-macro_rules! encode_tlv {
- ($stream: expr, {$(($type: expr, $field: expr)),*}) => { {
- use util::ser::{BigSize, LengthCalculatingWriter};
+// This file is Copyright its original authors, visible in version control
+// history.
+//
+// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
+// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
+// You may not use this file except in accordance with one or both of these
+// licenses.
+
+//! Some macros that implement [`Readable`]/[`Writeable`] traits for lightning messages.
+//! They also handle serialization and deserialization of TLVs.
+//!
+//! [`Readable`]: crate::util::ser::Readable
+//! [`Writeable`]: crate::util::ser::Writeable
+
+/// Implements serialization for a single TLV record.
+/// This is exported for use by other exported macros, do not use directly.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! _encode_tlv {
+ ($stream: expr, $type: expr, $field: expr, (default_value, $default: expr)) => {
+ $crate::_encode_tlv!($stream, $type, $field, required)
+ };
+ ($stream: expr, $type: expr, $field: expr, (static_value, $value: expr)) => {
+ let _ = &$field; // Ensure we "use" the $field
+ };
+ ($stream: expr, $type: expr, $field: expr, required) => {
+ BigSize($type).write($stream)?;
+ BigSize($field.serialized_length() as u64).write($stream)?;
+ $field.write($stream)?;
+ };
+ ($stream: expr, $type: expr, $field: expr, vec_type) => {
+ $crate::_encode_tlv!($stream, $type, $crate::util::ser::WithoutLength(&$field), required);
+ };
+ ($stream: expr, $optional_type: expr, $optional_field: expr, option) => {
+ if let Some(ref field) = $optional_field {
+ BigSize($optional_type).write($stream)?;
+ BigSize(field.serialized_length() as u64).write($stream)?;
+ field.write($stream)?;
+ }
+ };
+ ($stream: expr, $type: expr, $field: expr, (option, encoding: ($fieldty: ty, $encoding: ident))) => {
+ $crate::_encode_tlv!($stream, $type, $field.map(|f| $encoding(f)), option);
+ };
+ ($stream: expr, $type: expr, $field: expr, (option, encoding: $fieldty: ty)) => {
+ $crate::_encode_tlv!($stream, $type, $field, option);
+ };
+}
+
+/// Panics if the last seen TLV type is not numerically less than the TLV type currently being checked.
+/// This is exported for use by other exported macros, do not use directly.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! _check_encoded_tlv_order {
+ ($last_type: expr, $type: expr, (static_value, $value: expr)) => { };
+ ($last_type: expr, $type: expr, $fieldty: tt) => {
+ if let Some(t) = $last_type {
+ #[allow(unused_comparisons)] // Note that $type may be 0 making the following comparison always false
+ (debug_assert!(t < $type))
+ }
+ $last_type = Some($type);
+ };
+}
+
+/// 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<W: lightning::util::ser::Writer> (stream: &mut W) -> Result<(), lightning::io::Error> {
+/// let mut required_value = 0u64;
+/// let mut optional_value: Option<u64> = 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)]
+ use $crate::{
+ ln::msgs::DecodeError,
+ util::ser,
+ util::ser::BigSize,
+ util::ser::Writeable,
+ };
+
$(
- BigSize($type).write($stream)?;
- let mut len_calc = LengthCalculatingWriter(0);
- $field.write(&mut len_calc)?;
- BigSize(len_calc.0 as u64).write($stream)?;
- $field.write($stream)?;
+ $crate::_encode_tlv!($stream, $type, $field, $fieldty);
)*
+
+ #[allow(unused_mut, unused_variables, unused_assignments)]
+ #[cfg(debug_assertions)]
+ {
+ let mut last_seen: Option<u64> = None;
+ $(
+ $crate::_check_encoded_tlv_order!(last_seen, $type, $fieldty);
+ )*
+ }
} }
}
-macro_rules! encode_varint_length_prefixed_tlv {
- ($stream: expr, {$(($type: expr, $field: expr)),*}) => { {
- use util::ser::{BigSize, LengthCalculatingWriter};
- let mut len = LengthCalculatingWriter(0);
- {
+/// Adds the length of the serialized field to a [`LengthCalculatingWriter`].
+/// This is exported for use by other exported macros, do not use directly.
+///
+/// [`LengthCalculatingWriter`]: crate::util::ser::LengthCalculatingWriter
+#[doc(hidden)]
+#[macro_export]
+macro_rules! _get_varint_length_prefixed_tlv_length {
+ ($len: expr, $type: expr, $field: expr, (default_value, $default: expr)) => {
+ $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $field, required)
+ };
+ ($len: expr, $type: expr, $field: expr, (static_value, $value: expr)) => {
+ };
+ ($len: expr, $type: expr, $field: expr, required) => {
+ BigSize($type).write(&mut $len).expect("No in-memory data may fail to serialize");
+ let field_len = $field.serialized_length();
+ BigSize(field_len as u64).write(&mut $len).expect("No in-memory data may fail to serialize");
+ $len.0 += field_len;
+ };
+ ($len: expr, $type: expr, $field: expr, vec_type) => {
+ $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $crate::util::ser::WithoutLength(&$field), required);
+ };
+ ($len: expr, $optional_type: expr, $optional_field: expr, option) => {
+ if let Some(ref field) = $optional_field {
+ BigSize($optional_type).write(&mut $len).expect("No in-memory data may fail to serialize");
+ let field_len = field.serialized_length();
+ BigSize(field_len as u64).write(&mut $len).expect("No in-memory data may fail to serialize");
+ $len.0 += field_len;
+ }
+ };
+}
+
+/// See the documentation of [`write_tlv_fields`].
+/// This is exported for use by other exported macros, do not use directly.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! _encode_varint_length_prefixed_tlv {
+ ($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);
$(
- BigSize($type).write(&mut len)?;
- let mut field_len = LengthCalculatingWriter(0);
- $field.write(&mut field_len)?;
- BigSize(field_len.0 as u64).write(&mut len)?;
- len.0 += field_len.0;
+ $crate::_get_varint_length_prefixed_tlv_length!(len, $type, $field, $fieldty);
)*
+ len.0
+ };
+ BigSize(len as u64).write($stream)?;
+ $crate::encode_tlv_stream!($stream, { $(($type, $field, $fieldty)),* });
+ } }
+}
+
+/// Errors if there are missing required TLV types between the last seen type and the type currently being processed.
+/// This is exported for use by other exported macros, do not use directly.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! _check_decoded_tlv_order {
+ ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (default_value, $default: expr)) => {{
+ #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always false
+ let invalid_order = ($last_seen_type.is_none() || $last_seen_type.unwrap() < $type) && $typ.0 > $type;
+ if invalid_order {
+ $field = $default.into();
}
+ }};
+ ($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 $type may be 0 making the second comparison always false
+ let invalid_order = ($last_seen_type.is_none() || $last_seen_type.unwrap() < $type) && $typ.0 > $type;
+ if invalid_order {
+ return Err(DecodeError::InvalidValue);
+ }
+ }};
+ ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, option) => {{
+ // no-op
+ }};
+ ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, vec_type) => {{
+ // no-op
+ }};
+ ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, ignorable) => {{
+ // no-op
+ }};
+ ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {{
+ // no-op
+ }};
+ ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (option, encoding: $encoding: tt)) => {{
+ // no-op
+ }};
+}
- BigSize(len.0 as u64).write($stream)?;
- encode_tlv!($stream, {
- $(($type, $field)),*
- });
+/// Errors if there are missing required TLV types after the last seen type.
+/// This is exported for use by other exported macros, do not use directly.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! _check_missing_tlv {
+ ($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 false
+ let missing_req_type = $last_seen_type.is_none() || $last_seen_type.unwrap() < $type;
+ if missing_req_type {
+ $field = $default.into();
+ }
+ }};
+ ($last_seen_type: expr, $type: expr, $field: expr, (static_value, $value: expr)) => {
+ $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 false
+ let missing_req_type = $last_seen_type.is_none() || $last_seen_type.unwrap() < $type;
+ if missing_req_type {
+ return Err(DecodeError::InvalidValue);
+ }
+ }};
+ ($last_seen_type: expr, $type: expr, $field: ident, vec_type) => {{
+ // no-op
+ }};
+ ($last_seen_type: expr, $type: expr, $field: ident, option) => {{
+ // no-op
+ }};
+ ($last_seen_type: expr, $type: expr, $field: ident, ignorable) => {{
+ // no-op
+ }};
+ ($last_seen_type: expr, $type: expr, $field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {{
+ // no-op
+ }};
+ ($last_seen_type: expr, $type: expr, $field: ident, (option, encoding: $encoding: tt)) => {{
+ // no-op
+ }};
+}
+
+/// Implements deserialization for a single TLV record.
+/// This is exported for use by other exported macros, do not use directly.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! _decode_tlv {
+ ($reader: expr, $field: ident, (default_value, $default: expr)) => {{
+ $crate::_decode_tlv!($reader, $field, required)
+ }};
+ ($reader: expr, $field: ident, (static_value, $value: expr)) => {{
+ }};
+ ($reader: expr, $field: ident, required) => {{
+ $field = $crate::util::ser::Readable::read(&mut $reader)?;
+ }};
+ ($reader: expr, $field: ident, vec_type) => {{
+ let f: $crate::util::ser::WithoutLength<Vec<_>> = $crate::util::ser::Readable::read(&mut $reader)?;
+ $field = Some(f.0);
+ }};
+ ($reader: expr, $field: ident, option) => {{
+ $field = Some($crate::util::ser::Readable::read(&mut $reader)?);
+ }};
+ ($reader: expr, $field: ident, ignorable) => {{
+ $field = $crate::util::ser::MaybeReadable::read(&mut $reader)?;
+ }};
+ ($reader: expr, $field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {{
+ $field = Some($trait::read(&mut $reader $(, $read_arg)*)?);
+ }};
+ ($reader: expr, $field: ident, (option, encoding: ($fieldty: ty, $encoding: ident))) => {{
+ $field = {
+ let field: $encoding<$fieldty> = ser::Readable::read(&mut $reader)?;
+ Some(field.0)
+ };
+ }};
+ ($reader: expr, $field: ident, (option, encoding: $fieldty: ty)) => {{
+ $crate::_decode_tlv!($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 == $type }
+}
+
+/// Implements the TLVs deserialization part in a [`Readable`] implementation of a struct.
+///
+/// This should be called inside a method which returns `Result<_, `[`DecodeError`]`>`, such as
+/// [`Readable::read`]. It will either return an `Err` or ensure all `required` fields have been
+/// read and optionally read `optional` fields.
+///
+/// `$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 `$type`-order.
+///
+/// Note that the lightning TLV requirements require that a single type not appear more than once,
+/// that TLVs are sorted in type-ascending order, and that any even types be understood by the
+/// decoder.
+///
+/// For example,
+/// ```
+/// # use lightning::decode_tlv_stream;
+/// # fn read<R: lightning::io::Read> (stream: R) -> Result<(), lightning::ln::msgs::DecodeError> {
+/// let mut required_value = 0u64;
+/// let mut optional_value: Option<u64> = None;
+/// decode_tlv_stream!(stream, {
+/// (0, required_value, required),
+/// (2, optional_value, option),
+/// });
+/// // At this point, `required_value` has been overwritten with the TLV with type 0.
+/// // `optional_value` may have been overwritten, setting it to `Some` if a TLV with type 2 was
+/// // present.
+/// # Ok(())
+/// # }
+/// ```
+///
+/// [`Readable`]: crate::util::ser::Readable
+/// [`DecodeError`]: crate::ln::msgs::DecodeError
+/// [`Readable::read`]: crate::util::ser::Readable::read
+/// [`Read`]: crate::io::Read
+/// [`DecodeError::ShortRead`]: crate::ln::msgs::DecodeError::ShortRead
+#[macro_export]
+macro_rules! decode_tlv_stream {
+ ($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!() };
+ _decode_tlv_stream_range!(
+ $stream, .., rewind, {$(($type, $field, $fieldty)),*} $(, $decode_custom_tlv)?
+ );
} }
}
-macro_rules! decode_tlv {
- ($stream: expr, {$(($reqtype: expr, $reqfield: ident)),*}, {$(($type: expr, $field: ident)),*}) => { {
- use ln::msgs::DecodeError;
+#[doc(hidden)]
+#[macro_export]
+macro_rules! _decode_tlv_stream_range {
+ ($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<u64> = None;
+ let mut stream_ref = $stream;
'tlv_read: loop {
- use util::ser;
+ use $crate::util::ser;
// First decode the type of this TLV:
let typ: ser::BigSize = {
// We track whether any bytes were read during the consensus_decode call to
// determine whether we should break or return ShortRead if we get an
// UnexpectedEof. This should in every case be largely cosmetic, but its nice to
- // pass the TLV test vectors exactly, which requre this distinction.
- let mut tracking_reader = ser::ReadTrackingReader::new($stream);
- match ser::Readable::read(&mut tracking_reader) {
+ // 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) => {
if !tracking_reader.have_read {
- break 'tlv_read
+ break 'tlv_read;
} else {
- Err(DecodeError::ShortRead)?
+ return Err(DecodeError::ShortRead);
}
},
- Err(e) => Err(e)?,
- Ok(t) => t,
+ Err(e) => return Err(e),
+ Ok(t) => if $range.contains(&t.0) { t } else {
+ drop(tracking_reader);
+
+ // Assumes the type id is minimally encoded, which is enforced on read.
+ use $crate::util::ser::Writeable;
+ let bytes_read = t.serialized_length();
+ $rewind(stream_ref, bytes_read);
+ break 'tlv_read;
+ },
}
};
// Types must be unique and monotonically increasing:
match last_seen_type {
Some(t) if typ.0 <= t => {
- Err(DecodeError::InvalidValue)?
+ return Err(DecodeError::InvalidValue);
},
_ => {},
}
- // As we read types, make sure we hit every required type:
- $(if (last_seen_type.is_none() || last_seen_type.unwrap() < $reqtype) && typ.0 > $reqtype {
- Err(DecodeError::InvalidValue)?
+ // As we read types, make sure we hit every required type between `last_seen_type` and `typ`:
+ $({
+ $crate::_check_decoded_tlv_order!(last_seen_type, typ, $type, $field, $fieldty);
})*
last_seen_type = Some(typ.0);
// Finally, read the length and value itself:
- let length: ser::BigSize = Readable::read($stream)?;
- let mut s = ser::FixedLengthReader::new($stream, length.0);
+ 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 {
- $($reqtype => {
- $reqfield = ser::Readable::read(&mut s)?;
+ $(_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
- Err(DecodeError::InvalidValue)?
+ return Err(DecodeError::InvalidValue);
}
},)*
- $($type => {
- $field = Some(ser::Readable::read(&mut s)?);
- if s.bytes_remain() {
- s.eat_remaining()?; // Return ShortRead if there's actually not enough bytes
- Err(DecodeError::InvalidValue)?
+ t => {
+ $(
+ if $decode_custom_tlv(t, &mut s)? {
+ // If a custom TLV was successfully read (i.e. decode_custom_tlv returns true),
+ // continue to the next TLV read.
+ s.eat_remaining()?;
+ continue 'tlv_read;
+ }
+ )?
+ if t % 2 == 0 {
+ return Err(DecodeError::UnknownRequiredFeature);
}
- },)*
- x if x % 2 == 0 => {
- Err(DecodeError::UnknownRequiredFeature)?
- },
- _ => {},
+ }
}
s.eat_remaining()?;
}
// Make sure we got to each required type after we've read every TLV:
- $(if last_seen_type.is_none() || last_seen_type.unwrap() < $reqtype {
- Err(DecodeError::InvalidValue)?
+ $({
+ $crate::_check_missing_tlv!(last_seen_type, $type, $field, $fieldty);
})*
} }
}
+macro_rules! impl_writeable_msg {
+ ($st:ident, {$($field:ident),* $(,)*}, {$(($type: expr, $tlvfield: ident, $fieldty: tt)),* $(,)*}) => {
+ impl $crate::util::ser::Writeable for $st {
+ fn write<W: $crate::util::ser::Writer>(&self, w: &mut W) -> Result<(), $crate::io::Error> {
+ $( self.$field.write(w)?; )*
+ encode_tlv_stream!(w, {$(($type, self.$tlvfield, $fieldty)),*});
+ Ok(())
+ }
+ }
+ impl $crate::util::ser::Readable for $st {
+ fn read<R: $crate::io::Read>(r: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
+ $(let $field = $crate::util::ser::Readable::read(r)?;)*
+ $(_init_tlv_field_var!($tlvfield, $fieldty);)*
+ decode_tlv_stream!(r, {$(($type, $tlvfield, $fieldty)),*});
+ Ok(Self {
+ $($field),*,
+ $($tlvfield),*
+ })
+ }
+ }
+ }
+}
+
macro_rules! impl_writeable {
- ($st:ident, $len: expr, {$($field:ident),*}) => {
- impl ::util::ser::Writeable for $st {
- fn write<W: ::util::ser::Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
- if $len != 0 {
- w.size_hint($len);
- }
+ ($st:ident, {$($field:ident),*}) => {
+ impl $crate::util::ser::Writeable for $st {
+ fn write<W: $crate::util::ser::Writer>(&self, w: &mut W) -> Result<(), $crate::io::Error> {
$( self.$field.write(w)?; )*
Ok(())
}
+
+ #[inline]
+ fn serialized_length(&self) -> usize {
+ let mut len_calc = 0;
+ $( len_calc += self.$field.serialized_length(); )*
+ return len_calc;
+ }
+ }
+
+ impl $crate::util::ser::Readable for $st {
+ fn read<R: $crate::io::Read>(r: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
+ Ok(Self {
+ $($field: $crate::util::ser::Readable::read(r)?),*
+ })
+ }
+ }
+ }
+}
+
+/// Write out two bytes to indicate the version of an object.
+///
+/// $this_version represents a unique version of a type. Incremented whenever the type's
+/// serialization format has changed or has a new interpretation. Used by a type's reader to
+/// determine how to interpret fields or if it can understand a serialized object.
+///
+/// $min_version_that_can_read_this is the minimum reader version which can understand this
+/// serialized object. Previous versions will simply err with a [`DecodeError::UnknownVersion`].
+///
+/// Updates to either `$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])?;
+ $stream.write_all(&[$min_version_that_can_read_this; 1])?;
+ }
+}
+
+/// 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.
+///
+/// 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)),* $(,)*}) => {
+ $crate::_encode_varint_length_prefixed_tlv!($stream, {$(($type, $field, $fieldty)),*})
+ }
+}
+
+/// Reads a prefix added by [`write_ver_prefix`], above. Takes the current version of the
+/// serialization logic for this object. This is compared against the
+/// `$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)?;
+ let min_ver: u8 = Readable::read($stream)?;
+ if min_ver > $this_version {
+ return Err(DecodeError::UnknownVersion);
+ }
+ ver
+ } }
+}
+
+/// Reads a suffix added by [`write_tlv_fields`].
+///
+/// [`write_tlv_fields`]: crate::write_tlv_fields
+#[macro_export]
+macro_rules! read_tlv_fields {
+ ($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);
+ $crate::decode_tlv_stream!(&mut rd, {$(($type, $field, $fieldty)),*});
+ rd.eat_remaining().map_err(|_| $crate::ln::msgs::DecodeError::ShortRead)?;
+ } }
+}
+
+/// Initializes the struct fields.
+///
+/// This is exported for use by other exported macros, do not use directly.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! _init_tlv_based_struct_field {
+ ($field: ident, (default_value, $default: expr)) => {
+ $field.0.unwrap()
+ };
+ ($field: ident, (static_value, $value: expr)) => {
+ $field
+ };
+ ($field: ident, option) => {
+ $field
+ };
+ ($field: ident, required) => {
+ $field.0.unwrap()
+ };
+ ($field: ident, vec_type) => {
+ $field.unwrap()
+ };
+}
+
+/// Initializes the variable we are going to read the TLV into.
+///
+/// This is exported for use by other exported macros, do not use directly.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! _init_tlv_field_var {
+ ($field: ident, (default_value, $default: expr)) => {
+ let mut $field = $crate::util::ser::OptionDeserWrapper(None);
+ };
+ ($field: ident, (static_value, $value: expr)) => {
+ let $field;
+ };
+ ($field: ident, required) => {
+ let mut $field = $crate::util::ser::OptionDeserWrapper(None);
+ };
+ ($field: ident, vec_type) => {
+ let mut $field = Some(Vec::new());
+ };
+ ($field: ident, option) => {
+ let mut $field = None;
+ };
+}
+
+/// Equivalent to running [`_init_tlv_field_var`] then [`read_tlv_fields`].
+///
+/// This is exported for use by other exported macros, do not use directly.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! _init_and_read_tlv_fields {
+ ($reader: ident, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => {
+ $(
+ $crate::_init_tlv_field_var!($field, $fieldty);
+ )*
+
+ $crate::read_tlv_fields!($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 `(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 `$field` is a Vec, which needs to have its individual elements serialized.
+///
+/// For example,
+/// ```
+/// # use lightning::impl_writeable_tlv_based;
+/// struct LightningMessage {
+/// tlv_integer: u32,
+/// tlv_default_integer: u32,
+/// tlv_optional_integer: Option<u32>,
+/// tlv_vec_type_integer: Vec<u32>,
+/// }
+///
+/// impl_writeable_tlv_based!(LightningMessage, {
+/// (0, tlv_integer, required),
+/// (1, tlv_default_integer, (default_value, 7)),
+/// (2, tlv_optional_integer, option),
+/// (3, tlv_vec_type_integer, vec_type),
+/// });
+/// ```
+///
+/// [`Readable`]: crate::util::ser::Readable
+/// [`Writeable`]: crate::util::ser::Writeable
+#[macro_export]
+macro_rules! impl_writeable_tlv_based {
+ ($st: ident, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => {
+ impl $crate::util::ser::Writeable for $st {
+ fn write<W: $crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), $crate::io::Error> {
+ $crate::write_tlv_fields!(writer, {
+ $(($type, self.$field, $fieldty)),*
+ });
+ Ok(())
+ }
+
+ #[inline]
+ fn serialized_length(&self) -> usize {
+ use $crate::util::ser::BigSize;
+ let len = {
+ #[allow(unused_mut)]
+ let mut len = $crate::util::ser::LengthCalculatingWriter(0);
+ $(
+ $crate::_get_varint_length_prefixed_tlv_length!(len, $type, self.$field, $fieldty);
+ )*
+ len.0
+ };
+ let mut len_calc = $crate::util::ser::LengthCalculatingWriter(0);
+ BigSize(len as u64).write(&mut len_calc).expect("No in-memory data may fail to serialize");
+ len + len_calc.0
+ }
}
- impl<R: ::std::io::Read> ::util::ser::Readable<R> for $st {
- fn read(r: &mut R) -> Result<Self, ::ln::msgs::DecodeError> {
+ impl $crate::util::ser::Readable for $st {
+ fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
+ $crate::_init_and_read_tlv_fields!(reader, {
+ $(($type, $field, $fieldty)),*
+ });
Ok(Self {
- $($field: ::util::ser::Readable::read(r)?),*
+ $(
+ $field: $crate::_init_tlv_based_struct_field!($field, $fieldty)
+ ),*
})
}
}
}
}
-macro_rules! impl_writeable_len_match {
- ($st:ident, {$({$m: pat, $l: expr}),*}, {$($field:ident),*}) => {
- impl Writeable for $st {
- fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
- w.size_hint(match *self {
- $($m => $l,)*
+
+/// Defines a struct for a TLV stream and a similar struct using references for non-primitive types,
+/// implementing [`Readable`] for the former and [`Writeable`] for the latter. Useful as an
+/// intermediary format when reading or writing a type encoded as a TLV stream. Note that each field
+/// representing a TLV record has its type wrapped with an [`Option`]. A tuple consisting of a type
+/// and a serialization wrapper may be given in place of a type when custom serialization is
+/// required.
+///
+/// [`Readable`]: crate::util::ser::Readable
+/// [`Writeable`]: crate::util::ser::Writeable
+macro_rules! tlv_stream {
+ ($name:ident, $nameref:ident, $range:expr, {
+ $(($type:expr, $field:ident : $fieldty:tt)),* $(,)*
+ }) => {
+ #[derive(Debug)]
+ pub(super) struct $name {
+ $(
+ pub(super) $field: Option<tlv_record_type!($fieldty)>,
+ )*
+ }
+
+ #[derive(Debug, PartialEq)]
+ pub(super) struct $nameref<'a> {
+ $(
+ pub(super) $field: Option<tlv_record_ref_type!($fieldty)>,
+ )*
+ }
+
+ impl<'a> $crate::util::ser::Writeable for $nameref<'a> {
+ fn write<W: $crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), $crate::io::Error> {
+ encode_tlv_stream!(writer, {
+ $(($type, self.$field, (option, encoding: $fieldty))),*
});
- $( self.$field.write(w)?; )*
Ok(())
}
}
- impl<R: ::std::io::Read> Readable<R> for $st {
- fn read(r: &mut R) -> Result<Self, DecodeError> {
+ impl $crate::util::ser::SeekReadable for $name {
+ fn read<R: $crate::io::Read + $crate::io::Seek>(reader: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
+ $(
+ _init_tlv_field_var!($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, {
+ $(($type, $field, (option, encoding: $fieldty))),*
+ });
+
Ok(Self {
- $($field: Readable::read(r)?),*
+ $(
+ $field: $field
+ ),*
})
}
}
}
}
+macro_rules! tlv_record_type {
+ (($type:ty, $wrapper:ident)) => { $type };
+ ($type:ty) => { $type };
+}
+
+macro_rules! tlv_record_ref_type {
+ (char) => { char };
+ (u8) => { u8 };
+ ((u16, $wrapper: ident)) => { u16 };
+ ((u32, $wrapper: ident)) => { u32 };
+ ((u64, $wrapper: ident)) => { u64 };
+ (($type:ty, $wrapper:ident)) => { &'a $type };
+ ($type:ty) => { &'a $type };
+}
+
+macro_rules! _impl_writeable_tlv_based_enum_common {
+ ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
+ {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
+ ),* $(,)*;
+ $(($tuple_variant_id: expr, $tuple_variant_name: ident)),* $(,)*) => {
+ impl $crate::util::ser::Writeable for $st {
+ fn write<W: $crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), $crate::io::Error> {
+ match self {
+ $($st::$variant_name { $(ref $field),* } => {
+ let id: u8 = $variant_id;
+ id.write(writer)?;
+ write_tlv_fields!(writer, {
+ $(($type, *$field, $fieldty)),*
+ });
+ }),*
+ $($st::$tuple_variant_name (ref field) => {
+ let id: u8 = $tuple_variant_id;
+ id.write(writer)?;
+ field.write(writer)?;
+ }),*
+ }
+ Ok(())
+ }
+ }
+ }
+}
+
+/// Implement [`Readable`] and [`Writeable`] for an enum, with struct variants stored as TLVs and tuple
+/// variants stored directly.
+/// The format is, for example
+/// ```ignore
+/// impl_writeable_tlv_based_enum!(EnumName,
+/// (0, StructVariantA) => {(0, required_variant_field, required), (1, optional_variant_field, option)},
+/// (1, StructVariantB) => {(0, variant_field_a, required), (1, variant_field_b, required), (2, variant_vec_field, vec_type)};
+/// (2, TupleVariantA), (3, TupleVariantB),
+/// );
+/// ```
+/// The type is written as a single byte, followed by any variant data.
+/// Attempts to read an unknown type byte result in [`DecodeError::UnknownRequiredFeature`].
+///
+/// [`Readable`]: crate::util::ser::Readable
+/// [`Writeable`]: crate::util::ser::Writeable
+/// [`DecodeError::UnknownRequiredFeature`]: crate::ln::msgs::DecodeError::UnknownRequiredFeature
+#[macro_export]
+macro_rules! impl_writeable_tlv_based_enum {
+ ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
+ {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
+ ),* $(,)*;
+ $(($tuple_variant_id: expr, $tuple_variant_name: ident)),* $(,)*) => {
+ _impl_writeable_tlv_based_enum_common!($st,
+ $(($variant_id, $variant_name) => {$(($type, $field, $fieldty)),*}),*;
+ $(($tuple_variant_id, $tuple_variant_name)),*);
+
+ impl $crate::util::ser::Readable for $st {
+ fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
+ let id: u8 = $crate::util::ser::Readable::read(reader)?;
+ match id {
+ $($variant_id => {
+ // 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, {
+ $(($type, $field, $fieldty)),*
+ });
+ Ok($st::$variant_name {
+ $(
+ $field: _init_tlv_based_struct_field!($field, $fieldty)
+ ),*
+ })
+ };
+ f()
+ }),*
+ $($tuple_variant_id => {
+ Ok($st::$tuple_variant_name(Readable::read(reader)?))
+ }),*
+ _ => {
+ Err($crate::ln::msgs::DecodeError::UnknownRequiredFeature)
+ },
+ }
+ }
+ }
+ }
+}
+
+/// Implement [`MaybeReadable`] and [`Writeable`] for an enum, with struct variants stored as TLVs and
+/// tuple variants stored directly.
+///
+/// This is largely identical to [`impl_writeable_tlv_based_enum`], except that odd variants will
+/// return `Ok(None)` instead of `Err(`[`DecodeError::UnknownRequiredFeature`]`)`. It should generally be preferred
+/// when [`MaybeReadable`] is practical instead of just [`Readable`] as it provides an upgrade path for
+/// new variants to be added which are simply ignored by existing clients.
+///
+/// [`MaybeReadable`]: crate::util::ser::MaybeReadable
+/// [`Writeable`]: crate::util::ser::Writeable
+/// [`DecodeError::UnknownRequiredFeature`]: crate::ln::msgs::DecodeError::UnknownRequiredFeature
+/// [`Readable`]: crate::util::ser::Readable
+#[macro_export]
+macro_rules! impl_writeable_tlv_based_enum_upgradable {
+ ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
+ {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
+ ),* $(,)*
+ $(;
+ $(($tuple_variant_id: expr, $tuple_variant_name: ident)),* $(,)*)*) => {
+ _impl_writeable_tlv_based_enum_common!($st,
+ $(($variant_id, $variant_name) => {$(($type, $field, $fieldty)),*}),*;
+ $($(($tuple_variant_id, $tuple_variant_name)),*)*);
+
+ impl $crate::util::ser::MaybeReadable for $st {
+ fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Option<Self>, $crate::ln::msgs::DecodeError> {
+ let id: u8 = $crate::util::ser::Readable::read(reader)?;
+ match id {
+ $($variant_id => {
+ // 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, {
+ $(($type, $field, $fieldty)),*
+ });
+ Ok(Some($st::$variant_name {
+ $(
+ $field: _init_tlv_based_struct_field!($field, $fieldty)
+ ),*
+ }))
+ };
+ f()
+ }),*
+ $($($tuple_variant_id => {
+ Ok(Some($st::$tuple_variant_name(Readable::read(reader)?)))
+ }),*)*
+ _ if id % 2 == 1 => Ok(None),
+ _ => Err(DecodeError::UnknownRequiredFeature),
+ }
+ }
+ }
+ }
+}
+
#[cfg(test)]
mod tests {
- use std::io::{Cursor, Read};
- use ln::msgs::DecodeError;
- use util::ser::{Readable, Writeable, HighZeroBytesDroppedVarInt, VecWriter};
- use secp256k1::PublicKey;
+ use crate::io::{self, Cursor};
+ use crate::prelude::*;
+ use crate::ln::msgs::DecodeError;
+ use crate::util::ser::{Writeable, HighZeroBytesDroppedBigSize, VecWriter};
+ use bitcoin::secp256k1::PublicKey;
// The BOLT TLV test cases don't include any tests which use our "required-value" logic since
// the encoding layer in the BOLTs has no such concept, though it makes our macros easier to
let mut a: u64 = 0;
let mut b: u32 = 0;
let mut c: Option<u32> = None;
- decode_tlv!(&mut s, {(2, a), (3, b)}, {(4, c)});
+ decode_tlv_stream!(&mut s, {(2, a, required), (3, b, required), (4, c, option)});
Ok((a, b, c))
}
(0xdeadbeef1badbeef, 0x1bad1dea, Some(0x01020304)));
}
- impl<R: Read> Readable<R> for (PublicKey, u64, u64) {
- #[inline]
- fn read(reader: &mut R) -> Result<(PublicKey, u64, u64), DecodeError> {
- Ok((Readable::read(reader)?, Readable::read(reader)?, Readable::read(reader)?))
- }
- }
-
// BOLT TLV test cases
- fn tlv_reader_n1(s: &[u8]) -> Result<(Option<HighZeroBytesDroppedVarInt<u64>>, Option<u64>, Option<(PublicKey, u64, u64)>, Option<u16>), DecodeError> {
+ fn tlv_reader_n1(s: &[u8]) -> Result<(Option<HighZeroBytesDroppedBigSize<u64>>, Option<u64>, Option<(PublicKey, u64, u64)>, Option<u16>), DecodeError> {
let mut s = Cursor::new(s);
- let mut tlv1: Option<HighZeroBytesDroppedVarInt<u64>> = None;
+ let mut tlv1: Option<HighZeroBytesDroppedBigSize<u64>> = None;
let mut tlv2: Option<u64> = None;
let mut tlv3: Option<(PublicKey, u64, u64)> = None;
let mut tlv4: Option<u16> = None;
- decode_tlv!(&mut s, {}, {(1, tlv1), (2, tlv2), (3, tlv3), (254, tlv4)});
+ decode_tlv_stream!(&mut s, {(1, tlv1, option), (2, tlv2, option), (3, tlv3, option), (254, tlv4, option)});
Ok((tlv1, tlv2, tlv3, tlv4))
}
do_test!(concat!("fd00fe", "02", "0226"), None, None, None, Some(550));
}
- fn do_simple_test_tlv_write() -> Result<(), ::std::io::Error> {
+ fn do_simple_test_tlv_write() -> Result<(), io::Error> {
let mut stream = VecWriter(Vec::new());
stream.0.clear();
- encode_varint_length_prefixed_tlv!(&mut stream, { (1, 1u8) });
+ _encode_varint_length_prefixed_tlv!(&mut stream, {(1, 1u8, required), (42, None::<u64>, option)});
assert_eq!(stream.0, ::hex::decode("03010101").unwrap());
stream.0.clear();
- encode_varint_length_prefixed_tlv!(&mut stream, { (4, 0xabcdu16) });
+ _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::<u64>, option)});
assert_eq!(stream.0, ::hex::decode("040402abcd").unwrap());
stream.0.clear();
- encode_varint_length_prefixed_tlv!(&mut stream, { (0xff, 0xabcdu16) });
+ _encode_varint_length_prefixed_tlv!(&mut stream, {(42, None::<u64>, option), (0xff, 0xabcdu16, required)});
assert_eq!(stream.0, ::hex::decode("06fd00ff02abcd").unwrap());
stream.0.clear();
- encode_varint_length_prefixed_tlv!(&mut stream, { (0, 1u64), (0xff, HighZeroBytesDroppedVarInt(0u64)) });
+ _encode_varint_length_prefixed_tlv!(&mut stream, {(0, 1u64, required), (42, None::<u64>, 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)});
assert_eq!(stream.0, ::hex::decode("0e00080000000000000001fd00ff00").unwrap());
Ok(())