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