_ Git - rust-lightning/blob - lightning/src/util/ser_macros.rs

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 //! Some macros that implement [`Readable`]/[`Writeable`] traits for lightning messages.
  11 //! They also handle serialization and deserialization of TLVs.
  12 //!
  13 //! [`Readable`]: crate::util::ser::Readable
  14 //! [`Writeable`]: crate::util::ser::Writeable
  15
  16 /// Implements serialization for a single TLV record.
  17 /// This is exported for use by other exported macros, do not use directly.
  18 #[doc(hidden)]
  19 #[macro_export]
  20 macro_rules! _encode_tlv {
  21         ($stream: expr, $type: expr, $field: expr, (default_value, $default: expr)) => {
  22                 $crate::_encode_tlv!($stream, $type, $field, required)
  23         };
  24         ($stream: expr, $type: expr, $field: expr, (static_value, $value: expr)) => {
  25                 let _ = &$field; // Ensure we "use" the $field
  26         };
  27         ($stream: expr, $type: expr, $field: expr, required) => {
  28                 BigSize($type).write($stream)?;
  29                 BigSize($field.serialized_length() as u64).write($stream)?;
  30                 $field.write($stream)?;
  31         };
  32         ($stream: expr, $type: expr, $field: expr, vec_type) => {
  33                 $crate::_encode_tlv!($stream, $type, $crate::util::ser::WithoutLength(&$field), required);
  34         };
  35         ($stream: expr, $optional_type: expr, $optional_field: expr, option) => {
  36                 if let Some(ref field) = $optional_field {
  37                         BigSize($optional_type).write($stream)?;
  38                         BigSize(field.serialized_length() as u64).write($stream)?;
  39                         field.write($stream)?;
  40                 }
  41         };
  42         ($stream: expr, $type: expr, $field: expr, upgradable_required) => {
  43                 $crate::_encode_tlv!($stream, $type, $field, required);
  44         };
  45         ($stream: expr, $type: expr, $field: expr, upgradable_option) => {
  46                 $crate::_encode_tlv!($stream, $type, $field, option);
  47         };
  48         ($stream: expr, $type: expr, $field: expr, (option, encoding: ($fieldty: ty, $encoding: ident))) => {
  49                 $crate::_encode_tlv!($stream, $type, $field.map(|f| $encoding(f)), option);
  50         };
  51         ($stream: expr, $type: expr, $field: expr, (option, encoding: $fieldty: ty)) => {
  52                 $crate::_encode_tlv!($stream, $type, $field, option);
  53         };
  54 }
  55
  56 /// Panics if the last seen TLV type is not numerically less than the TLV type currently being checked.
  57 /// This is exported for use by other exported macros, do not use directly.
  58 #[doc(hidden)]
  59 #[macro_export]
  60 macro_rules! _check_encoded_tlv_order {
  61         ($last_type: expr, $type: expr, (static_value, $value: expr)) => { };
  62         ($last_type: expr, $type: expr, $fieldty: tt) => {
  63                 if let Some(t) = $last_type {
  64                         #[allow(unused_comparisons)] // Note that $type may be 0 making the following comparison always false
  65                         (debug_assert!(t < $type))
  66                 }
  67                 $last_type = Some($type);
  68         };
  69 }
  70
  71 /// Implements the TLVs serialization part in a [`Writeable`] implementation of a struct.
  72 ///
  73 /// This should be called inside a method which returns `Result<_, `[`io::Error`]`>`, such as
  74 /// [`Writeable::write`]. It will only return an `Err` if the stream `Err`s or [`Writeable::write`]
  75 /// on one of the fields `Err`s.
  76 ///
  77 /// `$stream` must be a `&mut `[`Writer`] which will receive the bytes for each TLV in the stream.
  78 ///
  79 /// Fields MUST be sorted in `$type`-order.
  80 ///
  81 /// Note that the lightning TLV requirements require that a single type not appear more than once,
  82 /// that TLVs are sorted in type-ascending order, and that any even types be understood by the
  83 /// decoder.
  84 ///
  85 /// Any `option` fields which have a value of `None` will not be serialized at all.
  86 ///
  87 /// For example,
  88 /// ```
  89 /// # use lightning::encode_tlv_stream;
  90 /// # fn write<W: lightning::util::ser::Writer> (stream: &mut W) -> Result<(), lightning::io::Error> {
  91 /// let mut required_value = 0u64;
  92 /// let mut optional_value: Option<u64> = None;
  93 /// encode_tlv_stream!(stream, {
  94 ///     (0, required_value, required),
  95 ///     (1, Some(42u64), option),
  96 ///     (2, optional_value, option),
  97 /// });
  98 /// // At this point `required_value` has been written as a TLV of type 0, `42u64` has been written
  99 /// // as a TLV of type 1 (indicating the reader may ignore it if it is not understood), and *no*
 100 /// // TLV is written with type 2.
 101 /// # Ok(())
 102 /// # }
 103 /// ```
 104 ///
 105 /// [`Writeable`]: crate::util::ser::Writeable
 106 /// [`io::Error`]: crate::io::Error
 107 /// [`Writeable::write`]: crate::util::ser::Writeable::write
 108 /// [`Writer`]: crate::util::ser::Writer
 109 #[macro_export]
 110 macro_rules! encode_tlv_stream {
 111         ($stream: expr, {$(($type: expr, $field: expr, $fieldty: tt)),* $(,)*}) => { {
 112                 #[allow(unused_imports)]
 113                 use $crate::{
 114                         ln::msgs::DecodeError,
 115                         util::ser,
 116                         util::ser::BigSize,
 117                         util::ser::Writeable,
 118                 };
 119
 120                 $(
 121                         $crate::_encode_tlv!($stream, $type, $field, $fieldty);
 122                 )*
 123
 124                 #[allow(unused_mut, unused_variables, unused_assignments)]
 125                 #[cfg(debug_assertions)]
 126                 {
 127                         let mut last_seen: Option<u64> = None;
 128                         $(
 129                                 $crate::_check_encoded_tlv_order!(last_seen, $type, $fieldty);
 130                         )*
 131                 }
 132         } }
 133 }
 134
 135 /// Adds the length of the serialized field to a [`LengthCalculatingWriter`].
 136 /// This is exported for use by other exported macros, do not use directly.
 137 ///
 138 /// [`LengthCalculatingWriter`]: crate::util::ser::LengthCalculatingWriter
 139 #[doc(hidden)]
 140 #[macro_export]
 141 macro_rules! _get_varint_length_prefixed_tlv_length {
 142         ($len: expr, $type: expr, $field: expr, (default_value, $default: expr)) => {
 143                 $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $field, required)
 144         };
 145         ($len: expr, $type: expr, $field: expr, (static_value, $value: expr)) => {
 146         };
 147         ($len: expr, $type: expr, $field: expr, required) => {
 148                 BigSize($type).write(&mut $len).expect("No in-memory data may fail to serialize");
 149                 let field_len = $field.serialized_length();
 150                 BigSize(field_len as u64).write(&mut $len).expect("No in-memory data may fail to serialize");
 151                 $len.0 += field_len;
 152         };
 153         ($len: expr, $type: expr, $field: expr, vec_type) => {
 154                 $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $crate::util::ser::WithoutLength(&$field), required);
 155         };
 156         ($len: expr, $optional_type: expr, $optional_field: expr, option) => {
 157                 if let Some(ref field) = $optional_field {
 158                         BigSize($optional_type).write(&mut $len).expect("No in-memory data may fail to serialize");
 159                         let field_len = field.serialized_length();
 160                         BigSize(field_len as u64).write(&mut $len).expect("No in-memory data may fail to serialize");
 161                         $len.0 += field_len;
 162                 }
 163         };
 164         ($len: expr, $type: expr, $field: expr, upgradable_required) => {
 165                 $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $field, required);
 166         };
 167         ($len: expr, $type: expr, $field: expr, upgradable_option) => {
 168                 $crate::_get_varint_length_prefixed_tlv_length!($len, $type, $field, option);
 169         };
 170 }
 171
 172 /// See the documentation of [`write_tlv_fields`].
 173 /// This is exported for use by other exported macros, do not use directly.
 174 #[doc(hidden)]
 175 #[macro_export]
 176 macro_rules! _encode_varint_length_prefixed_tlv {
 177         ($stream: expr, {$(($type: expr, $field: expr, $fieldty: tt)),*}) => { {
 178                 use $crate::util::ser::BigSize;
 179                 let len = {
 180                         #[allow(unused_mut)]
 181                         let mut len = $crate::util::ser::LengthCalculatingWriter(0);
 182                         $(
 183                                 $crate::_get_varint_length_prefixed_tlv_length!(len, $type, $field, $fieldty);
 184                         )*
 185                         len.0
 186                 };
 187                 BigSize(len as u64).write($stream)?;
 188                 $crate::encode_tlv_stream!($stream, { $(($type, $field, $fieldty)),* });
 189         } }
 190 }
 191
 192 /// Errors if there are missing required TLV types between the last seen type and the type currently being processed.
 193 /// This is exported for use by other exported macros, do not use directly.
 194 #[doc(hidden)]
 195 #[macro_export]
 196 macro_rules! _check_decoded_tlv_order {
 197         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (default_value, $default: expr)) => {{
 198                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always false
 199                 let invalid_order = ($last_seen_type.is_none() || $last_seen_type.unwrap() < $type) && $typ.0 > $type;
 200                 if invalid_order {
 201                         $field = $default.into();
 202                 }
 203         }};
 204         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (static_value, $value: expr)) => {
 205         };
 206         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, required) => {{
 207                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always false
 208                 let invalid_order = ($last_seen_type.is_none() || $last_seen_type.unwrap() < $type) && $typ.0 > $type;
 209                 if invalid_order {
 210                         return Err(DecodeError::InvalidValue);
 211                 }
 212         }};
 213         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, option) => {{
 214                 // no-op
 215         }};
 216         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, vec_type) => {{
 217                 // no-op
 218         }};
 219         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, upgradable_required) => {{
 220                 // no-op
 221         }};
 222         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, upgradable_option) => {{
 223                 // no-op
 224         }};
 225         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {{
 226                 // no-op
 227         }};
 228         ($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (option, encoding: $encoding: tt)) => {{
 229                 // no-op
 230         }};
 231 }
 232
 233 /// Errors if there are missing required TLV types after the last seen type.
 234 /// This is exported for use by other exported macros, do not use directly.
 235 #[doc(hidden)]
 236 #[macro_export]
 237 macro_rules! _check_missing_tlv {
 238         ($last_seen_type: expr, $type: expr, $field: ident, (default_value, $default: expr)) => {{
 239                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always false
 240                 let missing_req_type = $last_seen_type.is_none() || $last_seen_type.unwrap() < $type;
 241                 if missing_req_type {
 242                         $field = $default.into();
 243                 }
 244         }};
 245         ($last_seen_type: expr, $type: expr, $field: expr, (static_value, $value: expr)) => {
 246                 $field = $value;
 247         };
 248         ($last_seen_type: expr, $type: expr, $field: ident, required) => {{
 249                 #[allow(unused_comparisons)] // Note that $type may be 0 making the second comparison always false
 250                 let missing_req_type = $last_seen_type.is_none() || $last_seen_type.unwrap() < $type;
 251                 if missing_req_type {
 252                         return Err(DecodeError::InvalidValue);
 253                 }
 254         }};
 255         ($last_seen_type: expr, $type: expr, $field: ident, vec_type) => {{
 256                 // no-op
 257         }};
 258         ($last_seen_type: expr, $type: expr, $field: ident, option) => {{
 259                 // no-op
 260         }};
 261         ($last_seen_type: expr, $type: expr, $field: ident, upgradable_required) => {{
 262                 // no-op
 263         }};
 264         ($last_seen_type: expr, $type: expr, $field: ident, upgradable_option) => {{
 265                 // no-op
 266         }};
 267         ($last_seen_type: expr, $type: expr, $field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {{
 268                 // no-op
 269         }};
 270         ($last_seen_type: expr, $type: expr, $field: ident, (option, encoding: $encoding: tt)) => {{
 271                 // no-op
 272         }};
 273 }
 274
 275 /// Implements deserialization for a single TLV record.
 276 /// This is exported for use by other exported macros, do not use directly.
 277 #[doc(hidden)]
 278 #[macro_export]
 279 macro_rules! _decode_tlv {
 280         ($reader: expr, $field: ident, (default_value, $default: expr)) => {{
 281                 $crate::_decode_tlv!($reader, $field, required)
 282         }};
 283         ($reader: expr, $field: ident, (static_value, $value: expr)) => {{
 284         }};
 285         ($reader: expr, $field: ident, required) => {{
 286                 $field = $crate::util::ser::Readable::read(&mut $reader)?;
 287         }};
 288         ($reader: expr, $field: ident, vec_type) => {{
 289                 let f: $crate::util::ser::WithoutLength<Vec<_>> = $crate::util::ser::Readable::read(&mut $reader)?;
 290                 $field = Some(f.0);
 291         }};
 292         ($reader: expr, $field: ident, option) => {{
 293                 $field = Some($crate::util::ser::Readable::read(&mut $reader)?);
 294         }};
 295         ($reader: expr, $field: ident, upgradable_required) => {{
 296                 $field = $crate::util::ser::MaybeReadable::read(&mut $reader)?;
 297         }};
 298         ($reader: expr, $field: ident, upgradable_option) => {{
 299                 $field = $crate::util::ser::MaybeReadable::read(&mut $reader)?;
 300         }};
 301         ($reader: expr, $field: ident, (option: $trait: ident $(, $read_arg: expr)?)) => {{
 302                 $field = Some($trait::read(&mut $reader $(, $read_arg)*)?);
 303         }};
 304         ($reader: expr, $field: ident, (option, encoding: ($fieldty: ty, $encoding: ident, $encoder:ty))) => {{
 305                 $crate::_decode_tlv!($reader, $field, (option, encoding: ($fieldty, $encoding)));
 306         }};
 307         ($reader: expr, $field: ident, (option, encoding: ($fieldty: ty, $encoding: ident))) => {{
 308                 $field = {
 309                         let field: $encoding<$fieldty> = ser::Readable::read(&mut $reader)?;
 310                         Some(field.0)
 311                 };
 312         }};
 313         ($reader: expr, $field: ident, (option, encoding: $fieldty: ty)) => {{
 314                 $crate::_decode_tlv!($reader, $field, option);
 315         }};
 316 }
 317
 318 /// Checks if `$val` matches `$type`.
 319 /// This is exported for use by other exported macros, do not use directly.
 320 #[doc(hidden)]
 321 #[macro_export]
 322 macro_rules! _decode_tlv_stream_match_check {
 323         ($val: ident, $type: expr, (static_value, $value: expr)) => { false };
 324         ($val: ident, $type: expr, $fieldty: tt) => { $val == $type }
 325 }
 326
 327 /// Implements the TLVs deserialization part in a [`Readable`] implementation of a struct.
 328 ///
 329 /// This should be called inside a method which returns `Result<_, `[`DecodeError`]`>`, such as
 330 /// [`Readable::read`]. It will either return an `Err` or ensure all `required` fields have been
 331 /// read and optionally read `optional` fields.
 332 ///
 333 /// `$stream` must be a [`Read`] and will be fully consumed, reading until no more bytes remain
 334 /// (i.e. it returns [`DecodeError::ShortRead`]).
 335 ///
 336 /// Fields MUST be sorted in `$type`-order.
 337 ///
 338 /// Note that the lightning TLV requirements require that a single type not appear more than once,
 339 /// that TLVs are sorted in type-ascending order, and that any even types be understood by the
 340 /// decoder.
 341 ///
 342 /// For example,
 343 /// ```
 344 /// # use lightning::decode_tlv_stream;
 345 /// # fn read<R: lightning::io::Read> (stream: R) -> Result<(), lightning::ln::msgs::DecodeError> {
 346 /// let mut required_value = 0u64;
 347 /// let mut optional_value: Option<u64> = None;
 348 /// decode_tlv_stream!(stream, {
 349 ///     (0, required_value, required),
 350 ///     (2, optional_value, option),
 351 /// });
 352 /// // At this point, `required_value` has been overwritten with the TLV with type 0.
 353 /// // `optional_value` may have been overwritten, setting it to `Some` if a TLV with type 2 was
 354 /// // present.
 355 /// # Ok(())
 356 /// # }
 357 /// ```
 358 ///
 359 /// [`Readable`]: crate::util::ser::Readable
 360 /// [`DecodeError`]: crate::ln::msgs::DecodeError
 361 /// [`Readable::read`]: crate::util::ser::Readable::read
 362 /// [`Read`]: crate::io::Read
 363 /// [`DecodeError::ShortRead`]: crate::ln::msgs::DecodeError::ShortRead
 364 #[macro_export]
 365 macro_rules! decode_tlv_stream {
 366         ($stream: expr, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => {
 367                 let rewind = |_, _| { unreachable!() };
 368                 $crate::_decode_tlv_stream_range!($stream, .., rewind, {$(($type, $field, $fieldty)),*});
 369         }
 370 }
 371
 372 /// Similar to [`decode_tlv_stream`] with a custom TLV decoding capabilities.
 373 ///
 374 /// `$decode_custom_tlv` is a closure that may be optionally provided to handle custom message types.
 375 /// If it is provided, it will be called with the custom type and the [`FixedLengthReader`] containing
 376 /// the message contents. It should return `Ok(true)` if the custom message is successfully parsed,
 377 /// `Ok(false)` if the message type is unknown, and `Err(`[`DecodeError`]`)` if parsing fails.
 378 ///
 379 /// [`FixedLengthReader`]: crate::util::ser::FixedLengthReader
 380 /// [`DecodeError`]: crate::ln::msgs::DecodeError
 381 macro_rules! decode_tlv_stream_with_custom_tlv_decode {
 382         ($stream: expr, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 383          $(, $decode_custom_tlv: expr)?) => { {
 384                 let rewind = |_, _| { unreachable!() };
 385                 _decode_tlv_stream_range!(
 386                         $stream, .., rewind, {$(($type, $field, $fieldty)),*} $(, $decode_custom_tlv)?
 387                 );
 388         } }
 389 }
 390
 391 #[doc(hidden)]
 392 #[macro_export]
 393 macro_rules! _decode_tlv_stream_range {
 394         ($stream: expr, $range: expr, $rewind: ident, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 395          $(, $decode_custom_tlv: expr)?) => { {
 396                 use core::ops::RangeBounds;
 397                 use $crate::ln::msgs::DecodeError;
 398                 let mut last_seen_type: Option<u64> = None;
 399                 let mut stream_ref = $stream;
 400                 'tlv_read: loop {
 401                         use $crate::util::ser;
 402
 403                         // First decode the type of this TLV:
 404                         let typ: ser::BigSize = {
 405                                 // We track whether any bytes were read during the consensus_decode call to
 406                                 // determine whether we should break or return ShortRead if we get an
 407                                 // UnexpectedEof. This should in every case be largely cosmetic, but its nice to
 408                                 // pass the TLV test vectors exactly, which require this distinction.
 409                                 let mut tracking_reader = ser::ReadTrackingReader::new(&mut stream_ref);
 410                                 match <$crate::util::ser::BigSize as $crate::util::ser::Readable>::read(&mut tracking_reader) {
 411                                         Err(DecodeError::ShortRead) => {
 412                                                 if !tracking_reader.have_read {
 413                                                         break 'tlv_read;
 414                                                 } else {
 415                                                         return Err(DecodeError::ShortRead);
 416                                                 }
 417                                         },
 418                                         Err(e) => return Err(e),
 419                                         Ok(t) => if $range.contains(&t.0) { t } else {
 420                                                 drop(tracking_reader);
 421
 422                                                 // Assumes the type id is minimally encoded, which is enforced on read.
 423                                                 use $crate::util::ser::Writeable;
 424                                                 let bytes_read = t.serialized_length();
 425                                                 $rewind(stream_ref, bytes_read);
 426                                                 break 'tlv_read;
 427                                         },
 428                                 }
 429                         };
 430
 431                         // Types must be unique and monotonically increasing:
 432                         match last_seen_type {
 433                                 Some(t) if typ.0 <= t => {
 434                                         return Err(DecodeError::InvalidValue);
 435                                 },
 436                                 _ => {},
 437                         }
 438                         // As we read types, make sure we hit every required type between `last_seen_type` and `typ`:
 439                         $({
 440                                 $crate::_check_decoded_tlv_order!(last_seen_type, typ, $type, $field, $fieldty);
 441                         })*
 442                         last_seen_type = Some(typ.0);
 443
 444                         // Finally, read the length and value itself:
 445                         let length: ser::BigSize = $crate::util::ser::Readable::read(&mut stream_ref)?;
 446                         let mut s = ser::FixedLengthReader::new(&mut stream_ref, length.0);
 447                         match typ.0 {
 448                                 $(_t if $crate::_decode_tlv_stream_match_check!(_t, $type, $fieldty) => {
 449                                         $crate::_decode_tlv!(s, $field, $fieldty);
 450                                         if s.bytes_remain() {
 451                                                 s.eat_remaining()?; // Return ShortRead if there's actually not enough bytes
 452                                                 return Err(DecodeError::InvalidValue);
 453                                         }
 454                                 },)*
 455                                 t => {
 456                                         $(
 457                                                 if $decode_custom_tlv(t, &mut s)? {
 458                                                         // If a custom TLV was successfully read (i.e. decode_custom_tlv returns true),
 459                                                         // continue to the next TLV read.
 460                                                         s.eat_remaining()?;
 461                                                         continue 'tlv_read;
 462                                                 }
 463                                         )?
 464                                         if t % 2 == 0 {
 465                                                 return Err(DecodeError::UnknownRequiredFeature);
 466                                         }
 467                                 }
 468                         }
 469                         s.eat_remaining()?;
 470                 }
 471                 // Make sure we got to each required type after we've read every TLV:
 472                 $({
 473                         $crate::_check_missing_tlv!(last_seen_type, $type, $field, $fieldty);
 474                 })*
 475         } }
 476 }
 477
 478 /// Implements [`Readable`]/[`Writeable`] for a message struct that may include non-TLV and
 479 /// TLV-encoded parts.
 480 ///
 481 /// This is useful to implement a [`CustomMessageReader`].
 482 ///
 483 /// Currently `$fieldty` may only be `option`, i.e., `$tlvfield` is optional field.
 484 ///
 485 /// For example,
 486 /// ```
 487 /// # use lightning::impl_writeable_msg;
 488 /// struct MyCustomMessage {
 489 ///     pub field_1: u32,
 490 ///     pub field_2: bool,
 491 ///     pub field_3: String,
 492 ///     pub tlv_optional_integer: Option<u32>,
 493 /// }
 494 ///
 495 /// impl_writeable_msg!(MyCustomMessage, {
 496 ///     field_1,
 497 ///     field_2,
 498 ///     field_3
 499 /// }, {
 500 ///     (1, tlv_optional_integer, option),
 501 /// });
 502 /// ```
 503 ///
 504 /// [`Readable`]: crate::util::ser::Readable
 505 /// [`Writeable`]: crate::util::ser::Writeable
 506 /// [`CustomMessageReader`]: crate::ln::wire::CustomMessageReader
 507 #[macro_export]
 508 macro_rules! impl_writeable_msg {
 509         ($st:ident, {$($field:ident),* $(,)*}, {$(($type: expr, $tlvfield: ident, $fieldty: tt)),* $(,)*}) => {
 510                 impl $crate::util::ser::Writeable for $st {
 511                         fn write<W: $crate::util::ser::Writer>(&self, w: &mut W) -> Result<(), $crate::io::Error> {
 512                                 $( self.$field.write(w)?; )*
 513                                 $crate::encode_tlv_stream!(w, {$(($type, self.$tlvfield, $fieldty)),*});
 514                                 Ok(())
 515                         }
 516                 }
 517                 impl $crate::util::ser::Readable for $st {
 518                         fn read<R: $crate::io::Read>(r: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
 519                                 $(let $field = $crate::util::ser::Readable::read(r)?;)*
 520                                 $($crate::_init_tlv_field_var!($tlvfield, $fieldty);)*
 521                                 $crate::decode_tlv_stream!(r, {$(($type, $tlvfield, $fieldty)),*});
 522                                 Ok(Self {
 523                                         $($field),*,
 524                                         $($tlvfield),*
 525                                 })
 526                         }
 527                 }
 528         }
 529 }
 530
 531 macro_rules! impl_writeable {
 532         ($st:ident, {$($field:ident),*}) => {
 533                 impl $crate::util::ser::Writeable for $st {
 534                         fn write<W: $crate::util::ser::Writer>(&self, w: &mut W) -> Result<(), $crate::io::Error> {
 535                                 $( self.$field.write(w)?; )*
 536                                 Ok(())
 537                         }
 538
 539                         #[inline]
 540                         fn serialized_length(&self) -> usize {
 541                                 let mut len_calc = 0;
 542                                 $( len_calc += self.$field.serialized_length(); )*
 543                                 return len_calc;
 544                         }
 545                 }
 546
 547                 impl $crate::util::ser::Readable for $st {
 548                         fn read<R: $crate::io::Read>(r: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
 549                                 Ok(Self {
 550                                         $($field: $crate::util::ser::Readable::read(r)?),*
 551                                 })
 552                         }
 553                 }
 554         }
 555 }
 556
 557 /// Write out two bytes to indicate the version of an object.
 558 ///
 559 /// $this_version represents a unique version of a type. Incremented whenever the type's
 560 /// serialization format has changed or has a new interpretation. Used by a type's reader to
 561 /// determine how to interpret fields or if it can understand a serialized object.
 562 ///
 563 /// $min_version_that_can_read_this is the minimum reader version which can understand this
 564 /// serialized object. Previous versions will simply err with a [`DecodeError::UnknownVersion`].
 565 ///
 566 /// Updates to either `$this_version` or `$min_version_that_can_read_this` should be included in
 567 /// release notes.
 568 ///
 569 /// Both version fields can be specific to this type of object.
 570 ///
 571 /// [`DecodeError::UnknownVersion`]: crate::ln::msgs::DecodeError::UnknownVersion
 572 macro_rules! write_ver_prefix {
 573         ($stream: expr, $this_version: expr, $min_version_that_can_read_this: expr) => {
 574                 $stream.write_all(&[$this_version; 1])?;
 575                 $stream.write_all(&[$min_version_that_can_read_this; 1])?;
 576         }
 577 }
 578
 579 /// Writes out a suffix to an object as a length-prefixed TLV stream which contains potentially
 580 /// backwards-compatible, optional fields which old nodes can happily ignore.
 581 ///
 582 /// It is written out in TLV format and, as with all TLV fields, unknown even fields cause a
 583 /// [`DecodeError::UnknownRequiredFeature`] error, with unknown odd fields ignored.
 584 ///
 585 /// This is the preferred method of adding new fields that old nodes can ignore and still function
 586 /// correctly.
 587 ///
 588 /// [`DecodeError::UnknownRequiredFeature`]: crate::ln::msgs::DecodeError::UnknownRequiredFeature
 589 #[macro_export]
 590 macro_rules! write_tlv_fields {
 591         ($stream: expr, {$(($type: expr, $field: expr, $fieldty: tt)),* $(,)*}) => {
 592                 $crate::_encode_varint_length_prefixed_tlv!($stream, {$(($type, $field, $fieldty)),*})
 593         }
 594 }
 595
 596 /// Reads a prefix added by [`write_ver_prefix`], above. Takes the current version of the
 597 /// serialization logic for this object. This is compared against the
 598 /// `$min_version_that_can_read_this` added by [`write_ver_prefix`].
 599 macro_rules! read_ver_prefix {
 600         ($stream: expr, $this_version: expr) => { {
 601                 let ver: u8 = Readable::read($stream)?;
 602                 let min_ver: u8 = Readable::read($stream)?;
 603                 if min_ver > $this_version {
 604                         return Err(DecodeError::UnknownVersion);
 605                 }
 606                 ver
 607         } }
 608 }
 609
 610 /// Reads a suffix added by [`write_tlv_fields`].
 611 ///
 612 /// [`write_tlv_fields`]: crate::write_tlv_fields
 613 #[macro_export]
 614 macro_rules! read_tlv_fields {
 615         ($stream: expr, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => { {
 616                 let tlv_len: $crate::util::ser::BigSize = $crate::util::ser::Readable::read($stream)?;
 617                 let mut rd = $crate::util::ser::FixedLengthReader::new($stream, tlv_len.0);
 618                 $crate::decode_tlv_stream!(&mut rd, {$(($type, $field, $fieldty)),*});
 619                 rd.eat_remaining().map_err(|_| $crate::ln::msgs::DecodeError::ShortRead)?;
 620         } }
 621 }
 622
 623 /// Initializes the struct fields.
 624 ///
 625 /// This is exported for use by other exported macros, do not use directly.
 626 #[doc(hidden)]
 627 #[macro_export]
 628 macro_rules! _init_tlv_based_struct_field {
 629         ($field: ident, (default_value, $default: expr)) => {
 630                 $field.0.unwrap()
 631         };
 632         ($field: ident, (static_value, $value: expr)) => {
 633                 $field
 634         };
 635         ($field: ident, option) => {
 636                 $field
 637         };
 638         ($field: ident, upgradable_required) => {
 639                 if $field.is_none() { return Ok(None); } else { $field.unwrap() }
 640         };
 641         ($field: ident, upgradable_option) => {
 642                 $field
 643         };
 644         ($field: ident, required) => {
 645                 $field.0.unwrap()
 646         };
 647         ($field: ident, vec_type) => {
 648                 $field.unwrap()
 649         };
 650 }
 651
 652 /// Initializes the variable we are going to read the TLV into.
 653 ///
 654 /// This is exported for use by other exported macros, do not use directly.
 655 #[doc(hidden)]
 656 #[macro_export]
 657 macro_rules! _init_tlv_field_var {
 658         ($field: ident, (default_value, $default: expr)) => {
 659                 let mut $field = $crate::util::ser::OptionDeserWrapper(None);
 660         };
 661         ($field: ident, (static_value, $value: expr)) => {
 662                 let $field;
 663         };
 664         ($field: ident, required) => {
 665                 let mut $field = $crate::util::ser::OptionDeserWrapper(None);
 666         };
 667         ($field: ident, vec_type) => {
 668                 let mut $field = Some(Vec::new());
 669         };
 670         ($field: ident, option) => {
 671                 let mut $field = None;
 672         };
 673         ($field: ident, upgradable_required) => {
 674                 let mut $field = None;
 675         };
 676         ($field: ident, upgradable_option) => {
 677                 let mut $field = None;
 678         };
 679 }
 680
 681 /// Equivalent to running [`_init_tlv_field_var`] then [`read_tlv_fields`].
 682 ///
 683 /// This is exported for use by other exported macros, do not use directly.
 684 #[doc(hidden)]
 685 #[macro_export]
 686 macro_rules! _init_and_read_tlv_fields {
 687         ($reader: ident, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => {
 688                 $(
 689                         $crate::_init_tlv_field_var!($field, $fieldty);
 690                 )*
 691
 692                 $crate::read_tlv_fields!($reader, {
 693                         $(($type, $field, $fieldty)),*
 694                 });
 695         }
 696 }
 697
 698 /// Implements [`Readable`]/[`Writeable`] for a struct storing it as a set of TLVs
 699 /// If `$fieldty` is `required`, then `$field` is a required field that is not an [`Option`] nor a [`Vec`].
 700 /// If `$fieldty` is `(default_value, $default)`, then `$field` will be set to `$default` if not present.
 701 /// If `$fieldty` is `option`, then `$field` is optional field.
 702 /// If `$fieldty` is `vec_type`, then `$field` is a [`Vec`], which needs to have its individual elements serialized.
 703 ///
 704 /// For example,
 705 /// ```
 706 /// # use lightning::impl_writeable_tlv_based;
 707 /// struct LightningMessage {
 708 ///     tlv_integer: u32,
 709 ///     tlv_default_integer: u32,
 710 ///     tlv_optional_integer: Option<u32>,
 711 ///     tlv_vec_type_integer: Vec<u32>,
 712 /// }
 713 ///
 714 /// impl_writeable_tlv_based!(LightningMessage, {
 715 ///     (0, tlv_integer, required),
 716 ///     (1, tlv_default_integer, (default_value, 7)),
 717 ///     (2, tlv_optional_integer, option),
 718 ///     (3, tlv_vec_type_integer, vec_type),
 719 /// });
 720 /// ```
 721 ///
 722 /// [`Readable`]: crate::util::ser::Readable
 723 /// [`Writeable`]: crate::util::ser::Writeable
 724 #[macro_export]
 725 macro_rules! impl_writeable_tlv_based {
 726         ($st: ident, {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}) => {
 727                 impl $crate::util::ser::Writeable for $st {
 728                         fn write<W: $crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), $crate::io::Error> {
 729                                 $crate::write_tlv_fields!(writer, {
 730                                         $(($type, self.$field, $fieldty)),*
 731                                 });
 732                                 Ok(())
 733                         }
 734
 735                         #[inline]
 736                         fn serialized_length(&self) -> usize {
 737                                 use $crate::util::ser::BigSize;
 738                                 let len = {
 739                                         #[allow(unused_mut)]
 740                                         let mut len = $crate::util::ser::LengthCalculatingWriter(0);
 741                                         $(
 742                                                 $crate::_get_varint_length_prefixed_tlv_length!(len, $type, self.$field, $fieldty);
 743                                         )*
 744                                         len.0
 745                                 };
 746                                 let mut len_calc = $crate::util::ser::LengthCalculatingWriter(0);
 747                                 BigSize(len as u64).write(&mut len_calc).expect("No in-memory data may fail to serialize");
 748                                 len + len_calc.0
 749                         }
 750                 }
 751
 752                 impl $crate::util::ser::Readable for $st {
 753                         fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
 754                                 $crate::_init_and_read_tlv_fields!(reader, {
 755                                         $(($type, $field, $fieldty)),*
 756                                 });
 757                                 Ok(Self {
 758                                         $(
 759                                                 $field: $crate::_init_tlv_based_struct_field!($field, $fieldty)
 760                                         ),*
 761                                 })
 762                         }
 763                 }
 764         }
 765 }
 766
 767 /// Defines a struct for a TLV stream and a similar struct using references for non-primitive types,
 768 /// implementing [`Readable`] for the former and [`Writeable`] for the latter. Useful as an
 769 /// intermediary format when reading or writing a type encoded as a TLV stream. Note that each field
 770 /// representing a TLV record has its type wrapped with an [`Option`]. A tuple consisting of a type
 771 /// and a serialization wrapper may be given in place of a type when custom serialization is
 772 /// required.
 773 ///
 774 /// [`Readable`]: crate::util::ser::Readable
 775 /// [`Writeable`]: crate::util::ser::Writeable
 776 macro_rules! tlv_stream {
 777         ($name:ident, $nameref:ident, $range:expr, {
 778                 $(($type:expr, $field:ident : $fieldty:tt)),* $(,)*
 779         }) => {
 780                 #[derive(Debug)]
 781                 pub(super) struct $name {
 782                         $(
 783                                 pub(super) $field: Option<tlv_record_type!($fieldty)>,
 784                         )*
 785                 }
 786
 787                 #[cfg_attr(test, derive(PartialEq))]
 788                 #[derive(Debug)]
 789                 pub(super) struct $nameref<'a> {
 790                         $(
 791                                 pub(super) $field: Option<tlv_record_ref_type!($fieldty)>,
 792                         )*
 793                 }
 794
 795                 impl<'a> $crate::util::ser::Writeable for $nameref<'a> {
 796                         fn write<W: $crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), $crate::io::Error> {
 797                                 encode_tlv_stream!(writer, {
 798                                         $(($type, self.$field, (option, encoding: $fieldty))),*
 799                                 });
 800                                 Ok(())
 801                         }
 802                 }
 803
 804                 impl $crate::util::ser::SeekReadable for $name {
 805                         fn read<R: $crate::io::Read + $crate::io::Seek>(reader: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
 806                                 $(
 807                                         _init_tlv_field_var!($field, option);
 808                                 )*
 809                                 let rewind = |cursor: &mut R, offset: usize| {
 810                                         cursor.seek($crate::io::SeekFrom::Current(-(offset as i64))).expect("");
 811                                 };
 812                                 _decode_tlv_stream_range!(reader, $range, rewind, {
 813                                         $(($type, $field, (option, encoding: $fieldty))),*
 814                                 });
 815
 816                                 Ok(Self {
 817                                         $(
 818                                                 $field: $field
 819                                         ),*
 820                                 })
 821                         }
 822                 }
 823         }
 824 }
 825
 826 macro_rules! tlv_record_type {
 827         (($type:ty, $wrapper:ident)) => { $type };
 828         (($type:ty, $wrapper:ident, $encoder:ty)) => { $type };
 829         ($type:ty) => { $type };
 830 }
 831
 832 macro_rules! tlv_record_ref_type {
 833         (char) => { char };
 834         (u8) => { u8 };
 835         ((u16, $wrapper: ident)) => { u16 };
 836         ((u32, $wrapper: ident)) => { u32 };
 837         ((u64, $wrapper: ident)) => { u64 };
 838         (($type:ty, $wrapper:ident)) => { &'a $type };
 839         (($type:ty, $wrapper:ident, $encoder:ty)) => { $encoder };
 840         ($type:ty) => { &'a $type };
 841 }
 842
 843 macro_rules! _impl_writeable_tlv_based_enum_common {
 844         ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
 845                 {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 846         ),* $(,)*;
 847         $(($tuple_variant_id: expr, $tuple_variant_name: ident)),*  $(,)*) => {
 848                 impl $crate::util::ser::Writeable for $st {
 849                         fn write<W: $crate::util::ser::Writer>(&self, writer: &mut W) -> Result<(), $crate::io::Error> {
 850                                 match self {
 851                                         $($st::$variant_name { $(ref $field),* } => {
 852                                                 let id: u8 = $variant_id;
 853                                                 id.write(writer)?;
 854                                                 write_tlv_fields!(writer, {
 855                                                         $(($type, *$field, $fieldty)),*
 856                                                 });
 857                                         }),*
 858                                         $($st::$tuple_variant_name (ref field) => {
 859                                                 let id: u8 = $tuple_variant_id;
 860                                                 id.write(writer)?;
 861                                                 field.write(writer)?;
 862                                         }),*
 863                                 }
 864                                 Ok(())
 865                         }
 866                 }
 867         }
 868 }
 869
 870 /// Implement [`Readable`] and [`Writeable`] for an enum, with struct variants stored as TLVs and tuple
 871 /// variants stored directly.
 872 /// The format is, for example
 873 /// ```ignore
 874 /// impl_writeable_tlv_based_enum!(EnumName,
 875 ///   (0, StructVariantA) => {(0, required_variant_field, required), (1, optional_variant_field, option)},
 876 ///   (1, StructVariantB) => {(0, variant_field_a, required), (1, variant_field_b, required), (2, variant_vec_field, vec_type)};
 877 ///   (2, TupleVariantA), (3, TupleVariantB),
 878 /// );
 879 /// ```
 880 /// The type is written as a single byte, followed by any variant data.
 881 /// Attempts to read an unknown type byte result in [`DecodeError::UnknownRequiredFeature`].
 882 ///
 883 /// [`Readable`]: crate::util::ser::Readable
 884 /// [`Writeable`]: crate::util::ser::Writeable
 885 /// [`DecodeError::UnknownRequiredFeature`]: crate::ln::msgs::DecodeError::UnknownRequiredFeature
 886 #[macro_export]
 887 macro_rules! impl_writeable_tlv_based_enum {
 888         ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
 889                 {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 890         ),* $(,)*;
 891         $(($tuple_variant_id: expr, $tuple_variant_name: ident)),*  $(,)*) => {
 892                 _impl_writeable_tlv_based_enum_common!($st,
 893                         $(($variant_id, $variant_name) => {$(($type, $field, $fieldty)),*}),*;
 894                         $(($tuple_variant_id, $tuple_variant_name)),*);
 895
 896                 impl $crate::util::ser::Readable for $st {
 897                         fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Self, $crate::ln::msgs::DecodeError> {
 898                                 let id: u8 = $crate::util::ser::Readable::read(reader)?;
 899                                 match id {
 900                                         $($variant_id => {
 901                                                 // Because read_tlv_fields creates a labeled loop, we cannot call it twice
 902                                                 // in the same function body. Instead, we define a closure and call it.
 903                                                 let f = || {
 904                                                         _init_and_read_tlv_fields!(reader, {
 905                                                                 $(($type, $field, $fieldty)),*
 906                                                         });
 907                                                         Ok($st::$variant_name {
 908                                                                 $(
 909                                                                         $field: _init_tlv_based_struct_field!($field, $fieldty)
 910                                                                 ),*
 911                                                         })
 912                                                 };
 913                                                 f()
 914                                         }),*
 915                                         $($tuple_variant_id => {
 916                                                 Ok($st::$tuple_variant_name(Readable::read(reader)?))
 917                                         }),*
 918                                         _ => {
 919                                                 Err($crate::ln::msgs::DecodeError::UnknownRequiredFeature)
 920                                         },
 921                                 }
 922                         }
 923                 }
 924         }
 925 }
 926
 927 /// Implement [`MaybeReadable`] and [`Writeable`] for an enum, with struct variants stored as TLVs and
 928 /// tuple variants stored directly.
 929 ///
 930 /// This is largely identical to [`impl_writeable_tlv_based_enum`], except that odd variants will
 931 /// return `Ok(None)` instead of `Err(`[`DecodeError::UnknownRequiredFeature`]`)`. It should generally be preferred
 932 /// when [`MaybeReadable`] is practical instead of just [`Readable`] as it provides an upgrade path for
 933 /// new variants to be added which are simply ignored by existing clients.
 934 ///
 935 /// [`MaybeReadable`]: crate::util::ser::MaybeReadable
 936 /// [`Writeable`]: crate::util::ser::Writeable
 937 /// [`DecodeError::UnknownRequiredFeature`]: crate::ln::msgs::DecodeError::UnknownRequiredFeature
 938 /// [`Readable`]: crate::util::ser::Readable
 939 #[macro_export]
 940 macro_rules! impl_writeable_tlv_based_enum_upgradable {
 941         ($st: ident, $(($variant_id: expr, $variant_name: ident) =>
 942                 {$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
 943         ),* $(,)*
 944         $(;
 945         $(($tuple_variant_id: expr, $tuple_variant_name: ident)),*  $(,)*)*) => {
 946                 _impl_writeable_tlv_based_enum_common!($st,
 947                         $(($variant_id, $variant_name) => {$(($type, $field, $fieldty)),*}),*;
 948                         $($(($tuple_variant_id, $tuple_variant_name)),*)*);
 949
 950                 impl $crate::util::ser::MaybeReadable for $st {
 951                         fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Option<Self>, $crate::ln::msgs::DecodeError> {
 952                                 let id: u8 = $crate::util::ser::Readable::read(reader)?;
 953                                 match id {
 954                                         $($variant_id => {
 955                                                 // Because read_tlv_fields creates a labeled loop, we cannot call it twice
 956                                                 // in the same function body. Instead, we define a closure and call it.
 957                                                 let f = || {
 958                                                         _init_and_read_tlv_fields!(reader, {
 959                                                                 $(($type, $field, $fieldty)),*
 960                                                         });
 961                                                         Ok(Some($st::$variant_name {
 962                                                                 $(
 963                                                                         $field: _init_tlv_based_struct_field!($field, $fieldty)
 964                                                                 ),*
 965                                                         }))
 966                                                 };
 967                                                 f()
 968                                         }),*
 969                                         $($($tuple_variant_id => {
 970                                                 Ok(Some($st::$tuple_variant_name(Readable::read(reader)?)))
 971                                         }),*)*
 972                                         _ if id % 2 == 1 => Ok(None),
 973                                         _ => Err($crate::ln::msgs::DecodeError::UnknownRequiredFeature),
 974                                 }
 975                         }
 976                 }
 977         }
 978 }
 979
 980 #[cfg(test)]
 981 mod tests {
 982         use crate::io::{self, Cursor};
 983         use crate::prelude::*;
 984         use crate::ln::msgs::DecodeError;
 985         use crate::util::ser::{Writeable, HighZeroBytesDroppedBigSize, VecWriter};
 986         use bitcoin::secp256k1::PublicKey;
 987
 988         // The BOLT TLV test cases don't include any tests which use our "required-value" logic since
 989         // the encoding layer in the BOLTs has no such concept, though it makes our macros easier to
 990         // work with so they're baked into the decoder. Thus, we have a few additional tests below
 991         fn tlv_reader(s: &[u8]) -> Result<(u64, u32, Option<u32>), DecodeError> {
 992                 let mut s = Cursor::new(s);
 993                 let mut a: u64 = 0;
 994                 let mut b: u32 = 0;
 995                 let mut c: Option<u32> = None;
 996                 decode_tlv_stream!(&mut s, {(2, a, required), (3, b, required), (4, c, option)});
 997                 Ok((a, b, c))
 998         }
 999
1000         #[test]
1001         fn tlv_v_short_read() {
1002                 // We only expect a u32 for type 3 (which we are given), but the L says its 8 bytes.
1003                 if let Err(DecodeError::ShortRead) = tlv_reader(&::hex::decode(
1004                                 concat!("0100", "0208deadbeef1badbeef", "0308deadbeef")
1005                                 ).unwrap()[..]) {
1006                 } else { panic!(); }
1007         }
1008
1009         #[test]
1010         fn tlv_types_out_of_order() {
1011                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
1012                                 concat!("0100", "0304deadbeef", "0208deadbeef1badbeef")
1013                                 ).unwrap()[..]) {
1014                 } else { panic!(); }
1015                 // ...even if its some field we don't understand
1016                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
1017                                 concat!("0208deadbeef1badbeef", "0100", "0304deadbeef")
1018                                 ).unwrap()[..]) {
1019                 } else { panic!(); }
1020         }
1021
1022         #[test]
1023         fn tlv_req_type_missing_or_extra() {
1024                 // It's also bad if they included even fields we don't understand
1025                 if let Err(DecodeError::UnknownRequiredFeature) = tlv_reader(&::hex::decode(
1026                                 concat!("0100", "0208deadbeef1badbeef", "0304deadbeef", "0600")
1027                                 ).unwrap()[..]) {
1028                 } else { panic!(); }
1029                 // ... or if they're missing fields we need
1030                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
1031                                 concat!("0100", "0208deadbeef1badbeef")
1032                                 ).unwrap()[..]) {
1033                 } else { panic!(); }
1034                 // ... even if that field is even
1035                 if let Err(DecodeError::InvalidValue) = tlv_reader(&::hex::decode(
1036                                 concat!("0304deadbeef", "0500")
1037                                 ).unwrap()[..]) {
1038                 } else { panic!(); }
1039         }
1040
1041         #[test]
1042         fn tlv_simple_good_cases() {
1043                 assert_eq!(tlv_reader(&::hex::decode(
1044                                 concat!("0208deadbeef1badbeef", "03041bad1dea")
1045                                 ).unwrap()[..]).unwrap(),
1046                         (0xdeadbeef1badbeef, 0x1bad1dea, None));
1047                 assert_eq!(tlv_reader(&::hex::decode(
1048                                 concat!("0208deadbeef1badbeef", "03041bad1dea", "040401020304")
1049                                 ).unwrap()[..]).unwrap(),
1050                         (0xdeadbeef1badbeef, 0x1bad1dea, Some(0x01020304)));
1051         }
1052
1053         // BOLT TLV test cases
1054         fn tlv_reader_n1(s: &[u8]) -> Result<(Option<HighZeroBytesDroppedBigSize<u64>>, Option<u64>, Option<(PublicKey, u64, u64)>, Option<u16>), DecodeError> {
1055                 let mut s = Cursor::new(s);
1056                 let mut tlv1: Option<HighZeroBytesDroppedBigSize<u64>> = None;
1057                 let mut tlv2: Option<u64> = None;
1058                 let mut tlv3: Option<(PublicKey, u64, u64)> = None;
1059                 let mut tlv4: Option<u16> = None;
1060                 decode_tlv_stream!(&mut s, {(1, tlv1, option), (2, tlv2, option), (3, tlv3, option), (254, tlv4, option)});
1061                 Ok((tlv1, tlv2, tlv3, tlv4))
1062         }
1063
1064         #[test]
1065         fn bolt_tlv_bogus_stream() {
1066                 macro_rules! do_test {
1067                         ($stream: expr, $reason: ident) => {
1068                                 if let Err(DecodeError::$reason) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
1069                                 } else { panic!(); }
1070                         }
1071                 }
1072
1073                 // TLVs from the BOLT test cases which should not decode as either n1 or n2
1074                 do_test!(concat!("fd01"), ShortRead);
1075                 do_test!(concat!("fd0001", "00"), InvalidValue);
1076                 do_test!(concat!("fd0101"), ShortRead);
1077                 do_test!(concat!("0f", "fd"), ShortRead);
1078                 do_test!(concat!("0f", "fd26"), ShortRead);
1079                 do_test!(concat!("0f", "fd2602"), ShortRead);
1080                 do_test!(concat!("0f", "fd0001", "00"), InvalidValue);
1081                 do_test!(concat!("0f", "fd0201", "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"), ShortRead);
1082
1083                 do_test!(concat!("12", "00"), UnknownRequiredFeature);
1084                 do_test!(concat!("fd0102", "00"), UnknownRequiredFeature);
1085                 do_test!(concat!("fe01000002", "00"), UnknownRequiredFeature);
1086                 do_test!(concat!("ff0100000000000002", "00"), UnknownRequiredFeature);
1087         }
1088
1089         #[test]
1090         fn bolt_tlv_bogus_n1_stream() {
1091                 macro_rules! do_test {
1092                         ($stream: expr, $reason: ident) => {
1093                                 if let Err(DecodeError::$reason) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
1094                                 } else { panic!(); }
1095                         }
1096                 }
1097
1098                 // TLVs from the BOLT test cases which should not decode as n1
1099                 do_test!(concat!("01", "09", "ffffffffffffffffff"), InvalidValue);
1100                 do_test!(concat!("01", "01", "00"), InvalidValue);
1101                 do_test!(concat!("01", "02", "0001"), InvalidValue);
1102                 do_test!(concat!("01", "03", "000100"), InvalidValue);
1103                 do_test!(concat!("01", "04", "00010000"), InvalidValue);
1104                 do_test!(concat!("01", "05", "0001000000"), InvalidValue);
1105                 do_test!(concat!("01", "06", "000100000000"), InvalidValue);
1106                 do_test!(concat!("01", "07", "00010000000000"), InvalidValue);
1107                 do_test!(concat!("01", "08", "0001000000000000"), InvalidValue);
1108                 do_test!(concat!("02", "07", "01010101010101"), ShortRead);
1109                 do_test!(concat!("02", "09", "010101010101010101"), InvalidValue);
1110                 do_test!(concat!("03", "21", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb"), ShortRead);
1111                 do_test!(concat!("03", "29", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb0000000000000001"), ShortRead);
1112                 do_test!(concat!("03", "30", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb000000000000000100000000000001"), ShortRead);
1113                 do_test!(concat!("03", "31", "043da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb00000000000000010000000000000002"), InvalidValue);
1114                 do_test!(concat!("03", "32", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb0000000000000001000000000000000001"), InvalidValue);
1115                 do_test!(concat!("fd00fe", "00"), ShortRead);
1116                 do_test!(concat!("fd00fe", "01", "01"), ShortRead);
1117                 do_test!(concat!("fd00fe", "03", "010101"), InvalidValue);
1118                 do_test!(concat!("00", "00"), UnknownRequiredFeature);
1119
1120                 do_test!(concat!("02", "08", "0000000000000226", "01", "01", "2a"), InvalidValue);
1121                 do_test!(concat!("02", "08", "0000000000000231", "02", "08", "0000000000000451"), InvalidValue);
1122                 do_test!(concat!("1f", "00", "0f", "01", "2a"), InvalidValue);
1123                 do_test!(concat!("1f", "00", "1f", "01", "2a"), InvalidValue);
1124
1125                 // The last BOLT test modified to not require creating a new decoder for one trivial test.
1126                 do_test!(concat!("ffffffffffffffffff", "00", "01", "00"), InvalidValue);
1127         }
1128
1129         #[test]
1130         fn bolt_tlv_valid_n1_stream() {
1131                 macro_rules! do_test {
1132                         ($stream: expr, $tlv1: expr, $tlv2: expr, $tlv3: expr, $tlv4: expr) => {
1133                                 if let Ok((tlv1, tlv2, tlv3, tlv4)) = tlv_reader_n1(&::hex::decode($stream).unwrap()[..]) {
1134                                         assert_eq!(tlv1.map(|v| v.0), $tlv1);
1135                                         assert_eq!(tlv2, $tlv2);
1136                                         assert_eq!(tlv3, $tlv3);
1137                                         assert_eq!(tlv4, $tlv4);
1138                                 } else { panic!(); }
1139                         }
1140                 }
1141
1142                 do_test!(concat!(""), None, None, None, None);
1143                 do_test!(concat!("21", "00"), None, None, None, None);
1144                 do_test!(concat!("fd0201", "00"), None, None, None, None);
1145                 do_test!(concat!("fd00fd", "00"), None, None, None, None);
1146                 do_test!(concat!("fd00ff", "00"), None, None, None, None);
1147                 do_test!(concat!("fe02000001", "00"), None, None, None, None);
1148                 do_test!(concat!("ff0200000000000001", "00"), None, None, None, None);
1149
1150                 do_test!(concat!("01", "00"), Some(0), None, None, None);
1151                 do_test!(concat!("01", "01", "01"), Some(1), None, None, None);
1152                 do_test!(concat!("01", "02", "0100"), Some(256), None, None, None);
1153                 do_test!(concat!("01", "03", "010000"), Some(65536), None, None, None);
1154                 do_test!(concat!("01", "04", "01000000"), Some(16777216), None, None, None);
1155                 do_test!(concat!("01", "05", "0100000000"), Some(4294967296), None, None, None);
1156                 do_test!(concat!("01", "06", "010000000000"), Some(1099511627776), None, None, None);
1157                 do_test!(concat!("01", "07", "01000000000000"), Some(281474976710656), None, None, None);
1158                 do_test!(concat!("01", "08", "0100000000000000"), Some(72057594037927936), None, None, None);
1159                 do_test!(concat!("02", "08", "0000000000000226"), None, Some((0 << 30) | (0 << 5) | (550 << 0)), None, None);
1160                 do_test!(concat!("03", "31", "023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb00000000000000010000000000000002"),
1161                         None, None, Some((
1162                                 PublicKey::from_slice(&::hex::decode("023da092f6980e58d2c037173180e9a465476026ee50f96695963e8efe436f54eb").unwrap()[..]).unwrap(), 1, 2)),
1163                         None);
1164                 do_test!(concat!("fd00fe", "02", "0226"), None, None, None, Some(550));
1165         }
1166
1167         fn do_simple_test_tlv_write() -> Result<(), io::Error> {
1168                 let mut stream = VecWriter(Vec::new());
1169
1170                 stream.0.clear();
1171                 _encode_varint_length_prefixed_tlv!(&mut stream, {(1, 1u8, required), (42, None::<u64>, option)});
1172                 assert_eq!(stream.0, ::hex::decode("03010101").unwrap());
1173
1174                 stream.0.clear();
1175                 _encode_varint_length_prefixed_tlv!(&mut stream, {(1, Some(1u8), option)});
1176                 assert_eq!(stream.0, ::hex::decode("03010101").unwrap());
1177
1178                 stream.0.clear();
1179                 _encode_varint_length_prefixed_tlv!(&mut stream, {(4, 0xabcdu16, required), (42, None::<u64>, option)});
1180                 assert_eq!(stream.0, ::hex::decode("040402abcd").unwrap());
1181
1182                 stream.0.clear();
1183                 _encode_varint_length_prefixed_tlv!(&mut stream, {(42, None::<u64>, option), (0xff, 0xabcdu16, required)});
1184                 assert_eq!(stream.0, ::hex::decode("06fd00ff02abcd").unwrap());
1185
1186                 stream.0.clear();
1187                 _encode_varint_length_prefixed_tlv!(&mut stream, {(0, 1u64, required), (42, None::<u64>, option), (0xff, HighZeroBytesDroppedBigSize(0u64), required)});
1188                 assert_eq!(stream.0, ::hex::decode("0e00080000000000000001fd00ff00").unwrap());
1189
1190                 stream.0.clear();
1191                 _encode_varint_length_prefixed_tlv!(&mut stream, {(0, Some(1u64), option), (0xff, HighZeroBytesDroppedBigSize(0u64), required)});
1192                 assert_eq!(stream.0, ::hex::decode("0e00080000000000000001fd00ff00").unwrap());
1193
1194                 Ok(())
1195         }
1196
1197         #[test]
1198         fn simple_test_tlv_write() {
1199                 do_simple_test_tlv_write().unwrap();
1200         }
1201 }