+
+/// 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)>,
+ )*
+ }
+
+ #[cfg_attr(test, derive(PartialEq))]
+ #[derive(Debug)]
+ 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))),*
+ });
+ Ok(())
+ }
+ }
+
+ 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: $field
+ ),*
+ })
+ }
+ }
+ }
+}
+
+macro_rules! tlv_record_type {
+ (($type:ty, $wrapper:ident)) => { $type };
+ (($type:ty, $wrapper:ident, $encoder:ty)) => { $type };
+ ($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, $wrapper:ident, $encoder:ty)) => { $encoder };
+ ($type:ty) => { &'a $type };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! _impl_writeable_tlv_based_enum_common {
+ ($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)?;
+ $crate::write_tlv_fields!(writer, {
+ $(($type, *$field, $fieldty)),*
+ });
+ }),*
+ $($st::$tuple_variant_name (ref field) => {
+ let id: u8 = $tuple_variant_id;
+ id.write(writer)?;
+ field.write(writer)?;
+ }),*
+ }
+ Ok(())
+ }
+ }
+ }
+}
+
+/// Implement [`Readable`] and [`Writeable`] for an enum, with struct variants stored as TLVs and tuple
+/// variants stored directly.
+/// The format is, for example
+/// ```ignore
+/// impl_writeable_tlv_based_enum!(EnumName,
+/// (0, StructVariantA) => {(0, required_variant_field, required), (1, optional_variant_field, option)},
+/// (1, StructVariantB) => {(0, variant_field_a, required), (1, variant_field_b, required), (2, variant_vec_field, optional_vec)};
+/// (2, TupleVariantA), (3, TupleVariantB),
+/// );
+/// ```
+/// The type is written as a single byte, followed by any variant data.
+/// Attempts to read an unknown type byte result in [`DecodeError::UnknownRequiredFeature`].
+///
+/// [`Readable`]: crate::util::ser::Readable
+/// [`Writeable`]: crate::util::ser::Writeable
+/// [`DecodeError::UnknownRequiredFeature`]: crate::ln::msgs::DecodeError::UnknownRequiredFeature
+#[macro_export]
+macro_rules! impl_writeable_tlv_based_enum {
+ ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
+ {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
+ ),* $(,)*;
+ $(($tuple_variant_id: expr, $tuple_variant_name: ident)),* $(,)*) => {
+ $crate::_impl_writeable_tlv_based_enum_common!($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 = || {
+ $crate::_init_and_read_tlv_fields!(reader, {
+ $(($type, $field, $fieldty)),*
+ });
+ Ok($st::$variant_name {
+ $(
+ $field: $crate::_init_tlv_based_struct_field!($field, $fieldty)
+ ),*
+ })
+ };
+ f()
+ }),*
+ $($tuple_variant_id => {
+ Ok($st::$tuple_variant_name($crate::util::ser::Readable::read(reader)?))
+ }),*
+ _ => {
+ Err($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)),* $(,)*)*) => {
+ $crate::_impl_writeable_tlv_based_enum_common!($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 = || {
+ $crate::_init_and_read_tlv_fields!(reader, {
+ $(($type, $field, $fieldty)),*
+ });
+ Ok(Some($st::$variant_name {
+ $(
+ $field: $crate::_init_tlv_based_struct_field!($field, $fieldty)
+ ),*
+ }))
+ };
+ f()
+ }),*
+ $($($tuple_variant_id => {
+ Ok(Some($st::$tuple_variant_name(Readable::read(reader)?)))
+ }),*)*
+ _ if id % 2 == 1 => Ok(None),
+ _ => Err($crate::ln::msgs::DecodeError::UnknownRequiredFeature),
+ }
+ }
+ }
+ }
+}
+
+#[cfg(test)]
+mod tests {
+ 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
+ // work with so they're baked into the decoder. Thus, we have a few additional tests below
+ fn tlv_reader(s: &[u8]) -> Result<(u64, u32, Option<u32>), DecodeError> {
+ let mut s = Cursor::new(s);
+ let mut a: u64 = 0;
+ let mut b: u32 = 0;
+ let mut c: Option<u32> = None;
+ decode_tlv_stream!(&mut s, {(2, a, required), (3, b, required), (4, c, option)});
+ Ok((a, b, c))
+ }
+
+ #[test]
+ fn tlv_v_short_read() {
+ // We only expect a u32 for type 3 (which we are given), but the L says its 8 bytes.
+ if let Err(DecodeError::ShortRead) = tlv_reader(&::hex::decode(
+ concat!("0100", "0208deadbeef1badbeef", "0308deadbeef")
+ ).unwrap()[..]) {
+ } else { panic!(); }
+ }
+
+ #[test]
+ fn tlv_types_out_of_order() {
+ if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
+ concat!("0100", "0304deadbeef", "0208deadbeef1badbeef")
+ ).unwrap()[..]) {
+ } else { panic!(); }
+ // ...even if its some field we don't understand
+ if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
+ concat!("0208deadbeef1badbeef", "0100", "0304deadbeef")
+ ).unwrap()[..]) {
+ } else { panic!(); }
+ }
+
+ #[test]
+ fn tlv_req_type_missing_or_extra() {
+ // It's also bad if they included even fields we don't understand
+ if let Err(DecodeError::UnknownRequiredFeature) = tlv_reader(&::hex::decode(
+ concat!("0100", "0208deadbeef1badbeef", "0304deadbeef", "0600")
+ ).unwrap()[..]) {
+ } else { panic!(); }
+ // ... or if they're missing fields we need
+ if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
+ concat!("0100", "0208deadbeef1badbeef")
+ ).unwrap()[..]) {
+ } else { panic!(); }
+ // ... even if that field is even
+ if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
+ concat!("0304deadbeef", "0500")
+ ).unwrap()[..]) {
+ } else { panic!(); }
+ }
+
+ #[test]
+ fn tlv_simple_good_cases() {
+ assert_eq!(tlv_reader(&::hex::decode(
+ concat!("0208deadbeef1badbeef", "03041bad1dea")
+ ).unwrap()[..]).unwrap(),
+ (0xdeadbeef1badbeef, 0x1bad1dea, None));
+ assert_eq!(tlv_reader(&::hex::decode(
+ concat!("0208deadbeef1badbeef", "03041bad1dea", "040401020304")
+ ).unwrap()[..]).unwrap(),
+ (0xdeadbeef1badbeef, 0x1bad1dea, Some(0x01020304)));
+ }
+
+ #[derive(Debug, PartialEq)]
+ struct TestUpgradable {
+ a: u32,
+ b: u32,
+ c: Option<u32>,
+ }
+
+ fn upgradable_tlv_reader(s: &[u8]) -> Result<Option<TestUpgradable>, DecodeError> {
+ let mut s = Cursor::new(s);
+ let mut a = 0;
+ let mut b = 0;
+ let mut c: Option<u32> = None;
+ decode_tlv_stream!(&mut s, {(2, a, upgradable_required), (3, b, upgradable_required), (4, c, upgradable_option)});
+ Ok(Some(TestUpgradable { a, b, c, }))
+ }
+
+ #[test]
+ fn upgradable_tlv_simple_good_cases() {
+ assert_eq!(upgradable_tlv_reader(&::hex::decode(
+ concat!("0204deadbeef", "03041bad1dea", "0404deadbeef")
+ ).unwrap()[..]).unwrap(),
+ Some(TestUpgradable { a: 0xdeadbeef, b: 0x1bad1dea, c: Some(0xdeadbeef) }));
+
+ assert_eq!(upgradable_tlv_reader(&::hex::decode(
+ concat!("0204deadbeef", "03041bad1dea")
+ ).unwrap()[..]).unwrap(),
+ Some(TestUpgradable { a: 0xdeadbeef, b: 0x1bad1dea, c: None}));
+ }
+
+ #[test]
+ fn missing_required_upgradable() {
+ if let Err(DecodeError::InvalidValue) = upgradable_tlv_reader(&::hex::decode(
+ concat!("0100", "0204deadbeef")
+ ).unwrap()[..]) {
+ } else { panic!(); }
+ if let Err(DecodeError::InvalidValue) = upgradable_tlv_reader(&::hex::decode(
+ concat!("0100", "03041bad1dea")
+ ).unwrap()[..]) {
+ } else { panic!(); }
+ }
+
+ // BOLT TLV test cases
+ 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<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_stream!(&mut s, {(1, tlv1, option), (2, tlv2, option), (3, tlv3, option), (254, tlv4, option)});
+ Ok((tlv1, tlv2, tlv3, tlv4))
+ }
+
+ #[test]
+ fn bolt_tlv_bogus_stream() {
+ macro_rules! do_test {
+ ($stream: expr, $reason: ident) => {
+ if let Err(DecodeError::$reason) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
+ } else { panic!(); }
+ }
+ }
+
+ // TLVs from the BOLT test cases which should not decode as either n1 or n2
+ do_test!(concat!("fd01"), ShortRead);
+ do_test!(concat!("fd0001", "00"), InvalidValue);
+ do_test!(concat!("fd0101"), ShortRead);
+ do_test!(concat!("0f", "fd"), ShortRead);
+ do_test!(concat!("0f", "fd26"), ShortRead);
+ do_test!(concat!("0f", "fd2602"), ShortRead);
+ do_test!(concat!("0f", "fd0001", "00"), InvalidValue);
+ do_test!(concat!("0f", "fd0201", "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"), ShortRead);
+
+ do_test!(concat!("12", "00"), UnknownRequiredFeature);
+ do_test!(concat!("fd0102", "00"), UnknownRequiredFeature);
+ do_test!(concat!("fe01000002", "00"), UnknownRequiredFeature);
+ do_test!(concat!("ff0100000000000002", "00"), UnknownRequiredFeature);
+ }
+
+ #[test]
+ fn bolt_tlv_bogus_n1_stream() {
+ macro_rules! do_test {
+ ($stream: expr, $reason: ident) => {
+ if let Err(DecodeError::$reason) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
+ } else { panic!(); }
+ }
+ }
+
+ // TLVs from the BOLT test cases which should not decode as n1
+ do_test!(concat!("01", "09", "ffffffffffffffffff"), InvalidValue);
+ do_test!(concat!("01", "01", "00"), InvalidValue);
+ do_test!(concat!("01", "02", "0001"), InvalidValue);
+ do_test!(concat!("01", "03", "000100"), InvalidValue);
+ do_test!(concat!("01", "04", "00010000"), InvalidValue);
+ do_test!(concat!("01", "05", "0001000000"), InvalidValue);
+ do_test!(concat!("01", "06", "000100000000"), InvalidValue);
+ do_test!(concat!("01", "07", "00010000000000"), InvalidValue);
+ do_test!(concat!("01", "08", "0001000000000000"), InvalidValue);
+ do_test!(concat!("02", "07", "01010101010101"), ShortRead);
+ do_test!(concat!("02", "09", "010101010101010101"), InvalidValue);
+ do_test!(concat!("03", "21", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb"), ShortRead);
+ do_test!(concat!("03", "29", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb0000000000000001"), ShortRead);
+ do_test!(concat!("03", "30", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb000000000000000100000000000001"), ShortRead);
+ do_test!(concat!("03", "31", "043da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb00000000000000010000000000000002"), InvalidValue);
+ do_test!(concat!("03", "32", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb0000000000000001000000000000000001"), InvalidValue);
+ do_test!(concat!("fd00fe", "00"), ShortRead);
+ do_test!(concat!("fd00fe", "01", "01"), ShortRead);
+ do_test!(concat!("fd00fe", "03", "010101"), InvalidValue);
+ do_test!(concat!("00", "00"), UnknownRequiredFeature);
+
+ do_test!(concat!("02", "08", "0000000000000226", "01", "01", "2a"), InvalidValue);
+ do_test!(concat!("02", "08", "0000000000000231", "02", "08", "0000000000000451"), InvalidValue);
+ do_test!(concat!("1f", "00", "0f", "01", "2a"), InvalidValue);
+ do_test!(concat!("1f", "00", "1f", "01", "2a"), InvalidValue);
+
+ // The last BOLT test modified to not require creating a new decoder for one trivial test.
+ do_test!(concat!("ffffffffffffffffff", "00", "01", "00"), InvalidValue);
+ }
+
+ #[test]
+ fn bolt_tlv_valid_n1_stream() {
+ macro_rules! do_test {
+ ($stream: expr, $tlv1: expr, $tlv2: expr, $tlv3: expr, $tlv4: expr) => {
+ if let Ok((tlv1, tlv2, tlv3, tlv4)) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
+ assert_eq!(tlv1.map(|v| v.0), $tlv1);
+ assert_eq!(tlv2, $tlv2);
+ assert_eq!(tlv3, $tlv3);
+ assert_eq!(tlv4, $tlv4);
+ } else { panic!(); }
+ }
+ }
+
+ do_test!(concat!(""), None, None, None, None);
+ do_test!(concat!("21", "00"), None, None, None, None);
+ do_test!(concat!("fd0201", "00"), None, None, None, None);
+ do_test!(concat!("fd00fd", "00"), None, None, None, None);
+ do_test!(concat!("fd00ff", "00"), None, None, None, None);
+ do_test!(concat!("fe02000001", "00"), None, None, None, None);
+ do_test!(concat!("ff0200000000000001", "00"), None, None, None, None);
+
+ do_test!(concat!("01", "00"), Some(0), None, None, None);
+ do_test!(concat!("01", "01", "01"), Some(1), None, None, None);
+ do_test!(concat!("01", "02", "0100"), Some(256), None, None, None);
+ do_test!(concat!("01", "03", "010000"), Some(65536), None, None, None);
+ do_test!(concat!("01", "04", "01000000"), Some(16777216), None, None, None);
+ do_test!(concat!("01", "05", "0100000000"), Some(4294967296), None, None, None);
+ do_test!(concat!("01", "06", "010000000000"), Some(1099511627776), None, None, None);
+ do_test!(concat!("01", "07", "01000000000000"), Some(281474976710656), None, None, None);
+ do_test!(concat!("01", "08", "0100000000000000"), Some(72057594037927936), None, None, None);
+ do_test!(concat!("02", "08", "0000000000000226"), None, Some((0 << 30) | (0 << 5) | (550 << 0)), None, None);
+ do_test!(concat!("03", "31", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb00000000000000010000000000000002"),
+ None, None, Some((
+ PublicKey::from_slice(&::hex::decode("023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb").unwrap()[..]).unwrap(), 1, 2)),
+ None);
+ do_test!(concat!("fd00fe", "02", "0226"), None, None, None, Some(550));
+ }
+
+ 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, required), (42, None::<u64>, option)});
+ assert_eq!(stream.0, ::hex::decode("03010101").unwrap());
+
+ stream.0.clear();
+ _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, {(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, 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(())
+ }
+
+ #[test]
+ fn simple_test_tlv_write() {
+ do_simple_test_tlv_write().unwrap();
+ }
+}