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