From c326061108d12f58fde5c4fb7f214fb308275f72 Mon Sep 17 00:00:00 2001 From: Matt Corallo Date: Sun, 2 Feb 2020 20:44:54 -0500 Subject: [PATCH] Add macros for building TLV (de)serializers. There's quite a bit of machinery included here, but it neatly avoids any dynamic allocation during TLV deserialization, and the calling side looks nice and simple. The macro-generated code is pretty nice, though has some redundant if statements (I haven't checked if they get optimized out yet, but I can't imagine they don't). --- lightning/src/util/ser_macros.rs | 327 +++++++++++++++++++++++++++++++ 1 file changed, 327 insertions(+) diff --git a/lightning/src/util/ser_macros.rs b/lightning/src/util/ser_macros.rs index 48e87b3bc..766d4ee2d 100644 --- a/lightning/src/util/ser_macros.rs +++ b/lightning/src/util/ser_macros.rs @@ -1,3 +1,109 @@ +macro_rules! encode_tlv { + ($stream: expr, {$(($type: expr, $field: expr)),*}) => { { + use util::ser::{BigSize, LengthCalculatingWriter}; + $( + BigSize($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)?; + )* + } } +} + +macro_rules! encode_varint_length_prefixed_tlv { + ($stream: expr, {$(($type: expr, $field: expr)),*}) => { { + use util::ser::{BigSize, LengthCalculatingWriter}; + let mut len = LengthCalculatingWriter(0); + { + $( + BigSize($type).write(&mut len)?; + let mut field_len = LengthCalculatingWriter(0); + $field.write(&mut field_len)?; + BigSize(field_len.0 as u64).write(&mut len)?; + len.0 += field_len.0; + )* + } + + BigSize(len.0 as u64).write($stream)?; + encode_tlv!($stream, { + $(($type, $field)),* + }); + } } +} + +macro_rules! decode_tlv { + ($stream: expr, {$(($reqtype: expr, $reqfield: ident)),*}, {$(($type: expr, $field: ident)),*}) => { { + use ln::msgs::DecodeError; + let mut last_seen_type: Option = None; + 'tlv_read: loop { + use util::ser; + + // First decode the type of this TLV: + let typ: ser::BigSize = { + // We track whether any bytes were read during the consensus_decode call to + // determine whether we should break or return ShortRead if we get an + // UnexpectedEof. This should in every case be largely cosmetic, but its nice to + // pass the TLV test vectors exactly, which requre this distinction. + let mut tracking_reader = ser::ReadTrackingReader::new($stream); + match ser::Readable::read(&mut tracking_reader) { + Err(DecodeError::ShortRead) => { + if !tracking_reader.have_read { + break 'tlv_read + } else { + Err(DecodeError::ShortRead)? + } + }, + Err(e) => Err(e)?, + Ok(t) => t, + } + }; + + // Types must be unique and monotonically increasing: + match last_seen_type { + Some(t) if typ.0 <= t => { + 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 > $reqtype { + Err(DecodeError::InvalidValue)? + })* + last_seen_type = Some(typ.0); + + // Finally, read the length and value itself: + let length: ser::BigSize = Readable::read($stream)?; + let mut s = ser::FixedLengthReader::new($stream, length.0); + match typ.0 { + $($reqtype => { + $reqfield = ser::Readable::read(&mut s)?; + if s.bytes_remain() { + s.eat_remaining()?; // Return ShortRead if there's actually not enough bytes + 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)? + } + },)* + 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() < $reqtype { + Err(DecodeError::InvalidValue)? + })* + } } +} + macro_rules! impl_writeable { ($st:ident, $len: expr, {$($field:ident),*}) => { impl ::util::ser::Writeable for $st { @@ -40,3 +146,224 @@ macro_rules! impl_writeable_len_match { } } } + +#[cfg(test)] +mod tests { + use std::io::{Cursor, Read}; + use ln::msgs::DecodeError; + use util::ser::{Readable, Writeable, HighZeroBytesDroppedVarInt, VecWriter}; + use 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), DecodeError> { + let mut s = Cursor::new(s); + let mut a: u64 = 0; + let mut b: u32 = 0; + let mut c: Option = None; + decode_tlv!(&mut s, {(2, a), (3, b)}, {(4, c)}); + 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))); + } + + impl Readable 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>, Option, Option<(PublicKey, u64, u64)>, Option), DecodeError> { + let mut s = Cursor::new(s); + let mut tlv1: Option> = None; + let mut tlv2: Option = None; + let mut tlv3: Option<(PublicKey, u64, u64)> = None; + let mut tlv4: Option = None; + decode_tlv!(&mut s, {}, {(1, tlv1), (2, tlv2), (3, tlv3), (254, tlv4)}); + 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<(), ::std::io::Error> { + let mut stream = VecWriter(Vec::new()); + + stream.0.clear(); + encode_varint_length_prefixed_tlv!(&mut stream, { (1, 1u8) }); + assert_eq!(stream.0, ::hex::decode("03010101").unwrap()); + + stream.0.clear(); + encode_varint_length_prefixed_tlv!(&mut stream, { (4, 0xabcdu16) }); + assert_eq!(stream.0, ::hex::decode("040402abcd").unwrap()); + + stream.0.clear(); + encode_varint_length_prefixed_tlv!(&mut stream, { (0xff, 0xabcdu16) }); + assert_eq!(stream.0, ::hex::decode("06fd00ff02abcd").unwrap()); + + stream.0.clear(); + encode_varint_length_prefixed_tlv!(&mut stream, { (0, 1u64), (0xff, HighZeroBytesDroppedVarInt(0u64)) }); + assert_eq!(stream.0, ::hex::decode("0e00080000000000000001fd00ff00").unwrap()); + + Ok(()) + } + + #[test] + fn simple_test_tlv_write() { + do_simple_test_tlv_write().unwrap(); + } +} -- 2.39.5