10:18:26 +0200 Subject: [PATCH] Expose `impl_writeable_tlv_based` macro Every exported macro needed to have all the macros used inside it: 1- to be exported as well. 2- be called from the `$crate` namespace so it works in other crates. Some structs in `lightning::util::ser` needed to be made public as they were used inside the exported macros. Use the macros like this: ```Rust lightning::impl_writeable_tlv_based!(...) ``` --- lightning/src/ln/channelmanager.rs | 2 +- lightning/src/ln/msgs.rs | 10 +- lightning/src/onion_message/packet.rs | 10 +- lightning/src/routing/gossip.rs | 58 ++-- lightning/src/util/chacha20poly1305rfc.rs | 2 +- lightning/src/util/mod.rs | 2 +- lightning/src/util/ser.rs | 20 +- lightning/src/util/ser_macros.rs | 342 +++++++++++++++++----- 8 files changed, 317 insertions(+), 129 deletions(-) diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs index 03a150e4f..ca95b5edf 100644 --- a/lightning/src/ln/channelmanager.rs +++ b/lightning/src/ln/channelmanager.rs @@ -6049,7 +6049,7 @@ impl Writeable for ChannelDetails { impl Readable for ChannelDetails { fn read(reader: &mut R) -> Result { - init_and_read_tlv_fields!(reader, { + _init_and_read_tlv_fields!(reader, { (1, inbound_scid_alias, option), (2, channel_id, required), (3, channel_type, option), diff --git a/lightning/src/ln/msgs.rs b/lightning/src/ln/msgs.rs index 1478f8b6b..399feaf67 100644 --- a/lightning/src/ln/msgs.rs +++ b/lightning/src/ln/msgs.rs @@ -821,8 +821,8 @@ pub struct CommitmentUpdate { } /// Messages could have optional fields to use with extended features -/// As we wish to serialize these differently from Options (Options get a tag byte, but -/// OptionalFeild simply gets Present if there are enough bytes to read into it), we have a +/// As we wish to serialize these differently from `Option`s (`Options` get a tag byte, but +/// [`OptionalField`] simply gets `Present` if there are enough bytes to read into it), we have a /// separate enum type for them. /// (C-not exported) due to a free generic in T #[derive(Clone, Debug, PartialEq, Eq)] @@ -1455,14 +1455,14 @@ impl Writeable for OnionHopData { fn write(&self, w: &mut W) -> Result<(), io::Error> { match self.format { OnionHopDataFormat::NonFinalNode { short_channel_id } => { - encode_varint_length_prefixed_tlv!(w, { + _encode_varint_length_prefixed_tlv!(w, { (2, HighZeroBytesDroppedBigSize(self.amt_to_forward), required), (4, HighZeroBytesDroppedBigSize(self.outgoing_cltv_value), required), (6, short_channel_id, required) }); }, OnionHopDataFormat::FinalNode { ref payment_data, ref keysend_preimage } => { - encode_varint_length_prefixed_tlv!(w, { + _encode_varint_length_prefixed_tlv!(w, { (2, HighZeroBytesDroppedBigSize(self.amt_to_forward), required), (4, HighZeroBytesDroppedBigSize(self.outgoing_cltv_value), required), (8, payment_data, option), @@ -2875,7 +2875,7 @@ mod tests { let mut encoded_payload = Vec::new(); let test_bytes = vec![42u8; 1000]; if let OnionHopDataFormat::NonFinalNode { short_channel_id } = payload.format { - encode_varint_length_prefixed_tlv!(&mut encoded_payload, { + _encode_varint_length_prefixed_tlv!(&mut encoded_payload, { (1, test_bytes, vec_type), (2, HighZeroBytesDroppedBigSize(payload.amt_to_forward), required), (4, HighZeroBytesDroppedBigSize(payload.outgoing_cltv_value), required), diff --git a/lightning/src/onion_message/packet.rs b/lightning/src/onion_message/packet.rs index 5ff226387..27c329335 100644 --- a/lightning/src/onion_message/packet.rs +++ b/lightning/src/onion_message/packet.rs @@ -166,14 +166,14 @@ impl Writeable for (Payload, [u8; 32]) { fn write(&self, w: &mut W) -> Result<(), io::Error> { match &self.0 { Payload::Forward(ForwardControlTlvs::Blinded(encrypted_bytes)) => { - encode_varint_length_prefixed_tlv!(w, { + _encode_varint_length_prefixed_tlv!(w, { (4, *encrypted_bytes, vec_type) }) }, 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), (message.tlv_type(), message, required) @@ -181,7 +181,7 @@ impl Writeable for (Payload, [u8; 32]) { }, 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) }) }, @@ -189,7 +189,7 @@ impl Writeable for (Payload, [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) @@ -212,7 +212,7 @@ impl ReadableArgs<(SharedSecret, &H)> for Payload< let rho = onion_utils::gen_rho_from_shared_secret(&encrypted_tlvs_ss.secret_bytes()); let mut message_type: Option = 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| { diff --git a/lightning/src/routing/gossip.rs b/lightning/src/routing/gossip.rs index 947df9eda..d0682d47d 100644 --- a/lightning/src/routing/gossip.rs +++ b/lightning/src/routing/gossip.rs @@ -673,13 +673,13 @@ impl Writeable for ChannelUpdateInfo { impl Readable for ChannelUpdateInfo { fn read(reader: &mut R) -> Result { - init_tlv_field_var!(last_update, required); - init_tlv_field_var!(enabled, required); - init_tlv_field_var!(cltv_expiry_delta, required); - init_tlv_field_var!(htlc_minimum_msat, required); - init_tlv_field_var!(htlc_maximum_msat, option); - init_tlv_field_var!(fees, required); - init_tlv_field_var!(last_update_message, required); + _init_tlv_field_var!(last_update, required); + _init_tlv_field_var!(enabled, required); + _init_tlv_field_var!(cltv_expiry_delta, required); + _init_tlv_field_var!(htlc_minimum_msat, required); + _init_tlv_field_var!(htlc_maximum_msat, option); + _init_tlv_field_var!(fees, required); + _init_tlv_field_var!(last_update_message, required); read_tlv_fields!(reader, { (0, last_update, required), @@ -693,13 +693,13 @@ impl Readable for ChannelUpdateInfo { if let Some(htlc_maximum_msat) = htlc_maximum_msat { Ok(ChannelUpdateInfo { - last_update: init_tlv_based_struct_field!(last_update, required), - enabled: init_tlv_based_struct_field!(enabled, required), - cltv_expiry_delta: init_tlv_based_struct_field!(cltv_expiry_delta, required), - htlc_minimum_msat: init_tlv_based_struct_field!(htlc_minimum_msat, required), + last_update: _init_tlv_based_struct_field!(last_update, required), + enabled: _init_tlv_based_struct_field!(enabled, required), + cltv_expiry_delta: _init_tlv_based_struct_field!(cltv_expiry_delta, required), + htlc_minimum_msat: _init_tlv_based_struct_field!(htlc_minimum_msat, required), htlc_maximum_msat, - fees: init_tlv_based_struct_field!(fees, required), - last_update_message: init_tlv_based_struct_field!(last_update_message, required), + fees: _init_tlv_based_struct_field!(fees, required), + last_update_message: _init_tlv_based_struct_field!(last_update_message, required), }) } else { Err(DecodeError::InvalidValue) @@ -820,14 +820,14 @@ impl MaybeReadable for ChannelUpdateInfoDeserWrapper { impl Readable for ChannelInfo { fn read(reader: &mut R) -> Result { - init_tlv_field_var!(features, required); - init_tlv_field_var!(announcement_received_time, (default_value, 0)); - init_tlv_field_var!(node_one, required); + _init_tlv_field_var!(features, required); + _init_tlv_field_var!(announcement_received_time, (default_value, 0)); + _init_tlv_field_var!(node_one, required); let mut one_to_two_wrap: Option = None; - init_tlv_field_var!(node_two, required); + _init_tlv_field_var!(node_two, required); let mut two_to_one_wrap: Option = None; - init_tlv_field_var!(capacity_sats, required); - init_tlv_field_var!(announcement_message, required); + _init_tlv_field_var!(capacity_sats, required); + _init_tlv_field_var!(announcement_message, required); read_tlv_fields!(reader, { (0, features, required), (1, announcement_received_time, (default_value, 0)), @@ -840,14 +840,14 @@ impl Readable for ChannelInfo { }); Ok(ChannelInfo { - features: init_tlv_based_struct_field!(features, required), - node_one: init_tlv_based_struct_field!(node_one, required), + features: _init_tlv_based_struct_field!(features, required), + node_one: _init_tlv_based_struct_field!(node_one, required), one_to_two: one_to_two_wrap.map(|w| w.0).unwrap_or(None), - node_two: init_tlv_based_struct_field!(node_two, required), + node_two: _init_tlv_based_struct_field!(node_two, required), two_to_one: two_to_one_wrap.map(|w| w.0).unwrap_or(None), - capacity_sats: init_tlv_based_struct_field!(capacity_sats, required), - announcement_message: init_tlv_based_struct_field!(announcement_message, required), - announcement_received_time: init_tlv_based_struct_field!(announcement_received_time, (default_value, 0)), + capacity_sats: _init_tlv_based_struct_field!(capacity_sats, required), + announcement_message: _init_tlv_based_struct_field!(announcement_message, required), + announcement_received_time: _init_tlv_based_struct_field!(announcement_received_time, (default_value, 0)), }) } } @@ -1103,9 +1103,9 @@ impl MaybeReadable for NodeAnnouncementInfoDeserWrapper { impl Readable for NodeInfo { fn read(reader: &mut R) -> Result { - init_tlv_field_var!(lowest_inbound_channel_fees, option); + _init_tlv_field_var!(lowest_inbound_channel_fees, option); let mut announcement_info_wrap: Option = None; - init_tlv_field_var!(channels, vec_type); + _init_tlv_field_var!(channels, vec_type); read_tlv_fields!(reader, { (0, lowest_inbound_channel_fees, option), @@ -1114,9 +1114,9 @@ impl Readable for NodeInfo { }); Ok(NodeInfo { - lowest_inbound_channel_fees: init_tlv_based_struct_field!(lowest_inbound_channel_fees, option), + lowest_inbound_channel_fees: _init_tlv_based_struct_field!(lowest_inbound_channel_fees, option), announcement_info: announcement_info_wrap.map(|w| w.0), - channels: init_tlv_based_struct_field!(channels, vec_type), + channels: _init_tlv_based_struct_field!(channels, vec_type), }) } } diff --git a/lightning/src/util/chacha20poly1305rfc.rs b/lightning/src/util/chacha20poly1305rfc.rs index 552226ca3..052968377 100644 --- a/lightning/src/util/chacha20poly1305rfc.rs +++ b/lightning/src/util/chacha20poly1305rfc.rs @@ -411,7 +411,7 @@ mod tests { #[test] fn chacha_stream_adapters_ser_macros() { // Test that our stream adapters work as expected with the TLV macros. - // This also serves to test the `option: $trait` variant of the `decode_tlv` ser macro. + // This also serves to test the `option: $trait` variant of the `_decode_tlv` ser macro. do_chacha_stream_adapters_ser_macros().unwrap() } } diff --git a/lightning/src/util/mod.rs b/lightning/src/util/mod.rs index 730131f22..1d46865b6 100644 --- a/lightning/src/util/mod.rs +++ b/lightning/src/util/mod.rs @@ -13,7 +13,7 @@ pub(crate) mod fuzz_wrappers; #[macro_use] -pub(crate) mod ser_macros; +pub mod ser_macros; pub mod events; pub mod errors; diff --git a/lightning/src/util/ser.rs b/lightning/src/util/ser.rs index 02d4a81b3..0f88ccbd5 100644 --- a/lightning/src/util/ser.rs +++ b/lightning/src/util/ser.rs @@ -84,7 +84,7 @@ impl Writer for VecWriter { /// Writer that only tracks the amount of data written - useful if you need to calculate the length /// of some data when serialized but don't yet need the full data. -pub(crate) struct LengthCalculatingWriter(pub usize); +pub struct LengthCalculatingWriter(pub usize); impl Writer for LengthCalculatingWriter { #[inline] fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> { @@ -93,23 +93,26 @@ impl Writer for LengthCalculatingWriter { } } -/// Essentially std::io::Take but a bit simpler and with a method to walk the underlying stream +/// Essentially [`std::io::Take`] but a bit simpler and with a method to walk the underlying stream /// forward to ensure we always consume exactly the fixed length specified. -pub(crate) struct FixedLengthReader { +pub struct FixedLengthReader { read: R, bytes_read: u64, total_bytes: u64, } impl FixedLengthReader { + /// Returns a new [`FixedLengthReader`]. pub fn new(read: R, total_bytes: u64) -> Self { Self { read, bytes_read: 0, total_bytes } } + /// Returns whether some bytes are remaining or not. #[inline] pub fn bytes_remain(&mut self) -> bool { self.bytes_read != self.total_bytes } + /// Consumes the remaining bytes. #[inline] pub fn eat_remaining(&mut self) -> Result<(), DecodeError> { copy(self, &mut sink()).unwrap(); @@ -145,13 +148,15 @@ impl LengthRead for FixedLengthReader { } } -/// A Read which tracks whether any bytes have been read at all. This allows us to distinguish +/// A [`Read`] implementation which tracks whether any bytes have been read at all. This allows us to distinguish /// between "EOF reached before we started" and "EOF reached mid-read". -pub(crate) struct ReadTrackingReader { +pub struct ReadTrackingReader { read: R, + /// Returns whether we have read from this reader or not yet. pub have_read: bool, } impl ReadTrackingReader { + /// Returns a new [`ReadTrackingReader`]. pub fn new(read: R) -> Self { Self { read, have_read: false } } @@ -278,7 +283,8 @@ impl MaybeReadable for T { } } -pub(crate) struct OptionDeserWrapper(pub Option); +/// Wrapper to read a required (non-optional) TLV record. +pub struct OptionDeserWrapper(pub Option); impl Readable for OptionDeserWrapper { #[inline] fn read(reader: &mut R) -> Result { @@ -528,7 +534,7 @@ impl Readable for [u16; 8] { /// For variable-length values within TLV record where the length is encoded as part of the record. /// Used to prevent encoding the length twice. -pub(crate) struct WithoutLength(pub T); +pub struct WithoutLength(pub T); impl Writeable for WithoutLength<&String> { #[inline] diff --git a/lightning/src/util/ser_macros.rs b/lightning/src/util/ser_macros.rs index d37a841ea..2ed3683f4 100644 --- a/lightning/src/util/ser_macros.rs +++ b/lightning/src/util/ser_macros.rs @@ -7,9 +7,19 @@ // You may not use this file except in accordance with one or both of these // licenses. -macro_rules! encode_tlv { +//! Some macros that implement [`Readable`]/[`Writeable`] traits for lightning messages. +//! They also handle serialization and deserialization of TLVs. +//! +//! [`Readable`]: crate::util::ser::Readable +//! [`Writeable`]: crate::util::ser::Writeable + +/// Implements serialization for a single TLV record. +/// This is exported for use by other exported macros, do not use directly. +#[doc(hidden)] +#[macro_export] +macro_rules! _encode_tlv { ($stream: expr, $type: expr, $field: expr, (default_value, $default: expr)) => { - encode_tlv!($stream, $type, $field, required) + $crate::_encode_tlv!($stream, $type, $field, required) }; ($stream: expr, $type: expr, $field: expr, (static_value, $value: expr)) => { let _ = &$field; // Ensure we "use" the $field @@ -20,7 +30,7 @@ macro_rules! encode_tlv { $field.write($stream)?; }; ($stream: expr, $type: expr, $field: expr, vec_type) => { - encode_tlv!($stream, $type, $crate::util::ser::WithoutLength(&$field), required); + $crate::_encode_tlv!($stream, $type, $crate::util::ser::WithoutLength(&$field), required); }; ($stream: expr, $optional_type: expr, $optional_field: expr, option) => { if let Some(ref field) = $optional_field { @@ -30,15 +40,18 @@ macro_rules! encode_tlv { } }; ($stream: expr, $type: expr, $field: expr, (option, encoding: ($fieldty: ty, $encoding: ident))) => { - encode_tlv!($stream, $type, $field.map(|f| $encoding(f)), option); + $crate::_encode_tlv!($stream, $type, $field.map(|f| $encoding(f)), option); }; ($stream: expr, $type: expr, $field: expr, (option, encoding: $fieldty: ty)) => { - encode_tlv!($stream, $type, $field, option); + $crate::_encode_tlv!($stream, $type, $field, option); }; } - -macro_rules! check_encoded_tlv_order { +/// Panics if the last seen TLV type is not numerically less than the TLV type currently being checked. +/// This is exported for use by other exported macros, do not use directly. +#[doc(hidden)] +#[macro_export] +macro_rules! _check_encoded_tlv_order { ($last_type: expr, $type: expr, (static_value, $value: expr)) => { }; ($last_type: expr, $type: expr, $fieldty: tt) => { if let Some(t) = $last_type { @@ -48,6 +61,45 @@ macro_rules! check_encoded_tlv_order { }; } +/// Implements the TLVs serialization part in a [`Writeable`] implementation of a struct. +/// +/// This should be called inside a method which returns `Result<_, `[`io::Error`]`>`, such as +/// [`Writeable::write`]. It will only return an `Err` if the stream `Err`s or [`Writeable::write`] +/// on one of the fields `Err`s. +/// +/// `$stream` must be a `&mut `[`Writer`] which will receive the bytes for each TLV in the stream. +/// +/// Fields MUST be sorted in `$type`-order. +/// +/// Note that the lightning TLV requirements require that a single type not appear more than once, +/// that TLVs are sorted in type-ascending order, and that any even types be understood by the +/// decoder. +/// +/// Any `option` fields which have a value of `None` will not be serialized at all. +/// +/// For example, +/// ``` +/// # use lightning::encode_tlv_stream; +/// # fn write (stream: &mut W) -> Result<(), lightning::io::Error> { +/// let mut required_value = 0u64; +/// let mut optional_value: Option = None; +/// encode_tlv_stream!(stream, { +/// (0, required_value, required), +/// (1, Some(42u64), option), +/// (2, optional_value, option), +/// }); +/// // At this point `required_value` has been written as a TLV of type 0, `42u64` has been written +/// // as a TLV of type 1 (indicating the reader may ignore it if it is not understood), and *no* +/// // TLV is written with type 2. +/// # Ok(()) +/// # } +/// ``` +/// +/// [`Writeable`]: crate::util::ser::Writeable +/// [`io::Error`]: crate::io::Error +/// [`Writeable::write`]: crate::util::ser::Writeable::write +/// [`Writer`]: crate::util::ser::Writer +#[macro_export] macro_rules! encode_tlv_stream { ($stream: expr, {$(($type: expr, $field: expr, $fieldty: tt)),* $(,)*}) => { { #[allow(unused_imports)] @@ -55,10 +107,11 @@ macro_rules! encode_tlv_stream { ln::msgs::DecodeError, util::ser, util::ser::BigSize, + util::ser::Writeable, }; $( - encode_tlv!($stream, $type, $field, $fieldty); + $crate::_encode_tlv!($stream, $type, $field, $fieldty); )* #[allow(unused_mut, unused_variables, unused_assignments)] @@ -66,15 +119,21 @@ macro_rules! encode_tlv_stream { { let mut last_seen: Option = None; $( - check_encoded_tlv_order!(last_seen, $type, $fieldty); + $crate::_check_encoded_tlv_order!(last_seen, $type, $fieldty); )* } } } } -macro_rules! get_varint_length_prefixed_tlv_length { +/// Adds the length of the serialized field to a [`LengthCalculatingWriter`]. +/// This is exported for use by other exported macros, do not use directly. +/// +/// [`LengthCalculatingWriter`]: crate::util::ser::LengthCalculatingWriter +#[doc(hidden)] +#[macro_export] +macro_rules! _get_varint_length_prefixed_tlv_length { ($len: expr, $type: expr, $field: expr, (default_value, $default: expr)) => { - get_varint_length_prefixed_tlv_length!($len, $type, $field, required) + $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $field, required) }; ($len: expr, $type: expr, $field: expr, (static_value, $value: expr)) => { }; @@ -85,7 +144,7 @@ macro_rules! get_varint_length_prefixed_tlv_length { $len.0 += field_len; }; ($len: expr, $type: expr, $field: expr, vec_type) => { - get_varint_length_prefixed_tlv_length!($len, $type, $crate::util::ser::WithoutLength(&$field), required); + $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $crate::util::ser::WithoutLength(&$field), required); }; ($len: expr, $optional_type: expr, $optional_field: expr, option) => { if let Some(ref field) = $optional_field { @@ -97,25 +156,33 @@ macro_rules! get_varint_length_prefixed_tlv_length { }; } -macro_rules! encode_varint_length_prefixed_tlv { +/// See the documentation of [`write_tlv_fields`]. +/// This is exported for use by other exported macros, do not use directly. +#[doc(hidden)] +#[macro_export] +macro_rules! _encode_varint_length_prefixed_tlv { ($stream: expr, {$(($type: expr, $field: expr, $fieldty: tt)),*}) => { { use $crate::util::ser::BigSize; let len = { #[allow(unused_mut)] let mut len = $crate::util::ser::LengthCalculatingWriter(0); $( - get_varint_length_prefixed_tlv_length!(len, $type, $field, $fieldty); + $crate::_get_varint_length_prefixed_tlv_length!(len, $type, $field, $fieldty); )* len.0 }; BigSize(len as u64).write($stream)?; - encode_tlv_stream!($stream, { $(($type, $field, $fieldty)),* }); + $crate::encode_tlv_stream!($stream, { $(($type, $field, $fieldty)),* }); } } } -macro_rules! check_decoded_tlv_order { +/// Errors if there are missing required TLV types between the last seen type and the type currently being processed. +/// This is exported for use by other exported macros, do not use directly. +#[doc(hidden)] +#[macro_export] +macro_rules! _check_decoded_tlv_order { ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (default_value, $default: expr)) => {{ - #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always true + #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always false let invalid_order = ($last_seen_type.is_none() || $last_seen_type.unwrap() < $type) && $typ.0 > $type; if invalid_order { $field = $default.into(); @@ -124,7 +191,7 @@ macro_rules! check_decoded_tlv_order { ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (static_value, $value: expr)) => { }; ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, required) => {{ - #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always true + #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always false let invalid_order = ($last_seen_type.is_none() || $last_seen_type.unwrap() < $type) && $typ.0 > $type; if invalid_order { return Err(DecodeError::InvalidValue); @@ -147,9 +214,13 @@ macro_rules! check_decoded_tlv_order { }}; } -macro_rules! check_missing_tlv { +/// Errors if there are missing required TLV types after the last seen type. +/// This is exported for use by other exported macros, do not use directly. +#[doc(hidden)] +#[macro_export] +macro_rules! _check_missing_tlv { ($last_seen_type: expr, $type: expr, $field: ident, (default_value, $default: expr)) => {{ - #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always true + #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always false let missing_req_type = $last_seen_type.is_none() || $last_seen_type.unwrap() < $type; if missing_req_type { $field = $default.into(); @@ -159,7 +230,7 @@ macro_rules! check_missing_tlv { $field = $value; }; ($last_seen_type: expr, $type: expr, $field: ident, required) => {{ - #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always true + #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always false let missing_req_type = $last_seen_type.is_none() || $last_seen_type.unwrap() < $type; if missing_req_type { return Err(DecodeError::InvalidValue); @@ -182,9 +253,13 @@ macro_rules! check_missing_tlv { }}; } -macro_rules! decode_tlv { +/// Implements deserialization for a single TLV record. +/// This is exported for use by other exported macros, do not use directly. +#[doc(hidden)] +#[macro_export] +macro_rules! _decode_tlv { ($reader: expr, $field: ident, (default_value, $default: expr)) => {{ - decode_tlv!($reader, $field, required) + $crate::_decode_tlv!($reader, $field, required) }}; ($reader: expr, $field: ident, (static_value, $value: expr)) => {{ }}; @@ -211,33 +286,89 @@ macro_rules! decode_tlv { }; }}; ($reader: expr, $field: ident, (option, encoding: $fieldty: ty)) => {{ - decode_tlv!($reader, $field, option); + $crate::_decode_tlv!($reader, $field, option); }}; } +/// Checks if `$val` matches `$type`. +/// This is exported for use by other exported macros, do not use directly. +#[doc(hidden)] +#[macro_export] macro_rules! _decode_tlv_stream_match_check { ($val: ident, $type: expr, (static_value, $value: expr)) => { false }; ($val: ident, $type: expr, $fieldty: tt) => { $val == $type } } -// `$decode_custom_tlv` is a closure that may be optionally provided to handle custom message types. -// If it is provided, it will be called with the custom type and the `FixedLengthReader` containing -// the message contents. It should return `Ok(true)` if the custom message is successfully parsed, -// `Ok(false)` if the message type is unknown, and `Err(DecodeError)` if parsing fails. +/// Implements the TLVs deserialization part in a [`Readable`] implementation of a struct. +/// +/// This should be called inside a method which returns `Result<_, `[`DecodeError`]`>`, such as +/// [`Readable::read`]. It will either return an `Err` or ensure all `required` fields have been +/// read and optionally read `optional` fields. +/// +/// `$stream` must be a [`Read`] and will be fully consumed, reading until no more bytes remain +/// (i.e. it returns [`DecodeError::ShortRead`]). +/// +/// Fields MUST be sorted in `$type`-order. +/// +/// Note that the lightning TLV requirements require that a single type not appear more than once, +/// that TLVs are sorted in type-ascending order, and that any even types be understood by the +/// decoder. +/// +/// For example, +/// ``` +/// # use lightning::decode_tlv_stream; +/// # fn read (stream: R) -> Result<(), lightning::ln::msgs::DecodeError> { +/// let mut required_value = 0u64; +/// let mut optional_value: Option = None; +/// decode_tlv_stream!(stream, { +/// (0, required_value, required), +/// (2, optional_value, option), +/// }); +/// // At this point, `required_value` has been overwritten with the TLV with type 0. +/// // `optional_value` may have been overwritten, setting it to `Some` if a TLV with type 2 was +/// // present. +/// # Ok(()) +/// # } +/// ``` +/// +/// [`Readable`]: crate::util::ser::Readable +/// [`DecodeError`]: crate::ln::msgs::DecodeError +/// [`Readable::read`]: crate::util::ser::Readable::read +/// [`Read`]: crate::io::Read +/// [`DecodeError::ShortRead`]: crate::ln::msgs::DecodeError::ShortRead +#[macro_export] macro_rules! decode_tlv_stream { + ($stream: expr, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => { + let rewind = |_, _| { unreachable!() }; + $crate::_decode_tlv_stream_range!($stream, .., rewind, {$(($type, $field, $fieldty)),*}); + } +} + +/// Similar to [`decode_tlv_stream`] with a custom TLV decoding capabilities. +/// +/// `$decode_custom_tlv` is a closure that may be optionally provided to handle custom message types. +/// If it is provided, it will be called with the custom type and the [`FixedLengthReader`] containing +/// the message contents. It should return `Ok(true)` if the custom message is successfully parsed, +/// `Ok(false)` if the message type is unknown, and `Err(`[`DecodeError`]`)` if parsing fails. +/// +/// [`FixedLengthReader`]: crate::util::ser::FixedLengthReader +/// [`DecodeError`]: crate::ln::msgs::DecodeError +macro_rules! decode_tlv_stream_with_custom_tlv_decode { ($stream: expr, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*} $(, $decode_custom_tlv: expr)?) => { { let rewind = |_, _| { unreachable!() }; - use core::ops::RangeBounds; - decode_tlv_stream_range!( + _decode_tlv_stream_range!( $stream, .., rewind, {$(($type, $field, $fieldty)),*} $(, $decode_custom_tlv)? ); } } } -macro_rules! decode_tlv_stream_range { +#[doc(hidden)] +#[macro_export] +macro_rules! _decode_tlv_stream_range { ($stream: expr, $range: expr, $rewind: ident, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*} $(, $decode_custom_tlv: expr)?) => { { + use core::ops::RangeBounds; use $crate::ln::msgs::DecodeError; let mut last_seen_type: Option = None; let mut stream_ref = $stream; @@ -249,7 +380,7 @@ macro_rules! decode_tlv_stream_range { // We track whether any bytes were read during the consensus_decode call to // determine whether we should break or return ShortRead if we get an // UnexpectedEof. This should in every case be largely cosmetic, but its nice to - // pass the TLV test vectors exactly, which requre this distinction. + // pass the TLV test vectors exactly, which require this distinction. let mut tracking_reader = ser::ReadTrackingReader::new(&mut stream_ref); match <$crate::util::ser::BigSize as $crate::util::ser::Readable>::read(&mut tracking_reader) { Err(DecodeError::ShortRead) => { @@ -279,9 +410,9 @@ macro_rules! decode_tlv_stream_range { }, _ => {}, } - // As we read types, make sure we hit every required type: + // As we read types, make sure we hit every required type between `last_seen_type` and `typ`: $({ - check_decoded_tlv_order!(last_seen_type, typ, $type, $field, $fieldty); + $crate::_check_decoded_tlv_order!(last_seen_type, typ, $type, $field, $fieldty); })* last_seen_type = Some(typ.0); @@ -289,8 +420,8 @@ macro_rules! decode_tlv_stream_range { let length: ser::BigSize = $crate::util::ser::Readable::read(&mut stream_ref)?; let mut s = ser::FixedLengthReader::new(&mut stream_ref, length.0); match typ.0 { - $(_t if _decode_tlv_stream_match_check!(_t, $type, $fieldty) => { - decode_tlv!(s, $field, $fieldty); + $(_t if $crate::_decode_tlv_stream_match_check!(_t, $type, $fieldty) => { + $crate::_decode_tlv!(s, $field, $fieldty); if s.bytes_remain() { s.eat_remaining()?; // Return ShortRead if there's actually not enough bytes return Err(DecodeError::InvalidValue); @@ -314,7 +445,7 @@ macro_rules! decode_tlv_stream_range { } // Make sure we got to each required type after we've read every TLV: $({ - check_missing_tlv!(last_seen_type, $type, $field, $fieldty); + $crate::_check_missing_tlv!(last_seen_type, $type, $field, $fieldty); })* } } } @@ -331,7 +462,7 @@ macro_rules! impl_writeable_msg { impl $crate::util::ser::Readable for $st { fn read(r: &mut R) -> Result { $(let $field = $crate::util::ser::Readable::read(r)?;)* - $(init_tlv_field_var!($tlvfield, $fieldty);)* + $(_init_tlv_field_var!($tlvfield, $fieldty);)* decode_tlv_stream!(r, {$(($type, $tlvfield, $fieldty)),*}); Ok(Self { $($field),*, @@ -375,12 +506,14 @@ macro_rules! impl_writeable { /// object. /// $min_version_that_can_read_this is the minimum reader version which can understand this /// serialized object. Previous versions will simply err with a -/// DecodeError::UnknownVersion. +/// [`DecodeError::UnknownVersion`]. /// -/// Updates to either $this_version or $min_version_that_can_read_this should be included in +/// Updates to either `$this_version` or `$min_version_that_can_read_this` should be included in /// release notes. /// /// Both version fields can be specific to this type of object. +/// +/// [`DecodeError::UnknownVersion`]: crate::ln::msgs::DecodeError::UnknownVersion macro_rules! write_ver_prefix { ($stream: expr, $this_version: expr, $min_version_that_can_read_this: expr) => { $stream.write_all(&[$this_version; 1])?; @@ -388,23 +521,26 @@ macro_rules! write_ver_prefix { } } -/// Writes out a suffix to an object which contains potentially backwards-compatible, optional -/// fields which old nodes can happily ignore. +/// Writes out a suffix to an object as a length-prefixed TLV stream which contains potentially +/// backwards-compatible, optional fields which old nodes can happily ignore. /// /// It is written out in TLV format and, as with all TLV fields, unknown even fields cause a -/// DecodeError::UnknownRequiredFeature error, with unknown odd fields ignored. +/// [`DecodeError::UnknownRequiredFeature`] error, with unknown odd fields ignored. /// /// This is the preferred method of adding new fields that old nodes can ignore and still function /// correctly. +/// +/// [`DecodeError::UnknownRequiredFeature`]: crate::ln::msgs::DecodeError::UnknownRequiredFeature +#[macro_export] macro_rules! write_tlv_fields { ($stream: expr, {$(($type: expr, $field: expr, $fieldty: tt)),* $(,)*}) => { - encode_varint_length_prefixed_tlv!($stream, {$(($type, $field, $fieldty)),*}) + $crate::_encode_varint_length_prefixed_tlv!($stream, {$(($type, $field, $fieldty)),*}) } } -/// Reads a prefix added by write_ver_prefix!(), above. Takes the current version of the +/// Reads a prefix added by [`write_ver_prefix`], above. Takes the current version of the /// serialization logic for this object. This is compared against the -/// $min_version_that_can_read_this added by write_ver_prefix!(). +/// `$min_version_that_can_read_this` added by [`write_ver_prefix`]. macro_rules! read_ver_prefix { ($stream: expr, $this_version: expr) => { { let ver: u8 = Readable::read($stream)?; @@ -416,17 +552,24 @@ macro_rules! read_ver_prefix { } } } -/// Reads a suffix added by write_tlv_fields. +/// Reads a suffix added by [`write_tlv_fields`]. +/// +/// [`write_tlv_fields`]: crate::write_tlv_fields +#[macro_export] macro_rules! read_tlv_fields { ($stream: expr, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => { { let tlv_len: $crate::util::ser::BigSize = $crate::util::ser::Readable::read($stream)?; let mut rd = $crate::util::ser::FixedLengthReader::new($stream, tlv_len.0); - decode_tlv_stream!(&mut rd, {$(($type, $field, $fieldty)),*}); + $crate::decode_tlv_stream!(&mut rd, {$(($type, $field, $fieldty)),*}); rd.eat_remaining().map_err(|_| $crate::ln::msgs::DecodeError::ShortRead)?; } } } -macro_rules! init_tlv_based_struct_field { +/// Initializes the struct fields. +/// This is exported for use by other exported macros, do not use directly. +#[doc(hidden)] +#[macro_export] +macro_rules! _init_tlv_based_struct_field { ($field: ident, (default_value, $default: expr)) => { $field.0.unwrap() }; @@ -444,7 +587,11 @@ macro_rules! init_tlv_based_struct_field { }; } -macro_rules! init_tlv_field_var { +/// Initializes the variable we are going to read the TLV into. +/// This is exported for use by other exported macros, do not use directly. +#[doc(hidden)] +#[macro_export] +macro_rules! _init_tlv_field_var { ($field: ident, (default_value, $default: expr)) => { let mut $field = $crate::util::ser::OptionDeserWrapper(None); }; @@ -462,28 +609,54 @@ macro_rules! init_tlv_field_var { }; } -macro_rules! init_and_read_tlv_fields { +/// Equivalent to running [`_init_tlv_field_var`] then [`read_tlv_fields`]. +/// This is exported for use by other exported macros, do not use directly. +#[doc(hidden)] +#[macro_export] +macro_rules! _init_and_read_tlv_fields { ($reader: ident, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => { $( - init_tlv_field_var!($field, $fieldty); + $crate::_init_tlv_field_var!($field, $fieldty); )* - read_tlv_fields!($reader, { + $crate::read_tlv_fields!($reader, { $(($type, $field, $fieldty)),* }); } } -/// Implements Readable/Writeable for a struct storing it as a set of TLVs -/// If $fieldty is `required`, then $field is a required field that is not an Option nor a Vec. -/// If $fieldty is `option`, then $field is optional field. -/// if $fieldty is `vec_type`, then $field is a Vec, which needs to have its individual elements -/// serialized. +/// Implements [`Readable`]/[`Writeable`] for a struct storing it as a set of TLVs +/// If `$fieldty` is `required`, then `$field` is a required field that is not an Option nor a Vec. +/// If `$fieldty` is `(default_value, $default)`, then `$field` will be set to `$default` if not present. +/// If `$fieldty` is `option`, then `$field` is optional field. +/// If `$fieldty` is `vec_type`, then `$field` is a Vec, which needs to have its individual elements serialized. +/// +/// For example, +/// ``` +/// # use lightning::impl_writeable_tlv_based; +/// struct LightningMessage { +/// tlv_integer: u32, +/// tlv_default_integer: u32, +/// tlv_optional_integer: Option, +/// tlv_vec_type_integer: Vec, +/// } +/// +/// impl_writeable_tlv_based!(LightningMessage, { +/// (0, tlv_integer, required), +/// (1, tlv_default_integer, (default_value, 7)), +/// (2, tlv_optional_integer, option), +/// (3, tlv_vec_type_integer, vec_type), +/// }); +/// ``` +/// +/// [`Readable`]: crate::util::ser::Readable +/// [`Writeable`]: crate::util::ser::Writeable +#[macro_export] macro_rules! impl_writeable_tlv_based { ($st: ident, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => { impl $crate::util::ser::Writeable for $st { fn write(&self, writer: &mut W) -> Result<(), $crate::io::Error> { - write_tlv_fields!(writer, { + $crate::write_tlv_fields!(writer, { $(($type, self.$field, $fieldty)),* }); Ok(()) @@ -496,7 +669,7 @@ macro_rules! impl_writeable_tlv_based { #[allow(unused_mut)] let mut len = $crate::util::ser::LengthCalculatingWriter(0); $( - get_varint_length_prefixed_tlv_length!(len, $type, self.$field, $fieldty); + $crate::_get_varint_length_prefixed_tlv_length!(len, $type, self.$field, $fieldty); )* len.0 }; @@ -508,12 +681,12 @@ macro_rules! impl_writeable_tlv_based { impl $crate::util::ser::Readable for $st { fn read(reader: &mut R) -> Result { - init_and_read_tlv_fields!(reader, { + $crate::_init_and_read_tlv_fields!(reader, { $(($type, $field, $fieldty)),* }); Ok(Self { $( - $field: init_tlv_based_struct_field!($field, $fieldty) + $field: $crate::_init_tlv_based_struct_field!($field, $fieldty) ),* }) } @@ -560,12 +733,12 @@ macro_rules! tlv_stream { impl $crate::util::ser::SeekReadable for $name { fn read(reader: &mut R) -> Result { $( - init_tlv_field_var!($field, option); + _init_tlv_field_var!($field, option); )* let rewind = |cursor: &mut R, offset: usize| { cursor.seek($crate::io::SeekFrom::Current(-(offset as i64))).expect(""); }; - decode_tlv_stream_range!(reader, $range, rewind, { + _decode_tlv_stream_range!(reader, $range, rewind, { $(($type, $field, (option, encoding: $fieldty))),* }); @@ -621,13 +794,18 @@ macro_rules! _impl_writeable_tlv_based_enum_common { } } -/// Implement MaybeReadable and Writeable for an enum, with struct variants stored as TLVs and +/// Implement [`MaybeReadable`] and [`Writeable`] for an enum, with struct variants stored as TLVs and /// tuple variants stored directly. /// -/// This is largely identical to `impl_writeable_tlv_based_enum`, except that odd variants will -/// return `Ok(None)` instead of `Err(UnknownRequiredFeature)`. It should generally be preferred -/// when `MaybeReadable` is practical instead of just `Readable` as it provides an upgrade path for +/// This is largely identical to [`impl_writeable_tlv_based_enum`], except that odd variants will +/// return `Ok(None)` instead of `Err(`[`DecodeError::UnknownRequiredFeature`]`)`. It should generally be preferred +/// when [`MaybeReadable`] is practical instead of just [`Readable`] as it provides an upgrade path for /// new variants to be added which are simply ignored by existing clients. +/// +/// [`MaybeReadable`]: crate::util::ser::MaybeReadable +/// [`Writeable`]: crate::util::ser::Writeable +/// [`DecodeError::UnknownRequiredFeature`]: crate::ln::msgs::DecodeError::UnknownRequiredFeature +/// [`Readable`]: crate::util::ser::Readable macro_rules! impl_writeable_tlv_based_enum_upgradable { ($st: ident, $(($variant_id: expr, $variant_name: ident) => {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*} @@ -646,12 +824,12 @@ macro_rules! impl_writeable_tlv_based_enum_upgradable { // Because read_tlv_fields creates a labeled loop, we cannot call it twice // in the same function body. Instead, we define a closure and call it. let f = || { - init_and_read_tlv_fields!(reader, { + _init_and_read_tlv_fields!(reader, { $(($type, $field, $fieldty)),* }); Ok(Some($st::$variant_name { $( - $field: init_tlv_based_struct_field!($field, $fieldty) + $field: _init_tlv_based_struct_field!($field, $fieldty) ),* })) }; @@ -669,7 +847,7 @@ macro_rules! impl_writeable_tlv_based_enum_upgradable { } } -/// Implement Readable and Writeable for an enum, with struct variants stored as TLVs and tuple +/// Implement [`Readable`] and [`Writeable`] for an enum, with struct variants stored as TLVs and tuple /// variants stored directly. /// The format is, for example /// impl_writeable_tlv_based_enum!(EnumName, @@ -678,7 +856,11 @@ macro_rules! impl_writeable_tlv_based_enum_upgradable { /// (2, TupleVariantA), (3, TupleVariantB), /// ); /// The type is written as a single byte, followed by any variant data. -/// Attempts to read an unknown type byte result in DecodeError::UnknownRequiredFeature. +/// Attempts to read an unknown type byte result in [`DecodeError::UnknownRequiredFeature`]. +/// +/// [`Readable`]: crate::util::ser::Readable +/// [`Writeable`]: crate::util::ser::Writeable +/// [`DecodeError::UnknownRequiredFeature`]: crate::ln::msgs::DecodeError::UnknownRequiredFeature macro_rules! impl_writeable_tlv_based_enum { ($st: ident, $(($variant_id: expr, $variant_name: ident) => {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*} @@ -696,12 +878,12 @@ macro_rules! impl_writeable_tlv_based_enum { // Because read_tlv_fields creates a labeled loop, we cannot call it twice // in the same function body. Instead, we define a closure and call it. let f = || { - init_and_read_tlv_fields!(reader, { + _init_and_read_tlv_fields!(reader, { $(($type, $field, $fieldty)),* }); Ok($st::$variant_name { $( - $field: init_tlv_based_struct_field!($field, $fieldty) + $field: _init_tlv_based_struct_field!($field, $fieldty) ),* }) }; @@ -910,27 +1092,27 @@ mod tests { let mut stream = VecWriter(Vec::new()); stream.0.clear(); - encode_varint_length_prefixed_tlv!(&mut stream, {(1, 1u8, required), (42, None::, option)}); + _encode_varint_length_prefixed_tlv!(&mut stream, {(1, 1u8, required), (42, None::, option)}); assert_eq!(stream.0, ::hex::decode("03010101").unwrap()); stream.0.clear(); - encode_varint_length_prefixed_tlv!(&mut stream, {(1, Some(1u8), option)}); + _encode_varint_length_prefixed_tlv!(&mut stream, {(1, Some(1u8), option)}); assert_eq!(stream.0, ::hex::decode("03010101").unwrap()); stream.0.clear(); - encode_varint_length_prefixed_tlv!(&mut stream, {(4, 0xabcdu16, required), (42, None::, option)}); + _encode_varint_length_prefixed_tlv!(&mut stream, {(4, 0xabcdu16, required), (42, None::, option)}); assert_eq!(stream.0, ::hex::decode("040402abcd").unwrap()); stream.0.clear(); - encode_varint_length_prefixed_tlv!(&mut stream, {(42, None::, option), (0xff, 0xabcdu16, required)}); + _encode_varint_length_prefixed_tlv!(&mut stream, {(42, None::, option), (0xff, 0xabcdu16, required)}); assert_eq!(stream.0, ::hex::decode("06fd00ff02abcd").unwrap()); stream.0.clear(); - encode_varint_length_prefixed_tlv!(&mut stream, {(0, 1u64, required), (42, None::, option), (0xff, HighZeroBytesDroppedBigSize(0u64), required)}); + _encode_varint_length_prefixed_tlv!(&mut stream, {(0, 1u64, required), (42, None::, option), (0xff, HighZeroBytesDroppedBigSize(0u64), required)}); assert_eq!(stream.0, ::hex::decode("0e00080000000000000001fd00ff00").unwrap()); stream.0.clear(); - encode_varint_length_prefixed_tlv!(&mut stream, {(0, Some(1u64), option), (0xff, HighZeroBytesDroppedBigSize(0u64), required)}); + _encode_varint_length_prefixed_tlv!(&mut stream, {(0, Some(1u64), option), (0xff, HighZeroBytesDroppedBigSize(0u64), required)}); assert_eq!(stream.0, ::hex::decode("0e00080000000000000001fd00ff00").unwrap()); Ok(()) -- 2.39.5